Search

Introduction The hematology analyzer, Celltac G (Nihon Kohden), designed to improve platelet count (Plt) accuracy, is equipped with new sheath flow control technology. Clinical evaluation of the Celltac G was assessed by comparability with XN-9000 (Sysmex Corporation) and CELL-DYN Sapphire (Abbott Diagnostics). The accuracy of all three analyzers, which use different measuring principles, was compared with the immunoplatelet reference method (FCM-Ref). Methods Repeatability and within-laboratory imprecision were assessed using 10 clinical fresh whole blood samples and three control materials with differing levels. Carryover was evaluated using 6 clinical fresh whole blood samples. For method comparison between the three analyzers, 388 samples were used. Plt accuracy among the three analyzers was evaluated using 54 blood samples, including 42 samples with a platelet count less than 50x109 /L. The International Council for Standardization in Haematology method for Plt was used as the FCM-Ref. Results The Celltac G showed sufficient performance with regard to imprecision, carryover, and comparability. The Analytical Measurement Interval (AMI) and linearity for all parameters of Plt were validated within 4.6 to 809.1 (×109 /L). All hematology analyzers showed some disagreement in Plt when compared with the immunoplatelet reference method. Conclusion The Celltac G hematology analyzer is suitable for clinical use. Platelet count evaluation of the three analyzers suggests the need to determine a reportable measurement interval (RMI) in the clinical laboratory for adequate reporting of a Plt from multiple different values.

6-Methylsulfinylhexyl isothiocyanate (6-MSITC) is a bioactive ingredient present in Japanese horseradish (wasabi) and has been shown to be an Nrf2 activator. To determine whether 6-MSITC ameliorates hepatic steatosis and iron accumulation, wild-type and Nrf2-null mice were fed the following diets for 12 weeks: 1) control diet, 2) high-fat diet (HFD), 3) HFD plus 6-MSITC (10mg/Kg/day ip), 4) HFD for 6 weeks followed by an iron-supplemented HFD for 6 weeks (HFD/Iron), 5) HFD/Iron plus 6-MSITC. The HFD increased hepatic triglycerides in both genotypes and 6-MSITC suppressed increased hepatic triglycerides in wild-type mice but did not reduce these triglycerides in Nrf2-null mice. Compared to the HFD and HFD/Iron groups, respectively, 6-MSITC did not block hepatic iron accumulation in either genotype. This article is protected by copyright. All rights reserved.

Background and Aim: Hepatic excessive iron may play a role in the pathogenesis of non-alcoholic steatohepatitis (NASH). Nrf2 is a master regulator of antioxidative responses. However, the role of Nrf2 in lipid and iron homeostasis remains unclear. Accordingly, it was examined how Nrf2 regulates lipid-related and iron-regulatory genes after feeding a high-fat diet (HFD) with iron. Methods: Wild-type and Nrf2-null mice were fed the following diets: (i) control diet (4% soybean oil) for 12 weeks, (ii) control diet for 8 weeks followed by control diet containing 0.5% carbonyl iron for 4 weeks, (iii) HFD (4% soybean oil and 16% lard) for 12 weeks, (iv) HFD for 8 weeks followed by HFD containing 0.5% carbonyl iron for 4 weeks. Blood and livers were removed after 12 weeks. Results: Nrf2-null control mice exhibited a tendency towards higher hepatic triglycerides compared to wild-type control mice. Hepatic malondialdehyde was higher and hepatic iron levels tended to be higher in Nrf2-null mice than wild-type counterparts while on a HFD. The HFD with iron synergistically induced mRNA expression of Pparα targets, including Acox and Cpt1 in wild-type mice, yet the induction was diminished in Nrf2-null mice. Hepatic hepcidin and ferroportin 1 mRNA expression were increased in wild-type mice after feeding a HFD with iron, but were unchanged in any group of Nrf2-null mice. Conclusions: Nrf2 deletion dysregulates hepatic mRNA expression of β-oxidation enzymes and iron-related genes, possibly causing a trend for increased hepatic triglyceride and iron concentrations. Nrf2 may have roles in the progression of NASH.

Aim: Fish oil rich in n-3 polyunsaturated fatty acids is known to affect hepatic lipid metabolism. Several studies have demonstrated that fish oil may affect the bile acid metabolism as well as lipid metabolism, whereas only scarce data are available. The aim of this study was to investigate the effect of fish oil on the gene expression of the transporters and enzymes related to bile acid as well as lipid metabolism in the liver and small intestine. Methods: Seven-week old male C57BL/6 mice were fed diets enriched in 10% soybean oil or 10% fish oil for 4 weeks. After 4 weeks, blood, liver and small intestine were obtained. Results: Hepatic mRNA expression of lipids (Abcg5/8, multidrug resistance gene product 2) and bile acids transporters (bile salt export pump, multidrug resistance associated protein 2 and 3, organic solute transporter α) was induced in fish oil-fed mice. Hepatic Cyp8b1, Cyp27a1 and bile acid CoA : amino acid N-acyltransferase were increased in fish oil-fed mice compared with soybean-oil fed mice. Besides, intestinal cholesterol (Abcg5/8) and bile acid transporters (multidrug resistance associated protein 2 and organic solute transporter α) were induced in fish oil-fed mice. Conclusion: Fish oil induced the expression of cholesterol and bile acid transporters not only in liver but in intestine. The upregulation of Abcg5/g8 by fish oil is caused by an increase in cellular 27-HOC through Cyp27a1 induction. The hepatic induction of bile acid synthesis through Cyp27a1 may upregulate expression of bile acid transporters in both organs.

