Spelling suggestions: "subject:"immunoglobulin E"" "subject:"lmmunoglobulin E""
471 |
Avaliação da imunoglobulina A, células TCD4+ e TCD8+ na mucosa vaginal relacionadas à infecção pelo papilomavírus humano e à síndrome da imunodeficiência humana / Evaluation of immunoglobulin A, TDC4+ and TCD8+ cells in the vaginal mucosa related to the infection by the human papillomavirus and to the human immunodeficiency syndromeMaria Cristina Gonçalves de Almeida Meniconi 19 October 2007 (has links)
A infecção pelo HPV é correlacionada com processos neoplásicos ginecológicos e vários estudos têm sido conduzidos sobre a influência da resposta imune interferindo na oncogênese. A epidemia do HIV e as doenças sexualmente transmissíveis, inicialmente concentradas em grupos de riscos masculinos, apresentam atualmente, uma maior prevalência em mulheres, o que tem aumentado o número de infecção concomitante HPV e HIV. O estudo da resposta imune in situ é uma ferramenta essencial para a compreensão destes processos, medindo diretamente no órgão alvo a resposta imune existente. Nas mucosas, a IgA é a principal responsável pelo controle de várias infecções. As células TCD4+ e TCD8+ têm como principal função auxiliar a resposta imune e as TCD8+ agem também como citotóxicos.Neste trabalho, estudou-se 81 biópsias de vagina de mulheres que foram distribuídas em três grupos: I - com AIDS e HPV (55); II - com infecção pelo HPV e HIV negativa (13); III - HIV e HPV negativas (13). Foram realizados: exame colposcópico, avaliação semiquantitativa dos achados histológicos, hibridização in situ, estudo imuno-histoquímico para IgA, TCD4+ e TCD8+. Observou-se que o padrão citológico suspeito de NIVA mostrou relacionar-se com a quantidade tecidual de células TCD8+ e a infecção pelo HPV, mas não com o número de células TCD4+ ou IgA. A análise colposcópica definiu quadros que tiveram relação significativa com as lesões histopatológicas encontradas e com a infecção pelo HPV, mas sem relação com a co-infecção pelo HIV/HPV, uso de terapia anti-retroviral ou número de TCD4+ circulantes. Verificou-se que a expressão in situ de IgA nas biópsias de vagina de pacientes com vaginite crônica inespecífica, infecção pelo HPV ou co-infecção HPV/HIV não é um parâmetro relevante para discriminar a resposta imune humoral protetora entre esses grupos de pacientes e que o padrão citológico inflamatório é menos expressivo nos casos de infecção pelo HPV que nos casos de vaginite crônica não especifica. Outrossim, a imunidade adquirida revelou maior expressão de células TCD8+ in situ em casos de NIVA que nas vaginites crônicas não relacionadas ao HIV ou HPV e tendência a expressão de maior número de linfócitos TCD4+ em casos de NIVA e condiloma. Por outro lado, as alterações de proliferação epitelial tais como hiperqueratose e metaplasia escamosa epidermóide tiveram relação com NIVA de alto grau e condiloma. Os achados de acantose e hiperqueratose relacionaram-se à infecção pelo HIV/HPV, assim como alterações colposcópicas mais acentuadas. / The infection by HPV (Human papillomavirus) is correlated to gynecologic neoplasic processes and several studies have been performed on the influence of the immune response with interference in the oncogenesis. The HIV (Human Immunodeficiency Virus) epidemic and the sexually-transmitted diseases, initially concentrated in risk groups of men, currently show a higher prevalence in women, which has been increasing the number of concurrent HPV and HIV infection. The study of the in situ immune response is an essential tool for the understanding of these processes, measuring the existing immune response directly in the target organ. In the mucosae, IgA (Immunoglobulin A) is the main responsible for the control of several infections. The main function of the TCD4+ and TCD8+ cells (T cells that express CD4 and CD8) is to help the immune response and TCD8+ cells also play a cytotoxic role. In this work, 81 vagina biopsies have been studied, of women distributed into three groups: I - with AIDS and HPV (55); II - with HPV infection and HIV negative (13); III - HIV and HPV negative (13). It was performed: colposcopic examination, semi-quantitative evaluation of the histological findings, in situ hybridization, immunochemical study for IgA, TCD4+ and TCD8+. It was observed that the suspect cytological pattern of VAIN (Vaginal intraepithelial neoplasia) showed to be related to the total tissue quantity of TCD8+ cells and the HPV infection, but not to the number of TCD4+ cells or IgA. The colposcopic analysis defined conditions that have been significantly related to the histopathological lesions found and to the HPV infection, but not related to the