In lab, Pannexin1 restores tight binding of cells that is lost in cancer

Monday, January 30, 2012

First there is the tumor and then there's the horrible question of whether the cancerous cells will spread. Scientists increasingly believe that the structural properties of the tumor itself, such as how tightly the tumor cells are packed together, play a decisive role in the progression of the disease. In a new study, researchers show that the protein Pannexin1, known to have tumor-suppressive properties, plays an important role in keeping the cells within a tissue closely packed together, an effect that may be lost with cancer.

"In healthy tissues, the recently discovered protein Pannexin1 may be playing an important role in upholding the mechanical integrity of the tissue," said first author and Brown University M.D./Ph.D. student Brian Bao. "When we develop cancer, we lose Pannexin1 and we lose this integrity."

The results appeared in advance online in the Journal of Biological Chemistry on Jan. 20.

To conduct their research, the group at Brown University and the University of British Columbia employed a "3-D Petri dish" technology that allows investigators to watch closely how cells interact with each other, without scientists having to worry about additional interactions with surrounding scaffolding or the culture plate itself. How readily the cells form large multicellular structures therefore reflects their interactions with each other, not their in vitro surroundings.

Bao's advisor, Jeffrey Morgan, associate professor of medical science, developed the 3-D Petri dish technology. Morgan is the paper's senior author.

Cancer cells converge

Starting with rat "C6" glioma (brain tumor) cells that do not express Pannexin1, the researchers left some unaltered and engineered others to express Pannexin1. After putting the different cells into the 3-D Petri dishes and watching them interact for 24 hours, they saw that the Pannexin1 cells were able to form large multicellular tissues much faster and more tightly than the unaltered cancer cells.

To confirm that Pannexin1 was indeed causing these changes, Bao and his colleagues treated their samples with the drugs Probenecid and Carbenoxolone, which are well known inhibitors of Pannexin1. They saw that sure enough, the drugs negated Pannexin1's accelerating effect.

Then the team was ready to achieve the the study's main aim, Bao said, namely to determine how Pannexin1 was able to drive these cells to clump together faster and tighter. They found that Pannexin1 sets off a chain reaction involving the energy-carrying molecule ATP and specific receptors for it.

When all experiments were done, Bao, Morgan, and their collaborators had found that as soon as the cells touched each other, Pannexin1 channels were stimulated to open and release ATP. The ATP then bound to cell surface receptors, kicking off intracellular calcium waves that ultimately remodeled the network of a structural protein called actin. This remodeling increases the forces between the cells, driving them to bind together more tightly.

Figuring out that sequence, and Pannexin1's role in it, is perhaps the study's biggest contribution to cancer research, Bao said.

"Using their single-cell systems, others have been able to carefully study individual pieces of this cascade," he said. "We came from a different perspective. Because the strength of our assay is that we can look at gross multicellular behavior in 3-D, we could ask, 'Does this actually manifest into something tangible on the multicellular level?'"

Having gained this understanding of Pannexin1's role in the mechanics of tumors, Bao is now engaged in research to answer the obvious next questions: Does Pannexin1 affect the tumor's ability to spread and invade? When cancerous cells regain Pannexin1 expression, are they less likely to spread and leave the tumor?

###

Brown University: http://www.brown.edu/Administration/News_Bureau

Thanks to Brown University for this article.

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Source: http://www.labspaces.net/117181/In_lab__Pannexin__restores_tight_binding_of_cells_that_is_lost_in_cancer

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Mitt Riffs Hard on Newt (TIME)

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Public spending fuels Ecuador leader's popularity (AP)

QUITO, Ecuador ? Amparo Martinez's universe is two small, tidy rooms in a poor Quito neighborhood that she shares with her 83-year-old mother and a severely handicapped daughter.

Her predicament makes holding a job impossible, so the three depend on a $240-a-month government stipend introduced by President Rafael Correa under a program for the disabled.

Martinez adores Correa.

"I hope he's re-elected many times," she says.

Correa is regularly assailed by human rights, press freedom and business groups as intemperate, autocratic and intolerant of dissent. Yet he is popular among millions of Ecuadoreans for programs which, like the initiative for the disabled, have improved their lives.

An array of state-funded programs implemented or broadened since Correa's 2006 election have brought stability to this traditionally unruly South American nation that previously churned through six presidents in 10 years.

A doubling in public spending under Correa adheres to a formula that has also aided the political longevity of his leftist allies Presidents Hugo Chavez of Venezuela, Cristina Fernandez of Argentina and Evo Morales of Bolivia.

But Ecuador devotes a greater share of its economy to public investment than any other nation in Latin America and the Caribbean, spending 10 percent of gross domestic product.

The main strategic ally of this tall, pugnacious U.S.- and European-trained economist has been the high price of oil, currently at $99.50 per barrel, which helped fuel 8.9 percent economic growth last year. Oil accounts for about a third of government revenues in this OPEC member nation.

