A man aged 40 years showed radiographic changes in the form of generalized increased bone density and patchy rarefaction. Urinary calcium was increased and serum alkaline phosphatase was elevated; serum calcium and phosphate levels were normal. Multiple fractures developed. At autopsy, all parts of the skeleton showed partial replacement of bone and bone marrow by a tissue deficient in collagen fibers. Much of this tissue was unmineralized, but lesions in cortical bone showed hypermineralization on microradiographic examination. Electron microscopy showed replacement of collagen fibers by amorphous material in the affected areas. Electron probe analysis showed a normal Ca:P ratio for bone mineral in the hypermineralized areas.
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http://dx.doi.org/10.1016/s8756-3282(00)00401-4 | DOI Listing |
Development
January 2025
School of Science, Technische Universität Dresden, 01062 Dresden, Germany.
The elongation of tissues and organs is important for proper morphogenesis in animal development. In Drosophila ovaries, the elongation of egg chambers involves aligned Collagen IV fiber-like structures, a gradient of extracellular matrix stiffness and actin-based protrusion-driven collective cell migration, leading to the rotation of the egg chamber. Egg chamber elongation and rotation depend on the atypical cadherin Fat2.
View Article and Find Full Text PDFJ Anat
January 2025
Bonn Institute of Organismal Biology, Paleontology, University of Bonn, Bonn, Germany.
Current understanding of the histology of the dermoskeleton of tetrapods comes from fossilized and recent remains of skulls, osteoderms, carapace, plastron and other postcranial material which were always investigated using linear cross polarized light (LCPL) microscopy. The pectoral girdle of vast majority of non-amniote tetrapods, including temnospondyls evolved large ventrally located dermal bones- the interclavicle and a pair of clavicles. Despite that, there is a lack of information about the bone tissue structure from these postcranial dermal bones.
View Article and Find Full Text PDFFolia Morphol (Warsz)
January 2025
Department of Human Morphology and Embryology, Division of Anatomy, Wroclaw Medical University, Wrocław, Poland.
The correct function of the upper limb depends on the cooperation and coordination of the muscular and skeletal systems as well as the connective tissue elements present in it. Connective tissue forms fascia, connective tissue membranes and ligaments. Connective tissue mostly develops from the mesenchyme.
View Article and Find Full Text PDFiScience
January 2025
Abteilung Paläontologie, Bonner Institut für Organismische Biologie, Universität Bonn, 53115 Bonn, Germany.
Bone is formed by specialized cells whose activity allows bone to grow, change shape, and repair itself. Its composite structure of collagen fibrils and bioapatite nanocrystals gives bone exceptional mechanical strength. Using scanning electron microscopy, we show in fossil ichthyosaurs, 150 to 200 million years old, from the Jurassic of France and the UK, abundant and direct evidence of cellular activity on the fossilized forming, resting, and resorbing surfaces of bone trabeculae, as well as bone fibrils, Sharpey fibers, and cartilage fibers.
View Article and Find Full Text PDFHeliyon
July 2024
Department of Cardiovascular Surgery, First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China.
Recent studies have attempted to characterize the layer-specific mechanical and microstructural properties of the aortic tissues in either normal or pathological state to understand its structural-mechanical property relationships. However, layer-specific tissue mechanics and compositions of normal and dissected ascending aortas have not been thoroughly compared with a statistical conclusion obtained. Eighteen ascending aortic specimens were harvested from 13 patients with type A aortic dissection and 5 donors without aortic diseases, with each specimen further excised to obtain three tissue samples including an intact wall, an intima-media layer and an adventitia layer.
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