我国人粒细胞无形体病的研究进展

人粒细胞无形体病是由嗜吞噬细胞无形体引起的一种经蜱传播的人畜共患病。近年来,在美国、欧洲、非洲等地均有相关病例报道,我国也有病例发现。该病主要引起发热,血小板减少,严重可引起多脏器损害,甚至死亡。因此日益受到研究者们的关注与重视。本文分别从HGA的发现,临床特点,治疗,预防等方面介绍人粒细胞无形体病的研究进展。     

我国人粒细胞无形体病的研究进展

人粒细胞无形体病是由嗜吞噬细胞无形体引起的一种经蜱传播的人畜共患病。近年来,在美国、欧洲、非洲等地均有相关病例报道,我国也有病例发现。该病主要引起发热,血小板减少,严重可引起多脏器损害,甚至死亡。因此日益受到研究者们的关注与重视。本文分别从HGA的发现,临床特点,治疗,预防等方面介绍人粒细胞无形体病的研究进展。     

嗜吞噬细胞无形体aph0653的克隆表达及重组蛋白的抗原性分析

目的:克隆表达嗜吞噬细胞无形体(Anaplasma phagocytophilum,AP)APH0653基因,并对表达产物进行抗原性分析。方法:以嗜吞噬细胞无形体基因组DNA为模板,使用特异性引物,PCR扩增APH0653基因并克隆入原核表达载体进行表达。使用镍柱亲和层析纯化重组蛋白,并应用免疫印迹方法检测APH0653与嗜吞噬细胞无形体感染血清的免疫反应性。结果:菌落PCR、DNA测序和SDS-PAGE蛋白凝胶电泳表明APH0653基因已成功克隆入原核表达载体,并可诱导表达重组蛋白。免疫印迹实验表明AP阳性血清可识别重组蛋白APH0653,并产生明显的特异性条带。结论:嗜吞噬细胞无形体APH0653蛋白可在原核表达系统中高效表达,且重组蛋白具有较好的抗原性。     

淋巴细胞与免疫的关系

与免疫关系最密切的细胞,有淋巴细胞、浆细胞、单核-吞噬细胞、中性粒细胞、嗜碱粒细胞-肥大细胞和嗜酸粒细胞等,然而参与机体特异性免疫的细胞主要是淋巴细胞和吞噬细胞。本文只简单介绍淋巴细胞与免疫的关系。淋巴细胞主要存在于人体血液和淋巴器官脾、淋巴结和胸腺中。六十年代前,曾把小淋巴     

嗜吞噬细胞无形体msp4蛋白的生物信息学分析及表达鉴定

分析预测嗜吞噬细胞无形体msp4蛋白的抗原性,对嗜吞噬细胞无形体的msp4蛋白采用生物信息学对其进行分析二级结构,亲水性,疏水性,B细胞线性表位;根据分析的优势抗原表位区,进行基因合成并亚克隆至p ET32a表达载体,在大肠埃希菌中获得重组蛋白。生物信息学分析结果显示msp4蛋白由283个氨基酸组成,分子量为29.8 ku,理论等电点为6.05,不稳定系数为32.79,总平均疏水性为0.063;二级结构预测msp4蛋白主要以无规卷曲、延伸链、α-螺旋为主;B细胞表位预测msp4蛋白有14个线性表位;根据分析的结果选取msp4蛋白亲水性高的膜外区的28-158位序列克隆至p ET32a进行原核表达,在34 ku出有目的蛋白的表达。成功对嗜吞噬细胞无形体的msp4蛋白原核表达及纯化,为无形体病血清学检测方法的建立奠定了物质基础。     

欧洲鳗鲡外周血细胞的显微和超微结构

利用光镜和透射电镜技术研究了欧洲鳗鲡（Anguilla anguilla）外周血细胞的显微和亚显微结构。结果表明：在外周血细胞中可以区分出红细胞、单核细胞、大淋巴细胞、小淋巴细胞、嗜中性粒细胞和血栓细胞;嗜中性粒细胞内的特殊颗粒包括A、B、C三型;嗜中性粒细胞分为Ⅰ型粒细胞（内含A、B、C三种特殊颗粒）、Ⅱ型粒细胞（内含A型和C型两种特殊颗粒）和Ⅲ型粒细胞（内含C型特殊颗粒）。还见到幼稚的和正在分裂的红细胞和单核细胞,提示示幼稚的红细胞能直接进入外周血流中,嗜酸性粒细胞和嗜碱性粒细胞无论在血涂片上或超薄切片上均未见到。描述了上述各种血细胞在光镜和电镜观察下的形态和细微结构。血栓细胞体积最小,嗜中性粒细胞体积最大;淋巴细胞数目最多,嗜中性粒细胞数目最少。     

