亚细胞毒性剂量As2O3增加胃癌细胞对rhTRAIL的敏感性及其机制

目的:研究亚细胞毒性剂量As2O3对rhTRAIL诱导胃癌细胞凋亡的影响及其机制．方法:人胃腺癌细胞株SGC 7901以As2O3(1μmol／L),rhTRAIL(500μg／L)及两者联用处理:采用AnnexinV-FITC和PI双染色流式细胞仪检测细胞凋亡:用间接免疫荧光染色结合流式细胞技术检测细胞表面TRAIL R1／DR4和TRAIL R2／DR5分子表达;RT-PCR方法检测TRAIL R1／DR4和TRAIL R2／DR5 mRNA表达．结果:rhTRAIL在单用或与As2O3联用时均可以诱导胃癌SGC7901细胞凋亡,并且随着作用时间延长(12-72 h),细胞凋亡率逐渐增高．As2O3与rhTRAIL联用24,48,72 h后,SGC7901细胞凋亡率分别显著高于单用rhTRAIL处理相同时间细胞(36．49％±7．12％,47．13％±3．44％,55．63％±7．16％vs 29．78％±3.18％、38．56％±1．89％,43．12％±6．23％,P<0．05); As2O3单用或联用rhTRAIL处理SGC7901细胞24 h后,细胞表面TRAIL R1／DR4和TRAIL R2／DR5分子的平均荧光密度(MFI)较对照组细胞显著增加(R1／DR4:29．44±4．29,26．14±3．40 vs13．45±3．81,P<0．05或P<0．01;R2／DR5:28．04±0．79．3 1．47±4．56vs16．45±5．07,P<0．05或P<0．01);与此同时,TRAIL R1／DR4和TRAIL R2／DR5mRNA表达水平增高．结论:亚细胞毒性剂量As2O3可能通过增加TRAIL R1／DR4和TRAIL R2／DR5基因表达、上调细胞表面TRAIL死亡受体从而增加胃癌细胞SGC7901对rhTRAIL的敏感性,两药可能联合用于治疗胃癌．     

紫杉醇对TRAIL诱导胃癌SGC7901细胞凋亡的影响

目的探讨紫杉醇对TRAIL诱导的胃癌SGC7901细胞凋亡的影响。方法采用MTT法测定细胞活力、采用流式细胞仪检测细胞凋亡、Western blot检测蛋白表达。结果在胃癌SGC7901细胞中,100 ng/ml的TRAIL导致轻度的增殖抑制和细胞凋亡,TRAIL（100 ng/ml）联合紫杉醇（7.19μg/ml,24 h的IC50剂量）引起明显的细胞增殖抑制和诱导凋亡作用（P〈0.05）。TRAIL单药没有改变死亡受体5（DR5）的蛋白表达,而7.19μg/ml紫杉醇作用于胃癌SGC7901细胞后明显上调了DR5的蛋白表达。TRAIL和紫杉醇联合作用后,也有DR5蛋白的明显上调。结论紫杉醇通过上调DR5的蛋白表达增强了TRAIL诱导的胃癌SGC7901细胞凋亡。     

蛋白酶体抑制剂单用或联合顺铂对人胃癌细胞的抑制效应

背景：蛋白酶体抑制剂通过阻断泛素．蛋白酶体通路中的蛋白降解，致使错误折叠蛋白或受破坏蛋白堆积．启动热休克反应并进一步导致细胞死亡，对多种恶性肿瘤细胞具有抑制作用。目的：探讨蛋白酶体抑制剂Z-Leu—Leu—Phe-CHO（ZLLFC）单用或联合顺铂对人胃癌细胞株SGC-7901体外增殖和凋亡的影响及其对肿瘤多药耐药相关切除修复交叉互补基因1（ERCC1）mRNA表达的影响。方法：将ZLLFC和顺铂单独或联合作用于SGC-7901细胞。以甲基噻唑基四唑（MITT）法检测细胞存活率，透射电子显微镜观察凋亡细胞形态，流式细胞仪检测细胞凋亡率．逆转录聚合酶链反应（RT—PCR）检测ERCC1 mRNA表达。结果：ZLLFC或顺铂单独作用后，SGC-7901细胞存活率较对照组显著降低（P〈0．01），呈现轻度凋亡形态；ZLLFC联合顺铂组细胞存活率较单用顺铂组显著降低（P〈O．01），细胞凋亡率显著升高（P〈O．01），呈现明显凋亡形态。联合组ERCC1 mRNA表达显著低于单用顺铂组（P〈0．01）。结论：蛋白酶体抑制剂ZLLFC能轻度抑制人胃癌细胞株SGC．7901生长，诱导细胞凋亡，与顺铂联用具有协同抑制效应。ZLLFC可能通过下调ERCC1转录水平逆转顺铂耐药，从而增强顺铂的抗肿瘤作用。     

