Blood plasma

Brain gains seen in elderly mice injected with human umbilical cord plasma

mouse hippocampus
YOUTHFUL GLOW In the hippocampus of a 1-month-old mouse, some nerve cells (red) produce the protein TIMP2 (green), which declines with age and may help keep the brain young. Blue indicates microglial cells.

Plasma taken from human umbilical cords can rejuvenate old mice’s brains and improve their memories, a new study suggests. The results, published online April 19 in Nature, may ultimately help scientists develop ways to stave off aging.

Earlier studies have turned up youthful effects of young mice’s blood on old mice (SN: 12/27/14, p. 21). Human plasma, the new results suggest, confers similar benefits, says study coauthor Joseph Castellano, a neuroscientist at Stanford University. The study also identifies a protein that’s particularly important for the youthful effects, a detail that “adds a nice piece to the puzzle,” Castellano says.

Identifying the exact components responsible for rejuvenating effects is important, says geroscientist Matt Kaeberlein of the University of Washington in Seattle. That knowledge will bring scientists closer to understanding how old tissues can be rejuvenated. And having the precise compounds in hand means that scientists might have an easier time translating therapies to people.

Kaeberlein cautions that the benefits were in mice, not people. Still, he says, “there is good reason to be optimistic that some of these approaches will have similar effects on health span in people.”

Like people, as mice age, brain performance begins to slip. Compared with younger generations, elderly mice perform worse on some tests of learning and memory, taking longer to remember the location of an escape route out of a maze, for instance. Researchers suspect that these deficits come from age-related trouble in the hippocampus, a brain structure important for learning and memory.

Every fourth day for two weeks, Castellano and colleagues injected old mice with human…

Scientists turn toy into valuable tool for medical diagnosis

paper centrifuge
paper centrifuge

Medical lab equipment often showcases high-tech at its best. Devices can perform complicated tasks, such as separating blood into its parts, quickly and easily. But these machines often are difficult — even impossible — to use in poor countries or at remote field clinics. Often expensive and bulky, they tend to require training to use. And most are powered by electricity. But researchers have just unveiled a simple, low-cost human-powered device useful for medical diagnoses. It can separate blood into its different parts.

Best of all, it’s so simple a child could run it. Indeed, it is based on a toy that’s been around for thousands of years.

Manu Prakash is a bioengineer at Stanford University in California. There, he designs medical devices that can be used easily by anyone anywhere in the world. A few years back, his team invented a microscope made largely of paper that costs less than a dollar to make.

On a trip to the East African nation of Uganda, a few years ago, Prakash was surprised to see an expensive centrifuge being used as a doorstop. Medical labs use these devices to separate liquid mixtures, such as blood or muddy water, into their different components. Based on what they learn from those components, doctors will tailor a patient’s treatment.

But the clinic did not have electricity. So no one could use this machine.

centrifuge machine
This centrifuge can separate blood or other liquids into their various parts to aid in disease diagnosis. But these machines are costly and need electrical power. And that can prevent their use in many poorer parts of the world.

The key part of a centrifuge is its rapidly rotating interior. Think of it as a small version of a top-loading washing machine. In a centrifuge, though, the interior chamber spins faster than the parts in a car’s engine. Anything inside a spinning centrifuge experiences a force that slings it away from the center of rotation and toward the device’s rim. This is similar to how wet clothes in the washer get squished against the inside wall of the drum during the spin cycle.

When a centrifuge spins a test tube of blood to separate out its various parts, the vial is loaded in with its base pointing outward. Rotation forces outward the densest parts of the blood — platelets and blood cells. Lighter parts, such as the fluid or plasma, stay on top. Doctors or lab technicians can then separate each layer for tests that guide treatment. Without a centrifuge, such tests become difficult, if not impossible.

The centrifuge that had become an expensive doorstop inspired Prakash’s team to invent something that could serve the same purpose. Their device would have to spin very quickly. It would have to be cheap to make and easy to use. And it would have to run without electricity.

Previously, Prakash notes, people had suggested employing kitchen devices as a low-cost centrifuge, such as an egg beater or handheld mixer. But these tools could…