Stress Impairs Skin Barrier Function and Induces α2-3 Linked N-Acetylneuraminic Acid and Core 1 O-Glycans on Skin Mucins in Atlantic Salmon, Salmo salar

The skin barrier consists of mucus, primarily comprising highly glycosylated mucins, and the epithelium. Host mucin glycosylation governs interactions with pathogens and stress is associated with impaired epithelial barrier function. We characterized Atlantic salmon skin barrier function during chronic stress (high density) and mucin O-glycosylation changes in response to acute and chronic stress. Fish held at low (LD: 14–30 kg/m3) and high densities (HD: 50-80 kg/m3) were subjected to acute stress 24 h before sampling at 17 and 21 weeks after start of the experiment. Blood parameters indicated primary and secondary stress responses at both sampling points. At the second sampling, skin barrier function towards molecules was reduced in the HD compared to the LD group (Papp mannitol; p < 0.01). Liquid chromatography–mass spectrometry revealed 81 O-glycan structures from the skin. Fish subjected to both chronic and acute stress had an increased proportion of large O-glycan structures. Overall, four of the O-glycan changes have potential as indicators of stress, especially for the combined chronic and acute stress. Stress thus impairs skin barrier function and induces glycosylation changes, which have potential to both affect interactions with pathogens and serve as stress indicators. View Full-TextpublishedVersio

Topological Sensitivity Analysis for a Nonlinear Case: the p-Poisson Problem

The topological derivative allow us to quantify the sensitivity of the problem when the domain under consideration is perturbed by the introduction of a hole. Extension of the topological derivative in order to include arbitrary shaped holes or inclusion and its applications to Laplace, Poisson, Helmoltz, Navier, Stokes and Navier-Stokes equations can be found in the literature. However, only linear problems or when the nonlinear term is a compact perturbation of the principal part of the operator have been considered. In the present paper, we propose a numerical procedure to estimate the topological derivative for a nonlinear case: the p-Poisson problem, considering the complementary dissipation energy as the cost function and the state equation in its weak form as the constraint. This problem is interesting because we are dealing with a case in which the nonlinear term involves the principal part of the operator. Finally, the obtained topological derivative is used to find the best place to insert holes in bars of different cross-sections submitted to torsion effects for several values of p. 2. Keywords: topological derivative, shape derivative, p-Poisson, topology design. The topological derivative has been recognized as a promising tool to solve topology optimization problem

Fish pathogen binding to mucins from Atlantic salmon and Arctic char differs in avidity and specificity and is modulated by fluid velocity.

Disease outbreaks are limiting factors for an ethical and economically sustainable aquaculture industry. The first point of contact between a pathogen and a host occurs in the mucus, which covers the epithelial surfaces of the skin, gills and gastrointestinal tract. Increased knowledge on host-pathogen interactions at these primary barriers may contribute to development of disease prevention strategies. The mucus layer is built of highly glycosylated mucins, and mucin glycosylation differs between these epithelial sites. We have previously shown that A. salmonicida binds to Atlantic salmon mucins. Here we demonstrate binding of four additional bacteria, A. hydrophila, V. harveyi, M. viscosa and Y. ruckeri, to mucins from Atlantic salmon and Arctic char. No specific binding could be observed for V. salmonicida to any of the mucin groups. Mucin binding avidity was highest for A. hydrophila and A. salmonicida, followed by V. harveyi, M. viscosa and Y. ruckeri in decreasing order. Four of the pathogens showed highest binding to either gills or intestinal mucins, whereas none of the pathogens had preference for binding to skin mucins. Fluid velocity enhanced binding of intestinal mucins to A. hydrophila and A. salmonicida at 1.5 and 2 cm/s, whereas a velocity of 2 cm/s for skin mucins increased binding of A. salmonicida and decreased binding of A. hydrophila. Binding avidity, specificity and the effect of fluid velocity on binding thus differ between salmonid pathogens and with mucin origin. The results are in line with a model where the short skin mucin glycans contribute to contact with pathogens whereas pathogen binding to mucins with complex glycans aid the removal of pathogens from internal epithelial surfaces

Elementary school physical activity opportunities and physical fitness of students: A statewide cross-sectional study of schools.

BackgroundUsing a cross-sectional design, we assessed the relationship between the time schools provide for physical activity and the proportion of students achieving a healthy aerobic capacity or body mass index.MethodsIn 2013-2014, physical education and grade-level teachers from 905 of 1,244 Georgia elementary schools provided survey data about the frequency and duration of physical activity opportunities offered before, during, and after school. Log-binomial models related the weekly physical activity minutes provided by schools to the proportion of children in the FitnessGram healthy fitness zone for aerobic capacity or body mass index while adjusting for school characteristics and demographics.ResultsDuring-school physical activity time was not associated with student fitness, but schools with before-school physical activity programs had a moderately higher prevalence of healthy aerobic capacity (prevalence ratio among girls: 1.06; 99% confidence interval: 1.00-1.13; prevalence ratio among boys: 1.03; 99% confidence interval: 0.99-1.08). Each additional 30 minutes of recess per week was associated with no more than a 3%-higher proportion of students with healthy body mass indexes (prevalence ratio among girls: 1.01; 99% confidence interval: 1.00-1.03; prevalence ratio among boys: 1.01; 99% confidence interval: 0.99-1.03).ConclusionsThe amount of physical activity time provided by schools is not strongly associated with school-aggregated student fitness. Future studies should be designed to assess the importance of school-based physical activity time on student fitness, relative to physical activity type and quality

