There has been significant recent interest in the development of technologies for enumeration of rare circulating cells directly in the bloodstream in many areas of research, for example, in small animal models of circulating tumor cell dissemination during cancer metastasis. We describe a fiber-based optical probe that allows fluorescence detection of labeled circulating cells in vivo in a diffuse reflectance configuration. We validated this probe in a tissue-mimicking flow phantom model in vitro and in nude mice injected with fluorescently labeled multiple myeloma cells in vivo. Compared to our previous work, this design yields an improvement in detection signal-to-noise ratio of 10 dB, virtually eliminates problematic motion artifacts due to mouse breathing, and potentially allows operation in larger animals and limbs.
Published in 2001, the Common European Framework of Reference for Languages (CEFR), a reference framework which informs teaching, learning and assessment in language education, appears to be increasingly recognized, referenced and utilized in language education contexts worldwide. To date however, the extent, provenance and adoption of the collected body of knowledge concerning the CEFR has yet to be systematically analysed, rendering it difficult for any conclusions to be made about its impact. A bibliometric analysis was therefore conducted to explore the CEFR from the document’s more formal origins in 1990 to the end of 2017 for the bibliometric indicators of number of publications per year, geographical location of research, highly cited works and journals with the highest number of relevant publications. The findings show that research on the CEFR has increased significantly over the examined time. The majority of publications with a focus on the CEFR are European, but numbers are increasing in geographical areas outside of Europe, and particularly in Asia. The framework is discussed in numerous types of publications covering a range of topics in language education. These findings suggest that the CEFR has been used in contexts beyond its origins and has influenced many aspects of language education around the globe. Diffusion of innovations theory suggests that the CEFR’s impact and influence is likely to increase over the next ten years in and outside of Europe and especially in Asia.
11103 Background: Multiple myeloma (MM) is characterized by the disseminated involvement of the bone-marrow (BM), and its progression involves a continuous circulation of the MM cells (MMCs) in the peripheral blood and homing back to the BM. Selectins are adhesion molecules involved in the primary interaction of lymphocytes with the endothelial cells (ECs) of blood vessels. In this study we studied the role selectins in the pathogenesis of MM. Methods: We have characterized the expression of E, L and P-selectins and their ligands on MM cell lines, patient sample and plasma cells from normal subjects (NPCs). We have tested the effect of blockade of each of the selectins and selectin-ligands on the interaction of MMCs with ECs. Moreover, we tested the effect of a pan selectin inhibitor on MMCs adhesion to ECs, and trans-well (through filter) and trans-endothelial SDF1-induced migration in vitro, and characterized its effect on cytoskeletal signaling induced by the interaction of MMCs and ECs. Moreover, we have tested the effect of the inhibitor on homing of MMCs to the BM in mice using in vivo flow cytometry to detect the number of circulating cells, and in vivo confocal microscopy to directly visualize the homing. Results: All MM cell lines and patient samples had low expression of all selectins and high expression of L and P, but not E, selectin ligands. While NPCs showed low expression of all selectins and ligands. Blockade of L and P-selectin ligands reduced the interaction of MMCs with ECs in vitro, while blockade of E-selectin ligand or any of selectins did not show any effect. The pan-selectin inhibitor reduced the interaction of MMCs with ECs in vitro, did not alter their SDF1-induced migration through filter, but reduced significantly the migration through ECs. The inhibitor inhibited the activation of FAK and ERK induced by interaction of MMCs and ECs. Moreover, the selectin inhibitor extending the circulation time of MM cells in mice, and reduced the homing of MMCs. Conclusions: We found that L and P selectin ligands are highly expressed in MMCs compared to NPCs, and that those play a major role in homing of MMCs to the BM. Moreover, the pan-selectin inhibitor prevented the homing of MMCs to the BM. This provides a basis for testing the effect of the inhibitor on MM tumor progression and initiation. No significant financial relationships to disclose.
Detection and enumeration of rare circulating cells in mice are important problems in many areas of preclinical biomedical research. Recently, we developed a new method termed “diffuse fluorescence flow cytometry” (DFFC) that uses diffuse photons to increase the blood sampling volume and sensitivity versus existing in vivo flow cytometry methods. In this work, we describe a new DFFC prototype with approximately an order-of-magnitude improvement in sensitivity compared to our previous work. This sensitivity improvement is enabled by a number of technical innovations, which include a method for the removal of motion artifacts (allowing interrogation of mouse hindlegs that was less optically attenuating versus the tail) and improved collection optics and signal preamplification. We validated our system first in limb mimicking optical flow phantoms with fluorescent microspheres and then in nude mice with fluorescently labeled mesenchymal stem cells at injected concentrations of 5×10 3 cells/mL . In combination, these improvements resulted in an overall cell counting sensitivity of about 1 cell/mL or better in vivo.
