泡球蚴在小鼠体内发育过程的组织学观察

泡球蚴病(Alveococcosis,又称多房棘球蚴病)是一种严重危害人体健康的寄生虫病。在我国流行于甘肃、宁夏、新疆、青海及四川西部等地区。病原为多房棘球绦虫(Echinococcus multilocularis Leuckart,1863),并已先后在四川野犬(朱依柏等,1983)与宁夏红狐(李维新等,1983)肠内查到成虫。1984年8月,作者又在四川甘孜县大塘坝区剖杀野犬16只,其中4只查到多房棘球绦虫,除1犬仅发现7条成虫外,其余3只均达数千条。为了解本病发生过程,探索化疗药物筛选与疗效考核指标,作者等取成虫孕卵节片口饲感染小鼠,建立了动物模型。本文报告泡球蚴在小鼠肝内由…     

内蒙古呼伦贝尔草原多房棘球蚴病病原的调查

本文报道在内蒙古呼伦贝尔草原主体部分四个牧业旗的草场进行多房棘球蚴病病原调查的结果。发现布氏田鼠(Microtus brandti)及长爪沙鼠(Meriones unguicutatus)是本绦虫的中间宿主、沙狐(Vulpes corsac)是其终末宿主。布氏田鼠是本绦虫中间宿主新记录,长爪沙鼠和沙狐分别是国内本绦虫中间宿主和终宿主新记录。布氏田鼠是呼伦贝尔草原的优势啮齿类,其平均感染率为2.43％(64/2635),越冬成鼠感染率高达5.23％—14.29％(平均6.66％)。长爪沙鼠感染率虽达16.67％(1/6),但鼠数不多。沙狐是本草原常见的食肉兽,检查6只沙狐,其中2只(33.3％)肠内含多房棘球绦虫成虫无数。用其孕节饲喂实验室小白鼠6只,6个月后检查各实验鼠,肝脏均布满泡状多房棘球蚴。呼伦贝尔草原本绦虫成虫及原头节形态特征均与我国西北本虫种差异显著,而与苏联及美国阿拉斯加的多房棘球绦虫西伯利亚亚种比较相似。     

地塞米松对泡球蚴在小鼠体内发育的影响

据文献报告,在寄生虫感染动物模型研究中使用皮质类激素可提高宿主对原虫(How-ard,1984)与多种蠕虫(Rayetal,1975;Hashiguchietal,1977;杨超等,1982)的易感性,并能加速寄生虫生长发育过程。参照前人方法,作者观察泡球蚴(Alveolarechino-coccus)在长期肌注地塞米松的小鼠体内发育情况与宿主免疫反应。实验结果显示小鼠免疫力受到明显抑制,虫囊增重快,原头蚴生成率提高。现报告如下。材料与方法一、实验动物雌性昆明种小鼠,体重18—22克。以两种方式接种:取多房棘球绦虫孕卵节片35—40节直接灌鼠胃引起肝脏原发感染;切取小鼠泡球蚴组织块0.2…     

灰仓鼠多房棘球蚴腹腔动物模型的建立

目的观察多房棘球蚴(Echinococcus muhilocularis E.m)在灰仓鼠腹腔内的生长发育规律,制作E.m灰仓鼠动物模型。方法 2000个E.m原头节/只剂量腹腔接种灰仓鼠,接种后10、15、18、22、39、60、80和100 d,测量包囊重量和抗体,计算包囊重与灰仓鼠体重的包囊系数,观察多房棘球蚴在灰仓鼠体内的发育规律。分别按100个/只、500个/只和2000个/只剂量腹腔接种灰仓鼠各10只,100 d后剖检比较不同感染剂量的包囊发育情况和感染率。结果 62只灰仓鼠中有59只感染了多房棘球蚴。18 d可观察到成熟原头节,感染率达到100%,15 d出现抗体阳性,60 d时包囊系数达到15%以上;100、500和2000三种剂量的感染率100%;结论建立的灰仓鼠腹腔多房棘球蚴动物模型具有感染率高,感染周期短,包囊生长发育和抗体滴度变化易观察,感染60 d可作为E.m动物模型成模观察期。包囊系数,抗体滴度和包囊发育变化可作为造模的主要参考指标。雌性灰仓鼠造模优于雄性。     

