Low uptake of antiretroviral therapy after admission with human immunodeficiency virus and tuberculosis in KwaZulu-Natal, South Africa.

A prospective cohort study was conducted among human immunodeficiency virus (HIV) infected in-patients with tuberculosis (TB) or other opportunistic infections (OIs) in South Africa to estimate subsequent antiretroviral therapy (ART) uptake and survival

Global collaborative networks on meta-analyses of randomized trials published in high impact factor medical journals: a social network analysis

BackgroundResearch collaboration contributes to the advancement of knowledge by exploiting the results of scientific efforts more efficiently, but the global patterns of collaboration on meta-analysis are unknown. The purpose of this research was to describe and characterize the global collaborative patterns in meta-analyses of randomized trials published in high impact factor medical journals over the past three decades.MethodsThis was a cross-sectional, social network analysis. We searched PubMed for relevant meta-analyses of randomized trials published up to December 2012. We selected meta-analyses (including at least randomized trials as primary evidence source) published in the top seven high impact factor general medical journals (according to Journal Citation Reports 2011): The New England Journal of Medicine, The Lancet, the BMJ, JAMA, Annals of Internal Medicine, Archives of Internal Medicine (now renamed JAMA Internal Medicine), and PLoS Medicine. Opinion articles, conceptual papers, narrative reviews, reviews without meta-analysis, reviews of reviews, and other study designs were excluded.ResultsOverall, we included 736 meta-analyses, in which 3,178 authors, 891 institutions, and 51 countries participated. The BMJ was the journal that published the greatest number of articles (39%), followed by The Lancet (18%), JAMA (15%) and the Archives of Internal Medicine (15%). The USA, the UK, and Canada headed the absolute global productivity ranking in number of papers. The 64 authors and the 39 institutions with the highest publication rates were identified. We also found 82 clusters of authors (one group with 55 members and one group with 54 members) and 19 clusters of institutions (one major group with 76 members). The most prolific authors were mainly affiliated with the University of Oxford (UK), McMaster University (Canada), and the University of Bern (Switzerland).ConclusionsOur analysis identified networks of authors, institutions and countries publishing meta-analyses of randomized trials in high impact medical journals. This valuable information may be used to strengthen scientific capacity for collaboration and to help to promote a global agenda for future research of excellence

Trypanosoma cruzi Gene Expression in Response to Gamma Radiation

Trypanosoma cruzi is an organism highly resistant to ionizing radiation. Following a dose of 500 Gy of gamma radiation, the fragmented genomic DNA is gradually reconstructed and the pattern of chromosomal bands is restored in less than 48 hours. Cell growth arrests after irradiation but, while DNA is completely fragmented, RNA maintains its integrity. In this work we compared the transcriptional profiles of irradiated and non-irradiated epimastigotes at different time points after irradiation using microarray. In total, 273 genes were differentially expressed; from these, 160 were up-regulated and 113 down-regulated. We found that genes with predicted functions are the most prevalent in the down-regulated gene category. Translation and protein metabolic processes, as well as generation of precursor of metabolites and energy pathways were affected. In contrast, the up-regulated category was mainly composed of obsolete sequences (which included some genes of the kinetoplast DNA), genes coding for hypothetical proteins, and Retrotransposon Hot Spot genes. Finally, the tyrosyl-DNA phosphodiesterase 1, a gene involved in double-strand DNA break repair process, was up-regulated. Our study demonstrated the peculiar response to ionizing radiation, raising questions about how this organism changes its gene expression to manage such a harmful stress

Effect of chronic mitral valve damage on activity of pulmonary rapidly adapting receptors in the rabbit

The effects of acute pulmonary venous congestion on the activity of rapidly adapting receptors (RARs) were determined in intact (control and sham-operated) rabbits and in rabbits 6 and 12 weeks after surgical destruction of the mitral valve.Destruction of the mitral valve increased the mean left atrial pressure (LAP) by approximately 2·6 and 3·8 mmHg, 6 and 12 weeks after surgery, respectively. These changes were accompanied by significant increases in left ventricular weight. The effect of acute increments in LAP on RAR activity was examined against this background of chronic pulmonary venous congestion.In intact control and sham-operated animals RAR activity increased from 48·8 ± 0·9 to 83·5 ± 3·6 and 121·1 ± 4·7 action potentials min−1 when the LAP was raised by 5 and 10 mmHg, respectively, above control values. Six weeks after surgery only 40 % of RARs were activated in this way.In animals maintained for 12 weeks after surgery, RAR activity at LAPs of 6·6 ± 1·2 (control), 11·6 ± 1·2 and 16·6 ± 1·2 (mmHg) were 35·5 ± 2·3, 33·8 ± 14·4 and 34·0 ± 3·4 action potentials min−1, respectively. These changes were statistically not significant.Slowly adapting receptors (SARs) in the lung showed a small but statistically significant increase in activity when the left atrial pressure was acutely elevated in both intact and mitral valve damaged animals.It is concluded that chronic pulmonary venous congestion resulting from destruction of the mitral valve attenuates the ability of RARs to respond to acute moderate elevations of LAP