Medicine and Health Sciences Commons^™

How Different Insulin Administration Routes Affect Hepatic Glycogen Levels After An Aerobic Exercise Bout In Male Rats With Type 1 Diabetes, Amit P. Sayal Mr.

Electronic Thesis and Dissertation Repository

Type 1 diabetes mellitus (T1DM) is an autoimmune disease resulting in the destruction of pancreatic beta cells leading to deficient insulin production. Insulin plays a crucial role in regulating glucose metabolism, facilitating the utilization of dietary energy. Individuals with T1DM exhibit dysregulated blood glucose concentration and necessitate exogenous insulin administration. Intensive insulin therapy (IIT) is employed commonly, typically via subcutaneous (SQ) injections to treat individuals with T1DM. However, SQ insulin delivery fails to mimic endogenous insulin secretion, particularly its physiological distribution directly to the liver via the hepatic portal vein. Insulin concentration in the liver contributes significantly to glucose homeostasis, …

Assessment Of Executive Function Using A Series Of Operant Conditioning Based Tasks In T1dm Rodents, Kevin T. Murphy

Electronic Thesis and Dissertation Repository

This study examined the impact of Type 1 Diabetes Mellitus (T1DM) on executive function using a series of operant conditioning based tasks in rats. Sprague Dawley rats were randomized to either non-diabetic (n = 12; 6 male) or diabetic (n = 14; 6 male) groups. Diabetes was induced using multiple low-dose streptozotocin injections. All diabetic rodents were insulin-treated using subcutaneous insulin pellet implants. At week 14 of the study, rats were placed on a food restricted diet to induce 5 - 10% weight loss. Rodents were familiarized and tested on a series of tasks that required continuous adjustments to novel …

Developing A Model To Assess The Contribution Of Cytokeratin 19-Expressing Cells During Multipotent Stromal Cell-Induced Islet Regeneration, Brianna Ananthan

Electronic Thesis and Dissertation Repository

Previously, pharmacological activation of Wnt-signaling in human bone marrow-derived multipotent stromal cells (hMSC) generated conditioned media (CM) that promoted β-cell regeneration in streptozotocin-treated mice. Ductal-derived endocrine progenitors, which have been shown to generate β-cells following pancreatic injury, represent a candidate for the ‘signal-receiving cell’. Ductal (CK19+) cells from mice pancreata obtained by purification of live Dolichos Biflorus Agglutinin lectin+ cells and cultured in minimal media supplemented with Untreated, Wnt-activated, or Wnt-inhibited CM demonstrated a significantly increased proportion of EdU+/CK19+ cells following 48-hours of supplementation but no endocrine phenotype acquisition. Lineage-tracing CK19-CreERT;Ai9(RCL-tdT) mice treated with tamoxifen (single dose) demonstrated specific labeling …

The Difference In A1c Of Children And Adolescents With Type 1 Diabetes Mellitus Using Carbohydrate Counting Compared To Those Using A Structured Meal Plan, Alia El Kubbe

Electronic Thesis and Dissertation Repository

Carbohydrate counting (CHO) is a nutrition education tool used by patients with type 1 diabetes mellitus (T1DM). The primary objective was to assess glycated hemoglobin (A1C) in participants with T1DM using CHO counting vs. those using a structured meal plan (SMP). The secondary objectives were to determine if BMI-for-age, parental income, parental involvement, and mothers’ educational level were associated with their children’s glycemic control. A cross sectional study was conducted, where participants aged 4-18 years, or their parents completed a survey. Total sample size was 88 participants (77 in the CHO counting group and 11 in the SMP group). There …

Effect Of N-Acetyl-L-Cysteine Prevention Or Intervention On Diet Induced Beta Cell Compensation And Dysfunction, Madison Wallace

Electronic Thesis and Dissertation Repository

Type 2 diabetes mellitus (T2DM) progression increases oxidative stress which contributes to beta cell compensation and eventual dysfunction. To investigate the role of antioxidant N-acetyl-L-cysteine (NAC) on beta cell function and pancreatic stellate cell activation (aSMA⁺) during early and late stages of compensation, NAC was used for preventative (p) and intervention (i) treatments in C57BL/6N mice fed a 60% kcal high-fat diet (HFD) for 8 or 22 weeks. Significantly improved glucose tolerance was observed at 22 weeks following pNAC treatment in HFD mice. Although 22-week HFD mice displayed hyperinsulinemia, beta cell hypertrophy, decreased beta cell PDX-1 nuclear localization, …

The Feasibility Of Square-Stepping Exercise As A Universal Intervention For Older Adults With Chronic Disease To Improve Cognitive And Physical Function, Erin M. Shellington

Electronic Thesis and Dissertation Repository

Square-stepping exercise (SSE) is a cognitive training program with a physical component. An instructor demonstrates a stepping pattern across a gridded mat and participants are required to memorize and repeat the patterns on their own. In community-dwelling older adults, SSE has demonstrated some benefits on global cognitive functioning (GCF), balance, functional fitness, and social interaction.

