Statistical analysis of shrinkage levels of human brain slices preserved by sheet plastination technique with polyester resin / Análisis estadístico de los niveles de retracción de cortes de cerebro humano conservados mediante la técnica de plastinación de cortes con resina poliéster

Plastination is currently the most important anatomical preservation technique due to the possibility of preserving bodies and organs for an indefinite period, in a dry and biosecure form, while preserving the morphological characteristics of the tissues. However, the shrinkage of the samples is also part of the plastination, perhaps becoming one of its few disadvantages. This paper presents the shrinkage caused by the classic technique of sheet plastination with polyester resin (Biodur® P40) in human brain slices, with the aim of statistically establishing the percentages of tissue shrinkage caused by this plastination protocol.

La plastinación es actualmente la técnica de preservación anatómica más importante debido a la posibilidad de preservar los cuerpos y órganos por un período indefinido, en forma seca y biosegura, al tiempo que preserva las características morfológicas de los tejidos. Sin embargo, la retracción de las muestras también es parte de la plastinación, quizás convirtiéndose en una de sus pocas desventajas. Este artículo presenta la retracción causada por la técnica clásica de plastinación de cortes con resina poliéster (Biodur® P40) en cortes de cerebro humano, con el objetivo de establecer estadísticamente los porcentajes de retracción de tejidos causados por este protocolo de plastinación.

FIB-SEM of mouse nervous tissue: Fast and slow sample preparation.

Focused ion beam-scanning electron microscopy (FIB-SEM) has become a widely used technique in life sciences. To achieve the best data quality, sample preparation is important and has to be adapted to the specimen and the specific application. Here we illustrate three preparation procedures for mouse nervous tissue: First, the use of high-pressure freezing followed by direct imaging of vitrified tissue without any staining in the FIB-SEM under cryo-conditions as direct and fast procedure. Second, a slow procedure involving freeze substitution of frozen samples combined with additional staining for enhanced contrast and plastic embedding. Third, a fast preparation applying microwave-assisted chemical fixation and processing for resin embedding. All three methods of sample preparation are suitable for obtaining data stacks by FIB-SEM acquisition and 3D reconstruction.

Innovative, Simple Models for Teaching Neuroanatomy Using the Elnady Technique.

Plastination is a valuable tool for the teaching of neuroanatomy. However, the high cost of the process and the complexity of sheet plastination for brain slices remains a challenge. This article describes an innovative, simple, and inexpensive method, called the Elnady Technique, to develop brain slices of various domestic animals. The slices are either enveloped in lamination sheets using an electric iron, or enveloped in transparent plastic using an impulse sealer. This fast, effortless process results in realistic, durable, odorless, soft, flexible slices. The models provide accurate three-dimensional (3D) reference guides for demonstration of neuroanatomical structures that show soft tissue contrast between the gray and white matter. This makes them invaluable for interpretation of clinical imaging modalities, such as computed tomography (CT) and magnetic resonance imaging (MRI). These ethically sourced models can provide a replacement for the killing of animals for practical classes.

Sectional evaluation of anatomic structures in cat (Felis catus) thoracic cavity by computed tomography imaging and silicone plastination methods / Evaluación seccional de estructuras anatómicas de la cavidad torácica en gato (Felis catus) con imágenes de tomografía computada y métodos de plastinación de silicona

It was aimed to determine the anatomical structures in thoracic cavity by computed tomography imaging (CT) and compare the cross sectional images in the same specimens which were plastinated after CT imaging. It was also aimed to obtain 3 dimensional (3D) reconstructions of thoracic anatomical structures. Thoracic organs of 3 adult cats were CT imaged and then plastinated in this study. Specimens were plastinated in the same body position in the CT imaging process. CT images and corresponding plastinated cross sections were compared to each other. Anatomical structures of the thoracic cavity in plastinates were in accordance with CT images. Beside the bony structures, other organs such as esophagus, trachea, heart with related vessels, lungs and thoracic muscles were well defined in CT images and plastinates. Moreover, 3D reconstructed images of anatomical structures of thoracic cavity were acquired well. This study is thought to be beneficial for veterinary surgery and radiology fields as well as veterinary anatomy educations.

