80beats » Health & Medicine

Woman Receives First 3D-Printed Jawbone Transplant

Veronique Greenwood — Wed, 08 Feb 2012 16:48:50 +0000

An 83-year-old woman operated on last summer was the first person to receive an entire 3D-printed jaw transplant, her Belgian doctors announced Monday. The woman’s own lower jaw was riddled with infection, and given her age, and the fact that reconstructive surgery would have been a long and painful process, her doctors decided to have a new jaw specially manufactured for her. The replacement jaw is made out of titanium, assembled in thousands of layers by a 3D printer. It took 4 hours of surgery to get the jaw in place, but that’s just a fifth of how long a reconstructive surgery session would have been. She will receive follow-up surgery later this month to have permanent dentures attached to the jaw.

The new jaw is about 30% heavier than her old jaw was, but the doctors say she’ll get used to it. Someday, though, patients may be able to get replacement bones printed in more bone-like material: scientists are working on getting 3D printers to accept calcium-based substances as ink.

Image courtesy of LayerWise

In Flies, a Prion-Like Protein Helps Maintain Long-Term Memories

Sarah Zhang — Wed, 08 Feb 2012 13:08:56 +0000

What’s the News: When prions or amyloids make the news, it’s usually because they cause mad cow disease or Alzheimer’s—prions, after all, cause any proteins they touch to become as misfolded as they are, and amyloids, which are large clumps of wadded-together proteins, can jam the workings of cells.

But a new study in Cell suggests that a prion-like protein that forms amyloids has a normal, vital function in the brain. Far from being a memory destroyer, this protein, called CPEB, is necessary for long-term memory in fruit flies.

How the Heck:

To see where the protein resides in the brain, the researchers added a fluorescent tag to the fruit fly version of CPEB, which is called Orb2A. They observed that Orb2A formed amyloids at synapses, the junctions between neurons—a promising sign that it could be involved in memory. To see whether Orb2A was actually necessary for memory, the researchers created fly mutants with a defective version of Orb2A. A single amino acid was changed, but that was enough to prevent the formation of amyloids. It was also enough to disrupt the flies’ long-term memory, the team found. As a test of memory, flies had been ...

What’s Causing the Bizarre Plague of Tics in Upstate New York?

Veronique Greenwood — Mon, 06 Feb 2012 21:18:27 +0000

About three months ago, otherwise healthy girls at a high school in LeRoy, NY, started stuttering, jerking, and making odd noises, among other symptoms similar to Tourette’s syndrome, a neurological disorder. The number of people affected has grown now to more than a dozen, though a more specific count is difficult to nail down, and seems to include one boy and one 36-year-old woman in addition to the teenage girls.

What could be causing these symptoms? Health officials have inspected the girls’ school and found no environmental contaminants. A variety of other causes, including the Gardasil vaccine and strep throat, have been investigated as causes of the uncontrollable tics (neither of those panned out, as in each case only some of the girls had had the shots or been sick). The pattern of cases doesn’t suggest an infectious cause. The current best guess comes from a pediatric neurologist who has examined eight of the girls and has given a diagnosis of conversion disorder, which is defined as the development of tics, paralysis, or a variety of other neurology-related symptoms as a result of stress.

Conversion disorder can sometimes be controversial, since it traces its roots back ...

Massage Doesn’t Just Feel Good—It Changes Gene Expression and Reduces Inflammation

Sarah Zhang — Fri, 03 Feb 2012 14:52:38 +0000

What’s the News: If you’ve ever been told been that a massage is good for “releasing toxins”—or to sound more scientific, “lactic acid”—from your muscles, then you’ve been told wrong. Turns out muscle cells do like a good massage, but it has nothing to do with lactic acid.

In the first study on the cellular effects of massage post-exercise, researchers found that massage bolsters chemical signals reducing inflammation and promoting repair of muscle cells.

How the Heck:

Strenuous exercise actually tears your muscle fibers; that’s why an intense workout can leave you sore for days. (Don’t worry—it’s normal and it generally heals fine.) The researchers wanted to study how massage affects this muscle damage, so they made 11 healthy young men cycle to the point of exhaustion. Then, finally, relief! Sort of. One leg on each man was randomly chosen for a 10-minute massage. Unfortunately more pain was then in store for these volunteers. A tissue sample was taken from the quadriceps muscle (often known simply as “quad”) of each leg 10 minutes and 2.5 hours after the massage. Researchers looked at the level of different mRNA, or messenger RNA, transcripts in these tissue samples. mRNA carries the ...

Alzheimer’s Spreads Like a Virus From Neuron to Neuron, Studies Show

Valerie Ross — Fri, 03 Feb 2012 13:30:21 +0000

A protein tangle in an Alzheimer’s-afflicted neuron

Exactly how Alzheimer’s disease proliferates through the brain, overtaking one region after another, has eluded scientists. As the disease progresses, tau—a malformed protein that forms snarls and tangles inside neurons—shows up in more and more brain areas. Researchers have wondered whether tau, and the disease, are working their way out from a single area of origin or mounting numerous, distinct attacks on vulnerable parts of the brain. Two new studies in mice provide strong support for the first idea: Tau see ms to pass from affected cells to their neighbors, spreading much the same way a virus or bacteria infection would.

The studies—one recently published in PLoS ONE, the other forthcoming in Neuron—used mice genetically engineered to produce abnormal human tau protein in the entorhinal cortex, the tiny bit of brain tissue where Alzheimer’s first appears in most patients. Since those cells, but not others, were equipped to produce human tau, any tau that showed up elsewhere in the brain could be traced back to the entorhinal cortex. The researchers watched and waited, and found that the tau proteins spread through neural circuits out ...

