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Papers - Enoki, Yuki

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Predictive Value of Vancomycin AUC<inf>24</inf>/MIC Ratio for 30-day Mortality in Patients with Severe or Complicated Methicillin-Resistant Staphylococcus aureus Infections: A Multicenter Retrospective Study

Hanai Y., Hashi H., Hanawa K., Endo A., Miyazaki T., Yamaguchi T., Harada S., Yokoo T., Uekusa S., Namiki T., Yokoyama Y., Asakawa D., Isoda R., Enoki Y., Taguchi K., Matsumoto K., Matsuo K.

Pharmaceutical Research 41 ( 7 ) 1381 - 1389 2024.07

ISSN 07248741

Background: Although vancomycin is typically employed against methicillin-resistant Staphylococcus aureus (MRSA) infections, the optimal ratio of 24-h area under the concentration–time curve to minimum inhibitory concentration (AUC24/MIC) for severe or complicated infections lacks clear guideline recommendations. This study aimed to determine the target AUC24/MIC ratio associated with treatment outcomes of infections treated with vancomycin. Methods: This retrospective multicenter cohort study included adult patients receiving ≥ 5 days of vancomycin for severe/complicated MRSA infections (e.g., osteoarticular, pulmonary, endocarditis, etc.) between January 2018 and December 2023. The primary outcome was 30-day mortality, with secondary outcomes including clinical success, microbiological eradication, and nephrotoxicity. Receiver operating characteristic (ROC) curve analysis was used to identify the AUC24/MIC cutoff for 30-day mortality. Multivariate regression analysis was used to determine association between AUC24/MIC and outcomes. Results: This study included 82 patients. ROC identified a target AUC24/MIC of ≥ 505 for 30-day mortality. The overall 30-day mortality rate (22.0%) was significantly higher for below average AUC24/MIC cutoff (34.1%) than for above AUC24/MIC cutoff group (9.8%). Multivariate analysis confirmed AUC24/MIC of < 505 as an independent predictor (adjusted odds ratio, 5.001; 95% confidence interval, 1.335–18.75). The clinical success rate differed significantly between below- and above-cutoff groups, whereas microbiological eradication tended to favor the above-cutoff group. The nephrotoxicity rates were comparable between groups. Conclusions: In treating severe/complicated MRSA infections, vancomycin AUC24/MIC ratio ≥ 505 was independently associated with favorable 30-day mortality. Given the retrospective nature of this study, further prospective studies are essential to confirm the reliability of the target AUC24/MIC ratios.

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Relationship between nephrotoxicity and area under the concentration-time curve of vancomycin in critically ill patients: a multicenter retrospective study

Ishigo T., Matsumoto K., Yoshida H., Tanaka H., Ibe Y., Fujii S., Fukudo M., Fujihara H., Yamaguchi F., Ebihara F., Maruyama T., Hamada Y., Samura M., Nagumoi F., Komatsu T., Tomizawa A., Takuma A., Chiba H., Nishi Y., Enoki Y., Taguchi K., Suzuki A.

Microbiology Spectrum 12 ( 7 ) e0373923 2024.07

ISSN 2165-0497

We aimed to assess the frequency of acute kidney injury (AKI) in differentareas under the concentration-time curve (AUC) values of vancomycin (VAN) using a two-point blood collection method, allowing for accurate AUC assessment in critically ill patients. This multicenter retrospective observational study was conducted in eight hospitals. We retrospectively analyzed the data of patients who had received VAN in an intensive care unit (ICU) between January 2020 and December 2022. The primary outcome was the incidence of AKI. Patients were classifiedinto three groups according to the AUC24-48h at the initial therapeutic drug monitoring (TDM) as follows: <500, 500-600, and ≥600 μg h/mL. The AUC24-48h values were calculated using the Bayesian estimation software Practical AUC-guided TDM. Among 146 patients [median age (interquartile range), 67 (56-78) years; 39% women], the AUC24-48h <500 μg h/mL had an AKI rate of 6.5% (7/107), the AUC24-48h 500-600 μg h/mL had an AKI rate of 28.0% (7/25), and the AUC24-48h ≥600 μg h/mL had an AKI rate of 42.9% (6/14). In multivariate Cox proportional hazard analysis, the AUC24-48h 500-600 μg h/mL [hazard ratio 5.4, 95% confidenceinterval (CI) 1.64-17.63] and the AUC24-48h ≥600 μg h/mL (hazard ratio 7.0, 95% CI 2.31-21.18) significantlycorrelated with a higher incidence of AKI compared with the AUC24-48h <500 μg h/mL. In conclusion, we identifiedan association between AUC on day 2 and the risk of AKI in ICU patients, suggesting that not only AUCs above 600 μg h/mL but also those between 500 and 600 μg h/mL pose a risk for AKI.

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Anti-edematous effects of epinastine, cetirizine and its enantiomers in λ-carrageenan-induced edema in rat hind paw

Taguchi K., Chuang V.T.G., Ozawa M., Sakamoto Y., Hara R., Iketani O., Enoki Y., Kizu J., Hori S., Matsumoto K.

Pharmazie 79 ( 6 ) 98 - 100 2024.06

ISSN 00317144

Urticaria is induced by the histamine released from mast cells which develops wheals (edema) as a visual feature. In clinical practice, second-generation histamine H1-receptor blockers are routinely used as the first-line symptomatic treatment for urticaria. Nevertheless, not much research has directly examined the second-generation histamine H1-receptor blockers’ ability to reduce edema. In this study, we directly evaluated the anti-edematous activities of three second-generation histamine H1-receptor blockers available in the market (epinastine hydrochloride, cetirizine hydrochloride, and levocetirizine hydrochloride) using a λ-carrageenan-induced footpad edema model. One hour before the induction of edema with 1% λ-carrageenan injection, all second-generation histamine H1-receptor blockers (5, 10, 50 and 100 mg/kg) were subcutaneously administered to rats. At 0.5 and 3 hours after λ-carrageenan administration, the edema volume was evaluated using a Plethysmometer. Epinastine hydrochloride significantly suppressed the edema growth in a dose-dependent manner. Cetirizine hydrochloride showed a slight anti-edematous effect, while levocetirizine significantly inhibited the development of edema in a dose-dependent manner. On the other hand, dextrocetirizine did not prevent edema from growing. In summary, second-generation histamine H1-receptor blockers, at least those examined in this study, may be able to reduce the clinical symptoms of urticaria associated with edema. Levocetirizine hydrochloride is also anticipated to have stronger anti-edematous effects than cetirizine hydrochloride because levocetirizine is responsible for cetirizine’s anti-edematous activity.

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Dual delivery of carbon monoxide and doxorubicin using haemoglobin-albumin cluster: proof of concept for well-tolerated cancer therapy

Ito C., Taguchi K., Yamada T., Hanaya K., Enoki Y., Sugai T., Komatsu T., Matsumoto K.

Journal of Materials Chemistry B 12 ( 23 ) 5600 - 5608 2024.05

ISSN 2050750X

A serious concern of doxorubicin (DOX) therapy is that it causes severe adverse effects, particularly cardiotoxicity. Carbon monoxide (CO) possesses powerful cytoprotective effects against drug-induced organ injury and is expected to ameliorate DOX-induced cardiotoxicity. In this study, a dual carrier of DOX and CO (CO-HemoAct-DOX) was fabricated based on a haemoglobin-albumin cluster (HemoAct), which is a protein cluster with a haemoglobin core structure wrapped by serum albumin. CO-HemoAct-DOX was synthesised by binding CO to a haemoglobin core and covalently conjugating (6-maleimidocaproyl)hydrazone derivative of DOX to an albumin shell. The average DOX/cluster ratio was about 2.6. In the in vitro cytotoxicity assay against cancer cells, the anti-tumour activity of CO-HemoAct-DOX was 10-fold lower than that of DOX in a 2D-cultured model, whereas CO-HemoAct-DOX suppressed the growth of tumour spheroids to the same extent as DOX in the 3D-cultured model. In colon-26 tumour-bearing mice, CO-HemoAct-DOX achieved DOX delivery to the tumour site and alleviated tumour growth more effectively than DOX. Furthermore, CO-HemoAct attenuated DOX-induced cardiomyocyte atrophy in H9c2 cells and elevated the levels of cardiac biomarkers in mice exposed to DOX. These results suggest that the dual delivery of CO and DOX using HemoAct is a promising strategy as an anti-tumour agent to realise well-tolerated cancer therapy with minimal cardiotoxicity.

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Direct comparison of anti-inflammatory effects of 14-, 15-, and 16-membered macrolide antibiotics in experimental inflammation model induced by carrageenan in rats

Taguchi K., Chuang V.T.G., Ogino H., Hara R., Iketani O., Enoki Y., Kizu J., Hori S., Matsumoto K.

Pharmazie 79 ( 3-5 ) 64 - 66 2024.05

ISSN 00317144

Some macrolide antibiotics, which share a basic lactone ring structure, also exhibit anti-inflammatory actions in addition to their antibacterial activities. However, no study has directly compared anti-inflammatory effects on acute inflammation among macrolide antibiotics with the distinct size of the lactone ring. In this study, we evaluated and compared the anti-inflammatory activities of four 14-membered macrolides (erythromycin, clarithromycin, roxithromycin, oleandomycin), one 15-membered macrolide (azithromycin), and three 16-membered macrolides (midecamycin, josamycin, leucomycin) using a rat carrageenan-induced footpad edema model. All macrolide antibiotics were intraperitoneally administered to rats one hour before the induction of inflammatory edema with 1% λ-carrageenan. The anti-inflammatory effects on acute inflammation were evaluated by changing the edema volume. All 14-membered and 15-membered macrolide antibiotics significantly suppressed the development of edema. Conversely, none of the 16-membered macrolide antibiotics inhibited the growth of edema. In conclusion, compared to 16-membered macrolide antibiotics, 14-membered and 15-membered macrolide antibiotics have stronger anti-inflammatory effects. Further research should be done to determine why different lactone ring sizes should have distinct anti-inflammatory effects.

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Flowchart for predicting achieving the target area under the concentration-time curve of vancomycin in critically ill Japanese patients: A multicenter retrospective study

Ishigo T., Fujii S., Ibe Y., Aigami T., Nakano K., Fukudo M., Yoshida H., Tanaka H., Ebihara F., Maruyama T., Hamada Y., Suzuki A., Fujihara H., Yamaguchi F., Samura M., Nagumo F., Komatsu T., Tomizawa A., Takuma A., Chiba H., Nishi Y., Enoki Y., Taguchi K., Matsumoto K.

Journal of Infection and Chemotherapy 30 ( 4 ) 329 - 336 2024.04

ISSN 1341321X

Introduction: In therapeutic drug monitoring (TDM) of vancomycin (VCM), the area under the concentration-time curve (AUC) is related to the clinical efficacy and toxicity. Therefore, herein, we examined the factors associated with achieving the target AUC at follow-up and developed a decision flowchart for achieving the target AUC in critically ill patients. Methods: This multicenter retrospective observational study was conducted at eight hospitals. We retrospectively analyzed data from patients who had received VCM in the intensive care unit from January 2020 to December 2022. Decision-tree (DT) analysis was performed using factors with p < 0.1 in univariate analysis as the independent variables. Case data were split up to two times, and four subgroups were included. The primary endpoint was achieving the target AUC at the follow-up TDM (AUCfollow-up) and target AUCfollow-up achievement was defined as an AUC of 400–600 μg‧h/mL. The initial AUC values were calculated with the 2-point concentrations (peak and trough) using the Bayesian estimation software Practical AUC-guided TDM (PAT). Results: Among 70 patients (median age [interquartile range], 66 [56, 79] years; 50 % women), the AUCfollow-up was achieved in 70 % (49/70). Three factors were selected for the decision flow chart: predicted AUCfollow-up of 400–600 μg‧h/mL, dosing at 12-h intervals, and CCr of 130 mL/min/1.73 m2 or higher; the accuracy was adequate (92 %, R2 0.52). Conclusion: We successfully identified the factors associated with achieving the target AUC of VCM at follow-up TDM and developed a simple-to-use DT model. However, the validity of the findings needs to be evaluated.

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T-cell immunosuppression in sepsis is augmented by sciatic denervation-induced skeletal muscle atrophy

Osa S., Enoki Y., Takahashi D., Chuang V.T.G., Taguchi K., Matsumoto K.

FEBS Letters 2024

ISSN 00145793

Skeletal muscle atrophy is a known risk factor for immunosuppressive conditions and for a poor prognosis in sepsis. However, its immunopathology has not been experimentally elucidated. This study investigated the effects of skeletal muscle atrophy on the immunopathology of sepsis. Male C57BL/6J mice were subjected to sciatic denervation (DN) and caecal ligation and puncture (CLP) to induce muscle atrophy or sepsis. The macrophages, myeloid-derived suppressor cells (MDSC), and T-cells in peritoneal and spleen were analysed using flow cytometry. DN-induced muscle atrophy did not affect macrophage and MDSC populations. In contrast, the percentage of cytotoxic T-lymphocyte-associated antigen (CTLA)-4+ CD4+ T-cells, programmed death (PD)-1+ CD8+ T-cells, regulatory T-cells, and the CTLA-4+ regulatory T-cells was statistically significantly higher in DN-CLP mice than in sham-CLP mice. Skeletal muscle atrophy before sepsis triggers excessive T cell immunosuppression, which may contribute to the exacerbation of sepsis under skeletal muscle atrophy.

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SARS-CoV-2 mRNA vaccine-related myocarditis and pericarditis: An analysis of the Japanese Adverse Drug Event Report database

Takada K., Taguchi K., Samura M., Igarashi Y., Okamoto Y., Enoki Y., Tanikawa K., Matsumoto K.

Journal of Infection and Chemotherapy 2024

ISSN 1341321X

Background: The association between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccines and myocarditis/pericarditis in the Japanese population has not been systematically investigated. This study was aimed at clarifying the association between SARS-CoV-2 mRNA vaccines (BNT162b2 and mRNA-1273) and myocarditis/pericarditis as well as influencing factors by using the Japanese Adverse Drug Event Report database. Methods: Reporting odds ratios (RORs) and 95 % confidence intervals (95 % CIs) for the association between the vaccines and myocarditis/pericarditis were calculated using data from the database (April 2004–December 2023). Age, sex, onset time, and outcomes in symptomatic patients were evaluated. Results: The total number of reports was 880,999 (myocarditis: 1846; pericarditis: 761). The adverse events associated with the vaccines included myocarditis (919 cases) and pericarditis (321 cases), with the ROR [95 % CIs] being significant for both (myocarditis: 30.51 [27.82–33.45], pericarditis: 21.99 [19.03–25.40]). Furthermore, the ROR [95 % CIs] of BNT162b2 and mRNA-1273 were 15.64 [14.15–17.28] and 54.23 [48.13–61.10], respectively, for myocarditis, and 15.78 [13.52–18.42] and 27.03 [21.58–33.87], respectively, for pericarditis. Furthermore, most cases were ≤30 years or male. The period from vaccination to onset was ≤8 days, corresponding to early failure type based on analysis using the Weibull distribution. Outcomes were recovery or remission for most cases; however, they were severe or caused death in some cases. Conclusion: In the Japanese population, SARS-CoV-2 mRNA vaccination was significantly associated with the onset of myocarditis/pericarditis. The influencing factors included age of ≤30 years and male. Furthermore, although most adverse events occurred early after vaccination, overall outcomes were good.

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Antimicrobial Stewardship of Oral Third-Generation Cephalosporins in Community Pharmacy: A Single-Center Quasi-Experimental Study

Nakamura Koyo, Matsumoto Kazuaki, Enoki Yuki, Taguchi Kazuaki, Yamashita Shuji, Kai Junko, Hayashi Hideki

Biological and Pharmaceutical Bulletin (The Pharmaceutical Society of Japan) 47 ( 8 ) 1447 - 1451 2024

ISSN 0918-6158

Proper use of antimicrobials in hospital and outpatient settings is critical for minimizing the occurrence of antimicrobial resistance. Some hospitals have intervened in the inappropriate use of third-generation oral cephalosporins. However, there have been no such studies in community pharmacy settings. This study aimed to investigate how the use of oral third-generation cephalosporins in community pharmacies affects the amount of antimicrobials used. Patients who visited Nakanomaru Pharmacy after being prescribed antimicrobials at target medical institutions between February 2021 and January 2023 were identified. The number of oral antimicrobials used, duration of use, number of prescriptions, patient age and sex, and infectious diseases in the target patients before and after the intervention for the proper use of oral third-generation cephalosporins were retrospectively investigated based on the patients’ medication history and prescription receipts. Through efforts to ensure the proper use of oral third-generation cephalosporins, the amount of oral third-generation cephalosporins used has decreased, and the use of penicillins and oral first-generation cephalosporins has increased. There was no increase in the antimicrobial change or relapse rates associated with treatment failure before and after the initiation of appropriate antimicrobial use. By working toward the proper use of oral third-generation cephalosporins in community pharmacies, we were able to reduce the doses of oral third-generation cephalosporins without compromising their therapeutic efficacy. We believe that recommending the selection of narrow-spectrum antimicrobials based on these guidelines will contribute to their proper use.

Elucidating the binding properties of methemoglobin in red blood cell to cyanide, hydrosulfide, and azide ions using artificial red blood cell

Suzuki Y., Arakida Y., Sakai H., Enoki Y., Matsumoto K., Taguchi K.

Toxicology and Applied Pharmacology 481 116752 2023.12

ISSN 0041008X

Methemoglobin (metHb), the oxidized form of hemoglobin, lacks the ability of reversible oxygen binding; however, it has a high binding affinity to toxic substances such as cyanide, hydrosulfide, and azide. This innate property of metHb offers the clinical option to treat patients poisoned with these toxins, by oxidizing the endogenous hemoglobin in the red blood cells (RBCs). The binding properties of naked metHb (isolated from RBC) with these toxins has been studied; however, the binding behaviors of metHb under the intracellular conditions of RBC are unclear because of the difficulty in detecting metHb status changes in RBC. This study aimed to elucidate the binding properties of metHb in RBC under physiological and poisoned conditions using artificial RBC, which was hemoglobin encapsulated in a liposome. The mimic-circumstances of metHb in RBC (metHb-V) was prepared by oxidizing the hemoglobin in artificial RBC. Spectroscopic analysis indicated that the metHb in metHb-V exhibited a binding behavior different from that of naked metHb, depending on the toxic substance: When the pH decreased, (i) the cyanide binding affinity of metHb-V remained unchanged, but that of naked metHb decreased (ii) the hydrosulfide binding affinity was increased in metHb-V but was decreased in naked metHb. (iii) Azide binding was increased in metHb-V, which was similar to that in naked metHb, irrespective of the pH change. Thus, the binding behavior of intracellular metHb in the RBC with cyanide, hydrosulfide, and azide under physiological and pathological conditions were partly elucidated using the oxidized artificial RBC.

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Oral teicoplanin administration suppresses recurrence of Clostridioides difficile infection: Proof of concept

Tanaka Y., Tashiro S., Ikegami S., Enoki Y., Taguchi K., Matsumoto K.

Anaerobe 84 102789 2023.12

ISSN 10759964

Objectives: Teicoplanin is a potential antimicrobial candidate for Clostridioides difficile infection (CDI) treatment. However, the therapeutic potential of teicoplanin against severe CDI has not been clinically proven. In the present study, we investigated the efficacy of oral teicoplanin administration against severe CDI and the recurrence of severe CDI after teicoplanin treatment in a mouse model. Methods: A lethal CDI mouse model was established by colonizing the mice with C. difficile ATCC® 43255; they were orally administered teicoplanin (128 mg/kg/d) or vancomycin (160 mg/kg/d) for 10 d, 24 h after C. difficile spore challenge, and physiological and biological responses were monitored for 20 d after the initial antibiotic treatment. We also performed the in vitro time-kill assay and determined minimum inhibitory concentration (MIC), post-antibiotic effect, and toxin production with antibiotic exposure. Results: The therapeutic response (survival rates, body weight change, clinical sickness score grading, C. difficile load, and toxin titer in feces) of oral teicoplanin administration was comparable to that of oral vancomycin administration in the lethal CDI mouse model. Moreover, teicoplanin treatment suppressed the re-onset of diarrhea and re-increase in toxin titer 10 d after treatment compared with that by vancomycin treatment. In in vitro experiments, teicoplanin exhibited time-dependent antibacterial activity and possessed lower MIC and longer post-antibiotic effect than vancomycin against C. difficile. C. difficile toxin production was numerically lower with teicoplanin exposure than with vancomycin exposure. Conclusions: The results obtained from the present basic experiments could suggest that teicoplanin is a potential antibiotic for the treatment of severe CDI with recurrence-prevention activity.

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The anti-inflammatory effect of tedizolid on carrageenan-induced footpad edema rat model

Isobe N., Chuang V.T.G., Liu X., Enoki Y., Taguchi K., Matsumoto K.

Journal of Infection and Chemotherapy 29 ( 11 ) 1088 - 1090 2023.11

ISSN 1341321X

Tedizolid (TZD) is an oxazolidinone anti-methicillin-resistant Staphylococcus aureus (MRSA) drug. Linezolid (LZD), another oxazolidinone, has been shown to have an anti-inflammatory effect. TZD has been shown to exhibit an anti-inflammatory effect in a murine model of hematogenous pulmonary infection. In this study, we further investigated the anti-inflammatory effect of TZDs using a carrageenan-induced rat footpad edema model. TZD was administered at 0, 10, 20, and 40 mg/kg to the carrageenan-induced rat footpad edema model, and the edema rate was measured over time up to 9 h later. The area under the time curve of the edema rate profile (AUCedema0→9) decreased in a TZD dose-dependent manner. In addition, the correlation between AUCedema0→9 and the area under the time curve of free TZD plasma concentration (fAUCblood) obtained from the pharmacokinetic study of TZD in the carrageenan-induced rat footpad edema model was examined. fAUCblood and AUCedema0→9 showed a good negative correlation. These results indicate that TZD suppresses carrageenan-induced footpad edema and that TZD exerts its anti-inflammatory effects in a plasma concentration-dependent manner.

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Pharmaceutical stability of methemoglobin-albumin cluster as an antidote for hydrogen sulfide poisoning after one-year storage in freeze-dried form

Suzuki Y., Taguchi K., Okamoto W., Enoki Y., Komatsu T., Matsumoto K.

International Journal of Pharmaceutics 645 123433 2023.10

ISSN 03785173

Long-term stability during storage is an important requirement for pharmaceutical preparations. The methemoglobin (metHb)-albumin cluster, in which bovine metHb is covalently enveloped with an average of three human albumin molecules, is a promising antidote for hydrogen sulfide (H2S) poisoning. In this study, we investigated the pharmaceutical stability of metHb-albumin cluster after storage for one year in solution and as freeze-dried powder. The lyophilized powder of metHb-albumin cluster stored for one year was readily reconstituted in sterile water for injection, yielding a homogeneous brown solution. Physicochemical measurements revealed that the overall structure of the metHb-albumin cluster was still maintained after preservation. Results of the pharmacological study showed that 100 % of the H2S-poisoned mice survived after treatment with the reconstituted solution of metHb-albumin cluster powder. Furthermore, the solution did not cause any toxic reactions. The antidotal efficacy of metHb-albumin cluster for H2S poisoning was preserved in freeze-dried powder form for at least one year.

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A combination of 5/6-nephrectomy and unilateral ureteral obstruction model accelerates progression of remote organ fibrosis in chronic kidney disease

Homma K., Enoki Y., Uchida S., Taguchi K., Matsumoto K.

