The PI3K–NF-κB signal transduction pathway is involved in mediating the anti-inflammatory effect of IB-MECA in adjuvant-induced arthritis

The anti-inflammatory effect of adenosine was previously found to be mediated via activation of the A(3 )adenosine receptor (A(3)AR). The aim of the present study was to decipher the molecular mechanism involved with the inhibitory effect of IB-MECA, an A(3)AR agonist, on adjuvant-induced arthritis. The adjuvant-induced arthritis rats responded to IB-MECA treatment with a decrease in the clinical score and the pathological score of the disease. The response to IB-MECA was neutralized by the antagonist MRS 1220, confirming that the efficacy of the synthetic agonist was A(3)AR mediated. The A(3)AR protein expression level was highly expressed in the synovia, in the peripheral blood mononuclear cells and in the drain lymph node (DLN) tissues of adjuvant-induced arthritis rats in comparison with naïve animals. Downregulation of A(3)AR expression was noted upon treatment with IB-MECA. Analysis of synovia and DLN protein extracts revealed a decreased expression level of PI3K, PKB/Akt, IKK, NF-κB and tumor necrosis factor alpha, known to affect survival and apoptosis of inflammatory cells, whereas the caspase-3 level was upregulated. Taken together, high A(3)AR expression is found in the synovia, in the immune cells in the DLN and in peripheral blood mononuclear cells. IB-MECA, an orally bioavailable molecule, activates the A(3)AR, inducing receptor downregulation and the initiation of a molecular mechanism that involves de-regulation of the PI3K–NF-κB signaling pathway. As a result, a potent anti-inflammatory effect manifested in the improvement of the disease clinical score and pathological score occurs. The finding that the A(3)AR expression level in the peripheral blood mononuclear cells and in the DLN reflects the receptor status in the remote inflammatory site suggests use of the A(3)AR as a follow-up biomarker

Transversality of Electromagnetic Waves in the Calculus-Based Introductory Physics Course

Introductory calculus-based physics textbooks state that electromagnetic waves are transverse and list many of their properties, but most such textbooks do not bring forth arguments why this is so. Both physical and theoretical arguments are at a level appropriate for students of courses based on such books, and could be readily used by instructors of such courses. Here, we discuss two physical arguments (based on polarization experiments and on lack of monopole electromagnetic radiation), and the full argument for the transversality of (plane) electromagnetic waves based on the integral Maxwell equations. We also show, at a level appropriate for the introductory course, why the electric and magnetic fields in a wave are in phase and the relation of their magnitudes.Comment: 10 pages, 6 figure

Context matters: Student-perceived binge drinking norms at faculty-level relate to binge drinking behavior in higher education

Background: Binge drinking in higher education is an important problem. To target binge drinking in students it is necessary to study the social context of students. Faculties (i.e., colleges or schools in Northern American education) are social contexts in which students behave, but little is known about how the faculty structure relates to monthly binge drinking. This study investigates the relationship with student-perceived binge drinking norms at faculty-level in addition to known personal determinants. Methods: Data were collected in 7181 students within 22 faculty-level units, using an anonymous online survey. Multilevel analyses were used to investigate the relationship of both individual-level determinants (e.g., perceived norms, social drinking motives) and student-perceived binge drinking norms at faculty-level on monthly binge drinking. Results: Two-third (62.2%) of the sample were female and the mean age was 21.06 (SD = 2.85) years. In males, significant faculty-level variance in monthly binge drinking was found. At faculty-level, only same-sex student-perceived binge drinking norms showed a positive relationship (OR = 2.581; 95%CI = [1.023,6.509]). At individual level, both opposite- and same-sex perceived binge drinking norms, and social drinking motives positively related to monthly binge drinking. In females, no significant faculty-level variance was found. Only individual-level determinants positively related to monthly binge drinking. No cross-level interactions were found. Conclusion: Besides individual determinants, especially in men, faculties are relevant environmental structures and networks to take into account when targeting binge drinking in higher education

Biocompatibility of a Marine Collagen-Based Scaffold In Vitro and In Vivo

Scaffold material is essential in providing mechanical support to tissue, allowing stem cells to improve their function in the healing and repair of trauma sites and tissue regeneration. The scaffold aids cell organization in the damaged tissue. It serves and allows bio mimicking the mechanical and biological properties of the target tissue and facilitates cell proliferation and differentiation at the regeneration site. In this study, the developed and assayed bio-composite made of unique collagen fibers and alginate hydrogel supports the function of cells around the implanted material. We used an in vivo rat model to study the scaffold effects when transplanted subcutaneously and as an augment for tendon repair. Animals’ well-being was measured by their weight and daily activity post scaffold transplantation during their recovery. At the end of the experiment, the bio-composite was histologically examined, and the surrounding tissues around the implant were evaluated for inflammation reaction and scarring tissue. In the histology, the formation of granulation tissue and fibroblasts that were part of the inclusion process of the implanted material were noted. At the transplanted sites, inflammatory cells, such as plasma cells, macrophages, and giant cells, were also observed as expected at this time point post transplantation. This study demonstrated not only the collagen-alginate device biocompatibility, with no cytotoxic effects on the analyzed rats, but also that the 3D structure enables cell migration and new blood vessel formation needed for tissue repair. Overall, the results of the current study proved for the first time that the implantable scaffold for long-term confirms the well-being of these rats and is correspondence to biocompatibility ISO standards and can be further developed for medical devices application