Function found for mysterious heart disease gene

A new study from researchers at the University of Ottawa Heart Institute (UOHI), published today in Cell Reports, sheds light on a mysterious gene that likely influences cardiovascular health. After five years, UOHI researchers now know how one genetic variant works and suspect that it contributes to the development of heart disease through processes that promote chronic inflammation and cell division.Researchers at the Ruddy Canadian Cardiovascular Genetics Centre had initially identified a variant in a gene called SPG7 as a potential contributor to coronary artery disease several years ago, but its role in multiple health processes made it difficult to tease out how it affects heart disease.The gene holds instructions for producing a protein called SPG7. This protein resides in mitochondria — the small power plants of cells that produce the energy cells need to function. SPG7’s role is to help break down and recycle other damaged proteins within the mitochondria.Normally, SPG7 requires a partner protein to activate itself and start this breakdown process. But, in people who carry the genetic variant in question, SPG7 can activate itself in certain circumstances, leading to increased production of free radicals and more rapid cell division. These factors contribute to inflammation and atherosclerosis.”We think this variant would definitely heighten the state of inflammation, and we know that inflammation affects diabetes and heart disease,” said Dr. Stewart, Principal Investigator in the Ruddy Canadian Cardiovascular Genetics Centre and senior author of the study. “Interestingly, the variant also makes people more resistant to the toxic side effects of some chemotherapy drugs.”From an evolutionary perspective, this resistance could help such a genetic variant gain a stable place in the human genome. Between 13 and 15 per cent of people of European descent possess this variant.”The idea of mitochondria contributing to inflammation isn’t new,” concluded Dr. Stewart. …

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Cognitive function and oral perception in independently-living octogenarians

Today, at the 43rd Annual Meeting & Exhibition of the American Association for Dental Research (AADR), held in conjunction with the 38th Annual Meeting of the Canadian Association for Dental Research, Kazunori Ikebe, from Osaka University, Japan, will present a research study titled “Cognitive Function and Oral Perception in Independently-living Octogenarians.”In this study, researchers hypothesized that the decline of cognitive impairment is involved in oral perceptions since its preclinical stage. The aim of this study was to examine association of cognitive function with tactile and taste perceptions in independently-living 80-year-old elderly.The participants were community-dwelling and independently-living elderly (n=956, 80 years old) excluding those with dementia. Cognitive function was measured using the Japanese version of the Montreal Cognitive Assessment (MoCA-J) that was the assessment tool of mild cognitive impairment. Oral tactile perception was tested by oral stereognostic ability (OSA) with the test pieces comprised six shaped forms. Subjects were told they should use their tongue and palate to identify the shape. The correct identification of the shape was scored. Taste perception was evaluated by the whole mouth gustatory test with 1-ml of water solution included the four basic tastes (sweet, sour, salty and bitter). The concentration answered the taste correctly was taken as the recognition threshold.Multiple linear regression analysis was used to examine relationships between tactile and taste perceptions and cognitive function after controlling for gender and number of teeth. P-values<0.05 were considered to be statistically significant.</p>The OSA score was positively associated with number of teeth. On the other hand, taste thresholds of sour, salty and bitter were significantly lower in female than males. …

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Ruling with an iron fist could make your child pack on pounds

If you’re rigid with rules and skimpy on affection and dialogue with your kids, they have a greater chance of being obese, according to research presented at the American Heart Association’s Epidemiology & Prevention/Nutrition, Physical Activity & Metabolism Scientific Sessions 2014.Researchers followed a nationally representative group of 37,577 Canadian children aged 0 to 11. They compared kids whose parents are generally affectionate, have reasonable discussions about behavior with their child and set healthy boundaries (authoritative) with those whose parents were strict about limits without much dialogue or affection (authoritarian).The latter group had a 30 percent higher chance of being obese among kids 2 to 5 years old and a 37 percent higher chance among kids 6 to 11 years.”Parents should at least be aware of their parenting style,” said Lisa Kakinami, Ph.D., a post-doctoral epidemiologist at McGill University in Montreal. “If you’re treating your child with a balance of affection and limits — these are the kids who are least likely to be obese.”Researchers compared parents’ answers to a cross-sectional survey. They then categorized parenting styles and analyzed them with respect to children’s body mass index (BMI) percentile.Researchers also found that poverty was associated with childhood obesity. But parenting style affected obesity regardless of income level.More than one-third of American children are overweight or obese according to the American Heart Association. Exploring factors at home that may be fueling this public health concern could lead to better prevention and interventions, Kakinami said.Story Source:The above story is based on materials provided by American Heart Association. Note: Materials may be edited for content and length.

