不同日龄的旋毛虫成虫感染小白鼠的实验研究

实验结果显示,每只小鼠由200条3日龄旋毛虫成虫感染的20只小鼠的肠内成虫数值范围6—57条,肌肉内幼虫数值范围17—33条。7日龄成虫感染的20只小鼠的肠内成虫数值范围2—34条,肌肉内幼虫数值范围2—55条。15日龄成虫感染的20只小鼠的肠内成虫数值范围0—8条,肌肉内幼虫数值范围0—3条。30日龄成虫感染的20只小鼠的肠内和肌肉内无成虫和幼虫所见。     

旋毛虫肌肉囊包内幼虫数量和囊包形态演化的观察

旋毛虫是一种人兽共患的寄生虫病，我国普遍存在，黑龙江省是重要流行区。旋毛虫成虫寄生于宿主的消化系统，幼虫寄生于肌肉系统，可导致包括人体在内的多种哺乳动物宿主感染旋毛虫病。一般认为，肌肉内囊包幼虫数目1～2条，多则6～7条，肌肉内幼虫囊包沿肌纤维平行走行呈梭形。     

旋毛虫病

旋毛虫病是人畜共患的重要寄生虫病之一,其病原属同一种,即旋毛虫[Trichinella Spiralis],亦称旋毛形线虫。其属鞭虫目,毛线科,最早发现于伦敦的一例尸检中。成虫(肠旋毛虫)寄生于小肠,幼虫(肌旋毛虫)寄生于同一宿主的横纹肌内。     

旋毛虫肌肉期幼虫分泌排泄物中46-58KD抗原的保护性免疫作用

目的研究旋毛虫肌肉期幼虫分泌排泄物(TsL1-ES)中46-58KD抗原诱发小鼠的保护性免疫能力。方法用该纯化抗原组分加福氏完全佐剂(FCA)腹腔注射免疫昆明小鼠3次,继以旋毛虫感染性幼虫300条攻击感染,感染后第7天计数小鼠肠道成虫数,第30天肌肉幼虫数和血清抗体IgG滴度。结果46-58KD抗原免疫鼠的肠道成虫减虫率、肌肉幼虫减虫率和血清抗体IgG的几何平均倒数滴度(GMRT)分别为46·4%、46·1%和2841·2,与TsL1-ES诱导的保护性免疫力(48·3%、50·2%和3458·6)水平接近,显著高于佐剂对照组(4·8%、8·2%和748·6)。结论TsL1-ES中46-58KD抗原组分可产生明显的保护性免疫作用。     

大蒜汁对旋毛虫幼虫杀灭效果研究

目的通过比较经不同浓度大蒜汁浸泡含旋毛虫肌幼虫的肉块对小鼠感染力的影响,来评估大蒜汁对旋毛虫幼虫的杀灭效果。方法 30只昆明小鼠分为5组,喂食经不同浓度的大蒜汁(浓度分别为100.00%、50.00%、25.00%、12.50%)和生理盐水浸泡半小时含有旋毛虫肌幼虫的肉,饲喂30d后剖杀小鼠,观察和计数肌幼虫数。结果小鼠饲喂经100.00%、50.00%、25.00%、12.50%浓度大蒜汁和生理盐水浸泡半小时含有旋毛虫肌幼虫的肉后,在单位肌肉中检出旋毛虫肌幼虫数为0条、10条、60条、140条和235条。结论含旋毛虫肌幼虫的肉经一定浓度的大蒜汁浸泡后其旋毛虫肌幼虫的感染力会降低。     

活体旋毛虫保种浅析

目的建立标准化活体旋毛虫种保存技术,为教学和科研服务。方法将感染40d旋毛虫的大白鼠取躯体肌肉用捣碎机将肌肉绞碎,按要求比例加入消化液,于39C温箱中消化16～18h。然后将消化液反复洗涤沉淀,收集旋毛虫肌幼虫。结果在解剖镜下观察旋毛虫幼虫虫体卷曲的白环形态。结论用消化法进行的旋毛虫活体保种效果好,可永久传存下去。     