肿瘤坏死因子相关凋亡诱导配体诱导胃癌细胞凋亡机制的研究

背景：肿瘤坏死因子相关凋亡诱导配体（TRAIL）可诱导不同胃癌细胞株的凋亡，但凋亡的途径尚不清楚。目的：通过研究TRAIL诱导胃癌细胞凋亡的作用机制，为TRAIL的临床应用提供理论依据。方法：应用逆转录聚合酶链反应（RT—PCR）法检测SGC-7901胃癌细胞TRAIL受体（TRAILR），包括死亡受体TRAILR1、TRAILR2和诱惑受体TRAILR3、TRAILR4的表达；应用免疫组化法检测SGC-7901胃癌细胞Bcl-2和caspase-3的表达．并观察两者在不同浓度（50ng／ml和500ng／ml）的TRAIL处理后的变化。结果：SGC-7901胃癌细胞仅表达TRAILR1和TRAILR2，不表达TRAILR3、TRAILR4。TRAIL可引起SGC-7901胃癌细胞Bcl-2阳性表达，不同浓度的TRAIL作用12h、24h、48h其表达无影响；与对照组比较，不同浓度的TRAIL作用24h后SGC-7901胃癌细胞caspase-3表达均有显著增加（P〈0．01）。结论：TRAIL诱导胃癌细胞凋亡是因胃癌细胞仅表达TRAILR1、TRAILR2，不表达TRAILR3、TRAILR4。TRAIL是通过TRAILR1、TRAILR2增加细胞内caspase-3的表达而导致胃癌细胞凋亡，其诱导胃癌细胞凋亡的作用不受Bcl-2的影响。     

As2O3对TRAIL抑制人肺癌A549细胞增殖及调节DR4 mRNA、DR5 mRNA表达作用的影响

目的观察三氧化二砷（As2O3）对人肿瘤坏死因子相关凋亡诱导配体（TRAIL）抑制人肺癌A549细胞增殖作用的影响及机制。方法体外培养A549细胞至对数生长期后随机分为As2O3组、TRAIL组、联合组及对照组,As2O3组分别加入1、10μmol／LAs2O3,TRAIL组加入100μg／LTRAIL,联合组分别加入1μmol／LAs2O3＋100μg/LTRAIL、10μmol／LAs2O3＋100μg／LTRAIL,对照组加入DMEM培养液。四组均继续培养24、48、72h,采用四甲基偶氮唑蓝（MTT）比色法检测细胞生长情况,计算细胞增殖抑制率（IR）;用RT-PCR法检测死亡受体4（DR4）mRNA、死亡受体5（DR5）mRNA表达变化。结果 联合组IR显著高于As2O3,组及TRAIL组,尤以作用48h和72h为著（P均〈0．05）;联合组DR4 mRNA和DR5 mRNA表达均明显强于As2O3组及TRAIL组（P均〈0.05）。结论 As2O3,可增强TRAIL对A549细胞增殖的抑制作用,机制可能为上调DR4m RNA和DR5 mRNA表达;此为肺癌的临床靶向治疗根供了依据．     

三氧化二砷诱导胃癌细胞凋亡及其对C-myc和TGF-β1表达的影响

目的 探讨三氧化二砷（As2O3）对体外培养的人胃癌细胞SGC-7901生长的抑制和诱导细胞凋亡的作用。方法 用MTT法检测药物效应，透射电镜及流式细胞仪观察As2O3处理SGC-7901细胞后细胞周期细胞凋亡。细胞免疫化学观察As2O3处理后SGC-7901细胞TGF-β1及C-myc表达的变化。结果 ①MTT法证实As2O3对SGC-7901细胞生长有抑制作用，并呈剂量．效应关系。②流式细胞仪分析As2O3处理SGC-7901细胞后细胞滞留于G2／M期，并可见凋亡峰。③透射电镜可见SGC-7901细胞出现典型的细胞凋亡及坏死形态学改变。④As2O3导致C—myc表达的波动，下调TGF-β1，表达。结论As203对人胃癌细胞SGC-7901有抑制作用，其抑制作用可能通过导致C—myc基因表达波动，诱导胃癌细胞凋亡和坏死、阻抑细胞周期进程，抑制SGC-7901细胞增殖。同时通过下调TGF-β1表达阻止胃癌的恶性进程。     

