Posted on 06/28/2007 6:47:21 PM PDT by neverdem
Associated Press
Embryonic Stem Cells Created From Unfertilized Eggs, Not Embryos, Scientists Report
Scientists say they've created embryonic stem cells by stimulating unfertilized eggs, a significant step toward producing transplant tissue that's genetically matched to women.
The advance suggests that someday, a woman who wants a transplant to treat a condition like diabetes or a spinal cord injury could provide eggs to a lab, which in turn could create tissue that her body wouldn't reject.
Ethicists disagreed on whether the strategy would avoid the long-standing ethical objections to creating embryonic stem cells by other means.
Such cells can develop into virtually any tissue of the body, and scientists hope to harness them for producing specialized tissues like nerve cells or pancreas cells to treat a range of illnesses. But the process of harvesting the stem cells destroys embryos, which many people oppose.
To create tissues that genetically match a patient, some scientists are trying to develop a process called therapeutic cloning, in which DNA from the patient is inserted into an unfertilized egg, an embryo is produced and stem cells are harvested. But nobody has made that work in humans.
The new work tries another tack: stimulating a woman's unfertilized egg to begin embryonic development. Scientists believe this development can't continue long enough to produce a baby, but as the new work shows, it can produce stem cells that are genetically matched to the egg donor.
Such an approach could not provide matched cells for men, of course.
The work, published online by the journal Cloning and Stem Cells, is reported by scientists from Lifeline Cell Technology of Walkersville, Md., and from Moscow.
Jeffrey Janus, president of Lifeline and an author of the study, noted that stem cells produced by the method might prove useful for patients other than the egg donor, in combination with anti-rejection therapy. That's the case with standard stem cell lines created from ordinary embryos, he said.
He and colleagues report producing six lines of embryonic stem cells, one of which had chromosome abnormalities. They obtained their eggs from five women who were having eggs harvested for test-tube fertilization, and who agreed to donate some for the research.
"It's a big deal, it's a very nice advance," said Kent Vrana of Pennsylvania State University, who has done similar work in monkeys. The process appears efficient, he said, and it provides "an additional tool" beyond therapeutic cloning.
George Daley, a scientist at the Harvard Stem Cell Institute, called the work interesting.
"It's a new type of embryonic stem cell line from a different kind of embryo," he said. "We just don't know whether these cells will be as good as embryonic stem cells from naturally fertilized embryos."
One question, he said, is whether the lack of a father's DNA contribution would impair the performance of the stem cells. DNA in sperm carries particular markers that differ from those found on DNA in an egg, and these markers affect the activity of specific genes.
Ronald M. Green, a Dartmouth College ethicist, said he believes the egg-stimulation process will prove an ethically acceptable way to create stem cells.
"People will see that these are activated eggs ... they do not of themselves ever develop into a human being," he said. "This is not anything biologically or morally like a human embryo, and it's a very good way of trying to provide human embryonic stem cells that does not involve the destruction of an embryo."
But the Rev. Tad Pacholczyk of the National Catholic Bioethics Center in Philadelphia disagreed.
"My view is that if these grow as organized embryos for the first few days and then arrest, they may just be very short-lived human beings," he said.
"One is very possibly dealing with a defective human being. And at a minimum, the benefit of the doubt should be given here, and these embryos should not be created for the purposes of destroying them."
On the Net:
Cloning and Stem Cells: http://www.liebertpub.com/clo
Yes, it does make a difference, centrosome or centromere. But, even the idea that the centrosome is provided by the sperm is controversial. Human oocytes have centrioles, just like every other cell, and not everybody agrees that they are there just "for the looks". If I have time, I'll dig out some references later on. But for now, somebody else in this thread put it really good: if you are creating a handicapped embryo, that still does not give you the right to destroy it (or make sure it self-destroys).
You and I can disagree on whether this process is cloning (it's just a matter of semantics) and on whether or not the embryo formed is a human being (if it wasn't human, there would be no interest in using it to "treat" human diseases), but you have to agree with one thing: in case of doubt you ought to give it the benefit of the doubt, maybe it is a human embryo, maybe it has the inalienable right to life (given to him by his Creator, not by a researcher). So you are most likely killing a human being, for what? Nothing! That's the sad part of this discussion. Like I said before, there hasn't been a single cure using embryonic stem cells, while adult stem cells are already helping people. So, I have to wonder why the obsession with using embryos, what is your real agenda.
Unfortunately, the ANT depends far too much on who is contemplating carrying it out. Dr. Hurlbut (and, I believe President Bush, since I know his advisors are Dr. Hurlbut, Dr. Prentice, Dr. Cameron and Mr. Doerflinger) would do the animal research first.
In contrast, far too many (whose main agenda is to justify destruction of the human embryo) would jump to using human DNA.
It’s amazing to me that we keep hearing what a crisis the Bush policy has created, and yet we read this report, ACT’s several experiments to prove that hESCs can be made without harming embryos, etc. Doesn’t look like there’s a great shortage of embryos, oocytes, or money to me!
To say that a human embryo is flushed away once a month is therefore misleading. The egg is not an embryo, it cannot divide and develop. That's what is "flushed" once a month!
On the other hand, the embryo, formed by fertilization, is a diploid cell (46 chromosomes), it is the earliest form of life, and if let alone it will start dividing, the cells specialize, and given the time becomes a baby.