Aims: to investigate the feasibility and efficacy of SSE in varied populations and settings to improve mobility and cognition. Populations included older adults with: knee osteoarthritis (OA), type 2 diabetes mellitus (T2DM) and self-reported cognitive complaints (sCC), and those living in long-term care (LTC) …

A Clinico-Pathological Study Of The Structural And Functional Changes In The Retina And Optic Nerve Following Diabetic Retinopathy Treatments, Richard Filek

Electronic Thesis and Dissertation Repository

Diabetic retinopathy (DR) is the result of microvascular changes in the retina due to hyperglycemia which alter the blood-retinal barrier (BRB). The increased permeability of BRB results in the accumulation of extracellular fluid, the development of diabetic macular edema (DME) and capillary occlusion. Capillary occlusion results in retinal ischemia which increases vascular endothelial growth factor (VEGF) levels, increases vascular permeability and results in neovascularization in proliferative diabetic retinopathy (PDR) patients. The treatments clinically used for DR are panretinal photocoagulation (PRP) for PDR and injectable vascular endothelial growth factor inhibitors (anti-VEGFs) for DME.

The safety of PRP and anti-VEGF therapy on …

Postnatal Β1 Integrin Deficiency In Pancreatic Beta-Cells Impairs Function And Survival, Jason E. Peart

Electronic Thesis and Dissertation Repository

Integrin β1 is essential for pancreatic beta-cell development and maintenance throughout life in rodents and human fetal islets. However, the effects of a postnatal β1 integrin knockout (β1KO) specific to pancreatic beta-cells of mice is undetermined. We generated mice with CreERT recombinase specific to the mouse insulin promoter (MIP), allowing us to induce a β1KO upon injection of tamoxifen (MIPβ1KO model).

At 3-4 weeks of age tamoxifen was injected and mice were sacrificed at 8 (male) and 16 weeks (female) post-tamoxifen. MIPβ1KO mice had impaired glucose tolerance, reduced beta-cell mass and islet density. The impairment in glucose tolerance remained in …

The Effect Of Aerobic Exercise Training On Hepatic Glycogen Metabolism In Type 1 Diabetic Rats, Michael Murray

Electronic Thesis and Dissertation Repository

The purpose of this investigation was to determine if ten weeks of aerobic exercise training could increase hepatic glycogen storage in rats with Type 1 Diabetes Mellitus (T1DM) and whether elevated hepatic glycogen content is associated with alterations in glycogenic proteins and insulin signaling. Rats were divided into control-sedentary, control-exercised, T1DM-sedentary and T1DM-exercised groups. Animals from each group underwent a euglycemic-hyperinsulinemic clamp at the conclusion of the study. Exercise training consisted of treadmill running at 27m/min, 6% incline for 1hr, five days/week for ten weeks. T1DM rats had lower liver glycogen concentrations than control rats and glycogen was not increased …

The Role Of Il-22 Produced By Th17 Cells In Type 1 Diabetes, Stacey M. Bellemore

Electronic Thesis and Dissertation Repository

Interleukin-22 (IL-22) is produced by T helper 17 (Th17) cells. Th17 cells have been shown to be pathogenic in autoimmune diseases, however their role in type 1 diabetes (T1D) remains controversial. We have shown that Th17-differentiation of naïve T cells can be driven by IL-23 + IL-6 to produce large amounts of IL-22 and induce T1D. Conversely, polarizing T cells using TGF-β + IL-6 led to nonpathogenic Th17 cells that produced lower IL-22 levels. We have shown that neutralizing IFN-γ during polarization leads to a drastic increase in IL-22. We have also found IL-22-producing cells in the pancreas of diabetic …

Risk Factors For Diabetes Mellitus: A Comparative Analysis Of Subpopulation Differences In A Large Canadian Sample, Michael James Taylor

Electronic Thesis and Dissertation Repository

Objectives: Certain Canadian subpopulations observe numerous modifiable and non-modifiable risk factors for diabetes. This study compares immigrants and Aboriginals (First Nations, Inuit, and Métis) with Canada-born individuals at higher risks for diabetes, and deciphers the determinant differences between them.

Methods: Pooled Canadian Community Health Survey data (2001-2010) were used. Time trends for diabetes within each subsample were calculated using individual survey year prevalence rates; diabetes diagnoses were self-reported (N=33,565). Various risk factors were also examined using logistic regression.

Results: Diabetes prevalence rates significantly increased from 2001 to 2010 for each subpopulation, as well as the total sample: Canada-Born individuals (3.9% …