Lycium barbarum polysaccharides protects retinal ganglion cells against oxidative stress injury

The accumulation of excessive reactive oxygen species can exacerbate any injury of retinal tissue because free radicals can trigger lipid peroxidation,protein damage and DNA fragmentation.Increased oxidative stress is associated with the common pathological process of many eye diseases,such as glaucoma,diabetic retinopathy and ischemic optic neuropathy.Many studies have demonstrated that Lycium barbarum polysaccharides(LBP)protects against oxidative injury in numerous cells and tissues.For the model of hypoxia we used cultured retinal ganglion cells and induced hypoxia by incubating with 200μM cobalt chloride(CoCl2)for 24 hours.To investigate the protective effect of LBP and its mechanism of action against oxidative stress injury,the retinal tissue was pretreated with 0.5 mg/mL LBP for 24 hours.The results of flow cytometric analysis showed LBP could effectively reduce the CoCl2-induced retinal ganglion cell apoptosis,inhibited the generation of reactive oxygen species and the reduction of mitochondrial membrane potential.These findings suggested that LBP could protect retinal ganglion cells from CoCl2-induced apoptosis by reducing mitochondrial membrane potential and reactive oxygen species.

Incidence investigation and analysis of hepatic stress injury after trauma

Objective To investigate the etiology and pathogenesis of hepatic stress injury after trauma.Methods 4 677 patients with severe trauma in 153th Hospital of PLA from Jan.2004 to Jul.2005 were enrolled in this study to investigate the incidence of hepatic stress injury,and furthermore,in combination with medical information,the possible pathogenesis was analyzed.Results The main manifestation of hepatic stress injury was the elevated ALT or AST levels(387 cases,8.3%).The incidence of hepatic stress injury after hand injury,burn injury,head injury,bone injury,abdominal injury,and thoracic injury were 16.6%,6.9%,5.6%,5.0%,3.8% and 2.0%,respectively,and among which,the incidence of hepatic stress injury after hand injury was statistically highest(P<0.01).Conclusion The total incidence of hepatic stress injury after trauma was 8.3%.Intestinal endotoxemia might be one of the beginning components of hepatic stress injury after trauma.

Biomechanics associated with tibial stress fracture in runners:A systematic review and meta-analysis

Background:Tibial stress fracture(TSF)is an overuse running injury with a long recovery period.While many running studies refer to biomechanical risk factors for TSF,only a few have compared biomechanics in runners with TSF to controls.The aim of this systematic review and meta-analysis was to evaluate biomechanics in runners with TSF compared to controls.Methods:Electronic databases PubMed,Web of Science,SPORTDiscus,Scopus,Cochrane,and CINAHL were searched.Risk of bias was assessed and meta-analysis conducted for variables reported in 3 or more studies.Results:The search retrieved 359 unique records,but only the 14 that compared runners with TSF to controls were included in the review.Most studies were retrospective,2 were prospective,and most had a small sample size(5-30 per group).Many variables were not significantly different between groups.Meta-analysis of peak impact,active,and braking ground reaction forces found no significant differences between groups.Individual studies found larger tibial peak anterior tensile stress,peak posterior compressive stress,peak axial acceleration,peak rearfoot eversion,and hip adduction in the TSF group.Conclusion:Meta-analysis indicated that discrete ground reaction force variables were not statistically significantly different in runners with TSF compared to controls.In individual included studies,many biomechanical variables were not statistically significantly different between groups.However,many were reported by only a single study,and sample sizes were small.We encourage additional studies with larger sample sizes of runners with TSF and controls and adequate statistical power to confirm or refute these findings.

