卫氏并殖吸虫童虫回收和体外保存的实验研究

将实验感染卫氏并殖吸虫囊蚴的21只小鼠和25只大鼠的组织碎片,分别浸于37℃林格氏液中,不同时间内共检获游离的童虫3026条,其中93.6％及98.5％以上的童虫是于浸泡2及4小时检获的,提示此法浸泡2—4小时即可回收绝大多数的虫体。对检获的活虫保存在4—8℃的灭菌生理盐水,林格氏液或囊蚴保存液中,至少可活5天,个别童虫在囊蚴保存液中可活39天以上,而同液保存在20—25℃或37℃中,1—2天即有童虫死亡,5—10天全部死尽。     

卫氏并殖吸虫在小鼠体内滞育现象的进一步观察

在卫氏并殖吸虫转续宿主(Paratenic host)的研究中,用小鼠作为动物模型的文献很少,而且均写为用囊蚴感染小鼠后的观察,动物用量也少,因而有所局限。我们在以小鼠等常用实验动物进行卫氏并殖吸虫的宿主转换及转续传播的研究中,分别用囊蚴和滞育童虫感染了大量小鼠,对该虫种在小鼠体内的滞育现象作了进一步观察,报告于下:     

安徽南部石台并殖吸虫囊蚴感染初报

1939年吴光报告在安徽省的豹体内发现卫氏井殖吸虫(Paragonimus westermani),1951年吴氏又在绩溪的石蟹体内见有该虫囊蚴。1964年4月我们在皖南石台县七里溪和柯村采集的锯齿石蟹(Potamondenticulatus H.Milne-Edwards)亦检到囊蚴,感染猫、犬后获得该虫成虫。有关成虫的详细观察结果将另文报告。 囊蚴检查均按只捣碎水洗沉淀,七里溪和柯村河石蟹共检查130只,检获囊蚴970个,感染率     

异盘并殖吸虫囊蚴的观察

对人致病的并殖吸虫(肺吸虫)在亚洲有3种,即卫氏并殖、斯氏并殖和异盘并殖吸虫。异盘并殖吸虫对人致病的特点是:童虫可在人体皮下游走,形成包块,并且可以在人体肺部组织发育成熟,形成虫囊,与人类疾病有密切关系。 关于异盘并殖吸虫(Paragonimus heterotremus Chen and Hsia,1964)囊蚴的记述先后有     

闽清并殖吸虫成虫和童虫的扫描电镜观察

闽清并殖吸虫(Paragommuw minpingensis Li et Chen,1983)系根据病人线索检查溪蟹,找到的囊蚴感染动物而获得虫体,其形态特点介乎于椭圆形的卫氏并殖吸虫与长梭形的斯氏、四川、会同、曼谷并殖吸虫之间而与三平正并殖吸虫相近似,目前只发现于福建省局部地区。由于它与卫氏并殖吸虫囊蚴混合感染,因此对其进一步的研究将有助于了解对人体致病性以及虫种间的系谱关系及种类间的鉴别。     

安徽歙县并殖吸虫囊蚴感染报告

1964年4月我们在皖南石台的华溪蟹(Sinopotamon)检到囊蚴后。1965年4月又从歙县西溪南公社依坑溪(黄山南20余公里)的华溪蟹中检获二种囊蚴:一种为其他科吸虫囊蚴,将另文报告;一种为卫氏并殖吸虫(Paragonimus westermani)囊蚴,感染猫、犬后获得该虫成虫,兹将结果报道如下。 材料与方法 所有华溪蟹系1965年4月从歙县西溪南公社依坑溪采集。按体重、性别分10克以上、5—10克、5克以下(以下简称大、中、小蟹)三组,捣碎水洗沉淀。在解剖镜下观察并测量囊蚴。     

