Understanding social competence in Autism Spectrum Disorders: The development of a standardized measure

Autism and its related disorders are commonly described as lying along a continuum that ranges from mild to severe. As a whole, these disorders are often referred to as Autism Spectrum Disorders (ASD). ASD describes individuals who have three main areas of difficulty: communication and language; social interactions; and restricted or repetitive behaviours/interests. Although social difficulties represent the primary problem for higher functioning youth with ASD, there is a lack of standardized measures to assess the nature and severity of their social impairment. In British Columbia, it is particularly important that clinicians have access to standardized and psychometrically sound tools because ASD diagnoses are tied to publicly-funded services. Jodi Yager is developing and validating a measure of social competence that will be appropriate for use with higher functioning individuals with ASD. She anticipates this tool will ultimately be useful to mental health professionals in both clinical practice and research. Jodi’s standardized measure may play a role in assisting with important assessment and diagnostic procedures and in evaluating the effectiveness of interventions and programs (e.g. social skills training). In addition, by providing a detailed assessment of social strengths and weaknesses, this measure could prove helpful in treatment planning, such as recommending services and interventions that are specifically tailored to meet an individual’s needs. By improving our understanding and measurement of social functioning in youth with ASD, Jodi’s research will contribute to improving developmental outcomes and quality of life in this population.

Novel redox-elimination mechanism of enzymatic glycoside hydrolysis: A detailed study of Family 4 glycosidases

Carbohydrates are found in every facet of life, not only in metabolic pathways, but also as key mediators in intercellular communication and cellular activity. Associated with these important biomolecules are a class of enzymes—glycosidases—that contribute to the breakdown of carbohydrates, allowing for their use as an energy source by the cell. Interruption of these processes can affect cell growth by limiting the supply of available nutrients. With more than 90 different known glycosidase families, the recently-discovered Family 4 glycosidases have been shown to operate through a different mechanism. In addition, this family exists in a number of bacteria, but not in mammals. Continuing in research that was previously funded by MSFHR, Vivian Yip is performing a detailed investigation of the mechanisms of Family 4 glycosidases. Ultimately, she is interested in exploring how inhibition of these glycosidases could be used to develop antibiotics that selectively compromise bacteria, but not the host.

Mining the genome and transcriptome of lung cancer for clinically relevant molecular signatures

Lung cancer is responsible for the greatest number of cancer deaths in Canada. Current chemotherapy treatments are largely palliative, and only a small percentage of patients show a favourable response. Like other cancers, the progression of lung tumours is driven by a series of genetic alterations that can vary significantly between patients. The specific set of changes that occur in any individual tumour influences not only its aggressiveness and outcome, but also the effectiveness of cancer treatment. Scott Zuyderduyn will determine the genetic changes in several hundred lung tumour samples for which treatment and outcome is known. He will then employ computational and statistical approaches to determine which changes can accurately predict how a tumour will respond to different treatments. This research has important implications for determining, at diagnosis, the best choice of cancer-fighting treatment.

Coping with Rheumatoid Arthritis: The Effect of Psychosocial Factors on Chronic Pain

Rheumatoid arthritis (RA) is an incurable disease that affects approximately 1 per cent of the western population. It is associated with a variety of symptoms including chronic pain, stiffness and inflammation of joints, fatigue, and frequent mood changes. Because there is no cure, treatment focuses on alleviating symptoms and maintaining mobility and function. Disease factors only partially predict pain and disability among RA patients; consequently, there is growing interest in the influence of psychological and social factors on the progression of this disease. Amy Zwicker is examining the role and degree to which social support from friends and family, and effective coping strategies may help to decrease pain and increase functional ability in people living with RA. She is also examining the effects of these psychosocial factors on mood and physical well-being of patients and their spouses. Findings from her research may contribute to the development psychologically-based interventions that help RA patients deal more effectively with the pain and disability associated with the disease.

Mechanisms of target-dependent neuronal differentiation in Drosophila

Normal nervous system function requires the generation of an enormous diversity of neurons during development. Differences in the identity and function of neurons depend upon differences in the repertoire of genes that the neuron expresses. Differential expression of these genes is controlled by intrinsic factors—the complement of transcription factors that exist within the neurons— and by extrinsic factors, signals secreted by other cells. Alterations in either of these factors have been implicated in many developmental, psychiatric and degenerative diseases. Dr. Douglas Allan is investigating how these intrinsic and extrinsic signals interact in neurons to selectively turn on the expression of different repertoires of genes in different neurons, so that the neurons attain their appropriate form and function. He is using the fruit fly, Drosophila melanogaster, as a model organism to study these mechanisms, because of the battery of powerful molecular genetic experimental tools available in this organism. Since the basic mechanisms of neuronal development are shared by fruit flies and humans, his work is relevant to understanding how human neurons develop and how disruption of these signals can cause disease.

