Archive for the ‘medicine’ Category

Medical marijuana vs. opioid abuse: New study questions the connection

June 13th, 2019
Legal cannabis for sale in a tobacco shop in Italy.

Enlarge / Legal cannabis for sale in a tobacco shop in Italy. (credit: Stefano Guidi | Getty Images)

In the US, federal law has severely restricted our ability to study any potential medical properties of cannabis. But, given some limited studies and a lot of anecdotal stories, a number of states have gone ahead and legalized medical marijuana. This has allowed some population-level studies of what's going on in the states, but those have faced additional complications, like rules that differ from state to state and an ongoing legalization of recreational use confusing the picture.

Just how confusing all this can be was driven home this week by the release of a paper that suggests that one of medical marijuana's greatest successes was illusory. A couple of early studies indicated that states that had legalized medical marijuana use saw drops in opioid-related deaths. The new research replicates those results but finds that the trend has reversed in recent years, with those states now seeing increased deaths. While the new study's authors suggest the initial results were spurious, others suggest that the shifting legal landscape and changes in drug abuse may have driven the change.

What does everyone agree upon?

Back in 2014, researchers compared deaths due to opioid abuse in states with and without legalization of medical marijuana. For the decade prior to 2010, the trend was clear: states that allowed medical marijuana had lower rates of opioid-abuse-driven death.

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Posted in Biology, epidemiology, Medical Marijuana, medicine, opioids, Policy, science | Comments (0)

Target of first human gene editing cuts life expectancy short

June 5th, 2019
Chinese geneticist He Jiankui speaks during the Second International Summit on Human Genome Editing at the University of Hong Kong days after he claimed to have altered the genes of the embryo of a pair of twin girls before birth, prompting outcry from scientists of the field.

Enlarge / Chinese geneticist He Jiankui speaks during the Second International Summit on Human Genome Editing at the University of Hong Kong days after he claimed to have altered the genes of the embryo of a pair of twin girls before birth, prompting outcry from scientists of the field. (credit: S.C. Leung/SOPA Images/LightRocket via Getty Images)

Late last year, a Chinese researcher shocked the scientific community when he announced that the first gene-edited humans had already been born. He Jiankui barreled past an emerging consensus that the technology wasn't ready for use and, once it was, should be reserved for otherwise untreatable diseases. Instead of respecting those boundaries, He did much of his work without any clear institutional oversight.

Rather than target an incurable genetic disorder, He Jiankui focused on something for which we have both preventative measures and treatments: HIV infection. He did so by using CRISPR gene editing to damage a gene that encodes a protein that HIV uses to enter human cells; previous studies have shown that mutations in this gene protect against HIV infection. But the same mutation was already known to make humans more susceptible to other diseases, raising the question of whether the gene editing put its recipients at risk.

That question has now been answered with an emphatic "yes." Researchers have found that adults carrying mutations in the gene see their general mortality rise by 20 percent compared to their peers.

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Posted in Biology, Genetics, Genomics, HIV, medicine, science | Comments (0)

Study: Leonardo da Vinci suffered from “claw hand,” not post-stroke paralysis

May 4th, 2019
Detail from a 16th century drawing depicting an elderly Leonardo da Vinci's damaged right hand. A new study concludes he suffered from "claw hand."

Enlarge / Detail from a 16th century drawing depicting an elderly Leonardo da Vinci's damaged right hand. A new study concludes he suffered from "claw hand." (credit: Museum of Gallerie Dell’Accademia, Venice)

Famed artist and inventor Leonardo da Vinci suffered from a crippled right hand late in life, usually attributed to a stroke. In a new paper in the Journal of the Royal Society of Medicine, two Italian researchers argue that Leonardo more likely suffered from a condition colloquially known as "claw hand." They base their argument on analysis of a 16th century portrait of en elderly Leonardo.

The quintessential Renaissance man was the illegitimate son of a Florentine notary named Piero Frusino di Antonio da Vinci. (His mother, Caterina, was a peasant.) Much of what we know about Leonardo's life comes from the writing of the 16th century painter and historian Giorgio Vasari, in Lives of the Most Excellent Painters, Sculptors, and Architects.

Historians have also studied Leonardo's drawings and his use of "mirror writing" in his journals, concluding he was almost certainly predominantly left-handed, although he was ambidextrous to come extent. For instance, he wrote and drew with his left hand, but never painted with it. Vasari noted that Leonardo in his prime "was physically so strong that ... with his right hand he could bend the ring of an iron door knocker or a horseshoe as if they were lead."

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Posted in art, History, Leonardo da Vinci, medicine, science | Comments (0)

Science and bicycling meet in a new helmet design

April 14th, 2019
Image of a bike helmet cutaway to reveal a green mesh underneath.

