Biomedical Engineering and Bioengineering Commons^™

Ultraviolet-B Radiation Induces Release Of Bioactive Microvesicle Particles In Keratinocytes Via Platelet-Activating Factor And Acid Sphingomyelinase, Langni Liu

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Ultraviolet-B (UV-B) radiation is one of the most common environmental factors and is known to induce the production of bioactive agents that cause several diseases including skin cancer. UVB exposure stimulates the production of a phospholipid activator, platelet-activating factor (PAF), and its analogs in keratinocytes that activate the PAF receptor (PAF-R) resulting in acute inflammatory and delayed systematic immunosuppressive effects. However, as UVB only penetrates into the skin epidermal layer, the detailed mechanisms of how UVB exerts systematic effects remains unclear. Previously we found that UVB induces keratinocytes to release large numbers of microvesicle particles (MVPs). These small membrane-bound particles …

Global Identification Of Human Modifier Genes Of Alpha-Synuclein Toxicity, Ishita Haider

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Alpha-synuclein is a small lipid binding protein abundantly expressed in the brain. Lewy body or Lewy-like pathology, primarily composed of misfolded alpha-synuclein, is a pathological feature shared by several neurodegenerative disorders, including Parkinson's disease (PD). Both missense mutations and increased copy numbers of the SNCA gene, encoding the alpha-synuclein protein, have been genetically linked to autosome dominant PD. Other genetic variations affecting the expression of the SNCA gene have been associated with sporadic PD. Although the physiological function of alpha-synuclein is not well understood, its localization to plasma and vesicular membranes at the presynaptic terminals suggests a role in neurotransmission. …

Kv2.1 Channel Clustering In The Sod1-G93a Mouse Model Of Als, Joshua Christopher Harris

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Kv2.1 channels mediate slow-activating K+ rectifier current within the membrane of spinal motoneurons (MNs), and they are known to co-localize with other synapses and ion channels. Although Kv2.1 channels are suggested to regulate MN excitability, little research has gone into investigating its potential contribution to MN-altered excitability in Amyotrophic Lateral Sclerosis (ALS). Using the male SOD1-G93A mouse model of ALS, we examined Kv2.1 cluster area and density in lumbar MNs at four key stages of disease progression. In our experiments, MNs were separated by type via SK3 immunoreactivity in order to isolate and compare the responses of disease-resistant (slow; SK3+) …

High Gravity Fermentation Of Sugarcane Bagasse Hydrolysate By Saccharomyces Pastorianus To Produce Economically Distillable Ethanol Concentrations: Necessity Of Medium Components Examined, Sarah W. Harcum, Thomas P. Caldwell

Open Access Publishing Fund

A major economic obstacle in lignocellulosic ethanol production is the low sugar concentrations in the hydrolysate and subsequent fermentation to economically distillable ethanol concentrations. We have previously demonstrated a two-stage fermentation process that recycles xylose with xylose isomerase to increase ethanol productivity, where the low sugar concentrations in the hydrolysate limit the final ethanol concentrations. In this study, three approaches are combined to increase ethanol concentrations. First, the medium-additive requirements were investigated to reduce ethanol dilution. Second, methods to increase the sugar concentrations in the sugarcane bagasse hydrolysate were undertaken. Third, the two-stage fermentation process was recharacterized with high gravity …

The Effect Of Intermittent Theta Burst Stimulation On Biceps Corticomotor Excitability In Non-Impaired Individuals And Individuals With Tetraplegia, Blaize Majdic

Theses and Dissertations

Neuromodulation of the primary motor cortex (M1) in pair with physical therapy may be a promising method for improving motor outcomes after spinal cord injury (SCI). Increased excitability of the corticospinal motor pathways (i.e. corticomotor excitability) has shown to be associated with improved motor learning and skill acquisition. Intermittent theta burst stimulation (iTBS) is a form of non-invasive brain stimulation which can increase corticomotor excitability, as measured by an increase in the amplitude of motor evoked potentials (MEPs). However, the ability for iTBS to increase the corticomotor excitability of proximal muscles such as the biceps, and muscles affected by spinal …

Formulation And Validation Of Nanoparticle Controlled Delivery For Chemotherapeutic Drug Products, Shani L. Levit

Theses and Dissertations

Taxol, a formulation of paclitaxel (PTX), is one of the most widely used anticancer drugs, particularly for treating recurring ovarian carcinomas following surgery. Clinically, PTX is used in combination with other drugs such as lapatinib (LAP) to increase treatment efficacy. Delivering drug combinations with nanoparticles has the potential to improve chemotherapy outcomes. In this study, we use Flash NanoPrecipitation, a rapid, scalable process to encapsulate weakly hydrophobic drugs (logP in vitro. Encapsulating either PTX or LAP into nanoparticles increases drug potency. When PTX and LAP are co-loaded in the same nanoparticle, they have a synergistic effect that is greater than …

Development Of A Torque-Based Device For The Quantification Of Arm Rigidity In Patients With Parkinson’S Disease, Georgina O. Miller