周期型马来丝虫实验感染小白鼠体内发育的观察

本实验用长爪沙鼠体内周期型马来丝虫微丝蚴,感染东乡伊蚊收集感染期幼虫,经腹腔内注射５５只小白鼠（昆明种）后,定期抽查小白鼠腹腔液和解剖小白鼠观察丝虫发育情况。在１４天、３０天、６０天、１４０天和１６０天时,分别检获了Ⅲ期、Ⅳ期幼虫、童虫和成虫。成虫感染率为３４．６％（９／２６）。９１天还查出微丝蚴。实验结果表明：周期型马来丝虫可以在昆明种小白鼠体内发育到成虫并产生微丝蚴。     

稻虱跗(虫扇)的个体发生研究:生活史和寄生作用

稻虱跗蝙Elenchinus japonicus Esaki et Hashimoto属(捻翅目)跗蝙科,在稻田寄生于白背稻虱、褐稻虱和灰稻虱。稻虱跗蝙在母体血腔中发育、孵化产生三爪蚴,三爪蚴通过生殖沟、生殖孔、育道和育道开口离开母体。三爪蚴离开母体在稻株上活动。一旦靠近寄主,用足抓住寄主,爬在它们身上。它通过节间膜进入寄主,变成蛆状蚴,开始取食。幼虫在寄主体内继续发育,达到足够大小,它们羽化成虫。雌成虫留在寄主体内,仅露出“帽子”(即头胸部),雄虫离开寄主,自由飞翔、雄成虫寿命很短(<12小时),它们积极寻找雌虫,进行交配,发现交配位置在育道口,支配时间约1—2秒钟。雄成虫体长1.33mm;展翅约2.25mm;雌成虫体长1.6—2.6mm,宽0.88—1.35mm;头胸部长0.2mm;育道口宽0.15mm,卵在雌成虫体内形成,而卵母细胞在雌幼虫体内发育。卵长75μm×宽40μm。第1期幼虫(三爪蚴):体长0.2mm;尾须为体长1/3。第Ⅱ期幼虫(蛆伏蚴)足和附肢都退化;第Ⅱ期幼虫分成4个龄期,具口和消化道,蛹属围蛹。卵历期7—8天,而三爪蚴历期仅1天。蛆状蚴(2—5龄)历期10—11天,蛹历期约3—4天,雌成虫历期7—8天。在实验室,每世代历期约20—23天。稻虱跗蝙的寄生作用较低,由于三爪蚴找不到稻虱很快死亡。在浙江1983—1986年调查,稻虱跗蝙对白背稻虱成、若虫寄生     

