The Global Fool

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Prenatal Exposure to Air Pollutants: Links to Attention Deficit Hyperactivity Disorder
Apr11

Prenatal Exposure to Air Pollutants: Links to Attention Deficit Hyperactivity Disorder

By Roberta Attanasio PHAs — short for polycyclic aromatic hydrocarbons — are bad actors: they’re toxic, ubiquitous pollutants that readily cross the placenta, causing damage to the fetal brain. Now, results from a new study show that PHA-induced fetal brain damage may lead to severe behavioral problems during early childhood, including aggression and attention deficit hyperactivity disorder (ADHD). The deleterious effects of air pollution — greater risk of stroke, heart attacks and cognitive deterioration — are widely recognized. However, the new study assessed prenatal exposure and identified specific physical damage in the brain. The researchers used magnetic resonance imaging to measure the brains of 40 children from a cohort consisting of more than 600 mother-baby pairs. The mothers were either Latina (Dominican) or African American nonsmoking women from minority communities in New York City, aged 18 to 35 years. During the third trimester of pregnancy, the women carried personal backpack monitors that measured exposure to eight common PAHs over 48 hours. Such exposure occurred by breathing contaminated air. PHAs — common components of air pollution — are often found together in groups of two or more and persist in the environment for long periods of time. They’re generated by motor vehicles, waste incineration, wildfires and agricultural burning, and oil and coal burning for heat and electricity. Cooking (especially charred foods), tobacco smoke, and space heaters are indoor sources of PHAs. Low-income, urban, and minority communities are disproportionately exposed to these air pollutants. The researchers had previously demonstrated that exposure of the pregnant women from the same cohort to airborne PAHs was associated with multiple neuro-developmental disturbances. Results form the new study indicate that such disturbances have a biological root in the altered architecture of the brain. Specifically, PHA exposure was linked to reductions of the white matter surface in later childhood. These reductions were confined almost exclusively to the left hemisphere of the brain, and involved almost its entire surface. The researchers don’t know why the left side seemed to be affected more, but they suspect the compounds interfere with an early biochemical process that helps the fetal brain divide into slightly asymmetrical hemispheres. Results from the study also show that postnatal PAH exposure correlates with white matter surface measures in other regions of the brain, the dorsal prefrontal regions. Thus, the children involved in the study were exposed to “a double hit”, first as developing fetuses, and then at an early age. Indeed, Bradley Peterson, lead author of the study, told the Los Angeles Times: “It’s a double hit. They have the abnormality from prenatal life throughout the left hemisphere and then on top of that they have...

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The Global Travels of Chikungunya Virus: Is it Coming to You?
Mar30

The Global Travels of Chikungunya Virus: Is it Coming to You?

By Roberta Attanasio Chikungunya virus is spreading fast — worldwide. First described during an outbreak in southern Tanzania in 1952, it caused sporadic illness in Africa and large urban outbreaks in Thailand and India in the 1960s and 1970s. As of now, it has been identified in over 60 countries in Asia, Africa, Europe and Americas. The virus, which causes fever and severe joint pain, is transmitted to humans by the bites of infected female mosquitoes, most commonly by Aedes aegypti and Aedes albopictus — two species that can also transmit other mosquito-borne viruses, including dengue. There is no vaccine and no specific treatment for the infection. Gemma Handy aptly describes the onset of the disease in an Antiguan patient: “The acute ache started in her ankles before quickly spreading through her body, crippling her muscles, pounding her joints and leaving her hands and feet severely swollen.” The patient said: “”I was fine when I went to bed, but when I woke up in the morning and tried to get up my ankles hurt so much I couldn’t stand. It was very scary. After that I started getting different pains all over my body. Soon my hands were so swollen I couldn’t hold anything.” Indeed, “chikungunya” derives from a word in the Kimakonde language, which is spoken by the Makonde, an ethnic group in southeast Tanzania and northern Mozambique — it means “to become contorted”, and describes the stooped appearance of sufferers with joint pain. Most patients recover fully, but in some cases joint pain may persist for several months, or years — and even become a cause of chronic pain and disability. In 2007, disease transmission was reported for the first time in a localized outbreak in north-eastern Italy. Outbreaks have since been recorded in France and Croatia. According to the Centers for Disease Control and Prevention (CDC), the first local transmission of Chikungunya virus in the Americas was identified in Caribbean countries and territories in late 2013 — local transmission means that mosquitoes in the area have been infected with the virus and are spreading it to people. Beginning in 2014, Chikungunya virus disease cases were reported among U.S. travelers returning from affected areas in the Americas and local transmission was identified in Florida, Puerto Rico, and the U.S. Virgin Islands. The current numbers of people infected with the virus within the Americas are staggering: the Pan-American Health Organization reports that, as of the end of February 2015, the initial handful of cases had exploded to 1,247,400 suspected and confirmed cases, affecting almost every country in the hemisphere. After the first locally acquired case of Chikungunya was reported...

