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Archive - Oct 14, 2019

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Koala Epidemic Provides Lesson on How DNA Protects Itself from Viruses

In animals, infections are fought by the immune system. Studies on an unusual virus infecting wild koalas, by a team of researchers from the University of Massachusetts Medical School and the University of Queensland, reveal a new form of "genome immunity." The study was published online on October 10, 2019 in Cell. The open-access article is titled “The piRNA Response to Retroviral Invasion of the Koala Genome.” Retroviruses, including pathogens like HIV, incorporate into the chromosomes of host cells as part of their infectious lifecycle. Retroviruses don't usually infect the germ cells that produce sperm and eggs and, therefore, are not usually passed from generation to generation, but this has happened several times during evolution. Of the entire 3 billion nucleotides of the human genome, only 1.5% of the sequence forms the 20,000 genes that code for proteins - and 8% of the human genome comes from fragments of viruses. These pathogen invasions of the genome have sometimes been beneficial. For example, a gene "co-opted" from a virus is required for formation of the placenta in all mammals, including humans. Retroviral infection of germ cells has been a rare, but important, driving force in human evolution. But how the germ cells in mammals respond to pathogen invasion has not been previously described and might be quite different than what happens in other cells of the body. KoRV-A is a retrovirus sweeping through the wild koala population of Australia and it is associated with susceptibility to infection and cancer. KoRV-A spreads between individual animals, like most viruses. Surprisingly, KoRV-A also infects the germline cells, and most wild koalas are born with this pathogen as part of the genetic material of every cell in the body. The team used this system to see how germ cells respond to a retrovirus.

Sleep Apnea May Be Risk Factor for Diabetic Macular Edema

New research from Taiwan shows that severe sleep apnea is a risk factor for developing diabetic macular edema, a complication of diabetes that can cause vision loss or blindness. Diabetic macular edema was also more difficult to treat in patients with severe sleep apnea. While earlier research showed a weak connection between the two conditions, evidence is mounting that sleep apnea exacerbates underlying eye disease. The researchers presented their study on October 14 at AAO 2019, the 123rd Annual Meeting of the American Academy of Ophthalmology (AAO) (https://www.aao.org/annual-meeting), held October 12-15 in San Francisco. When people with diabetes have poor control over their blood sugar levels, the tiny blood vessels at the back of the eye can become damaged. This condition is called diabetic retinopathy and it's a leading cause of blindness in the United States. Sometimes, tiny bulges protrude from the blood vessels, leaking fluid and blood into the retina. This fluid can cause swelling or edema in an area of the retina that allows us to see clearly. Sleep apnea is a sleep disorder in which breathing repeatedly stops and starts, disrupting sleep and causing blood oxygen levels to drop. This drop in oxygen appears to unleash a host of changes in the body that may play a role in injuring blood vessels. People with sleep apnea are at risk of developing hypertension, heart attacks, stroke, and type 2 diabetes.nBut what about the eyes? Researchers believe that sleep apnea may contribute to the development and worsening of diabetic retinopathy by increasing insulin resistance, elevating inflammation and raising blood pressure, all of which can damage the blood vessels at the back of the eye.

Researchers Rediscover Fast-Acting German Insecticide Lost in Aftermath of WWII; Relative of DDT Permits Faster Killing of Insects with Lower Doses and May Have Less Environmental Impact

A new study, published online on October 11, 2019, in the Journal of the American Chemical Society, explores the chemistry as well as the complicated and alarming history of DFDT (image), a fast-acting insecticide. The open-access article is titled “Manipulating Solid Forms of Contact Insecticides for Infectious Disease Prevention.” "We set out to study the growth of crystals in a little-known insecticide and uncovered its surprising history, including the impact of World War II on the choice of DDT--and not DFDT--as a primary insecticide in the 20th century," said Bart Kahr, PhD, Professor of Chemistry at New York University (NYU) and one of the study's senior authors. Dr. Kahr and fellow NYU Chemistry Professor Michael Ward, PhD, study the growth of crystals, which two years ago led them to discover a new crystal form of the notorious insecticide DDT. DDT is known for its detrimental effect on the environment and wildlife. But the new form developed by Dr. Kahr and Dr. Ward was found to be more effective against insects--and in smaller amounts, potentially minimizing its environmental impact. In continuing to explore the crystal structure of insecticides, the research team began studying fluorinated forms of DDT, swapping out chlorine atoms for fluorine. They prepared two solid forms of the compound--a monofluoro and a difluoro analog--and tested them on fruit flies and mosquitoes, including mosquito species that carry malaria, yellow fever, Dengue, and Zika. The solid forms of fluorinated DDT killed insects more quickly than did DDT; the difluoro analog, known as DFDT, killed mosquitoes two to four times faster. "Speed thwarts the development of resistance," said Dr. Ward, a senior author on the study. "Insecticide crystals kill mosquitoes when they are absorbed through the pads of their feet.

BioTechne Receives Favorable Local Coverage Decision for Its ExoDx Prostate (Intel Score) (EPI) Liquid Biopsy Test; Over 60 Million Medicare Beneficiaries Will Be Covered for the Non-Invasive Test Used for Early Detection

On October 10, 2019, Bio-Techne Corporation (NASDAQ:TECH) today announced that the Medicare Administrative Contractor (MAC) National Government Services, Inc. issued a final Local Coverage Decision (LCD) covering the ExoDx Prostate(IntelliScore) – EPI – test for men who are being considered for an initial prostate biopsy. The decision is effective for tests administered on or after December 1, 2019. Following the LCD finalization, more than 60 million Medicare beneficiaries will now be covered for the EPI test effective December 1, 2019. The EPI test is a non-invasive, non-DRE requiring, urine-based, liquid biopsy test intended for men 50 years of age and older who have an elevated Prostate Specific Antigen (PSA) level between 2 – 10 ng/mL and who are being considered for a prostate biopsy. This liquid biopsy test recently received FDA Breakthrough Designation and is included in the NCCN guidelines for early detection in men for both initial and repeat biopsy. It is performed by Exosome Diagnostics, a Bio-Techne brand, in the CLIA-, ISO-, and NY-certified laboratory located in Waltham, Massachusetts, which has processed over 30,000 patient tests to date. The EPI test is a risk assessment tool that assists physicians and their patients with determining if a prostate biopsy is needed when presented with an ambiguous PSA test result. "It's been an extraordinary year for our ExosomeDx platform," commented Chuck Kummeth, Chief Executive Officer of Bio-Techne. "To achieve the NCCN guideline status after two remarkable patient studies was a great success for the ExosomeDx team and the company but attaining FDA breakthrough status was a testament to the strong promise this technology platform can bring to diagnosing cancer.