Impact of Hemoglobin Levels and Anemia on Mortality in Acute Stroke : Analysis of UK Regional Registry Data, Systematic Review, and Meta‐Analysis

Funding Sources The NNUH Stroke and TIA Register is maintained by the NNUH NHS Foundation Trust Stroke Services and data management for this study is supported by the NNUH Research and Development Department through Research Capability Funds.

Étude de la cytolyse autologue et du mimétisme immunitaire dans l'hépatite autoimmune de type 2

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Regulation of lipocalin 2 (Lcn2) gene expression by iron stores, anemia and inflammation

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Étude des autoanticorps marqueurs de l'hépatite autoimmune présents chez les patients infectés de façon chronique par le virus de l'hépatite C

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Study of Rgmc regulation by iron levels, anemia, inflammation and hypoxia

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Rad18 confers hematopoietic progenitor cell DNA damage tolerance independently of the Fanconi Anemia pathway in vivo.

In cultured cancer cells the E3 ubiquitin ligase Rad18 activates Trans-Lesion Synthesis (TLS) and the Fanconi Anemia (FA) pathway. However, physiological roles of Rad18 in DNA damage tolerance and carcinogenesis are unknown and were investigated here. Primary hematopoietic stem and progenitor cells (HSPC) co-expressed RAD18 and FANCD2 proteins, potentially consistent with a role for Rad18 in FA pathway function during hematopoiesis. However, hematopoietic defects typically associated with fanc-deficiency (decreased HSPC numbers, reduced engraftment potential of HSPC, and Mitomycin C (MMC) -sensitive hematopoiesis), were absent in Rad18(-/-) mice. Moreover, primary Rad18(-/-) mouse embryonic fibroblasts (MEF) retained robust Fancd2 mono-ubiquitination following MMC treatment. Therefore, Rad18 is dispensable for FA pathway activation in untransformed cells and the Rad18 and FA pathways are separable in hematopoietic cells. In contrast with responses to crosslinking agents, Rad18(-/-) HSPC were sensitive to in vivo treatment with the myelosuppressive agent 7,12 Dimethylbenz[a]anthracene (DMBA). Rad18-deficient fibroblasts aberrantly accumulated DNA damage markers after DMBA treatment. Moreover, in vivo DMBA treatment led to increased incidence of B cell malignancy in Rad18(-/-) mice. These results identify novel hematopoietic functions for Rad18 and provide the first demonstration that Rad18 confers DNA damage tolerance and tumor-suppression in a physiological setting.

IL-10-producing Regulatory B Cell Development in Human Autoimmune Disease

B cell abnormalities contribute to the development and progress of autoimmune disease. Traditionally, the role of B cells in autoimmune disease was thought to be predominantly limited to the production of autoantibodies. Nevertheless, in addition to autoantibody production, B cells have other functions potentially relevant to autoimmunity. Such functions include antigen presentation to and activation of T cells, expression of costimulatory molecules and cytokine production. Recently, the ability of B cells to negatively regulate cellular immune responses and inflammation has been described and the concept of “regulatory B cells” has emerged. A variety of cytokines produced by regulatory B cell subsets have been reported with interleukin-10 (IL-10) being the most studied. IL-10-producing regulatory B cells predominantly localize within a rare CD1dhiCD5+ B cell subset in mice and the CD24hiCD27+ B cell subset in adult humans. This specific IL-10-producing subset of regulatory B cells have been named “B10 cells” to highlight that the regulatory function of these rare B cells is primarily mediated by IL-10, and to distinguish them from other regulatory B cell subsets that regulate immune responses through different mechanisms. B10 cells have been studies in a variety of animal models with autoimmune disease and clinical settings of human autoimmunity. There are many unsolved questions related to B10 cells including their surface phenotype, their origin and development in vivo, and their role in autoimmunity.

In Chapter 3 of this dissertation, the role of the B cell receptor (BCR) in B10 cell development is highlighted. First, the BCR repertoire of mouse peritoneal cavity B10 cells is examined by single cell sequencing; peritoneal cavity B10 cells have clonally diverse germline BCRs that are predominantly unmutated. Second, mouse B10 cells are shown to have higher frequencies of λ+ BCRs compared to non-B10 cells which may indicate the involvement of BCR light chain editing early in the process of B10 cell development in vivo. Third, human peripheral blood B10 cells are examined and are also found to express higher frequencies of λ chains compared to non-b10 cells. Therefore, B10 cell BCRs are clonally diverse and enriched for unmutated germline sequences and λ light chains.

