Matching Items (12)
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- All Subjects: Diabetes
- Creators: School of Nutrition and Health Promotion
- Creators: Herman, Richard
- Member of: Theses and Dissertations
- Member of: Barrett, The Honors College Thesis/Creative Project Collection
Description
Noninvasive neuromodulation could help treat many neurological disorders, but existing techniques have low resolution and weak penetration. Ultrasound (US) shows promise for stimulation of smaller areas and subcortical structures. However, the mechanism and parameter design are not understood. US can stimulate tail and hindlimb movements in rats, but not forelimb, for unknown reasons. Potentially, US could also stimulate peripheral or enteric neurons for control of blood glucose.
To better understand the inconsistent effects across rat motor cortex, US modulation of electrically-evoked movements was tested. A stimulation array was implanted on the cortical surface and US (200 kHz, 30-60 W/cm2 peak) was applied while measuring changes in the evoked forelimb and hindlimb movements. Direct US stimulation of the hindlimb was also studied. To test peripheral effects, rat blood glucose levels were measured while applying US near the liver.
No short-term motor modulation was visible (95% confidence interval: -3.5% to +5.1% forelimb, -3.8% to +5.5% hindlimb). There was significant long-term (minutes-order) suppression (95% confidence interval: -3.7% to -10.8% forelimb, -3.8% to -11.9% hindlimb). This suppression may be due to the considerable heating (+1.8°C between US
on-US conditions); effects of heat and US were not separable in this experiment. US directly evoked hindlimb and scrotum movements in some sessions. This required a long interval, at least 3 seconds between US bursts. Movement could be evoked with much shorter pulses than used in literature (3 ms). The EMG latency (10 ms) was compatible with activation of corticospinal neurons. The glucose modulation test showed a strong increase in a few trials, but across all trials found no significant effect.
The single motor response and the long refractory period together suggest that only the beginning of the US burst had a stimulatory effect. This would explain the lack of short-term modulation, and suggests future work with shorter pulses could better explore the missing forelimb response. During the refractory period there was no change in the electrically-evoked response, which suggests the US stimulation mechanism is independent of normal brain activity. These results challenge the literature-standard protocols and provide new insights on the unknown mechanism.
To better understand the inconsistent effects across rat motor cortex, US modulation of electrically-evoked movements was tested. A stimulation array was implanted on the cortical surface and US (200 kHz, 30-60 W/cm2 peak) was applied while measuring changes in the evoked forelimb and hindlimb movements. Direct US stimulation of the hindlimb was also studied. To test peripheral effects, rat blood glucose levels were measured while applying US near the liver.
No short-term motor modulation was visible (95% confidence interval: -3.5% to +5.1% forelimb, -3.8% to +5.5% hindlimb). There was significant long-term (minutes-order) suppression (95% confidence interval: -3.7% to -10.8% forelimb, -3.8% to -11.9% hindlimb). This suppression may be due to the considerable heating (+1.8°C between US
on-US conditions); effects of heat and US were not separable in this experiment. US directly evoked hindlimb and scrotum movements in some sessions. This required a long interval, at least 3 seconds between US bursts. Movement could be evoked with much shorter pulses than used in literature (3 ms). The EMG latency (10 ms) was compatible with activation of corticospinal neurons. The glucose modulation test showed a strong increase in a few trials, but across all trials found no significant effect.
The single motor response and the long refractory period together suggest that only the beginning of the US burst had a stimulatory effect. This would explain the lack of short-term modulation, and suggests future work with shorter pulses could better explore the missing forelimb response. During the refractory period there was no change in the electrically-evoked response, which suggests the US stimulation mechanism is independent of normal brain activity. These results challenge the literature-standard protocols and provide new insights on the unknown mechanism.