Background and Aim: To evaluate the importance of cholesterol and bile acid concentrations in the intestinal lumen to cholesterol homeostasis, we investigated the effect of cholesterol-, bile salt- or cholestyramine-administration on the regulation of intestinal mRNA related to cholesterol and bile acid metabolism. Methods: Male Wistar rats fed on standard laboratory chow (AIN-93) were allocated into four experimental groups: (i) control group; (ii) cholesterol group (CH), which was fed cholesterol in diet (2% [w/w]) for 14 days; (iii) cholic acid (CA) group, which was fed CA in diet (1% [w/w]) for 14 days; (iv) cholestyramine (CT) group, which was fed CT in diet (5% [w/w]) for 14 days. Blood, liver and small intestine were obtained after 14 days. Serum lipids and bile acids were measured by colorimetric assays, and hepatic and intestinal mRNA relating to lipid and bile acid metabolism was studied by reverse transcription–polymerase chain reaction. Results: Intestinal ABCG8, liver X receptor α, small heterodimer partner (SHP) and sterol regulatory element binding protein 1c (SREBP-1c) mRNA expressions were markedly increased in the CH group. Intestinal multidrug resistance associated protein (MRP) 2 and MRP3 mRNA expressions were markedly increased in the CA group. In the CT group intestinal MRP2, ABCG5, ABCG8, SHP and SREBP-1c mRNA expressions were markedly decreased. Conclusion: The bile acid availability in the intestinal lumen alters the expression of various intestinal mRNA relating to not only bile acid metabolism, but also lipid metabolism. Though the mechanism of the intestinal SHP elevation is unclear, cholesterol feeding may affect the intestinal bile acid metabolism via intestinal SHP expression.

Background and Aim: Multidrug resistance associated gene product 2 (Mdr2) is believed to have a significant role in biliary cholesterol and phospholipid secretions. Both pravastatin and bezafibrate resulted in Mdr2 induction, but increased cholesterol secretion was observed only in pravastatin treatment. To explore the mechanism, the hepatic expression of genes that are responsible for the metabolism of the lipids was studied. Methods: Rats were divided into three experimental groups: (i) the control group; (ii) the bezafibrate group, which was fed a diet containing 0.45% bezafibrate for 5 days; and (iii) the pravastatin group, which was fed a diet containing 0.1% pravastatin for 5 days. Serum, hepatic and biliary lipids were measured by colorimetric assays and hepatic mRNA related to lipid metabolism was studied by reverse transcription–polymerase chain reaction (RT-PCR). Results: In the bezafibrate group biliary phospholipid secretion was increased although cholesterol secretion was not increased. In the pravastatin group, biliary cholesterol and phospholipid secretions were significantly increased. The biliary cholesterol/phospholipid ratio was decreased in the bezafibrate group, but the ratio did not change in the pravastatin group. Hepatic Mdr2, Abcg5 and Abcg8 mRNA expression was remarkably increased in the pravastatin group in comparison with the control group (184%, 264% and 247% of control value, respectively). In the bezafibrate group the hepatic gene expression of Mdr2 was increased (157% of control value), but there were no significant changes in hepatic Abcg5 and Abcg8 mRNA expression compared with the control group. Conclusions: Compared with Mdr2, Abcg5 and Abcg8 seem to be more essential transporters for biliary secretion of cholesterol. Pravastatin upregulated Abcg5/Abcg8 while bezafibrate did not, which appears to explain the different effects of these compounds on biliary lipid secretion. © 2004 Blackwell Publishing Asia Pty Ltd

Hepatic excretion of non-bile acid organic anions is reported to be ATP-dependent and a defect of this transport has been reported in congenitally jaundiced rats, animal models of human Dubin-Johnson syndrome. To investigate the effect of the transmembrane pH gradient on hepatocyte canalicular membrane transport of ATP-dependent organic anions, uptake of pravastatin, a 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase-inhibiting organic anion, by hepatocyte canalicular membrane vesicles was observed in the presence or absence of transmembrane pH gradients. Uptake was assessed by a rapid filtration technique. ATP-dependent pravastatin uptake was stimulated in the presence of a transmembrane pH gradient (in > out) in Sprague-Dawley (SD) rats. Uptake was dependent on both pravastatin and ATP concentrations and showed saturation kinetics. After intravenous injection of [ 14 C]-pravastatin (0.3 μmol), 81% of the dose was excreted in the bile within 35 min in SD rats, whereas only 20% was excreted in the bile in Eisai hyperbilirubinuria rats. ATP and the pH gradient also co-stimulated the uptake of pravastatin in Eisai hyperbilirubinuria rats, although the K m was much higher and V max was much lower than corresponding values in SD rats. This coincided well with the marked reduction in in vivo biliary excretion of pravastatin in jaundiced rats.