Tag Archives: United States

Gonorrhea Becoming More Resistant to One Antibiotic: CDC

One of several antibiotic treatment options for the sexually transmitted disease gonorrhea seems to be losing its effectiveness, U.S. health officials warn in a new report.HealthDay news image

The U.S. Centers for Disease Control and Prevention’s latest tracking suggests that although resistance to the antibiotic treatment cefixime went down between 2011 and 2013, it started to creep back up in 2014.

The good news is that cefixime isn’t usually the first drug of choice for treating gonorrhea infections. The CDC’s most recent guidelines for gonorrhea treatment (issued in 2012) recommend only using cefixime when the preferred option — ceftriaxone-based combination therapy — isn’t available. And the CDC’s new report doesn’t indicate any recent waning in the effectiveness of that combination therapy.

Still, indications of antibiotic resistance among any gonorrhea treatment is considered troubling, the study authors said.

“It is essential to continue monitoring antimicrobial susceptibility and track patterns of resistance among the antibiotics currently used to treat gonorrhea,” said study lead author Dr. Robert Kirkcaldy, an epidemiologist in the CDC’s division of STD prevention in Atlanta.

“Recent increases in cefixime resistance show our work is far from over,” he said.

The study findings are published as a research letter in the Nov. 3 issue of the Journal of the American Medical Association.

The CDC noted that gonorrhea is spread during unprotected vaginal, anal or oral sex. The sexually transmitted infection is particularly common among youth and young adults between the ages of 15 and 24.

Many people have no symptoms when infected. When symptoms do occur, they may include a painful or burning sensation when urinating; painful, swollen testicles and discolored discharge from the penis among men. In women, symptoms may include increased vaginal discharge and vaginal bleeding between periods. Rectal infections may spark soreness, itching, bleeding, discharge, and painful bowel movements, the CDC said.

If gonorrhea goes untreated, “serious health complications” can result, Kirkcaldy said. Those can include chronic pelvic pain, infertility and life-threatening ectopic pregnancy — an abnormal pregnancy that occurs outside of the uterus. In rare cases, gonorrhea can spread to your blood or joints, causing a potentially life-threatening infection, the CDC warned.

But when identified, antibiotics can provide an effective cure for those with gonorrhea.

The new CDC study looked at treatment outcomes among male gonorrhea patients who had been treated at public clinics across the United States between 2006 and 2014.

More than 51,000 samples were gathered across 34 cities. About one-third were collected in the western United States and one-third collected in the South. A little more than a quarter of the samples were drawn from men who either identified as gay or bisexual, the study said.

The investigators found that the CDC’s 2012 shift away from recommending cefixime and toward ceftriaxone-based combination therapy had a profound impact: while the combination therapy had been given to less than 9 percent of the patients in 2006, that figure shot up to nearly 97 percent by 2014.

Alongside that shift, the team found that cefixime-resistance went up from 0.1 percent in 2006 to 1.4 percent in 2011, and then back down to 0.4 percent in 2013. But by 2014 resistance trended upward to 0.8 percent, the research revealed.

What does this mean? “Trends of cefixime susceptibility have historically been a precursor to trends in ceftriaxone,” said Kirkcaldy. “So it’s important to continue monitoring cefixime to be able to anticipate what might happen with other drugs in the future.”

Dr. Kirsten Bibbins-Domingo, co-vice chair of the U.S. Preventive Services Task Force in Rockville, Md., emphasized the importance of routine screening.

“The task force recommends screening for gonorrhea in sexually active women age 24 years or younger, and in older women who are at increased risk for infection,” she said.

The task force doesn’t advocate for or against screening for men, saying more research is needed to prove effectiveness. However, Kirkcaldy said that the “CDC recommends an annual gonorrhea screening for high-risk sexually active women and for sexually active gay, bisexual, and other men who have sex with men.”

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Scientists have developed an eye drop that can dissolve cataracts

Researchers in the US have developed a new drug that can be delivered directly into the eye via an eye dropper to shrink down and dissolve cataracts – the leading cause of blindness in humans.

While the effects have yet to be tested on humans, the team from the University of California, San Diego hopes to replicate the findings in clinical trials and offer an alternative to the only treatment that’s currently available to cataract patients – painful and often prohibitively expensive surgery.

Researchers in the US have developed a new drug that can be delivered directly into the eye via an eye dropper to shrink down and dissolve cataracts – the leading cause of blindness in humans.

While the effects have yet to be tested on humans, the team from the University of California, San Diego hopes to replicate the findings in clinical trials and offer an alternative to the only treatment that’s currently available to cataract patients – painful and often prohibitively expensive surgery.

Affecting tens of millions of people worldwide, cataracts cause the lens of the eye to become progressively cloudy, and when left untreated, can lead to total blindness. This occurs when the structure of the crystallin proteins that make up the lens in our eyes deteriorates, causing the damaged or disorganised proteins to clump and form a milky blue or brown layer. While cataracts cannot spread from one eye to the other, they can occur independently in both eyes.

