What is a Stem Cell?

A stem cell is essentially a "blank" cell, capable of becoming another more.
 
 

 
Stem Cell Cures
 
Adult stem cells are a "natural" solution. They naturally exist in our bodies, and they provide a natural repair mechanism for many tissues of our bodies. They belong in the microenvironment of an adult body, while embryonic stem cells belong in the microenvironment of the early embryo, not in an adult body, where they tend to cause tumors and immune system reactions.
 
Most importantly, adult stem cells have already been successfully used in human therapies for many years. As of this moment, NO therapies in humans have ever been successfully carried out using embryonic stem cells. New therapies using adult type stem cells, on the other hand, are being developed all the time. Here are but a few of the many examples of success stories using adult stem cells.
 
Adult Stem Cells
 
The primary role of adult stem cells in humans is to maintain and repair the tissue in which they are found. While we call them adult stem cells, they are more accurately called somatic (from the Greek word soma = body) stem cells, because they come from not only adults, but other sources.
 
Adult type stem cells come from:
 
• Umbilical Cords, Placentas and Amniotic Fluid—Adult type stem cells can be derived from various pregnancy-related tissues.
• Adult Tissues—In adults, stem cells are present within various tissues and organ systems. These include the bone marrow, liver, epidermis, retina, skeletal muscle, intestine, brain, dental pulp, and elsewhere. Even fat obtained from liposuction has been shown to contain significant numbers of adult type stem cells.
• Cadavers—Neural stem cells have been removed from specific areas in post-mortem human brains as late as 20 hours following death.
There are vast amounts of information about stem cells and weeding through it all can be daunting for many of us. This fact sheet provides a clear overview of some stem cell basics and will allow you to move on towards further reading in areas that spark your interest.
 
Unique Properties of Stem Cells
 
Stem cells have several unique properties that separate them from other cells:
 
•    They are unspecialised cells.
•    They can proliferate or self-renew, which means they are capable of replenishing themselves for long periods of time by dividing.
•    They can differentiate into specialised cells such as a nerve or heart cell.
Potency of Stem Cells
A stem cell's potency is a term used to denote its ability to give rise to other cells in the body. Stem cells can be separated into several potency categories:
•    Totipotent stem cells: they can differentiate into any type of cell in the human body, including the placenta.
•    Pluripotent stem cells: they descend from totipotent stem cells and after several days, can differentiate into any type of cell except for totipotent stem cells.
•    Multipotent stem cells: these descend from pluripotent stem cells and can differentiate into many cell lines within a specific type of tissue.
•    Unipotent stem cells: this type of stem cells is a descendant of a multipotent stem cell and can give rise to a single cell type.
Sources of Stem Cells
Stem cells may be derived from several sources and research is currently ongoing for therapeutic use of stem cells from all sources. The isolation and extraction of stem cells allows them to be categorised as:
•    Embryonic stem cells: they are extracted from embryos and are thought to hold the most potential, because these cells can give rise to virtually any specialised cell in the human body.
•    Adult stem cells: these are present in adult tissues such as the bone marrow, brain and blood but are limited in potential relative to embryonic stem cells.
•    Cord blood stem cells: this source of stem cells is derived from cord blood and is thought to hold enormous potential in treating disease.
 
Benefits of Stem Cells
 
Stem cells are currently used to treat cancers such as leukaemia. You may be familiar with the concept of bone marrow transplants, which have been used for decades now to provide a healthy source of cells in the body. Other diseases that stem cells may help include:
 
•    Parkinson's disease
•    Stroke
•    Spinal cord injuries
•    Retinal diseases
•    Alzheimer's disease
•    Type I diabetes
 
Below are some examples of stem cell cures
 
Spinal Cord Injury                                                                                                                                            Jacki Rabon                                                                                                                                                      Jacki, 18, suffered an injury to her spine in August, 2003 that left her paralyzed. She was treated in Portugal by Dr. Carlos Lima with her own adult stem cells derived from olfactory mucosa. Dr. Lima's work using adult stem cells to treat spinal cord injuries, such as the treatment Jacki received, will be published this week in the June 24th issue of the peer-reviewed Journal of Spinal Cord Medicine. Jacki is from Waverly, Illinois.
 
Leukemia                                                                                                                                                     Patrizia Durante
Patrizia was diagnosed with acute leukemia six months into her pregnancy. Her daughter, Victoria Angel, was born healthy, but Durante was given only six months to live. The stem cells from the blood of her daughter's umbilical cord were used for a transplant. Several years later, Durante is in full remission. "She saved her mommy," Durante told reporters. "She's a little miracle. That's why we named her Victoria Angel. She's my little angel."
 
Krabbe's Leukodystrophy                                                                                                                             Gina Rugari
Gina was born with Krabbe's leukodystrophy. This is a rare, degenerative enzyme disorder of the nervous system, in which the baby shows initial signs of irritability and developmental delay or regression. Seizures and fevers often follow, then blindness and deafness until the baby dies, usually before age 2. Gina was tested for Krabbe's leukodystrophy shortly after she was born, because she had a brother who had died from the disease. Doctors treated Gina with chemotherapy to destroy her immune system, and introduced new umbilical cord blood stem cells from a closely matched donor. The transplanted cells produced the missing enzyme. Her body accepted the cells, and she is thriving several years after the transplant.
 
Parkinson's Disease                                                                                                                          Dennis Turner
Dennis was diagnosed with Parkinson's Disease and by early 1991 he suffered extreme shaking of the right side of his body and became unable to use his right arm. Neurosurgeon Dr. Michele Levesque removed a small tissue sample from Mr. Turner's brain, and isolated adult neural stem cells. He multiplied and matured these cells into nerve cells, and injected them back into the left side of Mr. Turner's brain, which controls the right side of the body. Soon afterwards, the Parkinson's symptoms began to improve in his right side. His trembling decreased, until to all appearances it disappeared. Neurological evaluation indicated a marked improvement in his symptoms, which lasted for about 5 years. Because Parkinson's is a progressive ailment, his condition is continuing to deteriorate, but as Mr. Turner recently testified at a U.S. Senate Committee hearing, "…I have no doubt that because of this treatment I've enjoyed five years of quality life that I feared had passed me by." He enthusiastically expressed a willingness to undergo a repeat surgery of this sort to further slow the progression of his symptoms