Semen

About: Semen is a research topic. Over the lifetime, 14571 publications have been published within this topic receiving 407739 citations. The topic is also known as: come & ejaculate.

Sperm morphology assessment as an indicator of human fertilizing capacity.

Abstract: Semen samples from 95 men were examined by routine semen analysis and specific histologic staining for sperm morphology. The men were classified into fertile and infertile groups on the basis of clinical evaluation and in vitro testing, using the zona-free hamster egg penetration assay. Thirty men were designated as fertile, as they had fathered children and their sperm showed penetration of greater than 20% of the zona-free hamster eggs with the in vitro fertilization test. Subjects classified as infertile were men from infertile couples whose wives showed no evidence of infertility and whose in vitro fertilization ability was 10% or less. The semen analysis parameters of the fertile and infertile groups were significantly different. Fertile men had mean values of 108 X 10(6) sperm/ml, 61% motile, 64% normal forms (sperm with oval morphology), and 69% penetration in vitro. The mean values for infertile men were significantly lower: 42 X 10(6) sperm/ml, 45% motile, 32% normal forms, and 3.2% penetration in vitro. The importance of the morphology parameter was revealed by comparison of the percentage of penetration with count, motility, and morphology. Penetration correlated best with morphology (r = 0.730) as compared with motility (r = 0.451) and count (r = 0.605). The distribution of abnormalities in the infertile group revealed 81.6% with abnormal morphology (less than 50%), 53.8% with abnormal motility (less than 50%), and 38.5% with abnormal count (less than 20 million/ml). As a single parameter, decreased number of normal forms appears to be a good indicator for clinical infertility if in vitro fertilization testing is not available.

Standardization and quality control of sperm concentration and sperm motility counts in semen analysis.

Abstract: The paper reports a study of standardization and quality control of sperm concentration counts and visual motility assessments in human semen analyses performed for infertility investigations and from internal quality control procedures. Sperm concentration determinations were performed in Improved Neubauer haemocytometers on volumetric dilutions made using a positive displacement pipettor for sampling the liquefied semen. In addition to a standard 1 + 19 dilution a second dilution of either 1 + 9, 1 + 19 or 1 + 49 was made according to whether the estimated sperm concentration was less than 20, 20-100 or greater than 100 X 10(6)/ml respectively. The duplicate determinations of sperm concentration were highly significantly correlated (P much less than 0.001) with less than 5% variability. Parallel visual sperm motility assessments were made by two pairs of technicians and showed highly significant correlations (P much less than 0.001) between technicians in the determination of the percentages of motile and progressive spermatozoa as well as the subjective rating of sperm progressivity. When these values were incorporated into a calculated motility index which gave added weight to the progressive spermatozoa and to their quality of progression the correlations between technicians remained highly significant (P much less than 0.001) with average differences of the order of 1.0%. Therefore, provided that sufficient attention is paid to technician training, regular standardization checks and the use of only proven reliable procedures, quantitatively accurate values for sperm concentration and motility can be obtained in routine semen analyses.

Chromatin structural changes in sperm after scrotal insulation of Holstein bulls.

Abstract: The reported effects on semen quality ascribed to testicular heat stress generally relate to traits impacting sperm transport and fertilizing ability but not to the genetic material contained by the sperm. To characterize the effects of testicular heat stress on sperm chromatin, susceptibility of DNA in sperm nuclear chromatin to in situ acid denaturation was measured by flow cytometry after staining with acridine orange using the sperm chromatin structure assay (SCSA). Semen was collected from Holstein bulls at 3-day intervals, before and after 48-hour scrotal insulation, until the morphologically abnormal sperm content in raw semen exceeded 50%. After cryopreservation in egg yolk-citrate extender, semen was thawed and sampled during incubation in vitro at 38.5 degrees C. Overall, SCSA results showed that chromatin susceptibility to denaturation was increased for sperm collected post- vs. preinsulation and was more pronounced for sperm presumably in the testes during insulation than for those sperm presumably in the epididymides. Increased susceptibility was detected as early as the first collection postinsulation; however, chromatin of sperm presumably in the proximal epididymis during insulation did not appear to have been detrimentally affected. Chromatin susceptibility to denaturation increased with increased incubation time in vitro, but the rate of change in susceptibility during incubation did not differ among pre- vs. postinsulation specimens. We conclude that elevated scrotal temperatures adversely affect both epididymal and testicular sperm by reducing sperm chromatin stability. The effects of heat stress on the chromatin of epididymal sperm were more subtle than those exhibited by testicular sperm but detectable within close proximity to the heat stress event.

Role of granulocyte elastase and interleukin-6 in the diagnosis of male genital tract inflammation.

Abstract: Chronic genital tract inflammations are a frequent cause or at least a concomitant factor of male fertility disturbances. The diagnosis is difficult because of the mostly asymptomatic course of the disease. Therefore, determination of biochemical markers of inflammation in addition to the number of leucocytes in the seminal plasma has been recommended. The aim of the study was to find out whether determination of granulocyte elastase and interleukin-6 provide comparable and reliable results with regard to diagnosis of genital tract inflammation; in addition, the association between genital tract inflammation and semen quality should be evaluated with special focus on potentially disturbed sperm functions like sperm motility and DNA integrity. In a prospective study, the concentrations of interleukin-6 (IL-6) and granulocyte elastase were determined in seminal plasma samples from 340 patients to investigate the relationship with other parameters of genital tract inflammation such as the number of peroxidase-positive cells and conventional semen parameters. Microbiological investigations were included. As post-testicular inflammatory influences may cause sperm DNA damage, the correlation between IL-6 and elastase and DNA integrity was evaluated by the sperm chromatin structure assay. IL-6 and elastase were significantly correlated both with each other (P < 0.01) and the number of peroxidase-positive cells (P < 0.01). IL-6 showed a highly significant negative correlation with sperm vitality (P < 0.01) and a significant negative correlation with sperm motility (P < 0.05). Elastase concentrations were highly significantly associated with the number of peroxidase-positive cells (P < 0.01) and negatively correlated with sperm vitality (P < 0.01). Moreover, there were significantly negative correlations with sperm motility (P < 0.05), progressive motility according to WHO a quality (P < 0.05) as well as sperm morphology (P < 0.05). In addition, a significant negative correlation was observed between elastase concentrations and percentage of spermatozoa with intact DNA, which may suggest the use of anti-inflammatory treatment. It can be concluded that both IL-6 and granulocyte elastase are useful and suitable as markers for silent genital tract inflammation; in contrast to previous contributions there were clear correlations of IL-6 and granulocyte elastase with sperm parameters, the relationship of elastase with semen quality being more marked. Moreover, the results of the study confirm the need for a change of the threshold value of peroxidase-positive cells according to WHO definition to lower levels for definition of silent genital tract inflammation.