Biomedical subjects

K Coetzee

Publications and source records attributed to K Coetzee.

34 records · Page 2Linked to original sources

PubMed1990

A rapid stain for the diagnosis of granuloma inguinale.

Tissue smears were prepared from 55 men and eight women with genital ulceration using two staining techniques and examined by direct microscopy for the presence of Donovan bodies. Twenty three smears were positive using the May-Grunwald-Giemsa staining method and 23 were positive using a rapid technique, the RapiDiff stain. The RapiDiff technique is suitable for use in the diagnosis of granuloma inguinale (donovanosis) in busy sexually transmitted diseases clinics in the developing world.

Female↗

PubMed1989

Hypoosmotic swelling test in the prediction of male fertility.

The hypoosmotic swelling test (HOS) is a simple test to measure the functional competence of human sperm membranes. The question is, does a relationship exist between this competence and the fertilization potential of human spermatozoa? In this study the strongest correlation (r = 0.76) was obtained between sperm swelling and sperm viability (supravital staining). Only a moderate correlation (r = 0.50) was obtained with normal sperm morphology; weaker correlations were also obtained with the sperm penetration assay (r = 0.42) and human IVF (r = 0.24). The results, therefore, indicate that the HOS test has a limited predictive value. Notwithstanding this low concordance between sperm swelling and fertilizing potential, a less than 50% HOS test threshold was seen to be a definite indicator of a male factor.

Cell Survival↗

PubMed1989

Usefulness of sperm penetration assay in fertility predictions.

The competence of the sperm penetration assay (SPA) to predict male fertility, as determined by normal sperm morphology and the fertilizing potential, as shown by human in vitro fertilization (IVF), was investigated. A significant correlation was obtained between normal sperm morphology and the SPA (phi = 0.623). A weaker correlation was however obtained with human IVF (phi = 0.397). Notwithstanding this weak association, a positive SPA (greater than 10%) was highly predictive (95%) of human IVF success. In contrast, a negative SPA (less than or equal to 10%) was associated with a high rate of false-negatives (65%). The SPA does however warn that a male factor may be present, as the mean fertilization rate of this group of patients was markedly reduced. The preincubation period for the spermatozoa did not play a major role in the predictive ability of a SPA outcome.

Female↗

PubMed1978

The efficiency of a drinking fountain.

In this experiment the efficiency of a water drinking fountain was studied. Efficiency was defined in terms of the percentage of water actually consumed in relation to the water that flows from the drinking fountain, the drinking time, the water consumed per user and the electricity required to cool the water. For this purpose four different spout diameters were used and the water pressure was regulated to give two different water trajectory heights for each spout diameter setting. This resulted in eight different flow rates. The results of the study indicated that the water fountain is a highly inefficient water transfer mechanism and that extreme flow rates worsened the efficiency of the system. The intermediate spout nozzle diameters proved to be superior with regard to all the efficiency statistics.

Journal Article↗

PubMedDate not supplied

Validation of a new disposable counting chamber.

In a routine prospective study, 3 different counting chambers were compared for manual and computer-assisted evaluations. Swim-up samples were used so as to remove all debris and other cells that may contaminate the evaluation process when using a semen analyzer. The Makler concentration determinations (n = 20) were, on average. approximately 20 x 10(6) cells/mL higher compared to the corresponding 20 hemocytometer counts. The mean differences between the Leja chambers and the hemocytometer counts (n = 320) were only around 1 x 10(6) cells/mL, with coefficients of variation around 20%. The Leja chambers for both manual and the computer-assisted sperm concentration determinations provided consistent and accurate data on sperm concentration.

Humans↗

PubMedDate not supplied

Predictive value of normal sperm morphology: a structured literature review.

The aim of the study was to conduct a structured review of the literature published on the use of normal sperm morphology, as an indicator of male fertility potential in the in-vitro fertilization (IVF) situation, and to establish the universal predictive value of this semen parameter. Published literature in which normal sperm morphology was used to predict fertilization and pregnancy, during the period 1978-1996, was reviewed. A total of 216 articles were identified by the sourcing methodology, but only 49 provided data that could be tabulated and analysed. Of these, only 18 provided sufficient data for statistical analysis. Fifteen studies used the strict criteria to evaluate sperm morphology, two used World Health Organization (WHO) guidelines and one used both the strict criteria and the WHO guidelines. All the studies (n = 10) using the 5 and 14% normal sperm morphology thresholds (strict criteria) produced positive predictive values for IVF success. In the prediction of pregnancy, 82% (9/11) and 75% (6/8) of the studies produced positive predictive values when using the 5% and 14% thresholds respectively. Aggregating the data produced around the 5% normal sperm morphology threshold (strict criteria), the overall fertilization rates were 59.3% (1979/3337; per oocyte) for the < or = 4% group and 77.6% (10345/13327; per oocyte) for the >4% group, and the overall pregnancy rates were 15.2% (60/395; per cycle) and 26.0% (355/1368; per cycle) respectively. The no-transfer rates across the 5% threshold were 24.0% (86/359; per cycle) in the < or = 4% group compared to 7.4% (80/1088; per cycle) in the >4% group. The inclusion of an accurately evaluated normal sperm morphology count as an integral part of the standard semen analysis makes this analysis still the most cost-effective means of evaluating the male factor.