Impact loading in female runners with single and multiple bone stress injuries during fresh and exerted conditions

Background:Bone stress injuries(BSIs)are common in female runners,and recurrent BSI rates are high.Previous work suggests an association between higher impact loading during running and tibial BSI.However,it is unknown whether impact loading and fatigue-related loading changes discriminate women with a history of multiple BSIs.This study compared impact variables at the beginning of a treadmill run to exertion andthe changes in those variables with exertion among female runners with no history of BSI as well as among those with a history of single or multiple BSIs.Methods:We enrolled 45 female runners(aged 18-40 years)for this cross-sectional study:having no history of diagnosed lower extremity BSI(N-BSI,n=14);a history of 1 lower extremity BSI(1-BSI,n=16);and diagnosed by imaging,or a history of multiple(>3)lower extremity BSIs(M-BSI,n=15).Participants completed a 5-km race speed run on an instrumented treadmill while wearing an Inertial Measurement Unit.The vertical average loading rate(VALR),vertical instantaneous loading rate(VILR),vertical stiffness during impact via instrumented treadmill,and tibial shock determined as the peak po sitive tibial acceleration via Inertial Measurement Unit were measured at the beginning and the end of the run.Results:There were no differences between groups in VALR,VILR,vertical stiffness,or tibial shock in a fresh or exerted condition.However,compared to N-BSI,women with M-BSI had greater increase with exertion in VALR(-1.8%vs.6.1%,p=0.01)and VILR(1.5%vs.4.8%,p=0.03).Similarly,compared to N-BSI,vertical stiffness increased more with exertion among women with M-BSI(-0.9%vs.7.3%,p=0.006)and 1-BSI(-0.9%vs.1.8%,p=0.05).Finally,compared to N-BSI,the increase in tibial shock from fresh to exerted condition was greater among women with M-BSI(0.9%vs.5.5%,p=0.03)and 1-BSI(0.9%vs.11.2%,p=0.02).Conclusion:Women with 1-BSI or M-BSIs experience greater exertion-related increases in impact loading than women with N-BSI.These observations imply that exertion-related changes in gait biomechanics may contribute to risk of BSI.

BH3-only protein Bim is involved in myocardial injury induced by co-stress of ischemia and cold stress in rats

Objectives To investigate the effect of co-exposure of myocardial ischemia and cold stress on myocardial injury in rats and the relative mechanism.Methods Myocardial ischemia model was established by ligation of left coronary artery.SD rats were randomly allocated to 4 groups; sham+normal temperature(S group),sham+cold stress(SC group),myocardial ischemia+ normal temperature(Ⅰgroup), myocardial ischemia+cold stress(IC group).On the condition of 26℃,SC and IC groups were keeped in a 4℃artificial chamber for 8h(8;00-16:00) for 4 consecu- tive days.Car diac function was assessed by echocardiography;pathological change was analyzed by HE staining;myocardial infarct size was determined by TTC staining;Bim,Caspase-3 expression in myocardium was determined by western blotting.Results It was demonstrated that co-exposure of myocardial ischemia and cold stress could significantly make the cardiac muscle in abnormal shape,increase the infarct size and the expression of Bim and Caspase-3.Conclusions Co-exposure of myocardial ischemia and cold stress may aggravate the cardiac injury,pro- apoptosis protein Bim is involved.

Protective effect of extracorporeal membrane pulmonary oxygenation combined with cardiopulmonary resuscitation on post-resuscitation lung injury

BACKGROUND: Cardiac arrest(CA) is a critical condition that is a concern to healthcare workers. Comparative studies on extracorporeal cardiopulmonary resuscitation(ECPR) and conventional cardiopulmonary resuscitation(CCPR) technologies have shown that ECPR is superior to CCPR. However, there is a lack of studies that compare the protective effects of these two resuscitative methods on organs. Therefore, we aim to perform experiments in swine models of ventricular fibrillation-induced CA to study whether the early application of ECPR has advantages over CCPR in the lung injury and to explore the protective mechanism of ECPR on the post-resuscitation pulmonary injury.METHODS: Sixteen male swine were randomized to CCPR(CCPR;n=8;CCPR alone) and ECPR(ECPR;n=8;extracorporeal membrane oxygenation with CCPR) groups, with the restoration of spontaneous circulation at 6 hours as an endpoint. RESULTS: For the two groups, the survival rates between the two groups were not statistically significant(P>0.05), the blood and lung biomarkers were statistically significant(P<0.05), and the extravascular lung water and pulmonary vascular permeability index were statistically significant(P<0.01). Compared with the ECPR group, electron microscopy revealed mostly vacuolated intracellular alveolar type II lamellar bodies and a fuzzy lamellar structure with widening and blurring of the blood-gas barrier in the CCPR group.CONCLUSIONS: ECPR may have pulmonary protective effects, possibly related to the regulation of alveolar surface-active proteins and mitigated oxidative stress response postresuscitation.

