Strep throat is a contagious disease caused by infection with streptococcal bacteria, which causes inflammation and swelling of the mucous membranes lining the back of the throat and the tonsils.trep throat is a contagious disease caused by infection with streptococcal bacteria, which causes inflammation and swelling of the mucous membranes lining the back of the throat and the tonsils.
Once an egg cell is fertilized by a sperm, it will divide and become an embryo. In the embryo, there are stem cells that are capable of becoming all of the various cell types of the human body. For research, scientists get embryos in two ways. Many couples conceive by the process of in vitro fertilization. In this process, a couple's sperm and eggs are fertilized in a culture dish.
Stem Cell Therapy. Much of the attention and all of the controversy surrounding stem cell therapy has focused on embryonic stem cells -- cells harvested four to five days after an embryo is fertilized. Adult stem cells exist to replace damaged or aging cells, and they are found in tissue throughout the body of adults and in the blood and bone marrow, where cells are much easier to harvest. Stem cell therapy has been used for many decades to treat leukemia and other cancers, but the treatment-related death rate is high due to the aggressive chemotherapy and/or radiation used to dramatically suppress the immune system and kill cancer cells.