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A better understanding of the molecular mechanisms that participate in the development and clinical manifestations of schizophrenia can lead to improve our ability to diagnose and treat this disease. Previous data strongly associated the levels of deregulated ADAMTS2 expression in peripheral blood mononuclear cells (PBMCs) from patients at first episode of psychosis (up) as well as in clinical responders to treatment with antipsychotic drugs (down). In this current work, we performed an independent validation of such data and studied the mechanisms implicated in the control of ADAMTS2 gene expression. Using a new cohort of drug-naïve schizophrenia patients with clinical follow-up, we confirmed that the expression of ADAMTS2 was highly upregulated in PBMCs at the onset (drug-naïve patients) and downregulated, in clinical responders, after treatment with antipsychotics. Mechanistically, ADAMTS2 expression was activated by dopaminergic signalling (D 1 -class receptors) and downstream by cAMP/CREB and mitogen-activated protein kinase (MAPK)/ERK signalling. Incubation with antipsychotic drugs and selective PKA and MEK inhibitors abrogated D 1 -mediated activation of ADAMTS2 in neuronal-like cells. Thus, D 1 receptors signalling towards CREB activation might participate in the onset and clinical responses to therapy in schizophrenia patients, by controlling ADAMTS2 expression and activity. The unbiased investigation of molecular mechanisms triggered by antipsychotic drugs may provide a new landscape of novel targets potentially associated with clinical efficacy.

Targeted treatment of advanced melanoma could benefit from the precise molecular characterization of melanoma samples. Using a melanoma-specific selection of 217 genes, we performed targeted deep sequencing of a series of biopsies, from advanced melanoma cases, with a Breslow index of ≥ 4 mm, and/or with a loco-regional infiltration in lymph nodes or presenting distant metastasis, as well of a collection of human cell lines. This approach detected 3-4 mutations per case, constituting unique mutational signatures associated with specific inhibitor sensitivity. Functionally, case-specific combinations of inhibitors that simultaneously targeted MAPK-dependent and MAPK-independent mechanisms were most effective at inhibiting melanoma growth, against each specific mutational background. These observations were challenged by characterizing a freshly resected biopsy from a metastatic lesion located in the skin and soft tissue and by testing its associated therapy ex vivo and in vivo using melanocytes and patient-derived xenografted mice, respectively. The results show that upon mutational characterization of advanced melanoma patients, specific mutational profiles can be used for selecting drugs that simultaneously target several deregulated genes/pathways involved in tumor generation or progression.

Transforming growth factor-β1 (TGF-β1) protects against neuroinflammatory events underlying neuropathic pain. TGF-β signaling enhancement is a phenotypic characteristic of mice lacking the TGF-β pseudoreceptor BAMBI (BMP and activin membrane-bound inhibitor), which leads to an increased synaptic release of opioid peptides and to a naloxone-reversible hypoalgesic/antiallodynic phenotype. Herein, we investigated the following: (1) the effects of BAMBI deficiency on opioid receptor expression, functional efficacy, and analgesic responses to endogenous and exogenous opioids; and (2) the involvement of the opioid system in the antiallodynic effect of TGF-β1. BAMBI-KO mice were subjected to neuropathic pain by sciatic nerve crash injury (SNI). Gene (PCR) and protein (Western blot) expressions of μ- and δ-opioid receptors were determined in the spinal cord. The inhibitory effects of agonists on the adenylyl cyclase pathway were investigated. Two weeks after SNI, wild-type mice developed mechanical allodynia and the functionality of μ-opioid receptors was reduced. By this time, BAMBI-KO mice were protected against allodynia and exhibited increased expression and function of opioid receptors. Four weeks after SNI, when mice of both genotypes had developed neuropathic pain, the analgesic responses induced by morphine and RB101 (an inhibitor of enkephalin-degrading enzymes, which increases the synaptic levels of enkephalins) were enhanced in BAMBI-KO mice. Similar results were obtained in the formalin-induced chemical-inflammatory pain model. Subcutaneous TGF-β1 infusion prevented pain development after SNI. The antiallodynic effect of TGF-β1 was naloxone-sensitive. In conclusion, modulation of the endogenous opioid system by TGF-β signaling improves the analgesic effectiveness of exogenous and endogenous opioids under pathological pain conditions.

