檞皮素抑制人脑胶质瘤SHG-44细胞增殖的实验研究

目的探讨中草药檞皮素抑制人胶质瘤SHG-44细胞的增殖作用。方法运用MTT法检测檞皮素对SHG-44细胞增殖的抑制作用,流式细胞仪技术分析檞皮素对SHG-44细胞增殖周期的影响。结果50～200μmol/L浓度的檞皮素均能抑制SHG-44细胞的生长,且呈明显的时间,剂量依赖性关系,细胞周期分析显示檞皮素组G1期细胞比例明显增多,呈量效关系。结论檞皮素抑制SHG-44细胞增殖,可能通过使SHG-44细胞停滞在G1期而诱导其凋亡。     

蛋白酶体抑制剂Bortezomib对人脑胶质瘤增殖抑制及诱导凋亡作用

目的 探讨Bortezomib对体外SHG-44胶质瘤细胞株形态的影响及诱导凋亡作用.方法 Bortezomib体外处理培养的SHG-44胶质瘤细胞后,采用MTT法检测细胞增殖、HE染色光镜观察、Hochest33342染色荧光显微镜观察以及锇铀铅染色透射电镜观察胶质瘤细胞的形态变化,流式细胞术分析细胞凋亡率及细胞周期.结果 MTT显示Bortezomib抑制SHG-44胶质瘤的增殖与浓度和时间呈相关性;6.0 μmol/L Bortezomib处理SHG-44胶质瘤细胞24 h后,光镜、荧光显微镜、透射电镜下均可见凋亡形态学改变.流式细胞术分析细胞凋亡率为(20.31±2.84)% ( P＜0.01);细胞周期变化显示S期细胞减少到(17.65±6.38)% (P＜0.01),细胞周期被阻滞于G_0/G_1期和G_2/M期,分别为(68.51±5.62) % (P＜0.01)和(14.75±2.48)% (P＜0.01).结论 Bortezomib抑制C6胶质瘤细胞的增殖并诱导其凋亡.     

紫杉醇对胶质瘤SHG-44细胞的增殖抑制和辐射增敏作用

目的观察紫杉醇对胶质瘤SHG-44细胞的抑制及放射增敏作用,并探讨其作用机制。方法不同浓度紫杉醇(0、0.062 5、1.25、2.5、5和10μg/mL)作用于SHG-44细胞,MTT法检测紫杉醇对SHG-44细胞的增殖抑制作用;克隆形成法检测细胞辐射敏感性变化,流式细胞术检测细胞凋亡百分率变化。结果紫杉醇有明显的抑制SHG-44细胞增殖和提高其放射敏感性的作用,紫杉醇可提高3、6 Gy照射24 h后SHG-44细胞的凋亡率。结论紫杉醇对人胶质瘤SHG-44细胞具有杀伤及放射增敏作用。其可能机制是加强射线对肿瘤细胞的诱导凋亡效应,增强其杀伤肿瘤作用。     

姜黄素对人脑胶质瘤SHG-44细胞抑制及凋亡的实验研究

目的探讨姜黄素（erueumin）对人脑胶质瘤SHG-44细胞体外抑制及凋亡调控作用。方法20-80μmol／L姜黄素分别处理SHG-44细胞48h后，MTT法测定姜黄素对SHG-44细胞的细胞抑制作用及各种caspase抑制剂对姜黄素作用的影响；通过流式细胞仪AnnexinV—FITC／PI凋亡检测试剂盒检测细胞凋亡；透射电镜观察细胞形态学变化；荧光分光光度法检测easpase-3活性的改变。结果姜黄素明显抑制SHG-44细胞的增殖；诱导SHG-44细胞凋亡；caspase-3活性增强，各种caspase抑制剂可抑制姜黄素诱导的SHG-44细胞凋亡。结论姜黄素可明显抑制并诱导SHG-44细胞凋亡。     