In Chapter 4 of this dissertation, B10 cells are examined in the healthy developing human across the entire age range of infancy, childhood and adolescence, and in a large cohort of children with autoimmunity. The study of B10 cells in the developing human documents a massive transient expansion during middle childhood when up to 30% of blood B cells were competent to produce IL-10. The surface phenotype of pediatric B10 cells was variable and reflective of overall B cell development. B10 cells down-regulated CD4+ T cell interferon-gamma (IFN-γ) production through IL-10-dependent pathways and IFN-γ inhibited whereas interleukin-21 (IL-21) promoted B cell IL-10 competency in vitro. Children with autoimmunity had a contracted B10 cell compartment, along with increased IFN-γ and decreased IL-21 serum levels compared to age-matched healthy controls. The decreased B10 cell frequencies and numbers in children with autoimmunity may be partially explained by the differential regulation of B10 cell development by IFN-γ and IL-21 and alterations in serum cytokine levels. The age-related changes of the B10 cell compartment during normal human development provide new insights into immune tolerance mechanisms involved in inflammation and autoimmunity.

These studies collectively demonstrate that BCR signals are the most important early determinant of B10 cell development in vivo, that human B10 cells are not a surface phenotype defined developmental B cell subset but a functionally defined regulatory B cell subset that regulates CD4+ T IFN-γ production through IL-10-dependent pathways and that human B10 cell development can be regulated by soluble factors in vivo such as the cytokine milieu. The findings of these studies provide new insights into immune tolerance mechanisms involved in human autoimmunity and the potent effects of IL-21 on human B cell IL-10 competence in vitro open new horizons in the development of autologous B10 cell-based therapies as an approach to treat human autoimmune disease in the future.

Étude de la cytolyse autologue et du mimétisme immunitaire dans l'hépatite autoimmune de type 2

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Regulation of lipocalin 2 (Lcn2) gene expression by iron stores, anemia and inflammation

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Étude des autoanticorps marqueurs de l'hépatite autoimmune présents chez les patients infectés de façon chronique par le virus de l'hépatite C

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Study of Rgmc regulation by iron levels, anemia, inflammation and hypoxia

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

INVESTIGATING THE MECHANISM OF AUTOIMMUNE DISEASE ASSOCIATED-LQTS

The human ether-a-go-go-related gene (hERG) protein passes the rapidly activating delayed rectifier potassium channel (IKr), and malfunction of hERG protein/IKr is the primary cause of acquired long QT syndrome (LQTS). Autoimmune diseases are significantly correlated with prolonged QT intervals, for which autoantibodies have been implicated. The anti-Ro52 autoantibody is the most frequently evaluated, and importantly has been correlated with prolonged QT intervals. Pathological anti-Ro52-hERG interactions have been discussed as a mechanism for autoimmune disease-related LQTS. However, the mechanism is unclear, and it does not explain LQTS in autoimmune diseases which do not commonly express anti-Ro52. In this thesis, I investigated the effects of anti-Ro52 on hERG/IKr function. Through Western blot analysis, whole-cell patch-clamp, and immunofluorescence, I show that anti-Ro52 chronically (12 h) reduced hERG protein expression and hERG current by over 50%, but did not acutely block the channel. My work revealed a novel mechanism in which the Fc portion of anti-Ro52 interacts with the extracellular S5-pore linker of the channel to induce internalization through a tyrosine phosphorylation dependent pathway. This phenomenon extends beyond anti-Ro52 IgG, as other IgG, regardless of their antigen binding specificity, have the potential to reduce hERG expression/current. Rather, the ability of IgG to reduce hERG expression and current is dependent on the IgG subclass, as we show mouse IgG2A was the only mouse IgG subclass which reduced hERG expression. These results provide a novel explanation for autoimmune disease associated LQTS. It also has implications in the development of safe monoclonal antibody drugs.

