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Welcome to the NWU Repository, the open access Institutional Repository of the North-West University (NWU-IR). This is a digital archive that collects, preserves and distributes research material created by members of NWU. The aim of the NWU-IR is to increase the visibility, availability and impact of the research output of the North-West University through Open Access, search engine indexing and harvesting by several initiatives.

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DEFEKTE TETRAHIDROBIOPTERIENHOMEOSTASE IN 'N SWART FAMILIE MET HIPERFENIELALANIENEMIE
(North-West University, 1993) Nicoleen Potgieter
In 1984 the Department of Biochemistry of the Potchefstroom University for Christian Higher Education introduced a metabolic screening programme. Results from a two year research project on defective amino acid metabolism of 1443 clinically selected patients are presented. Utilization of a dual screening approach consisting of one-dimensional thin layer chromatography and automatic amino acid analysis led to the identification of various abnormalities associated with known metabolic defects. Seven different types of amino acidurias were diagnosed in a total of 15 positively tested patients. Hyperphenylalaninemia accounted for 5 of the amino acidurias of which one was a very rare case of malfunctional phenylalanine metabolism. Amongst the total screened group, atypical ninhydrin positive components were found in approximately 13 % of the analyzed urine samples. It was not possible to link the presence of these components to any known defect of the amino acid metabolism. Given that the presence of the atypical ninhydrin positive components complicates the interpretation of laboratory results, it was necessary to investigate their nature and origin. Different separation techniques were applied in an attempt to isolate the metabolites responsible for the atypical ninhydrin colour complexes. However, it was not possible to isolate these metabolites using the normal protocol for isolation of amino acids. This led to the conclusion that their physico-chemical properties did not correspond with that of known amino acids. GC-MS analysis indicated structural similarities between these atypical compound(s) and amino acid conjugates associated with some organic acidurias. Analysis of a consignment of samples obtained from newborns on antibiotic treatment focused the attention on medication as possible cause of the atypical ninhydrin positive components. GC-MS analysis indicated the presence of a metabolite of the penicillin molecule in the urine of patients receiving antibiotics. These results were confirmed by a penicillin loading test on a healthy individual. Hyperphenylalaninemia (HPA) is not prevalent in Negroids. Therefore, the case of a black baby girl with HP A discovered during this study was exceptional. Using a dual screening procedure, elevated levels of phenylalanine were detected in different plasma specimens of the patient. The extent of the elevation was such that it could not be associated with phenylketonuria (PKU), but rather a variant of the disease. An approach investigating the disease on metabolite as well as enzyme level was formulated. A tentative diagnosis was made on the overall status of metabolites in the phenylalanine hydroxylase system, after which the diagnosis was confirmed by enzymatic analysis. Metabolite analyses revealed the presence of phenolic compounds in the patient's urine. A phenylalanine loading test indicated that the clearance rate of the excess phenylalanine from the patient's bloodstream was impaired. However, her phenylalanine levels did not rise as much as commonly expected in the case of PKU. Although this result was indicative of a tetrahydrobiopterin-defect (BH4), the patient did not react positively to the administration of 20 mg BH4/kg mass. The patient's excretion pattern of urinary pterines, as well as her low levels of active BH4 were consistent with a DHPR-defect. The reduced levels of neurotransmitter metabolites in cerebrospinal fluid of the patient also indicated a DHPR-defect. Information obtained from the metabolite analyses indicated DHPR-defect as the possible cause of hyperphenylalaninemia in the patient. This diagnosis was confirmed when no DHPR-activity could be demonstrated in dried blood spots from the patient. Given that the patient did not react to a high dose of 20 mg BH4 per kilogram of weight, the disorder is referred to as non-responsive dihydropteridine reductase deficiency. The patient described here is not only the second case of non- responsive DHPR-defect in the world, but also the first black patient diagnosed with this disease.
