• 【低能电子诱导的早期物理和化学事件引起的DNA损伤的计算模型。】 复制标题 收藏 收藏
    DOI:10.1080/095530097143798 复制DOI
    作者列表:Nikjoo H,O'Neill P,Goodhead DT,Terrissol M
    BACKGROUND & AIMS: Modelling and calculations are presented as a first step towards mechanistic interpretation and prediction of radiation effects based on the spectrum of initial DNA damage produced by low energy electrons (100 eV-4.5 keV) that can be compared with experimental information. Relative yields of single and clustered strand breaks are presented in terms of complexity and source of damage, either by direct energy deposition or by reaction of OH radicals, and dependence on the activation probability of OH radicals and the amount of energy required to give a single strand break (ssb). Data show that the majority of interactions in DNA do not lead to damage in the form of strand breaks and when they do occur, they are most frequently simple ssb. However, for double-strand breaks (dsb), a high proportion (approximately 30%) are of more complex forms, even without considering additional complexity from base damage. The greater contribution is from direct interactions in the DNA but reactions of OH radicals add substantially to this, both in terms of the total number of breaks and in increasing the complexity within a cluster. It has been shown that the lengths of damaged segments of DNA from individual electron tracks tend to be short, indicating that consequent deletion length (simply by loss of a fragment between nearby dsb) would be short, very seldom exceeding a few tens of base pairs.

    背景与目标: 建模和计算是迈向机理解释和辐射效应预测的第一步,该过程基于低能电子(100 eV-4.5 keV)产生的初始DNA损伤的光谱,可以与实验信息进行比较。单链和簇状链断裂的相对产率通过复杂性和破坏源(通过直接能量沉积或OH自由基的反应)以及OH自由基的活化概率和产生单原子所需的能量的数量来表示。断链(ssb)。数据表明,DNA中的大多数相互作用都不会以链断裂的形式导致损伤,并且当它们发生时,它们通常是简单的单链断裂。但是,对于双链断裂(dsb),即使不考虑基础损伤带来的额外复杂性,也有较高比例(约30%)具有更复杂的形式。更大的贡献来自于DNA中的直接相互作用,但是OH自由基的反应在断裂总数和增加簇内复杂性方面都大大增加了这一点。已经显示,来自单个电子迹线的DNA的受损片段的长度趋于较短,表明随后的缺失长度(仅由于附近dsb之间的片段的丢失)将较短,很少很少超过几十个碱基对。 。

  • 【听力损失平坦的听众的语音掩蔽释放:掩蔽者波动率对识别分数和语音特征接收的影响。】 复制标题 收藏 收藏
    DOI:10.1080/14992020600753213 复制DOI
    作者列表:Lorenzi C,Husson M,Ardoint M,Debruille X
    BACKGROUND & AIMS: :Consonant identification was measured for a stationary and amplitude-modulated noise masker in four listeners with flat cochlear hearing loss, and four age-matched normal-hearing listeners. The masker modulation rate was systematically varied between 2 and 128 Hz. Masking release (MR), that is better identification performance in fluctuating, than in stationary noise, was highest in a masker fluctuating at 8-16 Hz in all normal-hearing listeners. In comparison, MR was only observed in two out of the four impaired listeners. In these listeners, MR was poorer than normal, and peaked at lower rates, that is 2 or 8 Hz. MR corresponded to increased reception of information for voicing, place, and manner between 2 and 64 Hz in all normal-hearing listeners. In impaired listeners, increased reception of information was mainly observed for manner, and mainly reduced for place, but these differences were not significant. For all phonetic features, MR was observed at lower masker fluctuation rates (< or =32 Hz) than in normal-hearing listeners. This study therefore shows that cochlear damage affects MR, both quantitatively and qualitatively.
    背景与目标: :在四个平直的人工耳聋听力下降的听众和四个年龄相匹配的正常听力的听众中,对平稳和调幅的噪声掩蔽器的辅音识别进行了测量。掩蔽调制率在2到128 Hz之间系统地变化。在所有正常听力的听众中,以8-16 Hz波动的掩蔽器中,掩蔽释放(MR)的波动性要好于平稳噪声,这在静态噪声中具有更好的识别性能。相比之下,只有四个受损听者中有两个观察到了MR。在这些听众中,MR比正常人差,并且以较低的频率(即2或8 Hz)达到峰值。 MR对应于在所有正常听力的收听者中2至64 Hz之间的声音,位置和方式信息接收的增加。在听力受损的听众中,主要是通过方式观察到了信息接收的增加,而对于场所则主要是观察到的减少,但是这些差异并不明显。对于所有的语音特征,与正常听力的听众相比,在较低的掩蔽者波动率(<或= 32 Hz)下观察到了MR。因此,这项研究表明,耳蜗损害在数量和质量上都影响MR。
  • 【氯氮平在帕金森氏病中治疗左旋多巴引起的精神病的回顾性研究。】 复制标题 收藏 收藏
    DOI:10.1177/089198879701000205 复制DOI
    作者列表:Widman LP,Burke WJ,Pfeiffer RF,McArthur-Campbell D
    BACKGROUND & AIMS: Levodopa-induced psychosis can complicate the treatment of Parkinson's disease (PD). In this retrospective, uncontrolled report, we describe our experience treating PD-related psychosis with clozapine, emphasizing those patients treated for longer than 1 year. Twenty-seven patients were treated, 14 for longer than 1 year. Most patients showed a rapid improvement from baseline within 1 month using the Clinical Global Impression and Global Psychosis Rating Scores. Five patients discontinued the drug due to side effects, but only two patients reported side effects after 6 months of treatment. Clozapine appears to be effective in treating PD related psychotic symptoms while not interfering with motor function.

