BACKGROUND:Usual mechanics experiment approach cannot be applied directly to human body and the inter-comparability of models is low.Therefore finite element numerical simulation to mechanical behavior of human body has become an effective method for better understanding of the human body.OBJECTIVE:To establish a three-dimensional finite element model of femoral osteoporosis.METHODS:According to the average Chinese femur parameters,1 male patient with severe osteoporosis,aged 86 years,with no hip joint diseases,was selected.The data of femoral osteoporosis was obtained by means of spiral CT scanning.The graphical data were processed by the Mimics 11.1 (a graph processing software),and the outline curve data of femoral bone cortex inside and outside surface were obtained.The curve data were imported into the Unigraphic NX4.0 for solid modeling.The femur three-dimensional model composed of the cortical bone,cancellous bone and medullary canal was obtained.The model data were imported into the Ansys 11.0 for operations such as assigning,meshing,and contact interactions to establish three-dimensional finite element model of osteoporotic femur.RESULTS AND CONCLUSION:Three-dimensional finite element model of femur of osteoporosis was successfully established,which provides a reliable method for the construction of finite element model of femoral osteoporosis,and creates conditions for investigating femoral osteoporosis fracture fixation method and joint replacement.

BACKGROUND:Alendronate is a new generation of diphosphate,which is the second generation of osteoporosis drugs.It is widely used to treat diseases related to increase of bone absorption in clinic.OBJECTIVE:To observe the effect of alendronate on the proliferation and the mRNA expression of osteoprotegerin(OPG) and receptor activator of nuclear factor kappa B ligand(RANKL) of human osteoblasts.DESIGN,TIME AND SETTING:A single sample observational experiment was performed at the Basic Research Institute of Chongqing Medical University from November 2007 to March 2008.MATERIALS:Osteoblasts were isolated from cancellous bone in a surgical operation.Alendronate was the product of Merck Sharp & Dohme S.p.A.METHODS:Osteoblasts were cultured with various concentrations of alendronate(1?10-9,1?10-8,1?10-7,1?10-6,1?10-5,1?10-4 mol/L).Osteoblasts cultured without alendronate were assigned as controls.MAIN OUTC0ME MEASURES:①The morphology and growth of osteoblasts were observed.②Effect of alendronate on the proliferation of osteoblasts were detected by MMT method.③The effect of various concentrations of alendronate on the mRNA expression of OPG and RANKL were detected by using RT-PCR.RESULTS:1?10-5 and 1?10-4 mol/L alendronate inhibited the proliferation of osteoblasts.1?10-9-1?10-6 mol/L alendronate promoted the proliferation of osteoblasts,and the 1?10-8 mol/L alendronate had the strongest effect.Alendronate inhibited RANKL mRNA expression in a concentration-dependent manner,1?10-5 mol/L alendronate had a strongest effect at 72 hours after culture(P

Objective To investigate the technique,safety and efficacy of percutaneous chemoablation of single and multiple confluent metastatic lymphatic nodes (LNs).Methods Forty six patients of malignant metastatic LNs were treated with percutaneous chemoablation with CT guidance,and they were divided into two groups,including 30 patients of single isolated metastatic LN (group A) and 16 patients of multiple and/or confluent metastatic LNs (group B).A mixture of 5 ml absolute ethyl alcohol,2 ml iodized oil and 10 mg epirubicin was injected into the lymph node(s).The average tumor diameter was (2.0 ± 0.5) cm in group A and (3.8 ± 0.6) cm in group B.The intratumoral drug coverage rate and the occurrence of reflux were recorded.Enhanced CT scans were performed to observe the therapeutic effects at the intervals of 3,6 and 12 months.Results The coverage rate was 100％ in group A,which was significantly higher than group B (70％ to 80％).The occurrence of reflux was 70％ for group A versus 40％ for group B.For group A,a complete response (CR) patients of 14,21,28 and a partial response (PR) patients of 16,9,2 were obtained at 3,6 and 12 months after therapy respectively.For group B,a CR patient of 0,0,0 and PR patients of 3,8,9 were observed at 3,6 and 12 months after therapy respectively.Standardized rate by direct method was performed and the CR rate (74.4％) for group A was higher than that for group B (0) (P =0.0001).The tumor FDG uptake was lower compared with the preoperative images.No serious complications were observed.A few patients had mild pain during the procedure,which was relieved after 2.0 to 3.0 ml of 2％ lidocaine injection adjacent to the tumor.No needle tract seeding or infection were observed.There was no effect on patients' overall survival.Conclusions CT-guided chemoablation is an effective,low-cost and minimally invasive procedure,which is better for treating single metastatic LN than multiple and/or confluent oues.

