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。     

嗜吞噬细胞无形体致病机理的研究进展

嗜吞噬细胞无形体是一种侵染中性粒细胞专性细胞内寄生的革兰阴性菌,其所致疾病为人粒细胞无形体病（HGA）,是一种经蜱传播的人兽共患病。它感染中性粒细胞后可诱发机体产生炎症免疫反应,最终导致免疫抑制及潜在疾病引起的各种继发感染和器官衰竭,甚至危及生命。近年来该病原体日益受到人们的关注和重视。就嗜吞噬细胞无形体致病机理研究的进展进行了综述。     

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。     

嗜中性粒细胞是人抵抗素表达的主要细胞

抵抗素(resistin)是小鼠白色脂肪组织大量表达的富含半胱氨酸的 分泌型蛋白.近年研究发现,人与啮齿类动物的抵抗素组织表达分布存在很 大差异．小鼠抵抗素主要在白色脂肪组织表达,而人抵抗素主要在单核细 胞/巨噬细胞表达,且在骨髓组织中大量表达,但目前骨髓中的细胞定位还 不清楚．本研究的目的是明确成人骨髓及外周血白细胞中抵抗素表达细胞 的类型．免疫荧光法检测骨髓中抵抗素表达细胞,结果显示,抵抗素主要表 达在细胞核呈杆状和分叶核状的成熟粒细胞中,其中杆状核粒细胞表达较 高,分叶核粒细胞表达减弱．Anti-hresistin IgG-Biotin-PE单色荧光流 式细胞术分选外周血白细胞中抵抗素表达细胞后经瑞氏化学染色,结果显 示,抵抗素表达细胞主要为杆状和分叶核状的嗜中性粒细胞,还有少量嗜酸 性粒细胞,且抵抗素蛋白分布在细胞质中. RT-qPCR结果在RNA水平上证明, 人抵抗素在嗜中性粒细胞中大量表达．Anti-hresistin IgG-FITC和anti- HNL IgG-Biotin-PE 双色荧光流式细胞术进一步证明,抵抗素的主要表达细 胞为成熟的嗜中性粒细胞．嗜中性粒细胞在机体免疫防御中起重要作用, 人骨髓及外周血中抵抗素主要在成熟嗜中性粒细胞中表达,这一研究结论 为人抵抗素与炎症反应的关联性及其功能的进一步研究奠定了基础.     

四环素类抗生素降解途径及其主要降解产物研究进展

四环素类抗生素在生产和贮存过程中会发生一系列非生物降解反应,其中某些代谢及降解产物,与母体相比,虽然其活性降低,但毒性却大大增强.此类抗生素随着畜禽废弃物等途径进入到环境中,随环境条件的不同将发生一种或多种降解反应,其降解方式除了非生物降解外,还包括生物降解.本文综述了四环素类抗生素在不同生态环境中的降解途径以及降解产物,并对今后的研究方向进行了探计,旨在为其生态风险评价提供有价值的参考.     

人粒细胞-巨噬细胞集落刺激因子研究进展

hGM-CSF是一种重要的具有免疫调节功能的糖蛋白,在造血调控和免疫调节方面发挥重要作用,具有重要的临床应用价值。总结近些年来各国对hGM-CSF的研究情况,首先对hGM-CSF的基因结构、蛋白分子结构、生物学活性等方面做了详细的介绍;接下来,又从基因转录水平和转录后水平两个方面对hGM-CSF的表达调控做了介绍;最后,对比了利用基因工程技术将hGM-CSF基因在不同生物中的表达情况,详细讲解了优缺点。     

重组人粒细胞集落刺激因子的纯化

重组人粒细胞集落刺激因子（ｒｈＧ－ＣＳＦ）在工程菌ｐＣＧ－１／ｒｈＧ－ＣＳＦ／ＤＨ５ａ中以无活性的包涵体形式大量表达。经过菌体破碎分离包涵体、包涵体变性复性后,ｒｈＧ－ＣＳＦ的活性得到恢复。用离子交换和疏水层析纯化了ｒｈＧ－ＣＳＦ,比活性达１．５７×１０８ｕ／ｍｇ,纯度大于９８％。     

重组人粒细胞集落刺激因子的复性研究

通过小试研究对重组人粒细胞集落刺激因子(rhG-CSF)的复性条件,如氧化剂和还原剂比例、操作方法、时间和蛋白浓度,进行了优化选择,并在此基础上进行了中试放大试验的验证.试验结果表明,采用优化后的复性方法复性液中rhG-CSF的效价可达到1.8×107U/ml以上,比活性达到0.9×108/mg以上.     

