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Query: UMLS:C0015695 (fatty liver)
 13,941 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Focal (irregular, partial) fatty infiltration of the liver may simulate neoplastic or other hypodense masses on CT. On the basis of previous observations of the phenomenon that differences in X-ray attenuation diminish with increasing energy of X-rays used, we performed a preliminary study to determine if dual-energy CT could be used to discriminate between fatty infiltration and hypodense liver masses. Dual-energy CT at 140 and 80 kVp was performed in 14 patients undergoing liver biopsy and in seven control subjects with presumedly normal liver. Attenuation measurements were taken, and the changes in attenuation between 140 and 80 kVp were calculated. The mean changes in attenuation were 3.5 H for normal liver (n = 7), 2.5 H for hypodense liver masses (n = 6), 13 H for fatty liver (n = 5), 0.3 H for fatty liver combined with hemochromatosis or hemosiderosis (n = 3), and 2 H for the spleen (n = 18). The change in attenuation increased as the fat content in the liver increased. Analysis of variance showed a statistically significant difference (p less than .001) between fatty liver and the other groups. A difference greater than 10 H was unique to fatty infiltration. These results suggest that dual-energy CT may help to differentiate focal fatty infiltration of the liver from low-density neoplastic or other lesions, but only if the iron content of the liver is not increased.
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PMID:Value of dual-energy CT in differentiating focal fatty infiltration of the liver from low-density masses. 189 25

We assessed the prevalence of previously unrecognized hemochromatosis among patients in whom diabetes mellitus was diagnosed after the age of 30 yr, and we evaluated the positive predictive value of biochemical screening tests for hemochromatosis in diabetic subjects. Thirty-eight of 572 patients screened (6.6%) had a serum ferritin level greater than 324 micrograms/L; 16 patients had normal levels on repeat testing. Four patients' serum ferritin levels fell to less than 400 micrograms/L. Seven of 18 patients with a persistently elevated serum ferritin level did not undergo a liver biopsy because of a recognized cause of hyperferritenemia (carcinoma, alcoholism, or systemic lupus erythematosus). The diagnosis of hemochromatosis seemed certain in 1 of 3 patients who were not biopsied for technical reasons. Of 8 patients biopsied, 2 had hemochromatosis, 4 had fatty liver, 1 had hemosiderosis, and 1 had a chronic inflammatory cell infiltrate with no iron deposition. Of 4 patients with a raised transferrin saturation level, 2 had raised serum ferritin levels and hemochromatosis, 1 had raised serum ferritin and hemosiderosis on liver biopsy, and 1 had a normal transferrin saturation level on repeat testing. Two of 3 cases of hemochromatosis had other clinical markers of the condition. Therefore, routine screening of diabetic patients for hemochromatosis is not necessary, because patients with hemochromatosis will often have other clinical features of the disease. When screening diabetic patients for hemochromatosis, it should be remembered that a persistently raised serum ferritin level has a low positive predictive value (16.6%) and that a normal transferrin saturation level does not exclude the diagnosis.
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PMID:Usefulness of biochemical screening of diabetic patients for hemochromatosis. 235 Oct 33

Patients with cirrhosis present a continuing diagnostic and therapeutic challenge. The status of their disease frequently changes, necessitating intensive serial evaluation. CT is an invaluable tool in the management of these patients because it can noninvasively provide vital information concerning liver size, contour, and occasionally hepatic parenchyma. More importantly, CT can demonstrate superficial and deep varices, assess the patency of the extrahepatic portal system, and detect other complications including ascites, hepatic steatosis, hemochromatosis, and hepatocellular carcinoma.
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PMID:Computed tomography in the evaluation of cirrhosis and portal hypertension. 298 57

The accidental finding of raised levels of serum aminotransferase levels may lead to extensive investigations of the liver in apparently healthy people. To identify diagnostic groups and their need for investigations, we have evaluated the results of all investigative procedures carried out in 149 asymptomatic patients with persistently raised serum levels of aminotransferases. Fatty liver was found in 64%. These patients often had a high body weight. A high alcohol intake and diabetes mellitus were also noted. Chronic active or persistent hepatitis was found in 20% of the patients. Six per cent had cirrhosis, 4% had alpha 1-antitrypsin deficiency, and 3.5% had hemochromatosis. Apart from ferritin, alpha 1-antitrypsin, and markers for hepatitis B, blood tests were of little value for distinguishing among different diagnostic groups. This was the case also for the imaging procedures, and neither liver scintigraphy nor ultrasonography was a reliable source of diagnostic information. The results of our study indicate that diagnosis in this group of patients cannot be made without liver biopsy.
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PMID:Liver investigation in 149 asymptomatic patients with moderately elevated activities of serum aminotransferases. 395 45

