Browsing Research Output by Author "10986707 - Louw, Roan"
Now showing items 1-20 of 35
-
8-Oxo-7,8-dihydro-2’-deoxyguanosine, reactive oxygen species and ambulatory blood pressure in African and Caucasian men: the SABPA study
Mels, C.M.C.; Schutte, A.E.; Schutte, R.; Pretorius, P.J.; Smith, W.; Huisman, H.W.; Van der Westhuizen, F.H.; Fourie, C.M.T.; Van Rooyen, J.M.; Kruger, R.; Louw, R.; Malan, N.T.; Malan, L. (Taylor & Francis, 2014)Various studies indicate a relationship between increased oxidative stress and hypertension, resulting in increased DNA damage and consequent excretion of 8-oxo-7,8-dihydro-2’-deoxyguanosine (8-oxodG). The aim of this study ... -
Aberrant synthesis of ATP synthase resulting from a novel deletion in mitochondrial DNA in an African patient with progressive external ophthalmoplegia
Van der Westhuizen, Francois H.; Levanets, Oksana; Meissner-Roloff, Madelein; Louw, Roan; Smet, Joél (Springer, 2010)A young, adult, African male patient presented with progressive proximal muscle weakness, external ophthalmoplegia and ptosis, as well as cardiac conduction abnormalities resembling Kearns–Sayre syndrome (KSS). Magnetic ... -
The African prospective study on the early detection and identification of cardiovascular disease and hypertension (African-PREDICT): design, recruitment and initial examination
Schutte, Aletta E.; Uys, Aletta S.; Burger, Adele; Mels, Catharina M.C.; Kruger, Ruan; Smith, Wayne; Fourie, Carla M.T.; Botha, Shani; Lammertyn, Leandi; Van Rooyen, Johannes M.; Gafane-Matemane, Lebo F.; Mokwatsi, Gontse G.; Breet, Yolandi; Kruger, H. Salome; Van Zyl, Tertia; Pieters, Marlien; Zandberg, Lizelle; Louw, Roan; Moss, Sarah J.; Huisman, Hugo W. (Sage, 2019)Background: Globally hypertension is stabilising, but in sub-Saharan Africa the incidence of hypertension remains on an increase. Although this might be attributed to poor healthcare and ineffective antihypertensive ... -
Associations between reactive oxygen species, blood pressure and arterial stiffness in black South Africans: the SABPA study
Kruger, R.; Schutte, R.; Huisman, H.W.; Van Rooyen, J.M.; Malan, N.T.; Fourie, C.M.T.; Louw, R.; Van der Westhuizen, F.H.; Van Deventer, C.A.; Malan, L.; Schutte, A.E. (Springer Nature, 2012)Many mechanisms, including oxidative stress, contribute to hypertension. This study investigated the possible associations between oxidative stress, blood pressure and arterial stiffness in black South Africans. Ambulatory ... -
Blood glutathione and subclinical atherosclerosis in African men: the SABPA study
Schutte, Rudolph; Schutte, Aletta E.; Huisman, Hugo W.; Van Rooyen, Johannes M.; Malan, Nicolaas T.; Szabolcs, Péter; Fourie, Carla M.T.; Van der Westhuizen, Francois H.; Louw, Roan; Botha, Cindy A.; Malan, Leoné (Oxford Univ Press, 2009)Background: Sub-Saharan Africans face an increasing burden of hypertension and related cardiac and cerebrovascular morbidity and mortality, making the identification of factors leading to early vascular abnormalities ... -
Central systolic pressure and a nonessential amino acid metabolomics profile: the African prospective study on the early detection and identification of cardiovascular disease and hypertension
Mels, Catharina M.; Louw, Roan; Schutte, Aletta E.; Delles, Christian (Wolters Kluwer, 2019)Objectives: Early-life exposures to cardiovascular risk factors may manifest as early vascular ageing, a phenomenon to which black populations are more prone. The metabolome provides insight into the current state and ... -
Characterization of mtDNA variation in a cohort of South African paediatric patients with mitochondrial disease
Van der Walt, Elizna Magdalena; Louw, Roan; Van der Westhuizen, Francois H.; Smuts, Izelle; Taylor, Robert W. (Springer Nature, 2012)Mitochondrial disease can be attributed to both mitochondrial and nuclear gene mutations. It has a heterogeneous clinical and biochemical profile, which is compounded by the diversity of the genetic background. Disease-based ... -
The contribution of the C-824T tyrosine hydroxylase polymorphism to the prevalence of hypertension in a South African cohort: the SABPA study
Van Deventer, Cindy A.; Louw, Roan; Van der Westhuizen, Francois H.; Vorster, Chris B.; Malan, Leoné (Taylor & Francis, 2013)The C-824T single nucleotide polymorphism in the promoter region of the tyrosine hydroxylase gene has been associated with hypertension. It is well documented that African South Africans exhibit a higher prevalence of ... -
The dilemma of diagnosing coenzyme Q10 deficiency in muscle
Louw, Roan; Wilsenach, Kimmey-Li; Jonck, Lindi-Maryn; Schoonen, Maryke; Van der Westhuizen, Francois H. (Elsevier, 2018)Background Coenzyme Q10 (CoQ10) is an important component of the mitochondrial respiratory chain (RC) and is critical for energy production. Although the prevalence of CoQ10 deficiency is still unknown, the general consensus ... -