稻虱跗(虫扇)的个体发生研究:生活史和寄生作用

稻虱跗蝙Elenchinus japonicus Esaki et Hashimoto属(捻翅目)跗蝙科,在稻田寄生于白背稻虱、褐稻虱和灰稻虱.稻虱跗蝙在母体血腔中发育、孵化产生三爪蚴,三爪蚴通过生殖沟、生殖孔、育道和育道开口离开母体.三爪蚴离开母体在稻株上活动.一旦靠近寄主,用足抓住寄主,爬在它们身上.它通过节间膜进入寄主,变成蛆状蚴,开始取食.幼虫在寄主体内继续发育,达到足够大小,它们羽化成虫.雌成虫留在寄主体内,仅露出“帽子”(即头胸部),雄虫离开寄主,自由飞翔、雄成虫寿命很短(<12小时),它们积极寻找雌虫,进行交配,发现交配位置在育道口,支配时间约1—2秒钟.雄成虫体长1.33mm;展翅约2.25mm;雌成虫体长1.6—2.6mm,宽0.88—1.35mm;头胸部长0.2mm;育道口宽0.15mm,卵在雌成虫体内形成,而卵母细胞在雌幼虫体内发育.卵长75μm×宽40μm.第1期幼虫(三爪蚴):体长0.2mm;尾须为体长1/3.第Ⅱ期幼虫(蛆伏蚴)足和附肢都退化;第Ⅱ期幼虫分成4个龄期,具口和消化道,蛹属围蛹.卵历期7—8天,而三爪蚴历期仅1天.蛆状蚴(2—5龄)历期10—11天,蛹历期约3—4天,雌成虫历期7—8天.在实验室,每世代历期约20—23天.稻虱跗蝙的寄生作用较低,由于三爪蚴找不到稻虱很快死亡.在浙江1983—1986年调查,稻虱跗蝙对白背稻虱成、若虫寄生率5—7%,灰稻虱的寄生率为2%,褐稻虱为1%.有时白背稻虱的寄生率可达20—40%.     

马来丝虫幼虫低温保存的初步研究

以5％二甲基亚砜为冷冻保护剂,将马来丝虫微丝蚴置于含20％小牛血清的RPMI-1640保存液内,在低温下(-196℃)保存。经过30—270天,微丝蚴解冻后的存活率为93—98％,大部均可使蚊虫宿主感染,并在终宿主长爪沙鼠体内发育为成虫,在其腹腔液内检获微丝蚴。 同法冻存含马来丝虫感染期幼虫的蚊体,经30、90、及181天后,解冻的蚊体内幼虫,其存活率为46.2—54.4％,90天前大部幼虫可在沙鼠体内发育并产出子代,但冻存180天组似已失去感染性。     

结膜吸吮线虫在终宿主体内发育过程及生殖机能的实验观察

以结膜吸吮线虫的感染期蚴和当天自然感染犬眼的小童虫,植入实验动物限结膜囊内,经平行观察,证明发育到成虫产蚴所需最短时间为35—36天。除对感染期蚴进行大小测定和形态特征描述外,还对不同发育时间的虫体与相应的形态变化过程进行阐述。同时观察到本虫食管与体长比值随生长时间延长而逐渐变小的关系,以此为依据结合虫体其他特征,作为对终宿主眼内虫体寄生时间的估测指标,这对寄生于人眼的本虫鉴定和病史分析以确定感染时间都具有一定意义。本文还指出了该虫产蚴能力、生殖特点及本虫寿命等生理方面有关问题。     

两株近交小鼠对周期型马来丝虫的易感性

于长爪沙鼠体保种的周期型马来丝虫,其感染性幼虫(100条/只)接种于BALB/cCR和BALB/cJ两株小鼠腹腔内,都获得感染成功。在95只BALB/cCR株鼠(45,50)中,显性感染者8只(4,4),占8.42％;隐性感染者34只(17,17),占35.79％。共检获成虫110条,每鼠检获1—11条,平均2.62条。在30只BALB/cJ株鼠(18,12)中,12只雌鼠全部阴性;18只雄鼠中,2只为显性感染,4只为隐性感染,共检获成虫18条,每鼠检获1—5条,平均3.0条。两株小鼠中的10只显性感染鼠,有2只腹腔液内首次发现微丝蚴是在感染后80天,其最短潜隐期约为75天。     

