Old mice, young blood: Rejuvenating blood of mice by reprogramming stem cells that produce blood

Mar. 25, 2013 ? The blood of young and old people differs. In an article published recently in the scientific journal Blood, a research group at Lund University in Sweden explain how they have succeeded in rejuvenating the blood of mice by reversing, or re-programming, the stem cells that produce blood.

Stem cells form the origin of all the cells in the body and can divide an unlimited number of times. When stem cells divide, one cell remains a stem cell and the other matures into the type of cell needed by the body, for example a blood cell.*

"Our ageing process is a consequence of changes in our stem cells over time," explained Martin Wahlestedt, a doctoral student in stem cell biology at the Faculty of Medicine at Lund University, and principal author of the article.

"Some of the changes are irreversible, for example damage to the stem cells' DNA, and some could be gradual changes, known as epigenetic changes, that are not necessarily irreversible, even if they are maintained through multiple cell divisions. When the stem cells are re-programmed, as we have done, the epigenetic changes are cancelled."**

The discovery that forms the basis for the research group's method was awarded the Nobel Prize in Medicine last year.

The composition of blood is one example of how it ages; blood from a young person contains a certain mix of B- and T-lymphocytes and myeloid cells.***

"In older people, the number of B- and T-lymphocytes falls, while the number of myeloid cells increases," said Martin Wahlestedt.

When an elderly person is affected by leukemia, the cancer often has its origin in the myeloid cells, of which the elderly have more. Being able to 're-start' the blood, as Martin and his colleagues have done in their studies on mice, therefore presents interesting possibilities for future treatment.

"There is a lot of focus on how stem cells could be used in different treatments, but all that they are routinely used for in clinical work today is bone marrow transplants for diseases where the blood and immune systems have to be regenerated," said Martin Wahlestedt, continuing:

"A critical factor that gives an indication of whether the procedure is going to work or not is the age of the bone marrow donor. By reversing the development of the stem cells in the bone marrow, it may be possible to avoid negative age-related changes."

Even if the composition of the blood in old and young mice is remarkably like that in young and elderly people, Martin Wahlestedt stressed that the science is still only at the stage of basic research, far from a functioning treatment. The research group is pleased with the results, because they indicate that it may not primarily be damage to DNA that causes blood to age, but rather the reversible epigenetic changes.

*About stem cells:

There are different types of stem cells. Embryonic stem cells, which can be extracted from an embryo at an early stage, have the capacity to develop into all types of cell. Stem cells are also found in adults, where they have more limited development potential, but can divide in principle an unlimited number of times. For example, blood cell-forming stem cells in bone marrow create all types of blood cell and stem cells in the brain create many different types of brain cell.

**About epigenetics:

Epigenetics is a term that has historically been used to describe the aspects of genetics that cannot be explained by the composition of an individual's DNA alone. For tissue and organs to form, a number of different types of cell must be developed. This happens through the activation and de-activation of different genes. When a cell formed in this manner then divides again, the gene expression can be maintained in the daughter cells. This is referred to as 'epigenetic inheritance'. The epigenetic mechanisms, or which genes are activated or de-activated, can be affected by factors such as age, chemicals, drugs and diet.

*** About the composition of blood:

B- and T-lymphocytes and myeloid cells are all white blood cells. Lymphocytes, as the name suggests, are particularly common in the lymphatic system. T-lymphocytes patrol the body and recognise a specific bacteria or virus. B-lymphocytes 'remember' old infections and can quickly be activated again if required. This memory capacity is the mechanism behind immunity. The myeloid cells belong to the blood system's 'big eaters' -- they neutralise damaged tissue, dead cells, and to a certain extent also bacteria.

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Story Source:

The above story is reprinted from materials provided by Lund University.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. M. Wahlestedt, G. L. Norddahl, G. Sten, A. Ugale, M.-A. Micha Frisk, R. Mattsson, T. Deierborg, M. Sigvardsson, D. Bryder. An epigenetic component of hematopoietic stem cell aging amenable to reprogramming into a young state. Blood, 2013; DOI: 10.1182/blood-2012-11-469080

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Source: http://feeds.sciencedaily.com/~r/sciencedaily/top_news/top_science/~3/YJJ0QkbuMwQ/130325093659.htm

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Windy weather disappointing in New England?s home opener

Foxborough--Weather conditions were a big factor in a scoreless tie between Sporting Kansas City and the New England Revolution Saturday afternoon in Foxborough.