    背景与目标: 左旋多巴引起的精神病会使帕金森氏病(PD)的治疗复杂化。在这份回顾性的,不受控制的报告中,我们描述了用氯氮平治疗PD相关性精神病的经验,强调那些接受治疗超过1年的患者。治疗了27例患者,其中14例的病程超过1年。使用临床总体印象和总体精神病评分分数,大多数患者在1个月内显示出从基线开始的快速改善。五名患者由于副作用而停药,但只有两个患者在治疗6个月后报告了副作用。氯氮平似乎可以有效治疗PD相关的精神病症状,同时又不影响运动功能。

  • 【肿瘤诱导的前哨淋巴结免疫调节。】 复制标题 收藏 收藏
    DOI:10.1038/nri1919 复制DOI
    作者列表:Cochran AJ,Huang RR,Lee J,Itakura E,Leong SP,Essner R
    BACKGROUND & AIMS: :Sentinel lymph nodes (SLNs), being the first nodes to receive lymph from a primary tumour and the preferential site of initial tumour metastases, are intensively exposed to the bioactive products of tumour cells and other associated cells. This makes them ideal for studies of the factors that determine selective tissue susceptibility to metastases. We postulate that tumour-induced immune modulation of SLNs facilitates lymph-node metastases by inhibiting the generation of tumour-specific cytotoxic T cells that are active against tumour cells of primary and metastatic melanomas. Immune modulation of the lymph nodes can be reversed by granulocyte/macrophage colony-stimulating factor (GM-CSF), a finding that has implications for the future therapy of lymph-node metastases.
    背景与目标: 前哨淋巴结(SLNs)作为第一个从原发性肿瘤接受淋巴结和初始肿瘤转移的优先部位的淋巴结,被强烈暴露于肿瘤细胞和其他相关细胞的生物活性产物。这使它们成为研究决定选择性组织对转移的敏感性的因素的理想选择。我们推测,SLNs的肿瘤诱导免疫调节通过抑制对原发性和转移性黑素瘤的肿瘤细胞有活性的肿瘤特异性细胞毒性T细胞的产生,促进淋巴结转移。粒细胞/巨噬细胞集落刺激因子(GM-CSF)可逆转淋巴结的免疫调节作用,这一发现对未来淋巴结转移的治疗具有重要意义。
  • 【碳酸磷灰石引起的关节炎:多关节炎病例的考虑因素。】 复制标题 收藏 收藏
    DOI:10.1038/ncprheum0174 复制DOI
    作者列表:Blair-Levy JM
    BACKGROUND & AIMS: BACKGROUND:A 79-year-old woman was referred for evaluation of her painful and swollen joints. She had a medical history of congestive heart failure, renal insufficiency and peptic ulcer disease. For the past 3 years she had experienced recurrent bouts of debilitating arthritis, lasting approximately 3-4 weeks at a time. The symptoms were most severe in the hands and knees, where the joints were warm, swollen and tender. During each flare-up, the patient was housebound and required therapeutic dosing of nonsteroidal anti-inflammatory drugs and codeine to control joint pain. INVESTIGATIONS:Physical examination, fine-detailed radiographs of the hands, standing radiographs of the knees, arthrocentesis including cell count and gram stain, compensated polarized light microscopy, alizarin-red staining, X-ray diffraction, scanning and transmission electron microscopy with energy dispersive spectrometry, electron microprobe analysis with energy dispersive spectrometry, Fourier transform infrared spectroscopy, and atomic force microscopy. DIAGNOSIS:Carbonated-substituted apatite arthropathy. MANAGEMENT:Both knees were aspirated and large volumes of a straw-colored synovial fluid was removed. The knees were injected with corticosteroid, resulting in excellent symptomatic response.
    背景与目标: 背景:一名79岁的妇女被要求评估她的关节疼痛和肿胀。她有充血性心力衰竭,肾功能不全和消化性溃疡病的病史。在过去的三年中,她经历了反复发作的衰弱性关节炎发作,一次持续约3-4周。症状最严重的地方是手和膝盖,那里的关节温暖,肿胀和触痛。在每次发作期间,该患者待在屋内,需要非甾体抗炎药和可待因的治疗剂量以控制关节痛。
    调查:体格检查,手部细微X线照片,膝盖站立X线照片,关节穿刺术(包括细胞计数和革兰氏染色),补偿偏振光显微镜,茜素红染色,X射线衍射,扫描和透射电子显微镜(能量分散)光谱分析,带能量色散光谱的电子显微探针分析,傅立叶变换红外光谱和原子力显微镜。
    诊断:碳取代磷灰石关节炎。
    处理:吸除两个膝盖,并去除大量稻草色滑液。膝关节注射皮质类固醇激素,可产生出色的症状反应。
  • 【蛋白激酶D2通过NF-κB介导未转化的人结肠上皮细胞中溶血磷脂酸诱导的白介素8的产生。】 复制标题 收藏 收藏
    DOI:10.1152/ajpcell.00308.2006 复制DOI
    作者列表:Chiu TT,Leung WY,Moyer MP,Strieter RM,Rozengurt E
    BACKGROUND & AIMS: :The signaling pathways mediating lysophosphatidic acid (LPA)-stimulated PKD(2) activation and the potential contribution of PKD(2) in regulating LPA-induced interleukin 8 (IL-8) secretion in nontransformed, human colonic epithelial NCM460 cells were examined. Treatment of serum-deprived NCM460 cells with LPA led to a rapid and striking activation of PKD(2), as measured by in vitro kinase assay and phosphorylation at the activation loop (Ser706/710) and autophosphorylation site (Ser876). PKD(2) activation induced by LPA was abrogated by preincubation with selective PKC inhibitors GF-I and Ro-31-8220 in a dose-dependent manner. These inhibitors did not have any direct inhibitory effect on PKD(2) activity. LPA induced a striking increase in IL-8 production and stimulated NF-kappaB activation, as measured by NF-kappaB-DNA binding, NF-kappaB-driven luciferase reporter activity, and IkappaBalpha phosphorylation. PKD(2) gene silencing utilizing small interfering RNAs targeting distinct PKD(2) sequences dramatically reduced LPA-stimulated NF-kappaB promoter activity and IL-8 production. PKD(2) activation is a novel early event in the biological action of LPA and mediates LPA-stimulated IL-8 secretion in NCM460 cells through a NF-kappaB-dependent pathway. Our results demonstrate, for the first time, the involvement of a member of the PKD family in the production of IL-8, a potent proinflammatory chemokine, by epithelial cells.