Hacking the Microbiome for Fun and Profit: Can Killing Just One Mouth Bacterium Stop Cavities?

Veronique Greenwood — Thu, 02 Feb 2012 17:32:11 +0000

What’s the News: The bacterial hordes that call your mouth home—and yes, even if you brush rigorously, you’ve got ‘em—are generally a pretty benign bunch. Mostly they just mooch around, snagging tastes of whatever you’re eating, but Streptococcus mutans, the bad boy that causes cavities, releases tooth-corroding acid whenever you eat sugar. Even mouthwash that kills everything it touches can’t save you from the ravages of S. mutans in the long term; it just grows back, along with the rest of your bacteria.

Scientists who study the mouth microbiome, however, think that a mouthwash that kills S. mutans and leaves the rest of the bacteria to take over S. mutans‘s real estate could spell the end of cavities. In a small clinical study last year, one team found that one application of the mouthwash knocked down S. mutans levels, and that harmless bacteria grew back in its place. If the mouthwash pans out, it could join the ranks of an emerging new type of treatment: better living through hacking the microbiome.

How the Heck:

The team, whose work is funded by toothpaste manufacturer Colgate-Palmolive, had designed a molecule called C16G2 that had been proven to kill ...

Chemotherapy in Parents May Make Offspring’s DNA Unstable & Riddled With Mutations

Sarah Zhang — Wed, 01 Feb 2012 14:02:56 +0000

Chemotherapy is poison that happens to kill cancer cells faster than it kills healthy cells; that it wreaks havoc on the bodies of patients is unsurprising. But chemo may also affect their unborn children. According to a new study in PNAS, the offspring of mice treated with chemotherapy have higher rates of mutation, even though the offspring themselves were never exposed to the drugs.

The results suggest that these mutations arise from genome destabilization caused by exposure to chemo, rather than just mutated sperm from the treated father. Male mice in the study were exposed to one of three common anticancer drugs—cyclophosphamide, mitomycin C, or procarbazine—and then allowed to mate with untreated females. After sequencing a small piece of DNA from the offspring, the researchers found that mice with treated fathers had mutation rates up to twice that of mice with untreated fathers. Notably, these mutations were present in DNA inherited from both the treated father and untreated mother.

What this likely means, according to the researchers, is that chemotherapy induces epigenetic changes in the sperm. Epigenetic changes don’t affect the underlying DNA sequence, but they alter chemical tags that control how genes are expressed. This ...

How Vultures Eat Human Bodies

Veronique Greenwood — Wed, 25 Jan 2012 20:03:55 +0000

Vultures eating a gazelle.

By now, you’re probably familiar with the Body Farm at University of Tennessee. It’s one of the places where bodies donated to science go to rot while being closely observed by appreciative forensic scientists, and we say that with the greatest respect: if not for the brave few who gave their mortal remains to be studied, we would have a much harder time telling when and how people found in fields, woods, and other unusual locales died. Now, scientists working at another Body Farm-like facility, Texas State University’s Forensic Anthropology Research Facility, have performed a fascinating study to see exactly what happens when a human body is eaten by vultures.

Their findings imply that vultures can take much longer—37 days instead of 24 hours—to find a body than the carcass of a pig left in the wilderness, which is what previous studies in the Texas facility have used. On the other hand, vultures can also pick clean, or skeletonize, a body much faster than we’d thought: it took just 5 hours instead of the expected 24. The scientists also tracked where the vultures spread the body parts that they didn’t ...

Discovering Long-Lost Relatives Through Commercial DNA Tests

Veronique Greenwood — Tue, 24 Jan 2012 17:16:41 +0000

Family reunion time!

Digging around in your DNA is getting cheaper and easier all the time. For only $207, you can now subscribe to 23andMe’s genotyping service, for instance, which gives you information about your genetic background, potential disease susceptibilities, and other traits. And as the numbers of people in such companies’ databases climb into the hundreds of thousands, it has become possible for software to connect customers who share so much DNA, they may well be relatives. For adoptees who don’t have access to their adoption records and are curious about biological family, there’s never been a better time to go searching. The New York Times follows the story of one 42-year-old woman who, after learning she was adopted, finds her third cousin through a DNA service, and details the relationship that they form as she deals with the revelation that she is not, after all, the daughter of her adoptive parents.

About five weeks after shipping off two tiny vials of her cells from a swab of her cheek, Mrs. Vaughan received an e-mail informing her that her bloodlines extended to France, Romania and West Africa. She was also given the names and ...

A Possible Treatment for a Deadly Food Poisoning Toxin

Veronique Greenwood — Fri, 20 Jan 2012 18:03:21 +0000

Shiga toxin is nasty stuff. If you are infected with a Shiga-producing bacterium, like Shigella dysenteriae or some E. coli strains, there is no clear treatment: if you are given antibiotics, your infected cells will explode, spraying the toxin all over neighboring cells and exacerbating your symptoms. Each year, 150 million people are infected with Shiga-producing bacteria, which cause dysentery and food poisoning, and a million of those die. The lack of effective treatment for such Shiga toxicosis infections is one of the main reasons this year’s outbreak of E. coli poisoning in Europe was so deadly, with more than 3,700 people infected and 45 dead. But now scientists studying how the toxin makes its way around the cell have discovered that treating mice with the metal element manganese makes them resistant to Shiga poisoning. Since manganese’s chemistry is already well understood and it’s readily available, the possibility of using it as a treatment is exciting.

Here’s how manganese blocks Shiga’s spread, according to the group’s experiments in cultured human cells:

Normally, bacterial toxins trying to gain access to your cells are intercepted and sent to be destroyed by sacs of enzymes called lysosomes. Shiga, however, hitches ...

