• 【interleukin-1 α 诱导的黑色素瘤细胞运动的表征: I型和II型受体阻断单克隆抗体的抑制。】 复制标题 收藏 收藏
    DOI:10.1097/00008390-199706000-00006 复制DOI
    作者列表:Dekker SK,Vink J,Bruijn JA,Mihm MC Jr,Vermeer BJ,Byers HR
    BACKGROUND & AIMS: Interleukin-1 alpha (IL-1 alpha) induces cell motility in a variety of benign cell types and in some but not all malignant cell lines in vitro. This study characterizes the IL-1 alpha-induced motility of an aggressive human melanoma cell line that expresses both type I and type II IL-1 receptors. We tested the effect of monoclonal antibodies including function-blocking moAbs against the type I and type II IL-1 receptors on melanoma cell motility to determine which receptor is involved in signal transduction of IL-1 alpha-induced melanoma cell motility. IL-1 alpha significantly increases MM-RU melanoma cell migration in a dose-dependent manner using modified Boyden chamber assays at concentrations 10 to 100 times less than concentrations that significantly inhibit cell growth. Computer-assisted time-lapse image analysis reveals that the motility is inhibited in a dose-dependent manner by neutralizing antibodies against IL-1 alpha. Function-blocking monoclonal antibodies against either type I or type II IL-1 receptors show a significant inhibition of cytokine-induced enhanced cell migration. When both the anti-IL-1 receptor antibodies are added together, the motility-response is completely blocked to control levels. Taken together the data indicate that the IL-1 alpha-induced motility of MM-RU melanoma cells is mediated through both type I and type II IL-1 receptors. The significant inhibition of motility by neutralizing IL-1 alpha or blocking either one or both of the IL-1 receptors indicates an integration of IL-1-induced signals in the induction of melanoma cell migration.

