Matching Items (22)
Filtering by

Clear all filters

135546-Thumbnail Image.png
Description
Traumatic brain injury (TBI) may result in numerous pathologies that cannot currently be mitigated by clinical interventions. Stem cell therapies are widely researched to address TBI-related pathologies with limited success in pre-clinical models due to limitations in transplant survival rates. To address this issue, the use of tissue engineered scaffolds

Traumatic brain injury (TBI) may result in numerous pathologies that cannot currently be mitigated by clinical interventions. Stem cell therapies are widely researched to address TBI-related pathologies with limited success in pre-clinical models due to limitations in transplant survival rates. To address this issue, the use of tissue engineered scaffolds as a delivery mechanism has been explored to improve survival and engraftment rates. Previous work with hyaluronic acid \u2014 laminin (HA-Lm) gels found high viability and engraftment rates of mouse fetal derived neural progenitor/stem cells (NPSCs) cultured on the gel. Furthermore, NPSCs exposed to the HA-Lm gels exhibit increased expression of CXCR4, a critical surface receptor that promotes cell migration. We hypothesized that culturing hNPCs on the HA-Lm gel would increase CXCR4 expression, and thus enhance their ability to migrate into sites of tissue damage. In order to test this hypothesis, we designed gel scaffolds with mechanical properties that were optimized to match that of the natural extracellular matrix. A live/dead assay showed that hNPCs preferred the gel with this optimized formulation, compared to a stiffer gel that was used in the CXCR4 expression experiment. We found that there may be increased CXCR4 expression of hNPCs plated on the HA-Lm gel after 24 hours, indicating that HA-Lm gels may provide a valuable scaffold to support viability and migration of hNPCs to the injury site. Future studies aimed at verifying increased CXCR4 expression of hNPCs cultured on HA-Lm gels are necessary to determine if HA-Lm gels can provide a beneficial scaffold for stem cell engraftment therapy for treating TBI.
ContributorsHemphill, Kathryn Elizabeth (Author) / Stabenfeldt, Sarah (Thesis director) / Brafman, David (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
135402-Thumbnail Image.png
Description
It is unknown which regions of the brain are most or least active for golfers during a peak performance state (Flow State or "The Zone") on the putting green. To address this issue, electroencephalographic (EEG) recordings were taken on 10 elite golfers while they performed a putting drill consisting of

It is unknown which regions of the brain are most or least active for golfers during a peak performance state (Flow State or "The Zone") on the putting green. To address this issue, electroencephalographic (EEG) recordings were taken on 10 elite golfers while they performed a putting drill consisting of hitting nine putts spaced uniformly around a hole each five feet away. Data was collected at three time periods, before, during and after the putt. Galvanic Skin Response (GSR) measurements were also recorded on each subject. Three of the subjects performed a visualization of the same putting drill and their brain waves and GSR were recorded and then compared with their actual performance of the drill. EEG data in the Theta (4 \u2014 7 Hz) bandwidth and Alpha (7 \u2014 13 Hz) bandwidth in 11 different locations across the head were analyzed. Relative power spectrum was used to quantify the data. From the results, it was found that there is a higher magnitude of power in both the theta and alpha bandwidths for a missed putt in comparison to a made putt (p<0.05). It was also found that there is a higher average power in the right hemisphere for made putts. There was not a higher power in the occipital region of the brain nor was there a lower power level in the frontal cortical region during made putts. The hypothesis that there would be a difference between the means of the power level in performance compared to visualization techniques was also supported.
ContributorsCarpenter, Andrea (Co-author) / Hool, Nicholas (Co-author) / Muthuswamy, Jitendran (Thesis director) / Crews, Debbie (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
136771-Thumbnail Image.png
DescriptionMy main goal for my thesis is in conjunction with the research I started in the summer of 2010 regarding the creation of a TBI continuous-time sensor. Such goals include: characterizing the proteins in sensing targets while immobilized, while free in solution, and while in free solution in the blood.
ContributorsHaselwood, Brittney (Author) / LaBelle, Jeffrey (Thesis director) / Pizziconi, Vincent (Committee member) / Cook, Curtiss (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2011-12
136253-Thumbnail Image.png
Description
The endogenous response of neural stem cell/progenitor (NPSC) recruitment to the brain injury environment following a traumatic brain injury (TBI) is currently under heavy investigation. Mechanisms controlling NPSC proliferation and migration to the brain injury environment remain unclear; however, it is thought that the vascular extracellular matrix proteins (e.g. laminin,

