• 【基于核移植的牛心肌细胞重编程研究隔离。】 复制标题 收藏 收藏
    DOI:10.1089/clo.2006.8.150 复制DOI
    作者列表:Schwarzer M,Carnwath JW,Lucas-Hahn A,Lemme E,Kues WA,Wachsmann B,Haverich A,Martin U,Niemann H
    BACKGROUND & AIMS: :The goal of this study was to establish and validate a protocol for preparing bovine cardiomyocytes from slaughterhouse material for nuclear transfer experiments. The cardiomyocyte was selected because it is a terminally differentiated cell and strongly expresses a unique subset of genes which can be monitored during the reprogramming period. A total of 39 trials were conducted, and an optimized protocol was developed yielding individual contractile cardiomyocytes from 3-5-month-old bovine fetuses The basic protocol involves stabilization of bovine heart tissue for transportation from the slaughterhouse to the laboratory by perfusion with Custodiol. This was followed by an enzymatic dissociation with collagenase in calcium-free medium and yielded individual contractile rod-shaped cardiomyocytes. Subsequent addition of Ca2+ caused the cardiomyocytes to round up which was an essential pre-condition for drawing them into glass transfer pipettes for delivery into the perivitelline space and for efficient electrofusion with cytoplasts derived from in vitro matured bovine oocytes. The use of cardiomyocytes maintained at 37 degrees C in nuclear transfer, resulted in a significantly reduced proportion of blastocysts compared to adult fibroblasts (14.0% versus 32.7%). Storage of cardiomyocytes at 4 degrees C prior to nuclear transfer was not compatible with blastocyst development. It is expected that this system will be valuable for investigating the reprogramming of gene expression which occurs after somatic cell nuclear transfer.
    背景与目标: : 这项研究的目的是建立和验证从屠宰场材料中制备牛心肌细胞以进行核移植实验的协议。选择心肌细胞是因为它是终末分化的细胞,并且强烈表达可以在重编程期间监测的独特基因子集。总共进行了39项试验,并开发了一种优化的方案,从3-5个月大的牛胎儿中产生了单个收缩心肌细胞。基本方案涉及稳定牛心脏组织,以便通过灌注从屠宰场运输到实验室。保管二醇。随后在无钙培养基中与胶原酶酶解离,并产生单个收缩的杆状心肌细胞。随后添加Ca2会导致心肌细胞四舍五入,这是将其吸入玻璃转移移液管以输送到卵黄周围空间以及与来自体外成熟牛卵母细胞的细胞质进行有效电融合的必要前提。与成人成纤维细胞相比,在核转移中使用维持在37 ℃ 的心肌细胞导致胚泡的比例显著降低 (14.0% 对32.7%)。在核转移之前在4摄氏度下储存心肌细胞与胚泡发育不相容。预计该系统对于研究体细胞核移植后发生的基因表达的重编程将很有价值。
  • 【医学生的临床推理技能与基础科学成就和临床能力指标的关系: 结构方程模型。】 复制标题 收藏 收藏
    DOI:10.1097/01.ACM.0000236543.88782.b6 复制DOI
    作者列表:Donnon T,Violato C
    BACKGROUND & AIMS: BACKGROUND:The purpose of this study was to investigate the fit of a hypothesized model of medical students' diagnostic or clinical reasoning skills based on their aptitude for medical school, basic science achievement, and clinical competency measures. METHOD:A total of 589 medical students who received their MD from 1994 to 2002 participated in this study. Confirmatory factor analysis was used to evaluate the fit of theoretical models of clinical reasoning using measures of basic science and clinical knowledge. RESULTS:The results provided support for a three-factor model of medical student performance (Bentler's Comparative Fit Index = .905, standardized root mean squared residual = .054, root mean squared error of approximation = .105). The clinical reasoning skills of medical students were influenced by an independent relationship between latent variables of basic science achievement and clinical competency. CONCLUSION:The findings support a theoretical model of diagnostic or clinical reasoning that treats the basic science and clinical knowledge of medical students as distinct domains.
