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H H Van der Ven

Publications and source records attributed to H H Van der Ven.

At least 19 recordsLinked to original sources
PubMed1989

Semen quality and in-vitro fertilization.

The standard sperm parameters, and a newly developed assay, the hypoosmotic swelling (HOS) test, of 208 ejaculates were correlated with in vitro fertilization (IVF) outcome to assess their predictive value of the fertilizing capacity of spermatozoa. One hundred fifty-three (73.6%) of the ejaculates possessed spermatozoa that fertilized at least one oocyte and were considered fertile. Among the semen parameters studied, only the HOS test had a relatively high (r = 0.46, p less than 0.001) association with the fertilizing capacity of the spermatozoa. This test was also able to predict the outcome of IVF more reliably than the other semen parameters studied.

Female↗
PubMed1989

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).

Fertility↗
PubMed1987

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.

Female↗
PubMed1986

Evaluation 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.

Acrosome↗
PubMed1985

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.

Female↗
PubMed1985

Inhibition of human sperm penetration into zona-free hamster oocytes by proteinase inhibitors.

The potential role of serine proteinase in the penetration of human spermatozoa into denuded (zona-free) hamster oocytes was investigated. Aryl 4-guanidinobenzoates (10(-4) to 10(-6) M) and 4-aminobenzamidines (10(-3) and 10(-4) M) decreased oocyte penetration when present throughout the assay system. More detailed studies with 8-quinolyl 4-guanidinobenzoate showed that this inhibitor also caused a large decrease in the penetration rate even when only present during the preincubation period of the spermatozoa to induce capacitation. Much smaller decreases were observed when this inhibitor was only present during sperm/egg incubation. By contrast, 4-aminobenzamidine caused a large decrease in the penetration rate when present during sperm/egg incubation but a much smaller one when present during the sperm's preincubation period. The primary action of the inhibitors was not due to a visible effect on sperm motility or forward progression, or to an effect on the oocyte, although treatment of oocytes with inhibitor caused a small decrease in penetration. Inhibition of sperm binding to the oolemma occurred also at times, but this was not directly correlated to the decrease in oocyte penetration. The results are consistent with the fact that a serine proteinase, presumably acrosin, is important for the capacitation, acrosome reaction, and/or oocyte penetration of human spermatozoa. The synthesized aryl 4-guanidinobenzoates are of interest as contraceptive agents because they possess phenols approved by the Food and Drug Administration (United States) for human use and should be relatively nontoxic.

Animals↗
PubMed1984

Development of an assay to assess the functional integrity of the human sperm membrane and its relationship to other semen characteristics.

The objective of this study was to develop a relatively simple test to evaluate the functional integrity of the membranes of human spermatozoa. As in some other species, human spermatozoa 'swell' under hypo-osmotic conditions due to the influx of water and the expansion of the membranes. A mixture of equal parts of fructose and sodium citrate (150 mosmol) with calculated ionic strength of 0.15 resulted in a maximal number of clearly identifiable swollen spermatozoa. Only small variations were seen when different aliquants of the same semen samples were separately evaluated. A high correlation (r = 0.94) was obtained between expected and observed values of swollen spermatozoa when known amounts of heat-treated spermatozoa, unable to undergo swelling, were added to untreated spermatozoa. A good correlation (r = 0.90) was also observed between the % spermatozoa in a semen sample that were capable of undergoing swelling and the % of denuded hamster oocytes that were penetrated by capacitated spermatozoa from the same semen sample. By contrast, the correlations between % sperm swelling in ejaculates and % normal sperm forms, % motile spermatozoa and % spermatozoa that do not stain with eosin-Y (supravital stain) in the same ejaculates were 0.30, 0.61 and 0.52, respectively. Therefore, the hypoosmotic swelling technique to evaluate the functional integrity of the sperm membrane appears to give high repeatability and accuracy and is closely correlated to the in-vitro fertilizing ability of spermatozoa. It may be a useful addition to the standard semen analysis.

