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

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.

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

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.

Qualitative and quantitative status of cytochrome P450s after the administration of a liposomal platelet substitute in rat liver.

In the process of the drug development, studies on the cytochrome P450 (CYP) profiles after its administration provided fundamental information regarding drug interactions with concomitantly administered drugs. Here, we evaluated the influence of the administration of H12-(ADP)-liposomes, a platelet substitute, on the mRNA and protein expression, and metabolic activity of CYPs, with focus on the CYP1A2, CYP2C11 and CYP3A2, in rat liver.At 24 h after administering saline or H12-(ADP)-liposomes (10 mg of lipids/kg), a quantitative RT-PCR and western blot analysis revealed that the mRNA and proteins expression of all of the target hepatic CYP isoforms were not different between the saline and H12-(ADP)-liposome groups. Furthermore, an ex vivo CYP metabolic activity assay showed that hepatic CYP metabolic activities in the H12-(ADP)-liposome group were comparable to the corresponding saline group. On the other hand, the area under the blood concentration-time curve for substitutes for CYP1A2 and CYP2C11 was higher in H12-(ADP)-liposome group than in saline group, but the degree of elevations was negligible levels.At a minimum, based on these results, we conclude that H12-(ADP)-liposomes have no quantitative and qualitative effect on the hepatic CYP isoforms, indicating that the drug interactions of H12-(ADP)-liposomes with CYP-metabolizing drugs would be negligible.

Carbon monoxide-loaded red blood cells ameliorate metabolic dysfunction-associated steatohepatitis progression via enhancing AMP-activated protein kinase activity and inhibiting Kupffer cell activation.

Metabolic dysfunction-associated steatohepatitis (MASH) is a progressive form of nonalcoholic fatty liver disease characterised by fat accumulation, inflammation, oxidative stress, fibrosis, and impaired liver regeneration. In this study, we found that heme oxygenase-1 (HO-1) is induced in both MASH patients and in a MASH mouse model. Further, hepatic carbon monoxide (CO) levels in MASH model mice were >2-fold higher than in healthy mice, suggesting that liver HO-1 is activated as MASH progresses. Based on these findings, we used CO-loaded red blood cells (CO-RBCs) as a CO donor in the liver, and evaluated their therapeutic effect in methionine-choline deficient diet (MCDD)-induced and high-fat-diet (HFD)-induced MASH model mice. Intravenously administered CO-RBCs effectively delivered CO to the MASH liver, where they prevented fat accumulation by promoting fatty acid oxidation via AMP-activated protein kinase (AMPK) activation and peroxisome proliferator-activated receptor induction. They also markedly suppressed Kupffer cell activation and their corresponding anti-inflammatory and antioxidative stress activities in MASH mice. CO-RBCs also helped to restore liver regeneration in mice with HFD-induced MASH by activating AMPK. We confirmed the underlying mechanisms by performing in vitro experiments in RAW264.7 cells and palmitate-stimulated HepG2 cells. Taken together, CO-RBCs show potential as a promising cellular treatment for MASH.

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

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.

Predictive Value of Vancomycin AUC24/MIC Ratio for 30-day Mortality in Patients with Severe or Complicated Methicillin-Resistant Staphylococcus aureus Infections: A Multicenter Retrospective Study.

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.

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

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.

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

We aimed to assess the frequency of acute kidney injury (AKI) in different areas 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 classified into 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% confidence interval (CI) 1.64-17.63] and the AUC24-48h ≥600 µg·h/mL (hazard ratio 7.0, 95% CI 2.31-21.18) significantly correlated with a higher incidence of AKI compared with the AUC24-48h <500 µg·h/mL. In conclusion, we identified an 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. IMPORTANCE: Vancomycin (VAN) is a glycopeptide antibiotic and one of the most commonly used antibiotics for severe infections caused by methicillin-resistant Staphylococcus aureus. However, higher VAN concentrations have been associated with an increased risk of acute kidney injury (AKI). Herein, we aimed to assess the frequency of AKI in different areas under the concentration-time curve (AUC) values of VAN using a two-point blood collection method, allowing for accurate AUC assessment in critically ill patients. We identified an association between AUC on day 2 and the risk of AKI in intensive care unit 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. Therefore, individualized dosing is feasible, with pharmacists being able to optimize VAN doses to attain appropriate targets.

