Issue 15

Cancer with Viruses?

McMaster’s Medical Research and Health Ethics Student Journal

IN THIS ISSUE Also in this issue:

A Journey through Doctor’s right to refuse the Labyrinths of Love patient treatment

We Are All Vulnerable: Perspectives on Climate Chaperones and Change and Health protein folding Examining the Increasing Loneliness and Prevalence of Hepatocellular cardiovascular Carcinoma in Canada

disease

The Diabetic Pandemic: Globalization, Industrialization, Debate on Canada’s health care and Type 2 Diabetes

Global Perspectives:

From Liver to Lover Issue 15 | April 2009

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Table of Contents

Issue 15 |April 2009

Research Articles Presidential Address

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MedWire

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Crystal Chung

MedBulletin MedQuiz

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About The McMaster Meducator The McMaster Meducator is an undergraduate medical journal that publishes articles on current topics in health research and medical ethics. We aim to provide an opportunity for undergraduate students to publish their work and share information with their peers. Our protocol strives to maintain the highest standard of academic integrity by having each article edited by a postgraduate in the relevant field. We invite you to offer us your feedback by visting our website: www.meducator.org.

Thalamus Frontal and cingulate Nuc. acc. septum cortex Hypo.

Olfactory bulb

Amyg.

VTA Substantia nigra

Special Interest: Love and Addiction Deborah Kahan, Jessica Matecki, Krina Patel, Simone Patel & Mohammas Sardar

The Diabetic Pandemic Neil Dattani and Allan Jiang

12 Hepatocellular Carcinoma Dolly Lin

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The McMaster Meducator may be contacted via our e-mail address: meduemail @learnlink.mcmaster.ca or our mailing address: B.H.Sc. (Honours) Program Attention: The McMaster Meducator Michael G. DeGroote Centre for Learning and Discovery Room 3308 Faculty of Health Sciences 1200 Main Street West Hamilton, Ontario L8N 3Z5 http://www.meducator.org

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Spinal cord

Editorial: Climate Change and Health Tyler Law

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Y

ou can’t go anywhere these days without hearing some gloomy news. The global recession is a hot topic that makes daily headlines. The media has sensationalized stimulus packages, telecast meetings of world leaders, and propagated fears of a depression. While the effects of the slowing economy can easily hit close to home, it is important to remember that many other issues plague the world and affect people globally. In an age of antibioticresistant bacterium, incurable cancers and other diseases, natural disasters and climate change, it’s easy to fall into a state of despair about the nature of things. Is there a solution? In the words of the world’s most famous British pop band, the Beatles, perhaps “All You Need is Love.”

Our fifteenth issue brings you a medley of topics. Beginning with a special interest article on love, Deborah Kahan, Jessica Matecki, Simone Patel, Krina Patel, and Mohammas Sardar, give a scientific perspective on the mechanisms and addictive effects of intimacy and affection. Neil Dattani and Allan Jiang investigate the possible link between diabetes and global socioeconomic factors. Closer to home, Dolly Lin analyzes the incidence of liver cancer and how it impacts Canada’s health care system. As an extra treat in this issue, our 2007-2008 President, Tyler Law, draws a comparison between combating climate change and implementing strategies in health care.

This is my last issue as President, and I must thoroughly acknowledge the amazing individuals who form the growing executive team for the Meducator. I am honoured to have worked with such a bright and talented group. To Jacqueline Ho, thank you for your effort and support, especially for this issue. Thanks to our meticulous editors: Veronica Chan, Randall Lau, Simone Liang, Siddhi Mathur, Navpreet Rana, Manan Shah, and Fanyu Yang – your work this year in ensuring the quality of articles was phenomenal.

Considerable thanks goes out to the creative team – Stephanie Low, Andrew Yuen, and Ran Ran – for giving the professional touch to this publication and adding the fit and finish. To Avinash Ramsaroop, thank you for your development and maintenance of the website, an invaluable channel of information and communication with our readers. Finally, I would like to thank our Junior members: Ahmad Al-Khatib, Alyssa Cantarutti, Randal Desouza, Keon Maleki, Hiten Naik, and Sangeeta Sutradhar. Your energy is refreshing and your dedication to this initiative is commendable.

Since joining the Meducator four years ago, I have seen our output and communication of information grow considerably. Please visit our website, www. meducator.org, to view past issues, find information about submitting articles, and read our MedBulletin and MedWire updates. There are still numerous ways to expand this publication further, and I am excited to see where it ventures next. On behalf of all the writers and staff, we hope you enjoy this issue.

Sincerely,

Crystal Chung B.H.Sc. IV

Meducator Staff President Crystal Chung Vice-President Jacqueline Ho Editorial Board Veronica Chan Randall Lau Simone Liang Siddhi Mathur Navpreet Rana Manan Shah Fanyu Yang Creative Director Stephanie Low Web Master Avinash Ramsaroop Public Relations Harjot Atwal Graphics & Design Ran Ran Andrew Yuen Junior Executives Ahmad Al-Khatib Alyssa Cantarutti Randal Desouza Keon Maleki Hiten Naik Sangeeta Sutradhar

Post Graduate Editors Dr. Allison B. Sekuler, BA, PhD Dr. Peter Ellis, MMED, PhD Dr. Hertzel C. Gernstein, MD, MSc, FRCPC

www.meducator.org

Presidential Address

Dear Reader,

MedWire

4 Researchers at Oxford University have completed a study of almost one million obese adults and concluded that obesity may shorten life expectancy by up to ten years.

Health officials in Massachusetts are expected to mandate that all public school students be weighed and measured once yearly so that their parents can see the trends in their growth. The purpose of this endeavour is to curb rising childhood obesity rates.

Teen pregnancy rates in the United States are on the rise for the second year in a row, according to the National Centre for Health Statistics.

After a 14 year decline, the rate has risen 4.8% in the last two years.

Several international agencies are outraged by the comments of Pope Benedict XVI, who on a recent trip to Africa condemned the use of condoms and said that they will only worsen the AIDS epidemic currently ravaging the African population.

An Alzheimer’s specialist at the University of Columbia has completed research showing that there may be a link between diabetes and increased risk of developing Alzheimer’s. Doctors have long been aware of damages to blood vessels caused by diabetes, the connection is still being studied.

Issue 15 President Obama has reversed former President George W. Bush’s 2001 block on government funded embryonic stem cell research through an executive order.

However, the Dickey-Wicker Amendment of 1996 continues to prevent researchers from creating embryos through government funding.

Researchers in Toronto have found that religious people are less likely to be a victim of stress or anxiety when in a stressful situation.

New research shows that women in bad marriages suffer serious health consequences, including a tendency to develop obesity, depression, and high blood pressure. These factors lead to heightened risk of diabetes, stroke, and heart disease.

British Columbia has become the first province to have a restriction on the amount of trans-fat that restaurants and cafeterias are allowed to serve.

The Canada Food guide recommends only a glass of juice a day because of the excessive amounts of sugar and lack of nutrients in processed juices.

A study in Nature Structural & Molecular Biology reports that scientists have been able to isolate antibodies targetting sections of the flu virus that do not mutate from year to year; suggesting that a permanent vaccine for influenza could be developed.

Clinical trials for the antibodies may begin within the next three years.

Anger has been found to trigger potentially deadly heart rhythms in certain individuals. The changes brought on by anger may lead to future arrhythmias and sudden cardiac arrest.

British and Canadian scientists recommend sufficient vitamin D intake from an early age to prevent multiple sclerosis, after studying a vitamin-D sensitive gene variant that causes multiple sclerosis.

Researchers have developed tiny polymer balls loaded with neural stem cells that can be injected into brain regions that suffered from stroke damage. The polymer balls contain the growth of the cells within the damaged area and eventually biodegrade to leave room for the development of blood vessels.

A new study by British scientists finds that children who watch the highest amounts of television (and who are generally less active) have a significantly higher risk of developing asthma.

They believe that people need to be active when they are young so that deep breathing can stretch their airways.

New programs targeted at eliminating child obesity in the UK require participation from the entire family as the focus shifts away from dieting and towards permanent lifestyle changes. Childhood obesity rates in the UK have been on the rise for the last 50 years.

While men are often accused of regarding women in bikinis as objects, new research shows that the brain areas for handling tools light up when viewing scantily clad beauties.

Brain areas for thinking about the other’s viewpoint were inactive in men who scored the highest.

MED

A recent study has found that people who keep diet diaries about their daily food intake are able to lose weight easier than people who do not.

April 2009

Swedish researchers have found that people who are obese at 18 are twice as likely to die prematurely compared to their normal weight peers.

