BACKGROUND:There is still no consensus on the optimal internal fixation for the treatment of Pauwels Ⅲ femoral neck fracture,and most of the related finite element analyses have been performed using a single simplified loading condition,and the biomechanical properties of commonly used internal fixation devices need to be further investigated. OBJECTIVE:To analyze the biomechanical characteristics of Pauwels Ⅲ femoral neck fractures treated with cannulated compression screw,dynamic hip screw,and femoral neck system by finite element method under different loading conditions of single-leg standing loads and sideways fall loads. METHODS:The DICOM data of healthy adult femur were obtained by CT scanning,imported into Mimics 15.0 software to obtain the rough model of bone tissue.The data exported from Mimics were optimized by Geomagics software,and then three internal fixation models were built and assembled with the femur model according to the parameters of the clinical application of the cannulated compression screw,dynamic hip screw,and femoral neck system by using Pro/E software.Finally,the three internal fixation models were imported into Ansys software for loading and calculation to analyze the stress distribution and displacement of the femur and the internal fixation under different working conditions of single-leg standing loads and sideways fall loads,as well as the stress characteristics of the calcar femorale and Ward's triangle. RESULTS AND CONCLUSION:(1)Under the single-leg standing load and the sideways fall load,the proximal femoral stress of the three internal fixation models was mainly distributed above the fracture end of the femoral neck.The peak stress of the proximal femoral end,fracture end,Ward triangle,and calcar femorale of the three internal fixation models were the smallest in the femoral neck system model and the largest in the cannulated compression screw model.(2)Under the single-leg standing load and the sideways fall load,the peak displacement of the proximal femur of the three internal fixation models was all located at the top of the femoral head,and the peak displacement was the smallest in the femoral neck system model and the largest in the cannulated compression screw model.(3)The peak displacement of the three internal fixation models was all located at the top of the internal fixation device under the single-leg standing and sideways fall loading conditions,and the peak displacement values were the smallest in the femoral neck system internal fixation model and the largest in the cannulated compression screw internal fixation model.(4)The internal fixation stress of the three internal fixation models was mainly distributed in the area near the fracture end of the internal fixation device under the single-leg standing and sideways fall loads,and the peak value of internal fixation stress was the smallest in the femoral neck system model and the largest in the cannulated compression screw model.(5)These results suggest that the mechanical stability of the femoral neck system is the best,but there may be a risk of stress shielding of the fracture end and calcar femorale.The stress of the internal fixation device of the femoral neck system is more dispersed,and the risk of internal fixation break is lower.

Objective To investigate the expression and clinical significance of serum microRNA-144-3p(miR-144-3p)and microRNA-126-3p(miR-126-3p)in patients with intracerebral hemorrhage(ICH).Methods From February 2022 to April 2023,120 ICH patients who underwent treatment at our hospital were recruited as the ICH group.They were separated into a good prognosis group and a poor prognosis group based on the modified Rankin Scale(mRS)score After 6 months treatment Additionally,110 healthy individuals who underwent physical examination at our hospital were included as the control group.Clinical data of patients were collected and analyzed.Enzyme linked immunosorbent assay(ELISA)was applied to detect serum levels of tumor necrosis factor-α(TNF-α)and vascular endothelial growth factor(VEGF)indicators.Real-time fluorescence quantitative polymerase chain reaction(qRT-PCR)was applied to detect the expression levels of serum miR-144-3p and miR-126-3p.Pearson method was applied to analyze the correlation between serum miR-144-3p,miR-126-3p,TNF-α,and VEGF levels in ICH patients.Multivariate Logistic regression was applied to analyze the factors affecting the prognosis of ICH patients.ROC curve was applied to analyze the predictive value of serum miR-144-3p and miR-126-3p for the prognosis of ICH patients.Results In the control group,the serum miR-144-3p was 1.02±0.02,the TNF-α was(19.15±6.79)pg/ml,the VEGF level was(1.05±0.18)ng/ml,and the serum miR-126-3p level was 1.04±0.05.The values in the ICH group were 2.12±0.23,(48.32±8.43)pg/ml,(6.56±1.49)ng/ml,and(0.53±0.12),respectively.There was a statistically significant difference between the two groups(P＜0.05).Pearson analysis results showed that serum miR-144-3p was positively correlated with TNF-α and VEGF levels in ICH patients(r=0.496,0.542,P＜0.05),while serum miR-126-3p was negatively correlated with TNF-α and VEGF levels(r=-0.493,-0.526,P＜0.05).There were significant differences in the serum levels of miR-144-3p,miR-126-3p,TNF-α,VEGF,and NIHSS score between different prognostic groups(P＜0.05).Multivariate logistic analysis revealed that serum miR-144-3p,miR-126-3p,TNF-α,and VEGF were all factors affecting the poor prognosis of ICH patients(P＜0.05).The area under the curve(AUC)of serum miR-144-3p,miR-126-3p,and combined prediction of prognosis in ICH patients was 0.851,0.886,and 0.952,respectively,the combined prediction of the two was more valuable(Zcombination-miR-144-3p=3.371,Zcombination-miR-126-3p=2.791,P＜0.05).Conclusion The expression of miR-144-3p in the serum of ICH patients increases,while the expression of miR-126-3p decreases.The two may serve as biological markers for predicting the prognosis of ICH patients,and the combination of the two is more valuable in predicting the prognosis of ICH patients.