Background: About 75% of persons with ASIA (American Spinal Injury Association) Impairment Scale C and D incomplete spinal cord injury (SCI) achieve walking ability., Objective: To compare a walking reeducation program using Lokomat with conventional overground training among individuals with incomplete SCI of both traumatic and nontraumatic etiology., Methods: A total of 80 participants from 3 to 6 months after onset admitted to 1 site for rehabilitation were included in a single-blind randomized clinical trial of 2 parallel groups, with blind evaluation by independent observers. Patients received 40 walking reeducation sessions of equal time using a Lokomat program with overground practice or overground mobility therapy alone. Primary measurements of outcome were walking speed and the Walking Index for Spinal Cord Injury (WISCI II). Secondary outcomes were the 6-minute walk test, locomotor section of the Functional Independence Measure, Lower Extremity Motor Score (LEMS), Ashworth Scale, and Visual Analog Scale for pain., Results: No significant differences were found at entry between treatment groups. Walking speed for Lokomat (0.4m/s [0.6-0.2]) and overground therapy (0.3m/s [0.5-0.2]) groups did not differ. The WISCI II for the Lokomat group (16 [8.5-19]) was better than for overground therapy (9 [8-16]). The 6-minute walk test and LEMS displayed significant differences in favor of Lokomat therapy but were not corrected for multiple comparisons., Conclusions: Robotic-assisted training was equivalent to conventional walk training in patients with a variety of nonprogressive spinal cord pathologies for walking speed, but the need for orthotics and assistive devices was reduced, perhaps because of greater leg strength in the robotic group.

Ts65Dn (TS) mice exhibit several phenotypic characteristics of human Down syndrome, including an increased brain expression of amyloid-beta protein precursor (AbetaPP) and cognitive disturbances. Aberrant N-methyl-D-aspartate (NMDA) receptor signaling has been suspected in TS mice, due to an impaired generation of hippocampal long-term potentiation (LTP). Memantine, an uncompetitive NMDA receptor antagonist approved for the treatment of moderate to severe Alzheimer's disease, is known to normalize LTP and improve cognition in transgenic mice with high brain levels of AbetaPP and amyloid-beta protein. It has recently been demonstrated that acute injections of memantine rescue performance deficits of TS mice on a fear conditioning test. Here we show that oral treatment of aged TS mice with a clinically relevant dose of memantine (30 mg/kg/day for 9 weeks) improved spatial learning in the water maze task and slightly reduced brain AbetaPP levels. We also found that TS mice exhibited a significantly reduced granule cell count and vesicular glutamate transporter-1 (VGLUT1) labeling compared to disomic control mice. After memantine treatment, the levels of hippocampal VGLUT1 were significantly increased, reaching the levels observed in vehicle treated-control animals. Memantine did not significantly affect granule cell density. These data indicate that memantine may normalize several phenotypic abnormalities in TS mice, many of which--such as impaired cognition--are also associated with Down syndrome and Alzheimer's disease.

