黄牛皮肤内圈形盘尾丝虫微丝蚴的昼夜规律及季节变化的观察

外周血液中的微丝蚴一般都有一定的昼夜周期和季节周期,然而皮肤组织中微丝蚴的周期性都不明显。在盘尾丝虫属中,据Mellor对马皮肤中(Onchocerca cervicalis)微丝蚴观察和Eichler对牛皮组织中(Onchocerca gutturosa)微丝蚴测定以及Marroquin(1974);Auderso(1975)对人体皮肤中(Onchocerca volvulus)微丝蚴的研究,都表明无周期节律,本丝虫的周期性尚无详细了解,特别是在中国还缺乏详细研究。我们于1984年2月至1985年     

液氮冻存丝虫微丝蚴成功的初报

液氮冻存丝虫微丝蚴的研究,国外有盘尾属丝虫、盂欧氏丝虫、斑氏丝虫、马来丝虫和犬恶丝虫等,国内尚未见有报道。本试验应用三种低温保护剂,对两种丝虫微丝蚴进行液氮低温保存的研究,获得初步成功,现简报如下:     

重庆市璧山县家犬的犬恶丝虫感染调查

犬恶丝虫（Ｄｉｒｏｆｉｌａｒｉａｉｍｍｉｔｉｓ）成虫寄生于宿主的心脏,其微丝蚴出没于周围血液中,家犬为其正常的宿主,偶有寄生于人体者。因工作需要,我们于１９９２年和１９９３年曾两次前往重庆市璧山县对家犬的犬恶丝虫感染进行调查。现将调查结果报告如下。１...     

长爪沙鼠实验感染周期型马来丝虫的继续观察

我组自1974年以来,曾先后采取腹腔和皮下途径,将周期型马来丝虫感染蚴接种长爪沙鼠,继而又采用移植法,将丝虫成虫和微丝蚴转入沙鼠腹腔,均获得成功。现已将马来丝虫在沙鼠体内传至第10代。本文主要报道1977年7月前的观察结果。此外,还简述1978年5月前丝虫传代和微丝蚴寿命观察等的部份情况。     

用FILAROCHEK预测犬恶丝虫虫荷的研究

由犬恶丝虫(Dirofilariaimmitis简称犬丝虫)引起的犬丝虫病,广泛流行于世界各地,对犬的危害殊重,人亦有受染。但有10—67%的感染犬,用浓集法查不到微丝蚴。自单克隆抗体技术用于寄生虫病的免疫诊断后,近年来,已有多种用单克隆抗体检测犬丝虫抗原的免疫试验用于临床或科研。Filarochek是1985年初生产的一种用单克隆抗体检测血清中犬丝虫表面抗原的酶联免疫吸附试剂。由于本试验的敏感性高达96.4%,特异性强,仅有1.9%的假阳性,已在美国广泛使用。但如何根据抗原的滴度来预测犬体内的虫荷,并进一步推测治疗的安全性尚未见报道。为此,将血清作等…     

马来丝虫微丝蚴低温保存及其后在中华按蚊体内继续发育的观察

低温保存微丝蚴,可为广泛深入开展丝虫和丝虫病的实验研究提供虫源,具有重要意义。近年来,由于冷冻技术的不断改进,采用多种冷冻保护剂及控制冷冻速度的方法,大大提高了微丝蚴冷冻后的活力。迄今,国外已有不少实验报道,经冷冻不同期后的微丝蚴仍能继续在相应的昆虫宿主体内发育到感染期幼虫即Ⅲ期蚴(Obiamiwe and Mac Donald,1971;Ham et al.,1979、1981;Miajas and Townson,1980;Lok et al.,1983;Lowrie,1983)。国内对微丝蚴低温保存的研究尚未见报道。我们于1983年9月份以来,对马来丝虫(Brugia malayi)微丝蚴进行了低温保存及其后活力的观察,初步结果简报于下:     

