Dissertations / Theses on the topic 'Viral testing'

Respiratory viral testing in hospitalized patients is thought to improve quality of care by reducing the use of diagnostic tests, guiding infection control precautions, and rationalizing antimicrobial therapies. Few small published studies have tested these assumptions, and have demonstrated conflicting results. We conducted a retrospective cohort study of 24,567 hospitalizations using administrative data to determine the associations between viral testing, patient outcomes, and process of care. Viral testing was not associated with improved mortality or length of stay in hospital, and resulted in more resource utilization. The test result did not influence the duration of isolation precautions. This implies that health care providers may not use the results of testing in making management decisions, or in guiding the use of isolation precautions. This study provides the foundation for further scientific evaluation and reform of our current respiratory infection control policy.

Pandemic outbreaks are unpredictable as to their virus strain, transmissibility, and impact on our quality of life. Hence, the decision support models for mitigation of pandemic outbreaks must be user-friendly and operational, and also incorporate valid estimates of disease transmissibility and severity. This dissertation research is aimed at 1) reviewing the existing pandemic simulation models to identify their implementation gaps with regard to usability and operability, and suggesting research remedies, 2) increasing operability of simulation models by calibrating them via an epidemiological model that estimates infection probabilities using viral shedding profiles of concurrent pandemic and seasonal influenza, and 3) developing a testing strategy for the state laboratories, with their limited capacities, to improve their ability to estimate evolving transmissibility parameters. Our review of literature (Aim 1) indicates the need to continue model enhancements in critical areas including updating of epidemiological data during a pandemic, smooth handling of large demographical databases, incorporation of a broader spectrum of social-behavioral aspects, and improvement of computational efficiency and accessibility. As regards the ease of calibration (Aim 2), we demonstrate that the simulation models, when driven by the infection probabilities obtained from our epidemiological model, accurately reproduce the disease transmissibility parameters. Assuming the availability of sufficient disease reporting infrastructure and strong compliance by both infected population and healthcare providers, our testing strategy (Aim 3) adequately supports characterization of real-time epidemiological parameters. Future research on this topic will be aimed at integrating the laboratory testing strategy with our modeling and simulation approach to develop dynamic mitigation strategies for pandemic outbreaks.

The high rates of depression and suicide among older adults have given rise to research which aims to identify factors that protect older people from mental illness. Recently, Bailey and McLaren (2005) developed and tested a model which investigated the relationships between engagement in various leisure activities performed alone or with others, sense of belonging, depression, and suicidal ideation. The present study examined an extended version of the mental health model, incorporating the additional variables of perceived freedom in leisure and physical health status. A sample of Australian males and females (N = 379) aged 65 years and over (M age = 77.23, SD = 7.48) completed the Perceived Freedom in Leisure Questionnaire, the Yale Physical Activity Survey,the Duke Health Profile, the Sense of Belonging Instrument, the Centre for Epidemiological Studies-Depressive Scale, and the Suicide Subscale of the General Health Questionnaire. Results indicated that the model was invariant for gender, and accounted for 56% of the variance in suicidal ideation. The model indicated that physical health had direct relationships with each variable in the model. Perceived freedom in leisure predicted engagement in physical activity, sense of belonging-antecedent, and depression, whereas sense of belonging psychological state predicted depression and suicidal ideation. Results suggest that interventions aimed at improving older adults’ perceptions of freedom and personal choice with regard to their leisure experiences, maintaining optimal health, and increasing opportunities to foster feelings of belonging and relatedness with others, should protect against the development of mental ill health.
Doctor of Psychology (Clinical)

The high rates of depression and suicide among older adults have given rise to research which aims to identify factors that protect older people from mental illness. Recently, Bailey and McLaren (2005) developed and tested a model which investigated the relationships between engagement in various leisure activities performed alone or with others, sense of belonging, depression, and suicidal ideation. The present study examined an extended version of the mental health model, incorporating the additional variables of perceived freedom in leisure and physical health status. A sample of Australian males and females (N = 379) aged 65 years and over (M age = 77.23, SD = 7.48) completed the Perceived Freedom in Leisure Questionnaire, the Yale Physical Activity Survey,the Duke Health Profile, the Sense of Belonging Instrument, the Centre for Epidemiological Studies-Depressive Scale, and the Suicide Subscale of the General Health Questionnaire. Results indicated that the model was invariant for gender, and accounted for 56% of the variance in suicidal ideation. The model indicated that physical health had direct relationships with each variable in the model. Perceived freedom in leisure predicted engagement in physical activity, sense of belonging-antecedent, and depression, whereas sense of belonging psychological state predicted depression and suicidal ideation. Results suggest that interventions aimed at improving older adults’ perceptions of freedom and personal choice with regard to their leisure experiences, maintaining optimal health, and increasing opportunities to foster feelings of belonging and relatedness with others, should protect against the development of mental ill health.
Doctor of Psychology (Clinical)

