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Canavan Disease
Canavan disease, or Canavan-Van Bogaert-Bertrand disease, is a rare and fatal autosomal recessive degenerative disease that causes progressive damage to nerve cells and loss of white matter in the brain. It is one of the most common degenerative cerebral diseases of infancy. It is caused by a deficiency of the enzyme aminoacylase 2, and is one of a group of genetic diseases referred to as leukodystrophies. It is characterized by degeneration of myelin in the phospholipid layer insulating the axon of a neuron and is associated with a gene located on human chromosome 17. Symptoms and signs Symptoms of the most common (and most serious) form of Canavan disease typically appear in early infancy usually between the first three to six months of age. Canavan disease then progresses rapidly from that stage, with typical cases involving intellectual disability, loss of previously acquired motor skills, feeding difficulties, abnormal muscle tone (i.e., initial floppiness - hypotonia - that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autosome
An autosome is any chromosome that is not a sex chromosome. The members of an autosome pair in a diploid cell have the same morphology, unlike those in allosomal (sex chromosome) pairs, which may have different structures. The DNA in autosomes is collectively known as atDNA or auDNA. For example, humans have a diploid genome that usually contains 22 pairs of autosomes and one allosome pair (46 chromosomes total). The autosome pairs are labeled with numbers (1–22 in humans) roughly in order of their sizes in base pairs, while allosomes are labelled with their letters. By contrast, the allosome pair consists of two X chromosomes in females or one X and one Y chromosome in males. Unusual combinations of XYY, XXY, XXX, XXXX, XXXXX or XXYY, among other Salome combinations, are known to occur and usually cause developmental abnormalities. Autosomes still contain sexual determination genes even though they are not sex chromosomes. For example, the SRY gene on the Y chromosom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paralysis
Paralysis (also known as plegia) is a loss of motor function in one or more muscles. Paralysis can also be accompanied by a loss of feeling (sensory loss) in the affected area if there is sensory damage. In the United States, roughly 1 in 50 people have been diagnosed with some form of permanent or transient paralysis. The word "paralysis" derives from the Greek παράλυσις, meaning "disabling of the nerves" from παρά (''para'') meaning "beside, by" and λύσις (''lysis'') meaning "making loose". A paralysis accompanied by involuntary tremors is usually called "palsy". Causes Paralysis is most often caused by damage in the nervous system, especially the spinal cord. Other major causes are stroke, trauma with nerve injury, poliomyelitis, cerebral palsy, peripheral neuropathy, Parkinson's disease, ALS, botulism, spina bifida, multiple sclerosis, and Guillain–Barré syndrome. Temporary paralysis occurs during REM sleep, and dysregulation of this system can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithium Citrate
Lithium citrate (Li3C6H5O7) is a chemical compound of lithium and citrate that is used as a mood stabilizer in psychiatric treatment of manic states and bipolar disorder. There is extensive pharmacology of lithium, the active component of this salt. Lithia water contains various lithium salts, including the citrate. History An early version of Coca-Cola available in pharmacies' soda fountains called Lithia Coke was a mixture of Coca-Cola syrup and lithia water. The soft drink 7Up was originally named "Bib-Label Lithiated Lemon-Lime Soda" when it was formulated in 1929 because it contained lithium citrate. The beverage was a patent medicine marketed as a cure for hangover. Lithium citrate was removed from 7Up in 1948 after it was banned by the Food and Drug Administration. Lithium Citrate is used as a mood stabilizer and is used to treat mania, hypomania, depression and bipolar disorder Bipolar disorder, previously known as manic depression, is a mental disorder c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Insulation
An electrical insulator is a material in which electric current does not flow freely. The atoms of the insulator have tightly bound electrons which cannot readily move. Other materials—semiconductors and conductors—conduct electric current more easily. The property that distinguishes an insulator is its resistivity; insulators have higher resistivity than semiconductors or conductors. The most common examples are non-metals. A perfect insulator does not exist because even insulators contain small numbers of mobile charges (charge carriers) which can carry current. In addition, all insulators become electrically conductive when a sufficiently large voltage is applied that the electric field tears electrons away from the atoms. This is known as the breakdown voltage of an insulator. Some materials such as glass, paper and PTFE, which have high resistivity, are very good electrical insulators. A much larger class of materials, even though they may have lower bulk resistivit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nerve
A nerve is an enclosed, cable-like bundle of nerve fibers (called axons) in the peripheral nervous system. A nerve transmits electrical impulses. It is the basic unit of the peripheral nervous system. A nerve provides a common pathway for the electrochemical nerve impulses called action potentials that are transmitted along each of the axons to peripheral organs or, in the case of sensory nerves, from the periphery back to the central nervous system. Each axon, within the nerve, is an extension of an individual neuron, along with other supportive cells such as some Schwann cells that coat the axons in myelin. Within a nerve, each axon is surrounded by a layer of connective tissue called the endoneurium. The axons are bundled together into groups called fascicles, and each fascicle is wrapped in a layer of connective tissue called the perineurium. Finally, the entire nerve is wrapped in a layer of connective tissue called the epineurium. Nerve cells (often called neurons) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nerve Fiber
