As spring finally emerges after a ferocious winter, our battered roads will soon be re-exposed. While potholes and cracks might make news, a larger concern should be the deterioration to pavement markings, from yellow to white lines, which are a major factor in preventing traffic accidents.A study from Concordia University, funded by Infrastructure Canada and published in Structure and Infrastructure Engineering, found that snowplows are the biggest culprit in erasing roadway markings.The research team also examined the impact of salt and sand on the visibility of pavement markings. The conclusion: a simple switch in paint can save cars — and lives.Using data from the Ontario and Quebec ministries of transportation and the municipalities of Montreal and Ottawa, Professor Tarek Zayed of Concordia’s Department of Building, Civil and Environmental Engineering measured the relationship between materials used in pavement markings, and their age and durability.He also compared highways with city roads, examined traffic levels and took note of the types of vehicles involved. Finally, Zayed and his research team examined marking types such as highway centre lines, pedestrian crosswalks and traffic intersections.They found snowploughs to be the worst on roads because they literally scrape paint off the streets. “Snow removal is the major contributing factor to wear and tear on pavement markings, because when snow is pushed off the road, part of the markings is taken off too,” says Zayed.What can improve the chances of pavement markings surviving the winter? Zayed suggests that an upgrade to more expensive and durable epoxy paint might be more cost effective in the long run. Other options include paint tape and thermoplastic, although these are quite expensive.He also suggests wider use of a technical device called a retroreflectometer to help assess the paint’s reflectivity and resulting effectiveness. “In the U.S., this standard has been in place for almost a decade,” he says, adding that minimum standards for reflectivity are used to signal when a road must be repainted.Zayed also says Canadian roads are in desperate need of more studies. For example, while epoxy is known to be a more durable paint, since it is not yet widely used in Ontario and Quebec, more research is needed to show exactly how it holds up to stressors like salt and snow removal.While several studies have been conducted in the central and southern United States to compare and evaluate the durability of pavement markings, Zayed points out that the findings don’t translate very well given the strikingly different weather conditions between warm versus seasonal climates.Story Source:The above story is based on materials provided by Concordia University. The original article was written by Suzanne Bowness. …Read more
Patients with rheumatic conditions are in need of symptom relief and some are turning to herbal cannabis as a treatment option. However, the effectiveness and safety of medical marijuana to treat symptoms of rheumatic conditions such as rheumatoid arthritis, lupus, or fibromyalgia is not supported by medical evidence. A new article published in Arthritis Care & Research, a journal of the American College of Rheumatology (ACR), explores the risks associated with using herbal cannabis for medicinal purposes and advises healthcare providers to discourage rheumatology patients from using this drug as therapy.The reason for the medical interest in herbal cannabis is that the human body has an extensive cannabinoid system comprising molecules and receptors that have effects on many functions including pain modulation. Medical cannabis is commonly used to self-treat severe pain associated with arthritis and musculoskeletal pain. In fact, previous research reports that 80% of marijuana users in a U.S. pain clinic are treating myofascial pain with the drug. In population studies in the U.K. and Australia, up to 33% of individuals report using marijuana to treat arthritis pain. As of June 2013, estimates from the office of Information Commissioner of Canada list “severe arthritis” as the reason the 65% of Canadians who are allowed to possess marijuana for medicinal purposes.”With the public outcry for herbal cannabis therapy, governments around the world are considering its legalization for medicinal use,” explains lead investigator Dr. Mary-Ann Fitzcharles, a researcher and rheumatologist at the McGill University Health Centre (MUHC) and the Research Institute of the MUHC in Quebec, Canada. …Read more
