- undifferentiated) cells that are characteristically of the same family type (lineage). They retain the ability to divide throughout life and give rise to cells that can become highly specialized and take the place of cells that die or are lost. Stem cells contribute to the body's ability to renew and repair its tissues. Unlike mature cells, which are permanently committed to their fate, stem cells can both renew themselves as well as create new cells of whatever tissue they belong to (and other tissues).
Bone marrow stem cells, for example, are the most primitive cells in the marrow. From them all the various types of blood cells are descended. Bone marrow stem-cell transfusions (or transplants) were originally given to replace various types of blood cells. Stem cells from bone marrow can also, quite remarkably, give rise to non-marrow cells. In a 1999 report in the journal Nature, scientists from Boston led by Dr. Louis M. Kunkel reported that they gave bone marrow transplants from normal mice to dystrophic mice. Some 12 weeks later about 10% of the muscle fibers in the diseased animals were making the correct form of dystrophin, the protein that is defective in Duchenne muscular dystrophy. This work suggests that bone marrow stem cells may offer new ways of treating muscular dystrophy (and other non-blood diseases).
* * *stem cell 'stem- n an unspecialized cell that gives rise to differentiated cells <hematopoietic stem cells in bone marrow>
* * *an undifferentiated cell that is able to renew itself and produce all the specialized cells within an organ. Stem cells occur in many tissues and organs, including the bone marrow (see haemopoietic stem cell), muscle, liver, pancreas, etc. Embryonic stem cells, in the blastocyst of the embryo, are capable of producing all the different cell types required by the developing embryo (i.e. they are pluripotent). See also umbilical cord blood banked stem cells.
Medical dictionary. 2011.
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stem cell — n technical a special type of cell in the body that can divide in order to form other types of cells that have particular qualities or purposes … Dictionary of contemporary English
stem cell — stem′ cell n. cbl a cell that upon division replaces its own numbers and also gives rise to cells that differentiate further into one or more specialized types • Etymology: 1880–85 … From formal English to slang
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stem cell — noun an undifferentiated cell whose daughter cells may differentiate into other cell types (such as blood cells) • Hypernyms: ↑somatic cell, ↑vegetative cell • Hyponyms: ↑hematopoeitic stem cell * * * noun : an unspecialized and usually embryonic … Useful english dictionary
stem cell — an undifferentiated cell that is able to renew itself and produce all the specialized cells within an organ. Stem cells occur in many tissues and organs, including the bone marrow (see haemopoietic stem cell), muscle, liver, pancreas, etc.… … The new mediacal dictionary