马来丝虫实验感染家猫及周期性观察

在实验室家猫感染周期型马来丝虫较为困难。我们采用将感染期幼虫直接注射到腘窝淋巴结的方法感染家猫成功,并对微丝蚴的周期性进行了观察,结果报告如下。一、材料与方法 (一)感染期幼虫的收集:用本所实验室饲养驯化的中华按蚊,光照下以胎盘膜饲血瓶喂食37℃混有周期型马来丝虫感染长爪沙鼠腹腔液的兔血。饲血后于28℃饲养11天,贝氏分离法收集感染期幼虫,备用。 (二)实验动物及感染方法实验用6只家猫均购自马来丝虫非流行区。猫龄6月～4岁,人工感染前血检均未发现微丝蚴。实验感染时,将家猫固定于实验台上,轻度麻醉。     

用单克隆抗体鉴定马来丝虫阶段特异性共同抗原

为了鉴定在丝虫感染时能引起保护性的、致病性的以及变态性的免疫反应的寄生虫抗原,作者制备了一系列针对马来丝虫各期(成虫、微丝蚴和感染期幼虫)的特异性的单克隆抗体。首先从血餐后12～14天的埃及伊蚊收集感染期幼虫。微丝蚴和成虫均从阳性沙鼠     

左旋四咪唑在体外对懒猴丝虫感染期幼虫、微丝蚴和成虫的作用

作者不久前曾介绍了左旋四咪唑在宿主体内对懒猴丝虫的效果。本文报告了该药在体外对懒猴丝虫感染期幼虫、微丝蚴和成虫的作用。感染期幼虫取自实验室纯系培养的骚扰阿蚊(在叮咬阳性动性12天后解剖),微丝蚴从宿主血液中分离,成虫在解剖阳性动物后获得。将上述三个虫期分别放置于含有     

中华按蚊传播亚周期型马来丝虫能力的研究

用中华按蚊人工感染亚周期型马来丝虫,观察其摄入的微丝蚴数、胸肌中的幼虫数和感染期幼虫数。以每蚊体内感染期幼虫数与摄入微丝蚴数之比作为传播能力。结果表明,在温度为28±1C,相对湿度75％的条件下,亚周期型马来丝虫在中华按蚊体内约需10～12d发育成熟,传播能力为10％。     

马来丝虫长爪沙鼠动物模型保种衰退期的观察

目的　观察马来丝虫经长爪沙鼠传代的衰退情况。　方法　用马来丝虫微丝蚴感染中华按蚊 ,收集感染期幼虫 (L3) ,通过腹腔接种感染长爪沙鼠 ,连续观察 3 3代长爪沙鼠体内马来丝虫微丝蚴的发育情况。　结果　从 1974年建立的马来丝虫长爪沙鼠动物模型至今 ,通过 3 3代传代 ,发现随着转种代数增加 ,从第 2 8代起长瓜沙鼠的阳性率逐年下降 ,由 2 8代的 80 %下降至 3 2代的 16% ,到 3 3代时阳性率降为 0。　结论　经过较长期的传代 ,马来丝虫幼虫难以在长爪沙鼠体内发育繁殖。     

马来丝虫贵州株传代的实验观察

目的 观察马来微丝蚴贵州虫株传代现象。方法 分别用周期型马来丝虫贵州虫株f31和f25微丝蚴人工感染中华按蚊，在温度、相对湿度相同的条件下，观察幼丝虫在蚊体内发育情况。结果 贵州虫株f31在感染中华按蚊后24h解剖，仅在按蚊腹部和胃内可见脱鞘和未脱鞘的微丝蚴，第2～9d未发现各期幼丝虫，经6批次实验，结果相同。贵州虫株f25感染中华按蚊后24h解剖，蚊胃内未发现微丝蚴，在胸部可见早期腊肠期(L1)幼丝虫，第2～9d解剖可见各期发育中的幼丝虫。结论 贵州虫株f31马来微丝蚴经6批次传代失败，可能与同一地方单一虫株的多次传代发生遗传突变有关。     

