Monkeys Born From Eggs With DNA Transplant
Malcolm Ritter, Associated Press
http://dsc.discovery.com/news/2009/08/26/monkey-dna-transfer.html
Born From DNA-Altered Egg | Discovery News Video
Aug. 26, 2009 -- An experimental procedure that someday may enable women to avoid passing certain genetic diseases on to their children has gained an early success, with the birth of four healthy monkeys, scientists report.
The technique still faces safety questions and perhaps ethical hurdles, but an expert called the work exciting.
The experiment, which involved transferring DNA between eggs from rhesus macaques, was described Wednesday on the Web site of the journal Nature by researchers from the Oregon Health and Science University.
Someday, the technique may be used against diseases caused by inherited defects in the "power plants" of cells, called mitochondria. These conditions are uncommon and unfamiliar to most people, such as Leber hereditary optic neuropathy. Roughly one person in every 4,000 or 5,000 either has one of these mitochondrial diseases or is at risk for one.
Symptoms of these potentially fatal illnesses include muscle weakness, dementia, movement disorders, blindness, hearing loss, and problems of the heart, muscle and kidney.
An egg contains the vast majority of its DNA in the nucleus, but mitochondria contain DNA elsewhere in the egg. So if a woman has a disease caused by defects in the mitochondrial DNA, the new technique might someday make it possible for her to pass on her normal DNA from the nucleus but not the flawed DNA from the mitochondria.
To allow for that, doctors may transplant nucleus DNA from the eggs of such women into donor eggs that have healthy mitochondria. The donor eggs would have had their own nucleus DNA removed. After test-tube fertilization, this egg would in theory produce a baby without mitochondrial defects. (Fathers do not pass along their mitochondria.)
Researcher Shoukhrat Mitalipov said more safety studies must be done in monkeys. He noted that the technique would face regulatory hurdles for human studies because it would change the DNA inherited by future generations, an idea that has long provoked ethical concerns.
Douglas Wallace of the University of California, Irvine, an authority on mitochondria who wasn't involved in the federally funded experiment, said the results were exciting and the technique is "potentially very interesting."
But "there are safety issues that are going to need to be addressed before one could think about it in humans," Wallace said.
Friday, August 28, 2009
Kidney dialysis machine 'small enough to be worn as a belt'
Scientists have developed a kidney dialysis machine small enough to be worn as a belt which can allow patients to receive the treatment as they walk around.
By Kate Devlin, Medical Correspondent
Published: 8:00AM BST 21 Aug 2009
The breakthrough could potentially free thousands of patients from attending hospital every other day.
More than 25,000 people in Britain need to have regular dialysis, usually around three times a week, because their kidneys do not function properly.
Described as “small and light enough to be wearable”, the battery-powered machine weighs around 10lb.
Researchers hope that the device will give patients the freedom to have their treatment whenever and wherever they choose.
Dr Victor Gura, from the David Geffen School of Medicine at UCLA, one of the team behind the new machine, said: “Our vision of a technological breakthrough has materialized in the form of a Wearable Artificial Kidney, which provides continuous dialysis 24 hours a day, seven days a week.”
While hospital patients have to receive a fairly intensive form of dialysis, because of the limited time available, the researchers hope that this machine can offer a gentler form, more akin to that provided naturally by the kidneys themselves.
The researchers are carrying out preliminary tests on the machine, including in patients who need dialysis.
“However, the long-term effect of this technology on the well-being of dialysis patients must be demonstrated in much-needed clinical trials,” Dr Gura said.
“Although successful, this is but one additional step on a long road still ahead of us to bring about a much-needed change in the lives of this population.”
Timothy Statham, chief executive of the National Kidney Federation (NKF) said that few patients would want round the clock dialysis but many would appreciate the extra freedom the device could offer.
He added that many of the estimated two per cent of patients who had been able to have more regular dialysis, thorough machines in their own homes, had seen “remarkable results”.
