Search PubMed⌕ Search

Biomedical subjects

B R Rao

Publications and source records attributed to B R Rao.

At least 127 records · Page 7Linked to original sources
PubMed1978

S-phase fractions of breast carcinomas. Relationships to morphology, estrogen and progesterone receptors, and early recurrence.

Analysis of the S-phase fractions (SPF) measured by in vitro thymidine labeling, morphological appearances, and estrogen receptor (ER) assays of primary invasive breast carcinomas demonstrated several interrelationships. Lobular, mucinous, tubular, and adenocystic carcinomas consistently had low SPF and were usually positive for ER. The same was true for the carcinomas of no special histologic type [the not otherwise specified (NOS) group of E. R. Fisher including "infiltrating ductal" and undifferentiated carcinomas] with minimal anaplasia. Medullary, atypical medullary, and morphologically unclassifiable carcinomas with marked nuclear anaplasia nearly always had high SPF and were usually negative for ER. High SPF was associated with advanced stages of carcinoma initially or with early recurrence following mastectomy.

Anaplasia↗
PubMed1977

Progesterone receptor in cystosarcoma phyllodes.

A specific receptor for progesterone has been found in a cystosarcoma phyllodes, as determined by charcoal adsorption and sucrose gradient analysis. Similar assays for estrogen receptors were negative. The tumor consisted almost entirely of stroma that contained the progesterone receptors. The epidemiology and natural history of cystosarcoma do not strongly support the hypothesis that it is controlled by female sex hormones, but the presence of the progesterone receptors suggests that some cystosarcomas are hormonally regulated, and thus may be responsive to therapeutic hormonal manipulation.

Aged↗
PubMed1977

Low incidence of estrogen receptor in breast carcinomas with rapid rates of cellular replication.

The results of assay for estrogen receptor (ER) in the tumor cytosol and thymidine labeling indices (TLI) of 63 primary invasive carcinomas of the breast were analyzed. The ER assay was performed by using dextran-charcoal to adsorb unbound tritiated estradiol-17beta (E2) in cytosol. The TLI was measured as the number per hundred of neoplastic cell nuclei labeled by tritiated thymidine. A significant association between low TLI and presence of ER was found. Wereas all 19 tumors with TLI less than 2.5 contained ER in the primary lesion or in axillary metastases and ER was found in 25 of 30 tumors with TLI between 2.5 and 10, only 4 of 14 tumors with TLI greater 10 contained ER (p less than 0.001). TLI and saturable binding of E2 were significantly negatively correlated (r=-0.436,P. less than 0.001). It is concluded that dedifferentiation in breast carcinomas is associated with both high TLI and absence of ER, and suggested that the carcinomas with the most rapid proliferative rates will include the highest proportion of tumors unresponsive to hormonal therapy.

Adult↗
PubMedDate not supplied

Effect of the insulin degradation inhibitors bacitracin and chloroquine on insulin binding data to H35 rat hepatoma cells.

The influence of correction for internalization and of inhibition degradation by the use of bacitracin or chloroquine on the insulin binding data of H35 rat hepatoma cells has been assessed. Internalized insulin represented about 50% of total cell bound insulin at tracer concentration and is not affected by bacitracin or chloroquine. The use of the insulin degradation inhibitors bacitracin and chloroquine resulted in Scatchard plots that were strikingly less curvilinear than control cells (as indicated by a decreased K1/K2 ratio (p less than 0.001) and Ke/Kf ratio (p less than 0.01)). In the two site model there was a significant increase in the number of high affinity binding sites concomitant with a significant decrease in the high affinity association constant; there was also a significant decrease in the number of the low affinity binding sites. The total number of binding sites did not change. For the negative cooperativity model the use of each drug resulted in a significant increase in the affinity constant of the filled site. These results indicate that insulin degradation induces negative cooperativity and that the results are inconsistent with the two site model.

Animals↗