Where are adult stem cells found ? scientists has done so many research in order to answer this question, They are thought to live in a specific area of each tissue (called a “stem cell niche”). Adult stem cells have been found by the scientists in the brain, teeth, heart, gut, liver blood vessels, skeletal muscle, skin, bone marrow, and other (although not all) organs and tissues, Stem cells may remain quiescent (non-dividing) for long periods of time until they are activated by a normal need for more cells to maintain tissues, or by disease or tissue injury. Adult stem cells can be isolated depending on the tissue from the body in different ways. Mesenchymal stem cells, which can make bone, cartilage, fat, fibrous connective tissue, and cells that support the formation of blood can be isolated from bone marrow. Blood stem cells, for example, can also be taken from a donor’s bone marrow, from blood in the umbilical cord when a baby is born, or from a person’s circulating blood. Isolating adult stem cells is just the first step. The cells then need to be grown to large enough numbers to be useful for treatment purposes.
Many pregnant women are elected to have amniotic fluid drawn to test for chromosome defects, the procedure known as amniocentesis. Amniotic fluid, which bathes the Fetus in the womb, contains fetal cells including mesenchymal stem cells, which are able to make a variety of tissues. This fluid is normally discarded after testing. These tissues would match the baby genetically, so there would be no rejection by the immune system or even allergic reaction cause of rejection, and could be implanted either in utero or after the baby is born. Adult stem cells made in Induced Pluripotent Stem Cells ways would potentially match the patient genetically, eliminating both the problem of tissue rejection and the need for toxic therapies to suppress the immune system. A number of research groups have reported that certain kinds of adult stem cells can transform, or differentiate, into apparently unrelated cell types (such as brain stem cells that differentiate into blood cells or blood forming cells that differentiate into cardiac muscle cells). This phenomenon, called transdifferentiation has been reported in some animals. However, it’s still far from clear how versatile adult stem cells really are, whether transdifferentiation can occur in human cells, or whether it could be made to happen reliably in the Lboratory.