榄香烯聚氰基丙烯酸正丁酯纳米粒子对SHG-44脑胶质瘤的抑制作用

目的探究榄香烯聚氰基丙烯酸正丁酯纳米粒子(Gd-PBCA-NP)对SHG-44脑胶质瘤的抑制作用。方法提取大鼠的脑胶质瘤细胞SHG-44,并对其进行体外培养实验,将这些脑胶质瘤细胞SHG-44按照随机的原则分为干预组与对照组,对照组为空白,干预组则严格按照Gd-PBCA-NP浓度进行分组,然后采用MTT比色法,对榄香烯不同浓度体外培养下的脑胶质瘤细胞SHG-44的抑制作用给予有效的检测,然后借助流式细胞仪测定干预组的脑胶质瘤细胞SHG-44中的细胞凋亡情况。结果榄香烯的浓度不同,其对SHG-44脑胶质瘤体的抑制作用也有着一定的区别。10.0 mol/L浓度的Gd-PBCA-NP对SHG-44脑胶质瘤的抑制作用明显优于2.50 mol/L浓度,且干预组的脑胶质瘤细胞SHG-44的存活率明显低于对照组(P0.05);Gd-PBCA-NP浓度越高,其对脑胶质瘤细胞SHG-44的抑制作用就越强。结论 Gd-PBCA-NP对SHG-44脑胶质瘤有着明显的抑制作用,能够在一定程度上抑制脑胶质瘤SHG-44细胞的凋亡与增殖,而且能够增强细胞抗肿瘤活性,具有一定的安全性。     

蛋白酶体抑制剂对肾间质成纤维细胞凋亡和增殖的影响

目的:探讨泛素蛋白酶体抑制剂MG-132对大鼠肾间质成纤维细胞(NRK-49F)及其在转化生长因子β1(TGF-β1)诱导下的细胞凋亡和增殖情况,并初步探索其机制。方法:采用5ng/ml的TGF-β1作用于NRK-49F,不同浓度(0~5μM)的蛋白酶体抑制剂MG-132预处理NRK-49F细胞,应用MTT法检测其增殖情况,LDH法检测细胞毒性,应用流式细胞仪检测细胞周期和细胞凋亡率,Hoechst 33258染色观察细胞凋亡形态学变化,Western blot检测p-IκB,IκB蛋白的变化。结果:TGF-β1(5ng/ml)能促进NRK-49F的增殖(0.661±0.04vs0.495±0.06),MG-132(0.25~5μM)呈剂量依赖型抑制这种效应;MG-132(0.1~5μM)对NRK-49F有一定的细胞毒性作用,在0.5μM时达高峰;TGF-β1单独不能促使NRK-49F的凋亡[(3.8±0.4)%vs(4.7±1.6)%],但加用MG-132(0.1~2.5μM)干预后呈剂量依赖关系促进细胞凋亡,MG-132单独也有促进细胞凋亡作用;MG-132(0~1μM)作用于TGF-β1诱导的NRK-49F后,其S期比例呈剂量依赖关系显著减少,G1期细胞比例增加;Hoechst 33258染色显示MG-132(0.5μM) TGF-β1组及MG-132组细胞核均出现核固缩、核碎裂、凋亡小体等凋亡特异形态学改变;Western blot结果显示,TGF-β1及MG-132(2.5μM) TGF-β1均能以时间依赖方式诱导p-IκB、IκB蛋白表达增加,且MG-132能上调TGF-β1诱导下的p-IκB,IκB蛋白表达。结论:泛素蛋白酶体抑制剂MG-132对正常及病理状态下的NRK-49F都有促凋亡作用,并可能通过G1期阻滞过程来抑制其增殖作用。其机制可能与MG-132阻断IκB蛋白的泛素化降解有关。     

RNAi沉默survivin基因对胰腺癌细胞增殖、凋亡和周期的影响

目的 应用RNAi技术沉默胰腺癌细胞株中survivin基因对肿瘤细胞凋亡、细胞周期和增殖的变化.方法 靶向survivin的RNAi载体转染胰腺癌细胞,Western印迹检测基因沉默效果,MTT法和流式细胞术检测细胞增殖、凋亡及细胞周期.结果 survivin基因沉默效率可达85%;MTT检测显示,干扰组survivin沉默细胞增殖抑制与非特异性质粒对照组相比显著增高(P<0.01).流式细胞术显示,干扰组细胞凋亡百分率显著高于非特异性质粒对照组(P<0.01);G_2/M期显著高于非特异性质粒对照组(P<0.01或P<0.05),而S期则显著降低(P<0.05).结论 survivin基因沉默可引起胰腺癌细胞周期阻滞,促进细胞凋亡,抑制细胞增殖.     

