bak deletion stimulates gastric epithelial proliferation and enhances Helicobacter felis-induced gastric atrophy and dysplasia in mice

Helicobacter infection causes a chronic superficial gastritis that in some cases progresses via atrophic gastritis to adenocarcinoma. Proapoptotic bak has been shown to regulate radiation-induced apoptosis in the stomach and colon and also susceptibility to colorectal carcinogenesis in vivo. Therefore we investigated the gastric mucosal pathology following H. felis infection in bak-null mice at 6 or 48 wk postinfection. Primary gastric gland culture from bak-null mice was also used to assess the effects of bak deletion on IFN-γ-, TNF-α-, or IL-1β-induced apoptosis. bak-null gastric corpus glands were longer, had increased epithelial Ki-67 expression, and contained fewer parietal and enteroendocrine cells compared with the wild type (wt). In wt mice, bak was expressed at the luminal surface of gastric corpus glands, and this increased 2 wk post-H. felis infection. Apoptotic cell numbers were decreased in bak-null corpus 6 and 48 wk following infection and in primary gland cultures following cytokine administration. Increased gastric epithelial Ki-67 labeling index was observed in C57BL/6 mice after H. felis infection, whereas no such increase was detected in bak-null mice. More severe gastric atrophy was observed in bak-null compared with C57BL/6 mice 6 and 48 wk postinfection, and 76% of bak-null compared with 25% of C57BL/6 mice showed evidence of gastric dysplasia following long-term infection. Collectively, bak therefore regulates gastric epithelial cell apoptosis, proliferation, differentiation, mucosal thickness, and susceptibility to gastric atrophy and dysplasia following H. felis infection

The gatekeeper: individual differences are key in the chain from perception to behaviour

A basic assumption in mainstream social cognition is that the path from perception to behaviour is often automatic and direct, as supported for example by several experimental studies showing that priming can lead directly to a congruent behaviour without any need of conscious awareness of the process. However, we argue that the priming of a goal or an object activates individual differences in automatic evaluations at the associative level that in turn are the key predictors of action (gatekeeper model). A study (n = 90) on the American stereotype is presented to support the model. The results show that individual differences of the American stereotype as assessed with the IAT predicts a relevant action (essay evaluation) but only under condition of priming. Broader implications for predictive validity of implicit measures are also discussed

Dispersion strengthening in vanadium microalloyed steels processed by simulated thin slab casting and direct charging. Part 2 - chemical characterisation of dispersion strengthening precipitates

The composition of the sub-15 nm particles in six related vanadium high strength low alloy steels, made by simulated thin slab direct charged casting, has been determined using electron energy loss spectroscopy (EELS). Such particles are considered to be responsible for dispersion hardening. For the first time, particles down to 4 nm in size have had their composition fully determined. In all the steels, the particles were nitrogen and vanadium rich and possibly slightly sub-stoichiometric carbonitrides. Equilibrium thermodynamics predicted much higher carbon to metal atomic ratios than observed in all cases so that kinetics and mechanical deformation clearly control the precipitation process. Thus it is important to formulate the steel with this in mind

Three-Wheel Brush-Wheel Sampler

A new sampler is similar to a common snow blower, but is robust and effective in sample collection. The brush wheels are arranged in a triangle shape, each driven by a brushless DC motor and planetary gearhead embedded in the wheel shaft. Its speed can be varied from 800 - 2,000 rpm, depending on the surface regolith resistance. The sample-collecting flow path, and internal features, are designed based on flow dynamics, and the sample-collecting rates have consistently exceeded the requirement under various conditions that span the range of expected surface properties. The brush-wheel sampler (BWS) is designed so that the flow channel is the main body of the apparatus, and links the brush-wheel assembly to the sample canister. The combination of the three brush wheels, the sample flow path, and the canister location make sample collection, storage, and transfer an easier task

