By: Abi Kirubarajan
With midterms looming and the temperature plummeting, it’s easy to forgo walks outside and other physical activity. However, the benefits of exercise are not limited to the body as physical activity also ameliorates mental health.
Unfortunately, stress is a major issue for today’s university student. From strenuous examinations to living away from home, university students do not have it easy. According to the National Institute of Mental Health, 30 percent of university students have symptoms of depression that affect day-to-day activity. In addition, a 2008 survey found that over 40 percent of college students are stressed often, with over 20 percent of students feeling stressed for the majority of their day.
However, according to a recent McMaster study, less than half of Canadians use exercise to cope with stress and anxiety.
Researchers from the Department of Family Medicine, Psychiatry and Behavioral Neurosciences, as well as the Department of Kinesiology, used data from over 36,000 Canadian to find their results. Exercise, out of thirteen possible coping behaviors, was ranked to be the eighth most popular. Only 40 percent of Canadians stated that they exercise regularly to purge anxiety. More popular coping mechanisms included communicating with friends, problem-solving, denial and attributing failures to others. Exercise as a stress-reliever was found to be more common in young, female, single and non-smoking demographics. The study also found that people who exercised regularly were less like to abuse alcohol or drugs, in pursuit of coping mechanisms.
John Cairney, a lead investigator, said, “we know stress levels are high among Canadians, and that exercise is effective at managing stress and improving health and well-being, so the fact exercise is number eight and that less than half of the population use it is worrisome.”
Exercise is a known stress-reliever, as it floods the body with endorphins. Endorphins are neurotransmitters that inhibit pain and reduce stress. They trigger feelings of happiness, by also modulating appetite, releasing sex hormones and enhancing immune response. Moreover, regular workouts ease the physical symptoms of stress. For example, exercise relaxes tense muscles and tissue, alleviating pain from stress-related neck aches and back pains. Exercise also helps individuals sleep sounder, combatting the insomnia that can arise from anxiety. In addition, exercised muscles generate copious amounts of a protein known as PGC-1(alpha)1. This protein eliminates stress-related neurochemicals, such as kyneurenine, in the brain. When a Swedish study genetically modified animals to contain this protein, they found that the GMO animals were less likely to get depressed and anxious in unsettling environments.
Thus, it’s a shock that a majority of Canadians do not take advantage of exercise to combat stress. So next time you feel overwhelmed about exams or relationships, consider taking a walk. It will not only clear your head, but also trigger a plethora of physiological responses to help you feel better.
As Cairney said, “exercise as a coping strategy for stress can be a ‘win-win’ situation.”
Avril-Lynn Ding
The Meducator
In an era where overweight, obesity, and physical inactivity are increasing health concerns, diabetes is emerging as a global epidemic. Type 2 diabetes accounts for about 90 per cent of diabetes cases. One of the world’s most commonly prescribed drug for type 2 diabetes is metformin. Approximately 120 million people worldwide, including two million in Canada, use the medication to control their disease. Although the drug has been in use for over 50 years, its mechanism of action remained a mystery. While doctors knew it needed to interact with insulin in order to be effective and it couldn’t lower blood sugar levels on its own, how and why the process occurs had remained unexplained.
Researchers at McMaster University were the first to propose an answer with the discovery that metformin operates on fat metabolism in the liver. The study, published in Nature Medicine on Nov. 4, was led by Dr. Gregory Steinberg, an associate professor in the Department of Medicine. Rather than assuming the drug directly reduced glucose levels, the researchers formed their hypothesis based on the principle that excess fat in insulin-sensitive organs, such as the liver and skeletal muscle, is associated with insulin resistance.
From previous studies, researchers know that metformin activates the metabolic sensor AMP-activated protein kinase (Ampk), an enzyme involved in fat metabolism. Ampk can deactivate two forms of the protein acetyl-CoA carboxylase (Acc), which increase fat production and reduce fat breakdown in their active forms.
