1/44. hyperammonemia after high-dose chemotherapy and stem cell transplantation.We report a patient with multiple myeloma who suffered from hyperammonemia after a second stem cell autograft. This syndrome is not well known but is associated with a high mortality rate. Considering the possibility of this diagnosis in patients developing confusion and neurological degradation with respiratory alkalosis after intensive chemotherapy, could allow earlier treatment and perhaps improved survival. Possible mechanisms and potential therapies are discussed. With rapid recognition and treatment of the syndrome, the patient fully recovered. One and a half years later, she is still alive and well, on interferon for persisting myeloma.- - - - - - - - - - ranking = 1keywords = hyperammonemia (Clic here for more details about this article) |
2/44. Intravenous ribavirin and hyperammonemia in an immunocompromised patient infected with adenovirus.ribavirin is a synthetic guanosine analog with activity against dna and rna viruses. It was studied in human trials, and no marked adverse effect was reported beyond the potential for teratogenicity and reversible mild anemia. An 8-year-old girl received a multivisceral transplant and developed adenoviral pneumonia. She was treated with intravenous ribavirin and became hyperammonemic. Discontinuation of ribavirin led to a decrease in ammonia levels. This pattern was repeated when the drug was restarted and discontinued. We hypothesize that in a toxic environment the interaction of ribavirin with hepatocellular mitochondrial enzymes may lead to hyperammonemia.- - - - - - - - - - ranking = 5keywords = hyperammonemia (Clic here for more details about this article) |
3/44. Continuous arteriovenous hemodiafiltration in the acute treatment of hyperammonaemia due to ornithine transcarbamylase deficiency.BACKGROUND: Acute hyperammonemia caused by urea cycle disorder is a medical emergency for which immediate managements should be taken to minimize permanent brain damage. Among different enzyme defects, ornithine transcarbamylase deficiency (OTC) is one of the most common enzyme defect in urea cycle disorders. We utilized continuous renal replacement therapy techniques in the acute treatment of hyperammonemia due to ornithine transcarbamylase deficiency. patients AND methods: Three male neonates with elevated serum ammonia levels were shown, based on urine organic acid analysis and serum amino acid studies, to have OTC deficiency. Administration of sodium benzoate and sodium phenylacetate for activating alternative nitrogen waste pathway were used associated with protein restriction. Other modalities, including blood exchange transfusion, peritoneal dialysis, continuous renal replacement therapy were utilized in an attempt to lower serum ammonia concentration. RESULTS: We report the successful use of continuous arteriovenous hemofiltration (CAVH), continuous arteriovenous hemodialysis (CAVHD), continuous arteriovenous hemodiafiltration (CAVHDF) in the acute management of hyperammonemia due to OTC deficiency. We also compared the ammonia clearance between peritoneal dialysis, exchange transfusion, CAVH, CAVHD and CAVHDF. It demonstrated the evidence that CAVHDF provides the best ammonia clearance. CONCLUSION: Continuous renal replacement therapy including CAVH, CAVHD, and CAVHDF may be the alternative techniques for acute management of hyperammonemia in inborn error of metabolism when dialysis machine is not available. Our data suggests CAVHDF provides the best ammonia clearance.- - - - - - - - - - ranking = 4keywords = hyperammonemia (Clic here for more details about this article) |
4/44. Reversible parkinsonism and hyperammonemia associated with portal vein thrombosis.Portal-systemic encephalopathy may be seen with hyperammonemia that complicates chronic liver disease. We report an unusual case of reversible parkinsonism associated with hyperammonemia and portal vein thrombosis. An active 90-year-old male developed motor slowing and resting hand tremor over 6 months. Examination showed asterixis, bradykinesia, cogwheel rigidity, rest tremor, and a parkinsonian gait. serum venous ammonia was elevated at 145 microM. The next day, the patient became comatose and serum ammonia was 178 microM. With lactulose therapy, serum ammonia level normalized and examination showed only minimal parkinsonism after 1 week. An abdominal CT scan identified portal vein thrombosis with porto-systemic shunting that reversed after 7 months of treatment. Examination 2 years later showed no signs of parkinsonism. Parkinsonism can dominate the clinical picture of patients with hyperammonemia before the onset of encephalopathy.- - - - - - - - - - ranking = 7keywords = hyperammonemia (Clic here for more details about this article) |
