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The source of this article is the International Herald Tribune: http://tinyurl.com/dadbh Blending of species raises ethical issues By Carolyn Y. Johnson The Boston Globe Thursday, April 21, 2005 Lines blurred between man and beast BOSTON In labs around the world, the line between man and beast is blurring. Herds of pigs are grown with partly human livers in the hopes of solving the organ-transplant shortage. Mice with human cells are used as the new "guinea pigs" for testing drugs or figuring out disease. Human brain cells are grown inside mouse skulls to help better understand diseases like Parkinson's and Alzheimer's. . Scientists are using such chimeras - animals whose bodies are a mosaic, with their own cells intermixed with those of another animal - to model diseases, test drugs on live human cells, and harvest organs for transplant. . But the blending of species also has raised a host of ethical and philosophical questions over the past year. . Last month, the George W. Bush's Council on Bioethics struggled to understand when a human-animal chimera is a useful tool, and when it becomes "high-tech bestiality." The United States turned down a seven-year-old patent application for a chimpanzee-human mix, the "humanzee," in February, with patent officers calling on Congress for guidance. Canada banned the creation of all chimeras last year. And the National Academy of Sciences is set to release ethical guidelines this month for researchers who use stem cells to create chimeras. . "The question is, where does it all end?" said Stuart Newman, a developmental biologist from New York Medical College who proposed the humanzee because he wanted to draw public attention to a morally questionable but technically feasible scientific project that might follow from some of today's experiments. "At some point, everyone will be offended." . Animal rights advocates argue that any manipulation of animals for human benefit, whether for dinner or for research, is immoral. . Christian teaching holds that the Bible gives people dominion over animals. . "That really means stewardship - you cannot abuse them for your good. But just as you would eat a pig or eat a cow, I see no problem in putting a pig valve in a human being or a pig kidney within a human being," said Dr. David Stevens, executive director of the Christian Medical Association, a U.S. group that advocates the practice of medicine from a religious perspective. . The problem arises, Stevens said, when scientists fundamentally alter what it means to be human or animal. "If you give an animal a human brain, if you give an animal human reproductive organs, if you make a human embryo that's not fully human, that crosses the ethical, moral, and biblical line." . The Roman Catholic Church has grave concerns that chimera research may create beings without a clear moral status. "I think it would be basically immoral to create a human whose status we could not determine. We'd have an unresolvable dilemma about how to treat this animal," said Richard Doerflinger, deputy director of the secretariat for pro-life activities at the U.S. Conference of Catholic Bishops. . The scientists doing work on chimeras see their work as ethical and responsible and believe it has tremendous potential benefit. . Charlotte Kuperwasser, a biologist at Tufts University, created a mouse with human breast tissue to solve a longstanding problem in research, that testing drugs by looking at cells in a dish or making a mouse version of the disease doesn't necessarily help actual patients. . Mouse cancers, she said, "'don't look like human tumors. They don't behave like the actual breast cancer. We can cure mouse breast cancers, but that can't always translate to the clinic." . By adding human breast cells to immune-deficient mice before puberty, Kuperwasser has been able to watch normal breast development and generate human cancers rather than mouse ones in her lab animals. Now, she is working to implant particular patients' cancer into mice to see if they can test drugs and cures on it without harming the person. . In Nebraska, William Beschorner is working to create a human immune system and humanized liver in a pig. Eventually the biologist hopes to replicate a particular patient's immune system and then transplant the pig's organs back into the person, where they would appear familiar to the immune system, and therefore wouldn't be rejected. . Even scientists pause, though, when experiments creep from basic organs to the seat of human consciousness - the brain - or when stem cells, controversial in their own right, are added to the mix. . Four years ago, Irving Weissman, a stem-cell biologist at Stanford, created a mouse with human neurons in its brain, hoping that the living model would provide insights into diseases like Parkinson's and Alzheimer's. . The human neurons made up about 1 percent of the mouse brain and were alive, but it was unclear whether they were functioning. He suggested another project: creating a mouse with 100 percent human nerve cells in its brain. . He asked an informal committee to review his proposal, and the group recently drew up guidelines for doing the experiment responsibly. . Hank Greely, head of that committee, described one clear limit. "If you see anything that is not unequivocally mouse behavior, you stop the experiment," he said. . Scientists agree that human brain cells growing in a mouse are unlikely to humanize a mouse because of the vast differences in skull size and brain architecture. But in a closely related animal, the threat of an animal floating somewhere between human and animal becomes more serious. . "What is essentially human is really debased," Alfonso Gomez-Lobo, a member of the Council on Bioethics, said in March. "I often imagine what it would be like to wake up one day only to realize that I have the body of a chimpanzee." . A chimera is an animal with its own cells and that of another animal growing side by side in its body. Scientists used to call such animals "tetraparental," meaning they had four parents - their own, and the parents of the other cells living in their bodies. . The "geep" is an example of a true chimera. Scientists at the University of California at Davis fused together sheep and goat embryos. In the offspring, every organ, including the sex organs, were made up of both goat and sheep cells, which meant that one geep could produce both goat and sheep sperm. . Many other kinds of chimeras are made by adding human cells to animals that have been genetically altered to have no immune system. Without the immune system, which would attack foreign cells, scientists can grow human brain cells or breast cells in another animal, often a mouse. . Chimeras surround us, and not just in the lab. Cardiac surgery patients who receive pig valves to repair their hearts are chimeras. Transplant recipients, who have another person's bone marrow, kidney, or heart thumping in their chest, are a kind of chimera, with the cells of another being living alongside their own. . . See more of the world