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Canadian drinking-age laws have significant effect on deaths among young males

A recent study by a University of Northern British Columbia-based scientist associated with the UBC Faculty of Medicine and UNBC’s Northern Medical Program demonstrates that Canada’s drinking-age laws have a significant effect on youth mortality.The study was published in the international journal Drug and Alcohol Dependence. In it, Dr. Russell Callaghan writes that when compared to Canadian males slightly younger than the minimum legal drinking age, young men who are just older than the drinking age have significant and abrupt increases in mortality, especially from injuries and motor vehicle accidents.”This evidence demonstrates that drinking-age legislation has a significant effect on reducing mortality among youth, especially young males,” says Dr. Callaghan.Currently, the minimum legal drinking age is 18 years of age in Alberta, Manitoba, and Qubec, and 19 years in the rest of the country. Using national Canadian death data from 1980 to 2009, researchers examined the causes of deaths of individuals who died between 16 and 22 years of age. They found that immediately following the minimum legal drinking age, male deaths due to injuries rose sharply by 10 to 16 per cent, and male deaths due to motor vehicle accidents increased suddenly by 13 to 15 per cent.Increases in mortality appeared immediately following the legislated drinking age for 18-year-old females, but these jumps were relatively small.According to the research, increasing the drinking age to 19 years of age in Alberta, Manitoba, and Qubec would prevent seven deaths of 18-year-old men each year. Raising the drinking age to 21 years across the country would prevent 32 annual deaths of male youth 18 to 20 years of age.”Many provinces, including British Columbia, are undertaking alcohol-policy reforms,” adds Dr. Callaghan. “Our research shows that there are substantial social harms associated with youth drinking. These adverse consequences need to be carefully considered when we develop new provincial alcohol policies. …

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Seal evolution: Sexual dimorphism in pinnipeds arose around 27 million years ago as climate changed

In the world of science, one of the most exciting things a researcher can do is pin down an answer to a widely asked question. This experience came early for Carleton University graduate Thomas Cullen, who made a discovery about pinnipeds — the suborder that makes up seals, sea lions and walruses — while doing research for his Master’s degree under the supervision of Canadian Museum of Nature palaeontologist Dr. Natalia Rybczynski.His discovery, published today in the journal Evolution, relates to sexual dimorphism (a large variance in size between males and females), in a variety of pinniped species. Males in many species of pinnipeds are often much larger than their female counterparts, in some cases more than twice as large, and this has implications for how they mate and behave.Dimorphic pinnipeds such as the Steller’s Sea Lion and Northern Fur Seal typically mate in a harem, with one male pinniped presiding over a larger community of female mates. This behavior is not typically seen in non-dimorphic pinnipeds such as the Ringed Seal, and so sexual dimorphism is intimately linked with mating style.Researchers have long puzzled over both why sexual dimorphism exists in many pinniped species and when this trait evolved. When Cullen examined fossils of an extinct pinniped with Rybczynski, he discovered an incontrovertible answer to the question of when. He was able to examine it there before analyzing the data at Carleton in a lab headed by his other thesis supervisor, Prof. Claudia Schrder-Adams.Skull of Enaliarctos emlongi, an early pinniped ancestor. Cullen examined and analyzed the characteristics of this fossil for his study on the evolution of sexual dimorphism in pinnipeds.”We were examining a fossil of a pinniped that was previously thought to be a juvenile, but we looked at it again and found that, based on its skull structure, it was likely an adult,” says Cullen. This discovery, coupled with analyses comparing this fossil to others of the same species as well as modern dimorphic species, proved that the fossil belonged to a sexually dimorphic species.The fossil in question, the skull of an early pinniped ancestor called Enaliarctos emlongi, was discovered in the late 1980s off the coast of Oregon. …

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Making biodiverse agriculture part of a food-secure future

Is biodiverse agriculture an anachronism? Or is it a vital part of a food-secure future?Given the need to feed an estimated 2.4 billion more people by the year 2050, the drive toward large-scale, single-crop farming around the world may seem inexorable.But there’s an important downside to this trend, argues Timothy Johns, Professor of Human Nutrition at McGill University in Montreal, in a paper to be presented Feb. 15, at the annual meeting of the American Association for the Advancement of Science in Chicago.Diets for most people around the world are becoming increasingly limited in biological and nutritional diversity. “Large-scale agriculture is characteristically simplified and less diverse than small-holder agriculture,” Prof. Johns cautions. “This is true in genetic, ecological and nutritional terms.”Small farmers, by contrast, in many places continue to grow a range of species and multiple varieties that form the basis of their diet and nutrition. Use of a range of wild species of fruit, vegetables, condiments and medicines, as well as wild animal-sourced foods, increase the likelihood that subsistence farmers with access to natural ecosystems meet their nutrition and health needs.The problem is that smallholder farmers in developing countries often have low productivity and little likelihood of generating the profits needed to rise above poverty level, says Prof. Johns, who directs the McGill Canadian Field Studies in Africa program. In particular, the smallholder farms in sub-Saharan Africa, which account for more than 90 percent of agricultural production and the primary livelihood of 65 percent of the population, need to be more productive.When they have access to improved technology, however, smallholder farmers can be both more productive and more sustainable than large-scale, intensive agriculture. Using family members in farming reduces labor and supervision costs, while a more intimate knowledge of the local soil, plants and animals enables smallholders to maximize output. …

