The damage effects of the pure tumor necrosis factor (TNF) on the normal animals were observed. Eighteeen rabbits were divided into two groups, eight in tested group and ten in control group. 0.5mg per kg of the pure rabbit TNF was given to each animal of the tested group. Results:The symptoms similar to that induced by endotoxin appeared after the TNF injection. The functions of the main organs were markedly damaged. The arterial blood pressure of most animal was low. The weight ratio of the orgen to the body was raised. The pathologic changes were similar to those of the multiple organ failure (MOF) model. Most of the animal died before the end of the experiment. The results suggest that pure TNF could indece multiple organ damages similar to those of MOF.
Objective To investigate if lactic acid can promote the expression of vascular endothelial growth factor (VEGF) in the rat retinal explants.Methods The retinas of two-week neonatal SD rats were placed onto the culture plate inserts and incubated with Dulbeccoprime;s modified Eagleprime;s medium （DMEM） plus 2% fetal bovine serum (FBS) containing 10,20,30 mmol/L of lactic acid, respectively. Each group had 24 retinas. At 24 hours after incubation, the retinas were sectioned for light microscopy and the expression of VEGF was measured by real time PCR and Western blot. Results The cultured retinas maintained intact construction, and no cytolysis and apoptosis were observed under light microscope. RT-PCR showed the levels of VEGF mRNA were 0.74plusmn;0.06 for 10 mmol/L lactic acid group, 0.99plusmn;0.12 for 20 mmol/L group, and 1.45plusmn;0.17 for 30 mmol/L group respectively. VEGF expression was 0.34plusmn;0.15 for 10 mmol/L, 0.54plusmn;0.16 for 20 mmol/L, and 0.93plusmn;0.23 for 30 mmol/L group respectively by Western blot. Both PCR and Western blot showed 30 mmol/L of lactic acid significantly increased the levels of VEGF mRNA and VEGF expression. Conclusion The induction of retinal VEGF by lactic acid is concentration-dependent.
Standard venographies were pcrformed to evaluate the endothelial damage by the contrast medium. After different time intervals, the local veins were prepared for transmission and scanning electron microscopy (TEM and SEM) investigation. The veins were in a dilated state after the angiographies, which lasted for about two days. The endothelial damage was most severe 1 day after the venography. Besides the lesions of extensive endothelial tissurs, dcsquamations, and the exposure of subendothelial tissues, microthrombi somethimes were found. Healing occurred within 3 days. The results this study has also verifieed that it was more valuable to study venogqaphic effects on veins with TEM and SEM.
Objective：To observe the protective effect of ginkgo bilo ba extrac t (EGb 761), a free radical scavenger, on the photoreceptor cells after lighti nduced retinal damage. Methods：Seventytwo female SpragueDa wley (SD) rats we re randomly divided into 4 groups: normal control group, lightinduced retinal da m age model group, model+physiological saline group, and model+EGb 761 group, with 18 rats in each group. All of the rats except the ones in the control group were exposed to white light at (2740plusmn;120) lx for 6 hours after the dark adap tation for 24 hours to set up the lightinduced retinal damage model. Rats in m o del + physiological saline group and model+EGb 761 group were intraperitoneall y injected daily with physiological saline and 0.35% EGb 761 (100 mg/kg), respec tively 7 days before and 14 days after the light exposure. Apoptosis of photorec eptor cells was detected 4 days after light exposure; 7 and 14 days after light exposure, histopathological examination was performed and the layer number of ou ter nuclear layers (ONL) on the superior and inferior retina was counted. Results：Four days after light exposure, the apoptosis of photorecep tor cells was fou nd on ONL in model, model+ physiological saline and model+EGb 761 group, and w as obviously less in model + EGb 761 group than in model and model+physiologic al saline group. Seven days after light exposure, the layers of ONL on the super ior retina were 3 to 4 in model and model+physiological saline group, and 7 to 8 in model+EGb 761 group; the mean of the layer number of ONL in model+EGb 761 group (6.92plusmn;0.82) was less than that in normal control group (8.40plusmn;0.95) (t=-1.416, P＜0.05), but significantly more than that in model (5.96 plusmn;1.36 ) and model+physiological saline group (5.90plusmn;1.40）（t=1.024, 1.084; P＜0.05). Fourteen days after light exposure, the layers of ONL on the superior retina were 0 to 1 in model and model+physiological saline group, and 3 to 4 i n model+EGb 761 group. The mean of the layer number of ONL in model+EGb 761 group (5.5 2plusmn;1.06) was significantly more than that in model (3.44plusmn;2.15) and model + physiological saline group (3.37plusmn;1.91) (t=2.082, 2.146, P＜0.05). Conclusion：EGb 761 can partially inhibit the apoptosis of pho toreceptor cells, thus exert protective effect on photoreceptor cells.
