Background: Adverse drug reactions and lack of therapeutic efficacy associated with currently prescribed pharmacotherapeutics may be attributed, in part, to inter-individual variability in drug metabolism. Studies on the pharmacogenetics of Cytochrome P450 (CYP) enzymes offer insight into this variability. The objective of this study was to compare the AmpliChip CYP450 Test® (AmpliChip) to alternative genotyping platforms for phenotype prediction of CYP2C19 and CYP2D6 in a representative cohort of the South African population.
View Article and Find Full Text PDFIntroduction: The revised shared epitope (SE) concept in rheumatoid arthritis (RA) is based on the presence (S) or absence (X) of the SE RAA amino acid motif at positions 72 to 74 of the third hypervariable region of the various human leucocyte antigen (HLA)-DRB1 alleles. The purpose of this study was to investigate SE subtypes on the basis of the American College of Rheumatology 1987 revised criteria for the classification of RA in a cohort of South African RA patients (n = 143) and their association with clinical and circulating biomarkers of disease activity (autoantibodies, acute phase reactants and cytokines).
Methods: Genomic DNA was analysed using high-resolution recombinant sequence-specific oligonucleotide PCR typing of the HLA-DRB1 allele.
Our objective was to analyse the relationship between circulating cytokines, autoantibodies, acute phase reactants, and disease activity in DMARDs-naïve rheumatoid arthritis (RA) patients (n = 140). All cytokines were significantly higher in the RA cohort than in healthy controls. Moderate-to-strong positive intercorrelations were observed between Th1/Th2/macrophage/fibroblast-derived cytokines.
View Article and Find Full Text PDFBackground/objectives: To measure reactive oxidant production and the decline in antioxidant potential in commercially available, irradiated parenteral nutrition (PN) solutions and the effect that these have on oxidant production in patients in the intensive care unit.
Subjects And Methods: Vitamin E and malondialdehyde in irradiated and nonirradiated commercially available, PN solutions were measured. The PBN (alpha-phenyl-n-test-butylnitrone (PBN) spin trap was used to measure free radicals and TEMPOL (2,2,6,6-tetramethyl-4-hydroxy-piperidine-oxyl) was used to assess antioxidant capacity.
The primary objective of this study was to investigate the effects of cobalt (Co(2 +)), palladium (Pd(2 +)), platinum (Pt(4 +)) and vanadium (V(2 +), V(3 +), V(4 +) and V(5 +)) on the ability of the neutrophil chemoattractants C5a and IL-8, as well as the pneumococcal toxin, pneumolysin, to activate human neutrophils in vitro. Neutrophil activation was determined according to the magnitude of the increase in cytosolic Ca(2 +) concentrations using a fura-2/AM-based, spectrofluorimetric procedure, as well as by a chemotaxis assay using modified Boyden chambers. In initial screening studies, in which the metals were used at a fixed concentration of 25 mu M, the Ca(2 +)-mobilizing interactions of C5a, IL-8, and pneumolysin were unaffected by exposure to Co(2 +), Pt(4 +) and V(2 + - 5 +).
View Article and Find Full Text PDFFree Radic Biol Med
January 2006
This study was undertaken to investigate the effects of vanadium in the +2, +3, +4, and +5 valence states on superoxide generation, myeloperoxidase (MPO) activity, and hydroxyl radical formation by activated human neutrophils in vitro, using lucigenin-enhanced chemiluminescence (LECL), autoiodination, and electron spin resonance with 5,5-dimethyl-l-pyrroline N-oxide as the spin trap, respectively. At concentrations of up to 25 microM, vanadium, in the four different valence states used, did not affect the LECL responses of neutrophils activated with either the chemoattractant, N-formyl-l-methionyl-l-leucyl-l-phenylalanine (1 microM), or the phorbol ester, phorbol 12-myristate 12-acetate (25 ng/ml). However, exposure to vanadium in the +2, +3, and +4, but not the +5, valence states was accompanied by significant augmentation of hydroxyl radical formation by activated neutrophils and attenuation of MPO-mediated iodination.
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