About Stem Cells & Diseases

Amyotrophic Lateral Sclerosis (ALS) is a devastating disease that progressively destroys nerve cells, called motor neurons, in the brain and the spinal cord, eventually causing paralysis and death. Baseball great Lou Gehrig first brought national attention to the disease in 1939 when he retired from baseball after being diagnosed with ALS. He died two years later, but ALS is still commonly referred to as “Lou Gehrig’s disease.”

People who have ALS steadily lose their ability to control muscle movement. Patients in the later stages become totally paralyzed, although their minds are often unaffected. The average life expectancy of a person with ALS is two to five years from time of diagnosis. Many ALS sufferers die within a few years due to failure of the nerve cells that control breathing.

The cause of ALS is unknown and there is currently no cure. One FDA-approved drug, Rilutek, helps slow the progression of ALS, but no existing treatment halts or reverses the disease.

Human and Social Costs

An estimated 30,000 Americans suffer from ALS. Every day, an average of 15 people is diagnosed with ALS – more than 5,600 people per year.

The financial cost to families of persons with ALS is extremely high. In advanced stages of the disease, caring for an ALS patient can cost up to $200,000 a year, imposing an enormous financial and emotional toll on affected families.

More than 50 years of research on adult stem cells, taken from adult tissues, has produced lifesaving treatments such as bone marrow transplants for leukemia patients. Adult stem cells are likely to provide additional cures for some diseases in the coming years.

However, the new frontier in stem cell research involves early, or “embryonic,” stem cells (ES cells). Unlike adult stem cells, ES cells have the potential to turn into and regenerate any type of cell or tissue in the human body. As a result, ES cells could provide cures for many currently incurable or common diseases and injuries that cannot be cured with adult stem cells, or more effective treatments than adult stem cells may provide.

Recent studies indicate that ES cells can generate healthy new nerve cells. Thus, they could someday be transplanted into a patient’s body to treat or cure diseases like ALS by generating healthy cells to replace diseased and damaged cells.

There are two basic sources of ES cells for such potential therapies. One source is the leftover embryos at fertility clinics that would otherwise be discarded and destroyed. ES cells can also be produced with Somatic Cell Nuclear Transfer (SCNT), a process that uses a patient’s own cells and an unfertilized human egg to make ES cells. SCNT has the added advantage of producing ES cells that will automatically match the patient’s genetic makeup. As a result, SCNT avoids the need to find a genetically matching donor and the problem of immune system rejection, two limitations associated with donated adult and ES cells.

SCNT has also given medical researchers a method of growing cells that have the defects associated with a disease in a laboratory setting. This use of SCNT provides new ways to study how a disease like ALS progresses at the cellular level and to test the effectiveness of new drugs or other treatments that may cure or slow the progress of the disease.

Another option being studied is the use of ES cells to develop astrocytes, special cells that nourish and support brain and spinal nerve cells. These astrocytes could, in turn, help the patient’s own body regenerate nerve cells and reduce symptoms associated with ALS.

Recent animal studies by medical researchers at Johns Hopkins University found that ES cell transplants restored movement to rats paralyzed with an ALS-like syndrome. Those studies also indicated that ES cells may not only replace damaged cells, they may also act as rejuvenating “pumps,” secreting growth factors that revitalize damaged neural micro-environments.

Studies published this year by scientists at Dalhousie University in Halifax demonstrate that ES cells in experimental animals can be directed to differentiate into cells with the properties of functional motor neurons, a finding that may lead to ES cell therapy for motor neuron damage like that seen in ALS.

The consensus of the medical and patient community is that all types of stem cell research should be pursued in the effort to find cures for diseases like ALS, and that ES cells can play an important role in this effort.

That’s why ES cell research is strongly supported by the overwhelming majority of medical researchers, medical organizations like the American Medical Association and disease and patient advocacy groups like the ALS Association, ALS Therapy Development Foundation, Project ALS and Jack Orchard ALS Foundation.

Cancer is basically out-of-control cell division and growth that destroys surrounding tissue and organs. Cancer often turns into a tumor. Some forms, like leukemia, affect the blood and blood-forming organs and circulate through other tissues where they grow. Cancer cells often develop because of damage to the genetic material in a person’s cells. This damage can be inherited or caused by exposure to something in the environment, like smoking or hazardous chemicals.

