Snapshots of Life: Seeing, from Eye to Brain

Credit: Xueting Luo and Kevin Park, University of Miami

Fasten your seat belts! We’re going to fly through the brain of a mouse. Our tour guide is Kevin Park, an NIH-funded neuroscientist at the University of Miami, who has developed a unique method to visualize neurons in an intact brain. He’s going to give us a rare close-up of the retinal ganglion cells that carry information from the eye to the brain, where the light signals are decoded and translated.

To make this movie, Park has injected a fluorescent dye into the mouse eye; it is taken up by the retinal cells and traces out the nerve pathways from the optic nerve into the brain.

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Cancer Cachexia: Might This Molecule Hold the Key?


Caption: Structure of parathyroid hormone-related protein (PTHrP), which has been implicated in cancer-related cachexia.
Source: The Protein Data Bank

No matter how much high-calorie food they eat or nutritionally fortified shakes they drink, many people with cancer just can’t seem to maintain their body weight. They lose muscle and fat, sometimes becoming so weak that they can’t tolerate further treatment. Called cachexia, this progressive wasting syndrome has long troubled patients and their families, as well as baffled scientists searching for ways to treat or perhaps even prevent it.

Some previous studies [1-3] have observed that humans and mice suffering from cachexia have “activated” brown fat. This type of fat, as I explained in a previous post, has the ability to convert its chemical energy into heat to keep the body warm. Intrigued by these hints, a team led by Bruce Spiegelman of the Dana-Farber Cancer Institute and Harvard Medical School in Boston recently decided to explore whether tumor cells might secrete molecules that spur similar brown fat-like activity, causing a gradual depletion of the body’s energy stores.

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Nanojuice: Getting a Real-Time View of GI Motility

Nanojuice as it passes through the gut of the mouse

Caption: A real-time image of nanojuice as it passes through a mouse’s small intestine. A laser causes particles in the nanojuice to vibrate, creating vibrations picked up by an ultrasound detector that are then used to generate a black-and-white image. Rainbow colors are added afterward to reflect the depth of the intestine within the mouse’s abdomen: blue is closest to the surface and red is deepest.
Credit: Jonathan Lovell, University at Buffalo

For those of you who love to try new juices, you’ve probably checked out acai, goji berry, and maybe even cold-pressed kale. But have you heard of nanojuice? While it’s not a new kind of health food, this scientific invention may someday help to improve human health through its power to visualize the action of the gastrointestinal (GI) tract in real-time.

It’s true that doctors already have many imaging tools at their disposal to examine various parts of the GI tract—all the way from throat to colon. These include invasive techniques, such as upper endoscopy and colonoscopy; as well as non-invasive approaches, such as ultrasound, magnetic resonance imaging, and X-ray procedures that may or may not involve swallowing a chalky liquid containing barium or other materials that are radio-opaque. There’s even a wireless capsule that can shoot videos as it travels all the way through the GI tract. None of these techniques, however, provides a non-invasive, real-time view of the wave-like muscle contractions that move food through the gut—a crucial process called peristalsis.

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Global Health: Time to Pay Attention to Chronic Diseases

Graph of projected deaths by cause in low income countries

Caption: Projected deaths (in millions) by cause in low-income countries. Note increase in non-communicable diseases (orange).
Credit: Adapted from Beaglehole R, Bonita R. Lancet. 2008 Dec 6;372(9654):1988-96.

Greetings from China. I’m here in Shanghai with other biomedical research leaders for two major meetings. The first one, which is the topic of my blog today, is on global health. So, you might expect there to be a lot of talk about malaria, influenza, MERS-CoV, Ebola virus, sleeping sickness, dengue fever, tuberculosis, HIV/AIDS, and other infectious diseases. And those are most certainly topics of intense interest to NIH and our colleagues around the world. But this particular meeting is about a different kind of global health threat that’s becoming a rapidly growing problem: chronic diseases.

While infectious diseases remain a significant problem in the developing world, cancer, heart disease, obesity, diabetes, and other non-communicable diseases are now among the fastest growing causes of death and disability around the globe. In fact, nearly three-quarters of the 38 million people who died of chronic diseases in 2012 lived in low- or middle-income countries [1].

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Bionic Pancreas for Type 1 Diabetes

Ed Damiano and son David

Caption: Boston University researcher Ed Damiano with his son David, who has type 1 diabetes, in 2002.
Credit: Toby Milgrome

From taking selfies to playing Candy Crush, smart phones are being put to a lot of entertaining uses. But today I’d like to share an exciting new use of mobile health (mHealth) technology that may help to save lives and reduce disability among people with type 1 diabetes—an advance inspired by one researcher’s desire to help his son.

By teaming a smart phone with a continuous glucose monitor and two pumps designed to deliver precise doses of hormones, a team from Boston has created a bionic pancreas that appears to control blood glucose levels in people with type 1 diabetes more effectively than current methods. That is a significant achievement because if blood glucose levels are either too high or too low, there can be serious health consequences.

In a healthy body, the pancreas masterfully regulates blood glucose levels by orchestrating the secretion of insulin and another hormone, called glucagon, which raises blood glucose. These hormones work together like an automatic thermostat, raising and lowering blood glucose when appropriate. However, in type 1 diabetes, the pancreas produces little or no insulin, leading to increased levels of glucose that gradually damage blood vessels, kidneys, and nerves, raising the risk of blindness and amputations.

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