Prevalence of Hydatid Cysts in Livestock Animals in Xinjiang,China

Hydatid worms, hosted by humans and animals, impose serious human health risk and cause significant livestock production loss. To better understand the disease infection status in Xinjiang, China, we investigated the disease epidemics in 4 livestock animals, i.e., cattle, sheep (both sheep and goat), camels, and horses, slaughtered at the abattoirs in Urumqi, Yining, Tacheng, and Altay areas. The results showed that the animals were infected at different rates, in the order of sheep (9.8%), cattle (8.4%), camels (6.8%), and horses (4.3%). The infection rates were found to be different between the abattoirs in various regions even for the same animals. For sheep, the rates increased significantly as the animals grew older. It was 1.9% before 1 year of age and increased to 8.2% in the age of 1-2 years, and further increased to 12.3% when the animals were 3-4 years old, and reached 17.2% when they were 5-6 year old. Sheep older than 6 years had an infection rate of 19.5%. This study demonstrates that the 4 livestock animals in the pastoral areas in Xinjiang were infected by the parasites to various extend. This study is the first systematic investigation of the hydatid worms in various livestock animals in Xinjiang, China, which provides epidemiological information about the infection of hydatid worms in livestock, and is valuable in developing strategies for prevention and control of the hydatid disease.     

Epidemiological and histomorphic studies in sheep infected with hydatid cyst in Taif area

Hydatidosis is a zoonotic disease caused by Echinococcus granulosus larvae, which affects sheep worldwide, especially in rural communities. This study aims to determine the prevalence and structure of hydatid cyst in sheep. A total number of 1,198 sheep in different age groups G1 (<1 year), G2 (1–2 years) and G3 (>2 years) were slaughtered at Taif abattoirs, then examined for the presence of hydatid cysts in lung, liver, and mesentery. Prevalence of hydatid cyst infection in imported sheep (13.0%) was higher than of local sheep (10.2%). Particularly, as per gender, prevalence of imported females (71.9%) was higher than those of local females (28.1%), while that of imported males (66.3%) was higher than those of local males (33.7%). Large sizes of hydatid cysts and fertility recorded in G3 were higher in both local and imported sheep than those of G1 and G2. Morphometric analysis of pathological lesions in liver of all infected sheep showed a significant increase compared to non-infected healthy sheep (have no lesions) (P < 0.001). In addition, for all infected sheep, histochemical investigation with Masson’s trichrome stain showed collagen fibers inside the hydatid cyst capsules and in pericystic region. The collagen fibers content and the cellular laminated membranes took the green color, while immunohistochemical evaluation detected a positive reaction for CD3.     

Prevalence of Echinococcosis in Reindeer (Rangifer Tarandus) in Sweden

In Sweden echinococcosis is uncommon in domestic animals. In reindeer in the most northern part of the country echinococcosis was found. Of 1453 pairs of lungs, 23 pairs (1.6 %) were infected with hydatid cysts. These were of two types: typical well-developed hydatid cysts, which were found in nine of the 23 infected lungs, and collapsed hydatid cysts, which were found in 13 of the lungs. In only one lung pair both types of cysts were seen.     

Hydatidosis in Sardinia. Co-involved parameters and hypothesis for a control campaign

Although hydatidosis provokes in man and livestock losses of economic significance, there has been no comprehensive study on this disease. This article is an account of Sardinia as an important area of echinococcosis-hydatidosis. The incidence and distribution of infection in the intermediate and definitive hosts are reviewed and the current status of hydatid disease is evaluated. The review is divided into main sections: (a) geographical and environmental data; (b) domestic intermediate hosts; (c) definitive host; (d) human infections. An average of 85% of the sheep are infected and about 75% of cysts are fertile, 13% of the dogs are parasitized and mainly live as strays, up to 39% of the shepherd's dogs were found to harbour the mature worm of Echinococcus granulosus. Hospital data indicate that even nowadays about 200 people are operated every year with an incidence of 11.1/100.000 inhabitants. The socio-cultural factors (seminomadism, slaughtering practice, etc.) involved in the dissemination, the economic implication of this disease, the benefits due to an eradication, the feasibility of a campaign and the organizational structure aimed at eradicating echinococcosis/hydatidosis in this area, are discussed.     