The findings are published in the Clinical Journal of the American Society of Nephrology.
By Kate Devlin, Medical Correspondent
Published: 8:00AM BST 21 Aug 2009
The breakthrough could potentially free thousands of patients from attending hospital every other day.
More than 25,000 people in Britain need to have regular dialysis, usually around three times a week, because their kidneys do not function properly.
Described as “small and light enough to be wearable”, the battery-powered machine weighs around 10lb.
Researchers hope that the device will give patients the freedom to have their treatment whenever and wherever they choose.
Dr Victor Gura, from the David Geffen School of Medicine at UCLA, one of the team behind the new machine, said: “Our vision of a technological breakthrough has materialized in the form of a Wearable Artificial Kidney, which provides continuous dialysis 24 hours a day, seven days a week.”
While hospital patients have to receive a fairly intensive form of dialysis, because of the limited time available, the researchers hope that this machine can offer a gentler form, more akin to that provided naturally by the kidneys themselves.
The researchers are carrying out preliminary tests on the machine, including in patients who need dialysis.
“However, the long-term effect of this technology on the well-being of dialysis patients must be demonstrated in much-needed clinical trials,” Dr Gura said.
“Although successful, this is but one additional step on a long road still ahead of us to bring about a much-needed change in the lives of this population.”
Timothy Statham, chief executive of the National Kidney Federation (NKF) said that few patients would want round the clock dialysis but many would appreciate the extra freedom the device could offer.
He added that many of the estimated two per cent of patients who had been able to have more regular dialysis, thorough machines in their own homes, had seen “remarkable results”.
The findings are published in the Clinical Journal of the American Society of Nephrology.
Wednesday, August 19, 2009
DNA Evidence Can Be Fabricated, Scientists Show
http://www.nytimes.com/2009/08/18/science/18dna.html?_r=3&pagewanted=print
August 18, 2009
DNA Evidence Can Be Fabricated, Scientists Show
By ANDREW POLLACK
Scientists in Israel have demonstrated that it is possible to fabricate DNA evidence, undermining the credibility of what has been considered the gold standard of proof in criminal cases.
The scientists fabricated blood and saliva samples containing DNA from a person other than the donor of the blood and saliva. They also showed that if they had access to a DNA profile in a database, they could construct a sample of DNA to match that profile without obtaining any tissue from that person.
“You can just engineer a crime scene,” said Dan Frumkin, lead author of the paper, which has been published online by the journal Forensic Science International: Genetics. “Any biology undergraduate could perform this.”
Dr. Frumkin is a founder of Nucleix, a company based in Tel Aviv that has developed a test to distinguish real DNA samples from fake ones that it hopes to sell to forensics laboratories.
The planting of fabricated DNA evidence at a crime scene is only one implication of the findings. A potential invasion of personal privacy is another.
Using some of the same techniques, it may be possible to scavenge anyone’s DNA from a discarded drinking cup or cigarette butt and turn it into a saliva sample that could be submitted to a genetic testing company that measures ancestry or the risk of getting various diseases. Celebrities might have to fear “genetic paparazzi,” said Gail H. Javitt of the Genetics and Public Policy Center at Johns Hopkins University.
Tania Simoncelli, science adviser to the American Civil Liberties Union, said the findings were worrisome.
“DNA is a lot easier to plant at a crime scene than fingerprints,” she said. “We’re creating a criminal justice system that is increasingly relying on this technology.”
John M. Butler, leader of the human identity testing project at the National Institute of Standards and Technology, said he was “impressed at how well they were able to fabricate the fake DNA profiles.” However, he added, “I think your average criminal wouldn’t be able to do something like that.”
The scientists fabricated DNA samples two ways. One required a real, if tiny, DNA sample, perhaps from a strand of hair or drinking cup. They amplified the tiny sample into a large quantity of DNA using a standard technique called whole genome amplification.
Of course, a drinking cup or piece of hair might itself be left at a crime scene to frame someone, but blood or saliva may be more believable.
