Dexamethasone-induced upregulation of CaV3.2 T-type Ca2+ channels in rat cardiac myocytes.

Glucocorticoids are widely used to treat acute and chronic diseases. Unfortunately, their therapeutic use is associated with severe side effects. Glucocorticoids are known to regulate several ion channels in cardiac myocytes, including voltage-dependent Ca2+ channels. Low-voltage-activated T-type Ca2+ channels are expressed in ventricular myocytes during the fetal and perinatal period, but are practically absent in the adult. However, these channels can be re-expressed in adult cardiomyocytes under some pathological conditions. We have investigated the glucocorticoid regulation of T-type Ca2+ channels in rat cardiomyocytes. Molecular studies revealed that dexamethasone induces the upregulation of CaV3.2 mRNA in neonatal rat ventricular myocytes, whereas CaV3.1 mRNA is only slightly affected. Patch-clamp recordings confirmed that T-type Ca2+ channel currents were upregulated in dexamethasone treated cardiomyocytes, and the addition of 50 µmol/L NiCl2 demonstrated that the CaV3.2 channel is responsible for this upregulation. The effect of dexamethasone on CaV3.2 is mediated by the activation and translocation to the cell nucleus of the glucocorticoid receptor (GR). We have isolated the upstream promoter of the Cacna1h gene and tested its activity in transfected ventricular myocytes. The initial in silico analysis of Cacna1h promoter revealed putative glucocorticoid response elements (GREs). Transcriptional activity assays combined with deletion analyses and chromatin immunoprecipitation assays demonstrated that GR binds to a region a GRE located in -1006/-985 bp of Cacna1h promoter. Importantly, upregulation of the CaV3.2 channel is also observed in vitro in adult rat ventricular myocytes, and in vivo in a rat model of excess of glucocorticoids.

T lymphocytes dominate local leukocyte infiltration in response to intradermal injection of functionalized graphene-based nanomaterial.

Graphene-based nanomaterials (GBN) have many potential biomedical applications. However, information regarding their biological properties and interactions with cells and/or soluble factors within a complex tissue is limited. The objective of this study was to use the growing feather (GF) of chickens as a minimally invasive cutaneous test-site to assess and monitor leukocyte recruitment in response to intradermal GBN injection. Specifically, the dermis of 20 GFs per chicken was injected with 10 µl of phosphate-buffered saline (PBS)-vehicle or 10 µl of 300 µg ml-1 oxygen-functionalized (f) GBN (6 chickens/treatment). GFs were collected before- (0) and at 0.25, 1, 2, 3, 4, 5, and 7 days post-injection and used for leukocyte-population analysis of immunofluorescently stained pulp cell suspensions or histological examination. Based on flow-cytometric cell population analysis, lymphocytes and macrophages were the major leukocyte-populations infiltrating GFs in response to f-GBN presence. Compared with PBS-controls, levels of T cells (γδ-, αß-, CD4- and CD8-T cells) were greatly elevated in f-GBN-injected GFs within 6 h and remained elevated throughout the 7-day examination period. f-GBN's effects on local tissue leukocyte recruitment were not reflected in the blood, except for a higher percentage of lymphocytes on 7 days. These observations together with a visual examination of f-GBN-injected GF tissue-sections suggest a delayed-type hypersensitivity-like, inflammatory cell-mediated response to the non-biodegradable f-GBN. The GF 'in vivo test-tube'system together with blood sampling provided unique insight into the time-course, qualitative, and quantitative aspects of immune system activities initiated by the presence of f-GBN in a complex tissue of a living animal. Copyright © 2017 John Wiley & Sons, Ltd.

Surface wetting strategy prevents acute heat exposure-induced alterations of hypothalamic stress- and metabolic-related genes in broiler chickens.

