|
 |
||
 |
| This glossary contains: 19186 medical terms |
 |
Alexander disease
|
|
Alexander diseaseA slowly progressive and ultimately fatal brain disorder that most commonly occurs in children. The infantile form of the disease is characterized by megalencephaly (an abnormally large head), seizures, spasticity and developmental retardation. It leads to death usually within the first decade. Patients with the juvenile and adult forms of Alexander disease typically experience ataxia and spasticity and a more slowly progressive course. The classic hallmark of all forms of Alexander disease is the presence of Rosenthal fibers, abnormal inclusions in astrocytes that contain the intermediate filament protein GFAP. Mutations in the gene for GFAP (glial fibrillary acidic protein) cause Alexander disease, the first known example of a primary genetic disorder of astrocytes, one of the major cell types in the vertebrate CNS. The disease was first described by W. Stewart Alexander, a New Zealand pathologist, in 1949.
RELATED TERMS--------------------------------------
Brain
"That part of the central nervous system that is located within the cranium (skull). The brain functions as the primary receiver, organizer and distributor of information for the body. It has two (right and left) halves called ""hemispheres."" "
Disease
Illness or sickness often characterized by typical patient problems (symptoms) and physical findings (signs). Disruption sequence: The events that occur when a fetus that is developing normally is subjected to a destructive agent such as the rubella (German measles) virus.
Spasticity
Involuntary muscle tightness and stiffness that occurs in about two-thirds of people with cerebral palsy and in many who suffer severe head injuries. The medical definition of dystonia is a velocity-dependent, increased resistance to passive muscle stretch. In other words, when a muscle affected by spasticity is stretched by someone else, it is harder to move the muscle than normal, and the faster one pushes, the harder the muscle is to move.
Retardation
Delay or halt of any process such as mental or physical development.
Death
1. The end of life. The cessation of life. (These common definitions of death ultimately depend upon the definition of life, upon which there is no consensus.) 2. The permanent cessation of all vital bodily functions. (This definition depends upon the definition of "vital bodily functions.") See: Vital bodily functions. 3. The common law standard for determining death is the cessation of all vital functions, traditionally demonstrated by "an absence of spontaneous respiratory and cardiac functions." 4. The uniform determination of death.
Ataxia
Ataxia is unsteady and clumsy motion of the limbs or trunk due to a failure of the fine coordination of muscle movements. The cerebellum is the center of the fine coordination of muscle movements, while the information emerging from it is carried to the muscles by the spinal cord and peripheral nerves, respectively. Therefore a disorder in either the spinal cord or in the peripheral nerves can cause ataxia.
Abnormal
Not normal. Deviating from the usual structure, position, condition, or behavior. In referring to a growth, abnormal may mean that it is cancerous or premalignant (likely to become cancer).
Protein
Any of a group of complex organic compounds which contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur, the characteristic element being nitrogen. Proteins, the principal constituents of the protoplasm of all cells, are of high molecular weight and consist essentially of combinations of a-amino acids in peptide linkages. Twenty different amino acids are commonly found in proteins, and each protein has a unique genetically defined amino acid sequence which determines its specific shape and function. Their roles include enzymatic catalysis, transport and storage, coordinated motion, nerve impulse generation and many others.
GFAP
Glial fibrillary acidic protein. The degenerative brain condition called Alexander disease is caused by mutation in GFAP (glial fibrillary acidic protein). The GFAP gene provides instructions for making GFAP protein, a member of the intermediate filament family that provides support and strength to cells. Several molecules of GFAP protein bind together to form the main intermediate filament found in specialized brain cells called astrocytes. Astrocytes are star-shaped cells that support the functions of nerve cells in the brain and spinal cord (central nervous system). If the central nervous system is injured through trauma or disease, astrocytes react by rapidly producing more GFAP.
Gene
1. A unit of DNA that carries information for the biosynthesis of a specific product in the cell. 2. Ultimate unit by which inheritable characteristics are transmitted to succeeding generations in all living organisms. Genes are contained by, and arranged along the length of, the chromosome. The gene is composed of deoxyribonucleic acid (DNA). Each chromosome of each species has a definite number and arrangement of genes, which govern both the structure and metabolic functions of the cells and thus of the entire organism.
Genetic
Hereditary. Having to do with the genes.
Cell
Fundamental structural unit of all life. The cell consists primarily of an outer plasma membrane, which separates it from the environment; the genetic material (DNA), which encodes heritable information for the maintainance of life; and the cytoplasm, a heterogeneous assemblage of ions, molecules, and fluid.
