• 【在客户直接护理期间的临床讲师的教学活动:定性调查。】 复制标题 收藏 收藏
    DOI:10.1111/j.1365-2648.1991.tb01534.x 复制DOI
    作者列表:Morgan SA
    BACKGROUND & AIMS: :The lack of substantial research in the area of clinical teaching would suggest that this 'heart' of the nursing student's professional education has long been neglected. Employing a qualitative descriptive methodology, this study explored the teaching activities that nine clinical instructors said they implemented during the direct client care period and the teaching activities that these nine clinical instructors said they would implement in response to a specific scenario of a clinical teaching event. The unstructured interviews revealed that clinical instructors: (a) noted role modelling the greatest number of times as a teaching activity but implemented it less frequently; (b) used verbalizations in the form of telling, asking, saying, discussing or talking as the primary teaching activity in the clinical area and in response to the specific scenario; (c) do not have opportunities to see other clinical instructors teaching in the clinical area; (d) have difficulty separating teaching activities and evaluation activities; (e) are eclectic in their use of learning theories; and (f) find articulating teaching activities that they implement during the direct client care period to be a complex task.
    背景与目标: :在临床教学领域缺乏大量研究表明,护理学生的专业教育的“心脏”长期以来一直被忽略。本研究采用定性描述方法,探讨了九位临床指导员表示他们在直接就诊护理期间实施的教学活动,以及这九位临床指导员表示将针对临床教学事件的特定情况而实施的教学活动。非结构化的访谈表明,临床讲师:(a)注意到作为教学活动的榜样次数最多,但实施频率较低; (b)以讲,问,说,讨论或说话的形式进行口头表达,将其作为临床领域的主要教学活动,并根据具体情况做出反应; (c)没有机会去看临床领域的其他临床指导老师的教学; (d)难以将教学活动和评估活动分开; (e)在运用学习理论方面不拘一格; (f)发现他们在直接的客户护理期间实施的清晰的教学活动是一项复杂的任务。
  • 【在日常活动中测量姿势和运动时,新型活动监视器的验证。】 复制标题 收藏 收藏
    DOI:10.1136/bjsm.2006.030262 复制DOI
    作者列表:Grant PM,Ryan CG,Tigbe WW,Granat MH
    BACKGROUND & AIMS: BACKGROUND:Accurate measurement of physical activity patterns can be used to identify sedentary behaviour and may facilitate interventions aimed at reducing inactivity. OBJECTIVE:To evaluate the activPAL physical activity monitor as a measure of posture and motion in everyday activities using observational analysis as the criterion standard. METHODS:Wearing three activPAL monitors, 10 healthy participants performed a range of randomly assigned everyday tasks incorporating walking, standing and sitting. Each trial was captured on a digital camera and the recordings were synchronised with the activPAL. The time spent in different postures was visually classified and this was compared with the activPAL output. RESULTS:Intraclass correlation coefficients (ICC 2,1) for interdevice reliability ranged from 0.79 to 0.99. Using the Bland and Altman method, the mean percentage difference between the activPAL monitor and observation for total time spent sitting was 0.19% (limits of agreement -0.68% to 1.06%) and for total time spent upright was -0.27% (limits of agreement -1.38% to 0.84%). The mean difference for total time spent standing was 1.4% (limits of agreement -6.2% to 9.1%) and for total time spent walking was -2.0% (limits of agreement -16.1% to 12.1%). A second-by-second analysis between observer and monitor found an overall agreement of 95.9%. CONCLUSION:The activPAL activity monitor is a valid and reliable measure of posture and motion during everyday physical activities.
    背景与目标: 背景:对身体活动模式的准确测量可用于识别久坐行为,并可促进旨在减少运动量的干预措施。
    目的:以观察性分析为标准,评估activPAL身体活动监测器,以衡量其日常活动中的姿势和运动。
    方法:10名健康参与者戴着三副activPAL监视器,执行了一系列随机分配的日常任务,包括步行,站立和坐下。每个试验都在数码相机上捕获,并且记录与activPAL同步。用视觉对在不同姿势下花费的时间进行分类,并将其与activPAL输出进行比较。
    结果:设备间可靠性的类内相关系数(ICC 2,1)范围为0.79至0.99。使用Bland和Altman方法,ActivPAL监控器与观察值之间的平均差额为总坐下时间为0.19%(协议限制-0.68%至1.06%),而整个直立时间为-0.27%(协议限制) -1.38%至0.84%)。站立总花费时间的平均差异为1.4%(同意限制-6.2%至9.1%),步行花费总时间的平均差异为-2.0%(同意限制-16.1%至12.1%)。观察者和监测者之间进行的第二次分析发现,总体符合率为95.9%。
    结论:activPAL活动监测器是对日常体育活动中姿势和运动的有效且可靠的测量。
  • 【α-硫辛酸抑制糖尿病大鼠的P2X受体活性和内脏对结直肠扩张的超敏性。】 复制标题 收藏 收藏
    DOI:10.1038/s41598-017-04283-7 复制DOI
    作者列表:Hu J,Qin X,Song ZY,Yang PP,Feng Y,Sun Q,Xu GY,Zhang HH
    BACKGROUND & AIMS: :The present study was designed to investigate the roles of P2X3 receptors in dorsal root ganglion (DRG) neurons in colonic hypersensitivity and the effects of alpha-lipoic acid (ALA) on P2X3 receptor activity and colonic hypersensitivity of diabetic rats. Streptozotocin (STZ) was used to induce diabetic model. Abdominal withdrawal reflex (AWR) responding to colorectal distention (CRD) was recorded as colonic sensitivity. ATP-induced current density of colon-specific DRG (T13-L2 DRGs) neurons was measured with whole-cell patch clamp. The expression of P2X3Rs of T13-L2 DRGs was measured by western blot analysis. The results showed that AWR scores significantly increased after STZ injection. P2X3R expression and ATP current density of T13-L2 DRG neurons were enhanced in diabetic rats. Intraperitoneal injection with ALA once a day for 1 week remarkably reduced P2X3R expression and ATP current density in diabetic rats. Importantly, ALA treatment attenuated colonic hypersensitivity in diabetic rats. Our data suggest that STZ injection increases expression and function of P2X3 receptors of colon-specific DRG neurons, thus contributing to colonic hypersensitivity in diabetic rats. Administration of ALA attenuates diabetic colonic hypersensitivity, which is most likely mediated by suppressing expression and function of P2X3 receptors in DRGs of diabetic rats.
