This paper analyzed the current status of clinical research at Peking University, which was compared with that of a number of international and domestic universities. Suggestions were put forward in accordance with the current domestic problems in clinical research.

Objective To investigate the incidence of healthcare-associated infection(HAI)in hospitalized patients≥65 years at a hospital in Hunan Province.Methods Data of patients with HAI in this hospital in 201 1—2013 were classified and analyzed statistically.Results A total of 47 626 patients were investigated,1 068 cases of HAI oc-curred,all cases were single site infection,incidence and case rate of HAI were both 2.24% ,incidence in patients aged <65 years (2-65 years old)was 0.98% (234/23 998),and ≥65 years was 3.53% (834/23 628),difference was significant between two groups (χ2= 354.44,P<0.001). HAI rate in patients aged <65,65~,70~,75~, 80~,85~,and ≥90 years was 0.98% ,1.59% ,1.28% ,2.77% ,5.20% ,6.93% ,and 9.43% respectively. The major infection site was lower respiratory tract (59.95% ,n= 500),the main detected pathogens were Pseudo-monasaeruginosa (19.43% )and Escherichia coil (18.72% ).Conclusion The incidence of HAI in the elderly patients increased with age increasing,the main infection site is lower respiratory tract.

Objective To investigate the risk of heart failure to the mother and the neonate.Methods The clinical data of 30 pregnant womem with heart failure from January 1993 to December 2010 from Capital Medical University Tongren Hospital was retrospectively analyzed.Results Of the 30 patients,there were 12 affected with congenital heart disease (40％) ; 9 with rheumatic heart disease 30％,7 with heart failure in pregnancy-induced hypertension 23％.Heart failure appeared at the average of (34.20 ± 4.25) weeks in pregnancy.The average terminal time of pregnancy was (34.84 ± 2.17) weeks.The rate of early birth was 73.33％.The average birth weight was (2011 ±568) g,with 7 babies less than 2000 g.No death occurred in both new the mother and the neonate.Condusion The main causes of heart failure in pregnancy are congenital and rheumatic heart disease and pregnancy-induced hypertension.For those heart failure occurs before 30 weeks,it is the first selection that pregnancy shoud be terminated; For those occur after 30 weeks,active treatment should be performed to improve maternal heart function and promote fetal maturity.Apropriate threatment during per-cesarean section may decrease the case fatality of the mother and neonate.

BACKGROUND:Whether adipose-derived mesenchymal stem cells are able to exert immunomodulatory effects in the treatment of myocardial infarction, as wel as the best time, is less reported.
OBJECTIVE:To observe the effect of adipose-derived mesenchymal stem cells on inflammatory reaction and ventricular remodeling after myocardial infarction, and to explore the possible mechanisms of adipose-derived mesenchymal stem cells for the treatment of myocardial infarction.
METHODS:Enzyme digestion method was employed to isolate and culture rat adipose-derived mesenchymal stem cells. By ligation of the left anterior descending coronary artery, we established animal models of myocardial infarction in 40 rats. The rats were randomly divided into four groups:sham group, control group (injected high-glucose Dulbecco’s modified Eagle’s medium), 3-hour transplantation group (transplanted adipose-derived mesenchymal stem cells after 3 hours of myocardial infarction), 7-day transplantation group (transplanted adipose-derived mesenchymal stem cells after 7 days of myocardial infarction). After 14 days of operation, the levels of tumor necrosis factor-αand interleukin-10 in the plasma were detected by enzyme linked immunosorbent assay. After 28 days of operation, the left ventricular end diastolic diameter, left ventricular end systolic diameter, left ventricular ejection fraction and left ventricular fractional shortening were measured by echocardiography.
RESULTS AND CONCLUSION:Compared with the control group, in the 3-hour transplantation group and 7-day transplantation group, the levels of tumor necrosis factor-αwere significantly lower (P<0.01), and the levels of interleukin-10 were significantly higher (P<0.01) at postoperative 14 days;the left ventricular end diastolic diameter and left ventricular end systolic diameter in the two transplantation groups were also significantly smal er (P<0.05), but left ventricular ejection fraction and left ventricular fractional shortening were significantly elevated (P<0.05), which was more apparent in the 3-hour transplantation group than the 7-day transplantation group. Adipose-derived mesenchymal stem cells transplantation in acute phase of myocardial infarction can suppress the inflammatory response, regulate the cytokine network equilibrium, and thus delay ventricular remodeling and improve cardiac function.

