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Archive - Jun 8, 2015

Counting Crows—Fabled Birds Use “Number Neurons” Tuned to the Specific Number of Visual Objects in Order to Count

An old story says that crows have the ability to count. Three hunters go into a blind situated near a field where watchful crows roam. They wait, but the crows refuse to move into shooting range. One hunter leaves the blind, but the crows won’t appear. The second hunter leaves the blind, but the crows still won’t budge. Only when the third hunter leaves, the crows realize that the coast is clear and resume their normal feeding activity. Dr. Helen Ditz and Professor Andreas Nieder of the University of Tübingen in Germany have found the neuronal basis of this numerical ability in crows. They trained crows to discriminate groups of dots. During performance, the team recorded the responses of individual neurons in an integrative area of the crow endbrain. This area also receives inputs from the visual system. The neurons ignore the dots' size, shape, and arrangement and only extract their number. Each cell's response peaks at its respective preferred number. The study, which was published online on June 8, 2015 in PNAS, provides valuable insights into the biological roots of counting capabilities. “When a crow looks at three dots, grains, or hunters, single neurons recognize the groups’ ‘threeness’“ says Dr. Ditz. “This discovery shows that the ability to deal with abstract numerical concepts can be traced back to individual nerve cells in corvids.” The PNAS article is titled “Neurons Selective to the Number of Visual Items in the Corvid Songbird Endbrain.” What makes this finding even more interesting is that a long evolutionary history separates us from birds. As a consequence, the brains of crows and humans are designed very differently. “Surprisingly, we find the very same representation for numbers as we have previously discovered in the primate cortex,” Professor Nieder says.

ASCO NEWS: Exosome Diagnostics Announces Revolutionary Liquid Biopsy Diagnostics for Combined Capture of Exosomal RNA & Cell-Free DNA to Detect Actionable Mutations for Multiple Cancers

Exosome Diagnostics, Inc., a developer of revolutionary, biofluid-based molecular diagnostics, on June 2, 2015 announced data demonstrating the ability of its plasma-based liquid biopsy panel for solid tumors, which co-isolates and analyzes exosomal RNA (exoRNA) and cell-free DNA (cfDNA), to provide robust, highly sensitive detection of actionable mutations in plasma across multiple cancers. The company announced additional data showing that its proprietary exoRNA plus cfDNA platform also enabled plasma-based longitudinal monitoring of BRAF mutant melanoma, and demonstrated the ability to detect early disease progression multiple months prior to clinical evidence of the changes. Exosome Diagnostics is developing innovative plasma- and urine-based liquid biopsies that analyze exoRNA for biomarkers and can simultaneously isolate and analyze cfDNA to enhance detection of rare mutations. The solid tumor liquid biopsy panel and BRAF data were presented in poster sessions at the 2015 American Society of Clinical Oncology (ASCO) Annual Meeting, that took place May 29 – June 2 in Chicago, Illinois. Based on these and earlier data, Exosome Diagnostics plans to commercialize its solid tumor panel liquid biopsy as a laboratory-developed test in the company’s certified CLIA laboratory in 2015. The test, which is performed on simple blood samples, and covers 26 genes and 1000 associated mutations in the most significant cancer pathways, including EGFR/MAPK and PI3K, will initially be made available to pharmaceutical companies as a clinical development tool. “These findings further validate our unique, exoRNA-based liquid biopsy approach, and the potential clinical significance of analyzing exoRNA to reveal molecular insights about cancer,” said Vince O’Neill, M.D., Chief Medical Officer of Exosome Diagnostics.

Eliminating Staph aureus from the Nasal Microbiome

Staphylococcus aureus, a bacterium better known as Staph, is a common inhabitant of the human nose, as well as of the skin, and people who carry it are at increased risk for dangerous Staph infections. However, it may be possible to exclude these unwelcome guests from the nose using other more benign bacteria, according to a new study led by scientists representing the Translational Genomics Research Institute (TGen) in Arizona, the Statens Serum Institut in Denmark, and Milken Institute School of Public Health (SPH) at the George Washington University. The study, published online on June 5, 2015 in an open-access article in the AAAS journal Science Advances, suggests that a person's environment is more important than their genes in determining the bacteria that inhabit their noses. The study also suggests that some common nasal bacteria may prevent Staph colonization. "This study is important because it suggests that the bacteria in the nose are not defined by our genes and that we may be able to introduce good bacteria to knock out bad bugs like Staph," said Lance B. Price, Ph.D., the Director of TGen's Center for Microbiomics and Human Health and a Professor of Environmental and Occupational Health at the Milken Institute SPH. "Using probiotics to promote gut health has become common in our culture. Now, we're looking to use these same strategies to prevent the spread of superbugs." The new Science Advances article is titled “Staphylococcus aureus and the Ecology of the Nasal Microbiome.” The multi-center research team looked at data taken from 46 identical twins and 43 fraternal twins in the Danish Twin Registry, one of the oldest registries of twins in the world. "We showed that there is no genetically inherent cause for specific bacteria in the nasal microbiome," said senior author Dr. Paal Skytt Andersen. Dr.