抗TNF-α治疗

TNF α主要是由一种活化的单核 巨噬细胞产生的一种细胞因子 ,具有多种生物学效应 ,研究表明 :适量的TNF α在宿主抵抗微生物入侵和抑制肿瘤产生的防御系统中起着关键作用 ,但过量的TNF α与其它炎性因子一起产生多种病理性损伤。TNF α与感染性疾病、自身免疫性疾病、器官衰竭等其它疾病有直接关系。通过抑制TNF α的活性作用有可能对与TNF α有关的疾病产生治疗作用 ,目前在败血症、类风湿关节炎、克罗恩病、银屑病、心力衰竭等疾病的治疗中具有特殊疗效。以TNF α为靶点开发的药物包括 :抑制TNF α生成的药物和直接作用于TNF α中和其活性的药物 ,这些药物从不同层次不同水平抑制TNF α的产生和发生作用从而达到抗TNF α治疗的目的。临床研究表明抗TNF α治疗的药物是安全的。     

“七五”攻关期间我国医药生物技术产品研究开发进展

医药生物技术做为当今生物技术的主要研究领域之一已取得了令人瞩目的成就。在美国,目前投放市场的生物技术产品绝大部分为医药产品,它们的开发具有速度快、产品数量多、疾病谱广、经济效益显著等特点。我国政府对医药生物技术的研究开发给予了高度的重视,据不完全统计,“七五”攻关期间组织了1200多人的研究队伍,投入了3500多万元的科研经费进行医药生物技术的研究开发工作。     

急性力竭运动对大鼠心肌PKCα、δ和ε表达的影响

目的：检测分析急性力竭运动对大鼠心肌蛋白激酶C（PKC）α、δ和ε亚型总蛋白及其磷酸化蛋白表达的影响。方法：健康雄性SD大鼠50只,随机分为对照组（C组）和急性力竭运动组（AEE组）（n=25）,采用一次力竭跑台运动建立急性力竭运动模型,Western blot法检测PKCα、δ和ε总蛋白及其磷酸化蛋白的表达水平。结果：与C组比较,AEE组大鼠心肌PKCα、p-PKCα^Ser-657、PKCδ、p-PKCδ^Thr-507及PKCε水平均显著升高（P<0.05）。结论：急性力竭运动导致PKCα、PKCδ、PKCε表达水平和PKCα、PKCδ活化水平上调,可能是急性力竭运动导致大鼠心肌损伤的重要因素,三亚型之间的交互作用可能是更重要的因素。     

IκB激酶研究进展

NFκB是一类具有重要生理功能的转录因子,能调节许多细胞基因的表达,在细胞的生理活动中具有重要作用。在静息细胞中,NFκB以无活性的形式存在于胞质中。受信号刺激后,NFκB被激活。IκB激酶在NFκB激活中起着重要作用。介绍了IκB激酶的组成、活性调控及生理功能 。     

免疫融合蛋白sFcεRIα/mIg(IgG2)的研制

哮喘、过敏性鼻炎、特应性皮炎及食物过敏等疾病为一类常见疾病,但存在治疗效果不佳,患者病程长等特点。IgE 分子是导致过敏性疾病的关键分子。抑制IgE分子与效应细胞膜表面FcεRI受体的结合可抑制过敏反应的发生。通过克隆FcεRI受体α亚基的cDNA与IgG2的稳定区铰链区、CH2和CH3的cDNA连接,以二聚化融合蛋白sFcεRIα/mIg(IgG2)的形式在CHO细胞中表达,达到提高sFcεRIα生物半衰期的目的。表达载体构建和初步的功能性试验等一系列研究证实,所表达的融合蛋白的分子量为170kDa,并与人IgE和鼠IgE有较好的结合活性。这些研究为该融合蛋白最终实现产业化打下良好基础。     

