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)

The influence of irradiation was studied histochemically in healing mandibular periosteum and bone. After a cut line had been made on both sides of the mandible the rats were exposed to roentgen ray irradiation. The single doses were 15, 20, 30, 35 or 40 Gy. The animals were killed 1, 2, 4, 8, 10, 12, 16 and 24 hours after irradiation, for histochemical analysis. All enzymes, acid phosphatase, cytochrome oxidase, lactate, isocitrate, glucose-6-phosphatase and succinate dehydrogenase, showed a greater increase in enzyme staining in the irradiated cut lines than in the non-irradiated control lines. The intensity of the staining increased with time and dose over 24 hours. The observation time included an inflammatory phase with vascular, enzymatic and cellular responses to periosteal and bone injury. The increase in staining was dependent on the time after surgical trauma and radiation dose. The increase in enzyme staining probably represents the initial cell damage after irradiation.
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PMID:Effect of irradiation on early enzymatic changes in healing mandibular periosteum and bone. A histochemical study on rats. 302 Aug 89

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

Changes in optical attenuation, relevant to cytochrome oxidase, of the rat bone periosteal tissue in explanted culture and human neuronal cells in three-dimensional agarose constructs have been monitored by the use of optical coherence tomography (OCT), with potential applications in tissue engineering and diagnosis. A superluminescent diode (SLD) with a peak emission wavelength (lambda = 820 nm) that is the near-infrared absorption band of the oxidized form of CytOx was employed. The attenuation coefficient was obtained from the depth-resolved reflectance profiles of liquid phantoms (naphthol green B with intralipid), explant culture (periosteum of calvaria from rats) and cells in 3D agarose constructs. The absorption coefficient of naphthol green B can be accurately quantified by the linear relationship between attenuation coefficients and the concentration. The difference in the attenuation coefficient of astrocytoma cells in agarose before and after reduction of CytOx is 0.26 +/- 0.10 mm(-1) ( n = 9), whereas no attenuation is observed with the agarose control. Reduction of the enzyme in periosteal tissue leads to a change in attenuation coefficient of 0.43 +/- 0.24 mm(-1) ( n = 7). For comparison, using a biochemical assay, the absorption coefficient of the oxidized-reduced form of CytOx is measured at approximately 8.3 +/- 1.5x10(-3) mm-1 ( n = 4) and 8.7 +/-2.5x10(-3) mm-1 ( n = 4) at 820 nm for astrocytoma cells and rat periosteum, respectively. The lower value of CytOx concentration using biochemical versus OCT measurements may result from shifts in the scattering profile and the amplifying influences of multiple heme-based oxidases, indicating that conventional OCT is not specific enough to monitor redox changes in cytochrome oxidase. However, qualitative shifts in oxidation state are apparent using the technique. Our results suggest the potential application of OCT in providing high-resolution tomographic imaging of tissues in organ culture and cells grown in three-dimensional constructs in vitro.
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PMID:Investigation of changes in optical attenuation of bone and neuronal cells in organ culture or three-dimensional constructs in vitro with optical coherence tomography: relevance to cytochrome oxidase monitoring. 1285 93