Small-animal SPECT and SPECT/CT: application in cardiovascular research

Preclinical cardiovascular research using noninvasive radionuclide and hybrid imaging systems has been extensively developed in recent years. Single photon emission computed tomography (SPECT) is based on the molecular tracer principle and is an established tool in noninvasive imaging. SPECT uses gamma cameras and collimators to form projection data that are used to estimate (dynamic) 3-D tracer distributions in vivo. Recent developments in multipinhole collimation and advanced image reconstruction have led to sub-millimetre and sub-half-millimetre resolution SPECT in rats and mice, respectively. In this article we review applications of microSPECT in cardiovascular research in which information about the function and pathology of the myocardium, vessels and neurons is obtained. We give examples on how diagnostic tracers, new therapeutic interventions, pre- and postcardiovascular event prognosis, and functional and pathophysiological heart conditions can be explored by microSPECT, using small-animal models of cardiovascular disease

Prevalência de anemia e níveis séricos de hemoglobina em adolescentes segundo estágio de maturidade sexual Prevalence of anemia and hemoglobin serum levels in adolescents according to sexual maturation stage

Durante a adolescência o crescimento acelerado promove um aumento nas necessidades nutricionais, inclusive de ferro, tornando os adolescentes um grupo de risco nutricional. O presente estudo objetivou avaliar a prevalência de anemia e os níveis séricos de hemoglobina de acordo com o estágio de maturidade sexual em uma amostra representativa composta por 272 adolescentes matriculados em escolas da rede municipal de ensino de Balneário Camboriú-SC. A auto-avaliação da maturidade sexual foi realizada segundo os critérios de Tanner (1962). Os níveis sangüíneos de hemoglobina foram medidos através do sistema HemoCue® e o diagnóstico de deficiência de ferro foi baseado no critério proposto pela Organização Mundial de Saúde (2001). Foram consideradas significativas as diferenças ao nível de p<0,05. Foi encontrada prevalência de anemia de 31,2%, sem diferença significativa entre os sexos. Os níveis de hemoglobina foram significativamente maiores no sexo masculino (p=0,044) e não foi encontrada diferença significativa entre os valores médios de hemoglobina entre as meninas que haviam atingido a menarca e as que não a haviam atingido. Não foi encontrada associação entre a presença de anemia e o estágio de maturidade sexual dos adolescentes (chi2=1,17; p=0,56). Verificou-se aumento dos níveis séricos de hemoglobina de acordo com o desenvolvimento sexual no sexo masculino, enquanto no sexo feminino não foram encontradas diferenças estatísticas nestes valores com os sucessivos estágios puberais. Estes resultados demonstraram uma prevalência moderada de anemia e sugerem não haver relação entre a anemia e o desenvolvimento puberal na população estudada.<br>Accelerated growth spurt during adolescence leads to increased nutritional requirements, including iron, therefore posing a nutritional risk to adolescents. The present study aimed to assess the prevalence of anemia and hemoglobin serum levels according to the sexual maturation stage in a representative sample comprised of 272 adolescents enrolled in public schools in Balneário Camboriú, SC. Self-assessment of sexual maturation was carried out according to criteria defined by Tanner (1962). Hemoglobin serum levels were measured through the HemoCue® system and the diagnosis of iron deficiency was based on the cut off points proposed by the World Health Organization (2001). Differences were considered significant at the level of p<0.05. We found a prevalence of 31.2% of anemia without significant differences between genders. Hemoglobin serum levels were significantly higher in boys (p=0.044) than in girls. We did not find significant differences between mean hemoglobin levels of girls who had reached menarche and the ones who had not. There was no statistical association between the presence of anemia and sexual maturation stages of adolescents (chi2=1.17; p=0.56). An increase in mean hemoglobin serum levels was observed along with sexual maturation in boys, but not in girls. The results of the present study showed a moderate prevalence of anemia, but did not point out any relation between anemia and sexual maturation in the population studied