依赖于微环境的TGFβ信号

转化生长因子β（transforming growth factor β,TGFβ）家族成员是一类分泌的细胞因子,在胚胎发育、免疫调节、伤口修复、细胞增殖和抑制等过程中发挥重要作用。其中,TGFβ1、TGFβ2和TGFβ3在进化上最晚出现,并以潜伏态分泌。有别于家族中的大多数成员,TGFβ1-3的信号具有时空区域性,并依赖于其所处的微环境。阐明依赖于微环境的TGFβ信号的多层次调控机制对于理解TGFβ信号在免疫、癌症等生理、病理条件下的功能,以及开发临床治疗策略具有重要意义。本文从TGFβ前体复合物的结构入手,并从TGFβ的激活,配体-受体识别,跨膜信号传导及转录调控等方面,论述依赖于微环境的TGFβ信号的调控机制,同时讨论肿瘤微环境中多效的TGFβ信号,进而对今后的研究方向进行展望。     

依赖于微环境的TGFβ信号

转化生长因子β（transforming growth factor β，TGFβ）家族成员是一类分泌的细胞因子，在胚胎发育、免疫调节、伤口修复、细胞增殖和抑制等过程中发挥重要作用。其中,TGFβ1、TGFβ2和TGFβ3在进化上最晚出现，并以潜伏态分泌。有别于家族中的大多数成员，TGFβ1-3的信号具有时空区域性，并依赖于其所处的微环境。阐明依赖于微环境的TGFβ信号的多层次调控机制对于理解TGFβ信号在免疫、癌症等生理、病理条件下的功能，以及开发临床治疗策略具有重要意义。本文从TGFβ前体复合物的结构入手，并从TGFβ的激活，配体-受体识别，跨膜信号传导及转录调控等方面，论述依赖于微环境的TGFβ信号的调控机制，同时讨论肿瘤微环境中多效的TGFβ信号，进而对今后的研究方向进行展望。     

抑制LRP16基因的表达显著下调TNF-α介导的NF-κB转录活性

LRP16是1个雌激素(E2)通过其受体α(ERα)诱导表达的靶基因.研究表 明,LRP16可以作为多种核受体（包括AR、ERα）的转录共激活因子.采用荧光素酶报 告检测显示,抑制LRP16基因表达显著削弱了TNF-α(10 ng/mL)介导的NF-κB转录活性;采用免疫荧光和Western印迹法研究抑制LRP16对NF-κB/p65亚基核转位的影响,结果显示,抑制LRP16表达并不能参与影响p65亚基核转位．上述结果提示,LRP16可能以核激活因子角色参与了NF-κB介导的信号途径．RT-PCR实验检测抑制LRP16基因表达对TNF-α诱导NF-κB靶基因调控作用,检测的靶基因包括IκB、A20、IL-8、 FLIP、XIAP.结果表明,在这些靶基因中只有XIAP、cIAP2产生了明显的下调趋势. 因此,LRP16是NF-κB的1个共激活因子,通过调控NF-κB与靶基因的结合能力,从而增强了NF-κB的转录活性.     

香菇‘豫香2号’的选育报告

‘豫香2号’是从河南省卢氏县伏牛山地区采集的野生香菇子实体,经过多次组织分离和驯化等系统选育而获得的优良品种,适宜河南省中高海拔区域种植。该品种子实体中等,多单生,菌盖圆整、浅褐色,菌柄呈倒圆锥形,产量高,鲜销耐储存。     

Preparation of hair for measurement of elements by inductively coupled plasma-mass spectrometry (ICP-MS)

The preparation of hair for the determination of elements is a critical component of the analysis procedure. Open-beaker, closedvessel microwave, and flowthrough microwave digestion are methods that have been used for sample preparation and are discussed. A new digestion method for use with inductively coupled plasma-mass spectrometry (ICP-MS) has been developed. The method uses 0.2 g of hair and 3 mL of concentrated nitric acid in an atmospheric pressurelow-temperature microwave digestion (APLTMD) system. This preparation method is useful in handling a large numbers of samples per day and may be adapted to hair sample weights ranging from 0.08 to 0.3 g. After digestion, samples are analyzed by ICP-MS to determine the concentration of Li, Be, B, Na, Mg, Al, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, As, Se, Rb, Sr, Zr, Mo, Pd, Ag, Cd, Sn, Sb, I, Cs, Ba, Pt, Au, Hg, Tl, Pb, Bi, Th, and U. Benefits of the APLTMD include reduced contamination and sample handling, and increased precision, reliability, and sample throughput.     