Different types of cancer can behave very differently. For example, lung cancer and breast cancer grow at different rates and respond to different treatments. That is why people with cancer need treatments that are aimed at their particular kind of cancer. Major types of treatment for cancer include surgery, radiation, chemotherapy and stem cell therapies, such as bone marrow transplants.

The use of bone marrow transplants to treat leukemia, pioneered in the 1970s, was the first major stem cell therapy breakthrough. Bone marrow transplants are now being used to treat other types of cancer, such as breast tumors and ovarian cancer. In fact, various stem cell therapies are playing an increasingly important role in treating cancer – and in helping to regenerate cells and tissues that are damaged by chemotherapy and radiation treatments for cancer.

Human and Social Costs

Cancer is the second leading cause of death in the U.S. Although much progress has been made in treating cancer and survival rates have increased, cancer still kills more than 550,000 Americans every year.

More than one million people are diagnosed with cancer each year and anyone can get cancer at any age. However, about 77% of all cancers are diagnosed in people age 55 and older. Nearly half of all men and a little over one-third of all women in the U.S. will develop cancer during their lifetimes.

The direct and indirect financial costs of cancer are high. In 2002, the National Institutes of Health estimated that the annual costs of cancer in the U.S. exceeded $189 billion. These costs included $64 billion in direct health expenditures, $16 billion in lost productivity due to illness, and $109 billion in lost productivity due to premature deaths.

The Potential for Stem Cell Cures

Bone marrow transplants – which are essentially transplants of adult blood-forming stem cells found in bone marrow – have been used for decades to save the lives of patients suffering from leukemia and other blood-related cancers. Transplants of blood-forming stem cells are also being used to help replenish patients’ immune systems following cancer treatments involving chemotherapy and radiation.

Although adult stem cells have provided treatments for some types of cancer and other diseases, the new frontier in stem cell research involves early, or “embryonic,” stem cells (ES cells). Unlike adult stem cells, ES cells have the potential to turn into and regenerate any type of cell or tissue in the human body. As a result, ES cells could provide cures for many currently incurable or common diseases and injuries that cannot be cured with adult stem cells, or more effective treatments than adult stem cells may provide.

There are two basic sources of ES cells for such potential therapies. One source is the leftover embryos at fertility clinics that would otherwise be discarded and destroyed. ES cells can also be produced with Somatic Cell Nuclear Transfer (SCNT), a process that uses a patient’s own cells and an unfertilized human egg to make ES cells. SCNT has the added advantage of producing ES cells that will automatically match the patient’s genetic makeup. As a result, SCNT avoids the need to find a genetically matching donor and the problem of immune system rejection, two limitations associated with donated adult and ES cells.

A key limitation of donated bone marrow transplants is the need to find a genetically compatible donor. If the donated cells are not a good genetic match with the patient, they will be rejected by the patient’s immune system. Unfortunately, about 70% of patients who need bone marrow transplants are unable to find a compatible donor. SCNT could help address this problem by using a patient’s own cells to produce blood-forming stem cells that will be accepted by the patient’s immune system.

SCNT has also given medical researchers an important new tool for studying the development of different types of cancer cells in a laboratory setting. This use of SCNT provides a new way to test the safety and effectiveness of new chemotherapy drugs or other treatments. It can also help researchers determine the cellular changes that cause various cancers, and possibly point the way to reversing those changes.

The consensus of the medical and patient community is that all types of stem cell research should be pursued in the effort to find cures for cancer and other diseases, and that ES cells can play an important role in this effort.

That’s why embryonic stem cell research is strongly supported by the overwhelming majority of medical researchers; medical organizations like the American Medical Association and disease and patient advocacy groups like the American Association for Cancer Research, Cancer Research and Prevention Foundation, Prostate Cancer Foundation, Leukemia & Lymphoma Society, Friends of Cancer Research, National Prostate Cancer Coalition and Women’s Cancer Research Fund.

Diabetes is a group of diseases characterized by high levels of blood glucose resulting from defects in insulin production, insulin action, or both. Insulin is a cellular protein that regulates glucose levels in the blood.

Type 1 diabetes is often called “juvenile diabetes” because it generally appears during childhood or adolescence. It develops when the body’s immune system mistakenly destroys the insulin-producing islet cells of the pancreas, a small gland behind the stomach. As a result, the body is unable to properly utilize energy in food or control sugar levels in the blood stream.

Type 1 diabetics must endure many painful insulin injections each day in order to live and function normally and, at present, there is no cure. However, recent research indicates that a cure may be possible through transplants of pancreatic islet cells.