Carbon Monoxide Alleviates Post-ischemia-reperfusion Skeletal Muscle Injury and Systemic Inflammation.

Restoration of blood flow in skeletal muscle after a prolonged period of ischemia induces muscular ischemia-reperfusion injury, leading to local injury/dysfunction in muscles followed by systemic inflammatory responses. However, preventive/curative agents for skeletal muscle ischemia injury are unavailable in clinics to date. Increasing evidence has validated that carbon monoxide (CO) prevents the progression of ischemia-reperfusion injury in various organs owing to its versatile bioactivity. Previously, we developed a bioinspired CO donor, CO-bound red blood cells (CO-RBC), which mimics the dynamics of RBC-associated CO in the body. In the present study, we have tested the therapeutic potential of CO-RBC in muscular injury/dysfunction and secondary systemic inflammation induced by skeletal muscle ischemia-reperfusion. The results indicate that CO-RBC rather than RBC alone suppressed elevation of plasma creatine phosphokinase, a marker of muscular injury, in rats subjected to both hind limbs ischemia-reperfusion. In addition, the results of the treadmill walking test revealed a significantly decreased muscular motor function in RBC-treated rats subjected to both hind limbs ischemia-reperfusion than that in healthy rats, however, CO-RBC treatment facilitated sustained muscular motor functions after hind limbs ischemia-reperfusion. Furthermore, CO-RBC rather than RBC suppressed the production of tumour necrosis factor (TNF)-α and interleukin (IL)-6, which were upregulated by muscular ischemia-reperfusion. Interestingly, CO-RBC treatment induced higher levels of IL-10 compared to saline or RBC treatments. Based on these findings, we suggest that CO-RBC exhibits a suppressive effect against skeletal muscle injury/dysfunction and systemic inflammatory responses after skeletal muscle ischemia-reperfusion.

Carbon monoxide-loaded cell therapy as an exercise mimetic for sarcopenia treatment.

Sarcopenia is characterized by loss of muscle strength and muscle mass with aging. The growing number of sarcopenia patients as a result of the aging population has no viable treatment. Exercise maintains muscle strength and mass by increasing peroxisome growth factor activating receptor γ-conjugating factor-1α (PGC-1α) and Akt signaling in skeletal muscle. The present study focused on the carbon monoxide (CO), endogenous activator of PGC-1α and Akt, and investigated the therapeutic potential of CO-loaded red blood cells (CO-RBCs), which is bioinspired from in vivo CO delivery system, as an exercise mimetic for the treatment of sarcopenia. Treatment of C2C12 myoblasts with the CO-donor increased the protein levels of PGC-1α which enhanced mitochondrial biogenesis and energy production. The CO-donor treatment also activated Akt, indicating that CO promotes muscle synthesis. CO levels were significantly elevated in the skeletal muscle of normal mice after intravenous administration of CO-RBCs. Furthermore, CO-RBCs restored the mRNA expression levels of PGC-1α in the skeletal muscle of two experimental sarcopenia mouse models, denervated (Den) and hindlimb unloading (HU) models. CO-RBCs also restored muscle mass in Den mice by activating Akt signaling and suppressing the muscle atrophy factors myostatin and atrogin-1, and oxidative stress. Treadmill tests further showed that the reduced running distance in HU mice was significantly restored by CO-RBC administration. These findings suggest that CO-RBCs have potential as an exercise mimetic for sarcopenia treatment.

Preparation and in Vitro Characterization of Fatty-Acid Modified Pirarubicin Nanosuspensions Stabilized by Albumin.

Pirarubicin (THP) shows more rapid intracellular uptake, more effective antitumor activity, and less cardiac toxicity, compared to doxorubicin. However, THP is distributed to both tumor and normal tissues indiscriminately. This study aimed to develop a nanosuspension to deliver THP to tumor tissues more efficiently. Fatty-acid-modified THPs (FA-THPs; octanoic acid, dodecanoic acid, palmitic acid-THPs) were synthesized to increase the hydrophobicity of THP. Nanosuspensions of these FA-THPs were then prepared using an antisolvent precipitation technique. Among the FA-THPs, the most efficiently drug-loaded nanosuspension was obtained from palmitic acid-THP (pal-THP) using an aqueous antisolvent containing bovine serum albumin as a stabilizer. The pal-THP nanoparticles in the nanosuspension were confirmed to be of optimal size (100-125 nm) for delivery to tumor tissues using dynamic light scattering and transmission electron microscopy. The pal-THP nanosuspension showed cytotoxicity in colon 26 cells. The nanosuspension was shown to disintegrate in the presence of surfactants such as lecithin, liberating pal-THP, which was converted to free THP in acidic media. It is therefore proposed that pal-THP nanoparticles that reach tumor cells after intravenous administration would exert antitumor effect by liberating pal-THP (i.e., disintegration of nanoparticles by the interaction with cell membrane), followed by the release of free THP in the acidic milieu of tumor cells. These findings indicate that FA-THP nanosuspensions, particularly pal-THP nanosuspension, hold promise as a candidate for cancer treatment. However, further in vivo studies are necessary.

