TY - CHAP M1 - Book, Section TI - Amyloidosis A1 - Seldin, David C. A1 - Berk, John L. A2 - Longo, Dan L. PY - 2016 T2 - Harrison's Hematology and Oncology, 3e AB - Amyloidosis is the term for a group of protein folding disorders characterized by the extracellular deposition of insoluble polymeric protein fibrils in tissues and organs. A robust cellular machinery exists to chaperone proteins during the process of synthesis and secretion, to ensure that they achieve correct tertiary conformation and function, and to eliminate proteins that misfold. However, genetic mutation, incorrect processing, and other factors may favor misfolding, with consequent loss of normal protein function and intracellular or extracellular aggregation. Many diseases, ranging from cystic fibrosis to Alzheimer’s disease, are now known to involve protein misfolding. In the amyloidoses, the aggregates are typically extracellular, and the misfolded protein subunits assume a common antiparallel, β-pleated sheet–rich structural conformation that leads to the formation of higher-order oligomers and then of fibrils with unique staining properties. The term amyloid was coined around 1854 by the pathologist Rudolf Virchow, who thought that these deposits resembled starch (Latin amylum) under the microscope. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/11/02 UR - accessbiomedicalscience.mhmedical.com/content.aspx?aid=1135227597 ER -