Cell Membrane↗
PubMed1983

Effect of heterologous seminal plasma on the fertilizing capacity of human spermatozoa as assessed by the zona-free hamster egg test.

The spermatozoa from 8 of 27 men showed a major increase (greater than 15%) in the oocyte penetration rate, the spermatozoa from 7 men showed a major decrease (less than 15%), and no major changes were noted in the other men when the spermatozoa were washed and preincubated with heterologous seminal plasma for 20 minutes before assessing their activity in the zona-free hamster egg assay. No difference was noted in motility or forward progression between the test and control spermatozoa. The increase or decrease in the oocyte penetration rate was consistent for all the ejaculates of a donor; i.e., a donor whose sperm showed an increase in the rate never showed a decrease, and vice versa. Additionally, the oocyte penetration rate of "epididymal-like" spermatozoa, obtained by ejaculation of the first fraction of a semen sample into a large volume of buffer, was enhanced when the spermatozoa were preincubated in their own seminal plasma, obtained from the other fraction of the ejaculate. It is concluded that seminal plasma can have a beneficial influence on the oocyte-penetrating capacity of spermatozoa that is independent of an effect on motility. However, the influence is probably often masked by the presence of antifertility factors in seminal plasma. The penetration-enhancing factor of seminal plasma has a molecular weight of less than 10,000, is quite heat-labile, but is stable at 4 degrees C. The penetration-enhancing factor is somewhat less stable at -20 degrees C and is unstable to lyophilization and reconstitution in H2O. Fertil Steril 40:512, 1983.

Animals↗
PubMed1983

Gossypol inhibition of acrosin and proacrosin, and oocyte penetration by human spermatozoa.

Gossypol, a known antispermatogenic agent, was found to effectively inhibit the highly purified boar sperm proacrosin-acrosin proteinase enzyme system by irreversibly preventing the autoproteolytic conversion of proacrosin to acrosin and reversibly inhibiting acrosin activity. The agent appears to prevent the self-catalyzed by not the acrosin-catalyzed activation of proacrosin. In additional experiments, brief exposure of human semen to concentrations of gossypol, which did not visibly alter spermatozoal motility or forward progression, was found to irreversibly inhibit the conversion of proacrosin to acrosin although the activity of the nonzymogen acrosin was not decreased, and also to prevent the human spermatozoa from penetrating denuded hamster oocytes. Gossypol inhibition of proacrosin conversion to acrosin closely paralleled the decline in oocyte penetration. Racemic (+/-) gossypol was equally as effective as the enantiomer (+) gossypol. The results suggest that the inhibition of proacrosin conversion to acrosin is a mechanism by which gossypol exerts its antifertility effect at nonspermicidal concentrations and that low levels of gossypol should be tested for their contraceptive action when placed vaginally.

Acrosin↗
PubMedDate not supplied

Comparison of glycerol and a zwitter ion buffer system as cryoprotective media for human spermatozoa. Effect on motility, penetration of zona-free hamster oocytes, and acrosin/proacrosin.

This study compared the cryoprotective effect of glycerol with that of a zwitter ion buffer system (TESTCY). Spermatozoa that are cryopreserved in the presence of glycerol possess a somewhat higher progressive motility immediately after thawing than those preserved in the presence of TESTCY. However, after a 1-hour incubation in glycerol-free medium, the progressive motilities of the glycerol- and TESTCY-treated spermatozoa become essentially identical. After 2 hours in culture medium, TESTCY-treated spermatozoa possess a higher motility than glycerol-treated spermatozoa, indicating that TESTCY is a better preservative than glycerol for the long-term motility of human spermatozoa. The fertilizing potential of the cryopreserved spermatozoa was assessed by their ability to penetrate zona-free hamster oocytes in vitro. Spermatozoa that are cryopreserved in the presence of TESTCY produce three- to four-fold higher penetration rates than glycerol-treated, cryopreserved spermatozoa. Cryopreservation in the presence of TESTCY also results in a higher stability of the acrosin/proacrosin system than when the spermatozoa are preserved in glycerol, since about two- to three-fold higher levels of proacrosin are retained. These results indicate that TESTCY is a better cryopreservative for human spermatozoa than glycerol.

