阿司匹林抗高糖诱导的内皮细胞衰老过程中对DDAH-ADMA系统及Caveolin-1蛋白的影响

目的观察阿司匹对高糖诱导的内皮细胞衰老模型二甲基精氨酸二甲胺水解酶(DDAH)-非对称性二甲基精氨酸(ADMA)系统和Caveolin-1蛋白表达的影响,探讨阿司匹林抗高糖诱导内皮细胞衰老的机制。方法人脐静脉内皮细胞(HUVEC)分别培养于正常糖浓度培养液(5.5 mmol/L)、高糖培养液(33 mmol/L)、高糖+阿司匹林(0.01~1 mmol/L)培养液以及含L-NAME(300μmol/L)培养液,48 h后采用β-半乳糖苷酶(β-gal)染色鉴定衰老细胞,流式细胞仪检测细胞内活性氧(ROS)水平,Western blot分析Caveolin-1蛋白表达,液质联用仪检测细胞上清液中ADMA的含量并计算DDAH的活性。结果高糖作用内皮细胞48 h后,细胞β-gal染色阳性细胞数明显增多,ROS、ADMA水平以及Caveolin-1蛋白表达升高,DDAH活性降低。0.01~1 mmol/L阿司匹林剂量依赖性地降低β-gal染色阳性细胞数、ROS和ADMA水平以及Caveolin-1蛋白表达,同时升高细胞DDAH活性(P均0.05)。L-NAME(NOS的抑制剂)能完全抑制阿司匹林的上述作用(P0.05)。结论高糖环境下阿司匹林(0.01~1mmol/L)能抑制Caveolin-1表达,改善DDAH-ADMA系统的活性而进一步发挥抗氧化损伤、抗细胞衰老的作用。     

瓜蒌皮提取物对人脐带静脉内皮细胞损伤的保护作用

目的研究瓜蒌皮提取物（EPT）对氧化低密度脂蛋白（OX-LDL）诱导的人脐带静脉内皮细胞（HUVECs）损伤的保护作用。方法在培养的人脐带静脉内皮细胞中加入OX-LDL（100mg／L）诱导内皮细胞损伤。检测细胞培养液中非对称性二甲基精氨酸（ADMA）、丙二醛（MDA）、乳酸脱氢酶（LDH）、一氧化氮（NO）、二甲基精氨酸二甲胺水解酶（DDAH）和肿瘤坏死因子-α（TNF-α）的含量。结果体外给予OX-LDL（100mg／L）显著诱导内皮细胞损伤,提高培养液中ADMA、MDA、LDH、和TNF-α水平,降低NO和DDAH水平。两种洗脱（水和70％乙醇洗脱）瓜蒌皮提取物均能显著抑制OX—LDL所致的ADMA、MDA、LDH和TNF-α浓度升高和NO、DDAH降低。结论瓜蒌皮提取物对OX—LDL诱导的人脐带静脉血管内皮细胞损伤有保护作用,其保护作用与降低ADMA和TNF-α浓度有关。     

高糖诱导人脐静脉内皮细胞衰老

使用正常糖浓度培养液和高糖培养液处理人脐静脉血管内皮细胞48h后,观察细胞形态,β－半乳糖苷酶染色鉴定衰老细胞,PCR—ELISA法检测端粒酶的活性,流式细胞仪检测细胞周期和细胞内活性氧水平。结果发现,与正常糖浓度处理的内皮细胞比较,不同浓度高糖培养液作用48h后的内皮细胞β－半乳糖苷酶染色阳性细胞明显增多,细胞周期多停滞于G0／G1期,S期显著减少,端粒酶活性明显下降,细胞内活性氧水平明显升高（P〈0．05或P〈0．01）。认为高糖环境可加速内皮细胞衰老进程,其作用机制可能与氧化应激有关。     

阿司匹林抗高糖诱导的内皮细胞衰老的作用

目的 探讨阿司匹林是否具有抗高糖诱导的内皮细胞衰老的作用及其机制。方法 人脐静脉内皮细胞（HUVEC）分别于正常糖浓度培养液 （5.5 mmol/L）、高糖培养液和高糖（33 mmol/L）＋阿司匹林（0.01、0.1、1及3 mmol/L）培养液中培养48 h,观察细胞形态、采用β-半乳糖苷酶染色鉴定衰老细胞,PCR-ELISA检测端粒酶活性,流式细胞仪检测细胞周期和细胞内活性氧水平。结果 高糖培养液作用HUVEC 48 h后,细胞呈现衰老状态,β-半乳糖苷酶染色阳性细胞数明显增加,端粒酶活性明显减低,细胞周期停滞于G0/G1期,S期显著减少,细胞内活性氧水平显著增加。0.01、0.1和1 mmol/L阿司匹林作用后细胞形态改善,β-半乳糖苷酶染色阳性细胞数显著减少,端粒酶活性增强,S期细胞显著增加,细胞内活性氧水平降低（P<0.05）。而3 mmol/L阿司匹林作用后与高糖组相比差异无显著性。结论 高糖环境下阿司匹林（0.01、0.1和1 mmol/L）具有抗内皮细胞衰老的作用,其作用机制可能与氧化应激有关。     

非对称二甲基精氨酸在氧化低密度脂蛋白诱导基质金属蛋白酶2蛋白表达中的作用及机制

目的初步探讨非对称二甲基精氨酸(ADMA)在氧化低密度脂蛋白(ox-LDL)诱导基质金属蛋白酶2(MMP-2)蛋白表达中的作用及可能机制。方法观察ox-LDL对内皮细胞的损伤作用和MMPs抑制剂多西环素对ox-LDL诱导的内皮细胞MMP-2蛋白表达及ADMA水平的影响;观察ADMA对内皮细胞MMP-2蛋白表达及内皮细胞活性氧(ROS)水平的影响。结果(1)ox-LDL降低内皮细胞生存率呈浓度和时间依赖性;(2)多西环素能明显抑制ox-L,DL诱导的细胞生存率的降低,并显著降低ox-LDL(50 mg/L)诱导的ADMA水平与MMP-2蛋白表达的升高(多西环素5μg/ml时P<0.05,多西环素10,20μg/ml时P<0.01);(3)ADMA降低内皮细胞生存率呈浓度依赖性(P<0.01),并可升高内皮细胞ROS与MMP-2蛋白表达水平(ADMA 3μmol/L时P<0.05,ADMA 10,30μmol/L时P<0.01)。L精氨酸和细胞内抗氧化剂(PDTC)均能拮抗上述作用(P<0.01)。、结论ox-LDL诱导内皮细胞MMP-2蛋白表达水平升高可能涉及ADMA途径;多西环素对MMP-2蛋白表达的抑制作用可能与降低ADMA水平有关;ADMA可能通过诱导氧化应激增加MMP-2蛋白表达。     

六味地黄丸在胰岛素抵抗的人脐静脉内皮细胞氧化应激损伤中的作用

目的研究六味地黄丸(LWDHP)含药学清在胰岛素抵抗(IR)的人脐静脉内皮细胞(HUVEC)氧化应激(OS)损伤中的作用。方法将培养的HUVEC分组,采用软脂酸(PA)诱导细胞损伤形成IR状态,然后采用DCFH-DA荧光探针法检测内皮细胞裂解液中活性氧(ROS)含量,酶联免疫吸附实验(ELISA)检测细胞培养基中非(不)对称二甲基精氨酸(ADMA)浓度,RT-PCR及Western印迹检测细胞内二甲基精氨酸二甲胺水解酶(DDAH)2 mRNA和蛋白的表达。结果模型组的ADMA浓度和ROS水平明显增高,与对照组比较差异有统计学意义(P0. 01)。5%和10%LWDHP含药血清能显著降低ADMA浓度和ROS含量,与模型组比较差异有统计学意义(P0. 01)。同时,PA组细胞内DDAH2 mRNA和蛋白的表达量显著降低(P0. 01),5%LWDHP含药血清组细胞内DDAH2 mRNA表达量明显升高(P0. 01)。结论 LWDHP可以通过抗氧化保护作用,一定程度上调节ROS-DDAH2-ADMA的表达,抑制OS,改善IR。     

内皮功能异常的新机制——二甲基精氨酸二甲基氨基水解酶调节异常

内皮依赖性血管扩张功能发生异常的机制可能是多因素的,不对称二甲基精氨酸(ADMA)水平的升高是其可能因素之一。ADMA是一氧化氮合成酶(NOS)的内源性竞争性抑制物,包括人内皮细胞在内的多种细胞可以产生ADMA,后者经尿液排出或由二甲基精氨酸二甲基氨基水解酶(DDAH)代谢。DDAH将ADMA水解为L-瓜氨酸和二甲胺。在高胆固醇血症或动脉粥样硬化的患者中血浆ADMA水平升高。该文推测AD-     

