Objective To investigate the effect of 5‐fluorouracil on hypertrophic scar in rabbit ears .Methods The hyper‐trophic scar models in rabbit ears were reproduced and randomly divided into 3 groups (group A ,group B and group C) .On postop‐erative 60th days ,Hematoxylin‐eosin and Masson staining staining was applied to observe themorphological and collagen change of scars under light microscope .Real‐time PCR and ELISA were conducted to detect the expression of TGF‐β,PDGF ,bFGF and INF‐γ .Results HE and Masson staining showed that thinner dermis ,fewer fibroblasts and collagen fibers ,collagen fibers arranged reg‐ularly and less collagen nodule was observed group B compared with the group A and group C .Furthermore ,we found that TGF‐β, PDGF ,bFGF ,INF‐γmRNA and protein expression levels were significantly lower in group B and group C than the group A ,and group B was more effective than group C .Conclusion 5‐fluorouracil is effective for the treatment of hypertrophic scars ,and the lo‐calized injection of 5‐fluorouracil is more effective than the ointment group .

OBJECTIVE To investigate the ESBLs produced by clinical strains of Enterobacter cloacae.METHODS Production of ESBLs was identified with modification of the double-disk test(MDDT).Eight kinds of primers(CTXM,CTXM-1,CTX-M-2,CTX-M-9,SHV,TEM,VEB,and PER)were used for the PCR amplification.Gene clone and DNA sequencing were performed then.RESULTS The result of MDDT was positive,amplicons were gained by PCR amplification with CTXM-1.DNA sequencing of amplicons of this strain revealed ESBLs of CTX-M-3.CONCLUSIONS ESBLs are the important reason for E.cloacae resisting to the third-generation cephalosporins.

In vitro cell culture of head and neck tumors and chemosensitivity test to select sensitivity antitumor bogs for individual chemotherapy. Methods:The chemosensitivity of 32 fresh specimens of human head and neck tumors were tested with MTT assay and eight atitumor drugs． Results:The sensitivity was 84.4% for 5-Fu, 2l.9% for VCR, 62.5% for MTX, 8l.3% for BLM, 8l.3% for DDP, 40.6% for ADM, 65.6% for PYM and 3.l% for CTX． The results of chemotherapy with sensitivity drugs of 32 patients were encouraged． There were no serious side-effects in the chemotherapy and no recurrence and metastasis after the treatment． 32 patients were still alive． Conclusion: Chemosensitivity test of tumor cell lines with MTT assay was accuracy， fast，simple，ecoromical，effective method and was valuable for chemotherapy．

Objective To understand the blood pressure variability (BPV) and the influencing factors through ambulatory blood pressure monitoring during hemodialysis (HD) in the end-stage renal disease (ESRD) patients.Method Eighty-one ESRD patients on maintenancing HD for more than three months were enrolled into the study.The patients were with properly dry body weight.The blood pressure was monitored using dynamic blood pressure monitor around the HD.BPV was estimated with the coefficient of variation (CV) and standard deviation (SD) of the systolic blood pressure (SBP-CV,SBP-SD).Patients were divided into two groups according to the mean of SBP-CV:high SBPV group and low SBPV group.The possible influencing factors such as age,dialysis duration,ultrafitration volume,ultrafiltration/body weight,therapy of antihypertensive,electrolyte,nutrition state,metabolic bone disease indexes,inflammatory state and serum lipid state were analyzed and compared between the two groups.And multivariate stepwise regression analysis was made between the SBP-CV,SBP-SD and the above observational parameters.Results The average SBP-CV of the 81 patients was (8.12± 3.16)％,SBP-SD was (11.22±4.55) mm Hg.The proportion of hypertention and hypotention in high SBPV(SBP-CV≥8.12％) group (20.0％,25.7％) was higher than that in the low SBPV(SBP-CV ＜8.12％) group (8.7％,6.5％)(P =0.009).Serum high-sensitivity c-reactive protein (hs-CRP) and alkaline phosphatase (ALP) were higher in high SBPV group than that in the low SBPV group[(7.19± 5.95) mg/L vs (3.35±2.78) mg/L,P =0.001 and (180.31±96.32) U/L vs (98.00±41.19) U/L,P =0.049].Serum creatinine and potassium were higher in the low SBPV group than that in the high SBPV group [(1015.83±276.20) μmol/L vs (893.63±216.61) μmol/L,P =0.034 and (5.27±0.78) mmol/L vs (4.80± 0.23) mmol/L,P =0.005].SBP-SD was positively correlated with hs-CRP (β =0.499,P ＜ 0.01),SBP-CV was positively correlated with hs-CRP and dialysis vintage (β =0.464 and 0.211,P ＜ 0.01 and P ＜ 0.05) by the multivariate stepwise regression analysis.Conclusions The SBP-CV during HD is 8.12％ in ESRD patients.Hypertention and hypotention are more often in the higher SBPV patients.SBPV is closely related to the serum hs-CRP.