FASEB BioAdvances 5 ( 10 ) 377 - 394 2023.10

Chronic kidney disease (CKD) involves progressive renal fibrosis, which gradually reduces kidney function and often causes various complications in extrarenal tissues. Therefore, we investigated fibrogenesis in extrarenal tissues (heart, liver, and lungs) in different experimental CKD models, such as the 5/6-nephrectomy (5/6 Nx), unilateral ureteral obstruction (UUO), and a combination (2/3 Nx + UUO). We evaluated the degree of fibrogenesis in kidneys and extrarenal tissues by histological analysis and quantification of fibrosis-related gene and protein expression. To elucidate the fibrosis mechanisms observed in 2/3 Nx + UUO mice, we evaluated the effect of indoxyl sulfate (IS), a typical uremic toxin accumulated in CKD, and transforming growth factor-β (TGF-β), a fibrosis-related factor, on fibrosis using human hepatoma (HepG2) and RAW264.7 cells. A significant decline in renal function was observed in the 5/6 Nx and 2/3 Nx + UUO models, whereas a significant increase in renal fibrosis was observed only in the obstructed kidneys. Notable amount of fibrosis was induced in the liver and heart in the 2/3 Nx + UUO model, with the induction of macrophage infiltration and increased tissue IS and TGF-β levels. In agreement with the results of in vivo experiments, co-stimulation with IS, TGF-β, and macrophage-conditioned medium increased the expression of fibrogenic genes in HepG2 cells. We demonstrated that the 2/3 Nx + UUO model induced both loss of renal function and renal fibrosis in the earlier stages, providing a novel CKD model that induces remote organ fibrosis in a shorter time.

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In vivo Pharmacokinetic/Pharmacodynamic Analysis of the Efficacy of the Cefepime/Nacubactam Combination Against β-Lactamase-Producing Enterobacterales based on the Instantaneous MIC Concept

Igarashi Y., Takemura W., Liu X., Kojima N., Morita T., Chuang V.T.G., Enoki Y., Taguchi K., Matsumoto K.

Pharmaceutical Research 40 ( 10 ) 2423 - 2431 2023.10

ISSN 07248741

Purpose: Nacubactam (NAC) is a novel diazabicyclooctane β-lactamase inhibitor used in combination with cefepime (CFPM). In this study, we aimed to determine the target pharmacokinetics (PK) and pharmacodynamics (PD) values of CFPM/NAC in mice infected with β-lactamase-producing Enterobacterales, such as the carbapenemase-producing Enterobacterales. Methods: Three strains of β-lactamase-producing Enterobacterales, Klebsiella pneumoniae MSC 21444, Escherichia coli MSC 20662, and K. pneumoniae ATCC BAA-1898, were used for checkerboard assays and fractionation studies and dose-range studies. A PK study was performed in neutropenic mice. Additionally, PK/PD analysis was performed based on the instantaneous minimum inhibitory concentration (MICi) concept. Results: Checkerboard measurements revealed that higher NAC concentrations decreased the CFPM MIC in a concentration-dependent manner. In all tested strains, fT > MICi calculated from the PK experiments showed a high correlation with the mean change in the bacterial count of thigh-infected mice in the in vivo PD study, suggesting that fT > MICi is an optimal PK/PD parameter for monitoring the CFPM/NAC combination. The target fT > MICi values for CFPM/NAC to achieve a bacteriostatic effect, 1-log10-kill, and 2-log10-kill values were 30, 49, and 94%, respectively. Conclusions: Our results indicate that fT > MICi is a PK/PD parameter is suitable for monitoring the CFPM/NAC combination. The minimum target value for achieving a static effect against β-lactamase-producing Enterobacterales is 30%.

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Anti-inflammatory actions of expectorants in a rat carrageenan-induced footpad edema model

Ito M., Liu X., Taguchi K., Enoki Y., Kuroda Y., Kizu J., Matsumoto K.

Pharmazie 78 ( 6-7 ) 86 - 88 2023.07

ISSN 00317144

S-Carboxymethyl-L-cysteine (SCMS) exhibits sputum-regulating and anti-inflammatory actions. Previous studies reported the anti-inflammatory effects of SCMS on chronic inflammatory diseases, but no study has examined these effects on acute inflammatory diseases. In this study, we investigated the anti-inflammatory effects of SCMS in a rat carrageenan-induced footpad edema model, which is routinely used as an acute inflammation model. Expectorants were administered to rats with footpad edema induced by subcutaneously administering 1% λ-carrageenan to the footpad of the left posterior limb, and the dose dependency of the anti-inflammatory effects was evaluated. As a result, even when the dose of SCMS was increased to 400 mg/kg, there were no inhibitory effects on edema. Furthermore, we examined the inhibitory effects of other expectorants (ambroxol hydrochloride, N-acetyl-L-cysteine, L-cysteine ethylester hydrochloride, and L-cysteine methylester hydrochloride), which were reported to exhibit anti-inflammatory effects on chronic inflammation, on edema. However, none of these expectorants inhibited edema.

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In vivo Pharmacokinetics/Pharmacodynamics Profiles for Appropriate Doses of Cefditoren pivoxil against S. pneumoniae in Murine Lung-Infection Model

Igarashi Y., Kojima N., Takemura W., Liu X., Morita T., Mizukami Y., Enoki Y., Taguchi K., Yokoyama Y., Nakamura T., Matsumoto K.

Pharmaceutical Research 40 ( 7 ) 1789 - 1797 2023.07

ISSN 07248741

Purpose: Cefditoren, the active form of cefditoren pivoxil, is an oral cephalosporin antimicrobial drug. Although cefditoren exhibits high antimicrobial activity against Streptococcus pneumoniae, its pharmacokinetics/pharmacodynamics (PK/PD) characteristics remain unknown. This study aimed to determine its PK/PD parameter with target values for cefditoren against S. pneumoniae in S. pneumoniae lung-infected mice and to simulate MIC range of S. pneumoniae that can be expected to be treated at approved cefditoren doses in human using population pharmacokinetic (PPK) data from patients. Methods: Susceptibility testing and time-kill assays against S. pneumoniae ATCC® 49619 were performed for in vitro PD evaluation. Based on the results of a PK study in healthy mice and PD studies in S. pneumoniae lung-infected mice, optimal PK/PD parameters were determined using the correlation curve between the PK/PD parameters and lung bacterial count changes. The target value was calculated to achieve a 2 log10 reduction in the lung bacterial counts. Results: In vitro PD evaluation showed that cefditoren had a potent antimicrobial effect against S. pneumoniae in a time-dependent manner at concentrations above the MIC. In PK/PD analyses, both fAUC24/MIC and fCmax/MIC were well correlated with bactericidal efficacy, achieving 2 log10-kill with fAUC24/MIC ≥ 63 and fCmax/MIC ≥ 16. Conclusions: Cefditoren pivoxil has good therapeutic efficacy against acute pneumonia caused by S. pneumoniae with a MIC ≤ 0.031–0.063 mg/L at approved doses in adults and children.

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Antimicrobial Efficacy Evaluations of Metronidazole against Clostridioides difficile Infection using Fecal Pharmacokinetic and Pharmacodynamic Analyses

Tashiro S., Taguchi K., Enoki Y., Matsumoto K.

Pharmaceutical Research 40 ( 7 ) 1799 - 1806 2023.07

ISSN 07248741

Objectives: The pharmacokinetics/pharmacodynamics (PK/PD) characteristics of metronidazole (MNZ) in Clostridioides difficile infection (CDI) remain unclear. We aimed to determine the PK/PD characteristics of MNZ using a fecal PK/PD analysis model. Methods: Susceptibility testing, time-kill studies, and post-antibiotic effect (PAE) measurements were performed to evaluate in vitro PD profiles. MNZ was subcutaneously administered to mice infected with C. difficile ATCC® 43255 to evaluate in vivo PK and PD profiles, followed by determining fecal PK/PD indices with target value. Results: MNZ exerted concentration-dependent bactericidal activities with minimum inhibitory concentration (MIC) and PAE being 0.79 µg/mL and 4.8 h, respectively, against C. difficile ATCC® 43255. The reduction in vegetative cells in feces and treatment outcomes were most closely correlated with the ratio of the area under the fecal drug concentration–time curve from 0 to 24 h to the MIC (fecal AUC24/MIC). The target value of fecal AUC24/MIC to achieve a 1 log10 reduction in vegetative cells was 188. Upon meeting the target value, high survival rates (94.5%) and low clinical sickness score grading (5.2) were achieved in the CDI mouse models. Conclusions: The PK/PD index and its target value of MNZ for CDI treatment was fecal AUC24/MIC ≥ 188. These findings may contribute to the effective clinical use of MNZ.

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Pharmaceutical Integrity of Lyophilized Methemoglobin-Albumin Clusters after Reconstitution

Suzuki Y., Taguchi K., Okamoto W., Enoki Y., Komatsu T., Matsumoto K.

ACS Omega 8 ( 25 ) 22589 - 22595 2023.06

ISSN 2470-1343

Covalent attachment of a ferric hemoglobin (metHb) core to three human serum albumin molecules to form metHb-albumin clusters has previously been used to develop an antidote for hydrogen sulfide poisoning. Lyophilization is one of the most effective approaches to preserve protein pharmaceuticals with minimum contamination and decomposition. However, there is concern that lyophilized proteins may undergo pharmaceutical alteration on reconstitution. This study investigated the pharmaceutical integrity of metHb-albumin clusters on lyophilization and reconstitution with three clinically available reconstitution fluids, (i) sterile water for injection, (ii) 0.9% sodium chloride injection, and (iii) 5% dextrose injection. The metHb-albumin clusters retained their physicochemical properties and structural integrity on lyophilization and reconstitution with sterile water for injection or 0.9% sodium chloride injection, along with comparable hydrogen sulfide scavenging ability compared to non-lyophilized metHb-albumin clusters. The reconstituted protein completely rescued lethal hydrogen sulfide poisoning in mice. On the other hand, lyophilized metHb-albumin clusters reconstituted with 5% dextrose injection showed physicochemical changes and a higher mortality rate in mice subjected to lethal hydrogen sulfide poisoning. In conclusion, lyophilization represents a potent preservation method for metHb-albumin clusters if either sterile water for injection or 0.9% sodium chloride injection is used for reconstitution.

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Optimal therapeutic recommendation for Clostridioides difficile infection in pediatric and adolescent populations: a systematic review and meta-analysis

Tashiro S., Mihara T., Okawa R., Tanaka Y., Samura M., Enoki Y., Taguchi K., Matsumoto K., Yamagishi Y.

European Journal of Pediatrics 182 ( 6 ) 2673 - 2681 2023.06

ISSN 03406199

We conducted a systematic review and meta-analysis to examine the efficacy profiles of metronidazole (MNZ) and vancomycin (VCM) in pediatric and adolescent patients with Clostridioides difficile infection (CDI). A systematic review and meta-analysis was conducted using four electronic databases (PubMed, Cochrane Library, Web of Science, and Clinicaltrials.gov) through July 6, 2022. We analyzed the clinical cure and recurrence rates to determine the efficacy of MNZ and VCM. The clinical cure rates in all included studies were not significantly different between MNZ and VCM (OR = 0.63; 95% CI = 0.36–1.10; I2 = 0%; P = 0.10). Subgroup analyses were performed separately for each region to account for regional differences in the CDI. MNZ treatment achieved significantly lower clinical cure rates than did VCM in the United States of America (USA) and Europe (OR = 0.42, 95% CI = 0.19–0.93, I2 = 0%, P = 0.03). Recurrence rates were not significantly different between MNZ and VCM (OR = 1.48, 95% CI = 0.62–3.53, I2 = 28%, P = 0.38). Conclusion: MNZ exhibited significantly lower clinical cure rates than did VCM in the US and Europe; therefore, it is not recommended for the management of CDI in pediatric and adolescent populations.What is Known:• The unavailability of robust data on recommendations of therapeutic agents for the management of Clostridioides difficile infections in children precludes effective antibiotic choice.What is New:• Metronidazole exhibited significantly lower clinical cure rates than did vancomycin in the United States of America and Europe and recurrence rate was not significantly different between metronidazole and vancomycin; therefore, it is not recommended for the management of Clostridioides difficile infection in children.

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Methemoglobin-albumin clusters for cyanide detoxification

Suzuki Y., Taguchi K., Okamoto W., Enoki Y., Komatsu T., Matsumoto K.

Toxicology and Applied Pharmacology 466 116472 2023.05

ISSN 0041008X

Sodium nitrite (NaNO2) is a universal antidote for patients with cyanide poisoning. However, its use has serious drawbacks in terms of efficacy and safety. Herein, we present a promising antidote: methemoglobin (metHb)-albumin clusters. The metHb-albumin cluster is made by a metHb core wrapped by covalently bound human serum albumin. Spectral analyses proved that the metHb-albumin clusters possessed cyanide-binding properties similar to those of naked metHb. In vitro cell experiments showed that metHb-albumin clusters prevented the cyanide-induced inhibition of cytochrome c oxidase activity, resulting in a strong cytoprotective effect. In mice subjected to cyanide poisoning, metHb-albumin clusters reduced mortality and alleviated metabolic acidosis, while maintaining the activity of cytochrome c oxidase in organs; their efficacy was better than that of NaNO2. Furthermore, the oxygen carrying capacity was maintained in poisoned mice treated with metHb-albumin clusters and was low in those treated with NaNO2. These results indicate that metHb-albumin clusters could be a more effective and safer antidote against cyanide poisoning than NaNO2.

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Development of an optimized and practical pharmacokinetics/pharmacodynamics analysis method for aztreonam/nacubactam against carbapenemase-producing K. pneumoniae

Igarashi Y., Takemura W., Liu X., Kojima N., Morita T., Chuang V.T.G., Enoki Y., Taguchi K., Matsumoto K.

Journal of Antimicrobial Chemotherapy 78 ( 4 ) 991 - 999 2023.04

ISSN 03057453

Background: Nacubactam, a new β-lactamase inhibitor with antibacterial activity, is being developed as a single drug to be co-administered with cefepime or aztreonam. However, determining pharmacokinetics/pharmacodynamics (PK/PD) parameters in β-lactam/β-lactamase inhibitor combinations remains challenging. We aimed to establish a practical PK/PD analysis method for aztreonam/nacubactam that incorporates instantaneous MIC (MICi). Methods: Based on chequerboard MIC measurements, MICi of aztreonam against carbapenemase-producing Klebsiella pneumoniae in the presence of nacubactam was simulated. Results: The mean change in the bacterial count of thigh-infected mice in an in vivo PD study was plotted based on %fT>MICi and analysed using the inhibitory effect sigmoid Imax model. fT>MICi calculated from the PK experiments showed a high correlation with the in vivo bactericidal effect, suggesting that fT>MICi is the optimal PK/PD parameter for aztreonam/nacubactam. The target values of fT>MICi achieving growth inhibition, 1 log10 kill and 2 log10 kill, were 22, 38% and 75%, respectively. Conclusions: The PK/PD analysis method proposed in this study is promising for determining practical PK/PD parameters in combination therapy. In addition, this is the first report of aztreonam/nacubactam showing a potent in vivo therapeutic effect against NDM-producing K. pneumoniae.

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Comparison of the efficacy and safety of standard- and high-dose daptomycin: A systematic review and meta-analysis

Samura M., Takada K., Hirose N., Kurata T., Nagumo F., Uchida M., Inoue J., Tanikawa K., Enoki Y., Taguchi K., Matsumoto K., Ueda T., Fujimura S., Mikamo H., Takesue Y., Mitsutake K.

British Journal of Clinical Pharmacology 89 ( 4 ) 1291 - 1303 2023.04

ISSN 03065251

Aims: Standard doses of daptomycin at 4 and 6 mg/kg were used for the treatment of skin and soft tissue for infections and bacteraemia, respectively. However, increased doses of daptomycin are recommended for complicated infections by Gram-positive organisms. Methods: A systematic review was conducted using 4 databases. We compared treatment success between standard-dose (SD, 4–6 mg/kg) and high-dose (HD, >6 mg/kg) daptomycin in patients with all-cause bacteraemia, complicated bacteraemia, infective endocarditis, osteomyelitis and foreign body/prosthetic infection as the primary outcome. We also compared the success between SD and HD2 (≥8 mg/kg) daptomycin treatments in patients with these diseases as the secondary outcome. The incidence of creatine phosphokinase (CPK) elevation was evaluated as safety. Results: In patients with complicated bacteraemia and infective endocarditis, the treatment success was significantly lower in the SD group than in the HD group (odds ratio [OR] 0.48, 95% confidence interval [CI] 0.30–0.76 and OR 0.50, 95% CI 0.30–0.82) and HD2 group (OR 0.38, 95% CI 0.21–0.69 and OR 0.30, 95% CI 0.15–0.60), respectively. A significant difference was demonstrated only in the HD2 group in patients with bacteraemia, including simple infection. SD did not decrease the success rate for the treatment of osteomyelitis and foreign body/prosthetic infection. The incidence of elevated CPK was significantly lower in SD group than in HD group. Conclusion: SD daptomycin was associated with significantly lower treatment success than HD in patients with complicated bacteraemia/infective endocarditis. The CPK elevation should be considered in patients treated with high daptomycin doses.

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Analysis of Risk Factors for Developing Tuberculosis in Patients Who Received Prophylactic Latent Tuberculosis Infection Treatment with Experience of Biologic Medications

Itagaki Marina, Iketani Osamu, Enoki Yuki, Chuang Victor Tuan Giam, Taguchi Kazuaki, Uno Shunsuke, Uchida Sho, Namkoong Ho, Uwamino Yoshifumi, Takano Yaoko, Hasegawa Naoki, Matsumoto Kazuaki

Biological and Pharmaceutical Bulletin (The Pharmaceutical Society of Japan) 46 ( 12 ) 1832 - 1837 2023

ISSN 09186158

Biologic medications have dramatically improved the treatment outcomes of immunological inflammatory diseases, but their immunosuppressive effects put patients at risk for tuberculosis (TB). We investigated the risk factors for developing TB in patients treated for latent tuberculosis infection (LTBI) who also had experience of using biologic medications. At Keio University Hospital, we retrospectively investigated patients treated with anti-mycobacterial drugs before or concurrently with biologic medications from January 2012 to August 2020. Patients in the ‘follow-on cases group’ who had a positive TB screening test after initiating biologic medications and subsequently started LTBI treatment were excluded. We researched and compared the patient characteristics for TB and non-TB patient groups. Of the 146 eligible patients, 5 (3.4%) developed TB. The incidence rate was 600/100000 person-years. There were no significant differences between TB and non-TB patient groups in the history of TB, interferon-gamma release assay (IGRA), duration of biologic medication therapy, LTBI treatment periods, concomitant use of calcineurin inhibitors or anti-rheumatic drugs. The percentage of patients who received prednisolone at a dose of ≥15 mg for more than 1 month was higher in those who developed TB than in those who did not (40.0 vs. 7.1%, p = 0.054); however, this difference was not statistically significant. Regular monitoring of TB is necessary for long-term concomitant use of high prednisolone doses during and after the administration of biologic medications.

Fecal pharmacokinetics/pharmacodynamics characteristics of fidaxomicin and vancomycin against Clostridioides difficile infection elucidated by in vivo feces-based infectious evaluation models.

Tashiro S, Taguchi K, Enoki Y, Matsumoto K

Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases 29 ( 5 ) 616 - 622 2022.12

ISSN 1198-743X

Objectives: The pharmacokinetics (PK)/pharmacodynamics (PD; PK/PD) characteristics of fidaxomicin (FDX) and vancomycin (VCM) against Clostridioides difficile infection (CDI) are yet to be elucidated because of the lack of an established PK/PD analysis method for intestinal infections and unabsorbed oral drugs. Here, we developed a feces-based PK/PD analysis method and determined the fecal PK/PD index, with target values of FDX and VCM against CDI. Methods: The antimicrobial susceptibility, time-kill curves, and post-antibiotic effects (PAEs) of FDX and VCM against C. difficile were determined in vitro. The optimal fecal PK/PD indices, with target values, were determined from the results of PK and PD studies involving 5-week-old female C57BL/6J mice infected with C. difficile ATCC® 43255. The minimum inhibitory concentration (MIC) breakpoints for C. difficile were estimated based on clinical data concerning fecal antibiotic concentrations in patients with CDI. Results: FDX and VCM inhibited C. difficile growth via time-dependent antibacterial activity and exerted PAEs. In the CDI mouse model experiments, the changes in C. difficile load and clinical cures (72-hour survival rates and clinical sickness score grading) were most highly correlated with the ratio of area under the fecal drug concentration-time curve to MIC (AUC0→∞/MIC). The target AUC0→∞/MIC values of FDX and VCM for 3 log10 reduction in C. difficile load was 13,173 and 8,308, respectively. The MIC breakpoints of FDX and VCM for C. difficile was estimated to be 1.0 and 2.0 μg/mL, respectively. Conclusions: The developed in vivo feces-based PK/PD analysis method elucidated the optimal fecal PK/PD index, with target values of FDX and VCM against CDI.

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The G protein-coupled receptor ligand apelin-13 ameliorates skeletal muscle atrophy induced by chronic kidney disease.

Enoki Y, Nagai T, Hamamura Y, Osa S, Nakamura H, Taguchi K, Watanabe H, Maruyama T, Matsumoto K

Journal of cachexia, sarcopenia and muscle (Wiley) 14 ( 1 ) 553 - 564 2022.12

ISSN 2190-5991

Background: Targeting of the apelin–apelin receptor (Apj) system may serve as a useful therapeutic intervention for the management of chronic kidney disease (CKD)-induced skeletal muscle atrophy. We investigated the roles and efficacy of the apelin–Apj system in CKD-induced skeletal muscle atrophy. Methods: The 5/6-nephrectomized mice were used as CKD models. AST-120, a charcoal adsorbent of uraemic toxins (8 w/w% in diet), or apelin (1 μmol/kg) was administered to CKD mice to investigate the mechanism and therapeutic potential of apelin on CKD-induced skeletal muscle atrophy. The effect of indoxyl sulfate, a uraemic toxin, or apelin on skeletal muscle atrophy was evaluated using mouse myoblast cells (C2C12 cells) in vitro. Results: Skeletal muscle atrophy developed over time following nephrectomy at 12 weeks, as confirmed by a significant increase of atrogin-1 and myostatin mRNA expression in the gastrocnemius (GA) muscle and a decrease of lower limb skeletal muscle weight (P < 0.05, 0.01 and 0.05, respectively). Apelin expression in GA muscle was significantly decreased (P < 0.05) and elabela, another Apj endogenous ligand, tended to show a non-significant decrease at 12 weeks after nephrectomy. Administration of AST-120 inhibited the decline of muscle weight and increase of atrogin-1 and myostatin expression. Apelin and elabela expression was slightly improved by AST-120 administration but Apj expression was not, suggesting the involvement of uraemic toxins in endogenous Apj ligand expression. The administration of apelin at 1.0 μmol/kg for 4 weeks to CKD mice suppressed the increase of atrogin-1 and myostatin, increased apelin and Apj mRNA expression at 30 min after apelin administration and significantly ameliorated weight loss and a decrease of the cross-sectional area of hindlimb skeletal muscle. Conclusions: This study demonstrated for the first time the association of the Apj endogenous ligand–uraemic toxin axis with skeletal muscle atrophy in CKD and the utility of therapeutic targeting of the apelin–Apj system.

