Dengue Virus May Bolster Zika's Attack

Prior exposure to the dengue fever virus may increase the severity of Zika virus, a new study says. Early stage laboratory findings suggest this connection between the two viruses may help explain the current Zika outbreak in Latin American and Caribbean countries, according to the international team of researchers. Dengue and Zika belong to the Flaviviridae family of viruses and are transmitted by the Aedes aegypti mosquito. "Although this work is at a very early stage, it suggests previous exposure to dengue virus may enhance Zika infection," study senior author said. "This may be why the current outbreak has been so severe, and why it has been in areas where dengue is prevalent. We now need further studies to confirm these findings, and to progress towards a vaccine," study author said in a college news release. In recent decades, cases of dengue fever have increased sharply. The virus is believed to cause about 390 million infections a year, and about half of the world's population is at risk of dengue, according to the World Health Organization. Like Zika, it is most prevalent in tropical and subtropical climates. The researchers said that once someone has had dengue exposure, Zika may use the body's own immune defenses as a "Trojan horse" in order to enter cells undetected. Once inside the cell, Zika replicates rapidly. "We can't say yet whether this interaction is playing a role in the current outbreak, but if confirmed it's likely to have important implications for the control and global spread of Zika, and for the development of any vaccine for the virus," said the director of the Wellcome Trust, a medical research charity. The Trust funded the study, published June 23 in Nature Immunology. Although most people infected by Zika suffer only mild symptoms, in pregnancy it can cause severe birth defects, including brain damage. In another study, the same research team found that an antibody that's effective against dengue may also counter Zika. The researchers believe this finding that could aid efforts to develop a vaccine against Zika. These findings were published June 23 in the journal Nature. Zika and dengue "share many similarities in their genetic makeup, transmission pattern and in the immune response they trigger," he added. "These new studies suggest that prior infection with dengue doesn't offer any protection against Zika, and may in fact predispose people to a more severe infection," he said. For now, there are more questions than answers about Zika and this group of viruses, including dengue, he added. "We know that Zika has been present in Southeast Asia and Africa for many years and yet has not taken off there as it has in South America. This is what the international research effort needs to work out, and quickly," he said.

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                                                                                             Fiber: The Rx for Disease-Free Aging

Foods rich in fiber not only keep one "regular," they may help to live longer without disease, new research suggests. Among more than 1,600 Australian adults, the top fiber consumers were 80 percent more likely to remain fully functional and disease-free as they aged, the study found. Fiber-rich foods include fruits and whole grains. "Our observations need to be confirmed by other large studies, and we can't make recommendations at this stage such as pushing for a more plant-based diet," said study lead author said. Still, researcher and her colleagues weren't surprised by the findings, "given that there are numerous studies showing fiber's protective influence against a host of chronic diseases," she said. "Successful aging" was defined in the study as the continued absence of physical disability, depression, breathing problems, or chronic health issues such as cancer, high blood pressure, diabetes or heart disease. "People can achieve the recommended intake of fiber consumption -- around 30 grams per day -- by eating a wide range of foods such as whole-grain breads and cereals, fruits, vegetables and legumes," she noted. The researchers tracked the study participants, who were 49 years and older, for a decade starting in 1994. At the start, all were free of cancer and heart disease. Surveys assessed dietary routines, with a specific focus on fiber, carbohydrates and sugar intake. By those measures, the study team concluded that 15.5 percent of the participants had aged "successfully" over the 10-year time frame. By contrast, those whose fiber consumption was pegged at below-average levels were least likely to have aged well. Blood sugar levels and the impact of carbohydrates on blood sugar levels did not seem to play a role in how successfully people aged, the team noted. The researchers also found that only 25 percent of study participants were meeting daily fiber intake recommendations. Study author said this accurately reflects general population habits. "Based on our study we can't exactly pinpoint as to how fiber influences aging status," she added. But she said that her team speculates that fiber may affect blood sugar levels, minimizing inflammation throughout the body. "Inflammation is a key factor in aging and many chronic conditions. Also, fiber is known to increase satiety, which is likely to explain some of its health benefits," she explained. The study results were published recently in the Journals of Gerontology.

SOURCE: HealthDay News, June 2016

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                                                                            'Love Hormone' Gene May Be Key to Social Life

Lower activity of a specific gene may affect a person's social behavior, including the ability to form healthy relationships, researchers say. The OXT gene is involved in the production of oxytocin, a hormone linked with a large number of social behaviors in people. It's sometimes referred to as the "love hormone." The University of Georgia team assessed more than 120 people, conducting genetic tests and assessments of social skills, brain structure and brain function. The investigators found that those with lower activity of the OXT gene had a harder time recognizing emotional facial expressions and tended to be more anxious about their relationships with loved ones. These low-OXT people also had less activity in brain regions associated with social thinking. And they had less gray matter in an area of the brain important for face processing and social thinking, the study found. "All of our tests indicate that the OXT gene plays an important role in social behavior and brain function," lead author said. These are preliminary findings and further studies are needed, but this research could lead to new and better treatments for a number of social disorders, study author said. The study was published June 20 in the Proceedings of the National Academy of Sciences.

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