Objective To investigate the correlation between microvessel density (MVD) and expression of NET-1 protein in bladder carcinoma and its prognostic significance. Methods The expression NET-1 protein and MVD marked with CD_ 105 in 43 cases of bladder carcinoma and 10 normal bladder tissues were measured by means of immunohistochemistry SP.The association between them and the relation ship with WHO pathology classification,TNM stage and prognosis were studied. Results MVD were correlated with WHO pathology classification,TNM stage and prognosis (F_1=17.01,F_2=12.06,P

Objective:To compare the prediction efficiency of traditional linear regression model and four machine learning models on the learning behavior of clinical medical postgraduates, and to explore the pros and cons and applicability of different prediction models.Methods:A total of 6,922 clinical medical postgraduates were surveyed, their comprehensive learning behavior scores were obtained through the learning behavior scale. In the training set, Lasso linear regression and artificial neural network, decision tree, Bootstrap random forest, and lifting tree were used to build prediction models respectively. The above models were used to predict the validation set data and compare the prediction efficiency.Results:The comprehensive learning behavior score of clinical medical postgraduates was (3.31±0.54) points, and the overall compliance rate was 74.02%. In the linear regression model, the influence of age, school level, degree type, learning interest, pressure and satisfaction on learning behavior were statistically significant. In the prediction of validation set, the sensitivity, specificity, and accuracy of the linear regression model were 0.484, 0.914, and 0.801, respectively. The indexes of the four machine learning models were higher than those of the traditional linear regression model, and the Bootstrap random forest had the highest elevation.Conclusion:The linear regression model has a good prediction effect on learning behavior, and machine learning is superior to linear regression model in terms of accuracy of prediction. However, traditional linear regression models are superior to machine learning models in computational efficiency and interpretability.

BACKGROUND: Existing evidence has shown that that the effect of NGF/TrkA signaling pathway on proliferation and differentiation of tumor cells is closely related to PI3 K/AKT signaling pathway in human benign and malignant tumors. However, there is little information on the NGF/TrkA signaling pathway in pathogenesis of intraspinal schwannomas. OBJECTIVE: To investigate the effect of nerve growth factor-beta on the proliferation of interspinal schwannoma cells and to explore on the pathogenesis of NGF/TrkA signaling pathway in interspinal schwannoma. METHODS: Tumor samples were collected and digested to obtain high purity tumor cells as experimental cells. Then the cells were given different concentrations of nerve growth factor-beta (15, 30, 60, 120 and 240 μg/L), K252 a (100, 200, 300, 400, 500 and 600 nmol/L), LY294002 (10, 20, 30, 40, 50 and 60 μmol/L), nerve growth factor-beta (120 μg/L) plus K252 a (TrkA inhibitor, 400 nmol/L), and nerve growth factor-beta (120 μg/L) plus LY294002 (P13 K inhibitor, 50 μmol/L), respectively, for a certain time. The cell proliferation was detected by MTT assay. TrkA, AKT, p-AKT (Ther308), p-GSK-3 beta protein expression was detected by western blot assay. TrkA and AKT mRNA expression was detected by RT-PCR. RESULTS AND CONCLUSION: (1) Compared with the control group, the absorbance value of cells in the nerve growth factor-beta groups was increased in a concentration-dependent manner (P ＜ 0.05), and increased obviously at the concentration of 120 μg/L (P ＜ 0.001). The absorbance value of cells in the K252 a and LY294002 groups was decreased continuously (P ＜ 0.05), and decreased obviously at the concentration of 400 nmol/L and 50 μmol/L, respectively (P＜ 0.001). (2) The expression levels of TrkA, p-AKT (Ther308), and p-GSK-3 beta protein were upregulated in the nerve growth factor-beta group (P ＜ 0.05), and the expression level of TrkA mRNA was upregulated (P ＜ 0.05). (3) In the nerve growth factor-beta (120 μg/L) plus K252 a (400 nmol/L) group, the absorbance value of cells decreased (P ＜ 0.001). The expression levels of TrkA, p-AKT (Ther308), and p-GSK-3 beta protein downregulated (P ＜ 0.05), and the expression level of TrkA mRNA downregulated (P ＜ 0.05). (4) In the nerve growth factor-beta (120 μg/L) plus LY294002 (50 μmol/L) group, the absorbance value of cells decreased (P ＜ 0.01), and the expression levels of p-AKT (Ther308), and p-GSK-3 beta protein downregulated (P ＜ 0.05). (5) There was no significant change in AKT protein and mRNA in each group (P＞ 0.05). (6) These results suggest that nerve growth factor-beta can promote interspinal schwannoma cell proliferation, which may be related to the expression of TrkA, p-AKT (Ther308) and p-GSK-3 beta protein in NGF/TrkA signaling pathway.

