Objective To investigate the biomechanical characteristics of Salto Talaris tibial components with different heights at the bone-prosthesis interface during different gait support phases after total ankle replacement.Methods An ankle joint model was reconstructed using a weight-bearing CT from a 61-year-old female patient with ankle arthritis,and Salto Talaris tibial components with different heights(5,7,9,11 mm)were modelled to simulate the loading of the tibial-prosthesis during four gait support phases,and to analyse the micromotion and stresses at the bone-prosthesis interface.Results The 11 mm and 9 mm models had a poorer prosthesis stability,with the peak micromotion exceeding 50 μm and the peak internal tibial stresses of 30.75 MPa and 29.86 MPa,respectively,which exceeded the yield stress of the cancellous bone.The tibial stresses of the 7 mm and 5 mm models were within reasonable ranges and the average peak micromotions were only 42.66 μm and 40.32 μm.In contrast,the initial stability of the 5 mm model prosthesis was the best.Conclusions For total ankle replacement with Salto prosthesis,the height of the tibial component should be chosen appropriately,and the optimal height was about 5 mm.Excessive flexion and extension activities of the ankle joint should be avoided to maintain the stability of the prosthesis after surgery.This study provides a theoretical basis for the improvement of the structural parameters of the Salto prosthesis,which is valuable for the selection of clinical surgical prostheses and helps to improve the results of total ankle replacement.

Creutzfeldt-Jakob disease(CJD)is a rapidly progressive and fatal neurodegenerative disorder caused by prions,with certain infectivity and iatrogenic transmission risks.With the rapid progress and application of new dia-gnostic biomarkers and detection methods,as well as the construction and improvement of surveillance and reporting systems,the detection of CJD in patients domestically and internationally has shown an increasing trend year by year.Due to its long incubation period and heterogeneity of early symptoms,early identification and diagnosis of the disease is difficult,increasing the risk of transmission within medical institutions.Currently,there is a lack of con-sensus on the infection prevention and control of CJD.In order to timely identify and diagnose CJD as well as effec-tively block its transmission in medical institutions,this consensus summarizes 15 clinical concerns and formulates 24 specific recommendations based on the latest domestic and international research findings and clinical evidence,as well as combines with clinical practice,aiming to standardize healthcare-associated infection prevention and control measures for CJD and reduce its transmission risk in medical institutions.

Objective To investigate the biomechanical characteristics of Salto Talaris tibial components with different heights at the bone-prosthesis interface during different gait support phases after total ankle replacement.Methods An ankle joint model was reconstructed using a weight-bearing CT from a 61-year-old female patient with ankle arthritis,and Salto Talaris tibial components with different heights(5,7,9,11 mm)were modelled to simulate the loading of the tibial-prosthesis during four gait support phases,and to analyse the micromotion and stresses at the bone-prosthesis interface.Results The 11 mm and 9 mm models had a poorer prosthesis stability,with the peak micromotion exceeding 50 μm and the peak internal tibial stresses of 30.75 MPa and 29.86 MPa,respectively,which exceeded the yield stress of the cancellous bone.The tibial stresses of the 7 mm and 5 mm models were within reasonable ranges and the average peak micromotions were only 42.66 μm and 40.32 μm.In contrast,the initial stability of the 5 mm model prosthesis was the best.Conclusions For total ankle replacement with Salto prosthesis,the height of the tibial component should be chosen appropriately,and the optimal height was about 5 mm.Excessive flexion and extension activities of the ankle joint should be avoided to maintain the stability of the prosthesis after surgery.This study provides a theoretical basis for the improvement of the structural parameters of the Salto prosthesis,which is valuable for the selection of clinical surgical prostheses and helps to improve the results of total ankle replacement.

Creutzfeldt-Jakob disease(CJD)is a rapidly progressive and fatal neurodegenerative disorder caused by prions,with certain infectivity and iatrogenic transmission risks.With the rapid progress and application of new dia-gnostic biomarkers and detection methods,as well as the construction and improvement of surveillance and reporting systems,the detection of CJD in patients domestically and internationally has shown an increasing trend year by year.Due to its long incubation period and heterogeneity of early symptoms,early identification and diagnosis of the disease is difficult,increasing the risk of transmission within medical institutions.Currently,there is a lack of con-sensus on the infection prevention and control of CJD.In order to timely identify and diagnose CJD as well as effec-tively block its transmission in medical institutions,this consensus summarizes 15 clinical concerns and formulates 24 specific recommendations based on the latest domestic and international research findings and clinical evidence,as well as combines with clinical practice,aiming to standardize healthcare-associated infection prevention and control measures for CJD and reduce its transmission risk in medical institutions.