Study: When Doctors Predict How Long You Have to Live, They’re Pretty Much Guessing

Valerie Ross — Thu, 19 Jan 2012 17:43:17 +0000

A recent column by Dr. Pauline Chen at the New York Times explores a surprising oversight in modern healthcare: Doctors don’t really have a clue how to predict how long a patient will live. In the absence of a widely accepted, systematic method of prognosis, they’re kind of making it up—an informed guess, with the benefit of education and experience, but a guess nonetheless.

Prognosis was once a diligently studied, widely practiced part of a physician’s job, Chen writes. But as treatments improved, and keeping patients alive longer became ever more possible, the unpleasant but necessary skill of predicting when patients might die fell by the wayside. A recent study, she reports, revealed just how much:

Prognosis was rarely, if ever, alluded to in the most popular medical textbooks and on clinical Web sites used by practicing physicians. Even the widely used medical database PubMed, maintained by the National Library of Medicine, had no specific indexing category for prognosis, making finding any published study on the subject like searching for a book in a library before the Dewey Decimal System.

Any individual prognosis, of course, may prove to be wrong, however reliable the ...

Research on Quebec’s Rare Brain Disease Could Help Unravel the Common Ones

Valerie Ross — Tue, 17 Jan 2012 19:56:15 +0000

Artist’s rendering of a mitochondrian, the energy-producing
cellular structure affected by ARSACS

Scientists have pinpointed the cause of a rare, fatal neurodegenerative disorder called ARSACS, or autosomal recessive spastic ataxia of Charlevoix-Saguenay. The disease is due to defects in neuron’s mitochondria, the bit of biological machinery that generates energy for the cell—a structure known to be affected in Parkinson’s, Alzheimer’s, and other neurological diseases, as well.

ARSACS was first observed in the descendants of a small group of 17th century French settlers who made their homes near the Charlevoix and Saguenay rivers in what is now Quebec, and has since been seen worldwide. But its incidence remains unusually high in that particular French Canadian community, with 1 in 1,500 to 2,000 people developing ARSACS and 1 in 23 people unaffected genetic carriers of the disease.

The first symptoms of ARSACS appear in early childhood, often as a two- or three-year-old learns to walk, a skill that—because t he disease primarily affects the cerebellum, the brain’s motor control center—those suffering from ARSACS never master. As the disease progresses, it leads to muscle weakness, slurred speech, and difficulty coordinating or controlling movement. People with ARSACS ...

Tuberculosis Resistant to All Known TB Drugs Surfaces in India

Veronique Greenwood — Sat, 14 Jan 2012 14:03:16 +0000

When tuberculosis kills lung tissue, it can produce gaping
holes like in the lung on the right.

For a long time, tuberculosis was a gruesome and incurable disease. Antibiotics changed that, but over the last century, as the drugs have been incorrectly used, the tuberculosis bacterium has been developing resistance to them. Multi-drug resistant tuberculosis, which requires a cocktail of many drugs to treat it, has become common. Now Indian doctors have reported in a medical journal that a strain that is resistant to all known drugs for tuberculosis has appeared in Mumbai. Twelve patients so far have been diagnosed with the strain, and it’s likely that they are just the tip of the iceberg in terms of those infected.

At the Superbug blog, Maryn McKenna explains that this is the third time on record that totally drug-resistant TB (TDR-TB) has appeared. The most recent cases were in Iran in 2009, but the earliest cases were in Italy in 2003, in two middle-class Italian women:

They were both diagnosed by local doctors and treated with repeated rounds of the normal TB drugs — three rounds each — before someone recognized that something unusual was ...

Captive Cheese Fungus Gobbles Up Spills, Forming a Living, Self-Cleaning Surface

Veronique Greenwood — Tue, 10 Jan 2012 18:11:21 +0000

How a living material of cheese fungi sandwiched between plastic sheets works.

The crusty rind of cheeses like Camembert provide more than texture: they are miniature fortress walls, made of fungus, that protect the cheese’s creamy insides from bacterial invasions. Now, taking inspiration from this delicious snack, chemical engineers at ETH Zurich in Switzerland have shown that such a fungus can be enclosed in porous plastic and will digest spills, with implications for creating antibacterial surfaces from living material.

The team sandwiched a layer of Penicillium roqueforti—from, you guessed it, Roquefort cheese—between a plastic base and a top sheet of plastic with nanoscale pores that allowed gas and liquids to move through, but did not allow the fungus to spread. Then, they mimicked a kitchen spill by pouring sugary broth on the surface and watched as, over the course of two weeks, the captive fungus gradually consumed the entire spill, leaving the surface clean. As shown in the figure above, the fungi can go dormant when there is no food around, so if one had a countertop of such a material, you wouldn’t need to keep spilling sugar on it to keep the fungi happy. ...

Baby Monkeys Have Cells From Up to Six Parents

Veronique Greenwood — Mon, 09 Jan 2012 21:31:18 +0000

Roku and Hex from OHSU News on Vimeo.

Researchers have announced the birth of three unusual, though healthy, baby monkeys. They are the first non-mouse chimeras—creatures made up of cells from multiple other parents—to be created by science.

Making chimeric mice is a time-consuming but fairly routine part of biology these days: embryos are injected with modified cultured stem cells containing the traits the researchers desire (like glowing in the dark). Those embryos grow up into mice who have some glow-in-the-dark cells and some normal cells, called chimeras. These chimeras are useful because if any of them have glow-in-the-dark sperm or eggs, they can be bred with each other to produce babies who are 100% glow-in-the-dark.

