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J A Gallagher

Publications and source records attributed to J A Gallagher.

76 records · Page 5Linked to original sources
PubMed1980

Histological observations on the failure of rachitic rat bones to respond to 1,25/OH)2D3.

Rachitic rats, maintained on diets with low or normal P contents, were given daily intraperitoneal doses of 1,25(OH)2D3 or 25OHD3 at levels of 100 or 200 ng. Plasma chemistry was measured and the ash content and histological appearance of the bones investigated. Using labeled material it was shown that the dosing levels of 1,25(OH)2D3 employed ensured a higher than normal plasma concentration of that metabolite over the period between doses. 1,25(OH)2D3 was not effective as 25OHD3 in raising bone ash or reducing the amount of osteoid. The difference between the effects of the metabolites was evident at both dietary P levels, but more marked at the higher P level. In contrast, the metabolites reduced the width of the epiphyseal plate to an approximately similar degree, and this is possibly the reason why there are discrepancies between previous reports of the effectiveness of 1,25(OH)2D3 compared with 25OHD3 or vitamin D3. Dosing with 1,25(OH)2D3 failed to maintain a constant plasma Pi value over the period between doses in animals fed the low P diet.

Animals↗
PubMedDate not supplied

Cultured human retinal pigment epithelial cells differentially express thrombospondin-1, -2, -3, and -4.

Thrombospondins are a family of at least five proteins (TSP-1 to -4 and cartilage oligomeric matrix protein or COMP) whose functions are indeterminate. Distribution differences between family members suggest each protein may have some distinct functions. The retinal pigment epithelium (RPE) has divers unusual roles for an epithelia and can produce TSP-1. However, the wide range of RPE activities suggests that, if different thrombospondin family members do have different functions, RPE may express thrombospondins additional to TSP-1. Therefore, we analysed expression of thrombospondin isoforms by RPE using reverse-transcription-linked polymerase chain reaction. Cultured cells exhibited differential expression of TSP-1 to -4; TSP-2 and TSP-4 appearing later in culture than TSP-1 and TSP-3. In situ RPE expressed mRNA for TSP-1 to -4. No COMP mRNA was detected in RPE. These observations suggest that thrombospondin isoforms are regulated differently by the cells and that these proteins may have different functions in the RPE.

Adult↗