By Maggie Fox, Health and Science Editor
WASHINGTON | Thu Aug 5, 2010 2:22pm EDT
WASHINGTON (Reuters) - Two studies published on Thursday show new ways to fix damaged hearts, one by turning structural heart cells into beating cells and another by restoring a primordial ability to regenerate lost tissue.
The two approaches need more work before they can be tried in humans, but they represent big steps forward in the new field of regenerative medicine.
And they show it may be possible to repair broken organs in the patient's body, instead of resorting to transplants or artificial devices.
In one study, a team at the Gladstone Institute of Cardiovascular Disease at the University of California, San Francisco made beating heart cells from more ordinary cells called fibroblasts.
Stem cell researchers know they can reprogram these ordinary cells by adding three or four genes to take them back to an embryonic-like state. Teams are working to fine-tune these so-called induced pluripotent stem cells or iPS cells.
Taking this approach a step further, Dr. Masaki Ieda and colleagues found the genes that, in a developing embryo, turn an immature cell into a beating heart cell or cardiomyocyte.
They used these three genes called Gata4, Mef2c, and Tbx5 to convert mouse heart fibroblasts -- which provide structure but which cannot beat -- into the beating cells.
"Scientists have tried for 20 years to convert nonmuscle cells into heart muscle, but it turns out we just needed the right combination of genes at the right dose," Ieda, now at the Keio University School of Medicine in Japan, said in a statement.
When they put these transformed cells into living mice, they converted into beating heart cells within a day, Ieda's team reported in the journal Cell.
CURING HEART FAILURE?
When patients suffer heart attacks, heart cells die as they become starved of oxygen. If enough dead tissue forms, patients suffer heart failure and eventually often die.
Scientists have been trying a variety of ways to regenerate this scar tissue, but patients with severe heart failure must use mechanical devices or hope for heart transplants.
Currently, 5 million Americans suffer from heart failure.
The approach will need a lot of refining, said Gladstone director Dr. Deepak Srivastava. "Direct reprogramming has not yet been done in human cells," he said. And it would be better to find a drug that can turn on the required genes; currently researchers usually use a virus to carry new genes into the cells.
For the second study, a team at California's Stanford University looked to amphibians called newts.
"Newts regenerate tissues very effectively," said Helen Blau of Stanford's Institute for Stem Cell Biology and Regenerative Medicine.
"In contrast, mammals are pathetic. We can regenerate our livers, and that's about it."
Also working in mice, Blau's looked for the reasons that amphibians can regenerate limbs and mammals cannot.
Other studies suggest that mammals have had to give up regeneration because the same process can also lead to cancer. A so-called tumor suppressor gene called retinoblastoma, or Rb, helps control this process in mammals.
"We hypothesized that maybe, during evolution, humans gained a tumor suppressor not present in lower animals at the expense of regeneration," Blau said.
They found a second gene called ARF is also involved.
When they blocked both Rb and ARF in mouse heart muscle cells, they started to grow and divide.
The key will be to control this process, so the cells do not overproliferate and form tumors, the researchers report in the journal Cell Stem Cell. They also want to see if this will work in other organs.
DETROIT | Wed Aug 4, 2010 4:47pm EDT
DETROIT (Reuters) - A Michigan man credited his dog with saving his life by chewing off his diseased big toe as he lay passed out in a drunken stupor.
Jerry Douthett, 48, woke up on a Saturday night in late July in his Rockford, Michigan home to find his Jack Russell Terrier, Kiko, had gnawed off his right big toe.
"The dog always lays with me on the bed," said Douthett. "That night, I woke up and looked down at my foot, and it was wet. When I looked it was blood, and there was the dog looking at me with a blood mustache."
Douthett's wife, Rosee, rushed him to a hospital where doctors found he was suffering from Type 2 diabetes. His toe was badly infected and surgeons amputated the remainder of the digit.
Douthett's wife, a registered nurse, had been urging him for weeks to have his infected toe examined by a doctor.
