5-Aza-CdR对胃癌细胞系生长及Apaf-1基因异常甲基化的影响

目的:观察5-氮杂-2′-脱氧胞苷(5-aza-2′-deoxycitydine,5-Aza-CdR)对体外培养的胃癌SGC7901细胞和BGC823细胞增生、细胞周期和凋亡的影响及其对此两株细胞中Apaf-1基因的甲基化状态的影响.方法:不同浓度5-Aza-CdR处理体外培养的SGC7901细胞和BGC823细胞后,用MTT法检测处理24,48和72 h的细胞增殖活性;PI染色和流式细胞仪检测药物处理后72 h细胞周期分布和细胞凋亡率;MSP法检测用药前后细胞中Apaf-1基因的甲基化状态;RT-PCR法及Western blot法检测用药前后细胞中Apaf-1的mRNA及蛋白表达的变化.结果:1×10-7,5×10-7,1×10-6和5×10-6 mol/L5-Aza-CdR处理SGC7901和BGC823细胞24,48,72 h后,细胞增生受到抑制,有时间和剂量的依赖性.流式细胞仪分析表明,各药物浓度处理72 h后凋亡率增加明显:SGC7901细胞5×10-7,1×10-6和5×10-6 mol/L组分别为2.53%±1.19%,5.93%±0.86%,10.14%±1.51%,与对照组(0.12%±0.03%)相比差异显著(P＜0.05);BGC823细胞5×10-7,1×10-6和5×10-6 mol/L组分别为1.57%±0.26%,4.64%±1.05%,8.21%±1.46%,与对照组(0.57%±0.03%)相比差异显著(P＜0.05).在5-Aza-CdR处理前未检测到SGC7901细胞系及BGC823细胞系的Apaf-1基因的mRNA及蛋白表达,经过5-Aza-CdR处理后,Apaf-1基因在SGC7901细胞系及BGC823细胞系中甲基化状态得到了逆转,Apaf-1基因的mRNA及蛋白重新表达.结论:5-Aza-CdR对SGC7901细胞和BGC823细胞具有增生抑制作用;Apaf-1基因的表达情况与其甲基化状态的改变有关.     

5-氮杂-2'-脱氧胞苷对人胃癌SGC-7901细胞株生长及EDNRB基因启动子异常甲基化的影响

目的:探讨去甲基化药物5-氮杂-2'-脱氧胞苷(5-Aza-CdR)对人胃癌细胞系SGC-7901细胞株的生长及EDNRB基因启动子异常甲基化的影响.方法:使用1、2、5、10μmol/L5-Aza-CdR干预胃癌SGC-7901细胞,甲基化特异性PCR(MSP)和逆转录聚合酶链反应(RT-PCR)分别检测药物干预前后EDNRB基因的甲基化状态和EDNRB mRNA的表达,MTT法检测细胞增殖活性,流式细胞术分析细胞周期及细胞凋亡的改变.结果:未经5-Aza-CdR处理的SGC-7901细胞中EDNRB基因启动子区域CpG岛高甲基化,且EDNRB mRNA不表达,经1、2、5、10μmol/L5-Aza-CdR处理4d后,EDNRB基因启动子区域高甲基化状态得到逆转,细胞中EDNRB mRNA表达恢复.4种浓度5-Aza-CdR处理的SGC-7901细胞后,细胞增殖受到抑制,且呈时间和剂量依赖性;并抑制SGC-7901细胞生长周期,其细胞周期阻滞于S期,5、10μmol/L5-Aza-CdR实验组细胞凋亡率显著高于对照组,且差异有统计学意义(7.13%±0.87%,13.34%±1.12% vs 3.69%±...     