HIV/HPV co-infection, use of antiretroviral therapy or number of TCD4+ in circulation. It was observed that the in situ expression of IgA in the vagina biopsies of patients experiencing nonspecific chronic vaginitis, HPV infection or HPV/HIV co-infection is not a relevant parameter to distinguish the protective humoral immune response among those patient groups and that the inflammatory cytological pattern is less expressive in the cases of HPV infection than in the cases of nonspecific chronic vaginitis. In addition, the acquired immunity showed a higher in situ expression of TCD8+ cells in VAIN cases than in the chronic vaginitis not related to HIV or HPV and the tendency to the expression of a higher number of TCD4+ lymphocytes in VAIN and condyloma cases. On the other hand, the alterations in the epithelial proliferation, such as hyperkeratosis and epidermoid squamous metaplasia were related to high-grade VAIN and condyloma. The findings of acanthosis and hyperkeratosis were related to the HIV/HPV infection, as well as the most remarkable colposcopic alterations.
|
472 |
Identificação de peptídeos de Escherichia coli capazes de inibir a própria fagocitose em sepse / Identification of Escherichia coli peptides that can inhibit its own phagocytosis in sepsisJaqueline Beppler 22 May 2015 (has links)
Introdução: Sepse é uma síndrome complexa definida por resposta inflamatória sistêmica, de origem infecciosa e caracterizada por manifestações múltiplas que podem determinar disfunção ou falência de um ou mais órgãos ou sistemas. É a principal causa de morte em unidades de terapia intensiva em pacientes críticos e tem representado uma fonte constante de preocupação para os sistemas de saúde em todo o mundo, devido, principalmente, às taxas elevadas de morbimortalidade. O tratamento da sepse é um desafio e continua a ser uma tarefa difícil devido a inúmeros fatores interferentes. Um estudo do nosso grupo demonstrou que a Escherichia coli (E. coli) é capaz de se ligar CD16 de um modo independente de opsonina, levando a um aumento na resposta inflamatória e a inibição da sua própria fagocitose, por conseguinte, procurou-se identificar os peptídeos no proteoma da E. coli envolvidos neste cenário. Metodologia: Utilizando a metodologia de Phage Display, que consiste numa técnica de clonagem, que permite a expressão de diversas sequências de peptídeos na superfície de bacteriófagos, nós identificamos 2 peptídeos que obtiveram interação com CD16. Após a seleção dos peptídeos identificamos uma proteína de membrana de E.coli que possui alta similaridade com um de nossos peptídeos selecionados. Nós acreditamos que esta proteína de membrana possa estar envolvida no processo de evasão imune desenvolvida pela E.coli e parece ser um forte candidato como uma nova opção terapêutica para controlar infecções por E. coli. Conclusão: A identificação de proteínas capazes de induzir inibição de fagocitose, através do receptor CD16, pode ser usada como uma nova forma de tratamento da sepse, assim como explorada no tratamento de doenças autoimunes / Introduction: Sepsis is a complex syndrome defined by a systemic inflammatory response of infectious origin and characterized by multiple manifestations that can determine dysfunction/failure of one or more organs and systems. It is the leading cause of death in intensive care units and represents a major health problem around the world, mainly due to its high mortality and morbidity rates. The treatment of sepsis is challenging and remains a difficult task due to numerous interfering factors. A study from our group demonstrated that Escherichia coli (E. coli) is able to bind CD16 in an opsoninindependent manner, leading to an increase in the inflammatory response and inhibition of its own phagocytosis, therefore we sought to identify the peptides in the E. coli proteome involved in this scenario. Methods and Results: Using the Phage Display technique, which is a cloning technique that allows the expression of various peptide sequences on the surface of bacteriophages (phages) and selecting these on the basis of affinity for a target molecule, we identified two peptides that interact with CD16. Next, using bioinformatic tools, we found an E. coli membrane protein that has high similarity with one of our selected peptides. We believe this membrane protein is involved in the process of immune evasion developed by E. coli and it is a strong candidate as a new therapeutic option to control E. coli infections. Conclusion: The identification of proteins capable of inducing inhibition of phagocytosis through the CD16 receptor, can be used as a new treatment of sepsis, as well as exploited in the treatment of autoimmune diseases
