[(11)C]-5-Hydroxytryptophan ([(11)C]HTP) and 6-[(18)F]fluoro-3,4-dihydroxy-l-phenylalanine ([(18)F]FDOPA) are used to image neuroendocrine tumors with positron emission tomography. The precise mechanism by which these tracers accumulate in tumor cells is unknown. We aimed to study tracer uptake via large amino acid transporters, peripheral decarboxylation (inhibited by carbidopa), and intracell...

Levodopa continues to be the most efficacious and widely used treatment for Parkinson's disease. Levodopa dosing is understood to be critical for the optimal control of symptoms, and increasing the levodopa dose is a common method to treat advancing disease. Escalating levodopa dosages coupled with disease progression is associated with increasing likelihood of developing levodopa-induced dyski...

We report the findings in a patient known to have olivopontocerebellar atrophy who developed respiratory distress, inspiratory stridor, and maximum inspiratory and expiratory flow volume loops. Treatment with carbidopa-levodopa gave symptomatic relief.

Continuous dopaminergic delivery is recognized for the capacity to ameliorate symptoms in Parkinson's disease (PD). In advanced PD the short comings of orally administered Levodopa/Carbidopa include fluctuations resulting in unstable effect and dyskinesia. Levodopa/Carbidopa intestinal gel, LCIG, (Duodopa®, Abbott Laboratories) is delivered continuously through a percutaneous endoscopic gastros...

BACKGROUND Gait difficulties, tremors, and coordination difficulties are common features of Cockayne syndrome that are consequences of leukodystrophy, cerebellar atrophy, and demyelinating neuropathy, but no pharmacotherapy for these disabling symptoms is available. OBJECTIVE To determine whether carbidopa-levodopa relieves tremors and other motor complications of Cockayne syndrome. DESIGN ...

INTRODUCTION Many patients who have had Parkinson's disease (PD) for several years will present severe motor fluctuations and dyskinesias which require more aggressive therapies. The different approaches which are now available include deep brain stimulation of the subthalamic nucleus or medial globus pallidus, subcutaneous infusion of apomorphine, and intestinal infusion of levodopa-carbidopa....

1. The effects of inhibition of peripheral aromatic L-amino acid decarboxylase during infusion of the relatively renally selective 5-hydroxytryptamine (5-HT) prodrug, gamma-L-glutamyl-5-hydroxy-L-tryptophan (glu-5-HTP), were examined in eight healthy male subjects in a randomised, placebo-controlled, cross-over study. 2. Each subject received oral carbidopa (100 mg) or placebo followed, 1 h lat...