The endogenous response of neural stem cell/progenitor (NPSC) recruitment to the brain injury environment following a traumatic brain injury (TBI) is currently under heavy investigation. Mechanisms controlling NPSC proliferation and migration to the brain injury environment remain unclear; however, it is thought that the vascular extracellular matrix proteins (e.g. laminin, fibronectin, and vitronectin) and vascular endothelial growth factor (VEGF) play a role in mediating NPSC behavior through vasophillic interactions. This project attempts to uncover potential VEGF-ECM crosstalk in mediating migration and proliferation. To investigate migration, neurospheres were seeded on ECM-coated wells supplemented with VEGF and without VEGF, and neural outgrowth was measured at days 0, 1, 3, and 8 using differential interference contrast microscopy. Furthermore, single-cell NPSCs were seeded on ECM-coated Transwell membranes with VEGF supplemented media on one side and without VEGF to look at chemotactic migration. Migrated NPSCs were visualized with DAPI nuclear stain and imaged with an inverted fluorescent microscope. To investigate NPSC proliferation, NPSCs were seeded on ECM coated plates as in the radial migration assay and visualized with EdU on day 8. Total proliferation was measured by seeding NPSCs on ECM coated 96-well plates and incubating them with MTT on days 3 and 6. Proliferation was measured using a spectrophotometer at 630nm and 570nm wavelengths. It was found that VEGF-laminin crosstalk synergistically increased radial migration, but may not play a role in chemotactic migration. Understanding the mechanisms behind VEGF-laminin crosstalk in NPSC proliferation and migration may provide crucial information for the design of stem cell transplantation therapies in the future.
ContributorsMillar-Haskell, Catherine Susan (Author) / Stabenfeldt, Sarah (Thesis director) / Addington, Caroline (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2015-05
133734-Thumbnail Image.png
Description
Prior expectations can bias evaluative judgments of sensory information. We show that information about a performer's status can bias the evaluation of musical stimuli, reflected by differential activity of the ventromedial prefrontal cortex (vmPFC). Moreover, we demonstrate that decreased susceptibility to this confirmation bias is (a) accompanied by the recruitment

Prior expectations can bias evaluative judgments of sensory information. We show that information about a performer's status can bias the evaluation of musical stimuli, reflected by differential activity of the ventromedial prefrontal cortex (vmPFC). Moreover, we demonstrate that decreased susceptibility to this confirmation bias is (a) accompanied by the recruitment of and (b) correlated with the white-matter structure of the executive control network, particularly related to the dorsolateral prefrontal cortex (dlPFC). By using long-duration musical stimuli, we were able to track the initial biasing, subsequent perception, and ultimate evaluation of the stimuli, examining the full evolution of these biases over time. Our findings confirm the persistence of confirmation bias effects even when ample opportunity exists to gather information about true stimulus quality, and underline the importance of executive control in reducing bias.
ContributorsAydogan, Goekhan (Co-author, Committee member) / Flaig, Nicole (Co-author) / Larg, Edward W. (Co-author) / Margulis, Elizabeth Hellmuth (Co-author) / McClure, Samuel (Co-author, Thesis director) / Nagishetty Ravi, Srekar Krishna (Co-author) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
137180-Thumbnail Image.png
Description
The main objective of this research is to develop and characterize a targeted contrast agent that will recognize acute neural injury pathology (i.e. fibrin) after traumatic brain injury (TBI). Single chain fragment variable antibodies (scFv) that bind specifically to fibrin have been produced and purified. DSPE-PEG micelles have been produced

