猪的锥虫病研究

江苏省盱眙县发生母猪锥虫病两例,一例未经治疗死亡,另一例以钠格诺尔治愈。由此分离到锥虫一株,为单型锥虫,波动膜及游离鞭毛均很明显,动基体靠近虫体后端。虫体长度为19.4～26.3微米,平均为22.9微米,宽度为1.3～2.2微米,平均为1.6微米。先后试验感染小白鼠53只,均于4—7天内死亡;兔5只于30—34天內死亡;犬3只于6～17天内死亡;仔猪2头,一头于第41天死亡,另一头耐过。所有动物均发生虫血症。以牛的伊氏锥虫致敏绵羊红细胞与本锥虫感染猪的血清可产生凝集反应;反之以猪的锥虫与已知牛的伊氏锥虫的阳性血清亦可产生团集反应。作者根据上述特点,和国外已报道于猪的8种锥虫进行了比较,认为属于伊氏雉虫。为此,无论猪作为伊氏锥虫保虫宿主,还是伊氏锥虫对猪的致病作用均不能忽视。     

西北区骆驼锥虫和中南区马锥虫的比较研究(三)交叉免疫试验

以黄牛和猪各4头进行四次交叉免疫试验以比较西北区骆驼锥虫和中南区马锥虫的结果为:有两次试验说明有区别,一次试验说明略有区别,另一次试验说明无区别。关于西北区骆驼锥虫和中南区马锥虫的种别鉴定问题,在全部病原研究工作结束后再加以决定。     

秉志锥虫的重描述及其系统发育分析

为丰富鱼类锥虫的物种资源,了解养殖鱼类锥虫的感染情况,通过调查湖北地区鱼类锥虫的感染情况,在武汉市江夏区牛山湖渔场养殖的鲫血液中分离到一种锥虫,并采用形态学和分子生物学数据对该锥虫进行描述。通过形态特征和衍征的比较与分析,发现该锥虫与秉志锥虫(Trypanosoma pingi)形态一致,故鉴定为秉志锥虫。扩增并获得秉志锥虫的18SrDNA分子序列,通过序列比对分析,发现其与黄颡锥虫(Trypanosoma pseudobagri)18SrDNA序列相似性最高,为94.62%,分子系统发育树分析显示秉志锥虫落于淡水鱼类锥虫支类,与黄颡锥虫(Trypanosoma pseudobagri)形成姊妹群。     

西北区骆驼锥虫和中南区马锥虫的比较研究总结

讨论和摘要(一)显微镜下观察并量度的结果;西北区骆驼锥虫和中南马锥虫形态上大致相同。它们和国外报告的 Trypanosoma evansi(Steel,1885)及 Trypanosoma ninae Kohl-jakimovi yakimoff,1918形态上没有显著差别。西北区骆驼锥虫接种犬体120代后的锥虫,发现形态上和原来的相比,变动不显著。(二)经过人工感染证明西北区骆驼锥虫和中南区马锥虫都能感染骆驼。马、驴、牛、     

用间接血凝试验检查乳牛和水牛的泰氏锥虫感染

以水牛泰氏锥虫细胞培养的虫体裂解抗原,致敏双醛化绵羊红细胞,用以检查乳牛和水牛的泰氏锥虫感染,不仅特异性强,敏感性也很高,且与伊氏锥虫无交叉反应,是一种简易快速而又可靠的实验室诊断方法。本法较外周血液虫体培养检出率高32—36％。用本法随机检查乳牛1168头,阳性581头,阳性率49.74％;水牛395头,阳性168头,阳性率42.5％。在伊氏锥虫疫区的水牛,用二种间接血凝方法检测,部分牛表现伊氏锥虫和泰氏锥虫均为阳性,表明水牛可同时感染这二种锥虫。本文还讨论了泰氏锥虫感染同乳牛白血病、盱眙水牛病可能存在某种联系,以及泰氏锥虫有可能致病等问题。     

西北区骆驼锥虫和中南区马锥虫的比较研究(一)形态学

1.显微镜下观察并量度西北区骆驼锥虫100个后发现和外国的 Tryonosoma evansi 及T.ninae kohI—jekimovi 形态上没有显著差别。2.显微镜下量度西北区骆驼锥虫1000个的长度发现双 Bruce(1911)所量的 T.evansi 82个虫体的结果,体长较短的略多一些,但总的说来差异不大。3.显微镜下观察并量度100个西北区骆驼锥虫接种大体129代后的锥虫,发现形态上和原来的相比变动不显著。4.显微镜下观察并量度中南区马锥虫100个发现和西北区骆驼锥虫形态上大致相同。5.关于西北区骆驼锥虫和中南区马锥虫的学名鉴定,待今后结合其它方面的病原研究结束后再行决定。     