Desinfektionsmittel sind ein elementarer Bestandteil der Tierseuchenbekämpfung und damit auch der Lebensmittelsicherheit. Die Prüfung chemischer Desinfektionsmittel ist Voraussetzung für deren zuverlässige Wirksamkeit und zielgerichteten Einsatz. In Deutschland geschieht dies nach den Richtlinien der Deutschen Veterinärmedizinischen Gesellschaft e.V. (DVG). Seit der ersten Fassung sind die Richtlinien einem ständigen Anpassungsprozess unterworfen. Im Zuge der europäischen Harmonisierung gilt es nun, sich gesamteuropäischen Richtlinien, verfasst durch das europäische Komitee für Normung (Comité Européen de Normalisation) (CEN) anzupassen. Das Thema dieser Arbeit entwickelte sich im Kontext der derzeitigen Diskussion über Verbesserungsvorschläge zu den bestehenden Richtlinien und deren Anpassung an die europäischen Normen. Es wurden je zwei Testviren für die Bereiche Tierhaltung und tierärztliche Praxis ausgewählt, um sie auf Eignung für die Viruzidieprüfung zu testen und gegebenenfalls zu etablieren. Des Weiteren wurde in einem zweiten Teil, in Anlehnung an die Forderungen der europäischen Normen die Prüfung zu vereinfachen, ein alternatives Zellkulturnachweissystem für das Newcastle-Disease-Virus (NDV) geprüft. Die Prüfung der viruziden Wirksamkeit erfolgte mit fünf verschiedenen Grundsubstanzen, gewählt um ein möglichst breites Spektrum an Desinfektionsmittelwirkstoffen abzudecken. Es wurden Glutaraldehyd, Ethanol, Natronlauge, Natriumhypochlorit und Peressigsäure verwendet. Die Versuche wurden mit einer niedrigen Eiweißbelastung und bei einer Temperatur von 20°C durchgeführt. Um eine praxisnahe Situation zu simulieren wurde auf, bereits in den DVG-Richtlinien, verankerten Stahl- und Holzkeimträgertests zurückgegriffen. Als mögliche Prüfviren für die Tierhaltung wurden das Equine Arteritis-Virus (EAV) und das Bovine Virus Diarrhoe Virus verwendet. Bei beiden Viren handelt es sich um weit verbreitete Tierseuchenerreger mit einer großen epidemiologischen Bedeutung. Die Untersuchung von fünf verschiedenen Desinfektionsmitteln erfolgte im Keimträgertest auf Holz. Sowohl EAV als auch BVD stellen ein weniger geeignetes Prüfvirus dar, da beide Viren enorme Titerverluste im Trocknungsvorgang der Holzkeimträger zeigten. Die Viren ließen sich zwar leicht vermehren, aber die erzielten Ausgangstiter reichten nicht aus um die Trocknungsverluste zu kompensieren und aussagekräftige Ergebnisse zu produzieren. Für den Bereich tierärztliche Praxis wurden das Feline Coronavirus (FCoV) und das Murine Parvovirus (MPV) genutzt. FCoV ist ein weltweit in Hauskatzenpopulationen vorkommendes Virus mit einer hohen Seroprävalenz und wurde daher ausgewählt. MPV wurde als Stellvertreter für die, in der Praxis häufig vorkommenden Parvovirusinfektionen gewählt. Es schien ein ideales Modellvirus aufgrund seiner weiten Verbreitung in der Forschung zu sein. Bei beiden Viren erfolgte die Prüfung auf Stahlkeimträgern. Unter Laborbedingungen konnte FCoV ohne Probleme zu hohen Titern vermehrt werden. Es gab keine nennenswerten Trocknungsverluste. FCoV erwies sich als geeignetes Prüfvirus. MPV hingegen ist bedingt durch die langen Versuchszeiten und schwierig auszuwertenden Zellkulturen, sowie wegen der niedrigen Ausgangstiter weniger geeignet als Modellvirus für die Desinfektionsmittelprüfung. Die Anzucht von NDV in Allantoisflüssigkeit von SPF Hühnereiern erschien sehr aufwendig und mit hohem Eiweißfehler belastet. In den Versuchen konnte ein deutlich höherer Eiweißgehalt als in den vergleichend geprüften, in Zellkultur angezogenen Viren nachgewiesen werden. Infolge der Probleme mit der Kultivierung der LMH-Zelllinie und den damit verbundenen langen Wartezeiten bis zur eigentlichen Versuchsdurchführung kann nur eine teilweise Empfehlung, von auf Zellkultur vermehrtem NDV (NDV (ZK)) gegeben werden. Nach Behebung dieser Probleme ist durchaus eine Ablösung, von in Allantoisflüssigkeit angezüchtetem NDV durch NDV (ZK) zu empfehlen. Die Verfälschung der Ergebnisse durch die höheren Eiweißgehalte bei Desinfektionsmitteln mit deutlichem Eiweißfehler könnten so vermieden werden.

The cost of adverse drug reactions to society in the form of deaths, chronic illness, foetal malformation, and many other effects is quite significant. For example, in the United States of America, adverse reactions to prescribed drugs is around the fourth leading cause of death. The reporting of adverse drug reactions is spontaneous and voluntary in Australia. Many methods that have been used for the analysis of adverse drug reaction data, mostly using a statistical approach as a basis for clinical analysis in drug safety surveillance decision support. This thesis examines new approaches that may be used in the analysis of drug safety data. These methods differ significantly from the statistical methods in that they utilize co variability methods of association to define drug-reaction relationships. Co variability algorithms were developed in collaboration with Musa Mammadov to discover drugs associated with adverse reactions and possible drug-drug interactions. This method uses the system organ class (SOC) classification in the Australian Adverse Drug Reaction Advisory Committee (ADRAC) data to stratify reactions. The text categorization algorithm BoosTexter was found to work with the same drug safety data and its performance and modus operandi was compared to our algorithms. These alternative methods were compared to a standard disproportionality analysis methods for signal detection in drug safety data including the Bayesean mulit-item gamma Poisson shrinker (MGPS), which was found to have a problem with similar reaction terms in a report and innocent by-stander drugs. A classification of drug terms was made using the anatomical-therapeutic-chemical classification (ATC) codes. This reduced the number of drug variables from 5081 drug terms to 14 main drug classes. The ATC classification is structured into a hierarchy of five levels. Exploitation of the ATC hierarchy allows the drug safety data to be stratified in such a way as to make them accessible to powerful existing tools. A data mining method that uses association rules, which groups them on the basis of content, was used as a basis for applying the ATC and SOC ontologies to ADRAC data. This allows different views of these associations (even very rare ones). A signal detection method was developed using these association rules, which also incorporates critical reaction terms.
Doctor of Philosophy

