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Home Tag: "History"

Tag: History

21Jan

Stem cell therapy is a recent arrival in the world of medical science and treatment. It’s a very promising form of treatment; however it is also very limited in its application, with very few authorized treatments available to the public, at least in the United States. Leukemia, a form of blood cancer, is one of the few treatments in the USA that the Food & Drug Administration has allowed hospitals to offer to patients.

For some, this is an incredibly frustrating decision, as the promise of stem cell therapy shows massive potential in other areas. Stem cell therapy is widely regarded as a viable treatment for many conditions that would be considered otherwise untreatable, such as Alzheimer’s, Parkinson’s disease, arthritis, and even complex conditions like Autism Spectrum Disorder, or ASD.

There may come a day in the future when stem cell therapy is more widely practiced for a variety of different ailments. For now, however, research is largely ongoing. But what is stem cell therapy? Why is it so new, and why is its application so limited? To better understand the situation, let’s take a look first at the nature of the stem cell.

The Blank Slate

For decades the stem cell was a medical concept, but it was unproven. However, medical science knew that something like the stem cell had to exist because otherwise, human reproduction was impossible. In a typical human body, the most that cells can do is reproduce more copies of the same cell. Skin cells, for example, grow new skin cells to replace skin damaged by cuts or bruises. When we get a haircut, hair cells reproduce more hair cells to replace the lost hair. A skin cell can’t grow a brain cell, and some cells, like heart cells, can’t reproduce at all, meaning any damage to a heart is permanent.

However, during pregnancy, this state can’t exist. There are no skin, bones, lungs or blood for normal human cells to come from because a baby isn’t fully formed yet. A baby grows from an egg fertilized by a sperm, and somehow creates cells that eventually specialize into the organs required. That “somehow” is the stem cell, but medical science was unable to locate it.

The Breakthrough

In 1981, researchers finally isolated stem cells in mouse experiments. Martin Evans, researching at Cambridge University in the United Kingdom, became the first scientist to identify embryonic stem cells in his chosen research subject, mice. Evans then took things a step further and isolated the stem cells, modifying them, and then transplanting them into female mice.

The experiment was a success, and the first genetically modified stem cells were carried to term in female mice, resulting in offspring that had been artificially manipulated through science. Now, not only were stem cells identified, they could be used and even altered, at least in rodents.

The Human Equation

It took many more years, but in 1998, the same feat of identifying, isolating, modifying, and growing a new, specifically cultured human stem cell was accomplished. In two different research labs, James Thomson at the University of Wisconsin and John Gearhart of Johns Hopkins University in Baltimore both managed to isolate and grow stem cells.

At this point, however, stem cells, as more awareness of them grew, created some public controversy. While the goal had been to create stem cells through laboratory means, the initial research done utilized embryonic cells no longer required for IVF, or in vitro fertilization, and the extraction of such cells destroyed the embryo.

The Barriers Drop

In 2001, the President of the United States at that time, George W. Bush, put limits on stem cell research due to ethical and religious concerns. Stem cells that had already been cultured and grown from previous experiments were allowed to continue, but no new sources of stem cells for cultivation could be acquired.

This was a setback for researchers since this significantly limited the supply of available material to make research more widespread. The result was that research slowed down.

More Discoveries

However, the promise of stem cell research and therapy could not be denied. Even with the limitations, existing research made great strides forward that excited the medical science community. Stem cells were successfully reprogrammed in 2007, and in 2009, President Barack Obama lifted research restrictions. In 2010 research was conducted into treating spinal injuries with stem cells, and in 2012, blindness treatment research began.

The Current State

While the USA has stem cell treatment largely for research with only leukemia being an available public treatment, other countries, such as Georgia, offer stem cell therapy. This type of stem cell therapy, however, requires an existing, biologically compatible supply of stem cells to treat patients with. The source in this treatment method is either stem cells harvested from a mother’s womb after a child is born, or, if unavailable, stem cells from a close genetic relative, such as a sibling born of the same mother at a later date. It’s also possible to harvest stem cells from bone marrow, but these are not pluripotent, like embryonic cells, and therefore less versatile.

