Posts Tagged ‘fetal stem cells’

What You Should Know About The Stem Cell Research Controversy

Saturday, July 18th, 2009

stem cell controversy

One of the first things President Barack Obama did upon taking office was lift the controversial ban on stem cell research. The National Institute of Health informs us that human stem cells are very important to scientific research because they have the potential to differentiate into almost any type of cell, tissue or organ in the body. Additionally, stem cell therapies may make it possible for humans to regenerate damaged parts of their own bodies more naturally, without using artificial materials or drugs. In the future, scientists hope to treat cancer, Parkinson’s, heart disease and diabetes with stem cells.

In an embryo that is just three days old, stem cells are found that will later transform into the heart, lungs, skin, tissues, bone marrow, muscle and brain. Advocates of stem cell research believe that there may be a way to generate replacement cells for parts of the body lost through injury, disease or aging. What makes stemcells different than blood, muscle or nerve cells is their innate ability to replicate for months in a laboratory setting. Scientists are hopeful about the potential for long term rejuvenation using these self-renewing human stem cells.

There are two varieties used in modern stem cell research: stem cells embryonic and stem cells adult. Embryonic stem cells are cultivated in a Petri dish from in vitro fertilization. This type of stem cell is extremely versatile and can differentiate into more than 220 cell types in the body for more than a year in a research setting, which is promising for many future medical treatments. Scientists are still trying to understand why embryonic cells are so much more flexible than adult stem cells. Some Americans feel it is inherently wrong to tamper with human cells, by creating, manipulating and destroying fertilized cells that could otherwise continue to grow into human life within a host.

While stem cell research has been full of controversy in America, other nations, notably Iran, have nothing against stem cell research at all. “Policies that may be classified as liberal in the American political system seem to be common sense to Iranian politicians,” explains Hassan Ashktorab of the Howard University Cancer Center in Washington, DC. While George W. Bush banned research on fetal stem cells, Iran’s Ayatollah Khamenei embraced the modern science. While human cloning is still condemned in Iranian culture, they believe it is their duty to do their best to prevent illness and protect human life.

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Taking A Look At Embryonic Stem Cell Research

Friday, July 17th, 2009

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Is the debate over embryonic stem cell research finally over? Now that scientists in the US and Japan have found more effective ways of harvesting adult stem cells from the umbilical cord, there may be no need to obtain fetal stem cells that destroy an embryo in the process. Even so, the pondering of the stem cell controversy begs some interesting questions. Is it worth destroying a life to save a life? When does life even begin? What are stem cells exactly?

When does human life begin? This is the quintessential theological question behind embryonic stem cell research. Devout Catholics and Protestants will tell you, “Human life begins at conception, at the very moment when sperm and egg come together. Development from there on out should be left up to God and God only.” They argue the problem is that embryos are killed in the process of harvesting stem cells, therefore aborting the developing embryo. In a speech on August 9, 2001, former President George W. Bush explained, “While we must devote enormous energy to conquering disease, it is equally important that we pay attention to the moral concerns raised by the new frontier of human embryo stem cell research. Even the most noble ends do not justify any means.” Pope Benedict XVI went so far as to say human stem cell research was “not only devoid of the light of God but also devoid of humanity.”

Scientists working with fetal stem cells argue they’re using primitive “blastocyte” cells fertilized in Petri dishes that are typically 3-5 days old and have not formed nerves or brain cells yet. The general consensus is that fetuses are not capable of feeling and processing pain until the third trimester, or 28 weeks, when the thalamocortical connections are developed. To others, it’s a matter of practicality. James Thomson, the first scientist to do embryonic stem cell research, told MSNBC’s Alan Boyle in June 2005, “The bottom line is that there are 400,000 frozen embryos in the United States, and a large percentage of those are going to be thrown out. Regardless of what you think the moral status of those embryos is, it makes sense to me that it’s a better moral decision to use them to help people than just to throw them out. It’s a very complex issue, but to me it boils down to that one thing.”

Embryonic stem cell research still has many hurdles to overcome before expensive, widespread human testing is funded. Scientists are still trying to understand what conditions cause a stem cell to differentiate into a particular tissue or organ, for instance. They’re also not sure what causes the proliferation and what stops the proliferation (to prevent uncontrolled cancerous growth). Stem cells research carries much promise but it will take a lot of funding and patience.

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Pointers About Embryonic Stem Cells

Tuesday, July 14th, 2009

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What if human cells could be stimulated to regenerate body parts or repair damaged tissues in the same way that earthworms or planarians can? Embryonic stem cells are the most versatile type of cells to work with because they can differentiate into any kind of cell in the body. Adult stem cells are more tissue-specific, although the body responds better to its own stem cells in therapy. In order for stem cell therapies to work, the body’s immune system must be suppressed so there is no reaction to the transplanted cells. Additionally, scientists must take special care to ensure the cells proliferate enough to heal the body but not so much that cancer develops.

There are two types of stem cells research. One involves the use of embryonic stem cells and the other involves the use of adult stem cells. The embryonic cells come from a one-week-old mass of cells called a blastocyte. Many of the fetal stem cells come from in vitro fertilization patients who had leftovers after receiving fertility treatment. A single embryo can create enough lines of cells for use in Stem cell therapies. Tissue from aborted fetuses is not regularly used in stem cell research. What makes an embryonic stem cell so special is that it can develop into any organ or tissue. Stem cell therapies can help treat diseases like heart or Parkinson’s disease, as well as burn or stroke victims and patients with spinal cord injuries, muscular dystrophy, arthritis and diabetes.

