When entering the clinical teaching phase,the last step before graduation and assignation,medical students are given more chances to contact with the society.This is an important period that the educators should care more about and communicate more with the students in order to foster their career mentality.Our suggestions are as follows,1.Emphasizing the clinical ability.The basic clinical skills are the premise and guarantee that a medical student is able to diagnose and cure,and also the main content of quality education and evaluation for medical students,2.Emphasizing the formation of the research-type learning habit and the innovative thinking modes.The cultivation of the research-type learning ability is a symbol of innovative talent,as well as an essential quality.An innovative thinking training consists of different thinking,converse-thinking,role-changing thinking,divergent thinking and critical thinking.3.Must correctly deal with the relationships between having a clinical training or preparing for the postgraduate entrance examination and getting a job.The educators should help the student form virtues of professional dedication,diligence and positive learning attitudes,strengthen their sense of social responsibility and obligation,and establish correct world outlook,outlook on life and values.4.Must enhance the nurturance of medical students' professional ethics.In the clinical practice,the students' behavior must be regulated.What's more,they should learn to be a qualified doctor who respect,be responsible for and care for the patients.

To enhance innovative education in students is the primary task of education in universities and is a way to show the subjectiveness and creativeness of students.It is important to emphasize the combination of knowledge,ability and essential-qualities in order to elevate general ability and quality of the students.Innovative education includes renewing education concept,establishing a teacher team with innovative ideas,integrating the comprehensive course system,reforming teaching technique,updating evaluating system of teaching effect and modifying mechanisms of teaching administration.The renewal of education concept will pave the way for implementing innovative education in practice.

The teaching design of courses is how to conduct teaching.It should combine contemporary concept of education administration,current teaching techniques and educational practices.Teaching design facilitate the swift of teaching from experiental to scientific,change the relationship between teachers and students in teaching-learning activity,and bring the integrative function of teaching system into play.This paper describes the design of discipline teaching,theoretical teaching in class,discussion teaching,teaching of enhancing hand-on ability and evaluation of teaching effect.

BACKGROUND: Bone marrow mesenchymal stem cells (BMMSCs) can be induced differentiating into osteoblasts and chondroblasts, DNA methylate depressant 5-azacytidine can induce BMMSCs expressing myogenic regulating factors: Myf5 and myopoietin, which involving in the differentiation of BMMSCs into myoblasts.OBJECTIVE: Muscular traumatic fluid containing the highest protein content was screened out and co-cultured with BMMSCs,in order to explore the inductive effect on the proliferation and myogeneis of BMMSCs.DESIGN : Standardized comparative study.SETTING .:At State Key Laboratory of Trauma, Bums and Combined Injury,Institute of Combined Injury, Medical College of Preventive Medicine, Third Military Medical University of Chinese PLA.MATERIALS: Muscular traumatic model was established on 18 Balb/C pure rats for the extraction of muscular traumatic fluid, the inductive effect of the fluid on BMMSC was then compared with 5-azacytidine.METHODS:This study was carried out at State Key Laboratory of Trauma,Burns and Combined Injury, Institute of Combined Injury, College of Preventive Medicine, Third Military Medical University of Chinese PLA from April 2001 and September 2003. Bradford colorimetric was used to detect the protein content in the muscular traumatic fluid, and the fluid with the highest protein was used to co-culture with BMMSC, whose effect on the proliferation of BMMSC was measured with MTT methods at day 0, 3, 6, 9, 12, 15.RT-PCR technique was used to detect the expression of myopoietin at day 6,with its myogenic effect compared with that of 5-azacytidine.fluid on BMMSC.eration of BMMSC: the proloferative activity of BMMSC in traumatic fluid genic effect of traumatic fluid on BMMSC: myopoietin could not be found expressed in traumatic fluid group, but strongly expressed in 5-azacytidine group.CONCLUSION: Muscular traumatic fluid can promote the proliferation of BMMSC, but has no myogenic effect.

BACKGROUND: Abnormal hematopoietic microenvironment is an important factor causing dyshematopoiesis. However, no consensus has been reached on the sensitivity of hematopoietic stromal cells to irradiation.OBJECTIVE: To observe the changes of marrow stromal cells (MSCs) cycle and DNA content during the early stage of irradiation damage in mice, so as to further understand dyshematopoiesis due to radiation and provide scientific basis to avoid deleterious factors in hematopoietic environment.DESIGN: Completely randomized grouping and randomized controlled study based on the experimental animals.SETTING: Central laboratory of altitude military affairs medical department and altitude research institute of preventive medicine department, a military medical university of Chinese PLA.MATERIALS: This study was carried out at the Experimental Animal Center of Third Military Medical University between October 2002 and April 2003. A total of 60 healthy male Kunming mice were randomly divided into irradiation damage group and healthy control group, each having 30 mice.METHODS: The 30 mice in irradiation damage group were exposed to 60Co-γ of irradiation at a dose rate of 1.27 Gy/minutes within a distance of 4 m. Then the mice' marrow cells were harvested at day 3 and day 7 after irradiation, and were cultured in vitro for 14 days and 21 days for observation. Meanwhile the other 30 healthy mice unexposed to irradiation were considered as normal controls.MAIN OUTCOME MEASURES: Post-radiation number of MSCs colonies,cell cycle and DNA content.RESULTS: Although MSCs could grow and be adhered to walls after being exposed to irradiation of 5.0 Gy/s, the number of MSCs colonies was found significantly decreased compared to that of rnormal control group( P < 0.01 ).The colony number of the MSCs irradiated for 7 days obviously increased than that of MSCs irradiated for 3 days; however, MSCs recovered slowly and resulted in prolonged culture time, indicating the inhibited proliferation of MSCs due to irradiation damage. Results of flow cytometry showed that cells in G2+ M phase(2.60±0.41, 4.20±1.27) and DNA content (58.40±0.79,61.17 ± 1.35) in irradiation groups after 3-day and 7-day irradiation were obviously lower than those of normal control group(12.60 ±0. 75, 78.57±0. 83)(P <0.05-0.01).CONCLUSION: MSCs have relatively high sensitivity to irradiation damage and longer persisting period.

