Sunlight exposure in infancy decreases risk of sporadic retinoblastoma, extent of intraocular disease.

BACKGROUND: Prior ecologic studies suggest that UV exposure through sunlight to the retina might contribute to increased retinoblastoma incidence. AIMS: Our study objectives were (1) to examine the relationship between exposure to sunlight during postnatal retinal development (prior to diagnosis of sporadic disease) and the risk of retinoblastoma, and (2) to examine the relationship between sun exposure during postnatal retinal development, and the extent of disease among children with unilateral and bilateral retinoblastoma. METHODS AND RESULTS: We interviewed 511 mothers in the EpiRbMx case-control study about their child's exposure to sunlight during postnatal retinal cell division by examining three time periods prior to Rtb diagnosis coinciding with developmental stages in which outdoor activities vary. Weekly sun exposure was compared by age period, between unilateral (n = 259), bilateral (n = 120), and control (n = 132) children, accounting for two factors affecting UV exposure: residential elevation and reported use of coverings to shield eyes. For cases, association between sunlight exposure and clinical stage was examined by laterality at each age period. After adjusting for maternal education and elevation, sun exposure was lower in cases than controls in all three age periods especially during the first 6 months, and in children 12-23 months whose mothers did not cover their eyes when outdoors. In children diagnosed after 12 months of age, sun exposure during the second year of life (age 12-23 months) appeared inversely correlated (r = -0.25) with more advanced intraocular disease in bilateral Rtb children after adjusting for maternal education, residential elevation, and age of diagnosis (p < .09) consistent with effects of Vitamin D exposure on intraocular spread in earlier transgenic murine models of retinoblastoma, and suggesting potential chemopreventive strategies. CONCLUSION: Sun exposure in early childhood is protective for retinoblastoma and may decrease degree of intraocular spread in children with bilateral Rtb.

Enfermedades renales asociadas a silicosis: revisión de necropsias 1979-1990

El sílice produce lesiones a nivel torácico y también en bazo, médula ósea, ganglios linfáticos extratorácicos, hígado y riñon. El daño renal puede ser directo por la partícula o mediado inmunológicamente. Las lesiones encontradas son glomerulonefritis rápidamente progresiva, necrosante, proliferativa mesangial, proliferativa local y segmentaria, y nefritis intersticial. La nefropatía por IgA ocurre en individuos HLAA29. Se busca establecer asociación de sílice con lesión renal y por ello revisamos 33 protocolos de necropsia con silicosis pulmonar, excluyendo enfermedades concurrentes cuyo órgano blanco fuese riñon, para el presente estudio se tomaron 28 casos en clos cuales realizamos nuevas coloraciones especiales (PAS, Jones y Tricromo) y examen conluz polarizada. En 21se demostró la presencia de sílice en riñon (75 por ciento), 14 había lesión histológica (50 por ciento) y de estos había sílice en 10 (71 por ciento). En 3 casos no había sílice ni lesiones (10 por ciento) y 11 casos con sílice pero sin lesiones. El coeficiente de correlación r (r=0.71) corresponde a una relación moderadamente buena entre la presencia de sílice y cambios histopatológicos. La presente es una revisión de una serie de casos cuyo propósito es plantear la hipótesis de asociación de sílice con lesión renal y concebir la silicosis como enfermedad sistémca.