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Query: UMLS:C0085584 (encephalopathy)
 18,178 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The uremic syndrome is multifactorial, and affects most tissues and organs. Disturbances in protein and amino acid metabolism may play important roles, especially in chronic uremia, either directly or by production of toxic metabolites, with resultant negative nitrogen (N) balance, muscle wasting, reduced protein synthesis, and characteristically abnormal intracellular free amino acid concentrations. There are also grossly abnormal amino acid levels in the plasma of uremic patients, e.g., increases in conjugated amino acids, high levels of several nonessential and low levels of essential amino acids. The ratios of tyrosine/phenylalanine and of valine/glycine are decreased. The low tryptophan levels may contribute to encephalopathy as a result of an imbalance in neurotransmitter synthesis. Citrulline is found in excess; the explanation is unresolved. There are elevated concentrations of the sulfur-containing amino acids: cystine, taurine, cystathionine, and homocysteine. Excess of the latter is implicated in the atherogenesis of renal failure. Disturbed metabolism and interorgan exchange of amino acids in the uremic state explains some of the abnormalities in tissue and plasma concentrations of individual amino acids. Enzymatic defects are involved in the disturbed metabolism of branched chain amino acids (BCAA), with possible antagonism among them, which impairs growth and amino acid utilization. Carbohydrate intolerance, associated with insensitivity of peripheral tissues to insulin and hyperinsulinemia, elicits decreased plasma BCAA. Protein synthesis rates in normal and pathological conditions are more closely related to the intracellular amino acid pool than to plasma amino acid levels. Concentrations of individual amino acids in the plasma pool are poor indicators of their intracellular concentrations. Muscle contains the largest pool of protein and free amino acids in the body. In chronic renal failure patients, the intracellular concentrations of valine, threonine, lysine, and carnosine are low. With low protein diets and in hemodialysis, serine, tyrosine, and taurine often are also low. The low taurine may be related to fatigue and to uremic cardiomyopathies. The commonly used amino acid supplements generally fail to correct the intracellular amino acid deficits. A "New Formula" has been developed to correct these intracellular amino acid abnormalities, and to supplement a low protein diet. It provides more valine than leucine, increased tyrosine and threonine, and less histidine, leucine, isoleucine, lysine, methionine, and phenylalanine than in formulas customarily used for patients with chronic renal failure. It is uncertain whether other ap
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PMID:Amino acid metabolism in uremia. 267 58

Transient severe hyperammonaemia developed in the absence of serious liver dysfunction in three patients being treated for acute leukaemia. The onset of the biochemical disturbance was abrupt and led rapidly to acute encephalopathy, fatal in two cases. In the third patient, prompt initiation of aggressive haemodialysis and intravenous sodium benzoate and sodium phenylacetate infusion successfully controlled plasma ammonium levels until they spontaneously resolved. The cause of the disorder remains to be determined, but urinary nitrogen partition studies suggest temporary impairment of ureagenesis in a catabolic setting as a major pathophysiological feature of this disorder. The absence of liver disease, the normal mitochondrial ultrastructure seen in two cases, and the plasma aminoacid profiles observed serve to distinguish this disorder from others such as Reye's syndrome.
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PMID:Transient idiopathic hyperammonaemia in adults. 286 37

This study compared the effect of a vegetable diet with an animal protein diet on various aspects of nitrogen metabolism to identify what components of the vegetable diet might be causing beneficial therapeutic effects in hepatic encephalopathy. Vegetable diets contained 4.5-fold greater amounts of fiber (56 +/- 3 g/day) and reduced amounts of methionine, tyrosine, and tryptophan. In 6 stable cirrhotic subjects without encephalopathy, vegetable diets caused a significant reduction in the urea production rate from 106 +/- 5 to 89 +/- 5 mg X kg-1 X 24 h-1 of urea nitrogen. This was mainly accounted for by a fall in urinary urea output. Vegetable diets also caused a fall in total urinary nitrogen, which was accounted for by the fall in urea nitrogen, and a comparable increase in fecal nitrogen from 12 +/- 2 to 28 +/- 5 mg X kg-1 X 24 h-1. The fecal bacterial fraction contained 63% of the increase in stool nitrogen. Most plasma amino acids, including methionine, tyrosine, phenylalanine, as well as total and free tryptophan, were unchanged. The effect of vegetable diets on nitrogen metabolism can be mainly accounted for by the increased intake of dietary fiber and increased incorporation and elimination of nitrogen in fecal bacteria.
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PMID:Effects of vegetable diets on nitrogen metabolism in cirrhotic subjects. 299 Oct 68

