• 【通过核酸碱基的四分之一化与芳香族氨基酸的突出堆积相互作用:X射线晶体学特征和生物学意义。】 复制标题 收藏 收藏
    DOI:10.1016/0003-9861(90)90251-s 复制DOI
    作者列表:Ishida T,Ueda H,Segawa K,Doi M,Inoue M
    BACKGROUND & AIMS: :In order to investigate the mode of interaction between the N-quarternized cytosine base and the aromatic amino acid, the crystal structure of the 3-methyl-cytidine-5'-monophosphate:tryptamine complex was analyzed by X-ray diffraction. The complex crystals were stabilized by extensive hydrogen bond formations in which eight independent water molecules per complex pair participated. A prominent stacking interaction, characterized by a parallel alignment of both rings with a separation distance of ca. 3.4 A, was observed between the cytosine base and the indole ring. Combining the present results with X-ray crystallographic data on the adenine--and guanine--aromatic amino acid interactions, we summarize the structural characteristics observed in the stacking interaction of the N-quarternized nucleic acid base with the aromatic amino acid and discuss their biological implications, especially in connection with the significance of N-protonation of nucleic acid base for selective recognition by protein.
    背景与目标: :为了研究N-季铵化的胞嘧啶碱基与芳族氨基酸之间的相互作用方式,通过X射线衍射分析了3-甲基胞苷-5'-单磷酸酯:色胺的配合物的晶体结构。复杂的晶体通过广泛的氢键形成而稳定,其中每个复杂对有八个独立的水分子参与。突出的堆叠相互作用,其特征在于两个环的平行排列的间隔距离为ca。在胞嘧啶碱基和吲哚环之间观察到3.4A。将当前结果与腺嘌呤-鸟嘌呤-芳族氨基酸相互作用的X射线晶体学数据相结合,我们总结了在N-季铵化核酸碱基与芳族氨基酸的堆叠相互作用中观察到的结构特征,并讨论了它们的结构特征。生物学意义,特别是与核酸碱基的N质子化对于蛋白质选择性识别的意义有关。
  • 【社交,运动,饮食和年龄对食蟹猴发展中和未治疗的糖尿病的作用。】 复制标题 收藏 收藏
    DOI:10.1016/j.exger.2017.06.010 复制DOI
    作者列表:Yue F,Zhang G,Quintero JE,Gash DM,Zhang Z
    BACKGROUND & AIMS: :Type 2 diabetes mellitus is the most common form of diabetes that occurs in both human and nonhuman primates. Although spontaneously diabetic nonhuman primates are used extensively in diabetic related research and are a proven valuable tool for the study of the natural history of diabetes, little is known about the key factors that can cause this metabolic disorder and the preventative measures that could be employed to minimize the consequences of diabetes. Using a model of developing and untreated diabetes, this study describes the effects of housing arrangement (socially group- versus individually single-housed), exercise, diet, age, and sex on fasting plasma glucose, key lipids associated with diabetes, and bodyweight in two large cohorts of nonhuman primates. Key findings include exercise/housing arrangement's contribution to significant differences in bodyweight, levels of fasting plasma glucose, total cholesterol, and high- and low-density lipoproteins. Age also had profound effects on glucose, triglyceride and high-density lipoproteins, particularly in single-caged animals. Moreover, females had higher fasting glucose, total cholesterol and triglyceride levels than male counterparts within the same housing situations. These factors may be critical to identifying preventive measures that could eventually be used to minimize obesity and diabetes in humans.
    背景与目标: 2型糖尿病是人类和非人类灵长类动物中最常见的糖尿病形式。尽管自发性糖尿病非人类灵长类动物在糖尿病相关研究中被广泛使用,并且是研究糖尿病自然史的一种被证明有价值的工具,但对于引起这种代谢紊乱的关键因素以及可以采取的预防措施知之甚少尽量减少糖尿病的后果。本研究使用发展中的糖尿病和未经治疗的糖尿病模型,描述了住房安排(集体居住与个人独居),运动,饮食,年龄和性别对空腹血糖,糖尿病相关的主要脂质和体重的影响。两个大型的非人类灵长类动物。主要发现包括运动/住房安排对体重,空腹血糖水平,总胆固醇以及高密度和低密度脂蛋白的显着差异的贡献。年龄对葡萄糖,甘油三酸酯和高密度脂蛋白也有深远的影响,特别是在单笼动物中。此外,在相同的居住环境下,女性的空腹血糖,总胆固醇和甘油三酸酯水平高于男性。这些因素对于确定预防措施至关重要,这些预防措施最终可用于最大程度地减少人类的肥胖和糖尿病。
  • 【填补空白:痕量眨眼调节中空间差异的证据。】 复制标题 收藏 收藏
    DOI:10.1016/j.neulet.2017.06.011 复制DOI
    作者列表:Larra MF,Behrje A,Finke JB,Blumenthal TD,Schächinger H
    BACKGROUND & AIMS: :Trace eyeblink conditioning is used as a translational model of declarative memory but restricted to the temporal domain. Potential spatial aspects have never been experimentally addressed. We employed a spatiotemporal trace eyeblink conditioning paradigm in which a spatial dimension (application side of the unconditioned stimulus) was differentially coded by tone frequency of the conditioned stimulus and recorded conditioned reactions from both eyes. We found more and stronger conditioned reactions at the side predicted by the conditioned stimulus but only in aware participants. Thus, spatial effects are present in trace eyeblink conditioning and may be differentially conditioned depending on the awareness about the spatial relation between conditioned and unconditioned stimulus.