In their study, the research team examined mice with a mutation in Acc that causes the proteins to become “immune” to deactivation by Ampk. However instead of becoming obese, the mutant mice were found to exhibit signs of fatty liver and pre-diabetes. This indicates that inactivity of Ampk results in high blood sugar, or alternatively, metformin’s activation of the Ampk pathway is linked to the drug’s role in diabetes.
For further experimentation, the researchers fed a group of normal and mutant mice with a high-fat diet to induce obesity. They then treated both groups with a daily metformin dose of 50 mg per kg of body weight, equivalent to therapeutic metformin doses for humans. While the drug was effective in reducing blood glucose levels in normal mice, it failed to have an effect on obese mutant mice. The observation that metformin was unable to lower blood sugar without reducing fat concentration in obese mice demonstrates that the drug does not directly affect sugar metabolism.
"The key is that metformin doesn't work to lower blood glucose by directly working on the glucose,” said Steinberg. “It works on reducing harmful fat molecules in the liver, which then allows insulin to work better and lower blood sugar levels.”
The study’s findings have great implications in the treatment of type 2 diabetes by pinpointing the biological process through which metformin lowers blood glucose level. As the drug remains the main therapeutic option for treating type 2 diabetes, understanding its precise mechanism of action and flaws will allow researchers to develop combination therapies and personalized treatments.
Further research is required to translate the results from rodents to humans, as not all clinical trials demonstrate metformin has a clear lipid-lowering effect in humans.
Avrilynn Ding
The Meducator
Although antibiotic resistance has been identified as a problem since the first introduction of penicillin, it has recently emerged as a serious public health concern.
Currently, one in 12 adults in Canadian hospitals are infected with bacterial microbes that are immune to most or all available sildenafil antibiotics. A report released by the Ontario Medical Association in March recommended governments to establish regulations to combat antibiotics overuse in medicine and agriculture. Ironically, while antibiotic resistance is a growing threat, the pharmaceutical industry largely abandoned antibiotics development in favour of researching treatments for other diseases. The majority of antibiotics used today were discovered before 1960, and target limited pathways in bacteria.
To address the issue, researchers at McMaster University recently developed a novel approach to screening for new antibiotics. Dr. Eric Brown, a professor in the Department of Biochemistry and Biomedical Sciences, led the study, published in Nature Chemical Biology. Rather than searching for antibiotics under conventional nutrient-rich conditions in the laboratory, researchers targeted bacteria growth under nutrient-limited conditions that closer resemble conditions in the human body that bacteria face during infections.
“Convention says you try to kill bacteria under the richest growth condition that you can create in the laboratory,” Brown said.
“And yet we know that life is not that kind to bacteria when they are infecting the human body. They actually struggle quite a bit.”
The study focused on antibiotics against Escherichia coli, a common bacterium used in research. The researchers used a medium containing four salts, supplemented by 0.4% glucose and 20mM ammonium chloride, to create a growth environment lacking the vitamins and amino acids the bacteria require. They then screened for antibacterial compounds by shifting through a library of 30,000 synthetic molecules and testing for chemicals that can block E. coli’s ability to synthesize its own essential nutrients.
Using the method, the research team discovered and characterized three new antibacterial compounds, designated as MAC168425, MAC173979 and MAC13772. Each chemical acts on a different pathway in E. coli to disrupt its ability to create or use a particular nutrient. MAC168425 interferes with the metabolism of glycine, a major amino acid used to build many proteins. MAC173979 prevents E. coli from making vitamin B9 by decreasing the biosynthesis of an intermediary molecule, while MAC173979 prevents the biosynthesis of vitamin B7 by inhibiting a key enzyme. In addition to the three molecules, researchers also identified 68 other chemicals that showed active antibiotic properties in nutrient-limited medium.
Brown’s findings have great implications in pharmaceutics by demonstrating the possibility and feasibility of a new method for antibiotic development. Not only does it suggest an alternative process for identifying antibiotic chemicals, it also opens research to a new class of antibiotics that target the nutrient synthesis mechanisms of bacteria. Although further research is required to transform the three antibiotic compounds into antibiotics, the study’s approach to discovering antibiotic chemicals has great potential to address antibiotic resistance.
