ABSTRACT
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.
ABSTRACT
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.