• 【促胰液素PulD的C末端结构域包含其同源伴侣PulS的结合位点,并赋予PulS对pIVf1功能的依赖性。】 复制标题 收藏 收藏
    DOI:10.1046/j.1365-2958.1997.3531727.x 复制DOI
    作者列表:Daefler S,Guilvout I,Hardie KR,Pugsley AP,Russel M
    BACKGROUND & AIMS: :Related outer membrane proteins, termed secretins, participate in the secretion of macromolecules across the outer membrane of many Gram-negative bacteria. In the pullulanase-secretion system, PulS, an outer membrane-associated lipoprotein, is required both for the integrity and the proper outer membrane localization of the PulD secretin. Here we show that the PulS-binding site is located within the C-terminal 65 residues of PulD. Addition of this domain to the filamentous phage secretin, pIV, or to the unrelated maltose-binding protein rendered both proteins dependent on PulS for stability. A chimeric protein composed of bacteriophage f1 pIV and the C-terminal domain of PuID required properly localized PulS to support phage assembly. An in vivo complex formed between the pIV-PulD65 chimera and PulS was detected by co-immunoprecipitation and by affinity chromatography.
    背景与目标: :相关的外膜蛋白,称为促胰液素,参与许多革兰氏阴性细菌的外膜大分子的分泌。在支链淀粉酶分泌系统中,PulS是一种与外膜相关的脂蛋白,是PulD促胰液素的完整性和正确的外膜定位所必需的。在这里,我们显示PulS结合位点位于PulD的C末端65个残基内。该结构域添加到丝状噬菌体分泌蛋白,pIV或无关的麦芽糖结合蛋白上,使得这两种蛋白都依赖于PulS进行稳定性。由噬菌体f1 pIV和PuID的C末端结构域组成的嵌合蛋白需要适当定位的PulS才能支持噬菌体装配。通过共免疫沉淀和亲和色谱法检测到了pIV-PulD65嵌合体和PulS之间形成的体内复合物。
  • 【等轴测肌力的历史依赖性:先前拉伸或缩短幅度的影响。】 复制标题 收藏 收藏
    DOI:10.1016/j.jbiomech.2006.06.014 复制DOI
    作者列表:Bullimore SR,Leonard TR,Rassier DE,Herzog W
    BACKGROUND & AIMS: :It is well-recognised that steady-state isometric muscle force is decreased following active shortening (force depression, FD) and increased following active stretch (force enhancement, FE). It has also been demonstrated that passive muscle force is increased following active stretch (passive FE). Several studies have reported that FD increases with shortening amplitude and that FE and passive FE increase with stretch amplitude. Here, we investigate whether these trends continue with further increases in shortening or stretch amplitude. Experiments were performed using in situ cat soleus muscles (n=8 for FD; n=7 for FE and passive FE). FD, FE and passive FE were measured after shortening or stretch contractions that covered as wide a range of amplitudes as practically possible without damaging the muscles. FD increased approximately linearly with shortening amplitude, over the full range of amplitudes investigated. This is consistent with the hypothesis that FD arises from a stress-induced inhibition of crossbridges. FE increased with stretch amplitude only up to a point, and then levelled off. Passive FE, and the transient increase in force at the end of stretch, showed relationships to stretch amplitude that were qualitatively very similar to the relationship for FE, increasing only until the same critical stretch amplitude had been reached. We conclude that FE and passive FE do not increase with stretch amplitude under all circumstances. This finding has important consequences for determining the mechanisms underlying FE and passive FE because any mechanism that is proposed to explain them must be able to predict it.
    背景与目标: :众所周知,稳态等距肌肉力量在主动缩短(力量压迫,FD)后降低,而在主动伸展(力量增强,FE)后增加。还已经证明,主动拉伸(被动FE)后,被动肌肉的力量会增加。几项研究报告说,FD随着幅度的减小而增加,而FE和被动FE随拉伸幅度而增加。在这里,我们调查这些趋势是否继续缩短或拉伸幅度的进一步增加。使用原位猫的比目鱼肌进行实验(FD为n = 8; FE和被动FE为n = 7)。 FD,FE和被动FE是在收缩或拉伸收缩后测量的,收缩或拉伸收缩实际上覆盖了尽可能宽的幅度范围,而不会损坏肌肉。在所研究的整个振幅范围内,FD随振幅的减小而近似线性地增加。这与FD由应力诱导的跨桥抑制作用引起的假设相一致。 FE随拉伸幅度仅增加到一个点,然后趋于平稳。被动有限元,以及拉伸结束时力的瞬时增加,表明与拉伸幅度的关系在质量上与有限元的关系非常相似,仅在达到相同的临界拉伸幅度之前才增加。我们得出结论,在所有情况下,有限元和无源有限元都不会随拉伸幅度的增加而增加。这一发现对确定有限元和被动有限元的机制具有重要意义,因为提议用来解释它们的任何机制都必须能够对其进行预测。
  • 【伤亡:海洛因使用者进入排毒过程中发生的战斗,骨折和机动车事故。】 复制标题 收藏 收藏
    DOI:10.1016/j.drugalcdep.2017.04.009 复制DOI
    作者列表:Stein MD,Anderson BJ,Bailey GL
    BACKGROUND & AIMS: BACKGROUND:The lives of persons who use illicit substances are filled with physical adversities and negative outcomes. OBJECTIVES:The purpose of this study was to determine: 1) the frequency of substance-related fights, fractures, and driving accidents in the past year among heroin users entering an inpatient detoxification program, and 2) to determine demographic and recent substance use factors associated with the most common of these physical traumas. METHODS:Between May 2015 and December 2015, we surveyed 433 persons entering a short-term inpatient detoxification program that reported heroin use in the last month and recorded their experiences of physical traumas in the last year. RESULTS:Among participants (72% male; 74% heroin injectors), more than a quarter (28.6%) reported a substance-related fight in the past year. Multivariate modeling revealed cocaine use, hazardous alcohol use, and younger age were significantly associated with fighting, but gender was not. Forty-five (10.4%) persons reported a fracture in the past year, with 64% of fractures related to a substance-related fall or fight. Additionally, 9.0% reported being a driver in a car accident after drinking or using drugs in the past year. Trauma rates were not significantly different from a contemporaneous cohort seeking alcohol detoxification at the same facility. CONCLUSION:Heroin users, both men and women, lead physically traumatic lives, interrupted by interpersonal violence, falls, fractures, and motor vehicle accidents.
