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

Chronic renal failure frequently causes uremic encephalopathy with impairment of different cognitive functions, but the pathophysiology of uremic encephalopathy is still unknown. We measured visually evoked event-related potentials (ERPs) in 33 neurologically asymptomatic patients before and after they underwent hemodialysis and compared their data with those of a strictly age-matched healthy control group. Before hemodialysis, the patients' P3 latency was significantly increased and P3 amplitude was significantly decreased as compared with that of the healthy control group. After hemodialysis, P3 latency of the patients showed a significant decrease (457+/-56 before and 438+/-54 ms after hemodialysis) and the P3 latency habituation during the ERP measurement was also significantly decreased. Patients with higher levels of blood urea nitrogen (BUN), creatinine, and uric acid performed better in ERP measurement than did patients with lower levels. Hemoglobin did not influence ERP latencies and amplitudes. Our data suggest that impaired cognitive processing can be disclosed by ERP even in neurologically asymptomatic chronic renal disease. Removal of uremic toxins by hemodialysis leads to an improvement in cognitive processing.
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PMID:Influence of end-stage renal failure and hemodialysis on event-related potentials. 950 13

Free radical-mediated injury is implicated in hypoxic-ischemic encephalopathy observed in neonates. We investigated in utero free radical production and injury following hypoxia-ischemia to premature fetal brain utilizing a rabbit model of acute placental insufficiency. Pregnant rabbits at 29 days gestation were randomized to uterine ischemia for 50 minutes (min) (hypoxia) or nonischemic controls. Fetal brains were obtained immediately after ischemia for oxidative and acute-injury markers or 24 hours (h) post-ischemia for histopathology. Nitrotyrosine formation, a marker of NO-derived species such as peroxynitrite, was observed only in hypoxic brains. Hypoxia resulted in a significant increase in nitrogen oxides, lipid peroxidation, and protein oxidation, with a concomitant decrease in total antioxidant capacity, compared with controls. Peroxynitrite addition to brain homogenate increased nitrogen oxides linearly (1:1), although protein carbonyls were unchanged. Concomitantly, in vitro cortical and hippocampal cell viability and ATP levels decreased, with an increase in brain edema in hypoxic brains. Fetuses delivered 24 h post-ischemia had increased hippocampal nuclear karyorrhexis on histology compared with controls. Antioxidant administration (ascorbic acid and Trolox) intraperitoneally ameliorated changes in cellular viability and brain edema. Acute fetal hypoxia-ischemia without reoxygenation results in increased nitrogen and oxygen free radical production that may cause brain injury. The merits of the described model are discussed.
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PMID:Sustained hypoxia-ischemia results in reactive nitrogen and oxygen species production and injury in the premature fetal rabbit brain. 963 Feb 34

Ornithine transcarbamylase (OTC) deficiency is an X-linked disorder of urea synthesis. Among females who carry a mutant OTC allele, there is a wide range of phenotypic variability, ranging from apparent normality to a severe onset and the resulting profound neurologic impairment observed in hemizygous males. This study was designed to define the phenotypic variability of OTC deficiency in ostensibly healthy carrier females and to compare them to noncarrier females from their own and other families. One hundred seventy-five women from 89 families participated in this study. Each completed a mailed questionnaire, allopurinol testing, and fasting plasma amino acid determinations. OTC carrier status was determined by pedigree analysis, allopurinol test results, and/or DNA mutation analysis. Overall, 79 women were identified as carriers of a mutant OTC allele (60 proband mothers, 19 relatives), and 96 women (32 proband mothers, 64 female relatives) were determined to be noncarriers. Comparison of biochemical phenotypes indicated that carriers and noncarriers do not differ in daily urinary creatinine excretion, but that carriers excrete significantly less urea nitrogen and total nitrogen, reflecting their significantly lower historically reported daily protein intake. Carriers had significantly higher levels of fasting plasma glutamine and alanine, and significantly lower levels of citrulline and arginine compared with noncarriers. Carriers and noncarriers reported similar demographic characteristics, anthropometric measurements, level of education, and medical and pregnancy histories. There was no indication of increased incidence of migraine headaches among carriers. Thus, we found no evidence that asymptomatic adult female OTC heterozygotes are at increased risk for previously unidentified health problems apart from an unknown risk for hyperammonemic encephalopathy as occurred in 3 of the carriers in this study. Because these episodes appear to be related to physiologic stress (fracture, parturition), it would seem medically prudent for carriers to be aware of this risk.
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PMID:The phenotype of ostensibly healthy women who are carriers for ornithine transcarbamylase deficiency. 985 2

