http://hdl.handle.net/11189/1931 2026-08-12T10:52:34Z 2026-08-12T10:52:34Z Cronjé, Johannes C. http://hdl.handle.net/11189/7869 2023-02-15T06:26:18Z 2013-01-01T00:00:00Z

Title: What is this thing called “design” in design research and instructional design Authors: Cronjé, Johannes C. Abstract: This paper will consider the phenomenon of design research. It will then consider four research posistions in social science research. The paper will show how the design perspectives map onto the research paradigms and how by rotating through these paradigms, a design research cycle is formed. Finally, the paper will discuss four research questions that drive design and development research and illustrate this by way of a case study.

2013-01-01T00:00:00Z Gamieldien, Kareemah Maritz, Gert S http://hdl.handle.net/11189/6694 2018-11-29T10:43:59Z 2004-01-01T00:00:00Z

Title: Postnatal expression of cytochrome P450 1A1, 2A3, and 2B1 mRNA in neonatal rat lung: influence of maternal nicotine exposure. Authors: Gamieldien, Kareemah; Maritz, Gert S Abstract: A critical factor contributing to the etiology or modification of respiratory disease is the ability of the lung tissue to activate or inactivate chemicals. In this study, the authors investigated the effect of maternal nicotine exposure during gestation and lactation on the expression mRNA of cytochrome P450 (CYP) CYP1A1, CYP2A3, and CYP2B1. Fetal rats were exposed to nicotine via maternal administration of nicotine (1 mg/kg body weight/day, subcutaneously); after birth, neonatal rats were exposed to nicotine via the mother's milk. Lung tissue of 1-, 7-, 14-, 21-, and 49-day-old rat pups were used. From weaning on postnatal day 21 up to postnatal day 49, the offspring received no nicotine. Using RNA dot-blot techniques, our results show that CYP mRNA expression in lung tissue increased with age after birth. Maternal nicotine exposure had no influence on CYP1A1 mRNA, but resulted in a marked increase in the expression of CYP2A3 mRNA and CYP2B1 mRNA. The higher levels of CYP2A3 mRNA and CYP2B1 mRNA were maintained after weaning. Description: Article

2004-01-01T00:00:00Z Wentzel, Gelderblom Joubert, Elizabeth Gamieldien, Kareemah Sissing, L Malherbe, Christiaan J Maritz, Gert http://hdl.handle.net/11189/6692 2018-11-29T09:47:23Z 2017-01-01T00:00:00Z

Title: Rooibos (Aspalathus linearis), honeybush (Cyclopia intermedia) and cancer bush (Sutherlandia frutescens subsp. microphylla) protect against tobacco-specific mutagenesis in vitro Authors: Wentzel, Gelderblom; Joubert, Elizabeth; Gamieldien, Kareemah; Sissing, L; Malherbe, Christiaan J; Maritz, Gert Abstract: Antimutagenesis studies against the tobacco-specific mutagens 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N-oxide, 4 (methyl-nitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), were conducted using hot water aqueous extracts of rooibos (Aspalathus linearis), honeybush (Cyclopia intermedia), and cancer bush (Sutherlandia frutescens). Aqueous extracts of both “fermented” and “unfermented” (green) rooibos and honeybush were included, while extracts of green and black teas (Camellia sinensis) served as benchmarks. A polyphenol-enriched methanol extract of unfermented rooibos (RgM) was included to further elucidate the possible role of rooibos polyphenols. Studies were performed in the presence of the metabolic activation against Salmonella typhimurium tester strain TA1535, using the standard plate incorporation and micro-suspension, pre-incubation assays. The mutagenic effects of NNK against the strain TA1535 was best demonstrated using the standard plate incorporation assay, while a higher mutagenicity was demonstrated for NNAL using the micro-suspension, pre-incubation method. Black tea and RgM exhibited the highest protection against NNK-induced mutagenesis followed by the aqueous extracts of rooibos ≥ green tea ≥ honeybush ≥ cancer bush. Black tea, green tea, RgM and unfermented rooibos were the most effective against NNAL-induced mutagenesis, followed by fermented rooibos. The two honeybush extracts exhibited similar, but the weakest protective response. When considering the amount of total polyphenols (TPP) incorporated in the plate incorporation assay, cancer bush exhibited similar protection to that of fermented and unfermented honeybush against NNK mutagenesis. The involvement of specific polyphenol-cytochrome P450 (CYP450) interactions is likely to be involved in the protection against tobacco-related mutagenesis. Polyphenol constituents of rooibos, honeybush and cancer bush could play an important role in the protection against mutagenesis induced by the major tobacco-specific carcinogens. Description: Article

2017-01-01T00:00:00Z Selepe, Malesiba Mampotoko Van Wyk, Abrie Hoek, Kim Gilberte Pauline Prince, Yvonne http://hdl.handle.net/11189/6684 2018-11-14T09:13:43Z 2018-01-01T00:00:00Z

Title: Papanicolaou induced fluorescence, Ziehl-Neelsen and Auramine O stains on lymph node fine needle aspiration biopsy specimens from children: A comparative study Authors: Selepe, Malesiba Mampotoko; Van Wyk, Abrie; Hoek, Kim Gilberte Pauline; Prince, Yvonne Abstract: Background The rapid diagnosis of extrapulmonary tuberculosis in children remains challenging. The presence of enlarged lymph nodes provides an opportunity to obtain diagnostic material through fine needle aspiration biopsy (FNAB). Mycobacterial culture, traditionally the reference standard, has a slow turnaround time and PCR‐based methods are not widely available in developing countries. Direct visualization of mycobacteria on microscopy can be a rapid method to confirm the diagnosis. This study compared three staining methods to visualize mycobacteria. Methods Hundred FNAB specimens from persistently enlarged lymph nodes in children, clinically suspicious for tuberculosis, were evaluated for the presence of mycobacteria by three staining methods: Papanicolaou induced fluorescence (PIF) and Auramine O staining using fluorescence microscopy and Ziehl‐Neelsen (ZN) staining using conventional light microscopy. These methods were evaluated against mycobacterial culture. Results PIF positivity was 30%, with 38% and 48% for Auramine O and ZN respectively. The combined ZN/PIF positivity was 56%. The highest diagnostic accuracy (73%) was demonstrated by ZN alone and in combination with PIF, with PIF alone showing the lowest (49%) accuracy. Although the combined test showed the highest sensitivity, it had the lowest specificity, while ZN was significantly more sensitive than both other staining modalities. No statistical difference in specificity was seen among the tests. Conclusion This study suggests that Auramine O staining on previously ZN stained slides does not significantly improve diagnostic accuracy. While currently widely available methods of direct visualization of mycobacteria suffer from low sensitivity, the ZN stain remains a useful diagnostic test, particularly in resource‐constrained countries. Description: Article

2018-01-01T00:00:00Z