Year: 2006

Despite public health efforts, sexually transmitted infection (STI) rates among young people are high and rising, with some groups of youth disproportionately affected. In particular, STI’s are a growing concern for youth living in northeastern BC’s oil, gas, and mining communities. These communities are experiencing rapid growth and social change, largely associated with an influx of young people attracted by the current economic ‘boom’ in the oil, gas and mining industries. Shira Goldenberg is investigating young people’s experiences accessing STI testing and treatment services in Fort St. John, British Columbia. She is examining how socio-cultural factors, such as social norms, gender, ethnicity, religion and structural forces, such as geography, economic restructuring, and public health service delivery mechanisms, affect young people’s experiences with STI testing and treatment. Shira will use this information to recommend ways public health planners can tailor STI interventions to improve the sexual health of youth in northeastern BC and other remote, resource-based communities.

The bacterium Pseudomonas aeruginosa is a major cause of hospital-acquired infections and chronic cystic fibrosis lung infections. This pathogen is difficult to treat because it has the ability to sense and appropriately respond to changing environmental conditions. For example, it can sense and respond to the presence of antibiotics by becoming resistant, making the eradication of established infections extremely difficult. P. aeruginosa infections in cystic fibrosis patients are almost always deadly. An underlying mechanism for antibiotic resistance involves two-component regulatory systems – containing a sensor kinase and a response regulator – that enable bacteria to sense and respond to environmental signals. Two of these regulatory systems within P. aeruginosa have previously been shown to be involved in antibiotic resistance. Jamie Gooderham is determining whether other closely-related P. aeruginosa two-component regulatory systems are also involved in virulence and antibiotic resistance. To do so, he is generating bacteria defective in these systems and studying their virulence, gene expression, and responsiveness to antibiotics. These studies will increase understanding of how this pathogen adapts to environmental signals to develop antibiotic resistance. Ultimately, this will lead to more effective P. aeruginosa therapies, improving treatment outcomes for infected patients.

There is evidence to suggest that healthy men and women experience respiratory system limitations during exercise, such as respiratory muscle fatigue, a limited ability to exhale, and an abnormal exchange of oxygen and carbon dioxide in the lungs. Young active women may be particularly susceptible to these limitations due to their inherently smaller lungs and airways compared to men of equal stature. Unfortunately, there have been few studies aimed at understanding how the female respiratory system responds during exercise. Since healthy young women are predisposed to these limitations during exercise, then healthy elderly women may be particularly vulnerable due to the decline in lung function that occurs as a result of the normal aging process. This decline occurs because of a reduction in “elastic recoil,” which is the ability of the lungs to stretch and inflate. Jordan Guenette is studying the relationships between the respiratory system, exercise, gender, and healthy aging. His goal is to identify the respiratory limitations women face as they age. This information could be used to design exercise rehabilitation programs tailored to meet the needs of different patient populations.

Chemotherapy and radiotherapy are currently used to treat many types of cancer. However, these treatments are not ideal because they target all dividing cells, including both cancerous and healthy cells. Blood cells, for example, have a finite lifespan and new cells are continuously being generated in the bone marrow. Unfortunately, the high doses of chemotherapy or radiation necessary to destroy malignant cells also kill these bone marrow cells. This reduces the body’s ability to replenish healthy blood cells, leading to life-threatening side effects such as anemia, infections, and uncontrolled bleeding. In such cases, the chemotherapy or radiation dose must be reduced, which, in turn, reduces the likelihood that cancerous cells will be eradicated. Melisa Hamilton is studying ways to protect blood cells during cancer treatment, with a particular interest in understanding how the SHIP protein inhibits blood cell survival. Melisa wants to determine whether reducing the level of this protein can increase cell survival during treatment. This would enable patients to withstand higher doses of chemotherapy or radiation with fewer side effects and increase the likelihood of killing the cancer cells.

Canadians, like other people living at higher latitudes, often experience seasonal changes in sleeping patterns, appetite, mood, and energy levels between the winter and summer seasons, but there has been little research to explain why. Fern Jaspers-Fayer is studying the impact of season on thoughts, moods and behaviour. These changes occur along a continuum from normal to abnormal, with severe winter depression, or Seasonal Affective Disorder (SAD), at one extreme. Fern is identifying the changes in electrical brain activity associated with SAD, and will determine whether these changes disappear in the summer. The results should help explain the brain mechanisms involved in SAD, leading to better therapies for the condition and better ways for everyone to chase away the winter blues.