人体丝虫病诊断中的排泄-分泌抗原及体抗原

本文报道以金黄色葡萄球菌固相放射免疫试验(SPRIA)比较马来丝虫成虫的排泄-分泌抗原(E-S)和成虫、感染期幼虫及微丝蚴的体抗原用于免疫诊断的价值。     

用亚周期型马来丝虫实验感染叶猴(Presbytis cristat和P.melalophos)

已知Presbytis属叶猴是亚周期型马来丝虫的自然宿主,已建立了P.melalophos亚周期型马来丝虫的模型,供筛选药物。鉴于需要发展其他非人类灵长目淋巴丝虫病模型,不仅用于筛选药物,而且用于研究宿主-寄生虫关系和感染的病理免疫学的重要性,作者在P.cristata中也进行了研究。挑选来自非疫区体重为4～5 kg的P.melalophos和P.cristata叶猴,微丝蚴检查为阴性,对感染疟疾或其他肠道寄生虫的猴分别用氯喹和噻苯达唑治疗。在叶猴右后腿内侧中部皮下接种约200条亚周期型马来丝虫感染期幼虫,此感染期幼虫采自13天前叮咬微丝蚴血症叶猴的东乡伊蚊。6星期后,开始每周采血1ml,薄膜过滤检查微丝蚴。前后共感染97只P.cristata叶猴和45只P.melalophos.叶猴.     

根据微丝蚴在体外的脱鞘区分周期型和亚周期型马来丝虫和彭亨丝虫

马来丝虫有夜间周期型和夜间半周期型两种类型,而这两型马来丝虫的传播媒介不同,亚周期型又有动物保虫宿主,因此区分这两型马来丝虫,在流行病学上具有重要的意义。曾有人发现在厚血片中许多周期型马来丝虫微丝蚴有脱鞘的倾向,亚周期型马来丝虫微丝蚴则无此现象。本文作者对两型马来丝虫和彭亨丝虫的微丝蚴在体外不同条件下出现脱鞘的情况作了观察。取两型马来丝虫携带者及阳性猫的60立     

班氏丝虫动物模型研究进展

本文报道了近年来有关班氏丝虫动物棋型研究的进展,初步结果表明班氏丝虫感染期幼虫接种啮齿类小动物,虽然多数虫体未能完成发育,但有1只沙鼠于接种后92天在肺部找到1条成熟雄虫,证明班氏丝虫能在啮齿类动物体内发育到成虫期。Disssnaike等以班氏丝虫感染期幼虫接种1只切脾猕猴并注射甲基泼尼松龙醋酸盐,按种后231天剖检,找到雄、雌成虫11条。Cross等以感染期幼虫接种78只猕猴,29只回收到发育的幼虫和成虫,8只雄猴出现微丝蚴血症,总阳性率为47.44％。感染恒河猴和食蟹猴各3只,各有1只找到成虫。Palmieri等1978年首次从银叶猴体内发现吴策丝虫的自然感染,解剖20只微丝蚴血症猴有7只找到雄成虫。Harinata等以不同数量的班氏丝虫感染期幼虫接种叶猴,剖检均发现成虫及微丝蚴。近年来研究结果证明,台湾猕猴和叶猴对班氏丝虫具有较高的易感性,可作为动物模型,为研究宿主-寄生虫-媒介相互关系提供了条件,有利于对丝虫病的病理学、免疫学、药物筛选、治疗以及发展丝虫疫苗等方面的探索研究。但这些猴类均属珍贵动物,来源有限,不适于一般实验室的应用。此外,很需要适当的动物模型以供研究发病机理和实验治疗之用。在今后丝虫病防治方面,对班氏丝虫动物模型的研究应列为重要课题之一。     