Can you tell if a cluster of cells is an embryo, with an inalienable right to life, or just that, a cluster of cells? Sure thing! Do a karyotype, where you can actually see the chromosomes. If the cells have one copy of each chromosome, this is a haploid cell, it is NOT a human being, and as such does not have the rights to which human beings are entitled. But if there are 2 copies of each chromosome, this diploid cell IS a brand new, unique, human being and nobody has the right to take his/her life. What these people are doing is taking an unfertilized egg (haploid), removing the nucleus and replacing it with the nucleus of a somatic cell (diploid). Once they have a diploid cell, it can be activated to begin cell division and an embryo is formed. This is a unique human being, both genetically and spiritually, and this is what I oppose killing.
As for harvesting embryonic stem cells to save your life... don't hold your breath! So far there has not been a single report of treating a condition with embryonic stem cells. On the other hand, there are dozens of treatments with ADULT stem cells, ranging from experimental, to clinical trials, to standard treatments like bone marrow transplant. So, if I was concerned about saving my life, I would go with the research that shows results, not with the one that promises but does not deliver!
Nice post. I think some scientists are playing semantics and are, as usual, not very good at it without a hammer in their hand (to beat a slogan to death).
What the article and you are describing sounds like human cloning, no? How is this even allowed by law?
Oh, and just to add to your great description of the process of human generation: actually a couple dozen unfertilized eggs are lost in each menstrual period. Only one (or two) may have actually ripened, but there are usually between 10 and 30 unripened follicles that are destroyed with each cycle.
Earlier this month the House rejected the "clone-and-kill measure", and pres. Bush has vetoed the stem cell research bill because it would have allowed for the cloning on human embryos. A showdown is about to take place in the Senate, where they will try to override pres. Bush's veto. If you care about this issues, please contact your senator and ask him/her to oppose S5.
Anybody who wants to learn more about the "legalities" of human cloning, go to National Right to Life Committee
Thanks! I wish my students were so appreciative of my efforts! :-)
“fertilization” is joining 2 unique halves of dna in an egg.
Here, we are talking about removing the original 23 in the egg, and adding a full set of 46 already found in the mother. In other words, HER CLONE.
Please answer why I should not be able to get what I may need to live by “harvesting” my embryonic clone? Or do you hold that my clone has a unique spirit as well?
The level of development of my clone would govern whether or not I had any qualms about harvesting him. If he is embryonic and I can make multiple copies of him, I harvest away as needed. If he is my twin by natural childbirth, I couldn’t possibly do the same thing, for all the obvious reasons.
I do believe that the parthenogenetic human embryo is a human being and we agree on the ethics of destructive embryonic research.
Take a look at my posts, especially number 6 and 13, again. (I said, “However, if it looks like an embryo and makes cells that act like embryonic cells, it’s an embryo.” And, “The only benefit to this research is publicity value and the doubt that is created by noting how un-natural the process is. This is not the time to create new ethics - old ethics works. If you’re not sure whether or not there’s an embryo, don’t do it, if you are sure, certainly don’t do it.”)
Those are pretty good references that I posted on the contribution of the sperm to the embryo. (I use the NCBI website, http://www.ncbi.nlm.nih.gov/ )
From that first abstract, http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=16467269&dopt=Abstract
“The proximal centrosome adjacent to the sperm nucleus may become the center of the sperm aster that brings the male and female pronuclei to the center of the zygote, but it may not be essential for embryonic development per se.”
The article is not describing cloning or SCNT: there’s nothing inserted in the oocyte (I hate the term, “unfertilized egg.” It’s redundant - after fertilization, there’s no egg!
From O’Rahilly (Human Embryology and Teratology, Third Ed., 2001, p.34)on parthenogenesis:
“Parthenogenesis is the production of an embryo, with or without later development into an adult, from either a female or male gamete in the absence of any contribution from the gamete of the opposite sex. . . It is believed that parthenogenetic activation and development may be relatively common in the human. However, the probability of abortion of a parthenogenetic embryo is very high because of poor development of the extra-embryonic tissues, for which the male genome is mainly responsible.”
Please re-read the article or the original report. http://www.liebertonline.com/doi/pdfplus/10.1089/clo.2007.0033
There is no “cloning.” The chromosomes in the haploid oocyte are induced to copy themselves and the new embryos are nurtured through the early stages of development, until there is a blastocyst, with a trophoblast and an inner cell mass.
However, I am interested in your “obvious reasons” for not destroying your “natural twin.” Please explain.
Because of what "harvesting" really means...KILLING! What you are asking is "why shouldn't I make a human being and kill it for my benefit?"
do you hold that my clone has a unique spirit as well?
Do identical twins have unique spirits each? I believe they do, so even though I don't know it for a fact, I believe that a clone has a unique spirit also. Or do you think that we are so advanced that we can "outsmart" God and produce human beings without a spirit?
On a more personal basis, you seem fixated on "getting what you need to live". It makes me wonder if you, or a loved one, has some chronical condition that you are hoping will be cured with embryonic stem cells. If that is the case, Freep-mail me and I will be more than happy to discuss with you issues that you may not want to post for everybody to see. Remember, God loves you (John 3:16) and will be there for you.
How comes? What makes an embryo less human than a newborn? From a purely biological point of view, life is a continuum. We use terms such as zygote, embryo, fetus, newborn, child, teenager, adult... merely to indicate the level of development, to make communication simpler. But there's nothing in the zygote that makes it any less human than an adult astrophysicist! From a religious point of view, we are known and called by God from the womb (Isa 44:2, 24) and we are commanded to save lives (Prov. 24:11-12).
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