Chances were at a minimum in a game that only saw eight shots spread?among?both teams. With a strong wind gust at Gillette Stadium, moving the ball proved to be a difficult task for both sides, as there was no control of any ball played in the air.

Revolution head coach Jay Heaps found that tactics almost went out the window, given the conditions.

?I don?t want to make excuses but I will say this, the wind was definitely difficult to play in,? Heaps said. ?You can see the ball moving, you could feel it. I think if you go do heat maps, it?s going to be split down the middle and it?s going to be all away from where the benches were because the wind was just pulling everything over there.

"It was hard to switch fields when we needed to change the point of attack.?

Sporting Kansas City coach Peter Vermes had a gameplan heading into the weekend, but found out ahead of the game that his team would certainly be battling the elements.

?Coming in during the week we wanted to play,? Vermes said. ?When we saw the weather getting worse and yesterday having practiced here, it was pretty simple that it was going to be a difficult game based on which way the wind was going.?

The game was a homecoming of sorts for Sporting Kansas City midfielder Benny Feilhaber, who played two seasons with the Revolution before being traded. Feilhaber held possession positively for spells in the first half but still found that the weather made play difficult for both teams.

?The wind really made the game impossible to play,? Feilhaber said. ?I think both teams realized that, so it was more like a field possession game.

"You just booted it down to one end and kind of pressed them. It wasn?t a pretty game by any means, but I think 0-0 is a fair result?

The lack of ball movement was further compounded by the high physical play all over the field, with 30 total fouls committed. Heaps singled out the resilant play of the Revolution back four was a big positive on an otherwise negative day.

?I think that, for me, Kansas City is one of the best teams at grinding out a game like that and I think that it showed a lot of our guys coming out and fighting them and making it a difficult battle,? Heaps exclaimed. ?I think our back four played well, but not just our back four, our entire midfield defended well. It?s one of those games where you want the three points.?

Source: http://us.rd.yahoo.com/sports/rss/sow/SIG=12t5r52ib/*http%3A//sports.yahoo.com/news/windy-weather-disappointing-england-home-024400105--mls.html

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Obamacare isn?t forever, but what?s next is worse (Powerlineblog)

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Why Predicting Comet Brightness Is So Tough

The newfound Comet ISON has the potential to be one of the brightest ever seen when it streaks through the inner solar system this November, but whether it will live up to the hype is anybody's guess.

Astronomers have a tough time forecasting the brightness of incoming comets. Ballyhooed "comet of the century" candidates sometimes fizzle out, as Kahoutek did in 1973, while some icy wanderers put on a surprisingly good show for skywatchers.

Why is it so difficult to predict comet behavior? For starters, comets are like snowflakes ? no two are alike.

Dirty snowballs

While comets have been called ?dirty snowballs,? recent observations by unmanned space probes suggest that they may not be too different from asteroids on the outside. Comets appear to have rocky surfaces which in most cases are probably not much more than several miles across. [Amazing Comet Photos of 2013]

What makes them much different from asteroids, however, is that frozen reservoirs icy material are hidden beneath the crust or contained in fissures and craters that pockmark the surface.?

Such comet "snow" is composed of ordinary water ice plus frozen ammonia and some other more exotic compounds, with dust grains of different sizes and compositions mixed in. These pools of volatile materials are called ?active regions.??

Because comets spend most of their time far out in space, billions of miles from the sun, the nucleus is completely stable, since it?s in a state of deep freeze where temperatures barely hover above absolute zero (minus 460 degrees Fahrenheit, or minus 273 degrees Celsius). ?

When a comet nears the sun, its frozen gases react to the increasing heat by vaporizing and expanding into a huge tenuous cloud around the nucleus called the coma. The nucleus and the coma make up the head of the comet, which may swell to more than 100,000 miles across.

It is sunlight that causes the comet's head to shine, in much the same manner that luminous paint reacts to ultraviolet light. The comet?s tail is produced by the solar wind ? a thin supersonic breeze of atomic particles blowing from the sun ? and the pressure of sunlight, which pushes the gas and dust out ahead of the coma.

Old versus new

One clue about how a comet will ultimately perform is whether it?s a ?new? comet, making its very first approach to the sun, or whether it?s an "old" one that has zoomed close to our star before.?

New comets might be covered with a load of very light, volatile material such as frozen nitrogen, carbon monoxide and carbon dioxide. Such ices can vaporize far from the sun, giving a distant comet a short-lived surge in brightness that can raise unrealistic expectations. This happened with ultimately disappointing comes such as Cunningham in 1940, Kohoutek 1973 and Austin in 1990.