    背景与目标:
  • 【通过过继转移CD4抗肿瘤T细胞杀死原位大鼠腺癌13762需要细胞表面MHC II类分子的肿瘤表达。】 复制标题 收藏 收藏
    DOI:10.1006/cimm.1997.1122 复制DOI
    作者列表:Frey AB,Cestari S
    BACKGROUND & AIMS: CD4+ anti-tumor T cells reactive with rat adenocarcinoma 13762 kill tumor in vitro and cause regression of tumor in vivo. The role of various host immune cells in CD4+ T-cell-mediated tumor elimination in vivo was investigated by adoptive transfer of anti-tumor T cell clones to recipients that were selectively depleted of individual immune cell types. By these means, macrophages and NK cells were found to be required for tumor killing. Depletion of host CD4+ T cells, CD8+ T cells, or neutrophils was without effect on tumor elimination by anti-tumor T cells. An essential role for antigen receptor-negative NK cells is likely dependent upon secretion of IFN-gamma from NK cells since treatment of tumor recipients with anti-IFN-gamma antibody prior to adoptive transfer and tumor challenge abrogated T cell killing, resulting in progressive tumor growth. Viability of adenocarcinoma 13762 or anti-tumor T cells was unaffected by treatment with either IFN-gamma or anti-IFN-gamma antibody in vitro, but cell surface MHC class II expression was induced in tumor cells by exposure to IFN-gamma. In addition, tumor cells were isolated from tumor-bearing animals by absorption using anti-MHC class II antibody, demonstrating that 13762 tumor expresses cell surface MHC class II antigens in situ. However, if hosts were depleted of NK cells before tumor challenge, MHC class II+ tumor was not recovered. Collectively these results suggest that adenocarcinoma 13762 is eliminated by MHC class II-restricted CD4+ T cells by direct tumor killing.

    背景与目标: 与大鼠腺癌反应的CD4 + 抗肿瘤T细胞13762在体外杀伤肿瘤并在体内引起肿瘤的消退。通过将抗肿瘤T细胞克隆过继转移到选择性耗尽个体免疫细胞类型的受体,研究了各种宿主免疫细胞在体内CD4 T细胞介导的肿瘤消除中的作用。通过这些方法,发现巨噬细胞和NK细胞是杀死肿瘤所必需的。宿主CD4 T细胞,CD8 T细胞或中性粒细胞的耗竭对抗肿瘤T细胞消除肿瘤没有影响。抗原受体阴性NK细胞的重要作用可能取决于NK细胞中IFN-γ 的分泌,因为在过继转移和肿瘤挑战之前用抗IFN-γ 抗体治疗肿瘤接受者消除了T细胞杀伤,导致进行性肿瘤生长。腺癌13762或抗肿瘤T细胞的活力在体外不受IFN-γ 或抗IFN-γ 抗体治疗的影响,但细胞表面mhcii类表达通过暴露于IFN-γ 在肿瘤细胞中诱导。此外,通过使用抗MHC II类抗体吸收从荷瘤动物中分离肿瘤细胞,证明13762肿瘤原位表达细胞表面MHC II类抗原。但是,如果宿主在肿瘤激发之前耗尽了NK细胞,则MHC II类肿瘤将无法恢复。这些结果共同表明,通过直接杀伤肿瘤,MHC II类限制性CD4 T细胞消除了腺癌13762。
  • 【比较基于相机的99mTc-MAG3和24小时肌酐清除率评估肾功能。】 复制标题 收藏 收藏
    DOI:10.2214/AJR.05.1025 复制DOI
    作者列表:Esteves FP,Halkar RK,Issa MM,Grant S,Taylor A
    BACKGROUND & AIMS: OBJECTIVE:The 24-hour creatinine clearance is the standard clinical technique for measuring kidney function; however, this measurement is cumbersome and inconvenient for patients. We hypothesized that a camera-based technetium-99m mercaptoacetyltriglycine (MAG3) clearance obtained simultaneously with a standard MAG3 scan would correlate well with the 24-hour creatinine clearance and could serve as a simple marker of kidney function. MATERIALS AND METHODS:Data were obtained from a retrospective analysis of 28 patients with varying degrees of kidney dysfunction and 85 subjects evaluated for kidney donation. The MAG3 clearance was calculated using a camera-based technique without blood or urine sampling. The creatinine clearance was measured using the plasma creatinine and a 24-hour urine collection. The MAG3 and creatinine clearances were corrected for body surface area, and clearance values in healthy subjects and patients were compared using the paired Student's t test. The linear association between the MAG3 and creatinine clearances was expressed by Pearson's correlation coefficient. RESULTS:The mean MAG3 clearance in the potential kidney donors was 321 +/- 95 mL/min/1.73 m2 (95% CI, 171-546 mL/min/1.73 m2), significantly higher than the mean creatinine clearance of 152 +/- 51 mL/min/1.73 m2 (79-278 mL/min/1.73 m2, p < 0.001). The mean MAG3 clearance in patients was 153 +/- 70 mL/min/1.73 m2 (32-316 mL/min/1.73 m2) and was also significantly higher than the mean creatinine clearance of 74 +/- 36 mL/min/1.73 m2 (21-138 mL/min/1.73 m2, p < 0.001). The ratio of the mean creatinine clearance to the mean MAG3 clearance was essentially the same for volunteers and patients, 0.47 and 0.48, respectively. The Pearson's correlation between the MAG3 and creatinine clearances was 0.80 (0.72-0.86). CONCLUSION:The camera-based 99mTc-MAG3 clearance correlates well with the 24-hour creatinine clearance and can provide a simple and convenient index of kidney function.