Objective:To determine the effects of silencing glucose regulated protein ( GRP94 ) on the proliferation and apoptosis of breast carcinoma MCF7 cells. Methods:Chemically synthesized siRNA targeting GRP94 gene and transfected into MCF7 cells used by Liopfectamine RNAIMAX. The mRNA and protein expression levels of GRP94,cyclinD1,Bax and Bcl-2 were detected by Real-time PCR and Western blot. CCK8 assay was used to detect the effect of specific GRP94 siRNA on cell proliferation and the effect on cell cycle and apoptosis were analyzed by flow cytometry and Hoechst 33258 staining. Results:Compared with the siRNA-NC cells, the expression of GRP94 was significantly down-regulated in MCF7 cells. Knockdown of GRP94 in MCF7 cells decreased cell proliferation and promoted cell apoptosis. The expression of cyclinD1and Bcl-2levels were significantly reduced, and Bax level was increased in siRNA-GRP94 MCF7 cells. Conclusion: The siRNA-mediated GRP94 silence significantly inhibits MCF7 cell proliferation,promoted cell apoptosis by down-regulating cyclin D1,Bcl-2 expression and up-regulating the Bax expression in MCF7 cells.

Objective To explore the causes and the consequences of iatrogenic bile duct injury as well as experiences in its diagnosis and treatment. Method The clinical data of 28 in-patients who suffered from bile duct injury followed by cholecystectomy during January 1995 to September 2011 were collected and retrospectively analyzed. Result Bile duct injuries were found and diagnosed in al 28 in-patients during the processes of reoperation. Different treatments were carried out. 8 cases with mild injury were treated by placing the abdominal cavity drainage. 6 cases with bile duct split were repaired and set up with T tube drainage. 4 cases were initially treated by bile-intestinal Roux-y anastomosis. 1 case received repair operation of bile-intestinal Roux-y anastomosis after the external drainage of bile. 9 cases were initially treated with end-end bile duct anastomosis and 7 of 9 cases with concurrent anastomotic stenosis were performed repairing re-operations twice or more than twice. Among 7 cases, 1 case was performed with the operation of umbilical vein flap repair while 6 cases were treated with bile-intestinal Roux-y anastomosis repair. All cases in this observation were followed up to two years after repairing surgery:2 patients died and the rest 26 patients recovered after treatment. Conclusions The initial repairing operation is critical for iatrogenic bile duct injury and bile-intestinal Roux-y anastomosis should be the first choice of therapy,and it should be operated by experienced surgeons.

Medical students face higher levels of stress compared to the general population. Statistical analyses of questionnaire surveys were made to compare the teaching effect between traditional teaching and PBL.The results indicate that the PBL teaching is more conducive to students to relief from the course-related stress in medical colleges.

Objective To compare the dosimetry between inversely optimised intensity-modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy using the field-in-field technique (FIF) for whole-breast radiotherapy with a boost to the tumor bed after breast-conserving surgery.Methods IMRT and FIF treatment plans were respectively performed and optimised for 9 patients with early stage leftbreast cancer after breast-concerving surgery.The prescribed dose of breast was 50.4 Gy in 28 fractions,1.8 Gy per fraction and that of tumor bed was 61.6 Gy in 28 fractions,2.2 Gy per fraction.The conformity index,the dose and volume for OAR( organs at risks),time of planning and treatment for the two plans were compared.Results The conformity index(CI) for IMRT was improved compared with the FIF in breast [(1.82±0.16) vs.(2.21±0.15)] and tumor bed [(1.19±0.04) vs.(1.59±0.11),t=2.08,3.97,P ＜ 0.05 ].There was no difference for V20 of ipsilateral lung and V30 of heart between two plans.The Dmax and Dmean of the contralateral lung of FIF were (5.41 ±2.76) and (0.51 ±0.10) Gy,lower than those of IMRT [ (25.72 ± 2.61 ) and (7.46 ± 0.39) Gy,t =-22.44,- 21.14,P ＜ 0.05 ].The Dmax and Dmean of the contralateral breast of FIF were (8.50 ± 5.61 ) and (0.47 ± 0.11 ) Gy,lower than those of IMRT [(27.73±4.30) and (6.38±0.48) Gy,t=-5.66,-14.83,P＜0.05].ForFIF,theV5of the contralateral lung and breast were (0.09 ± 0.09) ％ and (0.45 ± 0.45 ) ％,respectively,lower than those of IMRT,which were (84.66 ±3.06) ％ and (60.79 ±4.94)％ (t =-28.19,- 12.80,P＜0.05).The time of optimised plan was (61.57 ± 0.89) min for FIF and(241.28 ± 1.06) min for IMRT (t=-32.35,P＜0.05),and that of treatment were (16.14±1.42) min for FIF and (29.85 ±0.59) min for IMRT (t =- 8.82,P ＜ 0.05).Conclusions For patients with early stage breast cancer after breast-concerving surgery,IMRT could improve the conformity index of target but increase the dose of eontralateral lung and breast.However,FIF has advantage on the time of optimising plan and treatment.