Relationship Between Serum Paraoxonase and Homocysteine Thiolactonase Activity, Adipokines, and Asymmetric Dimethyl Arginine Concentrations in Renal Transplant Patients

ABSTRACTParaoxonase lactonase activity protects against homocysteinylation; therefore, it can be apotential contributing factor to prevent atherosclerosis. We aimed to determine paraoxonaseand HTLase activities and to clarify the relationship between HTLase activity andsome cardiovascular risk factors, such as homocysteine, cystatin C asymmetric dimethylarginine(ADMA), and adipokines both in hemo dialyzed and transplanted patients.Among 114 hemodialyzed, 80 transplanted and 64 healthy control subjects, we investigatedbody mass index (BMI) as well as fasting serum contents of urea, uric acid, creatinine,cystatin C, homocysteine, glucose, lipids, total protein and albumin. Serum paraoxonase(PON 1) and HTLase activities were measured spectrophotometrically. ADMA, ADPNadiponectin, leptin (LEP) levels was determined with a sandwich enzyme-linked immunosorbentassay method. Dyslipidemic patients showed hypercholesterolemia, and highlow-density lipoprotein (LDL); parallel with improved renal function, they displayeddecreased cystatin C and homocysteine levels (P < .001). There was a significant negativecorrelation between PON 1 activity and cystatin C and homocysteine concentrations(P < .05). Obese patients revealed significantly higher LDL (P < .05) and leptin concentrations(P < .01). There was a significant positive correlation between PON 1 activity andadiponectin levels (P ¼ .0276). Both dialyzed and transplanted patients displayed significantlylower HTLase activities compared to the control group (P < .001), particularly lowerHTLase and PON 1 activities in dialyzed subjects compared with the transplanted group(P < .05). HTLase activity showed significant negative correlations with ADMA levelsamong the whole study population (P < .001), whereas positive associations were notedbetween PON 1 and HTLase activities (P < .001). HTLase activity may be a new predictorof cardiovascular risk in renal failure although it is modulated by other risk factors

Smoking-associated increase in mucins 1 and 4 in human airways

Abstract Rationale: Smoking-related chronic obstructive pulmonary disease (COPD) is associated with dysregulated production of mucus. Mucins (MUC) are important both for mucus secretion and epithelial defense. We have examined the distribution of MUC1 and MUC4 in the airway epithelial cells of never-smokers and smokers with and without COPD. Methods: Mucosal biopsies and bronchial wash samples were obtained by bronchoscopy from age- and sex-matched COPD-patients (n = 38; GOLD I-II/A-B), healthy never-smokers (n = 40) and current smokers with normal lung function (n = 40) from the Karolinska COSMIC cohort (NCT02627872). Cell-specific expressions of MUC1, MUC4 and regulating factors, i.e., epithelial growth factor receptor (EGFR) 1 and 2, were analyzed by immunohistochemistry. Soluble MUC1 was measured by quantitative immunodetection on slot blot. Results: The levels of cell-bound MUC1 expression in basal cells and in soluble MUC1 in bronchial wash were increased in smokers, regardless of airway obstruction. Patients with chronic bronchitis had higher MUC1 expression. The expression of MUC4 in cells with goblet cell phenotype was increased in smokers. The expression of EGFR2, but not that of EGFR1, was higher in never-smokers than in smokers. Conclusions: Smoking history and the presence of chronic bronchitis, regardless of airway obstruction, affect both cellular and soluble MUC1 in human airways. Therefore, MUC1 may be a novel marker for smoking- associated airway disease

Stress Impairs Skin Barrier Function and Induces α2-3 Linked N-Acetylneuraminic Acid and Core 1 O-Glycans on Skin Mucins in Atlantic Salmon, Salmo salar

The skin barrier consists of mucus, primarily comprising highly glycosylated mucins, and the epithelium. Host mucin glycosylation governs interactions with pathogens and stress is associated with impaired epithelial barrier function. We characterized Atlantic salmon skin barrier function during chronic stress (high density) and mucin O-glycosylation changes in response to acute and chronic stress. Fish held at low (LD: 14–30 kg/m3) and high densities (HD: 50-80 kg/m3) were subjected to acute stress 24 h before sampling at 17 and 21 weeks after start of the experiment. Blood parameters indicated primary and secondary stress responses at both sampling points. At the second sampling, skin barrier function towards molecules was reduced in the HD compared to the LD group (Papp mannitol; p < 0.01). Liquid chromatography–mass spectrometry revealed 81 O-glycan structures from the skin. Fish subjected to both chronic and acute stress had an increased proportion of large O-glycan structures. Overall, four of the O-glycan changes have potential as indicators of stress, especially for the combined chronic and acute stress. Stress thus impairs skin barrier function and induces glycosylation changes, which have potential to both affect interactions with pathogens and serve as stress indicators. View Full-Tex