Publications by authors named "Leslie E Stefanyk"

Background: Radical prostatectomy is the most common and effective treatment for localized prostate cancer. Unfortunately, radical prostatectomy is associated with urinary incontinence and has a significant negative impact on quality of life. Pelvic floor exercises are the most common non-invasive management strategy for urinary incontinence following radical prostatectomy; however, studies provide inconsistent findings regarding their efficacy.

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Background: Absences of normative, 10-20 % declines in blood pressure (BP) at night, termed nocturnal non-dipping, are linked to increased cardiovascular mortality risks. Current literature has linked these absences to psychological states, hormonal imbalance, and disorders involving hyper-arousal. This study focuses on evaluating associations between nocturnal non-dipping and indices of functional cardiac capacity and fitness.

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Objectives: Recently, we have demonstrated that FA transport proteins are located within the t-tubule fraction of rodent muscle, and that insulin stimulation causes their translocation to this membrane fraction. Chronic relocation of the FA transport protein FAT/CD36 to the sarcolemma is observed in obese rodents and humans, and correlates with intramuscular lipid accumulation and insulin resistance. It is not known whether in an obese, insulin resistant state FA transporters also chronically relocate to the t-tubules.

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Fatty acid (FA) transport proteins are known to exist on the sarcolemma of skeletal muscle. However, it is unknown whether the t-tubules, which comprise ~60% of the cell surface, also harbor these proteins. We examined FA transport proteins from both membrane fractions in unstimulated, insulin-stimulated and contracted skeletal muscle.

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This study investigated modifications to standing posture in response to elevated postural anxiety evoked by a potential physical threat to stability. Sixteen young adults, 16 older adults and 16 patients diagnosed with Parkinson's disease (PD) stood with or without the expectation of a threat to their posture (i.e.

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Leptin is an adipokine that increases fatty acid (FA) oxidation, decreases intramuscular lipid stores, and improves insulin response in skeletal muscle. In an attempt to elucidate the underlying mechanisms by which these metabolic changes occur, we administered leptin (Lep) or saline (Sal) by miniosmotic pumps to rats during the final 2 wk of a 6-wk low-fat (LF) or high-fat (HF) diet. Insulin-stimulated glucose transport was impaired by the HF diet (HF-Sal) but was restored with leptin administration (HF-Lep).

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Leptin administration increases fatty acid (FA) oxidation rates and decreases lipid storage in oxidative skeletal muscle, thereby improving insulin response. We have previously shown high-fat (HF) diets to rapidly induce skeletal muscle leptin resistance, prior to the disruption of normal muscle FA metabolism (increase in FA transport; accumulation of triacylglycerol, diacylglycerol, ceramide) that occurs in advance of impaired insulin signaling and glucose transport. All of this occurs within a 4-wk period.

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Agonists targeting the nuclear receptor peroxisome proliferator-activated receptors (PPAR)-delta may be potential therapeutic agents for insulin-resistant related conditions, as they may be able to stimulate fatty acid (FA) oxidation and attenuate the accumulation of harmful lipid species in skeletal muscle. Several reports have demonstrated that PPAR-delta agonists improve whole body insulin sensitivity. However, whether these agonists exert their direct effects on glucose and FA metabolism in skeletal muscle, and specifically with different fiber types, is unknown.

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The phospholipid composition of membranes can influence the physiological functioning of the cell or subcellular organelle. This association has been previously demonstrated in skeletal muscle, where cellular or subcellular membrane, specifically mitochondria, phospholipid composition is linked to muscle function. However, these observations are based on whole mixed skeletal muscle analysis, with little information on skeletal muscles of differing fiber-type compositions.

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Purpose Of Review: High-fat diets lead to obesity and increase the risk of developing insulin resistance and type 2 diabetes. Adipose tissue and skeletal muscle act as endocrine organs, and produce various cytokines that can potentially alter peripheral insulin sensitivity. The purpose of the present review is to briefly summarize the effects of major cytokines (leptin, adiponectin, tumor necrosis factor-alpha, and interleukin-6) on muscle metabolism and insulin response, with a focus on the effects of diet and exercise.

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