Role of bacille Calmette-Guérin in preventing tuberculous infection.

SETTING: Rural community in South India. OBJECTIVE: To determine the role of bacille Calmette-Guérin (BCG) in preventing tuberculous infection in children. DESIGN: A prevalence survey was undertaken in 1999-2001 in a representative rural population in Tiruvallur District in South India using cluster sampling. Tuberculin testing was performed among all children aged <15 years, and all adults aged 15 years were questioned about chest symptoms and underwent radiography, followed by sputum examinations, if indicated. RESULTS: In children living in households with a tuberculosis case, the proportion with evidence of tuberculous infection was 35.5% of 200 in the absence of a BCG scar and 27.0% of 100 in its presence, a reduction of 24% (P = 0.14). In very young children (age <5 years), the corresponding proportions were 29.1% of 55 and 11.9% of 42, a reduction of 59%; the difference was statistically significant (P = 0.048). CONCLUSION: There is a possible role for BCG in preventing tuberculous infection in very young children

Global patterns and drivers of ecosystem functioning in rivers and riparian zones

River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth's biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constraints toward the poles and greater roles for other environmental drivers (e.g., nutrient loading) toward the equator. These results and data set the stage for unprecedented "next-generation biomonitoring" by establishing baselines to help quantify environmental impacts to the functioning of ecosystems at a global scale.peerReviewe

Risk of periprosthetic fracture after anterior femoral notching:a 9-year follow-up of 200 total knee arthroplasties

Background Notching of the anterior femoral cortex in distal femoral fractures following TKR has been observed clinically and studied biomechanically. It has been hypothesized that femoral notching weakens the cortex of the femur, which can predispose to femoral fractures in the early postoperative period. We examined the relationship between notching of the anterior femoral cortex during total knee replacement (TKR) and supracondylar fracture