Heat stress (HS) is devastating to poultry production worldwide, yet its biology and molecular responses are not well defined. Although advances in management strategy have partially alleviated the negative impact of HS, productivity still continues to decline when the ambient temperature rises. Therefore, identifying mechanism-based approaches to decrease HS susceptibility while improving production traits is critical. Recently, we made a breakthrough by applying a surface wetting strategy and showing that it improves growth performance compared with the current conventional cooling system. In the present study, we aimed to further define molecular mechanisms associated with surface wetting in ameliorating HS productivity loss in broilers. Five-week-old broiler chickens were exposed to acute HS (35°C for 2 h) alone or in combination with surface wetting. A control group was maintained at thermoneutral conditions (25°C). Core body temperature (BT) and feed intake were recorded. Blood was collected and hypothalamic tissues (main site involved in the regulation of energy homeostasis) were harvested to determine the expression profile of stress- and metabolic-related genes. Surface wetting prevents HS from increasing BT and plasma corticosterone levels ( < 0.05) and improves feeding and drinking behaviors. At molecular levels, surface wetting blocks the activation of hypothalamic heat shock protein and adenosine monophosphate-activated protein-induced by HS and significantly modulates the expression of feeding-related hypothalamic neuropeptides (agouti-related protein, proopiomelanocortin, orexin, orexin receptor, and leptin receptor). Taken together, our data represent the first evidence that surface wetting alleviates systemic and intracellular stress induced by HS and preserves the intracellular energy status, which, in turn, may result in improved broiler well-being and growth performance.

Hypoxic induction of T-type Ca(2+) channels in rat cardiac myocytes: role of HIF-1α and RhoA/ROCK signalling.

T-type Ca(2+) channels are expressed in the ventricular myocytes of the fetal and perinatal heart, but are normally downregulated as development progresses. Interestingly, however, these channels are re-expressed in adult cardiomyocytes under pathological conditions. We investigated low voltage-activated T-type Ca(2+) channel regulation in hypoxia in rat cardiomyocytes. Molecular studies revealed that hypoxia induces the upregulation of Cav 3.2 mRNA, whereas Cav 3.1 mRNA is not significantly altered. The effect of hypoxia on Cav 3.2 mRNA was time- and dose-dependent, and required hypoxia inducible factor-1α (HIF-1α) stabilization. Patch-clamp recordings confirmed that T-type Ca(2+) channel currents were upregulated in hypoxic conditions, and the addition of 50 µm NiCl2 (a T-type channel blocker) demonstrated that the Cav 3.2 channel is responsible for this upregulation. This increase in current density was not accompanied by significant changes in the Cav 3.2 channel electrophysiological properties. The small monomeric G-protein RhoA and its effector Rho-associated kinase I (ROCKI), which are known to play important roles in cardiovascular physiology, were also upregulated in neonatal rat ventricular myocytes subjected to hypoxia. Pharmacological experiments indicated that both proteins were involved in the observed upregulation of the Cav 3.2 channel and the stabilization of HIF-1α that occurred in response to hypoxia. These results suggest a possible role for Cav 3.2 channels in the increased probability of developing arrhythmias observed in ischaemic situations, and in the pathogenesis of diseases associated with hypoxic Ca(2+) overload.

[Assessment of an educational maze for major trauma care teaching]. / Évaluation d'un labyrinthe pédagogique pour l'enseignement de la traumatologie grave.

BACKGROUND: Assess efficacy, satisfaction and usefulness of an educational maze based on posters and audioguide for major trauma care teaching to medical students. The educational maze consists of posters with audio comments recorded in an audioguide. This tool was part of a larger educational program including medical simulation. STUDY DESIGN: Prospective, interventional, observational, monocentric study. STUDENT: Medical student of Grenoble University Hospital, in the four last years of medical school, following a training course in anesthesia, emergency medical services and intensive care units. METHOD: Forty essentials key messages for major trauma management were included in 10 posters and audioguides. A first assessment with short opened answers was handed to the students at the end of the educational maze to assess their memorization. A second assessment with simple choice answers regarding satisfaction and usefulness of this new educational tool was realized at the end of the entire program. RESULT: One hundred and eighty-four medical students attending the major trauma program were included in this study. On the first test, 75% of essential knowledge on major trauma management was memorized by more than 50% of the medical students. On the second test, 94% of medical students had a high satisfaction level of this educational maze. CONCLUSION: An educational maze based on posters and audioguides seems to be an efficient, useful tool for teaching essential knowledge on major trauma management to medical students.