ObjectiveTo discuss the feasibility of the method that can be used to induce the model of type 2 diabetic mellitus rat and explore the characteristic of the nephropathy.The rats were fed with the high sucrose,high fat and high energy feed for a long time and then it was injected with the low dose STZ.Methods30 SD rats were selected and then it was randomly divided them into 2 groups,the control group (10 rats) and the model group (20 rats).The model group was fed with the high calorie feed forl0 weeks to induce insulin resistance and then the rats were induced to type 2 diabetes mellitus by injection of streptozocin (30 mg/kg).The rats of the model group were continually fed with the high calorie feed for 2 months.Before the end of this study,the 24-hours microalbuminuria,serum creatinine and blood urea nitrogen were detected and the periodic acid Schiff staining on the kidney were also measured.ResultsAfter the rats of the model group were established,the levels of the bodyweight,the cholesterol,the triglyceride and the insulin were [ (468.7 ± 8.8 ) g,( 1.92 ± 0.27 ) mmol/L,( 1.32 ± 0.34) mmol/L,(38.81 ± 5.39 ) mU/L ] respectively,all of them were higher than the levels in the normal group,which were [ (436.9 ± 7.4) g,(1.16 ±0.17)mmol/L,(0.8 ±0.18)mmo1/L,(21.43 ±4.19)mU/L],respectively( t =9.755,8.077,4.437,8.902,P ＜ 0.01 ).After injection of STZ for 2 weeks,the levels of the blood glucose,the insulin and the insulin resistance of the diabetes mellitus rats were [ ( 19.31 ± 1.55 ) mmol/L,( 31.31 ± 8.60) mU/L,(26.55 ± 6.33) ] respectively,it was higher than levels inf the normal group,which was[ (5.45 ±0.69) mmol/L,( 19.97 ± 3.26) mU/L,(4.82 ± 0.84) ] ( t =26.383,3.951,10.719,P ＜ 0.01 ).Before the end of this study,the levels of the blood glucose,insulin resistance,24-hours microalbuminuria,serum creatinine,blood urea nitrogen of the diabetes mellitus rats were [ ( 19.27 ± 1.97 ) mmol/L,( 16.70 ±7.51 ),(72.49 ± 8.53 ) mg/24 h,( 74.76 ± 8.38 ) μmol/L,( 19.09 ± 4.21 ) mmol/L],it was higher than the levels in the normal group,which were [ (5.62 ±0.65) mmol/L,(5.45 ± 1、33),( 15.26 ±2.20) mg/24 h,(40.81 ± 1.97) μmol/L,(9.87 ±2.13) mmol/L,t =20.961,4.657,20.623,12.495,6.352,P ＜0.01 ].And the pathological changes of the diabetes mellitus rats kidney tissues were the most serious through themethod of periodic acid-Schiff's staining (PAS).ConclusionsThe model of type 2 diabetic mellitus rat was constructed through the way of feeding the SD rats with high sucrose,high fat and high energy feed for a long time and low dose STZ.The diabetic mellitus rats had the symptom of drinking more,eating more and diuresis,and the character of this model had high levels of albuminuria,serum creatinine,blood urea nitrogen.The incrassated glomerular mesangium,the crescent-shaped focus and the glomerulosclerosis were also observed through the PAS.

Objective To study the prevention,diagnosis and treatment of the pulmonary embolism after abdominal surgery.Methods The clinical data of patients with acute pulmonary embolism(PE) after abdominal surgery between July 2008 and June 2012 were analyzed retrospectively.The high-risk patients received D-dimer,deep venous ultrasound and pulmonary CT examination to confirm the diagnosis postoperatively.Anticoagulation,thrombolysis,inferior vena cava filter placement were carried out in these patients.The high-risk patients received low molecular weight heparin(LMWH) to prevent PE from January 2010.Results 5 patients with PE survived and 3 patients died.The incidence of venous thromboembolism event was 0.43％ (13/3012) before January 2010 and PE was 0.20％ (6/3012).The incidence of venous thromboembolism event was 0.15％ (7/4803) after taking preventive measures and PE was 0.04％ (2/4803).There was no PE within 1 week since using LMWH after 2010.Lower limb DVT was found in 7 patients including 2 patients with PE after LMWH discontinuance within 2-3 weeks postoperatively.Conclusions Early prevention,diagnosis and treatment of postoperative PE are important for high-risk patients.