Publications by authors named "Conradie E"

We describe a competitive colorimetric assay that enables rapid and sensitive detection of galactose and reduced nicotinamide adenine dinucleotide (NADH) via colorimetric readouts and demonstrate its usefulness for monitoring NAD+-driven enzymatic reactions. We present a sensitive plasmonic sensing approach for assessing galactose concentration and the presence of NADH using galactose dehydrogenase-immobilized gold nanostars (AuNS-PVP-GalDH). The AuNS-PVP-GalDH assay remains turquoise blue in the absence of galactose and NADH; however, as galactose and NADH concentrations grow, the reaction well color changes to a characteristic red color in the presence of an alkaline environment and a metal ion catalyst (detection solution).

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Plasmonic colorimetric sensors have emerged as powerful analytical tools in biochemistry due to their localized surface plasmon resonance extinction in the visible range. Here, we describe the feasibility of NAD(P)/NAD(P)H as redox agents in enzymatic plasmonic gold nanostar (AuNS) assays for galactose quantification using three model enzymes, GalDH, AR and GalOx, immobilized separately on polyvinylpyrrolidone-capped AuNS scaffolds. These highly specific, sensitive and selective bioassays induce the transformation of AuNS into quasi-spherical nanoparticles during the biorecognition of galactose in water and synthetic blood matrices.

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The North-West University's Centre for Human Metabolomics (CHM) is in the process of establishing the first rare disease (RD) biobank in South Africa and Africa. The CHM Biobank's main focus is on the collection of samples and information for rare congenital disorders. Approximately 72% of all RDs have a genetic origin, of which 70% have an exclusive pediatric onset.

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Background: Uncertainty exists whether a therapeutic early mobility position will affect the outcome of a critically ill patient.

Objectives: To evaluate the feasibility of an existing protocol to identify patients who would tolerate this position.

Research Methodology/design: A non-randomised experimental pilot trail was performed.

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Cryopreservation of Vervet monkey semen caused a highly significant reduction in the percentage of normal acrosomes and a highly significant increase in the percentage of mildly damaged, severely damaged, and lost acrosomes. This was demonstrated by staining ten post-thaw semen samples, which enabled a visualization of the acrosomal damage. The incidence of post-thaw intact acrosomes in this cryopreservation method was found to be similar to that reported for man and cynomolgus monkey semen.

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A method to cryopreserve semen from the Vervet monkey (Cercopithecus aethiops) has been developed, yielding a mean post thaw recovery of 63.60% of pre-freeze progressive motility. The extender contained a TES-TRIS buffer, egg yolk, dextrose, streptomycin, penicillin, and glycerol as cryoprotectant.

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Buspirone (Buspar; Bristol) marks a departure from established concepts of anxiolysis. Differing substantially both in its mode of action and in the clinical expression of its action from agents such as barbiturates and benzodiazepines, it would seem to operate chiefly via the 5-HT1A subtype of serotonin receptor. Such receptor selectivity is likely to be responsible for the novel action of this anxiolytic in that sedation and psychomotor and cognitive dysfunction are minimal, and because dependence is unlikely.

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Phase I (3 June - 31 October 1983) of the in vitro fertilization (IVF) programme at Tygerberg Hospital is outlined in this article. This programme led to the birth of the first IVF baby in South Africa after fertilization and embryo transfer (ET) took place at this institution. The baby was born on 29 April 1984; a second baby was born on 20 June 1984.

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The effect of surgical glove powder on the development of early mouse embryos was studied. Embryos from F1 hybrid mice (C57 B1/6 X CBA) were suspended in Whittingham's T6 growth medium with 10% human serum, using Petri dishes (Falcon 3001). Contamination was brought about by a sterile, powdered, surgical glove touching the surface of the growth medium for less than a second in group I, and in group II the same procedure was followed but the glove was rinsed beforehand with sterile, four times distilled water and air-dried.

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A new method for counting spermatozoa was introduced by Makler. This method was compared with the white blood cell pipette method and the results revealed high precision and accuracy (difference of means = 5,9%). Makler's method, which is very simple to perform, has the advantage that rapid and reliable sperm counts can be done.

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