This thesis showed that dogs with natural infection with B. canis had both renal and cardiac dysfunction, both of which can be classified as complications of babesiosis and would thus necessitate supportive therapy. This thesis demonstrated that RTE celluria, proteinuria, and variable enzymuria and azotaemia occur in dogs with babesiosis. However, these were all minimal changes and all could be consistent with hypoxia, reduced GFR, or reduced cardiac output This thesis showed that dogs with naturally occurring babesiosis had significant urine met-haemoglobin with no evidence of blood met-haemoglobin. The possibility would be that the urinary methaemoglobin was either produced in the kidney or possibly by oxidation of haemoglobin to met-haemoglobin in the bladder. It has been shown experimentally that met-haemoglobin can be toxic. The combination of reduced GFR, anaemic hypoxia, and met-haemoglobin can all act synergistically to cause renal damage. Renal haemodynamics are also much more likely to be abnormal when cardiac dysfunction is present Reduced renal blood flow and glomerular filtration rate are evidence of redistribution of blood flow that commonly occurs in early heart failure. An important finding in this thesis was that dogs with babesiosis had lower serum sodium than control dogs but there was no difference between mild, severe, or complicated cases of babesiosis. In addition, dogs with babesiosis had a lower fractional clearance of sodium than Clinically healthy control dogs, which can be interpreted as sodium retention by the kidneys. This sodium retention would also result in water retention , which will result in an expansion of the plasma volume. In the past heart lesions in canine babesiosis were regarded as rare complications, with the majority of lesions being reported as incidental findings at post-mortem examination of complicated babesiosis cases. This thesis has demonstrated that cardiac lesions to be common in canine babesiosis. This thesis showed that that ECG changes in babesiosis were similar to the pattern described for myocarditis and myocardial ischaemia, and together with the histopathological findings indicated that the heart suffers from the same pathological processes described in other organs in canine babesiosis, namely inflammation and hypoxia. As the clinical application of the ECG changes found in this thesis was limited, cardiovascular assessment should be based on functional monitoring rather than ECG. Using cardiac troponin as a marker of myocardial injury, this thesis showed that myocardial cell injury occurs with canine babesiosis. Cardiac troponins, especially troponin I, are sensitive markers of myocardial injury in canine babesiosis, and the magnitude of elevation of plasma troponin I concentrations appears to be proportional to the severity of the disease. ECG changes and serum cardiac troponin were correlated with histopathology. On cardiac histopathology from dogs that succumbed to babesiosis, haemorrhage, necrosis, inflammation and fibrin microthrombi in the myocardium were documented, all of which would have resulted in ECG changes and elevations in cardiac troponin. Myocardial infarction causes left ventricular failure, which will result in hypotension and an expansion of the plasma volume due to homeostatic mechanisms. This thesis showed that dogs with babesiosis had hypoalbuminaemia, which may be because of intravascular volume dilution due to fluid retention. In disease hypoalbuminaemia can occur as a negative acute-phase protein. In the light of the cardiac changes, hyponatraemia, and hypotension, a probable cause would be fluid retention due to myocardial disease. This thesis showed that dogs with babesiosis had left ventricular lesions, which can result in systolic heart failure. / Thesis (PhD)--University of Pretoria, 2005. / Veterinary Tropical Diseases / unrestricted

