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Biomedical subjects

S Sakaguchi

Publications and source records attributed to S Sakaguchi.

324 records · Page 18Linked to original sources
PubMed1969

Significance of 12S toxin of Clostridium botulinum type E.

The pathogenesis of type E botulism is discussed as an aspect of the physicochemical and biological properties of 12S toxins (prototoxin and trypsin-activated 12S toxin) and the Ealpha and Ebeta components of each 12S toxin. A molecular weight of 350,000 was determined for each 12S toxin and 150,000 for Ealpha and Ebeta. Owing to the structure comprising the subunits Ealpha and Ebeta, 12S toxins are much more stable than Ealpha at low pH values and high temperatures. Such was also the case with type A 19S toxin and its alpha component. The Ealpha component alone accounts for the total toxicity of type E toxin. The toxic substance detected in the blood of the animals administered 12S toxins orally or parenterally was identified as Ealpha from the molecular size and the chromatographic pattern. Prototoxin escaping from detoxification in the stomach owing to the subunit structure may undergo dissociation in the intestine to release the Ealpha component. After absorption, the activated Ealpha appeared in the circulating blood without any further signs of dissociation or enzymatic digestion.

Animals↗
PubMedDate not supplied

The roles of CD25+CD4+ regulatory T cells in operational tolerance after living donor liver transplantation.

UNLABELLED: Recent evidence suggests that CD4+CD25+ regulatory T cells (Tregs) affect immune responses, including those to alloantigens in organ transplants. We have followed a group of liver allograft recipients with good liver graft function who have been weaned off immunosuppression (IS). The purpose of this study was to determine whether Tregs contributed functionally to the mechanisms of graft acceptance. MATERIAL AND METHODS: The functional assay used peripheral blood obtained from LTx recipients free of immunosuppression. The Whole population of CD4+ T cells and the CD4+ T cells depleted of CD4+CD25 high cells were tested for proliferation against donor versus third party stimulators. Moreover to determine the antigen-specificity of the Tregs, serially diluted numbering of CD4+CD25+ T cells were co-cultured with CD4+CD25- T cells. The proliferation responses were examined toward donor versus third party stimulators. RESULT: CD4+ T cells from all LTx recipients off immunosuppression showed hyporesponsiveness to the donor but not to third party stimulators. However, even after depletion of the CD4+CD25 high population, the cells continued to be hyporesponsive toward the donor. In four out of five cases, the suppression exhibited by CD4+CD25+ T cells was more specific for the donor. DISCUSSION: These findings suggest that donor alloantigen specific regulation by Tregs is one of multiple mechanisms that may contribute to the maintenance of liver graft survival in the absence of immunosuppression.

Antigens, CD↗
PubMedDate not supplied

Ageing of the vibratory tissue of human vocal folds.

Sixty-four human larynges ranging in age between 70 and 104 years were investigated histologically. The results were incorporated into our previous data for younger age groups. Discussion was focused on the mucosa around the vocal fold edge. The following tendencies were observed with ageing: (1) the membranous vocal fold shortens in males; (2) the mucosa thickens in females; (3) the cover of the vocal fold thickens in females; (4) edema develops in the superficial layer of the lamina propria in both sexes; (5) the intermediate layer of the lamina propria thins and its contour becomes deteriorated in males; (6) elastic fibers in the intermediate layer become less dense and atrophy in males; (7) the deep layer of the lamina propria thickens in males; (8) collagenous fibers in the deep layer become denser and fibrotic in males. The degree of these geriatric changes vary from individual to individual.

Aged↗
PubMedDate not supplied

Advance in phlebology in Japan.

Vascular surgery has recently been witnessing remarkable progress in Japan, supported in part by an increase in the number of researchers. Although the actual researchers specializing in the field of phlebology are much fewer in Japan as opposed to the West because of a seemingly lesser number of patients suffering from venous diseases particularly those which are fatal, the participants in the annual meetings of the Japanese Society of Phlebology have shown a gradual increase since 1980. Notably, the 9th World Congress of Phlebology was held in late September 1986 in Kyoto with a great many global authorities giving lectures, presenting papers and discussing a wide range of topics with the 600 participants attending. This event markedly stimulated our phlebologists and will undoubtedly contribute to enhancing the level of phlebology in Japan. This positive environment was also given an earlier boost in 1985 by the Japanese Ministry of Health and Welfare establishing a study group for angiology including phlebology and lymphology. The activity of this group may be a important foundation for the most significant advances in phlebology in Japan.

Humans↗
PubMedDate not supplied

Haemopathological changes in recurrent deep venous thrombosis of the extremities.

We observed 42 (11.7%) patients with multiple or recurrent thrombosis in 358 patients with deep venous thrombosis of the extremities (DVT) and its sequelae. In those patients with recurrent DVT, following characteristics were found in comparison with patients with recurrent DVT, following characteristics were found in comparison with patients who experienced only one episode of DVT. Collagen disease including Behçet disease are often observed as an important predisposing factor. Relatively high incidence in the young generation. Pulmonary embolism occurred about 4 times as frequent as in patients with single episode of DVT. The platelet adhesiveness increased in 7 (38.9%) cases and the hyperaggregability was also frequently found (34.8% by ADP, 26.1% by collagen), though no significant differences was noted from patients with single episode of DVT. Meanwhile, beta-thromboglobulin increased an antithrombin III decreased with a significant difference. DVT with those characteristics should more carefully be managed.

Adolescent↗