低氧下As2O3对人胃癌细胞C-met因子表达的影响

目的进一步探讨三氧化二砷（As2O3）的抗肿瘤作用机制。方法观察低氧条件下As2O3对体外培养的人胃癌细胞SGC 790IC-met因子表达的影响。用CoCl2制造低氧条件，设常氧组、低氧组、低氧加药物组和常氧加药物组。用细胞免疫化学法观察As2O3（5μmol／L）作用于SGC-7901细胞48h后细胞C-met表达情况。结果低氧下As2O3导致C-met表达明显下调。结论低氧下As2O3能降低SGC-7901细胞C-met因子表达（P〈0．01），但其下调作用较常氧组低（P〈0．01）。     

TRAIL体外诱导人肝星形细胞LX-2凋亡作用及调控机制

目的研究肿瘤坏死因子相关凋亡诱导配体（TRAIL）诱导肝星形细胞凋亡情况及调控机制。方法用RT-PCR检测LX-2中α-SMAmRNA和DR5mRNA的表达;MTT比色法、流式细胞术检测外源性TRAIL对LX-2细胞增殖和诱导细胞凋亡的影响;采用Westernblot检测Bax、Caspase3表达。结果培养的LX-2表达α-SMAmRNA和DR5mRNA逐渐增加,TRAIL可以抑制其细胞增殖,与剂量相关（P〈0.05）。与对照组比较,TRAIL诱导活化的LX-2细胞凋亡明显增加（P〈0.05）,Western blot分析显示TRAIL作用下,LX-2线粒体Bax、细胞质Caspase3表达上调。结论外源性TRAIL可以诱导活化的LX-2凋亡,其机制与DR5及线粒体Bax表达上调有关。     

As2O3对肾癌细胞增殖、凋亡的影响及意义

目的观察As2O3对肾癌细胞株786-0增殖、凋亡及细胞内X染色体连锁凋亡抑制蛋白（XIAP）表达的影响,探讨其意义。方法取对数生长期786-0,分别经0．5、1．0、2．0μmol／L的As2O3处理后,采用MTT比色法检测细胞生长情况,流式细胞仪测算细胞凋亡率,蛋白质印迹法及RT—PCR法检测细胞中的XIAP及其mRNA。结果0．5、1．0、2．0μmol／LAs2O3均可抑制786-0增殖。随着作用时间的延长,细胞生长抑制率升高（P均〈0．01）;随着As2O3浓度的增加,细胞凋亡率升高（P均〈0．01）、细胞内XIAP及其mRNA表达明显下调（P均〈0．05）。结论As2O3可抑制786-0增殖,并诱导其凋亡。这一作用与As2O3抑制786-0中XIAP及其mRNA表达有关。     

三氧化二砷及干扰素对U266细胞TRAIL和其受体表达的影响

目的 探讨三氧化二砷（As2O3）联合IFNα-2a治疗人多发性骨髓瘤（MM）的可行性。方法将人MM细胞系U266细胞株随机分为4组,空白对照组不行特殊处理,As2O3组加入As2O3,IFNα-2a组加入IFNα-2a,As2O3＋IFNα-2a组同时加入As2O3及IFNα-2a。孵育48h后用双标记流式细胞术检测细胞凋亡率,用流式细胞仪检测细胞肿瘤坏死因子相关凋亡诱导配体（TRAIL）及其受体表达。结果As2O3＋IFNα-2a组细胞凋亡率、TRAIL及其受体表达均显著高于其他三组（P〈0．05）,空白对照组TRAIL及其受体表达均显著低于其他三组（P〈0．05）。结论As2O3,及IFNα-2a均可上调TRAIL及其受体表达,促进U266细胞凋亡,且两者有协同作用;此为临床治疗MM提供了新的思路。     

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.