Objective To investigate the effects and mechanism of remifentanil on renal ischemia/reperfusion(IR) injury via mediating Fas apoptosis signal pathway in rats.Methods Sprague-Dawley rats were divided into 3 groups (n =20 each) by using the random number table method:sham operation group (S group),IR control group (IR group),experimental group (Rgroup).The renal IR model was prepared by clamping the bilateral renal arteries for 45 min followedby reperfusion in IR group and R group.In R group,remifentanil was infused at 1.0μg·kg-1 ·min-1 via the tail vein starting from 15 min before ischemia until 30 min of reperfusion.In S group and IR group,the same volume of physiological saline was given.At 15 min before ischemia and at 3 h,12 h,24 h of reperfusion,the renal tissue samples were obtained for detecting the apoptosis rate by flow cytometry,determining the level of Fas mRNA expression by RT-PCR,the level of caspase-8 and caspase-3 activation by Western blotting,and scoring the number of kidney tubules injury by Paller'method.Results In IR group,the renal tubular injury score,the apoptosis rate,the expression of Fas mRNA and the activation of caspase-3 in renal tissue increased at 3 h after reperfusion,and those continued to increase at 12 h after reperfusion and reached the peak at 24 h after reperfusion (P＜0.01),and the activity of caspase-8 increased at 3 b,reached the peak at 12 h after reperfusion and decreased at 24 h after reperfusion (P＜0.01).As compared with S group,the renal tubular injury score,apoptosis rate,the expression of Fas mRNA and the activation of caspase-3 at 3 h,12 h and 24 h of reperfusion and the activation of caspase-8 at 12 h,24 h of reperfusion were all increased in IR group and R group (P＜0.05 or 0.01).As compared with IR group,the renal tubular injury score,apoptosis rate,the expression of Fas mRNA and the activation of caspase-8 and caspase-3 at 3 h,12 h and 24 h of reperfusion were decreased in R group (P＜0.05 or 0.01).Conclusion Remifentanil inhibits cell apoptosis and alleviates renal IR damage by reducing the expression of Fas receptor and the activation of caspase-8 and caspase-3,and regulating the apoptotic signal pathway of Fas.

Objective:To investigate and summarize the chest CT imaging features of patients with novel coronavirus pneumonia (COVID-19), bacterial pneumonia and other viral pneumonia.Methods:Chest CT data of 102 patients with pulmonary infection due to different etiologies were retrospectively analyzed, including 36 patients with COVID-19 admitted to Hainan Provincial People's Hospital and the Second Affiliated Hospital of Hainan Medical University from December 2019 to March 2020, 16 patients with other viral pneumonia admitted to Hainan Provincial People's Hospital from January 2018 to February 2020, and 50 patients with bacterial pneumonia admitted to Haikou Affiliated Hospital of Central South University Xiangya School of Medicine from April 2018 to May 2020. Two senior radiologists and two senior intensive care physicians were participated to evaluated the extent of lesions involvement and imaging features of the first chest CT after the onset of the disease.Results:Bilateral pulmonary lesions were more common in patients with COVID-19 and other viral pneumonia, and the incidence was significantly higher than that of bacterial pneumonia (91.6%, 75.0% vs. 26.0%, P < 0.05). Compared with other viral pneumonia and COVID-19, bacterial pneumonia was mainly characterized by single-lung and multi-lobed lesion (62.0% vs. 18.8%, 5.6%, P < 0.05), accompanied by pleural effusion and lymph node enlargement. The proportion of ground-glass opacity in the lung tissues of patients with COVID-19 was 97.2%, that of patients with other viral pneumonia was 56.2%, and that of patients with bacterial pneumonia was only 2.0% ( P < 0.05). The incidence rate of lung tissue consolidation (25.0%, 12.5%), air bronchial sign (13.9%, 6.2%) and pleural effusion (16.7%, 37.5%) in patients with COVID-19 and other viral pneumonia were significantly lower than those in patients with bacterial pneumonia (62.0%, 32.0%, 60.0%, all P < 0.05), paving stone sign (22.2%, 37.5%), fine mesh sign (38.9%, 31.2%), halo sign(11.1%, 25.0%), ground-glass opacity with interlobular septal thickening (30.6%, 37.5%), bilateral patchy pattern/rope shadow (80.6%, 50.0%) etc. were significantly higher than those of bacterial pneumonia (2.0%, 4.0%, 2.0%, 0%, 22.0%, all P < 0.05). The incidence of local patchy shadow in patients with COVID-19 was only 8.3%, significantly lower than that in patients with other viral pneumonia and bacterial pneumonia (8.3% vs. 68.8%, 50.0%, P < 0.05). There was no significant difference in the incidence of peripheral vascular shadow thickening in patients with COVID-19, other viral pneumonia and bacterial pneumonia (27.8%, 12.5%, 30.0%, P > 0.05). Conclusions:The probability of ground-glass opacity, paving stone and grid shadow in chest CT of patients with COVID-19 was significantly higher than those of bacterial pneumonia, and it was more common in the lower lungs and lateral dorsal segment. In other patients with viral pneumonia, ground-glass opacity was distributed in both upper and lower lungs. Bacterial pneumonia is usually characterized by single lung consolidation, distributed in lobules or large lobes and accompanied by pleural effusion.