scholarly journals Exceptional soft tissues preservation in a mummified frog-eating Eocene salamander

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3861 ◽  
Author(s):  
Jérémy Tissier ◽  
Jean-Claude Rage ◽  
Michel Laurin
Keyword(s):  
Digestive Tract ◽  
Evolutionary Biology ◽  
Soft Tissues ◽  
Three Dimensional ◽  
Exceptional Case ◽  
Three Dimensions ◽  
Rare Type ◽  
Internal Structures ◽  
Close Source ◽  
Shed Light

Fossils are almost always represented by hard tissues but we present here the exceptional case of a three-dimensionally preserved specimen that was ‘mummified’ (likely between 40 and 34 million years ago) in a terrestrial karstic environment. This fossil is the incomplete body of a salamander, Phosphotriton sigei, whose skeleton and external morphology are well preserved, as revealed by phase-contrast synchrotron X-ray microtomography. In addition, internal structures composed of soft tissues preserved in three dimensions are now identified: a lung, the spinal cord, a lumbosacral plexus, the digestive tract, muscles and urogenital organs that may be cloacal glands. These are among the oldest known cases of three-dimensional preservation of these organs in vertebrates and shed light on the ecology of this salamander. Indeed, the digestive tract contains remains of a frog, which represents the only known case of an extinct salamander that fed on a frog, an extremely rare type of predation in extant salamanders. These new data improve our scarce knowledge on soft tissue anatomy of early urodeles and should prove useful for future biologists and palaeontologists working on urodele evolutionary biology. We also suggest that the presence of bat guano and carcasses represented a close source of phosphorus, favouring preservation of soft tissues. Bone microanatomy indicates that P. sigei was likely amphibious or terrestrial, and was probably not neotenic.

Preparation of serial sections

1989 ◽  
Vol 4 ◽  
pp. 146-156 ◽  
Author(s):  
Michael R. Sandy
Keyword(s):  
Three Dimensional ◽  
Diamond Wheel ◽  
Three Dimensions ◽  
Serial Sections ◽  
Serial Sectioning ◽  
Permanent Record ◽  
Glass Slides ◽  
Internal Structures ◽  
Abrasive Surface ◽  
Saw Blade

Serial sectioning (also referred to as serial grinding) is used to investigate the internal structures of three-dimensional (rock or fossil). In this process series of sections are ground or cut in sequence through a specimen to reveal its internal structures. The specimen is ground down against an abrasive surface (e.g., abrasive powder on a sheet of steel or a rotating diamond wheel on a lathe) or cut with a saw blade. The details of each section can be recorded by drawing or photography. A permanent record of each surface can be made by taking acetate peels and mounting them in glass slides (Wilson and Palmer, this volume, Chapter 13). Serial section information can be digitized and reconstructed in three-dimensions using computer techniques (Chapman, this volume, Chapter 15).

scholarly journals Micro Soft Tissues Visualization Based on X-Ray Phase-Contrast Imaging

2011 ◽  
Vol 5 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Lu Zhang ◽  
Shuqian Luo
Keyword(s):  
Phase Contrast ◽  
Soft Tissues ◽  
Early Stage ◽  
Blood Clot ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Phase Contrast Imaging ◽  
Contrast Imaging ◽  
X Ray ◽  
Non Invasive

The current imaging methods have a limited ability to visualize microstructures of biological soft tissues. Small lesions cannot be detected at the early stage of the disease. Phase contrast imaging (PCI) is a novel non-invasive imaging technique that can provide high contrast images of soft tissues by the use of X-ray phase shift. It is a new choice in terms of non-invasively revealing soft tissue details. In this study, the lung and hepatic fibrosis models of mice and rats were used to investigate the ability of PCI in microstructures observation of soft tissues. Our results demonstrated that different liver fibrosis stages could be distinguished non-invasively by PCI. The three-dimensional morphology of a segment of blood vessel was constructed. Noteworthy, the blood clot inside the vessel was visualized in three dimensions which provided a precise description of vessel stenosis. Furthermore, the whole lung airways including the alveoli were obtained. We had specifically highlighted its use in the visualization and assessment of the alveoli. To our knowledge, this was the first time for non-invasive alveoli imaging using PCI. This finding may offer a new perspective on the diagnosis of respiratory disease. All the results confirmed that PCI will be a valuable tool in biological soft tissues imaging.

