二苯乙烯苷通过核因子κB信号通路抑制过氧化氢诱导的人脐静脉内皮细胞凋亡

目的 研究二苯乙烯苷对过氧化氢诱导人脐静脉内皮细胞凋亡的保护作用,探讨二苯乙烯苷是否通过核因子κB信号通路调节凋亡相关基因的表达来抑制细胞凋亡.方法 体外培养人脐静脉内皮细胞,实验分为对照组、过氧化氢组和二苯乙烯苷组,采用显微镜观察细胞形态,MTT法检测细胞增殖率,流式细胞术检测细胞凋亡率,Western blot检测核因子κB p65、IκB、bcl-2蛋白的表达.结果 过氧化氢能显著抑制内皮细胞增殖,增加细胞凋亡率;并增加核因子κB p65蛋白的表达,降低bcl-2和IκB蛋白的表达.二苯乙烯苷预处理后显著增加氧化损伤内皮细胞的增殖率,并降低细胞凋亡率;与过氧化氢组相比,二苯乙烯苷组核因子κB p65蛋白的表达显著降低,bcl-2和IκB蛋白的表达显著升高(P<0.01).结论 二苯乙烯苷对过氧化氢诱导人脐静脉内皮细胞凋亡具有保护作用,其机制可能与其抑制核因子κB/ IκB信号通路并上调bcl-2蛋白的表达有关.     

α-硫辛酸抑制糖基化终末产物诱导血管内皮细胞凋亡的研究

目的研究α-硫辛(ALA)对晚期糖基化终末产物(AGEs)诱导血管内皮细胞凋亡的抑制作用及机制。方法体外培养人脐静脉内皮细胞,加不同培养液孵育60 min,以人血清白蛋白(HSA)培养液作为对照组,以AGEs-HSA 200 mg/L培养液体外培养60 min为AGEs-HSA组,以ALA 200 μg/ml加入200 mg/L AGEs为ALA组,采用Hoechst 33258染色检测细胞凋亡,Western blot法检测NF-κB p65核蛋白表达,ELISA法测定天冬氨酸蛋白酶3(caspase-3)活性。结果 AGEs以浓度依赖方式促进内皮细胞凋亡。与对照组比较,AGEs-HSA组细胞NF-κB p65蛋白表达量明显减低,caspase-3活性明显增高(P0.05);与AGEs HSA组比较,ALA组内皮细胞凋亡明显减少,NF-κB p65蛋白表达量明显增加,caspase-3活性明显降低(P0.05)。结论 ALA可能通过增加NF-κB表达,抑制caspase-3激活的AGEs诱导内皮细胞凋亡。     

二甲双胍对人脐静脉内皮细胞缺氧/复氧损伤的保护作用

目的　探讨二甲双胍对人脐静脉内皮细胞缺氧/复氧损伤的影响及其可能机制。方法　体外培养人脐静脉内皮细胞,建立缺氧/复氧模型,随机分为5组：正常对照组、缺氧/复氧组、缺氧/复氧+不同浓度（0.1、0.5、1.0　mmol/L）二甲双胍干预组。流式细胞术检测各组细胞的凋亡率,实时定量聚合酶链反应检测各组核因子κB/P65　mRNA的表达,酶联免疫吸附法检测各组上清液中细胞间黏附分子1和肿瘤坏死因子α的浓度。结果　与对照组相比,缺氧/复氧组细胞凋亡增加（P<0.05）,核因子κB/P65　mRNA增加,同时细胞间黏附分子1和肿瘤坏死因子α的浓度均升高（P<0.05）;与缺氧/复氧组比较,二甲双胍预处理能减少缺氧/复氧所致人脐静脉细胞凋亡（P<0.05）,减少核因子κB/P65的mRNA的表达,同时细胞间黏附分子1和肿瘤坏死因子α的浓度均降低（P<0.05）,其中0.5　mmol/L浓度组保护作用最佳。结论　二甲双胍对缺氧/复氧损伤引起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/P65表达及抑制了细胞间黏附分子1和肿瘤坏死因子α的释放有关。     

