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Archive - Feb 25, 2018


Better Diet May Ease Depression

People who eat vegetables, fruit, and whole grains may have lower rates of depression over time, according to a preliminary study released on February 25, 2018 and that will be presented at the American Academy of Neurology's 70th Annual Meeting in Los Angeles, April 21 to 27, 2018 ( The study found that people whose diets adhered more closely to the Dietary Approaches to Stop Hypertension (DASH) diet were less likely to develop depression than people who did not closely follow the diet. In addition to fruit and vegetables, the DASH diet recommends fat-free or low-fat dairy products and limits foods that are high in saturated fats and sugar. Studies have shown health benefits such as lowering high blood pressure and bad cholesterol (LDL), along with lowering body weight. "Depression is common in older adults and more frequent in people with memory problems, vascular risk factors such as high blood pressure or high cholesterol, or people who have had a stroke," said study author Laurel Cherian, MD, of the Rush University Medical Center in Chicago and a member of the American Academy of Neurology. "Making a lifestyle change such as changing your diet is often preferred over taking medications, so we wanted to see if diet could be an effective way to reduce the risk of depression." For the study, 964 participants with an average age of 81 were evaluated yearly for an average of six-and-a-half years. They were monitored for symptoms of depression such as being bothered by things that usually didn't affect them and feeling hopeless about the future.

Lizard Genome Sequencing Reveals Molecular Genetic Evidence for Rapid Evolution

Lizards have special superpowers. While birds can regrow feathers and mammals can regrow skin, lizards can regenerate entire structures such as their tails. Despite these differences, all have evolved from the same ancestor as lizards. Spreading through the Americas, one lizard group, the anoles, evolved like Darwin's finches, adapting to different islands and different habitats on the mainland. Today there are more than 400 species. Constructing a family tree for three lizard species collected in Panama at the Smithsonian Tropical Research Institute (STRI) and a fourth from the southeastern U.S., scientists at Arizona State University (ASU) compared lizard genomes--their entire DNA code--to those of other animals. The researchers discovered that changes in genes involved in the interbrain (the site of the pineal gland and other endocrine glands), for color vision, hormones, and the colorful dewlap that males bob to attract females, may contribute to the formation of boundaries between species. Genes regulating limb development also evolved especially quickly. "While some reptiles, such as tortoises, changed remarkably little over millions of years, anole lizards evolved quickly, generating a diversity of shapes and behaviors," said Dr. Kenro Kusumi, corresponding author and Professor at the ASU School of Life Sciences. "Now that sequencing entire genomes is cheaper and easier, we discovered molecular genetic evidence for rapid evolution that may account for striking differences between bodies of animals living in different environments." The study's findings were published in the February 1, 2018 issue of Genome Biology and Evolution. The open-access article is titled "Comparative Genomics Reveals Accelerated Evolution in Conserved Pathways during the Diversification of Anole Lizards." Dr.

Cutting-Edge Technology Enables Identification of Novel Nanoparticles (Exomeres) Released by Cancer Cells and Similar to Exosomes, But Smaller and with Different Functions

A new cellular messenger discovered by Weill Cornell Medicine scientists may help reveal how cancer cells co-opt the body’s intercellular delivery service to spread to new locations in the body. In a paper published online on February 19, 2018 in Nature Cell Biology, the scientists show that a cutting-edge technique called asymmetric flow field-flow fractionation (AF4) can efficiently sort nano-sized particles, called exosomes, that are secreted by cancer cells and contain DNA, RNA, fats, and proteins. This technology allowed the investigators to separate two distinct exosome subtypes and discover a new nanoparticle, which they named an “exomere.” The article is titled "Identification of Distinct Nanoparticles and Subsets of Extracellular Vesicles by Asymmetric Flow Field-Flow Fractionation." Also published online on February 19, 2018 was a description of the protocol used to identify the nanoparticles. “We found that exomeres are the most predominant particle secreted by cancer cells,” said senior author Dr. David Lyden, the Stavros S. Niarchos Professor in Pediatric Cardiology, and a scientist in the Sandra and Edward Meyer Cancer Center and the Gale and Ira Drukier Institute for Children’s Health at Weill Cornell Medicine. “They are smaller and structurally and functionally distinct from exosomes. Exomeres largely fuse with cells in the bone marrow and liver, where they can alter immune function and metabolism of drugs.

Mutation in Gene Controlling RNA Lariat Metabolism Implicated in Susceptibility to Lethal Brain Stem Infections by Common Viruses

For previously healthy children, brain infections are rare. But about one out of every 10,000 people who are exposed to common viruses like herpes simplex or influenza will develop a potentially deadly disease, encephalitis. Rockefeller's Dr. Jean-Laurent Casanova has identified mutations in a single gene that may explain what goes wrong in cases of encephalitis of the brain stem, the part of the brain that controls many basic functions including heart rate and breathing. Shen-Ying Zhang, Assistant Professor of Clinical Investigation in the Casanova lab, evaluated seven children from unrelated families who had been exposed to a common virus (herpes simplex virus 1, influenza virus, or norovirus) and developed a life-threatening or lethal infection of the brain stem. The scientists discovered mutations in a gene called DBR1, which is responsible for producing a protein (image) that helps process the loops formed in RNA during a step called mRNA splicing. Without it, immunity to viruses is selectively impaired in the brain stem. Dr. Casanova's experiments, published in the February 22, 2018 issue of Cell, point to an almost complete loss of DBR1 (debranching RNA lariats 1) as the culprit, enabling brain stem virus invasion in all seven patients. The findings also reveal an unexpected connection between an RNA processing mechanism and protective immunity in a specific region of the brain. The Cell article is titled “Inborn Errors of RNA Lariat Metabolism in Humans with Brainstem Viral Infection.” The study is a new example of the Casanova lab's ongoing work to identify mutations that underlie infectious diseases in otherwise healthy individuals. Previous work has found genetic factors that cause increased vulnerability to staph infections, the flu, and fungal infections, among others.