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。     

异盘并殖吸虫在小鼠体内发育及宿主转换的研究

在我国,引起人体患病的并殖吸虫有卫氏并殖吸虫(Paragonimus westermani)、斯氏狸殖吸虫(Pagumogo-nimus skrjabini)以及尚未引起人们足够重视的异盘交殖吸虫(Paragonimus heterotremus)三种。自从1965年广西那坡县发现异盘并殖吸虫疫源地和一例痰中查见虫卵的患者以来,泰国、老挝等地也分别报告了该虫引起游走性皮下结节与在肺内检获成虫的病例。异盘并殖吸虫对人体的致病性、宿主关系及传播方式等问题,引起了人们的关注。近年来,卫氏并殖吸虫和斯氏狸殖吸虫在非正常宿主体内的发育及宿主转换的研究,日趋深入。研究结果表明,此两种并殖吸虫病均可由转续宿主介导或经宿主转换而传播。异盘并殖吸虫在这方面的研究,迄今尚未涉及。为此,我们以小鼠为动物模型,进行了宿主转换的研究。     

针毛鼠作为卫氏并殖吸虫转续宿主的发现

自1975年乘松(Norimatisu)在日本鹿儿岛首先发现当地群众因生吃野猪肉感染并殖吸虫后,宫崎(Miyazaki) 等进一步在野猪(Susscofa leucomystax)肩部肌肉中检出卫氏并殖吸虫(Paragonimus westermani)童虫,从而确定在     

安徽南部卫氏并殖吸虫囊蚴和成虫研究

卫氏并殖吸虫Paragonimus westermani(以下简称卫氏)是我国人体肺吸虫病的重要病原,在国内分布广泛,已发现人体感染12省,保虫宿主16省、区,蟹类或蜊蛄阳性12省(陈心陶,1965)。吴光(1939,1951)在皖南豹体和蟹体发现该虫成虫和囊蚴;1973年后陆续有蟹体囊蚴和大量人体感染报告(沈铭程等,1975;蚌医寄生虫学教研组等,1977)。该虫囊蚴形态见于文献,而成虫形态,只我国台湾省(永吉康祐,1942)、朝鲜(小林晴治郎,1919)、日本(田边薰,1950)的材料有过详细研究,我国大陆方面对这一人体重要并殖吸     

Delayed macrofilaricidal activity of diethylcarbamazine against Brugia pahangi in Mongolian jirds

The macrofilaricidal activity of diethylcarbamazine (DEC) was confirmed in jirds infected with Brugia pahangi. Seventy jirds were inoculated subcutaneously with 100 infective larvae. At 20 weeks post-infection, the microfilaraemic jirds were divided into two groups, untreated and treated. For the treated group, 200 mg kg(-1) of DEC was injected intraperitoneally for 5 consecutive days. One, 4, 8, 12, 16 and 27 weeks after the final treatment, 4-7 jirds in each group were sacrificed to measure adult worm burdens. The number of adult worms recovered from treated jirds was comparable to controls at earlier necropsy (1 and 4 weeks post-treatment). However, at late necropsy (8 weeks and later) the recovery rate of adult worms in treated jirds was significantly lower than that in untreated controls, indicating an adultcidal effect of DEC. The present study demonstrates that DEC requires 8 weeks to kill B. pahangi adult worms in jirds and that the Mongolian jird is a useful model for screening antifilarial activity.     

Induction of protection against Brugia malayi infection in jirds by microfilarial antigens

The development of immunologic methods to reduce transmission of human lymphatic filariasis depends on measures that will enhance the host's ability to eliminate infective larvae, adult worms, or blood-borne microfilariae (mf). The present study was designed to assess the capacity of a crude extract of Brugia malayi mf to decrease the level of microfilaremia and adult worm burden in jirds inoculated with infective larvae, and to identify the filarial antigens that elicit antibody responses in these animals. Thirty weeks after subcutaneous inoculation with 75 infective larvae, 100% of control jirds were patent (i.e., had microfilaremia) compared with 60% of the group immunized with 10 micrograms of crude microfilarial extract (p less than 0.05). In addition, microfilaremia was lower in patent immunized animals compared with controls (p less than 0.05). The mean total number of adult female B. malayi per jird recovered at necropsy in control animals was 16.0 vs 7.0 in immunized jirds (p less than 0.05). Serum of immunized jirds contained anti-mf antibodies with an end titer of 1:8000, a value similar to that of animals with chronic B. malayi infection. Microfilarial antigens of Mr approximately 150,000, 75,000, 42,000, and 25,000 were identified in immunoblotting studies by reactivity with antibodies in sera of immunized jirds. Antibodies induced by immunization with microfilarial extract were not specific for this stage of the parasite life cycle, as jird anti-mf antibodies reacted with a Mr approximately 150,000 and several Mr 50,000 to 110,000 antigens derived from immature and mature adult parasites of both sexes. These data indicate that immunization of jirds with a water soluble microfilarial extract enhances the host's ability to eliminate adult worms and blood-borne mf. The filarial antigens that induce antibodies in immunized jirds have been identified.     