    背景与目标: :审查了介导溶血磷脂酸(LPA)刺激的PKD(2)活化和PKD(2)在调节LPA诱导的非转化型人结肠上皮NCM460细胞中LPA诱导的白介素8(IL-8)分泌中的潜在作用。用体外LPA处理血清缺乏的NCM460细胞会导致PKD(2)迅速而惊人的激活,这是通过体外激酶测定和激活环(Ser706 / 710)和自磷酸化位点(Ser876)的磷酸化测量的。通过与选择性PKC抑制剂GF-1和Ro-31-8220呈剂量依赖性方式进行预孵育,可以消除LPA诱导的PKD(2)激活。这些抑制剂对PKD(2)活性没有任何直接的抑制作用。如通过NF-κB-DNA结合,NF-κB驱动的萤光素酶报道分子活性和IkappaBalpha磷酸化所测量,LPA诱导IL-8产量显着增加并刺激NF-κB活化。 PKD(2)基因沉默利用针对不同的PKD(2)序列的小干扰RNA,大大降低了LPA刺激的NF-κB启动子活性和IL-8的产生。 PKD(2)激活是LPA的生物学作用中的一个新的早期事件,并通过NF-κB依赖性途径介导LCM刺激NCM460细胞中IL-8的分泌。我们的结果首次证明,上皮细胞参与了PKD家族成员参与IL-8(一种有效的促炎趋化因子)的生产。
  • 【白细胞介素8在亨通巴尔通体诱导的血管生成中的自分泌作用。】 复制标题 收藏 收藏
    DOI:10.1128/IAI.00622-06 复制DOI
    作者列表:McCord AM,Resto-Ruiz SI,Anderson BE
    BACKGROUND & AIMS: :The gram-negative bacterium Bartonella henselae is capable of causing angiogenic lesions as a result of infection. Previously, it has been shown that B. henselae infection can result in production of the chemokine interleukin-8 (IL-8). In this study, we demonstrated that monocytes, endothelial cells, and hepatocytes produce IL-8 in response to B. henselae infection. We also investigated the role of IL-8 in B. henselae-induced endothelial cell proliferation and capillary tube formation. Both in vitro angiogenesis assays were IL-8 dependent. B. henselae-mediated inhibition of apoptosis, as indicated by gene expression of Bax and Bcl-2, was also shown to be IL-8 dependent in endothelial cells. Furthermore, infection of endothelial cells with B. henselae stimulated upregulation of the IL-8 chemokine receptor CXCR2. Infection of human endothelial cells by B. henselae resulting in IL-8 production likely plays a central role in the ability of this organism to cause angiogenesis during infection.
    背景与目标: 革兰氏阴性细菌汉氏巴尔通体(Bartonella henselae)能够由于感染而引起血管生成性病变。以前,已经证明,亨氏芽孢杆菌感染可以导致趋化因子白介素8(IL-8)的产生。在这项研究中,我们证明了单核细胞,内皮细胞和肝细胞对B. henselae感染产生IL-8。我们还研究了IL-8在B. henselae诱导的内皮细胞增殖和毛细管形成中的作用。两种体外血管生成测定都是IL-8依赖性的。如Bax和Bcl-2的基因表达所表明的,B。henselae介导的凋亡抑制在内皮细胞中也显示为IL-8依赖性。此外,用汉逊芽孢杆菌感染内皮细胞刺激了IL-8趋化因子受体CXCR2的上调。亨氏芽孢杆菌对人内皮细胞的感染导致IL-8的产生可能在该生物体在感染过程中引起血管生成的能力中起着核心作用。
  • 【儿茶酚胺诱导的痛觉感受器在交感神经中维持疼痛。】 复制标题 收藏 收藏
    影响因子 :
    发表时间:2007-02-01
    来源期刊:Pain
    DOI:10.1016/j.pain.2006.08.022 复制DOI
    作者列表:Jørum E,Ørstavik K,Schmidt R,Namer B,Carr RW,Kvarstein G,Hilliges M,Handwerker H,Torebjörk E,Schmelz M
    BACKGROUND & AIMS: :Sympathetically maintained pain could either be mediated by ephaptic interactions between sympathetic efferent and afferent nociceptive fibers or by catecholamine-induced activation of nociceptive nerve endings. We report here single fiber recordings from C nociceptors in a patient with sympathetically maintained pain, in whom sympathetic blockade had repeatedly eliminated the ongoing pain in both legs. We classified eight C-fibers as mechano-responsive and six as mechano-insensitive nociceptors according to their mechanical responsiveness and activity-dependent slowing of conduction velocity (latency increase of 0.5+/-1.1 vs. 7.1+/-2.0 ms for 20 pulses at 0.125 Hz). Two C-fibers were activated with a delay of several seconds following strong endogenous sympathetic bursts; they were also excited for about 3 min following the injection of norepinephrine (10 microl, 0.05%) into their innervation territory. In these two fibers, a prolonged activation by injection of low pH solution (phosphate buffer, pH 6.0, 10 microl) and sensitization of their heat response following prostaglandin E2 injection were recorded, evidencing their afferent nature. Moreover, their activity-dependent slowing was typical for mechano-insensitive nociceptors. We conclude that sensitized mechano-insensitive nociceptors can be activated by endogenously released catecholamines and thereby may contribute to sympathetically maintained pain. No evidence for ephaptic interaction between sympathetic efferent and nociceptive afferent fibers was found.