    背景与目标: :本研究旨在研究背根神经节(DRG)神经元中P2X3受体在结肠超敏中的作用以及α-硫辛酸(ALA)对糖尿病大鼠P2X3受体活性和结肠超敏性的影响。链脲佐菌素(STZ)用于诱导糖尿病模型。记录对结肠扩张(CRD)的腹部缩回反射(AWR)作为结肠敏感性。用全细胞膜片钳测量ATP诱导的结肠特异性DRG(T13-L2 DRGs)神经元的电流密度。通过蛋白质印迹分析测量T13-L2 DRG的P2X3R的表达。结果表明,注射STZ后AWR分数显着增加。 T13-L2 DRG神经元的P2X3R表达和ATP电流密度在糖尿病大鼠中增强。每天一次腹膜内注射ALA,持续1周,可显着降低糖尿病大鼠的P2X3R表达和ATP电流密度。重要的是,ALA治疗可减轻糖尿病大鼠的结肠超敏反应。我们的数据表明,STZ注射可增加结肠特异性DRG神经元的P2X3受体的表达和功能,从而促进糖尿病大鼠的结肠超敏反应。 ALA的给药减弱了糖尿病结肠的超敏反应,这很可能是通过抑制糖尿病大鼠DRG中P2X3受体的表达和功能来介导的。
  • 【线粒体:氧化还原活动和细胞窘迫控制的枢纽。】 复制标题 收藏 收藏
    DOI:10.1007/s11010-007-9520-8 复制DOI
    作者列表:Kakkar P,Singh BK
    BACKGROUND & AIMS: :In their reductionist approach in unraveling phenomena inside the cell, scientists in recent times have focused attention to mitochondria. An organelle with peculiar evolutionary history and organization, it is turning out to be an important cell survival switch. Besides controlling bioenergetics of a cell it also has its own genetic machinery which codes 37 genes. It is a major source of generation of reactive oxygen species, acts as a safety device against toxic increases of cytosolic Ca2+ and its membrane permeability transition is a critical control point in cell death. Redox status of mitochondria is important in combating oxidative stress and maintaining membrane permeability. Importance of mitochondria in deciding the response of cell to multiplicity of physiological and genetic stresses, inter-organelle communication, and ultimate cell survival is constantly being unraveled and discussed in this review. Mitochondrial events involved in apoptosis and necrotic cell death, such as activation of Bcl-2 family proteins, formation of permeability transition pore, release of cytochrome c and apoptosis inducing factors, activation of caspase cascade, and ultimate cell death is the focus of attention not only for cell biologists, but also for toxicologists in unraveling stress responses. Mutations caused by ROS to mitochondrial DNA, its inability to repair it completely and creation of a vicious cycle of mutations along with role of Bcl-2 family genes and proteins has been implicated in many diseases where mitochondrial dysfunctions play a key role. New therapeutic approaches toward targeting low molecular weight compounds to mitochondria, including antioxidants is a step toward nipping the stress in the bud.