    背景与目标: :Trace眨眼条件用作声明性记忆的翻译模型,但仅限于时域。潜在的空间方面从未实验性地解决过。我们采用了时空迹线眨眼条件范式,其中空间维度(未条件刺激的应用侧)通过条件刺激的音调频率进行了差分编码,并记录了两只眼睛的条件反应。我们在条件刺激所预测的一侧发现了更多且更强的条件反应,但仅在有意识的参与者中。因此,空间效应存在于微量眨眼条件中,并且可以根据对条件刺激与非条件刺激之间的空间关系的了解而有区别地进行调节。
  • 【组蛋白伴侣Asp1的C末端与酵母中的组蛋白H3交联,并促进与组蛋白H3和H4的相互作用。】 复制标题 收藏 收藏
    DOI:10.1128/MCB.01053-12 复制DOI
    作者列表:Dennehey BK,Noone S,Liu WH,Smith L,Churchill ME,Tyler JK
    BACKGROUND & AIMS: :The central histone H3/H4 chaperone Asf1 comprises a highly conserved globular core and a divergent C-terminal tail. While the function and structure of the Asf1 core are well known, the function of the tail is less well understood. Here, we have explored the role of the yeast (yAsf1) and human (hAsf1a and hAsf1b) Asf1 tails in Saccharomyces cerevisiae. We show, using a photoreactive, unnatural amino acid, that Asf1 tail residue 210 cross-links to histone H3 in vivo and, further, that loss of C-terminal tail residues 211 to 279 weakens yAsf1-histone binding affinity in vitro nearly 200-fold. Via several yAsf1 C-terminal truncations and yeast-human chimeric proteins, we found that truncations at residue 210 increase transcriptional silencing and that the hAsf1a tail partially substitutes for full-length yAsf1 with respect to silencing but that full-length hAsf1b is a better overall substitute for full-length yAsf1. In addition, we show that the C-terminal tail of Asf1 is phosphorylated at T270 in yeast. Loss of this phosphorylation site does not prevent coimmunoprecipitation of yAsf1 and Rad53 from yeast extracts, whereas amino acid residue substitutions at the Asf1-histone H3/H4 interface do. Finally, we show that residue substitutions in yAsf1 near the CAF-1/HIRA interface also influence yAsf1's function in silencing.
    背景与目标: :中央组蛋白H3 / H4分子伴侣Asf1包含高度保守的球状核和发散的C末端尾巴。虽然Asf1核心的功能和结构是众所周知的,但尾部的功能却鲜为人知。在这里,我们探讨了酵母(yAsf1)和人(hAsf1a和hAsf1b)Asf1尾巴在酿酒酵母中的作用。我们显示,使用光反应性的非天然氨基酸,ASF1尾巴残基210在体内交联至组蛋白H3,此外,C末端尾巴残基211至279的损失削弱了yAsf1-histone结合亲和力,在体外接近200-折叠。通过几个yAsf1 C端截短和酵母-人类嵌合蛋白,我们发现残基210的截短增加了转录沉默,并且hAsf1a尾部在沉默方面部分替代了全长yAsf1,但全长hAsf1b总体上更好替代全长yAsf1。此外,我们显示出Asf1的C末端尾巴在酵母中的T270处被磷酸化。该磷酸化位点的丢失不能阻止酵母提取物中yAsf1和Rad53的共免疫沉淀,而Asf1-histone H3 / H4界面的氨基酸残基取代确实可以。最后,我们表明在CAF-1 / HIRA界面附近的yAsf1中的残基取代也会影响yAsf1的沉默功能。
  • 【等离子喷涂碳纳米管增强羟基磷灰石涂层及其在体外与人成骨细胞的相互作用。】 复制标题 收藏 收藏
    DOI:10.1016/j.biomaterials.2006.09.013 复制DOI
    作者列表:Balani K,Anderson R,Laha T,Andara M,Tercero J,Crumpler E,Agarwal A
    BACKGROUND & AIMS: :Carbon nanotubes (CNT) possess excellent mechanical properties to play the role as reinforcement for imparting strength and toughness to brittle hydroxyapatite (HA) bioceramic coating. However, lack of processing technique to uniformly distribute multiwalled CNTs in HA coating and limited studies and sparse knowledge evincing toxicity of CNTs has kept researchers in dispute for long. In the current work, we have addressed these issues by (i) successfully distributing multiwalled CNT reinforcement in HA coating using plasma spraying to improve the fracture toughness (by 56%) and enhance crystallinity (by 27%), and (ii) culturing human osteoblast hFOB 1.19 cells onto CNT reinforced HA coating to elicit its biocompatibility with living cells. Unrestricted growth of human osteoblast hFOB 1.19 cells has been observed near CNT regions claiming assistance by CNT surfaces to promote cell growth and proliferation.
