Matching Items (9)

In Vitro Osteogenic Study of hMSCs Under Diabetic Conditions

Description

Patients with type 2 diabetes mellitus experience a slower healing process and poor osteointegration, making it difficult for them to heal properly after a bone fracture. This study aims to

Patients with type 2 diabetes mellitus experience a slower healing process and poor osteointegration, making it difficult for them to heal properly after a bone fracture. This study aims to compare the proliferation and differentiation of human mesenchymal stromal cells at different glucose concentrations, as well as with an advanced glycated end-product (AGE) concentration, to mimic a healthy, prediabetic, and diabetic environment in an in vitro model over several experiments. Each experiment was composed of treatment groups in either growth or osteogenic media, with varying levels of glucose concentration or an advanced glycated end-product concentration. The treatment groups were cultured in 24 well plates over 28 days with staining of FITC-maleimide, DAPI, or alkaline phosphatase conducted at varying time points. The plates were imaged, then analyzed in ImageJ and GraphPad Prism. The study supports that at 28 days in culture, the more glucose added to osteogenic media treatment groups, the lower the nuclear count. At 14 days the same is true of growth media treatment groups, though the trend does not persist until 28 days. It does not seem that cell surface area of osteogenic groups, and growth media treatment groups was affected by glucose level. At 14 days, the alkaline phosphatase expression was unaffected by glucose level. However, at the 28 day time point the higher the glucose level of osteogenic treatment groups, the less expression of alkaline phosphatase. The effect of the added AGE concentration on hMSC osteogenesis was inconclusive. Overall, this study enhanced understanding of the role that glucose and AGEs play in the bone healing process for diabetic patients, allowing for future improvements of biomaterials and engineered tissue.

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  • 2019-05

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The Effects of Increased Standing and Light Physical Activity in the Workplace on Postprandial Glucose

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This thesis paper examines the effects of increased standing and light physical activity in the workplace on postprandial glucose. Sedentary behavior is detrimental to our health, affecting metabolic risk factors.

This thesis paper examines the effects of increased standing and light physical activity in the workplace on postprandial glucose. Sedentary behavior is detrimental to our health, affecting metabolic risk factors. An easy way to implement change is by decreasing sedentary time in workplaces where sitting is common, such as office workspaces. To consider how postprandial glucose is affected by decreasing sedentary time, participants ate a standardized meal for lunch and were asked to decrease their sitting time by replacing it with standing and light physical activity.

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Date Created
  • 2020-12

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Classification and Application of Electroactive Poly-Amidoamine Polymer (EPOP) for Use in Glucose Sensors

Description

Research concerning increased sensitivity and accurate glucose sensors have been on the forefront of diabetes mellitus. In this study, Electroactive Poly-Amidoamine Polymer (EPOP) was studied to determine if it can

Research concerning increased sensitivity and accurate glucose sensors have been on the forefront of diabetes mellitus. In this study, Electroactive Poly-Amidoamine Polymer (EPOP) was studied to determine if it can be used as a biocompatible electrode, with known redox mediators to determine if it can transfer its own electrons or amplify signal, and if signal is amplified when using an Ag/AgCl working electrode. From the results, it was determined that EPOP is neither a redox mediator, since it cannot transfer its own electrons, nor an electron mediator, since it does not amplify measured current at a specific voltage. Rather, it behaves as an electron sink capacitor with inconsistent behavior when Ag/AgCl is used as the working electrode with the redox mediator alone or with the redox mediator using in combination with glucose oxidase (GOx) and glucose. This was validated using AC-Impedance which gave a -3.3999 slope for isolated 0.05 g/mL EPOP in solution and R2 value of 0.992 displaying it had more capacitor-like behavior compared to resistor-like behavior. For this reason, EPOP was infused into a carbon screen-printed electrode by adding it dissolved and undissolved at two levels into carbon ink. The effectiveness of this electrode was tested using a potentiostatic CV. For the 0.1 g/mL EPOP dissolved in carbon ink, the reduction voltage peak (0.18 V) was found to be slightly higher than a GDE (0.14 V); however, the measured current was found to be 1.57 times the amplitude of a GDE. When 0.05 g/mL EPOP in PBS dissolved in graphite ink was used to detect glucose as the working electrode, there was increased signal amplification, and therefore, increased sensitivity to glucose when using EPOP infused electrodes. This offers promising results for disposable glucose sensors.