Scientists aren’t entirely sure what cases cataracts, but most cases are related to age, with the US National Eye Institute reporting that by the age of 80, more than half of all Americans either have a cataract, or have had cataract surgery. While unpleasant, the surgical procedure to remove a cataract is very simple and safe, but many communities in developing countries and regional areas do not have access to the money or facilities to perform it, which means blindness is inevitable for the vast majority of patients.

According to the Fred Hollows Foundation, an estimated 32.4 million people around the world today are blind, and 90 percent of them live in developing countries. More than half of these cases were caused by cataracts, which means having an eye drop as an alternative to surgery would make an incredible difference.

The new drug is based on a naturally-occurring steroid called lanosterol. The idea to test the effectiveness of lanosterol on cataracts came to the researchers when they became aware of two children in China who had inherited a congenital form of cataract, which had never affected their parents. The researchers discovered that these siblings shared a mutation that stopped the production of lanosterol, which their parents lacked.

So if the parents were producing lanosterol and didn’t get cataracts, but their children weren’t producing lanosterol and did get cataracts, the researchers proposed that the steroid might halt the defective crystallin proteins from clumping together and forming cataracts in the non-congenital form of the disease.

They tested their lanosterol-based eye drops in three types of experiments. They worked with human lens in the lab and saw a decrease in cataract size. They then tested the effects on rabbits, and according to Hanae Armitage at Science Mag, after six days, all but two of their 13 patients had gone from having severe cataracts to mild cataracts or no cataracts at all. Finally, they tested the eye drops on dogs with naturally occurring cataracts. Just like the human lens in the lab and the rabbits, the dogs responded positively to the drug, with severe cataracts shrinking away to nothing, or almost nothing.

The results have been published in Nature.

“This is a really comprehensive and compelling paper – the strongest I’ve seen of its kind in a decade,” molecular biologist Jonathan King from the Massachusetts Institute of Technology (MIT) told Armitage. While not affiliated with this study, King has been involved in cataract research for the past 15 years. “They discovered the phenomena and then followed with all of the experiments that you should do – that’s as biologically relevant as you can get.”

The next step is for the researchers to figure out exactly how the lanosterol-based eye drops are eliciting this response from the cataract proteins, and to progress their research to human trials.

Citizen Scientists Discover Yellow “Space Balls”

Citizen scientists scanning images from NASA’s Spitzer Space Telescope, an orbiting infra-red observatory, recently stumbled upon a new class of curiosities that had gone largely unrecognized before: yellow balls.

“The volunteers started chatting about the yellow balls they kept seeing in the images of our galaxy, and this brought the features to our attention,” said Grace Wolf-Chase of the Adler Planetarium in Chicago.

splash

A new ScienceCast video examines “yellow balls” and their role in star formation. Play it

The Milky Way Project is one of many “citizen scientist” projects making up the Zooniverse website, which relies on crowdsourcing to help process scientific data.  For years, volunteers have been scanning Spitzer’s images of star-forming regions—places where clouds of gas and dust are collapsing to form clusters of young stars.  Professional astronomers don’t fully understand the process of star formation; much of the underlying physics remains a mystery. Citizen scientists have been helping by looking for clues.

Before the yellow balls popped up, volunteers had already noticed green bubbles with red centers, populating a landscape of swirling gas and dust. These bubbles are the result of massive newborn stars blowing out cavities in their surroundings. When the volunteers started reporting that they were finding objects in the shape of yellow balls, the Spitzer researchers took note.

Auroras Underfoot (signup)

The rounded features captured by the telescope, of course, are not actually yellow, red, or green—they just appear that way in the infrared, color-assigned images that the telescope sends to Earth. The false colors provide a way to humans to talk about infrared wavelengths of light their eyes cannot actually see.

“With prompting by the volunteers, we analyzed the yellow balls and figured out that they are a new way to detect the early stages of massive star formation,” said Charles Kerton of Iowa State University, Ames. “The simple question of ‘Hmm, what’s that?’ led us to this discovery.”

A thorough analysis by the team led to the conclusion that the yellow balls precede the green bubbles, representing a phase of star formation that takes place before the bubbles form.

“Basically, if you wind the clock backwards from the bubbles, you get the yellow balls,” said Kerton.

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An artist’s concept shows how “yellow balls” fit into the process of star formation.

Researchers think the green bubble rims are made largely of organic molecules called polycyclic aromatic hydrocarbons (PAHs). PAHs are abundant in the dense molecular clouds where stars coalesce. Blasts of radiation and winds from newborn stars push these PAHs into a spherical shells that look like green bubbles in Spitzer’s images. The red cores of the green bubbles are made of warm dust that has not yet been pushed away from the windy stars.

How do the yellow balls fit in?

“The yellow balls are a missing link,” says Wolf-Chase. They represent a transition “between very young embryonic stars buried in dense, dusty clouds and slightly older, newborn stars blowing the bubbles.”