These scientists tried to do the same thing with monkey embryos, but the cultured embryonic stem cells they injected didn’t take. So instead, they jumbled together cells from 3 to 6 blastocysts—that’s a very early stage of embryonic development, just after a fertilized egg—chose the 14 healthiest-looking resulting clusters, and implanted them into female monkeys. These three little guys—dubbed Roku, Hex, and Chimero—were the ones eventually delivered. They are all male, but some of their cells have female genomes.

The team ...

How Stephen Hawking Has Survived to Age 70

Veronique Greenwood — Mon, 09 Jan 2012 18:04:36 +0000

Party hats out, everyone! Stephen Hawking turned 70 years old yesterday, 49 years after being told he had fewer than four left to live.

The Cambridge professor suffers from a motor neuron disease related to Lou Gehrig’s disease that has gradually taken from him his ability to move, feed himself, and speak, except through a synthesizer that he operates using a cheek muscle (unfortunately, his control of that muscle is also fading). But despite these handicaps, he has survived to an incredible ripe old age—the average for an Englishman is currently 77.2—and has continued his work as a cosmologist and physicist throughout. How has he managed to live so much longer than expected? Katherine Harmon at Scientific American asked neurologist Leo McClusky, who specializes in such diseases:

One thing that is highlighted by this man’s course is that this is an incredibly variable disorder in many ways. On average people live two to three years after diagnosis. But that means that half the people live longer, and there are people who live for a long, long time.

Life expectancy turns on two things: the motor neurons running the diaphragm—the breathing muscles. So the common ...

How Well Do Drugs Work? Hidden Research Sometimes Makes It Hard to Tell

Veronique Greenwood — Fri, 06 Jan 2012 19:14:03 +0000

What’s the News: Scientific publishing is how researchers get the word out about what they’ve learned. It’s how people outside the lab learn whether a drug was safe or not, or whether a treatment had any effect. But a team of scientists looking at a sample of clinical trials funded by the US government found that 30 months after the trials were completed, more than half had not yet been published. And that means that other studies trying to assess whether those treatments are safe and effective are working with incomplete information, while the relevant trials, already paid for by the public, are gathering dust on a lab bench.

How the Heck:

The team, whose study appears in a special report in the British Medical Journal, looked at clinical trials listed as having finished in December 2008 on ClinicalTrials.gov. Of the 635 they examined, 341 (54%) were not published in a peer-reviewed journal within 30 months of the end of the trials. 51 months after completion—that’s over four years—a third of the trials remained unpublished. That could have a serious effect on research and health. Another team whose work appears in the BMJ special issue took information the FDA ...

Can You Give Someone Cancer?

Veronique Greenwood — Wed, 04 Jan 2012 16:52:45 +0000

Hugo Chavez, president of Venezuela, has speculated that the fact that he and four other South American leaders have all recently come down with various cancers could be a sign that the US has developed methods to give people cancer. Uh, is that even possible? Slate‘s Explainer does a thorough, interesting walk-through of all the reasons why the answer is, “Not reliably.”

You could…contaminate the victim’s diet with high levels of aflatoxin, which is associated with liver cancer. Or you could infect him with any of a number of cancer-causing biological agents. Helicobacter pylori contributes to the development of gastric cancer, and human papillomaviruses can cause cervical, anal, and a few other forms of cancer. But these tactics probably wouldn’t produce cancer in the short term and aren’t guaranteed to have any effect at all. In countries with high aflatoxin exposure, like China and parts of Africa, fewer than 1 in 1,000 people develop liver cancer.

If we knew how to give people cancer reliably, we might be better at preventing it. As it stands, cancer prevention, except for a few stand outs like quitting smoking, is can ...

In Uganda, Another Outbreak of Nodding Syndrome, a Disease Epidemiologists Can’t Explain

Valerie Ross — Tue, 27 Dec 2011 21:50:24 +0000

Nodding syndrome, a disease that has sickened more than a thousand children in northern Uganda since the summer, is named for its most distinctive symptom: involuntary, at times violent bobbing of the head, like someone repeatedly nodding yes or snapping out of a doze. Outbreaks of nodding syndrome cropped up in South Sudan this summer, in the same region of Uganda two years ago, in southern Sudan—not yet an independent nation—in 2001, and periodically in remote mountain villages in Tanzania. Nearly half a century has passed since the first reported case, but epidemiologists still have only a rudimentary understanding of this mysterious disease. They’ve found few hints as to what might cause it, and no effective treatments.

The diseases strikes otherwise healthy children, usually between ages 5 and 15. The children first have trouble concentrating; soon, the characteristic head-nodding, often triggered by eating or the sight of food, begins. As the disease progresses, it stunts growth and leads to physical disabilities and cognitive decline. The prognosis only gets worse from there: pediatrician Jennifer Foltz, an Epidemic Intelligence Service Officer who tracked the 2009 Ugandan outbreak, sa ys in a CDC video about the condition, “We haven’t ...

Beware the Improperly Used Neti Pot: Brain-Eating Amoebas Could Strike

Veronique Greenwood — Thu, 22 Dec 2011 18:53:31 +0000

A neti pot in action.

As you may have heard by now, two people in Louisiana have died from infections of brain-munching microbes after making a small, but fatal, error. While filling their neti pots, devices that send water flowing through your nasal passages to clear them out during a cold, they used tap water instead of distilled or sterilized water. Just their luck, the tap water had a few Naegleria fowleri in it, and soon, as the microbes made their way through the nasal passages to the brain, those poor folks had a lot more than a cold to worry about. The mortality rate of human Naegleria fowleri infections is 98%.