that matters - click here for home delivery of the International Herald Tribune. . < < Back to Start of Article Lines blurred between man and beast BOSTON In labs around the world, the line between man and beast is blurring. Herds of pigs are grown with partly human livers in the hopes of solving the organ-transplant shortage. Mice with human cells are used as the new "guinea pigs" for testing drugs or figuring out disease. Human brain cells are grown inside mouse skulls to help better understand diseases like Parkinson's and Alzheimer's. . Scientists are using such chimeras - animals whose bodies are a mosaic, with their own cells intermixed with those of another animal - to model diseases, test drugs on live human cells, and harvest organs for transplant. . But the blending of species also has raised a host of ethical and philosophical questions over the past year. . Last month, the George W. Bush's Council on Bioethics struggled to understand when a human-animal chimera is a useful tool, and when it becomes "high-tech bestiality." The United States turned down a seven-year-old patent application for a chimpanzee-human mix, the "humanzee," in February, with patent officers calling on Congress for guidance. Canada banned the creation of all chimeras last year. And the National Academy of Sciences is set to release ethical guidelines this month for researchers who use stem cells to create chimeras. . "The question is, where does it all end?" said Stuart Newman, a developmental biologist from New York Medical College who proposed the humanzee because he wanted to draw public attention to a morally questionable but technically feasible scientific project that might follow from some of today's experiments. "At some point, everyone will be offended." . Animal rights advocates argue that any manipulation of animals for human benefit, whether for dinner or for research, is immoral. . Christian teaching holds that the Bible gives people dominion over animals. . "That really means stewardship - you cannot abuse them for your good. But just as you would eat a pig or eat a cow, I see no problem in putting a pig valve in a human being or a pig kidney within a human being," said Dr. David Stevens, executive director of the Christian Medical Association, a U.S. group that advocates the practice of medicine from a religious perspective. . The problem arises, Stevens said, when scientists fundamentally alter what it means to be human or animal. "If you give an animal a human brain, if you give an animal human reproductive organs, if you make a human embryo that's not fully human, that crosses the ethical, moral, and biblical line." . The Roman Catholic Church has grave concerns that chimera research may create beings without a clear moral status. "I think it would be basically immoral to create a human whose status we could not determine. We'd have an unresolvable dilemma about how to treat this animal," said Richard Doerflinger, deputy director of the secretariat for pro-life activities at the U.S. Conference of Catholic Bishops. . The scientists doing work on chimeras see their work as ethical and responsible and believe it has tremendous potential benefit. . Charlotte Kuperwasser, a biologist at Tufts University, created a mouse with human breast tissue to solve a longstanding problem in research, that testing drugs by looking at cells in a dish or making a mouse version of the disease doesn't necessarily help actual patients. . Mouse cancers, she said, "'don't look like human tumors. They don't behave like the actual breast cancer. We can cure mouse breast cancers, but that can't always translate to the clinic." . By adding human breast cells to immune-deficient mice before puberty, Kuperwasser has been able to watch normal breast development and generate human cancers rather than mouse ones in her lab animals. Now, she is working to implant particular patients' cancer into mice to see if they can test drugs and cures on it without harming the person. . In Nebraska, William Beschorner is working to create a human immune system and humanized liver in a pig. Eventually the biologist hopes to replicate a particular patient's immune system and then transplant the pig's organs back into the person, where they would appear familiar to the immune system, and therefore wouldn't be rejected. . Even scientists pause, though, when experiments creep from basic organs to the seat of human consciousness - the brain - or when stem cells, controversial in their own right, are added to the mix. . Four years ago, Irving Weissman, a stem-cell biologist at Stanford, created a mouse with human neurons in its brain, hoping that the living model would provide insights into diseases like Parkinson's and Alzheimer's. . The human neurons made up about 1 percent of the mouse brain and were alive, but it was unclear whether they were functioning. He suggested another project: creating a mouse with 100 percent human nerve cells in its brain. . He asked an informal committee to review his proposal, and the group recently drew up guidelines for doing the experiment responsibly. . Hank Greely, head of that committee, described one clear limit. "If you see anything that is not unequivocally mouse behavior, you stop the experiment," he said. . Scientists agree that human brain cells growing in a mouse are unlikely to humanize a mouse because of the vast differences in skull size and brain architecture. But in a closely related animal, the threat of an animal floating somewhere between human and animal becomes more serious. . "What is essentially human is really debased," Alfonso Gomez-Lobo, a member of the Council on Bioethics, said in March. "I often imagine what it would be like to wake up one day only to realize that I have the body of a chimpanzee." . A chimera is an animal with its own cells and that of another animal growing side by side in its body. Scientists used to call such animals "tetraparental," meaning they had four parents - their own, and the parents of the other cells living in their bodies. . The "geep" is an example of a true chimera. Scientists at the University of California at Davis fused together sheep and goat embryos. In the offspring, every organ, including the sex organs, were made up of both goat and sheep cells, which meant that one geep could produce both goat and sheep sperm. . Many other kinds of chimeras are made by adding human cells to animals that have been genetically altered to have no immune system. Without the immune system, which would attack foreign cells, scientists can grow human brain cells or breast cells in another animal, often a mouse. . Chimeras surround us, and not just in the lab. Cardiac surgery patients who receive pig valves to repair their hearts are chimeras. Transplant recipients, who have another person's bone marrow, kidney, or heart thumping in their chest, are a kind of chimera, with the cells of another being living alongside their own. . . See more of the world that matters - click here for home delivery of the International Herald Tribune. . ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn