Non-destructive studies of tissue-engineered phalanges by magnetic resonance microscopy and X-ray microtomography
bone; bone-mineral density; cartilage; computed-tomography; computed-tomography; Endocrinology & Metabolism; in-vivo; macromolecules; magnetic resonance microscopy; microct; mr; quantitative; relaxation; scaffolds; tissue engineering; trabecular bone; X-ray microtomography
One of the intents of tissue engineering is to fabricate biological materials for the augmentation or replacement of impaired, damaged, or diseased human tissue. In this context, novel models of the human phalanges have been developed recently through suturing of polymer scaffolds supporting osteoblasts, chondrocytes, and tenocytes to mimic bone, cartilage, and tendon, respectively. Characterization of the model constructs has been accomplished previously through histological and biochemical means, both of which are necessarily destructive to the constructs. This report describes the application of two complementary, non-destructive, non-invasive techniques, magnetic resonance microscopy (MRM) and X-ray microtomography (XMT or quantitative computed tomography), to evaluate the spatial and temporal growth and developmental status of tissue elements within tissue-engineered constructs obtained after 10 and 38 weeks of implantation in athymic (nude) mice. These two times represent respective points at which model middle phalanges are comprised principally of organic components while being largely unmineralized and later become increasingly more mineralized. The spatial distribution of mineralized deposits within intact constructs was readily detected by XMT (qCT) and was comparable to low intensity zones observed on MRM hydration maps. Moreover, the MRM-derived hydration values for mineralized zones were inversely correlated with mineral densities measured by XMT. In addition, the MRM method successfully mapped fat deposits, collagenous tissues, and the hydration state of the soft tissue elements comprising the specimens. These results support the application of non-destructive, non-invasive, quantitative MRM and XMT for the evaluation of constituent tissue elements within complex constructs of engineered implants. (c) 2005 Elsevier Inc. All rights reserved.
Potter K; Sweet D E; Anderson P; Davis G R; Isogai N; Asamura S; Kusuhara H; Landis W J
Bone
2006
2006-03
Journal Article
<a href="http://doi.org/10.1016/j.bone.2005.08.025" target="_blank" rel="noreferrer noopener">10.1016/j.bone.2005.08.025</a>
Flight feather attachment in rock pigeons (Columba livia): covert feathers and smooth muscle coordinate a morphing wing.
*avian; *covert feathers; *flight feathers; *quill knobs; *smooth muscle; *wing shape; Animal/*anatomy & histology; Animal/*physiology; Animals; Bone and Bones/anatomy & histology; Columbidae/*anatomy & histology; Feathers/*anatomy & histology; Flight; Muscle; Smooth/*anatomy & histology; Wings; X-Ray Microtomography
Mechanisms for passively coordinating forelimb movements and flight feather abduction and adduction have been described separately from both in vivo and ex vivo studies. Skeletal coordination has been identified as a way for birds to simplify the neuromotor task of controlling flight stroke, but an understanding of the relationship between skeletal coordination and the coordination of the aerodynamic control surface (the flight feathers) has been slow to materialize. This break between the biomechanical and aerodynamic approaches - between skeletal kinematics and airfoil shape - has hindered the study of dynamic flight behaviors. Here I use dissection and histology to identify previously overlooked interconnections between musculoskeletal elements and flight feathers. Many of these structures are well-placed to directly link elements of the passive musculoskeletal coordination system with flight feather movements. Small bundles of smooth muscle form prominent connections between upper forearm coverts (deck feathers) and the ulna, as well as the majority of interconnections between major flight feathers of the hand. Abundant smooth muscle may play a role in efficient maintenance of folded wing posture, and may also provide an autonomically regulated means of tuning wing shape and aeroelastic behavior in flight. The pattern of muscular and ligamentous linkages of flight feathers to underlying muscle and bone may provide predictable passive guidance for the shape of the airfoil during flight stroke. The structures described here provide an anatomical touchstone for in vivo experimental tests of wing surface coordination in an extensively researched avian model species.
Hieronymus Tobin L
Journal of anatomy
2016
2016-11
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/10.1111/joa.12511" target="_blank" rel="noreferrer noopener">10.1111/joa.12511</a>
Mutation in Osteoactivin Promotes Receptor Activator of NFkappaB Ligand (RANKL)-mediated Osteoclast Differentiation and Survival but Inhibits Osteoclast Function.
*Mutation; Akt; Animals; bone; bone marrow; Bone Remodeling; Cell Differentiation/*physiology; Cell Survival/*physiology; Eye Proteins/*genetics; Inbred DBA; MAP kinases (MAPKs); Membrane Glycoproteins/*genetics; Mice; osteoactivin; osteoclast; Osteoclasts/*cytology; osteopetrosis; RANK Ligand/metabolism/*physiology; Signal Transduction; X-Ray Microtomography
We previously reported on the importance of osteoactivin (OA/Gpnmb) in osteogenesis. In this study, we examined the role of OA in osteoclastogenesis, using mice with a nonsense mutation in the Gpnmb gene (D2J) and wild-type controls (D2J/Gpnmb(+)). In these D2J mice, micro-computed tomography and histomorphometric analyses revealed increased cortical thickness, whereas total porosity and eroded surface were significantly reduced in D2J mice compared with wild-type controls, and these results were corroborated by lower serum levels of
Abdelmagid Samir M; Sondag Gregory R; Moussa Fouad M; Belcher Joyce Y; Yu Bing; Stinnett Hilary; Novak Kimberly; Mbimba Thomas; Khol Matthew; Hankenson Kurt D; Malcuit Christopher; Safadi Fayez F
The Journal of biological chemistry
2015
2015-08
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/10.1074/jbc.M114.624270" target="_blank" rel="noreferrer noopener">10.1074/jbc.M114.624270</a>