Stellenbosch University - Scopus Tygerberg Hospital Publications

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25th European Symposium on Calcified Tissues entitled 'Defining Typologies in Osteoporosis', Harrogate, April 25, 1997 : Fast and slow bone losers: Relevance to the management of osteoporosis
(1998) Hough, S.
A low bone mineral density (BMD) is presently regarded as the most important risk factor for the development of osteoporosis. BMD is a function of peak bone mass attained during growth and subsequent age-related bone loss. BMD can be measured accurately and precisely, although the rate of bone loss is more difficult to assess. When axial BMD was measured, the rate of bone loss was shown to increase by 2- to 4-fold at the menopause. Although this rate varies markedly between individuals, it is symmetrically distributed, which argues against the existence of a subpopulation of fast bone losers. Levels of biochemical markers of bone turnover (e.g. osteocalcin, bone specific alkaline phosphatase, deoxypyridinoline) also increase markedly at the menopause. and individuals with a high turnover tend to lose bone more rapidly. Moreover, since increased bone resorption also results in qualitative changes regardless of BMD, a high bone turnover constitutes an independent risk factor. Currently, large intraindividual variations (10 to 40%) in levels of biochemical markers and assay errors still limit our ability to correctly classify individual patients as fast or slow bone losers. The routine use of these markers as a screening tool to predict the risk of osteoporosis in individuals is of limited value, although their selective use in therapeutic decision-making is more promising.
5- and 6-glycosylation of transferrin in patients with Alzheimer's disease
(2004) Van Rensburg S.J.; Berman P.; Potocnik F.; MacGregor P.; Hon D.; De Villiers N.
Transferrin is a glycosylated metal-carrying serum protein. One of the biological functions of glycosylation is to regulate the life span of proteins, less glycosylation leading to a faster clearance of a protein from the circulation. In the case of transferrin, this would indirectly also influence iron homeostasis. Higher glycosylation has been demonstrated in patients with Parkinson's disease and rheumatoid arthritis. A genetic variant of transferrin, TfC2, occurs with increased frequency in patients with Alzheimer's disease (AD), rheumatoid arthritis, and other diseases associated with a free radical etiology. Investigations have so far not revealed the reason for the pro-oxidative qualities of TfC2. In this study the glycosylation of Tf in AD (TfC1 homozygotes and TfC1C2 heterozygotes) was compared with alcohol-induced dementia (AID) patients and nondemented, age-matched controls, using isoelectric focusing followed by blotting with anti-Tf antibodies. In TfC1 homozygotes a shift was found toward higher sialylation, but in TfC1C2 heterozygotes the 5- and 6-sialylated bands were less concentrated. The decreased sialalytion found for TfC1C2 heterozygotes, may indicate that the pro-oxidative TfC2 molecules are removed from the circulation at a faster rate than TfC1. This may be of benefit to AD patients having TfC2, but still does not explain why this Tf variant is pro-oxidative.
A 21-year-old patient with acute myeloid leukemia and bilateral pulmonary infiltrates
(2001) Theron J.; Ainslie G.; Schneider J.W.; Bates W.D.; Bolliger C.T.
[No abstract available]
A comparative study of the effects of cholesterol, beta-sitosterol, beta-sitosterol glucoside, dehydroepiandrosterone sulphate and melatonin on in vitro lipid peroxidation
(2000) Van Rensburg S.J.; Daniels W.M.U.; Van Zyl J.M.; Taljaard J.J.F.
The free radical scavenging abilities of the structurally related steroids beta-sitosterol, beta-sitosterol glucoside (plant sterols and sterolins), cholesterol, and dehydroepiandrosterone sulphate (DHEAS) were compared with melatonin (an efficient free radical scavenger) in an in vitro system which measures lipid peroxidation of platelet membranes in the presence of iron (Fe2+). Lipid peroxidation is a process whereby cellular membranes are damaged due to the oxidative deterioration of polyunsaturated lipids, which may lead to cell death and disease in living organisms. Substances such as vitamin E protect cellular membranes against oxidative damage due to their chemical structures. The steroids cholesterol, beta-sitosterol, beta-sitosterol glucoside and dehydroepiandrosterone (DHEA) are structurally related to each other. During aging, serum concentrations of DHEA, DHEAS and melatonin decrease, while the concentration of cholesterol tends to increase. The aim of the present study was to compare the role these substances play in lipid peroxidation over a wide concentration range. At concentrations lower than the free iron in the reaction mixture, all the steroids investigated decreased lipid peroxidation. At higher concentrations, cholesterol and beta-sitosterol increased lipid peroxidation, while DHEAS and melatonin continued to decrease lipid peroxidation.
