No abstract available.
Osteoblasts*

No abstract available.
Osteoblasts*

Within the past few years, information regarding osteocyte function as been emerging and expanding significantly. No longer is the osteocyte considered a passive cell acting simply as a 'placeholder' within mineralized bone. Osteocytes are derived from osteoblast progenitors and in the adult skeleton compose 90-95% of all bone cells. Therefore, the function of these cells in the adult and aging skeleton has become the focus of recent investigation. These cells are proving to be multifunctional, ranging from mechanotransduction, to regulation of mineral homeostasis, to control of bone remodeling. The osteocyte as a source and reservoir of signaling factors important in health and maintenance of the adult skeleton is addressed in this review.
Adult ; Aging ; Bone Remodeling ; Homeostasis ; Humans ; Osteoblasts ; Osteocytes ; Skeleton

The aim of this study was to investigate the role of osteal macrophages (osteomac) and osteocytes in bone remodeling using a mathematical model. We constructed the bone system with pre-osteoblasts, osteoclasts, osteocytes, and osteomac. Each link of the parameters and ordinary differential equations followed the Graham's model in 2013 except for the parameters of osteomac signaling and osteocytes signaling to link preosteoblasts and osteoblasts. We simulated the changes in each cell and bone volume according to the changes in the parameters of osteomac signaling and osteocytes signaling. The results showed bone volume was unstable and decreased gradually when the effectiveness of osteocytes and osteomac dropped below a certain level. When the parameters of osteomac signaling and osteocytes signaling to link preosteoblasts and osteoblasts had a value less than 1, bone volume increased with the increase in the parameter of osteomac signaling to link preosteoblasts and osteoblasts. Moreover, although the parameter of osteocytes signaling to link preosteoblasts and osteoblasts, increased in case of a small parameter of osteomac signaling, bone volulme decreased. If the parameters of osteomac signaling to link preosteoblasts and osteoblasts were over a certain level, bone volume was positively maintained, despite the parameter of osteocyte signaling to link preosteoblasts and osteoblasts. We suggested the osteomac may affect bone remodeling and may play an important role in bone cell network.
Bone and Bones* ; Bone Remodeling ; Macrophages* ; Models, Theoretical* ; Osteoblasts ; Osteoclasts ; Osteocytes*

Glucocorticoids* ; Osteoblasts*

No abstract available.
Fluorides* ; Osteoblasts*

Osteoma cutis is an infrequent primary ossification arising in the dermis or subcutaneous fat tissue without preceding trauma, skin disease or evidence of Albright's hereditary osteodystrophy. We report a case of osteoma cutis in a 12-year-old female, who had had a 1x1cm sized, asymptomatic, round, skin-coloured, hard nodule on her left forearm for 7 years. The history and physical examinations failed to reveal any sign of secondary cutaneous ossification, due to inflammation, scars and dysembryoplastia. Histologically, the lesion showed bony structures with osteocytes and osteoblasts in the subcutaneous fat tissue.
Child ; Cicatrix ; Dermis ; Female ; Forearm ; Humans ; Inflammation ; Osteoblasts ; Osteocytes ; Osteoma* ; Physical Examination ; Skin Diseases ; Subcutaneous Fat

Bone morphogenetic protein-2/4 are members of Transforming Growth Factor-beta(TGF-beta) superfamily and they may induce formation of cartilage and bone in vivo. This study was performed to investigate the cellular target and period of action of BMP-2/4 and understanding of actions of BMP-2/4 at cellular level. The appearance of BMP-2/4 during healing of mandibular and periodontal defect in rat was evaluated immunohistochemically. 40 Sprague-Dawley strain white male rats, each weighing about 300gm were used. Bony defect was performed in the mandible and they were sacrificed at the day of 3rd, 10th, 20th, 30th after operation. The specimens were harvested and examined histologically and immunohistochemically by localization of anti-BMP-2/4. The results were as follows: 1. Woven bone was observed at 10th day and perfect healing of defect with compact bone and periodontal ligment space at 30th day. 2. Osteoprogenitor cells, osteoblastic cells and periosteum were positive reaction to immunohistochemical stain at 10th day. 3. Cells of bone marrow space and surface cells of osteocytes and cementoblasts were positive reaction to immunohistochemical stain at 20th day. 4. Newly formed osteocytes and cementocytes were positive reaction to immunohistochemical stain at 30th day. From the above findings, we could conclude that BMP-2/4 acted significant roles as factors of induction, proliferation and differentiation during bone healing process.
Animals ; Bone Marrow ; Cartilage ; Dental Cementum ; Humans ; Male ; Mandible ; Osteoblasts ; Osteocytes ; Periosteum ; Rats* ; Rats, Sprague-Dawley

Osteoma cutis was first described by Wilkins in 1858 and it is a primary cutaneous ossification, which has no preceding trauma or skin disease and no evidence of Albright's hereditary osteodysttophy in the patient or his family. The lesions appear as hard, round to irregular, sharply defined tumors of varying size within the dermis or subcutis, and their color range from red to purple or brown. We report a rare case of multiple osteoma cutis in an infant. A 10-month-old female infant presented with multiple hard purplish nodules on the abdomen for several months and did not show any evidence of Albright's hereditary osteodystrophy and signs of secondary cutaneous ossification such as trauma, injection, and previous skin lesions. The histopathologic finding shows intradermal bony spicules with numerous osteocytes, cement lines, osteoblasts, and osteoclasts.
Abdomen ; Dermis ; Female ; Humans ; Infant* ; Osteoblasts ; Osteoclasts ; Osteocytes ; Osteoma* ; Skin ; Skin Diseases

Nevus cell nevus in bone has been called osteo-nevus of Nanta since Nanta reported it in detail in 1911. We report a 46-year-old female patient with osteo-nevus of Nanta on her forehead. Histologic examination revealed nests of nevus cells, with numerous osteocytes and osteoblasts in the bony tissue. Inflammatory cell infiltrate and foreign body granuloma were not found.
Female ; Forehead ; Granuloma, Foreign-Body ; Humans ; Middle Aged ; Nevus ; Osteoblasts ; Osteocytes