ObjectiveTo investigate the influence of Ataxia-telangiectasia mutated (ATM) activation on cellular oxidative stress induced by high glucose in bovine retinal capillary endothelial cells(BRECs). Methods The BRECs were treated by different culture medium with various glucose concentrations (5 mmol/L glucose, 30 mmol/L glucose, 30 mmol/L glucose+10 μmol/L KU55933) as normal glucose group, high glucose group and treatment group respectively.After the cells incubated for 48 hours, the protein expression of ATM, P-ATM, Mitogen-Activated Protein Kinase P38(P38), P-P38, Extracellular signal-regulated kinases(ERKs), P-ERKs was detected by Western blot; cellular ROS level was detected by Reactive Oxygen Species Assay Kit; propidium iodide/Hoechst staining was used for analysis of apoptosis; the expression of vascular endothelial growth factor (VEGF) in the supernatant was determined by Enzyme-Linked Immunosorbent Assay (ELISA); the paracellular permeability between endothelium cells was detected by FITC-dextran. ResultsCompared with the protein level of P-ATM, P-P38 and P-ERKs in high glucose group increased. Especially, P-P38, P-ERKs expressed much more than in high glucose group. The secretion of VEGF in high glucose group was higher than that in the normal glucose group but less than that in treatment group. The same tendency existed in ROS assay, apoptosis assay and paracellular permeability measuring. ConclusionsHigh glucose induced altered activation of ATM which might play a protective role in cellular oxidative stress. Deficiency of ATM might lead to ROS explosion, cell apoptosis and dysfunction of endothelial barrier. The mechanism might be associated with P38, ERKs and VEGF.
Objective To investigate the effects of lights with different wavelength on the retina of rd12 and C57BL/6J mice. Methods Thirty two rd12 mice and C57BL/6J mice were randomly divided into the control group, white light group, midwavelength light (505 nm) group and shortwavelength light (405 nm) group, with eight mice in each group. Besides the control group, other groups were exposed to cycle illuminations ［12 hours dark, 12 hours (800plusmn;130) Lux］ for seven days to establish the model of retinal light damage. Electroretinogram (ERG) responses of all mice were recorded at the day before illumination and 1st, 4th and 7th days after illumination. The eyes were enucleated at 7th days after illumination to assess levels of reactive oxygen species (ROS), expression of peroxiredoxin 6 (PRDX6), and activity of caspase-3. Results ERG amplitudes of all groups declined gradually in C57BL/6J mice, and the most significant effects was found in the short-wavelength light group. The amplitudes of photopic b-wave were significantly different at 1st, 4th and 7th days (F=4.412, 5.082, 9.980；P＜0.01). The amplitudes of cone b-wave of the four groups decreased to (85plusmn;10) %, (70plusmn;19) %, (57plusmn;22) % and (46plusmn;19) % at 7th days, respectively, and were significantly different between white light group and short-wavelength light group(t=3.19,P＜0.01). The levels of ROS were significantly different in rd12 mice (F=16.08,P＜0.01), and elevated obviously in shortwavelength light group. The expressions of PRDX6 of retina were significantly different in rd12 mice (F=7.214,P＜0.05), and were decreased obviously in short-wavelength light group. The caspase-3 relative activity was significantly different in rd12 retina (F=7.530,P＜0.05); but there was no significant difference in C57BL/6J mice (F=3.625, 1.993, 1.133; P＞0.05).The caspase-3 relative activity were significant different between rd12 mice and C57BL/6J mice in short wavelength light group (t=5.474,P＜0.05). Conclusions Short-wavelength light can induce retinal damage of mouse retina, especially in rd12 mouse. The retinal light damage possibly relates to the oxidative damage.
