BACKGROUND:Pauwels type Ⅲ femoral neck fractures may be subjected to more shear and bending forces,and may be prone to complications such as internal fixation failure,bone nonunion,or femoral head necrosis. There is no consensus on the optimal selection of internal fixation devices.OBJECTIVE:To compare the biomechanical properties of four types of internal fixation methods for Pauwels type Ⅲ femoral neck fracture by finite element analysisMETHODS:Femur CT data of a healthy young volunteer were imported into Mimics software to construct a three-dimensional model of normal femur. Pauwels type Ⅲ femoral neck fracture was simulated based on 70° fracture line. Four types of fracture internal fixation models were optimized and constructed using Geomagic and UG software:conventional inverted triangle hollow screw,femoral neck fixation system,femoral neck fixation system plus anterior or posterior hollow screw treatment. Finally,Ansys software was used to analyze the stress distribution,peak stress,and peak displacement of proximal femur fracture block in four types of different internal fixation models. The displacement distribution and peak displacement of internal fixation device and femoral neckfracture were observed.RESULTS AND CONCLUSION:(1) The peak stress of proximal fracture fragments in the four groups was concentrated near the fracture line. The peak stress in the femoral neck fixation system group was the largest,and that in the conventional inverted triangle hollow screw group was the smallest. (2) The peak displacement of fracture fragments was located at the top of the femoral head. The peak displacement of the conventional inverted triangle hollow screw group was the largest,and that in the femoral neck fixation system+hollow screw (posterior) group was the smallest. (3) The peak displacement of the internal fixation model was located at the top of the model. The peak displacement was maximum in the conventional inverted triangle hollow screw group and minimum in the femoral neck fixation system+hollow screw (posterior) group. (4) The displacement of the fracture surface in the femoral neck fixation system+hollow screw (posterior) group was at the upper part of the fracture end. The peak displacement was the largest in the conventional inverted triangle hollow screw group and the smallest in the femoral neck fixation system+hollow screw (posterior) group. (5) It is indicated that compared with the other three internal fixation methods,femoral neck fixation system+hollow screw (posterior) group showed good biomechanical stability. When Pauwels type Ⅲ femoral neck fracture occurs in a young person,from the point of view of finite element analysis,it may be a more favorable choice to treat the Pauwels type Ⅲ femoral neck fracture.

BACKGROUND:Pauwels type Ⅲ femoral neck fractures may be subjected to more shear and bending forces,and may be prone to complications such as internal fixation failure,bone nonunion,or femoral head necrosis. There is no consensus on the optimal selection of internal fixation devices.OBJECTIVE:To compare the biomechanical properties of four types of internal fixation methods for Pauwels type Ⅲ femoral neck fracture by finite element analysisMETHODS:Femur CT data of a healthy young volunteer were imported into Mimics software to construct a three-dimensional model of normal femur. Pauwels type Ⅲ femoral neck fracture was simulated based on 70° fracture line. Four types of fracture internal fixation models were optimized and constructed using Geomagic and UG software:conventional inverted triangle hollow screw,femoral neck fixation system,femoral neck fixation system plus anterior or posterior hollow screw treatment. Finally,Ansys software was used to analyze the stress distribution,peak stress,and peak displacement of proximal femur fracture block in four types of different internal fixation models. The displacement distribution and peak displacement of internal fixation device and femoral neckfracture were observed.RESULTS AND CONCLUSION:(1) The peak stress of proximal fracture fragments in the four groups was concentrated near the fracture line. The peak stress in the femoral neck fixation system group was the largest,and that in the conventional inverted triangle hollow screw group was the smallest. (2) The peak displacement of fracture fragments was located at the top of the femoral head. The peak displacement of the conventional inverted triangle hollow screw group was the largest,and that in the femoral neck fixation system+hollow screw (posterior) group was the smallest. (3) The peak displacement of the internal fixation model was located at the top of the model. The peak displacement was maximum in the conventional inverted triangle hollow screw group and minimum in the femoral neck fixation system+hollow screw (posterior) group. (4) The displacement of the fracture surface in the femoral neck fixation system+hollow screw (posterior) group was at the upper part of the fracture end. The peak displacement was the largest in the conventional inverted triangle hollow screw group and the smallest in the femoral neck fixation system+hollow screw (posterior) group. (5) It is indicated that compared with the other three internal fixation methods,femoral neck fixation system+hollow screw (posterior) group showed good biomechanical stability. When Pauwels type Ⅲ femoral neck fracture occurs in a young person,from the point of view of finite element analysis,it may be a more favorable choice to treat the Pauwels type Ⅲ femoral neck fracture.

