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M Carmel

Publications and source records attributed to M Carmel.

36 records · Page 2Linked to original sources
PubMed1988

Application of octadecylsilyl-silica in purification studies related to the nontransformed rat ventral prostate androgen receptor.

We investigated the application of octadecylsilyl (ODS)-silica in studies related to characterization and purification of the nontransformed rat ventral prostate androgen receptor. The results indicated that ODS-silica successfully separates the free [3H]R1881 from the labeled [3H]R1881 transformed (4-5S) and nontransformed (8-9S) rat ventral prostate androgen receptors. Partial purification of the 8-9S receptor form was performed by the fractionation of rat cytosol using cartridges of the ODS-silica and fast-flow-rate phosphocellulose chromatography. Further purification was accomplished by differential chromatography (DEAE-cellulose and slow-flow-rate phosphocellulose chromatography). This partially purified 8-9S receptor, when analyzed on a gel permeation high-performance liquid chromatography column, resulted in a three-peak pattern of UV absorbance. One of these peaks corresponded to a 59-kD non[3H]R1881-binding protein and the remaining two corresponded to 270-kD and 190-kD[3H]R1881-binding proteins. These results demonstrate the usefulness of ODS-silica in androgen receptor studies. The association of a 59-kD nonsteroid binding protein with the nontransformed rat ventral prostate androgen receptor is discussed.

Animals↗
PubMed1988

Purification and characterization of the untransformed androgen receptor in rat prostate.

The isolation and characterization of the untransformed form of androgen receptors has not yet been successful, owing to their inherent lability as well as to their ready proteolysis. In this study, we have stabilized rat prostate androgen receptors by sodium molybdate and by rapid filtration on phosphocellulose. Proteases were inhibited by bacitracin, aprotinin, leupeptin and PMSF. Under these conditions the untransformed complex was purified approx 3000-fold, corresponding to 18% yield, by differential chromatography on DEAE cellulose and phosphocellulose gels. The partially purified receptor has the same ionic characteristics as the original untransformed receptor of crude cytosol; in addition, it possesses a Stokes' radius of 75 A, as determined by Sephacryl S-300 gel filtration, a sedimentation coefficient of 8.8S, a calculated molecular weight of 275 kDa and a friction coefficient of 1.6. The [3H]R1881 receptor complex was specific to androgens since unlabelled R1881 and dihydrotestosterone were able to completely displace bound [3H]R1881, whereas estradiol, cortisol, and triamcinolone acetonide did not compete. The purified complex was a multimer dissociable by 0.6 M KCl, resulting in a form migrating in the 4S area on sucrose density gradient. After treatment with 0.5% formaldehyde, three forms were obtained, migrating in the areas of 8-9, 5-6 and 3-4S respectively, of a sucrose density gradient containing 0.6 M KCl. This is the first step towards the purification to homogeneity of the untransformed androgen receptor.

Animals↗
PubMed1987

Application of high-performance liquid chromatofocusing to the study of prostatic androgen receptors. Effect of stabilizing agents on the heterogeneity of receptor structure.

Cytosolic androgen receptors from normal rat prostate were analyzed by high-performance liquid chromatofocusing. Two ion-exchange columns, AX-300 and AX-500, and two equilibration systems, Tris-HCl and imidazole-HCl, were used. pH gradients ranged between 8.3 and 3.5 for Tris-HCl and from 7.7 to 3.5 for imidazole-HCl. In the absence of sodium molybdate and inhibitors of proteolytic enzyme, six specific radioactive fractions (pH: 7.9, 7.7, 7.0, 5.1, 4.7 and 4.4) were eluted from AX-300 equilibrated with Tris-HCl in a ratio of 28:20:52 for acidic, intermediary and basic forms, respectively; similar results were obtained with AX-500 although this column was less effective in resolving basic forms of the receptor. The buffering capacity of imidazole-HCl was lower than that of Tris-HCl, resulting in a steeper elution pH profile. The resolution between acidic and basic forms was thus diminished and only four specific radioactive fractions at pH 7.2, 7.1, 6.5 and 3.6, were observed on AX-500 in a ratio of 23:10:67 for acidic, intermediary and basic forms. In the presence of sodium molybdate, two acidic fractions were found with Tris-HCl at pH 4.3 and 4.7 (47%) on AX-300, whereas the radioactivity of fractions at pH 7.0 and 5.1 (32%) was considerably lowered and intermediary forms remained unchanged (21%). With imidazole-HCl on AX-500, the peak at pH 7.2 disappeared and the acidic form shifted from pH 3.6 to 4.3. In the presence of inhibitors of proteolytic enzyme and sodium molybdate, specifically bound radioactivity was found mostly in a broad acidic fraction (75%) at pH 4.5 on columns equilibrated with Tris-HCl; radioactivity at pH 7.6 disappeared completely but a small amount (15%) remained at pH 7.9. In imidazole-HCl, a main radioactive fraction was eluted at pH 7.1 and two other fractions were collected at pH 6.8 and 4.3 respectively. In conclusion, multiple forms of the rat prostate androgen receptor were evinced by high-performance liquid chromatofocusing. Tris-HCl proved to be a more efficient equilibration system than imidazole-HCl for the resolution of rat prostate cytosolic binding proteins. Under the experimental conditions used, sodium molybdate and inhibitors of proteolytic enzyme greatly favored the acidic form to the detriment of the intermediary and basic entities.

