Baed on widely using PBL teaching mode in medical education the author made some exploration on the establishment of the academic evaluation of PBL for the principle for students' achievements.

Objective:To study the relative risk factor of bleeding again of patients with obscure gastrointestinal bleeding (OGIB) of negative result in capsule endoscopy(CE). Methods: 92 patients with OGIB whose extermination results of CE were negative were enrolled in the retrospective analysis, and they were divided into observation group(46 cases, with bleeding again) and control group(46 cases, without bleeding again). The data of casehistory of these patients were compared, respectively, and then these data were analyzed by using Logistic regression analysis.Results: The ratio of 50 years old or older than 50 years old and the number of abnormal blood coagulation of observation group were significantly higher than that of control group(x2=5.386,x2=14.331,P<0.05), respectively. And the number of taking Aspirin of observation group was significantly higher than that of control group, while the number of received special treatment of observation group was lower than that of control group(x2=7.180, x2=23.545,P<0.01). As the results of Logistic regression analysis, 50 years old or older than 50 years old, abnormal blood coagulation, taking Aspirin and non-receiving special treatment were the independent risk factors, respectively, for patients with negative results of CE.Conclusion: In the examination of CE, although the results of patients with OGIB were negative, they may blood again, and all of these factors including 50 years old or older than 50 years old, abnormal blood coagulation, taking Aspirin and non-receiving special treatment are the risk factors which can affect blooding again. These factors should be paid more attention.

Objective To explore the value of low-dose CT in assessment of neonatal pneumothorax.Methods Low-dose CT and chest radiographys were performed in 98 neonates with clinically suspected of pneumothorax.Results Pneumothorax was detected in 98 neonates by low-doseCT, compared with 84 neonates by chest radiography.The sensitivity of low-dose CT was higher than that of chest radiography (P =0.026<0.05). Conclusion Low-dose CT provides a reliable assessment of neonatal pneumothorax and a guide for clinical diagnosis and treatment.

As an emerging tumor therapy, high intensity focused ultrasound (HIFU) therapy has difficulty in controlling its dosage due to the complex human tissues. The dosage is related to the tumor such as its depth, size, characteristics and the tissue performances of its growth site. The existing cases are applied to establishing a repository with the above-mentioned parameters of the tumor analyzed. Then reasoning and self-learning are performed. So, the therapeutic dosage can be provided to the clinician when a new case occurs.

Aims To establish a UPLC-MS/MS meth-od for the determination of plasma concentration of scutellarein and its metabolite and to study their phar-macokinetics in rat plasma. Methods The analysis was achieved by BEH C18 column with a mobile phase composed of 0 . 1 % formic acid in acetonitrile and 0 . 1% aqueous formic acid using step gradient elution. A TQD tandem mass spectrometry equipped with electros-pray ionization source was used as detector and opera-ted by multiple reaction monitoring( MRM) positive ion mode. After intravenous injection of scutellarein, the concentrations of scutellarein and its major metabolite glucuronide scutellarin in rat plasma were determined at different time points. The pharmacokinetic parame-ters were calculated by DAS 2. 0 software. Results Good linearity was achieved for scutellarein, the ex-traction recovery was between 80 . 5 % to 90 . 5 %, the precisions and accuracy were good. The result showed the pharmacokinetic profiles of scutellarein and glucu-ronide scutellarin both fit to the two-compartment mod-el. Conclusion The above mentioned method is spe-cific, rapid, sensitive and suitable for the pharmacoki-netic studies of scutellarein and its metabolite.

Paget's disease of the breast is an uncommon disorder that accounts for 1% to 3% of all mammary tumors. The incidence of underlying carcinoma associated with Paget's disease has been reported in 82% to 100% of cases. The finding of underlying carcinoma reaches almost 100% when a palpable lump is also present. In this rare case, we described a patient presenting with Paget's disease but no palpable lump. However, we found 11 independent regions which were all invasive ductal carcinoma after the operation. Considering this patient, we should pay more attention to a multifocal and multicentric breast carcinoma associated with Paget's disease. Furthermore, we believe the mammography examination and a modified radical mastectomy are the most appropriate treatments for this population in clinical practice.

