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Biomedical subjects

S Oehninger

Publications and source records attributed to S Oehninger.

168 records · Page 10Linked to original sources
PubMedDate not supplied

Impact of cryopreservation on spermatozoa from infertile men: implications for artificial insemination.

The objective of this study was to evaluate the effect of cryopreservation-thawing on the quality of sperm from men with subfertile semen parameters. Twenty-seven patients with teratozoospermia, six of whom also had asthenozoospermia, were studied and their sperm parameters were compared to those of fertile donors (n = 71) in their fresh, post-thaw, and washed samples. After thawing, the percentage decrease in motility was significantly greater in patients than in donors, but the motility yield (post-thaw motility/prethaw motility) reached an average of 58% in the patient group vs. 68% in the donors (p = .02). No single characteristic of the fresh samples from patients or donors could significantly predict post-thaw outcome. For the patient group, however, multiple regression analysis provided a cutoff sperm concentration (50 x 10(6)/mL) and motility (40%) below which a very poor post-thaw recovery was obtained. The frozen-thawed-washed specimens had significantly higher velocity than the frozen-thawed samples, both in patients and donors. The results suggest that some patients with teratoasthenozoospermia yield acceptable sperm parameters after freezing-thawing-washing, and therefore these ejaculates could be used individually (or pooled) in artificial insemination.

Cryopreservation↗
PubMedDate not supplied

Hemizona assay: evaluation of fertility potential in patients with vasectomy reversal.

Approximately 40 to 60% of men who undergo a successful vasovasostomy have "functional failure" or failure to conceive even though active sperm are present. Factors of this functional failure include sperm abnormalities (oligoasthenoteratospermia) and antisperm antibodies. Nine male patients 32 to 43 years of age who underwent vasovasostomy were included in the study group. These patients demonstrated ductal patency 3 to 6 months after surgery. After attempts at fertility with their spouses failed, the couples underwent urological and gynecological evaluation. Semen parameters were recorded and further evaluation was performed using immobilizing and agglutination antibodies as well as direct immunobead test and the hemizona assay (HZA). Semen parameters presented varying levels of sperm concentration, percent motility, and morphology (strict). Antisperm antibodies were present in 4 of the 9 patients. Three of 4 patients with antibodies and 4 of 5 patients without antibodies benefitted from hemizona assay results in that it either supported a desired therapy or gave objective data that would dictate more aggressive therapy. Six men had a hemizona index of > 35%, predictive of adequate zona bind capability. Using these individual situations combined with gynecologic findings, recommendations are made as to identifying realistic options and therapeutic recommendations.

Adult↗
PubMedDate not supplied

Cryopreservation-Thawing of fractionated human spermatozoa is associated with membrane phosphatidylserine externalization and not DNA fragmentation.

The objective of these studies was to evaluate the effect of cryopreservation-thawing of human spermatozoa on DNA fragmentation and membrane integrity. This was a prospective, controlled cohort study, performed at a university-based infertility center. Ejaculates were examined from 5 donors and 16 men undergoing infertility evaluation. Purified sperm populations were prepared by gradient centrifugation, cryopreserved using a manual method and TEST-yolk buffer and glycerol (TYB-G), followed by quick-thaw. Annexin V binding was used for assessing membrane translocation of phosphatidylserine, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) was utilized for the evaluation of DNA fragmentation. The results were as follows: the percentage of live cells with intact membranes (annexin V-, live) was significantly reduced after cryopreservation-thawing. On the other hand, the percentages of live cells with phosphatidylserine translocation (annexin V-, live) and of necrotic (dead) cells increased significantly after thawing. TUNEL revealed percentages of cells with DNA fragmentation in the prefreeze and postthaw samples that were not significantly different. In a further attempt to examine differences in response to various cryoprotection protocols, experiments were carried out using no cryoprotection, glycerol alone, or TYB-G. Samples frozen with TYB-G demonstrated significantly higher percentages of live cells without phosphatidylserine translocation than the other conditions. We concluded that cryopreservation-thawing of human sperm from patients and donors was associated with membrane change, as revealed by membrane translocation of phosphatidylserine, while having no major impact on DNA fragmentation.

Annexin A5↗
PubMedDate not supplied

Effect of fucoidin on human sperm-zona pellucida interactions.

The authors recently reported that fucoidin (a polymer of predominantly L-fucose sulfate) produced a strong, significant, and dose-dependent inhibition of sperm-zona binding under hemizona assay conditions. The current studies were designed to evaluate the mechanisms underlying this inhibitory activity. Using computerized semen analysis, the monoclonal anti-sperm antibody T-6 and indirect immunofluorescence technique, and the fura-2 indicator, no significant impact of fucoidin on sperm motion parameters, on the spontaneous acrosome reaction, or its prerequisite, the increase in calcium influx, were observed. Subsequently, a mild acid hydrolysis of the fucoidin molecule was performed, followed by sizing hydrolysates in a Biogel P2 column and separating fractions (n = 6). All fucoidin fragments significantly inhibited tight binding of human sperm to human zona pellucida under hemizona assay conditions (range, 56%-94%) when tested individually. These results provide further evidence that the effect of fucoidin is produced by a receptor-ligand association.

Analysis of Variance↗
PubMedDate not supplied

Relationship between morphology and motion characteristics of human spermatozoa in semen and in the swim-up sperm fractions.

In this study, the authors evaluated the morphology pattern and motion characteristics of human spermatozoa before and after swim-up separation. Samples were divided into two, morphologically different groups according to the percentage of normal sperm forms assessed by the strict criteria of the Norfolk laboratory: "good"(G) and "poor" (P) prognosis patterns. The percentages of normal forms, slightly abnormal forms, and severe head defects were significantly different in the two groups. Motile characteristics were analyzed by a computerized semen analyzer with constant parameter settings. Before swim-up there were no significant differences in semen volume, percentage of neck and tail defects, concentration, or percentage of motility and linearity, but the mean velocity was higher in group G. After swim-up the percentage of motility, total number of motile cells, and recovery rate were higher for group G, and the incidence of severe head defects correlated negatively with the percentage of cells with a velocity of greater than 80 microns/sec. The results suggest that patients with a high incidence of sperm head defects have impaired original velocity, and swim-up selects for velocity as well as normal forms and motility. Although motility and velocity improved substantially after swim-up, the recovery rate and percentage of motility were significantly lower in the P group.

Cell Separation↗