5-氮杂-2′-脱氧胞苷对肺癌SPC-A-1细胞p16、MGMT基因甲基化及其表达的影响

目的观察5-氮杂-2′-脱氧胞苷（5-Aza-CdR）对体外培养的肺癌SPC-A-1细胞p16、MGMT基因启动子区DNA甲基化状态及其表达的影响,探讨肺癌细胞p16、MGMT基因失活的机制及去甲基化制剂对p16、MGMT基因表达的调控。方法 5-Aza-CdR处理体外培养的肺癌SPC-A-1细胞,甲基化特异性PCR（MSP）法检测用药前后细胞p16、MGMT基因的甲基化状态,RT-PCR法检测用药前后细胞p16、MGMT mRNA。结果加入5-Aza-CdR前,SPC-A-1细胞p16、MGMTmRNA表达缺失,其启动子区域表现为DNA甲基化。加入5-Aza-CdR后,SPC-A-1细胞中p16、MGMT基因呈现DNA去甲基化,而且表达缺失的p16、MGMT mRNA重新表达。结论启动子区高甲基化是肺癌细胞p16、MGMT基因失活的主要原因之一,去甲基化制剂5-Aza-CdR能逆转p16、MGMT基因甲基化状态,从而调控p16、MGMT基因表达。     

5-氮杂-2′-脱氧胞苷对胃癌AGS细胞CHFR基因去甲基化作用及意义

目的观察5-氮杂-2′-脱氧胞苷（5-Aza-CdR）对胃癌AGS细胞CHFR基因去甲基化的作用,并探讨其临床意义。方法分别采用BSP和RT-PCR技术检测5-Aza-CdR处理前后胃癌AGS细胞CHFR基因启动子甲基化状态及其mRNA。结果 AGS细胞CHFR基因启动子在5-Aza-CdR处理前呈现高甲基化状态（甲基化率≥60%）,其mRNA表达完全缺失;5-Aza-CdR处理后则表现为低或无甲基化状态（甲基化率≤20%）,其mRNA表达恢复正常。结论 CHFR基因启动子在AGS细胞中呈高甲基化状态,5-Aza-CdR能显著逆转其CHFR基因异常甲基化,诱导CHFR基因表达,为胃癌的治疗提供新思路。     

5-氮杂-2’-脱氧胞苷对胰腺癌细胞PANC1的组织因子途径抑制物-2表达及CpG岛甲基化的影响

目的 探讨甲基化酶抑制剂5-氮杂-2'-脱氧胞苷(5-Aza-dC)对胰腺癌细胞系PANCI的抑癌基因组织因子途径抑制物2(tissue factor pathway inhibitor 2,TFPI-2)甲基化水平及基因表达的影响.方法 应用1×10-7、5 × 10-7、1×10-6mol/L的5-Aza-dC处理胰腺癌细胞系PANCI.用甲基化特异性PCR(MSP)、RT-PCR及蛋白质印迹法检测细胞TFPI-2基因的甲基化状态、mRNA及蛋白的表达.结果 未经5-Aza-dC处理的PANCI细胞的TFPI-2基因CpG岛为完全甲基化,无TFPI-2 mRNA及蛋白的表达.1×10-7、5×10-7、1×10-6mol/L的5-Aza-dC处理后,PANC1细胞的TFPI-2基因CpG岛甲基化逆转,从不完全甲基化到完全非甲基化;TFPI-2 mRNA相对表达量分别为0.211±0.087、0.327 ±0.068、0.609±0.017;TFPI-2蛋白相对表达量为0.429±0.121、0.675±0.044、1.132±O,124,呈剂量依赖性增加(P＜0.05).结论 胰腺癌细胞系PANC1的TFPI-2启动子高甲基化可能是导致该基因表达下调甚至失活的主要原因.5 -Aza-dC能够逆转其高甲基化状态,并诱导TFPI-2 mRNA及蛋白重新表达.     

5-Aza-CdR对胃癌细胞系BGC823生长及p27 kipl基因异常甲基化的影响

选择浓度为1×10-6mol/L的5-氮杂-2'-脱氧胞苷(5-Aza-CdR)处理体外培养的BGC823细胞后,用AO染色检测药物处理后细胞增殖情况;MSP法检测用药前后细胞中Apaf-1基因的甲基化状态;RT-PCR法检测用药前后细胞中p27kipl的mRNA表达的变化.结果 显示,药物作用细胞增殖明显受到抑制,p27kipl基因的甲基化状态得到了逆转,p27kipl基因的mRNA表达得到增加.认为5-Aza-CdR对BGC823细胞具有增生抑制作用,p27kipl基因的表达情况与其甲基化状态的改变有关.     