Objective To investigate the effects of estrogen on mismatch repiar gene expression in colonic mucosa in vivo. Methods A total of 42 healthy individuals underwent colonoscopy were enrolled in the study. Half an hour before colonoscopy examination, blood sample was taken for determining the serum estradiol (E2) level. N ormal colonic mucosal tissues determined by naked eye under colonoscopy examination were taken in the right hemi colon to detect HMLH1 and hMSH2 gene expression by semi-quantitative RT-PCR and immunohistochemistry staining. Then the correlation of serum E2 levels with hMLH1 and hMSH2 expression in colonic mucosa was analyzed. Results A bimodal curve was presented for the correlation between serum E2 level in healthy individuals and hMLH1 expression in colonic mucosa. A strong positive correlation of E2 level with hMLH1 expression in normal colonic mucosa was observed when serum E2 level was more than 45 pg/ml (For mRNA, P=0. 003, r=0. 701; for immunohistochemistry positivity index, P=0. 000, r=0. 874).However there was no correlation between E2 level and hMSH2 expression. Conclusion High serum E2 level might increase the hMLH1 gene expression in colonic mucosa in vivo.

Objective To investigate the clinical application of fast track surgery in patients undergoing elective colorectal carcinoma surgery. Methods Seventy patients with colorectal carcinoma requiring colorectal resection were randomized into two groups: fast-track group (35 cases) and conventional care group (35 cases). Results Sixty-two patients finished the study, 32 cases in fast-track group and 30 cases in conventional care group. The median and average time to the first passage of flatus (2±1 vs. 4±2, P<0.01), the first passage of stool (3.8±1.6 vs. 6.4±2.5, P=0.0007), resumption of normal diet [(4±2) vs. (8.2±2.2), P<0.01] and the length of postoperative stay (6±1 days vs. 11.7±3.8 days, P<0.01) were much shorter in the fast-track group than in the conventional care group. The preoperative incidence of thirst (2/32 vs. 23/30, P<0.01), hunger (5/32 vs. 20/30, P<0.01) and postoperative infectious complications (2/32 vs. 8/30, P=0.04) were much lower in the fast-track group than in the conventional care group. Conclusion Fast track surgery in patients undergoing elective colorectal resection was safe and effective.

Objective To explore clinical features,prognosis and study related cancer types in patients with familial gastric carcinoma. Methods Nine families of ICG-HGC and 3 families of suspected-ICG-HGC according with International Collaborative Group on Hereditary Gastric Cancer standard were collected and their pedigree trees were drawn.Clincial features and prognosis of ICG-HGC and suspected-ICG-HGC families were analyzed.and the related cancer types of ICG-HGC and suspected-ICG-HGC kindreds were investigated. Resuits The morbidity of ICG-HGC and suspected-ICG-HGC was 0.99%;The age of patients among the propositi of 12 kindreds were 29～65 years old with the mean age of 56 years old.Among 11 kindreds,there were 45 cases of cancers including 2 cases of multiple cancers.There were 30 foci of gastric cancer,most of which were located in lower and middle third of the stomach,with pathologic type of adenocarcinoma in poor to moderate differentiation.There were totally 15 extrastomach tumors including 7 colorectal cancers.Four cases of 11 kindreds had survived for 3 years including 1 case surviving for more than 10 years. Conclusion The familial gastric cancers in southern China have special characteristics such as poorly pathologic differentiation,advanced cancer stage,early age of onset,distal end of the stomach in location and high incidence of related tumors in colorectum.

