Natural killer cells and malaria

Summary:  Malaria, caused by the infection with parasites of the germs Plasmodium , is one of the three most important infectious diseases worldwide, along with tuberculosis and infection with human immunodeficiency virus. Natural killer (NK) cells are lymphocytes classically involved in the early defense against viral infections and intracytoplasmic bacterial infections and are also implicated during the course of tumor development and allogeneic transplantation. These cells display important cytotoxic activity and produce high levels of proinflammatory cytokines. In both mouse and human models of malaria, NK cells appear to be a major source of interferon-γ during the early phase of infection. In humans, indirect signaling through monocytes/macrophages required to optimally stimulate NK cell activity. However, the in vivo functions of NK cells during malaria are still enigmatic, and many issues remain to be dissected, such as the molecular basis of the direct recognition of iRBCs by NK cells.     

Detection of DNA from infectious laryngotracheitis virus by colourimetric analyses of polymerase chain reactions

A combination of the polymerase chain reaction and a novel ELISA-type DNA colourimetric assay (developed from studies with a retrovirus from man) was used in a preliminary study to detect DNA from avian infectious laryngotracheitis virus. The method is sensitive, specific and easy to perform. Since it can be readily adapted for the detection of DNA from other sources it could be useful for the identification of a variety of pathogens from other species of veterinary importance.     

Rb基因在鼻咽癌中存在状态的研究

首次应用生物素－１４－ｄＵＴＰ标记Ｒｂ３．８ｋｂ探针，结合亲合素－碱性磷酸酶发光及自显影法，对Ｒｂ基因在鼻咽癌中存在状态进行了研究。杂交结果表明，３例正常胎儿鼻咽组织出现分子量为１２．８、１０．２、８．０、６．２、５．６、５．２及４．８ｋｂ的７条杂文区带，１１例鼻咽癌组织均发现有Ｒｂ基因缺失或失活，其中４例为５．６ｋｂ片段缺失，４例为４．８ｋｂ缺失并有２例伴５．６ｋｂ减弱，２例为１０．２ｋｂ缺失，１例为５．６及５．２ｋｂ片段显著减弱，说明在上述１１例鼻咽癌中均有Ｒｂ基因的改变。这种高频率的异常变化，提示Ｒｂ基因的缺失或失活，与鼻咽癌的发生有密切关系。     

“Smart” Materials for Biosensing Devices: Cell-Mimicking Supramolecular Assemblies and Colorimetric Detection of Pathogenic Agents

Mimicking cell membrane and the biomolecular recognition associated with membranes represents a great technical challenge, yet it has opened doors to innovative diagnostic and therapeutic methods. Our work has focused on design and synthesis of a class of smart materials exploiting biological principals for use in biosensors: these materials are functional polymeric assemblies that mimic the cell membrane and conveniently report the presence of pathogens with a color change. Biologically active cell membrane components are incorporated into conjugated polymers with desirable optical properties and the binding of the target molecules onto the material triggers conformational and electronic shifts that are reflected in a chromatic change (a so-called biochromic shift) that is conveniently observed and recorded. Langmuir–Blodgett thin films and vesicle bilayers provide ideal configurations for precise delivery of the biological binding entity to the sensing interface, and for control of molecular orientation for effective biomolecular interaction. Polydiacetylenic membrane-mimicking materials containing cell surface receptor gangliosides and sialic acid residues, respectively were formulated into these architectures and used for colorimetric detection of bacterial toxins and influenza virus. One advantage of these biochromic conjugated polymer (BCP) sensors is that their molecular recognition and signal transduction functionalities are resident in a single functional unit, making them amenable to convenient microfabrication and use.     

马凡综合征微纤维蛋白1基因突变检测及单倍型连锁分析

目的：检测中国人马凡综合征（Marfan syndrome,MFS)患者微纤维蛋白1（fibillin-1,FBN1)基因的突变及对马凡综合征患者的家系成员进行症状前诊断。方法：应用聚合酶链反应－单链构象多态性技术和测序方法，对汉族9个家系中共17个MFS患者进行基因突变检测；运用FBN1基因内4个内含子中的可变串联重复序列构建染色体单倍型，进行家系单倍型连锁分析和基因诊断。结果：发现MFS（A）家系Ⅱ1患者有单链构象改变，测序证实为位于FBN1基因第25号外显子3243－3256核苷酸之间有I个13bp的小片段缺失，为新位点基因移码突变，其序列为gcctctgcaccca;单倍型连锁分析发现MFS（B）家系Ⅲ1是1个无症状期患者。结论：中国人FBN1基因突变可以引起马凡综合征，应用突变检测与单倍型连锁分析方法能为马凡综合征基因诊断提供依据。     

Detection of Mycoplasma hominis antigen in clinical specimens by using a four-layer modification of enzyme immunoassay (EIA)

A 4-layer modification of enzyme immunoassay (EIA) was developed for the detection of Mycoplasma hominis antigen in clinical specimens. Microtiter plates were sensitized with rabbit anti-mycoplasma immunoglobulin, guinea pig anti-mycoplasma immunoglobulin was used as the secondary antibody, and horseradish peroxidase-conjugated anti-guinea pig immunoglobulin was used as the indicator antibody. The specificity of the assay was confirmed by using guinea pig immunoglobulins from preimmunization sera. The sensitivity of the assay is down to 10 ng/ml of antigen protein. Marked cross-reactivity was demonstrated for different strains within the species M. hominis, whereas the other genital mycoplasma species tested showed no reactivity in the assay. A comparison was made of EIA and conventional culture of vaginal specimens from 24 women. All 6 specimens positive by culture were also positive for M. hominis antigen by EIA. Antigen detection by EIA is a sensitive, rapid and simple method for the detection of M. hominis in clinical specimens.     