|
473 |
Níveis e avidez de anticorpos IgG específicos para a porção de 19kDa da região C-terminal da proteína-1 de superfície de merozoítos de P. vivax (MSP1 19) em grupos populacionais expostos à malária / Level and avidity of specific IgG antibodies to C-terminal 19kDa of Plasmodium vivax merozoite surface protein 1 (MSP119) in population groups exposed to malariaKudó, Mônica Eriko 15 February 2007 (has links)
O objetivo deste trabalho foi estudar a resposta imune, quanto ao nível e à avidez dos anticorpos IgG, dirigidos contra o antígeno recombinante derivada da Proteína 1 de Superfície de Merozoíto de Plasmodium vivax (PvMSP119) em indivíduos residentes em diferentes áreas endêmicas do Brasil, empregando o teste ELISA. Para tanto, foram estudadas amostras de indivíduos expostos à malária, infectados ou não e em acompanhamento terapêutico. Na padronização das condições de reação, obteve-se uma sensibilidade de 95,00% em amostras de pacientes com gota espessa positiva para P. vivax e uma especificidade de 99,50% em amostras de indivíduos saudáveis e com outras patologias. Entre as amostras de pacientes com P. falciparum, 7,14% foram reagentes. O estudo dos diferentes grupos de pacientes com malária vivax mostrou haver diferença significante entre os primo infectados e aqueles com episódios anteriores de malária, sendo os níveis (IR) e avidez (IA) de IgG mais baixos nos primo infectados, embora os níveis de anticorpos já estivessem elevados nesses pacientes. A predominância de IgG anti-PvMSP119 de baixa avidez nos pacientes primo infectados por P. vivax, sugere um baixo grau de proteção, mesmo na presença de elevados níveis de anticorpos observados já no início da infecção. A análise dos indivíduos não infectados mostrou haver uma associação negativa dos resultados de IR com o tempo decorrido desde o último episódio de malária e associação positiva com o número de malárias anteriores. Em relação aos IA houve associação positiva com ambos os parâmetros, nos pacientes que haviam tido malária até, no máximo, seis meses antes da coleta. Entre os pacientes que haviam apresentado episódios de malária anteriores, observaram-se níveis mais baixos de anticorpos IgG anti-PvMSP119 em indivíduos com alta exposição à malária, quando comparados a moradores de áreas com baixa transmissão. Em relação à avidez, foram encontrados índices mais elevados nas áreas de maior transmissão. Considerando-se o município de Alta Floresta, nas regiões de garimpo e próximas à mata, obtiveram-se altos índices de positividade com níveis e avidez dos anticorpos mais elevados que nas demais regiões. Não foi observada correlação entre níveis e avidez dos anticorpos IgG anti-PvMSP119. / The aim of this work was to study the level and avidity of IgG antibodies specific to Plasmodium vivax using the recombinant protein corresponding to 19kDa C-terminal of the merozoite surface protein 1 region (PvMSP119) in individuals living in distinct malaria endemic areas, using ELISA test. Thus, samples from individuals exposed to malaria, with patent infection or not were evaluated. The reaction conditions were standardized, yielding 95.00% sensitivity with sera from P. vivax infected patients and 99.50% specificity with sera from individuals non-exposed to P. vivax malaria. Just 7.14% of patient samples with P. falciparum malaria reacted to PvMSP119. The investigation of different groups of vivax malaria patients showed significant differences between patients with primo infection and those with past malaria episodes. The levels and avidity of IgG were lower in primo infected ones. The predominance of low avidity IgG in P. vivax primo infected patients may suggest low grade of protection even in high level antibody sera. The analysis of non-infected subjects showed a negative association of IgG levels and time elapsed since last malaria episode, and a positive association to the number of malaria episodes. For individuals who had had last malaria episode till maximum six months before the collecting of blood samples, avidity indexes showed positive association for both parameters described before. Individuals sporadically exposed to malaria transmission (Belém group) and who experienced their last episode by P. vivax had significant high levels and proportions of specific antibodies when compared to subjects continuously exposed (Alta Floresta group). Otherwise, higher avidity levels were detected in high transmission areas. In god mines and forest areas of Alta Floresta, higher IgG and avidity levels were obtained, as compared to the other regions of the municipality. No correlation was observed between anti-PvMSP119 IgG levels and avidity levels.
