BACKGROUND:At present,there is still controversy in clinical practice about the choice of internal fixation of Pauwels type Ⅲ femoral neck fracture,and the selection of internal fixation that provides stable fixation strength is the key basis for achieving Pauwels type Ⅲ fracture fixation. OBJECTIVE:The three-dimensional finite element analysis method was used to test the difference in biomechanical strength of three types of internal fixation in Pauwels type Ⅲ femoral neck fracture,which provided a reference for its clinical treatment. METHODS:Using the CT data of the left femur of a healthy male volunteer,a complete femur and its cancellous bone were reconstructed in Mimics software,and Geomagic studio software was used for reverse modeling.Cannulated compression screw,dynamic hip screw,and femoral neck system were created in UG-NX software.Three kinds of internal fixation models were assembled on the femur model,and Pauwels type Ⅲ femoral neck fracture was simulated by Hypermesh software.Finally,Abaqus software was used to carry out finite element experimental analysis to analyze and compare the stress distribution,stress peak,strain,and displacement distribution caused by fixed femoral neck fracture of different internal fixation systems. RESULTS AND CONCLUSION:(1)The stress of the proximal femur bone mass was mainly distributed in the area below the femoral neck near the fracture end,with the highest stress peak in the dynamic hip screw group and the smallest in the femoral neck system group.(2)The stress distribution of the internal fixation device was mainly concentrated on the screw surface near the fracture line,with the highest stress peak in the femoral neck system group and the smallest in the dynamic hip screw group.(3)The main strain field of the proximal femur bone mass was distributed in the upper surface area where the bone and screw contacted,and the yield strain was the smallest in the femoral neck system group and the largest in the cannulated compression screw group.(4)The main strain field of the internal fixation device model was distributed on the upper surface of the femoral neck screw,with the yield strain being the smallest in the femoral neck system group and the largest in the cannulated compression screw group.(5)The displacement distribution values of femur,proximal bone mass,distal bone block,internal fixation device and internal fixation with the femur as a whole in the three femoral neck fracture internal fixation models decreased gradually from proximal to distal,and the peak displacement of the femoral neck system group was the largest and the lowest in the dynamic hip screw group.(6)The results showed that when the Pauwels type Ⅲ femoral neck fracture was fixed,the stress distribution of femoral neck system was more uniform,the mechanical conduction characteristics were better,and it was subjected to lower yield strain,higher stress and higher displacement.It has relatively better biomechanical stability and can provide a superior mechanical environment for fracture healing.

Objective To determine the improved effect of methylene blue(MB)on cognitive func-tion in brain-inflammatory-aging rats and investigate the underlying mechanism.Methods A total of 38 healthy 12-month-old SD rats were randomly divided into healthy control group,lipopo-lysaccharide(LPS)group,MB vehicle group and MB group,with 8 rats in the control and 10 rats in the other three groups.LPS was injected into the fourth ventricle with aid of a subcutaneous sustained release pump to establish a rat model of brain chronic inflammatory aging.MB of 0.5 mg/(kg·d)was added into the pump in the rats from the MB group.T-maze test and new object recognition test were employed to evaluate the learning and memory abilities of the rats.The acti-vation of microglia and astrocytes in the hippocampal CA1 region of the rats was detected by im-munofluorescence assay.The release of inflammatory factors IL-1β and IL-6 was measured by ELISA,and neuronal death in the CA1 region was assessed by neuronal nuclei(NeuN)fluores-cence staining.Results There was no significant difference in the exploration time for new and old objects between the LPS group and the MB solvent group(P＞0.05).The MB group spent significantly longer time in exploring the new objects than the old object(22.50±4.32 s vs 11.60± 3.01 s,P=0.000).The alternating selection rate of new arm and expression level of NeuN antigen were significantly decreased,and the expression levels of ionized calcium binding adaptor mole-cule-1(Iba-1)and glial fibrillary acidic protein(GFAP)and the contents of IL-1β and IL-6 were obviously increased(P＜0.05)in the LPS group and the MB vehicle group than the healthy con-trol group.Compared with the MB vehicle group,the MB group had notably increased alternating selection rate of new arms and higher NeuN expression level,and decreased Iba-1 and GFAP ex-pression and IL-1β and IL-6 contents(P＜0.05).Conclusion Subcutaneous administration of MB could significantly inhibit the damages of spatial learning and memory abilities in the LPS-induced brain chronic inflammatory aging rats.The mechanism may be closely associated with MB inhibi-ting inflammatory glial cells and protecting hippocampal pyramidal neurons.

