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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neuroblastoma is the most common solid tumour in infancy and childhood. The tumour usually produces large amounts of catecholamines. Few patients with neuroblastoma, however, were reported to have become hypertensive because of catecholamine metabolism within the tumour itself. This is one of the most important differences compared with pheochromocytomas. We experienced a hypertensive crisis accompanied by tachycardia and an increase in the plasma catecholamine concentration during surgery in a patient with neuroblastoma. The plasma catecholamine level was comparable to that of pheochromocytoma. Phentolamine and propranolol were effective to control the hypertension and tachycardia.
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PMID:[A hypertensive crisis during surgery in a patient with neuroblastoma]. 157 28

Treatment of severe arterial hypertension associated with neuroblastoma is not well discussed in the literature. A six-month-old boy was referred for evaluation of an abdominal mass which proved to be neuroblastoma stage IV. Arterial hypertension of 26/16 kPa (190/110 mmHg) was also found. Because of the degree of malignancy and the risk of intra-tumoral haemorrhage, urgent management of the hypertension was required before proceeding to surgery. Phentolamine, a short-acting alpha-blocking agent, was administered as a continuous infusion of a 0.01 per cent solution, at a rate of 1 to 4 microgram X kg-1 X min-1 titrated according to the arterial blood pressure (BP), central venous pressure and urinary output. BP was rapidly controlled and the child went to surgery within 48 hours. The operation was uneventful but only 80 per cent of the tumour could be resected. Phentolamine was discontinued intraoperatively but was reinstituted postoperatively when hypertension recurred. With the return of normal intestinal function five days after surgery, phenoxybenzamine was begun p.o. and phentolamine was tapered over 24 hours and discontinued. A continuous infusion of phentolamine provided satisfactory control pre- and post-operatively with no significant hypotension. We consider this technique to be potentially very useful in the management of severe arterial hypertension associated with neuroblastoma, as it permits early surgical intervention under optimal conditions.
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PMID:[Continuous phentolamine perfusion in the treatment of severe arterial hypertension associated with neuroblastoma]. 670 85

1. The characteristics of the electrical response to dopamine in the mouse neuroblastoma cell line N1E-115 were studied. 2. Neuroblastoma cells responded to ionophoretically applied dopamine by generating a transient depolarization. Under voltage-clamp conditions, a transient inward current was recorded in response to dopamine application. 3. The receptor was more effectively activated by dopamine than by noradrenaline. Haloperidol blocked the dopamine-induced current with an apparent dissociation constant of 40 nM. Phentolamine was much less potent than haloperidol, and propranolol had no effect. 4. The dopamine-induced current was increased in amplitude by hyperpolarizing the membrane, decreased by depolarization, and reversed its polarity at + 14 mV. 5. When the external sodium concentration was decreased from 125 to 94 mM, the reversal potential was shifted in the direction of hyperpolarization by 10 mV. 6. Increasing the external potassium concentration from 0.2 to 20 mM caused a shift of the reversal potential by 13 mV in the direction of depolarization. 7. Replacement of external chloride with isethionate or glutamate caused little or no shift in the reversal potential, but increased the amplitude of the current. 8. Increase in external calcium concentration caused a block of the dopamine-induced current with an apparent dissociation constant of 1.3 mM, without altering its reversal potential. 9. It is concluded that the ionic channel activated by dopamine undergoes a conductance increase to both sodium and potassium but not to chloride or calcium.
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PMID:Characteristics of the electrical response to dopamine in neuroblastoma cells. 718 65