Objective To compare the efficacy and safety of levofloxacin 750 mg for 5 days versus 500 mg for 7‐14 days intravenous (IV ) infusion in the treatment of community‐acquired pneumonia (CAP ) . Methods This study was a multi‐center , randomized , open‐label , non‐inferiority , controlled clinical trial .The CAP patients were randomized to receive levofloxacin 750 mg IV daily for 5 days or levofloxacin 500 mg IV daily for 7‐14 days .The clinical symptoms , laboratory tests , imaging results and microbiology data were collected and compared between the two treatment groups in terms of efficacy and safety .Results A total of 241 patients were enrolled in this clinical trial from 10 study centers .Among these patients ,223 were eligible for full analysis set (FAS) analysis ,including 111 in 750 mg group and 112 in 500 mg group .Of the 223 patients in FAS ,211 were eligible for per‐protocol set (PPS) analysis ,including 107 in 750 mg group and 104 in 500 mg group .Two hundred and forty‐one patients were included in safety set (SS) ,including 121 patients in 750 mg group and 120 in 500 mg group .The median treatment duration was 5 .0 days in 750 mg and 9 .0 days in 500 mg group .The median total dose was 3 750 mg in 750 mg group and 4 500 mg in 500 mg group .The overall efficacy rate was 86 .2% in 750 mg group and 84 .7% in 500 mg group in terms of FAS at visit 4 ,which suggested that the efficacy of 750 mg group was non‐inferior to 500 mg group .Of the 111 FAS patients in 750 mg group ,40 were bacteriological evaluable ,and 41 strains of pathogens were isolated .Forty‐nine of the 112 FAS patients in 500 mg group were bacteriological evaluable ,and 51 bacterial strains were obtained .The bacterial eradication rate was 100% in both groups .The clinical treatment efficacy rate for atypical pathogens was 100% in both groups .In 750 mg group ,the most common clinical adverse drug reactions (ADRs) were injection site adverse reactions including injection site pruritus ,pain and hyperemia .The other common ADRs were insomnia ,nausea ,skin rash .The most common drug‐related laboratory abnormalities were neutrophil percentage decreased , decreased white blood cell (WBC ) count , alanine aminotransferase (ALT) and aspartate aminotransferase (AST) elevation .Most of the ADRs were mild in severity and well‐tolerated .The safety profile of the two treatments was comparable in terms of the drug‐related treatment discontinuation and the incidence of ADRs .Conclusions The short‐course regimen of levofloxacin 750 mg IV for 5 days is at least as effective and well tolerated as the long‐course regimen of 500 mg IV for 7‐14 days in treatment of CAP .

Objective: To describe the prevalence and relationship between moderate to vigorous physical activity(MVPA), screen time (ST) and depressive symptoms among middle school students in Guangzhou, and to provide a reference for adolescent depression prevention and control. Methods: Using stratified cluster random sampling method, a total of 2 140 students were selected from one urban area and one suburban country for MVPA, ST and depressive symptoms investigation. Logistic regression was used to analyze relations among MVPA, ST and their combined patterns for depressive symptoms. Results: A total of 89.72% students failed to meet the MVPA recommendations, girls (95.52%) were higher than boys(84.38%). Totally 67.38% of the students failed to meet the ST recommendations, boys (69.75%) were higher than girls(64.81%). The prevalence of depressive symptoms was 27.01%, girls (31.58%) higher than boys(22.80%). MVPA, ST failure compliance rate and depression symptoms detection rate of vocational high school and ordinary high school were higher than junior high school ( χ 2=6.40,121.71,27.37, P ＜ 0.05 ). Logistic regression analysis showed that the OR for depressive symptoms was 1.19 ( P =0.35) in students whose MVPA time achieving 1 h<7 d in the last week, and was 1.93 ( P <0.01) in students with the ST>2 h/d independently, no significant interactions were observed. Students with both MVPA time 1 h<7 d in the last week and the ST>2 h/d were more likely to report depressive symptoms( OR=2.03, P <0.05). Conclusion Insufficient MVPA, prolonged ST and high prevalence of depressive symptoms are observed among middle school students in Guangzhou. Students with both insufficient MVPA and prolonged ST are more likely to suffer from depressive symptoms. Specific psychological care and health education regarding physical activity and screen behavior should be implemented to students with different characteristics, as well as their parents for depressive symptom prevention.

Objective: To investigate the general situation of scoliosis and influencing factors among middle school students in Guangzhou, so as to provide evidence for behavioral intervention measures. Methods: By stratified cluster random sampling method, 2 121 students from 8 middle schools of Guangzhou were selected to conduct questionnaire survey and physical examination. Results: The detection rate of scoliosis among middle school students in Guangzhou was 8.20%, girls (9.50%)＞boys (7.00%), urban area (10.45%)＞suburb area (4.77%), senior high school (10.08%)＞junior school (6.39%) ( P ＜0.05). Among the most of the 174 positive students were found to have large thoracic curve, right lateral bending, being girls with medium scoliosis. Multivariate Logistic regression analysis showed that students in urban area ( OR=2.56, 95%CI =1.71-3.82), with mobile electronic devices usage time≥3 h/d( OR=1.59, 95%CI =1.12-2.27), prolonged near vision work ≥1 h ( OR=1.40, 95%CI =1.00-1.95), outdoor activity time＜2 h/d( OR=1.82, 95%CI =1.24-2.67) had a higher detection rate of scoliosis ( P <0.05). Conclusion The detection rate of scoliosis among middle school students in Guangzhou is much higher, which might be related to district, mobile electronic devices usage, prolonged near vision work and insufficient outdoor activity. Health education regarding spinal knowledge should be strengthened.