在HBsAg阳性母亲流产的胎儿肝细胞基因组中检出整合型HBV DNA顺序

从9例HBsAg(RPHA法)和HBeAg(ID法)均阳性母亲流产的9例胎儿肝组织抽提高分子量肝细胞DNA,与~(32)P标记的克隆HBV DNA探针进行Southern blot杂交试验,以检测胎肝细胞中HBV DNA的存在状态,并与胎儿的血清学、免疫电镜及免疫组织化学的检测结果相比较。经EcoRI酶切的9例胎肝细胞DNA与放射性标记的探针杂交后,F27胎肝DNA样品在9.0kb和5.2kb处各有一条杂交带,F31胎肝DNA样品在8.2kb、6.6kb及4.8kb处有杂交带,而F32胎肝DNA样品出现的两条杂交带则分別在6.6kb及5.4kb处(图略),     

基因芯片技术及其数据处理方法

基因芯片又称DNA微阵列,该技术将大量的核苷酸探针以点阵列的方式排布于固相支持物上,与荧光标记的DNA样品杂交,通过激光共聚焦等方法对样品DNA进行定量检测。基因芯片技术具有自动化,高通量的特点,是基因表达谱研究的一种重要手段,在农业,医学,药物学等方面也有着广阔的应用前景。如何对基因芯片实验中所产生的大量数据进行有效的生物学分析,已成为芯片研究中的一个热点。基因芯片数据分析的流程通常包括了表达谱数据的获取与标准化,差异表达基因的筛选,基因的功能性分类及生物学意义的分析。     

两种PCR增强剂对A27 Plex试剂盒和EX22 AGCU试剂盒的影响

目的采用直接提取的方法对1例女性全血样本进行PCR扩增,比较BSA(牛血清白蛋白,Albumin from bovine serum)和DMSO(二甲基亚砜,Dimethyl sulfoxide)两种PCR增强剂对A27 Plex试剂盒和EX22 AGCU试剂盒PCR扩增效率的影响。方法在A27 Plex试剂盒和EX22 AGCU试剂盒中加入不同体积的BSA和DMSO后对全血样本进行PCR扩增以及STR分型。结果经数据统计和T检验方法,得出AGCU Ex22试剂盒中加入BSA对全血样本PCR扩增起到抑制作用,而加入DMSO对全血样本PCR扩增起到一定程度促进作用;A27 plex试剂盒中加入BSA对全血样本PCR扩增起到促进作用结论在不改变加入试剂总体系,仅改变加入dd H2O体积的情况下,加入1μL BSA可以有效抑制血红素对PCR扩增左右的影响,加入0.2μL DMSO可有效减弱模板DNA局部二级结构对PCR扩增的抑制作用。     

生物芯片技术——我省医药生物技术走向世界的突破口

<正> 生物芯片技术创建于二十世纪九十年代,1994年,美国斯坦辐大学M·Schena提出了设想并进行了大量试验。1996年底,美国加州旧金山Affymatrix公司Steven Fodor等充分结合并灵活运用照相平板印刷、计算机、半导体、激光共聚焦扫描、寡核苷酸、DNA合成荧光标记、探针杂交分子生物学的其他技术,创造了世界上第一块DNA芯片或DNA阵列(DNA chip or DNA arrays)即基因芯片(生物芯片的一种类)。     

汞害无所不在

汞是一种对神经系统有毒性的物质，汞对发育中的胎儿的危害尤其令人担忧。一项全国性调查表明，相当一部分育龄妇女的体内组织含汞过高。位于阿什维尔的北卡罗莱纳州大学的研究者是通过对近1500名各种年龄的被调查者的头发样本进行分析获得这些研究结果的。在其生长过程中，     

D6S1043基因座检出三带型等位基因2例及遗传分析

目的:在亲子鉴定案件中检出D6S1043基因座三带型。方法:提取个体不同组织DNA样本,经复合荧光PCR扩增和毛细管电泳分析2716个案例(共6246名个体)的STR分型。结果:在1个父子单亲鉴定案例中,2名个体的D6S1043基因座上出现三带型等位基因。用Power Plex?21荧光标记复合扩增试剂盒对包含D6S1043在内的21个STR基因座进行检测,父亲D6S1043基因座分型为17/18/21,儿子分型为10/17/18,电泳峰高和峰面积之比均为1∶1∶1,用SinofilerTM试剂盒复核检测结果相同。结论:在本文发现的案例中,父亲的等位基因17和18均遗传给了儿子,导致儿子表现为三带型等位基因。D6S1043三带型非常罕见,在分析时应采用不同方法或者试剂盒进行验证,保证鉴定结果的可靠性。     

