Recent advances in understanding hypertension development in sub-Saharan Africa

Consistent reports indicate that hypertension is a particularly common finding in black populations. Hypertension occurs at younger ages and is often more severe in terms of blood pressure levels and organ damage than in whites, resulting in a higher incidence of cardiovascular disease and mortality. This review provides an outline of recent advances in the pathophysiological understanding of blood pressure elevation and the consequences thereof in black populations in Africa. This is set against the backdrop of populations undergoing demanding and rapid demographic transition, where infection with the Human Immunodeficiency Virus predominates, and where under and over-nutrition coexist. Collectively, recent findings from Africa illustrate an increased lifetime risk to hypertension from foetal life onwards. From young ages black populations display early endothelial dysfunction, increased vascular tone and reactivity, microvascular structural adaptions, as well as increased aortic stiffness resulting in elevated central and brachial blood pressures during the day and night, when compared to whites. Together with knowledge on the contributions of sympathetic activation and abnormal renal sodium handling, these pathophysiological adaptations result in subclinical and clinical organ damage at younger ages. This overall enhanced understanding on the determinants of blood pressure elevation in blacks encourages (a) novel approaches to assess and manage hypertension in Africa better, (b) further scientific discovery to develop more effective prevention and treatment strategies, and (c) policymakers and health advocates to collectively contribute in creating health-promoting environments in Africa

Modelling mammalian energetics: the heterothermy problem

Global climate change is expected to have strong effects on the world’s flora and fauna. As a result, there has been a recent increase in the number of meta-analyses and mechanistic models that attempt to predict potential responses of mammals to changing climates. Many models that seek to explain the effects of environmental temperatures on mammalian energetics and survival assume a constant body temperature. However, despite generally being regarded as strict homeotherms, mammals demonstrate a large degree of daily variability in body temperature, as well as the ability to reduce metabolic costs either by entering torpor, or by increasing body temperatures at high ambient temperatures. Often, changes in body temperature variability are unpredictable, and happen in response to immediate changes in resource abundance or temperature. In this review we provide an overview of variability and unpredictability found in body temperatures of extant mammals, identify potential blind spots in the current literature, and discuss options for incorporating variability into predictive mechanistic models

ELISA versus PCR for diagnosis of chronic Chagas disease: systematic review and meta-analysis

<p>Abstract</p> <p>Background</p> <p>Most current guidelines recommend two serological tests to diagnose chronic Chagas disease. When serological tests are persistently inconclusive, some guidelines recommend molecular tests. The aim of this investigation was to review chronic Chagas disease diagnosis literature and to summarize results of ELISA and PCR performance.</p> <p>Methods</p> <p>A systematic review was conducted searching remote databases (MEDLINE, LILACS, EMBASE, SCOPUS and ISIWeb) and full texts bibliography for relevant abstracts. In addition, manufacturers of commercial tests were contacted. Original investigations were eligible if they estimated sensitivity and specificity, or reliability -or if their calculation was possible - of ELISA or PCR tests, for chronic Chagas disease.</p> <p>Results</p> <p>Heterogeneity was high within each test (ELISA and PCR) and threshold effect was detected only in a particular subgroup. Reference standard blinding partially explained heterogeneity in ELISA studies, and pooled sensitivity and specificity were 97.7% [96.7%-98.5%] and 96.3% [94.6%-97.6%] respectively. Commercial ELISA with recombinant antigens studied in phase three investigations partially explained heterogeneity, and pooled sensitivity and specificity were 99.3% [97.9%-99.9%] and 97.5% [88.5%-99.5%] respectively. ELISA's reliability was seldom studied but was considered acceptable. PCR heterogeneity was not explained, but a threshold effect was detected in three groups created by using guanidine and boiling the sample before DNA extraction. PCR sensitivity is likely to be between 50% and 90%, while its specificity is close to 100%. PCR reliability was never studied.</p> <p>Conclusions</p> <p>Both conventional and recombinant based ELISA give useful information, however there are commercial tests without technical reports and therefore were not included in this review. Physicians need to have access to technical reports to understand if these serological tests are similar to those included in this review and therefore correctly order and interpret test results. Currently, PCR should not be used in clinical practice for chronic Chagas disease diagnosis and there is no PCR test commercially available for this purpose. Tests limitations and directions for future research are discussed.</p

Validation d’une méthode de quantification de l’alcoolémie chez les conducteurs impliqués dans des accidents corporels de la circulation routière en Cote d’Ivoire

