Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.9.3.1 (cytochrome oxidase)
 8,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 3-day-old girl had a syndrome of lethargy and lactic acidosis. Pregnancy and delivery had been normal; there was no consanguinity or family history of neuromuscular disease. At age 4 1/2 months, she had generalized weakness, hypotonia, areflexia, and macroglossia. She developed cyanosis and respiratory failure, and marked cardiomegaly was noted. She died at age 8 1/2 months of cardiac arrest. Results from a muscle biopsy specimen obtained at age 4 1/2 months showed ragged-red fibers and increased glycogen and lipid droplets. With the cytochrome c oxidase reaction, only 5% of the fibers stained positively in the biopsy specimen. Cytochrome c oxidase activity was 7.3% of normal in muscle mitochondria and 12.2% of normal in heart mitochondria. Reduced-minus-oxidized cytochrome spectra showed lack of the cytochrome aa3 peak. Immunotitration using antibodies against purified human heart cytochrome c oxidase showed normal amount of cross-reacting material in both heart and muscle. The genetic error could have involved a cytochrome c oxidase isozyme common to heart and muscle.
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PMID:Myopathy and fatal cardiopathy due to cytochrome c oxidase deficiency. 302 95

A human pediatric cardiomyocyte cell culture model of chronic cyanosis was used to assess the effects of low oxygen tension on mitochondrial enzyme activity to address the postoperative increase in lactate and decreased ATP in the myocardium and the high incidence of low-output failure with restoration of normal oxygen tension, after technically successful corrective cardiac surgery. Chronically hypoxic cells (PO2 = 40 mmHg for 7 days) exhibited significantly reduced activities for pyruvate dehydrogenase, cytochrome-c oxidase, succinate cytochrome c reductase, succinate dehydrogenase, and citrate synthase. The activity of NADH-cytochrome c reductase was unaffected. Lactate production and the lactate-to-pyruvate ratio were significantly greater in hypoxic cardiomyocytes. Western and Northern analysis demonstrated a decrease in the levels of various mRNA and corresponding polypeptides in hypoxic cells. Thus hypoxia influences mitochondrial metabolism through acute and chronic adaptive mechanisms, reflecting allosteric (posttranscriptional) and transcriptional modulation. Transcriptional downregulation of key mitochondrial enzyme systems can explain the insufficient myocardial aerobic metabolism and low-output failure in children with cyanotic heart disease after cardiac surgery.
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PMID:Myocardial aerobic metabolism is impaired in a cell culture model of cyanotic heart disease. 981 75

A-79-year-old woman ingested a cup of unknown violet agricultural solution intentionally. She was vomiting and smelt of sulfur. Arterial blood gas showed metabolic acidosis and marked cyanosis regardless of relatively high PaO2, caused by sulfhemoglobinemia. A nasogastric tube could not be inserted because of marked stenosis caused by endoscopically proven severe corrosive chemical injury (burn) of esophagus. Considering the smell and the clinical presentation, we concluded that the causative agent was calcium polysulfide or lime-sulphur solution, a common agricultural product used as a fungicide. Despite supportive therapy including infusion of NaNO2, the patient expired 4.5 hours after ingestion. Calcium polysulfide ingestions cause direct injury to the upper gastrointestinal tract, and react with gastric HCl producing poisonous H2S gas, which interferes cytochrome oxidase activity, developing tissue hypoxia, shock, and metabolic acidosis. Sulfhemoglobin is also produced causing severe cyanosis.
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PMID:[Fatal calcium polysulfide overdose presenting corrosive chemical injury of esophagus and sulf-hemoglobinemia]. 1210 22