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Environmental impact of Ontario corn production assessed

Researchers at the University of Guelph examined the energy use and greenhouse gas (GHG) emissions associated with corn production in Ontario. Their findings are published today in the Agricultural Institute of Canada’s (AIC) Canadian Journal of Soil Science.The study reports estimated county-level energy and GHG intensity of grain corn, stover and cob production in Ontario from 2006-2011. According to the paper’s authors, most of the energy used during corn production comes from the use of natural gas and electricity during grain drying; the production and application of nitrogen fertilizers (which are also associated with GHG emissions); and the use of diesel fuel during field work.”Corn is a major economic crop in North America, and the renewable fuels developed from corn production are frequently used to mitigate the GHG emissions from fossil fuel use,” explained Susantha Jayasundara, lead author of the paper.”Assessing the GHG and energy intensity of corn production helps identify opportunities for efficiency and aids in improving the GHG mitigation potential of corn-derived renewable fuels,” continued Jayasundara. The authors note that reducing GHG intensity and improving energy efficiency during corn production can be achieved through the use of field-drying corn hybrids, reduced tillage and diminished nitrogen inputs.The article, “Energy and Greenhouse Gas Intensity of Corn (Zea Mays L.) in Ontario: A regional assessment,” by Susantha Jayasundara, Claudia Wagner-Riddle, Goretty Dias and Kumudinie Kariyapperuma, is available Open Access in the Canadian Journal of Soil Science.”Given the environmental and economic benefits of renewable fuels and the proliferation of their use in Canada, it is important to more fully understand the environmental impacts of their associated agricultural production,” added Serge Buy, CEO of AIC. “Essential studies such as this are of national significance and are certainly evidence of the need for targeted federal investments in agricultural science.”Story Source:The above story is based on materials provided by Canadian Science Publishing (NRC Research Press). Note: Materials may be edited for content and length.

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Nine steps to save waterways and fisheries identified by researchers

The key to clean water and sustainable fisheries is to follow nine guiding principles of water management, says a team of Canadian biologists.Fish habitats need ecosystems that are rich in food with places to hide from predators and lay eggs, according to the framework published today in the journal Environmental Reviews.Humans have put key freshwater ecosystems at risk because of land development and the loss of the vegetation along rivers and streams, says John Richardson, a professor in the Dept. of Forest and Conservation Sciences at the University of British Columbia, one of 15 freshwater biologists who created the framework to help protect fish and ecosystems into the future.”Fish are strongly impacted when nutrients, sediments or pollutants are added to their habitat. We cannot protect fish without maintaining a healthy freshwater ecosystem,” says Richardson, who led the policy section on protecting fish habitats. Other policy sections addressed areas such as climate change and biodiversity.Connecting waterways are also critical for healthy ecosystems, says Richardson. “If fish can’t get to breeding or rearing areas because of dams, culverts, water intakes or other changes to their habitats, then the population will not survive,” he says.With more pressure on Canada’s freshwater ecosystems, Richardson and his colleagues wanted to create a framework of evidence-based principles that managers, policy makers and others could easily use in their work. “It’s a made in Canada solution, but the principles could be applied anywhere in the world,” he says.BACKGROUNDERHealthy freshwater ecosystems are shrinking and reports suggest that the animals that depend on them are becoming endangered or extinct at higher rates than marine or terrestrial species, says Richardson. Humans also depend on these ecosystems for basic resources like clean drinking water and food as well as economic activity from the natural resource sector, tourism and more.The components of a successful management plan include:Protect and restore habitats for fisheries Protect biodiversity as it enhances resilience and productivity Identify threats to ecosystem productivity Identify all contributions made by aquatic ecosystems Implement ecosystem based-management of natural resources while acknowledging the impact of humans Adopt a precautionary approach to management as we face uncertainty Embrace adaptive management — environments continue to change so research needs to be ongoing for scientific evidence-based decision making Define metrics that will indicate whether management plans are successful or failing Engage and consult with stakeholders Ensure that decision-makers have the capacity, legislation and authority to implement policies and management plans. These recommendations are based on nine principles of ecology:Acknowledge the physical and chemical limits of an ecosystem Population dynamics are at work and there needs to be a minimum number of fish for the population to survive Habitat quantity and quality are needed for fish productivity Connecting habitats is essential for movement of fish and their resources The success of freshwater species is influenced by the watershed Biodiversity enhances ecosystem resilience and productivity Global climate change affects local populations of fish Human impacts to the habitat affect future generations of fish Evolution is important to species survival Story Source:The above story is based on materials provided by University of British Columbia. Note: Materials may be edited for content and length.

