Influence de la température et de la nourriture disponible sur la torpeur chez la Musaraigne musette (Crocidura russula) en captivité

The effects of temperature and food shortage on the occurrence of torpor have been studied in a medium-weight shrew, Crocidura russula (9-13 g). When fed ad libitum. the shrews cannot be forced into torpor by a sudden decrease of the ambiant temperature (from22°C to 3°C). At 22°C, a progressive restriction of the daily food ration, to below 3 g of mealworms, induces torpors of increasing duration, a reduction of the daily activity and a reduction of the body weight. The minimal daily food ration required for survivals is 1 to 1,5 G. At low ambiant temperature (e.g. 5°C), torpor can be induced at higher food levels (4-5g).

Smoking offsets the metabolic benefits of parental longevity in women: the CoLaus study.

OBJECTIVE: We evaluated whether subjects with long-lived parents show lower levels of cardiovascular risk factors, including the metabolic syndrome. METHODS: We analyzed data from a Swiss population-based sample (1163 men and 1398 women) aged 55-75 years from Lausanne. Participants were stratified by number of parents (0, 1, 2) who survived to 85 years or more. The associations of parental longevity with cardiovascular risk factors and related metabolic variables were analyzed using multiple linear regressions. RESULTS: Age-adjusted metabolic syndrome prevalence varied from 24.8%, 20.5% to 13.8% in women (P<0.05) and from 28.8%, 32.1% to 27.6% in men (not significant) with 0, 1 and 2 long-lived parents. The association between parental longevity and metabolic syndrome prevalence was particularly strong in women who had never smoked. In this group, women with 2 long-lived parents had lower Body Mass Index and smaller waist circumference. In never-smokers of both genders, mean (95% CI) adjusted High Density Lipoprotein-cholesterol levels were 1.64(1.61-1.67), 1.67(1.65-1.70) and 1.71(1.65-1.76) mmol/L for 0, 1 and 2 long-lived parents (P<0.01), respectively. The trend was not significant in former and current smokers. CONCLUSIONS: In women, not in men, parental longevity is associated with a better metabolic profile. The metabolic benefits of having long-lived parents are offset by smoking.

Hepatitis E Virus Seroprevalence among Blood Donors in Southwest Switzerland.

Aim: The aim of this study was to determine the seroprevalence of Hepatitis E virus (HEV) among blood donors in southwest Switzerland.Background: HEV is recognized as a food-borne disease in industrialized countries, transmitted mainly through pork meat. Cases of transmission through blood transfusion have also been reported. Recent studies have revealed seroprevalence rates of 13.5%, 16.6% and 20.6% among blood donors in England, France and Denmark, respectively.Methods: We analyzed 550 consecutive blood donor samples collected in the region of Lausanne, canton of Vaud, Switzerland, for the presence of anti-HEV IgG, using the MP Diagnostics HEV ELISA kit. For each donor, we documented age, sex and alanine aminotransferase (ALT) value.Results: The study panel was composed of 332 men (60.4%) and 218 women (39.6%). Overall, anti-HEV IgG was found in 27 of 550 samples (4.9%). The seroprevalence was 5.4% (18/332) in men and 4.1% (9/218) in women. The presence of anti-HEV IgG was not correlated with age, gender or ALT values. However, we observed a peak in seroprevalence of 5.3% in individuals aged 51 to 70 years old.Conclusions: Compared with other European countries, HEV seroprevalence among blood donors in southwest Switzerland is low. The low seroprevalence may be explained by the sensitivity of commercial tests used and/or the strict regulation of animal and meat imports. Data regarding HEV prevalence in Swiss livestock are lacking and merit exploration.

Comparative transcriptomics of rice reveals an ancient pattern of response to microbial colonization.

