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

Murine norovirus (MNV) was first discovered in mice in 2003. MNV is a member of the genus Norovirus in the family Caliciviridae. It is one of the most important and prevalent pathogens of laboratory mice, and almost all mouse strains are susceptible to MNV infection. In this study, a MNV strain was isolated from the cecal contents of infected mice and identified by the cytopathic effect (CPE) assay, virus plaque assay, 50% tissue culture infectious dose (TCID50) assay, electron microscopy, indirect immunofluorescence assay (IFA) and nucleotide sequencing. On infection, the RAW264.7 cell line showed obvious cytopathic effects within 24 to 48 hours post-inoculation, as infected cells became rounded, bright and shrunken, with ultimate disintegration of the cell sheet. After the isolation of the MNV virus, the virus was plaque-purified in RAW264.7 cells. The TCID50 of the virus was 10(5.25/0.1 mL. Electron microscopic observations of the purified virus showed the presence of spherical and non-enveloped viral particles that were 30 to 35 nm in diameter. According to the identification results, the isolate was named as MNV Guangzhou/K162/09/CHN. Thereafter, five overlapping gene fragments that covered the entire open reading frame (ORF) were amplified by RT-PCR, and the 3'-untranslated region (UTR) and 5'-UTR were amplified using the 3'-rapid amplification of cDNA ends (RACE) and the 5'-RACE method, respectively. Each of the gene fragments were cloned and sequenced, and whole genome sequences of the strain were obtained by assembling the cDNA fragment sequences. The results showed that the length of the complete genome was 7 380 nucleotides (GenBank accession number: HQ317203). The comparison of nucleotide and deduced amino acid sequences of the isolate was performed against other MNV strains in the GenBank database. A phylogenetic tree based on VP1 nucleotide sequences was constructed using MEGA5.0 software. The homology of nucleotides between the MNV Guangzhou/K162/09/CHN strain and other MNV isolates ranged from 87.4% to 89.7%. Phylogenetic analysis showed that there was a close genetic relationship between the Guangzhou/K162/09/CHN strain and MNV strains isolated from Japan (S7-P2 and S7-PP3 isolates), Korea (K4 isolate), and Germany (Berlin/04/06/DE and Berlin/05/06/DE isolates). This is the first report of the isolation and identification of MNV in China, and the first report of the genetic analysis of its complete genome.
Animals ; Caliciviridae Infections ; veterinary ; virology ; Mice ; Molecular Sequence Data ; Norovirus ; classification ; genetics ; isolation & purification ; physiology ; Open Reading Frames ; Phylogeny ; Rodent Diseases ; virology ; Sequence Homology, Amino Acid ; Viral Proteins ; chemistry ; genetics

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

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