5-Aza—CdR对胃癌细胞系BGC823生长及p27kip1基因异常甲基化的影响

选择浓度为1×10-6mol/L的5-氮杂-2'-脱氧胞苷(5-Aza-CdR)处理体外培养的BGC823细胞后,用AO染色检测药物处理后细胞增殖情况;MSP法检测用药前后细胞中Apaf-1基因的甲基化状态;RT-PCR法检测用药前后细胞中p27kipl的mRNA表达的变化.结果 显示,药物作用细胞增殖明显受到抑制,p27kipl基因的甲基化状态得到了逆转,p27kipl基因的mRNA表达得到增加.认为5-Aza-CdR对BGC823细胞具有增生抑制作用,p27kipl基因的表达情况与其甲基化状态的改变有关.     

胃癌细胞PTEN基因启动子区甲基化与蛋白表达的关系及意义

目的探讨胃癌细胞中抑癌基因PTEN5’启动子区CpG岛甲基化状态与其蛋白表达的关系。方法采用甲基化特异性聚合酶链反应（MSP）方法检测不同分化程度的胃癌细胞（HGC-27,MGC-803,BGC-823,SGC-7901）中PTEN基因启动子区域甲基化状态。并通过Western blot法检测该4种细胞中PTEN蛋白的表达。结果除SGC-7901外,其他三种胃癌细胞PTEN基因都有不同程度的甲基化,并随着胃癌细胞分化程度的降低。PTEN启动子区甲基化逐渐增强（P〈0．01）;PTEN蛋白表达逐渐减弱（P〈0．01）。PTEN蛋白表达与其启动子区高甲基化之间呈负相关。结论PTEN基因启动子区异常甲基化可能导致该基因失活,使其蛋白表达减少甚至缺失,这可能是导致胃癌发生、发展的重要机制之一。     

5-Aza-dC及TSA对人胃癌细胞株SGC-7901 Runx3基因甲基化及表达水平的影响

目的:探讨5-Aza-dC及TSA对人胃癌细胞系SGC-7901中抑癌基因Runx3启动子区甲基化、mRNA及蛋白表达水平的影响.方法:单独或联合应用5-Aza-dC及TSA处理体外培养的SGC-7901细胞,提取各组细胞的DNA、RNA及蛋白质,应用甲基化特异性定量PCR法(QMSP)检测Runx3基因启动子区甲基化状态,逆转录PCR法(RT-PCR)检测Runx3mRNA的表达,免疫印迹法(Western blotting)法检测Runx3蛋白表达水平.结果:5-Aza-dC和TSA均能降低Runx3基因启动子区的甲基化水平(5-Aza-dC组及TSA组分别为对照组的0.70倍、0.63倍),提高mRNA表达水平(0.29±0.01、0.28±0.03vs0.14±0.03,P<0.05)及蛋白表达水平(0.35±0.02、0.37±0.02vs0.09±0.01,P<0.05);与单独使用5-Aza-dC和TSA相比,两药联合组Runx3基因启动子区甲基化水平(对照组的0.37倍)及mRNA表达水平(0.45±0.02)和蛋白表达水平(0.50±0.01)均较单药组效果更明显(P<0.05).结论:5-...     

5-Aza-CdR对人食管癌细胞株中T-cadherin基因表达和细胞增殖的影响

背景：T-cadherin在肿瘤的发生中可能扮演肿瘤抑制基因的角色．在食管癌等多种肿瘤中的表达明显下降。目的：探讨去甲基化制剂5-氮杂-2’-脱氧胞苷（5-Aza-CdR）对人食管癌细胞株EC109中T—cadherin基因表达和细胞增殖的影响。方法：常规培养人食管癌细胞株EC109．并分为5μmol／L5-Aza-CdR组和对照组。以甲基化特异性PCR（MSP）法检测T-cadherin基因启动子区甲基化状态．RT-PCR和蛋白质印迹法分别检测T-cadherinmRNA和蛋白表达,MTr法检测EC109细胞增殖。结果：对照组EC109细胞中T-cadhefin基因启动子区呈异常甲基化状态．5-Aza-CdR干预可逆转甲基化状态。与对照组相比,5-Aza-CdR组T-cadherin基因mRNA和蛋白表达均显著增高（P〈0．01）．细胞增殖明显受到抑制。结论：去甲基化制剂5-Aza-CdR通过逆转食管癌细胞中T-cadherin基因启动子区甲基化状态来增强其表达．并抑制肿瘤细胞增殖．     

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.