The cost of adverse drug reactions to society in the form of deaths, chronic illness, foetal malformation, and many other effects is quite significant. For example, in the United States of America, adverse reactions to prescribed drugs is around the fourth leading cause of death. The reporting of adverse drug reactions is spontaneous and voluntary in Australia. Many methods that have been used for the analysis of adverse drug reaction data, mostly using a statistical approach as a basis for clinical analysis in drug safety surveillance decision support. This thesis examines new approaches that may be used in the analysis of drug safety data. These methods differ significantly from the statistical methods in that they utilize co variability methods of association to define drug-reaction relationships. Co variability algorithms were developed in collaboration with Musa Mammadov to discover drugs associated with adverse reactions and possible drug-drug interactions. This method uses the system organ class (SOC) classification in the Australian Adverse Drug Reaction Advisory Committee (ADRAC) data to stratify reactions. The text categorization algorithm BoosTexter was found to work with the same drug safety data and its performance and modus operandi was compared to our algorithms. These alternative methods were compared to a standard disproportionality analysis methods for signal detection in drug safety data including the Bayesean mulit-item gamma Poisson shrinker (MGPS), which was found to have a problem with similar reaction terms in a report and innocent by-stander drugs. A classification of drug terms was made using the anatomical-therapeutic-chemical classification (ATC) codes. This reduced the number of drug variables from 5081 drug terms to 14 main drug classes. The ATC classification is structured into a hierarchy of five levels. Exploitation of the ATC hierarchy allows the drug safety data to be stratified in such a way as to make them accessible to powerful existing tools. A data mining method that uses association rules, which groups them on the basis of content, was used as a basis for applying the ATC and SOC ontologies to ADRAC data. This allows different views of these associations (even very rare ones). A signal detection method was developed using these association rules, which also incorporates critical reaction terms.
Doctor of Philosophy

Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, June 2015.
"May 2010." Cataloged from PDF version of thesis.
Includes bibliographical references (pages 72-76).
This thesis forms part of a larger effort at MIT Lincoln Laboratory to develop a micro-UAV based platform, capable of detecting survivors through rubble, under the funding of the New Technology Initiative (NTI) program. In support of this goal the thesis makes three distinct contributions. First, the operating environment of a disaster scenario is characterized. To do so, the electrical properties of different residential construction materials are determined and an analytical model for the behavior of a radar operating in this environment is developed. Second, preliminary efforts were made towards the miniaturization of the radar back-end by designing circuitry that generates the transmit waveform. Additionally an analog filter was developed to attenuate unwanted signals on the receive end. Lastly metaheuristic topology optimization was applied towards the design of antennas for the radar front-end. A novel, algorithmic extension to an established metaheuristic algorithm is demonstrated and tested. Additionally a new antenna parametrization based on Bezier curves is developed and evaluated against the established pixel-based parametrization.
by George Pantazis.
M. Eng.

Im Zuge der Überarbeitung der DVG-Richtlinie zur Prüfung der Viruzidie chemischer Desinfektionsmittel in der Nutztierhaltung wurden BVDV, EAV und PPV auf ihre Eignung als potentielle Prüfviren getestet. Das bisher vorgeschriebene Newcastle-Disease-Virus und das Vacciniavirus sollen mit anderen behüllten Viren wie BVDV oder EAV verglichen werden. Beweggründe für einen möglichen Austausch sind die derzeitige Situation in der Tierseuchenbekämpfung, die Erhöhung der Anwendersicherheit durch Wegfall des zoonotischen Potentials, die einfachere Kultivierung und Handhabung der Prüfviren sowie speziell bei NDV die höhere Aussagekraft der gewonnenen Ergebnisse. Die Desinfektionsmittelversuche wurden gemäß DVG-Richtlinie auf Pappelholzkeimträgern durchgeführt, wobei das jeweilige, mit fetalem Kälberserum vermischte, Virus auf die Keimträger aufgetragen und angetrocknet wurde. Die DVG schreibt eine Trocknung im Brutschrank von 60 Minuten bei 37°C vor. Um die Trocknungsverluste der eingesetzten Viren zu untersuchen, wurden vergleichende Trocknungsversuche wie vorgeschrieben im Brutschrank und im Exsikkator bei Raumtemperatur durchgeführt. Die nach der Trocknung im Brutschrank durchgeführten Desinfektionsmittelversuche wurden mit chemischen Grundsubstanzen kommerziell erhältlicher Desinfektionsmittel durchgeführt. Dabei kamen verschiedene Anwendungskonzentrationen von Ameisensäure, Glutaraldehyd, Natriumhypochlorit, Natronlauge und Peressigsäure zum Einsatz. Bei der vorgeschriebenen Trocknung im Brutschrank kam es zu Titerverlusten von 0,8 bis zu 2,75 log10KID50/ml. Durch eine Trocknung der Holzkeimträger von 30 Minuten bei Raumtemperatur im Exsikkator konnten die Titerverluste auf 0,3 bis 1,0 log10KID50/ml reduziert werden. In den nachfolgenden Desinfektionsversuchen zeigte sich die besonders hohe Tenazität von PPV. Es war den eingesetzten Desinfektionsmitteln gegenüber deutlich resistenter als alle anderen untersuchten Viren. In den Trocknungsversuchen zeigte PPV mit Abstand die niedrigsten Titerverluste. Mit BVDV und EAV konnten zwar ausreichend hohe Titer erzielt werden, allerdings waren die Trocknungsverluste beider Viren sehr hoch. In den Keimträgerversuchen konnte nur in wenigen Versuchen eine Titerreduktion von mehr als 3 Logarithmusstufen erreicht werden. Hier könnte zukünftig die Trocknung im Exsikkator Abhilfe schaffen, um die Trocknungsverluste zu minimieren und eine höhere Titerreduktion zu ermöglichen. Die Ergebnisse einer früheren Arbeit zeigen identische Ergebnisse von NDV und BVDV im Keimträgertest. Ein Ersatz von NDV durch BVDV ist somit zu empfehlen. Eine Verwendung der untersuchten Viren gemäß den derzeitigen DVG-Richtlinien ist möglich, allerdings müssten im Zuge der weiteren Harmonisierung von CEN- und DVG-Richtlinie die Kontrolltiter entsprechend erhöht werden, um die von der CEN geforderte Titerreduktion von vier Logarithmusstufen für eine vollständige Virusinaktivierung einzuhalten. Die Vermehrung der untersuchten Viren zu höheren Ausgangs-, bzw. Kontrolltitern sollte daher Gegenstand weiterer Forschungsarbeit sein. Einer weiteren Verwendung der bisherigen Prüfviren BEV und REOV steht nichts im Wege. Aufgrund der Ergebnisse der vergleichenden Trocknungsversuche wird für alle untersuchten Viren zukünftig eine 30 minütige Trocknung im Exsikkator empfohlen.

