ObjectiveTo dynamically observe the effect of N-acetylserotonin (NAS) on the expression of tumor necrosis factor-α (TNF-α) protein in retina of retinal ischemia reperfusion injury (RIRI) rats, and to explore the mechanism.MethodsBy using random number table method, 90 healthy male Sprague-Dawley rats were divided into sham operation group (n=10), RIRI group (n=40), and NAS group (n=40). The right eye was as the experimental eye. In the RIRI group and NAS group, the anterior chamber high intraocular pressure method was used to establish the RIRI model. In the NAS group, 10 mg/kg NAS was injected intraperitoneally before modeling and 30 minutes after modeling. At 6, 12, 24, 72 h after modeling, hematoxylin-eosin staining was used to observe the pathological changes of the retina, and the retinal ganglion cells (RGC) were counted. Each group was detected by immunohistochemical staining and Western blot about the relative expression of TNF-α, nuclear factor E2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) protein in the rat retina. One-way analysis of variance was used for differences between groups. The general linear regression method was used to analyze the correlation between the relative expression changes of TNF-α protein and the changes of Nrf2 and HO-1 protein expression after NAS intervention.ResultsOptical microscope observation revealed that the retinal edema of rats in the RIRI group was observed at 6, 12, and 24 h after modeling; the thickness of the retina in the NAS group was significantly thinner than that in the RIRI group, and the difference was statistically significant (F=9.645, 477.150, 2.432; P＜0.01). At 6, 12, 24, and 72 h after modeling, the retinal RGC counts in the NAS group were significantly higher than those in the RIRI group, and the difference was statistically significant (F=12.225, 12.848, 117.655, 306.394; P＜0.05). The results of immunohistochemical staining and Western blot showed that 6 h after modeling, the relative expression of TNF-α protein in the retina of the RIRI group increased significantly compared with that in the sham operation group, reaching a higher level at 12 h, and decreased at 24 and 72 h. But all were significantly higher than the sham operation group, the difference was statistically significant (immunohistochemical staining: F=105.893, 1 356.076, 434.026, 337.351; P＜0.01; Western blot: F=92.906, 534.948, 327.600, 385.324; P＜0.01). At different time points after modeling, the relative expression of TNF-α protein in the retina of the NAS group was significantly lower than that of the RIRI group (immunohistochemical staining: F=15.408, 570.482, 21.070, 13.767; P＜0.05; Western blot: F=12.618, 115.735, 13.176, 111.108; P＜0.05), but still higher than the sham operation group (immunohistochemical staining: F=40.709, 151.032, 156.321, 216.035; P＜0.01; Western blot: F=33.943, 79.729, 74.057, 64.488; P＜0.01), the difference was statistically significant; 12 h after modeling, Nrf2 in the retina of the NAS group (immunohistochemical staining: F=51.122, P＜0.05; Western blot: F=33.972, P＜0.05), HO-1 (immunohistochemical staining: F=30.750, P＜0.05; Western blot: F=18.283, P＜0.05) protein relative expression was significantly higher than that of RIRI group, and the differences were statistically significant. The results of linear regression analysis showed that the difference in the number of TNF-α+ cells in the RIRI group and the NAS group was negatively correlated with the difference in the number of Nrf2+ and HO-1+ cells (r2=0.923, 0.936; P＜0.01).ConclusionsNAS can inhibit the expression of TNF-α protein in the retina of RIRI rats and reduce RIRI. The mechanism may be related to the Nrf2/HO-1 pathway.
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.
ObjectiveTo observe the effects of overexpression of S100A4 protein on retinal capillary cells and retinal ganglion cells (RGC) after retinal ischemia-reperfusion injury (RIRI). MethodsOne hundred healthy adult male C57BL/6 mice were randomly divided into normal control group (group C), RIRI group, adeno-associated virus (AAV2)-S100A4 green fluorescent protein (GFP) intravitreal injection group (group S), RIRI+AAV2-GFP intravitreal injection group (group GIR), and RIRI+AAV2-S100A4-GFP intravitreal injection group (group SIR), with 20 mice in each group. The RIRI model was established using the high intraocular pressure anterior chamber method in the RIRI, GIR and SIR groups of mice. Eyes were enucleated 3 days after modelling by over anaesthesia. The number of retinal capillary endothelial cells and pericytes in the retinal capillaries of mice in each group was observed by retinal trypsinised sections and hematoxylin-eosin and periodic acid-Schiff staining; immunofluorescence staining was used to observe endothelial cell, pericyte coverage and RGC survival; The relative expression of Toll-like receptor 4 (TLR4), p38 MAPK and nuclear factor erythroid 2-related factor 2 (NRF2) in retinal tissues was measured by Western blot. One-way analysis of variance was used to compare data between groups. ResultsThree days after modeling, the endothelial cell to pericyte ratio in group C was compared with group S and SIR, and the difference was not statistically significant (F=106.30, P＞0.05); the SIR group was compared with group RIRI and GIR, and the difference was statistically significant (F=106.30, P＜0.000 1). Comparison of endothelial cell coverage in each group, the difference was not statistically significant (F=3.44, P＞0.05); compared with the pericyte coverage in group C, the RIRI group and the GIR group were significantly lower, and the difference was statistically significant (F=62.69, P＜0.001). Compared with the RGC survival rate in group C, it was significantly lower in RIRI and GIR groups, and the difference was statistically significant (F=171.60, P＜0.000 1); compared with RIRI and GIR groups, the RGC survival rate in SIR group was significantly higher, and the difference was statistically significant (F=171.60, P＜0.000 1). The relative expression levels of TLR4, p38 and NRF2 proteins were statistically significant among all groups (F=42.65, 20.78, 11.55; P＜0.05). ConclusionsPericytes are more sensitive to ischemia than endothelial cells after retinal RIRI in mice, and early vascular cell loss is dominated by pericytes rather than endothelial cells. The overexpression of S100A4 protein protects against loss of pericytes and RGC after RIRI by inhibiting the TLR4/p38/NRF2 signaling pathway.
