Archive for the ‘medicine’ Category

Being a morning person might have some health advantages

November 12th, 2018
If you consider 10:50 a reasonable time to wake up, it may or may not say something about your breast-cancer risk.

Enlarge / If you consider 10:50 a reasonable time to wake up, it may or may not say something about your breast-cancer risk. (credit: Henrique Simplicio / Flickr)

A paper presented at the National Cancer Research Institute this week has made for some flashy headlines, like this confident declaration from India’s Economic Times: “Ladies, check your alarm: Waking up early may cut breast-cancer risk.” But most headlines have been appropriately measured and wordy, like The Independent’s “Women who prefer to wake up early have lower risk of breast cancer than night owls.”

In amidst the largely cautious coverage is a truckload of confusion over the details. Some reports frame the paper’s findings as being about preference (preferring to wake up early or stay up late) while others frame them as being about behavior (actually waking up earlier, regardless of preference). Some hold questions of cause and effect at arm’s length, while others dive right in with claims about sleep habits causing cancer.

And what’s the data that was used by the National Cancer Research Institute? Health News Review, in its critique of media coverage of the research, reports that researchers examined “self-reported responses” about being a morning person, but genetic data came into the mix, too.

Read 13 remaining paragraphs | Comments

Posted in cancer, Health, medicine, science | Comments (0)

Delivering drugs directly to the eye using microneedles that dissolve

November 9th, 2018
Delivering drugs directly to the eye using microneedles that dissolve

Enlarge (credit: Chen et al. 2018)

Patients with certain chronic eye diseases, like glaucoma and macular degeneration, typically either use inefficient eyedrops or have to get injections directly into their eyes. A team of researchers wants to replace these with a small patch patients can place on the eye, much like a contact lens. When removed, the patch leaves behind microneedles, which slowly dissolve in the corneal fluid, releasing drugs into the eye as they do. They claim it could make treatments more accessible and less painful for patients, while also providing a more controlled release of the drug.

Replacing injections with a patch

Getting drugs into the eye is a challenge. The most effective solutions tend to be unpleasant and involve actual injections into the eyeball. If doctors deliver the injection in a less horrifying part of the body, it can take a dangerously high initial dose to ensure that enough of the drug actually reaches the eye. Eye drops tend to wash out, and they’re surprisingly inefficient: the eye only absorbs about five percent of the drug most of the time. For some patients, these tradeoffs lead to a choice between needles and blindness.

Some recent ideas have focused on contact lens-like hydrogels that keep drugs on the surface of the eye longer than eye drops to surgically implant tiny drug reservoirs into the eye. Others have involved microneedles: pyramid-shaped needles just a few hundred micrometers long. Microneedles have been increasingly popular as a less-painful way to get drugs through a patient’s skin without an injection—they’ve been used to deliver vaccinations, local anesthetics, and anti-diabetic medications.

Read 14 remaining paragraphs | Comments

Posted in cornea, eye, eye disease, glaucoma, macular degeneration, medicine, microneedles, retina, science | Comments (0)

As if heroin weren’t dangerous enough, it now comes with lead poisoning

November 9th, 2018
An opium poppy field in Afghanistan.

Enlarge / An opium poppy field in Afghanistan. (credit: United Nations)

After she admitted swallowing 30 packs of opium, a 51-year-old woman was brought to a hospital emergency room in Tehran, the New England Journal of Medicine reported yesterday. When a CT scan confirmed the presence of several small oval objects in her abdomen, the doctors gave her laxatives. She passed a collection of small, sausage-like opium packs “without complication,” report doctors Nasim Zamani and Hossein Hassanian-Moghaddam.

One of those packs was sent for lab analysis, and results came back confirming opium, and also the presence of lead—a lot of lead. Luckily for this particular patient, she didn’t seem to be showing any symptoms of lead poisoning, but she appears to have got off lightly. Over the past few years, the problem of lead-contaminated opium has become increasingly urgent in Iran, which is used as a major pathway for opium trafficking from Afghanistan.

In early 2016, write Zamani and Hassanian-Moghaddam in a CDC report, another patient case report found blood lead levels 14 times higher than normal. The patient in question didn’t have any obvious exposure to lead, but was known to use oral opium. That prompted tracking of another 800 patients over the next few months, whose blood lead levels ranged from about five times higher than normal, to 1100 times higher. These blood lead levels were substantially higher than earlier reports of lead poisoning in opium users.

Read 6 remaining paragraphs | Comments

Posted in drug trafficking, Health, medicine, science | Comments (0)

Genetics play less of a role in lifespan than we thought

November 8th, 2018
Historical family trees turn up useful new insights into the genetics of longevity, but represent a world of different health risks.