Tap water is generally safe for most purposes, and drinking a few of these guys isn’t a problem, since your stomach acid digests them pronto, as Jennifer Frazer over at the Artful Amoeba notes (also, she points out—these aren’t actually amoebas, but distant cousins, and yes, these are the same little guys that sometimes kill swimmers). But your deep nasal passages are quite a bit closer to your brain and aren’t equipped with such protection. Be careful, all you neti pot ...

Methadone, Used to Treat Pain, Kills Thousands Every Year

Douglas Main — Tue, 20 Dec 2011 14:53:19 +0000

Methadone is commonly given to people trying to kick a heroin addiction. But the long-lasting opioid is also an inexpensive, effective pain-killer. With rising costs of prescription narcotics like OxyContin, doctors are increasingly prescribing methadone to treat pain, especially to patients on Medicaid or less generous health insurance plans. From 1999 to 2005, its use in the U.S. increased more than five-fold, according to the U.S. Drug Enforcement Administration. But over the same time period, deaths associated with the drug have increased more than five times, climbing from 786 in 1999 to 4,462, according to the CDC. In Washington state alone, more than 2,100 people died after taking the drug since 2003, says says The Seattle Times.

Methadone’s pain-killing effects last only four to eight hours, but it stays in the body much longer; studies have put the high end of its half-life between 59 and 128 hours. That means the pharmaceutical’s dangers—specifically, it’s ability to depress and eventually paralyze the respiratory system—last much longer. This means patients in pain might be tempted to take more of the medicine without being aware of the toxic buildup. Read more ...

Would Minutes of Exercise Be a Better Metric Than Calorie Counts?

Veronique Greenwood — Mon, 19 Dec 2011 20:10:41 +0000

When we rip open a 100-calorie snack pack, few of us have an idea of how much energy that really is–or how much walking, biking, or schlepping groceries it will take to burn it off. But what if nutrition labels included descriptions of how much exercise you’d need to burn off that candy bar?

One recent study explored that possibility by testing the effects of signs describing in one of three different ways the energy contained in a sugary drink. Researchers found that a sign that said “Did you know that working off a bottle of soda or fruit juice takes about 50 minutes of running?” halved the number of drinks purchased from a drink cooler by African American teenagers, while signs that mentioned calorie count or percentage of total recommended calorie intake did not have a significant effect. Though the study was pretty small, and thus should be verified with larger studies, the effect seems plausible, given that exercise is a much more concrete measure of energy value than calories. Some health campaigns have in fact already taken up this tactic: if you’re a New Yorker, you may have noticed subway ads using exactly this ...

Cocaine Concentrations in the Air Above Italian Cities Correlate with Drug Use

Veronique Greenwood — Mon, 19 Dec 2011 18:30:05 +0000

Drugs have a habit of making their way from our bodies into the environment: they’ve frequently been found in waste water, drinking water, and rivers (not to mention on dollar bills). But they could also be rising into the air, and a new study suggests their aerial concentrations could give scientists a clue to what, exactly, is happening on the ground below. Following up on earlier research showing that cocaine was present in the air above the cities of Taranto and Rome, Italian researchers at the Institute of Atmospheric Pollution Research in Rome took about 60 samples of air in various regions and tested for a number of contaminants, including cocaine, cannabinoids (chemicals found in marijuana), and more common pollutants, like ozone and hydrocarbons. When they looked to see whether there was a correlation between cocaine concentration and addicts’ requests for treatment in particular geographical areas, they found a very strong relationship. Weaker correlations existed between cocaine concentration and police seizures of cocaine and concentration and seizure of all kinds of illicit substances.

The team is excited about the possibility of using aerial cocaine concentration to get a sense of drug ...

Panel Finds That Nearly All Invasive Chimp Research is Unnecessary; NIH Agrees

Veronique Greenwood — Fri, 16 Dec 2011 18:17:31 +0000

After seven months of deliberation, the US Institute of Medicine has released a report that marks a turning point in the use of chimpanzees, humanity’s closest relative, in medical research. An IOM panel found that chimpanzees were in the vast majority of cases no longer required for disease research and laid out three stringent rules against which all current and future chimp research should be judged. Within two hours, Francis Collins, the head of the National Institutes of Health, announced he had accepted the group’s analysis and would set up a committee to apply the rules to proposed and ongoing research projects funded by the NIH.

The recommendation is a reflection of our growing realization that chimps may be capable of self-awareness, empathy, grief, and happiness, and may possess basic morality as well as a culture; Brandon Keim, who has covered chimp research extensively for Wired, notes that some scientists have begun to think they should qualify as nonhuman people. Subjecting them to disease, pain, and psychological trauma in the service of research thus has grown to seem ethically dubious, especially after it was revealed that the NIH ...

Study Finds New Culprit in 2009 E. Coli Outbreak: Tainted Flour in Cookie Dough

Douglas Main — Tue, 13 Dec 2011 17:51:49 +0000

One of the most universally agreed upon facts in the world is that raw cookie dough is delicious. But it can also make you sick, though the ingredient to blame may be a surprise: In study published online in the journal Clinical Infectious Disease, researchers linked the 2009 outbreak of E. coli O157:H7 to tainted flour in Nestlé’s Toll House ready-to-bake cookie dough. Although they haven’t conclusively pinpointed the culprit, flour is the prime suspect after a detailed traceback investigation, since the other ingredients—including eggs—underwent a “kill step” to eliminate germs. In homemade cookie dough, eggs remain a possible source of contamination, particularly from Salmonella.

Regardless of origin, “consumers should not eat unbaked cookie dough,” says study author Karen Neil. And that means you, young ladies. In the 2009 outbreak (which affected 77 people and sent about half to the hospital), two-thirds were under the age of 19 and 71 percent were female.