    背景与目标: :交感神经维持的疼痛可能由交感传入和传入的伤害性纤维之间的神经元相互作用或儿茶酚胺诱导的伤害性神经末梢的激活介导。我们在这里报告了在交感神经痛患者中,C伤害感受器的单纤维记录,在该患者中,交感神经阻滞反复消除了双腿持续的疼痛。根据它们的机械响应性和依赖于传导速度的活动性减慢,我们将8根C纤维分类为机械响应伤害感受器,将6根C纤维分类为对机械响应不敏感的伤害感受器(20个脉冲在0.125时延迟为0.5 /-1.1 vs. 7.1 /-2.0 ms赫兹)。在强烈的内源性交感神经爆发后,几秒钟的延迟激活了两根C纤维。在将去甲肾上腺素(10微升,0.05%)注入其神经支配区域后,他们还兴奋了约3分钟。在这两种纤维中,记录了通过注射低pH溶液(磷酸盐缓冲液,pH 6.0、10微升)的长时间激活以及注射前列腺素E2后对其热响应的敏化,证明了它们的传入性质。此外,它们对机械不敏感的伤害感受器的活动依赖性减慢作用是典型的。我们得出结论,致敏的对机械不敏感的伤害感受器可以被内源性释放的儿茶酚胺激活,从而可能有助于交感神经维持性疼痛。没有发现交感传入纤维和伤害性传入纤维之间的神经元相互作用的证据。
  • 【透皮硝化甘油连续或间歇治疗对清醒家兔起搏诱导的预处理的影响。】 复制标题 收藏 收藏
    DOI:10.1038/sj.bjp.0701163 复制DOI
    作者列表:Szilvassy Z,Ferdinandy P,Nagy I,Jakab I,Koltai M
    BACKGROUND & AIMS: :1. Tolerance to the hypotensive effect of nitroglycerin (NG) blocks preconditioning induced by rapid ventricular pacing (RVP) in rabbits. In the present work the effect of continuous versus intermittent treatment with transdermal nitroglycerin on the pacing-induced preconditioning phenomenon was studied in conscious rabbits. 2. RVP (500 beats min-1 over 5 min) increased left ventricular end-diastolic pressure (LVEDP) from baseline 4.1 +/- 0.9 to postpacing 13.8 +/- 2.9 mmHg (P < 0.001) with a right intraventricular ST-segment elevation of 1.25 +/- 0.13 mV, two indicators of myocardial ischaemia. These changes were significantly attenuated when the RVP period was preceded by a preconditioning pacing of the same rate and duration with an interpacing interval of 5 min. 3. Protection by preconditioning was abolished when the animals had been made tolerant to the vasodilator effect of 30 micrograms kg-1 NG by the application of transdermal NG (approx. 0.07 mg kg-1 h-1) over 7 days. Furthermore, transdermal NG per se attenuated both RVP-induced ST-segment elevation and LVEDP-increase over the 7 day period. 4. With intermittent transdermal NG treatment (12 h 'patch on' vs 'patch off'), neither development of vascular tolerance nor attenuation of the NG- or preconditioning-induced anti-ischaemic effects were observed. However, the severity of pacing-induced myocardial ischaemia was significantly increased during the 'patch off' periods. 5. In a second set of experiments, postpacing changes in cardiac cyclic GMP and cyclic AMP levels were determined by means of radioimmunoassay in chronically instrumented anaesthetized open-chest rabbits with the same NG-treatment protocols. Preconditioning reduced postpacing increase in cyclic AMP with an increase in cyclic GMP concentrations in hearts of the untreated animals and in those given patches intermittently during both 'patch on' and 'patch off' periods. However, the preconditioning effect on either cyclic nucleotide was blocked in the tolerant animals. 6. Transdermal NG increased resting levels of both cardiac cyclic nucleotides in the non-tolerant but not in the tolerant state. The postpacing increase in cyclic AMP content was inhibited by transdermal NG, independent of vascular tolerance development, whereas an cyclic GMP content was exclusively seen in the non-tolerant animals. 7. We conclude that the anti-ischaemic effect of NG is independent of the cyclic GMP mechanism in the tolerant state. While intermittent NG therapy prevents development of vascular tolerance and preserves preconditioning, the nitrate-free periods yield an increased susceptibility of the heart to ischaemic challenges.