26Aug

One of the “Holy Grails” of medical science is the idea of regenerative healing. If such a technique were discovered and perfected, it could, in theory, solve many of the medical issues that we have today. As a simple example, nature has already shown us that even the loss of a limb can be recovered from through regenerative healing. When a lizard is threatened and grabbed by its tail, for example, the lizard can pull itself free, tearing its own tail off.

However, that’s not the end of the story. The lizard is then able to grow back a new tail in time as if nothing ever happened. Humans, however, don’t have this type of healing capacity. If a limb is damaged beyond repair, or compromised by disease, such as an arm, or a leg, and is amputated to save the rest of the body, it doesn’t grow back. If an organ is seriously injured or compromised by illness, such as a heart, or a lung, there’s no way to get naturally regrow one, and only a transplant from a compatible donor can save that patient. If there is no compatible donor, then the transplanted organ is rejected by the body.

Now, however, medical science is taking the first steps towards achieving that dream of regenerative healing. It’s called stem cell therapy, and while it’s already proven its worth in some very specific areas of medical treatment, the technique has promise for much more.

How Does It Work?

The secret to stem cell therapy is the cell itself. Stem cells have a unique property, one that is necessary to take a fertilized egg in a mother’s womb from a single cell to a fully developed human baby with different organs. The power of stem cells is that they are “blank,” which means they have the potential to become any cell that is required. This ability to shift or “reprogram” into whatever is required is thought of as a form of “potency,” and stem cells in the womb, being the potent of all, are referred to as “pluripotent.”

By introducing stem cells into areas where disease or other types of damage have occurred, the stem cells can replace the damaged cells—even ones that normally don’t reproduce in great numbers, or at all—and turn into the cells required, healing the patient.

It All Starts With Mice

As is quite common in medical science, the potential for stem cell usage was first discovered in experimentation with lab animals. It was in laboratory mice that scientists first recognized the ability of some cells to do more than just reproduce an exact copy of themselves. The property was first discovered in the 1960s with the blood of lab mice when scientists came across “low level” stem cells in the blood, referred to as hematopoietic stem cells.

These cells were eventually regarded as “multipotent.” They could reproduce themselves and, if required, they could reproduce into the many variants of blood cells that are used in the body, but they could not turn into other non-blood related cells, such as brain or skin cells.

It was from here that scientists eventually learned more about stem cells, and discovered not only the pluripotent stem cells in mice but how to manipulate them. This made huge strides in research, as now mice could be bred with the desired genetic characteristics for experimentation, and, over the decades, medical science worked to see if this type of stem cell usage could one day be applied to humans.

The Cancer Breakthrough

In the 1980s, stem cell research had advanced sufficiently that it was felt safe enough to try on humans, with incredibly promising results. Cancer is one of the most difficult diseases to treat, because there are so many variations of it, for almost every part of the body. Cancer itself is a wide-ranging disease, with the chief cause being that, for various reasons, an organ begins to reproduce flawed/incorrect copies of itself, and these flawed cells eventually overpopulate and outnumber the healthy cells they are replacing. Eventually, this can lead to death.

Scientists used stem cell therapy to treat leukemia, a cancer threat to the blood, bone marrow, and lymphatic system. They introduced compatible stem cells into leukemia patients and found that stem cell therapy was an effective means of combating this type of cancer, and even curing it.

The Exploration Continues

In the decades since, stem cell therapy has continued to be experimented with in other areas. Embryonic stem cells, the pluripotent ones, are still the most valued, and new mothers, upon giving birth, have the option to harvest the umbilical cord blood after the birth, that is rich in stem cells and preserve for possible future use.

Now stem cell therapy usage is being explored for a variety of conditions, from multiple sclerosis to Alzheimer’s disease, to ALS and autism. With the proper application, the potential for stem cell therapy is incredibly promising.




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