Advantages of strict (Tygerberg) criteria for evaluation of-sperm morphology
(1995) Menkveld R.; Kruger T.F.
The purpose of this paper was to compare the validity of strict criteria for sperm morphology evaluation with other evaluation criteria in the diagnosis and prognosis of male fertility potential. Adoption of strict criteria is a holistic approach to sperm morphology evaluation which uses optimal preparation and evaluation procedures and criteria for a morphologically normal spermatozoan based on biological evidence. If liberal evaluation criteria are used, two sperm populations will be included in the normal population, namely those that are truly normal and an abnormal population. It was therefore postulated that results of strict criteria evaluation should provide better correlations with functional tests and fertilization outcome. In most studies where strict criteria was compared to WHO criteria it was found that strict criteria was a better prognosticator of expected in-vitro fertilization rates than WHO criteria. With regard to between- and within-observer correlation coefficients and coefficients of variation for repeated evaluations, results obtained using strict criteria compared favourably with or were better than results reported in the literature. Normal morphology, as evaluated by strict criteria, was also highly predictive of the outcome of certain functional tests, such as the hemizona assay and acrosin activity. From these and other data presented in this paper it can be concluded that sperm morphology evaluated according to strict criteria has definitive advantages over the other (liberal) criteria evaluation methods in the prediction of expected in-vivo and especially in-vitro fertilization rates.
African experience with training courses on sperm examination
(2008) Franken D.R.; Aneck-Hahn N.
In conjunction with the World Health Organization's Department of Health and Research, the Department of Obstetrics and University of Stellenbosch, South Africa presented since 1997 hands-on semenology workshops for 87 health care workers from 16 Sub-Sahara African countries. The programme consists of a five-day workshop, during which participants underwent a pre-training test after which they received intensive hands-on training on sperm concentration, motility, vitality and sperm morphology. Following the workshop, all the participants were enrolled in a continuous quality control programme for sperm morphology. The morphology reading skills of 53 workshop participants that enrolled for the external quality control programme were analysed and classified over an extended period. The reading skills were monitored using 36 slides (18 sets over 48 months). Three participants (5.7%) had a poor standard of reading, 6 participants (11.3%) had a marginal standard of reading and 45 participants had an acceptable reading standard (83%). An external quality control programme can be highly successful, on condition that it is presented continuously with a 3-4 month interval between tests. Our results underline the importance of hands-on training and moreover the crucial role that follow up external quality control programmes plays in the maintenance of a technicians reading skills. This observation can be validated for all semen parameters. © The Author 2008. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved.
Biochemical model for inflammation of the brain: The effect of iron and transferrin on monocytes and lipid peroxidation
(2004) Van Rensburg S.J.; Van Zyl J.; Hon D.; Daniels W.; Hendricks J.; Potocnik F.; Erasmus R.
Cerebral inflammation plays a role in diseases such as multiple sclerosis (MS), Alzheimer's disease (AD), and depression. Iron is involved in infection and inflammation through free radical production. Theoretically transferrin should prohibit iron from participating in oxidative reactions, but transferrin has also been found to promote free radical damage. We reported previously that isolation of transferrin from plasma by ion exchange column chromatography produced a broad pink protein band that subsequently separated on a gel filtration column into three proteins containing many metals. In this study some properties of the three proteins were studied in 20 volunteers. Protein 3 (identified as transferrin by nephelometry) contained the most iron while Protein 1 (called "toxiferrin") contained significantly less iron (p < 0.00001). Plasma from volunteers obtained under conditions of infection/inflammation with fever (n = 5) had a significantly increased toxiferrin to transferrin ratio compared to healthy volunteers (n = 15; p < 0.001). In vitro, Protein 2 and transferrin inhibited lipid peroxidation, while toxiferrin (possibly a protease degradation product of transferrin), enhanced lipid peroxidation. Also, toxiferrin (1 mg/mL) caused a significant increase in viability of monocytes as measured by the 3-(4,5-dimethyl-thiazol-2-yl) 2,5-diphenyl tetrazolium bromide (MTT) reduction test, as well as the morphological transformation of monocytes to macrophages.
Central nervous system manifestations of HIV infection in children
(2009) George R.; Andronikou S.; Du Plessis J.; Du Plessis A.-M.; Van Toorn R.; Maydell A.