    背景与目标: Interleukin-1 α (IL-1 α) 在体外诱导多种良性细胞类型和一些但不是全部恶性细胞系中的细胞运动。这项研究表征了表达I型和II型IL-1受体的侵袭性人类黑素瘤细胞系的IL-1 α 诱导的运动。我们测试了单克隆抗体 (包括针对I型和II型IL-1受体的功能阻断moab) 对黑色素瘤细胞运动的影响,以确定哪种受体参与IL-1 α 诱导的黑色素瘤细胞运动的信号转导。IL-1 α 以剂量依赖的方式显著增加MM-RU黑素瘤细胞迁移,使用改进的Boyden室测定法,浓度低于显著抑制细胞生长的浓度的10至100倍。计算机辅助延时图像分析表明,通过中和针对IL-1 α 的抗体,运动性以剂量依赖的方式受到抑制。针对I型或II型IL-1受体的功能阻断单克隆抗体显示出对细胞因子诱导的增强细胞迁移的显着抑制。当两种anti-IL-1受体抗体加在一起时,运动反应完全阻断到控制水平。总之,这些数据表明,IL-1 α 诱导的MM-RU黑素瘤细胞的运动是通过I型和II型IL-1受体介导的。通过中和IL-1 α 或阻断一种或两种IL-1受体而显着抑制运动,表明IL-1-induced信号在诱导黑色素瘤细胞迁移中的整合。
  • 【垂体切除术前后垂体依赖性高肾上腺皮质激素,皮质醇,α-黑素细胞刺激激素和生长激素的血浆谱。】 复制标题 收藏 收藏
    DOI:10.1677/joe.1.06782 复制DOI
    作者列表:Hanson JM,Kooistra HS,Mol JA,Teske E,Meij BP
    BACKGROUND & AIMS: :The 6-h plasma profiles of adrenocorticotropic hormone (ACTH), cortisol, alpha-melanocyte-stimulating hormone (alpha-MSH), and GH were studied in 17 dogs with pituitary-dependent hyperadrenocorticism (PDH) before and after hypophysectomy. The aim of the study was to investigate the relation between the hormone profile characteristics and recurrence of PDH after surgery. The hormones were secreted in a pulsatile fashion. The basal plasma cortisol concentration and area under the curve (AUC) for cortisol were significantly higher in the PDH cases than in eight controls. The characteristics of the plasma profiles of ACTH and alpha-MSH were not significantly different between the PDH cases and the controls. In the PDH cases, less GH was secreted in pulses than in the controls, but the difference was not significant. The basal plasma cortisol concentration, the AUC for ACTH and cortisol, and the pulse frequency of ACTH and cortisol decreased significantly after hypophysectomy for the group of PDH cases. The basal plasma concentrations of ACTH and alpha-MSH, the AUC for alpha-MSH, and the characteristics of the plasma GH profiles of the PDH cases remained unchanged after hypophysectomy. No pulses of alpha-MSH were observed after hypophysectomy. The co-occurrence between the ACTH and cortisol pulses decreased significantly with hypophysectomy. The postoperative pulse frequency of ACTH was the only characteristic with predictive value for the recurrence of PDH after hypophysectomy. The results of this study demonstrate that ACTH, cortisol, alpha-MSH, and GH are secreted in a pulsatile fashion in dogs with PDH. Hypophysectomy effectively reduces the secretion of ACTH and cortisol. The presence of ACTH pulses after hypophysectomy is a risk factor for the recurrence of hyperadrenocorticism.
    背景与目标: : 在17只垂体切除术前后,研究了促肾上腺皮质激素 (ACTH),皮质醇,α-黑素细胞刺激激素 (alpha-MSH) 和GH的6小时血浆谱。该研究的目的是研究PDH术后激素特征与复发之间的关系。荷尔蒙以脉动的方式分泌。PDH病例的基础血浆皮质醇浓度和皮质醇曲线下面积 (AUC) 显着高于八个对照。在PDH病例和对照组之间,ACTH和 α-MSH的血浆特征没有显着差异。在PDH病例中,脉冲分泌的GH比对照组少,但差异不显着。PDH组患者垂体切除术后,基础血浆皮质醇浓度,ACTH和皮质醇的AUC以及ACTH和皮质醇的脉冲频率显着降低。垂体切除术后,PDH病例的基础血浆ACTH和 α-MSH的血浆浓度,α-MSH的AUC以及血浆GH谱的特征保持不变。垂体切除术后未观察到 α-MSH脉冲。垂体切除术后,ACTH和皮质醇脉冲之间的共存显着减少。ACTH的术后脉搏频率是垂体切除术后PDH复发的唯一特征,具有预测价值。这项研究的结果表明,患有PDH的狗以脉动方式分泌ACTH,皮质醇,α-MSH和GH。垂体切除术有效地减少了ACTH和皮质醇的分泌。垂体切除术后ACTH脉冲的存在是肾上腺皮质亢进症复发的危险因素。
  • 【山羊 α-乳白蛋白中单个Trp残基的荧光贡献。】 复制标题 收藏 收藏
    DOI:10.1016/j.bbapap.2006.07.011 复制DOI
    作者列表:Vanhooren A,Illyes E,Majer Z,Hanssens I
    BACKGROUND & AIMS: :Goat alpha-lactalbumin (GLA) contains four tryptophan (Trp) residues. In order to obtain information on the fluorescence contribution of the individual Trp residues in native GLA, we recorded the fluorescence spectra of four GLA mutants, W26F, W60F, W104F, and W118F, in each of which a single Trp residue was replaced with phenylalanine (Phe). Comparison of the fluorescence spectra of the four mutants with that of wild-type GLA indicated that, in native GLA, three Trp residues (Trp60, Trp104, and Trp118) are strongly quenched and account for the partial indirect quenching of Trp26. As a consequence, the