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。     

斑氏丝虫感染Scid小鼠模型的建立

采用人工感染法,对严重联合免疫缺陷小鼠(Scid 小鼠) 进行夜现周期性斑氏丝虫实验感染研究。结果表明,斑氏丝虫经人工感染后能在Scid 小鼠体内发育成熟并产生微丝蚴,且虫体回收率较高为6～30% ,平均14-8% 。感染的10 只小鼠均在外周血中检获出微丝蚴,及解剖收集到成虫,感染成功率高达100% 。作者认为Scid 小鼠由于T、B淋巴细胞功能缺如,不能产生相应的抗丝虫感染抗体,是一种易于感染成功、潜伏期短、微丝蚴密度及成虫回收率高的较理想的实验动物。     

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。     

福尔马林固定微丝蚴免疫酶染色试验检测丝虫抗体的初步观察

以马来丝虫微丝蚴为固相抗原,做免疫酶染色试验(IEST)检测丝虫病人血清抗体,具有较好的效果。但是,微丝蚴固相抗原在常温下极易腐败变质,影响了其在基层的推广应用。我们用福尔马林处理抗原后,在常温下保存60天,IEST的效果仍较满意。     

周期型马来丝虫微丝蚴寿命的观察

将实验感染周期型马来丝虫的长爪沙鼠的微丝蚴蚴阳性腹腔稀释液,移注于正常沙鼠腹腔内,微丝蚴除能在腹腔内长期生存外,还可出现于外周血液中,其在外周血液内末次阳性检出时间最长可超过32周,在腹腔液内末次阳性检出时间最长为77周,故马来微丝蚴在沙鼠外周血液中的最长寿命不短于7.5月,而在腹腔液内的最长寿命可超过1.5年以上。     

Oral transmission of Brugia pahangi and Dipetalonema viteae to adult and neonatal jirds

Sullivan J. J. and Chernin E. 1976. Oral transmission of Brugia pahangi and Dipetalonema viteae to adult and neonatal jirds. International Journal for Parasitology6: 75–78. Confirming previous studies, anaesthetized adult jirds became infected after oral doses of 100 infective larvae of B. pahangi; 4 of 5 jirds became microfilaria-positive and all 5 harbored adult worms. Among 7 unanaesthetized adult jirds similarly exposed, none developed microfilaraemia although 5 each harbored a few adult worms. In these unanaesthetized jirds, presumably, rapid passage of the inoculum through the mouth permitted fewer larvae to penetrate the mucosa, and the rest were probably killed in the stomach. Unanaesthetized 4-day old jirds proved highly and equally susceptible to oral or subcutaneous infection with B. pahangi as indicated by microfilaraemias and large worm-burdens. Direct and indirect evidence suggest that the baby's stomach and small intestine are not inimical to swallowed larvae, thus accounting for the relatively numerous mature worms in the peritoneal cavity. Third-stage larvae of D. viteae, readily infective subcutaneously, succeeded relatively infrequently in maturing when given orally to anaesthetized adult or to unanaesthetized baby jirds. Consistent oral infectivity may thus be a feature of filariae more closely related to B. pahangi.     

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.     

Brugia malayi and Brugia pahangi: transmission blocking activity of ivermectin and brugian filarial infections in Aedes aegypti

