Classically, it is known that red blood cell (RBC) deformability is determined by the geometric and material properties of these cells. Experimental evidence accumulated during the last decade has introduced the concept of active regulation of RBC deformability. This regulation is mainly related to altered associations between membrane skeletal proteins and integral proteins, with the latter serving to anchor the skeleton to the lipid matrix. It has been hypothesized that shear stress induces alterations of RBC deformability: the current study investigated the dynamics of the transient improvement in deformability induced by shear stress at physiologically-relevant levels. RBC were exposed to various levels of shear stress (SS) in a Couette type shearing system that is part of an ektacytometer, thus permitting the changes in RBC deformability during the application of SS to be monitored. Initial studies showed that there is an increase in deformability of the RBC subjected to SS in the range of 5-20 Pa, with kinetics characterized by time constants of a few seconds. Such improvement in deformability, expressed by an elongation index (EI), was faster with higher levels of SS and hence yielded shorter time constants: absolute values of EI increased by 3-8% of the starting level. Upon the removal of the shear stress, this response by RBC was reversible with a slower time course compared to the increase in EI during application of SS. Increased calcium concentration in the RBC suspending medium prevented the improvement of deformability. It is suggested that the improvement of RBC deformability by shear forces may have significant effects on blood flow dynamics, at least in tissues supplied by blood vessels with impaired vasomotor reserve, and may therefore serve as a compensating mechanism for the maintenance of adequate microcirculatory perfusion.

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Our results indicate that the weekly training hours and total years of training with American football increase posterior channel BPPV frequency.

Background Intranasal phototherapy offers an alternative treatment method for patients with allergic rhinitis who cannot benefit from intranasal corticosteroids and oral antihistamines. Different wavelengths have been tried with promising results. Objective In this present study, we aimed to investigate the effects of visible light-infrared light phototherapy on clinical improvements together with its cytologic effects in patients with allergic rhinitis. Methods Patients with confirmed allergic rhinitis were given a 4-week course of intranasal phototherapy treatment. Weekly symptom questionnaires were applied to monitor clinical effects. Nasal lavage specimens were obtained before the start and at the completion of the 4-week therapy. Fluorescence-activated cell sorting analyses of CD16+, CD24+, and CD 45+ cells were performed. Statistical analyses are performed of weekly changes in symptoms and cell counts. Results CD45+CD16highCD24+ neutrophil count in nasal lavages decreased significantly whereas CD45+CD16dim/−CD24+ eosinophil counts significantly increased and CD45+ granulocyte counts remained unchanged. Symptom scores including nasal itching, nasal discharge, nasal obstruction, sneezing, eye itching, throat itching, and ear itching all statistically decreased compared to baseline at the end of 4 weeks. Conclusion Four-week course of intranasal phototherapy with visible and infrared light leads to clinical improvement in allergic rhinitis patients.

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