178 resultados para HEPATIC BIOTRANSFORMATION


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The purpose of the present article was to present the series operated by a Liver Transplant Group of the interior of the State of Sao Paulo, Brazil. Sixty patients were transplanted from May 2001 to May 2007. Thirty percent of the patients had alcoholic cirrhosis. 18.3% had C virus-induced cirrhosis, 10% had C virus- and alcohol-induced cirrhosis, 6% had B virus-induced cirrhosis, 13.3% had cryptogenic cirrhosis, 8.3% autoimmune cirrhosis, 13.3% had familial amyloidotic polyneuropathy (FAP), and 13.3% had hepatocellular carcinomas. The series was divided by a chronological criterion into two periods: A (n = 42) and B (n = 18) with the latter group operated based upon the Model for End-stage Liver Disease (MELD) criterion. Sixty-nine percent were men. Age ranged from 14 to 66 years. Period A included 12% Child A: 59.2%, Child B; 24%, Child C; and 4.8%, FAR Period B comprises 22.2% Child A: 11.1%, Child B: 33.3%, Child C: and 33.3%, FAP. MELD scores ranged from 8 to 35 for period A and from 14 to 31 for period B. Intraoperative mortality was 2/42 patients for period A and 0/18 for period B, overall postoperative mortality was 40% including for period A, 35% among Child B and C patients, and 5 % among FAP and Child A patients (P <.05) and 16.6% for period B among 11. 1 % Child B patients and 5.5 % FAP patients; 3.3 % of patients required retransplantation due to hepatic artery thrombosis. Real postoperative survival was 60% during period A and 83.3% during period B, with an overall survival rate of 67% for the two periods. The present results show levels of postoperative mortality, (especially during period B), and survival rates similar to those reported by several other centers in Brazil.

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The study analyzed the effects of chronic alcohol ingestion on the ultrastructure of the lining epithelium of the hard palatine mucosa of rats UChA and UChB (lines with voluntary alcohol consumption) in order to contribute to the understanding of the consequences of alcohol abuse for the morphology of the digestive system. Thirty female adult animals aged 120 days were divided into three experimental groups. (1) Ten UChA rats (genetically low ethanol consumer) with voluntary intake of 10% v/v (5.45 g/kg/day) ethanol solution and water. (2) Ten UChB (genetically high ethanol consumer) rats with voluntary intake of 10% v/v (7.16 g/kg/day) ethanol solution and water. (3) Ten Wistar rats with voluntary ad libitum water intake (control group). Both groups received Nuvital pellets ad libitum. The IGFR-I expression was intense in both experimental groups. The epithelial cells of the alcoholic rats UChA and UChB showed many alterations such as the presence of lipid droplets, altered nuclei, nuclei in corneum layer and disrupted mitochondria. It was concluded that ethanol intake induces ultrastructural lesions in the hard palatine mucosa. (C) 2011 Elsevier Ltd. All rights reserved.

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Folic acid (FA) supplementation during carcinogenesis is controversial. Considering the impact of liver cancer as a public health problem and mandatory FA fortification in several countries, the role of FA supplementation in hepatocarcinogenesis should be elucidated. We evaluated FA supplementation during early hepatocarcinogenesis. Rats received daily 0.08 mg (FA8 group) or 0.16 mg (FA16 group) of FA/100 g body weight or water (CO group, controls). After a 2-week treatment, animals were subjected to the ""resistant hepatocyte"" model of hepatocarcinogenesis (initiation with diethylnitrosamine, selection/promotion with 2-acetylaminofluorene and partial hepatectomy) and euthanized after 8 weeks of treatment. Compared to the CO group, the FA16 group presented: reduced (p < 0.05) number of persistent and increased (p < 0.05) number of remodeling glutathione S-transferase (GST-P) positive preneoplastic lesions (PNL); reduced (p < 0.05) cell proliferation in persistent GST-P positive PNL; decreased (p < 0.05) hepatic DNA damage; and a tendency (p < 0.10) for decreased c-myc expression in microdissected PNL. Regarding all these parameters, no differences (p > 0.05) were observed between CO and FA8 groups. FA-treated groups presented increased hepatic levels of S-adenosylmethionine but only FA16 group presented increased S-adenosylmethionine/S-adenosylhomocysteine ratio. No differences (p > 0.05) were observed between experimental groups regarding apoptosis in persistent and remodeling GST-P positive PNL, and global DNA methylation pattern in microdissected PNL. Altogether, the FA16 group, but not the FA8 group, presented chemopreventive activity. Reversion of PNL phenotype and inhibition of DNA damage and of c-myc expression represent relevant FA cellular and molecular effects.

