975 resultados para 6-46
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患儿男,10岁,因"双侧隐睾"就诊.患儿系足月、顺产、5岁时发现头颅大,经医院诊断为脑积水.几岁时做双侧隐睾手术.患儿身高120 cm.头颅发育不规则,颜面不对称,自小严重的智力低下,说话不清.
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New approaches of making single chain Fv antibodies against O-6-methyl-2'-deoxyguanosine (O(6)MdG) have been demonstrated by using the phage antibody display system. Using O(6)MdG as an antigen, 21 positive clones were identified by ELISA from this library, one of which, designated H3, specifically binds to O(6)MdG with high affinity. The H3 scFv antibody has an affinity constant (K-aff) of 5.94 x 10(11)(mol/L)(-1). H3 scFv has been successfully used to detect O-6 MdG in DNA hydrolyses from yeast or E. coli cells treated with a DNA methylating agent. To our knowledge, this is the first report of the selection of a specific scFv against DNA adducts. The results demonstrate the potential applications of the phage display technology for the detection of DNA lesions caused by mutagens and carcinogens.
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本论文对12个N-(取代苯磺酰)吲哚类化合物体外抗HIV活性进行了初步筛选,并选择其中活性最好的化合物N-(间硝基苯磺酰)-6-甲基吲哚,对其抗HIV 活性及作用机制进行深入研究。一、体外检测了12个N-(取代苯磺酰)吲哚类化合物对C8166和MT-4细胞的毒性、对HIV-1IIIB 感染C8166后诱导的合胞体形成的抑制及对HIV-1IIIB感染MT-4 细胞后的保护作用。结果发现多个化合物具有抑制HIV-1复制活性,特别是化合物N-(间硝基苯磺酰)-6-甲基吲哚,其对HIV-1IIIB诱导的合胞体形成的EC50和TI (Therapy index)值分别为0.26 μg/ml和543.78;对HIV-1IIIB急性感染的MT-4细胞也有很好的保护作用(TI值为104.23)。二、选择活性最强的化合物N-(间硝基苯磺酰)-6-甲基吲哚进行深入的抗 HIV活性研究。在细胞水平上,通过观察致感染细胞病变和HIV-1 p24抗原表达抑制实验(ELISA方法),采用3类多株HIV病毒株(实验株、临床分离株、耐药株)和3类多种细胞(人T淋巴细胞传代株、HIV-1慢性感染人T淋巴细胞株、人外周血单个核细胞)对化合物进行体外抗HIV活性进行系统评价,实验结果表明,化合物对不同来源的HIV-1病毒株都显示出很好抗HIV活性。同时,我们也研究了化合物抗HIV-2活性,发现该化合物并不能抑制HIV-2在C8166细胞中复制。三、在细胞毒性实验上,我们检测了N-(间硝基苯磺酰)-6-甲基吲哚对不同的细胞系和人外周血单个核细胞(PBMC)毒性作用,结果显示化合物的细胞毒性较低。四、在作用机制和靶点研究上,检测了化合物对感染与未感染细胞之间融合的抑制、对HIV-1急性感染C8166细胞及对HIV-1慢性感染H9细胞(H9/HIV-1IIIB)中病毒复制的阻断作用。结果显示,N-(间硝基苯磺酰)-6-甲基吲哚对急性感染细胞有很好抑制作用(EC50为0.52 μg/ml);但对感染与未感染细胞的融合(EC50为 46.40 μg/ml)和慢性感染H9细胞中病毒的复制没有抑制作用(EC50大于100 μg/ml)。提示化合物作用于HIV侵入细胞后到HIV DNA整合前这一阶段。其后对HIV-1逆转录酶活性的抑制情况进行了分析,发现N-(间硝基苯磺酰) -6-甲基吲哚对HIV-1逆转录酶(RT)有很好抑制作用。五、构效关系分析。我们对12 个N-(取代苯磺酰)吲哚类化合物进行了初步的构效关系研究,发现在N-benzenesulfonyl 环上连接一个吸电子基团(nitro group)比供电子基团(methyl group)有更强的抗HIV 活性,但当在indoles 环上连接吸电子基团(nitro group),抗HIV 活性反而受到抑制。以上实验数据显示N-(间硝基苯磺酰)-6-甲基吲哚是一个安全有效的抗 HIV-1 候选化合物,具有进一步研究价值。
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目的研究12C6+重离子全身照射对小鼠肝组织中脂类过氧化和血清抗氧化活力的影响。方法采用硫代巴比妥酸法测定重离子6Gy辐照后各组肝组织中脂质过氧化值;采用电子自旋共振自旋捕集技术检测辐照后各组血清对羟基的清除率。结果12C6+重离子全身辐照后46、70、82h组肝组织中脂质过氧化值明显增加,与对照组相比差异有显著性(P<0.01),但未出现峰值;辐照后各组血清对羟基的清除率明显下降,其中82h组的清除率最低,辐照后各组与对照组相比差异有显著性(P<0.01)。结论12C6+重离子全身辐照能引起小鼠肝组织中脂类过氧化并能使血清抗氧化活力下降。
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Nd-129 was produced by irradiation of an enriched target of Ru-96 with a Ar-36 beam and studied by using a helium-jet fast tape transport system in combination with X-gamma and gamma-gamma coincidence measurements. A 2.6s isomer of Nd-129 was observed for the first time and tentatively proposed to be the configuration of 1/2[411].
