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Entries in Mice (11)

Monday
May072012

Yogurt Makes Mice Slimmer and Sexier, Study Finds

Jupiterimages/Thinkstock(CAMBRIDGE, Mass.) -- Scientists studying the power of probiotics to fight obesity got more than they bargained for: They found that yogurt not only makes mice slimmer, it also makes them sexier.

Studies in humans suggest eating yogurt may help stave off age-related weight gain.  But Massa­chusetts Institute of Technology researchers Eric Alm and Susan Erdman wanted to know why.

“Maybe it has to do with the healthy bacteria that live in our guts,” said Alm, an evolutionary biologist, explaining how there are 10 times more bacteria in the body than human cells.  “Maybe probiotics in the yogurt have something to do with the effects on weight.”

To test the theory, Alm and Erdman fed one group of mice a normal mouse diet and another group the same diet with a mouse-sized serving of vanilla yogurt.

“One of the first things we noticed was their fur coat,” said Erdman, assistant director of comparative medicine at MIT.  “It was so thick and shiny; shockingly shiny.”

But shiny fur wasn’t the only thing that set the yogurt-eating mice apart from their siblings: They were also slimmer, and the males had “swagger.”

“We knew there was something different in the males, but we weren’t sure what it was at first,” Erdman said.  “You know when someone’s at the top of their game, how they carry themselves differently?  Well, imagine that in a mouse.”

A lab technician would soon discover what was giving these males their sexy strut.

“She noticed their testicles were protruding out really far,” Erdman said.

It turns out their testicles were 5 percent bigger than those of their non-yogurt eating counterparts, and 15 percent bigger than those of mice on a diet designed to mimic “junk food” in humans.  And in this case, bigger was better.

“Almost everything about the fertility of those males is enhanced,” Erdman said, explaining how yogurt-eating males mated faster and produced more offspring.  “There were legitimate physiological differences in males fed probiotics, not just the extra sexiness.”

And let’s not forget the ladies.  Female mice that ate yogurt were even shinier than the males, and tended to be better moms to their larger litters.

“We think it’s the probiotics in the yogurt,” Alm said.  “We think those organisms are somehow directly interacting with the mice to produce these effects.”

Although the study is ongoing, the findings could have implications for human fertility, not to mention weight control and hair health.

Copyright 2012 ABC News Radio

Wednesday
Apr252012

Experimental Drug Improves Autism-Like Symptoms in Mice

Comstock/Thinkstock(WASHINGTON) -- Researchers have identified a novel compound that improved autism-like behaviors in mice, according to a new study published in the journal Science Translational Medicine.

Scientists from the National Institutes of Mental Health (NIMH) and Pfizer Worldwide Research and Development found that an experimental agent known as GRN-529 that inhibited the actions of a glutamate, a chemical in the brain, caused mice to be more social and engage in less repetitive grooming.  Social deficits and repetitive behaviors are two of the core symptoms of autism spectrum disorders.

While findings in mice may not always be applicable to humans and research into this compound is in a very early stage, lead researcher Jill Silverman of the NIMH said so far, the data are encouraging.

“This is the first step in a very long process,” she said.  “But the results are important because there are no drugs that are currently available to autistic patients that address any of the core symptoms.  The only drugs that are prescribed are for irritability that can lead to tantrums and for self-injurious behavior.”

The two approved drugs — Risperdal and Abilify — are anti-psychotics and can have dangerous side effects, she added.

The mice used in the study are commercially bred to exhibit symptoms that strongly resemble those often seen in autism.  They displayed very low levels of social interaction and also repeatedly groomed themselves so excessively that in some cases, their hair started to fall out, Silverman explained.

The mice also did not vocalize much, reflecting the communication deficits seen in people with autism.

The animals who received GRN-529 groomed themselves less and spent more time interacting with other mice.   Another group of mice exhibited less repetitive jumping.

In an accompanying editorial, Baltazar Gomez-Mancilla, a researcher with the pharmaceutical company Novartis, wrote that these findings along with previous study data suggest that the effects of these agents should soon be tested on humans with autism.