Oral iron exacerbates colitis and influences the intestinal microbiome

Inflammatory bowel disease (IBD) is associated with anaemia and oral iron replacement to correct this can be problematic, intensifying inflammation and tissue damage. The intestinal microbiota also plays a key role in the pathogenesis of IBD, and iron supplementation likely influences gut bacterial diversity in patients with IBD. Here, we assessed the impact of dietary iron, using chow diets containing either 100, 200 or 400 ppm, fed ad libitum to adult female C57BL/6 mice in the presence or absence of colitis induced using dextran sulfate sodium (DSS), on (i) clinical and histological severity of acute DSS-induced colitis, and (ii) faecal microbial diversity, as assessed by sequencing the V4 region of 16S rRNA. Increasing or decreasing dietary iron concentration from the standard 200 ppm exacerbated both clinical and histological severity of DSS-induced colitis. DSS-treated mice provided only half the standard levels of iron ad libitum (i.e. chow containing 100 ppm iron) lost more body weight than those receiving double the amount of standard iron (i.e. 400 ppm); p<0.01. Faecal calprotectin levels were significantly increased in the presence of colitis in those consuming 100 ppm iron at day 8 (5.94-fold) versus day-10 group (4.14-fold) (p<0.05), and for the 400 ppm day-8 group (8.17-fold) versus day-10 group (4.44-fold) (p<0.001). In the presence of colitis, dietary iron at 400 ppm resulted in a significant reduction in faecal abundance of Firmicutes and Bacteroidetes, and increase of Proteobacteria, changes which were not observed with lower dietary intake of iron at 100 ppm. Overall, altering dietary iron intake exacerbated DSS-induced colitis; increasing the iron content of the diet also led to changes in intestinal bacteria diversity and composition after colitis was induced with DSS

Does depression in chronic obstructive pulmonary disease predict attendance and exercise compliance during pulmonary rehabilitation, and exercise levels maintained 9 months later

