The Behaviour of the Red Blood-corpuscles when shaken with Indifferent Substances

miR-146a regulates mechanotransduction and pressure-induced inflammation in small airway epithelium

Mechanical ventilation generates biophysical forces, including high transmural pressures, which exacerbate lung inflammation. This study sought to determine whether microRNAs (miRNAs) respond to this mechanical force and play a role in regulating mechanically induced inflammation. Primary human small airway epithelial cells (HSAEpCs) were exposed to 12 h of oscillatory pressure and/or the proinflammatory cytokine TNF-α. Experiments were also conducted after manipulating miRNA expression and silencing the transcription factor NF-κB or toll-like receptor proteins IRAK1 and TRAF6. NF-κB activation, IL-6/IL-8/IL-1β cytokine secretion, miRNA expression, and IRAK1/TRAF6 protein levels were monitored. A total of 12 h of oscillatory pressure and TNF-α resulted in a 5- to 7-fold increase in IL-6/IL-8 cytokine secretion, and oscillatory pressure also resulted in a time-dependent increase in IL-6/IL-8/IL-1β cytokine secretion. Pressure and TNF-α also resulted in distinct patterns of miRNA expression, with miR-146a being the most deregulated miRNA. Manipulating miR-146a expression altered pressure-induced cytokine secretion. Silencing of IRAK1 or TRAF6, confirmed targets of miR-146a, resulted in a 3-fold decrease in pressure-induced cytokine secretion. Cotransfection experiments demonstrate that miR-146a's regulation of pressure-induced cytokine secretion depends on its targeting of both IRAK1 and TRAF6. MiR-146a is a mechanosensitive miRNA that is rapidly up-regulated by oscillatory pressure and plays an important role in regulating mechanically induced inflammation in lung epithelia.

The destruction of rennin by agitation: A case of catalysis at an air-liquid interface

In a course of a series of investigations on the condition of maximum toxin formation by C. Diphtheria , undertaken by one of us (C. G. L. W.) (3), the question of “ripening” and of the deterioration of toxin in transport appeared to be colloidal phenomena in which interfacial action play a part. It was also noted that in the preparation of high dilutions of toxin for the Schick test great care is necessary when mixing the strong toxin with a diluent in order that no air bubbles passed through the solution. If this precaution was not taken the test fluid deteriorated in strength and led to untrustworthy results. Apart from the practical importance of the loss of strength of toxins, the process by which destruction was brought about was by no means clear, and it was considered of interest to investigate the phenomenon in more detail.

Metabolic dependence of the critical hemolytic volume of human erythrocytes: relationship to osmotic fragility and autohemolysis in hereditary spherocytosis and normal red cells

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