原花青素对血管内皮细胞过氧化氢损伤的保护作用

目的 观察原花青素对血管内皮细胞过氧化氢损伤的保护作用及可能机制.方法 用体外培养的人脐静脉内皮细胞传代后进行实验,实验分为3组:对照组常规培养;过氧化氢损伤组;药物干预组加入原花青素低、中、高浓度组(25 mg/L、50 mg/L和100 mg/L预处理).用MTT法观察原花青素对过氧化氢损伤的内皮细胞活性的影响,各组均测定细胞中超氧化物歧化酶、丙二醛和乳酸脱氢酶的活性,用Hoechst 33258荧光染色法观察过氧化氢损伤对血管内皮细胞的凋亡情况,蛋白免疫印迹法分析各组凋亡基因bcl-2蛋白的表达.结果 (1)原花青素使过氧化氢损伤的内皮细胞的脂质过氧化物丙二醛生成减少,乳酸脱氢酶漏出液减少,超氧化物歧化酶活力增加;(2)过氧化氢损伤可以诱导内皮细胞凋亡,原花青素可显著减少过氧化氢诱导的内皮细胞的凋亡,且上调抗凋亡基因bcl-2的蛋白表达.结论 原花青素处理对过氧化氢所致的内皮细胞的损伤有保护作用,机制可能通过抗脂质过氧化,对氧自由基的清除,以及抗细胞凋亡有关.     

二苯乙烯苷对过氧化氢诱导内皮细胞凋亡的影响

目的探讨二苯乙烯苷对过氧化氢诱导人脐静脉内皮细胞凋亡的影响及其可能机制。方法体外培养人脐静脉内皮细胞,以过氧化氢作用内皮细胞建立细胞凋亡模型,再加入不同浓度的二苯乙烯苷作用24 h。采用MTT法检测细胞生长活力,Hoechst33258染色观察细胞形态,流式细胞仪检测细胞凋亡率,RT-PCR、免疫印迹法检测Caspase-3的表达。结果与空白对照组相比,300μmol/L过氧化氢作用后细胞增殖明显受到抑制,Ho-echst33258染色可见大量凋亡细胞,流式细胞仪检测出明显的凋亡峰,Caspase-3的表达量显著增加;加入二苯乙烯苷作用后,与过氧化氢组比较,10μmol/L二苯乙烯苷能够显著提高细胞增殖率,抑制细胞凋亡,并且使Caspase-3的表达减少(P<0.05)。结论二苯乙烯苷能够抑制过氧化氢诱导的人脐静脉内皮细胞凋亡,其作用机制与抑制Caspase-3表达有关。     

二苯乙烯苷对H2O2诱导人脐静脉内皮细胞核因子κB、肿瘤坏死因子α表达的影响

目的 研究二苯乙烯苷对过氧化氢诱导人脐静脉内皮细胞损伤的保护作用,并探讨其作用机制.方法 以不同浓度(0.1、1、10 μmol/L)的二苯乙烯苷孵育体外培养人脐静脉内皮细胞 4 h后,用200 μmol/L 的过氧化氢作用内皮细胞24 h,采用电镜观察、MTT等方法测定各组细胞活力;RT-PCR检测核因子κB、IκB、肿瘤坏死因子α mRNA的表达, Western blot检测核因子κB、IκB蛋白的表达,ELISA检测上清中肿瘤坏死因子α蛋白的表达.结果 与空白对照组比较,过氧化氢能明显造成内皮细胞损伤(P<0.01) ,引起细胞活性降低.与过氧化氢损伤组比较,不同浓度组二苯乙烯苷均可以提高过氧化氢诱导损伤的人脐静脉内皮细胞活性,降低核因子κB、肿瘤坏死因子α mRNA及蛋白水平的表达,其中以1 μmol/L 二苯乙烯苷组的作用最明显,其差异有显著性(P<0.01),但对IκB的mRNA及蛋白水平差异均无显著性.结论 二苯乙烯苷对过氧化氢所致的人脐静脉内皮细胞损伤有保护作用,其机制可能与下调核因子κB、肿瘤坏死因子α的表达有关.     