    背景与目标: 背景:使用非法药物的人的生活充满了身体上的逆境和负面结果。
    目的:本研究的目的是确定:1​​)参加住院排毒计划的海洛因使用者在过去一年中与药物有关的打架,骨折和驾驶事故的频率,以及2)确定人口统计资料和近期的药物使用因素与这些身体创伤中最常见的疾病相关。
    方法:2015年5月至2015年12月,我们调查了433名进入短期住院排毒计划的人,他们报告了最近一个月的海洛因使用情况,并记录了他们去年的身体创伤经历。
    结果:在过去的一年中,参与者中(72%的男性; 74%的海洛因注射器)中有超过四分之一(28.6%)的人报告了与毒品有关的斗争。多变量建模显示,可卡因的使用,有害酒精的使用以及年龄的降低与打架有显着联系,而性别却没有。在过去的一年中,有四十五(10.4%)人报告了骨折,其中64%的骨折与物质相关的摔倒或打架有关。此外,在过去一年中,有9.0%的人报告是在喝酒或吸毒后发生车祸的驾驶员。创伤率与同期在同一机构寻求戒毒的队列没有显着差异。
    结论:无论是男性还是女性,使用海洛因的人都遭受身体创伤,被人际暴力,跌倒,骨折和机动车事故打断。
  • 【阿立哌唑用于治疗甲基苯丙胺依赖:一项随机,双盲,安慰剂对照试验。】 复制标题 收藏 收藏
    DOI:10.1111/add.12073 复制DOI
    作者列表:Coffin PO,Santos GM,Das M,Santos DM,Huffaker S,Matheson T,Gasper J,Vittinghoff E,Colfax GN
    BACKGROUND & AIMS: AIMS:To test aripiprazole for efficacy in decreasing use in methamphetamine-dependent adults, compared to placebo. DESIGN:Participants were randomized to receive 12 weeks of aripiprazole or placebo, with a 3-month follow-up and a platform of weekly 30-minute substance abuse counseling. SETTING:The trial was conducted from January 2009 to March 2012 at the San Francisco Department of Public Health. PARTICIPANTS:Ninety actively using, methamphetamine-dependent, sexually active adults were recruited from community venues. MEASUREMENTS:The primary outcome was regression estimated reductions in weekly methamphetamine-positive urines. Secondary outcomes were study medication adherence [by self-report and medication event monitoring systems (MEMS)], sexual risk behavior and abstinence from methamphetamine. FINDINGS:Participant mean age was 38.7 years, 87.8% were male, 50.0% white, 18.9% African American, and 16.7% Latino. Eighty-three per cent of follow-up visits and final visits were completed. By intent-to-treat, participants assigned to aripiprazole had similar reductions in methamphetamine-positive urines as participants assigned to placebo [risk ratio (RR) 0.88, 95% confidence interval (CI): 0.66-1.19, P = 0.41]. Urine positivity declined from 73% (33 of 45 participants) to 45% (18 of 40) in the placebo arm and from 77% (34 of 44) to 44% (20 of 35) in the aripiprazole arm. Adherence by MEMS and self-report was 42 and 74%, respectively, with no significant difference between arms (MEMS P = 0.31; self-report P = 0.17). Most sexual risk behaviors declined similarly among participants in both arms (all P > 0.05). There were no serious adverse events related to study drug, although participants randomized to aripiprazole reported more akathisia, fatigue and drowsiness (P < 0.05). CONCLUSION:Compared with placebo, aripiprazole did not reduce methamphetamine use significantly among actively using, dependent adults.
