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An antiviral peptide targeting influenza and parainfluenzaBacon, Matthew Neil January 2014 (has links)
Respiratory virus infections, such as those caused by influenza, parainfluenza and respiratory syncytial virus (hRSV), continue to be a major cause of morbidity and mortality in both the developed and developing world. Currently, the main means of control of influenza virus infection is vaccination, which requires advanced knowledge of the strain that will be prevalent each year. Alternative strategies involve the use of anti-viral drugs, which function primarily as a prophylactic. Currently, there are five main drugs available against influenza, the adamantanes (amantadine and rimantidine) and the neuraminidase inhibitors (oseltamivir, zanamivir and peramivir). However, major problems exist with antivirals, notably the development of drug resistance. This means that new drugs are urgently required that also satisfy the need to intervene at specific phases of the infection. This thesis describes the development of a peptide with anti-influenza virus activity (Flupep), from which a library of closely related peptides were synthesised, with the aim of optimising antiviral efficacy. Peptides were tested in vitro using a plaque reduction assay on cultured cell lines, Vero and MDCK for parainfluenza and influenza respectively. Two strains of influenza and two of parainfluenza were used, covering the main subtypes that infect humans: Influenza A, Influenza B, PIV2 and PIV3. The plaque assay involved mixing a fixed dose of virus with dilutions of peptide and infecting the cultured cells, followed by incubation for between 3 and 14 days. The cells were then fixed, stained and plaques counted as a measure of viral infectivity. Previous work had shown that Flupep both interacts with haemagglutinin and is an antagonist of inflammatory cytokines. As a possible explanation for antiviral activity, binding affinity of the peptide to haemagglutinin was measured utilising enzyme linked immunosorbent assays. However, significant binding was not detected, suggesting non-specific binding and anti-inflammatory potential are more important routes for antiviral activity. Peptides which demonstrated greater than 90% plaque knockdown in vitro were evaluated in vivo. Anaesthetised mice were infected with influenza A and administered with the peptide concurrently. Following infection, body weights were measured daily and clinical signs, such as shortness of breath, quality of coat and posture, were monitored as indicators of overall health. Most mice were culled on the seventh day post-infection and lung viral titres were determined using a plaque assay. Two peptides were identified with high efficacy against influenza. These peptides, when used in vivo, improved clinical signs of and dramatically reduced levels of infectious virus in the lungs by 7 days post infection. The peptide with highest efficacy was PEGylated and subsequently shown to possess therapeutic potential. Intranasal administration of the PEG-peptide to anaesthetised mice, on the two days subsequent to infection with influenza A, revealed a 17-fold fall in lung viral titres by the fourth day post-infection. Overall, Flupep demonstrates great potential as a future therapeutic agent for treatment of Influenza and potentially Parainfluenza.
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An Evidence-Based Strategy to Improve Influenza Vaccination Rates Among Registered Nurses in HospitalsSpoltore, Terri Lynn 01 January 2016 (has links)
Seasonal influenza, or the flu, impacts over 3 million people each year. Within the health sector, nosocomial infection and absenteeism are frequently associated with the flu. The Centers for Disease Control and Prevention (CDC) recommend flu vaccination for all eligible individuals, especially health care workers (HCWs). Interventions associated with increased HCW vaccination include educational programs and occupational health campaigns to address misconceptions regarding vaccine safety and efficacy. This project evaluated the impact of a voluntary, web-based education module to encourage registered nurse (RN) vaccination. The logic and health belief models served as the theoretical frameworks. In a nonequivalent group design, an educational program addressing evidence-based barriers to vaccination was delivered at 1 acute-care hospital and was not delivered at a comparison hospital within the health system. A total of 192 surveys (116 at intervention facility) were returned over 3 weeks. Statistically significant differences (x2 = 7.210, p = 0.007) were found for RNs who accepted influenza vaccination after education when compared to the RNs not receiving education. The 15% higher vaccination rate for RNs receiving education (91.1% vs. 76.1%) translates into more than 100 additional vaccinated RNs if applied across both hospitals. This project found that a simple but tailored web-based educational program is effective in converting RNs to vaccination acceptance. Increased vaccination produces societal change by reducing nosocomial and community influenza transmission. Reduced influenza infection improves community health as well as patient safety. Future work should address community-wide HCW education initiatives and evaluate their impact on quality and financial indicators at the hospital and community levels.
