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M Tanimoto-Weki

Publications and source records attributed to M Tanimoto-Weki.

At least 19 recordsLinked to original sources
PubMed1978

[Ultramicroscopic study of the invasion of the mucosa of the colon by Entamoeba histolytica in axenic cultures].

Animal models have been utilized to study experimentally produced intestinal amebiasis. The guinea pig has been the animal of choice to study the mechanisms by which trophozoites of E. histolytica produce colonic lesions. The purpose of this study was to produce lesions in the colon of newborn guinea pigs by the injection of E. histolytica, HM-1 IMSS, strain grown axenically, and to characterize the early changes with the light and electron microscopes. A total of 35 guinea pigs, one to two days old, were inoculated into the cecum with one and a half million of trophozoites of E. histolytica. Thirteen surviving animals were sacrificed. In four there were clear cut amebic lesions. Sections were taken from neighbouring transitional zones. The most important changes were the migrations of trophozoites to the bottom of colonic glands with many parasites located within the crypts. There was passage of ameabae to the lamina propia with practically no inflammatory reaction. It is thought that the parasite, in contact with epithelial crypt cell, produce direct lysis of these elements leading to migration of amebae into the lamina propia.

Animals↗
PubMed1977

[Ultramicroscopic study of the colonic mucosa infected by E. histolytica].

In eight guinea pigs, trophozoites of E. histolytica HM-2 IMSS strain grown in plurixenic conditions were inoculated in their cecum. Two died two days after inoculation; the remaining si- were sacrificed six days afterwards. Tissue samples were obtained from amebic lesions and nearby areas. At ultramicroscopic level it was observed that epithelial cells in contact with the parasite had short and/or scanty microvilli, swollen mitochondria, ER dilatation and absence of the terminal bar. When trophozoite was within the epithelium, cells in contact with it were destroyed; basement membrane was elongated before it was broken up by the parasite. In the lamina propria trophozoites were found close to glands, blood capillaries and in contact with macrophages, lymphocytes, and most cells. No polymorphonuclear cells were identified in all samples studied. Capillaries were congestive, lacking polymorphonuclear cells. It was postulated that probably initial colonic mucosa lesion in amebiasis depends solely upon parasite action.

Animals↗