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Biomedical subjects

E Steinberger

Publications and source records attributed to E Steinberger.

At least 73 records · Page 4Linked to original sources
PubMed1978

Relationship of varicocele to sperm output and fertility of male partners in infertile couples.

Both partners of 455 infertile couples seen consecutively were evaluated. When indicated the female partners were treated. Six semen specimens from each male subject were analyzed. A varicocele was diagnosed in 23.7 per cent of the men. More than 60 per cent of the men with a varicocele had sperm counts less than 40 million per ml., while 67 per cent without a varicocele had sperm counts more than 40 million per ml. The mean and total sperm counts of men with a varicocele were significantly lower than those without a varicocele. However, the pregnancy rates were not significantly different. The pregnancy rate was 46 per cent in couples whose male partners underwent a varicocelectomy, not significantly different from the pregnancy rate achieved in couples when the varicoceles were not corrected surgically (51 per cent). Varicocelectomy resulted in improvement in sperm count only when preoperative counts were more than 10 million per ml. Pregnancy rates for couples in which a varicocelectomy did or did not result in improvement in sperm count or motility were identical (45.1 and 45.5 per cent, respectively). These findings suggest that in male partners of infertile couples the presence of a varicocele is associated with compromised semen quality but not with diminished fertility when the female partners are treated. This observation emphasizes the importance of considering infertility as a problem of a couple, rather than a specific disorder of one of the partners.

Cell Count↗
PubMed1978

Inhibition of de novo synthesis of FSH by the Sertoli cell factor (SCF).

The effects of SCF, a substance produced by isolated rat Sertoli cells in culture, on the synthesis of FSH and LH were studied in vitro. Anterior pituitaries from adult male rats were organ-cultured 24-48h in the presence and absence of SCF in the culture medium. The incorporation of 3H-leucine into FSH and LH was determined following 6h incubation with this labelled precursor and immunoprecipitation with specific FSH or LH antibodies. Total FSH and LH were measured by radioimmunoassay. The results indicate that SCF can selectively reduce the incorporation of 3H-leucine into immunoprecipitable FSH without decreasing the incorporation into LH.

Animals↗
PubMed1978

Suggestion of abnormal testicular steroidogenesis in some oligospermic men.

Androgen biosynthesis in the testis may be analyzed in some detail by means of techniques of in vitro incubation of small testicular biopsy specimens with suitable radiolabelled precursors. Sixty-six tissue specimens from 33 patients who underwent bilateral testicular biopsies because of infertility were incubated in vitro with [3H]pregnenolone in order to investigate the possibility of abnormalities in their steroid biosynthetic activity. As a normal control, testicular tissue obtained by testicular biopsy from a young normal volunteer was used. The distribution of metabolites in the incubates of testes from 8 infertile men differed greatly from the remaining 25 patients and the normal control. The major steroids formed from pregnenolone by the testes of those 8 men were 17-hydroxypregnenolone, dehydroepiandrosterone, 20alpha-dihydropregnenolone and and 20alpha-dihydro-17-hydroxypregnenolone. Very small amounts of delta4-3 oxo products (progesterone, 17-hydroxyprogesterone, androstenedione and testosterone) were formed suggesting a deficiency of 3beta-hydroxy-steroid-dehydrogenase activity in the testes of these 8 men, possibly related to the derangement of their spermatogenic function.

Adult↗
PubMed1978

On the relative biological and immunoreactive potencies of luteinizing hormone in the oestradiol benzoate-treated male rat.

Mature male Sprague-Dawley rats were treated with 50 microgram oestradiol benzoate (OeB) per day for 7 days and killed 24 h after the last injection. Serum and pituitary luteinzing hormone (LH) levels were measured by RIA using NIAMDD rat hormone for iodination code I4 (rLH-I4) combined with either NIAMDD-anti-rat LH serum 3 (AS3) or serum 1 (AS1). Pituitary LH levels were also measured by an in vitro bioassay procedure in which testosterone production by dispersed rat testicular interstitial cells is related to the concentration of LH. Pituitary LH levels were reduced in OeB-treated rats regardless of which of the three assay systems was used. However, absolute values obtained in all three assays systems were statistically correlated. OeB-treatment did not significantly alter the relative bioassayable and immunoassayable potencies of LH present in pituitaries at autopsy. OeB-treated rats had non-detectable serum LH levels as measured by RIA using either AS1 or AS3 in combination with [125I]rLH-I4. These results confirm that chronic OeB-treatment decreases pituitary LH and suggest a decrease in serum LH as well. Comparison of the present with previous results revealed particular combinations of RIA reagents yield divergent estimates for serum LH in OeB-treated male rats. This situation emphasizes the need to carefully specify all RIA reagents used in any study since the results may very with different lots of RIA regents.

Animals↗
PubMed1978

A micro-scale method for liquid scintillation counting, applicable to radioimmunoassay of steroids and substances of comparable relative molecular mass.

A major expense of radioimmunoassay involving tritiated tracers is that of liquid scintillation counting. We present a micro-scale method that markedly reduces the cost of liquid scintillation counting. The radioimmunoassay is done in 10 X 50 mm tubes. The antibody-bound tracer is precipitated with a second antibody, the precipitate is resuspended in 0.1 ml of water, and 0.3 ml of dioxane is added. One milliliter of a toluene-based scintillation cocktail is added, and the tube is capped and placed in an adapter for liquid scintilation counting. When this method was applied to a double-antibody testosterone radioimmunoassay, it performed comparably to assays counted by the usual method.

Costs and Cost Analysis↗
PubMed1977

Direct measurement of androgen receptors in cultured Sertoli cells.