Confidence Intervals↗

PubMedDate not supplied

The role of sperm morphology in assisted reproduction.

This article attempts to evaluate the value of sperm morphology in assisted reproduction by summarizing a recent structured literature review covering the topic. New developments in the field of sperm morphology with emphasis on computer evaluation of morphology and its latest clinical application are highlighted, as well as the correlation between sperm functional tests and sperm morphology. Based on the correlation between the sperm functional tests and sperm morphology, as well as the latter's proven value as a predictor in in-vitro fertilization, one can assume that sperm morphology reflects function, although based on definition it is not a sperm functional test per se. The evaluation of sperm morphology by strict criteria is a simple, cost-effective method and can be used to guide the clinician and scientist on a day-to-day basis to make sound clinical decisions.

Female↗

PubMedDate not supplied

Effect of multiple centrifugations on the evaluation of the acrosome reaction in human spermatozoa.

This study was undertaken to assess the effect of multiple centrifugations on the human acrosome reaction and in vitro fertilizing ability. Semen samples were obtained from sperm donors and from patients participating in our in vitro fertilization programme. Measured sperm samples were centrifuged twice (400xg for 5 min) before or after the induction of the acrosome reaction with calcium ionophore A23187 and before the insemination of oocytes. The samples obtained from the sperm donors were used to measure the acrosomal loss by means of indirect immunofluorescence (T6 monoclonal antibody) and the patient samples were used to assess fertilizing ability and cleavage. Samples centrifuged twice before the chemical induction of the acrosome reaction exhibited significantly elevated levels of acrosomal loss (mean = 46%) as compared to the controls (23%). However, the fertilization (P = 0.688) and cleavage (P = 0.187) rates were not significantly different between the controls and the centrifuged samples. The present study has shown that the centrifugation of motility enriched (swim-up) samples may also modify the acrosomal membrane complex, without compromising fertilizing potential.

Acrosome↗

PubMedDate not supplied

Glass wool filter preparation of cryopreserved spermatozoa.

Oligozoospermic and asthenozoospermic semen ejaculates, as well as cryopreserved sperm samples prepared by the wash and swim-up procedure often result in unsatisfactory sperm recovery rates. In this study the glass wool filter and the wash and swim-up preparation procedures were compared on the basis of their 'effective' (number of live sperm per millilitre) recovery rates. The glass wool filter procedure consistently produced significantly (P = 0.0002) higher viable sperm concentrations, making it the preferred method for the preparation of cryopreserved sperm to be used in assisted reproduction techniques. The use of this preparation procedure has also been shown to have no adverse affect on the fertilizing potential of human spermatozoa in our unit.

Cryopreservation↗

PubMedDate not supplied

Sperm-oocyte interaction: studies on the kinetics of zona pellucida binding and acrosome reaction of human spermatozoa.

Successful sperm-oocyte interaction depends, among other things, on sperm capacitation, which is defined by acrosomal and motility alterations. In the study described here the authors evaluated different aspects of this gamete interaction in humans. Specifically, the authors studied (1) the relationship between the number of spermatozoa bound to the zona pellucida and sperm concentration and incubation period, (2) the capacitation status and kinetics of acrosome reaction among the zona-bound spermatozoa, and (3) the effect of human follicular fluid on the zona-binding potential and acrosome status of spermatozoa from different men. The results indicated a concentration of 10(7) cells ml-1 after 15 min of coincubation to be the optimum for zona binding. The number of sperm bound after 0, 3 and 5 h of incubation was the same. In addition, spermatozoa incubated for 3 or 5 h underwent the acrosome reaction (range 9-43%) on the zona surface within 15 min of binding. The maximum percentage of acrosome-reacted spermatozoa was reached after 60 min of binding. Follicular fluid affected the sperm populations selectively, since it did not influence zona binding capacity in all cases. The data enhances the authors' understanding of critical events occurring before fertilization.

Acrosome↗

PubMedDate not supplied

Comparison of two staining and evaluation methods used for computerized human sperm morphology evaluations.

The purpose of the study was to analyse the agreement between computer analysed (Hamilton Thorne, IVOS Dimensions Version 3) normal sperm morphology and values obtained from 97 slides stained according to the Papanicolaou and Diff-Quik method. Liquefied semen samples were washed once by centrifugation and air dried smears on slides were made, which were stained according to the Papanicolaou and Diff-Quik method and analysed by computer. The paired t-test was used to assess whether any bias existed between the two methods. The limits of agreement were calculated using the Bland and Altman approach and a modification of this approach (mean-dependent limits). A significant bias of 1.6% was obtained in favour of higher normal sperm morphology percentages when using the Diff-Quik method. The standard limits of agreement were -13.4% to 16.6%, whereas the mean-dependent limits of agreement were 1.6% [5.8 + 0.6 (mean percentage normal morphology)]. Statistically, the Diff-Quik and Papanicolaou staining methods produce different normal sperm morphology profiles. These inherent differences may, therefore, require the establishment of new normal sperm morphology thresholds for male fertility, based on clinical data, when using the Diff-Quik staining method in conjunction with computerized analysis.

