Home Tags Posts tagged with "proceedings of the national academy"

proceedings of the national academy

0

British experts have found that vitamin D could help the body fight infections of deadly tuberculosis.

Nearly 1.5 million people are killed by the infection every year and there are concerns some cases are becoming untreatable.

A study in Proceedings of the National Academy of Sciences showed patients recovered more quickly when given both the vitamin and antibiotics.

More tests would be needed before it could be given to patients routinely.

British experts have found that vitamin D could help the body fight infections of deadly tuberculosis

British experts have found that vitamin D could help the body fight infections of deadly tuberculosis

The idea of using vitamin D, also known as sunshine vitamin, to treat tuberculosis (TB) harks back to some of the earliest treatments for the lung infection.

Before antibiotics were discovered, TB patients were prescribed “forced sunbathing”, known as heliotherapy, which increased vitamin D production.

However, the treatment disappeared when antibiotics proved successful at treating the disease.

This study on 95 patients, conducted at hospitals across London, combined antibiotics with vitamin D pills.

It showed that recovery was almost two weeks faster when vitamin D was added. Patients who stuck to the regimen cleared the infection in 23 days on average, while it took patients 36 days if they were given antibiotics and a dummy sugar pill.

Dr. Adrian Martineau, from Queen Mary University of London, said: “This isn’t going to replace antibiotics, but it may be a useful extra weapon.

“It looks promising, but we need slightly stronger evidence.”

Trials in more patients, as well as studies looking at the best dose and if different forms of vitamin D are better, will be needed before the vitamin could be used by doctors.

Vitamin D appears to work by calming inflammation during the infection. An inflammatory response is an important part of the body’s response to infection.

During TB infection, it breaks down some of the scaffolding in the lungs letting more infection-fighting white blood cells in. However, this also creates tiny cavities in the lungs in which TB bacteria can camp out.

“If we can help these cavities to heal more quickly, then patients should be infectious for a shorter period of time, and they may also suffer less lung damage,” Dr. Adrian Martineau said.

The doctors suggested this might also help in other lung diseases such as pneumonia and sepsis.

One in three people have low levels of tuberculosis bacteria in their lungs and have no symptoms, known as latent tuberculosis. However, this would turn to full blown TB in about 10% of people.

 

US scientists have found that children with older fathers and grandfathers appear to be “genetically programmed” to live longer.

The genetic make-up of sperm changes as a man ages and develops DNA code that favors a longer life – a trait he then passes to his children.

The team found the link after analyzing the DNA of 1,779 young adults.

Their work appears in Proceedings of the National Academy of Sciences.

Experts have known for some time that lifespan is linked to the length of structures known as telomeres that sit at the end of the chromosomes that house our genetic code, DNA. Generally, a shorter telomere length means a shorter life expectancy.

Like the plastic tips on shoelaces, telomeres protect chromosomal ends from damage. But in most cells, they shorten with age until the cells are no longer able to replicate.

US scientists have found that children with older fathers and grandfathers appear to be "genetically programmed" to live longer

US scientists have found that children with older fathers and grandfathers appear to be "genetically programmed" to live longer

However, scientists have discovered that in sperm, telomeres lengthen with age.

And since men pass on their DNA to their children via sperm, these long telomeres can be inherited by the next generation.

Dr. Dan Eisenberg and colleagues from the Department of Anthropology at Northwestern University studied telomere inheritance in a group of young people living in the Philippines.

Telomeres, measured in blood samples, were longer in individuals whose father’s were older when they were born.

The telomere lengthening seen with each year that the men delayed fatherhood was equal to the yearly shortening of telomere length that occurs in middle-aged adults.

Telomere lengthening was even greater if the child’s paternal grandfather had also been older when he became a father.

Although delaying fatherhood increases the risk of miscarriage, the researchers believe there may be long-term health benefits.

Inheriting longer telomeres will be particularly beneficial for tissues and biological functions that involve rapid cell growth and turnover – such as the immune system, gut and skin – the scientists believe.