|
474 |
Avaliação da imunoglobulina A, células TCD4+ e TCD8+ na mucosa vaginal relacionadas à infecção pelo papilomavírus humano e à síndrome da imunodeficiência humana / Evaluation of immunoglobulin A, TDC4+ and TCD8+ cells in the vaginal mucosa related to the infection by the human papillomavirus and to the human immunodeficiency syndromeMeniconi, Maria Cristina Gonçalves de Almeida 19 October 2007 (has links)
A infecção pelo HPV é correlacionada com processos neoplásicos ginecológicos e vários estudos têm sido conduzidos sobre a influência da resposta imune interferindo na oncogênese. A epidemia do HIV e as doenças sexualmente transmissíveis, inicialmente concentradas em grupos de riscos masculinos, apresentam atualmente, uma maior prevalência em mulheres, o que tem aumentado o número de infecção concomitante HPV e HIV. O estudo da resposta imune in situ é uma ferramenta essencial para a compreensão destes processos, medindo diretamente no órgão alvo a resposta imune existente. Nas mucosas, a IgA é a principal responsável pelo controle de várias infecções. As células TCD4+ e TCD8+ têm como principal função auxiliar a resposta imune e as TCD8+ agem também como citotóxicos.Neste trabalho, estudou-se 81 biópsias de vagina de mulheres que foram distribuídas em três grupos: I - com AIDS e HPV (55); II - com infecção pelo HPV e HIV negativa (13); III - HIV e HPV negativas (13). Foram realizados: exame colposcópico, avaliação semiquantitativa dos achados histológicos, hibridização in situ, estudo imuno-histoquímico para IgA, TCD4+ e TCD8+. Observou-se que o padrão citológico suspeito de NIVA mostrou relacionar-se com a quantidade tecidual de células TCD8+ e a infecção pelo HPV, mas não com o número de células TCD4+ ou IgA. A análise colposcópica definiu quadros que tiveram relação significativa com as lesões histopatológicas encontradas e com a infecção pelo HPV, mas sem relação com a co-infecção pelo HIV/HPV, uso de terapia anti-retroviral ou número de TCD4+ circulantes. Verificou-se que a expressão in situ de IgA nas biópsias de vagina de pacientes com vaginite crônica inespecífica, infecção pelo HPV ou co-infecção HPV/HIV não é um parâmetro relevante para discriminar a resposta imune humoral protetora entre esses grupos de pacientes e que o padrão citológico inflamatório é menos expressivo nos casos de infecção pelo HPV que nos casos de vaginite crônica não especifica. Outrossim, a imunidade adquirida revelou maior expressão de células TCD8+ in situ em casos de NIVA que nas vaginites crônicas não relacionadas ao HIV ou HPV e tendência a expressão de maior número de linfócitos TCD4+ em casos de NIVA e condiloma. Por outro lado, as alterações de proliferação epitelial tais como hiperqueratose e metaplasia escamosa epidermóide tiveram relação com NIVA de alto grau e condiloma. Os achados de acantose e hiperqueratose relacionaram-se à infecção pelo HIV/HPV, assim como alterações colposcópicas mais acentuadas. / The infection by HPV (Human papillomavirus) is correlated to gynecologic neoplasic processes and several studies have been performed on the influence of the immune response with interference in the oncogenesis. The HIV (Human Immunodeficiency Virus) epidemic and the sexually-transmitted diseases, initially concentrated in risk groups of men, currently show a higher prevalence in women, which has been increasing the number of concurrent HPV and HIV infection. The study of the in situ immune response is an essential tool for the understanding of these processes, measuring the existing immune response directly in the target organ. In the mucosae, IgA (Immunoglobulin A) is the main responsible for the control of several infections. The main function of the TCD4+ and TCD8+ cells (T cells that express CD4 and CD8) is to help the immune response and TCD8+ cells also play a cytotoxic role. In this work, 81 vagina biopsies have been studied, of women distributed into three groups: I - with AIDS and HPV (55); II - with HPV infection and HIV negative (13); III - HIV and HPV negative (13). It was performed: colposcopic examination, semi-quantitative evaluation of the histological findings, in situ hybridization, immunochemical study for IgA, TCD4+ and TCD8+. It was observed that the suspect cytological pattern of VAIN (Vaginal intraepithelial neoplasia) showed to be related to the total tissue quantity of TCD8+ cells and the HPV infection, but