Electrocardiogram generation principle is the foundation of learning electrocardiogram and contains the knowledge system of the electrocardial vector,projection and lead system.Teaching contents should be appropriately selected according to the inner logic of the above three knowledge systems and the teaching rule.In classroom teaching,the knowledge of the lead system should be taught by step one,the knowledge of electrocardial vector should be taught by step two and the knowledge of projection should be taught by step three.The three steps help students understand and grasp the mechanism which causes the electrocardiogram more easily.

BACKGROUND: Osteogenesis-related molecules were detected in osteosarcoma tissues, which have closely association with the occurrence, development and prognosis of osteosarcoma. OBJECTIVE: To study the expression of bone morphogenetic protein 7 (BMP-7), vascular endothelial growth factor (VEGF) and core binding factor ?1 (RUNX2) in osteosarcoma cell Lines MG63. DESIGN, TIME AND SETTING: A molecular biology observation was performed at the Central Laboratory of Changhai Hospital between March 2007 and November 2007. MATERIALS: Osteosarcoma cell line MG63 was purchased from Institute of Biochemistry and cell biology, ISBS, CSA. METHODS: Cell line MG63 was counted with blood cell counting, inoculated in 100 mL culture flask with density of 1?104/cm2, stimulated at 37 ℃ with 5% CO2 air and saturated humidity. Then adherent cultured with DMEM containing 10% fetal bovine serum. When the cells reached 70%-80% confluency, the cells were digested with 0.25% pancreatic enzyme for 5 minutes, followed by terminating the digestion with adding DMEM containing 10% fetal bovine serum, and passaged at a ratio of 1:3. MAIN OUTCOME MEASURES: The expressions of BMP-7, VEGF and RUNX2 in MG63 were detected by RT-PCR and immunohistochemistry. RESULTS: BMP-7, VEGF and RUNX2 were positive expressed in MG63. CONCLUSION: The expression of BMP-7, VEGF and RUNX2 in MG63 was confirmed by gene and protein levels, which suggested that osteogenesis-related molecules may play important roles in the development of osteosarcoma.

Objective To explore the use of lamivudine alone induced the poor response,especially the related factors of the occurrence of YMDD.Methods Retrospective analysis of 160 cases of the poor answering cases after lamivudine treatment,the baseline parameter values,the time appearing to the poor answering and the HBVDNA load in treatment were analyzed,to study their relationship with poor response.Results The lamivudine prolonged,the poor response to the probability gradually increase.The mutation rate in the 12nd month was 19.67％ and in the 36th month was 49.18％ ( P ＜ 0.05 ).Response to the many reasons,the YMDD mutation is the more common one.The relationship among HBVDNA load,ALT level on baseline and the rate of poor response emergence,the YMDD mutation rate was clear.By comparison in groups,the difference was significant (P＜0.05).Conclusion The lower baselins of ALT level,the higher of HBVDNA load,the greater probability of the poor response and the YMDD mutation.

Objective To evaluate the effect of montelukast combined with seretide in treatment of patients with asthma and its influence on balance between Th17 and Treg cells, and expression of IL-4 and IFN-γ.Methods 110 patients with asthma were randomly divided into observation group and control group, observation group of 55 cases, using montelukast combined with seretide, control group of 55 cases, using seretide,compared two groups of patients with pulmonary function changes, peripheral inflammatory factor changes and influence on Th17 and Treg cells balance. Results Before treatment, observation group and control group,FEV1 and FEV1 /FVC value was no significant difference.FEV1 and FEV1 /FVC after treatment were significantly improved compared with before treatment in two groups, differences were statistically significance (P<0.05).Between two groups, FEV1 values were significantly difference (t=8.1156, P=0.0001), FEV1 /FVC also had significant difference (t=4.8933, P=0.0001) .Before treatment, observation group and control group, IL-4 and IFN-γdid not have a statistically significant.After treatment, IL-4 and IFN-γdecreased significantly, with statistical difference compared with before treatment (P<0.05).Between two groups, IL-4 had significant difference (t=6.0273, P=0.0001), IFN-γalso had statistically significant (t=6.6042, P=0.0001).Before treatment, there was no significant difference between Th17 and Treg percentage, after 12 weeks of treatment and 24 weeks, Th17 in observation group were(0.53 ±0.02),(0.32 ±0.01), the control group were (0.78 ±0.03),(0.62 ±0.02), which had differences (P<0.05).After 12 weeks and 24 weeks,observation group Treg respectively(2.21 ± 0.22),(2.47 ±0.10),in control group were(1.50 ±0.11),(1.84 ±0.14), Treg percentage at different time after treatment, the differences had statistically significant (P<0.05).Conclusion Montelukast combined with Seretide in treating with asthma, pulmonary function of patients is obviously improved, and it can improve Th17, Treg cell.