Animals↗
PubMed1987

Tamoxifen citrate therapy in male infertility.

A prospective, randomized, double-blind study with crossover, using tamoxifen (TAM) (Nolvadex, ici Pharma, Missisauga, Canada) 20 mg/day and placebo (p) for 6 months each, was conducted in 16 infertile men with idiopathic oligozoospermia. Baseline sperm count was 17.092 +/- 3.09 (10(6)/ml). Hormonal profile was performed and included follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), testosterone (T), prolactin (PRL), thyroid-stimulating hormone (TSH), and luteinizing hormone-releasing hormone (LH-RH) stimulation tests. The sperm analysis and hormonal profile were repeated at 6 and 12 months of the study. A sperm penetration assay (SPA) was performed on zona-free hamster egg. Compared with the placebo group, the TAM group showed a significant increase in plasma FSH, LH, E2, and T levels (P less than 0.001), but not in PRL and TSH levels. However, LH-RH stimulation tests and SPA were found to be comparable in the two treatment groups, and there was no significant effect on sperm analysis. Tamoxifen appeared to be no more effective than the placebo in the treatment of idiopathic oligozoospermia.

Adult↗
PubMed1986

Characterization of androgen receptors in normal and malignant human prostatic tissues.

The aim of this work was to study the physico-chemical characteristics of androgen receptors of normal and malignant human prostatic tissues. Association (k+1) and dissociation (k-1) rate constants and sedimentation profiles on sucrose density gradients were determined on [3H]androgen receptor complexes. In the presence of 20 mM sodium molybdate, no significant difference in k+1 and k-1 values could be found between cytosolic receptor preparations from normal and malignant specimens. The values obtained for k+1 (mean +/- SD) were 5 +/- 2 X 10(6)M-1 min-1 (N = 3) and 5 +/- 2 X 10(6)M-1 (N = 5); k-1 values of 23 +/- 4 X 10(-4) min-1 (N = 4) and 25 +/- 3 X 10(-4) min-1 (N = 5) were obtained for normal and malignant tissues respectively. Similar Nmax values were also obtained for normal [(mean +/- SD) 26 +/- 10 fmol/mg cytosolic protein (N = 5)] and malignant [20 +/- 9 fmol/mg protein (N = 7)] tissues. A statistically significant difference was found however, between k-1 values measured on [3H]androgen receptor complexes of nuclear extracts; values of 15 +/- 3 X 10(-4) min-1 (N = 4) and 9 +/- 1 X 10(-4) min-1 (N = 6) were found for normal and malignant tissue preparations respectively. This was also accompanied by a higher level of androgen receptors in nuclear extracts of malignant [Nmax, 308 +/- 171 fmol/g of tissue (N = 8)] compared to normal [Nmax, 68 +/- 11 fmol/g of tissue (N = 5)] tissues. The cytosolic [3H]androgen receptor complexes prepared from normal tissues sedimented mainly in the 8-9S area on sucrose density gradient whereas those from malignant tissues sedimented 50% in the 8-9S area and 50% in the 4S area. In conclusion, in this study, we found a different sedimentation profile of androgen-receptor complexes from the cytosol of prostatic cancers compared to normal as well as a diminution of their dissociation rate constant in nuclei.

Cell Nucleus↗
PubMed1986

Hindgut dysgenesis as a cause of constipation with delayed colonic transit.

In a patient complaining of constipation since birth, delayed transit time in the ascending colon was related to a congenital malformation of the hindgut, different from Hirschsprung's disease. This was associated with absence of the left lobe of the liver. There was no propagating electrical muscular activity in the distal bowel.

Adult↗
PubMed1985

Creatine phosphokinase isoenzymes in human prostatic tissues: a comparison between benign hyperplasia and adenocarcinoma.