not to the number of TCD4+ cells or IgA. The colposcopic analysis defined conditions that have been significantly related to the histopathological lesions found and to the HPV infection, but not related to the HIV/HPV co-infection, use of antiretroviral therapy or number of TCD4+ in circulation. It was observed that the in situ expression of IgA in the vagina biopsies of patients experiencing nonspecific chronic vaginitis, HPV infection or HPV/HIV co-infection is not a relevant parameter to distinguish the protective humoral immune response among those patient groups and that the inflammatory cytological pattern is less expressive in the cases of HPV infection than in the cases of nonspecific chronic vaginitis. In addition, the acquired immunity showed a higher in situ expression of TCD8+ cells in VAIN cases than in the chronic vaginitis not related to HIV or HPV and the tendency to the expression of a higher number of TCD4+ lymphocytes in VAIN and condyloma cases. On the other hand, the alterations in the epithelial proliferation, such as hyperkeratosis and epidermoid squamous metaplasia were related to high-grade VAIN and condyloma. The findings of acanthosis and hyperkeratosis were related to the HIV/HPV infection, as well as the most remarkable colposcopic alterations.
|
475 |
Evaluation von KIR-Liganden Inkompatibilität bei unverwandten Knochenmark-/ Stammzelltransplantationen / Role of KIR ligand incompatibility in hematopoietic stem cell transplantation using unrelated donorsMartin, Hilmar 17 July 2005 (has links) (PDF)
We performed a retrospective study in 185 patients with myelogenous leukemias who had received hematopoietic cells from unrelated donors. The aim of this study was to answer the question wether the benefit of KIR ligand incompatibility seen in haploidentical tranplantations can also be seen using unrelated donors. We could not detect a significant difference in survival between patients with a KIR ligand incompatibility and those with either fully matched or partially mismatched unrelated donors in this patient cohort. / In der Therapie von Leukämien ist die Knochenmark- bzw. Stammzelltransplantation eine tragende Säule. Für den Transplantationserfolg ist eine Übereinstimmung der Haupthistokompatibilitätsantige (HLA-Antigene der Klassen I und II) zwischen Spender und Empfänger von zentraler Bedeutung. Diese Notwendigkeit ergibt sich aus der sogenannten MHC-Restriktion in der T-Zellrezeptorerkennung. Ob auch NK-Zellrezeptoren und deren Liganden in der Spenderauswahl berücksichtigt werden sollten, ist bisher unzureichend untersucht. Insbesondere trifft das für die KIR-Rezeptoren zu, die wie die T-Zellrezeptoren ebenfalls HLA-Antigene als Liganden besitzen. Velardi et al. haben 2002 erstmalig gezeigt, daß in der Therapie myeloischer Leukämien die Transplantation von Blutstammzellen verwandter Spender mit KIR-Liganden-Inkompatibilität von klinischem Vorteil ist. Ob KIR-Liganden-Inkompatibilität auch bei Knochenmark-/ Stammzelltransplantationen Unverwandter Bedeutung erlangen könnte, war zu Studienbeginn offen und blieb auch infolge diskrepanter Untersuchungsergebnisse von verschiedenen Arbeitsgruppen im Verlauf der Studie widersprüchlich. Im Rahmen dieser Arbeit wurde diese Fragestellung, die auch Teil einer internationalen Studie war, an 185 Spender-Empfänger-Paaren retrospektiv untersucht. Dabei wurde bei den Paaren einerseits die KIR-Liganden-Kompatibilität auf der Grundlage der HLA-C-Supertypen erschlossen (nach Velardi et al.). Andererseits konnte sie im internationalen Studienprogramm direkt aus dem KIR-Genotyp des Spenders und dem HLA-C-Supertyp des Empfängers ermittelt werden. Die Untersuchungen ergaben folgende Resultate: bei Vorliegen von KIR-Liganden-Inkompatibilität hat die Verwendung von ATG als Bestandteil der GvHD-Prophylaxe keinen Einfluß auf das klinische Ergebnis. Die Vermutungen von Giebel et al. wurden damit nicht gestützt. Die Bestimmung des KIR-Liganden-Status mit Hilfe der Rückschlußmethode allein aus dem HLA-Typ ist unzuverlässig. Für eine exakte Differenzierung ist die gleichzeitige KIR-Genotypisierung erforderlich. KIR-Liganden-Inkompatibilität ist bei unverwandten Knochenmark-/ Stammzelltransplantationen nicht von klinischem Vorteil. Auch ein gezieltes Aussuchen HLA-C-inkompatibler Spender auf der Grundlage einer KIR-Genotypisierung stellt derzeit keine therapeutische Option dar.
