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Biomedical subjects

R Y Kirdani

Publications and source records attributed to R Y Kirdani.

At least 19 recordsLinked to original sources
PubMed1987

The possibility of aromatization of androgen in human prostate.

Aromatase in human prostate tissue was determined in homogenized human prostate (three BPH and two normal specimens) incubated with [1-beta-3H]androstenedione (radiometric method) or [1,2,6,7-3H]androstenedione (estrogen production analysis method) in the presence of NADPH. Using the former procedure, significant amounts of 3H2O, resulting from the release of 3H at the C-1 position during aromatization, were measured and these increased with incubation time and amount of tissue, whereas the amount of estrone and estradiol-17 beta resulting from the latter method and calculated from the 3H/14C ratio in preparations of purified crystal was very small. The preliminary results, which suggest that an androgen aromatase system exists in the human prostate, point to the need to further investigate the identity and properties of the metabolic products resulting from the conversion of androgen to estrogens and other metabolites.

Androstenedione↗
PubMed1986

Effects of busulfan on the DNA of HL-60 cells as a drug sensitivity assay.

We evaluated the formation of DNA-DNA cross links by busulfan as an assay for determining the sensitivity of cells to the drug. HL-60 cells were incubated with busulfan and the effects of the drug on cell growth were compared with the effects of the drug on the alkaline elution pattern of the DNA. While incubation with 100 micrograms/ml for 1 h inhibited cell growth by 50%, drug concentrations of up to 500 micrograms/ml had no effect on the elution pattern of the DNA.

Busulfan↗
PubMed1985

A comparison of estrogen and androgen receptor levels in human prostatic tissue from patients with non-metastatic and metastatic carcinoma and benign prostatic hyperplasia.

Estrogen receptors (ER, N = 72) and androgen receptors (AR, N = 33) were determined by high pressure liquid chromatography (HPLC) in 72 human prostatic tissues obtained at prostatectomy, and exploratory statistical analyses of the resulting data were performed. To facilitate use of these data as well as other pertinent information from the patient charts, a program for a comparatively large data base was implemented on a Wang minicomputer. The median values of cytosolic AR in the four cancer stages examined were statistically different from each other (P = 0.01), with AR increasing from stages A through D. Even though ER differences between the four stages were not significant (P = 0.13), there was a trend, in the data examined, for median ER values to decrease with stages B through D. On the other hand, median BPH values for both ER and AR were found to lie mid-scale compared with the respective cancer stages, leading to the conclusion that receptor measurements probably cannot distinguish between CA and BPH in human prostatic tissue, at least as measured by competitive binding techniques.

Binding, Competitive↗
PubMed1984

Correlation of estrogen and androgen receptor status in prostatic disease measured by high pressure liquid chromatography.

To further characterize human prostatic estrogen receptors (ER) determined by high pressure liquid chromatography (HPLC), we checked our procedure by which we nullify estrogen binders (including testosterone binding globulin, TeBG) other than ER by preincubation of cytosols with dihydrotestosterone (DHT). We also showed that the ER exhibited ligand specificity and that ER is present in BPH nuclear extract at 10-fold its concentration in the corresponding cytosols. Of seven prostates with localized cancer determined preoperatively, only 3 showed localization; ER concentration in the cancer parts was lower than in the corresponding surrounding BPH. A total of 22 specimens were evaluated for ER and androgen receptors (AR). Statistically, AR had higher values than ER but there was no correlation between the corresponding AR and ER for each tissue.

Adenocarcinoma↗
PubMed1982

A micromethod for the measurement of estrogen receptors using high pressure liquid chromatography.

Adequate sample size has been one of the difficulties encountered in routine determination of estrogen receptors in prostatic disease. The recent commercial availability of protein analysis columns for use with high pressure liquid chromatography (HPLC) equipment has made the achievement of a considerable reduction in sample size feasible. We present a method for determination of ER which includes the use of 16 alpha-125-iodo-estradiol ( [125I]-E2) of 1600 Ci/mmol specific activity, the use of G-25 column chromatography, followed by fractionation by HPLC and finally relation of the fmol specifically bound to mg protein measured in the HPLC peak. Data obtained upon determination of ER in the immature rat uterine model system are given to show consistent recoveries, ligand specificity, saturability, inhibition, and commonly accepted KD and n values for this system. Also, in a pilot study on 13 samples from human prostatectomies, the utility of the HPLC technique for ER measurement in that tissue using single point analysis is demonstrated. For comparison, all receptor determinations reported were also made using conventional methods.