ContributorsGulick, Daniel Withers (Author) / Kleim, Jeffrey (Thesis advisor) / Towe, Bruce (Thesis advisor) / Muthuswamy, Jitendran (Committee member) / Herman, Richard (Committee member) / Helms Tillery, Steven (Committee member) / Arizona State University (Publisher)
Created2015
Description
Brown adipose tissue (BAT) is thought to be important in combating obesity as it can expend energy in the form of heat, e.g. thermogenesis. The goal of this study was to study the effect of injected norepinephrine (NE) on the activation of BAT in rats that were fed a high fat diet (HFD). A dose of 0.25 mg/kg NE was used to elicit a temperature response that was measured using transponders inserted subcutaneously over the BAT and lower back and intraperitoneally to measure the core temperature. The results found that the thermic effect of the BAT increased after the transition from low fat diet to a high fat diet (LFD) yet, after prolonged exposure to the HFD, the effects resembled levels found with the LFD. This suggests that while a HFD may stimulate the effect of BAT, long term exposure may have adverse effects on BAT activity. This may be due to internal factors that will need to be examined further.
ContributorsSion, Paul William (Author) / Herman, Richard (Thesis director) / Borges, Chad (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
According to the CDC, diabetes is the 7th leading cause of death in the U.S. and rates are continuing to rise nationally and internationally. Chronically elevated blood glucose levels can lead to type 2 diabetes and other complications. Medications can be used to treat diabetes, but often have side effects. Lifestyle and diet modifications can be just as effective as medications in helping to improve glycemic control, and prevent diabetes or improve the condition in those who have it. Studies have demonstrated that consuming vinegar with carbohydrates can positively impact postprandial glycemia in diabetic and healthy individuals. Continuous vinegar intake with meals may even reduce fasting blood glucose levels. Since vinegar is a primary ingredient in mustard, the purpose of this study was to determine if mustard consumption with a carbohydrate-rich meal (bagel and fruit juice) had an effect on the postprandial blood glucose levels of subjects. The results showed that mustard improved glycemia by 17% when subjects consumed the meal with mustard as opposed to the control. A wide variety of vinegars exists. The defining ingredient in all vinegars is acetic acid, behind the improvement in glycemic response observed with vinegar ingestion. Vinegar-containing foods range from mustard, to vinaigrette dressings, to pickled foods. The benefits of vinegar ingestion with carbohydrates are dose-dependent, meaning that adding even small amounts to meals can help. Making a conscious effort to incorporate these foods into meals, in addition to an overall healthy lifestyle, could provide an additional tool for diabetics and nondiabetics alike to consume carbohydrates in a healthier manner.
ContributorsJimenez, Gabriela (Author) / Johnston, Carol (Thesis director) / Lespron, Christy (Committee member) / School of Nutrition and Health Promotion (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
The development of the Diabetic Physiological state is influenced by the Receptor for Advanced Glycation End Products (RAGE). This receptor was discovered in 1992, and the accumulation of research on this subject has been extensive. Structural characterization studies of the RAGE protein have shown that it is a transmembrane protein that binds a number of different motile ligands. The diversity of ligands that can attach to the binding domain is the primary factor that allows for RAGE to exhibit its wide-range effects on host cells. Two different studies were completed: one study dealt with the role of IAPP in beta cell death, and the second study was related to RAGE influence on cardiomyocytes and, more specifically, it was related to cardiac cell death. After the completion of the two studies, a comprehensive report was written for each topic. The two papers were merged into a single document. Molecular studies are important for understanding the underlying mechanisms that motivate pathophysiological presentation. In addition to a molecular understanding of the development of diabetes, a clinical research study was completed through the examination of appropriate literature sources. This clinical aspect allowed for the progression of different phases in the research process. A relationship between vinegar and lower plasma glucose was found. The exact mechanism behind this relationship will be studied in the future.