Glomalean fungi induce and colonize symbiotic tissue called arbuscular mycorrhiza on the roots of most land plants. Other fungi also colonize plants but cause disease not symbiosis. Whole-transcriptome analysis using a custom-designed Affymetrix Gene-Chip and confirmation with real-time RT-PCR revealed 224 genes affected during arbuscular mycorrhizal symbiosis. We compared these transcription profiles with those from rice roots that were colonized by pathogens (Magnaporthe grisea and Fusarium moniliforme). Over 40% of genes showed differential regulation caused by both the symbiotic and at least one of the pathogenic interactions. A set of genes was similarly expressed in all three associations, revealing a conserved response to fungal colonization. The responses that were shared between pathogen and symbiont infection may play a role in compatibility. Likewise, the responses that are different may cause disease. Some of the genes that respond to mycorrhizal colonization may be involved in the uptake of phosphate. Indeed, phosphate addition mimicked the effect of mycorrhiza on 8% of the tested genes. We found that 34% of the mycorrhiza-associated rice genes were also associated with mycorrhiza in dicots, revealing a conserved pattern of response between the two angiosperm classes.

Biological embedding of early life exposures and disease risk in humans: a role for DNA methylation.

BACKGROUND: Following wider acceptance of "the thrifty phenotype" hypothesis and the convincing evidence that early life exposures can influence adult health even decades after the exposure, much interest has been placed on the mechanisms through which early life exposures become biologically embedded. METHODS: In this review, we summarize the current literature regarding biological embedding of early life experiences. To this end we conducted a literature search to identify studies investigating early life exposures in relation to DNA methylation changes. In addition, we summarize the challenges faced in investigations of epigenetic effects, stemming from the peculiarities of this emergent and complex field. A proper systematic review and meta-analyses were not feasible given the nature of the evidence. RESULTS: We identified 7 studies on early life socioeconomic circumstances, 10 studies on childhood obesity, and 6 studies on early life nutrition all relating to DNA methylation changes that met the stipulated inclusion criteria. The pool of evidence gathered, albeit small, favours a role of epigenetics and DNA methylation in biological embedding, but replication of findings, multiple comparison corrections, publication bias, and causality are concerns remaining to be addressed in future investigations. CONCLUSIONS: Based on these results, we hypothesize that epigenetics, in particular DNA methylation, is a plausible mechanism through which early life exposures are biologically embedded. This review describes the current status of the field and acts as a stepping stone for future, better designed investigations on how early life exposures might become biologically embedded through epigenetic effects. This article is protected by copyright. All rights reserved.

Capsaicin mimics mechanical load-induced intracellular signaling events: involvement of TRPV1-mediated calcium signaling in induction of skeletal muscle hypertrophy.

Mechanical load-induced intracellular signaling events are important for subsequent skeletal muscle hypertrophy. We previously showed that load-induced activation of the cation channel TRPV1 caused an increase in intracellular calcium concentrations ([Ca ( 2+) ]i) and that this activated mammalian target of rapamycin (mTOR) and promoted muscle hypertrophy. However, the link between mechanical load-induced intracellular signaling events, and the TRPV1-mediated increases in [Ca ( 2+) ]i are not fully understood. Here we show that administration of the TRPV1 agonist, capsaicin, induces phosphorylation of mTOR, p70S6K, S6, Erk1/2 and p38 MAPK, but not Akt, AMPK or GSK3β. Furthermore, the TRPV1-induced phosphorylation patterns resembled those induced by mechanical load. Our results continue to highlight the importance of TRPV1-mediated calcium signaling in load-induced intracellular signaling pathways.

Dispersions dans la réalisation autonome des activités de la vie quotidienne (AVQ) dans la démence.

