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Phytic acid, a constituent of various plants, has been related to health benefits. Phytic acid has been shown to inhibit purine nucleotide metabolism in vitro and suppress elevation of plasma uric acid levels after purine administration in animal models. This study investigated the effect of phytic acid on postprandial serum uric acid (SUA) in humans. This randomized, double-blind, crossover design study included 48 healthy subjects with normal fasting SUA. Subjects consumed a control drink and a phytic acid drink with purine-rich food, and serum and urine uric acid levels were measured for 360 min after purine loading. Phytic acid lowered the incremental area under the curve (0–360 min) and incremental maximum concentration of SUA after purine loading (p < 0.05); tended to lower cumulative urinary uric acid excretion (0–360 min) after purine loading (p < 0.10); and suppressed postprandial SUA in this clinical study. Altogether, our findings suggest that phytic acid may play a beneficial role in controlling postprandial SUA. [ABSTRACT FROM AUTHOR]

Background: Numerous chemical reprogramming techniques have been reported, rendering them applicable to regenerative medicine research. The aim of our study was to evaluate the therapeutic potential of human CLiP derived from clinical specimens transplanted into a nonalcoholic steatohepatitis (NASH) mouse model of liver fibrosis., Methods: We successfully generated chemically induced liver progenitor (CLiP), which exhibited progenitor-like characteristics, through stimulation with low-molecular-weight compounds. We elucidated their cell differentiation ability and therapeutic effects. However, the therapeutic efficacy of human CLiP generated from clinical samples on liver fibrosis, such as liver cirrhosis, remains unproven., Results: Following a 4 week period, transplanted human CLiP in the NASH model differentiated into mature hepatocytes and demonstrated suppressive effects on liver injury markers (i.e., aspartate transaminase and alanine transaminase). Although genes related to inflammation and fat deposition did not change in the human CLiP transplantation group, liver fibrosis-related factors (Acta2 and Col1A1) showed suppressive effects on gene expression following transplantation, with approximately a 60% reduction in collagen fibers. Importantly, human CLiP could be efficiently induced from hepatocytes isolated from the cirrhotic liver, underscoring the feasibility of using autologous hepatocytes to produce human CLiP., Conclusion: Our findings demonstrate the effectiveness of human CLiP transplantation as a viable cellular therapy for liver fibrosis, including NASH liver. These results hold promise for the development of liver antifibrosis therapy utilizing human CLiP within the field of liver regenerative medicine., (© 2024 Japanese Society of Hepato‐Biliary‐Pancreatic Surgery.)

Portal vein embolization (PVE) is recommended as a preoperative procedure for patients with biliary tract cancer scheduled to undergo hepatic resection of more than 50%-60% of the liver. However, details and/or information regarding the follow-up of unresectable cases are often lacking, and the clinical course of unresectable cases is not well analyzed and reported. This study aimed to clarify the clinical prognosis of patients with unresectable biliary tract cancer after PVE. We retrospectively analyzed the clinical backgrounds of patients with biliary tract cancer who underwent PVE without subsequent resection between January 2011 and October 2022. Of the 21 patients with biliary tract cancer who underwent PVE during the study period, eight (38%) cases were unsuitable for resection after PVE for the following reasons: intraoperatively detected dissemination (n=2), para-aortic lymph node metastasis (n=1), liver metastasis (n=1), decreased liver function (n=2), development of liver metastasis while waiting (n=1), and insufficient residual liver volume (n=1). All patients received subsequent chemotherapy, including gemcitabine plus S-1 therapy in three cases, gemcitabine plus cisplatin plus S-1 in three cases, and gemcitabine plus cisplatin or S-1+cisplatin in one case each. As there is currently no curative treatment for biliary tract cancer other than surgery, multidisciplinary management and treatment of patient factors, including tumor factors and liver function, are essential to reducing the number of unresectable cases after PVE.

This report describes a case of BRAF V600E-mutated colorectal cancer with CNS metastases in which treatment with encorafenib, binimetinib and cetuximab was effective. There is limited information on the ability of encorafenib, binimetinib and cetuximab to enter the CNS.The patient was a 53-year-old man was diagnosed with ascending colon cancer (cT3N3M1c stage IVc). BRAF V600E mutation was confirmed. FOLFOX was started, but CNS metastases soon appeared. Encorafenib, binimetinib and cetuximab were administered and had a favorable effect on the CNS lesions. The patient initially responded well, but his disease progressed 2 months later. Further research is needed to improve management strategies for BRAF V600E-mutated colorectal cancer with CNS metastases.