Being obese or overweight is just as deadly as smoking.

The Ontario government is encouraging teenagers to receive a mumps booster shot. Mumps can cause serious side effects in young adults, such as pancreatitis, deafness, and meningitis.

Nearly 40% of Americans are beginning to turn to alternative and unconventional medicine for ailments such as back pain and arthritis.

Although many new mechanisms of genetic screening are constantly being developed, genetic counsellors warn that they do not necessarily need to be offered to the public. Some of the genes identify disorders that are untreatable, such as the gene for Huntington’s disease.

It is argued that patients should see counsellors before taking the tests so that they can understand their results and implications.

Researchers in London may have found a way to cure children with fatalityinducing peanut allergies.

By giving children small doses of peanut flour (~5mg) and working up to a daily dose equivalent to five peanuts, doctors may be able to induce desensitisation.

AIDS has now surpassed both tuberculosis and rabies as the number one infectious disease in China, say officials in Beijing. Rising numbers of infected patients are causing health care workers to lobby for increased awareness and preventative measures.

Researchers from the University of Minnesota have found the physiological mechanism behind how scratching relieves an itch. The study suggests the act of scratching blocks the activity of nerve cells in the spinothalamic tract that transmits itching sensations to the brain.

American researchers have identified all the 1,166 proteins in human saliva, a discovery which could prove useful for diagnosing fatal diseases, such as cancer.

Patients may soon have to spit into a cup to be diagnosed, making it easier, cheaper and painless.

A leading scientist at Oxford University has claimed that social networking websites are causing alarming changes in the brains of young users, resulting in shorter attention spans and making them more self-centred.

After the recent death of a two-month-old boy, a doctor warns that leaving a baby reclined in a car seat for an extended amount of time can lead to blocked airways and subsequent asphyxiation.

Vitamin D may help protect against the common cold. It is particularly deficient in winter, and those with low levels of it are likely to report a recent cold. In excess, Vitamine D is responsible for kidney stones and other problems.

Marijuana may increase the risk of developing an aggressive form of testicular cancer.

Chronic marijuana use affects the male reproductive system, as the risk for cancer is higher in chronic users.

Scientists of the McMaster Stem Cell and Research Institute have discovered how stem cells develop and specialize into blood cells through specific cell communication pathways.

In a groundbreaking study, British researchers have claimed to identify the gene that codes for happiness.

The individuals who carry two ‘long’ alleles of this gene focus on the positive aspects of their life and end up being more sociable and with better psychological health.

An American study has suggested that music with degrading lyrics could prompt teens to begin having sex earlier. Those who listened to music with aggressive or explicit sexual phrases were twice as likely to be sexually active.

A recent report from the Harbor-UCLA medical centre notes that gram-negative bacteria are becoming more and more resistant to current antibiotics, and warns that without increasingly aggressive research an infectious ‘superbug’ could manifest.

A study recently published in JAMA shows that the flu shot is better and more effective for North American adults than its newly available nasal spray counterpart. However, experts do still reccommend the spray for children.

Canadian scientists at Mount Sinai Hospital have found a new way to turn skin cells into stem cells. The applications of this finding are endless, and researchers are excited about the future possibilities for stem-cell therapy.

In a recent study, an international team of scientists found that eating broccoli sprouts may help tame the H. Pylori bacteria that is associated with stomach ulcers in cancer. www.meducator.org

MedWire

The HIV virus is evolving to develop mutations to evade humane responses, even as research is conducted around the globe. This should not be taken to suggest that the virus is winning the battle, but it is possible that as the virus changes, different immune responses come into play that may neutralize it.

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Issue 15

Women Less Able to Suppress Hunger

MedBulletin by Randal Desouza

When tempted bytheir favourite foods, it seems that women are less able than men to suppress their hunger, according to findings in the Proceedings of the National Academy of Sciences.

Such findings may be instrumental in explaining female obesity rates in the United States.

Researchers trying to understand the brain’s mechanisms for controlling food intake were surprised at the difference in brain response between the sexes.

To understand why some people overeat as opposed to others, researchers performed brain scans on men and women who had fasted the night before and then were then presented with their favourite foods.

The participants employed a technique known as cognitive inhibition, which they had been taught earlier, to suppress thoughts of hunger and eating. While male and female participants said that the inhibition technique decreased their hunger, brain scans showed that male brain activity decreased while the part of the female brain that responds to food remained active.

Although the women said they were less hungry when trying to inhibit their response to food, their brains were fully active in the regions that controlled their drive to eat.

Reference: Wang, H. (2009). Study: Women less able to suppress hunger than men. China View: Health. Retrieved http://news.xinhuanet.com/ english/2009-01/22/content_10701533.htm

Is Poor Sleep Quality Linked to Postpartum Depression?

MedBulletin by Hiten Naik

It is well understood that women often suffer from sleep deprivation after giving birth.

Though this is often blamed on the physical demand placed on mothers by noisy infants, poor sleep patterns can be explained by plunging estrogen and progesterone levels after childbirth. Typically, both the quantity and quality of sleep is affected. Studies have shown that a mother spends 20% more of the day awake than average during the first six postpartum weeks and spends only 81% of their total time in bed actually sleeping.

Less frequently, childbirth may also lead to postpartum depression (PPD), a psychological disorder that affects 6.5 to 13 percent of new mothers in the US, and is particularly more prevalent in women of lower socioeconomic levels. Poor sleep and depression can be considered to be distinct implications of childbirth, but is there a relationship between the two? In a recent study, researchers at Druxel University found that mothers suffering from PPD slept less and took longer to fall asleep. Those with more serious PPD symptoms suffered from less healthy sleep patterns. The role of neurotransmitters affected by poor sleep in mood regulation may account for this relationship.

Infants can be negatively affected by the poor sleep and depression of their mothers, as they often adapt to the distorted circadian rhythm patterns and receive poorer quality of care. Clinicians believe that this negative cycle can be controlled if mothers receive help from family members to care for their infants and if they practice better sleep hygiene.

Reference: Wiley-Blackwell (2008, December 24). Poor Sleep Quality Linked To Postpartum Depression. ScienceDaily. Retrieved January 4, 2009, from http://www.sciencedaily.com- /releases/2008/12/081210122236.htm.

April 2009

An Unethical Cure for Cancer?

MedBulletin by Ahmad Al-Khatib

Doctors from University College London have successfully delivered the first baby girl in the United Kingdom to have been tested before conception for a genetic form of breast cancer. The father of the child, who wishes to remain anonymous, came from a family line that has suffered for three generations from breast cancer; his grandmother, mother, sister and cousin were all diagnosed in their 20’s. Doctors at the university used pre-implantation genetic diagnosis (PGD) to screen the embryo for an altered BRCA1 gene, which would have given his daughter an 80% chance of also developing the disease. The gene normally codes for a protein that helps stop cancer before it begins to proliferate. However, the variation carried in the husband’s genome works to greatly increase the risk of mutation.

Though PGD has the potential for eliminating hereditary diseases, it has been severely criticized by ethics groups. The procedure involves testing cells from an embryo at the eight-cell stage of development for any rogue genes, such as the BRCA1 gene. If the embryo is found to be a carrier, it is discarded. As a result, Josephine Quintavalle of the campaign group Comment on Reproductive Ethics has claimed that “underlying all this is eugenics”. The use of eugenics assumes an ethical philosophy that advocates the artificial evolution of human traits to favor “desired traits”, while also eliminating hereditary diseases. Mrs. Quintavalle continues to comment that she hopes “20 years down the line we will have eradicated breast cancer – not eradicated the carriers.”

Reference: Health. 2009. Breast cancer gene-free baby born. [Online exclusive]. BBC News. Retrieved from http://news.bbc.co.uk/2/hi/ health/7819651.stm.

A Way to Erase Bad Memories?

MedBulletin by Sangeeta Sutradhar

Researchers at Toronto’s Hospital for Sick Children have developed a method to eradicate bad memories from one’s brain. The investigators hope to apply their research on fear in mice to help humans erase bad memories before they cause post traumatic stress disorder. Although the actual incident that occurred would still remain intact in one’s memory, a person would not be able to remember the fear he felt at the time, and would not associate the occurrence with the anxiety of the experience.

The cells in murien brains that store previously-experienced fear are located within the amygdala – a region of the brain that is associated with intense and instinctive emotions.

The amygdala of a mouse functions very similarly to that of a human amygdala and contains analogous fear-storing neurons.

