How to build a human cell atlas – Nature

photo by Casey Atkins for Nature

Aviv Regev likes to work at the edge of what is possible. In 2011, the computational biologist was collaborating with molecular geneticist Joshua Levin to test a handful of methods for sequencing RNA. The scientists were aiming to push the technologies to the brink of failure and see which performed the best. They processed samples with degraded RNA or vanishingly small amounts of the molecule. Eventually, Levin pointed out that they were sequencing less RNA than appears in a single cell.

To Regev, that sounded like an opportunity. The cell is the basic unit of life and she had long been looking for ways to explore how complex networks of genes operate in individual cells, how those networks can differ and, ultimately, how diverse cell populations work together. The answers to such questions would reveal, in essence, how complex organisms such as humans are built.

Read the full story in Nature.

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What will it take to 3-D print organs? – NeoLife

Sebastian Kaulitzki/Shutterstock; Scientific Reports

Every day in the U.S., about 22 people die waiting for an organ transplant. If scientists could 3-D print organs like kidneys, livers and hearts, all those lives could be saved. For years, people have been touting personalized organ printing as the future.

But despite decades of promising work in bioengineered bladders and other kinds of human tissue, we’re not close to having more complicated organs made from scratch. Harvard professor Jennifer Lewis, a leader in advanced 3-D printing of biological tissue, has only recently developed the ability to print part of a nephron, an individual unit of a kidney.

I asked Lewis what it will take to someday print a full kidney or a similarly complex organ.

Read the full story in NeoLife.

Arkansas should halt execution spree and let its drugs expire – New Scientist

Reuters

An unprecedented scheduled execution spree has begun this week in Arkansas. The state initially aimed to carry out the death sentence on eight people in 11 days before its stockpile of one of the three drugs used for lethal injections, called midazolam, reached its expiry date of 30 April.

Last night, legal hurdles were overcome in one case and the first execution took place. Arkansas should have let the midazolam expire. In fact, it shouldn’t have used it at all.

Whatever you think of capital punishment, the drugs used for lethal injection in the US today don’t offer the certainty of a swift end, because of a horrifying combination of a lack of data, historical quirks and uninformed decision-makers.

Read the full story in New Scientist.

Take two placebos and call me in the morning – NeoLife

Illustration by Gabriel Alcala

When a new drug is being tested in a controlled clinical trial, half the patients get the real drug and half get a placebo, something harmless like a sugar pill or a saline injection. But patients on the placebo often improve anyway, and that’s because they expect that they’re getting the real drug, right? Well, no. Harvard professor Ted Kaptchuk’s research has exploded that explanation. Read the full story in NeoLife.

New method taps family trees for clues about conditions – Spectrum

Genetic puzzle: A new approach for finding risk variants considers data from multiple generations of a family. Hero Images/Getty Images

Asking participants in genetic databases about their family’s medical history can help researchers uncover genetic variants tied to uncommon conditions. Because people share 50 percent of their DNA with each of their parents, siblings and children, the DNA of the participants holds clues to the conditions of these relatives.

Read the full story in Spectrum.