    背景与目标: :碳纳米管(CNT)具有出色的机械性能,可充当增强剂,为脆性羟基磷灰石(HA)生物陶瓷涂层赋予强度和韧性。然而,缺乏在HA涂层中均匀分布多壁CNT的加工技术,有限的研究以及有关CNTs毒性的稀疏知识一直困扰着研究人员。在当前的工作中,我们已通过以下方法解决了这些问题:(i)使用等离子喷涂成功地在HA涂层中分配多壁CNT增强材料,以提高断裂韧性(提高56%)和增强结晶度(提高27%),以及(ii)培养人将成骨细胞hFOB 1.19细胞涂在CNT增强的HA涂层上,以引发其与活细胞的生物相容性。在CNT区域附近观察到人类成骨细胞hFOB 1.19细胞的生长不受限制,声称其受CNT表面的辅助来促进细胞生长和增殖。
  • 【从病床到病床的评估:重症患者的脑-肺相互作用-重新审视一个悬而未决的问题。】 复制标题 收藏 收藏
    DOI:10.1186/cc5930 复制DOI
    作者列表:Gonzalvo R,Martí-Sistac O,Blanch L,López-Aguilar J
    BACKGROUND & AIMS: :Brain and/or lung injury is the most frequent cause of admission to critical care units and patients in this setting frequently develop multiple organ dysfunction with high rates of morbidity and mortality. Mechanical ventilation is commonly used in the management of these critically ill patients and the consequent inflammatory response, together with other physiological factors, is also thought to be involved in distal organ dysfunction. This peripheral imbalance is based on a multiple-pathway cross-talk between the lungs and other organs, including the brain. Interestingly, acute respiratory distress syndrome survivors frequently present some cognitive deterioration at discharge. Such neurological dysfunction might be a secondary marker of injury and the neuroanatomical substrate for downstream impairment of other organs. Brain-lung interactions have received little attention in the literature, but recent evidence suggests that both the lungs and brain are promoters of inflammation through common mediators. This review addresses the current status of evidence regarding brain-lung interactions, their pathways and current interventions in critically ill patients receiving mechanical ventilation.
    背景与目标: :脑部和/或肺部损伤是重症监护病房最常见的病因,在这种情况下,患者经常发展为多器官功能障碍,发病率和死亡率较高。机械通气通常用于这些重症患者的治疗,随之而来的炎症反应以及其他生理因素也被认为与远端器官功能障碍有关。这种外围失衡是基于肺与其他器官(包括大脑)之间的多路径串扰。有趣的是,急性呼吸窘迫综合征幸存者经常在出院时表现出一些认知能力下降。这种神经功能障碍可能是损伤的次要标志,也是其他器官下游损伤的神经解剖学底物。脑-肺之间的相互作用在文献中很少受到关注,但是最近的证据表明,肺和脑都是通过常见的介质促进炎症的。这篇综述讨论了有关机械通气的危重患者脑-肺相互作用,其通路和当前干预措施的证据的现状。
  • 【Syndecan-1与层粘连蛋白332中的LG4 / 5结构域的相互作用对于角质形成细胞迁移至关重要。】 复制标题 收藏 收藏
    DOI:10.1002/jcp.21184 复制DOI
    作者列表:Bachy S,Letourneur F,Rousselle P
    BACKGROUND & AIMS: :Laminin 5/laminin 332 (LN332) is an adhesion substrate for epithelial cells. After secretion of LN332, a regulated cleavage occurs at the carboxy-terminus of its alpha3 subunit, which releases a tandem of two globular modules named LG4/5. We show that the presence of the LG4/5 domain in precursor LN332 decreases its integrin-mediated cell adhesion properties in comparison with mature LN332. Whereas cell adhesion to the recombinant LG4/5 fragment relies solely on the heparan sulfate proteoglycan (HSPG) receptor syndecan-1, we reveal that both syndecan-1 and the alpha3beta1 integrin bind to precursor LN332. We further demonstrate that syndecan-1 mediated cell adhesion to the LG4/5 fragment and pre-LN332 allows the formation of fascin-containing protrusions, depending on the GTPases Rac and Cdc42 activation. Reducing syndecan-1 expression in normal keratinocytes prevents cell protrusions on pre-LN332 with subsequent failure of the peripheral localization of the alpha3beta1 integrin. We finally show that cell migration on pre-LN332 requires syndecan-1. Therefore, the LG4/5 domain in precursor LN332 appears to trigger intracellular signaling events, which participate in keratinocyte motility.
