Host tissue invasion by Entamoeba histolytica is powered by motility and phagocytosis

During amebiasis, E. histolytica motility is a key factor to achieve its progression across tissues. The pathogenicity of E. histolytica includes its capacity to phagocyte human cells. Motility requires polarization of E. histolytica that involves protrusion of a pseudopod containing actin and associated proteins [myosin IB, ABP-120 and a p21-activated kinase (PAK)] and whole-cell propulsion after contraction of the rear of the cell, where myosin II and F-actin are concentrated. An interesting characteristic of this parasite is the presence of two unique myosins (myosin II and unconventional myosin IB), in contrast to several actin genes. Little is known about the regulation of the actin-myosin cytoskeleton dynamics of E. histolytica, and a better understanding of signaling pathways that stimulate and coordinate regulators protein and cytoskeleton elements will provide new insight into the cell biology of the parasite and in amebiasis. Here we summarize the pleiotropic functions described for myosin II and PAK in E. histolytica. We propose that survival and pathogenicity of E. histolytica require an active actin-myosin cytoskeleton to cap surface receptors, to adhere to host components, to migrate through tissues, to phagocyte human cells and to form liver abscesses.     

骨髓炎动物模型的研究进展

骨髓炎是由于感染引起的骨及其相关组织的急性或慢性炎症。该病具有治疗困难、花费高、病程迁延不愈、致残率高等特点。由于骨髓炎发病过程非常复杂、变异度高,目前有多种动物模型应用于骨髓炎的发病机制、诊断和治疗的研究。建立骨髓炎模型的动物常使用兔、大鼠和小鼠,较少使用狗、猪、山羊等大型动物。然而,目前研究中尚未发现可以较好控制的动物模型。本研究通过检索目前骨髓炎动物模型的建立方法,以期寻求一种可以较好控制的用于研究骨髓炎发生、发展的动物模型,并对目前骨髓炎研究进展进行展望。     

The cytoskeleton of Entamoeba histolytica: structure, function, and regulation by signaling pathways

Pathogenesis in the parasite Entamoeba histolytica has been related to motility of the trophozoites. Motility is an important feature in amebas as they perform multiple motile functions during invasion of host tissues. As motility depends on the organization and regulation of the cytoskeleton elements, in particular of the actin cytoskeleton, the study of the molecular components of the machinery responsible for movement has been a key aspect to study in this parasite. Although many of the components have high homology in amino acid sequence and function to those characterized in higher eukaryotic cells, there are important differences to suggest that parasitic organisms may have developed adaptative differences that could be useful as targets to stop invasion. The purpose of this review is to evaluate current knowledge about the cytoskeleton of E. histolytica and the ways in which the parasite controls motility.     

结构生物学在溶组织内阿米巴致病机制研究中的应用

溶组织内阿米巴（Entamoeba histolytica,Eh）是寄生于人类肠道的原生动物,可引起阿米巴性结肠炎和肠外脓肿。结构生物学在原子水平上研究生命大分子结构和功能,是一种重要的生物学研究方法,经过半个多世纪的理论和技术发展,已应用于生物学和基础医学的各个研究领域。本文综述了目前结构生物学的研究技术,并以阿米巴穿孔素A和半胱氨酸蛋白酶抑制剂为例介绍结构生物学在Eh致病机制研究中的应用,总结了今后结构生物学在Eh研究领域可能的应用方向和研究热点。     

发热伴血小板减少综合征病毒动物感染及动物模型

发热伴血小板减少综合征病毒（severe fever with thrombocytopenia syndrome virus,SFTSV）是我国2009年发现的一种新型布尼亚病毒。蜱虫是其重要储存宿主及传播媒介,野生动物和家畜均存在自然感染。α/β干扰素受体基因敲除的免疫缺陷小鼠是理想的实验动物模型。本文综述了SFTSV的动物感染及动物模型的研究成果,为SFTSV自然流行的控制以及动物实验提供依据。     

Toxocariasis--an unlikely cause of Palm Island mystery disease

After the suggestion was made that the "Palm Island mystery disease" might have been an epidemic of visceral larva migrans that was caused by the flying fox parasite, Toxocara pteropodis, work was undertaken to elucidate this nematode's life-cycle and pathogenicity. Studies of infections in various laboratory animals have shown unexpectedly variable susceptibility patterns, with mice harbouring most larvae for the longest time period. However, in all susceptible animals (which include mice, guinea-pigs and suckling rats), the larvae demonstrated marked hepatotropism. Experimental infections in monkeys demonstrated that primates are susceptible to this infection, but large doses of 20,000 infective eggs produced blood eosinophilia and focal granulomatous hepatitis without clinical disease or biochemical abnormalities in the blood. It is concluded that humans are susceptible to larval infections with this nematode, but that clinical manifestations would be unlikely to develop.     