El objetivo de este trabajo consistió en determinar las estructuras anatómicas en la cavidad torácica mediante tomografía computarizada (TC) y comparar las imágenes transversales en las mismas muestras, que fueron plastinadas después de la TC. También se pretendía obtener reconstrucciones tridimensionales (3D) de estructuras anatómicas torácicas. Se tomaron imágenes de los órganos torácicos de 3 gatos adultos por TC y luego se plastinaron en este estudio. Las muestras se plastinaron en la misma posición corporal en el proceso de obtención de imágenes TC. Las imágenes de TC y las secciones transversales plastinadas correspondientes se compararon entre sí. Las estructuras anatómicas de la cavidad torácica en los preparados plastinados estaban de acuerdo con las imágenes de CT. Además de las estructuras óseas, otros órganos como el esófago, la tráquea, el corazón con vasos relacionados, los pulmones y los músculos torácicos estaban bien definidos en las imágenes de TC y los plastinados. Por otra parte, se captaron bien las imágenes reconstruidas en 3D de las estructuras anatómicas de la cavidad torácica. Pensamos que este estudio es beneficioso para la cirugía veterinaria y los campos de radiología, así como también para la educación de anatomía veterinaria.

Epoxy sheet plastination on a rabbit head - new faster protocol with Biodur® E12/E1 / Plastinación de cortes con resina epoxi en una cabeza de conejo - nuevo protocolo rápido con Biodur® E12/E1

SUMMARY: Plastination is an anatomical technique of cadaveric preservation that allows the preservation of anatomical pieces indefinitely, in dry and odorless form. It was created in 1978 by Gunther von Hagens, in Heidelberg, Germany. In particular, the sheet plastination technique, with epoxy resin, allows the generation of thin sections of various anatomical regions, allowing an accurate visualization of anatomical structures of difficult access through dissection or cadaveric exploration. The aim of this work was to present a new sheet plastination protocol with Biodur® E12/E1, which is faster in its implementation, applied, for the first time, in a rabbit head.

RESUMEN: La plastinación es una técnica anatómica de preservación cadavérica que permite la conservación de piezas anatómicas indefinidamente, en forma seca e inodora. Fue creada en 1978 por Gunther von Hagens, en Heidelberg, Alemania. En particular, la técnica de plastinación de cortes, con resina epoxi, permite la generación de secciones delgadas de diversas regiones anatómicas, asegurando una visualización precisa de estructuras anatómicas de difícil acceso mediante disección o exploración de cadáveres. El objetivo de este trabajo fue presentar un nuevo protocolo de plastinación de cortes con resina Biodur® E12/E1, más rápido en su implementación, aplicada por primera vez, en una cabeza de conejo.

Clear Resin Casting of Arthropods of Medical Importance for Use in Educational and Outreach Activities.

Arthropod-related morbidity and mortality represent a major threat to human and animal health. An important component of reducing vector-borne diseases and injuries is training the next generation of medical entomologists and educating the public in proper identification of arthropods of medical importance. One challenge of student training and public outreach is achieving a safe mounting technique that allows observation of morphological characteristics, while minimizing damage to specimens that are often difficult to replace. Although resin-embedded specimens are available from commercial retailers, there is a need for a published protocol that allows entomologists to economically create high-quality resin-embedded arthropods for use in teaching and outreach activities. We developed a detailed protocol using readily obtained equipment and supplies for creating resin-embedded arthropods of many species for use in teaching and outreach activities.

Resin-embedded anatomical cross-sections as a teaching adjunct for medical curricula: is this technique an alternative to potting and plastination?

