In vivo effects of reversible inhibitors of cholinesterase activity were determined radiometrically in undiluted samples of erythrocytes and plasma. [14C]acetylcholine at substrate saturation, 25 degrees C and pH 7.4 permitted rapid and precise determination of butyrylcholinesterase (EC 3.1.1.8) and acetylcholinesterase (EC 3.1.1.7) activities. Reference values for acetylcholinesterase and buty...

Prolonged neuromuscular block occurs when suxamethonium is given after neostigmine or pyridostigmine; however, studies of edrophonium and suxamethonium have yielded conflicting results. We have studied, therefore, interactions between suxamethonium and all three anticholinesterases in rats anaesthetized with pentobarbitone. After recovery from an initial bolus of suxamethonium, saline, edrophon...

AIM The optimal treatment of ocular myasthenia gravis (OMG) remains unknown. The authors evaluated the efficacy of prednisone and pyridostigmine in reducing diplopia, ocular motor dysfunction, and ptosis in patients with OMG. METHODS Review of records from a clinical database from one neuro-ophthalmology service of patients presenting with OMG between 1990 and 2002, excluding those who develo...

Acetylcholinesterase pre-mRNA is susceptible to alternative splicing. Myasthenia gravis has been shown to be associated with the expression of the readthrough transcript (AChE-R), which, unlike the normal "synaptic" transcript (AChE-S) is not tethered to the post-synaptic membrane, but is a soluble monomer in the synaptic cleft. In rats with experimental autoimmune myasthenia gravis (EAMG), inh...

The relationship between plasma levels of pyridostigmine to clinical evaluation of muscle power was examined in nine patients with myasthenia gravis during treatment with pyridostigmine in doses of 60 to 1040 mg daily. Five of the nine subjects demonstrated a trend towards a positive correlation, but in only two of them was this statistically significant at p < 0.05. In addition, the presence o...

INTRODUCTION Normal platelet functions are critical for achieving primary haemostasis. Numerous medications have been shown to affect platelet functions. Pyridostigmine (Mestinon), an orally active cholinesterase inhibitor that is commonly used to treat myasthenia gravis has been documented to cause epistaxis and prolonged bleeding after a cut in anectodal reports. This study was initiated afte...