一种从外周血单个核细胞中祛除低密度粒细胞并纯化T淋巴细胞的简易方法（英文）

目的:系统性红斑狼疮(SLE)患者外周血单个核细胞(PBMCs)中的低密度粒细胞(LDGs)可以自发而过度地形成中性粒细胞胞外网状陷阱(NETs),而形成的NETs会降低T细胞激活的阈值。采用PBMCs做淋巴细胞研究时,所含的异常增多的LDGs可能会显著影响实验结果。因此需要了解其他自身免疫病中LDGs的比例,并需要一种简便地祛除PBMCs中LDGs的方法。创新点:首次提出LDGs清除的方法,验证了离心后贴壁法清除LDGs的有效性和可靠性。方法:采用流式细胞仪测定55例皮肌炎(DM)患者、15例多发性肌炎(PM)患者、42例类风湿关节炎(RA)患者、25例SLE患者(阳性对照)和19例健康对照(阴性对照)PBMCs中LDGs的比例。采用提高离心力、离心后贴壁和全血沉淀后再离心这三种方法祛除PBMCs中的LDGs,进一步比较各种方法的LDGs清除率和对PBMCs中T细胞的影响程度。清除T-SPOT.TB阳性患者PBMCs中LDGs后复测T-SPOT.TB,明确LDGs是否对T-SPOT.TB结果有影响。结论:本研究中DM、PM、RA和SLE患者PBMCs中LDGs比例普遍升高(图1)。清除PBMCs中LDGs后,T-SPOT.TB显著降低(图2)。离心后贴壁法不但能最有效地清除LDGs,且对PBMCs中T细胞的比例影响最小(图3~5)。综上所述,PBMCs中LDGs的比例在DM、PM、RA和SLE患者中普遍增高;采用PBMCs做T细胞相关研究时LDGs通过形成NETs对T细胞激活的影响不能忽视;离心后贴壁法可以简单而高效地清除PBMCs中的LDGs。     

CCR5稳定表达的CHO细胞的构建

在人体内,CCR5与许多免疫疾病有关,CCR5有望成为众多药物的作用靶点。将ccr5基因与真核表达载体pBBS242构建成重组质粒pBBS242-ccr5,转染CHO细胞,并经潮霉素B筛选。流式细胞仪检测结果表明CCR5在CHO细胞得到了稳定表达。     

牛乳酪蛋白源ACE抑制肽的稳定性和毒理特性研究(英文)

研究目的:酸碱热处理对牛乳酪蛋白源血管紧张素转化酶(ACE)抑制肽的抑制活性、游离氨基、色泽及其毒理特性的影响。创新要点:在pH 9.0~12.0的热处理条件下,牛乳酪蛋白源ACE抑制肽的抑制活性降低,色泽加深。热处理后的ACE抑制肽对Caco-2细胞和ECV-304细胞没有毒性作用。研究方法:以ACE抑制活性、游离氨基、色差值和细胞存活率为检测指标,研究了酸碱热处理对ACE抑制肽的稳定性和毒理特性影响。重要结论:高温和碱性热处理能破坏酪蛋白源ACE抑制肽的稳定性。     

高锰酸钾-乙二醛化学发光体系测定谷氨酸

建立了测定谷氨酸的化学发光新方法,确定了该方法的测定最佳条件,并研究了抑制体系的机理。在最佳条件下,谷氨酸浓度在2．0×10^-8-5．0×10^-5mol·L^-1范围内与相对发光强度成正比,方法的检出限为6．0×10^-9mol·L^-1,对1．0×10^-6mol·L^-1的谷氨酸平行测定9次,相对标准偏差为2．5％。该法用于味精产品中谷氨酸含量分析。     

不同酶解胶原肽的制备及抗氧化活性研究

为了探究酶种类对酶解胶原肽抗氧化活性的影响,以罗非鱼鱼皮为材料,用碱性蛋白酶、中性蛋白酶和胰蛋白酶酶解得到三种胶原肽,比较其对DPPH、·OH和O~-_2·自由基清除能力.结果显示,碱性蛋白酶胶原肽、中性蛋白酶胶原肽和胰蛋白酶胶原肽均具有抗氧化活性,其中碱性蛋白酶胶原肽对DPPH、·OH和O~-_2·自由基清除能力优于中性蛋白酶胶原肽和胰蛋白酶胶原肽,且三种胶原肽抗氧化活性与其水解度呈正相关.     

