Medicine and Health Sciences Commons^™

Bio-Inspired Composite Hydrogels For Osteochondral Regenerative Engineering, Grant N. Gellert, Liangju Kuang, Chunhui Jiang, Nur P. Damayanti, Joseph Irudayaraj, Meng Deng

The Summer Undergraduate Research Fellowship (SURF) Symposium

Treatment of osteochondral defects encompassing injury or degeneration to both the articular cartilage as well as the underlying subchondral bone presents a significant medical challenge. Current treatment options including autografts and allografts suffer from limited availability and risk of immunogenicity, respectively. The long term goal of this work is to develop an integrated scaffold system for treatment of osteochondral defects via in situ regeneration of bone, cartilage and the bone-cartilage interface. Hydrogels composed of polymer networks swollen in water provide an attractive biomaterial platform for regeneration of cartilage. In the present study, we have developed a novel composite hydrogel consisting …

Development Of A Scalable Synthesis Of Hp-Β-Cd Pluronic Polyrotaxanes, Joseph L. Skulsky, Elizabeth A. Slepko, Bradley P. Loren, David H. Thompson

The Summer Undergraduate Research Fellowship (SURF) Symposium

Polyrotaxanes are polymers that have macrocycles threaded onto them, analogous to beads threaded onto a string. These materials are used for a variety of different biomedical applications.^1-3 The Thompson group has been developing 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) polyrotaxanes as therapeutics for the treatment of Niemann-Pick Type C (NPC) disease. NPC is a debilitating genetic disorder where cholesterol accumulates in the lysosomes of cells.⁴ Developing a scalable process is crucial for the advancement of these materials as NPC therapeutics. The goal of this project is to optimize the only protocol for the synthesis of HP-β-CD/Pluronic polyrotaxanes in order to develop a …

Plasminogen Activator Inhibitor-1 Inhibitors And Methods Of Use Thereof To Modulate Lipid Metabolism, Daniel A. Lawrence, Dudley Strickland, Jacqueline Cale, Enming Joe Su, Cory Emal, Mark Warnock

Patents

The invention relates to plasminogen activator-I (PAI-1) inhibitor compounds and uses thereof in the treatment of any disease or condition associated with elevated PAI-1. The invention includes, but is not limited to, the use of such compounds to modulate lipid metabolism and treat conditions associated with elevated PAI-1, cholesterol, or lipid levels.

Extended Followup Of A Cohort Of Chromium Production Workers, Herman Jones Gibb, Peter St. John Lees, Jing Wang, Keri O'Leary

Epidemiology Faculty Publications

Background

The current study evaluates the mortality of 2,354 workers first employed at a Baltimore chromate production plant between 1950 and 1974.

Methods

The National Death Index (NDI Plus) was used to determine vital status and cause of death. Cumulative chromium (VI) exposure and nasal and skin irritation were evaluated as risk factors for lung cancer mortality.

Results

There are 91,186 person-years of observation and 217 lung cancer deaths. Cumulative chromium (VI) exposure, nasal irritation, nasal perforation, nasal ulceration, and other forms of irritation (e.g., skin irritation) were associated with lung cancer mortality.

Conclusion

Cumulative chromium (VI) exposure was a …

Sexual Networks And Hiv Risk Among Black Men Who Have Sex With Men In 6 U.S. Cities, Hong-Van Tieu, Ting-Yuan Liu, Sophia Hussen, Matthew Connor, Lei Wang, Gregory Phillips Ii, + 11 More

Epidemiology Faculty Publications

Background

Sexual networks may place U.S. Black men who have sex with men (MSM) at increased HIV risk.