Acrosin↗
PubMedDate not supplied

Correlation between human sperm swelling in hypoosmotic medium (hypoosmotic swelling test) and in vitro fertilization.

Human ejaculates (n = 83) were analyzed for standard sperm parameters (concentration, motility, and morphology), as well as for the ability of the spermatozoa to react (swell) in a hypoosmotic medium (Jeyendran et al, 1984). Subsequently, the fertilizing capacity of the spermatozoa was tested by their ability to fertilize human oocytes in vitro. Although the sperm concentration was adjusted for in vitro fertilization, no adjustments were made for sperm motility and morphology. Correlation of the in vitro fertilizing capacity of the spermatozoa with the hypoosmotic swelling test (r = 0.56) was much higher than with standard sperm parameters (r varied from -0.04 to 0.25). Complete overlap was noted with standard semen parameters whether the ejaculate did or did not fertilize oocytes and ranged from very low to very high values in both cases. By contrast, all the semen samples that fertilized oocytes showed a 60% or higher reaction in the hypoosmotic swelling test, whereas the majority of the "infertile" semen samples showed less than 60% swelling. It therefore appears that, under the conditions of our studies, the hypoosmotic swelling test is a more accurate predictor of successful in vitro fertilization outcome than the conventional semen parameters. A combination of all parameters, however, is likely to be most useful. The hypoosmotic swelling test is simple and economical, and it is recommended that this test be further scrutinized for its value as an additional tool in the assessment of the in vivo fertilizing capacity of ejaculated spermatozoa.

Cell Survival↗
PubMedDate not supplied

A simple, clinical assay to evaluate the acrosin activity of human spermatozoa.

Acrosin, a sperm-specific acrosomal proteinase, has an essential role in the fertilization process. Low levels of acrosin appear to be associated with subfertility and infertility, and the acrosin activity of spermatozoa may potentially be a useful indicator of semen quality. The standard acrosin tests employed by research laboratories are too complicated and/or time consuming for clinical use; therefore, a simple assay has been developed to assess total acrosin activity (acrosin and activatable proacrosin). To perform the test, liquefied semen is centrifuged over Ficoll, the washed sperm pellet is suspended in a detergent (Triton X-100)-substrate (N-alpha-benzoyl-DL-arginine p-nitroanilide) buffer, pH. 8.0, and the amidase activity is determined spectrophotometrically after a 3-hour incubation period. Amidase activity can be inhibited with benzamidine, indicating that the activity is primarily or entirely due to acrosin. The absence of detergent in the incubation medium results in greatly reduced activity. The assay is repeatable, linear with increasing sperm concentration, sensitive to a lower limit of 2 x 10(6) spermatozoa, and the results correspond to those obtained with a standard acrosin extraction and assay technique. Storage of ejaculates at 3 to 6 C or at 22 to 24 C for 24 hours does not affect the acrosin activity significantly but much higher temperatures can cause a loss of activity. Freezing ejaculates results in a large decrease in sperm acrosin activity. Leukocytes show minimal activity in the assay. Sperm populations prepared by a swim-up procedure average approximately a 2-fold higher acrosin activity than the original ejaculates. Preliminary experiments indicate that the average sperm acrosin activity of ejaculates whose spermatozoa successfully fertilize human eggs in vitro is significantly higher than those that do not fertilize eggs.

Acrosin↗
PubMedDate not supplied

Acrosomeless sperm. A cause of primary male infertility.