Essentially, the yellow balls mark places where the PAHs (green) and the dust (red) have not yet separated. The superposition of green and red makes yellow.

So far, the volunteers have identified more than 900 of these compact, yellow features.  The multitude gives researchers plenty of chances to test their hypotheses and learn more about the way stars form.

Meanwhile, citizen scientists continue to scan Spitzer’s images for new finds. Green bubbles.  Red cores.  Yellow balls.  What’s next?  You could be the one who makes the next big discovery.  To get involved, go to zooniverse.org and click on “The Milky Way Project.”

Suicide accounts for more than 40,000 deaths in the US each year, making it one of the top 10 leading causes of death in the country. While psychological factors such as stress, anxiety and depression are known drivers of suicide, a new study claims to have found evidence of a more surprising risk factor: exposure to air pollution.

The researchers, including Amanda Bakian, PhD, an assistant professor of psychiatry at the University of Utah in Salt Lake City, publish their findings in The American Journal of Epidemiology.

Smog over a city

This is not the first study to find a link between air pollution and increased risk of suicide. A 2010 studypublished in The American Journal of Psychiatry found people from over seven cities in South Korea were 9% more likely to commit suicide within 2 days of a rise in air pollution.

And last year, Bakian and colleagues conducted a study that found residents of Salt Lake County were more likely to commit suicide within 3 days of being exposed to increased levels of nitrogen oxide or high concentrations of fine particulate matter (PM 2.5) – particles in smoke and haze that are 2.5 micrometers in diameter or less.

They build on these findings with their latest study, which found middle-aged individuals and men are most at risk of suicide through exposure to air pollution.

Short-term air pollution exposure ‘increased suicide risk by up to 25%’

The team analyzed the records of 1,546 people in Salt Lake County who committed suicide between 2000 and 2010.

Consistent with their previous findings, the researchers calculated that individuals who were exposed to increased levels of nitrogen dioxide were 20% more likely to commit suicide in the following 3 days, while those exposed to higher concentrations of PM 2.5 were 5% more likely to take their own lives within the next 3 days.

Men were found to have an even higher risk of suicide following air pollution exposure; after exposure to increased levels of nitrogen dioxide and PM 2.5, their risk of committing suicide in the following 3 days was 25% and 5%, respectively.

For individuals aged 36-64, the researchers found that short-term exposure to high levels of nitrogen dioxide increased the risk of suicide by 20%, while short-term exposure to high concentrations of PM 2.5 was linked to a 7% increased suicide risk.

Commenting on their findings, Bakian says:

“As suicide risk was found to differ by age and gender, this suggests that vulnerability to suicide following air pollution exposure is not uniform across Salt Lake County residents and that some Salt Lake County residents are more vulnerable than others.

Our next step is to determine in more detail exactly what elements – such as genetic and sociodemographic factors – are responsible for increasing one’s vulnerability to suicide following air pollution exposure.”

The researchers stress that their findings do not indicate that short-term exposure to air pollution is a direct cause of suicide. Instead, they suggest that increased air pollution may merge with other factors that drive suicide risk.

A new study published in the New England Journal of Medicine suggests current estimates about the number of Americans who die from cigarette smoking are too low.

The American Cancer Society (ACS) funded study suggests estimates from the Surgeon General that show smoking kills about 480,000 people in the US every year, exclude tens of thousands of Americans who die from diseases not counted as caused by smoking but perhaps should be.

close up person smoking

For their analysis, Dr. Eric J. Jacobs, strategic director of Pharmacoepidemiology at the ACS, and colleagues reviewed data from 5 large studies, including the ACSCancer Prevention Study-II, the Health Professionals Follow-up Study, the Nurses’ Health Study, and the National Institutes of Health AARP Diet and Health Study.

The data covers nearly a million Americans aged 55 and over that were followed for about 10 years, during which time there were over 180,000 deaths, including nearly 16,500 among current smokers.

As expected, the analysis showed current smokers were nearly three times more likely to die in that time than people who never smoked.

Most of the excess deaths in smokers were due to diseases that are known to be caused by smoking. These include 12 types of cancer, stroke, coronary heart disease and chronic obstructive pulmonary disease (COPD – which includes chronic bronchitis, emphysema and chronic obstructive airways disease).

Smokers had double risk of death from diseases not classed as caused by smoking

However, Dr. Jacobs and colleagues also found that around 17% of the excess deaths in current smokers were attributed to diseases outside of the list of 21 that the US Surgeon General classes as caused by smoking and so are excluded in official estimated US deaths due to tobacco use.

Fast facts about smoking

  • Tobacco use is the leading preventable cause of death worldwide
  • Smoking and tobacco use costs the US $289 billion a year, including more than $156 billion in lost productivity
  • In 2011, the tobacco industry spent nearly $23 million a day on promoting and advertising cigarettes.

Find out why smoking is bad for you

The investigators drew particular attention to where they found a double risk of death among current smokers due to diseases such as intestinal ischemia (narrow or blocked arteries in the gut), kidney failure, infections, hypertensive heart disease and various types of respiratory disorders outside of COPD.