NF-κB在TNF-α致人脐静脉内皮细胞凋亡中的作用

目的研究核转录因子-κB（nuc lear factor-κB,NF-κB）在TNF-α诱导培养的人脐静脉内皮细胞凋亡过程中的作用。方法体外培养人脐静脉内皮细胞,并用10 ng/m l的TNF-α进行诱导,不同时间段观察NF-κB活性、NF-κB抑制物IκBα表达以及细胞凋亡的情况,EMSA测定NF-κB活性,W estern-b lot检测IκBα的表达情况;Tunel法检测细胞凋亡;并用NF-κB的抑制剂PDTC预处理细胞后来观察TNF-α诱导细胞凋亡的情况。结果TNF-α以时间依赖性诱导人脐静脉内皮细胞凋亡,NF-κB的活性在处理后10 m in开始增强,2 h后恢复正常,IκBα的表达在10m in开始下降,2 h恢复正常;PDTC能抑制TNF-α诱导的凋亡。结论TNF-α在诱导体外培养的人脐静脉内皮细胞时,IκBα降解,NF-κB激活,从而引起细胞的凋亡。     

重组人红细胞生成素通过上调核因子-κB p65减少同型半胱氨酸诱导的培养内皮细胞凋亡

目的 探讨红细胞生成素(erythropoietin,EPO)对同型半胱氨酸(homocysteine,Hcy)诱导的血管内皮细胞凋亡的影响以及核因子-κB(nuclear factor-κB,NF-κB)p65的作用.方法 培养人脐静脉内皮细胞株(human umbilical vein endothelial cell,HUVEC)分为正常对照组、Hcy处理组、EPO预处理组和单纯EPO组.四甲基偶氮唑蓝法检测细胞存活率,流式细胞术检测细胞凋亡率,蛋白质印迹法检测NF-κB p65表达.结果 正常对照组、Hcy处理组、EPO预处理组和单纯EPO组(n均=3)细胞凋亡率分别为(2.23±0.4)％、(12.8±1.2)％、(3.2±0.5)％和(2.18±0.6)％(F=1 105.630,P =0.000).Hcy处理组细胞凋亡率较正常对照组显著性增高(P=0.000);单纯EPO组(P=0.616)与正常对照组无显著性差异;EPO预处理组(P =0.000)和单纯EPO组(P =0.000)均较Hcy处理组显著性降低.蛋白质印迹分析显示,正常对照组基本不表达NF-κB p65.Hcy处理组、单纯EPO组和EPO预处理组(n均=3)分别为66.1±7.3、1 046.1 ±71.3和1 362.4±25.3,三组间存在显著性差异(F=1 310.954,P=0.000).EPO预处理组(P=0.000)和单纯EPO组(P=0.000) NF-κB p65表达均显著性高于Hcy组;EPO预处理组显著性高于单纯EPO组(P=0.007).结论 EPO可能通过上调NF-κB p65表达减少Hcy诱导的内皮细胞凋亡.     

表没食子儿茶素没食子酸酯对高糖环境下内皮细胞氧化应激的影响

目的研究不同剂型表没食子儿茶素没食子酸酯（EGCG）对高糖诱导人脐静脉内皮细胞（HUVEC）氧化应激损伤所引起凋亡的抑制作用及人核因子-κB P65（NF-κB P65）表达的影响。方法从新鲜脐带中分离培养HUVEC。用高糖诱导HUVEC表达NF-κB P65,实验组加入不同浓度的EGCG（12．5、25、50、100、200μmol／L）进行干预,PCR检测NF-κB P65mRNA的表达,AV-PI法检测凋亡细胞。结果高糖可诱导HUVEC凋亡,NF-κB P65表达增高;EGCG可抑制NF-κB P65的表达,降低凋亡指数,具有一定的时效关系、剂量关系。结论EGCG可在一定程度上抑制高糖诱导的氧化应激损伤所致的细胞凋亡。EGCG可能是通过抑制高糖所致的NF-κB增高,从而调控HUVEC细胞凋亡过程,发挥对HUVEC的保护作用。     