Background: We previously reported the successful development of a computer-aided diagnosis (CAD) system for preventing retained surgical sponges with deep learning using training data, including composite and simulated radiographs. In this study, we evaluated the efficacy of the CAD system in a clinical setting., Study Design: A total of 1,053 postoperative radiographs obtained from patients 20 years of age or older who underwent surgery were evaluated. We implemented a foreign object detection application software on the portable radiographic device used in the operating room to detect retained surgical sponges. The results of the CAD system diagnosis were prospectively collected., Results: Among the 1,053 images, the CAD system detected possible retained surgical items in 150 images. Specificity was 85.8%, which is similar to the data obtained during the development of the software., Conclusions: The validation of a CAD system using deep learning in a clinical setting showed similar efficacy as during the development of the system. These results suggest that the CAD system can contribute to the establishment of a more effective protocol than the current standard practice for preventing the retention of surgical items., (Copyright © 2024 by the American College of Surgeons. Published by Wolters Kluwer Health, Inc. All rights reserved.)

Background: A decrease in the regenerative capacity of age-damaged liver tissue has been reported. Liver progenitor cells may play an important role in the regeneration of injured livers. In the present study we aimed to investigate improvements in the regenerative capacity of age-damaged livers using chemically induced liver progenitors (CLiPs) derived from mature hepatocytes., Methods: Old (>90 weeks) and young (<20 weeks) mice underwent 70% hepatectomy, with or without trans-splenic CLiP administration. The residual liver/bodyweight (LW/BW) ratio was measured on postoperative days 1 and 7, and changes in liver regeneration and histology were evaluated., Results: At 7 days post-hepatectomy, LW/BW ratios were significantly better in CLiP-treated old mice than in untreated old mice (p = .02). By contrast, no effect of CLiP transplantation was observed in young mice (p = .62). Immunofluorescence staining of liver tissue after CLiP administration showed an increase in Ki67-positive cells (p < .01). Flow cytometry analysis of green fluorescent protein-labeled CLiPs indicated that transplanted CLiPs differentiated into mature hepatocytes and were present in the recipient liver., Conclusions: CLiP transplantation appears to ameliorate the age-related decline in liver regeneration in mice., (© 2024 Japanese Society of Hepato‐Biliary‐Pancreatic Surgery.)

Background: Recently, the successful delivery of organs for transplantation using drones was reported. We investigated the influence of transportation by drones on the quality of liver grafts using a rat model., Methods: Livers of 12 rats (8 and 32 weeks old) were divided into 2 groups of six. Livers were split into 2 parts and allocated to the drone or control groups (both n = 12). The drone experiment was conducted between islands in Nagasaki Prefecture, Japan. The distance between the islands was 12 km. Livers of the drone group were transported by a multicopter at a speed of 30 km-40 km/h over 60 m above sea level. Transported liver quality was analyzed by histology, and biochemistry data were compared between groups., Results: Cold ischemia time did not differ between groups (902 min and 909 min, respectively). There were no differences in macroscopic findings regarding coloration and damage between groups. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) in preservation fluid were graft weight-corrected and compared, and no significant differences were found between groups: AST/g (4.61 vs 4.81 IU/L), ALT/g (2.78 vs 2.92 IU/L), and ALP/g (39.1 vs 37.0 IU/L). Immunochemical staining showed no significant difference between groups for terminal deoxynucleotidyl transferase dUTP nick and labeling staining (141 vs 113 cells), CD163 (818 vs 870 cells), and TNF-α (1.25 vs 1.41 scores)., Conclusions: The simulation experiment of organ transport for transplantation by drones was successfully conducted. There were no differences in the quality of livers transported by drones or other means. Further studies including large-animal experiments could lead to future clinical applications., Competing Interests: Declaration of Competing Interest All the authors declare no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Portal vein thrombosis following liver transplantation is generally managed by endovascular treatment. Although several techniques are available for portal venous access, trans-splenic access is of interest because it avoids damage to the liver graft. However, the spleen cannot be punctured to access the portal vein after splenectomy. We herein report a case of portal vein thrombosis following living donor liver transplantation with simultaneous splenectomy successfully treated by percutaneous intervention with direct puncture of the retropancreatic splenic vein. The splenic vein was punctured under computed tomography guidance in the prone position. Portal venography revealed a contrast defect due to a thrombus in the extrahepatic to intrahepatic portal vein. The portal vein was reopened after thrombectomy, and the portal vein thrombosis did not recur for 2 y. The technique and advantages of our approach are described., Competing Interests: The authors declare no funding or conflicts of interest., (Copyright © 2022 The Author(s). Transplantation Direct. Published by Wolters Kluwer Health, Inc.)

