Studies on the role of manganese in bone formation. I. Effect upon the mucopolysaccharide content of chick bone.
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Animals↗
Biomedical subjects
R M Leach
Publications and source records attributed to R M Leach.
Isolation and characterization of microvascular endothelial cells from chicken fat pads.
Microvascular endothelial cells from abdominal fat pads of 6-wk-old broiler chickens were isolated to provide an in vitro system to study their physiological functions. The isolation procedure produced clumps of 10-30 cells, which attached to culture vessels in 4 h and attained confluency in 2 wk. At confluency, cells had a cobblestone appearance but were not contact inhibited and detached from the bottom of the culture vessel 2 wk after reaching confluency. The cells internalized acetylated low density lipoproteins, a characteristic of endothelial cells. This property was used to obtain pure endothelial cell cultures using the cell sorter. When cultured over Matrigel, a reconstituted matrix, the cells aligned themselves into chordlike structures and formed branching microvessels. Cells plated on type I collagen-coated culture flasks occasionally formed chordlike structures and proliferated at a faster rate than cells plated on Matrigel. Cells cultured on laminin-coated plates were slender and had long cytoplasmic extensions; however, cells cultured on uncoated plastic had fibroblastic morphology. These properties are similar to those described for microvessel endothelial cells isolated from tissues of other species.
3T3 Cells↗
Tritiated thymidine uptake in chondrocytes of chickens afflicted with tibial dyschondroplasia.
3H-Thymidine was localized in sections of growth-plate cartilage and associated tibial dyschondroplastic lesion by autoradiography. One hour after 3H-thymidine was injected, radioactivity was found in the proliferating zone; after 48 hr it was also in the hypertrophic zone, and by 96 hr it was present in cells that were 4 to 5 mm into the lesion. This indicates that the lesion develops from the growth plate itself. The life span of the cells in the growth plate appears to be about 48 hr.
Animals↗
Activities and distribution of alkaline phosphatase and carbonic anhydrase in the tibial dyschondroplastic lesion and associated growth plate of chicks.
The tibial dyschondroplastic lesion and associated growth plate were examined for the presence of alkaline phosphatase, an enzyme important in cartilage mineralization, and carbonic anhydrase, an enzyme that regulates acid-base balance of many tissues including cartilage. By histochemistry, both enzymes were found to be present in the prehypertrophic and hypertrophic zones of the growth plate as occurs normally. Enzyme activity was normal or close to normal in the growth plate. Activity was diminished to half of the normal values in the proximal lesion and to zero in the distal lesion. The enzymes are believed to be diminished by necrotic and autolytic processes and are not involved in initiating the formation of the lesion.
Alkaline Phosphatase↗
Role of manganese in the synthesis of mucopolysaccharides.
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Animals↗
Role of manganese in mucopolysaccharide metabolism.
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Animals↗
Physiologic and electrocardiographic changes occurring in broilers reared at simulated high altitude.
An experiment was conducted to determine whether differences in the electrocardiograms (EKGs) of broilers reared at simulated high altitude from the day of hatch can be used to predict which birds are developing ascites. In three replicate experiments, conducted with 100 broilers per replicate, birds were reared at a simulated altitude of 3000 meters or at ambient atmospheric pressure. Lead I, II, and III EKGs were obtained from all birds on days 0, 14, 28, and 42. No consistent significant differences were seen on day 0 in the amplitude of the R or S wave or total amplitude of the QRS complex when broilers that developed ascites while being reared at simulated high altitude were compared with unaffected birds reared at simulated high altitude and with birds reared at ambient atmospheric pressure. On days 14 and 28, the average amplitude of the S wave and the total amplitude of the QRS complex were significantly higher in the ascites group than in the two other groups. Packed cell volumes were significantly higher in birds reared at simulated high altitude at all sampling days (days 14, 28, and 42) than in those reared at ambient atmospheric pressure, and they were significantly higher in the ascites group on day 28 than in the two other groups. Birds in the ascites group weighed significantly less than the two other groups by day 14, and this trend persisted.
Altitude↗
Non-reducible collagen cross-linking in cartilage from broiler chickens with tibial dyschondroplasia.
Recent work has shown that hydroxylysylpyridinoline (HP), a non-reducible cross-link that stabilizes the collagen fibril network, is significantly greater (over 10-fold) in dyschondroplastic cartilage than in normal growth-plate cartilage in the tibiotarsi of chickens with homocysteine-induced tibial dyschondroplasia (TD). In the present study, broiler chicks with a genetic disposition to TD, as well as normal broiler chicks on a copper-deficient diet alone or supplemented with copper and thiram, were raised for 3 to 4 weeks (Expts. 1 and 2). Their dyschondroplastic cartilage from the proximal tibiotarsus was collected and analyzed for HP as well as lysylpyridinoline (LP) cross-links. Normal growth plate cartilage was obtained from chicks on the copper-deficient diet supplemented with copper. In a third experiment, another set of broiler chicks was raised on a corn/soybean meal-based diet with or without homocysteine, and their articular and sternal cartilage were isolated for cross-link analysis. In the first two experiments, dyschondroplastic cartilage from all birds with induced TD had higher HP and LP concentrations than growth-plate cartilage from birds without TD, although the ratios of HP to LP varied. In the third experiment, the sternal and articular cartilage from birds with homocysteine-induced TD appeared normal, having similar HP concentrations in the same types of cartilage in birds without TD.
Amino Acids↗
Acute oxygen therapy.
Tissues require oxygen for survival. Its delivery depends on adequate ventilation, gas exchange and distribution in the circulation. Many causes of hypoxaemia can be corrected by adding oxygen to the inspired air but response is variable and must be measured.
Humans↗
Domiciliary oxygen therapy.
Domiciliary oxygen is prescribed widely and often with benefit. However, patients with chronic lung disease, in whom its efficacy is proven, continue to be denied adequate assessment and treatment. It is time to ensure that this expensive treatment is given to those who will benefit in a manner that maximizes the improvement in the quality of life.
Home Care Services↗
Gene expression during cartilage differentiation in turkey tibial dyschondroplasia, evaluated by in situ hybridization.
Gene expression and alkaline phosphatase (AP) activity, associated with chondrocyte differentiation, were evaluated in the epiphyses of normal and tibial dyschondroplasia (TD)-afflicted turkeys. In the normal turkey growth plate (GP), osteopontin (OPN) and type X collagen genes were expressed by the hypertrophic cells in both GP and secondary ossification center, parallel to manifestation of AP activity. Collagen type II gene expression was restricted to the nonhypertrophic chondrocytes at the upper part of the GP. OPN or collagen type X genes were not expressed within the TD lesion. However, these genes were expressed in areas proximal and distal to the lesion, suggesting that after reaching partial differentiation, chondrocytes within the developing TD lesion de-differentiate into cells that resemble chondrocytes in the prehypertrophic zone. This suggestion is supported by the observation that the cells in the lesion expressed the collagen type II gene. In some cases, the TD lesion was invaded by fibroblastlike cells that did not exhibit any AP activity or expressed the OPN gene. No lesions were observed in the secondary ossification centers.
Animals↗