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Stem Cells

Feb. 1, 2009
What will they be when they grow out?
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What will they be when they grow out?

by Diane Brucato-Thomas, RDH, EF, BS, FAADH

“To be or not to be? That is the question…” was likely uttered on the stage at the Shakespeare Festival next door to where we sat on a blanket on the Lithia Park grass, in Ashland, Oregon. We were contemplating the backgammon board between us, as leaves sprinkled down, in the crisp autumn air. Apparently, the backgammon board was not all that Jack was contemplating. A similar question left his lips, “Diane, when does the will begin?”

“Uh, well ... uuhhhhh ...” Now, there was a question that I had not thought much about. Jack was good at snatching those kinds of questions out of thin air. Sometimes, I thought he used them as a means of distraction if I was winning, so I would make a dumb move. But then, his letters were the same way: “How many drops of water does it take to fill a swimming pool?” and he would go about figuring it out — step by brilliant step in the body of the letter.

I came back to the question at hand and darn near gave away the game. I never was good at multitasking. Jack looked at me. “Well? Does a plant have a will when it turns toward the light? Does a protozoa have a will? Does the will begin before or after the brain develops? Does a sperm cell have a will when it starts its journey with such seeming determination? Or does the will begin when the fertilized egg starts to divide? Or is it when the cells differentiate, determining their purpose within the organism? Exactly when does the will begin?”

We ended up going round and round on that one, on that breezy fall day in 1984.

Fifteen years before I met this brilliant man, who could conjure scientific facts and philosophical dilemmas on a whim, Jack was diagnosed with Parkinson's disease. He was far from being alone. Parkinson's is a very common neurodegenerative disorder, found to affect 2% of the population over age 65. Actor Michael J. Fox brought Parkinson's more into the limelight when he was diagnosed at a much younger age. It is caused by a progressive degeneration and loss of neurons in the brain that produce dopamine. The symptoms include tremors, abnormally decreased mobility (hypokinesia), and rigidity. I remember Jack holding my arm as his feet would shuffle to a slow start, just to walk from here to there.

Jack died in 1996.

How I would love to have the opportunity to have a deep discussion with Jack today! Parkinson's disease may be among the first diseases to be well-suited to treatment using stem cell transplantation. Methods to induce embryonic stem cells to differentiate into cells with many of the functions of specific dopamine-producing neuron cells have been successfully developed in several laboratories.

Jack would have been fascinated to learn that recently scientists directed mouse embryonic stem cells to differentiate into dopamine-producing neurons and then transplanted them into the brains of a rat model of Parkinson's disease. These stem cell derived neurons reinnervated the brains of the rat Parkinson model, released dopamine, and improved their motor function!

Scientists are now developing a number of strategies in the laboratory for producing dopamine-releasing neurons from human adult stem cells to be transplanted into humans with Parkinson's disease. If the generation of an unlimited supply of dopamine-producing neurons is successful, neurotransplantation may be widely available for Parkinson's patients in the future.

Parkinson's disease is just one of many previously incurable diseases and conditions that may find a cure in stem cell regenerative therapies. Muscular dystrophy, Alzheimer's disease, osteoporosis, diabetes, cardiovascular disease, renal failure, and spinal cord injuries are a few others. Virtually any disease that occurs as a result of damaged, failing or malfunctioning tissues may potentially be cured through regenerative therapies.

Stem cells from one part of the body will be expanded (grown out) and reimplanted to replace an entirely different type of tissue. This type of transplant will totally negate the need for antirejection drugs, since the implant is made of the patient's own body cells.

Most recently, the very first engineered whole organ transplant, using a windpipe made with the patient's own stem cells, was successfully completed by surgeons in Spain. The patient was a 30-year-old woman, whose airways were damaged by tuberculosis and who needed the transplant to save her lung.

The doctors removed a trachea and bronchus from a donor patient who recently died. Using strong chemicals and enzymes, all of the cells were dissolved from the donor trachea, leaving only a fibrous tissue scaffolding made of collagen protein. This structure was used as the framework to repopulate with the woman's own cells. The doctors used two types of the woman's own cells to populate the scaffold — cells lining her own windpipe, and very immature bone marrow cells (adult stem cells), which could be encouraged to form the kind of cells that normally surround the trachea.

The repopulated scaffold was rotated in a special bioreactor and after only four days of growth in the lab, the newly-coated donor trachea was ready for transplant. It looked and behaved identically as a normal human donor trachea would. This was cut to fit and replaced the woman's damaged windpipe. Four days after the transplant, the hybrid trachea was almost indistinguishable from the adjacent normal airway. Further, there was no sign of rejection four months later.

The idea of using stem cells from the person's own body to provide undifferentiated mesenchymal cells, not only circumvents the necessity for antirejection medication, it entirely avoids the controversy of using embryonic stem cells. Most exciting for us in the dental field is that undifferentiated mesenchymal cells originated from the cranial ectoneuromesioderm can be found in the pulp of teeth! These stem cells may be used to produce tissues found from the neck up, including nerves, bone, cartilage, and fat.

