Search

Background: Proton pump inhibitors (PPIs) are widely used for the treatment of gastrointestinal disorders such as peptic ulcer disease and dyspepsia. However, several studies have suggested that PPI use increases the risk of acute kidney injury (AKI). PPIs are often concomitantly used with antibiotics, such as macrolides and penicillins for Helicobacter pylori eradication. Although macrolide antibiotics are considered to have relatively low nephrotoxicity, they are well known to increase the risk of AKI due to drug-drug interactions. In this study, we aimed to investigate the association between PPI use and the development of AKI. We also evaluated the effect of concomitant use of PPIs and macrolide antibiotics on the risk of AKI. Methods: This self-controlled case series study was conducted using electronic medical records at Kyoto University Hospital. We identified patients who were prescribed at least one PPI and macrolide antibiotic between January 2014 and December 2019 and underwent blood examinations at least once a year. An adjusted incident rate ratio (aIRR) of AKI with PPI use or concomitant use macrolide antibiotics with PPIs was estimated using a conditional Poisson regression model controlled for the estimated glomerular filtration rate at the beginning of observation and use of potentially nephrotoxic antibiotics. Results: Of the 3, 685 individuals who received PPIs and macrolide antibiotics, 766 patients with episodes of stage 1 or higher AKI were identified. Any stage of AKI was associated with PPI use (aIRR, 1.80 (95% confidence interval (CI) 1.60 to 2.04)). Stage 2 or higher AKI was observed in 279 cases, with an estimated aIRR of 2.01 (95% CI 1.57 to 2.58, for PPI use). For the period of concomitant use of macrolide antibiotics with PPIs compared with the period of PPIs alone, an aIRR of stage 1 or higher AKI was estimated as 0.82 (95% CI 0.60 to 1.13). Conclusions: Our findings added epidemiological information for the association between PPI use

Everolimus has recently been used to prevent graft rejection in liver transplantation and reduces the incidence of kidney dysfunction caused by calcineurin inhibitors. In this study, a population pharmacokinetic analysis was conducted to improve the individualization of everolimus therapy. Japanese post-liver transplant patients whose blood everolimus concentrations were measured between March 2018 and December 2020 were included in this study. A nonlinear mixed-effect modeling program was used to explore covariates that affect everolimus pharmacokinetics. Individual everolimus pharmacokinetic parameters estimated by the post-hoc Bayesian analysis using the final model were compared with the tacrolimus dose per trough concentration (D/C) ratio in each patient. The final model was extrapolated to pediatric liver transplant patients for external evaluation. A total of 937 concentrations from 87 adult patients were used in the model-building process. Everolimus clearance was significantly affected by the estimated glomerular filtration rate, concomitant use of fluconazole, sex, as well as total daily dose of everolimus (TDM effect). The estimated individual apparent clearance of everolimus by the post-hoc Bayesian analysis was moderately correlated with the D/C ratio of tacrolimus in each patient (R² = 0.330, p < 0.0001). The estimation accuracy in pediatric patients was considerably high, except for one infant out of 13 patients. In conclusion, population pharmacokinetic analysis clarified several significant covariates for everolimus pharmacokinetics in liver transplant patients. Everolimus pharmacokinetics moderately correlated with tacrolimus pharmacokinetics and could be extrapolated from adult to pediatric patients by body size correction, except for infants.

Infliximab (IFX) has contributed to the treatment of several chronic inflammatory diseases, including Crohn's disease (CD), ulcerative colitis (UC), psoriasis (Pso), and rheumatoid arthritis (RA). However, the loss of response in some patients with long-term IFX therapy has been a major problem. Randomized controlled trials (RCTs) are limited in their short duration and lack of generalizability to the real-world population. We aimed to describe the persistence rates of IFX therapy to estimate its long-term effectiveness in clinical practice. Claims data from the Japan Medical Data Center database from January 2005 to June 2017 were used. The study population was identified based on the International Classification of Diseases, 10th Revision and the Anatomical Therapeutic Chemical Classification System. The 5-year persistence rates of IFX therapy were estimated using the Kaplan-Meier method. Overall, 281, 235, 41, and 222 patients with CD, UC, Pso, and RA, respectively, were selected. The 5-year persistence rates for IFX claims were 62.9, 38.9, 22.1, and 28.1% in patients with CD, UC, Pso, and RA, respectively. Patients with CD and UC administered IFX beyond the median dose had higher persistence rates. In patients with RA, female sex and no prior use of other biologics were associated with longer persistence. In conclusion, IFX persistence rates differed across chronic inflammatory diseases, which did not correspond to the results of the major RCTs. Factors associated with longer IFX persistence were identified in each disease group. Our findings may provide useful information to facilitate the proper use of IFX.

