The Experts below are selected from a list of 150 Experts worldwide ranked by ideXlab platform
Jean-françois Pellissier - One of the best experts on this subject based on the ideXlab platform.
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Pituicytomas, a mis-diagnosed benign tumor of the Neurohypophysis: report of three cases.
Acta Neuropathologica, 2002Co-Authors: Dominique Figarella-branger, Carla Fernandez, C. Bouvier-labit, Henry Dufour, François Grisoli, Jean-françois PellissierAbstract:Pituicytoma is a rare benign primary tumor of the Neurohypophysis, occurring in the sellar and suprasellar spaces. We report here three new cases with immunohistochemical and electron microscopic study. Particular attention was paid to the expression of some cell adhesion molecules. These tumors were characterized by bundles of elongated cells strongly immunoreactive to anti-vimentin, S-100 protein, neural cell adhesion molecule and neuron-specific enolase antibodies. Glial fibrillary acidic protein (GFAP) was not recorded. It expressed the very late antigen α2 (VLAα2), but not VLAα5, and lacked epithelial markers expression (epithelial membrane antigen, E-cadherin), and specific neuronal markers (synaptophysin, chromogranin, neurofilament). Staining for pituitary hormones was negative. At the ultrastructural level, tumor/blood vessel basal lamina and cytoplasmic intermediate filaments were observed but desmosome or pericellular basal lamina were lacking. In one case few secretory granules were recorded. Differential diagnoses include granular cell tumors, pilocytic astrocytomas and spindle cell tumors such as solitary fibrous tumors, fibroblastic meningiomas and schwannomas. However, the unique pattern of antigenic expression and ultrastructural features of pituicytomas distinguish this rare tumor. As a subpopulation of pituicytes (which are distinctive glial cells of the neurophypophysis), some pituicytomas do not expressed GFAP. This suggests that pituicytomas presumably arise from pituicytes at various stages of their differentiation.
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Pituicytomas, a mis-diagnosed benign tumor of the Neurohypophysis: report of three cases.
Acta Neuropathologica, 2002Co-Authors: Dominique Figarella-branger, Carla Fernandez, C. Bouvier-labit, Henry Dufour, François Grisoli, Jean-françois PellissierAbstract:Pituicytoma is a rare benign primary tumor of the Neurohypophysis, occurring in the sellar and suprasellar spaces. We report here three new cases with immunohistochemical and electron microscopic study. Particular attention was paid to the expression of some cell adhesion molecules. These tumors were characterized by bundles of elongated cells strongly immunoreactive to anti-vimentin, S-100 protein, neural cell adhesion molecule and neuron-specific enolase antibodies. Glial fibrillary acidic protein (GFAP) was not recorded. It expressed the very late antigen α2 (VLAα2), but not VLAα5, and lacked epithelial markers expression (epithelial membrane antigen, E-cadherin), and specific neuronal markers (synaptophysin, chromogranin, neurofilament). Staining for pituitary hormones was negative. At the ultrastructural level, tumor/blood vessel basal lamina and cytoplasmic intermediate filaments were observed but desmosome or pericellular basal lamina were lacking. In one case few secretory granules were recorded. Differential diagnoses include granular cell tumors, pilocytic astrocytomas and spindle cell tumors such as solitary fibrous tumors, fibroblastic meningiomas and schwannomas. However, the unique pattern of antigenic expression and ultrastructural features of pituicytomas distinguish this rare tumor. As a subpopulation of pituicytes (which are distinctive glial cells of the neurophypophysis), some pituicytomas do not expressed GFAP. This suggests that pituicytomas presumably arise from pituicytes at various stages of their differentiation.
Dominique Figarella-branger - One of the best experts on this subject based on the ideXlab platform.
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Pituicytomas, a mis-diagnosed benign tumor of the Neurohypophysis: report of three cases.