fluorescence of wild-type GLA and of the mutants W60F, W104F, and W118F mainly results from Trp26. An inspection of the crystal structure indicated that, in addition to the disulfide bonds that are in direct contact with the indole groups of Trp60 and Trp118, backbone peptide bonds that are in direct contact with the indole groups of Trp60, Trp104, and Trp118, contribute to the direct quenching effects. Interestingly, the lack of direct quenching of Trp26 explains why the cleavage of disulfide bonds by UV light is mediated more by the highly fluorescent Trp26 than by the less fluorescent Trp104 and Trp118.
    背景与目标: : 山羊 α-乳白蛋白 (GLA) 含有四个色氨酸 (Trp) 残基。为了获得有关天然GLA中单个Trp残基的荧光贡献的信息,我们记录了四个GLA突变体W26F,W60F,W104F和W118F的荧光光谱,其中每个单个Trp残基被替换为苯丙氨酸 (Phe)。将四个突变体的荧光光谱与野生型GLA的荧光光谱进行比较表明,在天然GLA中,三个Trp残基 (Trp60,Trp104和Trp118) 被强烈淬灭,并解释了trp26的部分间接猝灭。因此,野生型GLA和突变体W60F,W104F和W118F的荧光主要来自trp26。对晶体结构的检查表明,除了与Trp60和Trp118的吲哚基团直接接触的二硫键外,与Trp60,Trp104和Trp118的吲哚基团直接接触的骨架肽键有助于直接猝灭作用。有趣的是,缺乏Trp26的直接猝灭解释了为什么高荧光的Trp26比低荧光的Trp104和trp118更多地介导紫外光对二硫键的裂解。
  • 【根据哌唑嗪的亲和力,人类良性前列腺肥大组织中的 α-1肾上腺素受体亚型 (高,低)。】 复制标题 收藏 收藏
    DOI:10.1002/(sici)1097-0045(19970601)31:4<216::aid-pro 复制DOI
    作者列表:Takeda M,Hatano A,Komeyama T,Koizumi T,Mizusawa T,Kanai T,Tomita Y,Maruyama K,Nagatomo T
    BACKGROUND & AIMS: BACKGROUND:A novel classification of alpha-1 adrenoceptor subtypes (High, Low) was applied to human benign prostatic hypertrophy (BPH) tissue. METHODS:Human BPH specimens were examined by a radioligand binding assay method using 3H-prazosin, and those data were compared with preoperative therapies. RESULTS:(1) Scatchard analysis showed a high-affinity site (Kd:27.18 +/- 6.41 pM; Bmax:9.29 +/- 0.98 fM/mg protein; mean +/- SE) as alpha 1H, and a low-affinity site (Kd: 4088.0 +/- 744.34 pM, Bmax: 140.81 +/- 19.98 fM/mg protein) as alpha 1L subtype, for prazosin. (2) The Kd and Bmax were not different in the nontreated group (n = 5), alpha 1 blocker group (n = 5), and antiandrogen group (n = 5), in either alpha 1-high affinity or alpha 1-low affinity subtype. (3) Phenoxybenzamine had different pKi values for the above two adrenoceptor subtypes. Scatchard analysis showed that alpha 1-high affinity binding site disappeared in the presence of 1 microM of phenoxybenzamine, and the Kd and Bmax values in the presence of 1 microM of phenoxybenzamine were almost identical to the alpha 1-low affinity site of the two subtypes. CONCLUSIONS:Human BPH tissue possesses both alpha 1H- and alpha 1L-adrenoceptor subtypes according to the affinities for prazosin, and only the alpha 1H subtype can be completely inhibited by some concentration of phenoxybenzamine. Treatment by alpha 1 blocker may not change the conditions of alpha 1-adrenoceptors in prostatic tissue.
    背景与目标:
  • 【产气荚膜梭菌的 α 毒素不是鸡坏死性肠炎的必需毒力因子。】 复制标题 收藏 收藏
    DOI:10.1128/IAI.00806-06 复制DOI
    作者列表:Keyburn AL,Sheedy SA,Ford ME,Williamson MM,Awad MM,Rood JI,Moore RJ
    BACKGROUND & AIMS: :The Clostridium perfringens alpha-toxin has previously been implicated as the major virulence factor in necrotic enteritis in chickens, although definitive proof has not been reported. In this study an alpha-toxin mutant was constructed in a virulent chicken isolate and shown to retain full virulence in a chicken disease model. These results demonstrated that alpha-toxin is not an essential virulence factor in the pathogenesis of necrotic enteritis in chickens.
    背景与目标: : 尽管尚未报道明确的证据,但以前曾将产气荚膜梭菌 α 毒素作为鸡坏死性肠炎的主要毒力因子。在这项研究中,在强毒鸡分离株中构建了一个 α 毒素突变体,并显示在鸡疾病模型中保留了完全的毒力。这些结果表明,在鸡坏死性肠炎的发病机理中,α-毒素不是必需的毒力因子。
  • 【鸽子中两个 α-珠蛋白基因 α (A) 和 α (D) 隔离和测序以及 α (D)-珠蛋白基因胚胎特异性表达的证据。】 复制标题 收藏 收藏
    DOI:10.1006/bbrc.1997.6667 复制DOI
    作者列表:Ikehara T,Eguchi Y,Kayo S,Takei H