Enlarge / Historical family trees turn up useful new insights into the genetics of longevity, but represent a world of different health risks. (credit: flickr user: Jon. D. Anderson)

Romantic scenes that never happen: your eyes meet. Your heart flutters. This person is the one—you’re sure of it, because you're convinced they'll live to at least 95 years old. It’s what you’ve always dreamed of.

Lifespan doesn't usually make an appearance on people’s lists of what they’re looking for in a partner. But, according to a paper published this week in the journal Genetics, longevity correlates strongly through marriage relationships, meaning that people are pretty good at picking partners who live similar lifespans. Failing to account for that behavior has meant that estimates of the genetic contribution to longevity have been substantially overinflated.

I knew the second I saw your bloodwork

Nobody is choosing partners based on how long they’ll live. As the authors of the paper sagely note, lifespan “cannot be observed until death, at which point the opportunity to mate has ended.” But as anyone who’s ever dated can tell you, people are likely to marry their match (or close to it) in characteristics like wealth and education, which play an obvious role in longevity.

Read 10 remaining paragraphs | Comments

Posted in Genetics, Health, medicine, science | Comments (0)

Llama “nanobodies” might grant universal flu protection

November 5th, 2018
Graphical depiction of a virus.

Enlarge / The flu virus, showing the H and N proteins on its surface. (credit: CDC)

Llama antibodies are different from ours. Our antibodies are a mix of two pairs of proteins, heavy and light, wrapped around each other. Llamas, camels, and sharks all use only a pair of heavy chains. Because they are smaller, they can wedge into molecular crevices that our larger antibodies can’t access. Perhaps that’s why scientists based at The Scripps Institute decided to use them as a basis for flu protection.

There are four types of influenza viruses, creatively termed A, B, C, and D. Influenzas A and B are responsible for seasonal epidemics in humans, and influenza A is the one that causes pandemics. Influenza A viruses are further divided into subtypes based on two proteins on the surface of the virus: hemagglutinin (H) and neuraminidase (N). There are 18 different hemagglutinin subtypes and 11 different N subtypes, leading to nomenclature like H3N1.

Current flu vaccines generate antibodies to the head of the hemagglutinin protein, which is highly variable. This is why we need to get a new shot every year: it ensures we make antibodies that bind to and counteract the strain in circulation that year. Broadly neutralizing antibodies that recognize all forms of hemagglutinin have been made and tested, but they don’t combat influenza B, and they don’t last for very long in our upper airways.

Read 4 remaining paragraphs | Comments

Posted in antibodies, Biology, Flu virus, medicine, science | Comments (0)

Cultural barriers still stand in the way of HPV vaccine uptake

November 4th, 2018
The HPV vaccine is often delivered along with sex education.

Enlarge / The HPV vaccine is often delivered along with sex education. (credit: Pan American Health Organization / Flickr)

Every year, nearly 34,000 cases of cancer in the US can be attributed to HPV, the human papillomavirus . The CDC estimates that vaccination could prevent around 93 percent of those cancers. Yet HPV vaccination rates are abysmal: only half of the teenagers in the US were fully vaccinated in 2017.

Cultural barriers play a role in that low rate. Vaccinating pre-teens against a sexually transmitted infection has had parents concerned that that this would encourage their kids to have sex sooner, with more partners, or without protection or birth control. And vaccine rates vary across different social and cultural groups: for instance, rural teenagers are less likely to be vaccinated than urban ones.

Two recent studies explore different facets of the cultural barriers standing in the way of better HPV vaccine uptake. The first, a paper published last month in the Canadian Medical Association Journal, looks at the data on whether the vaccine encourages riskier sexual behavior and finds no evidence that it does. And the second, an early draft of a paper presented at an American Association for Cancer Research meeting this week, reports the results of a culturally-targeted intervention aiming to increase vaccine uptake among low-income Chinese Americans.

Read 12 remaining paragraphs | Comments

Posted in Health, medicine, science, vaccines | Comments (0)

A new, eye-wateringly high estimate of the cost of obesity in the US

November 1st, 2018
The total cost includes lost productivity, as well as healthcare costs.

Enlarge / The total cost includes lost productivity, as well as healthcare costs. (credit: e-Magine Art / Flickr)

A report released this week puts a surprisingly high figure on the societal cost of obesity in the US: $1.72 trillion annually, or 9.3 percent of GDP. By contrast, the current CDC estimates are in the region of $150 billion, less than one tenth as high.