scholarly journals Burgess Shale fossils shed light on the agnostid problem

2019 ◽  
Vol 286 (1894) ◽  
pp. 20182314 ◽  
Author(s):  
J. Moysiuk ◽  
J.-B. Caron
Keyword(s):  
British Columbia ◽  
Digestive Tract ◽  
Soft Tissues ◽  
Sister Group ◽  
Burgess Shale ◽  
Middle Cambrian ◽  
Important Group ◽  
Alternative Hypotheses ◽  
Shed Light

Agnostids (agnostinids and eodiscinids) are a widespread and biostratigraphically important group of Cambro-Ordovician euarthropods whose evolutionary affinities have been highly controversial. Their dumbbell-shaped calcified tergum was traditionally suggested to unite them with trilobites, but agnostinids have alternatively been interpreted as stem-crustaceans, based on Orsten larval material from the Cambrian of Sweden. We describe exceptionally preserved soft tissues from mature individuals of the agnostinids Peronopsis and Ptychagnostus from the middle Cambrian (Wuliuan Stage) Burgess Shale (Walcott Quarry and Marble Canyon, British Columbia, Canada), facilitating the testing of alternative hypotheses. The digestive tract includes conspicuous ramifying cephalic diverticulae. The cephalon carries one pair of elongate spinous antennules projecting to the front, two pairs of appendages with distally setose, oar-like exopods, and three pairs of presumably biramous appendages with endopods sporting club-shaped exites. The trunk bears five appendage pairs, at least the first two of which are similar to the posteriormost cephalic pairs. The combined evidence supports a nektobenthic and detritivorous lifestyle for agnostinids. A head with six appendiferous segments contrasts strikingly with the four known in trilobites and five typical of mandibulates. Agnostinids are retrieved as the sister group to polymeroid trilobites in our phylogeny, implying that crustacean-like morphologies evolved homoplastically. This result highlights the variability in segmental composition of the artiopodan head. Finally, our study emphasizes the continued role of Burgess Shale-type fossils in resolving the affinities of problematic biomineralizing taxa.

Precision, Repeatability, and Validation of the Localization of Cranial Landmarks Using Computed Tomography Scans

1995 ◽  
Vol 32 (3) ◽  
pp. 217-227 ◽  
Author(s):  
Joan T. Richtsmeier ◽  
Chul H. Paik ◽  
Peter C. Elfert ◽  
Theodore M. Cole ◽  
Holly R. Dahlman
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Ct Scans ◽  
Average Error ◽  
Measurement Systems ◽  
Three Dimensional Representation ◽  
Internal Structures ◽  
Means Of Measurement ◽  
Ct Data

Computed tomography (CT) has brought to the craniofacial surgeon a three-dimensional representation of internal structures. CT scans provide visualization of anatomy for preoperative planning and postoperative evaluation. Beyond visualization, however, a CT scan enables assessment of measurements useful to clinicians and basic scientists. All measurement systems used with CT require the ability to accurately locate regions of interest on the image (i.e., areas, volumes, outlines, curves, surfaces, points). This study evaluates the precision and repeatability of locating anatomic landmarks in three dimensions on CT slice images, and validates these locations using an established measurement system. The average error of landmark position is always less than 0.5 mm and for some landmarks error is negligible. Repeatability studies show that less than 2% of the total variance in our data is due to measurement inaccuracy. Although data collected from CT scans are internally consistent, validation results caution the use of CT data In combination with data collected using calipers or other direct means of measurement.

convergent-beam diffraction from surfaces

1987 ◽  
Vol 45 ◽  
pp. 30-33
Author(s):  
J. A. Eades ◽  
A. E. Smith ◽  
D. F. Lynch
Keyword(s):  
Reciprocal Lattice ◽  
Three Dimensional ◽  
Grazing Incidence ◽  
Three Dimensions ◽  
Plane Figure ◽  
Transmission Electron ◽  
Convergent Beam ◽  
Beam Patterns ◽  
Beam Diffraction

