COVID-19 Online Health Monitoring System to Support Municipal Health Centers.

An online health-monitoring system for COVID-19-infected patients who are staying in hotels and homes was developed using geographical information systems. This system provides display functions for sending health observation forms to infected residents, scoring for medical risk assessment, and centralized management. More than 1,146,000 health observation records were registered in November 2022, and the system contributed to maintaining the functionality of the municipal health center in Sapporo, Japan.

Minodronic acid induces morphological changes in osteoclasts at bone resorption sites and reaches a level required for antagonism of purinergic P2X2/3 receptors.

Minodronic acid is an aminobisphosphonate that is an antagonist of purinergic P2X2/3 receptors involved in pain. The aim of this study was to investigate the action and distribution of minodronic acid and the potential for P2X2/3 receptor antagonism based on the estimated concentration of minodronic acid. Microlocalization of radiolabeled minodronic acid was examined in the femur of neonatal rats.

Matrix remodeling and cytological changes during spontaneous cartilage repair.

During the repair of articular cartilage, type I collagen (COL1)-based fibrous tissues change into a mixture of COL1 and type II collagen (COL2) and finally form hyaline cartilaginous tissues consisting of COL2. In order to elucidate the changes that occur in the matrix during cartilage repair and the roles of fibroblasts and chondrocytes in this process, we generated a minimal cartilage defect model that could be spontaneously repaired. Defects of 0.

Carbon nanotubes induce bone calcification by bidirectional interaction with osteoblasts.

Multi-walled carbon nanotubes (MWCNTs) promote calcification during hydroxyapatite (HA) formation by osteoblasts. Primary cultured osteoblasts are incubated with MWCNTs or carbon black. After culture for 3 weeks, the degree of calcification is very high in the 50 μg mL(-1) MWCNT group.

Histology of epiphyseal cartilage calcification and endochondral ossification.

Cartilage calcification is carried out by chondrocytes as they hypertrophy and begin to secrete matrix vesicles. Calcification initiates when calcium phosphates appear inside these matrix vesicles, forming hydroxyapatite crystals that eventually break through the membrane to form calcifying globules, as in bone calcification. However, the extracellular environment in cartilage is different from that in bone: cartilage is abundant in proteoglycans but contains a small amount of osteopontin.

Polarized osteoclasts put marks of tartrate-resistant acid phosphatase on dentin slices--a simple method for identifying polarized osteoclasts.

Osteoclasts form ruffled borders and sealing zones toward bone surfaces to resorb bone. Sealing zones are defined as ringed structures of F-actin dots (actin rings). Polarized osteoclasts secrete protons to bone surfaces via vacuolar proton ATPase through ruffled borders.

Harmine, a β-carboline alkaloid, inhibits osteoclast differentiation and bone resorption in vitro and in vivo.

Bone homeostasis is controlled by the balance between osteoblastic bone formation and osteoclastic bone resorption. Excessive bone resorption is involved in the pathogenesis of bone-related disorders such as osteoporosis, arthritis and periodontitis. To obtain new antiresorptive agents, we searched for natural compounds that can inhibit osteoclast differentiation and function.

Prostaglandin E(2) receptor EP(4)-selective agonist (ONO-4819) increases bone formation by modulating mesenchymal cell differentiation.

Prostaglandin E(2) (PGE(2)) positively regulates bone resorption and formation mainly mediated through the EP(4) receptor, a subtype of PGE(2) receptors. ONO-4819, an EP(4) receptor-selective agonist, has been shown to increase bone volume, density, and strength; however, the mechanism of these effects has yet to be fully elucidated. To explore this matter, ONO-4819 (10μg/kg) was injected into intact rats twice a day for 5weeks, and their bones were then analyzed by morphological techniques.

Localization of Thy-1-positive cells in the perichondrium during endochondral ossification.

We elucidated the localization of Thy-1-positive cells in the perichondrium of fetal rat limb bones to clarify the distribution of osteogenic cells in the process of endochondral ossification. We also examined the formation of calcified bone-like matrices by isolated perichondrial cells in vitro. At embryonic day (E) 15.

The relationship between calcium accumulation in osteoclast mitochondrial granules and bone resorption.