Type 2 diabetes usually begins as insulin resistance, a disorder in which the cells do not use insulin properly. As the need for insulin rises, the pancreas gradually loses the ability to produce it. This type of diabetes usually occurs later in life, affecting 90% of patients diagnosed with diabetes.

Type 2 diabetes is associated with older age, obesity, family history of diabetes, physical inactivity and race/ethnicity. African Americans, Hispanic/Latino Americans, Native Americans, and some Asian Americans, Native Hawaiian or other Pacific Islanders are at particularly high risk for Type 2 diabetes. Type 2 diabetes is also increasingly being diagnosed in children and adolescents. Current treatment includes using diabetes medicines, making wise food choices, exercising regularly, taking aspirin daily, and controlling blood pressure and cholesterol.

Diabetes can lead to many serious long-term health problems and early death. It can cause blindness, kidney failure and severe problems involving the gums and teeth. It can also cause nerve damage and blood flow problems that result in impaired sensation or pain in the feet or hands and amputation of limbs. One of the most serious problems caused by diabetes is heart disease. People who have diabetes are more than twice as likely to develop heart disease or a stroke as people without diabetes.

Human and Social Costs

Over 18 million people in the U.S., or 6.3% of the population, have diabetes. Over one million new cases are diagnosed every year. Diabetes was the sixth leading cause of death listed on U.S. death certificates in 2000. The American Diabetes Association estimates that diabetes contributes to over 200,000 deaths annually nationwide. However, total deaths caused by diabetes are probably under-reported because it ultimately causes other health problems that may be listed as the cause of death.

In 2000, a total of 129,183 people with diabetes underwent dialysis or kidney transplantation. About 60% to 70% of people with diabetes have mild to severe forms of nervous system damage. The results of such damage include slowed digestion of food in the stomach, carpal tunnel syndrome and other nerve problems.

It’s estimated that diabetes costs Americans a total of $132 billion annually, including $92 billion in direct medical costs and $40 billion in costs related to disability, work loss and premature death. Diabetes accounts for one of every four Medicare dollars spent in the U.S.

The Kaiser Family Foundation estimates that 6% of adults between the ages of 18 and over 75 in our state have diabetes. The majority of adults diagnosed with diabetes are between the ages of 45 and 64 (43%) and age 65 and older (42%). Most of these older patients have Type 2 diabetes.

The Potential for Stem Cell Cures

More than 50 years of research on adult stem cells, taken from adult tissues, has produced such lifesaving treatments as bone marrow transplants for leukaemia patients. And, adult stem cells are likely to provide additional cures for some diseases in the years ahead.

However, the new frontier in stem cell research involves early, or “embryonic,” stem cells (ES cells). Unlike adult stem cells, ES cells have the potential to turn into and regenerate any type of cell or tissue in the human body. As a result, ES cells could provide cures for many currently incurable or common diseases and injuries that cannot be cured with adult stem cells, or more effective treatments than adult stem cells may provide.

There are two basic sources of ES cells for such potential therapies. One source is the leftover embryos at fertility clinics that would otherwise be discarded and destroyed. ES cells can also be produced with Somatic Cell Nuclear Transfer (SCNT), a process that uses a patient’s own cells and an unfertilized human egg to make ES cells. SCNT has the added advantage of producing ES cells that will automatically match the patient’s genetic makeup. As a result, SCNT avoids the need to find a genetically matching donor and the problem of immune system rejection, two limitations associated with donated adult and ES cells.

Indications that ES cells could benefit diabetes patients have been provided by a number of recent studies. For example, researchers at Stanford University have successfully turned mouse ES cells into insulin-making tissue that kept diabetic mice alive.

Other research has shown that insulin-producing islet cells can be transplanted into patients with Type 1 diabetes and that such transplants could potentially provide a cure. However, the only current source of replacement islet cells is from human cadavers and not enough donated islet cells are available from this source to treat the many children and adults who have Type 1 diabetes. In addition, because donated islet cells are not a perfect genetic match with the patient’s DNA, patients who receive donated islet cells must take powerful drugs to prevent rejection. These drugs have severe and potentially fatal side effects and rejection often occurs despite the medication.

SCNT could help overcome these limitations and revolutionize the treatment of juvenile diabetes by providing a way to make virtually unlimited supplies of transplantable islet cells that match a patient’s DNA.

