rough the ultramicroscopic observation on muscle and microcirculation, Group A,where a largeamount of DXM combined with heporin was given svstematically and locally into the femoral artery of the severed limb before replantation, and in Group B only heporin was given, and Group C and D ascontrol.The results showed that if the hormone and heparin were administred in large dosage, it wasadvantageous to reduce the tissues from reperfusion injury during delayed replantation.
OBJECTIVE To determine the role of endogenous carbon monoxide(CO) in oxidant-mediated organ injury following limb ischemia-reperfusion (I/R) in rats. METHODS: Sixty-four SD rats were divided into 4 groups: Sham group, Sham + zinc protoporphyrin (ZnPP, an inhibitor of heme oxygenase activity), 2-hour ischemia followed by 4-hour reperfusion (I/R) group and I/R + ZnPP group. Carboxyhemoglobin (COHb) level in the artery blood, malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in the lung, heart, liver and kidney were detected. The 24-hour survival rate of rats was studied. RESULTS: Compared with the sham group, the COHb level and MDA content significantly increased, while the SOD activity and the survival rate significantly decreased in I/R group (P lt; 0.05). Compared with the I/R group, MDA content significantly increased, while the SOD activity, the 24-hour survival rate and COHb level significantly decreased in I/R + ZnPP group (P lt; 0.05, respectively). CONCLUSION: Limb I/R could lead to the oxidant-mediated multiple organ injury accompanied by the increase of CO level which play an important role in the defense against I/R-induced remote multiple organ injury in rats.
Objective To discuss the relationship between the changes of hepatic blood flow detected by usingspectral Doppler ultrasound and serum TNF- α and IL-1 β levels after liver ischemia/reperfusion （I/R） of rat. Methods The hepatic ischemia 15 min and reperfusion models were established by using pringle method. The hepatic blood flow of hepatic artery and portal vein at 1， 6， and 24 hours after liver I/R were detected by using spectral Doppler ultrasound， the total blood flow volume （FV） was calculated， and the serum TNF- α and IL-1 β levels at each time point were detected. The correlation between the TNF-α， IL-1 β， and FV were analyzed. Results The FV at 1 hour and 6 hours after reperfusion in I/R group were less than those in sham operation （SO） group 〔（52.08±11.88） mL/min vs. （85.32±29.85） mL/min and （44.69±8.75）mL/min vs. （81.41±28.67） mL/min， P＜0.05〕. The FV at 24 hours after operation or reperfusion of 2 groups was no significant differences （P＞0.05）. The serum content of TNF-α at 1 hour after reperfusion in I/R group was higher than that in SO group 〔（310.52±39.83）pg/mL vs. （240.74±31.65）pg/mL， P＜0.05〕. The serum contents of TNF-α at 6 and 24 hours after operation or reperfusion of 2 groups were no significant differences （P＞0.05）. The serum contents of IL-1β at 1 hour and 6 hours in I/R group were higher than those in SO group 〔（38.08±3.73） pg/mLvs. （22.03±0.79） pg/mL and （27.44±6.11） pg/mL vs. （21.78±0.71） pg/mL， P＜0.05〕. The serum content of IL-1β at 24 hours after operation or reperfusion of 2 groups was no significant differences （P＞0.05）. There was a negative correlation between the FV and TNF-α or IL-1β （r=-0.43， P＜0.05；r=-0.46， P＜0.05）. Conclusions Spectral Doppler ultrasound can observe the changes of hepatic blood flow and evaluate the hepatic microcirculation indirectly. The hepatic blood flow after liver I/R decreases and it may be related to over expression of TNF-α and IL-1β.
Objective To investigate the effects of different reperfusion sequence on hepatic warm ischemia-reperfusion injury and its related mechanisms. Methods Ninety-six healthy male Sprague Dawley rats were randomly divided into 6 groups by using random digits method (n=16, each)： Sham operation group, only shammed operation for negative control; the other 5 groups were all experimental groups, which were divided according to different reperfusion sequences of portal vein and hepatic artery: reperfusion first through the portal vein for 1 min with subsequent full reperfusion group, reperfusion first through the portal vein for 2 min with subsequent full reperfusion group, reperfusion first through the hepatic artery for 1 min with subsequent full reperfusion group, reperfusion first through the hepatic artery for 2 min with subsequent full reperfusion group, simultaneous reperfusion through the portal vein and hepatic artery group. Each group was further randomly divided into two subgroups (n=8, each) for sample collection at 2, 4 hours after reperfusion respectively. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and malondialdehyde (MDA), superoxide dismutase (SOD) and glutathion (GSH) in hepatic tissue were detected respectively. HE staining of histopathologic slides was used to observe the morphological changes of hepatic tissue. TUNEL method was used to assess the apoptosis index (AI) of hepatocytes. Results The liver of rat was approximately normal in the sham operation group with lower levels of ALT, AST, MDA and AI, and higher levels of SOD and GSH as compared with all the experimental groups (P＜0.01). Less hepatic ischemia-reperfusion injury was found in reperfusion first through the portal vein for 1 min with subsequent full reperfusion group, whose ALT, AST, MDA and AI levels were significantly lower than those of the other experimental groups (P＜0.05 or P＜0.01), and its SOD and GSH levels were higher than those of the other experimental groups (P＜0.05 or P＜0.01). HE staining also showed milder hepatic injury in reperfusion first through the portal vein for 1 min with subsequent full reperfusion group as compared with the other experimental groups. Conclusion Hepatic reperfusion first through portal vein for short time with subsequent full reperfusion could depress the synthesis of free oxygen radicals and suppress apoptosis of hepatocytes, thus relieving hepatic ischemia-reperfusion injury.
