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Archive - Oct 13, 2015

Male Fruit Fly Pheromone (9-Tricosene) Marks Great Real Estate for Starting a Family; Finding May Extend to Mosquitoes and Be Useful in Malaria Control

In what they say was a lucky and unexpected finding, researchers at the Johns Hopkins University School of Medicine and the Monell Chemical Senses Center say they've discovered that male fruit flies lay down an odorant (pheromone), that not only attracts females to lay eggs nearby, but also guides males and females searching for food. The discovery, they say, offers clues about how flies, and probably other creatures, navigate complex environments and use odors to guide important behavioral decisions. "We didn't know flies could rapidly deposit pheromones in response to odors, but now we have evidence that that's the case with at least three such food odors," says Christopher Potter, Ph.D., Assistant Professor of Neuroscience at the Johns Hopkins University School of Medicine. A summary of the research findings appeared online on September 30, 2015 in an open-access article in the journal. The article is titled “Food Odors Trigger Drosophila Males to Deposit a Pheromone That Guides Aggregation and Female Oviposition Decisions.” Specifically, Dr. Potter says, experiments carried out by himself and his colleagues show that the pheromone known as 9-tricosene "flags a location as an ideal place for flies to mate, settle down, and have kids, so to speak. It's a way to help them associate mating with a food source that will give their offspring a good start in life." According to Potter, the pheromone's role was discovered serendipitously by graduate student Chun-Chieh Lin, who was testing a new experimental setup for use in other fly research. The setup involved placing flies in an enclosure shaped like a square that's been "pinched" on the sides, forming four pointed quadrants, with a glass top and bottom.

Moderate Red Wine Consumption May Help Type 2 Diabetics Manage Cholesterol & Cardiac Health; Red & White Wine Both Improve Sugar Control in Diabetics with Genetic Profiles Indicating They Are “Slow Alcohol Metabolizers”

A glass of red wine every night may help people with type 2 diabetes better manage their cholesterol and cardiac health, according to new findings from a two-year randomized controlled trial (RCT) led by researchers at Ben-Gurion University of the Negev (BGU) in Israel. Additionally, both red and white wine can improve sugar control, depending on genetic profiling indicating an individual’s rate of alcohol metabolism. In this first long-term alcohol study in diabetics, just published online opn October 13, 2015 in the Annals of Internal Medicine, the researchers aimed to assess the effects and safety of initiating moderate alcohol consumption in diabetics, and also sought to determine whether the type of wine matters. The article is titled “Effects of Initiating Moderate Alcohol Intake on Cardiometabolic Risk in Adults With Type 2 Diabetes: A 2-Year Randomized, Controlled Trial." People with diabetes are more susceptible to developing cardiovascular diseases than the general population and have lower levels of "good" cholesterol. Despite the enormous contribution of observational studies, clinical recommendations for moderate alcohol consumption remain controversial, particularly for people with diabetes, due to lack of long-term, randomized controlled trials, which are the "holy grail" of evidence-based medicine. "Red wine was found to be superior in improving overall metabolic profiles, mainly by modestly improving the lipid profile, by increasing good (HDL) cholesterol and apolipoprotein A1 (one of the major constituents of HDL cholesterol), while decreasing the ratio between total cholesterol and HDL cholesterol," the researchers explain.

“Beeting” Altitude Sickness by Drinking Nitrate-Rich Juice to Boost Nitric Oxide Levels in Blood to Improve Compromised Blood Vessel Function

