Baylisascaris procyonis–Associated Meningoencephalitis in a Previously Healthy Adult,California, USA

After severe neurocognitive decline developed in an otherwise healthy 63-year-old man, brain magnetic resonance imaging showed eosinophilic meningoencephalitis and enhancing lesions. The patient tested positive for antibodies to Baylisascaris spp. roundworms, was treated with albendazole and dexamethasone, and showed improvement after 3 months. Baylisascariasis should be considered for all patients with eosinophilic meningitis.     

Formalin-induced infidelity in PCR-amplified DNA fragments

A 643-nucleotide-long fragment of rDNA gene was amplified by PCR in the nematode worm Caenorhabditis. When the experiments were performed by using samples fixed in formalin, artefacts were detected. While the size of the amplified fragment resulted unaffected, very striking differences were seen in the nucleotide sequences of the amplified fragments. Furthermore, in many cases, the PCR reaction failed completely. The results obtained might warn of potential problems, especially when the amount of DNA to be amplified scarce.     

陕北农村地区居民土源性线虫感染调查分析

目的 了解陕北农村居民土源性线虫感染现状、土源性线虫病防治知识知晓及健康行为形成情况.方法 按照随机抽样法,选择8个村作为调查点,以调查点≥3岁的常住人口为调查对象.采用改良加藤厚涂片法检测调查对象粪便中蛔虫、钩虫、鞭虫虫卵,12周岁以下儿童以透明胶纸法检测蛲虫卵.在每个调查点随机抽取8户以上的家庭,对家庭成员进行土源性线虫病防治知识知晓情况及卫生行为调查.结果 共粪检1 352人,阳性4人,土源性线虫总感染率为0.29％;蛲虫感染检测108人,阳性11人,蛲虫感染率为10.18％;入户调查329人,土源性线虫病防治知识知晓率为38.29％,62％以上的调查者有良好卫生行为.结论 陕北农村居民土源性线虫感染率较低,但儿童蛲虫感染率较高;人群卫生行为较好,但防治知识知晓率偏低.应继续加强防治工作,促进健康教育,以有效降低该病的危害.     

Local immune responses in sensitized sheep following challenge infection with Teladorsagia circumcincta

Sheep were sensitized by weekly infections with Teladorsagia circumcincta over a 9-week period. After a 12-week rest, sheep were divided into four groups and killed without challenge or 3, 5 and 10 days post challenge (DPC) with 50000 L3. Recovery of challenge larvae from abomasal scrapings was highest at 3 DPC while no parasites were recovered by 10 DPC. Abomasal lymph nodes (ALN) of challenged sheep were significantly larger at 5 DPC, coinciding with an increase in the proportion of CD4 T cells and a decrease in CD21+ cells, probably reflecting the loss of CD21 from terminally differentiated antibody secreting cells. A significant increase was observed in gammadelta-TCR+ cells at 3 DPC in the ALN, while their number slightly decreased in the abomasal tissues throughout the challenge period. The number of tissue eosinophils was dramatically increased after challenge compared with the unchallenged controls, with a peak at 3 DPC, coinciding with the peak in larval recovery. CD4+ cells significantly increased in the abomasal tissues at 5 DPC, while no changes in globule leucocytes were observed until 10 DPC. Antibody-secreting cell probes (ASC-probes) generated from the ALN showed highest reactivity against larval antigens at 5 DPC. This reactivity was predominantly directed against regions between 90 and 100 kDa and 30-35 kDa in the L3 preparation and lower molecular weight antigens in the L4. No reactivity was observed against the adult extract. The 30-35 kDa antigen seemed to exist as a high molecular weight complex in L3 homogenate and was not susceptible to protease K treatment, suggesting it may be non-protein in nature.     

复方阿苯达唑驱除肠道线虫的现场观察

目的：观察复方阿苯达唑（每片含阿苯达唑６７ｍｇ和噻嘧啶８３．３ｍｇ基质）的驱虫效果。方法：对成人钩虫感染者１８６４例、蛔虫感染者１５６８例和鞭虫感染者１７８５例及儿童蛲虫感染者３７３例，随机分组，比较服用单剂复方阿苯达唑３片或２片与单剂阿苯达唑４００ｍｇ或噻嘧啶３０ｍｇ（含基质１０ｍｇ）／ｋｇ的驱虫效果和副作用。结果：成人复方阿苯达唑３片和２片的虫卵阴转率，钩虫分别为６５．０％和５２．７％（Ｐ＜０．０１），蛔虫均为１００％，鞭虫分别为２６．５％和１９．２％（Ｐ＜０．０１）。３片的驱钩虫效果显著优于阿苯达唑和噻嘧啶组（Ｐ均＜０．０１）。２片的驱钩虫效果亦优于噻嘧啶（Ｐ＜０．０１），与阿苯达唑无显著性差异，但驱鞭虫效果低于阿苯达唑。２－６岁儿童服复方阿苯达唑１．５片的，蛲虫卵阴转率为１００％，显著优于噻嘧啶（Ｐ＜０．０１）。复方阿苯达唑的驱虫作用快速，副作用轻，对血象、肝肾功能和心电图无显著影响。结论：复方阿苯达唑具有阿苯达唑和噻嘧啶两药的协同作用。     