艾滋病及其治疗的最新进展

艾滋病是人体感染人类免疫缺陷病毒(HIV)引起的获得性免疫缺陷综合征。人体感染HIV后的临床表现分为急性期、无症状期和艾滋病期。高效抗逆转录病毒疗法(HAART)是目前临床上治疗艾滋病的主要方法,该方法能够有效控制病毒载量,重建患者的免疫功能,但无法彻底清除体内的病毒。一旦停止给药,患者体内HIV病毒会在两周内出现反弹,患者须通过终身服药来控制病情的发展。CCR5是HIV侵染细胞的辅助受体,针对CCR5的基因疗法可能会达到完全清除感染者体内HIV的效果,但其将来是否能真正作为一种艾滋病的临床治疗手段目前还难以定论。     

DEA两个基本模型研究概述

主要探讨了DEA中的两个基本模型．首先,简要回顾了有关DEA模型的研究进展;接着,介绍了DEA研究中常用的两个基本模型：CCR模型及BCC模型,以及基于CCR模型的其他相关模型;最后,对CCR模型和BCC模型做了比较分析,并指出CCR模型和BCC模型各自的生产可行性／可能性集合是不同的．因此,CCR模型的边界具有线性特征,而BCC模型的边界具有分段线性特征,并呈现凹特性．     

HIV-1整合酶肽抑制剂的研究进展

目前治疗人类免疫缺陷Ⅰ型病毒(HIV-1)感染的方法主要是针对靶点逆转录酶(RT)和整合酶(IN)联合用药.联合治疗方法有很多的临床优势,但高抗药性的出现,迫切需要能研究抗HIV-1新药物.新药物需要能与病毒复制周期另外的一些步骤中关键蛋白发生作用,比如在宿主基因组中整合病毒DNA.基于这些考虑,目前国际上研究肽化合物药物成为一个热点,一些肽化合物在体内及体外实验中,对RT和IN均产生了很大的抑制活性.本文综述了随着最近一些新技术的出现而挑选出的对目标蛋白有强结合力的肽.这些新技术的出现为研究抗HIV-1药物提供了一种新方法.     

判断CCR相对有效性的一个新的简便模型

将Hadamard乘积算子引入到传统的CCR模型中,定义一种新的DEA线性规划模型,并给出它的对偶规划.该模型避免了非阿基米德无穷小CCR模型的参数依赖问题,同时也避免了两阶段方法的双规划计算量问题.根据该模型的任一个最优解,可容易判断决策单元的CCR相对有效性,也较容易根据各相对有效值测度计算各决策单元的相对有效值,同时可判断决策单元的相对有效性.     

抑癌基因P16的研究进展

多肿瘤抑制基因(MTSl／P16／CDKN2)定位于第九号染色体短臀2区1带，编码一个16KD的蛋白质(P16)，P16蛋白是周期素依赖性激酶4(CDK4)的抑制因子，能抑制细胞的生长和分裂。P16基因主要通过缺失、点突变和CpG岛异常甲基化而失活，已经证实该基因的失活与多种组织的肿瘤形成有关。本文就P16基因的发现、抑癌机制、临床研究及展望作一综述。     

Extracellular HIV Tat and Tat cysteine rich peptide increase CCR5 expression in monocytes

In our previous work we reported that HIV Tat and 6 cysteine rich peptides of Tat induce tumor necrosis factor-related apoptosis-induced ligand (TRAIL) in human monocytes (Yang et al., 2003). Here our results showed that HIV Tat and Tat cysteine rich peptide increase CCR5 expression in human monocytes, and this activity is inhibited by rabbit anti-Tat. Boiled Tat does not increase CCR5 expression in monocytes. These results provide insight into a new mechanism by which HIV Tat plays a key role in the pathogenesis of HIV-1 infection.     

Science Letters:Assignment of CCR7 gene to chicken chromosome 27 by radiation hybrid panel mapping

The protein encoded by CC chemokine receptor 7 (CCR7) is a member of the G protein-coupled receptor family. This receptor was identified as a gene induced by the Epstein-Barr virus (EBV), and is thought to be a mediator of EBV effects on B lymphocytes. This receptor is expressed in various lymphoid tissues and activates B and T lymphocytes. It has been shown to control the migration of memory T cells to inflamed tissues, as well as stimulate dendritic cell maturation. To map the CCR7 gene in chicken chromosome, a 6 000 rads chicken-hamster radiation hybrid panel (ChickRH6) was used. PCR of samples from ChickRH6 revealed that the location of CCR7 gene is linked to the maker SEQ0347 (6 cR away) with LOD score of 16.6 and that the marker SEQ0347 is located on chromosome 27 at 27 cR of RH (radiation hydrid) map. We compared the corresponding human mRNA sequence with the predicted coding sequence of chicken CCR7 gene, and found that the assembled contig shared a high percentage of similarity with that of the human gene.     

Phenotypic and functional characteristics of dendritic cells derived from human peripheral blood monocytes

INTRODUCTION Dendritic cells(DCs)are professional anti-gen-presenting cells(APC)that are responsible for the activation of undifferentiated T cells and the generation of primary T-cell responses(Cella et al.,1997).The specific role of DCs is to capture,process and present antigens to T cells.Immunogenic and inflammatory signals are responsible for the migra-tion of DCs from tissues to lymphoid organs where they initiate an immune response.These processes induce the maturation of DCs…     

Assignment of <Emphasis Type="Italic">CCR7</Emphasis> gene to chicken chromosome 27 by radiation hybrid panel mapping

