33 research outputs found
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Correlative light and electron microscopy using cathodoluminescence from nanoparticles with distinguishable colours
Correlative light and electron microscopy promises to combine molecular specificity with nanoscale imaging resolution. However, there are substantial technical challenges including reliable co-registration of optical and electron images, and rapid optical signal degradation under electron beam irradiation. Here, we introduce a new approach to solve these problems: imaging of stable optical cathodoluminescence emitted in a scanning electron microscope by nanoparticles with controllable surface chemistry. We demonstrate well-correlated cathodoluminescence and secondary electron images using three species of semiconductor nanoparticles that contain defects providing stable, spectrally-distinguishable cathodoluminescence. We also demonstrate reliable surface functionalization of the particles. The results pave the way for the use of such nanoparticles for targeted labeling of surfaces to provide nanoscale mapping of molecular composition, indicated by cathodoluminescence colour, simultaneously acquired with structural electron images in a single instrument.Physic
Characteristics of multiple sclerosis patient stance control disorders, measured by means of posturography and related to brainstem lesions
Balance disorders are commonly observed during the course of multiple sclerosis (MS). The aim of this study is to report characteristics of MS patient stance control disorders, measured by means of posturography and related to the brainstem lesions. Thirty-eight patients affected by MS, mildly to moderately disable according to Kurtzke\u2019s Expanded Disability Status Scale, underwent a complete clinical neurological and vestibular evaluation and brain MRI scanning. All patients were then tested on a static posturography platform (Tetrax, Israel) in four conditions: eyes open and eyes closed standing on a firm surface and on a foam pad. Clinical and/or magnetic resonance imaging evidence of brainstem involvement was observed in 55.3% of patients. When brainstem lesion was detected, Fourier analysis showed a typical pattern characterized by inversion of the 0- 0.1 Hz and 0.1-0.25 Hz frequency bands. In conclusion, MS leads to pervasive postural disturbances in the majority of subjects, including the visuo-vestibular loops and proprioception involving vestibulospinal pathways in at least 55.3% of patients. Our results may also suggest the presence of Fourier inversion in patients with brainstem lesions
Molecular mechanisms of glucocorticoids action: implications for treatment of rhinosinusitis and nasal polyposis
Intra-nasal glucocorticoids are the most effective drugs available for rhinosinusitis and nasal polyposis treatment. Their effectiveness depends on many factors and not all of them have been well recognized so far. The authors present the basic information on molecular mechanisms of glucocorticoid action, direct and indirect effects of glucocorticoids on transcription of genes encoding inflammatory mediators. They focus on recently proved nongenomic mechanisms which appear quickly, from several seconds to minutes after glucocorticoid administration and discuss clinical implications resulting from this knowledge. Discovery of nongenomic glucocorticoid actions allows for better use of these drugs in clinical practice
The relationship of C-reactive protein levels and positive culture with quality of life in acute rhinosinusitis
Petr Schalek, Zuzana Hornáčková, Aleš Hahn Ear, Nose and Throat department, 3rd Medical Faculty of Charles University, Prague, Czech Republic Background: Acute rhinosinusitis (ARS) has been shown to significantly reduce patient quality of life (QoL). While the QoL in patients with chronic rhinosinusitis has been the subject of intensive research over the last decade, studies measuring the impact of ARS on patient QoL have remained relatively scarce. The aim of this study was to determine the relationship between the QoL and parameters suggestive of acute bacterial rhinosinusitis (C-reactive protein [CRP] levels and positive culture) and to see if measurement of the QoL could be used as an indicator for antibiotic treatment in ARS.Methods: Eighty patients with ARS were enrolled in the study. A novel QoL instrument for patients with ARS, called Measurement of Acute Rhinosinusitis (MARS) questionnaire, was given to patients at the time of diagnosis. We assessed patient QoL, obtained endoscopically guided cultures from the middle meatus, and measured levels of CRP. The relationship between QoL MARS scores (QoL-Mscores) and CRP was determined using a correlation coefficient. To compare QoL-Mscores, relative to culture-positive and culture-negative patients, the Student’s t-test was used.Results: No correlation between the QoL, assessed using the MARS questionnaire, and positive middle meatus culture was demonstrated (P=0.332). A weak correlation was found between QoL-Mscores and CRP values, with a correlation coefficient of 0.221 and P=0.0498.Conclusion: No correlation between the QoL in ARS patients and positive culture was found in this study. The clinical significance of the correlation between QoL-Mscores and CRP values in the antibiotic decision making process needs further research. Keywords: endoscopy, quality of life, questionnaires, anti-bacterial agent