Chemically-induced liver progenitors (CLiPs) have promising applications in liver regenerative medicine. We aimed to clarify the efficacy of CLiPs for ameliorating fibrosis in a diet-induced nonalcoholic steatohepatitis rat model, since nonalcoholic fatty liver disease is currently recognized as the most common form of chronic liver disease in developed countries., Methods: Primary mature hepatocytes were isolated from 7-week-old male Wistar rats. To establish CLiPs, isolated hepatocytes were cultured in differentiation medium composed of Y-27632, A-83-01, and CHIR99021 (YAC medium). As an animal model that reproduces NASH pathophysiology, 6-week-old severe combined immunodeficient (SCID) mice were carefully selected and prepared and fed with choline-deficient, L-amino acid-defined, high-fat diet (HFD). After 12 weeks' HFD feeding, the mice were assigned to continue HFD with or without the administration of rat CLiPs (HFD + CLiPs and HFD-CLiPs, respectively). Rat CLiPs were administered from the spleen. Hepatic fibrosis was semi-quantitatively evaluated according to histology. Liver parenchyma and blood samples were collected for biochemical analyses., Results: Rat CLiPs were positive for CK19 and EpCAM were successfully delivered to the liver. At 8 weeks after CLiPs transplantation, the HFD + CLiPs group showed significantly less positive staining than the HFD-CLiPs group. Alanine aminotransferase significantly improved in the HFD + CLiPs group, as demonstrated by Azan staining and αSMA immunostaining. RT qPCR showed that the liver expression of MMP2 and 9 tended to be higher in the HFD + CLiPs group., Conclusions: The anti-fibrotic effect of CLiPs was demonstrated in the immunodeficient NASH animal model and may have therapeutic applications in humans., Competing Interests: The authors declare no conflicts of interest in association with the present study., (© 2022 The Japanese Society for Regenerative Medicine. Production and hosting by Elsevier B.V.)

Purpose: Acoustic radiation force impulse (ARFI) elastography is widely used for evaluating liver fibrosis. Here we evaluated the efficacy of ARFI elastography for estimating graft quality and clinical outcomes in living donor liver transplant (LDLT)., Methods: We retrospectively evaluated the cases of 87 LDLT donors who preoperatively underwent ARFI elastography at Nagasaki University Hospital between August 2010 and June 2016. We analyzed whether the velocity of shear wave (Vs) obtained by ARFI elastography affected the regeneration rate of each donor's remnant liver and the 1-year survival rate of the recipients., Results: There were no significant correlations between Vs value and the donors' age. Only 1 donor (1.1%) showed significant fibrosis, F2 (portal fibrosis with few septa) in zero-biopsy. The 7 donors (8.0%), including 1 case, showed a high Vs value (> 1.33) that was equal to F2, although there was no abnormal pathologic finding except in 1 case. In those cases, the regeneration rate of the remnant liver after hepatectomy was significantly lower compared to other cases. The 1-year survival rate of the recipients paired with the high-Vs donors was also significantly poorer than that of the other cases (high-Vs: 57.1%, others: 84.2%, P = .04)., Conclusions: ARFI elastography might be an effective examination for the preoperative evaluation of the graft quality in LDLT., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: In laparoscopic liver resection, few reports have investigated the influence of type of incision on postoperative pain in laparoscopic liver resection. We therefore conducted the present study to clarify the difference in postoperative pain between two types of incision., Methods: Nineteen patients who underwent laparoscopic lateral sectionectomy were enrolled. In 11 patients with a transumbilical incision and eight with a suprapubic incision, the operation duration, blood loss, length of incision, duration of intravenous fentanyl infusion immediately after surgery and rescue dosage, and period of regular oral nonsteroidal anti-inflammatory drugs were evaluated., Results: There was no significant difference between the two groups in patients' background characteristics, operation time, or amount of blood loss. The length of suprapubic incision was significantly longer than the umbilical incision. Concerning the postoperative pain management, the duration of intravenous fentanyl administration was 1 day (1-2 days) for umbilical incisions and 1.5 days (1-2 days) for suprapubic incisions, showing no significant difference. Regarding the rescue dosage of fentanyl, the results were comparable between the groups. Regarding the postoperative duration of regular nonsteroidal anti-inflammatory drug administration, there was also no significant difference between the groups (transumbilical: 14 [5-35] days vs suprapubic: 8 [7-32])., Conclusions: Postoperative pain is comparable between umbilical and suprapubic incision in patients who underwent laparoscopic left lateral segmentectomy. In terms of postoperative pain, either a transumbilical incision or a suprapubic incision can be selected for specimen extraction., (© 2022 Asia Endosurgery Task Force and Japan Society of Endoscopic Surgery and John Wiley & Sons Australia, Ltd.)

