Outcome of distal tibia physeal fractures: a review of cases as related to risk factors.

INTRODUCTION: The physeal fractures represent the 20-30% of all fractures of the child. The distal tibial physis is the third most frequently injured. The most important complication is the premature physeal closure (PPC). Aim of this study is to evaluate risk factors that can influence the outcome like fracture pattern, fracture displacement, mechanism of injury and treatment method. MATERIAL AND METHODS: The records of 46 patients treated for distal tibia physeal fractures between 2003 and 2013 were reviewed. Initial injury radiographs were categorized according to Salter-Harris and Dias-Tachdjian classifications and the initial and post-treatment fracture displacementwas measured. Any complex fractures had preoperative CT for additional assessment. Three different types of treatment were compared: closed reduction and casting versus closed reduction and percutaneous pinning versus ORIF. RESULTS: Therewas significantly less residual displacement in patients who had ORIF versus those who had closed reduction and percutaneous Kirschner wires or plaster only. In fractures with an intact fibula, we found significantly less initial and residual displacement. The Dias-Tachdjian classification is significantly correlated with the displacement. Patients studied with CT show a less degree of post reduction displacement. At the final follow-up we found only one PPC as complication. CONCLUSION: The physeal fractures are very common in children and the main goal is to avoid any complications. It is clear that the development of complications after distal tibial fractures is due to multiple contributing factors like skeletal maturity, severity of injury, fracture type, degree of comminution and displacement aswell as adequacy of reduction. A premature physeal closure is the most common complication. The fibula fracture can play an important role in initial displacement. The presence of an intact fibula and a good anatomical reduction have a significant positive influence on fracture outcome.

Potential anxiolytic- and antidepressant-like effects of salvinorin A, the main active ingredient of Salvia divinorum, in rodents.

BACKGROUND AND PURPOSE: Drugs targeting brain kappa-opioid receptors produce profound alterations in mood. In the present study we investigated the possible anxiolytic- and antidepressant-like effects of the kappa-opioid receptor agonist salvinorin A, the main active ingredient of Salvia divinorum, in rats and mice. EXPERIMENTAL APPROACH: Experiments were performed on male Sprague-Dawley rats or male Albino Swiss mice. The anxiolytic-like effects were tested by using the elevated plus maze, in rats. The antidepressant-like effect was estimated through the forced swim (rats) and the tail suspension (mice) test. kappa-Opioid receptor involvement was investigated pretreating animals with the kappa-opioid receptor antagonist, nor-binaltorphimine (1 or 10 mgxkg(-1)), while direct or indirect activity at CB(1) cannabinoid receptors was evaluated with the CB(1) cannabinoid receptor antagonist, N-(piperidin-1-yl) -5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251, 0.5 or 3 mgxkg(-1)), binding to striatal membranes of naïve rats and assay of fatty acid amide hydrolase in prefrontal cortex, hippocampus and amygdala. KEY RESULTS: Salvinorin A, given s.c. (0.001-1000 microgxkg(-1)), exhibited both anxiolytic- and antidepressant-like effects that were prevented by nor-binaltorphimine or AM251 (0.5 or 3 mgxkg(-1)). Salvinorin A reduced fatty acid amide hydrolase activity in amygdala but had very weak affinity for cannabinoid CB(1) receptors. CONCLUSIONS AND IMPLICATIONS: The anxiolytic- and antidepressant-like effects of Salvinorin A are mediated by both kappa-opioid and endocannabinoid systems and may partly explain the subjective symptoms reported by recreational users of S. divinorum.

Expression of mutant beta2 nicotinic receptors during development is crucial for epileptogenesis.

Autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) is a focal form of epilepsy characterized by seizures occurring during non-REM sleep. We have developed and characterized the first mouse model for ADNFLE type III carrying the V287L mutation of the beta2 subunit of neuronal nicotinic receptor. Mice expressing mutant receptors show a spontaneous epileptic phenotype by electroencephalography with very frequent interictal spikes and seizures. Expression of the mutant beta2 subunit is driven by a neuronal-specific tetracycline-controlled promoter, which allows planned silencing of transgene expression in a reversible fashion and tracking the involvement of mutant receptor in crucial phases of epileptogenesis. We found that restricted silencing during development is sufficient to prevent the occurrence of epileptic seizures in adulthood. Our data indicate that mutant nicotinic receptors are responsible for abnormal formation of neuronal circuits and/or long-lasting alteration of network assembly in the developing brain, thus leading to epilepsy.

