Biomedical subjects

D Katsoff

Publications and source records attributed to D Katsoff.

24 records · Page 2Linked to original sources

PubMedDate not supplied

Male:female sex ratio in births resulting from IVF according to swim-up versus Percoll preparation of inseminated sperm.

Two centers have independently reported a higher rate of male to female births following insemination of sperm prepared by a modified swim-up technique. The principle of the modified swim-up is that a small percentage of the x-bearing sperm are the fastest and travel to the top of the supernatant, followed by the y-bearing sperm; the bulk of the x-bearing sperm remain in the pellet. In this technique, the very top layer is discarded and the resulting supernatant is collected, leaving only the pellet. In contrast, with the conventional swim-up technique, the entire supernatant is collected. The study presented herein retrospectively evaluated the male to female sex ratio of births from in vitro fertilization using standard swim-up technique and compared these results to the ratio obtained from separating with Percoll. There were 53% male births with swim-up vs. 54% with Percoll in singleton pregnancies and 51% males with swim-up vs. 40% with Percoll with multiple births. Thus, conventional swim-up alone does not increase percentage of male births.

Cell Separation↗

PubMedDate not supplied

Failure of test yolk buffer to decrease antisperm antibodies on sperm.

The objective of this study was to evaluate whether the suspension of sperm naturally bound or artificially coated with antisperm antibody (ASA) in test yolk buffer (TYB) will reduce the percentage of sperm positive for ASA. Attempts were made to repeat a study performed by Lam et al., in which they claimed a significant decrease in percentage of sperm positive for both IgA and IgG. Furthermore, the study attempted to determine if this methodology would similarly reduce the percentage of sperm naturally bound with ASA. There was no reduction in postincubation levels in percentage of sperm having attachment of IgA or IgG in either the sperm specimens naturally bound with ASA or donor sperm artificially coated with antibodies. Incubation in TYB does not appear to be an effective method to reduce the percentage of sperm bound with ASA. Possibly, it could reduce the amount of ASA bound to each sperm, but this would have to be proven by other studies.

Antibodies↗

PubMedDate not supplied

Effect of an intermediate hold with vapor freezing on subsequent hypoosmotic swelling in thawed sperm.

Cryopreservation and thawing of sperm exerts an adverse effect on functional integrity of the sperm membrane as measured by the hypoosmotic swelling (HOS) test. Supercooling using the liquid nitrogen (LN2) vapor technique may damage membranes by favoring ice crystal formation. Slight slowing of the cooling process may allow escape of intracellular fluid. This study was conducted to evaluate modification of the LN2 vapor technique by employing an intermediate hold in a freezer (to slow down the rate of cooling) on HOS scores on specimens thawed 1 month after freezing. Semen samples were obtained from male partners of infertile couples with a requirement of a baseline HOS score < 70% but > or = 60%. The HOS test was performed on the unprepared semen sample prior to freezing and immediately post-thaw 1 month later on the aliquot frozen with LN2 vapors only vs. the equal fraction subjected to an intermediate hold. The mean initial HOS score was 68.5% and was 47% in thawed specimens that had been cryopreserved with and without an intermediate hold. There were no differences in the percentage of specimens exhibiting a > 50% HOS score following vapor freeze (70%) or vapor freeze with a hold (74%). Thus, these data do not demonstrate any advantage of slowing the vapor freezing process by utilizing an intermediate hold.

Cell Membrane↗

PubMedDate not supplied

Effect of pentoxifylline added to freezing media on subsequent post-thaw hypoosmotic swelling test and other semen parameters.

This study evaluated the effects of pentoxifylline (PTX) on post-thaw semen parameters as well as the hypoosmotic swelling (HOS) test. Fourteen samples were evaluated for volume, count, motility, % grade A sperm, and HOS test. Two aliquots were frozen, one in freezing medium and the other in a 3 mM solution of PTX and freezing medium. Both groups were frozen in liquid nitrogen vapors for 30 min. Thawing was performed at 37 degrees C for 15 min, followed by a wash with 2 parts 0.5% HSA/MHTF to 1 part sample. Pellets were resuspended in 0. MHTF and then evaluated as described above. In addition, motility was evaluated 2 h post-thaw. Following freeze-thaw, the mean motile densities were similar (17.5 x 10 motile/mL vs. 20.4 x 10(6) motile/mL for PTX and control, respectively). Two hours post-thaw, the PTX group had a mean sperm motility of 31.3% vs. 37.7% for the control group (p > .05). There were no significant differences in % grade A sperm in PTX (13.0%) vs. control (12.0%). Similarly, HOS scores did not improve following cryopreservation (43.0% and 50.6% for PTX and control, respectively). Thus, no improvement was found by freezing sperm with PTX.

Analysis of Variance↗

PubMedDate not supplied

The value of motile density, strict morphology, and the hypoosmotic swelling test in in vitro fertilization-embryo transfer.

This study was conducted to evaluate the effect of a single abnormal semen parameter on subsequent implantation and pregnancy rates (PRs) following in vitro fertilization-embryo transfer (IVF-ET). The parameters evaluated were motile density (MD), strict normal morphology (SNM), and the hypoosmotic swelling (HOS) test. A total of 592 IVF cycles were evaluated. Patients were divided into four groups each with one abnormal semen parameter except for the control: group 1 (n = 509), control group: MD > or = 10 x 10(6)/mL, HOS > or = 50%, SNM > or = 4%; group 2 (n = 51): HOS and SNM normal, MD < 10 x 10(6)/mL; group 3 (n = 14): MD and SNM normal, HOS < 50%; group 4 (n = 18): MD and HOS normal, SNM < 4%. The implantation rate was 10.2% for the control group. The implantation rate was similar for the low MD (9.0%) and the low SNM (16.7%) groups. However, the low HOS group had a significantly lower implantation rate (0%). The clinical PRs are similar in the control group and low MD and SNM groups, but decreased in the low HOS group (21.5, 15.0, 30.8, and 0%, respectively). Ongoing PRs were also similar with the exception of the low HOS group (0%). This comparative study supports previous conclusions that the subnormal HOS test is the best semen parameter available that predicts poor PRs. It also suggests that some qualitative defect in the embryos may result from defective sperm membranes, resulting in an apparently normal appearance but physiologically defective embryo.

Cell Count↗

PubMedDate not supplied

Improved results of thawed sperm cryopreserved with slow stage cooling with a cellevator.

There is a need to develop a sperm cryopreservation technique that will allow good pregnancy rates following intrauterine insemination of thawed semen specimens that have been frozen prior to sperm-destructive procedures, such as surgery, chemotherapy, or radiation therapy. A slower cooling rate using a commercial semiprogrammable freezer may provide improved post-thaw motility and hypoosmotic swelling (HOS) test scores. However, the cost of this apparatus precludes it from being used in most andrology centers. This study compares the efficacy of slow stage cooling using an inexpensive cellevator (a device used to freeze lymphocytes) to liquid nitrogen vapor freezing. The semen from 27 males was equally divided and one aliquot was cryopreserved with the cellevator stage cooling and the other with the liquid nitrogen vapor technique. The percent motility and percent grade A sperm post-thaw were significantly higher when cryopreserved with the cellevator than with vapor freezing, as was the mean percentage of sperm showing HOS changes.

Adult↗