Structural preservation and absolute contrast of catalase crystal sections prepared with tannic acid

1983 ◽  
Vol 41 ◽  
pp. 448-449
Author(s):  
C.W. Akey ◽  
M. Szalay ◽  
S.J. Edelstein
Keyword(s):  
Tannic Acid ◽  
Beef Heart ◽  
X Rays ◽  
Screw Axis ◽  
General Applicability ◽  
Thin Sections ◽  
Beef Liver ◽  
3 Dimensional ◽  
Dimensional Reconstruction ◽  
Structural Preservation

Three methods of obtaining 20 Å resolution in sectioned protein crystals have recently been described. They include tannic acid fixation, low temperature embedding and grid sectioning. To be useful for 3-dimensional reconstruction thin sections must possess suitable resolution, structural fidelity and a known contrast. Tannic acid fixation appears to satisfy the above criteria based on studies of crystals of Pseudomonas cytochrome oxidase, orthorhombic beef liver catalase and beef heart F1-ATPase. In order to develop methods with general applicability, we have concentrated our efforts on a trigonal modification of catalase which routinely demonstrated a resolution of 40 Å. The catalase system is particularly useful since a comparison with the structure recently solved with x-rays will permit evaluation of the accuracy of 3-D reconstructions of sectioned crystals.Initially, we re-evaluated the packing of trigonal catalase crystals studied by Longley. Images of the (001) plane are of particular interest since they give a projection down the 31-screw axis in space group P3121. Images obtained by the method of Longley or by tannic acid fixation are negatively contrasted since control experiments with orthorhombic catalase plates yield negatively stained specimens with conditions used for the larger trigonal crystals.

Three-Dimensional Reconstruction Using Stereo Pairs from Serial Thick Sections

1977 ◽  
Vol 35 ◽  
pp. 562-563
Author(s):  
Robert Glaeser ◽  
Thomas Bauer ◽  
David Grano
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
Serial Sections ◽  
Thin Sections ◽  
3 Dimensional ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Dimensional Reconstruction ◽  
Stereo Imagery ◽  
Whole Mounts

In transmission electron microscopy, the 3-dimensional structure of an object is usually obtained in one of two ways. For objects which can be included in one specimen, as for example with elements included in freeze- dried whole mounts and examined with a high voltage microscope, stereo pairs can be obtained which exhibit the 3-D structure of the element. For objects which can not be included in one specimen, the 3-D shape is obtained by reconstruction from serial sections. However, without stereo imagery, only detail which remains constant within the thickness of the section can be used in the reconstruction; consequently, the choice is between a low resolution reconstruction using a few thick sections and a better resolution reconstruction using many thin sections, generally a tedious chore. This paper describes an approach to 3-D reconstruction which uses stereo images of serial thick sections to reconstruct an object including detail which changes within the depth of an individual thick section.

Three-dimensional reconstruction of large subcellular structures: A method for combining axial tilt tomography with serial reconstruction of thick sections

1992 ◽  
Vol 50 (1) ◽  
pp. 904-905
Author(s):  
Gabriel E. Soto ◽  
Maryann E. Martone ◽  
Stephan Lamont ◽  
Bridget O. Carragher ◽  
Thomas J. Deerinck ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Electron Microscopic Observation ◽  
Electron Microscopic ◽  
High Voltage Electron Microscopy ◽  
Thin Sections ◽  
3 Dimensional ◽  
Voltage Electron ◽  
Large Numbers ◽  
Dimensional Reconstruction ◽  
Axial Tilt

The study of subcellular structures requires the resolution afforded by the electron microscope. However, cellular organelle systems can extend for tens of microns and therefore cannot be encompassed in a single thin section required for conventional electron microscopic observation. Even with the use of high voltage electron microscopy, section thickness is limited to no more than a few microns. Visualization of 3-dimensional cellular structure in large volumes of tissue can be achieved by using 3-dimensional reconstructions based on serial sections. This approach is often tedious, requiring an extremely large series of thin sections in order to encompass the structure of interest. This method also suffers from technical difficulties in obtaining, processing and maintaining adequate registration over large numbers of sections. We have been exploring a method in which the number of sections is reduced by employing a series of thick sections in which the structures of interest are selectively stained. Three-dimensional information is extracted from each section using axial tilt tomography. The resulting serial volumes are then aligned and linked to form a single volume which is displayed using volume rendering techniques.

