A modified NaOH maceration method for removing extracellular ground substance was applied to scanning electron microscopic (SEM) studies of the mammalian aorta and elastic cartilage. Fixed tissues were freeze-fractured in liquid nitrogen and then immersed in 2N NaOH solution for 4-6 hr at room temperature. Since this method selectively digested proteoglycans, cellular and fibrous elements were observable clearly under the SEM. The elastic laminae of smooth muscle cells of the aortic tunica media were concealed by fine collagen fibrils, while chondrocytes in the elastic cartilage were encapsulated by a dense network of fine collagen fibrils and branching elastin fibers.
"They were deparaffinized with xylene, hydrated , and fixed again in a mixture of 2.5% glutaraldehyde and 2% paraformaldehyde (Karnovsky's fixative). After specimens were immersed in 2N NaOH at 37 C for 3 hr to digest proteoglycans , they were washed thoroughly in distilled water and placed in cacodylate-buffered 1% osmium tetroxide, 1% tanic acid solution and 1% osmium tetroxide for 1h each. They were then dehydrated through a graded series of ethanol, dried by the tbutanol drying method, coated with gold and observed using a scanning electron microscope (Hitachi S-800, Japan). "
[Show abstract][Hide abstract] ABSTRACT: The posterior aspect of heel is known as a particularly vulnerable site for pressure ulcer development, however, it is not well understood why this is so. This study was undertaken to identify the morphological characteristics of the skin over posterior aspect of heel in the context of pressure ulcer development. Human skin tissues were obtained from four different sites of the body of 4 aged subjects postmortem: posterior aspect of heel, plantar aspect of heel, sacrum and centre of gluteus maximus. The skin samples were processed for the examination using light microscopy and scanning electron microscopy. The posterior aspect of heel was characterized by a thicker epidermis, denser distribution and larger diameter of capillaries in the papillary layer, 3-dimensional architecture of collagen fibre meshwork in the reticular layer and elliptic adipose tissues situated perpendicularly to the skin surface being surrounded by thick collagen and elastic fibre septa compared to the sacrum. Given our observations in the papillary layer of the posterior aspect of heel, we assume that the tissue of this area may be less tolerant to ischaemia since the tissue has high metabolic demand to provide oxygen and nutrients to the epidermis which protects underlying tissue from external force. In addition, elliptic configuration of adipose tissues in the posterior aspect of heel situated perpendicularly to the skin surface may result in deep lesion if the forces applied exceed the tolerable level since the forces will be concentrated within the elliptic compartments.
"Although there is variation between findings and it might be because different arteries were analyzed, most studies proved that the fiber orientation differs between media and adventitia  . Further studies indicated a variation in fiber orientation in the inner media region, which is assumed to be due to the transmission of shear stress from the flowing blood into the inner layers of the media  . These architectures were observed using different methods, such as polarized light microscopy , X-ray diffraction  and nonlinear optical microscopy (NLOM)  . "
[Show abstract][Hide abstract] ABSTRACT: Collagen is the main load-bearing component of the artery. The 3D arrangement of the collagen fibers is crucial to understand the mechanical behavior of such tissues. We compared collagen fiber alignment obtained by second harmonic generation (SHG) microscopy with the alignment obtained by diffusion tensor imaging (DTI) throughout the wall of a porcine carotid artery to check the feasibility of using DTI as a fast and non-destructive method instead of SHG. The middle part of the artery was cut into two segments: one for DTI and one for the SHG measurements. The tissue for SHG measurements was cut into 30μm tangential sections. After scanning all sections, they were registered together and the fiber orientation was quantified by an in-house algorithm. The tissue for DTI measurement was embedded in type VII agarose and scanned with an MRI-scanner. Fiber tractography was performed on the DTI images. Both methods showed a layered structure of the wall. The fibers were mainly oriented circumferentially in the outer adventitia and media. DTI revealed the predominant layers of the arterial wall. This study showed the feasibility of using DTI for evaluating the collagen orientation in native artery as a fast and non-destructive method.
Biochemical and Biophysical Research Communications 08/2012; 426(1):54-8. DOI:10.1016/j.bbrc.2012.08.031 · 2.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The three-dimensional configurations of the proprial papillae in the human esophagus were observed by light microscopy, routine transmission electron microscopy, and scanning electron microscopy combined with NaOH maceration. Numerous finger-like or filiform papillae with a height of about 100m and a width at the base of approximately 30m were clearly distributed in the uppermost proprial layer at approximately equal intervals. The adepithelial surface of the proprial papillae was bordered by a reticular fiber sheet that was stained a deep black color by silver staining. The papillae possessed blood capillaries with fenestration, nerve fibers, and free cells such as lymphocytes, eosinophils, mast cells, and Langerhans-like cells. These findings clearly demonstrate characteristic three-dimensional features of proprial papillae, and their constituent cellular and structural elements in human esophagus.
Medical Electron Microscopy 01/1997; 30(1):15-24. DOI:10.1007/BF01458347
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