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Scientists Sequence DNA of Century-Old Pediatric Tumors

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In a development that may lead to better treatments for modern-day childhood cancers, researchers have found a way to reveal the genetics of tumor samples dating back to the 1920s. The team published their findings in The Lancet.

The good thing about rare childhood cancers is that they’re rare, which means that few children will get them. But the bad thing is that that same rarity produces very few samples, which makes them harder to study, which in turn makes them near-impossible to treat with any scientific confidence.

“The treatment regimens for children with rare cancers are essentially made up,” lead author Sam Behjati of the Wellcome Trust Sanger Institute told Nature. “If you’ve got three or four patients nationally, how are you ever going to conduct a reasonable clinical trial?”

The ideal situation—more tumor samples but fewer sick kids—may be less paradoxical than it sounds, as Behjati and his colleagues have figured out a way to grab genetic information from old tissue samples. And when we say old, we mean really old.

The Great Ormond Street Hospital for Children in London—which was saved from closure shortly after it opened thanks to a fundraiser by Charles Dickens—has been collecting samples from young patients since the mid-19th century, long before we had the technology to preserve them in any useful way. Then, in the early 20th century, scientists started dousing their samples in a chemical called formalin and embedding them in paraffin wax. The technique worked so well that researchers still use formalin-fixed paraffin-embedding (FFPE) today.

DNA is delicate stuff, and it tends to fall apart over time. Previous researchers have had some luck extracting DNA from FFPE tissue samples, but the oldest of these was only 32 years old.

The authors of the recent paper wondered if they could sample older specimens. They pulled three potential tumor samples from the hospital’s archives dating to the 1920s. One had been tentatively diagnosed as a lymphoma; one as a skeletal muscle cancer called rhabdomyosarcoma; and another as a blood-vessel tumor called cellular capillary hemangioma.

They scraped a tiny bit of tissue from each and ran them through a comprehensive genetic sequencing program.

The old-school preservation technique had done its job “remarkably,” the authors write, and each old sample’s genetic code matched the profile of its modern-day counterpart. This development “paves the way” for studying rare tumors, they say, and could shed light on the long-ago mutations that led to the cancers we face today.

[h/t Nature]

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Lincoln’s Famous Letter of Condolence to a Grieving Mother Was Likely Penned by His Secretary
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Despite his lack of formal schooling, Abraham Lincoln was a famously eloquent writer. One of his most renowned compositions is the so-called “Bixby letter,” a short yet poignant missive the president sent a widow in Boston who was believed to have lost five sons during the Civil War. But as Newsweek reports, new research published in the journal Digital Scholarship in the Humanities [PDF] suggests that Lincoln’s private secretary and assistant, John Hay, actually composed the dispatch.

The letter to Lydia Bixby was written in November 1864 at the request of William Shouler, the adjutant general of Massachusetts, and state governor John Albion Andrew. “I feel how weak and fruitless must be any word of mine which should attempt to beguile you from the grief of a loss so overwhelming,” it read. “But I cannot refrain from tendering you the consolation that may be found in the thanks of the Republic they died to save.”

Unknown to Lincoln, Bixby had actually only lost two sons in battle; the others had deserted the army, were honorably discharged, or died a prisoner of war. Nevertheless, word of the compassionate presidential gesture spread when the Boston Evening Transcript reprinted a copy of the 139-word letter for all to read.

Nobody quite knows what happened to Bixby’s original letter—some say she was a Confederate sympathizer and immediately burnt it—but for years, scholars debated whether Hay was its true author.

During Hay’s lifetime, the former secretary-turned-statesman had reportedly told several people in confidence that he—not Lincoln—had written the renowned composition, TIME reports. The rumor spread after Hay's death, but some experts interpreted the admission to mean that Hay had transcribed the letter, or had copied it from a draft.

To answer the question once and for all, a team of forensic linguists in England used a text analysis technique called n-gram tracing, which identifies the frequency of linguistic sequences in a short piece of writing to determine its true author. They tested 500 texts by Hay and 500 by Lincoln before analyzing the Bixby letter, the researchers explained in a statement quoted by Newsweek.

“Nearly 90 percent of the time, the method identified Hay as the author of the letter, with the analysis being inconclusive in the rest of the cases,” the linguists concluded.

According to Atlas Obscura, the team plans to present its findings at the International Corpus Linguistics Conference, which will take place at England’s University of Birmingham from Monday, July 24 to Friday, July 28.

[h/t Newsweek]

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These Deep-Sea Worms Could Live More Than a Thousand Years

Plunge below the sparkling surface of the Gulf of Mexico, head down into the depths, and there you'll find the ancient ones, growing in clusters of drab tubes like piles of construction equipment. Scientists writing in the journal The Science of Nature report that some of these worms could be more than 1000 years old.

When it comes to marine organisms, the deeper you go, the slower and older life gets. Biologists have found an octopus that guarded her eggs for four and a half years. They've seen clams born during the Ming dynasty and sharks older than the United States. They've seen communities of coral that have been around for millennia.

Previous studies have shown that some species of tube worm can live to be 250 years old. To find out if the same was true for other species—in this case, the Gulf of Mexico's Escarpia laminata—researchers spent years watching them grow. They used a long-lasting dye called Acid Blue to mark six clusters of worms, then let them to go about their wormy business. A year later, they collected all 356 blue-stained tubes and brought them back to the lab to measure their growth.

By calculating the speed of the worms' growth and comparing it to the size of the largest individuals, the scientists could devise a pretty good estimate of the oldest worms' age.

And boy, are they old. The researchers' worm-growth simulation suggested that the most ancient individuals could be more than 9000 years old. This seems incredible, even for tough old tube worms, so the scientists calculated a more conservative maximum age: a mere 1000 years.

A millennium-long lifespan is an extreme and not the average, the paper authors note. "There may indeed be large E. laminata over 1000 years old in nature, but given our research, we are more confident reporting a life span of at least 250 to 300 years," lead author Alanna Durkin of Temple University told New Scientist.

Still, Durkin says, "E. laminata is pushing the bounds of what we thought was possible for longevity."

She's excited by the prospect of finding older creatures yet.

"It's possible that new record-breaking life spans will be discovered in the deep sea,” she says, “since we are finding new species and new habitats almost every time we send down a submersible.”

 

[h/t New Scientist]

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