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Query: UMLS:C0023890 (cirrhosis)
 42,195 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Patients suffering from hepatic cirrhosis develop renal tubular acidosis when subjected to an acid overload. This is characterised by a fall in plasma pH and bicarbonate and by inability of the kidney to lower urine pH and to excrete a sufficient quantity of protons in the form of titratable acidy and ammonia. This disturbance is difficult to explain. It may form part of the picture of the classical functional renal insufficiency of the cirrhotic and may be a particular result of altered renal haemodynamics. Detected by the acidification test, this abnormality may be demonstrated in the absence of any other involvement of renal function. The severity of this renal tubular acidosis would appear to be related to the degree of hepatic disease.
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PMID:[Latent renal tubular acidosis of the cirrhotic patient. Study of urinary excretion of protons and sodium]. 0 69

This contribution presents data from the literature as well as our own results concerning the mechanisms of hepatic encephalopathy (HE). 1. Blood chemistry: In patients with liver cirrhosis, the plasma levels of ammonia, phenylalanine, tyrosine, phenolic acids, and octopamine correlated with the stages of HE. Methionine and free tryptophan concentrations were increased only in stages 2-4. Further, branched chain amino acids were below the normal range. Experimental findings in animals elucidated some mechanisms of these changes. 2. Effects of administered substances: With ammonia, methionine, methanethiol, tryptophan, phenolic substances, and fatty acids central nervous disturbances were observed. 3. Interactions: Anemia, methanethiol, and fatty acids favored ammonia toxicity. Alkalosis diminished cerebral symptoms. 4. Neurotransmitters: HE was accompanied by an enhanced turnover of serotonin and by increased amounts of false neurotransmitters (like octopamine) in the brain. 5. Oxydative brain metabolism: Disorders of cerebral oxygen and glucose utilization were mainly documented in cases of long term HE with EEG alterations. 6. Structural changes of the brain: Most of them are irreversible.
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PMID:[Pathogenesis of hepatic encephalopathy (author's transl)]. 1 66

Tyrosine (Tyr), tyrosine hydroxylase (TH), tryptophan (Trp), serotonin (5-HT), and 5-hydroxyindole acetic acid (5-HIAA) were assayed spectrofluorometrically and radioenzymatically in various regions of post-mortem brains of human patients with hepatic, uremic, and diabetic coma, liver cirrhosis without coma, and hepatic coma treated with parenteral administration of L-valine, a branched-chain amino acid. The results were as follows: In both hepatic and diabetic coma Tyr was increased as compared to non-comatose cirrhosis and controls, while TH acitivity was within normal limits, indicating sufficient oxygen supply of the brain in both types of coma. Brain DA showed a mild decrease in all types of metabolic coma. Brain Trp was not considerably changed in non-comatose cases of liver cirrhosis and after L-valine treatment of hepatic encephalopathy, but was significantly increased in hepatic coma, with highest elevation in the brainstem tegmentum. Both 5-HT and 5-HIAA were not significantly changed in non-comatose cirrhosis, while a general increase with prevalence for the brainstem was obvious in all types of metabolic coma. After L-valine treatment of hepatic coma, 5-HT levels were usually decreased below control values, while 5-HIAA levels were at or below controls. These results in human post-mortem brains confirm previous CSF and brain findings in experimental and human hepatic and uremic encephalopathies, indicating derangement of brain monoamine neurotransmitter metabolism which is attributed to imbalance of aromatic and branched-chain amino acids in plasma and brain. Increased cerebral 5-HT turnover, particularly in the ascending serotonergic brainstem systems, due to derangement of brain uptake of Trp is suggested to represent an important biochemical substrate of disorders of consciousness in hepatic failure and other types of metabolic encephalopathies. Clinical improvement of hepatic encephalopathy and of the underlying neurotransmitter derangements by administration of L-valine and the possible role of this competitive amino acid on intermediary metabolism and ammonia detoxification are discussed.
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PMID:Brain monoamines in hepatic encephalopathy and other types of metabolic coma. 3 73

