The learning passion,apprehension and master of probation knowledge and practice capacity of probationers have improved greatly by applying the teaching method of stage-separated to echelon teaching on the basis of the cognitive law and focusing on clinical operation practice.Meanwhile,this method has effectively improved clinical probation teaching quality of orthopedics.

ObjectiveTo observe the spinal cord pathological change and hindlimbs motor function of rats after decompression on chronic spinal cord injury.Methods 30 Wistar rats were divided randomly into conrol group ( n =5 ),compression group ( n =5 ) and decompression group ( n =20 ),then the decompression group was subdivided into 4 parts as 1 week,2 weeks,4 weeks,6 weeks after decompression.Decompression was made after 30 days of chronic spinal cord copression injury,rats'motor function was detected by inclined plate experiment,the histopathological change,Nissl body and neural cells apoptosis in different spinal cord sections were assessed by the stainings of HE,Nissl and TUNEL.ResultsCompared with control group,the behavior testing showed all rats in compression group presented with weakness of muscle power in their hindlimbs (P ＜ 0.01 ),but the hindlimbs motor functions recovered from the first week after decompression and the difference had statistical significance compared with the compression group(P＜ 0.01 ).Then the rats hindlimbs functions recovered gradually later on.The staining of HE,Nissl and TUNEL showed that the injured spinal cord section performed no improvement at the first 2 weeks after decompression,the neural apoptosis index(24.31 ± 4.73 )％ decreased until the forth week after decompression(P＜0.05).The spinal cord segments closed to the injured part recovered in early stage.At 1 week after decompression,lots of Nissl bodys were observed in spinal anterior horn,the neural apoptosis index in the 2 sections closed to the injured part were ( 15.21 ± 4.81 ) ％ and ( 16.21 ± 3.98 ) ％,which declined observably compared with compression group(P ＜ 0.05 ).ConclusionAfter decompression on chronic spinal cord injury,the recovery of rats'hindlimbs motor function in early stage is probably benefited by the functional compensation of the spinal cord segments closed to the injured section.

Objective:To study the effect of melatonin(Mel),a potent antioxidant,on the oxidative stress and the activity of hypothalamo-pituitary-adrenal axis in diabetic rats.Methods:Male SD rats were assigned to the following 4 groups:normal control(treated with 2% ethyl alcohol lavage\[NC,n=6\]),diabetes mellitus control(treated with 2% ethyl alcohol lavage \[DM,n=7\]),diabetes mellitus model group 1(treated with Mel lavage \[10 mg?kg-1?d-1,DM+Mel1,n=6\]),diabetes mellitus model group 2(treated with Mel lavage \[0.2 mg?kg-1?d-1,DM+Mel2,n=6\]).Diabetes in DM group,DM+Mel1 group and DM+Mel2 group was induced by intraperitoneal injection of streptozotacin(65 mg/kg).Blood glucose,body weight and adrenal gland weight/body weight(AW/BW)were determined in the 4 groups 12 weeks later;malondialdehyde(MDA)was examined with visible spectrophotometry;blood total cholesterol(TC)and triglyceride(TG)were examined with enzymology method;blood corticotrophin-releasing hormone(CRH),adreno-corticotrophic hormone(ACTH)and corticosterone(CORT)were examined with radioimmune method.Results:Blood glucose,MDA,TC,TG,CRH,ACTH,CORT and AW/BW in DM group were significantly higher than those in NC group(P

