This study is to investigate the effects of phenytoin sodium, lidocaine (sodium channel blockers), propranolol (beta-adrenergic receptor antagonist), amiodarone (drugs prolonging the action potential duration) and verapamil (calcium channel blockers) on arrhythmia of mice induced by Bufonis Venenum (Chansu) and isolated mouse hearts lethal dose of Chansu. Arrhythmia of mice were induced by Chansu and then electrocardiograms (ECGs) were recorded. The changes of P-R interval, QRS complex, Q-T interval, T wave amplitude, heart rate (HR) were observed. Moreover, arrhythmia rate, survival rate and arrhythmia score were counted. Isolated mouse hearts were prefused, and the lethal dose of Chansu was recorded. Compared with control group, after pretreatment with phenytoin sodium, broadening of QRS complex and HR were inhibited, and the incidence of ventricular arrhythmia was reduced dramatically, while survival rate was improved; the isolated mouse hearts lethal dose of Chansu was increased significantly. After pretreatment with lidocaine, the prolongation of P-R interval and broadening of QRS complex were inhibited, and the incidences of ventricular arrhythmia were reduced dramatically, while survival rate was improved; the isolated mouse hearts lethal dose of Chansu was increased significantly. After pretreatment with propranolol, prolongation of P-R interval, broadening of QRS complex, prolongation of Q-T interval and HR were inhibited, and the incidences of both supraventricular and ventricular arrhythmias were reduced dramatically, while survival rate was improved. After pretreatment with amiodarone, HR was inhibited, the incidences of ventricular tachycardia were reduced dramatically. Lastly, after pretreatment with verapamil, the prolongation of P-R interval and Q-T interval were inhibited and the incidences of both supraventricular and ventricular arrhythmias were reduced dramatically; the isolated mouse hearts lethal dose of Chansu was reduced significantly. In in vivo experiments, phenytoin sodium was most effective against the mice arrhythmias induced by Chansu while cautious use of verapamil for Chansu inducing arrhythmia should be noted. It is also concluded that mice ventricular arrhythmias induced by Chansu might be most closely related to sodium channel, supraventricular arrhythmias might be related to beta-adrenergic receptor, and calcium channel plays an important role in conduction block. In in vitro experiments, phenytoin sodium was most effective, followed by lidocaine and propranolol, and amiodarone had no obvious effect and verapamil reduced the lethal dose of Chansu.

Objective To investigate the effect of mitogen-activated protein kinase(MAPK)pathway on the transcriptional expression of mdr1 gene induced by doxorubicin ( DOX)and study the transcription regulation of mdr1 gene.Methods K562 cells were treated with DOX(0.01 μg/ml)with the initial concentration of 0.01 μg/ml for 24 hours,then change the culture media without DOX.K562 cells were cultured until the its status wag recovered.Subsequently the cells were treated with DOX(0.02μg/ml)for 24 hours again.The concentration of DOX was increaged until 0.05 μg/ml by following the protocol above.K562 cells were collected at the concentration of 0.01 μg/ml,0.03μg/ml and 0.05μS/ml DOX.Expression of mdr1 gene were examined by reverse transcription-polymerase chain reaction(RT-PCR).Pglycoprotein(P-gP)wag detected by flow cytometry.Western blot wag performed to detect ERK and P-ERk.K562 cells were pretreated with MAPK inhibitor PD98059 for 1 hour.and then DOX was added.RT-PCR and FCM were used to detect the expression of mdr1 mRNA and P-gp.Results When K562 cells were exposured to DOX.the phosphorylation of ERK wag increaged.the mdr1 gene wag highly expressed as well as its corresponding protein P-gp.When the concentration of DOX was 0.05μg/ml,the expression of mdr1 gene and P-gp were increased over 5 fold.When K562 cells were pretreated with MAPK inhibitor PD98059,the expression of mdr1 gene induced by DOX(the concentration was 0.03 μg/ml and 0.05 μg/m1)was effectively inhibited by(74.1±0.11)%and(70.2±0.14)%respectively.Conclusions DOX could induce the expression of mdr1 gene in K562 cells accompanied by the activation of MAPK/ERK pathway.The block of activation of ERK could inhibit the induced expression of mdr1 gene.

Objective To investigate the clinical epidemiological features of femoral neck frac-tures. Methods The clinical data of patients with femoral neck fractures admitted to Third Affiliated Hospital of Hebei Medical University from 2003 to 2007 were retrospectively analyzed. All patients were divided into children group (age < 16 years) , adult group (age ranged from 16 to 60 years) and older group (>60 years). The types of the femoral neck fractures included 31-B1, 31-B2 and 31-B3 according to AO classification. The gender, age, fracture type and injury causes were analyzed. Results A total of 2 064 patients (971 males and 1 093 females) with femoral neck fractures were involved in the study.There were 356, 381, 397, 454 and 476 patients respectively in 2003, 2004, 2005, 2006 and 2007.There were 74 patients (3.59%) in the children group, 979 (47.43%) in the adult group and 1 011 (48.98%) in the older group. There were 960 patients (46. 51%) with type 31-B1 fractures, 860 (41. 67%) with type 31-B2 fractures and 244 (11. 82%) with 31-B3 fractures. Conclusions Form 2003 to 2007, the incidence of femoral neck fracture shows a trend of increase, with the highest incidence in the old persons. The male patients with femoral neck fractures are more than female patients in adult group, while the female patients with femoral neck fractures are less than male patients in older group.The dominant fractures type according to AO classification are type 31-B2 fractures in children and adult groups, but type 31-B1 fractures in older group.

Objective:To investigate the role and influencing factors of case design in PBL teaching.Methods:Thirty-two six-year-program undergraduates from the Department of Medicine of Peking University in batch 2014 and batch 2015 were selected as the subjects. PBL teaching was used in the practice class of experimental diagnostics. The feedback effects of four times PBL courses were analyzed by collecting questionnaires for teachers, students, and supervisors. The data obtained from the five-point questionnaire and the question-and-answer questionnaire were analyzed by one-way ANOVA and statistics respectively. Then the problems in case preparation process are discussed and the experience of case design is summarized. SPSS 13.0 was used in this study.Results:The 5-point questionnaire showed that the average score of anemia PBL course was the highest among students' self-evaluation and mutual evaluation of teachers and students (4.84 points, 4.79 points), with statistical significance compared with other courses ( P<0.05). The question-and-answer questionnaire survey showed that 93.75% of the students generally agreed with the teaching model of anemia cases; 78.13% and 59.38% of the students believed that it was difficult to set up cases of infection and coagulation, which affected the classroom effect; and 50% of the supervisors thinked that the students' level should be taken into account in case design and oral expression should be avoided. Conclusion:Case design is the key to PBL teaching. Summarizing the experience of case design can lay a good foundation for the establishment of PBL teaching database.