Search PubMed⌕ Search

Biomedical subjects

R Singer

Publications and source records attributed to R Singer.

At least 181 records · Page 10Linked to original sources
PubMedDate not supplied

Separation of normozoospermic human spermatozoa into subpopulations by selective agglutination with peanut agglutinin.

Incubation of human spermatozoa of normozoospermic origin with the galactose specific lectin peanut agglutinin (PNA) resulted in agglutination of the majority of sperm. This finding enabled separation of sperm into two subpopulations. The major one, accounting for 87.0 +/- 12.7 (SD)% consisted of agglutinating sperm (PNA+), while the minor subpopulation (PNA-) did not bind the lectin. The correlation between the percentages of PNA- sperm and acrosome-damaged sperm, as detected by light microscopy prior to separation, was analysed and an overlapping has been found. Light and electron microscopy examination revealed that the PNA- cells were either acrosomeless or possessed severely damaged acrosomes while the PNA+ sperm were mostly free of such pathologies. Following treatment of sperm with fluorescin-conjugated PNA the single cells lacked any labeling while the agglutinates exhibited fluorescence. However, the binding of the lectin to sperm was non-uniform and differences in fluorescence intensity at various parts of the head have been observed. The sialic acid content in PNA+ sperm was found to be significantly higher (7.5 +/- 2.2 micrograms/10(8) sperm) as compared to PNA- sperm (2.1 +/- 0.6 micrograms/10(8) sperm). It was suggested that sialic acid content could be a biochemical indicator of acrosomal integrity. Separation of sperm by selective PNA agglutination might be valuable for elimination of sperm affected by acrosomal pathologies from the ejaculate.

Galactose↗
PubMedDate not supplied

A high proportion of double-headed and double-tailed sperm in semen of a human male. A case report.

We present the case of a patient whose semen contained 30% of sperm with double heads and double tails at various stages of attachment due to abnormal meiosis. The genital system, sperm density, endocrinological profile and karyotype were normal. It is postulated that abundance of the above-noted type of sperm pathology in the human semen might not necessarily be associated with oligozoospermia or fertility impairment.

Adult↗
PubMedDate not supplied

Separation of sub-populations of sperm with higher fertility potential from normal and pathological semen by peanut agglutinin.

Incubation of human sperm from semen with counts below 20 x 10(6)/ml with peanut agglutinin (PNA) resulted in agglutination of about 70% of sperm. An inverse correlation was found between non-agglutinating (PNA) sperm and sperm density (r = 0.48, p less than 0.01) and a direct correlation with acrosome-damaged sperm (r = 0.83, p less than 0.001). Binding of 125I-PNA to sperm revealed high, and possibly also low affinity binding sites on sperm from both normozoospermic and oligozoospermic origins. Quantitative transmission electron microscopy analysis revealed that agglutinated, PNA+, sperm had lower frequency of acrosomeless spermatozoa than PNA(-)-sperm (44% versus 77%) and higher fertility score (+0.18 +/- 0.1 and -1.5 +/- 0.87 respectively, p less than 0.01). Removal of PNA- sperm from oligozoospermic semen may increase the fertility score of the remaining sperm.

Cell Separation↗
PubMedDate not supplied

Inhibition of sialyl transferase activity by gossypol acetic acid in human seminal plasma.

Seventeen aliquots of 15 microliters seminal plasma of human origin were incubated with 25 micrograms, 15 micrograms, 5 micrograms and 2.5 micrograms gossypol acetic acid (GAA), dissolved in BWW containing 0.9% sodium chloride and 0.9% benzyl alcohol, at 37 degrees C for 60 minutes. Following incubation, activity of sialyl transferase (S.T.) was determined by a procedure involving incorporation of radioactive sialic acid into asialofetuin. The activity of S.T., expressed as cpm per hour per 15 microliters seminal plasma was compared to controls consisting in incubation of sperm in BWW containing 0.9% benzyl alcohol and 0.9% sodium chloride. The activity of S.T. in controls represented 61.3 +/- 8.0%-67.7 +/- 8.9% of the activity obtained by incubation with BWW only. GAA was found to exert a dose-dependent inhibition of S.T. activity, ranging from 38.3 +/- 20.6% to 53.4 +/- 19.4% (with 25 micrograms) and from 11.3 +/- 14.8% to 21.9 +/- 14.8% (with 2.5 micrograms).

Gossypol↗
PubMedDate not supplied

Low energy narrow band non-coherent infrared illumination of human semen and isolated sperm.

Sixty-two samples of human normal and abnormal semen and 23 samples of washed sperm were illuminated for 4 minutes with a narrow band non-coherent infrared device (BioBeam). Immediately after illumination the following parameters were examined in comparison with appropriate controls: motility, viability and morphology, fructose content of semen, acrosome reaction of sperm, viscosity of seminal plasma and analysis of the protein pattern. The mean value of motility grade calculated for the total number of 62 semen samples was 2.58 +/- 0.79 versus 2.17 +/- 0.75 (non illuminated controls), P less than 0.005. The mean value of motility grade of 23 samples of washed sperm was 2.89 +/- 0.77 versus 2.43 +/- 0.62, respectively (P less than 0.01). In two illuminated seminal plasma specimens, the viscosity was decreased by 8.8% and 14.8%, the protein content and pattern remained, however, unchanged. Neither the percentages of motile, viable and morphologically normal sperm, nor the fructose content of semen were found to be affected by the illumination.

Acrosome↗
PubMedDate not supplied

Ergonomics: your chair and you.

In a profession such as medical transcription which requires sitting for prolonged periods of time, finding the right chair can be as important to your job performance as using the latest state-of-the-art technology.

Ergonomics↗
PubMedDate not supplied

Some characteristics of azoospermic human semen.

Of 260 volume measurements and 265 fructose determinations on 257 azoospermic semen samples, the volume was normal (1-6 mL) in 78%, low in 16.7%, and high in 5.2%. The percentage of azoospermic samples with low volume was greater than that found for samples containing sperm. Mean fructose concentrations were similar in high-volume and normovolemic azoospermic samples, but significantly lower in low-volume samples. There was no correlation between (a) the etiology of the azoospermia and abnormal semen volume or fructose concentration (save for cases of obstruction and/or atrophic seminal vesicles) or (b) semen volume, fructose concentration, and serum LH, FSH, testosterone, or prolactin.

Adolescent↗
PubMedDate not supplied

Nontraumatic, acute neonatal paraplegia.

Nontraumatic, acute neonatal paraplegia with associated lower limb vascular phenomena is a relatively rare condition. Three such cases are reported. The paralysis is primarily motor with minimal neurologic recovery. Contractures and bizarre deformities develop at an early stage and necessitate repeated orthopaedic intervention. The most likely etiology appears to be a vascular insult to the spinal cord.

Catheterization, Peripheral↗
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↗