Mariano Perez-Pelaez

Leucospermia and the fertilizing capacity of spermatozoa.

Ejaculates obtained from men attending an in vitro fertilization (IVF) program were analyzed to determine the effect of the presence of leucocytes in semen on the ability of sperm in that semen to fertilize oocytes. The mean (+/- S.E.) concentration of leucocytes in 103 ejaculates was 0.62 X 10(6)/ml (+/- 0.09) with a range of 0.1 X 10(6) or less per ml to 7.0 X 10(6)/ml. The leucocyte concentration demonstrated a significant (p less than 0.05) but inverse relationship with the fertilizing capacity of spermatozoa. Though not statistically significant, the leucocyte concentration also demonstrated an inverse relationship to sperm motility and normal morphology. These results suggest that the presence of leucocytes in an ejaculate cannot be used as the sole indicator of the fertilizing capacity of spermatozoa in that ejaculate.

Concentration of viable spermatozoa for artificial insemination

Glass wool microfiber code 112 (approximately 30 mg) was gently packed to a depth of 3 mm in a 3-ml disposable syringe barrel. The column was rinsed repeatedly with Tyrode solution to remove loose glass wool fibers. Approximately 0.3 to 0.5 ml of concentrated spermatozoa (after centrifugation of semen at 500 X g for 5 minutes) was layered over the wet column and allowed to filter by gravity. The filtered spermatozoa demonstrated a significantly higher (P less than 0.001) mean percentage of motility, progressive motility, sperm unstained by eosin Y dye, and sperm with functionally intact membranes. Although there was a considerable loss of sperm, the filtered specimen contained all viable spermatozoa present before filtration. Therefore, it appears that this procedure yields a high percentage of viable spermatozoa, potentially capable of fertilization, for use in in vitro fertilization or, possibly, artificial insemination.

Nonbeneficial effects of glycerol on the oocyte penetrating capacity of cryopreserved and incubated human spermatozoa

The effect of cryopreservation on human spermatozoa in the presence or absence of glycerol was assessed by using sperm motility, functional integrity of sperm membrane, and denuded hamster oocyte penetration tests. Glycerol treated cryopreserved spermatozoa yielded a significantly higher (P less than 0.01) percentage of motile sperm and percentage of sperm with functionally intact membrane immediately after thawing than the spermatozoa not treated with glycerol but cryopreserved. However, no significant difference was observed between these cryopreserved spermatozoa (either treated or untreated with glycerol) on the percentage of motile sperm and the rate of oocyte penetration when the sperm were washed and incubated for 2 hr in a medium containing no glycerol. Thus, it appears glycerol may not be beneficial, since cryopreservation of spermatozoa either treated or untreated with glycerol essentially yields similar oocyte-penetrating capacity of sperm.

Morphometric and volumetric comparisons of human spermatozoa

Morphometric measures and volumes of spermatozoa were determined for 28 human ejaculates which were previously analyzed for semen volume, sperm concentration, morphology, motility, and fertility by in vitro fertilization procedures (IVF). Morphometric measurements of sperm heads were analyzed using a Zeiss Videoplan computer, while spermatozoan volume was determined with an Elzone particle analyzer. Though a strong relationship was anticipated, correlations between the volumetric data and different morphometric measures revealed poor, insignificant values. This lack of correspondence may be due to individual differences in the thickness of the spermatozoa within a sample. Twenty-two of the ejaculates used in this study were classified as fertile and six were infertile according to the IVF procedure results. Correlations between the morphometric measurements and the volume determinations in the fertile group were all positive. In contrast, those of the infertile group were all negative with one exception (width vs. volume).

Evluation of Acrosome on Papanicolaou-Stained Sperm and its Relationship to the in Vitro Fertilizing Capacity of Human Spermatozoa

Papanicolaou-stained sperm smears from 1150 ejaculates evaluated from infertility clinic patients and 166 ejaculates in an in vitro fertilization program were studied for the presence of acrosomal abnormalities. Morphologically, a normal acrosome was defined as a sperm having a ratio of 1:1 to 2:1 between the acrosome and postacrosomal part in an oval or round, uniformly shaped head. Acrosomal abnormality was identified in at least a few of the spermatozoa in all the ejaculates (range 8-98%) and appeared to be closely related to normal sperm morphology (r = 0.85). A significantly higher (p less than 0.01) correlation (r = 0.31) was noted between the presence of normal acrosome and in vitro fertilizing capacity of spermatozoa as compared to other standard semen characteristics. Acrosome can be identified on Papanicolaou-stained smears, and since it appears to be related to fertility it may be beneficial to evaluate the acrosome morphologically during routine semen analysis.