Background/aim: Easy measurement of liver steatosis without pathological diagnosis may help improve donor surgery efficiency and increase the chances of organ donations. We analyzed the correlations between bioelectrical impedance (BI) in human livers, liver fat content, and pathological findings., Materials and Methods: Sixteen tumor-free liver specimens resected during elective oncological surgery were analyzed. All samples were stored in ice chilled saline before BI measurement. The BI measurement was performed using a device with the tetrapolar circuit method in which the current and voltage electrodes are independent. Liver cholesterol and triglyceride levels were investigated from the same specimen using the Soxhlet extraction method. Pathological findings were examined by counting the number of hepatocytes with fatty changes per high-power field., Results: The median liver steatosis percentage was 0.4%. The liver steatosis percentage was significantly correlated with the intrahepatic triglyceride content (r=0.82, p<0.001). Linear regression of the measurements and predicted values yielded an r 2 of 0.63 between the BI at 100 kHz and liver steatosis, indicating reasonable agreement (p<0.001)., Conclusion: BI analysis is a simple, non-invasive method that can be easily applied to evaluate liver steatosis., (Copyright © 2022, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Introduction: Fibroadenomas are common benign lesions of the breast that are usually found young patients. Giant fibroadenomas are uncommon benign lesions, defined as fibroadenomas of >5 cm in size, which are usually found in patients of less than 20 years of age., Presentation of Case: A 39-year-old premenopausal woman presented with a right breast tumor that had rapidly increased in size and which showed ulceration and bleeding. Needle biopsy showed mixed connective tissue and an epithelial tumor without a leaf-like pattern, but indeterminate. Total mastectomy and skin grafting were performed. Histopathology confirmed the diagnosis of giant fibroadenoma., Discussion: In comparison to all previous reports on patients with giant fibroadenoma, this patient was relatively old and the etiology was unknown. Although rare, an appropriate therapeutic strategy should be decided according to the results of a histopathological examination., Conclusion: Early treatment could allow breast preserving surgery and patients should be recommended to undergo reexamination with awareness of progression., (Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Lanabecestat (AZD3293; LY3314814) is an orally active potent inhibitor of human β-secretase 1 in clinical development for the treatment of Alzheimer disease. In this first Japanese clinical study for an Alzheimer disease intervention to include cerebrospinal fluid (CSF) sampling in Japanese elderly healthy subjects, we report the pharmacokinetics and effects on plasma and CSF amyloid-β (Aβ) peptides of lanabecestat in a phase 1 study involving 40 healthy Japanese subjects (NCT02005211). No safety and tolerability concerns were identified in healthy Japanese subjects exposed to lanabecestat up to the highest doses given, which is consistent with observations in a US phase 1 study of lanabecestat. Exposure to lanabecestat was similar for young and elderly subjects and increased in a dose-dependent manner. For elderly subjects, plasma lanabecestat half-life after multiple dosing was 12 to 17 hours (on days 10 and 14). Robust plasma and CSF Aβ peptide reductions were also seen at all doses, with CSF Aβ 42 concentrations reduced by 63% and 79% in the 15- and 50-mg lanabecestat groups, respectively. CSF soluble amyloid-β precursor protein β also decreased following lanabecestat treatment. Suppression of CSF Aβ peptides was similar in elderly healthy Japanese subjects and US patients with mild to moderate Alzheimer disease. Lanabecestat is a promising potentially disease-modifying treatment in phase 3 development for patients with early Alzheimer disease., (© 2017, The American College of Clinical Pharmacology.)