Methods

Self-reported egocentric sexual network data from the prior six months were collected from 1,349 community-recruited Black MSM in HPTN 061, a multi-component HIV prevention intervention feasibility study. Sexual network composition, size, and density (extent to which members are having sex with one another) were compared by self-reported HIV serostatus and age of the men. GEE models assessed network and other factors associated with having a Black sex partner, having a partner with at least two age category difference (age difference between …

Fusing Heterogeneous Data For Alzheimer's Disease Classification, P. S. Pillai, Tze-Yun Leong

Research Collection School Of Computing and Information Systems

In multi-view learning, multimodal representations of a real world object or situation are integrated to learn its overall picture. Feature sets from distinct data sources carry different, yet complementary, information which, if analysed together, usually yield better insights and more accurate results. Neuro-degenerative disorders such as dementia are characterized by changes in multiple biomarkers. This work combines the features from neuroimaging and cerebrospinal fluid studies to distinguish Alzheimer's disease patients from healthy subjects. We apply statistical data fusion techniques on 101 subjects from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. We examine whether fusion of biomarkers helps to improve diagnostic …

Synthesis And Flammability Testing Of Epoxy Functionalized Phosphorous-Based Flame Retardants, Vladimir Benin, Xuemei Cui, Alexander Morgan, Karl Seiwert

Chemistry Faculty Publications

Several potential new phosphorus-containing flame retardant molecules were evaluated for heat release reduction potential by incorporation of the molecules into a polyurethane, generated from methylene diphenyl diisocyanate and 1,3-propane diol. The heat release reduction potential of these substances was evaluated using the pyrolysis combustion flow calorimeter (PCFC). The polyurethanes were prepared in the presence of the potential flame retardants via solvent mixing and copolymerization methods to qualitatively evaluate their potential reactivity into the polyurethane prior to heat release testing. The functionality of the flame retardants was epoxide based that would potentially react with the diol during polyurethane synthesis. Flammability testing …

The Presence Of Clostridium Difficile On Environmental Surfaces In Healthcare Facilities Pre- And Post-Decontamination Of Patient Rooms, Theresa Trice

UNLV Theses, Dissertations, Professional Papers, and Capstones

Healthcare-associated infections (HAIs) are infections related to receiving medical care. HAIs are responsible for an excess of morbidity and mortality among hospitalized patients. Though most HAIs rates are on the decline, Clostridium difficile infection rates are at an all-time high, primarily due to the persistence of C. difficile spores in the environment. In the United States, Clostridium difficile-related mortality rates per million have increased from 5.7 in 1999 to 23.7 in 2004, with an estimated 26,642 deaths due to Clostridium difficile infections (CDIs). Clostridium difficile is transmitted via the fecal-oral route or aerosolized endospores, but it can also be transmitted …

Improving Attenuation Correction In Hybrid Positron Emission To Mography, Hua Asher Ai

Dissertations and Theses (Open Access)

Hybrid positron emission tomography imaging techniques such as PET/CT and PET/MR have undergone significant developments over the last two decades and have played increasingly more important roles both in research and in the clinic. A unique advantage PET has over other clinical imaging modalities is its capability of accurate quantification. However, as the most critical component of PET quantification, attenuation correction in hybrid PET systems is challenged in several different aspects, including the spatial- temporal mismatch between the PET emission images and the associated attenuation images provided by the complementary modality, and the difficulty in bone identification in the MR-based …

Feasibility Of Using Virtual Unenhanced Images To Replace Pre-Contrast Images In Multiphase Renal Ct Examinations, Dawn Olivia Popnoe

Dissertations and Theses (Open Access)

Multiphase renal CT exams are a commonly used imaging technique for the diagnosis of renal masses. The pre-contrast, or true unenhanced (TUE), image provides a baseline for enhancement measurements which is an important criteria used to characterize renal lesions, consequently it is crucial that CT numbers measured in TUE images be accurate. The purpose of this work is to assess the feasibility of replacing TUE with virtual unenhanced (VUE) images derived from DECT data in renal CT exams. Eliminating TUE image acquisition would reduce patient dose and increase patient throughput, improving clinical efficiency.