    背景与目标:
  • 【肾脏能起到肺的作用吗?家兔缺血肾脏逆行灌注过程中的全身氧合和肾脏保存。】 复制标题 收藏 收藏
    DOI:10.1111/j.1464-410X.2006.06257.x 复制DOI
    作者列表:Humphreys MR,Ereth MH,Sebo TJ,Slezak JM,Dong Y,Blute ML,Gettman MT
    BACKGROUND & AIMS: OBJECTIVE:To investigate renal preservation by a novel method of perfusion using an oxygenated perfluorocarbon (PFC) emulsion via retrograde access to the kidney, as preserving renal function during urological surgery has been elusive, and the recognized technique of nephron-sparing surgery has increased its application and practice in modern urology. MATERIALS AND METHODS:After institutional review and approval, 30 New Zealand White rabbits were studied. In a solitary kidney model, each rabbit had the ureter catheterized before 40 min of renal artery occlusion. Each rabbit was randomized to one retrograde perfusion group, i.e. sham, normothermic PFC, chilled PFC, normothermic saline, and chilled saline. The rabbits were maintained for 2 weeks, during which renal function, urine output, systemic blood gases, weight and serum creatinine level were measured. After death, the kidneys were individually examined and graded by one renal pathologist unaware of the treatment. RESULTS:The rabbits treated with retrograde PFC perfusion (normothermic and chilled) had less change in their creatinine clearance, at 3.6 and 4.0 mL/min per kg, than the sham group, at 7.8 mL/min per kg, while also having significantly higher systemic venous oxygenation, at 26.3 and 10.0 mmHg, than the sham group, at 0.2 mmHg. Normothermic and chilled perfusion with PFC was also associated with less histological evidence of ischaemic damage, with mean (sd) scores of 13.0 (13.5) and 8.7 (4.5), respectively, than in the sham group, at 33.3 (16.8), while favourably matching the contralateral control kidney group, at 5.5 (2.3). The rabbits treated with saline retrograde perfusion also had better outcomes than the sham cohort. There were no adverse effects in any of the study arms or with the use of PFC. CONCLUSION:Retrograde oxygen delivery to the kidney through the urinary collecting system was successful in this pilot study. Renal function, laboratory and histological data indicate a trend towards renal preservation and even systemic oxygenation in the experimental groups compared with the sham rabbits, with no adverse effects attributed to this technique.