To predict drug-induced serious adverse events (SAE) in clinical trials, a model using a panel of cells derived from human induced pluripotent stem cells (hiPSCs) of individuals with different susceptibilities could facilitate major advancements in translational research in terms of safety and pharmaco-economics. However, it is unclear whether hiPSC-derived cells can recapitulate interindividual differences in drug-induced SAE susceptibility in populations not having genetic disorders such as healthy subjects. Here, we evaluated individual differences in SAE susceptibility based on an in vitro model using hiPSC-derived cardiomyocytes (hiPSC-CMs) as a pilot study. hiPSCs were generated from blood samples of ten healthy volunteers with different susceptibilities to moxifloxacin (Mox)-induced QT prolongation. Different Mox-induced field potential duration (FPD) prolongation values were observed in the hiPSC-CMs from each individual. Interestingly, the QT interval was significantly positively correlated with FPD at clinically relevant concentrations (r > 0.66) in multiple analyses including concentration-QT analysis. Genomic analysis showed no interindividual significant differences in known target-binding sites for Mox and other drugs such as the hERG channel subunit, and baseline QT ranges were normal. The results suggest that hiPSC-CMs from healthy subjects recapitulate susceptibility to Mox-induced QT prolongation and provide proof of concept for in vitro preclinical trials., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Introduction: Phosphodiesterase type 4 (PDE4) inhibition is a well-known anti-inflammatory mechanism. However, the clinical use of PDE4 inhibitors has been compromised by the occurrence of mechanism-associated adverse reactions, which often limit the maximum tolerated dose. To minimize systemic exposure, a topically active PDE4 inhibitor with low transdermal bioavailability could be clinically useful. The purpose of this study was to evaluate the efficacy of a novel topical PDE4 inhibitor, E6005, in patients with atopic dermatitis., Methods: This randomized, investigator-blinded, vehicle-controlled, multiple ascending dose study included 40 adult male patients with atopic dermatitis, who were randomly assigned to 10 days of treatment with either E6005 ointment (0.01, 0.03, 0.1 or 0.2%) or vehicle ointment., Results: Of 81 patients screened, 40 who had typical lesions on their posterior trunk were randomized into the study. One patient receiving 0.03% E6005 treatment discontinued because of acute gout and one receiving vehicle treatment discontinued because of progression of atopic dermatitis. The targeted lesion severity scores decreased in a concentration-dependent manner in patients treated with E6005. This drop was significant in the 0.2% E6005 ointment treatment group (mean percent change: -54.30%, p = 0.007)., Conclusion: E6005 ointment showed anti-inflammatory efficacy in adult patients with atopic dermatitis.

Background: DMB-3111 is a biosimilar trastuzumab drug being jointly developed by Meiji Seika Pharma (Japan) and Dong-A Socio Holdings (Korea). We investigated the bioequivalence of DMB-3111 relative to trastuzumab., Objectives: The aim of this study was to investigate the bioequivalence between DMB-3111 and trastuzumab and the pharmacokinetic, safety, and immunogenicity of both drugs in healthy Japanese adult males., Methods: Seventy healthy Japanese adult males were randomized 1:1 to receive either DMB-3111 or trastuzumab as a single intravenous infusion (6 mg/kg) over 90 min. Bioequivalence was assessed in terms of the pharmacokinetic parameters of both drugs. Adverse events (AEs) were graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. Immunogenicity was tested using anti-drug antibody (ADA) assays., Results: The 90% confidence intervals of the treatment differences (DMB-3111 versus trastuzumab) in the mean log-transformed maximum concentration, the area under the concentration-time curves (from 0 min to the last measured value or from 0 min to infinity), mean residence time, and the terminal half-life were within the accepted range for bioequivalence [log(0.80) to log(1.25)]. The frequencies of AEs and adverse drug reactions were similar with both drugs. No ADA reactivity to DMB-3111 or trastuzumab was observed in any subject., Conclusions: DMB-3111, a trastuzumab biosimilar, was bioequivalent to trastuzumab in terms of its pharmacokinetics and showed similar safety after a single intravenous infusion at 6 mg/kg over 90 min in healthy Japanese adult males. DMB-3111 is likely to show similar efficacy and safety profiles to trastuzumab in cancer patients (ClinicalTrials.gov #NCT02100917).

