OBJECTIVE To observe Staphylococcus aureus(SAU) infection at high altitude and plain after gunshot injury. METHODS Used 7.62mm bullets to injure posterior limbs of piglets with the same age.We got contusing tissues in different time after injury,to make bacteriologic examination,identify and make a statistic analysis of SAU. RESULTS The main infection was caused by SAU after gunshot injury in two regions.From contusing tissues in two regions,the rate of contamination caused by SAU in Chongqing and Lasa was 48% and 18%,respectively.The time of SAU colonization was 3 hours at high altitude,and less 3 hours at plain.The velocity of reproduction of SAU at high altitude for 12 hours was 5-6 passages,and at plain was 4-6 passages for 3-6h.The time of remaining relative steady state between tissues and germs was 48 hours at high aititude and 24 hours at plain.The difference of the number of SAU between two regions after injury 3-36 hours was significant,But after 36 hours the difference was unsignificant. CONCLUSIONS At high altitude region,SAU is the main germ that causes contamination after gunshot injury,the velocity of reproduction of SAU is slower than that at plain,the time of infection is delayed obviously.

To explore the organ-system oriented integrated program, this project constructed a new clinical skill training program of sensory system for"5+3" medical students. According to the current trend and requirement of medical teaching reform, taking into consideration of the present status of clinical skills teaching, this project integrated the basic and clinical teaching contents of otolaryngology, ophthalmology and dermatology to design a new training program of clinical skills for"5+3"medical students. Specifically, the project group edited a new textbook and syllabus, and set up a specialized teaching group. In this system, the training models included simulation training and practical bedside training, the assessment included operation ability and analyzing ability for clinical cases, and the training contents involved all conventional skills of each specialty. It has been demonstrated that the new training program is capable of promoting the clinical skills of students quickly and effectively.

Objective: To investigate the urine methyl tert-butyl ether (MTBE) level of a primary school students in Changping District, Beijing, and analysis the effect factors, give the advice if the MTBE is eligibility as an exposure biomarker of automobile exhaust. Methods: Using the panel study, randomly selected 20 sixthgrade students (10 male and 10 female) from Zhixing School in Changping district, Beijing, from June 7th to 13th, 2018. All participants completed a questionnaire for collecting demographic and geographic information and daily activities. All participants were given guidance to repeatedly collected urine samples 3 times (8:00, 11:00 and 16:00 instant urien) a day for 7 days, totally 420 urine samples were collected. Urine MTBE were measured and the statistic significant of the Urine MTBE at different groups were evaluated. Results: MTBE were detected in all 420 urine samples of primary school students, the geometric mean of creatinine-corrected MTBE exposure level in 8:00, 11:00 and 16:00 instant urine were 0.12, 0.12 and 0.12 mg/g creatinine, respectively. Urine MTBE concentration was statistical significant in different daily outdoor activity time, the distance of home address to the main road, and daily use time of air purification equipment in class(P=0.00, 0.04, 0.00). Conclusion There was a universal MTBE exposure among students in a primary school in Beijing, and the impact factors to exposure level were daily outdoor activity time, distance from home address to the closest main road, and daily use time of air purification equipment in class. This result indicate MTBE may be a valuable candidate for exposure biomarker of automobile exhaust, and more research should be done.

OBJECTIVETo explore the effect of colon cancer cell-derived interleukin-1α on the migration and proliferation of human umbilical vein endothelial cells as well as the role of IL-1α and IL-1ra in the angiogenesis process.

METHODSWestern blot was used to detect the expression of IL-1α and IL-1R1 protein in the colon cancer cell lines with different liver metastatic potential. We also examined how IL-1α and IL-1ra influence the proliferation and migration of umbilical vascular endothelial cells assessed by PreMix WST-1 assay and migration assay, respectively. Double layer culture technique was used to detect the effect of IL-1α on the proliferation and migration of vascular endothelial cells and the effect of IL-1ra on the vascular endothelial cells.