周期型马来丝虫实验感染小白鼠体内发育和病理观察

目的 观查周期型马亚丝虫在小白鼠体内发育和病理变化。方法 生只鼠腹腔内注射从东乡伊蚊收集６０－２００条感染期幼虫，定期抽查微丝蚴并解剖观察病理变化。结果 在感染泊３０－３１０天解剖分别检获Ⅳ期，幼虫，童虫和成虫，成虫阳性率为３４．６２％（９／２６），主要病变为淋巴管炎、淋巴结炎，及其周围炎，在肺、脾、睾丸和精索可见淋巴栓塞，含有成虫和炎细胞，肺部可见退行性变的成虫和幼虫，形成丝虫性肉芽肿性病变。结     

Protective immunity to Brugia malayi larvae in BALB/c mice: potential of this model for the identification of protective antigens

Protective immune responses against the infective larvae of Brugia malayi have been demonstrated in BALB/c mice. Various factors governing resistance to reinfection have been examined to provide baseline data for use of this model in studies of immunoprophylaxis. Parasites that established following a primary infection survived for approximately 10 days, following which numbers declined rapidly to a low level. Resistance was evidenced by a more rapid clearance of secondary infection parasites. The degree of immunity expressed was not related to the route of administration of the initial infection (subcutaneous, intravenous, intramuscular, or intraperitoneal). However, both the level of resistance and the rapidity of its expression were dependent on dose, with as few as 2 larvae stimulating measurable immunity. Sensitization with living male or female adult worms, fourth stage larvae or microfilariae of B. malayi, or infective larvae of B. pahangi conferred substantial resistance to larval challenge. Significant levels of immunity were also induced by dead B. malayi larvae (46%) and their aqueous extracts (76%), but not with the corresponding insoluble fraction. We suggest that this experimental system is ideally suited to aid in the identification of putative protective antigens in brugian filariasis.     

影响马来丝虫对长爪沙鼠感染率因素的观察

目的：探讨影响马来丝虫对长爪沙鼠感染率的因素。方法：用含马来丝虫感染期幼虫（Ｌ３）生理盐水感染长爪沙鼠，并分别加用抗生素、葡萄糖或培养液ＲＰＭＩ１６４０，观察接种鼠的存活率、感染率和感染度。结果：用含Ｌ３生理盐水组鼠存活率为８０．９％，存活鼠感染率为６０．５％，高感染度率为４３．４％。加用抗生素组，鼠存活率为９８．８％，存活鼠感染率为５２．９％，高感染度率为３０．６％。加用葡萄糖或ＲＰＭＩ１６４０组，鼠存活率（分别为９８．０％和９１．２％）、感染率（分别为６８．８％和６７．７％）和高感染度率（分别为５０．０％和５１．６％）均较高。长爪沙鼠感染马来丝虫浙江株（６代），存活鼠感染率和高感染度率均较贵州株（３１代）高。结论：加用抗生素能提高感染鼠存活率，但其感染率和感染度降低。加用葡萄糖和ＲＰＭＩ１６４０，能提高感染鼠存活率、感染率和感染度。长爪沙鼠对浙江株（６代）较贵州株（３１代）易感。     

Experimental attempts to induce ocular infection in cats with subperiodic Brugia malayi.

In an attempt to determine whether the finding of human ocular lesions due to B. malayi was due to the site of entry of the infective larvae, cats were infected via ocular instillation, subconjunctival inoculation, subcutaneous inoculation around and infective mosquito bites over the eyes. Although no conjunctival lesion was seen patent infections were produced via ocular instillation, subconjunctival and subcutaneous inoculation of infective larvae. Adult worms were also recovered from periorbital tissues. Adult worms were localized mainly in the lymphatic system of the head and neck regions of the cat. The results show that the conjunctival lesions seen in humans could be due to the site of bite of the mosquito and thus the entry of the infective larvae.     

Quantitative aspects of the development of mosquito transmitted Brugia malayi and Brugia pahangi and their distribution in Jirds, Meriones unguiculatus.

