三氧化二砷对慢性髓系白血病细胞周期及Survivin表达的影响

目的研究三氧化二砷(As2O3)对慢性髓系白血病细胞(K562)的作用特点及其机制。方法不同浓度As2O3作用于K562细胞后，四唑盐(MTT)比色法分析细胞增殖；流式细胞术检测细胞周期分布、细胞凋亡及Survivin抗原表达；RT-PCR检测Survivin mRNA的表达。结果2—10μmoL／L的As2O3能有效抑制K562细胞增殖，但未能诱导明显的细胞凋亡。周期分析显示，G2／M期细胞比例显著增多；同时G2／M细胞周期依赖性表达的Survivin mRNA和蛋白表达增加。结论As2O3明显抑制K562细胞的生长，其机制是诱导G2／M期细胞周期停滞。Survivin表达上调可能是K562细胞对As2O3诱导凋亡抵抗的机制之一。     

三氧化二砷对K562细胞生长及Ki-67和Survivin表达的影响

目的：探讨三氧化二砷(As2O3)对K562细胞生长的影响及K562细胞对As2O3的抵抗机制。方法：以不同浓度As2O3作用于K562细胞后，用四唑盐(MTT)比色法分析细胞的生长增殖，用台盼蓝排斥试验观察细胞活力，流式细胞术检测细胞凋亡以及Ki-67抗原和Survivin的表达。结果：2μmol／L As2O3能明显抑制K562细胞生长，但细胞活力、增殖相关抗原Ki-67的降低和凋亡发生在5μmol／L As2O3作用48h后才较为明显；同时As2O3作用后抗凋亡蛋白Survivin的表达均有不同程度的增加。结论：As2O3能有效抑制K562细胞的生长，但对细胞增殖能力的抑制及凋亡的诱导作用不如前者明显；Survivin的表达增加可能是K562细胞对As2O3诱导凋亡的抵抗机制之一。     

砷对人胶质瘤细胞周期调控相关基因表达的影响

目的比较三氧化二砷（As2O3）对两种不同p53表型胶质瘤细胞U87MG、T98G细胞周期调控相关基因表达的影响。方法应用功能分类细胞周期基因芯片技术，筛选出As2O3作用于两种胶质瘤细胞U87MG、T98G后与细胞周期调控表达有差异的基因，并对3条有共性表达的基因进行Western印迹分析；四甲基偶氮唑蓝（MTT）法检测细胞生长抑制率；流式细胞仪分析细胞周期改变。结果MTT分析表明：As2O2对2个细胞系的生长有抑制作用，且抑制率具有浓度和时间的依赖性，砷作用72h后，U87MG和T98G细胞系的生长抑制率为50％（IC50）时，其浓度分别为1．78、3．55μmol／L。As2O3可以将U87MG和T98G细胞周期阻滞于G0／G1和G2／M期。U87MG细胞在加入As2O3后，差异表达2倍以上的基因共11条，表达上调的有5条，下调的有6条。T98G细胞在加入As2O3后，差异表达的基因共13条，表达上调的有9条，下调的有4条。Western分析显示，As2O3能上调2个胶质瘤细胞系的P53蛋白水平，同时降低细胞周期蛋白B1、D1表达。结论As2O3通过将细胞周期阻滞于G0／G1和G2／M期来抑制U87MG和T98G细胞的增殖；p53、CyclinB、CylinD等基因表达与As2O3诱导胶质瘤细胞周期阻滞的发生有关。     

三氧化二砷诱导人肝癌SMMC-7721细胞凋亡及对OPN表达的影响

目的探讨三氧化二砷（As2O3）治疗肝癌的可行性及机制。方法将一定浓度梯度的As2O3与人肝癌细胞株SMMC-7721孵育后,采用MTT法、荧光显微镜及流式细胞仪检测细胞增殖与凋亡变化,逆转录聚合酶链反应（RT-PCR）检测肝癌细胞株中骨桥蛋白基因（OPN mRNA）表达水平。结果As2O3作用后SMMC-7721细胞生长明显受抑,且呈时间-浓度依赖性;荧光显微镜下细胞呈典型的凋亡形态学改变;在流式细胞仪上可见“凋亡峰”,细胞周期阻滞于G2／M期;细胞OPN mRNA表达阳性,OPN mRNA表达水平明显下调。结论As2O3体外能有效抑制肝癌细胞株生长;其机制可能为诱导细胞凋亡、下调OPN mRNA表达。     

