Stem cells are special cells that can turn into many different cell types in the body such as heart muscle cells, brain cells, and skin cells. Stem cells are unspecialized cells that have two important characteristics that distinguish them from other cells in the body. First, they can replenish their numbers for long periods through cell division. Second, after receiving certain chemical signals, they can differentiate, or transform into specialized cells with specific functions, such as a heart cell or nerve cell. Stem cells for therapeutic use can be obtained from three potential sources:
Why Are Stem Cells Important?
Stem cells are important for living organisms for many reasons. The Embryonic Stem Cells in developing tissues give rise to the multiple specialized cell types that make up the heart, lung, skin, and other tissues. In some adult tissues, such as bone marrow, muscle, and brain, discrete populations of Adult Stem Cells generate replacements for cells that are lost through normal wear and tear, injury, or disease. It may become possible to use the cells not just in cell-based therapies, but also for screening new drugs and toxins and understanding birth defects
Types Of Stem Cells
There are three main classes of stem cells:
1. Totipotent: it has the potential to become all other types of cells in the body. A fertilized egg is a totipotent.
2. Multipotent: a small number of stem cells can produce only certain types of cells.
3. Pluripotent: stem cells that produce any type of cell in the body except those needed to develop a fetus.
What are Embryonic Stem Cells?
Embryonic stem cells are extracted directly from an embryo before the embryo's cells begin to differentiate. At this stage the embryo is referred to as a blastocyst. There are about 100 cells in a blastocyst, a very large percentage of which are stem cells, which can be kept alive indefinitely, grown in cultures, where the stem cells continue to double in number every 2-3 days. A replicating set of stem cells from a single blastocyst is called a stem cell line because the genetic material all comes from the same fertilized human egg that started it.
Unique Properties Of All Stem Cells
Stem cells have two important characteristics that distinguish them from other types of cells.
1.They are unspecialized cells that renew themselves for long periods through cell division.
2.Under certain physiologic or experimental conditions, they can be induced to become cells with special functions such as the beating cells of the heart muscle or the insulin-producing cells of the pancreas.
All stem cells regardless of their source have three general properties:
1. They are capable of dividing and renewing themselves for long periods
2. They are unspecialized
3. They can give rise to specialized cell types.
The Goal Of Stem Cell Therapy
The goal of any stem cell therapy is to repair a damaged tissue that can't heal itself. This might be accomplished by transplanting stem cells into the damaged area and directing them to grow new, healthy tissue. It is also possible to coax stem cells already in the body to work overtime and produce new tissue.
Stem Cell Therapies Today
Several stem cell therapies are routinely used to treat disease today these include:
•Adult Stem Cell Transplant: Bone Marrow Stem Cell Therapy
•Adult Stem Cell Transplant: Peripheral Blood Stem Cells
• Umbilical Cord Blood Stem Cell Transplant
CELL THERAPY
Cell therapy can be defined as a group of new techniques, or technologies, that rely on replacing diseased or dysfunctional cells with healthy, functioning ones. These new techniques are being applied to a wide range of human diseases, including many types of cancer, neurological diseases such as Parkinson's and Lou Gehrig's Disease, spinal cord injuries, and diabetes.
Replacing dead cells in the retina with new ones may someday cure even presently incurable eye diseases such as glaucoma and macular degeneration. To understand how cell therapy works, it helps to understand the role of cells in the body.
FUNCTIONS OF A CELL
Cells are the basic building blocks of the human body. These tiny structures compose the skin, muscles, bones and all of the internal organs. They also hold many of the keys to how our bodies function. Cells serve both a structural and a functional role in the body, performing an almost endless variety of actions to sustain the body's tissues and organs.
There are hundreds, perhaps thousands, of different specialized cell types in the adult body. All of these cells perform very specific functions for the tissue or organ they compose. For example, specialized cells in the heart muscle "beat" rhythmically through the conduction of electrical signals, while the cells of the pancreas produce insulin to help the body convert food to energy. These mature cells have been differentiated, or dedicated, to performing their special tasks.
Conventional wisdom has long maintained that under normal conditions, once a cell has become specialized, it cannot be changed into a different type of cell. Like the body itself, cells have a finite life span; they eventually die. Most of the body's cells divide and duplicate throughout life, but some cells either don't replenish themselves or do so in such small numbers that they cannot replace themselves fast enough to combat disease.
