Matching Items (13)
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- All Subjects: Diabetes
- Creators: Harrington Bioengineering Program
- Creators: Pizziconi, Vincent
- Creators: Lespron, Christy
Description
Diabetes mellitus is a disease characterized by many chronic and acute conditions. With the prevalence and cost quickly increasing, we seek to improve on the current standard of care and create a rapid, label free sensor for glycated albumin (GA) index using electrochemical impedance spectroscopy (EIS). The antibody, anti-HA, was fixed to gold electrodes and a sine wave of sweeping frequencies was induced with a range of HA, GA, and GA with HA concentrations. Each frequency in the impedance sweep was analyzed for highest response and R-squared value. The frequency with both factors optimized is specific for both the antibody-antigen binding interactions with HA and GA and was determined to be 1476 Hz and 1.18 Hz respectively in purified solutions. The correlation slope between the impedance response and concentration for albumin (0 \u2014 5400 mg/dL of albumin) was determined to be 72.28 ohm/ln(mg/dL) with an R-square value of 0.89 with a 2.27 lower limit of detection. The correlation slope between the impedance response and concentration for glycated albumin (0 \u2014 108 mg/dL) was determined to be -876.96 ohm/ln(mg/dL) with an R-squared value of 0.70 with a 0.92 mg/dL lower limit of detection (LLD). The above data confirms that EIS offers a new method of GA detection by providing unique correlation with albumin as well as glycated albumin. The unique frequency response of GA and HA allows for modulation of alternating current signals so that several other markers important in the management of diabetes could be measured with a single sensor. Future work will be necessary to establish multimarker sensing on one electrode.
ContributorsEusebio, Francis Ang (Author) / LaBelle, Jeffrey (Thesis director) / Pizziconi, Vincent (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2014-05
Description
Diabetes is a growing epidemic in developing countries, specifically in rural Kenya. In addition to the high cost of glucose testing, many diabetics in Kenya do not understand the importance of testing their blood glucose, let alone the nature of the disease. This project addresses the insufficiency of educational materials regarding diabetes in rural Kenya. The resulting documents can easily be adjusted for use in other developing countries.
ContributorsBuchak, Jacqueline (Author) / Caplan, Michael (Thesis director) / Snyder, Jan (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2014-05
Description
Currently, the management of diabetes mellitus (DM) involves the monitoring of only blood glucose using self-monitoring blood glucose devices (SMBGs) followed by taking interventional steps, if needed. To increase the amount of information that diabetics can have to base DM care decisions off of, the development of an insulin biosensor is explored. Such a biosensor incorporates electrochemical impedance spectroscopy (EIS) to ensure an extremely sensitive platform. Additionally, anti-insulin antibody was immobilized onto the surface of a gold disk working electrode to ensure a highly specific sensing platform as well. EIS measurements were completed with a 5mV sine wave that was swept through the frequency spectrum of 100 kHz to 1 Hz on concentrations of insulin ranging from 0 pM to 100 μM. The frequency at which the interaction between insulin and its antibody was optimized was determined by finding out at which frequency the R2 and slope of the impedance-concentration plot were best. This frequency, otherwise known as the optimal binding frequency, was determined to be 459 Hz. Three separate electrodes were developed and the impedance data for each concentration measured at 459 Hz was averaged and plotted against the LOG (pM insulin) to construct the calibration curve. The response was calculated to be 263.64 ohms/LOG(pM insulin) with an R2 value of 0.89. Additionally, the average RSD was determined to be 19.24% and the LLD was calculated to be 8.47 pM, which is well below the physiological normal range. These results highlight the potential success of developing commercial point-of-care insulin biosensors or multi-marker devices operating with integrated insulin detection.