从牛白血病淋巴细胞培养分离出一株泰氏锥虫的研究

从4头确诊为白血病的病牛淋巴细胞培养和3头淋巴肉瘤牛的肿瘤组织培养中,分离到5株非致病性锥虫,其形态和培养特性完全一致,表明为同一种锥虫。本锥虫在细胞培养上生长良好,能连续继代,并呈现一定的生长曲线和生活史阶段。通常在接种后1—4天为对数生长期,主要为锥虫鞭毛虫期锥虫,形态较一致,后端尖细,动基体偏近核,有游离的长鞭毛;5天至6天进入平衡期,这一时期除锥虫鞭毛虫期虫体外,还出现许多形态不规则的虫体(包括短胖型和蝌蚪型等),并往往聚集成团,它们可能是核上鞭毛虫期锥虫;第7天后进入衰老期,虫体溶解消失。在培养末期细胞层上出现很多球状的无鞭毛虫期(利什曼型)虫体,大部粘附在细胞间隙,在部分细胞浆内亦可见有此种利什曼型虫体。 本锥虫虽较泰氏锥为虫小,培养要求也较高,但从形态特征、生活史和生物学特性看,应可鉴定为泰氏锥虫。     

Samorin抗伊氏锥虫的效果观察

沙莫灵(Samorin)是英国生产的一种抗锥虫药,对刚果锥虫、活跃锥虫、布氏锥虫均有良好的抗虫活性,至于对伊氏锥虫是否具有抗虫活性,国内未见报道。本试验仅在观察沙莫灵对小鼠伊氏锥虫病的效果,为临床治疗试验提供依据。现将试验结果报告如下:一、沙莫灵 由香港利农有限公司提供。化学名为8(间——脒苯重氮氨基)——3——氨基——5——乙基——6——氯化苯菲啶盐酸盐,简称“脒氯苯菲啶”,其主要成分     

伊氏锥虫不同株的表面变异糖蛋白分离、纯化及特性比较

锥虫的抗原变异非常频繁,阻碍了免疫学防治技术的建立,国内外虽然对此有较多研究报告,但对中国不同地理、宿主株伊氏锥虫表面变异糖蛋白(VSG)分离和特性比较尚无报道,而我国北方新疆骆驼株伊氏锥虫和南方牛、马伊氏锥虫存在来源、地理、宿主和生化特性的差异,因此我们对这两个虫株的 VSG 进行了分离、纯化和特性比较研究,所用虫株来源于新疆骆驼体内、安徽水牛体内.分离后克隆为单一虫株,经小白鼠、大白鼠体内繁殖,鼠血经过 DEAE-52纤维素层析获得纯净锥虫,再经超声裂解,经过两次超速     

西北区骆驼锥虫和中南区马锥虫的比较研究(四)免疫血清试验及总结

体内试验锥虫等原生动物可以引起宿主产生免疫性,这在本研究交叉免疫试验内已经表明。慢性锥虫病动物,或痊愈后甚止治愈后的锥虫病动物的血清如果和同种锥虫同时注射另一动物,那血清就有“保护作用”保护后者使其在不同程度上抵抗锥虫的感染;或者完全不感染,或者感染后,(?)维持生命较久。Rouget(1896)最早发现被致病的马(?)疫锥虫 Tryp-     

四种药物对路氏锥虫的体外杀灭效果试验

观察硝唑尼特、贝尼尔、咪唑苯脲、Trypan等4种药物在不同浓度、不同作用时间对路氏锥虫的体外杀灭效果。将这4种药物分别以5、10、20、40、80mg/ml的浓度作用于体外培养路氏锥虫,在第24h和48h观察杀灭效果。试验结果:4种药物对路氏锥虫都有杀灭效果,药效依次为硝唑尼特>贝尼尔>Trypan>咪唑苯脲,药物对路氏锥虫的杀灭率随着药物浓度增加和作用时间的延长而增高。硝唑尼特具有较强的杀灭作用,效果较好。     

Light-enhanced free radical formation and trypanocidal action of gentian violet (crystal violet)

Transmission of Chagas' disease by transfusion of blood containing Trypanosoma cruzi has often been reported, and gentian violet, a triarylmethane dye, is widely used by blood banks in attempts to eliminate such transmission. In a study of intact trypanosomes, gentian violet was found to undergo a one-electron reduction to produce a carbon-centered free radical as demonstrated by electron spin resonance spectroscopy. Either reduced nicotinamide adenine dinucleotide or the reduced dinucleotide phosphate could serve as a source of reducing equivalents for the production of this free radical by homogenates of Trypanosoma cruzi. The formation of this free radical, and the trypanocidal action of gentian violet, were enhanced by light. The enhanced free radical formation may be the basic cause of the selective toxicity of gentian violet to Trypanosoma cruzi.     