    背景与目标: :层粘连蛋白5 /层粘连蛋白332(LN332)是上皮细胞的粘附底物。 LN332分泌后,在其alpha3亚基的羧基末端发生有规律的切割,释放出串联的两个球形模块LG4 / 5。我们显示,与成熟的LN332相比,前体LN332中LG4 / 5域的存在降低了其整合素介导的细胞粘附特性。虽然细胞对重组LG4 / 5片段的粘附仅依赖于硫酸乙酰肝素蛋白聚糖(HSPG)受体syndecan-1,但我们发现syndecan-1和alpha3beta1整联蛋白均与前体LN332结合。我们进一步证明了syndecan-1介导的细胞粘附到LG4 / 5片段和pre-LN332允许形成含有fascin的突起,具体取决于GTPa​​ses Rac和Cdc42的激活。减少正常角质形成细胞中syndecan-1的表达可以防止pre-LN332上的细胞突出,并随后导致alpha3beta1整联蛋白的外周定位失败。我们最终证明,前LN332上的细胞迁移需要syndecan-1。因此,前体LN332中的LG4 / 5结构域似乎触发了细胞内信号传导事件,该事件参与了角质形成细胞的运动。
  • 【铁和霉酚酸酯的吸收之间不存在相互作用。】 复制标题 收藏 收藏
    DOI:10.1111/j.1365-2125.2005.02541.x 复制DOI
    作者列表:Ducray PS,Banken L,Gerber M,Boutouyrie B,Zandt H
    BACKGROUND & AIMS: AIM:To determine whether concomitant iron affects the absorption of mycophenolate mofetil. METHODS:An open-label, single centre, randomized, crossover trial was conducted in 16 healthy males. Fasting subjects received mycophenolate mofetil alone (treatment A) or co-administered with iron (treatment B). RESULTS:The mycophenolic acid AUC(0,24 h) for treatments A and B were 42.5 +/- 10.5 and 44.7 +/- 12.4 microg ml(-1) h, respectively. anova modelling showed the relative bioavailability of mycophenolate mofetil to be similar for the two treatments (90% confidence interval 0.92, 1.19). CONCLUSIONS:There was no interaction between mycophenolate mofetil and iron supplements administered concomitantly to healthy fasting subjects.
    背景与目标: 目的:确定伴随的铁是否影响霉酚酸酯的吸收。
    方法:对16名健康男性进行了开放标签,单中心,随机,交叉试验。空腹受试者单独接受霉酚酸酯(治疗A)或与铁合用(治疗B)。
    结果:处理A和B的霉酚酸AUC(0,24 h)分别为42.5 /-10.5和44.7 /-12.4 microg ml(-1)h。方差分析建模显示,两种处理的霉酚酸酯的相对生物利用度相似(90%置信区间为0.92、1.19)。
    结论:麦考酚酸酯与健康禁食对象同时服用铁补充剂之间没有相互作用。
  • 【多巴胺D1和NMDA受体之间的突触后相互作用通过腺苷释放促进伏隔大鼠核中的突触前抑制。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Harvey J,Lacey MG
    BACKGROUND & AIMS: :The mechanism underlying dopamine D1 receptor-mediated attenuation of glutamatergic synaptic input to nucleus accumbens (NAcc) neurons was investigated in slices of rat forebrain, using whole-cell patch-clamp recording. The depression by dopamine of EPSCs evoked by single-shock cortical stimulation was stimulus-dependent. Synaptic activation of NMDA-type glutamate receptors was critical for this effect, because dopamine-induced EPSC depressions were blocked by the competitive NMDA receptor antagonist D/L-2-amino-5-phosphonopentanoate (AP5). Application of NMDA also depressed the EPSC, and both this effect and the dopamine depressions were blocked by the A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), implicating adenosine release in the EPSC depression. A1 receptor agonists also depressed EPSCs by a presynaptic action, causing increased paired-pulse facilitation, but this was insensitive to AP5. Activation of D1 receptors enhanced both postsynaptic inward currents evoked by NMDA application and the isolated NMDA receptor-mediated component of synaptic transmission. The biochemical processes underlying the dopamine-induced EPSC depression did not involve either protein kinase A or the production of cAMP and its metabolites, because this effect was resistant to the protein kinase inhibitors H89 and H7 and the cAMP-specific phosphodiesterase inhibitor rolipram. We conclude that activation of postsynaptic D1 receptors enhances the synaptic activation of NMDA receptors in nucleus accumbens neurons, thereby promoting a transsynaptic feedback inhibition of glutamatergic synaptic transmission via release of adenosine. Unusually for D1 receptors, this phenomenon occurs independently of adenylyl cyclase stimulation. This process may contribute to the locomotor stimulant action of dopaminergic agents in the NAcc.