Eine chronische Infektion mit dem Hepatitis B Virus (HBV) ist ein wichtiges, jedoch vernachlässigtes Problem der globalen Gesundheit. Weltweit sind ungefähr 257 Millionen Personen chronisch mit dem Virus infiziert. Eine Impfung gegen diese Erkrankung ist seit 1982 verfügbar. Impfprogramme haben dort, wo die Impfung ausreichend verfügbar ist, einen durchschlagenden Erfolg in der Reduktion von chronischer Hepatitis B gezeigt. Es gibt jedoch Teile der Welt, in denen die Impfung nicht zu einem ausreichenden Schutz führt, da die Infektion schon vor der Gabe der ersten Impfdosis geschieht oder die Impfung nicht oder nur unvollständig verabreicht wird. In Ländern mit einer hohen Prävalenz von Hepatitis B wird das Virus vor allem von Müttern auf Kinder übertragen. Kinder, die sich innerhalb ihres ersten Lebensjahres infizieren, haben hohes Risiko eine chronische Infektion zu entwickeln. Tansania, mit einer Prävalenz der chronischen Hepatitis B von 7,2% in der Allgemeinbevölkerung, gilt als Hochendemiegebiet der Erkrankung. Die Weltgesundheitsorganisation (WHO) nennt in ihrer globalen Strategie zur Elimination von viralen Hepatitiden die Prävention von Mutter-Kind-Übertragung als eine zentrale Aufgabe. Das beinhaltet unter anderem die Testung von schwangeren Frauen und die Impfung von Neugeborenen gegen HBV innerhalb von 24 Stunden nach der Geburt. Diese Maßnahmen sind jedoch in Tansania nicht implementiert. Zudem lagen zum Durchführungszeitraum der Studie nur wenige Daten zu der Prävalenz von HBV in schwangeren Frauen vor. Aus diesem Grund untersuchte die Studie die Prävalenz von Hepatitis B unter schwangeren Frauen in einem Krankenhaus der tertiären Versorgungsstufe in Mwanza, Tansania, sowie den sozio-ökonomischen Hintergrund und mögliche Risikofaktoren für eine Infektion seitens der Mütter. Ergänzend wurden verschiedene serologische und virologische Analysen des Blutes der Mütter und ihrer Kinder durchgeführt. / Chronic hepatitis B virus (HBV) infection is an important but neglected global health problem. Approximately 257 million people worldwide are chronically infected with the virus. Vaccination against this disease has been available since 1982 and vaccination programs have shown resounding success in reducing chronic hepatitis B where vaccination is sufficiently available. However, there are parts of the world where vaccination does not result in adequate protection because infection occurs before the first dose of vaccine is administered or because vaccination is not administered or is incomplete. In countries with a high prevalence of hepatitis B, the virus is transmitted primarily from mothers to their children. Children who become infected within their first year of life are at high risk of developing chronic infection. Tanzania, with a prevalence of chronic hepatitis B of 7.2% in the general population, is considered a high-endemic area for the disease. In its global strategy for the elimination of viral hepatitis, the World Health Organization (WHO) identifies prevention of mother-to-child transmission as a key task. This includes, among others, testing pregnant women and vaccinating newborns against HBV within 24 hours after birth. However, these measures have not been implemented in Tanzania. In addition, few data were available on the actual prevalence of HBV in pregnant women at the time the study was conducted. For this reason, the following study investigated the prevalence of hepatitis B among pregnant women in a tertiary care hospital in Mwanza, Tanzania, as well as the socioeconomic background and possible risk factors for infection on the part of the mothers. In addition, various serological and virological analyses of the blood of the mothers and their children were performed.

Asthma is a debilitating lung disease that affects nearly 300 million people worldwide. Environments with high humidity and subsequent mold exposure often trigger allergic asthma. Sex differences have been reported in the incidence, prevalence, and severity of asthma. B-lymphocytes are recruited in high numbers to the allergic lung in response to the inhalation of Aspergillus fumigatus mold spores (conidia). In this work, we used a mouse model of allergic fungal asthma to assess environmental humidity, sex, and B-lymphocytes in an inhalational model of allergic fungal asthma. Our results showed that animals sensitized in low humidity conditions had no airway hyperresponsiveness (AHR), inflammation, but an increase in IgG3 antibody production. Males weighed more than females, female mice had more fibrosis and produced more IgG3 Ab, but sex showed no impact on low humidity. C19+ B-lymphocytes differentially downregulated multiple genes related to allergic asthma returning the body to homeostasis.