Analysis of adverse drug events in pulmonary Mycobacterium avium complex disease using spontaneous reporting system

Ozawa T., Namkoong H., Takaya R., Takahashi Y., Fukunaga K., Enoki Y., Taguchi K., Kizu J., Matsumoto K., Hasegawa N.

BMC Infectious Diseases (BMC Infectious Diseases) 22 ( 1 ) 580 2022.12

Background: In Japan, Mycobacterium avium complex lung disease (MAC-LD) is the most common in nontuberculous mycobacterial lung disease. Patients often experience adverse events, resulting in the discontinuation of treatment, which causes treatment failure. The JADER (Japanese Adverse Drug Event Report) database is a database of adverse events that allows us to collect real-world data on adverse events. We can collect large-scale data cost-effectively and detect signals of potential adverse events such as reporting odds ratio (ROR) by using spontaneous reporting systems. In this study, we aimed to elucidate the adverse events of clarithromycin (CAM), ethambutol (EB), and rifampicin (RFP) using the JADER database. Methods: We included cases of MAC-LD between April 2004 and June 2017. We investigated sex, age, and medications that may have caused the adverse events, outcomes, and time of onset. We calculated the safety signal index as the ROR. Time-to-event analysis was performed using the Weibull distribution. Results: The total number of adverse events of CAM, EB, and RFP was 2780, with 806 patients. In the overall adverse events, hematologic and lymphatic disorders were the most common adverse events, with 17.3%, followed by eye disorders (16.6%), and hepatobiliary disorders (14.0%). The outcomes were as follows: recovery, 40.0%; remission, 27.1%; non-recovery, 11.2%; and death, 7.1%. Regarding the most common onset time of CAM, EB, and RFP was within 120 days at 40%, 181–300 days at 43.6%, and within 120 days at 88.5%. For CAM, the RORs of infections and infestations, hepatobiliary system disorders, and immune system disorders were 4.13 (95% confidence interval [CI], 2.3–7.44), 2.61 (95% CI, 1.39–4.91), and 2.38 (95% CI, 1.04–5.44). For EB, the ROR of eye disorders was 215.79 (95% CI, 132.62–351.12). For RFP, the RORs of renal and urinary tract disorders and investigations were 7.03 (95% CI, 3.35–14.77) and 6.99 (95% CI, 3.22–15.18). The β value of EB was 2.07 (95% CI, 1.48–2.76), which was classified as a wear-out failure type. Conclusions: For MAC-LD, the adverse event which has the highest ROR is infections and infestations in CAM, eye disorders in EB, renal and urinary tract disorders in RFP. Adverse events of EB occur after 180 days, whereas the adverse events of CAM and RFP occur early in the course of treatment.

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Safety of linezolid in patients with decreased renal function and trough monitoring: a systematic review and meta-analysis.

Liu X, Aoki M, Osa S, Ito C, Saiki R, Nagai T, Enoki Y, Taguchi K, Matsumoto K

BMC pharmacology & toxicology 23 ( 1 ) 89 2022.11

Background: Linezolid causes hematological toxicity, mostly thrombocytopenia, which leads to treatment discontinuation and failure. Recent studies revealed that during linezolid therapy, the incidence of treatment-related hematological toxicity is significantly higher in patients with decreased renal function (DRF) than in those with normal renal function. Linezolid monitoring is necessary due to the high frequency of hematological toxicity in patients with DRF and the relationship between blood concentration and safety. We performed a systematic review and meta-analysis to evaluate the safety correlation between DRF and trough monitoring. Methods: Articles published before June 24, 2022, on MEDLINE, Web of Sciences, Cochrane Register of Controlled Trials, and ClinicalTrials.gov were systematically analyzed. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using the Mantel–Haenszel method and the variable effects model. Results: The incidence of hematological toxicity was significantly higher in patients with DRF than in those without DRF (OR = 2.37; p < 0.001). Subgroup analysis, performed according to hematotoxicity classification, including thrombocytopenia, anemia, and pancytopenia, revealed a significantly higher incidence of thrombocytopenia (OR = 2.45; p < 0.001) and anemia (OR = 2.31; p = 0.006) in patients with DRF than in those without; pancytopenia (OR = 1.41; p = 0.80) incidences were not significantly higher. Based on a systematic review, linezolid trough concentrations > 6–7 μg/mL may be associated with an increased incidence of thrombocytopenia. However, no confidential threshold values for the development of thrombocytopenia were found in the area under the concentration curve values for children or adults. Conclusion: We observed a high frequency of hematological toxicity during linezolid therapy in patients with DRF. To ensure safety, linezolid trough concentrations should be ≤6–7 μg/mL.

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Sciatic denervation-induced skeletal muscle atrophy is associated with persistent inflammation and increased mortality during sepsis.

Osa S, Enoki Y, Miyajima T, Akiyama M, Fujiwara Y, Taguchi K, Kim YG, Matsumoto K

Shock (Augusta, Ga.) (Ovid Technologies (Wolters Kluwer Health)) 59 ( 3 ) 417 - 425 2022.11

ISSN 1073-2322

Background: Patients with underlying skeletal muscle atrophy are likely to develop aggravated sepsis. However, no study has experimentally verified the association between the prognosis of sepsis and muscle atrophy, and the mechanism of aggravation of sepsis under muscle atrophy remains unclear. In this study, we investigated the effect of skeletal muscle atrophy induced by sciatic denervation (DN), an experimental muscle atrophy model, on sepsis prognosis. Methods: Skeletal muscle atrophy was induced by DN of the sciatic nerve in C57BL/6J male mice. Cecal ligation and puncture (CLP) was performed to induce sepsis. Results: The survival rates of the sham and DN groups 7 days after CLP were 63% and 35%, respectively, wherein an approximately 30% reduction was observed in the DN group (P < 0.05, vs. sham-CLP). The DN group had a higher bacterial count in the blood 48 h after CLP (P < 0.05, vs. sham-CLP). Notably, NOx (a metabolite of nitric oxide) concentrations in DN mice were higher than those in sham mice after CLP (P < 0.05, vs. sham-CLP), whereas serum platelet levels were lower 48 h after CLP (P < 0.05, vs. sham-CLP). In organ damage analysis, DN mice presented increased protein expression of the kidney injury molecule (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL), a kidney injury marker, after CLP (NGAL 48 h after CLP, P < 0.05, vs. sham-CLP; KIM-1 24 h after CLP, P < 0.01, vs. sham-CLP). Furthermore, nitro tyrosine levels in the kidneys of DN mice were higher 48 h after CLP compared with those in sham-CLP mice, indicating the accumulation of nitrative stress (P < 0.05, vs. sham-CLP). Serum cytokine levels were increased in both groups after CLP, but decreased in the sham group 48 h after CLP and remained consistently higher in the DN group (tumor necrosis factor [TNF]-α: P < 0.05, sham-CLP vs. DN-CLP; interleukin (IL)-1β: P < 0.01, sham-CLP vs. DN-CLP; IL-6: P < 0.05, DN vs. DN-CLP; IL-10: P < 0.05, sham-CLP vs. DN-CLP). Conclusions: We verified that skeletal muscle atrophy induced by DN is associated with poor prognosis after CLP-induced sepsis. Importantly, mice with skeletal muscle atrophy presented worsening sepsis prognosis at late onset, including prolonged infection, persistent inflammation, and kidney damage accumulation, resulting in delayed recovery.

Differences in Pharmacokinetic/Pharmacodynamic Parameters of Tedizolid Against VRE and MRSA.

Liu X, Tashiro S, Igarashi Y, Takemura W, Kojima N, Morita T, Hayashi M, Enoki Y, Taguchi K, Matsumoto K

Pharmaceutical research 40 ( 1 ) 187 - 196 2022.11

ISSN 0724-8741

Purpose: Vancomycin-resistant enterococci (VRE) have recently become a major cause of nosocomial infections and a global public health concern. Tedizolid exhibits powerful antibacterial activity against VRE in vitro, but its pharmacokinetic/pharmacodynamic (PK/PD) parameters remain unclear. Therefore, we aimed to determine the PK/PD indices of tedizolid action on VRE and the mechanisms underlying the PK/PD indices differences of tedizolid against VRE and methicillin-resistant Staphylococcus aureus (MRSA). Methods: Optimal PK/PD target values of tedizolid were determined in vitro, based on time-kill curves and post-antibiotic effects (PAEs), and in vivo, using mouse models of thigh infection with VRE and MRSA strains. Results: The tedizolid bactericidal activity on VRE and MRSA was time-dependent. Correlations were closest between fAUC24/MIC and the tedizolid PK/PD index against MRSA and VRE. To achieve 1 log10 kill tedizolid fAUC24/MIC in neutropenic mouse models of thigh infection with VRE and MRSA should be 14.2 and 138.5, respectively. The PAEs of tedizolid against VRE and MRSA were 2.39 and 0.99 h, respectively. Conclusion: Tedizolid showed bactericidal effects against VRE even in neutropenic mice unlike MRSA, which could be attributed to its longer PAE against VRE. Hence, we hypothesize that tedizolid treatment against VRE infections is promising for achieving therapeutic success in clinical.

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In vitro effects of diazabicyclooctane β-lactamase inhibitors relebactam and nacubactam against three subspecies of Mycobacterium abscessus complex

Misawa K., Nishimura T., Kashimura S., Enoki Y., Taguchi K., Uno S., Uwamino Y., Matsumoto K., Hasegawa N.

International Journal of Antimicrobial Agents (International Journal of Antimicrobial Agents) 60 ( 5-6 ) 106669 2022.11

ISSN 09248579

Background: Mycobacterium abscessus complex (MABC) pulmonary disease is notoriously difficult to treat due to intrinsic resistance to many common antibiotics. MABC is β-lactam-resistant as it produces class A β-lactamases, such as blaMab, which are inhibited by diazabicyclooctane (DBO) β-lactamase inhibitors. Objectives: To investigate the microbiological effects of the combination of β-lactam and DBO β-lactamase inhibitors (relebactam and nacubactam) against MABC and determine if the effects are associated with the MABC subspecies and colony morphotype. Methods: The antimicrobial susceptibility of three type strains and 20 clinical isolates of MABC to the combination of seven β-lactams with relebactam or nacubactam was evaluated using broth microdilution checkerboard assays. For these strains, expression levels of blaMab were assessed using quantitative real-time polymerase chain reaction and genotypic diversity was evaluated using 18-locus variable number tandem repeat assay. Results: Relebactam and nacubactam lowered the minimum inhibitory concentrations of β-lactams, particularly imipenem, meropenem, and tebipenem, against MABC. There was no difference in efficacy of combination treatment between three subspecies, but rough morphotypes tended to be less susceptible than smooth morphotypes. There were no differences in blaMab expression levels and genotypic diversity between the morphotypes. Conclusions: The combination of β-lactam with relebactam or nacubactam improved the efficacy of β-lactams against all MABC subspecies, but higher concentrations of β-lactams were needed for rough morphotypes.

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Oral fidaxomicin versus vancomycin for the treatment of Clostridioides difficile infection: A systematic review and meta-analysis of randomized controlled trials

Tashiro S., Mihara T., Sasaki M., Shimamura C., Shimamura R., Suzuki S., Yoshikawa M., Hasegawa T., Enoki Y., Taguchi K., Matsumoto K., Ohge H., Suzuki H., Nakamura A., Mori N., Morinaga Y., Yamagishi Y., Yoshizawa S., Yanagihara K., Mikamo H., Kunishima H.

Journal of Infection and Chemotherapy (Journal of Infection and Chemotherapy) 28 ( 11 ) 1536 - 1545 2022.11

ISSN 1341321X

Background: Fidaxomicin (FDX) has received considerable attention as a novel therapeutic alternative agent to vancomycin (VCM) for Clostridioides difficile infection (CDI). However, the superiority and efficacy profile of FDX are not sufficiently determined by high-quality evidence. This study aimed to clarify the superiority of FDX for CDI treatment through a systematic review and meta-analysis. Methods: We conducted a meta-analysis of randomized controlled trials (RCTs) which evaluated the efficacy and safety of FDX and VCM in patients with CDI. Electronic databases (PubMed, Cochrane Library, Web of Science, and Clinicaltrials.gov) were searched for studies published until October 15, 2021. The primary endpoint was global cure. The secondary endpoints were clinical cure, recurrence, and adverse event. Risk ratios (RRs), risk differences (RDs), and 95% confidence intervals were calculated using Mantel-Haenszel random-effects model. The risk of bias was assessed using Cochrane Handbook for Systematic Reviews of Interventions and Assessment Criteria. Results: Six RCTs were included in this meta-analysis. Compared to VCM, FDX was associated with significantly higher global cure rates (RR = 1.18, P < 0.00001; RD = 0.11, 95% CI = 0.07–0.16). In addition, clinical cure rates were comparable between FDX and VCM (P = 0.31). FDX was associated with significantly lower recurrence rates compared to VCM (RR = 0.59, P < 0.0001). In addition, adverse event rates were not significantly different between the drugs (P = 0.41). Conclusion: FDX achieves significantly higher global cure rates and lower recurrence rates and is comparable to VCM in clinical cure rates and adverse event rates in patients with CDI. Collectively, FDX is superior to VCM as a therapeutic agent for CDI.

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Efficacy of surgical skin preparation with chlorhexidine in alcohol according to the concentration required to prevent surgical site infection: meta-analysis

Hasegawa T., Tashiro S., Mihara T., Kon J., Sakurai K., Tanaka Y., Morita T., Enoki Y., Taguchi K., Matsumoto K., Nakajima K., Takesue Y.

BJS open (BJS open) 6 ( 5 ) 2022.09

ISSN 2474-9842

BACKGROUND: A combination of chlorhexidine gluconate and alcohol (CHG-alcohol) is recommended for surgical skin preparation to prevent surgical site infection (SSI). Although more than 1 per cent CHG-alcohol is recommended to prevent catheter-related bloodstream infections, there is no consensus regarding the concentration of the CHG compound for the prevention of SSI. METHODS: A systematic review and meta-analysis was performed. Four electronic databases were searched on 5 November 2020. SSI rates were compared between CHG-alcohol and povidone-iodine (PVP-I) according to the concentration of CHG (0.5 per cent, 2.0 per cent, 2.5 per cent, and 4.0 per cent). RESULTS: In total, 106 of 2716 screened articles were retrieved for full-text review. The risk ratios (RRs) of SSI for 0.5 per cent (6 studies) and 2.0 per cent (4 studies) CHG-alcohol were significantly lower than those for PVP-I (RR = 0.71, 95 per cent confidence interval (c.i.) 0.52 to 0.97; RR = 0.52, 95 per cent c.i 0.31 to 0.86 respectively); however, no significant difference was observed in the compounds with a CHG concentration of more than 2.0 per cent. CONCLUSIONS: This meta-analysis is the first study that clarifies the usefulness of an alcohol-based CHG solution with a 0.5 per cent or higher CHG concentration for surgical skin preparation to prevent SSI.

Liposomal methemoglobin as a potent antidote for hydrogen sulfide poisoning

Suzuki Y., Taguchi K., Kure T., Enoki Y., Otagiri M., Sakai H., Matsumoto K.

Toxicology and Applied Pharmacology (Toxicology and Applied Pharmacology) 450 116159 2022.09

ISSN 0041008X

Hydrogen sulfide (H2S) induces acute and lethal toxicity at high concentrations. However, no specific antidotes for H2S poisoning have been approved. Liposomal methemoglobin (metHb@Lipo) was developed as an antidote for cyanide poisoning. As the toxic mechanism of H2S poisoning is the same as that of cyanide poisoning, metHb@Lipo could potentially be used as an antidote for H2S poisoning. In this study, we evaluated the antidotal efficacy of metHb@Lipo against H2S poisoning. Stopped-flow rapid-scan spectrophotometry clearly showed that metHb@Lipo scavenged H2S rapidly. Additionally, metHb@Lipo showed cytoprotective effects against H2S exposure in H9c2 cells by maintaining mitochondrial function. MetHb@Lipo treatment also improved the survival rate after H2S exposure in vivo, with the maintenance of cytochrome c oxidase activity and suppression of metabolic acidosis. Moreover, metHb@Lipo therapy maintained significant antidotal efficacy even after 1-year-storage at 4–37 °C. In conclusion, metHb@Lipo is a candidate antidote for H2S poisoning.

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Methemoglobin-albumin clusters for the treatment of hydrogen sulfide intoxication

Suzuki Y., Taguchi K., Okamoto W., Enoki Y., Komatsu T., Matsumoto K.

Journal of Controlled Release (Journal of Controlled Release) 349 304 - 314 2022.09

ISSN 01683659

Hydrogen sulfide (H2S) has attracted significant attention as a seed in drug development. However, H2S is toxic and induces lethal acute intoxication. Here, we developed methemoglobin (metHb)-albumin clusters as detoxifying agents for H2S intoxication, which were designed based on the inherent binding property of metHb with H2S. The metHb-albumin clusters comprising an autoxidized ferric Hb center wrapped covalently with an average of three human serum albumins showed a similar H2S binding affinity to that of naked metHb. Owing to the H2S binding capability, metHb-albumin clusters suppressed cell death induced by H2S exposure while maintaining mitochondrial function in H9c2 cells. In addition, lethal H2S intoxication model mice were rescued by a single administration of metHb-albumin clusters, resulting from the recovery of cytochrome c oxidase activity. Furthermore, the metHb-albumin clusters possessed essential characteristics, such as adequate pharmacokinetic properties and biocompatibility, for their use as detoxifying agents against H2S intoxication. In conclusion, the results obtained in this study suggest that metHb-albumin clusters are promising detoxifying agents for H2S intoxication and that harnessing the inherent H2S binding properties of metHb is an innovative approach to develop detoxifying agents for H2S intoxication.

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Exploring the Factors Affecting the Transferability of Vancomycin to Cerebrospinal Fluid in Postoperative Neurosurgical Patients with Bacterial Meningitis

Ichinose Naoki, Shinoda Kozue, Yoshikawa Gakushi, Fukao Eri, Enoki Yuki, Taguchi Kazuaki, Oda Toshimi, Tsutsumi Kazuo, Matsumoto Kazuaki

Biological and Pharmaceutical Bulletin (The Pharmaceutical Society of Japan) 45 ( 9 ) 1398 - 1402 2022.09

ISSN 09186158

Vancomycin (VCM) is a standard treatment for bacterial meningitis. However, little is known about the transferability of VCM to cerebrospinal fluid (CSF), thus evidence of the transferability of VCM to CSF during bacterial meningitis is needed. In this study, we evaluated the concentration of VCM in the plasma and CSF of postoperative neurosurgical patients with bacterial meningitis and evaluated the factors that affect the transferability of VCM to CSF. The concentrations of VCM in plasma (trough) and CSF were determined in eight patients (four males and four females) with bacterial meningitis who were treated with VCM using HPLC. The ratio of the VCM concentrations in CSF/plasma was also calculated by estimating the blood VCM concentration at the same time as the VCM concentration in CSF was measured. The results showed that the VCM concentration in CSF was 0.9–12.7 µg/mL and the CSF/plasma VCM concentration ratio was 0.02–0.62. We examined the effect of drainage on the transferability of VCM to CSF, which showed that the VCM concentration in CSF and the CSF/plasma VCM concentration ratio were significantly higher in patients not undergoing drainage than in patients who were undergoing drainage. The CSF protein and glucose concentrations, which are diagnostic indicators of meningitis, were positively correlated with the VCM concentration in CSF and the CSF/plasma VCM concentration ratio. Thus, VCM transferability to CSF may be affected by changes in the status of the blood–brain barrier and blood–cerebrospinal fluid barrier due to drainage or meningitis.

Concentration-Dependent Activity of Pazufloxacin against Pseudomonas aeruginosa: An In Vivo Pharmacokinetic/Pharmacodynamic Study.

Umezaki Y, Matsumoto K, Ikawa K, Yokoyama Y, Enoki Y, Shigemi A, Watanabe E, Nakamura K, Ueno K, Terazono H, Morikawa N, Takeda Y

Antibiotics (Basel, Switzerland) (Antibiotics) 11 ( 7 ) 2022.07

The bacterium Pseudomonas aeruginosa is known to be associated with nosocomial infections around the world. Pazufloxacin, a potent DNA gyrase inhibitor, is known to be an effective drug candidate. However, it has not been clarified whether the pharmacokinetic (PK)/pharmacodynamic (PD) of pazufloxacin was effective against P. aeruginosa. Herein, we demonstrated that the PK/PD index of pazufloxacin against P. aeruginosa infection is used to optimize the dosing regiments. We constructed an in vivo infection model by infecting P. aeruginosa into the thigh of a mouse to determine the PD, and we measured the serum concentration of pazufloxacin to construct the PK model using high-performance liquid chromatography. The therapeutic efficacy of pazufloxacin was correlated with the ratio of the area under the free concentration time curve at 24 h to the minimum inhibitory concentration (fAUC24/MIC), and the maximum free concentration to the MIC (fCmax/MIC). Each contribution rate (R2) was 0.72 and 0.65, respectively, whereas the time at which the free drug concentration remained above the MIC (R2 = 0.28). The target value of pazufloxacin fAUC24/MIC for stasis was 46.1, for 1 log10 it was 63.8, and for 2 log10 it was 100.8. Moreover, fCmax/MIC for stasis was 5.5, for 1 log10 it was 7.1, and for 2 log10 it was 10.8. We demonstrated that the in vivo concentration-dependent activity of pazufloxacin was effective against the P. aeruginosa infection, and successfully made the PK/PD model sufficiently bactericidal. The PK/PD model will be beneficial in preventing the spread of nosocomial infections.

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Target Therapeutic Ranges of Anti-MRSA Drugs, Linezolid, Tedizolid and Daptomycin, and the Necessity of TDM

Matsumoto Kazuaki, Samura Masaru, Tashiro Sho, Shishido Shino, Saiki Reika, Takemura Wataru, Misawa Kana, Liu Xiaoxi, Enoki Yuki, Taguchi Kazuaki

Biological and Pharmaceutical Bulletin (The Pharmaceutical Society of Japan) 45 ( 7 ) 824 - 833 2022.07

ISSN 09186158

The target therapeutic ranges of vancomycin, teicoplanin, and arbekacin have been determined, and therapeutic drug monitoring (TDM) is performed in clinical practice. However, TDM is not obligatory for daptomycin, linezolid, or tedizolid. In this study, we examined whether TDM will be necessary for these 3 drugs in the future. There was no significant difference in therapeutic effects on acute bacterial skin and skin structure infection between linezolid and tedizolid by meta-analysis. Concerning the therapeutic effects on pneumonia, the rate of effectiveness after treatment with tedizolid was significantly lower than with linezolid. With respect to safety, the incidences of gastrointestinal adverse events and blood/lymphatic system disorders related to tedizolid were significantly lower than those related to linezolid. Linezolid exhibits potent therapeutic effects on pneumonia, but the appearance of adverse reactions is indicated as a problem. There was a dose-dependent decrease in the platelet count, and the target trough concentration (Ctrough) was estimated to be 4–6 or 2–7 µg/mL in accordance with the patient’s condition. The efficacy of linezolid may be obtained while minimizing the appearance of adverse reactions by performing TDM. The target therapeutic range of tedizolid cannot be achieved in immunocompromised or severe patients. Therefore, we concluded that TDM was unnecessary, considering step-down therapy with oral drugs, use in non-severe patients, and high-level safety. Concerning daptomycin, high-dose administration is necessary to achieve an area under the curve (AUC) of ≥666 as an index of efficacy. To secure its safety, Ctrough (<20 µg/mL) monitoring is important. Therefore, TDM is necessary.