金粉蕨素抑制氧化应激诱导的血管内皮细胞凋亡

研究金粉蕨素对氧化应激诱导的血管内皮细胞凋亡的影响及可能机制。用过氧化氢损伤人脐静脉内皮细胞株ECV304,制备内皮细胞凋亡模型。应用四甲基偶氮唑盐还原法观察细胞活性;流式细胞术和Tunel法检测细胞凋亡率;用Western blot检测细胞天冬氨酸凋亡蛋白酶3活性。结果发现,金粉蕨素(0.3、1和3 μmol/L)呈浓度依赖性地增加内皮细胞活性,显著降低细胞凋亡率(15.5％±1.2％、12,6％±0.9％、8.2％±0.8％比22.7％±3.9％,P<0.05);同时金粉蕨素(3 μmol/L)抑制过氧化氢诱导天冬氨酸凋亡蚤白酶3的活化,与阳性对照药金雀异黄酮作用强度相似。结果提示,金粉蕨素拮抗氧化应激诱导的血管内皮细胞凋亡可能与抑制天冬氨酸凋亡蛋白酶3活化有关。     

ATP对人脐静脉内皮细胞增殖的抑制作用及其可能机制

目的 观察胞外核苷酸ATP对人脐静脉内皮细胞增殖活性及其生物学功能的影响,并初步探讨其可能机制.方法 通过CCK-8细胞增殖试验检测不同浓度的ATP(0、 1、5、10、50和100 μmol/L)持续干预脐静脉内皮细胞 3天及ATP(50 μmol/L)不同时间段干预(1～6天)对脐静脉内皮细胞细胞增殖的影响;通过流式细胞术检测不同浓度的三磷酸腺苷诱导脐静脉内皮细胞凋亡情况及对其细胞生长周期的影响;通过RT-PCR对脐静脉内皮细胞表达的P2受体亚型进行检测,检测不同浓度的ATP(0、5、10、50和100 μmol/L)对脐静脉内皮细胞表达P2Y2、P2Y11,细胞周期素cyclinB1、cyclinD1及细胞间粘附分子1、血管细胞粘附分子1和内皮型一氧化氮合酶的影响.结果 与对照组比较,三磷酸腺苷在高浓度(50和100 μmol/L)持续作用于脐静脉内皮细胞 3天后显著抑制生长(P<0.01),终浓度50 μmol/L的ATP呈时间依赖性抑制脐静脉内皮细胞生长.不同浓度的ATP对脐静脉内皮细胞凋亡均无明显影响,但在高浓度时可显著增加S期的细胞比例和减少G2/M期的细胞比例从而将细胞周期阻滞在S期;静止状态下,脐静脉内皮细胞表达P2X-4,5和P2Y-2,4,11,13,14;三磷酸腺苷各浓度组均能明显上调脐静脉内皮细胞细胞间粘附分子1和血管细胞粘附分子1的表达,仅在高浓度时上调P2Y2,11、eNOS的表达和下调cyclinB1表达,而对表达cyclinD1的影响不明显.结论 胞外核苷酸三磷酸腺苷在高浓度(50和100 μmol/L)时可能通过受体P2Y2和P2Y11下调cyclinB1表达,使细胞周期从S期向G2/M期的转变受阻,从而抑制脐静脉内皮细胞生长,并且促进脐静脉内皮细胞表达动脉粥样硬化相关因子.     