The authors note that even though these diseases are not officially regarded as being a result of smoking, and are therefore excluded from estimates of smoking-related deaths, there is strong evidence to suggest they are.

Their analysis also showed that excess risk of death from each of these conditions fell when participants gave up smoking.

The team found smoking was also tied to smaller increases in risk of death from breast cancer, prostate cancer and cancers of unknown sites. These diseases are currently not formally classed as being caused by smoking.

The authors conclude that the number of additional deaths potentially linked to smoking is significant and may be due to diseases not formally established as caused by smoking. However, should future research show they are, then they should be included in estimates of the death toll from tobacco use.

The study only covered data on one million people taking part in large studies, but Dr. Jacobs says:

“If the same is true nationwide, then cigarette smoking may be killing about 60,000 more Americans each year than previously estimated, a number greater than the total number who die each year ofinfluenza or liver disease.”

The Moon Was A First Step, Mars Will Test Our Capabilities, But Europa Is The Prize

The icy moon Europa is perhaps the most tantalising destination in our solar system. Scientists have been trying for years to kickstart a mission to Jupiter’s most enigmatic moon, with very Earth-like concerns over costs keeping missions grounded until now.

The European Space Agency’s ambitious mission to Jupiter, JUICE, will visit its fire-and-ice moons – volcanic Io, icy Europa, giant Ganymede, and cratered Callisto – in the 2030s. But it will only provide a glimpse of Europa’s surface from a couple of close flybys. With the announcement of the NASA-led Europa Clipper mission, now it looks like a much closer inspection of Europa is on the cards.

It’s hard to overstate the excitement among planetary scientists, after so many years of waiting in the wings while all eyes were on Mars. This is truly a quest to understand what makes a world habitable.

A Watery World

Europa is the smallest and smoothest of the four Galilean moons. At 1,940 miles across, it is roughly a quarter of the size of Earth, composed of a mixture of ices and rocks. When the Galileo spacecraft flew over Europa in the 1990s, it uncovered evidence of a global sub-surface ocean: vast, deep, dark waters hidden beneath the ice crust.

The water doesn’t freeze completely because it’s constantly kneaded by powerful tidal forces as the moon orbits around Jupiter once every 3.5 days. What’s more, the ocean is believed to be in direct contact with the surface ices and the moon’s silicate mantle, which brings together all the necessary ingredients for a habitable environment: liquid water, a source of energy, and a source of minerals/nutrients. We know that life on Earth can exist in even the most extreme environmental conditions (for example, bacteria known asextremophiles), so maybe – just maybe – Europa’s hidden ocean could support life.

The Galilean moons of Jupiter: Io, Europa, Ganymede and Callisto. NASA

What To Look For

Neither JUICE nor Clipper will reach the surface or the ocean below – that’s too great a technological challenge for now. But if habitable conditions for life are discovered beyond Earth, particularly somewhere as far from the Sun as Jupiter and its moons, this could mean that habitable conditions are commonplace throughout our universe.

We must begin to explore Europa via orbital reconnaissance: to image and perform spectral analysis of the composition and geology of the surface, and the radiation, magnetic, electric and plasma fields that sweep across it. With ice penetrating radar we can probe through the icy crust, even as far as the hidden ocean to understand the forces that shape this icy world.

Europa’s ‘chaos terrain’, caused by repeated freezing and melting. NASA

Europa’s fractured and cracked surface is geologically quite young, and relatively crater-free. The structures that the Galileo probe observed from orbit suggest freeze-melt processes that trap icy burgs into frozen seas, creating the scarred patterns known aschaos terrain. Dark parallel ridges criss-cross the bright planes, possibly due to tectonics or other geologic processes.

Most surprising was Hubble’s observations in 2012, which showed evidence of huge plumes or geysers erupting tens of kilometres over Europa’s south pole, potentially contributing to a very thin atmosphere. If we could directly sample those plumes we might just get a glimpse of the composition of the deep ocean.

Sooner Rather Than Later

So for all these reasons and more, Europa remains the highest priority target for a future mission. That there are two missions to the Jupiter system stems from years of study within NASA and ESA. At one point a joint mission, the Europa-Jupiter System Mission, was planned but was not taken forward due to funding constraints.

The Jupiter Icy Moon Explorer, JUICE, and its instruments. ESA

Today, JUICE is full-steam ahead, the project having passed through a full study and definition phase towards now building the spacecraft. If all goes to plan it would launch in 2022 and reach Jupiter in 2030. After two years of multiple fly-bys exploring Jupiter, its moons, rings and magnetosphere, it will become humankind’s first orbiter of an icy moon, targeting Ganymede in late 2032. If NASA’s recently announced funding is confirmed Europa Clipper may proceed even faster, using a new rocket (the Space Launch System) to propel it towards Europa in only a few years, potentially arriving just before or even at the same time as JUICE.