    背景与目标: 目的:与安慰剂相比,测试阿立哌唑在减少依赖甲基苯丙胺的成年人中的使用效率。
    设计:参与者被随机分配接受12周的阿立哌唑或安慰剂治疗,为期3个月的随访和每周30分钟的药物滥用咨询平台。
    地点:该试验于2009年1月至2012年3月在旧金山公共卫生部进行。
    参与者:从社区场所招募了90名积极使用甲基苯丙胺的性活跃成年人。
    测量:主要结果是每周甲基苯丙胺阳性尿量的回归估计减少。次要结果是研究药物依从性[通过自我报告和药物事件监测系统(MEMS)],性风险行为和对甲基苯丙胺的戒断。
    结果:参与者的平均年龄为38.7岁,男性为87.8%,白人为50.0%,非裔美国人为18.9%,拉丁美洲人为16.7%。完成了后续访问和最后访问的83%。通过意向性治疗,与使用安慰剂的受试者相比,分配给阿立哌唑的受试者的甲基苯丙胺阳性尿液减少量相似[风险比(RR)0.88,95%的置信区间(CI):0.66-1.19,P = 0.41]。安慰剂组的尿液阳性率从73%(45名参与者中的33名)下降到45%(40名中的18名),阿立哌唑组从77%(44名中的34名)下降到44%(35名中的20名)。 MEMS和自报告的依从性分别为42%和74%,两臂之间没有显着差异(MEMS P = 0.31;自报告P = 0.17)。两组参与者中大多数性风险行为均以类似方式下降(所有P> 0.05)。尽管随机分组使用阿立哌唑的参与者报告有更多的静坐无力,疲劳和嗜睡,但没有与研究药物相关的严重不良事件(P <0.05)。
    结论:与安慰剂相比,阿立哌唑在积极使用依赖的成年人中并未显着减少甲基苯丙胺的使用。
  • 【SepMI和EhoI限制性核酸内切酶对DNA切割的金属离子依赖性。】 复制标题 收藏 收藏
    DOI:10.1016/j.micres.2012.08.003 复制DOI
    作者列表:Belkebir A,Azeddoug H
    BACKGROUND & AIMS: :Most of type II restriction endonucleases show an absolute requirement for divalent metal ions as cofactors for DNA cleavage. While Mg(2+) is the natural cofactor other metal ions can substitute it and mediate the catalysis, however Ca(2+) (alone) only supports DNA binding. To investigate the role of Mg(2+) in DNA cleavage by restriction endonucleases, we have studied the Mg(2+) and Mn(2+) concentration dependence of DNA cleavage by SepMI and EhoI. Digestion reactions were carried out at different Mg(2+) and Mn(2+) concentrations at constant ionic strength. These enzymes showed different behavior regarding the ions requirement, SepMI reached near maximal level of activity between 10 and 20mM while no activity was detected in the presence of Mn(2+) and in the presence of Ca(2+) cleavage activity was significantly decreased. However, EhoI was more highly active in the presence of Mn(2+) than in the presence of Mg(2+) and can be activated by Ca(2+). Our results propose the two-metal ion mechanism for EhoI and the one-metal ion mechanism for SepMI restriction endonuclease. The analysis of the kinetic parameters under steady state conditions showed that SepMI had a K(m) value for pTrcHisB DNA of 6.15 nM and a V(max) of 1.79×10(-2)nM min(-1), while EhoI had a K(m) for pUC19 plasmid of 8.66 nM and a V(max) of 2×10(-2)nM min(-1).
    背景与目标: :大多数II型限制性核酸内切酶显示了对二价金属离子作为DNA切割辅助因子的绝对要求。 Mg(2)是天然的辅助因子,其他金属离子可以替代它并介导催化作用,但是Ca(2)(单独)仅支持DNA结合。要研究Mg(2)在限制性内切核酸酶切割DNA中的作用,我们研究了SepMI和EhoI对Mg(2)和Mn(2)浓度依赖性的DNA切割的依赖性。在恒定的离子强度下,以不同的Mg(2)和Mn(2)浓度进行消化反应。这些酶在离子需求方面表现出不同的行为,SepMI在10至20mM之间达到最大活性水平,而在Mn(2)存在下未检测到活性,而在Ca(2)存在下裂解活性显着降低。但是,EhoI在存在Mn(2)时比在存在Mg(2)时具有更高的活性,并且可以被Ca(2)激活。我们的研究结果提出了EhoI的两种金属离子机制和SepMI限制性核酸内切酶的一种金属离子机制。稳态条件下的动力学参数分析表明,SepMI的pTrcHisB DNA的K(m)值为6.15 nM,V(max)为1.79×10(-2)nM min(-1),而EhoI为pUC19质粒的K(m)为8.66 nM,V(max)为2×10(-2)nM min(-1)。
  • 【猕猴的纹状皮质活动的动力学:I.伽玛带神经元振荡的发生率和刺激依赖性。】 复制标题 收藏 收藏
    DOI:10.1093/cercor/10.11.1105 复制DOI
    作者列表:Friedman-Hill S,Maldonado PE,Gray CM
    BACKGROUND & AIMS: :Using single and multiunit recordings in the striate cortex of alert macaque monkeys, we find that gamma-band (20-70 Hz) oscillations in neuronal firing are a prominent feature of V1 neuronal activity. The properties of this rhythmic activity are very similar to those previously observed in the cat. Gamma-band activity is strongly dependent on visual stimulation, largely absent during spontaneous activity and, under the conditions of our experiment, not time-locked to the vertical refresh of the computer monitor (80 Hz) used to present the stimuli. In our sample, 61% of multiunit activity (MUA) and 46% of single-unit activity (SUA) was significantly oscillatory, with mean frequencies of 48+/-9 and 42+/-13 Hz, respectively. Gamma-band activity was most likely to occur when cells were activated by their optimal stimuli, but still occurred, although less often and with lower amplitude, in response to nonoptimal stimuli. The frequency of gamma-band activity also reflected stimulus properties, with drifting gratings evoking higher-frequency oscillations than stationary gratings. As in the cat, the spike trains of single cells showing gamma-band oscillations often displayed a pattern of repetitive burst firing, with intraburst firing rates of 300-800 Hz. The overall similarity of rhythmic neuronal activity in the primary visual cortex of cats and monkeys suggests that the phenomenon is not species-specific. The stimulus-dependence of the rhythmic activity is consistent with a functional role in visual perception.