去天冬氨酸血管紧张素-1对人脐静脉内皮细胞的保护作用

目的观察天冬氨酸血管紧张素-1(des-aspartate-angiotensin1,DAA-1)对过氧化氢致人脐静脉内皮细胞损伤的保护作用。方法实验分为正常对照组,过氧化氢模型组,过氧化氢加DAA-1组(低剂量、中剂量、高剂量组)。倒置显微镜下观察细胞形态、密度。噻唑蓝(MTT)法检测细胞活力,比色法测定细胞培养液中超氧化物歧化酶,活性、丙二醛及乳酸脱氢酶浓度。免疫细胞化学方法测定组织纤维蛋白溶酶原激活物,Ⅰ型纤溶酶原激活物抑制因子表达量。逆转录酶-聚合酶链反应(RT-PCR)方法测定细胞内皮素1和血栓调节蛋白mRNA的表达。结果DAA-1能明显抑制过氧化氢所致的细胞活力的降低[0.443±0.024vs.0.317±0.024,P0.01],减少细胞内乳酸脱氢酶释放[(102.35±9.87)U/Lvs.(242.78±16.10)U/L,P0.01],提高超氧化物歧化酶活力[(19.10±2.33)U/mLvs.(8.16±3.48)U/mL,P0.01],并呈剂量依赖性作用;能明显减少内皮细胞在氧化过程中丙二醛的生成[(1.35±0.19)U/mLvs.(2.33±0.48)U/mL,P0.01],增加组织纤维蛋白溶酶原激活物蛋白表达,减少Ⅰ型纤溶酶原激活物抑制因子蛋白表达;并能明显抑制内皮素mRNA的表达和提高血栓调节蛋白mRNA的表达。结论DAA-1对过氧化氢所致人脐静脉内皮细胞损伤具有明显的保护作用。     

阿托伐他汀通过调节Bcl-2/Bax蛋白表达抑制高糖诱导的人脐静脉内皮细胞凋亡

目的研究阿托伐他汀对高浓度葡萄糖诱导的人脐静脉内皮细胞凋亡的影响以及其分子机制。方法将培养的人脐静脉内皮细胞与不同浓度的葡萄糖(5.6 mmol/L、17.6 mmol/L、33.3 mmol/L)及阿托伐他汀(0.1μmol/L、1μmol/L、10μmol/L)作用24 h后用吖啶橙/溴化已啶荧光染色观察凋亡细胞形态,四甲基偶氮唑蓝比色法测定人脐静脉内皮细胞增殖率,流式细胞仪和W estern Blotting分别检测细胞早期凋亡率及Bcl-2/Bax蛋白表达。结果随着葡萄糖浓度的增加,人脐静脉内皮细胞增殖率逐渐降低(P0.05),细胞早期凋亡率逐渐升高(P0.05)。人脐静脉内皮细胞Bcl-2蛋白表达逐渐减弱,Bax蛋白表达逐渐增强。用不同浓度的阿托伐他汀干预后,人脐静脉内皮细胞的增殖率逐渐升高(P0.05),而凋亡率逐渐降低(P0.05);人脐静脉内皮细胞Bcl-2蛋白表达逐渐增强,Bax蛋白表达逐渐减弱。其中,与高糖组比较,10μmol/L阿托伐他汀干预组能提高Bcl-2蛋白表达(P0.05),抑制Bax蛋白表达(P0.05)。结论阿托伐他汀可能通过调节Bcl-2/Bax蛋白表达抑制高浓度葡萄糖诱导的人脐静脉内皮细胞凋亡。     

槲皮素对血管内皮细胞损伤的保护作用

目的 :研究槲皮素对血管内皮细胞损伤的保护作用及机制。　　方法 :实验分对照组、模型组和槲皮素组 ,用过氧化氢诱导血管内皮细胞损伤 ,四甲基偶氮唑蓝比色法检测细胞存活数量 ,放射免疫法测定细胞培养液中的内皮素及前列环素含量 ,用荧光法检测细胞内脂质过氧化产物丙二醛以评价脂质过氧化程度。　　结果 :槲皮素 5、2 0、40、80和 10 0 μmol/ L 促进培养的正常血管内皮细胞增殖 ,增加前列环素生成 ,减少内皮素基础释放量 ;75 μmol/ L过氧化氢可损伤培养的血管内皮细胞 ;槲皮素 5、2 0和 80 μmol/ L 可抑制过氧化氢损伤的血管内皮细胞释放乳酸脱氢酶、内皮素及促进损伤的内皮细胞释放前列环素。　　结论 :槲皮素具有保护血管内皮细胞损伤的作用 ,其机制可能与其抗脂质过氧化作用有关。     