Genetic Manipulation in Δku80 Strains for Functional Genomic Analysis of Toxoplasma gondii

Targeted genetic manipulation using homologous recombination is the method of choice for functional genomic analysis to obtain a detailed view of gene function and phenotype(s). The development of mutant strains with targeted gene deletions, targeted mutations, complemented gene function, and/or tagged genes provides powerful strategies to address gene function, particularly if these genetic manipulations can be efficiently targeted to the gene locus of interest using integration mediated by double cross over homologous recombination.Due to very high rates of nonhomologous recombination, functional genomic analysis of Toxoplasma gondii has been previously limited by the absence of efficient methods for targeting gene deletions and gene replacements to specific genetic loci. Recently, we abolished the major pathway of nonhomologous recombination in type I and type II strains of T. gondii by deleting the gene encoding the KU80 protein^1,2. The Δku80 strains behave normally during tachyzoite (acute) and bradyzoite (chronic) stages in vitro and in vivo and exhibit essentially a 100% frequency of homologous recombination. The Δku80 strains make functional genomic studies feasible on the single gene as well as on the genome scale^1-4.Here, we report methods for using type I and type II Δku80Δhxgprt strains to advance gene targeting approaches in T. gondii. We outline efficient methods for generating gene deletions, gene replacements, and tagged genes by targeted insertion or deletion of the hypoxanthine-xanthine-guanine phosphoribosyltransferase (HXGPRT) selectable marker. The described gene targeting protocol can be used in a variety of ways in Δku80 strains to advance functional analysis of the parasite genome and to develop single strains that carry multiple targeted genetic manipulations. The application of this genetic method and subsequent phenotypic assays will reveal fundamental and unique aspects of the biology of T. gondii and related significant human pathogens that cause malaria (Plasmodium sp.) and cryptosporidiosis (Cryptosporidium).     

A phylogenetic analysis of 100+ genera and 50+ families of euasterids based on morphological and molecular data with notes on possible higher level morphological synapomorphies

 A data matrix of 143 morphological and chemical characters for 142 genera of euasterids according to the APG system was compiled and complemented with rbcL and ndhF sequences for most of the genera. The data were subjected to parsimony analysis and support was assessed by bootstrapping. Strict consensus trees from analyses of morphology alone and morphology + rbcL + ndhF are presented. The morphological data recover several groups supported by molecular data but at the level of orders and above relationships are only superficially in agreement with molecular studies. The analyses provide support for monophyly of Gentianales, Aquifoliales, Apiales, Asterales, and Dipsacales. All data indicate that Adoxaceae are closely related to Dipsacales and hence they should be included in that order. The trees were used to assess some possible morphological synapomorphies for euasterids I and II and for the orders of the APG system. Euasterids I are generally characterised by opposite leaves, entire leaf margins, hypogynous flowers, “early sympetaly” with a ring-shaped corolla primordium, fusion of stamen filaments with the corolla tube, and capsular fruits. Euasterids II often have alternate leaves, serrate-dentate leaf margins, epigynous flowers, “late sympetaly” with distinct petal primordia, free stamen filaments, and indehiscent fruits. It is unclear which of these characters represent synapomorphies and symplesiomorphies for the two groups, respectively, and there are numerous expections to be interpreted as reversals and parallelisms. Received August 28, 2000 Accepted August 7, 2001     

Mechanisms and ecological consequences of plant defence induction and suppression in herbivore communities

