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R Hembry

Publications and source records attributed to R Hembry.

5 recordsLinked to original sources
PubMed1999

Evaluation of some newer matrix metalloproteinases.

Recombinant protein expression techniques have been utilized to facilitate the biochemical and cell biological characterization of human matrix metalloproteinases (MMPs). The importance of the membrane type 1 MMP (MMP 14) in the regulation of pericellular proteolysis, either directly or through the activation of MMP-2, MMP-9, and MMP-13 has been identified. Studies on an in vitro chondrocyte-like cell and an in vivo cartilage repair model indicated that such MT1 MMP-regulated activation cascades are physiologically feasible. MMP19 shows a limited sequence identity with other MMPs and may represent a novel subclass. However, analysis of the recombinant protein identified a number of biochemical properties typical of the MMP family.

Animals↗
PubMed1997

Effect of methylprednisolone on the ulceration, matrix metalloproteinase distribution and eicosanoid production in a model of colitis in the rabbit.

This study has examined the response of a rabbit model of inflammatory bowel disease to methylprednisolone. Colitis was induced in the colon of rabbits with 40 mg trinitrobenzenesulphonic acid in 25% ethanol (TNBS). The effect of methylprednisolone (0.5 mg/kg/day) on the development of colitis was determined at one week, by examining the colon's macroscopic and microscopic appearance, the distribution of matrix metalloproteinases (MMPs) and by measuring eicosanoid production. Although there was no difference in the area of ulcerated colonic tissue in the treated and untreated TNBS animals, the increase in polymorphonuclear leucocytes was significantly reduced in TNBS rabbits given methylprednisolone. The only difference in the distribution of MMPs was a reduction in the number of polymorphonuclear leucocytes containing gelatinase B. The release of immunoreactive PGE2 and LTB4, but not 6-keto PGF1 alpha, was increased in the TNBS animals and was unchanged by methylprednisolone. These results show that methylprednisolone does not modify the injury produced by TNBS in this model despite reducing the infiltration of polymorphonuclear leucocytes. Hence it suggests that these cells do not contribute to the injury observed, are not the source of the eicosanoids and that gelatinase B is not required in the healing process in this model.

6-Ketoprostaglandin F1 alpha↗
PubMed1991

Localization of stromelysin gene expression in atherosclerotic plaques by in situ hybridization.

The stromelysins are members of a family of extracellular matrix metalloproteinases. These enzymes may erode the connective tissue in atherosclerotic plaques, leading to fissuring and acute thrombotic events. Cell-specific stromelysin expression in human atherosclerotic plaques was studied by in situ hybridization and immunocytochemistry. Sections were taken from nine coronary arteries: eight with well-established plaques and one normal. Unambiguous signals were seen in five plaques, two were inconclusive, and the remaining sample was negative, as was the normal coronary artery. Stromelysin mRNA transcripts were localized to isolated individual cells, some of which were smooth muscle, in the plaque cap, intima, and adventitia, but not the media. Expression was also seen in large clusters of macrophages that contained intracellular lipid deposits. The isolated expression of stromelysin by smooth muscle cells may reflect local connective tissue remodeling associated with growth and the formation of the plaque, whereas the more extensive expression associated with macrophages may be of greater pathological significance, contributing to the destabilization of the extracellular matrix and eventual plaque rupture.

Arteriosclerosis↗
PubMed1979

A cartilage catabolic factor from synovium.

Porcine synovium in organ culture produces a factor that causes chondrocytes to degrade their matrix. A quantitative assay for the factor, for which the cartilage of bovine nasal septum is used, is described. Evidence is presented that the catabolic factor is a protein.

Animals↗