无形体属立克次体宿主动物和传播媒介的研究进展

无形体属立克次体种类繁多,现已发现无形体属中的几个种对人类和动物致病。近年来,世界范围内新发及再发无形体病逐年上升,对人类和家畜健康造成重大威胁。为更好的了解病原体的保存和传播方式,国内外已对其宿主动物和传播媒介进行了大量的研究。本文就无形体属中确定的几个种的宿主动物和传播媒介作一综述。     

上海地区实验动物病原体感染指数分析

目的 为了更直观的了解实验动物质量控制情况,本文引“感染指数”这一评估指标。探索测算感染指数的最佳方法,以便更加科学的反映实验动物的感染状况。方法 感染指数,也称感染度,它是对实验动物质量监测的定性指标。通过加工汇总实验动物的病原体感染率,综合反映某一特定实验动物群体的病原体感染状态或趋势的一种指标。结果 总体上,小鼠病原体感染指数呈逐年下降的趋势,而大鼠的病原体感染指数则逐年上升。分别比较各类病原体感染指数发现,小鼠中寄生虫感染指数最高,而大鼠中细菌感染指数最高。结论 感染指数分析揭示了实验动物质量的基本状况,需要加强对小鼠寄生虫的监测,而大鼠的细菌检测需要投入更多关注。小鼠病原体感染情况得到控制,大鼠各类病原体的控制情况均逐年趋于严重。     

实验动物低温生物学和生殖工程技术的发展与应用

低温生物学(cryobiology)是生物科学的一门新兴分支学科,他是研究低温对生物体所产生的影响及其应用的科学。低温生物学的研究和应用,不仅促进了生物学、医学等基础学科的发展,而且为农业、畜牧业、医药工业及其食品工业等带来了巨大的效益。特别是对保护人类赖以生存的环境,挽救濒危物种,保护生物多样性产生了深远的影响。实验动物是生命科学的重要支撑条件,近年来,实验动物新品系,尤其是小鼠突变系的飞速增加已对现有的动物设施和资源的保存方法提出严峻的挑战。随着低温生物学理论的不断深入及其技术的不断完善,低温生物学技术已被广泛应用于实验动物的生产、遗传资源的保存及新品系开发等领域。无疑,小鼠模型的保存将为21世纪哺乳类遗传学的飞速发展和最终攻克人类目前的疑难疾病创造了有利条件。     

性宝口服液的抗疲劳功能动物实验研究

目的考察性宝口服液的缓解体力疲劳的功能。方法根据卫生部《保健食品检验与评价技术规范》2003版中缓解体力疲劳功能检验方法进行性宝口服液的动物实验，将昆明小鼠按体重随机分成对照组、性宝口服液低剂量组、中剂量组、高剂量组和男宝胶囊组，分别给予等体积蒸馏水、性宝口服液1、2、6mL/kg及男宝胶囊0.9g/kg，ig30d，测定小鼠负重游泳时间、肝糖原含量、血清尿素氮和血乳酸曲线下面积。结果性宝口服液ig30d后，对小鼠体重无明显影响，能显著延长KM小鼠负重游泳时间（p〈0.05）；能显著增加小鼠肝糖元含量（p〈0.01）；能显著降低小鼠血清尿素氮含量（p〈0.05、p〈0.01）。结论性宝口服液具有缓解体力疲劳的功能。     

C5a/C5aR通路在硕大利什曼原虫易感小鼠免疫病理发生中的作用及其机制

目的研究C5a/C5aR通路在对硕大利什曼原虫(Leishmania major,L.major)易感的BALB/c小鼠免疫病理发生中的作用及机制探讨。方法以C5aR KO小鼠(BALB/c背景)为模型,观察比较了WT和C5aR KO的BALB/c小鼠在L.major感染后的病变情况,有限稀释法检测了各组感染小鼠体内寄生虫的负荷,并进一步通过FACS检测了相关细胞因子如IL-17和IL-4的产生,来探讨C5a/C5aR通路在L.major易感型BALB/c小鼠免疫病理发生中的作用机制。结果相比WT小鼠,C5aRKO小鼠感染L.major后的病变程度明显减轻(P<0.05),体内寄生虫负荷也显著降低(6.952±0.398vs 4.340±0.434,P<0.01);同时,FACS胞内染色结果表明CD4+IL-4+T细胞亚群百分比显著降低(0.960 0±0.148 3 vs0.314 0±0.042 6,P<0.01),但CD3+IL-17+T细胞亚群的百分比在两组之间无显著差异(0.792 0±0.051 3 vs 0.858 0±0.084 5,P=0.522 3)。结论 C5a/C5aR通路通过调节Th2细胞关键细胞因子IL-4的产生,在L.major易感小鼠的免疫病理发生中发挥作用。     

赤子爱胜蚓纤溶酶的药理性质探讨

用赤子爱胜蚓提取物给小鼠口服,观察其有无毒副作用及抗血栓作用,同时进行了血液凝血时间及纤溶活性的测定,结果表明:赤子爱胜蚓提取物小鼠口服后有极为明显的抗栓作用及增强纤溶活性的效应(P<0.01),优球蛋白溶解时间也有缩短。口服赤子爱胜蚓提取物具有毒副作用小,使用方便的特点,有进一步开展临床研究与应用的价值。     

转基因动物在肥厚型心肌病研究中的应用

肥厚型心肌病(hypertrophic cardiomyopathy,HCM)是一种常染色体显性遗传心肌病,通常表现为室间隔非对称性肥厚,伴或不伴有流出道的明显梗阻.普通人群的患病率为1:500[1].约有50%的肥厚型心肌病患者有家族史,男女比例2:1,平均发病年龄为(38±15)岁.本病常为青年(特别是运动员)猝死的原因,且无特效治疗手段[2].     

