RESUMO
The present study was carried out to observe the cytotoxicity of yellow sand in comparison with silica and titanium dioxide in a rat alveolar type II cell line (RLE-6TN). Yellow sand (China Loess) was obtained from the loess layer in the Gunsu Province of China. The mean particle diameter of yellow sand was about 0.003 +/- 0.001 mm. Major elements of yellow sand were Si(27.7 +/- 0.6%), Al(6.01 +/- 0.17%), and Ca(5.83 +/- 0.23%) in that order. Silica and yellow sand significantly decreased cell viability and increased [Ca2+]i. All three particles increased the generation of H2O2. TiO2 did not change Fenton activity, while silica induced a slight increase of Fenton activity. In contrast, yellow sand induced a significant increase of Fenton activity. Silica, yellow sand and TiO2 induced significant nitrite formations in RLE-6TN cells. Silica showed the highest increase in nitrite formation, while yellow sand induced the least formation of nitrite. Silica and yellow sand increased the release of TNF-a. Based on these results, we suggest that yellow sand can induce cytotoxicity in RLE-6TN cells and reactive oxygen species, Fenton activity and reactive nitrogen species might be involved in this toxicity.
Assuntos
Alumínio/química , Animais , Cálcio/análise , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Meios de Cultivo Condicionados/química , Células Epiteliais/efeitos dos fármacos , Peróxido de Hidrogênio/análise , Pulmão/citologia , Macrófagos Alveolares/efeitos dos fármacos , Nitritos/análise , Tamanho da Partícula , Ratos , Silício/química , Dióxido de Silício/química , Titânio/efeitos adversos , Fator de Necrose Tumoral alfa/efeitos dos fármacosRESUMO
The authors present a modified rhinoplasty to tret a postcomposite graft alar rim defect.
Assuntos
Humanos , Feminino , Adulto , Nariz/cirurgia , Rinoplastia , Deformidades Adquiridas Nasais/cirurgia , Nariz/lesõesRESUMO
In 1975, Sheen reported on a technique of nasal tip projection by means of a cartilaginous graft [1[. This technique, allied to some general principles in primary and secondary rhinoplasties presented in his book [2[, revolutionized the nasal surgery. Unfortunately, the execution of Sheen's technique of nasal tip grafting, as originaly described, is not easy nor is the procedure troublefree, and the fantastic esthetic results obtained by the author seem to be irreproducible for a less skilled surgeon. The authors of this article present their experience with Sheen's tip graft in primary rhinoplasty and analyze critically the procedure, stressing the necessity of correct selection of patients.