The Global Fool

our planet is our village

Asthma in Children: Effects of Exposure to Diesel Exhaust Particles
Oct12

Asthma in Children: Effects of Exposure to Diesel Exhaust Particles

By The Editors Diesel exhaust particles are one of the major components of air pollution. These particles are suspended in the air, and are microscopic — less than one-fifth the thickness of a human hair. As we breathe, they are drawn deep into the lungs. Because diesel-powered engines are everywhere, it is almost impossible to avoid them. People that live and work in urban and industrial areas are more likely to be exposed. Combined results from many epidemiological, clinical, and toxicological studies show that diesel exhaust particles are associated with respiratory disorders, as for example severe asthma. It is not surprising that children are especially susceptible to the effects of these particles. Results form a recenty study entitled “Diesel exhaust particle induction of IL-17A contributes to severe asthma” and published onine (September 23, 2013) in the Journal of Allergy and Clinical Immunology,  show that exposure to diesel exhaust particles from traffic pollution leads to increased asthma severity in children. The study was conducted by researchers at Cincinnati Children’s Hospital Medical Center. and provides insight into the mechanisms responsible for the development of severe asthma in children exposed to high levels of diesel exhaust particles — these mechanisms involve expansion of a type of white blood cells called T helper 17 cells and increased production by these cells of a protein, IL-17A. This protein is known to be associated with several chronic inflammatory diseases, including rheumatoid arthritis, psoriasis and multiple sclerosis. The researchers studied 235 children and teens with asthma by estimating their diesel exposure attributable to traffic based on where they lived. The researchers also studied mice exposed to diesel particles and dust mites, a common household allergen. In children with asthma, diesel exposure was associated with more frequent asthma symptoms and increased IL-17A blood levels. In mice, exposure to diesel and dust mites resulted in more severe asthma when compared to dust mite exposure alone. Neutralization of IL-17A in mice resulted in alleviation of airway inflammation induced by diesel exposure. Gurjit Khurana Hershey, MD, PhD, director of asthma research at Cincinnati Children’s and senior author of the study says that neutralization of IL-17A “may be a useful potential therapeutic strategy to counteract the asthma-promoting effects of traffic-related air pollution, especially in highly exposed, severe allergic...

Read More
Anthropogens: Inducers of Chronic Inflammation and Degenerative Diseases
Sep07

Anthropogens: Inducers of Chronic Inflammation and Degenerative Diseases

By Roberta Attanasio Injuries and infections are facts of life, and we need to deal with them. Thus, it’s not surprising we have developed efficient and magnificent sets of mechanisms that defend us from whatever is perceived as a danger, for example micro-organisms and irritant substances. Inflammation (or inflammatory response) is one of these sets of mechanisms, and not only — inflammation is our first line of defense, as well as the process that leads to repair of the damaged tissue. When the need arises, the inflammatory response stages a battle that results in the classical four signs of inflammation — swelling, redness, heat and pain — with the final goal of eliminating the threat and bring us back to health. The classical four signs of inflammation result from the coordinated action of different types of white blood cells, mostly macrophages, monocytes and neutrophils. These cells communicate with each other, and with the surrounding cells and tissues, through messenger molecules called cytokines and chemokines. Cytokines cause the dilation of small blood vessels and changes in their walls — because of these changes, monocytes and neutrophils, as well as proteins and fluid, move from the blood into the damaged tissue, leading to swelling, redness, heat and pain. Macrophages, monocytes and neutrophils help to get rid of any irritant substances and dangerous micro-organisms (pathogens). The role of inflammation, therefore, is to eliminate whatever represents a danger, limit tissue damage, and finally resolve it. Sometimes, however, inflammation becomes long-lasting (chronic). Chronic inflammation has the opposite effect — instead of resolving tissue damage, it leads to tissue degeneration. Chronic inflammation is low-grade, has systemic rather than local effects and is associated with a decreased metabolic rate. It may lead to the development of degenerative diseases, such as heart disease, obesity, rheumatoid arthitis and cancer, among others. In addition, chronic inflammation is frequently present during the aging process, aggravating degenerative diseases. Chronic, low-grade inflammation may develop following exposure to inducers called “anthropogens”. Anthropogens include factors related to lyfestyle or behavior encouraged by a man-made environment, as for example poor nutrition, inadequate sleep and lack of excercise. Additional anthropogens are represented by man-made chemicals — for examples environmental pollutants such as endocrine disruptors. The effects of a man-made environment, as is the case of social inequality, are considered anthropogens. Aging is sometime thought of an inducer of inflammation. However, not all anthropogens induce chronic inflammation or deleterious effects in general. Some may actually induce positive effects. Garry Egger, Professor of Health and Human Sciences at Southern Cross University (Lismore, NSW, Australia), offers new insight into the role that anthropogens play in the development of chronic...

Read More