7-二氟亚甲基-5,4′-二甲氧基染料木黄酮通过下调Caspase-3的表达拮抗H2O2诱导的血管内皮细胞凋亡

目的研究7-二氟亚甲基-5,4'-二甲氧基染料木黄酮对H_2O_2诱导血管内皮细胞凋亡的影响,并初步探讨其作用机制。方法用1 mmol/L H_2O_2诱导人脐静脉内皮细胞建立氧化应激损伤模型。实验分为空白对照组、H_2O_2损伤组、溶媒对照组、先导化合物组(100μmol/L染料木黄酮)、不同浓度(0.1、0.3、1、3、10μmol/L)7-二氟亚甲基-5,4'-二甲氧基染料木黄酮组。DCFH-DA激活荧光流式细胞术测定活性氧的生成,吖啶橙染色荧光显微镜观察细胞凋亡形态,PI染色流式细胞术检测细胞凋亡率,Western blot测定Caspase-3的表达。结果 1 mmol/L H_2O_2孵育血管内皮细胞24 h,活性氧的生成显著增加,吖啶橙染色荧光显微镜下细胞呈现明显的凋亡形态学改变,细胞凋亡率升高,Caspase-3的表达上调。用7-二氟亚甲基-5,4'-二甲氧基染料木黄酮预处理血管内皮细胞后可见活性氧的生成减少,细胞凋亡率降低,Caspase-3的表达下调。结论 7-二氟亚甲基-5,4'-二甲氧基染料木黄酮对H_2O_2诱导血管内皮细胞凋亡有明显的抑制作用,其作用机制可能是通过降低活性氧的生成,下调Caspase-3的表达,从而拮抗H_2O_2诱导的血管内皮细胞凋亡。     

阿魏酸抑制培养人内皮细胞粘附分子的表达

观察阿魏酸对活化的人脐静脉内皮细胞表达粘附分子的影响,以探讨其抗动脉粥样硬化的部分分子机制.用10 mg/L脂多糖刺激培养的人脐静脉内皮细胞4 h,诱导其表达E-选择素;用300 μmol/L过氧化氢刺激内皮细胞2 h,诱导其表达P-选择素.部分细胞在刺激前30min用0.21、0.41或0.62mmol/L阿魏酸预处理.用流式细胞术检测内皮细胞粘附分子表达水平,用逆转录聚合酶链反应检测内皮细胞E-选择素mRNA表达水平.结果发现,阿魏酸抑制内皮细胞E-选择素及P-选择素表达,同时抑制E-选择素mRNA表达.提示阿魏酸抗动脉粥样硬化作用可能与其抑制内皮细胞粘附分子表达有关.     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.     

Changes in connexin43, the gap junction protein of astrocytes, during development of the rat pineal gland

Abstract: The abundance of gap junctions between rat pineal astrocytes formed by connexin43 (Cx43) was studied during development. Levels and distribution of Cx43 were measured by immunoblotting and indirect immunofluorescence, respectively. The amount of Cx43 in cells located within the gland was low until about the 7th postnatal day and increased to adult values between the 14th and 21st days postpartum. Although astrocytes, recognized by their vimentin immunoreactivity, were scarce before birth, they were abundant by the 7th postnatal day suggesting that the low levels of Cx43 found at this age corresponded to a low expression of this protein. Localization of the immunoreactivity to Cx43 and vimentin showed a close correlation, indicating that mature or immature pineal astrocytes form gap junctions made of Cx43. Since Cx43 levels attained their adult values at about the time the innervation and the functional state of the gland reached maturity (2–3 weeks after birth), it is proposed that astrocyte gap junctions are involved in the function of the adult rat pineal gland.     

Conservative management of perforated duodenal diverticulum： A case report and review of the literature

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.     

