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。     

马来丝虫虫体抗原检测长爪沙鼠血清抗体

长爪沙鼠实验感染马来丝虫后,用感染期幼虫、微丝蚴的超声粉碎片段抗原和成虫的冰冻切片抗原,进行间接荧光抗体试验,观察血清抗体动态变化。抗感染期幼虫抗体多于感染后前3Wk内出现,抗成虫及微丝蚴抗体多于感染后前5、6wk内出现。在微丝蚴出现前,腹腔微丝蚴阳性和阴性沙鼠抗体水平差别无显著性,而在微丝蚴出现后,抗体水平具有显著性差别。     

马来丝虫感染沙鼠治疗前后血清抗体水手的动态研究

Indirect immunofluorescent antibody test (IFAT) and immunoenzymatic staining technique (IEST), using frozen section of Brugia malayi and Setaria cervi adult worms, were applied to detect levels of IgG and IgM antibodies in jirds infected with Brugia malayi before and after treatment. Both methods could show the dynamic of antibodies during the course of infection. The peak of IgG and IgM antibodies were at the 12-14th week and 2-6th week after infection respectively. A high correlation was observed between the levels of IgG antibody and the period of infection, whereas the antibody titer had no relation with the density of infection. During 6 months after treatment, the levels of antibodies detected by IFAT and IEST using two antigens decreased to low titre. It is considered that IFAT and IEST using heterologous and homologous antigens could be equally used for the serodiagnosis and the evaluation of cure in filariasis.     

长爪沙鼠种群增长的数学模型

根据内蒙古自治区伊克昭盟鄂托克旗查布苏木和鄂托克前旗布拉格苏木在１９８１～１９９０年４～５、１０～１１月份调查的长爪沙鼠密度资料，建立了种群增长指数模型Ｎｔ＝０．２２９３６ｅｘｐ｛１．１８１３５ｔ｝（Ｐ〈０．０５）。种群增长超指数模型Ｎｔ＝０．４３９１２ｅｘｐ｛０．１９２３２ｔ＾２．４｝（Ｐ〈０．００５），种群负增长指数模型Ｎｔ＝１３１８．４４７２５ｅｘｐ｛－０．６０７２３ｔ｝（Ｐ〈０．００５）。     

马来丝虫感染沙鼠治疗前后血清抗体水平的动态研究

应用马来丝虫和牛丝虫(Setaria cervi)成虫冰冻切片抗原作间接荧光抗体试验(IFAT)及免疫酶染色试验(IEST),均能显示马来丝虫感染沙鼠治疗前后血清IgG及IgM水平的消长情况。两者高峰分别在感染后12～14wk及2～6wk。IgG水平与感染时间长短有密切关系,但与感染度无显著相关。感染沙鼠治后6个月抗体下降。认为用同种和异种抗原作IFAT及IEST,对感染沙鼠均具有诊断和考核疗效的价值。     

某部营院烟雾弹灭长爪沙鼠效果观察

２００２年某部驻地附近地区发生动物鼠疫，为官兵不感染鼠疫，确保官兵的身体健康和国防试验任务的顺利进行，我们于２００２年６月２日至６月７日，在部队营院采用烟雾弹进行了灭鼠，取得了较好的灭鼠效果，结果如下。１材料与方法１．１营院情况营院长１１８m，宽１１４m，面积１３３５２m２，营院四周有约２m高的砖墙。营院和四周属于典型的荒漠草原，植物优势种为大针茅和小针茅为主。啮齿动物优势种为长爪沙鼠和达乌尔黄鼠。１．２烟雾弹烟雾弹是四子王旗卫生防疫站提供，包头市卫生防疫站生产。１．３方法在营院１３３５２m２灭鼠区…     

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.     

马来丝虫疫苗候选分子的研究进展

马来丝虫是一种能引发人类淋巴丝虫病的寄生线虫。其生活史和抗原成分复杂,寻找有效的疫苗一直是研究工作的重点。分子生物学、生物信息学的发展使研发新的高效安全的马来丝虫疫苗成为可能。该文就马来丝虫疫苗候选分子的研究进展作一综述。     

浙江省周期型马来丝虫等位基因酶谱研究

目的:研究浙江省周期型马来丝虫等位基因酶谱。方法:用微量平面淀粉凝胶电泳法,检测浙江省周期型马来丝虫成虫180 条(雌60,雄120),微丝蚴0.4 m l(约32 000 条)及感染期幼虫约1 500条的Acph 等14 种酶的同工酶的等位基因酶谱。结果:浙江省周期型马来丝虫的3 个生活期虫体呈现13 种酶的同工酶的27个等位基因位点,多数位点为纯合子型,仅2 个位点(MPI,MDH-2)为杂合子型(占7.4% )。成虫、微丝蚴及感染期幼虫分别呈现16、16 及9 个等位基因位点。同时用相同的方法对实验室传代的周期型马来丝虫等位基因酶谱进行比较检测。结论:浙江省与实验室传代的周期型马来丝虫的同工酶等位基因酶谱基本相似     

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。     

Genetic association of murine susceptibility to Brugia malayi microfilaraemia

Summary The influence of host genetics on susceptibility of mice to Brugia malayi microfilariae and its possible mechanism were studied. There was a strain-association for duration and peak level of microfilaraemia: CBA/CaJ, C3H/HeJ, DBA/1J, AuSs/J and A.Sw/Snhad a short duration (3–5 days) and low parasitemia (19–26 parasites/100 /il blood) compared to C57Br/cdJ, AKR/J, C57BL/6J, 129/J, BALB/cJ, DBA/2J, B10.D2/NSn, B10.D2/OSn and SJL/J(duration of 58–73 days, peak parasitaemia of 58–74 parasites/100 μl blood). Relative resistance to microfilariae was not related to the H-2 complex as determined in studies of congenic C3H.B10 (H-2^b) and B10.H-2^k mice and their background strains. This trait was inherited in a dominant fashion and involved a single or small number of genes. Serum anti-microfilarial antibodies reached highest levels in strains with a long duration compared to those with a short duration of parasitaemia (geometric mean titres of 1:13450 vs 1:284). The distribution of ^5lCr-labelled microfilariae among the livers, spleens, lungs and kidneys of a resistant (CBA/CaJ) and a susceptible (C57BL/6J) strain was similar. Transfer of immune lymphoid cells or sera between histocompatible (H-2^k) resistant CBA/CaJmice and susceptible C57Br/cdJ animals did not alter the duration of microfilaraemia.     

