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

The present study was conducted on bone tissue responses to irradiation towards a treatment model of mandibular irradiation injury by comparing the results of experimental observations of irradiation effects on rabbit hind legs and rat mandibular bones (paper I, II and III) with clinical observations of irradiation effects on the human mandible (paper IV, V and VI). The main results of the study were as follows: Bone marrow haemorrhage, eosinophilia and incipient edema were encountered in the rabbit leg one day after a single irradiation dose. Edema and fibrosis were the salient features after five weeks, while both regenerative and fibrotic changes predominated eleven weeks after irradiation. The changes were the more extensive the greater the irradiation dose was. Empty lacunae as a sign of cell damage in cortical bone already appeared on the first day after irradiation; this effect reached its maximum when the dose was 20 Gy or more. Bone marrow and subcutaneous tissue pO2 and pCO2 were measured by means of implanted Silastic tonometers in irradiated and nonirradiated rabbit hind legs. Single dose irradiation was followed by a rapid, dose dependent decrease of marrow pO2. The corresponding effect on pCO2 was weaker and appeared later. The response to hyperoxia in the bone marrow became weaker when the irradiation dose increased. Less significant was the response of CO2 tension to hyperoxia. O2 and CO2 tensions were recovered after single dose irradiation both in subcutaneous tissue and in bone marrow, but the reduction was less in bone marrow. During the twelve weeks observation period clearly better recovery in tissue gas tensions was observed in subcutaneous tissue than in bone marrow. Nonirradiated periosteal grafts on irradiated bone cavities in the rabbit tibia induced more rapid and intense mature bone formation than irradiated periosteal grafts. The irradiated periosteum, even after a single dose of 20 Gy, had some osteogenetic capacity. The alkaline phosphatase content was lowered eight weeks after surgery in irradiated legs but clearly exceeded control values twelve weeks after surgery indicating new bone formation. Lysosomal enzyme DAP II contents were increased in all irradiated specimens as a sign of disturbed bone formation. The tissue concentrations of acid phosphatase, cytochrome oxidase, lactate dehydrogenase, isocitrate dehydrogenase, glucose-6-phosphate dehydrogenase and succinate dehydrogenase in the immediate postirradiation period showed a greater increase in activity in the cut lines of the irradiated rat mandibles than in those of the nonirradiated mandibles.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Bone tissue response to irradiation and treatment model of mandibular irradiation injury. An experimental and clinical study. 309 Aug 54

The enzyme cytochemistry and proportion of mononuclear cells exclusively present within degenerating muscle fibres of the soleus of rats 24 h after a single intraperitoneal injection of 5-hydroxytryptamine (5-HT) (10 mg/kg) were studied. The following enzymes displayed strong cytochemical activities within these cells: non-specific esterase (against naphthol AS-D acetate and alpha-naphthylacetate), aminopeptidase (against leucine-4-methoxy-2-naphthylamide) and dipeptidyl peptidase II. A peroxidatic activity was also present, but was found to arise from cytochrome oxidase in phagocytosed muscle mitochondria. The aminopeptidase activity in the monocytic cells increased by roughly 50% between 6 and 24 h after 5-HT administration. Dipeptidyl peptidase II was found, by the use of appropriate inhibitors, to be present in both mononuclear cells and muscle fibres and may be implicated in degrading the basal lamina of muscle fibres, thereby permitting access to the mononuclear cells. The morphological, enzyme histochemical and electron microscopical evidence suggest that the cells which invade muscle fibres in the early stages of a myopathy induced by 5-HT in rats are actively phagocytosing, mature macrophages.
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PMID:Some histochemical observations on invasive cells in a myopathy induced in rats with 5-hydroxytryptamine. 652 33