Straying from Latin American custom, Correa has also engineered a vertiginous rise in income tax collection, boosting compliance by businesses and professionals. From $4.9 billion in 2007, income tax receipts rose to $8.4 billion last year.

He has exhibited uncanny resolve in coaxing higher numbers into the revenue columns of the balance sheet in a country that made the U.S. dollar its national currency in 2000.

That included rewriting oil extraction contracts with multinationals to radically boost the state's share of windfall profits. Some multinationals left, others stayed.

The government is now on the verge of reaping more raw material royalties. It is set to shortly sign contracts designed to yield the state $3 billion annually from the mining of gold, copper and other metals.

Correa has been coy on whether he'll run for re-election in balloting that could come as early as a year from now. If voting were held today, he'd be difficult to beat. Never in five years in office has Correa's approval rating dipped below 50 percent. It currently stands around 70 percent.

Critics accuse Correa of building castles in the air by creating expectations on the uncertain promise of continued high oil prices. If oil drops below $73 a barrel, they say, his ambitious public spending will need to be curbed.

"It's not sustainable as an economic model over time," said Xavier Ordenana, an economist with the Escuela Politecnica del Litoral in Guayaquil. "It can last for some years but not forever."

Ordenana says the government realizes the private sector must also grow or it risks insolvency. Heavy industry, export-oriented manufacturing and high-tech work remain scarce in Ecuador.

In all, 5 million of Ecuador's total population of 14 million have personally benefited in some measure from government largesse, researchers at the FLACSO graduate school calculate. Under Correa, the state has built homes for 30,000 families, plowed $8.5 billion into education and $5.3 billion into health care. It has rebuilt or improved nearly 3,400 miles (5,500 kilometers) of roads, nearly two-thirds of Ecuador's highway system, spending $4.5 billion.

Other programs have zeroed in on helping individuals and families.

The government says the program for the disabled, a flagship Correa initiative, has benefited 300,000 people. They receive medical attention, welfare payments and equipment including wheelchairs. Some have even been given housing. Public wheelchair access is improving.

Another popular program provides a $35 monthly boost to 1.6 million poor people, chiefly homemakers with no other formal income.

"My husband died many years ago but now I have the president as a spouse because he gives me a little money every month," said Maria Pillajo, a stooped 67-year-old who scrapes by washing clothes and loading baskets in the market of Quito's poor southern district of El Camal.

"Until poverty is eliminated it's a good measure," Correa said of the program when asked about it during a recent meeting with foreign correspondents. The government says the poverty rate stands at 29 percent, down nine percentage points from when Correa took office. Meanwhile, unemployment is officially at 5.1 percent.

It's not just the poor for whom the government is writing checks.

Some 100,000 middle-class first-time home buyers have received a $5,000 one-time "housing subsidy" grant that enable them to afford down payments.

"The payments have a direct bearing on the president's image. In political terms, they have the excellent effect of sustaining his political project," said Simon Pachano, a FLACSO political scientist.

Correa has also plowed millions into education, giving free uniforms to a million students, texts to 3 million and regularly feeding 1.6 million breakfast.

"It's a great relief because sometimes we just don't have the money," said Francisco Carvajal, a 28-year-old father of three who said he earns $750 a month from his job as a construction material sales company.

His children got free uniforms and texts as well as English and computing classes free of charge.

Correa is far from Ecuador's first populist leader. Yet he has been hounded by none of the accusations of corruption that drove previous presidents from office.

His popularity is anything but universal, however.

In striving for what he and Chavez call "21st-century socialism," Correa has alienated bankers, industrialists, the Roman Catholic Church and even indigenous groups. Initially backing him, the latter now object to his insistence that the state can extract minerals from their traditional lands without their consent.

Many business leaders are angry with Correa over his chumminess with Iran, fearing that he is distancing Ecuador from Washington, still the country's top trading partner.

On no adversary has Correa unleashed such bile as on the opposition news media, which he claims "oligarchs" have used to seek to discredit him.

Correa has had a columnist and three directors of the opposition newspaper El Universo successfully prosecuted for criminal defamation. They have been sentenced to three years in prison each and a collective total of $40 million in fines, though the sentence is on appeal.

Human Rights Watch has decried how Correa used a May referendum to obtain a popular mandate for reforms that could "constrain media and influence the appointment and dismissal of judges."

It also complained that people involved in protests where violence occurs "may be prosecuted on inflated and inappropriate terrorism charges."

___

Associated Press Writer Frank Bajak contributed to this report from Lima, Peru.

