Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042963 (vomiting)
 31,883 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Eleven substituted 8-amino-3-benzyl-1,2,4-triazolo[4,3-a] pyrazines were synthesized and tested for anticonvulsant activity against maximal electroshock-induced seizures (MES) in rats. The compounds were prepared in four stages from the phenylacetonitriles. I. The intermediate (2,2,2-triethoxyethyl)benzenes III were condensed with 2-chloro-3-hydrazinopyrazine (IV) to provide the 3-benzyl-8-chloro-1,2,4-triazolo[4,3-a]pyrazines V. The latter were converted to the 8-amine targets VI with methylamine or ammonia. Several compounds exhibited potent activity against MES; the 3-(2-fluorobenzyl)-8-(methylamino) and 3-(2,6-difluorobenzyl)-8-(methylamino)congeners (4 and 12) exhibited the best anticonvulsant activity with oral ED50S of 3 mg/kg. The 1,2,4-triazolo[4,3-a]pyrazine ring system serves as a bioisostere of the purine ring for anticonvulsant activity; however, these agents exhibit less propensity to cause emesis.
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PMID:8-Amino-3-benzyl-1,2,4-triazolo[4,3-a]pyrazines. Synthesis and anticonvulsant activity. 765 56

Late onset of symptoms in a 12 1/2-year-old male with ornithine transcarbamylase (OTC) deficiency were associated with unusual histological features in the liver. The patient presented with an acute onset of hyperammonemia and altered mental status after a 2-day prodrome of vomiting and lethargy. Physical examination showed a combative and disoriented male with icteric sclerae but with no fever or hepatomegaly. The plasma ammonia level was 282 microM. Enzyme assays of liver tissue obtained by percutaneous needle biopsy showed OTC activity of approximately 3% of normal; carbamyl phosphate synthetase was normal. Histopathological findings included severe microvesicular centrilobular steatosis. Hepatic architecture and reticulin framework were well preserved. Many hepatocyte nuclei were filled with glycogen. Electron microscopy showed mitochondria that were rounded and expanded with cristae at the edge of the mitochondrial membrane. In contrast to other reports, only slight variations in size and shape were seen. Megamitochondria and intramatrical paracrystalline inclusions were not identified. The cytoplasm contained scattered fat globules, peroxisomes, and dilated smooth endoplasmic reticulum. The prominent mitochondrial abnormalities commonly found in OTC deficiency were notably absent.
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PMID:Histopathological findings in a male with late-onset ornithine transcarbamylase deficiency. 800 87

Portal hypertension caused by primary hypoplasia of the portal vein was diagnosed in 42 dogs. The portal hypertension was manifested by the presence of multiple portosystemic collateral vessels. The main clinical signs were retarded growth or weight loss, apathy, intermittent diarrhoea and vomiting, anorexia, abdominal distension and polydipsia. Major findings at physical examination were ascites in 23 dogs and neurological signs in 16 dogs. The dogs had increased activities of liver enzymes in plasma and increased fasting levels of total bile acids and ammonia; in many of the dogs the packed red cell volume, total serum protein and albumin were low. Gross inspection of the portal vein revealed a patent but underdeveloped extrahepatic vein in 13 of the dogs. Microscopic examination of the liver revealed hypoplasia of the intrahepatic portal veins in all the dogs, and this was associated with minor arteriolar proliferation and absence of fibrosis in 12 of them, with moderate to marked arteriolar proliferation often combined with ductular proliferation in 13, and with marked portal fibrosis (formerly described as hepatoportal fibrosis) with a varying number of arteriolar and bile ductular structures in 17 of the dogs. The disease affected mainly young dogs, and was most likely to have been of congenital origin.
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PMID:Portal hypertension associated with primary hypoplasia of the hepatic portal vein in dogs. 856 Jul

