Aporte de las imágenes en el diagnóstico de los paragangliiomas de cabeza y cuello / Radiologic support for the diagnosis of paragangliomas of the head and neck

Los paragangliomas de cabeza y cuello son tumores que derivan de las células neuroendócrinas de los paraganglios extrasuprarrenales y se extienden desde la base de cráneo hasta el cayado aórtico. El pronóstico es en general favorable, excepto los que se ubican en el hueso temporal. En el presente trabajo se describen las características en imágenes de las diferentes localizaciones y subtipos de este tumor, en conjunto con una revisión de la literatura hasta la actualidad. Los métodos por imágenes son muy útiles para poder arribar al diagnóstico. El diagnóstico diferencial es de vital importancia a la hora de evitar procedimientos invasivos riesgosos y contraindicados en estos pacientes, como la biopsia

Aporte de las imágenes en el diagnóstico de los paragangliiomas de cabeza y cuello / Radiologic support for the diagnosis of paragangliomas of the head and neck

Los paragangliomas de cabeza y cuello son tumores que derivan de las células neuroendócrinas de los paraganglios extrasuprarrenales y se extienden desde la base de cráneo hasta el cayado aórtico. El pronóstico es en general favorable, excepto los que se ubican en el hueso temporal. En el presente trabajo se describen las características en imágenes de las diferentes localizaciones y subtipos de este tumor, en conjunto con una revisión de la literatura hasta la actualidad. Los métodos por imágenes son muy útiles para poder arribar al diagnóstico. El diagnóstico diferencial es de vital importancia a la hora de evitar procedimientos invasivos riesgosos y contraindicados en estos pacientes, como la biopsia

The distribution of presumptive thoracic paraganglionic tissue in the common marmoset (Callithrix jacchus).

The aortic-pulmonary regions (APR) of seven adult marmosets (Callithrix jacchus) and the region of the right subclavian artery of a further three marmosets were diffusion-fixed with 10% buffered formol-saline solution. In both regions serial 5 microm sections were cut and stained by the Martius yellow, brilliant crystal scarlet and soluble blue method. Presumptive thoracic paraganglionic (PTP) tissue was only observed in the APR. PTP tissue was composed of small groups of cells that varied in size and number. The distribution of the groups of cells was extremely variable, so much so that it would be misleading to attempt to classify their position; they were not circumscribed by a connective tissue capsule, but were always related to the thoracic branches of the left vagus nerve. The cells lay in loose areolar tissue characteristic of this part of the mediastinum and received their blood supply from small adjacent connective tissue arterioles. Unlike the paraganglionic tissue found in the carotid body the cells in the thorax did not appear to have a profuse capillary blood supply. There was, however, a close cellular-neural relationship. The cells, 10-15 microm in diameter, were oval or rounded in appearance and possessed a central nucleus and clear cytoplasm. No evidence was found that these cells possessed a 'companion' cell reminiscent of the arrangement of type 1 and type 2 cells in the carotid body. In conclusion, we found evidence of presumed paraganglionic tissue in the APR of the marmoset which, however, did not show the characteristic histological features of the aortic body chemoreceptors that have been described in some non-primate mammals. A survey of the mediastina of other non-human primates is required to establish whether this finding is atypical for these animals.

The distribution of presumptive thoracic paraganglionic tissue in the common marmoset (Callithrix jacchus)

The aortic-pulmonary regions (APR) of seven adult marmosets (Callithrix jacchus) and the region of the right subclavian artery of a further three marmosets were diffusion-fixed with 10 percent buffered formol-saline solution. In both regions serial 5-æm sections were cut and stained by the Martius yellow, brilliant crystal scarlet and soluble blue method. Presumptive thoracic paraganglionic (PTP) tissue was only observed in the APR. PTP tissue was composed of small groups of cells that varied in size and number. The distribution of the groups of cells was extremely variable, so much so that it would be misleading to attempt to classify their position; they were not circumscribed by a connective tissue capsule, but were always related to the thoracic branches of the left vagus nerve. The cells lay in loose areolar tissue characteristic of this part of the mediastinum and received their blood supply from small adjacent connective tissue arterioles. Unlike the paraganglionic tissue found in the carotid body the cells in the thorax did not appear to have a profuse capillary blood supply. There was, however, a close cellular-neural relationship. The cells, 10-15 æm in diameter, were oval or rounded in appearance and possessed a central nucleus and clear cytoplasm. No evidence was found that these cells possessed a 'companion' cell reminiscent of the arrangement of type 1 and type 2 cells in the carotid body. In conclusion, we found evidence of presumed paraganglionic tissue in the APR of the marmoset which, however, did not show the characteristic histological features of the aortic body chemoreceptors that have been described in some non-primate mammals. A survey of the mediastina of other non-human primates is required to establish whether this finding is atypical for these animals

Catecholamines in paraganglia associated with the hepatic branch of the vagus nerve: effects of 6-hydroxydopamine and reserpine.

