Problem-based Learning(PBL)is a teaching approach focusing on students under the constructivism theory.In such a teaching approach,problems are essential.The thesis discusses the theoretical basis of the problem designment in PBL,namely the forms of problems,their functions,and principles in the problem designment under the constructivism theory.

Objective Examinating the efficacy and safety on prophylaxis of deep venous thrombosis(DVT) following arthroplasty using low-molecular-weight heparin (LMWH) in combination with intermittent pneumatic compression(IPC) starting with different time. Methods 156 patients undergoing primary arthroplasty from July 2003 to June 2005 were divided into four groups randomly. In the first group, 38 patients used LMWH preoperatively and IPC starting since anesthesia. In the second group, 42 patients did LMWH postoperatively and IPC starting since anesthesia. In the third group, 36 patients did preoperative LMWH and post-operative IPC. In the fourth group, 40 patients did post-operative LMWH and IPC. All patients were examined by colour duplex ultrasonography, valued the clinical symptom of DVT, recorded the volume of blood loss in perioperation and observed complication of hemorrhage. Results In the first group, two cases of DVT (5.26%) were found and the average perioperative volume of blood loss was (1030.8?282.0) ml. In the second group, two cases of DVT (4.76%) were found and the average volume of blood loss was (900.7?246.9) ml. In the third group, one case (2.78%) of DVT was found and the average volume of blood loss was (1040.3?288.5) ml. In the fourth group, nine cases of DVT (22.5%) were found and the average volume of blood loss was (852.2?295.4) ml. Comparing the incidence of DVT between each group, group 1, 2, 3 were lower than group 4(P﹤0.05). Comparing the volume of blood loss in perioperation, group 2 , 4 were less than group 1,3(P﹤0.05). Conclusion On the basis of this study, it is more effective and safer using LMWH staring with post-operative 10 h in combination with IPC starting with anesthesia on prophylaxis of DVT following arthroplasty.

Objective To discuss perioperative features, operative approach and surgical effects of spinal tuberculosis in older patients. Methods Retrospective analysis was conducted to analyze the clinical data of 45 patients with spinal tuberculosis ranging in age from 61 to 78 years (average, 67 years). The lesion was located in thoracic vertebrae in 9 patients, thoracolumbar vertebrae in 14, lumbar in 16, and lumbosacral in 6. Preoperative Frankel grades were B in 7 cases, C in 21, D in 11 and E in 6. Among them, 21 had cardio-cerebrovascular disease, 10 had diabetes mellitus. With preoperative medicine and chemotherapy for 2-3 weeks, all patients were treated surgically. The surgical procedures included: 1) Posterior focus debridement, bone grafting and one-stage posterior transpedicular screw system fixation in thoracic vertebrae (T2-T7). 2) Anterior debridement, bone grafting and one-stage posterior transpedicular instrumental fixation in lumbosacral vertebrae (L5-S1). 3) Anterior focus elimination, bone grafting and one-stage anterior plate fixation in the other vertebrae. Results Forty-five patients were followed up for 24 to 40 months, with the average of 28.5 months. No severe complication occurred during and after operation. Forty-four cases had recovered and 1 recurred. Spinal fusion occurred 12-18 months after operation. Frankel neurological grades improved significantly. Conclusion With the effective management of comorbidities in perioperative period,the elderly could tolerate surgical treatment. The appropriate approaches, thorough debridement and reasonable bone grafting with internal fixation are key to therapeutic success.

Objective To investigate the mechanism of recombinant human growth hormone(rhGH) in articular cartilage defect repair in vivo.Methods The cylindrical,full-thick articular cartilage defects,(3.5 mm) in diameter,were made in the knee joints of 25 rabbits.rhGH of 0.1 U/kg was injected into the right knee joints 3 times a week for 4 weeks and equal volume of physiological saline to the left knee joints as control.The animals were killed respectively in 4,6,8,12,24 weeks,and the macroscopic,histologic and ultrastractural examinations were performed.Results The repairing process in experimental group was faster and better than that in the control.In the experimental groups,the defect was filled on week 4,the regenerated cartilage mainly in the shallow region and fibrous tissue in the deep region;on week 24,the regenerated tissue was morphologically close to the neighbour normal cartilage,hard to differentiate by macroscopy;Light microscopy showed the defect recovered to normal cartilage structure and the electron microscopy showed a large quantity of mature cartilage cells.In the control groups,the defect was of shallow introcession,mainly of fibrous tissue.The histological examination showed the significant difference between experimental and control groups(P