Diazepam protects against the enhanced toxicity of cocaine adulterated with atropine.

We examined the toxicity of cocatropine (cocaine/atropine mixture) and the therapeutic potential of diazepam on some behavioral and physiological parameters in rats. Atropine (20 and 60 mg/kg) or cocaine (40 mg/kg) alone did not induce any seizure or death, but the combination significantly increased both, after both acute and binge treatment. There was a significant increase of EEG mean total spectral power in cocatropine- in comparison with cocaine-treated animals. Hyperlocomotion was observed in non-seizuring rats treated with cocaine or cocatropine. Cocaine, atropine 60, and cocatropine (40 + 20 and 40 + 60) all induced hyperthermic effects in non-seizuring rats, while cocatropine (40 + 60)-seizuring animals had hypothermia. An initial hypertensive and tachycardiac effect within 15 min was followed by a secondary fall in the cocatropine (40 + 60) group. Cocatropine toxicity was partially or fully reversed by diazepam (5 mg/kg), given intraperitoneally after the first seizure. The present findings provide, for the first time, details of a synergistic toxic effect of the cocaine/atropine mixture and of the potential of diazepam for treating cocatropine-related hospital emergencies.

Involvement of kappa-opioid and endocannabinoid system on Salvinorin A-induced reward.

BACKGROUND: The recreational drug, Salvinorin A, derived from the plant of Salvia divinorum, is a potent and selective kappa-opioid receptor agonist. The abuse of selective k-agonists is a novel phenomenon, the mechanism of which is not fully understood. METHODS: We investigated salvinorin A given SC on the conditioned place preference (.05-160 microg/kg) and intracerebroventricular (ICV) self-administration (.01-1 microg/infusion) paradigms, in Wistar rats. RESULTS: The present results demonstrate the rewarding effects of Salvinorin A in a range of doses between .1 and 40 microg/kg SC for conditioned place preference test and .1-.5 microg/infusion for ICV self-administration. Highest doses (160 microg/kg for conditioned place preference test and 1 microg/infusion for ICV self-administration) were aversive. The rewarding effect was antagonized by intraperitoneal (IP) pretreatment with the cannabinoid CB(1) receptor antagonist, rimonabant [N-piperidino-5-(4-chlorophenyl)1-(2,4-dichloro phenyl)-4 methyl pyrazole 3-carboxamide] (1 mg/kg), and the kappa-opioid receptor antagonist, nor-binaltorphimine (nor-BNI) (10 mg/kg). In the shell of nucleus accumbens, dopamine extracellular levels were increased after administration of salvinorin A (40 microg/kg SC), reaching a maximum value of about 150%. CONCLUSIONS: These data provide the demonstration of the rewarding effects of Salvinorin A through an interaction between kappa-opioid and (endo)cannabinoid system in rats.

Hallucinatory and rewarding effect of salvinorin A in zebrafish: kappa-opioid and CB1-cannabinoid receptor involvement.

RATIONALE: The hallucinatory effect and potential abuse of salvinorin A, the major ingredient of Salvia divinorum, has not been documented in animals. OBJECTIVE: The effects of salvinorin A on the zebrafish (Danio rerio) model, through its swimming behavior and conditioned place preference (CPP) task, was studied. MATERIALS AND METHODS: Swimming activity was determined in a squared observational chamber after an i.m. treatment of salvinorin A (0.1-10 microg/kg). For the CPP test, zebrafish were given salvinorin A (0.2 and 1 microg/kg) or vehicle and evaluated in a two-compartment chamber. RESULTS: Salvinorin A (0.1 and 0.2 microg/kg) induced accelerated swimming behavior in comparison with vehicle, whereas a "trance-like" effect, at doses as 5 and 10 microg/kg, was obtained. Pretreatment with the kappa-opioid antagonist, nor-binaltorphimine (nor-BNI; 10 mg/kg) and the cannabinoid type 1 (CB(1)) antagonist, rimonabant (1 mg/kg), blocked salvinorin A-induced both stimulating and depressive effects obtained at a dose of 0.2 and 10 microg/kg, respectively. In the CPP test, salvinorin A (0.2 and 0.5 microg/kg) produced an increase in the time spent in the drug-associated compartment. A dose of 1 microg/kg produced no effect, whereas a dose of 80 microg/kg induced aversion. Pretreatment with nor-BNI or rimonabant fully reversed the reinforcing properties of salvinorin A (0.5 microg/kg). CONCLUSIONS: Taken together, these results indicate that salvinorin A, as is sometimes reported in humans, exhibits rewarding effects, independently from its motor activity, suggesting the usefulness of the zebrafish model to study addictive behavior. These effects appear mediated by activation of both kappa-opioid and cannabinoid CB(1) receptors.