Objective To study the effect of dexamethasone to protect flaps from an ischemia-reperfusion injury and elucidate its mechanism of regulating the death course of the neutrophils.Methods The rats were randomly divided into 3 groups.The vein of the rat was clamped for 8 h after the flap had formed. Group A: the normal flap; Group B: the saline control flap; Group C: the treatment flap with dexamethasone. The survival area of the flaps was measured at 7 days; the apoptotic and necrotic neutrophils,tumor necrosis factor α （TNF-α）, and interleukin 10 （IL-10） concentrations were measured. Results The flap survival areas in Groups A and C were larger than those in Group B. The apoptotic neutrophils in Group B were fewer than those in Groups A and C on the 1st and 3rd days after operation; however, they were more in number in Group B than in groups A andC on the 6th day. The necrotic cells in Group B were more in number than those in Groups A and C. In Group B, the plasma TNF-α concentration reached the maximum level at 1 h,while the IL-10 level reached the lowest 3 h after the reperfusion. In Group C, the TNF-α concentration was lower than that in Group B and decreased dramatically at 6 h. The IL-10 concentration was the lowest at 1 h, and increased rapidly at 3 h. Thus, ischemia reperfusion could injure the flaps, probably through the abnormal action of the neutrophils, such as the disordered secretion of the cytokines and abnormal death course of the neutrophils. Conclusion Dexamethasone can protect the flap from an ischemia-reperfusion injury by its regulation for the neutrophil function.
We established acute cholangitis and endotoxiemia in 18 rabbits by ligating the common bile duct and injecting E coli(O111B4 strain)into the common bile duct. After perfusion through activated charcoal via femoral artery-vein pathway, the average blood levels of endotoxin decreased sighificantly from 2.24Eu/ml to 0.17Eu/ml(Plt;0.001). This result suggested that blood perfusion through activated charcoal may be a promising therapy for acute endotoxemia.
Objective To investigate the clinical effects and the brain protection effect of different cardiopulmonary bypass in treating descending aortic aneurysms. Methods From January 2001 to December 2008, 65 patients were diagnosed to have descending aortic aneurysm with magnetic resonance imaging (MRI) in our hospital. Among them, there were 56 males and 9 females whose age was between 15 and 71 years old with an average of 48.1 years. The disease process ranged from 6 days to 4 months (19.0±6.5 d ). Preoperative diagnosis showed that there were 41 cases of DeBakey type Ⅲinterlayer, 9 cases of Marfan syndrome with postoperative complications of type Ⅲ interlayer, 7 cases of pseudoaneurysm and 8 cases of true aneurysm. We adopted artificial blood vessel repair patch to repair the damaged point of the descending aorta in 2 cases, performed vascular aneurysm resection and artificial vessel replacement on 63 patients, and carried out descending aorta replacement and intercostal artery grafting in 18 cases. Results Among the 65 cases of cardiopulmonary bypass patients, there were 13 cases of left heart bypass, 12 cases of heart bypass, 30 cases of deep hypothermic circulatory arrest (DHCA) with total body retrograde perfusion (TBRP) and 10 cases of modified separate perfusion of upper and low body. Cardiopulmonary bypass time, DHCA time, retrograde perfusion time, upper body circulatory arrest time and low body circulatory arrest time were respectively 51-212 min, 18-75min, 18-73 min, 21-31 min, and 39-67 min. No death occurred during the operation, and there were no brain complications or complications of paralysis among all the patients. Two patients died after operation because of renal failure. Conclusion Good results can be achieved by selecting different method of cardiopulmonary bypass based on the anatomical location and range of the thoracic descending aortic aneurysms. The selection criteria should be favorable to the surgical operation and organ protection.