The authors of the paper took blood from a woman and centrifuged it to remove the white cells, which contain DNA. To the remaining red cells they added DNA that had been amplified from a man’s hair.
Since red cells do not contain DNA, all of the genetic material in the blood sample was from the man. The authors sent it to a leading American forensics laboratory, which analyzed it as if it were a normal sample of a man’s blood.
The other technique relied on DNA profiles, stored in law enforcement databases as a series of numbers and letters corresponding to variations at 13 spots in a person’s genome.
From a pooled sample of many people’s DNA, the scientists cloned tiny DNA snippets representing the common variants at each spot, creating a library of such snippets. To prepare a DNA sample matching any profile, they just mixed the proper snippets together. They said that a library of 425 different DNA snippets would be enough to cover every conceivable profile.
Nucleix’s test to tell if a sample has been fabricated relies on the fact that amplified DNA — which would be used in either deception — is not methylated, meaning it lacks certain molecules that are attached to the DNA at specific points, usually to inactivate genes.
Copyright 2009 The New York Times Company
August 18, 2009
DNA Evidence Can Be Fabricated, Scientists Show
By ANDREW POLLACK
Scientists in Israel have demonstrated that it is possible to fabricate DNA evidence, undermining the credibility of what has been considered the gold standard of proof in criminal cases.
The scientists fabricated blood and saliva samples containing DNA from a person other than the donor of the blood and saliva. They also showed that if they had access to a DNA profile in a database, they could construct a sample of DNA to match that profile without obtaining any tissue from that person.
“You can just engineer a crime scene,” said Dan Frumkin, lead author of the paper, which has been published online by the journal Forensic Science International: Genetics. “Any biology undergraduate could perform this.”
Dr. Frumkin is a founder of Nucleix, a company based in Tel Aviv that has developed a test to distinguish real DNA samples from fake ones that it hopes to sell to forensics laboratories.
The planting of fabricated DNA evidence at a crime scene is only one implication of the findings. A potential invasion of personal privacy is another.
Using some of the same techniques, it may be possible to scavenge anyone’s DNA from a discarded drinking cup or cigarette butt and turn it into a saliva sample that could be submitted to a genetic testing company that measures ancestry or the risk of getting various diseases. Celebrities might have to fear “genetic paparazzi,” said Gail H. Javitt of the Genetics and Public Policy Center at Johns Hopkins University.
Tania Simoncelli, science adviser to the American Civil Liberties Union, said the findings were worrisome.
“DNA is a lot easier to plant at a crime scene than fingerprints,” she said. “We’re creating a criminal justice system that is increasingly relying on this technology.”
John M. Butler, leader of the human identity testing project at the National Institute of Standards and Technology, said he was “impressed at how well they were able to fabricate the fake DNA profiles.” However, he added, “I think your average criminal wouldn’t be able to do something like that.”
The scientists fabricated DNA samples two ways. One required a real, if tiny, DNA sample, perhaps from a strand of hair or drinking cup. They amplified the tiny sample into a large quantity of DNA using a standard technique called whole genome amplification.
Of course, a drinking cup or piece of hair might itself be left at a crime scene to frame someone, but blood or saliva may be more believable.
The authors of the paper took blood from a woman and centrifuged it to remove the white cells, which contain DNA. To the remaining red cells they added DNA that had been amplified from a man’s hair.
Since red cells do not contain DNA, all of the genetic material in the blood sample was from the man. The authors sent it to a leading American forensics laboratory, which analyzed it as if it were a normal sample of a man’s blood.
The other technique relied on DNA profiles, stored in law enforcement databases as a series of numbers and letters corresponding to variations at 13 spots in a person’s genome.
From a pooled sample of many people’s DNA, the scientists cloned tiny DNA snippets representing the common variants at each spot, creating a library of such snippets. To prepare a DNA sample matching any profile, they just mixed the proper snippets together. They said that a library of 425 different DNA snippets would be enough to cover every conceivable profile.