The objective of this study was to determine the distribution of creatine phosphokinase (CPK) into its three isoenzymes, MM, MB, and BB, in human prostatic tissue, in patients with benign hyperplasia (BPH) and adenocarcinoma. Specimens were obtained from 23 patients with adenocarcinoma of the prostate and 25 patients with benign hyperplasia. We also had the opportunity to analyze the CPK content in two normal prostates, the first from a 16 1/2-year-old boy and the second from a 9 1/2-year-old child. Our results showed prostate tissue to contain almost exclusively the BB isoenzyme with traces of the MB and MM dimers in both cancer and BPH as well as the specimen of normal prostate from the 16 1/2-year-old boy. As for the 9 1/2-year-old child, we found the following distribution: 39% MM, 21% MB, and 40% BB dimer. A comparison of the CPK-BB content in benign hyperplasia and adenocarcinoma revealed no significant difference between the two groups. Furthermore, we tried to correlate prostatic tissue CPK-BB levels with another possible tumor marker of the prostate, prostatic acid phosphatase (PAP) measured in the cytosol. No correlation was found between these two markers. We also studied the relationship of CPK-BB and PAP content in prostatic tissue to nuclear and cytosolic androgen receptor content in human prostatic tissue. We found some correlation between CPK-BB and androgen cytosolic receptors as well as between PAP content and androgen cytosolic receptors in patients with benign hyperplasia. No such correlation was found in the group with adenocarcinoma. In conclusion, this study does not show that the measurement of CPK-BB in the prostatic tissue could be used as an index of tissue malignancy.

Acid Phosphatase↗
PubMed1983

Leiomyosarcoma of prostate.

Leiomyosarcoma of the prostate is a rare tumor with no established protocol of treatment in the literature. We report a case with peculiar clinical presentation and androgen receptor content supporting the origin of the tumor. The potential advantage of hormonal manipulation during progression of the disease is suggested.

Dihydrotestosterone↗
PubMed1983

Nuclear androgen receptors of human prostatic tissue--a quantitative histological study.

The objective of this study was to determine the nuclear dihydrotestosterone (DHT) nuclear receptors content in tissues of normal prostate, benign prostatic hypertrophy (BPH), and prostatic cancer. We also attempted to correlate this with the histological pattern of these tissues. Specimens were obtained from five normal subjects, 24 BPH, and 19 prostatic cancer patients. Nuclear receptors content was determined. All histological sections were reviewed by three independent pathologists. The criteria for the quantitative analysis were the degree of cellularity and the stromal content. The mean receptor content was not significantly different between neoplastic tissue (52.6 fmol/mg protein) and hyperplastic tissue (38.9 fmol/mg protein). The number of binding sites in normal prostatic tissue was 8.5 fmol/mg protein. The correlation between the degree of cellularity and DHT receptors showed no significant difference for both BPH, as well as prostatic cancer. Similar results were obtained when stromal content was compared.

Adenocarcinoma↗
PubMed1981

Condyloma acuminatum of bladder.

A patient with a condyloma acuminatum of the bladder is presented. This is a rare manifestation of the lesion. The salient features which characterize the lesion are described, and the differential diagnosis is discussed.

Aged↗
PubMedDate not supplied

Substance P and neurokinins as stimulants of the human isolated urinary bladder.

Neurokinins are active stimulants of the human isolated urinary bladder. In a preliminary study, performed on bladders taken from four donors, we attempted the characterization of neurokinin receptors. It was shown that neurokinin A is more active than neurokinin B and substance P. Neurokinin receptors selective agonists were also tested and it was found that the most active compound was the NK-A selective agonist, [Nle10]NKA 4-10: A substance P antagonist was able to reduce the effect of neurokinin A but its affinity was rather low. This suggests that the receptor mediating the contraction of the human urinary bladder to neurokinins is of the NK-A (NK2) type. The action of neurokinins on the human urinary bladder appears to be a direct one and mediated by specific receptors different from those of other agents. On the contrary, kinins were found to be active through a new mechanism which was not influenced by either anti-B1 or anti-B2 receptor antagonists.

Adult↗
PubMedDate not supplied

Development of a health risk appraisal for the elderly (HRA-E).