Theses and Dissertations

Parkinsonian rigidity is caused by the inability of the muscles to relax and extend properly, due to reduced dopamine levels and often begins on one side of the body before spreading contralaterally. The current standard for determining joint rigidity in a clinical setting is a test completed by the clinician based on the feel of the relaxed wrist and elbow joints as they are passively flexed and extended and a series of ordinal rating scales, the Movement Disorder Society’s – Unified Parkinson’s Disease Rating Scale (MDS-UPDRS), Hoehn and Yahr Scale (H&Y), and Parkinson’s Disease Questionnaire-39 (PDQ-39). These methods are used …

Dendrimer-Based Therapeutic Delivery Vehicle For The Treatment Of Ocular Diseases, Remy C. Cooper

Theses and Dissertations

The treatment of ocular diseases poses a significant challenge to drug delivery design, due to the eye’s complex anatomy, with a semi-permeable blood-ocular barrier and associated immune privilege. To address some of the delivery challenges, polycationic dendrimers are explored as vehicle for the treatment of posterior chamber disease. Dendrimers are a class of polymeric nanoparticles that are highly branched, multivalent and monodisperse, whose three-dimensional globular architecture has given them the nickname of “synthetic proteins”. Dendrimers are synthesized by reacting monomers in a step-wise fashion to produce generationally and radially increasing structures, with core, interior and surface chains that are highly …

Quantification And Modeling Of Bladder Biomechanics Mechanisms Linking Spontaneous Rhythmic Contractions And Dynamic Elasticity To Detrusor Overactivity, Zachary E. Cullingsworth

Theses and Dissertations

Overactive bladder (OAB) is a chronic condition affecting approximately 20% of adults in the United States. Detrusor overactivity (DO) is the presence of non-voiding contractions in the detrusor (bladder) muscle during filling and is present in some individuals with OAB. DO is currently identified visually during a urodynamics (UD) study involving pressure catheters and filling and voiding of the bladder to evaluate function. UD provides limited subtyping of DO, and an incomplete understanding of mechanisms contributing to OAB.

Aim 1 of this study was to develop objective tools to quantify, subgroup and better understand …

Influence Of Transdermal Current Flow In Tdcs-Induced Cutaneous Adverse Events, Niranjan Khadka

Dissertations and Theses

Significant contributors to the broad application of transcranial direct current stimulation (tDCS) are portability, ease-of-use, and tolerability; with adverse events limited to transient and mild cutaneous sensations (e.g. perception of burning, itching, and tingling) and erythema. However, the fundamental questions remain about the mechanism of transdermal current flow during transcranial electrical stimulation, including tDCS. Example of previously unexplained questions in tDCS include: 1) the relationship between tDCS-induced skin reddening (erythema) profile and local current density profile predicted by the model; 2) the source of burning sensation during tDCS and whether it is related to an actual skin heating; 3) the …

Characterization Of Bone Pathology In Sickle Cell Disease And Therapeutic Strategies, Mykel D. Green

Dissertations and Theses

Sickle cell disease (SCD) is a genetic hemoglobinopathy that has grown into a global health concern. While the advances in medical treatment and management of SCD during childhood have drastically improved the overall survival of children, the transition from pediatric to adult services is significantly inadequate in comparison. Life expectancies of patients with SCD in first world countries such as the United States are shortened to averages of 42 and 48 years for men and women, respectively. Despite the increasing number of people living with SCD, remarkably, few detailed studies have described the clinical course and complications of the disease …

On-Demand Electrically Induced Decomposition Of Thin-Film Nitrocellulose Membranes For Wearable Or Implantable Biosensor Systems, Benjamin M. Horstmann

Theses and Dissertations

Implantable or subcutaneous biosensors used for continuous health monitoring have a limited functional lifetime requiring frequent replacement and therefore may be highly discomforting to the patient and become costly. One possible solution to this problem is use of biosensor arrays where each individual reserve sensor can be activated on-demand when the previous one becomes inoperative due to biofouling or enzyme degradation. Each reserve biosensor in the array is housed in an individual Polydimethylsiloxane (PDMS) well and is protected from exposure to bodily fluids such as interstitial fluid ( ISF) by a thin-film nitrocellulose membrane. Controlled activation is achieved by decomposing …

The Impact Of Aging And Mechanical Injury On Alveolar Epithelial And Macrophage Responses In Acute Lung Injury And Inflammation, Michael S. Valentine

Theses and Dissertations

Patients with severe lung pathologies, such as Acute Respiratory Distress Syndrome (ARDS), often require mechanical ventilation as a clinical intervention; however, this procedure frequently exacerbates the original pulmonary issue and produces an exaggerated inflammatory response that potentially leads to sepsis, multisystem organ failure, and mortality. This acute lung injury (ALI) condition has been termed Ventilator-Induced Lung Injury (VILI). Alveolar overdistension, cyclic atelectasis, and biotrauma are the primary injury mechanisms in VILI that lead to the loss of alveolar barrier integrity and pulmonary inflammation. Stress and strains during mechanical ventilation are believed to initiate alveolar epithelial mechanotransduction signaling mechanisms that contribute …

Extracellular Matrix Nanoparticles Effects On The Lung In Vivo, Brittaney E. Ritchie

Theses and Dissertations

Acute respiratory distress syndrome (ARDS) is a life-threatening condition that causes diffuse alveolar damage and a loss of the extracellular matrix (ECM). This leads to pulmonary edema and lung function deterioration. Our lab has created decellularized porcine lung, electrosprayed ECM nanoparticles that have been previously shown to have pro-regenerative capabilities in vitro.

