Feocromocitoma Associado à Neurofibromatose de Von Recklinghausen Tipo 1: um Caso Clínico Raro

Os feocromocitomas são neoplasias originárias das células cromafins da crista neural localizados, na sua grande maioria, na medula supra-renal, podendo também aparecer nos gânglios simpáticos (paragangliomas). Ocorrem de forma esporádica em 90% dos casos; contudo, em cerca de 10% são um componente de síndromes neoplásicas de transmissão autossómica dominante, como a doença de von Hippel-Lindau, a neoplasia endócrina múltipla tipo 2 (MEN 2) e, mais raramente, associados à Neurofibromatose de von Recklinghausen tipo I (3-5%). A este propósito, os autores apresentam o caso de um homem de 54 anos, com uma história pessoal e familiar de Neurofibromatose de von Recklinghausen tipo I em que foi detectado um tumor da supra-renal direita, assintomátic(“incidentaloma”), cuja investigação posterior comprovou ser um feocromocitoma produtor de elevados níveis de epinefrina e nor-epinefrina. Apesar do padrão secretório de catecolaminas apresentado, foi confirmada, por pressurometria de 24 horas, a existência de normotensão e ausência de história familiar de hipertensão arterial, factos igualmente pouco comuns. Discutem-se alguns dos mecanismos patogénicos envolvidos nestas entidades sindromáticas tumorais, bem como o seu comportamento clínico; salienta-se, igualmente, a importância do rastreio oncológico sistemático, nomeadamente de feocromocitomas, em familiares de indivíduos portadores deste tipo de neoplasia autossómica dominante, mesmo que assintomáticos.

Flora capensis :being a systematic description of the plants of the Cape colony, Caffraria, & Port Natal (and neighbouring territories)v. 1-7.

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Flora capensis :being a systematic description of the plants of the Cape colony, Caffraria, & Port Natal (and neighbouring territories)v. 1-7.

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Flora capensis :being a systematic description of the plants of the Cape colony, Caffraria, & Port Natal (and neighbouring territories)v. 1-7.

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Flora capensis :being a systematic description of the plants of the Cape colony, Caffraria, & Port Natal (and neighbouring territories)v. 1-7.

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Flora capensis :being a systematic description of the plants of the Cape colony, Caffraria, & Port Natal (and neighbouring territories)v. 1-7.

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Flora capensis :being a systematic description of the plants of the Cape colony, Caffraria, & Port Natal (and neighbouring territories)v. 1-7.

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Flora capensis :being a systematic description of the plants of the Cape colony, Caffraria, & Port Natal (and neighbouring territories)v. 1-7.

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Flora capensis :being a systematic description of the plants of the Cape colony, Caffraria, & Port Natal (and neighbouring territories)v. 1-7.

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Einfluss von CD152-Signalen auf das Migrationsverhalten von T H 1-Lymphozyten

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2011

Effect of rufinamide on gating properties of voltage-gated sodium channel Na(v)1.7

Background: Voltage-gated sodium channels (Nav1.x) are important players in chronic pain. A particular interest has grown in Nav1.7, expressed in nociceptors, since mutations in its gene are associated to two inherited pain syndromes or insensitivity to pain. Rufinamide, a drug used to treat refractory epilepsy such as the Lennox-Gastaut syndrome, has been shown to reduce the number of action potentials in cortical neurons without completely blocking Na channels. Aim: The goal of this study was to investigate the effect of rufinamide on Nav1.7 current. Methods and results: Whole-cell patch clamp experiments were performed using HEK293 cells stably expressing Nav1.7. Rufinamide significantly decreased peak sodium current by 28.3, 21.2 and 12.5% at concentrations of 500, 100 and 50μM respectively (precise EC50 could not be calculated since higher rufinamide concentrations could not be achieved in physiological buffer solution). No significant difference on the V1/2 of voltage-dependence of activation was seen; however a shift in the steady-state inactivation curve was observed (-82.6 mV to -88.8 mV and -81.8 to -87.6 mV for 50 and 100 μM rufinamide respectively, p <0.005). Frequency-dependent inhibition of Nav1.7 was also influenced by the drug. One hundred μM rufinamide reduced the peak sodium current (in % of the peak current taken at the first sweep of a train of 50) from 90.8 to 80.8% (5Hz), 88.7 to 71.8% (10 Hz), 69.1 to 49.2% (25 Hz) and 22.3 to 9.8% (50 Hz) (all p <0.05). Onset of fast inactivation was not influenced by the drug since no difference in the time constant of current decay was observed. Conclusion: In the concentration range of plasma level in human treated for epilepsy, 15 μM, rufinamide only minimally blocks Nav1.7. However, it stabilizes the inactivated state and exerts frequencydependent inhibition of Nav1.7. These pharmacological properties may be of use in reducing ectopic discharges as a causal and symptom related contributor of neuropathic pain syndrome.

[Helsinki n. 1.7.1934]

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