Genetic inheritance in an offspring primarily results from the interplay of dominant and recessive genes between two parents. With certain genes, however, gene expression is parent-of-origin-specific: these genes will always be expressed from either the maternal or paternal chromosome. This process is known as genomic imprinting, which creates a mark, or “imprint”, on the chromosome. Loss of imprinting (LOI) is often studied in the context of disease, especially in cancers, but it is also a normal part of development. For example, in germ cells, imprints are erased and re-set early in development every generation, resulting in a normal period of LOI. Meaghan Jones is investigating a hypothesis that non-germ cells may also experience some normal LOI during development. She will examine the timing, stimulus and duration of LOI in germ cells and somatic cells during development. By determining the various causes of LOI in both types of tissues, she hopes to uncover factors regulating normal LOI and help alleviate the risk of imprinting defects.

Breast cancer is the most common cancer among Canadian women. One in nine women is expected to develop breast cancer in her lifetime, and one in 27 will die of the disease. Metastasis, or the spread of the tumour to another site, is the major cause of death. Notch receptors are cellular proteins required for normal growth and development. However an overproduction of an active component of Notch can cause abnormal cell growth, leading to tumour formation and the spread of cancer to distant sites. Iva Kulic is examining how another protein, called Slug, functions with Notch to promote breast cancer. Both Notch and Slug are found at high levels in some human breast cancers and are a sign of poor outcome. Slug prevents tumour cells from dying and allows them to detach from neighbouring cells and travel to other sites within the body – two key features in tumour development and metastasis. This research will explore whether reducing or eliminating the Slug protein will inhibit breast tumour growth and block the spread of cancer cells. Resolving whether Slug is essential in Notch-induced breast cancer could lead to new ways of preventing and treating the disease.

Persons with a dementing illness such as Alzheimer disease are often cared for at home by family members. Caring for someone with Alzheimer disease can be a stressful and challenging experience. Death anxiety (the fear of death or the dying process) is one issue that has received little attention in research on family caregivers of persons with dementia. As a person with Alzheimer disease may die within years of receiving this diagnosis, a family member may experience death anxiety through fear of watching the person they care for die, or fear of dying while the person with dementia still needs their support. Anthony Kupferschmidt is seeking to understand the degree to which family caregivers of persons with dementia experience feelings of death anxiety and the effect of these fears on their health and ability to cope and continue in their caregiving role. Findings from this research could ultimately contribute to improvements in education and other community-level programs to better support caregivers of persons with a terminal diagnosis. Anthony is also the 2006 recipient of the Canadian Association on Gerentology Margery Boyce Bursary. This award supports post-baccalaureate students who have made a significant contribution to their community through volunteer activities with or on behalf of seniors and who are registered in a program of study focused on aging or the aged. This prestigious award is the only national award available to gerontology graduate students that is not granted on the basis of financial need.

Stroke is a major cause of death and disability in North America. Major efforts have been placed into blocking mechanisms of excitotoxicity following stroke. Immediately after the onset of stroke, a plethora of glutamate is released in the affected area, and activation of NMDA-receptor by glutamate has been attributed to be the main cause of neuronal damage during stroke. Nevertheless, clinical studies of stroke patients given NMDA-receptor blockers have proven to be disappointing. It has been suggested that NMDA-receptor blockers are efficacious only when given prior and/or soon after stroke onset. Once the receptors and downstream death signaling cascades are activated, blocking NMDA-receptor is no longer useful. Since stroke patients often reach the hospital and receive their diagnosis several hours after stroke onset, the conventional therapeutic strategy of blocking NMDA-mediated cell death is not clinically useful. Surprisingly, our preliminary study suggested that only the NR2B subunit-containing NMDA-receptors (NR2BR) promote cell death, and paradoxically, the NR2A subunit-containing NMDA-receptors promote cell survival (NR2AR). We propose that selective activation of NR2AR-dependent cell survival may be a more effective stroke treatment strategy than blocking NR2BR-dependent cell death. In addition, because we are proposing to promote cell survival and not blocking cell death, our treatment should be effective even when administered along time after stroke onset.

Bacteria are the most abundant type of life on earth and are constantly adapting to survive in different environments. The species we see today are highly diverse, reflecting adaptations to massive environmental changes over billions of years. Some adaptations are of significant medical concern because they result in new strains of disease-causing bacteria, greater virulence in existing bacteria, and increased resistance to antibiotics and other drugs that kill or suppress bacteria. These bacterial adaptations are associated with “genomic islands,” clusters of genes the bacteria appear to have acquired from other bacteria, viruses and organisms. The genes of hundreds of disease-causing and non-infectious bacteria have been identified. Morgan Langille is using this information to develop a database of bacterial genomic islands. He aims to identify the origins of bacterial genomic islands and their role in causing disease. This information may enable scientists to better understand and develop new drugs that target infectious disease-causing bacteria.