Search PubMed⌕ Search

Biomedical subjects

T Sakakura

Publications and source records attributed to T Sakakura.

At least 145 records · Page 8Linked to original sources
PubMed1976

Prevention of postthymectomy autoimmune thyroiditis in mice.

Several immunologic procedures are described, by which the postthymectomy autoimmune thyroiditis in (C3H/HeMs X 129/J)F1 female mice was clearly prevented. These include the grafting of a neonatal thymus or a cell injection from adult thymus, spleen, and lymph nodes, but not from bone marrow. Their preventive effects, however, depended on the timing of treatments. In general, the earlier the treatment was given, the better the effect was. Thymus cells from 7-day-old mice were effective, whereas spleen cells from the same donors and neonatal thymus cells were ineffective. Neonatal thymectomy or 500-rad irradiation decreased the number of effective cells in the spleen. All of these data suggest that the cells responsible for the prevention of postthymectomy thyroiditis are T-cells, and that ontogenetically these cells first acquire their preventive ability in the thymus after birth and then migrate to the peripheral lymphoid tissues. The minimal effective dose of adult spleen cells was 15 X 10(4). Although 10(7) spleen cells from the mice thymectomized 3 days after birth failed to prevent the disease, the same dose of cells from those thymectomized at 7 days clearly prevented it. This suggests that qualitative rather than quantitative differences exist in peripheral T-cells of mice thymectomized 3 days after birth and those of normal mice or mice thymectomized at 7 days when the animals get to adulthood.

Animals↗
PubMed1976

Spontaneous development of autoimmune thyroiditis in neonatally thymectomized mice.

An experimental mouse model of autoimmune thyroiditis induced by neonatal thymectomy (between 2 and 4 days of age) is described. Thymectomy within 24 hours after birth or thymectomy after 5 days of age failed to induce the disease. This type of thyroiditis occurred spontaneously a few months after the operation, lasted until approximately 12 months of age, and appeared to subside with aging. Hybrid mice of (C3H/He X 129)F1 are so far the most susceptible to neonatal thymectomy and the incidence in females (25 per cent) is significantly higher than that in males (6 per cent). Mice with thyroid lesions usually had circulating antibodies to mouse thyroid extract. Histologically, lymphocytes and plasma cells were the main cellular types of infiltrates and lymphoid follicles were seen in some cases. Interestingly, adenoma-like nodular hyperplasia of thyroid epithelium was observed in several thymectomized mice, with or without lymphoid infiltration. Besides those observed in the thyroid gland, lymphoid infiltrations were often observed in such organs as the ovary, the stomach, and the coagulating gland of thymectomized mice. These characteristics are compared with those of Hashimoto's thyroiditis and with those of its other animal models, and possible mechanisms which may be involved in the present disease are discussed.

Aging↗
PubMed1969

Thymus and reproduction: sex-linked dysgenesia of the gonad after neonatal thymectomy in mice.

Neonatal thymectomy of mice, when no ectopic thymus existed, constantly resulted in developmental arrest of the ovary but not of the testis; it also caused sterility in the female. The ovaries of thymectomized mice were extremely small and were characterized by absence of follicles and corpora lutea. Such an ovarian dysgenesia was observed when the mice were thymectomized at 3 days of age, but not at 7 days or later; it was prevented by thymus grafting.

Animals↗