健康离不开芯片

在SARS基因组序列公布不到一周的时间里,全球最大的基因芯片提供商(Affymetrix)就开发出了这种致命的病毒基因芯片。该公司宣布,SARS基因芯片利用加拿大、美国和亚洲所公布的SARS病毒基因组序列,包含了所有29700个碱基。利用这一基因芯片可以帮助科学家区别这种病毒的不同株系,检测其流行动态等。这组基因芯片不仅将在SARS流行病学研究和诊断中起到重要作用,还可以将病人的预后与病毒的基因型进行关联分析,以更好地了解哪种病毒最为危险,并可能发现涉及治疗方法的关键因子。 20世纪90年代以来,尤其是近几年,人们通常认为仅仅是电子域应用的集成电路芯片,如今越来越多的被科学家用于临床医学,直接造福于人体健康。     

基因芯片技术在致病微生物研究中的应用

高密度寡核苷酸DNA芯片技术可以通过一次杂交试验获得大量的基因组信息,在基因组结构与基因表达分析中应用最广,在与人类健康有关的遗传病、传染病等诸多疾病中具有广泛的应用前景.本文重点对基因芯片技术在细菌、病毒等致病微生物病原鉴定、分类与致病机制研究中的应用作一简要介绍.     

31例妊娠期糖尿病与多囊卵巢综合征相关分析

妊娠期糖尿病(gestational diabetes mellitus GDM)是代谢综合征的一种早期表现,多在产后恢复,但仍有33.3%的病例于产后5～10年转为糖尿病.GDM对孕妇及胎儿、新生儿可造成一些不利影响.多囊卵巢综合征(Polycystic ovary syndrome,PCOS)是生育年龄妇女常见的一种内分泌及糖代谢异常所致的病理状态,可致胰岛素抵抗(IR)形成体内高血糖.现有证据提示妊娠期糖尿病(GDM)与PCOS相关,本文通过31例GDM患者分娩后相关资料分析,以讨论二者的相关性.……     

乙型肝炎病毒子宫内传播的研究

对15例HBsAg阳性(RPHA法)母亲的16例流产死胎开胸后心脏穿刺采血,并采集胎肝组织。应用ELISA检测胎儿血清HBsAg及IgM抗HBc,并检测胎儿血清HBV DNA多聚酶活力;免疫电镜法检测胎儿血清及肝匀浆中HBV抗原颗粒;将10％中性福尔马林固定、石蜡包埋的胎肝组织应用未标记的PAP法(DAKO PAP kit)检测肝细胞的HBsAg及HBcAg。结果以免疫电镜从其中7例胎儿血清及肝匀浆中查到HBsAg抗原颗粒,其中5例血     

Single molecule analysis of bacterial polymerase chain reaction products in submicrometer fluidic channels

Laser induced fluorescence in submicrometer fluidic channels was used to characterize the synthesis of polymerase chain reaction (PCR) products from a model bacterial system in order to explore the advantages and limitations of on chip real time single molecule PCR analysis. Single oligonucleotide universal bacterial primers and PCR amplicons from the 16S rDNA of Thermobifida fusca (325 bp) were directly detected at all phases of the reaction with low sample consumption and without post-amplification purification or size screening. Primers were fluorescently labeled with single Alexa Fluor 488 or Alexa Fluor 594 fluorophores, resulting in double labeled, two color amplicons. PCR products were driven electrokinetically through a fused silica channel with a 250 nm by 500 nm rectangular cross section. Lasers with 488 nm and 568 nm wavelengths were focused and overlapped on the channel for fluorescence excitation. All molecules entering the channel were rapidly and uniformly analyzed. Photon burst analysis was used to detect and identify individual primers and amplicons, and fluorescence correlation and cross-correlation spectroscopy were used to account for analyte flow speed. Conventional gel and capillary electrophoresis were also used to characterize the PCR amplification, and the results of differences in detection sensitivity and analyte discrimination were examined. Limits were imposed by the purity and labeling efficiency of the PCR reagents, which must be improved in parallel with increases in detection sensitivity.     