Patients often exhibit premonitory abnormalities in vital signs before an adverse clinical outcome. Patient survival may depend on the decisions of nurses to call for assistance. There is a paucity of published early warning scores (EWS) literature for general ward use from South Africa. In a public hospital in South Africa, the study aimed to develop, validate and test the impact of implementation of a modified early warning scoring (MEWS) system vital signs chart and training programme designed to improve hospital nurses’ performance in early identification of postoperative clinical and physiological deterioration in adult patients.

Adolescents and young adults represent a growing proportion of people living with HIV around the world and have worse outcomes than all other age groups. Retention along each step of the HIV care cascade is essential for optimal care, but importantly, achieving sustained adherence to antiretroviral therapy (ART) and subsequent viral suppression is necessary for decreasing morbidity and mortality and reducing further transmission. The overarching goal of this dissertation was to assess health-services interventions aimed at improving ART adherence among adolescents and young adults living with HIV, and prospectively evaluate one such intervention – point-of-care viral load testing – in a randomized control trial. First, a systematic review was conducted to assess and synthesize recent research on interventions aimed at improving ART adherence among adolescents and young adults living with HIV in a resource-limited setting. Evidence from the review indicated that comprehensive models of HIV care, re-structuring how HIV services were delivered to patients, which included increased monitoring of adolescents and young adults through home visits or case management in addition to standard clinical care improved ART adherence. Second, a randomized control trial was conducted to evaluate the implementation and effect of point-of-care viral load testing compared to standard laboratory-based testing. The trial had two primary objectives: 1) to assess the efficiency of point-of-care viral load testing, and 2) evaluate the effect of point-of-care viral load testing on health outcomes including ART adherence and viral suppression. The research protocol is described including study design, the point-of-care viral load testing intervention, analysis plan, and outcome definitions. Lastly, the results of this trial are reported which indicate that point-of-care viral load testing can be feasibly integrated into a low-resource, clinical setting. A majority of point-of-care viral load test results (81.8%; 148/181) were processed and returned the same day, with a mean time between blood collection and participant receipt of results of 2.7 hours (IQR: 2.5-3.2; range 1.7-6.0). Point-of-care viral load testing also appeared to improve the accuracy of reported ART adherence, an unanticipated finding. In the point-of-care arm, participants who reported sub-optimal ART adherence on any of 3 adherence questions were more likely to have a VL >1,000 copies/mL (OR: 6.57; 95% CI: 2.12-25.21), compared to participants in the standard arm among whom the association was weaker (OR: 2.62; 95% CI: 0.97-7.44). There was no difference in viral load outcomes between arms. Overall, this dissertation addresses gaps in our knowledge about interventions aimed at improving ART adherence among adolescents and young adults living with HIV. The key finding is that point-of-care viral load testing can simplify the viral load monitoring process and help clinicians accurately identify adolescents and young adults with a high viral load in order to provide enhanced adherence counseling or make clinical decisions regarding appropriate treatment options faster. Point-of-care viral load testing could be used in concert with other interventions which address additional barriers to ART adherence among adolescents and young adults such as forgetfulness, stigma, or lack of social support. As the public health field continues to focus on improving HIV outcomes among this vulnerable age group, these findings can guide the optimization of HIV services and the development of combination interventions which could increase the number of adolescents and young adults who achieve sustained ART adherence and viral suppression.