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Acetone is considered to be a substance that can disturb cellular oxidative status, being also associated with the production of glucose during its metabolization. The objective of the present study was to determine the effects of chronic treatment with acetone in oxidative stress and metabolic parameters in rats. Twenty male Wistar rats were divided into two groups: control (CG) and chronic acetone group (CAG). After 28 days of acetone ingestion in a 5% aqueous solution (CAG) or water (CG) the animals were euthanized and urine, plasma and liver were collected for the determination of acetone, glucose, lipemia, hepatic fat, malondialdehyde (MDA), reduced glutathione (GSH), and vitamin E. As expected, urinary and plasma acetone levels were higher in CAG. There was no difference in hepatic MDA values between groups, whereas hepatic GSH was lower in CAG than in CG and hepatic vitamin E was higher in CAG than in CG. There was also an increase in glycemia, cholesterolemia and hepatic fat in CAG compared to CG. Chronic treatment with a 5% acetone solution produced an increase in acetonemia that was able to promote changes in hepatic oxidative metabolism and in lipid content in rats similar to those observed in nonalcoholic steatohepatitis.

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The pharmacokinetics of cyclophosphamide (CYC) enantiomers were evaluated in patients with lupus nephritis distributed in 2 groups according to creatinine clearance: group 1 (90.6-144.6 mL/min/1.73 m(2)) and group 2 (42.8-76.4 mL/min/ 1.73 m(2)). All patients were treated with 0.75 to 1.3 g of racemic CYC as a 2-hour infusion and with 1 mg intravenous midazolam as a drug-metabolizing marker. CYC enantiomers and midazolam concentrations in plasma were measured by liquid chromatography/tandem mass spectrometry (LC/MS/MS). The following differences (Wilcoxon test, P <= .05) were observed between the (S)-(-) and (R)-(+) enantiomers: AUC(0-infinity) 152.41 vs 129.25 mu g.h/mL, CL 3.28 vs 3.89 L/h, Vd 31.38 vs 29.74 L, and t(1/2) 6.79 vs 5.56 h for group 1 and AUC(0-infinity) 167.20 vs 139.08 mu g.h/mL, CL 2.99 vs 3.59 L/h, and t(1/2) 6.15 vs 4.99 h for group 2. No differences (Mann test, P <= .05) were observed between groups 1 and 2 in the pharmacokinetic parameters of both enantiomers. No significant relationship was observed between midazolam clearance (2.92-16.40 mL/min.kg) and clearance of each CYC enantiomer. In conclusion, CYC kinetic disposition is enantioselective, resulting in higher exposures of the (S)-(-) enantiomer in lupus nephritis patients, and the pharmacokinetic parameters of both enantiomers are not altered by the worsening of renal condition.

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Background/Aims: Transmethylation reactions and antioxidant metabolism are linked by transsulfuration, where homocysteine (Hcy) is converted to cysteine and reduced glutathione (GSH). Low protein intake can modulate the balance of this metabolic reaction. The aim of the present investigation was to study the effect of a low-protein diet on Hcy metabolism by monitoring levels of the amino acids involved in these pathways, and relating these levels to GSH levels and lipid peroxidation in rats. Methods: Sixteen rats were divided into 2 groups: control (C; standard AIN-93 diet, 20% protein) and low-protein diet (LPD; 8% protein diet). Rats in both groups were placed on the diets for 28 days. Results: A significant reduction (p < 0.05) in plasma Hcy concentration was found in LPD rats (0.16 +/- 0.04 mu mol/mg protein) versus C rats (0.25 +/- 0.03 mu mol/mg protein). Methionine levels were not significantly different between the 2 groups (C: 1.24 +/- 0.22 mu mol/mg protein; LPD: 1.03 +/- 0.27 mu mol/mg protein). A significant reduction (p ! 0.05) in hepatic GSH concentrations (C: 44 8 10 mu mol/mg protein; LPD: 17.4 +/- 4.3 mu mol/mg protein) was accompanied by an increase in lipid peroxidation (C: 0.13 +/- 0.01 mu mol/mg protein; LPD: 0.17 +/- 0.02 mu mol/mg protein; r = -0.62, p < 0.01). Conclusion: Hcy levels were reduced under a low-protein diet, resulting in modulated methyl balance and reduced GSH formation leading to increased susceptibility of hepatic cells to oxidative events. Copyright (C) 2009 S. Karger AG, Basel