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Correlates of Influenza Vaccination Uptake Among Older AdultsHilliman, Cheryl 01 January 2016 (has links)
Seasonal influenza is associated with signiï¬?cant morbidity and mortality among older adults, aged 65 and older. Since vaccination is the single most effective preventive measure against seasonal influenza, clinicians and senior citizen center administrators need a better understanding of the perceptions of older adults concerning the reason for poor influenza vaccine uptake. The purpose of this study was to identify perceived factors that may be associated with poor influenza vaccination uptake among older adults. The health belief model (HBM) guided the study. The research questions examined perceptions predicting the odds of influenza vaccination uptake among older adults. This quantitative cross-sectional study consisted of administration of a newly developed 33-item questionnaire to a convenience sample of 147 older adult participants. A 2-week reliability test-retest on 50 participants indicated the instrument had moderate internal consistency (α -?¥ 0.7). Paired-sample t tests were not significant (p > .05), indicating that participants provided reliable responses across time. Ordinal regression analysis indicated that all HBM constructs were significantly associated (susceptibility, barriers, benefits, cues to action, and self-efficacy p = .000; severity p = .002) with frequency of influenza disease and recency of influenza vaccine uptake within 1 year. The social change implications from this study may help to improve vaccination uptake among older adults by providing senior public health decision makers and direct care clinicians with informed knowledge on perceptions and barriers that may play a role in influenza vaccination decision-making among older adults.
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Spatial and temporal patterns in the spread of influenza A and B viruses in the United States during the 2016-17 influenza seasonKoss, Jeffrey David 01 May 2018 (has links)
Influenza is a respiratory virus that causes significant morbidity and mortality throughout the world every year. Seasonal epidemics of influenza occur in the late fall and winter in the United States annually, but there are variations in its timing from year to year. Further, although the timing of epidemic waves in the United States are similar, there is variation between different populations. It is not well understood why these differences exist. Understanding the spatial and temporal variation in the timing of influenza is important because it shapes our understanding of preventive actions that can be taken to limit the spread of the virus.
Past studies that have examined the timing of influenza have been limited by the fact that they have used influenza-like illness (ILI) as an indicator of influenza. ILI has traditionally been the conventional indicator of influenza because the illness does not present unique symptoms. As such, spatial and temporal variation in the relative timing of influenza A, influenza B, and ILI have not been investigated extensively. Additionally, there has been concern raised about implications of the imprecise nature of ILI in treating patients that it is believed may have influenza.
This study addressed this gap and concern by utilizing influenza-specific data from clinics and hospitals throughout the United States to evaluate spatial variation in the timing of influenza across the United States in the 2016-17 influenza season. Results from influenza rapid tests were aggregated by urban area as a means of evaluating associations between epidemic timing and independent variables in different locations. The timing of influenza A and B epidemics was tested for spatial autocorrelation and incorporated in regression models to identify potential relationships between epidemic timing and several variables (including dew point, temperature, population, population density, and cumulative seasonal vaccination rates). Forward stepwise regression was then conducted to identify a set of variables that may be best suited to explain the timing of these milestones, and spatial lag regression was conducted to account for spatial autocorrelation in these variables.
This analysis indicated that higher average dew point and temperature and greater population and population density were both associated with earlier epidemic beginnings and later epidemic endings, while higher cumulative seasonal vaccination rates were associated with earlier epidemic endings for influenza A and B. Forward stepwise regression yielded models that generally differed for each epidemic milestone and type of influenza, indicating that different sets of variables might be best suited to explain different milestones of epidemics. Spatial lag regression improved model fit for the forward stepwise models for which there was residual spatial autocorrelation.
This is one of the first studies to evaluate the timing of different points within an epidemic. The techniques I used to study timing are well-suited for the study of future epidemics of infectious diseases, including influenza, that seek to identify and clarify potential associations between independent variables and epidemic timing.
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Molecular detection and identification of avian influenza viruses by cDNA microarrayMaughan, Michele Nancy. January 2007 (has links)
Thesis (M.S.)--University of Delaware, 2006. / Principal faculty advisor: Calvin L. Keeler, Dept. of Animal & Food Sciences. Includes bibliographical references.
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Antiviral and cytokine responses of human mast cells to influenza A virus infectionMarcet, Candy 11 1900 (has links)
Mast cells are immune cells important in innate immunity. Besides their role in asthma and allergies, mast cells are critical effector cells against various pathogens. Mast cells are established to be protective against bacterial infections, but little is known about their functions in viral infections.
Mast cells are abundant in the lungs where influenza A virus (FluA) enter the host. We measured mRNA transcription, protein translation, and synthesis of new viral particles in FluA-treated mast cells. While expression of FluA mRNA and proteins followed similar time courses in both mast cells and epithelial cells, mast cells released a near absence of FluA.
We also studied mast cell cytokine release in response to FluA and other viral-associated stimuli such as TLR ligands and type I interferons. Mast cells released the cytokines IL-6 and TGF-, and chemokines CXCL8 and CCL5 in response to various viral stimuli. However, different stimuli were capable of inducing release of different mediator subsets, demonstrating the specificity of mast cell responses.
Since FluA infection of mast cells produce little new FluA virions, we investigated whether FluA induces expression of antiviral proteins in mast cells. FluA treatment resulted in mast cell expression of antiviral proteins, namely myxovirus resistance protein A, protein kinase R, interferon stimulated gene 15, viral stress inducible protein 56, and endothelial nitric oxide synthase.