Tese de mestrado, Biologia Evolutiva e do Desenvolvimento, Universidade de Lisboa, Faculdade de Ciências, 2015
The complexity of life forms cannot be explained without the concept of symbiosis. Symbiotic relations exist abundantly in nature, particularly the ones between bacteria and eukaryotic hosts. One of the most widespread endosymbiotic bacteria described belongs to the genus Wolbachia, naturally infecting arthropods and nematodes. In arthropods, Wolbachia induces reproductive manipulations, to promote infected female’s fitness as they are vertically transmitted, maternally. Additionally, in Drosophila melanogaster, they have been shown to confer protection against viral infections. Being an obligatory vertically-transmitted endosymbiont, Wolbachia phylogeny should recapitulate that of its hosts. However, several studies show that host and symbiont phylogenies are not concordant, suggesting that horizontal transfers must have occurred throughout time. This has been confirmed, namely between parasitoid wasps and their hosts. Considering these observations, the present project aimed at uncovering if and at which rate horizontal transmission of Wolbachia could occur between Drosophila melanogaster and its natural parasitoid Leptopilina boulardi. Also, we tested if the viral protection phenotype induced in Drosophila would be passed on to the novel host, after this horizontal transfer event. Simultaneously we screened a wild-caught population of Leptopilina heterotoma for Wolbachia presence. We obtained infected individuals with which we established an isofemale line and derived Wolbachia-negative counterparts using antibiotic treatment. With this tool, we characterized the effects of Wolbachia presence upon viral systemic infection. Our results show that horizontal transmission of Wolbachia happens between Leptopilina boulardi and its host, but the infection is not stably maintained. We also see that these wasps do not appear to be susceptible to viruses that are pathogenic in Drosophila (specifically DCV and FHV) and appear to be mildly Detrimental to Wolbachia-infected Leptopilina heterotoma. Finally, we have verified that a natural endosymbiont infection appears to delay full development time in Leptopilina heterotoma, although no effect is detected for longevity. With this work we have established an experimental system for the controlled and systematic study of the complex interactions between Drosophila, parasitoid wasps, Wolbachia and viruses.
A diversidade de formas devida dificilmente é explicada sem ser tido em conta o conceito de simbiose. Relações simbióticas são abundantemente encontradas em ambientes naturais. Os primeiros eventos de endossimbiose conhecidos terão ocorrido há cerca de 1,5 milhares de milhão de anos atrás. Estes acontecimentos descrevem a incorporação de cianobactérias e proteobactérias ancestrais em organismos procariotas. Quando a simbiose se tornou mutualista obrigatória, estes organismos procariotas associados a endossimbiontes tornaram-se nos primeiros eucariotas do planeta, e os seus anteriormente designados endossimbiontes tornaram‐se organelos, nomeadamente cloroplastos e mitocôndrias. Atualmente existem incontáveis exemplos de organismos vivos que não existiriam se não se estabelecessem relações simbióticas entre diferentes entidades biológicas, constituindo a base para a enorme diversidade de formas de vida existentes. Alguns dos casos mais frequentes de interações entre diferentes organismos que moldam inquestionável e determinantemente a história evolutiva do planeta são os que ocorrem entre procariotas e hospedeiros eucariotas. Estes sistemas podem ser encontrados em todas As circunstâncias, quer em metazoários como plantas e animais, quer em organismos unicelulares. Por exemplo, o filo Porífera realiza incontáveis associações com microrganismos bacterianos que lhe permitem obter nutrientes mais eficazmente ou ainda os vários casos de plantas que formam associações com bactérias fixadoras de azoto. Numa tentativa de classificar os diferentes tipos de interações que podem ocorrer entre dois ou mais organismos, foram atribuídos nomes a categorias discretas que ocorrem no espectro de interações naturais possíveis. Relações simbióticas podem ser comensais, mutualistas ou parasíticas. Comensalismo descreve o tipo de interações em que um organismo beneficia da relação que desenvolve com outro, enquanto o segundo permanece indiferente. Relações mutualistas englobam situações em que a associação é mutualmente benéfica para ambos os envolvidos. Parasitismo implica que um dos envolvidos seja prejudicado, para benefício do outro. Estas duas últimas formas de interação estão intimamente relacionadas, na medida em que as medidas de adaptação que um endossimbionte tem de sofrer para poder invadir e colonizar um hospedeiro, qualquer que seja a interações que acabe por vingar, são semelhantes para uma relação mutualista ou parasita, especialmente se considerarmos as relações abundantes que se estabelecem entre bactérias e hospedeiros eucariotas. No entanto, e apesar das referidas classificações existirem e serem relevantes, é difícil atribuir qualidades discretas a endossimbiontes, uma vez que os efeitos que induzem no seu hospedeiro podem variar entre mutualistas ou patogénicos, consoante vários aspectos (como factores ambientais). Um exemplo privilegiado deste tipo de comportamento variável é o das bactérias do género Wolbachia. Estas são alfa-proteobactérias, membros do grupo Rickettsiales (que engloba todos as bactérias endossimbióticas obrigatórias conhecidas), que infectam artrópodes e algumas espécies de nematodes filariais. Este endossimbionte é um dos mais representados na natureza, infectando mais de 60% de todos os insectos conhecidos, para além de presente em ácaros, aranhas, escorpiões e isópodes. Sendo um dos organismos mais bem estudados atualmente no que diz respeito a relações de simbiose, existem vários estudos que descrevem algumas das adaptações que sofreu de modo a proliferar nas células dos hospedeiros. Nomeadamente, a bactéria utiliza mecanismos de transporte vesicular para viajar dentro das células do hospedeiro. No entanto, a característica deste género que é indubitavelmente mais estudada é a sua capacidade de manipular o sistema reprodutivo do hospedeiro em seu proveito. Existem diferentes formas segundo as quais Wolbachia consegue manipular a reprodução dos seus hospedeiros, nomeadamente: feminização, morte de machos, partenogénese e incompatibilidade citoplasmática (IC). Feminização descreve a transformação fenotípica em fêmeas de organismos geneticamente masculinos; morte de machos acontece quando machos infectados são inviabilizados, disponibilizando mais recursos para as irmãs que possam transmitir a infecção à geração seguinte; partenogénese descreve a produção de prole unicamente feminina contribuição parental masculina; por fim, a manipulação reprodutiva mais comum, a IC descreve o processo segundo o qual fêmeas infetadas geram menos prole viável quando fertilizadas por machos não infetados (ou se ambos hospedarem estirpes incompatíveis). Todos estes processos de manipulação reprodutiva têm como objectivo maximizar a dispersão e colonização de Wolbachia pelo maior número de indivíduos possível, o que por sua vez é conseguido através do favorecimento da descendência feminina. O principal motivo que explica estes processos prende‐se com a forma canónica de transmissão de Wolbachia entre hospedeiros, que é feita verticalmente por via materna. Uma outra influência que Wolbachia exerce sobre os seus hospedeiros prende‐se com a capacidade de proteger Drosophila melanogaster contra (algumas) infeções por vírus de RNA. Esta capacidade foi descrita recentemente (não só para Drosophila mas também para o mosquito Culex pipiens) e desde então múltiplos trabalhos têm sido desenvolvidos na tentativa de caracterizar e determinar os mecanismos subjacentes. É sabido que Wolbachia protege contra Drosophila C Virus (DCV) e Flock House Virus (FHV), entre outros vírus de RNA, mas que a proteção não se estende para vírus de DNA (que não se conhece infectarem naturalmente espécies de Drosophila) e que, inclusive, diferentes níveis de proteção estão associados a diferentes estirpes da bactéria. Outra peculiaridade deste género de endossimbiontes prende-se com a filogenia discordante que apresentam relativamente à dos seus hospedeiros. Tendo em conta que são verticalmente transmitidas, seria de esperar que a árvore filogenética das estirpes de Wolbachia espelhasse, com alguma exatidão, a árvore filogenética dos seus respetivos hospedeiros. Isto não se verifica sugerindo que, além da transmissão vertical, eventos de transmissão horizontal entre hospedeiros têm de ter ocorrido ao longo do tempo. Adicionalmente, estudos baseados nestas filogenias de Wolbachia permitem inferir que existem enormes semelhanças entre as estirpes albergadas por certos insectos filogeneticamente distantes, nomeadamente entre vespas parasitoides e os seus respectivos hospedeiros. Tendo isto em conta, foram conduzidos estudos que determinaram que a bactéria pode ser transmitida horizontalmente entre diferentes hospedeiros por canibalismo de animais infectados, por partilha próxima de nichos ecológicos e através de um vector como uma vespa parasitóide. Reunindo toda a informação apresentada acima, das características da Wolbachia, especificamente da sua capacidade de induzir proteção viral em Drosophila, da sua filogenia discordante (indicativa de eventos de transmissão horizontal) e da existência de casos reportados em que vespas parasitoides atuam como vector transportador de endossimbiontes, formulámos as questões que apresentamos de seguida. 1- Consegue a Wolbachia conferir proteção viral num hospedeiro parasitoide recem-adquirido, fruto de um evento de transmissão horizontal? 2- Está uma população natural de vespas parasitoides protegida contra infecções virais, pela sua estirpe nativa de Wolbachia? 2.1- Como responde esta população natural, em comparação com as vespas mantidas no laboratório? 2.2- Existem custos associados à manutenção de Wolbachia? Começámos por tentar responder à primeira questão estabelecendo linhas isogénicas da vespa Leptopilina boulardi não infectadas por Wolbachia e sujeitando-as a hospedeiros de Drosophila melanogaster contendo Wolbachia. Utilizando duas linhas de moscas infectadas com estirpes individuais diferentes, sujeitámos as vespas a estes hospedeiros infectados e recolhemos toda a descendência após este evento de parasitação. Com estas fêmeas estabelecemos linhas isogénicas, das quais recolhemos, na geração seguinte, indivíduos suficientes que nos permitisse extrair DNA e testar a presença de Wolbachia por PCR. Com estes dados pudemos inferir a taxa de transmissão horizontal entre Leptopilina boulardi e Drosophila melanogaster. Numa tentativa de avaliar se a proteção viral conferida em mosca era transmitida com o endossimbionte para o novo hospedeiro estabelecemos um protocolo de infecção viral sistémica em vespa. No entanto, verificámos que a espécie Leptopilina boulardi não parece ser susceptível aos vírus de RNA que são canonicamente testados em Drosophila. Atestámos também que, nesta espécie, uma transmissão horizontal de Wolbachia não origina uma infecção estável, que seja em última análise, verticalmente mantida. Para responder à questão 2, recolhemos indivíduos da natureza e testámos a presença de Wolbachia assim como determinámos a espécie em questão. Deparamo-nos com uma linha de Leptopilina heterotoma, infectada com Wolbachia. Para estabelecermos um controlo negativo, usámos um tratamento de antibiótico que tratou a infecção, proporcionando duas linhas semelhantes de vespa, uma com e outra sem Wolbachia. Posteriormente, infecção viral foi realizada para esta espécie, onde vimos um efeito pequeno da ação de DCV, apenas detectável na linha que continha a infecção bacteriana de origem mas não na linha tratada. Para determinar custos, realizámos ainda medições quanto ao tempo total de desenvolvimento e longevidade de ambas as linhas de Leptopilina heterotoma, onde detectámos um possível efeito da Wolbachia a atrasar ligeiramente o desenvolvimento de ovo até adulto. Sumariamente, os nossos resultados indicam que a transmissão horizontal de Wolbachia ocorre, embora o estabelecimento de uma infeção vertical estável seja seja, neste caso, indetectável. Concluímos também acerca do efeito que uma infecção viral pode ter (ou não) sobre uma espécie com a qual provavelmente partilha nichos ecológicos na natureza (considerando que tanto Leptopilina boulardi como Leptopilina heterótoma são parasitoides naturais de Drosophila melanogaster, o hospedeiro por excelência de DCV). Podemos ainda verificar que a presença deste endossimbionte pode induzir custos num hospedeiro nativo, como de resto é verificado noutras espécies.