    背景与目标: :在警觉猕猴的纹状皮层中使用单单位和多单位记录,我们发现神经元放电中的伽马波段(20-70 Hz)振荡是V1神经元活动的突出特征。有节奏的活动的性质与以前在猫中观察到的性质非常相似。伽玛带活动强烈依赖于视觉刺激,在自发活动过程中基本上不存在,在我们的实验条件下,γ波段活动没有时间锁定到用于呈现刺激的计算机监视器的垂直刷新(80 Hz)上。在我们的样本中,61%的多单位活性(MUA)和46%的单单位活性(SUA)具有明显的振荡性,平均频率分别为48 / -9和42 / -13 Hz。当细胞被其最佳刺激激活时,伽马带活动最有可能发生,但仍会发生,尽管频率较低且幅度较小,但响应非最佳刺激仍会发生。 γ波段活动的频率也反映出刺激特性,与固定光栅相比,漂移光栅引起更高的频率振荡。像猫一样,显示伽马波段振荡的单个细胞的尖峰序列通常显示出重复的爆发式发射模式,爆发内发射频率为300-800 Hz。在猫和猴的初级视觉皮层中,节律性神经元活动的总体相似性表明,这种现象不是特定于物种的。节律活动的刺激依赖性与视觉感知中的功能作用一致。
  • 【使用分形维数对灰度阈值的依赖性来评估轴向骨骼中的骨质疏松程度。】 复制标题 收藏 收藏
    DOI:10.1259/bjr.70.834.9227251 复制DOI
    作者列表:Haidekker MA,Andresen R,Evertsz CJ,Banzer D,Peitgen HO
    BACKGROUND & AIMS: :Combining the measurement of bone mineral density (BMD) and the classification of the trabecular structure in cancellous bone improves the estimation of the degree of osteoporosis. A fractal method for the automatic quantitative classification of the trabecular structure in midvertebral slices of lumbar vertebrae is introduced. This method is based on the computation of the fractal dimension (box counting method) for varying binarization thresholds. Radiographic images from 30 lumbar vertebrae and CT images from an additional 16 lumbar vertebrae were analysed by calculating the dimension D in dependency of the threshold value T. The function D(T) was normalized by the average image grey value, eliminating the bone mineral density from the computations. The results show that the images of the lumbar vertebrae have fractal properties, and the function D(T) has a typical behaviour that allows the discrimination of the degree of osteoporosis. With two parameters extracted from the function D(T) the correlation coefficients with BMD were both -79% for the radiographic images, and -93% and -91% for the CT data, respectively.
    背景与目标: :结合骨矿物质密度(BMD)的测量和松质骨中小梁结构的分类,可以改善对骨质疏松程度的估计。介绍了一种用于腰椎中段椎骨小梁结构自动定量分类的分形方法。此方法基于变化的二值化阈值的分形维数(盒计数法)的计算。通过根据阈值T计算尺寸D来分析30个腰椎的放射线图像和其他16个腰椎的CT图像。函数D(T)通过平均图像灰度值归一化,消除了骨矿物质密度从计算。结果表明,腰椎图像具有分形特性,并且函数D(T)具有典型的行为,可以区分骨质疏松程度。从函数D(T)中提取两个参数后,对于放射线图像,与BMD的相关系数分别为-79%和CT数据分别为-93%和-91%。
  • 【蓝斑核中TRPV1受体在吗啡依赖性细胞的发育和表达中的作用。】 复制标题 收藏 收藏
    DOI:10.22038/ijbms.2019.35055.8338 复制DOI
    作者列表:Fatemi I,Hadadianpour Z,Fatehi F,Shamsizadeh A,Hasanshahi J,Abbasifard M,Kaeidi A
    BACKGROUND & AIMS: Objectives:This study investigated the role of locus coeruleus (LC) nucleus TRPV1 receptors (TRPV1r) in the expression and development of morphine physical dependence by intra-LC administration of AMG9810 (selective TRPV1r antagonist) in male Wistar rats. Materials and Methods:For assessing the development of morphine dependence, AMG9810 (0.03 and 0.3 mM in 10% DMSO, 0.2 µl; intra-LC microinjection) was administered before each morphine administration for seven continues days (once daily; 6, 16, 26, 36, 46, 56, and 66 mg/kg; sc). Furthermore, for evaluating the expression of morphine dependence, a single dose of AMG9810 (0.03 and 0.3 mM in 10% DMSO, 0.2 µl; intra-LC microinjection) was administered to morphine-dependent rats on day 8 of the experiment. Results:Obtained data demonstrated that co-administration of TRPV1r antagonist with morphine reduced the development of morphine withdrawal syndrome somatic signs induced by naloxone. Moreover, single intra-LC administration of TRPV1r antagonist on the final day of the examination period significantly decreased the expression of some signs of morphine withdrawal in rats. Conclusion:The results showed that LC TRPV1r might be participating in the expression and development of morphine dependence.
