Objective To investigate the protective effects of antitumor necrosis factor-α antibody （TNF-αAb） on lung injury after cardiopulmonary bypass （CPB） and their mechanisms. Methods Forty healthy New Zealand white rabbits，weighting 2.0-2.5 kg，male or female，were randomly divided into 4 groups with 10 rabbits in each group. In groupⅠ，the rabbits received CPB and pulmonary arterial perfusion. In group Ⅱ，the rabbits received CPB and pulmonary arterial perfusion with TNF-αAb. In group Ⅲ，the rabbits received CPB only. In group Ⅳ，the rabbits only received sham surgery. Neutrophils count，TNF-α and malondialdehyde （MDA） concentrations of the blood samples from the left and right atrium as well as oxygenation index were examined before and after CPB in the 4 groups. Pathological and ultrastructural changes of the lung tissues were observed under light and electron microscopes. Lung water content，TNF-α mRNA and apoptoticindex of the lung tissues were measured at different time points. Results Compared with group Ⅳ，after CPB，the rabbitsin group Ⅰ to group Ⅲ showed significantly higher blood levels of neutrophils count，TNF-α and MDA（P＜0.05），higherTNF-α mRNA expression，apoptosis index and water content of the lung tissues （P＜0.05），and significantly lower oxyg-enation index （P＜0.05） as well as considerable pathomorphological changes in the lung tissues. Compared with group Ⅱ，after CPB，the rabbits in groups Ⅰ and Ⅲ had significantly higher blood concentrations of TNF-α （5 minutes after aortic declamping，220.43±16.44 pg/ml vs.185.27±11.78 pg/ml，P＜0.05；249.99±14.09 pg/ml vs.185.27±11.78 pg/ml，P＜0.05），significantly higher apoptosis index （at the time of CPB termination，60.7‰±13.09‰ vs. 37.9‰±7.78‰，P＜0.05；59.6‰±7.74‰ vs. 37.9‰±7.78‰，P＜0.05），significantly higher blood levels of neutrophils count and MDA （P＜0.05），significantly higher TNF-α mRNA expression and water content of the lung tissues （P＜0.05），and significantly loweroxygenation index （P＜0.05） as well as considerable pathomorphological changes in the lung tissues. Compared with groupⅠ，rabbits in group Ⅲ had significantly higher above parameters （P＜0.05） but lower oxygenation index （P＜0.05） only at 30 minutes after the start of CPB. Conclusion Pulmonary artery perfusion with TNF-αAb can significantly attenuate inflammatory lung injury and apoptosis of the lung tissues during CPB.
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)
ObjectiveTo observe the influence of heat shock protein 27 (HSP27) sensibilization to retinal ganglion cells (RGC) apoptosis of rats. MethodsThirty-five female Wistar rats were randomly divided into HSP27 sensibilization group (15 rats), borate buffer solution (BBS) control group (15 rats) and normal group (5 rats). The rats in HSP27 sensibilization group were received hypodermic injection in rear limb with 100 μg HSP27 and complete freund adjuvant, intraperitoneal injection with 1 μg pertussis toxin. The BBS control group received the same volume of BBS at the same site. The normal group received no intervention. The intraocular pressure was measured 3 days before injection and 1, 2, 4, 6, 8 weeks after injection. Four, 6 and 8 weeks after injection, the retinal frozen sections was made to observe RGC apoptosis by terminal-deoxynucleoitidyl transferase mediated nick end labeling. The anti-HSP27 level in serum and cerebrospinal fluid were detected by enzyme linked immunosorbent assay. ResultsThere was no obvious change of intraocular pressure in rats in 3 groups before injection (P>0.05). RGC apoptosis was observed in HSP27 sensibilization group 4 weeks after injection, and increased significantly at 6 weeks after injection. There was no RGC apoptosis in BBS control group and normal group. The level of anti-HSP27 in serum and cerebrospinal fluid of HSP27 sensibilization group occurred at 4 and 6 weeks after injection respectively, decreased with prolongation of injection time. Compared with BBS control group and normal group, the RGC apoptosis rate, anti-HSP27 level in serum and cerebrospinal fluid of HSP27 sensibilization group were significantly increased (P<0.05). There was no significant difference of the RGC apoptosis rate, anti-HSP27 level in serum and cerebrospinal fluid between BBS control group and normal group (P>0.05). ConclusionsHSP27 sensibilization could promote the RGC apoptosis. The variation trend of anti-HSP27 level in cerebrospinal fluid is consistent with the RGC apoptosis.
