Browsing by Author "Roberts, Teri"

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    An evaluation of commercial fluorescent bead-based luminex cytokine assays
    (Public Library of Science, 2008-07-02) Siawaya, Joel Fleury Djoba; Roberts, Teri; Babb, Chantal; Black, Gillian; Golakai, Hawa Jande; Stanley, Kim; Bapela, Nchinya Bennedict; Hoal, Eileen; Parida, Shreemanta; Van Helden, Paul; Walzl, Gerhard
    The recent introduction of fluorescent bead-based technology, allowing the measurement of multiples analytes in a single 25-50 μl sample has revolutionized the study of cytokine responses. However, such multiplex approaches may compromise the ability of these assays to accurately measure actual cytokine levels. This study evaluates the performance of three commercially available multiplex cytokine fluorescent bead-based immunoassays (Bio-Rad's Cytokine 17-piex kit; LINCO Inc's 29-plex kit; and RnD System's Fluorokine-Multi Analyte Profiling (MAP) base kit A and B). The LINEO Inc kit was found to be the most sensitive assay for measuring concentrations of multiple recombinant cytokines in samples that had been spiked with serial dilutions of the standard provided by the manufacturer, followed respectively by the RnD Fluorokine-(MAP) and Bio-Rad 17-plex kits. A positive correlation was found in the levels of IFN-γ measured in antigen stimulated whole blood culture supernatants by the UNCO inc 29-plex, RnD Fluorokine-(MAP) and RnD system IFN-γ Quantikine ELISA kits across a panel of controls and stimulated samples. Researchers should take the limitation of such multiplexed assays into account when planning experiments and the most appropriate use for these tests may currently be as screening tools for the selection of promising markers for analysis by more sensitive techniques. © 2008 Djoba Siawaya et al.
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    Pleural tuberculosis in patients with early HIV infection is associated with increased TNF-alpha expression and necrosis in granulomas
    (Public Library of Science, 2009-01-19) Bezuidenhout, Juanita; Roberts, Teri; Muller, Liesel; Van Helden, Paul; Walzl, Gerhard
    Although granulomas may be an essential host response against persistent antigens, they are also associated with immunopathology. We investigated whether HIV co-infection affects histopathological appearance and cytokine profiles of pleural granulomas in patients with active pleural tuberculosis (TB). Granulomas were investigated in pleural biopsies from HIV positive and negative TB pleuritis patients. Granulomas were characterised as necrotic or non-necrotic, graded histologically and investigated for the mRNA expression of IL-12, IFN-γ, TNF-α and IL-4 by in situ hybridisation. In all TB patients a mixed Th1/Th2 profile was noted. Necrotic granulomas were more evident in HIV positive patients with a clear association between TNF-α and necrosis. This study demonstrates immune dysregulation which may include TNF-α-mediated immunopathology at the site of disease in HIV infected pleural TB patients. © 2009 Bezuidenhout et al.
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    Served versus actual nutrient intake of hospitalized patients with tuberculosis
    (Stellenbosch : University of Stellenbosch, 2003-12) Roberts, Teri; Labadarios, D.; Herselman, M.; University of Stellenbosch. Faculty of Health Sciences. Dept. of Interdisciplinary Health Sciences. Human Nutrition.
    ENGLISH ABSTRACT: Objectives: To assess whether actual nutrient intake of hospitalized patients with tuberculosis differed from that served by the hospital and from that required according to current recommendations. Design: Descriptive, cross-sectional study. Setting: Brooklyn Chest Hospital in Brooklyn, Cape Town, the Western Cape, South Africa. Subjects: Thirty patients, 23 male, seven female, with pulmonary tuberculosis, from Brooklyn Chest Hospital were enrolled in the study. Outcome measures: Assessment included dietary intake in order to calculate energy and nutrient intake and requirements, and height and weight at the beginning of the study in order to calculate BMI. Results: Patients were receiving and consuming sufficient macronutrients with the exception of protein in all patients, and micronutrients with the exceptions of calcium, iodine, folate and vitamin E in all patients, betacarotene, vitamin C and vitamin D in male patients, and selenium and pantothenate in female patients. Actual intake consumed in the hospital did not differ from that served by the hospital in the case of male patients, with the exception of iodine, however, due to significant plate wastage by female patients, consumed intake was less than that served by the hospital, with the exceptions of vitamin C and vitamin K. A total of 52% of the male patients, and 71% of the female patients, were normally nourished, according to their BMI. The remainder of the patients were mildly to severely malnourished on the basis of their BMI. Conclusions: According to current recommendations, the patients institutionalized at Brooklyn Chest Hospital for tuberculosis were receiving inadequate protein and selected micronutrients (calcium, iodine, folate and vitamin E in all patients, beta-carotene, vitamin C and vitamin D in male patients, and selenium and pantothenate in female patients). Therefore intervention programs, which serve as an adjunct to anti-tuberculosis therapy, should be introduced in order to rectify inadequate nutrient intake and to target malnourished patients.
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    The characterisation of immune responses during Mycobacterium tuberculosis infection
    (Stellenbosch : Stellenbosch University, 2007) Roberts, Teri; Stellenbosch University. Faculty of . Dept. of .