Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023890 (cirrhosis)
 42,195 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Leptin is a cytokine peptide that decreases appetite and thereby food intake and increases energy expenditure. It is produced in fat cells, but recent animal experiments have shown expression of leptin in modified stellate hepatic cells. Because a change in circulating leptin in cirrhosis could be caused by an altered production rate, altered disposal rate, or both, the present study was undertaken to identify regions of leptin overflow into the blood stream and regions of leptin extraction. Patients with alcoholic cirrhosis (n = 16) and control patients without liver disease (n = 12) were studied during catheterization with elective blood sampling from different vascular beds. Blood samples for leptin determination (radioimmunoassay) were taken simultaneously from artery/hepatic vein, artery/renal vein, artery/iliac vein, and artery/cubital vein. Patients with cirrhosis had significantly increased circulating leptin (7.3 vs. control 2.6 ng/mL, P <.002) that correlated directly to ascitic-free body mass index (r = 0.71, P <.005). A significant renal extraction ratio of leptin was observed in control patients (0. 16) and in patients with cirrhosis (0.07), but the latter value was significantly lower than in the control patients (-44%, P <.05) and inversely correlated to serum creatinine (r = -0.60, P <.05). A significant, but equal, hepatosplanchnic extraction of leptin was observed in cirrhotic patients and control patients (0.08 vs. 0.07). In patients with cirrhosis a significant cubital venous-arterial difference in leptin was observed, but not in control patients. The iliac venous/arterial leptin ratio was significantly above 1.0 in both groups and of similar size (1.16 vs. 1.15), but a higher difference in concentration was found in the cirrhotic patients (+33%, P <.05). The spillover rates of leptin in cirrhotic patients may be even higher than estimated from the increased systemic veno-arterial gradients. In conclusion, the elevated circulating leptin in patients with cirrhosis is most likely caused by a combination of decreased renal extraction and increased release from subcutaneous abdominal, femoral, gluteal, retroperitoneal pelvic, and upper limb fat tissue areas. The hepatosplanchnic bed drained through hepatic veins could not be identified as a source of increased circulating leptin in cirrhosis, but a contribution by the portosystemic collateral flow cannot be excluded.
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PMID:Increased circulating leptin in alcoholic cirrhosis: relation to release and disposal. 1034 25

It is not known whether obesity increases the risk for hepatocellular carcinoma (HCC) simply because it promotes cirrhosis, a general risk factor for HCC, or via some other mechanism that operates independently of cirrhosis. If the latter occurs, then hepatocyte hyperplasia, an early event during the neoplastic process, might begin before liver cirrhosis develops. Genetically obese, leptin-deficient ob/ob mice are models for nonalcoholic fatty liver disease (NAFLD), a type of liver disease that is strongly associated with obesity and type 2 diabetes. Similar to obese, diabetic patients, ob/ob mice have an increased incidence of HCC. However, unlike humans with NAFLD, they rarely, if ever, develop cirrhosis spontaneously. To determine whether the noncirrhotic livers of ob/ob mice with NAFLD exhibit hepatocyte hyperplasia, parameters of proliferation and apoptosis were compared in adult ob/ob mice and their healthy litter mates. Adult ob/ob mice have an increase in liver mass relative to body mass. This hepatomegaly cannot be explained solely by lipid accumulation and is accompanied by significant increases in hepatocyte proliferative activity (as evidenced by increased Erk activation, cell-cycle related gene expression, bromodeoxyuridine incorporation, and hepatic DNA content) with concomitant inhibition of hepatocyte apoptosis (as evidenced by decreased numbers of apoptotic hepatocytes, induction of several antiapoptotic mechanisms, and decreased activation of procaspase 3). Thus, liver hyperplasia is evident at the earliest stage of NAFLD in ob/ob mice, which supports the concept that obesity-related metabolic abnormalities, rather than cirrhosis, initiate the hepatic neoplastic process during obesity.
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PMID:Hepatic hyperplasia in noncirrhotic fatty livers: is obesity-related hepatic steatosis a premalignant condition? 1143 35