Effect of Echinococcus multilocularis on the origin of acetyl-coA entering the tricarboxylic acid cycle in host liver

Carbon-13 nuclear magnetic resonance (NMR) spectroscopy was employed to investigate alterations in hepatic carbohydrate metabolism in Meriones unguiculatus infected with Echinococcus multilocularis. Following portal vein injections of an equimolar mixture of [1,2-13C2]acetate and [3-13C]lactate, perchloric acid extracts of the livers were prepared and NMR spectra obtained. Isotopomer analysis using glutamate resonances in these spectra showed that the relative contributions of endogenous and exogenous substrates to the acetyl-CoA entering the tricarboxylic acid cycle differed significantly between infected and control groups. The mole fraction of acetyl-CoA that was derived from endogenous, unlabelled sources (F(U)) was 0.50 +/- 0.10 in controls compared to 0.34 +/- 0.04 in infected animals. However, the fraction of acetyl-CoA derived from [3-13C]lactate (FLL) was larger in livers of infected animals than those from controls with values of 0.27 +/- 0.04 and 0.18 +/- 0.04, respectively. Similarly, the fraction of acetyl-CoA derived from [1,2-13C2]acetate (FLA) was larger in livers of infected animals compared to those in controls; the fractions were 0.38 +/- 0.01 and 0.32 +/- 0.07, respectively. The ratio of FLA:FLL was significantly smaller in the infected group with a value of 1.42 +/- 0.18 compared to 1.74 +/- 0.09 for the controls. These results indicate that alveolar hydatid disease has a pronounced effect on the partitioning of substrates within the pathways of carbohydrate metabolism in the host liver.     

Echinococcus multilocularis: Immunoglobulin and antibody response in C57BL6J mice

Each of 50 male C57BL/6J mice was infected intraperitoneally with 50 cysts of Echinococcus multilocularis. At 2, 4, 6, 8, and 14 weeks after infection, 10 mice were sacrificed, their larval cyst masses weighed, and their sera collected. Each serum sample from uninfected control and infected mice was adsorbed twice with two batches of E. multilocularis antigen conjugated to Sepharose beads. The concentrations of IgG1, IgG2a, IgG2b, IgM, and IgA in unadsorbed and IgG1, IgG2b, and IgM in adsorbed sera were quantified by the radial immunodiffusion technique. Hydatid mice produced increasingly large amounts of IgG1 and IgM; small measurable increases of IgG2b and no significant increases of IgG2a and IgA were observed during the course of infection. During the rapid growth phase of the cysts (6 to 14 weeks) IgG1 antibodies were found to range from 86 to 93% and IgM antibodies from 17 to 33% of the total IgG1 and IgM. However, the actual protein concentrations of IgM antibodies (761 and 1215 mg/dl) were higher than the sum of the protein concentrations of IgG1 and IgG2b antibodies (411 and 779 mg/dl). The significance of the relative concentrations of IgM, IgG1, IgG2a, and IgG2b antibodies is discussed with reference to their effectiveness in antibody-dependent cellular cytotoxicity and complement-mediated lysis in the control of alveolar hydatid disease.     

In vivo efficacy and ultrastructural effects of mitomycin C against experimental alveolar hydatid disease

The in vivo efficacy and ultrastructural effects of mitomycin C were determined against alveolar hydatid disease in experimentally infected animals and compared to mebendazole treatment. Mitomycin C inhibited the mean cyst mass of treated versus control animals by 84.1% which was statistically significant at the alpha = 0.01 level. Mebendazole given daily inhibited the mean cyst mass by 80.1%, while mebendazole administration on the same treatment schedule as that used for mitomycin C inhibited the mean cyst mass by 70.4%. Ultrastructurally, mitomycin C was not observed to affect the tegumental microtriches (microvilli) or the microtubular system. However, an increase in the number and accumulation of round to oval electrondense vesicles was observed within the subtegument. These inclusion bodies became vacuolated, subsequently degenerated, and formed myelin-like figures. Mitomycin C, like mebendazole, was only cystistatic in its effects on the cyst stage of Echinococcus multilocularis as evidenced by the growth of treated cyst material following inoculation into helminth-free animals.     