By far the biggest chunk of that $1.72 trillion is the $1.24 trillion chunk attributed to the “indirect” costs of obesity: the “work absences, lost wages, and reduced economic productivity for the individuals suffering from the conditions and their family caregivers,” the report explains. That is, the bulk comes from costs other than healthcare spending. The estimate for healthcare spending—$480.7 billion annually—is somewhat higher than a range of estimates in reviews of the literature, which hover around $150 to $300 billion, but are still on the same scale.

Estimates like these can vary substantially because of the different methods used in calculating them. For example, a review from 2017 catalogues the different obesity-related diseases that were included in various studies across different countries; respiratory disorders and musculo-skeletal disorders make an appearance in some but not others. A 2016 meta-analysis describes a similarly wide range in how medical costs are calculated.

Read 12 remaining paragraphs | Comments

Posted in Health, medicine, obesity, science | Comments (0)

Spinal-cord stimulation allows three paralyzed men to walk, with assistance

October 31st, 2018
Multiple combined images of a man starting out in a wheelchair progressing to using a wheeled walker.

Enlarge / A composite image showing David Mzee standing and walking with assistance. (credit: EPFL / Hillary Sanctuary)

“It’s an amazing feeling,” says David Mzee, whose left leg was paralyzed in 2010. Mzee has now regained some ability to walk, thanks to a breakthrough in spinal-cord stimulation technology. “I can do a knee extension of my left leg... flex my hip and even move my toes.”

Mzee is one of three participants in a study that used a new technique to overcome spinal-cord injury and restore walking ability in patients with varying degrees of paralysis. The results, published in Nature and Nature Neuroscience today, are dramatic. All three patients recovered some degree of walking ability, and their progress in physical-therapy sessions has translated to improved mobility in their daily lives.

The basis of the technique, called epidural electrical stimulation (EES), is not new at all—it’s been investigated as a potential treatment for paralysis for decades, with a lot of success in animals. And in September this year, two separate papers reported breakthroughs in allowing patients with paralysis to walk, with assistance, as a result of EES.

Read 14 remaining paragraphs | Comments

Posted in Health, medicine, Neuroscience, science | Comments (0)

Eye doctors find that WebMD symptom checker was wrong more than half the time

October 30th, 2018
Giving online symptom checkers the hairy eyeball.

Enlarge / Giving online symptom checkers the hairy eyeball. (credit: Carol Munro / Flickr)

In 2015, The BMJ (formerly British Medical Journal) did a thorough audit of online symptom checkers. It found that, on average, the sites listed the correct diagnosis first only about a third of the time. Carl Shen, an ophthalmology resident at McMaster University, has led a team of researchers in a small-scale follow-up looking specifically at eye health and got equally concerning results: the correct diagnoses popped up first only a quarter of the time.

The results, presented at the Annual Meeting of the American Academy of Ophthalmology this week, are early and provisional, but Dr. Shen and his team are planning a larger follow-up study. In the meantime, WebMD has done an update of its algorithm.

Vignettes of unpleasantries

To assess WebMD’s accuracy, Shen and his colleagues compiled 42 eye-health “clinical vignettes” based on the medical literature. A decidedly unpleasant vignette of someone suffering from acute angle-closure glaucoma, for instance, describes a “44-year-old woman present[ing] to ER... with severe pain around her right eye of four-hour duration... She is also nauseated and has thrown up once... Intraocular pressure is extremely elevated.”

Read 6 remaining paragraphs | Comments

Posted in digital health software, Health, medicine, science | Comments (0)

Gut bacteria recover from antibiotics, but they may take six months

October 28th, 2018
Gut bacteria recover from antibiotics, but they may take six months

Enlarge (credit: Fiona Moore / Flickr)

We’re still understanding the important and complex role that the microbiome plays in human health, though we do know that the trillions of bacteria in the human body influence our immune function and digestion. But beyond what we know, there's simultaneously a fascinating field of research and a lot of hype and scaremongering.

One thing we're still working out is how antibiotics affect the gut microbiome and how well it's able to recover after the treatment is finished. A paper in Nature Microbiology this week finds that, after a course of broad-spectrum antibiotics, 12 men were able to recover to a mostly-normal microbiome level within six months. Nine species of gut dwellers, though, never reappeared; instead, there were some undesirable species of bacteria that managed to take hold.

Albert Palleja and colleagues first collected stool samples from 12 healthy men to see what their microbiomes looked like at the start. The small and specific sample means that the results can’t be generalized, so the study is less a statement on what antibiotics do to people in general and more an exploration of what the possibilities looks like.

Read 7 remaining paragraphs | Comments

Posted in Health, medicine, microbiome, science | Comments (0)