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Biomedical subjects

M L Windt

Publications and source records attributed to M L Windt.

26 records · Page 2Linked to original sources
PubMedDate not supplied

The hemizona assay (HZA) as an experimental model to evaluate the inhibition of sperm binding to the murine zona pellucida by isolated zona pellucida protein.

Compelling evidence has demonstrated that zona binding represents gamete recognition by sperm binding with high affinity and specificity to complex glycoproteins of the zona pellucida. In the present study we evaluated the hemizona assay (HZA) in the investigation of the interaction of mouse spermatozoa with unfertilized murine oocytes and hemizonae after exposure to solubilized murine zonae pellucidae proteins. The zonae pellucidae were isolated from ovarian tissue following described mincing techniques. The sperm binding characteristics of murine spermatozoa were studied by using SDS-PAGE isolated ZP2 (+/- 120 Kd) and ZP3 (+/- 83 Kd) components of the zona pellucida. Sperm receptor activity was examined in a competitive gamete binding fashion using the HZA as an indicator of sperm/zona interaction. The results illustrated that isolated, solubilized ZP2 and ZP3 glycoprotein moieties of the zona pellucida inhibited sperm binding to hemizonae and oocytes when compared to controls, and that the HZA can be utilized as an internally controlled homologous bioassay to evaluate the effects of zona pellucida proteins on tight binding of spermatozoa to the zona pellucida.

Animals↗
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Assisted reproductive technologies may obviate apparent immunologic infertility.

Spermatozoal autoantibodies have been associated with reduced fertilization by natural coital methods. Nine subfertile men were evaluated who repeatedly tested positive for spermatozoal autoantibodies as characterized by direct immunobead test. Using the hemizona assay, we determined whether tight binding of spermatozoa to the zona pellucida was reduced in these test males as compared to a fertile male whose semen had been cryopreserved and thawed immediately prior to testing. The average number of spermatozoa tightly bound to the zona pellucida from the subfertile male was significantly reduced compared to the fertile male (mean +/- SD, P less than or equal to 0.01) 19.5 +/- 8 versus 77.1 +/- 49. Seven of the nine couples eventually had successful fertilization using intrauterine insemination or gamete intrafallopian tube transfer and one couple conceived with natural coital insemination. Our findings, albeit limited, suggest that greater caution should be used in implicating associations of spermatozoal autoantibodies with absolute infertility, because novel assisted reproductive technologies often may obviate conventional encumbrances on opportunities for pregnancy.

Adult↗
PubMedDate not supplied

Analysis of human sperm membrane antigens reacting with sera from antisperm antibody positive and negative patients by western blotting.

Immunological infertility is thought to be caused by the binding of antibodies to 'fertility-related' antigen(s) on the sperm membrane. We compared antibody profiles in sera from 20 ASA(+) and ASA(-) men, using a sperm membrane extract as an antigen. Antigens were separated by SDS-PAGE under reducing conditions. The patients were classed as ASA(+) by the MAR (> 50%), d-IBT (> 20%) and TAT (> 1:64). The results showed that immunoreactive bands in both the ASA(+) and ASA(-) groups were heterogeneous and included bands covering the whole molecular weight range. Statistical analysis showed significantly more patients in the ASA(+) group having immunoreactive bands at molecular weights of 32 Kd (P = 0.006) and 79 Kd (P = 0.02) when compared to the ASA(-) group. In the ASA(-) group significantly more patients had reactive bands at 81 Kd (P = 0.01) when compared to the ASA(+) group. The 32 Kd antigen reacted only with sera from ASA(+) patients. We conclude that differences exist between the ASA(+) and ASA(-) groups when this extraction method is used and that the isolation and purification of the 32 Kd protein may justify further investigation.

Antibodies↗
PubMedDate not supplied

Sperm decondensation and semen parameters: utilization of a simple staining technique for the evaluation of human sperm decondensation.