A retrospective study was conducted for 60 …

Quality Assurance Of Advanced Treatment Modalities Using Presage® Dosimeters, Ryan G. Lafratta

Dissertations and Theses (Open Access)

Computer-controlled therapy machines allow for increasingly complex plans, as there are more variables that can be tuned to produce the ideal result. This makes it increasingly difficult to assure the intended calculated dose is being delivered correctly using current techniques that are 2D-based because the resultant dose distributions can differ markedly in various sections of the target. A measurement of composite dose from the entire plan should be included in patient-specific IMRT QA. A volumetric dosimeter such as PRESAGE^® is able to provide a complete 3D measured dosimetry dataset with one treatment plan delivery. It was hypothesized that a …

Computational Modeling Of Rna-Small Molecule And Rna-Protein Interactions, Lu Chen

Dissertations and Theses (Open Access)

The past decade has witnessed an era of RNA biology; despite the considerable discoveries nowadays, challenges still remain when one aims to screen RNA-interacting small molecule or RNA-interacting protein. These challenges imply an immediate need for cost-efficient while predictive computational tools capable of generating insightful hypotheses to discover novel RNA-interacting small molecule or RNA-interacting protein. Thus, we implemented novel computational models in this dissertation to predict RNA-ligand interactions (Chapter 1) and RNA-protein interactions (Chapter 2).

Targeting RNA has not garnered comparable interest as protein, and is restricted by lack of computational tools for structure-based drug design. To test the potential …

Quantification Of Imrt Severity Scores For Improvement Of Fmea Results, Jacqueline T. Faught

Dissertations and Theses (Open Access)

Accurate delivery of intensity modulation radiation therapy (IMRT) requires perfect execution of a long, complicated chain of events; failure of any component of this process may contribute to dose delivery errors, compromising treatment quality and, more importantly, patient safety. Prospective, process-wide risk mitigation techniques are becoming more prevalent in radiotherapy to establish comprehensive quality management (QM) programs, such as failure modes and effects analysis (FMEA). The subjective nature of the ordinal scores used for FMEA leads questionable reliability and validity of the results. Additionally, physics components are commonly grouped together, leaving out valuable details important to physics QM. While the …

Mobile Cloud Computing Based Non Rigid Registration For Image Guided Surgery, Arun Brahmavar Vishwanatha

Computer Science Theses & Dissertations

In this thesis we present the design and implementation of a Mobile Cloud computing platform for non-rigid registration required in Image Guided Surgery (MCIGS). MCIGS contributes in flexible, portable and accurate alignment of pre-operative brain data with intra-operative MRI, for image guided diagnosis and therapy and endoscopic skull base surgery. Improved precision of image guided therapy and specifically neurosurgery procedures is known to result in the improved prognosis for brain tumor patients. MCI GS system is tested with Physics Based Non-Rigid Registration method form ITK. Our preliminary results for brain images indicate that the proposed system over Wi-Fi can be …

Degradation Science: Mesoscopic Evolution And Temporal Analytics Of Photovoltaic Energy Materials, Roger H. French, Rudolf Podgornik, Timothy J. Peshek, Laura S. Bruckman, Yifan Xu, Nicholas R. Wheeler, Abdulkerim Gok, Yang Hu, Mohammad A. Hossain, Devin A. Gordon, Pei Zhao, Jiayang Sun, Guo-Qiang Zhang

Faculty Scholarship

Based on recent advances in nanoscience, data science and the availability of massive real-world datastreams, the mesoscopic evolution of mesoscopic energy materials can now be more fully studied. The temporal evolution is vastly complex in time and length scales and is fundamentally challenging to scientific understanding of degradation mechanisms and pathways responsible for energy materials evolution over lifetime. We propose a paradigm shift towards mesoscopic evolution modeling, based on physical and statistical models, that would integrate laboratory studies and real-world massive datastreams into a stress/mechanism/response framework with predictive capabilities. These epidemiological studies encompass the variability in properties that affect performance …

The Physics Of Human Performance: An Ideal Lab, William B. Laing Iii, Harold Mayer

Faculty Works

Physics lab goes to the gymnasium, where students calculate the mechanical power required to walk on an inclined treadmill in watts and convert to units power used to measure human performance: VO2, and METs. Students learn how to use two linear regression models: the ACSM "walking equation" to estimate the actual power expenditure of walking and the Rockport 1 mile test to estimate their own VO2max. Students use models to prescribe exercise parameters for themselves and for two cases. The IDEAL lab collaboration is developing labs that are open, applied to life, and rigorously quantitative.