    背景与目标: 目的:本研究通过LC内注射AMG9810(选择性TRPV1r拮抗剂)在雄性Wistar大鼠中研究了蓝斑核(TR)核TRPV1受体(TRPV1r)在吗啡物理依赖性表达和发育中的作用。
    材料和方法:为了评估吗啡依赖性的发展,在每次连续7天(每天一次;每天一次; 6、16、26)连续施用吗啡之前,先施用AMG9810(0.03和0.3 mM,在10%DMSO中,0.2 µl; LC内注射)。 ,36、46、56和66 mg / kg; sc)。此外,为了评估吗啡依赖性的表达,在实验的第8天,向吗啡依赖性大鼠单剂量给予AMG9810(0.03和0.3 mM,在10%DMSO中,0.2 µl; LC内注射)。
    结果:获得的数据表明,TRPV1r拮抗剂与吗啡并用可减少纳洛酮诱导的吗啡戒断综合征体征的发生。此外,在检查期的最后一天单次LC-内给予TRPV1r拮抗剂可显着降低大鼠吗啡戒断症状的表达。
    结论:结果表明,LC TRPV1r可能参与了吗啡依赖的表达和发展。
  • 【阿魏酸增强颈动脉粥样硬化的三维磁共振成像-可行性和时间依赖性研究。】 复制标题 收藏 收藏
    DOI:10.1038/s41598-020-58708-x 复制DOI
    作者列表:Usman A,Patterson AJ,Yuan J,Cluroe A,Patterson I,Graves MJ,Gillard JH,Sadat U
    BACKGROUND & AIMS: :Ferumoxytol is an ultrasmall super paramagnetic particles of iron oxide (USPIO) agent recently used for magnetic resonance (MR) vascular imaging. Other USPIOs have been previously used for assessing inflammation within atheroma. We aim to assess feasibility of ferumoxytol in imaging carotid atheroma (with histological assessment); and the optimum MR imaging time to detect maximum quantitative signal change post-ferumoxytol infusion. Ten patients with carotid artery disease underwent high-resolution MR imaging of their carotid arteries on a 1.5 T MR system. MR imaging was performed before and at 24, 48, 72 and 96 hrs post ferumoxytol infusion. Optimal ferumoxytol uptake time was evaluated by quantitative relaxometry maps indicating the difference in T2* (ΔT2*) and T2 (ΔT2) between baseline and post-Ferumoxytol MR imaging using 3D DANTE MEFGRE qT2*w and iMSDE black-blood qT2w sequences respectively. 20 patients in total (10 symptomatic and 10 with asymptomatic carotid artery disease) had ferumoxytol-enhanced MR imaging at the optimal imaging window. 69 carotid MR imaging studies were completed. Ferumoxytol uptake (determined by a decrease in ΔT2* and ΔT2) was identified in all carotid plaques (symptomatic and asymptomatic). Maximum quantitative decrease in ΔT2* (10.4 [3.5-16.2] ms, p < 0.001) and ΔT2 (13.4 [6.2-18.9] ms; p = 0.001) was found on carotid MR imaging at 48 hrs following the ferumoxytol infusion. Ferumoxytol uptake by carotid plaques was assessed by histopathological analysis of excised atheroma. Ferumoxytol-enhanced MR imaging using quantitative 3D MR pulse sequences allows assessment of inflammation within carotid atheroma in symptomatic and asymptomatic patients. The optimum MR imaging time for carotid atheroma is 48 hrs after its administration.
    背景与目标: :Ferumoxytol是一种超小型超顺磁性氧化铁(USPIO)剂,最近用于磁共振(MR)血管成像。其他USPIO以前已用于评估动脉粥样硬化内的炎症。我们旨在评估阿魏酸在颈动脉粥样硬化成像中的可行性(通过组织学评估);以及最佳的MR成像时间,以检测在输精铁输注后最大的定量信号变化。十名颈动脉疾病患者在1.5 T MR系统上对其颈动脉进行了高分辨率MR成像。 MR成像是在输注阿魏酸之前和之后24、48、72和96小时进行的。通过定量弛豫测定图评估最佳阿魏木醇的摄取时间,该图显示了分别使用3D DANTE MEFGRE qT2 * w和iMSDE黑血qT2w序列在基线和富罗莫斯托尔MR成像之间的T2 *(ΔT2*)和T2(ΔT2)的差异。共有20例患者(10例有症状的患者和10例无症状的颈动脉疾病的患者)在最佳成像窗口进行了铁氧嘧啶增强的MR成像。完成69例颈动脉MR成像研究。在所有颈动脉斑块(有症状和无症状)中均发现了阿魏酸的摄取(由ΔT2*和ΔT2的降低确定)。在注入阿魏美土醇后48小时的颈动脉MR成像中,发现ΔT2*(10.4 [3.5-16.2] ms,p <0.001)和ΔT2(13.4 [6.2-18.9] ms; p = 0.001)的最大定量下降。通过切除的动脉粥样硬化的组织病理学分析评估颈动脉斑块对阿魏酸的摄取。使用定量3D MR脉冲序列增强阿魏酸的MR成像可以评估有症状和无症状患者的颈动脉粥样硬化内的炎症。颈动脉粥样硬化的最佳MR成像时间为给药后48小时。
  • 【超声在灌注犬肾脏中诱导的二维温度分布与流量的关系。】 复制标题 收藏 收藏
    DOI:10.3109/02656739109005002 复制DOI
    作者列表:Prionas SD,Raftery KA,Edmonds PD,Constantinou CE
    BACKGROUND & AIMS: :The influence of perfusate flow rate on the two-dimensional (2-D) temperature distributions induced by hyperthermia in the canine kidney was evaluated. Localized hyperthermia was induced by ultrasound (frequency 2.040 MHz, transducer diameter 6.7 cm) in the ex-vivo perfused kidney. Temperatures were mapped using shielded copper/constantan thermocouple sensors. The 2-D temperature distribution of the kidney was obtained by pulling these sensors through a planar array of eight stainless-steel trocars inserted along its longitudinal axis. The perfusion system allowed for the control of internal/external organ temperature and type of perfusate, and it simulated vasodilation and vasoconstriction by changing the arterial volume flow rate. The temperature data obtained at flow rates ranging from 0 to 570 ml/min and power levels from 0 to 150 W showed that acoustic power densities in excess of 1.5 W/cm2 were required to maintain therapeutic temperatures in this system. Contour maps for characterizing the 2-D temperature distributions induced in this system were analysed with the introduction of a quantitative measure based on the area within a given isotherm. They show the effects of tissue heterogeneity, flow rate, and non-uniform power deposition. Time constants computed from the exponentially decaying temperatures measured following power off ranged from 5 to 555 s. These findings provide a basis for comparison with temperature measurements being acquired in the in-vivo kidney system. Information acquired from this system may facilitate the process of developing tissue-equivalent dynamic phantoms for ultrasound-induced hyperthermia. The ex-vivo model presented in this paper might be used to study the performance of alternative heating applicators, the effect of haematocrit, blood viscosity, and the use of vasoactive drugs.