Objective To investigate the expression and clinical significance of serum microRNA-144-3p(miR-144-3p)and microRNA-126-3p(miR-126-3p)in patients with intracerebral hemorrhage(ICH).Methods From February 2022 to April 2023,120 ICH patients who underwent treatment at our hospital were recruited as the ICH group.They were separated into a good prognosis group and a poor prognosis group based on the modified Rankin Scale(mRS)score After 6 months treatment Additionally,110 healthy individuals who underwent physical examination at our hospital were included as the control group.Clinical data of patients were collected and analyzed.Enzyme linked immunosorbent assay(ELISA)was applied to detect serum levels of tumor necrosis factor-α(TNF-α)and vascular endothelial growth factor(VEGF)indicators.Real-time fluorescence quantitative polymerase chain reaction(qRT-PCR)was applied to detect the expression levels of serum miR-144-3p and miR-126-3p.Pearson method was applied to analyze the correlation between serum miR-144-3p,miR-126-3p,TNF-α,and VEGF levels in ICH patients.Multivariate Logistic regression was applied to analyze the factors affecting the prognosis of ICH patients.ROC curve was applied to analyze the predictive value of serum miR-144-3p and miR-126-3p for the prognosis of ICH patients.Results In the control group,the serum miR-144-3p was 1.02±0.02,the TNF-α was(19.15±6.79)pg/ml,the VEGF level was(1.05±0.18)ng/ml,and the serum miR-126-3p level was 1.04±0.05.The values in the ICH group were 2.12±0.23,(48.32±8.43)pg/ml,(6.56±1.49)ng/ml,and(0.53±0.12),respectively.There was a statistically significant difference between the two groups(P＜0.05).Pearson analysis results showed that serum miR-144-3p was positively correlated with TNF-α and VEGF levels in ICH patients(r=0.496,0.542,P＜0.05),while serum miR-126-3p was negatively correlated with TNF-α and VEGF levels(r=-0.493,-0.526,P＜0.05).There were significant differences in the serum levels of miR-144-3p,miR-126-3p,TNF-α,VEGF,and NIHSS score between different prognostic groups(P＜0.05).Multivariate logistic analysis revealed that serum miR-144-3p,miR-126-3p,TNF-α,and VEGF were all factors affecting the poor prognosis of ICH patients(P＜0.05).The area under the curve(AUC)of serum miR-144-3p,miR-126-3p,and combined prediction of prognosis in ICH patients was 0.851,0.886,and 0.952,respectively,the combined prediction of the two was more valuable(Zcombination-miR-144-3p=3.371,Zcombination-miR-126-3p=2.791,P＜0.05).Conclusion The expression of miR-144-3p in the serum of ICH patients increases,while the expression of miR-126-3p decreases.The two may serve as biological markers for predicting the prognosis of ICH patients,and the combination of the two is more valuable in predicting the prognosis of ICH patients.