细胞毒作用杀伤周期型马来丝虫幼虫的超微结构研究

本文在特异性免疫血清存在下，就嗜中性粒细胞和巨噬细胞对周期型马来丝虫幼虫的细胞毒作用进行了超微结构观察。结果显示，两种效应细胞对虫体都具有强大的杀伤作用。该作用开始于效应细胞伸出伪足包围并粘附于虫体，然后分泌颗粒性物质、释放各种对虫体有毒性作用的酶和其它生物活性成分于虫体表面。由于微丝蚴鞘膜和角皮层的溶解和脱落，导致了虫体内部组织迅速变性坏死。电镜下可见虫体肿胀变形、核溶解和空泡样坏死以及最终崩解剥落成絮状等连续变化。本试验还发现效应细胞伪足插入脱鞘微丝蚴内部的现象，说明微丝蚴脱鞘后更易受到效应细胞的攻击。扫描电镜观察到被效应细胞粘附的感染期幼虫表面出现裂痕。     

Field validation of sensitivity and specificity of rapid test for detection of Brugia malayi infection

We conducted a field study of a rapid test (Brugia Rapid) for detection of Brugia malayi infection to validate its sensitivity and specificity under operational conditions. Seven districts in the state of Sarawak, Malaysia, which are endemic for brugian filariasis, were used to determine the test sensitivity. Determination of specificity was performed in another state in Malaysia (Bachok, Kelantan) which is non-endemic for filariasis but endemic for soil-transmitted helminths. In Sarawak both the rapid test and thick blood smear preparation were performed in the field. The rapid test was interpreted on site, whereas blood smears were taken to the district health centres for staining and microscopic examination. Sensitivity of Brugia Rapid dipstick as compared with microscopy of thick blood smears was 87% (20/23; 95% CI: 66.4-97.2) whereas the specificity was 100% (512/512). The lower sensitivity of the test in the field than in laboratory evaluations (> or =95%), was probably due to the small number of microfilaraemic individuals, in addition to difficulties in performing the test in remote villages by field personnel. The overall prevalence of brugian filariasis as determined by the dipstick is 9.4% (95% CI: 8.2-0.5) while that determined by microscopy is 0.90% (95% CI: 0.5-1.3) thus the dipstick detected about 10 times more cases than microscopy. Equal percentages of adults and children were found to be positive by the dipstick whereas microscopy showed that the number of infected children was seven times less than infected adults. The rapid dipstick test was useful as a diagnostic tool for mapping and certification phases of the lymphatic filariasis elimination programme in B. malayi-endemic areas.     

Injection of microfilariae induces resistance to Brugia malayi infection in ferrets and accelerates development of lymphostatic disease

Ferrets injected intravenously with living microfilariae or cutaneously with microfilariae followed by intravenous injection developed partial resistance to a challenge infection as measured by recovery of adult filariae from lymphatics. Following a challenge infection, the ferrets injected with microfilariae developed lymphatic pathology characteristic of a chronic infection or that observed following multiple infections. There was disruption of lymphatic drainage of the infected limb and lymphoedema. The results suggest that immune responses to antigens of microfilariae, presumably antigens shared with other developmental stages, effected both increased resistance and enhanced lymphatic pathology.     

Use of antifilarial IgG4-ELISA to detect Brugia malayi infection in an endemic area of Malaysia

Summary objective   To evaluate the usefulness of antifilarial IgG4 antibody assay in detecting B. malayi infection in a filaria endemic area in Malaysia. methods   A sandwich ELISA using B. malayi soluble antigen was employed to detect antifilarial IgG4 antibodies in serum samples of 330 individuals who comprised 88 healthy individuals from nonendemic areas, 15 B. malayi microfilaraemic cases, 22 individuals with soil-transmitted helminthiases, 9 elephantiasis cases and 196 residents from a B. malayi -endemic area. An O.D. value of > 0.420 at serum dilution of 1:400 was used as the cut-off point. This cut-off point was obtained by taking the mean optical density (0.252 + 4 S.E.) of 36 negative sera which had O.D. values greater than 0.1 at serum dilution of 1: 400. results   All 15 microfilaraemic persons were positive for antifilarial IgG4 antibody. Non-endemic normals, soil-transmitted helminth infected persons and chronic elephantiasis cases were negative for antifilarial IgG4 antibody. Of the 196 individuals from the filaria endemic area, 37 (18.8%) demonstrated presence of antifilarial IgG4 antibodies; and only eight individuals (4.1%) were positive for microfilariae. All eight microfilaraemic individuals were also positive for antifilarial IgG4 antibodies. conclusion   Antifilarial IgG4-ELISA could detect 4.6 times more positive cases than the microfilaria detection method. With appropriate cut-off values that eliminate cross-reactivities, this serological tool is very useful for Brugia malayi prevalence surveys and diagnosis.