A group of proteins that are constituents of lipoproteins, the carriers of fat in the bloodstream. Apolipoproteins are also involved in the growth and repair of nerve tissues.
n. any one of a family of proteins that form the protein components of *lipoproteins, which transport hydrophobic lipid molecules in the plasma. Individual members of the family are designated by the abbreviation ‘Apo’ followed by a capital letter. Apolipoproteins have a range of molecular weights and perform a variety of functions during the life cycle of the lipoproteins in which they are found. These include acting as ligands for the binding of enzymes (ApoB) and as cofactors for the action of other enzymes (ApoA and ApoC).
A progressive condition in which nerve cells in the brain degenerate and the brain shrinks. Alzheimer’s disease is the most common cause of dementia. Onset is uncommon before the age of 60.
Early onset Alzheimer’s disease, in which symptoms develop before age 60, is inherited as a dominant disorder. Late onset Alzheimer’s disease is associated with a number of genes, including 3 that
are responsible for the production of the blood protein apolipoprotein E. These genes also result in the deposition of a protein called beta amyloid in the brain. Other chemical abnormalities may include deficiency of the neurotransmitter acetylcholine.
The features of Alzheimer’s disease vary, but there are 3 broad stages. At first, the person becomes increasingly forgetful, and problems with memory may cause anxiety and depression. In the 2nd stage, loss of memory, particularly for recent events, gradually becomes more severe, and there may be disorientation as to time or place. The person’s concentration and numerical ability decline, and there is noticeable dysphasia (inability to find the right word). Anxiety increases, mood changes are unpredictable, and personality changes may occur. Finally, confusion becomes profound. There may be symptoms of psychosis, such as hallucinations and delusions. Signs of nervous system disease, such as abnormal reflexes and faecal or urinary incontinence, begin to develop.
Alzheimer’s disease is usually diagnosed from the symptoms, but tests including blood tests and CT scanning or MRI of the brain may be needed to exclude treatable causes of dementia.
The most important aspect of treatment for Alzheimer’s disease is the provision of suitable nursing and social care for sufferers and support for their relatives. Tranquillizer drugs can often improve difficult behaviour and help with sleep. Treatment with drugs such as donepezil and rivastigmine may slow the progress of the disease for a time, but side effects such as nausea and dizziness may occur.... alzheimer’s disease
n. one of a group of compounds, found in blood plasma and lymph, each consisting of a protein (see apolipoprotein) combined with a lipid (which may be cholesterol, a triglyceride, or a phospholipid). Lipoproteins are important for the transport of lipids in the blood and lymph (see also lipoprotein lipase). See chylomicron; high-density lipoprotein; low-density lipoprotein; very low-density lipoprotein. See also hyperlipidaemia.... lipoprotein
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