Objective To explore the risk factors of clopidogrel resistance in elderly patients with acute myocardial infarction(AMI)in order to provide personalized medication plans.Methods A prospective trial was conducted on 472 elderly AMI patients undergoing coronary stent placement in No.901 Hospital of Joint Logistics Support Force of PLA and Hangzhou Special Service Conva-lescent Center of Air Force from January 2018 to December 2022.All patients received clopidogrel for antiplatelet postoperatively,and after 7 consecutive days of administration,peripheral venous blood samples were collected to observe whether the patient had resistance to clopidogrel and to measure the concentration of active metabolites of clopidogrel and the maximum platelet aggrega-tion ratio(MARAA)of arachidonic acid induced platelets.According to MARAA,they were divid-ed into a clopidogrel resistant group(MARAA≥55％,142 cases)and a clopidogrel sensitive group of(＜55％,330 cases).The clinical characteristics were compared between the two groups,and multivariate logistic regression analysis was used to identify the risk factors for clopidogrel resistance.The impact of clopidogrel resistance on major adverse cardiovascular events was ana-lyzed.Results The clopidogrel resistant group had significantly higher MARAA level,decrease in the concentration of clopidogrel active metabolites,higher BMI,and larger ratios of obesity,CYP2C19*2 mutation,diabetes,hyperlipidemia and administration of hypoglycemic drugs when compared with the clopidogrel sensitive group(P＜0.01).Obesity,diabetes,hyperlipidemia and CYP2C19*2 mutation were risk factors for clopidogrel resistance in elderly AMI patients(OR=2.036,95％CI:1.282-3.235;OR=2.795,95％CI:1.803-4.334;OR=2.125,95％CI:1.355-3.331;OR=4.881,95％CI:2.807-8.486).The incidence of major adverse cardiovascular events was notably higher in the clopidogrel resistant group than the sensitive group(11.27％vs 4.55％,P＜0.01).After a prediction model was constructed with R4.0.3 statistical software,330 cases randomly selected from the dataset were assigned into a training set,and the remaining 142 cases into a validation set.The AUC value of the training set and the validation set was 0.750 and 0.780,respectively.Hosmer-Lemeshow Goodness of Fit test indicated that the model had good re-liability and predictive value(Chi-square=18.907,P=0.215).Conclusion Obesity,diabetes,hy-perlipidemia and CYP2C19*2 mutation are risk factors of clopidogrel resistance in elderly AMI patients,and clopidogrel resistance may lead to poor prognosis.

Objective To explore the risk factors of clopidogrel resistance in elderly patients with acute myocardial infarction(AMI)in order to provide personalized medication plans.Methods A prospective trial was conducted on 472 elderly AMI patients undergoing coronary stent placement in No.901 Hospital of Joint Logistics Support Force of PLA and Hangzhou Special Service Conva-lescent Center of Air Force from January 2018 to December 2022.All patients received clopidogrel for antiplatelet postoperatively,and after 7 consecutive days of administration,peripheral venous blood samples were collected to observe whether the patient had resistance to clopidogrel and to measure the concentration of active metabolites of clopidogrel and the maximum platelet aggrega-tion ratio(MARAA)of arachidonic acid induced platelets.According to MARAA,they were divid-ed into a clopidogrel resistant group(MARAA≥55％,142 cases)and a clopidogrel sensitive group of(＜55％,330 cases).The clinical characteristics were compared between the two groups,and multivariate logistic regression analysis was used to identify the risk factors for clopidogrel resistance.The impact of clopidogrel resistance on major adverse cardiovascular events was ana-lyzed.Results The clopidogrel resistant group had significantly higher MARAA level,decrease in the concentration of clopidogrel active metabolites,higher BMI,and larger ratios of obesity,CYP2C19*2 mutation,diabetes,hyperlipidemia and administration of hypoglycemic drugs when compared with the clopidogrel sensitive group(P＜0.01).Obesity,diabetes,hyperlipidemia and CYP2C19*2 mutation were risk factors for clopidogrel resistance in elderly AMI patients(OR=2.036,95％CI:1.282-3.235;OR=2.795,95％CI:1.803-4.334;OR=2.125,95％CI:1.355-3.331;OR=4.881,95％CI:2.807-8.486).The incidence of major adverse cardiovascular events was notably higher in the clopidogrel resistant group than the sensitive group(11.27％vs 4.55％,P＜0.01).After a prediction model was constructed with R4.0.3 statistical software,330 cases randomly selected from the dataset were assigned into a training set,and the remaining 142 cases into a validation set.The AUC value of the training set and the validation set was 0.750 and 0.780,respectively.Hosmer-Lemeshow Goodness of Fit test indicated that the model had good re-liability and predictive value(Chi-square=18.907,P=0.215).Conclusion Obesity,diabetes,hy-perlipidemia and CYP2C19*2 mutation are risk factors of clopidogrel resistance in elderly AMI patients,and clopidogrel resistance may lead to poor prognosis.