The main objective of this research is to develop and characterize a targeted contrast agent that will recognize acute neural injury pathology (i.e. fibrin) after traumatic brain injury (TBI). Single chain fragment variable antibodies (scFv) that bind specifically to fibrin have been produced and purified. DSPE-PEG micelles have been produced and the scFv has been conjugated to the surface of the micelles; this nanoparticle system will be used to overcome limitations in diagnosing TBI. The binding and imaging properties will be analyzed in the future to determine functionality of the nanoparticle system in vivo.
ContributorsRumbo, Kailey Michelle (Author) / Stabenfeldt, Sarah (Thesis director) / Kodibagkar, Vikram (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2014-05
132964-Thumbnail Image.png
Description
In epilepsy, malformations that cause seizures often require surgery. The purpose of this research is to join forces with the Multi-Center Epilepsy Lesion Detection (MELD) project at University College London (UCL) in order to improve the process of detecting lesions in patients with drug-resistant epilepsy. This, in turn, will improve

In epilepsy, malformations that cause seizures often require surgery. The purpose of this research is to join forces with the Multi-Center Epilepsy Lesion Detection (MELD) project at University College London (UCL) in order to improve the process of detecting lesions in patients with drug-resistant epilepsy. This, in turn, will improve surgical outcomes via more structured surgical planning. It is a global effort, with more than 20 sites across 5 continents. The targeted populations for this study include patients whose epilepsy stems from Focal Cortical Dysplasia. Focal Cortical Dysplasia is an abnormality of cortical development, and causes most of the drug-resistant epilepsy. Currently, the creators of MELD have developed a set of protocols which wrap various
commands designed to streamline post-processing of MRI images. Using this partnership, the Applied Neuroscience and Technology Lab at PCH has been able to complete production of a post-processing pipeline which integrates locally sourced smoothing techniques to help identify lesions in patients with evidence of Focal Cortical Dysplasia. The end result is a system in which a patient with epilepsy may experience more successful post-surgical results due to the
combination of a lesion detection mechanism and the radiologist using their trained eye in the presurgical stages. As one of the main points of this work is the global aspect of it, Barrett thesis funding was dedicated for a trip to London in order to network with other MELD project collaborators. This was a successful trip for the project as a whole in addition to this particular thesis. The ability to troubleshoot problems with one another in a room full of subject matter
experts allowed for a high level of discussion and learning. Future work includes implementing machine learning approaches which consider all morphometry parameters simultaneously.
ContributorsHumphreys, Zachary William (Author) / Kodibagkar, Vikram (Thesis director) / Foldes, Stephen (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
133469-Thumbnail Image.png
Description
Vagal Nerve Stimulation (VNS) has been shown to be a promising therapeutic technique in treating many neurological diseases, including epilepsy, stroke, traumatic brain injury, and migraine headache. The mechanisms by which VNS acts, however, are not fully understood but may involve changes in cerebral blood flow. The vagus nerve plays

Vagal Nerve Stimulation (VNS) has been shown to be a promising therapeutic technique in treating many neurological diseases, including epilepsy, stroke, traumatic brain injury, and migraine headache. The mechanisms by which VNS acts, however, are not fully understood but may involve changes in cerebral blood flow. The vagus nerve plays a significant role in the regulation of heart rate and cerebral blood flow that are altered during VNS. Here, we examined the effects of acute vagal nerve stimulation on both heart rate and cerebral blood flow. Laser Speckle Contrast Analysis (LASCA) was used to analyze the cerebral blood flow of male Long\u2014Evans rats. Results showed two distinct patterns of responses whereby animals either experienced a mild or severe decrease in heart rate during VNS. Further, animals that displayed mild heart rate decreases showed an increase in cerebral blood flow that persisted beyond VNS. Animals that displayed severe decreases showed a transient decrease in cerebral blood flow followed by an increase that was greater than that observed in mild animals but progressively decreased after VNS. The results suggest two distinct patterns of changes in both heart rate and cerebral blood flow that may be related to the intensity of VNS.
ContributorsHillebrand, Peter Timothy (Author) / Kleim, Jeffrey (Thesis director) / Helms Tillery, Stephen (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
132852-Thumbnail Image.png
Description
Traumatic brain injury (TBI) can result in many pathologies, one of which being coagulopathy. TBI can progress to hemorrhagic lesions and increased intercranial pressure leading to coagulopathy. The coagulopathy has been linked to poor clinical outcomes and occurs in 60% of severe TBI cases. To improve hemostasis, synthetic platelets (SPs)

