Biomedical subjects

R Singer

Publications and source records attributed to R Singer.

At least 199 records · Page 11Linked to original sources

PubMedDate not supplied

Semen volume and fructose content of human semen. Survey of the years 1980-1989.

The communication presents percentages of semen with low (less than 1 ml) and high (greater than or equal to 6 ml) volume and of semen with decreased fructose content (less than 1 ml) in the total number of 8,128 human specimens analyzed during the years 1980-1989. Percentages of low volume specimens and of specimens with decreased fructose content were found to increase with time. High volume semen lacked such trend.

Adolescent↗

PubMedDate not supplied

The influence of seminal plasma and polyaminic substances on the motility of isolated human sperm.

The purpose of the study was to examine the influence on the motility patterns of isolated human sperm of seminal plasma originating from semen of high and low motility, as well as of seminal plasma of azoospermic origin. Also assessed was the effect of incubation of sperm in the presence of solutions of the polyamines spermine, spermidine, and putrescine. The mean values of the obtained motility percentage and grade were related to the quality of sperm motility in semen and the quality of seminal plasma in that respect. The best results were obtained with specimens containing greater than or equal to 50% motile sperm and having a motility grade greater than or equal to 2. No relationship was found between the concentrations of polyamines in the seminal plasma and sperm motility of respective semen, as well as between the levels of polyamines and their effect on isolated sperm motility. It appears that the participation of polyaminic substances in the process of motility could be contributive and dependent on additional factors present in the semen.

Humans↗

PubMedDate not supplied

Andrological parameters in human semen of high (greater than or equal to 6 ml) and low (less than or equal to 1 ml) volume.

A study was carried out to evaluate 792 semen of high (greater than or equal to 6 ml) and low (less than or equal to 1 ml) volume and sperm counts ranging from 0.1 to 200 x 10(6) per ml. Particularly emphasized were: motility percentage and grade, percentage viability, morphologically normal sperm and immature cells, and the concentration of fructose in semen (mg/ml). The Duncan multiple range test and the Kruskal-Wallis test with multiple comparison of ranks were used in the statistical analyses. The results show that abnormal semen volume influence neither the basic tendency of andrological parameters to change in accordance with sperm counts of semen nor to correlate with each other. The quality of motility was significantly higher in specimens of high semen volume as compared to those of low semen volume. The concentration of fructose in semen was generally higher in specimens of high volumes than in those of low volumes, including semen devoid of sperm. It was assumed that in general increased semen volume does not affect the quality of other andrological parameters, thus being probably unrelated with fertility potential. The considerably lower values of both motility and viability characterizing the semen of low volume would suggest a lower fertility potential of specimens affected by this type of abnormality.

Fertility↗

PubMedDate not supplied

Peripheral neurotoxicity in workers exposed to inorganic mercury compounds.

Nerve conduction velocity (NCV) of the median motor, median sensory, and sural nerves was assessed in 16 workers chronically exposed to various inorganic mercury compounds. Exposed workers were compared with an unexposed control group using t test analyses. Slowing of the median motor nerve NCV was found, which was correlated with both increased levels of mercury in blood and urine, and with increased number of neurologic symptoms. Sensitive evaluation of neural function was found to be practical and informative for investigating mercury toxicity. Such evaluation can help determine safe mercury levels at the workplace.

Adult↗

PubMedDate not supplied

Andrological parameters in patients with varicocele and fertility disorders treated by high ligation of the left spermatic vein.

The results of surgical treatment of 50 subfertile patients with left varicocele are presented. Improvement of the spermiogram was noted as follows: 70% of patients had improvement of semen count, 48% of semen motility and 69.4% in the morphological pattern of spermatozoa. Pregnancy occurred in 50% of patients' wives. Eighty-four percent of the pregnancies took place during the first 12 months after the operation. A direct correlation was observed between the size of the varicocele and the number of pregnancies. Severely oligozoospermic patients with sperm count less than 10 million per milliliter semen constituted 72% of the men whose wives became pregnant. There was no statistically significant change after the operation in levels in the semen of luteinizing hormone, follicle stimulating hormone, testosterone and prolactin.

Adult↗

PubMedDate not supplied

Hyaluronidase activity in split human semen.

Hyaluronidase is an acrosomal enzyme which participates in the dissolution of the cumulus oophorus matrix, containing hyaluronic acid, and is essential for the fertilization process. In this study hyaluronidase activity was determined in two fractions of split normozoospermic and oligozoospermic human semen. The method consisted of measurements of areas of digestion of hyaluronic acid in agar (Petri dishes) as compared to activity obtained by commercial testicular hyaluronidase. It was found that the first splits of semen, which are generally characterized by higher sperm density and better quality of sperm, exhibit higher enzyme activity (136.0 +/- 11.6-207.0 +/- 15.1 micrograms/mL) as compared to the second splits (117.8 +/- 10-134.0 +/- 12.9 micrograms/mL).

Humans↗

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