• 【异四聚体肌氨酸氧化酶中稳定的黄素硫醇盐加合物的鉴定。】 复制标题 收藏 收藏
    DOI:10.1016/j.jmb.2006.07.053 复制DOI
    作者列表:Hynson RM,Mathews FS,Schuman Jorns M
    BACKGROUND & AIMS: :Heterotetrameric sarcosine oxidase (TSOX) is a complex bifunctional flavoenzyme that contains two flavins. Most of the FMN in recombinant TSOX is present as a covalent adduct with an endogenous ligand. Enzyme denaturation disrupts the adduct, accompanied by release of a stoichiometric amount of sulfide. Enzyme containing>or=90% unmodified FMN is prepared by displacement of the endogenous ligand with sulfite, a less tightly bound competing ligand. Reaction of adduct-depleted TSOX with sodium sulfide produces a stable complex that resembles the endogenous TSOX adduct and known 4a-S-cysteinyl flavin adducts. The results provide definitive evidence for sulfide as the endogenous TSOX ligand and strongly suggest that the modified FMN is a 4a-sulfide adduct. A comparable reaction with sodium sulfide is not detected with other flavoprotein oxidases. A model of the postulated TSOX adduct suggests that it is stabilized by nearby residues that may be important in the electron transferase/oxidase function of the coenzyme.
    背景与目标: :异四聚体肌氨酸氧化酶(TSOX)是一种复杂的双功能黄素酶,其中含有两个黄素。重组TSOX中的大多数FMN以与内源性配体的共价加合物形式存在。酶变性会破坏加合物,并释放出化学计量的硫化物。通过用亚硫酸盐(一种不太紧密结合的竞争性配体)置换内源配体来制备含≥90%或未修饰的FMN的酶。耗尽加合物的TSOX与硫化钠的反应产生了一种稳定的络合物,类似于内源性TSOX加合物和已知的4a-S-半胱氨酰黄素加合物。结果为硫化物作为内源性TSOX配体提供了确凿的证据,并强烈表明修饰的FMN是4a-硫化物加合物。其他黄素蛋白氧化酶未检测到与硫化钠可比的反应。假定的TSOX加合物的模型表明它被附近的残基稳定了,这些残基可能对辅酶的电子转移酶/氧化酶功能很重要。
  • 【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,这在静态噪声中表现得更好。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。
  • 【使用ANOVA和Taguchi方法进行乳腺肿瘤识别的生物势方程的参数研究。】 复制标题 收藏 收藏
    DOI:10.1007/s11517-005-0006-0 复制DOI
    作者列表:Ng EY,Ng WK
    BACKGROUND & AIMS: :Extensive literatures have shown significant trend of progressive electrical changes according to the proliferative characteristics of breast epithelial cells. Physiologists also further postulated that malignant transformation resulted from sustained depolarization and a failure of the cell to repolarize after cell division, making the area where cancer develops relatively depolarized when compared to their non-dividing or resting counterparts. In this paper, we present a new approach, the Biofield Diagnostic System (BDS), which might have the potential to augment the process of diagnosing breast cancer. This technique was based on the efficacy of analysing skin surface electrical potentials for the differential diagnosis of breast abnormalities. We developed a female breast model, which was close to the actual, by considering the breast as a hemisphere in supine condition with various layers of unequal thickness. Isotropic homogeneous conductivity was assigned to each of these compartments and the volume conductor problem was solved using finite element method to determine the potential distribution developed due to a dipole source. Furthermore, four important parameters were identified and analysis of variance (ANOVA, Yates' method) was performed using design (n = number of parameters, 4). The effect and importance of these parameters were analysed. The Taguchi method was further used to optimise the parameters in order to ensure that the signal from the tumour is maximum as compared to the noise from other factors. The Taguchi method used proved that probes' source strength, tumour size and location of tumours have great effect on the surface potential field. For best results on the breast surface, while having the biggest possible tumour size, low amplitudes of current should be applied nearest to the breast surface.
