Fractal analysis of the structural complexity of the connective tissue in human carotid bodies

Abstract

The carotid body (CB) may undergo different structural changes during perinatal development, aging, or in response to environmental stimuli. In the previous literature, morphometric approaches to evaluate these changes have considered quantitative first order parameters, such as volumes or densities, while changes in spatial disposition and/or complexity of structural components have not yet been considered. In the present study, different strategies for addressing morphological complexity of CB, apart from the overall amount of each tissue component, were evaluated and compared. In particular, we considered the spatial distribution of connective tissue in the carotid bodies of young control subjects, young opiate-related deaths and aged subjects, through analysis of dispersion (Morisita's index), gray level co-occurrence matrix (entropy, angular second moment, variance, correlation), and fractal analysis (fractal dimension, lacunarity). Opiate-related deaths and aged subjects showed a comparable increase in connective tissue with respect to young controls. However, the Morisita's index (p < 0.05), angular second moment (p < 0.05), fractal dimension (p < 0.01), and lacunarity (p < 0.01) permitted to identify significant differences in the disposition of the connective tissue between these two series. A receiver operating characteristic (ROC) curve was also calculated to evaluate the efficiency of each parameter. The fractal dimension and lacunarity, with areas under the ROC curve of 0.9651 (excellent accuracy) and 0.8835 (good accuracy), respectively, showed the highest discriminatory power. They evidenced higher level of structural complexity in the carotid bodies of opiate-related deaths than old controls, due to more complex branching of intralobular connective tissue. Further analyses will have to consider the suitability of these approaches to address other morphological features of the CB, such as different cell populations, vascularization, and innervation.

Decellularized Human Skeletal Muscle as Biologic Scaffold for Reconstructive Surgery

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Microscopic anatomy of the visceral fasciae

“…Random images of 15 sections per sample, oriented parallel or perpendicular to the fascial plane, were analysed to measure the total thickness of each layer, the percentage of fascial elastic component (violet-stained with Weigert-van Gieson) and percentage of S100 and bIII-tubulin immunopositivity, with IMAGE J 1.6.0 software (National Institutes of Health, USA), freely available at http://rsb.inf o.nih.gov/ij/, and image analysis procedures previously described by our group (Porzionato et al 2005;Guidolin et al 2014).…”

A fractal analysis of the spatial distribution of tumoral mast cells in lymph nodes and bone marrow

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