BACKGROUND:The mechanism,manifestation,prevention and treatment of ischemia-reperfusion injury have been reported in the past.However,there are few studies on the ischemia-reperfusion injury of lower limb skeletal muscle caused by total knee arthroplasty.This article focuses on the pathogenesis,clinical impact,prevention and treatment of the ischemia-reperfusion injury of lower limb caused by total knee arthroplasty. OBJECTIVE:To summarize the related literature of lower limb ischemia-reperfusion injury caused by total knee arthroplasty,analyze the mechanism and significance,and give hints for further research on skeletal muscle ischemia-reperfusion injury. METHODS:The relevant articles on PubMed,CNKI,WanFang and VIP databases published from January 1,2000 to April 30,2022 were searched by computer with the Chinese and English search terms of"ischemia-reperfusion injury,total knee arthroplasty,tourniquet,mechanism,pathophysiology,skeletal muscle,treatment".After excluding repetitive research and some basic articles with low correlation,68 articles were finally selected for review. RESULTS AND CONCLUSION:(1)The pathogenesis of ischemia-reperfusion injury is related to oxygen free radicals,intracellular calcium overload,neutrophil activation,as well as high concentration of nitric oxide,no reflow phenomenon,apoptosis and other mechanisms.More detailed mechanism research can provide basis for future prevention and treatment.(2)Ischemia-reperfusion injury of lower limbs will cause local skeletal muscle injury,which may be caused by the trauma of the operation itself or the role of ischemia-reperfusion injury.More targeted research is needed to distinguish the relationship between the two.(3)Ischemia-reperfusion injury of lower limbs may even affect the distal organs,causing kidney and lung damage.It also affects local and systemic circulation.(4)To clarify the effect of ischemia-reperfusion injury can point out the direction for future prevention and treatment.The current prevention and treatment measures mainly include ischemic preconditioning,anesthetic,antioxidant and other drug prevention.(5)The detailed review of ischemia-reperfusion injury of lower limb skeletal muscle caused by total knee arthroplasty can provide basis for future diagnosis and treatment decisions.

BACKGROUND:Dexmedetomidine has the effect of anti-ischemia-reperfusion injury,but the comprehensive and systematic review of its signaling pathway is less. OBJECTIVE:To focus on the review of dexmedetomidine's signaling pathway in the mechanisms of antioxidant stress,inhibition of inflammation,anti-apoptosis,autophagy,and so on. METHODS:The relevant articles on PubMed,CNKI,WanFang,and VIP databases were searched by computer with the key words"ischemia-reperfusion inquiry;dexmedetomidine;signal path;oxidative stress;inflammation;apoptosis"in Chinese and English.After excluding repetitive research and some basic articles with low correlation,57 articles were finally included for review. RESULTS AND CONCLUSION:(1)Dexmedetomidine plays an important role in organ protection through many mechanisms,such as anti-oxidative stress injury,anti-inflammation,anti-apoptosis and autophagy.This involves many pathways,including Nrf2 and its downstream protein antioxidant stress pathway,Toll-like receptor 4 family and nuclear factor-κB-related anti-inflammatory pathway,JAK2/STAT3-related anti-inflammatory pathway,and cholinergic anti-inflammatory pathway,and the cholinergic pathway is the upstream mechanism of many nuclear factor-κB signaling pathways.(2)PI3K/Akt pathway plays different roles according to its activated downstream signals,inhibiting the activation of NLRP3 inflammatory body,activating signal molecules endothelial nitric oxide synthase,mammalian target of rapamycin,and hypoxia-inducible factor 1α to play an anti-inflammatory role,and activate Bad or Bax residues to play an anti-apoptotic role,and PI3K/Akt activates glycogen synthetase kinase-3β.It can also play an anti-inflammatory and anti-apoptotic role.(3)Dexmedetomidine activates SIRT3 to mediate anti-apoptosis and inhibit endoplasmic reticulum stress to produce anti-apoptosis.(4)The detailed review of the anti-ischemia-reperfusion injury signaling pathway of dexmedetomidine can provide a basis for future mechanism research and diagnosis and treatment decisions.

