回转模拟失重对心肌成纤维细胞Ⅰ型胶原代谢的影响

为探讨模拟失重对心肌成纤维细胞Ⅰ型胶原代谢的影响 ,本研究采用回转器模拟失重效应 ,通过免疫细胞化学和反转录聚合酶链式反应 (RT PCR)研究了回转模拟失重对原代培养的新生大鼠心肌成纤维细胞Ⅰ型胶原蛋白及mRNA表达 ,以及胶原降解抑制物———金属蛋白酶组织抑制因子 (Tissueinhibitorofmetallopro teinase ,TIMP)mRNA表达的影响。免疫细胞化学染色显示回转组Ⅰ型胶原蛋白沉积增加 ;RT PCR分析显示Ⅰ型胶原α1链 (TypeⅠcollagenα1chain ,ColⅠA1)mRNA表达没有明显变化 ,TIMP 1、TIMP 2及TIMP 3的mRNA表达均增强。提示在回转模拟失重条件下 ,心肌成纤维细胞Ⅰ型胶原蛋白沉积增加 ,作为胶原降解抑制物的TIMP可能是造成胶原沉积的原因     

SAHA对TGF-β诱导人胚肺成纤维细胞α-SMA蛋白及前胶原蛋白mRNA表达的影响

目的:探讨在转化生长因子-β 1(TGF-β1)刺激下,组蛋白去乙酰化酶抑制剂辛二酰苯胺异羟肟酸(SAHA)对人胚肺成纤维细胞系HELF向肌成纤维细胞(MF)分化时,α-SMA蛋白及前胶原蛋白mRNA表达的影响.方法:体外培养人胚肺成纤维细胞系HELF,并根据不同的实验目的分为空白对照组,TGF-β1处理组以及SAHA干预组.细胞处理结束后,用Western blot检测α-SMA表达,RT-PCR检测Ⅰ、Ⅲ型前胶原的mRNA表达水平.结果:空白对照组中几乎无α-SMA蛋白表达,TGF-β1处理后α-SMA水平显著增高,而SAHA能有效降低α-SMA的水平.SAHA孵育24h后,能够明显抑制TGF-βl刺激后的细胞表达Ⅰ型和Ⅲ型前胶原蛋白mRNA,并且具有明显的剂量依赖性.结论:SAHA能降低TGF-βl诱导HELF细胞向MF转化时α-SMA表达以及前胶原蛋白表达.     

铜蓝蛋白及纤维粘连蛋白对石英粉尘促进胶原转录的协同作用

本文使用人胶原α_1(Ⅰ)、α_2(Ⅰ)和α_1(Ⅲ)链cDNA探针,采用斑点杂交技术观察了铜蓝蛋白(ceruloplasmin,Cp)和纤维粘连蛋白(fibronectin,Fn)对体外培养的人胚肺成纤维细胞胶原mRNA合成的影响。发现Cp及Fn对成纤维细胞胶原mRNA的合成有促进作用。向培养的成纤维细胞中同时加入石英粉尘和Cp时,其刺激胶原mRNA增长的程度高于单独加入石英粉尘或Cp时的刺激作用。提示Cp对石英粉尘的促纤维化有协同作用。本实验同时证实Fn也具有类似于Cp的促纤维化的协同作用。     

实验性石棉肺病变中Ⅰ型及Ⅲ型胶原基因表达的研究

以斑点杂交法测定染溫石棉尘后30天与60天大鼠肺组织中前胶原mRNA的水平,即proα_1(Ⅰ)、proα_2(Ⅰ)、proα_1(Ⅲ)mRNA的水平,并与正常大鼠肺组织对比,结果显示,染石棉尘的肺组织中这三种mRNA显著地高于正常对照组。在染尘后60天时Ⅰ型胶原的两种mRNA仍呈上升趋势,而Ⅲ型胶原的mRNA则呈稳定状态。体外实验的结果表明溫石棉及青石棉纤维都可以刺激2BS细胞中Ⅰ、Ⅲ型胶原基因的表达。矽肺组织来源的致纤维化因子与石棉纤维都具有促进胶原基因表达的作用,其共同作用效果更強。证明这两种因素都参与调节石棉肺的纤维化作用。     