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A facile and efficient one-pot synthesis of substituted cyclophosphamidic chlorides and their analogues has been developed from readily available enaminones, 2-arylamino-3-acetyl-5,6-dihydro4H-pyrans.
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中华绒螯蟹是我国重要的水产经济动物,近年来养殖规模不断扩大,产量持续增加。但是,伴随着养殖规模的扩大,养殖环境也日益恶化并导致了大量疾病的发生,严重制约了中华绒螯蟹养殖业的健康发展。因此,疾病预防和控制对中华绒螯蟹养殖业的可持续发展具有举足轻重的作用。与其他无脊椎动物一样,中华绒螯蟹的免疫系统没有免疫球蛋白和淋巴细胞,而是依靠由细胞免疫和体液免疫构成的固有免疫系统来对病原进行识别和清除。中华绒螯蟹的固有免疫机制的研究有助于推动中华绒螯蟹病害防治工作的开展。 本研究采用大规模EST测序方法,结合末端快速扩增(rapid amplification of cDNA ends,RACE)技术从中华绒螯蟹血淋巴中克隆到了过氧化物还原酶(peroxiredoxin,EsPrx6)和硫氧还蛋白(thioredoxin,EsTrx1)基因的cDNA 全长序列;采用实时荧光定量PCR 技术检测了这两个基因在健康个体中表达的组织分布情况以及鳗弧菌刺激后血淋巴细胞中的时序表达规律;同时,将这两个基因的编码区克隆到pET 系列载体,并在大肠杆菌中实现了重组表达,并进行了体外活性检测。 过氧化物还原酶是一个抗氧化蛋白超家族,在保护机体免受活性氧(reactive oxygen species,ROS)的伤害中发挥着重要作用。中华绒螯蟹Prx6(EsPrx6) 基因的cDNA 全长为1076 bp,5` UTR(untranslated region,UTR) 为69 bp,3` UTR 为347 bp,开放阅读框(open reading frame,ORF)为660 bp,编码219 个氨基酸的蛋白。mRNA 3`-端具有多聚腺苷酸加尾信号(polyadenylation signal)AATAAA 和polyA 尾巴。EsPrx6 的预测分子量为 24 kDa,理论等电点为6.21,具有一个保守的Prx 结构域、一个AhpC 结构域和过氧化物酶催化活性中心PVCTTE,表明EsPrx6 属于1-Cys 型Prx。在所检测的组织中均有EsPrx6 的表达,其中以肝胰腺表达量最高,为血淋巴细胞中表达量的17.4 倍。鳗弧菌刺激后,血淋巴细胞中EsPrx6 的表达下降,到12 h 时,实验组显著低于对照组(P<0.05);随时间推移,表达水平逐渐回升,但在整个实验期间,都没有恢复到起始水平。将EsPrx6 进行体外重组并在大肠杆菌E. coli BL21(DE3)中实现表达,重组EsPrx6 具有预期的抗氧化活性和过氧化物酶活性,其中抗氧化活力为14.69 U/mg 蛋白,高于相同条件下GSH 的抗氧化力(P<0.05),过氧化物酶活力为23.46 U/mg 蛋白。结果表明,EsPrx6 作为一种重要的抗氧化剂,在中华绒螯蟹抵御ROS 可能引起的氧化损伤方面具有重要作用。 硫氧还蛋白是广泛存在于生物体内的一种具有硫醇依赖性的具有还原活性的蛋白。中华绒螯蟹Trx1(EsTrx1)基因的cDNA 全长为641 bp,5` UTR 为17 bp,3` UTR 为306 bp,开放阅读框为318 bp,编码105 个氨基酸。EsTrx1 的预测分子量为12.2 kDa,理论等电点为4.8。EsTrx1 不含信号肽,其氨基酸序列与其他动物的Trx1s 具有高度相似性,如与地中海黄蝎的Trx1 相似度达到73%;而与其他物种Trx2 的同源性很低,相似度仅为14.3-22.8%,表明EsTrx1 属于Trx1 亚族。实时荧光定量PCR 检测发现,EsTrx1 在鳃、性腺、肝胰腺、肌肉、心脏和血淋巴细胞中都有表达。血淋巴细胞中EsTrx1 mRNA 的表达量在菌刺激后上升,刺激后6 h,实验组表达量显著高于对照组和空白组(P<0.05),然后逐渐恢复到刺激前水平。为进一步探讨其生物学功能,将EsTrx1 进行体外重组并在大肠杆菌E. coli BL21(DE3)得到表达,重组EsTrx1 具有预期的氧化还原调节活性,抗氧化活力为3.06 U/mg,且抗氧化活力高于GSH(P<0.05)。rEsTrx1 的二硫键还原活力为5.03,低于凡纳滨对虾的二硫键还原活力(10.44),接近于大肠杆菌(4.93),小牛胸腺(6.50)和小牛肝脏(5.09),而高于鲍鱼Trx2(1.83)活力。结果表明,EsTrx1 在生理条件下能够作为一种重要的抗氧化剂,参与对细菌感染的免疫应答反应。
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Tony Mann provides a review of the lecture: 'Three great mathematicians: Euler' held on 6 March 2002 as the fourth and last lecture of the Gresham College History of Mathematics season.