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The Chemical Safety Improvement Act of 2013 – Yet Another Obstacle to Banning Asbestos in the U.S

TheChemical Safety Improvement Act of 2013 (S. 1009)(CSIA) is a bill currently before congress. The legislation is designed to reform the Toxic Substances Control Act (TSCA) of 1976. Many public health advocates who support TSCA reform do not support the CSIA as it is currently written, believing that the chemical industry is behind the draft legislation.On July 31, 2013, Linda Reinstein, President of the Asbestos Disease Awareness Organization, and a long-time leader in the effort to ban asbestos in the U.S., testified before the Senate Environmental and Public Works Committee (EPWC) at a hearing in support of TSCA reform. According to Ms. Reinstein, the CSIA as currently drafted would do more harm to public health and the environment than good. As detailed in the ADAO position paper, the …

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Are Canadian Under Insured?

According to the Canadian Life and Health Insurance Association, more then 20 million Canadians are protected by life insurance with an average amounts owned were $156,200 for insured individuals and $312,200 for insured households. That leaves approximately 30% of individuals without important insurance protection as well insured households only having an average amount of $312,200 of life insurance, this could represent many families being underinsured in Canada. Creating awareness around the need for life insurance is paramount there are many brokers and insurance agencies in Canada available to help with your insurance needs, call a insurance professional whether you are protecting your family your business there is help out there. Author: Peter C. Choma an insurance specialist with Solutions Financial Reference: Canadian Life and Health Insurance Association. 2008 Edition …

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Participation in cardiac rehab program improves recovery in stroke patients

Oct. 16, 2013 — Stroke patients who participate in a cardiac rehabilitation program for six months make rapid gains in how far and fast they can walk, the use of weakened limbs and their ability to sit and stand, according to a study presented today at the Canadian Stroke Congress.On average, participants saw a 21-per-cent improvement in the strength and range of motion of weakened limbs; a 19-per-cent improvement in walking speed; and a 16-per-cent improvement in the distance they could walk.”There should be a seamless referral of patients with mild to moderate effects of stroke to the network of established outpatient cardiac rehab programs in Canada,” says lead researcher Dr. Susan Marzolini of Toronto Rehabilitation Institute/University Health Network. “Early referral is also important. In our study, those who started the cardiac rehab program earlier had the strongest results.”Cardiac rehabilitation incorporates exercise training (aerobic and resistance/strength training), nutrition counseling, risk factor counseling and management (lipids, blood pressure, diabetes, weight management, smoking cessation and psychosocial management,) delivered by an interprofessional health care team.All of the 120 patients who participated in the study saw improved recovery.The largest gains in walking function were among those who were referred to the program the earliest. Participants were, on average, two years post-stroke but the study included people who had experienced a stroke from three months to five years previously.In most cases, rehabilitation ends at three months post-stroke, when it has been assumed that spontaneous recovery is over and people reach a plateau, Dr. Marzolini says.For those who entered the six-month cardiac rehab program after standard care, “we didn’t see a plateau, we saw a huge improvement in the group. We’re finding even more benefits from exercise alone than we ever thought.””We have manufactured these three-month plateaus with our biases about how the brain works,” says Dr. Dale Corbett, Scientific Director of the Canadian Partnership for Stroke Recovery (CPSR), a joint initiative of the Heart and Stroke Foundation and Canada’s leading stroke research centres, which funded the study. “Recovery continues for months and years after stroke.”A 2011 audit of stroke services in Canada found that only 37 per cent of stroke patients with moderate to severe impairments receive standard rehabilitation in the weeks after stroke, despite overwhelming evidence of its benefits.”The results of this study are exciting because this exercise program is a very cost-effective intervention for improving the quality of life for those living with the effects of stroke,” says Canadian Stroke Congress Co-Chair Dr. …

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Women less likely to die after TAVI than men