But raw flour shouldn’t necessarily be demonized as a killer food: Physician William Schaffner tells ABC News that labeling it “risky” may be a bit of a stretch, saying it’s similar to eating a rare or medium rare steak. “Eating cookie ...

Four Hemophiliac Patients Successfully Treated with Gene Therapy

Veronique Greenwood — Mon, 12 Dec 2011 21:53:53 +0000

Hemophilia, a disease whose victims can suffer serious internal bleeding and may bleed to death from injuries, has a long and eventful history. Caused by defective blood clotting factors, the disease has been with us since at least the second century, when a rabbi gave mothers whose first two sons had bled to death from circumcision wounds permission to leave the third sons uncircumcised. It also famously afflicted several members of European royal families. But a study published in the New England Journal of Medicine brings us a bit closer to a new kind of historic event: a cure.

Following up on years of preclinical trials, including the curing of hemophiliac mice earlier this year, scientists gave six patients a gene therapy treatment, injecting them with a specially built virus carrying a functioning version of the gene for the defective clotting factor. The virus inserted the gene into liver cells, which proceeded to manufacture the clotting factor, and the patients maintained elevated levels of it for over 6 months. Four of the patients were able to stop receiving injections of clotting factor (the current treatment) altogether.

The scientists are monitoring patients ...

Diseases You Can Get From Your Pets: Plague, MRSA, Meningitis…

Veronique Greenwood — Mon, 12 Dec 2011 18:20:23 +0000

Anyone who’s watched a cat engage in a strenuous butt-licking session only to come over and start in on cleaning up your hand has probably wondered how healthy this can possibly be. Maryn McKenna over at Superbug has uncovered a paper that will probably terrify, but may, with its detailed descriptions of diseases contracted from pets (did you know you can get meningitis from dogs?), fascinate you. From the paper, titled “Zoonoses in the Bedroom”:

“A 2008 matched case–control study surveyed 9 plague survivors, 12 household members of these survivors, and 30 age- and neighborhood-matched controls about household and individual exposures. Four (44%) survivors… reported sleeping in the same bed with a pet dog…

“Two cases of meningitis in newborn children (less than 1 month of age) have been reported; one was associated with a pet cat stealing a baby’s pacifier and using it as a toy, and the other was associated with a pet dog that often licked the baby’s face…

“A 48-year-old man with diabetes and his wife had recurrent MRSA infections. Culture of nares samples from the family dog grew mupirocin-resistant MRSA that had a PFGE chromosomal pattern identical to the MRSA isolated from ...

Don’t Forget About the Other Type of Malaria—It’s Getting Worse

Douglas Main — Wed, 07 Dec 2011 13:30:42 +0000

Incidence of malaria-causing Plasmodium vivex worldwide. Red indicates local
infection rates greater than 7 percent; Light blue: one percent. More about map here.

When most people think of malaria, they usually think of its most deadly variety, caused by the parasite Plasmodium falciparum, the form most prevalent in Africa. But it’s not the only one: a second type, Plasmodium vivax, is a growing and overlooked disease in Southeast Asia and elsewhere in the world. More resources may need to be devoted to halt it’s spread, say researchers who presented the first comprehensive map of the disease’s worldwide prevalence Tuesday at the ongoing annual meeting of the American Society for Tropical Medicine and Hygiene in Philadelphia. Currently 97 percent of malaria-eradication funds are focused on P. falciparum, Oxford University researcher Peter Gething tells Nature News.

But Plasmodium vivax may cause as many as 40 percent of the 400 million cases of malaria each year, and is the predominant form of malaria in South America, India, and Southeast Asia, according to researcher Andrew Bright. The disease has also shown resistance to primaquine, currently the only licensed drug capable of a radical cure. Presentations by Bright, Gething, and others challenge ...

Consumer Reports Finds Excessive Arsenic & Lead In Apple & Grape Juices

Douglas Main — Tue, 06 Dec 2011 14:58:38 +0000

A new study by Consumer Reports found arsenic levels that exceed federal drinking water standards in 10 percent of the apple and grape juices tested. The group also found excessive levels of lead in 25 percent of grape and apple juices. Arsenic and lead are both poisonous and can cause health problems, especially in pregnant women, infants, and young children. Kids drink a lot of juice—more than one-third drink more than recommended by pediatricians. Although there is no technical limit for these chemicals in most juices and foods, these levels found in five brands exceed the 10 parts per billion allowed in drinking water for arsenic and the 5 ppb allowed for lead (find detailed information about individual brands tested here in a PDF). Consumer Union, Consumer Reports’ advocacy arm, called for the Food and Drug Administration to establish maximal safe levels for these contaminants in juices. Several studies suggests that chronic exposure to arsenic and lead—even at levels below water standards—can result in serious health problems, the group said.

The topic of arsenic is juice has been in the news since Mehmet Oz, M.D., host of “The ...

A Sleeping Pill Awakens Some Minimally Conscious Patients

Valerie Ross — Mon, 05 Dec 2011 20:32:43 +0000

Doctors long believed that patients who remained in a coma weeks or more after a brain injury would never regain consciousness. But recent research has shown that consciousness isn’t a binary, awake-or-not state; it’s a spectrum. While some brain injury patients are in a vegetative state, without any conscious awareness, others are in what’s called a minimally conscious state, still partially aware of—and at times even able to respond to—their surroundings. From the outside, it can be difficult to tell the two apart, though new methods, such as EEGs that pick up on subtle differences in brain waves, are starting to help clinicians gauge a patient’s level of consciousness.

From these hinterlands of consciousness comes another astounding—and mysterious—discovery: Ambien, the prescription sleep medication, and zolpidem, the drug’s generic form, can help some minimally conscious patients wake up. Jeneen Interlandi delves deep into this seemingly paradoxical treatment in the New York Times magazine:

The first report of a zolpidem awakening came from South Africa, in 1999. A patient named Louis Viljoen, who, three years before, was declared vegetative after he was hit by a truck, had taken to clawing at ...

