摘要目的 观察仓鼠感染美洲钩虫第3期感染性幼虫(NaL3)后攻击感染NaL3时其皮肤组织病理改变以及NaL3的组织形态学变化,寻找仓鼠感染NaL3后对攻击感染NaL3的获得性免疫证据.方法 将仓鼠分为攻击感染组和对照组.攻击感染组仓鼠先经皮肤感染NaL3 150条,2周后与对照组同时感染NaL3 900条并于感染后6,24,72 h和1,2同时取感染部位皮肤,观察组织病理反应以及NaL3的组织形态变化.结果 对照组6,24,72 h和1,2周的NaL3的切面数分别为15,33,11,0,0个,其变性和死亡虫体切面数均为0个.所有虫体切面形态结构完整清晰,皮肤组织亦未出现明显的炎细胞反应.攻击感染组6,24,72 h和1,2周的NaL3的切面数分别为25,53,15,5,4个,变性虫体切面数为0,24,6,0,0个,死亡虫体切面数为0,0,7,5,4个.24 h起虫体角皮粗糙,肿胀,72 h虫体内部结构疏松,细胞核固缩,甚至模糊不清,1周后虫体切面遭明显破坏,隐约可见其残骸.皮肤组织内炎症反应主要有巨噬细胞,类上皮细胞和嗜酸性粒细胞浸润以及死虫肉芽肿形成.结论 仓鼠感染NaL3后埘攻击感染NaL3产生了抵抗力,其获得性免疫反应程度强烈.

abstractsObjective To obtain acquired immunity evidence in hamsters elicited by third stage hookworm larvae of Necator americanas(NaL3).morphology changes of NaL3 and inflammatory responses in the skin and undedying subcutaneous tissue and muscles of hamsters were observed.Methods Hamsters were immunized subcutaneously with one dose of 150 NaL3 at 2 weeks earlier,and then challenged pereutaneously with 900 NaL3.Skins were excised from post-challenge hamsters at 6,24,72 hours and 1,2 weeks,and then examined under light microscopy.Non-immunized hamsters served as negative controls.Results In non-immunized hamsters the number of NaL3 were 15,33,11.0 and 0 at 6,24,72 hours and 1,2 weeks post-infection.No damaged or dead NaL3 section was observed.All NaL3 exhibited no structural damage and infihrating inflammatory cells were absent from the sunDunding tissues.There were no cutaneous changes.In contrast.the total number of Nak sections in the skin of immunized hamsters were 25,53,15,5 and 4 at 6,24,72 hours and 1,2 weeks post-challenge.Among these NaL3 sections,damaged and dead section number were 0,24,6,0,0 and 0,0,7,5,4.At 24 hours post-challenge the Nak exhibited cutieular swelling and damage.By 72 hours post-challenge pyknosis of the somatic cells nuclei and sparseness or loss of definition in the internal structures of NaL3 were seen.One or two weeks after chanenge,the NaL3 showed severe damage or even dead with remnants.Inflammatory responses including macrophages,epithelioid cells and eosinophils infiltrating and granulomata forming were mainly seen around the NaL3 sections in the skin of immunized hamsters.Conclusions Hamsters initially immunized with NaL3 exhibited obvious acquired immunity protection against percutaneously challenged infection as evidenced by vigorous inflammatory responses in the skin and underlying subcutaneous tissue and muscle.