It is quite simple (in the transmission electron microscope) to obtain convergent-beam patterns from the surface of a bulk crystal. The beam is focussed onto the surface at near grazing incidence (figure 1) and if the surface is flat the appropriate pattern is obtained in the diffraction plane (figure 2). Such patterns are potentially valuable for the characterization of surfaces just as normal convergent-beam patterns are valuable for the characterization of crystals.There are, however, several important ways in which reflection diffraction from surfaces differs from the more familiar electron diffraction in transmission.GeometryIn reflection diffraction, because of the surface, it is not possible to describe the specimen as periodic in three dimensions, nor is it possible to associate diffraction with a conventional three-dimensional reciprocal lattice.

Extension of the Spatial PDI Model to Three Dimensions

1997 ◽  
Vol 84 (1) ◽  
pp. 176-178
Author(s):  
Frank O'Brien
Keyword(s):  
Population Density ◽  
Dimensional Space ◽  
Finite Lattice ◽  
Three Dimensional ◽  
Upper Bounds ◽  
Three Dimensions ◽  
Lower And Upper Bounds ◽  
Density Index ◽  
Three Dimensional Space

The author's population density index ( PDI) model is extended to three-dimensional distributions. A derived formula is presented that allows for the calculation of the lower and upper bounds of density in three-dimensional space for any finite lattice.

Adult Acquired Flatfoot

2020 ◽  
Vol 62 (1) ◽  
pp. 55-59
Author(s):  
Krzysztof Mataczyński ◽  
Mateusz Pelc ◽  
Halina Romualda Zięba ◽  
Zuzana Hudakova
Keyword(s):  
Soft Tissues ◽  
Three Dimensional ◽  
Clinical Diagnostics ◽  
Clinical Image ◽  
Tibialis Posterior ◽  
Dynamic Force ◽  
Posterior Tibial ◽  
Flat Feet ◽  
Foot Arch ◽  
Motion Range

Acquired adult flatfoot is a three-dimensional deformation, which consists of hindfoot valgus, collapse of the longitudinal arch of the foot and adduction of the forefoot. The aim of the work is to present problems related to etiology, biomechanics, clinical diagnostics and treatment principles of acquired flatfoot. The most common cause in adults is the dysfunction of the tibialis posterior muscle, leading to the lack of blocking of the transverse tarsal joint during heel elevation. Loading the unblocked joints consequently leads to ligament failure. The clinical image is dominated by pain in the foot and tibiotarsal joint. The physical examination of the flat feet consists of: inspection, palpation, motion range assessment and dynamic force assessment. The comparable attention should be paid to the height of the foot arch, the occurrence of “too many toes” sign, evaluate the heel- rise test and correction of the flatfoot, exclude Achilles tendon contracture. The diagnosis also uses imaging tests. In elastic deformations with symptoms of posterior tibial tendonitis, non-steroidal anti-inflammatory drugs, short-term immobilization, orthotics stabilizing the medial arch of the foot are used. In rehabilitation, active exercises of the shin muscles and the feet, especially the eccentric exercises of the posterior tibial muscle, are intentional. The physiotherapy and balneotherapy treatments, in particular hydrotherapy, electrotherapy and laser therapy, are used as a support. In advanced lesions, surgical treatment may be necessary, including plastic surgery of soft tissues, tendons, as well as osteotomy procedures.

3D Culture Modelling: An Emerging Approach for Translational Cancer Research in Sarcomas

2020 ◽  
Vol 27 (29) ◽  
pp. 4778-4788 ◽  
Author(s):  
Victoria Heredia-Soto ◽  
Andrés Redondo ◽  
José Juan Pozo Kreilinger ◽  
Virginia Martínez-Marín ◽  
Alberto Berjón ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
Cancer Biology ◽  
Soft Tissues ◽  
Three Dimensional ◽  
3D Culture ◽  
Resistance Mechanisms ◽  
In Vitro Models ◽  
Tumour Spheroids ◽  
Current Therapies