Disclosure of a putative biosignature for respiratory chain disorders through a metabolomics approach
Smuts, Izelle; Van der Westhuizen, Francois H.; Louw, Roan; Mienie, Lodewyk J.; Mason, Shayne; Koekemoer, Gerhard; Reinecke, Carolus J. (Springer, 2013)The diagnosis of respiratory chain deficiencies (RCDs) is complicated and the need for a diagnostic biomarker or biosignature has been widely expressed. In this study, the metabolic profile of a selected group of 29 ... -
The effect of temperature on the respiration and metabolism of the African burrowing scorpion (Opistophthalmus latimanus)
Van Aardt, Willie J.; Le Roux, Jacobus M.; Lindeque, Jeremie Z.; Mason, Shayne; Louw, Roan (Elsevier, 2016)It is well known that scorpions are highly adapted to thermal temperatures. However, little is known of the metabolic and respiration adaptations caused by temperature fluctuations in these animals. Therefore we used ... -
The effects of stirring, population levels and a potential anti-nematodal product on the respiration of second-stage juveniles of Meloidogyne incognita measured with different technology
Van Aardt, Willie J.; Fourie, Hendrika; Pretorius, Marthinus; Louw, Roan; Van Dyk, Hayley (Brill, 2016)The oxygen consumption rate (OCR) of Meloidogyne incognita second-stage juveniles (J2) was measured using polarographic oxygen sensor (POS) and fibre-optic oxygen sensor (FOS) technology. The effect of stirring speed on ... -
In vitro antioxidant, antimutagenic and genoprotective activity of Rosa roxburghii fruit extract
Van der Westhuizen, Francois H.; Janse van Rensburg, Catharina S.; Rautenbach, George S.; Loots, Du Toit; Huysamen, Cristal; Louw, Roan; Pretorius, Pieter J.; Erasmus, Elardus; Marnewick, Jeanine L. (Wiley, 2008)The antioxidant properties of the fruit of the Rosa roxburghii (RR) plant have been associated with several putative health promoting effects. The possible cytotoxic, mutagenic/antimutagenic and genotoxic effects of RR ... -
The involvement of metallothioneins in mitochondrial function and disease
Lindeque, J.Z.; Levanets, O.; Louw, R.; Van der Westhuizen, F.H. (Bentham Science, 2010)Mitochondrial oxidative phosphorylation deficiency is accompanied by various down-stream, adaptive responses which play a key role in the varied phenotypes observed when mitochondrial dysfunction occurs. These responses ... -
Left ventricular mass and urinary metabolomics in young black and white adults: the African-PREDICT study
De Beer, Dalene; Mels, Catharina M.C.; Schutte, Aletta E.; Louw, Roan; Kruger, Ruan (Elsevier, 2020)Background and aims Increased left ventricular mass is an independent predictor for cardiovascular events, and shown to be higher in black than white populations. To gain a better understanding of early factors contributing ... -
Metabolic and glutathione redox markers associated with brain-derived neurotrophic factor in depressed African men and women: evidence for counterregulation?
Harvey, B.H.; Hamer, M.; Louw, R.; Van der Westhuizen, F.H.; Malan, L. (Karger, 2013)Background: Major depression is associated with evidence for metabolic and redox imbalance and also with reports of lower serum levels of brain-derived neurotrophic factor (BDNF). However, the relationship between these ... -
Metabolomics of mitochondrial disease
Esterhuizen, Karien; Van der Westhuizen, Francois H.; Louw, Roan (Elsevier, 2017)Mitochondrial disease (MD) diagnostics and disease progression investigations have traditionally relied very little on metabolic data, due to a lack of biomarker sensitivity and specificity. The recent drive to find novel, ... -
Metabolomics of Ndufs4−/− skeletal muscle: adaptive mechanisms converge at the ubiquinone-cycle
Terburgh, Karin; Lindeque, Zander; Mason, Shayne; Van der Westhuizen, Francois; Louw, Roan (Elsevier, 2019)Leigh syndrome is one of the most common childhood-onset neurometabolic disorders resulting from a primary oxidative phosphorylation dysfunction and affecting mostly brain tissues. Ndufs4−/− mice have been widely used to ... -
Metabolomics of urinary organic acids in respiratory chain deficiencies in children
Reinecke, Carolus J.; Koekemoer, Gerhard; Van der Westhuizen, Francois H.; Louw, Roan; Lindeque, Jeremie Z.; Mienie, Lodewyk J.; Smuts, Izelle (Springer, 2012)Metabolomic analysis of the urinary organic acids from 39 selected children with defined respiratory chain deficiencies (RCDs) was performed using untargeted gas chromatography–mass spectrometry, revealing the presence ... -
Metabolomics reveals the depletion of intracellular metabolites in HepG2 cells after treatment with gold nanoparticles
Lindeque, Jeremie Zander; Matthyser, Alnari; Mason, Shayne; Louw, Roan; Taute, Cornelius Johannes Francois (Taylor & Francis, 2018)Studies on the safety of gold nanoparticles (GNPs) are plentiful due to their successful application in drug delivery and treatment of diseases in trials. Cytotoxicity caused by GNPs has been studied on the physiological ...