A prognostic study based on 127 untreated patients with hepatocellular carcinoma was undertaken to evaluate their survival time and to find clinical and biologic criteria which allow the selection of patients with a survival time longer than 60 days who could enter a therapeutic trial. Twenty-eight clinical and biologic variables were assessed using univariate and multivariate semiparametric regression (Cox's) models. Ten variables were isolated by univariate analysis. Multivariate analysis found a negative relationship between a survival time longer than 60 days and five of these variables; these variables were in decreasing order: encephalopathy, alcohol consumption, aspartate amino transferase (AST), blood urea nitrogen, and total bilirubin. Prevalence, positive, and negative predictive values of encephalopathy were 20%, 27.5%, and 97% respectively. When three other criteria: ASAT greater than four times the upper limit of the normal (N), blood urea nitrogen greater than N, and total bilirubin greater than 2N were added, their prevalence, positive, and negative predictive values were 72%, 89.7%, and 57.1% respectively. These results suggest that in countries where incidence of hepatocellular carcinoma is low and recruitment of patients difficult, absence of encephalopathy must be the only criterion for selection of patients with hepatocellular carcinoma in therapeutic trials; whereas, in countries with a high incidence of hepatocellular carcinoma the other criteria may be added.
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PMID:Prognostic factors in patients with hepatocellular carcinoma. Attempts for the selection of patients with prolonged survival. 303 3

Between March 1982 and September 1983, 40 inpatients (25 men and 15 women, mean age 53 years) with alcoholic cirrhosis and total serum bilirubin greater than or equal to 5 mg per dl were studied. Those with hepatocellular carcinoma, renal failure, hyponatremia, septicemia, spontaneous bacterial peritonitis, gastrointestinal bleeding, and hepatic coma were excluded. Patients were studied for 28 days. The two groups were offered an oral diet containing 40 kcal per kg per day. Patients in the supplementary parenteral nutrition group received 40 kcal per kg per day and 200 mg nitrogen per kg per day using a central catheter. The major endpoint was total serum bilirubin on Day 28. On admission, serum bilirubin was not significantly different in the two groups: oral group, 12.5 +/- 6.6 mg per dl; supplementary parenteral nutrition group, 12.3 +/- 8.5 mg per dl. On Day 28, serum bilirubin was lower in the supplementary parenteral nutrition group (2.5 +/- 1.4 mg per dl) than in the oral group (4.1 +/- 2.2 mg per dl) (p less than 0.02). Serum bilirubin was also lower in the supplementary parenteral nutrition group than in the oral group on Days 7, 14 and 21 (p less than 0.05). Analysis of covariance, considering serum bilirubin on admission and at randomization and time between admission and randomization, confirmed these results. On Day 28, anthropometric parameters, serum transferrin, prealbumin and retinol-binding protein were higher in the supplementary parenteral nutrition group, but the differences were not significant. Serum albumin was significantly lower in the supplementary parenteral nutrition group. The incidence of encephalopathy and sepsis was not significantly different between the two groups.
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PMID:A randomized clinical trial of supplementary parenteral nutrition in jaundiced alcoholic cirrhotic patients. 308 33

The effects of branched chain amino acid (BCAA)-enriched diets (fed for 7 days) on encephalopathy, plasma amino acid concentrations, aromatic amino acid turnover, and protein synthesis rates were determined in eight patients with alcoholic liver failure. Four patients were given the diet intravenously (iv group) (total amino acids, 60-80 g/day, BCAA content 51%, energy 2000 kcal/day) and four patients (NG group) were given a semi-elemental formulation via constant nasogastric (NG) infusion (amino acids 58 g, BCAA 43%, oligopeptides 19.5 g, energy 2000 kcal/day). The enteral diet was given at one-half strength for the first 3 days. A 10-hr constant infusion of [U-14C]phenylalanine tracer was used in four patients to measure aromatic amino acid (AA) turnover and rates of incorporation into various body proteins. Seven of the eight patients made a good clinical recovery, with reversal of encephalopathy within 3 days of dietary intervention. One became septicemic and deteriorated. While plasma bilirubin concentrations dropped, liver enzymes remained elevated. Mean nitrogen balance was negative at the beginning and positive at the end of the study, in both groups. Initial amino acid profiles demonstrated low plasma BCAA content and BCAA:AA ratios. Significant improvements occurred in the iv group by day 2 and in both groups by day 7. Isotope studies showed that, whereas aromatic amino acid oxidation remained unchanged, greater quantities were incorporated in whole body protein, albumin, transferrin, fibrinogen, and immunoglobulins.
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PMID:Enteral and parenteral branched chain amino acid-supplemented nutritional support in patients with encephalopathy due to alcoholic liver disease. 311 90

