SARS is a crisis, which is not only a baptism to the Chinese nation,is but also a test to our health's regulatory regime, medical resource,crisis prevention technical level,et al.The author discussed preventive medicine's three Characteristics:gobality,holography,timely and its staff's moral responsibility.

Embryonic stem cells detached from inner cell mass(ICM),can maintain self-renewal undifferentiation status and differentiate into almost every type of cells.Lots of genes take part in the regulation of embryonic stem cell's proliferation and differen-tiation.In this paper,we reviewed the related genes about embryonic stem cell's proliferation and differentiation,meantime draw off questions which need to be further illuminated.

Objective:To analyze the relationships between baseline percentage of pulmonary perfusion defect scores (PPDs%) and residual pulmonary hypertension after pulmonary endarterectomy in chronic thromboembolic pulmonary hypertension (CTEPH) patients.Methods:A total of 37 CTEPH patients (21 males, 16 females, age (50±12) years) who had pre- and post-pulmonary endarterectomy ventilation/perfusion (V/Q) scans from January 2016 to January 2019 at Fuwai Hospital were retrospectively collected. Residual pulmonary hypertension was defined as post-surgery mean pulmonary artery pressure (mPAP) higher than 30 mmHg (1 mmHg=0.133 kPa). Semi-quantitative index PPDs% was calculated to represent the extent of impaired perfusion in the whole lung. Pre- and post-surgery pulmonary hemodynamic parameters including pulmonary arterial pressure and resistance and lung perfusion were compared. Factors that may be related residual pulmonary hypertension were analyzed using logistic regression analysis. Paired t test and independent-sample t test were also used. Results:Pulmonary endarterectomy significantly decreased mPAP ((50.22±11.72) vs (26.41±10.61) mmHg; t=12.599, P<0.001) and pulmonary vascular resistance((10.06±5.48) vs (2.89±1.58) Wood unit; t=8.086, P<0.001). The number of defected lung segments (13.79±2.11 vs 5.52±2.82; t=11.593, P<0.001) was significantly reduced. Patients who had residual pulmonary hypertension ( n=11) exhibited significantly higher PPDs% before the surgery compared to those who were without residual pulmonary hypertension ( n=26; (57.48±5.88)% vs (47.77±11.09)%; t=-3.458, P=0.002). Baseline PPDs% was an independent factor for predicting residual pulmonary hypertension after pulmonary endarterectomy (odds ratio ( OR)=1.106, 95% CI: 1.006-1.216, P=0.036). Conclusions:Pulmonary V/Q scan can assess the therapeutic effects of pulmonary endarterectomy. Extent of impaired lung perfusion assessed by V/Q scan is the influencing factor for post-surgery residual pulmonary hypertension.

Objective To establish a model of full-thickness avascular meniscal defect to assess outcome of bone-marrow mesenchymal stem cells (BMSCs) modified with human insulin-like growth factor Ⅰ (hIGF-Ⅰ) gene and compounded with injectable calcium alginate gel in repair of meniscal defect.Methods Models of full-thickness defect were created in the anterior comer of meniscus in goats,an area lacking of blood supply.The trial categorized the models to four groups:gene-ehanced tissue engineering (GETE) group (hIGF-Ⅰ transfected BMSCs were mixed with calcium alginate gel),BMSCs group (BMSCs were mixed with calcium alginate gel),empty group (calcium alginate gel was used alone) and control group (the defect was excluded from repair).Macroscopy was done at 4,8,and 16 weeks after operation.Variation of repair tissue was observed by light and scanning electric microscopy and aggrecan in repair tissue was determined as well.Results Meniscal defect was on the mend at 4-16 weeks after operation in GETE group,with the defect area being thoroughly filled with the white,elastic and tight repair tissue similar to normal meniscal tissue.Macroscopic examination showed a better result in GETE group than that in other groups.Light microscopy showed that repair tissue which was mainly fibrochondrocytes was arranged in line with calcium alginate fibers and that space between the fibers was mostly crammed with the matrix secreted by those cells.At the same time,those cells were tightly arranged and the matrix secreted by those cells was equally distributed according to light microscopy.Electroscopy demonstrated neat and tight arrangement of fibers and tight extracellular matrix in fiber space in GETE group.Aggrecan concentration in GETE group was relatively higher than in other groups,but still had difference from the normal meniscus.Conclusion hIGF-Ⅰ gene-transfected BMSCs combined with injectable calcium alginate gel can improve the effect in repair of full-thickness meniscal defect.

Objective:To explore the role of CXCR2 in the invasion and metastasis of head and neck squamous cell carcinoma (HNSCC).Methods:The expression of CXCR2 in HNSCC tissues of 105 cases was detected by immunohistochemical staining,the correlation between CXCR2 expression and cervical lymph node metastases of HNSCC was analysed.Then,3 stable HNSCC cell lines with CXCR2 interference were established,the effects of CXCR2 silencing on cell migration and invasion were observed by in vitro tests.Results:CXCR2 was positively expressed in 51.43% of HNSCC specimens and was statistically associated with the cervical lymph node metastases of HNSCC.CXCR2 silencing markedly inhibited the migration and invasion of HNSCC cells in vitro.Conclu-sion:CXCR2 may play a key role in the invasion and metastases of HNSCC.

