球囊扩张术对血管平滑肌细胞COX-2表达的影响及其增殖凋亡分子机制研究

目的研究球囊扩张术后血管平滑肌细胞(VSMC)中环氧化酶2(COX-2)mRNA表达及选择性COX-2抑制剂处理VSMC后,细胞周期蛋白D1(Cyclin D1)、凋亡蛋白Bcl-2的变化,明确COX-2表达与VSMC增殖凋亡分子机制的相关性。方法用RT-PCR检测20只兔腹主动脉球囊拉伤前后VSMC中COX-2的mRNA表达水平；体外实验将选择性COX-2抑制剂NS-398,作用于兔VSMCs,运用MTF法分别于0,24h,48h,72h检测细胞增殖状态；流式细胞仪观察NS-398对细胞凋亡的影响,进一步采用Western blot检测药物作用前后Cyclin D1、Bcl-2的表达。结果兔腹主动脉球囊拉伤后VSMC COX-2mRNA的表达水平明显高于正常VSMC(P＜0．01),为正常组2．42倍；对照组S及G2/M期DNA百分含量与处理组比值分别为1．31,1．62(P＜0．01),NS-398呈时间、剂量依赖性方式抑制VSMC增殖,促进其凋亡。同时,72h时空白组与NS-398(75μmol/L)处理组Cyclin D1、Bcl- 2表达水平比值分别为2．37和3．81(P＜0．01),故两者表达水平随作用时间延长而下降。结论COX-2在球囊扩张术后血管平滑肌细胞中高表达可能在VSMC过度增殖、凋亡受阻中起重要作用。选择性COX-2抑制剂NS-398可能通过Cyclin D1,Bcl-2影响VSMC的增殖与凋亡,提示COX-2抑制剂可作为预防血管成形术后再狭窄新的候选药物。     

COX-2抑制剂NS398调控PPARs信号转导通路抑制结肠癌细胞增殖的分子机制

目的:观察选择性COX-2抑制剂NS-398对结肠癌细胞系SW480中PPARs信号转导通路的影响,以期初步阐明选择性COX-2抑制剂抗结直肠癌非COX-2依赖性途径的作用机制．方法:应用RT-PCR检测结肠癌细胞系SW480中COX-2 mRNA表达水平,用选择性COX-2抑制剂NS-398处理结肠癌细胞系SW480．Western blot检测PPARs信号转导通路成员表达,四甲基偶氮唑盐(MTT)法检测细胞增殖状态,流式细胞技术检测细胞周期与凋亡情况．结果:结肠癌细胞系SW480中未检测到COX-2 mRNA表达,NS-398(75μmol／L)作用于SW480细胞72 h后,G1期细胞比率由31．2％上升至40．6％,S期细胞比率由52．8％下降至41．2％,细胞增殖受抑制．PPARα,PPARδ,PPARγ,cyclin D1与Bcl-xl表达水平随NS-398作用时间延长而下降．结论:选择性COX-2抑制剂NS-398可能通过非COX-2依赖途径影响结肠癌细胞的增殖．     

环氧合酶-2抑制剂对结肠癌细胞株的体外研究

目的 观察选择性环氧合酶-2（COX-2）抑制剂对COX-2高表达的结肠癌细胞株HT-29增殖和凋亡的影响，明确以COX2为靶点治疗结肠癌的作用途径以及与COX-2活性、表达水平的相关关系。方法 将选择性COX-2抑制剂NS-398作用于结肠癌细胞系HT29，运用MTT法检测细胞增殖状态。流式细胞仪观察NS-398对细胞凋亡的影响。进一步用逆转录聚合酶链式反应（RT-PCR）检测药物作用前后HT-29中COX-2mRNA表达。ELISA法测定前列腺素E2（PGE2）水平。Western blot检测药物作用前后细胞周期素D1、Bcl-2的表达。结果 结肠癌细胞系HT-29中COX-2 mRNA高表达，NS-398呈时间和剂量依赖性抑制HT-29细胞增殖，促进其凋亡。加入NS-398的HT-29细胞中COX-2mRNA表达水平无明显变化（P〉0．05），PGE2却显著下降（P〈0．01）。72h时空白组与NS-398（75μmol／L）处理组细胞周期素D1、Bcl-2表达水平比值分别为2．21和3．25（P〈0．01），两者表达水平随作用时间延长而下降。结论 选择性COX-2抑制剂NS-398不影响结肠癌细胞COX-2 mRNA表达水平，而与其活性相关（PGE2水平）．可能通过细胞周期素D1、Bcl-2影响结肠癌细胞系HT-29的增殖与凋亡，揭示了COX-2为靶点治疗结肠癌的分子机制。     

NS-398对人胃癌细胞株增殖及COX-2表达的影响

目的 体外观察选择性环氧化酶2(COX-2)抑制剂NS-398对人胃癌细胞株SGC7901细胞增殖及COX-2表达的影响。方法 采用噻唑蓝(MTT)法观察NS-398对SGC7901细胞增殖的影响，流式细胞仪(FCM)研究NS-398对SGC790l细胞凋亡的作用．免疫细胞化学观察COX-2蛋白的表达。结果 体外NS-398能减少SGC790l细胞株COX-2的表达．对SGC7901有细胞毒作用．可增加细胞凋亡率。结论 体外NS-398对SGC7901细胞增殖有抑制作用。可能与抑制COX-2表达及诱导细胞凋亡有关。     