    BACKGROUND & AIMS: :By screening a pigeon genomic DNA library, we isolated a recombinant phage clone containing the alpha(A)-globin gene. The DNA sequence of the approximately 6kbp-long insert fragment of the phage clone was determined. The sequence suggested the existence of pigeon alpha(D)-globin gene located 3.1 kbp upstream from the alpha(A)-globin gene. The expression of the alpha(D)-globin in late embryo was also shown by the N-terminal amino-acid sequence of the intact globin chain. These results show that two adult alpha-globin genes, alpha(A) and alpha(D), exist in the pigeon genome, and the alpha(D)-globin is expressed at the late embryo stage. The stage-specific expression suggests the existence of regulatory elements and factors interacting to inhibit transcription at the adult stage.
    背景与目标: : 通过筛选鸽子基因组DNA文库,我们分离出含有 α (a)-珠蛋白基因的重组噬菌体克隆。确定了噬菌体克隆的约6kbp长的插入片段的DNA序列。该序列表明存在位于 α (A)-珠蛋白基因上游3.1 kbp的鸽子 α (D)-珠蛋白基因。完整珠蛋白链的N端氨基酸序列也显示了 α (D)-珠蛋白在晚期胚胎中的表达。这些结果表明,鸽子基因组中存在两个成年的 α-珠蛋白基因 α (A) 和 α (D),并且 α (D)-珠蛋白在胚胎晚期表达。阶段特异性表达表明存在调节元件和因子相互作用以抑制成年阶段的转录。
  • 【二硝基苯胺与apicomplexan和运动质体 α-微管蛋白的结合和相互作用。】 复制标题 收藏 收藏
    DOI:10.1021/jm060472+ 复制DOI
    作者列表:Mitra A,Sept D
    BACKGROUND & AIMS: :Despite years of use as commercial herbicides, it is still unclear how dinitroanilines interact with tubulin, how they cause microtubule disassembly, and why they are selectively active against plant and protozoan tubulin. In this work, through a series of computational studies, a common binding site of oryzalin, trifluralin, and GB-II-5 on apicomplexan and kinetoplastid alpha-tubulin is proposed. Furthermore, to investigate how dinitroanilines affect tubulin dynamics, molecular dynamics simulations of Leishmania alpha-tubulin with and without a bound dinitroaniline are performed. The results obtained provide insight into the molecular mechanism by which these compounds interact with tubulin and function to prevent microtubule assembly. Finally, to aid in the design of effective parasitic microtubule inhibitors, several novel dinitroaniline analogues are evaluated. The location of the binding site and the relative binding affinities of the dinitroanilines all agree well with experimental data.
    背景与目标: : 尽管已作为商业除草剂使用多年,但仍不清楚二硝基苯胺如何与微管蛋白相互作用,它们如何引起微管分解,以及为什么它们对植物和原生动物的微管蛋白具有选择性活性。在这项工作中,通过一系列计算研究,提出了米唑林,三氟拉林和GB-II-5在apicomplexan和动质体 α-微管蛋白上的共同结合位点。此外,为了研究二硝基苯胺如何影响微管蛋白动力学,对有和没有结合的二硝基苯胺的利什曼原虫 α-微管蛋白进行了分子动力学模拟。获得的结果提供了对这些化合物与微管蛋白相互作用并阻止微管组装的分子机制的深入了解。最后,为了帮助设计有效的寄生微管抑制剂,评估了几种新型的二硝基苯胺类似物。结合位点的位置和二硝基苯胺的相对结合亲和力都与实验数据吻合良好。
  • 【干扰素 α2b与达卡巴嗪,卡莫司汀,顺铂和他莫昔芬在转移性黑色素瘤中的II期研究。】 复制标题 收藏 收藏
    DOI:10.1097/00008390-199704000-00009 复制DOI
    作者列表:Schultz MZ,Buzaid AC,Poo WJ
    BACKGROUND & AIMS: A phase II trial was conducted to determine the efficacy and toxicity of the addition of interferon-alpha 2b (IFN-alpha) to the chemotherapy combination of dacarbazine (DTIC), carmustine (BCNU), cisplatin and tamoxifen (DBCT), in patients with stage III or IV melanoma. Treatment consisted of DTIC 220 mg/m2 and cisplatin 25 mg/m2 intravenously on days 1-3, BCNU 100 mg/m2 IV on day 1 only, tamoxifen 20 mg orally twice daily and IFN-alpha 5 x 10(6) units/m2 subcutaneously on days 1-5. Cycles were repeated every 4 weeks. All patients received a loading dose of tamoxifen 100 mg orally twice daily for 5 days before the first course of therapy. Of the 24 patients treated, three (13%) achieved a complete response (CR) and six (25%) a partial response (PR), for an overall response rate of 38% (95% confidence interval, 17-58%). Two patients, one who achieved a clinical CR and one a PR, had pathologically confirmed complete responses. Severe myelosuppression occurred in 47% of cycles and constitutional symptoms were common. Overall, the addition of IFN-alpha to the DBCT regimen did not appear to enhance the response rate and may have increased toxicity.

