vitamin-b-12 and Testicular-Neoplasms

To compare tests for intestinal function with clinical scores after abdominal irradiation.. At the Department of Radiotherapy, Erfurt, Germany, intestinal changes were studied in 91 patients receiving abdominal radiotherapy between 1992 and 1996. Conventional fractionation (1.8-2 Gy per fraction, total doses 30.6-62.5 Gy) was applied. Before and at weekly intervals during radiotherapy, the clinical response was scored according to RTOG/EORTC for the upper and lower gastrointestinal (GI) tract. Resorption tests for vitamin B(12) and D-xylose were performed before the onset and immediately after treatment.. The clinical response displayed a well-defined dose-effect relationship with grade 1 effects in 5% and 50% of the patients at about 10 Gy and 50 Gy, respectively. For grade 2 reactions, 5%- and 50%-effective doses were 20-30 Gy and 60-80 Gy. Effects in the upper and lower GI tract were highly correlated. Changes in body weight did not show a correlation with other clinical symptoms. Changes in resorption also displayed a significant dose effect. However, no correlation was found with the clinical symptoms in the individual patient.. In the present study, the clinical manifestation of intestinal side effects according to RTOG/EORTC criteria was reflected by neither the vitamin B(12) nor by the D-xylose resorption test. Hence, these tests cannot be regarded as useful for objective quantitation of intestinal radiation injury.

Topics: Abdomen; Adolescent; Adult; Aged; Dose Fractionation, Radiation; Dose-Response Relationship, Radiation; Female; Hodgkin Disease; Humans; Intestinal Absorption; Intestines; Kidney Neoplasms; Lymphoma, Non-Hodgkin; Male; Middle Aged; Prospective Studies; Radiation Injuries; Radiotherapy; Radiotherapy Dosage; Rhabdomyosarcoma; Seminoma; Stomach Neoplasms; Testicular Neoplasms; Time Factors; Vitamin B 12; Xylose

Methylcobalamin is one of the coenzymatically active cobalamin derivates and required for the activity of the cytoplasmic enzyme methionine synthetase catalyzing the methylation of homocysteine into methionine. The effect of methylcobalamin on the proliferation of malignant cells has been examined. Methylcobalamin inhibited the proliferation of androgen-sensitive SC-3 cells (a cloned cell line from Shionogi mouse mammary tumor, SC115) in culture at the concentration of 100-300 micrograms/ml. An inhibitory activity of methylcobalamin on the proliferation was also observed in other cell lines (estrogen-sensitive B-1F cells from mouse Leydig cell tumor and MCF-7 cells from human mammary tumor) at the concentration of 500 micrograms/ml. Moreover, large doses of methylcobalamin injected intraperitoneally (100 mg/kg body weight/day) were non-toxic and suppressed the tumor growth of SC115 and B-1F cells in mice fed a vitamin B12 deficient diet. These results show that methylcobalamin inhibits the proliferation of malignant cells in culture and in vivo and propose the possibility of methylcobalamin as a candidate of potentially useful agents for the treatment for some malignant tumors.

Topics: Androgens; Animals; Breast Neoplasms; Cell Division; Dose-Response Relationship, Drug; Estrogens; Female; Homocysteine; Humans; Leydig Cell Tumor; Male; Mammary Neoplasms, Animal; Methionine; Mice; Neoplasm Transplantation; Neoplasms, Hormone-Dependent; Testicular Neoplasms; Tumor Cells, Cultured; Vitamin B 12