Objective To investigate the safety of left atrial appendage occlusion by silk thread ligation during open heart op‐eration in patients with rheumatic atrial fibrillation ,and to evaluate its effectiveness for prevention of cerebral embolism .Methods From April 2012 to March 2014 ,129 patients with rheumatic atrial fibrillation were undergone mitral valve replacement and left at‐rial appendage occlusion by ligation using two silk threads from the outside of the heart (ligation group) .The indexes related to the operation ,postoperative complications incidence ,and cerebral embolism incidence during the follow‐up period of ligation group were compared with the indexes of another 129 patients without ligation of left atrial appendage over the same period (control group) . Results The operation time ,the cardiopulmonary bypass time ,the clamp time ,the intensive care unit stay time ,the postoperative hospitalization time in ligation group were (235 ± 50)min ,(88 ± 24)min ,(57 ± 16)min ,(26 .5 ± 9 .3)h and (12 .4 ± 7 .5)d respective‐ly ,and significant difference was not found compared with control group (P>0 .05) .The thoracotomy for hemostasis(1 cases) ,low cardiac output syndrome(2 cases) ,acute renal failure(2 cases) ,pulmonary infection(3 cases) ,sternal wound dehiscence(2 cases) and other complications in ligation group had no significant difference ,compared with control group(P>0 .05);2 cases died in liga‐tion group ,3 patients died in control group ,the differences had no statistical significance(P>0 .05) .No cerebral embolism occurred in ligation group with 127 patients following‐up (23 .6 ± 11 .3) months ,but 5 patients suffered from cerebral embolism in control group with 126 patients following‐up (22 .9 ± 12 .1) months ,the difference had statistical significance(P<0 .05) .Conclusion Left atrial appendage occlusion by silk thread ligation during open heart operation in patients with rheumatic atrial fibrillation is simple and safe ,can reduce cerebral embolism incidence .

Objective:To investigate specificity of neurovascular compression in patients with primary trigeminal neuralgia (PTN) by three-dimension reconstruction and computational fluid dynamics.Methods:Clinical characteristics and preoperative magnetic resonance imaging (MRI) data of 20 patients with both PTN and single artery compression (PTN group) and 10 patients without PTN but having neurovascular contact in MRI images (control group) in the Second Affiliated Hospital of Zhengzhou University from January 2018 to December 2019 were collected and analyzed. After three-dimension reconstruction of the MRI images, curvature of the arterial loop, angle between the plane of arterial loop and the trigeminal nerve and location of the compression were observed. Then bidirectional structure-fluid coupling based on the optimized stereolithography models of arterial loop and nerve were processed by ANSYS 19.2 software. In the location of the compression of contact, equivalent stress (ES) of arterial loop on the nerve, shearing stress (SS) of the blood flow and local deformation of the nerve were iteratively computed. All parameters were analyzed and compared between the PTN group and the control group, and the correlation analysis was proceeded between the anatomical parameters and hemodynamical parameters.Results:The curvature of arterial loop [0.21(0.12) mm -1vs 0.13(0.07) mm -1, U=34.00, P<0.05], the angle between vascular loop and nerve [69.70(30.67)° vs 43.40(37.21)°, U=38.00, P<0.05] in the PTN group were significantly greater than those in the control group, and the location of compression was significantly closer to the root of nerve in the PTN group [PTN group: (4.23±1.29) mm vs control group: (5.54±1.85) mm, t=-2.26, P<0.05]. The average SS [15 952.48(5 365.56) Pa vs 12 501.97(6 355.26) Pa, U=53.00, P<0.05], ES [24 965.65(7 693.22) Pa vs 14 992.99(9 824.08) Pa, U=32.00, P<0.05] in the PTN group were significantly greater than those in the control group. The curvature of arterial loop was positively correlated with the SS ( r=0.931, P<0.05) and ES ( r=0.962, P<0.05), and the latter two ( r=0.787, P<0.05; r=0.853, P<0.05) were positively correlated with the local neural deformation. Conclusions:In patients with PTN, offending artery compresses the root of nerve by greater arterial curvature and angle between the arterial loop and nerve. These anatomical differences will cause significantly greater SS, ES and local neural deformation.

Objective: To investigate the effect of NACHT-LRR-PYD- containing proteins 3 (NLRP3) mediated pyroptosis in myocardial cells undergoing hypoxia/deoxygenation (H/R) injury. Methods: In order to observe whether H/R-treatment could cause pyroptosis, H9c2 cells were divided into 2 groups randomly using the lottery method: control group(without H/R-treatment) and H/R group (in which the H9c2 cells were underwent H/R-treatment). In order to clarify the role of pyroptosis in H/R-injury, H9c2 cells were divided into 4 groups randomly using the lottery method: control group(in which the H9c2 cells were cultivated with normal medium); YVAD group(in which the H9c2 cells were pretreated with z-Val-Ala-Asp(Ome)-fluoromethylketone (Z-YVAD-FMK) 20 μm for 4 hours, then replaced with normal medium); H/R group(H9c2 cells underwent H/R-treatment); YVAD+H/R group (in which the H9c2 cells were pretreated with 20 μm Z-YVAD-FMK for 4 hours before H/R-treatment). To determine whether H/R-induced cell pyroptosis is associated with NLRP3, H9c2 cells were divided into 4 groups randomly using the lottery method: control group (in which cells were transfected with a control nonspecific siRNA); si-NLRP3 group (in which cells were transfected with NLRP3-targeting siRNA); H/R group(in which cells were transfected with a control nonspecific siRNA before H/R-treatment); si-NLRP3+H/R group(in which the H9c2 cells were transfected with NLRP3-targeting siRNA before H/R-treatment). Pore formation on cell membrane was detected by propidium iodide (PI) staining. Cell viability was detected by CCK8 reagent. The protein expression of Caspase-1, interleukin-1β (IL-1β) and NLRP3 was detected by Western blot. Results: (1) The positive rate of PI staining ((26.46±5.15)% vs. (1.69±0.73)%,P<0.01), expression of NLRP3 (0.57±0.16 vs. 0.23±0.06,P<0.01), expression of Caspase-1 (1.07±0.13 vs. 0.37±0.08,P<0.01), and expression of IL-1β (0.38±0.08 vs. 0.16±0.05,P<0.01) were significantly higher in H/R group than in control group. (2)The cell vitality was significantly higher in YVAD+H/R group than in H/R group ((87.31±9.05)% vs. (73.30±7.19)%, P<0.05).The positive rate of PI staining was significantly decreased in YVAD+H/R group than in H/R group ((18.12±4.36)% vs. (26.45±4.60)%, P<0.05). The expression of Caspase-1 (0.72±0.12 vs. 1.07±0.15, P<0.05) and IL-1β(0.29±0.07 vs. 0.39±0.06, P<0.05) were significantly lower in YVAD+H/R group than in H/R group. (3) The cell vitality was significantly increased in si-NLRP3+H/R group than in H/R group ((85.46±7.71)% vs. (72.41±5.53)%, P<0.05). The positive rate of PI staining was significantly lower in si-NLRP3+H/R group than in H/R group ((18.22±4.20)% vs. (26.73±3.26)%, P<0.05). The expression of Caspase-1(0.87±0.07 vs. 1.15±0.15, P<0.05) and IL-1β(0.41±0.07 vs. 0.58±0.10, P<0.05) were significantly decreased in si-NLRP3+H/R group than in H/R group. Conclusion NLRP3 mediated pyroptosis is involved in H/R injury of myocardial cells.