Nucleix’s test to tell if a sample has been fabricated relies on the fact that amplified DNA — which would be used in either deception — is not methylated, meaning it lacks certain molecules that are attached to the DNA at specific points, usually to inactivate genes.
Copyright 2009 The New York Times Company
X-ray machines 'could be helping to spread infection'
X-ray machines could be helping to spread infection in intensive care units, a new study has found.
http://www.telegraph.co.uk/health/healthnews/5978059/X-ray-machines-could-be-helping-to-spread-infection.html
By Kate Devlin, Medical Correspondent
Published: 7:00AM BST 06 Aug 2009
Researchers found that one in three x-ray machines that they tested carried bacteria which could cause infections Photo: GETTY
Researchers found that one in three of the machines that they tested carried bacteria which could cause infections.
They warn that better cleaning of the equipment could reduce the chance of spreading potentially dangerous infections within hospitals.
X-ray photographs
Official figures show that there were more than 20 million x-rays taken in British hospitals over the last year.
The scans are used to diagnose and help treat a wide range of illnesses and conditions.
But researchers in Israel warn that the machines themselves could be helping to increase the number of hospital-acquired infections.
They found that 130 of the 406 machines that they tested contained forms of bacteria called drug resistant gram-negative bacteria.
Last year the Health Protection Agency warned that there was an urgent need for new antibiotics to deal with gram-negative bacteria, a group which includes E.coli, which had become resistant to medication.
The findings of the study are published in CHEST, the journal of the American College of Chest Physicians.
http://www.telegraph.co.uk/health/healthnews/5978059/X-ray-machines-could-be-helping-to-spread-infection.html
By Kate Devlin, Medical Correspondent
Published: 7:00AM BST 06 Aug 2009
Researchers found that one in three x-ray machines that they tested carried bacteria which could cause infections Photo: GETTY
Researchers found that one in three of the machines that they tested carried bacteria which could cause infections.
They warn that better cleaning of the equipment could reduce the chance of spreading potentially dangerous infections within hospitals.
X-ray photographs
Official figures show that there were more than 20 million x-rays taken in British hospitals over the last year.
The scans are used to diagnose and help treat a wide range of illnesses and conditions.
But researchers in Israel warn that the machines themselves could be helping to increase the number of hospital-acquired infections.
They found that 130 of the 406 machines that they tested contained forms of bacteria called drug resistant gram-negative bacteria.
Last year the Health Protection Agency warned that there was an urgent need for new antibiotics to deal with gram-negative bacteria, a group which includes E.coli, which had become resistant to medication.
The findings of the study are published in CHEST, the journal of the American College of Chest Physicians.
Saturday, August 15, 2009
Gene Therapy Creates a New Fovea, Blind from birth and can now read
Friday, August 14, 2009
Gene Therapy Creates a New Fovea
Treatment leads to an unexpected improvement in vision for one patient.
By Emily Singer
Twelve months after receiving an experimental gene therapy for a rare, inherited form of blindness, a patient discovered that she could read an illuminated clock in the family car for the first time in her life. The unexpected findings suggest that the brain can adapt to new sensory capacity, even in people who have been blind since birth.
The patient, who remains anonymous, suffers from a disease called Leber congenital amaurosis, in which an abnormal protein in sufferers' photoreceptors severely impairs their sensitivity to light. "It's like wearing several pairs of sunglasses in a dark room," says Artur Cideciyan, a researcher at the University of Pennsylvania in Philadelphia, who oversaw the trial.
At the start of the study, physicians injected a gene encoding a functional copy of the protein into a small part of one eye--about eight-to-nine millimeters in diameter--of three patients, all in their twenties and blind since birth. In preliminary results published last year, Cideciyan and colleagues found that all three patients showed substantial improvements in their ability to detect light three months after treatment.