    背景与目标: :大量文献显示,根据乳腺上皮细胞的增殖特性,进行性电变化的显着趋势。生理学家还进一步假设,恶性转化是由于持续的去极化和细胞分裂后细胞无法重新极化所致,因此与非分裂或静止状态的癌症相比,癌症发展的区域相对去极化了。在本文中,我们提出了一种新的方法,即Biofield Diagnostic System(BDS),它可能具有增强乳腺癌诊断过程的潜力。该技术基于分析皮肤表面电势以鉴别诊断乳房异常的功效。通过将乳房视为仰卧状态下的半球,各层厚度不相等,我们开发了一个接近实际的女性乳房模型。各向同性的各向同性电导率分配给这些隔室,并使用有限元方法解决了体积导体问题,以确定由于偶极子源而产生的电势分布。此外,确定了四个重要参数,并使用设计进行了方差分析(ANOVA,Yates方法)(n =参数数量4)。分析了这些参数的作用和重要性。 Taguchi方法进一步用于优化参数,以确保与其他因素产生的噪声相比,来自肿瘤的信号最大。使用的Taguchi方法证明了探针的源强度,肿瘤大小和肿瘤位置对表面电势场有很大的影响。为了在乳腺表面获得最佳效果,同时应尽可能增大肿瘤的大小,应在最靠近乳腺表面的地方施加较小的电流。
  • 【铜绿假单胞菌的广泛基因组可塑性通过临床分离株中新基因的鉴定和分布研究揭示。】 复制标题 收藏 收藏
    DOI:10.1128/IAI.00546-06 复制DOI
    作者列表:Shen K,Sayeed S,Antalis P,Gladitz J,Ahmed A,Dice B,Janto B,Dopico R,Keefe R,Hayes J,Johnson S,Yu S,Ehrlich N,Jocz J,Kropp L,Wong R,Wadowsky RM,Slifkin M,Preston RA,Erdos G,Post JC,Ehrlich GD,Hu FZ
    BACKGROUND & AIMS: :The distributed genome hypothesis (DGH) states that each strain within a bacterial species receives a unique distribution of genes from a population-based supragenome that is many times larger than the genome of any given strain. The observations that natural infecting populations are often polyclonal and that most chronic bacterial pathogens have highly developed mechanisms for horizontal gene transfer suggested the DGH and provided the means and the mechanisms to explain how chronic infections persist in the face of a mammalian host's adaptive defense mechanisms. Having previously established the validity of the DGH for obligate pathogens, we wished to evaluate its applicability to an opportunistic bacterial pathogen. This was accomplished by construction and analysis of a highly redundant pooled genomic library containing approximately 216,000 functional clones that was constructed from 12 low-passage clinical isolates of Pseudomonas aeruginosa, 6 otorrheic isolates and 6 from other body sites. Sequence analysis of 3,214 randomly picked clones (mean insert size, approximately 1.4 kb) from this library demonstrated that 348 (10.8%) of the clones were unique with respect to all genomic sequences of the P. aeruginosa prototype strain, PAO1. Hypothetical translations of the open reading frames within these unique sequences demonstrated protein homologies to a number of bacterial virulence factors and other proteins not previously identified in P. aeruginosa. PCR and reverse transcription-PCR-based assays were performed to analyze the distribution and expression patterns of a 70-open reading frame subset of these sequences among 11 of the clinical strains. These sequences were unevenly distributed among the clinical isolates, with nearly half (34/70) of the novel sequences being present in only one or two of the individual strains. Expression profiling revealed that a vast majority of these sequences are expressed, strongly suggesting they encode functional proteins.
    背景与目标: :分布式基因组假设(DGH)指出,细菌物种中的每个菌株都从基于种群的超基因组中获得独特的基因分布,其比任何给定菌株的基因组都要大很多倍。自然感染人群通常是多克隆的,大多数慢性细菌病原体具有高度发展的水平基因转移机制的观察结果提示了DGH,并提供了解释哺乳动物宿主面对适应性防御机制时慢性感染如何持续存在的手段和机制。先前已确定DGH对专性病原体的有效性,我们希望评估其对机会细菌病原体的适用性。这是通过构建和分析包含约216,000个功能性克隆的高度冗余的集合基因组文库完成的,该文库由铜绿假单胞菌的12种低通道临床分离株,6种耳泻分离株和6个其他身体部位构建而成。对来自该文库的3,214个随机挑选的克隆(平均插入片段大小,约1.4 kb)进行序列分析,结果表明,对于铜绿假单胞菌原型菌株PAO1的所有基因组序列,其中348个(10.8%)克隆是唯一的。在这些独特序列内的开放阅读框的假想翻译证明了与许多细菌毒力因子和以前在铜绿假单胞菌中未鉴定出的其他蛋白质的蛋白质同源性。进行了基于PCR和逆转录PCR的分析,以分析这些序列的70个开放阅读框子集在11种临床菌株中的分布和表达模式。这些序列在临床分离株之间分布不均,只有一半或34个新序列出现在一个或两个单独的菌株中。表达谱分析表明这些序列中的绝大多数都被表达,强烈暗示它们编码功能蛋白。
  • 【Plectin转录本多样性:具有不同的第一个编码外显子和无杆同种型的变异体的鉴定和组织分布。】 复制标题 收藏 收藏
    DOI:10.1006/geno.1997.4724 复制DOI
    作者列表:Elliott CE,Becker B,Oehler S,Castañón MJ,Hauptmann R,Wiche G
    BACKGROUND & AIMS: :Plectin is a widely expressed protein that is very large in size and that has all the attributes of a multifunctional crosslinking and organizing element of the cytoskeleton. It displays a multidomain structure, versatile binding activities, and subcellular localizations that enable it to strengthen cells against mechanical stress forces. Moreover, hereditary gene defects in plectin cause epidermolysis bullosa simplex (EBS)-MD, a severe skin blistering disease with muscular dystrophy. Here we report the analysis of the exonintron organization of the rat plectin gene and the identification of several different isoforms on the transcriptional level. We show that of 35 coding exons identified, 4 serve as alternative first exons splicing into the same successive exon 2, which is the first of 7 exons encoding a highly conserved actin-binding domain. RNase protection mapping of transcripts containing 3 of the identified 4 alternate first exons revealed their coexpression in rat glioma C6 cells and in a series of different rat tissues that we examined. Significant variations in expression levels of first exons indicated the possibility of tissue-specific promoter usage. In addition, plectin splice variants lacking exon 31 (> 3 kb), which encodes the entire rod domain of the molecule, were identified in a variety of rat tissues. This study provides first insights into a complex plectin gene regulatory machinery with similarities to that of dystrophin.