    背景与目标: 进行了II期试验,以确定在达卡巴嗪 (DTIC),卡莫司汀 (BCNU),顺铂和他莫昔芬 (DBCT) 的化疗组合中添加干扰素 α2b (IFN-α) 的疗效和毒性。III或IV期黑色素瘤患者。治疗包括在第1-3天静脉注射DTIC 220 mg/m2和顺铂25 mg/m2,仅在第1天静脉注射BCNU 100 mg/m2,他莫昔芬20 mg每天口服两次,在第1-5天皮下注射IFN-α5 × 10(6) 单位/m2。每4周重复一次周期。所有患者接受负荷剂量的他莫昔芬100 mg口服,每日两次,治疗前5天。在接受治疗的24例患者中,3例 (13% 例) 达到完全缓解 (CR),6例 (25% 例) 达到部分缓解 (PR),总缓解率为38% (95% 置信区间17-58%)。两名患者,其中一名获得了临床CR,一名获得了PR,经病理证实完全缓解。严重的骨髓抑制发生在47% 的周期和全身症状是常见的。总体而言,在DBCT方案中添加IFN-α 似乎并未增强反应率,并且可能具有增加的毒性。
  • 【阿尔法节律的阴暗面: 完全黑暗期间诱导阿尔法调制的fMRI证据。】 复制标题 收藏 收藏
    DOI:10.1111/ejn.12083 复制DOI
    作者列表:Ben-Simon E,Podlipsky I,Okon-Singer H,Gruberger M,Cvetkovic D,Intrator N,Hendler T
    BACKGROUND & AIMS: :The unique role of the EEG alpha rhythm in different states of cortical activity is still debated. The main theories regarding alpha function posit either sensory processing or attention allocation as the main processes governing its modulation. Closing and opening eyes, a well-known manipulation of the alpha rhythm, could be regarded as attention allocation from inward to outward focus though during light is also accompanied by visual change. To disentangle the effects of attention allocation and sensory visual input on alpha modulation, 14 healthy subjects were asked to open and close their eyes during conditions of light and of complete darkness while simultaneous recordings of EEG and fMRI were acquired. Thus, during complete darkness the eyes-open condition is not related to visual input but only to attention allocation, allowing direct examination of its role in alpha modulation. A data-driven ridge regression classifier was applied to the EEG data in order to ascertain the contribution of the alpha rhythm to eyes-open/eyes-closed inference in both lighting conditions. Classifier results revealed significant alpha contribution during both light and dark conditions, suggesting that alpha rhythm modulation is closely linked to the change in the direction of attention regardless of the presence of visual sensory input. Furthermore, fMRI activation maps derived from an alpha modulation time-course during the complete darkness condition exhibited a right frontal cortical network associated with attention allocation. These findings support the importance of top-down processes such as attention allocation to alpha rhythm modulation, possibly as a prerequisite to its known bottom-up processing of sensory input.
    背景与目标: : EEG α 节律在不同皮质活动状态中的独特作用仍存在争议。有关alpha功能的主要理论将感觉处理或注意力分配视为控制其调制的主要过程。关闭和睁开眼睛是一种众所周知的对阿尔法节奏的操纵,尽管在光照过程中也伴随着视觉变化,但可以将注意力从内向向外向分配。为了弄清注意力分配和感觉视觉输入对 α 调制的影响,要求14名健康受试者在光线和完全黑暗的情况下睁开和闭上眼睛,同时同时记录脑电图和功能磁共振成像。因此,在完全黑暗的情况下,睁眼状态与视觉输入无关,而仅与注意力分配有关,从而可以直接检查其在alpha调制中的作用。将数据驱动的山脊回归分类器应用于EEG数据,以确定在两种光照条件下 α 节律对睁眼/闭眼推理的贡献。分类器结果显示,无论在明暗条件下,alpha都有显着贡献,这表明无论是否存在视觉感觉输入,alpha节律调制都与注意方向的变化密切相关。此外,在完全黑暗的条件下,从alpha调制时间过程中得出的fMRI激活图显示出与注意力分配相关的右额叶皮层网络。这些发现支持自上而下的过程的重要性,例如将注意力分配给alpha节奏调制,这可能是其已知的感觉输入自下而上处理的先决条件。
  • 【通过蛋白质组学方法观察到STZ诱导的糖尿病大鼠肾线粒体中alpha-2u球蛋白的下调。】 复制标题 收藏 收藏
    DOI:10.1016/j.ando.2012.09.007 复制DOI
    作者列表:Sun SH,Liu SQ,Cai CP,Cai R,Chen L,Zhang QB
    BACKGROUND & AIMS: AIM:To identify the changes of mitochondrial protein expression in diabetic renal parenchyma and to characterize their molecular functions and biological processes in diabetes. METHODS:Mitochondrial proteins extracted from renal parenchyma mitochondria of streptozotocin-induced diabetic rats and normal rats were separated by two-dimensional polyacrylamide gel electrophoresis and identified by matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry. RESULTS:Eleven proteins from 533 visualized protein spots displayed significant different expressions in mitochondria of diabetic kidneys compared with those in normal ones. Among these altered proteins, two proteins with the most obvious changes in protein expression were identified as alpha-2u globulin (mature protein, named A2) and its proteolytically modified form (named A2-fragment) respectively. These proteins were found in mitochondria of male rat renal parenchyma and were proved to be down-regulated in diabetic rats simultaneously. CONCLUSION:Our results suggest that down-regulation of alpha-2u globulin may be associated with an abnormal β-oxidation of long-chain fatty acids during diabetes. The decreased expression of A2-fragment in renal mitochondria of diabetic nephropathy may reduce fatty acid β-oxidation, which leads to a diminished energy supply from mitochondria to kidney tissue and the deposition of a large number of fatty acids in the kidney, ultimately causing and aggravating kidney damage. In conclusion, these findings may be helpful for understanding the molecular mechanism of diabetic nephropathy.
    背景与目标:
  • 【血清甲胎蛋白的半衰期: 肝细胞癌肝切除术后复发和生存的早期预后指标。】 复制标题 收藏 收藏
    DOI:10.1097/SLA.0b013e318273be70 复制DOI
    作者列表:Shim JH,Han S,Lee YJ,Lee SG,Kim KM,Lim YS,Chung YH,Lee YS,Lee HC
    BACKGROUND & AIMS: OBJECTIVE:To explore the prognostic value of the postsurgical half-life (HL) of serum alpha-fetoprotein (AFP). BACKGROUND:There is still a paucity of early surrogate indicators of clinical endpoints after liver resection of hepatocellular carcinoma (HCC). METHODS:The analysis was based on cohorts of 225 (exploration set) and 117 (validation set) treatment-naïve HCC patients undergoing curative liver resection. We defined 3 categories of AFP HL: early complete resolution of AFP, normal HL, and prolonged HL if the HL exceeded 7 days. Overall, probabilities of recurrence and survival were estimated and compared across the AFP HL categories. RESULTS:In the exploration cohort, 48 patients (21.3%) achieved early AFP complete resolution, 116 (51.6%) had normal HL, and 61 (27.1%) had prolonged HL. Long AFP HL was significantly associated with early postoperative recurrence (P < 0.001), as was microvascular invasion. Early recurrence within 2 years of resection was observed in 59% of the patients with prolonged AFP HL compared with only 29.3% of those with normal AFP HL (P < 0.001). A log-rank test followed by multivariate Cox analysis identified an independent function of prolonged AFP HL in predicting shorter recurrence-free survival and overall survival time after HCC resection (hazard ratios, 2.81 and 3.58; P < 0.001). When AFP HL analysis was applied to the validation cohort, the association between prolonged AFP HL and survival endpoints (hazard ratio, 11.63 and 16.39; P < 0.001) was confirmed.