Phylogenetic evidence for a recent spread of two populations of human enterovirus 71 in European countries.

Human enterovirus 71 (EV-71) is a cause of seasonal epidemics of hand, foot and mouth disease, and of less common but severe neurological manifestations. Uncertainty persists regarding the circulation of virus populations in several geographical areas and the timescale of their dissemination. We determined EV-71 sequences at loci 1D (VP1 capsid protein) and 3CD (non-structural proteins) in 86 strains recovered in Austria, France and Germany and performed an evolutionary genetic study of extant virus populations. Phylogenetic analyses positioned 78 of the 86 sequences within two clades among subgenogroups C1 and C2. A minor sequence cluster was assigned to subgenogroup C4. Analyses incorporating the available sequences estimated the substitution rate in genogroup C at 3.66 x 10(-3) and 4.46 x 10(-3) substitutions per site year(-1) for loci 1D and 3CD, respectively, assuming a relaxed molecular-clock model for sequence evolution. Most of the 'European' strains belonged to clades C1b and C2b, which originated in 1994 [95 % confidence interval (CI), 1992.7-1995.8] and 2002 (95 % CI, 2001.6-2003.8), respectively. Estimates of divergence times for locus 3CD were consistent with those measured for locus 1D. Intertwining between clades representing EV-71 subgenogroups and clades corresponding to other enterovirus types (notably early coxsackievirus A prototype strains) in the 3CD phylogeny is highly indicative of ancestral recombination events. Incongruent phylogenetic patterns estimated for loci 1D and 3CD show that a single tree cannot model the epidemic history of circulating EV-71 populations. The evolutionary timescale of genogroup C estimated for both loci was measured only in decades, indicating recent dissemination.

Digestibilidade aparente de rações contendo complexo enzimático para tilápia-do-nilo / Apparent digestibility of diets containing enzyme supplement for Nile tilapia

Avaliou-se a digestibilidade aparente de cinco rações isoproteicas e isoenergéticas contendo 0; 0,1; 0,2; 0,3 e 0,4g do complexo enzimático Bioenzimaplus (lipase, protease e carboidrase)/kg de ração na alimentação da tilápia-do-nilo. Foram utilizados 100 peixes distribuídos em cinco aquários de alimentação e cinco aquários de coleta de fezes. Os cinco tratamentos foram arranjados em delineamento inteiramente ao acaso com cinco repetições. Houve efeito linear de tratamento sobre a digestibilidade aparente (CDa) para proteína bruta e extrato etéreo. O CDa da proteína bruta e do extrato etéreo variaram de 81,60 por cento a 84,93 por cento e de 74,19 por cento a 82,69 por cento, respectivamente. Para carboidrato e energia bruta, o maior nível de suplementação resultou em maior CDa, 57,85 por cento e 63,78 por cento, respectivamente( P<0,05). Não foi observada diferença entre tratamentos no CDa da matéria seca, apresentando valores de 49,47 por cento a 58,55 por cento. A inclusão de complexo enzimático - lipase, protease e carboidrase - em dietas para tilápia-do-nilo melhorou a digestibilidade da proteína, do extrato etéreo, do carboidrato e da energia das rações.

Apparent digestibility (ADC) of five isoproteic and isoenergetic diets containing 0, 0.1, 0.2, 0.3, and 0.4g/kg of enzymatic complex Bioenzimaplus (lipase, protease, and carbohydrase) for Nile tilapia was evaluated. A hundred fish were randomly assigned in five feeding aquaria, and five collecting feces ones. Treatments were composed by five enzymatic complex levels arranged in a completely randomized design in five repetitions. Significant differences (P<0.05) were observed with the inclusion of enzymatic complex in the diets for ADC of crude protein and fat (linear effect). ADC of crude protein and fat varied from 81.60 percent to 84.94 percent and 74.19 percent to 85.69 percent, respectively. The highest enzyme supplementation level showed better digestibility values for carbohydrate and gross energy (57.85 percent and 63.78 percent, respectively). No difference was observed for ADC of dry matter showing values between 49.47 percent and 58.55 percent. The use of enzymes in Nile tilapia diets improved the digestibilities of protein, fat, carbohydrate, and gross energy digestibility.