Vertically transmitted HIV infection is a major problem in the developing world due to the poor availability of antiretroviral agents to pregnant women. HIV is a neurotrophic virus and causes devastating neurological insults to the immature brain. The effects of the virus are further compounded by the opportunistic infections and neoplasms that occur as a result of the associated immune suppression. This review focuses on the imaging features of HIV infection and its complications in the central nervous system. © 2009 Springer-Verlag.
Childhood tuberculosis: The hidden epidemic
(2004) Donald P.R.
[No abstract available]
Computer-aided detection of pulmonary pathology in pediatric chest radiographs
(2010) Mouton A.; Pitcher R.D.; Douglas T.S.
A scheme for triaging pulmonary abnormalities in pediatric chest radiographs for specialist interpretation would be useful in resource-poor settings, especially those with a high tuberculosis burden. We assess computer-aided detection of pulmonary pathology in pediatric digital chest X-ray images. The method comprises four phases suggested in the literature: lung field segmentation, lung field subdivision, feature extraction and classification. The output of the system is a probability map for each image, giving an indication of the degree of abnormality of every region in the lung fields; the maps may be used as a visual tool for identifying those cases that need further attention. The system is evaluated on a set of anterior-posterior chest images obtained using a linear slot-scanning digital X-ray machine. The classification results produced an area under the ROC of 0.782, averaged over all regions. © 2010 Springer-Verlag.
Computer-assisted sperm analysis systems: Morphometric aspects
(1995) Kruger T.
[No abstract available]
DETERMINATION OF SOURCE-POSITION TIMES IN INTRACAVITARY RADIOTHERAPY.
(1984) Pistorius S.; Groenewald W.A.
Prior to treatment using a single source remote afterloading system the source-position times must be determined. Initially the ideal but theoretical source-position times are calculated using a system of linear equations. In most cases however, one or more of the solutions are negative. Assuming that the best physical answer may be obtained if these negative values are held at zero, the matrices are reduced using linear regression techniques. The reduced set of equations is then used to solve for the new times. This procedure is repeated until no further negative solutions are obtained. Using these final values, dose distributions are plotted, and are found to correspond to within 5% of those initially requested.
Earlier age of onset of Alzheimer's disease in patients with both the transferrin C2 and apolipoprotein e-ε4 alleles
(2000) Van Rensburg S.J.; Potocnik F.C.V.; De Villiers J.N.P.; Kotze M.J.; Taljaard J.J.F.
The etiology of Alzheimer's disease is now known to be multifactorial. The genetic factors transferrin C2 (TfC2) and apolipoprotein E ε4 (ApoE-ε4) have both been associated with Alzheimer's disease (AD). Transferrin is the carrier protein for iron in the blood, while ApoE is involved with the transport and redistribution of lipids. In the present study, the polymerase chain reaction (PCR) method was used to determine the frequency of both TfC2 and ApoE-ε4 in 27 AD patients, 9 vascular dementia (VaD) patients, and 27 controls. Patients were diagnosed according to the criteria as set out in the 4th edition of the Diagnostic and Statistical Manual of the American Psychiatric Association (DSM-IV). The frequency of the TfC2 allele for the AD patients was 24%, while for the VaD patients it was 12.5%, which was not significantly different from the controls at 13%. The frequency of ApoE-ε4 for the AD patients was 44%, for the VaD patients 22%, and controls 17%. Of the 27 AD patients, 8 had both TfC2 and ApoE-ε4. The age of onset of the disease in these 8 patients (51-67 years, mean 60.25) was significantly earlier (p < 0.02) than in the remaining AD patients (49-76 years, mean 66.9). None of the VaD patients had both the TfC2 and the ApoE-ε4 alleles.
Efficacy and safety of pantoprazole 20 mg once daily treatment in patients with ulcer-like functional dyspepsia
(2008) Van Rensburg C.; Berghofer P.; Enns R.; Dattani I.D.; Maritz J.F.; Carro P.G.; Fischer R.; Schwan T.