scholarly journals CBCT's Cone Beam Computed Tomography

2014 ◽  
Vol 1 (1) ◽  
pp. 9
Author(s):  
Sahithya Kailash
Keyword(s):  
Computed Tomography ◽  
Panoramic Radiography ◽  
Cone Beam ◽  
X Rays ◽  
Health Issues ◽  
X Ray ◽  
3 Dimensional ◽  
Area Of Interest ◽  
Multiplanar Imaging ◽  
Dimensional Reconstruction

Dental X- Rays are important for diagnosing and treating patients by helping to detect oral health issues when they can't be detected by visual or physical examination alone. Dental X-Ray take a much closer look and provide valuable information in the area of interest. Though 2 Dimensional X-Ray and Panoramic radiography can predict diagnosis in number of clinical cases, certain situations demand multiplanar imaging, one such technology is CBCT. CBCT is a specialised 3Dimensional Craniofacial imaging in which 3 Dimensional reconstruction is possible. The final reconstructed image produced, reveals multilayer images in 3 orthogonal planes (coronal, sagittal and transverse) This article focuses on CBCT and its applications in various fields of dentistry.

3-D reconstruction of molecular shape from microcrystal thin sections

1983 ◽  
Vol 41 ◽  
pp. 748-749
Author(s):  
S. Cusack ◽  
J.-C. Jésior
Keyword(s):  
Three Dimensional ◽  
Molecular Shape ◽  
Biological Molecules ◽  
Fourier Space ◽  
Single Particles ◽  
Thin Sections ◽  
Standard Methods ◽  
X Ray ◽  
X Ray Crystallography ◽  
Dimensional Reconstruction

Three-dimensional reconstruction techniques using electron microscopy have been principally developed for application to 2-D arrays (i.e. monolayers) of biological molecules and symmetrical single particles (e.g. helical viruses). However many biological molecules that crystallise form multilayered microcrystals which are unsuitable for study by either the standard methods of 3-D reconstruction or, because of their size, by X-ray crystallography. The grid sectioning technique enables a number of different projections of such microcrystals to be obtained in well defined directions (e.g. parallel to crystal axes) and poses the problem of how best these projections can be used to reconstruct the packing and shape of the molecules forming the microcrystal.Given sufficient projections there may be enough information to do a crystallographic reconstruction in Fourier space. We however have considered the situation where only a limited number of projections are available, as for example in the case of catalase platelets where three orthogonal and two diagonal projections have been obtained (Fig. 1).

Cell Fine Structure as Revealed in Dessicator-Dried Resinless Sections

1981 ◽  
Vol 39 ◽  
pp. 622-623
Author(s):  
R. P. Becker ◽  
J. J. Wolosewick ◽  
J. Ross-Stanton
Keyword(s):  
Fine Structure ◽  
Tannic Acid ◽  
Three Dimensional ◽  
Albino Rats ◽  
Cell Organelles ◽  
Vascular Perfusion ◽  
Thin Sections ◽  
Carbon Coated ◽  
Embedding Medium ◽  
Polyethylene Glycol 6000

Methodology has been introduced recently which allows transmission and scanning electron microscopy of cell fine structure in semi-thin sections unencumbered by an embedding medium. Images obtained from these “resinless” sections show a three-dimensional lattice of microtrabeculfee contiguous with cytoskeletal structures and membrane-bounded cell organelles. Visualization of these structures, especially of the matiiDra-nous components, can be facilitated by employing tannic acid in the fixation step and dessicator drying, as reported here.Albino rats were fixed by vascular perfusion with 2% glutaraldehyde or 1.5% depolymerized paraformaldehyde plus 2.5% glutaraldehyde in 0.1M sodium cacodylate (pH 7.4). Tissues were removed and minced in the fixative and stored overnight in fixative containing 4% tannic acid. The tissues were rinsed in buffer (0.2M cacodylate), exposed to 1% buffered osmium tetroxide, dehydrated in ethyl alcohol, and embedded in pure polyethylene glycol-6000 (PEG). Sections were cut on glass knives with a Sorvall MT-1 microtome and mounted onto poly-L-lysine, formvar-carbon coated grids while submerged in a solution of 95% ethanol containing 5% PEG.