|
476 |
Stress and the Offspring : Adaptive Transgenerational Effects of Unpredictability on Behaviour and Gene Expression in Chickens (<em>Gallus gallus</em>)Nätt, Daniel January 2008 (has links)
<p>Environmental stress has shown to affect both the exposed individuals and the development of their offspring. Generally, it is thought that the stressed organism responds to stress by trying to adapt to it. This thesis investigates possible evolutionary consequences of cross-generational transmissions of stress, where the parent has been stressed but the offspring has not. In two studies we have exposed chicken parents of different breeds to an unpredictable circadian light rhythm, to investigate the influence of genetic background on the transmission of behaviour and patterns of genome-wide gene expression across generations. In Paper I, we can show that the domesticated chicken, by means of epigenetic factors, transmit their behaviours as well as their gene expression profiles to their offspring to a higher extent than their wild ancestor, the red junglefowl. Furthermore, in Paper II, even though the offspring never experienced the stress or had any contact with their stressed parents, they seemed to have adapted to it, which suggests that the parents might have prepared (or pre-adapted) them for living in the unpredictable environment. Additionally, eggs of stressed hens showed increased levels of estradiol that might have affected gene expression of specific immune genes, which were up-regulated in the offspring of stressed parents. It is possible that the traditional distinction between stress responses and evolutionary adaptation may be reevaluated, since our results indicate that they could be parts of the same evolutionary event.</p>
|
477 |
Detection of new allotypic variants of bovine antibody λ-light chain and IgG-heavy chain constant regions / Detection of new allotypic variants of bovine antibody λ-light chain and IgG-heavy chain constant regionsAboelhassan, Dalia 03 February 2012 (has links)
No description available.
|
478 |
Using student difficulties to identify and model factors influencing the ability to interpret external representations of IgG-antigen binding.Schonborn, Konrad Janek. January 2005 (has links)
Scientific external representations (ERs), such as diagrams, images, pictures, graphs and
animations are considered to be powerful teaching and learning tools, because they assist
learners in constructing mental models of phenomena, which allows for the comprehension
and integration of scientific concepts. Sometimes, however, students experience difficulties
with the interpretation of ERs, which· has a negative effect on their learning of science,
. . including biochemistry. Unfortunately, many educators are not aware of such student
difficulties and make the wrong assumption that what they, as experts, consider to be an
educationally sound ER will necessarily promote sound. learning and understanding among
novices. On the contrary, research has shown that learners who engage in the molecular
biosciences can experience considerable problems interpreting, visualising, reasoning and
learning with ERs of biochemical structures and processes, which are both abstract and often
represented by confusing computer-generated symbols and man-made markings.
