Showing papers by "Charles Huggins published in 1975"

Formation of bone marrow in fibroblast-transformation ossicles

Abstract: The genesis of hemopoietic bone marrow was studied in matrix-induced transformation plaques and ossicles in subcutaneous spaces of thorax and abdomen of rat. With the advent of blood vessels in the plaque on day 9, there began a rapid and radical conglomerate shift, cartilaginous to osseous, which was nearly total in 72 hr. Incorporation of 59-Fe into heme provided a sensitive quantitative assay for hemopoiesis. On day 12 the first colonies of hemopoietic cells were observed. These developed adjacent to cavernous sinuses which had formed to fill the void left by chondrolysis. Total occupation of the ossicle with hemopoietic marrow was found on days 23-28. The thoracic region was favorable for the formation of hemopoietic marrow, whereas lower abdominal sites were disadvantageous.

Influence of Prolactin on Carcinogen-induced Leukemogenesis in Long-Evans Rats

Abstract: Hypophysectomy of rats bearing 7,12-dimethylbenzanthracene-induced leukemia has been reported to result in a prompt and persistent regression of the leukemia. The purpose of this study was to determine whether or not marked alterations in prolactin secretion would influence this neoplastic process. To determine this, immature male and female Long-Evans rats were divided into three groups: Group 1, controls; Group 2, pituitary grafted (hyperprolactinemia); and Group 3, 2-bromo-α-ergocryptine-treated (hypoprolactinemia). Two weeks after the initial treatment and at 2-week intervals thereafter (6 total), each rat was given a single intragastric intubation of 7,12-dimethylbenzanthracene (10 mg/rat). Two months after the initial carcinogen treatment and at 2- to 3-week intervals thereafter, all rats had liver biopsies for the identification of leukemia. Results clearly show that despite nearly 10-fold difference in mean serum prolactin levels in the three groups of female rats and nearly a 20-fold difference in the level of this hormone in male rats, no significant differences in the magnitude of this leukemogenic process could be detected. Thus, striking changes in prolactin secretion do not appear to influence significantly this leukemogenic process.