Objective To investigate the effect of half-body ionizing radiation on the concentration of MDA, SOD in serum and the spleen index, CFU-S and the protective function of supplementary taurine (Tau) in half-body ionizing irradiated mice. Methods Kunming mice were randomly divided into 6 groups: normal control, total-body irradiation (TBI), total-body irradiation+Tau, left-half-body irradiation, half-body irradiation+Tau, and total-body shielding irradiation. The relevant indexes such as the spleen index, spleen colony forming units (CFU-S) were observed. The ionizing radiation was performed under ~ 60 Co ? ray with absorbed dose 8.0 Gy, dose rate 68.46 cGy/min. Taurine at dose of 500 mg/kg was injected intraperitoneally twice a day before irradiation, once 30 min before irradiation, and once 6 h after irradiation. Results In TBI group, the spleen index and CFU-S were decreased remarkably, MDA increased and SOD reduced in serum. The hematopoietic function of spleen was not improved by supplementary taurine (P

Objective To further determine their possible synergistic effect on accelerating wound healing, adenovirus vector containing recombinant human hPDGF-A and hBD2 genes was constructed and the expression of exogenous genes in transformed mesenchymal stem cells derived from rat bone marrow was observed. Methods By putting IRES in the middle of hPDGF-A and hBD2, these two genes were expected to be expressed individually. The shuttle vector was named as pAdTrack-hPDGF-A-IRES2-hBD2, which homologously recombinated with Adeasy-1 in BJ5183 cells and formed the mammalian expression vector pAdeasy-hPDGF-A-IRES2-hBD2. Furthermore, the recombinant vector was packaged in 293 cells into infectious recombinant adenovirus, which were used to infect BMSCs. The expression of hPDGF-A and hBD2 in BMSCs was detected by RT-PCR. Results We successfully constructed recombinant adenovirus vector that simultaneously expressed hPDGF-A and hBD2. The expressions of hPDGF-A and hBD2 were confirmed by RT-PCR on transformed BMSCs. Conclusion The established BMSCs that overexpressed hPDGF-A and hBD2 provide a new strategy of combining cell therapy and gene therapy to promote wound healing, especially the chronic one.

Objective To investigate the effects of Calpain inhibitor Ⅰ on glucocorticoid receptor and its transcript activation ability. Methods Raw-264.7 cells were treated respectively with Calpain inhibitor Ⅰ and dexamethasone or both for 24 h. The changes of glucocorticoid receptor were observed. COS-7 cells were co-transfected with PRsh-GR? and pMAMneo-CAT vectors, and then the effects of Calpain inhibitor Ⅰ on glucocorticoid receptor and its transcript activation ability were detected. Results The glucocorticoid receptors was decreased after Raw-264.7 cells were treated with dexamethasone for 24 h. Calpain inhibitor Ⅰ could inhibit this effect to some extent. Co-transfection experiment revealed that Calpain inhibitor Ⅰ could also promote glucocorticoid receptor transcript activation ability. Conclusion Calpain inhibitor Ⅰ can inhibit the down-regulation of dexamethasone on glucocorticoid receptor, but promote glucocorticoid receptor transcript activation ability.

Objective To explore the effects of survivin on radiation injury and its relation to caspase 9/6,3 activity. Methods ① IEC 6 cells were treated under hypoxic environment for 8 h and followed by reoxygenation for 24 and 48 h, and then the expression of survivin was identified by Western blotting. ② After treatment with 35 Gy 60 Co , the apoptosis rate in different groups was detected with FACS and the caspase 9/6,3 activity was tested using the caspase 9/6,3 assay kit. Results Hypoxic preconditioning could induce the expression of survivin in IEC 6 cells and survivin could decrease the caspase 3 activity, resulting in reduced apoptosis rate induced by radiation. Conclusion Survivin induced by hypoxic preconditioning can inhibit the apoptosis induced by radiation by reducing the caspase 3 activity.

Objective　To observe some biological features of bone marrow mesenchymal stem cells and explore the best conditions for isolatin g and culturing in vitro. Methods　Common cell culture techn ique, light and electron microscopy were used to study the effects of the growth , proliferation, morphology of the bone marrow mesenchymal stem cells in differe nt adherent time, concentration of serum and cell density. Results　The best culture condition in vitro for growth was 4-24 hours adherent time, 5%-10% fetal bovine serum, (4-8)×104/ml cell density. The cells were sp indle in shape and had a strong ability of proliferation. The time for cell duplication was 3 to 4 days. The cells showed the characteristics of stem cell s in electron microscope. Conclusion　The best condition for iso lation and culture of bone marrow mesemchymal stem cells was successfully establ ished and some biological features were obserred. It found a base for further in vestigation and using of mesenchymal stem cells.