An axon (from Greek ἄξων ''áxōn'', axis), or nerve fiber (or nerve fibre: see spelling differences), is a long, slender projection of a nerve cell, or neuron, in vertebrates, that typically conducts electrical impulses known as action potentials away from the nerve cell body. The function of the axon is to transmit information to different neurons, muscles, and glands. In certain sensory neurons ( pseudounipolar neurons), such as those for touch and warmth, the axons are called afferent nerve fibers and the electrical impulse travels along these from the periphery to the cell body and from the cell body to the spinal cord along another branch of the same axon. Axon dysfunction can be the cause of many inherited and acquired neurological disorders that affect both the peripheral and central neurons. Nerve fibers are classed into three types group A nerve fibers, group B nerve fibers, and group C nerve fibers. Groups A and B are myelinated, and group C are unmyelinated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N-Acetylaspartate
''N''-Acetylaspartic acid, or ''N''-acetylaspartate (NAA), is a derivative of aspartic acid with a formula of C6H9NO5 and a molecular weight of 175.139. NAA is the second-most-concentrated molecule in the brain after the amino acid glutamate. It is detected in the adult brain in neurons, oligodendrocytes and myelin and is synthesized in the mitochondria from the amino acid aspartic acid and acetyl-coenzyme A. Function The various functions served by NAA are under investigation, but the primary proposed functions include: * Neuronal osmolyte that is involved in fluid balance in the brain * Source of acetate for lipid and myelin synthesis in oligodendrocytes, the glial cells that myelinate neuronal axons * Precursor for the synthesis of the neuronal dipeptide N-Acetylaspartylglutamate * Contributor to energy production from the amino acid glutamate in neuronal mitochondria In the brain, NAA was thought to be present predominantly in neuronal cell bodies, where it acts as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspartoacylase
Aspartoacylase is a hydrolytic enzyme (, also called ''aminoacylase II'', ''ASPA'' and other names) that in humans is encoded by the ''ASPA'' gene. ASPA catalyzes the deacylation of ''N''-acetyl-l-aspartate (''N-acetylaspartate)'' into aspartate and acetate. It is a zinc-dependent hydrolase that promotes the deprotonation of water to use as a nucleophile in a mechanism analogous to many other zinc-dependent hydrolases. It is most commonly found in the brain, where it controls the levels of ''N''-acetyl-l-aspartate. Mutations that result in loss of aspartoacylase activity are associated with Canavan disease, a rare autosomal recessive neurodegenerative disease. Structure Aspartoacylase is a dimer of two identical monomers of 313 amino acids and uses a zinc cofactor in each. There are two distinct domains in each monomer: the N-terminal domain from residues 1-212 and the C-terminal domain from residues 213–313. The N-terminal domain of aspartoacylase is similar to that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the react ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ASPA (gene)
Aspartoacylase is a hydrolytic enzyme (, also called ''aminoacylase II'', ''ASPA'' and other names) that in humans is encoded by the ''ASPA'' gene. ASPA catalyzes the deacylation of ''N''-acetyl-l-aspartate (''N-acetylaspartate)'' into aspartate and acetate. It is a zinc-dependent hydrolase that promotes the deprotonation of water to use as a nucleophile in a mechanism analogous to many other zinc-dependent hydrolases. It is most commonly found in the brain, where it controls the levels of ''N''-acetyl-l-aspartate. Mutations that result in loss of aspartoacylase activity are associated with Canavan disease, a rare autosomal recessive neurodegenerative disease. Structure Aspartoacylase is a dimer of two identical monomers of 313 amino acids and uses a zinc cofactor in each. There are two distinct domains in each monomer: the N-terminal domain from residues 1-212 and the C-terminal domain from residues 213–313. The N-terminal domain of aspartoacylase is similar to that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Testing
Genetic testing, also known as DNA testing, is used to identify changes in DNA sequence or chromosome structure. Genetic testing can also include measuring the results of genetic changes, such as RNA analysis as an output of gene expression, or through biochemical analysis to measure specific protein output. In a medical setting, genetic testing can be used to diagnose or rule out suspected genetic disorders, predict risks for specific conditions, or gain information that can be used to customize medical treatments based on an individual's genetic makeup. Genetic testing can also be used to determine biological relatives, such as a child's biological parentage (genetic mother and father) through DNA paternity testing, or be used to broadly predict an individual's ancestry. Genetic testing of plants and animals can be used for similar reasons as in humans (e.g. to assess relatedness/ancestry or predict/diagnose genetic disorders), to gain information used for selective breedin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Counseling
Genetic counseling is the process of investigating individuals and families affected by or at risk of genetic disorders to help them understand and adapt to the medical, psychological and familial implications of genetic contributions to disease; this field is considered necessary for the implementation of genomic medicine. The process integrates: * Interpretation of family and medical histories to assess the chance of disease occurrence or recurrence * Education about inheritance, testing, management, prevention, resources * Counseling to promote informed choices, adaptation to the risk or condition and support in reaching out to relatives that are also at risk History The practice of advising people about inherited traits began around the turn of the 20th century, shortly after William Bateson suggested that the new medical and biological study of heredity be called "genetics". Heredity became intertwined with social reforms when the field of modern eugenics took form. Althou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
