Effects of two physical education programmes on health- and skill-related physical fitness of Albanian children

This study aims to evaluate the effectiveness of two school-based physical education (PE) programmes (exercise-based and games-based) compared with traditional PE, on health- and skill-related physical fitness components in children in Tirana, Albania. Participants were 378 first-grade (6.8 years) and 389 fourth-grade (9.8 years) children attending four randomly selected schools in Tirana. Twenty-four school classes within these schools were randomly selected (stratified by school and school grade) to participate as exercise group (EG), games group (GG) and control group (CG). Both EG and GG intervention programmes were taught by professional PE teachers using station/circuit teaching framework while CG referred to traditional PE school lessons by a general teacher. All programmes ran in parallel and lasted 5 months, having the same frequency (twice weekly) and duration (45 min). Heart rate (HR) monitoring showed that intensity during PE lessons was significantly higher in the intervention groups compared with control (P < 0.001). Both PE exercise- and games programmes significantly improved several health- and skill-related fitness indicators compared with traditional PE lessons (e.g. gross motor skill summary score: 9.4 (95% CI 7.9; 10.9) for exercise vs. control and 6.5 (95% CI 5.1; 8.1) for games vs. control, cardiorespiratory fitness: 2.0 ml O2 · min(-1) · kg(-1) (95% CI 1.5; 2.4) for exercise vs. control and 1.4 ml O2 · min(-1) · kg(-1) (95% CI 1.0; 1.8) for games vs. control). Furthermore, compared to games-based PE, exercise-based PE showed more positive changes in some gross motor coordination skills outcomes, coordination skills outcomes and cardiorespiratory fitness. The results from this study show that exercise- and games-based PE represents a useful strategy for improving health- and skill-related physical fitness in Albanian elementary school children. In addition, the study shows that exercise-based PE was more effective than games-based PE in improving gross motor function and cardiorespiratory fitness.

Sox18 preserves the pulmonary endothelial barrier under conditions of increased shear stress

Shear stress secondary to increased pulmonary blood flow (PBF) is elevated in some children born with congenital cardiac abnormalities. However, the majority of these patients do not develop pulmonary edema, despite high levels of permeability inducing factors. Previous studies have suggested that laminar fluid shear stress can enhance pulmonary vascular barrier integrity. However, little is known about the mechanisms by which this occurs. Using microarray analysis, we have previously shown that Sox18, a transcription factor involved in blood vessel development and endothelial barrier integrity, is up-regulated in an ovine model of congenital heart disease with increased PBF (shunt). By subjecting ovine pulmonary arterial endothelial cells (PAEC) to laminar flow (20 dyn/cm(2) ), we identified an increase in trans-endothelial resistance (TER) across the PAEC monolayer that correlated with an increase in Sox18 expression. Further, the TER was also enhanced when Sox18 was over-expressed and attenuated when Sox18 expression was reduced, suggesting that Sox18 maintains the endothelial barrier integrity in response to shear stress. Further, we found that shear stress up-regulates the cellular tight junction protein, Claudin-5, in a Sox18 dependent manner, and Claudin-5 depletion abolished the Sox18 mediated increase in TER in response to shear stress. Finally, utilizing peripheral lung tissue of 4 week old shunt lambs with increased PBF, we found that both Sox18 and Claudin-5 mRNA and protein levels were elevated. In conclusion, these novel findings suggest that increased laminar flow protects endothelial barrier function via Sox18 dependent up-regulation of Claudin-5 expression.

Protective effect of Growth Hormone-Releasing Hormone agonist in bacterial toxin-induced pulmonary barrier dysfunction

RATIONALE

Antibiotic treatment of patients infected with G(-) or G(+) bacteria promotes release of the toxins lipopolysaccharide (LPS) and pneumolysin (PLY) in their lungs. Growth Hormone-releasing Hormone (GHRH) agonist JI-34 protects human lung microvascular endothelial cells (HL-MVEC), expressing splice variant 1 (SV-1) of the receptor, from PLY-induced barrier dysfunction. We investigated whether JI-34 also blunts LPS-induced hyperpermeability. Since GHRH receptor (GHRH-R) signaling can potentially stimulate both cAMP-dependent barrier-protective pathways as well as barrier-disruptive protein kinase C pathways, we studied their interaction in GHRH agonist-treated HL-MVEC, in the presence of PLY, by means of siRNA-mediated protein kinase A (PKA) depletion.