    背景与目标: :1。耐硝酸甘油(NG)的降压作用可阻止兔快速心室起搏(RVP)诱导的预处理。在目前的工作中,在有意识的兔子中研究了经皮硝酸甘油连续或间歇治疗对起搏诱发的预适应现象的影响。 2. RVP(5分钟内min-1搏动)在左室舒张末期压力(LVEDP)从基线4.1 /-0.9增加到后起搏13.8 /-2.9 mmHg(P <0.001),并且右室ST段抬高1.25 /-0.13 mV,是心肌缺血的两个指标。当在RVP周期之前以5分钟的间隔间隔进行相同速度和持续时间的预适应性起搏后,这些变化会大大减弱。 3.当通过在7天内施用透皮NG(约0.07 mg kg-1 h-1)使动物耐受30微克kg-1 NG的血管舒张作用时,取消了通过预处理的保护。此外,在7天内,透皮NG本身减弱了RVP诱导的ST段升高和LVEDP升高。 4.间歇性透皮NG治疗(12小时“贴片”与“贴片”),既未观察到血管耐受性的发展,也未观察到NG或预处理引起的抗局部缺血作用的减弱。但是,起搏期间,起搏诱发的心肌缺血的严重程度显着增加。 5.在第二组实验中,通过放射免疫测定法在具有相同NG处理方案的经慢性麻醉的开胸兔中测定了心脏循环GMP和循环AMP水平的起搏变化。预处理减少了循环AMP的起搏后增加,同时在“贴片”和“贴片”期间间歇性地给未治疗的动物的心脏和那些给定贴片的动物增加了循环GMP的浓度。然而,在耐受性动物中,对任一环状核苷酸的预处理作用均被阻断。 6.经皮NG增加了非耐受性但非耐受性状态下两个心脏环状核苷酸的静息水平。循环AMP含量的起搏后增加受透皮NG抑制,与血管耐受性的发展无关,而环状GMP含量仅在非耐受性动物中观察到。 7.我们得出结论,在耐受状态下,NG的抗缺血作用与循环GMP机制无关。间歇性NG治疗可防止血管耐受性发展并保留预处理,而无硝酸盐治疗期则增加了心脏对缺血性疾病的敏感性。
  • 【P物质氨基末端代谢产物在P物质引起的小鼠脱敏中的作用。】 复制标题 收藏 收藏
    DOI:10.1016/0306-4522(90)90003-3 复制DOI
    作者列表:Igwe OJ,Sun X,Larson AA
    BACKGROUND & AIMS: :Intrathecal injection of mice with substance P or its C-terminal fragments evokes a well documented behavioral syndrome characterized by caudally-directed biting and scratching. We have previously shown that repeated injections of substance P result in naloxone-sensitive desensitization to this substance P-induced behavior, possibly through interactions of N-terminal fragments of substance P with mu opiate binding sites. The present investigation tests the hypothesis that substance P metabolites play a role in the development of desensitization to substance P by using the biting and scratching behavioral paradigm. While substance P-induced behaviors are produced by as little as 1 pmol of substance P, repeated injections of 7.5 pmol at 60-s intervals was found to be the minimum dose capable of causing desensitization. The C-terminal peptides, substance P3-11 and substance P5-11, elicited substance P-like behaviors, but repeated injection of these compounds did not result in desensitization to this behavior. In contrast to C-terminal fragments, intrathecal injection of N-terminal fragments, (substance P1-4, substance P1-7 and substance P1-9), did not elicit any overt substance P-like behaviors when administered alone, but when co-administered with substance P, decreased the magnitude of substance P-induced behaviors in a dose-related fashion. Various peptidase inhibitors significantly inhibited the catabolism of co-administered substance P. Co-administration of substance P with peptidase inhibitors enhanced and prolonged the substance P-induced behavioral episode, but also prevented the development of substance P-induced desensitization. Together these results support the hypothesis that the accumulation of endogenously generated N-terminal metabolites of substance P mediate desensitization to substance P-induced behaviors in the spinal cord. Substance P metabolism may therefore decrease ongoing substance P activity both by the hydrolysis of the C-terminal portion of substance P as well as by the production of N-terminal metabolites that are capable of inhibiting the effects of substance P.
    背景与目标: 鞘内注射P物质或其C端片段会引起行为异常综合征,其特征是尾巴定向咬伤和抓挠。先前我们已经表明,重复注射P物质可能导致纳洛酮对这种P物质诱导的行为敏感,这可能是由于P物质的N末端片段与阿片结合位点的相互作用所致。本研究检验了以下假设,即物质P代谢产物通过使用咬和抓挠行为范式在对物质P脱敏的发展中起作用。虽然物质P诱导的行为仅由1 pmol的物质P产生,但发现以60秒的间隔重复注射7.5 pmol是能够引起脱敏的最小剂量。 C末端肽(物质P3-11和物质P5-11)引起了物质P样的行为,但是重复注射这些化合物不会导致对该行为的脱敏。与C末端片段相反,鞘内注射N末端片段(物质P1-4,物质P1-7和物质P1-9)在单独给药时不会引起任何明显的P样行为,但在联合给药时与物质P一起给药,以剂量相关的方式降低了物质P诱导的行为的幅度。各种肽酶抑制剂可显着抑制物质P共同给药的分解代谢。物质P与肽酶抑制剂的共同给药增强并延长了物质P引起的行为发作,但也阻止了物质P引起的脱敏。这些结果共同支持以下假设:内源性生成的P物质的N末端代谢产物的积累介导了对P物质诱导的脊髓行为的脱敏。因此,P物质的代谢可能会通过P物质的C末端部分水解以及产生能够抑制P物质作用的N末端代谢产物而降低正在进行的P物质活动。
  • 【在正常和脱水大鼠中,μ阿片受体是否参与了内皮素-1从垂体的释放控制?】 复制标题 收藏 收藏
    DOI:10.1016/s0167-0115(97)02134-4 复制DOI
    作者列表:Płonowski A,Szymańska-Debińska T,Radzikowska M,Baranowska B,Woźniewicz B
    BACKGROUND & AIMS: UNLABELLED:The objective of the present study was to investigate whether the endogenous opioids are involved in the control of endothelin-1 release from the pituitary gland. To test this hypothesis we have measured the peripheral plasma concentration of ET-1 as well as the content of immunoreactive ET-1 (irET-1) in the pituitary in response to opioid receptors blockade in euhydrated and 24 h water-deprived Wistar-Kyoto rats. Placebo or naltrexone (50 micrograms/kg body wt.) were given i.v. in both groups. Trunk blood was collected to determine hematocrit, plasma sodium and ET-1 levels (RIA). Immunostaining of ET-1 in the whole pituitary glands was performed by colloidal gold labeling. The quantitative analysis of irET-1 was carried out under a light microscope using a computerized image analyzer (MultiScan). RESULTS:(1) Twenty-four-hour dehydration resulted in marked increase of peripheral concentration of ET-1. Naltrexone injection induced a significant elevation of ET-1 plasma concentration in both, dehydrated and control animals. (2) The content of irET-1 in anterior and intermediate lobes of the pituitary in dehydrated rats was markedly higher than in control group. (3) Naltrexone injection caused a rapid and significant reduction irET-1 within the anterior, intermediate and posterior lobes in dehydrated and control animals. CONCLUSIONS:(1) An elevation of irET-1 in the pituitary gland and peripheral circulation in dehydrated animals may play a role in maintaining of water-electrolyte balance. (2) The mu-opioid system appears to control the ET-1 release from the pituitary in normal and dehydrated animals.