    背景与目标: :使用全细胞膜片钳记录技术,在大鼠前脑切片中研究了多巴胺D1受体介导的伏谷核(NAcc)神经元的谷氨酸能突触输入衰减的机制。单电刺激皮层刺激引起的EPSCs的多巴胺抑制与刺激有关。 NMDA型谷氨酸受体的突触激活对此效应至关重要,因为多巴胺诱导的EPSC抑郁症被竞争性NMDA受体拮抗剂D / L-2-氨基-5-膦基戊酸酯(AP5)阻止。 NMDA的应用也抑制了EPSC,这种作用和多巴胺抑制均被A1受体拮抗剂8-环戊基-1,3-二丙基黄嘌呤(DPCPX)阻断,这暗示了EPSC抑制中腺苷的释放。 A1受体激动剂还通过突触前作用抑制EPSC,导致成对脉冲促进作用增强,但这对AP5不敏感。 D1受体的激活增强了NMDA的应用诱发的突触后内向电流和突触传递的分离的NMDA受体介导的成分。多巴胺引起的EPSC抑郁症的生化过程既不涉及蛋白激酶A,也不涉及cAMP及其代谢产物的产生,因为这种作用对蛋白激酶抑制剂H89和H7以及cAMP特异性磷酸二酯酶抑制剂咯利普兰具有抵抗力。我们得出的结论是,突触后D1受体的激活增强伏伏核神经元中NMDA受体的突触激活,从而通过释放腺苷促进谷氨酸能突触传递的突触反馈抑制。对于D1受体,这种现象通常与腺苷酸环化酶的刺激无关地发生。该过程可能有助于NAcc中多巴胺能药物的运动刺激作用。
  • 【氨基酸残基在T细胞决定簇中的关键作用是由于其与相邻的非关键残基的相互作用。】 复制标题 收藏 收藏
    DOI:10.1002/eji.1830200939 复制DOI
    作者列表:Boyer M,Novak Z,Fotedar A,Fraga E,Singh B
    BACKGROUND & AIMS: :Several lines of evidence support the concept of two functionally distinct sites on antigen: the epitope, involved in interaction with the T cell receptor and the agretope, interacting with Ia. We investigated the Ia and T cell receptor interaction sites on the synthetic polypeptide antigen poly-18 [poly-EYK(EYA)5] using T cell hybridoma clones specific for this antigen in the context of I-Ad. Peptides with amino acid sequences related to poly-18 were synthesized. These were used to identify the critical residues in the minimum peptide sequence required for activation. Clone A.1.1 responds to the minimal peptide EYK(EYA)4 but not to (EYA)5. This identifies Lys3 as a critical amino acid for this hybridoma. Surprisingly, the substituted peptide EYAEAA(EYA)3 could activate A.1.1, indicating that an Ala at position 5 instead of a Tyr obviates the critical requirement for Lys3. This demonstrates that the function of critical residues may extend beyond contacting the T cell receptor or Ia, to include a third role: that of interacting with other amino acids of the T cell epitope, thus influencing the antigen's recognition by T cells.
    背景与目标: :有几条证据支持抗原上两个功能上不同的位点的概念:抗原决定簇,与T细胞受体相互作用,而抗原决定簇与Ia,相互作用。我们在I-Ad的背景下,使用对这种抗原具有特异性的T细胞杂交瘤克隆,研究了合成多肽抗原poly-18 [poly-EYK(EYA)5]上的Ia和T细胞受体相互作用位点。合成了具有与poly-18相关的氨基酸序列的肽。这些用于鉴定激活所需的最小肽序列中的关键残基。克隆A.1.1对最小肽EYK(EYA)4响应,但对(EYA)5没有响应。这将Lys3鉴定为该杂交瘤的关键氨基酸。出人意料的是,取代的肽EYAEAA(EYA)3可以激活A.1.1,表明位置5处的Ala而不是Tyr消除了Lys3的关键要求。这表明关键残基的功能可能超出接触T细胞受体或Ia的范围,包括第三种作用:与T细胞表位的其他氨基酸相互作用,从而影响抗原对T细胞的识别。
  • 【在健康受试者中,稳态罗氟司特和单剂量咪达唑仑之间缺乏药代动力学相互作用。】 复制标题 收藏 收藏
    DOI:10.1111/j.1365-2125.2006.02762.x 复制DOI
    作者列表:Nassr N,Lahu G,von Richter O,Reutter F,Knoerzer D,Zech K,Erb KA,Schug B,Blume H,Hermann R
    BACKGROUND & AIMS: AIMS:The aim of this study was to investigate the effects of roflumilast, an investigational PDE4 inhibitor for the treatment of COPD and asthma, on the pharmacokinetics of the CYP3A probe drug midazolam and its major metabolites. METHODS:In an open, randomized (for midazolam treatment sequence) study, 18 healthy male subjects received single doses of midazolam (2 mg oral and 1 mg i.v., 1 day apart) alone, repeated doses of roflumilast (500 microg once daily for 14 days) alone, and repeated doses of roflumilast together with single doses of midazolam (2 mg oral and 1 mg i.v., 1 day apart). RESULTS:A comparison of clearance and peak and systemic exposure to midazolam following administration of roflumilast indicated no effect of roflumilast dosed to steady state on the pharmacokinetics of midazolam. Point estimates (90% CI) were 0.97 (0.84, 1.13) for the AUC of i.v. midazolam and 0.98 (0.82, 1.17) for that of oral midazolam with and without roflumilast. CONCLUSIONS:Therapeutic steady state concentrations of roflumilast and its N-oxide do not alter the disposition of the CYP3A substrate midazolam in healthy subjects. This finding suggests that roflumilast is unlikely to alter the clearance of drugs that are metabolized by CYP3A4.