    背景与目标: :Plectin是一种广泛表达的蛋白质,其大小非常大,具有细胞骨架的多功能交联和组织元素的所有属性。它显示了多域结构,多功能的结合活性和亚细胞定位,使其能够增强细胞抵抗机械应力的能力。此外,凝集素中的遗传基因缺陷会导致大疱性表皮松解症(EBS)-MD,这是一种严重的皮肤起泡性疾病,并伴有肌肉营养不良。在这里,我们报告对大鼠plectin基因外显子组织的分析,并在转录水平上鉴定了几种不同的同工型。我们显示,在确定的35个编码外显子中,有4个充当剪接成同一连续外显子2的替代第一个外显子,这是编码高度保守的肌动蛋白结合域的7个外显子中的第一个。包含已鉴定的4个交替的第一个外显子中的3个的转录本的RNase保护图谱揭示了它们在大鼠神经胶质瘤C6细胞和我们检查的一系列不同大鼠组织中的共表达。第一外显子表达水平的显着变化表明使用组织特异性启动子的可能性。另外,在多种大鼠组织中鉴定出缺乏外显子31(> 3 kb)的plectin剪接变体,该外显子编码该分子的整个杆结构域。这项研究提供了与肌营养不良蛋白相似的复杂血凝素基因调控机制的初步见解。
  • 【XLerk的鉴定,XLerk是非洲爪蟾中胚层诱导和神经发生过程中受调节的Eph家族配体。】 复制标题 收藏 收藏
    DOI:10.1038/sj.onc.1201082 复制DOI
    作者列表:Jones TL,Karavanova I,Chong L,Zhou RP,Daar IO
    BACKGROUND & AIMS: We have isolated and characterized the first Xenopus transmembrane Eph ligand, XLerk (Xenopus Ligand for Eph Receptor Tyrosine Kinases). While this ligand has 72% identity with the closest mammalian family member, Lerk-2, it is the cytoplasmic domain of this molecule that is the most conserved domain with 95% identity. XLerk exists as a maternally expressed mRNA, however, expression of transcripts and protein increase during gastrulation and again in the late swimming tadpole stage. In the adult, XLerk is expressed at low levels in most adult tissues with increased levels observed in the kidney, oocytes, ovary and testis. While low levels of XLerk expression are observed in the adult brain, in situ hybridization analysis demonstrates prominent expression in the developing olfactory system, retina, hindbrain, cranial ganglia, and somites. Furthermore, we have shown that XLerk transcripts are significantly elevated during mesoderm induction caused by activin and FGF, but not during noggin-induced neuralization. These results suggest a role for XLerk in the developing mesenchymal and nervous tissue.