OBJECTIVES: This study aimed to assess whether the combined use of proton pump inhibitors (PPIs) with non-steroidal anti-inflammatory drugs (NSAIDs) or antibiotics (penicillins, macrolides, cephalosporins or fluoroquinolones) was associated with an increased risk of acute kidney injury (AKI). DESIGN: A nested case-control study. SETTING: A health insurance claims database constructed by the Japan Medical Data Center. PARTICIPANTS: Patients were eligible if they were prescribed a PPI, NSAID and antibiotic at least once between January 2005 and June 2017. The patients who were new PPI users and did not have any history of renal diseases before cohort entry were included (n=219 082). The mean age was 45 and 44% were women. INTERVENTIONS: Current use of PPIs, NSAIDs, or antibiotics. PRIMARY OUTCOME MEASURES: Acute kidney injury. RESULTS: During a mean follow-up of 2.4 (SD, 1.7) years, 317 cases of AKI were identified (incidence rate of 6.1/10 000 person-years). The current use of PPIs was associated with a higher risk of AKI compared with past PPI use (unadjusted OR, 4.09; 95% CI, 3.09 to 5.44). The unadjusted ORs of AKI for the current use of PPIs with NSAIDs, cephalosporins and fluoroquinolones, compared with the current use of PPIs alone, were 3.92 (95% CI, 2.40 to 6.52), 2.57 (1.43 to 4.62) and 3.08 (1.50 to 6.38), respectively. The effects of concurrent use of PPIs with NSAIDs, cephalosporins or fluoroquinolones remain significant in the adjusted model. The analyses on absolute risk of AKI confirmed the results from the nested case-control study. CONCLUSIONS: Concomitant use of NSAIDs with PPIs significantly increased the risk for AKI. Moreover, the results suggested that concomitant use of cephalosporins or fluoroquinolones with PPIs was associated with increased risk of incident AKI.

[Background] The standard anticoagulation therapy for patients implanted with left ventricular assist devices (LVADs) includes warfarin therapy. We developed a cloud-based home medical management information-sharing system named as LVAD@home. The LVAD@home system is an application designed to be used on iPad tablet computers. This system enables the sharing of daily information between a patient and care providers in real time. In this study, we reported cases of outpatients with LVADs using this system to manage anticoagulation therapy. [Case presentation] The patient, a man in his 40s with end-stage heart failure owing to non-ischemic dilated cardiomyopathy, underwent LVAD implantation and warfarin was started on postoperative day 1. He started to use LVAD@home to manage warfarin therapy after discharge (postoperative day 47). He sent his data to care providers daily. By using this system, the pharmacist observed his signs of reduced dietary intake 179 days after discharge, and after consulting the physician, told the patient to change the timing of the next measurement earlier than usual. On the next day, the prothrombin time-international normalized ratio increased from 2.0 to 3.0, and thus the dose was decreased by 0.5 mg. Four patients used this system to monitor warfarin therapy from October 2015 to March 2018. In these patients, the time in therapeutic range was 90.1 ± 1.3, which was higher than that observed in previous studies. Additionally, there were no thromboembolic events or bleeding events. [Conclusions] The cloud-based home management system can be applied to share real-time patient information of factors, including dietary intake that interact with warfarin. It can help to improve long-term anticoagulation outcomes in patients implanted with LVAD.

Riboflavin (vitamin B2) plays an important role in cellular growth and function. Riboflavin transporter 2 (RFVT2) is widely expressed in several tissues, especially in the brain and salivary glands, and plays an important role in the tissue disruption of riboflavin. During the last 10 years, mutations in SLC52A2 have been documented in patients with a rare neurological disorder known as Brown-Vialetto-Van Laere syndrome. However, no suitable animal model of this disease has been reported. Here, we aimed to clarify the physiological role of RFVT2 using Slc52a2-mutant mice. The appearance, body weight, and plasma riboflavin concentration of Slc52a2 heterozygous mutant (Slc52a2+/-) mice were similar to those of wild-type (WT) mice. However, intercrossing between Slc52a2+/- mice failed to generate Slc52a2 homozygous mutant (Slc52a2-/-) mice. This suggested that Slc52a2 gene deficiency results in early embryonic lethality. Our findings suggested that RFVT2 is essential for growth and development, and its deletion may influence embryonic survival.