Objective To investigate the efficacy and toxicities of gemcitabine and cisplatin as a chemother-apy regimen for patients with advanced non-small cell lung cancer (NSCLC). Methods Thirty-five patients with NSCLC were enrolled in this study. C, emeitabine was given on day 1 and 8 at a dose of 1000 mg/m~2 and cisplatin at a dose of 25 mg/m~2 on day 1 to 3. The chemotherapy was repeated every 28 days, after 2 cycles for evaluating response. Results Complete response (CR), partial response (PR) ,stable disease (SD) and progressive disease (PD) were observed in 0,14,16 and 5 cases, respectively, with a response rate (RR) of 40. 0%. The RR in initial treatment group was found more than that in the retreatment group (52. 2% vs 16.7% ,P<0. 05).The main toxicities were tol-erable, which included myelosuppression, nausea, vomiting, and liver damage. Conclusion Gemcitabine combined with cisplatin is effective and safe in the treatment of NSCLC, especially in the initial treatment patients.

Objective Collecting the loosening periprosthetic interface-membrane, to discuss the mechanism of hip arthroplasty loosening. Methods The periprosthetic interface tissues of 29 hip arthroplasty revision cases from February 1995 to December 2003 were collected. The retrieved periprosthetic interface tissues were detected by immunohistochemistry. Some of them were studied by electronic microscope. Results (1)Transmission electronic microscope examination: the mitochondria swell. There were some substantia like lipid in the plasm of macrophages. Wear particles could be seen under scaning electronic microscope.(2)Immunohistochemistry: there were 22 IL-1? positive cases in cells of interface membrane. There were 29 IL-6 positive cases in cells of interface membrane. There were no positive results in TNF-? test. Conclusion (1)The wear particles of arthroplasty are important factors which cause biological reaction.(2)The interface membranes contain cytokine IL-1? and IL-6, which may play an important role in periprosthetic osteolysis and arthroplasty loosening.

Pathological puncture biopsy is the key to early diagnosis and treatment of thoracic tumours,and percutaneous puncture biopsy(PTNB)technology has been widely used in clinical practice.Common complications of PTNB include pneumothorax,air embolism and pulmonary hemorrhage.In order to optimize traditional PTNB,our center has developed a new percutaneous puncture diagnosis and ablation technology for lung lesions,which greatly reduces the occurrence of complications,increases the accuracy of pathological biopsy.At the same time,it can bridge target lesion ablation.This article describes the standard operating procedure for diagnosis and ablation techniques of filling operation assisted percutaneous transthoracic needle biopsy under rigid endoscopy with regular frequency controlled ventilation during general anesthesia.

The treatment of mediastinal tumor has always been a clinical difficulty due to its complex anatomical location and many important organs.Compared with traditional local treatment,endobronchial ultrasound guided laser multi-point ablation of mediastinal tumors has many advantages,including real-time monitoring of ablation range and effect,avoidance of damage to normal tissue and organs,few side effects and good tolerance.This article describes the standard operating procedure for endobronchial ultrasound guided laser multi-point ablation of mediastinal tumors.

Systemic application of effective antifungal drugs is the basic treatment for pulmonary mycosis,meanwhile,drug spraying under bronchoscope is one of the most important treatment options for tracheal,bronchial and pulmonary mycosis.Compared with bronchoscopic drug injection,indwelling guided drug injection cannula through nasal suspension with or without anchoring has more advantages in the treatment of pulmonary mycosis,including the ability to connect to a syringe pump for continuous and slow injection of drugs,which can avoid repeatedly performing bronchoscopy.This article describes the standard operating procedure of indwelling nasal cannula with or without anchoring for the treatment of pulmonary mycosis.

Recognizing upper airway obstruction and stenosis is critical to determine the subsequent treatment options in patients with obstructive sleep apnea(OSA).Drug-induced sleep endoscopy(DISE)is a 3D visual evaluation technology for the anatomical structure of the upper respiratory tract of OSA patients during"sleeping"state after being anesthetized.The dynamic situation of upper respiratory tract obstruction and collapse can be observed safely and quickly through endoscopy,which provides important reference for formulating surgical methods and positive airway pressure(PAP)intervention treatments.With the assistance of polysomnography(PSG),DISE plays an important role in optimizing individualized treatment plans for OSA.The present article introduces the technical operating points of PSG-assisted drug-induced sleep endoscopic positive airway pressure titration.