Sep. 2, 2013 — Women are 25% less likely to die one year after TAVI than men, according to research presented at the ESC Congress today by Dr Mohammad Sherif from Germany. The findings suggest that TAVI might be the preferred treatment option for elderly women with symptomatic severe aortic stenosis.Dr Sherif said: “Earlier studies on the impact of gender on outcome after transcatheter aortic valve implantation (TAVI) have had conflicting results. A Canadian study reported in 641 consecutive patients that female sex is associated with a better long-term and short-term survival after TAVI.1 An Italian study of 305 high risk patients found no gender differences in composite safety and efficacy endpoints at 30 days and one year after TAVI.”2The current analysis examined gender differences in outcomes for 1432 consecutive patients from 27 centers who were enrolled in the German TAVI registry between January 2009 and June 2010. Women comprised 57.8% of the cohort. At baseline the average age of women was 83 years vs 80 years for men. Women had aortic valve gradients at baseline of 52 mmHg vs 45 mmHg for men (severe aortic stenosis is defined as gradients exceeding 40 mmHg).At baseline men had more prior myocardial infarction (22% vs 11.5%, p<0.001); more extensive coronary artery disease (36% vs 16%, p<0.001); more history of open-heart surgery (33% vs 14%, p<0.001); more peripheral vascular disease (37% vs 26%, p<0.001); and more COPD (28% vs 21%, p<0.001).</p>During the TAVI procedure, 25.2% of women had vascular complications (including iliac artery dissection, and bleeding from the puncture site requiring blood transfusion) compared to 17.2% of men (p<0.001).</p>At 30 days follow-up mortality was 7.6% for women versus 8.6% for men (p=0.55); however by one year the all cause mortality was 17.3% for women vs 23.6% for men (p<0.01). Dr Sherif said: “Our results show that mortality at 30 days was the nearly same for women and men. Women’s higher survival rate at one year could be explained by their longer life expectancy and lower rates of comorbidity in comparison to men.”</p>The investigators did a multivariate analysis to adjust for the effect of differences between women and men in demographic, procedural, and clinical variables on one year mortality. Figure 1 shows women’s survival advantage at 12 months. …

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Engaging in a brief cultural activity can reduce implicit prejudice

Aug. 22, 2013 — Social connection sparks interest in another culture; Acting on this interest improves attitudes toward that cultural group.A small cue of social connection to someone from another group — such as a shared interest — can help reduce prejudice immediately and up to six months later, according to new research published in Psychological Science, a journal of the Association for Psychological Science.”Our research shows that even a brief opportunity to take part in another group’s culture can improve intergroup attitudes even months later,” says psychological scientist and lead researcher Tiffany Brannon of Stanford University.Decades of research in psychology show that extended relationships between people from different groups — such as between roommate pairs and long-standing friends — can improve attitudes toward other groups.Even small cues like a common birthday have been shown to bring people together and lead them to share common goals and motivations. Brannon and Stanford professor Gregory Walton wanted to investigate whether such small cues might impact people’s engagement with, and attitudes toward, other groups.In the first experiment, White Canadian participants expressed greater interest in Chinese culture when their body posture was subtly mimicked by a Chinese Canadian peer in a getting-to-know-you conversation than when the peer held a neutral position. They also completed more tickets for a drawing to win Chinese cultural products, like Chinese films.The next two experiments examined the link between social connection, cultural engagement, and prejudice.White and Asian American participants showed less implicit prejudice against Latinos after they got to know a Latina peer with whom they had a common interest, such as the same favorite book, and after they worked with her on a group activity that incorporated elements of Mexican culture.Importantly, participants showed no reduction in prejudice when they worked with the Latina peer on a project related to a non-Mexican cultural group, suggesting the importance of engaging in the peer’s culture. Moreover, participants only showed reduced prejudice when they felt they had freely chosen the topic of the group activity.Surprisingly, the effects of the brief laboratory interaction lasted over time. Participants who had connected with the Latina peer and who had freely chosen the group activity topic not only expressed greater interest in interacting with Mexican Americans, but also had somewhat more positive attitudes toward illegal Mexican immigrants in an unrelated survey six months later.”It was impressive that a short interaction in a laboratory could facilitate more positive implicit attitudes immediately and better attitudes in the long-term,” observe Brannon and Walton. “The right kind of intergroup interactions, even if brief, can have lasting benefits.”Taken together, the new findings inform policies that aim to use multicultural experiences to improve intergroup relations:”Often, the expression of distinctive cultural interests by minority-group members is seen as risky, as an invitation to be perceived through the lens of a stereotype,” the researchers note. “The present research highlights the benefits that can arise when minority group members are encouraged to express and share positive aspects of their culture in mainstream settings.”This research is important in diverse countries like the U.S., Brannon and Walton argue, because people from different backgrounds routinely come in to contact with one another at workplaces, schools, and in other social institutions. But it’s important to note that the effects depend on people feeling they have freely chosen to participate and engage in cultural activities:”Our research suggests how diverse cultural interactions and experiences can improve intergroup attitudes and relationships,” say Brannon and Walton. “But it also suggests one way it can be done badly: Making people feel obligated to take part in multicultural activities can reduce their benefits.”