Paraganglia are clusters of cells containing catecholamines (CA), mainly norepinephrine (NE) and dopamine (DA). The presence of epinephrine (E), on the other hand, has only been determined by indirect methods in retroperitoneal paraganglia of newborn and aged rats. Because their location, paraganglia associated with the hepatic branch of the vagus nerve may be a possible source of CA for the liver. The main purposes of the present study were to determine CA levels and whether E can be found in the omentum minus which includes paraganglia associated with the hepatic branch of the vagus nerve, and then to study the effects of 6-hydroxydopamine and reserpine on their CA content. Twenty-four female Wistar rats were randomly ascribed to three groups receiving two intraperitoneal injections of either 6-hydroxydopamine, reserpine or saline. Twenty-four hours after the last administration the rats were anesthetized and a portion of the omentum minus was obtained. Left adrenal medulla and a liver fragment were also collected as controls. The samples were processed to be analyzed by high performance liquid chromatography and catecholamine histofluorescence. The results confirm previous reports about the presence of considerable amounts of norepinephrine and dopamine in paraganglia. Norepinephrine and dopamine in the omentum like the adrenal medulla were significantly depleted by reserpine but not by 6-hydroxydopamine treatment, suggesting that some other sources in addition to sympathetic terminals are responsible for CA in the omentum. On the contrary, both drugs reduced liver NE, consistent with the localization of this amine mainly to hepatic sympathetic terminals. Histofluorescence of the omentum revealed 2-4 paraganglia per tissue fragment. Paraganglia associated with the hepatic branch of the vagus nerve contain also E. The presence of perihepatic sources of extra-adrenal CA, and more specifically E, could be of physiological significance.

Paragânglios intraganglionares em coraçöes humanos adultos / Intraganglionic paraganglia in adult human hearts

Descrevem-se dois paragânglios intraganglionares observados em coraçöes de homens adultos, aparentemente sadios, que tiveram morte violenta. Os paragânglios assim localizados poderiam relacionar-se ao controle da funçäo ganglionar

Paragânglio atrial humano intramiocárdico. Relato de caso / Intramyocardial atrial paraganglia in men. A case report

É relatado, em coraçäo humano adulto, um paragânglio localizado na intimidade do fascículo muscular do terço superior do septo interatrial. Säo discutidas as possibilidades de tal achado representar uma variaçäo anatômica ou ser uma associaçäo habitual em decorrência de interaçöes funcionais entre miocélulas e células paraganglionares

Tumor del corpúsculo carotídeo (quemadectoma): dos observaciones / Carotid body tumors (chemodectoma): 2 observations

Se presentan 2 casos de pacientes portadores de tumores del cuerpo carotídeo. Se detalla el plan de estudios diagnósticos y los procedimientos quirúrgicos empleados. Se efectúa una revisión del tema y se sacan conclusiones

Tumor del corpúsculo carotídeo (quemadectoma): dos observaciones / Carotid body tumors (chemodectoma): 2 observations

Se presentan 2 casos de pacientes portadores de tumores del cuerpo carotídeo. Se detalla el plan de estudios diagnósticos y los procedimientos quirúrgicos empleados. Se efectúa una revisión del tema y se sacan conclusiones (AU)

Cardiovascular responses to hypoxia in the spontaneously breathing cat: reflexes originating from carotid and aortic bodies.

The heart rate (fH) and systemic arterial pressure (Pa) responses to transient anoxemic and cytotoxic hypoxia were studied in 18 pentobarbitone-anesthetized, spontaneously breathing cats, by applying N2 tests and i.v. injections of NaCN. Hyperventilation was accompanied by short-latency increases in Pa and fH; they persisted after bilateral vagotomy, sparing the aortic nerves. Acute section of carotid or aortic nerves in different sequences reduced both fH and Pa responses, the contribution of both pairs of nerves being similar. The recording of carotid chemosensory discharges showed transient stimulus-dependent increases in their frequency, to which the ensuing fH and Pa rises were correlated. After sectioning the four buffer nerves, hypoxia provoked long-lasting hypotension and bradycardia. Tachycardia was also observed in response to hypoxia in 4 out of 6 chloralose-anesthetized spontaneously breathing cats, the other two presenting bradycardia. The direction of these cyanide-induced changes in fH was not modified by bilateral vagotomy. It is concluded that tachycardia and hypertension in response to hypoxia are not vagally-mediated consequences of hyperventilation.