girlscout's Blog

     EMBRYONIC STEM CELLS - The most flexible type of stem cell is the embryonic stem cell. It comes from the cells found in the 5-6 day old embryo, called the blastocyst. Embryonic cells are  made from the left-over blastocysts that have developed from fertilized eggs produced by reproduction technologies such as in vitro fertilization. These left-over blastocysts are either donated to another couple or discarded. Once embyonic stem cells have been established in culture, large numbers of cells can be grown for a long time. The remarkable feature of these cells is that they can generate all types of adult cell types. They can be turned into brain cells, heart cells, blood vessels, skin, etc.

     ADULT STEM CELLS - Adult stem cells are cells that come from different parts of the body. They exist in several different tissues including bone marrow, blood and brain. Although a wealth of information has been collected, scientists till have much to learn.

     HEMATOPOIETIC STEM CELLS - Blood forming stem cells are adult blood cells found mainly in the bone marrow. Hematopoietic blood cells are easy to obtain and have been studied for many years. They were the first stem cells to be used successfully in blood disorder therapies. More recently, their use in treatment of breast cancer and coronary artery diseases is also being explored.

     MESENCHYMAL STEM CELLS -  These are another type jof adult stem cells. They are also found in the bone marrow. These cells can be grown in a Lab into fat cells, cartilage, bone, tendon and ligaments and even nerve cells. Unlike other adult stem cells, mesenchymal stem cells can be obtained in quantities appropriate for clinical applications. These cells can be taken from a patients bone marrow, expanded in culture, and given back to the patient.

     UBILICAL CORD BLOOD STEM CELLS -  Obtained from the umbilical cord immediately after birth. These cells are usually referred to as neo-natal and are less mature than stem cells found in adults. The advantage of umbilical cord cells is that it is easily obtained and abundant; thousands of babies are born every day, and until recently, umbilical cord blood was discarded after birth. Now these cells can be collected and stored. These cord cells  are a source for the treatment of leukemia and other blood disorders.

     SELF-RENEWAL AND STEM CELL EXPANSION FOR THERAPY - A stem cell is a cell that can renew itself indefinitely. To accomplish this task the stem has to divide continuously. One of the 2 cells retains the stem cell characteristics, while the other has a limited number of future divisions and will produce more organ-specific cells.

     This condensed information was taken from the "International Society for Stem Cell Research" website. Visit their website for more detailed information.