香肠腌制法对旋毛虫感染性影响的实验研究

目的观察香肠腌制法对旋毛虫肌幼虫感染性的影响。方法30只昆明小鼠被随机分为对照组和实验组,实验组又分5组,共6组,每组5只。对照组每鼠经口感染300条收集的肌幼虫。实验组分5组,4℃,阳性鼠肉香肠配料分别腌制24、48、72、96、120h,然后将5组小鼠每鼠经口感染300条处理好的肌幼虫。感染后28d处死小鼠,取膈肌压片镜检,并将全部肌肉人工消化后计数幼虫数。结果24h组、48h组、72h组、96h组压片法和人工消化法镜检,感染小鼠的幼虫检出率均为100％;4组的幼虫均数均显著低于对照组（P〈0．01）;48h组、72h组、96h组的幼虫均数均显著低于24h组（P〈0．01）。120h组两种方法镜检,感染小鼠均未检出幼虫。结论使用香肠腌制法腌制肉类,随着腌制时间的延长,肉内旋毛虫幼虫的活性和感染性逐渐下降。     

寄生虫学讲座(8) 旋毛形线虫(旋毛虫)

旋毛虫成虫寄生在人体小肠,幼虫主要寄生在人体的肌肉内。本虫所致的旋毛虫病对人体危害很大,严重感染能致人死亡。1 形态1.1 成虫:虫体细小线状,前端较后端细,咽管结构特殊,长度约占虫体1/3,后段咽管的背侧面为单层的杆     

丙硫咪唑驱蛲虫成虫和杀虫卵作用的观察

丙硫咪唑经临床应用证明抗蛲虫效果较佳。为确切了解该药驱成虫和杀虫卵作用,我们选择蛲虫病人实验,现报告结果如下。 1 对象和方法:选择10名4～7岁儿童蛲虫感染者,投200～400mg丙硫咪唑,一次顿服。治疗后1～4天分别以水洗粪便淘虫计数确定驱成虫作用,以透明胶纸粘取儿童肛周虫卵,行人工消化液孵化,24h内观察幼虫的孵出确定杀虫卵作用。 2 结果与讨论:①驱成虫作用:治疗后第一天,收集7名儿童粪便,平均获得成虫1.4条,最多3条,最少0条。总计10条。治疗后第二天,收集6名儿童粪便,平均     

国内近十年来旋毛虫病的临床研究

旋毛虫病（Trichinosis）是由旋毛线虫感染引起的人鲁共患病。1928年Pedcock首次在尸检肌肉中发现囊包内幼虫期旋毛虫，1835年Owen描述了虫体形态并命名。本病呈世界性分布，人体感染与饮食习惯密切相关。一、临床流行病学我国1881年从猪体内发现旋毛虫，但直至1965年有黄风池报告在西藏发现旋毛虫病1例。截目前止，发现旋毛虫病例的已有云南、西藏、辽宁、吉林、黑龙江、河北、河南、四｝！；、广东、广西等十多个省启治区及香港特区。现已知我国十余省散发、集体暴发病例达2万人以上，死亡至少200余例。综观各地临床病例发病特点，均有…     

Response of ADA and its isoenzymes in mice infected by Trichinella spiralis and treated with mimosine

Infections caused by the nematode Trichinella spiralis (T. spiralis) are characterized by an inflammatory response in the host. The aim of this study was to identify and evaluate markers for monitoring mice infected with T. spiralis and treated with or without mimosine. The markers that have been used were total and differential white blood cell counts, subpopulations of lymphocytes, serum tADA and its isoenzymes ADA1 and ADA2 activity. The study included 3 groups of BALB/c mice. Group A consisted of 16 healthy mice, Group B of 16 mice infected with T. spiralis and treated with saline, and Group C of 16 mice infected with T. spiralis and treated with mimosine. The measurements were made once per week for the first six weeks continuously following the infection. According to our results, leukocytosis, lymphocytosis and increased percentages of adhesion molecules and CD4 lymphocytes were present in groups B and C one week post-infection. Total ADA activity as well as ADA1 and ADA2 was higher in groups B and C versus group A from the first week post-infection. The levels of tADA activity, ADA1 and ADA2 were higher in group B compared to those of group C and the difference was statistically significant (p<0.05) during the 4th week post-infection. The majority of tADA activity, essential for an efficient immune response, was derived from ADA1 which may have been produced by infected tissues. The elevated activities of tADA and ADA1 may be sensitive markers for infection of T. spiralis and for monitoring the course of the infection.     

Microcapsules formulated in the enteric coating copolymer Eudragit L100 as delivery systems for oral vaccination against infections by gastrointestinal nematode parasites

Microcapsules using the copolymer of methacrylic acid (Eudragit L100) were formulated for oral delivery of vaccines against the enteral/parenteral nematode parasite Trichinella spiralis. Antigenic preparations from first stage larvae (L1) of T. spiralis were microencapsulated in Eudragit L100. The microcapsules prepared by the spray drying method were resistant to acid pH, although the antigen was rapidly released under neutral and basic environmental conditions. The native protein conformation and biological activity was preserved in the microcapsules, as assessed by SDS-PAGE and ELISA. When administered to NIH mice, the antigen loaded microcapsules protected against infection by T. spiralis at both the intestinal and muscular levels, the worm burden diminishing by 45.58 and 53.33%, respectively. Furthermore, following administration of the microparticles an increase of the serum IgG1 response, a marker for the Th2 type response, was evident. These results indicate that microcapsules formulated with anionic biocompatible polymers such as Eudragit may be useful for oral vaccination against nematode infections.     