In the future, transplants of ES cells could also help people who suffer from Type 2 diabetes. For example, ES cells could be used to help repair tissues and organs that are damaged by effects of Type 2 diabetes and alleviate some of the health problems associated with this disease.

SCNT could also play an important role in developing future “gene therapy” treatments for inherited diseases like Type 1 diabetes, which develop because the patient has an abnormal or malfunctioning gene. If the gene that causes a disease can be identified, scientists could take a patient’s somatic cell, such as a skin cell, and replace the defective gene with a normal gene inserted using recombinant DNA techniques. The “corrected” cell could then be used in the SCNT procedure to generate stem cells with normally functioning genes. These could then be directed to develop into islet cells and put back into the patient’s body, potentially providing a cure. This technique would overcome some of the most difficult hurdles facing gene therapy today.

In addition, SCNT has given medical researchers a method of growing cells that have the defects associated with a disease in a laboratory setting. This use of SCNT provides new ways to study how a disease like diabetes progresses at the cellular level and to test the effectiveness of new drugs or other treatments that may cure or slow the progress of the disease.

The consensus of the medical and patient community is that all types of stem cell research should be pursued in the effort to find cures for diseases like diabetes, and that ES cells can play an important role in this effort.

That’s why ES cell research is strongly supported by the overwhelming majority of medical researchers; medical organizations like the American Medical Association; and disease and patient advocacy groups like the American Diabetes Association, Juvenile Diabetes Research Foundation and Diabetes Research Institute Foundation.

There are many different diseases that affect the heart and other parts of the cardiovascular system, including:

  • Coronary artery disease (CAD)
  • Heart attack (acute myocardial infarction)
  • Stroke
  • Heart valve disease
  • Congenital heart disease
  • Heart muscle disease (cardiomyopathy)
  • Pericardial disease
  • Aorta disease and Marfan syndrome
  • Vascular disease (blood vessel disease)

Coronary artery disease occurs when the arteries that supply blood to the heart muscle (coronary arteries) become hardened and narrowed due to the build-up of plaque on the inner lining of the arteries (atherosclerosis). Among other things, this can cause angina, a heart attack or heart failure.

Traumatic cardiovascular conditions such as a heart attack (acute myocardial infarction); damage portions of the heart and can be fatal. People who survive a heart attack often face a diminished quality of life and long-term health problems.

Stroke is caused by the blockage or rupture of blood vessels that supply the brain, causing a sudden loss of oxygen to the victim’s brain cells. Brain cells within the vicinity of the broken vessel are damaged within minutes and begin to die within hours. Stroke victims often experience a loss of body function and, depending upon the brain region affected, can suffer partial paralysis and sensory defects.

Other cardiovascular diseases also create serious short and long-term problems for their victims.

Although great progress has been made in developing surgical and drug treatments for many heart and cardiovascular conditions, they are still the top causes of disease and death in our country.

Human and Social Costs

About 61 million Americans (almost one-fourth of the population) have some form of cardiovascular disease.

About 950,000 Americans die of some type of cardiovascular disease each year, accounting for nearly one in four deaths in our country – or one death every 33 seconds. Cardiovascular disease is a leading cause of premature, permanent disability among working adults. Almost 6 million hospitalizations each year are due to cardiovascular disease.

The American Heart Association estimates that 3.5% of the U.S. population age 20 and over has had a heart attack. Based on current population figures, this would amount to over 7 million people. The American Heart Association estimates that 2% of the U.S. population, or 5.9 million people, have suffered a stroke.

Although heart disease and stroke are often thought to primarily affect men and older people, they are also major killers of women and people in the prime of life. Looking at specific age groups, cardiovascular disease is the number one killer for people ages 65 and older, number two for ages 0-14 and 25-64, and number four for ages 15-24.

The number of cardiovascular disease patients and the economic effects of cardiovascular disease on the U.S. health care system are increasing as our population ages. In 2003, the cost of heart disease and stroke was projected to be about $351 billion, including $209 billion for health care expenditures and $142 billion for lost productivity from death and disability.

The Potential for Stem Cell Cures

Recent research indicates that stem cells could play an important role in repairing the cell and tissue damage caused by heart and cardiovascular diseases, and could someday lead to breakthrough cures and therapies. For example, scientific studies indicate that stem cells can transform into the heart cells damaged by cardiovascular disease (e.g. heart muscle or valve cells). Thus, stem cell transplants could be used to regenerate damaged heart tissue and help improve heart function.