    背景与目标: 我们已经分离并鉴定了第一个非洲爪蟾跨膜Eph配体XLerk(用于Eph受体酪氨酸激酶的非洲爪蟾配体)。尽管该配体与最接近的哺乳动物家族成员Lerk-2具有72%的同一性,但该分子的胞质结构域是具有95%的同一性的最保守的结构域。 XLerk作为母体表达的mRNA存在,但是转录的表达和蛋白质在胃排泄过程中以及游泳increase后期再次增加。在成年人中,XLerk在大多数成年人组织中低水平表达,在肾脏,卵母细胞,卵巢和睾丸中观察到水平升高。尽管在成年大脑中观察到了低水平的XLerk表达,但原位杂交分析显示出在发育中的嗅觉系统,视网膜,后脑,颅神经节和体节中突出表达。此外,我们已经表明,在由激活素和FGF引起的中胚层诱导过程中,XLerk转录物显着升高,但在头蛋白诱导的神经化过程中却没有。这些结果表明XLerk在发育中的间充质和神经组织中的作用。

  • 【鉴定病因不明的原发性B细胞免疫缺陷儿童的人磷酸肌醇3-激酶p110delta基因的变异。】 复制标题 收藏 收藏
    DOI:10.1111/j.1744-313X.2006.00627.x 复制DOI
    作者列表:Jou ST,Chien YH,Yang YH,Wang TC,Shyur SD,Chou CC,Chang ML,Lin DT,Lin KH,Chiang BL
    BACKGROUND & AIMS: :Our recent study demonstrated that defects in p110delta result in B-cell immunodeficiency that is very similar to that observed in BTK-deficient mice. We revealed that the p110delta fit the B-cell signal transduction complex and played a non-redundant role in the development and function of B cells. In humans, most children with primary B-cell immunodeficiency have mutations in the BTK, whereas a few have defects in the components of the B-cell signal transduction complex. But little is known about the genetic variation of p110delta in children with defects in B-cell immunodeficiency of unknown aetiology. Sixteen patients from 15 unrelated families and 112 normal controls underwent sequence analysis to identify genetic variations of the p110delta. Allele frequency in each group was also analysed and compared. We identified five single base-pair polymorphic nucleotide exchanges in both patient and control groups with similar allele frequencies, which did not contribute to the immunodeficiency. Three of them are novel (m.953A>G, m.1200C>T and m.1561A>G), and the m.953A>G and m.1561A>G nucleotide exchanges are non-synonymous (N253S and T456A, respectively). The novel m.1561A>G was in complete linkage disequilibrium with the known m.873A>G in our study of Taiwanese group. In addition, one novel single base-pair missense mutation, m.3256G>A (E1021K), was identified in one boy with typical clinical features of primary B-cell immunodeficiency and could not be found in either his family or the normal control population. By atomic structural analysis of the amino acid as well as the alignment comparison between species, it resulted in the replacement of the negative-charged amino acid E with the positive-charged amino acid K at codon 1021, located in the highly conservative and important catalytic functional domain. Our findings could shed light on further understanding the polymorphisms of p110delta in B-cell immunodeficiency and different populations. Moreover, the 3256G>A missense mutation raised the attention and warranted further extensive analysis to elucidate the role of p110delta in human immunodeficiency.
    背景与目标: :我们最近的研究表明,p110delta中的缺陷会导致B细胞免疫缺陷,这与在BTK缺陷小鼠中观察到的缺陷非常相似。我们发现p110delta适合B细胞信号转导复合物,并且在B细胞的发育和功能中起着非冗余的作用。在人类中,大多数患有原发性B细胞免疫缺陷的儿童在BTK中都有突变,而少数儿童在B细胞信号转导复合物中的成分存在缺陷。但是对于病因不明的B细胞免疫缺陷的儿童p110δ的遗传变异知之甚少。来自15个无关家庭和112个正常对照的16位患者接受了序列分析,以鉴定p110delta的遗传变异。还对每组中的等位基因频率进行了分析和比较。我们在患者和对照组中确定了五个具有相似等位基因频率的单碱基​​对多态性核苷酸交换,这对免疫缺陷没有帮助。其中三个是新颖的(m.953A> G,m.1200C> T和m.1561A> G),而m.953A> G和m.1561A> G核苷酸交换是非同义的(分别为N253S和T456A) )。在我们对台湾人的研究中,小说m.1561A> G与已知的m.873A> G处于完全连锁不平衡状态。此外,在一个男孩中发现了一个新颖的单碱基对错义突变,m.3256G> A(E1021K),该男孩具有原发性B细胞免疫缺陷的典型临床特征,在其家人或正常对照人群中均未发现。通过氨基酸的原子结构分析以及物种之间的比对比较,结果发现位于高度保守且重要的催化分子1021密码子上的负电荷氨基酸E被正电荷氨基酸K取代。功能域。我们的发现可能有助于进一步了解B细胞免疫缺陷和不同人群中p110delta的多态性。此外,3256G> A错义突变引起了人们的注意,并需要进行进一步的广泛分析以阐明p110delta在人类免疫缺陷中的作用。
  • 【快速鉴定UCA1是人类膀胱癌的非常敏感和特异的独特标记。】 复制标题 收藏 收藏
    DOI:10.1158/1078-0432.CCR-06-0134 复制DOI
    作者列表:Wang XS,Zhang Z,Wang HC,Cai JL,Xu QW,Li MQ,Chen YC,Qian XP,Lu TJ,Yu LZ,Zhang Y,Xin DQ,Na YQ,Chen WF
