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Biomedical subjects

F Schoonjans

Publications and source records attributed to F Schoonjans.

At least 19 recordsLinked to original sources
PubMed2005

Combined conventional/antioxidant "Astaxanthin" treatment for male infertility: a double blind, randomized trial.

AIM: To evaluate the treatment of male infertility with a strong natural antioxidant, in addition to conventional treatment. METHODS: Using a double blind, randomized trial design, 30 men with infertility of > or =2 months and female partners with no demonstrable cause of infertility received conventional treatment according to the guidelines of the World Health Organization (WHO), and either a strong antioxidant Astaxanthin 16 mg/day (AstaCarox, AstaReal AB, Gustavsberg, Sweden) or placebo for 3 months. The effects of treatment on semen parameters, reactive oxygen species (ROS), zona-free hamster oocyte test, serum hormones including testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH) and Inhibin B, and spontaneous or intrauterine insemination (IUI)-induced pregnancies were evaluated. RESULTS: ROS and Inhibin B decreased significantly and sperm linear velocity increased in the Astaxanthin group (n = 11), but not in the placebo group (n = 19). The results of the zona-free hamster oocyte test tended to improve in the Astaxanthin group in contrast with the placebo group, though not reaching statistical significance. The total and per cycle pregnancy rates among the placebo cases (10.5 % and 3.6 %) were lower compared with 54.5 % and 23.1 % respectively in the Astaxanthin group (P = 0.028; P = 0.036). CONCLUSION: Although the present study suggests a positive effect of Astaxanthin on sperm parameters and fertility, the results need to be confirmed in a larger trial before recommending Astaxanthin for the complementary treatment of infertile men.

Adult↗
PubMed1998

The Multi Unit Activity analyzer: a Windows based hardware-software system for low cost, high speed analog to digital data conversion, data acquisition and window discrimination.

The Multi Unit Activity analyzer is a hardware-software package for multi-purpose, two-channel data acquisition, with a computer dependent maximal digitizing frequency selectable from 1 to 27,000 s(-1) on both channels simultaneously. The hardware is connected to an IBM compatible PC through one of the serial ports (standard RS 232 interface). Software was developed to view digitized signals and record or read them on or from the harddisk. The program can also perform amplitude based window discrimination on the raw signal, on-line or during replay. The system is used for recording and analyzing multi unit activity from neuronal tissue in our electrophysiology lab but it can be applied in a variety of other settings. Basic programming routines are available that allow customized data acquisition.

Analog-Digital Conversion↗
PubMed1998

The fatty acid composition of phospholipids of spermatozoa from infertile patients.

The lipid composition of the sperm membrane has a significant effect upon the functional characteristics of spermatozoa. In the present study we investigated the fatty acid (FA) composition of subpopulations of spermatozoa separated on a discontinuous Percoll gradient (47:90%) and the FA composition of phospholipids (PL) of sperm heads and tails in both normal and abnormal semen samples. In normozoospermic samples, polyunsaturated fatty acids (PUFA) represented 34.0 +/- 1.3 (mean +/- SE, mole %) and 25.6 +/- 1.2% of total FA of PL of the 47 and 90% Percoll fractions respectively. Docosahexaenoic acid (22:6omega3, DHA) contributed to more than 60% of total PUFA. DHA was significantly lower in both the 47% (P < 0.05) and the 90% (P < 0.01) Percoll fractions of oligozoospermic samples and in the 90% Percoll layer of asthenozoospermic samples (P < 0.01), compared with normozoospermic samples. The omega6/omega3 ratio was significantly increased in both Percoll fractions of samples with oligozoospermia (47%, P < 0.001 and 90%, P < 0.001) or with asthenozoospermia (47%, P < 0.05 and 90%, P < 0.001) compared with normozoospermic samples. The oxidative potential index (OPI) of spermatozoa recovered from the 47% Percoll layer was significantly higher (P < 0.0001) than of those recovered from the 90% Percoll. Mean melting point (MMP), an index of membrane fluidity, was significantly lower in head than in tails (P < 0.01) of spermatozoa, and also in both the 47% (P < 0.01) and 90% (P < 0.001) Percoll fractions of normozoospermic samples in comparison with oligozoospermic samples. The MMP was significantly higher (P < 0.05) in samples of patients with idiopathic oligo/asthenozoospermia, varicocele, and male accessory gland infection (MAGI). These differences in FA composition of PL in subpopulations of human spermatozoa, and in their heads and tails may be related to sperm maturity and to differences in physiological function.

Epididymitis↗
PubMed1998

White blood cells cause oxidative damage to the fatty acid composition of phospholipids of human spermatozoa.

