Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «L»:
Levo-alpha acetyl methadol
Levo-alpha acetyl methadol: Abbreviated LAAM. An alternative to methadone. See: LAAM....
Levocardia: Reversal of all of the abdominal and
thoracic organs (situs inversus) except the heart, which is still in
its usual location on the left. Levocardia virtually
always rerflects the presence of congenital heart disease (malformation of
the heart or great vessels). See also: Dextrocardia....
Levonorgestrel: A progestin. Named levonorgestrel because it is the levorotatory form of norgestrel. Used in combination with an estrogen as an oral contraceptive. Used alone for emergency contraceptive (in Plan B) and the treatment of menstrual disorders or endometriosis....
Levothyroxine: A synthetic thyroid hormone
used as a thyroid hormone replacement drug (brand names
include Eltroxin, Levothroid, Levoxine, Levoxyl, Synthroid)
used to treat an underactive thyroid gland
(hypothyroidism). Because not all brands of levothyroxine
sodium are equivalent, it is import...
Lewis Thomas: See: Thomas, Lewis....
Lewis, Edward B
Lewis, Edward B: (1918-2004) American geneticist and Nobel Laureate who showed how genes control embryonic development. In 1957 Lewis discovered that genes were arranged on chromosomes in the same order as they were activated along the body axis during development, a concept known as the colinearit...
LFCN: Lateral femoral cutaneous nerve. See also: Meralgia paresthetica....
LGV: Lymphogranuloma venereum....
Lhermitte sign: Sudden transient electric-like shocks extending down the spine triggered by flexing the head forward. Due to a disorder such as compression of the cervical spine (the portion of the spinal cord within the neck).
One patient who experienced Lhermitte sign wrote that: "Looking down to ...
LHRH agonist: A compound that is similar to LHRH (luteinizing hormone-releasing hormone) in structure and is able to act like it. Luteinizing hormone-releasing hormone is a naturally occurring hormone that controls sex hormones in both men and women. Thus, an LHRH agonist serves in a manner similar ...
Li-Fraumeni syndrome (LFS)
Li-Fraumeni syndrome (LFS): This is an extraordinary
cancer family syndrome. People with LFS have a tendency to develop a
great diversity of tumors.
LFS was first discovered in 1969. By reviewing the medical
records and death certificates of children with a relatively rare
tumor, a soft tissue s...
Libido: 1. Sexual drive. 2. In psychoanalysis, the psychic energy from all instinctive biological drives.
Libido in Latin means "desire, longing, fancy, lust, or rut." Although the adjective libidinous, meaning lustful, has been used in English for 500 or so years, libido only entered the language ...
Library: In genetics, a library is an unordered
collection of clones (i.e., cloned DNA from a particular organism),
whose relationship to
each other can be established by physical mapping. For example, you
can have an E. coli
library or a human DNA library. Among the types of libraries, there
Library of Medicine, National (NLM)
Library of Medicine, National (NLM): The world's largest medical library, the U.S. National Library of Medicine (NLM) is part of the National Institutes of Health (NIH). The NLM has as its mission to collect, organize, and make available biomedical science information to investigators, educators, a...
Library, arrayed: In genetics, arrayed libraries of DNA
clones are used for many purposes, including screening for a specific gene or genomic
region of interest as well as for physical mapping. An arrayed library consists of (in
technical terms) individual primary recombinant clones (which are hoste...