RESUMO
Mammalian cell shape is critically important to cell differentiation, apoptosis, cell division, and growth arrest. In the present study we examined the relationship among cell density, cell phenotype (which include shape and coupling) and cell survival using the human A549, H596 and H520 non-small cell lung carcinoma lines. Thus, cells from monolayers, aggregated and suspended cultures at different densities were exposed to UV-radiation and both the density and the phenotype of the cells induce shifts in cellular growth rate. Except in suspended cultures, we observed a UV-sensitivity closely related to the proliferative status of the cells. The variability of the cellular response to UV were investigated taking into account the shape and the coupling potential of the cell lines, suggesting that an intercellular-contact mechanism provides further protection against UV-radiation damage.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/patologia , Contagem de Células/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Neoplasias Pulmonares/patologia , Raios Ultravioleta , Ciclo Celular/efeitos da radiação , Humanos , Fenótipo , Tolerância a Radiação , Células Tumorais CultivadasRESUMO
Foi estudado o efeito agudo dos raios X, na dose de 154,8mC/kg (660R), exposiçao de corpo inteiro, em núcleos de células do túbulo contorcido proximal de rins de camundongos C57BL, utilizando uma análise morfométrica. A partir dos resultados das contagens de núcleos claros (com predomínio de eucromatina) e escuros (com predomínio de heterocromatina) pôde-se constatar um aumento de hiperecromatismo no período de tempo de 72 horas após a açao dos raios X, o que permitiu estabelcer um novo parâmetro para avaliar os efeitos da radiaçao em rim: o índice de hipercromatismo nuclear.
Assuntos
Animais , Masculino , Camundongos , Contagem de Células/efeitos da radiação , Lesões Experimentais por Radiação/patologia , Túbulos Renais/efeitos da radiação , Fatores de Tempo , Irradiação Corporal TotalRESUMO
The expulsion of antibody-damaged Nippostrongylus brasiliensis nematodes from the intestine of rats irradiated with 750 rad 60Co was induced by thoracic duct lymph (TDL) or mesenteric lymph node (MLN) cells apparently without the help of bone marrow-derived cells. The effector cells were present in the TDL or MLN of rats by the 8th day after infection and could be recovered from the peritoneal cavity. The ability of TDL cells to transfer immunity to irradiated recipients was undiminished when the cells with immunoglobulin on their surface were removed. These results suggest that, following antibody damage, this nematode is expelled by nonimmunoglobulin-bearing lymphocytes which are effective in the absence of newly formed cells derived from the cell recipients.