Nonomura N, Giebink G S, Zelterman D, Harada T, Juhn S K
Department of Otolaryngology, School of Medicine, University of Minnesota, Minneapolis.
Ann Otol Rhinol Laryngol. 1991 Jul;100(7):593-6. doi: 10.1177/000348949110000715.
Middle ear infection with Streptococcus pneumoniae is important in the pathogenesis of acute and chronic otitis media, and lysozyme in middle ear fluid (MEF) is an important inflammatory mediator in this disease. To determine the source of lysozyme during the early period of acute pneumococcal otitis media, chinchillas were irradiated to induce neutropenia, and their middle ears were inoculated with heat-killed, encapsulated pneumococci. The number of inflammatory cells and concentration of lysozyme were measured in MEF between 6 and 72 hours after inoculation. In pneumococcus-inoculated ears, the mean number of inflammatory cells but not lysozyme was significantly lower in MEF from irradiated animals than that from nonirradiated animals at 6 hours. Since lysozyme accumulated in MEF before the influx of inflammatory cells in irradiated animals, the initial release of this inflammatory mediator is most likely not from inflammatory cells; and mucosal epithelial cells, the only other known source of lysozyme in the middle ear environment, were the probable source induced by the direct stimulation of pneumococci. Inflammatory cells may contribute lysozyme later in the inflammatory response, since cellular and lysozyme concentrations in irradiated and nonirradiated animals were similar between 24 and 72 hours. These results suggest that future therapeutic interventions to limit middle ear inflammation in acute otitis media may need to recognize the direct action of pneumococcal cells or their envelope components on middle ear epithelium.
肺炎链球菌引起的中耳感染在急慢性中耳炎的发病机制中具有重要作用，中耳积液（MEF）中的溶菌酶是该疾病中一种重要的炎症介质。为了确定急性肺炎球菌性中耳炎早期溶菌酶的来源，对栗鼠进行照射以诱导中性粒细胞减少，然后向它们的中耳接种热灭活的、有荚膜的肺炎球菌。在接种后6至72小时测量中耳积液中的炎症细胞数量和溶菌酶浓度。在接种肺炎球菌的耳朵中，照射动物的中耳积液中炎症细胞的平均数量在6小时时显著低于未照射动物，但溶菌酶的平均数量并非如此。由于在照射动物中，溶菌酶在炎症细胞流入之前就在中耳积液中积累，因此这种炎症介质的初始释放很可能并非来自炎症细胞；而中耳环境中溶菌酶的唯一其他已知来源——黏膜上皮细胞，很可能是由肺炎球菌的直接刺激所诱导的来源。炎症细胞可能在炎症反应后期才会释放溶菌酶，因为在24至72小时之间，照射动物和未照射动物的细胞和溶菌酶浓度相似。这些结果表明，未来旨在限制急性中耳炎中耳炎症的治疗干预措施可能需要认识到肺炎球菌细胞或其包膜成分对中耳上皮的直接作用。