Next, we performed co-culture experiments using FluA-infected epithelial cells with or without the addition of mast cells. Our results showed that mast cells in co-culture inhibited the expression of the viral hemagglutinin protein in FluA-infected epithelial cells. Also, preliminary results showed that addition of mast cells protected epithelial cells from FluA infection by limiting the release of FluA particles and reducing epithelial cell death.
Our discovery that mast cells produce little virus and express antiviral proteins suggest that mast cells have antiviral mechanisms to restrict FluA infection. This concept was further supported by evidence that mast cells are protective against FluA infection in epithelial cells. This research provides a better understanding of mast cells in innate immunity and may reveal unique antiviral mechanisms valuable in the development of antiviral therapeutics.
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The Quantity and Structural Quality of SP-A and SP-D Present in the Airways of Influenza-infected PatientsBresner, Lauren Alison 15 December 2010 (has links)
Influenza A virus (IAV) is a major cause of morbidity and mortality worldwide. Surfactant proteins A and D (SP-A and SP-D) are important lung innate immune proteins and have been shown in vitro and in mice to both neutralize and enhance the clearance of various IAV strains. In this study we hypothesized that SP-A and SP-D levels will be lower in human bronchoalveolar lavage (BAL) fluids from patients who have tested positive for influenza, as well as bacterial or fungal pathogens compared to controls. We have found that patients who have detectable IAV, bacteria or fungus have lower levels of SP-A and SP-D as detected by western blot analysis and enzyme-linked immunosorbent assay (ELISA) when compared to controls. Also, we found minor differences in the oligomerization and no differences in the glycosylation of SP-A and SP-D among BALs that detected the proteins on a Western blot.
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The Quantity and Structural Quality of SP-A and SP-D Present in the Airways of Influenza-infected PatientsBresner, Lauren Alison 15 December 2010 (has links)
Influenza A virus (IAV) is a major cause of morbidity and mortality worldwide. Surfactant proteins A and D (SP-A and SP-D) are important lung innate immune proteins and have been shown in vitro and in mice to both neutralize and enhance the clearance of various IAV strains. In this study we hypothesized that SP-A and SP-D levels will be lower in human bronchoalveolar lavage (BAL) fluids from patients who have tested positive for influenza, as well as bacterial or fungal pathogens compared to controls. We have found that patients who have detectable IAV, bacteria or fungus have lower levels of SP-A and SP-D as detected by western blot analysis and enzyme-linked immunosorbent assay (ELISA) when compared to controls. Also, we found minor differences in the oligomerization and no differences in the glycosylation of SP-A and SP-D among BALs that detected the proteins on a Western blot.
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Construction of Distributed Method for Analyzing a Large Number of Sequence Data: Using Influenza A Virus Protein Sequences as ExamplesTu, Guo-Hua 01 November 2010 (has links)
Abstract
Analyzing the eight genomic protein segments of influenza A virus could provide a better understanding of this specific virus. Along with the progress of computer technology, numerous influenza A virus protein sequences were available in various internet data banks. However, analyzing a large number of protein sequences is a cumbersome work. Thus it is necessary to develop new tools with algorithmic method. This study used distributed method to develop a protein sequence clustering analysis software by JAVA programming language. The software could split a large number of protein sequences downloaded from NCBI into several files. Because of these individual files were calculated at the same time, therefore it could reduce the time in process of comparison and analysis. Finally, we used PRIMER 5 program to analyze these individual files and produce similarity analysis chart diagrams of MDS and UPGMA. In The similarity analysis chart diagrams indicated high homology in genomic protein segments of influenza A virus from year 1997 to 2006. The analysis also showed the genomic protein segments of influenza A virus are similar in Asia countries. However, the similarity between Asian countries and China is not significant. From analyzing the hosts, the genomic protein segments of influenza A virus are highly similar in species such like birds, chickens, ducks and pigs. Therefore, our data strongly support that the possibility of influenza A viruses can cross species to infect humans.
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Level of Preparedness for Pandemic Influenza among Key Leaders in Brazos CountyKaster, Elizabeth 2010 December 1900 (has links)
With the outbreak of the 2009 pandemic influenza A (H1N1) comes the need to evaluate the preparedness level of government entities that had preparedness plans. This study looks at the preparedness level for pandemic influenza among key leaders in Brazos County according to their Brazos County Pandemic Influenza Preparedness Plan. Ten key leaders were recruited to participate in interviews. Interviews were transcribed and analyzed for salient themes. Main themes that emerged from interviews were categorized into vaccinations, communication, logistical issues, and the need for evaluations and feedback. Recommendations for increasing preparedness include addressing contingency plans, increasing education through public health efforts, addressing biosecurity, increasing use of technology, and increasing funding and research.
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