Objective To explore the clinical efficacy of single-port Da Vinci robotic surgical system in the radical gastrectomy of gastric cancer.Methods The retrospective descriptive study was conducted.The clinical data of the first patient in China who underwent single-port radical gastrectomy of gastric cancer using Da Vinci robotic surgical system in the Southwest Hospital of the Third Military Medical University in June 2017 were collected.Patient underwent radical gastrectomy of gastric cancer using single-port Da Vinci robotic surgical system +D2 lymph node dissection + Billroth Ⅱ anastomosis.Observation indicators:(1) intra-and post-operative situations;(2) follow-up and patients' survival.Follow-up using outpatient examination and telephone interview was performed to detect the patients' postoperative survival up to July 2017.Results (1) Intra-and postoperative situations:patient underwent radical distal subtotal gastrectomy of gastric cancer using single-port Da Vinci robotic surgical system.Operation time and volume of intraoperative blood loss were respectively 303 minutes and 100 mL.There was no intraoperative complication.The distances from tumor to proximal margin and distal margin were 5 cm and 6 cm.Number of lymph node dissected and length of abdominal incision were 51 and 3 cm.Time of gastric tube removal,time for out-of-bed activity,time of gastrointestinal function recovery,time of drainage tube removal and postoperative pain score were 17 hours,24 hours,36 hours,36 hours and 3,respectively.Patient took a little fluid diet after gastric tube removal.There was no occurrence of postoperative complication.Results of pathological examination showed that tumor invaded deep muscular layer,with 2 positive lymph nodes in No.3 and negative proximal and distal margins.Pathological staging was pT2N1M0 (Ⅱa staging).Duration of hospital stay was 6 days.(2) Follow-up and patients' survival:patient was followed up for 1 month,with a good survival.Conclusion The single-port Da Vinci robotic surgical system is safe and feasible in the radical gastrectomy of gastric cancer,with good short-term outcomes.

AIM: To observe the effects of valsartan on the cardiac hypertrophy and the expression of PTEN in spontaneously hypertensive rats (SHR). METHODS: Twenty 12-week-old male SHR were randomly divided into 2 groups:SHR positive control group and valsartan treating group ( 30 mg?kg -1?d -1). 10 homogenous Wistar-kyoto (WKY) rats were served as normal control group. Blood pressure and the ratio of left ventricular weight to body weight(LVW/BW)of rats were monitored periodically during the 8-weeks studies. Expression of PTEN in cardiac myocytes was determined by immunohistochemistry. RESULTS: Blood pressure and LVW/BW increased in the valsartan group more than those in the SHR control group, and the expression of PTEN in cardiac myocytes in valsartan group increased more than that in the SHR control group, but the indexes were lower than those in the WKY group. CONCLUSION: Valsartan can not only inhibit the progression of cardiac hypertrophy in spontaneously hypertensive rats, but also increase the expression of PTEN. PTEN may play a role in cardiac hypertrophy.