Clipper will conduct multiple flybys of Europa (maybe 45 or more over three years) without entering orbit directly, but will provide the high-resolution reconnaissance necessary to ultimately choose a landing site for some future robotic explorer. Although that future landing mission is beyond the funding horizon right now, it’s exciting to think that we’ll one day see images from that icy and harsh environment, with Jupiter suspended in the black skies above.

Scents may affect how appealing tobacco is- Pleasant scents hook people on tobacco; and smelling stinky scents during sleep might help smokers quit

spearmint

WASHINGTON, D.C. — The minty flavor added to menthol cigarettes might make it even harder for smokers to quit, new research shows.

Most smokers know they should quit. Unfortunately, the nicotine in tobacco is addictive. That makes quitting really hard. Scientists have known that it’s even harder for people who light up menthol cigarettes.

The question has been why, notes Brandon Henderson. He’s a neuroscientist in Pasadena at the California Institute of Technology, or Caltech.

The answer, his team now finds, may have a lot to do with how menthol boosts the effect of nicotine on the brain. Repeated exposure to nicotine leads the brain to make more nicotine receptors — docking stations for the chemical on cells. These nicotinic receptors are proteins. And their role is to impact the brain’s pathways for a chemical known as dopamine (DOPE-uh-meen). Dopamine transmits signals in the brain. Some of those signals turn on centers that convey feelings of pleasure and rewards. Indeed, this feel-good chemical helps make smoking rewarding — and addictive.

To see how menthol might affect this system, Henderson and his Caltech teammates worked with special lab mice. One type of nicotinic receptor in the mice glows cherry red under fluorescent light. Another type glows bright green.

The researchers exposed these mice to menthol. (This chemical occurs naturally in spearmint and peppermint.) Then the experts focused in on a part of the midbrain. It’s known as the ventral tegmental area, or VTA. The VTA plays a role in emotion, motivation and addiction.

Mice exposed to menthol had more of both types of nicotinic receptors than did unexposed mice. The increase was similar to that produced by nicotine, the scientists found.

“This goes to show that menthol is not simply an inert flavoring in cigarettes,” says Henderson. “It has some effects in the brain.” Henderson presented his team’s results here on November 16 at the annual meeting of the Society for Neuroscience.

“The most significant finding from Dr. Henderson’s study is that chronic exposure to menthol can change the number of receptors for nicotine in the brain to a similar extent that nicotine can,” says Marina Picciotto. A neuroscientist at Yale University in New Haven, Conn., she did not work on the new study.

“Menthol may increase the addictive properties of nicotine at the molecular level,” Picciotto concludes. Still, she cautions, scientists need to see if that molecular action affects behavior. And to be sure menthol works the same way in people, she says, “We need more information from human subjects.”

Yolks yoke in folks who smoke

Results from a second study presented at the meeting suggest that adding a foul odor to cigarette smoke could help people cut back on smoking. But the idea may work best if people sleep through the stinky experience.

Anat Arzi is a neuroscientist at the Weizmann Institute of Science in Rehovot, Israel.  Earlier, she and other researchers had shown that people can learn to link some experiences as they sleep.

Arzi now wondered whether that type of learning might influence waking behaviors, such as smoking. To find out, she and other scientists exposed groups of smokers to different odors. One stinky stew mixed together the stench of cigarette smoke and rotten eggs. Another paired the smells of smoke and rotten fish.

Researchers told everyone participating in the study that the experience might help them stop or cut back on smoking. But only those smokers who smelled the foul combos while awake knew what just what the experiment involved.

Other smokers smelled those odors only while they slept. Unlike loud noises or bright lights, odors seldom wake people up.

inhaling stinky smells while sleeping

Some volunteers in a study in Israel were exposed to a mix of foul odors and cigarette smoke during different stages of sleep. These tests showed that stinky sleep smells might help people cut back on smoking.

COURTESY OF MICHAEL COOPER.

One group smelled the nasty smells during Stage 2 sleep. That’s the type that occurs most of the night. Others experienced it during rapid eye movement (REM) sleep. Most dreams occur during REM sleep. The study also included control groups — people who slept while no smells scented the air.

Over the following week, people in each group tracked how much they smoked. People exposed to noxious smells during Stage 2 sleep smoked significantly less than before.

“The reduction was around 30 percent,” Arzi reported. That group smoked significantly fewer cigarettes on each day during the week, too.

In contrast, people treated during REM sleep smoked significantly less on only two of the next seven days. So here, the effect did not seem to last all week. And the group that had been awake when exposed to the odors? They showed no change in their smoking habits.

“In other words, sleep learning can influence later awake behavior,” Arzi concludes. The Journal of Neuroscience published the study by Arzi and her colleagues in November.

“The most significant finding of Dr. Arzi’s study is that pairing a nasty odor with the smell of a cigarette can reduce the amount of smoking for several days — and that this only happens during sleep,” says Picciotto, the Yale neuroscientist.

