High levels of cerebrospinal fluid IgM binding to myelin basic protein are associated with early benign course in multiple sclerosis

We assessed human myelin basic protein (MBP) binding IgM levels in CSF. MBP is the most studied putative antigen in multiple sclerosis (MS) and immune responses against it may be involved in the demyelination process. We also correlated these levels with EDSS score and other parameters of disease progression and prognosis, both at the time of CSF analysis and during follow-up. CSF IgM anti-MBP levels were assayed by measuring total IgM levels with solid-phase ELISA in CSF samples from 66 patients with relapsing-remitting MS, 11 subjects without neurological diseases, 20 patients with non-inflammatory neurological diseases and 7 patients with lymphocytic meningitis, before and after immunoabsorption with human MBP. Confirmation of IgM binding specificity was performed by immunoblotting of positive CSF samples onto MBP coated-nitrocellulose sheets. Clinical evaluation (disability score, number and time of attacks) was performed during a mean follow-up of 2.7 +/- 1.1 years. 23 of the 66 relapsing-remitting MS patients (33.8%) had elevated IgM anti-MBP levels. In this patient subgroup, IgM anti-MBP levels correlated with the IgM index (r = 0.71; P = 0.0001), but not with CSF/serum albumin (r = 0.08; P = 0.72). In the first year of follow-up, patients with low IgM anti-MBP suffered from more numerous attacks than those with elevated levels (0.86 +/- 0.63 versus 0.43 +/- 0.58; P = 0.017). Patients with high IgM binding to MBP had a first attack during follow-up in a significantly higher time than those with low binding (28.87 +/- 4.7 versus 17 +/- 2.6 months, respectively; P = 0.005) and reached a decrease of 0.5 EDSS point significantly faster than those with low IgM (16.17 +/- 1.2 versus 29.7 +/- 2.6 months, respectively; P = 0.0002). A similar significant finding was observed when the time to reach low disability score (EDSS < or = 2.0) was analyzed (10.7 +/- 2.57 +/- 3.3 months, respectively; P = 0.014). These findings demonstrate that in a subgroup of MS patients, elevated CSF levels of IgM anti-MBP are associated with early favorable course and therefore suggest that IgM binding to MBP could be a possible prognostic marker in relapsing-remitting MS to select early MS patients for future trials.     

Automatic evaluation of plastic collapse conditions for planar frames with vertical irregularities

Engineering with Computers - The plastic load and failure modes of vertically irregular planar frames are studied by means of an original software code developed in the agent-based programming...     

Focus on Extracellular Vesicles: Physiological Role and Signalling Properties of Extracellular Membrane Vesicles

Extracellular vesicles (EVs) are a heterogeneous population of secreted membrane vesicles, with distinct biogenesis routes, biophysical properties and different functions both in physiological conditions and in disease. The release of EVs is a widespread biological process, which is conserved across species. In recent years, numerous studies have demonstrated that several bioactive molecules are trafficked with(in) EVs, such as microRNAs, mRNAs, proteins and lipids. The understanding of their final impact on the biology of specific target cells remains matter of intense debate in the field. Also, EVs have attracted great interest as potential novel cell-free therapeutics. Here we describe the proposed physiological and pathological functions of EVs, with a particular focus on their molecular content. Also, we discuss the advances in the knowledge of the mechanisms regulating the secretion of EV-associated molecules and the specific pathways activated upon interaction with the target cell, highlighting the role of EVs in the context of the immune system and as mediators of the intercellular signalling in the brain.     

An improved ant colony optimization algorithm and its applications to limit analysis of frame structures

This article presents a modified ant colony systems approach, which allows reduction of the computational effort needed to converge to the optimal solution of a given engineering problem. The proposed algorithm is applied to the evaluation of the plastic load and failure modes of planar frames. The approach is based on the generation of elementary collapse mechanisms and on their linear combination, aimed at minimizing the collapse load factor. Many applications have been performed on frames of different sizes subjected to seismic load scenarios, i.e. permanent vertically distributed and variable concentrated forces at each floor. The values of the collapse load obtained with the proposed algorithm have been compared with those obtained by means of other optimization algorithms and nonlinear pushover analysis. An extended performance comparison between the proposed procedure and standard ant colony system algorithms shows the expected improvements in terms of a great reduction in the computational effort.     

Photophoretic force on particles for low Knudsen number

Calculations are presented for the photophoretic force on a spherical aerosol particle with size much larger than the mean free path of the surrounding gas molecules. Very good agreement is shown with recent experimental data. The results show that both components of the complex refractive index can be inferred from radiometric measurements.     

On profile reconstruction of Euler–Bernoulli beams by means of an energy based genetic algorithm

Engineering with Computers - This paper studies the inverse problem related to the identification of the flexural stiffness of an Euler Bernoulli beam to reconstruct its profile starting from...     

Nonlinear optical properties of CdS microspheres

The optical nonlinearity of a CdS microsphere is reported. It is shown that the observed effect can lead to a miniaturized, low power optical bistable device. The effect is due to the change in refractive index that accompanies the visible absorption near a morphological resonant mode.     

Short-term consolidation of individual identities leads to Lag-1 sparing.

A rapid serial visual presentation (RSVP) technique was used to investigate the role of the nature of processing carried out on targets in the Lag-1 sparing phenomenon. Lag-1 sparing refers to a higher accuracy in the task associated with the 2nd target when the 2 targets are immediately successive in the RSVP stream relative to when there are 1 or 2 intervening items between the targets. In 5 experiments, 0, 1, or 2 digits were embedded with equal probability in RSVP streams of letter distractors. In 4 of the experiments, subjects identified the digits in some blocks of trials, and they counted the number of presented digits in other blocks. In a 5th experiment, the counting task was replaced with a digit-sum task. The most interesting results were those from trials with 2 digits. Lag-1 sparing was always evident when the task involved the explicit identification of the digits. In addition, Lag-1 sparing was evident when subjects were required to sum 2 digits or to count digits of a prespecified parity subclass (e.g., count only even digits). In striking contrast, Lag-1 sparing was absent when subjects were required to count the digits independent of their parity subclass. These results suggest that the occurrence of Lag-1 sparing depends on the type of mental representation that must be generated on the basis of target information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reevaluating encoding-capacity limitations as a cause of the attentional blink.

A number of researchers have emphasized the role of distractors intervening between successive targets as the primary determinant of the attentional blink (AB) phenomenon. They argued that the AB is abolished when 3 or more targets are displayed as temporally contiguous items in rapidly presented serial sequences. In 3 experiments, the authors embedded 1-, 2-, or 3-digit targets among letter distractors in rapidly presented visual sequences. Across the experiments, both the number of targets and the lag between them were manipulated, producing different proportion of trials in which 3 temporally contiguous targets were presented in the test session. Evidence of an AB affecting the targets that followed the first target in these sequences was found in each experiment when the probability of a given target report was conditionalized on a correct response to the preceding targets, thus reinforcing the notion that some form of capacity limitation in the encoding of targets plays a central role in the elicitation and modulation of the AB effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)