Achados fundoscópicos em crianças portadoras de anemia falciforme no estado do Rio Grande do Norte

Detectar os principais achados fundoscópicos em crianças portadoras de hemoglobinopatias falciformes. Métodos: Foram estudados 26 pacientes com hemoglobinopatias falciformes, no Serviço de Oftalmologia do Hospital Universitário Onofre Lopes, Natal, RN, que foram submetidos a protocolo de pesquisa pré-estabelecido. Os resultados foram avaliados estatisticamente pelo teste qui-quadrado. Resultados: A idade média foi de 10,6 anos, com acuidade visual igual ou melhor que 20/25 na maioria, excetuando-se 3 olhos, que apresentavam outras doenças associadas. O tipo mais freqüente foi o SS com 57,7% (15/26) dos casos, seguido pelos SC e SA com 15,4% (4/26) cada, e pelo S-Thal com 11,5% (3/26). A freqüência da retinopatia por células falciformes foi maior após os 10 anos de idade, sendo mais freqüente, em valores relativos, no tipo S-Thal (100% dos casos) e, em valores absolutos, no tipo SS (9 casos). Os dois achados mais comuns foram tortuosidade venosa (12/26) e “black sunburst” (7/26). Conclusões: Observamos que a incidência de retinopatia por células falciformes aumentou após os 10 anos de idade e não evidenciamos achados da doença proliferativa. Portanto, enfatizamos a necessidade do exame oftalmológico precoce nos portadores de anemia falciforme, como forma de prevenir futuras complicações oculares

Anemia en ovejas de desarrollo en Finca Santa Rosa durante el período Junio –Julio 2014

Con el objetivo de elaborar un plan sanitario que prevenga el síndrome anémico en el hato ovino de la Facultad de Ciencia Animal - UNA. Se determinó la prevalencia de esta patología en los ovinos en desarrollo, Analizando los niveles de infestación ( NI ) de las especies parasitarias y evaluando los valores de hematocrito en relación con la carga gastro - parasitaria. Se tomaron 18 muestras biológicas de heces fecales y sangre, antes de la desparasitación y 20 días después, en el periodo de Junio – Julio 2014, se utilizó la técnica de Sheather, se determinó Hematocrito y Hemoglobina , Los datos s e analizaron a través del estudio epidemiológico descriptivo y analítico utilizando diferentes técnicas de laboratorio y método estadístico de correlación de variables cuantitativas de Pearson . En el primer y segundo muestreo se identificaron los parásitos Haemonchus sp, Cooperia sp, Strongylus sp, Coccidia sp, Bunostomum sp y Moniezia sp . Al primer muestreo la variable prevalencia de síndrome anémico del hato ovino es del 50% y el 100% de los animales analizados presentaron Strongylus sp, Haemonchus sp, Co ccidia sp, Bunostomum sp y Moniezia sp, y el 72,2% presentaron Cooperia sp , presentaron NI Alto 77.7% afectados con Haemonchus sp, 16.6% Strongylus sp, y un 11.1% para las especies de Cooperia sp, Coccidia sp y Moniezia sp. , NI Moderado, Moniezia sp y C occidia sp , un 88.8%, Strongylus sp 83.3%, Bunostomum sp y Haemonchus sp 22.2% y Cooperia sp 11.1%, NI Leve, el 77.7% con Bunostomum sp y el 50% presentaron Cooperia sp. Al segundo muestreo 20 días después del tratamiento, el valor de hematocrito, e staban en los rangos de 22 - 38%. Los niveles de infestación variaron, presentando NI Alta , para Moniezia sp con 22.2%, aumentado su carga parasitaria en relación con el primer muestreo . Se observó la disminución de las cargas parasitarias de las especies Ha emonchus sp con 16.6%, Strongylus sp y Coccidia sp 5.5%.En el NI Moderada , Coccidia sp , mantuvo el 88.8%. Strongylus sp aumentó con 88.8%, Haemonchus sp 83.3%. Las cargas de Moniezia sp , prevalecieron con el 77.7%. Cooperia sp , se presentó con el 50%, B onostomus sp , 27.7%. NI Leve , encontramos el 44.4% de la población con Bunostomum sp y un 5.5% con Cooperia sp y Coccidia sp. De la relación existente entre la presencia de los parásitos y los valores de hematocrito, las combinaciones parasitarias siguient es fueron significativos con P= 0.67, <0.0022 para Cooperia sp y Haemonchus sp , P= 0.65, <0.0036 Cooperia sp con Bunostomum sp , P= 0.62, <0.0060 Cooperia sp con Strongylus sp , P= 0.50, <0.0353 Strongylus sp con Moniezia sp y P= 0.64 <0.0043 para Haemon chus sp con Bunostomum sp. Las parasitosis gastrointestinales son un factor importante de las causas del síndrome anémico, ya que la relación de los valores de hematocritos con la combinación de diferentes especies de parásitos fue significativa y que con la utilización de fármacos antihelmínticos de uso continuo se encontraron cargas parasitarias, con niveles de infestación de alto a moderado .