    背景与目标: :最近,科学家们以还原论的方法揭示了细胞内部的现象,将注意力集中在线粒体上。具有独特的进化历史和组织的细胞器,事实证明它是重要的细胞存活开关。除了控制细胞的生物能,它还具有自己的遗传机制,可编码37个基因。它是产生活性氧的主要来源,是防止细胞溶质Ca2毒性增加的安全装置,其膜通透性转变是细胞死亡的关键控制点。线粒体的氧化还原状态在抵抗氧化应激和维持膜通透性方面很重要。在决定细胞对多种生理和遗传压力,细胞间通讯以及最终细胞存活的反应中,线粒体的重要性正在不断地被探讨和讨论。涉及凋亡和坏死细胞死亡的线粒体事件,例如Bcl-2家族蛋白的激活,通透性过渡孔的形成,细胞色素c和凋亡诱导因子的释放,胱天蛋白酶级联的激活以及最终细胞死亡等,不是人们关注的焦点。不仅适用于细胞生物学家,还适用于毒理学家,以阐明压力反应。 ROS引起的线粒体DNA突变,其无法完全修复,突变的恶性循环以及Bcl-2家族基因和蛋白质的作用,在许多疾病中都与线粒体功能障碍起着关键作用。将低分子量化合物靶向线粒体(包括抗氧化剂)的新治疗方法是消除发芽压力的一步。
  • 【Plantagiolides I和J,两个新的来自塔克拉(Tacca plantaginea)的withanolide糖苷,具有核因子-κB抑制和过氧化物酶体增殖物激活的受体反式激活活性。】 复制标题 收藏 收藏
    DOI:10.1248/cpb.c12-00550 复制DOI
    作者列表:Quang TH,Ngan NT,Minh CV,Kiem PV,Yen PH,Tai BH,Nhiem NX,Thao NP,Anh Hle T,Luyen BT,Yang SY,Kim YH
    BACKGROUND & AIMS: :A novel withanolide glucoside, plantagiolide I (1), a new withanolide glucoside, plantagiolide J (2), and six known compounds (3-8) were isolated from the whole plant of Tacca plantaginea. Their structures were determined by spectroscopic and chemical methods. Compound 3 significantly inhibited tumor necrosis factor alpha (TNFα)-induced nuclear factor-kappaB (NF-κB) transcriptional activity in HepG2 cells in a dose-dependent manner, with IC(50) values of 9.0 µM. Compounds 1-8 enhanced the transcriptional activity of peroxisome proliferator-activated receptors (PPARs) in a dose-dependent manner, with EC(50) values ranging from 1.6 to 49.7 µM. In addition, the transactivational effects of compounds 1-8 on three individual PPAR subtypes, including PPARα, β(δ), and γ were evaluated. Compounds 1-8 significantly activated the transcriptional activity of PPARβ(δ), with EC(50) values in a ranging from 4.1 to 29.6 µM. These results provide scientific support for the use of T. plantaginea and its components for the prevention and treatment of inflammatory and metabolic diseases.
    背景与目标: :从塔克拉(Tacca plantaginea)的整个植物中分离出一种新的withanolide葡糖苷植物plant内酯I(1),一种新的withanolide葡糖苷,plantagiolide J(2)和六种已知化合物(3-8)。通过光谱和化学方法确定它们的结构。化合物3剂量依赖性地显着抑制HepG2细胞中肿瘤坏死因子α(TNFα)诱导的核因子-κB(NF-κB)转录活性,IC(50)值为9.0μM。化合物1-8以剂量依赖的方式增强了过氧化物酶体增殖物激活受体(PPAR)的转录活性,EC(50)值在1.6至49.7µM之间。另外,评价了化合物1-8对三种单独的PPAR亚型,包括PPARα,β(δ)和γ的反式激活作用。化合物1-8显着激活PPARβ(δ)的转录活性,EC(50)值在4.1至29.6µM之间。这些结果为植物假单胞菌及其成分用于炎性和代谢性疾病的预防和治疗提供了科学依据。
  • 【排尿利尿剂的研究。 I.黄嘌呤氧基氧乙酸和二氢呋喃蒽酮-2-羧酸的合成和活性。】 复制标题 收藏 收藏
    DOI:10.1248/cpb.38.1266 复制DOI
    作者列表:Sato H,Dan T,Onuma E,Tanaka H,Koga H
    BACKGROUND & AIMS: :A series of substituted xanthonyloxyacetic acids (5 and 6), 1,2-dihydrofuro[2,3-c]xanthone-2-carboxylic acids (7) and 2,3-dihydrofuro[3,2-b]xanthone-2-carboxylic acids (8) were synthesized and tested for diuretic and uricosuric activities in rats. Most of the xanthon-3-yloxyacetic acids (5) and 7 showed potent diuretic activities, while 8 had lower activities. Uricosuric activities were found in 5c, 5f, 5k, 5m, 5o, 5p, 5r, 7m, 7p and 8q.
    背景与目标: :一系列取代的氧杂蒽氧基氧乙酸(5和6),1,2-二氢呋喃[2,3-c]蒽酮-2-羧酸(7)和2,3-二氢呋喃[3,2-b]蒽酮-2合成了α-羧酸(8)并测试了大鼠的利尿和尿尿排尿活性。多数x吨-3-基氧基乙酸(5)和7显示出强效的利尿活性,而8种则具有较低的利尿活性。在5c,5f,5k,5m,5o,5p,5r,7m,7p和8q中发现了泌尿外科活动。
  • 【苄腺嘌呤对吸收的黑克子叶线粒体活性发展的影响。】 复制标题 收藏 收藏
    DOI:10.1016/S0176-1617(84)80093-0 复制DOI
    作者列表:Morohashi Y
    BACKGROUND & AIMS: :The development of mitochondria was followed in black gram cotyledons cultured on filter paper wetted with water or benzyladenine solution. Treatment with benzyladenine brought about an increase in activities of some mitochondrial enzymes and in respiratory activities of mitochondria. Cycloheximide did not inhibit the increase, although it almost completely inhibited the incorporation of (14)C-leucine into mitochondrial protein. It was inferred that the increase in mitochondrial activity by benzyladenine-treatment was not due to biogenesis of mitochondria but due to an acceleration of activation processes in pre-existing mitochondria. The respiratory control ratio of mitochondria from benzyladenine-treated cotyledons was lower than that of mitochondria from untreated ones. It was also suggested that benzyladenine brought about some qualitative changes in mitochondrial activities.
