RESUMO
The authors report a solitary mastocytoma with a solitary red infiltrated plaque on the dorsum of the right foot for 2 months. Histologically there were numerous mast cells infiltrating the dermis. Electron microscopy revealed CLCs located in phagosomes of activated macrophages as well as in the stromal tissue, close association between CLCs formation and damaged eosinophils was documented Charcot-Leyden crystals (CLCs) have been found in many conditions associated with eosinophilia, but their occurrence in skin diseases is very rare. These occurrences showed the evidence that the formation of CLCs in a mastocytoma correlated to the individual and related to the biology of mast cells, basophils, eosinophils and macrophages. Phagosomes probably acted as the localization of CLCs formation. The pathological role of CLCs in a mastocytoma needs further investigation.
Assuntos
Mastocitoma/ultraestrutura , Humanos , Lactente , Masculino , Microscopia EletrônicaRESUMO
Nitric oxide (NO) has been shown to inhibit both normal and cancer cell proliferation. Potassium channels are involved in cell proliferation and, as NO activates these channels, we investigated the effect of NO on the proliferation of murine mastocytoma cell lines and the putative involvement of potassium channels. NO (in the form of NO donors) caused dose-dependent inhibition of cell proliferation in the P815 cell line inducing growth arrest in the mitosis phase. Incubation with NO donor for 4 or 24 h had a similar inhibitory effect on cell proliferation, indicating that this effect is irreversible. The inhibitory effect of NO was completely prevented by the blockade of voltage- and calcium-dependent potassium channels, but not by blockade of ATP-dependent channels. NO inhibition of cell proliferation was unaffected by guanylate cyclase and by cytoskeleton disruptors. Therefore, NO inhibits cell proliferation irreversibly via a potassium channel-dependent but guanylate cyclase-independent pathway in murine mastocytoma cells.