Objective: To investigate the efficacy of pantoprazole 20 mg once daily (o.d.) in relieving epigastric pain associated with ulcer-like functional dyspepsia. Research design and methods: In this double-blind, placebo-controlled, multicentre study, patients experiencing ulcer-like functional dyspepsia, with epigastric pain as the predominant symptom, were randomised to receive pantoprazole 20 mg or placebo o.d. for 28 days. Primary endpoint was the complete relief (i.e. absence) from epigastric pain after 28 days' treatment. The odds ratio (OR) for pantoprazole/placebo and its 95% confidence intervals (CIs) were determined. Significant superiority of pantoprazole was concluded if the value 1.0 was above this interval. Results: Of 419 patients (intention-to-treat [ITT]) randomised to treatment, 207 received pantoprazole and 212 received placebo. Epigastric pain relief was achieved after 28 days' treatment in 55% of pantoprazole recipients and 45% of placebo recipients (per-protocol [PP]: 58% and 47%, respectively). Pantoprazole demonstrated statistically significant superiority compared with placebo in the ITT (OR: 0.68; 95% CI: 0.46-0.99) and PP populations (OR: 0.64; 95% CI: 0.42-0.98). Pantoprazole was more efficacious than placebo in relieving heartburn and acid regurgitation after 7, 14 and 28 days of treatment. The sum score of gastrointestinal symptoms after 28 days was statistically significantly lower in the pantoprazole than placebo group. Fewer patients receiving concomitant psychotropic medication experienced relief from epigastric pain than those not receiving such medication. Adverse events did not significantly differ between pantoprazole and placebo. Conclusions: Results of this study suggest that pantoprazole 20 mg is more efficacious than placebo, and is a well-tolerated treatment for relieving epigastric pain in patients with ulcer-like functional dyspepsia. Further research is needed to confirm these findings. © 2008 Informa UK Ltd.
Estimation of cardiac output using the Maxima breathing system
(1997) Miller D.M.; Greef J.; Wessels J.A.
[No abstract available]
Evaluation and management of renal injuries: Consensus statement of the renal trauma subcommittee
(2004) Santucci R.A.; Wessells H.; Bartsch G.; Descotes J.; Heyns C.F.; McAninch J.W.; Nash P.; Schmidlin F.
OBJECTIVE: To determine the optimal evaluation and management of renal injuries by review of the world's English-language literature on the subject. METHODS: A consensus conference convened by the World Health Organization and the Societé Internationale d'Urologie met to critically review reports of the diagnosis and treatment of renal trauma. The English-language literature about renal trauma was identified using Medline, and additional cited works not detected in the initial search obtained. Evidence-based recommendations for the diagnosis and management of renal trauma were made with reference to a five-point scale. RESULTS: There were many Level 3 and 4 citations, few Level 2, and one Level 1 which supported clinical practice patterns. Findings of nearly 200 reviewed citations are summarized. CONCLUSIONS: Published reports on renal trauma still rely heavily on expert opinion and single-institution retrospective case series. Prospective trials of the most significant issues, when possible, might improve the quality of evidence that dictates the behaviour of practitioners.
Functional myocardial imaging - DSE v. MPI: Round-table discussion
(1997) Ellman A.; Smith D.; Patel J.; Pennell D.
[No abstract available]
HIV and childhood tuberculosis: The way forward
(2004) Cotton M.F.; Schaaf H.S.; Hesseling A.C.; Madhi S.A.
Tuberculosis has been a major cause of morbidity and mortality in under-resourced communities. By causing progressive immunodeficiency, the human immunodeficiency virus (HIV) increases susceptibility to tuberculosis in an already vulnerable community. Similarities in clinical presentation and radiological appearance contribute to diagnostic difficulties, as even in the absence of HIV childhood tuberculosis is not easy to diagnose. The majority of studies thus far have been descriptive and often cross-sectional, but have defined the extent of this complex interaction. There is now a need to undertake prospective diagnostic, therapeutic and prevention studies. An emerging concern is how to integrate antiretroviral with anti-tuberculosis treatment and to explore whether lessons learned in tuberculosis can support antiretroviral therapy. Interactions between therapies for both conditions also need careful study.
Hyperhomocysteinemia - A risk factor for abruptio placentae
(1997) Owen E.P.; Human L.; Carolissen A.A.; Harley E.H.; Odendaal H.J.
[No abstract available]
Imaging of brain function using SPECT
(2004) Warwick, James M.
Single photon emission computed tomography (SPECT) is a technique widely used in nuclear medicine for the imaging of the many organs including the skeleton and heart, as well as for whole body imaging for the detection of tumors. The use of tracers of cerebral perfusion and more recently brain neurotransmitter systems has resulted in the development of a number of applications for brain SPECT in neurology and psychiatry. Indications have been established in cases of dementia, epilepsy, neurovascular disorders, Parkinsonism, and following minor head trauma. It also has the potential to be a valuable research tool for the study of in vivo brain function. In this paper an overview will be given of the principles underlying Brain SPECT, the performance of the procedure, and its applications as a diagnostic modality and research tool.

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