Neonatal monosodium glutamate administration increases aminooxyacetic acid (AOA) susceptibility effects in adult mice.

Neonatal administration of monosodium glutamate (MSG) to mice causes neurotoxicity of the CNS resulting in endocrine, metabolic and behavioral abnormalities. Aminooxyacetic acid (AOAA) is a potent inhibitor of GABA-transaminase and increases GABA levels in the brain. In this work, we studied the effect of neonatal treatment of CFW mice with MSG (2 mg/g sc on the 2nd and 4th days after birth followed by 4 mg/g on days 6, 8 and 10) on AOAA- (100 to 250 mg/kg ip) induced hypothermia, hypnosis and lethality after six months of treatment. The control group was vehicle-treated only. MSG treatment significantly increased susceptibility to the hypothermic, hypnotic and lethal effect of AOAA acutely administered. The increased susceptibility to the depressor effects of AOAA may occur as a consequence of changes in neural excitability, up regulation of GABA-receptors or might be related to pharmacokinetic modifications induced by neonatal treatment with MSG.

Acute toxicity of guaiacol administered subcutaneously in the mouse.

Guaiacol is a compound used as expectorant. In Mexico City, this product is being illegally used for aesthetic treatment with fatal results. The aim of this study is to confirm the lethal toxicity documented in humans. Male Swiss Webster mice (CFW) 30-45g were employed. Dose-response curves to guaiacol were performed by subcutaneous administration (6.25-400 microl/40g). Basal temperature was recorded 30-120 min following administration of guaiacol. Animals were continuously observed for 120 min after guaiacol administration, lethality and toxicity manifestations were recorded. Depending of the dose, high toxicity was observed; sub lethal doses (6.25-12.5 microl/40 g) produced tachycardia and hyperactivity, follow by sedation, hypnosis, high hypothermic effect (loss of 6 degrees C) dyspnea, myoclonus, hematuria, blindness, abdominal distension and in higher doses (25-400 microl/40 g) lethal effect. Necropsy showed hepatic and renal necrosis, pulmonary edema, hemorrhages and bladder clotting. We concluded that guaiacol is an extremely toxic product (toxic rating class 5) whose use should be restricted or banned.

Knowledge about local anesthetics in odontology students.

The purpose of the study was to identify the level of knowledge of local anesthetics frequently used in the surgical clinic by third and fourth year dental students in daily practice. The importance of pharmacology in dental practice in underscored by potential drug toxicity. The study was performed with 244 third and fourth grade career dental students (CDS). Eleven items regarding the knowledge over local anesthetics at the clinic; i.e., the appropriate doses, possible toxic effects and side effects were examined. The reference questionnaire which is in a validation process, is a way to evaluate student knowledge about most drugs used in odontology practice such as: NSAIDs, antibiotics and local anesthetics. The results were found to be unsatisfactory with a high percentage of students failing (less than six of eleven items correct). We conclude that determination of practice knowledge is an essential step in informing the institution about cognitive deficiencies identified in order to plan learning solutions.