Markus Fourie

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Occupational exposure to airborne manganese dust has been shown to produce adverse effects on the central nervous system. Four hundred and eighty-nine blue and white collar manganese mineworkers from South Africa were studied cross-sectionally to investigate the nervous system effects of medium to low occupational manganese exposures. The different(More)
Twenty-nine deletion mutant lines were used to extend a physical map of the Lr19 translocated chromosome segment. One hundred and forty-four Sse8387I/MseI and 32 EcoRI/MseI primer combinations were used to obtain 95 Thinopyrum-specific AFLP markers. The physical map confirmed that terminal deletions had mostly occurred, however, it appears that intercalary(More)
It has been suggested that alpha-glucosidase may be a marker of epididymal patency and function. Spermatozoal ATP concentrations decrease during passage through the epididymis, indicating efficient maturation. We correlated sperm motility with seminal plasma alpha-glucosidase activity and spermatozoal ATP. The sperm motility correlation with(More)
Low spermatozoal ATP concentration in the presence of high alpha-glucosidase activity may indicate efficient epididymal function. It was suggested that detached ciliary tufts (DCTs) originated from the epididymis. We compared the spermatozoal ATP concentration and alpha-glucosidase activity in semen of patients with DCTs to that of a control group. Higher(More)
The epididymis is the site of posttesticular sperm maturation in the male genital tract. Studies on human epididymides are hampered by the practical inaccessibility of epididymides of healthy men in their reproductive years. The limited use of laboratory animals therefore seems unavoidable. The objective was to establish baseline values of the epididymal(More)
Harmful micro- and macroscopic effects of the environmental xenoestrogen p-nonylphenol (p-NP) on the male rat reproductive system have been previously reported. In our study, biochemical evidence of epididymal involvement was sought by determining epididymal marker values after exposure at levels below (5, 20 and 50 mg kg-1) and above (100, 250 and 400 mg(More)
Low alpha-glucosidase activity in seminal plasma is a marker of epididymal obstruction. The criterion standard for determining activity is the epididymal specific method, whereby the neutral iso-enzyme, specifically produced by the epididymis, is measured. A kit that determines total alpha-glucosidase activity (neutral iso-enzyme and the acid iso-enzyme(More)
The ability of the markers alpha-glucosidase, carnitine, and glycerylphosphorylcholine to indicate epididymal obstruction was studied. alpha-Glucosidase was found to be the best discriminant, with 93.4% correct classifications. The possible interrelationship between alpha-glucosidase activity, sperm ATP, and epididymal function was then studied.(More)
Good sperm motility in normozoospermic men was associated with high bound and total sialic acid (SA) and pyruvate concentrations in the seminal plasma, as well as high endogenous (sperm) pyruvate concentrations. The presence of sialidase in the seminal plasma was also demonstrated for the first time. The results suggest that SA is metabolized to pyruvate by(More)
Epididymal maturation of sperm entails molecular changes to the sperm plasma membrane. These changes are reflected by changes in lectin binding. The wheat germ agglutinin (WGA) lectin was used, since it binds to acetylglucosamine and sialic acid, which are involved in sperm function. The objective was to study changes in WGA-lectin binding during epididymal(More)