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Sperm Preparation (sperm + preparation)

Distribution by Scientific Domains

Medical Sciences	83%

Selected Abstracts

Interaction between leucocytes and human spermatozoa influencing reactive oxygen intermediates release

INTERNATIONAL JOURNAL OF ANDROLOGY, Issue 2 2004
Monika Fr
Summary The relationship between the presence of white blood cells (WBCs) and the fertilizing potential of human semen is still an open question. It is well known that the presence of leucocytes in human semen can be related to the production of reactive oxygen intermediates (ROI). Semen samples were obtained from 15 normozoospermic men and leucocytes were isolated from heparinized blood drawn from 15 volunteers. Lucigenin and luminol-mediated chemiluminescence assays were used to determine reactive oxygen species (ROS) generation by non-activated or activated leucocytes through 12-myristate-13-acetate or N-formyl-methionyl-leucyl-phenyalanine (FMLP) before the addition of spermatozoa isolated by swim-up or Percoll procedures. All spermatozoal fractions used in this study were characterized by defining their motility, morphology and viability. The levels of ROS formation by non-activated as well as stimulated leucocytes were significantly decreased after addition of swim-up separated spermatozoa (p < 0.01). The ability to inhibit the basal chemiluminescence was of lower degree for spermatozoa isolated from 90% Percoll fractions than for swim-up sperm. However, addition of sperm cells from 47% Percoll fraction was found to increase both lucigenin and luminol signals. Moreover, the determined ROI levels changed depending on the type of inducing factor used for oxidative burst. Then, spermatozoa selected by swim-up procedure although with only slightly higher viability and morphology than sperm obtained from 90% Percoll fraction clearly exhibited much higher capacity to inhibit ROI secretion by receptor-stimulated leucocytes (FMLP-activation) than Percoll fractionated sperm. Such results may indicate that within normal semen may exist sperm subpopulations with different biochemical mechanisms controlling the interaction between spermatozoa and contaminating leucocytes. When ROI levels contained in normozoospermic semen are dependent on the WBCs activation, it seems that spermatozoa with preserved normal functional competence are able to defend themselves against leucocytes-derived ROI. Also for normozoospermic ejaculates, swim-up sperm may improve semen antioxidant characteristics when comparing with Percoll (90%) separated sperm. It may help for optimal sperm preparation when assisting to infertility treatment. [source]

Update on Semen Technologies for Animal Breeding,

REPRODUCTION IN DOMESTIC ANIMALS, Issue 1 2006
JM Morrell
Contents Despite the scale of the livestock breeding industry, where many millions of insemination doses are prepared each year, sperm preparation techniques are used infrequently in animal assisted reproduction compared with its human counterpart. However, some of the techniques used for human sperm preparation, for example, density gradient centrifugation, improve the quality of sperm preparations which is, in turn, reflected by an increased conception rate. The preparation technique separates motile spermatozoa with normal morphology and intact DNA from the total sperm population, leaving behind immature or senescent spermatozoa, morphologically abnormal ones and those with damaged DNA. Furthermore, the motile spermatozoa are removed from the seminal plasma which carries cells, cellular debris and reactive oxygen species, as well as pathogens. Gradient-prepared spermatozoa survive longer, either in liquid storage or when cryopreserved, and are free of bacteria and viral infectivity if prepared carefully. Preparation techniques such as density gradient centrifugation, or the simplified single layer centrifugation technique, have considerable potential for aiding sperm preparation from poor quality semen samples, such as may be obtained from unselected semen donors in captive breeding programmes, or from performance horses. Moreover, the removal of pathogens has important implications, both for disease control and for avoiding the use of antibiotics in semen extenders, which can be detrimental to sperm survival. [source]

Relationship between hyaluronic acid binding assay and outcome in ART: a pilot study

ANDROLOGIA, Issue 5 2010
M. Nijs
Summary The sperm,hyaluronan binding assay (HBA) is a diagnostic kit for assessing sperm maturity, function and fertility. The aim of this prospective cohort pilot study was to evaluate the relationship between HBA and WHO sperm parameters (motility, concentration and detailed morphology) and possible influence of sperm processing on hyaluronic acid binding. A cohort of 68 patients undergoing a first combo in vitro fertilisation/intracytoplasmic sperm injection treatment after failure of three or more intrauterine insemination cycles were included in the study. Outcome measures studied were fertilisation rate, embryo quality, ongoing pregnancy rate and cumulative pregnancy rate. HBA outcome improved after sperm preparation and culture, but was not correlated to detailed sperm morphology, concentration or motility. HBA did not provide additional information for identifying patients with poor or absent fertilisation, although the latter had more immature sperm cells and cells with cytoplasmic retention present in their semen. HBA outcome in the neat sample was significantly correlated with embryo quality, with miscarriage rates and ongoing pregnancy rates in the fresh cycles, but not with the cumulative ongoing pregnancy rate. No threshold value for HBA and outcome in combo IVF/ICSI treatment could be established. The clinical value for HBA in addition to routine semen analysis for this patient population seems limited. [source]

Na+/K+ATPase regulates sperm capacitation through a mechanism involving kinases and redistribution of its testis-specific isoform

MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 2 2010
Larissa D. Newton
Incubation of bovine sperm with ouabain, an endogenous cardiac glycoside that inhibits both the ubiquitous (ATP1A1) and testis-specific ,4 (ATP1A4) isoforms of Na+/K+ATPase, induces tyrosine phosphorylation and capacitation. The objectives of this study were to investigate: (1) fertilizing ability of bovine sperm capacitated by incubating with ouabain; (2) involvement of ATP1A4 in this process; and (3) signaling mechanisms involved in the regulation of sperm capacitation induced by inhibition of Na+/K+ATPase activity. Fresh sperm capacitated by incubating with ouabain (inhibits both ATP1A1 and ATP1A4) or with anti-ATP1A4 immunoserum fertilized bovine oocytes in vitro. Capacitation was associated with relocalization of ATP1A4 from the entire sperm head to the post-acrosomal region. To investigate signaling mechanisms involved in oubain-induced regulation of sperm capacitation, sperm preparations were pre-incubated with inhibitors of specific signaling molecules, followed by incubation with ouabain. The phosphotyrosine content of sperm preparations was determined by immunoblotting, and capacitation status of these sperm preparations were evaluated through an acrosome reaction assay. We inferred that Na+/K+ATPase was involved in the regulation of tyrosine phosphorylation in sperm proteins through receptor tyrosine kinase, nonreceptor type protein kinase, and protein kinases A and C. In conclusion, inhibition of Na+/K+ATPase induced tyrosine phosphorylation and capacitation through multiple signal transduction pathways, imparting fertilizing ability in bovine sperm. To our knowledge, this is the first report documenting both the involvement of ATP1A4 in the regulation of bovine sperm capacitation and that fresh bovine sperm capacitated by the inhibition of Na+/K+ATPase can fertilize oocytes in vitro. Mol. Reprod. Dev. 77: 136,148, 2010. © 2009 Wiley-Liss, Inc. [source]