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

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.

scholarly journals Rapid chemical dehydration of biologic samples for scanning electron microscopy using 2,2-dimethoxypropane.

1977 ◽  
Vol 25 (4) ◽  
pp. 247-251 ◽  
Author(s):  
M D Maser ◽  
J J Trimble
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Small Intestine ◽  
Cultured Fibroblasts ◽  
Critical Point Drying ◽  
Mouse Small Intestine ◽  
Fine Surface ◽  
Plastic Embedding ◽  
Rat Trachea ◽  
Scanning Electron

Acidified 2,2-dimethoxypropane (DMP) has been used as a rapid chemical dehydrating agent en route to plastic embedding and ulthrathin sectioning for conventional electron miscroscopy (J Histochem Cytochem 23:107, 1975). We have used DMP to dehydrate biologic specimens prior to critical point drying and metal coating for scanning electron microscopy. There is no difference in either the gross architecture or the fine surface structure of mouse small intestine and trachea, rat trachea and kidney, and cultured fibroblasts, between samples dehydrated in DMP for 5 min to 30 days and those conventionally dehydrated in ethanol or acetone. DMP dehydration is advantageous in speed, economy and apparent completeness.

scholarly journals Exceptional preservation of soft tissue in a new specimen of Eoconfuciusornis and its biological implications

2017 ◽  
Vol 4 (3) ◽  
pp. 441-452 ◽  
Author(s):  
Xiaoting Zheng ◽  
Jingmai K. O’Connor ◽  
Xiaoli Wang ◽  
Yanhong Pan ◽  
Yan Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Soft Tissue ◽  
Soft Tissues ◽  
Support Network ◽  
Sexually Dimorphic ◽  
Remarkable Similarity ◽  
Exceptional Preservation ◽  
Internal Support ◽  
Scanning Electron

Abstract We report on an exceptional specimen of Eoconfuciusornis preserving rare soft-tissue traces of the ovary and wing. Ovarian follicles preserve a greater hierarchy than observed in Jeholornis and enantiornithines, suggesting confuciusornithiforms evolved higher rates of yolk deposition in parallel with the neornithine lineage. The preserved soft tissues of the wing indicate the presence of a propatagium and postpatagium, whereas an alular patagium is absent. Preserved remnants of the internal support network of the propatagium bear remarkable similarity to that of living birds. Soft tissue suggests the confuciusornithiform propatagium could maintain a cambered profile and generate lift. The feathers of the wing preserve remnants of their original patterning; however, this is not strongly reflected by observable differences under scanning electron microscopy (SEM). The tail plumage lacks elongate rectrices, suggesting that the earliest known confuciusornithiforms were sexually dimorphic in their plumage.

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.

Pathogenesis of Human Hair Defects

1974 ◽  
Vol 32 ◽  
pp. 12-13
Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Human Hair ◽  
Standard Techniques ◽  
Scanning Electron

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

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