Introduction: A spinal cord injury involves the loss or alteration of motor patterns in walking, the recovery of which depends partly on the rearrangement of the preserved neural circuits. AIM. To evaluate the changes that take place in the gait of patients with incomplete spinal cord injuries who were treated with a robotic walking system in association with conventional therapy., Patients and Methods: The study conducted was an open-label, prospective, descriptive trial with statistical inference in patients with C2-L3 spinal cord injuries that were classified as degrees C and D according to the American Spinal Injury Association (ASIA) scale. The variables that were analysed on the first and the last day of the study were: number of walkers, 10-m gait test, the Walking Index for Spinal Cord Injury scale revision, technical aids, muscle balance in the lower limbs, locomotor subscale of the measure of functional independence, modified Ashworth scale for spasticity and the visual analogue scale for pain. At the end, data were recorded from the impression of change scale. The analysis was conducted by means of Student's t, chi squared and Pearson's correlation; p < or = 0.05., Results: Forty-five patients, with a mean age of 44 +/- 14.3 years, finished the study; 76% were males, injury was caused by trauma in 58% of cases, and the time of progression was 139 +/- 70 days. Statistically significant increases were observed in the number of subjects capable of walking, walking speed, less need for technical aids, strength in the lower limbs and independence in activities of daily living., Conclusions: Treatment using the robotic system in association with conventional therapy improves walking capacity in patients with incomplete spinal cord injuries.

Objective: We review the molecular basis of epileptogenesis and the new perspectives in the treatment of epilepsy., Development: Epileptogenesis are the molecular and cellular events producing the disordered firing of a subpopulation of neurons resulting in periodic seizures. Epilepsies may be due to genetic and acquired factors. Some idiopathic epilepsies are due to mutant genes coding voltage gated sodium and potassium channels, GABAA receptor chloride channels and nicotinic acetylcholine receptor sodium channels. Genetic defects also produce epilepsy secondary to either neuronal developmental or metabolic abnormalities, and may contribute to acquired epilepsy. Events observed in both animal and human acquired epilepsies are an increase in glutamate levels and NMDA receptor sensitivity, selective lost of pyramidal neurons, mossy fibre sprouting and neosinaptogenesis. There is also a reduction in inhibitory control due to lost of GABAergic interneurons, and a decrease in GABA levels and GABAA receptor sensitivity. Hyperexcitability may be also due to reduction in glial ATPasa activity, increase in astrocytes gap junctions, and decrease in extracellular calcium. Chandelier GABAergic interneuron microlesions and an hyperexcitable thalamus are key in spread of partial seizures. Absences may be caused by cortex hyperexcitability and genetic abnormalities in thalamic voltage gated T calcium channels. Brain stem is key in convulsive seizures. The role of voltage gated potassium, sodium and calcium channels, and GABAergic and glutamatergic neurotransmission in epileptogenesis and treatment of epilepsies are revised. The role of other neurotransmitters and neuromodulators, second messengers, and immediate early genes and neurotrophins are also commented., Conclusion: Understanding the molecular basis of epileptogenesis should lead to the rational design of drugs both to prevent the development of epilepsy, and minimize hyperexcitability which may be the result of a genetic or acquired disorder.

1. We have previously demonstrated that chronic and simultaneous treatment of rats with the mu-opioid receptor agonist sufentanil and the Ca(2+) channel blocker nimodipine, not only prevented tolerance development, but the animals became supersensitive to the antinociceptive effect of the opioid. The focus of the present work was to determine the possible involvement of cross interactions between the adenylyl cyclase pathway and L-type voltage-sensitive Ca(2+)-channels, in modulating the switch from opioid tolerance into supersensitivity. 2. The modulatory effect of sufentanil on adenylyl cyclase activity was determined by measuring cyclic AMP production in slices from the cortex of rats rendered tolerant or supersensitive to the antinociceptive effect of the opioid. Tolerance was induced by chronic infusion of sufentanil, at a rate of 2 microg h(-1), for 7 days. Supersensitivity was induced by concurrent infusion of sufentanil (2 microg h(-1)) and nimodipine (1 microg h(-1)) for 7 days. Antinociception was evaluated by the tail-flick test. 3. Tolerance to the analgesic effect of sufentanil was associated with a significant reduction in the response of adenylyl cyclase to forskolin. Furthermore, the effect of the opioid on forskolin-induced cyclic AMP accumulation was abolished. On the other hand, supersensitivity to the analgesic effect of the opioid was associated with an increase in both, the adenylyl cyclase response to forskolin, and the opioid inhibition of cyclic AMP production. 4. We suggest that sustained L-type Ca(2+) channel blockade may result in changes in the adenylyl cyclase effector system triggered by mu-opioid receptor activation, leading to the switch from opioid tolerance into supersensitivity.