Objective:To investigate the characteristics of early myocardial mechanics changes in diabetic cardiomyopathy (DCM).Method:Sixty healthy 4-week-old male C57BL/6J mice were randomly divided into the T2DM group ( n=30) and the control group ( n=30). The T2DM group was fed with high-fat diet for 4 weeks, and accepted injection of a single high-dose of streptozotocin (STZ) intraperitoneally. Finally, the model was established successfully in 23 mice. The control group was fed with a normal diet and treated with citrate buffer liquid at an equal dose as T2DM group. Then, nine mice were randomly selected from each of the two groups every 4 weeks until the end of the 24th week. Six of the nine mice were randomly selected to perform 7.0 T MR scanning after measuring blood glucose and body weight. Cine images were acquired through cardiovascular MR feature tracking (CMR-FT). The obtained parameters included the left ventricle global peak circumferential strain (LV-GPCS), left ventricle global peak radial strain(GPRS) and the ejection fraction (EF), etc. The rest three mice were sacrificed for observation of the changes of interstitial fibers and micro-vessels in myocardial tissue with Sirius red staining. One-way analysis of variance (ANOVA) and t test were used for comparison. Results:There were significant differences in blood glucose levels between the two groups during the observation period ( P<0.05). In the 4 th-24 th week, the value of GPCS in T2DM group showed a downward trend, and the difference was statistically significant ( F = 8.23, P<0.001). Compared with the control group, the value of GPCS in T2DM group was statistically significant at the 20 th and 24 th week (the 20 th week: -11.4%±2.1% in the T2DM group vs. -14.3%±1.9% in the control group, t=2.54, P=0.029;the 24 th week: -12.3%±1.7% in the T2DM group vs. -14.6%±1.8% in the control group, t=2.35 , P=0.040), while the EF value was different at the 24 th week (51%±5% in the T2DM group vs. 62%±6% in the control group, t=3.38, P=0.007). There was no significant difference in the GPRS of the T2DM mice group over time or compared with the controls ( P>0.05). Moreover, the pathological results showed that the myocardial interstitial fibers in the T2DM group had remarkably increased since the 12 th week. Conclusions:The alterations in myocardial interstitial fibers and myocardial contractility appeared early in T2DM mice. Especially, the left ventricle global peak circumferential strain value is superior to the EF value in reflecting the early changes in DCM.

Objective    To evaluate the impact of different surgical strategies for moderate functional mitral regurgitation (FMR) at the time of aortic valve replacement (AVR) on patients' prognosis. Methods    A total of 118 AVR patients, including 84 males and 34 females, aged 58.1±12.4 years, who were complicated with moderate FMR were retrospectively recruited. Patients were divided into three groups according to the treatment strategy of mitral valve: a group A (no intervention, n=11), a group B (mitral valve repair, n=51) and a group C (mitral valve replacement, n=56). The primary endpoint was the early and mid-term survival of the patients, and the secondary endpoint was the improvement of FMR. Results    The median follow-up time was 29.5 months. Five patients died perioperatively, all of whom were from the group C. Early postoperative FMR improvement rates in the group A and group B were 90.9% and 94.1% (P=0.694). The mid-term mortality in the three groups were 0.0%, 5.9% and 3.9%, respectively (P=0.264), while the incidences of major cardiovascular and cerebrovascular events were 0.0%, 9.8% and 17.7%, respectively (P=0.230). Improvements of FMR in the group A and group B were 100.0% and 94.3% at the mid-term follow-up (P>0.05). Conclusion    For patients receiving AVR with moderate FMR, conservative treatment or concurrent repair of mitral valve may be more reasonable, while mitral valve replacement may increase the incidence of early and mid-term adverse events.

Objective:To observe the effect of enriched rehabilitation on dual-task gait disorder after a transient ischemic attack (TIA) and explore its mechanism.Methods:Sixty TIA patients were randomly divided into a control group and an observation group, each of 30. Another 30 healthy counterparts were selected to form a healthy control group. All of the TIA patients were given routine medication to lower blood pressure and improve brain function, while the observation group was additionally provided with enriched rehabilitation training for 12 weeks. Before and after the intervention, the gait and cognitive functioning of all of the subjects were quantified and their event-related potentials (P300s) and serum brain-derived neurotrophic factor (BDNF) levels were also measured.Results:Before the treatment there were significant differences between the TIA groups and healthy controls in all of the measurements, but there were no significant differences between the control and observation groups. After the treatment, no significant improvement was observed in any of the control group′s results, but there was significant improvement in the observation group′s gait parameters, cognitive functioning, average serum BDNF concentration and in the average latency and amplitude of its P300 signals.Conclusions:Enriched rehabilitation can improve the gait of TIA patients, perhaps through increasing their serum BDNF concentration and improving their cognition.