ContributorsGonzalez, Matthew Joseph (Author) / Johnston, Carol (Thesis director) / Collins, Michael (Committee member) / Barrett, The Honors College (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2015-05
Description
Background: The prevalence of childhood obesity has disproportionately affected Latino youth. This increase in obesity is seen with an increased incidence of Type 2 Diabetes. Objective/Hypothesis: The objective of this study was to determine the effects of a community based lifestyle intervention, which encompassed nutrition education and physical activity, on diabetes risk in pre-diabetic Latino adolescents. Diabetes risk was assessed using pancreatic beta cell function as measured by proinsulin: insulin ratio. It was hypothesized that reductions in added sugar intake and reductions in saturated fat intake will be associated with improved beta cell function as measured by proinsulin: insulin ratio. Study Design/Participants: In this quasi-experimental study design, n=17 pre-diabetic Latino adolescents between the ages of 14-16 participated in a lifestyle intervention. Methods: Anthropometric measurements (weight, height, waist circumference, BMI) and body composition (body %) were determined for all participants at baseline and post intervention. Fasting proinsulin (PI), fasting insulin (I) and 2hr-OGTT were also determined. Dietary intake was measured using the Block Kids Food Screener for kids ages 2-17y (2007). The intervention consisted of nutrition education classes and physical activity sessions for 12 weeks. Results: We found significant decreases in body fat % following the intervention. There were no significant decreases in fasting insulin. Proinsulin significantly decreased. However we did no see a significant change in PI/I (p= 0.003). Dietary behaviors of added sugar (p=0.03) and saturated fat (p=0.04) showed significant decreases. No significant associations were found between changes in added sugar to improvements in beta cell function, r=0.072, p-value= 0.7. We also did not observe significant associations between reductions in saturated fat intake and improvements in beta cell function, r=0.152, p-value =0.6. Conclusions: We concluded that a 12-week lifestyle intervention resulted in significant changes in dietary behaviors. These changes were not however associated with improvements in beta cell function.
ContributorsKaur, Manroop (Author) / Shaibi, Gabriel (Thesis director) / Bruening, Meredith (Committee member) / Barrett, The Honors College (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2015-05
Description
There has been an alarming rise in the prevalence of obesity which has been attributed to the paralleled rise in consumption of high-fat foods. It’s commonly accepted that high-fat diets can lead to increased weight gain, however not all fats have the same physiological action. This study primarily focuses on the effect of canola oil, a monounsaturated fat, on energy homeostasis and body composition when it’s given as a supplement to a high-fat diet composed of saturated fatty acid. Rodent models were divided into three dietary groups: 1) low-fat diet (LFD), 2) high-fat diet (HFD) and 3) canola oils supplemented HFD (HF+CAN). After 4 weeks of dietary intervention, samples of epididymal fat, perinephric fat, and liver were analyzed across the three groups to see if the changes in energy homeostasis could be explained by the cellular behavior and composition of these tissues. Interestingly, the supplement of canola oil appeared to reverse the deleterious effects of a saturated fat diet, reverting energy intake, body weight gain and adipose tissue sizes to that (if not lower than that) of the LFD group. The only exception to this effect was the liver: the livers remained larger and fattier than those of the HFD. This occurrence is possibly due to a decrease in free fatty acid uptake in the adipose tissues—resulting in smaller adipose tissue sizes—and increased fatty acid uptake in the liver. The mechanism by which this occurs has yet to be elucidated and will be the primary focus of upcoming studies on the effect of monounsaturated fat on other diets.
ContributorsZuo, Connie Wanda (Author) / Washo-Krupps, Delon (Thesis director) / Deviche, Pierre (Committee member) / Herman, Richard (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
Turmeric is the bright yellow root that has been used as a spice, healing remedy, and textile dye. Previous studies have suggested that the most active ingredient in turmeric, curcumin, could reduce serum cholesterol concentration. However, most of these studies were conducted on animals and not many have been done on controlled human trials. This randomized, double-blinded, controlled crossover study evaluates the effects of turmeric on blood cholesterol concentrations including total cholesterol, LDL cholesterol, HLD cholesterol, and triglycerides. In this study, eight healthy participants between the ages of 18 and 45 were randomized to receive either 500mg capsules of turmeric or placebo for a period of three weeks. Following a wash-out period of five weeks, all participants were crossed over to the alternative treatment for another three weeks. After comparing the 3 week treatment and placebo phases, turmeric showed no significant effect on serum lipid concentrations. Furthermore, a slight increase in total cholesterol concentrations was observed following the turmeric phase when compared to the placebo phase.