By: Annie Cheung
Heavy metals ions, such as gold, are toxic to many species of bacteria. It is therefore surprising to see that the bacterium, Delftia acidovorans, can thrive on biofilms that form on top of gold deposits. Researchers at McMaster University have found a novel mechanism in which this gold-resistant bacterium is able to protect itself from this toxicity.
The research team led by Dr. Nathan Magarvey at Michael G. Degroote Institute for Infectious Disease Research has discovered that D. acidovorans is able to protect itself from toxic gold ions by excreting a metabolite, delftibactin, outside of its cell wall. Delftibactin is a small molecule compound that is able to precipitate soluble gold ions into nontoxic gold nanoparticles. This defense mechanism leads to the formation of a halo of gold platelets around D. acidovorans that resemble gold nuggets one would typically find in natural geological deposits. The conversion of toxic ions into harmless gold platelets prevents gold metal ions from entering D. acidovorans cells. “This finding is the first demonstration that a secreted metabolite can protect against toxic gold and cause gold biomineralization”, states Dr. Magarvey in his paper.
The discovery of delftibactin involved genome analysis to identify the gene responsible for this unique protection mechanism. Researchers grew a colony of D. acidovorans cells lacking the gene that codes for delftibactin A, the protein responsible for delftibactin synthesis. They found that the delftibactin-deficient bacteria struggled to survive in a medium supplied with toxic gold ions, while the addition of delftibactin A to the colony enabled the bacteria’s survival. Delftibactin A may potentially be used someday to identify gold-rich streams and rivers, or to precipitate gold from water.
The study did not specifically look into the viability of using the bacteria in gold-mining applications. Instead, Dr. Magarvey is more interested in understanding the chemical properties of the metabolite. In collaboration with Dr. Bin Ma at the University of Waterloo, Dr. Magarvey has recently developed a bioinformatics method that enables the discovery of elusive bioactive metabolites, such as delftibactin, in bacteria. Dr. Magarvey hopes to use this method to further understand the function of metabolites in bacteria found in humans and their possible applications in medicine.
By: Maryssa Barras
I know what you’re thinking, and no, this is not the movie. SixthSense is an up-and-coming technology created by Pranav Mistry of MIT’s Media Lab. SixthSense is a wearable gestural interface, which means that you an wear a computer and interact with it using hand gestures.
Pranav Mistry came up with the concept a few years ago, and in 2009, when the first prototype was released, it won the Invention Award by Popular Science, and Pranav won the TR35 2009 Young Inventor Under 35 Award.
SixthSense is fairly simple. Its hardware consists of five individual devices, a camera (or webcam), a projector, a mirror, a microphone and a mobile computing device, all connected together.
How does this work, you ask? Well, the wearer puts the connected hardware around his/her neck, with the camera and projector facing outwards, and then he or she puts color markers – basically anything that would give your thumbs and index fingers different colors, like wire tape – on their fingers. The user would then turn on their device and compute away.
It works exactly like any other computer or laptop, only you can take it anywhere. For example, if you were walking home and saw a nice landscape you wanted to take a picture of, all you’d have to do is stop, turn in its direction and make a rectangle with your thumbs and index fingers. Or, if you wanted to surf the Internet, just turn and face a wall, flick you fingers, and on comes the projector with a full desktop projected on the wall. Done. Easy as that, and you are in full control.
With the new year, you can always expect a lot of new technology, and although SixthSense is not available on the market, there are step-by-step instructions on doing it yourself, as well as official beta software issued by the inventor, available online for those of you who are really tech savvy, and all for about $350.
By: Mohsin Ali
It may be as simple as probiotics, suggests a study led by McMaster professor Dr. Bradley Johnston. His colleagues analyzed twenty randomized-controlled trials, totalling almost 4,000 patients. They asked whether the use of probiotics—‘good’ bacteria found in yogurts, powders, or capsules—influenced rates of diarrheal illness related to the bacterium Clostridium difficile. Their main finding: new cases of C. difficile–associated diarrhea in hospital patients was reduced by 66 per cent, amounting to 33 cases prevented per 1,000 patients.