But some new comets live up to the hype. In January 2007, for instance, Comet McNaught became the brightest comet in over 40 years, eventually becoming luminous enough to be visible in broad daylight.

Unpredictable!

Some small, faint comets have suddenly and unexpectedly become incredibly bright literally overnight. In October 2007, Comet Holmes brightened by a factor of 500,000 in less than two days, going from an object visible only with very large telescopes to becoming easily visible to the naked eye.?

Its sudden flare may have been causedby a buildup of gas inside the comet's nucleus that eventually broke through its surface, astronomers say. Incredibly, this all took place far out in space when the comet was nearly 230 million miles (370 million km) from the sun. Who knew?

Even recent skywatching sight Comet Pan-STARRS had some surprises in store. When the comet was discovered in June 2011, forecasts indicated it might get as bright as first or even zero magnitude ? in other words, as bright as the brightest stars.?

Then, it was surmised that the comet was "new" and might possibly lag behind the original optimistic predictions. Until recently, that seemed to be the case; Pan-STARRS was running about one-quarter as bright. Some suggested it might not get much brighter than third magnitude, which would be less than half as bright as Polaris, the North Star.?

Then without fanfare, in late February, it made a surprising comeback, reaching first magnitude as it rounded the sun on March 10.

Be careful!

While you might have gotten the idea by now that comets are notoriously bad actors and do not always follow their scripts, I should stress that many of them are well-behaved and do what is expected in a broad sense. Still, caution is advised when reading any predictions of their brightness.

That brings us back to Comet ISON, which is expected to sweep less than three-quarters of a million miles above the sun?s surface on Thanksgiving Day (Nov. 28). Already there have been a plethora of articles promoting ISON as the ?Comet of the Century.?

For an interesting analogy, baseball scouts like to catalogue the talents of players by looking at five general areas of performance in which one may define potential talent. Great ballplayers can hit for average, hit with power, field, run and throw. [Photos of Comet ISON in Night Sky]

Similarly, astronomers who catalogue potential great comets look at four general areas of performance: comets that closely approach the sun, closely approach the Earth, have a favorable projection angle for viewing the tail and high intrinsic brightness.?

From these criteria, Comet ISON certainly appears to be a ?can?t miss? prospect, though it is a new comet, which makes it more of a wild card.

But then again, like countless numbers of young ballplayers who had unlimited potential but failed to make the big leagues, ISON too could falter.?

It could unexpectedly exhaust all of its volatile material, leaving just a small, dark solid lump to ultimately swing around the sun ? meaning we may not see it all. Or perhaps upon passing through the sun?s outer atmosphere and being subjected to a temperature of around 1 million degrees Fahrenheit (555,000 degrees Celsius) or more, the comet nucleus might shatter or disintegrate.?

The saga of ISON is not yet fully written, and it could still go either way. We?ll keep track of its progress in the weeks and months to come.

In the meantime, it might be worth ending with an oft-quoted axiom by the legendary comet expert Fred Whipple: ?If you must bet, bet on a horse, not a comet!???

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for The?New York Times and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York.?Follow us?@Spacedotcom,?Facebook?or?Google+.?Originally published on?SPACE.com.

Copyright 2013 SPACE.com, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Source: http://news.yahoo.com/why-predicting-comet-brightness-tough-211112583.html

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Obama appeal to Israeli public means risk

President Barack Obama, left, listens to Israeli Prime Minister Benjamin Netanyahu during their visit to the Children's Memorial at the Yad Vashem Holocaust memorial in Jerusalem, Israel, Friday, March 22, 2013. (AP Photo/Pablo Martinez Monsivais)

President Barack Obama, left, listens to Israeli Prime Minister Benjamin Netanyahu during their visit to the Children's Memorial at the Yad Vashem Holocaust memorial in Jerusalem, Israel, Friday, March 22, 2013. (AP Photo/Pablo Martinez Monsivais)

President Barack Obama hugs Israeli Benjamin Netanyahu, as Israeli President Shimon Peres watches at left, before his departure at Ben Gurion International Airport in Tel Aviv, Israel, Friday, March 22, 2013, (AP Photo/Pablo Martinez Monsivais)

JERUSALEM (AP) ? In a landmark speech to young Israelis this week, the visiting U.S. President Barack Obama delivered an unorthodox appeal couched behind warm words of affinity for their country: Urge your leaders to change their ways and take bold new steps to reach peace with the Palestinians.