ObjectiveTo observe the effect of Crocin on structure and the expression of tumor necrosis factor-alpha; (TNF-alpha;) and interleukin-1beta; (IL-1beta;) in rat retina after injury by ischemia-reperfusion. Methods A total of 80 Sprague-Dawley male rats at the age of 8 -10 weeks were divided into control group, model group, low-dose Crocin group and high-dose Crocin group, with 20 rats in each group. The rats of control group were not treated. The rats in model, low-dose Crocin and high-dose Crocin group were induced with normal saline by anterior chamber perfusion creating a retinal ischemia-reperfusion (RIR) model. The rats of the low-dose Crocin and highdose Crocin group received intraperitoneal injection with different doses of Crocin solution (5 mg/kg, or 50 mg/kg) 30 minutes prior to ischemic injury and one time per day after successful RIR. Optical microscopy was used to observe the retinal structure. Enzymelinked immunosorbent assay (ELISA) was used to measure the expression of TNF-alpha; and IL-1beta; 6, 12, 24 and 48 hours after RIR. ResultsThe retinal structure of control group was normal. Pathological changes were found in the RIR model and low-dose Crocin group, such as retinal edema, disorganized structure and loosely packed cells. The degree of pathological changes in lowdose Crocin group was less than the RIR model group. The retinal structure of high-dose Crocin group was similar to the control group. The expression of TNF-alpha; was the highest at 24 hours after modeling, while the expression of IL-1beta; was the highest at 12 and 48 hours after RIR modeling. Six, 12, 24 and 48 hours after RIR modeling, compared with the control group, the TNF-alpha; expression of model (t=5.42, 7.94, 9.32, 9.18;P＜0.05 ), low-dose Crocin (t=3.94, 4.12, 4.98, 3.84;P＜0.05) and high-dose Crocin group (t=2.13, 2.34, 2.96, 2.78;P＞0.05) were increased. Compared with the RIR model group, the TNF-alpha; expression of low-dose Crocin (t=3.95, 4.56, 4.01, 5.12) and high-dose Crocin group (t=5.23, 7.65, 7.74, 7.63) was decreased. Compared with the control group, the IL-1beta; expression of model (t=7.23, 7.87, 7.15, 15.60), low-dose Crocin (t=5.65, 5.10, 5.54, 6.87;P＜0.05) and high-dose Crocin group (t=4.38, 5.21, 4.56, 4.75) was increased (P＜0.05). Compared with the model group, the IL-1beta; expression of low.dose Crocin group was decreased significantly 48 hours after RIR modeling (t=7.56,P＜0.05); but it decreased significantly at each time point in high-dose Crocin group (t=6.94, 5.36, 6.05, 10.50;P＜0.05). Conclusion Crocin can improve the retinal pathologic changes, while down-regulating TNF-alpha; and IL-1beta; expression in RIR rats.
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...
ObejctiveTo investigate the consistency and reproducibility of macular perfusion parameters in early diabetic retinopathy (DR) using optical coherence tomography angiography (OCTA).MethodsA prospective cross-sectional observational study. Forty-six patients (46 eyes) diagnosed with mild nonproliferative DR were included in this study. There were 24 males and 22 females, with the mean age of 59.16±10.32 years. Two macular scan sizes of 3 mm×3 mm and 6 mm×6 mm were performed by the same operator, and the same test was performed by another operator. The superficial retinal layer (SRL) and deep retinal layer (DRL) in the foveal avascular zone (FAZ) and vessel density (VD) were quantified. The consistency of the two scan sizes and the reproducibility of the same scan size were also evaluated. The consistency was determined by the intraclass correlation coefficient (ICC). If the intraclass correlation coefficient (ICC)＞0.80, consistency was good; if 0.4≤ICC＜0.8, consistency was general; if ICC＜0.40, consistency was poor.ResultsIn the 3 mm×3 mm and 6 mm×6 mm scanning sizes, the mean results of the two examiners were calculated. The FAZ of SRL were 0.39±0.13 mm2 and 0.42±0.15 mm2, FAZ of DRL were 0.74±0.22 mm2 and 0.89±0.23 mm2. The VD of SRL were (32.23±2.86)% and (31.91±3.01)%, VD of DRL were (43.73±4.64)% and (45.12±5.49)%. The consistency analysis showed that the ICC of SRL-FAZ and DRL-FAZ were 0.920 and 0.812, respectively; the ICC of VD were 0.833 and 0.830, respectively. The consistency was good. The reproducibility analysis of different examiners in the same scan size was better in the consistency of SRL FAZ and VD.ConclusionOCTA in two scanning sizes to measure FAZ and VD of early DR has good consistency and reproducibility.