METHODS

Barrier function measurements were done in HL-MVEC monolayers using Electrical Cell substrate Impedance Sensing (ECIS) and VE-cadherin expression by Western blotting. Capillary leak was assessed by Evans Blue dye (EBD) incorporation. Cytokine generation in broncho-alveolar lavage fluid (BALF) was measured by multiplex analysis. PKA and PKC-α activity were assessed by Western blotting.

RESULTS

GHRH agonist JI-34 significantly blunts LPS-induced barrier dysfunction, at least in part by preserving VE-cadherin expression, while not affecting inflammation. In addition to activating PKA, GHRH agonist also increases PKC-α activity in PLY-treated HL-MVEC. Treatment with PLY significantly decreases resistance in control siRNA-treated HL-MVEC, but does so even more in PKA-depleted monolayers. Pretreatment with GHRH agonist blunts PLY-induced permeability in control siRNA-treated HL-MVEC, but fails to improve barrier function in PKA-depleted PLY-treated monolayers.

CONCLUSIONS

GHRH signaling in HL-MVEC protects from both LPS and PLY-mediated endothelial barrier dysfunction and concurrently induces a barrier-protective PKA-mediated and a barrier-disruptive PKC-α-induced pathway in the presence of PLY, the former of which dominates the latter.

Ezrin/radixin/moesin proteins differentially regulate endothelial hyperpermeability after thrombin

Endothelial cell (EC) barrier disruption induced by inflammatory agonists such as thrombin leads to potentially lethal physiological dysfunction such as alveolar flooding, hypoxemia, and pulmonary edema. Thrombin stimulates paracellular gap and F-actin stress fiber formation, triggers actomyosin contraction, and alters EC permeability through multiple mechanisms that include protein kinase C (PKC) activation. We previously have shown that the ezrin, radixin, and moesin (ERM) actin-binding proteins differentially participate in sphingosine-1 phosphate-induced EC barrier enhancement. Phosphorylation of a conserved threonine residue in the COOH-terminus of ERM proteins causes conformational changes in ERM to unmask binding sites and is considered a hallmark of ERM activation. In the present study we test the hypothesis that ERM proteins are phosphorylated on this critical threonine residue by thrombin-induced signaling events and explore the role of the ERM family in modulating thrombin-induced cytoskeletal rearrangement and EC barrier function. Thrombin promotes ERM phosphorylation at this threonine residue (ezrin Thr567, radixin Thr564, moesin Thr558) in a PKC-dependent fashion and induces translocation of phosphorylated ERM to the EC periphery. Thrombin-induced ERM threonine phosphorylation is likely synergistically mediated by protease-activated receptors PAR1 and PAR2. Using the siRNA approach, depletion of either moesin alone or of all three ERM proteins significantly attenuates thrombin-induced increase in EC barrier permeability (transendothelial electrical resistance), cytoskeletal rearrangements, paracellular gap formation, and accumulation of phospho-myosin light chain. In contrast, radixin depletion exerts opposing effects on these indexes. These data suggest that ERM proteins play important differential roles in the thrombin-induced modulation of EC permeability, with moesin promoting barrier dysfunction and radixin opposing it.

[Review of 40 years AO/ASIF. The development of the Veterinary Surgical Working Group for Osteosynthesis Questions(AO) in Veterinary Medicine (AOVET) and a systematic operative fracture treatment in animals]

With respect to the founding of the AOVET in 1969, the development of the systematic osteosynthesis in large and small animals is reviewed. With the introduction of the stable OS techniques corresponding to the principles and operative techniques developed by the organization of ASIF/AO (hum), the systematic operative fracture treatment in animals expanded remarkably. The application of the "absolutely" stable compression osteosynthesis was the basis for the successful fracture treatment in large animals. The systematic osteosynthesis in small animals was realized through the generation of a multitude of stabilization techniques for the different fracture types in the various anatomical areas and for special orthopaedic interventions. This was achieved through a specifically developed implant- instrument system and corresponding operation methods. This development was supported by instruction courses, published manuals and visiting fellowships. The extensive collaboration in research and development led to an increasing understanding of the diverse bone healing processes. The AOVET enjoyed a progressing integration into the AO/ASIF (hum) organization.