On the night Kiko ate his toe, Douthett said he had been out with his wife and drank about "six or seven beers" and a pair of giant margaritas "big enough to put goldfish in."
"I was self-medicating at this point," he said. "The moral of the story is that the dog saved my life, because otherwise I never would have gone in to see a doctor."
The couple said they were amazed that Kiko appeared to know Douthett had an infection that needed treatment.
"He kind of chewed off the infected part and stopped at the good bone," said Rosee. "We joked that we shouldn't have had to pay the co-pay because he did half the job by chewing off half of the toe."
By Isabel Coles
LONDON | Thu Aug 5, 2010 1:48pm EDT
LONDON (Reuters Life!) - He may leave his socks lying around and avoid emptying the dishwasher, but a new study shows husbands do as much work as their wives.
London School of Economics sociologist Catherine Hakim's research shows that when both paid work and unpaid duties such as housework, care and voluntary work are taken into account, men do pull their own weight.
"It's true that women do more work in the home, but overall men and women are doing the same, which is roughly eight hours per day," Hakim told Reuters.
In fact, the study of how people use their time found that men in Britain spend slightly longer on "productive" work each day than women.
"Feminists are wrong to claim that men should do a larger share of the housework and childcare because on average, men and women already do the same number of hours of productive work," Hakim said.
She said the data overturns the long-standing theory that women work a "double shift," juggling a job with household chores, and working longer hours than their husbands.
The study, "(How) can social policy and fiscal policy recognize unpaid family work?," used data from Europe-wide Time Use Surveys.
"Results were similar across Europe, except in the ex-socialist European countries, where there is less of a tradition of men chipping in," Hakim said.
In Scandinavian countries, men were found to work more hours than women.
Hakim hopes to draw attention to the bias of government policy across Europe, which tends only to see paid jobs as real work and said there is evidence that men are beginning to demand the same options and choices as women, with more claims of sex discrimination from men.
"One-sided policies that support employment and careers but ignore the productive work done in the family are, in effect, endorsing market place values over family values," she said.
"Policy-makers need to be aiming for gender-neutral policies."
WASHINGTON | Thu Aug 5, 2010 2:22pm EDT
WASHINGTON (Reuters) - Two studies published on Thursday show new ways to fix damaged hearts, one by turning structural heart cells into beating cells and another by restoring a primordial ability to regenerate lost tissue.
The two approaches need more work before they can be tried in humans, but they represent big steps forward in the new field of regenerative medicine.
And they show it may be possible to repair broken organs in the patient's body, instead of resorting to transplants or artificial devices.
In one study, a team at the Gladstone Institute of Cardiovascular Disease at the University of California, San Francisco made beating heart cells from more ordinary cells called fibroblasts.
Stem cell researchers know they can reprogram these ordinary cells by adding three or four genes to take them back to an embryonic-like state. Teams are working to fine-tune these so-called induced pluripotent stem cells or iPS cells.
Taking this approach a step further, Dr. Masaki Ieda and colleagues found the genes that, in a developing embryo, turn an immature cell into a beating heart cell or cardiomyocyte.
They used these three genes called Gata4, Mef2c, and Tbx5 to convert mouse heart fibroblasts -- which provide structure but which cannot beat -- into the beating cells.
"Scientists have tried for 20 years to convert nonmuscle cells into heart muscle, but it turns out we just needed the right combination of genes at the right dose," Ieda, now at the Keio University School of Medicine in Japan, said in a statement.
When they put these transformed cells into living mice, they converted into beating heart cells within a day, Ieda's team reported in the journal Cell.
CURING HEART FAILURE?
When patients suffer heart attacks, heart cells die as they become starved of oxygen. If enough dead tissue forms, patients suffer heart failure and eventually often die.
Scientists have been trying a variety of ways to regenerate this scar tissue, but patients with severe heart failure must use mechanical devices or hope for heart transplants.
Currently, 5 million Americans suffer from heart failure.
The approach will need a lot of refining, said Gladstone director Dr. Deepak Srivastava. "Direct reprogramming has not yet been done in human cells," he said. And it would be better to find a drug that can turn on the required genes; currently researchers usually use a virus to carry new genes into the cells.
