Despite advances, stroke remains the largest cause of disability and fourth leading cause of death in the United States. The relationship between changes in human vasculature (atherosclerosis and arteriosclerosis) prior to clinical incident, and other risk factors for stroke remains unclear. This dissertation represents work towards the identification of imaging biomarkers for vascular change, focusing on ultrasound to characterize persons at risk, including differences among race/ethnic groups. This research contained three distinct projects. The first goal was to determine if changes within ultrasonographic measures of carotid vasculature could be found across race/ethnic groups after adjustment for risk factors. The second was to determine if those same measures were related to changes in cerebral white matter known to be associated with ongoing cerebrovascular disease; we compared ultrasound to an MRI marker of subclinical vascular disease, white matter hyperintensity volume (WMHV). Finally, we sought to investigate a known and well-studied ultrasound marker for atherosclerosis, carotid intima-medial thickness, with those same MRI markers of subclinical vascular disease (WMHV). All studies were conducted within an on-going multiethnic cohort that has been followed since 1990, The Northern Manhattan Study. The population is comprised of persons who self-identify as Hispanic (52%), Black (24%), or White (21%), with less than 3% identified as “race/other.” We found race/ethnic differences in carotid arterial stiffness and diameter; carotid diameter increases with age among Hispanics, but not among blacks or whites. A significant correlation was also found between diastolic diameter and subclinical vascular disease, and this relationship was also increased among Hispanics; neither black race nor white race was associated with corresponding increases in both MRI white matter hyperintensity and diastolic diameter. Finally, using a surrogate marker for atherosclerosis, carotid intima-medial thickness (cIMT), we document for the first time, positive associations between cIMT and WMHV. There are important developments still to be made in the field of vascular risk. Use of inexpensive and non-invasive ultrasound technology to approximate ongoing cerebrovascular disease could lead to better understanding of the effect of known risk factors, and could help stroke risk assessment and treatment modification.

Made available in DSpace on 2016-04-29T14:16:26Z (GMT). No. of bitstreams: 1 VERA MARIA LION PEREIRA RODRIGUES.pdf: 2862285 bytes, checksum: e320606d0b5be5a74e206b00df32a0b0 (MD5) Previous issue date: 2005-12-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This doctor s thesis has as its objective to know the socialization processes experienced by three youth groups, belongin to popular segments and formed by residents of the periphery of São Paulo: Coquetel Molotov, located in Itaquera, East Zone; Núcleo Cultural Força Ativa, in Cidade Tiradentes, East Zone; and Núcleo Cultural Poder e Revolução, in Jardim São Savério, Southeast Zone. The objective of the investigation is to analyze the main challenges, conflicts, struggles, initiatives and advances faced by these young people; what they learn and live in their families, schools, workplace, homes, and in their participation in youth groups; their interpersonal and group relationships in private and public spaces and the consequences of their personal and collective lives. Methodologically, the research is developed with the utilization of questionnaires that configure the profile of participating youth and describe the path of each one of the three groups, and of focal groups and semi-structured interviews, which try to understand perceptions, concepts and experiences of class, gender and race/ethnic relations throughout their childhood, adolescence and youth. We investigated what it means to be young in the periphery, the conformation of the relationships among the youth and between the youth and the adults, the division of tasks and living space, the building and the living of subjectivities and gender and ethnic-racial relationships. The conceptual references that base the analyses are from contemporary authors belonging to different areas of the social sciences, such as Education, Psychology, Social Services, for the theme of the youth, which currently has appeared with more strength, requires multidisciplinary attention to be better understood. The results confirm the hypothesis that belonging to youth groups, with the sponsorships and the cultural, social and political propitiates a new meaning and the existence of new gender and ethnic-racial relationships, signaled by respect, equity, dialogue and altering, different from what was learned in their childhood and is still lived in the family, in the school and in the school, and in some instances of the society. They also point that the relationships with new meanings represent possibilities for these youth to transform themselves in socializing and multiplying agents, contributing to their own integration as citizens, as well the integration of other youth / A presente tese de doutorado tem por objeto conhecer os processos de socialização experimentados por três grupos juvenis, pertencentes a segmentos populares e formado por moradores da periferia de São Paulo: Coquetel Molotov, localizado em Itaquera, Zona Leste; Núcleo Cultural Força Ativa, em Cidade Tiradentes, Zona Leste; e Núcleo Cultural Poder e Revolução, no Jardim São Savério, Zona Sudeste. O objetivo da investigação é o de analisar os principais desafios, conflitos, lutas, iniciativas e avanços enfrentados por esses jovens; seus aprendizados e vivências na família, na escola, no trabalho, nos locais de moradia e na participação em grupos juvenis; suas relações interpessoais e grupais em espaços privados e públicos e as decorrências em suas trajetórias de vida pessoal e coletiva. Metodologicamente, a pesquisa se desenvolve com a utilização de questionários, que configuram o perfil de jovens participantes e descrevem o trajeto de cada um dos três grupos, e de grupos focais e entrevistas semi-estruturadas, que procuram apreender percepções, conceitos e experiências de relações de classe, gênero e raça-etnia, no decorrer de suas infâncias, adolescências e juventudes. Investigam-se os significados de ser jovem na periferia, a conformação de relações entre os jovens e entre jovens e adultos, a divisão de tarefas e espaços de convivências, as construções e vivências de subjetividades e de relações de gênero e étnico-raciais. Os referenciais conceituais que fundamentam as análises são principalmente de autores contemporâneos pertencentes a diferentes áreas das ciências sociais, tais como Educação, Psicologia, Serviço Social, Sociologia, pois o tema das juventudes, que vem despontado com mais força na atualidade, demanda olhares multidisciplinares para melhor compreensão. Os resultados confirmam a hipótese de que o pertencimento a grupos juvenis, com protagonismos e participações culturais, sociais e políticas, propicia a ressignificação e a existência de novas relações de gênero e de raça-etnia, sinaladas por respeito, eqüidade, diálogo e alteridade, na contramão do que foi aprendido na infância e ainda é vivido na família, na escola e em algumas instâncias da sociedade. Apontam igualmente que as relações ressignificadas representam possibilidades de que esses jovens se transformem em agentes socializadores e multiplicadores, contribuindo para sua integração cidadã, assim como a de outros jovens