    BACKGROUND & AIMS: PURPOSE:The most common genitourinary malignancy in China is bladder transitional cell carcinoma (TCC). Early diagnosis of new and recurrent bladder cancers, followed by timely treatment, will help decrease mortality. There are currently no satisfactory markers for bladder cancer available in clinics. Better diagnostic methods are highly demanded. EXPERIMENTAL DESIGN:In this research, we have used comprehensive expressed sequence tag analysis, serial analysis of gene expression, and microarray analysis and quickly discovered a candidate marker, urothelial carcinoma associated 1 (UCA1). The UCA1 gene was characterized and its performance as a urine marker was analyzed by reverse transcription-PCR with urine sediments. A total of 212 individuals were included in this study, 94 having bladder cancers, 33 ureter/pelvic cancers, and 85 normal and other urinary tract disease controls. RESULTS:UCA1 was identified as a novel noncoding RNA gene dramatically up-regulated in TCC and it is the most TCC-specific gene yet identified. The full-length cDNA was 1,439 bp, and sequence analysis showed that it belonged to the human endogenous retrovirus H family. Clinical tests showed that UCA1 assay was highly specific (91.8%, 78 of 85) and very sensitive (80.9%, 76 of 94) in the diagnosis of bladder cancer and was especially valuable for superficial G2-G3 patients (sensitivity 91.1%, 41 of 45). It showed excellent differential diagnostic performance in various urinary tract diseases without TCC. CONCLUSIONS:UCA1 is a very sensitive and specific unique marker for bladder cancer. It could have important implications in postoperative noninvasive follow-up. This research also highlights a shortcut to new cancer diagnostic assays through integration of in silico isolation methods with translational clinical tests based on RNA detection protocols.
    背景与目标: 目的:在中国最常见的泌尿生殖系统恶性肿瘤是膀胱移行细胞癌(TCC)。尽早诊断出新发和复发性膀胱癌,然后及时进行治疗,将有助于降低死亡率。目前,临床上尚无令人满意的膀胱癌标记物。迫切需要更好的诊断方法。
    实验设计:在这项研究中,我们使用了全面的表达序列标签分析,基因表达的序列分析和微阵列分析,并迅速发现了候选标记物,尿路上皮癌相关1(UCA1)。对UCA1基因进行了表征,并通过逆转录PCR与尿沉渣一起分析了其作为尿液标记物的性能。这项研究总共包括212位个体,其中94位患有膀胱癌,33位输尿管/盆腔癌以及85位正常和其他泌尿系统疾病对照。
    结果:UCA1被鉴定为TCC中上调的新型非编码RNA基因,是迄今鉴定到的最具TCC特异性的基因。全长cDNA为1439 bp,序列分析表明它属于人内源性逆转录病毒H家族。临床测试表明,UCA1检测对膀胱癌的诊断具有高度特异性(91.8%,78 of 85)和非常敏感(80.9%,76 of 94),对于浅表G2-G3患者特别有价值(敏感性91.1%,41) 45)。在没有TCC的各种泌尿系统疾病中,它表现出出色的鉴别诊断性能。
    结论:UCA1是膀胱癌非常敏感和特异的独特标志物。它可能对术后无创性随访产生重要影响。这项研究还突出了通过将计算机隔离方法与基于RNA检测方案的转化临床测试相集成的新癌症诊断测定方法的捷径。
  • 【通过PCR鉴定编码多种应答调节剂的基因。】 复制标题 收藏 收藏
    DOI:10.1099/00221287-143-5-1513 复制DOI
    作者列表:Morel-Deville F,Ehrlich SD,Morel P
    BACKGROUND & AIMS: Environmental sensing in bacteria often involves the concerted action of sensor kinases and response regulators. Degenerate oligonucleotide primers were designed on the basis of amino acid similarity in the response regulators of these two-component systems. The primers were used in PCR to specifically amplify an internal DNA segment corresponding to the receiver module domain from genes encoding response regulators. Amplification products of the expected size were obtained from 12 different Gram-positive and Gram-negative bacteria. Sequence analysis revealed that 22 DNA fragments, which clearly originated from response regulator genes, were amplified from Escherichia coli, Agrobacterium tumefaciens, Bacillus subtilis and Lactobacillus bulgaricus. In each of these four species the receiver module of putative response regulator genes, which do not seem to be related to any of the already characterized genes, was identified. This simple and powerful method is therefore particularly useful for discovering new signal transduction systems which cannot be revealed by usual genetic studies.