Arzi’s study paired odors for just one night. It then tracked smoking for only one week afterward. A next step, says Picciotto. “would be to see how long the effect lasts.”

That’s important, because tobacco addiction is a major health problem. In the United States alone, cigarette smoking leads to roughly one in five early deaths each year. That statistic comes from the National Institute on Drug Abuse in Rockville, Md. What’s more, it notes, roughly 85 percent of smokers fail when they try to stop on their own.

For that reason, scientists need to learn all they can about causes and treatments for tobacco addiction. The new studies on smoking and smelly substances could one day help all of us breathe easier.

Power Words

addiction  The uncontrolled use of a habit-forming drug or uncontrolled and unhealthy habit (such as video game playing or phone texting). It results from an illness triggered by brain changes that occur after using some drugs or engaging in some extremely pleasurable activities. Persons with an addiction will feel a compelling need to use a drug (which can be alcohol, the nicotine in tobacco, a prescription drug or an illegal chemical such as cocaine or heroin), even when the user knows that doing so risks severe health or legal consequences. (For instance, even though 35 million Americans try to quit smoking each year, fewer than 15 out of 100 succeed. Most begin smoking again within a week, according to the National Institute on Drug Abuse.)

chronic  A condition, such as an illness (or its symptoms, including pain), that lasts for a long time.

control     A part of an experiment where nothing changes. The control is essential to scientific experiments. It shows that any new effect must be due to only the part of the test that a researcher has altered. For example, if scientists were testing different types of fertilizer in a garden, they would want one section of to remain unfertilized, as the control. Its area would show how plants in this garden grow under normal conditions. And that give scientists something against which they can compare their experimental data.

dopamine  A neurotransmitter, this chemical helps transmit signals in the brain.

fluorescent  Capable of absorbing and reemitting light. That reemitted light is known as a fluorescence.

inert   Inactive or having no chemical or physical effects.

neuroscience  Science that deals with the structure or function of the brain and other parts of the nervous system. Researchers in this field are known as neuroscientists.

neurotransmitter  A chemical substance that is released at the end of a nerve fiber. It transfers an impulse to another nerve, a muscle cell or some other structure.

nicotine  A colorless, oily chemical produced in tobacco and certain other plants. It creates the ‘buzz’ effect associated with smoking. It also is highly addictive, making it hard for smokers to give us their use of cigarettes. The chemical is also a poison, sometimes used as a pesticide to kill insects and even some invasive snakes or frogs.

nicotinic receptors   A group of brain proteins that affects the signaling of dopamine. Repeated exposure to nicotine leads to more of these receptors in particular areas of the brain.

REM sleep    A period of sleep that takes its name for the rapid eye movement, or REM, that occurs. People dream during REM sleep, but their bodies can’t move. In non-REM sleep, breathing and brain activity slow, but people can still move about.

ventral tegmental area  Part of the midbrain. It plays an important role in thinking, motivation, emotions and addiction.

Banned drug reduces brain communication – Brain connectivity drops in rats dosed with ‘bath salts’

bath salts

WASHINGTON — In the late 2000s, a new class of street drugs emerged that were quickly nicknamed “bath salts.” Their name reflected the fact that they looked like small salt-like crystals. Because they were not initially regulated, many teens and others saw them as a “legal” way to get high. That changed in 2011, when U.S. government ruled them illegal. Still, many people continue to use them. A new study now shows why that’s bad. These drugs reduce the ability of different brain regions to communicate, at least in rats.

The finding may explain the paranoia, delirium and aggression that some users of bath-salt drugs experience.

The brain relies on a flow of communications between its different parts. That’s how it processes information. In tests on rats given one type of bath salts, communication levels fell among the 86 brain regions studied.

“The higher the dose, the less connectivity you get in the brain,” concludes neuroscientist Marcelo Febo. “It causes a pretty global reduction.” Febo presented his team’s findings here, on November 15, at the annual meeting of the Society for Neuroscience.

Bath salts work by boosting levels of dopamine (DOPE-uh-meen). It is a messenger molecule related to feelings of reward and pleasure. The drugs also raise levels of norepinephrine (NOR-ep-ih-NEFF-rin) and serotonin (SAYR-uh-TOW-nin). These two brain chemicals are also messengers. They play roles in attentiveness and mood.

Low doses of bath salts can make users feel euphoric and alert. However, things can change just hours after taking one variant, called MDPV (short for 3,4-methylenedioxypyrovalerone). Some users experience a powerful crash. The effects can be unpredictable and dangerous. Users may grow delirious, suicidal or violent.

Febo and his team wanted to investigate the lingering effects of bath salts on the entire brain. The researchers gave doses of either MDPV or salt water to 46 laboratory rats. The experts then waited an hour before scanning the rats’ brains with functional MRI. This special machine uses strong magnetic fields to study brain activity. Among the brain regions in rats given MDPV, levels of synchronized activity dropped broadly.

