Debates over PBL have never stopped since its introduction to medical education in 1969 and are even becoming more heated.This paper expounds on the origin and definition of PBL,and then describes and analyzes the application of the clinical teaching in orthopedic surgery.

Objective To explore the CT features in CD_(117)-weak and CD_(117)-negative gastrointestinal stromal tumors(GIST).Methods The CD_(117)-weak and CD_(117)-negative Gist proved by pathologically and sur- gically in 13 cases were retrospectively analyzed.Results The tumor was located in the stomach in 6 cases, small intestine in 4 cases,colorectum in 2 cases,greater omentum in one case.The most common clinical manifestations were abdominal pain or discomfort in 6 cases,hematemesis or melena in 3 cases.Malignant tu- mors occurred in 8 cases.Benign tumors occurred in 5 cases.A soft tissue was identified in all 13 cases in CT examination.The CT examinations revealed cystic regions and bleeding in 5 cases.Calcification was not noted within the masses in all cases.The mean diameter of benign tumors was 3.4 cm?2.8 cm while that of malig- nant tumor was 7.5 cm?6.2 cm.All the cases underwent operation,the resection rate was 100%.After follow up from 6 months to 4 years in 10 cases,1 case died of tumor recurrence and metastasis,the others survived. Conclusion CD_(117)-weak and CD_(117)-negative Gist occurred more common in the stomach.CT is useful in lo- cation and differentiation of CD_(117)-weak and CD_(117)-negative gastric stromal tumors with regard to benign or malignant.Surgery is the main method for final diagnosis and treatment.

Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Cisplatin ; administration & dosage ; Cyclophosphamide ; administration & dosage ; Drug Therapy, Combination ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Fluorouracil ; administration & dosage ; Humans ; Injections, Intra-Arterial ; Lung Neoplasms ; drug therapy ; Male ; Middle Aged ; Mitomycin ; administration & dosage ; Phytotherapy

Coronary Artery Disease ; complications ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Myocardial Infarction ; etiology ; Spasm ; complications

Adenoma ; pathology ; Brain Neoplasms ; secondary ; Chromogranin A ; metabolism ; Diagnosis, Differential ; Follow-Up Studies ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Neoplasm Recurrence, Local ; Pituitary Neoplasms ; diagnosis ; metabolism ; pathology ; surgery ; Reoperation ; Synaptophysin ; metabolism ; Temporal Lobe ; pathology

Adult ; Breast Neoplasms ; metabolism ; pathology ; surgery ; Carcinoma, Squamous Cell ; metabolism ; pathology ; surgery ; Female ; Humans ; Keratin-5 ; metabolism ; Lymph Node Excision ; Lymphatic Metastasis ; Mastectomy, Radical ; methods ; Middle Aged ; Transcription Factors ; metabolism ; Tumor Suppressor Proteins ; metabolism

A temperature control system for quantitive polymerase chain reaction (PCR) is presented in the paper with both software and hardware configuration. The performance of the control system has been improved by optimizing the software and hardware design according to the system's properties. The control system has been proven to have a good repeatability and reliability as well as high control precision.
Equipment Design ; Microcomputers ; Polymerase Chain Reaction ; instrumentation ; Software ; Software Design ; Temperature

Adult ; Brain Neoplasms ; pathology ; Glioblastoma ; pathology ; Humans ; Male ; Pineal Gland ; pathology

Adolescent ; Adult ; Chronic Disease ; Dacryocystitis ; surgery ; Dacryocystorhinostomy ; methods ; Endoscopy ; Female ; Humans ; Male ; Microwaves ; therapeutic use ; Middle Aged ; Nasal Cavity ; surgery ; Young Adult

Objective To observe the formation of asymmetric dimethylarginine (ADMA)and the expression of dimethylarginine dimethylaminohydrolase 2 (DDAH-2) of human umbilical vein endothelial cells (HUVECs) stimulated by uric acid (UA), and to explore the role of ADMADDAH axis in the vascular endothelial dysfunction induced by uric acid. Methods HUVECs were cultured in M199 medium supplemented with 10% FBS. Cells were exposed to different concentrations of UA (0, 60, 120 mg/L) for 6 h and 24 h. Under different concentrations and times, the level of ADMA in cell suspension was detected by high performance liquid chromatography (HPLC) technique; the gene and protein expressions of DDAH-2 were detected by RT-PCR and Western blotting; the fluorescence intensity of intracellular 2',7'-dichlorofluorescein (DCF) which represented the productions of ROS was detected by the flow cytometry (FCM). The activity of DDAH-2 in HUVCEs which were exposed to different concentrations of UA (0, 60, 120mg/L) or UA (120 mg/L) +NAC (10 mmol/L) for 24 h was estimated by directly measuring the amount of ADMA metabolized by the enzyme and the role of NAC in the activity was studied.Results The expression of ADMA induced by urid acid was dose-depent and higher at 24 h than that at 6 h in the same dosage (all P＜0.05). The dosage and stimulation time of UA did not have any influence on the expression of intracellular DDAH-2 (all P＞0.05). When HUVECs exposed to UA (120 mg/L) for 24 h, the production of intracellular ROS was significantly increased while the activity of DDAH-2 was decreasesd (all P＜0.05) as compared to 60 mg/L stimulation. This effect could be inhibited by the intervention of anti-oxidant NAC. Conclusions The high UA stimulation on HUVECs can increase the expression of intracellular ROS and inhibit the activity of DDAH-2 which increases the concentration of ADMA by decreasing the degradation of ADMA as well as the formation of NO. DDAH-ADMA axis may participate in the vascular endothelial dysfunction induced by UA.