    背景与目标:
  • 【促胰液蛋白PulD的C末端结构域包含其同源伴侣蛋白的结合位点,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,称为分泌素,参与许多革兰氏阴性细菌外膜的大分子分泌。在支链淀粉酶分泌系统中,PulS (一种与外膜相关的脂蛋白) 对于PulD分泌素的完整性和适当的外膜定位都是必需的。在这里,我们显示了PulS结合位点位于PulD的C末端65个残基内。将该结构域添加到丝状噬菌体分泌素pIV或不相关的麦芽糖结合蛋白中,这两种蛋白质都依赖于PulS的稳定性。由噬菌体f1 pIV和PuID的C端结构域组成的嵌合蛋白需要适当定位的PulS来支持噬菌体组装。通过共免疫沉淀和亲和色谱法检测在pIV-PulD65嵌合体和PulS之间形成的体内复合物。
  • 【对FOXP3的分析揭示了其作为转录阻遏物的功能所需的多个结构域。】 复制标题 收藏 收藏
    DOI:10.4049/jimmunol.177.5.3133 复制DOI
    作者列表:Lopes JE,Torgerson TR,Schubert LA,Anover SD,Ocheltree EL,Ochs HD,Ziegler SF
    BACKGROUND & AIMS: :Foxp3 has been shown to be both necessary and sufficient for the development and function of naturally arising CD4+ CD25+ regulatory T cells in mice. Mutation of Foxp3 in Scurfy mice and FOXP3 in humans with IPEX results in fatal, early onset autoimmune disease and demonstrates the critical role of FOXP3 in maintaining immune homeostasis. The FOXP3 protein encodes several functional domains, including a C2H2 zinc finger, a leucine zipper, and a winged-helix/forkhead (FKH) domain. We have shown previously that FOXP3 functions as a transcriptional repressor and inhibits activation-induced IL-2 gene transcription. To characterize the role of each predicted functional domain on the in vivo activity of FOXP3, we have evaluated the location of point mutations identified in a large cohort of patients with the immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome (IPEX) and found them to cluster primarily within the FKH domain and the leucine zipper, but also present within the poorly defined N-terminal portion of the protein. The molecular functions of each of the IPEX-targeted domains were investigated. We show that FOXP3 is constitutively localized to the nucleus and this localization requires sequences at both the amino and C-terminal ends of its FKH domain. Moreover, FOXP3 was found to homodimerize through its leucine zipper. We also identify a novel functional domain within the N-terminal half of FOXP3, which is required for FOXP3-mediated repression of transcription from both a constitutively active and a NF-AT-inducible promoter. Furthermore, we demonstrate that IPEX mutations in these domains correlate with deficiencies in FOXP3 repressor function, corroborating their in vivo relevance.
    背景与目标: : Foxp3已被证明对于小鼠中自然产生的CD4 CD25调节性T细胞的发育和功能既必要又充分。在患有pex的Scurfy小鼠中Foxp3和人类中FOXP3的突变会导致致命的,早发性自身免疫性疾病,并证明了FOXP3在维持免疫稳态中的关键作用。FOXP3蛋白编码几个功能结构域,包括C2H2锌指,亮氨酸拉链和有翼螺旋/叉头 (FKH) 结构域。我们先前已经证明FOXP3作为转录阻遏物起作用并抑制激活诱导的IL-2基因转录。为了表征每个预测的功能域对FOXP3体内活性的作用,我们评估了在免疫失调,多内分泌病,肠病,X连锁综合征 (IPEX),发现它们主要聚集在FKH结构域和亮氨酸拉链内,但也存在于蛋白质定义不明确的N端部分。研究了每个pex靶向域的分子功能。我们证明FOXP3组成性地定位于细胞核,并且这种定位需要在其FKH结构域的氨基和C末端都具有序列。此外,发现FOXP3通过其亮氨酸拉链同向二聚。我们还在FOXP3的N末端一半内鉴定了一个新的功能结构域,这是FOXP3-mediated抑制组成型活性和NF-AT诱导启动子转录所必需的。此外,我们证明了这些域中的IPEX突变与FOXP3阻遏物功能的缺陷相关,从而证实了它们在体内的相关性。
  • 【前沿: 人STAT5b缺乏症中CD4 + CD25 (高) T细胞的积累和调节功能降低。】 复制标题 收藏 收藏
    DOI:10.4049/jimmunol.177.5.2770 复制DOI
    作者列表:Cohen AC,Nadeau KC,Tu W,Hwa V,Dionis K,Bezrodnik L,Teper A,Gaillard M,Heinrich J,Krensky AM,Rosenfeld RG,Lewis DB
    BACKGROUND & AIMS: :We show that STAT5b is important for the in vivo accumulation of CD4+ CD25(high) T cells with regulatory cell function. A patient homozygous for a missense A630P STAT5b mutation displayed immune dysregulation and decreased numbers of CD4+ CD25(high) T cells. STAT5b(A630P/A630P) CD4+ CD25(high) T cells had low expression of forkhead box P3 and an impaired ability to suppress the proliferation of or to kill CD4+ CD25- T cells. Expression of CD25, a component of the high-affinity IL-2R, was also reduced in response to IL-2 or after in vitro propagation. The impact of the STAT5b mutation was selective in that IL-2-mediated up-regulation of the common gamma-chain cytokine receptor and perforin, and activation-induced expressions of CD154 and IFN-gamma were normal. These results indicate that STAT5b propagates an important IL-2-mediated signal for the in vivo accumulation of functional regulatory T cells.