With an ever-expanding use of cross-sectional imaging for diagnostic and therapeutic purposes, there has also been an increase in the need for exposure to such radiological and anatomical views at the undergraduate and postgraduate level to allow for early familiarisation with the relevant anatomy. Cadaveric cross-sections offer an excellent link between the two-dimensional radiological images and the three-dimensional anatomical structures. For such cross-sections to be useful and informative within educational settings, they need to be: (i) safe for students and trainees to handle and (ii) robust enough to withstand repeated handling; as well as (iii) displaying anatomy clearly and accurately. There are various ways in which cross-sections can be prepared and presented; plastinated, potted, vacuum-sealed or unmounted. Each of these approaches has advantages and disadvantages in terms of technical complexity, cost and quality. As an alternative to the above methods and their limitations, we propose the presentation of cadaveric cross-sections in a transparent polyester resin. This technique has been used extensively in craft and artistic industries, yet it is not publicised in anatomy teaching settings. The sections were layered in polyester resin contained within a mould. The set resin required finishing by sanding and polishing. The final cross-sections were safe to handle, durable and maintained excellent anatomical relationships of the contained structures. The transparency of the set resin was water-clear and did not obstruct the visibility of the anatomy. The cost of the process was found to be significantly lower, requiring less infrastructure when compared with alternative methods. The following trivial technical difficulties were noted during the resin-embedding process: trapped air causing organs to float; retained water in the anatomical specimens creating bubbles and discoloration; and microbubbles emerging from the solution affecting the finished surface. However, solutions to these minor limitations have been discussed within the paper with the aim of future proofing this technique. The sections have been used in undergraduate medical teaching for 4 years and they have shown no signs of degradation or discoloration. We believe that this method is a viable and cost-effective alternative to other approaches of displaying cross-sectional cadaveric material and will help students and trainees bridge the gap between the traditional three-dimensional anatomy and two-dimensional images.

Practicable methods for histological section thickness measurement in quantitative stereological analyses.

The accuracy of quantitative stereological analysis tools such as the (physical) disector method substantially depends on the precise determination of the thickness of the analyzed histological sections. One conventional method for measurement of histological section thickness is to re-embed the section of interest vertically to its original section plane. The section thickness is then measured in a subsequently prepared histological section of this orthogonally re-embedded sample. However, the orthogonal re-embedding (ORE) technique is quite work- and time-intensive and may produce inaccurate section thickness measurement values due to unintentional slightly oblique (non-orthogonal) positioning of the re-embedded sample-section. Here, an improved ORE method is presented, allowing for determination of the factual section plane angle of the re-embedded section, and correction of measured section thickness values for oblique (non-orthogonal) sectioning. For this, the analyzed section is mounted flat on a foil of known thickness (calibration foil) and both the section and the calibration foil are then vertically (re-)embedded. The section angle of the re-embedded section is then calculated from the deviation of the measured section thickness of the calibration foil and its factual thickness, using basic geometry. To find a practicable, fast, and accurate alternative to ORE, the suitability of spectral reflectance (SR) measurement for determination of plastic section thicknesses was evaluated. Using a commercially available optical reflectometer (F20, Filmetrics®, USA), the thicknesses of 0.5 µm thick semi-thin Epon (glycid ether)-sections and of 1-3 µm thick plastic sections (glycolmethacrylate/ methylmethacrylate, GMA/MMA), as regularly used in physical disector analyses, could precisely be measured within few seconds. Compared to the measured section thicknesses determined by ORE, SR measures displayed less than 1% deviation. Our results prove the applicability of SR to efficiently provide accurate section thickness measurements as a prerequisite for reliable estimates of dependent quantitative stereological parameters.

E12 sheet plastination: Techniques and applications.

Plastination is an anatomical technique that consists of replacing the liquids and fat of specimens by reactive polymers through forced impregnation in a vacuum. These are then polymerized to achieve the final result. E12 sheet plastination involves epoxy resin impregnation of thin (2-4 mm) and ultra-thin (<2 mm) tissue sheets, producing dry, transparent, odorless, non-toxic and long-lasting sheets. E12 sheet plastination techniques were reviewed using MEDLINE, EMBASE and SciELO databases, and manual searches. After searching, 616 records were found using the online and manual searches (MEDLINE, n: 207; EMBASE, n: 346; SciELO, n: 44; Manual search: 23). Finally, 96 records were included in this review (after duplicates and articles unrelated to the subject were excluded). The aim of this work was to review the E12 sheet plastination technique, searching for articles concerning views of it, identifying the different variants implemented by researchers since its creation by Gunther von Hagens, and to identify its applications from teaching and research in anatomy to morphological sciences. Clin. Anat. 31:742-756, 2018. © 2017 Wiley Periodicals, Inc.

Microstructural alterations owing to handling of bovine pericardium to manufacture bioprosthetic heart valves: A potential risk for cusp dehiscence.

