Faut-il traiter les dyslipidémies chez les personnes âgées et très âgées. [Should we treat dyslipidemia in the elderly and the oldest old?].

Therapy of dyslipidemia in the elderly and the oldest old remains controversial. Several studies have shown benefits of statins on secondary prevention of cardiovascular disease in older adults up to 80 years, but data remain scarce after that age. Fewer studies have assessed the impact of statins in primary prevention in the elderly. Most studies have not included adults older than 75 years, and absolute risk reduction is far lower compared to secondary prevention. Use of statins for primary prevention in this age group should be based on individual decision, taking into account patient's functional and cognitive status, comorbidities and other therapies to avoid drugs interactions, with the help of shared-decision making.

Respiratory quotient evolution during normal pregnancy: what nutritional or clinical information can we get out of it?

Food intake increases to a varying extent during pregnancy to provide extra energy for the growing fetus. Measuring the respiratory quotient (RQ) during the course of pregnancy (by quantifying O2 consumption and CO2 production with indirect calorimetry) could be potentially useful since it gives an insight into the evolution of the proportion of carbohydrate vs. fat oxidized during pregnancy and thus allows recommendations on macronutrients for achieving a balanced (or slightly positive) substrate intake. A systematic search of the literature for papers reporting RQ changes during normal pregnancy identified 10 papers reporting original research. The existing evidence supports an increased RQ of varying magnitude in the third trimester of pregnancy, while the discrepant results reported for the first and second trimesters (i.e. no increase in RQ), explained by limited statistical power (small sample size) or fragmentary data, preclude safe conclusions about the evolution of RQ during early pregnancy. From a clinical point of view, measuring RQ during pregnancy requires not only sophisticated and costly indirect calorimeters but appears of limited value outside pure research projects, because of several confounding variables: (1) spontaneous changes in food intake and food composition during the course of pregnancy (which influence RQ); (2) inter-individual differences in weight gain and composition of tissue growth; (3) technical factors, notwithstanding the relatively small contribution of fetal metabolism per se (RQ close to 1.0) to overall metabolism of the pregnant mother.

La Implicació de Hollywood en la Segunda Guerra Mundial: el cas Why we fight

Why we fight és un grup de set pel·lícules de format documental que van formar part d’un ampli programa d’informació, formació i propaganda impulsat per l’exèrcit nord-americà, en el moment en què els Estats Units ja s’havien implicat en la Segona Guerra Mundial. És també un dels més reeixits exercicis de retòrica cinematogràfica nord-americana d’aquell període que permet analitzar com els països democràtics van gestionar qüestions tan compromeses com la propaganda de guerra. La pretensió d’aquest treball de recerca és aprofundir en la complexitat ideològica i formal de la sèrie, que faci possible descobrir-ne els orígens, els objectius i la manera com aquests van ser assolits per un grup d’especialistes cinematogràfics, coordinats pel director Frank Capra, tots els quals havien triomfat fins llavors a Hollywood

Small vascular and Alzheimer disease-related pathologic determinants of dementia in the oldest-old.

The relative contributions of Alzheimer disease (AD) and vascular lesion burden to the occurrence of cognitive decline are more difficult to define in the oldest-old than they are in younger cohorts. To address this issue, we examined 93 prospectively documented autopsy cases from 90 to 103 years with various degrees of AD lesions, lacunes, and microvascular pathology. Cognitive assessment was performed prospectively using the Clinical Dementia Rating scale. Neuropathologic evaluation included the Braak neurofibrillary tangle (NFT) and β-amyloid (Aβ) protein deposition staging and bilateral semiquantitative assessment of vascular lesions. Statistics included regression models and receiver operating characteristic analyses. Braak NFTs, Aβ deposition, and cortical microinfarcts (CMIs) predicted 30% of Clinical Dementia Rating variability and 49% of the presence of dementia. Braak NFT and CMI thresholds yielded 0.82 sensitivity, 0.91 specificity, and 0.84 correct classification rates for dementia. Using these threshold values, we could distinguish 3 groups of demented cases and propose criteria for neuropathologic definition of mixed dementia, pure vascular dementia, and AD in very old age. Braak NFT staging and severity of CMI allow for defining most of demented cases in the oldest-old. Most importantly, single cutoff scores for these variables that could be used in the future to formulate neuropathologic criteria for mixed dementia in this age group were identified.

Compartmentalization in membrane rafts defines a pool of N-cadherin associated with catenins and not engaged in cell-cell junctions in melanoma cells.

Melanoma progression is associated with changes in adhesion receptor expression, in particular upregulation of N-cadherin which promotes melanoma cell survival and invasion. Plasma membrane lipid rafts contribute to the compartmentalization of signaling complexes thereby regulating their function, but how they may affect the properties of adhesion molecules remains elusive. In this study, we addressed the question whether lipid rafts in melanoma cells may contribute to the compartmentalization of N-cadherin. We show that a fraction of N-cadherin in a complex with catenins is associated with cholesterol/sphingolipid-rich membrane microdomains in aggressive melanoma cells in vitro and experimental melanomas in vivo. Partitioning of N-cadherin in membrane rafts is not modulated by growth factors and signaling pathways relevant to melanoma progression, is not necessary for cell-cell junctions' establishment or maintenance, and is not affected by cell-cell junctions' and actin cytoskeleton disruption. These results reveal that two independent pools of N-cadherin exist on melanoma cell surface: one pool is independent of lipid rafts and is engaged in cell-cell junctions, while a second pool is localized in membrane rafts and does not participate in cell-cell adhesions. Targeting to membrane rafts may represent a previously unrecognized mechanism regulating N-cadherin function in melanoma cells.