Objective To summarise the clinicopathologic features and survival of gastric cancer at different tumor locations.Methods A total of 942 adult gastric cancer patients undergoing curative gastrectomy with lymphadenectomy were recruited from the First Affiliated Hospital,Sun Yat-sen University,and examined retrospectively.In all cases,patients' age,gender,pTNM stage and survival time were identified and recorded.Results There were 208 carcinoma cases at gastroesophageal junction (GEJ,22.1％),261 fundus/body cases (27.7％),445 antrum/pylorus cases (47.2％) and 28 whole stomach cases (3.0％).Compared with fundus/body and antrum/pylorus carcinoma,GEJ carcinomas were more often seen in males,among older patients,with larger tumor size and deeper infiltrated tumors,higher stage and worse 5-year disease-free survivals.Whole stomach carcinoma had predilection in female,younger patients,and at later stages and worst 5-year disease-free survival.Conclusions Gastric carcinomas differ greatly in biologic behavior and prognosis by anatomic locations.GEJ carcinoma has independent biologic features.Whole stomach carcinoma is of the highest malignancy and worst prognosis.

Objective To investigate the prognostic significance of extended resection for locally advanced colorectal carcinoma. Methods Clinical data of 960 cases of colorectal cancer hospitalized for surgery between Jan 1995 and Dec 2002 were reviewed, and complication rates, perioperative mortality, 5-year survival were calcualated, prognostic factors were analyzed using Cox regression model. Results Sixty-six patients with locally advanced colorectal carcinoma were treated with extended resection, accounting for 6.9% of the total cases. Surgical complication rate in this subgroup was 27.3% (18/66), relatively higher than that of conventional resection for colorectal carcinoma (?~2 =8.82, P=0.002). The perioperative mortality was zero. Pathology showed that carcinoma invasion into the adjacent organs resected en bloc was 31% (27/88), the 5-year survival rate was 62%. The tumor spreading into the adjacent organ (Wald=7.42,P=0.005) and lymph node status (Wald=4.55, P=0.035) were found to be the independent prognostic factors. Conclusions Extended resection for locally advanced colorectal carcinoma resulted in a favorable prognosis. Postoperative complication was relatively high, but still acceptable.

Objective To investigate the application of computer-aided 3D reconstruction and rapid prototyping(RP) technique in the correction of prominent mandibular angle.Methods Computer tomography scanning and 3D reconstruction were performed on 15 square face patients with prominent mandibular angles,then their actual mandible models were made by RP techniques.Surgical programs were made according to the model,including partial mandibular angle osteotomy,outer mandible table sagittal splitting osteotomy,chin augmentation with autogenous mandibule bones,and so on.In 15 cases,mandibular angle partial cutting was performed in 5 cases,sagittal splitting osteotomy in 6 cases,and mandibular angle partial cutting combined with splitting osteotomy in 4 cases.The autogenous mandibule bones were transplanted for chin augmentation in 3 chin microsomia patients.All the cases were treated according to the position and range set by the RP model.Results All the mandibular models produced by RP techniques were real and complete,which could directly and precisely show the state of the mandible.The operations completed smoothly and accomplished with the expected outcomes designed before operation.In all cases,the width of lower face was efficiently reduced and the face was symmetrical after operation.The follow-up period ranged from 3 months to 1 year in 12 patients,during which their facial appearances were in good condition and the results were satisfactory.Conclusion RP techniques is helpful in precise representation of the state of mandible,which providing ideal surgical models for accurate evaluation of prominent mandibular angle,design of surgical procedures as well as surgery instruction.It can provide good assistance to facial contour plastic surgery.

Objective To explore the correlation between COX-2 and Ki-67 expression and microvessel density in primary gastric cancer tissue and clinicopathological parameters and to investigate their effect on postoperative gastric cancer recurrence. Methods Forty-eight postoperative recurrent gastric cancer patients were enrolled in this study, their clinicopathologic characters of primary tumors were analyzed retrospectively and compared with 48 cases without recurrence. Expression of COX-2 and Ki-67 and microvessel density ( MVD) in gastric cancer tissue were detected by immunohistochemical method. Risk factors correlated with tumor recurrence were studied by univariate and multivariate analysis. Results Expression of COX-2, Ki-67 label index (LI) and MVD were correlated with each other, and they were all correlated with depth of invasion and TNM stages in gastric cancer tissue. Patients with pelvic metastatic lymph node, cancer invasion to serosa, of Borrmann III or IV, high COX-2 and MVD expression are on high risk of recurrence (P