RESUMO
A 71-year-old Caucasian female presented to our service with disseminated cranial and spinal haemangioblastomata but no other features to suggest the von Hippel-Lindau syndrome. We feel that this represents cellular dissemination through the cerebro-spinal fluid and may be an intermediate step to the development of frank haemangioblastomatosis. By comparing this presentation to that of other tumours we have suggested a potential pathological mechanism and have discussed its management.
Assuntos
Neoplasias Encefálicas/patologia , Hemangioblastoma/patologia , Segunda Neoplasia Primária/patologia , Doença de von Hippel-Lindau/diagnóstico , Idoso , Neoplasias Encefálicas/líquido cefalorraquidiano , Neoplasias Encefálicas/cirurgia , Feminino , Hemangioblastoma/líquido cefalorraquidiano , Hemangioblastoma/cirurgia , Humanos , Imageamento por Ressonância Magnética , Invasividade Neoplásica , Segunda Neoplasia Primária/cirurgia , Procedimentos NeurocirúrgicosRESUMO
The regulation of neural precursor cell (NPC) activity is the major determinant of the rate of neuronal production in neurogenic regions of the adult brain. Here, we show that Oncostatin M (Osm) and its receptor, OsmRß, are both expressed in the subventricular zone (SVZ) and that in contradistinction to leukemia inhibitory factor and ciliary neutrophic factor, Osm directly inhibits the proliferation of adult NPCs as measured by a decreased level of neurosphere formation in vitro. Similarly, intraventricular infusion of Osm dramatically decreases the pool of NPCs in both the SVZ and the hippocampus. In keeping with the inhibitory action of Osm, we reveal that mice lacking OsmRß have substantially more NPCs in the SVZ, the hippocampus and the olfactory bulb, demonstrating that endogenous Osm signaling is important for NPC homeostasis. Finally, we show that Osm can also inhibit clonal growth of glioblastoma-derived neurospheres, further supporting the close link between NPCs and tumor stem cells.
Assuntos
Células-Tronco Adultas/metabolismo , Encéfalo/metabolismo , Diferenciação Celular/fisiologia , Células-Tronco Neurais/metabolismo , Oncostatina M/metabolismo , Células-Tronco Adultas/citologia , Células-Tronco Adultas/efeitos dos fármacos , Animais , Encéfalo/citologia , Encéfalo/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Separação Celular , Citometria de Fluxo , Glioblastoma/metabolismo , Humanos , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células-Tronco Neurais/citologia , Células-Tronco Neurais/efeitos dos fármacos , Oncostatina M/farmacologia , Subunidade beta de Receptor de Oncostatina M/metabolismo , Reação em Cadeia da Polimerase , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologiaRESUMO
We present results of experiments on Rayleigh-Bénard convection in liquid 4He at several temperatures. We show visually that with carefully defined boundary conditions the basic convection state consists of parallel rolls which are aligned in one of two directions, the angle thus defined as being temperature dependent and we attempt to explain this behavior. We also show directly the skew-varicose instability acting on the basic state and correlate it with fluctuations in the temperature difference across the fluid layer.