More than 50 years of research on adult stem cells, taken from adult tissues, has produced such lifesaving treatments as bone marrow transplants for leukemia patients. And, adult stem cells are likely to provide additional cures for some diseases in the years ahead.

However, the new frontier in stem cell research involves early, or “embryonic,” stem cells (ES cells). Unlike adult stem cells, ES cells have the potential to turn into and regenerate any type of cell or tissue in the human body. As a result, ES cells could provide cures for many currently incurable or common diseases and injuries that cannot be cured with adult stem cells, or more effective treatments than adult stem cells may provide.

There are two basic sources of ES cells for such potential therapies. One source is the leftover embryos at fertility clinics that would otherwise be discarded and destroyed. ES cells can also be produced with Somatic Cell Nuclear Transfer (SCNT), a process that uses a patient’s own cells and an unfertilized human egg to make ES cells. SCNT has the added advantage of producing ES cells that will automatically match the patient’s genetic makeup. As a result, SCNT avoids the need to find a genetically matching donor and the problem of immune system rejection, two limitations associated with donated adult and ES cells.

Researchers at Memorial Sloan-Kettering Cancer Center have used ES cell transplants to repair congenital heart defects in mice. Researchers at the Cardiovascular Research Institute in New York recently reported that heart muscle cells derived by SCNT were successfully transplanted into the hearts of animals, and that the cells divided and formed a mechanically meaningful architecture following heart attack. They also observed some restoration of normal heart function, a remarkable finding given that these animals received transplants that were 10 times smaller than comparable adult stem cell transplants. Such animal studies could lead to the application of similar ES cell therapies for humans.

Recent studies indicate that ES cell transplants could also be used in the future to help repair cell damage caused by stroke or, since certain types of stem cells have been shown to migrate to brain regions inflamed by stroke, they could be used to “transport” anti-inflammatory medicines used after stroke injury directly to the damaged area.

SCNT also has the potential to provide a way to use a patient’s own cells to regenerate blood vessels and repair injured organs, such as hearts, with cells that will be accepted by the patient’s body. This could provide a vitally-needed alternative to transplants of donated tissues and organs, which are almost always in short supply, limited by the need to find a donor genetic match, and subject to immune rejection problems.

In addition, SCNT has given medical researchers a method of growing cells that have the defects associated with a disease in a laboratory setting. This use of SCNT provides new ways to study how some cardiovascular diseases progress at the cellular level and to test the effectiveness of new drugs or other treatments that may cure or slow the progress of those diseases.

The consensus of the medical and patient community is that all types of stem cell research should be pursued in the effort to find cures for diseases and injuries – including heart attacks, stroke and other cardiovascular diseases – and that ES cells can play an important role in this effort.

That’s why ES cell research is strongly supported by the overwhelming majority of medical researchers; medical organizations, like the American Medical Association, American Society of Hematology and National Medical Association; by leading research, like the Stowers Institute for Medical Research; and by dozens of disease and patient advocacy groups.

HELPFUL RESOURCES

Age-related macular degeneration (AMD) is a disease caused by damage or breakdown of the macula, the small part of the eye’s retina that is responsible for our central vision. This condition affects both distance and close vision and can make some activities (like threading a needle or reading) very difficult or impossible.

In some people, AMD advances so slowly that vision loss does not occur for a long time. In others, the disorder progresses faster.

There are two types of macular degeneration: wet and dry. Dry AMD is much more common and accounts for nearly 90 percent of all cases. The wet type, while rare, tends to progress much more rapidly.

The National Institutes of Health’s National Eye Institute classifies four major risk factors for AMD. Age over 55, smoking; family history and race of Caucasian descent increase the risk of getting AMD.

Despite the limited vision, AMD does not cause complete blindness. Side (peripheral) vision is generally unaffected by macular degeneration.

Human and Social Costs

Macular degeneration is the leading cause of severe vision loss in people over 65, and is the leading cause of legal blindness in people aged 55 years and older in the United States.

According to the Macular Degeneration Association, AMD affects more than 9.1 million individuals in the United States. That number is expected to increase to nearly 20 million by 2020, due to the rapid aging of the U.S. population.

The Potential for Stem Cell Cures

In AMD, the layers of cells that support the photoreceptors are destroyed. Without this support system, the photoreceptors, the cells that actually allow us to sense light, start to malfunction.

