Objective To evaluate the phenomena of apoptosis and its relevant mechanism during ischemia-reperfusion period. Methods The published papers to explore the apoptotic phenomena and its mechanism in organs or tissues which experienced ischemia-reperfusion injury were reviewed. Results Apoptosis was common in ischemia-reperfusioned organ or tissue. The severity of apoptosis was influenced by many factors such as ischemia, hypoxia, oxygen free radials, intracellular free calcium ion overloading, various cytokines, et al; and also was regulated by bcl-2 family, caspase family and NF-κB，et al. Conclusion Apoptosis is a common phenomenum in ischemiareperfusioned organ or tissue which is affected and regulated by various factors.
Retinal ischemia is the common pathologic process in many ophthalmic diseases, including ischemic optic neuropathy, retinal artery and vein occlusion, carotid artery obstructive disease, retinopathy of prematurity, chronic diabetic retinopathy and glaucoma. It is very important to establish animal models to investigate pathology mechanism and explore the treatment of retinal ischemia disease. At present, the commonly used methods for establishing retinal ischemia animal models include increasing intraocular pressure, ligating of blood vessels, suture method, photochemical method, and drug injection etc. This article summarizes the methods to establish the animal models and analyzes the indication for each animal model. It is expected that the method of establishing a retinal ischemic animal model will be helpful to the experimental design of follow-up retinal ischemia studies.
ObjectiveTo explore the correlation between -765G/C polymorphism of cyclooxygenase-2 (COX-2) gene and the risk of ischemic stroke (IS). MethodsPubMed, CBM, The Cochrane Library (Issue 3, 2015), CNKI, CBM, VIP and WanFang Data were searched from inception to March 2015 to collect case-control or nested case-control studies about -765G/C polymorphism of COX-2 gene and the risk of IS. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then, meta-analysis was performed using RevMan 5.1 software and Stata 12.0 software. ResultsA total of 10 studies involving 2611 cases and 18589 controls were included. The results of meta-analysis showed that, there was no correlation between -765G/C polymorphism and the risk of IS (GC+CC vs. GG: OR=1.05, 95%CI 0.88 to 1.25, P=0.620; CC vs. GG+GC: OR=1.04, 95%CI 0.83 to 1.30, P=0.730; GC vs. GG: OR=1.04, 95%CI 0.87 to 1.25, P=0.630; CC vs. GG: OR=1.09, 95%CI 0.86 to 1.36, P=0.480; C vs. G: OR=1.03, 95%CI 0.89 to 1.20, P=0.700). Subgroup analysis results showed that, the COX-2 gene -765G/C polymorphism was a risk factor for IS in African-Americans (GC+CC vs. GG: OR=1.42, 95%CI 1.12 to 1.78, P=0.003; GC vs. GG: OR=1.39, 95%CI 1.09 to 1.78, P=0.008; CC vs. GG: OR=1.51, 95%CI 1.04 to 2.18, P=0.030; C vs. G: OR=1.27, 95%CI 1.08 to 1.51, P=0.004), but not in Asians and Caucasians. ConclusionCurrent evidence shows that -765G/C polymorphism of COX-2 gene may be a genetic risk factor for IS in African-Americans, but not in Asians and Caucasians. Due to the limited quantity and quality of the included studies, more high quality studies are needed to verify the above conclusion.
Objective To investigate the effect of S-adenosylmethionine (SAM) on mitochondrial injury that was induced by ischemia-reperfusion in rat liver. Methods Fifty-four rats were randomly divided equally into 3 groups: control group, ischemia-reperfusion group (I/R group), and SAM-treated group (SAM group). Hepatic ischemia had been only lasted for 30 min by obstructing the blood stream of hepatic portal vena (the portal vena was only separated but not obstructed in control group). The rats of SAM group received SAM intraperitoneally 2 h prior to ischemia. Blood samples of each group were collected from the inferior cava vena at 0, 1 and 6 h after reperfusion and the serum levels of AST and ALT were detected. Mitochondrial super oxidedismutase (SOD), malondialdehyde (MDA), adenosine triphosphate (ATP) and energy charge (EC) in samples of liver tissue were detected, and the mitochondrial ultrastructure was observed with electronmicroscope. Results The serum levels of AST, ALT and mitochondrial MDA at 0, 1 and 6 h after reperfusion in the I/R group were significantly higher than those in the control group, whereas the levels of mitochondrial SOD, ATP and EC were significantly lower than those in the control group (P＜0.01). Except the value of 0 h, when it comes to SAM group, the levels of AST, ALT and mitochondrial MDA were significantly lower (P＜0.05) and the levels of mitochondrial SOD, ATP and EC were significantly higher (P＜0.05, P＜0.01) than those in the I/R group, respectively. The mitochondrial ultrastructure was injured obviously in I/R group when compared with that in control group. The number of mitochondria decreased and the mitochondria swelled, making the crista became obscure and the density of matrix became lower. The above changes in SAM group were less obvious when compared with those in I/R group. Conclusion SAM may protect mitochondrion against hepatic ischemia injury, since it may prevent mitochondrial lipid peroxidation, increase ATP, and eventually improve energy metabolism after ischemia-reperfusion.