Quantifying Measurement Error In Digital Instruments, William B. Laing Iii, Sean Bryant

Faculty Works

A first lab experiment clearly illustrates that a glucose meter is actually an excellent source of both random and systematic error, much to the surprise to students and physicians alike. A histogram is constructed and the utility of the standard deviation and standard error to quantify the uncertainty in each measurement and in the mean value, respectively, is demonstrated. From the first lab on, students are challenged to express and interpret confidence intervals in order to form quantitative conclusions. Assessments reveal that many students find this to be surprisingly challenging.

Caffeine Consumption Contributes To Skin Intrinsic Fluorescence In Type 1 Diabetes., Karen M Eny, Trevor J Orchard, Rachel Grace Miller, John Maynard, Denis M Grant, Tina Costacou, Patricia A. Cleary, Barbara H Braffett, Andrew D Paterson, Dcct/Edic Research Group

GW Biostatistics Center

Background: A variant (rs1495741) in the gene for the N-acetyltransferase 2 (NAT2) protein is associated with skin intrinsic fluorescence (SIF), a noninvasive measure of advanced glycation end products and other fluorophores in the skin. Because NAT2 is involved in caffeine metabolism, we aimed to determine whether caffeine consumption is associated with SIF and whether rs1495741 is associated with SIF independently of caffeine.

Materials and Methods: SIF was measured in 1,181 participants with type 1 diabetes from the Epidemiology of Diabetes Interventions and Complications study. Two measures of SIF were used: SIF1, using a 375-nm excitation light-emitting diode (LED), and …

Inferring Interaction Type In Gene Regulatory Networks Using Co-Expression Data, Pegah Khosravi, Vahid H. Gazestani, Leila Pirhaji, Brian Law, Mehdi Sadeghi, Bahram Goliaei, Gary D. Bader

Publications and Research

Background

Knowledge of interaction types in biological networks is important for understanding the functional organization of the cell. Currently information-based approaches are widely used for inferring gene regulatory interactions from genomics data, such as gene expression profiles; however, these approaches do not provide evidence about the regulation type (positive or negative sign) of the interaction.

Results

This paper describes a novel algorithm, “Signing of Regulatory Networks” (SIREN), which can infer the regulatory type of interactions in a known gene regulatory network (GRN) given corresponding genome-wide gene expression data. To assess our new approach, we applied it to three different benchmark …

Nitrate And Nitrite Ingestion And Risk Of Ovarian Cancer Among Postmenopausal Women In Iowa, Maki Inoue-Choi, Rena R. Jones, Kristin E. Anderson, Kenneth P. Cantor, James R. Cerhan, Stuart Krasner, Kimberly Robien, Peter J. Weyer, Mary H. Ward

Epidemiology Faculty Publications

Nitrate and nitrite are precursors in the endogenous formation of N-nitroso compounds (NOC), potential human carcinogens. We evaluated the association of nitrate and nitrite ingestion with postmenopausal ovarian cancer risk in the Iowa Women's Health Study. Among 28,555 postmenopausal women, we identified 315 incident epithelial ovarian cancers from 1986 to 2010. Dietary nitrate and nitrite intakes were assessed at baseline using food frequency questionnaire data. Drinking water source at home was obtained in a 1989 follow-up survey. Nitrate-nitrogen (NO₃-N) and total trihalomethane (TTHM) levels for Iowa public water utilities were linked to residences and average levels were …

Improving Patient Flow With Data-Driven Patient Prioritization Method In The Emergency Department, Kar Way Tan, Sean Shao Wei Lam

Research Collection School Of Computing and Information Systems

We aim to improve the length-of-stay (LOS) of patients in the Emergency Department (ED) ambulatory care area. We propose the use of real-time computerized physician order entry data and ED patient flow management system to estimate the consultation time of patients re-entering the queue to consult a doctor again after receiving treatment or results of tests. The estimation allows decision-makers to apply dynamic prioritization strategies that help the ED to identify patients who can complete their ED treatment process quickly, freeing up resources in the ED and lowering overall LOS.

