PubMed Health⌕ Search

Biomedical subjects

C Depuydt

Publications and source records attributed to C Depuydt.

8 recordsLinked to original sources
PubMed1999

[A strategy for the prevention of male infertility].

Since 1990 there has been a simultaneous reduction of natality in Flanders (by approximately 12%) with increased demand for assisted reproduction, while sperm quality, mostly motility and morphology, have clearly deteriorated over recent decades. This evolution has been ascribed to the deleterious effects of hormone disrupting substances in the environment, synergistically enhancing unfavorable influences from life style and possible genito urinary diseases that can impair the function of the testes and accessory sex glands. It is probable that this synergistic effect is exerted through the intermediate of free oxygen radicals (also called reactive oxygen species) that damage both the sperm membrane and sperm DNA, which could allow certain minimal inborn genetic defects (such as point lesions) to come to expression. Both pseudo- or xeno-estrogens (such as certain organo chlorides, alkyl phenols, phthalates, etc.) and anti-androgens are held responsible for prenatal testicular damage and increased prevalence of testicular carcinoma and oligozoospermia, for anatomical malformations, as well as postnatal depression of testicular function and spermatogenesis. However, methods presently available to detect hormone disrupters are tedious and not fully adequate. A first strategic goal is to develop a simple method for the detection of these substances so that environmental pollution can be mapped. Fazing out the production and application of hormone disrupters, and removing them from the environment are the second strategic step. Also, a health food is being developed that will inhibit the absorption of these chemicals from the intestinal tract. In addition it is projected to detect and treat common genital diseases that can cause infertility, such as varicocele and infection of the urinary tract and accessory sex glands. The first could be organized to take place during medical examinations at school, whereas the second requires correct medical treatment of any cysto urethritis in adolescents. Non surgical treatment of varicocele by means of transcatheter embolization offers a cost effective approach, with minimal risk and complications, and high level of efficacy. Improving food quality and educational efforts aimed at a healthier life style should score high priority. The suggested strategy uses several entries in order to address the multifactorial mechanisms involved in the pathogenesis of male infertility. Preliminary epidemiological and biological data suggest that the proposed strategy can, indeed, be successful within a relatively short lapse of time.

Belgium↗
PubMed1998

Seminal plasma alpha-glucosidase activity and male infertility.

Measurement of alpha-glucosidase (alpha-GLUC) activity by means of a simple colorimetric test using a commercial kit (EpiScreen; FertiPro, Lotenhulle, Belgium) yielded results that were strongly correlated with the values obtained for the neutral iso-enzyme measured by a fluorimetric reference method (r=0.85, P=0.003, n=13). The former method was characterized by a low intra- and inter-coefficient of variation (6.6 and 4.3% respectively). Vasectomized men with azoospermia (n=27) had a significantly lower alpha-GLUC activity in semen than vasectomized men with residual spermatozoa present (n=11, P < 0.01) and men with azoospermia of primary testicular origin (n=33, P < 0.01). Receiver operating curve (ROC) analysis showed alpha-GLUC measurement to be reasonably accurate in differentiation between cases with obstructive versus testicular azoospermia at criterion value 13.5 U/l (sensitivity=82%, specificity= 70%). In cases with spermatozoa present, alpha-GLUC activity and output per ejaculate were positively correlated with sperm concentration (r=0.53 and 0.38, n=472), linear velocity (r=0.35 and 0.30, n=224), curvilinear velocity (r=0.32 and r=0.29, n=224), semen adenosine triphosphate (r=0.35 and 0.26, n=64), the concentration of 5alpha-dihydrotestosterone (r=0.31 and 0.29, n=74), and gamma-glutamyltransferase activity (r=0.62 and 0.32, n=275) in seminal plasma. The activity of alpha-GLUC was inversely correlated with ROS generation after 12-myristate, 13-acetate phorbol ester stimulation (r=-0.27, n=104), and both alpha-GLUC activity and total output were inversely correlated with the concentration of peroxidase-positive white blood cells among samples with > or =1x10(6)/ml of these cells (r=-0.30 and -0.19, n=165). It is concluded that simple photometric measurement of alpha-GLUC activity in seminal plasma reflects the functional state of the epididymis and may be helpful for the differential diagnosis of certain cases with azoospermia.

Colorimetry↗
PubMed1998

Mechanisms of sperm deficiency in male accessory gland infection.

The presence of 2 million or more peroxidase-positive white blood cells per ml of semen, or the diagnosis of male accessory gland infection, is associated with important biochemical and biological changes in semen plasma and in the spermatozoa, reducing their fertilizing potential in vitro and in vivo (e.g., during intra-uterine insemination). In addition to the effects of reactive oxygen species, and its influence on the essential fatty acid composition of the sperm membrane, potentially unfavourable effects can occur through the intermediate of increased concentrations of certain cytokines, and decreased activity of enzymes such as alpha-glucosidase. In contrast, lower numbers of white blood cells may exert beneficial effects on spermatozoa thanks to the increased production of hepatocyte growth factor/scatter factor (a tissue repairing substance), and the stimulation of immuno-competent cells by particular cytokines (e.g., Interleukin-6).

Cytokines↗
PubMedDate not supplied

Parallel visual and memory processes.

We studied parallel processes: visual processes with the prosaccade, the no-saccade and the antisaccade task on the one hand and memory processes with the random tap task on the other hand. The random tap task is believed to be a pure interference task for the central executive component of working memory. The number of saccadic errors was found not to be influenced by taxing the central executive, while the latency times were significantly increased both in the prosaccade and in the antisaccade task. The effect seen in the antisaccade task was expected since it is a non-automatic activity under central executive control. Because the prosaccade task is an automatic activity, an effect of central executive load was not expected. As an explanation for our findings, we postulate that the prosaccade task is brought under willed control of the central executive.

Adolescent↗