Browsing by Author "Hart, David Arthur"

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    Diet-induced obesity leads to pro-inflammatory alterations to the vitreous humour of the eye in a rat model
    (Springer Nature, 2018-02) Collins, Kelsey H.; Herzog, Walter; Reimer, Raylene A.; Reno, Carol R.; Heard, Bryan J.; Hart, David Arthur
    The purpose of this study was to investigate if diet-induced obesity (DIO) and subsequent low-level systemic inflammation would result in local increases in pro-inflammatory mediators in the vitreous humour (VH) of the eyes of rats.
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    Examining the effects of diet on muscle health in a female diet-induced obesity rat model
    (2024-01-24) Smith, Hannah Elizabeth; Herzog, Walter; Reimer De Bruyn, Raylene; Hart, David Arthur; Joumaa, Venus A
    Worldwide obesity has tripled in the last 50 years as energy dense food and low activity levels common in westernized societies have become the norm. The excess fat associated with obesity, puts significant stress on the body’s metabolic pathways, leading to many noncommunicable diseases, including certain musculoskeletal (MSK) disorders, such as sarcopenic obesity. Sarcopenic obesity is the loss of muscle mass and strength coupled with an excess fat mass and fatty infiltrations into the muscle tissue called myosteatosis. Fortunately, obesity is modifiable through diet interventions as it has been previously shown that prebiotic fibre supplementation can decrease body fat percentage and improve metabolic health. However, there are a lack of studies to date that look at the effect of a prebiotic fibre on compromised muscle integrity as a consequence of obesity. To study fat infiltration in muscle tissue, a diet-induced obesity model was developed in male Sprague-Dawley rats, however, female animals were neglected to be considered. The purpose of this thesis was to (1) establish a model of diet-induced obesity in female Sprague-Dawley rats and compare changes in muscle integrity to the already existing male model and (2) determine the effect of a 3-week delayed prebiotic fibre supplement on intramuscular fat infiltration. Through a combination of histological staining techniques and measures of metabolic syndrome and inflammatory cytokines, we quantified intramuscular fat, fibrosis, local inflammation, metabolic dysfunction, and systemic inflammation. It was determined that the diet-induced obesity model in female Sprague-Dawley rats is a viable model and that sex-dependent differences in intramuscular fat infiltration exist. We also observed that the 3-week delayed prebiotic fibre diet supplement was able to protect against certain consequences of obesity such as increased blood triglycerides and fat infiltration in the vastus lateralis, but not others such as fat infiltration in the soleus and systemic inflammation associated with metabolic endotoxemia.
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    The Effect of Low Oxygen Level on Human Mesenchymal Stem Cell Behaviour in Culture
    (2016) Heik, Evelyn; Sen, Arindom; Duncan, Neil Alexander; Hart, David Arthur; Murari, Kartikeya; Ponnurangam, Sathish
    Synovial fluid from articulating joints contain a population of mesenchymal stem cells (SF-MSCs), which have the ability to effectively form cartilage, and thus represent a potential candidate cell type for the development of therapies aimed at repairing cartilage lesions. Since they can only be isolated in small quantities and any treatment developed will require a large number of them, SF-MSCs for clinical use will have to be generated in culture under conditions that promote their rapid proliferation. Determining the optimal oxygen levels in serum-free medium, free of ill-defined components and infectious agents, would allow for a better understanding of SF-MSCs and their potential for use in clinical treatments. The findings of this study indicate that culturing SF-MSCs under serum-free conditions in static culture is feasible, and that low oxygen conditions may improve cell yield. Furthermore, the cells maintained their defining stem cell characteristics when cultured under low oxygen tension.