The lipid composition of the sperm membrane has been shown to exert a significant effect upon the functional quality of spermatozoa. We have studied the effect of induced peroxidation and of the presence of polymorphonuclear white blood cells (WBCs) on the fatty acid composition of the phospholipids of human spermatozoa. The spermatozoa were fractionated by a discontinuous Percoll gradient in two fractions (47% and 90% Percoll). Induced peroxidation of spermatozoa was assessed by determining the production of thiobarbituric acid reactive substances (TBARS), mostly malondialdehyde, after incubation with ferrous sulphate and sodium ascorbate as a promoter of peroxidation. TBARS production after induction of peroxidation was correlated with the abundance of polyunsaturated fatty acids (PUFA)(r = 0.68, p < 0.0001), with the double bond index (r = 0.72, p < 0.0001), and with the oxidative potential index (r = 0.73, p < 0.0001) of fatty acids of phospholipids. In comparison with samples containing > 1 x 10(6) WBCs/mL, those with < 1 x 10(6) WBCs/mL contained higher proportions of PUFA (90% Percoll, p < 0.05; 47% Percoll, p < 0.05), total omega 3 fatty acids (90% Percoll, p < 0.05; 47% Percoll, p < 0.001), docosahexaenoic acid (90% Percoll p < 0.05; 47% Percoll, p < 0.05), and double bond index (90% Percoll, p < 0.05; 47% Percoll, p < 0.001). In addition, mean melting point was significantly lower (90% Percoll, p < 0.05; 47% Percoll, p < 0.001) in samples with < 1 x 10(6) WBCs, indicating higher membrane fluidity. The increase of TBARS production by spermatozoa after incubation with the xanthine-xanthine oxidase system and/or ferrous sulphate as promoter of peroxidation was associated with a significant decrease of PUFA. Incubation of spermatozoa with WBCs, with or without activation by phorbol ester, decreased the PUFA (p < 0.05). Also, TBARS production was increased (p < 0.01) after activation of WBCs with phorbol ester. Our data provide evidence that oxidative stress induced by WBCs has a damaging effect on the polyunsaturated fatty acids of sperm phospholipids which may result, amongst other effects, in decreased membrane fluidity.

Fatty Acids↗
PubMed1996

Deterioration of sperm quality in young healthy Belgian men.

We have retrospectively analysed the sperm characteristics of 416 consecutive healthy young men who presented themselves in the past 19 years as candidate sperm donors. Ejaculate volume increased slightly (P = 0.067), and average sperm concentration decreased (P = 0.035) by 12.4 x 10(6)/ml over the observation period, so that sperm count per ejaculate remained unchanged (P = 0.91). In contrast, sperm morphology (r = - 0.23, P < 0.0001), rapid progressive motility (r = - 0.42, P < 0.0001) and total motility (r = - 0.33, P < 0.0001) presented an important and time-related decrease. When a quadratic model was used rather than a linear one to analyse the data on rapid progressive motility, there appeared to have been no further decline since 1990. The average proportion of spermatozoa with normal morphology decreased from 39.2% in the period 1977-1980 to 26.6% in 1990-1995 (P < 0.0001), and the mean percentage of spermatozoa with rapid progressive motility decreased from 52.7 to 31.7% (P < 0.0001). The percentage of candidate donors with sperm characteristics below the 5th percentile cut-off value of a normal fertile population increased from 13 to 54% during the observation period (P < 0.0001). Since the technique of semen analysis has remained essentially unchanged in-so-far as has been practically possible, as has the method of recruitment of candidate sperm donors, the observed deterioration of sperm characteristics is considered to reflect degeneration of sperm production among men aged between 20 and 40 years.

Adult↗
PubMed1996

The possible meaning of transferrin and its soluble receptors in seminal plasma as markers of the seminiferous epithelium.

