Temporal relationship of EEG abnormalities in migraine to headache and medication.
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Adolescent↗
Biomedical subjects
J T Slevin
Publications and source records attributed to J T Slevin.
Pupillary dysfunction in myasthenia gravis.
The constriction-dilation cycles of pupils exposed to a stationary, discrete slit-lamp beam were significantly prolonged in 25 myasthenic patients (1,060.4 +/- 45.8 msec) undergoing therapy with steroids, anticholinesterases, or both, compared to normal controls (801.9 +/- 8.6 msec) or subjects receiving steroids for nonneurological disease (860.9 +/- 14.9 msec). The duration of myasthenia correlated with the slowing of the cycle time. Myasthenia gravis may affect ectodermally derived smooth muscle or the autonomic neuromuscular junction or both, and not be restricted to the well-demonstrated alterations of neuromuscular junction in striated muscle of mesodermal origin. Alternatively, prolonged pupillary cycles could be attributed to dysfunction of central pathways of the pupillary light reflex.
Adolescent↗
Triazolines XV. Anticonvulsant profile of ADD 17014, a potentially unique 1,2,3-triazoline antiepileptic drug, in mice and rats.
ADD 17014[1-(4-chlorophenyl)-5-(4-pyridyl) delta 2-1,2,3-triazoline], is a representative member of a hitherto unknown, structurally novel family of anticonvulsant agents. The anticonvulsant profile of ADD 17014 following intraperitoneal (i.p.) and oral administration in mice and rats was evaluated using a battery of well-standardized anticonvulsant tests and compared with phenytoin (PHT), phenobarbital (PB), ethosuximide (ESM), and valproate (VPA). The results indicate that ADD 17014 is effective in nontoxic i.p. doses in mice by the maximal electroshock seizure (MES), Metrazol (subcutaneous, s.c. Met), bicuculline (s.c. Bic) and picrotoxin (s.c. Pic) tests, but ineffective against strychnine-induced seizures; it is also effective after nontoxic oral doses in both mice and rats by the MES and s.c. Met tests. Protective indices (PI = TD50/ED50), calculated from i.p. data in mice, were highest for ADD 17014 by the s.c. Met (26.02) and s.c. Bic (93.93) tests; the PIs, after oral administration in mice and rats, were equal to or higher than those of the prototype agents. In vitro receptor binding studies of ADD 17014 and potential metabolites indicated no significant inhibitory activity except for the beta-amino alcohol, which displaced almost 93% of [3H]glutamate from the glutamate receptors, suggesting that ADD 17014 may be functioning as a prodrug and an excitatory amino acid antagonist. The overall results indicate that ADD 17014 is a relatively nontoxic agent that more closely resembles PB and VPA, with a broad and unique spectrum of anticonvulsant activity.
Animals↗
Failure of folic acid derivatives to mimic the actions of kainic acid in brain in vitro or in vivo.
The ability of three derivatives of folic acid, N-5-methyltetrahydrofolic acid (MTHF), tetrahydrofolic acid (THF) and dihydrofolic acid (DHF) to mimic the actions of kainic acid (KA) in a number of in vitro and in vivo systems known to be sensitive to KA was examined. None of the three folate derivatives at 100 microM concentration significantly inhibited the specific binding of [3H]-KA to striatal membranes although 2 microM L-glutamate produced a 40% inhibition. None of the three folate derivatives stimulated the formation of cyclic GMP in cerebellar slices incubated in vitro although KA (0.5 mM) increased cyclic GMP levels by 2.5-fold. Whereas intrahippocampal injection of 2.3 nmoles of KA produces prolonged abnormalities of the EEG, limbic-type seizures and a characteristic pattern of neuronal degeneration in the hippocampal formation and related structures, intrahippocampal injection of a 100-fold greater dose of THF caused only minor and transient EEG abnormalities, no overt seizures and a highly restricted lesion. Whereas intrastriatal injection of 5.6 nmoles of KA caused a profound reduction in the specific activities of choline acetyltransferase and glutamate decarboxylase, markers for striatal intrinsic cholinergic and GABAergic neurons, 50-fold greater doses of MTHF did not affect either enzyme although this high dose of THF did cause a significant 33% reduction in choline acetyltransferase activity. These findings support the suggestion that THF may have weak neurotoxic effects in brain but indicate that the actions of this compound and the related MTHF and DHF are not mediated through KA-specific receptors.
Animals↗