L’analyse de la relation hôte–microbiote doit prendre en compte le microbiote intestinal, la barrière intestinale et la translocation bactérienne.
Des données expérimentales démontrent le rôle causal ...de la relation hôte–microbiote dans la régulation de la pression artérielle, de l’homéostasie métabolique et le développement de l’athérosclérose.
Chez l’homme, la relation hôte–microbiote est associée à l’hypertension artérielle, au diabète et la survenue des évènements cardiovasculaires.
Chez l’homme, la relation hôte–microbiote est associée à la survenue des maladies cardiovasculaires.
La diète méditerranéenne a démontré avec un fort niveau de preuve un effet sur le microbiote intestinal et sur la réduction du risque cardiovasculaire.
When analyzing the microbiota-host crosstalk, we have to consider three participants in this dialogue: the gut microbiota, the intestinal barrier and bacterial translocation.
Experimental data demonstrate that host microbiota crosstalk plays a causal on the regulation of blood pressure, glucose metabolism and the development of atherosclerosis.
Host microbiota crosstalk is associated in humans with main cardiovascular risk factors notably hypertension and type 2 diabetes.
Host microbiota crosstalk is associated in humans with the onset of cardiovascular diseases.
The Mediterranean diet has proven as proven to be an effective strategy in improving cardiovascular prognosis and in changing gut microbiota.
•Deposition on the (111) surface leads to a significant excess Te sticking probability.•Deposition on the (100) surface leads to much smaller excess Te sticking probability.•Deposition on the (100) ...surface leads to interstitials in the surface layer.
Cadmium Telluride (CdTe) is an important material for the production of high-efficiency thin-film solar cells. While sputter deposition has been used to create CdTe-based solar cells, two other important methods of growth are close-spaced sublimation and vapor deposition. In these methods, the depositing clusters correspond to Cd atoms and Te2 dimers while the deposition energies are relatively low. In addition, depending on vapor pressure, deposition method, and target-substrate distance, deposition may occur at relatively large angles with respect to the substrate normal. Here we investigate the dependence of the attachment probability and deposition site for Cd and Te2 clusters deposited on Cd-terminated and Te-terminated (100) and (111) surfaces of zincblende CdTe on deposition conditions. In general, we find that the deposition of Cd atoms and/or Te2 dimers on the oppositely terminated surface leads to an attachment probability which is close to 1 and relatively independent of deposition conditions for both the (100) and (111) orientations. In contrast, deposition on the same terminated surface leads to a significantly lower attachment probability which generally decreases with increasing deposition angle, energy, and substrate temperature. Our results also indicate that deposition on the (111) surface leads to a significant excess Te sticking probability. In contrast, the excess Te attachment probability for deposition on the (100) surface is typically significantly smaller, and in some cases may even be negative. We also find, for both deposition on the (111) surface as well as opposite termination deposition on the (100) surface, that the dominant deposition mode corresponds to sitting on top of the surface which corresponds to growth of the next layer. In contrast, for same termination deposition on the (100) surface the dominant deposition mode corresponds to joining the first layer. These results imply that even for low deposition energies and substrate temperatures, deposition on the (100) surface is likely to create interstitials in the surface layer.
We have generalized and implemented the hybrid asynchronous algorithm, originally proposed for parallel simulations of the spin-flip Ising model, in order to carry out parallel kinetic Monte Carlo ...(KMC) simulations. The parallel performance has been tested using a simple model of thin-film growth in both 1D and 2D. We also briefly describe how the data collection must be modified as compared to the case of the spin-flip Ising model in order to carry out rigorous data collection. Due to the presence of a wide range of rates in the simulations, this algorithm turns out to be very inefficient. The poor parallel performance results from three factors: (1) the high probability of selecting a Metropolis Monte Carlo (MMC) move, (2) the low acceptance probability of boundary moves and (3) the high cost of communications which is required before every MMC move. We also find that the parallel efficiency in two dimensions is lower than in one-dimension due to the higher probability of selecting an MMC attempt, suggesting that this algorithm may not be suitable for KMC simulations of two-dimensional thin-film growth.
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•Simple patient data can evaluate the probability that LVH is of hypertensive origin.•Machine learning algorithms achieve this with high accuracy.•Online calculators have been made ...publicly available.
Left ventricular hypertrophy is often associated with hypertension, which is not necessarily the cause of hypertrophy. Non-hypertension-related aetiologies often have a strong impact on patient management, and therefore require a thorough and careful workup. When considering all left ventricular hypertrophies, even the mild ones, the number of patients who need a workup increases drastically. This raises the need for a tool to evaluate the pretest probability of the origin of left ventricular hypertrophy.