Transferrin (Tf) and soluble transferrin receptors (S-Tf-R) were measured by enzyme immunoassay in seminal plasma of 130 semen samples. The mean concentration of S-Tf-R in cases with normozoospermia was 10.4 IU/ml (95% confidence interval: 9.5-11.3) and it was significantly lower in patients with oligozoospermia (6.6, 95% CI: 5.8-7.5, P < 0.001), asthenozoospermia (8.5, 95% CI: 5.5-10.7, P < 0.05), azoospermia of primary testicular origin (7.9, 95% CI: 6.1-9.6, P<0.05) and post-vasectomy samples (5.9, 95% CI: 5.4-6.9, P < 0.001). The concentration of S-Tf-R in post-vasectomy samples was lower than that in patients with azoospermia of primary testicular origin (P < 0.05; positive likelihood ration = 7 at value of 8.3 IU/ ml). S-Tf-R was positively correlated with motile sperm concentration (r = 0.50, P < 0.0001), percentage motility (r = 0.38, P < 0.001), percentage of normal forms (r = 0.43, P < 0.001), sperm linear velocity (r = 0.42, P < 0.001), and ATP concentration (r = 0.67, P < 0.0001). Follicle stimulating hormone (FSH) was found to be negatively correlated with the concentrations of both Tf (r = -0.31, P < 0.05) and of S-Tf-R (r = -0.45, P < 0.01). The mean concentration of Tf in seminal plasma was 50.4 micrograms/ml (35.9-67.2) in samples with normozoospermia (n = 22), and the concentration was significantly lower in patients with oligozoospermia (P < 0.05), azoospermia of testicular origin (P < 0.001), and post-vasectomy samples (P < 0.001). Seminal Tf was correlated with motile sperm concentration (r = 0.36, P < 0.001), percentage of motile spermatozoa (r = 0.25, P < 0.05), linear velocity (r = 0.24, P < 0.05) and ATP concentration (r = p.44, P < 0.001). The concentration of Tf was positively correlated with that of S-Tf-R both in cases with spermatozoa present (r = 0.66, P < 0.001), and in cases with azoospermia of testicular origin (r = 0.51, P < 0.05) but not in vasectomy cases. It is concluded that S-Tf-R in seminal plasma is a marker of spermatogenesis and may give information on the presence or absence of spermatogenetic cells in cases with azoospermia. Further investigations are needed to assess its usefulness for clinical practice.

Biomarkers↗
PubMed1995

MedCalc: a new computer program for medical statistics.

In recent years, the use and abuse of statistics in the medical literature has extensively been reviewed. Amongst others, the importance of the P-value has been challenged and the use of misleading graphics, including 3-dimensional displays, has been criticized. The ease of access to more complex statistical procedures, since the introduction of several statistical software packages for personal computers, has been identified as one of the factors involved in the misuse of statistics. Therefore, we have developed a new computer program that includes those statistical procedures commonly encountered in the medical literature and in statistical textbooks for medical researchers. More complex statistical analyses are not implemented in the software. If researchers with limited statistical training require more sophisticated statistical analyses, they should refer to a statistician, not to a more complete statistical software package.

Computer Graphics↗
PubMed1995

Comparison of different methods for the investigation of antisperm antibodies on spermatozoa, in seminal plasma and in serum.

Since there is no gold standard for the diagnosis of immunological infertility, comparison between different methods and of their results with biological tests for the detection of antisperm antibodies must be used in defining the most reliable and clinically relevant method. We have evaluated the results of direct (n = 100) and indirect tests in serum (n = 140) and seminal plasma (n = 100) using the SpermMAR and Immunobead (IB) techniques for the detection of sperm antibodies of the immunoglobulin (Ig) classes G, A and M, and we have compared the results with those of the tray agglutination test and the adenosine triphosphate release cytotoxicity test. Results indicate the higher specificity and sensitivity of the SpermMAR results for IgG and IgA, as compared to the outcome of the IB test. It appears that the IB test for IgA may detect non-specific antibodies in serum. Little information is obtained from the tray agglutination test in seminal plasma, and the indirect SpermMar test for IgG in seminal plasma was the only independent variable associated with the outcome of the former test. Since the SpermMAR tests for IgG and IgA are more accurate and biologically relevant, as well as easier to perform than the respective IB tests, the former must be considered the method of first choice.

Agglutination Tests↗
PubMed1995

Does treatment with testosterone undecanoate improve the in-vitro fertilizing capacity of spermatozoa in patients with idiopathic testicular failure? (results of a double blind study).

Seventy-seven couples in whom conventional in-vitro fertilization (IVF) had remained unsuccessful because of low fertilization rate and abnormal sperm characteristics were given either testosterone undecanoate 120 mg/day, or placebo during 3 months, after which a new IVF treatment was applied under identical technical conditions. There were no significant changes in sperm characteristics among the treated and placebo couples and the fertilization rate showed a similar increase after treatment in both groups. No significant difference in pregnancies occurred, with 32% pregnancies in the placebo controls and 17% among couples treated with testosterone undecanoate. It is concluded that testosterone undecanoate intake does not improve sperm characteristics, or the in-vitro fertilizing potential, or pregnancy rate over those observed in the placebo controls in cases with primary idiopathic testicular failure.

Adult↗
PubMed1995

Statement on the general reduction in sperm quality.

Over a period of 17 years, 360 young healthy men presented themselves as candidate donors for the sperm bank of the University Hospital of Ghent. Semen characteristics of these men were assessed using unaltered methods, and analysis was performed on the first sample delivered before any donor selection was performed. Sperm motility and morphology, but not the total sperm count per ejaculate, exhibited a highly significant decrease. Over 40% of candidate donors since 1990 exhibited subnormal sperm characteristics, as against only 5% of the group investigated before 1980.

Adult↗
PubMed1995

Varicocele: indications for treatment.