Objective To explore the application value and related factors of serum carbonic anhydraseⅢ(CAⅢ)in the clinical diagnosis of mild to moderate Alzheimer disease(AD).Methods A total of 106 elderly patients initially diagnosed with mild to moderate AD at Huashan Hospital,Fudan University from October 2020 to November 2022 were enrolled as the AD group,and 89 healthy elderly people during the same period were enrolled as the control group.The serum biochemical indicators including liver and kidney function,blood lipids,blood glucose,folic acid and homocysteine were detected in both groups.Cognitive function was assessed by Mini-mental State Examination(MMSE).Patient Health Questionnaire-9(PHQ-9)and Generalized Anxiety Disorder-7(GAD-7)were used to assess psychological status.The activities of daily living(ADL)were assessed by modified Barthel Index(BI).Serum CAⅢlevels were measured by enzyme-linked immunosorbent assay(ELISA).Correlation analysis and multivariate linear regression analysis were used to identify factors influencing serum CAⅢlevels,and receiver operating characteristic(ROC)curve analysis was performed to evaluate the diagnostic value of serum CAⅢlevels in elderly patients with mild to moderate AD.Results The MMSE score of the AD group was significantly lower than that of the control group(P＜0.001),and the PHQ-9 and GAD-7 scores were significantly higher than those of the control group(P＜0.001).The serum CAⅢlevel in the AD group was significantly lower than that in the control group(P＜0.000 1).In patients with AD,serum CAⅢlevels in patients with a disease course＞3 years,accompanied by depression or anxiety,moderate AD,and serum creatinine≤111 μmol/L were significantly lower than those in patients with a disease course≤3 years,normal emotions,mild AD,and serum creatinine＞111 μmol/L(P＜0.05).Correlation analysis and multivariate linear regression analysis showed that serum CAⅢlevels were negatively correlated with disease duration,PHQ-9 score,GAD-7 scores and severity degree,positively correlated with serum creatinine level(P＜0.05).The PHQ-9 score,severity degree,and serum creatinine level were independent related factors for serum CAⅢlevel in mild to moderate AD elderly patients(P＜0.05).ROC curve result showed that the area under the curve(AUC)of serum CAⅢin diagnosing mild to moderate AD in elderly patients was 0.946,with sensitivity and specificity of 88.79% and 96.74%,respectively.Conclusions Serum CAⅢlevels in elderly patients with mild to moderate AD are higher than those in healthy individuals.Mild AD,without depressive mood,and elevated serum creatinine levels are related factors for elevated serum CAⅢlevels in elderly AD patients.Serum CAⅢmay serve as a novel biological marker for the diagnosis of mild to moderate AD in the elderly.

Objective To understand the genotyping of human immunodeficiency virus (HIV) co-infected hepatitis C virus (HCV) patients in Yunnan Province, and to analyze the differences in viral load, biochemical indicators, and blood routine indicators among different genotypes, in order to provide a laboratory basis for the diagnosis and clinical treatment of HIV/HCV co-infected patients. Methods From November 2022 to June 2023, the serum samples and basic information of patients diagnosed with HIV/HCV co-infection were collected in the antiviral outpatient clinic of Yunnan Provincial Hospital of Infectious Diseases. The HCV viral load was detected by one-step qRT-PCR amplification, the positive samples were sequenced, and genotyping was determined based on NS5 gene sequence. The differences in biochemical and blood routine indexes between HIV patients co-infected with different HCV genotypes and low/high viral loads were analyzed. Results A total of 126 HIV/HCV co-infected patients were collected, including 20 HCV genotype 1 (15.9%), 91 HCV genotype 3 (72.2%), and 15 HCV genotype 6 (11.9%). The maximum and minimum viral load of the three HCV genotypes were as follows: HCV type 1 (1.0×108, 4.8×104 IU/mL), HCV type 3 (2.2×108, 2.9×102 IU/mL), and HCV type 6 (8.1×107, 6.8×104 IU/mL). The results showed that there was no significant difference between HIV co-infection with different genotypes of HCV and three HIV treatment schemes, including nucleoside reverse transcriptase inhibitors+integrase strand transfer inhibitors (NRTIs+INSTIs), nucleoside reverse transcriptase inhibitors+non-nucleoside reverse transcriptase inhibitors (NRTIs+NNRTIs) and nucleoside reverse transcriptase inhibitors+protease inhibitor (NRTIs+PLs), and the viral load of patients (P>0.05). The analysis of biochemical indexes such as total bilirubin (TBIL), direct bilirubin (DBIL), alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine (CREA), and blood routine indexes such as white blood cell (WBC), red blood cell (RBC), hemoglobin (HGB), platelet (PLT), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) among different HCV genotypes and low/high viral loads showed that there was no significant difference in biochemical indexes and blood routine indexes between low/high viral loads of HIV co-infected HCV patients (P>0.05); however, the biochemical indicators TBIL, IBIL and MCHC were significantly different statistically between patients with genotype 3 HCV infection and those with genotype 1 HCV infection (P<0.05), while other biochemical and blood routine indexes were not statistically different among different HCV genotypes (P>0.05). Conclusions There are six subtypes of HCV co-infection in HIV patients in Kunming, Yunnan Province, including three genes of genotype 1, 3, and 6. Among them, genotype 3 HCV is the main prevalent genetic virus among HIV co-infected populations. The TBIL, IBIL and MCHC values of HIV patients co-infected with HCV type 3 are different from those infected with HCV type 1.