    背景与目标:
  • 【路易体患者的阿尔茨海默氏病和痴呆症的脑脊液可增强体外 α-突触核蛋白原纤维的形成。】 复制标题 收藏 收藏
    DOI:10.1016/j.expneurol.2006.08.012 复制DOI
    作者列表:Ono K,Noguchi-Shinohara M,Yoshita M,Naiki H,Yamada M
    BACKGROUND & AIMS: :Deposition of alpha-synuclein (alphaS) aggregates inside brain cells is a pathological hallmark of several neurodegenerative diseases, including Parkinson's disease (PD), and dementia with Lewy bodies (DLB). Recently, extracellular alphaS was detected in cerebrospinal fluid (CSF) and plasma of humans. We investigated whether CSF influences alphaS aggregation in vitro using fluorescence spectroscopy with thioflavin S and electron microscopy. We found that CSF obtained from Alzheimer's disease (AD) and DLB patients enhanced the alphaS fibril formation compared with tauopathy and non-central nervous system disease. Thus, CSF of AD and DLB characterized by aggregation of Abeta or alphaS might promote falphaS formation.
    背景与目标: : 脑细胞内 α-突触核蛋白 (alpha) 聚集体的沉积是几种神经退行性疾病的病理标志,包括帕金森氏病 (PD) 和路易体痴呆 (DLB)。最近,在人类的脑脊液 (CSF) 和血浆中检测到细胞外alpha。我们使用硫黄素S的荧光光谱法和电子显微镜研究了CSF是否会影响alpha的体外聚集。我们发现,与tauopathy和非中枢神经系统疾病相比,从阿尔茨海默氏病 (AD) 和DLB患者获得的CSF增强了alpha原纤维的形成。因此,以Abeta或alpha聚集为特征的AD和DLB的CSF可能会促进falpha的形成。
  • 【过量表达异源 α-淀粉酶引起的生产和分泌压力导致枯草芽孢杆菌的孢子形成抑制和活动期延长。】 复制标题 收藏 收藏
    DOI:10.1128/AEM.00472-07 复制DOI
    作者列表:Lulko AT,Veening JW,Buist G,Smits WK,Blom EJ,Beekman AC,Bron S,Kuipers OP
    BACKGROUND & AIMS: :Transcriptome analysis was used to investigate the global stress response of the gram-positive bacterium Bacillus subtilis caused by overproduction of the well-secreted AmyQ alpha-amylase from Bacillus amyloliquefaciens. Analyses of the control and overproducing strains were carried out at the end of exponential growth and in stationary phase, when protein secretion from B. subtilis is optimal. Among the genes that showed increased expression were htrA and htrB, which are part of the CssRS regulon, which responds to high-level protein secretion and heat stress. The analysis of the transcriptome profiles of a cssS mutant compared to the wild type, under identical secretion stress conditions, revealed several genes with altered transcription in a CssRS-dependent manner, for example, citM, ylxF, yloA, ykoJ, and several genes of the flgB operon. However, high-affinity CssR binding was observed only for htrA, htrB, and, possibly, citM. In addition, the DNA macroarray approach revealed that several genes of the sporulation pathway are downregulated by AmyQ overexpression and that a group of motility-specific (sigmaD-dependent) transcripts were clearly upregulated. Subsequent flow-cytometric analyses demonstrate that, upon overproduction of AmyQ as well as of a nonsecretable variant of the alpha-amylase, the process of sporulation is severely inhibited. Similar experiments were performed to investigate the expression levels of the hag promoter, a well-established reporter for sigmaD-dependent gene expression. This approach confirmed the observations based on our DNA macroarray analyses and led us to conclude that expression levels of several genes involved in motility are maintained at high levels under all conditions of alpha-amylase overproduction.
    背景与目标: : 转录组分析用于研究由解淀粉芽孢杆菌分泌充分的AmyQ α-淀粉酶过量产生引起的革兰氏阳性细菌枯草芽孢杆菌的整体应激反应。当枯草芽孢杆菌的蛋白质分泌最佳时,在指数生长结束时和固定相进行对照和过量生产菌株的分析。表达增加的基因包括htrA和htrB,它们是CssRS调节子的一部分,它们对高水平的蛋白质分泌和热应激做出反应。在相同的分泌胁迫条件下,与野生型相比,对cssS突变体的转录组谱进行分析,揭示了几个以CssRS依赖性方式改变转录的基因,例如citM,ylxF,yloA,ykoJ和flgB操纵子的几个基因。然而,仅在htrA,htrB和可能的citM中观察到高亲和力的CssR结合。此外,DNA macroarray方法揭示了孢子形成途径的几个基因被AmyQ过表达下调,并且一组运动性特异性 (sigmaD依赖性) 转录本被明显上调。随后的流式细胞仪分析表明,在过量生产AmyQ以及不可分泌的 α-淀粉酶变体后,孢子形成过程受到严重抑制。进行了类似的实验以研究hag启动子的表达水平,hag启动子是sigmaD依赖性基因表达的公认报告基因。这种方法证实了基于我们的DNA宏观阵列分析的观察结果,并使我们得出结论,在所有 α-淀粉酶过度生产的条件下,与运动有关的几个基因的表达水平都保持在高水平。
  • 【包括HDL在内的氧化脂蛋白及其脂质过氧化产物抑制THP-1人巨噬细胞分泌TNF-α。】 复制标题 收藏 收藏
    DOI:10.1016/s0891-5849(97)00061-0 复制DOI
    作者列表:Girona J,La Ville AE,Heras M,Olivé S,Masana L
    BACKGROUND & AIMS: It has been established that oxidized LDL (ox-LDL) modifies cytokine secretion by macrophages, for example, by reducing tumor necrosis factor alpha (TNF-(alpha) m-RNA. However, little is known about the effects of oxidized high density lipoprotein (ox-HDL). This study reports the effects of ox-HDL subfractions 2 and 3 (ox-HDL2, ox-HDL3) compared with that of ox-LDL and some products of oxidation (hydroperoxides and aldehydes) on the secretion of TNF-alpha from THP-1 human monocytes derived macrophages in vitro. HDL2, HDL3 and LDL were oxidized with 10 microM Cu++ for 12 h and/or 24 h. Native and oxidized HDL and LDL were incubated for 24 h with macrophages with or without LPS (10 ng/ml) after which TNF-alpha secretion was measured in the culture medium. Lipid hydroperoxides and apolar aldehydes were also incubated with the cells for 2 h following which the medium was replaced and TNF-alpha secretion measured after a further 22 h of incubation. An inhibition of TNF-alpha by ox-HDL2 (p < .05), ox-HDL3 (p < .05) and ox-LDL (p < .05) from THP-1 macrophages was observed in the presence and absence of LPS. This inhibition remained the same after incubation with ox-HDL 12 h and 24 h. Hydroperoxides of linoleic acid did not modify TNF-alpha secretion by cells while five out of eight aldehydes analyzed (2,4-heptadienal, hexanal, 2-nonenal, 2-octenal, 2,4-decadienal) inhibited TNF-alpha secretion (p < .05). These findings demonstrate that ox-HDL, and some of its lipid peroxidation products, plays a role in the modulation of the inflammatory response by macrophages as previously observed for ox-LDL.