Objective To investigate the expression of nuclear factor (NF)-κB and intercellular adhesion molecule (ICAM)-1 in rat′s retina injured by ischemia-reperfusion, and the effect of pyrrolidine dithiocarbamate (PDTC) on the expression of NF-κB and ICAM-1. Method The model of retinal ischemia-reperfusion was set up in 60 SD rats, which were divided into two groups with 30 rats in each: ischemia-reperfusion group and ischemia-reperfussion with injection of PDTC group. The left cephalic artery of each rat was ligated, and the right side was the control. Every group was subdivided into group 1 hour, 6, 12, 24, 48, and 72 hours after ischemia-reperfusion injury, and with 5 rats in each group. mRNA of NF-κB and ICAM-1 mRNA was measured by in situ hybridization (ISH) method in rat′s retina. Every rat underwent electroretinography (ERG) at the corresponding time before executed by neck breaking. Results In ischemia-reperfusion group, expression of NF-κB and ICAM-1 was detected at the 6th hour after ischemia-reperfusion, reached the highest level at the 24th hour, and weakened gradually later. In ischemia-reperfusion with injection of PDTC group, expression of NF-κB and ICAM-1 was detected at the 12th hour after ischemia-reperfusion, and reached the highest level at the 24th hour but lower than that in ischemia-reperfusion group. No expression of NF-κB and ICAM-1 was found in the control group. The relative recovery rate of ERG a and b wave amplitude in ischemia-reperfusion groups was lower than that in ischemia-reperfusion with injection of PDTC group at every stage(P＜0.01 ). The lowest relative recovery rate of ERG a and b wave amplitude in different stages in both of the 2 groups was at the 24th hour(P＜0.01). Conclusions NF-κB and ICAM-1 may play an important role in retinal ischemia-reperfusion injury, as the inhibitor of NF-κB, PDTC may relieve the retinal ischemia-reperfusion injury. (Chin J Ocul Fundus Dis，2004，20：175-178)
Objective To systematically review the effectiveness of amiodarone in treating repurfusion arrhythmia (RA) after thrombolytic therapy for acute myocardial infarction (AMI), so as to provide high quality evidence for formulating the rational thrombolytic therapy for AMI. Methods Randomized controlled trails (RCTs) on amiodarone in treating RA after thrombolytic therapy for AMI were electronically retrieved in PubMed, EMbase, The Cochrane Library (Issue 3, 2012), CBM, CNKI, VIP and WanFang Data from inception to January, 2013. According to the inclusion and exclusion criteria, two reviewers independently screened literature, extracted data, and assessed quality. Then RevMan 5.1 software was used for meta-analysis. Results A total of 5 RCTs involving 440 patients were included. The results of meta-analysis suggested that, compared with the blank control, amiodarone reduced the incidence of RA after thrombolytic therapy in treating AMI (RR=0.60, 95%CI 0.48 to 0.74, Plt;0.000 01) and the incidence of ventricular fibrillation (RR=0.47, 95%CI 0.26 to 0.85, P=0.01). It neither affected the recanalization rate of occluded arteries after thrombolytic therapy (RR=1.00, 95%CI 0.88 to 1.15, P=0.94) nor decreased the mortality after surgery (RR=0.33, 95%CI 0.10 to 1.09, P=0.07). Conclusion Current evidence indicated that, amiodarone can decrease the incidence of RA. Unfortunately, the mortality rate can’t be reduced by amiodarone. Due to the limited quality and quantity of the included studies, more high quality studies are needed to verify the above conclusion
Objective Telomerase reverse transcriptase (TERT) is the key factor to determine cell growth and l ifespan. Meanwhile, it is tightly related to resistance of cell to stress and apoptosis. However, up till now l ittle is known about the role TERT plays in nervous system. To investigate the effect of conditioned medium from astrocytes (AS) transfected with TERT on neurons subjected to hypoxia-ischemia-reperfusion (HI-RP) through construction of in vitro HI-RP model of neurons. Methods An eukaryote expression plasmids containing rat full length TERT gene was constructed as pcDNA3-TERT. Twenty newborn rats at age of 3 days were sacrificed and their cerebral cortex were collected for isolation and cultivationof AS. Then AS were transfected with pcDNA3-TERT through l iposomes mediation, and positive clones were selected by G418 and expanded for continuous culture to establ ish the plamid pcDNA3-TERT transfection group. Meanwhile, the empty plasmid pcDNA3 transfection group and the non-transfection group were establ ished as control. The expression of gl ial fibrillary acidic protein (GFAP), which was the specific marker of the AS, was detected by immunocytochemistry, as well as the expression of TERT. Astrocyte