5-HT1A receptors are involved in the anxiolytic effect of Delta9-tetrahydrocannabinol and AM 404, the anandamide transport inhibitor, in Sprague-Dawley rats.

The mechanism mediating the effects of cannabinoids on anxiety-related responses appear to involve cannabinoid CB1 and non-CB1 receptors. However, other neurotransmitters may play a role in such effect. This study shows evidence of an interaction between endocannabinoid system and serotonin (5-HT), 1A receptor subtype on anxiety-like behavior in Sprague-Dawley rats. The exogenous cannabinoid agonist, Delta9-tetrahydrocannabinol (THC), and N-(4-hydroxyphenyl)-arachidonylamide, the anandamide transporter inhibitor (AM 404) were evaluated in the elevated plus maze test. THC (0.075-0.75 mg/kg i.p.), given 30 min and AM 404 (0.75-1.25 mg/kg i. p.), given 60 min before the test, exhibited a dose-response anxiolytic effect evaluated in terms of increase in the percentage of total entries and time spent in the open and decrease of total entries and time spent in the closed arms. The anxiolytic effect obtained with the maximal active dose of both THC (0.75 mg/kg) and AM 404 (1.25 mg/kg) was blocked by the 5-HT1A receptor antagonist, N-[2-[4-(2-methoxyphenyl) piperazin-1-yl]ethyl]-N-pyridin-2-yl-cyclohexanecarboxamide dihydro chloride (WAY-100635 (300 microg/kg, s.c.), given 30 min before THC or 15 min before AM 404. The combination of an ineffective dose of THC (0.015 mg/kg) or AM 404 (0.015 mg/kg) on anxiety-related responses with an ineffective dose of the 5HT(1A) receptor agonist, 8-Hydroxy-2-(di-n-propylamino) tetralin hydrobromide (8-OH-DPAT) (7.5 microg/kg, i.p.), led to a synergistic effect. No interference with spontaneous motor activity, evaluated in an activity cage for 5 min, in rats given the drugs alone or in combination, was found. These data suggest that the anxiolytic effect produced by endo- and eso-cannabinoids is modulated by 5-HT1A receptors.

Vanilloid VR1 receptor is involved in rimonabant-induced neuroprotection.

Recently, a potential neuroprotective effect of rimonabant, independent of the CB1 receptor interaction, has been proposed. In the present study, the role of transient receptor potential channel vanilloid subfamily member 1, named VR1, on neuroprotective effect of rimonabant, on global cerebral ischemia in gerbils, was investigated. Rimonabant (0.05-3 mg kg-1), given i.p. 5 min after recirculation, dose dependently antagonized the ischemia-induced decrease in electroencephalographic (EEG) total spectral power and restored relative frequency band distribution 7 days after ischemia. Rimonabant (0.125-0.5 mg kg-1) fully prevented ischemia-induced hyperlocomotion 1 day after ischemia and memory impairment evaluated in a passive avoidance task, 3 days after ischemia. At 7 days after ischemia, the survival of pyramidal cells, in the CA1 subfield, was respectively 91 and 96%, in the animals given rimonabant 0.25 and 0.5 mg kg-1, compared to the vehicle group. Higher doses were not protective. The protection induced by rimonabant followed a bell-shaped curve, the maximal active doses being 0.25 and 0.5 mg kg-1. Capsazepine (0.01 mg kg-1), a selective VR1 vanilloid receptor antagonist, completely reversed rimonabant-induced neuroprotective effects against EEG flattening, memory impairment and CA1 hippocampal neuronal loss. These findings suggest that VR1 vanilloid receptors are involved in rimonabant's neuroprotection even if other mechanisms can contribute to this effect.