THEORY BEHIND CELL THERAPY
While cells are indispensable in performing vital functions for the body, they can also exist outside the body. They can live and divide in "cultures," special solutions in test tubes or Petrie dishes. This ability of certain cell types to live isolated from other cells under controlled conditions has allowed scientists to study them independently of the organ or system they are normally a part of.
Through the isolation and targeted manipulation of cells, scientists are finding ways to identify young, regenerating ones that can be used to replace damaged or dead ones in diseased organs. This therapy is similar to the process of organ transplant, only the treatment consists of the transplantation of cells rather than organs. The cells that have shown by far the most promise of supplying diseased organs with healthy new ones are called stem cells.
CELL THERAPY – TODAY
Even though most of the work done in this field has been experimental, most scientists find cell therapy so promising that they believe it is only a matter of time before its use becomes routine. And while many of the hoped-for uses of cell therapy sound futuristic, there are a few forms of this technique that have already been in use for years. Bone marrow transplants are an example of cell therapy in which the stem cells in a donor's marrow are used to replace the blood cells of the victims of leukemia and other cancers.
Cell therapy is also being used in experiments to graft new skin cells to treat serious burn victims, and to grow new corneas for the sight-impaired. In all of these uses, the goal is for the healthy cells to become integrated into the body and begin to function like the patient's own cells. Even though cell therapy is a new science, early results like the above have caused great optimism in the scientific community. However, there are several scientific challenges that must be overcome before we can truly harness the power of stem cells.
CHALLENGES
One of the first challenges that must be overcome for stem cell therapies to become more commonplace is the difficulty of identifying stem cells in tissue cultures, which contain numerous types of cells. While scientists are discovering new cell types almost every day, they estimate that there could literally be thousands of human cell types.
The process of identifying any desired type of stem cell will involve painstaking research. Second, once stem cells are identified and isolated, the right biochemical solution must be developed to cause these progenitor cells to differentiate into the desired cell type. This too will require a great deal of experimentation.
Assuming that the above obstacles have been overcome, new issues arise when the cells are implanted into a person. The cells must be integrated into the patient's own tissues and organs and "learn" to function in concert with the body's natural cells. Cardiac cells that beat in a cell culture, for example, may not beat in rhythm with a patient's own heart cells. And neurons injected into a damaged brain must become "wired into" the brain's intricate network of cells and their connections in order to work properly. Yet another challenge is the phenomenon of tissue rejection. Just as in organ transplants, the body's immune cells will recognize transplanted cells as "foreign," setting off an immune reaction that could cause the transplant to fail and possibly endanger the patient.
Cell recipients would have to take drugs to temporarily suppress their immune systems, which in itself could be dangerous. Yet another concern is the possible risk of cancer. Cancer results when cells lose their internal "brakes" and keep dividing when further proliferation is no longer desirable. Researchers must find a delicate balance between fostering the growth of new cells to replenish damaged tissues and making sure that cells don't overgrow and become cancerous. However, most scientists believe that, with the appropriate research, these obstacles can be overcome and the power of stem cells can be harnessed.
CELL THERAPY – FUTURE
Despite the many challenges before us, most scientists believe that cell therapy will revolutionize medicine. With the use of cell therapies, we may soon have dramatic cures for cancer, Parkinson's, diabetes, kidney disease, multiple sclerosis, macular degeneration and a host of other diseases.
Cell therapies have also shown great promise in helping to repair catastrophic spinal injuries, and helping victims of paralysis regain movement. It is even possible that the human life span could be greatly extended due to the replenishment of tissues in aging organs.
We may even have the ability one day to grow our own organs for transplantation from our own stem cells, eliminating the danger of organ rejection. While we will undoubtedly encounter the limits of cell therapy one day, there is every reason to hope that this revolutionary new approach will result in radically improved ways to treat disease.