Brugia malayi- or Brugia pahangi-infected, microfilaremic jirds (Meriones unguiculatus) were treated with ivermectin at a single dose of 200 micrograms/kg body weight, administered subcutaneously. After different time intervals, Aedes aegypti mosquitoes were fed on treated or untreated jirds. Sausage stage, L2, and L3 larvae failed to develop in mosquitoes that fed on jirds from 15 to 30 days post-treatment. After 1 month, the numbers of L3 larvae recovered from mosquitoes fed on treated B. pahangi jirds were comparable to controls. However, the number of L3's recovered from mosquitoes fed on B. malayi jirds remained significantly lower than controls, 2 and 3 months after treatment. This reduction suggests that ivermectin may be more effective in blocking transmission of B. malayi than B. pahangi. Ivermectin treatment had no effect on the mean number of circulating microfilariae in treated jirds. Therefore, mosquitoes ingested comparable numbers of microfilariae when compared to those mosquitoes fed on untreated controls. Only in the case of jirds infected with B. malayi did the circulating microfilarial counts fall 30 days after treatment. The failure of microfilariae to develop to the L3 stage in mosquitoes fed on jirds within 30 days of treatment was not due to failure of mosquitoes to ingest microfilariae. Brugia malayi microfilariae also failed to develop to L3 in mosquitoes that were allowed to feed on microfilaremic jird blood treated with ivermectin (50 ng/ml) in vitro, indicating its efficacy at low concentrations. In addition to N-acetyl glucosamine, microfilariae obtained for a period of 15 days from ivermectin-treated but not control jirds showed D-mannose, N-acetyl galactosamine, and L-fucose moieties on the surface of the sheath.(ABSTRACT TRUNCATED AT 250 WORDS)     

Susceptibility of Psammomys obesus and Meriones tristrami to tachyzoites of Neospora caninum

The susceptibility of Psammomys obesus (sand rat) and Meriones tristrami (Tristram's jird) to Neospora caninum was investigated by subcutaneous (s.c.) and intraperitoneal (i.p.) inoculation of 10-fold doses of culture-derived tachyzoites. Groups of 5 animals were inoculated with doses of 10-10(7) parasites via each route of inoculation. All but 2 of the sand rats inoculated with doses of 10-10(4) parasites succumbed to the infection by 7-18 days postinfection. All jirds inoculated with 10(7) tachyzoites succumbed by 5-16 days postinfection and those inoculated with 10(6) tachyzoites by 9-25 days. A considerable proportion of the jirds inoculated with 10-10(5) tachyzoites survived. Fibrinous peritonitis with ascites containing numerous tachyzoites was observed in the i.p.-inoculated sand rats and jirds that succumbed to the infection. In the jirds, tachyzoites were also found in pleural exudate. A considerable number (42.8%) of the jirds inoculated s.c. or i.p. exhibited neuromuscular symptoms, expressed in ataxia, head tilt, circling movement, and posterior paralysis. Seven successive passage of tachyzoites were achieved in sand rats with doses of 10(5) parasites and in jirds with doses of 10(7) parasites. All surviving jirds became seroconverted and were immune to lethal challenge.     

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.     

Regulation of parasite antigen-induced T cell growth factor activity and proliferative responsiveness in Brugia pahangi-infected jirds

Previous studies have demonstrated that the induction of immunoregulatory mechanisms in the spleens of Brugia pahangi-infected jirds is correlated with the onset of microfilaremia. This study investigated the relationship between production of a factor with IL-2-like activity and the regulation of T cell-mediated responses in jirds experimentally infected with B. pahangi. A factor present in culture supernatants of mitogen-stimulated jird lymphocytes supported the proliferation of murine CTLL cells and provided the basis for an IL-2 assay. Mitogen induced proliferative responses and IL-2 production of spleen cells but not lymph node cells from pre-patent and microfilaremic jirds were suppressed. Both B. pahangi Ag-induced proliferative responsiveness and IL-2 production of spleen cells from microfilaremic jirds were also suppressed relative to lymph node cells from the same animals or spleen cells from B. pahangi immunized or prepatent jirds. Depletion of histamine receptor-bearing cells restored the ability of spleen cells from microfilaremic jirds to produce significant levels of IL-2. In addition, in add-mixture experiments, spleen cells from microfilaremic jirds suppressed Ag-induced IL-2 production by cells from either B. pahangi- or KHL-immunized jirds. Exogenous IL-2 failed to reconstitute the suppressed Ag-induced proliferative response of spleen cells from microfilaremic jirds. This study demonstrates that the down-regulation of immune responses in B. pahangi infection is a cell-mediated event and is associated with an inability to produce IL-2.     