Aim To study the hypnotic effect of five alkaloids extracted from Rhizoma Coptidis (berberine , coptisine,palmatine,epiberberine,jatrorrhizine )in mice,and preliminarily explore its underlying mecha-nism.Methods The experiments of locomotor activity and hypnosis induced by suprathreshold and subthresh-old doses of pentobarbital sodium were used to evaluate the effect of drugs on sleep behavior in mice.Then, HPLC-FLD was used to detect the contents of NE,DA and 5-HT on PCPA mice model.Results Compared with control group,berberine and coptisine notably in-hibited spontaneous activity in behavioral experiments (P <0.05),and increased the sleeping percentage of mice under subthreshold dose of pentobarbital sodium. Berberine and coptisine shortened the period of sleep latency,and prolonged the sustained period of sleeping at suprathreshold dose in mice (P <0.05 or P <0.01 ).Other alkaloids had no significant differences in sleep latency and period of sleep observed in this current experiment.Compared with PCPA mice model group,berberine and coptisine remarkably increased the contents of NE and 5-HT (P <0.01 ),but they had no effects on DA.Conclusions Berberine and coptisine may play a sedative and hypnotic role in PC-PA mice by increasing contents of 5-HT and NE in hy-pothalamus,and the sedative and hypnotic effects of berberine are stronger than those of coptisine.Other alkaloids have no effects on sleeping in mice.

Purpose: To understand the function of catabolism degradation in the formation and deterioration of hypertrophic scar. Method: The study was carried out clinically, on animal model and cultured fibroblast cell. The investigation was conducted with naked eye, microscope, situ hybridization, dot blot hybridization, TUNEL and immunohistochemistry. Result:①The hypertrophic scar grew up very slow but might be eliminated 1/3 to 2/3 within one month with different chemical intervention. ②The synthesis of collagen in hypertrophic scar increased a little, but it's degradation decreased much more. ③The collagenase MMP-1 could destroy the collagen after local injection into the hypertrophic scar, it was proved by light and electromicroscope. ④The expression of MMP-1 Mrna increased a little in hypertrophic scar, but MMP-1 in the scar really decreased in quantity and activity. ⑤Ch-4-S increased significantly in hypertrophic scar, it wrapped up the collagen fibrils and blocked its contact with and avoided its catabolism by MMP-1.TIMP increased in hypertrophic scar and depressed the activity of MMP-1. ⑦The expression of TGF-β increased significantly. It positively related with the expression of TIMP and negatively related with the apototic phenomena in hypertrophic scar. The fibroblast in hypertrophic scar was rich and active, but its proliferation was not elevated and apotosis was delayed. Conclusion: ①The delay of apotosis of fibroblast, the wrapping of collagen by Ch-4-S, the reduction of collagenase in quantity and activity together made the abolition of collagen decreased and might be primary for the formation of hypertrophic scar. ②Accelerating the apotosis of fibroblast and catabolism of collagen might be an easy and rapid way for prevention and treatment of hypertrophic scar.

BACKGROUND: Hypertrophic scar results from imbalance between local collagen synthesis and degradation and abnormal aggregation of collagen after burn and trauma.OBJECTIVE: To observe the effects of collagenase on collagen degradation in nude mice with graft of hypertrophic scar and its therapeutic effects on hyertrophic scar.DESIGN: Controlled experiment was designed.SETTING: Department of Rehabilitation and Physical Therapy,Southwest Hospital, Third Military Medical University of Chinese PLA MATERIALS: The experiment was performed in Experimental Center of the Third Military Medical University of Chinese PLA from July 1995 to April 1997, in which, 10 specimens of hypertrophic scar were employed, collected from the removed hypertrophic scars in Department of Plastic Surgery.All of patients were in the known before the operation. Experimental animals were 15 BACB/C nude mice, of which, 8 mice were male and 7 mice female.Totally 15 mice were grafted with hypertrophic scar tissue, 10 mice of which were survived after once graft; with second graft in the rest mice, 2 mice were survived and 3 mice were dead. The survival nude mice were randomized into experimental group and the control, 6 mice in each one.METHODS: The removed hypertrophic scars in plastic operation were grafted in the wound on the dorsum of nude mice to establish graft model of hypertrophic scar. In experimental group, 1% collagenase was injected locally in scar tissue; in the control group, collagease solvent was injected locally, once a week, for 4 weeks totally. After treatment, the materials were collected for macrogcopic observation and observation and analysis with optic and electronic microscopes.scar tissue before and after treatment.RESULTS: Twelve nude mice were survived after scar graft and all of them entered result analysis, 6 mice of which were in experimental group was smaller in size, thinner in thickness and softer in quality compared staining, Van Gieson's collagenous fiber staining and compound staining on slices, it was displayed that in experimental group, dermal layer became thin, collagenous fiber was unclear in structure and disperse in arrangement, but in the control, the dermal layer of scar tissue was hypertrophic microscopic observation, in experimental group, collagenous fibers were destroyed and unclear in structure, but in the control, collagenous fibers were disturbed in arrangement with distinct strips and clear structure.CONCLUSION: Collagenase degrades collagen of hypertrophic scar,lessens and softens scar, suggesting that local injection of collagease is probably a good therapy for hypertrophic scar.

Objective To analyze the feature and cause of stumps of amputees after Wenchuan earthquake,and study the effects of rehabilitation treatment for stumps.Methods Fifty-two cases with stump limbs post-amputation were evaluated,including stump skin status,stump shape,stump length,stump swelling,range of motion (ROM)of joint and strength of stump,and were treated with physical therapy,stump moulding and kinesiotherapy.Results The incidences of stump ulcer,stump swelling,conical stump,short stump and limitation of ROM of joint in all 52 cases were 76%,73%,34%,40%and 42%respectively.After rehabilitation treatment stump ulcers healed,stump swelling eliminated;stump shape,ROM of joint and muscle strength improved obviously.All poor stumps could be fit with the prosthetic limb and get good function.Conclusion The incidences of poor stump limb post·amputation after earthquake were high.Rehabilitation treatment can improve the stump condition.Early comprehensive rehabilitative intervention after amputation is important for fitting the prosthetic limb tO the stump.