曲古霉素A对人胃癌细胞的抑制作用及其机制探讨

背景：组蛋白去乙酰基酶抑制剂（HDACi）是一类新型抗肿瘤药物。曲古霉素A（TSA）是目前研究最为广泛的HDACi之一,已发现其对多种肿瘤细胞具有明显抑制作用,但关于TSA对胃癌作用的研究尚少。目的：观察TSA对人胃癌细胞增殖、凋亡、细胞周期以及相关基因表达的影响,探讨其抑制人胃癌细胞的可能作用机制。方法：以不同浓度TSA（0—1μmol／L）处理人胃癌细胞株AGS和HGC-27。CCK-8实验检测细胞增殖抑制情况,流式细胞术检测细胞凋亡和细胞周期,realtimeRT-PCR和蛋白质印迹法检测细胞凋亡、细胞周期相关基因mRNA和蛋白水平的表达。结果：TSA能剂量依赖性地抑制AGS、HGC-27细胞增殖（P=0．000）,对两者的半数致死浓度分别约为0．25μmol／L和0．5μmol／L。TSA能诱导AGS、HGC-27细胞发生G0／G1期和G2／M期阻滞,以G0／G11期阻滞更为明显。TSA对AGS细胞的诱导凋亡作用强于HGC-27细胞（P〈0．05）。TSA尚能上调p21、p53、BaxmRNA和蛋白表达,下调Bel-2、CDK2、cyelinD1mRNA和蛋白表达,作用均呈时间依赖性（P〈0．05）。结论：TSA抑制人胃癌细胞增殖、诱导细胞凋亡的作用可能是通过调节细胞凋亡、细胞周期相关分子、激活多种肿瘤相关信号通路实现的。     

hergl基因调控慢性髓细胞白血病细胞的增殖和细胞周期

目的：研究hergl基因在慢性髓细胞白血病（CML）细胞的表达及其对CML细胞增殖和细胞周期的调控作用。方法：应用RT-PCR方法测定33例初治慢性髓细胞白血病患者和10例健康志愿者的骨髓细胞hergl基因的表达，检测特异性抑制剂处理后CML细胞株K562增殖凋亡和细胞周期的变化。结果：①在初发CML病例中，hergl mRNA的表达率是72．7％（24／33），高于正常对照（20％）（P〈0．01）。CML加速期和急变期的hergl mRNA的表达率分别为75％和90．9％，高于正常对照（P〈O．01），但是hergl的表达与CML的临床分期并无相关性（P〉0．05）。②E-4031（1μmol／L）可呈时间依赖性抑制细胞增殖，不诱导明显凋亡。③E-4031阻滞K562细胞周期于G1期。结论：CML细胞hergl基因表达失调IHERG抑制剂E-4031对K562细胞的增殖和细胞周期具有调控作用，hergl基因可能与CML发病机制相关。     

三氧化二砷体外对人卵巢上皮癌细胞3AO增殖及凋亡的影响

目的　探讨三氧化二砷 (As2 O3 )体外对人卵巢上皮癌细胞株 3AO增殖和凋亡的影响及其作用机制。方法　将人卵巢上皮癌细胞株 3AO与不同浓度的As2 O3 进行体外培养 ,采用四甲基偶氮唑蓝(MTT)测定不同浓度As2 O3 对 3AO细胞的生长抑制率 ,采用流式细胞技术检测细胞凋亡率、细胞周期时相及其Fas、FasL、P53 和bcl 2蛋白的表达。结果　 0 2 5～ 8 0 μmol /L浓度的As2 O3 均显著抑制3AO细胞的增殖 ,且随浓度升高及作用时间的延长 ,抑制率上升 ,As2 O3 与 3AO细胞联合培养 4 8小时的半数致死量 (IC50 )为 (3 90± 0 2 0 ) μmol /L。 0 2 5～ 4 0 μmol /L浓度的As2 O3 均诱导 3AO细胞凋亡 ,随浓度升高 ,凋亡率上升。As2 O3 阻滞 3AO细胞停滞于S期 ,并诱导细胞凋亡。As2 O3 (2 μmol/L )培养3AO细胞 4 8小时 ,Fas蛋白表达率为 (4 6 76± 4 5 0 ) % ,明显高于对照组的 (6 36± 0 82 ) % ,差异有显著性(P <0 0 5 ) ,FasL、P53 和bcl 2蛋白表达无明显变化 (P >0 0 5 )。结论　As2 O3 以剂量 时间依赖性方式抑制人卵巢上皮癌细胞 3AO增殖并诱导其凋亡 ,其作用机制与上调Fas基因表达有关。     