Spot-scan imaging of ice-embedded catalase crystal on a slow-scan CCD camera in a 400-kV electron cryomicroscope

1994 ◽  
Vol 52 ◽  
pp. 98-99
Author(s):  
Wah Chiu ◽  
Michael Sherman ◽  
Jaap Brink
Keyword(s):  
Electron Diffraction ◽  
Ccd Camera ◽  
Protein Crystal ◽  
Modulation Transfer ◽  
Measured Intensity ◽  
3 Dimensional ◽  
Dimensional Reconstruction ◽  
Diffraction Patterns ◽  
Complex Crystal

In protein electron crystallography, both low dose electron diffraction patterns and images are needed to provide accurate amplitudes and phases respectively for a 3-dimensional reconstruction. We have demonstrated that the Gatan 1024x1024 model 679 slow-scan CCD camera is useful to record electron diffraction intensities of glucose-embedded crotoxin complex crystal to 3 Å resolution. The quality of the electron diffraction intensities is high on the basis of the measured intensity equivalence ofthe Friedel-related reflections. Moreover, the number of patterns recorded from a single crystal can be as high as 120 under the constraints of radiation damage and electron statistics for the reflections in each pattern.A limitation of the slow-scan CCD camera for recording electron images of protein crystal arises from the relatively large pixel size, i.e. 24 μm (provided by Gatan). The modulation transfer function of our camera with a P43 scintillator has been determined for 400 keV electrons and shows an amplitude fall-off to 0.25 at 1/60 μm−1.

Immunolocalization of nuclear antigens in cryofixed cells which have been prepared by molecular distillation drying or freeze-substitution

1990 ◽  
Vol 48 (3) ◽  
pp. 898-899
Author(s):  
David L. Spector ◽  
Robert J. Derby
Keyword(s):  
Cell Nucleus ◽  
Molecular Distillation ◽  
Functional Organization ◽  
Freeze Substitution ◽  
3 Dimensional ◽  
Small Nuclear Ribonucleoprotein ◽  
Nuclear Antigens ◽  
Dimensional Reconstruction ◽  
Nuclear Regions ◽  
Immunoperoxidase Labeling

Studies in our laboratory are involved in evaluating the structural and functional organization of the mammalian cell nucleus. Since several major classes (U1, U2, U4/U6, U5) of small nuclear ribonucleoprotein particles (snRNPs) play a crucial role in the processing of pre-mRNA molecules, we have been interested in the localization of these particles within the cell nucleus. Using pre-embedding immunoperoxidase labeling combined with 3-dimensional reconstruction, we have recently shown that nuclear regions enriched in snRNPs form a reticular network within the nucleoplasm which extends between the nucleolar surface and the nuclear envelope. In the present study we were inte rested in extending these nuclear localizations using cell preparation techniques which avoid slow penetration of fixatives, chemical crosslinking of potential antigens and solvent extraction. CHOC 400 cells were cryofixed using a CF 100 ultra rapid cooling device (LifeCell Corp.). After cryofixation cells were molecular distillation dried, vapor osmicated, in filtra ted in 100% Spurr resin in vacuo and polymerized in molds a t 60°C. Using this procedure we were able to evaluate the distribution of snRNPs in resin embedded cells which had not been chemically fixed, incubated in cryoprotectants or extracted with solvents.

Computational Analysis of Olfactory Airspace in Patients With Unilateral Cleft Lip Nasal Deformity

2020 ◽  
pp. 105566562098275
Author(s):  
Reanna Shah ◽  
Jeffrey R. Marcus ◽  
Dennis O. Frank-Ito
Keyword(s):  
Cleft Lip ◽  
Computational Analysis ◽  
Normal Subjects ◽  
Nasal Deformity ◽  
Normal Anatomy ◽  
3 Dimensional ◽  
Computed Tomography Images ◽  
High Prevalence ◽  
Dimensional Reconstruction ◽  
The Impact

Objectives: To evaluate the magnitude of olfactory recess opacity in patients with unilateral cleft lip nasal deformity (uCLND). Design: Subject-specific 3-dimensional reconstruction of the nasal airway anatomy was created from computed tomography images in 11 (4 males and 7 females) subjects with uCLND and 7 (3 males, and 4 females) normal subjects. The volume and surface area of each subject’s unilateral and bilateral olfactory airspace was quantified to assess the impact of opacification. Qualitatively speaking, patients with 75% to 100% olfactory recess opacification were classified as extreme, 50% to 75% as severe, 25% to 50% as moderate, and 0% to 25% as mild. Results: Of the 11 subjects with uCLND, 5 (45%) were classified as having extreme olfactory recess opacification, 3 (27%) subjects had severe opacification, and 3 (27%) subjects had moderate opacification. Mean (±SD) bilateral olfactory recess volume was significantly greater in normal subjects than in subjects with uCLND (0.9668 cm3 ± 0.4061 cm3 vs 0.3426 cm3 ± 0.1316 cm3; P < .001). Furthermore, unilateral olfactory airspace volumes for the cleft and non-cleft sides in subjects with uCLND were considerably less than unilateral olfactory volume in subjects with normal anatomy (uCLND cleft side = 0.1623 cm3 ± 0.0933 cm3; uCLND non-cleft side = 0.1803 cm3 ± 0.0938 cm3; normal = 0.4834 cm3 ± 0.2328 cm3; P < .001). Conclusions: Our findings indicate a high prevalence of olfactory recess opacification among subjects with uCLND when compared to subjects with normal anatomy. The majority of subjects with uCLND had extreme olfactory recess opacity, which will likely influence their sense of smell.