This discovery prompted Dr. Greg Chotkowski, an oral surgeon whose own son suffers from muscular dystrophy, to look at the plethora of extracted teeth being discarded daily in an entirely new light. Here was a noninvasive source of magical adult stem cells readily available for patients' future access. This realization led Dr. Chotkowski to create StemSave, a company that provides an opportunity for dentists and patients to recover and cryogenically preserve their own or their child's healthy stem cells for future regenerative purposes. This is an incredible gift of life to offer for your child's future health.

One of my favorite clients is a smart and beautiful 30-year-old mother from Brazil. She was showing me a picture of her darling 10-month-old son, when she cited her gratefulness that he was born in good health. She told me that, at the time when she gave birth, she had been reading about stem cell therapies and research being done, and asked the nurses at her hospital about banking the umbilical stem cells. Surprisingly, she was told that it was too difficult and, therefore, was not given the opportunity. Imagine, this woman was thrilled to hear from me that there would be another opportunity when her little boy began to lose his baby teeth.

Deciduous teeth that are just starting to loosen, particularly incisors or canines, with more than one-third of the root structure intact, are perfect candidates for viable pulpal stem cell recovery. The tooth must be free of infection, deep caries, and have an intact blood supply. Mesodens or supernumerary teeth are another ideal source. Extracted permanent teeth, such as wisdom teeth or bicuspids extracted for orthodontic purposes can also be a source for adult stem cells, as long as the teeth are free of infection or pathology, have a complete root, and intact blood supply.

If a client chooses to bank their dental stem cells, they can enroll online at www.stemsave.com. Their dentist will then receive a recovery and transport kit in time for the extraction appointment. When the tooth is removed from the oral cavity at 98.6 degrees, the dentist places the tooth or teeth into a vial included in the recovery kit. This is then placed into a thermos containing a patented phase change material that maintains the internal environment of the thermos at room temperature, inducing hypothermia. UPS is dispatched through StemSave for immediate pickup and delivery within 48 hours. This is critical to keep the pulp alive.

When StemSave receives the package, the teeth are removed and disinfected. Then they are cracked open, and the pulp is removed and tested for viability. The dental stem cells are then cryogenically preserved in liquid nitrogen utilizing DMSO as a cryoprotectant. DMSO prevents crystallization damage within the cells, so, even though frozen, the cells remain undamaged in suspended animation at a cryopreservation facility that has been in business for 25 years.

At this point in time, studies involving the applicability of adult stem cells derived from dental pulp has focused on proving the viability of these cells for regenerative applications. Less invasive than extracting stem cells from conventional sources, such as bone marrow and umbilical cords, dental pulp stem cell extraction is an attractive and less expensive alternative.

Jeremy Mao, DDS, PhD, a professor and director of the Tissue Engineering and Regenerative Medicine Laboratory and professor of dentistry at Columbia University, states that, although more clinical research and differentiation studies are needed involving dental stem cells, the future holds a great potential for the use of these cells. Clinical research of the potential for utilizing these cells in the treatment of diseases or conditions involving neural, bone, cartilage, or fat is just beginning.

Dr. Mao's latest announcement states in an abstract that he has turned dental stem cells into pancreatic beta islet cells that produce insulin. Considering the fact that the occurrence of diabetes in the United States is reaching epidemic proportions, this is most exciting!

Since the very beginning of the profession of dental hygiene, dental hygienists were known as specialists in prevention. In recent years, as periodontal diseases have become linked with systemic diseases, dental hygienists are being touted as not only saving teeth, but saving lives! Now, dental hygienists are in the unique position to not only save lives, but actually play a role in improving the quality of and extending lives.

Dental hygienists see almost every client that comes in the door. How many of these adults need an extraction?

How many college kids are having their wisdom teeth extracted? How many teens are getting orthodontic extractions? How many little tykes are anxiously awaiting the tooth fairy? How many new mothers like my client were denied an opportunity to bank their umbilical stem cells? Imagine the fact that encouraging the simple banking of those viable dental stem cells may save and extend their lives in the event of an unfortunate disease or condition occurring. Talk about making a difference!

Now that I've got your attention, stay tuned. The sequel to this article will go into more depth to help you understand the miraculous life-giving science of stem cells and regenerative medicine.

This brings me back to Jack. I found a couple of letters he wrote to my husband. In this one from 1988, Jack relates that his cousin once asked:

“You say, ‘And so you are 70 and have your own hell with that Parkinson's disease.' Has the happiness in your life been worth the suffering?”

Jack answered:

“My whole life, practically, has been a wonderful experience. Somehow I escaped the thistle and thorns. The accent on my existence has been exploring and knowing. I find the times we live in now most fascinating.

“I never planned on an immortal existence ... Man and other living things go through a cycle of birth, life, and death. I remember, as a youngster, asking the question: ‘What is the mechanism for gathering together the residue of ashes or bacterial decay and reconstituting it into a loving sentient being? A shriveled shell of 75 or an improved new young model?'”

In another letter from December 1981, Jack writes: “How often do you pause to marvel at the new things of recent years? ... sending a space craft to Jupiter and having thousands of pictures sent back, putting a man on the moon, releasing nuclear energy, the wonders of electronics ... Who needs (more) miracles? We've got all we need ... and real ones.”

These contemplations make me wish Jack were here now. I would gladly give up winning the backgammon game to discuss the amazing potential of stem cell therapy, regenerative medicine, and the hope of life without the debilitating symptoms. What a way to spend the day!