MSc (Med), Faculty of Health Sciences, University of the Witwatersrand, 2011
BACKGROUND: Human Immunodeficiency Virus (HIV) is a global epidemic with growing numbers of people on highly active anti‐retroviral therapy (HAART) programmes. Effectiveness of treatment needs to be monitored to ensure the uncompromised well being of patients. This is currently done using both Viral Load (VL) and CD4 cell counts for HAART initiation and follow‐up. Although VL is the best predictor of disease progression it is often too expensive for monitoring patients in resource‐limited settings. There is thus a need for a cheaper, more accessible alternative to monitor long term patient response to therapy. METHODS: This study evaluated the use of a recently described flow cytometric assay of CD38 expression (previously developed at the Johannesburg Flow Cytometry Reference Laboratory) in a cohort of HIV+ patients failing 1st line therapy, who were subsequently enrolled onto 2nd line HAART. CD38 and CD8 were “piggy ‐backed” onto the PLG/CD4 protocol and mean fluorescence intensity (MFI) of the CD8/38 expression was monitored longitudinally. Patterns of CD38 expression were compared to 1st line treatment observations to establish equivalence in the predictive power of CD38 expression of fluctuation in viral load on 2nd line treatment patients. In addition, the effect of sample age on assay accuracy was tested before implementation of the CD38 assay at a secondary testing site. RESULTS: The patterns observed in the cohort of 2nd line therapy patients mirrored patterns previously seen in 1st line therapy with 55% of patients showing a continuous decline in CD38 MFI that mimicked changes in VL. The remaining 33% of patients had non‐specific increases in CD38 MFI without concurrent increases in VL and one patient showed irregular VL and CD38 MFI (non‐responder). The CD38 assay showed acceptable accuracy and reproducibility up to 48 hours after venesection (%CV<5%). Implementation at the secondary testing site was successful with 98% similarity (%CV<5%) compared to the reference laboratory. CONCLUSION: CD38 monitoring of 2nd line therapy patients showed comparable patterns to observations in 1st line therapy patients. The assay proved stable over time and easy to implement at another PLG/CD4 testing facility. As such, the CD38 assay offers a cost‐effective, reliable real time supplementary test to long‐term VL monitoring of HIV infected patients on the national ART programme.