Aim To establish in vitro blood-brain barrier (BBB) model with characteristics of simulation of in vivo BBB by primi-tive co-culture of brain-microvessel endothelial cells (BMECs) with brain-microvessel pericytes (BMPC)and astrocytes (AS). Methods BMECs,BMPC and AS from SD rats were primitively isolated,purified and cultured,and then primitive culture cells were identified by cellular morphological and immunocytochemi-cal staining methods.Five types of in vitro BBB models were es-tablished by using Millicell culture insert (pore diameter 0.4μm)and their barrier functions were evaluated by detection of transendothelial electrical resistance (TEER),permeability of sodium fluorescent (Na-FLU ),expression of alkaline phospha-tase (AKP)and γ-glutamyl transpeptidase (γ-GT1 ),and simi-larity of permeation amount for positive drugs in vitro and in vivo BBB conditions.Results Primitive culture of BMECs presented typical pebbles-like structure,BMPC presented larger soma with branching property,AS presented slender synapse and shallower cytoplasm.Moreover,immunocytochemical staining results iden-tified primitive cells were targeted cells.TEER value for co-cul-ture of BMECs,BMPC and AS reached (478 ±25 )Ω· cm2 , permeability coefficients (Papp )value of Na-FLU was [(8.23 ± 0.78) ×10 -6 ]cm·s-1 ,expression of AKP and γ-GT1 were (6.90 ±0.27 )King unit · g-1 Pro and (4.39 ±0.32 )μg · g-1 Pro respectively.Moreover,good correlation could be found in Papp for positive controls in vitro and in vivo BBB models (R2=0.92).Conclusion The established in vitro BBB model by using primitive co-culture of BMECs with BMPC and AS posses-ses in vivo BBB properties in cell morphology,structures and barrier functions,and can be used as a powerful tool for studying physiology,pathology of BBB and screening candidate com-pounds.

Aim To establish a highly purified,active and prac-tical extract and primitive culture method for rat brain microvas-cular endothelial cells ( BMECs) for providing materials for con-struction in vitro blood-brain barrier ( BBB) model. Methods Cerebral cortex of 1-2 week SD rats was collected,and successive digestion with typeⅡcollagenase and collagenase/dispase, sieve filtration and then twice gradient centrifugation in 20% BSA and 44% Percoll condition were used to obtain brain microvascular section. After that brain microvascular section was seeded in cul-ture bottle and then primarily cultured. Inverted microscope and factor-VIII relative antigen immunostaining methods were used for cellular morphological observation and identification. Results BMECs climbed out the vessel segment and proliferated with ad-herence after 2 h in vitro culture,and they became typical peb-bles structure after further 3-4 d culture. Morever, factor-VIII relative antigen immunostaining identified that expression for the endothelial cells was positive,cytoplasm was brown and positive cells account for more than 99%. Conclusion Rat BMECs with high purity could be extracted and cultured by using the above methods,and it has great potential for construction in vitro BBB model and in depth studies on biological characteristics and func-tions of BMECs.

Objective To summarize and explore the clinical value of Mammotome technology in the diagnosis and treatment of breast neoplasms. Methods Nine hundred and eighty-seven breast neoplasms of 710patients were biopsied and excised with the aid of ultrasound-guided Mammotome system. The malignant neoplasms,according to the histological report,were radically removed during the operation without delay. All patients enrolled into the study were followed up closely on the complcations and satisfaction degree. Results All the operations except one were successful and got the sufficient specimen to perform the pathological examination,the biopsy achievement rate was 99. 8% . Both the sensitivity and specificity of the diagnosis were 100% in 16 breast tumors. Complete resection rate was 99%. The incision length was about 3 mm,showing good cosmetic outcome. Complcations were mild,mainly composed of haematoma and ecchymosis. The patients' general satisfactory rate was 93%. Conclusions This technique can help achieve biopsy of breast neplasm and excision of benign lesions at the same time with cosmetic result Further attention should be paid to reduce the lesion residue and hemorrhagic complications.