Oprah had a show dedicated to stem cells. Her guests were Michael J. Fox, who suffers from Parkinson’s Disease and is an enthusiastic advocate for embryonic stem cell research, and Dr. Oz who seems to think that adult stem cells might be able to do all the heavy lifting for regenerative treatments. He actually brought a brain to the show and showed the midbrain to demonstrate the cells that die off during Parkinson’s disease.
Unfortunately, something Dr. Oz does not mention is that cells introduced into the brain tend to be shielded from the immune system and any embryonic stem cell derivatives that were introduced into the brains of patients with Parkinson’s disease are protected from the immune system by the blood-brain barrier. Thus, Dr. Oz’s concern about immunological rejection probably does not apply to the brain, unless the blood-brain barrier is damaged.