Bietti crystalline dystrophy
Bietti crystalline dystrophy A genetic eye disease that leads to progressive night blindness and visual field constriction and is characterized by the formation of crystals in the cornea (the clear covering of the eye), yellow shiny deposits on the retina, and progressive atrophy of the retina and choroid (the back layers of the eye). Average age of onset is 29. Lipid inclusions are present not only in the cornea but also in blood lymphocytes, suggesting a systemic disorder of lipid metabolism. There is no known treatment. The disease is an autosomal recessive trait (the gene is on chromosome 4q35-qter) and is named for G. B. Bietti, an Italian ophthalmologist, who described it in 1937. Also called Bietti crystalline corneoretinal dystrophy.
Hereditary. Having to do with the genes.
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.
Legal blindness is defined as: 1) visual acuity of 20/200 (only being able to see the big E on the eye chart) or less in the best eye even with the eyes corrected by glasses or contact lenses; or, 2) The peripheral visual field is reduced to 20 degrees of visual angle or less. Twenty degrees of visual angle is about the size of a one foot ruler held at arms length.
The front part of the eye that acts as a window for the entrance of light rays. It is attached to the other outer coat of the eye, the sclera; the white part of the eye. The cornea provides a significant amount of focusing power for the eye (the rest is provided by the lens). Because it has many nerve fibers, an injury or foreign body causes significant pain and discomfort.
A membrane lining the inside of the back of the eye that contains light-sensitive nerve cells that convert focused light into nerve impulses, making vision possible.
A defect or failure of cell nutrition manifested as decrease in size or healthiness of an organ or tissue.
This is the vascular coat between the sclera and the retina, which furnishes blood and nutrition to the outer layer of the retina.
A fatty substance in the blood.
The life-maintaining fluid which is made up of plasma, red blood cells (erythrocytes), white blood cells (leukocytes), and platelets; blood circulates through the body's heart, arteries, veins, and capillaries; it carries away waste matter and carbon dioxide, and brings nourishment, electrolytes, hormones, vitamins, antibodies, heat, and oxygen to the tissues.
Disease or symptoms that affect many different parts of the body.
The chemical activity that occurs in cells, releasing energy from nutrients, or using energy to create other substances, such as proteins.
"Pertaining to a chromosome that is not a sex chromosome; relating to any one of the chromosomes save the sex chromosomes. People normally have 22 pairs of autosomes (44 autosomes) in each cell together with two sex chromosomes (X and Y in the male and XX in the female). "
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.
A structural unit within a eukaryotic nucleus that carries genes. A chromosome consists of a long, continuous strand of DNA and associated proteins.
A physician (MD) who specializes in the diagnosis and treatment of eye problems and diseases. The ophthalmologist works with the use of glasses, contact lenses, eye medication and surgery.
Partial atrophy of tissue or an organ as a result of imperfect cell nutrition.
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In medicine, bicarbonate usually refers to bicarbonate of soda (sodium bicarbonate, baking soda) white powder that is common ingredient in antacids. Also, the bicarbonate level is an indirect measure of the acidity of the blood that is determined when electrolytes are tested. The normal serum range for bicarbonate is 22-30 mmol/L.
Having two horns or horn-shaped branches. The uterus (normally unicornuate) can sometimes be bicornuate (with two branches, eg, one at about 10:30 and the other at about 1:30).
Bicuspid aortic valve
Whereas the normal aortic valve in the heart has three flaps (cusps) that open and close, a bicuspid valve has only two. There may be no symptoms in childhood, but in time the valve may become stenotic (narrowed), making it harder for blood to pass through it, or the valve may start to let blood leak backwards through the valve (regurgitate). Treatment depends on how the valve is working.
A well-known but often neglected device designed to protect the head of a bicyclist.
Bid (on prescription)
"Seen on a prescription, bid means twice (two times) a day. It is an abbreviation for ""bis in die"" which in Latin means twice a day. The abbreviation bid is sometimes written without a period either in lower-case letters as ""bid"" or in capital letters as ""BID"" or with periods as ""b.i.d."" However it is written, it is one of a number of hallowed abbreviations of Latin terms that have been traditionally used in prescriptions to specify the frequency with which medicines should be taken. "
Bietti crystalline dystrophy
Cleft (split) in two. See, for example, bifid uvula.
The uvula, the little V-shaped fleshy mass hanging from the back of the soft palate, is cleft or split. Cleft uvula is a common minor anomaly occurring in about 1% of whites and 10% of Native Americans. Persons with a cleft uvula should not have their adenoids removed because, without the adenoids, they cannot achieve proper closure between the soft palate and pharynx while speaking and develop hypernasal speech.
Big bone disease
See: Kashin-Beck disease.
Big toe sign
An important neurologic examination based upon what the big toe (and other toes) do when the sole of the foot is stimulated. If the big toe goes up, that may mean trouble.
Body integrity identity disorder.
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