Sources of pre-analytical variations in yield of DNA extracted from blood samples: analysis of 50,000 DNA samples in EPIC.

The European Prospective Investigation into Cancer and nutrition (EPIC) is a long-term, multi-centric prospective study in Europe investigating the relationships between cancer and nutrition. This study has served as a basis for a number of Genome-Wide Association Studies (GWAS) and other types of genetic analyses. Over a period of 5 years, 52,256 EPIC DNA samples have been extracted using an automated DNA extraction platform. Here we have evaluated the pre-analytical factors affecting DNA yield, including anthropometric, epidemiological and technical factors such as center of subject recruitment, age, gender, body-mass index, disease case or control status, tobacco consumption, number of aliquots of buffy coat used for DNA extraction, extraction machine or procedure, DNA quantification method, degree of haemolysis and variations in the timing of sample processing. We show that the largest significant variations in DNA yield were observed with degree of haemolysis and with center of subject recruitment. Age, gender, body-mass index, cancer case or control status and tobacco consumption also significantly impacted DNA yield. Feedback from laboratories which have analyzed DNA with different SNP genotyping technologies demonstrate that the vast majority of samples (approximately 88%) performed adequately in different types of assays. To our knowledge this study is the largest to date to evaluate the sources of pre-analytical variations in DNA extracted from peripheral leucocytes. The results provide a strong evidence-based rationale for standardized recommendations on blood collection and processing protocols for large-scale genetic studies.

Differential in vitro activity of the DNA topoisomerase inhibitor idarubicin against Trypanosoma rangeli and Trypanosoma cruzi

In this study the effect of eight DNA topoisomerase inhibitors on the growth Trypanosoma rangeli epimastigotes in cell culture was investigated. Among the eight compounds tested, idarubicin was the only compound that displayed promising trypanocidal activity with a half-maximal growth inhibition (GI50) value in the sub-micromolar range. Fluorescence-activated cell sorting analysis showed a reduction in DNA content in T. rangeli epimastigotes when treated with idarubicin. In contrast to T. rangeli, against Trypanosoma cruzi epimastigotes idarubicin was much less effective exhibiting a GI50 value in the mid-micromolar range. This result indicates that idarubicin displays differential toxic effects in T. rangeli and T. cruzi. Compared with African trypanosomes, it seems that American trypanosomes are generally less susceptible to DNA topoisomerase inhibitors.

Comparison of two rapid tests for anti-phenolic glycolipid-I serology in Brazil and Nepal

The diagnosis of leprosy continues to be based on clinical symptoms and early diagnosis and treatment are critical to preventing disability and transmission. Sensitive and specific laboratory tests are not available for diagnosing leprosy. Despite the limited applicability of anti-phenolic glycolipid-I (PGL-I) serology for diagnosis, it has been suggested as an additional tool to classify leprosy patients (LPs) for treatment purposes. Two formats of rapid tests to detect anti-PGL-I antibodies [ML immunochromatography assay (ICA) and ML Flow] were compared in different groups, multibacillary patients, paucibacillary patients, household contacts and healthy controls in Brazil and Nepal. High ML Flow intra-test concordance was observed and low to moderate agreement between the results of ML ICA and ML Flow tests on the serum of LPs was observed. LPs were "seroclassified" according to the results of these tests and the seroclassification was compared to other currently used classification systems: the World Health Organization operational classification, the bacilloscopic index and the Ridley-Jopling classification. When analysing the usefulness of these tests in the operational classification of PB and MB leprosy for treatment and follow-up purposes, the ML Flow test was the best point-of-care test for subjects in Nepal and despite the need for sample dilution, the ML ICA test yielded better performance among Brazilian subjects. Our results identified possible ways to improve the performance of both tests.

"Blade Runner" o la pregunta por la dignidad humana

Al pensar en la relación entre el fundamento de la dignidad humana y la resolución de algunos problemas bioéticos, me vino a la cabeza Blade Runner, la película de Ridley Scott basada en un relato de Philip K. Dickque lleva el extravagante título de ¿Sueñan los androides con ovejas eléctricas? (extravagante si vemos la película pero no tanto si leemos el relato)...

Agricultural phosphorus and water quality : sources, transport and management

Selostus: Maatalous, fosfori ja veden laatu: alkuperä, kulkeutuminen ja vesistökuormituksen hallinta