Animals↗
PubMed1982

Estrogen receptors and clinical correlations with human prostatic disease.

Measurement of estrogen binding in human prostate using high-pressure liquid chromatography (HPLC) revealed the presence of cytosolic estrogen receptors (ER) both in benign prostatic hyperplasia (BPH) and adenocarcinoma. Receptor concentrations correlated with several histopathologic features in the specimens analyzed. Estrogen receptor levels generally were higher in BPH than in cancer specimens although there was a subgroup of patients with poorly differentiated carcinoma with levels higher than those of BPH, HPLC can be used for measuring ER in 50 microliters of cytosol, and thus needle biopsy specimens will be analyzed routinely for ER with this micromethod.

Adenocarcinoma↗
PubMed1981

Estramustine binding in rat, baboon and human prostate measured by high pressure liquid chromatography.

High pressure liquid chromatography (HPLC) was used to determine 3H-estramustine (estradiol-17 beta 3N-bis-[2-chlorethyl] carbamate), 3H-17 beta-hydroxy-5 alpha-androstan-3-one (3H-dihydrotestosterone or 3H-DHT), 3H-estradiol-17 beta (3H-E2) and 3H-3 beta-hydroxy-5-pregnen-20-one (3H-pregnenolone) binding in 50(2) microliter of cytosol utilizing a column which separates proteins in the molecular weight range of 2,000 to 70,000 daltons. The rat prostate contains a protein in considerable concentration and with the highest affinity for estramustine (375,000 dpm 3H-estramustine per mg. cytosol protein) among the substances tested. Operationally, we have named this protein "estramustine binding protein" (EBP), though it is very likely similar to other previously described prostatic proteins (e.g., alpha-protein, prostatein, prostatic binding protein). The sensitivity of the HPLC method disclosed EBP-like proteins, but in much lesser concentrations, in some of the other tissues tested. The concentration of these proteins in the human and baboon prostates was much lower (average for the baboon cranial lobe 4800 dpm/mg cytosol protein, with a somewhat higher value for the caudal lobe) than that in the rat gland. The amount of the EBP-like protein was higher in prostatic cancer than in that of benign prostatic hypertrophy (BPH) (range 9350--25,900 vs. 2200--18,900 dpm/mg cytosol protein). In the human, the highest value was found in one normal prostate tested (106,000 dpm/mg cytosol protein).

Animals↗
PubMed1981

Effect of LS 1727, a nitrosocarbamate of 19-nortestosterone, on the R-3327 rat prostatic adenocarcinoma.

LS 1727, a nitrosocarbamate of 19-nortestosterone did not affect the growth of the androgen-dependent R-3327 rat prostate adenocarcinoma. Such treatment markedly increased the weight of the ventral prostate and reduced body weight. The androgenic character of LS 1727 was demonstrated in an experiment in which LS 1727 was found to reduce the uptake of tritiated dihydrotestosterone in both the ventral prostate and the tumors. The androgenic growth-stimulating action of LS 1727 on the tumors may have counteracted the cytostatic, growth-inhibitory action of the compound.

Adenocarcinoma↗
PubMed1980

Effects of diethylstilbestrol and estramustine phosphate on serum sex hormone binding globulin and testosterone levels in prostate cancer patients.