ContributorsDo, Ngoc Bich Thi (Author) / Johnston, Carol (Thesis director) / Whisner, Corrie (Committee member) / School of Nutrition and Health Promotion (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Type II diabetes is a serious, chronic metabolic disease that has serious impacts on both the health and quality of life in patients diagnosed with the disease. Type II diabetes is also a very prevalent disease both in the United States and around the world. There is still a lot that is unknown about Type II diabetes, and this study will aim to answer some of these questions. The question posed in this study is whether insulin resistance changes as a function of time after the start of a high fat diet. We hypothesized that peripheral insulin resistance would be observed in animals placed on a high fat diet; and peripheral insulin resistance would have a positive correlation with time. In order to test the hypotheses, four Sprague-Dawley male rats were placed on a high fat diet for 8 weeks, during which time they were subjected to three intraperitonal insulin tolerance tests ((NovoLogTM 1 U/kg). These three tests were conducted at baseline (week 1), week 4, and week 8 of the high fat diet. The test consisted of serially determining plasma glucose levels via a pin prick methodology, and exposing a droplet of blood to the test strip of a glucometer (ACCUCHEKTM, Roche Diagnostics). Two plasma glucose baselines were taken, and then every 15 minutes following insulin injection for one hour. Glucose disposal rates were then calculated by simply dividing the glucose levels at each time point by the baseline value, and multiplying by 100. Area under the curve data was calculated via definite integral. The area under the curve data was then subjected to a single analysis of variance (ANOVA), with a statistical significance threshold of p<0.05. The results of the study did not indicate the development of peripheral insulin resistance in the animals placed on a high fat diet. Insulin-mediated glucose disposal was about 50% at 30 minutes in all four animals, during all three testing periods. Furthermore, the ANOVA resulted in p=0.92, meaning that the data was not statistically significant. In conclusion, peripheral insulin resistance was not observed in the animals, meaning no determination could be made on the relation between time and insulin resistance.
ContributorsBrown, Kellen Andrew (Author) / Caplan, Michael (Thesis director) / Herman, Richard (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
Turmeric, scientifically known as Curcuma longa, is a tropical plant that is most often consumed in India.1 The rhizome of the plant is dried and then ground into a fine, vibrant yellow powder. In addition to its function as a spice, turmeric is also used in traditional Ayervedic medicine due to its unique medical properties. These unique properties are attributed to the three major constituents of turmeric: curcumin, α-isocurcumin, and β-isocurcumin.2 Curcumin (Diferuloylmethane; C21H20O6), makes up 5% of turmeric by weight, and is the most prominent active ingredient within the turmeric root. Perhaps the most intriguing characteristic about curcumin is its ability to modulate targets such as, but not limited to, transcription factors, enzymes, apoptosis genes, and growth factors.1 Modern medical research has determined curcumin to be a viable treatment and prevention method for disease such as type II diabetes mellitus, rheumatoid arthritis, liver cirrhosis, and certain cancers. However, research on turmeric’s effects on gastrointestinal health is significantly lacking. This randomized, double-blind, cross-over trial looked to see if supplemental turmeric (500 mg as dried root powder) would significantly raise breath hydrogen emission (BHE) and reduce small bowel transit time (SBTT) in 8 female adults who were suffering from chronic constipation. Although supplemental turmeric did not significantly impact BHE or SBTT, the number of bowel movements greatly increased during turmeric intervention.
ContributorsUgarte, Noel (Author) / Johnston, Carol (Thesis director) / Whisner, Corrie (Committee member) / School of Nutrition and Health Promotion (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
The purpose of this cookbook is to provide pre-diabetic, type 1 and type 2 diabetics with a foundation of recipes. These recipes have been created with the intent of regulating inflammation which can be caused by such metabolic abnormalities. I want to educate patients who suffer from these conditions that there are several ingredients that work alongside their condition rather than feeling that they are limited to foods and recipes. I want to increase patients moral and self-efficacy to explore and work with new ingredients. These series of recipes should be used as a guide to trying new foods however patients should know that they are able to add their own ingredients that are suitable to their liking or condition.
ContributorsBhuyan, Nikita (Author) / Grant, Shauna (Thesis director) / Morse, Lisa (Committee member) / School of Nutrition and Health Promotion (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2018-12