    背景与目标: :在用水或苄基腺嘌呤溶液润湿的滤纸上培养的黑克子叶中追踪线粒体的发育。用苄基腺嘌呤治疗导致某些线粒体酶活性和线粒体呼吸活性增加。环己酰亚胺没有抑制这种增加,尽管它几乎完全抑制了(14)C-亮氨酸掺入线粒体蛋白中。据推测,通过苄腺嘌呤处理增加的线粒体活性不是由于线粒体的生物发生,而是由于预先存在的线粒体中活化过程的加速。苄腺嘌呤处理的子叶的线粒体呼吸控制率低于未处理的子叶的线粒体呼吸控制率。还建议苄基腺嘌呤在线粒体活性方面带来一些质的变化。
  • 【非洲传统草药中的有丝分裂活动(第二部分)。】 复制标题 收藏 收藏
    DOI:10.1016/S0944-7113(96)80078-X 复制DOI
    作者列表:Tachibana Y,Kato A,Nishiyama Y,Ikemi M,Ohoka K,Kawanishi K,Juma FD,Ngángá JN,Mathenge SG
    BACKGROUND & AIMS: :Mitogenic activities in African traditional herbal medicines were examined on human peripheral blood lymphocytes and mouse spleen cells using protein fractions obtained from their extracts by precipitation with ammonium sulfate. Target specificity for these mitogens was investigated by using isolated T cells and lymphocytes from athymic nude mice. Among 20 plants investigated, potent mitogenic activities for both human and mouse lymphocytes were found in 7 plants: Monanthotaxis sp. (Annonaceae), Uvaria lucida (Annonaceae), Maytenus buchananii (Celastraceae), Lonchocarpus bussei (Leguminosae), Phytolacca dodecandra (Phytolaccaceae), Phytolacca octandra (Phytolaccaceae), and Toddalia asiatica (Rutaceae). The U. lucida stem demonstrated the highest activity among all and induced mitogenesis both in human and mouse isolated T cells, but not in lymphocytes from athymic nude mice.
    背景与目标: :使用硫酸铵沉淀法从其提取物中获得的蛋白质馏分,检查了非洲传统草药对人外周血淋巴细胞和小鼠脾细胞的促有丝分裂活性。通过使用来自无胸腺裸鼠的分离的T细胞和淋巴细胞,研究了这些促分裂原的靶标特异性。在研究的20种植物中,在7种植物中发现了对人和小鼠淋巴细胞均有效的促有丝分裂活性:Monanthotaxis sp。 (Annonaceae),Uluca lucida(Annonaceae),Maytenus buchananii(Celastraceae),Lonchocarpus bussei(Leguminosae),Phytolacca dodecandra(Phytolaccaceae),Phytolacca octandra(Phytolaccaceae)和Toddalia asiatica。在人和小鼠分离的T细胞中,U。lucida茎表现出最高的活性并诱导有丝分裂发生,而无胸腺裸鼠的淋巴细胞则没有。
  • 【从东方红腹蟾蜍Bombina Orientalis的皮肤分泌物中发现两种具有抗菌和抗癌活性的Bombinin肽。】 复制标题 收藏 收藏
    DOI:10.1111/cbdd.13055 复制DOI
    作者列表:Zhou C,Wang Z,Peng X,Liu Y,Lin Y,Zhang Z,Qiu Y,Jin M,Wang R,Kong D
    BACKGROUND & AIMS: :Amphibian skin secretions are known to contain numerous peptides with a large array of biological activities. Bombinins are a group of amphibian-derived peptides with broad spectrum antimicrobial activities that have been only identified from the ancient toad species, Bombina. In this study, we described the identification and characterization of a novel bombinin precursor which encoded a bombinin-like peptide (BLP-7) and a novel bombinin H-type peptide (named as Bombinin H-BO) from the skin secretion of Oriental fire-bellied toad, Bombina orientalis. The primary structures of both mature peptides were determined by combinations of molecular cloning of peptide precursor-encoding cDNAs and mass spectrometry techniques. Secondary structure prediction revealed that both peptides had cationic amphipathic α-helical structural features. The synthetic replicate of BLP-7 displayed more potent antimicrobial activity than Bombinin H-BO against Gram-positive and Gram-negative bacteria and yeast. Also, in vitro antitumour assay showed that both peptides possessed obvious antiproliferative activity on three human hepatoma cells (Hep G2/SK-HEP-1/Huh7) at the non-toxic doses. These results indicate the peptide family of bombinins could be a potential source of drug candidates for anti-infection and anticancer therapy.
