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Archive - Jul 27, 2017

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Study Highlights Health Consequences of Selectively Breeding German Shepherd Dogs

German Shepherd Dogs (GSDs) could be predisposed to health conditions such as arthritis because of the way they have been bred in recent decades, according to a new study published online on July 28, 2017 in the open-access journal Canine Genetics and Epidemiology. The article is titled “Demography and disorders of German Shepherd Dogs under primary veterinary care in the UK.” Data from nearly half a million dogs collected across 430 veterinary clinics in the UK, via the VetCompass™ Programme at the Royal Veterinary College, reveals that GSDs are most likely to die from complications arising from musculoskeletal disorders (13.6% of cases) or the inability to stand (14.9% of cases). A total of 263 specific disorder types were recorded in German Shepherds, the most common of which were inflammation of the ear canal (7.89% of dogs), osteoarthritis (5.54%), diarrhea (5.24%), overweight and obesity (5.18%), and aggression (4.76%). Dr. Dan O'Neill, lead author from the Royal Veterinary College, said: "German Shepherd Dogs have previously been reported to have the second highest number of health disorders exacerbated by breeding traits, with Great Danes occupying first place. It has been reported that German Shepherds are predisposed to conditions such as abnormal formation of the hip joint, cancer and degenerative spinal disorders, but the extent to which these conditions are prevalent in the population are unclear. However, by looking at primary care data from veterinary clinics, we are able to get a much better picture of the real priority conditions affecting this breed and this will help inform clinical practice in the future." The GSD is one of the most popular breeds worldwide with historical working roles that include herding, guarding, police, military, and guide-dog work.

Facial Muscle Combinations Underlying Three Types of Smiles: Reward, Affiliation, Dominance

The smile may be the most common and flexible expression, used to reveal some emotions, cover others, and manage social interactions that have kept communities secure and organized for millennia. But how do we tell one kind of smile from another? "When distinguishing among smiles, both scientists and laypeople have tended to focus on true and false smiles. The belief is that if you smile when you're not happy, the smile is false," says Dr. Paula Niedenthal, a psychology professor at the University of Wisconsin-Madison. "But people smile in many different circumstances and during many emotional states. So, asserting that only smiles that result from states of happiness are 'true' smiles limits our understanding of this important facial expression." Dr. Niedenthal and colleagues from Cardiff University and the University of Glasgow published in the journal Psychological Science (online on July 25, 2017 ) a set of experiments that seek to expand our understanding of the human smile, showing three distinct, reliably recognized expressions -- smiles of reward, affiliation, and dominance -- and describing the facial muscle combinations that make them. Each smile hinges on an anatomical feature known as the zygomaticus major, straps of facial muscle below the cheekbones that pull up the corners of the mouth. But this not the only muscle at work. Participants in the study looked at thousands of computer-generated expressions with random combinations of facial muscles activated -- with one exception. "We varied everything that could be varied in an expression, but our stimuli included some action from the smile muscle, the zygomaticus," says Dr. Magdalena Rychlowska, a postdoctoral researcher at Cardiff University. "We asked participants to tell us when they see a reward or affiliative or a dominance smile, and when the expression is not a smile."

Clue to Link Between Mutations in Autophagy Genes and Crohn’s Disease; Alternative Pathogen-Fighting System Uses Some of Autophagy’s Cellular Machinery

Genes that regulate a cellular recycling system called autophagy are commonly mutated in Crohn’s disease patients, though the link between biological housekeeping and inflammatory bowel disease remained a mystery. Now, researchers at the University of Texas (UT) Southwestern Medical Center have uncovered an intriguing clue. A research team led by Dr. Lora Hooper, Chair of Immunology at UT Southwestern and an Investigator of the Howard Hughes Medical Institute, has determined that a backup pathogen-fighting system uses autophagy’s cellular machinery to deliver protein weapons to the front lines – the cell surface – in the fight against bacterial attack. “This is the first example of this alternative pathway being used in immune defense in any kind of animal,” Dr. Hooper said of the mouse study, published online today (Juley 27, 2017) in Science. The article is titled “Paneth Cells Secrete Lysozyme Via Secretory Autophagy During Bacterial Infection of the Intestine.” The Centers for Disease Control and Prevention (CDC) estimates that approximately 3 million U.S. residents suffer from inflammatory bowel disease with that number about equally split between Crohn’s disease and ulcerative colitis. The two conditions are characterized by chronic inflammation of the gastrointestinal tract. Dr. Shai Bel, a postdoctoral researcher in Dr. Hooper’s laboratory and the lead author of the study, said the significance of the study’s findings rests on understanding the complex, dynamic ecosystem in the intestines. “Our guts are teeming with trillions of bacteria that do a great service by helping us digest food, but they can also cause illness if able to invade our tissues,” Dr. Bel said.

Brain Stem Cells Control Aging Rate in Mouse Model Via MicroRNA-Containing Exosomes

Scientists at Albert Einstein College of Medicine in New York City have found that stem cells in the brain’s hypothalamus govern how fast aging occurs in the body. The finding, made in mice, could lead to new strategies for warding off age-related diseases and extending lifespan. The paper was published online on July 26, 2017 in Nature. The article is titled "Hypothalamic Stem Cells Control Aging Speed Partly Through Exosomal miRNAs.” The hypothalamus was previously known to regulate important processes, including growth, development, reproduction, and metabolism. In a 2013 Nature paper, Einstein researchers made the surprising finding that the hypothalamus also regulates aging throughout the body. Now, the scientists have pinpointed the cells in the hypothalamus that control aging: a tiny population of adult neural stem cells, which were known to be responsible for forming new brain neurons. "Our research shows that the number of hypothalamic neural stem cells naturally declines over the life of the animal, and this decline accelerates aging," says senior author Dongsheng Cai, M.D., Ph.D., Professor of Molecular Pharmacology at Einstein. "But we also found that the effects of this loss are not irreversible. By replenishing these stem cells or the molecules they produce, it’s possible to slow and even reverse various aspects of aging throughout the body." In studying whether stem cells in the hypothalamus held the key to aging, the researchers first looked at the fate of those cells as healthy mice got older. The number of hypothalamic stem cells began to diminish when the animals reached about 10 months, which is several months before the usual signs of aging start appearing.