    背景与目标: :评估了灌注液流速对犬肾脏中热疗引起的二维(2-D)温度分布的影响。超声(频率2.040 MHz,换能器直径6.7 cm)在离体灌注肾脏中引起局部热疗。使用屏蔽的铜/常数热电偶传感器绘制温度图。肾脏的二维温度分布是通过将这些传感器拉过沿其纵轴插入的八个不锈钢套管针的平面阵列而获得的。灌注系统可以控制内部/外部器官的温度和灌注液的类型,并且它通过改变动脉体积流量来模拟血管舒张和血管收缩。在0到570 ml / min的流速和0到150 W的功率水平下获得的温度数据表明,在该系统中维持治疗温度需要超过1.5 W / cm2的声功率密度。通过引入基于给定等温线内面积的定量测量,分析了表征该系统中感应的二维温度分布的轮廓图。它们显示了组织异质性,流速和功率沉积不均匀的影响。根据断电后测得的指数衰减温度计算的时间常数范围为5到555 s。这些发现为与体内肾脏系统中获得的温度测量值进行比较提供了基础。从该系统获取的信息可能有助于开发用于超声诱发的体温过高的组织等效动态体模的过程。本文介绍的体外模型可用于研究替代供热器的性能,止血药的作用,血液粘度和使用血管活性药物。
  • 【多糖裂解酶家族2的祖先成员显示内切活性和镁依赖性。】 复制标题 收藏 收藏
    DOI:10.1007/s12010-013-0483-9 复制DOI
    作者列表:Abbott DW,Thomas D,Pluvinage B,Boraston AB
    BACKGROUND & AIMS: :Polysaccharide lyases (PLs) are enzymes that cleave glycosidic linkages in hexuronate polysaccharides, such as homogalacturonan (HG), using a β-elimination mechanism. Traditionally, PL activities on HG have been associated with catalytic calcium cofactors, unusually high pH optima, and arginine Brønstead bases. Recently, however, PL families that harness transition metal cofactors, utilize lysine and histidine Brønstead bases, and display more neutral pH optima have been described. One such family is PL2, which has members found primarily in phytopathogenic (e.g., Dickeya spp. and Pectobacterium spp.) or enteropathogenic (e.g., Yersinia spp.) bacterial species. PL2 is divided into two major subfamilies that are correlated with either an endolytic or exolytic activity. This study has focused on the activity of a PL2 member, which is not classified within either subfamily and helps to illuminate the origin of enzyme activities within the family. In addition, the role of Mg(2+) as a preferential catalytic metal for an intracellular PL2 (PaePL2) is described. The implications for the relationship between catalytic metal selectivity and the cellular location of pectate lyase-mediated catalysis are discussed.
    背景与目标: :多糖裂解酶(PLs)是使用β-消除机制裂解己糖酸酯多糖(如高半乳糖醛酸聚糖(HG))中糖苷键的酶。传统上,PL对HG的活性与催化性钙辅因子,异常高的pH最适值和精氨酸Brønstead碱有关。然而,最近已经描述了利用过渡金属辅因子,利用赖氨酸和组氨酸布朗斯台德碱并显示出更中性的pH最佳值的PL系列。一个这样的家族是PL2,其成员主要存在于植物致病性(例如Dickeya spp。和Pectobacterium spp。)或肠致病性(例如Yersinia spp。)细菌物种中。 PL2分为两个主要的亚科,它们与内切或外切活性相关。这项研究的重点是PL2成员的活性,该成员在任何一个亚科中均未分类,有助于阐明该家族中酶活性的起源。另外,描述了Mg(2)作为细胞内PL2(PaePL2)的优先催化金属的作用。讨论了催化金属选择性与果胶酸裂合酶介导的催化作用在细胞中的位置之间的关系。
  • 【荷兰少数民族中过量饮酒,暴饮酒和酗酒的比较:HELIUS研究。】 复制标题 收藏 收藏
    DOI:10.1159/000504881 复制DOI
    作者列表:van Amsterdam JGC,Benschop A,van Binnendijk S,Snijder MB,Lok A,Schene AH,Derks EM,van den Brink W
    BACKGROUND & AIMS: BACKGROUND:The Dutch multi-ethnic Healthy Life in an Urban Setting study recently showed that alcohol consumption was lower in ethnic minority groups than those of Dutch origin, but that binge drinking in drinkers of Turkish and Moroccan origin was relatively high. The aim of the current study is to examine factors that may contribute to the differences in drinking patterns and how they relate to the relationship between drinking patterns and alcohol dependence (AD) across ethnic groups. METHODS:The rate of last year alcohol use, alcohol use patterns and AD was assessed in 4,635 Dutch, 4,317 Moroccan, 4,036 Turkish, 2,459 Ghanaian, 4,426 African Surinamese and 3,357 South-Asian Surinamese participants (both men and women) born in Amsterdam, the Netherlands. RESULTS:Compared to the Dutch, the prevalence of (regular) drinking is substantially lower in all ethnic minority groups and regular drinkers among most ethnic minority groups have a lower adjusted risk to develop binge drinking and AD than the Dutch. For the prevalence of regular drinking, the ethnic differences are bigger than for the prevalence of current drinking. However, regular drinkers of Moroccan origin have a risk similar to the Dutch to develop binge drinking and AD; a finding that could not be explained by group differences in age, sex, religiosity, perceived discrimination, depression or guilt feelings about drinking. DISCUSSION:The prevalence data show that current drinking is lower and that regular drinking is much lower in ethnic minorities and - with the exception of those of Moroccan origin - ethnic minority regular drinkers also have a significant lower risk to develop binge drinking or AD than regular drinkers of Dutch origin. This implies that the magnitude of problematic alcohol use is substantially smaller in ethnic minorities than in the ethnic Dutch population of Amsterdam. Unfortunately, no explanation was found for the special risk situation of regular drinkers of Moroccan origin.