To test whether reduced hepatic uroporphyrinogen decarboxylase activity is a specific and intrinsic defect in porphyria cutanea tarda, we measured enzymatic activity in the livers of 17 patients with porphyria cutanea tarda, 12 "normal" control patients without liver disease, and 41 patients with other forms of porphyria, alcoholic liver disease, hemochromatosis, or chronic hepatitis. Enzyme activity in all the patients with porphyria cutanea tarda was lower than in the patients without this disease, except for one patient with alcohol-induced fatty liver. Reduction of hepatic iron stores by phlebotomy did not alter the enzymatic activity in porphyria cutanea tarda. We conclude that reduced hepatic uroporphyrinogen decarboxylase activity is a specific and intrinsic hepatic defect in porphyria cutanea tarda, but modulation of uroporphyrinogen synthesis by extrinsic factors is required for the full biochemical expression of the disease.
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PMID:Decreased hepatic uroporphyrinogen decarboxylase activity in porphyria cutanea tarda. 706 51

The aim of the present was to define prognosis and life expectancy in patients with chronic liver disease of different etiologies and to relate them to an age- and sex-matched normal population. After a follow-up of 15 years, life expectancy of 620 patients with chronic liver disease was retrospectively calculated and compared with an age- and sex-matched normal population. Among patients with cirrhosis, prognosis was dependent upon Child classification (P = 0.001). Patients with alcoholic cirrhosis and fatty liver disease were younger (P = 0.01) and had a lower life expectancy than patients with other causes of chronic liver disease (P = 0.004). Patients with hepatitis B and hepatitis C cirrhosis showed a comparable prognosis and a significantly lower life expectancy than the age- and sex-matched population. Cryptogenic and autoimmune liver diseases showed a comparable life expectancy but a significantly shorter life expectancy than the normal population. In patients with alpha 1-antitrypsin deficiency-associated cirrhosis, a high viral coinfection rate was found (P = 0.01). For patients with noncirrhotic hemochromatosis, prognosis was poorer than that for the age- and sex-matched population. In patients with asymptomatic primary biliary cirrhosis, chronic persistent hepatitis B, and alpha 1-antitrypsin deficiency without cirrhosis, life expectancy was equal to that of the normal population. Prognosis and life expectancy in chronic liver disease depend on stage, cause, and symptoms of chronic liver disease; age; and possibilities of treatment. In patients with hereditary liver disease, additional viral infection of alcohol abuse lead to a significant deterioration of life expectancy. Patients with alcoholic chronic liver disease have the poorest prognosis.
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PMID:Prognosis and life expectancy in chronic liver disease. 764 84

Asymptomatic patients with abnormal results on liver function test pose a diagnostic challenge. In general, determinations of routinely ordered tests of liver function are neither sensitive nor specific for liver disease. Fatty liver, alcohol-related liver damage and chronic viral hepatitis are the most common causes of abnormal liver function test results in asymptomatic patients. Causes of asymptomatic liver disease include hemochromatosis, Wilson's disease, drug toxicity, chronic autoimmune hepatitis, biliary cirrhosis, sclerosing cholangitis, alpha1-antitrypsin deficiency and sarcoidosis. The most efficient screening tests for liver damage are alanine transaminase, alkaline phosphatase and bilirubin. Repeat testing when results are abnormal, and use of ancillary tests, such as creatine phosphokinase or gamma-glutamyl-transferase, may confirm liver damage. Imaging studies help exclude biliary obstruction or neoplasm. Treatable illnesses should be ruled out. Three to six months of observation for progressive symptoms and liver dysfunction may follow. After the period of observation, further laboratory tests, a diagnostic liver biopsy and/or referral to gastroenterologist may be needed.
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PMID:Evaluating asymptomatic patients with abnormal liver function test results. 862 23

This article reviews the various disorders that result in abnormal iron and fat within the liver. MR techniques that detect and characterize fat and iron are discussed. Chemical shift images are useful in detecting intracellular lipid and can characterize diffuse hepatic steatosis as well as focal areas of fatty sparing and fatty infiltration. T2*-weighted gradient-echo sequences are useful in detecting hepatic iron. Typical imaging features of genetic hemochromatosis and hepatic iron from blood transfusions are described.
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PMID:MR imaging of diffuse liver disease. Hepatic fat and iron. 911 79