三氧化二砷对肝癌细胞表达PTTG1和VEGF的影响及其意义

目的 观察三氧化二砷(As2O3)对人肝癌细胞株BEL-7402和SMMC-7721的作用及其可能机制.方法 采用四甲基偶氮唑蓝(MTT)法检测As2O3对两种细胞的生长活性;用流式细胞仪测定经不同浓度As2O3溶液处理后的两种细胞的周期变化,并用Annexin V-FITC与PI双染法检测细胞凋亡;用实时逆转录-聚合酶链反应(RT-PCR)检测As2O3对两种细胞垂体肿瘤转化基因1(PTTG1)和血管内皮生长因子(VEGF)mRNA表达的影响;用蛋白免疫印迹法(western-blotting)检测As2O3对两种细胞PTTG1和VEGF蛋白表达的影响.结果 As2O3可显著抑制BEL-7402和SMMC-7721细胞的生长,并呈量效关系(r=0.973,P<0.01;r=0.985,P<0.01),半数抑制浓度(IC50)分别为4.38 μmol/L和5.16 μmol/L.BEL-7402和SMMC-7721经As2O3处理后均发生显著凋亡(P<0.01).As2O3能显著下调两种细胞PTTG1和VEGF mRNA及蛋白的表达(P<0.01),并使细胞周期阻滞在G2/M期.结论 As2O3可有效抑制人肝癌细胞的生长增殖,其机制可能与诱导细胞凋亡、阻滞细胞周期及下调PTTG1和VEGF的表达有关.     

三氧化二砷对人恶性黑素瘤细胞株A375生长和凋亡影响的研究

目的研究三氧化二砷（As2O3）对人恶性黑素瘤细胞株A375的生长抑制与促凋亡作用。方法采用四甲基偶氮唑蓝（MTT）还原法检测As2O3对黑素瘤细胞的抑制作用；倒置显微镜、电镜观察细胞形态变化和凋亡特征；流式细胞仪分析DNA含量和检测细胞周期。结果1．0、2．0、4．0、8．0、16．0μmol／L As2O3均能抑制A375细胞的生长，且抑制率具有浓度和时间依赖性。8．0和16．0μmol／L组主要表现细胞毒性作用；4．0μmol／L组作用72h后，A375细胞出现较典型的凋亡形态特征，流式细胞仪检测到亚二倍体凋亡峰，同时出现S期阻滞。结论As2O3能有效的抑制人恶性黑素瘤细胞株A375的生长并促进其凋亡。     

白藜芦醇对白血病K562细胞增殖、凋亡的影响及机制探讨

目的 探讨白藜芦醇对白血病K562细胞生长的影响及相关作用机制.方法 用不同浓度白藜芦醇作用于K562细胞,CCK-8法观察白藜芦醇对K562细胞生长增殖的影响,AnnexinV-FITC/PI双染法观察白藜芦醇对K562细胞凋亡的影响,PI染色法观察白藜芦醇对K562细胞周期的影响,Western blot法检测K562细胞中的Bcl-2、Bcl-xl、Bax、Cyclin D1蛋白.结果 白藜芦醇作用后的K562细胞的增殖被抑制并且凋亡增加,呈时间-剂量依赖性;同时,凋亡相关分子Bcl-2、Bcl-xl表达下调,Bax表达上调;白藜芦醇作用K562细胞后,G1期细胞增多,S期细胞减少,细胞周期调节蛋白Cyclin D1表达下降.结论 白藜芦醇可抑制K562细胞增殖并诱导其凋亡,其机制可能与下调细胞内Bcl-2、Bcl-xl、Cyclin D1表达并上调Bax的表达有关.     

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.