Effects of palmitoylethanolamide on release of mast cell peptidases and neurotrophic factors after spinal cord injury

Spinal cord injury (SCI) has a significant impact on quality of life, expectancy, and economic burden, with considerable costs associated with primary care and loss of income. The complex pathophysiology of SCI may explain the difficulty in finding a suitable therapy for limiting neuronal injury and promoting regeneration. Although innovative medical care, advances in pharmacotherapy have been limited. The aim of the present study was to carefully investigate molecular pathways and subtypes of glial cells involved in the protective effect of PEA on inflammatory reaction associated with an experimental model of SCI.The compression model induced by applying an aneurysm clip to the spinal cord in mice is closer to the human situation, since it replicates the persistence of cord compression. Spinal cord trauma was induced in mice by the application of vascular clips to the dura via a four-level T5-T8 laminectomy.Repeated PEA administration (10 mg/kg i.p., 6 and 12 h after SCI) significantly reduced the degree of the severity of spinal cord trauma through the reduction of mast cell infiltration and activation. Moreover, PEA treatment significantly reduced the activation of microglia and astrocytes expressing cannabinoid CB₂ receptor after SCI. Importantly, the protective effect of PEA involved changes in the expression of neurotrophic factors, and in spinal cord dopaminergic function.Our results enhance our understanding about mechanisms related to the anti-inflammatory property of the PEA suggesting that this N-acylethanolamine may represent a crucial therapeutic intervention both diminishing the immune/inflammatory response and promoting the initiation of neurotrophic substance after SCI.     

Cognitive development in Dravet syndrome: a retrospective, multicenter study of 26 patients

Purpose: To clarify the role of epilepsy and genetic background in determining the cognitive outcome of patients with Dravet syndrome. Methods: In this retrospective study, we reviewed the clinical history and cognitive development of 26 patients who had been followed with standardized evaluations since seizure onset. The cognitive outcome was quantified as differential general quotient (dGQ) between ages 12 and 60 months. Statistical analysis correlated the dGQ with genotype and epilepsy course. Key Findings: Epilepsy started at the mean age of 5.6 months. All patients experienced prolonged convulsive seizures, whereas absences and myoclonus were reported in 17. Cognitive outcome was poor in almost all patients; the mean dGQ was 33 points, varying from 6–77 points. The analysis of individual cognitive profiles identified seven patients in whom the dGQ was <20 points; the main clinical characteristic in this subset of patients was lack of early absences and myoclonus. The statistical analysis of the whole series failed to reveal significant differences in cognitive outcome with regard to the presence of SCN1A mutations and their type. In particular, mutation‐carrier patients with the best cognitive outcome harbored either missense or truncating mutations. Significance: Dravet syndrome encompasses different epileptic and cognitive phenotypes that probably result from both genetic and epigenetic factors. In this series, early appearance of myoclonus and absences was associated with the worst cognitive outcome.     

Immune-mediated epilepsies

A pathogenic role of immunity in epilepsies has long been suggested based on observations of the efficacy of immune-modulating treatments and, more recently, by the finding of inflammation markers including autoantibodies in individuals with a number of epileptic disorders. Clinical and experimental data suggest that both innate and adaptive immunity may be involved in epilepsy. Innate immunity represents an immediate, nonspecific host response against pathogens via activation of resident brain immune cells and inflammatory mediators. These are hypothesized to contribute to seizures and epileptogenesis. Adaptive immunity employs activation of antigen-specific B and T lymphocytes or antibodies in the context of viral infections and autoimmune disorders. In this article we critically review the evidence for pathogenic roles of adaptive immune responses in several types of epilepsy, and discuss potential mechanisms and therapeutic targets. We highlight future directions for preclinical and clinical research that are required for improved diagnosis and treatment of immune-mediated epilepsies.     