Purpose The current study aims to elucidate the interrelationships among IREB2,FBXL5,iron ho-meostasis,and the therapeutic efficacy of neoadjuvant chemotherapy.Methods A total of 97 samples,classified into colorectal cancer neoadjuvant chemotherapy-resistant and-sensitive groups,along with their corresponding paracancer-ous normal mucosa were collected.The expression levels of FBXL5,IREB2,TFRC and FTH1 were detected by immu-nohistochemistry,Werstern blot and RT-qPCR.The contents of ferroptosis-related markers Fe2+,MDA,ROS and GSH were detected by applying the kit,and the levels of these markers were analyzed.The relationship between each factor in different colorectal cancer tissues and tumor regression rate and prognosis of neoadjuvant chemotherapy were ana-lyzed.Results(1)The expression of IREB2,FBXL5,TFRC and FTH1 in colorectal cancer was higher than that in normal intestinal mucosa(P＜0.05),and the expression of FBXL5 and FTH1 in colorectal cancer drug-resistant group was lower than that in the sensitive group,whereas the expression of IREB2 and TFRC was higher than that in the sen-sitive group(P＜0.05);(2)The correlation analysis showed a positive correlation between the expression of IREB2 and TFRC in the drug-resistant group,and a negative correlation with the expression of FBXL5 and FTH1 in the drug-resistant group.TFRC expression in the colorectal cancer resistance group were positively correlated(P＜0.05)and negatively correlated with the expression of FBXL5 and FTH1(P＜0.05);(3)the content of Fe2+and GSH was high-er than that of the sensitivity group in the colorectal cancer resistance group,and the level of ROS was lower than that of the sensitivity group(P＜0.05);(4)Fe2+was positively correlated with the expression of IREB2,TFRC,and neg-atively correlated with the expression of FBXL5 and FTH1,and was negatively correlated with the expression of FBXL5 and FTH1.FTH1 expression were both negatively correlated(P＜0.05);(5)tumor regression rate was positively cor-related with the expression of FBXL5 and FTH1,and negatively correlated with the expression of IREB2 and TFRC,as well as positively correlated with the level of ROS,and negatively correlated with Fe2+and GSH(P＜0.05);(6)The expression of IREB2 and TFRC was positively correlated with tumor diameter and lymph node metastasis,and the ex-pression of FBXL5 and FTH1 was negatively correlated with tumor diameter and lymph node metastasis,and the expres-sion of FBXL5 was also negatively correlated with the depth of tumor infiltration(P＜0.05);(7)Kaplan-Meier analy-sis showed that lymph node metastasis,FBXL5,IREB2,TFRC,FTH1,and TRG grading were closely related to the prognosis of colorectal cancer patients(P＜0.05).Cox multivariate regression analysis indicated that lymph node me-tastasis,high expression of IREB2 and TFRC,low expression of FBXL5 and FTH1,and low tumor regression grade(TRG)were risk factors for the ineffectiveness of neoadjuvant chemotherapy in colorectal cancer patients.Conclusion FBXL5 and IREB2 are not only associated with high iron homeostasis,but also closely related to the efficacy and prognosis of neoadjuvant chemotherapy for colorectal cancer.In the future,they may become new targets for the treat-ment of colorectal cancer and improve the prognosis of patients.