RNA干扰沉默低氧诱导因子-1α对低氧下大鼠肺动脉平滑肌细胞增殖的影响

本研究应用基因克隆技术,将合成的发卡样特异性低氧诱导因子-1α（hypoxia inducible factor-1alpha,HIF-1α）干扰寡核苷酸（siRNA）序列插入真核表达载体中,构建出特异性HIF-1α基因RNA干扰（RNAi）真核表达载体。采用组织块种植法,原代培养大鼠肺动脉平滑肌细胞（pulmonary artery smooth muscle cells,PASMCs）,将构建出的特异性HIF-1αRNAi真核表达载体转染到PASMCs;分别在常氧和低氧下进行细胞培养,采用RT-PCR检测PASMCsHIF-1αmRNA表达水平,用MTT和流式细胞仪检测细胞增殖水平,探讨低氧条件下HIF-1αRNAi真核表达载体对PASMCs增殖的影响。结果表明,低氧培养48h后,正常PASMCs和转染了HIF-1αsiRNA阴性表达载体的细胞增殖显著,HIF-1αmRNA表达水平也显著升高;而转染了HIF-1αsiRNA阳性表达质粒的细胞增殖不显著,HIF-1αmRNA表达水平较低。结果提示：HIF-1αRNAi真核表达载体能显著干扰培养的PASMCsHIF-1αmRNA表达,同时抑制低氧环境下PASMCs的增殖。     

普伐他汀对醛固酮诱导心脏成纤维细胞内皮素合成的影响

目的:探讨普伐他汀对醛固酮诱导新生大鼠心脏成纤维细胞内皮素(ET)的影响。方法:采用胰酶消化法和差速贴壁分离法获取和培养新生大鼠心脏成纤维细胞,应用放免法、流式细胞术、RT-PCR的方法分别测定醛固酮、普伐他汀以及甲羟戊酸干预下心脏成纤维细胞培养液中ET水平和心脏成纤维细胞中的ET-1含量,以及内皮素-1前体(ppET-1)mRNA的表达。结果:与正常对照组相比,醛固酮(10-7mol/L)可促进心脏成纤维细胞培养液中ET水平和心脏成纤维细胞中的ET-1含量及ppET-1 mRNA的表达,提前给予普伐他汀(10-5,10-4,10-3mol/L)能剂量依赖性地抑制醛固酮的上述作用,同时这种抑制作用可被甲羟戊酸所逆转。结论:普伐他汀可抑制醛固酮诱导的心脏成纤维细胞ppET-1mRNA表达以及ET-1的合成和分泌,其机制可能与甲羟戊酸代谢途径有关。     

串珠素表达下调参与低氧对大鼠心肌微血管内皮细胞增殖的抑制作用

低氧可以抑制内皮细胞增殖,但是其机理目前尚不清楚。串珠素在调节内皮细胞增殖中发挥着重要作用。为了探讨串珠素是否参与低氧对内皮细胞增殖的抑制,将大鼠心肌微血管内皮细胞在低氧或常氧状态下培养12 h后,用实时定量RT-PCR方法检测串珠素mRNA的表达。结果发现：低氧可以明显抑制串珠素mRNA的表达,与常氧状态下串珠素mRNA表达水平比较,差异显著（P〈0．05）。与此同时,低氧状态下或用串珠素抗体中和内源性串珠素,内皮细胞的增殖和对成纤维细胞生长因子的反应明显降低,粘着斑激酶（focal adhesion kinase,FAK）表达和细胞外信号调节激酶1／2（extracellular signal- regulated kinase,ERK1／2）活性明显下降。结果提示,串珠素表达下调可能通过抑制FAK介导的ERK1/2依赖的信号转导途径,参与低氧对大鼠心肌微血管内皮细胞增殖的抑制作用。     

