- Health & Wellness
- Dr. Frischer
- 1474 views
Today's subject is key to the future of medicine. Stem cell research is being conducted worldwide, and is frequently in the headlines. Earlier this month, in fact, the Nobel Prize in Medicine was awarded to researchers in the US and Japan for their work to reprogram cells to become embryonic-like stem cells. The potential for drug discovery, personalized medicine, fertility, and tissue and organ regeneration is enormous.
Work with stem cells, however, is still in its infancy, and there are no standards for use. There are also, to my knowledge, no insurance companies yet on board to pay for treatments, but that is likely just a matter of time. A close friend of mine just left for Germany to receive stem cell therapy for his back...instead of surgery. This is where Kobe Bryant went for stem cell therapy on his arthritic knee, and other athletes are following suit. Is this merely hype?
Stem cells are the body's raw materials. These are cells from which all other specialized cells are generated, and are unique in that no other cells in the body have the natural ability to grow new cell types. A stem cell line is a group of cells descended from a single original stem cell. They keep growing, but don't differentiate into specialized cells. Ideally, these cells remain free of genetic defects and continue to create more stem cells. Cells can be taken from a stem cell line and frozen for later use, or shared with other researchers. The key to their clinical use is when these undifferentiated stem cells are manipulated to grow specific tissue or organs.
The earliest clinical use of stem cells began in the 1960s, when stem cells harvested from donor bone marrow were used for bone marrow transplants. This practice has now become routine for a variety of diseases, leukemia in particular. They are also now being used to treat a number of degenerative diseases, spinal cord injuries, heart failure, cancer, and other blood-related diseases, and some of the newest applications include worn-out joints and skin (burn victims can have their own stem cells harvested and sprayed on their skin for rapid healing). Stem cell therapy, also called regenerative medicine, is the replacement of diseased, dysfunctional or injured cells with stem cells. Potentially, these cells can be used to grow actual organs for transplant.
To be useful in clinical practice, we must be certain that stem cells will differentiate into the specific cell type desired. We don't want to inject a stem cell into the heart hoping that it will proliferate and replace defective heart muscle, and then have it actually became a bone cell. Other challenges are that stem cells may grow irregularly, travel to unintended parts of the body, or trigger an immune response in which the recipient's body attacks the stem cells as foreign.
Where do stem cells come from?
*Adult stem cells are found in small numbers in most adult tissue. They are also found in children, and in placentas and umbilical cords. They are also known as somatic ("of the body") stem cells.
*Embryonic stem cells come from four to five day old embryos. At this stage, an embryo, or blastocyst, is made up of only about 150 cells. These are pluripotent stem cells, meaning they can divide into more stem cells, or they can specialize and become any type of body cell. Because of this versatility, they have the highest potential for regenerating or repairing diseased tissue and organs.
*Pluripotent stem cells can also come from adult cells that are altered to have properties of embryonic stem cells. It is this work that just earned the researchers mentioned above the Nobel Prize in Medicine. This could be a key to avoiding the controversy that comes with the use of embryonic stem cells. What we don't know is the effects of this process over time. Will they be as versatile, durable and safe to use as embryonic stem cells?
*Finally, stem cells can come from small amounts of amniotic fluid. Amniotic fluid fills the sac that surrounds and protects a developing fetus in the uterus.
Much of the controversy around stem cells arises because embryonic stem cells have been extracted from early-stage embryos. Embryos currently being used in research originally came from eggs that were fertilized at in-vitro fertilization clinics, but never implanted. These unused embryos were frozen and later voluntarily donated for research purposes. Those who oppose federal funding for stem cell research often do so because they hold the belief that any embryo represents a potential human life.
And what about cloning? Cloning uses stem cells to create a genetically identical copy. Many of us recall Dolly the sheep; in 1996 the first successfully cloned mammal. Unfortunately, although most sheep of her breed live 11-12 years, Dolly died at the age of seven from progressive lung disease. She also suffered from advanced arthritis. Cloned mice tend to die young as well. As far as we know, a human being has not been successfully cloned, however it wouldn't surprise me if top-secret research were being conducted.
I highly recommend that you stay tuned and follow with great curiosity future stem cell news. These new discoveries will shape the future of our health care.
Dr. Alan Frischer is former chief of staff and former chief of medicine at Downey Regional Medical Center. Write to him in care of this newspaper at 8301 E. Florence Ave., Suite 100, Downey, CA 90240.
Published: October 25, 2012 - Volume 11 - Issue 28