Snapshots of Life: Stronger Than It Looks

Structure of dental enamel

Credit: Olivier Duverger and Maria I. Morasso, National Institute of Arthritis and Musculoskeletal and Skin Diseases, NIH

If you went out and asked folks what they’re seeing in this picture, most would probably guess an elegantly woven basket, or a soft, downy feather. But what this scanning electron micrograph actually shows isn’t at all soft: it is the hardest substance in the mammalian body—tooth enamel!

This exquisitely detailed image—a winner of the Federation of American Societies for Experimental Biology’s 2015 BioArt competition—was generated by Olivier Duverger and Maria Morasso of NIH’s National Institute of Arthritis and Musculoskeletal and Skin Diseases. Before placing a sample of mouse dental enamel under the microscope, they treated it briefly with acid in order to reveal how the tissue’s mineralized rods are interwoven in a manner that gives teeth both strength and flexibility.

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Study Shows DNA Sequencing Brings Greater Precision to Childhood Cancer

Dr. Plon with a patient and her family

Caption: Baylor’s Sharon Plon consults with a family at the Texas Children’s Cancer Center in Houston.
Credit: Paul V. Kuntz/Texas Children’s Hospital

An impressive number of fundamental advances in our understanding of cancer have occurred over the past several decades. One of the most profound is the realization that cancer is a disease of the genome, driven by a wide array of changes in DNA—some in the germline and affecting all cells of the body, but most occurring in individual cells during life (so-called “somatic mutations”). As the technology for sequencing cancer genomes has advanced, we are learning that virtually all cancers carry a unique set of mutations. Most are DNA copying errors of no significance (we call those “passengers”), but a few of them occur in genes that regulate cell growth and contribute causatively to the cancer (we call those “drivers”). We are now learning that it may be far more important for treating cancer to figure out what driver mutations are present in a patient’s tumor than to identify in which organ it arose. And, as a new study shows, this approach even appears to have potential to help cancer’s littlest victims.

Using genomic technology to analyze both tumor and blood samples from a large number of children who’d been newly diagnosed with cancer, an NIH-funded research team uncovered genetic clues with the potential to refine diagnosis, identify inherited cancer susceptibility, or guide treatment for nearly 40 percent of the children [1]. The potential driver mutations spanned a broad spectrum of genes previously implicated not only in pediatric cancers, but also in adult cancers. While much more work remains to determine how genomic analyses can be used to devise precise, new strategies for treating kids with cancer, the study provides an excellent example of the kind of research that NIH hopes to accelerate under the nation’s new cancer “moonshot,”  a research initiative recently announced by the President and being led by the Vice President.

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Cool Videos: Spying on Cancer Cell Invasion

Spying on Cancer Cell Invation

If you’re a fan of the Mission: Impossible spy thrillers, you might think that secret agent Ethan Hunt has done it all. But here’s a potentially life-saving mission that his force has yet to undertake: spying on cancer cells. Never fear—some scientific sleuths already have!

So, have a look at this bio-action flick recently featured in the American Society for Cell Biology’s 2015 Celldance video series. Without giving too much of the plot away, let me just say that it involves cancer cells escaping from a breast tumor and spreading, or metastasizing, to other parts of the body. Along the way, those dastardly cancer cells take advantage of collagen fibers to make a tight-rope getaway and recruit key immune cells, called macrophages, to serve as double agents to aid and abet their diabolical spread.

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Gene Expression Test Aims to Reduce Antibiotic Overuse

Doctor with ER patient

Caption: Duke physician-scientist Ephraim Tsalik assesses a patient for a respiratory infection.
Credit: Shawn Rocco/Duke Health

Without doubt, antibiotic drugs have saved hundreds of millions of lives from bacterial infections that would have otherwise been fatal. But their inappropriate use has led to the rise of antibiotic-resistant superbugs, which now infect at least 2 million Americans every year and are responsible for thousands of deaths [1]. I’ve just come from the World Economic Forum in Davos, Switzerland, where concerns about antibiotic resistance and overuse was a topic of conversation. In fact, some of the world’s biggest pharmaceutical companies issued a joint declaration at the forum, calling on governments and industry to work together to combat this growing public health threat [2].

Many people who go to the doctor suffering from respiratory symptoms expect to be given a prescription for antibiotics. Not only do such antibiotics often fail to help, they serve to fuel the development of antibiotic-resistant superbugs [3]. That’s because antibiotics are only useful in treating respiratory illnesses caused by bacteria, and have no impact on those caused by viruses (which are frequent in the wintertime). So, I’m pleased to report that a research team, partially supported by NIH, recently made progress toward a simple blood test that analyzes patterns of gene expression to determine if a patient’s respiratory symptoms likely stem from a bacterial infection, viral infection, or no infection at all.

In contrast to standard tests that look for signs of a specific infectious agent—respiratory syncytial virus (RSV) or the influenza virus, for instance—the new strategy casts a wide net that takes into account changes in the patterns of gene expression in the bloodstream, which differ depending on whether a person is fighting off a bacterial or a viral infection. As reported in Science Translational Medicine [4], Geoffrey Ginsburg, Christopher Woods, and Ephraim Tsalik of Duke University’s Center for Applied Genomics and Precision Medicine, Durham, NC, and their colleagues collected blood samples from 273 people who came to the emergency room (ER) with signs of acute respiratory illness. Standard diagnostic tests showed that 70 patients arrived in the ER with bacterial infections and 115 were battling viruses. Another 88 patients had no signs of infection, with symptoms traced instead to other health conditions.

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Creative Minds: What Can Hibernation Tell Us About Human Health?

Black bear

Credit: Karen Laubenstein (Big Game Alaska)/U.S. Fish and Wildlife Service

When bears, bats, and other animals prepare to hibernate, they pack on fat at an impressive pace to almost double their weight. As they drift off into their winter slumber, their heart rates, breathing, and metabolism slow dramatically. Hibernating mammals can survive in this state of torpor for a period of weeks or even months without eating or drinking anything at all!

It’s a fascinating and still rather mysterious process—and one that William Israelsen of The University of Texas Southwestern Medical Center, Dallas, thinks may yield intriguing insights with implications for human health. A recipient of a 2015 NIH Director’s Early Independence Award, Israelsen plans to use a little-known mouse species to study hibernation in the laboratory at a level of detail that’s not possible in the wild. He especially wants to learn how hibernating animals shift their metabolic gears over the course of the year, and what those findings might reveal about human obesity, cancer, and other health conditions.

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