    背景与目标: 细菌中的环境感测通常涉及传感器激酶和响应调节剂的协同作用。简并寡核苷酸引物是根据这些两组分系统的响应调节剂中的氨基酸相似性设计的。将引物用于PCR,以从编码反应调节剂的基因中特异性扩增对应于受体模块结构域的内部DNA片段。从12种不同的革兰氏阳性和革兰氏阴性细菌中获得了预期大小的扩增产物。序列分析表明,从大肠杆菌,根癌土壤杆菌,枯草芽孢杆菌和保加利亚乳杆菌中扩增了22个明显来自响应调节基因的DNA片段。在这四个物种的每一个中,鉴定出似乎与任何已经表征的基因都不相关的推定应答调节基因的接收模块。因此,这种简单而强大的方法对于发现通常的遗传学研究无法揭示的新信号转导系统特别有用。

  • 【鉴定和分离粘附性糖蛋白纤连蛋白的胶原结合片段。】 复制标题 收藏 收藏
    DOI:10.1073/pnas.76.3.1160 复制DOI
    作者列表:Hahn LH,Yamada KM
    BACKGROUND & AIMS: :We have identified and purified a polypeptide region containing the collagen-binding site of the adhesive glycoprotein fibronectin. Chicken cellular fibronectin isolated from cultured embryonic fibroblasts was permitted to bind to gelatin coupled to agarose beads and was then digested extensively with chymotrypsin. A prominent 40,000-dalton fragment of fibronectin consisting of a single polypeptide chain was detected by sodium dodecyl sulfate/polyacrylamide gel electrophoresis of material remaining bound to the gelatin-agarose. This fragment appeared within 10 min after the digestion was initiated and persisted for more than 20 hr. This proteolytic fragment was isolated in electrophoretically pure form and retained its affinity for collagen. Plasma fibronectins from chicken and human blood also contained collagen-binding proteolytic fragments of similar size. This finding suggest that the collagen-binding sites of cellular and plasma fibronectins are homologous.
    背景与目标: :我们已经鉴定并纯化了包含粘附性糖蛋白纤连蛋白的胶原蛋白结合位点的多肽区域。从培养的胚胎成纤维细胞中分离出的鸡细胞纤连蛋白被允许结合到与琼脂糖珠上偶联的明胶上,然后用胰凝乳蛋白酶进行广泛消化。通过十二烷基硫酸钠/聚丙烯酰胺凝胶电泳,检测仍与明胶-琼脂糖结合的物质,可检测到由单个多肽链组成的纤连蛋白的40,000道尔顿(Dalton)突出片段。该片段在开始消化后的10分钟内出现,并持续超过20小时。该蛋白水解片段以电泳纯的形式分离,并保留了其对胶原蛋白的亲和力。来自鸡和人血的血浆纤连蛋白也含有相似大小的胶原结合蛋白水解片段。该发现表明细胞和血浆纤连蛋白的胶原结合位点是同源的。
  • 【三种厌氧菌鉴定系统的比较评估。】 复制标题 收藏 收藏
    DOI:10.1128/JCM.22.1.52-55.1985 复制DOI
    作者列表:Murray PR,Weber CJ,Niles AC
    BACKGROUND & AIMS: :The accuracy of two new 4-h identification systems for anaerobes, the AN-IDENT (Analytab Products, Plainview, N.Y.) and the RapID ANA (Innovative Diagnostic Systems, Inc., Atlanta, Ga.) was compared with that of the API 20A system (Analytab Products). A total of 132 clinical isolates were tested in each of the three systems. The overall accuracies at the genus and species level for the three systems were: API 20A, 68.9 and 56.8%, respectively; AN-IDENT, 90.2 and 73.5%; and RapID ANA, 93.9 and 81.8%. Improved identification of anaerobes with the AN-IDENT and the RapID ANA systems was observed for isolates of the genus Fusobacterium, Clostridium species other than Clostridium perfringens, non-spore-forming bacilli, and isolates of the genus Peptostreptococcus. Reproducibility studies demonstrated that the results of the individual test reactions in all three identification systems were reproducible when the interpretive guidelines of the manufacturer were followed precisely.
