Emil Steinberger

Bio: Emil Steinberger is an academic researcher from University of Texas at Austin. The author has contributed to research in topics: Testosterone & Androstenedione. The author has an hindex of 44, co-authored 141 publications receiving 5094 citations. Previous affiliations of Emil Steinberger include Albert Einstein Medical Center & St. Joseph Hospital.

Replication Pattern of Sertoli Cells in Maturing Rat Testis in Vivo and in Organ Culture

Abstract: The pattern of Sertoli cell replication in maturing rat testes was investigated in vivo and in organ culture, using pulse labeling with ‘H-thymidine and radioautography. The labeling index of Sertoli cells was found to be related to the age of the animals. It was highest in testes of newborn animals and decreased with age, most drastically on day 11. No labeled Sertoli cells were found after postnatal day 15. This pattern appeared to be independent of extragonadal in vivo influences since it was retained in isolated testes grown in organ culture.

The role of androgens in the initiation of spermatogenesis in man.

Abstract: Morphologic and steroid biochemical studies were performed on surgical specimens from a 6-yr-old boy with a Leydig cell tumor. Active spermatogenesis to early spermatid stage was found in the testicular tissue of the tumorbearing testis, and absence of spermatogenesis was observed in a biopsy of the contralateral testis. Tumor tissue actively metabolized tritiated progesterone, pregnenolone and cholesterol to testosterone and androstenedione.1 Correlation of these data with plasma androgen levels from this patient's peripheral and spermatic veins led the authors to conclude that, as in lower species, high local levels of androgen will initiate spermatogenesis in man.

World Health Organization reference values for human semen characteristics

Abstract: BACKGROUND Semen quality is taken as a surrogate measure of male fecundity in clinical andrology, male fertility, reproductive toxicology, epidemiology and pregnancy risk assessments. Reference intervals for values of semen parameters from a fertile population could provide data from which prognosis of fertility or diagnosis of infertility can be extrapolated. METHODS Semen samples from over 4500 men in 14 countries on four continents were obtained from retrospective and prospective analyses on fertile men, men of unknown fertility status and men selected as normozoospermic. Men whose partners had a time-to-pregnancy (TTP) of < or =12 months were chosen as individuals to provide reference distributions for semen parameters. Distributions were also generated for a population assumed to represent the general population. RESULTS The following one-sided lower reference limits, the fifth centiles (with 95th percent confidence intervals), were generated from men whose partners had TTP < or = 12 months: semen volume, 1.5 ml (1.4-1.7); total sperm number, 39 million per ejaculate (33-46); sperm concentration, 15 million per ml (12-16); vitality, 58% live (55-63); progressive motility, 32% (31-34); total (progressive + non-progressive) motility, 40% (38-42); morphologically normal forms, 4.0% (3.0-4.0). Semen quality of the reference population was superior to that of the men from the general population and normozoospermic men. CONCLUSIONS The data represent sound reference distributions of semen characteristics of fertile men in a number of countries. They provide an appropriate tool in conjunction with clinical data to evaluate a patient's semen quality and prospects for fertility.

Sperm Morphology, Motility, and Concentration in Fertile and Infertile Men

Abstract: Background Although semen analysis is routinely used to evaluate the male partner in infertile couples, sperm measurements that discriminate between fertile and infertile men are not well defined. Methods We evaluated two semen specimens from each of the male partners in 765 infertile couples and 696 fertile couples at nine sites. The female partners in the infertile couples had normal results on fertility evaluation. The sperm concentration and motility were determined at the sites; semen smears were stained at the sites and shipped to a central laboratory for an assessment of morphologic features of sperm with the use of strict criteria. We used classification-and-regression-tree analysis to estimate threshold values for subfertility and fertility with respect to the sperm concentration, motility, and morphology. We also used an analysis of receiver-operating-characteristic curves to assess the relative value of these sperm measurements in discriminating between fertile and infertile men. Results The su...

Advances in male contraception.

Abstract: Despite significant advances in contraceptive options for women over the last 50 yr, world population continues to grow rapidly. Scientists and activists alike point to the devastating environmental impacts that population pressures have caused, including global warming from the developed world and hunger and disease in less developed areas. Moreover, almost half of all pregnancies are still unwanted or unplanned. Clearly, there is a need for expanded, reversible, contraceptive options. Multicultural surveys demonstrate the willingness of men to participate in contraception and their female partners to trust them to do so. Notwithstanding their paucity of options, male methods including vasectomy and condoms account for almost one third of contraceptive use in the United States and other countries. Recent international clinical research efforts have demonstrated high efficacy rates (90-95%) for hormonally based male contraceptives. Current barriers to expanded use include limited delivery methods and perceived regulatory obstacles, which stymie introduction to the marketplace. However, advances in oral and injectable androgen delivery are cause for optimism that these hurdles may be overcome. Nonhormonal methods, such as compounds that target sperm motility, are attractive in their theoretical promise of specificity for the reproductive tract. Gene and protein array technologies continue to identify potential targets for this approach. Such nonhormonal agents will likely reach clinical trials in the near future. Great strides have been made in understanding male reproductive physiology; the combined efforts of scientists, clinicians, industry and governmental funding agencies could make an effective, reversible, male contraceptive an option for family planning over the next decade.