Additivity of the mechanical properties of Al-Sn pseudoalloys

The influence of deformation on the mechanical properties of sintered Al-Sn composites was investigated. It was found that under compression test the strength of investigated materials is an additive value and determined by the rule of mixture. After processing by ECAP the strength of sintered Al-Sn composites increases by more than 2 times but remains additive value. During ECAP, the strengthening of the composites is caused by grinding of the grain structure of the aluminum matrix

Comparative effectiveness of levetiracetam, valproate and carbamazepine among elderly patients with newly diagnosed epilepsy: subgroup analysis of the randomized, unblinded KOMET study

BACKGROUND: Few clinical trials have evaluated the efficacy and tolerability of antiepileptic drugs (AEDs) as initial monotherapy for elderly patients. METHODS: This post-hoc subgroup analysis of data from an unblinded, randomized, 52-week superiority study (KOMET) compared the effectiveness of levetiracetam (LEV) with extended-release sodium valproate (VPA-ER) and controlled-release carbamazepine (CBZ-CR) as monotherapy in patients aged 60 years with newly diagnosed epilepsy. The physician chose VPA or CBZ as preferred standard treatment; patients were randomized to standard AEDs or LEV. The primary endpoint was time to treatment withdrawal. Results are exploratory, since KOMET was not powered for a subgroup analysis by age. RESULTS: Patients (n = 308) were randomized to LEV (n = 48) or VPA-ER (n = 53) in the VPE-ER stratum or to LEV (n = 104) or CBZ-CR (n = 103) in the CBZ-CR stratum. Mean age was 69.6 years, range 60.2-89.9 years (intention-to-treat population n = 307). Time to treatment withdrawal hazard ratio [HR] (95 % confidence interval [CI]) for LEV vs. standard AEDs was 0.44 (0.28-0.67); LEV vs. VPA-ER: 0.46 (0.16-1.33); LEV vs. CBZ-CR: 0.45 (0.28-0.72). Twelve-month withdrawal rates were: LEV vs. standard AEDs, 20.4 vs. 38.7 %; LEV vs. VPA-ER, 10.4 vs. 23.1 %; LEV vs. CBZ-CR, 25.0 vs. 46.6 %. Time to first seizure was similar between LEV and standard AEDs (HR: 0.92, 95 % CI: 0.63-1.35), LEV and VPA-ER (0.77, 0.38-1.56), and LEV and CBZ-CR (1.02, 0.64-1.63). Adverse events were reported by 76.2, 67.3, and 82.5 % of patients for LEV, VPA-ER, and CBZ-CR, respectively. Discontinuation rates due to AEs were 11.3, 10.2, and 35.0 % for LEV, VPA-ER, and CBZ-CR, respectively.CONCLUSIONS: Time to treatment withdrawal was longer with LEV compared with standard AEDs. This finding was driven primarly by the result in the CBZ-CR stratum, which in turn was likely due to the more favorable tolerability profile of LEV. Results of this post-hoc analysis suggest that LEV(VLID)195291

Cortical excitability changes induced by deafferentation of the contralateral hemisphere

Short‐term deprivation of sensory input by ischaemic nerve block (INB) leads to functional reorganization in the deafferented motor cortex. Here, we show that INB also elicits functional changes in homotopic regions of the cortex contralateral to the deafferented one. We measured motor evoked potential (MEP) amplitudes elicited by transcranial magnetic stimulation (TMS) in small hand and biceps brachii muscles before, during and after INB of the right hand. INB increased excitability of the cortical representation of (i) the intact hand and (ii) body parts proximal to the deafferented hand (upper arm), in the absence of excitability changes in other body part representations such as thorax or leg muscles. This effect persisted throughout the entire period of deafferentation and returned to baseline values afterward. Motor responses to brainstem electrical stimulation remained unchanged during INB, indicating that the effect is probably of cortical origin. Lorazepam, a GABAA receptor agonist, blocked this increased excitability. Interhemispheric inhibition between hand muscles decreased during INB. After chronic deafferentation in amputees, MEP amplitudes and motor output curves in small hand muscles were depressed and motor thresholds were elevated compared with aged‐matched controls. These results indicate that acute hand deafferentation can elicit a focal increase in excitability in the hand motor representation contralateral to the deafferented cortex that is influenced by transcallosal interactions and GABAergic transmission, and is balanced in the setting of chronic deafferentatio

Reduced D2/D3 Receptor Binding of Extrastriatal and Striatal Regions in Temporal Lobe Epilepsy

<div><p>Objective</p><p>Dopamine is an endogenous neuromodulator in cortical circuits and the basal ganglia. In animal models of temporal lobe epilepsy (TLE), seizure threshold is modulated to some extent by dopamine, with D1-receptors having a pro- and D2-receptors an anticonvulsant effect. We aimed to extend our previously reported results on decreased D2/D3 receptor binding in the lateral epileptogenic temporal lobe and to correlate them with demographic and seizure variables to gain a more comprehensive understanding of the underlying involvement of the dopaminergic system in the epileptogenesis of TLE.</p><p>Methods</p><p>To quantify D2/D3 receptor binding, we studied 21 patients with TLE and hippocampal sclerosis (13 left- and eight right-sided) and 18 controls using PET with the high-affinity dopamine D2/D3-receptor ligand ¹⁸F-Fallypride to image striatal and extrastriatal binding. TLE was defined by interictal and ictal video-EEG, MRI and ¹⁸F-Fluorodeoxyglucose PET. Voxel-based statistical and regions-of-interest analyses were performed.</p><p>Results</p><p>¹⁸F-Fallypride binding potential was significantly reduced in the affected temporal lobe and bilateral putamen. A positive correlation between age at onset of epilepsy and [¹⁸F]FP BP_nd (binding potential non-displaceable) in temporal regions on the epileptogenic side was found, as well as a negative correlation between epilepsy duration and [¹⁸F]FP BP_nd in the temporal pole on the epileptogenic side and a positive correlation between the estimated number of lifetime GTCS and [¹⁸F]FP BP_nd in the hippocampus on the epileptogenic side.</p><p>Significance</p><p>The areas of reduced D2/D3 receptor availability correspond to “the irritative zone” surrounding the epileptogenic area. Moreover, reduced D2/D3 receptor availability was detectable in the basal ganglia, which are suspected to be involved in a control circuit for epileptic seizures. The correlational analysis additionally suggests that increased epilepsy duration leads to increasing impairment of the dopaminergic system.</p></div

Early Diagnosis of Acanthamoeba Infection during Routine Cytological Examination of Cerebrospinal Fluid

Early identification of Acanthamoeba in cerebrospinal fluid is mandatory to prevent fatal granulomatous amebic encephalitis. In the case presented here amebic trophozoites were detected in a routine cerebrospinal fluid sample. The antibiotic treatment and the apparently low virulence of this isolate were responsible for the benign progression of the infection