    背景与目标: 已经确定氧化的LDL (ox-LDL) 修饰巨噬细胞的细胞因子分泌,例如,通过减少肿瘤坏死因子 α (TNF-(α) m-RNA。然而,对氧化型高密度脂蛋白 (ox-HDL) 的影响知之甚少。这项研究报告了ox-HDL亚组分2和3 (ox-HDL2,ox-HDL3) 与ox-LDL和某些氧化产物 (氢过氧化物和醛) 对体外THP-1人单核细胞来源的巨噬细胞分泌TNF-α 的影响相比。HDL2,HDL3和LDL用10 microM Cu ++ 氧化12小时和/或24小时。将天然和氧化的HDL和LDL与有或没有LPS (10 ng/ml) 的巨噬细胞孵育24小时,然后在培养基中测量TNF-α 分泌。脂质氢过氧化物和极性醛还与细胞一起孵育2小时,然后更换培养基,再孵育22小时后测量TNF-α 分泌。ox-HDL2对TNF-α 的抑制作用 (p <.05),在存在和不存在LPS的情况下观察到来自THP-1巨噬细胞的ox-HDL3 (p < .05) 和ox-LDL (p <.05)。与ox-HDL孵育12小时和24小时后,这种抑制作用保持不变。亚油酸的氢过氧化物不会改变细胞分泌TNF-α,而五在分析的八种醛中 (2,4-庚二烯醛,己醛,2-壬烯醛,2-辛烯醛,2,4-癸烯醛) 抑制TNF-α 分泌 (p <.05)。这些发现表明ox-HDL及其某些脂质过氧化产物,如先前对ox-LDL所观察到的,在巨噬细胞调节炎症反应中起作用。
  • 【从杆状病毒感染的草地贪夜蛾 (IPLB-SF-21AE) 细胞的高尔基样膜中纯化和鉴定 α-甘露糖苷酶II。】 复制标题 收藏 收藏
    DOI:10.1042/bj3240951 复制DOI
    作者列表:Ren J,Castellino FJ,Bretthauer RK
    BACKGROUND & AIMS: An alpha-mannosidase II-like activity was identified in baculovirus-infected Spodoptera frugiperda (IPLB-SF21-AE) cells. The enzyme responsible was purified from Golgi-type membranes to apparent homogeneity by using a combination of steps including DEAE-cellulose, hydroxyapatite, concanavalin A-Sepharose and gel filtration chromatography. The molecular mass of this purified protein was approx. 120 kDa by SDS/PAGE under reducing conditions and approx. 240 kDa under non-reducing conditions, indicating that the enzyme is a disulphide-linked dimer. Substrates demonstrated to undergo hydrolysis with this enzyme were GlcNAc-Man5-GlcNAc-GlcNAc (non-reduced and reduced) and p-nitrophenyl alpha-d-mannopyranoside. The oligosaccharide substrate was converted into GlcNAc-Man3-GlcNAc-GlcNAc through an intermediate GlcNAc-Man4-GlcNAc-GlcNAc. Treatment of the isolated intermediate oligosaccharide with endoglycosidase H resulted in its conversion into GlcNAc-Man4-GlcNAc. This indicated that it contained the alpha-1,3-linked mannose residue on the alpha-1,6-linked mannose arm and showed that the alpha-1,6-linked mannose residue on the alpha-1,6-linked mannose arm had been preferentially hydrolysed by the mannosidase. The oligosaccharide lacking the beta-1,2-linked GlcNAc residue on the alpha-1,3-linked mannose arm (Man5-GlcNAc-GlcNAc) was not hydrolysed in the presence of the enzyme. Metal ions were not required for enzymic activity on any of the substrates, but Cu2+ was strongly inhibitory. The activity of the enzyme was inhibited at low concentrations of swainsonine, but much higher concentrations of 1-deoxymannojirimycin were required to achieve inhibition. All of these properties are characteristic of mannosidase II enzymes from other eukaryotic tissues. The presence of mannosidase II in lepidopteran insect cells would allow entry of N-linked glycoproteins into the complex processing reaction pathway or into the terminal Man3-GlcNAc-GlcNAc pathway.