Researchers are looking at various methods of replacing this layer of support cells called RPE (retinal pigment epithelial) cells. Some are using embryonic stem cells as a starting point to generate new RPE cells; others are using stem cells obtained by reprogramming adult cells to be like embryonic cells, which could potentially come from the patients’ themselves.

Some researchers are looking to treat degenerative eye diseases simply by activating stem cells that exist in adult retinas.

Parkinson’s disease is a progressive disorder of the central nervous system. It occurs when the group of brain cells that produce an important chemical called dopamine begin to malfunction and eventually die. Dopamine is a neurotransmitter, or chemical messenger, that transports signals to the parts of the brain that control movement initiation and coordination.

In a patient suffering from Parkinson’s, the dopamine-producing brain cells begin to die, for reasons that are still unknown. As a result, the amount of dopamine produced in the brain decreases. This causes various problems, including body tremors, rigidity or stiffness of limbs or trunk, slowed movement and impaired balance and coordination.

Some of the symptoms of Parkinson’s can be controlled with medications. However, no existing treatments provide a cure for Parkinson’s or reverse the damage it causes.

Human and Social Costs

An estimated one million Americans suffer from Parkinson’s disease. One person in 200 will be diagnosed with Parkinson’s, and one out of 100 individuals over age 65 has the disease. Studies also show that about 10% of elderly people who pass away from a non-brain illness have pre-symptomatic Parkinson’s, indicating that there may be an additional 5 to 10 million people who are unaware that they are developing Parkinson’s.

The frequency of Parkinson’s disease is highest in the over-60 age group, and the number of people who have the disease is expected to increase steadily as the Baby Boom population ages. In recent years, there has also been an alarming increase of younger Parkinson’s patients.

It is estimated that a Parkinson’s patient spends an average of $2,500 a year for medications. After factoring in office visits, Social Security payments, nursing home expenditures and lost income, the total cost of Parkinson’s in the US is estimated to exceed $5.6 billion annually.

The Potential for Stem Cell Cures

More than 50 years of research on adult stem cells, taken from adult tissues, has produced such lifesaving treatments as bone marrow transplants for leukemia patients. And, adult stem cells are likely to provide additional cures for some diseases in the years ahead.

However, the new frontier in stem cell research involves early, or “embryonic,” stem cells (ES cells). Unlike adult stem cells, ES cells have the potential to turn into and regenerate any type of cell or tissue in the human body. As a result, ES cells could provide cures for many currently incurable or common diseases and injuries that cannot be cured with adult stem cells, or more effective treatments than adult stem cells may provide.

There are two basic sources of ES cells for such potential therapies. One source is the leftover embryos at fertility clinics that would otherwise be discarded and destroyed. ES cells can also be produced with Somatic Cell Nuclear Transfer (SCNT), a process that uses a patient’s own cells and an unfertilized human egg to make ES cells. SCNT has the added advantage of producing ES cells that will automatically match the patient’s genetic makeup. As a result, SCNT avoids the need to find a genetically matching donor and the problem of immune system rejection, two limitations associated with donated adult and ES cells.

Recent research indicates that transplants of ES cells or neurons produced with ES cells could help alleviate the symptoms of Parkinson’s and may provide the hope for a cure.

In an animal study conducted by researchers at the Harvard Medical School, stem cells repaired the injured nerve cells of aged mice whose brains were compromised by the equivalent of Parkinson’s disease. And, in January 2005, a study by Japanese scientists found that ES cell transplants reversed Parkinson’s symptoms in monkeys.

Much more research is needed to determine if any type of stem cell transplants will provide a way to alleviate or cure Parkinson’s disease in humans. But it is clearly a promising new possibility and, for future stem cell transplant therapies, ES cells offer some key advantages.

In addition, SCNT has given medical researchers a method of growing cells that have the defects associated with a disease in a laboratory setting. This use of SCNT provides new ways to study how a disease like Parkinson’s progresses at the cellular level and to test the effectiveness of new drugs or other treatments that may cure or slow the progress of the disease.

The consensus of the medical and patient community is that all types of stem cell research should be pursued in the effort to find cures for diseases like Parkinson’s, and that ES cells can play an important role in this effort.

That’s why ES cell research is strongly supported by the overwhelming majority of medical researchers; medical organizations like the American Medical Association; disease and patient advocacy groups like the Michael J. Fox Foundation for Parkinson’s Research, Parkinson’s Action Network, Take Charge! Cure Parkinson’s, American Parkinson’s Disease Association, Parkinson’s Disease Foundation, Parkinson’s Institute – and by well-known stem cell advocates who suffer from Parkinson’s like Michael J. Fox and Muhammad Ali.