Objective To explore the safety and feasibility of vagus nerve-preserving Da Vinci robotassisted radical gastrectomy for gastric cancer.Methods The retrospective cross-sectional study was conducted.The clinicopathological data of 12 gastric cancer patients who underwent vagus nerve-preserving Da Vinci robotassisted radical gastrectomy at the Southwest Hospital of the Third Military Medical University from January 2015 to November 2016 were collected.All patients underwent vagus nerve-preserving Da Vinci robot-assisted radical gastrectomy for gastric cancer.During operation,lymph node dissection of the pyloric region,the right side of the cardia and the superior margin of the pancreas were noticed,and other surgical procedures were the same as the traditional Da Vinci robot-assisted radical gastrectomy.Observation indicators:(1) intra-and post-operative situations:surgical methods,digestive tract reconstruction,operation time,volume of intraoperative blood loss,number of lymph node dissected,results of postoperative pathological examination,recovery time of gastrointestinal function,time for liquid diet intake,duration of postoperative hospital stay,short-term surgery-related complications (postoperative bleeding,anastomotic fistula,obstruction and intra-abdominal infection);(2)follow-up situations:postoperative long-term complications (gastric retention,alkaline reflux gastritis,dumping syndrome,gallbladder disease and cholelithiasis),postoperative quality of life (diet,upper abdominal discomfort,nausea,vomiting and diarrhea),postoperative nutritional status [body weight,hemoglobin (Hb),total protein (TP),albumin (Alb)] and tumor recurrence.Follow-up using telephone interview and outpatient examination was performed up to December 2016.Telephone interview included detecting diet of patients,digestive tract symptoms and body weight.Routine blood test,liver and kidney functions,tumor markers,chest X-ray,abdominal computed tomography (CT) or color Doppler ultrasound and gastroscopy of outpatient examinations were performed to detect tumor recurrence and metastasis.Measurement data with normal distribution were represented as x±s and measurement data with skewed distribution were described as M (range).Results (1) Intra-and post-operative situations:all the 12 patients underwent successful vagus nerve-preserving Da Vinci robot-assisted radical gastrectomy for gastric cancer,without conversion to laparoscopic surgery or open surgery,including 2 patients with D1 lymphadenectomy,2 patients with extended D1 lymphadenectomy and 8 patients with D2 lymphadenectomy.Five and 7 patients underwent respectively Billroth Ⅰ anastomosis and Billroth Ⅱ anastomosis of digestive tract reconstruction.Operation time,volume of intraoperative blood loss and number of lymph node dissected of 12 patients were (247± 34) minutes,(94 ± 23) mL and 27 ± 7,respectively.Results of postoperative pathological examination showed that distal and proximal surgical margins of 12 patients were negative and achieved R0 resection;326 lymph nodes were dissected,6 patients didn't have lymph node metastasis and 18 positive lymph nodes were detected in 6 patients.Recovery time of gastrointestinal function,time for liquid diet intake and duration of postoperative hospital stay in 12 patients were (57±14)hours,(64± 14)hours and (7.3±0.9)days,respectively.There was no occurrence of short-term surgery-related complications.(2) Follow-up situations:12 patients were followed up by telephone interview (10 receiving outpatient exaninations) for 9 months (range,1-20 months).Of 12 patients with long-term complications,2 had loss of appetite,1 had diarrhea,without occurrence of cholelithiasis,cholecystitis,gastric retention and dumping syndrome.Of 10 patients receiving outpatient examinations,body weight,Hb,TP and Alb were (56± 12) kg,(126± 10) g/L,(69.9±5.1) g/L,(43.2±3.3)g/L at 1 month postoperatively and (52±13)kg,(126±10)g/L,(72.1±2.4)g/L,(45.2±1.6)g/L at 3 months postoperatively,respectively,with negative carcinoembryonic antigen.There was no tumor recurrence and metastasis in 12 patients.Conclusion Vagus nerve-preserving Da Vinci robot-assisted radical gastrectomy is safe and feasible for gastric cancer,which has not affected the lymph node dissection and incidence of surgeryrelated complications,and it also can improve the postoperative quality of life and maintain good nutritional status.

Objective To evaluate the efficacy of noninvasive positive-pressure ventilation (NPPV) on acute respiratory failure (ARF) in elderly patients with severe community-acquired pneumonia (CAP).Methods 321 CAP patients with ARF aged over 65 years [(75.6±12.2) years old in averag] were randomly treated with NPPV (n=162) and the standard oxygen therapy (n=159).Intubation rate,ARF control rate and total mortality were compared between the two groups,and the risk factors were analyzed.Results 90％ of 321 patients presented with hypoxemic respiratory failure.Compared with standard therapy group,the intubation rate was lower in NPPV group (46.9％ vs.64.2％,x2=9.652,P＜0.01).However,there were no differences in ARF control rate(77.9％ vs.72.3％,x2 =1.274,P＞0.05),overall 30-day mortality and 90-day survival between the two groups.The overall mortality in NPPV group was higher in treatment failure cases than in treatment success cases (48.7％ vs.11.6％,x2=26.900,P＜0.01).The independent risk factors for death were treatment failure in NPPV,higher simplified acute physiology score assessment,old age and mutilobar infiltrate.Conclusions NPPV can decrease the intubation rate in CAP patients with acute hypoxemic respiratory failure,but the overall efficacy is not significant.Delayed intubation should be avoided when NPPV is to be applicated.

