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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.
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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.
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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.
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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.
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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.
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There is increasing evidence that dermis contains adult multipotent stem cells. To investigate the effects of dermis-derived multipotent cells on wound healing, we transplanted a clonal population of dermis-derived multipotent cells (termed as DMCs) by topical and systemic application into the skin wound of rats with simple wounds and rats with combined wound and radiation injury. Our results suggest that both topical and systemic transplantation of DMCs accelerate the healing process in rats with a simple wound; the promoting effect by topical transplantation occurs earlier than systemic transplantation. However, systemic transplantation of DMCs promotes the healing process in irradiated rats, while topical transplantation of DMCs fails. Further studies on the mechanisms of DMCs to promote wound healing indicate that the supernatant of DMCs could promote the proliferation of fibroblasts and epidermal cells; DMCs expressed transcripts of a series of cytokines and extracellular matrix molecules, including VEGF, PDGF, HGF, TGF-beta, ICAM-1, VCAM-1, and Fibronectin, which were closely related to the wound healing by DNA microarray analysis. The implanted DMCs can engraft into recipient skin wounded tissues after transplantation by the FISH analysis with Y-chromosome-specific probe. Systemic transplantation of DMCs also promotes the recovery of peripheral white blood cells in irradiated rats. These results demonstrate the different effects of DMCs on wound healing in non-irradiated and irradiated rats and illustrate the importance of optimizing wound healing via the topical or systemic transplantation of stem cells.
Subject(s)
Multipotent Stem Cells/transplantation , Skin/cytology , Wound Healing , Animals , Cell Division , Cells, Cultured , Cytokines/genetics , Female , In Situ Hybridization, Fluorescence , Lymphocyte Activation , Rats , Rats, WistarABSTRACT
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.
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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.
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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
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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.
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Objective To compare the irradiation-protective and inter-synergestic effects of E838,WR-2721, Rubia cordifolia, cystamin e hydrochloride and ethinyl estradiol on radiation and combined radiation-burn injury. Methods Above-mentioned drugs were given to the mice i ntraperitoneally, or intragastrcally, then, the mortality and the average surviv al d for 30 d were observed before and after the administration of the drug s. Results ①When drugs were before injury , the survival rate and the average survival d of the radiation and combined radiation-burn injured mice were increased obviously with the best effect in E838 and WR-2721. ②When drugs were given after injury, E838 and R. cordifolia also kept the effect. ③Combined appling WR-2721（pre) and E838（post）displayed a significant syner gistic reaction. Conclusion E838 and WR-2721 are more e ffective than the others in the prevention of radiation.
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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.
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Besides hematopoietic stem cells, bone marrow also contains another type of stem cells called mesenchymal stem cells (MSCs). With different induced conditions, MSCs have the ability to differentiate into a variety of nonhematopoietic tissue cells, including osteoblasts, chondroblast, adipocytes, myoblasts, astrocytes, and so on. MSCs can be readily obtained from bone marrow by their adhesion to plastic and expansion in culture. Also they can be genetically engineered by transduced target genes. MSCs may be the farget cells for both cell therapy and gene therapy for diseases derived from many different nonhematopoietic tissues.
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AIM: To study the effect of mesenchymal stem cells (MSCs) infusion on hematopoietic recovery after peripheral blood stem cell transplantation in mice. METHODS: BALB/c mice conditioned by high dose chemotherapy/radiotherapy were infused with 10 6 peripheral blood mononuclear cells (PBMC) mobilized by granulocyte colony-stimulating factor (PBSCT group), 10 4 MSCs culture-expanded in vitro and 10 6 PBMC(experimental group 1), 10 6 MSCs and 10 6 PBMC(experimental gruop 2). Survival rate within 4 weeks, white blood cell count, bone marrow nucleated cells (BMNC), granulocyte-macrophage colony forming unit(GM-CFU) and fibroblast colony forming unit (F-CFU) were examined. RESULTS: Survival rate, BMNC, GM-CFU, F-CFU were significantly higher in experimental group 2 than that in PBSCT group ( P
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Healthy adult mice were inflicted with combined injury of gamma radiation(4 Gy from a 60Co source) and burns (15% TBSA third degree).From 6 daysprior to to 8 days after the injury.TEP-87,which consists of zinc,copper andiron in the dosage appropriate to the physiological requirement as well as lycine,vitemins B1,B2,C and D,folic acid and malt,was administered.It was found that the protective effect of this preparation on the marrow cells of the myeloblastic line of the animals inflicted with either simple radiation injury or combined injury of radiation and burns was obvious even on the first day after injury.Meanwhile,the total number of white blood cells was maintained at a relatively high level.On the 8th day after injury,accelerated rate of recovery of the mice was observed.No favorable effect could be revealed on the uncleated cells of the bone marrow,or on the positive rate of esterase which is a nonspecific marker of T-lymphocytes.The protective effects of TEP-87 on the hemopoietic function of the mice with combined radiation-burn injury might be due to the direct stimulation of zinc,copper and iron on the proliferation of the hemopoietic stem cells.
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Mice inflicted with severe combined radiation-burn injury were treated with WR-2721 and allogenic fetal liver cell transplantation. The mortality of the treated group was significantly lower and the mean survival time longer than the control. When compared w'th those of the control, the changes of the per pheral white count, the count of the nucletaed cells of the bone marrow, and the bone marrow CFU-C of the treated group were less marked and returned to normal more rap:dly. The changes of the peripheral T-lymphocyte count was not so marked as that of the bone marrow CFU-C.The combined therapeutic efficacy of WR-2721 and fetal cell transplantation was more prominant in treating the combined radiation and burn injury than either of the two agents used alone.
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Rats were subjected to 15% body surface area third degree burns combined with 2 , 4 , 6 , and 8 Gy irradiation respectively. 48 hours after injury, the DNA and RNA contents of the bone marrow, lymph nodes, spleen and peripheral blood were found to have marked reduction, which became more marked when the dosage of the radiation was increased. Furthermore, it was found that the DNA content decreased more rapidly than the RNA content and the chnage of RNA was more marked in the hemopoietic tissues than in the peripheral blood. Nucleic acid reduction occurred more severely following 2 Gy irradiation than following 15% BSA third degree burns. After the combined iujury of 8 Gy irradiation and burns, th? reduction of nucleic acids in all the above-mentioned tissues exceeded 50%.The mechanism of the changes of necleic acids in the hemopoietic tissues after combined injury of radiation and burns was discussed. Radiation played a more important role than burns in resulting in the reduction but the synergistic effect of burns could not be neglected and could be clearly demonstrated.