Liver cirrhosis is often associated with malnutrition status, and while leptin, which reduces food intake, appears to contribute to it, there have been few detailed studies of serum leptin concentrations in cases of liver cirrhosis. We therefore measured serum leptin concentrations in liver cirrhosis and investigated its relationship with gender, body composition analysis, and the severity of liver dysfunction and the patterns of diurnal profiles in serum leptin. There were no significant differences between the serum leptin concentrations in the healthy controls and patients with liver cirrhosis. The serum leptin concentrations in liver cirrhosis cases were significantly higher in females than in males. Significant positive correlations were observed between the serum leptin and the body composition analysis data such as body mass index (BMI), arm circumference (AC), and triceps skin fold thickness (TSF). There was no correlations between BMI and arm muscle circumference (AMC). No changes in leptin levels were observed in association with the progression of liver dysfunction, according to the Child-Pugh classification. The diurnal profiles showed different patterns in liver cirrhosis and diabetes mellitus. In diabetes, a nocturnal rise was seen beginning around 21:00, but in liver cirrhosis, the rise in serum leptin started around 12:00, peaked at 13:00, and remained elevated until 03:00 in the morning. No associations were observed between the variations in serum leptin concentrations and variations in blood glucose or plasma insulin levels. In summary, serum leptin concentrations in liver cirrhosis are higher in women, positively correlated with the body composition analysis data, but not correlated with the severity of liver dysfunction. The diurnal profiles in serum leptin concentrations in liver cirrhosis also showed a different pattern from the profiles in diabetes with the values starting to increase earlier, during the daytime. Further study regarding the relation of leptin to nutrition and metabolic abnormalities in liver cirrhosis appears to be necessary.
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PMID:Serum leptin concentrations in liver cirrhosis: relationship to the severity of liver dysfunction and their characteristic diurnal profiles. 1167 5

In the past year, some relevant papers related to the diagnosis of malnutrition and its pathogenesis in cirrhosis have been published. The value of anthropometrics in the nutritional assessment of end-stage cirrhotic patients has been reinforced. Also, the role of bioelectrical impedance analysis in these patients has been redefined. Several papers have investigated the relationship between leptin and malnutrition in chronic liver disease, particularly the role of alcoholism in hyperleptinaemia, and the importance of protein-bound leptin in these patients. In other papers, the impact of both undernutrition and obesity on the outcome of liver transplantation has been investigated. Two randomized, controlled trials on enteral nutrition in liver disease have been published in this period. One of them deals with a clinical situation (i.e. severe alcoholic hepatitis) associated with a high mortality rate, whereas the second is the first controlled trial in the field of preoperative nutrition in liver transplantation. Finally, some papers provide further arguments in the dilemma of which route of nutrition (enteral or parenteral) is better in cirrhosis.
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PMID:Nutritional aspects of liver disease and transplantation. 1170 97

The role of leptin in anorexia associated with liver cirrhosis remains controversial. The aim of this study was to quantify the serum leptin level in patients with hepatocellular or cholestatic liver disease and to assess its relationship with serum insulin, body mass index, and serum lipoproteins. The study population included 30 women, 15 with chronic hepatocellular liver disease and 15 with primary biliary cirrhosis; severity of disease was determined by Child-Pugh and histological criteria, respectively. Ten healthy, age-matched women served as controls. Levels of serum leptin and insulin were determined by radioimmunoassay. Mean serum leptin level was significantly lower in the primary biliary cirrhosis group compared to both the control (P < or = 0.05) and the hepatocellular groups (P < or = 0.05). Serum leptin level strongly correlated with body mass index in the hepatocellular group (P < 0.0001) and the controls (P < 0.001), but not in the primary biliary cirrhosis group; it showed no correlation with severity of liver disease. A positive correlation was found between serum leptin and serum cholesterol (P = 0.02), low density lipoprotein (P = 0.01), and triglycerides (P = 0.04) in the hepatocellular group and in the controls between serum leptin and serum high density lipoproteins (P = 0.01). Serum leptin is low in patients with primary biliary cirrhosis. The combined findings of normal insulin response less insulin resistance, and lower serum leptin level in primary biliary cirrhosis compared to hepatocellular liver disease may indicate that serum leptin is merely a passive marker and not a cause of anorexia in liver disease.
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PMID:Alterations in serum leptin in chronic liver disease. 1183 22

