Aluminum: A naturally occurring element that makes up about 8% of the surface of the earth and is always found combined with other elements such as oxygen, silicon, and fluorine. Aluminum is the most common metallic element in the earth’s crust but has no clear biologic role. Everyone is exposed to low levels of aluminum from food, air, and water. Exposure to high levels of aluminum may result in respiratory problems (aluminosis). Inhalation of bauxite (aluminum ore) fumes may cause pulmonary fibrosis. Aluminum in the bloodstream may lead to neurological symptoms and may be fatal.
Aluminum toxicity may occur in people with renal insufficiency who are treated by dialysis with aluminum-contaminated solutions or oral agents that contain aluminum. The clinical manifestations of aluminum toxicity include anemia, bone disease, and progressive dementia with increased concentrations of aluminum in the brain. Prolonged intravenous feeding of preterm infants with solutions containing aluminum is associated with impaired neurologic development.
Aluminum metal is silver-white and flexible. It is often used in cooking utensils, containers, appliances, and building materials. It is also used in paints and fireworks; to produce glass, rubber, and ceramics; and in consumer products such as antacids, astringents, buffered aspirin, food additives, and antiperspirants.
Alveolar: Pertaining to the alveoli, the tiny air sacs in the lungs. The exchange of oxygen and carbon dioxide takes place in the alveoli which look like cells in a honeycomb. The word comes from the Latin diminutive of “alveus” meaning a cavity or hollow = a little cavity or hollow.
- Alveolar hydatid disease
Alveolar hydatid disease: Abbreviated AHD. A parasitic disease caused by the larval stage of a microscopic tapeworm Echinococcus multilocularis. AHD is found worldwide, mostly in northern latitudes. in central Europe, Russia, China, Central Asia, Japan, and North America. In North America E. multilocularis is found primarily in the north central region from eastern Montana to […]
Alveoli: The plural of alveolus. The alveoli are tiny air sacs within the lungs where the exchange of oxygen and carbon dioxide takes place.
- Alzheimer disease, early-onset familial
Alzheimer disease, early-onset familial: Alzheimer disease that runs in families and strikes at an unusually early age (with its onset under the age of 60). About 7% of early-onset cases of Alzheimer’s are familial and are inherited in an autosomal dominant manner with high penetrance. Mutations in three different genes — the amyloid precursor protein […]
- Alzheimer's disease
Alzheimer’s disease: A progressive degenerative disease of the brain that leads to dementia. On a cellular level, Alzheimer’s disease is characterized by the finding of unusual helical protein filaments in nerve cells of the brain. These twisted filaments are called neurofibrillary tangles. In the brain, Alzheimer’s disease involves degeneration of the cortical regions, especially the […]