High-yield isolation of extracellular vesicles using aqueous two-phase system

Extracellular vesicles (EVs) such as exosomes and microvesicles released from cells are potential biomarkers for blood-based diagnostic applications. To exploit EVs as diagnostic biomarkers, an effective pre-analytical process is necessary. However, recent studies performed with blood-borne EVs have been hindered by the lack of effective purification strategies. In this study, an efficient EV isolation method was developed by using polyethylene glycol/dextran aqueous two phase system (ATPS). This method provides high EV recovery efficiency (similar to 70%) in a short time (similar to 15 min). Consequently, it can significantly increase the diagnostic applicability of EVs.113219Ysciescopu

Mycobacteria Attenuate Nociceptive Responses by Formyl Peptide Receptor Triggered Opioid Peptide Release from Neutrophils

In inflammation, pain is regulated by a balance of pro- and analgesic mediators. Analgesic mediators include opioid peptides which are secreted by neutrophils at the site of inflammation, leading to activation of opioid receptors on peripheral sensory neurons. In humans, local opioids and opioid peptides significantly downregulate postoperative as well as arthritic pain. In rats, inflammatory pain is induced by intraplantar injection of heat inactivated Mycobacterium butyricum, a component of complete Freund's adjuvant. We hypothesized that mycobacterially derived formyl peptide receptor (FPR) and/or toll like receptor (TLR) agonists could activate neutrophils, leading to opioid peptide release and inhibition of inflammatory pain. In complete Freund's adjuvant-induced inflammation, thermal and mechanical nociceptive thresholds of the paw were quantified (Hargreaves and Randall-Selitto methods, respectively). Withdrawal time to heat was decreased following systemic neutrophil depletion as well as local injection of opioid receptor antagonists or anti-opioid peptide (i.e. Met-enkephalin, β-endorphin) antibodies indicating an increase in pain. In vitro, opioid peptide release from human and rat neutrophils was measured by radioimmunoassay. Met-enkephalin release was triggered by Mycobacterium butyricum and formyl peptides but not by TLR-2 or TLR-4 agonists. Mycobacterium butyricum induced a rise in intracellular calcium as determined by FURA loading and calcium imaging. Opioid peptide release was blocked by intracellular calcium chelation as well as phosphoinositol-3-kinase inhibition. The FPR antagonists Boc-FLFLF and cyclosporine H reduced opioid peptide release in vitro and increased inflammatory pain in vivo while TLR 2/4 did not appear to be involved. In summary, mycobacteria activate FPR on neutrophils, resulting in tonic secretion of opioid peptides from neutrophils and in a decrease in inflammatory pain. Future therapeutic strategies may aim at selective FPR agonists to boost endogenous analgesia

Complex Dynamics of Landslides with Time Delay Under External Seismic Triggering Effect

In present paper, model of infinite creeping slope with Dieterich-Ruina rate-and state-dependent friction law is analyzed using methods of nonlinear dynamics. The model is examined under the variation of two parameters: time delay t(d) and initial shear stress s(0). Time delay describes the memory effect of the sliding surface and it is generally considered as a function of history of sliding. Initial stress parameter is periodically perturbed, corresponding to long duration shear seismic wave, or it could be generated by non-natural sources such as traffic vibrations. The co-action of the observed parameters is estimated for two different regimes of sliding, namely beta lt 1 and beta > 1, where beta denotes the ratio of long-term to short-term (immediate) stress change. The results of the analysis indicate that the most complex dynamics occurs for beta lt 1, when a possible Ruelle-Takens-Newhouse route to chaos is observed, with a transition from equilibrium state, through periodic and quasiperiodic motion to deterministic chaos. For beta > 1, system exhibits chaotic dynamics for t(d) = 0.1 and for delta(s) lt = 0.18. These results correspond well with the previous experimental observations on clay and siltstone with low clay fraction, indicating that the motion along the sliding surface is velocity-strengthening (beta lt 1)