Un premier article présentait la réalisation autonome des activités de la vie quotidienne (AVQ) dans la démence. Cette réalisation est constituée de deux phases : l'articulation du sujet avec l'objectif et le déroulement proprement dit. Dans ce second article, nous présentons une typologie des actions-dispersions, précisant la deuxième phase. Considérant le sujet autonome en lien intentionnel avec l'activité, nous définissons les dispersions comme un désengagement de l'activité. L'analyse des dispersions vise à comprendre plus exactement et de façon différenciée la réalisation des AVQ en cas de démence. Notre approche anthropologique, qui intègre les dimensions psychologiques et comportementales, se démarque des approches comportementaliste et neuropsychologique, en ce sens qu'elle permet d'intégrer les conduites dans leur ordre de réalité et au sein de la structure d'ensemble de l'activité. A partir d'observations visant l'intentionnalité du sujet, nous avons dégagé des types de dispersion, leurs origines - dans le sens de moment d'apparition - et leurs formes. Nous illustrons cette typologie par des exemples extraits d'une prise en soin. Les deux articles se complètent pour présenter un modèle fonctionnel définissant la réalisation des AVQ en cas de démence. Il s'agit d'un schème théorique permettant d'interpréter et d'anticiper le fonctionnement du sujet dément afin de le guider, tout en lui laissant une marge de maîtrise de son milieu quotidien.

La réalisation autonome des activités de la vie quotidienne dans la démence.

A côté de la pratique psychothérapique, de la recherche en laboratoire et des travaux classificatoires, nous proposons une approche anthropologique de la démence. Cette approche combine et coordonne recherche, réhabilitation et transfert des résultats dans les soins. Les activités de la Lebenswelt nous servent de situation d'observation participante. Elles satisfont les conditions nécessaires pour comprendre le patient souffrant de démence comme sujet, agent de ses actions et animé d'une motivation qui lui est propre. C'est à partir du fonctionnement subjectif, constituant une unité Individu-Environnement, que nous pouvons à la fois évaluer l'autonomie, la respecter et la promouvoir. L'étude du cas présenté sert à illustrer cette approche fonctionnelle et à définir trois catégories ancrées dans la réalisation des activités de la vie quotidienne (AVQ) : articulation, lien intentionnel et transition critique. A partir d'extraits d'observations d'une patiente réalisant deux types d'AVQ (prise du repas et toilette-habillage), nous faisons une analyse qualitative des moments-clés correspondant à nos catégories, du point de vue des capacités de la patiente et du point de vue des aides offertes. L'ordre descriptif et catégoriel de notre travail permet de dégager une structure générale en deux phases de la réalisation autonome des AVQ dans la démence.

Risk determinants of acute mountain sickness in trekkers in the Nepali Himalaya: a 24-year follow-up.

OBJECTIVE: Exposure to altitude may lead to acute mountain sickness (AMS) in nonacclimatized individuals. We surveyed AMS prevalence and potential risk factors in trekkers crossing a 5400-m pass in Nepal and compared the results with those of 2 similar studies conducted 12 and 24 years earlier. METHODS: In April 2010, 500 surveys were distributed to English-speaking trekkers at 3500 m on their way to 5400 m, of which 332 (66%) surveys were returned complete. Acute mountain sickness was quantified with the Lake Louise Scoring System (LLSS, cutoff ≥3 and ≥5) and the Environmental Statistical Questionnaire III AMS-C score (ESQ-III, cutoff ≥0.7). We surveyed demographics, body mass index (BMI), smoking habit, rate of ascent, awareness of AMS, and acetazolamide use. RESULTS: Prevalence of AMS was 22%, 23%, and 48% (ESQ-III ≥0.7, LLSS ≥5, and LLSS ≥3, respectively) lower when compared with earlier studies. Risk factors for AMS were younger age, female sex, higher BMI, and smoking habit. Forty-two percent had elementary knowledge about the risk and prevention of AMS. Forty-four percent used acetazolamide. Trekkers took longer to climb from 3500 to 5400 m than in earlier studies. CONCLUSIONS: Prevalence of AMS continued to decline over a period of 24 years, likely as a result of slower ascent and increased use of acetazolamide. The AMS risk factors of younger age, female sex, and high BMI are consistent with prior studies. Awareness of risk and prevention of AMS remains low, indicating an opportunity to better educate trekkers and potentially further reduce AMS prevalence.