    背景与目标: 目的:本研究的目的是研究用于研究COPD和哮喘的PDE4抑制剂罗氟司特对CYP3A探针药物咪达唑仑及其主要代谢物的药代动力学。
    方法:在一项开放,随机(针对咪达唑仑治疗序列)的研究中,18名健康男性受试者单独接受单剂量的咪达唑仑(2 mg口服和1 mg iv,相隔1天),重复剂量的鲁氟司特(500 microg,每天一次,共14剂)天),重复剂量的罗氟司特和单剂量的咪达唑仑(2 mg口服和1 mg iv,间隔1天)。
    结果:比较使用氟氟司特后咪达唑仑的清除率,峰和全身暴露的清除率,表明洛氟司特剂量稳定后对咪达唑仑的药代动力学没有影响。 i.v. AUC的点估计值(90%CI)为0.97(0.84,1.13)。咪达唑仑和口服咪达唑仑含或不含roflumilast的口服咪达唑仑均为0.98(0.82,1.17)。
    结论:罗氟司特及其氮氧化物的治疗稳态浓度不会改变CYP3A底物咪达唑仑在健康受试者中的分布。该发现表明罗氟司特不太可能改变被CYP3A4代谢的药物的清除率。
  • 【血管紧张素II型1A受体信号传导通过P-选择蛋白介导的肿瘤细胞与血小板和内皮细胞的相互作用促进肿瘤转移的形成。】 复制标题 收藏 收藏
    DOI:10.1016/j.ajpath.2012.10.026 复制DOI
    作者列表:Amano H,Ito Y,Ogawa F,Eshima K,Suzuki T,Oba K,Matsui Y,Kato S,Fukui T,Nakamura M,Kitasato H,Fukamizu A,Majima M
    BACKGROUND & AIMS: :Angiotensin II is involved in tumor growth; however, the precise mechanism is not known. Platelets also contribute to tumor growth, and angiotensin II type 1 receptor (AT1) is expressed on the platelet surface. We hypothesized that interaction of platelets with tumor cells through AT1 receptor signaling promotes tumor metastasis. B16F1 melanoma cells were intravenously injected into Agtr1a knockout mice (AT1a(-/-)) and wild-type littermates (WT); the AT1a(-/-) mice exhibited a reduction in lung colonies. Angiotensin II induced expression of P-selectin on platelets in WT but not in AT1a(-/-) mice. A selective P-selectin neutralizing antibody decreased lung colony numbers in WT but not in AT1a(-/-) mice. Levels of vascular endothelial growth factor (VEGF) and stromal cell-derived factor 1 (SDF-1) receptor in platelets at metastatic locus were lower in AT1a(-/-) mice. Treatment of neutralizing antibodies against VEGF and CXCR4 decreased lung colony numbers in WT but not in AT1a(-/-) mice. In AT1a(-/-) mice, and both mobilization of progenitor cells expressing CXCR4(+)VEGFR1(+) cells from bone marrow and their recruitment to lung tissues were suppressed. These results suggest that AT1A signaling plays a critical role in tumor metastasis through P-selectin-mediated interactions of platelets with tumor and endothelial cells and through the AT1A signaling-dependent production of VEGF and SDF-1, which may be involved in mobilization of CXCR4(+)VEGFR1(+) cells.
    背景与目标: :血管紧张素II参与肿瘤生长;但是,确切的机制尚不清楚。血小板也有助于肿瘤的生长,并且血管紧张素II 1型受体(AT1)在血小板表面表达。我们假设血小板与肿瘤细胞通过AT1受体信号传导的相互作用促进了肿瘤转移。将B16F1黑色素瘤细胞静脉内注射到Agtr1a基因敲除小鼠(AT1a(-/-))和野生型同窝小鼠(WT)中; AT1a(-/-)小鼠肺集落减少。血管紧张素II诱导WT中血小板上P-选择蛋白的表达,而AT1a(-/-)小鼠中没有。选择性P-选择素中和抗体可降低WT小鼠的肺菌落数量,但不会降低AT1a(-/-)小鼠的肺菌落数量。在AT1a(-/-)小鼠中,转移灶中血小板的血管内皮生长因子(VEGF)和基质细胞衍生因子1(SDF-1)受体水平较低。抗VEGF和CXCR4的中和抗体的治疗可降低WT小鼠的肺菌落数量,但不会降低AT1a(-/-)小鼠的肺菌落数量。在AT1a(-/-)小鼠中,表达CXCR4()VEGFR1()的祖细胞从骨髓动员到肺组织的动员都受到抑制。这些结果表明,AT1A信号传导通过P-选择蛋白介导的血小板与肿瘤和内皮细胞的相互作用以及通过AT1A信号依赖的VEGF和SDF-1的产生在肿瘤转移中起关键作用,这可能与CXCR4的动员有关。 ()VEGFR1()细胞。
  • 【大豆苷元-雌激素在大鼠子宫中的相互作用及其对人乳腺癌细胞生长的影响。】 复制标题 收藏 收藏
    DOI:10.1089/jmf.2011.0322 复制DOI
    作者列表:Gaete L,Tchernitchin AN,Bustamante R,Villena J,Lemus I,Gidekel M,Cabrera G,Astorga P
    BACKGROUND & AIMS: :Sex hormone replacement therapy provides several advantages in the quality of life for climacteric women. However, estrogen-induced cell proliferation in the uterus and mammary gland increases the risk of cancer development in these organs. The lower incidence of mammary cancer in Asian women as compared with Western women has been attributed to high intake of soy isoflavones, including genistein. We have previously shown that genistein induces an estradiol-like hypertrophy of uterine cells, but does not induce cell proliferation, uterine eosinophilia, or endometrial edema. It also inhibits estradiol-induced mitosis in uterine cells and hormone-induced uterine eosinophilia and endometrial edema. Nevertheless, genistein stimulates growth of human breast cancer cells in culture; therefore, it is not an ideal estrogen for use in hormone replacement therapy (HRD). The present study investigated the effect of another soy isoflavone, daidzein (subcutaneous, 0.066 mg/kg body weight), in the same animal model, and its effect on responses induced by subsequent treatment (1 h later) with estradiol-17β (E(2); subcutaneous, 0.33 mg/kg body weight). In addition, we investigated the effects of daidzein (1 μg/mL) or E(2) on the growth of human breast cancer cells in culture. Results indicate that daidzein stimulates growth of breast cancer cells and potentiates estrogen-induced cell proliferation in the uterus. We suggest caution for the use of daidzein or formulas containing this compound in HRD. Future research strategies should be addressed in the search for new phytoestrogens that selectively inhibit cell proliferation in the uterus and breast.