Objectives:To investigate the impact of the Micra AV leadless pacemaker on cardiac function.Methods:A total of 76 patients who received the implantation of Micra AV leadless pacemaker due to sick sinus syndrome or atrioventricular block at Ruijin Hospital,Shanghai Jiao Tong University School of Medicine from September 2022 to April 2023 were included in this study.Among them,26 patients(34.2%)had sick sinus syndrome,and 50 patients(65.8%)had atrioventricular block.The patients were followed up for 1 year postoperatively.Cardiac function was evaluated by echocardiography,and the parameters of the pacemaker were collected through the outpatient clinic programming system.Results:After a follow-up of 120(87,181)days,compared with the preoperative state,the left ventricular ejection fraction(LVEF)decreased postoperatively([66.6±5.6]%vs.[63.8±5.2]%,P<0.001),and the cardiac output increased[(4.3±1.2)L/min vs.(5.3±1.5)L/min,P<0.001].There were no statistically significant differences in various cardiac function indexes of patients with sick sinus syndrome between the postoperative and preoperative states(all P>0.05).Compared with the preoperative state,in patients with atrioventricular block,the LVEF decreased postoperatively([67.0±5.1]%vs.[63.4±4.4]%,P<0.001),the cardiac output increased([4.2±1.1]L/min vs.[5.2±1.2]L/min,P<0.001),and the left ventricular end-diastolic diameter decreased[(49.9±5.4)mm vs.(48.6±5.0)mm,P=0.044].Firth's logistic regression analysis indicated that the preoperative LVEF(for every 1%increase,OR=1.56,95%CI:1.12-2.17,P=0.001),stroke volume(for every 1 ml increase,OR=1.15,95%CI:1.04-1.28,P=0.001),body mass index(for every 1 kg/m2 increase,OR=1.49,95%CI:1.02-2.17,P=0.020),and hypertension(OR=12.71,95%CI:1.11-145.13,P=0.039)were independent risk factors for the decrease in LVEF after surgery in patients with atrioventricular block.After the implantation of the MciraTM AV leadless pacemaker,the overall atrioventricular synchrony rate was 81.2%(68.8%,89.0%).The atrioventricular synchrony rates of patients with sick sinus syndrome and those with atrioventricular block were 70.6%(59.5%,83.4%)and 82.4%(74.2%,89.3%)respectively(P<0.05).Firth's logistic regression analysis indicated that sick sinus syndrome(OR=0.26,95%CI:0.07-0.89,P=0.029)and preoperative LVEF(for every 1%increase,OR=1.18,95%CI:1.03-1.35,P=0.015)were independent predictive factors for the atrioventricular synchrony rate>80%.Conclusions:There are differences in the impacts of the Micra AV leadless pacemaker on the LVEF and atrioventricular synchrony rate between patients with sick sinus syndrome and those with atrioventricular block.The preoperative LVEF,stroke volume,body mass index,and hypertension have independent predictive effects on the decrease in postoperative LVEF in patients with atrioventricular block.Sick sinus syndrome and preoperative LVEF are independent predictive factors for the atrioventricular synchrony rate>80%after surgery.

BACKGROUND:Degeneration of nucleus pulposus cells is a key component of intervertebral disc degeneration.Ferroptosis,a novel form of programmed cell death,is closely associated with the onset and progression of intervertebral disc degeneration;however,its precise mechanisms remain unclear.OBJECTIVE:To establish an oxidative stress model in vitro by inducing ferroptosis in nucleus pulposus cells using tert-butyl hydroperoxide and to investigate the mechanisms of tert-butyl hydroperoxide-induced ferroptosis in nucleus pulposus cells,thereby elucidating the role of ferroptosis in the pathogenesis of intervertebral disc degeneration.METHODS:Nucleus pulposus cells were treated with varying concentrations of tert-butyl hydroperoxide(0,25,50,100,and 200 μmol/L),and cell morphology and viability were assessed using fluorescence microscopy and the cell counting kit-8 assay.Interventions with 100 μmol/L tert-butyl hydroperoxide,10 μmol/L RSL3,or dimethylsulfoxide were applied to nucleus pulposus cells,and cell proliferation was evaluated using the EdU assay.The expression levels of ferroptosis-related proteins(glutathione peroxidase 4,ferritin heavy chain 1,PTGS2,and ACSL4)and intervertebral disc degeneration marker proteins(matrix metalloproteinase 13 and Col2A)were analyzed via western blot and immunofluorescence.Additionally,reactive oxygen species and lipid peroxidation levels were quantified using the reactive oxygen species detection kit and C11-BODIPY probe.Mitochondrial morphological changes were observed under transmission electron microscopy.RESULTS AND CONCLUSION:(1)tert-Butyl hydroperoxide treatment significantly reduced the viability and proliferation of nucleus pulposus cells.(2)tert-Butyl hydroperoxide induced typical ferroptosis-related morphological changes in nucleus pulposus cells.(3)tert-Butyl hydroperoxide exposure led to a decrease in the expression of ferroptosis-suppressing proteins glutathione peroxidase 4 and ferritin heavy chain 1,while increasing the expression of ferroptosis-promoting factors ACSL4 and PTGS2.(4)tert-Butyl hydroperoxide elevated intracellular reactive oxygen species production and lipid peroxidation levels in nucleus pulposus cells.(5)Transmission electron microscopy revealed ferroptosis-specific mitochondrial changes in nucleus pulposus cells treated with tert-butyl hydroperoxide,including contraction,reduced cristae,and increased membrane density.(6)tert-Butyl hydroperoxide treatment also resulted in the increased expression of matrix metalloproteinase 13 and decreased expression of Col2A in nucleus pulposus cells.In conclusion,tert-butyl hydroperoxide induces ferroptosis in nucleus pulposus cells,contributing to the development of intervertebral disc degeneration.This process may represent a key pathological mechanism in intervertebral disc degeneration and offers potential targets for developing novel therapeutic strategies.