Increased leptin levels in patients with liver cirrhosis are postulated to result in malnutrition and increased energy expenditure. Since cirrhotic patients show improved nutritional status after a transjugular intrahepatic portosystemic stent shunt (TIPS), it was the aim of this study to evaluate plasma leptin levels and their influence on nutritional status prior to and after the TIPS procedure. We evaluated plasma leptin levels, body mass index (BMI), Child-Pugh score and pertinent biochemical parameters in 31 patients (19 men and 12 women) with severe complications of liver cirrhosis (74% ethyltoxic men, 50% ethyltoxic in women), prior to and after TIPS. Nineteen cirrhotic patients without TIPS served as controls. In women ascitic-free BMI significantly increased (from 22.8 +/- 4.6 kg/m2 to 23.9 +/- 4.9; p = 0.004 three months after TIPS), whereas in men only a tendency toward higher values (26.1 +/- 4.7 vs. 26.7 +/- 4.4; p = 0.28) was found. Analysis of peripheral venous leptin concentrations before and three months after TIPS revealed a significant increase in women (11.9 +/- 8.8 ng/ml vs. 18.6 +/- 14.9; p = 0.009) and in men (7.7 +/- 6.2 ng/ml vs. 12.2 +/- 9.0; p = 0.005). In addition, the leptin-BMI ratio increase significantly in women and men three months after TIPS implantation (women 0.49 +/- 0.29 vs. 0.73 +/- 0.52; p = 0.017; men 0.28 +/- 0.22 vs. 0.43 +/- 0.28; p = 0.002). On the other hand, patients without TIPS implantation showed no significant alterations of BMI and peripheral venous leptin concentrations. After TIPS implantation in liver cirrhotic patients, leptin levels were increased and the nutritional status improved. Therefore, our analysis suggests that in patients with predominantly ethyltoxic liver cirrhosis, elevated leptin levels are not a major reason for poorer body composition.
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PMID:TIPS implantation raises leptin levels in patients with liver cirrhosis. 1461 51

Leptin is involved in the regulation of food intake and is mainly secreted by adipocytes. Major secretagogues are cytokines such as TNF-alpha or IL-1. Leptin in turn upregulates inflammatory immune responses. Elevated leptin serum levels have been detected in patients with liver cirrhosis, a disease frequently associated with elevated levels of circulating cytokines as well as hypermetabolism and altered body weight. Recently, leptin has been detected in activated hepatic stellate cells in vitro and an involvement of leptin in liver fibrogenisis has been suggested. The current study was designed to further clarify the role of leptin in liver disease by characterizing leptin and leptin receptor expression in the development and onset of experimental liver fibrosis. Liver fibrosis and cirrhosis was induced in rats by use of phenobarbitone and increasing doses of CCl (4). Leptin and leptin receptor mRNA expression was determined by semiquantitative RT-PCR, protein expression by Western blot analysis and localization of leptin and its receptor by immunohistochemistry. Normal liver tissue does not express leptin, but leptin receptor mRNA. Increasing levels of leptin mRNA were detected in fibrotic and cirrhotic livers correlated to the degree of fibrosis. Leptin receptor mRNA expression was not significantly altered in damaged livers. Increasing levels of leptin were detected in fibrotic and cirrhotic livers, whereas protein expression of the receptor remained unchanged. Throughout different stages of liver fibrosis, leptin immunoreactivity was localized in activated hepatic stellate cells only, whereas immunoreactivity for the receptor was mainly seen on hepatocytes. In conclusion, leptin is expressed at increasing levels in activated hepatic stellate cells in vivo, which may therefore be a source of increased leptin tissue and serum levels contributing to the pathophysiology and morphological changes of chronic liver disease.
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PMID:Expression of leptin and leptin receptor during the development of liver fibrosis and cirrhosis. 1475 66