PAKKETVERGOEDING EN SOSIALE VERANTWOORDELIKHEID
(North-West University, 1998) Frederick Petrus Pretorius
STATISTIESE METODES AS HULPMIDDEL IN DIE BESLUITNEMINGSPROSES - GEVALLE STUDIES UIT DIE STAALBEDRYF
(North-West University, 1982) Maurice Pereira; De Wet A.G
N BEMARKINGSTRATEGIE VIR DIE HANDELSAFDELING VAN DIE MAGALIESBERGSE GRAANKOOPERASIE BEPERK
(North-West University, 1994) Rian Pheiffer; POTGIETER MNR. H
A strategic approach to the marketing field of the MGK is of vital importance to ensure survival in the current climate of uncertainty and change. This approach would ensure that the numerous new opportunities are not lost. The findings in the study indicate that the importance of the current known market, namely the co-operative's members should not be neglected. On the other hand new opportunities in terms of the changing legislation must be investigated. It is, however, of vital importance to approach these two markets in a strategic manner to ensure maintenance and growth in the current member market and not to let it slip past while effort and focus are placed on an unknown market. The study indicates, however, that the non-member market must be investigated in terms of marketing research on consumer behaviour, facilities, geographical locations, etc.
Clarifying the affective component of psychological well-being
(North-West University South Africa, 1999) Walker, Hayley Janay; Nienaber, A W
The aim of this study was to clarify the affective component of psychological well-being. From the relevant literature it is clear that an affective component of psychological well-being may be distinguished, but that it is not clear what it`s nature is, and to what extent indicators thereof overlap with indices of general psychological well-being. It emerged that there are two main models to conceptualize this affective component namely an affect balance model in which the balance of positive and negative affect is viewed as the essence of emotional well-being and secondly, the emotional intelligence model in which the effective regulation of emotion in the self and others is viewed as the essence of emotional well-being. In addition, the literature highlights the role of different gender, age and ethnic/cultural groups as influential variables in this affective component of psychological well-being. In an empirical investigation an availability sample of 382 individuals comprising four different age groups were involved (18-25, 26-40, 41-50 and 51-65 years). A survey was conducted on the affective component of psychological well-being (affect-balance and emotional intelligence) and general psychological well-being in a one shot cross-sectional design. In this study the affective component was operationalised with the BarOn Emotional Quotient Inventory (EQ-i) of Bar-On (1997a) and the Affectometer 2 (AFM) of Kammann and Flett (1983). Psychological well-being was operationalised from a fortigenic perspective with the Sense of Coherence Scale (SOC) of Antonovsky (1989), the Satisfaction with Life Scale (SWLS) of Diener, Emmons, Larsen and Griffen (1985) and from a pathogenic perspective with the General Health Questionnaire (GHQ) of Goldberg and Hillier (1979). Data was analyzed separately for the Total Group, different age groups, genders and cultural/ethnic groups. Findings indicated relatively good reliability indices for all scales and sub-scales. Means obtained on all scales and sub-scales are comparable to those reported in the literature for other similar groups. The construct validity of the EQ-i was determined by factor analyses and was found to be very much the same as in the original standardizing group The results indicated significant differences between Men and Women, the different age groups and the White and Black Groups on the affective component of psychological well-being. The Affectometer 2 of Kammann and Flett (1983) displayed significant positive correlations with the Emotional Quotient Inventory of Bar-On (1997a). Scores obtained on indices measuring the affective component also showed significant positive correlations with scores on indices measuring general psychological well-being. The affective component contributed significantly to the prediction of psychological well-being. Factor analyses further suggests that operationalizations of the intrapersonal aspects of emotional intelligence (Bar-On, 1997a) and affect balance (Kammann and Flett, 1983) overlap with, and form a strong component of general psychological well-being. Thus, the affective component is conceptualized by the balance of positive and negative affect and aspects of emotional intelligence and proves to be a strong component of general psychological well-being. The essence of this component seems to be affect balance. Accordingly, the results of this study are mainly in support of the affect balance model. Recommendations for further research and enhancement of psychological health on a practical level were made.