Objective To study whether electroacupuncture(EA)attenuates traumatic brain injury(TBI)by down-regulating glutamate carboxypeptidase Ⅱ(GCPII)gene expression in rats.Methods Rats were divided into Sham group(n=10),TBI group(n=11),TBI+EA group(n=11),TBI+EA+GCPII-NC group(n=11)and TBI+EA+GCPII-OE group(n=11).Sham group rats underwent sham surgery,while other groups rats underwent TBI modeling using an electronic brain injury instrument.The rats in Sham group and TBI group were fed normally,and the rats in other groups were treated with electroacupuncture for 14 days.On the basis of electroacupuncture treatment,rats in TBI+EA+GCPII-NC group and TBI+EA+GCPII-OE group were injected with GCPII-NC and GCPII-OE,respectively.After treatment,the cognitive function of rats was evaluated by neurological function score and Morris water labyrinth task.HE and TUNEL staining were performed on brain tissue.The water content,glutamate(Glu)content,calcium(Ca2+)concentration,superoxide dismutase(SOD),catalase(CAT),glutathione peroxidase(GSH-Px)and malondialdehyde(MDA)in brain tissue of rats in each group were measured.The mRNA or protein expression of GCPII,Bax,Bcl2 and cleaved caspase-3 in brain tissue were detected by qRT-PCR or Western blot.Results Compared with Sham group,the expression of mRNA and protein of GCPII in TBI group increased,the neurological function score and escape latency increased,the number of crossing the platform decreased,the water content increased,the cortex showed obvious damage,the content of Glu increased,the concentration of calcium increased,the levels of SOD,CAT and GSH-Px decreased,the level of MDA increased,the positive rate of TUNEL increased,the expression of Bax and cleaved caspase-3 protein increased,and the expression of Bcl2 protein decreased significantly(P<0.05).Compared with TBI group,the expression level of mRNA and protein of GCPII in TBI+EA group decreased,the neurological function score and escape latency decreased,the number of crossing platform increased,the water content decreased,the morphology of cortex improved obviously,the content of Glu decreased,the concentration of calcium decreased,the level of SOD,CAT and GSH-Px increased,the level of MDA decreased,the positive rate of TUNEL decreased,the expression level of Bax and cleaved caspase-3 protein decreased,and the expression level of Bcl2 protein increased significantly(P<0.05).Compared with TBI+EA group and TBI+EA+GCPII-NC group,the expression level of mRNA and protein of GCPII in TBI+EA+GCPII-OE group increased,neurological function score and escape latency increased,the number of crossing platform decreased,water content increased,cortical injury aggravated,Glu content increased,calcium concentration increased,SOD,CAT and GSH-Px levels decreased,MDA level increased,TUNEL positive rate increased,Bax and cleaved caspase-3 protein expression increased,and the expression of Bcl2 protein decreased significantly(P<0.05).Conclusion By down-regulating the expression of GCPII gene,electroacupuncture reduced the content of glutamate in the brain tissue of TBI rats,thereby inhibiting calcium overload,oxidative stress and neuronal apoptosis in the brain tissue,and thereby improving cognitive function and alleviating brain injury.

Objective:To explore the clinical effects of tibial periosteal distraction combined with antibiotic bone cement in treating diabetic foot ulcer.Methods:The study was a retrospective observational study. From March 2021 to March 2024, 52 patients with diabetic foot ulcers who met the inclusion criteria were admitted to Gansu Provincial People's Hospital, including 25 males and 27 females, aged 34-77 years. According to the treatment methods used by the patients, they were divided into control group (22 cases) treated with antibiotic bone cement alone and combined group (30 cases) treated with tibial periosteal distraction combined with antibiotic bone cement. Toe amputation rate, limb amputation rate, length of hospitalization, and ulcer healing time-consuming of patients were recorded. Before the first treatment and 3 weeks after the last treatment, the ankle skin temperature and ankle-brachial index of the affected foot were measured routinely, the pain of the affected foot was evaluated by using visual analog scale (VAS), and the peripheral nerve function of the affected foot was evaluated by 10 g nylon thread examination (denoted as 10 g nylon thread test value). Three weeks after the last treatment, the clinical efficacy of patients was evaluated and the overall rate of clinical efficacy was calculated.Results:There were no statistically significant differences in the comparison of toe amputation rate and limb amputation rate of patients in the 2 groups ( P>0.05). The length of hospitalization and ulcer healing time-consuming of patients in combined group were (23±5) and (41±6) d, respectively, which were significantly shorter than (27±5) and (46±6) d in control group (with t values of 3.08 and 3.18, respectively, both P values <0.05). The ankle skin temperature of the affected foot of patients in combined group was (34.1±1.5) ℃, and the ankle-brachial index was 0.72±0.08 three weeks after the last treatment, which were significantly higher than (32.1±1.6) ℃ and 0.58±0.09 before the first treatment within the group (with t values of 5.10 and 6.37, respectively, P<0.05) and (31.8±1.1) ℃ and 0.59±0.09 three weeks after the last treatment in control group (with t values of 6.88 and 5.49, respectively, P<0.05). The pain VAS score of the affected foot of patients in combined group 3 weeks after the last treatment was significantly lower than that before the first treatment within the group and 3 weeks after the last treatment in control group (with t values of 8.16 and 6.83, respectively, both P values <0.05), and the 10 g nylon thread test value was significantly higher than that before the first treatment within the group and 3 weeks after the last treatment in control group (with t values of 6.15 and 4.23, respectively, both P values <0.05). Three weeks after the last treatment, the overall rate of clinical efficacy of patients in combined group was 96.7% (29/30), which was significantly higher than 63.6% (14/22) in control group, χ2=7.51, P<0.05. Conclusions:Tibial periosteal distraction combined with antibiotic bone cement has good clinical effects in the treatment of diabetic foot ulcers. It can shorten the length of patients' hospitalization, promote the healing of the ulcers, reduce the pain in the affected foot, and improve the blood supply and peripheral nerve function in the affected foot.