In the world today, asthma affects more than 235 million people. The widespread prescription of inhaled corticosteroids—the current gold standard of asthma control medication—allows many asthmatics to live symptom-free and has significantly reduced the number of deaths due to asthma. However, when the disease is poorly controlled, for example due to ubiquitous exposure to airborne fungal conidia, this chronic inflammatory disease often results in lung dysfunction caused by airway architectural changes. The role of B lymphocytes in allergic asthma has been relegated to the production of IgE with relatively little being known about the trafficking of these cells in the tissues or their role(s) in the affected tissue. As a first step in ascertaining their function, the initial aim of this project was to characterize the recruitment and localization of B cells in the murine lung in response to Aspergillus fumigatus inhalation. We found that CD19+CD23+ B2 lymphocytes were recruited to the lungs after fungal inhalation and that IgA-, IgE-, IgG-producing cells localized around the large airways. The second aim of the project was to begin defining the impact that these B lymphocytes have on the allergic lung. By using mice that were deficient of conventional B cells, we were able to demonstrate that the allergic phenotype was retained, although the impact of tissue B1 B cells cannot yet be ruled out. We then investigated the ability of hyaluronic acid (HA), a major component of the extracellular matrix (ECM) generated at sites of chronic inflammation, to recruit and modulate B lymphocyte functions in allergic fungal disease. We found that B lymphocytes undergo chemotaxis in response to LMM HA, while HMM HA had little to no effect on B cell chemotaxis. Furthermore, HA-mediated B lymphocyte chemotaxis was significantly inhibited by blocking the CD44 HA receptor. We also demonstrated that LMM HA fragments elicit the production of the pro-fibrotic cytokines IL-10 and TGF-β1 by B lymphocytes. These observations suggest a previously unrecognized role for B lymphocytes and HA in the context of allergy and represent novel pathways by which B lymphocytes may contribute to airway inflammation and airway remodeling.

Since the human immunodeficiency virus (HIV) epidemic in the 1980s, great strides have been made regarding drug therapeutics, which has slowed the progression of HIV to AIDS and decreased the mortality rates in HIV patient populations. Other prevention interventions, such as pre-exposure prophylaxis (PrEP), have also contributed immensely to reducing HIV infections. However, today in many parts of the world, especially in sub-Saharan Africa, HIV is still prevalent. This demonstrates the need to focus on more long-term preventative interventions, such as vaccines. In order to do this, more research has to be conducted on the B cell adaptive immune response to HIV. This thesis research explores how the opportunistic disease tuberculosis, which is present in many HIV-positive patients, affects B cell survival in these HIV patients. Our methods section consists of CD14+ cell isolation and MDM culture experiments that we performed and subsequent planned experiments that we are yet to complete. These experiments include infecting MDM cultures with a double pseudotyped VSVg-NL43 HIV. We will also expose the MDMs to the TB antigen, lipomannan (LM), to represent HIV/TB co-infection in vitro. LM is a toll-like receptor 2 (TLR2) agonist. The MDM cultures will enable us to measure the amount of BAFF and APRIL mRNA produced in the HIV, HIV/LM, and LM MDM cultures using RT-PCR. Using a growth curve, we will observe BAFF and APRIL's effects on the survival of B cells in the different MDM cultures. We hypothesize that the TB antigen will increase B-cell survival through the BAFF system molecules in HIV patients. The results of our research will provide insights on the role TB plays in enhancing the humoral immune response in HIV-1 patients, paving the way for further research on understanding the mechanism responsible for this and consequently creating vaccine and vaccine adjuvant opportunities.

Die MP4-induzierte experimentelle autoimmune Encephalomyelitis (EAE) erlaubt eine fokussierte Betrachtung von B-Zellen, die eine wichtige Rolle bei der Pathogenese der Multiplen Sklerose (MS) spielen. Es konnte zum Beispiel gezeigt werden, dass das Vorhandensein von B-Zell-Aggregaten im zentralen Nervensystem (ZNS) von MS-Patienten mit einem aggravierten Krankheitsverlauf assoziiert war. Diese Follikel könnten dabei als ektope lymphatische Strukturen den Immunprozess aktiv gestalten und somit ein therapeutisches Ziel darstellen. In der vorliegenden Studie wurde der Effekt des Sphingosin-1-Phosphat-Rezeptor-Modulators Fingolimod (FTY720) auf die autoreaktive B-Zell-Antwort und speziell die Bildung von B-Zell-Aggregaten im Kleinhirn der MP4-EAE-Mäuse untersucht. / MP4-induced experimental autoimmune encephalomyelitis (EAE) is a mouse model of multiple sclerosis (MS), which enables focused research on B cells, important protagonists in MS pathogenesis. This study is about the impact of the sphingosine-1-phosphate receptor modulator fingolimod (FTY720) on the autoreactive B cell response and the formation of B cell aggregates and lymphoid neogenesis in the murine central nervous system (CNS).

