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Biomedical subjects

S Usui

Publications and source records attributed to S Usui.

At least 181 records · Page 10Linked to original sources
PubMed1977

Effects of atropine upon the hippocampal electrical activity in rats with special reference to paradoxical sleep.

In freely moving male rats with implanted electrodes, the influence of atropine sulphate (5-30 mg/kg, i.p.) on the hippocampal theta activity was studied with special emphasis on paradoxical sleep (PS). In accordance with previous work with cats and rabbits, atropine was found to inhibit PS, in delaying its first appearance as well as in decreasing the duration of the first PS episode. The hippocampal theta activity during PS was also changed after atropinization. In particular, when REM occurred often, theta activity was increased not only in frequency but also in amplitude; however, with no or little REM, theta frequency was not changed but the regularity of theta rhythms was markedly disturbed. These findings are in contrast with the theta activity associated with gross body movement, which was not affected by atropine as was previous reported by Vanderwolf (1975). Thus, in contrast to commonly held views, the hippocampal theta activity during gross body movement may be different in its underlying mechanisms from that during PS.

Animals↗
PubMed1976

Effect of PS-K, a protein polysaccharide, on pulmonary metastases of a C3H mouse squamous cell carcinoma.

We studied the effects of PS-K, a protein polysaccaride isolated from a basidiomycete, on the formation of blood-borne metastases. Experimental tumors were fifth-generation isotransplants of a spontaneous C3Hf mouse squamous cell carcinoma that was weakly antigenic. A single-cell suspension from fourth generation tumors was transplanted, and the tumor-bearing legs of the mice were amputated when transplants reached a certain diameter. Daily administrations of PS-K followed immediately, and both lungs were excised on the 21st postamputation day. The number of lung colonies formed on the surfaces of both lungs was counted and total volumes of metastatic colonies were estimated. PS-K, if administered alone, did not inhibit the lung colony formation. Marked reduction in this formation was observed when five daily doses of PS-K were administered simultaneously with cyclophosphamide. These observations indicate that PS-K may be a potent agent in the therapy of cancer if used as an adjuvant to a chemotherapeutic agent.

Animals↗
PubMedDate not supplied

Prognosis of hepatocellular carcinoma smaller than 5 cm in relation to treatment: study of 100 patients.

A total of 100 patients with small hepatocellular carcinoma, less than or equal to 5 cm in diameter, seen during the last 8 years were analyzed retrospectively for survival time in relation to treatment and Child's grading. When analyzed with respect to major treatment modalities without considering stage, the median survival was 35.0 months for 34 patients treated by surgery, 28.8 months for 20 patients treated by transcatheter arterial embolization, 10.6 months for 25 patients treated by intraarterial chemotherapy and 9.7 months for 17 patients who received no specific treatment. When patients were divided into three stages without considering treatment, the median survival was 37.1 months for 37 Child's A patients, 16.2 months for 36 Child's B patients and 1.6 months for 27 Child's C patients. These results suggest that the prognosis depended on treatment given and the Child's grade. The effects of major therapeutic modalities on survival were analyzed with regard to Child's grading. Among Child's A patients, the actuarial survival rate for surgery was better than that for transcatheter arterial embolization and for arterial chemotherapy. Among Child's B patients, the survival rate for transcatheter arterial embolization was better than for other treatments. Among Child's C patients, there was no significant difference in survival rate regardless of treatment and its modality. These results suggest that surgery may be indicated as a first choice in Child's A patients, transcatheter arterial embolization in Child's B patients, and there is no effective treatment in Child's C patients. The major cause of death was hepatic failure irrespective of treatment.

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