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

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.

Polyoxazoline-Conjugated l-Asparaginase: An Antibody-Production-Free Therapeutic Agent for Acute Lymphoblastic Leukemia.

l-asparaginase (ASNase), an enzyme that catalyzes the hydrolysis of l-asparagine into l-aspartic acid, is frequently used as a medication for acute lymphoblastic leukemia (ALL). However, when derived from bacterial sources, this enzyme can elicit side effects, including allergic or hypersensitivity reactions, owing to immune responses. Here, we describe the synthesis of polyoxazoline-conjugated ASNase (POx-ASNase) and investigate its enzyme activity, anticancer efficacy, immunogenicity, and retention in the bloodstream. The water-soluble POx was coupled with surface lysine residues of ASNase using a bifunctional cross-linker. The average number of polymers bound to each enzyme was determined as 10. Although the enzymatic activity of POx-ASNase decreased to 56% of that of native ASNase, its temperature and pH dependencies remained unaltered. Remarkably, the lyophilized powder form of POx-ASNase retained its catalytic ability for 24 months. POx-ASNase demonstrated nearly identical anticancer efficacy compared to naked ASNase against leukemia and lymphoma cells (MOLT-4, CLBL-1, and K562) while displaying no cytotoxicity toward normal cells. Animal experiments conducted using rats revealed that the POx decoration suppressed the generation of anti-ASNase IgM and IgG antibodies with no detection of anti-POx antibodies. The half-life within the bloodstream extended to 34 h, representing a 17-fold increase compared to unmodified ASNase. These findings suggest that POx-ASNase serves as an anticancer therapeutic agent, characterized by the absence of antibody production and notably extended circulation persistence.

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

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.

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

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.

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

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.

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

PURPOSE: Nacubactam (NAC) is a novel diazabicyclooctane ß-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 ß-lactamase-producing Enterobacterales, such as the carbapenemase-producing Enterobacterales. METHODS: Three strains of ß-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 ß-lactamase-producing Enterobacterales is 30%.

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

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-ß (TGF-ß), 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-ß levels. In agreement with the results of in vivo experiments, co-stimulation with IS, TGF-ß, 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.

Carbon Monoxide-Loaded Red Blood Cell Prevents the Onset of Cisplatin-Induced Acute Kidney Injury.

Cisplatin-induced acute kidney injury (AKI) is an important factor that limits the clinical use of this drug for the treatment of malignancies. Oxidative stress and inflammation are considered to be the main causes of not only cisplatin-induced death of cancer cells but also cisplatin-induced AKI. Therefore, developing agents that exert antioxidant and anti-inflammatory effects without weakening the anti-tumor effects of cisplatin is highly desirable. Carbon monoxide (CO) has recently attracted interest due to its antioxidant, anti-inflammatory, and anti-tumor properties. Herein, we report that CO-loaded red blood cell (CO-RBC) exerts renoprotective effects on cisplatin-induced AKI. Cisplatin treatment was found to reduce cell viability in proximal tubular cells via oxidative stress and inflammation. Cisplatin-induced cytotoxicity, however, was suppressed by the CO-RBC treatment. The intraperitoneal administration of cisplatin caused an elevation in the blood urea nitrogen and serum creatinine levels. The administration of CO-RBC significantly suppressed these elevations. Furthermore, the administration of CO-RBC also reduced the deterioration of renal histology and tubular cell injury through its antioxidant and anti-inflammatory effects in cisplatin-induced AKI mice. Thus, our data suggest that CO-RBC has the potential to substantially prevent the onset of cisplatin-induced AKI, which, in turn, may improve the usefulness of cisplatin-based chemotherapy.

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

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.