Ethnicity, hypertension, coronary heart disease and renal diseases in South Africa

This paper reviews the impact of race and environment upon hypertension, coronary heart disease and renal diseases in South Africa. Inequalities of socioeconomic status, lifestyle, and access to South African health care have produced striking differences in the prevalence and complications of hypertension. Coronary heart disease is 'epidemic' in the white and Indian population and is still relatively uncommon in blacks. There are different histological patterns of glomerulonephritis among the racial groups, which may lead to end-stage renal disease. Hypertension is an important cause of end-stage renal disease in the black population whilst analgesic nephropathy is important in the white population. Efforts are now being made to comprehend these daunting realities and to minimize the inequalities.     

Two different reactions involved in the primer/template-independent polymerization of dATP and dTTP by Taq DNA polymerase

We previously isolated a 41-kDa early antigen of human herpesvirus 6 (HHV-6), which exhibited nuclear localization and DNA-binding activity (Agulnick et al., 1993). In this study, we observed that a 110-kDa protein was coimmunoprecipitated with p41 from HHV-6-infected cells by an anti-p41 antibody. This 110-kDa protein was identified as the HHV-6 DNA polymerase (Pol-6) by an antibody raised against the N terminus of Pol-6. Reciprocal immunoprecipitation and Western blot analyses confirmed that p41 complexes with Pol-6 in HHV-6-infected cells. In addition, both p41 and Pol-6 were expressed in vitro and shown to form a specific complex. An in vitro DNA synthesis assay using primed M13 single-stranded DNA template demonstrated that p41 not only increased the DNA synthesis activity of Pol-6 but also allowed Pol-6 to synthesize DNA products corresponding to full-length M13 template (7249 nucleotides). By contrast, Pol-6 alone could only synthesize DNA of <100 nucleotides. The functional interaction between Pol-6 and p41 appears to be specific because they could not be physically or functionally substituted in vitro by their herpes simplex virus 1 homologues. Moreover, as revealed by mutational analysis, both the N and C termini of Pol-6 contribute to its binding to p41. In the case of p41, the N terminus is required for increasing DNA synthesis but not binding to Pol-6, whereas the C terminus is totally dispensable.     

Control of phase composition in hydroxyapatite/tetracalcium phosphate biphasic thin coatings for biomedical applications

Biphasic calcium phosphates comprising well-controlled mixtures of nonresorbable hydroxyapatite and other resorbable calcium phosphate phases often exhibit a combination of enhanced bioactivity and mechanical stability that is difficult to achieve in single-phase materials. This makes these biphasic bioceramics promising substrate materials for applications in bone tissue regeneration and repair. In this paper we report the synthesis of highly crystalline, biphasic coatings of hydroxyapatite/tetracalcium phosphate with control over the weight fraction of the constituent phases. The coatings were produced by pulsed laser deposition using ablation targets of pure crystalline hydroxyapatite. The fraction of tetracalcium phosphate phase in the coatings was controlled by varying the substrate temperature and the partial pressure of water vapor in the deposition chamber. A systematic study of phase composition in the hydroxyapatite/tetracalcium phosphate biphasic coatings was performed with X-ray diffraction. Tetracalcium phosphate in the coatings obtained at high substrate temperature is not formed by partial conversion of previously deposited hydroxyapatite. Instead, it is produced by nucleation and growth of tetracalcium phosphate itself from the ablation products of the hydroxyapatite target or by accretion of tetracalcium phosphate grains formed during ablation. This finding was confirmed by formation of calcium oxide, not tetracalcium phosphate, after annealing of pure hydroxyapatite coatings at high temperatures of 700–850∘C.     

Improvement of nutritional value of common beans (Phaseolus vulgaris) by autoclaving or extraction

Larval weight of Tribolium castaneum was used to evaluate six varieties of common beans (Phaseolus vulgaris). Beans incorporated into test diets were raw, autoclaved, or extracted with either water or 80% methanol. All treatments improved the nutritional quality of beans when compared to raw beans. The bean extracts were growth depressing. In another study heating of the freeze-dried water extract of black beans improved its nutritive value but not of the methanol extract. Tribolium castaneum larvae may be used to evaluate the nutritional quality of Phaseolus vulgaris and different bean treatments.