The researchers have now published new results of the study in the journal Human Gene Therapy, showing that these improvements remained stable after one year. And in a letter to the New England Journal of Medicine, they describe surprising gains in one patient's vision. "It was unexpected because the major improvement of vision had occurred within weeks after the treatment," says Cideciyan.
Probing further, the researchers found that the patient appeared to be using the treated part of her eye like a second fovea--the part of the retina that is most densely populated with photoreceptors and is typically used for detailed vision, such as reading. The patient could detect dimmer light using the treated region than she could with her natural fovea. "We realized she was slowly adapting to her newfound vision by subconsciously focusing her attention to the treated area as opposed to the untreated central fovea," says Cideciyan. "It suggests that there is a plasticity, an ability to adapt in the adult visual brain."
"It's very encouraging," says Kang Zhang, an ophthalmologist and director of the Institute for Genomic Medicine at the University of California, San Diego, who was not involved in the study. "The formation of almost another vision center has implications as we go forward for patients with congenital blindness. They might not be able to use their normal fovea, but they might be able to develop a new center of vision."
Researchers now plan to study other patients in the trial to determine if they have experienced similar improvements. They also hope to figure out how to accelerate these gains, perhaps by using visual training targeted to the area treated with gene therapy.
The scientists also say that the fact that patients' visual improvements held for a year after injection is promising. "It means that for congenital or childhood blindness," says Zhang, "there is the potential to at least stabilize, if not improve, visual function."
Copyright Technology Review 2009.
Gene Therapy Creates a New Fovea
Treatment leads to an unexpected improvement in vision for one patient.
By Emily Singer
Twelve months after receiving an experimental gene therapy for a rare, inherited form of blindness, a patient discovered that she could read an illuminated clock in the family car for the first time in her life. The unexpected findings suggest that the brain can adapt to new sensory capacity, even in people who have been blind since birth.
The patient, who remains anonymous, suffers from a disease called Leber congenital amaurosis, in which an abnormal protein in sufferers' photoreceptors severely impairs their sensitivity to light. "It's like wearing several pairs of sunglasses in a dark room," says Artur Cideciyan, a researcher at the University of Pennsylvania in Philadelphia, who oversaw the trial.
At the start of the study, physicians injected a gene encoding a functional copy of the protein into a small part of one eye--about eight-to-nine millimeters in diameter--of three patients, all in their twenties and blind since birth. In preliminary results published last year, Cideciyan and colleagues found that all three patients showed substantial improvements in their ability to detect light three months after treatment.
The researchers have now published new results of the study in the journal Human Gene Therapy, showing that these improvements remained stable after one year. And in a letter to the New England Journal of Medicine, they describe surprising gains in one patient's vision. "It was unexpected because the major improvement of vision had occurred within weeks after the treatment," says Cideciyan.
Probing further, the researchers found that the patient appeared to be using the treated part of her eye like a second fovea--the part of the retina that is most densely populated with photoreceptors and is typically used for detailed vision, such as reading. The patient could detect dimmer light using the treated region than she could with her natural fovea. "We realized she was slowly adapting to her newfound vision by subconsciously focusing her attention to the treated area as opposed to the untreated central fovea," says Cideciyan. "It suggests that there is a plasticity, an ability to adapt in the adult visual brain."
"It's very encouraging," says Kang Zhang, an ophthalmologist and director of the Institute for Genomic Medicine at the University of California, San Diego, who was not involved in the study. "The formation of almost another vision center has implications as we go forward for patients with congenital blindness. They might not be able to use their normal fovea, but they might be able to develop a new center of vision."
Researchers now plan to study other patients in the trial to determine if they have experienced similar improvements. They also hope to figure out how to accelerate these gains, perhaps by using visual training targeted to the area treated with gene therapy.
The scientists also say that the fact that patients' visual improvements held for a year after injection is promising. "It means that for congenital or childhood blindness," says Zhang, "there is the potential to at least stabilize, if not improve, visual function."
Copyright Technology Review 2009.
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