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.

Objective　 To investigate the relationships between the development of hypertrophic scar(HS) and apoptosis of fibroblast and endothelial cell, and to elucidate the influence of related modulating factors. 　Methods 　 TUNEL and immunohistochemistry staining techniques were employed to examine apoptosis of fibroblast and endothelial cell.The expression of ICE and Bcl-2 in hypertrophic scar of 61 cases of postburn patients undergoing plastic surgery with HS and in 20 other operative patients with non-hypertrophic scars(NHS)was also determined. 　Results 　 The positive apoptotic cell indices of fibroblast and vascular endothelial cells during the proliferative stage of HS were 6.60±4.43 and 8.90±6.01 respectively,while those during the mature stage were 25.60±5.70 and and 26.6±6.02, respectively.There existed evident differences in positive apoptotic cell indices between the same kind of cells (fibroblasts or vascular endothelial cells) during the two stages(P＜0.01). The ICE positive expression rate in proliferative stage was much lower than that in mature stage (P＜0.01),but the Bcl-2 positive expression rate in proliferative stage was obviously higher than that in mature stage(P＜0.01). 　Conclusion　 HS development might be related to the decrement of apoptotic fibroblasts and endothelial cells.ICE and Bcl-2 were possibly involved in the modulation of fibroblast and endothelial cell apoptosis in HS.

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.

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.