FSK0808 is a recombinant human granulocyte colony-stimulating factor developed by Fuji Pharma Co., Ltd and Mochida Pharmaceutical Co., Ltd. as a biosimilar product of Gran®. We verified the pharmacokinetic/pharmacodynamic equivalence of FSK0808 and commercially available Gran® by a randomized crossover study of single intravenous dose (200 µg/m(2)) and single subcutaneous dose (400 µg/m(2)) in healthy Japanese adult male subjects. According to the bioequivalence guidelines, the area under the blood concentration - time curve by 48 hours after administration (AUC0-48) in a single intravenous drip (IVD) study, and AUC0-48 and maximum blood concentration (Cmax) in a single subcutaneous (SC) dose study were used as primary endpoints, and the pharmacodynamic parameters including absolute neutrophil count (ANC) or number of CD34 positive cells (CD34(+) cells) as secondary endpoints. The safety was evaluated based on the characteristics and incidence of adverse reactions. As a result, the 90% confidence interval (CI) of the difference in mean value for AUC0-48 among drugs ranged from log(0.8) to log(1.25), in the IVD study, and those for Cmax and AUC0-48 were within the range of log(0.8)-log(1.25) in the SC study. Those for secondary endpoints were all within the range of log(0.8)-log(1.25). Thus, the pharmacokinetics/pharmacodynamics of both drugs were considered equivalent for all routes of administration, and the profiles of adverse reactions were also very similar.

FSK0808, a biosimilar of filgrastim, is a recombinant human granulocyte colony-stimulating factor developed by Fuji Pharmaceuticals and Mochida Pharmaceutical Co., Ltd. We conducted a double-blind, randomized, crossover study in healthy Japanese men, comparing the number of CD34-positive cells (CD34(+) cells) after repeated subcutaneous administration of either FSK0808 or the reference filgrastim (Gran(®) ). As primary endpoints, we compared the maximum number of CD34(+) cells (CD34(+)  Cmax ) and the time to reach CD34(+) Cmax (CD34(+) tmax ). As secondary endpoints, we compared the area under the curve for the number of CD34(+) cells over time at the 410 hours time point (CD34(+) AUC0-410 ), the parameters used to calculate the pharmacodynamic index of the absolute neutrophil count, and the pharmacokinetic parameters. Regarding the CD34(+) Cmax and the CD34(+) AUC0-410 values, the 95% confidence interval (CI) of the differences between the mean values for each drug was within the range of log(0.8)-log(1.25). With respect to the differences in the median values between drugs, the ratio against the reference filgrastim median value in the 95% CI was within the range of ± 0.2 for the CD34(+) tmax value. From these results, we considered that these drugs display equivalent pharmacodynamic and pharmacokinetic properties., (© 2015, The American College of Clinical Pharmacology.)

To investigate the potential for a QT/QTc study in Japan, a randomized, single-blind, crossover study was conducted using moxifloxacin in 64 healthy Japanese male volunteers. A 12-lead Holter electrocardiogram was used to test a relatively small population at each of 4 incorporated clinical research units to confirm the assay sensitivity and efficiency. Moxifloxacin (400 mg) significantly prolonged QT intervals, as previously reported, with small variations in this study. In addition, the placebo-adjusted mean QTcF changes from predose baseline showed that the lower bounds of the 1-sided 95% confidence interval exceeded 5 milliseconds at all of the clinical research units. The data also indicated statistically significant concentration-QT relationships in 3 of the 4 research units by separate analysis. These findings and the small amount of variability in this study suggest the feasibility of conducting a high-quality QT/QTc study in Japan.

