Objective To evaluate the diagnostic value of 64-row VCT coronary angiography(CTA) in diagnosing coronary artery disease.Methods 64-row VCT coronary angiography(CTA) and cathter coronary angiography(CAG) were performed in 173 patients with suspected coronary artery disease.All images were analysed at GE AW4.3 workstation,the constructed images included maximum intensity projection(MIP),mlti-planar reconstruction(MPR) and volume rendering(VR).The results were compared with that of CAG.Results 746 segments of coronary artery with diameter ＞1.5 mm were showed by CTA in 173 patients.The sensitivity,specificity,positive predictive value and negative predictive value of the CTA in detecting coronary arterial stenosis were 94.15%(193/203),95.90% and 89.77% and 97.90% respectively.Statistical analysis using a 2-related χ~2 test showed that there were no obvious differences in diagnosing coronary arterial stenosis between CTA and CAG(χ~2=1.58,P＞0.05) and in evaluating the stenosis degree of coronary artery(Kappa=0.890,P＜0.001).Conclusion 64-row VCT has important clinical value in screening coronary arterial disease and in following-up post operational effectiveness of coronary stent implantation and vascular bypass.

Objective:To investigate the role of melatonin in calcium overload-induced heart injury.Methods:Thirty-two rats were divided into 4 groups:a control group (Control),a melatonin control group (Mel),a calcium overload group (CaP),and a calcium overload plus melatonin group (Mel+CaP).Isolated Sprague Dawley male rat hearts underwent Langendorffperfusion.Left ventricular developed pressure (LVDP) was calculated to evaluate the myocardial performance.Triphenyltetrazolium chloride staining was used to measure the infarct size of myocardium.Lactate dehydrogenase (LDH) activity in the coronary flow was determined.The expressions of caspase-3 and cytochrome c were determined by Western blot.The pathological morphological changes in myocardial fiber were analyzed by HE staining.Results:Compared with the control group,calcium overload significantly induced an enlarged infarct size (P＜0.01),accompanied by the disordered arrangement of myocardial fiber,up-regulation of cytochrome c and caspase-3 (P＜0.01),and the increased activity of LDH (P＜0.01).T hese effects were significantly attenuated by 10 μmol/L melatonin (P＜0.01).Conclusion:Melatonin can alleviate calcium overload-induced heart injury.

Objective To evaluate the value of CT guided percutaneous lumbar diskectomy (CT PLD) at plateau area. Methods Sixty eight cases of lumbar disc herniation was reated with CT PLD. (1)Before operation, diseased intervertebral disc was scanned, cases were selected, and operation plan was plotted . (2)The best puncture arrangement was chosen on the current video CT picture by designing the puncture path, noting down the puncture parameter, and marking the puncture spot on patient′s body surface. (3)Puncture was performed according to fixed parameter. (4)Operation was performed after the puncture needle was put into the disc ascertained by scan.(5)CT scan was done again after operation to observe if the puncture path had bleeding and intervertebral disc recovery. Results After 3 to 18 months′ follow up, 28 cases were prominent effective and 36 cases effective. The lumbar disc backed 1 to 4 mm. The total effective rate was 94.12%. Conclusion CT PLD is an ideal therapeutic method for lumbar disc herniation at plateau area because it is safe and effective and with less complications.

Objective: To investigate risk perception, emergency preparedness and emergency literacy among medical students under COVID-19 epidemic. Methods: An online survey was conducted by using the self designed COVID-19 questionnaire on risk perception, emergency preparedness and emergency literacy from March 27 to March 30, 2020. The convenience sampling method was used to investigate 4 864 medical students from 2 colleges and technical secondary schools in Sichuan Province. Results: The scores of risk perception, emergency preparedness and emergency literacy associated with COVID-19 were(35.18±4.33)(28.30±4.16) and(25.23±2.97) respectively. Risk perception of medical students was positively correlated with emergency preparedness and emergency literacy(r=0.35, 0.40), emergency preparedness was positively correlated with emergency literacy(r=0.51)(P<0.05). Conclusion Considering interrelationships among risk perception, emergency preparedness and emergency literacy associated with COVID-19, medical students should be given targeted prevention and control training.

