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Biomedical subjects

R Menkveld

Publications and source records attributed to R Menkveld.

64 records · Page 4Linked to original sources
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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

Effects of different staining and washing procedures on the results of human sperm morphology evaluation by manual and computerised methods.

The purpose of this study was to investigate the effect of different staining and washing procedures on the results of human sperm morphology evaluation by manual and computerised methods. Furthermore, it was intended to find the staining and washing combination which would provide optimal readability for computer-assisted sperm morphology evaluations. In phase one, four staining methods were evaluated for smears prepared from the resulting samples following a two times washing procedure. In phase two, 20 semen samples were used to compare the Diff-Quik and Papanicolaou staining methods, following one and two washes. All manual readings, of Papanicolaou and Diff-Quik stained smears, were comparable with each other, with means between 7.3% and 7.9% normal spermatozoa. All the manual readings were also comparable to the computer readings of the Diff-Quik slides following one and two washes with means of 9.0% and 5.9%, respectively. However, due to the higher computer readings found for the Papanicolaou stained smears, with means of 13.9% and 13.5% following one and two washes, respectively, a statistically significantly difference between overall computer and manual readings was found (Wilks' Lamda, P = 0.0002). Taking all data into consideration, it could be concluded that the one wash Diff-Quik stained smears was the optimal preparation method for computerised sperm morphology evaluation, comparing favourably with manual evaluations.

Evaluation Studies as Topic↗
PubMedDate not supplied

Effect of ethanol on semen characteristics of vervet monkeys.

The effect of alcohol on spermatogenesis and sperm morphology has been of interest to many andrologists. Six adult male vervet monkeys were utilized to evaluate the effect of ethanol on semen quality. A decrease of the percentage of normal spermatozoa was observed after 10 months of exposure to alcohol.

Animals↗
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Effect of lead and organophosphates on sperm morphology.

Lead and organophosphates can exert a toxic action on the male reproductive function. A cross-sectional study involving 40 men was undertaken to investigate the effect of these toxins on sperm morphology. Based on the percentage of morphologically normal spermatozoa, subjects were divided into two groups. The control group (sperm morphology greater than or equal to 20% normal forms) consisted of 18 patients, and the study group (sperm morphology less than 5% normal forms) consisted of 22 patients. Lead, pseudocholinesterase, dibucaine, and fluoride levels were measured in blood samples of these men. The 22 men with low morphologically normal forms (less than 5%) did not display significantly different levels of the abovementioned substances compared to the control group.

Butyrylcholinesterase↗
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Significance of antisperm antibodies in female serum in a gamete intrafallopian transfer program.

The influence of antisperm antibodies in the female serum on fertilization and pregnancy rate in patients undergoing GIFT was assessed. A study group of 52 couples (69 cycles) with significant levels of antisperm antibodies in the female serum were compared to a control group of 749 couples (1185 cycles). Maternal serum or donor serum was used as growth medium supplement. The TAT test was performed for the detection of antisperm antibodies in the serum. Antisperm-antibody presence in female serum was associated with similar fertilization and pregnancy rates in a GIFT program compared to the control group. The type of serum used as growth medium supplement did not affect statistically the fertilization or pregnancy rate.

Adult↗
PubMedDate not supplied

Multicenter study on reproducibility of sperm morphology assessments.

Sperm morphology has always been considered an important tool in evaluating a man's fertilizing potential. The objective of this multicentric study was to evaluate intra- and interindividual variability and between-laboratory variation using the same or different criteria of sperm morphology assessment. Semen samples were obtained from 20 males and 32 smears were made of all samples. Eighty coded smears (4 per patient) were sent to 8 laboratories for morphology assessment. The centers applied different classification systems (strict criteria, WHO 1987, Düsseldorf criteria) and participants were asked to analyze the 80 smears twice, with an interval of 1 week between each participant's two analyses. Intraclass correlations between repeats showed that sperm morphology can be assessed with acceptable within observer reproducibility. Expected increases in imprecision were observed up to coefficients of variation of >30% with decreasing morphology scores, regardless of the classification system used. Agreement in correct classification of samples as normal/abnormal was obtained in 80% of cases. Differences in reproducibility between slides may reflect an important source of heterogeneity due to smear preparation. These results emphasize the importance of external quality control systems to improve the value of sperm morphology assessments in the investigation of the male partner in a subfertile couple.

Fertilization in Vitro↗
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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↗
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Comparative analysis of in vitro fertilization methods for establishing successful embryo transfer clinics.

A review of the laboratory methods and embryo transfer procedures used by seven of the foremost clinics in the world are discussed and evaluated in this article. Based on these facts an in vitro fertilization clinic was launched in 1983. In the second part of the paper the latest laboratory methods, i.e. ovulation induction plans and the embryo transfer technique of Tygerberg Hospital, are described. One hundred and thirty laparoscopies were performed since 1 May 1984-30 November 1984. Six hundred and one follicles were aspirated, 482 oocytes were obtained, 84% of all oocytes were fertilized, 112 patients reached the transfer stage and 28 pregnancies resulted. A clinical pregnancy rate of 21,4% per transfer and 18,5% per laparoscopy resulted.

Blood↗
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The technique for human embryo transfer at Tygerberg Hospital.

From 1 May 1984 to 30 April 1985 177 laparoscopies were performed; 684 oocytes were obtained and a fertilization rate of 85% per oocyte achieved. There was a pregnancy rate of 24.3% per embryo transfer (ET) and 20.9% per laparoscopy after 152 patients were subjected to ET. The ET technique at Tygerberg Hospital, using the Tomcat catheter, is described. An introducer--the FT introducer--designed to overcome technical difficulties in selected patients in passing the Tomcat catheter is described. Technical problems are easily overcome with this introducer. In 26 patients (17.1%) ET was performed using this instrument and 8 pregnancies resulted (a pregnancy rate of 30.7% per ET). This pregnancy rate indicates the value of the instrument.

Adult↗