Twenty-two jirds, Meriones unguiculatus, were exposed to the bites of 2250 females of Aedes aegypti carrying an estimated total of 2464 larvae of Brugia malayi, and 13 jirds were offered for blood feeding to 1450 mosquitoes infected with about 4460 larvae of Brugia pahangi. On necropsy of the jirds, four months after feeding of the mosquitoes, a total of 88 adult filariae of B. malayi and 143 of B. pahangi were recovered in 20 and 13 jirds respectively. The majority of the adult filariae was obtained from the testes (48,9% of B. malayi and 53,2% of B. pahangi), from the heart-lung-system (26,1% and 45,6%), and additional in B. malayi from the tail (19,3%). It can be estimated that 3,6% (3,2%) of all infective larvae of B. malayi (B. pahangi), carried by Aedes aegypti females before feeding, reached maturity in the jird host after they had left the vectors during the blood meal. Microfilariae were found in the peripheral blood in seven of B. malayi infected jirds and in eleven of the jirds infected with B. pahangi.     

Infections of Brugia pahangi in conventional and nude (athymic) mice

AKR, BALB/c and CBA/Ca and T.O. mice were completely resistant to infection with third stage infective larvae of Brugia pahangi. Third, fourth and fifth stage worms transplanted from the peritoneal cavity of jirds into the peritoneal cavity of mice continued to develop. BALB/c mice were the most susceptible of the strains tested and adult worms were obtained after each type of transplanted infection. Congenitally athymic nude mice were much less resistant to transplanted worms and infective larvae developed to full maturity in most of them. Ten of 14 athymic mice infected by the intraperitoneal (ip) inoculation of infective larvae had microfilariae in their blood or peritoneal cavities. At autopsy a percentage recovery of adult worms of 0-38% (mean 11.1%) was obtained. Microfilariae were only found in the blood of 2 of 6 athymic mice infected by subcutaneous (sc) infection and at autopsy 0-19.1% (mean 6.1%) recoveries were obtained. The thymic littermates of the nudes were more resistant than those most of the other strains used.     

抗独特型抗体对马来丝虫感染沙鼠的保护性免疫效果观察

目的 :研究抗丝虫抗独特型抗体 (抗 fil-抗 Id- Ab)对丝虫感染沙鼠的保护性免疫作用。方法 :从班氏丝虫病乳糜尿和鞘膜积液患者血清中分离含有高滴度的 Ig G,免疫家兔 ,获得兔抗 fil-抗 Id- Ig G,免疫沙鼠 ,再用马来丝虫感染期幼虫攻击 ,观察其免疫效果。结果 :抗 fil-抗 Id- Ig G一次脾内注射或多次皮下及腹腔内免疫后 ,50 %和 80 %沙鼠产生保护性免疫效果 ,沙鼠体内查不到微丝蚴和成虫 ,而从马来丝虫成虫可溶性抗原或兔抗正常人 Ig G为对照组的沙鼠中 ,80 %沙鼠感染丝虫 ,与正常感染组相近似。结论 :用抗 fil-抗 Id- Ab对马来丝虫感染沙鼠 ,证实有保护性免疫作用。     

Ultrasonography in filaria-infected rodents: detection of adult Litomosoides sigmodontis and Brugia malayi filariae

OBJECTIVE: To evaluate the usefulness of ultrasonography (USG) in the detection of adult filariae in rodents. Wuchereria bancrofti are frequently detected using USG in humans, whereas adult Brugia malayi have not been so far. METHODS: A Meriones unguiculatus with Litomosoides sigmodontis infection was examined to visualize adult filariae of a similar length as W. bancrofti. Similarly, three Mastomys coucha, infected with B. malayi, were examined using USG to verify whether the adult worms, which are far smaller than W. bancrofti and L. sigmodontis, can be located using USG in the animals. RESULTS: Adult L. sigmodontis were detected using USG in the pleural cavity of M. unguiculatus, and in M. coucha adult B. malayi were visualized in the hearts, lungs, axillary lymph nodes and scrotum. Ultrasound findings were verified by dissection of the rodents. CONCLUSIONS: Although adult B. malayi are far smaller than L. sigmodontis and W. bancrofti, they can be detected using USG in rodents. USG may serve as an adjunctive tool to support parasitological examinations and can add information on filarial infections at any time point of an observation period, particularly in cryptic infections and without the need for invasive measures or killing of the rodent. Thus, USG can support the early detection of macrofilaricidal activities of new compounds and can be used to determine the location of adult worms in the animals. It is possible to give a rough estimate of the number of adult worms, but determination of the exact numbers of adult filariae in various locations is impossible with USG.     