CNS
see Central Nervous System.
Pathologist
A physician trained in the nature, cause, process and effects of disease; examines samples of tissue removed during surgery to determine an exact diagnosis.
SIMILAR TERMS--------------------------------------
Alexia
Loss of a previously intact ability to grasp the meaning of written or printed words and sentences.
Alexian Brothers Medical Center
Alexian Brothers Medical Center is a hospital in Elk Grove Village, Illinois (USA).
Alexithymia
A disturbance in affective and cognitive function that can be present in an assortment of diagnostic entities. Is common in psychosomatic disorders, addictive disorders, and posttraumatic stress disorder. The chief manifestations are difficulty in describing or recognizing one's own emotions, a limited fantasy life, and general constriction in affective life.
PREVIOUS AND NEXT TERMS--------------------------------------
Aldrin
See: Aldrin and dieldrin.
Aldrin and dieldrin
The common names of two structurally similar compounds that were once used as insecticides. They are chemicals that are made in the laboratory and do not occur naturally in the environment.
Aleut health
See: Artic health.
Aleve
See: Naproxen.
Alexander disease
Algia
Word ending indicating pain, as in arthralgia (joint pain), cephalgia (headache), fibromyalgia, mastalgia (breast pain), myalgia (muscle pain), and neuralgia (nerve pain). Derived from the Greek algos meaning pain.
Alice Stewart
See: Stewart, Alice.
Alkaline phosphatase
An enzyme made in the liver, bone, and the placenta and normally present in high concentrations in growing bone and in bile. Alkaline phosphatase is released into the blood during injury and during such normal activities as bone growth and pregnancy. It is measured in a routine blood test. Abnormally high blood levels of alkaline phosphatase may indicate disease in bone or liver, bile duct obstruction, or certain malignancies. The enzyme is often elevated in the leukemic cells in chronic myelogenous leukemia. Abnormally low levels of alkaline phosphatase is a genetic condition called hypophosphatasia which results in bone deformities. The enzyme is termed alkaline phosphatase because it works under alkaline (non-acidic) conditions, as opposed to acid phosphatase.
Alkaloid
A member of a large group of chemicals that are made by plants and have nitrogen in them. Many alkaloids possess potent pharmacologic effects. The alkaloids include cocaine, nicotine, strychnine, piperine, caffeine, morphine, pilocarpine, atropine, methamphetamine, mescaline, ephedrine, and tryptamine.
Alkaloid, vinca
See: Vinca alkaloid.
RELATED TERMS--------------------------------------
Brain
"That part of the central nervous system that is located within the cranium (skull). The brain functions as the primary receiver, organizer and distributor of information for the body. It has two (right and left) halves called ""hemispheres."" "
Disease
Illness or sickness often characterized by typical patient problems (symptoms) and physical findings (signs). Disruption sequence: The events that occur when a fetus that is developing normally is subjected to a destructive agent such as the rubella (German measles) virus.
Spasticity
Involuntary muscle tightness and stiffness that occurs in about two-thirds of people with cerebral palsy and in many who suffer severe head injuries. The medical definition of dystonia is a velocity-dependent, increased resistance to passive muscle stretch. In other words, when a muscle affected by spasticity is stretched by someone else, it is harder to move the muscle than normal, and the faster one pushes, the harder the muscle is to move.
Retardation
Delay or halt of any process such as mental or physical development.
Death
1. The end of life. The cessation of life. (These common definitions of death ultimately depend upon the definition of life, upon which there is no consensus.) 2. The permanent cessation of all vital bodily functions. (This definition depends upon the definition of "vital bodily functions.") See: Vital bodily functions. 3. The common law standard for determining death is the cessation of all vital functions, traditionally demonstrated by "an absence of spontaneous respiratory and cardiac functions." 4. The uniform determination of death.
Ataxia
Ataxia is unsteady and clumsy motion of the limbs or trunk due to a failure of the fine coordination of muscle movements. The cerebellum is the center of the fine coordination of muscle movements, while the information emerging from it is carried to the muscles by the spinal cord and peripheral nerves, respectively. Therefore a disorder in either the spinal cord or in the peripheral nerves can cause ataxia.
Abnormal
Not normal. Deviating from the usual structure, position, condition, or behavior. In referring to a growth, abnormal may mean that it is cancerous or premalignant (likely to become cancer).
