Focus on cannabinoids and synthetic cannabinoids.

The recent emergence of a multitude of synthetic cannabinoids (SCs) has generated a wealth of new information, suggesting the usefulness of state-of-the-art on lato sensu cannabinoids. By modulating a plurality of neurotransmission pathways, the endocannabinoid system is involved in many physiological processes that are increasingly explored. SCs desired and adverse effects are considered to be more intense than those observed with cannabis smoking, which is partly explained by the full agonist activity and higher affinity for cannabinoid receptors. Neurological and cardiovascular side effects observed after cannabinoid poisoning generally respond to conventional supportive care, but severe outcomes may occur in a minority of cases, mainly observed with SCs. The likelihood of severe abuse and addiction produced by SCs are of concern for the scientific community also interested in the potential therapeutic value of cannabinoids.

Spatial and non-spatial performance in mutant mice devoid of otoliths.

Vestibular deafferentation induces strong spatial memory impairments in rodents and dorsal hippocampal atrophy in humans, suggesting that vestibular information plays an important role in spatial-memory processes. However, previous studies have not discriminated between the role of the semi-circular canals, gravisensors and cochlear sense organ in such impairments due to complete damage of the vestibular and cochlear organs in their models of lesions. This is the first time that mutant mice (het/het) devoid of otoconia (lack of vestibular gravisensors) have been evaluated in behavioral tests. Results show different levels of achievement in the tests. The rotarod and elevated plus-maze were not executable, the rotarod being a safer test for differentiating the het/het mouse phenotype compared to the more anxiogenic swimming pool. Y-maze and place recognition tests were achieved, but chance values were not reached in the het/het group. Additionally, het/het mice presented uncommon behavior when faced with objects during the object recognition test. Impairments in het/het mice in the Y-maze test suggest a crucial role of the vestibular gravisensors in spatial-memory processes.

Influence of anxiety in spatial memory impairments related to the loss of vestibular function in rat.

It is now well established that vestibular information plays an important role in spatial memory processes. Although vestibular lesions induce anxiety in humans, this finding remains controversial in rodents. However, it is possible that anxiety-related behavior is associated with spatial memory impairments after vestibular lesions. We aimed to evaluate anxiety-like behavior and the effect of an anxiolytic treatment during a complex spatial memory task in a rat model of compensated bilateral vestibular lesions. Adult rats were divided into four groups, with or without vestibular lesions and, treated or untreated by diazepam. The vestibular lesion was performed by transtympanic injection of arsanilate and compared to transtympanic saline injection. Diazepam or saline was administered 1h before each test or learning session. Vestibular-lesioned rats exhibited anxiety-like behavior which was decreased with diazepam. Spatial memory performance was similar in control-treated and untreated groups, suggesting no effect on memory at the dose of diazepam used. Spatial memory performances were not modified by anxiolytic drug treatment in vestibular-lesioned rats compared to vestibular-lesioned rats without drug treatment. We conclude that bilateral vestibular lesions in rats induced anxiety-like behavior which was unrelated to spatial memory impairment and was probably specifically related to the loss of vestibular information.

Influence of vestibular input on spatial and nonspatial memory and on hippocampal NMDA receptors.

It has recently been shown that a lack of vestibular sensory information decreases spatial memory performance and induces biochemical changes in the hippocampus in rodents. After vestibular neurectomy, patients display spatial memory deficit and hippocampal atrophy. Our objectives were to explore: (a) spatial (Y maze, radial-arm maze), and non-spatial (object recognition) memory performance, (b) modulation of NMDA receptors within the hippocampus using radioligand binding, and (c) hippocampal atrophy, using MRI, in a rat model of bilateral labyrinthectomy realized in two operations. Chemical vestibular lesions (VLs) were induced in 24 animals by transtympanic injections of sodium arsanilate (30 mg/0.1 ml/ear), one side being lesioned 3 weeks after the other. The control group received transtympanic saline solution (0.1 ml/ear) (n = 24). Spatial memory performance (Y maze and radial maze) decreased after VL. Conversely, non-spatial memory performance (object recognition) was not affected by VL. No hippocampal atrophy was observed with MRI, but density of NMDA receptors were increased in the hippocampus after VL. These findings show that the lack of vestibular information induced specific deficits in spatial memory. Additionally, quantitative autoradiographic data suggest the involvement of the glutamatergic system in spatial memory processes related to vestibular information. When studying spatial memory performances in the presence of vestibular syndrome, two-step labyrinthectomy is a suitable procedure for distinguishing between the roles of the specific components of vestibular input loss and those of impaired locomotor activity.

[Lidocaine intoxication in newborn following maternal pudendal anesthesia: report of three cases]. / Intoxication néonatale à la lidocaïne après analgésie par bloc des nerfs honteux: à propos de trois observations.

Pudendal nerve block may be indicated during instrumental delivery in situations where peridural anesthesia is unavailable. We report three cases of neonatal lidocaine intoxication following maternal pudendal block during delivery. Clinical features were hypotonia, pupillary mydriasis fixed to light, apnea, cyanosis and seizures. Two neonates required mechanical ventilation. Lidocaine was found in the serum of two babies. In all three cases, recovery was complete. The pharmacokinetics of lidocaine in a highly vascularized perineum during labor increase the risk of neonatal intoxication. A possible intoxication by local anesthetics should be considered in neonates presenting an acute distress in the delivery room.

Cyclosporine monitoring in peripheral blood mononuclear cells: feasibility and interest. A prospective study on 20 renal transplant recipients.

Cyclosporine (CsA) has potent immunosuppressive properties, reflecting its ability to block the transcription of cytokine genes (mainly interleukin 2) in CD4+ T lymphocytes, markedly improving transplantation outcomes in the past 20 years. CsA pharmacokinetic variability and renal toxicity require whole blood (WB) monitoring by 4-hour area under the drug concentration curves (AUC0-4) or 2-hour postdose concentration (C2) monitoring. Nevertheless, graft rejection can occur despite target blood levels, suggesting that WB monitoring does not guarantee optimal immunosuppression. For a decade, pharmacologists and clinicians have worked to optimize CsA doses; some authors, inspired by its mechanism of action, have proposed therapeutic drug monitoring using peripheral blood mononuclear cells (PBMC; lymphocytes and monocytes). The aim of this study was to assess the feasibility and interest of CsA monitoring in PBMC ([CsA]PBMC). We also measured in vitro distribution of CsA in CD4+ and CD4- subsets.