    背景与目标: 已知两栖动物的皮肤分泌物中含有许多具有多种生物活性的肽。 Bombinins是一组具有广谱抗菌活性的两栖动物衍生肽,仅从古老的蟾蜍物种Bombina中鉴定出来。在这项研究中,我们描述了一种从东方火的皮肤分泌物中鉴定出一种新的蛙新蛋白前体的鉴定和表征,该前体编码了一种蛙新蛋白样肽(BLP-7)和一种新颖的蛙新蛋白H型肽(称为蛙蛋白H-BO)腹蟾蜍,Bombina Orientalis。通过结合肽前体编码cDNA的分子克隆和质谱技术确定两种成熟肽的一级结构。二级结构预测表明,两种肽均具有阳离子两亲性α-螺旋结构特征。与Bombinin H-BO相比,BLP-7的合成复制品对革兰氏阳性和革兰氏阴性细菌和酵母菌显示出更强的抗菌活性。同样,体外抗肿瘤试验表明,两种肽均以无毒剂量对三种人肝癌细胞(Hep G2 / SK-HEP-1 / Huh7)具有明显的抗增殖活性。这些结果表明,蛙皮素的肽家族可能是抗感染和抗癌治疗候选药物的潜在来源。
  • 【甘草绒毛根的水提取物在小鼠中的镇痛和抗炎活性。】 复制标题 收藏 收藏
    DOI:10.1016/j.jep.2007.05.024 复制DOI
    作者列表:Lu TC,Ko YZ,Huang HW,Hung YC,Lin YC,Peng WH
    BACKGROUND & AIMS: :In the present study, we have investigated the analgesic effect of the aqueous extract of the root of Glycine tomentella (AGT) using models of acetic acid-induced writhing response and formalin test, the anti-inflammatory effect of AGT using model of lambda-carrageenan-induced paw edema. In order to investigate the anti-inflammatory mechanism of AGT, we have detected the activities of glutathione peroxidase (GPx) and glutathione reductase (GRx) in the liver and the levels of malondialdehyde (MDA) and NO in the edema paw. In the analgesic test, AGT (0.5 and 1.0 g/kg) decreased the acetic acid-induced writhing response and the licking time on the late phase in the formalin test. In the anti-inflammatory test, AGT (0.5 and 1.0 g/kg) decreased the paw edema at the third, fourth, fifth and sixth hour after lambda-carrageenan administration, and increased the activities of SOD, GPx and GRx in the liver tissue and decreased the MDA level in the edema paw at the third hour after lambda-carrageenan injection. However, AGT could not affect the NO level which induced by lambda-carrageenan. These results suggested that AGT possessed analgesic and anti-inflammatory effects. The anti-inflammatory mechanism of AGT might be related to the decrease in the level of MDA in the edema paw via increasing the activities of SOD, GPx and GRx in the liver.
    背景与目标: :在本研究中,我们使用乙酸诱导的扭体反应模型和福尔马林试验研究了甘草绒毛(AGT)根的水提取物的镇痛作用,使用λ-模型研究了AGT的抗炎作用。角叉菜胶诱发的爪水肿。为了研究AGT的抗炎机制,我们检测了肝中谷胱甘肽过氧化物酶(GPx)和谷胱甘肽还原酶(GRx)的活性以及水肿爪中丙二醛(MDA)和NO的水平。在镇痛试验中,在福尔马林试验的后期,AGT(0.5和1.0 g / kg)减少了乙酸诱导的扭体反应和舔食时间。在抗炎试验中,AGT(0.5和1.0 g / kg)减少了λ-角叉菜胶给药后第三,第四,第五和第六小时的爪水肿,并增加了肝脏组织中SOD,GPx和GRx的活性并在注射λ-角叉菜胶后的第三小时降低了水肿爪中的MDA水平。然而,AGT不能影响由λ-角叉菜胶诱导的NO水平。这些结果表明,AGT具有镇痛和抗炎作用。 AGT的抗炎机制可能与通过增加肝脏中SOD,GPx和GRx的活性而降低水肿爪中MDA的水平有关。
  • 【域特定的模拟磷酸化突变允许解剖不同的蛋白激酶C(PKC)同型触发的RNA结合蛋白HuR的活动。】 复制标题 收藏 收藏
    DOI:10.1016/j.cellsig.2013.08.003 复制DOI
    作者列表:Schulz S,Doller A,Pendini NR,Wilce JA,Pfeilschifter J,Eberhardt W
    BACKGROUND & AIMS: :The ubiquitous mRNA binding protein human antigen R (HuR) participates in the post-transcriptional regulation of many AU-rich element (ARE)-bearing mRNAs. Previously, by using in vitro kinase assay, we have identified serines (Ser) 158, 221 and 318 as targets of protein kinase C (PKC)-triggered phosphorylation. In this study, we tested whether GFP- or GST-tagged HuR constructs bearing a phosphomimetic Ser (S)-to-Asp (D) substitution at the different PKC target sites, would affect different HuR functions including HuR nucleo-cytoplasmic redistribution and binding to different types of ARE-containing mRNAs. The phosphomimetic GFP-tagged HuR protein bearing a phosphomimetic substitution in the hinge region of HuR (HuR-S221D) showed an increased cytoplasmic abundance when compared to wild-type HuR. Conversely, data from in vitro kinase assay and electrophoretic mobility shift assay (EMSA), implicates that phosphorylation at Ser 221 is not relevant for mRNA binding of HuR. Quantification of in vitro binding affinities of GST-tagged wild-type HuR and corresponding HuR proteins bearing a phosphomimetic substitution in either RRM2 (HuR-S158D) or in RRM3 (HuR-S318D) by microscale thermophoresis (MST) indicates a specific binding of wild-type HuR to type I, II or type III-ARE-oligonucleotides in the high nanomolar range. Interestingly, phosphomimetic mutation at position 158 or 318 had a negative influence on HuR binding to type I- and type II-ARE-mRNAs whereas it significantly enhanced HuR affinity to a type III-ARE substrate. Our data suggest that differential phosphorylation of HuR by PKCs at different HuR domains coordinates subcellular HuR distribution and leads to a preferential binding to U-rich bearing target mRNA.
