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Biomedical subjects

M Ohtani

Publications and source records attributed to M Ohtani.

At least 235 records · Page 13Linked to original sources
PubMed1986

[Selection of treatment from a pathophysiological point of view. II: Studies on male urogenital tumors].

Testicular cancer is divided pathologically into two categories; seminoma and non-seminomatous germ cell tumor (NSGCT). Seminoma is a radio-sensitive tumor, so that radiation has been mainly used for stages I and II. Stage III seminoma is treated in the same way as NSGCT. Several years ago stages I and II NSGCT were treated primarily by retroperitoneal lymph node dissection. These days, chemotherapy, such as PVB, or VAB-6 therapy, is adopted as the first choice of treatment, followed by surgical intervention to elucidate the remaining bulky mass if present. Stage III NSGCT is also managed by chemotherapy. By these procedures 70-90% CR of patients with NSGCT is obtained. Prostatic cancer has been treated mainly according to its stages. As for stage A cancer palliative therapy has been shown to yield good results. However, in the case of poorly-differentiated tumors, local irradiation with anti-androgenic treatment should be employed. Stage B cancer should be treated by radical surgery. Local lymph node dissection is usually indicated. In addition local irradiation and anti-androgenic therapy should be considered. Most stage C or D patients do well for a while with antiandrogenic therapy. Within two or three years, however, drug resistance ensues, recessitating a change in the therapeutic modality. Treatments of choice include in chemotherapy, radiotherapy, and others. Treatment of penile cancer involves chemotherapy with bleomycin and irradiation, which result in considerable improvement.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1986

Evaluation of potential nephrotoxicity of antibiotics.

In order to assess the potential nephrotoxcity excerted by various antibiotics in therapeutic doses, the effects of antibiotics administered to Wistar rats in vitro and in vivo were investigated in terms of protein synthesis, nucleic acid metabolism, and lysosome stability. In vivo experiment protein synthesis was inhibited by SM, KM, GM and CL. RNA metabolism and stability of lysosomal enzyme, acid-phosphatase, were also disturbed by the aminoglycosides. In vitro experiments yielded almost the same tendencies. In our studies cephalosporins and related antibiotics had no influence upon the metabolism of RNA, protein synthesis and lysosomal enzyme.

Aminoglycosides↗
PubMed1986

Two cases of bladder carcinoma with similar initial features that exhibited completely different clinical courses.

Two cases of bladder carcinoma are described. The patients were of similar age, were both smokers and were treated for the same period, but exhibited completely different later clinical courses. Initially, both had a single, papillary, pedunculate tumor, identified as a transitional cell carcinoma, grade 2, pTa. One patient, six years later, had multiple papillary tumors covering almost all the mucosal surface and underwent simple cystectomy. Histologically the tumors were identified as transitional cell carcinomas, grade 2, pT1. The other patient, nine years later, had a single nodular invasive tumor with a concomitant, very tiny papillary tumor and underwent radical cystectomy. Histologically the tumor was transitional cell carcinoma, grade 2 greater than 3, pT4. Many of the questions raised by these cases are unanswered, but comparison of such cases should provide some clues to the natural history of bladder carcinoma.

Adult↗
PubMed1986

Primary neoplasm in a vesical diverticulum: analysis by step-sectioning.

A primary neoplasm arising in a vesical diverticulum was cystectomized and analyzed by step-sectioning of the whole bladder in an attempt to determine the carcinogenic process. Serial sections of the cystectomy specimen revealed a small area of mild dysplasia in the mucosa of the bladder and the diverticulum without a tumor. Most of the mucosal cells in the tumor-bearing diverticulum were desquamated, but a small area of dysplasia in the remaining cells was also observed.

Cystoscopy↗
PubMed1986

Sequential changes of mouse bladder epithelium during induction of invasive carcinomas by N-butyl-N-(4-hydroxybutyl)nitrosamine.

Invasive carcinoma of the bladder in humans shows aggressive growth with poor prognosis. Little is known about its preceding lesions. Sequential changes of the bladder epithelium following administration of N-butyl-N-(4-hydroxybutyl)nitrosamine (BHBN) were studied in mice. Female C3H/He mice were divided into 4 groups. Three groups were given 0.05, 0.01, and 0.005% concentrations of BHBN, respectively, in their drinking water, and the control group was given tap water. The mice were killed at regular intervals over a period of 26 weeks, and their bladder epithelium was examined histologically. Dysplasia, carcinoma in situ, and invasive carcinoma were observed sequentially in the groups treated with BHBN, and the incidences of dysplasia, carcinoma in situ, and invasive carcinoma were dependent on the dose of BHBN. The data indicate that bladder carcinoma in mice is a good model of invasive bladder carcinoma in humans, although it is not fully compatible with the human model because of the complete absence of metastases.

Animals↗
PubMed1985

Immunohistochemical detection of the gene product of Rous sarcoma virus in human brain tumors.

We have studied 108 cases of brain tumors by immunohistochemical staining utilizing an antiserum against the src gene product and GFA protein in order to elucidate the relationship between the brain tumors and the transforming genes. While the normal human brain tissues were not positive with the antiserum against the src gene product, several astrocytomas were clearly positive and other brain tumors were negative with the same. Src-gene product related peptide was detected in some of the human astrocytomas.

Astrocytoma↗
PubMed1985

Cyclosporin A enhances the survivability of mouse cerebral cortex grafted into the third ventricle of rat brain.

The effect of the immunosuppressant cyclosporin A on the survivability of newborn mouse cerebral cortex transplanted into the third ventricle of adult rats was investigated. Hematoxylin staining revealed that the transplanted mouse brain tissue was rejected by 4 weeks after the transplantation in the control group. In contrast, a large mass of grafted tissue was clearly detected in the third ventricle even 4 weeks after the transplantation in the cyclosporin A-treated group, and the grafted tissue was heavily stained with Thy-1.2 mouse monoclonal antibody. The results indicate that cyclosporin A is an effective immunosuppressant in neuronal transplantation as well as in transplantation of other organs.

Animals↗
PubMed1985

Significance of carcinoma in situ and dysplasia in association with bladder cancer.

Cystectomy specimens of 118 transitional cell carcinomas of the bladder were analyzed by step-sectioning. The carcinoma in situ and dysplasia adjacent to and remote from the visible bladder cancer were correlated with the tumor configuration on cystoscopy, and grade and stage of the disease. Results showed that a combination of papillary and nodular carcinomas in a single bladder was associated with a high incidence of mucosal involvement. Moreover, more than 50 per cent of all grade 3 carcinomas were associated with carcinoma in situ and dysplasia adjacent to and remote from the visible tumors. Carcinoma in situ and dysplasia were not related to the stage of disease. For management of bladder cancer, it appears important to assess the gross configuration of tumors by cystophotography and to determine the grade of tumors by biopsy, because mucosal involvement was found to be correlated closely with the tumor configuration and grade 3 disease.

Adult↗
PubMed1985

Synthesis of several new carbapenem antibiotics.

A synthesis of several carbapenem antibiotics including 9-methoxythienamycin is described. The final deprotection of C-3 esters was accomplished by a novel procedure using aluminum trichloride under a very mild condition. The antibacterial activity against Gram-positive and Gram-negative bacteria is shown.

Bacteria↗