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Biomedical subjects

K Toyama

Publications and source records attributed to K Toyama.

At least 523 records · Page 29Linked to original sources
PubMed1980

Heterotopically induced osteogenesis in osteopetrotic rat mutants. A preliminary report.

Heterotopic osteogenesis was induced in three groups of Fatty Orl-op strain of rats, i.e., osteopetrotic (op/op) mutants, op/op mutants cured by previous transplants of normal bone marrow, and phenotypically normal littermates. Allogenic decalcified bone matrix was used as inductor. The osteopetrotic mutants from heterotopic ossicles containing bone and bone marrow under the influence of inductor. After four weeks the signs of remodelling processes of induced bone tissue are observed: osteoclasts are found in the Howship lacunae, and bone marrow is formed in the spaces adjacent to the bone trabeculae. The induced bone marrow contains megakaryocytes, cells of the erythropoietic and granulopoietic lines as well as some infiltrating lymphocytes. The important finding is that the amount and the histological structure of bone tissue and bone marrow induced heterotopically in the osteopetrotic animals were similar to that observed in both control groups. It is concluded that 1) osteopetrotic mutants have the same potency to form heterotopic bone tissue under the influence of inductor as the control animals, and 2) remodelling processes in four-week-old, induced ossicles are normal and differ in this respect from defective rebuilding of the orthotopic bones of op/op hosts.

Animals↗
PubMed1979

Role of reduced glutathione on platelet functions.

The role of reduced glutathione (GSH) on platelet functions was investigated utilizing thiol oxidizing agent, "diamide". Diamide reacted rapidly with GSH in platelets, but not with protein thiols. Platelets treated with diamide showed inhibition of platelet aggregation induced by ADP, epinephrine and collagen in a concentration dependent manner. Clot retraction was grossly inhibited by diamide. Platelet interaction with polymerizing fibrin was examined by the method of Niewiarowski et al. (1972). There was no interaction obeserved between diamide-treated platelets and polymerizing fibrin. Ultrastructural observation of clots formed in the presence of diamide also showed no direct contact between platelets and fibrin strands. Platelets retained their granular contents, but showed loss of microtubules and dilatation of open canalicular system. Our findings may further support the idea that GSH plays an important role on platelet functions.

Adenosine Diphosphate↗