    背景与目标: :普遍存在的mRNA结合蛋白人类抗原R(HuR)参与许多富含AU元素(ARE)的mRNA的转录后调控。以前,通过使用体外激酶测定,我们已经将丝氨酸(Ser)158、221和318确定为蛋白激酶C(PKC)触发的磷酸化的靶标。在这项研究中,我们测试了在不同的PKC目标位点上带有磷酸仿Ser(S)-Asp(D)取代的GFP标记或GST标记的HuR构建体是否会影响不同的HuR功能,包括HuR核质重分布和结合对不同类型的含有ARE的mRNA的表达。与野生型HuR相比,在HuR的铰链区(HuR-S221D)带有磷酸模拟取代的磷酸化GFP标记的HuR蛋白显示出增加的细胞质丰度。相反,来自体外激酶测定和电泳迁移率变动测定(EMSA)的数据暗示Ser 221的磷酸化与HuR的mRNA结合无关。定量标记GST标签的野生型HuR和相应的在磷酸RRM2(HuR-S158D)或RRM3(HuR-S318D)中具有磷酸模拟取代作用的HuR蛋白的体外结合亲和力表明通过微型热电泳(MST) -在高纳摩尔范围内将HuR型转变为I,II或III型-ARE-寡核苷酸。有趣的是,位置158或318处的磷酸模拟突变对HuR与I型和II型ARE-mRNA的结合具有负面影响,而它显着增强了HuR对III型ARE底物的亲和力。我们的数据表明,PKCs在不同的HuR域上对HuR的磷酸化差异会协调亚细胞HuR的分布,并导致与富含U的靶标mRNA的优先结合。
  • 【评价蜜糖腰果苹果花蜜的抗氧化和诱变活性。】 复制标题 收藏 收藏
    DOI:10.1016/j.fct.2013.08.026 复制DOI
    作者列表:da Silva RA,Dihl RR,Nascimento e Santos D,de Abreu BR,de Lima A,de Andrade HH,Lehmann M
    BACKGROUND & AIMS: :In vitro chemical properties and antioxidant potential and in vivo mutagenic activity of honey-sweetened cashew apple nectar (HSCAN), a beverage produced from the cashew pseudo-fruit (Anacardium occidentale L.) and of its constituents were assessed. Analytical procedures were carried out to investigate the honey used in the HSCAN preparation, and the results observed are in accordance with Brazilian legal regulations, except for diastase number. HSCAN and pulp were investigated for ascorbic acid, carotenoid, anthocyanin and total phenolic contents, and both showed high acid ascorbic concentrations. Antioxidant capacity using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and/or β-carotene/linoleic acid systems were applied and demonstrated a weak antioxidant capacity of honey and HSCAN, but cashew apple pulp demonstrated high antioxidant capacity. A weakly positive mutagenic effect of cashew pulp 20% was observed using the somatic mutation and recombination test (SMART) in Drosophila melanogaster only in the high-bioactivation (HB) cross. On the contrary, HSCAN was not mutagenic in both standard and high bioactivation crosses. HSCAN exhibited slight antioxidant activity, which could be associated with the high amount of ascorbic acid found in the samples evaluated. The beverage prepared did not induce DNA damage in somatic cells of D. melanogaster, which means that it is neither mutagenic nor recombinagenic in this test system.