Background Plants are hotbeds for parasites such as arthropod herbivores, which acquire nutrients and energy from their hosts in order to grow and reproduce. Hence plants are selected to evolve resistance, which in turn selects for herbivores that can cope with this resistance. To preserve their fitness when attacked by herbivores, plants can employ complex strategies that include reallocation of resources and the production of defensive metabolites and structures. Plant defences can be either prefabricated or be produced only upon attack. Those that are ready-made are referred to as constitutive defences. Some constitutive defences are operational at any time while others require activation. Defences produced only when herbivores are present are referred to as induced defences. These can be established via de novo biosynthesis of defensive substances or via modifications of prefabricated substances and consequently these are active only when needed. Inducibility of defence may serve to save energy and to prevent self-intoxication but also implies that there is a delay in these defences becoming operational. Induced defences can be characterized by alterations in plant morphology and molecular chemistry and are associated with a decrease in herbivore performance. These alterations are set in motion by signals generated by herbivores. Finally, a subset of induced metabolites are released into the air as volatiles and function as a beacon for foraging natural enemies searching for prey, and this is referred to as induced indirect defence.Scope The objective of this review is to evaluate (1) which strategies plants have evolved to cope with herbivores and (2) which traits herbivores have evolved that enable them to counter these defences. The primary focus is on the induction and suppression of plant defences and the review outlines how the palette of traits that determine induction/suppression of, and resistance/susceptibility of herbivores to, plant defences can give rise to exploitative competition and facilitation within ecological communities “inhabiting” a plant.Conclusions Herbivores have evolved diverse strategies, which are not mutually exclusive, to decrease the negative effects of plant defences in order to maximize the conversion of plant material into offspring. Numerous adaptations have been found in herbivores, enabling them to dismantle or bypass defensive barriers, to avoid tissues with relatively high levels of defensive chemicals or to metabolize these chemicals once ingested. In addition, some herbivores interfere with the onset or completion of induced plant defences, resulting in the plant’s resistance being partly or fully suppressed. The ability to suppress induced plant defences appears to occur across plant parasites from different kingdoms, including herbivorous arthropods, and there is remarkable diversity in suppression mechanisms. Suppression may strongly affect the structure of the food web, because the ability to suppress the activation of defences of a communal host may facilitate competitors, whereas the ability of a herbivore to cope with activated plant defences will not. Further characterization of the mechanisms and traits that give rise to suppression of plant defences will enable us to determine their role in shaping direct and indirect interactions in food webs and the extent to which these determine the coexistence and persistence of species.     

Angiosperm ovules: diversity, development, evolution

Background

Ovules as developmental precursors of seeds are organs of central importance in angiosperm flowers and can be traced back in evolution to the earliest seed plants. Angiosperm ovules are diverse in their position in the ovary, nucellus thickness, number and thickness of integuments, degree and direction of curvature, and histological differentiations. There is a large body of literature on this diversity, and various views on its evolution have been proposed over the course of time. Most recently evo–devo studies have been concentrated on molecular developmental genetics in ovules of model plants.

Scope

The present review provides a synthetic treatment of several aspects of the sporophytic part of ovule diversity, development and evolution, based on extensive research on the vast original literature and on experience from my own comparative studies in a broad range of angiosperm clades.

Conclusions

In angiosperms the presence of an outer integument appears to be instrumental for ovule curvature, as indicated from studies on ovule diversity through the major clades of angiosperms, molecular developmental genetics in model species, abnormal ovules in a broad range of angiosperms, and comparison with gymnosperms with curved ovules. Lobation of integuments is not an atavism indicating evolution from telomes, but simply a morphogenetic constraint from the necessity of closure of the micropyle. Ovule shape is partly dependent on locule architecture, which is especially indicated by the occurrence of orthotropous ovules. Some ovule features are even more conservative than earlier assumed and thus of special interest in angiosperm macrosystematics.     

Genome Similarity Implies that Citrus-Parasitic Burrowing Nematodes do not Represent a Unique Species

Burrowing nematodes from Central America, Dominican Republic, Florida, Guadeloupe, Hawaii, and Puerto Rico were characterized for their ability to parasitize citrus, but citrus parasites were found only in Florida. Sequence tag sites originally amplified from a citrus-parasitic burrowing nematode were polymorphic among 37 burrowing nematode isolates and were not correlated with citrus parasitism, nematode isolate collection site, or amplification of a 2.4-kb sequence tag site (DK#1). Results of a RAPD analysis and characterization of the isozymes phosphoglucose isomerase, lactate dehydrogenase, and malate dehydrogenase indicated that the burrowing nematode isolates were highly similar. Citrus parasitism in Florida appears to be associated with limited changes in the burrowing nematode genome. Findings did not substantiate a previous report that R. citrophilus was present in Hawaii. Overall, these data do not support assignment of sibling species status to burrowing nematodes that differ with respect to citrus parasitism.     