Sperm without acrosome of two males--spouses of infertile marriages--were studied. No acrosome could be identified in the Papanicolaou stained smears of either patient. Electron microscopy study confirmed the absence of acrosome and post-acrosomal sheath. The physical and functional integrity of the sperm membrane was determined by vital staining technique (72% unstained) and hypoosmotic stress test (69% swollen). Acrosin assay showed a five-fold decrease, and proacrosin values were almost eight-fold lower than the normal values. Nonzymogen acrosin level was normal. Zone-free hamster oocytes were not penetrated by the acrosomeless sperm showing 46% progressive motility, but postcoital tests in both female spouses showed active sperm. The results would indicate that the sperm devoid of acrosome may be considered as a primary cause of male infertility.

Acrosin↗
PubMedDate not supplied

Effect of glycerol and cryopreservation on oocyte penetration by human spermatozoa.

A poor penetration rate of glycerol-treated, cryopreserved human spermatozoa as compared to untreated fresh control, was observed in the zona-free hamster oocyte test. Similarly, glycerol treatment of freshly ejaculated spermatozoa depressed the penetration rate unless the culture medium also contained glycerol. Immediately after thawing, glycerol-treated, cryopreserved spermatozoa possessed adequate progressive motility, but their incubation in glycerol-free culture medium caused a severe reduction in motility. Even if the same number of progressively motile, cryopreserved, glycerol-treated spermatozoa as unfrozen spermatozoa were added to the eggs, a much lower penetration rate was obtained by the treated spermatozoa. It is concluded that spermatozoa develop a glycerol dependence and that removal of glycerol from the surrounding medium, as most likely occurs when spermatozoa pass through the cervix, reduces both the motility and the ability of spermatozoa to become capacitated and fuse with oocytes. Thus, glycerol is not an optimal cryopreservative agent. Further, the decreased oocyte penetration rate of glycerol-treated, cryopreserved spermatozoa is due to other factors besides the decrease in sperm motility.

Animals↗
PubMedDate not supplied

Volumetric analysis of human spermatozoa.

In 29 semen samples of men participating in an in vitro fertilization (IVF)-program the spermatozoan volume was determined on an electronic particle analyzer and a routine semen analysis was performed including the estimation of semen volume, sperm concentration, motility and morphology. Twenty three of the 29 semen samples were able to fertilize human oocytes in the IVF-procedure. There was no statistically significant difference noted between the spermatozoan volume of the fertile (16.25 +/- 0.43 cu microns) and the infertile samples (16.9 +/- 0.57 cu microns). Logistic regression analysis indicated that spermatozoan volume was not a significant predictor of fertility. Furthermore, none of the standard sperm parameters appear to be closely related to the mean spermatozoan volume.

Fertilization↗
PubMedDate not supplied

The hypoosmotic swelling test: an update.

The hypoosmotic swelling (HOS) test is a relatively new assay used to evaluate the functional integrity of the sperm's plasma membrane. In fact, more studies have been published on the applicability of the HOS test than any other new sperm indicator. The assay is based on the fact that fluid transport occurs across an intact cell membrane under hypoosmotic conditions until equilibrium is reached. Due to the influx of fluid, the cell will expand and bulge, especially in the tail, and this change can be readily observed with a phase contrast microscope. Earlier studies have yielded some confusion regarding the interpretation of the data. This review is an attempt to clarify and update the usefulness of the HOS test as a tool to evaluate the sperm function.

Animals↗
PubMedDate not supplied

Chemical constituents of human seminal plasma: relationship to fertility.

Eighteen different chemical constituents of seminal plasma from 52 patients in an in vitro fertilization (IVF) program were quantitated. The ejaculates were divided into "fertile" and "infertile" groups depending on whether the spermatozoa did or did not fertilize oocytes. Glycerylphosphorylcholine showed a significant difference between the two groups and was also significantly correlated with fertility, suggesting that GPC may influence the fertilizing ability of the spermatozoa. No such differences/correlations were found for the other constituents although a number of these components were lowest in the "infertile" group. In no case was the correlations between a seminal constituents and fertilization high enough to predict whether an ejaculate is fertile or infertile.

Female↗