Riboflavin transporter 3 (RFVT3), encoded by the SLC52A3 gene, is important for riboflavin homeostasis in the small intestine, kidney, and placenta. Our previous study demonstrated that Slc52a3 knockout (Slc52a3−/−) mice exhibited neonatal lethality and metabolic disorder due to riboflavin deficiency. Here, we investigated the influence of Slc52a3 gene disruption on brain development using Slc52a3−/− embryos. Slc52a3−/− mice at postnatal day 0 showed hypoplasia of the brain and reduced thickness of cortical layers. At embryonic day 13.5, the formation of Tuj1+ neurons and Tbr2+ intermediate neural progenitors was significantly decreased; no significant difference was observed in the total number and proliferative rate of Pax6+ radial glia. Importantly, the hypoplastic phenotype was rescued upon riboflavin supplementation. Thus, it can be concluded that RFVT3 contributes to riboflavin homeostasis in embryos and that riboflavin itself is required during embryonic development of the cerebral cortex in mice.

Oxaliplatin, a platinum-based chemotherapeutic drug, frequently induces peripheral neuropathy. Accumulating evidences suggest a possible relationship between peripheral vascular impairment and peripheral neuropathy. In this study, we investigated the effects of vasodilators on cumulative peripheral neuropathy induced by repeated injections of oxaliplatin (10 mg/kg) once a week for 8 weeks in mice. Single injections of vasodilators, including a phosphodiesterase type 5 inhibitor tadalafil acutely alleviated oxaliplatin-induced cold hypersensitivity, while tadalafil had no effect on the mechanical hypersensitivity. By contrast, long-term administration of tadalafil (0.1% in chow diets) during the oxaliplatin injection period reduced the oxaliplatin-induced decreases in skin temperature and blood flow without affecting platinum concentrations in blood, sciatic nerves, and dorsal root ganglion. The long-term administration significantly suppressed cold, mechanical, and electrical current hypersensitivities as well as thermal hypoesthesia. Furthermore, it prevented the decreases in sensory nerve conductance velocity and the number of endoneurial microvessels, and axon degeneration in the sciatic nerves. In vitro studies confirmed that tadalafil does not interfere with the cytotoxicity of oxaliplatin against human cancer cell lines. Altogether, these results suggest that improvement of peripheral vascular impairment by tadalafil could alleviate and prevent oxaliplatin-induced peripheral neuropathy.

Purpose: Therapeutic antibodies have heterogeneities in their structures, although its structural alteration in the body is unclear. Here, we analyzed the change of amino acid modifications and carbohydrate chains of rituximab after administration to patients. Methods: Twenty B cell non-Hodgkin’s lymphoma patients who were treated with rituximab for the first time or after more than one year’s abstinence were recruited. Structural analysis of rituximab was carried out at 1 h after administration and at the trough by using liquid chromatography/time-of-flight-mass spectrometry. Plasma rituximab concentration and pharmacodynamic markers were also determined. Results: Of recruited twenty, 3 patients exhibited rapid rituximab clearance. Nine types of carbohydrate chains were detected in rituximab isolated from the blood. The composition ratios in some glycoforms were significantly different between at 1 h after administration and at the trough, although consisted amino acids remained unchanged. The patients with high clearance showed extensive alterations of glycoform composition ratios. However, pharmacodynamics makers were not different. Conclusion: Inter-individual variations in plasma concentrations of rituximab were found in some B-NHL patients. We could analyze a change in glycoforms of rituximab in the patients, and this finding may affect the pharmacokinetics of rituximab.

[Background] Diabetic peripheral neuropathy is a common long-term complication of diabetes. Accumulating evidence suggests that vascular impairment plays important roles in the pathogenesis of diabetic peripheral neuropathy, while the mechanism remains unclear. We recently reported that transient receptor potential ankyrin 1 (TRPA1) is sensitized by hypoxia, which can contribute to cold hypersensitivity. In this study, we investigated the involvement of TRPA1 and vascular impairment in painful diabetic peripheral neuropathy using streptozotocin-induced diabetic model mice. [Results] Streptozotocin-induced diabetic model mice showed mechanical and cold hypersensitivity with a peak at two weeks after the streptozotocin administration, which were likely to be paralleled with the decrease in the skin blood flow of the hindpaw. Streptozotocin-induced cold hypersensitivity was significantly inhibited by an antagonist HC-030031 (100 mg/kg) or deficiency for TRPA1, whereas mechanical hypersensitivity was unaltered. Consistent with these results, the nocifensive behaviors evoked by an intraplantar injection of the TRPA1 agonist allyl isothiocyanate (AITC) were enhanced two weeks after the streptozotocin administration. Both streptozotocin-induced cold hypersensitivity and the enhanced AITC-evoked nocifensive behaviors were significantly inhibited by a vasodilator, tadalafil (10 mg/kg), with recovery of the decreased skin blood flow. Similarly, in a mouse model of hindlimb ischemia induced by the ligation of the external iliac artery, AITC-evoked nocifensive behaviors were significantly enhanced three and seven days after the ischemic operation, whereas mechanical hypersensitivity was unaltered in TRPA1-knockout mice. However, no difference was observed between wild-type and TRPA1-knockout mice in the hyposensitivity for current or mechanical stimulation or the deceased density of intraepidermal nerve fibers eight weeks after the streptozotocin administration. [Conclusion] Th

