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Biomedical subjects

S Onizuka

Publications and source records attributed to S Onizuka.

24 records · Page 2Linked to original sources

A phase II study of prophylactic intravesical chemotherapy with epirubicin in the treatment of superficial bladder cancer. Tokyo Women's Medical College Bladder Cancer Collaborating Group.

Intravesical instillation of epirubicin was carried out to investigate the efficacy of this treatment in preventing postoperative recurrence of superficial bladder cancer. The subjects were 100 patients who had been treated with transurethral resection (TUR) for superficial transitional-cell carcinoma of the bladder (classified as primary or recurrent superficial bladder cancer of pathological stage Tis, Ta, or T1 and histological grade G1, G2, or G3) at Tokyo Women's Medical College Hospital and its affiliated hospitals during the 2-year period ranging from April of 1990 through March of 1992. A solution of epirubicin was prepared by dissolving 20 mg in 30 ml physiological saline, and this was instilled into the bladder a total of 17 times during 1 year: once immediately after TUR, once every 2 weeks for the next 4 months, and then once per month for the following 8 months. Thereafter, the course of each patient was followed by performing urinary cytodiagnosis once each month and cystoscopy once every 3 months. Of the 100 patients, 83 were evaluable. The mean duration of follow-up was 461 +/- 222 days, and the recurrence rate was 30.1% (25/83 cases). The recurrence rate determined for primary cases was 19.7%, whereas that recorded for recurrent cases was 61.9%. Adverse effects occurred in 9.3% (9/97) of the patients, but these side effects were mild in severity and the instillation regimen did not have to be discontinued in any of the patients. Analysis of the risk factors for recurrence revealed significantly higher recurrence in the recurrent-patient group and the multiple-tumor group. On the basis of these findings, the authors surmised that when given in an intravesical instillation regimen, epirubicin causes few adverse effects, and its efficacy in the prophylaxis of recurrence of superficial bladder cancer is equivalent to that thus for reported for other drugs. At present, the authors are carrying out a controlled clinical study on epirubicin that takes into account the risk factors for recurrence of superficial bladder cancer.

Administration, Intravesical↗

Spontaneous pancreatitis in spontaneously hypertensive rats.

The pancreatic lesions in 6- to 36-week-old spontaneously hypertensive rats (SHR), stroke prone SHR (SHRSP) and Wistar-Kyoto rats (WKY) were examined histopathologically. Inflammatory cell infiltration with hemorrhage and stromal fibrosis became evident in 12-week-old SHR and SHRSP together with acinar atrophy and/or degeneration and ductular proliferation. These changes in SHR and SHRSP were even more prominent at the age of 24 weeks and extremely severe at 36 weeks. In addition, in SHR and SHRSP over 12 weeks of age, small necrosis of acinar cells was found occasionally together with fibrosis and arteriosclerosis. Pancreatic arteriosclerosis was marked in SHR and SHRSP over 24 weeks of age at the level of arterioles < 200 microns in diameter. Adrenergic nerve fibers stained by fluorescence histochemistry were present around the pancreatic arteries and ducts and within the parenchyma, and they were denser in SHR and SHRSP than in WKY, indicating hyperinnervation of the sympathetic nervous system in SHR and SHRSP. It is suggested that the pancreatic ischemia caused by arteriosclerosis due to facilitation of the sympathetic nervous system is an important factor in the pathogenesis of the spontaneous pancreatitis of SHR and SHRSP.

Animals↗

Osteoclast-like giant cell tumour of the gallbladder.

We describe a rare carcinoma of the gallbladder containing osteoclast-like giant cells. Well-differentiated adenocarcinoma was found in the mucosa of the fundus, and osteoclast-like giant cells were present mainly in a haemorrhagic mass protruding from the mucosal surface. The metastatic hepatic tumour was composed chiefly, if not exclusively, of osteoclastoma-like cells, but minute carcinomatous elements were also present. There was an apparent transition between the giant cells and tubular structures in both the gallbladder tumour and hepatic tumour. However, ultrastructural study did not reveal any evidence of epithelial differentiation in the giant cells. Immunohistochemical studies suggested that the mononuclear and giant cells were mesenchymal and histiocytic in nature (vimentin and factor XIIIa positive). A few exceptional giant cells transforming from the fine tubular structure were positive for epithelial membrane antigen. In conclusion, the osteoclast-like giant cell tumour component was thought to represent mesenchymal metaplasia in pre-existent adenocarcinoma.

Adenocarcinoma↗

A case of ornithine transcarbamylase deficiency with acute and late onset simulating Reye's syndrome in an adult male.

A 15-year-old male was admitted to the hospital because of a disturbance of consciousness. He was in good mental and physical condition until the previous day, when he vomited and experienced a reduction of consciousness. He was brought to the hospital the day following the onset of symptoms. On admission the patient was stuporous. Neurological focal signs were not demonstrated. Computed tomographic (CT) scanning on admission showed no definite abnormality. Cerebrosprinal fluid had no pleocytosis. At this time, Reye's syndrome was suspected because of the acute change of consciousness and the presence of hyperammonemia. The disturbance of consciousness progressed and he became comatose on the day following admission. CT scanning showed that the suprasellar, ambient and quadrigeminal cisterns could almost not be detected and the bilateral ventricles were narrowed. The plasma aminogram demonstrated an elevation of alanine, lysine, glutamine, glutamic acid, aspartate and proline. Ketonuria was negative, but the urinary excretion of orotic acid was markedly increased. This data was indicative of the existence of an ornithine transcarbamylase (OTC) deficiency. The patient was died on the third day after hospitalization. The OTC activity in the liver was 10% of normal. Activities of other enzymes in the urea cycle were within normal limits. It is unusual that the symptoms of the enzyme deficiency occurred, both acutely and late at an adult age, as in this case. This case demonstrates that OTC deficiency should be considered in the differential diagnosis of hyperammonemia of adult onset.

Adolescent↗

Extraskeletal myxoid chondrosarcoma arising from the retroperitoneum.

A case of extraskeletal myxoid chondrosarcoma is presented. The tumor occurred in the retroperitoneum and systemic metastases were found at autopsy. The primary and metastatic tumors were soft and strikingly myxoid on gross appearance. Microscopic observation revealed undifferentiated malignant tumor having large amounts of myxoid substance and a small amount of well-differentiated chondrosarcoma element in the primary lesions. The authors obtained an immunohistochemical result that the tumor cells showed positivity for alpha-1-antitrypsin and alpha-1-antichymotrypsin. Regarding S-100 protein, the well-differentiated chondrosarcoma element revealed intense positivity, whereas the poorly differentiated myxoid areas were not positive except for a few tumor cells. This is the first case, to our knowledge, of extraskeletal myxoid chondrosarcoma arising from the retroperitoneum, and immunohistologic findings suggest that alpha-1-antitrypsin and alpha-1-antichymotrypsin may be available markers in poorly differentiated chondrosarcomas showing a negative reaction for S-100 protein.

Chondrosarcoma↗