The etiology of malnutrition and the metabolic effect of aggressive nutritional support by enteral feeding were evaluated in patients with moderately severe alcoholic hepatitis. Among 21 patients presenting with jaundice, ascites, coagulopathy and low grade encephalopathy, the mean digestibilities (intake - fecal excretion/intake x 100) of total energy and fat were subnormal at 74.6 +/- 2.9 and 64.5 +/- 4.4%, respectively, and nitrogen balance was negative in half the patients with a mean value of +0.74 gm per day +/- 1.2. Based on initial ad libitum intake of hospital diet, patients were grouped as six patients with adequate caloric intake who underwent a repeated 3-day balance study to assess the effect of hospitalization (Group I) and eight anorectic patients who underwent a repeat balance study during constant nasoduodenal infusion of the liquid formula Isocal-HCN in an amount sufficient to provide 35 kcal per kg ideal body weight (Group II). During the initial phase of hospital tray diet, the mean digestibilities of energy, fat, protein and carbohydrate, and the mean nitrogen balance were similar in each group. The digestibilities of each diet constituent and nitrogen balance were similar in both phases of hospital tray diet in patients in Group I. On the other hand, the infusion of Isocal-HCN to patients in Group II resulted in significant increases over their baseline values in intakes of energy and protein and in digestibilities of energy, fat and protein, and in a 5-fold increase in nitrogen balance. Provision of essential nutrients by enteric infusion had no effect on fluid balance or degree of encephalopathy.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Metabolic effects of enteral formula feeding in alcoholic hepatitis. 311 52

Taurine is an important age- and compartment-specific part of the pool of free amino acids in all human tissues and fluids examined. Besides an active taurine transport system, the mechanisms to assure compartment-specific taurine-homeostasis in humans is presumably due to a compartment-specific taurine synthesis. By the identity of cysteine-sulfinic acid - and glutamate-oxalate transaminase as well as of cysteine-sulfinic acid - and glutamic acid decarboxylase taurine biosynthesis via cysteine-sulfinic acid shows direct metabolic relationship between biochemical pathway of cysteine-sulfinic acid and taurine on one side, and of the dicarbonic acid and their biological decarboxylates on the other side. In the parenteral and enteral nutrition of premature babies as well as of adults with portosystemic encephalopathy or with extreme thiamine deficiency, there is - besides an inconstant parallel of exogenous taurine supply and plasma taurine homeostasis - a constant parallel between definitely lowered plasma taurine concentrations and comparably distinct disturbance of the homeostasis of the dicarbonic acids and/or their biosynthetic products. A metabolic connection seems likely. The hypothesis of Sturman et al. in 1976 that taurine is an essential part of the human nutrition at least in the premature or full-term newborn phase of life could not be supported in the subsequent studies of different groups of authors - neither in relation to the nitrogen balance, childhood-development, hepatic cellular function, biliary-acid metabolism, intestinal fat absorption nor any organ-specific function. The nutritional value of taurine in humans still remains unclear in regard to specific physiologic as well as specific pathophysiologic phase of metabolism.
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PMID:[Taurine--recent views and importance for artificial feeding]. 313 85

A seventy-two-year-old man with hypertensive cerebral hemorrhage acutely developed severe headache, nausea, vomiting, agitation, and disorientation with abrupt rise in blood pressure on the sixth day after the onset. At that time, there were no remarkable changes in focal neurologic deficits, and repeated brain CT scans revealed a small hematoma located in the right basal ganglia without further enlargement or herniation. Blood chemistry and arterial gas analysis were within the normal ranges except for a slight rise in blood urea nitrogen. Similar episodes occurred three times within two days, and each time the cerebral symptoms disappeared in accordance with lowering of blood pressure by antihypertensive therapy. Complication of hypertensive encephalopathy was strongly suggested. The authors discuss the pathophysiology of this encephalopathy in relation to cerebral hemorrhage.
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PMID:Transient encephalopathy related to rapidly and markedly elevated blood pressure in acute stage of hypertensive cerebral hemorrhage--relationship to hypertensive encephalopathy--a case report. 317 64

In view of the putative involvement of calcium in uremic encephalopathy and the critical importance of this element in juvenile development, we examined the effect of temporary restriction of dietary calcium intake on serum chemistry and the quantitative electroencephalogram (Q.EEG) in unilaterally 3/4 nephrectomized juvenile male Sprague-Dawley rats. Animals were renally infarcted at 22-26 days of age (50-74 g) and placed on one of two isocaloric dietary regimens: powdered normal rat diet (ND, n = 25) or low calcium diet (LCD, n = 8) for 30 days. At this time, ND animals showed normal serum chemistries, whereas LCD rats were hypocalcemic and azotemic with significantly elevated blood urea nitrogen (BUN) and serum creatinine concentrations and reduced renal creatinine clearance values. All animals thereafter received ND for 25-34 further days, during which time chronic Q.EEG electrodes were implanted. At the end of the common ND feeding period, serum chemistry values were equal and normal in both groups. The average theta/alpha ratio (TAR) of the overnight Q.EEG was assessed for 3 days. We found that the TAR of previously LCD animals was significantly elevated compared with ND rats. This indicates an encephalopathic slowing of the background rhythm of these animals. We conclude that, following restoration of a transient uremic and hypocalcemic episode induced by LCD feeding, the Q.EEG background frequency of juvenile renally impaired rats was abnormally slow after 30 days of ND feeding.
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PMID:Juvenile hypocalcemia provokes persistent electroencephalographic change in renally compromised rats. 323 Feb 33


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