Archive for the ‘medicine’ Category

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)

Researchers grow a placenta in a petri dish

December 4th, 2018
Fetus in the womb, computer artwork.

Enlarge / Fetus in the womb, computer artwork. (credit: Science Photo Library - SCIEPRO)

The placenta supports the fetus while it is in utero (and, according to some, a placental can support a rosebush if it's buried under one after delivery).We know a placenta is essential for a successful pregnancy, but we don’t really know exactly how it works because we’ve had no experimental models we can use to study it. Until now.

Researchers in England examined all of the signaling molecules they could find rushing around between the mother and the placenta (which originates from fetal tissue), figuring they might induce the placenta to grow and develop. From this analysis they generated a blend of signaling molecules that they expected could induce placental formation in a culture dish.

They then obtained cells from first trimester placentas from women who had had normal pregnancies but decided to abort. These cells were grown in media that contained the factors identified by this team. Within a week, the cells were growing into organoids—small blobs of tissue similar to organs in mature organisms. The cells seem perfectly happy in this media; at the time this paper was written, they have been stable for a year.

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Posted in Biology, embryology, medicine, science | Comments (0)

The fight against measles has taken a turn for the worse

November 30th, 2018
A baby hospitalized with measles in the Philippines, in an outbreak following 2013's typhoon Haiyan.

Enlarge / A baby hospitalized with measles in the Philippines, in an outbreak following 2013's typhoon Haiyan. (credit: CDC Global)

In 2010, the World Health Organization (WHO) set some ambitious goals for measles worldwide. By 2015, they wanted to reduce the number of deaths caused by measles by 95 percent compared to 2000. They set similarly ambitious targets for vaccination rates and measles infections.

The world has not reached these goals. And between 2016 and 2017, there was an alarming uptick in measles cases worldwide, according to a joint report by the WHO and CDC. “Complacency about the disease and the spread of falsehoods about the vaccine in Europe, a collapsing health system in Venezuela, and pockets of fragility and low immunization coverage in Africa are combining to bring about a global resurgence of measles after years of progress,” said Dr Seth Berkley, CEO of Gavi, the Vaccine Alliance, in a statement about the report.

Overall, between 2000 and 2017, there has been a lot of progress: annual global deaths have decreased 80 percent, from 545,174 to 109,638. Over this time period, measles vaccination has prevented approximately 21 million deaths globally, compared to a hypothetical world with no measles vaccines (in this world, the death rate would have been a lot higher in 2000, too). The number of cases reported annually plummeted from 145 cases per million people to just 25—although the goal was five cases per million. And 85 percent of people globally had received the first dose of the measles vaccine in 2017, compared to 72 percent in 2000.

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

Scientists, ethicists slam decisions behind gene-edited twins

November 30th, 2018
Chinese geneticist He Jiankui speaks during the Second International Summit on Human Genome Editing at the University of Hong Kong days after the Chinese geneticist 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 the Chinese geneticist 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)

As more details regarding the first gene-edited humans are released, things continue to look worse. The researcher who claimed the advance, He Jiankui, has now given a public talk that includes many details on the changes made at the DNA level. The details make a couple of things clear: we don't know whether the editing will protect the two children from HIV infections, and we can't tell whether any areas of the genome have been damaged by the procedure.

All of that raises even further questions as to whether He followed ethical guidelines when performing the work and getting consent from the parents. And, more generally, nobody is sure why He chose to ignore a strong consensus that the procedure wasn't yet ready for use in humans. In response to the outcry, the Chinese government has shut down all further research by He, even as it was revealed that a third gene-edited baby may be on the way.

While the US already has rules in place that are intended to keep research like He's from happening, a legal scholar Ars spoke with suggested there may be a loophole that could allow something similar here. In light of that, it's important to understand the big picture He has potentially altered. What exactly happened in China and why does it concern so many in the scientific community?

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Posted in Biology, CRISPR, ethics, Features, gene editing, medicine, science, stem cells | Comments (0)

US life expectancy continues to move in reverse

November 29th, 2018
Cemetry in Craftsbur in Autumn Season, Common, Vermont, New England

Enlarge / Cemetry in Craftsbur in Autumn Season, Common, Vermont, New England (credit: Enn Li Photography | Getty Images)

In 1900, the average person in the US could expect to live just 47.3 years. Throughout the 20th century, that figure climbed rapidly, topping 70 years for the first time in 1961 and reaching 78.9 years in 2014, suggesting 80 was only a matter of time.

Then in 2015, there was a downturn—a small one, to 78.8 years. A single year might be a blip, but the reasons for the increase in death rate (including obesity and drug overdoses) suggested that might not be the case. Data released today by the CDC’s National Center for Health Statistics points to a continuing downward trend: life expectancy in 2017 was 78.6 years, down from 78.7 years in 2016.

That dip of 0.1 years, every year for the last three years, is not a huge trend when taken on its own. But it suggests that the decrease in 2015 was more than a blip—and it points to unfolding stories about health and death in the United States. Those small-seeming numbers also translate to meaningful real-world figures: there were 69,255 additional deaths in 2017 compared to 2016.

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Posted in Health, life expectancy, medicine, science | Comments (0)