June 13, 2013 — Arthritis is a debilitating disorder with pain caused by inflammation and damage to joints.Yet the condition is poorly managed in most patients, since adequate treatments are lacking — and the therapies that do exist to ease arthritis pain often cause serious side effects, particularly when used long-term. Any hope for developing more-effective treatments for arthritis relies on understanding the processes driving this condition.A new study in the Journal of Neuroscience by researchers at McGill University adds to a growing body of evidence that the nervous system and nerve-growth factor (NGF) play a major role in arthritis. The findings also support the idea that reducing elevated levels of NGF — a protein that promotes the growth and survival of nerves, but also causes pain — may be an important strategy for developing treatment of arthritis pain.Using an approach established by arthritis researchers elsewhere, the McGill scientists examined inflammatory arthritis in the ankle joint of rats. In particular, they investigated changes in the nerves and tissues around the arthritic joint, by using specific markers to label the different types of nerve fibres and allow them to be visualized with a fluorescence microscope.Normally, sympathetic nerve fibres regulate blood flow in blood vessels. Following the onset of arthritis in the rats, however, these fibres began to sprout into the inflamed skin over the joint and wrap around the pain-sensing nerve fibres instead. More sympathetic fibres were detected in the arthritic joint tissues, as well.The results also showed a higher level in the inflamed skin of NGF — mirroring the findings of human studies that have shown considerable increases in NGF levels in arthritis patients.To investigate the role of these abnormal sympathetic fibres, the McGill researchers used an agent to block the fibres’ function. They found that this reduced pain-related behaviour in the animals.”Our findings reinforce the idea that there is a neuropathic component to arthritis, and that sympathetic nerve fibres play a role in increasing the pain,” said McGill doctoral student Geraldine Longo, who co-authored the paper with Prof. Afredo Ribeiro-da-Silva and postdoctoral fellow Maria Osikowicz.”We are currently using drugs to prevent the production of elevated levels of NGF in arthritic rats; we hope that our research will serve as a basis for the development of a new treatment for arthritis in the clinic,” said Prof. Ribeiro-da-Silva.This research was funded by grants from the Canadian Institutes of Health Research (CIHR), the Louise and Alan Edwards Foundation, and the MITACS-Accelerate Quebec program in partnership with Pfizer Canada.Read more
June 4, 2013 — Using a novel genetic ‘editing’ technique, Duke University biomedical engineers have been able to repair a defect responsible for one of the most common inherited disorders, Duchenne muscular dystrophy, in cell samples from Duchenne patients.Instead of the common gene therapy approach of adding new genetic material to “override” the faulty gene, the Duke scientists have developed a way to change the existing mutated gene responsible for the disorder into a normally functioning gene. The Duke researchers believe their approach could be safer and more stable than current methods of gene therapy.The researchers are now conducting further tests of this new approach in animal models of the disease.Duchenne muscular dystrophy is a genetic disease affecting one in 3,600 newborn males. The genetic mutation is found on the X chromosome, of which males have only one copy. (Females, with two X chromosomes, presumably have at least one good copy of the gene.)Patients with Duchenne muscular dystrophy cannot produce the protein known as dystrophin, which is essential in maintaining the structural integrity of muscle fibers. Over time, patients with the disorder suffer gradual muscle deterioration, which leads to paralysis and eventual death, usually by age 25.”Conventional genetic approaches to treating the disease involve adding normal genes to compensate for the mutated genes,” said Charles Gersbach, assistant professor of biomedical engineering at Duke’s Pratt School of Engineering and Department of Orthopaedic Surgery and member of Duke’s Institute for Genome Sciences and Policy. “However, this can cause other unforeseen problems, or the beneficial effect does not always last very long.”Our approach actually repairs the faulty gene, which is a lot simpler,” said David Ousterout, the Duke biomedical engineering graduate student in the Gersbach lab who led the work. “It finds the faulty gene, and fixes it so it can start producing a functional protein again.”The results of the Duke study were published online in Molecular Therapy, the journal of the American Society for Gene and Cell Therapy. The project was supported by the Hartwell Foundation, the March of Dimes Foundation and the National Institutes of Health.The Duke experiments, which were carried out in cell samples from Duchenne muscular dystrophy patients, were made possible by using a new technology for building synthetic proteins known as transcription activator-like effector nucleases (TALENs), which are artificial enzymes that can be engineered to bind to and modify almost any gene sequence.These TALENs bind to the defective gene, and can correct the