    背景与目标: :对蜂蜜加糖的腰果苹果花蜜(HSCAN)的体外化学性质,抗氧化剂潜力和体内诱变活性进行了评估,该饮料是由腰果假果(Anacardium occidentale L.)生产的饮料及其成分。进行了分析程序以调查HSCAN制剂中使用的蜂蜜,观察到的结果符合巴西法律法规,但发乳酶数量除外。对HSCAN和纸浆进行了抗坏血酸,类胡萝卜素,花色苷和总酚含量的调查,结果均显示出较高的酸性抗坏血酸浓度。应用了使用2,2-二苯基-1-吡啶并肼基(DPPH)和/或β-胡萝卜素/亚油酸体系的抗氧化能力,证明了蜂蜜和HSCAN的抗氧化能力较弱,但腰果苹果浆显示出较高的抗氧化能力。仅在高生物激活(HB)杂交中,使用果蝇果蝇的体细胞突变和重组试验(SMART)观察到了腰果果肉20%的弱阳性诱变作用。相反,HSCAN在标准和高生物激活杂交中均不致突变。 HSCAN表现出轻微的抗氧化活性,这可能与所评估样品中发现的大量抗坏血酸有关。所制备的饮料不会在黑腹果蝇的体细胞中引起DNA损伤,这意味着该饮料在该测试系统中既不诱变也不重组。
  • 【EFSA在其成立的头十年中在转基因生物(GMO)风险评估方面的科学活动和成就:回顾与展望。】 复制标题 收藏 收藏
    DOI:10.1007/s11248-013-9741-4 复制DOI
    作者列表:Devos Y,Aguilera J,Diveki Z,Gomes A,Liu Y,Paoletti C,du Jardin P,Herman L,Perry JN,Waigmann E
    BACKGROUND & AIMS: :Genetically modified organisms (GMOs) and derived food and feed products are subject to a risk analysis and regulatory approval before they can enter the market in the European Union (EU). In this risk analysis process, the role of the European Food Safety Authority (EFSA), which was created in 2002 in response to multiple food crises, is to independently assess and provide scientific advice to risk managers on any possible risks that the use of GMOs may pose to human and animal health and the environment. EFSA's scientific advice is elaborated by its GMO Panel with the scientific support of several working groups and EFSA's GMO Unit. This review presents EFSA's scientific activities and highlights its achievements on the risk assessment of GMOs for the first 10 years of its existence. Since 2002, EFSA has issued 69 scientific opinions on genetically modified (GM) plant market registration applications, of which 62 for import and processing for food and feed uses, six for cultivation and one for the use of pollen (as or in food), and 19 scientific opinions on applications for marketing products made with GM microorganisms. Several guidelines for the risk assessment of GM plants, GM microorganisms and GM animals, as well as on specific issues such as post-market environmental monitoring (PMEM) were elaborated. EFSA also provided scientific advice upon request of the European Commission on safeguard clause and emergency measures invoked by EU Member States, annual PMEM reports, the potential risks of new biotechnology-based plant breeding techniques, evaluations of previously assessed GMOs in the light of new scientific publications, and the use of antibiotic resistance marker genes in GM plants. Future challenges relevant to the risk assessment of GMOs are discussed. EFSA's risk assessments of GMO applications ensure that data are analysed and presented in a way that facilitates scientifically sound decisions that protect human and animal health and the environment.
    背景与目标: :转基因生物(GMO)以及衍生的食品和饲料产品在进入欧盟(EU)市场之前,必须经过风险分析和监管批准。在此风险分析过程中,于2002年为应对多种食品危机而成立的欧洲食品安全局(EFSA)的职责是就使用GMO的任何可能风险进行独立评估并向风险管理者提供科学建议可能对人类和动物健康以及环境构成影响。 EFSA的GMO小组在多个工作组和EFSA的GMO部门的科学支持下,详细阐述了EFSA的科学建议。这篇综述介绍了EFSA的科学活动,并着重介绍了EFSA存在前10年在转基因生物风险评估方面所取得的成就。自2002年以来,欧洲食品安全局(EFSA)就转基因植物市场注册申请发布了69项科学意见,其中62项用于食品和饲料的进口和加工,六种用于种植,一种用于花粉(作为食品中或食品中),关于应用转基因微生物制成的产品的销售方面有19项科学见解。拟定了几项关于转基因植物,转基因微生物和转基因动物风险评估的指南,以及针对诸如上市后环境监测(PMEM)等特定问题的风险评估。 EFSA还应欧洲委员会的要求,就欧盟成员国援引的保障条款和紧急措施,PMEM年度报告,基于生物技术的新型植物育种技术的潜在风险,根据新的科学方法对先前评估的转基因生物进行评估提供了科学建议出版物,以及转基因植物中抗生素抗性标记基因的使用。讨论了与转基因生物风险评估有关的未来挑战。 EFSA对转基因生物的风险评估可确保对数据进行分析和呈现,从而促进科学合理的决策,从而保护人类和动物健康及环境。
  • 【辣根过氧化物酶His42-> Glu或Gln突变体的催化活性和结构性质。】 复制标题 收藏 收藏
    DOI:10.1021/bi970906q 复制DOI
    作者列表:Tanaka M,Ishimori K,Mukai M,Kitagawa T,Morishima I
    BACKGROUND & AIMS: The distal histidine (His) is highly conserved in peroxidases and has been considered to play a major role as a general acid-base catalyst for peroxidase reaction cycle. Recently, however, the X-ray structure of chloroperoxidase from the marine fungus Caldariomyces fumago has revealed that a glutamic acid is located at the position where most of the peroxidase has a histidine residue, suggesting that the carboxyl group in the glutamic acid (Glu) can also assist cleavage of an O-O bond in peroxides [Sundaramoorthy, M., Terner, J., & Poulos, T. L. (1995) Structure 3, 1367-1377]. In order to investigate catalytic roles of the glutamic acid at the distal cavity, two horseradish peroxidase mutants were prepared, in which the distal His42 has been replaced by Glu (H42E) or Gln (H42Q). The formation rate of compound I in the H42E mutant was significantly greater than that for the H42Q mutant, indicating that the distal Glu can play a role as a general acid-base catalyst. However, the peroxidase activity of the H42E mutant was still lower, compared to that for native enzyme. On the basis of the CD, resonance Raman, and EPR spectra, it was suggested that the basicity of the distal Glu is lower than that of the distal His and the position of the distal Glu is not fixed at the optimal position as a catalytic amino acid residue, although no prominent structural changes around heme environment were detected. The less basicity and improper positioning of the distal Glu would destabilize the heme-H2O2-distal Glu ternary intermediate for the peroxidase reaction. Another characteristic feature in the mutants was the enhancement of the peroxygenase activity. Since the peroxygenase activity was remarkably enhanced in the H42E mutant, the distal Glu is also crucial to facilitate the peroxygenase activity as well as the enlarged distal cavity caused by the amino acid substitution. These observations indicate that the distal amino acid residue is essential for function of peroxidases and subtle conformational changes around the distal cavity would control the catalytic reactions in peroxidase.