肝细胞生长因子受体在血管平滑肌细胞增殖凋亡中的表达

目的研究球囊扩张术后血管平滑肌细胞(VSMCs)中肝细胞生长因子(HGF)及其受体(c-Met)mRNA表达的变化,明确HGF受体与VSMCs增殖凋亡分子机制的相关性。方法用逆转录聚合酶链式反应检测36只兔腹主动脉球囊损伤前后不同时间点VSMCs中c-Met的mRNA表达水平;体外实验将选择性c-Met蛋白抑制剂NK-4作用于免VSMCs,运用MTF分别于0、24、48及72h检测细胞增殖状态;流式细胞仪观察NK-4对细胞凋亡的影响,进一步采用Western blot检测药物作用前后细胞周期蛋白(Cyclin D1)、凋亡蛋白(Bcl-2)的表达。结果球囊损伤后VSMCs c-Met mRNA的表达水平明显高于正常VSMCs(P＜0．01),平均为对照组2．42倍;对照组S及G_2/M期DNA百分含量与处理组比值分别为1．31,1．62(P＜0．01),NK-4呈时间、剂量依赖性方式抑制VSMCs增殖,促进其凋亡。72h时对照组与NK-4(1．0mg/L)处理组Cyclin D1、Bcl-2表达水平比值分别为2．37和3．81(P＜0．01),故两者表达水平随NK-4作用时间延长而下降。结论c-Met在球囊扩张术后血管平滑肌细胞中高表达可能在VSMCs过度增殖、凋亡受阻中起重要作用。选择性c-Met蛋白抑制剂NK-4可能通过Cyclin D1,Bcl-2影响VSMCs的增殖与凋亡,提示c-Met抑制剂可作为预防血管成形术后再狭窄新的候选药物。     

JAK2/STAT3信号通路在阿托伐他汀抗大鼠血管平滑肌细胞增殖凋亡中的作用研究

目的探讨阿托伐他汀对大鼠血管平滑肌细胞(VSMCs)非调脂作用机制与转录信号传导子和激活子3(Stat3)信号传导通路的关系,明确其细胞内信号传导机制。方法分别将阿托伐他汀、酪氨酸激酶抑制剂AG490及二者联合作用于大鼠VSMCs,应用MTT法检测细胞增殖状态;流式细胞仪观察药物对细胞凋亡的影响,进一步用蛋白免疫印迹法(Western blot)检测药物作用前后 Stat3通路相关蛋白JAK2、STAT3、Cyclin D1、Bcl-2的表达及磷酸化活性。结果阿托伐他汀及AG490 都呈浓度依赖性方式抑制大鼠VSMCs增殖水平,促进其凋亡,二者联合应用则具协同作用。阿托伐他汀及AG490处理VSMCs后p-JAK2、p-Stat3、Cyclin D1、Bcl-2蛋白表达水平随作用时间延长而下降 (P<0．05),并且联合组蛋白表达水平较单独处理组相比有显著性差异(P<0．01)。结论阿托伐他汀对大鼠VSMCs非调脂作用机制与癌基因Star3信号通路高度相关,与酪氨酸激酶抑制剂AG490联合应用则具协同作用,可能通过作用于JAK2／Stat3下游靶基因Cyclin D1、Bcl-2影响其增殖及凋亡。     

环氧合酶-2选择性抑制剂NS-398诱导食管癌细胞EC 9706凋亡及其机制的探讨

目的 观察环氧合酶-2(COX-2)选择性抑制剂NS一398对食管癌细胞株EC 9706增殖及凋亡的影响,砌究其对凋亡抑制蛋白Survivin和Caspase-3表达的影响,探讨NS-398诱导Ec 9706细胞凋亡的作用机制.方法 NS-398作用EC 9706细胞后,MTT法测定NS-398对人食管癌EC 9706细胞增殖的抑制率;DNA片段分析法和流式细胞仪检测细胞凋亡;免疫细胞化学检测Survivin和Caspase-3蛋白表达变化.结果 NS-398(10～100μmol/L)对EC 9706细胞生长有抑制作用,随浓度升高、时间延长抑制作用增强,并诱导EC 9706细胞凋亡,呈剂量-时间效应关系;NS-398可降佴Survivin蛋白表达,增加Caspase-3蛋白表达.结论 NS-398可诱导人食管癌细胞株EC 9706凋亡,其机制可能与下调Survivin表达及激活Capase-3表达有关.     

