Evaluation of Parent- and Metabolite-Induced Mitochondrial Toxicities Using CYP-Introduced HepG2 cells.

Mitochondrial toxicity is an important factor to predict drug-induced liver injury (DILI). Previous studies have focused predominantly on mitochondrial toxicities due to parent forms, and no study has adequately evaluated metabolite-induced mitochondrial toxicity. Moreover, previous studies have used HepG2 cells, which lack many cytochrome P450 (CYP) genes.

Assessment of Protein Binding of 5-Hydroxythalidomide Bioactivated in Humanized Mice with Human P450 3A-Chromosome or Hepatocytes by Two-Dimensional Electrophoresis/Accelerator Mass Spectrometry.

Bioactivation of 5-hydroxy-[carbonyl-(14)C]thalidomide, a known metabolite of thalidomide, by human artificial or native cytochrome P450 3A enzymes, and nonspecific binding in livers of mice was assessed using two-dimensional electrophoresis combined with accelerator mass spectrometry. The apparent major target proteins were liver microsomal cytochrome c oxidase subunit 6B1 and ATP synthase subunit α in mice containing humanized P450 3A genes or transplanted humanized liver. Liver cytosolic retinal dehydrogenase 1 and glutathione transferase A1 were targets in humanized mice with P450 3A and hepatocytes, respectively.

Non-invasive Measurement of Skin Autofluorescence as a Beneficial Surrogate Marker for Atherosclerosis in Patients with Type 2 Diabetes.

Advanced glycation end-products (AGEs) are thought to play a major role in the pathogenesis of diabetic vascular complications. Skin autofluorescence (AF) was recently reported to represent tissue AGEs accumulation with a non-invasive method. The aim of the present study was to evaluate association between AF value and diabetic vascular complications, such as retinopathy, nephropathy and cervical atherosclerosis using the carotid intima-media thickness (IMT), an established marker of cardiovascular disease in patients with type 2 diabetes.

Predictability of plasma concentration-time curves in humans using single-species allometric scaling of chimeric mice with humanized liver.

1. We used chimeric mice (PXB mice®), which were repopulated with human hepatocytes, to evaluate their predictabilities of human pharmacokinetics. 2.

Fluorometric assessment of acetaminophen-induced toxicity in rat hepatocyte spheroids seeded on micro-space cell culture plates.

Hepatotoxicity induced by the metabolic activation of drugs is a major concern in drug discovery and development. Three-dimensional (3-D) cultures of hepatocyte spheroids may be superior to monolayer cultures for evaluating drug metabolism and toxicity because hepatocytes in spheroids maintain the expression of various metabolizing enzymes and transporters, such as cytochrome P450 (CYP). In this study, we examined the hepatotoxicity due to metabolic activation of acetaminophen (APAP) using fluorescent indicators of cell viability and intracellular levels of glutathione (GSH) in rat hepatocyte spheroids grown on micro-space cell culture plates.

Validation of uPA/SCID mouse with humanized liver as a human liver model: protein quantification of transporters, cytochromes P450, and UDP-glucuronosyltransferases by LC-MS/MS.

Chimeric mice with humanized liver (PXB mice) have been generated by transplantation of urokinase-type plasminogen activator/severe combined immunodeficiency mice with human hepatocytes. The purpose of the present study was to clarify the protein expression levels of metabolizing enzymes and transporters in humanized liver of PXB mice transplanted with hepatocytes from three different donors, and to compare their protein expressions with those of human livers to validate this human liver model. The protein expression levels of metabolizing enzymes and transporters were quantified in microsomal fraction and plasma membrane fraction, respectively, by means of liquid chromatography-tandem mass spectrometry.

Prediction of human metabolism of the sedative-hypnotic zaleplon using chimeric mice transplanted with human hepatocytes.

1. Human chimeric mice (h-PXB mice) having humanized liver, constructed by transplantation of human hepatocytes, were evaluated as an experimental model for predicting human drug metabolism. Metabolism of zaleplon in h-PXB mice was compared with that in rat chimeric mice (r-PXB mice) constructed by transplantation of rat hepatocytes.

Predictability of metabolism of ibuprofen and naproxen using chimeric mice with human hepatocytes.

Prediction of human drug metabolism is important for drug development. Recently, the number of new drug candidates metabolized by not only cytochrome P450 (P450) but also non-P450 has been increasing. It is necessary to consider species differences in drug metabolism between humans and experimental animals.

Association of IFNGR2 gene polymorphisms with pulmonary tuberculosis among the Vietnamese.

Interferon-γ (IFN-γ) is a key molecule of T helper 1 (Th1)-immune response against tuberculosis (TB), and rare genetic defects of IFN-γ receptors cause disseminated mycobacterial infection. The aim of the present study was to investigate whether genetic polymorphisms found in the Th1-immune response genes play a role in TB. In our study, DNA samples were collected from two series of cases including 832 patients with new smear-positive TB and 506 unrelated individuals with no history of TB in the general population of Hanoi, Vietnam.

Prediction of in vivo hepatic clearance and half-life of drug candidates in human using chimeric mice with humanized liver.