Fluid dynamical analysis of the distribution of ink jet printed biomolecules in microarray substrates for genotyping applications

Oligonucleotide microarrays are tools used to analyze samples for the presence of specific DNA sequences. In the system as presented here, specific DNA sequences are first amplified by a polymerase chain reaction (PCR) during which process they are labeled with fluorophores. The amplicons are subsequently hybridized onto an oligonucleotide microarray, which in our case is a porous nylon membrane with microscopic spots. Each spot on the membrane contains oligonucleotides with a sequence complementary to part of one specific target sequence. The solution containing the amplicons flows by external agitation many times up and down through the porous substrate, thereby reducing the time delaying effect of diffusion. By excitation of the fluorophores the emitted pattern of fluorophores can be detected by a charge-coupled device camera. The recorded pattern is a characteristic of the composition of the sample. The oligonucleotide capture probes have been deposited on the substrate by using noncontact piezo ink jet printing, which is the focus of our study. The objective of this study is to understand the mechanisms that determine the distribution of the ink jet printed capture probes inside the membrane. The membrane is a porous medium: the droplets placed on the membrane penetrate in the microstructure of it. The three-dimensional (3D) distribution of the capture probes inside the membrane determines the distribution of the hybridized fluorescent PCR products inside the membrane and thus the emission of light when exposed to the light source. As the 3D distribution of the capture probes inside the membrane eventually determines the detection efficiency, this parameter can be controlled for optimization of the sensitivity of the assay. The main issues addressed here are how are the capture probes distributed inside the membrane and how does this distribution depend on the printing parameters. We will use two model systems to study the influences of different parameters: a single nozzle print head jetting large droplets at a low frequency and a multinozzle print head emitting small droplets at a high frequency. In particular, we have investigated the effects when we change from usage of the first system to the second system. Furthermore, we will go into detail how we can obtain smaller spot sizes in order to increase the spot density without having overlapping spots, leading eventually to lower manufacturing costs of microarrays. By controlling the main print parameters influencing the 3D distribution inside the porous medium, the overall batch-to-batch variations can possibly be reduced.     

A method of measuring information in language,applied to medical texts

In this study, quantitative measures of the information content of textual material have been developed based upon analysis of the linguistic structure of the sentences in the text. It has been possible to measure such properties as: (1) the amount of information contributed by a sentence to the discourse; (2) the complexity of the information within the sentence, including the overall logical structure and the contributions of local modifiers; (3) the density of information based on the ratio of the number of words in a sentence to the number of information-contributing operators.Two contrasting types of texts were used to develop the measures. The measures were then applied to contrasting sentences within one type of text. The textual material was drawn from narrative patient records and from the medical research literature. Sentences from the records were analyzed by computer and those from the literature were analyzed manually, using the same methods of analysis. The results show that quantitative measures of properties of textual information can be developed which accord with intuitively perceived differences in the informational complexity of the material.     

钢板表面缺陷深度主动学习高效分类方法

针对钢板表面缺陷图像分类传统深度学习算法中需要大量标签数据的问题,提出一种基于主动学习的高效分类方法。该方法包含一个轻量级的卷积神经网络和一个基于不确定性的主动学习样本筛选策略。神经网络采用简化的convolutional base进行特征提取,然后用全局池化层替换掉传统密集连接分类器中的隐藏层来减轻过拟合。为了更好的衡量模型对未标签图像样本所属类别的不确定性,首先将未标签图像样本传入到用标签图像样本训练好的模型,得到模型对每一个未标签样本关于标签的概率分布(probability distribution over classes, PDC),然后用此模型对标签样本进行预测并得到模型对每个标签的平均PDC。将两类分布的KL-divergence值作为不确定性指标来筛选未标签图像进行人工标注。根据在NEU-CLS开源缺陷数据集上的对比实验,该方法可以通过44%的标签数据实现97%的准确率,极大降低标注成本。     

Angiotensin Converting Enzyme Gene Polymorphism and its Association with Hypertension in South Indian Population

Hypertension, a well known risk factor for various cardiovascular, peripheral vascular and renal events is an important public health challenge. Renin angiotensin system (RAS) being the most vital pathogenic mechanism of hypertension is mediated by a key component; the angiotensin converting enzyme (ACE). The present study was aimed to know the relationship of ACE gene polymorphism and the possible risk of development of hypertension in south Indian population. The study included 101 clinically diagnosed hypertensive patients without any associated disease condition and 81 age and sex matched apparently healthy controls. Genotyping was performed using a polymerase chain reaction, (PCR) amplification of the intron 16 fragment harboring the 287 bp Alu repeat sequence. Three possible genotypes D/D, I/I homozygous and I/D heterozygous were analyzed where the D/D genotypes corresponds to higher ACE levels (D-Deletion, I-Insertion). The PCR products were separated on 2 % agarose gel. Statistical analysis was performed using SPSS.15 software program. We found a significance in frequency of D/D genotype in the hypertensive patients compared to the control group (p = 0.0005, odd’s ratio = 4.157). This suggested that ACE (D/D) genotypes are more prone for the development of hypertension. This is relatively a pilot study; but nevertheless may assist in identifying the pathophysiological cause of hypertension.     