Size And Power Of Tests Of Hypotheses On Survival Parameters From The Lindley Distribution With Covariates, Macaulay Okwuokenye, Karl E. Peace

Biostatistics: Faculty Publications

The Lindley model is considered as an alternative model facilitating analyses of time-to-event data with covariates. Covariate information is incorporated using the Cox’s proportional hazard model with the Lindley model at the timedependent component. Simulation studies are performed to assess the size and power of tests of hypotheses on parameters arising from maximum likelihood estimators of parameters in the Lindley model. Results are contrasted with that arising from Cox’s partial maximum likelihood estimator. The Linley model is used to analyze a publicly available data set and contrasted with other models.

Joint Modeling Of Treatment Effect On Time-To-Event Endpoint And Safety Covariates In Control Clinical Trial Data Analysis, Kao-Tai Tsai, Karl E. Peace

Biostatistics: Faculty Publications

It is a common practice to perform a separate analysis of efficacy and safety data from clinical trials to estimate the benefit and risk aspects of a particular treatment regimen. However, by doing so, one is likely to miss the complete picture of the treatment effect given that these data are generated from the same study subjects and therefore most likely will be correlated. Therefore, it is desirable to analyze these data jointly to obtain a more complete profile of the treatment regimen. A substantial number of statistical methodologies have been proposed in the last decade to model the time-to-event …

Modification Of Traffic-Related Respiratory Response By Asthma Control In A Population Of Car Commuters, Maria C. Mirabelli, Rachel Golan, Roby Greenwald, Amit U. Raysoni, Fernando Holguin, Priya Kewada, Andrea Winquist, W Dana Flanders, Jeremy A. Sarnat

School of Earth, Environmental, & Marine Sciences Faculty Publications

Background: Effects of traffic-related exposures on respiratory health are well documented, but little information is available about whether asthma control influences individual susceptibility. We analyzed data from the Atlanta Commuter Exposure study to evaluate modification of associations between rush-hour commuting, in- vehicle air pollution, and selected respiratory health outcomes by asthma control status.

Methods: Between 2009 and 2011, 39 adults participated in Atlanta Commuter Exposure, and each conducted two scripted rush-hour highway commutes. In-vehicle particulate components were measured during all commutes. Among adults with asthma, we evaluated asthma control by questionnaire and spirometry. Exhaled nitric oxide, forced expiratory volume in …

Modeling Of Humoral Immune Response To Repeated Influenza A Virus Infections, Abbiana Arenas, Safiyah Muhammad, Ly Nguyen, Samita Andreansky, Evan Haskell

Mathematics Faculty Proceedings, Presentations, Speeches, Lectures

Seasonal infections by Influenza A virus (IAV) causes hundreds of thousands of deaths worldwide each year, with most individuals being infected multiple times throughout their lifetimes. The relative impact of the components of the host immune system in controlling the severity and duration of repeated challenges from an IAV infection remains unclear. In particular, the differential contribution of the humoral immune response in primary and secondary challenges from IAV are relatively little explored. We develop a parsimonious mathematical model of the humoral immune response to IAV infection with biologically meaningful and identifiable parameters. We show the relative sensitivity of the …

Comparison Of Robotics, Functional Electrical Stimulation, And Motor Learning Methods For Treatment Of Persistent Upper Extremity Dysfunction After Stroke: A Randomized Controlled Trial, Jessica Mccabe, Michelle Monkiewicz, John P. Holcomb, Svetlana Pundik, Janis J. Daly

Mathematics and Statistics Faculty Publications

Objective

To compare response to upper-limb treatment using robotics plus motor learning (ML) versus functional electrical stimulation (FES) plus ML versus ML alone, according to a measure of complex functional everyday tasks for chronic, severely impaired stroke survivors.

Design

Single-blind, randomized trial.

Setting

Medical center.

Participants

Enrolled subjects (N=39) were >1 year post single stroke (attrition rate=10%; 35 completed the study).