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Food Additives, Microbiota, and Inflammation
Mar27

Food Additives, Microbiota, and Inflammation

By Roberta Attanasio “For centuries, additives have served useful functions in a variety of foods. Our ancestors used salt to preserve meats and fish, added herbs and spices to improve the flavor of foods, preserved fruit with sugar, and pickled cucumbers in a vinegar solution. Today, consumers demand and enjoy a food supply that is flavorful, nutritious, safe, convenient, colorful and affordable. Food additives and advances in technology help make that possible.” But, are food additives safe? Results from a recent study show that some food additives known as emulsifiers can alter the composition and location of the gut microbiota — the diverse population of 100 trillion bacteria that inhabit the intestinal tract — thus inducing intestinal inflammation. This inflammation, in turn, promotes the development of inflammatory bowel disease (Crohn’s disease and ulcerative colitis) and metabolic syndrome — disorders that are often severe and debilitating and afflict millions of people. The ancient Greeks used the emulsifying power of beeswax in cosmetic products. Egg yolk was probably the first emulsifier ever used in food production back in the early 19th century. Emulsifiers are now added to bread, chocolate, ice cream, margarine, processed meat, and more. But why? Add oil to water and the two liquids will never mix. At least not until an emulsifier is added. Emulsifiers are molecules with one water-loving (hydrophilic) and one oil-loving (hydrophobic) end. They make it possible for water and oil to become finely dispersed in each other, creating a stable, homogenous, smooth emulsion. The study results show that, in a mouse model, two common emulsifiers — caboxymethylcellulose (CMC) and polysorbate-80 (P80) — not only change the composition of the gut microbiota, they also make the gut more porous. The altered microbiota has enhanced capacity to digest and infiltrate the dense mucus layer that lines the intestine — bacteria reach immune cells, thus inducing activation of inflammatory pathways and the development of severe inflammation. Such changes in bacteria trigger chronic colitis in mice genetically prone to this disorder, due to abnormal immune systems. In contrast, in mice with normal immune systems, emulsifiers induce low-grade or mild intestinal inflammation and metabolic syndrome, characterized by increased levels of food consumption, obesity, hyperglycemia and insulin resistance. Fergus Shanahan (University College Cork), who was not involved in the study, told Ed Yong: “This work cannot be ignored.” He doubted that most people would be significantly affected by occasionally eating foods with emulsifiers — but risk might change for those who have a genetic predisposition to inflammatory bowel disease, or who eat lots of processed foods. Andrew Gewirtz, senior author of the study, said in a press release: “We do...

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Small Predator Diversity Plays a Significant Role in the Spread of Infectious Diseases
Mar23

Small Predator Diversity Plays a Significant Role in the Spread of Infectious Diseases