The researchers targeted a memory protein known as CREB, which is responsible for aiding brain cells create and lock memories. In this study, a virus triggered the CREB mechanism specifically in fear-storing neurons in the amygdala. The mice were then conditioned to fear the sound. Researchers then introduced a second virus that would target the neurons that expressed the CREB fear-storing mechanism, and would eradicate those neurons by making them susceptible to a diphtheria toxin that researchers would inject into the mice.

Targeting only these neurons that stored fear for that one incident guaranteed that the brain could still remember fear, not just for that specific recollection. In the future, researchers are hoping to find a way to prevent the CREB mechanism from creating more fearful memories in post-traumatic stress disorder patients.

Reference: Hall, J. (2009, March 12). Erasing traumatic memory may be possible, researchers say. The Toronto Star. Retrieved March 12, 2009, from http://www.thestar.com/sciencetech/article/601208.

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Issue 15

Encouraging Insight into Forecasting Breast Cancer Recovery

MedBulletin by Keon Maleki

Researchers at Mount Sinai Hospital in Toronto have developed a tool named Dynamic Network Modularity (DyNeMo) that may provide the necessary information to predict the likelihood of recovery for breast cancer patients. DyNeMo examines protein interactions found within breast cancer tumours, and makes predictions on how the tumour will behave over a specific time span.

Since proteins are connected in an informational network with cancer cells and other proteins, evaluating interactions originating from these proteins provides physicians with information from the source of the cancer.

A glimpse of hope in treating breast cancer may be derived directly from DyNeMo, as the program suggests that women who survive breast cancer possess an alternative configuration in their protein network within cancer cells, relative to women with breast cancer that ultimately becomes fatal. The researchers who developed this program stress that it should be used solely for the purposes of diagnosing patients and determining whether or not the tumour is likely to yield a positive outcome or a negative outcome. Furthermore, the developers maintain that DyNeMo is intended as an effective analytical tool for breast cancer patients and their oncologists. The researchers caution to reconsider the notion that the program may be useful in discovering possible treatments. DyNeMo surpasses other prognostic technologies is in its accuracy, and its effectiveness in predicting the onset of breast cancer in early stages. A genetic researcher at Harvard Medical School claims that their findings strongly suggest that genetic inheritance is not the most significant factor in breast cancer, but rather the configuration of genes that synthesize proteins; especially how those proteins interact with cancer cells.

Ultimately, this discovery revolutionizes our knowledge of breast cancer.

Reference: “New technology holds promise for predicting breast cancer recovery.” CBC News. 2 February 2009. <http://www.cbc.ca/health/ story/2009/02/02/breast-cancer-dynemo.html>.

Medicine, Psychology and Law

MedBulletin by Alyssa Cantarutti

The recent murder of a pastor in Illinois was blamed on the accused’s deteriorating mental health. The defense stated that the accused had suffered from Lyme disease for many years and that this was the cause of his crime. However, infectious disease experts state that it is unlikely that Lyme disease can cause either violence or psychosis. Experts do admit that Lyme disease can have lingering neurological and psychological effects if left untreated, but no incidence of such extreme violence has ever been documented.

The judge and jury are faced with ethical questions in determining the extent to which the accused should be held criminally accountable for his actions. Did he commit the crime, or did he do so due to a psychotic episode? In general, some question the actual validity of this option in general, believing that whether or not an individual may have been experiencing psychosis, he or she is still a legitimate threat to society and should be dealt with accordingly.

A similar case was decided recently, involving Vincent Lee in the beheading of a Canadian man on a Greyhound bus.

Although Lee was declared competent to stand trial, his lawyers were eventually successful in using a ‘not criminally responsible’ defense and Lee was sentenced accordingly.

Thus, it is evident that there are many possibilities for the outcome of this ethical dilemma and many differing opinions regarding the applicability of medicine and clinical diagnosis to law.

Reference: DeNoon D. J. (2009). Lyme Disease and Violence: No link. WebMD: Health News. Retrieved http://www.webmd.com/news/20090310/ lyme-disease-and-violence-no-link?src=RSS_PUBLIC

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Special Interest A Journey through the Labyrinths of Love

Deborah Kahan, Jessica Matecki, Krina Patel, Simone Patel & Mohammas Sardar

Human beings have an innate and universal capacity for love. This paper will explore the mechanistic development of both short and long-term relationships, their mediation by the motivation and reward- oriented mesolimbic system and the important roles played by several neurotransmitters. These systems shed light on how changes in commitment may be mediated by hormones that promote attachment and dampen romantic passion.

Summarily,

love and

addiction are shown to be similar; both are characterized by cravings, loss of control and withdrawal.Â

L

ove poetry was first written in ancient Sumeria four thousand years ago in cuneiform on a small piece of clay (Fisher, 2004). In a study conducted on 166 different cultures worldwide, 90 percent of them showed evidence of romantic love (Fisher, 2004). This article will delve into the human capacity for love, its neurochemistry, the different types and how love changes over time. It will touch on age and its relation to love intensity, as well as the negative aspects of love. It is important to note, however, that the mechanisms of love remain largely a mystery to researchers, and no theories pertaining to the subject have been proven to be conclusive (Levitt, 2006).

Innate Capacity The capacity to love intensely is thought to be an innate human quality. One prominent researcher in the field, Helen Fisher, postulates that the capacity to love is a product of our large and complex prefrontal cortex (Fisher, 2004). Certain regions of the brain, such as the amygdala, hippocampus and caudate nucleus, are thought to be responsible for our capacity to love (Fisher, 2004, 150). These regions enable us to think in many different contexts related to our loved ones, to remember them in great detail, and to attach strong emotions to these thoughts and memories.

Love as Neurochemistry The main system involved in the emotion of love is the pleasure pathway, which consists of dopamine pathways in the mesolimbic system. Studies using functional magnetic resonance imaging (fMRI) have demonstrated increased activity

in the ventral tegmental area (VTA) and the caudate nucleus of individuals when they are shown a photo of someone they love. The caudate nucleus helps maintain the intensity of love by heightening anticipation, motivation,and planning for a particular reward. The more passionately a subject feels towards their lover, the more active their caudate nucleus appears on the fMRI (Fisher, Aron, & Brown, 2005). The dopamine system promotes feelings of pleasure, motivation, and â&#x20AC;&#x2DC;general arousalâ&#x20AC;&#x2122;.

The glutamate neurotransmitter is involved in memory and learning pathways. Along with dopamine, glutamate may also trigger a memory of the loved one in response to environmental cues (Hyman, 2005). The neurotransmitter norepinephrine is associated with sentiments of love, including energy, alertness,

Thalamus Frontal and cingulate Nuc. acc. septum cortex Hypo.

Olfactory bulb

Amyg.

VTA Substantia nigra

Spinal cord

Figure 1 The mesolimbic dopamine system is made up of the ventral tegmental area (VTA) and the substantia nigra, which send dopamine neuron axon projections to various sites, including the nucleus accumbens, prefrontal cortex, and caudate nucleus and putamen (Gardner & Pagani, 2003; Kolb & Whishaw, 2006, p.227).

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Special Interest

10 inability to sleep, and loss of appetite (Fisher, Aron, & Brown, 2006).

Different Types of Love and Changes over Time The triangular theory of love postulates that love has three dimensions: intimacy, passion, and commitment (Ackler et al., 1992). Intimacy is the feeling of connection between lovers, while passion is related to motivational and arousal behaviours, including physical attraction, sexual craving, and romance. Commitment is the premeditated choice to maintain a long term partnership with a mate (Fisher, 2004). These dimensions of love change over time; intimacy and passion decrease while commitment increases (Ackler et al.,1992). Romantic passion typically wanes over time from an obsessional, high energy “kind of sickness” to a calmer, “companionate love”. It is not known for sure how the brain dampens romantic love.

It may produce less dopamine and norepinephrine, or their receptor sites may become desensitized.

Other hormones such as oxytocin may inhibit these chemicals (Fisher, 2004). Oxytocin and vasopressin, produced in the hypothalamus and gonads, are partly responsible for feelings of attachment (Carter, 1998).

For example, in monogamous prairie voles, suppressing vasopressin causes promiscuity while enhancing it increases possessiveness (Wang, Ferris, & De Vries, 1994).

Oxytocin fosters long-term attachment between males and females (Carter, 1998).

There is a complex relationship between the romantic neurotransmitters and the attachment hormones. In certain situations, dopamine and norepinephrine can cause the release of oxytocin and vasopressin (Esch & Stefano, 2005). However, oxytocin can

Issue 15 inhibit dopamine and norepinephrine activity, thus ‘quelling the chemistry of romance’ (Fisher, 2004). Melatonin and arginine-vasotocin, the two major pineal hormones, may inhibit the effects of romantic love and infatuation in the brain by dampening dopamine activity and inhibiting activity in the caudate nucleus (Shoja et al., 2007).

