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Biomedical subjects

Y Hamada

Publications and source records attributed to Y Hamada.

At least 523 records · Page 29Linked to original sources
PubMed1983

[Combination chemotherapy with mitomycin C, methotrexate, and vincristine (MMV) for metastatic breast cancer refractory to adriamycin].

Twenty-five patients with metastatic breast cancer who had failed with combination chemotherapies including adriamycin were treated with a combination of mitomycin C, methotrexate, and vincristine (MMV). MMC 5 mg/m2, methotrexate 18 mg/m2, vincristine 0.7 mg/m2 were given i.v. on days 1 and 8, and repeated every 21 days. Seven patients (28%) experienced a partial response: 7 maintained NC and 11 failed to respond (PD). Median duration of regression was 12 weeks. Median survival time in PR patients was one year and 3 months, contrary to 6 months in patients with NC or PD. This combination was well tolerated except thrombocytopenia in 5 patients.

Adult↗
PubMed1983

[Role of the spleen in tumor immunity--with special reference to anti-tumor immunity induced by solubilized and purified tumor-associated antigen].

The effects of post-operative immunization with purified tumor-associated antigen on the development of lung metastases following resection of the Lewis lung carcinoma (3LL) were studied. The soluble tumor-associated antigens were isolated from 3LL cells by detergent solubilization and purified by affinity chromatography on peanut agglutinin (PNA)-agarose. The immunization with subcutaneous injections of PNA-binding glycoproteins at early phase following resection of primary footpad tumors of 3LL resulted in a significant decrease in incidence and size of lung metastases. The delayed immunization, however, failed to suppress the development and growth of metastatic lung tumors after surgery. The suppression of postoperative development of lung metastases was found to depend on timing of immunization following local tumor resection. Splenectomy performed simultaneously with amputation of tumor-bearing leg was completely abolished the decrease in the development and growth of postoperative lung metastases in immunized-mice. Evidence of lymphoid system involvement in the control of metastatic tumor growth was also supported by the observation of in vivo tumor neutralization assay utilizing the spleen cells.

Animals↗
PubMed1983

[Evaluation of steroid hormone sensitivity of human breast cancer cells in culture (MCF-7) by a colony formation method].

The effects of steroid hormones on the colony forming activity of a human breast cancer cell line (MCF-7) were studied. Endrogeneous estrogens in the fetal calf sera used for culture were deprived using the dextran-coated charcoal, and only batches of E2-deprived serum were chosen with which there was a significant increase in the plating efficiency after E2 (estradiol-17 beta, 10(-8) M) treatment. Progesterone showed little effect on the growth of the cells. not being influenced by the addition of E2. The capacity of the cells to form colonies was stimulated by androgens (5 alpha-dihydrotestosterone, testosterone) only in the absence of E2. Dexamethasone had suppressive effects regardless presence of E2. Thus, MCF-7 cells showed variable responses to these steroid hormones, although the cells have specific receptors to the hormones. This colony formation method of MCF-7 cells may be a useful model system for the study of hormonal and non-hormonal anti-cancer agents.

Breast Neoplasms↗
PubMed1982

Phage particle-mediated gene transfer to cultured mammalian cells.

Recombinant phage particles carrying the thymidine kinase (TK) gene of herpes simplex virus type 1, coprecipitated with calcium phosphate, efficiently transformed mouse Ltk- cells to the TK+ phenotype. The conditions necessary to achieve high efficiency of transfer of the TK gene by phage particle-mediated gene transfer were investigated. Of the parameters examined, the pH of the buffer used for coprecipitation of phage particles with calcium phosphate, the length of time of coprecipitation, and the length of the adsorption period were found to alter the transfer efficiency significantly. The optimal pH was 6.87 at 25 degrees C. The other optimal values for these parameters were as follows: coprecipitation time, 7 to 20 min; adsorption time, 18 to 30 h. Treatment with dimethyl sulfoxide, glycerol, or sucrose did not enhance gene transfer. The optimal conditions yielded about 1 transformant per 10(5) phage particles per 10(6) cells without carrier DNA. An increase in the dosage of phage particles, up to at least 5 x 10(7) phage particles per 100-mm dish, resulted in a linear increase in the number of transformants. Addition of carrier phage, up to 10(10) phage particles per dish, did not significantly affect the number of transformants.

Adsorption↗
PubMed1982

[Tissue levels of bleomycin administered as suppository].

We prepared a bleomycin suppository, aiming not only at allowing bleomycin to be transferred into the malignant tumor tissue of the intrapelvic organs and their regional lymph nodes at high levels but also at preventing transient elevation of its level in the blood. This administration route might be effective on the primary lesions of urogenital malignant tumors and their metastases to the regional lymph nodes, and prevent systemic adverse reactions. To prove these effects, we determined the levels of bleomycin in the tissue, blood, lymph nodes, urine and stools following intrarectal application of the bleomycin suppository. The pattern of bleomycin uptake by the intrapelvic tissues showed that the drug was retained by tumor tissue at high levels for a long time, compared with that by the normal tissue. Its levels in the blood suggested the reduction in systemic adverse reactions. Its uptake by the regional lymph nodes was unexpectedly low, but this may be attributed to an early collection of the tissue after the application. We think it necessary to follow up changes in bleomycin level in the tissues collected at predetermined intervals.

Adult↗