Self-medication Tax System Based on Vital Statistics: Exploration through Survey

Taguchi Kazuaki, Enoki Yuki, Hori Satoko, Yamaura Katsunori, Matsumoto Kazuaki

Iryo Yakugaku (Japanese Journal of Pharmaceutical Health Care and Sciences) (Japanese Society of Pharmaceutical Health Care and Sciences) 48 ( 7 ) 276 - 283 2022.07

ISSN 1346-342X

The self-medication tax system is a new tax policy system that came into effect in 2017. The dissemination of this tax system is expected to promote changes in the people’s behavior toward self-medication and contribute to the optimization of healthcare costs. This study aimed to conduct an anonymous self-administered questionnaire survey on the self-medication tax system for 3,000 people, assigned based on vital statistics in an online survey system, and extract the reality of and issues surrounding the tax system. The results showed that approximately 55％ of the survey participants were aware of the self-medication tax system, but only 6％ were aware of all the application requirements for the tax system. This indicated that there was a misunderstanding among those who were familiar with the tax system. In addition, among the conditions for applying the system, the percentage of switch from over the counter drug purchases that met the application requirements was significantly lower than those of the other two requirements. Furthermore, 103 survey participants had received income deductions under the self-medication tax system, indicating that some potential applicants meet all the application requirements. The self-medication tax system was partially revised on January 1, 2022, with the application procedure partially simplified and the target products expanded. It is expected that these revisions will henceforth serve as a driving force to promote self-medication and popularize this tax system.

Trimethoxy Trityl Groups as a Potent Substituent for Anti-cancer Cytidine Analog Prodrugs.

Ito C, Taguchi K, Moroi Y, Enoki Y, Tokuda R, Yamasaki K, Imoto S, Matsumoto K

Journal of pharmaceutical sciences (Journal of Pharmaceutical Sciences) 111 ( 8 ) 2201 - 2209 2022.05

ISSN 0022-3549

Methoxy trityl groups are acid-responsive protecting groups that are routinely used in the process of nucleoside analog synthesis. This study investigated the potential of methoxy trityl groups, monomethoxy trityl (MMT), dimethoxy trityl (DMT), and trimethoxy trityl (TMT), as acid-responsive substituents for designing anti-cancer cytidine analog prodrugs. For this purpose, we synthesized six gemcitabine (GEM) derivatives, which were modified either 4-(N)- or 5′-(O)-sites with MMT, DMT, and TMT, as candidates for anti-cancer cytidine analog prodrugs. In vitro dissociation test of methoxy trityl groups clearly showed that the acid responsivity of the methoxy trityl moieties was in the order TMT>DMT>MMT. Furthermore, the rate of 5′-(O)-methoxy tritylation was higher than that of 4-(N)-methoxy tritylation. Along with high acid-responsivity, trimethoxy trityl-O-GEM (TMT-O-GEM) showed superior cytotoxicity against 2D cultured human breast cancer cells (MCF-7 and MDA-MB-231) and human pancreatic cancer cells (AsPC-1) compared to other methoxy-tritylated GEM derivatives. Moreover, TMT-O-GEM suppressed the growth of MCF-7 spheroids compared with trimethoxy trityl-N-GEM (TMT-N-GEM). Both TMT-O-GEM and TMT-N-GEM were negligibly deprotected and metabolized in mouse or human serum after 72 h, indicating that trimethoxy tritylation inhibits deamination by cytidine deaminase. These results indicate that 5′-(O)-trimethoxy tritylation is a potent approach for the development of anti-cancer cytidine analog prodrugs.

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Influences of protein levels on the cerebrospinal fluid distribution of ceftazidime & ceftriaxone in the cerebrospinal fluid of patients with inflamed meningitis.

Ichinose N, Yoshikawa G, Fukao E, Takahata T, Ichisawa M, Enoki Y, Taguchi K, Oda T, Tsutsumi K, Matsumoto K

Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy (Journal of Infection and Chemotherapy) 28 ( 8 ) 1216 - 1219 2022.05

ISSN 1341-321X

Introduction: Ceftazidime and ceftriaxone are used to treat various gram-negative pathogens, such as Streptococcus pneumoniae and Pseudomonas aeruginosa, and have shown excellent therapeutic efficacy against bacterial meningitis. However, there is insufficient information on the pharmacokinetic characteristics of their cerebrospinal distribution. Here, we investigated the association of clinical laboratory data in cerebrospinal fluid with ceftazidime and ceftriaxone concentration in the cerebrospinal fluid of patients with inflamed meningitis. Methods: Cerebrospinal fluid samples were collected from eight adult patients with inflamed meningitis who intravenously received either ceftazidime or ceftriaxone (ceftazidime: a total of 25 samples from three patients, ceftriaxone: a total of 12 samples from five patients). Total cell number, protein concentration, and glucose concentration in the cerebrospinal fluid were retrospectively collected from electronic medical charts. All ceftazidime and ceftriaxone concentrations in the cerebrospinal fluid were determined using high-performance liquid chromatography. Results: Both ceftazidime and ceftriaxone concentrations in cerebrospinal fluid correlated with protein concentration in cerebrospinal fluid; however, no significant correlation was observed in total cell number and glucose concentration in cerebrospinal fluid. Conclusions: This is the first report on the relationship between the cerebrospinal distribution of these antibiotics and clinical laboratory data in cerebrospinal fluid of adult patients with meningitis.

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Oxidized liposomal artificial red blood cells rescue azide-poisoned mice from lethal toxidrome by recovering cytochrome c oxidase activity

Suzuki Yuto, Taguchi Kazuaki, Hanyu Satomi, Kure Tomoko, Enoki Yuki, Otagiri Masaki, Sakai Hiromi, Matsumoto Kazuaki

JOURNAL OF DRUG DELIVERY SCIENCE AND TECHNOLOGY (Journal of Drug Delivery Science and Technology) 71 2022.05

ISSN 1773-2247

Exposure to azide compounds causes inhibition of cytochrome c oxidase in the mitochondria, leading to acute lethal poisoning. Although urgent pharmaceutical intervention is required for rescue from azide poisoning, no antidote exists worldwide. We hypothesized that methemoglobin (metHb) can be a promising material as an antidote for azide poisoning because metHb can strongly bind to azide. However, metHb administration is not feasible owing to in vivo instability and toxicity. We aimed to develop a feasible metHb-based antidote for azide poisoning, in which the inner hemoglobin of liposomal artificial red blood cells is oxidized by mixing with sodium nitrite. From the stopped-flow spectrophotometry analysis, as-prepared oxidized liposomal artificial red blood cells, which encapsulated metHb into the liposome (metHb@Lipo), the binding affinity of metHb@Lipo to azide was comparable to that of bare metHb. In addition, detoxification by metHb@Lipo increased the survival rate in lethal azide-poisoned model mice with recovery of cytochrome c oxidase activity, leading to the amelioration of acidosis and tissue oxidation. Furthermore, metHb@Lipo detoxification functioned even after 1 year of storage in a ready-to-use formulation. These results indicate that oxidized liposomal artificial red blood cells are a potent antidote for azide poisoning with favorable properties for use in critical care medicine.

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Efficacy and Safety of Daptomycin versus Vancomycin for Bacteremia Caused by Methicillin-Resistant Staphylococcus&amp;nbsp;aureus with Vancomycin Minimum Inhibitory Concentration &gt; 1 µg/mL: A Systematic Review and Meta-Analysis.

Samura M, Kitahiro Y, Tashiro S, Moriyama H, Hamamura Y, Takahata I, Kawabe R, Enoki Y, Taguchi K, Takesue Y, Matsumoto K

Pharmaceutics (Pharmaceutics) 14 ( 4 ) 2022.03

ISSN 1999-4923

This systematic review and meta-analysis compares the efficacy of daptomycin and van-comycin in adult patients with bacteremia by methicillin-resistant Staphylococcus aureus (MRSA) with vancomycin minimum inhibitory concentration (MIC) > 1 µg/mL. We searched the PubMed, Web of Science, Cochrane Library, and ClinicalTrials.gov databases on 12 May 2020. All-cause mortality (primary outcome) and treatment success rates were compared and subgroups stratified by infection source risk level and method of vancomycin susceptibility testing were also analyzed. Seven studies (n = 907 patients) were included in this efficacy analysis. Compared with vancomycin, daptomycin treatment was associated with significantly lower mortality (six studies, odds ratio (OR) 0.53, 95% confidence interval (CI) 0.29–0.98) and higher treatment success (six studies, OR 2.20, 95% CI 1.63–2.96), which was consistent regardless of the vancomycin MIC test method used. For intermediate-risk sources, daptomycin was a factor increasing treatment success compared with vancomycin (OR 4.40, 95% CI 2.06–9.40), and it exhibited a trend toward a higher treatment success rate for high-risk sources. In conclusion, daptomycin should be considered for the treatment of bacteremia caused by MRSA with vancomycin MIC > 1 µg/mL, especially in patients with intermediate-and high-risk bacteremia sources.

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Neurotoxicity associated with colistin methanesulfonate treatment is enhanced by concomitant sevoflurane inhalation

Gotoda M., Enoki Y., Shishido S., Taguchi K., Matsumoto K.

Toxicology Reports (Toxicology Reports) 9 1255 - 1260 2022.01

ISSN 22147500

Colistin methanesulfonate (CMS) is a cyclic polypeptide antibiotic with neurotoxic side effects. Sevoflurane (Sevo), an inhaled anesthetic, is known to enhance the non-depolarizing effect of neuromuscular relaxants; however, its mechanism of action is unclear. In this study, we investigated the augmentation effect of Sevo on CMS-induced neurotoxicity. We prepared a sciatic nerve-skeletal muscle stimulation model using Sprague-Dawley male rats administered CMS with or without Sevo. The muscle contraction inhibition rate was determined from electromyogram measurements. Furthermore, we simulated the pharmacokinetics of CMS and colistin using previous reports, and the relationship between the effect of muscle contraction inhibition and pharmacokinetic parameters was evaluated. We observed a dose-dependent neuromuscular inhibitory effect of Sevo under CMS administration. The 50 % inhibitory dose (ID50) values for CMS and CMS+Sevo were 167 ± 12 and 85 ± 5 mg/kg, respectively. The combination of CMS with Sevo showed a 49 % decrease in the ID50 compared with CMS alone. The simulated area under the time–concentration curve (AUC) values for CMS and colistin administration in rats at 200 mg/kg were 219 and 16.0 mg·h/L, respectively. The predicted AUC values of colistin corresponding to the ID50 at 0–45 min for CMS alone and CMS+Sevo were 12.0 and 7.0 mg·h/L, respectively. We revealed that the neurotoxic effect of CMS was enhanced by the concomitant use of Sevo. Based on the simulated AUC values, we concluded that this neurotoxic effect may also occur in clinical settings, and concomitant use of CMS and Sevo should be avoided.

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Liposomal Artificial Red Blood Cell-Based Carbon Monoxide Donor Is a Potent Renoprotectant against Cisplatin-Induced Acute Kidney Injury.

Taguchi K, Suzuki Y, Tsutsuura M, Hiraoka K, Watabe Y, Enoki Y, Otagiri M, Sakai H, Matsumoto K

Pharmaceutics (MDPI AG) 14 ( 1 ) 57 - 57 2021.12

Research paper (scientific journal), Accepted, ISSN 1999-4923

Cisplatin (CDDP) is an essential anti-tumor agent for chemotherapeutic regimens against various types of cancer. However, the progression of nephrotoxicity, which is the main adverse effect of CDDP, leads to discontinuation of CDDP chemotherapy. Therefore, development of a renoprotectant against CDDP-induced nephrotoxicity is crucial. Here, the potential of a carbon monoxide (CO)-loaded hemoglobin-vesicle (CO-HbV) as a renoprotectant for CDDP-induced nephrotoxicity was evaluated for its renoprotective effects against CDDP-induced nephrotoxicity, inhibitory effects on the anti-tumor activity of CDDP, and anti-tumor activity. In healthy mice, after pretreatment with either saline, HbV, or CO-HbV prior to CDDP administration, only the CO-HbV pretreatment group ameliorated the progression of CDDP-induced nephrotoxicity by suppressing apoptosis via caspase-3. In experiments using B16-F10 melanoma cells, the half-maximal inhibitory concentration of CDDP decreased with co-incubation with CO-HbV, owing to the anti-tumor activity of CO. CO-HbV pretreatment had no impact on the anti-tumor activity of CDDP in B16-F10 melanoma cell-bearing mice, which was consistent with the results of the cell experiment. Furthermore, CO-HbV pretreatment improved body growth and survival rates. In conclusion, CO-HbV pretreatment is a potent renoprotectant for CDDP-induced nephrotoxicity, allowing treatment with CDDP to be conducted without failure of cancer treatment.

Incidence of elevated creatine phosphokinase between daptomycin alone and concomitant daptomycin and statins: A systematic review and meta-analysis.

Samura M, Takada K, Hirose N, Kurata T, Nagumo F, Koshioka S, Ishii J, Uchida M, Inoue J, Enoki Y, Taguchi K, Tanikawa K, Matsumoto K

British journal of clinical pharmacology (Wiley) 88 ( 5 ) 1985 - 1998 2021.12

Research paper (scientific journal), Joint Work, Accepted, ISSN 0306-5251

Aims

The present systematic review and meta‐analysis evaluated the incidence of elevated creatine phosphokinase (CPK) levels between daptomycin alone and concomitant daptomycin and statin use.

Methods

We searched the PubMed, Web of Sciences, Cochrane Library and ClinicalTrials.gov databases. We analysed the incidence of elevated CPK between daptomycin alone and concomitant daptomycin and statins among studies defining CPK elevation as levels ≥ the upper limit of normal (ULN) or ≥5× ULN. We also analysed the incidence of rhabdomyolysis between the groups. We then calculated the odds ratios (ORs) and 95% confidence intervals (CIs) based on the included studies.

Results

Comparing CPK elevation defined as CPK levels ≥ULN, a significantly higher incidence of CPK elevation was observed with concomitant daptomycin and statin use than with daptomycin alone (OR = 2.55, 95% CI 1.78–3.64, P < .00001, I2 = 0%). Likewise, when CPK elevation was defined as CPK levels ≥5× ULN, a significantly higher incidence of CPK elevation was detected with concomitant daptomycin and statin use than with daptomycin alone (OR = 1.89, 95% CI 1.06–3.35, P = .03, I2 = 48%). The incidence of rhabdomyolysis was significantly higher following concomitant daptomycin and statin use than with daptomycin alone (OR = 11.60, 95% CI 1.81–74.37, P = .01, I2 = 0%).

Conclusion

The combined use of daptomycin and statins were significant risk factors for the incidence of CPK elevation defined as levels ≥ULN or ≥5× ULN and rhabdomyolysis.

Bioinspired carbon monoxide delivery using artificial blood attenuates the progression of obliterative bronchiolitis via suppression of macrophage activation by IL-17A.

Watabe Y, Taguchi K, Sakai H, Enoki Y, Maruyama T, Otagiri M, Kohno M, Matsumoto K

European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V (Elsevier BV) 170 43 - 51 2021.12

Research paper (scientific journal), Joint Work, Accepted, ISSN 0939-6411

Carbon monoxide (CO) is expected to attenuate the progression of obliterative bronchiolitis (OB), which is a serious complication after lung transplantation. However, issues in terms of feasible exogenous CO supply, such as continuousness and safety, remain unsolved. Here, we applied nano red blood cells, namely hemoglobin vesicles (Hb-V), as a CO cargo based on the biomimetic concept and investigated the therapeutic potential of CO-loaded Hb-V on OB in orthotopic tracheal transplant model mice. The CO-loaded Hb-V was comprised of negatively charged liposomes encapsulating carbonylhemoglobin with a size of ca. 220 nm. The results of histological evaluation showed that allograft luminal occlusion and fibrosis were significantly ameliorated by treatment with CO-loaded Hb-V compared to treatment with saline, cyclosporine, and Hb-V. The therapeutic effects of CO-loaded Hb-V on OB were due to the suppression of M1 macrophage activation in tracheal allografts, resulting from decreased IL-17A production. Furthermore, the expression of TNF-α and TGF-β in tracheal allografts was decreased by CO-loaded Hb-V treatment but not saline and Hb-V treatment, indicating that CO liberated from CO-loaded Hb-V inhibits epithelial-mesenchymal transition. These findings suggest that CO-loaded Hb-V exerts strong therapeutic efficacy against OB via the regulation of macrophage activation by IL-17A and TGF-β-driven epithelial-mesenchymal transition.

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Cefmetazole as an Alternative to Carbapenems Against Extended-Spectrum Beta-Lactamase-Producing Escherichia coli Infections Based on In Vitro and In Vivo Pharmacokinetics/Pharmacodynamics Experiments.

Takemura W, Tashiro S, Hayashi M, Igarashi Y, Liu X, Mizukami Y, Kojima N, Morita T, Enoki Y, Taguchi K, Yokoyama Y, Nakamura T, Matsumoto K

Pharmaceutical research (Pharmaceutical Research) 38 ( 11 ) 1839 - 1846 2021.12

Research paper (scientific journal), Joint Work, Accepted, ISSN 0724-8741

Purpose: Cefmetazole (CMZ) has received attention as a pharmaceutical intervention for extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-EC) infections. This study aimed to investigate the pharmacokinetics/pharmacodynamics (PK/PD) characteristics of CMZ against ESBL-EC. Methods: The susceptibility and time-killing activity of CMZ against clinically isolated ESBL-EC (EC9 and EC19) were determined in vitro. The optimal PK/PD index and its target value were calculated based on the results of a PK study in healthy mice and PD study in neutropenic murine thigh infection model mice. Results: The minimum inhibitory concentrations (MICs) of CMZ against EC9 and EC19 were 2.0 and 1.0 µg/mL, respectively. Time–kill studies showed that colony-forming units decreased in a time-dependent manner at CMZ concentrations in the range of 4–64 × MIC. In in vivo PK/PD studies, the antibacterial effect of CMZ showed the better correlation with the time that the free drug concentration remaining above the MIC (fT>MIC), with the target values for a static effect and 1 log10 kill reduction calculated as 57.6% and 69.6%, respectively. Conclusion: CMZ possesses time-dependent bactericidal activities against ESBL-EC and is required to achieve “fT>MIC” ≥ 69.6% for the treatment of ESBL-EC infections.

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Identification of Risk Factors for Daptomycin-Associated Creatine Phosphokinase Elevation and Development of a Risk Prediction Model for Incidence Probability.

Samura M, Hirose N, Kurata T, Takada K, Nagumo F, Koshioka S, Ishii J, Uchida M, Inoue J, Enoki Y, Taguchi K, Higashita R, Kunika N, Tanikawa K, Matsumoto K

Open forum infectious diseases (Oxford University Press (OUP)) 8 ( 12 ) ofab568 2021.12

Research paper (scientific journal), Joint Work, Accepted, ISSN 2328-8957

Abstract

Background

In this study, we investigated the risk factors for daptomycin-associated creatine phosphokinase (CPK) elevation and established a risk score for CPK elevation.

Methods

Patients who received daptomycin at our hospital were classified into the non-elevated or elevated CPK group based on their peak CPK levels during daptomycin therapy. Univariable and multivariable analyses were performed, and a risk score and prediction model for the incidence probability of CPK elevation were calculated based on logistic regression analysis.

Results

The non-elevated and elevated CPK groups included 181 and 17 patients, respectively. Logistic regression analysis revealed that concomitant statin use (odds ratio [OR], 4.45 [95% confidence interval {CI}, 1.40–14.47]; risk score 4), concomitant antihistamine use (OR, 5.66 [95% CI, 1.58–20.75]; risk score 4), and trough concentration (Cmin) between 20 and &lt;30 µg/mL (OR, 14.48 [95% CI, 2.90–87.13]; risk score 5) and ≥30.0 µg/mL (OR, 24.64 [95% CI, 3.21–204.53]; risk score 5) were risk factors for daptomycin-associated CPK elevation. The predicted incidence probabilities of CPK elevation were &lt;10% (low risk), 10%–&lt;25% (moderate risk), and ≥25% (high risk) with total risk scores of ≤4, 5–6, and ≥8, respectively. The risk prediction model exhibited a good fit (area under the receiver operating characteristic curve, 0.85 [95% CI, .74–.95]).

Conclusions

These results suggested that concomitant use of statins with antihistamines and Cmin ≥20 µg/mL were risk factors for daptomycin-associated CPK elevation. Our prediction model might aid in reducing the incidence of daptomycin-associated CPK elevation.

Population Pharmacokinetic Analysis and Dosing Optimization of Prophylactic Fluconazole in Japanese Patients with Hematological Malignancy.

Sakamoto Y, Isono H, Enoki Y, Taguchi K, Miyazaki T, Kunimoto H, Koike H, Hagihara M, Matsumoto K, Nakajima H, Sahashi Y, Matsumoto K

Journal of fungi (Basel, Switzerland) (Journal of Fungi) 7 ( 11 ) 975 - 975 2021.11

Research paper (scientific journal), Joint Work, Accepted

We conducted population pharmacokinetic (PPK) analysis and Monte Carlo simulations to determine the appropriate prophylactic dose of fluconazole to prevent invasive candidiasis in patients with hematological malignancies. Patients receiving chemotherapy or hematopoietic stem cell transplantation at Yokohama City University Hospital between November 2018 and March 2020 were included. Additionally, patients receiving oral fluconazole for prophylaxis were recruited. We set the free area under the curve/minimum inhibitory concentration (MIC) = 50 as the target and determined the largest MIC (breakpoint MIC) that could achieve more than 90% probability of target attainment. The blood fluconazole concentration of 54 patients (119 points) was used for PPK analysis. The optimal model was the one-compartment model with first-order administration and first-order elimination incorporating creatinine clearance (CLcr) as a covariate of clearance and body weight as a covariate of distribution volume. We conducted Monte Carlo simulation with fluconazole at 200 mg/day or 400 mg/day dosing schedules and patient body weight and CLcr ranging from 40 to 70 kg and 40–140 mL/min, respectively. The breakpoint MICs on the first dosing day and at steady state were 0.5–1.0 µg/mL and 1.0–2.0 µg/mL for 200 mg/day and 1.0–2.0 µg/mL and 2.0–4.0 µg/mL for 400 mg/day, respectively. The recommended dose was 400–700 mg/day for the loading dose and 200–400 mg/day for the maintenance dose. Our findings suggest that the optimal prophylactic dose of fluconazole in hematological malignancy patients depends on CLcr and body weight, and a sufficient loading and maintenance dose may be needed to completely prevent invasive candidiasis.

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Long-term pharmaceutical stability of liposome-encapsulated methemoglobin as an antidote for cyanide poisoning.

Suzuki Y, Taguchi K, Kure T, Enoki Y, Otagiri M, Sakai H, Matsumoto K

International journal of pharmaceutics (International Journal of Pharmaceutics) 610 121260 - 121260 2021.11

Research paper (scientific journal), Joint Work, Accepted, ISSN 0378-5173

Liposome-encapsulated methemoglobin (metHb@Lipo) has been developed as a novel antidote for cyanide poisoning. Antidotes for lethal acute poisoning should be capable of being easily stored as ready-to-use formulations without temperature restrictions. Here, we investigated the pharmaceutical stability of the metHb@Lipo suspension after one-year storage as a ready-to-use formulation at 4 °C, room temperature (23–28 °C) and 37 °C. The liposomal integrity of metHb@Lipo was observed after one year of storage at all storage temperatures with no physicochemical change or methemoglobin leakage outside the liposome. Furthermore, the encapsulated methemoglobin remained intact without aggregation, fragmentation, denaturation, or dissociation of heme. Fresh and stored metHb@Lipo were equivalent in their binding affinity against cyanide. Moreover, all one-year stored metHb@Lipo suspensions improved the mortality rates of lethal cyanide poisoning mice comparable to fresh metHb@Lipo suspension. Additionally, all stored metHb@Lipo suspensions preserved high biocompatibility, including blood compatibility and the lack of organ toxicity. In conclusion, the metHb@Lipo suspension was a pharmaceutically stable antidote for cyanide poisoning for at least one year without any temperature restrictions.

