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Biomedical subjects

B Thorp

Publications and source records attributed to B Thorp.

6 recordsLinked to original sources
PubMed2000

Extracellular fatty acid binding protein (Ex-FABP) modulation by inflammatory agents: "physiological" acute phase response in endochondral bone formation.

Ex-FABP, extracellular fatty acid binding protein, is a 21 kDa lipocalin expressed in hypertrophic cartilage, muscle and heart during chick embryo development and in granulocytes. Ex-FABP synthesis was increased in chondrocyte and myoblast cultures by inflammatory agents (LPS; IL6) and repressed by antiinflammatory agents. Expression of Ex-FABP and specific gelatinases is paralleled in hypertrophic cartilage; LPS specifically induced high molecular weight gelatinase ( > 200 kDa). LPS-treated hypertrophic chondrocytes showed increased chemotactic activity for endothelial cells paralleled by increased expression of transferrin. A high amount of Ex-FABP was expressed in adult pathological cartilage both in dyschondroplastic and osteoarthritic chickens. Controls were negative. Ex-FABP could represent a stress protein physiologically expressed in tissues where active remodelling is taking place during development and in tissues characterized by an acute phase response due to pathological conditions. We also suggest that during endochondral bone formation other responses characteristic of a local inflammatory status, such as gelatinase production and angiogenic factor secretion, are "physiologically" activated.

Acute-Phase Reaction↗
PubMed2000

Skeletal development in the meat-type chicken.

1. This study ascertained how bone of modern meat-type chickens develops under typical commercial conditions and compares development with that in genetic precursor stock. 2. A modern fast-growing selected strain and a slower-growing control strain were used. Birds were weighed weekly. A random sample was taken from each population at a range of ages up to 39 d. 3. A tibiotarsus from each bird was X-rayed and its dimensions and estimated resistance to bending were determined. Cortical bone samples were ashed to measure total mineral, calcium and phosphorus content. Cortical samples were also taken for porosity assessment. 4. As expected, the selected strain grew faster and heavier than the control strain. Despite this, both strains demonstrated similar periods of rapid bone formation (days 4 to 18) and mineralisation (days 4 to 11), and achieved similar estimates of resistance to bending. 5. However, cortical bone of the selected strain was less well mineralised and more porous than that of the control strain and showed a significant increase in the molar Ca:P ratios above the expected range of values during the first 2 to 3 weeks of life. 6. Despite production of bones with the correct dimensions for load support, the relatively poor density and mineral content of bone in the selected strain is likely to reduce effective breaking strength of the tibiotarsus. Possible reasons may be either inadequate dietary supply of Ca and P or impaired utilisation of the minerals due to a rapid growth rate or genetic factors.

Animals↗
PubMed1992

Cell proliferation and enzyme activities associated with the development of avian tibial dyschondroplasia: an in situ biochemical study.

Avian tibial dyschondroplasia is a disorder of endochondral ossification which results in the accumulation of noncalcified, avascular cartilage. We have investigated the changes in cell proliferation and enzyme activities within specific cell types in the growth plate of chickens with differing severity of the disease using in situ biochemical techniques that allow the quantification of enzyme activity in unfixed undecalcified sections of tissue. Lactate dehydrogenase activity in the prehypertrophic zone and tartrate-resistant acid phosphatase activity in osteoclasts/chondroclasts were not affected by the severity of the disease. Glucose 6-phosphate dehydrogenase activity in both the proliferating and prehypertrophic zones of the growth plate was reduced in chicks with both moderate and severe lesions. Cell proliferation within the proliferating chondrocytes was slightly reduced in the severely affected birds. Alkaline phosphatase activity in the prehypertrophic chondrocytes was markedly elevated in chicks with moderate and severe lesions. These results rule out an increased rate of chondrocyte proliferation as a possible mechanism for the development of tibial dyschondroplasia. The aetiology of the disease therefore appears to be related to the control of chondrocyte differentiation, mineralization, and vascularization by local and/or systemic growth factors.

Acid Phosphatase↗