临床型乳房炎奶牛与健康奶牛嗜中性粒细胞差异蛋白质组的表达分析

嗜中性粒细胞是防止病原入侵的第一道防线,且已有研究表明嗜中性粒细胞在奶牛乳腺免疫中发挥着关键作用。文章运用双向凝胶电泳方法对临床型乳房炎奶牛与健康奶牛嗜中性粒细胞差异表达蛋白质组进行分析,成功获得分辨率较高、重复性较好的奶牛嗜中性粒细胞双向电泳凝胶图谱,并通过MALDI-TOF MS鉴定获得差异表达的蛋白质7种,主要涉及细胞代谢、氧化应激、炎症反应等相关蛋白通路。实验获得的临床型乳房炎奶牛与健康奶牛嗜中性粒细胞差异表达蛋白有望为今后奶牛乳房炎的抗病育种研究提供理论依据。     

乌龟外周血细胞的显微和超微结构

乌龟血细胞的显微和超微结构研究表明;在外周血细胞中,可分辨出红细胞、单核细胞、淋巴细胞、血栓细胞、嗜酸性粒细胞、嗜碱性粒细胞、嗜中性粒细胞等7种细胞.红细胞核圆形,胞质均匀无细胞器.单核细胞的特征是核内异染色质多聚集于周边,胞质中含有许多囊泡.淋巴细胞的核质比例大.血栓细胞以具细长的指状突起,基本无细胞器为其特征.嗜酸性粒细胞仅含一种圆形颗粒,颗粒质地均匀,电子致密,大小不等.嗜碱性粒细胞颗粒环绕在胞核周围,有三种电子密度、颗粒大小不一的类型.嗜中性粒细胞含有两种电子密度、形态不一的颗粒.       

嗜中性粒细胞的高尔基体极性研究

用四氧化锇浸染技术研究了嗜中性粒细胞发育过程中高尔基体的极性变化。结果表明,在大鼠嗜中性粒细胞发育过程中,高尔基体的超微结构与嗜锇反应有着一系列的变化。从原粒细胞到分叶核粒细胞,不仅高尔基体的形状与大小有变化,而且高尔基体的极性也在不断变化。呈嗜锇反应的高尔基体生成面并不总是位于凸面,因此不能单凭高尔基体的形状(凹面与凸面)来鉴别高尔基体的极性。嗜中性粒细胞高尔基体的主要功能是产生两种不同的细胞质颗粒,即嗜天青颗粒与特殊颗粒。嗜天青颗粒产生于早幼粒细胞阶段,从高尔基体的成熟面形成,这一阶段的高尔基体成熟面是凹面。特殊颗粒产生于中幼粒细胞阶段,也是从高尔基体的成熟面形成,但这一阶段的高尔基体成熟面是凹面。尽管早幼粒细胞高尔基体的凹凸面与中幼粒细胞相反,但两种颗粒都是从高尔基体的成熟面分泌出来的,与其他分泌细胞形成分泌颗粒的方式相同。     

淡水石斑外周血细胞显微结构观察

淡水石斑(Cichlasoma managuense)外周血细胞可区分出红血细胞、嗜中性粒细胞、嗜酸性粒细胞、单核细胞、淋巴细胞和血栓细胞,未发现嗜碱性粒细胞。外周血液中还存在少量未成熟的和正在分裂的红血细胞。白细胞中,血栓细胞体积最小,嗜中性粒细胞体积最大;数量上,血栓细胞最多,而嗜酸性粒细胞则最少。     

Reproductive barriers between the partially sympatric Colorado and false potato beetles

The partially sympatric Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), and the false potato beetle (FPB), Leptinotarsa juncta (Germar), were shown to possess a series of reproductive barriers that protect species integrity. A strongly stereotyped sequence of courtship behaviour insures that more than 85% of encounters between these congeneric species are terminated before copulation. The courtship behaviour of the FPB, described here for the first time, is similar to that for the CPB. However, the male FPB is more likely to walk off the female FPB and will repeat antennal tapping more frequently than the CPB before moving on to palp tapping and mating. Observations suggest that both species first use antennal tapping for an initial olfactory assessment of the object as a female insect of a given family or species and palp tapping for final sex recognition. If courtship behaviour fails to break up the hybridization pairs, there is no mechanical barrier to mating and sperm transfer takes place. However, there is gametic mortality. The FPB is more fecund than the CPB and seems less dependent than the CPB on multiple matings to reach its full reproductive potential.     

