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Biomedical subjects

H Asakura

Publications and source records attributed to H Asakura.

At least 451 records · Page 25Linked to original sources
PubMed1975

Characterization of bleomycin action on DNA.

Cleavage of SV40 DNA by bleomycin was assayed quantitatively in vitro in the presence of various ppolynucleotides. SV40 DNA was protected from bleomycin- duced cleavage by native or denatured DNA of other origins, oly dG-C.poly dG-C, poly dA-T.poly dA-T and poly dA-T (denatured) but not by tRNA of E. coli, apurinic acid, poly dA, poly dT and various deoxyribooligonucleotides. Various bleomycins and their derivatives and various fragments of bleomycin were tested for possible activity in cleaving SV40 DNA and from the results some structure-activity relationships for the action of bleomycin to act on DNA were outlined. Actinomycin D stimulated bleomycin action while ethidium bromide inhibited it.

Animals↗
PubMed1975

Radiographic and endoscopic features of colonic ulcers in systemic lupus erythematosus.

The radiographic and endoscopic features of the colonic ulcers during the course of a case of systemic lupus erythematosus are illustrated. Barium enema revealed the "collar button" type of penetrating ulcers in the left half of the colon and endoscopy demonstrated multiple round- or oval-shaped discrete ulcers, so-called "punched-out" ulcers with pale mucosa. These findings are compared with those of the reported cases of systemic lupus erythematosus and ulcerative colitis. Steroid and 6-mercaptopurine therapy was effective in this case.

Adult↗
PubMed1974

Electron microscopic study on the jejunal mucosa in human cholera.

Small intestinal mucosa obtained from six fasting patients with cholera by a peroral biopsy technique was studied with the electron microscope. The cultures of their rectal swabs were all positive for Vibrio cholerae. In the absorptive cells, large pseudopod-like cytoplasmic processes with deformed microvilli or without microvilli (blebs) projected into the intestinal lumen from the apical cell surface, interrupting the microvillous border. In the crypts some of the undifferentiated crypt cells possessed pseudopod-like cytoplasmic projections which extended into the crypt lumen. The swelling of mitochondria, the disappearance of their cristae, an increase in the number of vesicles of the Golgi apparatus, and the dilatation and vesiculation of endoplasmic reticulum were observed in the epithelial cells. The apical portion of the cells became oedematous in some of the epithelial cells. Cytoplasmic fragments enclosed by a plasma membrane, desquamated epithelial cells, cytoplasmic organelles, and secretory granules were lying free in the intestinal lumen.Marked irregular widening of the interepithelial spaces in the jejunal mucoa was observed at the midvillous area. Many cystic vacuoles were present in the cytoplasm of epithelial cells. The possibility of fluids being transported from blood vessels to intestinal lumina through the interepithelial spaces, and the significance of these pathological findings in human cholera are discussed in this study.

Adult↗
PubMed1973

Histopathological and electron microscopic studies of lymphangiectasia of the small intestine in Behçet's disease.

The gastrointestinal involvement and immunological findings in 16 patients with Behçet's disease are described. Four of 15 biopsy specimens of jejunal mucosa showed marked lymphangiectasia in the lamina propria similar to the appearance which was thought to be a characteristic finding in protein-losing enteropathy. None of the patients had hypoproteinaemia. Increases in serum immunoglobulin IgA were proved in six of 15 cases; in IgM, five of 15; and in IgG, one of 15. Electron microscopic studies showed that there were thousands of precipitated lymph protein bodies in the extracellular spaces of the lamina propria. Ulcers and healed ulcers of the large intestine were studied by light microscopy.

Adult↗