Study of inelastic nuclear interactions of 400 GeV/c protons in bent silicon crystals for beam steering purposes.

Inelastic nuclear interaction probability of 400 GeV/c protons interacting with bent silicon crystals was investigated, in particular for both types of crystals installed at the CERN Large Hadron Collider for beam collimation purposes. In comparison to amorphous scattering interaction, in planar channeling this probability is ∼ 36 % for the quasi-mosaic type (planes (111)), and ∼ 27 % for the strip type (planes (110)). Moreover, the absolute inelastic nuclear interaction probability in the axial channeling orientation, along the ⟨ 110 ⟩ axis, was estimated for the first time, finding a value of 0.6 % for a crystal 2 mm long along the beam direction, with a bending angle of 55 µ rad. This value is more than two times lower with respect to the planar channeling orientation of the same crystal, and increases with the vertical angular misalignment. Finally, the correlation between the inelastic nuclear interaction probability in the planar channeling and the silicon crystal curvature is reported.

BDNF and LTP-/LTD-like plasticity of the primary motor cortex in Gilles de la Tourette syndrome.

Gilles de la Tourette syndrome (GTS) is characterized by motor and vocal tics and often associated with obsessive-compulsive disorder (OCD). Responses to intermittent/continuous theta-burst stimulation (iTBS/cTBS), which probe long-term potentiation (LTP)-/depression (LTD)-like plasticity in the primary motor cortex (M1), are reduced in GTS. ITBS-/cTBS-induced M1 plasticity can be affected by brain-derived neurotrophic factor (BDNF) polymorphism. We investigated whether the BDNF polymorphism influences iTBS-/cTBS-induced LTP-/LTD-like M1 plasticity in 50 GTS patients and in 50 age- and sex-matched healthy subjects. In GTS patients, motor and psychiatric (OCD) symptom severity was rated using the Yale Global Tic Severity Scale (YGTSS) and the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). We compared M1 iTBS-/cTBS-induced plasticity in healthy subjects and in patients with GTS. We also compared responses to TBS according to BDNF polymorphism (Val/Val vs Met carriers) in patients and controls. Fourteen healthy subjects and 13 GTS patients were Met carriers. When considering the whole group of controls, as expected, iTBS increased whereas cTBS decreased MEPs. Differently, iTBS/cTBS failed to induce LTP-/LTD-like plasticity in patients with GTS. When comparing responses to TBS according to BDNF polymorphism, in healthy subjects, Met carriers showed reduced MEP changes compared with Val/Val individuals. Conversely, in patients with GTS, responses to iTBS/cTBS were comparable in Val/Val individuals and Met carriers. YGTSS and Y-BOCS scores were comparable in Met carriers and in Val/Val subjects. We conclude that iTBS and cTBS failed to induce LTP-/LTD-like plasticity in patients with GTS, and this was not affected by BDNF genotype.

Parkinson Disease Genetics: A "Continuum" from Mendelian to Multifactorial Inheritance.

Parkinson Disease (PD) is a common neurodegenerative disorder of intricate etiology, caused by progressive loss of aminergic neurons and accumulation of Lewy bodies. The predominant role of genetics in the etiology of the disease has emerged since the identification of the first pathogenetic mutation in SNCA (alpha-synuclein) gene, back in 1997. Mendelian parkinsonisms, a minority among all PD forms, have been deeply investigated, with 19 loci identified. More recently, genome wide association studies have provided convincing evidence that variants in some of these genes, as well as in other genes, may confer an increased risk for late onset, sporadic PD. Moreover, the finding that heterozygous mutations in the GBA gene (mutated in Gaucher disease) are among the strongest genetic susceptibility factors for PD, has widened the scenario of PD genetic background to enclose a number of genes previously associated to distinct disorders, such as genes causative of spinocerebellar ataxias, mitochondrial disorders and fragile X syndrome. At present, the genetic basis of PD defines a continuum from purely mendelian forms (such as those caused by autosomal recessive genes) to multifactorial inheritance, resulting from the variable interplay of many distinct genetic variants and environmental factors.