【Objective】 To investigate the effects of biomimetic bone trabecular with the same porosity and pore size and regular porous structure on the adhesion, proliferation, and differentiation of osteoblasts, so as to provide theoretical basis for the improvement of osseointegration performance of titanium alloy implants. 【Methods】 The biomimetic bone trabecular and regular porous structures with the same porosity and pore size were generated by computer-aided software, and then processed into disc-shaped Ti6Al4V scaffolds with a diameter of 10 mm and a height of 3 mm by selective laser melting technology. MC3T3-E1 cells, the precursor cells of mouse osteoblasts in the logarithmic growth phase, were seeded on two kinds of scaffolds and divided into biomimetic bone trabecular group and regular porous structure group. After 3 hours of culture, acridine orange staining and phalloidin /DAPI staining were used to evaluate the number of cell adhesion. After 3 days of culture, the scaffolds were examined by scanning electron microscopy to evaluate the adhesion state of cells. After 1, 3, and 5 days of culture, the scaffolds were taken for CCK8 detection to observe the proliferation of cells. After 7 and 14 days of differentiation, alkaline phosphatase (ALP) activity was detected. After 14 days of differentiation, the expressions of osteogenesis-related genes (ALP, OCN, RUNX2) were detected by RT-PCR. After 30 days of differentiation, the scaffolds were stained with alizarin red and 100 g/L cetylpyridinium chloride was used to dissolve mineralized nodules. Calcium salt deposition was qualitatively and quantitatively detected to evaluate cell differentiation. 【Results】 The results of acridine orange and phalloidin /DAPI staining showed that the biomimetic trabecular Ti6Al4V scaffold adhered to more MC3T3-E1 cells than the regular porous structure, and the cytoskeleton of the former scaffold was more densely distributed. The results of scanning electron microscopy showed that the pseudopodia of MC3T3-E1 cells on the biomimetic bone trabecular Ti6Al4V scaffold were longer and the extension state was better than that of the regular porous structure. CCK8 test showed that the proliferation of MC3T3-E1 cells on the biomimetic trabecular bone titanium alloy scaffold was significantly higher than that on the regular porous structure on the 3rd and 5th day, and the difference gradually increased with the increase of time, with statistical significance (P<0.05). The results of cell differentiation test showed that ALP activity on the bionic trabecular scaffold was higher than that on the regular porous structure (P<0.05). The expressions of osteogenic genes (ALP, OCN, RUNX2) in MC3T3-E1 cells on the biomimetic bone trabecular titanium alloy scaffold were significantly higher than those on the regular porous structure (P<0.05). After 30 days of induction, the amount of calcium salt deposited in the bionic trabecular titanium alloy scaffold was significantly larger than that in the regular porous structure (P<0.05). 【Conclusion】 The biomimetic bone trabecular with a porosity of 65% and an equivalent pore size of 600 μm is more conducive to the adhesion, proliferation and differentiation of mouse osteoblast precursor cells MC3T3-E1 on the titanium alloy scaffold than the regular porous structure with the same porosity and pore size. It is theoretically more conducive to improving the osseointegration performance of titanium alloy implants.