从山东费县不同季节优势恙螨分离到恙虫病立克次体(英文)

对山东费县秋冬型恙虫病疫源地恙螨进行了调查并进行恙虫病立克次体（Ｒｔ）分离。从３５２只活鼠体外收集到１１ ７６２只恙螨,隶属２属５种,太平洋无前恙螨数量最多,占３６．７３％;其次是临淮岗纤恙螨（２４．０４％）;小盾纤恙螨（２１．６５％）;须纤恙螨（１３．５７％）和泰山纤恙螨（３．９６％）。小盾纤恙螨出现在９—１２月,高峰在１１月;须纤恙螨出现在１０月一翌年４月,高峰在１２月;临淮岗纤恙螨从５月到１１月存在,高峰在８月;太平洋无前恙螨出现在４—１２月,高峰在７月。从小盾纤恙螨、须纤恙螨、临淮岗纤恙螨及太平洋无前恙螨中共分离到１２株Ｒｔ,血清分型结果分离株以Ｇｉｌｌｉａｍ型为主,但存在Ｋａｒｐ型Ｒｔ。这些结果表明,上述４种恙螨均能自然感染Ｒｔ,有在该地区充作不同季节Ｒｔ传播媒介的可能。结合以往的研究结果,当地小盾纤恙螨集中出现于发病季节,其消长与当地人群发病基本一致,且能叮刺、经卵传递Ｒｔ,从而证实小盾纤恙螨是引起该地区秋冬型恙虫病流行的最重要的媒介。     

ISOLATION OF RICKETTSIA TSUTSUGAMUSHI FROM TROMBICULID MITES (ACARI:TROMBICULIDAE) IN FEIXIAN COUNTY, SHANDONG PROVINCE, CHINA

Abstract  Investigations on trombiculid mites and isolation of Rickettsia tsutsugamushi therefrom were carried out in Feixian County, Shandong Province. A total of 11 762 trombiculid mites, consisting of 5 species from two genera, were collected from 352 rodents (including 247 Apodemus agrarius , 80 Cricetulus triton , 23 Rattus noruegicus , 2 Crocidura suaveolens ), and Walchia pacifica was the most predominant (36.73%), followed by Leptotrombididium linhuaikonense (24.04%), L. scutellare (21.65%), L. palpale (13. 57%), and L. taishanium (3. 96%). L. scutellare was found from September to December with a remarkable peak in November, whereas L. palpale occurred from October to April (the second year) with peak in December. L. linhuaikonense was found from May to November, with peak in August. W. pacifica appeared from April to December with peak in July. R. tsutsugamushi was isolated from L. scutellare, L. palpale, L. linhuaikonense and W. pacifica . The main serotypes of R. tsutsugamushi isolated from the chigger mites were of the Gilliam type, but Karp type also existed in L. linhuaikonense . These results indicate that the surveyed area has a high probability of occurrence of tsutsugamushi disease, and L. scutellare, L. palpale, L. linhuaikonense and W. pacifica may serve as the vectors in this area. It is suggested that L. scutellare is the most important vector which has caused the endemic of this disease in Feixian County.     

布氏田鼠标志种群的繁殖参数

采用标志重捕和染色观测法跟踪了内蒙古典型草原区布氏田鼠野外种群,按绝对时间年龄研究其种群繁殖参数。结果3表明：4－5月份出生的雄鼠能在当年达到性成熟,性成熟发育历期约为1．5个月,6月后出生的雄鼠当年达不到性成熟。在达到性成熟的当年雄鼠中,多数个体再度转入性休止期,其平均繁殖结束时间要林越冬雄鼠早1个月,而越冬雄鼠则在整个繁殖期保持性活动状态。雌鼠性成熟发育历期约为1个月,首次产仔时间约为2月龄。雌鼠在一年中的产仔窝数与其年龄有关;越冬鼠能产3－4窝,4月份出生的雌鼠能产2－3窝,5月份出生的雌鼠当年能产1－2窝,6月份出生的雌鼠能产0－1窝,7月份之后出生雌鼠当年不参加繁殖,在自然条件下,布氏田鼠一年中最多能产4窝。