    背景与目标: 未标记:本研究的目的是调查内源性阿片类药物是否参与垂体中内皮素-1的释放。为了检验这一假设,我们测量了在无水和缺水24小时的Wistar-Kyoto中阿片受体阻滞后垂体中ET-1的外周血浆浓度以及免疫反应性ET-1(irET-1)的含量大鼠。静脉注射安慰剂或纳曲酮(50微克/千克体重)。在两组中。收集躯干血液以确定血细胞比容,血浆钠和ET-1水平(RIA)。 ET-1在整个垂体中的免疫染色是通过胶体金标记进行的。使用计算机图像分析仪(MultiScan)在光学显微镜下对irET-1进行定量分析。
    结果:(1)脱水24小时导致ET-1的外周血浓度明显升高。纳曲酮注射液在脱水和对照动物中均引起ET-1血浆浓度的显着升高。 (2)脱水大鼠垂体前叶和中间叶中irET-1的含量明显高于对照组。 (3)纳曲酮注射液导致脱水和对照动物的前叶,中叶和后叶内irET-1迅速大量降低。
    结论:(1)脱水动物垂体中irET-1的升高和外周循环可能在维持水电解质平衡中起着重要作用。 (2)在正常和脱水动物中,μ阿片样物质系统似乎可以控制ET-1从垂体的释放。
  • 【抗坏血酸对维生素E缺乏大鼠离体肾上腺细胞中ACTH诱导的环AMP形成和类固醇生成的影响。】 复制标题 收藏 收藏
    DOI:10.1016/0304-4165(75)90255-x 复制DOI
    作者列表:Nathans AH,Kitabchi AE
    BACKGROUND & AIMS: :Isolated adrenal cells from Vitamin E-deficient and control rats were prepared by a trypsin digestion method. Cyclic adenosine 3',5'-monophosphate (cyclic AMP) formation was studied in response to adrenocorticotropin (ACTH) in the presence and absence of ascorbate by measuring the conversion of prelabeled adenosine 5'-triphosphate [14C]ATP to cyclic [14C]AMP. Ascorbate (0.5 mM) inhibited ACTH-induced cyclic [14C]AMP formation in adrenal cells isolated from Vitamin E-deficient rats but had no effect in the control cells. The inhibitory effect of ascorbate on ACTH-induced cyclic AMP formation in Vitamin E-deficient rats decreased as the concentration of ACTH increased. In Vitamin E-deficient rats ascorbate inhibited ACTH-induced cyclic [14C]AMP formation after 30 min of incubation. There was no further significant accumulation of cyclic [14C]AMP at 60 min or 120 min although in the absence of ascorbate cyclic [14C]AMP continued to be formed. The in vitro addition of alpha-tocopherol reduced the inhibition of ACTH-induced cyclic [14C]AMP formation by ascorbate in Vitamin E-deficient rats. These studies suggest that alpha-tocopherol and ascorbate may affect ACTH-induced cyclic AMP formation through interaction with the membrane-bound enzyme adenylate cyclase.
