Medical Sciences Commons^™

Phylogenetic Estimates Of Hiv-1 Gp120 Indel Rates Across The Group M Subtypes, John Palmer, Art Poon

Western Research Forum

Insertions and deletions (indels) in the HIV-1 envelope glycoprotein gp120 play a significant role in the evolution of HIV pathogenesis and transmission fitness. While substitution rates in HIV-1 are well characterized by phylogenetic models, there is a lack of quantitative measures of indel rates in HIV-1. Here we use a dated-tip phylogenetic analysis of gp120 sequences to estimate indel rates for 7 subtypes and CRFs of HIV-1 group M.

We obtained and processed 26,359 HIV-1 gp120 sequences from the Los Alamos National Laboratory HIV Sequence database. After filtering these sequences, we extracted the conserved and variable regions from the remaining …

Mouse Performance On A Novel Touchscreen Continuous Performance Task Is Dependent On Signaling In The Prelimbic Cortex, Tyler D. Dexter, Daniel Palmer, Amy C. Reichelt, Anita Taksokhan, Lisa M. Saksida, Tim J. Bussey

Western Research Forum

Attention is the cognitive processing that facilitates the ability to target and attend to relevant environmental stimuli, while filtering out irrelevant or distracting stimuli. Control over selective attention is theorized to be dependent on organized neural communication that stems from the medial prefrontal cortex (mPFC). To evaluate selective and sustained attention, mice were trained on the novel touchscreen rodent continuous performance task (rCPT), a task designed to emulate the human CPT. In the rodent version, images are continuously presented on a touchscreen, where mice have been trained to selectively respond to one image type while suppressing responses to all others. …

Cell-Free Dna Release During Programmed Cell Death In Ischemia Reperfusion Injury, Alexander Dionne, Anthony M. Jevnikar, Zhu-Xu Zhang

Western Research Forum

Transplantation is invariably associated with acute allograft injury caused by ischemia reperfusion injury (IRI). This injury causes cells of the allograft to undergo various forms of programmed cell death including apoptosis and necroptosis. During programmed cell death, immunogenic molecules are released from cells, one of which is cell-free DNA (cfDNA). We hypothesize that cfDNA is released by microvascular endothelial cells (MVECs) during programmed cell death of IRI and that cfDNA acts as both a biomarker for cellular injury as well as a biologically active molecule capable of amplifying inflammation and organ injury.

Our results indicate that cfDNA is released by …

Exercise To Combat Neurocognitive Decline In Older Adults, Joyla Furlano

Western Research Forum

Background: Older adults with type 2 diabetes (T2D) experience cognitive decline and neural atrophy, and therefore are at high risk for developing dementia. Consequently, older adults at-risk for developing T2D (i.e., overweight or pre-diabetic individuals) are at higher risk for cognitive decline, and intervening at this point may prevent or delay the onset of such decline. One promising lifestyle intervention that may improve neurocognitive function is exercise. For example, 6 months of aerobic training improves cognitive function in overweight or pre-diabetic older adults, but research has not examined whether resistance training (RT) can produce comparable results in this population.

Hypothesis: …

The Effect Of Sepsis On Cerebral Microvascular Blood Flow, Laura Mawdsley, Mamadou Diop, Chris G. Ellis

Western Research Forum

Background: Sepsis is a dysregulated host response to infection that affects 18 000 000 people worldwide, and over 325 000 000 dollars are spent treating sepsis in Canada every year. One of the symptoms of severe sepsis is an altered mental state, which is accompanied with a measured decrease in oxygen levels in the skeletal muscle microvasculature. It is hypothesized that his altered mental state is due to a lack of oxygenated blood reaching the brain.

Hypothesis: After the onset of sepsis, microvascular cerebral blood flow and oxygen levels in the blood will decrease. Onset of decreased blood flow in …

Head Injury Risk And Car Seat Use For Children In Collisions, Peyton A. Schroeder, M.J. Skhurm, D. Fraser, K. Mcclafferty

Western Research Forum

Background: Motor vehicle collisions (MVCs) are the leading cause of death for people under the age of 17 years. Almost 80% of rear seat motor vehicle passengers are children. Previous studies have shown that a large fraction of injuries to children in MVCs involved the head and chest. In this study, the hypothesis that children under the age of eight using a forward-facing child restraint system (FFCRS) will have more severe head injuries than children using any other type of restraints in an MVC was tested.

Methods: Several datasets obtained from Transport Canada and Level 1 Pediatric Trauma Centre emergency …

Investigating Ampk Signalling Regulation Of Autophagy In A Model Of Ovarian Tumour Dormancy, Jeremi Laski

Western Research Forum

Investigating AMPK signalling regulation of autophagy in a model of ovarian tumour dormancy

Jeremi Laski and Trevor G. Shepherd

Background:

Ovarian cancer is the most deadly gynecologic malignancy in women. A particular subset of this disease, epithelial ovarian cancer (EOC), is responsible for over 70% of all diagnosed ovarian cancer cases, yet the mechanisms governing disease progression are poorly understood. One of the unique hallmarks of EOC metastasis lies in the process of spheroid formation, whereby tumour cells aggregate into larger 3D structures. These EOC spheroids have been shown to be metabolically dormant, while concurrently up-regulating autophagy (cellular waste …

Developing Novel Therapeutics For Bacterial Lung Infections, Brandon J. Baer, Ruud Veldhuizen, Cory Yamashita