Objective To evaluate CT and MRI findings of portal vein aneurysm(PVA)in order to improve its diagnostic accuracy.Methods CT and MRI findings of 9 patients with PVA proved by pathology and direct angiography were reviewed retrospectively.CT scanning was performed in 7 patients,including plain scan (n=2),both plain and enhanced scan (n=5),CT angiography (CTA)(n=3).Plain and enhanced MRI scan were performed in 3 patients.Results (1 )PVA showed a high predilection for old adults.(2 )Of the 9 tumors,4 located in portal vein trunk,2 located in junction of superior mesenteric vein and portal vein trunk,1 located in intrahepat-ic-extrahepatic portal vein,2 located in intra-hepatic portal vein.(3)8 tumors were characterized as well-defined and quasi-circular mass.1 patient occurred portal hypertension,thrombus as the portal vein trunk was oppressed by the tumor.(4)Plain CT showed the mass was slightly higher than pancreas parenchyma density,and uniform with the density of the liver parenchyma.Enhancement scanning showed 4 tumors represented mild or moderate enhancement in portal venous phase except for 1 patient accompany with portal vein thrombus.CTA showed clearly the relationship mass with portal vein,and classified the type of PVA .The 3 lesions represented hypo-intensity on T1 WI and even hyper-intensity on T2 WI.Enhancement scanning showed the tumor was significantly enhancement in portal venous phase on T1 WI.Conclusion CT and MRI have their own advantages in the diagnosis of portal vein aneurysm.Com-bination of CT and MRI could improve the diagnostic accuracy of portal vein aneurysm.