By Roberta Attanasio Biodiversity is a term coined to describe the diversity of all living things, from human beings to microorganisms. A New York Times editorial published almost two decades ago aptly describes the importance of the biodiversity concept: “Biodiversity is a hugely important concept that stresses the coherence and interdependence of all forms of life on earth and a new willingness to appraise the meaning of that interdependence, not just for humans but for every one of life’s component parts.” The editorial goes on to illustrate the alarming effects of biodiversity loss: “Biodiversity is a way of talking about what scientists have long understood and a way of reminding the rest of us of a cardinal fact: that we are standing in the midst of the earth’s sixth great extinction of diverse species, that this extinction is driven by us and that we are not now and will never be immune to its effects.” One of these effects is the worldwide spike in infectious diseases, as suggested by a study recently published in the journal Proceedings of the National Academy of Sciences. The study (Predator diversity, intraguild predation, and indirect effects drive parasite transmission) explores how the diversity of small predators shapes the transmission of parasites in wetlands. Lead author Jason Rohr said in a press release by Penn State: “In the last century, there has been an unprecedented global increase in infectious diseases and a concomitant decline in and homogenization of biodiversity. The controversial ‘dilution effect hypothesis’ suggests that the two phenomena might be linked, or that biodiversity often decreases disease risk.” The study, which included a series of laboratory experiments, field surveys and mathematical modeling, shows that — in presence of various species of dragonfly larvae — there is a reduction of frog infections caused by trematodes, which are parasitic flatworms also known as flukes. The dragonfly larvae are small predators that eat trematodes. Val Beasley, senior author of the study, said in the press release that various species of trematodes penetrate tadpoles. The trematodes sometimes kill the tadpoles. In other instances, the trematodes weaken them by causing tissue damage, kidney failure, or severe limb deformities while the tadpoles develop into frogs. He added that other vertebrate species commonly catch trematode infections from bodies of water. These vertebrate species include wildlife, domestic animals and humans — mostly children — who are commonly affected by schistosomiasis in tropical parts of the world. Schistosomiasis is a parasitic disease carried by freshwater snails infected with one of the five varieties of the parasite Schistosoma, a type of trematode. Although the worms that cause schistosomiasis are not found in the...

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Climate Change: A Key Driver of the Syrian Conflict?
Mar11

Climate Change: A Key Driver of the Syrian Conflict?

By Roberta Attanasio Climate change is happening here and now, with significant damage to natural systems and society. The shrinking of the Arctic sea ice, the melting of the Greenland and Antarctica ice sheets, the acidification of the oceans, the sea level rise, the shifting patterns of precipitation, and the amplified threat of wildfires, are some of its well-recognized effects. There are also significant concerns related to the consequences that climate change could have on freshwater availability and agricultural productivity worldwide — resulting in increasing poverty and further weakening of fragile governments. Indeed, climate change has been identified as a “threat multiplier” — it can exacerbate political instability in the world’s most dangerous regions. “Droughts, floods, food and water shortages and extreme weather can uproot communities, cause humanitarian crises and increase the chances of armed conflict.”   Now, results from a study carried out by researchers at Columbia University and the University of California Santa Barbara (published in the scientific journal Proceedings of the National Academy of Sciences on March 2, 2015) show that the Syrian conflict has been caused, at least in part, by a record drought. The drought occurred approximately from 2007 to 2010, and was worsened by global warming. The researchers wrote: “For Syria, a country marked by poor governance and unsustainable agricultural and environmental policies, the drought had a catalytic effect, contributing to political unrest.” The Syrian uprising began in the Spring of 2011 and then escalated into an ongoing civil war, leading to one of the largest refugee exoduses in recent history — neighboring countries such as Lebanon, Jordan and Turkey are struggling to accommodate the displaced populations. According to the BBC, “Almost 200,000 Syrians have lost their lives in the escalating conflict between forces loyal to President Bashar al-Assad and those opposed to his rule. Syria’s bloody internal conflict has destroyed entire neighborhoods and forced more than nine million people from their homes.” In addition, the war has now acquired sectarian overtones. In their published study, the researchers point out that the 2007−2010 record drought caused widespread crop failure and a mass migration of farming families to urban centers. In 8 years, the Syrian urban population rose by 50%. But what caused, precisely, the widespread crop failure? According to the researchers, unsustainable farming practices led to a massive depletion of groundwater while the region was experiencing a long-term decline in rainfall. At the same time, summer temperatures rose, drying out much of the remaining moisture in the soil. Colin Kelley, leading author of the study, wrote in The Conversation: “We found that there is very little evidence to suggest that long-term trends toward higher...

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