Interventions

All groups received treatment 5d/wk for 5h/d (60 sessions), with unique treatment as follows: ML alone (n=11) (5h/d partial- and whole-task practice of complex functional tasks), robotics plus ML (n=12) (3.5h/d of ML and 1.5h/d of shoulder/elbow robotics), …

Iarc Monographs: 40 Years Of Evaluating Carcinogenic Hazards To Humans, Neil E. Pearce, Aaron Blair, Paolo Vineis, Wolfgang Ahrens, Aage Andersom, Josep M. Anto, Bruce K. Armstrong, Andrea A. Baccarelli, Frederick A. Beland, Amy Berrington, Pier Alberto Bertazzi, Linda S. Birnbaum, Ross C. Brownson, John R. Bucher, Kenneth P. Cantor, Elisabeth Cardis, John W. Cherrie, David C. Christiani, Pierluigi Cocco, David Coggon, Pietro Comba, Paul A. Demers, John M. Dement, Jeroen Douwes, Ellen A. Eisen, Lawrence S. Engel, Richard A. Fenske, Lora E. Fleming, Tony Fletcher, Elizabeth Fontham, Francesco Forastiere, Rainer Frentzel-Beyme, Lin Fritschi, Michel Gerin, Marcel Goldberg, Philippe Grandjean, Tom K. Grimsrud, Per Gustavsson, Andy Haines, Patricia Hartge, Johnni Hansen, Michael Hauptmann, Dick Heederik, Kari Hemminki, Denis Hemon, Irva Hertz-Picciotto, Jane A. Hoppin, James Huff, Bengt Jarvholm, Daehee Kang, Margaret R. Karagas

Dartmouth Scholarship

Background: Recently, the International Agency for Research on Cancer (IARC) Programme for the Evaluation of Carcinogenic Risks to Humans has been criticized for several of its evaluations, and also for the approach used to perform these evaluations. Some critics have claimed that failures of IARC Working Groups to recognize study weaknesses and biases of Working Group members have led to inappropriate classification of a number of agents as carcinogenic to humans.

Objectives: The authors of this Commentary are scientists from various disciplines relevant to the identification and hazard evaluation of human carcinogens. We examined criticisms of the IARC classification process …

The Biological Consequences Of Kaolin Geophagia, Deloris Alexander, Desire Richardson, Lakisha Odom, Kara Cromwell, Dejuana Grant, Micoya Myers, Eddy Cadet, Hamid Mahama, Vijaya Rangari, Ralphenia Pace, Ramble Ankumah, Kokoasse Kpomblekou-A, Curtis Fluker

Professional Agricultural Workers Journal

Abstract

Kaolin geophagia is associated with the relief of gastrointestinal distress, but it may also cause adverse health effects on the body. This study was designed to: assess kaolin composition; test if 129SvEv mice would consume kaolin and determine the consequences of consumption; and assess rotational stress modulation of consumption. Thirteen kaolin samples were purchased from Alabama and Georgia stores. Chemical and physical properties were characterized for each sample using a Munsell chart, pH meter, Energy Dispersive Spectroscopy, Transmission Electron Microscopy, Visible Near-InfraRed Spectra, and Inductively Coupled Plasma-Optical Emission Spectrometry. Kaolin was then given to mice as food supplements and …

The Relationship Between Self-Determination And Client Outcomes Among The Homeless, Samuel M. Hanna

Electronic Theses, Projects, and Dissertations

This paper has attempted to determine if there is a significant relationship between self-determination and client outcomes among the homeless. The study has been based upon the conceptual framework set forth in Self-Determination Theory. The purpose of the study was to explore the relationship between self-determination and client outcomes among the homeless. Using a data collection instrument, based on empirically validated instrumentation, clients from several homeless service providers in the City of San Bernardino were assessed for the level of self-determination and autonomy support they experience within these agencies. Outcome measures included such things as whether the client was going …

Examining The Toxicity, Exposure, And Regulatory Approach To Potential Human Health Risks Of The Algal Toxin Domoic Acid, Thomas H. Angus

Graduate Doctoral Dissertations

Domoic acid is a neurotoxin produced by the marine diatom genus Pseudo-nitzschia and causes cell death primarily in the area of the brain responsible for long-term memory. The resulting severe illness has been termed amnesic shellfish poisoning. Domoic acid accumulates in shellfish and planktivorous fish that consume Pseudo-nitzschia, resulting in exposure to humans through consumption of planktivorous seafood. A regulatory standard in seafood was developed shortly after its discovery in 1987 to protect against acute effects. This regulatory standard has not been revised despite significant recent data in the scientific literature.

This dissertation is divided into four sections: (1) …