不同介质中四环素类抗生素的检出水平与污染扩散

四环素类抗生素由于其抗菌效率高、应用范围广、价格低廉等特点,被广泛应用于临床医学、畜牧业和养殖业等领域。特别是超量使用以及不当处理,使其在水体、土壤和大气等环境介质中残留、富集并发生迁移转化,进而污染环境,危及生态系统甚至人类健康。因此,了解其在环境中的检出水平以及污染扩散情况尤为重要。虽然这类抗生素在污染介质中的检出水平多为痕量,但在不同的介质中检出频率较高。四环素类抗生素在各种环境介质中的污染扩散均表现出迁移率高、扩散易发生且范围广等特点。文章对不同介质中抗生素的痕量检测、多污染物的复合污染以及抗生素的抗药性等方面的研究进行了展望。     

Diversity of rickettsial pathogens in Columbian black‐tailed deer and their associated keds (Diptera: Hippoboscidae) and ticks (Acari: Ixodidae)

Cervids host multiple species of ixodid ticks, other ectoparasites, and a variety of rickettsiae. However, diagnostic test cross‐reactivity has precluded understanding the specific role of deer in rickettsial ecology. In our survey of 128 Columbian black‐tailed deer (Odocoileus hemionus columbianus (Richardson)) and their arthropod parasites from two northern Californian herds, combined with reports from the literature, we identified four distinct Anaplasma spp. and one Ehrlichia species. Two keds, Lipoptena depressa (Say) and Neolipoptena ferrisi Bequaert, and two ixodid ticks, Ixodes pacificus Cooley and Kohls and Dermacentor occidentalis Marx, were removed from deer. One D. occidentalis was PCR‐positive for E. chaffeensis; because it was also PCR‐positive for Anaplasma sp., this is an Anaplasma/Ehrlichia co‐infection prevalence of 4.3%. 29% of L. depressa, 23% of D. occidentalis, and 14% of deer were PCR‐positive for Anaplasma spp. DNA sequencing confirmed A. bovis and A. ovis infections in D. occidentalis, A. odocoilei in deer and keds, and Anaplasma phagocytophilum strain WI‐1 in keds and deer. This is the first report of Anaplasma spp. in a North America deer ked, and begs the question whether L. depressa may be a competent vector of Anaplasma spp. or merely acquire such bacteria while feeding on rickettsemic deer.     

Detection of Borrelia burgdorferi and Anaplasma phagocytophilum in the black‐legged tick,Ixodes scapularis,within southwestern Pennsylvania

Prevalence studies of Borrelia burgdorferi and Anaplasma phagocytophilum have been rare for ticks from southwestern Pennsylvania. We collected 325 Ixodes scapularis ticks between 2011 and 2012 from four counties in southwestern Pennsylvania. We tested for the presence of Borrelia burgdorferi and Anaplasma phagocytophilum using PCR. Of the ticks collected from Pennsylvania, B. burgdorferi (causative agent of Lyme disease) was present in 114/325 (35%) and Anaplasma phagocytophilum (causative agent of Human Granulocytic Anaplasmosis) was present in 48/325 (15%) as determined by PCR analysis.     

