Cytokine Profile and Clinical Correlates in HIV-Exposed Infants with Severe (Hypoxic) Pneumonia

Introduction. Severe pneumonia in infants who are HIV-infected is a common problem in many parts of the developing world; especially sub-Saharan Africa. What has been missing from previous studies of severe pneumonia in HIV-infected infants; however; is a description of the host inflammatory response and cytokine/chemokine profile that accompanies this disease. Objective. To describe the cytokine profiles associated with severe hypoxic pneumonia in HIV-infected infants Methods. In a cohort of HIV-infected children diagnosed clinically with severe hypoxic pneumonia; paired serum and sputum cytokines were tested. A control group of HIV-infected children with bronchiectasis contributed matching controls.Results. A total of 100 infants (mean age 2.8 months) with a clinical diagnosis of severe hypoxic pneumonia were included in this study. IP-10 was markedly elevated in both sputum (mean 560.77pg/ml) and serum (mean 9091.14pg/ml); while IP-10 was elevated in serum (mean 39.55 pg/ml); with both these cytokines being significantly higher than in stable children with HIV-related bronchiectasis. Conclusion. This study of HIV-infected infants with severe hypoxic pneumonia suggests that IL-10 and IP-10 are associated with more severe lung disease. However; further investigation of this association is required

Potassium-Uptake Systems of Mycobacterium tuberculosis: Genomic and Protein Organization and Potential Roles in Microbial Pathogenesis and Chemotherapy

Mycobacterium tuberculosis (MTB) is a formidable microbial pathogen which uses multiple mechanisms to subvert host immune defences. These include the effective; protective barrier presented by the outer waxy coat; intracellular concealment from host defences; and the ability to enter a prolonged; dormant phase in the infected host. Priority strategies to combat the scourge of TB include the identification of novel and selective targets on/in MTB which are amenable to pharmacological or immune-mediated control. Because they are structurally different from their counterparts in eukaryotic cells and are likely to be essential for survival and growth; the major K+ transporters of MTB represent alternative and novel targets for drug and vaccine design. These K+-uptake systems of MTB are the primary focus of this review; with particular emphasis on their genomic and protein structures; properties and functions; and potential roles in intracellular survival

Augmentation of the acute phase response in vitamin C-supplemented ultramarathoners

Objective. To investigate the effects of vitamin C (VC) supplementation on the alterations in systemic markers of inflammation as a result of participation in a 90 km down run from Pietermaritzburg to Durban in 29 subjects who completed the 1999 Comrades Marathon. Interventions. Runners were divided into groups receiving 500 mg/day VC (VC500; N = 10); 1 500 mg/day VC (VC1500; N = 12) or placebo (P; N = 7) for 7 days before the race; on the day of the race; and for 2 days following completion. Main outcome measures. Each subject recorded dietary intake before; during and after the race and provided 35 ml blood samples 15 - 18 hours before the race; immediately post race; 24 hours post race and 48 hours post race. These were analysed for full blood count; vitamins A; C and E; glucose; C-reactive protein (CRP); amyloid A; interleukin-6 (IL-6) and interleukin-8 (IL-8) concentrations. All post race concentrations were adjusted for plasma volume changes. Results. Analyses of dietary intakes and blood glucose and anti-oxidant status on the day preceding the race and the day of the race excluded carbohydrate intake or plasma vitamins E and A as significant confounders in the study. Mean pre-race concentrations of serum vitamin C in VC500 and VC1500 groups (128 - 10.2 and 153 - 10.2 mol/l) were significantly higher (p 0.01) than in the P group (83 - 10.8 mol/l) and confirmed the additional dietary VC intake of both groups. Serum CRP concentrations were significantly higher (p 0.05) in the VC500 group than in the VC1500 and P groups. This finding was supported by similar trends in serum amyloid A; plasma IL-6 and IL-8. When the data from the two VC groups were pooled and the vitamin intake in the placebo (N 500 mg per day

Some aspects of sexual behaviour and the potential demographic impact of AIDS in developing countries

This review examines recent research on the influence of heterogeneity in sexual behaviour on the transmission dynamics of the human immunodeficiency virus (HIV); the aetiological agent of AIDS. Attention is focused on the potential demographic impact of AIDS in developing countries and how this is influenced by the structure of networks of sexual contacts (who mixes with whom); age-dependency in rates of sexual partner change and differences in the ages of female and male sexual partners. Analyses based on the construction of simple and complex mathematical models of the spread of HIV via heterosexual contact serve as a template for the interpretation of observed pattern and as a guide to the major aspects of sexual behaviour that govern the transmission dynamics of the virus. It is argued that much greater attention must be addressed to the quantification of patterns of sexual behaviour in defined communities; despite the many practical problems that surround data collection and interpretation