Search PubMed⌕ Search

Biomedical subjects

T Yuasa

Publications and source records attributed to T Yuasa.

At least 253 records · Page 14Linked to original sources

beta-Cyclodextrin: promoting effect on the development of renal tubular cell tumors in rats treated with N-ethyl-N-hydroxyethylnitrosamine.

Injection (sc) of beta-cyclodextrin (beta-C) increased the number and size of renal tubular cell tumors in inbred Wistar (W) rats treated with 1,000 ppm of N-ethyl-N-hydroxyethylnitrosamine (EHEN). The incidence of renal tumors at the end of the 32-week experiment was 50% in rats treated with 1,000 ppm EHEN for 2 weeks and 100% in rats treated with 1,000 ppm EHEN for 2 weeks and then given daily sc injections of beta-C for 1 week. The incidence of renal tumors more than 3 mm in diameter was 70% in rats treated with 1,000 ppm EHEN before beta-C but 0% in rats treated with EHEN alone. In addition, beta-C promoted the development of renal tumors in rats treated with 500 ppm EHEN, which is a subthreshold dose for renal tubular cell tumorigenesis. These results show that beta-C promotes EHEN-induced renal tubular cell tumorigenesis.

Animals↗

[Suprasellar arachnoid cyst--report of a case (author's transl)].

A 4-year-old boy with suprasellar arachnoid cyst was reported. At the age of 30-month-old his aunt was aware of his squint. During the observation by ophthalmologists from the age of 1y. to 3y., enlargement of the head and impairment of the visual acuity were manifested. Cranial CT scan revealed the enlargement of the ventricular system and a round low density area located superior to the sella. Absorption coefficient of the lesion was similar to that of the cerebrospinal fluid. No abnormal contrast enhancement was seen. Examination revealed the head circumference of 53.3 cm larger than doubled standard deviation, the right external strabismus, impaired vision (R:0.03, L:0.3) and optic atrophy but no other neurological signs. Cerebral angiography showed suprasellar mass lesion. After the ventriculography with water-soluble contrast medium, V-P shunt operation was performed and then the patient was transferred to the CT room. CSF enhanced CT scan showed no communication between the ventricles and the cyst. By frontotemporal approach, microsurgical removal of the cystwall was performed and the histological diagnosis was arachnoid membrane. Several days after the operation, bilateral subdural effusion was seen on CT scan and was treated with bilateral S-P shunt and the removal of V-P shunt. Follow up CT scan disclosed the disappearance of the subdural effusion and the suprasellar cyst. The visual acuity was improved well and the endocrinological study was normal. Analysis of the 45 reported cases of suprasellar arachnoid cyst suggested that direct removal of the cyst wall is better than the V-P shunt operation and the cyst shunting is advisable for repeat recurrence of the cyst. Removal of the ventricular shunting system may be effective for the prevention of the subdural effusion as a complication after direct operation.

Arachnoid↗

Exophthalmos in autoimmune thyroid disease.

Protrusion of the eyes of patients with autoimmune thyroid disease was compared with that of healthy subjects. The mean values for protrusion in patients with thyrotoxic Graves' disease and Hashimoto's disease and in healthy subjects were 16.6 +/- 2.1 mm (mean +/- SD; n = 122), 14.2 +/- 1.8 mm (n = 100), and 13.9 +/- 1.9 mm (n = 558), respectively. The value of Graves' disease was significantly different from that for healthy subjects (P < 0.001). Individual values for protrusion showed a similar normal distribution in these three groups, but were displaced to higher values as a whole in Graves' disease. These results, which suggest that almost all patients with Graves' disease have exophthalmos, do not support the idea that Graves' ophthalmopathy is a distinct single autoimmune disease.

Autoimmune Diseases↗

Cultured skin fibroblasts in lipidoses. Enzymatic, histochemical, and ultrastructural relationship in Fabry's Tay-Sachs, and Sandhoff's diseases.

Enzymatic, histochemical, and ultrastructural studies were performed on cultured skin fibroblasts from patients with Fabry's disease, Tay-Sach's disease, and Sandhoff's disease and from their families (carriers). alpha-Galactosidase activity was deficient in the proband with Fabry's disease (lower in the homozygotes than in the heterozygote). Levels of hexosaminidase A in the patient with Tay-Sachs disease and hexosaminidase A and B in the patient with Sandhoff's disease were deficient and were lower in her mother than in the control subject. Lysosome-like structures were observed in cultured fibroblasts from the patients with each disease, as well as in the heterozygote with Fabry's disease and the carrier with Tay-Sach's disease. The amount of the accumulating arrays in the lysosome-like structures was related to low level of enzymatic activity.

Cells, Cultured↗