Sarcomas are tumours of mesenchymal origin, which can arise in bone or soft tissues. They are rare but frequently quite aggressive and with a poor outcome. New approaches are needed to characterise these tumours and their resistance mechanisms to current therapies, responsible for tumour recurrence and treatment failure. This review is focused on the potential of three-dimensional (3D) in vitro models, including multicellular tumour spheroids (MCTS) and organoids, and the latest data about their utility for the study on important properties for tumour development. The use of spheroids as a particularly valuable alternative for compound high throughput screening (HTS) in different areas of cancer biology is also discussed, which enables the identification of new therapeutic opportunities in commonly resistant tumours.

scholarly journals A computational framework for modeling cell–matrix interactions in soft biological tissues

2021 ◽  
Author(s):  
Jonas F. Eichinger ◽  
Maximilian J. Grill ◽  
Iman Davoodi Kermani ◽  
Roland C. Aydin ◽  
Wolfgang A. Wall ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Three Dimensional ◽  
Biological Tissues ◽  
Computational Framework ◽  
Cell Matrix ◽  
Physiological Processes ◽  
Matrix Interactions ◽  
Mechanical Homeostasis ◽  
Cell Matrix Interactions ◽  
Short Time

AbstractLiving soft tissues appear to promote the development and maintenance of a preferred mechanical state within a defined tolerance around a so-called set point. This phenomenon is often referred to as mechanical homeostasis. In contradiction to the prominent role of mechanical homeostasis in various (patho)physiological processes, its underlying micromechanical mechanisms acting on the level of individual cells and fibers remain poorly understood, especially how these mechanisms on the microscale lead to what we macroscopically call mechanical homeostasis. Here, we present a novel computational framework based on the finite element method that is constructed bottom up, that is, it models key mechanobiological mechanisms such as actin cytoskeleton contraction and molecular clutch behavior of individual cells interacting with a reconstructed three-dimensional extracellular fiber matrix. The framework reproduces many experimental observations regarding mechanical homeostasis on short time scales (hours), in which the deposition and degradation of extracellular matrix can largely be neglected. This model can serve as a systematic tool for future in silico studies of the origin of the numerous still unexplained experimental observations about mechanical homeostasis.

scholarly journals The Symmetric 3D Organization of Connective Tissue around Implant Abutment: A Key-Issue to Prevent Bone Resorption

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1126
Author(s):  
Giovanna Iezzi ◽  
Francesca Di Lillo ◽  
Michele Furlani ◽  
Marco Degidi ◽  
Adriano Piattelli ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Connective Tissue ◽  
Inflammatory Cell ◽  
Soft Tissues ◽  
Three Dimensional ◽  
Collagen Fibers ◽  
Inflammatory Cell Infiltration ◽  
Cell Infiltration ◽  
Oral Epithelium ◽  
Implant Abutment

Symmetric and well-organized connective tissues around the longitudinal implant axis were hypothesized to decrease early bone resorption by reducing inflammatory cell infiltration. Previous studies that referred to the connective tissue around implant and abutments were based on two-dimensional investigations; however, only advanced three-dimensional characterizations could evidence the organization of connective tissue microarchitecture in the attempt of finding new strategies to reduce inflammatory cell infiltration. We retrieved three implants with a cone morse implant–abutment connection from patients; they were investigated by high-resolution X-ray phase-contrast microtomography, cross-linking the obtained information with histologic results. We observed transverse and longitudinal orientated collagen bundles intertwining with each other. In the longitudinal planes, it was observed that the closer the fiber bundles were to the implant, the more symmetric and regular their course was. The transverse bundles of collagen fibers were observed as semicircular, intersecting in the lamina propria of the mucosa and ending in the oral epithelium. No collagen fibers were found radial to the implant surface. This intertwining three-dimensional pattern seems to favor the stabilization of the soft tissues around the implants, preventing inflammatory cell apical migration and, consequently, preventing bone resorption and implant failure. This fact, according to the authors’ best knowledge, has never been reported in the literature and might be due to the physical forces acting on fibroblasts and on the collagen produced by the fibroblasts themselves, in areas close to the implant and to the symmetric geometry of the implant itself.

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