Source: http://us.rd.yahoo.com/dailynews/rss/latam/*http%3A//news.yahoo.com/s/ap/20120125/ap_on_re_la_am_ca/lt_ecuador_correa_s_popularity

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Climbing higher at German wind farm

A German wind farm offers a ropes course at the foot of a towering wind turbine, providing an alternative view of green energy.

? A local, slice-of-life story from a Monitor correspondent.

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Welcome to the world?s first ropes course ever installed on a wind farm. Built by the Juwi Group, one of Germany?s leading renewable-energy companies, and located at the foot of one of the farm?s 10 towering wind turbines, it?s attracting tourists in droves.

Why would a green company also build a climbing ropes course?

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?We wanted to make the windmills more inviting,? says Ricarda Schuller, a spokesperson for Juwi. As interest in green energy use grows, the interactive course could help provide an alternative view of wind farms, which are often criticized here for being eyesores.

The course also fits into the company?s overall philosophy of providing attractive services to its employees: In addition to the ropes course, Juwi has a kindergarten, a swimming pool, and a beach volleyball court.

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Arab committee wants extended Syria mission: sources (Reuters)

CAIRO (Reuters) ? An Arab League committee on Syria will ask Arab foreign ministers on Sunday to extend a monitoring mission in the country by one month, sources attending the committee meeting said.

Hundreds of Syrians have been killed since the mission began its work in late December and political opponents of President Bashar al-Assad are demanding the League refer Syria to the United Nations Security Council.

"The committee will recommend an expansion of the monitoring mission for an extra month," said one source attending the committee meeting in Cairo who asked not to be named. The decision was confirmed by a second source at the meeting.

The foreign ministers are due to meet later on Sunday to debate the committee's conclusions on the mission, whose mandate expired on Thursday, and will have the final word on whether to extend, withdraw or strengthen it.

Arab states are divided over how to handle the crisis in Syria and critics say the monitoring mission is handing Assad more time to kill opponents of his rule.

Some want to crank up pressure on Assad to end a 10-month-old crackdown on a popular revolt in which, according to the United Nations, more than 5,000 people have died. Syria says 2,000 security personnel have been killed in the violence.

Others worry that weakening Assad could tip Syria, with its potent mix of religious and ethnic allegiances, into a deeper conflict that would destabilize the entire region. Some may fear the threat from their own populations if he were toppled.

Two representatives of Arab states told Reuters some small disagreements needed to be ironed out by the five-nation Syria committee on the phrasing of its final report but there was broad agreement on the outlines.

"The differences were mainly on the phrasing of the evaluations and recommendations ... but we managed to agree on most of those points and on how to reach agreement on the remaining part," one said.

The opposition Syrian National Council (SNC) says the observers lack the resources and clout to truly judge Assad's compliance with an Arab peace plan Syria signed up to in November and has called upon the Arab League to refer the Syrian crisis to the Security Council.

But Egypt, Algeria and Tunisia told the head of the Arab League, Nabil Elaraby, they would oppose such a move, a League source said on Sunday.

"The three states support solving the Syrian crisis inside the Arab League," the source told Reuters.

FUNERAL PROCESSION

Two Syrian army officers, an infantryman, a rebel and two civilians died in clashes on Sunday in Talfita, a village in the Damascus region, said the Syrian Observatory for Human Rights.

Intermittent fighting continued in the town of Douma, nine miles northwest of the capital, which had been encircled by the military, said the UK-based rights group.

An opposition activist and a rebel fighter in Douma told Reuters by telephone the fighting had eased and the rebels held about two thirds of its main streets.

Masked fighters had set up checkpoints and a funeral procession for five civilians killed on Saturday was passing through the town, they said. Angry cries could be heard in the background as they spoke.

The rebel fighter said there were several casualties on Sunday but no confirmed deaths.

The head of the monitoring effort, Sudanese General Mohammed al-Dabi, was presenting his findings to the League's Syria committee and the foreign ministers of the 22-member regional body will decide their response later on Sunday.

Maintaining the 165 monitors, and perhaps giving them a broader remit, could give Arab states more time to find a way out of the crisis.

Elaraby met several Arab officials on Saturday and another source close to the League said the ministers could decide both to extend the mission and to offer it additional support in the form of U.N. or military experts.

Qatar and Saudi Arabia, regional rivals of Syria and its ally Iran, are impatient for decisive action against Assad, and Qatar has suggested sending Arab troops to Syria.

The League is due to discuss the idea but military action against Assad would need unanimous backing and several countries still believe in a negotiated solution, League sources say.

The Security Council is also split on how to address the crisis, with Western powers demanding tougher sanctions and a weapons embargo, and Assad's ally Russia preferring to leave the Arabs to negotiate a peaceful outcome.

Suggestions to send in U.N. experts to support the Arab observers made little headway at the last meeting earlier this month and Damascus has said it would accept an extension of the observer mission but not an expansion in its scope.

