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28
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TUESDAY, JULY 19, 2011
health & science
Lung cancer scans can be unreliable: Study NEW YORK: C T scans to measure lung tumors can be unreliable, potentially leading patients and doctors to believe cancer is growing when it’s not, according to a study. In principle, that could mean stopping a treatment that is actually keeping the tumor in check, researchers said in the study, which they said was the first to test how reliable lung cancer scans are, and appeared in the Journal of Clinical Oncology. “The patient and the doctor both need to understand that small changes don’t necessarily mean much,” said Gregory Riely, at Memorial Sloan-Kettering Cancer Center in New York. “Changes of up to 10 percent can
happen simply as a result of the inherent variability of CT imaging.” For the study, the Sloan-Kettering team asked patients with late-stage lung cancer if they’d be willing to have two chest CT scans within minutes. Thirty-three patients said yes. Doctors normally scan such patients every few months to see if their tumor is growing, which could be a signal to change drugs. Then the researchers gave the images to three radiologists who had no idea the scans had been repeated before the tumors could have grown or shrunk appreciably. But the radiologists reported many
changes, ranging from a 23 percent shrinkage to a 31 percent growth. Overall, three percent of the tumors appeared to have grown so much that doctors would diagnose disease progression according to common criteria. And the smaller the tumor, the bigger the variation. Riely said some doctors will make treatment decisions based on tiny changes seen on scans, although that might be a costly mistake, according to the study’s findings. “We begin to put more and more stock in the data without really understanding the true variability of those measurements,” he said. “The changes are not clinically mean-
ingful and we should not alter clinical care based on them.” Riely did say, though, that the findings did not mean that patients should get repeat scans, which would increase their radiation exposure. Most likely, the results also apply outside of lung cancer, although patients’ breathing could make the chest scans especially variable. Michael Maitland, at the University of Chicago and who wrote an editorial accompanying the study, said it was surprising such a study had not been done up to now and it was likely to be useful. “This is telling us scientifically how much noise is naturally there without any treat-
ment or the cancer getting worse,” he told Reuters Health. “It’s an important thing to do whenever you are going to use any kind of marker for a disease. He added that the findings will be helpful to drug developers, who look at increasingly small changes in tumor size during drug testing, forgetting that the scans might be unreliable at that scale. In addition, the new data can help scientists build better models of cancer progression that might save both time and energy in clinical trials.” There is a real opportunity here to update our systems and take advantage of the new technology,” Maitland said. — Reuters
AIDS forum down to nitty gritty after breakthrough trials WHO scrap guidelines on administering antiretrovirals
GAUHATI: An Indian farmer walks with his ploughing tools and cattle in a paddy field on the outskirts of Gauhati, India, yesterday. The annual monsoon season from June to October brings rains that are vital to agriculture in India. — AP
Foraging for fitness at the driving range NEW YORK: Hitting golf balls at the driving range can lift the spirit, but does it also tone the flesh? The exercise potential of swinging a club may be limited, experts say, but the more fitness you bring to the range, or the golf course, the stronger your stroke will be. “Most people don’t think of the driving range or playing golf as a form of exercise, but it is,” said Robert Yang, a sports performance coach and founder of the Performance Lab in Encinitas, California. “ The professionals make it look smooth like butter but there’s quite a bit of power and strength involved,” Yang said. He explained that wielding a driver can be compared to hoisting a weight so heavy you can only lift it four times. “ That’s how much load or torque there can be on the body.” But don’t expect to swing your way to streamline shape. “The concept of getting in shape from just hitting balls is pretty tough.” Yang said. “You wouldn’t be able to change your body shape.” The volume of exercise is simply not high enough. Yang said even on a golf course, people actually swinging the club for only two-andone-half to three minutes. “The rest of the time you’re just walking,” he said. Conversely, Yang said fortune, on the golf course or on the driving range, favors the fit. “Each body has physical limitations, whether it’s lack of strength or flexibility. If you improve them, you’ll hit the ball further,” he said. “Whether 16 or 60, you should be focusing on strength and power training to improve your golf game.” He said older, often more sedentary, golfers, can transform their game by