The definable causes of nonalcoholic steatohepatitis (NASH) include jejunoileal bypass surgery (JIB), other causes of rapid and profound weight loss in obese subjects, total parenteral nutrition, drugs, industrial toxins, copper toxicity, and disorders characterized by extreme insulin resistance. However, the etiopathogenesis in most cases of NASH appears multifactorial. Obesity, type 2 diabetes, and hypertriglyceridemia are often associated with hepatic steatosis, and although this does not invariably lead to NASH, the fatty liver is vulnerable to hepatocellular injury initiated by reactive oxygen species (ROS). It is critical to understand not only the triggers for hepatitis (injury and inflammation) in NASH but also how this is perpetuated as chronic liver disease. The present focus is on whether the biochemical processes that generate oxidative stress lead to hepatocyte injury and secondary recruitment of inflammation or whether inflammation is the primary mediator of liver cell injury. Insulin resistance is a reproducible pathogenic factor in NASH. It favors accumulation of free fatty acids in the liver and predisposes to oxidative stress by stimulating microsomal lipid peroxidases and by the direct effects of high insulin levels in decreasing mitochondrial beta-oxidation. CYP2E1 is normally suppressed by insulin but is invariably increased in the livers of patients with NASH. In rodent dietary models of steatohepatitis, CYP2E1 is the catalyst of microsomal lipid peroxidation, while in Cyp 2e1 nullizygous mice, CYP4A proteins are induced and function as alternative microsomal lipid peroxidases. Other studies implicate activation of peroxisome proliferator-activated receptor-alpha (PPAR alpha) as leading to NASH; PPAR alpha is a transcription factor that governs both microsomal (via CYP4A) and peroxisomal (beta-oxidation) pathways of lipid oxidation and ultimately production of ROS. Increased lipid peroxidation is a crucial difference between the livers of rodents with experimental NASH and those of ob/ob genetically obese mice that have uncomplicated steatosis. Administration of endotoxin, through the release of tumor necrosis factor-alpha (TNF-alpha), provokes liver inflammation with hepatocyte injury in the steatotic liver. This may be particularly relevant in JIB and has been suggested as a pathogenic mechanism in primary NASH. It has been proposed that inheriting one or more copies of the hemochromatosis gene, C282Y, promotes fibrotic progression in NASH because of increased hepatic iron deposition, but recent studies have failed to confirm this. The relationship between the severity of hepatitis in NASH and progression to cirrhosis implies that products of the inflammatory infiltrate play a role in fibrogenesis. In summary, NASH can be regarded as the hepatic consequence of the metabolic syndrome (or syndrome X). Attention should now shift from steatosis, a generally benign process that is less evident in the advanced stages of cirrhosis, to the mechanisms for hepatocellular injury, inflammation, and hepatic fibrosis. In particular, the genetic, molecular, and cellular factors that ordain and moderate fibrosis in the context of steatohepatitis will be of greatest relevance to effective therapy and clinical outcome.
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PMID:Etiopathogenesis of nonalcoholic steatohepatitis. 1129 94

Insulin sensitivity (euglycemic clamp, insulin infusion rate: 40 mU. m(-2). min(-1)) was studied in 30 subjects with biopsy-proven nonalcoholic fatty liver disease (NAFLD), normal glucose tolerance, and a BMI <30 kg/m(2). Of those 30 subjects, 9 had pure fatty liver and 21 had evidence of steatohepatitis. In addition, 10 patients with type 2 diabetes under good metabolic control and 10 healthy subjects were studied. Most NAFLD patients had central fat accumulation, increased triglycerides and uric acid, and low HDL cholesterol, irrespective of BMI. Glucose disposal during the clamp was reduced by nearly 50% in NAFLD patients, as well as in patients with normal body weight, to an extent similar to that of the type 2 diabetic patients. Basal free fatty acids were increased, whereas insulin-mediated suppression of lipolysis was less effective (-69% in NAFLD vs. -84% in control subjects; P = 0.003). Postabsorptive hepatic glucose production (HGP), measured by [6,6-(2)H(2)]glucose, was normal. In response to insulin infusion, HGP decreased by only 63% of basal in NAFLD vs. 84% in control subjects (P = 0.002). Compared with type 2 diabetic patients, NAFLD patients were characterized by lower basal HGP, but with similarly reduced insulin-mediated suppression of HGP. There was laboratory evidence of iron overload in many NAFLD patients, but clinical, histological, and biochemical data (including insulin sensitivity) were not correlated with iron status. Four subjects were heterozygous for mutation His63Asp of the HFE gene of familiar hemochromatosis. We concluded that NAFLD, in the presence of normoglycemia and normal or moderately increased body weight, is characterized by clinical and laboratory data similar to those found in diabetes and obesity. NAFLD may be considered an additional feature of the metabolic syndrome, with specific hepatic insulin resistance.
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PMID:Nonalcoholic fatty liver disease: a feature of the metabolic syndrome. 1147 47


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