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find Keyword "death" 138 results
  • Nerve growth factor prevents apoptosis induced by indomethacin in cultured human fetal retinal pigment epithelial cells

    Objective To investigate the protective effect of nerve growth factor (NGF) on apoptosis of cultured human fetal retinal pigment epithelium (HFRPE) cells induced by indomethacin (IN) in vitro.Methods Subcultured HFRPE cells were treated with different concentrations of IN to establish apoptotic model. The protective effect of NGF on apoptosis of cultured HFRPE cells were assessed using an acridine orange (AO) staining method and transmission electron microscopy (TEM).Results HFRPE cells exposed by 200-600 μmol/L IN for 24 hours elicited typical apoptosis morphological changes, including condensed chromation, nuclear fragmentation and reduction of nuclear size and cell volume. There was a statistically difference in HFRPE cells with apoptosis between 200 μmol/L IN+500 μg/L NGF and 200 μmol/LIN groups ( q=3.9204,P=0.0320); there was a significant difference in HFRPE cells with apoptosis in 400 μmol/L IN+500 μg/L NGF and 400 μmol/ L IN as well (q=9.7915,P=0.0001). Conclusion NGF has an protective effect on IN-induced HFRPE cells apoptosis. (Chin J Ocul Fundus Dis,2003,19:38-41)

    Release date:2016-09-02 06:00 Export PDF Favorites Scan
  • Photoreceptor cell apoptosis of rat’s retina induced by N-methyi-N-nitrosourea

    Objective To investigate the mechanism of the toxic effect of N methyl N-nitrosourea (MNU) on photoreceptor cell apoptosis of rat’s retina. Methods Thirty 50-day-old female Sprague-Dawley ( SD ) rats were intraperitoneally injected with MNU (60 mg/kg) and were put to death by dislocation of cervical vertebra 12, 24, 48, and 72 hours and 7 days after the injection, respectively. The photoreceptor cell apoptosis was detected by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) and transmission electron microscope. The expression of proliferating cell nuclear antigen (PCNA), vimentin and glial fibrillary acidic protein (GFAP) was detected at different time after injection by immunohistochemical methods. Results The apoptotic index of the retina in the posterior pole was (33. 6±2. 3), (46. 5±5. 7), (20. 1±5. 3), (8. 2±3. 6) and (2. 5±1. 3~//oo at the 12th,24th, 48 th, and 72nd hour and on the 7th day, respectively, after injection. Karyopyknosis was found in most photoreeeptor cells 24 hours after injection. The expression of PCNA was found in internal granularlayer and between internal granular layer and choroid 24 hours after injection, reached the peak after 72 hours, and reduced obviously after 7 days. The positive expression of GFAP and vimentin was found in internal and external granular layer 24 hours after injection, reached the peak after 72 hours, and reducedobviously after 7 days.Conclusion MNU may selectively lead the photoreceptor cell apoptosis and proliferation of Mvller cells. (Chin J Ocul Fundus Dis,2004,20:33-36)

    Release date:2016-09-02 05:58 Export PDF Favorites Scan
  • Interference effect of nerve growth factor on apoptosis of retinal cells in experimental retinal detachment

    Objective To investigate the interference effect of nerve growth factor (NGF) on apoptosis of retinal cells in experimental retinal detac hment (RD). Methods Twenty seven Sprague-Dawely rats were selected, and the left and right eyes were in the experimental control group and NGF group, respectively. After the RD model was set up by subretinal injection with sodium hyaluronate, 5mu;l NGF(1mu;g/mu;l)was injected into the vitreous body of the right eyes which were in the NGF group; 5mu;l PBS was injected into vitreous body of left eyes which were in the experimental control group. The injection was performed once every 4 days till the end of the observation period. The eye balls of the 27 rats were extrafted 1.5, 3, 6, 12 hours, 1 day, 2, 4, 8 , 16, and 32 days after the RD model was established. Another 2 rats were selected as the normal control, which underwent none of the injections but eyeball extraction at the end of the observation period. TUNEL and transmission electron microscopy were used to detect the apoptosis of the retinal cells. Cell counts and statis tical analysis were used to assess results. Results Typical apoptosis cells were observed in the early time of RD. Apoptosis was found in each retinal layers, especially in inner and outer nuclear layers. The number of apoptosis cells increased as the time of RD was prolonged(Plt;0.01). It was also found that apoptosis cells in NGF group were less than that in the experimenta l control group(Plt;0.01). Conclusion Intravitreous injection exogenous NGF may inhibit the apoptosis of retinal cells in experimental RD. (Chin J Ocul Fundus Dis, 2006, 22: 333-335)

    Release date:2016-09-02 05:51 Export PDF Favorites Scan
  • The effect of visible light on apoptosis of cultured human retinal pigment epithelium cells