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Infant sleep undergoes significant re-organization throughout the first 12 months of life, with sleep quality having significant consequences for infant learning and cognitive development. While there has been great interest in the neural basis and developmental trajectories of infant sleep in general, relatively little is known about individual differences in infant sleep and the socio-economic and cultural sources of that variability. We investigated this using questionnaire sleep data in a large, unique multi-ethnic sample of 6-7 month-olds (n=174), with families from South Asian ethnic groups in the UK (Indian, Pakistani and Bangladeshi) being especially well represented. Consistent with previous data from less variable samples, no effects of SES on sleep latency or nocturnal sleep duration emerged. However, perinatal risk factors and ethnic differences did predict daytime sleep, sleep fragmentation and sleep-onset time. While these results should be interpreted with caution due to several limitations, they likely demonstrate that even when socio-economic status and ethnicity are much less confounded than in previous studies, they have a surprisingly limited impact on individual differences in sleep patterns in young infants.
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Multiclass analysis method was optimized in order to analyze pesticides traces by gas chromatography with ion-trap and tandem mass spectrometry (GC-MS/MS). The influence of some analytical parameters on pesticide signal response was explored. Five ion trap mass spectrometry (IT-MS) operating parameters, including isolation time (IT), excitation voltage (EV), excitation time (ET),maximum excitation energy or “q” value (q), and isolationmass window (IMW) were numerically tested in order to maximize the instrument analytical signal response. For this, multiple linear regression was used in data analysis to evaluate the influence of the five parameters on the analytical response in the ion trap mass spectrometer and to predict its response. The assessment of the five parameters based on the regression equations substantially increased the sensitivity of IT-MS/MS in the MS/MS mode. The results obtained show that for most of the pesticides, these parameters have a strong influence on both signal response and detection limit.Using the optimized method, a multiclass pesticide analysis was performed for 46 pesticides in a strawberry matrix. Levels higher than the limit established for strawberries by the European Union were found in some samples.
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[Acte. 1767-04-03. Versailles]