Differential effects of aging on spatial contrast sensitivity to linear and polar sine-wave gratings

Changes in visual function beyond high-contrast acuity are known to take place during normal aging. We determined whether sensitivity to linear sine-wave gratings and to an elementary stimulus preferentially processed in extrastriate areas could be distinctively affected by aging. We measured spatial contrast sensitivity twice for concentric polar (Bessel) and vertical linear gratings of 0.6, 2.5, 5, and 20 cycles per degree (cpd) in two age groups (20-30 and 60-70 years). All participants were free of identifiable ocular disease and had normal or corrected-to-normal visual acuity. Participants were more sensitive to Cartesian than to polar gratings in all frequencies tested, and the younger adult group was more sensitive to all stimuli tested. Significant differences between sensitivities of the two groups were found for linear (only 20 cpd; P<0.01) and polar gratings (all frequencies tested; P<0.01). The young adult group was significantly more sensitive to linear than to circular gratings in the 20 cpd frequency. The older adult group was significantly more sensitive to linear than to circular gratings in all spatial frequencies, except in the 20 cpd frequency. The results suggest that sensitivity to the two kinds of stimuli is affected differently by aging. We suggest that neural changes in the aging brain are important determinants of this difference and discuss the results according to current models of human aging

Prevalência de cárie e necessidades de tratamento em escolares de seis a doze anos de idade, Goiânia, GO, Brasil, 1994 The prevalence of dental caries and necessary treatment in six to twelve years old schoolchildren in Brazil, 1994

OBJETIVO: Investigou-se a prevalência de cárie e necessidades de tratamento em escolares de Goiânia-GO, Brasil, que possui água fluoretada há 9 anos. METODOLOGIA: A amostra foi constituída de 1.400 escolares de 6 a 12 anos de idade que freqüentavam escolas públicas na zona urbana do município estudado. RESULTADOS: Os índices CPO-D e ceo-d encontrados no total da amostra foram 2,19 e 2,86, respectivamente, demonstrando uma redução de 57,1% em relação ao CPO-D verificado na região Centro-Oeste, em 1986. Para os escolares de 12 anos de idade, o CPO-D encontrado foi 4,59, estando acima da meta estabelecida para o ano 2.000 pela FDI/OMS. Verificou-se que a percentagem de escolares livres de cárie foi muito baixa em todas as idades, apresentando-se em torno de 11% para o total da amostra. Houve predomínio do tratamento restaurador na dentição decídua em todas as idades e na permanente a partir dos 9 anos de idade. CONCLUSÃO: A prevalência de cárie em escolares de Goiânia-GO é alta e comparável à situação verificada na maioria dos países da América Latina e nas regiões menos favorecidas de países desenvolvidos. Há necessidade de se implantar medidas educativas e preventivas em saúde bucal que intervenham nos reais determinantes da doença na população.<br>OBJECTIVE: The prevalence of dental caries and needs of treatment among schoolchildren in Goiânia-GO, middle-west of Brazil was assessed. METHODOLOGY: The study population consisted of 6-12-yr-old schoolchildren (n=1,400) attending public schools located in the urban area of the city, where the water-supply had been fluoridated for 9 years. RESULTS: Mean dmf-t and DMF-T for the total sample were 2.19 and 2.86, respectively, showing a reduction of 57.1% in the DMF-T as compared to the regional data from the national survey carried out in 1986. At age 12 DMF-T was 4.59, which is above the acceptable level according to the FDI/WHO goal for the year 2000. Percentage of caries-free schoolchildren was very low at all ages (11% of the total sample). The most significant need was for restorative treatment in the treatment deciduous dentition at all ages and in the permanent dentition from age 9. CONCLUSION: It was concluded that the prevalence of dental caries among schoolchildren in Goiânia-GO is high, comparable to the situation in most Latin American countries and poor regions of developed countries. The results indicate the need for oral health education and preventive programs targeted at the underlying causes of the disease, in the population