ContributorsDecke, Zachary William (Author) / LaBelle, Jeffrey (Thesis director) / Pizziconi, Vincent (Committee member) / Cook, Curtiss (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2013-05
Description
The purpose of this study, which was done in conjunction with the Arizona Heart Foundation, was to evaluate whether pyridoxine accelerates ulcer wound healing in diabetic patients with ulcers in the lower extremities. In this study, 100 mg of pyridoxine per day was given to patients in the experimental group (while they receive normal wound treatment) while patients in the control group received normal treatment of wounds without the pyridoxine. Over time, wound healing was evaluated by photographing and then measuring the size of patients' ulcer wounds on the photographs. Results from the experimental group were compared with those of the control group to evaluate the efficacy of the pyridoxine treatment. In addition, comparisons of the healing rates were made with respect to whether the patients smoked, had hypertension or hypotension, and the patients' body mass indexes. It has been found that there was no statistically significant difference in the mean healing rates between the control groups and experimental groups. In addition, it has been found that smoking, BMI and blood pressure did not have a statistically appreciable effect on the difference in mean healing rates between the control and experimental groups. This is evidence that pyridoxine did not have a statistically significant effect on wound healing rates.
ContributorsHaupt, Shawn Anthony (Author) / Caplan, Michael (Thesis director) / Pauken, Christine (Committee member) / Pagan, Pedro (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2013-05
Description
A point of care glucose sensor using electrochemical impedance spectroscopy (EIS) with a glutaraldehyde-linked enzyme shows promise as an effective biosensor platform. This report details the characterization of various factors on optimal binding frequency (OBF) and sensor performance to better prepare the sensor for future experimentation. Utilizing a screen printed carbon electrode, the necessary amount of glucose oxidase was determined to be 10 mg/mL. Binding time trials ranging from 1-3 minutes demonstrated that 1.5 minutes was the optimal binding time. This timeframe produced the strongest impedance response at each glucose concentration. Using this enzyme concentration and binding time, the native OBF of the biosensor was found to be 1.18 Hz using vector analysis. Temperature testing showed little change in OBF in sensors exposed to 4 \u00B0C through 43.3 \u00B0C. Only exposure to 60 \u00B0C resulted in rapid OBF change which was likely due to glucose oxidase becoming denatured. Humidity tests showed little change in OBF and sensor performance between sensors prepared at the humidities of 7.5%, 10.625% and 16.5% humidity. Alternatively, solutions containing common interference molecules such as uric acid, acetaminophen, and ascorbic acid resulted in a highly shifted OBF and drastically reduced signal.
ContributorsMatloff, Daniel (Co-author) / Khanwalker, Mukund (Co-author) / Johns, Jared (Co-author) / LaBelle, Jeffrey (Thesis director) / Pizziconi, Vincent (Committee member) / Lin, Chi (Committee member) / Dean, W.P. Carey School of Business (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
With dwindling water resources due to drought and other pressures, water utilities are seeking to tap into alternative water sources as a means to improve water sustainability. Reclaimed water consists of treated wastewater and is widely used for non-potable purposes, such as irrigation, both agricultural and recreational. However, the reclaimed water distribution system can be subject to substantial regrowth of microorganisms, including opportunistic pathogens, even following rigorous disinfection. Factors that can influence regrowth include temperature, organic carbon levels, disinfectant type, and the time transported (i.e., water age) in the system. One opportunistic pathogen (OP) that is critical to understanding microbial activity in both reclaimed and drinking water distribution systems is Acanthamoeba. In order to better understand the potential for this amoeba to proliferate in reclaimed water systems and influence other OPs, a simulated reclaimed water distribution system was studied. The objective of this study was to compare the prevalence of Acanthamoeba and one of its endosymbionts, Legionella, across varying assimilable organic carbon (AOC) levels, temperatures, disinfectants, and water ages in a simulated reclaimed water distribution system. The results of the study showed that cooler temperatures, larger water age, and chlorine conditions yielded the lowest detection of Acanthamoeba gene copies per mL or cm2 for bulk water and biofilm samples, respectively.