Objective To observe the outcomes of using different concentrations of arsenic trioxide at varying phases on the breast cancer cell line MCF-7 and to study the mechanism of this effect. Methods The effect of arsenic trioxide on the growth of breast cancer cell line MCF-7 was observed after applying arsenic trioxide of different concentrations （0.5-16 μmol/Ｌ）. The inhibitory effect of arsenic trioxide on the cell proliferation was investigated with 3-(4，5-dimethyl-thizazol-2-yl)-2， 5-diphenyl tetrazolium bromide (MTT) and the induction of arsenic trioxide on cell apoptosis was detected by DNA ladder and terminal deoxynucleotidyl transferase mediated nick end labeling (TUNEL). Results The effect of arsenic trioxide on breast cancer cell line MCF-7 depended on the phase and the dose. The number of cell decreased significantly and there were conspicuously typical morphological changes of apoptosis after the use of arsenic trioxide， including membrane blebbing， chromatin pyknosis, nuclear fragmentation and the formation of apoptotic body. The typical DNA ladders were observed in the MCF-7 cells after 48 h administration of arsenic trioxide at concentrations 1-8 μmol/Ｌ. Significant elevations of apoptosis index at 24 h, 48 h and 72 h were all detected by TUNEL after incubating with 4 μmol/L arsenic trioxide. Conclusion Arsenic trioxide may inhibit the growth of breast cancer cell line MCF-7 significantly by inducing the apoptosis of breast cancer cell.
Objective To investigate cell cycle as a new tool to evaluate the biocompatibility of biomaterials.Methods The cell cycle and the expression of related genes were analyzed by the methods of immunocytochemistry, protein blotting, RT PCR and flow cytometry. Results The physical properteis, chemical properties and topological properities of biomaterials could not only influence cell cycle of the cells attached onto biomaterials but also affect the expression of related genes of target cells. Conclusion As an important extension of routine proliferation epxeriments, the study of cell cycle control will be great help for us to to study the cell group as an organic society. It revealed the balance between cell proliferation, cell differentiation and apotosis. It is suggested that the study of cell cycle control will play a key role in the research of tissue engineering.
Objective To explore the effect of artemisinin on the apoptosis of pancreas acinar cells in acute pancreatitis (AP), and to study whether artemisinin can relieve the severity of AP. Methods ① In vivo experiment: twenty one Wistar rats were divided into the following 3 groups randomly: the normal control group, the AP group and the artemisinin group. The model of AP was established by injecting cerulein into the peritoneal cavity of rat. After establishment of AP in the artemisinin group, artemisinin was injected into the peritoneal cavity. Meanwhile normal saline was injected into the peritoneal cavity of rats of the normal control group and the AP group. The apoptosis of pancreas acinar cell was detected by terminal deoxynucleotidyl transferase mediated nick end labeling (TUNEL). The activity of myeloperoxidase was detected by absorption spectrometry. ② In vitro experiment: the pancreas acinar cells of normal rats were isolated through twostep enzyme digestion, and cultured. These acinar cells were divided into 3 groups: the normal control group, the AP group and the artemisinin group. Then, the cells of AP group were cocultured with cerulein, and those of the artemisinin group were cocultured with cerulein and artemisinin. The apoptosis of pancreas acinar cells were detected by AO dyeing and the measurement of the activity of caspase3. And the activity of LDH and AMS in the culture medium of each group were measured. Results ① In vivo: the apoptosis index of the artemisinin group was sigificantly increased and the activity of myeloperoxidase was obviously decreased compared with the AP group (P＜0.05). ② In vitro: the apoptosis index and the activity of caspase3 of the artemisinin group were significantly increased compared with the AP group (P＜0.05); the activities of LDH and AMS of the artemisinin group were more decreased than those of the AP group (P＜0.05). Conclusion Artemisinin could contribute to the apoptosis of rat pancreas acinar cells, decrease the releasing of trypsogen, alleviate the activation of neutrophil and relieve the severity of AP.