Spinal cord injury (SCI) resulting from accidents, gunshots or other traumas is a tragedy that affects hundreds of thousands of people of all ages. Vehicular accidents cause about 44% of these injuries. Nearly one-quarter are the result of violence and 22% are the result of falls. Sports injuries account for 7% of spinal cord injuries. The remaining 1% of spinal cord injuries results from work-related or other accidents.

Many SCI victims tend to be young adults and most are male. About 53% of spinal cord injuries occur among persons in the 16 to 30 year age group. Overall, 81% of all persons suffering from spinal cord injuries are male.

Spinal cord injuries involve the damage and destruction of nerve fibers within the spinal cord, a central component of the communication system our brains use to direct the functioning of our bodies. Breaks in this communication system lead to paralysis and diminished or absent control of basic body functions.

The location of damage along the spinal cord often determines the areas affected by spinal injury. For example, individuals experiencing a spinal break along the lower back may retain the use of their upper extremities. Unfortunately, fewer faculties are retained if the break site is closer to the head and neck. Patients injured very near to the top of the spinal cord will lose their ability to breathe on their own in addition to being immobilized.

Human and Social Costs

Paraplegia (losses of movement and sensation in the lower body) affects 47% of the SCI population and 52% are affected by quadriplegia (losses of movement and sensation in both the arms and legs).

Approximately 250,000 to 400,000 people in the U.S. have spinal cord injuries. Every year, approximately 11,000 more Americans sustain new spinal cord injuries – amounting to 30 new injuries every day.

Spinal cord injuries cost the nation at least $9.7 billion per year for medical care, equipment and disability support. Trauma and rehabilitation costs alone are almost $250,000 for each SCI patient. Additional lifetime costs incurred by SCI individuals average $400,000 and can reach as high as $2.1 million depending on the extent of injury.

As with other devastating diseases and injuries, the emotional costs to SCI sufferers and their families are extremely high and cannot be quantified in terms of dollars and cents.

The Potential for Stem Cell Cures

More than 50 years of research on adult stem cells, taken from adult tissues, has produced such lifesaving treatments as bone marrow transplants for leukemia patients. And, adult stem cells are likely to provide additional cures for some diseases and injuries in the years ahead.

However, the new frontier in stem cell research involves early, or “embryonic,” stem cells (ES cells). Unlike adult stem cells, ES cells have the potential to turn into and regenerate any type of cell or tissue in the human body. As a result, ES cells could provide cures for many currently incurable or common diseases and injuries that cannot be cured with adult stem cells, or more effective treatments than adult stem cells may provide.

There are two basic sources of ES cells for such potential therapies. One source is the leftover embryos at fertility clinics that would otherwise be discarded and destroyed. ES cells can also be produced with Somatic Cell Nuclear Transfer (SCNT), a process that uses a patient’s own cells and an unfertilized human egg to make ES cells. SCNT has the added advantage of producing ES cells that will automatically match the patient’s genetic makeup. As a result, SCNT avoids the need to find a genetically matching donor and the problem of immune system rejection, two limitations associated with donated adult and ES cells.

Various animal studies conducted in recent years indicate that ES cell transplants could be used to repair and regrow spinal cord nerve fibers – and could someday allow SCI victims to walk again. Much additional research is needed to determine if this hope can be turned into a reality. But the potential is clear.

This potential has been dramatized by several recent studies in which mice and rats with paralyzed legs have regained the ability to move their legs again after receiving transplants of ES cells.

For example, researchers at Johns Hopkins have shown that injections of ES cells into the fluid around the spinal cord of paralyzed rats clearly improved the animals’ ability to control their hind limbs.

It will take years of additional research to determine if any stem cell therapies can lead to similar results in humans. However, the consensus of the medical and patient community is that all types of stem cell research should be pursued in the effort to find a way to repair spinal cord injuries, and that ES cells can play an important role in this effort.

That’s why ES cell research is strongly supported by the overwhelming majority of medical researchers; medical organizations, like the American Medical Association; and disease and patient advocacy groups like the Christopher Reeve Paralysis Foundation, National Council on Spinal Cord Injury, Daniel Heumann Fund for Spinal Cord Research, Research for Cure of Spinal Cord Injury, United Spinal Association, Cure Paralysis Now and Paralysis Project of America.