GKT原理的模拟犯罪测试范式实验研究

目的:本实验旨在以实际犯罪较接近的实验场景验证GKT的测谎机制,并探讨其对罪犯以及其他嫌疑人的判定有效性。方法:以72名健康大学生为被试,让被试在模拟犯罪的背景下采用三种包含不同说谎和认知成分的回答方式进行测谎测试,采用Limestone测谎仪测量被试皮肤电反应。结果:回答方式与角色两因子在判定分数上的主效应均显著,交互作用不显著。结论:在模拟犯罪测试范式下,GKT模式中认知与说谎机制是共存的,其中认知成分不占主要地位,说谎成分占主要地位,GKT模式无法兼顾有效地判定"犯罪"和"知情无辜"角色,需进一步改进。     

Patient and parental attitudes toward genetic screening and its implications at an adult cystic fibrosis centre

General population screening for cystic fibrosis carrier status in the United Kingdom would detect 72% of at-risk couples. Proper counselling would allow these couples to make informed reproductive choices, including the possibility of prenatal diagnosis and the termination of an affected pregnancy. However, children with cystic fibrosis born in this decade, given optimum treatment, now have an average life expectancy of 40 years, and there is no unanimity of opinion on how, where, when, or even if, screening should be offered. The purpose of this questionnaire-based study was to examine the attitudes of an adult clinic population who have grown up with cystic fibrosis, and of their parents, towards genetic screening programmes and the controversies and ethical dilemmas surrounding such programmes in cystic fibrosis. Both patients and parents supported prenatal screening (88% and 90%) and the option of terminating an affected pregnancy (68% and 84%). Only 22% of patients and 10% of parents felt that screening should be limited to families with a history of cystic fibrosis, and 19% and 6%, respectively, that prenatal diagnosis should be restricted to those with a previous child with cystic fibrosis. Despite the negative aspects of any screening programme and the acknowledged ethical problems peculiar to cystic fibrosis, the conclusion of our patients and parents who have lived intimately with the illness is that there should be the option of utilising information available from genetic screening for cystic fibrosis to guide reproductive choices. Pilot programmes to define the optimum management of such screening should continue.     

ST2作为Th2细胞亚群标志以及其与支气管哮喘的关系的研究

各自主要分泌IFN γ和IL 4的Th1和Th2亚群 ,与临床疾病的关系十分密切。如何从表面标志上加以区分是一项迫切需要解决的问题。ST2是近年来提出的Th2细胞的稳定标志物。本工作在体外成功地诱导人脐带血T细胞向Th1或Th2分化的基础上 ,应用逆转录PCR分析了ST2mRNA的表达特点。证实ST2在人Th2细胞上的选择性表达。为了探索ST2、Th2与支气管哮喘的关系 ,本工作进一步检测了正常人和支气管哮喘患者外周血单个核细胞中 β actin、ST2以及IFN γ和IL 4的mRNA水平。结果显示 :支气管哮喘患者ST2mRNA水平升高 ,IL 4水平也明显升高 ,但IFN γ无变化。这提示ST2作为Th2细胞的标志物 ,有可能成为Th2极化性疾病如哮喘发病机制研究的一个参考性标志 ,至于ST2是否有可能作为治疗的靶分子 ,有待进一步探讨     

Detection of single nucleotide substitution by competitive allele-specific short oligonucleotide hybridization (CASSOH) with immunochromatographic strip

Recent advances in human genome research have revealed that genetic polymorphisms, such as single nucleotide polymorphisms (SNPs), are closely associated with susceptibility to various common diseases and adverse drug reactions. Also, numerous mutations responsible for a number of genetic diseases have been identified. Clinical application of genetic information to individual health care requires simple and rapid identification of nucleotide changes in clinical settings. We have devised a novel low-tech method for the detection of a single nucleotide substitution using competitive allele-specific short oligonucleotide hybridization with immunochromatographic strip. The gene of interest is PCR-amplified, hybridized to an allele-specific short oligonucleotide probe in the presence of a competitive oligonucleotide, and subjected to chromatography using a DNA test strip at room temperature. The genotype is unambiguously determined by the presence or the absence of visible purple lines on a strip. Feasibility of the method was demonstrated by the detection of a prevalent disease-causing mutations in glycogen storage disease type Ia (G6PC), medium-chain acyl-CoA dehydrogenase deficiency (ACADM), non-ketotic hyperglycinemia (GLDC), and clinically important polymorphisms in the CYP2C19 gene and the aldehyde dehydrogenase 2 gene (ALDH2). The procedure does not demand either technical expertise or expensive instruments and is readily performed in local clinical laboratories. The result is obtained within 10 min after PCR. This rapid and simple method of SNP detection may be used for point-of-care genetic diagnosis with potentially diverse clinical applications. Hum Mutat 22:166-172, 2003.