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Although there is no consensus about the use of glucose and thiamine for the treatment of acute ethanol intoxication, this is a routine practice in many countries. Our objective was to determine the efficacy of this treatment and the changes it causes in the antioxidant status of the liver. Male Wistar rats were intoxicated with an ethanol dose of 5 g/kg and divided into three groups: ethanol (EtOH; untreated), EtOH+G (treated with glucose), and EtOH+B1 (treated with thiamine). Blood and urinary ethanol as well as hepatic malondialdehyde, reduced glutathione and vitamin E were determined in all animals. Blood alcohol levels did not differ between groups, although urinary excretion was about four times higher in the group treated with thiamine (EtOH+B1). The malondialdehyde, reduced glutathione and vitamin E values used here as parameters of the antioxidant system of the liver showed improvement for the thiamine-treated group (EtOH+B1). Treatment with glucose or thiamine was ineffective in reducing blood alcohol levels in rats with acute ethanol intoxication. However, the beneficial effect of thiamine as an antioxidant for ethanol metabolism was demonstrated. Further investigations are necessary to clarify the urinary excretion of ethanol reported here for the first time and the possibility of using thiamine as an antioxidant in situations of chronic alcohol use.

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The aim of the present study was to examine the effects of creatine supplementation on liver fat accumulation induced by a high-fat diet in rats. Rats were fed 1 of 3 different diets for 3 wk: a control liquid diet (C), a high-fat liquid diet (HF), or a high-fat liquid diet supplemented with creatine (HFC). The C and HF diets contained, respectively, 35 and 71% of energy derived from fat. Creatine supplementation involved the addition of 1% (wt:v) of creatine monohydrate to the liquid diet. The HF diet increased total liver fat concentration, liver TG, and liver TBARS and decreased the hepatic S-adenosylmethionine (SAM) concentration. Creatine supplementation normalized all of these perturbations. Creatine supplementation significantly decreased the renal activity of L-arginine:glycine amidinotransferase and plasma guanidinoacetate and prevented the decrease in hepatic SAM concentration in rats fed the HF diet. However, there was no change in either the phosphatidylcholine:phosphatidylethanolamine (PE) ratio or PE N-methyltransferase activity. The HF diet decreased mRNA for PPAR as well as 2 of its targets, carnitine palmitoyltransferase and long-chain acylCoA dehydrogenase. Creatine supplementation normalized these mRNA levels. In conclusion, creatine supplementation prevented the fatty liver induced by feeding rats a HF diet, probably by normalization of the expression of key genes of beta-oxidation. J. Nutr. 141: 1799-1804, 2011.

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Objective. The relationship of multipotent mesenchymal stromal cells (MSC) with pericytes and fibroblasts has not been established thus far, although they share many markers of primitive marrow stromal cells and the osteogenic, adipogenic, and chondrogenic differentiation potentials. Materials and Methods. We compared MSCs from adult or fetal tissues, MSC differentiated in vitro, fibroblasts and cultures of retinal pericytes obtained either by separation with anti-CD146 or adhesion. The characterizations included morphological, immunophenotypic, gene-expression profile, and differentiation potential. Results. Osteogenic, adipocytic, and chondrocytic differentiation was demonstrated for MSC, retinal perivascular cells, and fibroblasts. Cell morphology and the phenotypes defined by 22 markers were very similar. Analysis of the global gene expression obtained by serial analysis of gene expression for 17 libraries and by reverse transcription polymerase chain reaction of 39 selected genes from 31 different cell cultures, revealed similarities among MSC, retinal perivascular cells, and hepatic stellate cells. Despite this overall similarity, there was a heterogeneous expression of genes related to angiogenesis, in MSC derived from veins, artery, perivascular cells, and fibroblasts. Evaluation of typical pericyte and MSC transcripts, such as NG2, CD146, CD271, and CD140B on CD146 selected perivascular cells and MSC by real-time polymerase chain reaction confirm the relationship between these two cell types. Furthermore, the inverse correlation between fibroblast-specific protein-1 and CD146 transcripts observed on pericytes, MSC, and fibroblasts highlight their potential use as markers of this differentiation pathway. Conclusion. Our results indicate that human MSC and pericytes are similar cells located in the wall of the vasculature, where they function as cell sources for repair and tissue maintenance, whereas fibroblasts are more differentiated cells with more restricted differentiation potential. (C) 2008 ISEH - Society for Hematology and Stem Cells. Published by Elsevier Inc.