It is proposed that hyperammonaemia in liver cirrhosis or after portacaval shunt contributes to plasma neutral aminoacid imbalance and to increased activity of the blood-brain neutral amino-acid transport system. Plasma neutral aminoacid concentrations are deranged, partly, but not completely, because ammonia stimulates glucagon secretion; a high rate of gluconeogenesis and hyperinsulinaemia follow. Brain uptake of neutral aminoacids rises because ammonia stimulates brain-glutamine synthesis, which results in rapid exchange of brain glutamine for plasma neutral aminoacids. Hyperammonaemia therefore contributes to encephalopathy indirectly, by raising the brain concentration of neutral aminoacids which after neurotransmitter metabolism, rather than directly, by toxic effects on neuronal metabolism.
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PMID:Hyperammonaemia, plasma aminoacid imbalance, and blood-brain aminoacid transport: a unified theory of portal-systemic encephalopathy. 9 Aug 64

Proline metabolism was prospectively evaluated in patients with surgical sepsis, cirrhosis, and elective surgical procedures. Significant correlations were found in the septic patients. Proline levels were an excellent indicator of mortality and correlated positively with lactate levels. Lactate and proline were inversely related to total peripheral resistance and oxygen consumption. In septic patients who expired: the metabolites involved in the hepatic pathways of proline degradation were elevated in proportion to proline; lactate, glutamate and proline were directly related to pyruvate; lactate/pyruvate ratios were constant; proline, glutamate, ammonia, ornithine, lactate and pyruvate levels were inversely proportional to oxygen consumption and total peripheral resistance. The primary defects in sepsis seem to be metabolic; there are very strong correlations in time between physiology and metabolism; the metabolic abnormality seems to be a progressive energy-fuel deficit, possibly from a progressive inhibition of substrate entry into the Krebs cycle.
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PMID:Proline metabolism in sepsis, cirrhosis and general surgery. The peripheral energy deficit. 11 5

The clinical picture of liver disease in endemic areas of Schistosomiasis mansoni differs in many ways from that observed in alcoholic and other types of cirrhosis. In hepatosplenic schistosomiasis there is predominance of the clinical manifestations of portal hypertension, e.g., bleeding esophageal varices, while ascites, jaundice, and hepatic precoma or coma are much less common. Ammonia tolerance is usually normal and helps explain the low mortality rate during bleeding. Of special interest is the observation of a high incidence of persistent hepatitis B surface antigenemia among patients with hepatosplenic schistosomiasis, suggesting increased susceptibility of such patients to the development of virus-induced chronic active hepatitis.
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PMID:Clinical aspects of hepatosplenic schistosomiasis: a contrast with cirrhosis. 12 11

A mixture with essential and nonessential amino acids high in branched chain amino acids and low in aromatic amino acids (Fischer solution), and another synthetic mixture of branched chain amino acids containing 3 amino acids associated with the urea cycle (Hep-OU) were infused to control subjects and patients with severe hepatic disease. Alterations in serum aminograms, blood ammonia levels and electroencephalograms following the infusion were studied and compared with those obtained by a commercially available amino acid mixture. Short-term or continuous infusion of a commercially available amino acid solution to cirrhotic patients caused an increase in methionine, phenylalanine and tyrosine and a decrease in branched chain amino acids. These post-infusion results were similar to the patterns seen in hepatic encephalopathy. In cirrhotic patients, infusion of Fischer solution which contains small quantities of methionine and phenylalanine produced an increase in the concentrations of these 2 amino acids, probably because of impaired utilization by the injured liver. No marked alterations in serum aminograms, however, were observed in cirrhotic patients either immediately after, or 3 h after, the end of the Hep-OU infusion. Reduction of methionine, tyrosine and phenylalanine levels and elevation of the molar ratio of (valine + leucine + isoleucine)/(phenylalanine + tyrosine) were significant. The infusion of Hep-OU to patients with liver cirrhosis or subacute hepatitis resulted in clinical and neurological improvements and the restoration of the molar ratio of branched chain amino acids/aromatic amino acids.
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PMID:An approach to nutritional therapy of hepatic encephalopathy by normalization of deranged amino acid patterns in serum. 15 28