For the optimum efficacy of disease-modifying anti-rheumatic drugs (DMARDs), patients need to be adherent to their medication regimen. To clarify the effects of medication adherence on disease activity in Japanese patients with rheumatoid arthritis (RA), we conducted a cohort study in patients with various stages of RA. Patients were enrolled from the Kyoto University RA Management Alliance cohort, and followed up prospectively for 12 months. In this study, a total of 475 patients were analyzed and divided into 9 groups according to their medication adherence and the RA disease duration. The primary outcomes were based on the rate of a disease flare. The secondary outcomes were the changes in disease activity score using 28 joints (DAS28-ESR), simplified disease activity index (SDAI) and physical disability by health assessment questionnaire-disability index (HAQ). The changes in DAS28-ESR, HAQ, and the risk of disease flare in the highly adherent patients were significantly lower than those of the less adherent patients among the groups with RA ≤ 4.6 years but not those among the other groups. Taken together, this study identified a significant association between medication adherence and the disease flare during early-stage RA or short disease duration. These results emphasize the need to pay more attention to medication adherence in preventing the disease progression of RA.

Background: Chemotherapy-induced peripheral neuropathy (CIPN) is a dose-limiting and disabling side effect of taxane anticancer agents. We prospectively evaluated the efficacy of cryotherapy for CIPN prevention. Methods: Breast cancer patients treated weekly with paclitaxel (80 mg/m2 for one hour) wore frozen gloves and socks on the dominant side for 90 minutes, including the entire duration of drug infusion. Symptoms on the treated sides were compared with those on the untreated (nondominant) sides. The primary end point was CIPN incidence assessed by changes in tactile sensitivity from pretreatment baseline in a monofilament test at a cumulative dose of 960 mg/m2. We also assessed thermosensory deficits, subjective symptoms (Patient Neuropathy Questionnaire [PNQ]), manipulative dexterity, and the time to events and hazard ratio by PNQ. All statistical tests were two-sided. Results: Among the 40 patients, four did not reach the cumulative dose (due to the occurrence of pneumonia, severe fatigue, severe liver dysfunction, and macular edema), leaving 36 patients for analysis. None dropped out due to cold intolerance. The incidence of objective and subjective CIPN signs was clinically and statistically significantly lower on the intervention side than on the control (hand: tactile sensitivity = 27.8% vs 80.6%, odds ratio [OR] = 20.00, 95% confidence interval [CI] = 3.20 to 828.96, P < .001; foot: tacile sensitivity = 25.0% vs 63.9%, OR = infinite, 95% CI = 3.32 to infinite, P < .001; hand: warm sense = 8.8% vs 32.4%, OR = 9.00, 95% CI = 1.25 to 394.48, P = .02; foot: warm sense: 33.4% vs 57.6%, OR = 5.00, 95% CI = 1.07 to 46.93, P = .04; hand: PNQ = 2.8% vs 41.7%, OR = infinite, 95% CI = 3.32 to infinite, P < .001; foot: PNQ = 2.8% vs 36.1%, OR = infinite, 95% CI = 2.78 to infinite, P < .001; hand: hazard ratio [HR] = 0.13, 95% CI = 0.05 to 0.34; foot: HR = 0.13, 95% CI = 0.04 to 0.38, dexterity mean delay = −2.5 seconds, SD = 12.0 seconds, vs + 8.6 seconds, SD = 25.8

Therapeutic monoclonal antibodies (mAbs) have heterogeneities in their structures. Multiple studies have reported that the variety of post-translational modifications could affect the pharmacokinetic profiles or pharmacological potencies of therapeutic mAbs. Taking into the account that the structural modification of mAbs would affect the efficacy, it is worth investigating the structural alteration of therapeutic mAbs in the blood and the relationship between their structures and pharmacological effects. Herein, we have developed the method to isolate rituximab from plasma in which endogenous IgGs interfere the detection of rituximab, and successfully developed the analytical method with a liquid chromatograph time-of-flight mass spectrometer to detect the structure of rituximab in plasma with errors less than 30 parts per millions. Eight types of carbohydrate chains in rituximab were detected by this method. Interestingly, time-dependent changes in carbohydrate chains such as AAF (G2F) and GnGn (G0) were observed in rats, although the amino acids were stable. Additionally, these structural changes were observed via incubation in plasma as in the rat experiment, suggesting that a certain type of enzyme in plasma caused the alterations of the carbohydrate chains. The present analytical methods could clarify the actual pharmacokinetics of therapeutic mAbs, and help to evaluate the interindividual variations in pharmacokinetics and efficacy.