Assessing burrowing, nest construction, and hoarding in mice

Deterioration in the ability to perform "Activities of daily living" (ADL) is an early sign of Alzheimer's disease (AD). Preclinical behavioural screening of possible treatments for AD currently largely focuses on cognitive testing, which frequently demands expensive equipment and lots of experimenter time. However, human episodic memory (the most severely affected aspect of memory in AD) is different to rodent memory, which seems to be largely non-episodic. Therefore the present ways of screening for new AD treatments for AD in rodents are intrinsically unlikely to succeed. A new approach to preclinical screening would be to characterise the ADL of mice. Fortuitously, several such assays have recently been developed at Oxford, and here the three most sensitive and well-characterised are presented. Burrowing was first developed in Oxford. It evolved from a need to develop a mouse hoarding paradigm. Most published rodent hoarding paradigms required a distant food source to be linked to the home cage by a connecting passage. This would involve modifying the home cage as well as making a mouse-proof connecting passage and food source. So it was considered whether it would be possible to put the food source inside the cage. It was found that if a container was placed on the floor it was emptied by the next morning., The food pellets were, however, simply deposited in a heap at the container entrance, rather than placed in a discrete place away from the container, as might be expected if the mice were truly hoarding them. Close inspection showed that the mice were performing digging ("burrowing") movements, not carrying the pellets in their mouths to a selected place as they would if truly hoarding them. Food pellets are not an essential substrate for burrowing; mice will empty tubes filled with sand, gravel, even soiled bedding from their own cage. Moreover, they will empty a full tube even if an empty one is placed next to it. Several nesting protocols exist in the literature. The present Oxford one simplifies the procedure and has a well-defined scoring system for nest quality. A hoarding paradigm was later developed in which the mice, rather than hoarding back to the real home cage, were adapted to living in the "home base" of a hoarding apparatus. This home base was connected to a tube made of wire mesh, the distal end of which contained the food source. This arrangement proved to yield good hoarding behaviour, as long as the mice were adapted to living in the "home base" during the day and only allowed to enter the hoarding tube at night.     

A Simple Protocol for Platelet-mediated Clumping of Plasmodium falciparum-infected Erythrocytes in a Resource Poor Setting

