Interesting article, Henry. But as they say, it is a synthetic compound and there is no evidence that Premarin will react in the same way--BUT I bet they are already checking it out. Certainly could push the development of SERMs.
Anyway here is a very interesting article from the NY Times, somewhat off topic but highly relevant to biotechnology. In any case most of the recent posts have been pretty far off topic. The most important implications are the tremendous advances scientists are making in the success rate of cloning attempts, with some approaching 50%. Brave New World, here we come!!!
BOSTON -- First Dolly, the sheep, now Charlie and George, the calves: two long-lashed, week-old, genetically engineered Holsteins became the latest cloning sensations Tuesday when scientists announced they had been given life using an efficient new method that offers the hope of broad and lucrative medical benefits.
The calves were cloned from the cells of cow fetuses by two University of Massachusetts scientists, Dr. James Robl and Dr. Steven Stice, who also work for Advanced Cell Technology Inc., a biotech start-up in Worcester, Mass.
The calves' creation, which cloning experts say essentially repeated work done with sheep but simplified it and extended it to a more useful species, was presented in Boston on Tuesday at a conference of the International Embryo Transfer Society.
"I look at this as being a major step toward the commercialization of the technology," Robl said. "It takes something that is theoretical, something that has been demonstrated once, and says OK, we can do this now on a broad level, and we can do it efficiently."
Cloning specialists say George and Charlie could help lead the way toward "pharming," creating genetically altered animals that act as living drug factories by producing valuable pharmaceutical substances in their milk, or as living organ factories because their organs will no longer be rejected by the human immune system.
They also commented that the calves' birth in Texas, coming less than a year after scientists in Scotland stunned the world by announcing the birth of Dolly from the frozen udder cell of an adult sheep, showed how quickly cloning technology is advancing.
"What you get is a whole series of experiments that says cloning is a real process and that it's bound to get more effective," said Dr. Neal First, a cloning expert at the University of Wisconsin.
It was also not lost on the calves' scientific parents that their timing turned out well in that the calves' births last week came just days after the hullabaloo raised by a Chicago physicist's announcement that he planned to undertake human cloning for infertile couples as soon as possible. Most scientists have expressed doubt that the physicist, Dr. Richard Seed, will be able to make good on his promise.
"This brings back to reality what this technology is really being used for," said Tracey Stice, Stice's wife and a public relations consultant to Advanced Cell Technology. "It grounds this technology."
Advanced Cell Technology, which is a wholly owned subsidiary of Avian Farms, a Maine poultry genetics company, is also working on cloning pigs, Stice said. In addition, he said, it hopes to use cloned, genetically engineered cows as donors for neural cells that could be used to treat nerve-damaging diseases like Parkinson's and diabetes.
More immediately, it already has a contract with Genzyme Transgenics Corp. to make a herd of genetically engineered cattle that will produce human serum albumin, a protein that is currently derived from pooled human plasma and is given to people who have suffered blood loss.
George and Charlie -- and a third new calf yet to be named -- appeared to be the talk of the society's conference Tuesday, and members buttonholed at a coffee break Tuesday afternoon uniformly said they found the advance exciting.
"It's a major accomplishment, putting several different technologies together," said Duane C. Kraemer, a reproductive physiologist from Texas A&M.
"They've leaped over the Roslin stuff," said his colleague from the University of Saskatchewan, Reuben J. Mapletoft, referring to the lab in Roslin, Scotland, that created Dolly.
Stice and Robl also reported that two of their cows are well into pregnancies carrying fetuses that are cloned from adults.
Dolly, who was cloned by Dr. Ian Wilmut of the Roslin Institute in Scotland and Dr. Keith Campbell of PPL Therapeutics there, was the first animal that was the clone of an adult.
Last summer, the Roslin scientists announced that they had created three lambs, one of which they named Polly, by adding a human gene to fetal sheep cells and then using the cells to produce clones of the fetuses. The gene directs cells to produce a human protein that is used to treat hemophilia. The cloned lambs had the human gene in every cell of their body. When these cloned ewes produce milk, the drug should be present and could be extracted from the milk.
Also last summer, another company, ABS Global Inc. of De Forest, Wis., announced that it had a better way to clone and that it had a number of pregnancies under way that should result in calves that are clones of adult cows.
With Tuesday's announcement by Robl and Stice, there are now a total of three methods of cloning and reports of cloning success in two species, sheep and cows.
To clone, scientists essentially have to bring a cell's genetic material backward in time, erasing the modifications to genes that enable a cell to be one specialized type, like an udder cell, and turning it into the state it was in when sperm first fertilized egg. Then the newly reprogrammed genetic material can orchestrate the development of a new animal that is the genetic identical twin of the one that provided the original cell.
The question, however, has been how to reprogram the genetic material of a fully developed cell. Until last year, many scientists would have said that it could not be done. But, with the announcement of the creation of Dolly, it suddenly appeared possible.
Wilmut and Campbell showed that even though scientists have no idea how to reprogram genetic material, an unfertilized egg can do the job. They put a cell into a state of suspended animation, slip it into an unfertilized egg, activate the egg with a jolt of electricity, and create an embryo.
But the process is not very efficient. When they made Dolly, the investigators added udder cells to 277 eggs. Only 13 developed into embryos. All but one of the embryos died early in pregnancy. The remaining embryo survived to become Dolly.
Robl and Stice say that their method was designed to give the egg more time to do its reprogramming. So they added cells that were dividing normally to unfertilized cow eggs whose own genetic material had been removed. Then they waited about 6 hours for the egg to do its work before activating the eggs and starting the process of embryo development.
With this method, Stice said, 5 percent to 10 percent of the group's attempts to create embryos from adult cells have been successful.
It is even easier to clone from fetal cells, Stice added. When he and Robl used skin cells from fetuses that were one to three months old -- old enough to be fully formed, with beating hearts -- about 10 percent to 20 percent of the cells became embryos. The investigators froze the embryos and shipped them to Texas to be implanted into cows. About 40 percent survived in their surrogate mothers, Stice said.
At ABS, said Dr. Michael Bishop, director of research and technology there, investigators also decided to give eggs more time to reprogram the genetic material of cells for cloning.
But they had a different method. They added a cell to an unfertilized egg whose own genetic material had been removed, and then they activated the egg. Once it had divided a few times, they took the early embryo cells and added each of them to another unfertilized egg, giving the cells a second chance at having their genetic material reprogrammed.
Bishop said that about 50 percent of his attempts to clone resulted in pregnancies and that it is as easy for him to clone from adult cells as it is with fetal cells. Like Robl and Stice, he is awaiting the births of the first cows cloned from adults.
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