Paul van Helden

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BACKGROUND Data from Kwazulu Natal, South Africa, suggest that almost all patients with extensively drug-resistant (XDR) tuberculosis are HIV-positive, with a fatal outcome. Since, there are few data for the treatment-related outcomes of XDR tuberculosis in settings with a high HIV prevalence, we investigated the associations of these diseases in such(More)
Admixed populations present unique opportunities to discover the genetic factors underlying many multifactorial diseases. The geographical position and complex history of South Africa has led to the establishment of the unique admixed population known as the South African Coloured. Not much is known about the genetic make-up of this population, and the(More)
We have validated the association of two genes on chromosome 20q13.31–33 with tuberculosis susceptibility. A previous genome-wide linkage study performed by Cooke et al identified the genes melanocortin-3-receptor (MC3R) and cathepsin Z (CTSZ) as possible candidates in tuberculosis susceptibility. MC3R has been implicated in obesity studies and is known to(More)
1 SA MRC Centre for TB Research, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, 8000 2 Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY 11794 3 Analytic and Translational Genetics(More)
Although microsatellite typing is the dominant method in genome research and indirect gene diagnosis, precise relationships of exonic and adjacent simple repeat polymorphisms are not known. We investigated exon 2 sequences of HLA-DRB1 genes and their neighbouring (GT)n(GA)m repeats including the intervening single copy spacer. DRB1 is the most polymorphic(More)
Susceptibility to tuberculosis (TB) in mice has recently been attributed to the Ipr1 gene. Polymorphisms in the human homologue, SP110, have been investigated in various populations with only one study finding an association with TB susceptibility. We investigated eight SP110 polymorphisms in a South African population, including two novel polymorphisms. No(More)
The aim of the study presented here was to determine the minimal inhibitory concentration of isoniazid for strains of isoniazid-resistant or multidrug-resistant Mycobacterium tuberculosis isolated from children in the Western Cape Province of South Africa. During the period March 2003–October 2005, 45 INH-resistant M. tuberculosis isolates (21 also(More)
Evaluation of early bactericidal activity (EBA) by the determination of a fall in viable colony-forming units (CFU) of Mycobacterium tuberculosis in sputum is a first step in the clinical study of new antituberculosis agents. The time to detection (TTD) of growth in liquid media is more sensitive and could substitute for CFU counting on solid media.(More)
Classic studies of tuberculosis (TB) revealed morphologic evidence of considerable heterogeneity of macrophages (MØs), but the functional significance of this heterogeneity remains unknown. We have used newly available specific antibodies for selected membrane and secretory molecules to examine the phenotype of MØs in situ in a range of South African(More)
Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa. Agricultural Research Council, Irene, South Africa. Division of Molecular Biology and Human Genetics, University of Stellenbosch, South Africa. Department of Environmental Science Policy and Management, University of California at Berkeley,(More)