In this study, the ECM nanoparticle effects on young murine lungs were tested in vivo. An ECM nanoparticle suspension, previously used for the in vitro studies, was aerosolized intratracheally into the lungs using a microsprayer. 24 hours later, the lung mechanics, bronchoalveolar lavage fluid, and histology …

Automatic Hip Analysis Suite, Nathan J. Veilleux

Theses and Dissertations

Image recognition and computer vision are becoming increasingly useful for diagnostic and surgical planning purposes. Analyses of patient morphology can be performed much more quickly and reliably with algorithmic assistance. Traditional measurements of the hip involve visual inspection of patient radiographs or hand calculation with software assistance. In the most extreme cases, estimates of bone orientation are made via palpation of a patient’s hip. There is the possibility for significant improvements in reliability if measurements can be made in the absence of human interpretation. As many of these techniques require CT scans as a prerequisite, all of the necessary information …

Microfluidic System For Detectingmalaria-Infected Red Blood Cells Using Impedance Measurementcoupled With Electromagnetic Force, Prapapan Sonridhi

Chulalongkorn University Theses and Dissertations (Chula ETD)

Malaria is one of the most life-threatened diseases caused by Plasmodium parasite. Malaria is preventable and curable, mainly due to the factor of time and management of the spread. In other words, a rapid detection with high accuracy will contribute to more effective treatment process. In this research, we introduced the new technique implemented microfluidics, dealing with the manipulation of blood cells using magnetic force, and impedance measurement measuring the signal changes of electrical impedance between a couple of electrodes. According to the distinct magnetic properties of normal red blood cells and malaria-infected red blood cells, the experiment was designed …

A Framework For Heterologous Biosynthesis Of Natural Products In Mammalian Cells Via Polymer-Mediated Transfections, Logan Warriner

Theses and Dissertations--Chemical and Materials Engineering

With the promise to treat a multi-faceted list of serious inherited and acquired diseases, such as cancer, neurodegenerative and infectious diseases, and inherited genetic indications, gene therapy has continued to push the boundaries of traditional medicine since its earliest implementation. While much progress has been made, clinical success has largely remained elusive. Immunogenicity, difficulty producing commercially relevant quantities, and having a limited genetic payload still limits the ability of viruses to act as directed delivery agents for genetic material. As such, researchers have turned to cationic synthetic materials as a means of delivering nucleic acids, which can circumvent the immune …

Binder Saturation, Layer Thickness, Drying Time And Their Effects On Dimensional Tolerance And Density Of Cobalt Chrome - Tricalcium Phosphate Biocomposite, John Ruprecht

All Graduate Theses, Dissertations, and Other Capstone Projects

Traditional metals such as stainless steel, titanium and cobalt chrome are used in biomedical applications (implants, scaffolds, etc.) but suffer from issues such as osseointegration and compatibility with existing bone. One way to improve traditional biomaterials is to incorporate ceramics with these metals so that their mechanical properties can be similar to cortical bones. Tricalcium phosphate is such a ceramic with properties such that it can be used in the human body. This research explores the use of the Binder Jetting based additive manufacturing process to create a novel biocomposite made of cobalt chrome and tricalcium phosphate. Experiments were conducted …

Enhancement Of The Syncardia Total Artificial Heart For Pediatric Use, Margaret Clark, Madison Marks

Williams Honors College, Honors Research Projects

Pediatric patients with disorders and diseases of the heart have limited options with regards to implantable devices. Many of these implants are ventricular assist devices, which is not always suitable for a patient. Total artificial hearts (TAHs) have supported many adult patients until transplantation, and we believe that they could do the same for pediatric patients. SynCardia has the only Food and Drug Administration (FDA) approved TAH devices. Since SynCardia is the only company with FDA approved TAHs, we decided to modify the design of the SynCardia TAH for use in pediatric patients without compromising the function of the current …

All-Wheel-Ukraine, Sofiya Rakovska, Hannah Mcculloch, Andrey Garasimchuk, Ahmad Alsaihati

Williams Honors College, Honors Research Projects

We are working with a non-profit organization in Ukraine that provides wheelchairs/strollers to families of disables children who cannot afford them. Their current preferred solution is a baby stroller. The organization asked us to create a wheelchair that is cost efficient, light and collapsible to be used for children ages up to thirteen years old. We will be creating an alpha prototype wheelchair by modifying a basic wheelchair that we purchased. This modifications include adding a headrest that is adjustable and provides a sufficient support for children within the age group given to us and diverse levels of disabilities. We …