The purpose of this project is to develop a health risk appraisal for the elderly (HRA-E) and test its application in both medical and nonmedical settings. The HRA-E system consists of a questionnaire and software for computer-generation of personalized reports to participants, 55 years and older, and their physicians. Items in the questionnaire cover a comprehensive range of content domains relevant to health promotion in the elderly. The goal of the HRA-E system is to prevent functional decline. Samples of eligible subjects from the American Association of Retired Persons (AARP), a group practice, and a senior center were extended invitations to participate. Those responding affirmatively to the invitation were given a questionnaire and evaluation form. Each person who returned the questionnaire received his or her personal report and a second evaluation form. Four months after receiving their reports, respondents were questioned about behavior changes during the interim. Preliminary findings, based on 1895 respondents, indicate that nearly all participants found the questionnaire easy to complete and were pleased with its overall length. In addition, most participants read their reports, and many planned to take action, based on report recommendations. In the next phase of this project, the intent is to refine the questionnaire, extend the intervention protocols for longitudinal application, and evaluate its impact on health-related behaviors, medical care utilization, and functional decline.

Activities of Daily Living↗
PubMedDate not supplied

Characterization and partial purification of the 8-9S androgen receptor from benign prostatic hyperplasia tissues.

The present study reports a 3,800-fold purification of the 8-9S androgen-receptor complex from benign prostate hyperplasia (BPH) tissues using differential chromatography. In addition, the BPH androgen receptor complexes have been characterized using sucrose density gradient (SDG) ultracentrifugation, gel permeation, and anion exchange high performance liquid chromatography (HPLC). Results indicate that a) under nontransforming conditions, BPH cytosols contained both 8-9S (40-78%) and 4S (22-60%) androgen-receptor forms, b) apparent molecular weights of these androgen-receptor apparent molecular weights of these androgen-receptor complexes, as analyzed by gel permeation HPLC, were estimated to correspond at 270 kDa, and 90 kDa respectively, c) 8-9S androgen-receptor complexes were retained on an anion exchange HPLC column and could be eluted at 0.22 M KCl at a linear gradient, whereas 4S complexes were not retained on anion exchange columns under identical experimental conditions, d) 10X dilution of BPH cytosols containing only the 4S (0.6 M KCl) form and subsequent chromatography on anion exchange HPLC system was indicative of fragmentation (these fragments were retained on anion exchange columns and could be eluted by 0.33 M KCl on a linear gradient HPLC), and e) increased temperature (22 C) was permissive of proteolytic fragmentation (fragments were estimated to correspond at 30, 15, and 5 kDa). The results are discussed in relationship with the composition of the nontransformed androgen-receptor molecules.

Aged↗
PubMedDate not supplied

Sucrose density gradient and exchange high performance liquid chromatography characteristics of rat prostate androgen receptor forms.

In this study, we characterized rat prostate androgen receptor using sucrose density gradient ultracentrifugation, gel permeation and anion exchange high performance liquid chromatography (HPLC). Our results indicated that 1) androgen receptor complexes in rat prostate cytosols containing no KCl were of 8-9S form corresponding to 270kDa, and in cytosols containing 0.6M KCl were of 5-6S form corresponding to 90kDa; 2) 8-9S androgen receptor complexes were retained and could be eluted by 0.22M KCl in a linear gradient anion exchange HPLC; 3) Dilution (10X) of the 8-9S and of the 5-6S receptor complexes and subsequent chromatography on anion exchange columns was indicative of fragmentation. Fragments were of 3-4S form and were eluted by 0.33M KCl on anion exchange HPLC. Temperature (22 degrees C) was permissive of proteolysis generating a 30kDa androgen receptor fragment. These results are discussed in the context of the composition of non-transformed rat prostate androgen receptor.

Animals↗
PubMedDate not supplied

Characterization of androgen receptor by high performance liquid chromatography and sucrose density gradient ultracentrifugation in normal and malignant human prostatic tissues.

In the present study we have characterized androgen-receptor complexes of normal and malignant human prostate cytosols using sucrose density gradient centrifugation, gel permeation and anion exchange high performance liquid chromatography (HPLC). Our results indicated that: 1) malignant tissue cytosols differed from normal by the presence of a 4-5S androgen receptor form which accounted for 30% of total specific-binding of malignant tissue cytosols, 2) 8-9S androgen-receptor complexes in normal and malignant prostate cytosols were estimated as 270kDa by gel permeation HPLC, 3) 8-9S complexes were retained and could be eluted by 0.22M KCl on a linear gradient anion exchange HPLC, 4) 4-5S androgen-receptor complexes were estimated as 90kDa by gel permeation HPLC and were not retained on anion exchange HPLC in our experimental conditions, and 5) either 10X dilution of the 4-5S complexes and subsequent anion exchange HPLC, or anion exchange chromatography of 8-9S complexes at 22 degrees C were causing fragmentation of the androgen receptor molecule from normal and malignant tissues. These fragments had enhanced affinity for anion exchange columns. These results are discussed in relation to the composition of the nontransformed androgen receptor macromolecule.

Adult↗