The message, potentially risking the ire of Israeli Prime Minister Benjamin Netanyahu, marked a gamble by the U.S. leader as he searches for ways to restart long-stalled Mideast peace efforts. With no breakthroughs coming out of the visit on the Palestinian front, Obama must now hope that the power of the presidency, combined with the goodwill he accumulated during the 48-hour visit, can persuade a still-skeptical Israeli leadership to abandon some deeply entrenched views and get negotiations moving again.

After a first term plagued by repeated run-ins with Netanyahu and perceptions among Israelis that he was cool to their cause and perhaps even hostile to their prime minister, Obama certainly succeeded in his goal of resetting the relationship. He was treated like a rock star in meetings with Israeli leaders and everyday people, and his every moment was followed by a fawning Israeli media.

"Israel is in Love," Yediot Ahronot, Israel's largest daily, wrote in a headline Friday.

Obama and Netanyahu, who have appeared uncomfortable together in the past, smiled, joked and exchanged pleasant small talk throughout the visit, with much of the conversation caught on live microphones permitted to join them. Netanyahu seemed almost giddy at times.

But hidden behind the public displays of affection, Obama delivered a powerful message. In the keynote address to Israeli young adults, he implored the gathering to press their leaders to take risks for peace.

He also had some tough words for his audience, criticizing Israeli settlements as "counterproductive" and speaking movingly of Palestinians suffering under Israeli military occupation.

"Let me say this as a politician. I can promise you this. Political leaders will never take risks if the people do not push them to take some risks," he said. "Ordinary people can accomplish extraordinary things."

While addressed at the Israeli public, the nationally broadcast speech was also aimed at Netanyahu. On the most public of stages, Obama embraced the key argument of Israel's left wing: that the status quo, in which Israel controls millions of disenfranchised Palestinians, is unsustainable and that making concessions for peace is good not only for the Palestinians, but vitally needed for Israel itself to be able to survive.

Obama's speech, even the lines most critical of Israel, was repeatedly interrupted by applause from the preselected audience largely comprised of university students. Perhaps the loudest ovation came when he called for the establishment of a Palestinian state.

"The speech gave young people a new spirit to push for a two-state solution," said Isaac Shickman, a 24-year-old Jerusalem university student who was in the audience. "It made me think of what I can do to promote peace and change in the country and the region."

Handled improperly, Obama's gambit might have backfired. Early on in his presidency, Obama's public criticism of Israeli settlements in the West Bank and east Jerusalem raised tensions with Israel and contributed to more than four years of deadlock in peace efforts.

The Palestinians claim both areas, captured by Israel in the 1967 Mideast war, for their future state and have refused to negotiate while Israel continues to expand its settlements there.

Julian Zelizer, a historian at Princeton University, said Thursday's speech came straight out of Obama's playbook back home.

"This was President Obama using some of the tactics that he uses here, meaning trying to speak directly to the people to pressure the leaders to do something, rather than focusing on the leaders themselves," he said.

He said the tactic risked antagonizing Netanyahu, but that Obama deftly handled the visit. Obama's warm words for Israel, his repeated pledges to Israeli security, a visit to the Yad Vashem Holocaust memorial and the many joint interests of the two countries all helped blunt potential criticism.

"It's a successful speech, but it's a far cry from solving the problem," he said.

In a statement, Netanyahu's office said he "shares President Obama's view regarding the need to advance a peace that ensures the security of Israel's citizens." It would not comment on Obama's appeals to the public.

Israelis themselves were divided over the significance of the speech.

"It was a seminal speech, even an historic one," wrote Shalom Yerushalmi, a commentator in the Maariv daily. "Will it work? Who knows?"

Tzipi Livni, the leader of a small dovish political party who is Netanyahu's new chief negotiator, said she hoped Obama's message would rally more Israelis to the country's peace camp.

"I would be very happy if Israeli citizens who heard him were convinced that this is what needs to be done," she said.

But Naftali Bennett, a Cabinet minister who leads a pro-settler party, rejected the speech. "A Palestinian state is not the right way," he wrote on his Facebook page.

Such divisions in the Cabinet are a key reason why it seems unlikely that Netanyahu will make any bold new concessions to restart talks. U.S. Secretary of State John Kerry is expected back in Israel on Saturday night to discuss the matter.

During the trip, Obama also had some tough words for the Palestinians. While criticizing Jewish settlements, Obama told the Palestinians to stop using the issue as an "excuse" to do nothing and stressed that disagreements can be resolved only through negotiations.