To predict the hypertensive origin of left ventricular hypertrophy using machine learning on first-line clinical, laboratory and echocardiographic variables.
We used a retrospective single-centre population of 591 patients with left ventricular hypertrophy, starting at 12mm maximal left ventricular wall thickness. After splitting data in a training and testing set, we trained three different algorithms: decision tree; random forest; and support vector machine. Model performances were validated on the testing set.
All models exhibited good areas under receiver operating characteristic curves: 0.82 (95% confidence interval: 0.77–0.88) for the decision tree; 0.90 (95% confidence interval 0.85–0.94) for the random forest; and 0.90 (95% confidence interval: 0.85–0.94) for the support vector machine. After threshold selection, the last model had the best balance between its specificity of 0.96 (95% confidence interval: 0.91–0.99) and its sensitivity of 0.31 (95% confidence interval: 0.17–0.44). All algorithms relied on similar most influential predictor variables. Online calculators were developed and made publicly available.
Machine learning models were able to determine the hypertensive origin of left ventricular hypertrophy with good performances. Implementation in clinical practice could reduce the number of aetiological workups needed in patients presenting with left ventricular hypertrophy.
Vascular endothelial growth factor (VEGF) proteins are involved in the regulation of angiogenesis. Systemic adverse effects of some anti‐VEGF include hypertension, proteinuria and cardiovascular ...complications which could involve lower systemic VEGF levels. However, the question regarding intravitreal administration of anti‐VEGF remains controversial given that the patients receiving these drugs are often elderly and present cardiac risk factors such as arterial hypertension or atrial fibrillation. We report a case of hypertensive flare‐up following intravitreal injection of ranibizumab for retinal vein occlusion. The outcome was favourable after adapted antihypertensive treatment. This case report adds to the growing body of evidence suggesting that intravitreal administration of anti‐VEGF, regardless of agents, may result in hypertensive episodes in some predisposed patients. Listing this adverse effect should help to minimize risks by heightening clinician and patient awareness and to improve blood pressure monitoring following the intravitreal administration of anti‐VEGF agents.
The early detection of liver fibrosis among patients with nonalcoholic fatty liver disease (NAFLD) is an important clinical need. In view of the suggested role played by bacterial translocation in ...liver disease and obesity, we sought to investigate the relationship between blood microbiota and liver fibrosis (LF) in European cohorts of patients with severe obesity. We carried out a cross‐sectional study of obese patients, well characterized with respect to the severity of the NAFLD, in the cohort FLORINASH. This cohort has been divided into a discovery cohort comprising 50 Spanish patients and then in a validation cohort of 71 Italian patients. Blood bacterial DNA was analyzed both quantitatively by 16S ribosomal DNA (rDNA) quantitative polymerase chain reaction and qualitatively by 16S rDNA targeted metagenomic sequencing and functional metagenome prediction. Spanish plasma bile acid contents were analyzed by liquid chromatography/mass spectrometry. The 16S rDNA concentration was significantly higher in patients of the discovery cohort with LF. By 16S sequencing, we found specific differences in the proportion of several bacterial taxa in both blood and feces that correlate with the presence of LF, thus defining a specific signature of the liver disease. Several secondary/primary bile acid ratios were also decreased with LF in the discovery cohort. We confirmed, in the validation cohort, the correlation between blood 16S rDNA concentration and LF, whereas we did not confirm the specific bacterial taxa signature, despite a similar trend in patients with more‐severe fibrosis. Conclusion: Changes in blood microbiota are associated with LF in obese patients. Blood microbiota analysis provides potential biomarkers for the detection of LF in this population. (Hepatology 2016;64:2015‐2027).
Cross-sectional studies have shown a positive association between increased pulse pressure (PP) and an increased likelihood of a C-reactive protein (CRP) level >3 mg/L. In a retrospective subgroup ...analysis of the hypertensive subjects of the multicenter double-blind study, REASON (PREterax in Regression of Arterial Stiffness in a ContrOlled Double-BliNd), in which fixed first-line antihypertensive combination therapy with an angiotensin converting enzyme (ACE) inhibitor, perindopril (2 mg), and a diuretic, indapamide (0.625 mg), proved significantly more effective than atenolol in normalizing PP, we sought to determine whether perindopril plus indapamide was also more effective than atenolol in lowering CRP levels and, if so, whether this effect correlated with a preferential reduction in PP. At the final visit (12 months) in the 269 patients studied, the decrease in PP was greater, and the proportion of patients with CRP >3 mg/L lower (17.9% versus 28. 9%, P=0.03; adjusted odds ratio, 1.02 to 4.08, P=0.01), in the perindopril plus indapamide group than in the atenolol group. After adjustment for confounders, patients with a baseline CRP >3 mg/L displaying the greatest decrease in PP were more likely (P=0.04) to have a CRP < or =3 mg/L at 12 months. No such relationship was found with systolic or diastolic blood pressure. Perindopril-indapamide combination therapy is more effective than beta-blockade in lowering elevated CRP in hypertensive subjects. This effect is significantly associated with a more effective PP reduction in patients with baseline CRP >3 mg/L.