Objective:To assess and compare the performance of limiting-antigen avidity enzyme immunoassay (LAg-Avidity EIA) and pooling PCR in the surveillance for recent infection rates of HIV-1 in men who have sex with men (MSM).Methods:Blood samples were collected from MSM selected through snowball sampling method in sentinel surveillance in 13 prefectures of Yunnan province from 2016 to 2017. The samples were tested for HIV-1 antibody. The confirmed positive samples were tested by LAg-Avidity EIA. The negative samples were tested by pooling PCR. The recent infection rates of HIV-1 were estimated by the algorithm based on LAg-Avidity EIA and pooling PCR respectively. The two results were compared.Results:During 2016-2017, a total of 5 363 blood samples were collected from MSM, in which 407 samples were HIV-1 positive (including 177 positive tested previously) and 4 956 samples were HIV-1 negative. A total of 211 samples(91.7%) were tested by LAg-Avidity EIA, 69 were confirmed to be recent infections. A total of 4 469 samples were tested by pooling PCR, 8 were confirmed to be acute infections. The recent infection rates of HIV-1 from 2016 to 2017 estimated by LAg-Avidity EIA were 3.36% and 4.84%, and the recent infection rates estimated by pooling PCR were 3.27% and 3.02% respectively. The differences in recent infection rates of HIV-1 estimated by the two algorithms were not significant.Conclusions:The recent infection rates of HIV-1 estimated by LAg-Avidity EIA and pooling PCR in sentinel surveillance in MSM in Yunnan had good consistency from 2016 to 2017. Using the two methods might have a better stability in continuous surveillance for recent infection rates of HIV-1.

Objective:To understand the characteristics of HIV-1 genotypes and drug resistance among men who have sex with men in Kunming in 2018.Methods:A total of 193 plasma samples were collected from the newly reported HIV-1 infected MSM in Kunming from January to December 2018. Viral RNA was extracted, and the gag, pol, env gene segments were amplified by nested PCR. HIV-1 genotypes and drug resistance were also analyzed. Subsequently, the evolutionary characteristics of CRF55_01B and CRF68_01B among MSM in Kunming were analyzed by Bayesian Markov Chain Monte Carlo method. Results:Multiple HIV-1 genotypes were identified among these 193 samples, including CRF07_BC (39.4%, 76/193), CRF01_AE (34.2%, 66/193), unique recombinant forms (URFs) (20.2%, 39/193), CRF08_BC (3.1%, 6/193), CRF55_01B (1.6%, 3/193), subtype B (1.0%, 2/193) and CRF68_01B (0.5%, 1/193). Results from the Bayesian evolutionary analysis showed that CRF55_01B started to spread locally after being imported from other provinces, while CRF68_01B was likely to have been brought in from the eastern provinces of China. Prevalence of HIV-1 drug resistant strains was 2.6%(5/190) before antiviral treatment, with mutation rates resistant to non-nucleoside reverse transcriptase inhibitors being the highest (2.1%, 4/190) among MSM in Kunming, 2018.Conclusion:The diversity of HIV-1 was increasing among MSM in Kunming. Although the resistance rate on pretreatment drug was relatively low, the emergence of multiple resistant strains to first-line antiviral drugs posed a challenge to antiretroviral therapy, in Kunming.

Objective To investigate the efficacy of leflunomide combined with prednisone in the induction therapy of proliferative lupus nephritis (LN).Methods A prospective,multicenter,randomized controlled clinical trial was conducted in patients with biopsy-proved proliferative lupus nephritis recruited from 15 renal centers from 2013 to 2015.Patients were randomized to two groups.Oral leflunomide or intravenous cyclophosphamide was given to patients in each group.Both groups received a tapering course of oral prednisone therapy.All patients were followed up for 24 weeks.The blood biochemistry,urine index,clinical curative effect and adverse reaction were recorded and analyzed statistically.Results A total of 100 patients were enrolled in this clinical trial,including 48 patients in leflunomide group and 52 patients in cyclophosphamide group.After 24 weeks,the overall response rate was 79％ (95％ CI 67％-90％) in the leflunomide group and 69％ (95％ CI 56％-82％) in the cyclophosphamide group.23％ (95％CI 11％-35％) of patients in leflunomide group showed complete remission compared with 27％ (95％CI 24％-30％) in cyclophosphamide group (P=0.35).The levels of 24-hr urine protein excretion,SLEDAI and anti-dsDNA antibody titers were decreased in patients treated with leflunomide group after 24-weeks treatment.And the levels of serum albumin and complement 3 after treatment were significantly higher compared with these before treatment.There was also no significant difference in changes of 24-hr urine protein excretion,SLEDAI score,anti-dsDNA antibody titers,serum albumin and complement C3 levels after treatment between two groups.Incidence of adverse events did not differ between the leflunomide and cyclophosphamide group.Conclusions Leflunomide combined with prednisone showed same efficacy compared with cyclophosphamide as induction therapy for lupus nephritis.Leflunomide might be an useful medicine in the induction therapy of lupus nephritis.