    背景与目标: : 我们显示STAT5b对于具有调节细胞功能的CD4 CD25 (高) T细胞的体内积累很重要。一名因错义A630P STAT5b突变而纯合的患者表现出免疫失调和CD4 CD25 (高) T细胞数量减少。STAT5b(A630P/A630P) CD4 CD25 (高) T细胞的叉头盒P3表达低,抑制或杀死CD4 cd25-t细胞的增殖能力受损。高亲和力IL-2R的组分CD25的表达也在响应IL-2或体外繁殖后降低。STAT5b突变的影响是选择性的,因为IL-2-mediated常见的 γ 链细胞因子受体和穿孔素的上调,并且激活诱导的CD154和IFN-γ 的表达正常。这些结果表明STAT5b传播了功能性调节性T细胞在体内积累的重要IL-2-mediated信号。
  • 【组成型CD40信号表型发挥了爱泼斯坦-巴尔病毒癌蛋白LMP1的体外转化功能。】 复制标题 收藏 收藏
    DOI:10.1016/j.leukres.2006.06.023 复制DOI
    作者列表:Hatzivassiliou EG,Kieff E,Mosialos G
    BACKGROUND & AIMS: :The oncoprotein LMP1 mimics an activated CD40 receptor, yet it is not known whether constitutive CD40 signaling, like LMP1, is sufficient to transform cells. Here we demonstrate that constitutive activation of the CD40 pathway by a chimeric LMP1CD40 molecule resembles the transforming function of LMP1 in inducing loss of contact inhibition and anchorage independent growth of Rat1 fibroblasts. Rat1 transformation correlates with the expression level of LMP1CD40 and depends on its ability to oligomerize. Our data provide direct evidence for the oncogenic potential of the CD40 signaling pathway, which is also established as a model-mechanism for LMP1-induced transformation.
    背景与目标: : 癌蛋白LMP1模仿活化的CD40受体,但尚不清楚组成型CD40信号传导 (如LMP1) 是否足以转化细胞。在这里,我们证明了嵌合LMP1CD40分子对CD40途径的组成型激活类似于LMP1在诱导Rat1成纤维细胞的接触抑制丧失和锚定独立生长方面的转化功能。Rat1转化与LMP1CD40的表达水平相关,并取决于其寡聚能力。我们的数据为CD40信号通路的致癌潜力提供了直接证据,CD40信号通路也被确立为LMP1-induced转化的模型机制。
  • 【吸入类固醇/长效 β2激动剂组合产品可改善成人哮喘患者的24小时肺功能。】 复制标题 收藏 收藏
    DOI:10.1186/1465-9921-7-110 复制DOI
    作者列表:Lötvall J,Langley S,Woodcock A
    BACKGROUND & AIMS: BACKGROUND:The combination of inhaled corticosteroids (ICS) and long-acting beta2-agonists (LABA) is recommended by treatment guidelines for the treatment of persistent asthma. Two such combination products, salmeterol/fluticasone propionate (SFC, Seretide GSK, UK) and formoterol/budesonide (FBC, Symbicort, AstraZeneca, UK) are commercially available. OBJECTIVES:The purpose of these studies was to evaluate and compare the duration of bronchodilation of both combination products up to 24 hours after a single dose. METHODS:Two randomised, double blind, placebo-controlled, crossover studies were performed. Study A was conducted in 33 asthmatic adults receiving 400-1200 mcg of budesonide or equivalent. Serial forced expiratory volume in one second (FEV1) was measured over 24 hours to determine the duration of effect of both SFC (50/100 mcg) and FBC (4.5/160 mcg). Study B was conducted in 75 asthmatic adults receiving 800-1200 mcg of budesonide or equivalent and comprised a 4 week run-in of 400 mcg bd Becotide followed by 4 weeks treatment with either SFC 50/100 mcg bd or FBC 4.5/160 mcg bd taken in a cross-over manner. Serial 24-hour FEV1 was