Tajima Yuko, Shimada Akinori, Yamada Tadasu K, Cowan Daniel F
University of Texas Medical Branch, Galveston 77555-0555, USA.
J Zoo Wildl Med. 2007 Mar;38(1):108-13. doi: 10.1638/05-108.1.
Amyloidosis is a disease characterized by the tissue deposition of autologous extracellular fibrillar proteins that can result in compression of adjacent tissues. Amyloidosis is well-recognized in a wide variety of animals, including mammals, birds, and reptiles. However, to date, there is only one report of amyloidosis in cetaceans. During 1999 and 2000, among 12 Stejneger's beaked whales (Mesoplodon stejnegeri) that were stranded along the Sea of Japan's coast, amyloidosis was found in two whales (case 1, 498 cm, male; case 2, 520 cm, female). For this study population, the prevalence rate of amyloidosis was approximately 17%. These two animals were considered physically and sexually mature based on body length, external features, gonad characteristics, and skeletal features. Livers were notably swollen, fragile, and pale (brownish yellow) on gross examination. A large deposit of amyloid was found in Disse's spaces along with marked atrophy of the hepatocytes. Numerous granulomas, including many nematodes (Crassicauda sp.), were found along with amyloid deposition in the kidneys. Amyloid was also detected in the heart, spleen, adrenal gland, and pancreas. Amyloid in both cases was identified by typical morphology on H&E and Congo red staining. Electron microscopy displayed a typical network of fine fibrils measuring about 11 nm in diameter. This is the first report of amyloidosis in two Stejneger's beaked whales stranded on the coast of the Sea of Japan.
淀粉样变是一种以自体细胞外纤维状蛋白在组织中沉积为特征的疾病，可导致相邻组织受压。淀粉样变在包括哺乳动物、鸟类和爬行动物在内的多种动物中都有广泛报道。然而，迄今为止，关于鲸类动物淀粉样变的报道仅有一例。在1999年至2000年期间，在日本海沿岸搁浅的12头斯氏喙鲸（Mesoplodon stejnegeri）中，有两头鲸（病例1，体长498厘米，雄性；病例2，体长520厘米，雌性）被发现患有淀粉样变。对于该研究群体，淀粉样变的患病率约为17%。根据体长、外部特征、性腺特征和骨骼特征，这两头动物被认为已达到生理和性成熟。大体检查时，肝脏明显肿大、脆弱且颜色苍白（棕黄色）。在狄氏间隙发现大量淀粉样沉积物，同时肝细胞明显萎缩。在肾脏中发现大量肉芽肿，包括许多线虫（Crassicauda sp.），同时伴有淀粉样沉积。在心脏、脾脏、肾上腺和胰腺中也检测到淀粉样物质。通过苏木精-伊红染色和刚果红染色的典型形态学特征，确定了两例中的淀粉样物质。电子显微镜显示出典型的直径约为11纳米的细纤维网络。这是关于在日本海沿岸搁浅的两头斯氏喙鲸发生淀粉样变的首次报道。