五味子粗多糖与顺铂抑制脑胶质瘤细胞增殖的作用

目的研究五味子粗多糖(FSP)单独或与顺铂联合抑制脑胶质瘤细胞增殖的作用。方法培养脑胶质瘤(SHG-44)细胞,应用四甲基偶氮唑(MTT)法检测FSP单独及联合顺铂抑制细胞增殖的情况。结果脑胶质瘤SHG-44细胞在FSP浓度200、400、800μg/ml时,均可以抑制细胞的增殖(P<0.05或P<0.01),且有浓度依赖性。FSP与顺铂联合作用时可以明显地抑制细胞的生长(P<0.01)。结论 FSP可以抑制胶质瘤SHG-44细胞的增殖,联合顺铂时可发挥协同作用。     

MG-132抑制大鼠缺血再灌注心肌细胞凋亡

目的观察蛋白酶体抑制剂MG-132对急性缺血再灌注大鼠心肌细胞凋亡的影响。方法建立大鼠心肌缺血再灌注模型,治疗组及治疗对照组于再灌注前5min静脉注射MG-132(0.75mg/kg),缺血再灌注组及假手术组注射生理盐水,观察各组心肌组织炎症细胞浸润及心肌细胞凋亡情况。结果MG-132能显著抑制心肌梗死周围组织嗜中性粒细胞的浸润;与缺血再灌注组相比,治疗组核因子κBmRNA水平和蛋白水平显著降低(P<0.05);治疗组再灌注2h、6h及24h亚组凋亡指数较缺血再灌注组同时间点显著下降;与缺血再灌注组相比,Bax的积分光密度值降低(P<0.05),Bcl-2蛋白水平明显上调,Bcl-2/Bax比值显著增加。结论蛋白酶体抑制剂能够抑制急性缺血再灌注心肌的凋亡,具有心肌保护作用。     

地喹氯铵对脑胶质瘤细胞凋亡的影响

目的探讨地喹氯铵对脑胶质瘤细胞增殖、凋亡及侵袭的影响。方法用50、100、200μmol/L的地喹氯铵作用于脑胶质瘤细胞U251、U87、C6,作用时间分别为12、24、48、72、96 h,MTT检测细胞增殖情况。流式细胞仪检测76μmol/L的地喹氯铵作用48 h后的脑胶质瘤细胞U251的细胞凋亡情况。Transwell小室检测地喹氯铵对脑胶质瘤细胞侵袭能力的影响。Western印迹检测细胞中PI3K、p-PI3K、Akt、p-Akt蛋白的表达水平。结果 50、100、200μmol/L的地喹氯铵对U251、U87、C6脑胶质瘤细胞增殖均具有抑制作用。地喹氯铵对脑胶质瘤细胞的增殖抑制作用随着作用时间的增加而增加,随着药物作用浓度的增加而增加。地喹氯铵作用胶质瘤U251、U87、C6细胞48 h的半数抑制浓度由大到小依次为:C6>U87>U251。76μmol/L的地喹氯铵作用后的脑胶质瘤细胞凋亡率明显高于对照组(P<0.01)。脑胶质瘤细胞经地喹氯铵作用后的侵袭细胞数明显低于对照组(P<0.01)。地喹氯铵作用后的脑胶质瘤细胞中PI3K、Akt的表达水平与对照组相比无明显差异,而p-PI3K、p-Akt的表达水平明显下降。结论地喹氯铵对脑胶质瘤细胞增殖、侵袭能力具有抑制作用,对脑胶质瘤细胞凋亡具有促进作用,作用机制与PI3K/Akt信号通路有关。     

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.