Genotype-dependent lifespan effects in peptone deprived Caenorhabditis elegans

Dietary restriction appears to act as a general non-genetic mechanism that can robustly prolong lifespan. There have however been reports in many systems of cases where restricted food intake either shortens, or does not affect, lifespan. Here we analyze lifespan and the effect of food restriction via deprived peptone levels on lifespan in wild isolates and introgression lines (ILs) of the nematode Caenorhabditis elegans. These analyses identify genetic variation in lifespan, in the effect of this variation in diet on lifespan and also in the likelihood of maternal, matricidal, hatching. Importantly, in the wild isolates and the ILs, we identify genotypes in which peptone deprivation mediated dietary restriction reduces lifespan. We also identify, in recombinant inbred lines, a locus that affects maternal hatching, a phenotype closely linked to dietary restriction in C. elegans. These results indicate that peptone deprivation mediated dietary restriction affects lifespan in C. elegans in a genotype-dependent manner, reducing lifespan in some genotypes. This may operate by a mechanism similar to dietary restriction

New approaches to selection system design in healthcare: The practical and theoretical relevance of a modular approach

This chapter presents a modular approach to healthcare selection system design. Contrary to the traditional holistic view on selection procedures, a modular approach highlights the components underlying selection procedures. Our framework identifies seven key design components of selection procedures (The stimulus format, contextualization, stimulus presentation consistency, the response format, response evaluation consistency, information source, and instructions) and reviews studies in the healthcare selection literature that compared the effect of these components on key selection outcomes. A modular approach allows (1) gaining insights into how the different components underlying selection procedures affect selection outcomes and (2) drawing conceptual similarities between components of different selection procedures. At a practical level, a modular approach permits developing a myriad of new selection procedures by "mixing and matching" different building blocks. We present two case studies and future research avenues to further illustrate these merits of a modular approach

Prevalence and Predictors of Tuberculosis Coinfection among HIV-Seropositive Patients Attending the Aminu Kano Teaching Hospital, Northern Nigeria

Background: The HIV/AIDS epidemic has been accompanied by a severe epidemic of tuberculosis (TB), although the prevalence of coinfection is largely unknown, especially in developing countries, including Nigeria. The aim of this study was to determine the prevalence and predictors of TB coinfection among HIV-seropositive Nigerians. Methods: The case files of HIV/AIDS patients attending Aminu Kano Teaching Hospital, Nigeria from January to December 2006 were reviewed. Results: A total of 1320 HIV/AIDS patients had complete records and were reviewed, among which 138 (10.5%) were coinfected with TB (95% CI, 8.9% to 12.2%). Pulmonary TB was diagnosed in 103 (74.6%) patients, among whom only 18 (17.5%) were sputum-positive. Fifty (36.2%) coinfected patients had some type of extrapulmonary TB (EPTB); 15 had both pulmonary TB and EPTB. Among the 35 patients with EPTB only, 20 (57.1%) had abdominal TB, 5 (14.3%) had TB adenitis, 5 (14.3%) had spinal TB, 3 (8.6%) were being monitored for tuberculous meningitis, and 1 (2.9%) each had renal TB and tuberculous adrenalitis. The highest prevalence of TB, 13.7% (n = 28), was seen among patients aged 41–50 years. TB coinfection was significantly associated with marital status, WHO clinical stage, and CD4 count. Marital status (OR, 2.1; 95% CI, 1.28–3.59; P = 0.04), WHO clinical stage at presentation (4.81; 1.42–8.34; P = 0.001), and baseline CD4 count (2.71; 1.51–6.21; P = 0.02) remained significant predictors after adjustment for confounding. Conclusions: The moderately high prevalence of TB among HIV-seropositive patients underscores the urgent need for strategies that lead to rapid identification and treatment of coinfection with active or latent TB