Histories & Stories of Successful Stem Cell Therapy Patients
MAN WALKS, COURTESY STEM CELL THERAPY - LIFELINE HOSPITALS, CHENNAI, INDIA
A 23-year-old man, who was paralysed from below the waist, is now able to walk after the first successful stem cell therapy in India for spinal cord injuries was conducted at a hospital here. According to Dr J.S. Rajkumar, chairman, Lifeline Hospitals, the young man, Akbar Ali, suffered serious injuries in his spinal cord when he fell from the fourth floor of a building last October. He was then working at a construction site in Abu Dhabi.
Though he underwent a surgery to stabilise his spinal cord, it was not successful. After he returned to India a month later, he lost sensation in his legs and was paralysed below the waist. He could not control his urine and bowel movements and was thus admitted to Lifeline Hospitals. The doctors there diagnosed him as a patient for autologous stem cell therapy wherein the stem cells from the patient's body are taken and used at the injured spot.
The technology, which is available at the hospital in collaboration from the Nichi-In Centre for Regenerative Medicine, Japan, was applied to Ali’s body. Nearly 100 ml of his bone marrow was removed, harvested and isolated before the stem cells were injected near the injured spot in his spinal cord. The stem cells emit trophic factors, which enable neurons and vessels to grow; a part of them becomes integral to the region, another component becomes part of the growing nerves.
Two months into the therapy, Ali has now regained 50 per cent sensation below his waist. He can control his urine for up to two hours and can also walk. Lifeline doctors said this treatment could be used for paraplegics, but usually worked better on younger people with more recent injuries. The hospital is presently examining the use of this therapy in treating cardiac problems, liver failure, diabetes, multiple sclerosis and Parkinson’s disease.
Of the various sources of stem cells, the autologous stem cell therapy was used by the hospital as there was no risk of rejection nor was there any concern of medical ethics. Doctors say that preserving stem cells is a kind of bio-insurance for an entire family as the stem cells could help in the treatment of the person’s siblings, parents and even grandparents. While preserved cord blood stem cells are a perfect match for the child from whose umbilical cord it was collected, there is only a 25 per cent chance of it being a perfect match for other family members.
The Pros & Cons of Stem Cell Research
To understand the pros and cons of stem cell research, one must first understand where stem cells come from.
UNDERSTANDING STEM CELLS
There are three main sources for obtaining stem cells - Adult cells,Cord cells and Embryonic cells.
Adult stem cells can be extracted either from bone marrow or from the peripheral system.Stem cells taken from the umbilical cord are a second very rich source of stem cells.
The pros and cons of stem cell research come to the surface when we examine the third source of stem cells - embryonic cells.
WHAT IS THE CONTROVERSY ALL ABOUT?
Most critics of embryonic stem cell research argue that the research is unethical because extracting stem cells destroys a human embryo.
Against this, embryonic research advocates argue that the tiny blastocyst has no human features.
Thus, the debate centers on the status of human embryos. Are they clusters of cells or human individuals? Most people tend to gravitate to a position between these two extremes, but the discussion is unresolved in policy and legal debates.
WHAT IS GLOBE HEALTH TOURS ATTITUDE
Presently we do not advocate any form of stem cell therapy using embryonic stem cell tissue. We are not aware of any clinics or hospitals using embryonic stem cells for the purposes of treatment.
We abide by carefully evaluated protocols for treatment and until there is a concensus and clear set of guidelines for the use of embryonic stem cells, they will not form part of the offering.
What are Haematopoietic Stem Cells?
Stem cells are blood cells at the earliest stage of development in the bone marrow. Within the bone marrow, stem cells develop into the different blood cells (Red Blood Cells, White Blood cells and Platelets).When cells fully mature, they are released into the bloodstream.Normally, most of the stem cells are in the bone marrow. It is possible to stimulate the stem cells to move into the bloodstream using injections. The Blood Stem Cells can be collected from the bone marrow or bloodstream. These Blood Stem Cells have the ability to produce specialized cells and reproduce themselves.
Sources of Haematopoietic Stem Cells
ALLOGENIC TRANSPLANT: Compatible family member or an unrelated donor.
AUTOLOGOUS TRANSPLANT: Patients own cells collected previously and suitably stored.
SYNGENIC TRANSPLANT: An identical twin.
What Conditions can be treated?
The Following includes, but are not limited to a small list of conditions which have proven to be responsive to Cord Blood Stem Cell Disease Therapy.
ADRENAL DISEASE