[Vascular Ehlers-Danlos syndrome: a clinical syndrome to be known by every anaesthesiologist and intensive care physician]. / Syndrome d'Ehlers-Danlos de type vasculaire : une entité à connaître des anesthésistes-réanimateurs.

We report the case of a 29-year-old female who presented with a series of major vascular complications in rapid succession: haemothorax following rupture of a mammary artery aneurysm, pulmonary embolism, anterior myocardial infarction secondary to spontaneous dissection of the left anterior descending artery and rupture of a false aneurysm of the splenic artery. A diagnosis of Ehlers-Danlos syndrome (vascular variant) was considered the most likely in this context. Characterized by an extreme vascular fragility, this rare disease poses important clinical management issues for the anaesthetist and intensive care physician.

[Damage control laparotomy for haemorragic abdominal trauma. A retrospective multicentric study about 109 cases]. / La laparotomie écourtée dans les traumatismes abdominaux hémorragiques. Etude multicentrique rétrospective sur 109 cas.

AIM OF THE STUDY: Damage control laparotomy is a new approach to the more severe abdominal traumas. It stems from a better understanding of the physiopathology of the haemorragic shock. PATIENTS AND METHODS: A national retrospective study from 27 centers about 109 trauma patients who underwent a damage control procedure between January 1990 and December 2001, is analysed. Surgical procedures included 97 hepatic packing, 10 abdominal packing, 4 exclusive skin closure, 1 open laparotomy technique and 3 digestive stapplings. RESULTS: The mortality rate is 42%. Eleven abdominal compartment syndromes have occurred with 7 decompressive laparomy (4 deaths). CONCLUSION: This study is based on the largest series of damage control laparotomy published in France. Results in terms of mortality and morbidity are similar to those of published studies from the USA.

[Brain oedema following blood-brain barrier disruption: mechanisms and diagnosis]. / Oedème cérébral par lésion de la barrière hématoencéphalique: mécanismes et diagnostic.

Brain oedema following blood-brain barrier (BBB) disruption, or vasogenic oedema, is present in most cases of brain oedema. According to the Starling's law, water, ions and plasma proteins cross the BBB toward the interstitium if the driving forces for transmural bulk flow are excessive (mechanical origin) and/or if the BBB permeability is enhanced (chemical origin). Both mechanisms coexist in most cases. Excessive elevation of the gradient of hydrostatic pressure with lost of cerebral autoregulation has been proved in ischaemia/reperfusion and trauma, and suggested in acute mountain sickness and eclampsia. The BBB permeability can be enhanced by immediate (chemical mediators) or delayed (cellular infiltration) inflammatory response, or by alteration of the membrane integrity. This later can be transient (hyperosmolar BBB disruption), or permanent by activation of matrix metalloproteinase or by neovascularization with BBB breakdown. The reference method for the diagnosis of vasogenic oedema is the MRI diffusion-weighted imaging.

[Evaluating the quality of the anesthetic records]. / Evaluation de la tenue du dossier d'anesthésie.

OBJECTIVE: To assess the quality of the anaesthetic record for surgical and non surgical procedures and for elective and emergency surgery. STUDY DESIGN: Retrospective study in a university hospital. MATERIAL AND METHODS: Anaesthetic records collected over one month were analysed. The record included a referential with 38 items: nine for the identification of the patient and those who completed the record, 16 for the preoperative period and 13 for the operative period. Each item was qualified either as present (or correct), or absent, or unreadable or not applicable. RESULTS: Overall, 2,422 anaesthesia records were analysed, including 88,732 items. The mean level of correct items was 72%, and 1% of them were unreadable. Items for identification were significantly more correctly recorded (86%) than those concerning the preoperative (63%) and the operative (73%) periods (P < 0.01). Anaesthetic data for surgical procedures were significantly more correctly recorded (73%) than those for non-surgical procedures (63%) and surgery under local anaesthesia (52%; P < 0.01). Emergency surgical procedures were significantly less correctly recorded than elective ones (70 vs. 72%; P < 0.01). CONCLUSIONS: These results suggest that the quality of the anaesthetic records should be improved, mainly for the preoperative period and for non-surgical procedures.