Enlarge (credit: Trek)

When we recently did an overview of the evolution of bicycling technology, helmets were barely mentioned. They've been made out of the same materials for decades, and the only improvement they've seen in that time is a more efficient venting layout. But the timing of that article turned out to be propitious because, a few months later, Trek got in touch to let me know it was introducing the first major change in helmet technology in years.

Normally, emails like that are little more than marketing, or failing that, everything's proprietary and can't be talked about. But in this case, Trek promised that there was peer-reviewed science behind the announcement and I'd get the chance to talk to the scientists themselves. A few weeks later, I got the chance to check out the helmets and meet the scientists (though I narrowly missed my chance to shake hands with cycling legend Jens Voigt).

What’s a helmet actually do?

The obvious answer is that helmets are meant to protect your brain when your head experiences an impact. But the more detailed answer requires delving into a little bit of physics. On a simple level, an impact generates force that, if nothing is protecting you, is translated directly to your skull. A helmet's job is to dissipate that force. If a helmet could be arbitrarily large or heavy, this would not be a problem. But cyclists are notoriously picky about their equipment's weight and aerodynamics, which means that a helmet has to do all its redirection of forces in as little space as possible, using light materials.

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Posted in bicycles, head injuries, helmets, materials science, medicine, science | Comments (0)

The soldier who removed his own bladder stone, and other medical history marvels

March 24th, 2019
A patient receiving dental treatment, circa 1892. There were several cases of "exploding teeth" in the 19th century that remain unexplained to this day.

Enlarge / A patient receiving dental treatment, circa 1892. There were several cases of "exploding teeth" in the 19th century that remain unexplained to this day. (credit: Oxford Science Archive/Getty Images)

While researching his 2017 book on the history of heart surgery, medical journalist Thomas Morris perused hundreds of journals from the 19th century. One day, a headline on the page opposite the one he was reading caught his eye: "sudden protrusion of the whole of the intestines into the scrotum." It was a bizarre case from the 1820s, involving a laborer run over by a brick-laden cart. The resulting hernia forced his intestines into his scrotum, and yet the laborer made a full recovery.

Once he got over his initial amused revulsion, Morris was struck by the sheer ingenuity displayed by doctors in treating the man's condition. And he found plenty of other similar bizarre cases as he continued his research, with people surviving truly horrifying injuries—a testament to the resiliency of the human body. "Doctors, even when they had less than a tenth of the knowledge we do today in terms of treating major trauma, could still come up with innovative and ingenious solutions to acute problems," he said.

Many of the most interesting medical cases Morris uncovered are featured in his hugely entertaining compendium of medical oddities, The Mystery of the Exploding Teeth, and Other Curiosities From the History of Medicine. Regular readers of his blog (tagline: "making you grateful for modern medicine") will revel in stories about a sword-swallowing sailor, a soldier who removed his own bladder stone, a man with combustible belches, a woman who peed through her nose, and a boy who inhaled a bird's larynx and started honking like a goose. All are delivered in elegant prose, punctuated with the author's distinctive dry wit. Morris has collected 500 or so of these frequently jaw-dropping cases thus far, and only included 70 or so in the book. So a sequel (or two) isn't out of the question

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Posted in books, Gaming & Culture, History, history of science, medicine, science | Comments (0)

A small molecule drug can block a broad range of flu viruses in mice

March 11th, 2019
A sign on the entrance to a grocery store announces that it is

Enlarge (credit: Mike Mozart / Flickr)

Our bodies are good at generating antibodies that are extremely specific, picking out a single pathogen from a dizzying mix of harmless bacteria and the proteins made by our own cells. But in some cases, that specificity is limiting. Those antibodies will generally pick out a very specific strain of the flu virus, leaving us vulnerable to other strains and the new variants that evolve each season.

Over the past few years, however, it's become apparent that the immune system sometimes gets wildly lucky by generating a single antibody that can neutralize a huge range of viruses. These "broadly neutralizing antibodies" provide a significant protection against viruses that the immune system normally struggles against, like HIV, Ebola, and the flu virus. Mass production of these antibodies might provide a useful therapy, and the hope is that we can incorporate what they tell us into the design of future vaccines for these pathogens.

But some clever researchers have figured out how to use a broadly neutralizing antibody as a tool to design a drug that can block the activity of a large range of flu viruses.

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Posted in antibodies, Biology, chemistry, drug development, Flu virus, immunoloogy, medicine, pharmacology, science | Comments (0)

Treating lymphoma with HIV-resistant stem cells “cures” another patient

March 5th, 2019
A red blob with lots of smaller, red and green blobs attached to it.

Enlarge / Artist's conception of HIV attached to a cell. (credit: Ohio State)

The identification of the HIV virus ultimately led to the development of therapies that specifically target the virus' ability to make new copies of itself. These therapies have radically altered the lives of infected people, turning a often-lethal virus into something that can be managed for decades. But while the treatments control the virus, they don't eliminate it. Infected people still have reservoirs of virus in their bodies, raising the prospect that a drug-resistant strain could ultimately evolve.