    背景与目标: :将两个新的用于厌氧菌的4小时识别系统AN-IDENT(纽约州普莱恩维尤市的Analytab Products)和RapID ANA(乔治亚州亚特兰大的创新诊断系统公司)的准确性进行了比较20A系统(Analytab产品)。在这三个系统中的每个系统中,共测试了132个临床分离株。这三个系统在属和种水平上的总体准确度分别为:API 20A,68.9和56.8%; AN-IDENT,分别为90.2和73.5%;和RapID ANA,分别为93.9和81.8%。观察到了用AN-IDENT和RapID ANA系统对厌氧菌的鉴定得到了改进,这些菌株包括梭菌属,产气荚膜梭菌以外的梭状芽孢杆菌,非孢子形成杆菌和拟肽链球菌属的分离株。再现性研究表明,如果严格遵循制造商的解释性指导原则,则在所有三个识别系统中单个测试反应的结果都是可再现的。
  • 【鉴定啤酒酵母中的冷冻耐受中的伴侣。】 复制标题 收藏 收藏
    DOI:10.1007/s12275-012-2411-z 复制DOI
    作者列表:Naicker MC,Seul Jo I,Im H
    BACKGROUND & AIMS: :Exposure to low temperatures reduces protein folding rates and induces the cold denaturation of proteins. Considering the roles played by chaperones in facilitating protein folding and preventing protein aggregation, chaperones must exist that confer tolerance to cold stress. Here, yeast strains lacking individual chaperones were screened for reduced freezing tolerance. In total, 19 of 82 chaperone-deleted strains tested were more sensitive to freeze-thaw treatment than wild-type cells. The reintroduction of the respective chaperone genes into the deletion mutants recovered the freeze tolerance. The freeze sensitivity of the chaperone-knockout strains was also retained in the presence of 20% glycerol.
    背景与目标: :暴露于低温下会降低蛋白质的折叠速率,并引起蛋白质的冷变性。考虑到伴侣在促进蛋白质折叠和防止蛋白质聚集中所起的作用,必须存在赋予对冷胁迫的耐受性的伴侣。在此,筛选了缺乏单个伴侣的酵母菌株以降低冷冻耐受性。总共测试了82个缺失伴侣的菌株中的19个对冻融处理的敏感性比野生型细胞高。将各自的伴侣基因重新引入缺失突变体中恢复了冷冻耐受性。在存在20%甘油的情况下,伴侣伴侣敲除菌株的冷冻敏感性也得以保持。
  • 【日语中β地中海贫血的分子异质性:两个新突变的鉴定。】 复制标题 收藏 收藏
    DOI:10.1111/j.1365-2141.1990.tb02545.x 复制DOI
    作者列表:Fucharoen S,Katsube T,Fucharoen G,Sawada H,Oishi H,Katsuno M,Nishimura J,Motomura S,Miura Y,Fukumaki Y
    BACKGROUND & AIMS: :Five unrelated Japanese beta-thalassaemia genes, from one homozygote and four heterozygotes, have been systematically characterized using DNA polymorphism analysis, polymerase chain reaction, dot-blot hybridization and direct sequencing of amplified genomic DNA. Four different molecular defects were observed on three different beta-globin gene frameworks. One of these, the A----G mutation in the TATA box, a previously described mutation, was detected by dot-blot hybridization in one homozygote and one heterozygote with the beta-globin gene of framework 2. The second mutation is a C----T substitution at position 654 of IVS-2, the mutation commonly found in Chinese, which was associated with the framework 1 gene. Another two mutations, both associated with framework 3 genes, are novel ones; an amber mutation in codon 90 (GAG to TAG) and a frameshift (+G) insertion in codon 54, both of which cause a beta 0-thalassaemia phenotype by premature termination of the beta-globin chain synthesis.
    背景与目标: :已使用DNA多态性分析,聚合酶链反应,斑点印迹杂交和扩增基因组DNA的直接测序系统地表征了来自一个纯合子和四个杂合子的五个无关的日本β地中海贫血基因。在三个不同的β-珠蛋白基因框架上观察到四个不同的分子缺陷。其中一种,即TATA盒中的A ---- G突变(一种先前描述的突变),是通过在一个纯合子和一个杂合子中与框架2的β-珠蛋白基因进行斑点印迹杂交而检测到的。第二个突变是IVS-2 654位的C ---- T取代是中国常见的突变,与框架1基因有关。与框架3基因相关的另外两个突变是新的。密码子90中的琥珀色突变(GAG到TAG)和密码子54中的移码(G)插入,两者均会因β-珠蛋白链合成的过早终止而引起β0地中海贫血表型。
  • 【GFT投影NMR可有效鉴定核酸中的(1)H /(13)C糖自旋系统。】 复制标题 收藏 收藏
    DOI:10.1007/s10858-012-9687-5 复制DOI
    作者列表:Atreya HS,Sathyamoorthy B,Jaipuria G,Beaumont V,Varani G,Szyperski T
    BACKGROUND & AIMS: :A newly implemented G-matrix Fourier transform (GFT) (4,3)D HC(C)CH experiment is presented in conjunction with (4,3)D HCCH to efficiently identify (1)H/(13)C sugar spin systems in (13)C labeled nucleic acids. This experiment enables rapid collection of highly resolved relay 4D HC(C)CH spectral information, that is, shift correlations of (13)C-(1)H groups separated by two carbon bonds. For RNA, (4,3)D HC(C)CH takes advantage of the comparably favorable 1'- and 3'-CH signal dispersion for complete spin system identification including 5'-CH. The (4,3)D HC(C)CH/HCCH based strategy is exemplified for the 30-nucleotide 3'-untranslated region of the pre-mRNA of human U1A protein.
