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Milano, Italy

Millaku A.,Slovenian Institute of Metals And Technology | Leser V.,University of Ljubljana | Drobne D.,University of Ljubljana | Godec M.,Slovenian Institute of Metals And Technology | And 4 more authors.
Protoplasma | Year: 2010

The structure of the digestive gland epithelium of a terrestrial isopod Porcellio scaber has been investigated by conventional scanning electron microscopy (SEM), focused ion beam-scanning electron microscopy (FIB/SEM), and light microscopy in order to provide evidence on morphology of the gland epithelial surface in animals from a stock culture. We investigated the shape of cells, extrusion of lipid droplets, shape and distribution of microvilli, and the presence of bacteria on the cell surface. A total of 22 animals were investigated and we found some variability in the appearance of the gland epithelial surface. Seventeen of the animals had dome-shaped digestive gland "normal" epithelial cells, which were densely and homogeneously covered by microvilli and varying proportions of which extruded lipid droplets. On the surface of microvilli we routinely observed sparsely distributed bacteria of different shapes. Five of the 22 animals had "abnormal" epithelial cells with a significantly altered shape. In three of these animals, the cells were much smaller, partly or completely flat or sometimes pyramid-like. A thick layer of bacteria was detected on the microvillous border, and in places, the shape and size of microvilli were altered. In two animals, hypertrophic cells containing large vacuoles were observed indicating a characteristic intracellular infection. The potential of SEM in morphological investigations of epithelial surfaces is discussed. © Springer-Verlag 2010. Source

Ghigna P.,University of Pavia | Pin S.,University of Pavia | Spinolo G.,University of Pavia | Newton M.A.,European Synchrotron Radiation Facility | And 4 more authors.
Physical Chemistry Chemical Physics | Year: 2010

A specific preparation procedure makes possible to obtain in one shot structural and compositional characterization of a buried interface at the nanometre scale using a micrometre scale probe. A specific example based on dispersive μXAS, micro X-ray absorption spectroscopy, shows that nearly-atomic scale changes in local structure, composition, as well as local disorder are faithfully detected. The approach could in principle be applied to any probe with a micrometric resolution. Source

Leser V.,University of Ljubljana | Milani M.,University of Milan Bicocca | Tatti F.,FEI Italia | Tkalec Z.P.,University of Ljubljana | And 2 more authors.
Protoplasma | Year: 2010

The focused ion beam (FIB) and scanning electron microscope (SEM) are commonly used in material sciences for imaging and analysis of materials. Over the last decade, the combined FIB/SEM system has proven to be also applicable in the life sciences. We have examined the potential of the focused ion beam/scanning electron microscope system for the investigation of biological tissues of the model organism Porcellio scaber (Crustacea: Isopoda). Tissue from digestive glands was prepared as for conventional SEM or as for transmission electron microscopy (TEM). The samples were transferred into FIB/SEM for FIB milling and an imaging operation. FIB-milled regions were secondary electron imaged, back-scattered electron imaged, or energy dispersive X-ray (EDX) analyzed. Our results demonstrated that FIB/SEM enables simultaneous investigation of sample gross morphology, cell surface characteristics, and subsurface structures. The same FIB-exposed regions were analyzed by EDX to provide basic compositional data. When samples were prepared as for TEM, the information obtained with FIB/SEM is comparable, though at limited magnification, to that obtained from TEM. A combination of imaging, micro-manipulation, and compositional analysis appears of particular interest in the investigation of epithelial tissues, which are subjected to various endogenous and exogenous conditions affecting their structure and function. The FIB/SEM is a promising tool for an overall examination of epithelial tissue under normal, stressed, or pathological conditions. © 2010 Springer-Verlag. Source

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