    背景与目标: 背景:荷兰城市环境中的多种族健康生活研究​​显示,少数民族人群的酒精消费量低于荷兰人群,但土耳其和摩洛哥裔饮酒者的酗酒相对较高。当前研究的目的是研究可能导致饮酒方式差异的因素,以及它们如何与跨族裔的饮酒方式与酒精依赖(AD)之间的关系相关。
    方法:评估了在阿姆斯特丹出生的4,635荷兰人,4,317摩洛哥人,4,036土耳其人,2,459加纳人,4,426非洲苏里南人和3,357南亚苏里南人(男性和女性)的去年酒精使用率,酒精使用方式和AD的发生率,荷兰人。
    结果:与荷兰人相比,在所有少数族裔人群中,(正常)饮酒的患病率要低得多,并且大多数少数民族人群中的经常饮酒者与荷兰人相比,发生暴饮和AD的调整后风险较低。就经常饮酒的患病率而言,种族差异要大于目前饮酒的患病率。但是,经常饮用摩洛哥起源的饮酒者与荷兰人有类似的发展狂饮和AD的风险。这一发现无法通过年龄,性别,宗教信仰,感知的歧视,沮丧或内drinking的饮酒感的群体差异来解释。
    讨论:患病率数据显示,少数民族中目前的饮酒量较低,而经常饮酒的比例要低得多-除了摩洛哥血统的少数民族以外,少数民族经常饮酒的人患暴饮或AD的风险也比正常人低得多荷兰裔饮酒者。这意味着在少数民族中,有问题的酒精消费量要比在阿姆斯特丹的荷兰族裔人口要小得多。不幸的是,没有找到关于摩洛哥普通饮酒者特殊危险情况的解释。
  • 【吸食海洛因与大麻与注射海洛因:对治疗效果的意外影响。】 复制标题 收藏 收藏
    DOI:10.1186/s12954-019-0337-z 复制DOI
    作者列表:Morgan N,Daniels W,Subramaney U
    BACKGROUND & AIMS: BACKGROUND:In several countries, especially in Africa, the dominant method of heroin intake is smoking a joint of cannabis laced with heroin. There is no data exploring the impact of smoking heroin with cannabis on treatment outcomes. AIM:To compare treatment outcomes between people who inject heroin and people who smoke heroin with cannabis. METHODOLOGY:Three hundred heroin users were assessed on admission to inpatient rehabilitation and after treatment. We compared drug use, psychopathology, criminality, social functioning and general health between heroin injectors and heroin-cannabis smokers at treatment entry, and at 3 and 9 months after rehabilitation. RESULTS:The sample comprised 211 (70.3%) heroin-cannabis smokers and 89 (29.7%) heroin injectors. Eighty-four percent were followed up at 3 months and 75% at 9 months. At 9 months, heroin-cannabis smokers had a higher proportion of those who relapsed to heroin use compared with intravenous (IV) users (p = 0.036). The median number of heroin use episodes per day was lower for IV users than heroin-cannabis smokers at both follow-up points (p = 0.013 and 0.0019). A higher proportion of IV users was HIV positive (p = 0.002). There were no significant differences in psychopathology, general health, criminality and social functioning between IV users and heroin-cannabis smokers at all three time points. CONCLUSIONS:Heroin users who do not inject drugs but use other routes of administration may have increased risk for relapse to heroin use after inpatient rehabilitation and should therefore have equal access to harm reduction treatment services. Advocating a transition from injecting to smoking heroin in an African context may pose unique challenges.
    背景与目标: 背景:在一些国家,特别是在非洲,海洛因摄入的主要方法是吸烟与海洛因绑在一起的大麻。没有数据探讨使用大麻吸食海洛因对治疗效果的影响。
    目的:比较注射海洛因的人和吸食海洛因的人与大麻之间的治疗效果。
    方法:对入院康复后和治疗后的300名海洛因使用者进行了评估。我们比较了进入治疗时以及康复后3个月和9个月时海洛因注射者与海洛因大麻吸烟者之间的药物使用,心理病理学,犯罪,犯罪行为,社会功能和一般健康状况。
    结果:该样本包括211名(70.3%)海洛因大麻吸烟者和89名(29.7%)海洛因注射者。在3个月时随访了84%,在9个月时随访了75%。在9个月的时间里,与静脉注射(IV)的使用者相比,吸食海洛因和大麻的吸烟者复发海洛因的比例更高(p = 0.036)。在两个随访点上,静脉吸毒者每天使用海洛因的中位数均低于海洛因大麻吸烟者(p = 0.013和0.0019)。静脉吸毒者中艾滋病毒呈阳性的比例更高(p = 0.002)。在所有三个时间点,静脉吸毒者和海洛因大麻吸烟者之间的心理病理学,总体健康,犯罪和社交功能均无显着差异。
    结论:未注射毒品但使用其他给药途径的海洛因使用者在住院康复后可能会增加海洛因使用的复发风险,因此应平等获得减害治疗服务。在非洲背景下倡导从注射海洛因向吸烟海洛因的过渡可能会带来独特的挑战。
  • 【尼古丁口香糖剂量受尼古丁依赖性水平的影响。】 复制标题 收藏 收藏
    DOI:10.1080/14622200050011303 复制DOI
    作者列表:Garvey AJ,Kinnunen T,Nordstrom BL,Utman CH,Doherty K,Rosner B,Vokonas PS
    BACKGROUND & AIMS: :We used the Heaviness of Smoking Index, a subset of the Fagerstrom Test for Nicotine Dependence, to classify 608 cigarette smokers planning a cessation attempt as low or high in nicotine dependence. Subjects within each level of dependence were then randomly assigned to placebo, 2-mg, or 4-mg nicotine gum treatment. Subjects were also provided brief (5-10 min per visit) behavioral counseling during a 1-year period of follow-up. At 1 year post-cessation, quit rates were 11.2, 19.5, and 18.4% for low-dependence smokers receiving placebo, 2-mg, and 4-mg gum, respectively (plinear trend = 0.20). For high-dependence smokers, quit rates at 1 year were 6.1, 15.7, and 20.7% for the placebo, 2-mg, and 4-mg gum conditions, respectively (plinear trend = 0.002). The interaction of nicotine-gum dose and dependence group was not significant (p = 0.42), nor did the 2-mg and 4-mg doses differ significantly in effectiveness, though both 2-mg and 4-mg gum were significantly more effective than placebo gum. We also found a significant dose-related effect for nicotine gum to moderate post-cessation heart-rate decline. Other variables related to abstinence at 1 year post-cessation were a longer period of abstinence on a prior quit attempt, being married, higher education level, and having a non-smoking spouse or significant other. Results indicate that nicotine gum is a significant aid to smoking cessation, more than doubling the odds of successful cessation compared to the odds for placebo-gum users. The 4-mg dose provided a non-significant increase in cessation rates for high-dependence smokers. Smoking history and demographic variables also have a significant impact on the outcome of a quit-smoking attempt.
