Rehm S, Waalkes M P, Ward J M
Tumor Pathology and Pathogenesis Section, National Cancer Institute, Frederick, MD 21701.
Lab Anim Sci. 1988 Apr;38(2):162-6.
In two separate 24 month studies on the carcinogenic effect of single cadmium chloride injections in male Wistar (CRl:(WI)BR) rats, a total of 22% (129/597) of animals studied histologically were found to have chronic suppurative rhinitis caused by Aspergillus fumigatus. The diagnosis was based on characteristic conidial heads present in the sections, and positive methenamine-Grocott (GMS) staining of septate hyphae with dichotomous branching at angles of 45 degrees. Fungal hyphae balls, surrounded by a wall of neutrophilic granulocytes, were found in areas of the naso- and maxilloturbinates and occasionally caused complete blockage of the nasal passages. The underlying tissue showed an inflammatory response. In sections from 32 of the 129 cases (25% of the cases), epithelial necrosis and hemorrhage were indicative of fungal tissue invasion, but without dissemination to other organs. The infection rate was unaffected by the cadmium treatment or the location of rats in different cages. Positive antibody titers to Sendai and sialodacryoadenitis viruses suggested that transient inflammation of the upper respiratory tract rendered the mucosa susceptible to the fungal infection. The infection appeared to be sustained by growth around foreign bodies (hairs and plant material). Although focal squamous cell metaplasia of the respiratory epithelium with hyperplasia and hyperkeratosis occurred more frequently in rats with Aspergillus rhinitis, the incidence of tumors of the nasal cavities was not affected.
在两项分别为期24个月、关于单次注射氯化镉对雄性Wistar（CRl:(WI)BR）大鼠致癌作用的研究中，经组织学检查，总共22%（129/597）的实验动物被发现患有由烟曲霉引起的慢性化脓性鼻炎。诊断依据是切片中存在特征性的分生孢子头，以及间隔菌丝在45度角处呈二叉状分支的六胺银（GMS）染色阳性。在鼻甲骨和上颌鼻甲区域发现了被嗜中性粒细胞壁包围的真菌菌丝球，偶尔会导致鼻道完全堵塞。其下方组织呈现出炎症反应。在129例中的32例（占病例的25%）切片中，上皮坏死和出血表明真菌组织有侵袭，但未扩散到其他器官。感染率不受镉处理或大鼠在不同笼子中的位置影响。针对仙台病毒和涎泪腺炎病毒的阳性抗体滴度表明，上呼吸道的短暂炎症使黏膜易受真菌感染。感染似乎是由异物（毛发和植物材料）周围的生长所维持。虽然在患有曲霉性鼻炎的大鼠中，呼吸道上皮的局灶性鳞状上皮化生伴增生和角化过度更为常见，但鼻腔肿瘤的发生率并未受到影响。