Control of hydatid disease in Wales.

OBJECTIVES--To evaluate the success of the south Powys hydatid control programme by analysis of trends in cystic disease in humans and sheep and dog infestation. DESIGN--A review of hospital admissions for human hydatid disease in 1984-90, abattoir prevalence surveys of hydatid cysts in adult sheep, arecoline acetarsol and coproantigen surveys of prevalence of Echinococcus infestation in dogs. SETTING--All hospitals in England and Wales, three abattoirs, and dog populations in mid ands south east Wales. SUBJECTS--Residents of England and Wales admitted to hospital between 1984 and 1990 with a new diagnosis of human hydatid disease (International Classification of Diseases (ICD), ninth revision, code 122) acquired in the United Kingdom. RESULTS--The average annual incidence of human hydatid disease in Powys, mid-Wales, fell from 3.9x10(-5) in 1974-83 to 2.3x10(-5) in 1984-90. Age specific incidence rates in Wales declined over this period only in children, and no cases occurred in children (<15 years) in Powys. Two Welsh children who lived in Gwent and mid-Glamorgan were infected. Prevalence of hydatid cysts in old sheep from south Wales declined during the control period, but in 1993 prevalence of cysts was 13%. Prevalence of E granulosus infestation was zero in the control area in 1993, but it was 2.4% in Powys dogs outside the control area in 1989 and 9.2% in dogs in Gwent in 1991. CONCLUSIONS--Human hydatid disease has been successfully controlled in south Powys but cystic echinococcosis is still endemic in sheep in mid-Wales, and there is a focus of infection in humans, sheep, and dogs in the bordering areas of Gwent and mid-Glamorgan. There is considerable potential for an upsurge in human cases if control measures are relaxed.     

Diagnostic and therapeutic of human hydatidosis. Study of a hospital case series

A case-study on 95 inpatients with hydatid disease admitted to a community hospital in Milan is presented. Clinical records from January 1975 through December 1985 were reviewed. Data were analyzed according to: individual characteristics of the subject; previous history of hydatid disease and present signs and symptoms; tests and instrumental examinations performed to ascertain the disease; type of treatment and outcome. Liver (56%) and lung (18%) were the most commonly involved organs, but lung location was, relatively to age, more frequent in children and teenagers than in adults. Intradermal (Casoni) or serological (Ghedini) tests and scintigraphy for the hepatic localization, and lung stratigraphy or histologic section for the pulmonary one, were the most frequent examinations performed. Seventy-three patients (77%) underwent surgical treatment.     

The serodiagnosis of human hydatid disease: 1. The routine use of latex-agglutination and complement-fixation in diagnosis

The combined use of complement fixation (CF) and latex agglutination (LA) tests is reported on sera from 6328 patients with suspected hydatid disease; 191 were confirmed positive at operation ('known positives'). Results by LA are related to CF titres. Both tests were negative in 90% of specimens. Nine patients were subsequently found infected of whom 3 became positive in tests after operation. Of sera positive in both tests, 75% were from 'known positives'. The remainder were almost certainly from infected patients. Half the patients whose sera were LA positive/CF less than or equal to 1/4 were follow-up 'known positives' in whom CF titres had waned; 2 were early infections. Only 3% of the cases with an LA negative/CF titre of greater than or equal to 1/16 were 'known positives' and 6% where the CF titre was 1/8. The remaining CF results in the group were false positives and accounted for 1.2% of all sera tested. Findings show that a CF titre greater than or equal to 1/8 with positive LA indicates past or present infection; a negative CF test with positive LA usually indicates past infection; rarely, infection is present when a CF titre is greater than or equal to 1/8 and LA is negative. A rising CF titre and positive LA indicates current infection; reliable prognosis following treatment is given by CF.