This effect is significant given the burden of C. difficile on the healthcare system: it causes illness and death in hospitalized adults. In fact, almost half of all diarrheal illness in hospitals is associated with C. difficile, and it is a major concern for the Ontario Ministry of Health and Long-Term Care, too, who tracked 75 outbreaks in 47 hospitals from 2009–2011.
Dr. Johnston, who is also a clinical epidemiologist at the Hospital for Sick Children in Toronto, echoes these concerns. He noted that a 2010 University of Ottawa study found one patient for every 10 infected by C. difficile died of the infection, and therefore “[m]inimizing or even preventing C. difficile among vulnerable patients is a high priority for making every hospital as safe as possible for all patients. It’s an important public health issue.”
Dr. Mark Loeb, division director of Infectious Diseases in the Michael G. DeGroote School of Medicine at McMaster, agrees. As a co-author for the study, which was published in the Annals of Internal Medicine, both he and Dr. Johnston emphasized the importance of integrating probiotics into the diets of hospitalized patients. Older patients are especially at risk when using antibiotics, which deplete both ‘good’ and ‘bad’ bacteria, providing a niche for C. difficile to thrive.
Probiotics help reintroduce healthy bacteria, and though they are not a magic bullet, said Dr. Johnston, they are an effective, safe and relatively inexpensive approach to prevent C. difficile–associated diarrheal illness.
By: Bernard Ho
In patients experiencing diabetes mellitus, the body is either unable to produce insulin or is resistant to the body’s own insulin. The usual treatment for this ailment is exercise and dietary modifications, but when the disease becomes more severe, exogenous insulin injections must be given on a consistent basis in order to regulate blood sugar levels. However, past observational studies have shown that higher insulin levels are associated with an increased risk of cardiovascular disease. Thus, insulin injections to treat diabetes may lead to problems elsewhere in the body.
Recently, researchers at McMaster University put this belief to the test. Dr. Hertzel Gerstein, a professor at McMaster’s DeGroote School of Medicine and deputy director of the Population Health Research Institute, conducted a randomized control trial along with several other researchers to determine whether exogenous insulin increases the risk of cardiovascular disease. In the study, over 12,500 people from 40 countries, who were at high risk for or were in the early stages of Type II diabetes, were randomized to either one daily injection of insulin or no insulin for an average of six years. After analyzing the data, researchers found no difference amongst the two groups in cardiovascular outcomes.
“People have been debating the question of whether there are adverse consequences to long-term insulin use for years,” said Gerstein. “This study provides the clearest answer yet to that question: no, there are not.” Indeed, the hazard ratio for heart disease between the treatment groups was 1.02, meaning that those who were given insulin experienced cardiovascular outcomes at almost the same rate as those who were not. Moreover, the participants of the study given insulin maintained normal fasting blood sugar levels, below 6 mmol/L.
A second key finding discovered by the researchers was that those who do not yet have diabetes, but are at a high risk of developing the illness and who receive daily insulin injections, have a 28% lower chance of developing the disease, even after the injections are stopped. This suggests that some people who start insulin injections won’t necessarily be looking at treatment for the rest of their lives. The study also confirmed the presence of two previously known side effects of exogenous insulin – hypoglycemia (low blood sugar) and modest weight gain. Both were considered to be minor from a medical perspective, with participants experiencing a small risk of hypoglycemia and gaining an average of 3.5 pounds during the study.
This study was part of a larger study known as the ORIGIN (Outcome Reduction with Initial Glargine Intervention) Trial, led by Dr. Gerstein and Dr. Salim Yusuf, that also looked at the effects of omega-3 fatty acids on cardiovascular diseases. The ORIGIN Trial has since been completed and the results have been published in the New England Journal of Medicine.
By: Ilia Ostrovski
Medical advances are continuing to push the boundary of how long the average person should expect to live. This trend of increasing life expectancy underscores the importance of measuring quality of life as individuals age.
