Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038220 (status epilepticus)
 7,272 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have previously reported that cyclothiazide (CTZ) evokes epileptiform activities in hippocampal neurons and induces seizure behavior. Here we further studied in vivo the sensitivity of the hippocampal CA1 neurons in response to CTZ in epileptogenesis in comparison with two other classic convulsants of kainic acid (KA) and pentylenetetrazol (PTZ). CTZ administered intracerebral ventricle (i.c.v.) induced epileptiform activities from an initial of multiple evoked population spikes, progressed to spontaneous spikes and finally to highly synchronized burst activities in hippocampal CA1 neurons. PTZ, when given by subcutaneously, but not by intracerebral ventricle injection, evoked similar progressive epileptiform activities. In contrast, KA given by i.c.v. induced a quick development of epileptiform burst activities and then shortly switched to continuous high frequency firing as acute status epilepticus (ASE). Pharmacologically, alprazolam, a high-potency benzodiazepine ligand, inhibited CTZ and PTZ, but not KA, induced epileptiform burst activities while GYKI 53784, an AMPA receptor antagonist, suppressed CTZ and KA but not PTZ evoked epileptiform activities. In conclusion, CTZ and PTZ induced epileptiform activities are most likely to share a similar progressive pattern in hippocampus with GABAergic mechanism dominant in epileptogenesis, while CTZ model involves additional glutamate receptor activation. KA induced seizure in hippocampus is different to that of both CTA and PTZ. The results from this study indicate that hippocampal neurons respond to various convulsant stimulation differently which may reflect the complicated causes of the seizure in clinics.
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PMID:Epileptiform response of CA1 neurones to convulsant stimulation by cyclothiazide, kainic acid and pentylenetetrazol in anaesthetized rats. 2126 43

Organophosphate chemical threat agents (OP-CTA) exert toxic effects through cholinergic over-activation. However, after the initial cholinergic phase, the pathophysiology shifts to a non-cholinergic phase which leads to prolonged status epilepticus (SE), irreversible neuronal degeneration and long-term damage to the central nervous system. The efficacy of delayed treatments against OP-CTA is generally low due to the fact that most drugs fail to inhibit the later phase of non-cholinergic activation. Recently, we reported that intranasal brain delivery of obidoxime (OBD) provides complete neuroprotection against a lethal dose of paraoxon when administered 5min after intoxication. In follow-up studies, we examined the window of effectiveness and found that OBD lost effectiveness around 15min post-exposure, which corresponds to the onset of the non-cholinergic phase of intoxication. However, we observed that a brief isoflurane administration, the inhalation anesthetic used to facilitate intranasal drug administration, was effective against paraoxon-induced neurotoxicity. Thus, the present study aimed to investigate the time-course and dose-response efficacy of a brief 4min isoflurane administration as a treatment for neurotoxicity induced by OP-CTA. We found that isoflurane is a potent anti-seizure agent and neuroprotectant when administered between 20 and 30min after paraoxon exposure, stopping SE within 10min of administration and preventing acute neurodegeneration seen 24h later. We also found that the seizure blocking and neuroprotectant properties of isoflurane, when administered 30min after paraoxon, are dose-dependent. The effectiveness and current clinical use of isoflurane support its use as an innovative approach for post exposure treatment of organophosphate poisoning.
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PMID:Brief isoflurane administration as a post-exposure treatment for organophosphate poisoning. 2893 37