Purpose The current study aims to elucidate the interrelationships among IREB2,FBXL5,iron ho-meostasis,and the therapeutic efficacy of neoadjuvant chemotherapy.Methods A total of 97 samples,classified into colorectal cancer neoadjuvant chemotherapy-resistant and-sensitive groups,along with their corresponding paracancer-ous normal mucosa were collected.The expression levels of FBXL5,IREB2,TFRC and FTH1 were detected by immu-nohistochemistry,Werstern blot and RT-qPCR.The contents of ferroptosis-related markers Fe2+,MDA,ROS and GSH were detected by applying the kit,and the levels of these markers were analyzed.The relationship between each factor in different colorectal cancer tissues and tumor regression rate and prognosis of neoadjuvant chemotherapy were ana-lyzed.Results(1)The expression of IREB2,FBXL5,TFRC and FTH1 in colorectal cancer was higher than that in normal intestinal mucosa(P＜0.05),and the expression of FBXL5 and FTH1 in colorectal cancer drug-resistant group was lower than that in the sensitive group,whereas the expression of IREB2 and TFRC was higher than that in the sen-sitive group(P＜0.05);(2)The correlation analysis showed a positive correlation between the expression of IREB2 and TFRC in the drug-resistant group,and a negative correlation with the expression of FBXL5 and FTH1 in the drug-resistant group.TFRC expression in the colorectal cancer resistance group were positively correlated(P＜0.05)and negatively correlated with the expression of FBXL5 and FTH1(P＜0.05);(3)the content of Fe2+and GSH was high-er than that of the sensitivity group in the colorectal cancer resistance group,and the level of ROS was lower than that of the sensitivity group(P＜0.05);(4)Fe2+was positively correlated with the expression of IREB2,TFRC,and neg-atively correlated with the expression of FBXL5 and FTH1,and was negatively correlated with the expression of FBXL5 and FTH1.FTH1 expression were both negatively correlated(P＜0.05);(5)tumor regression rate was positively cor-related with the expression of FBXL5 and FTH1,and negatively correlated with the expression of IREB2 and TFRC,as well as positively correlated with the level of ROS,and negatively correlated with Fe2+and GSH(P＜0.05);(6)The expression of IREB2 and TFRC was positively correlated with tumor diameter and lymph node metastasis,and the ex-pression of FBXL5 and FTH1 was negatively correlated with tumor diameter and lymph node metastasis,and the expres-sion of FBXL5 was also negatively correlated with the depth of tumor infiltration(P＜0.05);(7)Kaplan-Meier analy-sis showed that lymph node metastasis,FBXL5,IREB2,TFRC,FTH1,and TRG grading were closely related to the prognosis of colorectal cancer patients(P＜0.05).Cox multivariate regression analysis indicated that lymph node me-tastasis,high expression of IREB2 and TFRC,low expression of FBXL5 and FTH1,and low tumor regression grade(TRG)were risk factors for the ineffectiveness of neoadjuvant chemotherapy in colorectal cancer patients.Conclusion FBXL5 and IREB2 are not only associated with high iron homeostasis,but also closely related to the efficacy and prognosis of neoadjuvant chemotherapy for colorectal cancer.In the future,they may become new targets for the treat-ment of colorectal cancer and improve the prognosis of patients.