Since the discovery of the biologically active platinum complexes 30 years ago, 2 agents have become widely established in clinical oncology practice. Both cisplatin and carboplatin are platinum(II) complexes with 2 ammonia groups in the cis- position. However, they differ in their solubility, chemical reactivity, dichloride or alicyclic oxygenated leaving groups, pharmacokinetics and toxicology. Cisplatin causes severe renal tubular damage and reduces glomerular filtration, and requires concurrent saline hydration and mannitol diuresis to eliminate potentially lethal and unacceptable damage to the kidneys. Carboplatin, at conventional doses, causes no decrease in glomerular filtration and only minor transient elevations in urinary enzymes. Cisplatin is the most emetic cancer drug in common use, while nausea and vomiting associated with carboplatin are moderately severe. Serotonin release from enterochromaffin gut mucosal cells and stimulation of serotonin 5-HT3-receptors mediates acute emesis. Selective inhibitors of the 5-HT3-receptor protect against cisplatin- and carboplatin-induced nausea and vomiting. Peripheral neurotoxicity is the most dose-limiting problem associated with cisplatin. Loss of vibration sense, paraesthesia and sensory ataxia comes on after several treatment cycles. Carboplatin, however, is relatively free from peripheral neurotoxicity. Audiometry shows cisplatin-induced ototoxicity in 75 to 100% of patients, which may be associated with tinnitus and hearing loss. Ototoxicity is rare with conventional dose carboplatin therapy. Monitoring hearing with audiograms may identify early signs before significant impairment occurs. Cisplatin causes mild haematological toxicity to all 3 blood lineages. Haematological toxicity is dose-limiting for carboplatin, with thrombocytopenia being a greater problem than leucopenia. Although carboplatin is not toxic to the kidney, renal function markedly affects the severity of carboplatin-induced thrombocytopenia. The major clearance mechanism of cisplatin is irreversible binding in plasma and tissues, while carboplatin is cleared by glomerular filtration. Metabolism of cisplatin to aqua, amino acid and protein species is extensive, whereas carboplatin exists mainly as the free unchanged form. Strong relationships between carboplatin renal clearance, glomerular filtration rate, area under the plasma concentration-time curve (AUC) of filterable platinum and severity of thrombocytopenia have prompted dose adjustment according to renal function. New analogues such as JM216 offer the potential advantages of oral administration and few nonhaematological toxicities. Analogues based on the diaminocyclohexane ligand have encountered problematic neurotoxicity.
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PMID:Comparative adverse effect profiles of platinum drugs. 857 96

Feeding problems, anorexia and vomiting are common in infants and children with chronic renal failure (CRF), and play a major role in the growth failure often found in this condition. However, the gastroenterological and nutritional aspects of CRF in children have received little attention, hence therapeutic interventions are usually empirical and often ineffective. Gastritis, duodenitis and peptic ulcer are often found in adults with CRF on regular haemodialysis and following renal transplantation. Despite persistent hypergastrinaemia, gastric acid secretion is decreased rather than increased in most of these patients, and active peptic disease appears to be promoted by the removal of the acid output inhibition (neutralisation of gastric acid by ammonia) that follows active treatment. Helicobacter pylori, on the other hand, does not seem to play a significant role in the pathogenesis of peptic disease in CRF. Gastro-oesophageal reflux has been found in about 70% of infants and children with CRF suffering from vomiting and feeding problems, and thus appears to be a major problem in these patients. In a number of symptomatic patients with CRF, gastric dysrhythmias and delayed gastric emptying have also been found; hence there appears to be a complex disorder of gastrointestinal motility in CRF. Serum levels of several polypeptide hormones involved in the modulation of gastrointestinal motility [e.g. gastrin, cholecystokinin (CCK), neurotensin] and the regulation of hunger and satiety (e.g. glucagon, CCK) are significantly raised as a consequence of renal insufficiency, and can be reverted to normal by renal transplantation. Furthermore, several other humoral abnormalities (e.g. hypercalcaemia, hypokalaemia, acidosis, etc.) are not uncommon in CRF. By directly affecting the smooth muscle of the gut or stimulating particular areas within the central nervous system, all these humoral alterations may well play a major role in the gastrointestinal dysmotility, anorexia, nausea and vomiting in patients with CRF. Specific pharmacological and nutritional interventions should thus be considered for the treatment of vomiting and feeding problems in CRF.
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PMID:Gastrointestinal function in chronic renal failure. 874 22

Citrullinemia, a rare inborn error of metabolism, is characterized by a deficiency of argininosuccinic acid synthetase that results in large increases in plasma ammonia, citrulline, and glutamine, with normal acid-base balance. The neurologic symptoms vary from poor feeding, vomiting, and irritability to hypotonia, apnea, and death. The most common pathologic findings at autopsy are cerebral edema and focal neuronal necrosis. We describe a case of fulminant citrullinemia in an infant in whom the major pathologic findings included diffuse cerebral edema and a lack of overt metabolic derangement characteristic of neonates with a urea cycle defect. Our case differs from the classic presentation of citrullinemia in that subarachnoid hemorrhage was identified early in the clinical course. We report the first observation of subarachnoid hemorrhage in an infant with a urea cycle defect.
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PMID:Perinatal pathology casebook. 886 47