Safety and feasibility of irreversible electroporation for the pancreatic head in a porcine model

BACKGROUND Irreversible electroporation(IRE)is a local non-thermal ablative technique which has been suggested as a potential cancer therapy.However,the specific anatomic characteristics of the pancreatic head make it challenging to perform any local ablation in this region.Therefore,the safety and feasibility of IRE in the pancreatic head region should be further explored.AIM To evaluate the safety of IRE in pancreatic head region including its effects on pancreatic ducts,vessels,and adjacent gastrointestinal organs.METHODS Eight landrace miniature pigs underwent IRE of pancreatic head tissue successfully,with a total of 16 lesions created.Laboratory testing including white blood cell(WBC)count and serum amylase before IRE with follow-up laboratory analysis and pathological examination at 1,7,14,and 28 d postablation were performed.RESULTS All pigs tolerated the ablation procedure without serious perioperative complications.Transiently elevated WBC count and amylase were observed at 24 h post-IRE,suggesting an acute pancreatic tissue damage which was confirmed by pathological observations.Vascular endothelial cells and pancreatic duct epithelial cells in ablation zone were also positive in terminal deoxynucleotidyl transferase dUTP nick end labeling staining.There was extensive duodenum mucosa damage with local hemorrhage 24 h after ablation,while regeneration of new villous structures were observed at 7 and 28 d post-IRE.Masson’s trichromatic staining showed that the extracellular matrix was still intact in vessels and pancreatic ducts,and even in the duodenum.CONCLUSION IRE ablation to the pancreatic head may be safe and feasible without long-term damage to the surrounding vital structures.However,risks of stress injuries in acute phase should be taken into consideration to prevent severe perioperative complications.

The relationship between Metrnl and diabetic cardiomyopathy and its related molecular mechanism

Objective:To investigate the changes of serum concentration of Metrnl in diabetic cardiomyopathy mice,and the relationship between Metrnl and Diabetic cardiomyopathy(DCM)and its molecular mechanism.Methods:Fifteen male mice were randomly divided into experimental group(DCM+Metrnl),model group(DCM)and control group.Metrnl concentration was measured with an enzyme-linked immunosorbent assay.The experimental group was treated with Metrnl,and the control group and model group were treated with equal volume solvent.Then the myocardial pathological changes,reactive oxygen species and the expression of PPARs and GLUT4 protein and the expression of CD36 and SOD gene were observed after 7 days of administration of recombinant Metrnl.Results:Serum Metrnl concentrations were elevated in DCM(P>0.05).Metrnl reduced the serum concentrations of total cholesterol(TG,P<0.05),triglyceride(TC,P<0.05)and low density lipoprotein cholesterol(LDL-C,P<0.05),while increased high density lipoprotein cholesterol(HDL-C,P<0.05)in DCM.In addition,Metrnl improved the energy metabolism of DCM,decreased the production of reactive oxygen species(ROS)and up-regulated the protein expressions of PPAR-a,PPAR-β/δ,GLUT4 and the expression of SOD in cardiomyocytes,while CD36 gene expression was down-regulated.Conclusion:Serum Metrnl concentrations were elevated in DCM mouse modles.Metrnl improved lipid metabolism and cardiac function in DCM.Besides,it can reduced myocardial oxidative stress injury through PPAR-β/δ,GLUT4 pathway.

7,8-dihydroxyflavone protects human renal proximal tubular cells from hypoxia injury via inhibiting endoplasmic reticulum stress

Objective To observe the effects of 7,8-dihydroxyflavone(7,8-DHF)on hypoxia induced endoplasmic reticulum stress(ERS)in human proximal tubular epithelial cells(HK-2).Methods The mRNA level of ERS associated biomarkers was evaluated by RT-PCR assay