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Virus-derived particles target blood cancer

Aug. 13, 2013 — Ottawa researchers have developed unique virus-derived particles that can kill human blood cancer cells in the laboratory and eradicate the disease in mice with few side effects. The study is published in Blood Cancer Journal by co-senior authors Drs. David Conrad and John Bell of the Ottawa Hospital Research Institute (OHRI) and the University of Ottawa (uOttawa).While Dr. Bell and his colleagues have been investigating replicating viruses for the treatment of solid cancers for many years, with very promising results, this is the first major success they have had treating blood cancer (leukemia). It is also the first success they have had using a non-replicating virus-derived particle as opposed to a replicating virus.”Our research indicated that a replicating virus might not be the safest or most effective approach for treating leukemia, so we decided to investigate whether we could make virus-derived particles that no longer replicate but still kill cancer,” said Dr. Conrad, a hematologist conducting research in the Blood and Marrow Transplant Program at The Ottawa Hospital, and currently completing his PhD at OHRI and uOttawa in the Department of Cellular and Molecular Medicine. “We were delighted to see that this novel therapy was very safe at high doses, and worked extremely well in our laboratory leukemia models. We hope to test this in patients in the near future.”The researchers used a specific method and dose of UV light to transform regular replicating viruses into unique particles that could no longer replicate and spread, but could still enter cancer cells efficiently, kill them and stimulate a strong immune response against the cancer. These particles were able to kill multiple forms of leukemia in the laboratory, including samples taken from local patients who had failed all other therapies. …

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Researchers find home of best stem cells for bone marrow transplants

Aug. 1, 2013 — McMaster University researchers have revealed the location of human blood stem cells that may improve bone marrow transplants. The best stem cells are at the ends of the bone.It is hoped this discovery will lead to lowering the amount of bone marrow needed for a donation while increasing regeneration and lessening rejection in the recipient patients, says principal investigator Mick Bhatia, professor and scientific director of the McMaster Stem Cell and Cancer Research Institute.In a paper published online today by the journal Cell Stem Cell, his team reports that human stem cells (HSC) residing in the end (trabecular region) of the bones display the highest regenerative ability of the blood and immune system.”Like the best professional hockey players, our findings indicate blood stem cells are not all equal,” said Bhatia. “We now reveal the reason why — it’s not the players themselves, but the effect the arena has on them that makes them the highest scorers.”Bone marrow transplants have been done for more than 50 years and are routine in most hospitals, providing a life saving treatment for cancer and other diseases including leukemia, anemia, and immune disorders.Bhatia, who also holds a Canada Research Chair in Human Stem Cell Biology, said that cells surrounding the best blood stem cells are critically important, as these “stem cell neighbors” at the end of the bone provide the unique instructions that give these human blood stem cells their superior regenerative abilities.The research was funded by the Canadian Institutes of Health Research and Ontario Cancer Research Institute.

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Alcoholism could be linked to a hyper-active brain dopamine system

Aug. 2, 2013 — Research from McGill University suggests that people who are vulnerable to developing alcoholism exhibit a distinctive brain response when drinking alcohol, according to a new study by Prof. Marco Leyton, of McGill University’s Department of Psychiatry. Compared to people at low risk for alcohol-use problems, those at high risk showed a greater dopamine response in a brain pathway that increases desire for rewards.These findings, published in the journal Alcoholism: Clinical & Experimental Research, could help shed light on why some people are more at risk of suffering from alcoholism and could mark an important step toward the development of treatment options.”There is accumulating evidence that there are multiple pathways to alcoholism, each associated with a distinct set of personality traits and neurobiological features,” said Prof. Leyton, a researcher in the Mental Illness and Addiction axis at the Research Institute of the McGill University Health Centre (RI-MUHC). “These individual differences likely influence a wide range of behaviors, both positive and problematic. Our study suggests that a tendency to experience a large dopamine response when drinking alcohol might contribute to one (or more) of these pathways.”For the study, researchers recruited 26 healthy social drinkers (18 men, 8 women), 18 to 30 years of age, from the Montreal area. The higher-risk subjects were then identified based on personality traits and having a lower intoxication response to alcohol (they did not feel as drunk despite having drunk the same amount). Finally, each participant underwent two positron emission tomography (PET) brain scan exams after drinking either juice or alcohol (about 3 drinks in 15 minutes).”We found that people vulnerable to developing alcoholism experienced an unusually large brain dopamine response when they took a drink,” said Leyton. “This large response might energize reward-seeking behaviors and counteract the sedative effects of alcohol. …