Accurate prediction of pharmacokinetics (PK) parameters in humans from animal data is difficult for various reasons, including species differences. However, chimeric mice with humanized liver (PXB mice; urokinase-type plasminogen activator/severe combined immunodeficiency mice repopulated with approximately 80% human hepatocytes) have been developed. The expression levels and metabolic activities of cytochrome P450 (P450) and non-P450 enzymes in the livers of PXB mice are similar to those in humans.

Expression levels of drug-metabolizing enzyme, transporter, and nuclear receptor mRNAs in a novel three-dimensional culture system for human hepatocytes using micro-space plates.

We evaluated a novel three-dimensional primary culture system using micro-space plates to determine the expression levels of 61 target (drug-metabolizing enzymes, transporters, and nuclear receptors) mRNAs in human hepatocytes. We measured mRNA expression levels of many target genes in four lots of cryopreserved human hepatocyte primary cells after 120 h of culture and compared differences in mRNA expression levels between cultures using traditional plates and those using micro-space plates. In this study, we show that the mRNA levels of many experimental targets in human hepatocytes before inoculation resemble the levels inside the human liver.

Activation of morphine glucuronidation by fatty acyl-CoAs and its plasticity: a comparative study in humans and rodents including chimeric mice carrying human liver.

The formation of morphine-3-glucuronide (M-3-G, pharmacologically inactive) and morphine-6-glucuronide (M-6-G, active metabolite) by liver microsomes from humans and rodents, including chimeric mice carrying human liver, was evaluated in the presence of fatty acyl-CoAs. Medium- to long-chain fatty acyl-CoAs, including oleoyl-CoAs, at a physiologic level (around 15 microM) markedly enhanced M-3-G formation catalyzed by rat liver microsomes. A separate experiment indicated that 15 microM oleoyl-CoA enhanced (14)C-UDP-glucuronic acid (UDPGA) uptake by microsomes.

Secretion of albumin and induction of CYP1A2 and CYP3A4 in novel three-dimensional culture system for human hepatocytes using micro-space plate.

We evaluated a novel primary three-dimensional culture system for human hepatocytes using micro-space plates. The functional activity of human hepatocytes in primary culture was determined by measuring albumin secretion from hepatocytes to medium and measuring expression levels of albumin, CYP1A2 and CYP3A4 mRNA. Albumin secretion was higher in micro-space plates compared with traditional plates after 72 h of culture; the levels of albumin secretion from hepatocytes to medium in culture using micro-space plates after 96 h of culture were 2.

A study of the effect of the femoral head diameter on prosthetic hip joint dislocation using a hip-joint motion simulator.

Prosthetic hip joint dislocation phenomenon is generated by the hip joint simulator and the effect of the femoral head diameter is studied under the same condition which is similar to the condition in daily activities. Impedance control is applied to control the hip joint motion and the joint contact force simultaneously in order to take into account the constraint caused by surrounding tendons, muscles, and a joint capsule of the hip joint. The experimental results show that the hip joint dislocation phenomenon is generated by the simulator and the obtained results about the effect of the femoral head size agree with those of the other research.

Approach for in vivo protein binding of 5-n-butyl-pyrazolo[1,5-a]pyrimidine bioactivated in chimeric mice with humanized liver by two-dimensional electrophoresis with accelerator mass spectrometry.

Drug development of a potential analgesic agent 5-n-butyl-7-(3,4,5-trimethoxybenzoylamino)pyrazolo[1,5-a]pyrimidine was withdrawn because of its limited hepatotoxic effects in humans that could not be predicted from regulatory animal or in vitro studies. In vivo formation of glutathione conjugates and covalent binding of a model compound 5-n-butyl-pyrazolo[1,5-a]pyrimidine were investigated in the present study after intravenous administration to chimeric mice with a human or rat liver because of an interesting capability of human cytochrome P450 1A2 in forming a covalently bound metabolite in vitro. Rapid distribution and elimination of radiolabeled 5-n-butyl-pyrazolo[1,5-a]pyrimidine in plasma or liver fractions were seen in chimeric mice after intravenous administration.

Prediction of human disposition toward S-3H-warfarin using chimeric mice with humanized liver.

Chimeric mice, constructed by transplanting human hepatocytes, are useful for predicting the human metabolism of drug candidates. In this study, we investigated whether these mice show similar metabolic profile to humans by examining the hydroxylation of S-warfarin reported to be mainly metabolized to S-7-hydroxywarfarin (7-OH-warfarin), catalyzed by CYP2C9, in humans. When S-(3)H-warfarin was administered to chimeric mice and control (uPA(+/+)/SCID(wt/wt)) mice, the blood concentration-time curve was higher in chimeric than control mice.

Influence of tumor peroxisome proliferator-activated receptor gamma and delta expression on postoperative mortality of patients undergoing colorectal cancer surgery.

Purpose: To evaluate the influence of peroxisome proliferator-activated receptor gamma (PPAR gamma) and delta (PPAR delta) expression on postoperative mortality of patients with colorectal cancer (CRC).