Intravenous Levetiracetam as first-line treatment of status epilepticus in the elderly.

BACKGROUND: Status epilepticus is a condition of prolonged/repetitive seizures that often occurs in the elderly. Treatment in the elderly can be complicated by serious side effects associated with traditional drugs. OBJECTIVE: The aim of this pilot study was to evaluate the short-term efficacy/safety of intravenously administered LEV (IVLEV) as the treatment of choice for SE in the elderly. METHODS: We enrolled nine elderly patients (five female/four male; median age 78 years) with SE. Two patients had a previous diagnosis of epilepsy; in the remaining seven, SE was symptomatic. SE was convulsive in five and non-convulsive in four. All the patients presented concomitant medical conditions (arrhythmias/respiratory distress/hepatic diseases). As the traditional therapy for SE was considered unsafe, IVLEV was used as first-line therapy (loading dose of 1500 mg/100 ml/15 min, mean maintenance daily dose of 2500 mg/24 h) administered during video-EEG monitoring. RESULTS/CONCLUSIONS: In all the patients but one, IVLEV was effective in the treatment of SE and determined either the disappearance of (7/8), or significant reduction in (1/8), epileptic activity; no patient relapsed in the subsequent 24 h. No adverse events or changes in the ECG/laboratory parameters were observed. These data suggest that IVLEV may be an effective/safe treatment for SE in the elderly.

Chick gonadogenesis following early surgical bursectomy. II. Ultrastructural data on the embryonic left and right female gonads.

We examined the ultrastructural characteristics of the medullary steroidogenic cells in left and right female gonads of surgically bursectomized chick embryos killed on the 17th day of incubation. The steroidogenic cells of the bursectomized embryos have a more developed system of cisternae in the smooth endoplasmic reticulum than controls, and their mitochondria show some alterations in the density of the matrix and in the shape of the cristae. On the basis of these results, an enhancement of the steroidogenic activity in both gonads is suggested.

Chick gonadogenesis following early surgical bursectomy. I. Histological, morphometric and histochemical data on the embryonic left ovary.

Left ovaries of bursectomized chick embryos were examined on the 17th day of incubation in comparison to normal and sham-operated controls, by histological and histochemical observations. The results show that in bursectomized embryos the cortex appears irregularly developed, with a significant decrease in the mean thickness and in the percentage of the secondary sex cords in the total cortical area. Furthermore, the germinal epithelium appears thicker and the subcortical medulla and the tunica albuginea more compact. The greater activity of the enzyme delta 5-3 beta-hydroxysteroid dehydrogenase (delta (5)3 beta HSD) found in ovaries of bursectomized embryos (histochemical method) could be related to an endocrine dismetabolism affecting the cortical development. On the basis of these results and those of other authors, some hypotheses are advanced. In particular, an action of the bursal factor on GTH receptors could be the factor responsible of the enhanced steroidogenic activity altering the hormonal environment.

Influence of solvent, anion and presence of nitrogen in the ring structure on the mechanism of complexation of alkali metal cations with crown ethers.

The mechanism of complexation of alkali metal cations with macrocyclic ligands such as the simple crown ethers and the role of desolvation vs. ligand rearrangement are discussed. The unique role of water solvent in the rate-determining step of complexations in aqueous solutions is brought into focus. The competitive role of the anion, which becomes of paramount importance in solvents of low permittivity, is reiterated. Monoazo crown ethers are shown to possess isomeric equilibria in methanol solvent. The rate-determining process for the first step of complexation of these macrocycles with Na+ in methanol appears to be the rearrangement of the ligand through inversion to an exo position of the nitrogen lone electron pair. The rate-determining step of the overall complexation is the entrance of the Na+ into the ring with (possibly) concomitant rotation of the lone electron of the nitrogen to an endo configuration.