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Biomedical subjects

B R Rao

Publications and source records attributed to B R Rao.

At least 91 records · Page 5Linked to original sources
PubMed1984

Estrogen positive feedback on LH secretion in transsexuality.

In order to test the hypothesis whether there is variation in hormonal levels or response to hormonal manipulation that could permit a distinction between heterosexuals and transsexuals, we designed the following protocol: Six male-to-female (m-to-f) transsexuals, six heterosexual control females and six female-to-male (f-to-m) transsexuals were given estradiol benzoate (E2B) (4.5 micrograms/kg/12 hr) for five days. In the female population, E2B treatment was initiated on day 5 of the menstrual cycle. In all the subjects blood luteinizing hormone (LH) and follicle stimulating hormone (FSH), estradiol-17 beta (E2) and testosterone (T) levels were measured twice daily. Additionally, LH and FSH responses to LHRH (100 micrograms iv) stimulation prior to and on day 5 of the E2B treatment were evaluated. In the m-to-f transsexuals, T levels decreased sharply and progressively during estrogen treatment, along with a fall in LH and FSH levels. The magnitude of the LH and FSH responses to LHRH stimulation also decreased following estrogen administration. In the heterosexual female controls and in the f-to-m transsexuals, estrogen administration increased LH levels to a minimum of 100% above initial values from day 3 onwards. Interestingly, the magnitude of the LH increase in the f-to-m transsexuals was greater than that of the heterosexual female controls. In both groups, LHRH stimulation resulted in a greater LH response compared to that prior to estrogen treatment. Our present observations, based on blood hormonal levels and responses to hormonal manipulations do not permit a distinction between heterosexual females and f-to-m transsexuals. There was no convincing evidence for the existence of a positive estrogen feedback on LH secretion in m-to-f transsexuals. These results contradict some of the reported hypotheses concerning hormonal alterations in these individuals.

Adolescent↗
PubMed1983

Cardiac gallium citrate concentration.

Cardiac accumulation of 67Ga was noted in a 45 year old black female with a history of fever and shortness of breath. Cardiac 67Ga uptake has been uncommonly cited and we report such a finding in a case of Cox sackie B viral pericarditis.

Coxsackievirus Infections↗
PubMed1983

Present concept of the relevance of steroid receptors for prostatic cancer.

Suitable assays for nuclear androgen-receptors in human prostatic cancer tissue have been presented. Correlations between NAR-content and response to hormonal therapy are demonstrated. The methods are time consuming and require expensive equipment as well as experience. Individual laboratory standards seem to determine response rates. The earlier methodological difficulties are replaced by a new set of problems for which as yet no single solution is available. As there is a tendency to use aspiration cytology more and more for diagnosis as well as follow-up of prostatic cancer, a cytochemical method would be extremely valuable. Research in that direction should be pursued.

Cell Nucleus↗
PubMed1983

Distribution and natural history of stress fractures in U.S. Marine recruits.

In a prospective study of stress injuries of the lower extremities of U.S. Marine recruits, we derived a frequency distribution of stress fractures. The most frequently fractured bone was the tibia (73%), while the single most common site was the posterior calcaneal tuberosity (21%). The natural history of stress fractures by scintigraphy and radiography has been outlined, showing the evolutionary changes on either study as a universal progression independent of injury site or type of stress. An identical spectrum of changes should be present within any group undergoing intense new exercise. The frequency distribution of stress fractures should be a function of differing forms and intensities of exercise, therefore, our figures should not be applied to other groups. We used the presence of a scintigraphic abnormality at a symptomatic site as the criterion for diagnosis of stress fracture. Since the distribution of skeletal radiotracer uptake is directly dependent on local metabolic activity, it is expected that a focal alteration in bone metabolism will result in a scintigram approaching 100% sensitivity for the abnormality (9). In the proper clinical setting, the specificity should approximate this figure; however, a focal, nonstress-related bone abnormality which has not manifested any radiographic change, such as early osteomyelitis, could result in a false-positive examination. Specificity cannot, therefore, be accurately determined without an actual determination of the pathologic changes within the bone, necessarily involving biopsy. In summary, we believe that we have established bone scintigraphy as an early and accurate means for the detection of lower extremity stress fractures, even in the absence of radiographic findings (6). We feel that a focally abnormal scintigram, in the proper clinical setting, establishes the diagnosis of stress fracture, with radiography to be performed at the time of initial work-up only to rule out a non-stress injury (such as complete fracture, fibrous dysplasia, osteomyelitis, primary bone tumor).