Objective:To identify whether splenectomy for treatment of hypersplenism has any impact on development of hepatocellular carcinoma(HCC) among patients with liver cirrhosis and hepatitis.Methods:Patients who underwent splenectomy for hypersplenism secondary to liver cirrhosis and portal hypertension between January 2008 and December 2012 were included from seven hospitals in China, whereas patients receiving medication treatments for liver cirrhosis and portal hypertension (non-splenectomy) at the same time period among the seven hospitals were included as control groups. In the splenectomy group, all the patients received open or laparoscopic splenectomy with or without pericardial devascularization. In contrast, patients in the control group were treated conservatively for liver cirrhosis and portal hypertension with medicines (non-splenectomy) with no invasive treatments, such as transjugular intrahepatic portosystemic shunt, splenectomy or liver transplantation before HCC development. All the patients were routinely screened for HCC development with abdominal ultrasound, liver function and alpha-fetoprotein every 3 to 6 months. To minimize the selection bias, propensity score matching (PSM) was used to match the baseline data of patients among splenectomy versus non-splenectomy groups. The Kaplan-Meier method was used to calculate the overall survival and cumulative incidence of HCC development, and the Log-rank test was used to compare the survival or disease rates between the two groups. Univariate and Cox proportional hazard regression models were used to analyze the potential risk factors associated with development of HCC.Results:A total of 871 patients with liver cirrhosis and hypertension were included synchronously from 7 tertiary hospitals. Among them, 407 patients had a history of splenectomy for hypersplenism (splenectomy group), whereas 464 patients who received medical treatment but not splenectomy (non-splenectomy group). After PSM,233 pairs of patients were matched in adjusted cohorts. The cumulative incidence of HCC diagnosis at 1,3,5 and 7 years were 1%,6%,7% and 15% in the splenectomy group, which was significantly lower than 1%,6%,15% and 23% in the non-splenectomy group ( HR=0.53,95% CI:0.31 to 0.91, P=0.028). On multivariable analysis, splenectomy was independently associated with decreased risk of HCC development ( HR=0.55, 95%CI:0.32 to 0.95, P=0.031). The cumulative survival rates of all the patients at 1,3,5,and 7 years were 100%,97%,91%,86% in the splenectomy group,which was similar with that of 100%,97%,92%,84% in the non-splenectomy group ( P=0.899). In total,49 patients (12.0%) among splenectomy group and 75 patients (16.2%) in non-splenectomy group developed HCC during the study period, respectively. Compared to patients in non-splenectomy group, patients who developed HCC after splenectomy were unlikely to receive curative resection for HCC (12.2% vs. 33.3%,χ2=7.029, P=0.008). Conclusion:Splenectomy for treatment of hypersplenism may decrease the risk of HCC development among patients with liver cirrhosis and portal hypertension.

Objective:To identify whether splenectomy for treatment of hypersplenism has any impact on development of hepatocellular carcinoma(HCC) among patients with liver cirrhosis and hepatitis.Methods:Patients who underwent splenectomy for hypersplenism secondary to liver cirrhosis and portal hypertension between January 2008 and December 2012 were included from seven hospitals in China, whereas patients receiving medication treatments for liver cirrhosis and portal hypertension (non-splenectomy) at the same time period among the seven hospitals were included as control groups. In the splenectomy group, all the patients received open or laparoscopic splenectomy with or without pericardial devascularization. In contrast, patients in the control group were treated conservatively for liver cirrhosis and portal hypertension with medicines (non-splenectomy) with no invasive treatments, such as transjugular intrahepatic portosystemic shunt, splenectomy or liver transplantation before HCC development. All the patients were routinely screened for HCC development with abdominal ultrasound, liver function and alpha-fetoprotein every 3 to 6 months. To minimize the selection bias, propensity score matching (PSM) was used to match the baseline data of patients among splenectomy versus non-splenectomy groups. The Kaplan-Meier method was used to calculate the overall survival and cumulative incidence of HCC development, and the Log-rank test was used to compare the survival or disease rates between the two groups. Univariate and Cox proportional hazard regression models were used to analyze the potential risk factors associated with development of HCC.Results:A total of 871 patients with liver cirrhosis and hypertension were included synchronously from 7 tertiary hospitals. Among them, 407 patients had a history of splenectomy for hypersplenism (splenectomy group), whereas 464 patients who received medical treatment but not splenectomy (non-splenectomy group). After PSM,233 pairs of patients were matched in adjusted cohorts. The cumulative incidence of HCC diagnosis at 1,3,5 and 7 years were 1%,6%,7% and 15% in the splenectomy group, which was significantly lower than 1%,6%,15% and 23% in the non-splenectomy group ( HR=0.53,95% CI:0.31 to 0.91, P=0.028). On multivariable analysis, splenectomy was independently associated with decreased risk of HCC development ( HR=0.55, 95%CI:0.32 to 0.95, P=0.031). The cumulative survival rates of all the patients at 1,3,5,and 7 years were 100%,97%,91%,86% in the splenectomy group,which was similar with that of 100%,97%,92%,84% in the non-splenectomy group ( P=0.899). In total,49 patients (12.0%) among splenectomy group and 75 patients (16.2%) in non-splenectomy group developed HCC during the study period, respectively. Compared to patients in non-splenectomy group, patients who developed HCC after splenectomy were unlikely to receive curative resection for HCC (12.2% vs. 33.3%,χ2=7.029, P=0.008). Conclusion:Splenectomy for treatment of hypersplenism may decrease the risk of HCC development among patients with liver cirrhosis and portal hypertension.