Acta Neuropathologica, 2002Co-Authors: Dominique Figarella-branger, Carla Fernandez, C. Bouvier-labit, Henry Dufour, François Grisoli, Jean-françois PellissierAbstract:Pituicytoma is a rare benign primary tumor of the Neurohypophysis, occurring in the sellar and suprasellar spaces. We report here three new cases with immunohistochemical and electron microscopic study. Particular attention was paid to the expression of some cell adhesion molecules. These tumors were characterized by bundles of elongated cells strongly immunoreactive to anti-vimentin, S-100 protein, neural cell adhesion molecule and neuron-specific enolase antibodies. Glial fibrillary acidic protein (GFAP) was not recorded. It expressed the very late antigen α2 (VLAα2), but not VLAα5, and lacked epithelial markers expression (epithelial membrane antigen, E-cadherin), and specific neuronal markers (synaptophysin, chromogranin, neurofilament). Staining for pituitary hormones was negative. At the ultrastructural level, tumor/blood vessel basal lamina and cytoplasmic intermediate filaments were observed but desmosome or pericellular basal lamina were lacking. In one case few secretory granules were recorded. Differential diagnoses include granular cell tumors, pilocytic astrocytomas and spindle cell tumors such as solitary fibrous tumors, fibroblastic meningiomas and schwannomas. However, the unique pattern of antigenic expression and ultrastructural features of pituicytomas distinguish this rare tumor. As a subpopulation of pituicytes (which are distinctive glial cells of the neurophypophysis), some pituicytomas do not expressed GFAP. This suggests that pituicytomas presumably arise from pituicytes at various stages of their differentiation.
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Pituicytomas, a mis-diagnosed benign tumor of the Neurohypophysis: report of three cases.
Acta Neuropathologica, 2002Co-Authors: Dominique Figarella-branger, Carla Fernandez, C. Bouvier-labit, Henry Dufour, François Grisoli, Jean-françois PellissierAbstract:Pituicytoma is a rare benign primary tumor of the Neurohypophysis, occurring in the sellar and suprasellar spaces. We report here three new cases with immunohistochemical and electron microscopic study. Particular attention was paid to the expression of some cell adhesion molecules. These tumors were characterized by bundles of elongated cells strongly immunoreactive to anti-vimentin, S-100 protein, neural cell adhesion molecule and neuron-specific enolase antibodies. Glial fibrillary acidic protein (GFAP) was not recorded. It expressed the very late antigen α2 (VLAα2), but not VLAα5, and lacked epithelial markers expression (epithelial membrane antigen, E-cadherin), and specific neuronal markers (synaptophysin, chromogranin, neurofilament). Staining for pituitary hormones was negative. At the ultrastructural level, tumor/blood vessel basal lamina and cytoplasmic intermediate filaments were observed but desmosome or pericellular basal lamina were lacking. In one case few secretory granules were recorded. Differential diagnoses include granular cell tumors, pilocytic astrocytomas and spindle cell tumors such as solitary fibrous tumors, fibroblastic meningiomas and schwannomas. However, the unique pattern of antigenic expression and ultrastructural features of pituicytomas distinguish this rare tumor. As a subpopulation of pituicytes (which are distinctive glial cells of the neurophypophysis), some pituicytomas do not expressed GFAP. This suggests that pituicytomas presumably arise from pituicytes at various stages of their differentiation.
Luiz F. Bleggi Torres - One of the best experts on this subject based on the ideXlab platform.
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Granular cell tumor of the Neurohypophysis: report of a case with unusual age presentation
Virchows Archiv, 2005Co-Authors: Paulo R. Benites Filho, Daniele Sakamoto, Tiago Noguchi Machuca, Maria José Serapião, Leo Ditzel, Luiz F. Bleggi TorresAbstract:Granular cell tumor (GCT) usually occurs as a solitary, small, nodular tumor and rarely grows to a sufficient size to present symptoms. The tumor is more prevalent in female adults. The authors report a case of an 8-year-old boy with GCT of the Neurohypophysis presenting with central precocious puberty. Few cases of symptomatic GCT have been reported in the literature, none of them in a patient in the first decade of life. Clinical picture, histopathological features, and histogenesis of GCT of Neurohypophysis are discussed.
Jean J. Nordmann - One of the best experts on this subject based on the ideXlab platform.