Answer : African net survey - we respond !

Between the end of August and December 2013, an internet based survey named ANSWER will collect data about sexual health, sexual behavior and risk taking among Sub-Saharan African migrants (SSAm) living in Switzerland. This research is carried out by the Institut de médecine sociale et préventive (IUMSP, Lausanne) on a mandate from the Federal Offi ce of Public Health (FOPH), in cooperation with the Swiss Aids Federation (AHS) and other institutions addressing the prevention and information needs of the African population living in Switzerland.

Can we continue to neglect genomic variation in introgression rates when inferring the history of speciation? A case study in a Mytilus hybrid zone.

The use of molecular data to reconstruct the history of divergence and gene flow between populations of closely related taxa represents a challenging problem. It has been proposed that the long-standing debate about the geography of speciation can be resolved by comparing the likelihoods of a model of isolation with migration and a model of secondary contact. However, data are commonly only fit to a model of isolation with migration and rarely tested against the secondary contact alternative. Furthermore, most demographic inference methods have neglected variation in introgression rates and assume that the gene flow parameter (Nm) is similar among loci. Here, we show that neglecting this source of variation can give misleading results. We analysed DNA sequences sampled from populations of the marine mussels, Mytilus edulis and M. galloprovincialis, across a well-studied mosaic hybrid zone in Europe and evaluated various scenarios of speciation, with or without variation in introgression rates, using an Approximate Bayesian Computation (ABC) approach. Models with heterogeneous gene flow across loci always outperformed models assuming equal migration rates irrespective of the history of gene flow being considered. By incorporating this heterogeneity, the best-supported scenario was a long period of allopatric isolation during the first three-quarters of the time since divergence followed by secondary contact and introgression during the last quarter. By contrast, constraining migration to be homogeneous failed to discriminate among any of the different models of gene flow tested. Our simulations thus provide statistical support for the secondary contact scenario in the European Mytilus hybrid zone that the standard coalescent approach failed to confirm. Our results demonstrate that genomic variation in introgression rates can have profound impacts on the biological conclusions drawn from inference methods and needs to be incorporated in future studies.

Volutrauma activates the clotting cascade in the newborn but not adult rat.

Coagulopathy and alveolar fibrin deposition are common in sick neonates and attributed to the primary disease, as opposed to their ventilatory support. Hypothesizing that high tidal volume ventilation activates the extrinsic coagulation pathway, we air ventilated newborn and adult rats at low (10 ml/kg) or high (30 ml/kg) tidal volume and compared them with age-matched nonventilated controls. Blood was collected at the end of the experiment for measurement of clot time, tissue factor, and other coagulation factor content. Similar measurements were obtained from lung lavage material. The newborn clot time (44+/-1) was lower and plasma tissue factor content higher (103.4+/-0.4) than adults (88+/-4 s and 26.6+/-1.4 units; P<0.01). High, but not low, tidal volume ventilation of newborns for as little as 15 min significantly reduced clot time and increased plasma tissue factor content (P<0.01). High volume ventilation increased plasma factor Xa (0.1+/-0.1 to 1.6+/-0.4 nM; P<0.01) and thrombin (1.3+/-0.2 to 2.2+/-0.4 nM; P<0.05) and decreased antithrombin (0.12+/-0.01 to 0.05+/-0.01; P<0.01) in the newborn. Lung lavage material of high volume-ventilated newborns showed increased (P<0.01) factor Xa and thrombin. No changes in these parameters were observed in adult rats that were high volume ventilated for up to 90 min. Compared with adults, newborn rats have a greater propensity for volutrauma-activated intravascular coagulation. These data suggest that mechanical ventilation promotes neonatal thrombosis via lung tissue factor release.

Dialyse et écologie: est-il possible de faire mieux à l'avenir [Dialysis and ecology: can we do better in the future?].

Development of dialysis has saved the lives of many patients. However, haemodialysis and peritoneal dialysis are very demanding in resources such as water and electricity, and generate a large amount of waste. In this article, we will review the environmental aspects of dialysis. Different solutions will be discussed, such as recycling of water discharged during reverse osmosis, the integration of solar energy, recycling of waste plastics, and the use of other techniques such as sorbent dialysis. In a world where natural resources are precious and where global warming is a major problem, it is important that not only dialysis, but all branches of medicine become more attentive to ecology.

Crosstalk between peroxisome proliferator-activated receptor delta and VEGF stimulates cancer progression.

Peroxisome proliferator-activated receptor (PPAR) delta is a member of the nuclear hormone receptor superfamily. PPARdelta may ameliorate metabolic diseases such as obesity and diabetes. However, PPARdelta's role in colorectal carcinogenesis remains controversial. Here, we present genetic and pharmacologic evidence demonstrating that deletion of PPARdelta decreases intestinal adenoma growth in Apc(Min/+) mice and inhibits tumor-promoting effects of a PPARdelta agonist GW501516. More importantly, we found that activation of PPARdelta up-regulated VEGF in colon carcinoma cells. VEGF directly promotes colon tumor epithelial cell survival through activation of PI3K-Akt signaling. These results not only highlight concerns about the use of PPARdelta agonists for treatment of metabolic disorders in patients who are at high risk for colorectal cancer, but also support the rationale for developing PPARdelta antagonists for prevention and/or treatment of cancer.