Transplanted Dipetalonema viteae in the jird: effect of worm burden on parturition rates and microfilaremia

Dipetalonema viteae was studied in the jird, Meriones unguiculatus, to determine the mechanism controlling the level of peripheral microfilaremia. Jirds killed 40 days after infection served as donors of female worms of known age and reproductive status. These worms were transplanted into uninfected jirds and the resultant microfilaremias were monitored. After approximately 100 days, the recipient jirds were killed and 58% of the transplanted worms were recovered alive but depleted of sperm and microfilariae, regardless of the total number implanted in a given host. A direct linear relationship between microfilaremia and the number of recovered adult worms was found. Based on the uniform absence of sperm and microfilariae in the recovered worms it was concluded that female worms, under the conditions of the present study, do not control the peripheral microfilaremia in multi-worm infections through a reduced parturition rate.     

The transmission of an avian filarioid Cardiofilaria nilesi to the jird, Meriones unguiculatus

This paper reports the experimental transmission of a bird parasite into jirds. Infective larvae of Cardiofilaria nilesi obtained from laboratory colonized Coquillettidia crassipes mosquitoes which had fed on an infected chicken were inoculated subcutaneously into jirds. The number of larvae per jird varied from 10 to 228. Microfilaraemia appeared 22 to 89 days after inoculation of the infective larvae. Experiments were carried out with 24 jirds through six generations extending over a period of 22 months and 17 produced patent infections. At present 8 infected jirds are being maintained in the laboratory; their patent periods ranging from 6 to 13 months. However, the longest patent period observed was about thirteen months. The percentage of adults recovered in autopsied jirds ranged from 0 to 40 with an average of 16. The chicken showed a microfilarial periodicity with the peak microfilarial density around 2200 hours. However, in jirds there was a change in sub-periodicity. This model in the jird may be very useful for the screening of filaricides and in immunological work.     

Effect of CGP 20376 on Brugia malayi and parasite antigenemia in jirds

This study was designed to investigate the activity of CGP 20376, a benzothiazole derivative, against Brugia malayi in jirds and to illustrate the utility of parasite antigen detection as a means of monitoring drug efficacy in filariasis. Drug treatment was 100% effective in jirds treated 3 or 24 days after infection. Microfilaria and adult worm counts were reduced (relative to counts in sham-treated control animals) by 96% and 95%, respectively, in animals treated 153 days after infection. Four of 6 animals in this treatment group cleared their microfilaremias and were free of adult worms 5 mo after treatment. Thus, CGP 20376 was effective against all life cycle stages of B. malayi in jirds. Parasite antigen levels in jird sera were consistent with parasitological results in all treatment groups, but antigen clearance was incomplete in some cases after apparently successful treatment of mature and immature infections.     