Objective To evaluate the accuracy and feasibility of primary total knee arthroplasty (TKA) assisted by the self-made extramedullary osteotomy template on distal femur alignment.Methods We retrospectively analyzed the clinical data of 40 patients with osteoarthritis or rheumatoid undergoing primary TKA from September 2015 to March 2016.All patients were divided into two groups,extramedullary group and intramedullary group.Extramedullary group had 20 patients (4 males and 16 females) aged 65.1±6.9 years (range 51-75).Intramedullary group had 20 patients (3 males and 17 females) aged 65.7±7.9 years (range 48-75).The blood loss volume,drainage in operation,postoperative range of motion (ROM) at 1 week and 2 weeks,deviation between the ideal value and preoperative hip-knee-ankle (HKA) angle,coronal and sagittal angle of the femoral prosthesis were compared within the two groups.Results The age,gender,body mass index,deviation between the ideal value and preoperative HKA angle,Hospital for Special Surgery (HSS) scoring system,ROM of knee were not significantly different between the two groups.The operation time was 97.4± 14.0 min in extramedullary group and 111.7±9.9 min in intramedullary group (P ＜ 0.05).The blood loss was 71.8± 14.0 ml in extramedullary group and 111.7± 10.0 ml in intramedullary group (P ＜ 0.05),while the drainage volume was 167.0±74.5 ml in extramedullary group and 243.2±91.6 ml in intramedullary group (P＜ 0.05).The postoperative mean deviation of the HKA angle in extramedullary group (2.37°±0.73°) was smaller than that in intramedullary group (3.26°±1.42°).Furthermore,the coronal alignment of the femoral prosthesis in extramedullary group (89.70°±1.91°) was larger than that in intramedullary group (87.69°±2.39°).The sagittal alignment of the femoral prosthesis in extramedullary group (90.03°±2.62°) was also significantly larger than that in intramedullary group (88.07°±2.43°,P ＜ 0.05).The postoperative ROM of knee at 1 and 2 week in the extramedullary group were 101.75°±7.48° and 114.00°±7.88° respectively,while those in the intramedullary group were 101.25°±8.41° and 114.25°±8.78°.There was no statistically different between the two groups.There was no intraoperative and postoperative early complications reported in the two groups.Conclusion Although the primary TKA assisted by the selfmade extramedullary osteotomy template on distal femur alignment can shorten operation time,decrease the blood loss and increase the accuracy of coronal and sagittal alignment,the HSS score and ROM of knee are similar as intramedullary method.

BACKGROUND: It remains poorly understood whether anterior column quadrilateral wing plate exists to solve intraoperative multiple plastic and quadrilateral in vivo shift for treating acetabular anterior column and acetabular quadrilateral body fractures.OBJECTIVE: To figure out the promising application on measurement of anatomical character parameters when designing acetabular anterior column and acetabular quadrilateral body using Mimics software. METHODS: 60 pelvic CT scan data were collected and three-dimensionally reconstructed by Mimics software. The following anatomical character parameters were measured, including the angle between plane of arcuate line of true pelvis and plane of quadrilateral surface, the four boundary lines of quadrilateral body, and the thickness of substance of bone in quadrilateral region. The projection curve on quadrilateral surface of acetabular margin and dangerous zone for screw placement were both drew. Above all, the study attempted to find out the proper safe entry point of quadrilateral screw and to measure their leaning inside angles.RESULTS AND CONCLUSION: (1) The angle between plane of arcuate line of true pelvis and plane of quadrilateral surface was not significantly different between males and females. (2) The minimum thickness of quadrilateral body in males was larger than that in females. (3) The maximum leaning angle flapper plate screw P1 and P2 for quadrilateral body was significantly smaller in males than in females, but that of screw P3 was not significantly different between males and females. (4) The application of Mimics software made it easier, more intuitive and more practical for the design or development of new plate for acetabular anterior column and acetabular quadrilateral body. The common points and difference between acetabular anterior column and acetabular quadrilateral body could be specifically described by the new anatomical character parameters, which are defined by bone surface features of pelvis.