Traumatic brain injury (TBI) can result in many pathologies, one of which being coagulopathy. TBI can progress to hemorrhagic lesions and increased intercranial pressure leading to coagulopathy. The coagulopathy has been linked to poor clinical outcomes and occurs in 60% of severe TBI cases. To improve hemostasis, synthetic platelets (SPs) have been repurposed. SPs are composed of a poly(N-isopropylacrylamide-co-acrylic-acid) microgel, conjugated with a fibrin-specific antibody and are biomimetic in their ability to deform and collapse within a fibrin matrix. The objective of this study is to diminish coagulopathy with a single, intravenous injection of SPs, and subsequently decrease neuropathologies. TBI was modeled in animal cohorts using the well-established controlled cortical impact and SPs were injected 2-3 hours post-injury. Control cohorts received no injection. Brain tissue was harvested at acute (24h) and delayed (7 days) time points post-TBI, and fluorescently imaged to quantify reactive astrocytes (GFAP+), microglial morphology and presence (Iba1+), and tissue lesion spared. SP-treatment resulted in significant reduction of GFAP expression at 7 days post-TBI. Furthermore, SP-treatment significantly reduced the percent difference from 24h to 7 days in microglia/macrophage per field compared to the control. For microglial morphology, SP-treated cohorts observed a significant percent difference in endpoints per soma from 24h to 7 days compared to untreated cohorts. However, microglial branch length significantly decreased in percent difference from 24h to 7 days when compared to the control. Finally, tissue sparing did not significantly decrease between 24h and 7 day for SP-treated cohorts as was observed in untreated cohorts, implying inhibition of delayed necrosis. Overall, these results suggest decreased neuroinflammation by 7 days, supporting SPs as potentially therapeutic post-TBI.
ContributorsTodd, Jordan Cecile (Author) / Stabenfeldt, Sarah (Thesis director) / Bharadwaj, Vimala (Committee member) / Harrington Bioengineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
134788-Thumbnail Image.png
Description
Concussions and traumatic brain injuries are mechanical events which can derive from no specific activity or event. However, these injuries occur often during athletic and sporting events but many athletes experiencing these symptoms go undiagnosed and continue playing without proper medical attention. The current gold standard for diagnosing athletes with

Concussions and traumatic brain injuries are mechanical events which can derive from no specific activity or event. However, these injuries occur often during athletic and sporting events but many athletes experiencing these symptoms go undiagnosed and continue playing without proper medical attention. The current gold standard for diagnosing athletes with concussions is to have medical professionals on the sidelines of events to perform qualitative standardized assessments which may not be performed frequently enough and are not specialized for each athlete. The purpose of this report is to discuss a study sanctioned by Arizona State University's Project HoneyBee and additional affiliations to validate a third-party mouth guard device product to recognize and detect force impacts blown to an athlete's head during athletic activity. Current technology in health monitoring medical devices can allow users to apply this device as an additional safety mechanism for early concussion awareness and diagnosis. This report includes the materials and methods used for experimentation, the discussion of its results, and the complications which occurred and areas for improvement during the preliminary efforts of this project. Participants in the study were five non-varsity ASU Wrestling athletes who volunteered to wear a third-party mouth guard device during sparring contact at practice. Following a needed calibration period for the devices, results were recorded both through visual observation and with the mouth guard devices using an accelerometer and gyroscope. This study provided a sound understanding for the operation and functionality of the mouth guard devices. The mouth guard devices have the capability to provide fundamental avenues of research for future investigations.
ContributorsTielke, Austin Wyatt (Author) / Ross, Heather (Thesis director) / LaBelle, Jeffrey (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12