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Impact of rifampicin on the pharmacokinetics of clarithromycin and 14-hydroxy clarithromycin in patients with multidrug combination therapy for pulmonary Mycobacterium avium complex infection.

Iketani O, Komeya A, Enoki Y, Taguchi K, Uno S, Uwamino Y, Matsumoto K, Kizu J, Hasegawa N

Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy (Journal of Infection and Chemotherapy) 28 ( 1 ) 61 - 66 2021.10

Research paper (scientific journal), Joint Work, Accepted, ISSN 1341-321X

Introduction: Clarithromycin (CAM), ethambutol (EB), and rifampicin (RFP) combination therapy is used to treat pulmonary Mycobacterium avium complex (MAC) infection; however, serum CAM concentration decreases due to RFP-mediated induction of CYP3A activity. Therefore, we investigated the pharmacokinetics of CAM, 14-hydroxy clarithromycin (14-OH CAM), EB, and RFP in patients receiving this three-drug combination therapy. Methods: CAM monotherapy was started, EB was added 2 weeks later, and RFP was added 2 weeks after that. Serum CAM, 14-OH CAM, EB, and RFP concentrations were measured before and at 2, 4, 6, and 12 or 24 h after administration on days 14, 28, and 42, and pharmacokinetic parameters were calculated. Results: Median area under the curve (AUC) of CAM decreased by 92.1% from 0 to 12 h after concomitant administration of RFP compared with CAM monotherapy [1.7 (interquartile range [IQR], 1.4–1.8) μg·h/mL vs. 21.5 (IQR, 17.7–32.3) μg·h/mL, respectively]. In contrast, median AUC of 14-OH CAM was not significantly different between concomitant administration of RFP [9.1 (IQR, 7.9–10.9) μg·h/mL] and CAM monotherapy [8.2 (IQR, 6.3–9.3) μg·h/mL]. AUCs of CAM and 14-OH CAM did not change in CAM+EB combination therapy. Conclusions: When RFP is combined with CAM in the treatment of pulmonary MAC infection, the blood concentration of CAM significantly decreased and that of the active metabolite 14-OH CAM increased, but not significantly. Our results suggest that combination therapy with CAM and RFP needs to be reconsidered and may require dose modification in the treatment of pulmonary MAC infection.

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Advanced oxidation protein products contribute to chronic kidney disease-induced muscle atrophy by inducing oxidative stress via CD36/NADPH oxidase pathway.

Kato H, Watanabe H, Imafuku T, Arimura N, Fujita I, Noguchi I, Tanaka S, Nakano T, Tokumaru K, Enoki Y, Maeda H, Hino S, Tanaka M, Matsushita K, Fukagawa M, Maruyama T

Journal of cachexia, sarcopenia and muscle (Journal of Cachexia, Sarcopenia and Muscle) 12 ( 6 ) 1832 - 1847 2021.10

Research paper (scientific journal), Joint Work, Accepted, ISSN 2190-5991

Background: Sarcopenia with chronic kidney disease (CKD) progression is associated with life prognosis. Oxidative stress has attracted interest as a trigger for causing CKD-related muscular atrophy. Advanced oxidation protein products (AOPPs), a uraemic toxin, are known to increase oxidative stress. However, the role of AOPPs on CKD-induced muscle atrophy remains unclear. Methods: In a retrospective case–control clinical study, we evaluated the relationship between serum AOPPs levels and muscle strength in haemodialysis patients with sarcopenia (n = 26, mean age ± SEM: 78.5 ± 1.4 years for male patients; n = 22, mean age ± SEM: 79.1 ± 1.5 for female patients), pre-sarcopenia (n = 12, mean age ± SEM: 73.8 ± 2.0 years for male patients; n = 4, mean age ± SEM: 74.3 ± 4.1 for female patients) or without sarcopenia (n = 12, mean age ± SEM: 71.3 ± 1.6 years for male patients; n = 7, mean age ± SEM: 77.7 ± 1.6 for female). The molecular mechanism responsible for the AOPPs-induced muscle atrophy was investigated by using 5/6-nephrectomized CKD mice, AOPPs-overloaded mice, and C2C12 mouse myoblast cells. Results: The haemodialysis patients with sarcopenia showed higher serum AOPPs levels as compared with the patients without sarcopenia. The serum AOPPs levels showed a negative correlation with grip strength (P < 0.01 for male patients, P < 0.01 for female patients) and skeletal muscle index (P < 0.01 for male patients). Serum AOPPs levels showed a positive correlation with cysteinylated albumin (Cys-albumin), a marker of oxidative stress (r2 = 0.398, P < 0.01). In the gastrocnemius of CKD mice, muscle AOPPs levels were also increased, and it showed a positive correlation with atrogin-1 (r2 = 0.538, P < 0.01) and myostatin expression (r2 = 0.421, P < 0.05), but a negative correlation with PGC-1α expression (r2 = 0.405, P < 0.05). Using C2C12 cells, AOPPs increased atrogin-1 and myostatin expression through the production of reactive oxygen species via CD36/NADPH oxidase pathway, and decreased myotube formation. AOPPs also induced mitochondrial dysfunction. In the AOPPs-overloaded mice showed that decreasing running time and hanging time accompanied by increasing AOPPs levels and decreasing cross-sectional area in gastrocnemius. Conclusions: Advanced oxidation protein products contribute to CKD-induced sarcopenia, suggesting that AOPPs or its downstream signalling pathway could be a therapeutic target for the treatment of CKD-induced sarcopenia. Serum AOPPs or Cys-albumin levels could be a new diagnostic marker for sarcopenia in CKD.

Asymmetric Total Syntheses of Both Enantiomers of Plymuthipyranone B and Its Unnatural Analogues: Evaluation of anti-MRSA Activity and Its Chiral Discrimination.

Moriyama M, Liu X, Enoki Y, Matsumoto K, Tanabe Y

Pharmaceuticals (Basel, Switzerland) (Pharmaceuticals) 14 ( 9 ) 938 - 938 2021.09

Research paper (scientific journal), Joint Work, Accepted, ISSN 1424-8247

Chiral total syntheses of both enantiomers of the anti-MRSA active plymuthipyranone B and all of the both enantiomers of three unnatural and synthetic analogues were performed. These two pairs of four chiral compounds are composed of the same 3-acyl-5,6-dihydro-2H-pyran-2-one structure. The starting synthetic step utilized a privileged asymmetric Mukaiyama aldol addition using Ti(OiPr)4/(S)-BINOL or Ti(OiPr)4/(R)-BINOL catalysis to afford the corresponding (R)-and (S)-δ-hydroxy-β-ketoesters, respectively, with highly enantiomeric excess (> 98%). Conventional lactone formation and successive EDCI-mediated C-acylation produced the desired products, (R)-and (S)-plymuthipyranones B and three (R)-and (S)-synthetic analogues, with an overall yield of 42–56% with a highly enantiomeric excess (95–99%). A bioassay of the anti-MRSA activity against ATCC 43300 and 33591 revealed that (i) the MICs of the synthetic analogues against ATCC 43300 and ATCC 33591 were between 2 and 16 and 4 and 16 μg/mL, respectively, and those of vancomycin (reference) were 1 μg/mL. (ii) The natural (S)-plymuthipyranone B exhibited significantly higher activity than the unnatural (R)-antipode against both AACCs. (iii) The natural (R)-plymuthipyra-none B and (R)-undecyl synthetic analogue at the C6 position exhibited the highest activity. The present work is the first investigation of the SAR between chiral R and S forms of this chemical class.

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Different intra-cerebrospinal distribution of linezolid in patients with inflammatory meningitis.

Ichinose N, Yoshikawa G, Fukao E, Ichisawa M, Takahata T, Enoki Y, Taguchi K, Oda T, Tsutsumi K, Matsumoto K

International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases (International Journal of Infectious Diseases) 110 382 - 384 2021.08

Research paper (scientific journal), Joint Work, Accepted, ISSN 1201-9712

Linezolid has excellent antibiotic activity against gram-positive organisms and is expected to be an alternative to vancomycin for the treatment of bacterial meningitis. Accumulated evidence has shown the superior pharmacokinetic characteristics of linezolid to vancomycin, such as cerebrospinal fluid penetration. However, in the treatment of meningitis, pharmacokinetic information regarding the intra-cerebrospinal distribution of linezolid and the effects of drainage on the linezolid concentration in the cerebrospinal fluid are unclear. This report describes two patient cases, in which the linezolid concentrations in the cerebrospinal fluid were in the following order: subarachnoid space (cisternal drainage and lumbar puncture) ≥ third ventricle > lateral ventricle. In addition, the linezolid concentration in the cerebrospinal fluid, collected via lumbar puncture, tended to increase after removal of the drainage. This report is novel in presenting two cases of meningitis that showed different intra-cerebrospinal distribution of linezolid in various parts of the central nervous system and an increased linezolid concentration in the cerebrospinal fluid after removal of the drainage.

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Augmented clearance of nivolumab is associated with renal functions in chronic renal disease model rats.

Taguchi K, Hayashi Y, Ohuchi M, Yamada H, Yagishita S, Enoki Y, Matsumoto K, Hamada A

Drug metabolism and disposition: the biological fate of chemicals (Drug metabolism and disposition: the biological fate of chemicals) 50 ( 6 ) 822 - 826 2021.08

Research paper (scientific journal), Joint Work, Accepted, ISSN 0090-9556

The clinically approved dose of nivolumab is 240 mg Q2W. However, previous studies have shown that baseline nivolumab clearance (CL) is associated with treatment outcomes in patients with solid cancers, thus motivating researchers to identify prognostic factors and indices influencing nivolumab CL. This study used chronic kidney disease model rats to investigate whether chronic renal impairment affected nivolumab CL and explored the surrogate markers associated with nivolumab CL. We observed that the total CL for nivolumab (CLtot) was approximately 1.42-times higher in chronic kidney disease model rats than that in sham rats with an increased urinary excretion. Additionally, CLtot showed positive correlation with renal CL for nivolumab (CLR), but not with extrarenal CL. Furthermore, the baseline levels of creatinine, blood urea nitrogen, creatinine CL, and urinary albumin/creatine ratio based on laboratory data were also significantly correlated with CLR Our findings suggest that nivolumab CL increases as renal function deteriorates due to an increased excretion of nivolumab in the urine; additionally, laboratory data reflecting renal function may be a feasible index to qualitatively estimate nivolumab CL prior to nivolumab treatment under conditions of renal impairment. Significance Statement We demonstrated that nivolumab was rapidly eliminated from the circulation in chronic kidney disease model rats compared to sham rats with an increased urinary nivolumab excretion. Moreover, nivolumab clearance was significantly correlated with the baseline levels of certain laboratory parameters reflecting renal functions. These results indicate the potential applicability of baseline renal function as a prognostic index to qualitatively estimate nivolumab clearance prior to nivolumab treatment under conditions with renal impairment.

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Species Distribution of Candidemia and Their Susceptibility in a Single Japanese University Hospital: Prior Micafungin Use Affects the Appearance of Candida parapsilosis and Elevation of Micafungin MICs in Non-parapsilosis Candida Species.

Sakamoto Y, Kawabe K, Suzuki T, Sano K, Ide K, Nishigaki T, Enoki Y, Taguchi K, Koike H, Kato H, Sahashi Y, Matsumoto K

Journal of fungi (Basel, Switzerland) (Journal of Fungi) 7 ( 8 ) 596 2021.07

Research paper (scientific journal), Joint Work, Accepted

Introduction: Micafungin is a recommended echinocandin antifungal agent for can-didemia treatment and prophylaxis. However, overuse of echinocandin antifungals may cause re-sistance. There is currently no information available regarding the low susceptibility associated with using micafungin. This study investigated the effect of micafungin use on changes in the detected Candida species and low susceptibility. Methods: We conducted a retrospective survey and included records of Candida spp. detected in blood cultures from January 2010 to December 2018 in our hospital. Survey items included clinical outcomes at 30 days after positive cultures, patient char-acteristics, and drug prescription status. Patient background information included gender, previous hospitalization, stay in the intensive care unit, comorbidities, and history of surgery (within 90 days before candidemia onset) and drug exposure. Species detected and their minimum inhibitory concentrations (MICs) and amount of antifungal prescriptions by department were investigated. Risk factors for detecting C. parapsilosis and for low susceptibility to micafungin were evaluated using multivariate analysis. Results: A total of 153 Candida clinical blood isolates were collected and C. albicans was the most prevalent species, followed by C. parapsilosis and C. glabrata. In the analysis by department, antifungal use and non‐albicans Candida species were most frequently detected in the hematology department. Multivariate analysis showed that prior micafungin use increased the risk of C. parapsilosis (odds ratio (OR) 4.22; 95% confidence interval (CI) 1.39–12.79; p = 0.011). MIC90 of micafungin on C. glabrata and C. parapsilosis was 1.0 μg/mL. Prior micafungin use was clarified as a risk factor resulting in MIC > 0.06 μg/mL for micafungin in non‐parapsilosis Candida species (OR 13.2; 95% CI 3.23–54.2; p < 0.01). Conclusion: Prior micafungin use increased the risk of C. parapsilosis and the MIC > 0.06 μg/mL of micafungin in non‐parapsilosis Candida species. Since there are only a few antifungal options, further antifungal stewardship considering azole antifungal agents use is re-quired.

Liposome-encapsulated methemoglobin as an antidote against cyanide poisoning.

Suzuki Y, Taguchi K, Kure T, Sakai H, Enoki Y, Otagiri M, Matsumoto K

Journal of controlled release : official journal of the Controlled Release Society (Journal of Controlled Release) 337 59 - 70 2021.07

Research paper (scientific journal), Joint Work, Accepted, ISSN 0168-3659

Cyanide induces acute lethal poisoning resulting from inhibition of cytochrome c oxidase located in the complex IV (Complex IV) of mitochondria. However, current therapies for cyanide poisoning using hydroxocobalamin and nitrous acid compounds remain a clinical issue. Here, we show that liposome-encapsulated methemoglobin (metHb@Lipo), nanosized biomimetic red blood cells, replicate the antidotal mechanism of nitrous acid compounds against cyanide poisoning, achieving superior efficacy and fast action with no adverse effects. The structure of metHb@Lipo, which consists of concentrated methemoglobin in its aqueous core and a lipid membrane resembling the red blood cell membrane, provides favorable characteristics as a cyanide antidote, such as binding properties and membrane permeability. Upon cyanide exposure, metHb@Lipo maintained the mitochondrial function in PC12 cells, resulting in a cell viability comparable to treatment with nitrous acid compounds. In a mouse model of cyanide poisoning, metHb@Lipo treatment dramatically improved mortality with a rapid recovery from the symptoms of cyanide poisoning compared to treatment with nitrous acid compounds. Furthermore, metHb@Lipo also possesses satisfactory pharmacokinetic properties without long-term bioaccumulation and toxicity. Our findings showed a novel concept to develop drugs for cyanide poisoning and provide a promising possibility for biomimetic red blood cell preparations for pharmaceutical applications.

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セルフメディケーション税制に対する新人薬局薬剤師の認知・見解実態把握調査

田口和明, 榎木裕紀, 有賀聡美, 榊原幹夫, 堀里子, 山浦克典, 松元一明

医療薬学 ((一社)日本医療薬学会) 47 ( 7 ) 358 - 363 2021.07

Research paper (scientific journal), Joint Work, Accepted, ISSN 1346-342X

ドラッグストアまたはドラッグストア併設の保険薬局に勤務し、在学中にセルフメディケーション税制(以下、本税制)が施行されていた薬剤師を対象に、本税制に関する認知・見解実態把握調査(アンケート)を実施した。調査対象者は、男性138名(44.5%)、女性172名(55.5%)の合計310名であった。本税制の認知度と理解度について調査したところ、284名(91.6%)の調査対象者が「よく知っている(説明できる)」または「聞いたことはあるが、内容はよく知らない」と回答し、理解度に差はあるものの、ほとんどの調査対象者が本税制について見聞があった。これらの調査対象者は、主に「テレビ」、「雑誌本」、「インターネット」などのメディアを通して本税制に関する情報を得ていた。また、教育現場や職場で本税制について知った調査対象者も多かった。調査対象者の97名(31.3%)が本税制に関する講義を受講したと回答した。本税制の認知度を集計した結果、大学で本税制の講義を受けたことのあると回答した調査対象者において、「よく知っている(説明できる)」と回答した割合が顕著に高かった。今後、薬剤師として働くうえで、多くの調査対象者(86.4%)が本税制の知識が必要だと感じており、半数の調査対象者が本税制に関する情報を収集するうえで携帯アプリを活用したいと回答した。

Retrospective study of the efficacy and safety of metronidazole and vancomycin for Clostridioides difficile infection.

Misawa K, Iketani O, Enoki Y, Taguchi K, Uno S, Uwamino Y, Hasegawa N, Matsumoto K

Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy (Journal of Infection and Chemotherapy) 27 ( 10 ) 1407 - 1412 2021.05

Research paper (scientific journal), Joint Work, Accepted, ISSN 1341-321X

Introduction: According to the Japanese guidelines for the management of Clostridioides difficile infection (CDI), the first choice is metronidazole (MNZ) for non-severe cases and vancomycin (VCM) for severe cases. However, the appropriateness of this first choice in Japanese patients is unclear. We therefore evaluated the appropriateness of the CDI management guidelines and the incidence of adverse drug reactions. Methods: The electronic chart data at Keio University Hospital between January 2012 and June 2019 were retrospectively reviewed. The response rate, the relapse rate, and the adverse reaction rate of treatment for CDI using MNZ or VCM were investigated according to the disease severity. Factorial analysis associated with the response, relapse, and adverse reaction was also performed. Results: In the 352 patients surveyed, no significant difference was observed in the response rate between MNZ and VCM regardless of the severity of CDI. The presence of cancer was a factor related to the persistence of diarrheal symptoms and older age was a risk factor for relapse. MNZ induced nausea significantly more frequently than VCM, and young age and female sex were risk factors for nausea. Conclusion: As no significant difference was observed in the response rate of CDI between MNZ and VCM, the Japanese CDI management guidelines, which recommend MNZ as the first choice, were demonstrated to be appropriate. Attention to nausea was also suggested to be necessary when administering MNZ to young females.

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Population Pharmacokinetic Analysis and Dosing Optimization Based on Unbound Daptomycin Concentration and Cystatin C in Nonobese Elderly Patients with Hypoalbuminemia and Chronic Kidney Disease.

Samura M, Takada K, Yamamoto R, Ito H, Nagumo F, Uchida M, Kurata T, Koshioka S, Enoki Y, Taguchi K, Higashita R, Kunika N, Tanikawa K, Matsumoto K

Pharmaceutical research (Pharmaceutical Research) 38 ( 6 ) 1041 - 1055 2021.05

Research paper (scientific journal), Joint Work, Accepted, ISSN 0724-8741

Purpose: This study evaluated the population pharmacokinetics of daptomycin in nonobese elderly patients with hypoalbuminemia and chronic kidney disease (CKD) using the glomerular filtration rate estimated from cystatin C (eGFRcys) and estimated its optimal dose. Methods: We performed population pharmacokinetic analysis of the unbound concentrations of daptomycin. The probability of target attainment of 90% for achieving an area under the concentration–time curve of unbound daptomycin at steady state/ minimum inhibitory concentration ratio of ≥66.6 was stochastically simulated. Results: In the population pharmacokinetic analysis of 25 patients aged ≥65 years, the two-compartment model using eGFRcys and age as covariates of clearance in central compartment of unbound daptomycin were optimal. The unbound fraction rate (fu) was 0.05–0.14. According to the Monte Carlo simulation, the optimal doses for patients with eGFRcys of 20–60 mL/min and aged 65–95 years were calculated as 200–500 mg q24h. Conclusion: These results suggest that establishing the dose using total concentrations may result in under- or overestimation caused by alterations in fu. The optimal dose for nonobese elderly patients with hypoalbuminemia and CKD depends on eGFRcys and age, and a standard dose may be insufficient for some patients.

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Surveying health seminar participants on the self-medication tax deduction system and extracting challenges associated with tax reform

Kazuaki Taguchi, Yuki Enoki, Satomi Aruga, Mikio Sakakibara, Satoko Hori, Katsunori Yamaura, Kazuaki Matsumoto

Japanese Journal of Pharmaceutical Health Care and Sciences (Japanese Scoiety of Pharmaceutical Health Care and Science) 47 ( 5 ) 256 - 263 2021.05

Research paper (scientific journal), Joint Work, Accepted, ISSN 1346-342X

健康セミナー参加者247名を対象に、セルフメディケーション税制に対する認知、理解度や関心などの実情に関するアンケートを実施し、本税制を取り巻く国民の実状と本税制の課題を明らかにすることを目的とした。調査の結果、過半数の調査対象者がドラッグストアを1ヵ月間に複数回利用しており、ドラッグストアを頻繁に利用している現状が示された。しかし、1年間のOTC医薬品の合計購入額が1万2千円以上10万円未満の調査対象者は11.8%(29人)と少なく、1年間のOTC医薬品の合計購入額が10万円以上の調査対象者はいなかった。セルフメディケーション税制の認知度について調査したところ、理解度に差はあるものの60%以上の調査対象者が本税制を認知していた。さらに、OTC医薬品の年間合計購入金額別に認知度を集計した。その結果、合計購入金額が1万2千円未満の調査対象者と合計購入金額が1万2千円以上の調査対象者で認知度は変わらなかったものの、合計購入金額が1万2千円以上の調査対象者のほうがセルフメディケーション税制について「知っている」と回答した割合が多かった。しかし、認知度に比べて申告件数は著しく少なかった。セルフメディケーション税制については、約50%(43人)が興味を示すとともに申告要件が揃っていれば控除を受けたいと回答した。

The monitoring of vancomycin: a systematic review and meta-analyses of area under the concentration-time curve-guided dosing and trough-guided dosing.

Tsutsuura M, Moriyama H, Kojima N, Mizukami Y, Tashiro S, Osa S, Enoki Y, Taguchi K, Oda K, Fujii S, Takahashi Y, Hamada Y, Kimura T, Takesue Y, Matsumoto K

BMC infectious diseases (BMC Infectious Diseases) 21 ( 1 ) 153 2021.02

Research paper (scientific journal), Joint Work, Accepted

Background: This systematic review and meta-analysis explored the relationship between vancomycin (VCM) monitoring strategies and VCM effectiveness and safety. Methods: We conducted our analysis using the MEDLINE, Web of Sciences, and Cochrane Register of Controlled Trials electronic databases searched on August 9, 2020. We calculated odds ratios (ORs) and 95% confidence intervals (CIs). Results: Adult patients with methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia with VCM trough concentrations ≥15 μg/mL had significantly lower treatment failure rates (OR 0.63, 95% CI 0.47–0.85). The incidence of acute kidney injury (AKI) increased with increased trough concentrations and was significantly higher for trough concentrations ≥20 μg/mL compared to those at 15–20 μg/mL (OR 2.39, 95% CI 1.78–3.20). Analysis of the target area under the curve/minimum inhibitory concentration ratios (AUC/MIC) showed significantly lower treatment failure rates for high AUC/MIC (cut-off 400 ± 15%) (OR 0.28, 95% CI 0.18–0.45). The safety analysis revealed that high AUC value (cut-off 600 ± 15%) significantly increased the risk of AKI (OR 2.10, 95% CI 1.13–3.89). Our meta-analysis of differences in monitoring strategies included four studies. The incidence of AKI tended to be lower in AUC-guided monitoring than in trough-guided monitoring (OR 0.54, 95% CI 0.28–1.01); however, it was not significant in the analysis of mortality. Conclusions: We identified VCM trough concentrations and AUC values that correlated with effectiveness and safety. Furthermore, compared to trough-guided monitoring, AUC-guided monitoring showed potential for decreasing nephrotoxicity.