荧光定量PCR检测异尖线虫类病原体

目的运用荧光定量PCR法检测异尖线虫类病原体。方法于鱼类内脏中检获6种异尖线虫类幼虫:抹香鲸异尖线虫、简单异尖线虫、内弯对盲囊线虫、带鱼针蛔线虫、灰海鳗对盲囊线虫和台湾海峡鱼类中一优势种对盲囊线虫。提取各虫体DNA,PCR扩增ITS-2序列,测序并进行数据库比对。依据测序结果设计特异引物,常规PCR检验引物特异性。将ITS-2序列扩增产物回收、纯化后经T克隆转入大肠埃希菌DH5α,提取重组质粒,鉴定后作为标准品模板建立荧光定量PCR标准曲线,并做敏感性和重复性试验。结果构建的荧光定量PCR标准曲线循环阈值与模板浓度呈良好的线性关系,相关系数均在0.998以上。重复性实验中,6种虫体对应的变异系数(cv)最小值为0.18%,最大值为2.80%,试验间平均cv最小值为0.55%,最大值为1.94%,无非特异性扩增,溶解曲线的特异性和重复性良好。灵敏度实验中,可检出的最低模板浓度为1×102拷贝/μl,比常规PCR灵敏度高100倍。结论初步建立了SYBRGreenⅠ荧光定量PCR检测异尖线虫类病原体的方法 。     

Towards a differential definition of atopy: Anisakis simplex and the relationship between parasites and arthropods in respiratory allergy

Protective as well as enhancing effects of parasite infections on allergic disease have been postulated. Previous studies on this relationship focused frequently on skin test reactivity against aeroallergens, being house dust mites (HDM) the main agents responsible for a positive atopy outcome.
We aimed to analyse the possible relationship between human parasite infection induced Anisakis simplex urticaria and respiratory allergy.
A total of 86 patients with gastro-allergic Anisakiasis and 203 patients with chronic urticaria sensitized against A. simplex were studied for sensitization against aeroallergens and evaluated for rhinoconjunctivitis or bronchial asthma (RCBA). We compared the results with a control group of 250 consecutive patients referred for evaluation of allergic RCBA and atopy prevalence data of our region.
Whereas no effect of A. simplex related disease on the overall allergic respiratory disease could be detected, a highly significant higher prevalence of RCBA associated HDM sensitization, but diminished allergy against other common aeroallergens (pollen, mould or dander) was observed in these groups.
The relationship between A. simplex parasitism-associated acute or chronic urticaria on one side and allergic respiratory disease on the other side depends on the definition of atopy. We propose a differential definition of atopy, with a special emphasis on arthropod related sensitization.     

Protection in lambs vaccinated with Haemonchus contortus antigens is age related, and correlates with IgE rather than IgG1 antibody

The involvement of mucosal mast cells (MMC) in protection against infection with the murine nematode parasite Trichuris muris was studied in genetically mast cell-deficient WBB6F1-W/Wv mice and their normal littermates WBB6F1-+/+ mice. Expulsion of T. muris worms occurred in infected +/+ mice, whereas no worm expulsion was observed in infected W/Wv mice where the infection persisted until at least day 46 postinfection. No MMC responses were induced in either infected W/Wv or +/+ mice. Specific IgG1and IgG2a antibodies to T. muris excretory/secretory antigens were observed in infected W/Wv and +/+ mice, and antibody production showed similar kinetics. Interleukin 4 production by concanavalin A (Con A)-stimulated mesenteric lymph node cells (MLNC) was induced preferentially in infected +/+ mice. T. muris infection increased the levels of IFN-gamma produced by Con A-stimulated MLNC of infected W/Wv and +/+ mice, with the levels of IFN-gamma in infected W/Wv mice being higher than those in infected +/+ mice. Taken together, these results indicate that W/Wv and +/+ mice are susceptible and resistant to T. muris infection, respectively, and that MMC responses are not required for protective immunity.     

南宁市郊农村居民土源性线虫感染状况调查

目的了解广西南宁市郊土源性线虫感染现况。方法采用随机抽样法选取调查对象,采用改良加藤法检查虫卵。应用SPSS16.0软件分析资料。结果调查居民共884人,其中男性514人,女性370人,平均年龄为38.48岁。土源性线虫总感染率为5.20%。鞭虫和钩虫感染率分别为0.57%和4.64%,两种虫的感染差异有统计学意义。男、女性钩虫感染率为4.67%和4.60%。男、女性鞭虫感染率为0.58%和0.57%,男女感染差异无统计学意义。从地区分布看,横县和宾阳县居民钩虫感染者相对较多,感染率分别为14.19%和12.4%;上林县鞭虫感染者相对较多,感染率为2.99%。从年龄分布上看,钩虫在30~50岁年龄组有更高的感染率。本次调查结果与2002~2004年调查结果相比,土源性线虫感染率大幅度下降,尤其是蛔虫感染率降至0。结论南宁市郊居民的土源性线虫感染率较低,主要以钩虫和鞭虫感染为主,未发现蛔虫感染者。