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Declining sea ice strands baby harp seals

July 22, 2013 — Young harp seals off the eastern coast of Canada are at much higher risk of getting stranded than adult seals because of shrinking sea ice cover caused by recent warming in the North Atlantic, according to a Duke University study.”Stranding rates for the region’s adult seals have generally not gone up as sea ice cover has declined; it’s the young-of-the-year animals who are stranding (those less than one year old),” said David Johnston, a research scientist at Duke’s Nicholas School of the Environment.”And it’s not just the weakest pups — those with low genetic diversity and presumably lower ability to adapt to environmental changes — that are stranding,” he said. “It appears genetic fitness has little effect on this.”The study, published online this week in the peer-reviewed open-access journal PLoS One, is the first to gauge the relative roles that genetic, environmental and demographic factors such as age and gender may be playing in harp seal stranding rates along the U.S. and Canadian east coasts in recent years.Harp seals rely on stable winter sea ice as safe platforms to give birth and nurse their young until the pups can swim, hunt and fend off predators for themselves. In years of extremely light ice cover, entire year-classes may be disappearing from the population, Johnston said.The new study complements a Duke-led study published last year that found seasonal sea ice cover in all four harp seal breeding regions in the North Atlantic has declined by up to 6 percent a decade since 1979, when satellite records of ice conditions in the region began.To expand upon the earlier study, Johnston and four colleagues at the Duke University Marine Lab compared images of winter ice from 1992 to 2010 in a major whelping region off Canada’s east coast, the Gulf of St. Lawrence, with yearly reports of dead harp seal strandings along the U.S. northeast coast that were grouped by gender and estimated age of the seal.The analysis revealed a significant difference: In years when ice cover was reduced, stranding rates for younger seals rose sharply, even though stranding rates for adult seals remained relatively stable.The researchers also compared DNA samples from 106 harp seals that had been stranded ashore with those from seals that had accidentally been caught by fishing boats in the region during the same period.”We used measures of genetic diversity to determine if the dead seals that came ashore were less fit than the presumably healthy ones that had been caught by fishermen, but found no difference,” said Thomas Schultz, director of Duke’s Marine Conservation Molecular Facility. “The stranded animals appear to have come from a genetically diverse population, and we have no evidence to suggest that genetic fitness played a role in their deaths.”The analysis also showed that male seals stranded more frequently than females during the study period, and that this relationship was strongest during light ice years.”Our findings demonstrate that sea ice cover and demographic factors have a greater influence on harp seal stranding rates than genetic diversity,” said Brianne Soulen, who co-led the study while she was a master’s degree student in marine ecology at Duke.Kristina Cammen, a Duke Ph.D. student who also co-led the study, said the findings “provide more context for what we’re seeing in high-latitude species in general. The effects of climate change are acting on younger animals; it’s affecting them during the crucial first part of their life.”

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Genetic changes that may contribute to the onset of schizophrenia identified

July 16, 2013 — Scientists from the Centre for Addiction and Mental Health (CAMH) have discovered rare genetic changes that may be responsible for the onset of schizophrenia. Several of these same genetic lesions had previously been found to have causal links to autism spectrum disorder (ASD). This discovery gives new support to the notion that multiple rare genetic changes may contribute to schizophrenia and other brain disorders.This discovery also suggests that clinical DNA (genome-wide microarray) testing may be useful in demystifying one of the most complex and stigmatized human diseases. The study is published in the current issue of Human Molecular Genetics, and was funded by the Canadian Institutes of Health Research (CIHR).In the first study of its kind, scientists at CAMH and The Centre for Applied Genomics (TCAG) at The Hospital for Sick Children analyzed the DNA of 459 Canadian adults with schizophrenia to detect rare genetic changes of potential clinical significance.”We found a significant number of large rare changes in the chromosome structure that we then reported back to the patients and their families,” said Dr. Anne Bassett, Director of CAMH’s Clinical Genetics Research Program and Canada Research Chair in Schizophrenia Genetics and Genomic Disorders at the University of Toronto. “In total, we expect that up to eight per cent of schizophrenia may be caused in part by such genetic changes — this translates to roughly one in every 13 people with the illness.” These include several new discoveries for schizophrenia, including lesions on chromosome 2.The research team also developed a systematic approach to the discovery and analysis of new, smaller rare genetic changes leading to schizophrenia, which provides dozens of new leads for scientists studying the illness. “We were able to identify smaller changes in chromosome structure that may play an important role in schizophrenia — and that these often involve more than one gene in a single person with the illness,” added Dr. Bassett, who is also a Clinician Scientist in the Campbell Family Mental Health Research Institute.”Moving forward, we will be able to study common pathways affected by these different genetic changes and examine how they affect brain development — the more we know about where the illness comes from, the more possibilities there will be for the development of new treatments.””CIHR is pleased to support researchers whose work aims at demystifying the causes of schizophrenia,” said Dr. Anthony Phillips, Scientific Director of the CIHR Institute of Neurosciences, Mental Health and Addiction. “We hope Canadians who live with schizophrenia will eventually benefit from these important findings.”Several of the genes and pathways discovered in this study of schizophrenia have also been identified to be important in causing ASD. …

