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Objective Our previous retrospective study demonstrated that perioperative dexmedetomidine (Dex) administration was associated with low systemic inflammatory response syndrome (SIRS) incidence. The present study was designed to investigate whether perioperative administration of Dex decreases the incidence of postpercutaneous nephrolithotomy lithotripsy (PCNL) SIRS in patients who undergo PCNL. Design A randomised controlled trial was designed. Participants A total of 190 patients were randomly assigned to receive Dex (DEX group, n=95) or saline control (CON group, n=95) and completed the study. In the DEX group, Dex was loaded (1 µg/kg) before anaesthesia induction and was infused (0.5 µg/kg/h) during surgery. Outcomes The incidences of postoperative SIRS were recorded. Serum interleukin-6 (IL-6) and tumour necrosis factor α(TNF-α) were measured. Results The incidence rates of SIRS were significantly lower in the DEX group than in the CON group (35.8% vs 50.5%, p=0.04). No patients developed sepsis in either group. These results might be attributed to inhibition of inflammatory responses and the resulting lower serum levels of IL-6 and TNF-α, caused by Dex administration. However, compared with the CON group, the lower incidence rate of SIRS in the DEX group did not result in better outcomes, such as shorter postoperative hospitalisation stays and lower costs. Conclusion The present study showed that Dex administration during PCNL might be beneficial for decreasing the incidence of SIRS through inhibiting the release of inflammatory mediators, but not clinical consequences such as postoperative hospitalisation duration and costs. Further effects of Dex administration on SIRS in patients who are scheduled for PCNL should be explored in future studies. Trial registration number ChiCTR-ICR-15006167. [ABSTRACT FROM AUTHOR]

Tryptase exacerbates intestinal ischemia-reperfusion injury, however, the direct role of tryptase in intestinal mucosal injury and the underlying mechanism remains largely unknown. Protease-activated receptor 2 (PAR-2), commonly activated by tryptase, interacts with various adaptor proteins, including β-arrestin-2. The present study aimed to determine whether tryptase is capable of inducing intestinal mucosal cell injury via PAR-2 activation and to define the role of β-arrestin-2 in the process of injury. The IEC-6 rat intestinal epithelial cell line was challenged by tryptase stimulation. Cell viability, lactate dehydrogenase (LDH) activity and apoptosis were analyzed to determine the severity of cell injury. Injury was also evaluated following treatments with specific PAR-2 and extracellular signal-related kinases (ERK) inhibitors, and knockdown of β-arrestin-2. PAR-2, ERK and β-arrestin-2 protein expression levels were evaluated. Tryptase treatment (100 and 1,000 ng/ml) resulted in IEC-6 cell injury, as demonstrated by significant reductions in cell viability, accompanied by concomitant increases in LDH activity and levels of cleaved caspase-3 protein expression. Furthermore, tryptase treatment led to a marked increase in PAR-2 and phosphorylated-ERK expression, and exposure to specific PAR-2 and ERK inhibitors eliminated the changes induced by tryptase. Knockdown of β-arrestin-2 blocked tryptase-mediated cell injury, whereas tryptase exerted no influence on β-arrestin-2 expression in IEC-6 cells. These data indicate that tryptase may directly damage IEC-6 cells via PAR-2 and the downstream activation of ERK, and demonstrate that the signaling pathway requires β-arrestin-2. [ABSTRACT FROM AUTHOR]

The study aimed to investigate whether sevoflurane preconditioning can protect against small intestinal ischemia reperfusion (IIR) injury and to explore whether mast cell (MC) is involved in the protections provided by sevoflurane preconditioning. Sprague-Dawley rats exposed to sevoflurane or treated with MC stabilizer cromolyn sodium (CS) were subjected to 75-minute superior mesenteric artery occlusion followed by 2-hour reperfusion in the presence or absence of MC degranulator compound 48/80 (CP). Small intestinal ischemia reperfusion resulted in severe intestinal injury as demonstrated by significant elevations in intestinal injury scores and p47phox and gp91phox, ICAM-1 protein expressions and malondialdehyde and IL-6 contents, and MPO activities as well as significant reductions in SOD activities, accompanied with concomitant increases in mast cell degranulation evidenced by significant increases in MC counts, tryptase expression, and β-hexosaminidase concentrations, and those alterations were further upregulated in the presence of CP. Sevoflurane preconditioning dramatically attenuated the previous IIR-induced alterations except MC counts, tryptase, and β-hexosaminidase which were significantly reduced by CS treatment. Furthermore, CP exacerbated IIR injury was abrogated by CS but not by sevoflurane preconditioning. The data collectively indicate that sevoflurane preconditioning confers protections against IIR injury, and MC is not involved in the protective process. [ABSTRACT FROM AUTHOR]

Brahma-related gene 1 (Brg1) is a key gene in inducing the expression of important endogenous antioxidant enzymes, including heme oxygenase-1 (HO-1) which is central to cardioprotection, while cardiac HO-1 expression is reduced in diabetes. It is unknown whether or not cardiac Brg1 expression is reduced in diabetes. We hypothesize that cardiac Brg1 expression is reduced in diabetes which can be restored by antioxidant treatment with N-acetylcysteine (NAC). Control (C) and streptozotocin-induced diabetic (D) rats were treated with NAC in drinking water or placebo for 4 weeks. Plasma and cardiac free 15-F2t-isoprostane in diabetic rats were increased, accompanied with increased plasma levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin 6 (IL-6), while cardiac Brg1, p-STAT 3 and HO-1 protein expression levels were significantly decreased. Left ventricle weight/body weight ratio was higher, while the peak velocities of early (E) and late (A) flow ratio was lower in diabetic than in C rats. NAC normalized tissue and plasma levels of 15-F2t-isoprostane, significantly increased cardiac Brg1, HO-1 and p-STAT3 protein expression levels and reduced TNF-alpha and IL-6, resulting in improved cardiac function. In conclusion, myocardial Brg1 is reduced in diabetes and enhancement of cardiac Brg1 expression may represent a novel mechanism whereby NAC confers cardioprotection. [ABSTRACT FROM AUTHOR]