5/44. Protein-sensitive and fasting hypoglycemia in children with the hyperinsulinism/hyperammonemia syndrome.OBJECTIVE: Because the hyperinsulinism/hyperammonemia (HI/HA) syndrome is associated with gain of function mutations in the leucine-stimulated insulin secretion pathway, we examined whether protein feeding or fasting was responsible for hypoglycemia in affected patients. STUDY DESIGN: patients with HI/HA (8 children and 6 adults) were studied. All had dominantly expressed mutations of glutamate dehydrogenase and plasma concentrations of ammonium that were 2 to 5 times normal. The responses to a 24-hour fasting test were determined in 7 patients. Responses to a 1.5 gm/kg oral protein tolerance test in 12 patients were compared with responses of 5 control subjects. RESULTS: The median age at onset of hypoglycemia in the 14 patients was 9 months; diagnosis was delayed beyond age 2 years in 6 patients, and 4 were not given a diagnosis until adulthood. fasting tests revealed unequivocal evidence of hyperinsulinism in only 1 of 7 patients. Three did not develop hypoglycemia until 12 to 24 hours of fasting; however, all 7 demonstrated inappropriate glycemic responses to glucagon that were characteristic of hyperinsulinism. In response to oral protein, all 12 patients with HI/HA showed a fall in blood glucose compared with none of 5 control subjects. Insulin responses to protein loading were similar in the patients with HI/HA and control subjects. CONCLUSION: The postprandial blood glucose response to a protein meal is more sensitive than prolonged fasting for detecting hypoglycemia in the HI/HA syndrome.- - - - - - - - - - ranking = 5keywords = hyperammonemia (Clic here for more details about this article) |
6/44. hyperammonemia in urea cycle disorders: role of the nephrologist.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.- - - - - - - - - - ranking = 4keywords = hyperammonemia (Clic here for more details about this article) |
7/44. A pediatric patient with classical citrullinemia who underwent living-related partial liver transplantation.patients with inborn errors of metabolism undergo liver transplantation, but the effect of transplanting the liver of healthy carriers of these conditions has not been fully clarified. A 6-year-old girl with classical citrullinemia, who repeatedly suffered from hyperammonemia, underwent living-related liver transplantation by using a segment of the liver of her mother, who was a heterozygote carrier for classical citrullinemia. hyperammonemia alleviated in the patient after the transplantation, thereby dramatically improving her quality of life. Although the levels of plasma and urinary citrulline remained high postoperatively, there was no marked difference in the level of plasma citrulline up to 1 month after surgery when compared with that of previously reported orthotopic liver transplantation cases with classical citrullinemia.- - - - - - - - - - ranking = 1keywords = hyperammonemia (Clic here for more details about this article) |
8/44. arginine deficiency-induced hyperammonemia in a home total parenteral nutrition-dependent patient: a case report.BACKGROUND: patients with short bowel syndrome and renal dysfunction with TPN dependence are at high risk for developing hyperammonemia if the TPN does not contain sufficient quantities of arginine. Providing proper nutrition support is essential in the management of these patients. methods: We report on a patient with short bowel syndrome, TPN dependence, and normal renal function who developed hyperammonemic encephalopathy due to inadvertent lack of arginine in his TPN. RESULTS: The patient was successfully treated with hemodialysis and an IV arginine infusion to resolve the hyperammonemia. His home TPN was also adjusted such that arginine was added to his subsequent solutions. CONCLUSIONS: Our patient underscores the importance of adequate and sustained arginine supplementation to avoid hyperammonemia in TPN dependent patients with short bowel syndrome.- - - - - - - - - - ranking = 7keywords = hyperammonemia (Clic here for more details about this article) |
9/44. hyperammonemia and coma without hepatic dysfunction induced by valproate therapy.The authors report a case of a 41-year-old mentally disabled man with bipolar disorder who presented to the emergency department with altered mental status. He was found to have a significantly elevated ammonia level (377 microM/L) with no signs of hepatic insufficiency. His coma and hyperammonemia were attributed to his chronic valproate therapy. This patient had the highest serum ammonia level ever reported with a therapeutic valproate level in the absence of any other anticonvulsant therapy, metabolic abnormality, or hepatic dysfunction. The authors discuss this case and review the current literature on hyperammonemia in valproic acid therapy and the use of L-carnitine in these patients.- - - - - - - - - - ranking = 2keywords = hyperammonemia (Clic here for more details about this article) |
10/44. Establishment of CD7 human myeloma sister cell lines, KMS-21-PE and KMS-21-BM, carrying t(11;14) and t(8;14).Two new human myeloma cell lines were established from pleural effusion and bone marrow malignant cells derived from a single patient, who manifested hyperammonemia associated with multiple myeloma, and these were characterized. Both lines possess t(11;14)(q13;q32) and t(8;14)(q24;q32) reciprocal translocations and overexpress cyclin d1, but not c-myc. Human myeloma lines including these new lines produced and secreted excess ammonia into culture medium more than non-myelomatous hematological cell lines. In addition, these two lines were revealed to have high surface CD7 expression correlated with relatively high mRNA expression by MP-RT-PCR. Among 8 human myeloma lines, half of them revealed significant surface expression of CD7 and a positive correlation between expression levels of protein and message. CD7 message was also detected in surface negative lines. Consequently, there may be posttranslational regulation of the CD7 molecule, whose cellular biological role in expressing cells has not been elucidated.- - - - - - - - - - ranking = 1keywords = hyperammonemia (Clic here for more details about this article) |
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