RESULTSWestern blot analysis showed that IL-1α protein was only detected in highly metastatic colon cancer HT-29 and WiDr cells, but not in the lowly metastatic CaCo-2 and CoLo320 cells.Migration assay showed that there were significant differences in the number of penetrated cells between the control (17.9±3.6) and 1 ng/ml rIL-1α group (23.2±4.2), 10 ng/ml rIL-1α group (31.7±4.5), and 100 ng/ml rIL-1α group (38.6±4.9), showing that it was positively correlated with the increasing concentration of rIL-1α (P<0.01 for all). The proliferation assay showed that the absorbance values were 1.37±0.18 in the control group, and 1.79±0.14 in the 1 ng/ml rIL-1α group, 2.14±0.17 in the 10 ng/ml rIL-1α group, and 2.21±0.23 in the 100 ng/ml rIL-1α group, showing a positive correlation with the increasing concentration of rIL-1α(P<0.01 for all). IL-1ra significantly inhibited the proliferation and migration of vascular endothelial cells (P<0.01). The levels of VEGF protein were (1.697±0.072) ng/ml, (3.507±0.064)ng/ml and (4.139±0.039)ng/ml in the control, HUVECs+ IL-1α and HUVECs+ HT-29 co-culture system groups, respectively, showing a significant difference between the control and HUVECs+ 10 pg/ml rIL-1α groups and between the control and HUVECs+ HT-29 groups (P<0.01 for both).

CONCLUSIONSOur findings indicate that colon cancer cell-derived IL-1α plays an important role in the liver metastasis of colon cancer through increased VEGF level of the colon cancer cells and enhanced vascular endothelial cells proliferation, migration and angiogenesis, while IL-1ra can suppress the effect of IL-1α and inhibit the angiogenesis in colon cancer.

Blotting, Western ; Caco-2 Cells ; Cell Line, Tumor ; Cell Movement ; physiology ; Cell Proliferation ; physiology ; Coculture Techniques ; Colonic Neoplasms ; blood supply ; metabolism ; pathology ; Human Umbilical Vein Endothelial Cells ; cytology ; Humans ; Interleukin 1 Receptor Antagonist Protein ; metabolism ; physiology ; Interleukin-1alpha ; metabolism ; physiology ; Liver Neoplasms ; secondary ; Neovascularization, Pathologic ; etiology

Objective:To investigate the teaching effect of flipped classroom combined with problem-based learning (PBL) in the teaching of the Diagnostic Audiology course.Methods:A total of 72 undergraduate students majoring in audiology and speech rehabilitation in the classes of 2019 and 2020 in Chongqing Medical University were enrolled as subjects, and three chapters of the Diagnostic Audiology course were selected for teaching reform. The 34 students in the class of 2019 were enrolled as control group and received lecture-based learning (LBL), and the 38 students in the class of 2020 were enrolled as experimental group and received flipped classroom combined with PBL. The teaching effect was evaluated by comparing the two groups in terms of classroom test scores, classroom participation scores, degree of satisfaction with teaching effect, and overall satisfaction with teaching. SPSS 23.0 software was used to perform the t-test, the chi-square test, and the Mann-Whitney U test. Results:The experimental group had a significantly higher classroom test score than the control group (25.95±1.21 vs. 23.21±1.55, P<0.001). In terms of classroom participation scores, the experimental group had significantly higher scores of participation in class discussion, cooperative and collaborative abilities, and questioning skills than the control group (all P<0.001). In terms of the degree of satisfaction with teaching, compared with the control group, the experimental group had significantly higher degrees of satisfaction in the dimensions such as interest in learning, mastery of theoretical knowledge, teamwork and collaboration abilities, self-learning ability, and self-presentation ( P=0.005, 0.009, 0.001, 0.016, and 0.005). In addition, the experimental group had a significantly higher degree of overall satisfaction with teaching than the control group ( P=0.006). Conclusion:Flipped classroom combined with PBL has a good teaching effect in the Diagnostic Audiology course and thus holds promise for further application.