Nanoparticle usage and protection measures in the manufacturing industry : a representative survey

Addressing the risks of nanoparticles requires knowledge about release into the environment and occupational exposure. However, such information currently is not systematically collected; therefore, this risk assessment lacks quantitative data. The goal was to evaluate the current level of nanoparticle usage in Swiss industry as well as health, safety, and environmental measures, and the number of potentially exposed workers. A representative, stratified mail survey was conducted among 1626 clients of the Swiss National Accident Insurance Fund (SUVA), which insures 80,000 manufacturing firms, representing 84% of all Swiss manufacturing companies (947 companies answered the survey for a 58.3% response rate). The extrapolation to all Swiss manufacturing companies results in 1309 workers (95% confidence interval [CI]: 1073 to 1545) potentially exposed to nanoparticles in 586 companies (95% CI: 145 to 1027). This corresponds to 0.08% of workers (95% CI: 0.06% to 0.09%) and to 0.6% of companies (95% CI: 0.2% to 1.1%). The industrial chemistry sector showed the highest percentage of companies using nanoparticles (21.2%). Other important sectors also reported nanoparticles. Personal protection equipment was the predominant protection strategy. Only a few applied specific environmental protection measures. This is the first nationwide representative study on nanoparticle use in the manufacturing sector. The information gained can be used for quantitative risk assessment. It can also help policymakers design strategies to support companies developing a safer use of nanomaterial. Notingthe current low use of nanoparticles, there is still time to proactively introduce protective methods. If the predicted "nano-revolution" comes true, now is the time to take action. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of occupational and Environmental Hygiene for the following free supplemental resource: a pdf file containing a detailed description of the approach to statistical analyses, English translation of the questionnaire, additional information for Figure 1, and additional information for the SUVA-code.] [Authors]

A MODEL OF CREATINE DEFICIENCY SYNDROMES IN 3D BRAIN CELL CULTURES BY KNOCKDOWN OF GAMT AND SLC6A8 GENES

La créatine joue un rôle essentiel dans le métabolisme cellulaire par sa conversion, par la creatine kinase, en phosphocreatine permettant la régénération de l'ATP. La synthèse de créatine, chez les mammifères, s'effectue par une réaction en deux étapes impliquant Γ arginine: glycine amidinotransférase (AGAT) et la guanidinoacétate méthyltransférase (GAMT). L'entrée de créatine dans les cellules s'effectue par son transporteur, SLC6A8. Les déficiences en créatine, dues au déficit en GAMT, AGAT ou SLC6A8, sont fréquentes et caractérisées par une absence ou une forte baisse de créatine dans le système nerveux central. Alors qu'il est connu que AGAT, GAMT et SLC6A8 sont exprimés par le cerveau, les conséquences des déficiences en créatine sur les cellules nerveuses sont peu comprises. Le but de ce travail était de développer de nouveaux modèles expérimentaux des déficiences en Cr dans des cultures 3D de cellules nerveuses de rat en agrégats au moyen de l'interférence à l'ARN appliquée aux gènes GAMT et SLC6A8. Des séquences interférentes (shRNAs) pour les gènes GAMT et SLC6A8 ont été transduites par des vecteurs viraux AAV (virus adéno-associés), dans les cellules nerveuses en agrégats. Nous avons ainsi démontré une baisse de l'expression de GAMT au niveau protéique (mesuré par western blot), et ARN messager (mesuré par qPCR) ainsi qu'une variation caractérisitique de créatine et guanidinoacétate (mesuré par spectrométrie de masse). Après avoir validé nos modèles, nous avons montré que les knockdown de GAMT ou SLC6A8 affectent le développement des astrocytes et des neurones ou des oligodendrocytes et des astrocytes, respectivement, ainsi qu'une augmentation de la mort cellulaire et des modifications dans le pattern d'activation des voies de signalisation impliquant caspase 3 et p38 MAPK, ayant un rôle dans le processus d'apoptose. - Creatine plays essential roles in energy metabolism by the interconversion, by creatine kinase, to its phosphorylated analogue, phosphocreatine, allowing the regeneration of ATP. Creatine is synthesized in mammals by a two step mechanism involving arginine:glycine amidinotransferase (AGAT) and guanidinoacetate methyltransferase (GAMT). Creatine is taken up by cells by a specific transporter, SLC6A8. Creatine deficiency syndromes, due to defects in GAMT, AGAT and SLC6A8, are among the most frequent inborn errors of metabolism, and are characterized by an absence or a severe decrease of creatine in central nervous system, which is the main tissue affected. While it is known that AGAT, GAMT and SLC6A8 are expressed in CNS, many questions remain on the specific effects of AGAT, GAMT and SLC6A8 deficiencies on brain cells. Our aim was to develop new experimental models of creatine deficiencies by knockdown of GAMT and SLC6A8 genes by RNAi in 3D organotypic rat brain cell cultures in aggregates. Specific shRNAs for the GAMT and SLC6A8 genes were transduced in brain cell aggregates by adeno-associated viruses (AAV). The AAV-transduced shRNAs were able to efficiently knockdown the expression of our genes of interest, as shown by a strong decrease of protein by western blotting, a decrease of mRNA by qPCR or characteristic variations of creatine and guanidinoacetate by tandem mass spectrometry. After having validated our experimental models, we have also shown that GAMT and SLC6A8 knockdown affected the development of astrocytes and neurons or oligodendrocytes and astrocytes, respectively. We also observed an increase of cell death and variations in activation pattern of caspase 3 and p38 MAPK pathways, involved in apoptosis, in our experimental model.