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The optimal trough-guided monitoring of vancomycin in children: Systematic review and meta-analyses.

Moriyama H, Tsutsuura M, Kojima N, Mizukami Y, Tashiro S, Osa S, Enoki Y, Taguchi K, Oda K, Fujii S, Takahashi Y, Hamada Y, Kimura T, Takesue Y, Matsumoto K

Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy (Journal of Infection and Chemotherapy) 27 ( 5 ) 781 - 785 2021.02

Research paper (scientific journal), Joint Work, Accepted, ISSN 1341-321X

We carried out a systematic review and meta-analysis exploring the relationship between vancomycin (VCM) trough concentrations and its effectiveness and nephrotoxicity in pediatric patients. We conducted our analysis using MEDLINE, Web of Sciences, and Cochrane Register of Controlled Trials as electronic databases (June 29, 2019). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. We identified 16 studies that were eligible for the meta-analysis. A total of 351 and 3,266 patients were included in the analysis for effectiveness and nephrotoxicity, respectively. Pediatric MRSA infection patients with VCM trough concentrations ≥ 10 μg/mL had significantly lower treatment failure rates (OR 0.54, 95% CI 0.30–0.96). The incidence of nephrotoxicity was significantly higher in trough concentrations ≥ 15 μg/mL than when they were < 15 μg/mL (OR 3.02, 95% CI 2.08–4.38). We identified the optimal VCM trough concentrations associated with effectiveness and nephrotoxicity in pediatric patients with MRSA infection. Further prospective studies are needed to find optimal dosing and monitoring strategy on VCM in pediatric population.

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Pharmacokinetics/Pharmacodynamics Evaluation of Flomoxef against Extended-Spectrum Beta-Lactamase-Producing Escherichia coli In Vitro and In Vivo in a Murine Thigh Infection Model.

Tashiro S, Hayashi M, Takemura W, Igarashi Y, Liu X, Mizukami Y, Kojima N, Enoki Y, Taguchi K, Yokoyama Y, Nakamura T, Matsumoto K

Pharmaceutical research (Pharmaceutical Research) 38 ( 1 ) 27 - 35 2021.01

Research paper (scientific journal), Joint Work, Accepted, ISSN 0724-8741

Purpose: Although flomoxef (FMOX) has attracted substantial attention as an antibiotic against extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-producing E. coli), the pharmacokinetics/pharmacodynamics (PK/PD) characteristics of FMOX against ESBL-producing E. coli is unclear. The aim of this study was to determine the PK/PD index of FMOX against ESBL-producing E. coli. Methods: In vitro time-kill curve studies and in vivo PK/PD experiments were carried out. Results: Time–kill curves exhibited a unique bactericidal activity: time-dependent activity at low concentrations and concentration-dependent activity at high concentrations. In neutropenic murine thigh infection experiments, the antibacterial activity of FMOX correlated with the time that the free drug concentration remaining above the minimum inhibitory concentration (MIC) (fT>MIC) and the ratio of the area under the free drug concentration–time curve for a 24 h period to the MIC (fAUC /MIC). However, the burden of ESBL producing E. coli significantly reduced when the time intervals for administration were shorter among three dosage regimens with same magnitude of fAUC /MIC, indicating that fT>MIC is significant PK/PD index. The target value of fT>MIC for 1 log kill reduction was 35.1%. Conclusions: fT>MIC is the most significant PK/PD index of FMOX against ESBL-producing E. coli and its target value is ≥ 40%. 24 24 10

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Dosing Optimization of Ampicillin-Sulbactam Based on Cystatin C in Elderly Patients with Pneumonia.

Matsubara K, Matsumoto K, Yokoyama Y, Watanabe E, Enoki Y, Shigemi A, Ikawa K, Terazono H, Morikawa N, Ohshige T, Takeda Y

Biological & pharmaceutical bulletin (Biological and Pharmaceutical Bulletin) 44 ( 5 ) 732 - 736 2021

Research paper (scientific journal), Joint Work, Accepted, ISSN 0918-6158

Ampicillin-sulbactam is a first-line therapy for pneumonia and is mainly excreted by the kidney. It is important to optimize the dose and dosing interval of ampicillin-sulbactam because in patients with decreased renal function and low skeletal muscle mass, such as the elderly, excess drug may burden renal function. In this study, we evaluated indices of renal function and optimized the dose and dosing interval of ampicillin-sulbactam based on pharmacokinetics (PK) and pharmacodynamics theory in elderly patients. The serum concentrations of ampicillin and sulbactam were measured by HPLC, and PK parameters were calculated. Correlations between the clearance of ampicillin or sulbactam and renal function were evaluated, and dosing optimization was calculated based on PK parameters. The PK parameters of ampicillin were CL=6.5±4.0L/h, Vd=19.3±0.2L, Ke=0.4±0.2, and t1/2=2.7±1.6h. The most correlated renal function index was estimated glomerular filtration rate (eGFRcys-c) calculated by serum cystatin-c (r=0.7374, correlation formula; CL of ampicillin=0.1937×eGFRcys-c-0.6726). Based on this formula, we calculated the clearance of ampicillin and developed dosing regimens for the elderly. Serum cystatin-c concentration is an ideal index to optimize ampicillin-sulbactam antimicrobial therapy in elderly patients with pneumonia.

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Rational dosage regimens for cephalothin and cefazolin using pharmacokinetics and pharmacodynamics analysis in healthy horses.

Kuroda T, Minamijima Y, Niwa H, Tamura N, Mita H, Fukuda K, Kaimachi M, Suzuki Y, Enoki Y, Taguchi K, Matsumoto K, Toutain PL, Bousquet-Melou A, Kasashima Y

Equine veterinary journal (Equine Veterinary Journal) 2020.12

Research paper (scientific journal), Joint Work, Accepted, ISSN 0425-1644

Background: First-generation cephalosporins have good activity against gram-positive bacteria and are extensively used in horses. There are few reports of pharmacokinetics and pharmacodynamics (PK/PD) analysis of cephalosporins in horses. Objective: To optimise the dosages of the two first-generation cephalosporins cephalothin (CET) and cefazolin (CEZ) in horses using PK/PD concepts. Study design: Experimental study with single administration. Methods: Drug plasma concentrations following a single intravenous (i.v.) administration of 22 mg/kg bodyweight (bwt) CET in 12 horses and of 10 mg/kg bwt CEZ in six horses were measured using LC-MS/MS. Data were modelled using a nonlinear mixed effect modelling followed by Monte Carlo simulations. Minimum inhibitory concentrations (MICs) against Streptococcus zooepidemicus and Staphylococcus aureus isolated from horses were determined by the microbroth dilution method. Results: The percentages of CET and CEZ binding to serum proteins were 19.9% ± 8.4% and 15.2% ± 8.5% respectively. For both CET and CEZ, the MIC against S. zooepidemicus was 0.12 mg/L and against S. aureus was 0.5 mg/L. For CET, to achieve a probability of target attainment (PTA) of 90% for a PK/PD target of a free serum plasma concentration exceeding the MIC for 40% of the dosing interval, an empirical CET dosage regimen of 22 mg/kg bwt q8h and 22 mg/kg bwt q4h i.v. administration were required for S. zooepidemicus and S. aureus respectively. For CEZ, the corresponding dosage regimens were 10 mg/kg bwt q12h and 10 mg/kg bwt q8h. Main limitations: Small sample size only in healthy horses. Conclusions: For CET, more frequent administration than that currently recommended (22 mg/kg bwt q6–12h) is required to empirically control S. aureus infection in horses. For CEZ, less frequent administration compared to the dosage regimen currently proposed (10–22 mg/kg bwt q6h) could control S. zooepidemicus and S. aureus infections in horses. 90 90

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Remdesivir for the treatment of coronavirus COVID-19: A meta-analysis of randomised controlled trials.

Enoki Y, Igarashi Y, Watabe Y, Honma K, Suzuki Y, Hayashi Y, Hiraoka K, Taguchi K, Matsumoto K

Journal of global antimicrobial resistance (Journal of Global Antimicrobial Resistance) 24 81 - 82 2020.12

Research paper (scientific journal), Joint Work, Accepted, ISSN 2213-7165

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Use of an alternative signature peptide during development of a LC-MS/MS assay of plasma nivolumab levels applicable for multiple species.

Ohuchi M, Yagishita S, Taguchi K, Goto Y, Fukahori M, Enoki Y, Shimada T, Yamaguchi M, Matsumoto K, Hamada A

Journal of chromatography. B, Analytical technologies in the biomedical and life sciences (Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences) 1162 122489 2020.12

Research paper (scientific journal), Joint Work, Accepted, ISSN 1570-0232

Recently, immune checkpoint inhibitors, including anti-programmed cell death protein 1 (PD-1) antibodies, have dramatically changed treatment strategies for several cancers. In pharmacokinetic/pharmacodynamic studies, experiments using a variety of animal species are assumed. We have identified optimal multiple reaction monitoring transitions for signature candidate peptides of nivolumab in human, mouse, and rat plasma and developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify nivolumab (an anti-PD-1 antibody) using trastuzumab as the internal standard. Calibration curves were linear in the range of 1–200 µg/mL. The intra- and inter-day precision and accuracy in human plasma fulfilled Food and Drug Administration guideline criteria for bioanalytical validation. There was no need to change the measurement method in mouse plasma. On the other hand, in rat plasma, an interference peak was observed at a retention time similar to that of the surrogate peptide ASGITFSNSGMHWVR (550.75 > 661.50) employed in human and mouse plasma. Therefore, we confirmed that ASQSVSSYLAWYQQKPGQAPR (785.0 > 940.2) can be used as an alternate nivolumab surrogate peptide in rat plasma at the same concentration range as used in human and mouse plasma. Using our method, the concentration range and a gradual increase in trough value were confirmed in clinical samples from two antibody-treated patients, including one with gastric cancer and one with non-small-cell lung cancer. The time course and blood concentration transition also were evaluated in nivolumab administration experiments in mouse and rat. The present study showed that the selection of the optimal peptide is essential for accurate LC-MS/MS measurement of nivolumab concentration in human, mouse, and rat plasma. The method developed here is expected to be of use in non-clinical and clinical pharmacokinetic studies.

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Pharmacokinetic/pharmacodynamic evaluation of teicoplanin against Staphylococcus aureus in murine thigh infection model.

Watanabe E, Matsumoto K, Ikawa K, Yokoyama Y, Shigemi A, Enoki Y, Umezaki Y, Nakamura K, Ueno K, Terazono H, Morikawa N, Takeda Y

Journal of global antimicrobial resistance (Journal of Global Antimicrobial Resistance) 24 83 - 87 2020.12

Research paper (scientific journal), Joint Work, Accepted, ISSN 2213-7165

Objectives: Pharmacokinetic/pharmacodynamic (PK/PD) analysis using murine infection models is a well-established methodology for optimising antimicrobial therapy. Therefore, we investigated the PK/PD indices of teicoplanin againstStaphylococcus aureus using a murine thigh infection model. Methods: Mice were rendered neutropenic by administration of a two-step dosing of cyclophosphamide. Then, isolates of methicillin-susceptibleS. aureus (MSSA) or methicillin-resistant S. aureus (MRSA) were inoculated into the thighs of neutropenic mice. PK/PD analyses were performed by non-linear least-squared regression using the MULTI program. Results: Target values offC /MIC (r = 0.94) of teicoplanin for static effect and 1 log kill against MSSA were 4.44 and 15.44, respectively. Target values of fAUC /MIC (r = 0.92) of teicoplanin for static effect and 1 log kill against MSSA were 30.4 and 70.56, respectively. Target values of fC /MIC (r = 0.91) of teicoplanin for static effect and 1 log kill against MRSA were 8.92 and 14.16, respectively. Target values of fAUC /MIC (r = 0.92) of teicoplanin for static effect and 1 log kill against MRSA were 54.8 and 76.4, respectively. Conclusion: These results suggest thatfC /MIC and fAUC /MIC are useful PK/PD indices of teicoplanin against MSSA and MRSA. max 10 24 10 max 10 24 10 max 24 2 2 2 2

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Stability of antimicrobial agents in an elastomeric infusion pump used for outpatient parenteral antimicrobial therapy.

Akahane M, Enoki Y, Saiki R, Hayashi Y, Hiraoka K, Honma K, Itagaki M, Gotoda M, Shinoda K, Hanyu S, Hamamura Y, Miyajima T, Ito C, Taguchi K, Uno S, Uwamino Y, Iketani O, Hasegawa N, Matsumoto K

International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases (International Journal of Infectious Diseases) 103 464 - 468 2020.11

Research paper (scientific journal), Joint Work, Accepted, ISSN 1201-9712

Objectives: The long-term stability of antimicrobials dissolved in infusion solution is necessary to establish and spread the outpatient parenteral antimicrobial therapy (OPAT). In this study, we evaluated the stability of antimicrobial agents dissolved in infusion solutions. Methods: The antimicrobial agents were dissolved in infusion solutions and kept at 25 °C and 31.1 °C for 24 h or 4 °C for 10 days in a polypropylene tube or an elastomeric infusion pump. The stability was measured by high-performance liquid chromatography. Results and conclusion: The residual ratio of cefazolin (CEZ), cefmetazole (CMZ), piperacillin (PIPC), and tazobactam (TAZ) at 31.1 °C for 24 h was as follows: 95.7 ± 3.0%, 94.8 ± 0.9%, 102.6 ± 1.8%, and 103.9 ± 3.6% in saline, respectively; 94.7 ± 3.0%, 94.3 ± 1.5%, 106.1 ± 3.0%, and 107.3 ± 2.4% in 5% dextrose solution, respectively. The residual ratio of these antimicrobials at 4 °C for 10 days was maintained above 90% in both saline and 5% dextrose solution. The residual ratio of all the above antimicrobials in an elastomeric infusion pump at 31.1 °C for 24 h was equivalent to that in the polypropylene tube. On the other hand, doripenem and meropenem were not stable in any infusion solution at 31.1 °C. CEZ, CMZ, and PIPC/TAZ dissolved in saline or 5% dextrose solution can be used in OPAT with continuous infusion pumps.

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Multivalent cation and polycation polymer preparations influence pharmacokinetics of dolutegravir via chelation-type drug interactions.

Enoki Y, Kishi N, Sakamoto K, Uchiyama E, Hayashi Y, Suzuki N, Ito M, Taguchi K, Yokoyama Y, Kizu J, Matsumoto K

Drug metabolism and pharmacokinetics (Drug Metabolism and Pharmacokinetics) 37 100371 2020.11

Research paper (scientific journal), Joint Work, Accepted, ISSN 1347-4367

Dolutegravir (DTG) is an integrase inhibitor, whose gastrointestinal absorption is impaired by the formation of chelates with multivalent metal cation preparations. However, little is known regarding the interactions of DTG with preparations containing other multivalent metal cations or with polycation polymer preparations. This study examined how the pharmacokinetics of DTG are affected by co-administration with Al(OH) , LaCO , and the polycation polymers bixalomer (Bxl) and sevelamer (Svl). Prior to oral administration of DTG (5 mg/kg), rats were orally administered Al(OH) (150 or 300 mg/kg), LaCO (50 or 75 mg/kg), Bxl (250 or 500 mg/kg), or Svl (300 or 600 mg/kg). Serum concentrations of DTG were then measured over the next 24 h. Compared to the administration of DTG alone, its co-administration with Al(OH) , LaCO , Bxl, and Svl led to reduced serum concentration of DTG, and consequently, a significantly reduced area under the curve. These comparisons also revealed a considerable reduction in the maximum concentration, suggesting that the interactions of these agents with DTG in the intestinal tract inhibit absorption of DTG. The above results demonstrate that Al(OH) , LaCO , Bxl, and Svl affect the pharmacokinetics of DTG and indicate the need for caution when combining any of the above preparations with DTG. 3 3 3 3 3 3 3 3

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Azoles versus conventional amphotericin B for the treatment of candidemia: A meta-analysis of randomized controlled trials.

Osa S, Tashiro S, Igarashi Y, Watabe Y, Liu X, Enoki Y, Taguchi K, Mayumi T, Miyazaki Y, Takesue Y, Matsumoto K

Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy (Journal of Infection and Chemotherapy) 26 ( 11 ) 1232 - 1236 2020.08

Research paper (scientific journal), Joint Work, Accepted, ISSN 1341-321X

© 2020 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases Because exclusive use of echinocandins can induce the drug-resistant strains, appropriate use of azoles and polyenes is still necessary in the treatment of candidemia. In this study, we conducted a meta-analysis of randomized controlled trials regarding the efficacy and safety of azole and polyene antifungals in the treatment of candidemia. MEDLINE and the Cochrane Register of Controlled Trials were used as reference databases, and papers published up to June 10, 2019 were searched. The search results were carefully scrutinized, duplicate references were removed, and the study was ultimately carried out using three reports. Among azole antifungals, fluconazole and voriconazole were extracted, however; only conventional amphotericin B (AMPH-B) was extracted among polyene antifungals. Treatment successes with the use of azoles and AMPH-B were compared, and findings showed that AMPH-B was significantly superior (RR = 0.90, 95% CI 0.82–1.00, p = 0.04). However, there was no significant difference in mortality (RR = 0.87, 95% CI 0.72–1.07, p = 0.19). Analysis of adverse events showed that renal disorders were significantly less common with azoles than with AMPH-B (RR = 0.26, 95% CI 0.10–0.68, p = 0.006). In conclusion, AMPH-B were superior to azoles in terms of efficacy, but had a risk of causing renal disorders.

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Indoxyl Sulfate Contributes to Adipose Tissue Inflammation through the Activation of NADPH Oxidase.

Tanaka S, Watanabe H, Nakano T, Imafuku T, Kato H, Tokumaru K, Arimura N, Enoki Y, Maeda H, Tanaka M, Matsushita K, Fukagawa M, Maruyama T

Toxins (Toxins) 12 ( 8 ) 502 2020.08

Research paper (scientific journal), Joint Work, Accepted

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). Adipose tissue inflammation appears to be a risk factor for the progression of chronic kidney disease (CKD), but the effect of CKD on adipose tissue inflammation is poorly understood. The purpose of this study was to clarify the involvement of uremic toxins (indoxyl sulfate (IS), 3-indoleacetic acid, p-cresyl sulfate and kynurenic acid) on CKD-induced adipose tissue inflammation. IS induces monocyte chemoattractant protein-1 (MCP-1) expression and reactive oxygen species (ROS) production in the differentiated 3T3L-1 adipocyte. An organic anion transporter (OAT) inhibitor, an NADPH oxidase inhibitor or an antioxidant suppresses the IS-induced MCP-1 expression and ROS production, suggesting the OAT/NADPH oxidase/ROS pathway is involved in the action of IS. Co-culturing 3T3L-1 adipocytes and mouse macrophage cells showed incubating adipocytes with IS increased macrophage infiltration. An IS-overload in healthy mice increased IS levels, oxidative stress and MCP-1 expression in epididymal adipose tissue compared to unloaded mice. Using 5/6-nephrectomized mice, the administration of AST-120 suppressed oxidative stress and the expression of MCP-1, F4/80 and TNF-α in epididymal adipose tissue. These collective data suggest IS could be a therapeutic target for the CKD-related inflammatory response in adipose tissue, and that AST-120 could be useful for the treatment of IS-induced adipose tissue inflammation.

Concurrent administration with multivalent metal cation preparations or polycationic polymer preparations inhibits the absorption of raltegravir via its chelation.

Enoki Y, Suzuki N, Ito M, Uchiyama E, Kishi N, Ito C, Kitahiro Y, Sakamoto K, Taguchi K, Yokoyama Y, Kizu J, Matsumoto K

The Journal of pharmacy and pharmacology (Journal of Pharmacy and Pharmacology) 72 ( 10 ) 1361 - 1369 2020.07

Research paper (scientific journal), Joint Work, Accepted, ISSN 0022-3573

© 2020 Royal Pharmaceutical Society Objectives: Raltegravir (RAL) that can form chelates with multivalent metal cations shows lateral interactions with multivalent metal cation and polycationic polymer. We investigated the interactions of RAL with multivalent metal cation preparations, Al(OH)3 and LaCO3, and polycationic polymer preparations, bixalomer (Bxl) and sevelamer (Svl). Methods: Immediately before the oral administration of 40 mg/kg RAL, the rats were administered orally with the vehicle, Al(OH)3, LaCO3, Bxl, or Svl, and the time course of RAL serum concentration was followed. The in vitro binding affinity of RAL with multivalent metal cation and polycationic polymer was also evaluated using isothermal titration calorimetry (ITC). Results: When Al(OH)3, LaCO3, Bxl, or Svl was concomitantly administered with RAL, the maximum concentration and area under the curve were significantly lower than those when RAL was administered alone. ITC showed the interaction of RAL with Al(OH)3 as an enthalpy-driven reaction and its interactions with LaCO3 and Bxl as entropy–enthalpy mixed reactions. Conclusions: The interaction of RAL with Al(OH)3, LaCO3, Bxl, or Svl can inhibit RAL absorption into the gastrointestinal tract, and thus, the multivalent metal cation and polycationic polymer are the modifying factors that can affect RAL pharmacokinetics.

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Carbon monoxide rescues the developmental lethality of experimental rat models of rhabdomyolysis-induced acute kidney injury.

Taguchi K, Ogaki S, Nagasaki T, Yanagisawa H, Nishida K, Maeda H, Enoki Y, Matsumoto K, Sekijima H, Ooi K, Ishima Y, Watanabe H, Fukagawa M, Otagiri M, Maruyama T

The Journal of pharmacology and experimental therapeutics (Journal of Pharmacology and Experimental Therapeutics) 372 ( 3 ) 355 - 365 2020.01

Research paper (scientific journal), Accepted, ISSN 0022-3565

© 2020 by The American Society for Pharmacology and Experimental Therapeutics Many victims, after being extricated from a collapsed building as the result of a disaster, suffer from disaster nephrology, a term that is referred to as the crush syndrome (CS). Recommended treatments, which include dialysis or the continuous administration of massive amounts of fluid are not usually easy in cases of such mass natural disasters. In the present study, we examined the therapeutic performance of a biomimetic carbon monoxide (CO) delivery system, CO-enriched red blood cells (CO-RBCs), on experimental animal models of an acute kidney injury (AKI) induced by traumatic and nontraumatic rhabdomyolysis, including CS and rhabdomyolysis with massive hemorrhage shock. A single CO-RBC treatment was found to effectively suppress the pathogenesis of AKI with the mortality in these model rats being improved. In addition, in further studies using glycerol-induced rhabdomyolysis model rats, the pathogenesis of which is similar to that for the CS, AKI and mortality were also reduced as the result of a CO-RBC treatment. Furthermore, CO-RBCs were found to have renoprotective effects via the suppression of subsequent heme protein-associated renal oxidative injury; the oxidation of myoglobin in the kidneys, the generation of reactive oxygen species by free heme produced from degraded-cytochrome P450 and hemoglobin-associated renal injury. Because CO-RBCs can be prepared and used at both hospitals and at a disaster site, these findings suggest that CO-RBCs have the potential for use as a novel cell therapy against both nontraumatic and traumatic rhabdomyolysis including CS-induced AKI.