The protein encoded by CC chemokine receptor 7 （CCR7） is a member of the G protein-coupled receptor family. This receptor was identified as a gene induced by the Epstein-Barr virus （EBV）, and is thought to be a mediator of EBV effects on B lymphocytes. This receptor is expressed in various lymphoid tissues and activates B and T lymphocytes. It has been shown to control the migration of memory T cells to inflamed tissues, as well as stimulate dendritic cell maturation. To map the CCR7 gene in chicken chromosome, a 6000 rads chicken-hamster radiation hybrid panel （ChickRH6） was used. PCR of samples from ChickRH6 revealed that the location of CCR7 gene is linked to the maker SEQ0347 （6 cR away） with LOD score of 16.6 and that the marker SEQ0347 is located on chromosome 27 at 27 cR of RH （radiation hydrid） map. We compared the corresponding human mRNA sequence with the predicted coding sequence of chicken CCR7 gene, and found that the assembled contig shared a high percentage of similarity with that of the human gene.     

Molecular dynamics simulation of the interactions between EHD1 EH domain and multiple peptides

Objective: To provide essential information for peptide inhibitor design, the interactions of Eps15 homology domain of Eps15 homology domain-containing protein 1 (EHD1 EH domain) with three peptides containing NPF (asparagine-proline-phenylalanine), DPF (aspartic acid-proline-phenylalanine), and GPF (glycine-proline-phenylalanine) motifs were deciphered at the atomic level. The binding affinities and the underlying structure basis were investigated. Methods: Molecular dynamics (MD) simulations were performed on EHD1 EH domain/peptide complexes for 60 ns using the GROMACS package. The binding free energies were calculated and decomposed by molecular mechanics/generalized Born surface area (MM/GBSA) method using the AMBER package. The alanine scanning was performed to evaluate the binding hot spot residues using FoldX software. Results: The different binding affinities for the three peptides were affected dominantly by van der Waals interactions. Intermolecular hydrogen bonds provide the structural basis of contributions of van der Waals interactions of the flanking residues to the binding. Conclusions: van der Waals interactions should be the main consideration when we design peptide inhibitors of EHD1 EH domain with high affinities. The ability to form intermolecular hydrogen bonds with protein residues can be used as the factor for choosing the flanking residues.     

A simple method for removing low-density granulocytes to purify T lymphocytes from peripheral blood mononuclear cells

Objectives

Low-density granulocytes (LDGs) can form neutrophil extracellular traps (NETs) spontaneously and excessively. When peripheral blood mononuclear cells (PBMCs) are used for studying T lymphocytes, LDGs contained in the PBMCs may decrease the threshold of activating T lymphocytes by forming NETs. This study focused on the profiles of LDGs in common autoimmune diseases and methods for removing LDGs from PBMCs.

Methods

The percentages of LDGs in PBMCs from 55 patients with dermatomyositis (DM), 15 with polymyositis (PM), 42 with rheumatoid arthritis (RA), 25 with systemic lupus erythematosus (SLE), and 19 healthy controls were determined by flow cytometry. Three methods of removing LDGs were explored and compared. After removal, PBMCs from six patients with positive T-SPOT.TB were tested again to find out if LDGs contained in the PBMCs could influence T lymphocyte reactions.

Results

Significantly higher LDG percentages were found in PBMCs from patients with DM ((8.41±10.87)%, P<0.0001), PM ((8.41±10.39)%, P<0.0001), RA ((4.05±6.97)%, P=0.0249), and SLE ((7.53±11.52)%, P=0.0006), compared with the controls ((1.28±0.73)%). The T-SPOT.TB values significantly decreased after LDGs were removed. Increasing relative centrifugal force (RCF) within a limited range can decrease the LDG percentage from an initial high level, but not markedly increase the LDG clearance rate. Compared with the whole blood sediment method, the PBMC adherence method can significantly remove LDGs yet scarcely influence the T lymphocyte percentage in PBMCs.

Conclusion

The LDG percentage in PBMCs is significantly increased in patients with SLE, DM, PM, and RA. The influence of LDGs on T lymphocytes cannot be ignored in PBMC cultures. The adherence method is a simple and easy-to-use method for removing LDGs and purifying T lymphocytes from PBMCs.

     

The International Baccalaureate Career Programme: a case study of college and career readiness policy goals

The International Baccalaureate (IB) is noted in school reform policy circles as the gold standard of academic excellence. While the presence of IB as a sought-after education vendor has grown in the past decade, the organization has attempted to shake off its image as an elite agency serving only private international schools with its longstanding liberal arts curriculum. As such its turn toward the public sector in the United States with a credential for vocational students appears perplexing and out of step with its product brand, but the newer Career Programme (CP) is marketed as meeting the needs of applied learners in secondary schools. This paper offers a case study of two schools in one US state that adopted the CP, generating IB school enrollments from among talented vocational students while elevating its ranking on the college and career readiness (CCR) score, an annual assessment of postsecondary success. The CCR policy reformers advocate curricular improvements so that all students receive the academic foundations and employability skills needed to thrive in the new economy. Yet the egalitarian discourse of CCR could not be attended to using the CP. In this case study only high-achieving students were advised to participate and enroll in the program.