    背景与目标: 性激素替代疗法为更年期妇女的生活质量提供了许多优势。然而,雌激素诱导的子宫和乳腺细胞增殖增加了这些器官中癌症发展的风险。与西方女性相比,亚洲女性的乳腺癌发病率较低是由于大豆异黄酮(包括染料木黄酮)的摄入量较高。我们以前已经表明,染料木黄酮可诱导雌二醇样子宫细胞肥大,但不会诱导细胞增殖,子宫嗜酸性粒细胞增多或子宫内膜水肿。它也抑制雌二醇引起的子宫细胞有丝分裂以及激素引起的子宫嗜酸性粒细胞增多和子宫内膜水肿。然而,染料木黄酮可刺激人类乳腺癌细胞在培养中的生长。因此,它不是用于激素替代疗法(HRD)的理想雌激素。本研究在同一动物模型中研究了另一种大豆异黄酮大豆黄酮(皮下注射,0.066 mg / kg体重)的作用及其对雌二醇17β(E( 2);皮下注射,0.33 mg / kg体重)。此外,我们调查了黄豆苷元(1μg/ mL)或E(2)对培养的人类乳腺癌细胞生长的影响。结果表明,大豆苷元刺激乳腺癌细胞的生长并增强雌激素诱导的子宫内细胞增殖。我们建议在HRD中谨慎使用大豆苷元或含有该化合物的配方。寻找新的植物雌激素以选择性抑制子宫和乳房中的细胞增殖时,应解决未来的研究策略。
  • 【在计算机和体外筛选与Tenofovir,Darunavir和Dapivirine的P-糖蛋白相互作用:局部预防结直肠HIV传播的抗逆转录病毒药物组合。】 复制标题 收藏 收藏
    DOI:10.1021/acs.molpharmaceut.7b00133 复制DOI
    作者列表:Swedrowska M,Jamshidi S,Kumar A,Kelly C,Rahman KM,Forbes B
    BACKGROUND & AIMS: :The aim of the study was to use in silico and in vitro techniques to evaluate whether a triple formulation of antiretroviral drugs (tenofovir, darunavir, and dapivirine) interacted with P-glycoprotein (P-gp) or exhibited any other permeability-altering drug-drug interactions in the colorectal mucosa. Potential drug interactions with P-gp were screened initially using molecular docking, followed by molecular dynamics simulations to analyze the identified drug-transporter interaction more mechanistically. The transport of tenofovir, darunavir, and dapivirine was investigated in the Caco-2 cell models and colorectal tissue, and their apparent permeability coefficient (Papp), efflux ratio (ER), and the effect of transporter inhibitors were evaluated. In silico, dapivirine and darunavir showed strong affinity for P-gp with similar free energy of binding; dapivirine exhibiting a ΔGPB value -38.24 kcal/mol, darunavir a ΔGPB value -36.84 kcal/mol. The rank order of permeability of the compounds in vitro was tenofovir < darunavir < dapivirine. The Papp for tenofovir in Caco-2 cell monolayers was 0.10 ± 0.02 × 10-6 cm/s, ER = 1. For dapivirine, Papp was 32.2 ± 3.7 × 10-6 cm/s, but the ER = 1.3 was lower than anticipated based on the in silico findings. Neither tenofovir nor dapivirine transport was influenced by P-gp inhibitors. The absorptive permeability of darunavir (Papp = 6.4 ± 0.9 × 10-6 cm/s) was concentration dependent with ER = 6.3, which was reduced by verapamil to 1.2. Administration of the drugs in combination did not alter their permeability compared to administration as single agents. In conclusion, in silico modeling, cell culture, and tissue-based assays showed that tenofovir does not interact with P-gp and is poorly permeable, consistent with a paracellular transport mechanism. In silico modeling predicted that darunavir and dapivirine were P-gp substrates, but only darunavir showed P-gp-dependent permeability in the biological models, illustrating that in silico modeling requires experimental validation. When administered in combination, the disposition of the proposed triple-therapy antiretroviral drugs in the colorectal mucosa will depend on their distinctly different permeability, but was not interdependent.
