Blood

A Blood Test May Help Pinpoint the Right Antidepressant for You

When doctors determine the best medication for a person with depression, they generally rely upon little more than guesswork and patient self-reports, due to insufficient medical evidence. Research out of UT Southwestern Medical Center (UTSMC) previously suggested that such practices were insufficient, and a new study, published in Psychoneuroendocrinology, provides additional diagnostic information that may change the way depression is treated.

The research team drew upon a large body of research that links low levels of inflammation in the body with depression. They say a blood test for an inflammatory biomarker, known as C-reactive protein (CRP), can significantly improve the success rate of two common antidepressants for depressed patients.

Lead author Madhukar Trivedi, a professor of psychiatry at UTSMC and director of the Center for Depression Research and Clinical Care, says doctors typically pick an antidepressant for their patients in one of three ways: personal experience; matching the perceived benefits of one drug with a certain type of patient’s needs; or having the patient pick a drug by ruling out the unwanted side effects of other drugs. “There isn’t a strong evidence base to support one way [of choosing an antidepressant] over another,” he tells mental_floss.

Trivedi says that because many doctors are pressed for time and overloaded with patients, they don’t thoroughly address a depressed patient’s needs. “If you have diabetes, the doctor spends a lot of time explaining that it’s a serious illness—there are consequences for ignoring it, and there are treatments you need to do. In depression, that does not happen as much. Patient engagement is not that strong,” he says.

Trivedi led a landmark study more than a decade ago that revealed how serious the medication problem is: Up to one-third of depressed patients don’t see an improvement in their first month of medication,…

Immune cells play surprising role in steady heartbeat

macrophages and heart cells
IT’S ELECTRIFYING Macrophages (green) “plug in” to heart cells (light purple and pink), providing an electrical boost that helps the heart cells contract and pump blood, a study in mice finds.

Immune system cells may help your heart keep the beat. These cells, called macrophages, usually protect the body from invading pathogens. But a new study published April 20 in Cell shows that in mice, the immune cells help electricity flow between muscle cells to keep the organ pumping.

Macrophages squeeze in between heart muscle cells, called cardiomyocytes. These muscle cells rhythmically contract in response to electrical signals, pumping blood through the heart. By “plugging in” to the cardiomyocytes, macrophages help the heart cells receive the signals and stay on beat.

Researchers have known for a couple of years that macrophages live in healthy heart tissue. But their specific functions “were still very much a mystery,” says Edward Thorp, an immunologist at Northwestern University’s Feinberg School of Medicine in Chicago. He calls the study’s conclusion that macrophages electrically couple with cardiomyocytes “paradigm shifting.” It highlights “the functional diversity and physiologic importance of macrophages, beyond their role in host defense,” Thorp says.

Matthias Nahrendorf, a cell biologist at Harvard Medical School, stumbled onto this electrifying find by accident.

Curious about how macrophages impact the heart, he tried to perform a cardiac MRI on a mouse genetically engineered to not have the immune cells. But the rodent’s heartbeat was too slow and irregular to…

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…