Western Research Forum

Background: Bacterial lung infections are leading causes of death worldwide. Unfortunately, increasing resistance to antibiotics and the inflammation often accompanying these infections are leading to poor outcomes despite antibiotic intervention. Complicating treatment further, the tree-like branching structure of the lung makes drug delivery to distal sites of infection difficult. Our research aims to address these challenges by developing new therapeutics and new tools to improve and assess drug delivery, bacterial killing and inflammation. Our therapy combines host defense peptides, which have been shown to kill antibiotic-resistant bacteria and down regulate inflammation, with a pulmonary vehicle, exogenous surfactant, that can improve …

Differentiating Midbrain Structures In Parkinson’S Disease Using Magnetic Resonance Imaging, Erind Alushaj

Western Research Forum

Background: This study aims to differentiate two midbrain structures: substantia nigra pars compacta (SNc) and ventral tegmental area (VTA) in patients with early-stage Parkinson’s Disease (PD) using magnetic resonance imaging (MRI). The SNc degenerates earlier in PD causing motor symptoms; whereas, VTA degeneration occurs later leading to non-motor symptoms. Conventionally, the SNc and VTA project to the dorsal and ventral striatum respectively. Evidence suggests this model may be overly simplistic since the dorsal striatum has uneven dopamine loss in PD. So, the dorsal striatum was segmented into six functional subregions and only the caudal motor subregion showed early changes …

Clarifying Dopaminergic Projections Of The Ventral Tegmental Area And Substantia Nigra In Humans Using Structural Magnetic Resonance Imaging, Nicholas Handfield-Jones

Western Research Forum

Background

Dopaminergic (DA) pathways from the human midbrain to the striatum mediate movement, decision making, learning, and reward processing. Classically, the scientific consensus has been that there are two main DA pathways: the nigrostriatal and the mesolimbic pathways. In the nigrostriatal pathway, the substantia nigra par compacta (SNc) sends DA to the dorsal striatum (DS), and in the mesolimbic pathway, the ventral tegmental area (VTA) sends DA to the ventral striatum (VS) as well as prefrontal and limbic cortices. Recent findings, however, cast doubt on the accuracy of this model. It seems likely these DA projections are more overlapping and …

P33. Design And Evaluation Of An Escherichia Coli Biomarker For Indication Of Ph, Kevin X. Zhou, Luana Langlois, Ashmita Singh, John Prince

Western Research Forum

Measuring pH is one of the most commonly used techniques in both the laboratory as well as the field due to its importance in a multitude of biochemical processes. Traditional methods of measuring pH may be highly developed in accuracy and precision but often involve disruption of the environment. Biological markers offer an alternative that allows for long-term pH monitoring. This innovative approach allows for vast applications such as in the manufacturing, food processing and research industries. Under moderate acidic conditions, the asr (acid shock RNA) gene is highly inducible and has been demonstrated to be crucial for growth at …

P03. Role Of Prefrontal Cortical Dopamine Transmission In Post-Traumatic Stress Disorder And Opiate Addiction Vulnerability, Jingjing Li

Western Research Forum

Background

PTSD and opiate addiction share strong co-morbidity and the inability to suppress obtrusive memory recall related to either stressful or rewarding experiences may be an underlying neuropsychological feature triggering PTSD and/or addiction. Our previous research has shown that dopamine (DA) transmission in the prefrontal cortex (PFC) strongly modulates emotional memory formation: activation of the DA D4 receptor (D4R) strongly potentiates the emotional salience of normally non-salient fear memories whereas DA D1 receptor (D1R) activation blocks the behavioural recall of fear memory. Thus, while intra-PFC D4 transmission strongly controls the acquisition of emotional memory, D1 transmission is selectively involved in …

P27. Acute Impact Of An Extremely Low Frequency Magnetic Stimulus On Human Neurophysiological Function - Magnetophosphene Perception, Cadence M. Baker

Western Research Forum

Background: Magnetophosphenes are classified as colourless, flickering lights that are perceived with closed eyes in the dark, and upon exposure to a magnetic field (MF). Uncertainties exist involving the MF threshold for magnetophosphene perception.

Methods: Forty subjects will be enrolled in this experiment aiming to provide a frequency-response curve of magnetophosphene perception under MF exposure. Subjects will sit in a whole head MF exposure device wearing a 64-channel MRI-compatible EEG cap. Subjects will be exposed to a MF with a frequency of 5-300 Hz, in the form of an increasing flux density ramp (increasing magnetic field flux density from 0-100 …

Pulmonary Surfactant Fortified With Cath-2 As A Novel Therapy For Bacterial Pneumonia, Brandon J. Baer

Western Research Forum

Background: Bacterial pneumonia is a leading cause of death worldwide, with high mortality rates persisting even after antibiotic treatment. Current treatments for pneumonia involve administration of antibiotics, however after the bacteria are killed they release toxic substances that induce inflammation and lung dysfunction. Host defense peptides represent a potential solution to this problem through their ability to down regulate inflammation. However, effective delivery to the lung is difficult because of the complex branching structure of the airways. My study addresses this delivery problem by using exogenous surfactant, a pulmonary delivery vehicle capable of improving spreading of these peptides throughout the …

The Effects Of Intrauterine Growth Restriction (Iugr) On The Pulmonary Surfactant And Lung Injury, Reza Khazaee

Western Research Forum

The Effects of Intrauterine Growth Restriction (IUGR) on the Pulmonary Surfactant and Lung Injury

Khazaee R¹, McCaig LA², Hardy D¹, Yamashita CM², Veldhuizen, RAW²

Department of Physiology and Pharmacology¹, Western University, London, ON, Canada. Lawson Health Research Institute², London, ON, Canada

Background: Acute respiratory distress syndrome (ARDS) is defined as severe lung dysfunction that occurs after an insult to the lung such as an infection. The lung dysfunction in ARDS is due to alterations to surfactant, a lipid-protein mixture coats the inside of the lung and …