Objective:To investigate the effects of hepatitis B virus X (HBx) on hepatocellular carcinoma (HCC) proliferation, invasion, and sorafenib resistance.Methods:HepG2 cell line infected with HBx ORF lentivirus was set as the HBx high expression group and infected with empty vector was set as the negative control group. The interference group was infected with the HBx siRNA virus based on the HBx high expression group to reduce HBx expression. Interference control group as interference group but with infected empty vector virus. Western blotting was used to measure the protein level of HBx. Cell proliferation, invasion ability, and sorafenib semi-inhibitory concentration (IC50) of HCC cells under different HBx expression levels were respectively detected by cell proliferation assay kit, Transwell invasion assay, and cell titer-glo kit.Results:Western blotting showed that the stable cell lines were successfully established. Cell proliferation of the HBx high expression group was better than that of the blank control and negative control groups, and the cell proliferation of the interference group was lower than that of the interference control and HBx high expression groups, and the differences were all statistically significant ( P<0.05). The number of cells crossing Matrigel gel was (46.2±4.1), (50.7±5.1) and (48.2±5.2) in the blank control group, negative control group, and interference group, respectively. The number of cells crossing Matrigel gel in the HBx high expression group (124.2±8.3) and the interference control group (117.2±7.5) were higher than the above three groups, respectively, and the differences were all statistically significant ( P<0.05). The IC50 of cells in the HBx high expression group and the interference control group were (5.36±0.31) μmol/L and (5.48±0.20) μmol/L, respectively, which were higher than those in the blank control group, the negative control group, and the interference group (4.75±0.22) μmol/L, (4.60±0.14) μmol/L and (3.98±0.03) μmol/L. The differences were all statistically significant ( P<0.05). Conclusion:HBx promoted the tumor proliferation and invasion of HepG2 HCC cells, enhanced the ability to sorafenib resistance, and inhibited apoptosis.

ObjectiveTo systematically review the efficacy and safety of laparoscopic choledochoscopy combined with holmium laser lithotripsy through a meta－analysis. MethodsThis study was conducted based on PRISMA guidelines， with a PROSPERO registration number of CRD42023406221. Chinese databases including CNKI， Wanfang Data， and VIP and foreign language databases such as PubMed， Embase， the Cochrane Library， and Web of Science were searched for original articles on traditional laparotomy versus laparoscopic choledochoscopy combined with holmium laser lithotripsy in the treatment of bile duct stones. Dichotomous variables were assessed by odds ratio （OR） and 95% confidence interval （CI）， while continuous variables were assessed by weighted mean difference （WMD） and 95%CI， and a sensitivity analysis was performed for outcome measures with relatively high heterogeneity. The Begg test and Egger test were used to evaluate publication bias. Stata 15.0 and Review Manager 5.3 were used to perform the statistical analysis. ResultsA total of 26 retrospective studies from China were included in this study， with 2 238 patients in total. The meta－analysis showed that compared with traditional laparotomy for the treatment of bile duct stones， laparoscopic choledochoscopy combined with holmium laser lithotripsy had significantly shorter time of operation （WMD＝－1.26， 95%CI： －1.36 to －1.16， P<0.001）， length of hospital stay （WMD＝－1.93， 95%CI： －2.64 to －1.12， P <0.001）， and time to bowel function recovery （WMD＝－1.52， 95%CI： －1.68 to －1.35， P<0.001）， significantly less intraoperative blood loss （WMD＝－1.79， 95%CI： －1.93 to －1.66， P<0.001）， a significantly lower rate of intraoperative residual stone （OR＝0.15， 95%CI： 0.11－0.20， P<0.001）， and significantly fewer complications （OR＝0.17， 95%CI： 0.13－0.23， P<0.001）. ConclusionCompared with traditional laparotomy， laparoscopic choledochoscopy combined with holmium laser lithotripsy shows better efficacy in the treatment of bile duct stones.