Hanan Ashrawi, a senior Palestinian official, said she found Obama's visit disappointing, but not surprising.

"I think the purpose of the visit, clearly, was to show support and identification with Israel," she said.

"The question has to be answered by the Americans, and the international community. How are they going to proceed from here?" she said. "It's not enough to say Kerry will be here frequently."

American presidents have a long history of using their position to cajole foreign audiences.

"I think presidents rightly see it as part of their duty," said political historian Evan Cornog, dean of the School of Communication at Hofstra University in Hempstead, New York. "The U.S. is a nation of ideas."

In 1963, John F. Kennedy paid a historic visit to a divided Berlin to show solidarity with the people of West Germany. A quarter of a century later, Ronald Reagan famously urged Soviet leader Mikhail Gorbachev to "tear down" the Berlin Wall.

More recently, George W. Bush spoke of spreading democracy in the Middle East and turning Iraq into a model democracy. Early in his term, Obama traveled to Cairo in hopes of ushering in a new era of relations with the Muslim world.

Historians have debated whether these speeches led to changes, such as the collapse of communism or the rise of the Arab Spring, or whether they were simply signs of the times.

Cornog said assessing the impact of a president's words is hard to quantify but that Obama's appeal could play a role in swaying Israeli public opinion, particularly by bolstering the Israeli left.

"I certainly think the bully pulpit, that ability of the president to have an audience and to put forth arguments, it does mean something," he said.

Associated Press

Source: http://hosted2.ap.org/APDEFAULT/cae69a7523db45408eeb2b3a98c0c9c5/Article_2013-03-22-ML-Israel-Obama-Appeal/id-032530a6e8134d9ca87b1fed04b92d86

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Two teen suspects arrested in shooting death of Georgia baby

Terry Dickson / The Morning News via AP

Authorities investigate the scene of shooting in Brunswick, Ga., on Thursday.

By Elizabeth Chuck, Staff Writer, NBC News

Updated at 4:30 p.m. ET: Two?teenage suspects were arrested in a small coastal Georgia city?a day after a baby was killed and his mom shot, authorities said Friday.

The mother, Sherry West,?told FOX affiliate WAWS-TV?that she was pushing her 13-month-old son, Antonio, in his stroller in Brunswick, Ga., Thursday morning, when?two boys ? described as about 10 and 15 years old ? came up, demanded money and shot them.

Brunswick police announced Friday afternoon that they had arrested a 17-year-old and a 14-year-old, and that they were charging them with murder. The arrests came after SWAT teams had gone door to door, searching for clues, and police had checked local school attendance and absentee lists to see if there were any students who hadn't been at school that fit the description of the suspects.

West told WAWS-TV that the older boy pointed a handgun at her during the encounter Thursday.

"He said, 'I'm gonna kill you if you don't give me your money,' and I said, 'I swear I don't have any,'" she told WAWS-TV of the encounter.?

She said they wouldn't accept no for an answer.

"He says, 'Well, I'm gonna kill your baby,'" she told WAWS-TV, crying. "I put my arms over my baby and he shoves me. And then he shot my baby right in the head."?

West was shot in the leg, according to local reports. Brunswick police spokesman Todd Rhodes confirmed she received a non-life-threatening gunshot wound from a handgun.

West was the only eyewitness to the crime, Rhodes said.?Residents in the area reported hearing gunshots, but didn't see anything, he said.?

Brunswick, Georgia Police Chief Tobe Green says authorities have arrested two teenagers suspected in the shooting death of a baby in a stroller and the wounding of the baby's mother.

"We're not leaving any stone unturned," he said earlier in the day.

In a news conference Friday afternoon, Brunswick police chief Tobe Brown said, "We're still following leads from our witnesses. We're still collecting evidence. ... We're currently serving search warrants at three locations within the city."?

Police hadn't located a weapon yet.

The baby's father, Louis Santiago, said to WAWS-TV, "Why? Why my little one? You know? You feel they could have just taken the pocketbook and go."

Brunswick is about 80 miles south of Savannah.

This story was originally published on Fri Mar 22, 2013 9:56 AM EDT

Source: http://feeds.nbcnews.com/c/35002/f/653381/s/29e32553/l/0Lusnews0Bnbcnews0N0C0Inews0C20A130C0A30C220C174148320Etwo0Eteen0Esuspects0Earrested0Ein0Eshooting0Edeath0Eof0Egeorgia0Ebaby0Dlite/story01.htm

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