The gut microbiota, which is considered a causal factor in metabolic diseases as shown best in animals, is under the dual influence of the host genome and nutritional environment. This study ...investigated whether the gut microbiota per se, aside from changes in genetic background and diet, could sign different metabolic phenotypes in mice.
The unique animal model of metabolic adaptation was used, whereby C57Bl/6 male mice fed a high-fat carbohydrate-free diet (HFD) became either diabetic (HFD diabetic, HFD-D) or resisted diabetes (HFD diabetes-resistant, HFD-DR). Pyrosequencing of the gut microbiota was carried out to profile the gut microbial community of different metabolic phenotypes. Inflammation, gut permeability, features of white adipose tissue, liver and skeletal muscle were studied. Furthermore, to modify the gut microbiota directly, an additional group of mice was given a gluco-oligosaccharide (GOS)-supplemented HFD (HFD+GOS).
Despite the mice having the same genetic background and nutritional status, a gut microbial profile specific to each metabolic phenotype was identified. The HFD-D gut microbial profile was associated with increased gut permeability linked to increased endotoxaemia and to a dramatic increase in cell number in the stroma vascular fraction from visceral white adipose tissue. Most of the physiological characteristics of the HFD-fed mice were modulated when gut microbiota was intentionally modified by GOS dietary fibres.
The gut microbiota is a signature of the metabolic phenotypes independent of differences in host genetic background and diet.
A high-fat diet (HFD) induces metabolic disease and low-grade metabolic inflammation in response to changes in the intestinal microbiota through as-yet-unknown mechanisms. Here, we show that a ...HFD-derived ileum microbiota is responsible for a decrease in Th17 cells of the lamina propria in axenic colonized mice. The HFD also changed the expression profiles of intestinal antigen-presenting cells and their ability to generate Th17 cells in vitro. Consistent with these data, the metabolic phenotype was mimicked in RORγt-deficient mice, which lack IL17 and IL22 function, and in the adoptive transfer experiment of T cells from RORγt-deficient mice into Rag1-deficient mice. We conclude that the microbiota of the ileum regulates Th17 cell homeostasis in the small intestine and determines the outcome of metabolic disease.
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•HFD-induced T2D decreases the number of ileum IL17/RORγt CD4 T cells•IL17/RORγt-deficient CD4 T cells induce T2D and obesity•HFD-induced ileum microbiota dysbiosis lowers intestinal IL17/RORγt-CD4 T cells•HFD reduces antigen presenting cell ability to induce Th17 cell differentiation
Obesity and type 2 diabetes have been linked to the gut microbiota. Garidou et al. show that a high-fat diet induces gut microbiota dysbiosis which impairs the intestinal immune defense, including reduced intestinal IL 17 T cells. The intestinal immunity changes precede the onset of diabetes.
Soluble CD14 (sCD14), an effective mediator for the activation of monocytes by bacterial endotoxin is involved in the release of substances able to modify the characteristics of the arterial wall. ...The aim of this study was to investigate, in humans, the relationship of sCD14 with aortic stiffness and to analyse the influence of arterial structure and endothelial function on this relationship.
Cross-sectional population-based study.
One thousand and fifteen subjects randomly selected from the polling lists, were recruited by the Toulouse MONICA centre between 1995 and 1997.
Carotid-femoral pulse wave velocity (PWV) and blood pressure (BP) were measured in the supine position. Common carotid intima-media thickness (IMT) and the presence of plaques were assessed by ultrasonography. sCD14 was measured using an immunoenzymatic method.
The results concern the 891 subjects with complete data for all the variables. In the bivariate analyses, PWV (P < 0.001), systolic BP (P < 0.05), pulse pressure (PP) (P < 0.01), IMT (P < 0.001), the number of plaques (P < 0.05) and von Willebrand factor activity (vWFa) (P < 0.001) were positively associated with sCD14, whereas no significant relationship was observed between sCD14 and diastolic BP. After adjustment for age and sex, no significant relationship remained between IMT, the number of plaques, SBP, PP and sCD14. A significant and positive relationship was observed between sCD14 and PWV (trend P < 0.05) after adjustment for numerous confounders.
This population-based study yields first evidence that sCD14 is associated with aortic stiffness independently of age, BP and atherosclerosis in humans.
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