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Originally Posted by Kuuipo
Hybrid experimentation recalls the hybrid experiments of NAzi Germany.
There are film footage and books. I was able to see some of the horrific notes a long time back. They were trying to mate healthy young Jewish female prisoners with various animals to see what would happen.
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The Nazi hybrid 'experiments' have absolutely no bearing whatsoever on the techniques, methodology and ethics of the use of hybrid embryos for scientific research. To use Nazi atrocities as a comparison to the hybrid embryos in question is unfair.
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Originally Posted by Kuuipo
We have used animal parts in humans the last two decades in this country and overseas. We have porcine (pig) valves for the heart, many in mitral or tricuscid valves for the prevention of regurgitation of blood that can clot and cause strokes or myocardial infarctions (heart attacks). We use pig parts to make insulin and heparin and we use cow products (bovine) for vascular (blood vessel) grafts. (These do not work as well as human or Gortex grafts-generally).
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My brother had a pulmonary pig valve that saved his life. He was born with a conginental absence of the pulmonary valve in 1980. He was part of a pilot study of 25 patients at Mayo Clinic that received porcine valves to replace the missing valve. For his second surgery, in 1991, he received a human graft (from a cadaver, if I remember correctly). It wasn't until his third surgery, in 2000, that he received a Gortex graft, iirc. It's supposed to last at least 25 years, assuming the graft is not rejected by his body or that he doesn't have some other complication.
My point is, science changes through time. If they hadn't given him the pig valve in 1984, he wouldn't have been around in 1991 to get the human valve. If I have to choose between a pig and my brother, the pig's going down every time. Animals aren't as important as people.
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Originally Posted by Kuuipo
As far as Parkinson's goes, stem cell research is not the shining light of the future people claim. There have been sucessful surgeries of brain "pacemakers" alleviating much of the symptoms of Parkinsons. Parkinsons occurs when much of the brain's Substantia Nigra deteriorates. The SN is not replaceable.
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I think that's up for debate, and I disagree with you on a number of points based on the research I've read.
First, the massive amount of funding and scientific research being produced on a daily basis seems to indicate there are many in the scientific and funding-body community who believe this research is well worth the effort. As someone trying to get funding for research, believe me when I say that you simply cannot get funding unless your research shows the promise of results and you have a well-proven track record of results. It's tempting to believe people are just tossing money at scientists willy nilly, but this is not true. There is a very small amount of funding available, and it is extremely difficult to get it. The work has to be justified, academically, ethically and financially.
Secondly, you mention two different treatments, a "pacemaker" versus replacement therapy. One type of treatment may be more appropriate for a patient than another. The "pacemaker" device does not always work.
Lastly, the replacement treatment from stem cell research for Parkinson's in particular is not an attempt to replace the SN. It is an attempt to replace dopaminergic (DA) neurons in the SN. Perhaps later the research will attempt to replace the SN entirely, but that is not the aim at the moment.
In defense of stem cell research, I've given excerpts below from a recent press release article dated January 2008, from the European Science Foundation (here:
Stem cell research aims to tackle Parkinsonâ€s disease: European Science Foundation)
Professor Ernest Arenas of the Karolinska Institute in Stockholm presented his research to the EuroSTELLS “Stem Cell Niches” conference in Barcelona on January 11. Stem cell therapy hold the promise of treating disease by growing new tissues and organs from stem cells – ‘blank’ cells that have the potential to develop into fully mature or ‘differentiated’ cells. The EuroSTELLS is an ESF EUROCORES programme, managed by the European Medical Research Councils (EMRC), that aims to develop a stem cell ‘toolbox’ by generating fundamental knowledge on stem cell biology.
Parkinson's disease results from the loss of a particular type of brain cell called dopaminergic (DA) neurons in the part of the brain called the substantia nigra.
Among the various approaches that are currently being discussed from an ethical perspective, is the possible approach of taking stem cells, growing them into new brain cells and transplanting these into the patient. "The idea is to start with stem cells and induce them to become neurons," said Professor Arenas, whose research is carried out as part of a EuroSTELLS collaboration. "These could then be transplanted into the brain of the patient. Also, such cells could be ideal for developing and testing new drugs to treat brain disease."
However, to create such cells that function efficiently and safely is a major challenge. Early efforts at growing DA neurons from embryonic stem cells produced cells which, when transplanted into animal models, had a tendency to form tumours or clumps, or die without an obvious reason.
Professor Arenas’s team studied the development of DA neurons in animals to determine the important biological molecules in the brain that were necessary for the cells to grow and function efficiently. The scientists identified one particular molecule that seemed to be key, a protein called Wnt5a. They showed that when this molecule, together with a second protein called noggin, was included in cultures of stem cells, far more DA neurons were produced than when these ingredients were not present.
The team then carried out a series of molecular, chemical and electrophysiological tests on the newly grown neurons to check their proficiency, which was shown to be good.
Crucially the team also moved away from embryonic stem cells – which can be induced to grow into a wide variety of different cells. Instead they used neural stem cells – which are programmed to develop only into nerve cells.
When the researchers transplanted the cells into laboratory animals whose substantia nigra region of the brain was damaged, the results were promising. “We reversed almost completely the behavioural abnormalities, and neurons differentiated, survived and re-innervated the relevant part of the brain better” Professor Arenas said. “Furthermore we do not see the kind of proliferation of the cells that has occurred in the past and we get very little clustering when the cells are treated with Wnt5a. The cells are safer than embryonic stem cells and more efficient than fetal tissue.”
Verification of this approach with human cells is ongoing and if the study is successful, it may lead to a clinical trial. Experts in the field have recently identified this approach as the next step in cell replacement therapy for Parkinson’s disease and the hope is that this may, ultimately, lead to cells suitable for transplant into human patients.
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This leads me to my final comment. Stem cell research doesn't necessarily require embryos. I think this is a major misunderstanding of the research. There are many ways of conducting stem cell research, but a lot of it directly depends on the availability of embryonic stem cells. Some argue that we should use other types of stem cells to make this research ethical. I think scientists should use what works, and have good oversight committees to make sure what those scientists do is ethical and justified.
Neural stem cells can be harvested from [FONT=Verdana, Arial, Helvetica, sans-serif][SIZE=-1]the post-natal, post-mortem, human brain. I'm not sure from the article above, but that's possibly where the Swedish scientists got their stem cells.
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