替米沙坦对同型半胱氨酸诱导的人脐静脉内皮细胞血管细胞黏附分子1、核因子κB表达及细胞黏附的影响

目的观察替米沙坦对同型半胱氨酸诱导体外培养的人脐静脉内皮细胞血管细胞黏附分子1(VCAM-1)、核因子κB(NF-κB)表达及与单核细胞黏附的影响。方法胶原酶消化法获取人脐静脉内皮细胞;RT-PCR检测VCAM-1 mRMA的表达;Western blot检测VCAM-1、NF-κB蛋白的表达;ROSE BENGAL染色法检测单核细胞-血管内皮细胞黏附功能。结果与空白对照组相比,同型半胱氨酸增强了人脐静脉内皮细胞VCAM-1 mRMA、VCAM-1蛋白、NF-κB p65蛋白的表达水平及与单核细胞黏附能力。替米沙坦(1000 nmol/L组)明显降低了同型半胱氨酸诱导的人脐静脉内皮细胞VCAM-1 mRMA、VCAM-1蛋白、NF-κB p65蛋白及与单核细胞的黏附水平(P<0.01)。与同型半胱氨酸组比,PDTC(NF-κB抑制剂)组NF-κB p65蛋白、VCAM-1 mRMA、VCAM-1蛋白表达水平均明显降低,内皮细胞与单核细胞的黏附水平也明显降低(P<0.01)。结论替米沙坦抑制了VCAM-1 mRMA和蛋白的表达及内皮与单核细胞的黏附水平,其机制可能是通过抑制NF-κB而抑制炎症反应及内皮损伤。     

山莨菪碱下行调节培养的内皮细胞表达纤溶酶原激活物抑制剂1

为了探讨山莨菪碱对正常及内毒素脂多糖刺激过的内皮细胞纤溶酶原激活物抑制剂 1表达的作用及机制。本文采用酶消化法培养人脐静脉内皮细胞 ;用酶联免疫吸附试验 (ELISA)方法检测人脐静脉内皮细胞条件培养基纤溶酶原激活物抑制剂 1和组织型纤溶酶原激活物蛋白量 ;用Northern印迹方法检测人脐静脉内皮细胞纤溶酶原激活物抑制剂 1的mRNA表达 ;用电泳迁移检测法对人脐静脉内皮细胞的核因子κB核内转移情况进行研究。结果发现 ,脂多糖能使人脐静脉内皮细胞纤溶酶原激活物抑制剂 1蛋白及mRNA表达显著增强 ,但加入山莨菪碱后 ,脂多糖的这种作用明显减弱。而且 ,山莨菪碱还能抑制人脐静脉内皮细胞纤溶酶原激活物抑制剂 1基础水平的表达。经脂多糖刺激的人脐静脉内皮细胞核提取物与核因子κB探针结合明显增强 ,而山莨菪碱则能阻止脂多糖致核因子κB的核内转移现象。提示山莨菪碱不仅下行调节脂多糖所致内皮细胞纤溶酶原激活物抑制剂 1的蛋白分泌和mRNA表达 ,而且下行调节其纤溶酶原激活物抑制剂 1基础水平表达 ,这种调节可能通过核因子κB途径而发挥作用     

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.     

金雀异黄素抑制人血管平滑肌细胞中核因子κB的激活

目的 研究金雀异黄素对氧化型低密度脂蛋白诱导的人血管平滑肌细胞中核因子κB激活的影响,并对其作用机制进行初步探讨.方法 以体外培养的人脐静脉平滑肌细胞为对象,用50 mg/L的氧化型低密度脂蛋白作用细胞2 h,并加入不同浓度金雀异黄素(10,30,90 mol/L)对其进行干预,免疫细胞化学方法检测各组血管平滑肌细胞中核因子κB亚单位p65核移位阳性细胞数,Western blot法检测细胞内κB抑制蛋白-α含量变化,硝酸还原酶法测定各组细胞培养液中一氧化氮生成量.结果 人脐静脉平滑肌细胞经氧化型低密度脂蛋白刺激2 h后,其核移位阳性细胞数为76.67±3.21,与空白组1.33±0.58相比明显增加(P<0.01),再与不同浓度金雀异黄素共同孵育2 h后,核移位阳性细胞数分别为28.33±2.52,19.67±1.53和15.67±2.89,与单纯给予氧化型低密度脂蛋白刺激相比明显减少(P<0.01),且随着浓度升高有递减的趋势;30,90 μmol/L金雀异黄素能明显增加细胞内κB抑制蛋白-α的含量;各组细胞培养液内的一氧化氮生成量差异无显著性.结论 金雀异黄素能抑制氧化型低密度脂蛋白诱导的血管平滑肌细胞中核因子κB的活化;其作用机制可能涉及增加细胞内κB抑制蛋白含量,未发现与一氧化氮有关.     

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.