Brivaracetam is a high-affinity synaptic vesicle protein 2A ligand, in phase 3 clinical development for epilepsy. A phase 1, single-center, randomized, double-blind, placebo-controlled, single (2.5-100 mg) and multiple (2.5-50 mg twice daily) rising oral dose study (N01209) was conducted to assess the adverse event profile and pharmacokinetics of brivaracetam in healthy Japanese men, and the influence of the cytochrome P450 (CYP) 2C19 genotype. Plasma and urine were collected serially for analysis of brivaracetam and its three main metabolites: acid, hydroxy and hydroxy acid. Overall, 79/80 randomized participants completed the study. Brivaracetam was generally well tolerated. After single- and multiple-dose administration, brivaracetam was rapidly absorbed, with dose-proportional pharmacokinetics over the dose ranges tested. Steady state was reached after 2 days of repeated dosing. Brivaracetam clearance (averaged across the five single dose levels) was reduced from 0.99 mL/min/kg in homozygous extensive metabolizers (EM; n = 10) to 0.81 mL/min/kg (-18%) in heterozygous EM (n = 17) and 0.70 mL/min/kg (-29%) in poor metabolizers (PM; n = 9). Exposure and urinary excretion of hydroxy metabolite were reduced 10-fold in PM participants, compared with EM participants. Results suggest that brivaracetam is hydroxylated by CYP2C19, but this pathway is minor compared with hydrolysis to the acid metabolite.

We investigated the mechanisms of ritonavir-mediated enhancement effect on the pharmacokinetics of saquinavir using in vivo probes for CYP3A4 (midazolam), p-glycoprotein (fexofenadine), and OATP1B1 (pravastatin) following oral micro/small dosing. A cocktail of the drugs (2 mg of saquinavir, 100 µg of each probe) was administered to eight healthy volunteers (phase 1), and then coadministered with 20 mg (phase 2) and 100 mg (phase 3) of ritonavir. Plasma concentrations of the drugs were measured by validated LC-MS/MS methods. The mean plasma AUC0-24 (pg hour/mL) of saquinavir at phases 1, 2, and 3 was 101, 2 540, and 23 900 (P < .01), respectively. The relative area under the plasma concentration-time curve (AUC)0-24 ratios of midazolam and fexofenadine at phases 1, 2, and 3 were 1:5.9:14.7 (P < .01), and 1:1.4:2.2 (P < .01-.05), respectively. In contrast, there was no difference in the pharmacokinetics of pravastatin. Inhibition of intestinal and hepatic CYP3A-mediated metabolism, and intestinal p-glycoprotein-mediated efflux of saquinavir, but not OATP1B1, is involved in the enhancement mechanism. Micro/small dosing is useful for examining the mechanism of drug interactions without safety concern., (© The Author(s) 2013.)

Objectives: To test whether the multiple phenotype and genotype relationships established using therapeutic dose, can be reproduced following oral microdosing using substrates of CYP2C9 (warfarin and glibenclamide), CYP2C19 (lansoprazole), CYP2D6 (dextromethorphan), and OATPs (glibenclamide)., Methods: A cocktail of test drugs was administered orally under the microdose in liquid or capsule form, and then a therapeutic dose of dextromethorphan was administered to 17 healthy subjects whose genotypes for CYPs and OATPs had been prescreened. Concentrations of the drugs and their metabolites were measured by LC-MS/MS., Results: The AUC and t1/2 of glibenclamide following the microdosing tended to be higher and longer, respectively, in CYP2C9*1/*3 than CYP2C9*1/*1 subjects. In contrast, there were no significant differences in any of the pharmacokinetic parameters for warfarin between the two genotypes. For CYP2D6 following the therapeutic dose, there was good concordance between genotype and phenotype; however, such relationships disappeared after microdosing. For CYP2C19 following the microdosing, there were significant differences between EMs and PMs in the pharmacokinetic parameters of lansoprazole. The relative AUC0-12 ratio of lansoprazole in EMs and PMs was 1:3.3 - 4.3. Among test drugs, phenotypic measurements of lansoprazole accorded well with the CYP2C19 genotype at the microdose as well as therapeutic dose., Conclusions: The present study suggests that 1) the sampling strategy should be optimized according to pharmacokinetic profiles of the test drugs following oral microdosing, and 2) microdosing can be applied to the pharmacogenomic study of CYP-specific drugs.

Asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, is mainly degraded by dimethylarginine dimethylaminohydrolase (DDAH). It was recently reported that reduced DDAH expression could contribute to ADMA accumulation and subsequent elevation of BP in an experimental model of chronic kidney disease (CKD). ADMA is a strong predictor of the progression of CKD as well. However, a role for the ADMA-DDAH in the pathogenesis of CKD remains to be elucidated. This study investigated the effects of DDAH-elicited ADMA lowering on renal function and pathology in a rat remnant kidney model. Four weeks after five-sixths subtotal nephrectomy (Nx), the rats were given tail-vein injections of recombinant adenovirus vector encoding DDAH-I (Adv-DDAH) or control vector expressing bacterial beta-galactosidase (Adv-LZ) or orally administered 20 mg/kg per d hydralazine (Hyz), which served as a BP control model. In comparison with Adv-LZ or Hyz administration, Adv-DDAH decreased plasma levels of ADMA and inhibited the deterioration of renal dysfunction. Plasma levels of ADMA were associated with decreased number of peritubular capillaries, increased tubulointerstitial fibrosis, and proteinuria levels in Nx rats. These changes were progressed in Adv-LZ-or Hyz-treated Nx rats, which were ameliorated by DDAH overexpression. In addition, semiquantitative reverse transcriptase-PCR and immunohistochemistry for TGF-beta revealed that Adv-DDAH inhibited upregulation of TGF-beta expression in Nx rats. These data suggest that ADMA may be involved in peritubular capillary loss and tubulointerstitial fibrosis, thereby contributing to the progression of CKD. Substitution of DDAH protein or enhancement of its activity may become a novel therapeutic strategy for the treatment of CKD.

Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide synthase. ADMA is generated by protein methyltransferase (PRMT) and is metabolized mainly by dimethylarginine dimethylaminohydrolase (DDAH). ADMA levels are reported to increase in patients with chronic kidney disease (CKD), thereby playing a role in the pathogenesis of accelerated atherosclerosis in this population. However, the precise mechanism underlying ADMA accumulation in these patients is not fully understood. This study investigated the molecular mechanism for the elevation of ADMA levels in CKD, using a rat remnant kidney model that represents progressive CKD. After male Sprague-Dawley rats underwent baseline measurement of BP and renal function, 5/6 subtotal nephrectomy (5/6Nx) and 4/6 nephrectomy were performed. Plasma and urinary levels of ADMA and symmetric dimethylarginine, an inert isomer of ADMA, were measured by HPLC. Expression levels of PRMT genes and DDAH proteins were analyzed by semiquantitative reverse transcription-PCR and Western blotting, respectively. Plasma ADMA levels were elevated in the Nx groups in proportion to the degree of nephrectomy despite marked increases in renal clearance of ADMA. In contrast, renal clearance of symmetric dimethylarginine was decreased and its plasma levels were increased in the Nx groups. Furthermore, both liver and kidney gene expression of PRMT was increased, whereas DDAH protein expression was decreased in the 5/6Nx group. Plasma ADMA levels were correlated with systolic BP levels. Moreover, adenovirus-mediated DDAH gene transfer into the 5/6Nx rats prevented the elevation of BP levels, which was associated with the reduction of plasma and urinary ADMA levels. The results presented here suggest that decreased DDAH levels as well as increased PRMT gene expression could cause the elevation of plasma ADMA levels, thereby eliciting hypertension in CKD. Substitution of DDAH protein or enhancement of its activity may become a novel therapeutic strategy for the treatment of hypertension-related vascular injury in CKD.

Objectives: We conducted a randomized, double-blind, placebo-controlled study to evaluate the pharmacokinetics and pharmacodynamics of landiolol hydrochloride in a dose escalation regimen in healthy male volunteers., Methods: We set two-dose escalation regimen (LM and MH groups) using three different doses [L (low): 0.03 mg/kg/min (1 min) loading-->0.01 mg/kg/min (10 min) continuous, M (medium): 0.06 mg/kg/min (1 min) loading-->0.02 mg/kg/min (10 min) continuous, H (high): 0.125 mg/kg/min (1 min) loading-->0.04 mg/kg/min (10 min) continuous]. Sixteen subjects were allocated randomly to the LM, MH, and placebo groups (n=6, 6, and 4, respectively)., Results: In both the LM and MH groups, the blood concentration of landiolol hydrochloride changed within a constant range from 2 minutes after initiation of administration to just before the higher dose escalation. By 2 minutes following the higher dose escalation, the concentration of landiolol hydrochloride reached C(max), and reached almost steady state levels until 6 minutes following administration of the higher dose. The t(1/2) of landiolol hydrochloride was 3.5 minutes. The heart rates and blood pressures of subjects administered landiolol hydrochloride decreased, but there were no adverse events in any subject., Conclusions: The concentration of landiolol hydrochloride rapidly reached steady state levels, and rapidly dissipated after completion of administration.