    背景与目标: 在杆状病毒感染的草地贪夜蛾 (IPLB-SF21-AE) 细胞中鉴定出 α-甘露糖苷酶II样活性。通过使用DEAE-纤维素,羟基磷灰石,伴刀豆球蛋白a-琼脂糖和凝胶过滤色谱等步骤的组合,将负责的酶从高尔基体型膜中纯化至表观均一。该纯化蛋白的分子量约为。在还原条件下通过SDS/PAGE 120 kDa。在非还原条件下240 kDa,表明该酶是二硫化物连接的二聚体。GlcNAc-Man5-GlcNAc-GlcNAc (非还原和还原) 和对硝基苯基 α-d-甘露吡喃糖苷,证明用该酶水解的底物。通过中间GlcNAc-Man4-GlcNAc-GlcNAc将寡糖底物转化为GlcNAc-Man3-GlcNAc-GlcNAc。用内切糖苷酶H处理分离的中间寡糖导致其转化为GlcNAc-Man4-GlcNAc。这表明它在 α-1,6-连接的甘露糖臂上包含 α-1,3-连接的甘露糖残基,并表明 α-1,6-连接的甘露糖上的 α-1,6-连接的甘露糖残基已优先被甘露糖苷酶水解。在存在该酶的情况下,没有在 α-1,3-连接的甘露糖臂 (Man5-GlcNAc-GlcNAc) 上缺少 β-1,2-连接的GlcNAc残基的寡糖被水解。在任何底物上的酶活性都不需要金属离子,但是Cu2具有强烈的抑制作用。在低浓度的swainsonine下,酶的活性受到抑制,但是需要更高浓度的1-脱氧甘露霉素才能达到抑制作用。所有这些特性都是来自其他真核组织的甘露糖苷酶II酶的特征。鳞翅目昆虫细胞中甘露糖苷酶II的存在将允许N-连接的糖蛋白进入复杂的加工反应途径或末端Man3-GlcNAc-GlcNAc途径。

+1
+2
100研值 100研值 ¥99课程
检索文献一次
下载文献一次

去下载>

成功解锁2个技能,为你点赞

《SCI写作十大必备语法》
解决你的SCI语法难题!

技能熟练度+1

视频课《玩转文献检索》
让你成为检索达人!

恭喜完成新手挑战

手机微信扫一扫,添加好友领取

免费领《Endnote文献管理工具+教程》

微信扫码, 免费领取

手机登录

获取验证码
登录