Nature may have programmed our brains to inhibit feelings of romantic passion over time. Romantic love is stressful and involves a large expenditure of energy, and thus would be maladaptive if sustained over long periods (Esch & Stefano, 2005).

Romantic love likely evolved to drive the sexes to seek out and mate with each other and remain faithful long enough

“Love is not a singular emotion but a motivational system causing a range of emotions....” to bear a child. However, In order to raise the child, parents need feelings of attachment rather than intense romantic passion (Fisher, 2004).

Two regions in the brain, the anterior cingulate cortex and the insular cortex, are more active in long-time lovers than in new lovers (Fisher et al., 2005). Emotions, attention, and memory interact in the anterior cingulate region.

It is possible that over time, the brain consolidates and integrates emotional memories and thoughts involving love (Fisher, 2004).

Impact of Age on Love While love changes over time, it does not appear to correlate with age. One survey found that forty-five year-olds

reported the same level of passion for their lovers as subjects under the age of twenty-five (Fisher, 2004).

A cross-generational study of 255 subjects had similar findings (Wang & Nguyen,1995).

“Love Sickness” Love is not a singular emotion but a motivational system causing a range of emotions, not all of which are pleasant (Fisher et al., 2005). Separation anxiety occurs not only in small children but between lovers as well, causing the release of stress hormones such as cortisol and corticosterone (Fisher, 2004). For example, separation of female and male prairie voles increases corticosterone levels.

However, when the partners are reunited, corticosterone levels drop to levels below baseline (Carter, 1998). Love is associated with other negative emotions, such as ‘anxious preoccupied attachment’ (Bartholomew & Horowitz, 1991). This occurs in an individual who is over-involved in the relationship and is dependent on another for his or her emotional well-being.

Love and Addiction There are strong similarities between love and addiction (Dupont, 1998).

Romantic love produces a euphoric high that is characteristic of many illicit drugs. Like addiction, love is associated with craving and obsession. Passion is often very difficult to control and leads to impaired decision-making, similar to the effects of drug addiction (Fisher, 2004).

Love and addiction both share similar neurochemical pathways. Both are associated with the mesolimbic reward and motivation system, which is mediated largely by dopamine (Esch & Stefano, 2005). One study looked at

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However, differences between love and addiction remain (Esch & Stefano, 2005). Natural pleasure producing activities, such as eating or sex, have feedback loops that can inhibit motivational behaviour or even activate aversion.

After eating, it takes time for appetite to return. These mechanisms do not always work for drugs such as cocaine (Esch & Stefano, 2005).

Conclusion The mesolimbic pleasure pathway is the main system believed to control love. This “love pathway” is associated with many different types of neurotransmitters, including dopamine, glutamate, and norepinephrine. The triangular theory of love describes intimacy, passion, commitment, and the different components of love. Love may be a form of subtle addiction.

Addicts and lovers exhibit similar behaviour, and lovers go through two stages related to addiction - withdrawal and relapse. Conversely, some drugs stimulate cravings that do not always cease immediately after taking the drug.

References Ackler, M., College, E., Davis, M. (1992). Intimacy, Passion and Commitment in Adult Romantic Relationships: A Test of the Triangular Theory of Love. Journal of Social and Personal Relationships, 9(1), 21-50.

Bartels, A., & Zeki, S. (2000). The neural basis of romantic love.

Neuroreport, 11(17), 3829-3834.

Bartholomew, K., & Horowitz, L. M. (1991). Attachment styles among young adults: A test of a four-category model. Journal of personality and social psychology, 61(2), 226-244.

Carter, C. S. (1998). Neuroendocrine perspectives on social attachment and love. Psychoneuroendocrinology, 23(8), 779-818.

DuPont, R. L. (1998). Addiction: A new paradigm. Bulletin of the Menninger Clinic, 62(2), 231-242.

Epel, E., Jimenez, S., Brownell, K., Stroud, L., Stoney, C., & Niaura, R. (2004). Are stress eaters at risk for the metabolic syndrome? Annals of the New York Academy of Sciences, 1032, 208-210.

Esch, T., & Stefano, G. B. (2005). The neurobiology of love. Neuro endocrinology letters, 26(3), 175-192.

Fisher, H. E., Aron, A., & Brown, L. L. (2006). Romantic love: A mammalian brain system for mate choice. Philosophical transactions of the Royal Society of London.Series B, Biological sciences, 361(1476), 2173-2186.

Fisher, H., Aron, A., & Brown, L. L. (2005). Romantic love: An fMRI study of a neural mechanism for mate choice. The Journal of comparative neurology, 493(1), 58-62.

Fisher, Helen. (2004). Why We Love: the nature and chemistry of romantic love. New York: Henry Halt and Company.

Gardner A., Pagani M. (2003). A review of SPECT in neuropsychiatric disorders: neurobiological background, methodology, findings and future perspectives. Alasbimn Journal 5 (21), 21-25.

Heckscher W.S. (1938). Was this the face…? Journal of the Warburg Institute 1, (4)295-297.

Henker, B., Whalen, C. K., Jamner, L. D., & Delfino, R. J. (2002). Anxiety, affect, and activity in teenagers: Monitoring daily life with electronic diaries. Journal of the American Academy of Child and Adolescent Psychiatry, 41(6), 660-670.

Hyman, S. E. (2005). Addiction: A disease of learning and memory.

The American Journal of Psychiatry, 162(8), 1414-1422.

Kolb, B.,Whishaw, I. (2006). An Introduction to Brain and Behaviour.

United States: Worth Publishers.

Koob, G. F. (2006). The neurobiology of addiction: A neuroadaptational view relevant for diagnosis. Addiction (Abingdon, England), 101 Suppl 1, 23-30.

Shoja, M. M., Tubbs, R. S., & Ansarin, K. (2007). A cure for infatuation?: The potential ‘therapeutic’ role of pineal gland products such as melatonin and vasotocin in attenuating romantic love. Medical hypotheses, 68(5), 1172-1173.

Wang, Z., Ferris, C. F., & De Vries, G. J. (1994). Role of septal vasopressin innervation in paternal behavior in prairie voles (microtus ochrogaster). Proceedings of the National Academy of Sciences of the United States of America, 91(1), 400-404.

Wang, A. Y., & Nguyen, H. T. (1995). Passionate love and anxiety: A cross-generational study. The Journal of social psychology, 135(4), 459-470.

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Special Interest

fMRI scans of subjects in love compared to subjects who had just taken opioids or cocaine. Many of the same brain regions were active, including the anterior cingulate cortex, the caudate nucleus and putamen, as well as the insular cortex (Bartels & Zeki, 2000).

People in love also exhibit three common stages of addiction: craving, withdrawal and relapse (Fisher, 2004).

For instance, as a relationship intensifies, they usually crave more and more of the “love drug” (Fisher, 2004, p.183). When separated from their lovers for any length of time, they often crave renewal of contact. Upon the termination of a particular relationship, the participants often show signs of withdrawal, such as anxiety, insomnia, fluctuations of appetite, depression, anxiety, and progressive irritability.

The craving may persist long after the relationship has ended, sometimes triggered by environmental cues that are reminders of their lost lover, such as a song or a common acquaintance. These cue-triggered cravings are present in a similar fashion in those created by addictive drugs (Hyman, 2005).

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Issue 15

The Diabetic Pandemic: Globalization, Industrialization, and Type 2 Diabetes Diabetes is an illness that is increasing in incidence worldwide. This paper gives an introduction to the disease, and describes its etiology and epidemiology. Most importantly, it analyzes the possibility of a correlation between a socioeconomic predictor (GDP PPP per capita) and diabetes prevalence in the world.

Neil Dattani and Allan Jiang

I

n the past few decades, the socioeconomic conditions of nations around the world have trended towards parity, and there has been a growth of global interdependencies.

This continuing trend poses various risks to individual nations ranging from political unrest, loss of cultural expression and the increased incidence of certain diseases.

In this article, we examine Type 2 Diabetes, one of this decade’s greatest pandemics (World Diabetes Foundation, 2006). Specifically, we aim to look at the role of socioeconomic predictors of this disease in developing and developed nations.

Type 2 Diabetes What is it?

