Based on a selection of positive NPS collected in Switzerland during the 2010-2011 influenza season, this study suggests that the PLEX-ID/Flu assay is a convenient platform for the detection, typing, and subtyping (lineage characterization for influenza B) of circulating influenza viruses. The detection rate observed with the PLEX-ID platform, as well as the subtyping or lineage characterization of human influenza virus types A and B tends to suggest that it might play a role in the near future in most routine laboratories, but this needs to be confirmed in prospective and large comparative studies. In addition, the sensitivity of the PLEX-ID/Flu observed in this study could be increased if any positive PCR results were considered and if the typing result is not a requirement. However, this pilot study has intrinsic limitations mainly related to the fact that only realtime RT-PCR-positive specimens were selected initially. This precludes any appropriate evaluation of the respective sensitivity or specificity of the method. Compared to sequence analysis, the PLEX-ID/Flu assay has also limitations in terms of identification of specific mutations potentially involved in antiviral resistance, as well as drifted strains. Finally, the lack of accurate typing concerning the HA and NA genes is a major drawback and possibly limits the use of this assay as a first line diagnostic tests.  Evaluation of atherosclerotic lesions using dextran- and mannan–dextran-coated USPIO: MRI analysis and pathological findings Magnetic resonance imaging (MRI) can detect atherosclerotic lesions containing accumulations of ultrasmall superparamagnetic iron oxides (USPIO). Positing that improved USPIO with a higher affinity for atherosclerotic plaques would yield better plaque images, we performed MRI and histologic studies to compare the uptake of dextran- and mannan–dextran-coated USPIO (D-USPIO and DM-USPIO, respectively) by the atherosclerotic walls of rabbits. We intravenously injected atherosclerotic rabbits with DM-USPIO (n = 5) or D-USPIO (n = 5). Two rabbits were the controls. The doses delivered were 0.08 (dose 1) (n = 1), 0.4 (dose 2) (n = 1), or 0.8 (dose 3) (n = 3) mmol iron/Kg. The dose 3 rabbits underwent in vivo contrast-enhanced magnetic resonance angiography (MRA) before and 5 days after USPIO administration. Afterwards, all animals were euthanized, the aortae were removed and subjected to in vitro MRI study. The signal-to-noise ratio (SNR) of the aortic wall in the same region of interest (ROI) was calculated in both in vivo and in vitro studies. Histological assessment through measurement of iron-positive regions in Prussian blue-stained specimens showed that iron-positive regions were significantly larger in rabbits injected with DM- rather than D-USPIO (P < 0.05) for all doses. In vivo MRA showed that the SNR-reducing effect of DM- was greater than that of D-USPIO (P < 0.05). With in vitro MRI scans, SNR was significantly lower in rabbits treated with dose 2 of DM-USPIO compared with D-USPIO treatment (P < 0.05), and it tended to be lower at dose 3 (P < 0.1). In conclusion, we suggest that DM-USPIO is superior to D-USPIO for the study of atherosclerotic lesions in rabbits. Atherosclerosis is a chronic inflammatory response to vessel wall injury, leading potentially, to acute coronary syndrome and cerebral vascular disorders, induced by plaque rupture. The noninvasive imaging of atherosclerotic plaque progression and of therapeutic response is very important. In atherosclerosis, macrophage accumulation initiates lesion development and triggers clinical events by producing several molecules that promote inflammation, plaque disruption, and subsequent thrombus formation. [1] [2] [3] [4] However, conventional anatomic measurements of advanced lesions (eg, plaque size or luminal narrowing) do not necessarily correlate with macrophage content. It is desirable that imaging of macrophages permits the identification of highly activated plaques, to help in the prediction of acute thrombotic events, and to facilitate assessment of the therapeutic effects of antiatherosclerotic drugs, such as statins. In hyperlipidemic rabbits and humans, atherosclerotic plaques have been investigated using magnetic resonance imaging (MRI), using ultrasmall superparamagnetic iron oxides (USPIO): iron oxide nanoparticles stabilized with low-molecular-weight dextran, having a mean diameter of 30 nm. [5] [6] [7] [8] As these relatively small particles are not immediately recognized by the hepatic and splenic mononuclear phagocytic systems (MPS), 9, 10 the prolongation of their intravascular half-life permits their uptake, via macrophages, by the whole body, including the lymph nodes, lungs, and the walls of atherosclerotic vessels. [5] [6] [7] [8] 11, 12 With respect to the excretion pathway, USPIO particles are internalized by receptor-mediated endocytosis, and metabolized via the lysosomal pathway. 13 On internalization by macrophages, the dextran coating is progressively degraded; 89% is eliminated in urine, and the rest is excreted in feces. The iron contained in USPIO is incorporated into the body's iron store and used in hemoglobin manufacture. Like endogenous iron, it is eliminated very slowly, predominantly via the feces. 14 Based on USPIO-associated T2-and T2*shortening effects, atherosclerotic lesions with accumulated USPIO can be detected on MRI scans. Higher doses tended to be administered in earlier animal studies. We posited that improved USPIO with higher affinity for atherosclerotic plaques would make it possible to obtain better images of plaques at lower doses.