measured after the first dose and the last dose after each 4-weeks treatment period to determine the offset of action of each treatment. RESULTS:In study A, a single inhalation of SFC and FBC produced a sustained bronchodilation at 16 hours with an adjusted mean increase in FEV1 from pre-dose of 0.22 L (95% CI 0.19, 0.35 L) for SFC and 0.25 L (95% CI 0.21, 0.37 L) for FBC, which was significantly greater than placebo for both treatments (-0.05 L; p < 0.001). In study B, the slope of decline in FEV1 from 2-24 hours post dose was -16.0 ml/hr for SFC and -14.2 ml/hr for FBC. The weighted mean AUC over 24 hours was 0.21 Lxmin and 0.22 Lxmin and mean change from pre-dose FEV1 at 12 hours was 0.21 L for SFC and 0.20 L for FBC respectively CONCLUSION:Both SFC and FBC produced a similar sustained bronchodilator effect which was prolonged beyond 12 hours post dose and was clearly measurable at 24 h.
    背景与目标:
  • 【蛋白质结构-功能关系的生物信息学分析: 白细胞弹性蛋白酶 (ELA2) 错义突变的案例研究。】 复制标题 收藏 收藏
    DOI:10.1002/humu.20407 复制DOI
    作者列表:Thusberg J,Vihinen M
    BACKGROUND & AIMS: :Cyclic and congenital neutropenia are caused by mutations in the human neutrophil elastase (HNE) gene (ELA2), leading to an immunodeficiency characterized by decreased or oscillating levels of neutrophils in the blood. The HNE mutations presumably cause loss of enzyme activity, consequently leading to compromised immune system function. To understand the structural basis for the disease, we implemented methods from bioinformatics to analyze all the known HNE missense mutations at both the sequence and structural level. Our results demonstrate that the 32 different mutations have diverse effects on HNE structure and function, affecting structural disorder and aggregation tendencies, stability maintaining contacts, and electrostatic properties. A large proportion of the mutations are located at conserved amino acids, which are usually essential in determining protein structure and function. The majority of the disease-causing HNE missense mutations lead to major structural changes and loss of stability in the protein. A few mutations also affect functional residues, leading into decreased catalytic activity or altered ligand binding. Our analysis reveals the putative effects of all known missense mutations in HNE, thus allowing the structural basis of cyclic and congenital neutropenia to be elucidated. We have employed and analyzed a set of some 30 different methods for predicting the effects of amino acid substitutions. We present results and experience from the analysis of the applicability of these methods in the analysis of numerous genes, proteins, and diseases to reveal protein structure-function relationships and disease genotype-phenotype correlations.