Six enzyme defects of the urea cycle have been described. Ornithine transcarbamylase deficiency is the most frequent of these diseases. The cumulative frequency is 1:8000. Most patients become symptomatic in childhood, but onset of symptoms may occur later in childhood or even adulthood. The patients present with recurrent episodes of an unspecific acute encephalopathy, seizures and clouding of consciousness to a variable degree. Focal neurological signs such as hemiparesis, aphasia or ataxia may also occur. These episodes may be triggered by infection, protein overload or drugs. Diagnostic are increased blood ammonia levels. Characteristic patterns of plasma amino acids and the determination of orotic acid in the urine mostly discriminate the individual disorders. Further diagnostic steps include the allopurinol challenge test, liver or skin biopsy for measurement of enzyme activity and molecular genetic studies. Treatment requires restriction of protein intake, supplementation of arginine and activation of alternative pathways of nitrogen excretion with benzoate or phenylbutyrate. Untreated, the acute episode may be lethal. Long-term treatment improves the clinical outcome considerably. Urea cycle defects should be included in the differential diagnosis of any encephalopathy or coma of unclear origin, and blood ammonia should be determined early in the evaluation of such patients.
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PMID:[Enzyme defects of the urea cycle in differential acute encephalopathy diagnosis in adulthood. Diagnosis and current therapy concepts]. 1009 45

Critically ill patients are characterized by acute changes in their metabolism, which are described by the term 'hypermetabolism'. In combination with anorexia, hypermetabolism leads to a negative energy and nitrogen balance. Consequently, wound healing can be inhibited, resistance is reduced, and (multiple) organ failure can occur. With the aid of nutritional support these consequences can be counteracted. During hypermetabolism protein breakdown is increased, and it is necessary to supply extra protein in the diet of critically ill patients. The amino acid glutamine is an important source of energy for enterocytes, and extra glutamine can improve the protective function of the intestinal mucosa. Branched amino acids serve as energy source during the acute phase. Arginine can reduce symptoms of encephalopathy by improving the conversion of ammonia to urea. Extra arginine in the diet also improves resistance. Because of the increased energy demand, diets for critically ill patients should be rich in fat. Moreover, extra n-3 fatty acids can improve immune function. A diet supplemented with extra zinc seems warranted because of its beneficial effect on wound healing and its inhibitory effect on protein breakdown. The enteral route is preferred because it protects the mucosal barrier of the gut, and it is less expensive and easier than the parenteral route. An enteral diet for critically ill patients is presented. Various factors that determine the choice of technique for enteral feeding are discussed.
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PMID:[Enteral, nutritional support for critically ill patients]. 1048 74