    Objective To observe the effect of visible light on apoptosis of cultured human retinal pigment epithelium (RPE) cells. Methods Being the light source,500lx,(2 000±500)lx and (3 400±200)lx cold white light were used. The duration of exposure was 0,6,12 and 24 hours respectively. Apoptosis was detected by terminal deoxynucleotidyl transferase mediated dUTP nick end labelling, Annexin V-flunorescein isothiocyanate/Propidium iodium labelling and flow cytometry. Results Apoptosis and necrosis were found in cultured human RPE cells which were exposed to visible light.(1)A significant increase in apoptotic and necrotic percentages was consistent with a higher light intensity.(2)Apoptosis was the main response to shorter (6 h and 12 h) exposure duration,while necrosis was more pronounced correlated to the prolongation of post-exposure culture (P<0.05),and the longer the post-exposure period was, the more apoptotic necrosis were seen.Thirty-six hours after exposure the necrotic percentages were more pronounced (P<0.01). Conclusions Visible light (>500 lx) increases the proportion of apoptosis and necrosis of human RPE cells in vitro.The extent is related to exposure intensity and duration. It demonstrates that the lower intensity and the shorter duration of exposure to light are, the more pronounced apoptotic percentages are observed,otherwise necrosis. (Chin J Ocul Fundus Dis, 2002, 18: 227-230)

    Release date:2016-09-02 06:01 Export PDF Favorites Scan
  • Expression of PD-1/PD-L1 in esophageal squamous cell carcinoma and its relationship with survival prognosis: A systematic review and meta-analysis

    ObjectiveTo systematically evaluate the expression of programmed cell death receptor 1 (PD-1) and programmed cell death ligand 1 (PD-L1) in esophageal squamous cell carcinoma and its relationship with prognosis.MethodsThe literature from PubMed, EMbase, The Cochrane Library, Web of Science, CNKI and Wanfang data from inception to February 22, 2020 was searched by computer. Data were extracted and the quality of literature was evaluated using RevMan 5.3 software for meta-analysis. Egger's and Begg's tests were used to evaluate publication bias, and Stata 15.1 software was used for sensitivity analysis.Results A total of 16 articles were included, and there were 3 378 patients with esophageal squamous cell carcinoma. The methodological index for nonrandomized studies (MINORS) scores were all 12 points and above. The meta-analysis results showed that the positive expression rates of PD-1 and PD-L1 in tumor cells were 37.8% (190/504) and 41.7% (1 407/3 378), respectively. The positive expression of PD-L1 in tumor immune infiltrating cells was 41.7% (412/987). The overall survival (OS) of the tumor cell with high PD-L1 expression was lower than that with low PD-LI expression (HR=1.30, 95%CI 1.01-1.69, P=0.04). The OS of the tumor immune infiltrating cell with high PD-L1 expression was significantly higher than that with low PD-LI expression (HR=0.65, 95%CI 0.53-0.80, P<0.0001).ConclusionPD-L1 has a high expression rate in esophageal squamous cell carcinoma and is an important factor for the prognosis of esophageal squamous cell carcinoma.

    Release date:2021-11-25 03:54 Export PDF Favorites Scan
  • Progress of programmed death-1/programmed death ligand-1 inhibitors for esophageal cancer

    Immunotherapy is an important treatment method in tumor therapy. Among them, programmed death-1/programmed death ligand-1 inhibitors are the immune preparations with mature application and great survival benefit at present. Programmed death-1/programmed death ligand-1 inhibitors brought better clinical benefits to patients with esophageal cancer and provided more favorable choice for the treatment of esophageal cancer. This article introduces the mechanism of action, application in esophageal cancer, and efficacy predictors of programmed death protein-1/programmed death protein ligand-1 inhibitors, aiming to provide a theoretical basis for the more rational use of programmed death protein-1/programmed death protein ligand-1 inhibitors in patients with esophageal cancer.

    Release date:2020-11-25 07:18 Export PDF Favorites Scan
  • Apoptosis of photoreceptors in the early stage of siderotic retinopathy in rat

    Objective To demonstrate if apoptosis is one of the mechanisms of siderotic retinopathy. Methods Autoclaved iron particles were implanted in the vitreous cavities of 32 eyes of SD rats.Glass chips were implanted in 10 control eyes.The experimental eyes were enucleated at various time intervals from days 1 to 15.Retinal degeneration was examined using the TdT-mediated,dUTP-biotin nickend labeling(TUNEL)method.Electrophoresis on agarose gel was used to detect internucleosomal DNA fragmentation.Results TUNEL-positive nuclei were observed only in the outer nuclear layer beginning on day 2.The nuclei spread throughout the outer nuclear layer by the end of day 3.No TUNEL-positive nuclei were observed in other layers throughout the experimental perios.Analysis of DNA,extracted from the retinas by electrophoresis on agarose gel,revealed a typical ladder pattern of internucleosoma DNA cleavage in the experimental eyes.ConclusionApoptosis of photoreceptors occurs at the early phase of iron-induced retinopathy in the rats.

