As their name suggests, embryonic stem cells come from living, human embryos. They are harvested from two sources.
• Embryos—Embryonic stem cells are obtained by harvesting living embryos which are generally 5-7 days old. The removal of embryonic stem cells invariably results in the destruction of the embryo.
• Fetuses—Another kind of stem cell called an embryonic germ cell can be obtained from either miscarriages or aborted fetuses.
Adult Stem Cells
The primary role of adult stem cells in humans is to maintain and repair the tissue in which they are found. While we call them adult stem cells, they are more accurately called somatic (from the Greek word soma = body) stem cells, because they come from not only adults, but other sources.
Adult type stem cells come from:
• Umbilical Cords, Placentas and Amniotic Fluid—Adult type stem cells can be derived from various pregnancy-related tissues.
• Adult Tissues—In adults, stem cells are present within various tissues and organ systems. These include the bone marrow, liver, epidermis, retina, skeletal muscle, intestine, brain, dental pulp, and elsewhere. Even fat obtained from liposuction has been shown to contain significant numbers of adult type stem cells.
• Cadavers—Neural stem cells have been removed from specific areas in post-mortem human brains as late as 20 hours following death.
Stem Cells from Adult Tissue or Umbilical Cord Blood.
Stem cells obtained from adult organisms are also the focus of research. There have been a number of recent publications on adult stem cells from a variety of different sources, such as bone marrow and the umbilical cord following birth.
Stem Cell
Stem cells are seen by many researchers as having virtually unlimited application in the treatment and cure of many human diseases and disorders including Alzheimer's, diabetes, cancer, strokes, etc. Stem cells come in two general types:
-Embryonic stem cells are a primitive type of cell that can be coaxed into developing into all of the 220 types of cells found in the human body (e.g. blood cells, heart cells, brain cells, nerve cells, etc). They are derived from human embryos in a process that causes the death of the embryos.
-Adult stem cells bear some similarities to embryonic stem cells. Research using adult cells has a two decade head start on embryonic stem cells. Thus, potential treatments have already advanced to human trial stage. Unfortunately, adult cells are limited in flexibility.
Adult Stem Cells
The primary role of adult stem cells in humans is to maintain and repair the tissue in which they are found. While we call them adult stem cells, they are more accurately called somatic (from the Greek word soma = body) stem cells, because they come from not only adults, but other sources.
Adult type stem cells come from:
• Umbilical Cords, Placentas and Amniotic Fluid—Adult type stem cells can be derived from various pregnancy-related tissues.
• Adult Tissues—In adults, stem cells are present within various tissues and organ systems. These include the bone marrow, liver, epidermis, retina, skeletal muscle, intestine, brain, dental pulp, and elsewhere. Even fat obtained from liposuction has been shown to contain significant numbers of adult type stem cells.
• Cadavers—Neural stem cells have been removed from specific areas in post-mortem human brains as late as 20 hours following death.
Stem Cells from Adult Tissue or Umbilical Cord Blood.
Stem cells obtained from adult organisms are also the focus of research. There have been a number of recent publications on adult stem cells from a variety of different sources, such as bone marrow and the umbilical cord following birth.
"The Center for International Blood and Marrow Transplant Research (CIBMTR) estimates that approximately 4,700 stem cell transplants of various types were performed in patients with myeloma in North America in 2003 (CIBMTR, 2005)."