The activities of urea-cycle enzymes were measured in liver biopsies of patients suffering from chronic-persistent hepatitis (CPH), chronic-active hepatitis (CAH) and liver cirrhosis. Most of the activities of urea-cycle enzymes did not differ in the case of CPH as compared to controls. Chronic-active hepatitis and liver cirrhosis are associated with a significant (p less than 0.05) decrease of enzyme activity as compared to normal persons. Most of the urea-cycle enzymes are significantly decreased in patients with CAH in comparison with CPH. No significant differences can be demonstrated in the case of CAH as compared to patients with complete cirrhosis. In conclusion, progression of chronic liver disease is associated with increasing alterations of enzyme activities catalyzing a liver specific metabolic pathway. The decrease of the activities of the key enzymes of the urea cycle (Carbamylphosphate-Synthetase and Arginino-succinate-Synthetase) is nearly identical both in CAH and liver cirhosis, although CAH may be a reversible disease. Therefore, marked alterations in the metabolic pathway of ammonia detoxification seem to preceed the histological manifestation of irreversible liver damage.
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PMID:Activities of urea-cycle enzymes in chronic liver disease. 22 5

In 75 cases of histologically verified liver cirrhosis the plasma amino acids were determined by ion exchange chromatography and the results were correlated with different liver function tests as prothrombin time, pseudocholinesterase, serum albumin, GOT, bilirubin and venous ammonia. Out of these parameters prothrombin time, pseudocholinesterase and serum albumin significantly correlated with the sum of branched-chain amino acids and with the Fischer's quotient (molar ratio of branched-chain and aromatic amino acids). Methionin and aromatic amino acids inversely correlated with these parameters, additionally methionin positively correlated with bilirubin and GOT. By comparing plasma amino acid levels in cirrhotics without and with hepatic encephalopathy (grade 3 or 4) no significant differences were found. "Fischer's quotient" showed an overlap in patients with and without encephalopathy. Therefore the precipitation of hepatic encephalopathy is not fully explained by the changes in plasma amino acids. Therapeutic administrations of specially mixtures of amino acids with a high content in branched-chain and a low content in aromatic amino acids correct the plasma amino inbalance for a short time and improves hepatic encephalopathy.
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PMID:Plasma amino acids in hepatic encephalopathy. 29 Jul 44

In a double-blind, randomized study the efficacy of lactulose was compared with neomycin-sorbitol in 45 episodes of acute nitrogenous portal-systemic encephalopathy (PSE) induced by dietary protein, azotemia, or gastrointestinal hemorrhage. All patients had underlying cirrhosis, and at the time of randomization had encephalopathy of at least grade 2 severity and arterial ammonia concentrations greater than 150 microgram/100 ml. Two thirds of the patients in each group returned to normal mental status and more than 80% in each group showed at least one grade improvement in mental state. In addition, there was equivalent improvement in asterixis, in the performance of the Number Connection Test, in the electroencephalographic pattern, and in arterial ammonia concentration. The principal difference between the two groups was a greater reduction in stool pH after lactulose therapy than after neomycin-sorbitol therapy. One patient randomized to neomycin-sorbitol had to be withdrawn from the study because of persistent vomiting related to the administration of the medication. Otherwise there were no complications attributable to therapy in either group. These data suggest that neomycin-sorbitol and lactulose are equally effective in the treatment of acute nitrogenous portal-systemic encephalopathy.
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PMID:Neomycin-sorbitol and lactulose in the treatment of acute portal-systemic encephalopathy. A controlled, double-blind clinical trial. 35 73


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