Shear stress mediates exocytosis of functional TRPV4 channels in endothelial cells

Mechanosensitive ion channels are implicated in the biology of touch, pain, hearing and vascular reactivity; however, the identity of these ion channels and the molecular basis of their activation is poorly understood. We previously found that transient receptor potential vanilloid 4 (TRPV4) is a receptor operated ion channel that is sensitised and activated by mechanical stress. Here, we investigated the effects of mechanical stimulation on TRPV4 localisation and activation in native and recombinant TRPV4-expressing cells. We used a combination of total internal reflection fluorescence microscopy, cell surface biotinylation assay and Ca<sup>2+</sup> imaging with laser scanning confocal microscope to show that TRPV4 is expressed in primary vascular endothelial cells and that shear stress sensitises the response of TRPV4 to its agonist, GSK1016790A. The sensitisation was attributed to the recruitment of intracellular pools of TRPV4 to the plasma membrane, through the clathrin and dynamin-mediated exocytosis. The translocation was dependent on ILK/Akt signalling pathway, release of Ca<sup>2+</sup> from intracellular stores and we demonstrated that shear stress stimulated phosphorylation of TRPV4 at tyrosine Y110. Our findings implicate calcium-sensitive TRPV4 translocation in the regulation of endothelial responses to mechanical stimulation

Measurement of exercise cardiac output by thoracic impedance in healthy children

In order to understand factors influencing fever/malaria management practices among community-based individuals, the study evaluated psychosocial, socio-demographic and environmental determinants of prompt and adequate healthcare-seeking behaviours. A quantitative household (HH) survey was conducted from December 2014 to February 2015 in Ruhuha sector, Bugesera district in the Eastern province of Rwanda. HHs that reported having had at least one member who experienced a fever and/or malaria episode in the previous 3 months prior to the study were included in the analysis. Healthcare-seeking behaviours associated with the last episode of illness were analysed. Socio-demographic, health facility access, long-lasting insecticidal-treated nets (LLINs), data on malaria knowledge, data and theory of planned behaviour (TPB) related variables (attitudes, subjective norms, perceived behavioural control) with regard to fever/malaria healthcare seeking, were collected. The primary outcome was prompt and adequate care defined as: (1) seeking advice or treatment at a health facility (health centre or hospital) or from a community health worker (CHW); (2) advice or treatment seeking within same/next day of symptoms onset; (3) received a laboratory diagnosis; (4) received advice or treatment; and, (5) reported completing the prescribed dose of medication. Determinants of prompt and adequate care among presumed malaria cases were evaluated using a logistic regression analysis. Overall, 302 (21 %) of the 1410 interviewed HHs reported at least one member as having experienced a fever or malaria within the 3 months prior to the survey. The number of HHs (where at least one member reported fever/malaria) that reported seeking advice or treatment at a health facility (health centre or hospital) or from a CHW was 249 (82.4 %). Of those who sought advice or treatment, 87.3 % had done so on same/next day of symptoms developing, 82.8 % received a laboratory diagnosis, and more than 90 % who received treatment reported completing the prescribed dosage. Prompt and adequate care was reported from 162 of the 302 HHs (53.6 %) that experienced fever or malaria for one or more HH members. Bivariate analyses showed that head of household (HoH)-related characteristics including reported knowledge of three or more malaria symptoms, having health insurance, being able to pay for medical services, use of LLINs the night before the survey, having a positive attitude, perceiving social support, as well as a high-perceived behavioural control with regard to healthcare seeking, were all significantly associated with prompt and adequate care. In the final logistic regression model, a high-perceived behavioural control (odds ratio (OR) 5.068, p = 0.042), having a health insurance (OR 2.410, p = 0.044) and having knowledge of malaria symptoms (OR 1.654, p = 0.049) significantly predicted prompt and adequate care. To promote prompt and adequate care seeking for malaria in the area, particular emphasis should be placed on community-focused strategies that promote early malaria symptom recognition, increased health insurance coverage and enhanced perceived behavioural control with regard to healthcare-seekin