Type 2 Diabetes is an illness involving the pancreas producing inadequate levels of insulin, or the body’s insufficient response to the insulin that it produces (World Health Organization, 2008). Long term complications may include blindness, heart disease, kidney problems, nerve damage, and erectile dysfunction (Canadian Diabetes Association, 2008). In 2006, the United

Nations officially recognized diabetes as a global health threat (Canadian Diabetes Association, 2008).

Etiology Research is being conducted to better understand the biochemical pathways involved in the development of Type 2 Diabetes. Some studies have shown

“Once considered a disease of affluence, diabetes is now becoming increasingly prevalent in developing countries ” that insulin-receptor substrates (IRS proteins), specifically IRS-2, may be linked with Type 2 Diabetes (Withers et al., 1998). Moreover, some researchers have been using novel experimental techniques with magnetic resonance spectroscopy (MRS) in order to provide insight into molecular defects present in diabetic subjects. Based on this research, it is observed that insulin

resistance observed in diabetics is mainly attributed to reduced activity of insulin-stimulated glucose transport via the GLUT4 protein (Petersen & Shulman, 2006).

Although the exact cause of Type 2 Diabetes is still unknown, healthcare professionals agree that it is the result of both genetic factors and lifestyle. Physical inactivity and obesity are often cited as the main causes, indicating that this disease may be preventable to some extent (Bennett, 1998).

Global Epidimiology Overview While considered a disease of affluence, diabetes is now becoming increasingly prevalent in developing countries (Siegel & Narayan, 2008). Diabetes affects 5.9% of the world’s adult population, and accounts for approximately 5% of all global deaths, showing that it truly is a disease of global proportions (Figure 1). The number of deaths is expected to increase by more than 50% in the next 10 years.

Several interesting trends arise as public health professionals

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and epidemiologists attempt to analyze morbidity data.

For example, 80% of people with diabetes worldwide live in low and middle income countries. While the rate of obesity among these countries is lower than high income countries, it is expected that low and middle income countries will experience the greatest increase in prevalence. This indicates

that there could possibly be a causal relationship between a countryâ&#x20AC;&#x2122;s socioeconomic status and the prevalence of diabetes. Furthermore, the age distribution of sufferers differs greatly: most people with diabetes in low and middle income countries are middle-aged (45-64), unlike high income countries, where most diabetic patients are elderly

Figure 1 World map showing diabetes prevalence as percent of population (colour scale), and absolute morbidity for the years 2000 and 2030 (projected). There are geographical, and socioeconomic trends. (King et al., 1998).

Developing countries Estimated number of people with diabets (millions)

Estimated number of people with diabets (millions)

Developed countries

Age group (years)

Age group (years)

Estimated number of adults with diabetes Figure 2 Developing countries have higher absolute morbidity and faster projected growth rates of absolute morbidity than developed countries. Of significant importance are the differences in age distribution between developing and developed countries (Wild et al., 2004).

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Issue 15

Diabetes Prevalence, 2025 vs. GDP PPP per capita 20

Figure 3 Increase in diabetes prevalence over the years 2000-2025 compared with GDP PPP for the year 2007. Generally, the $10 000 + range corresponds to the GDP PPP of developed countries. Thus, the greatest increase in diabetes prevalence will likely occur among the developing countries at the higher end of the GDP PPP spectrum. These countries are the most rapidly developing undeveloped countries (Central Intelligence Agency, 2008).

18 16

Prevalence (%)

14 12 10 8 6 4 2 0 $0

$10,000

$20,000

$30,000

$40,000

$50,000

$60,000

GDP PPP per capita (2007)

(65+) (World Health Organization, 2008). This acts as further evidence of a possible link between wealth and diabetes (Figure 2). However, it should be noted that this data could simply be a reflection of life expectancy differences among countries.

The possibility of a connection between a countryâ&#x20AC;&#x2122;s socioeconomic status and the risk of Type 2 Diabetes has not been fully understood. In order to examine this possibility, we investigated the effect of gross domestic product at purchasing power parity (GDP PPP) per capita, an indicator of socioeconomic status on diabetes prevalence (Figures 3). Diabetes prevalence estimates from the year 2000 and predictions for the year 2025 were used, in order to see current and future trends (King et al., 1998). GDP PPP per capita data was obtained from the year 2007, as this was the most complete and reliable data set available (Central Intelligence Agency, 2008). To further analyze these trends, we examined the relationship between GDP PPP per capita and the estimated increase in diabetes prevalence from 2000-2025.

Analysis There appears to be a trend of increase in diabetes prevalence by GDP PPP per capita with a pronounced peak around $6000-10 000. While it appears that a relationship exists, the significance of such a relationship is limited, as the comparison is between only the GDP PPP per capita figures. Since this data is used at a national level, it may not

â&#x20AC;&#x153;Developing countries will experience the greatest burden of diabetes over the next two decades... â&#x20AC;? be assumed that all members of these countries will face increased risk of diabetes. Instead, it is more appropriate to look at this potential connection holistically, considering other factors within nations that could explain the increase in diabetes prevalence.

Many behavioural risk factors for Type 2 Diabetes are characteristic of

the lifestyles of industrialized countries.

Thus, developed countries have a high prevalence of this illness. Since Type 2 Diabetes affects an older population and these countries are generally aging, the frequency of the disease will continue to increase.

As developing countries are becoming wealthier and increasingly interdependent on developed countries, diabetes risk factors characteristic of developed countries may be starting to affect developing countries as well.

The availability and marketing of lipidrich and processed foods, time-saving gadgets, occupational reforms and urbanization are likely contributing towards the increase of diabetes prevalence seen in developing countries (Siegel & Narayan, 2008).

Implications of the Diabetes Pandemic The diabetes pandemic is very costly for all countries; direct medical costs are approximately five times higher for diabetics than the general population.

These high costs are causing a great strain on national and individual

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spending in many poorer nations.

Countries afflicted may see a drop in productivity, which will lead to a lower quality of life for its citizens (Siegel & Narayan, 2008).

Conclusion Our analysis shows that there may be a connection between a socioeconomic indicator â&#x20AC;&#x201C; GDP PPP per capita and diabetes prevalence of diabetes. While there is no simple or direct correlation between the two variables, overall

trends indicate that greater increases in diabetes prevalence will occur in rapidly developing countries. These countries will experience the greatest burden of diabetes over the next two decades, as they will be forced to reform healthcare systems to deal with a rapidly changing morbidity profile.

The exposure of diabetes in medical literature and the media has significantly increased in recent times, although several misconceptions still surround the illness. Some believe that it is a completely preventable disease,

while others feel that current treatment methods are adequate and do not support investing into better cures and long-term solutions. Nonetheless, Type 2 Diabetes is a serious, chronic illness which severely affects the quality of life of those who suffer from it. Estimates of increases in diabetes prevalence over the next twenty years are astounding and drastic changes to public health policy are crucial to better manage this pandemic.

References Bennett, P.H. (1998). Etiology and Determinants of Type 2 Diabetes Mellitus. [Powerpoint slides]. Retrieved September 18, 2008 from http://www.pitt.edu/~super1/lecture/lec0461/index.htm Canadian Diabetes Association. (2008). About diabetes. Retrieved September 17, 2008 from http://www.diabetes.ca/aboutdiabetes/what/ Central Intelligence Agency. (2008). The World Factbook. Retrieved September 22, 2008 from https://www.cia.gov/library/ publications/the-world-factbook/index.html King, H, Aubert, R.E., & Herman, W.H. (1998). Global Burden of Diabetes, 1995-2025. Diabetes Care, 21(9), 1414-1431.

Novo Nordisk Care. (2008). Type 2 Diabetes. Retrieved September 15, 2008 from http://www.novonordiskcare.com/type-2-diabetes/ Petersen, K.F., & Shulman, G.I. (2006). Etiology of Insulin Resistance.

The American Journal of Medicine, 119(1), S10-S16.

Siegel, K., & Narayan, K.M.V. (2008). The Unite for Diabetes campaign: Overcoming constraints to find a global policy solution. Global Health, 4(3).

Wild, S., Roglic, G., & Green, A. (2004). Global Prevalence of Diabetes.

Diabetes Care, 27(5), 1047-1053.

Withers, D.J., Gutierrez, J.S., Towery, H., Burks, D., Ren, J.M., Previs, S., et al. (1998). Disruption of IRS-2 causes type 2 diabetes in mice.

Nature, 391(6670), 900-904.