Objective To explore the protective effect of resveratrol (RSV) on intestine barrier injury induced by hemorrhagic shock and its mechanism in rats.Methods According to random number table method,sixty-four SPF grade male Sprague-Dawley (SD) rats were divided into four groups:Sham operation group (only the catheters were indwelled in arterial and venous passages after anesthesia),hemorrhagic shock model group (model group,the catheters were indwelled in arterial and venous passages after anesthesia,and 0.3 mL solvent was administrated after hemorrhagic shock),RSV group (the catheters were indwelled in arterial and venous passages after anesthesia,15 mg/kg RSV was administered after hemorrhagic shock),superoxide dismutase 2 (SOD2) specific inhibitor,2-Methoxyoestradiol (2-ME) group (on the basic treatment of RSV group,0.1 mmol/L 2-ME was administered).The hemorrhagic shock model was reproduced by femoral artery bleeding.After drug administration,all rats were divided into two parts.One part was used for observations on 24-hour survival rate and survival time,while in the other part,2 hours after the hemorrhagic shock,the blood was collected for determination of the content of serum D-lactic acid,and afterward the rats were executed to obtain small intestine tissues for the examination of histopathological changes and Chiu's score.Moreover,differences of expression levels of tight junction proteins (Occludin,Claudin,ZO-1) of small intestine tissue and the oxidative stress related indexes SOD2 activity and reduced glutathione (GSH),oxidized glutathione (GSSH),malonaldehyde (MDA) contents were compared among the groups.Results Compared with the sham group,the model group demonstrated decreased survival rate,SOD2 activity,GSH content,GSH/GSSH ratio,reduced survival time,significantly increased serum D-lactic acid activity,Chiu's score and MDA content,and decreased expressions of tight junction proteins in small intestine tissue.Compared with model group,the RSV group showed significant increased survival rate [75.0％ (6/8) vs.37.5％ (3/8)] and prolonged survival time (hours:21.0±4.3 vs.10.4±5.8,P ＜ 0.05),significantly decreased serum D-lactic acid (μg/L:380.18 ± 70.59 vs.500.88 ± 97.53) and Chiu's score (1.75 ± 0.71 vs.4.00± 0.53) in small intestine (both P ＜ 0.05),obviously increased expressions of tight junction proteins,SOD2 activity,GSH and GSH/GSSG [Occludin (gray value):0.89 ± 0.10 vs.0.43 ± 0.77,Claudin (gray value):0.78±0.06 vs.0.33 ± 0.05,ZO-1 (gray value):0.83 ± 0.06 vs.0.34 ± 0.07,all P ＜ 0.05],and the elevated SOD2 activity (kU/L:0.85 ± 0.12 vs.0.51 ± 0.11,P ＜ 0.05],as well as increased GSH content and GSH/GSSG ratio [GSH (μmol/L):7.25±1.01 vs.3.86±0.54,GSH/GSSG:6.39± 1.14 vs.1.56±0.25,both P ＜ 0.05] in the small intestine,and markedly reduced MDA content (ng/g:5.00± 1.31 vs.8.63±0.92,P ＜ 0.05).Compared with RSV group,the 2-ME group demonstrated significantly decreased survival rate [50.0％ (4/8) vs.75.0％ (6/8)] and further shorter survival time (hours:12.2 ± 5.7 vs.21.0±4.3),increased serum D-lactic acid (μg/L:463.88 ± 60.16 vs.380.18 ± 70.59),obviously elevated Chiu's score (3.13 ± 0.99 vs.1.75±0.71,P ＜ 0.05),decreased expressions of tight junction proteins [Occludin (gray value):0.55±0.04 vs.0.89±0.10,Claudin (gray value):0.38±0.05 vs.0.78±0.06,ZO-1 (gray value):0.41±0.04 vs.0.83±0.06,all P ＜ 0.05];moreover,the activity of SOD2,GSH content,GSH/GSSG ratio were greatly reduced [SOD2 activity (kU/L):0.58 ± 0.13 vs.0.85 ± 0.12,GSH (μmol/L):4.49 ± 0.52 vs.7.25 ± 1.01,GSH/GSSG:1.57 ± 0.39 vs.6.39 ± 1.14,all P ＜ 0.05],and increased MDA content (ng/g:6.25 ± 1.04 vs.5.00 ± 1.31,P ＜ 0.05).The small intestine tissue was basically normal in Sham group,and no significant pathological changes were seen;in the model group,the small intestine epithelial mierovilli were collapsed and the mucosal barrier was destroyed obviously;in the RSV group the damages of small intestine microvilli and barrier were markedly alleviated;in 2-ME group the pathological changes were more evident compared with those in the RSV group.Conclusion RSV can improve intestinal barrier injury following hemorrhagic shock in rats;its mechanism may be related to SOD2 activation.

0.05).Conclusion Acupuncture has an effect on I/O curve amplitude of EPSP and PS,and on LTP induction of PS of dentate gyrus(DG) in rats after cerebral ischemia.However,the difference of effect of acupuncture at different doses on LTP induction is insignificant.

Objective To explore the practice teaching model of human anatomy through re-forming the practice teaching of system anatomy and regional anatomy. Methods Three classes of clinical medicine (5-year program) were randomly selected as reform experimental classes and the other 3 classes of the same grade were used as control classes. The teaching content of practice teach-ing was reformed in the experimental classes. In the system anatomy practice teaching, the teacher controlled the teaching process and developed the theme and requirements of each experimental class while the student completed the experiment developed by the teacher. In the regional anatomy practice teaching, students' interest in learning was stimulated by the content , which was related with the surgery, and the teacher guided students to complete the operation. In control classes, the forms of student observation as well as teacher answering questions and helping students were adopted. The student grading was divided into theoretical knowledge examination and specimen assessment and the achievement was analyzed by using a Simple Analysis of Variance (ANOVA) in SPSS 16.0. Results Compared with those of control classes, the scores of system anatomy and regional anatomy in experi-mental classes were significantly increased (80.7±5.8) vs. (67.4±17.4), (85.1±4.6) vs. (62.6± 12.4) and the theoretical scores of system anatomy were also improved significantly. But no significant difference in theoretical scores of regional anatomy was observed. Conclusions The teaching mode based on the practice teaching highlights the academic characteristics of the human anatomy, increas-es students' interest in learning and improves the effectiveness of practice teaching in human anatomy.