INTRODUCTION: Cross-linking and anti-calcification of prosthetic heart valves have been continuously improved to prevent degeneration and calcification. However, non-calcific structural deteriorations such as cuspal dehiscences along the stent still require further analysis. MATERIAL AND METHOD: Based upon the previous analysis of an explanted valve after 7 years, a fresh commercial aortic valve was embedded in poly(methyl methacrylate) (PMMA) and cut into slices to ensure the detailed observation of the assembly and material structures. A pericardial patch embossed to provide the adequate shape of the cusps was investigated after paraffin embedding and appropriate staining. The microstructural damages that occurred during manufacturing process were identified and evaluated by light microscopy, polarized microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). RESULTS: The wavy collagen bundles, the key structure of the pericardium patch, were damaged to a great extent at suture sites along the stent and in the compressed areas around the stent post. The fixation of the embossed pericardium patch along the plots of the stent aggravated the microstructural modifications. The damages mainly appeared as the elimination of collagen bundle waviness and delamination between the bundles. CONCLUSION: Considering the modes of failure of the explant, the damages to the collagen bundles may identify the vulnerable sites that play an important role in the cusp dehiscence of heart valve implants. Such information is important to the manufacturers. Recommendations to prevent in vivo cusp dehiscence can therefore be formulated.

Digital preservation of anatomical variation: 3D-modeling of embalmed and plastinated cadaveric specimens using uCT and MRI.

Anatomy educators have an opportunity to teach anatomical variations as a part of medical and allied health curricula using both cadaveric and three-dimensional (3D) digital models of these specimens. Beyond published cadaveric case reports, anatomical variations identified during routine gross anatomy dissection can be powerful teaching tools and a medium to discuss several anatomical sub-disciplines from embryology to medical imaging. The purpose of this study is to document how cadaveric anatomical variation identified during routine dissection can be scanned using medical imaging techniques to create two-dimensional axial images and interactive 3D models for teaching and learning of anatomical variations. Three cadaveric specimens (2 formalin embalmed, 1 plastinated) depicting anatomical variations and an embryological malformation were scanned using magnetic resonance imaging (MRI) and micro-computed tomography (µCT) for visualization in cross-section and for creation of 3D volumetric models. Results provide educational options to enable visualization and facilitate learning of anatomical variations from cross-sectional scans. Furthermore, the variations can be highlighted, digitized, modeled and manipulated using 3D imaging software and viewed in the anatomy laboratory in conjunction with traditional anatomical dissection. This study provides an example for anatomy educators to teach and describe anatomical variations in the undergraduate medical curriculum.

Report on a sheet plastination technique using commercial epoxy resin / Reporte sobre una técnica de plastinación de cortes usando una resina epoxy comercial

Plastination is a conservation technique which allows anatomical pieces to be preserved, dry and odor-free, for an indefinite period. In particular, plastination of sections of tissue with epoxy resin allows very thin slices to be made of various regions of the anatomy, permitting close viewing of anatomical structures which are difficult to access by dissection or cadaver exploration. The objective of this work is to present a plastination technique developed in our laboratory for tissue sections using commercial epoxy resin, as an alternative to the existing classic plastination techniques. The technique was applied to a human knee, obtaining 5 mm thick sections which were compared with computerized tomography images. The development of an alternative sheet plastination technique using epoxy resin allows the preservation of anatomical regions which are difficult to study, with the possibility of comparing the sections with imaging studies. In this way anatomy can be usefully combined with clinical experience, allowing students to gain more significant knowledge of anatomy. The technique would also ensure provision of anatomical samples for research in the area of morphological science.