World Diabetes Foundation. (2006). Diabetes facts. Retrieved September 15, 2008 from http://www.worlddiabetesfoundation. org/composite-35.htm World Health Organization. (2008). Diabetes. Retrieved September 15, 2008 from http://www.who.int/diabetes/en/

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Issue 15

Examining the Increasing Prevalence of Hepatocellular Carcinoma in Canada

Dolly Lin

H

With over 550,000 newly diagnosed cases each year, liver cancer or hepatocellular carcinoma ranks among the ten most common malignancies worldwide (WHO, 2008). Its increasing prevalence in Canada has prompted a re-evaluation of the burden of the disease. This article will examine the possible explanations behind liver cancer â&#x20AC;&#x2122;s rising incidence; its epidemiology, etiology, and implications to the Canadian health care system.

epatocellular carcinoma causes approximately 660,000 deaths per annum, and accounts for more than 5% of all cancers (WHO, 2008; Ribes et al., 2004). Underlying causes range widely from genetic diseases, parasites, viral infections, to fatty liver disease caused by a high cholesterol diet (El-serag et al., 2001). Damage to

the liver through cirrhosis may cause acute liver failure. However, many cases progress towards tumour formation before liver failure occurs.

Despite improvements in screening, transplantation and surgical resection the prognosis of hepatocellular carcinoma is poor. While the five year post-operative survival rate

is 60-70% in most developed countries, tumour recurrence occurs in more than half of the patients (Davis et al., 2008; Song et al., 2004). Advanced disease progression at the time of diagnosis also accounts for the low survival rates (Dusheiko et al., 1992; Bosch et al, 2004).

Only 13% of males and 15% of females diagnosed survive five years past their diagnosis.

Liver Cancer Epidimiology and Etiology

Figure 1 Common causative agents of liver cancer are summarized figuratively with their methods of carcinogenesis. Many factors listed above, such as alcohol and HCV, can work together in synergy in promoting liver cancer. HBV: Hepatitis B, NAFLD: Non-Alcoholic Fatty Liver Disease; HCV: Hepatitis C.

Liver cancer is generally considered an uncommon problem in Canada.

Incidence rates, once among the lowest in the world at less than 3.3 per 100,000, have seen an unfortunate increase of 2.5% annually since 1997 (Bosch et al., 2004; Canadian Cancer Statistics 2007).

It now ranks as the 19th most common cancer in the country. Assessment of the relative burden and risk find that while the rates of breast, ovary, and pancreatic cancers are all decreasing, the burden of liver cancer is increasing significantly (Figure 2).

Among the many factors that contribute to liver carcinogenesis worldwide, 80 to 85% of all cases are a result of chronic hepatitis B and C infections (Davis et al., 2008). Due to

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Figure 2 Evaluation of cancer incidence burdens for specific cancers, through the total number of new cases, and cancer risk, through age-standardized incidence rates, shows that liver cancer burden has increased dramatically since 1994 for Canadians.

Liver cancer burden and risk increase is in the top 3 for both male and female Canadians, while the risk of many common cancers such as breast, ovarian, colorectal and pancreatic cancers have decreased since 1994 (National Cancer Institute of Canada, 2007).

their scarcity in Canada, the role of genetic factors and liver parasites will not be addressed in this article. The incidence rates due to non-alcoholic fatty liver disease have not been extensively documented, they will be discussed here due to their relevance in North America (Figure 1).

Cirrhosis is the scarring of the liver due to connective tissue integration in response to heavy damage.

This state of liver damage promotes cancer due to the abnormally high hepatocyte division rates, which increase the risk of mutations in this typically non-mitotic cell population (Anzola, 2004). Most etiologic factors promote carcinogenesis by promoting cirrhosis. Prominent examples are non-alcoholic fatty liver disease, fat accumulation causing liver inflammation and scarring and alcoholic liver disease, in which alcoholic metabolites damage liver tissue (Cai et al., 2005; WHO, 2004). On the other hand, hepatitis B and C induce cirrhosis by triggering inflammation through infection, which further promotes mutations in hepatocytes through viral protein activity (Gurtsevitch, 2008; Benard, Douc-Rasy & Ahomadegbe, 2003). The hepatitis B virus (HBV) directly mutates liver cells through integrating viral DNA into the host and accounts for the most cases of all non-cirrhotic liver cancer (Brechot, 2004).

Causes of Liver Cancer Increase in Canada Hepatitis B HBV is a prime suspect for the increased prevalence of hepatocellular carcinoma. As vaccines for the virus become available, the spread of HBV is most likely attributable to immigration from areas of high viral prevalence. Hepatitis B

infection occurs when individuals are exposed to the virus through bodily fluid transmissions. Infection is characterized by jaundice and flares of abnormal liver activity. While 90% of exposed adults regain normal liver function (Rehermann et al., 2005), HBV infection in children is far more problematic.

This often occurs during delivery or in early infancy through transmission of the motherâ&#x20AC;&#x2122;s bodily fluids. As many as 90% of these individuals develop chronic infection. This develops into cirrhosis and liver cancer (Seeger et al., 2000). From the integration of HBV DNA into host cells, it is becoming evident that even infected individuals who recover normal liver activity are at higher risk for the development of liver cancer (Mulrooney-Cousins & Michalak, 2007).

To assess the effect of immigration, an Australian study modelled the future burden of Hepatocellular Carcinoma (HCC) based on a) the number of immigrants from each HBV endemic country currently settling in Australia, b) the rates of HBV in their native country, and c) the rates of HCC in chronic HBV carriers. The result was a linear rise in projected cancer rates until at least 2025 (Nguyen 2007). Canada receives more Asian immigrants than Australia. Similar, if not greater HCC increases from HBV infection should also be also expected. In fact, immigration in Australia peaked in the early 1990s, while Canadian Asian immigration continues to rise after 2000. Therefore, HBVattributed cancer cases are unlikely to decline in the near future. However, concrete support for this hypothesis is unavailable due to the scarcity of Canadian HBV-related epidemiological statistics, the asymptomatic state of most chronic HBV infections, and varying HBV reporting protocols across the country (Zhang, Zou, & Giulivi, 2001).

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Issue 15

Change in HCV and HBV Prevalence over Time

HCV

HBV

Hepatitis C Like HBV, Hepatitis C (HCV) is transmitted through bodily fluids though transmission from motherto-child is virtually nonexistent.

Transmission among adults results in chronic infection in 60-80% of exposed individuals (Rehermann & Nascimbendi, 2005). The rate of cirrhosis development in chronic HCV carriers is highly variable, with 3-4% of cirrhotic cases leading to cancer (Anzola, 2004; Gurtsevitch, 2008). The average time span between viral infection and cancer development is around 30 years (Tong, El-Farra, Reikes, & Co., 1995).

In the United States, there are an estimated 3.9 million individuals infected with HCV (Razali et al., 2007). A 51% increase in incidence of HCC in the greater Houston area did not correlate with immigration or population aging, but did correlate with HCV infection (Kulkarni, Barcak, El-Serag & Goodgame, 2004). In addition, HCV has been identified as a major risk factor for HCC in Caucasians and African Americans (Di Bisceglie et al., 2004). It is estimated that 50% of the increase in liver cancer observed in the US between 1975 and 1998 is attributable to HCV infection (El-Serag, Davilda, Peterson & McGlynn, 2003). Modelling within Canada in 1998 predicted that HCC prevalence

Figure 3 This chart was automatically generated from data collected by the Public Health Agency of Canada, showing the total number of reported cases of HCV in grey, and the total number of reported cases of HBV in black (Public Health Agency of Canada, 2005).

will increase by 102% by 2008 due to HCV infection alone (Zou, Tepper & El Saadany, 2000). Although HCV infection rates had reached their highest levels to date in Canada in the late 1990s, the number of people living with HCV is still increasing (Figure 3).

Non-Alcoholic Fatty Liver Disease The contribution of Non-Alcoholic Fatty Liver Disease (NAFLD) to hepatocellular carcinoma is not well documented, as this disease has only recently emerged as a health concern. Its association with obesity makes it a pressing topic in North America. Based on the calculated risk of NAFLD in obese individuals, an estimated 20-30% of the adult population living in developed countries has, or will develop, NAFLD. Cirrhosis will occur in 2-3% of these cases (Preiss et al., 2008).

Implications for the Canadian Healthcare System Given the national gastroenterologist shortage, the unique profile of highrisk individuals and the stigma related to the diseases, rising rates of liver cancer has various implications for the Canadian health care system.