Objective:To investigate the correlation between NKG2A+NK cells and regulatory T cells in peripheral blood of patients with chronic hepatitis B virus infection, and explore the clinical significances.Methods: Forty-six patients with chronic hepatitis B virus infection and 17 health individuals were included in this study.HBV DNA levels were measured by Real-time quantitative PCR ( FQ-PCR) .NKG2A+NK cells and Treg in PBMC were quantitatively analyzed by flow cytometry.Results:According to HBV DNA levels,the CHB patients were divided into two groups:Low HBV DNA group(Low viral load group,300-104 U/ml)and High HBV DNA group( High viral load group,105-108 U/ml).We found that ALT levels of High HBV DNA group were obviously higher than Low HBV DNA group(P<0.05).The frequenies of CD56dim NK cells of High HBV DNA group were obviously higher than low HBV DNA group ( P<0.05 ), and similarly the percentages of NKG2A+CD56dim NK cells of High HBV DNA group were significantly higher than Low HBV DNA and control groups ( P<0.05).We also found that the percentages of regulatory T cells ( Treg) of High HBV DNA group were significantly higher than Low HBV DNA and control groups ( P<0.05).In addition,the proportions of NKG2A+CD56dim NK cells were positively correlated with High HBV DNA levels (r=0.59,P<0.05) and the percentages of Treg(r=0.53,P<0.05) in CHB patients.Conclusion:NKG2A+CD56dim NK cells may closely relate to the HBV-related immune escape and the progress of CHB.

Objective To determine the radiographic feasibility of oblique lumbar interbody fusion (OLIF) corridor to treat lumbar disease at each lumbar disc level,including the corridor's numerical value and the influence of diaphragmatic crura and aorta abdominalis.Methods A retrospective CT study was conducted on 110 patients (including 69 males and 41 females,average age 47.95 years,range 16-83 years) that continuously collected and analyzed in the PACS system.The oblique corridor was defined as the area between the left lateral border of the aorta abdominalis(or iliac artery) and the right lateral border of the left psoas.The distances and angles of L1-2,L2-3,L3-4 and L4-5 levels were measured.Whether the change of diaphragmatic crura and aorta abdominalis affected the building of the corridor was also observed.Results The mean distances of oblique corridor to the levels of L1-L5 discs were:L1-2 15.90 mm,L2-3 14.82 mm,L3-4 17.57 mm,L4-5 11.16 mm.At the levels of L1-2 and L3-4,all of the images could build the corridor.But there were only 97.27％ images allowing operation at both L2-3 and L4-5,and the other 3 cases couldn't build the corridor since the aorta abdominalis was very close to psoas,and the distance was almost 0 mm.The max mean distance was 36.79 mm at L3-4 level.The mean angles were:L1-2 36.98°;L2-3 37.76°;L3-4 40.96°;L4-5 37.85°.The significant difference was at L3-4,ranged from 13.09 to 61.93°.The level of the aortic bifurcation was from the lower third of the L3 vertebral body to the middle third of the L5 vertebral body.The levels of left diaphragmatic crura's ending point in the lumbar was divided into four groups:1) Group L1 vertebral body level:the level at L1 vertebral body and above,5 cases (4.55％);Group L1-2 disc to L2 vertebral body level:at L1-2 disc and L2 vertebral body,67 cases (60.91％);Group L2-3 disc to L3 vertebral body level:at L2-3 disc and L3 vertebral body,36 cases (32.72％);Group L3-4 disc to L4 vertebral body level:at L3-4 disc and L4 vertebral body,2 case (1.81％).Conclusion The OLIF corridor can be built successfully at L1-2 and L3-4.However,it may be difficult at L2-3 and L4-5 for some patients due to the aorta abdominalis which is too close to psoas.The angles of L1-L5 levels were similar.While the left diaphragmatic crura was mainly impact the corridor insertion at L1-2 and L2-3.And the level of the aortic bifurcation was mainly located at the upper endplate of L4 to the L4-5 disc (87％).