Host resistance to Trichinella spiralis infection in rats and mice: species-dependent effects of cyclophosphamide exposure.

Host resistance to Trichinella spiralis infection was compared in male rats (F344) and female mice (C57BL/6J) following various cyclophosphamide (CY) treatment schedules. Doses of CY given to mice were adjusted by body surface area to be comparable to rat doses. Adult parasite elimination was not affected by oral administration of 1.5, 3 or 6 mg CY/kg per day to rats or 1.05, 2.1 or 4.2 mg CY/kg per day to mice for 10 days. In rats, resistance was suppressed by a single oral dose of 80 mg/kg given the day prior to infection, but was not affected at 20 or 40 mg/kg. A single oral dose of 14, 28 or 56 mg CY/kg did not affect parasite expulsion in mice. Rats were also given four daily intraperitoneal (i.p.) injections of 20, 40 or 80 mg CY/kg per day and mice received 14, 28 or 56 mg CY/kg per day. Infected rats did not survive at the two higher dose levels and parasite expulsion was suppressed at 20 mg/kg per day; parasite expulsion was suppressed in mice by four i.p. injections of 56 mg CY/kg per day, but not by lower doses. In rats, doses of CY which suppressed adult parasite expulsion also severely suppressed the proliferative response of mesenteric lymph node cells (MLNC) to an extract of T. spiralis (TsE). However, significant suppression of TsE-driven blastogenesis occurred at a dose of CY which did not affect parasite expulsion, indicating that the proliferative response in rats was more sensitive to suppression than actual parasite elimination. In contrast, the proliferative response to the T cell mitogen concanavalin A was elevated in the MLNC of CY-exposed rats. This was determined to be related to the interval between CY dosing and the day of assay rather than to an effect of infection with T. spiralis. Mouse MLNC proliferative responses to TsE were not suppressed by CY treatment, even at levels of CY which suppressed adult parasite expulsion. Mice differed from rats in that CY exposure did not affect the proliferative response to concanavalin A in infected animals. The species-dependent differences observed in these studies may have been secondary to the greater sensitivity of rats to CY. Nonetheless, these results highlight the potential for species-specific responses to chemical exposure and underscore the need for additional comparative studies of host resistance in rats and mice.     

Microarray analysis of NF-kappaB signaling pathways in PBMC of mice infected by Trichinella spiralis

The NF-kappaΒ pathway gene expression profiles were compared between 10, 20 and 39 days after Trichinella spiralis experimental infection in BALB/c mice. Out of 128 genes, 19 (14.8%) genes were present in non-infected and post-infected mice. The expression of 7 (36.8%) genes was downregulated 10 and 20 days post-infection while 3 (15.8%) genes were upregulated 39 days post-infection. The present study lists the candidate genes of the NF-kappaB signaling pathway that were commonly and differentially expressed between the specific points of T. spiralis infection, thus suggesting that these genes need to be further investigated to reveal the mechanism of the T. spiralis modulation of the NF-kappaB signaling pathways.     

Abnormal thymus development and impaired function of the immune system in rats after prenatal exposure to aciclovir

Aciclovir (synonym: acyclovir) causes abnormal thymus development in rats. After treatment on day 10 of gestation a weight reduction of the organ is obvious in 21-day-old fetuses which persists postnatally. Adult male rats exposed in utero to one or three injections of 100 mg aciclovir/kg body wt given to the dam on day 10 of pregnancy showed a reduction of the thymus weight to 333±158 mg and 276±61 mg (control: 428±92 mg;n=10). Corresponding alterations were detectable in female offspring. Liver weight was also decreased and spleen weight (in relation to body wt) was significantly increased in the offspring after the three exposures. In a host resistance model withTrichinella spiralis the function of the immune system of rats prenatally exposed to aciclovir was examined. Six weeks postnatally 10–12 randomly selected male rat offspring of one control and two treatment groups (1 or 3 injections of 100 mg aciclovir/kg body wt on day 10 of gestation) were infected orally with 500Trichinella spiralis muscle larvae. Before and several times after the infection blood was taken from a tail vein or obtained by decapitation for examination of the antibody titers (IgM, IgG, IgA, IgE) to antigens ofT. spiralis. Six weeks after the infection the weight of relevant organs was determined and tongue preparations were used forT. spiralis muscle larvae counting. Aciclovir exposed animals showed a different immune response than control rats. IgM titers in both treatment groups werehigher than in controls two weeks after the infection but not different by the end of the experiment. The IgG and IgE titers in the high dose group werelower than in the other groups at the end of the observation period. IgA antibody titers in the high dose group were alsolower than controls, but only 2 weeks after the infection. The number ofT. spiralis muscle larvae in tongue preparations was higher in the 3×100 mg aciclovir group than in the low dose group or in controls. Our results indicate that morphological thymus alterations and functional deficits of the immune system can be induced by prenatal exposure of rats to aciclovir on day 10 of gestation.     