Five cases that were referred to the Division of Transplantation at NYU School of Medicine for consideration for liver transplantation were discussed among a panel of hepatitis B and liver transplant experts. Opinions were obtained on the management at every stage of treatment of patients with the following initial information: Case one: young Asian woman in stage IV hepatic coma; intubated; prothrombin time (PT): 30 s; serum glutamic oxaloacetic transaminase (SGOT): 8,000 IU; total bilirubin: 25 mg/dL; hepatitis B surface antigen (HBsAg) positive. Case two: 70-yr-old woman, native of Greece; decompensated cirrhosis with encephalopathy; Child-Pugh Class C; HBsAg positive; hepatitis B surface antibody (HBsAb) negative; hepatitis B e antigen (HBeAg) positive; hepatitis B e antibody (HBeAb) negative; hepatitis B virus (HBV) DNA titer: 10,000. Case three: Muscular detective working full-time; cirrhosis; Child Pugh Class B; ascites controlled with spironolactone and furosemide; PT: 19s; HBsAg positive; HBsAb negative; HBV DNA titer: 50,000; low platelet count. Case four: 45-yr-old baker; cirrhosis and resectable 4-cm hepatoma; Child-Pugh Class B; PT: 16 s; Blood type O; United Network for Organ Sharing (UNOS) 2B; HBV DNA titer: 3,000. Case five: 40-yr-old Indian man; 300 pounds with massive ascites; Child Pugh Class C; PT: 17 s; HBsAg positive; HBV DNA titer: 22,000; transplanted with intra-operative hypotension; tacrolimus; graft functioning; HBIg 10,000 IU intra-operative and around the clock during the first post-operative week; required huge doses of hepatitis B immune globulin (HBIg) to maintain adequate HBsAb level; daily loss of 5 6 L of ascites fluid; post-operative day 8: anuric, blood urea nitrogen (BUN) 127, creatinine 3, mental status changes.
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PMID:Case studies in orthotopic liver transplantation for hepatitis B: a panel discussion. 1096 64

Hyperammonemia associated with inherited disorders of amino acid and organic acid metabolism is usually manifested by irritability, somnolence, vomiting, seizures, and coma. Although the majority of these patients present in the newborn period, they may also present in childhood, adolescence, and adulthood with failure to thrive, persistent vomiting, developmental delay, or behavioral changes. Persistent hyperammonemia, if not treated rapidly, may cause irreversible neuronal damage. After the diagnosis of hyperammonemia is established in an acutely ill patient, certain diagnostic tests should be performed to differentiate between urea cycle defects and other causes of hyperammonemic encephalopathy. In a patient with a presumed inherited metabolic disorder, the aim of therapy should be to normalize blood ammonia levels. Recent experience has provided treatment guidelines that include minimizing endogenous ammonia production and protein catabolism, restricting nitrogen intake, administering substrates of the urea cycle, administering compounds that facilitate the removal of ammonia through alternative pathways, and, in severe cases, dialysis therapy. Initiation of dialysis in the encephalopathic patient with hyperammonemia is indicated if the ammonia blood level is greater than three to four times the upper limit of normal. Hemodialysis is the most effective treatment for rapidly reducing blood ammonia levels. Continuous hemofiltration and peritoneal dialysis are also effective modalities for reducing blood ammonia levels. An improved understanding of the metabolism of ammonia and neurological consequences of hyperammonemia will assist the nephrologist in providing optimal care for this high-risk patient population.
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PMID:Hyperammonemia in urea cycle disorders: role of the nephrologist. 1132 92

Complete clinical examination covered 37 patients in various stages after acute occupational poisonings with pesticides (8 examinees), with explosive gases (9 subjects), with carbon oxide (3 examinees), with cadmium oxides (1 examinee), with nitrogen compounds (4 ones), with sulfurous gases (2 examinees), with organic solvents (10 subjects) including chlorinated hydrocarbons (2 subjects). Post-intoxication period appeared to include syndromes characteristic for each poison and corresponding to severity of acute state (from cephalgia to parkinsonism and thyrotoxicosis after acute poisoning with carbon oxide, organic neurologic signs and toxic hepatitis after acute poisoning with phosphorus organic compounds, cerebral asthenia after acute exposure to organic solvents, severe encephalopathy and toxic auditory and optic neuropathy after hydrogen sulfide). Inadequate medical rehabilitation and continuous occupational exposure induced deterioration in clinical signs and advanced post-intoxication syndromes.
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PMID:[Diagnostic problems of post-intoxication states]. 1150 30