But it will take more research to determine whether any future drugs should be used at the time of diagnosis, and which patients could potentially benefit the most from this type of agent, since autism is so highly variable.

Copyright 2012 ABC News Radio

Thursday
Mar152012

Study: Cellphone Radiation Linked to Behavior Problems in Mice

Jupiterimages/Thinkstock(NEW HAVEN, Conn.) -- A new study could re-ignite the debate over the potentially dangerous effects of cellphone radiation on children's behavior.

Researchers from the Yale School of Medicine found that exposing pregnant mice to radiation from a cellphone affected the behavior of their offspring later.  They found that the mice exposed to radiation as fetuses were more hyperactive, had more anxiety and poorer memory -- symptoms associated with attention deficit hyperactivity disorder (ADHD) -- than mice who were not exposed to radiation.

Neurological tests revealed that the radiation exposure led to abnormal development of neurons in the part of the brain linked to ADHD, leading the authors to suggest that cellphone radiation exposure may play a role in the disorder.

"During critical windows in neurogenesis, the brain is susceptible to numerous environmental insults; common medically relevant exposures include ionizing radiation, alcohol, tobacco, drugs and stress," wrote the authors, led by Dr. Hugh Taylor, professor and chief of the Division of Reproductive Endocrinology and Infertility.

They added that while their study provides "the first experimental evidence of neuropathology due to in-utero cellular telephone radiation," the data are not conclusive, and more research is needed to determine the effects of radiation on humans or non-human primates.

Dr. F. Sessions Cole, professor of pediatrics and chief of newborn medicine at the Washington University School of Medicine in St. Louis, said that while the research is "provocative," the data are a long way from being applicable to humans.

"Mice are very different than humans," he said.  "The distance the phone was placed away from the mice in the study was between 4 and 20 centimeters, which is a very short distance compared to the distance from the ear to the womb in humans.  It's likely the dose of radiation the mice received is much greater than what a human fetus would receive."

Cole added that mice also have a much shorter gestation period, only 19 or 20 days, which can also mean a very different type of exposure than humans.

Copyright 2012 ABC News Radio

Tuesday
Jan032012

Stem Cell Shots Make Aging Mice Young Again

Comstock/Thinkstock(PITTSBURGH) -- Injecting younger cells into aging bodies could help people live longer -- and stronger, at least according to new research performed on mice.

Scientists said the research, published Tuesday in the journal Nature Communications, offered provocative new clues about the potential to treat aging and ailing cells, but it doesn't mean they've uncovered a new fountain of youth.

Researchers at the University of Pittsburgh Medical Center genetically altered mice to make them age faster, making them old and weak in a span of 17 days. The scientists then injected the mice with stem cell-like cells taken from the muscle of young, healthy mice.

The result was that they reversed the aging process. The rapidly aging mice lived up to three times longer, dying after 66 days, rather than 28 days. The cell injection also appeared to make the animals healthier, improving their muscle strength and brain blood flow.

In recent years, scientists have agreed that aging in both animals and humans begins when stem cells lose their ability to rejuvenate the body's tissues. While aging is universal, some researchers believe it may also be reversible.

The mice in the study had a condition of rapid aging called progeria, meaning they did not age normally, even by mouse standards. Normal mice live for about 800 days. Though the mice in the study lived nearly three times as long as they would have, they lived for only 66 days.

Copyright 2012 ABC News Radio

Thursday
Nov102011

Gene Mutation Makes Mice Twice as Strong, Fast

BananaStock/Thinkstock(BERN, Switzerland) -- Move over, Mighty Mouse.

Swiss researchers say they’ve found a way to make mice twice as strong and fast as the average mouse.

By tweaking signals from a part of a gene that typically stalls muscle growth in worms and mice, researchers saw them transform to exhibit super-strength.  

The mice with the gene mutation could run twice as fast and twice as long before getting tired, according to researchers, whose findings were published Thursday in the journal Cell.

