Protective effect of the APOE-e3 allele in Alzheimer’s disease

Although several alleles of susceptibility to Alzheimer’s disease (AD) have been studied in the last decades, few polymorphisms have been considered as risk factors for the disease. Among them, the APOE-e4 allele appears to be the major genetic risk factor for the onset of the disease. However, it is important to confirm the potential susceptibility of these genetic variants in different populations in order to establish a genetic profile for the disease in specific communities. This study analyzed the APOE polymorphisms regarding susceptibility to AD in a sample of 264 individuals (primarily Caucasians; 82 cases and 182 controls) in the population from Vitória, ES, Brazil, by PCR restriction fragment length polymorphism (PCR-RFLP) methods. The patients were selected according to clinical criteria for probable AD. Whereas the e4 allele showed statistically significant positive association with susceptibility to AD (OR = 3.01, 95 percentCI = 1.96-4.61; P < 0.0001), the e2 allele did not. The results of the e4 allele confirm the role of this polymorphism as a risk factor for AD in the sample studied as observed in other populations. Although the e3 allele has been considered neutral in several studies, our results suggest that it acts as a protective factor against AD in the population studied (OR = 0.46, 95 percentCI = 0.30-0.67; P < 0.0001). This study may provide a new insight into the role of the APOE-e3 allele in the etiology of AD and might help to estabilish a profile of risk for AD in the population from Vitória, ES.

Gluteus maximus and semitendinosus activation during active prone hip extension exercises / Ativação do glúteo máximo e semitendinoso durante exercícios de extensão do quadril em prono

BACKGROUND: Gluteus maximus strengthening exercises are employed in clinical practice as options for the treatment of low back and sacroiliac disorders. However, no studies were found that investigated which were the best exercises to activate this muscle and justify its employment in physical therapy practice. OBJECTIVE: To quantify the electromyographic (EMG) activity of the gluteus maximus and semitendinosus muscles during four modalities of therapeutic exercises. METHODS: Thirty-one participants (16 men, 15 women) were selected. The EMG activities of the gluteus maximus and semitendinosus was recorded and quantified while the participants performed four modalities of therapeutic exercises, involving active prone hip extension in four positions: knee extension (KE), knee flexion (KF), lateral hip rotation and knee extension (LHRKE), and lateral hip rotation and knee flexion (LHR-KF). RESULTS: Repeated-measures ANOVAs showed that the addition of KF or LHR increased gluteus maximus activity, whereas, KE decreased the activation of this muscle. In contrast, the exercises performed with KE increased semitendinosus activity. CONCLUSIONS: Exercises performed with KF or LHR, or a combination of the two, may be effective choices for gluteus maximus strengthening, however both KF and LHR decreased semitendinosus activity. The exercises performed with KE appeared to be an acceptable choice for semitendinosus activation.

CONTEXTUALIZAÇÃO: Exercícios para fortalecimento do glúteo máximo são empregados na prática clínica para tratamento de disfunções da coluna lombar e sacroilíaca. Entretanto, não foram encontrados estudos que investigaram os melhores exercícios para ativar esse músculo de forma a justificar a sua utilização na prática fisioterapêutica. OBJETIVO: Quantificar a atividade eletromiográgica (EMG) dos músculos glúteo máximo e semitendinoso durante quatro modalidades de exercícios terapêuticos. MÉTODOS: Trinta e um participantes (16 homens, 15 mulheres) foram selecionados. A atividade EMG do glúteo máximo e semitendinoso foi registrada e quantificada enquanto os indivíduos realizaram quatro modalidades de exercícios terapêuticos envolvendo extensão ativa do quadril em prono em quatro posições: joelho em extensão, joelho em flexão, rotação lateral do quadril e extensão do joelho e rotação lateral do quadril e flexão do joelho. RESULTADOS: ANOVA medidas repetidas revelou que a adição de flexão do joelho ou rotação lateral do quadril aumentou a atividade do glúteo máximo, enquanto os exercícios realizados com extensão do joelho resultaram na redução da sua ativação. Por outro lado, os exercícios realizados com extensão do joelho aumentaram a atividade do semitendinoso. CONCLUSÕES: Os exercícios realizados com flexão de joelho e/ou rotação lateral do quadril demonstraram ser opções efetivas para ativação do glúteo máximo, mas resultaram em redução da atividade do semitendinoso. Os exercícios realizados com extensão do joelho demonstraram ser uma boa opção para ativar o semitendinoso.