低氧时肾上腺髓质素对人胚肺成纤维细胞胶原合成和转化生长因子β1表达的影响

观察低长因子β1(TGF-β1)表达的影响.体外培养人胚肺成纤维细胞,分常氧和低氧24、48、72 h组,用[3H]-脯氨酸掺入法反映细胞总胶原合成和分泌,ELISA法检测细胞上清液中TGF-β1活化蛋白质含量.低氧24、48、72 h,细胞总胶原合成和分泌分别是常氧组的125.88%和124.74%、183.44%和165.73%、152.55%和172.93%(P＜0.01).低氧24、72 h,ADM(10-7mol/L)组细胞胶原合成分泌减少了19.24%和20.76%(P＜0.01)、9.57%(P＜0.05)和10.98%(P＜0.01);低氧48 h,ADM(10-9、10-8、10-7mol/L)组胶原合成分泌分别降低了5.57%(P＜0.05)和9.19%(P＞0.05)、11.09%(P＜0.01)和14.49%(P＜0.05)、35.41%(P＜0.01)和18.57%(P＜0.05).低氧48 h,细胞培养液中TGF-β1上升了24.17%(P＜0.05),加入ADM(10-7mol/L),TGF-β1比对照组下降了17.53%(P＜0.05);低氧72 h,ADM(10-7mol/L)组TGF-β1下降了19.49%(P＜0.05).低氧时ADM通过阻碍成纤维细胞胶原合成而影响低氧性肺血管改建及损伤组织修复过程,ADM与TGF-β1可能通过相互拮抗,共同调节成纤维细胞胶原的生成.     

川芎嗪调节自发糖尿病肾病鼠Ⅲ型前胶原表达的实验研究

目的:观察川芎嗪对自发糖尿病肾病大鼠肾小球Ⅲ型前胶原基因表达的调节.方法:将实验用6月龄SPF级GK大鼠和Wistar大鼠随机分为正常对照组、糖尿病组、川芎嗪治疗组.治疗16周.观察治疗后大鼠的尿素氮、_薛肌苷、内生肌苷清除率、24小时尿蛋白排泄率,免疫组化检测肾组织Ⅲ型前胶原表达.结果:①造模组大鼠均出现肾脏功能有损害②川芎嗪能改善自发糖尿病肾病大鼠基本状况,降低糖尿病大鼠的尿素氮、血肌苷、24h尿白蛋白排泄率,增加内生肌苷清除率,Ⅲ型前胶原表达显著下调.结论:川芎嗪可通过降低Ⅲ型前胶原的表达,对肾脏起保护作用.     

缺氧和DDPH对人胚肺成纤维细胞前胶原mRNA表达的影响

用核酸原位杂交和图像分析等方法,观察直接缺氧（Ｈ）和缺氧猪肺动脉内皮细胞条件培养液（ＨＥＣＣＭ）对人胚肺成纤维细胞（ＫＭＢ１７）的前胶原ｐｒｏα１（Ⅰ）,ｐｒｏα１（Ⅲ）ｍＲＮＡ表达和抗高血压药１－（２,６－二甲基苯氧基）－２－（３,４－二甲氧基苯乙氨基）丙烷盐酸盐（ＤＤＰＨ）对此过程的影响。结果发现,Ｈ和ＨＥＣＣＭ均可使ＫＭＢ１７的两型前胶原ｍＲＮＡ表达量增高,明显高于对照组（Ｐ＜０．０１）。ＤＤＰＨ对ＨＥＣＣＭ组细胞的Ⅰ,Ⅲ两型前胶原ｍＲＮＡ表达增高均有显著的抑制作用（抑制率分别为－４３．９７％和－５６．２２％）,而对Ｈ组仅抑制ｐｒｏα１（Ⅰ）前胶原ｍＲＮＡ的过量表达（－５３．５８％）。提示缺氧可直接或通过肺动脉内皮细胞的介导,促进人胚肺成纤维细胞的Ⅰ、Ⅲ两型前胶原ｍＲＮＡ表达,ＤＤＰＨ在基因转录水平上对此过程有抑制作用     