Ever since human beings first began climbing the world's tallest mountains, they have struggled with a basic problem: altitude sickness, caused by lower air pressures which affect the ability of our bodies to take up oxygen. Or, as actor Jason Clarke says in his role as the climbing guide Rob Hall in the recently released movie, Everest, "Human beings simply aren't built to function at the cruising altitude of a 747." How well humans tolerate high altitudes is highly variable, but the best way to minimize the risk of developing acute mountain sickness (AMS) is acclimatization, or simply spending enough time up high to allow the body to make adjustments to lower oxygen levels. But what if you could help your body acclimatize more quickly and thoroughly with the help of a natural substance - like beet juice? A team of Norwegian and Swedish researchers decided to see how nitrate-rich beet juice might affect acclimatization on a 39-day expedition to Kathmandu and at 3700 meters (just over 12,000 feet) in the Rolwaling Valley of Nepal. One aspect of successful acclimatization is that the blood vessels are able to deliver enough oxygen throughout the body. But normal blood vessel function depends on the body's ability to naturally produce a compound called nitric oxide (NO). In healthy people at sea level, production of adequate amounts of NO is not a problem, but with the reduced oxygen availability at high altitude it is a challenge, simply because natural NO production requires oxygen. But the body has a "back-up system" for NO production at altitude, and it is here that beet juice can help. The secret ingredient in beet juice is high levels of nitrate (NO3-), which the body can then convert to NO.

Roles of Stem-Cell-Derived Exosomes in Stromal Remodeling, Tumor Progression, and Cancer Immunotherapy

A recent open-access report, by two scientists from the University of Sao Paulo in Brazil, reviews the potential of stem-cell-derived exosomes in the context of stromal remodeling and the ability of these exosomes to generate cancer-initiating cells in a tumor niche by inducing morphologic and functional differentiation of normal fibroblasts into tumor-initiating fibroblasts. The article also discusses the immunosuppressive potential of stem-cell-derived exosomes in cancer immunotherapy and prospective applications of such exosomes in cell-free therapies in future translational medicine. The first author Farah Fatima, Ph.D., and senior author Muhammad Nalwaz, Ph.D., noted, in their article abstract, that “stem cells are known to maintain stemness at least in part through secreted factors that promote stem-like phenotypes in resident cells. Accumulating evidence has clarified that stem cells release nano-vesicles, known as exosomes, which may serve as mediators of cell-to-cell communication and may potentially transmit stem cell phenotypes to recipient cells, facilitating stem cell maintenance, differentiation, self-renewal, and repair. It has become apparent that stem cell-derived exosomes mediate interactions among stromal elements, promote genetic instability in recipient cells, and induce malignant transformation.” The article was published in the Chinese Journal of Cancer, online on September 13, 2015, and in print in the December 2015 issue of the journal. The article is titled “Stem Cell-Derived Exosomes: Roles in Stromal Remodeling, Tumor Progression, and Cancer Immunotherapy.”

[Chinese Journal of Cancer artice]

Cancer Drug Tamoxifen Boosts Innate Immune System Via Influence on Ceramides in Neutrophils; May Prove Effective Weapon Against Methicillin-Resistant Staph aureus (MRSA) Bacteria

Researchers at University of California, San Diego (UCSD) School of Medicine and Skaggs School of Pharmacy and Pharmaceutical Sciences have found that the breast cancer drug tamoxifen gives white blood cells (specifically, neutrophils) a boost, better enabling them to respond to, ensnare, and kill bacteria in laboratory experiments. Tamoxifen treatment in mice also enhances clearance of the antibiotic-resistant bacterial pathogen MRSA and reduces mortality. (Note: Image shows neutrophil ingesting MRSA bacteria). The study was published online on October 13, 2015 in Nature Communications. The article is titled “Tamoxifen Augments the Innate Immune Function of Neutrophils through Modulation of Intracellular Ceramide.” "The threat of multidrug-resistant bacterial pathogens is growing, yet the pipeline of new antibiotics is drying up. We need to open the medicine cabinet and take a closer look at the potential infection-fighting properties of other drugs that we already know are safe for patients," said senior author Victor Nizet, M.D., Professor of Pediatrics and Pharmacy at the UCSD Skaggs School of Pharmacy and Pharmaceutical Sciences. Dr. Nizet is also affiliated with Rady Children’s Hospital in San Diego. "Through this approach, we discovered that tamoxifen has pharmacological properties that could aid the immune system in cases where a patient is immunocompromised or where traditional antibiotics have otherwise failed." Tamoxifen targets the estrogen receptor, making it particularly effective against breast cancers that display the molecule abundantly. But some evidence suggests that tamoxifen has other cellular effects that contribute to its effectiveness, too. For example, tamoxifen influences the way cells produce fatty molecules, known as sphingolipids, independent of the estrogen receptor.