The Pla surface protease/adhesin of Yersinia pestis mediates bacterial invasion into human endothelial cells

Oxidation of low density lipoprotein (LDL) induced by hypochlorous acid (HOCl) leading to LDL(-), a minimally oxidized subspecies of LDL, was investigated. LDL(-) is characterized by its greater electronegativity and oxidative status, and is found in plasma in vivo. Its concentration was found to be elevated under conditions that predispose humans to atherosclerosis. We found that HOCl also converts LDL rapidly to an even more oxidized state, identified as LDL(2-), which is more electronegative than LDL(-). After milder oxidation for short durations, formation of LDL(-) takes place while less LDL(2-) is formed. Under these conditions, addition of methionine not only suppressed further oxidation of LDL but also favored the formation of LDL(-) over LDL(2-), possibly by removing chloramines at lysyl residues of LDL. The presence of lipoprotein-deficient plasma did not prevent HOCl-mediated conversion of LDL to more electronegative species. It is concluded that the HOCl-mediated conversion of LDL into more electronegative species might be physiologically relevant.     

Cytotoxicity induced by nivalenol, deoxynivalenol, and fumonisin B1 in the SF-9 insect cell line

The toxicity of the mycotoxins nivalenol (NIV), deoxynivalenol (DON), and fumonisin B1 (FB1) was studied in the lepidopteran Spodoptera frugiperda (SF-9) cells, by the trypan blue dye-exclusion and 3-(4,5-dimethylthiozole-2-yl)-2,5-biphenyl tetrazolium bromide (MTT) tests, uptake analyses of cytotoxicity, and cell metabolism, respectively. Deoxyribonucleic acid analysis by flow cytometry was used to identify apoptosis and cell cycle distribution. After 48 h of exposure, the MTT and trypan blue dye-exclusion tests indicated that NIV was significantly more toxic than DON, and both were significantly more toxic than FB1. The IC50 (mycotoxin concentration resulting in 50% inhibition of proliferation) values for NIV and DON were 4.5 and 41 microM, and the CC50 (mycotoxin concentration that caused 50% cytotoxicity) values were 9.5 and 45 microM, respectively. At the highest concentration of FB1 (100 microM), there was 80% viability. With the same incubation time, cell cycle distribution showed an arrest of cells in the G0/G1 phase in the presence of NIV (up to 0.3 microM), DON (up to 3 microM), and FB1 (up to 10 microM). Morphological evidence of apoptosis was related to the toxicity of the substances in that the more toxic NIV induced late apoptosis, whereas DON and FB1 produced less-severe morphological changes characteristic of early apoptosis. This study suggests that NIV is more toxic than DON, which in turn is more toxic than FB1. These mycotoxins can modify the normal progression of the cell cycle and induce an apoptotic process.     

Prion proteins with insertion mutations have altered N-terminal conformation and increased ligand binding activity and are more susceptible to oxidative attack

We compared the biochemical properties of a wild type recombinant normal human cellular prion protein, rPrP(c), with a recombinant mutant human prion protein that has three additional octapeptide repeats, rPrP(8OR). Monoclonal antibodies that are specific for the N terminus of rPrP(c) react much better with rPrP(8OR) than rPrP(c), suggesting that the N terminus of rPrP(8OR) is more exposed and hence more available for antibody binding. The N terminus of PrP(c) contains a glycosaminoglycan binding motif. Accordingly, rPrP(8OR) also binds more glycosaminoglycan than rPrP(c). In addition, the divalent cation copper modulates the conformations of rPrP(c) and rPrP(8OR) differently. When compared with rPrP(c), rPrP(8OR) is also more susceptible to oxidative damage. Furthermore, the abnormalities associated with rPrP(8OR) are recapitulated, but even more profoundly, in another insertion mutant, which has five extra octapeptide repeats, rPrP(10OR). Therefore, insertion mutants appear to share common features, and the degree of abnormality is proportional to the number of insertions. Any of these anomalies may contribute to the pathogenesis of inherited human prion disease.     

Synthesis and antiproliferative evaluation of certain 4-anilino-8-methoxy-2-phenylquinoline and 4-anilino-8-hydroxy-2-phenylquinoline derivatives

The present report describes the synthesis and antiproliferative evaluation of certain 4-anilino-8-methoxy-2-phenylquinoline and 4-anilino-8-hydroxy-2-phenylquinoline derivatives. The antiproliferative activity of 4'-COMe-substituted derivatives decreased in an order of 6-OMe (1, 3.89 microM) > 8-OMe (8, 10.47 microM) > 8-OH (9, 14.45 microM), indicating that the position of substitution at the quinoline ring is crucial. For 3'-COMe derivatives, the antiproliferative activity of 8-OH (11, 1.20 microM) is more potent than its 8-OMe counterpart (10, 8.91 microM), indicating that a H-bonding donating substituent is more favorable than that of a H-bonding accepting group. Comparison of 8-OH derivatives, the antiproliferative effect of COMe (11) is more potent than its oxime derivative (15a, 2.88 microM), which in turn is more potent than the methyloxime counterpart (15b, 5.50 microM). Compound 11 is especially active against the growth of certain solid cancer cells such as HCT-116 (colon cancer), MCF7, and MDA-MB-435 (breast cancer) with GI50 values of 0.07, <0.01, and <0.01 microM, respectively. Flow cytometric analyses revealed that growth inhibition by 11 and 15a was due to accumulation in S-phase. This result is interesting because 2-phenylquinolone derivatives have been reported to be antimitotic agents which induced cell cycle arrest in G2/M phase.     