The aim of this study was three-fold. Firstly, to identify and classify students' conceptual and
reasoning difficulties with a selection of textbook ERs representing· IgG structure and
function. Secondly, to use these difficulties to identify sources of the difficulties and,
therefore, factors influencing students' ability to interpret the ERs. Thirdly, to develop a
model of these factors and investigate the practical applications of the model, including
guidelines fOf improving ER design and the teaching and learning with ERs. The study was
conducted at the University of KwaZulu-Natal, South Africa and involved a total of 166
second and third-year biochemistry students. The research aims were addressed using a p,ostpositivistic
approach consisting of inductive and qualitative research methods. Data was
collected from students by means of written probes, audio- and video-taped clinical
interviews, and student-generated diagrams.
Analysis of the data revealed three general categories of student difficulties, with the
interpretation of three textbook ERs depicting antibody structure and interaction with antigen,
termed the process-type (P), the. structural-type (S) and DNA-related (D) difficulties.
Included in the three general categories of difficulty were seventeen sub-categories that were
each classified on the four-level research framework of Grayson et al. (2001) according to
v
how much information we had about the nature ofeach difficulty and, therefore, whether they
required further research. The incidences of the classified difficulties ranged from 3 to 70%,
across the student populations and across all three ERs. Based on the evidence of the
difficulties, potential sources of the classified difficulties were isolated. Consideration of the
nature of the sources of the exposed difficulties indicated that at least three factors play a
major role in students' ability to interpret ERs in biochemistry. The three factors are:
students' ability to reason with an ER and with their own conceptual knowledge (R),
students' understanding (or lack thereof) of the concepts of relevance to the ER (C), and the
mode in which the desired phenomenon is represented by the ER (M).
A novel three-phase single interview technique (3P-SIT) was designed to explicitly
investigate the nature of the above three factors. Application of3P-SIT to a range of abstract
to realistic ERs of antibody structure and interaction with antigen revealed that the. instrument
was extremely useful for generating data corresponding to the three factors.. In addition;
analysis of the 3P-SIT data showed evidence for the influence ofone factor on another during
students' ER interpretation, leading to the identification of a further four interactive factors,
namely the reasoning-mode (R-M), reasoning conceptual (R-C), conceptual-mode (C-M) and
conceptual-reasoning-mode (C-R-M) factors. The Justi and Gilbert (2002) modelling process
was employed to develop a model of the seven identified factors. Empirical data generated
using 3P-SIT allowed the formulation and validation of operational definitions for the seven
factors and the expression of the model as a Venn diagram,
Consideration ofthe implications of the model, yielded at least seven practical applications of
the model, including its use for: establishing whether sound or unsound interpretation,
learning and visualisation of an ER has occurred; identifying the nature and source of any
difficulties; determining which of the factors of the model are positively or negatively
influencing interpretation; establishing what approaches to ER design and teaching and
learning with ERs will optimise the interpretation and learning process; and, generally
framing and guiding researchers', educators' and authors' thinking about the nature of students'
difficulties with the interpretation of both static and animated ERs in any scientific context.
In addition, the study demonstrated how each factor of the expressed model can be used to
inform the design of strategies for remediating or preventing students' difficulties with the
interpretation of scientific ERs, a target for future research. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.
|
479 |
Dendritic cell and IgA responses in SIV and HIV-1 pathogenesis /Söderlund, Johan, January 2004 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.