The case is reported of an infant with hyperammonaemia secondary to severe distal renal tubular acidosis. A clinical association between increased concentrations of ammonia in serum and renal tubular acidosis has not previously been described. In response to acidosis the infant's kidneys presumably increased ammonia synthesis but did not excrete ammonia, resulting in hyperammonaemia. The patient showed poor feeding, frequent vomiting, and failure to thrive, but did not have an inborn error of metabolism. This case report should alert doctors to consider renal tubular acidosis in the differential diagnosis of severely ill infants with metabolic acidosis and hyperammonaemia.
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PMID:Hyperammonaemia with distal renal tubular acidosis. 948 70

Ornithine transcarbamylase deficiency is an X linked disorder and the most common inherited cause of hyperammonaemia. Fluctuating concentrations of ammonia, glutamine, and other excitotoxic amino acids result in a chronic or episodically recurring encephalopathy. A heterozygous female patient first presented with protein intolerance, attacks of vomiting, and signs of mental retardation in early childhood. At the age of 16 complex partial seizures occurred which were treated with sodium valproate. Seven days after initiation of valproate therapy, she developed severe hyperammonaemic encephalopathy with deep somnolence. The maximum concentration of ammonia was 480 micromol/l. After withdrawal of valproate, three cycles of plasma dialysis, and initiation of a specific therapy for the inborn metabolic disease, ammonia concentrations fell to normal values. The patient remitted, returning to her premorbid state. Valproate can cause high concentrations of ammonia in serum in patients with normal urea cycle enzymes and may worsen a pre-existing hyperammonaemia caused by an enzymatic defect of the urea cycle. Sufficient diagnostic tests for the detection of metabolic disorders must be performed before prescribing valproate for patients with a history of encephalopathy.
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PMID:Hyperammonaemic encephalopathy after initiation of valproate therapy in unrecognised ornithine transcarbamylase deficiency. 959 92

Inherited hyperammonemia disorders are caused by specific enzymatic defects in the urea cycle or in metabolic pathways related to it. These disorders can be divided into the following groups: deficiencies of urea cycle enzymes, transport defects of dibasic amino acids, organic acidemias, defects in beta-oxidation of fatty acids, transient hyperammonemia of the newborn-probably a not genetically determined disorder. Manifestation of the mentioned disorders includes elevated serum ammonia level resulting in altered level of consciousness and/or persisted vomiting. Occurrence of irreversible neurologic sequelae depends mostly on the extent of hyperammonemic period. Differential diagnosis includes blood gas, anion gap, plasma amino acids analysis and urine organic acids analysis. In some cases specific tissue enzymes activity measurement is necessary. Dialysis, sodium benzoate, sodium phenylacetate and arginine are used in the treatment of acute hyperammonemia. In addition oral or rectal neomycin and/or lactulose can be used, which reduces intestinal ammonia production.
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PMID:[Inherited hyperammonemia]. 985 11

Reye syndrome is characterized by acute encephalopathy and fatty degeneration of the liver almost exclusively in children. The onset is heralded by profuse vomiting and varying neurologic impairment from irritability to coma, decerebration and death. The encephalopathy must be associated with a greater increase in the levels of ammonia, or alanine amino-transferase and aspartate amino-transferase in serum; and with a fatty metamorphosis of the liver diagnosed by biopsy or at autopsy. The only characteristic universally accepted as diagnostic are the specific mithocondrial changes in the liver-biopsy specimen. Larger studies confirmed the association of aspirin with RS. The CDC of Atlanta cautioned physician and parents and a dramatic decline in case began at that time. Classic Reye syndrome is now so rare in the USA that when an apparent case is encountered in a child who has not taken aspirin, other diagnoses should be considered. After a brief survey of RS relative lack of specificity of case definition and of the polyhedric etiopathogenetic moments, the A. on the personal experience, point: a) the biological unicity of the man and the necessary coexistence of "constitutional" factors (metabolic and/or endocrine, and/or immunitary factors, the later almost never investigated), toxic, and infectious factors for the syndrome's deflagration; b) some aspects of the continued existence of therapeutic and diagnostic problems: the aspirin and/or salicilate use and the pharmacogenetic; the continued existence of other, generally similar conditions, such the drug and other known and unknown toxic mithocondrial factors that provoke this unusual response to common infections; and the inborn errors of metabolism; c) some practical aspects of diagnostic and therapeutic approach.
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PMID:[Reye's syndrome: the death of a syndrome? (Or death by a syndrome?)]. 1119 89


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