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Molecular mechanism of muscle wasting in CKD

Watanabe H, Enoki Y, Maruyama T

Recent Advances of Sarcopenia and Frailty in CKD (Recent Advances of Sarcopenia and Frailty in CKD) 15 - 33 2020.01

Research paper (scientific journal), Joint Work, Accepted, ISSN 9789811523649

© Springer Nature Singapore Pte Ltd. 2020. Chronic kidney disease (CKD), a chronic catabolic condition, is characterized by muscle wasting and a decreased muscle endurance. Many insights have made into the molecular mechanisms of muscle atrophy in CKD. A persistent imbalance between protein synthesis and degradation causes a loss of muscle mass. A decrease in insulin/IGF-1-Akt-mTOR signaling and an increased ubiquitin-proteasome system (UPS) have emerged as inducers of muscle loss. During muscle wasting, abnormal levels of reactive oxygen species (ROS) and inflammatory cytokines are detected in skeletal muscle. These increased ROS and inflammatory cytokine levels induce the expression of myostatin. The binding of myostatin to its receptor ActRIIB stimulates the expression of Foxo-dependent atrogenes. An impaired mitochondrial function also contributes to reduced muscle endurance. Increased glucocorticoid, angiotensin II, parathyroid hormone, and protein-bound uremic toxin levels that are observed in CKD all have a negative effect on muscle mass and endurance. The loss of skeletal muscle mass during the progression of CKD further contributes to the development of renal failure. Some potential therapeutic approaches based on the molecular mechanisms of muscle wasting in CKD are currently in the testing stages using animal models and clinical settings.

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Echinocandins versus non-echinocandins for empirical antifungal therapy in patients with hematological disease with febrile neutropenia: A systematic review and meta-analysis

Yamashita C, Takesue Y, Matsumoto K, Ikegame K, Enoki Y, Uchino M, Miyazaki T, Izumikawa K, Takada T, Okinaka K, Ueda T, Miyazaki Y, Mayumi T

Journal of Infection and Chemotherapy (Journal of Infection and Chemotherapy) 26 ( 6 ) 596 - 603 2020

Research paper (scientific journal), Joint Work, Accepted, ISSN 1341321X

© 2020 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases Empirical antifungal therapy is recommended in high-risk patients who have persistent febrile neutropenia (FN) despite broad-spectrum antibiotic therapy. Based on high-quality evidence, most guidelines recommend caspofungin. The aim of this study was to clarify whether echinocandins, including micafungin, are associated with improved clinical outcomes in patients with persistent FN. We conducted a meta-analysis of randomized controlled trials (RCTs) of empirical therapy with echinocandins and non-echinocandins for FN in patients with hematological disease. The primary outcome was all-cause mortality within 7 days after completion of therapy. Secondary outcomes included treatment success, and discontinuation of therapy because of adverse events. For subgroup analysis, we compared RCTs of echinocandins with liposomal amphotericin B. Six RCTs (four that evaluated caspofungin and two that evaluated micafungin) were included in the meta-analysis. Mortality and adverse events in echinocandin-treated patients were significantly lower than in those treated with non-echinocandins [risk ratio (RR) 0.70, 95% confidence interval (CI) 0.49–0.99; RR 0.48, 95% CI 0.33–0.71, respectively]. There was no significant difference in treatment success (RR 1.09, 95% CI 0.87–1.36). Mortality and adverse events in echinocandin-treated patients were significantly lower than in those treated with liposomal amphotericin B (RR 0.68, 95% CI 0.46–0.99; RR 0.53, 95% CI 0.37–0.74, respectively). In conclusion, patients with persistent FN treated with echinocandins had decreased risk of death and adverse events. Both caspofungin and micafungin may be recommended as first-line empirical antifungal therapy in these patients. However, the small number of enrolled patients and the lack of RCTs involving pediatric patients should be considered when using micafungin.

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Characterization of Bovine Lactoferrin Nanoparticle Prepared by Desolvation Technique.

Taguchi K, Chuang VTG, Hashimoto M, Nakayama M, Sakuragi M, Enoki Y, Nishi K, Matsumoto K, Seo H, Otagiri M, Yamasaki K

Chemical & pharmaceutical bulletin (公益社団法人日本薬学会) 68 ( 8 ) 766 - 772 2020

Research paper (scientific journal), Joint Work, Accepted, ISSN 0009-2363

Lactoferrin (Lf) nanoparticles have been developed as a carrier of drugs and gene. Two main methods, desolvation technique and emulsification method, for preparation of protein nanoparticles have been reported so far, but most of the previous reports of Lf nanoparticles preparation are limited to emulsification method. In this study, we investigated the optimal conditions by desolvation technique for the preparation of glutaraldehyde-crosslinked bovine Lf (bLf) nanoparticles within the size range of 100–200 nm, and evaluated their properties as a carrier for oral and intravenous drug delivery. The experimental results of dynamic light scattering and Transmission Electron Microscope suggested that glutaraldehyde-crosslinked bLf nanoparticles with 150 nm in size could be produced by addition of 2-propanol as the desolvating solvent into the bLf solution adjusted to pH 6, followed by crosslinking with glutaraldehyde. These cross-linked bLf nanoparticles were found to be compatible to blood components and resistant against rapid degradation by pepsin. Thus, cross-linked bLf nanoparticles prepared by desolvation technique can be applied as a drug carrier for intravenous administration and oral delivery.

Echinocandins versus non-echinocandins for the treatment of invasive candidiasis: A meta-analysis of randomized controlled trials

Tashiro S, Osa S, Igarashi Y, Watabe Y, Liu X, Enoki Y, Taguchi K, Mayumi T, Miyazaki Y, Takesue Y, Matsumoto K

Journal of Infection and Chemotherapy (Journal of Infection and Chemotherapy) 26 ( 11 ) 1164 - 1176 2020

Research paper (scientific journal), Joint Work, Accepted, ISSN 1341321X

© 2020 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases Introduction: Echinocandins are frequent use antifungals in the treatment of invasive candidiasis, and it is important to update information on their efficacy and safety for optimal antifungal drug treatment. The aim of this study is to clarify whether echinocandins are superior to non-echinocandins for the treatment of invasive candidiasis. Methods: We conducted a meta-analysis of RCTs of echinocandins and non-echinocandins for adult invasive candidiasis. The MEDLINE, Web of Sciences, Cochrane Register of Controlled Trials, and ClinicalTrials.gov databases before June 2019 were used. The risk ratio (RR) and 95% confidence interval (95% CI) were calculated using the Mantel-Haenszel method random-effects model. Results: We identified 14,846 articles and screened, and five studies were included meta-analysis. The treatment success ratio for echinocandins was significantly higher than that for non-echinocandins (RR = 1.14, 95% CI 1.06–1.22, p = 0.0003). In regard to adverse events, there was no significant difference between the two treatment groups. A subgroup analysis showed that the treatment success ratio for echinocandins was significantly higher than that for azoles (RR = 1.20, 1.08–1.34, p = 0.001), whereas no significant differences were observed between echinocandins and polyenes. In safety analysis, the incidence ratio of electrolyte disorder (RR = 0.50, 0.33–0.76, p = 0.001), renal disorder (RR = 0.19, 0.09–0.40, p < 0.0001), and fever (RR = 0.46, 0.23–0.93, p = 0.03) were significantly lower in patients receiving echinocandins than in those receiving polyenes. Conclusions: This meta-analysis based on RCTs was first to show that use of echinocandins was associated with improved clinical success. Echinocandins may be useful as a first-line drug for invasive candidiasis.

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Experimental verification of factors influencing calcium salt formation based on a survey of the development of ceftriaxone-induced gallstone-related disorder

Ito R., Yoshida A., Taguchi K., Enoki Y., Yokoyama Y., Matsumoto K.

Journal of Infection and Chemotherapy (Journal of Infection and Chemotherapy) 25 ( 12 ) 972 - 978 2019.12

Research paper (scientific journal), Accepted, ISSN 1341321X

© 2019 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases Ceftriaxone (CTRX) forms salts with calcium (Ca) in the gall bladder and bile duct, and induces the formation of gallstones. In this study, factors of CTRX-induced gallstone formation were extracted from the results of a retrospective survey using the Japanese Adverse Drug Event Report (JADER), and the causal relationship between the factors and gallstone formation was investigated. From JADER, 136 patients who developed ‘gallstone-related disorder’ with CTRX as a suspected drug were extracted. The incidence of gallstone-induced adverse effects was high in patients treated with CTRX at a dose exceeding the normal daily dose and in children younger than 10 years old, suggesting that CTRX at a high level is a factor for gallstone formation. Thus, after mixing CTRX and Ca2+ at different concentrations under different pH condition, the number of particles in the solutions was measured using a Coulter counter. As a result, the number of minute particles significantly increased at all pH values when Ca2+ and CTRX were mixed at a concentration of 10 mEq/L or higher and 1.5 g/L or higher, respectively. At pH 6.5 or 7.0, visible crystals were detected when 25 mEq/L of Ca2+ and 2.0 g/L of CTRX were mixed. Based on these findings, attention should be sufficiently paid to the development of ‘gallstone-related disorder’ in pediatric patients and in patients treated with CTRX at a dose exceeding the normal dose. Furthermore, gallstone formation and growth may be promoted when CTRX and Ca2+ coexist at high concentrations under low pH conditions.

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A selection table for information on heparinoid-containing preparation

Ishiwatari R, Enoki Y, Yokoyama Y, Taguchi K, Kizu J, Matsumoto K

Journal of Geriatric Pharmacy (Japanese Society of Geriatric Pharmacy) 2 ( 2 ) 19 - 26 2019.09

Research paper (scientific journal), Joint Work, Accepted

We evaluated heparinoid-containing soft ointments and heparinoid-containing creams to develop information useful to select drugs. Spreadability, consistency and the water content of stratum corneum was measured. A selection table focusing on impression of the use was prepared. Spreadability of the semi-original soft ointment and cream were lower than those of all generic drugs. Regarding hardness, one generic soft ointment was softer than the semi-original drug, but the semi-original cream was harder than all generic creams. Regarding the impression of the use, a significant difference was noted in smell in soft ointments, and 6 items in creams. Correlation was found between the spreadability and consistency test results and impression of the use. A significant difference was noted in the water content of stratum corneum in creams. The selection table prepared based on the impression of the use may provide information that helps selection of preparations in clinical practice.

Evaluation for optimal dosing of vancomycin in patients with different physical types

Hashimoto M., Iketani O., Ichinose N., Enoki Y., Taguchi K., Uno S., Uwamino Y., Hasegawa N., Matsumoto K.

Journal of Infection and Chemotherapy (Journal of Infection and Chemotherapy) 25 ( 9 ) 735 - 737 2019.09

Research paper (scientific journal), Accepted, ISSN 1341321X

© 2019 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases The sufficient dose to obtain an optimal trough concentration of vancomycin (VCM) in patients with non-standard physical types remains controversial. In this study, we examined the relationship between the dose and physical type in patients in whom an optimal trough concentration was obtained among VCM-treated patients. We retrospectively investigated the dose of VCM and physical type in patients treated with VCM between January 2012 and January 2017 at two medical institutions (n = 272). The physical type was classified using the body mass index (BMI). Patients with a BMI of <18.5 kg/m2 were assigned to the lean group, those with a BMI of 18.5–24.9 kg/m2 were assigned to the standard group, and those with a BMI of ≥25 kg/m2 were assigned to the obesity group. The mean doses of VCM per time (mg/kg) to achieve the target trough concentration of VCM, 15–20 μg/mL, were 19.8 ± 4.3, 16.5 ± 3.7, and 13.7 ± 2.7 mg/kg in the lean, standard, and obesity groups, respectively. The dose per time to achieve the target trough concentration decreased significantly in association with an increase of BMI. The upper limit of the recommended dose (15–20 mg/kg) or higher in lean patients, and the lower dose in obese patients than the recommended dose might be appropriate to achieve the target trough concentration when we calculated the dose per time based on actual body weight.

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Age-Associated Theophylline Metabolic Activity Corresponds to the Ratio of 1,3-Dimethyluric Acid to Theophylline in Mice

Kuroda Yuko, Taguchi Kazuaki, Enoki Yuki, Matsumoto Kazuaki, Hori Seiji, Kizu Junko

Biological and Pharmaceutical Bulletin (The Pharmaceutical Society of Japan) 42 ( 8 ) 1423 - 1427 2019

Research paper (scientific journal), Accepted, ISSN 09186158

Age is known as one of influencing factor for theophylline (TP)-metabolizing capacity. In a previous our study, the ratio of TP and its major metabolite 1,3-dimethyluric acid (DMU) in serum (DMU/TP) is a useful index to estimate TP-metabolizing capacity, and this value markedly increased by influencing factor, such as the history of smoking. However, it is unknown whether DMU/TP values in serum reflect age-associated changes of TP-metabolizing capacity. In this study, the effect of age on the DMU/TP values in serum were investigated using mice of different age due to the limited blood sampling in human. The concentrations of TP and its metabolites in mouse serum were simultaneously measured using HPLC. As observed in human serum, serum TP concentrations were closely correlated with DMU concentration in mice, which indicates that the DMU/TP ratio is a good indicator of TP metabolic ability in mice. When TP was administered subcutaneously in 2–28-week-old mice, age-associated changes in the DMU/TP ratio in mice were observed. In conclusion, age-associated changes in TP-metabolizing capacity can be estimated by the DMU/TP ratio in serum.

Support for fungal infection treatment mediated by pharmacist-led antifungal stewardship activities

Samura M., Hirose N., Kurata T., Ishii J., Nagumo F., Takada K., Koshioka S., Uchida M., Yamamoto S., Inoue J., Enoki Y., Taguchi K., Ishida A., Sekine H., Kunika N., Kunishima H., Matsumoto K.

Journal of Infection and Chemotherapy (Journal of Infection and Chemotherapy) 26 ( 3 ) 272 - 279 2019

Research paper (scientific journal), Accepted, ISSN 1341321X

© 2019 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases Objective: At the Yokohama General Hospital, pharmacist-led antimicrobial stewardship programs (ASP) including antifungal stewardship programs (AFP) were started in 2012. To investigate the efficacy of the programs, we compared several parameters that are recommended for the measurement of ASP in Japan based on pre- and post-AFP activities. Patients and methods: The subjects were inpatients who developed candidemia between April 2008 and March 2016. They were divided into two groups: pre-AFP (April 2008 until March 2012) and post-AFP (April 2012 until March 2016). The results were compared between the two groups. Results: The cumulative optimal antifungal drug usage rate, as a process parameter, significantly increased in the post-AFP group (p = 0.025). Furthermore, the days of therapy of antifungal drugs in the pre- and post-AFP groups was median 6.0 (interquartile range [IQR] 0.3–15.7) and median 3.4 (IQR 1.9–3.4) per 1,000 patient-days, respectively; there was a significant decrease in the post-AFP group (p < 0.001). Expenditure on antifungal drugs, as an outcome parameter, in the pre- and post-AFP groups was 9390.5 ± 5687.1 and 5930.8 ± 4687.0 US dollars, respectively; there was a significant decrease in the post-AFP group (p = 0.002). Conclusions: These results suggest that pharmacist-led antifungal stewardship activities improve both outcome and process parameters.

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Sarcopenia in Chronic Kidney Disease: Factors, Mechanisms, and Therapeutic Interventions

Watanabe Hiroshi, Enoki Yuki, Maruyama Toru

Biological and Pharmaceutical Bulletin (The Pharmaceutical Society of Japan) 42 ( 9 ) 1437 - 1445 2019

Research paper (scientific journal), Accepted, ISSN 09186158

Chronic kidney disease (CKD), a chronic catabolic condition, is characterized by muscle wasting and decreased muscle endurance. Many insights into the molecular mechanisms of muscle wasting in CKD have been obtained. A persistent imbalance between protein degradation and synthesis in muscle causes muscle wasting. During muscle wasting, high levels of reactive oxygen species (ROS) and inflammatory cytokines are detected in muscle. These increased ROS and inflammatory cytokine levels induce the expression of myostatin. The myostatin binding to its receptor activin A receptor type IIB stimulates the expression of atrogenes such as atrogin-1 and muscle ring factor 1, members of the muscle-specific ubiquitin ligase family. Impaired mitochondrial function also contributes to reducing muscle endurance. The increased protein-bound uremic toxin, parathyroid hormone, glucocorticoid, and angiotensin II levels that are observed in CKD all have a negative effect on muscle mass and endurance. Among the protein-bound uremic toxins, indoxyl sulfate, an indole-containing compound has the potential to induce muscle atrophy by stimulating ROS-mediated myostatin and atrogenes expression. Indoxyl sulfate also impairs mitochondrial function. Some potential therapeutic approaches based on the muscle wasting mechanisms in CKD are currently in the testing stages.

Evaluation of the Expression Time of Ganciclovir-Induced Adverse Events Using JADER and FAERS

Ando Go, Taguchi Kazuaki, Enoki Yuki, Yokoyama Yuta, Kizu Junko, Matsumoto Kazuaki

Biological and Pharmaceutical Bulletin (The Pharmaceutical Society of Japan) 42 ( 11 ) 1799 - 1804 2019

Research paper (scientific journal), Accepted, ISSN 09186158

Investigation of the occurrence time of adverse drug reactions helps to prevent the development and aggravation of adverse reactions, but the expression time of ganciclovir-induced adverse events has not been elucidated. In this study, using databases of spontaneous adverse event reports, the Japanese Adverse Drug Event Report database (JADER) and the U.S. Food and Drug Administration (FDA)’s Adverse Event Reporting System (FAERS), the incidence of adverse reactions due to ganciclovir and their expression time were analyzed. As a result of calculation of the reporting odds ratio (ROR) and 95% confidence interval for individual main adverse reactions of ganciclovir (cytopenia, leukopenia, thrombocytopenia, liver damage, and acute renal failure), a signal was detected for all adverse reactions in both databases, except for liver damage in JADER. Furthermore, the Weibull distribution was performed for the analysis of onset time of each ganciclovir-induced adverse event. The results of Weibull parameter α and β values of each adverse event in both JADER and FAERS suggested that most adverse events occurred within 30 d and classified into the early failure type, except that thrombocytopenia and acute renal failure in JADER classified into the random failure type. Based on these findings, it concluded that the paying attention to signs of each ganciclovir-induced adverse event is required from the early phase after ganciclovir administration. However, in FAERS, development after a long-term course also accounted for 11%, suggesting that long-term periodic monitoring of adverse reactions would be also required.

Pharmacokinetic and pharmacodynamic studies of pregabalin suppositories based on pharmacological research.

Yajima; Ryo; Matsumoto, Kazuaki; Yokono, Kanako; Watabe, Yuki; Enoki, Yuki; Taguchi, Kazuaki; Ise, Yuya; Katayama, Shiro; Kizu, Junko

Journal of pharmacy and pharmacology (Journal of Pharmacy and Pharmacology) 71 ( 5 ) 746 - 752 2018.12

Research paper (scientific journal), Joint Work, Accepted, ISSN 2042-7158

© 2018 Royal Pharmaceutical Society Objectives: As commercially available pregabalin preparations are limited to oral administration, it is impossible to use it as an adjuvant analgesic for neuropathic cancer-related pain in terminally ill cancer patients with oral feeding difficulties. The objective of this study was to develop a pregabalin suppository to be available at hospitals. Methods: Pregabalin suppositories were prepared using bases comprising six different compositions of Witepsol H-15, Witepsol S-55, and Witepsol E-75. The suppository release test and stability test were performed in vitro. The pharmacokinetics and pharmacodynamics of the suppositories were assessed in rats. Key findings: In the in vitro releasing test, the pregabalin suppositories with H-15, H-15 : S-55 = 1 : 1, H-15 : S-55 = 2 : 1, H-15 : S-55 = 1 : 2 released approximately 100% of the pregabalin within 180 min. Among these pregabalin suppositories, only the suppository with H-15 : S-55 = 2 : 1 demonstrated an equivalent AUC 0−∞ with the oral administration group. Consistent with the results of the pharmacokinetic study, the pregabalin suppository with H-15 : S-55 = 2 : 1 exhibited antinociceptive effects. In addition, the pregabalin suppository with H-15 : S-55 = 2 : 1 was stable for 12 weeks when refrigerated with light shielding. Conclusions: The pregabalin suppositories prepared in this study may be applicable for pain control for terminally cancer ill patients with oral feeding difficulties.

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Oral vancomycin versus metronidazole for the treatment of Clostridioides difficile infection: Meta-analysis of randomized controlled trials

Igarashi, Yuki, Tashiro, Sho, Enoki, Yuki, Taguchi, Kazuaki, Matsumoto, Kazuaki, Ohge, Hiroki, Suzuki, Hiromichi, Nakamura, Atsushi, Mori, Nobuaki, Morinaga, Yoshitomo, Yamagishi, Yuka, Yoshizawa, Sadako, Yanagihara, Katsunori, Mikamo, Hiroshige, Kunishima, Hiroyuki

JOURNAL OF INFECTION AND CHEMOTHERAPY (Journal of Infection and Chemotherapy) 24 ( 11 ) 907 - 914 2018.12

Research paper (scientific journal), Joint Work, Accepted, ISSN 1341-321X

© 2018 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases At present, vancomycin (VCM) and metronidazole (MNZ) are used for the first-line standard treatment of Clostridioides difficile infection (CDI). However, their differential use has not been sufficiently investigated. In this study, a meta-analysis on differences in the efficacy for CDI between VCM and MNZ was performed. Reports of randomized controlled studies using VCM or MNZ to treat CDI were surveyed. Meta-analysis was performed using the Mantel-Haenszel method and random-effects model, and the risk ratio and 95% confidence interval were calculated. Excluding overlapping reports, 1043 reports were extracted and 5 randomized controlled studies were extracted. There was no difference in therapeutic effects for CDI between VCM and MNZ (RR = 1.08, 95% CI (0.99–1.17), p = 0.09, I2 = 37%). On subgroup analysis by the severity, there was no difference in the clinical effects for CDI between VCM and MNZ in non-severe cases (risk ratio: 1.09, 95% confidence interval: 1.00–1.19, p = 0.06), but the clinical effects of VCM were significantly higher than those of MNZ in severe cases (risk ratio: 1.19, 95% confidence interval: 1.02–1.39, p = 0.03). No significant difference was noted in the recurrence rate, incidence of adverse event, time to exhibit therapeutic effects, or judgment of the bacteriological effects. As the therapeutic effects of VCM were superior in severe CDI cases, VCM should be considered first in severe cases.

