Exploring the utility of fibreoptic endoscopic evaluation of swallowing in young children- A comparison with videofluoroscopy.

OBJECTIVES/HYPOTHESIS: In adults, fibreoptic endoscopic evaluation of swallowing (FEES) has established its place in the assessment of dysphagia and aspiration vis-à-vis the current gold standard, videofluoroscopic swallow study (VFSS), almost at parity. However, in children with quite a different set of factors in play, its role is not certain. The primary objective was to measure the accuracy of FEES in young children with dysphagia, compared to VFSS. The secondary objective was to correlate other endoscopic findings with aspiration in videofluoroscopy. STUDY DESIGN: Prospective, observational. METHODOLOGY: Sixty-five children, aged 0.4-36 months with suspected oropharyngeal dysphagia and aspiration underwent FEES and VFSS. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy and diagnostic agreement of FEES were calculated using VFSS as the gold standard. To test the statistical significance of the difference in two measurements, Mc Nemar's Chi-square test was used and to test the agreement between FEES and VFSS, Kappa value was calculated. To test the statistical significance of the association of endoscopic findings with VFSS findings, Chi-square test was used. RESULTS: FEES performed in young children was found to be less sensitive (50%) but more specific of aspiration (82%) with an accuracy of 77% in comparison with VFSS. The reverse was true of penetration (81%, 44% and 59% respectively). The agreement between FEES and VFSS in young children, on all parameters were low (k = 0.061-0.302). Endoscopic findings such as glottic secretions (P = 0.02), weak or diminished laryngeal adductor reflex (LAR) (P = 0.001) and penetration (P = 0.01) were significantly associated with aspiration in VFSS. Excessive secretions in the hypopharynx had a stronger correlation with oesophageal dysmotility (P = 0.02) than pharyngeal dysphagia (P = 0.05). CONCLUSION: FEES in young children appears to have a low agreement with VFSS unlike in adults. Aspiration observed in FEES is likely to be significant since specificity is high. FEES negative for aspiration may be interpreted taking into account, the aspiration risk of the subject and/or other endoscopic risk factors (penetration, weak/absent LAR & glottic secretions), if VFSS is not a viable alternative.

Vibration spectroscopy and body biofluids: Literature review for clinical applications.

Vibrational spectroscopy techniques such as Raman and IR (infrared) allow real-time, non-invasive and non-destructive analysis of organic compounds with a good limit-of-detection. This review aims to show the progress of clinical diagnosis and prognosis due to advances of vibrational spectroscopy techniques in biofluids through an extensive literature review. This review was performed by searching for studies using the keywords "biofluids or biological fluids" and "diagnostic techniques" in PubMed, Scopus and Google Scholar. We found 580 articles in the 1990s, 1171 articles in the 2000s and 1688 in the years from 2011. Also, a second search including "biofluids or biological fluids" and "vibrational spectroscopy" returned only one article in the 1990s, three papers in the 2000s and 18 in the years from 2011.This growth suggests a great potential of biofluid research using vibrational spectroscopy. Sample collection variations(quantity and contaminations due to contact with other body parts and their secretions) are important factors that influence sample composition. Once these factors are taken into account, spectroscopic analysis may provide the necessary information to identify a disease, lesion, tumor or infection. With the present review we aim to encourage the study of vibrational spectroscopy techniques for analysis of biofluids focusing in clinical applications. In the future, it will widely benefit clinicians, allowing new diagnostic approaches, and for patients to have early diagnosis for most every disease.

Mechanisms of temporary adhesion in benthic animals.

Adhesive systems are ubiquitous in benthic animals and play a key role in diverse functions such as locomotion, food capture, mating, burrow building, and defence. For benthic animals that release adhesives, surface and material properties and external morphology have received little attention compared to the biochemical content of the adhesives. We address temporary adhesion of benthic animals from the following three structural levels: (a) the biochemical content of the adhesive secretions, (b) the micro- and mesoscopic surface geometry and material properties of the adhesive organs, and (c) the macroscopic external morphology of the adhesive organs. We show that temporary adhesion of benthic animals is affected by three structural levels: the adhesive secretions provide binding to the substratum at a molecular scale, whereas surface geometry and external morphology increase the contact area with the irregular and unpredictable profile of the substratum from micro- to macroscales. The biochemical content of the adhesive secretions differs between abiotic and biotic substrata. The biochemistry of the adhesives suitable for biotic substrata differentiates further according to whether adhesion must be activated quickly (e.g. as a defensive mechanism) or more slowly (e.g. during adhesion of parasites). De-adhesion is controlled by additional secretions, enzymes, or mechanically. Due to deformability, the adhesive organs achieve intimate contact by adapting their surface profile to the roughness of the substratum. Surface projections, namely cilia, cuticular villi, papillae, and papulae increase the contact area or penetrate through the secreted adhesive to provide direct contact with the substratum. We expect that the same three structural levels investigated here will also affect the performance of artificial adhesive systems.