Serum testosterone-estradiol binding globulin and total testosterone were measured in 2 groups of male controls (less than 50 and more than 65 years old) and in 7 groups of prostatic cancer patients treated with various endocrine manipulation procedures, including orchiectomy, and estramustine phosphate and diethylstibestrol therapy. There were 133 individuals studied. Total serum testosterone levels were significantly higher in the younger versus the older control group and testosterone-estradiol binding globulin levels were significantly higher in the older men. Whereas orchiectomy reduced serum testosterone to low concentrations (72 plus or minus 11 ng. per 100 ml.) testosterone-estradiol binding globulin levels were not altered. In contrast, estramustine phosphate and diethylstilbestrol therapy, when administered to intact or castrated patients, resulted in depressed testosterone and markedly elevated testosterone-estradiol binding globulin serum levels, particularly in those patients receiving estramustine phosphate (less than 35 ng. per 100 ml. and more than 6 micrograms per 100 ml., respectively). These studies led to the conclusion that diethylstilbestrol or estramustine phosphate therapy is significantly more effective than orchiectomy in eliciting a concomitant elevation of testosterone-estradiol binding globulin and a depression of total testosterone. Even though free serum testosterone was not measured in the present study the law of mass action would indicate that in those patients with high testosterone-estradiol binding globulin (more than 5 microgram. per 100 ml.) and low total testosterone levels (less than 80 ng. per 100 ml.) the availability of biologically active (unbound steroid) testosterone would be negligible.

Adult↗
PubMed1980

Measurements of prolactin and androgens in patients with prostatic diseases.

Testosterone (T), dihydrostestosterone (DHT) and prolactin (HPr) levels were determined in normal males and females, in patients with benign prostatic hypertrophy (BPH) and in clinically stable patients with prostatic carcinoma (CAP), intact and orchiectomized. CAP patients were either untreated or on different modalities of therapy. The HPr levels were higher in prostatic cancer patients, in BPH patients, and in subjects on estrogen therapy. No significant differences were found between controls or patients treated with 5-Fu plus cytoxan. The T and DHT levels were decreased in all noncontrol subjects. The levels of DHT in intact, untreated CAP patients or those receiving 5-FU plus cytoxan were significantly higher than in BPH patients. Based on these observations, it appears that HPr could be involved with T and DHT in a feedback control role, especially in BPH. The alterations in these hormone levels in CAP treated or untreated patients are in marked contrast and must be evaluated further.

Adult↗
PubMed1979

Steroid hormone receptors in the prostate.

Specific receptors for dihydrotestosterone and estradiol-17-beta have been identified in cytosols of the human and baboon prostate. Binding of radioactive estradiol-17-beta to the 0.4 M potassium chloride extractable component of human prostate nuclei also was demonstrated. Cyproterone acetate and diethylstilbestrol, agents of known high affinity for dihydrotestosterone and estradiol-17-beta receptors, respectively, did not bind significantly to sex hormone binding globulin and, therefore, were useful as competitors in distinguishing binding of dihydrotestosterone and estradiol-17-beta to sex hormone binding globulin and to their specific receptors. Displacement of [3H]-estradiol-17-beta binding by diethylstilbestrol in cytosols of 11 needle biopsy specimens (mean equals 16.8 mg.) from prostatic cancer patients was analyzed. These preliminary data indicated a trend towards greater competition by diethylstilbestrol for high affinity binding sites in differentiated tumor specimens from men who were not receiving estrogen therapy. Objective and subjective responses to hormone therapy were recorded in these patients, whereas the disease in those men with low displacement assay values progressed.

Aged↗
PubMed1979

Androgen binding in the baboon prostate.

Androgen receptors were identified and partly characterized in cytosols of the caudal and cranial prostatic lobes of a 24-hr castrate baboon. Binding of cyproterone acetate (CA) to testosterone-binding globulin (TeBG) in baboon serum was negligible and therefore was an appropriate unlabeled competitor for distinguishing high-affinity binding of tritiated dihydrotestosterone (3H-DHT) to serum contaminants and receptors in cytosol preparations when multiple-point saturation analyses and removal of free steroid by charcoal adsorption were used. Specificity of androgen binding was demonstrated by the inability of diethylstilbestrol, a synthetic estrogen known to have low binding affinity for TeBG, to displace 3H-DHT from the receptor protein. The number of high-affinity binding sites and the dissociation constant of the androgen receptor calculated for the caudal lobe were 102 fmoles/mg cytosol protein and 4.0 X 10(-9) M, respectively; corresponding values for the cranial lobe were 49 fmoles and 1.3 X 10(-9) M.

Animals↗