肺炎链球菌致坏死性肺炎患儿肺泡Ⅱ型上皮细胞超微结构的变化

摘要

Objective To study the microanatomical changes in alveolar epithelial cells type Ⅱ ( AEC- Ⅱ ) in the lung tissue of a 9 year-old girl infected by Streptoccus pneumoniae ( Sp) .Methods Normal and ahnormal lung samples ( 1 mm3 ) were obtained from the excised left lower lobe which contained the huge necrotized cavity caused hy Sp infection after the girl had been diagnosed as pneumococcal necrotizing pneumonia 4 months later. Specimens were kept in 2.5％ glutaraldehyde and stored at 4 ℃.Transmission electron microscope was employed for the examination.Results The number of microvilli on the surface of AEC- Ⅱ infected by Sp reduced significantly.The volume of Lamellar bodies increased with enhanced emptying.The chromatin concentrated with inhomogeneous distribution.Parts of the lung tissue became fibrosis.Conclusion The injuries of AEC- Ⅱ infected by Sp may lead to the necrosis and fibrosis of lung tissue.%目的 研究致1例9岁患儿肺组织坏死的肺炎链球菌(Sp)对该患儿肺泡Ⅱ型上皮细胞(AEC-Ⅱ)超微结构的影响.方法 肺炎链球菌坏死性肺炎患儿因肺空洞较大,且反复感染,4个月后行左下肺叶肺空洞切除时,将坏死和正常的肺组织标本(1 mm3)置于2.5%的戊二醛中固定.所有标本置于4℃冰箱中待检.用透射电子显微镜观察儿童AEC-Ⅱ超微结构的变化.结果 在Sp作用下儿童AEC-Ⅱ的微绒毛减少,脱落.板层小体体积增大,排宅加强,密度减低.细胞核染色质浓缩,分布不均,部分肺组织呈纤维化样改变.结论 Sp作用下儿童AEC-Ⅱ的损伤可能导致肺组织坏死和纤维化.