Riboflavin (vitamin B2) plays a role in various biochemical oxidation-reduction reactions. Flavin mononucleotide (FMN) and FAD, the biologically active forms, are made from riboflavin. Riboflavin transporters (RFVTs), RFVT1-3/Slc52a1-3, have been identified. However, the roles of human (h)RFVTs in FMN and FAD homeostasis have not yet been fully clarified. In this study, we assessed the contribution of each hRFVT to riboflavin, FMN and FAD uptake and efflux using in vitro studies. The transfection of hRFVTs increased cellular riboflavin concentrations. The uptake of riboflavin by human embryonic kidney cells transfected with hRFVTs was significantly increased, and the efflux was accelerated in a time-dependent manner. However, the uptake and efflux of FMN and FAD hardly changed. These results strongly suggest that riboflavin, rather than FMN or FAD, passes through plasma membranes via hRFVTs. Our findings could suggest that hRFVTs are involved in riboflavin homeostasis in the cells, and that FMN and FAD concentrations are regulated by riboflavin kinase and FAD synthase.

Homeostasis of riboflavin should be maintained by transporters. Previous in vitro studies have elucidated basic information about riboflavin transporter RFVT3 encoded by SLC52A3 gene. However, the contribution of RFVT3 to the maintenance of riboflavin homeostasis and the significance in vivo remain unclear. Here, we investigated the physiological role of RFVT3 using Slc52a3 knockout (Slc52a3−/−) mice. Most Slc52a3−/− mice died with hyperlipidemia and hypoglycemia within 48 hr after birth. The plasma and tissue riboflavin concentrations in Slc52a3−/− mice at postnatal day 0 were dramatically lower than those in wild-type (WT) littermates. Slc52a3−/− fetuses showed a lower capacity of placental riboflavin transport compared with WT fetuses. Riboflavin supplement during pregnancy and after birth reduced neonatal death and metabolic disorders. To our knowledge, this is the first report to indicate that Rfvt3 contributes to placental riboflavin transport, and that disruption of Slc52a3 gene caused neonatal mortality with hyperlipidemia and hypoglycemia owing to riboflavin deficiency.

Dysesthesia is an unpleasant abnormal sensation, which is often accompanied by peripheral neuropathy or vascular impairment. Here, we examined the roles of transient receptor potential ankyrin 1 (TRPA1) in dysesthesia-like behaviours elicited by transient hindlimb ischemia (15–60 min) by tightly compressing the hindlimb, and reperfusion by releasing the ligature. The paw-withdrawal responses to tactile stimulation were reduced during ischemia and lasted for a while after reperfusion. Hindlimb ischemia/reperfusion elicited spontaneous licking of the ischemic hindpaw that peaked within 10 min. The licking was inhibited by reactive oxygen species (ROS) scavengers, a TRPA1 antagonist, or TRPA1 deficiency, but not by TRPV1 deficiency. In human TRPA1-expressing cells as well as cultured mouse dorsal root ganglion neurons, the H[2]O[2]-evoked TRPA1 response was significantly increased by pretreatment with hypoxia (80 mmHg) for 30 min. This hypoxia-induced TRPA1 sensitisation to H[2]O[2] was inhibited by overexpressing a catalytically-inactive mutant of prolyl hydroxylase (PHD) 2 or in a TRPA1 proline mutant resistant to PHDs. Consistent with these results, a PHD inhibitor increased H[2]O[2]-evoked nocifensive behaviours through TRPA1 activation. Our results suggest that transient hindlimb ischemia/reperfusion-evoked spontaneous licking, i.e. painful dysesthesia, is caused by ROS-evoked activation of TRPA1 sensitised by hypoxia through inhibiting PHD-mediated hydroxylation of a proline residue in TRPA1.

publisher, 東京, 学会講演要旨

Coarticuration of a sequence of vowels is normalized by a linear model of the coarticulation. An auditory response of V_0 in V V_0 V type connected vowels is modeled as a linear function of the acoustical features of the preceeding V, V_0, and the following V. The coefficients of the function are determined by the method of least squares using training data. The error rate of the recognition test using the model is lower by 7.5% than that of the test not using the model.