scholarly journals Airway Abnormalities in Adult Mucopolysaccharidosis and Development of Salford Mucopolysaccharidosis Airway Score

2021 ◽  
Vol 10 (15) ◽  
pp. 3275
Author(s):  
Chaitanya Gadepalli ◽  
Karolina M. Stepien ◽  
Reena Sharma ◽  
Ana Jovanovic ◽  
Govind Tol ◽  
...  
Keyword(s):  
Airway Disease ◽  
Lysosomal Storage ◽  
Cross Sectional ◽  
Airway Narrowing ◽  
3 Dimensional ◽  
Multiple Parameters ◽  
Validated Questionnaire ◽  
Dimensional Reconstruction ◽  
Cross Sectional Imaging ◽  
Airway Abnormalities

(1) Background: Mucopolysaccharidoses (MPS) are a heterogeneous group of lysosomal storage disorders caused by the absence of enzymes required for degradation of glycosaminoglycans (GAGs). GAGs deposition in tissues leads to progressive airway narrowing and/or tortuosity. Increased longevity of patients has posed newer problems, especially the airway. This study aims to characterise various airway abnormalities in adult MPS from a regional centre and proposes a method to quantify the severity of the airway disease. (2) Methods: Retrospective analysis by case notes review, clinical examination, endoscopy, cross-sectional imaging, 3-dimensional reconstruction, and physiological investigations were used to assess the airway abnormalities. Quantitative assessment of the airway severity was performed a validated questionnaire of 15 parameters to derive Salford Mucopolysaccharidosis Airway Score (SMAS). (3) Results: Thirty-one adult MPS patients (21M/ 9F; median 26.7 years; range 19–42 years) were reviewed. There were 9 MPS I, 12 MPS II, 2 MPS III, 5 MPS IV, 2 MPS VI, and 1 MPS VII. Airway abnormalities in each MPS type are described. Patients scoring more than 35 on SMAS had some form of airway intervention. The area under curve of 0.9 was noted at a score of 25, so SMAS more than 25 may predict a difficult airway and potential to have complications. Pearson’s correlation between SMAS and height, weight, BMI were poor (p < 0.05). (4) Conclusions: Airway abnormalities in adult MPS are varied and complex. Assessment of the airway should be holistic and include multiple parameters. An objective multidimensional score such as SMAS may help to predict and manage difficult airways warranting further investigation and validation.

scholarly journals High-resolution limited-angle phase tomography of dense layered objects using deep neural networks

2019 ◽  
Vol 116 (40) ◽  
pp. 19848-19856 ◽  
Author(s):  
Alexandre Goy ◽  
Girish Rughoobur ◽  
Shuai Li ◽  
Kwabena Arthur ◽  
Akintunde I. Akinwande ◽  
...  
Keyword(s):  
Integrated Circuit ◽  
Deep Neural Networks ◽  
Tomographic Reconstruction ◽  
Synthetic Data ◽  
Single Step ◽  
Training Set ◽  
Step Method ◽  
3 Dimensional ◽  
Dimensional Reconstruction ◽  
Optical Domain

We present a machine learning-based method for tomographic reconstruction of dense layered objects, with range of projection angles limited to ±10○. Whereas previous approaches to phase tomography generally require 2 steps, first to retrieve phase projections from intensity projections and then to perform tomographic reconstruction on the retrieved phase projections, in our work a physics-informed preprocessor followed by a deep neural network (DNN) conduct the 3-dimensional reconstruction directly from the intensity projections. We demonstrate this single-step method experimentally in the visible optical domain on a scaled-up integrated circuit phantom. We show that even under conditions of highly attenuated photon fluxes a DNN trained only on synthetic data can be used to successfully reconstruct physical samples disjoint from the synthetic training set. Thus, the need for producing a large number of physical examples for training is ameliorated. The method is generally applicable to tomography with electromagnetic or other types of radiation at all bands.

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