吡罗昔康擦剂的抗炎镇痛作用

动物实验结果表明１％吡罗昔康对角叉莱胶和佐剂所致大鼠急慢性足跖肿胀和炎症足压痛，以及对醋酸所致小鼠扭体反应，均具有明显抑制作用，故提示１％吡罗昔康擦剂是一种多种动物模型具有抗炎，镇痛作用的新型制剂。     

小动物活体可见光成像技术在医学研究中的应用

小动物活体光学成像技术是生物及医学研究领域的一项新兴技术。随着该技术的发展,小动物活体成像在临床前研究中发挥着越来越重要的作用。本文简要综述了活体动物体内可见光成像技术的原理、应用领域及其特点。     

Human PET/CT scanners: feasibility for oncological in vivo imaging in mice

PET/CT imaging is a highly valuable oncological imaging modality. The combination of positron emission tomography (PET) and computed tomography (CT) provides the ability to accurately register molecular and metabolic aspects of cancers with anatomical and morphological findings in human clinical routine examinations and for animals in vivo research. Small animal models of mice are widely used in biomedical research for mimicking and studying the human nature, because of their genetic resemblance and the feasibility of gene transfer and gene modification. The recent generation of high performance human PET/CT scanners combines a state of the art full-ring 3D PET scanner and a high-end 16-slice CT scanner (biograph Sensation 16, Siemens AG, Erlangen, Germany). Small animals can be examined with special scanning and reconstruction protocols. The examination of tumor-bearing small animals using a modern human PET/CT revealed excellent image quality. CT can be performed with a maximum spatial resolution of 0.6 x 0.6 x 0.6 mm and PET with a maximum spatial resolution of 6.3 x 6.3 x 6.0 mm. The examination of tumor-bearing small animals using human PET/CT allowed accurate correlation and evaluation of metabolic and anatomical information and is promising for in vivo research purposes. Although image quality is limited by spatial resolution, human PET/CT is widely available and expected to contribute significantly to research with small animal imaging. The investigation of cancer in small animals with PET/CT is probably one of the most challenging tasks in nuclear medicine for the evaluation of tumor growth and growth inhibition factors; development of new anti-tumor drugs and measuring of anti-tumor effects; and cancer treatment response of immunotherapy, chemotherapy and radiation therapy.     

骨痛灵软膏抗炎作用的药理学研究

1.　吉林大学第一医院康复疼痛诊疗中心,吉林 长春 130021;2. 吉林大学体育学院人体生物科学教研室,吉林 长春 130012;3. 吉林大学药学院药理教研室,吉林 长春 130021;     

痤疮模型的研究现状

痤疮由于发病机制复杂,针对不同的发病机制采用的实验模型也不同。目前的实验模型主要包括在体动物模型和体外模型。在体实验动物模型主要包括兔耳模型、金黄地鼠模型、犀鼠模型、墨西哥无毛犬模型。体外模型主要是集中在表皮角质细胞培养和皮脂腺细胞培养。本文旨在对近几年的实验研究方法进行归纳,以利于在实际应用中选择适合的动物模型,为今后筛选防治痤疮的药物研究提供良好的实验平台。     

不同宿主感染肉孢子虫的分子生物学研究进展

肉孢子虫是一种人畜共患寄生虫,其形态学鉴定及血清学检测均不理想。分子生物学技术的应用,极大地促进了肉孢子虫的虫种鉴定及中间宿主、终宿主的研究。各种肉孢子虫有相对较高的宿主特异性,本文以宿主为线索,对近年来应用PCR及相关技术在人、马、猪、牛、羊、鸟类等不同宿主感染肉孢子虫的发现及应用进行了综述。     

Diagnosis of amebiasis in Bangladesh

Diagnosis of amebiasis by microscopic identification of the parasite in stool and liver abscess pus is insensitive and unable to distinguish the invasive parasite E. histolytica from the commensal parasites such as E. dispar and E. moshkovskii. New approaches to the detection of E. histolytica are based on detection of E. histolytica-specific antigen and DNA in stool and other clinical samples. Several molecular diagnostic tests for diagnosis of amebiasis have been developed and used to diagnose E. histolytica in Bangladesh. We have compared the TechLab E. histolytica-specific antigen detection test with PCR assays and with isoenzyme analysis of cultured amebas. The PCR assays are based on amplification of the multi-copy small subunit ribosomal RNA gene of E. histolytica and E. dispar. PCR assays and antigen detection test had comparable sensitivities when performed directly on fresh stool specimens. The correlation of antigen detection with PCR assays for identification of E. histolytica was excellent. TechLab's E. histolytica- specific antigen detection test was both rapid and simple to perform, making it appropriate for use in the developing world, where amebiasis is most prevalent.