The Middle Class, Not the Poor, Eat the Most Fast Food

Veronique Greenwood — Mon, 05 Dec 2011 18:29:47 +0000

As income rises, the frequency of fast food visits rise as well, at least until income hits $60,000 a year; sit-down restaurant visits just keep on rising. (The y axis is frequency of visits.)

Obesity rates in the United States are highest among the poor, and high up on most lists of reasons why, you’ll find the truism that fast food is cheap food, and the poor, who can’t afford healthier fare, are its main consumers. A new study suggests, however, that the people eating the most fast food are middle class, with incomes as high as $60,000 a year. Using a national database of about 5,000 people, researchers at UC Davis found that the frequency of people’s visits to fast-food restaurants increased with rising household income until $60,000, when frequency started to go down (though, interestingly, people making more than $100,000 still went to fast food more than those making $20,000). Visits to sit-down restaurants, on the other hand, increased with rising income and just kept on growing.

The research indicates that ascribing a fast-food habit to the poor alone ignores the rest of the population’s predilections and may be a distraction from ...

More Fun Than a Blood Test: Researchers Want Diagnosis To Be as Simple as Spitting On Your Screen

Valerie Ross — Mon, 05 Dec 2011 17:24:17 +0000

What’s the News: If two South Korean researchers have their way, the days of needing specialized equipment to test whether someone has strep, the flu, or other common illnesses may soon be numbered. The pair want to check for disease markers in a tiny drop of a bodily fluid by pressing it against a touchscreen, so your diagnosis could come straight from your smart phone. While there’s no app for that yet, the scientists recently finished a proof-of-concept study showing that a touchscreen could differentiate between various concentrations of bacterial DNA—a first step towards diagnosing your disease by spitting on your iPad.

How the Heck:

Touchscreens like those in smartphones and tablets work by detecting changes in capacitance, or how much electric charge a material can store. When you’re using your phone, the touchscreen senses the relatively large capacitance change of fingertip vs. no fingertip. But, the researchers knew, touchscreens can detect much smaller differences. Using screens to measure the capacitance of a bodily fluid droplet could reveal the sample’s contents, they hypothesized, since the type and amount of a pathogen would change a fluid’s capacitance in a particular way. To test ...

Study: Vaccines & Hand-Washing Can Reduce Prejudice Against Immigrants, the Obese & Crack Addicts

Douglas Main — Mon, 05 Dec 2011 16:30:00 +0000

The war between people and disease-causing pathogens is old as humanity itself. This has helped shaped our so-called behavioral immunity, which can lead us, for example, to automatically avoid people who are visibly sick. But it can also misfire; previous studies have shown that people with compromised immune systems (due to a recent illness), and even people who describe themselves as afraid of germs or susceptible to disease, are more likely to avoid and feel prejudiced toward otherwise healthy people who merely look different than them, like foreigners or immigrants.

It appears this prejudice can be reduced or erased by public health measures like vaccination or the simple act of washing your hands, according to a recent study in Psychological Science. In the study’s first experiment, conducted at the height of the 2009 H1N1 swine flu, researchers gathered a group of participants, some of whom had already received a vaccine against H1N1. They were then randomly broken into two groups, which I’ll call group A and group B (each had roughly equal numbers of vaccinated and non-vaccinated people). Group A read news articles describing the flu’s health effects and ...

Medical Marijuana Laws Decrease Traffic Deaths? Pull Out Your Critical Thinking Skills

Veronique Greenwood — Fri, 02 Dec 2011 19:02:10 +0000

If you remember anything from statistics class, it’s probably that correlation ain’t no causation. Just because two numbers happen to go up at the same time doesn’t mean that one is causing the other to rise (or fall, or hold steady, or whatever). If there isn’t a plausible explanation for how the two might be connected, and proof that that explanation is indeed the cause, all you have is a couple of lines on a chart.

So it’s a move in the right direction when people try to suss out connections between two variables they have a hunch are related. But seeking such a connection can lead to some pretty convoluted reasoning. A new paper—unpublished, but released for discussion—claims that the passage of states’ medical marijuana laws cause decreased traffic fatalities, following on the researchers’ intuition that people might smoke pot instead of drinking alcohol if marijuana were more readily obtainable, and that driving while high is less dangerous than driving drunk. Their logic goes like this: if medical marijuana laws make pot more easily available, and people smoke more pot after laws are passed, and they buy less alcohol because of that, then there would ...

Instead of an HIV Vaccine, What About HIV Gene Therapy?

Veronique Greenwood — Thu, 01 Dec 2011 21:28:05 +0000

Vaccines usually work by getting the body to make antibodies against a virus, so when the virus appears on the scene, the immune system is prepared to tag it for destruction. But getting the body excited about making such antibodies isn’t always easy. It’s this stumbling block that has made HIV vaccines so disappointing so far, and in response, some scientists have reached for the big guns of biology. In a paper published today in Nature, one team reports that they’ve been able to make mice immune to HIV using, of all things, gene therapy.

Best known as a process for replacing faulty genes with fresh ones to treat chronic diseases, gene therapy seems, at first glance, like overkill. It involves engineering a lab-grown virus to permanently insert a gene into a patient’s genome, and it can be dicey, to say the least. Despite two decades of research, no gene therapy treatments have made it out of clinical trials. But given the difficulty of getting the immune system to buckle down and make antibodies against HIV on its own, using gene therapy starts to make a kind of sense.

In this study, the ...