La maladie pulmonaire obstructive chronique (MPOC) est une maladie respiratoire irréversible, évolutive et très fréquente qui fait peser un lourd fardeau sur le système de santé, les patients et leurs proches. La réadaptation pulmonaire (RP) est efficace pour réduire la dyspnée et l’utilisation des ressources en soins de santé et pour améliorer la capacité physique et la qualité de vie des patients. L’entraînement physique est la pierre angulaire de la RP, mais elle n’est bénéfique que si les patients 1) assistent aux séances d’exercice, 2) se conforment à l'intensité des exercices prescrits et 3) maintiennent l'exercice physique régulier après la RP. La dépression comorbide est disproportionnée dans la MPOC et s’est révélée être un facteur prédictif de « mauvaise » fréquentation de la RP, et d'abandon de la pratique physique régulière après le programme. À notre connaissance, aucune étude ne s'est intéressée aux prédicteurs de conformité à l'intensité d'exercice prescrit pendant la RP et seules quelques études ont explorées les facteurs associés au maintien de l'exercice après la RP. L’objectif principal de cette étude consistait à examiner dans quelle mesure les symptômes dépressifs à l'entrée de la RP permettent de prédire 1) la présence aux séances de RP, 2) le respect de l'intensité (conformité) des exercices d’endurance prescrits pendant la RP, et 3) le niveau d’exercice physique maintenu 9 mois après la RP. Un deuxième objectif consistait à explorer d'autres variables susceptibles d'être associées à ces paramètres. Trente-six patients (64 % de femmes) atteints de la MPOC stable, modérée à sévère, ont été inscrits à un programme de RP de 12 semaines comportant 36 séances d’exercice physique supervisé. À l’entrée du RP les patients ont rempli l’Inventaire de Dépression de Beck (BDI-II, le prédicteur principal) et le formulaire C de l’Échelle du locus de contrôle sur la santé (LCS), et ont subi des tests de fonction pulmonaire et une épreuve d’effort progressif à vélo (pour déterminer l'intensité de l'exercice pour la RP). Ensuite, ils ont été répartis de façon aléatoire dans trois groupes à intensité d’exercice différente. La fréquentation de la RP était définie comme le pourcentage de séances suivies; la conformité, comme la durée d’entraînement pratiquée à la fréquence cardiaque cible; et le maintien de l'exercice physique régulier comme le niveau d’exercice fait au cours d’une semaine 9 mois après la RP (enregistré dans un journal d’activité physique et calculé en équivalents métaboliques de l’effort [MET] minutes ). La médiane (écart interquartile ou IQR) du score au BDI-II était de 8,5 points (6-13), la médiane (IQR) du taux de la fréquentation aux séances était de 83% (67-94), la médiane du taux de compliance à l’intensité d'exercice était de 94% (71-99), et la médiane du nombre de minutes MET après la RP était de 706 (445-1146). Les analyses de régression linéaire ne montrent pas de relation entre les symptômes dépressifs pré-RP et la fréquentation des séances de la RP (ß = 0,12; p = 0,478). Par-contre, ils étaient associés à la conformité à l'intensité de l’exercice physique pendant la RP (ß = -0,40; p = 0,047), et à la poursuite de la pratique d’un exercice physique régulier après la RP (ß = -0,50; p = 0,004). Les analyses étaient ajustées pour des covariables prédéfinies. Les analyses exploratoires ont révélé que certaines variables supplémentaires (y compris LCS) étaient associées aux issues mesurées. Les résultats de cette étude montrent que même les niveaux de dépression sous-cliniques pourraient jouer un rôle important dans la compliance aux programme de réentraînement, et au maintien d’un style de vie actif après la période de réadaptation. Cela a des implications pour améliorer le dépistage des « mauvais » résultats dans la RP et pour l'élaboration d'interventions ciblées pour améliorer les bénéfices pour la santé découlant de la réadaptation pour la MPOC.Abstract : Chronic obstructive pulmonary disease (COPD) is an irreversible, progressive, and highly prevalent respiratory illness that poses a great burden on the healthcare system, patients, and their families. Pulmonary rehabilitation (PR) is effective in reducing dyspnea and health care resource utilization, and increasing exercise capacity and quality of life. Exercise training is the cornerstone of PR but is only beneficial if patients 1) attend sessions, 2) comply with the prescribed exercise regimen, and 3) maintain regular exercise after supervised PR ends. Comorbid depression is disproportionately high in COPD and has been found to predict poor attendance at PR and low levels of exercise maintained afterwards. To our knowledge, no study has investigated predictors of exercise compliance during PR, and only a few studies have examined predictors of exercise maintenance post PR. The primary objective of this study was to examine how much baseline depressive symptomatology can predict 1) PR attendance, 2) PR exercise compliance, and 3) levels of exercise maintained at 9-months post PR. A secondary, exploratory objective was to identify additional variables that might also have significant associations with these outcomes. Thirty-six patients (64% female) with stable COPD were enrolled in a 12-week 36-session supervised exercise intervention in the context of a PR program. Patients underwent evaluations at entry to PR which included the Beck Depression Inventory (BDI-II, the main predictor), the Multidimensional Health Locus of Control (HLC) Scale Form-C, pulmonary function tests, and an incremental cycling test (to determine the exercise intensity prescription). Patients were randomized to one of three groups of varying exercise intensity. Attendance was defined as the percent of total sessions attended, compliance as the percent of endurance training time exercising at a prescribed target heart rate, and post-PR exercise as the total exercise performed over a 7-day period recorded in a physical activity diary and calculated as metabolic equivalent of task (MET) minutes. Median (IQR) baseline BDI-II was 8.5 (6-13), median (IQR) percent attendance was 83 (67-94), median (IQR) percent exercise compliance was 94 (71-99), and median (IQR) exercise MET-minutes post PR was 706 (445-1146). In multiple regression analyses, baseline depressive symptomatology did not emerge as a significant independent predictor of PR attendance (ß = .12, p = .478), but was a significant predictor of PR exercise compliance (ß = -.40, p = .047), and of exercise maintained post PR (ß = -.50, p = .004), with adjustment for a-priori defined covariates. Secondary exploratory analyses revealed that certain additional variables (including HLC) had associations with particular outcomes. The findings suggest that even subclinical levels of depression can predict PR exercise compliance and post-PR exercise levels. This has implications for improving screening for, and understanding of, poor outcomes in PR and for developing targeted interventions to optimize the health benefits that can be derived during and after PR for COPD