选择性环氧合酶-2抑制剂与COX-2/5-脂氧合酶双酶抑制剂对食管鳞状细胞癌细胞增殖的影响

目的比较选择性环氧合酶-2（COX-2）抑制剂与COX-2/5-脂氧合酶（5-LOX）双酶抑制剂对食管鳞状细胞癌（ESCC）细胞增殖的影响,探讨单一抑制COX-2对抑制ESCC细胞增殖可能存在的局限性。方法 COX-2/5-LOX双抑制剂licofelone和选择性COX-2抑制剂NS-398分别作用于ESCC细胞株TE-1,设药物处理组、溶媒（DMSO）对照及空白对照组。两种药物分别以25μmol/L、50μmol/L、75μmol/L和100μmol/L浓度作用24 h及48 h。四唑单钠盐（CCK-8）法检测细胞增殖;RT-PCR和W esternb lot检测mRNA及蛋白表达;ELISA法检测PGE2和LTB4含量;流式细胞术检测细胞周期。结果 TE-1细胞的浓度及时间依赖性增殖抑制只出现于licofelone处理组。licofelone及NS-398对COX-2 mRNA、蛋白及下游产物PGE2表达均有时间、浓度依赖性抑制作用（P〈0.05）,但仅licofelone处理组出现5-LOX mRNA、蛋白及下游产物LTB4的时间、浓度依赖性表达抑制。100μmol/L licofe-lone及50μmol/L NS-398作用24 h后TE-1细胞分别有67.1%、63.8%处于G0/G1期,显著高于对照组（P〈0.05）。结论单一抑制COX-2并不能稳定抑制TE-1细胞的增殖。较高浓度NS-398可增加5-LOX分流,减弱COX-2抑制对细胞增殖的负性影响。     

环氧化酶-2选择性抑制剂抑制人食管癌细胞的生长及其诱导凋亡

目的:探讨NS-398对食管癌细胞的生物学效应及可能的作用机制.方法:常规方法培养食管癌Eca-109和TE-13细胞,以不同浓度NS-398(5,10,20,40,80 μmol/L)处理24,48,72 h.采用四甲基唑蓝法(MTT)检测NS-398对Eca-109和TE-13细胞生长的抑制作用;流式细胞仪(FCM)检测细胞凋亡及COX-2,Bcl-2,Bax蛋白的表达;TUNEL法检测2种细胞凋亡情况;用放射免疫分析(RIA)检测培养液上清中前列腺素E2(PGE2)含量.结果:NS-398可抑制2种细胞的生长,并随药物浓度的增高及作用时间的延长抑制率逐渐增高,并使2种细胞产生的PGE2明显降低.NS-398使2种细胞G0/G1期细胞显著增多,S期细胞显著减少(Eca-109:F=22.39,P＜0.01;TE-13:F=46.99,P＜0.01),并引起了明显的细胞凋亡.NS-398使2种细胞COX-2和Bcl-2表达显著减少,而Bax表达显著增高.COX-2和Bcl-2的表达呈显著正相关(Eca-109:r=0.925,P＜0.01;TE-13:r=0.925,P＜0.01),COX-2和Bax表达呈显著负相关(Eca-109:r=-0.937,P＜0.01;TE-13:r=-0.703,P＜0.01)、Bax和bcl-2表达呈显著负相关(Eca-109:r=-0.926,P＜0.01;TE-13:r=-0.753,P＜0.01).结论:NS-398可抑制食管癌细胞的增殖并可诱导其凋亡,应用COX-2选择性抑制剂对食管癌进行化学预防或辅助治疗具有可能性.     

选择性环氧合酶-2抑制剂对HSC-T6细胞增殖的抑制作用

目的 观察选择性环氧合酶-2抑制剂NS-398对肝星状细胞系HSC-T6细胞增殖的抑制作用,并探讨其可能的机制. 方法采用不同浓度的NS-398作用于HSC-T6,四甲基偶氮唑盐法检测HSC-T6细胞增殖情况,乳酸脱氢酶法检测NS-398对HSC-T6细胞的毒性作用、流式细胞仪检测HSC-T6细胞周期的改变,以EliVisionTMplus细胞免疫化学法检测HSC-T6中COX-2、增殖细胞核抗原(PCNA)蛋白表达的变化.多组数据间的比较采用单因素方差分析或独立样本T检验,计数资料采用χ2检验. 结果在20～160μamol/L浓度范围内,NS-398以剂量和时间依赖性地抑制HSC-T6增殖(P<0.01).90、120、150 μmol/L的NS-398作用HSC-T6 48 h后,细胞周期分析结果显示S期细胞稍增多,G2/M期细胞显著增加,各组之间细胞周期构成差异具有统计学意义(χ2=12.35,P<0.05).以120 μmol/L NS-398作用HSC-T6 48 h后,PCNA阳性细胞百分比为28.91%±0.11%,与对照组(85.99%±0.13%)比较,差异具有统计学意义(P<0.01);COX-2的阳性细胞百分比为13.80%±0.43%,与对照组(14.07%±0.59%)比较,差异无统计学意义(P>0.05).结论 NS-398可以显著抑制HSC-T6增殖,使其发生G2/M期阻滞,其作用具有剂量与时间依赖性,NS-398可能通过抑制HSC中PCNA的表达而抑制其增殖,但小影响COX-2的表达.     

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.