RESUMO
Measurements of solar UV radiation (UVR) at Bombay, India, lattitude 18.5 North and longitude 72.5 East were recorded using Eppley UV radiometer for a 2-year period. The UV irradiance is calculated and presented. The annual and diurual trends in the quantitation of UVR are examined. The consequences of solar UVR and its projected increase are discussed with special reference to its biological effects and results of UVR on experimental animal systems vis a vis and epidemiological data in the Indian context.
Assuntos
Neoplasias Induzidas por Radiação/etiologia , Neoplasias Cutâneas/etiologia , Luz Solar , Raios Ultravioleta , Animais , Bovinos , Doenças dos Bovinos , Ritmo Circadiano , Humanos , Índia , Neoplasias Induzidas por Radiação/epidemiologia , Neoplasias Induzidas por Radiação/veterinária , Fatores de Risco , Estações do Ano , Neoplasias Cutâneas/epidemiologia , Neoplasias Cutâneas/veterinária , TempoRESUMO
In this study the risk of photochemotherapeutic dose levels of long wave ultraviolet radiation (UVA) was assessed by employing a laboratory animal system, C17 brown mice. The experimental group was subjected to three UVA dose levels, 1000, 2000 and 3500 J/cm2. The dose regimen 50 J/cm2 per day for five days a week was completed in 4, 8 and 14 weeks respectively. The UVA exposed animals were examined until 52 weeks post UVA exposure periods for morphological lesions. Estimations of DNA, protein levels and dermal, epidermal thickness were made. There were no lesions observed with the highest UVA dose employed. Alterations in the DNA and protein levels in the skin of animals in the exposed groups were observed in the post UVA periods. A notable increase in the DNA level was observed 47 weeks post UVA period. The significance of alterations in DNA and protein levels needs to be studied further for evaluation of long term risk following UVA exposure. The data presented however led to a conclusion that the photochemotherapeutic doses of UVA do not pose any risk of cancer to pigmented mouse strains.
Assuntos
Pele/efeitos da radiação , Raios Ultravioleta , Animais , DNA/análise , DNA/efeitos dos fármacos , DNA/efeitos da radiação , Relação Dose-Resposta à Radiação , Feminino , Metoxaleno/farmacologia , Camundongos , Camundongos Endogâmicos , Fotoquimioterapia , Proteínas/análise , Proteínas/efeitos da radiação , Valores de Referência , Pele/citologia , Pele/efeitos dos fármacos , Fatores de TempoRESUMO
Trace element concentrations were determined in surgically resected, cancerous human oesophageal tissue by proton-induced X-ray emission (PIXE) analysis. Each sample was divided into six zones, E3 and E4 formed the central tumour region, E1 and E2 were proximal to the oesophagus and E5 and E6 distal to the oesophagus. Malignancy was confirmed histopathologically in all cases. Samples were dissolved in NaOH solution and pipetted onto a thin mylar film for analysis by a proton beam from a Van de Graaff accelerator. Titanium, Fe, Cu, Zn, As, Rb, Br and Pb were detected in varying concentrations. Of these, Ti, Fe, Cu, Zn and As showed specific behaviour in the six zones.
