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Quantifying The Effect Of A Novel Topical Hyaluronic-Acid Phosphatidylethanolamine Cream On The Epidermis, Caitlin J. Symonette

Electronic Thesis and Dissertation Repository

With aging, keratinocytes have diminished proliferative capacity resulting in atrophic skin with reduced barrier function. This investigation evaluates the effect of daily topical applications of a novel high-molecular weight hyaluronan cream (HA-PE) on keratinocyte renewal and epidermal thickness. Unmodified hyaluronan and HA-PE were mixed separately into a vehicle cream. Each topical formulation was applied daily onto the shaved backs of aged female C57BL6 mice. Full-thickness biopsies of treated skin were obtained for analysis of keratinocyte proliferation, keratinocyte differentiation, and local inflammation at days 1, 5, and 10 of cream application. In addition, a cardiac puncture was performed for serum C-reactive …

Role Of Sirt1 In Vascular Complications Of Diabetes, Rokhsana Mortuza

Electronic Thesis and Dissertation Repository

Chronic diabetic complications are significant causes of morbidity. In diabetes, as the cellular changes are similar to aging, we investigated the role of sirtuins (SIRTs) in chronic diabetic complications.

We examined glucose and aging-induced changes in the endothelial cells (ECs), the primary targets of chronic diabetic complications. ECs in high glucose showed evidences of early senescence, being more pronounced in microvascular ECs in association with decreased SIRT1 and FOXO1-dependent reduction in antioxidant gene expressions. A regulatory relationship of deacetylator SIRT1 and histone acetylator p300 was identified. Renal and retinal tissues of diabetic animals showed similar results.

Having established such changes, …

Older Woman Workers: Met And Unmet Needs For Health And Wellbeing In The Workplace, Gillian Gorfine

Electronic Thesis and Dissertation Repository

Older women workers report experiencing occupational injustices however the literature focuses on barriers faced rather than understanding the needs-based strategies empowering women as they age at work. This study engaged women aged 55 and older in a participatory action research project defining and examining strategies for older women workers’ health and wellbeing. In Phase 1, a key informant advisory group (N = 4) defined the problem and guided the design of an open answer survey conducted with 72 older women in work. Three categories emerged informing the fundamental, instrumental, and contextual needs of older women workers. Meeting fundamental needs may …

Decreased Peak Muscle Power Is Associated With Motor Unit Loss In The Lower Limb Of Older Adults, Neal B. Mckinnon

Electronic Thesis and Dissertation Repository

This study investigated the relationship between motor unit (MU) properties and the strength and power of two lower limb muscles in healthy young and old adults. Twelve older adults (mean age, 77 ± 5 yrs) and twelve young adults (mean age, 24 ± 3 yrs) were studied. MU properties of the tibialis anterior (TA) and vastus medialis (VM) muscles were determined using decomposition-enhanced spike-triggered averaging (DE-STA). Motor unit number estimates (MUNE) of the TA were significantly reduced (p>0.05) in older adults (102 ± 76) compared to young adults (234 ± 109), primarily as a result of significantly larger surface-detected …

Specific Cognitive Domains Associated With Gait Performance In Mild Cognitive Impairment, Elyse M. Gordon

Electronic Thesis and Dissertation Repository

The study aim was to identify associations between deficits in specific cognitive domains and gait performance in Mild Cognitive Impairment (MCI). Sixty-eight participants with MCI underwent cognitive function testing in executive function (EF), attention, working memory, episodic memory and language domains. Gait was assessed using an electronic walkway (GaitRite®). The means and co-efficient of variation of five gait parameters were evaluated: velocity, stride time, stride length, step width and double support time during single (SG) and dual-task (DT) test conditions Multivariable linear regression analysis demonstrated deficits in EF, working memory and episodic memory were significantly associated with increased gait variability …

Quantifying The Effect Of Age And Contraction Mode On The Force-Velocity-Power Relationship In The Knee Extensors, Justin R. Paturel

Electronic Thesis and Dissertation Repository

PURPOSE: To assess and compare the force-velocity-power relationship (F-V-P) using isotonic and isokinetic knee extensions in 11 younger (19-30y) and 11 older (69-81y) men. METHODS: The construction of the F-V-P curves were attained with each participant performing maximal, explosive knee extensions at 8 different loads (isotonic) and 8 different velocities (isokinetic) on a Cybex HUMAC NORM dynamometer. Maximal voluntary contraction (MVC or P_o), maximal shortening velocity (V_max), maximum power, optimal torque (P_opt) and velocity (V_opt) were assessed and compared. RESULTS: The older men were 43% weaker, 18% slower and ~54% less powerful …

The Effects Of Age And Long-Term Endurance Training On Vo2 Kinetics, Tyler M. Grey

Electronic Thesis and Dissertation Repository

The kinetics of the adjustment of pulmonary oxygen uptake (VO₂) was examined during step transitions from 20 W to moderate-intensity cycling in young (Y), middle-aged (M), and older (O) endurance trained and untrained men. VO_2p was measured breath-by-breath and changes in deoxygenated hemoglobin ([HHb]) were measured by near-infrared spectroscopy. VO_2p and [HHb] were modeled with a monoexponential model. The kinetic time constant for VO₂ (τVO_2p) was not different across age-groups (P > 0.05) in the trained group (17 ± 8, 18 ± 5, and 20 ± 5 s, in Y, M, and O, respectively). …