conditioned medium (ACM) of the plamid pcDNA3-TERT transfection group was collected as TERT-ACM, while the ACM of the empty plasmid pcDNA3 transfection group and the non-transfection group were collected respectively as p-ACM and ACM. Next, 60 rats at age of 1 day were sacrificed and their cerebral cortex were collected for isolation and cultivation of neurons. The neurons were randomly divided into experimental group and normal group, the experimental group were further divided into 4 groups including control group, ACM group, p-ACM group, and TERT-ACM group. The neurons of control group were subjected to HI damage in serum-free DMEM, and the neurons of ACM group, p-ACM group, and TERTACM group were subjected to HI damage in different medium which contained ACM, p-ACM, and TERT-ACM, respectively. After duration of HI for 3 hours under the environment with 5%CO2, 1%O2, and 94%N2; the neurons of experimental groups were placed in CO2 incubator to imitate RP for 3, 6, 18, 24, and 36 hours in vitro. The neurons of normal group were not subjected to HI and RP treatment. During the treatment of HI-RP, the survival ratio of neurons was detected by means of MTT, the lactate dehydrogenase (LDH) activity of neuron medium with LDH detection kit, and the neuronal apoptosis by means of TUNEL. Results The percentages of GFAP positive cells were 98%, 99%, and 98% in non-transfection group, plasmid pcDNA3-TERT transfection group, and plasmid pcDNA3 transfection group, respectively. There was no expression of TERT in no-transfection group and plasmid pcDNA3 transfection group, and the percentage of TERT positive cells in plasmid pcDNA3- TERT transfection group was 98%. Compared with normal group, the survival ratio of ......（余见正文）
Objective To elucidate the protective effect of leukocyte depletion on the myocardium during the settings of myocardial reperfusion injury. Methods Twenty patients undergoing cardiopulmonary bypass with continuous infusion of blood cardioplegia were randomized into two groups:the control group (n=10) with no leukocyte depletion filter used, and the experimental group (n=10) with the use of leukocyte depletion filter on the bypass circuit. The blood cells count before and after the filtration were measure...
Exosomes are nanovesicles actively secreted by cells, which selectively encapsulate biologically active molecules such as proteins, RNA, and cytokines. They play an important role in intercellular communication, immune regulation, and maintenance of homeostasis, which can also be used as carriers for targeted drug delivery. Retinal ischemia-reperfusion injury (RIRI) is a retinopathy that seriously threatens human vision. At present, the clinical treatment of these diseases are symptomatic treatments, and some patients have poor efficacy or even blindness. As extracellular vesicles rich in functional proteins and RNAs, exosomes can not only be used as drugs for the treatment of RIRI, but also be used as carriers for drug delivery to play synergistic therapeutic effects. In the future, with the deepening of the research on the molecular structure, contents and biological functions of exosomes, as well as the continuous development of ophthalmic biology and genetic engineering technology, exosomes are expected to exert their great potential as therapeutic drugs and carriers, and become an important means of treating RIRI.
The classical Hippo pathway leads to the phosphorylation of downstream effector molecules Hippo-Yes-associated protein (Yap) and transcriptional coactivator PDZ-binding motif (Taz) serine sites through a kinase response, thereby promoting cell proliferation, controlling cell polarity, changing cytoskeleton, it plays an important regulatory role in various pathophysiological processes such as epithelial-mesenchymal transition and inhibition of cell contact. Studies have shown that Yap/Taz can affect the progression of vitreoretinal diseases, opening up new prospects for the pathogenesis and clinical treatment of diabetic retinopathy, proliferative vitreoretinopathy, and retinal ischemia-reperfusion injury. Exploring the molecular mechanism of Yap/Taz provides a possible therapeutic target for future research in the treatment of retinal fibrosis diseases such as diabetic retinopathy and proliferative vitreoretinopathy. At the same time, regulating the activity of local Yap/Taz in the retina will also become an effective therapeutic target for damage-repair in retinal ischemia-reperfusion injury. However, Yap inhibitors have potential retinal toxicity and are still in the preclinical development stage. Further research on the mechanism of action and clinical safety of Yap inhibitors will provide new methods for the treatment of retinal diseases.