Methods: Optimal cutoff values were determined for each relative expression ratio (RER) (RER = PPAR expression of tumor/PPAR expression of normal mucosa) of PPAR, and patients were divided into two groups as follows (PPAR staging): patients with elevated RERs of PPAR gamma (> 2.0) or PPAR delta (> 1.

CYP2C9-catalyzed metabolism of S-warfarin to 7-hydroxywarfarin in vivo and in vitro in chimeric mice with humanized liver.

Chimeric mice having humanized livers were constructed by transplantation of human hepatocytes. In this study, we investigated whether these mice have a capacity for drug metabolism similar to that of humans by examining hydroxylation of S-warfarin, which is predominantly metabolized to S-7-hydroxywarfarin, catalyzed by CYP2C9, in humans but not mice. The 7-hydroxylating activity of chimeric mouse liver microsomes toward S-warfarin was approximately 10-fold higher than that of control (urokinase-type plasminogen activator-transgenic severe combined immunodeficient) mice.

POSSUM is an optimal system for predicting mortality due to colorectal perforation.

Background/aims: The purpose of this study was to determine the most useful predictive scoring system for the postoperative mortality of patients with colorectal perforation using the Acute Physiological and Chronic Health Evaluation II (APACHE II), Sequential Organ Failure Assessment (SOFA) and Physiological and Operative Severity Score for the enUmeration of Mortality (POSSUM).

Methodology: First, the 3 scoring systems were applied to all patients, and the efficacy of these systems was compared between survivors and non-survivors. Second, using receiver operating characteristic (ROC) curve analysis, optimal cut-off values were determined for each system and patients were divided into another two groups (high score group and low score group).

Aldehyde oxidase-catalyzed metabolism of N1-methylnicotinamide in vivo and in vitro in chimeric mice with humanized liver.

Aldehyde oxidase-mediated oxidation of N(1)-methylnicotinamide to N(1)-methyl-2-pyridine-5-carboxamide (2-PY) and N(1)-methyl-4-pyridone-5-carboxamide (4-PY) in chimeric mice constructed by transplanting human hepatocytes into urokinase-type plasminogen activator-transgenic severe combined immunodeficient mice was examined in vivo and in vitro. The activity in liver cytosol of chimeric mice with a high replacement index was approximately 4-fold higher than that in control mice. Furthermore, the oxidation products in control mice were 2-PY and 4-PY, whereas, in chimeric mice, the major product was 2-PY, as in humans.

Usefulness of Groshong catheters for central venous access via the external jugular vein.

This study was designed to evaluate the usefulness of central venous access via the external jugular vein (EJV) employing Groshong catheters, and to compare the complications with those of conventional internal jugular venous catheterization. Central venous access was achieved by insertion of a single-lumen 4.0 Fr Groshong catheter via the EJV or internal jugular vein (IJV) with a single puncture.

Inflammation-based prognostic score is a novel predictor of postoperative outcome in patients with colorectal cancer.

Objective: To investigate the significance of preoperative Glasgow prognostic score (GPS) for postoperative prognostication of patients with colorectal cancer.

Background: Recent studies have revealed that the GPS, an inflammation-based prognostic score that includes only C-reactive protein (CRP) and albumin, is a useful tool for predicting postoperative outcome in cancer patients. However, few studies have investigated the GPS in the field of colorectal surgery.

External jugular Groshong catheter is associated with fewer complications than a subclavian Argyle catheter.

Background: To demonstrate the efficacy and safety of insertion of a Groshong catheter via the external jugular vein (EJV) for central vein access.

Methods: Central venous access was done by either insertion of a Groshong catheter via the EJV or an Argyle catheter via the subclavian vein with single puncture.

Results: Eighty patients (group 1) were treated with 146 subclavian venous catheters for 2,770 catheter-days, and 98 patients (group 2) were treated with 147 external jugular venous catheters for 2,381 catheter-days.

Rectal angiolipoma diagnosed after surgical resection: a case report.

Angiolipoma is a common benign tumor with a characteristic vascular component that usually occurs in subcutaneous tissue. Although lipomas are frequently encountered at colonoscopy as submucosal tumors, angiolipomas are rarely found in the gastrointestinal tract including the large intestine. Here we report a 77-year old Japanese man who underwent transanal resection of a tumor that was diagnosed tentatively as a leiomyoma.

Characterization of humanized liver from chimeric mice using coumarin as a human CYP2A6 and mouse CYP2A5 probe.

Coumarin 7-hydroxylation (COH), which is catalyzed almost solely by human CYP2A6 and mouse CYP2A5, shows large differences in activity (humans>>mice) and inhibitor specificity between mice and humans. To differentiate human and mouse liver functions of chimeric mice (CM1, CM2 and CM3) prepared with hepatocytes from 3 donors, the microsomal COH activities were measured with and without benzaldehyde and undecanoic gamma-lactone as a specific inhibitor of human CYP2A6 and mice CYP2A5, respectively. The replacement % to human hepatocytes designated as replacement index (RI) was calculated from human specific cytokeratin 8/18 expression in the liver section.