Objective To investigate the predictive value of serum homocysteine(HCY)and lipoprotein(a)[Lp(a)]in autologous arteriovenous fistula(AVF)failure in patients undergoing maintenance hemodialy-sis(MHD).Methods A total of 175 patients with MHD admitted to the hospital from January to December 2022 were selected as the observation group,among them,103 patients without AVF failure were selected as observation group 1,and 72 patients with AVF failure were selected as observation group 2.175 healthy indi-viduals who underwent physical examinations at the outpatient examination center of the hospital during the same period were selected as the control group.Enzyme-linked immunosorbent assay was used to detect the levels of HCY and Lp(a).Pearson method was used to analyze the correlation between HCY,Lp(a)with clin-ical indicators.Multivariate Logistic regression analysis was performed to analyze the influencing factors of AVF failure in MHD patients.Receiver operating characteristic(ROC)curve was plotted to analyze the pre-dictive value of serum HCY and Lp(a)for AVF failure in MHD patients.Results Compared with the control group,the serum levels of HCY and Lp(a)in observation group 1 were increased(P<0.05).Compared with the control group and observation group 1,the serum levels of HCY and Lp(a)in observation group 2 were in-creased(P<0.05).The serum levels of HCY and Lp(a)in observation group 2 were negatively correlated with ultrafiltration amount(P<0.05),and HCY and Lp(a)were positively correlated with parathyroid hor-mone(PTH),blood phosphorus(P),uric acid(UA)(P<0.05).Multivariate Logistic regression analysis showed that HCY,Lp(a),PTH,P,UA,diabetic nephropathy,duration of endovascular fistula use≥12 months,duration of puncture point compression≥30 min,and arteriovenous internal diameter<2 mm and vascular stenosis were the risk factors for AVF failure in MHD patients(P<0.05),and ultrafiltration a-mount was a protective factor for AVF failure in MHD patients(P<0.05).ROC curve results showed that the area under the curve of HCY and Lp(a)alone and in combination in the prediction of AVF failure in MHD patients were 0.822,0.820 and 0.908,respectively(Zcombination vs.HCY=3.144,Zcombination vs.Lp(a)=2.925,P<0.05).Conclusion The serum levels of HCY and Lp(a)in MHD patients with AVF failure are increased.They are the influencing factors of AVF failure in MHD patients,and the value of the combination of the two for pre-dicting AVF failure in MHD patients is relatively high.

Objective To investigate the mechanical responses of mitochondrial morphology to extracellular matrix stiffness in human mesenchymal stem cells(hMSCs)and the role of AMP-activated protein kinase(AMPK)in the regulation of mitochondrial mechanoresponses.Methods Two polyacrylamide(PAAm)hydrogels,a soft one with a Young's modulus of 1 kPa and a stiff one of 20 kPa,were prepared by changing the monomer concentrations of acrylamide and bis-acrylamide.Then,hMSCs were cultured on the soft and stiff PAAm hydrogels and changes in mitochondrial morphology were observed using a laser confocal microscope.Western blot was performed to determine the expression and activation of AMPK,a protein associated with mitochondrial homeostasis.Furthermore,the activation of AMPK was regulated on the soft and stiff matrixes by AMPK activator A-769662 and the inhibitor Compound C,respectively,to observe the morphological changes of mitochondria.Results The morphology of the mitochondria in hMSCs showed heterogeneity when there was a change in gel stiffness.On the 1 kPa soft matrix,74%mitochondria exhibited a dense,elongated filamentous network structure,while on the 20 kPa stiff matrix,up to 63.3%mitochondria were fragmented or punctate and were sparsely distributed.Western blot results revealed that the phosphorylated AMPK(p-AMPK)/AMPK ratio on the stiff matrix was 1.6 times as high as that on the soft one.Immunofluorescence assay results revealed that the expression of p-AMPK was elevated on the hard matrix and showed nuclear localization,which indicated that the activation of intracellular AMPK increased continuously along with the increase in extracellular matrix stiffness.When the hMSCs on the soft matrix were treated with A-769662,an AMPK activator,the mitochondria transitioned from a filamentous network morphology to a fragmented morphology,with the ratio of filamentous network decreasing from 74%to 9.5%.Additionally,AMPK inhibition with Compound C promoted mitochondrial fusion on the stiff matrix and significantly reduced the generation of punctate mitochondria.Conclusion Extracellular matrix stiffness regulates mitochondrial morphology in hMSCs through the activation of AMPK.Stiff matrix promotes the AMPK activation,resulting in mitochondrial fission and the subsequent fragmentation of mitochondria.The impact of matrix stiffness on mitochondrial morphology can be reversed by altering the level of AMPK phosphorylation.

