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.

Factors affecting the quality of cryopreserved buffalo (Bubalus bubalis) bull spermatozoa.

Abstract: Storage of buffalo (Bubalus bubalis) bull semen in the cryopreserved state is discussed in this article. Fertility rate in buffalo following artificial insemination with frozen-thawed semen is reviewed. To better understand the freezability of bubaline spermatozoa, the available data on biochemical components and the activity of specific enzymes of semen/spermatozoa are given. Moreover, the major factors that may influence the post-thaw viability and fertility of buffalo spermatozoa are examined in detail. In addition, suggestions for improvement in cryogenic procedures for buffalo spermatozoa are also given.

Decreased human semen quality and organochlorine compounds in blood

Abstract: BACKGROUND: Various studies have been performed in which potential effects of xenoestrogens on fertility or sperm parameters were investigated by comparing groups of subjects exposed to different levels of these chemicals. METHODS: In our study we used an alternative approach, as we selected one group of men with very poor semen quality and another group with normal semen quality and determined the blood organochlorine contents in order to determine whether a difference in these levels could be established. Organochlorine compounds, including polychlorinated biphenyls (PCB) and PCB metabolites, were detected using gas chromatography. The concentrations were compared between both groups, and related to semen parameters. RESULTS: A comparison of both groups did not reveal significant differences in organochlorine levels. Linear relationships were found when PCB and metabolite concentrations were related to the age of the volunteers. Focusing on the subgroup of men with normal semen quality showed that sperm count and sperm progressive motility were inversely related to the concentrations of PCB metabolites within this group. CONCLUSIONS: The finding of a significantly decreased sperm count in relation to an elevated PCB metabolite level within the subgroup of men with normal semen quality is important. This is the first time that a correlation between exposure to environmental pollutants with endocrine-disrupting capacity and human sperm quality has been observed.

Resistance of HIV-1 to antiretroviral agents in blood and seminal plasma: implications for transmission

Abstract: Objectives: To evaluate blood and genital secretions from HIV-infected men for HIV-1 resistant to antiretroviral agents. Design: A longitudinal study of 11 men with HIV infection and persistent detectable HIV RNA levels in blood and semen on antiretroviral therapy. Methods: HIV-1 from the blood and seminal plasma, obtained before the initiation of a new therapeutic regimen and on therapy, were evaluated by population-based sequencing of reverse transcriptase (RT) and protease RNA for the development of resistance to antiretroviral therapy. The genetic relatedness of sequences over time was compared. Results: RT genotypic resistance markers were present in seminal plasma at baseline in three out of six individuals with previous RT inhibitor experience. Eight out of 10 men, from whom the viral sequence was available on new therapy, demonstrated the evolution of new resistance mutations in the blood or seminal plasma, or both. The evolution of resistance mutations in blood and semen were frequently discordant, although over time similar patterns were seen. In two individuals, protease inhibitor resistance mutations evolved in the blood but not in the major variant in seminal plasma. Comparisons of the viral sequences between blood and seminal plasma from six men revealed two patterns. Three men showed a clustering of sequences from blood and semen. Three had sequences that appeared to evolve separately in the two compartments. Conclusions: HIV-1 variants with genotypic resistance markers are present in the male genital tract and evolve over time on incompletely suppressive antiretroviral therapy. The absence of genotypic changes consistent with protease inhibitor resistance in the semen, despite their presence in blood plasma, suggests the possibility of limited penetration of these agents into the male genital tract. Sexual transmission of resistant variants may have a negative impact on treatment outcome in newly infected individuals and on the spread of the diseases within a population. Therapeutic strategies that fully suppress HIV-1 in the genital tract should be a public health priority.

Effect of cryopreservation of bovine sperm organelle function and viability as determined by flow cytometry.

Abstract: Flow cytometry was used to compare the functional status of fluorescently stained sperm organelles from 12 Holstein bulls after storage for 24 h at 5 degrees C and after cryopreservation. The organelle-specific stains, SYBR-14 and LysoTracker Green DND-26, identified spermatozoa with intact plasmalemma and those with intact acrosomes, respectively. The mitochondria-specific stain, 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolyl-carbocyan ine iodide (JC-1), identified two populations of spermatozoa. One population stained red-orange because the JC-1 accumulated in the mitochondria as aggregates (characteristic of cells exhibiting a high membrane potential); a second population stained green because of JC-1 monomers within the mitochondria (characteristic of cells exhibiting a lower membrane potential). Analysis of variance revealed that within bulls, the properties of sperm viability, intact acrosomes, and mitochondrial status differed in spermatozoa stored for 24 h (p 0.11). Linear regression analyses resulted in significant models in which the proportions of stained spermatozoa stored for 24 h were indicative of those proportions observed in the cryopreserved fractions. These findings suggest that the plasmalemma, the acrosome, and the mitochondria of unfrozen spermatozoa varied as to their functional status. The cryopreservation process, however, resulted in a more uniform status of sperm organelles.