Organisations are continuously re-engineering human resource strategy in order to attract, motivate and retain the best possible talent possible. This is a continuous process because strategies are quickly copied and replicated within industries. Share schemes have been used over a long period of time to attract, motivate and retain employees. The dawn of democracy in South Africa has seen the introduction of broad based black economic empowerment share schemes in a number of organisations. Organisations implemented these share schemes not only to improve BEE score rating but to motivate and retain employee.This research studies the impact that B-BBBEE share schemes have had on employee motivation and retention at a South African organisation. / Dissertation (MBA)--University of Pretoria, 2012. / Gordon Institute of Business Science (GIBS) / unrestricted

Orientador: Marjorie de Assis Golim / Resumo: A infecção crônica pelo vírus da hepatite B (VHB) é a principal causa de cronificação da hepatite, cirrose hepática e carcinoma hepatocelular em humanos. A vacinação contra hepatite B é essencial a saúde da população, sendo a medida de menor custo e maior eficiência para controlar o vírus. A vacina desencadeia resposta imune com produção de anticorpos contra o antígeno de superfície do VHB (anti-HBs), contudo, alguns indivíduos não desenvolvem imunidade efetiva, havendo necessidade de doses adicionais. Assim, estimular a resposta imune nos indivíduos já vacinados, porém pouco respondedores ou não respondedores previamente, poderia contribuir para o aumento da produção de anticorpos e persistência dos mesmos ao longo do tempo. Considerando o potencial imunomodulador de β-glucanas, inclusive no aumento da ativação de células T e B em resposta a antígenos, propôs-se neste estudo avaliar a influência do uso de β-glucanas como suplemento alimentar em indivíduos com imunidade não efetiva pós-vacina, que necessitassem de dose booster. Foram incluídos 46 doadores de sangue do Hemocentro de Botucatu, com idade entre 18 anos e 25 anos completos, do sexo masculino, vacinados com três doses para hepatite B na primeira infância. Aqueles que apresentaram anti-HBs<10UI/L foram considerados não imunes, sendo mantidos no estudo (n=31) e divididos em dois grupos de forma aleatória. Ambos os grupos receberam booster da vacina, sendo um grupo suplementado via oral com cápsulas de amido (n=11; pl... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Chronic hepatitis B virus (HBV) infection is the main cause of hepatitis chronification, liver cirrhosis and hepatocellular carcinoma in humans. Vaccination against hepatitis B is essential to the health of the population, being the least costly and most efficient measure to control the virus. The vaccine triggers an immune response with the production of antibodies against HBV surface antigen (Anti-HBs), however, some individuals do not develop effective immunity, requiring additional doses. Thus, stimulating the immune response in individuals who have already been vaccinated, but with little or no previous response, could contribute to increased antibody production and persistence over time. Considering the immunomodulatory potential of β-glucans, including the increased activation of T and B cells in response to antigens, it was proposed in this study to evaluate the influence of the use of βglucans as a food supplement in individuals with post-vaccine ineffective immunity , who needed a booster dose. 46 blood donors from the Hemocenter of Botucatu, aged between 18 and 25 years old, male, who received three doses of hepatitis B vaccine in childhood were included. Those who had anti-HBs <10 IU / L were considered non-immune, being maintained in the study (n = 31) and randomly divided into two groups. Both groups received a vaccine booster, one group supplemented orally with starch capsules (n = 11; placebo - 500mg / day), and the other with β-glucans (n = 20; 500mg / day) f... (Complete abstract click electronic access below) / Mestre

Magíster en Gestión y Políticas Públicas / En los últimos diez años, se ha producido un cambio en el paradigma del pensamiento económico y en las reglas jurídicas que lo regulan. Por un lado, las organizaciones y los consumidores están migrando hacia una economía más consciente y comprometida con el respeto a los derechos humanos y el cuidado del medio ambiente, pero sin dejar de lado su fin lucrativo. Las llamadas empresas híbridas o con propósitos sociales, las cuales conforman el Cuarto Sector de la economía. Sin embargo, uno de los grandes inconvenientes que han debido enfrentar este nuevo tipo de empresas, es la eventual falta de confianza y credibilidad de clientes, proveedores e inversionistas, ya que no existe un reconocimiento legal que les otorgue certeza jurídica. Bajo este contexto, se