Effect of diethylcarbamazine citrate on fourth stage and adult Brugia malayi in cats.

Sixty-three experimental and 58 control cats were infected with Brugia malayi so that the developing and adult worms localized in the regional lymphatics of the hind legs. At 20 days after infection when Brugia were in the 4th larval stage, and at 8 weeks when worms were young adults, cats were divided into groups to test the efficacy of diethylcarbamazine citrate (DEC) at various dosage levels. At 100 mg total DEC/kg no 4th-stage larvae were seen in 5 cats compared with a mean of 20.4 living larvae in each of 5 controls. At this level of DEC, 2 of 5 cats had 1 and 2 adult worms while 4 of 4 controls had a mean of 23.2 living adult worms. At 50 and 25 mg/kg there was a substantial reduction of both 4th stage and adult worms when compared to controls. At 10 mg/kg, 4 of 6 cats had 4th-stage larvae but at a lower level (mean = 7.0) than in 6 controls (mean = 23.2). No reduction of either 4th-stage larvae or adult worms was seen at 1 mg/kg. This study establishes the efficacy of DEC against 4th-stage and adult Brugia malayi in cats, although considerably higher levels of the drug were required than the level previously determined to kill 3rd-stage larvae. It appears that the cat-B. malayi model will be an effective method to compare the efficacy of drugs against adult lymphatic-dwelling filariae.     

Filarial infections of Mastomys natalensis and their relevance for experimental chemotherapy

Experimental filarial infections of Mastomys natalensis, strain GRA Giessen, with Litomosoides carinii, Dipetalonema viteae, Brugia malayi (subperiodic), and Brugia pahangi were compared. Mean prepatent periods of 52, 57, 107, and 73 days p.i. were observed after subcutaneous inoculation of 40, 50, 85, and 70 infective larvae of L. carinii, D. viteae, B. malayi, and B. pahangi, respectively, in the neck region. All of the L. Carinii, D. viteae, and B. pahangi infected Mastomys showed a regularly detectable microfilaraemia. In B. malayi infections 95.5% of the animals developed parasitaemias, when the larvae had been inoculated in the neck region, whereas after groin infections only in 66.7% of the animals became patient. For both Brugia species, infections in the groin resulted in considerably lower microfilarial levels. Maximum microfilariae densities could be detected at day 120 (L. carinii) and at day 1980 (D. viteae) p.i. In the case of Brugia neck infections, the microfilarial levels increased usually until the end of the observation period, 300-350 days p.i. Worm recovery rates were 63% (L. carinii), 20.6% (D. viteae), 21.1% (B. malayi), and 31.4% (B. pahangi) of the inoculated larvae. When third stage larvae of Brugia species were inoculated in the neck region, adults of B. malayi and B. pahangi were isolated predominantly from the heart of lungs (84.4 and 78.5%, respectively). Only 12.3% of B. pahangi parasites were found in the testes; 3.4% and 18.1% were localized in the lymphatics. After inoculation of infective larvae in the groin more worms could be recovered in the testes and lymphatics, i.e. 23.4% and 14.9% (B. malayi) or 19.1% and 45.2% (B.pahangi), respectively. The results are discussed under the aspect of chemotherapeutic investigations for the evaluation of microfilaricidal, macrofilaricidal or chemoprophylactic compounds. It is concluded, that Mastomys natalensis, an animal with a broad spectrum of susceptibility for filarial infections, can be used as an alternative experimental model system, similar to that of the jird.