New Tool Detects Photoshop Shenanigans in Fashion Photos

Veronique Greenwood — Tue, 29 Nov 2011 19:28:57 +0000

An image analyzed by the researchers, before retouching, after retouching, with an overlay that shows the strongest retouching in red, and with two facial overlays showing other measures of retouching.

What’s the News: It’s not news that in the age of Photoshop, celebrities and models in magazines have started to look like perfect aliens crash-landed among we ugly Earthlings. But though sometimes it’s obvious when a photo editor has gone too far (witness the Ralph Lauren her-head’s-bigger-than-her-pelvis debacle), the gap between what real people look like and what magazines and other media regularly show has grown distressingly wide without most people consciously noticing it, creating a sea of misinformation that may contribute to body-image disorders.

An analytical tool developed by Dartmouth scientists, though, picks up and quantifies those alterations, potentially providing a useful metric for policymakers looking to set boundaries on how much limb-stretching, torso-trimming, face-smoothing alteration is appropriate.

How the Heck:

The tool rates altered images on the basis of geometric change, like stretching and shrinking, and photometric changes, like airbrushing and heightened colors. To test their system, the researchers had 390 volunteers from Amazon’s Mechanical Turk service analyze 468 photos before and after retouching, most ...

Americans Heavier Than Ever, But Most Still Say Their Weight Is “About Right”

Douglas Main — Tue, 29 Nov 2011 14:54:30 +0000

A Gallup poll reports that on average Americans weigh almost 20 pounds more than they did in 1990, based on the self-reports of more than 1,000 people. The average man weighs 196 pounds while the average woman is 160 pounds. And most of us—62 percent—are already overweight or obese.

But that doesn’t mean we’re ready to come right out and admit it, at least not to a telephone pollster. When asked how they would describe their own weight, only 39 percent of Americans described themselves as “overweight,” while 56 percent reported their weight was “about right.” Neither of these metrics have changed very much since the poll was first given 21 years ago.

At the same time, 59 percent say they’d like to lose weight [PDF]. At first this seems to contradict the “about right” result, but it can probably be explained by people’s reluctance to describe themselves as “overweight,” even if many admit a desire to be thinner. According to last year’s poll, about 27 percent of Americans are actively trying to lose weight (apparently this question wasn’t asked this year). If we want to stop rising levels of obesity in ...

Study: Over Time, Even a Little Too Much Tylenol Can Kill

Douglas Main — Thu, 24 Nov 2011 13:47:14 +0000

When it comes to acetaminophen (aka Tylenol or paracetamol), taking slightly too much for a few days may be more deadly than taking way too much all at once. A study in the British Journal of Clinical Pharmacology found that a quarter of the 663 patients admitted to the Scottish Liver Transplant Unit since 1992 suffered liver failure after a “staggered overdose,” in which people took a couple extra doses of acetaminophen for several days. 37 percent of patients with staggered overdoses died or required a liver transplant, compared to 28 percent of those with single overdoses.

The average single overdose was 27 grams, or 54 Extra Strength Tylenols (500 mg each). A staggered overdose was defined as an average of 4 grams per day (8 extra strength pills). Although such an overdose can even occur after one day, the average staggered overdose patient consumed a total of 24 grams.

The chemical used to treated acetaminophen poisoning, N-acetyl cysteine, is meant to protect the liver from the damage of a single overdose, and is unlikely to help patients with staggered overdoses, the researchers write. By the time these patients reach the ...

Rabbits Wear 1st Augmented Reality-Style Contact Lenses. Resolution: 1 Pixel

Valerie Ross — Tue, 22 Nov 2011 18:22:47 +0000

Bionic contact lenses—which would display navigation data, personal emails, or any other sort of info superimposed on the world before your eyes—have long been mainstays of science fiction. Over the past several years, researchers have been working to make the tech real-world ready, striving to find solutions to the energy, size, safety, and image-quality problems that come up when you’re trying to fit a tiny integrated circuit into something transparent that sits on an eyeball.

Now, University of Washington researchers and their Finnish colleagues have made the first functioning bionic lens: a prototype with a single LED pixel, which could be safely worn by rabbits in the lab. (The image at right shows a rabbit wearing an earlier version of the lens, which contained a circuit but no light-emitting components.) Radio frequency energy emitted from a nearby transmitter and picked up by a circular antenna a fifth of an inch in diameter, printed on the lens, powered the electronics. The transmitter supplied adequate energy from three feet away when the lens was sitting in a dish, but had to be less than an inch away when the lens was ...

DARPA: Let’s Get Rid of Antibiotics, Since They’ll Be Obsolete Anyway

Valerie Ross — Tue, 22 Nov 2011 16:50:19 +0000

For the better part of a century, antibiotics have given doctors great powers to cure all sorts of bacterial infections. But due to bacteria’s nasty habit of evolving, along with widespread overuse of these drugs, disease-causing bacteria are evolving antibiotic resistance at an alarming rate, making it much harder, and at times impossible, to wipe them out. DARPA, the military’s research agency, is eyeing an innovative solution to the problem: Rather than struggling to make better antibiotics, ditch them altogether. It may be time to start killing bacteria a whole new way.

The agency issued a call for proposals to develop a system of bacteria-beating drugs based on siRNAs, tiny scraps of genetic material that turn genes on and off. The idea is to hitch siRNAs onto a nanoparticle, which can make its way into the bacterial cell. What’s more, DARPA wants siRNAs ”whose sequence and objective can be reprogrammed ‘on-the-fly’ to inhibit multiple targets within multiple classes of pathogens,” meaning they can be easily tweaked and tailored in the lab to combat a new bacteria or virus, be it a naturally emerging disease or a carefully designed bioweapon.

DARPA is ...