Objective:To investigate the early- and mid-term clinical, functional and radiographic outcomes of patellofemoral arthroplasty (PFA).Methods:A retrospective analysis was conducted in 64 patients (80 knees) who suffered from severe patellofemoral osteoarthritis (PFOA) and underwent PFA from January 2013 to December 2020. These patients were aged 60.50±8.82 (range from 27 to 82) years, including 9 males (12 knees) and 55 females (68 knees). All enrolled individuals presented typical PFOA. Unilateral PFA was performed in 48 cases, bilateral PFA in 16 cases, including one-stage PFA in 9 cases and two-stage PFA in 7 cases. The visual analogue scale (VAS), Hospital for Special Surgery (HSS) knee score and Oxford knee score (OKS) of patients with more than 5 years' follow-up were assessed to evaluate the clinical effects of PFA at the time before surgery, 1 year and 5 years after surgery. In addition, the patellar tilt angle (PTA) and hip-knee-ankle (HKA) angle were measured and analyzed to evaluate the improvement of patellar tracking and progression of tibiofemoral osteoarthritis, based on axial X-ray imaging (skyline view) of knee and the full length standing X-ray imaging of the lower limbs at before surgery and 5 years after surgery. Meanwhile, the complications of all patients that related to the operation were recorded.Results:A total of 64 patients were followed up for 4.31±1.79 (range, 1.5 to 8.2) years. Twenty-five patients (32 knees) who followed up more than 5 years were analyzed. The VAS, HSS and OKS improved from 5.91±0.82, 68.06±6.03 and 21.22±3.46 preoperatively to 0.88±1.01, 90.09±3.30 and 39.06±3.37 at 1 year after surgery, and to 0.41±0.76, 94.53±2.99 and 42.13±3.17 at 5 years after surgery, respectively ( F=89.38, 81.47, 56.73, P<0.001). Additionally, comparing to the preoperative radiological data, the patellar tract was improved with the PTA decreased from 8.21°±3.14° preoperatively to 3.58°±4.48°at 5 years after surgery ( t=4.96, P<0.001). The HKA angle changed from 179.01°±1.43° preoperatively to 178.77°±1.67° at 5 years follow up ( t=1.71, P=0.096). There was no case of prosthesis loosening or wear and no case of obvious progression of tibiofemoral osteoarthritis that needed revision in all patients. Conclusion:Satisfied early- and mid-term clinical outcomes could be achieved by PFA in treating severe PFOA patients. PFA could relieve pain and improve function of knee joint.

Objective To study the effects of selecting different fixing segments on biomechanical characteristics of the spine during the treatment of early onset scoliosis（EOS） by growing rod technique. Methods By using finite element method, four spine models (C6-S1 segments) fixed by growing rod were established: preoperative model, T1-L4 fixed model, T2-L4 fixed model, T3-L4 fixed model. Then 7 N·m torque load and 1 rad angular displacement load were applied on superior surface of C6 segment to analyze biomechanical characteristics for adjacent structure of the fixed vertebral body. Results The whole spinal range of motion (ROM) decreased significantly after operation. When the T2-L4 segment was fixed, the spine activity was mostly restricted, the compensatory activity of adjacent vertebrae increased significantly, and the intervertebral disc stress increased significantly. Conclusions When T2 segment is selected as the upper instrumented segment, the risk of proximal junctional kyphosis and spinal degeneration is the highest, which should be avoided in clinical surgery.