沙格列汀对过氧化氢诱导损伤的血管内皮细胞二甲基精氨酸二甲胺水解酶/非对称性二甲基精氨酸/内源性一氧化氮合酶通路影响的研究

目的观察二肽基肽酶-4(DPP-4)抑制剂沙格列汀对过氧化氢(H2O2)诱导损伤的血管内皮细胞二甲基精氨酸二甲胺水解酶/非对称性二甲基精氨酸/内源性一氧化氮合酶(DDAH/ADMA/eNOS)通路的影响。方法以培养人脐静脉内皮细胞株(HUVEC)作为靶细胞,在内皮细胞培养基中加入100μmol/L的H2O2制备细胞损伤模型,以20μmol/L沙格列汀进行干预,观察24~72h,检测细胞上清一氧化氮(NO)含量、ADMA浓度,检测细胞中NOS活性、DDAH活性及DDAH蛋白表达量。结果H2O2作用HUVEC后,细胞上清中NO含量降低,而ADMA浓度增加(P0.05)。细胞中NOS活性、DDAH活性、DDAH-Ⅱ蛋白表达量降低(P0.05);而加入沙格列汀,细胞上清中NO含量升高,ADMA浓度降低(P0.05)。细胞中NOS活性、DDAH活性、DDAH-Ⅱ蛋白表达量升高(P0.05)。结论沙格列汀通过对DDAH/ADMA/eNOS通路的调节作用改善H2O2诱导的内皮细胞NO生成减少。     

氧化低密度脂蛋白对血管内皮细胞二甲精氨酸-二甲赖氨酸水解酶系统的影响及卡托普利的作用

目的:观察氧化低密度脂蛋白(ox-LDL)对培养的人脐静脉内皮细胞(HUVECs)二甲精氨酸-二甲赖氨酸水解酶(DDAH)活性及表达的影响,以探讨不对称二甲精氨酸(ADMA)代谢机制及卡托普利作用。方法:采用改良的Jaffe法培养原代HUVECs,取生长良好的3～6代HUVECs用于实验,分为①空白对照组:加DMEM培养液;②ox-LDL组:加入ox-LDL(100,150mg/L);③ox-LDL加卡托普利组:同时加入150mg/Lox-LDL及卡托普利100mg/L,共孵24h后,检测上清液中一氧化氮(NO)、内皮素(ET)、一氧化氮合酶(NOS)活性、ADMA含量、反应DDAH酶活性的L-胍氨酸(L-cit)浓度,采用Western blot测定细胞裂解液中DDAH的蛋白表达。结果:ox-LDL条件培养下,内皮细胞的代谢产物ADMA、ET的量均较空白对照组高,而NO的量及NOS的活性减少;L-cit浓度显著降低,且有浓度依赖性,而DDAH的表达无明显变化。卡托普利干预后,AD-MA、ET的量较ox-LDL组降低,NOS活性及NO增加,L-cit浓度明显升高。结论:ox-LDL诱导下,内皮损伤ADMA的增加与DDAH的活性减弱有关,而与DDAH的表达无关。卡托普利通过增加DDAH活性促进AD-MA代谢,使NOS活性增高,抑制ox-LDL对内皮功能的损伤。     

低浓度乙醇对血管内皮细胞损伤的保护作用

目的研究乙醇对氧化低密度脂蛋白(ox-LDL)诱导的人脐带静脉内皮细胞损伤的保护作用与内源性一氧化氮合酶抑制物的关系。方法在培养的人脐带静脉内皮细胞中加入ox-LD(L100μg/ml)诱导内皮细胞损伤。检测细胞培养液中非对称性二甲基精氨酸(ADMA)、丙二醛(MDA)、乳酸脱氢酶(LDH)、一氧化氮(NO)和肿瘤坏死因子-(αTNF-α)的含量。结果体外给予ox-LD(L100μg/ml)显著诱导内皮细胞损伤,增加培养液中ADMA、MDA、LDH和TNF-α水平,而降低NO水平。两个剂量乙醇(5或15μg/ml)均能显著抑制ox-LDL所致ADMA、MDA、LDH和TNF-α浓度升高和NO的降低。结论低剂量乙醇对ox-LDL诱导的人脐带静脉血管内皮细胞损伤有保护作用,其保护作用与降低ADMA和TNF-α浓度有关。     

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.     

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.     

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.     

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.