Anaplasma phagocytophilum in small mammals and ticks in northeast Florida

Human anaplasmosis is an emerging tick-borne disease in the United States, but few studies of the causative agent, Anaplasma phagocytophilum, have been conducted in southeastern states. The aim of this study was to determine if A. phagocytophilum is present in small mammals and ticks in northeast Florida. Polymerase chain reaction assays designed to amplify portions of the major surface protein 2 gene (p44), 16S rDNA, and groESL operons were used to test rodent blood and tick DNA samples for the presence of A. phagocytophilum. Positive samples were confirmed by DNA sequence analysis. Anaplasma phagocytophilum DNA was detected in less than 5% of cotton mice and 45% of cotton rats from two sites in northeast Florida. Anaplasma phagocytophilum DNA was also confirmed in 1.3% of host-seeking adult Ixodes scapularis tested and 2.7% of host-seeking adult Amblyomma americanum. This report describes the first DNA sequence data confirming strains of A. phagocytophilum in rodents and ticks in Florida. The DNA sequences of the msp2, 16S rDNA, and groESL gene fragments obtained in this study were highly similar to reference strains of human pathogenic strains of A. phagocytophilum. These findings suggest that A. phagocytophilum is present and established among some small mammal species in northeast Florida. Although the infection prevalence was low in the total number of ticks tested, the presence of A. phagocytophilum in two human biting tick species, one of which is a known competent vector, suggests that humans in this region may be at risk of granulocytic anaplasmosis caused by this pathogen.     

Detection of Lyme disease and anaplasmosis pathogens via PCR in Pennsylvania deer ked

Borrelia burgdorferi and Anaplasma phagocytophilum are obligate intracellular parasites that maintain their life cycles in enzoonotic vector‐host cycles with Ixodes scapularis as a vector. In addition to ticks, the hosts are commonly infested with insects from the Hippoboscidae family. This study confirms the presence of B. burgdorferi and A. phagocytophilum in deer keds (Lipoptena cervi) removed from white‐tailed deer using PCR. Detection of these pathogens in deer ked represents a potential novel susceptibility of wildlife and also suggests the risk of transmission of these pathogens to humans and animals alike through the bite of an infected ectoparasite. This study represents the first instance in the U.S. of detection of tick‐borne pathogens in a member of the Hippoboscid family.     

Expression of heat shock proteins and subolesin affects stress responses, Anaplasma phagocytophilum infection and questing behaviour in the tick, Ixodes scapularis

We characterized the effects of subolesin and heat shock protein (HSP) expression on Ixodes scapularis Say (Acari: Ixodidae) stress responses to heat shock and feeding, questing behaviour and Anaplasma phagocytophilum (Rickettsiales: Anaplasmataceae) infection. Ticks and cultured tick cells were analysed before and after subolesin, hsp20 and hsp70 gene knock-down by RNA interference. The results of these studies confirm that HSPs are involved in the tick cell response to heat stress and that subolesin and HSPs are both involved in the tick response to blood-feeding stress and A. phagocytophilum infection. Subolesin and hsp20 are involved in the tick protective response to A. phagocytophilum infection and hsp70 expression may be manipulated by the pathogen to increase infectivity. Importantly, these results demonstrate that subolesin, hsp20 and hsp70 expression also affect tick questing behaviour. Overall, this research demonstrates a relationship between hsp and subolesin expression and tick stress responses to heat shock and blood feeding, A. phagocytophilum infection and questing behaviour, thereby extending our understanding of the tick-host-pathogen interface.     

青少年慢性粒细胞白血病急变临床分析

目的:分析青少年慢性粒细胞白血病(CGL)急变患者临床表现及实验检查特点,以提高对青少年CGL急变临床特点的认识。方法:将CGL急变患者按年龄分组,将青少年组和中老年组患者的急变时间、确诊时和急变时的脾脏大小、白细胞和血小板数目、急变时骨髓幼稚细胞的比例,以及患者的总生存时间、急变后生存时间进行对比分析。结果:青少年组和中老年组的脾脏大小、确诊时血小板数目、急变时的白细胞数目、急变时间、以及总生存时间无显著性差异;青少年组确诊时的白细胞数目较中老年组高,青少年组的急变后生存时间较长。结论:青少年CGL患者的临床表现及实验室检查结果具有CGL的普遍特征,但其确诊时白细胞数目较高,急变后生存时间较长。