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STIMULUS-SECRETION COUPLING IN THE Neurohypophysis OF THE JERBOA JACULUS ORIENTALIS
The Journal of experimental biology, 1994Co-Authors: Aicha Raji, Jean J. NordmannAbstract:1. In many mammals, severe dehydration is known to cause exhaustion of the vasopressin content of the neural lobe. Here, we have examined the physiological state of the Neurohypophysis of the jerboa Jaculus orientalis, a rodent inhabitant of a semi-desert climate. 2. Isolated neurohypophyses and neurosecretory nerve endings were perfused in vitro and vasopressin and oxytocin release were determined by radioimmunoassay. 3. Electrical stimulation of the Neurohypophysis with bursts of pulses mimicking the activity of hypersecreting neuroendocrine neurones induced similar increases of secretion in both control animals and animals dehydrated for up to 2 months. Neurohormone release was greatly potentiated when the bursts of pulses were separated by silent intervals. 4. Prolonged stimulation of neurohypophyses from both control and dehydrated animals induced a sustained increase of vasopressin release; in contrast, oxytocin release under similar conditions showed a biphasic secretory pattern consisting of a transient increase that subsequently decreased to a steady level whose amplitude was similar to that for vasopressin. 5. K(+)-induced secretion was largely inhibited by the Ca2+ channel blockers nicardipine and omega-conotoxin, suggesting that in this neurosecretory system both L- and N-type calcium channels play a major role in stimulus-secretion coupling. Depolarization of isolated nerve endings using a fast-flow perifusion system showed that there was no difference in the amplitude and the time course of the secretory response in dehydrated and hydrated animals. 6. The results demonstrate that, despite the climatic conditions in which the jerboas live, their neural lobes retain the capacity to release, upon depolarization of the plasma membrane of the nerve endings, large amounts of neurohormone. It is concluded that the neurohypophyseal peptidergic release system in the dehydrated jerboa functions adequately even under extreme environmental stress.
Carla Fernandez - One of the best experts on this subject based on the ideXlab platform.
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Pituicytomas, a mis-diagnosed benign tumor of the Neurohypophysis: report of three cases.
Acta Neuropathologica, 2002Co-Authors: Dominique Figarella-branger, Carla Fernandez, C. Bouvier-labit, Henry Dufour, François Grisoli, Jean-françois PellissierAbstract:Pituicytoma is a rare benign primary tumor of the Neurohypophysis, occurring in the sellar and suprasellar spaces. We report here three new cases with immunohistochemical and electron microscopic study. Particular attention was paid to the expression of some cell adhesion molecules. These tumors were characterized by bundles of elongated cells strongly immunoreactive to anti-vimentin, S-100 protein, neural cell adhesion molecule and neuron-specific enolase antibodies. Glial fibrillary acidic protein (GFAP) was not recorded. It expressed the very late antigen α2 (VLAα2), but not VLAα5, and lacked epithelial markers expression (epithelial membrane antigen, E-cadherin), and specific neuronal markers (synaptophysin, chromogranin, neurofilament). Staining for pituitary hormones was negative. At the ultrastructural level, tumor/blood vessel basal lamina and cytoplasmic intermediate filaments were observed but desmosome or pericellular basal lamina were lacking. In one case few secretory granules were recorded. Differential diagnoses include granular cell tumors, pilocytic astrocytomas and spindle cell tumors such as solitary fibrous tumors, fibroblastic meningiomas and schwannomas. However, the unique pattern of antigenic expression and ultrastructural features of pituicytomas distinguish this rare tumor. As a subpopulation of pituicytes (which are distinctive glial cells of the neurophypophysis), some pituicytomas do not expressed GFAP. This suggests that pituicytomas presumably arise from pituicytes at various stages of their differentiation.
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Pituicytomas, a mis-diagnosed benign tumor of the Neurohypophysis: report of three cases.
Acta Neuropathologica, 2002Co-Authors: Dominique Figarella-branger, Carla Fernandez, C. Bouvier-labit, Henry Dufour, François Grisoli, Jean-françois PellissierAbstract:Pituicytoma is a rare benign primary tumor of the Neurohypophysis, occurring in the sellar and suprasellar spaces. We report here three new cases with immunohistochemical and electron microscopic study. Particular attention was paid to the expression of some cell adhesion molecules. These tumors were characterized by bundles of elongated cells strongly immunoreactive to anti-vimentin, S-100 protein, neural cell adhesion molecule and neuron-specific enolase antibodies. Glial fibrillary acidic protein (GFAP) was not recorded. It expressed the very late antigen α2 (VLAα2), but not VLAα5, and lacked epithelial markers expression (epithelial membrane antigen, E-cadherin), and specific neuronal markers (synaptophysin, chromogranin, neurofilament). Staining for pituitary hormones was negative. At the ultrastructural level, tumor/blood vessel basal lamina and cytoplasmic intermediate filaments were observed but desmosome or pericellular basal lamina were lacking. In one case few secretory granules were recorded. Differential diagnoses include granular cell tumors, pilocytic astrocytomas and spindle cell tumors such as solitary fibrous tumors, fibroblastic meningiomas and schwannomas. However, the unique pattern of antigenic expression and ultrastructural features of pituicytomas distinguish this rare tumor. As a subpopulation of pituicytes (which are distinctive glial cells of the neurophypophysis), some pituicytomas do not expressed GFAP. This suggests that pituicytomas presumably arise from pituicytes at various stages of their differentiation.