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Date Created
  • 2017-05

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DOSE-RESPONSE CHARACTERISTICS OF ISOFLURANE ON PLASMA GLUCOSE CONCENTRATIONS

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Abstract: Purpose: The dose-dependent effects of isoflurane anesthesia on insulin inhibition and insulin resistance were compared in rats. Methods: Three rats were entered into the procedure with each rat being

Abstract: Purpose: The dose-dependent effects of isoflurane anesthesia on insulin inhibition and insulin resistance were compared in rats. Methods: Three rats were entered into the procedure with each rat being subjected to 3 different doses of steady state concentrations of isoflurane (1.75%, 2.0%, and 2.50%). A surgical plane of anesthesia was induced by continuous infusion of isoflurane via an induction box at 4.0% isoflurane and when anesthesia was achieved the infusion of anesthesia was lowered to the steady state concentrations of isoflurane. Plasma glucose concentrations were measured every 10 minutes until two or three consistent peak values were observed. After assurance of reaching peak values sub-cutaneous insulin (0.75 units/kg) was injected between the scapulas. Following the insulin injection plasma glucose concentrations were obtained every 10 minutes via pinprick until peak minimal glucose values were reached. If the plasma glucose of any animal reached a level approximately 50 mg/dL, subcutaneous glucose was injected (2.0 grams/kg) to prevent adverse effects of hypoglycemia. Results: For absolute plasma glucose post-anesthetic values a comparison of multiple mean glucose concentrations (single factor ANOVA) yielded p=8.06 x 10-6. A post-hoc analysis revealed significant p values between 3 pairs of means: 1.75%/2.0%= 0.004; 1.75%/2.5%= 0.03; 2.0%/2.5%= 0.02 . For normalized plasma glucose values post-anesthetic a comparison of multiple means (ANOVA) yielded a p value of 0.03. Post-hoc analysis indicated that the peak response was at 2.0% with significant difference between 1.75%/2.0% =0.03 and 2.0%/2.5%=0.02. There was no significance between glucose values 1.75%/2.50%=0.68. For plasma glucose values post-insulin both absolute and normalized a mean comparison analysis (ANOVA) concluded that during post insulin the data was not statistically significant as p=0.68. Conclusions: When absolute plasma glucose concentrations were normalized by the baseline taken at conscious state the dose-dependency disappeared and concluded the largest change in plasma glucose at 2.0%. Although the data post-insulin injection was not statistically significant it can be concluded that there was normal glucose uptake and that there was no impaired insulin action on the skeletal muscle.

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Date Created
  • 2015-05

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Examining the Effect of Vinegar on Glucose Response

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The objective of this randomized, single-blind crossover study was to examine the effect of vinegar on the blood glucose response to meal ingestion. This study was associated with a

The objective of this randomized, single-blind crossover study was to examine the effect of vinegar on the blood glucose response to meal ingestion. This study was associated with a companion study Is Apple Cider Vinegar Effective for Reducing Heartburn Symptoms Related to Gastroesophageal Reflux Disease. Glucose meters were utilized to measure blood glucose levels immediately prior to, and at four ½ hour intervals following meal ingestion. Previous studies have demonstrated that vinegar modulates the meal-time glucose response. Hence an alternative hypothesis was used: that a significant difference will be observed between the control and the vinegar groups. The results from the study were not significant likely due to a small sample size. The test meal eaten with a drink composed of vinegar diluted in water appeared to be most effective at decreasing the overall change in postprandial blood glucose. The vinegar drink also played a role in decreasing the peak glucose level at 30 minutes post-meal.

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Date Created
  • 2015-05

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Oral Dextrose Gel in the Treatment of Neonatal Hypoglycemia: An Evidence Based Practice Change

Description

Background: Neonatal hypoglycemia (NH) is a common problem in the newborn period that resolves by 24-48 hours of life. Infants with known NH risk factors take longer to achieve blood

Background: Neonatal hypoglycemia (NH) is a common problem in the newborn period that resolves by 24-48 hours of life. Infants with known NH risk factors take longer to achieve blood glucose homeostasis. The leading cause of neonatal intensive care unit (NICU) admissions in otherwise healthy term and late preterm infants is NH.

Purpose: To determine the efficacy of dextrose gel in addition to oral feedings in NH treatment as compared to the previous practice of oral feedings alone. Lewin's change theory was used in staff education and project implementation.