There's only a single known case of the virus being eliminated entirely. That patient had a leukemia that could be treated with a blood stem-cell transplant, and his transplant team used cells that carried a mutation that eliminates one of the proteins that HIV uses to attach to cells. Today, researchers are reporting the second instance in which the transplantation of stem cells carrying this mutation has seemingly eliminated a viral infection. Two cases means the time has come to start looking for features in common between the two treatments.

HIV and stem cells

One of the reasons HIV is so difficult to eliminate is that the virus' normal lifecycle includes integrating a copy into the host cell's DNA. Thus, even if all the circulating virus is eliminated, infected cells can just produce more. To eliminate the virus, you'd have to kill every single infected cell in a person's body. A variety of "reservoirs" of HIV-infected cells has been identified; all of the significant ones appear to be in immune cells of one type or another.

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Posted in Biology, HIV, lymphoma, medicine, science, stem cell transplant, stem cells | Comments (0)

Gene editing still has a few bugs in the system

February 19th, 2019
February 7, 2019, Saxony-Anhalt, Halle (Saale): In the genetic engineering monitoring laboratory of the State Office for Environmental Protection of Saxony-Anhalt, Damaris Horn is sipping reaction preparations for the polymerase chain reaction (PCR) in a special cabin.

Enlarge / February 7, 2019, Saxony-Anhalt, Halle (Saale): In the genetic engineering monitoring laboratory of the State Office for Environmental Protection of Saxony-Anhalt, Damaris Horn is sipping reaction preparations for the polymerase chain reaction (PCR) in a special cabin. (credit: Picture Alliance | Getty Images )

Gene editing has been in the news lately due to an ethically reckless experiment in which human embryos were subjected to an inefficient form of gene editing. The subjects, now born, gained uncertain protection from HIV in exchange for a big collection of potential risks. A large number of ethicists and scientists agreed that this isn't the sort of thing we should be using gene editing for.

That response contains an implicit corollary: there are some things that might justify the use of gene editing in humans. Now, a series of papers looks at some reasonable use cases in mice and collectively finds that the technology really isn't ready for use yet.

Use cases

Gene editing will likely always come with a bit of risk; when you're cutting and pasting DNA in millions of cells, extremely rare events can't be avoided. So the ethical questions come down to how we can minimize those risks and what conditions make them worth taking.

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Posted in Biology, gene editing, Genetic diseases, Genetics, medicine, Muscular dystrophy, progeria, science | Comments (0)

Ebola outbreak reaches city of 1 million residents

December 14th, 2018
Ebola treatment center at the Hospital in Beni, North Kivu Province.

Enlarge / Ebola treatment center at the Hospital in Beni, North Kivu Province. (credit: MONUSCO/Alain Coulibaly)

The Ebola outbreak in the Democratic Republic of the Congo has spread to a city of nearly 1 million residents. There are now 30 confirmed cases and 15 deaths in the city of Butembo reported in the latest update provided by the World Health Organization (WHO). The number of cases in the city center is still low, according to Doctors Without Borders, but that number is rising quickly in more outlying districts and suburbs.

The outbreak, which has been going on since August, has so far resulted in 467 confirmed cases and a further 48 probable cases. More than half of the cases have resulted in death (including those of 17 health workers), while 177 patients have recovered, including a newborn baby.

Limited containment

The rate of transmission is beginning to slow down in Beni, a smaller city approximately 36 miles north of Butembo that has the highest number of reported cases so far. But “the outbreak is intensifying in Butembo and Katwa,” writes the WHO, “and new clusters are emerging elsewhere.”

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

A look at the Apple Watch’s ECG, from someone who needs it

December 12th, 2018
A look at the Apple Watch’s ECG, from someone who needs it

When Apple introduced the fourth iteration of its smartwatch, the big new selling point wasn't a feature we typically associate with a watch or any sort of smart device. Instead, the company added a feature that had only recently arrived in the form of specialized consumer devices: an electrocardiograph (ECG), a device made for monitoring the heart's electrical activity.

But the watch was ready before the software was, meaning an examination of the technology wasn't possible in our comprehensive review of the Apple Watch Series 4. Last week, Apple finally enabled the missing features, and we've spent a few days checking them out.

Basic features

People who haven't used the Apple Watch may not realize just how much it's an extension of an iPhone. This includes the heart-monitoring software, which requires an update to both the Watch and iPhone OSes before it will work. (This caused a small bit of confusion when the software wouldn't launch after we upgraded only the watch's OS.) Once the update is done, the Health app on the iPhone will incorporate any ECG data generated using the watch. On the watch side, the update will install a new app.

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Posted in apple watch, arrhythmia, atrial fibrilation, ECG, heart, medicine, science, Tech | Comments (0)