The Canadian Association of Gastroenterology has identified

human resource planning as a priority for the past two years. The number of gastroenterologists in Canada stands at 1.83 per 100,000 people, and is one of the lowest specialist-to-populations ratios in the G8 countries (Paterson et al., 2006). This ratio is only expected to drop when one third of all practising gastroenterologists reach retirement age over the next 19 years (Leddin et al, 2008). By 2015, Canadians will have 10% less gastroenterologists than they do now (Wait Time Alliance, 2008). This is very alarming considering the excessive wait times already encountered by referred individuals. Less than 33% of patients referred for probable cancer cases were seen by gastroenterologists within target wait times. Overall, the national median wait time has been extended to over 13 weeks, with 25% of patients waiting more than 29 weeks (Leddin et al., 2008).

Documented as cost-effective, screening and surveillance programs are vital for individuals with high risks of liver cancer, as all viable treatments are limited to targetting non-metastatic tumours at the time of discovery (Dusheiko, Hobbs, Dick & Burroughs, 1992; Bartlett & Heaton, 2008; Kemp, Pianko, Nguyen, Bailey & Roberts, 2005; Bolondi et al., 2001).

Given the specialistâ&#x20AC;&#x2122;s role in issuing

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surveillance exams, the shortage of gastroenterologists does not bode well for the increase in prevalence of liver cancer patients expected in future years.

While HBV infection rate ranges from 0.02 to 0.5% in the Canadian population, infection rates in the immigrant population is as high as 4.3%. Areas of concern for this demographic include documented low levels of HBV awareness and possible language barriers preventing health care access (Cheng, Lee, Teh, Wang & Kwan, 2005).

As for Hepatitis C, the rigorous protocols regarding health care equipment today means that viral transmission occurs mainly through intravenous drug use. Because there is a perception that the disease is self-inflicted, controversy exists over the use of taxation as a form of public financing to provide treatment for the

disease. For example, the existence of InSite is a source of provocation in the public fora; InSite is North Americaâ&#x20AC;&#x2122;s first safe injection site aiming to limit infection disease transmission (The Ottawa Citizen, 2008).

Stigma surrounding the diseases HBV and HCV is also a problem for viral carriers seeking aid. Hepatitis carriers surveyed in the United States reveal that 20% have experienced job discrimination over their viral status, while 13% felt social stigma and alienation from their community (Hepatitis Central, 2007).

Conclusion Increasing liver cancer incidence in Canada reveals a potential public health problem easily overlooked due to its low prevalence in Canada. Several common factors such HBV, HCV, and NAFLD, are projected to continue in

future risk. The projected worsening shortage of gastroenterologists is another concern for increasing liver cancer rates, especially given the established relationship between regular screening and liver cancer survival rates. Research into the main causes of accelerating rates and future incidence projections would be useful in determining whether timely interventions could alleviate future burdens on the Canadian healthcare system.

Acknowledgements Special thanks to Dr. Mel Krajden from the BC Center for Disease Control, Hepatitis Division, for taking the time to answer my questions. Further gratitude is due to the Public Health Agency of Canada for allowing me access to archived data regarding Hepatitis B incidence.

References Anzola, M. (2004). Hepatocellular Carcinoma: role of hepatitis B and hepatitis C viruses proteins in hepatocarcinogenesis. Journal of Viral Hepatitis, 11, p. 383-393.

Bartlett, A. & Heaton, N. (2008). Hepatocellular carcinoma: Defining the place of surgery in an era of organ shortage. World Journal of Gastroenterology, 14, p. 4445-4453.

Benard, J., Douc-Rasy, S., & Ahomadegbe, J-C. (2003). TP53 family members and human cancers. Human Mutation, 21(3), p. 182191.

Bolondi, L., Sofia, S., Siringo, S., Gaiani, S., Casali, A., Zironi, G., et al.

(2001). Surveillance programme of cirrhotic patients for early diagnosis and treatment of hepatocellular carcinoma: a cost effectiveness analysis. Gut, An International Journal of Gatroenterology and Hepatology, 48, p. 251-9.

Bosch, F., Ribes, J., Diaz, M. & Cleries, R. (2004). Primary Liver Cancer: Worldwide Incidence and Trends. Gastroenterology, 127(5), S5S16.

Bouchardy, C., Parkin, D.M. & Khlat, M. (1994). Cancer mortality among Chinese and South-East Asian migrants in France. Int. J. Cancer, 58, p. 638-43.

Brechot, C. (2004). Pathogenesis of hepatitis B virus-related hepatocellular carcinoma: old and new paradigms. Gastroenterology, 127 (5), S56-61.

Cai, D., Yuan, M., Frantz, D. Melendez, P.E., Hansen, L, Lee, J & Shoelson, S.E. (2005). Local and systemic insulin resistance resulting from hepatic activation of IKK-B and NF-kB. Nat. Med. 11, p. 183â&#x20AC;&#x201C;190.

Canadian Cancer Society/National Cancer Institute of Canada.

(2007). Canadian Cancer Statistics 2007. Retrieved August 19, 2008 from http://www.ncic.cancer.ca Cheng, J., Lee, T.K., Teh, C-Z, Wang, C.Y.M., Kwan, W.C.P., & Yoshida, E.M. (2005). Cross-Sectional Study of Hepatitis B Awareness among Chinese and Southeast Asian Canadians in the Vancouver-Richmond community. Canadian Journal of Gastroenterology, 19, p. 245-249.

Cutler, N. (2007, August 27). Breaking the Hepatitis C Social Stigma.

Hepatitis C Information Central. Retrieved September 19 from http://www.hepatitis-central.com/mt/archives/2007/08/breaking_the_he.html.

Davis, G.L., Dempster, J., Meler, J.D., Orr, D.W., Walberg, M.W., Brown, B., et al. (2008). Hepatocellular carcinoma: Management of an increasingly common problem. Proc Bayl Univ Med Cent, 21, p.

266-280.

Di Bisceglie, A. (2004). Issues in screening and surveillance for hepatocellular carcinoma. Gastroenterology, 127 (5), S104-107.

Dusheiko, G.M., Hobbs, K.E.F., Dick R. & Burroughs, A.K. (1992). Treatment of small hepatocellular carcinomas. The Lancet, 340 (8814), p. 285-289.

Esteban, J., Sauleda, S., & Quer, J. (2007). The changing epidemiology of hepatitis C virus infection in Europe. Journal of Hepatology, 48(1), p. 148-162.

Gurtsevitch, V.E. (2008). Human oncogenic viruses: Hepatitis B and hepatitis C viruses and their role in hepatocarcionogenesis. Biochemistry, 73, p. 627-639.

For complete reference list, please visit www.meducator.org

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Issue 15

Editorial We are all Vulnerable: Perspectives on Climate Change and Health

Tyler Law

I

In 2002, ETHsustainability, a founding partner of the Alliance for Global Sustainability (AGS), created the concept for the “Youth Encounter on Sustainability-YES” course, with the aim of developing the leadership capacity necessary for a viable future. In March, 2008, the course was held in Tokyo, Japan, attracting a highly diverse group of students to discuss global challenges and opportunities for sustainable development.

n Tokyo, a group of 40 young people from around the world gather to try to understand and address the mammoth problem of climate change.

The irony of the carbon dioxide expended in air travel is not lost on them. Many study environmental science; I stand out as one of two who are studying health.

For the first few days, we talk about the effects that climate change will have on the world. There is global warming that, by changing average temperatures only a few degrees, will make it difficult for certain species of plant life to grow.

Melting ice caps will cause flooding and destroy fertile land. Animals will be unable to find food, weather conditions will be extreme and unpredictable, and entire species will die out. It is a rather bleak picture. It will happen gradually, but relentlessly and with great difficulty of reversal.

It takes no one by surprise that developing countries will suffer first, and hardest. Many lie near the equator, where global warming will have its most profound effects. Not to mention that many already face a food crisis – how can they cope with further loss of

crops? The misfortunes seem to spiral in on each other. As worldwide energy demand grows, energy prices will soar, forcing countries without sufficient resources out of the market. Loss of food and energy could lead to a severe state of insecurity, and a breakdown of infrastructure – police and emergency medical teams will be heavily restricted.

In developed countries, with well defined infrastructure and response networks, the damage will not immediately be as rapid or critical, but in developing

“Just as human health research is most effective when anticipating problems yet to occur, climate change research will be most effective with solutions designed with an eye for sustainability”

countries, the human cost of a changing climate will be keenly felt.

We turn to solutions, and become passionate in discussion. How can these problems be stopped, before it is too late?