Purpose: To analyze the time course of the effects of vigabatrin (VGB) on brain gamma-aminobutyric acid (GABA), and its relation with 4-aminobutyrate-2-ketoglutarate amino-transferase (GABA-T) in brain and platelets., Methods: Blood and brain samples were collected at 4, 24, 48, and 72 h after a single dose and after 3 and 8 days of treatment with 200 mg/kg of VGB in rats., Results: Time courses of the GABAergic effects of VGB were different after single and multiple doses: with multiple doses, the inhibition of brain GABA-T was quicker and longer, the inhibition of platelet GABA-T was greater and longer, the increase in brain GABA was greater, and recovery began earlier. After pooling the data obtained at 4, 24, 48, and 72 h, we observed a power correlation between the increase in brain GABA in individual rats as percentage of the control and both the inhibition of brain GABA-T after a single dose of VGB (r = -0.40; p < 0.05), and the inhibition of platelet GABA-T after 3 days (r = -0.48; p < 0.01) and 8 days of treatment (r = -0.53; p < 0.01). When all data after single and multiple doses were pooled, the increase in brain GABA correlated better with the inhibition of GABA-T in platelets (r = -0.62; p < 0.001) than in brain (r = -0.38; p < 0.001). Platelet GABA-T correlated with brain GABA at 4 h (r = -0.64; p < 0.001) and 24 h (r = -0.66; p < 0.001) but not at 48 and 72 h., Conclusions: Platelet GABA-T reflects the time course of the increase in brain GABA better than does brain GABA-T after multiple doses of VGB in rats.

We report the relationship of GABA-transaminase inhibition in platelets and brain with the increase in brain gamma-aminobutyric acid (GABA), as percents of the control, at 24 h after single and after 3 and 8 days of treatment with increasing doses (1, 3, 10, 30, 100 and 300 mg kg(-1) day(-1) of vigabatrin in rats. The inhibition of GABA-transaminase in platelets correlated at least as well as that in brain with the increase in brain GABA after 3 days (r = - 0.87 vs. r = -0.78), and 8 days of treatment (r = -0.77 vs. r = -0.74), and when the data of single and multiple doses were pooled (r = -0.77 vs. r = -0.75). The correlation between platelet GABA-transaminase and brain GABA fitted to a power curve, the increase in brain GABA being significant only when platelet GABA-transaminase was inhibited to less than 50% of the control. Our results suggest that platelet GABA-transaminase could be a peripheral marker of the effect of vigabatrin on brain GABA in rats.

The effects of adding vigabatrin (GVG) to the antiepileptic regimens of 16 children with refractory epilepsy have been studied. One-half of the regimens included sodium valproate (VPA). Parameters studied were seizure reduction, platelet GABA-T activity, and steady-state plasma concentrations (CSS) of GVG and VPA. Add-on GVG reduced the seizure frequency both in patients receiving VPA (from 42.9 to 4.5 seizures/month, p < 0.01) and in those without VPA (from 60.0 to 31.7 seizures/month, p < 0.05). GVG also reduced GABA-T activity in both groups (from 19.4 to 5.4, p < 0.001 and from 8.3 to 4.5 pmol/min/mg of protein, p < 0.05, respectively). Seizure reduction and GABA-T inhibition were greater in patients taking VPA than in those who were not. In patients receiving VPA, no significant changes were observed in VPA CSS values before and after the addition of GVG. On the other hand, no differences were found in GVG CSS values between patients with and without VPA. It is concluded that the coadministration of GVG to valproate reduces the frequency of seizures in refractory epileptic children and does not affect the steady-state plasma concentrations of either drug. Therefore, their association could be useful in clinical practice.