From the results of this experiment, it showed that the implanted tendon was gradually extruded from the tibia hole and attached to the periosteum. The dominant breeding of tissue cells, cytodynamics, the perimeter ratio of tendon/bone and the effect of revascularization were discussed in detail.
Objective To evaluate the effect of integrin-linked kinase (ILK) in the process of retinal neovascularization induced by vascular endothelial growth factor (VEGF). Methods The ILK activities of retinal choriodal endothelial cell line RF/6A were inhibited by LY294002 or siRNA knockdown. VEGF-induced changes of cell adhesion, proliferation, migration and endothelial cell tube-formation were measured then. The in-vivo effects of ILK were also assessed by intraperitoneal injection of LY294002 into an animal model of RNV. Results The cell adhesion measurements of control group, VEGF group, VEGF＋LY294002 group and VEGF＋siRNA group were 0.0726plusmn;0.01961, 0.1137plusmn;0.02631, 0.0837plusmn;0.01503 and 0.0853plusmn;0.02454 , respectively. The difference was statistically significant between VEGF group and control group（t =4.211，Plt;0.01）, and between (VEGF＋LY294002) group or (VEGF＋siRNA) group and control group (t =3.074, 2.91，Plt;0.01). The cell proliferation results of control group, VEGF group and VEGF＋LY294002 group were 0.4162plusmn;0.1392, 0.6412plusmn;0.2420, 0.4476plusmn;0.1834 , respectively. The difference was statistically significant between VEGF group and control group（t=2.608，Plt;0.05）, and between (VEGF＋LY294002) group and VEGF group（t=2.244，Plt;0.05）.The cell migration results of control group, VEGF group and VEGF＋LY294002 group were 83.66plusmn;30.283, 248plusmn;74.748, 138.5plusmn;38.167, respectively. The difference was statistically significant between VEGF group and control group（t=5.436，Plt;0.01）, and between (VEGF＋LY294002) group and VEGF group（t=3.682，Plt;0.01）. There was no obvious tube-formation after ILK activity was inhibited or knocked down. The non-perfusion areas were increased from （62798plusmn;16995.62）mu;m2 to （84722.65plusmn;10435.01）mu;m2 after intraperitoneal injection of LY294002 into animal model of RNV, the difference was statistically significant（t=3.476，Plt;0.01）. Conclusions ILK may play an important role in the process of VEGF-induced retinal neovascularization by regulating the cellular adhesion, proliferation, migration and tube-formation, as all those cellular functions were supressed obviously after the ILK activity was inhibited by LY294002 or the ILK expression was knocked down by siRNA.
Three different methods of electrocautery were used to study the effects of electrocoagu-lation on limbs and intraabdominal blood vessel of 6 rabbits. These methods are non-touching, touching and segmental electrocoagulation. The results show that all three methods can satisfactorily stop bleeding of the blood vessel which is smaller than 1. 5mm in diameter. For arteries with the diameter 1.5～2.0mm. the effect of segment electrocoagulation is better than the other methods because it has a long burn end after cautery.
ObjectiveTo observe the morphological characteristics of photoreceptor necroptosis in experimental retinal detachment, and explore the mechanism. MethodsA total of 60 Sprague-Dawley male rats were included in this study. Retinal detachment were induced in the right eyes with 1% sodium hyaluronate (50 μl) injection (experimental group), while the left eyes received no treatment (control group). At 3 days after modeling, the morphological characteristics of photoreceptor cell were observed by electron microscopy. Cleaved Caspase 8 and phosphorylation receptor-interacting protein 1 (p-RIP1) were measured by Western blot and immunoprecipitation. ResultsAt 3 days after modeling, photoreceptor necroptosis showed the following morphological features: chromatin condensation, severe vacuolation, early loss of plasma membrane integrity, and many autophagosomes. Western blot showed that the protein expression of cleaved Caspase 8 were 0.78±0.03, 0.06±0.01 in experimental group and control group respectively, which was significantly different (F=4 023.21, P < 0.05). Immunoprecipitation showed that the protein expression of p-RIP1 were 0.23±0.03, 0.14±0.02 in experimental group and control group respectively, which was significantly different (F=56.44, P < 0.05). ConclusionsPhotoreceptor necroptosis showed chromatin condensation, severe vacuolation, early loss of plasma membrane integrity, and many autophagosomes. Necroptosis activation was associated with the increase of RIP1 phosphorylation.