Objective To explore the teaching effect ofOrgan-system-based curriculum in-tegrated model on clinical graduation field work. Method 150 clinical medical undergraduates of Grade 2009 from Shenyang Medical College selected, were randomly divided into the experimental group (75 persons) and the control group (75 persons). The experimental group adopted the means of the Organ-system-based curriculum integrated model, namely practicing according to human organ-system and the control group accepted the traditional pattern of discipline centered practice during the clinical graduation internship. The two groups of students carried out questionnaire survey and comprehend examinations when the practice ended, and then statistics analysis (the chi square test, t test) was done by the SPSS 19.0 software between the two groups in order to explore the teaching effect. Result The students' satisfaction degree from six aspects of the questionnaire survey showed in the experimental group was significantly higher than that in the control group (the degree of recognition of practicing pattern: χ2=11.437, P=0.003; the architectonic integrality: χ2=9.881, P=0.007; the im-provement of the autonomic learning ability χ2=9.643, P=0.008; the teaching method and means: χ2=11.006, P=0.004; motivating learning interest: χ2=13.550, P=0.001; increasing the ability of clinical thinking: χ2=13.309, P=0.001), and the average test scores of students from three parts of examination results showed by comprehend examinations (speculative knowledge examination: t=2.768, P=0.006;technical skill examination: t=2.212, P=0.029; clinical capability examination: t=5.015, P=0.000) in the experimental group was obviously higher than that in the control group and the difference was sig-nificant. Conclusion Organ-system-based curriculum integrated model on clinical graduation in-ternship is generally approved by the students, which has significantly improved the students' clinical thinking ability, and the quality of graduation internship teaching.

Aiming at the existing problems in the teaching hospital,teachers and practical students during clinical practice teaching,we explored actively in talent training and teaching base construction and promoted the improvement of clinical practice ability for medical students.

BACKGROUND:Studies have found that smal intestinal submucosa that is directly implanted into the lesion cannoteffectively promote celgrowth and differentiationin vivoandin vitro, because of its smal pore size and poor permeability.
OBJECTIVE:To establish the smal intestinal submucosa sponge and to explore its morphological characteristics.
METHODS:Porcinesmall intestinal submucosa was prepared by physiochemical method. Thenthe small intestinal submucosa with the mass fraction of 1%, 2%, 3% and 4% was cross-linked by 50, 100 and150 mmol/L 1-ehyl-3-(3-dimethylaminopropyl) carbodimide hydrochloride, respectively, so as to obtain smal intestinal submucosa sponge, whose morphology was detected by lighting and scanning electron microscope. In the meanwhile, smal intestinal submucosa as control group, and smal intestinal submucosa sponge as test groupwere intramuscularly implanted into the back of rats,respectively. At 1, 2 and 3 weeks after implantation, histological changes andimplantdegradation were observed by hematoxylin-eosin staining.
RESULTS AND CONCLUSION:The smal intestinal submucosa sponge, which was prepared by the smal intestinal submucosa with the mass fraction of 1% and 100 mmol/L cross-linking agent, had elastic and close space structure, uniform pore size and regular structure, so it was selected as the implant into themuscle.At 1 week after implantation, in the test group,the mesh sponge had the complete structure withfew neutrophils, lymphocytes and giant cel reaction, andsoft tissue hyperplasia and migration surrounding the implant appeared;in the control group,there were numerous inflammatory cels, and wound adhesion and little migration of surrounding tissues could be found.At 3 weeks, inflammatory cels mostly disappeared, and fibroblast-like cels and vascular components appeared, with thinner and regular colagen fiber bundles, and connective tissue-like structures could be found. In contrast, the control group stil had numerous inflammatory cels and few colagen fibers. In conclusion, smal intestinal submucosa sponge isapotential material used asthe tissue-engineered skinscaffold.

Tumor microenvironment (TME) plays a key role in the development and progression of tumors, such as pro?moting local drug resistance, immune escape, and distal metastasis. According to the TME of different individuals, accurate evaluation and selection of clinical medication can effectively control the malignant transformation of carcinoma in situ and metastatic cancer. At present, the main method to treat cancer is chemotherapy, TME can regulate the reaction of the tumor cells to the standard chemotherapy and target drug therapy, so the combination of the targeted TME therapy and chemothera?py will achieve better clinical efficacy. In this review, we summarized the mechanisms of TME in breast cancer, including ex?tracellular matrix, carcinoma-associated fibroblasts, carcinoma-associated macrophages, regulatory T cells and bone marrow mesenchymal stem cells, which providing a theoretical basis for the development of TME targeted therapy.