The relationship between vigabatrin gamma-vinyl GABA (GVG, vigabatrin) daily dosage or steady-state plasma concentrations (CSS), platelet GABA-transaminase (GABA-T) inhibition, and seizure reduction were studied in 16 children with refractory epilepsy. After 2 months of observation and 1 month of single-blind add-on placebo, a fixed GVG dosage was added for 2 months. The dosage was then adjusted in two 2-month periods each, based on the patient's clinical response. In the fixed-dose period, GVG dosages of 56.8 mg/kg/day and CSS of 8.1 mg/L reduced GABA-T activity from 13.9 to 5.1 pmol/min/mg protein (p less than 0.001) and that of seizures from 51.4 to 22.3 seizures per month (p less than 0.01). Seizure reduction was correlated with dosage (r = 0.83, p less than 0.001), but not with CSS or with platelet GABA-T inhibition. After the GVG dose-adjustment periods, in which dosages of 84.4 mg/kg/day and CSS of 10.6 mg/L were reached, only a slight reduction was observed in both GABA-T activity (from 5.1 to 4.9 pmol/min/mg protein) and seizures (from 22.3 to 18.1 seizures per month). In GVG-responsive patients (excluding placebo-sensitive and GVG-resistant patients), a greater reduction of seizures was achieved (from 17.0 to 7.1 seizures per month, p less than 0.05), which was not accompanied by greater inhibition of GABA-T. GVG treatment in children should be started with a dosage of 50 mg/kg/day, increased to 75 or even 100 mg/kg/day when a partial response is observed. If seizures do not improve or if they become worse, the patient should be considered resistant and GVG should be discontinued.

Unlabelled: The effects of increasing (50-1600 mg/kg/day) doses of vigabatrin (GVG) both as single doses and after 8 or 28 days of treatment have been studied in 19 groups of 10 adult Wistar rats. The parameters studied were brain gamma-aminobutyric acid-transaminase (GABA-T) activity, GABA concentration and L-glutamate decarboxylase (GAD) activity. Single increasing doses of GVG progressively inhibited GABA-T activity, but a residual activity of about 40% was observed with the highest doses. GABA concentration increased in a dose-dependent manner but a ceiling was not reached. GAD activity was slightly inhibited at low doses and stimulated at high ones. When treatment was continued for 8 days, more marked effects of GVG on GABA-T and GABA, a more severe toxicity and higher GVG plasma concentrations were observed. GAD was inhibited instead of stimulated by high GVG doses. After 28 days of treatment the effects of GVG on GABA-T and GABA were similar to those after 8 days. However, toxic effects decreased and lower GVG plasma concentrations were found., In Conclusion: (a) the more marked brain GABAergic effects observed after 8 days of treatment with GVG may explain the greater anticonvulsant effects observed by others in animals, and (b) GVG plasma concentrations correlate well with changes in brain GABA-T and GABA, and may partly explain changes in the effects of GVG related to the length of treatment.

Vigabatrin (gamma-vinyl-GABA, GVG) is an inhibitor of brain GABA transaminase (GABA-T) that also inhibits platelet GABA-T in rats and humans. We have compared the effects of single and multiple doses of GVG on both enzymes in 19 groups of 10 adult male Wistar rats, treated with increasing GVG doses (0-1,600 mg/kg/day) for 1, 8, and 28 days. The platelet GABA-T was more sensitive to the inhibitory effects of GVG than the brain enzyme was especially with low dosages of GVG. After 8 days of treatment, higher GVG plasma levels and a higher inhibition of both enzymes were shown. However, after 28 days, lower GVG plasma levels and similar inhibition of both enzymes compared to the eighth day were found. Correlations between platelet and brain GABA-T for individual rats were statistically significant after 1 day (r = 0.40, p less than 0.01) but not after 8 and 28 days of treatment because of the total inhibition of platelet GABA-T and only partial inhibition of brain GABA-T. We concluded the following: (a) platelet GABA-T is more inhibited than brain GABA-T when low doses of GVG are used and (b) multiple doses reach a higher inhibition of both enzymes than single doses, which could be explained by an increase in GVG concentrations.