Bone Density ; physiology ; Bone Development ; physiology ; Bone and Bones ; diagnostic imaging ; Child ; Humans ; Nutrition Assessment ; Ultrasonography

Animals ; Biomechanical Phenomena ; Bone Development ; Bone Remodeling ; Bone and Bones ; injuries ; Fracture Healing ; physiology ; Fractures, Bone ; pathology

Animals ; Bone and Bones ; metabolism ; Energy Metabolism ; physiology ; Humans ; Osteocalcin ; metabolism

This paper introduces the development on the research of measuring theory for orthopaedic biomechanics in detail. Then, the measuring method and corresponding measuring device are also mentioned. Advantages, disadvantages and development for the device are also introduced. Finally, the research prospect for it is introduced.
Biomechanical Phenomena ; Bone and Bones ; physiology ; physiopathology ; Physics ; instrumentation ; methods

Tunneling nanotube (TNT) is a newly discovered communication mode between animal cells in recent years, which have important physiological and pathological significance. However, the role of TNT in bone biology is still unclear. At present, there are many reports about tunneling nanotubes in bone marrow mesenchymal stem cells, osteoclast precursor cells, osteoblasts and immune cells. This review describes the research advances of TNT and its research progress in bone biology. It looks forward to the research direction of TNT in oral and maxillofacial bone development and bone biology, to provide new strategies for the maintenance of bone homeostasis and the treatment of bone diseases.
Animals ; Bone and Bones ; Nanotubes ; Osteoclasts ; Biology ; Cell Communication/physiology*

No abstract available.
Animal ; Bone and Bones/blood supply* ; Bone and Bones/innervation ; Bone and Bones/physiology ; Comparative Study ; Dogs ; Human ; Joints/blood supply* ; Joints/innervation ; Joints/physiology ; Muscle Contraction ; Oxygen Consumption ; Rabbits ; Rats

At present, the numerical model of bone remodeling is inadequate to copy the physiological process of bone remodeling. According to the physiological mechanism of bone remodeling and the anisotropy of bone mechanics properties, an anisotropic bone modeling model with mechanostat was developed, and then was applied to a study on the remodeling evolution of 2D squareplate model. Good results were obtained. The model can be used in the study of implant, osteoporosis and other bone diseases.
Anisotropy ; Biomechanical Phenomena ; Bone Remodeling ; physiology ; Bone and Bones ; physiology ; Models, Biological ; Osteoporosis ; physiopathology

OBJECTIVEUsing MR T2-mapping and histopathologic score for articular cartilage to evaluate the effect of structural changes in subchondral bone on articular cartilage.

METHODSTwenty-four male Beagle dogs were randomly divided into a subchondral bone defect group (n = 12) and a bone cement group (n = 12). Models of subchondral bone defectin the medial tibial plateau and subchondral bone filled with bone cement were constructed. In all dogs, the left knee joint was used as the experimental sideand the right knee as the sham side. The T2 value for articular cartilage at the medial tibial plateau was measured at postoperative weeks 4, 8, 16, and 24. The articular cartilage specimens were stained with hematoxylin and eosin, and evaluated using the Mankin score.

RESULTSThere was a statistically significant difference (P < 0.05) in Mankin score between the bone defect group and the cement group at postoperative weeks 16 and 24. There was a statistically significant difference in the T2 values between the bone defect group and its sham group (P < 0.05) from week 8, and between the cement group and its sham group (P < 0.05) from week 16. There was significant difference in T2 values between the two experimental groups at postoperative week 24 (P < 0.01). The T2 value for articular cartilage was positively correlated with the Mankin score (ρ = 0.758, P < 0.01).

CONCLUSIONStructural changes in subchondral bone can lead to degeneration of the adjacent articular cartilage. Defects in subchondral bone cause more severe degeneration of cartilage than subchondral bone filled with cement. The T2 value for articular cartilage increases with the extent of degeneration. MR T2-mapping images and the T2 value for articular cartilage can indicate earlycartilage degeneration.

Distraction osteogenesis (DO) is widely used for bone tissue engineering technology. Immune regulations play important roles in the process of DO like other bone regeneration mechanisms. Compared with others, the immune regulation processes of DO have their distinct features. In this review, we summarized the immune-related events including changes in and effects of immune cells, immune-related cytokines, and signaling pathways at different periods in the process of DO. We aim to elucidated our understanding and unknowns about the immunomodulatory role of DO. The goal of this is to use the known knowledge to further modify existing methods of DO, and to develop novel DO strategies in our unknown areas through more detailed studies of the work we have done.
Bone Regeneration/physiology* ; Bone and Bones ; Osteogenesis/physiology* ; Osteogenesis, Distraction/methods* ; Tissue Engineering

Weight-bearing bone is constantly adapting its structure and function to mechanical environments. Loading through routine exercises stimulates bone formation and prevents bone loss, but unloading through bed rest and cast immobilization as well as exposure to weightlessness during spaceflight reduces its mass and strength. In order to elucidate the mechanism underlying unloading-driven bone adaptation, ground-based in vitro and in vivo analyses have been conducted using rotating cell culturing and hindlimb suspension. Focusing on gene expression studies in osteoblasts and hindlimb suspension studies, this minireview introduces our recent understanding on bone homeostasis under weightlessness in space. Most of the existing data indicate that unloading has the opposite effects to loading through common signaling pathways. However, a question remains as to whether any pathway unique to unloading (and not to loading) may exist.
Adaptation, Physiological ; Animals ; Bone and Bones ; cytology ; physiology ; Hindlimb Suspension ; physiology ; Humans ; Osteoblasts ; physiology ; Weightlessness