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The objective of the present study was to analyze hepatic mitochondrial function in patients with familial amyloidotic polyneuropathy (FAP) undergoing cadaveric donor orthotopic liver transplantation. From February `2005 to May 2007, eight patients with FAP, ranging in age from 34 to 41 years and with Model for End-Stage Liver Disease scores ranging from 24 to 29. Underwent orthotopic transplantation using a liver from a deceased donor by the piggyback method. Immediately before beginning the recipient hepatectomy in a patient with FAP, a biopsy was obtained for analysis of mitochondrial function (FAP group). The control group consisted of 15 patients undergoing hepatic surgery to treat small tumors of the liver. Mitochondrial respiration was determined on the basis of oxygen consumption by energized mitochondria using a polarographic method. The membrane potential of the mitochondria was determined spectrofluorometrically. Data were analyzed statistically by the Mann-Whitney test, with the level of significance set at 5%. State 3 and 4 values, respiratory control ratio, and membrane potential were 47 +/- 8 versus 28 +/- 10 natoms O/min/mg protein (P <.05); 14 +/- 3 vs 17 +/- 7 nat.O/min/ mg.prot.mit. (P >.05); 3.6+/- .5 vs 1.7 +/- 0.7 (P <.05); and 135 +/- 5.2 vs 135 +/- 6 mV (P >.05) for control versus FAP patients, respectively, demonstrating a decreased energy status of the liver in FAP.

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In the present study, BALB/c mice were used to develop a model for the hepatic injury associated to dengue infection. Histological analysis after subcutaneous inoculation with a low viral dose of dengue-2 virus showed Kupffer cell hyperplasia and an increased inflammatory cellular infiltrate next to the bile ducts on days 5, 7 and 14 post-inoculation, mainly characterized by the presence of mononuclear cells. The liver mRNA transcription level of IL-1 beta was highest on the 5th day post-infection (p.i.) and decreased by the 21st day, TNF-alpha showed a peak of mRNA transcription after 14 days p.i. coinciding with the regression of cellular infiltrates and elevated expression of TGF-beta mRNA. Serum AST and ALT levels were slightly elevated at 7 and 14 days post-infection. Dengue-2 RNA levels were undetectable in the liver on any of the days following inoculation. Our observations suggest that, as it is true for humans, the animals undergo a transient and slight liver inflammation, probably due to local cytokine production and cellular infiltration in the liver. (C) 2010 Elsevier Inc. All rights reserved.

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Oxidative stress and lipid peroxidation, associated with ethanol, are considered important pathogenic mechanisms in the formation of hepatic steatosis. The objective of the present study was to assess the effects of supplementation with lecithin and vitamin E on the oxidatives stress and hepatic steatosis induced in rats by chronic ethanol consumption. Fifty-two Wistar rats were divided into 4 experimental groups: control (AIN-93 diet), ethanol group (control diet plus a 20% hydroalcoholic solution), ethanol + vitamin E group (addition of 0.6% vitamin E to the diet plus a 20% hydroalcoholic solution); ethanol + soy lecithin group (addition of 5 % soy lecithin to the diet plus a 20% hydroalcoholic solution). At the end of 4 weeks the animals were sacrificed. The results showed a significantly smaller number of animals (p < 0.05) classified as having a low degree of steatosis in the ethanol + vitamin E group and ethanol + soy lecithin group compared to the ethanol group. In addition, the ethanol + soy lecithin group had a significantly lower concentration of hepatic fat (p < 0.05) than the ethanol group. A significant reduction of hepatic TBARS concentration (p < 0.05) was detected in the ethanol + vitamin E group compared to the ethanol group. Hepatic carbonyl concentration was significantly lower in the ethanol + soy lecithin group. However, hepatic GSH was significantly lower in the ethanol + vitamin E and ethanol + soy lecithin groups compared to the control group. In conclusion, supplementation with lecithin and vitamin E attenuated the hepatotoxic effects of chronic ethanol intake and contributed to a reduction of the progression of steatosis status.

