Xenogeneic Neu5Gc and self-glycan Neu5Ac epitopes are potential immune targets in MS.

OBJECTIVE To explore the repertoire of glycan-specific immunoglobulin G (IgG) antibodies in treatment-naive patients with relapsing-remitting multiple sclerosis (RRMS). METHODS A systems-level approach combined with glycan array technologies was used to determine specificities and binding reactivities of glycan-specific IgGs in treatment-naive patients with RRMS compared with patients with noninflammatory and other inflammatory neurologic diseases. RESULTS We identified a unique signature of glycan-binding IgG in MS with high reactivities to the dietary xenoglycan N-glycolylneuraminic acid (Neu5Gc) and the self-glycan N-acetylneuraminic acid (Neu5Ac). Increased reactivities of serum IgG toward Neu5Gc and Neu5Ac were additionally observed in an independent, treatment-naive cohort of patients with RRMS. CONCLUSION Patients with MS show increased IgG reactivities to structurally related xenogeneic and human neuraminic acids. The discovery of these glycan-specific epitopes as immune targets and potential biomarkers in MS merits further investigation

High resolution electron microscopy of a used automobile catalytic converter

This work is a study of a used automobile catalytic converter using mainly electron microscopy but also techniques such as x-ray powder diffraction, energy dispersive x-ray spectroscopy (EDS) and image simulation. The catalytic converter was used for ~ 80000 km in an ordinary car and partly with leaded fuel. The monolith could be identified as Mg2Al4Si5O18 (α- or β-cordierite). The lead contamination was detected all over the monolith but with a higher concentration in agglomerates on the cordierite surface. Small particles of elementary lead could be identified. The active metals (Pt and Rh) were mainly found as sintered particles (>10 nm) composed of both Pt and Rh. An unexpectedly high amount of Rh was found in these particles (Rh/Pt ratio ≥1). It was in some rare cases possible to image Pt or Rh particles with the initial size (~ 2 nm).Ce travail consiste en l'étude d'un pot d'échappement catalytique automobile par microscopie électronique principalement, et également par diffraction X sur poudres et microanalyse X par dispersion d'énergie. Ce pot d'échappement a été en service durant 80000 km sur une automobile courante dont une partie de la consommation était constituée d'essence au plomb. Le support a pu étre identifié comme Mg2Al4Si5O18 (Cordiérite α ou β). La contamination par le plomb a été detectée sur tout le support mais à plus forte concentration dans des agglomérats en surface de la cordiérite. Des petites particules de plombs ont été identifiées. Les métaux actifs (Pt et Rh) ont été principalement reconnus sous la forme de particules frittées (> 10 nm) composées de Pt et Rh. Une quantité importante, surprenante de Rh a été mise en évidence dans ces particules (Rh/Pt ≥ 1). Dans de rares cas, il a été possible de reconnaître des particules de Pt ou de Rh de taille initiale (≃ 2 nm)