The same gene inhibitor may also be responsible for human strength, suggesting that the method these scientists used on the mice and worms could one day translate to humans.

Many experts said muscle responses in humans are similar to those in mice.

“It will be interesting to learn whether this mechanism increases muscle size through the normal stem cells in muscle, or whether it occurs mainly by just increasing the size of existing muscles,” said Dr. Elizabeth McNally, director of the Institute for Cardiovascular Research at the University of Chicago, who was not involved in the study.

The researchers observed that muscle fibers in the mice with the mutation were denser, and the cells could deliver more energy to mice.

“This could be used to combat muscle weakness in the elderly, which leads to falls and contributes to hospitalization,” Johan Auwerx, the lead researcher, said in a statement.  

Some experts equated the new method to performance enhancers, such as supplements and steroids, fearing that the method could be abused by some athletes.

“While the use of this gene modulation is relatively far off in humans, it could open up Pandora’s box when it comes to the enhancing performance,” said Dr. Joseph Guettler, sports medicine orthopedic surgeon at William Beaumont Hospitals in Royal Oak, Mich.

Copyright 2011 ABC News Radio

Friday
Aug192011

Drug Makes Mice Live 44 Percent Longer: Hope for a Human Longevity Pill?

David De Lossy/Thinkstock(NEW YORK) -- While the Fountain of Youth is a legend, a fountain of longer life may be real.

According to an article in Thursday's issue of Scientific Reports, researchers have found a new drug that can make mice live 44 percent longer, on average, than similar mice who didn't get the drug. The drug is a synthetic compound called SRT1720, and it was developed by Sirtris, a pharmaceutical company in Cambridge, Mass.

The New York Times reported that studies are currently testing versions of SRT1720 on humans, the goal being a pill that will make this type of drug's benefits available to the general public.

In 2007, Nightline interviewed David Sinclair and Dr. Christoph Westphal, two of three co-chairs of Sirtris' Scientific Advisory Board. Sinclair was the company's scientific genius, Westphal its primary investor.

The pair shared a passion to capitalize on Sinclair's discovery that resveratrol, an ingredient of red wine, activated the genes that control aging, making mice who received it in his study live 30 percent longer than those who didn't. SRT1720 is designed to imitate resveratrol.

"Think of a Pac-Man controlling things in the cell, and resveratrol binds to the Pac-Man and makes it more active," Sinclair said, "and tells the cell to be more efficient, ramp up metabolic rate and overall health of the cell and [is] resistant to diseases of aging."

"If we are right, these drugs will be enormously successful drugs and treat very important diseases," Westphal told Nightline. "If we're right, this is a game-changer."

Copyright 2011 ABC News Radio

Wednesday
Apr062011

Fish Oil Boosts Breast Cancer Therapy in Mice, Study Finds

Comstock/Thinkstock(PHILADELPHIA) -- Pairing fish oils with drugs commonly prescribed for breast cancer could help bolster treatment of the disease, according to a new study presented at the 102nd annual American Association of Cancer Research meeting.

Researchers at the Fox Chase Cancer Center in Philadelphia tested the combination in mice, using tamoxifen, a commonly prescribed breast cancer drug, and fish oils.  They found that when both substances were paired together, the incidence of mammary tumors in the mice were reduced.

It is yet to be known if fish oil could have the same positive effect in human breast cancer patients.

Copyright 2011 ABC News Radio

Friday
Mar252011

Breakthrough: Japanese Researchers Grow Sperm in Lab

BananaStock/Thinkstock(YOKOHAMA, Japan) -- Researchers in Japan have grown functioning mouse sperm in a laboratory dish, a breakthrough that has been decades in the making and holds out new hope for millions of infertile men.

The research, reported Wednesday in the journal Nature, could help scientists understand several steps of spermatogenesis, or sperm formation, at the cellular level and ultimately lead to new treatments for male infertility.