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Genomic atlas of gene switches in plants provides roadmap for crop research

June 30, 2013 — What allows certain plants to survive freezing and thrive in the Canadian climate, while others are sensitive to the slightest drop in temperature? Those that flourish activate specific genes at just the right time — but the way gene activation is controlled remains poorly understood.A major step forward in understanding this process lies in a genomic map produced by an international consortium led by scientists from McGill University and the University of Toronto and published online today in the journal Nature Genetics.The map, which is the first of its kind for plants, will help scientists to localize regulatory regions in the genomes of crop species such as canola, a major crop in Canada, according to researchers who worked on the project. The team has sequenced the genomes of several crucifers (a large plant family that includes a number of other food crops) and analyzed them along with previously published genomes to map more than 90,000 genomic regions that have been highly conserved but that do not appear to encode proteins.”These regions are likely to play important roles in turning genes on or off, for example to regulate a plant’s development or its response to environmental conditions,” says McGill computer-science professor Mathieu Blanchette, one of the leaders of the study. Work is currently underway to identify which of those regions may be involved in controlling traits of particular importance to farmers.The study also weighs in on a major debate among biologists, concerning how much of an organism’s genome has important functions in a cell, and how much is “junk DNA,” merely along for the ride. While stretches of the genome that code for proteins are relatively easy to identify, many other ‘noncoding’ regions may be important for regulating genes, activating them in the right tissue and under the right conditions.While humans and plants have very similar numbers of protein-coding genes, the map published in Nature Genetics further suggests that the regulatory sequences controlling plant genes are far simpler, with a level of complexity between that of fungi and microscopic worms. “These findings suggest that the complexity of different organisms arises not so much from what genes they contain, but how they turn them on and off,” says McGill biology professor Thomas Bureau, a co-author of the paper.

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Beliefs about causes of obesity may impact weight, eating behavior

June 18, 2013 — Whether a person believes obesity is caused by overeating or by a lack of exercise predicts his or her actual body mass, according to new research published in Psychological Science, a journal of the Association for Psychological Science.Obesity has become a pressing public health issue in recent years, with two-thirds of U.S. adults classified as overweight or obese and similar trends unfolding in many developed nations. Researchers Brent McFerran of the Ross School of Business at the University of Michigan and Anirban Mukhopadhyay of Hong Kong University of Science and Technology wondered whether individual beliefs might play a role in these trends.From an initial online survey, they discovered that people seem to subscribe to one of two major beliefs about the primary cause of obesity:”There was a clear demarcation,” says McFerran. “Some people overwhelmingly implicated poor diet, and a roughly equal number implicated lack of exercise. Genetics, to our surprise, was a far distant third.”McFerran and Mukhopadhyay wanted to dig deeper to see if the pattern could be replicated and, if so, what implications it might have for behavior. They conducted a series of studies across five countries on three continents.Data from participants in Korea, the United States, and France showed the same overall pattern: Not only did people tend to implicate diet or exercise as the leading cause of obesity, people who implicated diet as the primary cause of obesity actually had lower BMIs than those who implicated lack of exercise.”What surprised me the most was the fact that we found lay theories to have an effect on BMI over and above other known factors, such as socio-economic status, age, education, various medical conditions, and sleep habits,” says McFerran.The researchers hypothesized that the link between people’s beliefs and their BMI might have to do with how much they eat.A study with Canadian participants revealed that participants who linked obesity to lack of exercise ate significantly more chocolates than those who linked obesity to diet. And a study with participants in Hong Kong showed that participants who were primed to think about the importance of exercise ate more chocolate than those primed to contemplate diet.These findings provide evidence that our everyday beliefs about obesity may actually influence our eating habits — and our body mass.According to Mukhopadhyay, this is “the first research that has drawn a link between people’s beliefs and the obesity crisis, which is growing as fast as people’s waistlines are.”The new findings suggest that, in order to be effective, public health campaigns may need to target people’s beliefs just as much as they target their behaviors.This research was supported by a grant from the Social Sciences and Humanities Research Council of Canada and Hong Kong Research Grants Council Grant CERG 642810.

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