pretende evidenciar si es necesario o procedente la creación de un marco jurídico que reconozca, regule y ampare a las empresas con propósitos sociales, en particular las empresas B en Chile. Para estos efectos, la presente investigación será de tipo exploratorio descriptivo, con un enfoque cualitativo. Esto, porque el fenómeno investigado es reciente y carece de mayores antecedentes, siendo así un punto de partida para investigaciones posteriores. De esta forma, se ha recurrido a fuentes de información primarias y secundarias; comenzando con un análisis documental y posteriormente la realización de entrevistas a actores claves en la materia, cuyos resultados han sido evaluados y analizados cualitativamente. En cuanto a los resultados obtenidos, se constata que efectivamente hay una naciente conciencia social y medioambiental al momento de crear modelos de negocios, siendo los emprendimientos sociales, los más representativos dentro de las organizaciones que componen el Cuarto Sector de la economía en Chile. Por otro lado, estas empresas no poseen mayores antecedentes de los trabajos legislativos que se han elaborado en los últimos cinco años, manifestando además, un notorio desinterés e indiferencia en esta materia. Lo anterior, dado que no advierten mayores beneficios e impactos en sus modelos de negocios. Por el contrario, los principales impulsores e interesados en que se otorgue un reconocimiento por la vía legal, es la entidad que promueve el movimiento de empresas B en Chile y Latino América, señalando que se busca reconocer legalmente el aporte que generan dichas empresas y con ello migrar hacia una nueva economía. Sin embargo, no existen aún estudios empíricos y concluyentes respecto de la contribución de las empresas B, por lo que antes de elaborar un marco regulador, es necesario evidenciar el impacto real que significan dichas empresas en la economía, la sociedad y el medio ambiente.

L’hépatite B est une maladie du foie qui pose un problème majeur de santé publique. Il n’existe à ce jour aucun traitement permettant de guérir complètement de l’infection, et de nouvelles thérapies ont besoin d’être développées. Étant donné son rôle clé dans le cycle de vie du virus de l’hépatite B (VHB), la protéine core qui forme la capside virale est aujourd’hui l’une des cibles avec le plus grand potentiel thérapeutique. Nos recherches sont focalisées sur la caractérisation des capsides du VHB dans différents états conformationnels en utilisant des techniques de biochimie et de RMN du solide, afin de révéler leur conformation précise sous différentes conditions, incluant l’interaction des capsides avec des antiviraux, et la relation entre la conformation de la capside et la maturation du virus. Un système d’expression bactérienne ainsi qu’un système acellulaire de synthèse de protéine à base de germes de blé ont été établis au laboratoire pour produire les capsides, et des protocoles pour désassembler puis réassembler les capsides en présence de différents types d’ARN ont été implémentés. Des échantillons de capsides formées dans E. coli et réassemblées in vitro ont été analysés par RMN. Les différentes formes de capsides observées incluent les protéines tronquées Cp140 et Cp149, la protéine entière Cp183, phosphorylée P-Cp183, et enfin des mutants. Dans un premier temps, nous avons préparé des échantillons pour l’attribution séquentielle de la protéine core par RMN du solide. L’utilisation de la détection carbone en RMN requiert plusieurs dizaines de milligrammes d’échantillon, qui ont pu être produits en utilisant l’expressions bactérienne en milieu minimum contenant des isotopes marqués. Les attributions séquentielles ont été réalisées sur la protéine tronquée Cp149, qui donne des spectres très similaires à Cp183. Cet échantillon a également été utilisé pour identifier les différences conformationnelles entre les 4 monomères de la capside, qui sont provoquées par la symétrie icosaédrale T=4. Ensuite, l’objet principal de cette thèse a été l’investigation et la comparaison d’une large variété de capsides, dans leur forme autoassemblée dans les bactéries E. coli, ainsi que dans leur forme réassemblée. Pour le réassemblage de la protéine entière, qui requiert la présence d’acides nucléiques, nous avons testé différents types d’ARN y compris l’ARN viral prégénomique. Nous avons étudié différentes symétries (T=3 et T=4), ainsi que les états d’oxydation de la capside, et comparé les différences de conformation grâce aux perturbations de déplacements chimiques observées dans les spectres RMN. Nous avons pu identifier les acides aminés impliqués dans les changements conformationnels majeurs entre les différentes préparations. La RMN du solide en détection proton à 100 kHz a récemment émergé comme un outils important pour l’analyse de protéines produites