    背景与目标: :结合(4,3)D HCCH提出了新实施的G-矩阵傅里叶变换(GFT)(4,3)D HC(C)CH实验,以有效识别(1)H /(13)C糖自旋(13)C标记核酸中的系统。该实验能够快速收集高度解析的中继4D HC(C)CH光谱信息,即由两个碳键分隔的(13)C-(1)H基团的位移相关性。对于RNA,(4,3)D HC(C)CH利用相对有利的1'-和3'-CH信号分散度来完全识别包括5'-CH的自旋系统。基于(4,3)D HC(C)CH / HCCH的策略以人U1A蛋白前mRNA的30个核苷酸的3'非翻译区为例。
  • 【新型香草类受体1拮抗剂:3.鉴定具有改善的理化和药代动力学特性的第二代临床候选药物。】 复制标题 收藏 收藏
    DOI:10.1021/jm070191h 复制DOI
    作者列表:Wang HL,Katon J,Balan C,Bannon AW,Bernard C,Doherty EM,Dominguez C,Gavva NR,Gore V,Ma V,Nishimura N,Surapaneni S,Tang P,Tamir R,Thiel O,Treanor JJ,Norman MH
    BACKGROUND & AIMS: :Based on the previously reported clinical candidate, AMG 517 (compound 1), a series of related piperazinylpyrimidine analogues were synthesized and evaluated as antagonists of the vanilloid 1 receptor (VR1 or TRPV1). Optimization of in vitro potency and physicochemical and pharmacokinetic properties led to the discovery of (R)-N-(4-(6-(4-(1-(4-fluorophenyl)ethyl)piperazin-1-yl)pyrimidin-4-yloxy)benzo[d]thiazol-2-yl)acetamide (16p), a potent TRPV1 antagonist [rTRPV1(CAP) IC50 = 3.7 nM] with excellent aqueous solubility (>or=200 microg/mL in 0.01 N HCl) and a reduced half-life (rat t1/2 = 3.8 h, dog t1/2 = 2.7 h, monkey t1/2 = 3.2 h) as compared to AMG 517. In addition, compound 16p was shown to be efficacious at blocking a TRPV1-mediated physiological response in vivo (ED50 = 1.9 mg/kg, p.o. in the capsaicin-induced flinch model in rats) and was also effective at reducing thermal hyperalgesia induced by complete Freund's adjuvant in rats (MED = 1 mg/kg, p.o). Based on its improved overall profile, compound 16p (AMG 628) was selected as a second-generation candidate for further evaluation in human clinical trials as a potential new treatment for chronic pain.
    背景与目标: :基于先前报道的临床候选药物AMG 517(化合物1),合成了一系列相关的哌嗪基嘧啶类似物,并将其评估为香草素1受体(VR1或TRPV1)的拮抗剂。体外效能,理化和药代动力学特性的优化导致发现(R)-N-(4-(6-(4-(4-(1-(4-(1-(4-氟苯基)乙基))哌嗪-1-基)嘧啶-4-烷氧基)苯并[d]噻唑-2-基)乙酰胺(16p),有效的TRPV1拮抗剂[rTRPV1(CAP)IC50 = 3.7 nM],具有优异的水溶性(在0.01 N HCl中≥200 microg / mL)和与AMG 517相比,降低了半衰期(大鼠t1 / 2 = 3.8小时,狗t1 / 2 = 2.7小时,猴子t1 / 2 = 3.2小时)。此外,化合物16p在阻断TRPV1-介导的体内生理反应(ED50 = 1.9 mg / kg,在辣椒素诱导的雀斑模型中的大鼠口服),并且在减轻大鼠完全弗氏佐剂诱导的热痛觉过敏中也有效(MED = 1 mg / kg,口服)。基于其改善的总体特性,化合物16p(AMG 628)被选为第二代候选药物,可在人类临床试验中进一步评估,作为潜在的治疗慢性疼痛的新方法。

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