Leptin is an adipocyte-derived hormone involved in the homeostasis of body composition. An imbalance in leptin regulation has been observed in patients with liver cirrhosis. We aimed to assess serum and ascitic leptin levels in a group of patients with decompensated liver cirrhosis and to evaluate the relationship of these levels with tumor necrosis factor alpha (TNF-alpha). We assessed both serum and ascitic fluid leptin levels in a series of 16 consecutive patients with liver cirrhosis. We calculated the body mass index (BMI) and assessed body fat (BF) of all patients by means of bioelectric impedence analysis. Leptin levels were analyzed in relationship to biochemical indexes, TNF-alpha levels, and body composition. None of the patients had spontaneous bacterial peritonitis. Both serum and ascites leptin levels were correlated with BMI and BF. On average, ascitic fluid leptin levels (13.1 +/- 10.9 ng/ml) were twice as high as serum levels (7.0 +/- 6.4 ng/ml), and the ascitic fluid/serum ratio of leptin was > 1 in all patients. Serum and ascites leptin levels were positively correlated (rS = 0.675, P = 0.009), while no correlation was observed between leptin and TNF-alpha levels, both in serum and in ascites. Serum and ascites TNF-alpha were not correlated. The ascitic fluid leptin levels of cirrhotic patients with sterile ascites are on average two times higher than circulating levels of this hormone. Noteworthily, they correlate significantly with body composition. These findings seem to suggest that in patients with decompensated liver cirrhosis, intraabdominal production of leptin may contribute to the metabolic picture.
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PMID:High ascitic fluid leptin levels in patients with decompensated liver cirrhosis and sterile ascites: relationship with TNF-alpha levels. 1510 70

Nonalcoholic fatty liver disease, frequently associated with obesity, can lead to nonalcoholic steatohepatitis (NASH) and cirrhosis. The pathophysiology of NASH is poorly understood, and no effective treatment is available. In view of a potential deleterious role for reactive oxygen species (ROS), we investigated the origin of ROS overproduction in NASH. Mitochondrial production of ROS and its alterations in the presence of antioxidant molecules were studied in livers from ob/ob mice that bear a mutation of the leptin gene and develop experimental NASH. N-acetyl-cysteine and the superoxide dismutase (SOD) mimics ambroxol, manganese [III] tetrakis (5,10,15,20 benzoic acid) (MnTBAP), and copper [II] diisopropyl salicylate (CuDIPS) were used to target different checkpoints of the oxidative cascade to determine the pathways involved in ROS production. Liver mitochondria from ob/ob mice generated more O(2)*- than those of lean littermates (P <.01). Ex vivo, all three SOD mimics decreased O(2)*- generation (P <.001) and totally inhibited lipid peroxidation (P <.001) versus untreated ob/ob mice. Those modifications were associated with in vivo improvements: MnTBAP and CuDIPS reduced weight (P <.02) and limited the extension of histological liver steatosis by 30% and 52%, respectively, versus untreated ob/ob mice. In conclusion, these data demonstrate deleterious effects of superoxide anions in NASH and point at the potential interest of nonpeptidyl mimics of SOD in the treatment of NASH in humans.
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PMID:Pivotal role of superoxide anion and beneficial effect of antioxidant molecules in murine steatohepatitis. 1512 56

The traditional concept of adipose tissue as a passive reservoir for energy storage is no longer valid because it has been demonstrated that adipose tissue is a complex, essential, and highly active metabolic and endocrine organ that not only responds to afferent signals from traditional hormone systems and the central nervous system (CNS), but also expresses and secretes factors with important endocrine functions. These factors include leptin and other cytokines. Adipose tissue is also a major site for metabolism of sex steroids and glucocorticoids. The important endocrine function of adipose tissue is emphasized by adverse metabolic consequences of both adipose tissue excess and deficiency. Adipose tissue excess, particularly in visceral compartment, is associated with insulin resistance, hyperglycemia, dyslipidemia, hypertension, and prothrombotic and proinflammatory states. Liver is one of the principal targets of lipid-associated damage by mechanisms that involve apoptosis activation by source of tumoral necrosis factor-alpha and caspase activation and liberation of oxygen-reactive species by oxidative stress and enzymatic chains such as P450, CYP2E1, and CYP3A4, resulting in a continuum involving non alcohol-related fatty liver, non-alcoholic steatohepatitis with or without fibrosis, and liver cirrhosis. This work presents an overview of endocrine functions of adipose tissue and its influence on mechanisms of liver damage.
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PMID:[Obesity and steatohepatitis. Histologic aspects]. 1564 70


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