Microcapsules formulated in the enteric coating copolymer Eudragit L100 as delivery systems for oral vaccination against infections by gastrointestinal nematode parasites

Microcapsules using the copolymer of methacrylic acid (Eudragit L100) were formulated for oral delivery of vaccines against the enteral/parenteral nematode parasite Trichinella spiralis. Antigenic preparations from first stage larvae (L1) of T. spiralis were microencapsulated in Eudragit L100. The microcapsules prepared by the spray drying method were resistant to acid pH, although the antigen was rapidly released under neutral and basic environmental conditions. The native protein conformation and biological activity was preserved in the microcapsules, as assessed by SDS-PAGE and ELISA. When administered to NIH mice, the antigen loaded microcapsules protected against infection by T. spiralis at both the intestinal and muscular levels, the worm burden diminishing by 45.58 and 53.33%, respectively. Furthermore, following administration of the microparticles an increase of the serum IgG1 response, a marker for the Th2 type response, was evident. These results indicate that microcapsules formulated with anionic biocompatible polymers such as Eudragit may be useful for oral vaccination against nematode infections.     

Toxicity of bis(tri-n-butyltin)oxide in the rat. II. Suppression of thymus-dependent immune responses and of parameters of nonspecific resistance after short-term exposure

To evaluate the functional significance of bis(tri-n-butyltin)oxide (TBTO)-induced thymus atrophy, lymphocyte depletion in spleen and lymph nodes, lymphopenia, and increased serum IgM and decreased IgG concentrations, in vivo and in vitro function studies were performed for specific and nonspecific resistance. Weaned male rats were fed diets containing 0, 20, or 80 mg TBTO/kg for at least 6 weeks. Regarding the thymus-dependent immunity, delayed-type hypersensitivity reactions to ovalbumin as well as tuberculin were significantly depressed at both dietary concentrations. Resistance to the nematode Trichinella spiralis was significantly suppressed as shown by a retarded expulsion of adult worms from the small intestine, increased counts of muscle larvae, reduced inflammatory reaction in parasitized musculature, and suppressed serum IgE titers. Also the secondary mercaptoethanol-resistant (presumably IgG) hemagglutinating antibody titer to sheep red blood cells was significantly reduced, while no significant alterations were found in IgM and IgG titers to T. spiralis, ovalbumin, and tetanus toxoid. TBTO exposure reduced the response of thymocytes in both treatment groups and of spleen cells in the 80-mg/kg group upon stimulation with T-cell mitogens and increased the response of spleen cells to B-cell mitogens. When calculated per whole spleen, the response to T-cell mitogens was strongly impaired but unaltered by B-cell mitogens. This difference can be explained by a relative increase of splenic B cells as a result of reduced numbers of T cells, as shown by cell surface marker analysis using monoclonal antibodies. Reduced splenic T-cell numbers appeared equally due to a decreased number of T helper and to T suppressor cells. From these data and from results of a time-sequence study in which effects of TBTO on cell count and cell viability of thymus, spleen, and bone marrow were investigated, it is concluded that TBTO-induced immunodeficiency was primarily due to its direct toxic action on thymocytes. When cultured in vitro in the presence of TBTO, viability of thymus and bone marrow cells was equally reduced, while after in vivo treatment viability of bone marrow cells was unaffected. Thus, the in vitro situation does not mimic the in vivo one. Concerning the nonspecific resistance, TBTO reduced macrophage function as shown by impaired splenic clearance of Listeria monocytogenes bacteria. From in vitro studies it is concluded that impaired in vivo splenic clearance was due to a reduction in both the number of adherent cells in the spleen and bacterial digestion on a cell for cell basis.(ABSTRACT TRUNCATED AT 400 WORDS)