Renewable energy is quickly mentioned, particularly solar and wind- they do not generate emissions, are not limited by quantity, and have a low environmental impact. This can go part way to reducing the energy demand that causes so much carbon dioxide to be released through power generation. A carbon trading system is also an interesting method of reducing emissions. The idea of using a market-based solution to protect the environment is a somewhat strange reversal. And of course, engineering solutions seem the most promising – be they hybrid cars, high yield crops, or hydrogen fuel cells. With these, the future offers a glimmer of hope; we can shrink our environmental footprint, perhaps with little loss of personal convenience.

But something is wrong with this language, and I note carefully the use of ‘part way’, ‘reduce’, and ‘shrink’. The words are chosen carefully to avoid the use of absolutes, and stop simply at mitigation

April 2009

“This is exactly the problem....climate change is not seen as an issue of human health ” devastating economic consequences?

Can advancing technologies really shrink our environmental impact enough to accommodate the breakneck pace of development? It strikes me that these solutions may help, but their practical limitations seem rather short sighted.

In health research, this is less often the case, where a farsighted perspective is strongly valued. We do not simply search for better heart attack medications, but counsel dietary changes as well. While millions are poured into HIV vaccine research, money is also spent encouraging condom use and abstinence. The emphasis on vaccination of infectious diseases like malaria, and not simply on treatment, is a testament to the value of farsighted thinking in health research. In short, health interventions are highly valued (and highly effective) if they promote persistent lifestyle changes. This is exactly the difference between health research and climate research – and exactly the problem.

Climate change is not seen as an issue of human health.

Three changes are needed. The first is a shift in perspective, to more closely realize the effects of climate change on human health. Altering perspective to view climate change not

just as an environmental issue, but as one of the fundamental health challenges today, will bring the resources of the health research world to bear on this pressing problem. Our discussions in Japan were fixed around the impact of humans on the environment, and I was amazed that the impact of the environment on human life was so lightly touched upon. Sustainability is a buzzword in environmental circles, but not often linked to health. Climate change needs to be framed to reflect the magnitude of the human cost that will be seen worldwide.

The second change requires focusing research efforts on solutions that have effects far into the future – solutions that not only mitigate the problem, but address the root causes as well. Just as human health research is most effective when anticipating problems yet to occur, climate change research will be most effective with solutions designed with an eye for sustainability. Framed as a health problem, climate change solutions need not be so concerned with preserving our current style of life. It is necessary to admit to ourselves that strong, perhaps radical changes are necessary; a reorganization

of priorities we should not be afraid of.

The solutions we find easily palatable are simply insufficient. Just as a diabetic does not have the luxury of monitoring their blood glucose only on some days, neither can we maintain a sustainable society without some permanent lifestyle changes.

Third, research must lead to the implementation of evidence-based policies. As environmental issues have been recently capturing greater public attention, no political party can be without some ‘green’ platform elements.

Yet these platforms, and the debates about them, are often not framed using health or environmentally-relevant arguments. The question should not be “which of the environmental platforms is most economically acceptable?”, but “which environmental platform makes the most environmental sense?” – the economic argument is subordinate to the priority of evidence. For these policies to be effective, they must first be empowered by evidence, and not judged by arguments from other domains. We can help, as citizens and constituents, by questioning parties on the evidence behind their platforms, emphasizing

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Editorial

of the problem. Can solar panels and wind farms really provide enough power to pry us from our dependence on fossil fuels? Can a carbon trading system effectively operate when meaningful environmental impact could have

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Issue 15

the language of science for what are fundamentally scientific questions.

Being more immediately at risk, developing countries have a vested interest in climate research as a means of protecting the health of their population. The biggest challenge to climate research in developing countries is, unsurprisingly, resources. However, by framing climate change as a health problem, these countries can bring to bear a whole different set of governmental machinery, and garner support from academic and research institutions both nationally and worldwide. In health research, there is often a gap between what is known and what is acted upon – for climate research, this gap is even larger. Researchers should focus on how to effectively communicate information to those in government. Framing climate change as a health issue will make policymakers’ ears more receptive to the credible climate research already extant. A question we asked repeatedly in Tokyo was, ‘When is it too late?’ It is probable that some effects cannot now

be avoided. Researchers, with the ear of policymakers, should invest in public health projects that lessen the health consequences of climate change – such as response strategies to extreme weather conditions, programs to ensure equitable access to underserviced areas in times of crisis, even methods to control population sizes in areas with limited resources.

The threats of climate change do not discriminate based on income, and developed countries also have an interest in addressing environmental problems. In fact, they have a responsibility to lead the way in taking action on climate change, given that it is the products of their societies that contribute the majority of the problem.

Those of us in Tokyo from developed countries were sharply aware of this responsibility, especially in the company of colleagues from developing countries, but this responsibility fails to register on a national scale. Climate change requires long term solutions, but impoverished citizens of developing countries often

have more immediate health concerns.

It is imperative that countries with adequate research resources allocate them wisely.

While in Japan, I noticed that the group had a tendency to falter over solutions they felt would not be accepted by society. This kind of thinking plagues environmental research. We should determine what needs to be done, and then find ways to do it. We should not determine what we are willing to do, and then rest content. Researchers should stop being so careful to preserve the convenience of modern life. They should not be so concerned with how to make cars emit less pollution, but with how to have fewer people drive cars. It is not necessarily a question of how to create higher yield crops, but how to distribute food more equitably. These are indeed difficult research proposals, but they should not be shied from. Only this kind of radical, farsighted solution will address the root causes of health threats we could soon face.

When it comes to climate change, countries would do well to remember that all populations are vulnerable.

Whether it is a cyclone in Myanmar, a hurricane in New Orleans, or a tsunami in Indonesia, the effects of climate change are evident. Even after two weeks of discussion in Japan, I wondered if it would be enough to spur change in me as an individual, because it is too easy to lose that sense of responsibility. Yet when seeing tragedy on television or disasters in the news, one wishes one could help.

But we can – if we acknowledge the connection between our changing climate and human health. And we have to – if we wish to preserve our health in the future.

April 2009

23

Have you read all the articles? Test yourself and see how well you understood the articles by answering the questions below.

1. Which statement best describes the relationship between GDP PPP per capita and diabetes prevalance? a) There is a clear correlation between the two variables b) There is no correlation whatsoever between the two variables c) A trend, but not a clear one, of increase in diabetes prevalence and GDP pe capita exists d) The significance of such a relationship is limited e) Both C and D 2. The Primary suspect causing increased incidence of hepatocellular carcinoma is: a) Hepatitis B b) Hepatitis C c) Non-alcoholic Fatty Liver Disease d) A and B 3. In his article, Tyler Law argues that: a) Climate change is not seen as an issue of human health b) Climate change directly affects human health c) Human health is jeopardized by global warming d) Solutions to climate change aimed at sustainability will be most effective. e) A and D

MedQuiz

MedQuiz

4. Postpartum depression (PPD) can be associated with which of the following factors: a) Lower socioeconomic status b) Physical stress experienced during childbirth c) Neurotransmitters implicated mood regulation being altered by poor sleep patterns d) A and C 5. The method devised by Hospital for Sick Children researchers to eradicate unpleasant memories involves: a) Neurons in the caudate nucleus b) In vivo human brain cells c.) CREB memory protein d) The diptheria toxin e) c) and d)

5. Which two regionsof the brain have been found to be more active in long-time lovers than in new lovers? a) The anteriorcingulate cortex and the insular cortex b) The substantia nigra and the nucleusaccumbens c) The prefrontal cortex, and caudate nucleus d) Putamen and the insular cortex e) The substantia nigra andthe anterior cingulate cortex

Answers: d, b, e, d, e, a

Meducator Staff

Cancer with Viruses?

McMaster’s Medical Research and Health Ethics

Student Journal

IN THIS ISSUE Also in this issue:

A Journey through Doctor’s right to refuse the Labyrinths of Love patient treatment

We Are All Vulnerable: Perspectives on Climate Chaperones and Change and Health protein folding Examining the Increasing Loneliness and Prevalence of Hepatocellular Carcinoma in Canada cardiovascular

disease

The Diabetic Pandemic: Globalization, Industrialization, Debate on and Type 2 Diabetes Canada’s health care

Global Perspectives:

From Liver to Lover Issue 15 | April 2009

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Back Row (Left to Right): Andrew Yuen, Stephanie Low, Keon Maleki, Randall Lau, Avinash Ramsaroop, Ahmad Al-Khatib Third Row: Veronica Chan, Ran Ran, Hiten Naik, Manan Shah, Randal DeSouza, Simone Liang, Alyssa Cantarutti Second Row: Sangeeta Sutradhar, Navpreet Rana, Fanyu Yang, Siddhi Mathur Front Row: Jacqueline Ho, Crystal Chung

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