Multilayer Microstructure of Idiopathic Epiretinal Macular Membranes

2017 ◽  
Vol 27 (6) ◽  
pp. 762-768 ◽  
Author(s):  
Claudio Azzolini ◽  
Terenzio Congiu ◽  
Simone Donati ◽  
Alberto Passi ◽  
Petra Basso ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Soft Tissue ◽  
Fibrous Material ◽  
Collagen Fibrils ◽  
Thin Sheets ◽  
Inner Limiting Membrane ◽  
3D Architecture ◽  
Fine Resolution ◽  
Scanning Electron

Purpose To identify the ultramicroscopic structure of idiopathic epiretinal macular membranes (iEMMs) by scanning electron microscopy (SEM). Methods We examined 28 iEMMs surgically removed from 28 eyes of 28 patients. All specimens, previously observed at stereomicroscope, were treated with an osmium maceration technique. Fine resolution of iEMMs’ 3D architecture and their interaction with the retina were studied using a Philips SEM-FEG XL-30 microscope. Results The specimens appeared as laminar connective structures partially or completely adherent to the inner limiting membrane (ILM). We identified 4 types of structures: ( 1 ) distinct layers of thin sheets of woven fibers; ( 2 ) folded layers of inhomogeneous thickness of fibrous material more consistent; ( 3 ) thicker and more rigid layers recognizable as collagen fibrils with typical 64-nm period, collagen fibrils isolated or intermingled between them; ( 4 ) lacunar structures with inflammatory and/or necrotic material. The first 3 types of structures appear to thicken towards a centripetal direction from the ILM to the vitreous in order from 1 to 3. The interface of ILM-iEMM tissue shows particular small bridges of connection. Cells are rarely found, especially in the tissue near the ILM. Conclusions Layers of various materials follow one another in iEMMs. Cells are rarely found. The interface ILM-iEMM tissue shows particular small bridges of connection. The dynamic modeling of bended layers begins in soft tissue.

scholarly journals What Is Considered a Variation of Biomechanical Parameters in Tensile Tests of Collagen-Rich Human Soft Tissues?—Critical Considerations Using the Human Cranial Dura Mater as a Representative Morpho-Mechanic Model

Medicina ◽  
2020 ◽  
Vol 56 (10) ◽  
pp. 520
Author(s):  
Johann Zwirner ◽  
Mario Scholze ◽  
Benjamin Ondruschka ◽  
Niels Hammer
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Soft Tissue ◽  
Dura Mater ◽  
Soft Tissues ◽  
Tensile Tests ◽  
Interquartile Range ◽  
Tissue Structure ◽  
Mechanical Parameters ◽  
Scanning Electron

Background and Objectives: Profound knowledge on the load-dependent behavior of human soft tissues is required for the development of suitable replacements as well as for realistic computer simulations. Regarding the former, e.g., the anisotropy of a particular biological tissue has to be represented with site- and direction-dependent particular mechanical values. Contrary to this concept of consistent mechanical properties of a defined soft tissue, mechanical parameters of soft tissues scatter considerably when being determined in tensile tests. In spite of numerous measures taken to standardize the mechanical testing of soft tissues, several setup- and tissue-related factors remain to influence the mechanical parameters of human soft tissues to a yet unknown extent. It is to date unclear if measurement extremes should be considered a variation or whether these data have to be deemed incorrect measurement outliers. This given study aimed to determine mechanical parameters of the human cranial dura mater as a model for human soft tissues using a highly standardized protocol and based on this, critically evaluate the definition for the term mechanical “variation” of human soft tissue. Materials and Methods: A total of 124 human dura mater samples with an age range of 3 weeks to 94 years were uniformly retrieved, osmotically adapted and mechanically tested using customized 3D-printed equipment in a quasi-static tensile testing setup. Scanning electron microscopy of 14 samples was conducted to relate the mechanical parameters to morphological features of the dura mater. Results: The here obtained mechanical parameters were scattered (elastic modulus = 46.06 MPa, interquartile range = 33.78 MPa; ultimate tensile strength = 5.56 MPa, interquartile range = 4.09 MPa; strain at maximum force = 16.58%, interquartile range = 4.81%). Scanning electron microscopy revealed a multi-layered nature of the dura mater with varying fiber directions between its outer and inner surface. Conclusions: It is concluded that mechanical parameters of soft tissues such as human dura mater are highly variable even if a highly standardized testing setup is involved. The tissue structure and composition appeared to be the main contributor to the scatter of the mechanical parameters. In consequence, mechanical variation of soft tissues can be defined as the extremes of a biomechanical parameter due to an uncontrollable change in tissue structure and/or the respective testing setup.