The present dissertation, written in the form of a case study, aims to present the Load Zero Foundation (LZF), an American non-for-profit organization dedicated to funding HIV viral load testing in the developing world. The organization was founded in 2013 and is now in the process of gathering the funds to implement its first full low cost laboratory entirely dedicated to viral load testing. We will examine LZF’s fundraising efforts so far and suggest some future strategies for gathering the rest of the funds needed. In the following pages we will introduce the dissertation outline and then provide the reader with an overview of the main literature collected about HIV, viral load testing, Haiti and its history in AIDS relief and finally, funding options for NGOs. Afterwards, the case study presents the LZF as a social enterprise, providing an overview of its strategies and operations - while referring to the importance of viral load testing in the fight against HIV. Lately, the case study examines the evolution of funding for organizations, and how far the LZF is gathering the funds for its first laboratory. Finally we provide teaching notes for inclass discussion about the case study, and conclude with final remarks and possible recommendations for the LZF on future fundraising strategies.
A presente dissertação, escrita sob a forma de um caso-estudo, tem como principal objectivo apresentar a Load Zero Foundation, uma organização americana sem fins lucrativos dedicada ao financiamento de testes de carga viral de HIV em países em desenvolvimento. A organização, fundada em 2013, está em processo de angariação de fundos para implementar o seu primeiro laboratório completo de baixo custo inteiramente dedicado a testes de carga viral. Vamos analisar os esforços desenvolvidos até ao momento pela LZF para angariar fundos, e sugerir algumas estratégias para reunir os fundos que faltam. Nas próximas páginas vamos apresentar o esquema dissertação e fornecer ao leitor uma visão geral da literatura analisada sobre HIV, testes de carga viral, o Haiti e sua história no combate à SIDA e, finalmente, as opções de financiamento para as ONGs. Depois disso, o caso-estudo apresenta a LZF como uma empresa social, apresentando uma visão geral das estratégias e operações - referindo a importância dos testes de carga viral na luta contra o HIV. Posteriormente, o caso-estudo analisa a evolução do financiamento para ONGs, apresentando a situação LZF em reunir os fundos necessários para estabelecer o seu primeiro laboratório. Finalmente, fornecemos algumas notas explicativas para aplicação do caso em sala de aula, e concluímos com considerações finais e recomendações para possíveis estratégias futuras de angariação de fundos para a LZF.

Hintergrund: Die bakterielle Meningitis hat eine Letalität von 10-20%. Das Hirnödem stellt bei ca. 14 % der Erkrankten eine prognosebestimmende Komplikation dar. Ein aktueller Forschungsansatz umfasst die Bedeutung der Aquaporine für die Entwicklung, Aufrechterhaltung und Resorption der verschiedenen Hirnödemformen, insbesondere des zytotoxischen und des vasogenen Hirnödems. In dieser Arbeit wird untersucht, ob Aquaporin 1 und Aquaporin 4 im Liquor von Patienten mit bakterieller und viraler Meningitis, im Vergleich zu einer gesunden Kontrollgruppe, nachweisbar sind. Zudem sollte geklärt werden, ob sich hieraus eine differenzialdiagnostische Einordnung ergibt und sich Rückschlüsse auf das Ausmaß eines Hirnödems und das Outcome schließen lassen. Methode: Aquaporin 1 und 4 wurde im Liquor und im Serum von Patienten mit bakterieller (nCSF = 35 , nSerum = 20) und viraler  (nCSF = 22) Meningitis sowie in einer Kontrollgruppe (nCSF = 27 , nSerum = 12) mittels eines (kommerziell erhältlichen) ELISAs bestimmt. Klinische Daten und Routinelaborparameter wurden verglichen und in Korrelation zu den Aquaporinkonzentrationen gesetzt. Ergänzend wurde bei einer Untergruppe der Patienten mit bakterieller Meningitis (n = 8) eine neuropsychologische Testung durchgeführt. Ergebnisse: Aquaporin 1 und 4 ließen sich in allen Gruppen nachweisen, ca. 40% der Aquaporin 4 Konzentrationen lagen unterhalb der Nachweisgrenze des ELISAs. Im Gruppenvergleich aller drei Gruppen unterschieden sich die Aquaporin 1-Konzentrationen (p = 0,0001) und die Aquaporin 4-Konzentrationen (p = 0,035) im Liquor signifikant voneinander. In der Gruppe der Patienten mit bakterieller Meningitis ließ sich eine negative Korrelation zwischen Aquaporin 1 und 4 im Liquor feststellen (r = - 0,519, p = 0,002). Aussagekräftige Korrelationen der klinischen Daten, der liquor- und laborchemischen Parameter sowie der neuropsychologischen Testergebnisse zu den Aquaporin 1- und Aquaporin 4-Konzentrationen fanden sich nicht.  Diskussion: In dieser Arbeit konnte erstmalig gezeigt werden, dass Aquaporin 1 und Aquaporin 4 im Liquor (und Serum) von Patienten mit einer bakteriellen und viralen Meningitis sowie in einer Kontrollgruppe nachweisbar sind. Für Aquaporin 1 und Aquaporin 4 im Liquor fanden sich signifikante Unterschiede im Vergleich aller Gruppen im Kruskal-Wallis-Test. Rückschlüsse bezüglich einer differenzial-diagnostischen Einordnung zur viralen Meningitis konnten nicht gezogen werden. Aussagen zur Schwere eines Hirnödems und zur Prognose können mit den vorliegenden Daten nicht getroffen werden. Der Ursprung der gemessenen Aquaporine bei Patienten mit Meningitis lässt sich in dieser Arbeit nicht abschließend klären und bedarf weiterer Grundlagenforschung.