Azure Stains↗

PubMedDate not supplied

Comparison of motility characteristics and normal sperm morphology of human semen samples separated by percoll density gradient centrifugation.

The aim of this study was twofold: to investigate the ability of Percoll gradient centrifugation (52, 68, 84%) to fractionate semen samples according to motility quality and percentage normal morphology and to determine whether there is an association between sperm motility quality and percentage normal morphology. Sperm motility was evaluated using a Hamilton Thorn analyzer and normal sperm morphology was manually assessed according to the strict criteria (< or = 4, 5-14, and >14%). The majority of motility parameters and the percentage normal morphology were found to be significantly improved in the 84% Percoll fraction. The greatest effect was on the < or = 4% group, shifting the mean normal morphology percentage from 2.6 to 5.2%. Curvilinear velocity (VCL) and average path velocity (VAP) were the only two motility parameters that were significantly associated with the percentage normal morphology. Using a combined VCL, VAP vector the >14% group was found to have a significantly different value as compared to the 5-14 and < or = 4% groups. Percoll (discontinuous) gradient centrifugation can therefore play a significant role in the improvement of semen samples for use in assisted reproduction procedures. The VCL, VAP vector identified may also serve as an additional tool in the prediction of the fertility potential of sperm samples.

Analysis of Variance↗

PubMedDate not supplied

Slide preparation and staining procedures for reliable results using computerized morphology.

The purpose of this study was to standardize slide preparation and staining procedures to improve the efficiency and effectivity of the IVOS system on normal sperm morphology readings with regard to the strict criteria. Semen samples from patients attending the Reproductive Biology Unit, Tygerberg Hospital, were used. In experiment 1, five different Diff-Quik staining procedures, including the standard procedure, were evaluated on each of 22 patients and the effect of slide preparation within 1 h or more than 5 h after collection and the effect of immediate fixation versus fixation after 24 h were observed. In experiment 2, the manual evaluation time per slide (n = 20) by two technicians was compared with the time taken by computer. In experiment 1 the median % normal for the 5 different staining procedures was 6, 6.5, 9.5, 8.5, and 5.5%. No significant difference was found between the different staining procedures (p = .60, nonparametric Friedman test). In experiment 2 the mean time for manual assessment by two technicians was 3 min:6 s and 3 min:53 s per slide as compared to 4 min:39 s by computer. For experiment 1, slides can be prepared immediately or after 5 h. Fixation time also does not interfere with the computer's ability to identify normal forms. For experiment 2, the IVOS system is competitive regarding assessment time. Standardization of optimum staining procedures is important to ensure repeatability and comparability. Therefore, slides should be prepared immediately after liquefaction and fixed immediately after air drying.

Evaluation Studies as Topic↗

PubMedDate not supplied

Comparison between swim-up and glass wool column filtration of human semen in a gamete intrafallopian transfer program.

This study compared swim-up and glass wool filtration in both pregnancy outcome and fertilization of excess oocytes in patients undergoing gamete intrafallopian transfer. Gamete intrafallopian transfer patients were retrospectively included in the study group (n = 52). The criteria for inclusion were as follows: Semen had to have been prepared by means of glass wool filtration and at least 2 metaphase II oocytes had to have been transferred. Each patient from this group was then carefully matched with another patient according to specific criteria (number of metaphase II oocytes aspirated and transferred, normal sperm morphology, wife's age, the absence of anti-sperm antibodies, semen preparation by means of the swim-up procedure). Fourteen patients were matched with themselves (groups A1 and A2) and 38 patients were matched with another patient (groups B and C). The results indicate that there was no significant difference in the fertilization and pregnancy probabilities of sperm prepared by means of glass wool filtration or swim-up procedure. The comparative pregnancy rates for the groups were A1 (7.1%) versus A2 (7.1%) and B (28.9%) versus C (31.6%). Factors other than fertilization and pregnancy potential may have a greater influence on choosing the optimum sperm preparation procedure.

Female↗

PubMedDate not supplied

Prognostic value of the strict criteria: an Argentinian experience.

The prognostic value of normal sperm morphology, evaluated according to the strict criteria, was prospectively assessed. The study included 112 IVF cycles. The percentage normal sperm morphology of the semen samples used in each cycle was determined and assigned to one of three prognostic groups; P-pattern (< 4% normal forms), G-pattern (5-8% normal forms), and N-pattern (> 8% normal forms). The fertilization, grade 4 embryo attainment, and pregnancy rates were compared between the three groups. The fertilization rate of the N-pattern group (83.7%) was significantly higher than that of the G-pattern (59.65%) and the P-pattern (22.58%) groups. The grade 4 embryo attainment rate was only significantly different between the N-pattern (23.38%) and the P-pattern (4.76%) groups. No pregnancy was obtained in the P-pattern group compared to a pregnancy rate per transfer of 23.08% in the N-pattern group. This study reaffirms the interlaboratory reproducibility and the prognostic value of normal sperm morphology.

Argentina↗

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↗