With this issue in mind, three Canadian researchers submitted a joint proposal to the Canadian Institute of Health Research (CIHR) to launch one of the largest clinical explorations of the topic to date. In November 2001, their proposal was accepted. On Sept. 28, after eleven years of planning, the study’s lead principal investigator, Parminder Raina of McMaster, finally announced the official grand opening of the Canadian Longitudinal Study on Aging (CLSA).
Raina is the director of McMaster’s Evidence-based Practice Center and specializes in clinical epidemiology and biostatistics. His area of interests is the epidemiology of aging, injury and knowledge transfer. Before the launch of CLSA, Raina was the lead investigator for the Hamilton site of the Canadian Study of Health and Aging, which explored the epidemiology of dementia. Currently, he holds the Raymond and Margaret Labarge Chair in Research and Knowledge Application for Optimal Aging.
Raina was joined in the celebration by some of the 160 researchers from all across the country who are collaborating on this innovative project. The study’s co-principal investigators are Christina Wolfson from McGill University and Susan Kirkland from Dalhousie University. This study will collect data from 50,000 men and women between the ages of 45 and 85 and will continue to follow up with its subjects for at least 20 years.
Unlike previous longitudinal studies on similar topics, CLSA will take a multi-faceted approach to examining the aging process. By analyzing the gradual change of psychological, social, medical and biological parameters, the investigators hope to address a breadth of important issues concerning the maintenance of good health in the latter years of life.
CLSA will use 11 data collection sites, four telephone interview centres and three data analysis facilities across the country. The McMaster Innovation Park is one of CLSA’s particularly prominent facilities. It houses the study’s National Coordinating center, the Bioanalysis and Biorepository Center and the McMaster Data Collection Site.
"The CLSA is more than a study,” said Yves Joanette, the Scientific Director of CIHR’s Institute of Aging. “It represents a unique platform that will be used by researchers from all disciplines and fields for decades to come thanks to the range of information that will be gathered and analyzed."
By: Johnny-Wei Bai
For years, people have recognized that physical exercise improves cardiovascular and mental health, controls weight gain, and enhances academic performance. In fact, some even estimate that 20 per cent of premature deaths could be prevented by regular physical activity. Despite the benefits of physical activity, recent studies show that 85 per cent of Canadian adults do not fulfill the recommended 150 weekly minutes of moderate-to-vigorous exercise. Looking at the bustling activeness in young children, one may wonder at what stage of development this drop in exercise level comes about. Well, it is known that decline in physical activity occurs most drastically in adolescents transitioning into early adulthood, especially from high school into college/university.
To further explore this phenomenon, a recent research study was headed by Matthew Kwan, a post-doctoral fellow at McMaster University's Department of Family Medicine. Participants for this prospective cohort study were recruited from the Canadian National Population Health Survey; in total, 683 adolescents of ages 12-15 were followed until they turned 25-27 years old. During this period, scientists looked at factors such as physical activity, education status, binge drinking, and smoking levels in both males and females. Comparing such a wide-range of factors allowed researchers to evaluate whether decline in physical activity is truly as big of an issue as other, more publicized health-risk factors.
Results showed that the average physical activity level across all participants decreased by a drastic 24 per cent, with a steeper decline in college/university males than in females. This difference across genders, however, may be because females in this study generally exercised less than males did, even in high school. Other health-risk behaviours, such as smoking and binge drinking, predictably increased during the high school-university transition, likely because of reduced parental influence and greater social pressures in post-secondary settings. Although levels of drinking and smoking began to plateau in later years, physical exercise levels continued to decline in adulthood.
Kwan’s findings suggest that an increase in unhealthy behaviours in early adulthood puts university and college students at greater risk of future health complications. It is commonly known that excessive smoking and drinking can cause various cancers, lung conditions, and cardiovascular diseases. McMaster researchers claim that in addition to the usual focus on preventing negative behaviour, health promotion strategies should emphasize the benefits of positive health activities such as physical exercise. Kwan called for greater efforts in targeting the decline in physical activity levels in adolescents to encourage healthy life-long habits.