The ability of spermatozoa to fertilize an oocyte depends on a sequence of events ending ultimately in the decondensation of the sperm chromatin on penetration of the oocyte. Knowledge of what percentage of sperm decondenses is useful, especially in patients where other functional tests and sperm quality fail to explain the reported poor in vitro fertilization (IVF) rates. The objective of this study was (1) to compare sperm decondensation induced by either SDS/EDTA or heparin with semen parameters (volume, concentration, motility and morphology), and (2) to evaluate the use of a simplified staining technique (Diff QuikR [DQ]) in comparison with the standard phase contrast method (Rose Bengal-[RB]). Randomly selected semen samples from 31 men attending an assisted reproductive programme were analysed for basic semen parameters and decondensation with SDS/EDTA and heparin. Two staining methods for the evaluation of decondensation were compared (phase contrast microscopy after Rose Bengal [RB] staining and light microscopy after Diff QuikR (DQ) staining). Moderate and grossly swollen sperm heads were recorded. Semen samples included both fertile and unfertile semen parameters. Sperm decondensation results showed poor to moderate correlations with semen parameters. The SDS/EDTA (DQ) (moderate forms) showed a significant negative correlation (r = -0.46) with seminal volume and a significant positive correlation (r = 0.41) with normal sperm morphology. The heparin (DQ) (moderate forms) decondensation showed a significant positive correlation with motility (r = 0.61) and sperm concentration (r = 0.43). The DQ method was preferred over the RB method due to its optical and storage advantage.(ABSTRACT TRUNCATED AT 250 WORDS)

Azure Stains↗
PubMedDate not supplied

In vitro fertilization failure: identification of gamete defects by investigation of sperm-zona pellucida binding capacity of unfertilized oocytes.

The objective of the study was to determine whether fertilization failure was due to spermatozoal or oocyte factors. Twenty-five unfertilized oocytes from 12 IVF/GIFT couples showing total or partial fertilization failure were evaluated for sperm zona binding potential under hemizonaeassay (HZA) conditions. Hemizonae were separately incubated with a sperm sample from the husband and that of a fertile control. Tight sperm binding to hemizonae was assessed. First, among the 12 patients, results showed a possible zona defect thought to be the cause of fertilization failure in five cases. Second, in two cases, fertilization failure was possibly caused by poor sperm binding potential of spermatozoa. Third, in two cases, fertilization failure was possibly caused by an oocyte defect, and fourth, three cases showed a mixture of possible causes. The results stress the need to develop a sequential analytic programme for those couples with repeated total or partial fertilization failure.

Adult↗
PubMedDate not supplied

Effect of sperm preincubation time on GIFT pregnancy outcome.

This investigation was conducted to evaluate the effect of human sperm preincubation time on the pregnancy outcome in gamete intrafallopian tube transfers. This was determined in a retrospective study on gamete intrafallopian transfer patients (ideopathic infertility) using logistic regression with the covariates, preincubation time (< or = 60 and > 60 min) and age (< or = 35 and > 35 years). The study included 485 consecutive gamete intrafallopian transfer cycles in which 3 metaphase II oocytes were transferred. Pregnancy outcome was evaluated by beta hCG levels on days 12 and 16 and was confirmed by the presence of a fetal heart 8 weeks after the procedure by means of sonography. The wife's age and sperm preincubation time were significant covariates in the prediction of ongoing pregnancy. The odds ratio for age (< or = 35 years) was 2.2 in the prediction of ongoing pregnancy, while the age-adjusted odds ratios for preincubation time (< or = 60 min) was 1.9. There was a critical relationship between sperm preincubation time and GIFT success, which confirms the effect of the wife's age on pregnancy. Close coordination is of importance between the clinical scientist and the physician to restrict the preincubation time to 1 h. The sperm preincubation time is a significant factor that has to be considered in the prediction of ongoing pregnancy in GIFT patients.

Adult↗
PubMedDate not supplied

Autosperm antibodies in treated, pregnant and non-pregnant immunologically infertile patients.

Twenty-two immunologically infertile couples (male partners had proven autosperm antibodies-positive mixed antiglobulin reaction test [MAR] and direct immunobead test [d-IBT]) were treated with washed spermatozoa used either in the gamete intrafallopian tube transfer (GIFT) or artificial insemination (AIH) procedures. Sixteen of the 22 couples (72.2%) fell pregnant with an ongoing pregnancy rate of 54.5% (12/22). The pregnant and non-pregnant groups were compared with regards to the sperm antibodies detected on the spermatozoa (MAR, d-IBT and sperm cervical mucus contact [SCMC] test) and in the serum and seminal plasma of the male partners (tray agglutination test [TAT], indirect immunobead test [i-IBT], and enzyme-linked immunosorbent assay [ELISA]). The semen parameters, motility, forward progression, count/ml and normal morphological forms were also compared. Statistical analysis showed no difference between the two groups (pregnant and non-pregnant) with regards to the antibody tests performed on semen, serum and seminal plasma. No difference was also seen between the semen parameters of the two groups. The washing of spermatozoa for the GIFT or AIH procedures may therefore be a successful method of treatment for immunologically infertile couples. The results also indicate no difference in the fertility prognosis for the two groups since antibody levels and semen quality were not different between the pregnant and nonpregnant group.

Antibodies, Anti-Idiotypic↗