野葛组织内抗氧化物质初步分析

分别测定了野葛根、茎、叶ＳＯＤ、ＣＡＴ、ＰＯＤ、ＧＳＨ、Ｐｘ、Ｖｃ抗氧化物质活性,其中叶组织中含量最高;测定可深远的性蛋白和可溶性糖含量。发现可溶蛋白叶中最高,但根中可溶性糖含量远远高于茎叶。实验表明,野葛叶中也含有丰富的抗氧化物质,值得进一步研究开发。     

Arsenic in the human food chain,biotransformation and toxicology – Review focusing on seafood arsenic

Fish and seafood are main contributors of arsenic (As) in the diet. The dominating arsenical is the organoarsenical arsenobetaine (AB), found particularly in finfish. Algae, blue mussels and other filter feeders contain less AB, but more arsenosugars and relatively more inorganic arsenic (iAs), whereas fatty fish contain more arsenolipids. Other compounds present in smaller amounts in seafood include trimethylarsine oxide (TMAO), trimethylarsoniopropionate (TMAP), dimethylarsenate (DMA), methylarsenate (MA) and sulfur-containing arsenicals. The toxic and carcinogenic arsenical iAs is biotransformed in humans and excreted in urine as the carcinogens dimethylarsinate (DMA) and methylarsonate (MA), producing reactive intermediates in the process. Less is known about the biotransformation of organoarsenicals, but new insight indicates that bioconversion of arsenosugars and arsenolipids in seafood results in urinary excretion of DMA, possibly also producing reactive trivalent arsenic intermediates. Recent findings also indicate that the pre-systematic metabolism by colon microbiota play an important role for human metabolism of arsenicals. Processing of seafood may also result in transformation of arsenicals.     

A semiparametric estimator of the bivariate distribution function for censored gap times

Let (T(1), T(2)) be gap times corresponding to two consecutive events, which are observed subject to random right-censoring. In this paper, a semiparametric estimator of the bivariate distribution function of (T(1), T(2)) and, more generally, of a functional E [φ(T(1),T(2))] is proposed. We assume that the probability of censoring for T(2) given the (possibly censored) gap times belongs to a parametric family of binary regression curves. We investigate the conditions under which the introduced estimator is consistent. We explore the finite sample behavior of the estimator and of its bootstrap standard error through simulations. The main conclusion of this paper is that the semiparametric estimator may be much more efficient than purely nonparametric methods. Real data illustration is included.     

Effect of nonenzymatic glycation on functional and structural properties of hemoglobin

HbA(1c), the major glycated hemoglobin increases proportionately with blood glucose concentration in diabetes mellitus. H(2)O(2) promotes more iron release from HbA(1c) than that from nonglycated hemoglobin, HbA(0). This free iron, acting as a Fenton reagent, might produce free radicals and degrade cell constituents. Here we demonstrate that in the presence of H(2)O(2), HbA(1c) degrades DNA and protein more efficiently than HbA(0). Formation of carbonyl content, an index of oxidative stress, is higher by HbA(1c). Compared to HbA(0), HbA(1c) is more rapidly autooxidized. Besides these functional changes, glycation also causes structural modifications of hemoglobin. This is demonstrated by reduced alpha-helix content, more surface accessible hydrophobic tryptophan residues, increased thermolability and weaker heme-globin linkage in HbA(1c) than in its nonglycated analog. The glycation-induced structural modification of hemoglobin may be associated with its functional modification leading to oxidative stress in diabetic patients.     

alpha-Cl-alpha-Br-phosphonoacetic acid is a potent and selective inhibitor of Na+/Pi cotransport across renal cortical brush border membrane

We found that alpha-Cl-alpha-Br-phosphonoacetate (ClBrPAA) is a competitive, solute-specific inhibitor of Na+/Pi cotransport across renal cortical brush border membrane. Inhibition by ClBrPAA (Ki = 62 microM) is more than three times more effective than inhibition by phosphonoformate (PFA), the most potent Na+/Pi cotransport inhibitor known to date, and 26 times more effective than the parent compound, phosphonoacetate (PAA). These observations indicate that substitution of bromine and chlorine atoms at the alpha-carbon of PAA greatly enhances its efficacy as a competitive inhibitor of Na+/Pi cotransport. As ClBrPAA is much less inhibitory than PAA and PFA towards viral DNA polymerases and did not inhibit human alpha-DNA polymerase (ref. 10), the results also demonstrate that Na+/Pi cotransport inhibition can be dissociated from inhibition of DNA polymerases by phosphonocarboxylate compounds.