working on their posture. “They’ll stand up straighter. They’re able to rotate more efficiently. That improves their golf swing.” Yang said the fit golfer represents a fairly recent paradigm shift in a sport not typically regarded as requiring strength or speed training. “Tiger Woods basically started that whole thing,” he said. “Younger players are much more into fitness, or they’ve been athletes all their lives.” Taking a golf club back over your head, following through and moving your body to strike the ball, involves a range of motion not experienced by most people on a day-today basis, according to Kevin Burns of the American Council on Exercise. The good news is it benefits muscle groups in the core, back, shoulder and abdominals that might not get a lot of attention. The bad news is that’s almost all there is. “Outside of adrenalin rush of striking the ball and hitting it a long distance, there’s very little cardiovascular benefit,” said Burns, a group fitness instructor based in Mankato, Minnesota. Burns said the driving range compares unfavorably to the golf course. “Walking nine to 18 holes has tremendous cardiovascular benefits, especially if you do it on a regular basis,” he explained. Any activity that will get someone off the couch and moving is a good activity, he said , but an overall fitness plan should include cardiovascular, range of motion and weight-bearing exercises. Yang concurs. “If your goal is just to swing a club and be active, then you’ll achieve the goal,” he said. “If you’re looking to lose five inches (12.7 cm) on your waist, that’s not going to happen.” — Reuters
MOSCOW: Swans swim on Patriarshiye (Patriarch’s) Ponds, a popular residential area in downtown Moscow, yesterday. — AFP
ROME: Buoyed by trials of drugs to prevent the spread of HIV, a global AIDS conference yesterday debated how to draft recommendations and muster funds to transform these dramatic results into action in the field. Researchers from around the world were getting their first look at full peer-reviewed data from a trial that, say veteran campaigners, could slow the 30-year-old juggernaut of AIDS. It was carried out among 1,763 couples where one partner was infected by the human immunodeficiency virus while the other was HIV-free. When the infected partner was given an early start on HIV drugs, this slashed the risk of transmitting the virus to the other by 96 percent-a figure readily comparable to the effectiveness of a condom. Other trials, in which the non-infected partner took the drugs, found a risk reduction of up to 73 percent. Even battle-hardened veterans in the war on AIDS are stunned. Antiretroviral drugs which are a lifeline to millions of infected people are poised for a glittering new role, as a tool to prevent viral spread, they say. “We are at an important tipping point,” Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases (NIAID), told AFP. “There is an extraordinary window of opportunity and the sooner we act on it and the more robustly we act on it, the quicker we’ll achieve the goal of turning around the epidemic. “Pure, simple math tells you that the fewer people who are infected, the fewer the people who are going to get infected. We’ve got to turn that knob and get it on the right trajectory.” But Fauci and others said many tasks lay ahead in safely transposing a trial, which takes place in carefully controlled conditions where couples are counselled and supported, into the messy reality of everyday life. Reflecting the historic turn of events, the UN’s World Health Organisation (WHO) yesterday scrapped plans to issue new guidelines on administering antiretrovirals, said delegates. These will now be reviewed in the light of the latest discoveries, they said. “People will be arguing about the next six or eight weeks
ROME: Demostrators clap their hands during the 6th IAS Conference on HIV pathogenesis, treatment and prevention in Rome’s Parco della Musica Auditorim yesterday. — AFP about what to do, the maximum transmission benefit and the maximum treatment benefit, where do they overlap,” said Myron Cohen, lead investigator of the landmark HPTN 052 trial and professor of microbiology and immunology at the University of North Carolina at Chapel Hill. “There will be formal recommendations and there will be momentum, the two things will go in parallel.” Another question, though, is money. After a surge in funding in the last decade, support for AIDS from rich countries has plateaued. Poorer countries are doing more, but there is still a huge gap. Overall, around 16 billion dollars have been earmarked this year, compared to needs estimated at 22 to 24 billion dollars depending on the treatment. Michel Kazatchkine, head of the Global Fund to Fight AIDS, Tuberculosis and Malaria, turned a worried eye to this problem. “The priority right now is reaching people who really need treatment,” he said in an interview, referring a threshold defined by
Snoring can be treated BERLIN: The noises in the bedroom are frightful, night after night after night: wheezing, whistling, snorting, gasping. Snoring can really put a strain on a relationship. While the slumbering partner saws wood, the wakeful one tosses and turns. Often the latter cannot take the chronic sleep deprivation any longer and urges the former to get to the bottom of his or her snoring, noted Alexander Blau, a physician at the Interdisciplinar y Centre for Sleep Medicine at the Charite university hospital in Berlin. The central question is whether the snoring is merely a nuisance or a sign of a serious health condition. “Not everyone’s who snores is ill,” Blau remarked. He said the spectrum of snoring, caused by air flowing through relaxed throat tissues that partially obstruct the airway, ranged from completely harmless noisemaking, to laboured breathing, to lifethreatening sleep apnea, a respiratory disorder “that can cause problems in waking hours as well as during sleep,” according to the German Sleep Society (DGSM). “Benign snoring merely causes noise and stress,” said Jan Loehler, a member of the German Association of Otorhinolaryngologists. Being overweight is one possible cause. Excess body fat stored in the neck and throat can constrict the airway during sleep. The simple remedy: weight loss. Alcohol consumption before bedtime can also cause snoring, Loehler said, because alcohol relaxes throat muscles even more than is usually the case during sleep, thus obstructing the passage of air. The solution is to drink less alcohol or none at all. The DGSM also recommends a “stable circadian rhythm with corresponding sleep hygiene” because people who go to bed at irregular times are at a greater risk of snoring. People with loud, irregular snoring that is punctuated by breaks should by all means see a doctor, advised Blau. Waking up unrested after a night’s sleep and feeling exhausted during the day are also warning signs of what Loehler calls “malignant snoring,”