Objective To explore the association of catechol-O-methyhransferase(COMT) gene polymorphisms with schizophrenia susceptibility and its symptoms assessed by Positive and Negative Syndrome Scale (PANSS)in southern Chinese population.Methods COMT gene rs4633,rs4680 and rs8185002 polymorphisms were genotyped using Sequenom genotyping technology in 700 schizophrenia patients (300 Zhuang and 400 Han) and 700 healthy controls (300 Zhuang and 400 Han),and Positive and Negative Syndrome Scale (PANSS) was used for clinical symptoms assessment of patients.Statistical analysis was performed using PLINK software.Results rs4633,rs4680 and rs8185002 polymorphisms were not significantly associated with schizophrenia susceptibility in Zhuang or Han population respectively(P＞0.05).After merging Zhuang and Han samples,rs4633(I 2 =0.000,Pmeta =0.040) and rs4680 (I2=0.000,Pmeta =0.014) were significantly associated with the susceptibility to schizophrenia.In addition,haplotype T-A-T was significantly associated with schizophrenia susceptibility (P=0.049).However,these three polymorphisms were not significantly associated with total score,positive scale score,negative scale score and general psychopathology scale score assessed by PANSS(P＞0.05).Conclusion COMT gene rs4633 and rs4680 polymorphisms are involved in the susceptibility to schizophrenia in southern Chinese population.

ObjectiveTo test the the association between PRODH gene variant rs385440 and the susceptibility to schizophrenia and the severity of schizophrenia in Guangxi Zhuang and Han population,further exploring the genetic mechanisms of schizophrenia in Guangxi Zhuang and Han population.MethodsThe schizophrenia patients were diagnosed according to ICD-10 criteria in this study.The subjects in the association analysis were 282 unrelated schizophrenia patients(94 Zhuang and 188 Han) and 282 healthy controls (94 Zhuang and 188 Han).A quantitative real-time PCR TaqMan MGB experimental method was carried out to analysis rs385440.The clinical psychotic symptoms of 246 schizophrenia patients (83 Zhuang and 163 Han) were assessed by PANSS.Statistical analyses were carried out with SPSS13.0 for windows.ResultsThere was no statistically significant difference in different allele and genotype frequencies of rs385440 between schizophrenia cases and controls in Zhuang samples,Han samples and combined samples respectively (P＞ 0.05 ).In Zhuang schizophrenia patients the score of N4 (passive/apathetic social withdrawal) item in A allele carriers (3.28 ± 1.34) was higher than that of G allele carriers ( 2.40 ± 1.36 ) significantly (P ＜ 0.05 ),and the score of G12 ( lack of judgment and insight) item in A allele carriers(4.92 ± 1.55 ) was higher than that of G allele carriers ( 4.12 ± 1.85 ) significantly (P ＜ 0.05 ).Conclusion There is no association between PRODH gene variant rs385440 and the susceptibility to schizophrenia in Guangxi Zhuang and Han population.Rs385440 associated the severity of passive/apathetic social withdrawal symptom and poor attention symptom of schizophrenia in Zhuang.