Objective:To investigate the drug resistance factors in postoperative gemci-tabine chemotherapy after radical resection of pancreatic cancer.Methods:The retrospective case-control study was constructed. The clinicopathological data of 255 patients with pancreatic cancer who were firstly admitted to the Department of Hepatobiliary Surgery of the First Affiliated Hospital of Xi ′an Jiaotong University from January 2018 to June 2021 were collected. There were 140 males and 115 females, aged (59±10)years. All patients underwent radical resection of pancreatic cancer and received postoperative gemcitabine-based adjuvant chemotherapy. Observation indicators: (1) follow-up; (2) postoperative chemotherapy; (3) drug resistance and changing of regimen; (4) factors influencing postoperative chemotherapy resistance. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the independent sample t test. Measurement data with skewed distribution were represented as M( Q1, Q3), and compari-son between groups was conducted using the Mann-Whitney U test. Count data were described as absolute numbers, and comparison between groups was conducted using the Pearson chi-square test. Univariate analysis was conducted using the corresponding statistical methods based on data type. Multivariate analysis was conducted using the Logistic regression model with forward method. Kaplan-Meier method was used to draw survival curve, and Log-Rank test was used for survival analysis. Results:(1) Follow-up. All 255 patients were followed up for 18.6(16.7,21.4)months. The median survival time of 255 patients was 18.2[95% confidence interval ( CI) as 15.8-20.6]months. (2) Postoperative chemotherapy. Of the 255 patients, there were 5 cases receiving postoperative chemotherapy as gemcitabine monotherapy, 167 cases receiving postoperative chemotherapy as the AG combination (gemcitabine plus albumin-bound paclitaxel), 74 cases receiving postoperative chemotherapy as the GS combination (gemcitabine plus S-1) and 9 cases receiving postoperative chemotherapy as the GP combination (gemcitabine plus platinum). (3) Drug resistance and changing of regimen. Of the 255 patients, 81 cases completed the course of postoperative chemotherapy and evaluation. Of the 81 patients, there were 18 cases with no recurrence or metastasis of tumor, 10 cases with tumor local recurrence, 40 cases with tumor lymph node metastasis or distant metas-tasis, 3 cases with tumor local recurrence combined with distant metastasis, 10 cases with elevation of CA19-9. Of the 81 patients, 18 cases responded to chemotherapy, 63 cases underwent resistant to chemotherapy, including 11 cases with primary resistance and 52 cases with acquired resistance. The 63 patients with chemotherapy resistance underwent changing of regimen. (4) Factors influencing postoperative chemotherapy resistance. Results of multivariate analysis showed that chemotherapy cycle<6 is an independent risk factor for postoperative chemotherapy resistance in patients ( hazard ratio=17.18, 95% CI as 2.07-142.28, P<0.05). Conclusion:Adjuvant chemotherapy cycle <6 is an independent risk factor for postoperative chemotherapy resistance for gemcitabine based chemo-therapy in pancreatic cancer patients receiving radical resection.

Ischemic stroke is one of the leading causes of death and disability worldwide. In Han dynasty， HUA Tuo proposed the original preventive medicine idea that "with good blood circulation， the disease cannot be born"， which opened a broad space for the cross-research of blood-related mechanical factors and pharmacology. In the pathogenesis of ischemic stroke， mechanical factors comprehensively affect the function and crosstalk of platelets and endothelial cells. In recent years， as the well-known effects on thrombosis and stroke， more attention has been paid to hemodynamic factors as the participants involved in pathological mechanisms and potential therapeutic targets of ischemic stroke. The mechanical force ion channel Piezo1 widely exists on the surface of many types of cells. Besides being regulated by chemical and endogenous substances， Piezo1 responds to different mechanical conditions， regulates the opening and closing of channels， and activates different downstream signaling pathways. Piezo1 is now regarded as an important connection between mechanical and biochemical signals. A variety of Chinese medicine can affect the activity of Piezo1 protein， which may prevent and treat thrombotic diseases such as ischemic stroke through Piezo1 protein. In this paper， the effects of Piezo1 protein on the physiological and pathological functions of endothelial cells and platelet under different mechanical conditions and the role of Piezo1 in the process of thrombosis were reviewed， as well as the effects of Chinese medicine， chemical medicine， and endogenous substances targeting Piezo1 channel. These could provide new ideas for further exploring the mechanisms of Chinese medicines in activating blood circulation， developing new drugs， and deepening biomechanical-pharmacology research.