en quantités moindres. Nous avons appliqué cette stratégie à l’analyse des capsides de Cp149 afin d’obtenir l’attribution des protons amides. La détection proton par RMN du solide peut être combinée avec succès à la synthèse des protéines en système acellulaire, qui donne de faibles rendements par rapport aux cultures en bactéries. Cette approche est particulièrement intéressante pour analyser la modulation de l’assemblage des capsides induite par la présence de drogues. Bien que nous ayons commencé à étudier l’impact de modulateurs d’assemblage par RMN en détection carbone sur des capsides formées dans E. coli et réassemblées (données préliminaires non montrées dans ce manuscrit), la détection proton ouvre la voie vers l’analyse de l’impact de ces modulateurs sur l’assemblage des protéines core directement à la sortie du ribosome / Hepatitis B is a widely spread liver disease which causes a heavy burden for human health, with 257 millions of people affected by chronic infection and about 780,000 deaths per year. Yet, infected patients can not be completely cured by current treatments using notably nucleos(t)ide analogues and interferons. In order to achieve the goal of the World Health Assembly (WHA), who wishes to eliminate hepatitis B by 2030, new therapies need to be developed. Given its critical role for the Hepatitis B virus (HBV) life cycle, the core protein (Cp) is today one of the antiviral targets with the highest potential. Our research focuses on the characterization of HBV capsids in different conformational states using biochemistry and solid-state NMR, aiming at revealing their precise conformation under different conditions, including the interaction of capsids with antivirals, and the correlation between capsid conformation and viral maturation. For sample preparation, both a bacterial expression system and a wheat germ cell-free protein synthesis system have been established in the laboratory to produce HBV capsids, and protocols to disassemble and reassemble capsids with different nucleic acids have been implemented. Both capsids preformed in E. coli and capsids reassembled in vitro were addressed to NMR studies. Different capsids forms include the truncated versions Cp140 and Cp149, the full length protein Cp183, the phosphorylated P-Cp183 and mutant forms. First, we have prepared samples for the sequential assignment of the protein using solid-state NMR. The use of carbon-13 detection asks for several tens of milligrams of sample, which were produced using labeled isotopes and bacterial expression in minimal media. Sequential assignments were performed using the truncated capsid Cp149, which showed highly similar spectra to Cp183. This sample was also used to identify conformational differences between the four different monomers in the capsid, which are due to the T=4 icosahedral symmetry. Then, the main body of the thesis is the investigation and comparison of a variety of different capsid forms, including Cp183, P-Cp183, Cp149, Cp140, another truncated form resulting in mainly T=3 icosahedral assemblies, and Cp140 C61A and Cp183 F97L mutants. We investigated all samples in both the E. coli-produced and reassembled forms, which needs for the full-length protein the presence of nucleic acids, of which we tested several, including the viral pregenomic RNA. We investigated different symmetries, as well as oxidation states of the capsid, and compared the differences via chemical shift perturbations observed in NMR spectra. We reported in a site-specific manner the major conformational changes observed between the different preparations. Proton-detected solid-state NMR at 100 kHz has recently emerged as a tool for analyzing proteins with the need of less sample amount. We have applied this strategy to the analysis of the Cp149 capsids, in order to obtain sequential assignments of the amide proton resonances. For this, deuteration of the protein in bacteria was used as well, needing adaptation of sample preparation protocols. Proton detection can be successfully combined with cell-free protein synthesis, which gives low yields compared to bacterial expression. This approach is of potential interest to analyze capsid assembly modulation induced by the presence of drugs. While we have started in the framework of this thesis to analyze the capsid in presence of different capsid assembly modulators by carbon-13 detected NMR on E. coli and reassembled capsids (preliminary results not reported here), proton detection opens the way to an analysis of the impact of capsid modulation directly on the exit of the core proteins from the ribosome, on assembly. We showed that cell-free expression combined with proton-detection solid-state NMR can be used to analyze capsid chemical shifts, and thus in future work the conformational modulations