Presence of immunoreactive growth hormone and prolactin in the ovine pineal gland

Abstract: The use of antisera raised against bovine growth hormone (GH) and ovine prolactin (PRL) enabled the detection of related immunoreactive (ir) sequences of proteins in ovine pineal tissue. The isolation of PRL-like ir-material was accomplished using a 0.25 M ammonium sulphate (pH 5.5) extraction followed by ethanol precipitation, whereas the resulting 2.0 M ammonium sulphate (pH 7.0) precipitate contained a GH-like immunoreactivity. Gel chromatography of the GH-like immunoreactivity (Sephadex G-100) indicated the presence of several GH-like fragments ranging in the M_r range of 7,000 to 55,000. Analyses of the PRL-like ir-material found in pineal tissue on HPLC using a TSK 545-DEAE column led to the resolution into a single peak of immunoreactivity. A single peak of activity was also observed following chromatofocusing and hydrophobic interaction chromatography of the ir-peak from the TSK 545-DEAE column. The PRL-like ir-material inhibited the binding of [¹²⁵I]ovine PRL-S14 to anti-ovine PRL antibodies without showing an affinity for binding to anti-rat PRL or anti-bovine GH antibodies. Scatchard analysis of the binding of pineal PRL-like ir-material and pituitary ovine PRL-S14 to liver membranes from day-20 pregnant rats revealed similar affinity constants (K_a of 4.7 ± 0.2 × 10⁹ M^-1). In addition, the replication of Nb 2 Node rat lymphoma cells was stimulated by pineal PRL-like ir-material, an effect known to be specific for lactogenic hormones. The pineal PRL-like immunoreactivity appeared on sodium dodecyl sulfate polyacrylamide gels as a single major band of M_r 24,000. The functional status of PRL-and GH-like ir-material in the ovine pineal remains to be determined, but evidence is presented that the overall protein synthesis rate of the rat pineal responded to circulating concentrations of PRL.     

Microbiology of human immunodeficiency virus anorectal disease

PURPOSE: Individuals who are seropositive for the human immunodeficiency virus are at high risk for opportunistic infection and anorectal disorders. Little prospective information is available regarding anorectal pathogens in these patients. METHODS: One hundred sixty-three HIV-seropositive patients presented to the colorectal clinic between 1989 and 1992. Forty-seven (29 percent) patients were thought to have an infectious process and were prospectively studied using a standardized multiculture protocol. RESULTS: Mean age was 33 (range, 19–59) years. All were male; high-risk behavior accounted for 87 percent of HIV transmissions. Presenting complaints included anorectal pain (79 percent), pus per anum (28 percent), and blood per anum (26 percent). Examination revealed perianal tenderness (60 percent), condyloma (38 percent), perianal ulcers (38 percent), and anal fissures (34 percent). Sixty-six sets of cultures were performed; 28 patients had one set, 15 had two sets, and 4 had three sets. Thirty-two of these 47 patients (68 percent) had positive cultures including herpes (50 percent), cytomegalovirus (25 percent),Neisseria gonorrhoeae (16 percent), chlamydia (16 percent), acidfast bacilli (2 percent), and others (9 percent). Six of 32 patients with positive cultures had more than one organism cultured. Sixteen (50 percent) patients with positive cultures were treated medically, 8 (25 percent) were treated surgically and 8 (25 percent) were treated with both modalities. Sixty-one procedures were performed on 17 patients for condylomata. Eighteen patients had 20 procedures for abscesses, 50 percent of whom had positive cultures for other than common bowel flora; all improved. Fourteen patients underwent 33 procedures for perianal fistulas.Mycobacterium fortuitum was cultured from one patient who required 13 procedures for abscesses and fistulas. Forty-five (96 percent) patients were followed for an average of 12.5 months ±2.9 SEM (range, 1–94 months). Symptoms were improved or resolved in 22 of 32 (69 percent) patients with positive cultures and in 11 of 13 (84 percent) with negative cultures. CONCLUSIONS: Specific pathogens may often be identified in human immunodeficiency virus-seropositive patients with anorectal disorders if aggressively sought. Although patients without specific pathogens identified may be expected to improve with planned empiric treatment, positive identification allows more directed therapy.