Objectifs: 1. Valider une méthode simple et fiable de quantification de l’alcoolémie tenant comptede la disponibilité de nos ressources matérielles et humaines 2. Evaluer l’alcoolisation chez des conducteurs impliqués dans un accident corporel de la circulation routièreMatériels et Méthodes: Nous avons adapté la méthode de préparation d’échantillon de sang total développée par Szymanowicz et nous avons déterminé l’alcoolémie par CPGFID en utilisant le N-propanol comme Etalon Interne. Cette méthode a été validée selon les critères classiques recommandés à savoir la détermination de : la justesse, l’exactitude, le taux de recouvrement, la linéarité, la LOD et la LOQ. Une fois validée, la méthode a été appliquée à un échantillon de conducteurs blessés suite à un AVP et recrutés aux urgences du CHU de Yopougon et à l’IMLA en vue de la quantification de l’alcoolémie.Résultats: La méthode que nous avons développée a démontrée qu’elle possédait toutes les qualités d’une méthode fiable et répondant aux critères de performances analytiques requises en terme de sélectivité, de fidélité (CV &lt; 5%), de justesse (biais= 0,03-0,065 g/L) et de linéarité (R2 &gt; 0,999). La LOQ (0,146 g/L) est parfaitement adaptée aux besoins de la législation en Côte d’Ivoire (alcoolémie ≤ 0,8 g/L). Les alcoolémies mesurées chez les conducteurs alcoolisés dépassent en moyenne de 2,4 fois le seuil légal en Côte d’Ivoire.Conclusion: L’application de notre méthode à l’étude des traumatismes associés à la conduite sous l’influence de l’alcool à Abidjan démontre l’importance de l’Expertise Toxicologique dans les stratégies de prévention du traumatisme routier et dans le renforcement de la loi en Côte d’Ivoire.Mots clés: Alcoolémie ; CPG-FID ; Validation ; Performances Analytiques ; Conduite sous influence ; Traumatisme routier.English Title: Validation of a GC-FID method for the quantification of blood alcohol concentration in drivers involved in a road traffic accident in Cote d’IvoireEnglish AbstractObjectives: 1. To validate a simple and reliable method for the quantification of blood alcohol concentration which take into account the availability of our material and human resources;2. To assess alcohol consumption in drivers injured following a road traffic accident.Material and Methods: We modified the blood sample extraction and preparation method described by Szymanowicz, and blood alcohol concentration was quantified using GCFID with N-propanol as Internal Standard. This method was validated following the required international criteria: precision, accuracy, recovery, linearity, LOD and LOQ. Then, we applied the method to assess blood alcohol concentration in a sample of drivers injured after a road traffic accident and admitted to the Emergency Room or the Forensic Institute.Results: We have developed a reliable method who demonstrated a good compliance with analytical performance requirements in terms of repeatability (CV &lt; 5%), accuracy (bias= 0.03-0.065 g/L) and linearity (R2 &gt; 0.999). LOQ (0.146 g/L) was perfectly adapted to the needs of the Drink-Driving Law in Cote d’Ivoire (Statutory threshold ≤ 0.8 g/L). Blood Alcohol Concentrations in drivers who have drunk was on average 2.4 times the statutory threshold in Cote d’Ivoire.Conclusion: The application of our analytical method to the study of trauma associated to driving under the influence of alcohol in Abidjan, demonstrated the relevance of Toxicology Expertise in road injury prevention strategies and the strengthening of drinkdriving law in Cote d’Ivoire.Keywords: Blood Alcohol Concentration; GC-FID; Method Validation; Analytical Performances; Driving Under Influence of Alcohol; Road Traffic Injur

Differential Evolution with Landscape-Based Operator Selection for Solving Numerical Optimization Problems

In this paper, a new differential evolution framework is proposed. In it, the best-performing differential evolution mutation strategy, from a given set, is dynamically determined based on a problem’s landscape, as well as the performance history of each operator. The performance of the proposed algorithm has been tested on a set of 30 unconstrained single objective real-parameter optimization problems. The experimental results show that the proposed algorithm is capable of producing good solutions that are clearly better than those obtained from a set of considered state-of-the-art algorithms

Is West Nile virus a potential cause of central nervous system infection in Brazil? Seria o vírus do Oeste do Nilo causa potencial de infecção no sistema nervoso central no Brasil?

Meningitis and encephalitis are complications of West Nile virus (WNV) infection. Although WNV is endemic in North America, the virus has recently been reported in Colombia and Argentina. Investigation of WNV in Brazil is important since this virus has never been studied previously in this country. OBJECTIVE: To investigate the presence of WNV infection in viral encephalitis/meningitis cases of unknown etiology in the city of Rio de Janeiro, Brazil. METHOD: Thirty-seven adults with viral meningitis/encephalitis had their serum and CSF tested for WNV antibodies using the ELISA method. RESULTS: Only one case was WNV-positive, but this case was also positive for dengue. The plaque reduction neutralization test distinguished infections, and was negative for WNV. CONCLUSION: WNV can be confused with dengue infection. Their symptoms and neurological picture are similar. We did not find WNV in any patients with encephalitis and meningitis in the city of Rio de Janeiro. Up to now, it has not been detected in Brazil<br>Meningite e encefalite são complicações da infecção pelo vírus do Oeste do Nilo (VON). Embora o VON seja endêmico na América do Norte, recentemente o vírus foi descrito na Colômbia e Argentina. Sua pesquisa no Brasil é importante uma vez que o vírus nunca fora estudado antes em nosso país. OBJETIVO: Investigar a presença do VON em casos de meningite e encefalite viral de etiologia desconhecida, na cidade no Rio de Janeiro, Brasil. MéTODO: Trinta e sete adultos com quadro de meningite/encefalite tiveram seu LCR e soro testados para anticorpos anti-VON, pelo método ELISA. RESULTADOS: Apenas um caso obteve sorologia positiva para VON, mas a sorologia para dengue também fora positiva. O teste da neutralização por redução de placa foi utilizado para distinção entre as infecções, sendo negativo para VON. CONCLUSÃO: A infecção por VON pode ser confundida com a infecção pelo vírus da dengue, seus sintomas e quadro neurológico são similares. Nós não encontramos o VON em pacientes com meningite/ encefalite na cidade do Rio de Janeiro. Até o momento ele ainda não foi identificado no Brasi