    背景与目标: :通过胰蛋白酶消化方法,从维生素E缺乏和对照大鼠中分离出肾上腺细胞。通过测量预先标记的5'-三磷酸腺苷[14C] ATP向环状[14C]的转化,研究了在存在和不存在抗坏血酸的情况下响应于促肾上腺皮质激素(ACTH)形成环状3',5'-单磷酸腺苷(环状AMP)的现象。 AMP。抗坏血酸(0.5 mM)抑制ACTH诱导的从维生素E缺乏症大鼠分离的肾上腺细胞中环[14C] AMP的形成,但对对照细胞没有作用。随着ACTH浓度的增加,抗坏血酸对ACTH诱导的维生素E缺乏症大鼠环AMP形成的抑制作用降低。在维生素E缺乏的大鼠中,孵育30分钟后,抗坏血酸会抑制ACTH诱导的环状[14C] AMP的形成。尽管在不存在抗坏血酸盐的情况下仍继续形成环状[14C] AMP,但在60分钟或120分钟时没有进一步显着的环状[14C] AMP蓄积。在维生素E缺乏的大鼠中,体外添加α-生育酚可降低抗坏血酸对ACTH诱导的环[14C] AMP形成的抑制作用。这些研究表明,α-生育酚和抗坏血酸可能通过与膜结合酶腺苷酸环化酶相互作用而影响ACTH诱导的环AMP的形成。
  • 【阴离子通道阻滞剂4,4'-dinitrostilbene-2,2'-二磺酸可在体内抑制海马体内糖酵解过程中防止神经元死亡和兴奋性氨基酸释放。】 复制标题 收藏 收藏
    DOI:10.1016/j.neuroscience.2006.07.004 复制DOI
    作者列表:Camacho A,Montiel T,Massieu L
    BACKGROUND & AIMS: :Neuronal death associated with cerebral ischemia and hypoglycemia is related to increased release of excitatory amino acids (EAA) and energy failure. The intrahippocampal administration of the glycolysis inhibitor, iodoacetate (IOA), induces the accumulation of EAA and neuronal death. We have investigated by microdialysis the role of exocytosis, glutamate transporters and volume-sensitive organic anion channel (VSOAC) on IOA-induced EAA release. Results show that the early component of EAA release is inhibited by riluzole, a voltage-dependent sodium channel blocker, and by the VSOAC blocker, tamoxifen, while the early and late components are blocked by the glutamate transport inhibitors, L-trans-pyrrolidine 2,4-dicarboxylate (PDC) and DL-threo-beta-benzyloxyaspartate (DL-TBOA); and by the VSOAC blocker 4,4'-dinitrostilbene-2,2'-disulfonic acid (DNDS). Riluzole, DL-TBOA and tamoxifen did not prevent IOA-induced neuronal death, while PDC and DNDS did. The VSOAC blockers 5-nitro-2-(3-phenylpropyl-amino) benzoic acid (NPPB) and phloretin had no effect either on EAA efflux or neuronal damage. Results suggest that acute inhibition of glycolytic metabolism promotes the accumulation of EAA by exocytosis, impairment or reverse action of glutamate transporters and activation of a DNDS-sensitive mechanism. The latest is substantially involved in the triggering of neuronal death. To our knowledge, this is the first study to show protection of neuronal death by DNDS in an in vivo model of neuronal damage, associated with deficient energy metabolism and EAA release, two conditions involved in some pathological states such as ischemia and hypoglycemia.
    背景与目标: :与脑缺血和低血糖有关的神经元死亡与兴奋性氨基酸(EAA)释放增加和能量衰竭有关。海马内糖酵解抑制剂碘乙酸盐(IOA)的给药可诱导EAA积累和神经元死亡。我们已经通过微透析研究了胞吐作用,谷氨酸转运蛋白和体积敏感性有机阴离子通道(VSOAC)对IOA诱导的EAA释放的作用。结果表明,EAA释放的早期组分被电压依赖性钠通道阻滞剂利鲁唑和VSOAC阻断剂他莫昔芬抑制,而谷氨酸转运抑制剂L-反式吡咯烷2则阻断了早期和晚期组分。 ,4-二羧酸盐(PDC)和DL-苏-β-苄氧基天冬氨酸(DL-TBOA);通过VSOAC阻滞剂4,4'-二硝基二苯乙烯-2,2'-二磺酸(DNDS)。利鲁唑,DL-TBOA和他莫昔芬不能预防IOA诱导的神经元死亡,而PDC和DNDS可以预防。 VSOAC阻滞剂5-硝基-2-(3-苯基丙基-氨基)苯甲酸(NPPB)和荧光素对EAA流出或神经元损伤均无影响。结果表明,糖酵解代谢的急性抑制可通过胞吐作用,谷氨酸转运蛋白的损伤或逆向作用以及DNDS敏感机制的激活来促进EAA的积累。最新消息实质上涉及神经元死亡的触发。据我们所知,这是第一个在体内神经元损伤模型中由DNDS保护神经元死亡的研究,该模型与能量代谢不足和EAA释放有关,这是某些病理状态(例如局部缺血和低血糖)的两个条件。
  • 【血红素加氧酶诱导与实验诱导的角膜炎症减弱。】 复制标题 收藏 收藏
    DOI:10.1016/s0006-2952(97)00080-4 复制DOI
    作者列表:Laniado-Schwartzman M,Abraham NG,Conners M,Dunn MW,Levere RD,Kappas A
    BACKGROUND & AIMS: Heme oxygenase (HO), by catabolizing heme to bile pigments, down-regulates cellular levels of heme and hemeproteins; certain of the latter, i.e. cytochrome P450s, generate pro-inflammatory products from endogenous substrates. Two HO isozymes, the products of distinct genes, have been described; HO-1 is the inducible one, whereas HO-2 is believed to be constitutively expressed. We studied the inducing effects of several metal compounds [CoCl2, SnCl2, ZnCl2, heme, and cobalt protoporphyrin (CoPP)] on HO-1 mRNA content and enzyme activity in cultures of rabbit corneal epithelial (RCE) cells; these metal compounds are known to induce HO in other tissues. Additionally, we studied HO-1 expression in an experimental model of ocular inflammation produced in rabbit corneas by extended contact lens wear, and the relation of HO expression to the induced inflammatory process. SnCl2 added to RCE cells in vitro produced marked time- and concentration-dependent increases in HO-1 mRNA and HO-1 enzyme activity; CoCl2, ZnCl2, and CoPP were inducers of HO as well, though to a lesser degree than SnCl2. Corneas treated for 6 days with contact lenses impregnated with SnCl2 displayed substantially less corneal inflammation, swelling, and new vessel invasion than did controls; attenuation of ocular inflammation was paralleled by SnCl2-induced increases in HO mRNA and HO activity in corneal epithelial cells from treated eyes. It is suggested that amelioration of the inflammatory response produced by extended contact lens wear is due, in part, to the induction of high levels of HO-1 activity by SnCl2, which results in diminished production of pro-inflammatory mediators generated through heme-dependent metabolic processes. Regulation of HO activity in this manner may have clinical applications.

