儿科
词汇介绍
拓展阅读
解析
toxoplasmosis 英 /,tɒksəʊplæz'məʊsɪs/ 美 /,tɑksoplæz'mosɪs/
释 义 n. [内科] 弓形体病,弓浆虫病
例 句 Cats can carry a disease called toxoplasmosis, which can be contracted by coming into contact with their waste products. 猫携带一种被称作弓浆虫病的疾病,可能因为接触他们的排泄物而感染。
概述
概述
弓形虫病是由刚地弓形虫引起的人畜共患病。该病原广泛存在于自然界,几乎所有哺乳动物和人及某些鸟类都是中间宿主,猫科动物是其唯一的终宿主。成人弓形虫感染大多为亚临床感染。经胎盘传播引起胎儿先天性弓形虫感染者,其孕母几乎均为原发性感染,母亲慢性感染引起的先天性感染罕见,弓形虫病经胎盘传播率约为40%,且传播率随胎龄增大而增加,但胎儿感染严重程度随胎龄增大而减轻。
传播途径
①经食物传染;②猫粪传染;③土壤污染和昆虫机械传染;④先天性感染。
临床表现
① 全身症状:早产、宫内生长迟缓、黄疸、肝脾肿大、皮肤紫癜、皮疹、发热或体温不稳、肺炎、心肌炎、肾炎、淋巴结肿大等。
② 中枢神经系统:可出现脑膜脑炎的症状和体征,如前囟隆起、抽搐、角弓反张、昏迷等。脑脊液常有异常表现为淋巴细胞增多、蛋白质增高、糖减少。头颅CT示阻塞性脑积水、脑皮质钙化等。脑积水有时是先天性弓形虫感染的唯一表现。可发生在出生时或出生后逐渐发生。
③ 眼部病变:脉络膜视网膜炎最常见,一侧或双侧眼球受累,还可见小眼球、无眼球等,是引起儿童视力受损的最常见病因之一。
诊断
① 病原检查:取血、体液或淋巴结,直接涂片或接种组织细胞培养找病原体。但该方法操作复杂,阳性率低。
② 抗体检测:ELISA检测血清弓形虫IgG、lgM,该方法敏感性高,特异性强;聚合酶链反应(PCR)检测血或胎儿羊水弓形虫DNA,后者阳性提示胎儿宫内感染。
治疗
弓形虫病并不总是需要治疗,特别是在健康个体中。然而,在某些情况下,例如孕妇或免疫功能低下者,可建议使用药物来降低弓形虫感染的严重程度。
弓形虫ROP16激酶通过劫持宿主细胞UHRF1-dependent表观遗传途径沉默细胞周期蛋白B1基因启动子
发表时间:2019-09-06
影响指数:7.0
作者: Sabou Marcela
期刊:Cell Mol Life Sci
Toxoplasmosis, caused by the apicomplexan parasite Toxoplasma gondii, is one of the most common infections in the world due to the lifelong persistence of this parasite in a latent stage. This parasite hijacks host signaling pathways through epigenetic mechanisms which converge on key nuclear proteins. Here, we report a new parasite persistence strategy involving T. gondii rhoptry protein ROP16 secreted early during invasion, which targets the transcription factor UHRF1 (ubiquitin-like containing PHD and RING fingers domain 1), and leads to host cell cycle arrest. This is mediated by DNMT activity and chromatin remodeling at the cyclin B1 gene promoter through recruitment of phosphorylated UHRF1 associated with a repressive multienzymatic protein complex. This leads to deacetylation and methylation of histone H3 surrounding the cyclin B1 promoter to epigenetically silence its transcriptional activity. Moreover, T. gondii infection causes DNA hypermethylation in its host cell, by upregulation of DNMTs.
译文