Navegando por Palavras-chave "Factor Analysis"
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- ItemSomente MetadadadosEnvelhecimento Acelerado Do Sistema Imunológico No Transtorno Bipolar(Universidade Federal de São Paulo (UNIFESP), 2017-02-22) Rizzo, Lucas Bortolotto [UNIFESP]; Brietzke, Elisa Macedo [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Objective: This PhD thesis aimed to structure and test the theory that bipolar disorder (BD) is associated with an accelerated aging of the immune system (immunosenescence). Methods: In order to do that, initially a we performed a literature review of several structural, cellular and molecular changes (among them immunosenescence), which link BD to accelerated aging. Afterwards, a study was performed involving 30 BD patients (15 with less than 5 years of illness, and 15 with more than 10 years of illness) and 29 healthy controls (HC). Different immunosenescence markers were evaluated in this group of subjects, such as the proportion of late differentiated cells (e.g., CD3+CD8+CD28-CD27- and CD3-CD19+IgD-CD27-), telomere length (T/S ratio), cytomegalovirus titer serology (IgM and IgG anti-CMV), T-cell proliferative capacity (CD69 and CD71 expression), production of proinflammatory cytokines, and T regulatory cells functionality (CD4+CD25+FoxP3+CD152+). Confirmatory factorial analysis was used in an expanded sample constituted of 47BD and 47HC in order to identify the "immunological age" trait underlying the immunosenescence markers. Finally, an animal model for BD was studied. Results: The link between biological findings on aging and those on BD were consistent and, thus, generated the theory of accelerated aging in BD (article 1). The evaluation of immunosenescence showed that these markers are more pronounced in the late-stages of the disease and that they correlate with the number of previous episodes (article 2). The "immunological age" trait based on the immunosenescence markers was validated and a higher immunological age was found in BD in relation to the controls (Article 4). A review article relating the pre-frontal medial cortex to the modulation of reward behaviors was developed (article 3). Conclusions: The data presented corroborate the hypothesis of accelerated aging of the immune system in TB.
- ItemSomente MetadadadosExplorando novas abordagens para compreensão da heterogeneidade clínica da esquizofrenia por meio da modelagem de equações estruturais(Universidade Federal de São Paulo (UNIFESP), 2019-04-26) Higuchi, Cinthia Hiroko [UNIFESP]; Araripe Neto, Ary Gadelha De Alencar [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Introduction: Schizophrenia is a heterogeneous disease clinically, therapeutically and biologically. This scenario is considered one of the greatest challenges to achieve real transformation in the field. Current proposals to reduce heterogeneity attempt to delimit dimensions, subtypes, or models of clinical staging. However, these models, for the most part, do not reach psychometric validity (dimensional models), do not have robust biological validation (classical subtypes or staging) or, still, do not reach greater clinical utility than the current constructs. We will use techniques based on the structural equation modeling to evaluate the Positive and Negative Syndromes Scale (PANSS) items. This instrument is widely used and address the possibilities of clinical presentation of schizophrenia. Objective: To explore the potential of PANSS to generate dimensions of symptoms and subgroups of patients with schizophrenia through models with psychometric validity (clinical models) and biological models (neuroimaging biomarkers) generated by structural equation modelling. Specific objectives: Study 1: a) To identify the best 5-factor dimensional model of PANSS; b) To evaluate the impact of clinical staging and other clinical variables in PANSS dimensions. Study 2: a) To use the PANSS as generator of more homogeneous groups regarding the profile of symptoms through a latent class analysis (LCA); b) Validate the final model of classes with external and biological variables (cortical thickness). Methods: Data from 700 patients diagnosed with schizophrenia from four different centers were analyzed. Study 1: CFA models were compared with Bayesian CFA, the latter considered to be more flexible. The multilevel structure was then included. In addition, Multiple Indicators Multiple Causes (MIMIC) modeling evaluated the impact of clinical staging of schizophrenia on the formation of factor mean. Study 2: The best LCA model was chosen based on the comparison of AIC, BIC and Log likelihood values and according to the evaluation of the items probabilities of response applied to the clinical utility of the model. The LCA derived class variable was used in univariate general linear models (GLM) to verify its effect on the cortical thickness of 143 patients, xi controlling the result for sex and age. The frontal and temporal regions of cortical thickness were selected according to the Desikan-Killiany atlas. The p-values were corrected for multiple comparisons (FDR and bonferroni). Results: Study 1: the PANSS CFA factorial solution achieves good fit indices when a multilevel structure is added. The clinical staging of schizophrenia can predict a higher mean of the factors according to the stage of the disease. Study 2: The six-class model best represents patient profiles. The class variable has effect on the cortical thickness of two regions: right superior temporal gyrus (pvalue = 0.012) and right temporal pole (p-value = 0.007), but such p-values did not remain significant after correction by multiple comparisons. Conclusions: The final models have psychometric validity and present: 1) The best dimensional model of PANSS is the CFA with multilevel structure; 2) There is impact of clinical staging in the formation of PANSS mean factors; 3) The sixclass model of PANSS indicated more homogeneous groups that indicate relation to measurements of cortical thickness in temporal regions.
- ItemAcesso aberto (Open Access)Nurses' attitudes towards alcoholism: factor analysis of three commonly used scales(Associação Paulista de Medicina - APM, 1998-03-01) Pillon, Sandra [UNIFESP]; Laranjeira, Ronaldo [UNIFESP]; Dunn, John [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)OBJECTIVE: To investigate the psychometric properties of three scales commonly used to measure attitudes and beliefs about alcoholism. DESIGN: Cross-sectional study using a systematic sample. SETTING: Hospital São Paulo (a public general tertiary hospital) and the adjoining Federal University of São Paulo, Brazil. PARTICIPANTS: 310 nurses and nursing teachers. INSTRUMENTS: The Marcus Alcoholism Questionnaire, The Seaman Mannello Nurses' Attitudes Towards Alcohol and Alcoholism Scale and The Tolor-Tamarin Attitudes Towards Alcoholism Scale, which were combined into one self-administered questionnaire. ANALYSIS: The scales were re-grouped into their original formats and each underwent a principal components analysis with orthogonal rotation of factors. RESULTS: Each scale was found to consist of three main factors. There was some degree of overlap in the nature of the factors that the scales measured but each scale also measured something unique. COCLUSION: The results of this comparative analysis could be used as a basis for developing a new scale covering all the important attitudinal groups identified by this study.