For the second study, a team at California's Stanford University looked to amphibians called newts.
"Newts regenerate tissues very effectively," said Helen Blau of Stanford's Institute for Stem Cell Biology and Regenerative Medicine.
"In contrast, mammals are pathetic. We can regenerate our livers, and that's about it."
Also working in mice, Blau's looked for the reasons that amphibians can regenerate limbs and mammals cannot.
Other studies suggest that mammals have had to give up regeneration because the same process can also lead to cancer. A so-called tumor suppressor gene called retinoblastoma, or Rb, helps control this process in mammals.
"We hypothesized that maybe, during evolution, humans gained a tumor suppressor not present in lower animals at the expense of regeneration," Blau said.
They found a second gene called ARF is also involved.
When they blocked both Rb and ARF in mouse heart muscle cells, they started to grow and divide.
The key will be to control this process, so the cells do not overproliferate and form tumors, the researchers report in the journal Cell Stem Cell. They also want to see if this will work in other organs.
DETROIT | Wed Aug 4, 2010 4:47pm EDT
DETROIT (Reuters) - A Michigan man credited his dog with saving his life by chewing off his diseased big toe as he lay passed out in a drunken stupor.
Jerry Douthett, 48, woke up on a Saturday night in late July in his Rockford, Michigan home to find his Jack Russell Terrier, Kiko, had gnawed off his right big toe.
"The dog always lays with me on the bed," said Douthett. "That night, I woke up and looked down at my foot, and it was wet. When I looked it was blood, and there was the dog looking at me with a blood mustache."
Douthett's wife, Rosee, rushed him to a hospital where doctors found he was suffering from Type 2 diabetes. His toe was badly infected and surgeons amputated the remainder of the digit.
Douthett's wife, a registered nurse, had been urging him for weeks to have his infected toe examined by a doctor.
On the night Kiko ate his toe, Douthett said he had been out with his wife and drank about "six or seven beers" and a pair of giant margaritas "big enough to put goldfish in."
"I was self-medicating at this point," he said. "The moral of the story is that the dog saved my life, because otherwise I never would have gone in to see a doctor."
The couple said they were amazed that Kiko appeared to know Douthett had an infection that needed treatment.
"He kind of chewed off the infected part and stopped at the good bone," said Rosee. "We joked that we shouldn't have had to pay the co-pay because he did half the job by chewing off half of the toe."
By Isabel Coles
LONDON | Thu Aug 5, 2010 1:48pm EDT
LONDON (Reuters Life!) - He may leave his socks lying around and avoid emptying the dishwasher, but a new study shows husbands do as much work as their wives.
London School of Economics sociologist Catherine Hakim's research shows that when both paid work and unpaid duties such as housework, care and voluntary work are taken into account, men do pull their own weight.
"It's true that women do more work in the home, but overall men and women are doing the same, which is roughly eight hours per day," Hakim told Reuters.
In fact, the study of how people use their time found that men in Britain spend slightly longer on "productive" work each day than women.
"Feminists are wrong to claim that men should do a larger share of the housework and childcare because on average, men and women already do the same number of hours of productive work," Hakim said.
She said the data overturns the long-standing theory that women work a "double shift," juggling a job with household chores, and working longer hours than their husbands.
The study, "(How) can social policy and fiscal policy recognize unpaid family work?," used data from Europe-wide Time Use Surveys.
"Results were similar across Europe, except in the ex-socialist European countries, where there is less of a tradition of men chipping in," Hakim said.
In Scandinavian countries, men were found to work more hours than women.
Hakim hopes to draw attention to the bias of government policy across Europe, which tends only to see paid jobs as real work and said there is evidence that men are beginning to demand the same options and choices as women, with more claims of sex discrimination from men.
"One-sided policies that support employment and careers but ignore the productive work done in the family are, in effect, endorsing market place values over family values," she said.
"Policy-makers need to be aiming for gender-neutral policies."