P. falciparum causes the majority of severe malarial infections. The pathophysiological mechanisms underlying cerebral malaria (CM) are not fully understood and several hypotheses have been put forward, including mechanical obstruction of microvessels by P. falciparum-parasitized red blood cells (pRBC). Indeed, during the intra-erythrocytic stage of its life cycle, P. falciparum has the unique ability to modify the surface of the infected erythrocyte by exporting surface antigens with varying adhesive properties onto the RBC membrane. This allows the sequestration of pRBC in multiple tissues and organs by adhesion to endothelial cells lining the microvasculature of post-capillary venules ¹. By doing so, the mature forms of the parasite avoid splenic clearance of the deformed infected erythrocytes ² and restrict their environment to a more favorable low oxygen pressure ³. As a consequence of this sequestration, it is only immature asexual parasites and gametocytes that can be detected in peripheral blood.Cytoadherence and sequestration of mature pRBC to the numerous host receptors expressed on microvascular beds occurs in severe and uncomplicated disease. However, several lines of evidence suggest that only specific adhesive phenotypes are likely to be associated with severe pathological outcomes of malaria. One example of such specific host-parasite interactions has been demonstrated in vitro, where the ability of intercellular adhesion molecule-1 to support binding of pRBC with particular adhesive properties has been linked to development of cerebral malaria ^4,5. The placenta has also been recognized as a site of preferential pRBC accumulation in malaria-infected pregnant women, with chondrotin sulphate A expressed on syncytiotrophoblasts that line the placental intervillous space as the main receptor ⁶. Rosetting of pRBC to uninfected erythrocytes via the complement receptor 1 (CD35)^7,8 has also been associated with severe disease ⁹.One of the most recently described P. falciparum cytoadherence phenotypes is the ability of the pRBC to form platelet-mediated clumps in vitro. The formation of such pRBC clumps requires CD36, a glycoprotein expressed on the surface of platelets. Another human receptor, gC1qR/HABP1/p32, expressed on diverse cell types including endothelial cells and platelets, has also been shown to facilitate pRBC adhesion on platelets to form clumps ¹⁰. Whether clumping occurs in vivo remains unclear, but it may account for the significant accumulation of platelets described in brain microvasculature of Malawian children who died from CM ¹¹. In addition, the ability of clinical isolate cultures to clump in vitro was directly linked to the severity of disease in Malawian ¹² and Mozambican patients ¹³, (although not in Malian ¹⁴).With several aspects of the pRBC clumping phenotype poorly characterized, current studies on this subject have not followed a standardized procedure. This is an important issue because of the known high variability inherent in the assay ¹⁵. Here, we present a method for in vitro platelet-mediated clumping of P. falciparum with hopes that it will provide a platform for a consistent method for other groups and raise awareness of the limitations in investigating this phenotype in future studies. Being based in Malawi, we provide a protocol specifically designed for a limited resource setting, with the advantage that freshly collected clinical isolates can be examined for phenotype without need for cryopreservation.     

日本北海道虻类雌性外生殖器形态(双翅目：虻科)(英文)

【目的】利用日本北海道虻类评估和验证外生殖器在分类学上的意义。【方法】将虻类成虫标本浸渍在生理盐水中并置于双目显微镜下通过针和镊子在培养皿中进行解剖并绘图,观察第9背板、第10背板、尾叶、第8腹板、受精囊、受精囊管及生殖叉器的形态特征。【结果】在日本北海道共记录了虻科(Tabanidae) 3亚科7属38种。我们观察并描述了3亚科其中的6属24种的雌性外生殖器的主要特征。亚科之间存在明显差异;然而在一般情况下属之间很难建立一种方法来确定共同点;种之间只有在斑虻属Chrysops中有相似之处,其他属中则比较多样化。因此,亚科鉴定根据第9背板、第8腹板及受精囊足以进行区分,属及种鉴定需要结合第9背板、第10背板、尾叶、第8腹板、受精囊、受精囊管及生殖叉器各自的特征组合在一起才能区分开来。我们也制作了虻类外生殖器的检索表。【结论】和许多其他昆虫一样,外生殖器是虻科的重要分类特征,对于促进分类学和系统学的发展具有重要意义。本研究首次对分布在日本北海道的虻科雌性外生殖器进行了系统研究。     

外泌体在白血病中的重要调控作用

目前,白血病复发是患者死亡的主要原因之一。肿瘤细胞和微环境的相互作用,以及隐匿在骨髓中的肿瘤干细胞,促进了白血病的复发和向淋巴组织的转移,因此白血病的治疗、转移和复发问题受到广泛关注。外泌体是由绝大多数细胞分泌的双层脂质膜囊泡,可以调控细胞间的交流和信息传递。在白血病细胞、基质细胞和内皮细胞之间的相互联系中都涉及到外泌体,白血病细胞来源的外泌体存在于白血病患者的血浆中,能把其携带的白血病相关抗原及微小RNA呈递给靶细胞,促进白血病肿瘤细胞的增殖,有助于肿瘤细胞实现免疫逃避,保护白血病细胞抵抗化疗药物导致的细胞毒性作用,促进血管生成及肿瘤细胞的迁移。因此,外泌体与白血病的转移、治疗及预后密切相关,可以用来检测和监测白血病的进展。本文综述了外泌体的来源、形成与分泌机制,以及外泌体在白血病发生前、发展中、预后和免疫治疗中所扮演的重要角色。