    背景与目标: 远端组氨酸(His)在过氧化物酶中高度保守,并被认为是过氧化物酶反应周期中通用的酸碱催化剂起着主要作用。然而,最近,来自海洋真菌Cumdariamyces fumago的氯过氧化物酶的X射线结构表明,谷氨酸位于大多数过氧化物酶具有组氨酸残基的位置,这表明谷氨酸(Glu)中的羧基还可在过氧化物中切割OO键[Sundaramoorthy,M.,Terner,J。,&Poulos,TL(1995)Structure 3,1367-1377]。为了研究谷氨酸在远端腔中的催化作用,制备了两个辣根过氧化物酶突变体,其中His42的远端已被Glu(H42E)或Gln(H42Q)取代。 H42E突变体中化合物I的形成速率显着大于H42Q突变体中化合物I的形成速率,表明远端Glu可以充当一般的酸碱催化剂。但是,与天然酶相比,H42E突变体的过氧化物酶活性仍然较低。根据CD,共振拉曼光谱和EPR光谱,表明远侧Glu的碱性低于远侧His的碱性,并且远侧Glu的位置未固定在作为催化氨基的最佳位置酸残基,尽管在血红素环境周围未发现明显的结构变化。远端Glu的碱性较低和定位不当将使过氧化物酶反应的血红素-H2O2-远端Glu三元中间体不稳定。突变体的另一个特征是过氧化酶活性的增强。由于过氧化酶活性在H42E突变体中显着增强,因此远端Glu对于促进过氧化酶活性以及由氨基酸取代引起的远端腔增大也至关重要。这些观察结果表明,远端氨基酸残基对于过氧化物酶的功能是必不可少的,并且远端腔周围微妙的构象变化将控制过氧化物酶中的催化反应。

  • 【槐槐喹诺唑烷生物碱及其抗炎活性。】 复制标题 收藏 收藏
    DOI:10.1016/j.fitote.2019.104391 复制DOI
    作者列表:He LJ,Liu JS,Luo D,Zheng YR,Zhang YB,Wang GC,Li YL
    BACKGROUND & AIMS: :Two new quinolizidine-based alkaloids (2 and 12), along with ten known ones (1, 3-11) were isolated from the roots of S. tonkinensis. Their structures were determined by spectroscopic data (including NMR, MS, IR, and UV), X-ray single crystal diffraction, electronic circular dichroism analyses (ECD), and comparing with related literatures. Compounds 1, 3-12 at non-toxic concentrations exhibited potent anti-inflammatory activities according to in vitro and in vivo anti-inflammatory tests. Among them, (-)-anagyrine (4), sophocarpine (8), 14β-hydroxymatrine (10), and 7β-sophoramine (12) showed more potent in vitro anti-inflammatory activities, and 5α,14β-dihydroxymatrine (2), (-)-anagyrine (4), sophocarpine (8), and 5α-hydroxymatrine (9) exhibited better in vivo anti-inflammatory effects.
    背景与目标: :从S. tonkinensis的根中分离出两种新的基于喹喔啉的生物碱(2和12),以及十种已知的生物碱(1、3-11)。它们的结构由光谱数据(包括NMR,MS,IR和UV),X射线单晶衍射,电子圆二色性分析(ECD)以及与相关文献进行比较来确定。根据体外和体内抗炎试验,无毒浓度的化合物1、3-12表现出有效的抗炎活性。其中,(-)-Anagyrine(4),Sophocarpine(8),14β-hydroxymatrine(10)和7β-sophoramine(12)表现出更强的体外抗炎活性,而5α,14β-dihydroxymatrine(2) ,(-)-Anagyrine(4),Sophocarpine(8)和5α-hydroxymatrine(9)表现出更好的体内抗炎作用。

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