    Release date:2016-09-02 06:01 Export PDF Favorites Scan
  • Organ Procurement Process for Organ Donation after Cardiac Death

    Objective To summarize and further investigate the initial experience of organ procurement process for organ donation after cardiac death (DCD). Methods The clinical data,the selected standard,and the organ procurement process of 28 cases of DCD from July 2009 to January 2012 in the liver transplantation center of Guangzhou General Hospital were reviewed and analyzed. Results Twenty-eight cases of DCD all had donated organs successfully. Among these cases,there were 3 cases (10.7%) of the Maastricht Ⅲ, and one case (3.6%) of the Maastricht Ⅳ,and 24 cases (85.7%) of the organ donation after brain death plus cardiac death (DBCD).Three cases of the Maastricht Ⅲ were practiced the organ procurement process of DCD.One case of the Maastricht Ⅳ was practiced the organ procurement process of DBCD without the extracorporeal membrane oxygenation (ECMO).Twenty-four cases of DBCD were practiced the organ procurement process of DBCD with the ECMO.The donator warm ischemic time was zero min in DBCD,18 min in Maastricht Ⅳ,and mean 25 min (22-28 min) in MaastrichtⅢ.All the donated organs included 28 livers,40 kidneys,and 2 hearts.And all these organs had been practiced the liver transplantation,the kidney transplantation,and the heart transplantation. Conclusions The organ procurement process for organ DCD includes the DCD process and the DBCD process in China,and the later includes the organ procurement process with the ECMO and without the ECMO.The ECMO could well control the warm ischemia for protecting the donors just without ethics dispute. So,the using of the ECMO for the organ DCD of citizen in China has a very important contribution.

    Release date:2016-09-08 10:37 Export PDF Favorites Scan
  • Apoptosis of photoreceptor cell in experimental rat retinal photoinjury

    Objective To further investigate pathologic mechanism of retinal phototrauma. Methods Twenty Wistar rats were divided into control and experimental groups.Their eyes were extracted in 12,24 and 36 hours after light exposure.HE stained retina samples were examined and TDT-mediated dUTP nick end labelling(TUNEL)method was employed to distinguish apoptotic cells. Results After 12-hour light exposure,slight vesiculation was observed in the rod outer segment of the retinas.After 24-hour light exposure,the outer nuclear layer showed predominant fractured and condensed nuclei and fragmented DNA.After 36-hour light exposure,the rod outer and inner segments were lysed and most of the nuclei in the outer nuclear layer were disappeared. Conclusions Apoptosis of photoreceptor cell is one of the important mechanisms which cause experimental retinal photoinjury of rats. (Chin J Ocul Fundus Dis, 1999, 15: 167-169)

    Release date:2016-09-02 06:07 Export PDF Favorites Scan
  • Expression of Fas and Fas ligand and cell apoptosis in the ischemia/reperfusion-induced retina and therapeutic effects of basic fibroblast growth factor

    Objctive To explore the relationship between the expression of Fas/FasL and the apoptosis occurs in retinal ischemia/reperfusion injury of rats , as well as the therapeutic effects of bFGF on the ischemic retina.Methods Th emodels of retinal ischemia/reperfusion injury was made by transient elevating introcular pressure. A total of 28 rats were divided into normal and operation group.The latter were subdivided into 1 hour, 6, 12, 24, 48 and 72 hours after reperfusion group, in which the left eyes of the rats were in the ischemia/reper fusion groups and the right ones were in the treatment groups (bFGF intracameral injection). Apoptosis was assessed by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labelling (TUNEL) method, and the expression of Fas and Fas ligand was studied by strept avidin-biotin complex (SABC)immunohistochemistry. Results No positive cells were observed in the normal rats′retinae, but there was a significant number of TUNEL positive cells in 6-24 hours after transient ischemia followed by a decrease at the 48th hour. The number of TUNEL positive cells reached a maximum at the 24th hour after ischemia. The expression of Fas gradually increased as early as when it was at the 6th hour, reached a peak at the 24th hour, and then decreased at the 48th hour. Similarly, the expression of Fas ligand was at peak in 24-48 hours in GCL and INL of retina. Conclusions Retinal ischemia-reperfusion after transient elevated IOP induced apoptosis of cells in the retina. Fas/FasL may play an important role in the early events of the apoptotic pathways. bFGF can rescue RGCs from retinal ischemia/reperfusion injury through downregulation of the expression of Fas/FasL and may represent an important mechanism for therapeutic neuroprotection. (Chin J Ocul Fundus Dis,2003,19:160-163)

    Release date:2016-09-02 06:00 Export PDF Favorites Scan
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