    背景与目标: :我们使用烟瘾重度指数(法格斯特罗姆烟碱依赖性测试的一个子集)对计划戒烟尝试的608名吸烟者分类为低烟碱依赖性或高烟碱依赖性。然后将每个依赖性水平内的受试者随机分配给安慰剂,2 mg或4 mg尼古丁胶治疗。在一年的随访期内,还向受试者提供了简短的行为咨询(每次访问5-10分钟)。戒烟后1年,接受安慰剂,2 mg和4 mg牙龈的低依赖性吸烟者的戒烟率分别为11.2%,19.5%和18.4%(线性趋势= 0.20)。对于高依赖性吸烟者,安慰剂,2 mg和4 mg牙龈疾病在1年时的戒烟率分别为6.1、15.7和20.7%(线性趋势= 0.002)。尼古丁-口香糖剂量与依赖性组之间的相互作用不显着(p = 0.42),尽管2-mg和4-mg口香糖的疗效显着高于2-mg和4-mg口香糖,但两者的疗效也无显着差异。安慰剂胶。我们还发现尼古丁胶对中度戒烟后心率下降具有显着的剂量相关作用。与戒酒后1年的禁欲有关的其他变量包括戒烟前的戒酒时间较长,已婚,受过高等教育,配偶不吸烟或其他重要。结果表明,尼古丁口香糖是戒烟的重要辅助手段,与安慰剂口香糖使用者的戒烟几率相比,成功戒烟的几率要高出一倍以上。 4毫克剂量对高依赖性吸烟者的戒烟率没有显着增加。吸烟史和人口统计学变量也对尝试戒烟的结果产生重大影响。
  • 【膜电位驱动的蛋白质导入线粒体。细胞色素b(2)的分选序列调节基质靶向序列易位的deltapsi依赖性。】 复制标题 收藏 收藏
    DOI:10.1091/mbc.11.11.3977 复制DOI
    作者列表:Geissler A,Krimmer T,Bömer U,Guiard B,Rassow J,Pfanner N
    BACKGROUND & AIMS: :The transport of preproteins into or across the mitochondrial inner membrane requires the membrane potential Deltapsi across this membrane. Two roles of Deltapsi in the import of cleavable preproteins have been described: an electrophoretic effect on the positively charged matrix-targeting sequences and the activation of the translocase subunit Tim23. We report the unexpected finding that deletion of a segment within the sorting sequence of cytochrome b(2), which is located behind the matrix-targeting sequence, strongly influenced the Deltapsi-dependence of import. The differential Deltapsi-dependence was independent of the submitochondrial destination of the preprotein and was not attributable to the requirement for mitochondrial Hsp70 or Tim23. With a series of preprotein constructs, the net charge of the sorting sequence was altered, but the Deltapsi-dependence of import was not affected. These results suggested that the sorting sequence contributed to the import driving mechanism in a manner distinct from the two known roles of Deltapsi. Indeed, a charge-neutral amino acid exchange in the hydrophobic segment of the sorting sequence generated a preprotein with an even better import, i.e. one with lower Deltapsi-dependence than the wild-type preprotein. The sorting sequence functioned early in the import pathway since it strongly influenced the efficiency of translocation of the matrix-targeting sequence across the inner membrane. These results suggest a model whereby an electrophoretic effect of Deltapsi on the matrix-targeting sequence is complemented by an import-stimulating activity of the sorting sequence.
    背景与目标: :前蛋白进入或穿过线粒体内膜的运输需要跨该膜的膜电位Δpsi。已经描述了Deltapsi在可裂解的前蛋白的导入中的两个作用:对带正电的基质靶向序列的电泳作用和对转位酶亚基Tim23的激活。我们报告出乎意料的发现,删除细胞色素b(2)的排序序列中位于矩阵目标序列后面的一个段,强烈影响了进口的Deltapsi依赖性。差异Deltapsi依赖性与前蛋白的线粒体目的地无关,并且不依赖于线粒体Hsp70或Tim23的需求。使用一系列前蛋白构建体,分选序列的净电荷发生了变化,但导入的Deltapsi依赖性不受影响。这些结果表明,分拣顺序以不同于Deltapsi的两个已知角色的方式对进口驱动机制做出了贡献。实际上,在分选序列的疏水区段中的电荷中性氨基酸交换产生了具有甚至更好的进口的前蛋白,即,其具有比野生型前蛋白更低的Δpsi依赖性。分选序列在导入途径的早期起作用,因为它强烈影响基质靶向序列跨内膜的转运效率。这些结果提出了一种模型,其中Deltapsi对基质靶向序列的电泳作用被分选序列的导入刺激活性所补充。

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