Objective:To confirm the reuse of mismatched regenerated motor axons of brachial plexus and explore the effect of target organs on their regeneration in a rat model.Methods:This study was carried out between January 2021 and December 2021 at the research laboratory of the Department of Microsurgery, Orthopaedic Trauma and Hand Surgery, the First Affiliated Hospital of Sun Yat-sen University. Animals were randomly assigned into 2 groups, as a regeneration group (RGen) with 5 subgroups and a reuse group (RUs) with 3 subgroups. There were 6 rats per subgroup with 42 rats in total. It was observed that in the groups of RGen1-4, after the transection and suture of the musculocutaneous nerve, the motor axons of the proximal end could accurately grow into the distal corresponding endoneural tube. It was also observed that in the mismatched regenerated group, motor axons were the axons that grew into the endoneurial tube of the lateral forearm cutaneous nerve (LFCN), and other non-target organ contacts were made to the regenerated nerves after mismatch. It was specifically further divided into RGen1, the group without an organ for nerve to make contact with; RGen2, the group with skin as the target organ with nerves contact by neurorrhaphy; RGen3, the group with skin as the target organ with originally reserved natural nerve contact; RGen4, the group with muscle as the target organ with nerves contact by neurorrhaphy and RGen5, a control group. After 8 weeks, the positive area (PA), mean density (MD) and integral optical density (IOD) were measured, with AChE and ChAT fluorescence staining of the medial branch of LFCN, to evaluate the regenerated nerves after mismatch. Of the RUs group, firstly, the innervating branches of the flexor carpi radialis (FCR) were dissected and exposed, then further assigned according to initially innervated FCR (RUs1), contacted with regenerated nerves after mismatch (RUs2) and denervated (RUs3), respectively. After 8 weeks, compound muscle action potential (CMAP) and wet weight ratio of FCR were taken. Masson staining of FCR was also performed to evaluate muscle reinnervation by the regenerated nerves after mismatch. Data analysis with One-Way ANOVA and Bonferroni 0.05 indicated a statistically significant difference.Results:In the RGen groups, after AChE staining, the PA, MD and IOD of RGen3 and RGen4 were higher than that of RGen1 and RGen5, and PA of RGen4 were higher than that of RGen2, with a statistically significant difference ( P<0.05). After ChAT staining, the values of PA and IOD of RGen3 and RGen4 were higher than that of RGen1 and RGen5, and PA of RGen4 were higher than that of RGen2, with a statistically significant difference ( P<0.05). In the RUs, electrophysiological assessment showed that no CMAP was observed in RUs3, there was no significant difference in Latency of RUs1 and RUs2. The difference was statistically significant ( P<0.05). Wet weight rate of muscle of RUs1 (98.91%±3.86%) was higher than that of RUs3 (86.67%±4.68%) with a statistically significant difference ( P<0.01), but no significant difference when compared with RU2 (92.74%±3.88%). Masson staining showed that the CVF value of RUs2 (8.61%±1.16%) was significantly higher than that of RUs1 (3.17%±0.76%), and statistic significantly lower than that of RUs3 (16.44%±2.26%)( P<0.01). Conclusion:Target organ contact can promote the regenerated nerves after mismatched regeneration, and the muscle target organs exhibit greater facilitation than the cutaneous target organs. Besides, regenerated nerves after mismatch can establish effective innervation with muscle target organs, comfirming their effective reuse.

Objective:To investigate the preoperative risk factors affecting early extremity blood supply after repair of major arterial injury so as to provide clues for prevention of limb ischemia.Methods:The clinical data were retrospectively analyzed of the 139 patients (140 extremities) with major extremity arterial injury who had been admitted to Department of Microsurgery, Orthopaedic Trauma and Hand Surgery, The First Hospital Affiliated to Sun Yat-sen University from January 2003 to December 2019. There were 112 males and 27 females, with a mean age of 30 (20, 44) years. The primary outcome was the early status of blood supply to the injured extremity (48 hours after surgery). Univariate analysis was conducted of such factors as gender, age, ischemia time, injury mechanism, injury site, fracture, soft tissue lesion, and duration of surgery. The significant factors ( P<0.1) were then analyzed by logistic regression, and P<0.05 was considered statistically significant. Results:Ischemia happened in 44 (31.4%, 44/140) extremities within 48 hours after surgery. There were significant differences in injury mechanism, ischemia time, fracture, and soft tissue lesion between patients with and without postoperative extremity ischemia ( P<0.05). Logistic regression analysis indicated that blunt injury ( OR=5.639, 95% CI: 1.068 to 29.761, P=0.042) and soft tissue lesion ( OR=12.568, 95% CI: 3.402 to 46.431, P<0.001) were significant preoperative risk factors affecting the early blood supply after repair of major extremity arterial injury. Conclusion:As blunt injury and soft tissue defect are preoperative risk factors for early extremity ischemia after repair of major extremity arterial injury, surgeons should pay more attention to them when assessing patients and making repair protocols.

Ankle Injuries ; Fractures, Compression ; Humans ; Knee Injuries