An overview of vertebrate mineralization with emphasis on collagen-mineral interaction.
Humans; Animals; Gene Expression; Chick Embryo; Osteocalcin/genetics/metabolism; *Gravitation; *Space Flight; *Weightlessness; Bone and Bones/cytology/metabolism/physiology/ultrastructure; Collagen/genetics/*metabolism/ultrastructure; Crystallization; NASA Discipline Musculoskeletal; Non-NASA Center; Osteoblasts/metabolism; Tendons/cytology/metabolism/*physiology/ultrastructure; Tomography; Calcification; Physiologic/*physiology
The nucleation, growth, and development of mineral crystals through their interaction principally with collagen in normal bone and calcifying tendon have been elaborated by applying a number of different techniques for analysis of the inorganic and organic constituents of these tissues. The methods have included conventional and high voltage electron microscopy, electron diffraction, microscopic tomography and 3D image reconstruction, and atomic force microscopy. This summary presents results of these studies that have now characterized the size, shape, and aspects of the chemical nature of the crystals as well as their orientation, alignment, location, and distribution with respect to collagen. These data have provided the means for understanding more completely the formation and strength of the collagen-mineral composite present in most vertebrate calcifying tissues and, from that information, a basis for the adaptation of such tissues under mechanical constraints. In the context of the latter point, other data are given showing effects on collagen in bone cell cultures subjected to the unloading parameters of spaceflight. Implications of these results may be particularly relevant to explaining loss of bone by humans and other vertebrate animals during missions in space, during situations of extended fracture healing, long-term bedrest, physical immobilization, and related conditions. In a broader sense, the data speak to the response of bone and mineralized vertebrate tissues to changes in gravitational loading and applied mechanical forces in general.
Landis W J
Gravitational and space biology bulletin : publication of the American Society for Gravitational and Space Biology
1999
1999-05
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
Neonatal glycine encephalopathy: biochemical and neuropathologic findings.
Adolescent; Amino Acid Metabolism; Amino Acids/blood; Brain Diseases; Brain/pathology; Calcium Oxalate/blood; Child; Crystallization; Follow-Up Studies; Glycine/*blood; Humans; Inborn Errors/genetics/*pathology; Infant; Male; Metabolic/genetics/*pathology; Myelin Sheath/*pathology; Newborn; Preschool; Spinal Cord/pathology
A patient with neonatal glycine encephalopathy who had severe neurologic retardation, spasticity, and seizures died at 17 years of age. Glycine concentration was markedly elevated in brain tissue, especially in the cerebellum. Neuropathologic study revealed spongy myelinopathy throughout the central nervous system and calcium oxalate crystals in the cerebellum, which are probably derived from degradation of glycine. Myelinopathy appeared to be static compared to neonatal patients. The neurologic manifestations of neonatal glycine encephalopathy are probably due to neurotransmitter abnormalities, not to myelin damage.
Agamanolis D P; Potter J L; Lundgren D W
Pediatric neurology
1993
1993-04
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1016/0887-8994(93)90051-d" target="_blank" rel="noreferrer noopener">10.1016/0887-8994(93)90051-d</a>