Methods/Search Strategy: A keyword search of CINHAL, Cochrane, and PubMed with restrictions to English and publications within 5 years revealed supportive data for the practice change. IRB approval obtained prior to the practice change. Nurses screened all newborns for NH risk factors at birth at a tertiary hospital in the southwestern U.S. Infants with specific criteria received oral dextrose gel with timed follow-up blood glucose levels following an NH algorithm.

Findings/Results: Two groups of infants with similar gestational ages, birth weights, and risk factors for NH were compared pre and post-implementation of the EBP change. Infants in the first group (n=27) were all born prior to the start of the project and therefore were all treated with IV dextrose in the NICU after failing to maintain blood glucose levels within normal ranges with oral feedings alone. The second group of infants (n=27) was treated based on an updated NH algorithm after implementation of the use of oral dextrose gel. Of those 27 infants, 24 received oral dextrose gel for NH treatment. Of respiratory distress in addition to NH so these infants were excluded in the statistical analysis of NICU admissions. Therefore the post-implementation group only had 2 admission for primary diagnosis of NH. When comparing admission rates for hypoglycemia between the two groups, the first group had a 100% admission rate while the second group (those who received oral dextrose gel) only had a 9% admission rate for neonatal hypoglycemia (p<0.001). Upon further investigation it was found that these 2 infants admitted to the NICU with the diagnosis of NH had multiple risk factors present, including being infants of diabetic mothers which means they likely experienced refractory hypoglycemia after treatment with oral dextrose gel secondary to hyperinsulinism. Hyperinsulinism can lead to persistent and profound hypoglycemia in the newborn that is more difficult to treat, which is of clinical significance.

Implications for Practice: Early identification with timely follow-up blood glucose levels following intervention may be critical to successful treatment without requiring NICU admission. Nursing education and parental support are also paramount to success. If the change in NICU admissions for NH is statistically significant with a larger sample size, results may be shared with other facilities that traditionally transfer these infants for a higher level of care.

Implications for Research: Studies with larger sample size may generate more generalizable data with fewer outliers. Studies comparing neurodevelopmental outcomes among infants who received different NH treatments are necessary to determine long-term safety.

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Date Created
  • 2018-05-09

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Engineering the endothelial microenvironment

Description

Changes to the microenvironment of the endothelium can produce significant changes in the response of endothelial cells to stimuli. Human Aortic Endothelial Cells (HAECs) are tested in vitro for their

Changes to the microenvironment of the endothelium can produce significant changes in the response of endothelial cells to stimuli. Human Aortic Endothelial Cells (HAECs) are tested in vitro for their fluid shear stress response when their substrates, and the solute concentrations of the fluids to which they are exposed, are modulated, and for their nitric oxide expression when they are exposed to hyperglycemic conditions. ImageJ is used to quantify either the degree of cellular alignment and elongation with the direction of flow, or the relative NO expression using the fluorochrome DAF-2. First, the results of Brower, et.al. are replicated: HAECs under normal glucose (4mM) conditions align and elongate with flow (p<<0.05), while high glucose (30.5mM) conditions negate this effect (p<<0.05) and is likely the result of Advanced Glycation End-products (AGEs). Then, in this study it is found that substitution of fibronectin for gelatin substrates does not impair flow (p<<0.05), indicating that fibronectin likely does not participate in the initiation of vascular lesions. High palmitic acid also does not prevent HAEC shear response (p<<0.05), which is consistent with Brower's predictions that AGEs are responsible for impaired elongation and alignment. NO production is significantly increased (p<<0.025) in HAECs cultured 24 hours under high glucose (30.5mM) conditions compared with normal glucose (4mM) conditions, indicating the presence of inducible nitric oxide as part of an inflammatory response. Aminoguanidine (5mM) added to high glucose concentrations reduces, but does not eliminate NO production (p<<0.05), likely due to insufficient concentration. Modulation of the endothelial microenvironment leads to pronounced changes in HAEC behavior with regards to NO production under hyperglycemic conditions. Diabetic model rat aortas are explanted and imaged for the purpose of detecting aortic endothelial cell alignment and elongation; improvements in this method are discussed. A microvessel chamber used with explanted human tissue is re-fit to reduce required volumes of solutions and allow more effective experimentation.