Serology and systematics of the Ebenales and the Theales

The systematic position ofthe Ebenaceae, Sapotaceae, Styracaceae, Ochnaceae, Stachyuraceae, Dipterocarpaceae, Clusiaceae and Hypericaceae has been investigated using serological comparisons of sets of antigenic determinants. The results show that the Sytracaceae and Sapotaceae are undoubtedly more closely associated with the Actinidiaeceae and Theaceae, respectively, than with each other. We found no corresponding determinants betnween antigen systems from the Ebenaceae and systems from any other family whose relations to this family have been proposed. As discovered previously, investigations of antigen systems from the Ochnaceae, Dipterocarpaceae, Stachyuraceae, Clusiaceae and Hypericaceae are against the idea of a natural order “Theales” in which these families, or at least some of them, are combined with the Theaceae and Actinidiaceae. This paper completes our previous investigations which largely support a superorder Ericanae sensu Ehrendorfer and Takhtajan. We propose to include the Actinidiaceae and Theaceae in this superorder, assigning them a central position laong with the Sapotaceae and Sytracaeae on one side and the Primulales and Ericales on the other. Another most interesting finding is that there are corresponding determinants between antigen systems from the members of the Ericanae and representatives of the Polemoniaceae and Loasaceae.     

The Choroid Plexuses and the Barriers Between the Blood and the Cerebrospinal Fluid

1. The fluid homeostasis of the brain depends both on the endothelial blood–brain barrier and on the epithelial blood–cerebrospinal fluid (CSF) barrier located at the choroid plexuses and the outer arachnoid membrane.2. The brain has two fluid environments: the brain interstitial fluid, which surrounds the neurons and glia, and the CSF, which fills the ventricles and external surfaces of the central nervous system.3. CSF acts as a fluid cushion for the brain and as a drainage route for the waste products of cerebral metabolism.4. Recent findings suggest that CSF may also act as a third circulation conveying substances secreted into the CSF rapidly to many brain regions.     

Epigenetics and aging: the targets and the marks

'Aging epigenetics' is an emerging field that promises exciting revelations in the near future. Here we focus on the functional and biological significance of the epigenetic alterations that accumulate during aging and are important in tumorigenesis. Paradigmatic examples are provided by the global loss of DNA methylation in aging and cancer and by the promoter hypermethylation of genes with a dual role in tumor suppression and progeria, such as the Werner syndrome (WRN) and lamin A/C genes. Another twist is provided by sirtuins, a family of NAD-dependent deacetylases that act on Lys16 of histone H4, which are emerging as a link between cellular transformation and lifespan.     

Biophysics and Structure of the Patch and the Gigaseal

Interpreting channel behavior in patches requires an understanding of patch structure and dynamics, especially in studies of mechanosensitive channels. High resolution optical studies show that patch formation occurs via blebbing that disrupts normal membrane structure and redistributes in situ components including ion channels. There is a 1-2 μm region of the seal below the patch where proteins are excluded and this may consist of extracted lipids that form the gigaseal. Patch domes often have complex geometries with inhomogeneous stresses due to the membrane-glass adhesion energy (E_a), cytoskeletal forces, and possible lipid subdomains. The resting tension in the patch dome ranges from 1-4 mN/m, a significant fraction of the lytic tension of a bilayer (∼10 mN/m). Thus, all patch experiments are conducted under substantial, and uneven, resting tension that may alter the kinetics of many channels. E_a seems dominated by van der Waals attraction overlaid with a normally repulsive Coulombic force. High ionic strength pipette saline increased E_a and, surprisingly, increased cytoskeletal rigidity in cell-attached patches. Low pH pipette saline also increased E_a and reduced the seal selectivity for cations, presumably by neutralizing the membrane surface charge. The seal is a negatively charged, cation selective, space with a resistance of ∼7 gigohm/μm in 100 mM KCl, and the high resistivity of the space may result from the presence of high viscosity glycoproteins. Patches creep up the pipette over time with voltage independent and voltage dependent components. Voltage-independent creep is expected from the capillary attraction of E_a and the flow of fresh lipids from the cell. Voltage-dependent creep seems to arise from electroosmosis in the seal. Neutralization of negative charges on the seal membrane with low pH decreased the creep rate and reversed the direction of creep at positive pipette potentials.     