ContributorsDonaldson, Kandace (Author) / Ankeny, Casey (Thesis director) / Edwards, Marc (Committee member) / Pruden, Amy (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
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
Falls are known to be a common occurrence and a costly one as well, as they are the second leading cause of unintentional deaths and millions of other injuries worldwide. Falls often occur due to an increase in trunk flexion angle, so this experiment aims to reduce the trunk flexion received while stepping over an obstacle. To achieve this a soft actuator was attached to the trunk and pressure was sent as subjects walked and stepped over an obstacle presented on a treadmill. The pressure is meant to stiffen the back which should in theory reduce the trunk flexion angle and lower the chances of falling. In this experiment, two groups were tested: three participants from a control group (healthy young adults) and three participants from an experimental group (healthy elderly adults). Since elderly adults have the highest fall risk due to overall lack of stability, they are the experimental group and the focus for this experiment. The results from the study showed that elderly adults had a beneficial effect with the soft actuator as there was a noticeable difference in trunk flexion when the device was attached. The experiment also supported prior research that stated that trunk flexion was greater in elderly adults than younger adults. Despite the positive results, further studies should be done to prove that the soft devices influence lowering trunk flexion angle as well as to see if the device has any noticeable effect on younger adults.
ContributorsFisher, Caleb (Author) / Lee, Hyunglae (Thesis director) / Olivas, Alyssa (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2023-05
Description
The effects of iron and chromium blood concentrations have been linked to blood glucose control in diabetics. It is suggested that iron causes oxidative stress in the beta cells of the pancreas and adipocytes creating insulin insufficiency and resistance. Chromium is believed to increase the action of insulin through its biologically active molecule chromodulin. Both of these mechanisms are not clear. This 20 week case study tests the feasibility of combining iron depletion therapy followed by chromium supplementation to improve insulin sensitivity. This single case study followed a protocol of two blood donations separated by eight weeks followed by chromium supplementation of 250 µg of chromium picolinate once a day four weeks after the second blood donation. Fasting blood draws were taken at baseline, post blood draws and pre and post chromium supplementation. Results were not promising for the first hypothesis of lowering HbA1c, but the results were promising for the second hypothesis of improving insulin sensitivity by lowering the HOMA score.
ContributorsJarrett, Nia (Author) / Johnston, Carol (Thesis advisor) / Lespron, Christy (Committee member) / Mayol-Kreiser, Sandra (Committee member) / Arizona State University (Publisher)
Created2015
Description
The glycation of plasma proteins leading to the production of advanced glycation end products (AGEs) and subsequent damage is a driving factor in the pathophysiology of diabetic complications. The overall research objective was to elucidate the mechanisms by which birds prevent protein glycation in the presence of naturally high plasma glucose concentrations. This was accomplished through the specific purpose of examining the impact of temperature and glucose concentration on the percent glycation of chicken serum albumin (CSA) in comparison to human serum albumin (HSA). Purified CSA and HSA solutions prepared at four different glucose concentrations (0 mM, 5.56 mM, 11.11 mM, and 22.22 mM) were incubated at three different temperatures (37.0°C, 39.8°C, and 41.4°C) on separate occasions for seven days with aliquots extracted on days 0, 3, and 7. Samples were analyzed by LC-ESI-MS for percent glycation of albumin. The statistically significant interaction between glucose concentration, temperature, albumin type, and time as determined by four-way repeated measures ANOVA (p = 0.032) indicated that all independent variables interacted to affect the mean percent glycation of albumin. As glucose concentration increased, the percent glycation of both HSA and CSA increased over time at all temperatures. In addition, HSA was glycated to a greater extent than CSA at the two higher glucose concentrations examined for all temperature conditions. Temperature differentially affected percent glycation of HSA and CSA wherein glycation increased with rising temperatures for HSA but not CSA. The results of this study suggest an inherent difference between the human and chicken albumin that contributes to the observed differences in glycation. Further research is needed to characterize this inherent difference in an effort to elucidate the mechanism by which birds protect plasma proteins from glycation. Future related work has the potential to lead to the development of novel therapies to prevent or reverse protein glycation prior to the formation of AGEs in humans, thus preventing the development and devastating effects of numerous diabetic complications.
ContributorsZuck, Jessica (Author) / Sweazea, Karen (Thesis advisor) / Johnston, Carol (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2016