LATEST SCIENTIFIC DISCOVERIES: 2013-10-06

Saturday, 12 October 2013

Risk of early death from smoking more severe than thought, Australian study reveals

The risk of premature death from smoking is much more severe than previously thought for both light and heavy smokers, a large Australian study has revealed.

The study found that two thirds of deaths in current smokers can be attributed to tobacco use.

Professor Emily Banks from the Australian National University led the study, which followed 200,000 people over four years.

"The international rule of thumb is that half of all smoker deaths are directly caused by tobacco," she said.

"We found that [over the four years] people who are current smokers were three times more likely to die than people who had never smoked, and their life expectancy within that four-year period was diminished by 10 years compared to the never-smokers."

Key points:

Study followed 200,000 people over four years
Two thirds of deaths in current smokers can be attributed to tobacco use
Smoking reduces life expectancy by 10 years
Light smokers also face double risk of early death

Professor Banks is also the scientific director of the Sax Institute's 45 and Up study, which collected the data on the health of 10 per cent of New South Wales residents.

International research has long confirmed the connection between tobacco smoking and premature death from heart problems and lung cancer.

Tobacco smoking is estimated to be responsible for 9.7 per cent of the total disease burden, but until now large-scale Australian data has not been available.

Professor Banks says the effect that smoking has on the population depends on the intensity of smoking and how long people have been smoking.

"So in a way we need our data for our epidemic, and this is the first time that we have had data from the Australian population," she said.

She says the death rate matches patterns in the Britain and the United States.

"When people have been smoking for decades having started smoking in their late teens, and actually smoking heavily ... it's the pattern you see with a mature epidemic," she said

News also bad for 'light' smokers

Similarly, the news is not good for people who think of themselves as light smokers.

"The risk associated with smoking 10 cigarettes a day are similar to the risks of death associated with being morbidly obese, so with having a body mass index of 35 or more," Professor Banks said

"Most light smokers wouldn't think of themselves as having a risk that is similar to someone who is morbidly obese."

While the study did find it is better to be a light smoker than a heavy smoker, it did confirm that giving up improves health.

"On average smokers reduce their life expectancy by 10 years," Professor Banks said.

"Quitting at any age reduces the risks and the earlier, the younger you quit the better."

People who had cancer and heart disease were eliminated at the start and there were adjustments for alcohol, socio-economic factors, weight and age.

The preliminary data is to be presented to the 10th annual 45 and Up Collaborators meeting in Sydney on Friday

Professor Banks says the next step in the research is the basic building block to apply to the general Australian population to find more exactly how many deaths can be attributed to smoking.

By Nonee Walsh via www.abc.net.au

Friday, 11 October 2013

Iowa grants gun permits to the blind

Iowa is granting permits to acquire or carry guns in public to people who are legally or completely blind.

No one questions the legality of the permits. State law does not allow sheriffs to deny an Iowan the right to carry a weapon based on physical ability.

The quandary centers squarely on public safety. Advocates for the disabled and Iowa law enforcement officers disagree over whether it's a good idea for visually disabled Iowans to have weapons.

On one side: People such as Cedar County Sheriff Warren Wethington, who demonstrated for The Des Moines Register how blind people can be taught to shoot guns. And Jane Hudson, executive director of Disability Rights Iowa, who says blocking visually impaired people from the right to obtain weapon permits would violate the Americans with Disabilities Act. That federal law generally prohibits different treatment based on disabilities

On the other side: People such as Dubuque County Sheriff Don Vrotsos, who said he wouldn't issue a permit to someone who is blind. And Patrick Clancy, superintendent of the Iowa Braille and Sight Saving School, who says guns may be a rare exception to his philosophy that blind people can participate fully in life.

Private gun ownership — even hunting — by visually impaired Iowans is nothing new. But the practice of visually impaired residents legally carrying firearms in public became widely possible thanks to gun permit changes that took effect in Iowa in 2011.

"It seems a little strange, but the way the law reads we can't deny them (a permit) just based on that one thing," said Sgt. Jana Abens, a spokeswoman for the Polk County Sheriff's Department, referring to a visual disability.

Polk County officials say they've issued weapons permits to at least three people who can't legally drive and were unable to read the application forms or had difficulty doing so because of visual impairments.

And sheriffs in three other counties — Jasper, Kossuth and Delaware — say they have granted permits to residents who they believe have severe visual impairments.