Syria, keen to avoid tougher foreign action, has tried to show it is complying with the Arab peace plan, which demanded a halt to killings, a military pullout from the streets, the release of detainees, access for the monitors and the media, and a political dialogue with opposition groups.

This month the Syrian authorities have freed hundreds of detainees, announced an amnesty, struck a ceasefire deal with armed rebels in one town, allowed the Arab observers into some troublespots and admitted some foreign journalists.

Assad also promised political reforms, while vowing iron-fisted treatment of the "terrorists" trying to topple him.

(Additional reporting by Erika Solomon in Beirut and Lin Noueihed in Cairo; Writing by Tom Pfeiffer; Editing by Diana Abdallah)

Source: http://us.rd.yahoo.com/dailynews/rss/world/*http%3A//news.yahoo.com/s/nm/20120122/wl_nm/us_syria

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Nano Patents and Innovations: Why Do We Sleep With Our Pets And ...

In the U.S., it's perfectly normal to sleep with your dog or cat, but huge cultural battles are being fought over whether it's odd, or even detrimental, to sleep with your baby. In much of the developing world, people think just the opposite, says anthropologist Carol Worthman.?

iStockphoto.com

Emory anthropologist Carol Worthman first began thinking about the cultures of sleep while traveling across Kenya in 1979 as a postdoctoral fellow. She was headed to the coast in an old, classic train with wooden slats that rolled down over the windows. The cheap ticket section was so packed for the overnight journey that mothers and children shared bunks in the women?s section.

?Children were crying. It was really noisy and I couldn?t get comfortable. I didn?t sleep much at all,? Worthman says.

The locals, however, took it in stride. ?In the morning, everyone around me got up looking bright and beaming,? Worthman says. ?I thought, ?They don?t sleep like Westerners do.??

iStockphoto.com

Nearly two decades later, Worthman was asked by a pediatrician to sum up what anthropologists know about sleep. She thought about it and had to respond, ?Not much.? While most waking moments of human activity were well-documented, their sleeping ones were largely ignored by anthropologists.

?When people go to sleep is when we can finally write up our notes,? Worthman jokes.

But the realization that her field had overlooked one-third of human life spurred her to work on the first analytic framework for comparative studies of human sleep behavior in 1998.

iStockphoto.com

She pored over the literature, and interviewed field researchers about their observations of the ecology of sleep from across continents, cultures and climates in the developing world. From foragers to farmers, islanders to mountain dwellers, patterns of sleep behavior began to emerge.

?I was startled,? Worthman says. ?You learn just how weird our sleeping habits are in the United States.?

For instance, many Americans consider it odd, and perhaps detrimental, to sleep with a newborn baby. And yet it?s perfectly normal to sleep with a dog or cat.

?In much of the developing world, people think just the opposite,? Worthman says. ?It?s pretty much universal that babies don?t sleep alone. They either lie right next to their mothers, or nearby on a mat, or in a cradle or a sling.?

Putting a baby in a separate room to sleep would be viewed as tantamount to child abuse in many cultures, Worthman says.

Credit: iStockphoto.com

For much of human history, humans have slept in family groups, with one ear cocked for danger. They were comforted by the sounds of their livestock shuffling, their babies breathing and the crackle of a smoky fire to ward off bugs and larger predators. ?Sleeping like a log? is not so desirable if you could roll into the fire, or miss the sound of an approaching predator.

Worthman?s work has shown that rural, and even some urban, communities of the developing world have markedly different sleeping patterns than the typical American. ?You can actually quantitatively show that culture drives human sleep behavior,? she says.

Building on her decades of research, Worthman is about to launch the first quantitative study of a pre-electric sleep culture, a major experiment set to begin soon in rural Vietnam. Click here to read more about the study.

It?s only relatively recently that electricity, larger homes, box springs, non-allergenic mattresses and climate-controlled interiors have altered our sleep environments. This rapid shift leads Worthman to wonder if modern sleep practices have set us up for chronic problems such as insomnia, sleep apnea and parental anxiety over a newborn?s sleep patterns.

Photo by Klaus Roesch

For instance, in many cultures, people tend to take more naps and have less rigid expectations for sleeping straight through the night. Some evidence indicates that in pre-gaslight Europe, it was not uncommon for people to have an early evening sleep, then wake up later in the night for a while, before returning to a deeper sleep state.

Modern-day insomniacs may actually be the more normal ones, Worthman notes. ?In our culture, we have this very fixed idea that you should lie down and go out like a light,? she says. ?One of the problems with insomnia is that people become very anxious about it. If they relaxed, went with the flow, and perhaps took a nap during the day, maybe it would help.?

All images, , unless otherwise noted.

Contacts and sources:
Story by Carol Clark?

Source: http://nanopatentsandinnovations.blogspot.com/2012/01/why-do-we-sleep-with-our-pets-and-not.html

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