The efficacy of ropivacaine and bupivacaine in the caesarean section and the effect on the vital signs and the hemodynamics of the lying-in women

ObjectiveTo investigate the efficacy of ropivacaine and bupivacaine in caesarean section and vital signs and the hemodynamics of the lying-in women.MethodsA total of 480 lying-in women who were admitted to this hospital for treatment between December 2017 and June 2018 were enrolled into this study as the subjects, which were divided into the experiment group and the control group, with 240 subjects in each group. In the experiment group, subjects received the local anesthesia by infusion of 1.5 mL ropivacaine (0.75%), while those in the control group also took the local anesthesia by infusion of 1.5 mL bupivacaine (0.75%). Thereafter, we observed the differences in the anesthetic efficiency, vital signs and hemodynamics of the lying-in women between two groups.ResultsThe excellent and good rates of the anesthesia in two groups were 92.1% and 87.9%, showing no obvious difference; in the experiment group, the average arterial pressures and systolic pressures at 5 min and 10 min after combined spinal and epidural analgesia (CSEA) were all elevated when comparing to the control group (all P < 0.05); in the experiment group, the onset time was obviously extended, while duration of sensory and motor block and the duration of motor block were all shorter than those in the control group (all P < 0.05). During anesthesia, the incidence rate of the adverse reactions in the control group was 2.50%, significantly higher than 0.83% in the experiment group (P < 0.05).ConclusionDespite that ropivacaine and bupivacaine are efficient in anesthesia in the CSEA in the caesarean section, ropivacaine is more recommended for little influence on the hemodynamics, shorter duration of sensory block and motor block and low incidence rate of adverse reactions, which are conducive to the recovery and also safe to the patients.     

On the structure and dynamics of the complex of the nucleosome and the linker histone

Several different models of the linker histone (LH)–nucleosome complex have been proposed, but none of them has unambiguously revealed the position and binding sites of the LH on the nucleosome. Using Brownian dynamics-based docking together with normal mode analysis of the nucleosome to account for the flexibility of two flanking 10 bp long linker DNAs (L-DNA), we identified binding modes of the H5-LH globular domain (GH5) to the nucleosome. For a wide range of nucleosomal conformations with the L-DNA ends less than 65 Å apart, one dominant binding mode was identified for GH5 and found to be consistent with fluorescence recovery after photobleaching (FRAP) experiments. GH5 binds asymmetrically with respect to the nucleosomal dyad axis, fitting between the nucleosomal DNA and one of the L-DNAs. For greater distances between L-DNA ends, docking of GH5 to the L-DNA that is more restrained and less open becomes favored. These results suggest a selection mechanism by which GH5 preferentially binds one of the L-DNAs and thereby affects DNA dynamics and accessibility and contributes to formation of a particular chromatin fiber structure. The two binding modes identified would, respectively, favor a tight zigzag chromatin structure or a loose solenoid chromatin fiber.     

Initiating and promoting the aquatic ecosystem health concept: the Society and the Journal

Since the 1970's the management of aquatic habitats has changed from piecemeal monitoring to the ecosystem approach; this was initiated in the North American Great Lakes, comprising social, economic, and environmental aspects. The information included in this paper is based on the presentation made at the Seminar On Ecosystem Approach To Water Management held in Oslo, Norway during 1991. Recently, the multidisciplinary, holistic, and integrated concept of ecosystem health has emerged, and is being advanced for the implementation of an ecosystem approach to environmental management, which has resulted in the formation of an international society (Aquatic Ecosystem Health & Management Society) and the publication of a primary journal (Journal of Aquatic Ecosystem Health). The information has been updated to incorporate new developments and recent progress about the Society and the journal since the Oslo Seminar.