Neurotensin regulates cortical glutamate transmission by modulating N-methyl-D-aspartate receptor functional activity: an in vivo microdialysis study

The aim of the present in vivo microdialysis study was to investigate whether the tridecapeptide neurotensin (NT) influences the N-methyl-D-aspartate (NMDA) receptor-mediated increase of cortical glutamate transmission in freely moving rats. Intracortical perfusion with NT influenced local extracellular glutamate levels in a bell-shaped, concentration-dependent manner. One hundred and three hundred nanomolar NT concentrations increased glutamate levels (151% ± 7% and 124% ± 3% of basal values, respectively). Higher (1,000 nM) and lower (10 nM) NT concentrations did not alter extracellular glutamate levels. The NT receptor antagonist SR48692 (100 nM) prevented the NT (100 nM)-induced increase in glutamate levels. NMDA (100 and 500 μM) perfusion induced a concentration-dependent increase in extracellular glutamate levels, the lower 10 μM NMDA concentration being ineffective. When NT (10 nM, a concentration by itself ineffective) was added in combination with NMDA (100 μM) to the perfusion medium, a significant greater increase in extracellular glutamate levels (169% ± 7%) was observed with respect to the increase induced by NMDA (100 μM) alone (139% ± 4%). SR48692 (100 nM) counteracted the increase in glutamate levels induced by the treatment with NT (10 nM) plus NMDA (100 μM). The enhancement of cortical glutamate levels induced by NMDA (100 and 500 μM) was partially antagonized by the presence of SR48692, at a concentration (100 nM) that by itself was ineffective in modulating glutamate release. These findings indicate that NT plays a relevant role in the regulation of cortical glutamatergic transmission, especially by modulating the functional activity of cortical NMDA receptors. A possible role in glutamate-mediated neurotoxicity is suggested.     

The pedunculopontine tegmental nucleus: implications for a role in modulating spinal cord motoneuron excitability

There is evidence that deep brain stimulation (DBS) of the pedunculopontine tegmental nucleus (PPTg) improves parkinsonian motor signs. The mechanisms that mediate these effects and the modifications that occur in the PPTg in Parkinson’s disease (PD) are not fully known and are the object of current debate. The aim of this paper was to critically review available data with respect to (1) the presence of PPTg neurons linked to reticulospinal projections, (2) the involvement of these neurons in modulating spinal reflexes, and (3) the participation of fibers close to or within the PPTg region in such modulation. The PPTg neurons are distributed in a large pontotegmental region, stimulation of which can evoke activity in hindlimb, shoulder and neck muscles, and potentiate motor responses evoked by stimulation of dorsal roots. This influence seems to be carried out by fast-conducting descending fibers, which likely run in the medial reticulospinal pathway. It is yet unclear which neurotransmitters are involved and on which elements of the gray matter of the spinal cord PPTg fibers synapse. The modulation of spinal cord activity which can be achieved by stimulating the PPTg region seems to be mediated not only by PPTg neurons, but also by tecto-reticular fibers which run in the pontotegmental area, and which likely are activated during PPTg-DBS. The importance of these fibers is discussed taking into account the degeneration of PPTg neurons in PD and the benefits in gait and postural control that PPTg-DBS exerts in PD. The potential usefulness of PPTg-DBS in other neurodegenerative disorders characterized by neuronal loss in the brainstem is also considered.     

Presenilin-2 gene mutation presenting as Lewy Body dementia?