Though fetal stem cells have been the focus of most of the research, scientists are discovering that adult stem cells are particularly effective in transplants. For instance, they can grow an entire organ, a section of the windpipe or a section of tissue to offer the human host, which will most certainly accept the new cells derived from its own DNA. Another alternative to using embryonic stem cells is under current examination. It involves stimulating adult stem cells to revert back to their “pluripotent” state, which allows them to proliferate again. It’s believed that humans may be able to regrow lost skin or repair other tissues this way, although more research is needed before human trials can begin to prove this theory.

In recent stem cell news, the Harvard Stem Cell Institute (HSCI) and Massachusetts General Hospital discovered that a medication for bone marrow cancer can affect osteoporosis in mice by acting upon mesenchymal stem cells, which differentiate into several tissue types. “Stem cell therapies are often thought of as putting new cells into the body,” said David Scadden, director of the MGH Center for Regenerative Medicine, “but this study suggests that medications can turn on existing stem cells that reside in the body’s tissues, acting as regenerative medicines to enhance the body’s own repair mechanisms.” Therefore, instead of relying on controversial embryonic stem cells, a person’s own stem cells can be used in the treatment.

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An Overview Of The Human Embryonic Stem Cells

Saturday, July 11th, 2009

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Human embryonic stem cells are a relatively new field of research. The first human stem cell was isolated for experiments by Dr. James Thomson from the University of Wisconsin in 1998. A ban on federal funding for research involving fetal stem cells further stymied research possibilities for many years until former President Bush allowed some of the frozen stem cell lines to be used for research, rather than discarded. Then President Obama lifted the federal ban entirely. As a result, human stem cell research is still in its early stages, but human clinical trials are expected to begin this summer.

There are three classes of human embryonic stem cells. A fertilized egg is “totipotent,” which means that it can give rise to any type of cell in the body. A “pluripotent” stem cell can become any type of cell in the body (except for those required to develop a fetus). “Multipotent” cells can give rise to a small number of other cell types. These fetal stem cells are usually taken from embryos and used to create “stem cell lines,” which can be grown forever in a laboratory setting. While most stem cells come from young embryos that are just 3 to 5 days old, some pluripotent stem cell lines may be derived from fetal tissue that is beyond 8 weeks old.

There are several traits that make human embryonic stem cells preferable for stem cell therapies. For one, these early developmental cells are a blank canvas. These cells have no particular tendency to become anything specific but may be encouraged to become one of 200+ cell types. Additionally, fetal stem cells can remain in this protean, undifferentiated state for long periods of time and may divide or self-renew indefinitely. Therefore, it’s easier to create mass quantities of embryonic stem cells for use in adult stem cell research.

Even though research using human embryonic stem cells was limited to select states that passed ballot initiatives, underground, privately-funded scientists have been working diligently since 1998 to find ways to use not just fetal stem cells but also adult human stem cells. It was previously believed that embryonic stem cells were versatile, able to become any of 200+ cell types and that adult stem cells were confined to only replicating more specialized cells of a similar nature. In late 2007, scientists found a way to reprogram adult stem cells to behave like embryonic stem cells that will form a number of other tissues, rather than just the tissue it was derived from. More studies are needed to determine whether these manipulated cells are safe for use in humans, but the findings are significant.

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An Overview Of Adult Stem Cell

Wednesday, July 1st, 2009

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The adult stem cell has been collected to treat leukemia, lymphoma and inherited blood disorders. Most recently, it’s believed stem cell therapies will benefit patients with diabetes and kidney cancer. While widespread human treatment using stem cells is still nearly a decade away, scientists are rigorously studying these cells for answers to some of life’s greatest mysteries: How do unspecified cells find their purpose? How do they know when to begin replicating and when to stop? Can we manipulate these cells inside the body or use transplanted cells outside the body to produce treatments? Will the body accept or reject these cells?

To be considered an embryonic stem cell, a young cell must be located in the inner mass of the blastocyst. By contrast, the adult stem cell is not characterized by its origin. To be considered stem cells adult variety, the cell must have the ability to differentiate and must be able to self-renew for the lifetime of its host. Scientists are always discovering new locations of adult stem cells, which have grown from the spinal cord and the bone marrow to include the brain, the blood vessels, the hair follicle, skeletal muscle, fat, the skin’s epithelia, the digestive system, the cornea, the retina, the peripheral blood, the teeth, the liver and the pancreas.

One of the most exciting adult stem cell discoveries occurred in 2008 when researchers at the Salk Institute for Biological Studies in La Jolla, California coaxed mouse brain stemcells to differentiate into support cells and function with the surrounding neuronal network. When pampered in a Petri dish, scientists found that they could encourage oligodendrocyte cells to form the fatty myelin sheath that speeds up the transfer of electrical signals along the axons. They could also stimulate cellular growth in the hippocampus; the brain’s center for memories and learning. Scientists hope this research can provide a breakthrough in the treatment of multiple sclerosis, Alzheimer’s, stroke and epilepsy.

The most studied type of adult stem cell is called a “hematopoietic stem cell,” which is derived from bone marrow. Using transplants, scientists have restored immune and blood components using stem cells. Scientists have identified stem cells in the hippocampus region of the brain whose function is currently unknown and are looking at ways to induce proliferation or differentiation in these seemingly dormant cells. Muscle, blood and fat stem cells may be able to transform into other cell types under certain conditions, which will fuel many studies in the years to come.

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