"I'm not an expert in vision," Delaware County Sheriff John LeClere said. "At what point do vision problems have a detrimental effect to fire a firearm? If you see nothing but a blurry mass in front of you, then I would say you probably shouldn't be shooting something."

Training the visually impaired

In one Iowa county, blind residents who want weapons would likely receive special training.

Wethington, the Cedar County sheriff, has a legally blind daughter who plans to obtain a permit to carry when she turns 21 in about two years. He demonstrated for the Register how he would train blind people who want to carry a gun.

"If sheriffs spent more time trying to keep guns out of criminals' hands and not people with disabilities, their time would be more productive," Wethington said as he and his daughter took turns practice shooting with a semi-automatic handgun on private property in rural Cedar County.

The number of visually impaired or blind Iowans who can legally carry weapons in public is unknown because that information is not collected by the state or county sheriffs who issue the permits.

Clancy, superintendent of the Iowa Braille and Sight Saving School, said the range of sight among people who are classified as legally blind varies greatly. He believes there are situations where such applicants can safely handle a gun.

However, he also expressed concerns.

"Although people who are blind can participate fully in nearly all life's experiences, there are some things like the operation of a weapon that may very well be an exception," Clancy said.

The Gun Control Act of 1968 and other federal laws do not prohibit blind people from owning guns. But unlike Iowa, some states have laws that spell out whether visually impaired people can obtain weapon permits.

Vision requirements are either directly or indirectly part of the weapon permit criteria in some surrounding states.

In Nebraska, for example, applicants for a permit to carry a concealed handgun must provide "proof of vision" by either presenting a valid state driver's license or a statement by an eye doctor that the person meets vision requirements set for a typical vehicle operator's license.

Other states have indirect requirements that could — but don't automatically — disqualify people who are blind. That includes Missouri and Minnesota, where applicants must complete a live fire test, which means they have to shoot and hit a target.

A 50-state database of gun permit requirements published by USACarry.com also shows that South Carolina has a law that requires proof of vision before a person is approved for a weapons permit.

Wisconsin, like Iowa, has no visual restrictions on gun permit applicants. Illinois lawmakers enacted a concealed weapons law in July but permits have not yet been issued. Illinois' qualifications don't specifically require a visual test, but applicants must complete firearms training that includes range instruction.

The National Federation of the Blind does not track states that require vision tests as part of weapon permit processes and has not taken an official stand on the issue. But its members are generally opposed to such laws, said Chris Danielsen, director of public relations for the group.

"There's no reason solely on the (basis) of blindness that a blind person shouldn't be allowed to carry a weapon," Danielsen said. "Presumably they're going to have enough sense not to use a weapon in a situation where they would endanger other people, just like we would expect other people to have that common sense."

Iowa requires training for anyone who is issued a permit to carry a weapon in public, but that requirement can be satisfied through an online course that does not include any hands-on instruction or a shooting test.

A provision in Iowa's law allows sheriffs to deny a permit if probable cause exists to believe that the person is likely to use the weapon in such a way that it would endanger themselves or others. Many sheriffs noted, however, that the provision relates to specific documented actions, and applicants who appealed their cases would likely win.

Hudson, executive director of Disability Rights Iowa, believes changing the state law to deny blind people or others with physical disabilities the right to carry arms would violate federal disabilities law.

Part of the Americans with Disabilities Act requires a public entity to conduct an individualized analysis to make a reasonable judgment before denying a service. Hudson believes someone could successfully challenge Nebraska's proof of vision requirement as illegal.

"The fact that you can't drive a car doesn't mean you can't go to a shooting range and see a target," Hudson said.

Aircraft noise linked to higher rate of cardiovascular disease, according to airport studies

Two international studies have found that aircraft noise may be leading to a rise in heart and lung disease.

Scientists say noise levels could be linked to more stress, sleep deprivation and high blood pressure in people - findings that could have implications for new airports slated for residential areas in Australia.

Professor Paul Elliott from Imperial College London worked on one study that investigated millions of people living near Heathrow.

He found that people living around the major international airport had a 3.5 per cent higher rate of hospital admissions for cardiovascular disease.

The results were vetted for other factors that could affect the data, including sex, ethnicity and smoking.

The boroughs experience noise levels at least 10 decibels higher than the average loud noise, which sits around 70 decibels.

"We know that acute exposure to loud noises can affect a startled reaction in the person with an increase in heart rate and a short-term increase in blood pressure," he said.