|
480 |
Seguimento de mulheres grávidas vacinadas inadvertidamente contra rubéola no Brasil em 2001 e 2002 / Follow-up of pregnant women inadvertently vaccinated against rubella in Brazil in 2001 and 2002Soares, Rosa Castalia França Ribeiro January 2009 (has links)
Made available in DSpace on 2011-05-04T12:36:21Z (GMT). No. of bitstreams: 0
Previous issue date: 2009 / Considerando a carga e gravidade da Síndrome da Rubéola Congênita (SRC), uma campanha nacional de vacinação de mulheres com idade entre 12 e 39 anos foi realizada no Brasil em 2001-2002 com a meta de imunizar mais de 30 milhões de mulheres. A possibilidade de vacinar mulheres grávidas motivou a iniciativa de acompanhar gestantes vacinadas inadvertidamente (GVI) contra rubéola. Os objetivos do estudo foram descrever o estado imunológico das mulheres, detectar infecção congênita pelo vírus vacinal (ICR) e estimar o risco de SRC e ICR associado ao vírus vacinal. Realizou-se um estudo prospectivo não controlado no qual as taxas de SRC e ICR vacinais foram comparadas a dados históricos. O estudo foi conduzido em 7 Estados:Rio de Janeiro, São Paulo, Pernambuco, Minas Gerais, Bahia, Rio Grande do Sul e Goiás. Métodos laboratoriais incluíram teste sorológico rubéola-específico para IgM e IgG, PCR para detecção viral e seqüenciamento genômico para diferenciação viral. Uma GVI suscetível foi definida como aquela testada para rubéola até 30 dias após a vacinação e apresentou IgM positivo e IgG negativo. SRC associada à vacinação foi definida pela presença dos critérios da Organização Mundial da Saúde para a SRC em recém-nascidos de GVI suscetível, apresentando IgG+ e com vírus vacinal identificado. De um total de 16.435.776 mulheres vacinadas, 20.395 estavam grávidas no momento da vacinação. Destas, 2.330 (11,4 por cento) foram consideradas suscetíveis à rubéola. No acompanhamento de 1.797 recém-nascidos foram identificados 63 (3,5 por cento) IgM positivos configurando ICR. Os resultados das 2230 gestações em 5 Estados incluíram 80 (3,4 por cento) abortos e 11 (0,5 por cento) natimortos. Dados clínicos de 47 dos 63 casos de IRC mostraram 5 recém-nascidos com baixo peso, 4 prematuros, 1 comunicação inter-atrial e 1 sopro cardíaco aos 35 dias de vida, os quais não são compatíveis com SRC. A taxa de ICR foi de 3,5 por cento e nenhum caso de SRC foi detectado. Nossos dados reforçam as recomendações de (1) manter a contra-indicação de vacinação na gravidez e (2) não interromper a gravidez em caso de vacinação inadvertida. / Considering the burden and severity of Congenital Rubella Syndrome (CRS), a countrywide vaccination campaign was conducted in Brazil in 2001 and 2002 with the goal of immunizing over 30 million women aged 12 to 39 years. The possibility of
vaccinating women unaware of their pregnancy prompted an initiative to identify and
follow-up pregnant women inadvertently vaccinated (PWIV) against rubella. The objectives of this study were: to describe the immunological status of these women and ascertain vaccine virus infection in neonates born to women susceptible to rubella infection at the time of vaccination, and to estimate the risk of Congenital Rubella
Infection (CRI) and CRS in neonates associated with the vaccine virus. This was a prospective uncontrolled study, in which rates of CRI and CRS due to the vaccine were compared with data from historic control group. The study was conducted in seven states of the country: Rio de Janeiro, São Paulo, Pernambuco, Minas Gerais, Bahia, Rio
Grande do Sul, and Goiás. Laboratory methods included serum enzyme immune assay (EIA) for rubella IgM and IgG detection, PCR for viral detection and genomic sequencing for viral differentiation. A susceptible PWIV was defined as one tested for rubella within 30 days after vaccination and presented positive IgM and negative IgG. CRI associated with vaccination was defined as a newborn to a susceptible PWIV
presenting with positive rubella IgM and having the vaccine virus identified but without CRS syndrome. CRS associated with vaccination was defined as a newborn to a susceptible PWIV who fulfilled the WHO criteria for CRS syndrome, presenting with positive rubella IgM and having the vaccine virus identified. From a total of 16,435,776 women, 20,395 were pregnant at the time of vaccination. Among these, 2,330 (11.4%)
were considered susceptible at vaccination. The follow-up of 1,797 (77.1%) newborns disclosed 63 (3.5%) IgM positive, which was considered vaccine-associated CRI. Outcomes of 2,230 pregnancies in 5 states include 80 abortions (3.4%), and 11
stillborns (0.5%). Clinical data from 47 of the 63 CRI cases (75%) disclosed: 5 low birth weight, 4 preterm, 1 inter-atrium communication, and 1 cardiac murmur at 35 days of life, which are not compatible with CRS definitions. The rate of CRI was 3.5% and no CRS cases were detected. Our data support the recommendation (1) that pregnancy
should remain a contraindication to vaccination and precautions should be taken to avoid vaccination within 28 days of vaccination; and (2) that in case vaccination occurs within 28 days of pregnancy, interruption of pregnancy should not be conducted.
|
Page generated in 0.0714 seconds