    背景与目标: : 周期性和先天性中性粒细胞减少症是由人类中性粒细胞弹性蛋白酶 (HNE) 基因 (ELA2) 突变引起的,导致免疫缺陷,其特征是血液中中性粒细胞水平降低或振荡。HNE突变可能会导致酶活性丧失,从而导致免疫系统功能受损。为了了解疾病的结构基础,我们采用了生物信息学的方法,在序列和结构水平上分析了所有已知的HNE错义突变。我们的结果表明,32种不同的突变对HNE的结构和功能具有不同的影响,影响结构紊乱和聚集趋势,保持接触的稳定性和静电特性。大部分突变位于保守的氨基酸,这通常是确定蛋白质结构和功能的关键。大多数引起疾病的HNE错义突变会导致蛋白质的主要结构变化和稳定性丧失。一些突变也会影响功能残基,导致催化活性降低或配体结合改变。我们的分析揭示了HNE中所有已知的错义突变的推定作用,从而阐明了周期性和先天性中性粒细胞减少症的结构基础。我们已经采用并分析了一组30种不同的方法来预测氨基酸取代的影响。我们介绍了这些方法在众多基因,蛋白质和疾病分析中的适用性分析的结果和经验,以揭示蛋白质结构-功能关系和疾病基因型-表型相关性。
  • 【选择性临床超声信号介导两种人前列腺癌细胞系的差异基因转移和表达: LnCap和PC-3。】 复制标题 收藏 收藏
    DOI:10.1006/bbrc.1997.6578 复制DOI
    作者列表:Tata DB,Dunn F,Tindall DJ
    BACKGROUND & AIMS: Low intensity ultrasound signals, similar to that employed in clinical therapy, are found to mediate differential gene transfer and expression of the Green Fluorescence Protein (GFP) reporter in two human prostate cancer cell lines, LnCap and PC-3. Cell suspensions in the presence or in the absence of GFP (44.5nM) were treated at 37 degrees C under a standing wave condition. Cells were exposed to either continuous wave, 932.7kHz ultrasound, or to several independent bursts, each burst comprising a 20% duty cycle (932.7kHz) sine wave. The burst "repetition" frequency was varied from 10Hz to 10kHz in several different experiments and each treatment received a net identical ultrasound energy exposure. Transient GFP expression levels in viable cells were monitored by flow cytometry. The findings revealed a strong ultrasound tone-burst frequency dependence on the transfection efficiencies. Interestingly, the ultrasound signal parameters which are routinely employed in clinical therapy did not yield any statistically significant enhancement in transfection efficiency relative to their sham counterparts.

    背景与目标: 发现与临床治疗中使用的低强度超声信号相似,可介导两种人前列腺癌细胞系LnCap和PC-3中的差异基因转移和绿色荧光蛋白 (GFP) 报告基因的表达。在驻波条件下,在37 ℃ 下处理存在或不存在GFP (44.5nm) 的细胞悬浮液。将细胞暴露于连续波、932.7khz超声波或几个独立的突发,每个突发包括20% 占空比 (932.7khz) 正弦波。在几个不同的实验中,突发 “重复” 频率从10Hz到10kHz不等,并且每种处理均获得净相同的超声能量暴露。通过流式细胞术监测活细胞中的瞬时GFP表达水平。研究结果表明,超声音调爆发频率对转染效率有很强的依赖性。有趣的是,与假手术相比,临床治疗中常规使用的超声信号参数在转染效率上没有任何统计学上的显着提高。
  • 【轻度中风患者的催乳素,皮质醇分泌和甲状腺功能。】 复制标题 收藏 收藏
    DOI:10.1055/s-2006-950505 复制DOI
    作者列表:Theodoropoulou A,Metallinos IC,Elloul J,Taleli P,Lekka N,Vagenakis AG,Kyriazopoulou V
    BACKGROUND & AIMS: :Different attempts were made to identify the variables that may be involved in the clinical course of cerebrovascular ischemia. In the case of stroke with mild severity (SMS), the clinical significance of neuroendocrine changes as well as of post-stroke depression (PSD) remains unknown. We therefore evaluated the presence of neuroendocrine changes in the acute and post-acute phase of SMS, and their potential role during convalescence. Serum cortisol, T4, T3, FT4, FT3, TSH and PRL levels were measured in 17 euthyroid patients with stroke on admission (day 1), following morning (day 2), 7 days and 3 months later. TSH and PRL secretion after TRH test were measured. Stroke severity on admission was determined by Scandinavian Stroke Scale (SSS). Montgomery-Asberg Depression Rating Scale (Madrs) was used for assessment of post-stroke depression. On admission, TSH and T3, were within normal limits and were greater compared to values on day 2. Lower basal TSH and decreased TSH response to TRH on day 2, were associated with stroke of greater severity. Delta-PRL after TRH on day 2 was higher in patients who develop PSD. Changes in serum thyroid hormones in SMS, reflects those of non-thyroidal illness. A mild stimulation of hypothalamic-pituitary-adrenal axis was detected. We provide evidence that PRL response to TRH, in the acute phase of stroke may be used as an index for early detection of PSD.