Researcher Takehiko Ogawa of Yokohama City University not only grew healthy mouse sperm in the laboratory, but also used them to produce fertile offspring, according to the study.  The sperm were produced in a test tube from the cells taken from newborn mouse testicles, and then injected into eggs to produce to twelve healthy babies, four male and eight female, which were all fertile and able to have their own babies in adulthood.

"It's really exciting," said Mary Ann Handel, a reproductive genetics research scientist at Maine's Jackson Laboratory.  "I really do think that he's really achieved a goal that a lot of people have tried over the years."

"It is a significant breakthrough," said Martin Dym, a professor of biochemistry and molecular and cellular biology at Georgetown University.  Dym was part of a team that tried, and failed, to accomplish in vitro growth of functional sperm ten years ago.  "We did make sperm, but could not succeed in getting the sperm to make pups.  [The Japanese team] has better sperm."

The potential practical applications in humans would include treating infertility, which affects an estimated 8 to 12 percent of the male population.

"So far it's been done in mice," said Dym.  "You have to show that it can work in humans."

Copyright 2011 ABC News Radio

Monday
Mar212011

Powerful Tool May Get Us Closer to Understanding Autism

Comstock/ThinkstockPowerful Tool May Get Us Closer to Understanding Autism

(DURHAM, N.C.) -- Autism symptoms have been replicated in mice using one gene mutation, one of the first so-called single-gene knockouts that scientists say puts them another step closer to understanding a genetic link to autism, researchers at Duke University reported.

Their findings were published Sunday in the journal Nature.

Scientists examining genetic traits or environmental exposures that can contribute to autism have previously replicated behavioral symptoms of autism in mice. But these mouse models of autism replicated only a few specific behavioral traits associated with autism.

This new model, according to researchers, used a known gene mutation associated with autism -- called the SHANK3 gene mutation -- to replicate a wider range of behaviors that include impaired social interaction and repetitive behaviors.

Scientists have struggled for years to find effective medical treatments for autism, mainly because they have been unable to understand the pathways in the brain that cause the disorder.

Previous studies suggest that SHANK3 gene mutation is one of a series of rare genetic mutations that are linked to autism. The SHANK3 gene mutation has been identified in nearly 16 percent of children with autism. Earlier studies, however, do not pinpoint the exact role the mutations played in the disorder.

"Having an animal model that can teach us more about how a specific gene mutation is correlated with behavior is critically important to our understanding of the overall biology of autism," said Andy Shih, vice president of scientific affairs at the nonprofit Autism Speaks.

The current findings may offer some insight in the relationship between SHANK3 mutations and the characteristic traits of autism. Some experts say it's hard to tell whether insights that will be gained from the SHANK3 mutation will translate to the other genetic mutations that are associated with autism.

Still, Dr. Thomas Insel of the National Institutes of Health said, so-called single-gene knockouts such as this have been one of the first instrumental steps in better understanding the mechanism of many now manageable conditions in humans, including heart disease and hypertension.

"This is a big step," he said. "But we need a lot more big steps to get to finding early diagnostic and medical treatments.

"It doesn't yet tell us where a new treatment or diagnosis will be. But this is part of the process."

Copyright 2011 ABC New Radio

Sunday
Jan302011

Aging Can Be Reversed in Mice, But What About Us?

Photo Courtesy - Getty Images(BOSTON) -- Scientists have found that by tweaking the genes of mice, they are able to slow, or even reverse the process of aging. With just a few changes, the animals were able to regenerate brain cells, and their fertility was able to be restored. Alternatively, mice aged prematurely when those changes were made in reverse order.

A report, published in the weekly online science journal Nature, shows that scientists hope similar results may be possible for humans down the road. The scientists who published the report, working out of the Dana Farber Cancer Center in Boston, worked with the chromosomes that are found inside the nuclei of all cells. By transforming the protective part of the chromosome, which guards the cell from diminishing, scientists could either accelerate, or reverse the aging process.

Some scientists say the study can be beneficial if the process eventually leads to cures for things like heart disease and diabetes, which become more debilitating with age.

So far the study has been restricted to mice.

Copyright 2011 ABC News Radio







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