RESUMO
We present methods for the quantitative analysis of brain growth based on the registration of longitudinal MR image data with the use of Jacobian determinant maps to characterise neuroanatomical changes. The individual anatomies, growth maps and tissue classes are also spatially normalised in an 'average space' and aggregated to provide atlases for the population at each timepoint. The average space representation is obtained using the average intersubject transformation within each timepoint. In an exemplar study, this approach is used to assess brain development in 25 infants between 1 and 2 years, and we show consistency in growth estimates between registration and segmentation approaches.
Assuntos
Envelhecimento/patologia , Envelhecimento/fisiologia , Encéfalo/anatomia & histologia , Encéfalo/crescimento & desenvolvimento , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Técnica de Subtração , Pré-Escolar , Simulação por Computador , Feminino , Humanos , Aumento da Imagem/métodos , Lactente , Recém-Nascido , Masculino , Modelos Anatômicos , Modelos Neurológicos , Tamanho do Órgão/fisiologia , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
To assess natural immunity against the circumsporozoite (CS) protein and the synthetic vaccine SPf66, immunologic studies were carried out in a highly endemic malarious area of Papua New Guinea. Antibody prevalence, antibody titers, and T cell proliferation against both antigens were measured in 214 adults. Immunologic data were analyzed with respect to longitudinal malariologic and morbidity data. Evidence of genetic traits such as glucose-6-phosphate dehydrogenase deficiency and ovalocytosis was analyzed. Antibody prevalence was high, with 79% and 84% for CS protein and SPf66, respectively, while T cell proliferation was infrequent and low, with 14% and 12% responders, respectively. Anti-CS protein antibodies increased with age but showed no association to malaria indices or morbidity. No protective value was observed with T cell responses or with humoral response to SPf66. These results provide a first description of naturally developed immunity against SPf66 and suggest further studies in to fully understand the mechanism of immunity against this antigen.