Protein
Any of a group of complex organic compounds which contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur, the characteristic element being nitrogen. Proteins, the principal constituents of the protoplasm of all cells, are of high molecular weight and consist essentially of combinations of a-amino acids in peptide linkages. Twenty different amino acids are commonly found in proteins, and each protein has a unique genetically defined amino acid sequence which determines its specific shape and function. Their roles include enzymatic catalysis, transport and storage, coordinated motion, nerve impulse generation and many others.
GFAP
Glial fibrillary acidic protein. The degenerative brain condition called Alexander disease is caused by mutation in GFAP (glial fibrillary acidic protein). The GFAP gene provides instructions for making GFAP protein, a member of the intermediate filament family that provides support and strength to cells. Several molecules of GFAP protein bind together to form the main intermediate filament found in specialized brain cells called astrocytes. Astrocytes are star-shaped cells that support the functions of nerve cells in the brain and spinal cord (central nervous system). If the central nervous system is injured through trauma or disease, astrocytes react by rapidly producing more GFAP.
Gene
1. A unit of DNA that carries information for the biosynthesis of a specific product in the cell. 2. Ultimate unit by which inheritable characteristics are transmitted to succeeding generations in all living organisms. Genes are contained by, and arranged along the length of, the chromosome. The gene is composed of deoxyribonucleic acid (DNA). Each chromosome of each species has a definite number and arrangement of genes, which govern both the structure and metabolic functions of the cells and thus of the entire organism.
Genetic
Hereditary. Having to do with the genes.
Cell
Fundamental structural unit of all life. The cell consists primarily of an outer plasma membrane, which separates it from the environment; the genetic material (DNA), which encodes heritable information for the maintainance of life; and the cytoplasm, a heterogeneous assemblage of ions, molecules, and fluid.
CNS
see Central Nervous System.
Pathologist
A physician trained in the nature, cause, process and effects of disease; examines samples of tissue removed during surgery to determine an exact diagnosis.
SIMILAR TERMS--------------------------------------
Alexia
Loss of a previously intact ability to grasp the meaning of written or printed words and sentences.
Alexian Brothers Medical Center
Alexian Brothers Medical Center is a hospital in Elk Grove Village, Illinois (USA).
Alexithymia
A disturbance in affective and cognitive function that can be present in an assortment of diagnostic entities. Is common in psychosomatic disorders, addictive disorders, and posttraumatic stress disorder. The chief manifestations are difficulty in describing or recognizing one's own emotions, a limited fantasy life, and general constriction in affective life.
PREVIOUS AND NEXT TERMS--------------------------------------
Aldrin
See: Aldrin and dieldrin.
Aldrin and dieldrin
The common names of two structurally similar compounds that were once used as insecticides. They are chemicals that are made in the laboratory and do not occur naturally in the environment.
Aleut health
See: Artic health.
Aleve
See: Naproxen.
Alexander disease
Algia
Word ending indicating pain, as in arthralgia (joint pain), cephalgia (headache), fibromyalgia, mastalgia (breast pain), myalgia (muscle pain), and neuralgia (nerve pain). Derived from the Greek algos meaning pain.
Alice Stewart
See: Stewart, Alice.
Alkaline phosphatase
An enzyme made in the liver, bone, and the placenta and normally present in high concentrations in growing bone and in bile. Alkaline phosphatase is released into the blood during injury and during such normal activities as bone growth and pregnancy. It is measured in a routine blood test. Abnormally high blood levels of alkaline phosphatase may indicate disease in bone or liver, bile duct obstruction, or certain malignancies. The enzyme is often elevated in the leukemic cells in chronic myelogenous leukemia. Abnormally low levels of alkaline phosphatase is a genetic condition called hypophosphatasia which results in bone deformities. The enzyme is termed alkaline phosphatase because it works under alkaline (non-acidic) conditions, as opposed to acid phosphatase.
Alkaloid
A member of a large group of chemicals that are made by plants and have nitrogen in them. Many alkaloids possess potent pharmacologic effects. The alkaloids include cocaine, nicotine, strychnine, piperine, caffeine, morphine, pilocarpine, atropine, methamphetamine, mescaline, ephedrine, and tryptamine.
Alkaloid, vinca
See: Vinca alkaloid.
We thank you for using the Medical Glossary to search for Alexander disease. If you have a better definition for Alexander disease than the one presented here, please let us know by making use of the suggest a term option. This definition of Alexander disease may be disputed by other professionals. Our attempt is to provide easy definitions on Alexander disease and any other medical topic for the public at large.
This dictionary contains 19186 terms.
|
|