Cytoplasmic and nuclear forms of macromolecules with the properties of androgen receptors have been demonstrated by direct labeling techniques in cultured Sertoli cells. The cytoplasmic form was excluded from Sephadex G-200 and could be distinguished from androgen binding protein (ABP) on the basis of size, heat stability, relative electrophoretic mobility, and binding complex dissociation rate. When cultured Sertoli cells were incubated with 3H-testosterone, a time- and temperature-dependent accumulation of label into the nuclear fraction was observed, 46% of which crystallized as authentic testosterone. Specific binding was saturable with an apparent association constant of 0.4nM-1. Approximately 30% of the nuclear bound hormone was extracted within 1 h by 0.4M KCl and 34% of this was associated with macromolecular species as measured by gel filtration. Unlabeled androgens and to some degree progestogens competed with 3H-testosterone for binding sites. These data constitute direct evidence that Sertoli cells contain androgen receptors.

Animals↗
PubMed1977

In vitro steroid metabolic studies in human testes I: Effects of estrogen on progesterone metabolism.

A technique of incubation of testicular tissue in vitro with radiolabeled precursors was applied in the investigation of the steroid biosynthesis by testes of four young men after long-term, high-dose estrogen treatment. A positive correlation between plasma and testicular steroid levels, and in vitro capacity of the testes to metabolize progesterone was demonstrated. Estrogen administration produced a very significant inhibition of plasma and testicular levels of testosterone. The in vitro synthesis of testosterone from progesterone was very severely impaired; especially 17alpha-hydroxylation of progesterone. 20alpha-hydroxysteroid-dehydrogenase activity was found to be increased after estrogen treatment, both in vivo and in vitro. These findings suggest that testicular 17alpha-hydroxylase activity (and possibly also 17-20 lyase activity) is either under gonadotropin regulation, or is directly suppressed by estrogen. This could result by decreased enzyme synthesis, direct enzyme inhibition or affectation of the cofactors or cytochromes necessary for the enzymatic activity. 20alpha-reduction of C21-steroids would represent an alternative pathway for their catabolism, not regulated by gonadotropin or not affected by estrogen, that would be significant in situations with reduced 17alpha-hydroxylase activity.

Adult↗
PubMed1977

Effect of testosterone propionate on ABP levels in rats hypophysectomised at different ages using individual sampling.

The effect of age at hypophysectomy on the response of the regressed rat testis to testosterone propionate (TP) and FSH with respect to androgen-binding protein (ABP) levels was studied in individual animals. All treatments were begun 30 days after surgery. Treatment of rats 35, 45, 55 and 75 days of age at surgery with TP (1 mg/260 g for 25 days) significantly increased the level of ABP in the testes of animals in all age groups except those hypophysectomized at 35 days of age. TP treatment did not significantly elevate epididymal levels of ABP above those found in untreated rats in any age group. In animals hypophysectomized at 100 days of age, acute treatment (3 days) with FSH (150 and 300 mug/day) significantly increases the ABP levels per testis and per epididymis. Similar treatment with 750 mug TP/day did not result in a statistically significant increase in testicular ABP. No synergism between the two hormones was noted under the conditions described. Significant restoration of testicular ABP levels per mg protein was achieved with 1 mg TP/day by 5 days of treatment. Treatment of hypophysectomized adult rats with FSH raised the epididymal/testicular ratio of ABP to about 40% of that found in intact rats while comparable treatment with TP (750 mug/day for 3 days or 1 mg/day for 10 days) only slightly affected the ratio. It is postulated that FSH may facilitate ABP transport to the epididymis in addition to affecting its production by the testis.

Aging↗
PubMed1977

Frequency distribution of sperm counts in fertile and infertile males.

In this study the frequency distribution of sperm counts and total sperm counts from more than 4000 allegedly fertile males were compared with those of husbands in 1000 infertile couples. Significant differences were observed only at the lower end of the scale (sperm counts below 10 million/ml and total sperm counts below 25 million/ejaculate). Frequency distributions of sperm counts above 10 million/ml or total sperm counts above 25 million/ejaculate revealed little difference between the fertile and infertile groups. These data suggest that, unless other parameters are found to be abnormal, sperm counts and total sperm counts above 10 million/ml and 25 million/ejaculate, respectively, probably are not major factors in a couple's infertility.

Cell Count↗
PubMed1977

Relation between indices of semen analysis and pregnancy rate in infertile couples.

Both partners of 198 consecutive infertile couples were evaluated. Studies in the female included clinical evaluation of ovulation for a minimum of two menstrual cycles, investigation of tubal patency, and evaluation of sperm survival in cervical mucus. Six semen specimens were analyzed from each male. Laparoscopy, scrotal exploration, and testicular biopsies were performed as required. Where indicated, the female was treated intensively. The only therapy offered to the males was ligation of varicoceles, if present. The couples were grouped on the basis of sperm counts, total sperm counts, motile sperm counts, and total motile sperm counts, and the incidence of pregnancy was computed. Pregnancy rates of approximately 50% occurred in couples where sperm counts or total sperm counts were in the range of 5 to 60 million/ml or 25 to 200 million/ejaculate, respectively. When sperm counts were over 60 million/ml or total sperm counts over 200 million/ejaculate, pregnancy rates increased to above 70%. These observations emphasize the importance of considering infertility as a problem of a couple rather than as a specific disorder of one of the partners. These data also demonstrate a lack of direct correlation between sperm density in the ranges of 5 to 60 million/ml and pregnancy rates in couples where the wife is treated intensively.

Cell Count↗