Concurrent infections with the ruminant nematodes Haemonchus contortus and Trichostrongylus colubriformis in jirds, Meriones unguiculatus, and use of this model for anthelmintic studies

Haemonchus contortus- and Trichostrongylus colubriformis-infected jirds (Meriones unguiculatus) are useful for anthelmintic studies. With concurrent infections of these parasites established in the jird, questions of not only anthelmintic activity, but to some extent spectrum, could be assessed in a single model system. This report outlines a model using immunosuppressed (0.02% hydrocortisone in feed) jirds concurrently infected with H. contortus and T. colubriformis. Immunosuppressed jirds were inoculated with approximately 1,000 exsheathed infective larvae of each species, treated per os on day 10 postinoculation (PI), and killed on day 13 PI. Stomachs and small intestines were removed, opened longitudinally, incubated in distilled water at 37 C for 5 hr, fixed in formaldehyde solution, and stored for subsequent examination. Contents of both organs were examined using a stereomicroscope (15-45 x). Various standard anthelmintics were evaluated in the model; modern broad-spectrum ruminant anthelmintics (benzimidazoles, febantel, ivermectin, levamisole hydrochloride, and milbemycin D) are active uniformly and in most cases at doses comparable to those required for efficacy against these parasites in ruminants. This model, using worms of 2 genera living in distinct sites, allows preliminary evaluation of anthelmintic activity and spectrum for experimental compounds in a single cost- and resource-efficient experiment.     

Utility of a Haemonchus contortus/jird (Meriones unguiculatus) model for studying resistance to levamisole

Trichostrongylid nematodes of sheep commonly are identified as exhibiting resistance to levamisole. In vitro assays have been developed to study levamisole resistance for Haemonchus contortus, but no in vivo model has been identified for this species. To determine the utility of a H. contortus/jird (Meriones unguiculatus) model for examining levamisole resistance, immunosuppressed jirds were inoculated with approximately 1,000 exsheathed infective larvae of H. contortus (resistant or susceptible to levamisole), treated per os on day 10 postinoculation (PI) with levamisole hydrochloride or analogs of the drug, and killed on day 13 PI. Stomachs were removed, opened longitudinally, incubated in distilled water at 37 C for 5 hr, fixed in formaldehyde solution, and stored for subsequent microscopic examination. Doses of levamisole and its analogs, which elicited percentage clearances of greater than or equal to 93.5 for the susceptible strain, cleared less than or equal to 68.9% of the resistant worms. These data are consistent with activities for the drugs against wild-type and levamisole-resistant strains of Caenorhabditis elegans. Thus, the H. contortus/jird model provides a useful in vivo tool to study resistance to levamisole and possibly other anthelmintics.     

Biology, breeding, husbandry and diseases of the captive Egyptian fat-tailed jird (Pachyuromys duprasi natronensis)

The fat-tailed jird, a small North African rodent with a distinctive club-shaped tail, is a convenient research subject and an emerging model for Old World leishmaniasis. The authors present the natural history and biology of the Egyptian fat-tailed jird and provide guidelines for the breeding and husbandry of this species on the basis of their experience raising a colony from wild stock in Cairo, Egypt. They also discuss the diseases they encountered in wild and captive-bred jirds.     

Circulating parasite antigen in Brugia pahangi-infected jirds

The Mongolian jird is used widely in filariasis research for studies of protective immunity, pathogenesis, and therapy. The purpose of this study was to evaluate parasite antigen detection as a means of noninvasively monitoring Brugia pahangi infection in jirds. A parasite antigen with Mr of 105-110 kDa was identified in sera from i.p.- and s.c.-infected jirds by immunoblot with a monoclonal antibody to phosphorylcholine. The same antibody was used in a direct sandwich enzyme immunoassay to measure antigen in jird sera. Parasite antigen was detectable as early as 2 wk after i.p. or s.c. injection of L3. Antigen titers increased between 2 and 12 wk and stabilized between 12 and 36 wk after infection in s.c.-infected animals. A different pattern was seen in i.p.-infected jirds with antigen titers peaking at 16 wk and falling significantly between 16 and 32 wk after infection. Parasite antigen titers correlated significantly with adult worm infection intensities in jirds with mature i.p. and s.c. infections. Antigenemia was also detectable in sera from jirds after i.p. implantation of adult parasites of either sex. However, antigen was not detected in sera from infant offspring of antigenemic infected mothers. We conclude that parasite antigen detection allows B. pahangi development and survival as well as infection intensity to be monitored in living animals with unprecedented sensitivity and accuracy. This technique should facilitate drug and vaccine studies in this important experimental filariasis model.