mutation to create a normally functioning gene.”There is currently no effective treatment for this disease,” Gersbach said. “Patients usually are in a wheelchair by the age of ten and many die in their late teens or early twenties.”Duchenne muscular dystrophy has been extensively studied by scientists, and it is believed that more than 60 percent of patients with this type of mutation can be treated with this novel genetic approach.”Previous studies indicate that restoring the production of dystrophin proteins will be highly functional and alleviate disease symptoms when expressed in skeletal muscle tissue,” said Ousterout.Similar approaches could be helpful in treating other genetic diseases where a few gene mutations are responsible, such as sickle cell disease, hemophilia, or other muscular dystrophies, Gersbach said.Other members of the team were Duke’s Pablo Perez-Pinera, Pratiksha Thakore, Ami Kabadi, Matthew Brown, Xiaoxia Qin, and Olivier Fedrigo. Other participants were Vincent Mouly, Universite Pierre at Marie Curie, Paris, and Jacques Tremblay, Universite Laval, Quebec.Read more
May 21, 2013 — Children who are exposed to secondhand smoke in early childhood are more likely to grow up to physically aggressive and antisocial, regardless of whether they were exposed during pregnancy or their parents have a history of being antisocial, according to Linda Pagani and Caroline Fitzpatrick of the University of Montreal and its affiliated CHU Sainte-Justine hospital. No study to date has controlled for these factors.
“Secondhand smoke is in fact more dangerous that inhaled smoke, and 40% of children worldwide are exposed to it. Moreover, exposure to this smoke at early childhood is particularly dangerous, as the child’s brain is still developing,” Pagani said. “I looked at data that was collected about 2,055 kids from their birth until ten years of age, including parent reports about secondhand smoke exposure and from teachers and children themselves about classroom behaviour. Those having been exposed to secondhand smoke, even temporarily, were much more likely to report themselves as being more aggressive by time they finished fourth grade.”
The study was published in the Journal of Epidemiology and Community Health on May 21, 2013.
Given that it would be unethical to exposure children to secondhand smoke, Pagani relied on longitudinal data collected by Quebec health authorities from birth onward on an annual basis. Because parents went about raising their children while participating in the study, the data provided a natural experiment of variations in the child population of household smoke exposure throughout early childhood. Although no direct causal link can be determined, the statistical correlation suggests that secondhand smoke exposure does forecast deviant behavior in later childhood. The very detailed information collated for the Quebec Longitudinal Study of Child Development enabled her to do something no other researcher has done to date: distinguish the unique contribution of secondhand smoke exposure on children’s later deviant behavior. “Previous studies looking at groups of children have generally asked mothers whether they smoked or not, and how much at each follow-up, rather than asking whether someone smoked in the home where young children live and play,” Dr. Pagani said. “Furthermore, few studies have looked at antisocial behaviour in the parents and even fewer have investigated the subsequent influence of prolonged exposure to secondhand smoke over the long term. None have taken into account the fact that disadvantaged families are less likely to participate in a long study like this one, which of course skews the statistics.”
The statistics are backed by other biological studies into the effects of smoke on the brain. Secondhand smoke comprises 85% sidestream smoke emanated from a burning cigarette and 15% inhaled and then exhaled mainstream smoke. Sidestream smoke is considered more toxic than mainstream smoke because it contains a higher concentration of many dispersed respirable pollutants over a longer exposure period. “We know that the starvation of oxygen caused by smoke exposure in the developing central nervous system can cause low birth weight and slowed fetal brain growth,” Dr. Pagani said. “Environmental sources of tobacco smoke represent the most passive and preventable cause of disease and disability. This study suggests that the postnatal period is important for the prevention of impaired neurobehavioral development and makes the case for the promotion of an unpolluted domestic environment for children.”
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- Linda S Pagani, Caroline Fitzpatrick. Prospective associations between early long-term household tobacco smoke exposure and antisocial behaviour in later childhood. J Epidemiol Community Health, 2013 DOI: 10.1136/jech-2012-202191
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