Objective To investigate the clinical characteristics of granulomatosis with polyangiitis (GPA) patients with scleritis.Methods The completed clinical data of 102 GPA patients from March 2012 to July 2016 in Capital Medical University, Tong Ren Hospital were collected. Altogether 43 GPA patients with scleritis were enrolled, and the clinical data were analyzed respectively. The t test, Mann-Whitney U test and x2testwere used to analyze the data. Results The most common ocular manifestation in GPA was scleritis. The incidence of renal damage(37.2% vs 11.9%,x2=9.148,P=0.002),disease activity(BVAS/GPA score 8.9 vs 5.1,Z=7.847, P=0.000),DEI score (7 vs 4,Z=5.919, P=0.000),inflammation index(56 mm/1 h vs 36 mm/1 h, Z=2.456, P=0.016; CRP 51 mg/L vs 8 mg/L, Z=3.748, P=0.000), neutrophil percent (70% vs 61%, t=3.993, P=0.000),complement 3(1.2 g/L vs 1.0 g/L, t=2.652, P=0.009),plasma fibrinogen(3.5 g/L vs 3.3 g/L, t=3.947, P=0.000), D-dimmer (0.5 mg/L FEU vs 0.3 mg/L FEU, Z=2.371, P=0.018) and ANCA positive rate (90.7% vs 57.6%,x2=13.369,P=0.000)were higher in patients with scleritis,as well as a poor prognosis(2009-FFS 0.4 vs 0.1, Z=2.600, P=0.009). However, a lower rate of subglottic involvement was detected in scleritis group (4.7% vs 20.3%, x2=5.169, P=0.023). There were no significant differences between GPA patients with scleritis and episcleritis in clinical feature, disease activity, inflammatory index and prognosis. Aggressive immunosuppres-sive treatment was appropriate for GPA with scleritis. Tumor necrosis factor (TNF)-аinhibitor was an effective treatment. Conclusion GPA with scleritis usually suffered from higher disease activity index,broader DEI,as well as poorer prognosis. Aggressive treatment should be initiated in order to achieve disease remission. Subglottic involvement is less common in patients with scleritis. The phenotype of scleritis is not associated with disease severity.

Objective:To assess the validity and reliability of the Chinese version of the eleven-item Kutcher Adolescent Depression Scale (KADS-11)in Chinese adolescents,calculate its optimal cut-off value and the sensi-tivity and specificity,and explore the possibility of providing a useful tool to assess the severity of adolescent de-pressive symptoms.Methods:Totally 3180 students aged 11 -17 years were selected from schools in 6 provinces and Shanghai.All of them were asked to complete the KADS-11 and Children Depression Inventory (CDI). Students whose CDI scores were above 19 (including 19)were diagnosed with the DSM-IV criteria of depressive disorder,73 students from Shanghai sample were assessed with KADS-11 and CDI to analyze the test-retest reliabil-ity 1 month later.Results:Exploratory factor analysis showed that KADS-11 had 2 factors,and confirmatory factor analysis tested proved the 2-factor model fit better than the one-factor model.The KADS-11 total scores were posi-tively correlated with CDI total scores (r =0.74,P <0.01 ),and the KADS-11 scores were higher in depressive group than those in non-depressive group.The mean area under the curve (AUC)of KADS-11was 0.94,the mean area under the curve of each item ranged from 0.7 to 0.9.The optimal cut-off point of KADS-11 was total score≥9,sensitivity and specificity were 89% and 90% respectively.The Cronbach's alpha coefficient of the KADS-11 was 0.84,the spilt-half reliability coefficient was 0.71 (P <0.01),and the test-retest coefficient was 0.77 (P <0.01).Conclusion:The KADS-11 is appropriate for Chinese adolescents because of its good validity,reliability and diagnosis accuracy,it could be used to assess depressive symptoms for adolescents.