"And there is some evidence that this rise in blood pressure may be sustained if there's continual exposure to louder noises."

A vacuum cleaner is about 70 decibels, a lawnmower is about 90 decibels and a jet engine taking off is more than 100 decibels.

Another similar study, conducted by academics at the Boston University School of Public Health and Harvard School of Public Health, looked at six million people aged 65 or more, living around major airports in the United States.

Professor Jon Levy says his results are consistent with the UK findings, with a 2.3 per cent higher rate of hospital admissions.

"The health effects of noise should be thought about and taken into account when looking at airports and airport sitting or expansion," he said.

Strategies to reduce the impact of noise

In the United States, the noise study is being analysed by the US Federal Aviation Authority, which partly funded the research.

Professor Levy says there needs to be a focus on strategies that reduce aircraft noise exposure, including the soundproofing of homes, modified flight paths, and quieter aircraft.

But anti-aircraft noise groups say those measures are just band-aid solutions.

No Aircraft Noise Party spokesman Allan Rees wants a second Sydney airport to relieve the pressure on Kingsford Smith.

"Firstly on the double glazing: this is Sydney," he said.

"This is a mild, moderate climate. We want to have the windows open. We don't want to live in air-conditioned concrete boxes. It's not good living conditions and there's all the outdoor activity that gets interrupted as well.

"As far as the quieter aircraft, as I say, the newer aircraft are quieter, [but] not a great deal. They're still very noisy but that's outweighed by the increase in the number of aircraft and the fact that the average size of the aircraft operating at Mascot is going up steadily."

The Federal Government has not committed to building a second Sydney airport, and the New South Wales Government says capacity at the current site can be safely increased.

Both studies were published in the latest British Medical Journal.

The world Today by Eliza Harvey

Thursday, 10 October 2013

Centipede venom may fight chronic pain

The venom used by a centipede to paralyse prey contains a molecule that new research shows is more effective than morphine in blocking pain.

The finding in mice models could lead to the development of drugs for people with ongoing chronic pain, says co-author of the study Professor Glenn King, of the University of Queensland.

The current study targets human proteins known as voltage-gated sodium channels (Nav) that play a critical role in electrical signalling in neurons and other excitable cells.

King, a research fellow at the Institute for Molecular Bioscience, says humans have nine different Nav channels, with earlier studies showing the Nav1.7 channel plays a key role in pain transmission.

He says people with a mutation of this protein are unable to experience pain.

Previous research to target this channel has been hindered because of the impact of drug candidates on other Nav channels, which among other things play important roles in heart and muscle function.

"The difficulty is finding molecules that are selective for this one [Nav1.7] channel," he says.

In a study published this week in the Proceedings of the National Academy of Sciences, King and his Chinese colleagues show venom from the Chinese redheaded centipede (Scolopendra subspinipes mutilans) has 150 times selectivity for Nav1.7 over other Nav channels.

King says mice were injected with a peptide from the venom - Ssm6a - at a high dose and suffered no side effects with no impact on blood pressure or heart rate.

In thermal and acid-induced pain tests, the effect of the molecule "was similar to morphine", while in chemical-induced pain experiments it was more potent than morphine.

King says it is unlikely humans will develop a tolerance or addiction to drugs based on the venom molecule because unlike morphine it is not used to block receptors.

The work builds on an increasing body of research focusing on animal venoms for use in pain relief, but this is the first study to look at centipedes.

The current study focuses on a centipede that is farmed in China for consumption, but King and his colleagues believe the findings suggest centipede venom - which has been overlooked to date - may provide a source of lead molecules for drug development.

King agrees it is counterintuitive that a molecule used for predation could have therapeutic use.

However he says the key difference in ion channels between insects and humans makes this possible.

In contrast to humans, insects have only a single Nav channel, which is a common target of peptides in the venom of other arthropod predators such as scorpions and spiders.

"Centipedes worked out hundreds of millions of years ago the easiest way to catch prey was to paralyse them by blocking their Nav channel," King says.

"We're just lucky that of the nine Nav channels in humans, it hit the one we were after."

Recent US studies have shown the economic cost of chronic pain to be about $600 billion annually - more than the combined annual cost of cancer, heart disease and diabetes.

King says it is estimated at any one time about 20 per cent of the population on average is suffering from chronic pain, defined as pain that persists for three months or more.

He says the next step in their research is to trial the peptide using more sophisticated pain models that replicate pain associated with conditions such as rheumatoid arthritis and cancer.