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Biomedical subjects

R Singer

Publications and source records attributed to R Singer.

193 records · Page 11Linked to original sources
PubMedDate not supplied

Total and free testosterone and estradiol in human semen.

Total and free testosterone (T) and estradiol (E2) were determined by a radioimmunoassay technique in 30 normozoospermic and oligozoospermic human semen samples. The mean amounts of total T ranged from 25.1 +/- 7.4 to 32.5 +/- 12.2 ng/100 mL, and those of the free hormone from 7.0 +/- 2.8 to 7.9 +/- 2.3 ng/100 mL. The values for E2 were 10.5 +/- 4.4 to 11.2 +/- 4.5 pg/mL and 2.3 +/- 1.1 to 3.2 +/- 2.6 pg/mL, respectively. There was no correlation between sperm density of semen and the levels of T and E2. It is suggested that the nonspecific binding of T and E2 in semen provides a physiological reservoir for active, free T and E2 and that an appropriate ratio of free T to free E2 in semen may be crucial in the processes that lead to fertilization.

Adult↗
PubMedDate not supplied

Sialic acid content of human spermatozoa in relation to age and quality of sperm.

Sialic acid (SA) has been estimated in human spermatozoa separated according to age by the use of a discontinuous gradient of human serum albumin (HSA), and according to quality (viability and motility) by the use of a discontinuous gradient of bovine serum albumin (BSA). The amount of SA in the "mature" sperm was 3.5 +/- 0.7 (SD) micrograms/mg protein, whereas in the immature sperm subpopulation, enriched with morphologically abnormal sperm, it was 6.9 +/- 3.4 micrograms/mg protein (P = .05). SA estimated in spermatozoa separated according to quality had values of 3.6 +/- 1.2 micrograms/mg protein in sperm of higher quality and 4.1 +/- 1.3 micrograms/mg protein in that of lower quality; this difference was not of statistical significance. It is suggested that changes in SA levels might reflect differences in the degree of sialylation of protein in the subpopulation of sperm, and thus be related to various stages in the fertilization process.

Cell Separation↗
PubMedDate not supplied

The evaluation of routine andrological parameters in human serum.

A study was carried out to evaluate the andrological parameters in 540 human semen specimens divided into groups according to sperm counts. The parameters were: motility percentage and grade, percentage of viability and of morphologically normal sperm and immature cells. The Duncan multiple range test and the Kruskal-Wallis test with multiple comparison of ranks were used in the statistical analyses. Of particular interest, among other our findings, were the significant differences obtained by comparing the group with sperm counts up to 5 x 10(6) per ml semen and that with counts ranging from 5.1 to 10 x 10(6) per ml semen. This was true for all parameters with the exception of semen volume. Comparison of the oligozoospermic groups (up to 20 x 10(6)/ml) with those having higher sperm counts also showed significant differences. There was a trend towards improvement of the examined parameters with the increase in sperm density, but with a remarkable heterogeneity particularly within the oligozoospermic groups. In all groups motility, viability and morphological normality of sperm showed a positive correlation with each other. "Normal values" of the parameters studied could be derived from scatterplot charts over the entire range of sperm counts and from the statistical evaluation of the grouped material.

Humans↗
PubMedDate not supplied

Separation of human semen on Percoll gradients: effect on percentage of motile and morphologically normal sperm and proportion of acrosome reacted sperm.

OBJECTIVES: To examine whether sperm motility and morphology correlate with ability to undergo the acrosome reaction in vitro. METHODS: Sixty-one seminal specimens were separated on a discontinuous Percoll gradient (70%, 40%). Percentages of motile and morphologically normal sperm, their motility grade, and percentages of acrosome-reacted sperm before and following acrosome reaction inducing treatment were estimated. RESULTS: Percentage of motile sperm from normozoospermic specimens increased from whole semen (47.6 +/- 5.6) to sediments (59.6 +/- 13.0). Motility grade exhibited a similar trend (2.1 +/- 0.5 and 3.6 +/- 0.5-scale of 1-4). Percentage of morphologically normal sperm increased from semen (27.3 +/- 10.9) to sediment (53.8 +/- 14.8). All differences were statistically significant, (P < 0.00). In abnormal semen the motility grade and percentage of morphologically normal sperm also increased from semen to sediment (1.9 +/- 0.4 to 3.2 +/- 0.8 and 17.7 +/- 7.8 to 37.1 +/- 15.4 respectively, (P < 0.001). Percentages of motile sperm were similar. In normozoospermic sediments, both non-treated or treated to induce the acrosome reaction, proportions of acrosome-reacted sperm were significantly higher than in semen (18.3 +/- 6.9% and 20.0 +/- 6.5% vs. 6.8 +/- 4.2% respectively, P < 0.001). A similar trend was obtained using abnormal aliquots; however, the acrosome-reacted sperm accounted for only 9.0 +/- 5.1% and 10.8 +/- 4.3% versus 5.4 +/- 2.8% (P < 0.025). CONCLUSIONS: Morphology and motility of sperm were correlated with the proportion of acrosome-reacted sperm.

Acrosome↗
PubMedDate not supplied

Percentages of acrosome-reacted sperm in human semen close to liquefaction and following acrosome-reaction inducing treatment.

OBJECTIVES: To compare spermatozoa from normal and subnormal seminal specimens in their ability to undergo the acrosome reaction, as defined by the triple-staining method. METHODS: Normal (39) and abnormal (23) specimens were examined by staining promptly after liquefaction. In a total of 32 specimens, the reaction was examined before and after acrosome-reaction-inducing treatment, which was essentially incubation of isolated sperm in BWW containing 0.3% BSA and 4 mM calcium chloride. RESULTS: Percentage of vital acrosome-reacted sperm (true acrosome reaction) of untreated specimens: normal, 10.0 +/- 4.9%, abnormal, 5.3 +/- 3.6% (P < .001). After treatment: increase in reacted sperm from normal specimens, 9.0 +/- 7.1% to 22.7 +/- 14.0% (P = .005); abnormal specimens, 5.4 +/- 2.9% to 7.3 +/- 4.2% (NS). CONCLUSIONS: Low capability of sperm to undergo the acrosome reaction might be a decisive factor in the low fertility potential characterizing the majority of abnormal semen. Effort in infertility treatment should be directed to increasing the proportion of acrosome-reacted sperm.

Acrosome↗