Objective To investigate the clinical feature and treatment outcome of paediatric posttraumatic endophthalmitis.Methods A retrospective case study was performed.Twenty-six paediatric posttraumatic endophthalmitis children with 26 eyes were enrolled in Shandong Eye Hospital from April 2014 to April 2017.The clinical features,causes of trauma,time and mode of treatment,complications and visual acuity were analyzed.The subjects were graded according to the prognostic status,and the prognosis of the children was compared among different treatment time,vitrectomy time,operation frequency and antibiotic application.Results Of 26 cases,including 20 males and 6 females,aged from 1 year to 13 years,the average age was (6.56±3.25) years.The subjects were divided into infant group (2 cases,7.69％),preschool group (10 cases,38.46％) and school age group (14 cases,53.85％).The main cause of injury was wire,accounting for 34.62％ (9/26).Syringe needles accounted for 15.38％ (4/26).Fireworks accounted for 11.54％ (3/26).All of the 26 cases received vitrectomy,24 cases combined with lens extraction (92.31％).Among the 26 cases,8 cases had no primary visual acuity record;in the remaining 18 cases,the visual acuity at last follow-up was significantly improved when compared with the preoperative primary visual acuity (x2 =7.385,P =0.033).The positive rate of pathogenic bacteria culture in aqueous humor and vitreous humor was 23.08％ (6/26),gram-positive cocci was the main pathogenic bacteria of posttraumatic endophthalmitis,which account for 83.3％ (5/6).The prognostic grade was grade 1 in 15 cases (57.7％),grade 2 in 7 cases (26.9％) and grade 3 in 4 cases (15.4％).There were significant differences in the number of prognostic grading cases among children with different hospitalizing time or vitrectomy time (all at P＜0.05).The hospitalizing time,time of vitrectomy,number of operations and systemic application of antibiotics were positively correlated with the prognosis grade (rs =0.580,0.414,0.428,0.535;all at P ＜ 0.05).Conclusions Children with posttraumatic endophthalmitis should undergo vitrectomy as early as possible,which can receive better prognosis.

Objective To explore the effect of positive end expiratory pressure (PEEP) on arterial oxygenation and intrapulmonary shunt during one-lung ventilation (OLV) and pulmonary function during perioperation. Methods Forty patients with normal pulmonary function,ASA I - II :scheduled for pulmonary lobectomy, were divided into control group and PEEP group by random digits table with 20 cases each. Patients were induced by double-lumen tubes under intravenous anesthesia and were received 10 ml/kg tidal volume, 12 frequents/min breathing rate during the two-lung ventilation (TLV), secondary reduced to 6 ml/kg tidal volume, 16-18 frequents/min breathing rate without PEEP (control group) or with 5 cm H2O cm H2O =0.098 kPa) PEEP (PEEP group) during OLV.Hemodynamics and respiratory mechanical parameters were continuously monitored, lung function before operation and at 72 h after operation was detected. Results Compared to before OLV,arterial oxygen tension (PaO2), arterial oxygen saturation (SpO2), oxygenation index (OI) were decreased and intrapulmonary shunt ratio (Qs/Qt) was increased in control group and PEEP group at 30 min after OLV (P < 0.01 or < 0.05). However,PaO2 and SpO2 and OI were higher and Qs/Qt was lower in PEEP group than that in control group at the same time point (P<0.05). In addition, FEV1%, FVC% and FEV1/FVC were (121.8 ± 25.0% ,(117.2 ± 24.3)% , (87.6 ± 15.7)%before operation and (84.9 ± 21.6)%, (77.2 ± 18.3)% , (70.5 ± 12.5)% at 72 h after operation respectively in control group, (116.9 ±24.5)% , (112.1 ±23.6)% , (85.3 ± 13.8)% before operation and (96.3 ± 20.4)%, (88.1 ± 19.8)% , (78.4 ± 10.2)% at 72 h after operation respectively in PEEP group. Although decreased in control group and PEEP group at 72 h after operation comparing with preoperation (P< 0.01 or < 0.05 ), FEV1%, FVC% and FEV1/FVC were higher in PEEP group than those in control group at 72 h after operation (P<0.05). Conclusion Appropriate PEEP increases arterial oxygenation,reduces Qs/Qt and improves pulmonary function during OLV,reduces the risk of hypoxernia and lung injury induced by OLV during perioperation.