La plastinación es una técnica anatómica de conservación cadavérica que permite la preservación por tiempo indeterminado, en forma seca y sin olor, de piezas anatómicas. En particular, la técnica de plastinación por cortes, con resina epoxy, permite a su vez la generación de cortes delgados de diversas regiones anatómicas, permitiendo una visualización precisa de estructuras anatómicas de difícil acceso a través de la disección o la exploración cadavérica. El objetivo de este trabajo es el de presentar el desarrollo por parte de nuestro laboratorio de una técnica de plastinación de cortes con resina epoxy comercial, alternativa a las técnicas clásicas de plastinación de cortes existentes. Se aplicó la técnica en una rodilla humana, obteniéndose cortes de 5 mm de espesor, los cuales fueron comparados con imágenes de tomografía computada. El desarrollo de una técnica alternativa de plastinación de cortes con resina epoxy permitirá la conservación de regiones anatómicas de difícil estudio, con posibilidad de realizar la comparación de cortes con estudios imagenológicos, para combinar en forma adecuada la anatomía con la experiencia clínica y, de esta manera, permitir que el alumno alcance un aprendizaje más significativo de la anatomía, además de asegurar la obtención de muestras anatómicas para el desarrollo de investigación en el área de las ciencias morfológicas.

Plastinación y descripción anatómica de hígado, bazo, estómago y riñones del delfín nariz de botella (Tursiops truncatus) / Plastination and anatomy description of organs of the bottlenose dolphin (Tursiops truncatus)

Se plastinaron y describieron cuatro diferentes órganos internos de delfín nariz de botella (Tursiops truncatus) obteniendo modelos didácticos, perdurables gracias a la técnica de plastinación realizada en ellos, haciéndolos inodoros, no tóxicos y manipulables que permiten el estudio de los órganos internos como son el estómago, riñones e hígado de T. truncatus, contribuyendo a los trabajos de anatomía no patológica en delfines que son de importancia ecológica, turística y económica para nuestro país. Las descripciones anatómicas permiten avanzar en el conocimiento sobre los órganos internos, y si bien es cierto que se ha realizado un esfuerzo por estudiarlos existen pocos trabajos anatómicos realizados en ellos. Siendo este artículo una contribución al estudio de estos cetáceos.

Four different internal organs of bottlenose dolphin (Tursiops truncatus) were plastinated and described, obtaining didactic models, which let their components to be modified in an unaltered context; the resulting specimens are opaque and firm, but not unbreakable, with an appearance similar to that of the living state. The anatomical descriptions were made in concordance with those of the authors presented within the antecedents of this study; reinforcing the knowledge that the internal organs of T. truncatus described here typify those of mammals in general aspects, since the great uniformity between their structural elements is revealed. Moreover, there are very few non-pathological anatomic studies about dolphins, even though various mophometric and behavioral studies have been carried out, it still can be considered that several biological aspects of bottlenose dolphins remain to be described.

The cutting of ultrathin sections with the thickness less than 20 nm from biological specimens embedded in resin blocks.

Low voltage electron microscopes working in transmission mode, like LVEM5 (Delong Instruments, Czech Republic) working at accelerating voltage 5 kV or scanning electron microscope working in transmission mode with accelerating voltage below 1 kV, require ultrathin sections with the thickness below 20 nm. Decreasing of the primary electron energy leads to enhancement of image contrast, which is especially useful in the case of biological samples composed of elements with low atomic numbers. As a result treatments with heavy metals, like post-fixation with osmium tetroxide or ultrathin section staining, can by omitted. The disadvantage is reduced penetration ability of incident electrons influencing the usable thickness of the specimen resulting in the need of ultrathin sections of under 20 nm thickness. In this study we want to answer basic questions concerning the cutting of extremely ultrathin sections: Is it possible routinely and reproducibly to cut extremely thin sections of biological specimens embedded in commonly used resins with contemporary ultramicrotome techniques and under what conditions? Microsc. Res. Tech. 79:512-517, 2016. © 2016 Wiley Periodicals, Inc.

The Elnady Technique: An innovative, new method for tissue preservation.

At the Faculty of Veterinary Medicine, Cairo University, there is an increasing number of students but a limited availability of animal cadavers used for dissection, and student exposure to formalin is a known hazard. In order to address these challenges, a new method for tissue preservation was developed, the "Elnady Technique." This method is a modified form of plastination, where the chemicals used are not patented, are inexpensive and locally available, and the process is performed at room temperature. The produced specimens are realistic, durable, have no offensive odor, and are dry, soft and flexible. They can be used to replace the use of animals killed for teaching basic anatomy, embryology, pathology, parasitology and forensic medicine. They have great potential to support training in clinical skills and surgery, including for clinical examination, endoscopy, surgical sutures, and obstetrics simulation.

Patterns of attachment of the myodural bridge by the rectus capitis posterior minor muscle.