Varicocele is detected in about one-third of men with subfertile semen quality. Treatment by means of transcatheter embolization using the tissue adhesive Histoacryl improves Sertoli cell function with increased concentrations of transferrin in semen, and a significant increase in sperm concentration, normal morphology and linear velocity. Failure to attain pregnancy after varicocele treatment occurs if pre-treatment sperm quality is normal, or in the case of azoospermia with elevated blood FSH levels or obstruction, or when there is severe coincidental pathology impairing fertility of the male or female partner. In all other cases, the poor results of varicocele treatment reported in some studies can only be explained by inadequate techniques. Varicocele detection and embolization treatment at puberty or during adolescence should be advocated to prevent deterioration of testicular function.

Humans↗
PubMed1994

Methodological aspects of sperm morphology evaluation: comparison between strict and liberal criteria.

OBJECTIVE: To compare the methodological accuracy of different sperm morphology criteria. SETTING: A multicenter study including 10 laboratories with high expertise in semen analysis. PATIENTS: Semen preparations of subfertile men with a variable degree of teratozoospermia and of fertile semen donors. INTERVENTIONS: Detailed assessment of sperm morphology on 10 air-dried semen smears, of which 3 originated from the same ejaculate. RESULTS: The average coefficient of variation calculated on the three smears of the same ejaculate was higher when strict criteria for morphological normality were used and borderline cells were classified as abnormal than when criteria of abnormality were applied and borderline cells were considered normal. The correspondence between individual centers mutually and of each center with the average result of all centers was better when the latter approach was taken. The performance of two computer-assisted systems was intermediate between that of the two approaches, whereas one system gave unreliable results. CONCLUSIONS: Strict criteria for normality of sperm morphology, with borderline cells considered abnormal, gives results that are less reproducible and less accurate than the approach that classifies sperm as abnormal, with borderline cells considered normal.

Fertility↗
PubMed1992

Objective semen analysis: has the target been reached?

Objectivity in assessing critical sperm characteristics such as concentration, motility and morphology, has been the target of many systems and devices. Methods based on physical principles such as turbidimetry, spectrophotometry, laser Doppler technology, are too imprecise or technically too complicated to be applied routinely in the laboratory. Microscopic images providing photographical, cinematographical or video data acquisition followed by manual or computer-assisted image analysis (CASA) suffer from practical and/or device deficiencies, making them tedious and time-consuming, or unreliable because of confounding factors and uncontrolled artefacts. A single-step computer system using visual evaluation of the microscopic field and manual tracking of sperm movement yields more reliable results, but technician expertise remains essential for correct performance. The scientific basis of multiple errors in semen aspiration, chamber quality, data acquisition and analysis is given. Biased interpretations of results or incorrect handling of statistical data are criticised.

Humans↗
PubMed1991

Placebo-controlled trial of high-dose Mesterolone treatment of idiopathic male infertility.

The possible effect of Mesterolone (Schering N.V., Brussels, Belgium) (1 alpha-methyl-5-alpha-androstane-17 beta-ol-3-one) on semen quality and fertility of men with idiopathic oligoasthenospermia and/or teratozoospermia has been evaluated in a double-blind trial. The study included 52 patients who were treated during 12 months with either 150 mg/d of Mesterolone or placebo. The overall pregnancy rate was similar in the Mesterolone-treated cases (26%) and in the placebo control cases (48%), although a significant increase in motility and in the proportion of spermatozoa with normal morphology was recorded in the Mesterolone-treated cases. Because similar semen improvement also occurred in the placebo controls, our findings cast doubt on the possible usefulness of high-dose Mesterolone treatment of idiopathic male infertility.

Administration, Oral↗
PubMed1988

Accuracy of sperm characteristics in predicting the in vitro fertilizing capacity of semen.

Based on the results of in vitro fertilization (IVF) in 56 couples, the power was assessed of traditional sperm characteristics of native semen to discriminate between in vitro fertile and in vitro infertile semen. The number per ejaculate of spermatozoa with regular oval heads was the best discriminant, followed by the concentration of progressively motile spermatozoa. This contrasts with the in vivo fertilizing capacity, which depends mostly on the proportion and concentration of spermatozoa with rapid linear progression. The lower limit of sperm characteristics was assessed as the fifth percentile of in vitro fertile semen and was compared with the lower limit of semen of fertile men and of subfertile men who achieved spontaneous or treatment-related conception in vivo. It appeared that the semen quality needed for in vitro fertilization is inferior to that of fertile men but not remarkably different from that of subfertile men who achieved spontaneous conception during 1-year follow-up after consultation. If conventional methods for semen preparation are used, there seems to be no major advantage in favor of IVF for the treatment of male infertility due to sperm deficiency. An increased success rate may, however, be attained, thanks to improved techniques of semen collection, semen preparation, and oocyte insemination.

Female↗