Adult↗
PubMed1982

Estimating the proportion of mutagenic compounds in environmental samples.

A method for estimating the proportion of mutagens in a sample of N compounds is developed. For this procedure to be applicable, there must be a statistically significant correlation between the number of mutagens in the sample and the sample size N. Sample size is treated as a random variable. A sequential sampling scheme is considered. In the first stage, compounds are identified and classified as mutagens, nonmutagens, or untested, as reported in the literature. In the second stage, all untested compounds are tested for mutagenicity. Since data of this type are not generally available, estimates of the proportions of compounds tested (p), tested and mutagenic (p1), and untested but mutagenic (p2) are developed from existing complications. It is shown that there is a high, statistically significant correlation between the total number of mutagens in a sample and the sample size N. The proportion of mutagens in a sample for various values of p, p1, and p2 is tabulated.

Environmental Pollutants↗
PubMed1981

Most cystosarcoma phyllodes and fibroadenomas have progesterone receptor but lack estrogen receptor: stromal localization of progesterone receptor.

Biochemical study of fibroepithelial tumors of the female breast showed presence of progesterone receptor (PgR) in all five cystosarcoma phyllodes (two malignant, three benign), and in 11 of 13 fibroadenomas tested. Estrogen receptor (ER) was detected in only one of five cystosarcomas and 2 of 13 fibroadenomas. The relative volumes occupied by epithelium and stroma in each tumor were measured from histologic sections. The results were consistent with presence of PgR in the stroma and ER in the epithelium. Different types of cystosarcoma (benign and malignant) and different types of fibroadenomas (intracanalicular, pericanalicular, and mixed) did not differ significantly in content of PgR, and mean levels of PgR in cystosarcoma were comparable with those in fibroadenomas. The presence of PgR in cystosarcomas suggests that progestational therapy, and possibly other forms of hormonal therapy, should be tested in the treatment of advanced, malignant cystosarcoma phyllodes.

Adenofibroma↗
PubMed1981

Congenital intrathoracic kidney: a 5-year radionuclide follow-up.

Congenital intrathoracic kidney (CIK) is an exceedingly rare anomaly. IN a study of 15,919 autopsies of children by Campbell [1], only one CIK was noted. Less than 50 cases have been reported so far in English literature [3]. Most of the CIK are asymptomatic normal organs which require no medical or surgical treatment. We have had the opportunity of applying scintiphotographic techniques exclusively to follow up a 9 1/2-month-old infant with CIK for 5 years.

Follow-Up Studies↗
PubMed1981

Congenital intrathoracic kidney.

An intrathoracic kidney, although rare, should be considered in a child with a mass at the base of the lung on a chest radiograph. Excretory urography is diagnostic and may eliminate the need for further extensive investigation and operation.

Chlorothiazide↗
PubMed1980

A fluorescent probe for rapid detection of estrogen receptors.

Fluorescein conjugates to estradiol-17 beta by the sixth carbon (6-FE) and to estrone by the 17th carbon (17-FE) were used to detect estrogen receptors (ERs) in breast cancer tissue sections and in cultured cell lines (human mammary carcinoma MCF-7 and Copenhagen rat prostatic tumor R3327-AT). 17-FE was found to interact with ERs better than 6-FE by biochemical and histochemical techniques. Thin layer chromatography analysis of ethanolic extracts of 17-FE incorporated in tissues and cultured cells showed that over 95% of 17-FE was not metabolized. We concluded that the fluorescence observed in tissue sections and cultured cells was due to 17-FE and not to fluorescein dissociated from the conjugate. Analysis of 65 human breast cancer showed that 74% of the cases were positive for specific 17-FE uptake and 26% were negative. The fluorescence was consistently brighter in the ductal and glandular epithelial cells than in the stroma. specific 17-FE uptake in the nucleoli was observed in MCF-7 and in R3327-AT tumor cells in in vitro cultures, suggesting that these nucleolar estrogen receptors may play a key role in the mechanism of estrogen action. Problems of fluorescence quantitation in tissue sections and cells are discussed.

Animals↗