    背景与目标: 血红素加氧酶(HO)通过将血红素分解为胆汁色素,从而下调血红素和血红蛋白的细胞水平。后者中的某些,即细胞色素P450,从内源性底物产生促炎性产物。已经描述了两种HO同功酶,它们是不同基因的产物。 HO-1是可诱导的,而HO-2被认为是组成型表达的。我们研究了几种金属化合物[CoCl2,SnCl2,ZnCl2,血红素和钴原卟啉(CoPP)]对兔角膜上皮(RCE)细胞培养物中HO-1 mRNA含量和酶活性的诱导作用。已知这些金属化合物会在其他组织中诱导HO。此外,我们研究了在长期角膜接触镜下兔子角膜产生的眼部炎症实验模型中HO-1的表达,以及HO表达与诱导的炎症过程的关系。体外添加到RCE细胞中的SnCl2在HO-1 mRNA和HO-1酶的活性上产生了明显的时间依赖性和浓度依赖性。 CoCl2,ZnCl2和CoPP也是HO的诱导剂,尽管程度要比SnCl2小。与对照组相比,用浸渍有SnCl2的隐形眼镜处理6天的角膜显示出的角膜发炎,肿胀和新血管侵袭明显少于对照组。眼炎症的减弱与SnCl2诱导处理过的眼睛的角膜上皮细胞中HO mRNA和HO活性增加有关。有人提出,长期佩戴隐形眼镜可减轻炎症反应,部分原因是SnCl2诱导了高水平的HO-1活性,这导致血红素依赖性促炎介质的产生减少。代谢过程。以这种方式调节HO活性可能具有临床应用。

  • 【血管紧张素II激活动脉平滑肌细胞中介导的Ca2激活的K通道。】 复制标题 收藏 收藏
    DOI:10.1016/j.yjmcc.2006.07.010 复制DOI
    作者列表:Hayabuchi Y,Nakaya Y,Yasui S,Mawatari K,Mori K,Suzuki M,Kagami S
    BACKGROUND & AIMS: :Angiostensin II (Ang II) regulates the migration and proliferation of vascular smooth muscle cells. Recent studies indicate that intermediate-conductance Ca2+ -activated K+ (IKca) channels have an important role in cell migration and proliferation. It is not known, however, whether the action of Ang II is linked to IKca channel regulation. Here, we investigated the modulation of IKca channels by Ang II in artery smooth muscle cells. Functional IKca channel expression in cultured embryonic rat aorta smooth muscle (A10) cells was studied using the patch-clamp technique. These cells predominantly express IKca channels. In contrast, large-conductance Ca2+ -activated K+ (BKca) currents were rarely observed in excised patches. Ang II increased the IKca current in a contration-dependent manner. Losartan (1.0 microM), an AT1 selective antagonist, abolished the activation of IKca channels by Ang II. Pretreatment with 100 microM myristoylated protein kinase C inhibitor peptide 20-28 or 10 microM GF109203X completely abolished the AngII-induced activation of IKca currents, whereas the action of Ang II was not prevented in the presence of 100 microM Rp-cyclic 3', 5'-hydrogen phosphotiate adenosine triethylammonium, a protein kinase A inhibitor, or 1.0 microM KT-5823, a protein kinase G inhibitor. A membrane permeant analogue of diacylglycerol 1, 2-dioctanoyl-sn-glycerol (10 microM) induced the activation of IKca currents. These data suggest that Ang II activates IKca channels through the activation of protein kinase C, and the AT1 receptor is involved in the regulation of these channels.
    背景与目标: :血管紧张素II(Ang II)调节血管平滑肌细胞的迁移和增殖。最近的研究表明,中导Ca2激活的K(IKca)通道在细胞迁移和增殖中具有重要作用。但是,尚不清楚Ang II的作用是否与IKca通道调节有关。在这里,我们研究了血管平滑肌细胞中Ang II对IKca通道的调节作用。使用膜片钳技术研究了在培养的大鼠大鼠主动脉平滑肌(A10)细胞中功能性IKca通道的表达。这些细胞主要表达IKca通道。相反,在切除的斑块中很少观察到大电导的Ca2激活的K(BKca)电流。 Ang II以依赖冲突的方式增加了IKca电流。 Losartan(1.0 microM),一种AT1选择性拮抗剂,取消了Ang II对IKca通道的激活。用100 microM肉豆蔻酰化的蛋白激酶C抑制剂肽20-28或10 microM GF109203X进行的预处理完全消除了AngII诱导的IKca电流激活,而在存在100 microM Rp-环3',5的情况下并未阻止Ang II的作用。 -磷酸磷酸氢腺苷三乙铵,一种蛋白激酶A抑制剂,或1.0 microM KT-5823,一种蛋白激酶G抑制剂。二酰基甘油1、2-二辛酰基-sn-甘油(10 microM)的膜渗透类似物诱导了IKca电流的激活。这些数据表明,Ang II通过蛋白激酶C的激活来激活IKca通道,而AT1受体参与了这些通道的调节。

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