The patient, a 78-year-old Asian male, was brought to the hospital because of acute shortness of breath that had progressively worsened over the course of the day. He complained of a nonproductive cough and claudication after walking 1 block. His past medical history was significant for mild renal insufficiency (serum creatinine 1.5--2.0 mg/dl), the etiology of which was never explored. Although there was a recent history of mild to moderate hypertension, at presentation his blood pressure was noted to be 240/118 mm Hg in both arms. His physical exam at the time of admission was remarkable for grade II hypertensive retinopathy, an S4 gallop, periumbilical systolic bruits, audible femoral arterial bruits and absent distal lower extremity pulses. Initial complete blood count, serum electrolytes and cardiac enzymes (including lactate dehydrogenase) were normal. His blood urea nitrogen and serum creatinine concentrations were 51 and 3.6 mg/dl, respectively, and his urinalysis showed 1+ protein (both by dipstick and sulfasalicylic acid) with a "benign" sediment (0--1 WBC/HPE, 1--2 RBCs/HPF) with occasional granular casts. His electrocardiogram, apart from demonstrating left ventricular hypertrophy with secondary ST-T wave abnormalities, showed no acute changes; his chest X-ray demonstrated cardiomegaly and pulmonary vascular congestion. He was intubated and subsequently treated with increasing parenteral doses of furosemide (40--240 mg) and a nitroglycerine drip (up to 15 mcg/min). Over the course of the first 48 h, his blood pressure was gradually lowered to 170/100 mm Hg. His urine output increased from 20 ml/h to 125/ml/h, and his respiratory status improved, allowing him to be extubated. In spite of adequate control of his blood pressure in the ensuing days (150--170/80--90 mm Hg), his renal function continued to deteriorate. Renal sonography (without Doppler) demonstrated a right kidney of 9.6 cm and a left kidney of 9.3 cm in length without evidence of hydronephrosis. Both kidneys were noted to be echogenic. Assays for antinuclear antibodies and antineutrophilic cytoplasmic antibodies were negative, and the patient's serum complement levels were normal. For several days after his admission, his serum creatinine gradually rose to 10.7 mg/dl, and hemodialysis was initiated for uremic encephalopathy. Because of the high index of suspicion for renal artery stenosis as the case of both his hypertension and renal failure, a renal angiogram was performed. It revealed a 90% occlusion of the right renal artery with ostial involvement and a 70% occlusion of the left renal artery; both kidneys had poor distal renal vasculature and there was marked atherosclerotic disease of the aorta. After being hemodialyzed for 3 treatments, his renal function began to improve spontaneously. His serum creatinine returned to 3.4 mg/dl, and a subsequent 24-hour urine demonstrated a creatinine clearance of 20 ml/min and an excretion of 1.2 g of protein. Following his discharge from the hospital, his renal function remained unchanged for 3 years, and his blood pressure was easily controlled on monotherapy with a long-acting calcium channel blocker. He recently died from pneumonia.
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PMID:Atherosclerotic Renovascular Disease. 1186 67

Alcoholic hepatitis is a common clinical problem confronting gastroenterologists and hepatologists alike. The fundamental issue regarding treatment of this disease is its recognition on the part of the physician. Chronic alcohol abuse, fever, leukocytosis, jaundice, and encephalopathy are key symptoms and signs that should prompt consideration of this diagnosis. Nutrition and abstinence from alcohol are the cornerstones of therapy. In addition, management of seriously ill, hospitalized patients should include prophylaxis for withdrawal and delirium tremens. Alcoholic hepatitis (AH) induces a profound catabolic state, resulting in net negative nitrogen balance. In part, because of malnutrition, AH carries a considerably high mortality rate. Therefore, nutrition remains a key aspect of therapy. In the absence of encephalopathy and in the presence of a functioning gastrointestinal tract, oral intake or nasogastric feedings should be given. If the gastrointestinal tract cannot be used (ie, because of paralytic ileus), then total parenteral nutrition is absolutely essential for recovery. A select subset of patients, based on multiple clinical trials and several meta-analyses, can be treated with corticosteroids provided that the patient does not have active gastrointestinal bleeding and does not have an active infection. The subset of patients with AH who should receive corticosteroids is based on calculation of a modified Maddrey discriminant function, which incorporates the patient's prothrombin time and total serum bilirubin as variables in this equation. Generally, a 4-week course of prednisone or prednisolone is administered. d-penicillamine, colchicine, anabolic steroids, propylthiouracil, and antioxidants have not been shown to be effective in AH and cannot be recommended. After acute illness, patients should be discharged to an inpatient alcohol rehabilitation unit to ensure continued abstinence.
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PMID:Alcoholic Hepatitis. 1240 78


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