Polyamine metabolism: a potential therapeutic target in trypanosomes

alpha-Difluoromethylornithine (RMI 71,782), a specific irreversible inhibitor of the first step in polyamine biosynthesis, that is, the formation of putrescine from ornithine by ornithine decarboxylase, cures mice infected with a virulent, rodent-passaged strain of Trypanosoma brucei brucei. This parasite is closely related to the trypanosomes that cause human sleeping sickness. The drug, which is remarkably nontoxic, was effective when administered in drinking water or by intubation. The ability of the compound to inhibit ornithine decarboxylase in vitro was demonstrated by the reduced amounts of putrescine synthesized from tritiated ornithine in Trypanosoma brucei suspensions. These observations direct attention to polyamine metabolism as a target for chemotherapy of parasitic diseases.     

Comparative genomics of trypanosomatid parasitic protozoa

A comparison of gene content and genome architecture of Trypanosoma brucei, Trypanosoma cruzi, and Leishmania major, three related pathogens with different life cycles and disease pathology, revealed a conserved core proteome of about 6200 genes in large syntenic polycistronic gene clusters. Many species-specific genes, especially large surface antigen families, occur at nonsyntenic chromosome-internal and subtelomeric regions. Retroelements, structural RNAs, and gene family expansion are often associated with syntenic discontinuities that-along with gene divergence, acquisition and loss, and rearrangement within the syntenic regions-have shaped the genomes of each parasite. Contrary to recent reports, our analyses reveal no evidence that these species are descended from an ancestor that contained a photosynthetic endosymbiont.     

Identification and isolation of a variant surface glycoprotein from Trypanosoma vivax

The protozoan Trypanosoma vivax is one of the most important agents of African trypanosomiasis, a disease that hinders the productive use of livestock in one-third of the African continent. Trypanosoma vivax is also present in the Caribbean and in South America, posing a threat to the livestock industries of the tropical and subtropical world. Much less is known of the biology of this trypanosome than of the better studied T. brucei and T. congolense. One of the variant surface glycoproteins (VSGs) of a West African stock of T. vivax was identified, purified, and partially characterized by the use of a combination of highly resolving techniques to maximize information from the relatively small amount of parasite material available. The molecular weight of the isolated protein (46,000) is smaller than that of VSGs from other species. As with T. brucei VSGs the protein from T. vivax is complexed with sugars and incorporates 3H when living trypanosomes are incubated with [3H]myristic acid, but the T. vivax molecule is more hydrophobic than the T. brucei molecule. The small size of the T. vivax VSG may have a bearing on the functional and evolutionary relationships of variant antigens in trypanosomes.     

Inhibitory action of gossypol on enzymes and growth of Trypanosoma cruzi

Gossypol, a phenolic compound isolated from the cotton plant, is a powerful inhibitor of nicotinamide adenine dinucleotide-linked enzymes (alpha-hydroxyacid dehydrogenase and malate dehydrogenase) of Trypanosoma cruzi, the parasite that causes Chagas' disease. Parasites at the epimastigote stage that were incubated for 5 minutes with 100 micromolar gossypol were completely immobilized. Concentrations of gossypol as low as 0.01 micromolar markedly reduced the growth rate of T. cruzi in culture.     

African trypanosomes: cultivation of animal-infective Trypanosoma brucei in vitro

Trypanosoma brucei grew in the presence of bovine fibroblast-like cells in Hepes-buffered RPMI 1640 medium with 20 percent fetal bovine serum for more than 220 days at 37 degrees C. The organisms grown in this system were infective to mammalian hosts, retained the morphological and biochemical characteristics of long slender bloodstream forms, and displayed variant-antigen on their surfaces.     

Large microtubule-associated protein of T. brucei has tandemly repeated, near-identical sequences

The parasitic protozoon Trypanosoma brucei contains a highly organized membrane skeleton, consisting of a dense array of parallel, singlet microtubules that are laterally interconnected and that are also in tight contact with the overlying cell membrane. A high molecular weight, heat-stable protein from this membrane skeleton was isolated that is localized along the microtubules. Protease digestion experiments and sequencing of a cloned gene segment showed that most of the protein is built up by more than 50 nearly identical tandem repeats with a periodicity of 38 amino acids.