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Date Created
  • 2013

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3D printed glucose monitoring sensor

Description

The American Diabetes Association reports that diabetes costs $322 billion annually and affects 29.1 million Americans. The high out-of-pocket cost of managing diabetes can lead to noncompliance causing serious and

The American Diabetes Association reports that diabetes costs $322 billion annually and affects 29.1 million Americans. The high out-of-pocket cost of managing diabetes can lead to noncompliance causing serious and expensive complications. There is a large market potential for a more cost-effective alternative to the current market standard of screen-printed self-monitoring blood glucose (SMBG) strips. Additive manufacturing, specifically 3D printing, is a developing field that is growing in popularity and functionality. 3D printers are now being used in a variety of applications from consumer goods to medical devices. Healthcare delivery will change as the availability of 3D printers expands into patient homes, which will create alternative and more cost-effective methods of monitoring and managing diseases, such as diabetes. 3D printing technology could transform this expensive industry. A 3D printed sensor was designed to have similar dimensions and features to the SMBG strips to comply with current manufacturing standards. To make the sensor electrically active, various conductive filaments were tested and the conductive graphene filament was determined to be the best material for the sensor. Experiments were conducted to determine the optimal print settings for printing this filament onto a mylar substrate, the industry standard. The reagents used include a mixture of a ferricyanide redox mediator and flavin adenine dinucleotide dependent glucose dehydrogenase. With these materials, each sensor only costs $0.40 to print and use. Before testing the 3D printed sensor, a suitable design, voltage range, and redox probe concentration were determined. Experiments demonstrated that this novel 3D printed sensor can accurately correlate current output to glucose concentration. It was verified that the sensor can accurately detect glucose levels from 25 mg/dL to 400 mg/dL, with an R2 correlation value as high as 0.97, which was critical as it covered hypoglycemic to hyperglycemic levels. This demonstrated that a 3D-printed sensor was created that had characteristics that are suitable for clinical use. This will allow diabetics to print their own test strips at home at a much lower cost compared to SMBG strips, which will reduce noncompliance due to the high cost of testing. In the future, this technology could be applied to additional biomarkers to measure and monitor other diseases.

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Date Created
  • 2017

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Synthesis, characterizations and applications of mesoporous carbon composites

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This dissertation provides a fundamental understanding of the properties of mesoporous carbon based materials and the utilization of those properties into different applications such as electrodes materials for super capacitors,

This dissertation provides a fundamental understanding of the properties of mesoporous carbon based materials and the utilization of those properties into different applications such as electrodes materials for super capacitors, adsorbents for water treatments and biosensors. The thickness of mesoporous carbon films on Si substrates are measured by Ellipsometry method and pore size distribution has been calculated by Kelvin equation based on toluene adsorption and desorption isotherms monitored by Ellipsometer. The addition of organometallics cobalt and vanalyl acetylacetonate in the synthesis precursor leads to the metal oxides in the carbon framework, which largely decreased the shrink of the framework during carbonization, resulting in an increase in the average pore size. In addition to the structural changes, the introduction of metal oxides into mesoporous carbon framework greatly enhances the electrochemical performance as a result of their pseudocapacitance. Also, after the addition of Co into the framework, the contraction of mesoporous powders decreased significantly and the capacitance increased prominently because of the solidification function of CoO nanoparticles. When carbon-cobalt composites are used as adsorbent, the adsorption capacity of dye pollutant in water is remarkably higher (90 mg/g) after adding Co than the mesoporous carbon powder (2 mg/g). Furthermore, the surface area and pore size of mesoporous composites can be greatly increased by addition of tetraethyl orthosilicate into the precursor with subsequent etching, which leads to a dramatic increase in the adsorption capacity from 90 mg/g up to 1151 mg/g. When used as electrode materials for amperometric biosensors, mesoporous carbons showed good sensitivity, selectivity and stability. And fluorine-free and low-cost poly (methacrylate)s have been developed as binders for screen printed biosensors. With using only 5wt% of poly (hydroxybutyl methacrylate), the glucose sensor maintained mechanical integrity and exhibited excellent sensitivity on detecting glucose level in whole rabbit blood. Furthermore, extremely high surface area mesoporous carbons have been synthesized by introducing inorganic Si precursor during self-assembly, which effectively determined norepinephrine at very low concentrations.

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Date Created
  • 2012