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The properties and structure of the cellular microenvironment can influence cell behavior. Sites of cell adhesion to the extracellular matrix (ECM) initiate intracellular signaling that directs cell functions such as proliferation, differentiation, and apoptosis. Electrospun fibers mimic the fibrous nature of native ECM proteins and cell culture in fibers affects cell shape and dimensionality, which can drive specific functions, such as the osteogenic differentiation of primary human bone marrow stromal cells (hBMSCs), by. In order to probe how scaffolds affect cell shape and behavior, cell‐fiber contacts were imaged to assess their shape and dimensionality through a novel approach. Fluorescent polymeric fiber scaffolds were made so that they could be imaged by confocal fluorescence microscopy. Fluorescent polymer films were made as a planar control. hBSMCs were cultured on the fluorescent substrates and the cells and substrates were imaged. Two different image analysis approaches, one having geometrical assumptions and the other having statistical assumptions, were used to analyze the 3D structure of cell‐scaffold contacts. The cells cultured in scaffolds contacted the fibers in multiple planes over the surface of the cell, while the cells cultured on films had contacts confined to the bottom surface of the cell. Shape metric analysis indicated that cell‐fiber contacts had greater dimensionality and greater 3D character than the cell‐film contacts. These results suggest that cell adhesion site‐initiated signaling could emanate from multiple planes over the cell surface during culture in fibers, as opposed to emanating only from the cell's basal surface during culture on planar surfaces. [ABSTRACT FROM AUTHOR]

The microflora of avian gastrointestinal tract has received increased attention as the focus of efforts to improve animal nutrition and to minimize food-borne illness in humans. This microflora is subjected to variations according to diet, environment and treatments. Conventional methods for determining the flora composition rely on the cultivation of bacteria on anaerobic selective media. This approach is time-consuming because many bacteria are difficult to culture or are uncultivable. Molecular tools introduced in microbial ecology have made it possible to study the composition of intestinal flora in a culture-independent way. Our paper describes a methodological aspects and application of FISH method with rRNA-targeted fluorescent probes to identify bacteria from the gastrointestinal tract of turkey. This technique poses advantages compared with traditional culture-based methods as it does not require cultivation of the target organisms. FISH enables to address simultaneously various ecological issues: 1. to by-pass cultivation problems, 2. to identify and to accurately enumerate prokaryote sub-populations in natural systems by using sets of probes 3. to analyze their spatial distributions. Although FISH has been used widely in bacterial ecology, the method requires some adaptation to the type of samples analyzed. Applying the optimized FISH method for the analysis of turkey caecum, we were able to identify Eubacterium rectale, the genera Enterobacteriaceae, Bacteroides, Bifidobacterium, and Lactobacillus-Enterococcus groups. [ABSTRACT FROM AUTHOR]