Objective:To investigate the role of Na+/Ca2+ exchanger (NCX) in myocardial ischemiareperfusion injury and the underlying mechanisms.Methods:Forty Sprague-Dawley rats were divided into 4 groups randomly:a control group,a KBR7943 group,an ischemia-reperfusion group (IR group),and an IR plus KB-R7943 group (KB-R7943+IR group).Isolated Sprague Dawley male rat hearts underwent Langendorffperfusion.The ratio of left ventricular developed pressure (LVDP),left ventricular end-diastolic pressure (LVEDP),the infarct size of myocardium,and the lactate dehydrogenase (LDH) activity in the coronary flow was determined.HE staining was used to assess the change of myocardial morphology.Western blot was used to determine the levels of cleaved caspase-3,cytochrome c and the phosphorylation of Ca2+/calmodulin-dependent protein kinase Ⅱ (CaMKⅡ) and the Thr17 site ofphospholamban.Results:Compared with the control group,IR group significantly induced an enlarged infarct size,reduction of the ratio of LVDP,up-regulation of cytochrome c,cleaved caspase-3,p-CaMKⅡ and p-phospholamban,and increased in the activity of LDH,the level of LVEDP (P＜0.01) and the disordered myocardial morphology.These effects were significantly attenuated in the presence of KB-R7943 treatment (10 μmol/L).Conclusion:NCX mediates myocardial ischemia-reperfusion-induced cell apoptosis and necrosis through activation of CaMKⅡ.

Objective:To investigate the combination of internal fixation for periprosthetic fractures of the proximal femur (PFFF) after hip arthroplasty.Methods:The data of 58 patients with periprosthetic fractures after hip arthroplasty from May 2008 to March 2022 were retrospectively analyzed, including 31 males and 27 females. The average age was 75.5±18.2 years (range, 35-95 years). There were 39 total hip arthroplasty and 19 hemiarthroplasty; 37 biological prosthesis and 21 cemented prosthesis. Intraoperative periprosthetic fractures occurred in 6 cases and 52 cases postoperatively. Unified classification system (UCS): UCS IV.3A1 type 2 cases, 3A2 type 1 case, 3B1.1 type 19 cases, 3B2.1 type 25 cases, 3B3 type 2 cases, 3C type 9 cases. Fracture site: 3 cases in zone A (greater trochanter), 46 cases in zone B (around the femoral stem), and 9 cases in zone C (distal to the tip of the femoral stem. Internal fixation is composed of primary and secondary fixation, the main fixation method was the cerclage of steel wire or titanium cable, locking compression plate, and locking attachment plate fixation. The secondary fixation method was the cerclage of titanium cable, which was required to cover three zones A, B and C to form an overall balanced fixation. The modified Harris hip scores (mHHS), plate length, working length and screw number of different internal fixation combinations were compared.Results:The follow-up time was 54.2±21.6 months (range, 11-86 months). All patients showed signs of fracture healing at 10.2±1.5 weeks (range, 7-13 weeks) after operation, and bony union was observed at 19.6±1.3 weeks (range, 17-22 weeks) after operation. No delayed union or nonunion was observed. After operation, one case had a stress fracture and was revised with double-plate internal fixation; one case had a failed internal fixation and was revised with double-plate internal fixation and a large allograft bone graft. The mHHS score of UCSIV.3B2.1 group (80.3±4.6) was the lowest at 6 months after operation, and the difference between the groups of different types was statistically significant ( F=256.72, P<0.001). The score of simple internal fixation group (91.6±4.2) was higher than that of revision combined with internal fixation group (81.9±4.1), and the difference was statistically significant ( t=8.32, P<0.001). The plate length and working length were 24.9±2.5 cm and 12.6±1.7 cm for UCS IV.3B1.1, 25.4±2.6 cm and 13.6±1.8 cm for 3B2.1 and 28.1±2.5 cm and 4.9±1.9 cm for 3C, respectively ( F=5.33, P=0.005; F=6.78, P<0.001). The number of screws in zone A was significant difference among different UCS types ( F=52.67, P<0.001); UCS IV.3B1.1 (6.5±2.3) and 3B2.1 (6.7±2.2) were more than 3B3 (3.5±1.5) and 3C (3.7±1.6). The number of screws in zone B was significant difference among different UCS types ( F=42.15, P<0.001); The number of UCS IV.3B1.1 (2.3±1.6) and 3B2.1 (2.8±1.9) were significantly more than that of 3B3 (1.0±0.5) and 3C (1.2±0.6). The number of screws in zone C was significant differences among different UCS types ( F=39.62, P<0.001); The number of UCS IV.3B1.1 (3.8±1.9) and 3B2.1 (3.9±1.7) were more than that of 3B3 (2.0±0.5), the difference was statistically significant ( P<0.05). Conclusion:The function of hip after simple internal fixation of proximal femoral periprosthetic fractures was better than that of those who underwent revision at the same time; the number of screws of UCSIV.B1 and B2 is more than that of B3.