Neurological Sciences -     

Clinical course and variability of non-Rasmussen, nonstroke motor and sensory epilepsia partialis continua: a European survey and analysis of 65 cases

Purpose: To gain new insights into the clinical presentation, causes, treatment and prognosis of epilepsia partialis continua (EPC), and to develop hypotheses to be tested in a prospective investigation. Methods: In this retrospective multicenter study, all cases were included that fulfilled these criteria: constantly repeated fragments of epileptic seizures, with preserved consciousness, lasting ≥1 h and representing locally restricted motor or sensory epileptic activity. Single episodes were included when they lasted for a minimum of 1 day. EPC with Rasmussen syndrome and acute stroke were excluded. Key Findings: Three time courses with two subtypes each were distinguished, that is, EPC as a solitary event (de novo or in preexistent epilepsy); chronic repetitive nonprogressive EPC (with frequent or rare episodes); and chronic persistent nonprogressive EPC (primarily or evolving out of an episodic course). These were unrelated to etiologies (morphologic lesions 34%, inflammatory 29%, systemic disorders 9%, idiopathic 5%, unknown 23%). Precipitation and inhibition of seizures is a frequent feature of EPC. Levetiracetam and topiramate have improved the possibilities for pharmacotherapy. Topiramate seems to be particularly effective with dysontogenetic etiologies. Significance: The existence of several clearly distinct courses of nonprogressive EPC is a new finding. These distinctions will be further investigated in a prospective study with precise protocols for electroencephalography (EEG), imaging, and other studies. This should better establish the relation of motor and somatosensory EPC; further clarify the relations, pathogenesis, and significance of the different types and their etiologies; and possibly identify more semiologic variants. It should also provide more precise knowledge about therapy and modification of ictogenesis by external stimuli.     

Tumor necrosis factor promoter polymorphism TNF*‐857 is a risk allele for psoriatic arthritis independent of the PSORS1 locus

Objective

The strongest susceptibility locus of psoriatic arthritis (PsA) is within the major histocompatibility complex (MHC) region (psoriasis susceptibility region 1, or PSORS1), and HLA–Cw*06:02 has been reported as the PSORS1 susceptibility allele. Non‐HLA genes within the MHC region have also been implicated in PsA, but because of the strong linkage disequilibrium at chromosome 6p21, it is difficult to make a distinction between susceptibility alleles and linked markers. Recent studies have demonstrated that the association between PsA and the tumor necrosis factor (TNF) promoter polymorphism TNF*‐857 is independent of PSORS1. The aim of this study was to replicate the independent association of TNF*‐857 in patients with PsA.

Methods

A total of 909 patients with PsA and 1,315 healthy controls originating from the UK, Germany, and Italy were typed for TNF*‐857 and for the estimated risk alleles of HLA–Cw*06:02.

Results

Overall, the results of genotyping in these 3 case–control cohorts replicated the finding that the frequency of carriers of TNF*‐857 TT/CT who were negative for the PSORS1 risk allele was significantly higher among patients with PsA compared with control subjects (30% versus 21%; P = 9.17 × 10⁻⁵).

Conclusion

The results of this collaborative study indicate that TNF*‐857T is a susceptibility allele for PsA independent of the PSORS1 allele.

     

In vivo remineralising effect of GC tooth mousse on early dental enamel lesions: SEM analysis

Objective: Casein phosphopeptide‐amorphous calcium phosphate nanocomplexes (CPP‐ACP) exhibit anticariogenic potential in laboratory, animal and human experiments. The remineralising potential of synthetic CPPs on early enamel caries was investigated. Design: In vivo study. Setting: University of Naples ‘Federico II’, School of Dentistry, Department of Paediatric Dentistry, 2010, Italy. Participants: 40 volunteers (age range 10–16 years) were recruited and divided in two groups of 20 (Group A and B). Interventions: In Group A subjects two demineralised enamel specimens were placed on the buccal surfaces of the first molars and subjects were instructed to apply a commercial product containing CPPs (GC Tooth Mousse) only on the right‐sided specimen and a placebo mousse on the left, for 1 month. In Group B subjects two enamel specimens were similarly placed into the mouth and used as controls. Results: SEM analysis revealed a diffuse and homogeneous mineral coating, reducing the surface alterations only in the demineralised specimens treated with synthetic CPPs into the mouth. Conclusions: Results demonstrate that CPPs are able to promote remineralisation of early enamel lesions.