Examination of the role of cadherin/beta-catenin adhesion complexes in the development and maintenance of synaptic junctions

Synapses of the central nervous system—junctions across which a nerve impulse passes from neuron to neuron—are highly-specialized regions of cell-to-cell contact. Deficiencies in synaptic function are central in many psychiatric and neurodegenerative diseases such as schizophrenia, Alzheimer’s, Parkinson’s and Huntington’s disease. Cell adhesion molecules, localized at synapses, are believed to have an important role in the regulation of synapse formation, maintenance and function. Dr. Shernaz Bamji has previously shown that cadherin and beta-catenin adhesion complexes act to recruit and tether synaptic vesicles to presynaptic compartments, and that transient disruptions of these adhesion complexes are important for the sprouting of new synapses. She is now further investigating the cellular and molecular mechanisms by which synaptic cell adhesion molecules regulate the formation, stability, and elimination of CNS synapses. . Understanding the underpinnings of these mechanisms may lead to the identification of new targets for therapeutic intervention in psychiatric and neurodegenerative diseases.

Structural and functional characterization of the vibrio cholerae toxin-coregulated pilus

Vibrio cholerae is a bacteria that infects the human small intestine to cause the potentially fatal diarrheal disease cholera. This disease, which is spread through contaminated drinking water, represents a major health threat in developing countries, with young children being most vulnerable. The toxin co-regulated pili (TCP) on the surface of V. cholerae are important components in the bacteria’s ability to cause disease in the host. TCP are hairlike filaments that hold the bacteria together in aggregates or microcolonies, protecting them from the host immune response and concentrating the toxin they secrete. The TCP are also the route through which the V. cholerae bacteria is itself infected by a virus called CTX-phi, which enables V. cholerae to produce cholera toxin. Dr. Lisa Craig is determining the molecular structure of the TCP and delineating the regions of this filament that are involved in microcolony formation and in binding to CTX-phi. The information obtained from her studies may lead to vaccines, therapeutics and diagnostics for combating this deadly disease.

Neuromechanical determinants of the metabolic cost of healthy and pathological gait

Walking is a vital means of mobility for most people. While walking is easy for healthy people, for individuals who have suffered a stroke and have partial paralysis of one side of their body (hemiparesis), walking can be difficult. Often, these people will avoid walking, because their gait requires nearly twice the metabolic energy of healthy gait. These increased energy demands may partially explain why stroke patients tend to walk slowly and avoid carrying heavy loads, impairing their daily activities. Dr. Max Donelan’s research aims to advance our understanding of the fundamental principles that underlie locomotion physiology and to apply these principles to directly improve human health. Across the range of his research, he uses a combination of mathematical modeling and empirical experimentation, which involves techniques from biomechanics, energetics and neurophysiology. To study the metabolic cost of gait after stroke, Dr. Donelan is determining the important mechanisms that make normal walking easy and energy-efficient, and how these mechanisms are compromised in individuals with stroke-related paralysis. The results of his research will guide the design of rehabilitation strategies and devices aimed at lowering metabolic cost and increasing patient mobility.

Molecular basis of tenascin elasticity and mechanotransduction

Tenascin is an important family of proteins found in the extracellular matrix of tissues—the filamentous structure that is attached to the outer cell surface and provides anchorage, traction, and positional recognition to the cell, and plays important roles in regulating the interactions between cells and the extracellular matrix. It is also known that tenascin mutations are linked to disorders that affect the mechanical properties of skin tissues and joints. However, little is known about the mechanical properties of tenascins and how they are regulated to adapt tissues to withstand force. To study tenascin, Dr. Hongbin Li is stretching single molecules of the protein and examining its mechanical response. He will also evaluate the consequences of disease-causing mutations on the mechanical behaviour of tenascins. These studies will provide new insight into the molecular basis of tenascin mechanics, and help to pinpoint the cause of tenascin-related connective disorders. They may also offer useful information in developing tissue engineering strategies for skeletal repair.