    背景与目标: : 进行了不同的尝试来确定可能与脑血管缺血的临床过程有关的变量。对于轻度严重程度 (SMS) 的中风,神经内分泌变化以及卒中后抑郁 (PSD) 的临床意义仍然未知。因此,我们评估了SMS急性期和急性期后神经内分泌变化的存在及其在恢复期中的潜在作用。在入院时 (第1天),第二天 (第2天),7天和3个月后的17例甲状腺功能正常的中风患者中测量了血清皮质醇,T4,T3,FT4,FT3,TSH和PRL水平。TRH试验后测量TSH和PRL分泌。入院时卒中严重程度由斯堪的纳维亚卒中量表 (SSS) 确定。Montgomery-Asberg抑郁量表 (Madrs) 用于评估中风后抑郁。入院时,TSH和T3在正常范围内,与第2天的值相比更高。在第2天,较低的基础TSH和对TRH的TSH反应降低与严重程度更高的中风有关。发生PSD的患者在TRH后第2天的Delta-PRL较高。SMS中血清甲状腺激素的变化反映了非甲状腺疾病的变化。检测到下丘脑-垂体-肾上腺轴的轻度刺激。我们提供的证据表明,在中风急性期PRL对TRH的反应可以用作早期发现PSD的指标。
  • 【细胞质基因表达系统增强阳离子脂质体介导的体内基因转移到小鼠大脑的效率。】 复制标题 收藏 收藏
    DOI:10.1006/bbrc.1997.6568 复制DOI
    作者列表:Mizuguchi H,Nakagawa T,Morioka Y,Imazu S,Nakanishi M,Kondo T,Hayakawa T,Mayumi T
    BACKGROUND & AIMS: Development of methodologies for gene transfer into the central nervous system (CNS) is important for fundamental research as well as clinical studies for gene therapy. Cationic liposomes (CL) are attractive vectors because of their safety and ease of use. However, to date only low rates of success have been reported. We succeeded in obtaining high transfection efficiencies into the newborn mouse brain in vivo by CL and a cytoplasmic gene expression system based on T7 RNA polymerase and T7 RNA polymerase- and the luciferase-gene with the T7 promoter sequence. This system showed an efficiency rate 2 orders of magnitude higher than the standard system, which used CL and luciferase genes with a Rous sarcoma virus promoter, pRSVL. In addition, in vitro experiments using LLCMK2 cells showed that cytoplasmic gene expression occurred rapidly (within 6 h) after transfection. In contrast, pRSVL required 24-48 h for induction of luciferase expression. Our results suggest that the cytoplasmic gene expression system is useful for gene delivery into the CNS.

    背景与目标: 开发将基因转移到中枢神经系统 (CNS) 的方法对于基因治疗的基础研究和临床研究至关重要。阳离子脂质体 (CL) 是有吸引力的载体,因为它们的安全性和易用性。然而,迄今为止,只有低成功率的报道。我们成功地通过CL和基于T7 RNA聚合酶和T7 RNA聚合酶以及具有T7启动子序列的荧光素酶基因的细胞质基因表达系统在体内获得了高转染效率。该系统的效率比标准系统高2个数量级,标准系统使用具有Rous肉瘤病毒启动子pRSVL的CL和荧光素酶基因。此外,使用LLCMK2细胞的体外实验表明,转染后细胞质基因表达迅速 (在6小时内) 发生。相反,pRSVL需要24-48小时才能诱导荧光素酶表达。我们的结果表明,细胞质基因表达系统可用于将基因传递到CNS中。
  • 【Polo盒子从地穴中出来: PLK功能和进化的新视角。】 复制标题 收藏 收藏
    DOI:10.1016/j.str.2012.10.008 复制DOI
    作者列表:Jana SC,Bazan JF,Bettencourt-Dias M
    BACKGROUND & AIMS: :Polo-like kinases (PLKs) are marked by C-terminal polo box modules with critical protein interaction and subcellular targeting roles. Slevin et al. in this issue of Structure reveal the architecture of a hidden set of polo boxes from the divergent PLK4, a critical player in centrosome duplication, shedding new light on the evolution of PLKs and their functionally related kinase ZYG-1.
    背景与目标: : Polo样激酶 (plk) 由C末端polo盒模块标记,具有关键的蛋白质相互作用和亚细胞靶向作用。Slevin等人在本期《结构》中揭示了来自不同PLK4的一组隐藏的polo盒子的架构,PLK4是中心体复制的关键参与者,为plk及其功能相关激酶ZYG-1的演变提供了新的启示。

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