The term ‘stem cell’ was first coined by the Russian histologist Alexander Maksimov at the 1908 Congress of Hematologic Society in Berlin. Stem cells are a group of undifferentiated cells that can differentiate into a variety of specialized cells. They can, for example, take the form of cells that are required to build various body parts like heart muscles, brain tissue, and liver tissue.
Embryonic Stem Cells:
The stem cells obtained from the inner cell mass of a blastocyst, an early stage embryo, are called embryonic stem cells. Embryonic stem cells are pluripotent; that is, they can transform themselves into almost any specialized cell in the body. This makes embryonic stem cells interesting from the point of research. They could be induced to develop in a specified way and be used in medical therapies to repair or replace cells and tissue damaged by degenerative diseases.
Dr. James Thomson (20 December 1958), a renowned developmental biologist from the University of Wisconsin, has done pioneering work in stem cell research. In 1998, Dr. Thomson and his research team were the first to isolate and grow human embryonic stem cells in the laboratory.
Dr. Thomson, who grew up in Oak Park in Chicago, has a Bachelor of Science Degree in Biophysics (1981) from the University of Illinois and Doctorates in Veterinary Medicine (1985) and Molecular Biology (1988) from the University of Pennsylvania. He received a Veterinary Pathology Certification in 1995.
He became interested in embryonic development while studying at the University of Illinois. It was at this time, in 1981, that the researchers Martin Evans and Matthew Kaufman and Gail R. Martin (working independently) were successful in extracting embryonic stem cells from mouse embryos. Taking note, Thomson began working on extracting embryonic stem cells from rhesus monkeys.
He continued this research after moving to the University of Wisconsin in 1991 and was successful, in 1995, in isolating and extracting rhesus monkey embryonic stem cells. Then, after consulting with bioethicists and using discarded embryonic tissue that would otherwise have been destroyed, he ventured into human stem cell research.
Around this time, in 1997, Dr. Ian Wilmut of Scotland announced the successful creation of Dolly the clone sheep. Dolly had been created by inserting the DNA of an udder cell into an egg that had previously had its DNA removed. The creation of Dolly proved that cell development is reversible.
This discovery really interested Thomson. After he and his team successfully isolated and grew human embryonic cells in 1998, Thomson began to explore possibilities of inducing normal body cells to revert into embryonic cells. Ten years later, he created induced pluripotent stem (iPS) cells from skin cells. In this procedure no fetal biological material is needed resolving much of the controversy about using embryonic stem cells.