That change may explain the erratic behavior seen in some people who take bath salts, said Febo, of the University of Florida in Gainesville. The same effect also can occur in people who chronically abuse cocaine and other drugs, he added.

Febo’s team must still compare the effects of MDPV to those of other chemically related stimulants. These include amphetamine (am-FET-uh-meen) and cocaine. So far, attempts to scan the brains of rats dosed with cocaine made the animals too unstable to obtain results.

Without a comparison, the data lack context, said Michael Baumann. He is a neuroscientist at the National Institute on Drug Abuse in Baltimore, Md. “They’re really big findings,” he said. “But the question is, ‘Do other stimulants do this?’ Or is it unique to bath salts?”

Bath salts have nothing to do with bathing. The nickname for this family of drugs comes from their resemblance to the Epsom salt crystals sprinkled in bathwater.

Power Words

amphetamines     Potent drugs that stimulate the brain. They can be used as a medicine to treat attention deficit hyperactivity disorder (ADHD) or other types of disease. However, these can be habit forming (somewhat addictive) and in high doses can provide euphoria, delirium and other symptoms similar to cocaine.

bath salts      The common name, or street name, given to a class or illegal drugs. They get their name from their resemblance to the Epsom salt crystals that some people sprinkle in bathwater to soothe sore muscles.

context     The setting or circumstances that help explain an event, some statement or some conclusion.

delirium      A symptom of mental upset where people become seriously confused or out of touch with what’s happening in their environment. They may no longer realize where they are, how they got there or what’s happening to them. Fevers, some drugs and some sorts of mental illness can all trigger temporary periods of delirium.

dopamine   A neurotransmitter, this chemical helps transmit signals in the brain.

erratic     An adjective that describes omething that happens at unpredictable intervals or a behavior that is unpredictable.

euphoria    A sense of great joy, excitement, self-confidence and/or intense well-being.

fMRI (functional magnetic resonance imaging)  A special type of machine used to study brain activity. It uses a strong magnetic field to monitor blood flow in the brain. Tracking the movement of blood can tell researchers which brain regions are active. (See also, MRI or magnetic resonance imaging)

neuroscience   Science that deals with the structure or function of the brain and other parts of the nervous system. Researchers in this field are known as neuroscientists.

norepinephrine       A type of stress hormone secreted by the adrenal glands. It constricts blood vessels. It also increases the force and rate at which the heart contracts.

paranoia     The feeling of persecution — that people are out to “get” you — or that other people cannot be trusted. It can cause the affected person to feel intense anger, hatred or a sense of betrayal.

serotonin   A chemical present in blood that constricts blood vessels and communicates signals in the brain and nervous system.

stimulant   Something that triggers an action. (in medicine) Drugs (including caffeine) that can stimulate the brain, triggering a feeling of more energy and alertness. Some dangerous illegal drugs can do this too, such as cocaine.

unique      Something that is unlike anything else; the only one of its kind.

variant    A version of something that may come in different forms. (in biology) Members of a species that possess some feature (size, coloration or lifespan, for example) that make them distinct. (in genetics) A gene having a slight mutation that may have left its host species somewhat better adapted for its environment.

2014 Ozone Hole Update

The Antarctic ozone hole reached its annual peak size on Sept. 11, according to scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA). The size of this year’s hole was 24.1 million square kilometers (9.3 million square miles) — an area roughly the size of North America.

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This image shows ozone concentrations above Antarctica on Sept. 11, 2014. Image Credit: NASA. See also NASA’s Ozone Hole Watch website

The single-day maximum area was similar to that in 2013, which reached 24.0 million square kilometers (9.3 million square miles). The largest single-day ozone hole ever recorded by satellite was 29.9 million square kilometers (11.5 million square miles) on Sept. 9, 2000. Overall, the 2014 ozone hole is smaller than the large holes of the 1998–2006 period, and is comparable to 2010, 2012, and 2013.

With the increased atmospheric chlorine levels present since the 1980s, the Antarctic ozone hole forms and expands during the Southern Hemisphere spring (August and September). The ozone layer helps shield life on Earth from potentially harmful ultraviolet radiation that can cause skin cancer and damage plants.

The Montreal Protocol agreement beginning in 1987 regulated ozone depleting substances, such as chlorine-containing chlorofluorocarbons and bromine-containing halons. The 2014 level of these substances over Antarctica has declined about 9 percent below the record maximum in 2000.

“Year-to-year weather variability significantly impacts Antarctica ozone because warmer stratospheric temperatures can reduce ozone depletion,” said Paul A. Newman, chief scientist for atmospheres at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “The ozone hole area is smaller than what we saw in the late-1990s and early 2000s, and we know that chlorine levels are decreasing. However, we are still uncertain about whether a long-term Antarctic stratospheric temperature warming might be reducing this ozone depletion.”