Detection of non-deletional type of hereditary persistence of fetal hemoglobin (HPFH) condition associated with 619 bp β°-thalassemia deletion

DNA samples from a family (parents and a son) with hereditary persistence of fetal hemoglobin (HPFH) condition were subjected to amplification of a 1.214 kbp DNA fragment from β-globin gene using polymerase chain reaction (PCR). The aim of this study was to identify the type of HPFH i.e. deletional or non deletional. Non deletional type of HPFH was identified in two samples and moreover, these samples were found to be associated with 619bp β^°-thalassemia deletion. This is the first report on the association of non deletional HPFH with 619bp β^°-thalassemia deletion.     

使用免疫BMPs纯化细菌PCR反应模板的比较

目的:使用免疫BMPs,对含有大肠杆菌O157的粪便标本,进行目标病原菌的捕获和洗净,建立一种快速纯化细菌PCR反应模板的方法。方法:将大肠杆菌O157抗体接种于BMPs表面,制成免疫BMPs。使用免疫BMPs,对含有不同浓度大肠杆菌O157的粪便标本,进行目标病原菌的捕获、分离和洗净,再使用洗净的病原菌制备PCR反应模板。作为对照,对含有不同浓度大肠杆菌O157的粪便标本,常规进行增菌培养及鉴别培养后,制备细菌的PCR反应模板,或粪便标本直接制备PCR反应模板。结果:使用免疫BMPs处理后制备PCR反应模板,与通过常规增菌培养和鉴别培养后制备PCR反应模板,PCR检测结果一致。而粪便标本直接取样制备PCR反应模板,大肠杆菌O157低浓度时,PCR检测的阳性率较低。结论:利用免疫BMPs捕获自然标本(粪便)中的目标病原菌,通过分离和洗净,去除标本中存在的PCR反应抑制物等影响因素,可省略增菌培养及鉴别培养,快速纯化目标病原菌的PCR反应模板。     

One-step,codominant detection of imidazolinone resistance mutations in weedy rice (Oryza sativa L.)

BackgroundWeedy rice (Oryza sativa L.) is a noxious form of cultivated rice (O. sativa L.) associated with intensive rice production and dry seeding. A cost-efficient strategy to control this weed is the Clearfield rice production system, which combines imidazolinone herbicides with mutant imidazolinone-resistant rice varieties. However, imidazolinone resistance mutations can be introgressed in weedy rice populations by natural outcrossing, reducing the life span of the Clearfield technology. Timely and accurate detection of imidazolinone resistance mutations in weedy rice may contribute to avoiding the multiplication and dispersion of resistant weeds and to protect the Clearfield system. Thus, highly sensitive and specific methods with high throughput and low cost are needed. KBioscience’s Allele Specific PCR (KASP) is a codominant, competitive allele-specific PCR-based genotyping method. KASP enables both alleles to be detected in a single reaction in a closed-tube format. The aim of this work is to assess the suitability and validity of the KASP method for detection in weedy rice of the three imidazolinone resistance mutations reported to date in rice.ResultsValidation was carried out by determining the analytical performance of the new method and comparing it with conventional allele-specific PCR, when genotyping sets of cultivated and weedy rice samples. The conventional technique had a specificity of 0.97 and a sensibility of 0.95, whereas for the KASP method, both parameters were 1.00.ConclusionsThe new method has equal accuracy while being more informative and saving time and resources compared with conventional methods, which make it suitable for monitoring imidazolinone-resistant weedy rice in Clearfield rice fields.     

五年制医学生消化内科临床教学效果的回顾性分析

五年制医学教育中的重要组成部分就是临床教学,旨在培养综合临床思维方法及临床各专业技能。文章通过回顾性调查五年制医学院校近5年内毕业的本科生所具备的消化内科临床技能和理论知识,及对当年教学方法的评价,探讨影响消化内科教学效果的主要因素。结果提示:(1)对照组问卷基本理论知识与临床技能得分及毕业时成绩均低于观察组,差异有统计学意义;(2)观察组学生在培养临床思维能力、提高学习兴趣、提高交流能力、病历书写能力等方面的认同度均明显优于对照组学生,差异有统计学意义(P0.05)。