medically known as obstructive sleep apnea (OSA). This type of snoring can be particularly dangerous for people with a cardiovascular disorder such as cardiac arrhythmia or high blood pressure. In OSA, throat muscles can become so relaxed during the night that the upper airway repeatedly collapses and breathing stops for as long as 30 seconds. The body’s oxygen supply sinks, the amount of carbon dioxide rises and the heart rate slows. Every time this happens, an alarm goes off in the brain, after which blood pressure, heart rate and muscle tension increase. This results in unusually deep breathing and loud snoring, and the snorer feels exhausted the following morning. “There are many methods of treatment, but their effectiveness in many cases hasn’t been scientifically verified,” Blau noted. One of the two standard treatments, he said, is to wear a mask over the nose at night, which keeps the airway open by means of continuous positive air pressure. An alternative is a dental mouthpiece that advances the position of the tongue and soft palate to keep the air passage open. “Theoretically, both the mask and mouthpiece also help in cases of harmless snoring,” Blau said. “But that would be like using a sledgehammer to crack a nut.” Snorers should find out whether anatomical abnormalities of the nose and throat are causing them to snore, Loehler said. Enlarged tonsils, a deviated nasal septum (the partition between the nostrils) or an enlarged inferior nasal concha (a bone in the nose) can hinder breathing through the nose. While surgery can sometimes help, Blau said, much of the available medical literature on the effectiveness of such treatment is not clear-cut. He added, however, that some recent data backs the use of nasal plugs, which also keep the airway open by means of positive air pressure. According to Blau, in industrialized countries more than 50 per cent of the men and about 30 per cent of women snore. — dpa
current WHO guidelines as below 350 CD4 immune cells per microlitre of blood. “There will be spectacular progress over the next five years. We will practically be reaching universal access” to people in this category, Kazatchkine told AFP. “But putting everyone on treatment is not a prospect, either from the resource point of view or from the operational point of view. Half of the people who are infected aren’t even aware of their (infection) status.” AIDS has killed around 30 million people since it was recorded as a novel disease in 1981. More than 34 million people were living with HIV, two-thirds of them in Africa, at the end of 2010, according to UNAIDS. The conference gathers 5,500 specialists, ranging from virologists to pharmacologists and disease trackers. It is staged once every two years by the International AIDS Society (IAS), which also organises the International AIDS Conference, a bigger event that touches on the pandemic’s many social dimensions. — AFP
Astronauts load storage bin on last space shuttle CAPE CANAVERAL: NASA’s orbiting astronauts detached a huge storage bin full of trash from the International Space Station yesterday and loaded it aboard Atlantis for the last shuttle ride back to Earth. The astronauts used a hefty robotic arm to move the bus-size canister, stuffed with nearly 3 tons of packing foam and other space station refuse. It was the last job shared by the shuttle and station crews, numbering 10 astronauts altogether. The hatches between the two spacecraft were to be sealed less than two hours later in what was expected to be an emotional goodbye. “Be sure to give them lots of hugs from all of us!” Mission Control said in a written message to the four shuttle astronauts. Atlantis will undock from the space station early today and aim for a pre-dawn touchdown Thursday. Then it will be retired. It will be some time before there are so many people aboard the space station again. The Russian Soyuz capsules - the only way to get astronauts to the space station for at least the next few years - carry no more than three. Most of the new commercial spacecraft under development also would seat three, although a few may hold four or more. These are still three to five years away from flying. The 21-foot (6.4-meter)-long storage canister named Raffaello, given its Italian roots - was launched aboard Atlantis back on July 8. It carried up nearly 5 tons of food, clothes and other household goods - enough to keep the space station going for another year. NASA wanted to stockpile the orbiting lab in case private companies get delayed in launching their own cargo ships. The first such supply run is expected by year’s end. The retirement of NASA’s three remaining shuttles has been in the works since 2004, barely a year after the Columbia disaster. Then, President George W. Bush announced a new exploration vision aimed at returning astronauts to the moon. President Barack Obama nixed the moon in favor of an asteroid and Mars. The target launch dates: 2025 for an asteroid and the mid2030s for the red planet. Atlantis will remain at Kennedy Space Center for retirement, going on public display. Discovery and Endeavour will be transported to museums in suburban Washington and Los Angeles, respectively. — Reuters