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The graphs above show the progress of the 2014 ozone hole. The gray shading indicates the highest and lowest values measured since 1979. The red numbers are the maximum or minimum observed values. The stratospheric temperature and the amount of sunlight reaching the south polar region control the depth and size of the Antarctic ozone hole. [more]

Scientists are working to determine if the ozone hole trend over the last decade is a result of temperature increases or chorine declines. An increase of stratospheric temperature over Antarctica would decrease the ozone hole’s area. Satellite and ground-based measurements show that chlorine levels are declining, but stratospheric temperature analyses in that region are less reliable for determining long-term trends.

Scientists also found that the minimum thickness of ozone layer this year was recorded at 114 Dobson units on Sept. 30, compared to 250-350 Dobson units during the 1960s. Over the last 50 years satellite and ground-based records over Antarctica show ozone column amounts ranging from 100 to 400 Dobson units, which translates to about 1 millimeter (1/25 inch) to 5 millimeters (1/6 inch) of ozone in a layer if all of the ozone were brought down to the surface.

The ozone data come from the Dutch-Finnish Ozone Monitoring Instrument on NASA’s Aura satellite and the Ozone Monitoring and Profiler Suite instrument on the NASA-NOAA Suomi National Polar-orbiting Partnership satellite. NOAA measurements at South Pole station monitor the ozone layer above that location by means of Dobson spectrophotometer and regular ozone-sonde balloon launches that record the thickness of the ozone layer and its vertical distribution. Chlorine amounts are estimated using NOAA and NASA ground measurements and observations from the Microwave Limb Sounder aboard NASA’s Aura satellite.

NASA and NOAA are mandated under the Clean Air Act to monitor ozone-depleting gases and stratospheric depletion of ozone. Scientists from NASA and NOAA have been monitoring the ozone layer and the concentrations of ozone-depleting substances and their breakdown products from the ground and with a variety of instruments on satellites and balloons since the 1970s. These observations allow us to provide a continuous long-term record to track the long-term and year-to-year evolution of ozone amounts.

Mystery in the Ozone Layer

 High above Earth, more than 20 miles above sea level, a diaphanous layer of ozone surrounds our planet, absorbing energetic UV rays from the sun.  It is, essentially, sunscreen for planet Earth. Without the ozone layer, we would be bathed in dangerous radiation on a daily basis, with side effects ranging from cataracts to cancer.

People were understandably alarmed, then, in the 1980s when scientists noticed that manmade chemicals in the atmosphere were destroying this layer. Governments quickly enacted an international treaty, called the Montreal Protocol, to ban ozone-destroying gases such as CFCs then found in aerosol cans and air conditioners.  On September 16, 1987, the first 24 nations signed the treaty; 173 more have signed on in the years since.

Fast forward 27 years.  Ozone-depleting chemicals have declined and the ozone hole appears to be on the mend. The United Nations has called the Montreal Protocol “the most successful treaty in UN history.” Yet, despite Montreal’s success, something is not … quite … right.

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A new ScienceCast video looks into the surprising abundance of carbon tetrachloride in the ozone layer.  Where is it coming from?

A new study by NASA researchers shows that a key ozone-depleting compound named carbon tetrachloride (CCl4) is surprisingly abundant in the ozone layer.

“We are not supposed to be seeing this at all,” says NASA atmospheric scientist Qing Liang.

Between 2007 and 2012, countries around the world reported zero emissions of CCl4, yet measurements by satellites, weather balloons, aircraft, and surface-based sensors tell a different story.  A study led by Liang shows worldwide emissions of CCl4 average 39 kilotons per year, approximately 30 percent of peak emissions prior to the international treaty going into effect.

In the 1980s, chlorofluorocarbons became well-known to the general public.  As the ozone hole widened, “CFC” became a household word.  Fewer people, however, have heard of CCl4, once used in applications such as dry cleaning and fire-extinguishers.

“Nevertheless,” says Liang, “CCl4 is a major ozone-depleting substance. It is the 3rd most important anthropogenic ozone-depleting compound behind CFC-11 and CFC-12.”

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Click to learn about the chemistry of ozone depletion from the US Environmental Protection Agency.Web link

Levels of CCl4 have been declining since the Montreal Protocol was signed, just not as rapidly as expected.  With zero emissions, abundances should have dropped by 4% per year.  Instead, the decline has been closer to 1% per year.

To investigate the discrepancy, Liang and colleagues took CCl4 data gathered by NOAA and NASA and plugged it into a NASA computer program, the 3-D GEOS Chemistry Climate Model.  This sophisticated program takes into account the way CCl4 is broken apart by solar radiation in the stratosphere as well as how the compound can be absorbed and degraded by contact with soil and ocean waters.  Model simulations pointed to an unidentified ongoing current source of CCl4.

“It is now apparent there are either unidentified industrial leakages, large emissions from contaminated sites, or unknown CCl4 sources,” says Liang.

Another possibility is that the chemistry of CCl4 might not be fully understood. Tellingly, the model showed that CCl4 is lingering in the atmosphere 40% longer than previously thought. “Is there something about the physical CCl4 loss process that we don’t understand?” she wonders.

It all adds up to a mystery in the ozone layer.