Objective To study the effect of p38MAPK activity on tumor necrosis factor-α （TNF-α） mRNA and intercellular adhesion molecule 1 （ICAM1） mRNA expressions of isolated rabbit liver during early stage of cold preservation and reperfusion period. Methods Based on the cold preservation and reperfusion model of isolated rabbit liver, the animals were divided into inhibition group （n=12） with 3 μmol/L SB202190 (p38MAPK specificity inhibitor) in perfusate and control group （n=12） with no SB202190 in perfusate. Liver tissue samples were harvested at the time points of before resection, end of cold preservation, and different reperfusion period (10, 30, 60 and 120 min). Protein expression and activity of p38MAPK were detected by Western blot and immunoprecipitation respectively, expression of TNF-α mRNA was detected by RT-PCR, and expression of ICAM1 mRNA was detected by in situ hybridization. Results There was no obvious change of expression of p38MAPK protein in liver tissue both in two groups during the total period （P＞0.05）， and there was no statistically significant difference between two groups （P＞0.05）. At time points of end of cold preservation, 10, 30 and 60 min of reperfusion, the activity of p38MAPK in control group was significantly higher than that at the time points of before resection and 120 min of reperfusion (P＜0.01), and was also significantly higher than that in inhibition group at the same time points (P＜0.01). There was no significant difference in activity of p38MAPK among all time points in inhibition group (P＞0.05). The expressions of TNF-α mRNA and ICAM1 mRNA at the time points of before resection, end of cold preservation, and 10 and 30 min of reperfusion were significantly lower than those in 60 and 120 min of reperfusion in both two groups (P＜0.05, P＜0.01); The expressions of TNF-α mRNA and ICAM1 mRNA in inhibition group were significantly lower than those in control group at the time points of 60 and 120 min of reperfusion (P＜0.01). The activity of p38MAPK of liver tissue during cold preservation and reperfusion period was significantly correlated with the level of TNF-α mRNA and level of ICAM1 mRNA expression （r=0.996, P＜0.01； r=0.985, P＜0.01）. Conclusions These results suggest that p38MAPK pathway may regulate the expressions of TNF-α and ICAM1 at the level of transcription and the activation of p38MAPK can up-regulate TNF-α and ICAM1 expressions, which may be one of the important mechanisms to cause ischemia-reperfusion injury of isolated liver during cold preservation and reperfusion period.
【Abstract】ObjectiveOn the basis of traditional transplantation model, a successful model of pancreaticoduodenal transplantation (PDT) were established in rats, which is the foundation of basic and clinical transplantation research. Methods We improved the technique of microoperation on donor and harvested high-quality graft. The dual cuff technique was applied to end-to-end anastomose proximal part of abdominal aorta and portal vein with left renal aorta and vein of recipient, and distal part of abdominal aorta was connected with Y-tube. External secretion was performed by duodenum stoma. The PDT model was finished without blocking systemic circulation and portal vein system. Random blood glucose levels and drainage were monitored postoperatively to evaluate the function of endocrine and ectocrine. Results Thirty operations were done. The total procedure of transplantation lasted 2 hours. Moreover the operation on recipient and the reconstruction of vessels took only (26±5) and (25±5) minutes, respectively. The success rate was elevated to 100%. The ectocrine function was restored within 2 hours after operation. Except for 3 cases of non-function graft because of thrombosis in cannula, the glucose level of the remaining recipients was reduced to normal level 6 h or 24 h after transplantation. The survival rate of graft function was 90% (27/30). Conclusion This model is finished without special equipment and can recover the endocrine function in advance. It is a simple and stable model, which might be used in research of the theoretical problems involved in clinical pancreas transplantation.
Objective To investigate the maximum tolerance limit of rats to hepatic inflow occlusion with portal vein blood bypss (PBB) in normothermia. Methods First. A new animal model was established, the animal survival rate were calculated following 7 days of reperfusion after hepatic inflow occlusion of 30, 60, 90, 100, 110, 120 min or portal triad clamping (PTC) of 30 min. And then, the hepatic energy metabolism (RCR, P/O, ATP, AKBR) was studied following 30, 90, 120 min of ischemia or 1, 6, and 24 hours of reperfusion after the ischemia. According to the reversibility of the hepatic motochondrial function injury and maximum as long as a period of liver warm ischemia of all animal postoperative 7 days survial, the safe limit of rat to hepatic inflow occlusion was evaluated. Results The survival rate on postoperative 7 days was one hundred percent subjected to 30, 60 and 90 min of hepatic inflow occlusion, and 50, 30, 20 percent in 100, 110, 120 min, respectively, the survival rate in rats with 30 min of portal triad champing was about 40 percent. The parameters of hepatic motochondrial function reflecting the degree of liver damage to ischemia showed significantly different as compared to sham group. The functional lesion was exacerbated during inital reperfusion, then was restored progressively in PBB-30 min and PBB-90 min groups, but was maintained low level in PBB-120 min and PTC-30 min groups.Conclusion The 90 minutes is the maximum limit of rats to hepatic inflow occlusion in normothermia.