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Rationale Sepsis is a leading cause of death in the intensive care unit, characterized by a systemic inflammatory response (SIRS) and bacterial infection, which can often induce multiorgan damage and failure. Leukocyte recruitment, required to limit bacterial spread, depends on phosphoinositide-3 kinase gamma (PI3K gamma) signaling in vitro; however, the role of this enzyme in polymicrobial sepsis has remained unclear. Objectives: This study aimed to determine the specific role of the kinase activity of PI3K gamma in the pathogenesis of sepsis and multiorgan damage. Methods. PI3K gamma wild-type, knockout, and kinase-dead mice were exposed to cecal ligation and perforation induced sepsis and assessed for survival; pulmonary, hepatic, and cardiovascular damage; coagulation derangements; systemic inflammation; bacterial spread; and neutrophil recruitment. Additionally, wild-type mice were treated either before or after the onset of sepsis with a PI3K gamma inhibitor and assessed for survival, neutrophil recruitment, and bacterial spread. Measurements and Main Results: Both genetic and pharmaceutical PI3K gamma kinase inhibition significantly improved survival, reduced multiorgan damage, and limited bacterial decompartmentalization, while modestly affecting SIRS. Protection resulted from both neutrophil-independent mechanisms, involving improved cardiovascular function, and neutrophil-dependent mechanisms, through reduced susceptibility to neutrophil migration failure during severe sepsis by maintaining neutrophil surface expression of the chemokine receptor, CXCR2. Furthermore, PI3K gamma pharmacological inhibition significantly decreased mortality and improved neutrophil migration and bacterial control, even when administered during established septic shock. Conclusions: This study establishes PI3K gamma as a key molecule in the pathogenesis of septic infection and the transition from SIRS to organ damage and identifies it as a novel possible therapeutic target.

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The prevalence of cigarette smoking (CS) is increased among obese subjects, who are susceptible to develop nonalcoholic fatty liver disease (NAFLD). We investigated the hepatic effects of CS in control and obese rats. Control and obese Zucker rats were divided into smokers and nonsmokers (n = 12 per group). Smoker rats were exposed to 2 cigarettes/day, 5 days/week for 4 weeks. The effects of CS were assessed by biochemical analysis, hepatic histological examination, immunohistochemistry, and gene expression analysis. Phosphorylation of AKT and extracellular signal-regulated kinase (ERK) and quantification of carbonylated proteins were assessed by western blotting. As expected, obese rats showed hypercholesterolemia, insulin resistance, and histological features of NAFLD. Smoking did not modify the lipidic or glucidic serum profiles. Smoking increased alanine aminotransferase serum levels and the degree of liver injury in obese rats, whereas it only induced minor changes in control rats. Importantly, CS increased the histological severity of NAFLD in obese rats. We also explored the potential mechanisms involved in the deleterious effects of CS. Smoking increased the degree of oxidative stress and hepatocellular apoptosis in obese rats, but not in controls. Similarly, smoking increased the hepatic expression of tissue inhibitor of metalloproteinase-1 and procollagen-alpha2(I) in obese rats, but not in controls. Finally, smoking regulated ERK and AKT phosphorylation. The deleterious effects of CS were not observed after a short exposure (5 days). Conclusion: CS causes oxidative stress and worsens the severity of NAFLD in obese rats. Further studies should assess whether this finding also occurs in patients with obesity and NAFLD. (HEPATOLOGY 2010;51:1567-1576.)

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Association between insulin resistance (IR) and non-alcoholic fatty liver disease (NAFLD) has been reported. This prompted us to evaluate the power of the insulin sensitivity index (ISI) in association with IGFBP-1 to identify IR early in obese children/adolescents. OGTT was performed in 34 obese/overweight children/adolescents. Glucose, insulin and IGFBP-1 were measured in serum samples and ISI was calculated. Considering the presence of three or more risk factors for IR as a criterion for IR, ISI <4.6 showed 87.5% sensitivity and 94.5% specificity in diagnosing IR. IGFBP-1 was lower in the group with ISI <4.6 (p <0.01). In this group, three patients had higher than expected IGFBP-1, suggesting hepatic IR, while three patients with ISI >4.6 showed very low IGFBP-1 levels. Conclusion: ISI <4.6 is a good indicator of early peripheral IR and, associated with IGFBP-1, can identify increased risk of hepatic IR. Low IGFBP-1 levels among non-IR children may indicate increased portal insulin levels.