Objective:To observe the intervention effect of the tetra methylpyraz ine on the rds mice with retinitis pigmentosa. Methods:A total of 84 rds mice were randomly divided into 2 groups, with 42 mice in each group. The mice in the experimental group underwent intraperitoneal cavity injection with hydrochlor i c tetramethylpyrazine (80 mg/kg, twice per day) at the date of birth and till 35 days after birth, whereas the normal saline was injected into the intraperito n eal cavity of rats in the control group. The mice were sacrificed 0, 3, 7, 14, 2 1, 28, 35 days after birth, and the eyeballs were enucleated for the routine pat hologic examination with the light microscope. The apoptosis of photoreceptor ce ll nuclei was detected by terminal deoxynucleotidyl transferasemediated dUTP n i ck endlabeling (TUNEL) technigue and the expression of bcl2 in retina was de tect by immunohistochemistry method. Results:The results of li ght microscopy s howed that the layer number of retinal photoreceptor cell nuclei with tetramethy lpyrazine treatment was increased 14, 21, 28, 35 days after the treatment compar ed with that in the control group（P＜0.01）. The results of electron-micro scope suggested that tetramethylpyrazine might reduce lesions in the photoreceptor cells and the destruction of the disc member, mitochondrion，and outer limiting me mbrane in the photoreceptor outer segment in rds mice. The apoptosis of the phot oreceptor cell nuclei reduced in rds mice 3, 7, 14, 21, 28 and 35 days after the treatment compared with that in the control group （P＜0.01）. The express ion of bcl-2 in the matrix of retinal photoreceptor cell nuclei and its inner and o u ter segments increased significantly in rds mice 3，7, 14, 21, 28 and 35 days af ter the treatment （P＜0.05）. Conclusions:Tetramethylpyra zine might reduce ret inal photoreceptor apoptosis by upregulating the expression of bcl-2 in the m at rix of retinal photoreceptor cell nuclei or its inner and outer segments in rds mice.
To study the effect of the proliferation and apoptosis of Survivin-T34A mutant on breast cancer MCF-7 cell, we adopted the method of cell culture in vitro to observe the proliferation and apoptosis of the cell. In the experiment, MCF-7 cells were randomly divided into three groups and transfected with normal saline, PORF-9-null and Survivin-T34A, respectively. Breast cancer nude mouse models were established to study anti-tumor effect of Survivin-T34A in vivo. The activity of the cells in the Survivin-T34A-transfected group was lower than that in PORF-9-null group. The increase of cell apoptosis was observed under electron microscopy, meanwhile the apoptotic rate was obviously higher than that in PORF-9-null control by flow cytometry. Tumor inhibition effects of the mouse which received the injection of Survivin-T34A intratumoral injection were apparent, and the inhibition ratio was as high as 47.1%. In conclusion, Survivin-T34A mutant has anti-tumor effect through efficiently inhibiting the growth of breast cancer MCF-7 cell and actively promoting apoptosis of cancer cells.
ObjectiveTo evaluate the photoreceptor-protective effects of Cdk5 inhibitor Roscovitine on retinal degeneration in Royal College of Surgeons (RCS) rat. MethodsThe RCS rats were divided into three groups according to postnatal days: the early (17 days), medium (25 days) and late intervention group (35 days). Cdk5 inhibitor Roscovitine were used in the right eyes by intravitreal injection as experimental eyes and Roscovitine solvent dimethylsulfoxide were used in the left as control at postnatal 17, 25, 35 days. Hematoxylin-eosin (HE) staining was used to observe the thickness of outer nuclear layer. The expression of Cdk5 P25 and cleave-caspase 3 in the retina was evaluated by immunohistochemistry. The protein expression of cleave-caspase 3 in the retina was determined by Western blot. The apoptosis of retinal cells was examined by terminal-deoxynucleotidyl transferase mediated nick end labeling. ResultsHE staining showed that thickness of outer nuclear layer in the early and medium intervention groups were significantly thicker than that in the control group (P < 0.05), particularly in the early intervention group. And there was no significant change in the late intervention group (P > 0.05). The expression level of Cdk5, p25, cleave-caspase 3 in the outer nuclear layer in three intervention groups were lower than that in the control group (P < 0.05), especially in the early intervention group. ConclusionCdk5 inhibitor Roscovitine can delay the retinitis pigmentosa process in RCS rats by early, medium interventional therapy and may have a certain degree of photoreceptor-protective effects.