Background: Viral hepatitis C (HCV) represents a major public health problem worldwide and also in the Czech Republic. There are as many as 80,000 people have been living with chronic HCV in Czechia since 2015, most of them are/were drug addicts who have been infected by contaminated syringes. Global and national efforts to eliminate HCV are currently underway, focusing primarily on improving the quality of treatment continuity (sustainability, uninterrupted treatment) which involves ensuring the availability of testing for all patients, patients' involvement in their own treatment, sustaining treatment, achieving a response rate and the necessary follow-up care. Objective: To describe the HCV continuum of care in people who inject drugs (mapping testing rate, treatment uptake and treatment completion), and to describe the factors that affect this process. Based on the collected data, to formulate recommendations for addiction care professionals in order to improve HCV continuum of care. Methodology: A questionnaire survey among clients of low-threshold centres in Prague was carried out. The convenient sample consisted of a total of 60 respondents, 20 from each of the three centres. Data were analyzed using descriptive statistics. Data collection was realised in August 2019. Results: Out of the 60...

This thesis explores the technical feasibilty of creating a remote laboratory in the field of microelectronics fabrication. It also includes the evaluation of the developed laboratory as a teaching tool.
PhDElectronicEngineering

Desinfektionsmittel sind ein elementarer Bestandteil der Tierseuchenbekämpfung und damit auch der Lebensmittelsicherheit. Die Prüfung chemischer Desinfektionsmittel ist Voraussetzung für deren zuverlässige Wirksamkeit und zielgerichteten Einsatz. In Deutschland geschieht dies nach den Richtlinien der Deutschen Veterinärmedizinischen Gesellschaft e.V. (DVG). Seit der ersten Fassung sind die Richtlinien einem ständigen Anpassungsprozess unterworfen. Im Zuge der europäischen Harmonisierung gilt es nun, sich gesamteuropäischen Richtlinien, verfasst durch das europäische Komitee für Normung (Comité Européen de Normalisation) (CEN) anzupassen. Das Thema dieser Arbeit entwickelte sich im Kontext der derzeitigen Diskussion über Verbesserungsvorschläge zu den bestehenden Richtlinien und deren Anpassung an die europäischen Normen. Es wurden je zwei Testviren für die Bereiche Tierhaltung und tierärztliche Praxis ausgewählt, um sie auf Eignung für die Viruzidieprüfung zu testen und gegebenenfalls zu etablieren. Des Weiteren wurde in einem zweiten Teil, in Anlehnung an die Forderungen der europäischen Normen die Prüfung zu vereinfachen, ein alternatives Zellkulturnachweissystem für das Newcastle-Disease-Virus (NDV) geprüft. Die Prüfung der viruziden Wirksamkeit erfolgte mit fünf verschiedenen Grundsubstanzen, gewählt um ein möglichst breites Spektrum an Desinfektionsmittelwirkstoffen abzudecken. Es wurden Glutaraldehyd, Ethanol, Natronlauge, Natriumhypochlorit und Peressigsäure verwendet. Die Versuche wurden mit einer niedrigen Eiweißbelastung und bei einer Temperatur von 20°C durchgeführt. Um eine praxisnahe Situation zu simulieren wurde auf, bereits in den DVG-Richtlinien, verankerten Stahl- und Holzkeimträgertests zurückgegriffen. Als mögliche Prüfviren für die Tierhaltung wurden das Equine Arteritis-Virus (EAV) und das Bovine Virus Diarrhoe Virus verwendet. Bei beiden Viren handelt es sich um weit verbreitete Tierseuchenerreger mit einer großen epidemiologischen Bedeutung. Die Untersuchung von fünf verschiedenen Desinfektionsmitteln erfolgte im Keimträgertest auf Holz. Sowohl EAV als auch BVD stellen ein weniger geeignetes Prüfvirus dar, da beide Viren enorme Titerverluste im Trocknungsvorgang der Holzkeimträger zeigten. Die Viren ließen sich zwar leicht vermehren, aber die erzielten Ausgangstiter reichten nicht aus um die Trocknungsverluste zu kompensieren und aussagekräftige Ergebnisse zu produzieren. Für den Bereich tierärztliche Praxis wurden das Feline Coronavirus (FCoV) und das Murine Parvovirus (MPV) genutzt. FCoV ist ein weltweit in Hauskatzenpopulationen vorkommendes Virus mit einer hohen Seroprävalenz und wurde daher ausgewählt. MPV wurde als Stellvertreter für die, in der Praxis häufig vorkommenden Parvovirusinfektionen gewählt. Es schien ein ideales Modellvirus aufgrund seiner weiten Verbreitung in der Forschung zu sein. Bei beiden Viren erfolgte die Prüfung auf Stahlkeimträgern. Unter Laborbedingungen konnte FCoV ohne Probleme zu hohen Titern vermehrt werden. Es gab keine nennenswerten Trocknungsverluste. FCoV erwies sich als geeignetes Prüfvirus. MPV hingegen ist bedingt durch die langen Versuchszeiten und schwierig auszuwertenden Zellkulturen, sowie wegen der niedrigen Ausgangstiter weniger geeignet als Modellvirus für die Desinfektionsmittelprüfung. Die Anzucht von NDV in Allantoisflüssigkeit von SPF Hühnereiern erschien sehr aufwendig und mit hohem Eiweißfehler belastet. In den Versuchen konnte ein deutlich höherer Eiweißgehalt als in den vergleichend geprüften, in Zellkultur angezogenen Viren nachgewiesen werden. Infolge der Probleme mit der Kultivierung der LMH-Zelllinie und den damit verbundenen langen Wartezeiten bis zur eigentlichen Versuchsdurchführung kann nur eine teilweise Empfehlung, von auf Zellkultur vermehrtem NDV (NDV (ZK)) gegeben werden. Nach Behebung dieser Probleme ist durchaus eine Ablösung, von in Allantoisflüssigkeit angezüchtetem NDV durch NDV (ZK) zu empfehlen. Die Verfälschung der Ergebnisse durch die höheren Eiweißgehalte bei Desinfektionsmitteln mit deutlichem Eiweißfehler könnten so vermieden werden.