And it could have significant implications for general population health.

“As paternal ancestors delay reproduction, longer telomere length will be passed to offspring, which could allow life span to be extended as populations survive to reproduce at older ages.”

It might be possible that the advantage of receiving long telomeres from an old father is more then set off by the disadvantage of higher levels of general DNA damage and mutations in sperm, he said.

 

An increasing population of huge pythons, many of them pets that were turned loose by their owners when they got too big, appears to be wiping out large numbers of raccoons, opossums, bobcats and other mammals in Everglades, Florida, a study says.

The study, which was published Monday in the Proceedings of the National Academy of Sciences, found that sightings of medium-size mammals are down dramatically (as much as 99%, in some cases) in areas where pythons and other large, non-native constrictor snakes are known to be lurking.

Scientists fear the pythons could disrupt the food chain and upset the Everglades’ environmental balance in ways difficult to predict.

“The effects of declining mammal populations on the overall Everglades ecosystem, which extends well beyond the national park boundaries, are likely profound,” said John Willson, a research scientist at Virginia Tech University and co-author of the study.

Tens of thousands of Burmese pythons, which are native to Southeast Asia, are believed to be living in the Everglades, where they thrive in the warm, humid climate.

While many were apparently released by their owners, others may have escaped from pet shops during Hurricane Andrew in 1992 and have been reproducing ever since.

Burmese pythons can grow to be 26 feet long and more than 200 pounds, and they have been known to swallow animals as large as alligators. They and other constrictor snakes kill their prey by coiling around it and suffocating it.

The National Park Service has counted 1,825 Burmese pythons that have been caught in and around Everglades National Park since 2000. Among the largest so far was a 156-pound, 16.4-foot one captured earlier this month.

For the study, researchers drove 39,000 miles along Everglades-area roads from 2003 through 2011, counting wildlife spotted along the way and comparing the results with surveys conducted on the same routes in 1996 and 1997.

The National Park Service has counted 1,825 Burmese pythons that have been caught in and around Everglades National Park since 2000

The National Park Service has counted 1,825 Burmese pythons that have been caught in and around Everglades National Park since 2000

The researchers found staggering declines in animal sightings: a drop of 99.3% among raccoons, 98.9% for opossums, 94.1% for white-tailed deer and 87.5% for bobcats. Along roads where python populations are believed to be smaller, declines were lower but still notable.

Rabbits and foxes, which were commonly spotted in 1996 and 1997, were not seen at all in the later counts. Researchers noted slight increases in coyotes, Florida panthers, rodents and other mammals, but discounted that finding because so few were spotted overall.

“The magnitude of these declines underscores the apparent incredible density of pythons in Everglades National Park,” said Michael Dorcas, a professor at Davidson College in North Carolina and lead author of the study.

Although scientists cannot definitively say the pythons are killing off the mammals, the snakes are the prime suspect. The increase in pythons coincides with the mammals’ decrease, and the decline appears to grow in magnitude with the size of the snakes’ population in an area.

A single disease appears unlikely to be the cause since several species were affected.

The report says the effect on the overall ecosystem is hard to predict. Declines among bobcats and foxes, which eat rabbits, could be linked to pythons’ feasting on rabbits. On the flip side, declines among raccoons, which eat eggs, may help some turtles, crocodiles and birds.

Scientists point with concern to what happened in Guam, where the invasive brown tree snake has killed off birds, bats and lizards that pollinated trees and flowers and dispersed seeds. That has led to declines in native trees, fish-eating birds and certain plants.

In 2010, Florida banned private ownership of Burmese pythons. Earlier this month, U.S. Interior Secretary Ken Salazar announced a federal ban on the import of Burmese pythons and three other snakes.

Ken Salazar said Monday that the study shows why such restrictions were needed.

“This study paints a stark picture of the real damage that Burmese pythons are causing to native wildlife and the Florida economy,” he said.

[youtube 9ntM1V7XcKA]

[youtube cKCKXAkYkbI]