BACKGROUND:Bone marrow mesenchymal stem cells are considered as commonly used seed cells to construct tissue-engineered for repair of bone and cartilage defects. It is of great significance for cytology and tissue engineering experiments to study the common problems existing in the basic operation and how to avoid these problems in a timely manner. OBJECTIVE:To summarize the common problems existing in the process of operation in order to provide reliable methods about separation, culture and identification of bone marrow mesenchymal stem cells for beginners and researchers. These can reduce or avoid some errors and problems during operation. METHODS:Sixteen New Zealand white rabbits were selected as experiment objects, and bone marrow mesenchymal stem cells were separated from rabbits by iliac puncture, purified and augmented by using density gradient centrifugation combined with adherent culture method. Then cellmorphology was observed by inverted phase contrast microscope, growth curve detected by MTT method and cellphenotype identified by flow cytometry. RESULTS AND CONCLUSION:We encountered some problems in the process of separation and culture, when we operated the first five rabbits. After careful y summarizing and analysis of the reasons, the operation was successful y completed on the rest 11 rabbits. Bacteria pol ution and cellaging were not found in the process of cellculture. What is more, the cells at passage 3 appeared with high-expression of CD29, and CD44, but low expression of CD14 and CD34. The cellgrowth curve showed that the proliferation activity of cells at passages 3 and 5 was higher than that at passage 10. Although the technology of separation, culture and identification of bone marrow mesenchymal stem cells is mature, the failure wil be happen if we do not pay attention to the details of operation. By strictly carrying out normal operations, we can get high purity of bone marrow mesenchymal stem cells, which lays a good foundation for celland animal experiments in the future.

Objective:To explore the torque effect of controlling root auxiliary arch on the straight wire appliance on maxillary anterior teeth.Methods:22 patients with class Ⅱ1 extraction treatment,treated with straightwire appliance,at the detailing treatment stage were treated with controlling root auxiliary arch over the erect or introverted maxillary incisors for positive torque.The main arch wire of 0.46 mm ×0.64 mm stainless steel edge wire was used in 14 cases,the main arch wire of 0.46 mm stainless steel round wire was used in 8 cases.Cephalometric results before and after maxillary incisor torque were analyzed by t test.Results:After maxillary incisor torque in the 22 cases 1-SN and UIa-NA value increased(P ＜0.01),positive torque was achieved by controlling root auxiliary arch on the upper incisors;the round wire maxillary incisor torque worked faster than the edge wire(P ＜0.05).Conclusion:At the detailing stage of treatment straight wire appliance on front teeth,controlling root auxiliary arch is simple and effective in the treatment of exces-sive erect or lingual inclination of maxillary incisor.

Purpose To investigate the expression of mismatch repair proteins MLH1,MSH2,MSH6 and PMS2 and their clinical significance in colorectal cancer.Methods Immunohistochemical analysis was used to detect MLH1,MSH2,MSH6 and PMS2 protein expression in formalin-fixed paraffin-embedded tissues from 102 colorectal cancer patients,and microsatellite instability (MSI) was tested in 20 cases.The relationship between MMR protein expression and clinical pathological features was also analyzed.Results 15 cases (14.7％) had MMR protein loss.The loss rate of MLH1,MSH2,MSH6 and PMS2 protein was 12.7％ (13/102),3.9％ (4/102),4.9％ (5/102) and 10.8％ (11/102),respectively.MLH1,MSH2,MSH6 and PMS2 protein losses were not related with gender,age,tumor size,depth of invasion and lymph node metastasis (P ＞ 0.05).MLH1 and PMS2 protein losses were related to histological differentiation (P ＜0.05).MSI was detected in 10 Lynch syndrome candidates.2 cases (2.0％)of high-frequency microsatellite instability (MSI-H) were identified,and the remaining 8 cases were MSS.However,10 cases without MMR expression abnormality all showed MSI-L/MSS.Conclusion Immunohistochemical detection of MLH1,MSH2,MSH6 and PMS2 can be used as primary screening for Lynch syndrome and its combination with MSI test can effectively increase the diagnostic rate in Lynch syndrome.