The myodural bridge was first described by Hack in 1995 and was thought to be related to chronic cervicogenic headaches. For a long time, few studies revealed the patterns of the myodural bridge considering the rectus capitis posterior minor muscle. In this study, P45 plastination technology and anatomical dissection were performed on head specimens, and four different terminal region types of the rectus capitis posterior minor muscle were observed, including the posterior atlanto-occipital interspace, posterior arch of the atlas and posterior atlanto-axial interspace. We propose that the myodural complex structures in the posterior atlanto-occipital and posterior atlanto-axial interspace have cooperative effects on cerebrospinal fluid and work together. This force might be an important source for the circulation of cerebrospinal fluid.

Glycol methacrylate embedding for the histochemical study of the gastrointestinal tract of dogs naturally infected with Leishmania infantum.

In canine visceral leishmaniasis a diffuse chronic inflammatory exudate and an intense parasite load throughout the gastrointestinal tract has been previously reported. However, these studies did not allow a properly description of canine cellular morphology details. The aim of our study was to better characterize these cells in carrying out a qualitative and quantitative histological study in the gastrointestinal tract of dogs naturally infected with Leishmania infantum by examining gut tissues embedded in glycol methacrylate. Twelve infected adult dogs were classified in asymptomatic and symptomatic. Five uninfected dogs were used as controls. After necropsy, three samples of each gut segment, including esophagus, stomach, duodenum, jejunum, ileum, cecum, colon, and rectum were collected and fixed in Carnoy's solution for glycol methacrylate protocols. Sections were stained with hematoxylin-eosin, toluidine blue borate, and periodic acid-Schiff stain. Leishmania amastigotes were detected by immunohistochemistry employed in both glycol methacrylate and paraffin embedded tissues. The quantitative histological analysis showed higher numbers of plasma cells, lymphocytes and macrophages in lamina propria of all segments of GIT of infected dogs than controls. The parasite load was more intense and cecum and colon, independently of the clinical status of these dogs. Importantly, glycol methacrylate embedded tissue stained with toluidine blue borate clearly revealed mast cell morphology, even after mast cell degranulation. Infected dogs showed lower numbers of mast cells in all gut segments than did controls. Despite the glycol methacrylate (GMA) protocol requires more attention and care than the conventional paraffin processing, this embedding procedure proved to be especially suitable for the present histological study, where it allowed to preserve and observe cell morphology in fine detail.

[THE METHODOLOGICAL BASIS FOR THE PLASTINATION OF BODY SAWCUTS].

The article describes the technique for making transparent lamellar human body slices using the method of plastination with epoxy resin. Different factors influencing the velocity of dehydration and impregnation of body slices were examined, the dependence of transparency of plastinated slices on the refraction coefficient of the epoxy composition was established. Physical and chemical methods for viscosity correction and optical refraction of epoxy resin composition were suggested. It was shown that plastinated slices with the thickness from 3 to 5 mm had the best demonstration characteristics. The technique suggested can be used for producing educational plastinated specimens for topographic anatomy and for clinical anatomical studies.

Defining the Morphology and Distribution of the Alar Fascia: A Sheet Plastination Investigation.

OBJECTIVES: This study aims to delineate the morphology, integrity, and distribution of the alar fascia using dissection and E12 sheet plastination. This is the first study that employs E12 sheet plastination to investigate the alar fascia and its adjacent potential spaces. METHODS: Twenty-nine manual dissections and 3 sets of E12 sheet plastinations were used to examine the posterior pharyngeal region for the architecture and distribution of the alar fascia. Specimens were examined from the inferior nuchal line to C6. RESULTS: The alar fascia originated as a well-defined midline structure at the level of C1 and could be identified down to C6. There was no evidence of the alar fascia between the inferior nuchal line and the base of the skull. Notably, the alar fascia permitted resistance to manual traction. CONCLUSIONS: E12 sheet plastination allowed for visualization of the alar fascia's superior attachments within the deep cervical region. Resistance to traction suggests that the alar fascia may be more than just a loose fibroareolar matrix. The findings in this study suggest an alternative point of entry into the danger space. Understanding the continuity of this fascial layer is critically important with regard to the pathophysiology of deep neck space infections.