Objective To investigate the pathological characteristics of hepatic energy metabolism changes following hepatic inflow occlusion and the tolerant limit to ischemia in cholestatic rats.Methods On the day 7 after rats biliary obstruction, the survival rate, hepatic mitochondrial respiratory function, content of ATP, and the ketone body ratio in arterial blood were investigated following the different duration of hepatic ischemia and reperfusion with portal blood bypass.Results The survival rate on postoperative day 10 was 100%, 100% and 40% subjected to 30, 60 and 90min of hepatic vascular occlusion. The hepatic energy metabolic function was decreased markedly following ischemia, and was increased markedly on 24 hours following reperfusion subjected to 30, 60min of hepatic vascular occlusion, but it had less increase with 90min of hepatic vascular occlusion.Conclusion The hepatic energy metabolic function injury is reversible in cholestatic rats, and the rats can tolerate hepatic inflow occlusion within 60min, but the hepatic energy metabolic function injury is irreversible after 90min of hepatic occlusion.
Objective To investigate the research base and current understanding of the mechanism of ischemia-reperfusion injury (IR) to intrahepatic cholangiocytes after l iver transplantation, so as to identify the key points of the mechanism and provide references for cl inical practice. Methods We searched PubMed (1970 to 2007) and CBM(1979 to 2007). Qual ity assessment and data collection were performed by two reviewers independently. Since the baseline supplied and the measure were very different, we decided to provide a descriptive summary only. Results The earliest study on liver IR was publ ished in 1970. A total of 65 papers were included. There were 13 on cl inical studies, 35 on basic research studies; and 17 review articles. Most basic studies focus on injury mechanism: ① The physiology of bile ducts and Intrahepatic Bil iary Duct Cells(IBDC); ②the IR caused injury mechanism of IBDC during or after liver transplantation; ③ the basic injury mechanisms include: cold ischemia, warm ischemia, reperfusion, injury of bile and bile salts. Most clinical studies focused on preventive measures, including surgical and non-surgical approaches. Based on the evidence from basic research, changing the composition and perfusion methods of perfusate and protecting the specific blood supply to biliary ducts and cholangiocytes during the operation were important in preventing or reducing such an injury. Conclusion ① The heterogeneity of morphology, function, status and the special blood supply in large and small IBDC are important material base. ② Our own study indicated that simple IR or H/R was able to change the expression of MHC, MIC, DR4, DR5 and other adhesion molecules. ③ Compared to hepatic cells, hIBDC can’ t resist cold ischemia and even worse in tolerating reperfusion injury. ④ Hydrophobic bile salts will could increase the harm to bile ducts during organ preservation. ⑤ Due to the low quantity and limited quantities of clinical researches, the power of evidence was low. The evaluation indexes and baseline conditions are not unified. So the conclusions are for reference only.
Objective To investigate the expression pattern of hypoxia-inducible factor 1α (HIF-1α) in experimental secondary spinal cord injury (SSCI) in rats and its potential effects on SSCI. Methods A total of 66 SD rats (female or male) with weight (250 ± 20) g were randomly divided into 3 groups: normal control group (group A, n=6), pseudo injury group (group B, n=6), and spinal cord injury (SCI) group (group C, n=54). In group A, no treatment was given as normal control. In groupB, only laminectomy was appl ied. In group C, laminectomy was appl ied and static compression model of SCI was built at T10 level. The expression of HIF-1α was measured with HE and immunohistochemical staining in groups A, B (1 hour after pseudo injury), and C (1, 3, 6, 12 hours and 1, 2, 3, 7, 14 days after SCI). Results All rats survived to the end of the experiment. HE staining showed that the spinal tissue of groups A and B were dense and the nucleus were round and big with l ight staining and clear nucleolus. The injured neuron at 1-12 hours after SCI of group C presented pyknosis and deep eosin staining. The swelling axon with bubbles and the disintegrated and disorganized medullary sheath in white matter appeared at 1-3 days after SCI. The hyperplasia of gl ial cells were obvious and gray matter cells were broken and apoptosis with cavities in injured spinal segment was observed at 7 and 14 days after SCI. Immunohistochemical staining showed that HIF-1α was poorly expressed in group A and increased a l ittle in group B. The positive expression in group C increased at 3 hours after SCI, which was found in spinal cord anterior horn neurons and a small amount of gangl ion cells. It reached peak at 1 day, maintained at a high level during 1-3 days and then decl ined. At 14 days, it appeared only in a small amount of gangl ion cells of white matter. There was no significant difference in the number of HIF-1α positive cells between groups A and B (t=1.325, P=0.137). The number of HIF-1α positive cells at each time point in group C was more than those in groups A and B (P lt; 0.05), and there were significant differences between all time points in group C (P lt; 0.05). Conclusion The expression of HIF-1α increases after SCI, it is related to the ischemia hypoxia after SSCI, and the expression pattern was correlated with the injury time.