Scanning Electron Microscopy of Microbial Attachment to Milk Contact Surfaces1

1981 ◽  
Vol 44 (3) ◽  
pp. 204-208 ◽  
Author(s):  
P. T. ZOLTAI ◽  
E. A. ZOTTOLA ◽  
L. L. MCKAY
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Stainless Steel ◽  
Fibrous Material ◽  
Microbial Colonization ◽  
Lactobacillus Bulgaricus ◽  
Stainless Steel Surface ◽  
Pseudomonas Fragi ◽  
Scanning Electron ◽  
Microbial Attachment

Milk contact surfaces were observed by scanning electron microscopy (SEM) techniques for possible microbial attachment. Cultures of Pseudomonas fragi 4973, Staphylococcus aureus JAL, Streptococcus lactis C2, Streptococcus cremoris and Lactobacillus bulgaricus RR inoculated onto glass coverslips or stainless steel chips were examined. Stainless steel surfaces displayed many possible harborages for microbial colonization. SEM examination of P. fragi 4973 showed development of fibrous material, with numerous stick-like projections extending from the cell to the glass or stainless steel surface. These apparent attachment appendages became more pronounced as contact time increased. S. aureus, S. lactis, S. cremoris and L. bulgaricus did not display such fibrous material.

Plastic embedding and surface erosion techniques in soft tissue scanning electron microscopy

1973 ◽  
Vol 99 (1) ◽  
pp. 69-74 ◽  
Author(s):  
I. G. S. Alexander ◽  
P. M. Capicchiano ◽  
B. C. Ritchie ◽  
J. E. Maloney
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Soft Tissue ◽  
Surface Erosion ◽  
Plastic Embedding ◽  
Scanning Electron

Collagen fibrils in the odontoblast layer of the rat incisor by scanning electron microscopy using the maceration method

1994 ◽  
Vol 239 (4) ◽  
pp. 360-370 ◽  
Author(s):  
Shoji Tabata ◽  
Tsuguhiro Nakayama ◽  
Kimitake Funakoshi ◽  
Kinya Yasui ◽  
Kaoru Wada ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Collagen Fibrils ◽  
Rat Incisor ◽  
Scanning Electron

Bone Resorption in Human Cholesteatoma: Morphological Study with Scanning Electron Microscopy

1995 ◽  
Vol 104 (6) ◽  
pp. 463-468 ◽  
Author(s):  
Yoshihumi Uno ◽  
Ryusuke Satto
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Bone Resorption ◽  
Bone Destruction ◽  
Collagen Fibrils ◽  
Fiber Bundles ◽  
Morphological Evidence ◽  
Middle Ear Surgery ◽  
Organic Substances ◽  
Scanning Electron

The detailed mechanism of bone resorption in cholesteatoma was investigated by means of eroded ossicles obtained during middle ear surgery for cholesteatoma. In the light microscopic study, multinucleate osteoclasts with ruffled borders were found in contact with the eroded bone, which appeared to be osteoclastic lacunae. Scanning electron microscopy revealed the lacunae to be many absorption bays, 30 to 100 μm in diameter, clustered on the surface of eroded areas. Numerous cone-shaped stubs of digested collagen fiber bundles, consisting of scores of collagen fibrils and degenerated extracellular organic substances, were visible at higher magnification on the bottom of the absorption bay. The pattern of fusion and twining of the disarranged collagen fibrils at the top of the partly digested fiber bundles was clearly rendered by the alkali-water maceration method for scanning electron microscopy. We infer from the morphological evidence that osteoclastic resorption may be one of the major mechanisms of bone destruction in cholesteatoma, and that demineralization and degeneration of extracellular organic substances precede disruption of collagen fibrils at the front of bone resorption.

scholarly journals Visualizing the 3D Architecture of Multiple Erythrocytes Infected with Plasmodium at Nanoscale by Focused Ion Beam-Scanning Electron Microscopy

PLoS ONE ◽  
2012 ◽  
Vol 7 (3) ◽  
pp. e33445 ◽  
Author(s):  
Lia Carolina Soares Medeiros ◽  
Wanderley De Souza ◽  
Chengge Jiao ◽  
Hector Barrabin ◽  
Kildare Miranda
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Beam Scanning ◽  
3D Architecture ◽  
Scanning Electron

scholarly journals Contrast-Enhanced Tissue Processing of Fibrillin-Rich Elastic Fibres for 3D Visualization by Volume Scanning Electron Microscopy

2021 ◽  
Vol 4 (3) ◽  
pp. 56
Author(s):  
Philip N. Lewis ◽  
Robert D. Young ◽  
R. B. Souza ◽  
Andrew J. Quantock ◽  
Keith M. Meek
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
3D Visualization ◽  
Elastic Fibre ◽  
Microscopical Examination ◽  
Elastic Fibres ◽  
Tissue Samples ◽  
Embedded Blocks ◽  
3D Architecture ◽  
Scanning Electron

Elastic fibres constitute an important component of the extracellular matrix and currently are the subject of intensive study in order to elucidate their assembly, function and involvement in cell–matrix interactions and disease. However, few studies to date have investigated the 3D architecture of the elastic fibre system in bulk tissue. We describe a protocol for preparation of tissue samples, including primary fixation and backscatter electron contrast-enhancement steps, through dehydration into stable resin-embedded blocks for volume electron microscopy. The use of low molecular weight tannic acid and alcoholic lead staining are critical stages in this procedure. Block preparation by ultramicrotomy and evaporative metal coating prior to microscopical examination are also described. We present images acquired from serial block face scanning electron microscopy of cornea and aorta showing target structures clearly differentiated from cells and other matrix components. The processing method imparts high contrast to fibrillin-containing elastic fibres, thus facilitating their segmentation and rendering into 3D reconstructions by image analysis software from large serial image datasets.

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