Improving prediction of recanalization in acute large-vessel occlusive stroke.

BACKGROUND: Recanalization in acute ischemic stroke with large-vessel occlusion is a potent indicator of good clinical outcome. OBJECTIVE: To identify easily available clinical and radiologic variables predicting recanalization at various occlusion sites. METHODS: All consecutive, acute stroke patients from the Acute STroke Registry and Analysis of Lausanne (2003-2011) who had a large-vessel occlusion on computed tomographic angiography (CTA) (< 12 h) were included. Recanalization status was assessed at 24 h (range: 12-48 h) with CTA, magnetic resonance angiography, or ultrasonography. Complete and partial recanalization (corresponding to the modified Treatment in Cerebral Ischemia scale 2-3) were grouped together. Patients were categorized according to occlusion site and treatment modality. RESULTS: Among 439 patients, 51% (224) showed complete or partial recanalization. In multivariate analysis, recanalization of any occlusion site was most strongly associated with endovascular treatment, including bridging therapy (odds ratio [OR] 7.1, 95% confidence interval [CI] 2.2-23.2), and less so with intravenous thrombolysis (OR 1.6, 95% CI 1.0-2.6) and recanalization treatments performed beyond guidelines (OR 2.6, 95% CI 1.2-5.7). Clot location (large vs. intermediate) and tandem pathology (the combination of intracranial occlusion and symptomatic extracranial stenosis) were other variables discriminating between recanalizers and non-recanalizers. For patients with intracranial occlusions, the variables significantly associated with recanalization after 24 h were: baseline National Institutes of Health Stroke Scale (NIHSS) (OR 1.04, 95% CI 1.02-1.1), Alberta Stroke Program Early CT Score (ASPECTS) on initial computed tomography (OR 1.2, 95% CI 1.1-1.3), and an altered level of consciousness (OR 0.2, 95% CI 0.1-0.5). CONCLUSIONS: Acute endovascular treatment is the single most important factor promoting recanalization in acute ischemic stroke. The presence of extracranial vessel stenosis or occlusion decreases recanalization rates. In patients with intracranial occlusions, higher NIHSS score and ASPECTS and normal vigilance facilitate recanalization. Clinical use of these predictors could influence recanalization strategies in individual patients.