    背景与目标: :该研究的目的是使用计算机模拟和体外技术评估抗逆转录病毒药物(替诺福韦,达那那韦和达匹韦林)的三重制剂是否与P-糖蛋白(P-gp)相互作用或表现出其他改变通透性的药物药物在大肠黏膜中的相互作用。最初使用分子对接筛选与P-gp的潜在药物相互作用,然后进行分子动力学模拟,以更机械地分析已识别的药物-转运蛋白相互作用。在Caco-2细胞模型和结直肠组织中研究了Tenofovir,darunavir和dapivirine的转运,并评估了它们的表观通透性系数(Papp),流出比(ER)和转运蛋白抑制剂的作用。在计算机模拟中,达匹韦林和达那韦韦对P-gp具有很强的亲和力,具有类似的结合自由能。达匹韦林的ΔGPB值为-38.24 kcal / mol,达拉韦韦的ΔGPB值为-36.84 kcal / mol。化合物在体外的通透性等级为替诺福韦<达鲁那韦<达匹韦林。 Caco-2细胞单层中替诺福韦的Papp为0.10±0.02×10-6 cm / s,ER =1。对于达匹韦林,Papp为32.2±3.7×10-6 cm / s,但ER = 1.3低于根据计算机分析结果预期。替诺福韦和达匹韦林的转运均不受P-gp抑制剂的影响。达那那韦的吸收渗透率(Papp = 6.4±0.9×10-6 cm / s)与浓度有关,ER = 6.3,维拉帕米将其降至1.2。与作为单一药剂给药相比,组合给药与改变通透性没有关系。总之,计算机模拟,细胞培养和基于组织的分析表明,替诺福韦不与P-gp相互作用且渗透性差,与细胞旁运输机制一致。计算机模拟预测,darunavir和dapivirine是P-gp底物,但只有darunavir在生物学模型中显示P-gp依赖性渗透性,这说明计算机模拟需要实验验证。当联合给药时,拟议的三联疗法抗逆转录病毒药物在结直肠粘膜中的分布将取决于它们明显不同的渗透性,但不是相互依赖的。
  • 【脊髓镇痛的血清素能介导及其与去甲肾上腺素能系统的相互作用。】 复制标题 收藏 收藏
    DOI:10.1097/00000542-199009000-00017 复制DOI
    作者列表:Nakagawa I,Omote K,Kitahata LM,Collins JG,Murata K
    BACKGROUND & AIMS: :Serotonin was administered intrathecally onto cat spinal cords to evaluate the pharmacology by which it suppresses noxiously evoked activity of wide-dynamic-range (WDR) neurons in the spinal dorsal horn. Doses of 500, 1,000 and 2,000 micrograms serotonin produced significant suppression of the mean noxiously evoked activity of WDR neurons in the dorsal horn of the spinal cord (21, 44, and 69% at 30 min, respectively). The dose-dependent effects were partially reversed by the intravenous administration of the serotonin antagonist methysergide (1 or 2 mg). Intravenous administration of the alpha 2-adrenergic antagonist yohimbine (0.5 or 1.0 mg/kg) produced a significant antagonism of the effects of serotonin. In contrast to the effects of methysergide and yohimbine, intravenous administration of naloxone or the alpha 1-antagonist corynanthine had no effect upon the suppressive effects of serotonin. The combination of low-dose serotonin and low-dose clonidine produced a supraadditive effect (30% at 30 min). These data support the concept that noradrenergic systems, possibly through an alpha 2-adrenergic mechanism, are involved in the modulation of spinal WDR neurons by serotonin.
    背景与目标: :5-羟色胺通过鞘内注射到猫脊髓上,以评估其抑制脊髓背角宽动态范围(WDR)神经元的有害诱发活性的药理作用。剂量为500、1,000和2,000微克的血清素可显着抑制脊髓背角中WDR神经元的平均有害诱发活性(分别在30分钟时分别为21%,44%和69%)。通过静脉内注射5-羟色胺拮抗剂美塞麦肽(1或2毫克)可部分逆转剂量依赖性作用。静脉内注射α2-肾上腺素拮抗剂育亨宾(0.5或1.0 mg / kg)对5-羟色胺的作用产生明显的拮抗作用。与甲基异麦角胺和育亨宾的作用相反,纳洛酮或α1拮抗药七氢鸟嘌呤的静脉内给药对5-羟色胺的抑制作用没有影响。低剂量5-羟色胺和低剂量可乐定的组合产生了超加和作用(30分钟时为30%)。这些数据支持以下概念:去甲肾上腺素系统可能通过α2-肾上腺素机制参与了5-羟色胺对脊髓WDR神经元的调节。

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