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Stability of benzylpenicillin potassium and ampicillin in an elastomeric infusion pump

Nakamura, Tomomi, Enoki, Yuki, Uno, Shunsuke, Uwamino, Yoshifumi, Iketani, Osamu, Hasegawa, Naoki, Matsumoto, Kazuaki

JOURNAL OF INFECTION AND CHEMOTHERAPY (Journal of Infection and Chemotherapy) 24 ( 10 ) 856 - 859 2018.10

Research paper (scientific journal), Single Work, Accepted, ISSN 1341-321X

© 2018 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases Some infectious diseases, such as infective endocarditis, osteomyelitis, and abscesses, require treatment with long-term intravenous antimicrobial treatment. Therefore, the patient is required to stay in the hospital to receive therapy, which lowers their quality of life. Establishing an outpatient parenteral antimicrobial therapy (OPAT) by continuous infusion pump is desired in Japan to overcome these issues. However, the 24-h stability of antimicrobial agents dissolved in infusion solutions is unclear. Thus, we investigated the stability of antimicrobial agents in five different infusion solutions in a clinical setting. Benzylpenicillin potassium (PCG) and ampicillin (ABPC) were dissolved separately in five different infusion solutions and kept at 25 or 31.1 °C for 24 h. The residual ratios were determined by high-performance liquid chromatography (HPLC). Dissolved PCG in acetate ringer solution remained stable for 24 h at temperatures of 25 and 31.1 °C (101.7 ± 1.4% and 92.9 ± 1.3%, respectively). In addition, the PCG solution did not adsorb onto the elastomeric infusion pump after 24 h at 31.1 °C. PCG dissolved in acetate ringer solution was also stable for 10 days after being kept in an elastomeric infusion pump at 4 °C (99.7 ± 0.5%). ABPC was unstable in all of the tested infusion solutions and temperatures. Based on our results, PCG in acetate ringer solution can be used in OPAT with continuous infusion pumps.

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Development of Kupffer cell targeting type-I interferon for the treatment of hepatitis via inducing anti-inflammatory and immunomodulatory actions

Minayoshi, Yuki, Maeda, Hitoshi, Yanagisawa, Hiroki, Hamasaki, Keisuke, Mizuta, Yuki, Nishida, Kento, Kinoshita, Ryo, Enoki, Yuki, Imafuku, Tadasi, Chuang, Victor Tuan Giam, Koga, Tomoaki, Fujiwara, Yukio, Takeya, Motohiro, Sonoda, Kayoko, Wakayama, Tomohiko, Taguchi, Kazuaki, Ishima, Yu, Ishida, Tatsuhiro, Iwakiri, Yasuko, Tanaka, Motohiko, Sasaki, Yutaka, Watanabe, Hiroshi, Otagiri, Masaki, Maruyama, Toru

DRUG DELIVERY (Drug Delivery) 25 ( 1 ) 1067 - 1077 2018.04

Research paper (scientific journal), Joint Work, Accepted, ISSN 1071-7544

Because of its multifaceted anti-inflammatory and immunomodulatory effects, delivering type-I interferon to Kupffer cells has the potential to function as a novel type of therapy for the treatment of various types of hepatitis. We report herein on the preparation of a Kupffer cell targeting type-I interferon, an albumin-IFNα2b fusion protein that contains highly mannosylated N-linked oligosaccharide chains, Man-HSA(D494N)-IFNα2b, attached by combining albumin fusion technology and site-directed mutagenesis. The presence of this unique oligosaccharide permits the protein to be efficiently, rapidly and preferentially distributed to Kupffer cells. Likewise IFNα2b, Man-HSA(D494N)-IFNα2b caused a significant induction in the mRNA levels of IL-10, IL-1Ra, PD-L1 in RAW264.7 cells and mouse isolated Kupffer cells, and these inductions were largely inhibited by blocking the interferon receptor. These data indicate that Man-HSA(D494N)-IFNα2b retained the biological activities of type-I interferon. Man-HSA(D494N)-IFNα2b significantly inhibited liver injury in Concanavalin A (Con-A)-induced hepatitis model mice, and consequently improved their survival rate. Moreover, the post-administration of Man-HSA(D494N)-IFNα2b at 2 h after the Con-A challenge also exerted hepato-protective effects. In conclusion, this proof-of-concept study demonstrates the therapeutic effectiveness and utility of Kupffer cell targeting type-I interferon against hepatitis via its anti-inflammatory and immunomodulatory actions.

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Design and tuning of a cell-penetrating albumin derivative as a versatile nanovehicle for intracellular drug delivery

Ichimizu, S., Watanabe, H., Maeda, H., Hamasaki, K., Nakamura, Y., Chuang, V. T. G., Kinoshita, R., Nishida, K., Tanaka, R., Enoki, Y., Ishima, Y., Kuniyasu, A., Kobashigawa, Y., Morioka, H., Futaki, S., Otagiri, M. and Maruyama, T.

J Control Release (Journal of Controlled Release) 277 23 - 34 2018.03

Research paper (scientific journal), Joint Work, Accepted, ISSN 1873-4995

Human serum albumin (HSA) is a superior carrier for delivering extracellular drugs. However, the development of a cell-penetrating HSA remains a great challenge due to its low membrane permeability. We report herein on the design of a series of palmitoyl-poly-arginine peptides (CPPs) and an evaluation of their cell-penetrating effects after forming a complex with HSA for use in intracellular drug delivery. The palmitoyl CPPs forms a stable complex with HSA by anchoring itself to the high affinity palmitate binding sites of HSA. Among the CPPs evaluated, a cyclic polypeptide composed of D-dodecaarginines, palmitoyl-cyclic-(D-Arg)12 was the most effective for facilitating the cellular uptake of HSA by HeLa cells. Such a superior cell-penetrating capability is primarily mediated by macropinocytosis. The effect of the CPP on pharmacological activity was examined using three drugs loaded in HSA via three different methods: a) an HSA-paclitaxel complex, b) an HSA-doxorubicin covalent conjugate and c) an HSA-thioredoxin fusion protein. The results showed that cell-penetrating efficiency was increased with a corresponding and significant enhancement in pharmacological activity. In conclusion, palmitoyl-cyclic-(D-Arg)12/HSA is a versatile cell-penetrating drug delivery system with great potential for use as a nano-carrier for a wide diversity of pharmaceutical applications.

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Parathyroid hormone contributes to the down-regulation of cytochrome P450 3A through the cAMP/PI3K/PKC/PKA/NF-kappaB signaling pathway in secondary hyperparathyroidism

Watanabe, H., Sugimoto, R., Ikegami, K., Enoki, Y., Imafuku, T., Fujimura, R., Bi, J., Nishida, K., Sakaguchi, Y., Murata, M., Maeda, H., Hirata, K., Jingami, S., Ishima, Y., Tanaka, M., Matsushita, K., Komaba, H., Fukagawa, M., Otagiri, M. and Maruyama, T.

Biochem Pharmacol (Biochemical Pharmacology) 145 192 - 201 2017.12

Research paper (scientific journal), Joint Work, Accepted, ISSN 0006-2952

Chronic kidney disease (CKD), which affects, not only renal clearance, but also non-renal clearance, is accompanied by a decline in renal function. Although it has been suggested that humoral factors, such as uremic toxins that accumulate in the body under CKD conditions, could be involved in the changes associated with non-renal drug clearance, the overall process is not completely understood. In this study, we report on the role of parathyroid hormone (PTH), a middle molecule uremic toxin, on the expression of drug metabolizing or transporting proteins using rats with secondary hyperparathyroidism (SHPT) as models. In SHPT rats, hepatic and intestinal CYP3A expression was suppressed, but the changes were recovered by the administration of the calcimimetic cinacalcet, a PTH suppressor. Under the same experimental conditions, a pharmacokinetic study using orally administered midazolam, a substrate for CYP3A, showed that the AUC was increased by 5 times in SHPT rats, but that was partially recovered by a cinacalcet treatment. This was directly tested in rat primary hepatocytes and intestinal Caco-2 cells where the expression of the CYP3A protein was down-regulated by PTH (1-34). In Caco-2 cells, PTH (1-34) down-regulated the expression of CYP3A mRNA, but an inactive PTH derivative (13-34) had no effect. 8-Bromo-cyclic adenosine monophosphate, a membrane-permeable cAMP analog, reduced mRNA expression of CYP3A whereas the inhibitors of PI3K, NF-kappaB, PKC and PKA reversed the PTH-induced CYP3A down-regulation. These results suggest that PTH down-regulates CYP3A through multiple signaling pathways, including the PI3K/PKC/PKA/NF-kappaB pathway after the elevation of intracellular cAMP, and the effect of PTH can be prevented by cinacalcet treatment.

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Potential therapeutic interventions for chronic kidney disease-associated sarcopenia via indoxyl sulfate-induced mitochondrial dysfunction

Enoki, Y., Watanabe, H., Arake, R., Fujimura, R., Ishiodori, K., Imafuku, T., Nishida, K., Sugimoto, R., Nagao, S., Miyamura, S., Ishima, Y., Tanaka, M., Matsushita, K., Komaba, H., Fukagawa, M., Otagiri, M. and Maruyama, T.

J Cachexia Sarcopenia Muscle (Journal of Cachexia, Sarcopenia and Muscle) 8 ( 5 ) 735 - 747 2017.10

Research paper (scientific journal), Joint Work, Accepted, ISSN 2190-5991

BACKGROUND: Chronic kidney disease (CKD) patients experience skeletal muscle wasting and decreased exercise endurance. Our previous study demonstrated that indoxyl sulfate (IS), a uremic toxin, accelerates skeletal muscle atrophy. The purpose of this study was to examine the issue of whether IS causes mitochondria dysfunction and IS-targeted intervention using AST-120, which inhibits IS accumulation, or mitochondria-targeted intervention using L-carnitine or teneligliptin, a dipeptidyl peptidase-4 inhibitor which retains mitochondria function and alleviates skeletal muscle atrophy and muscle endurance in chronic kidney disease mice. METHODS: The in vitro effect of IS on mitochondrial status was evaluated using mouse myofibroblast cells (C2C12 cell). The mice were divided into sham or 5/6-nephrectomized (CKD) mice group. Chronic kidney disease mice were also randomly assigned to non-treatment group and AST-120, L-carnitine, or teneligliptin treatment groups. RESULTS: In C2C12 cells, IS induced mitochondrial dysfunction by decreasing the expression of PGC-1alpha and inducing autophagy in addition to decreasing mitochondrial membrane potential. Co-incubation with an anti-oxidant, ascorbic acid, L-carnitine, or teneligliptine restored the values to their original state. In CKD mice, the body and skeletal muscle weights were decreased compared with sham mice. Compared with sham mice, the expression of interleukin-6 and atrophy-related factors such as myostatin and atrogin-1 was increased in the skeletal muscle of CKD mice, whereas muscular Akt phosphorylation was decreased. In addition, a reduced exercise capacity was observed for the CKD mice, which was accompanied by a decreased expression of muscular PCG-1alpha and increased muscular autophagy, as reflected by decreased mitochondria-rich type I fibres. An AST-120 treatment significantly restored these changes including skeletal muscle weight observed in CKD mice to the sham levels accompanied by a reduction in IS levels. An L-carnitine or teneligliptin treatment also restored them to the sham levels without changing IS level. CONCLUSIONS: Our results indicate that IS induces mitochondrial dysfunction in skeletal muscle cells and provides a potential therapeutic strategy such as IS-targeted and mitochondria-targeted interventions for treating CKD-induced muscle atrophy and decreased exercise endurance.

Down-regulation of ABCG2, a urate exporter, by parathyroid hormone enhances urate accumulation in secondary hyperparathyroidism

Sugimoto, R., Watanabe, H., Ikegami, K., Enoki, Y., Imafuku, T., Sakaguchi, Y., Murata, M., Nishida, K., Miyamura, S., Ishima, Y., Tanaka, M., Matsushita, K., Komaba, H., Fukagawa, M., Otagiri, M. and Maruyama, T.

Kidney Int (ELSEVIER SCIENCE INC) 91 ( 3 ) 658 - 670 2017.03

Research paper (scientific journal), Joint Work, Accepted, ISSN 0085-2538

Hyperuricemia occurs with increasing frequency among patients with hyperparathyroidism. However, the molecular mechanism by which the serum parathyroid hormone (PTH) affects serum urate levels remains unknown. This was studied in uremic rats with secondary hyperparathyroidism where serum urate levels were found to be increased and urate excretion in the intestine and kidney decreased, presumably due to down-regulation of the expression of the urate exporter ABCG2 in intestinal and renal epithelial membranes. These effects were prevented by administration of the calcimimetic cinacalcet, a PTH suppressor, suggesting that PTH may down-regulate ABCG2 expression. This was directly tested in intestinal Caco-2 cells where the expression of ABCG2 on the plasma membrane was down-regulated by PTH (1-34) while its mRNA level remained unchanged. Interestingly, an inactive PTH derivative (13-34) had no effect, suggesting that a posttranscriptional regulatory system acts through the PTH receptor to regulate ABCG2 plasma membrane expression. As found in an animal study, additional clinical investigations showed that treatment with cinacalcet resulted in significant reductions in serum urate levels together with decreases in PTH levels in patients with secondary hyperparathyroidism undergoing dialysis. Thus, PTH down-regulates ABCG2 expression on the plasma membrane to suppress intestinal and renal urate excretion, and the effects of PTH can be prevented by cinacalcet treatment.

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Indoxyl sulfate potentiates skeletal muscle atrophy by inducing the oxidative stress-mediated expression of myostatin and atrogin-1

Enoki, Yuki, Watanabe, Hiroshi, Arake, Riho, Sugimoto, Ryusei, Imafuku, Tadashi, Tominaga, Yuna, Ishima, Yu, Kotani, Shunsuke, Nakajima, Makoto, Tanaka, Motoko, Matsushita, Kazutaka, Fukagawa, Masafumi, Otagiri, Masaki and Maruyama, Toru

Scientific Reports (NATURE PUBLISHING GROUP) 6 32084 2016.08

Research paper (scientific journal), Joint Work, Accepted, ISSN 2045-2322

Skeletal muscle atrophy, referred to as sarcopenia, is often observed in chronic kidney disease ( CKD) patients, especially in patients who are undergoing hemodialysis. The purpose of this study was to determine whether uremic toxins are involved in CKD-related skeletal muscle atrophy. Among six protein-bound uremic toxins, indole containing compounds, indoxyl sulfate ( IS) significantly inhibited proliferation and myotube formation in C2C12 myoblast cells. IS increased the factors related to skeletal muscle breakdown, such as reactive oxygen species ( ROS) and inflammatory cytokines ( TNF-alpha, IL-6 and TGF-beta 1) in C2C12 cells. IS also enhanced the production of muscle atrophy-related genes, myostatin and atrogin-1. These effects induced by IS were suppressed in the presence of an antioxidant or inhibitors of the organic anion transporter and aryl hydrocarbon receptor. The administered IS was distributed to skeletal muscle and induced superoxide production in half-nephrectomized ( 1/2 Nx) mice. The chronic administration of IS significantly reduced the body weights accompanied by skeletal muscle weight loss. Similar to the in vitro data, IS induced the expression of myostatin and atrogin-1 in addition to increasing the production of inflammatory cytokines by enhancing oxidative stress in skeletal muscle. These data suggest that IS has the potential to accelerate skeletal muscle atrophy by inducing oxidative stress-mediated myostatin and atrogin-1 expression.

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OAT-DEPENDENT CELLULAR ACCUMULATION OF P-CRESYL SULFATE, A UREMIC TOXIN, CAUSES VASCULAR ENDOTHELIAL AND SMOOTH MUSCLE CELL DAMAGES BY INDUCING OXIDATIVE STRESS

Watanabe Hiroshi, Miyamoto Yohei, Enoki Yuki, Ishima Yu, Fukagawa Masafumi, Otagiri Masaki, Maruyama Toru

DRUG METABOLISM REVIEWS 47 175 - 175 2015.11

Research paper (scientific journal), Joint Work, Accepted, ISSN 0360-2532

p-Cresyl sulfate, a uremic toxin, causes vascular endothelial and smooth muscle cell damages by inducing oxidative stress

Watanabe, H., Miyamoto, Y., Enoki, Y., Ishima, Y., Kadowaki, D., Kotani, S., Nakajima, M., Tanaka, M., Matsushita, K., Mori, Y., Kakuta, T., Fukagawa, M., Otagiri, M. and Maruyama, T.

Pharmacol Res Perspect (Pharmacology Research and Perspectives) 3 ( 1 ) e00092 - 12 2015.02

Research paper (scientific journal), Joint Work, Accepted, ISSN 2052-1707

The major cause of death in patients with chronic kidney disease (CKD) is cardiovascular disease. Here, p-Cresyl sulfate (PCS), a uremic toxin, is considered to be a risk factor for cardiovascular disease in CKD. However, our understanding of the vascular toxicity induced by PCS and its mechanism is incomplete. The purpose of this study was to determine whether PCS enhances the production of reactive oxygen species (ROS) in vascular endothelial and smooth muscle cells, resulting in cytotoxicity. PCS exhibited pro-oxidant properties in human umbilical vein endothelial cells (HUVEC) and aortic smooth muscle cells (HASMC) by enhancing NADPH oxidase expression. PCS also up-regulates the mRNA levels and the protein secretion of monocyte chemotactic protein-1 (MCP-1) in HUVEC. In HASMC, PCS increased the mRNA levels of alkaline phosphatase (ALP), osteopontin (OPN), core-binding factor alpha 1, and ALP activity. The knockdown of Nox4, a subunit of NADPH oxidase, suppressed the cell toxicity induced by PCS. The vascular damage induced by PCS was largely suppressed in the presence of probenecid, an inhibitor of organic anion transporters (OAT). In PCS-overloaded 5/6-nephrectomized rats, plasma MCP-1 levels, OPN expression, and ALP activity of the aortic arch were increased, accompanied by the induction of Nox4 expression. Collectively, the vascular toxicity of PCS can be attributed to its intracellular accumulation via OAT, which results in an enhanced NADPH oxidase expression and increased ROS production. In conclusion, we found for the first time that PCS could play an important role in the development of cardiovascular disease by inducing vascular toxicity in the CKD condition.

Pleiotropic Effects of Levofloxacin, Fluoroquinolone Antibiotics, against Influenza Virus-Induced Lung Injury

Enoki, Y., Ishima, Y., Tanaka, R., Sato, K., Kimachi, K., Shirai, T., Watanabe, H., Chuang, V. T., Fujiwara, Y., Takeya, M., Otagiri, M. and Maruyama, T.

PLoS One (PUBLIC LIBRARY SCIENCE) 10 ( 6 ) e0130248 2015

Research paper (scientific journal), Joint Work, Accepted, ISSN 1932-6203

Reactive oxygen species (ROS) and nitric oxide (NO) are major pathogenic molecules produced during viral lung infections, including influenza. While fluoroquinolones are widely used as antimicrobial agents for treating a variety of bacterial infections, including secondary infections associated with the influenza virus, it has been reported that they also function as anti-oxidants against ROS and as a NO regulator. Therefore, we hypothesized that levofloxacin (LVFX), one of the most frequently used fluoroquinolone derivatives, may attenuate pulmonary injuries associated with influenza virus infections by inhibiting the production of ROS species such as hydroxyl radicals and neutrophil-derived NO that is produced during an influenza viral infection. The therapeutic impact of LVFX was examined in a PR8 (H1N1) influenza virus-induced lung injury mouse model. ESR spin-trapping experiments indicated that LVFX showed scavenging activity against neutrophil-derived hydroxyl radicals. LVFX markedly improved the survival rate of mice that were infected with the influenza virus in a dose-dependent manner. In addition, the LVFX treatment resulted in a dose-dependent decrease in the level of 8-hydroxy-2'-deoxyguanosine (a marker of oxidative stress) and nitrotyrosine (a nitrative marker) in the lungs of virus-infected mice, and the nitrite/nitrate ratio (NO metabolites) and IFN-gamma in BALF. These results indicate that LVFX may be of substantial benefit in the treatment of various acute inflammatory disorders such as influenza virus-induced pneumonia, by inhibiting inflammatory cell responses and suppressing the overproduction of NO in the lungs.

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Possible false-negative results on therapeutic drug monitoring of phenytoin using a particle enhanced turbidimetric inhibition immunoassay in a patient with a high level of IgM

Hirata, K., Saruwatari, J., Enoki, Y., Iwata, K., Urata, Y., Aizawa, K., Ueda, K., Shirouzono, T., Imamura, M., Moriuchi, H., Ishima, Y., Kadowaki, D., Watanabe, H., Hirata, S., Maruyama, T. and Fukunaga, E.

Ther Drug Monit (Therapeutic Drug Monitoring) 36 ( 5 ) 553 - 5 2014.10

Research paper (scientific journal), Joint Work, Accepted, ISSN 0163-4356

: In this report, the authors described the unusual case of a patient in whom the plasma phenytoin concentration was unexpectedly not detected on a particle-enhanced turbidimetric inhibition immunoassay (PETINIA) technique, a typical immunoassay for phenytoin. The plasma concentration was measured using PETINIA and high-performance liquid chromatography in a 69-year-old male patient treated with fosphenytoin intravenously at the standard dose for 7 days. Although the plasma concentration of phenytoin was below the limit of detection (<0.5 mcg/mL) on PETINIA after the administration of fosphenytoin, the trough plasma concentration was estimated to be between 5 and 10 mg/L on high-performance liquid chromatography. When the plasma concentrations of IgM and IgG were measured using an enzyme-linked immunosorbent assay, the plasma IgG level was within the reference range, whereas the plasma IgM level was 2-3 times higher than the upper limit of the reference range. We concluded that the PETINIA method yielded a possible false-negative result regarding the phenytoin level in this patient, perhaps because of some hindrance to the measurement process by IgM. This case suggests that false-negative results should be considered when therapeutic drug monitoring reveals abnormally low values using PETINIA and that it is necessary to evaluate the plasma IgM level.

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Therapeutic impact of human serum albumin-thioredoxin fusion protein on influenza virus-induced lung injury mice

Tanaka, R., Ishima, Y., Enoki, Y., Kimachi, K., Shirai, T., Watanabe, H., Chuang, V. T., Maruyama, T. and Otagiri, M.

Front Immunol (FRONTIERS RESEARCH FOUNDATION) 5 ( NOV ) 561 2014

Research paper (scientific journal), Joint Work, Accepted, ISSN 1664-3224

Reactive oxygen species (ROS) are the primary pathogenic molecules produced in viral lung infections. We previously reported on the use of a recombinant human serum albumin (HSA)-thioredoxin 1 (Trx) fusion protein (HSA-Trx) for extending the half-life Trx, an endogenous protein with anti-oxidant properties. As a result, it was possible to overcome the unfavorable pharmacokinetic and short pharmacological properties of Trx. We hypothesized that HSA-Trx would attenuate the enhanced ROS production of species such as hydroxyl radicals by neutrophils during an influenza viral infection. The levels of 8-hydroxy-2'-deoxyguanosine and 3-nitrotyrosine were used as indices of the anti-oxidant activity of HSA-Trx. In addition, the cytoprotective effects of HSA-Trx were examined in PR8 (H1N1) influenza virus-induced lung injured mice. The findings show that HSA-Trx reduced the number of total cells, neutrophils, and total protein in BALF of influenza virus-induced lung injured mice. The HSA-Trx treatment significantly decreased the level of 8-hydroxy-2'-deoxyguanosine and 3-nitrotyrosine, but failed to inhibit inducible nitric oxide synthase expression, in the lungs of the virus-infected mice. On the other hand, Tamiflu((R)) treatment also significantly suppressed the production of inflammatory cells and neutrophil infiltration, as well as the protein level in BALF and lung histopathological alterations caused by the influenza virus. The suppressive effect of Tamiflu((R)) was slightly stronger than that of HSA-Trx. Interestingly, Tamiflu((R)) significantly decreased virus proliferation, while HSA-Trx had no effect. These results indicate that HSA-Trx may be of therapeutic value for the treatment of various acute inflammatory disorders such as influenza-virus-induced pneumonia, by inhibiting inflammatory-cell responses and suppressing the overproduction of NO in the lung.

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