In the process of bone resorption, calcium is considered to be transported within vesicles in osteoclasts and eventually released. We studied the ultramicromorphology of calcium (Ca) transport in osteoclasts by preparing samples of osteoclasts collected from rat femurs in which calcium was maximally preserved and subjected them to high-pressure quick-freezing and freeze-substitution. We then examined the localization of calcium by Electron Energy Loss Spectroscopy (EELS).

Multiwalled carbon nanotubes specifically inhibit osteoclast differentiation and function.

Since attention has been paid to the use of multiwalled carbon nanotubes (MWCNTs) as biomaterials in contact with bone, it is critical to understand the reaction of bone cells to MWCNTs. We show that MWCNTs inhibit osteoclastic bone resorption in vivo and that MWCNTs inhibit osteoclastic differentiation and suppressed a transcription factor essential for osteoclastogenesis in vitro. These results suggest that MWCNTs have beneficial effects on bones when they are used as biomaterials.

Involvement of cell-cell and cell-matrix interactions in bone destruction induced by metastatic MDA-MB-231 human breast cancer cells in nude mice.

To clarify the mechanisms of bone destruction associated with bone metastases, we studied an animal model in which inoculation of MDA-MB-231 human breast cancer cells into the left cardiac ventricle of female nude mice causes osteolytic lesions in bone using morphological techniques. On the bone surfaces facing the metastatic tumor cells, there existed many tartrate-resistant acid phosphatase (TRAP)-positive multinucleated osteoclasts. TRAP-positive mononuclear osteoclast precursor cells were also observed in the tumor nests.

Alveolar bone regeneration of subcutaneously transplanted rat molar.

Regeneration of alveolar bone is essential for periodontal treatment. Recently, cell replacement therapy has been focused on periodontal disease, but the source of the cells that regenerate alveolar bone is still uncertain. Therefore, to clarify the source of these bone-regenerating cells, we transplanted GFP-transgenic rat molars into the subcutaneous tissues of wild-type rats.

Histological assessments on the abnormalities of mouse epiphyseal chondrocytes with short term centrifugal loading.

We have examined the morphological changes in chondrocytes after exposure to experimental hypergravity. Tibial epiphyseal cartilages of 17-days-old mouse fetuses were exposed to centrifugation at 3G for 16 h mimicking hypergravitational environment (experimental group), or subjected to stationary cultures (control group). Centrifugation did not affect the sizes of epiphyseal cartilage, chondrocyte proliferation, type X collagen-positive hypertrophic zone, and the mRNA expressions of parathyroid hormone-related peptide and fibroblast growth factor receptor III.

Regulation of osteoclast polarization.

Osteoclast function consists of several processes: recognition of mineralized tissues, development of ruffled borders and sealing zones, secretion of acids and proteolytic enzymes into the space beneath the ruffled border, and incorporation and secretion of bone degradation products using the transcytosis system. One of the most important questions concerning osteoclast function is how osteoclasts recognize bone and polarize. During the past decade, new approaches have been taken to investigate the regulation of osteoclast polarization.

Association of TIMP-2 with extracellular matrix exposed to mechanical stress and its co-distribution with periostin during mouse mandible development.

Matrix remodeling is regulated by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). Periostin, originally identified in a mouse osteoblastic library, plays a role in cell adhesion and migration and in mechanical stress-induced matrix remodeling. In this study, we analyzed and compared the distribution patterns of TIMP-2 and periostin during mouse mandible development.

Immunohistochemical study of hard tissue formation in the rat pulp cavity after tooth replantation.

While mineralized tissue is formed in the pulp cavity after tooth replantation or transplantation, little is known of this hard tissue formation. Therefore, we conducted histological and immunohistochemical evaluations of hard tissue formed in the pulp of rat maxillary molars after tooth replantation. At 5 days after replantation, degenerated odontoblasts were lining the pulp cavity.

Histomorphometric study on the effects of age on orthodontic tooth movement and alveolar bone turnover in rats.

The aim of this study was to investigate, in a rat model, the effects of age on the amount of tooth movement and concomitant changes in alveolar bone turnover activity adjacent to orthodontically treated tooth roots. Rats (n = 48) of four different age groups (10, 30, 50, and 80 wk of age) were used in the experiment. Maxillary first molars were tipped mesially with a nickel titanium alloy coil-spring for 2 wk by a continuous force of 10 cN.

Effect of age on alveolar bone turnover adjacent to maxillary molar roots in male rats: A histomorphometric study.

Objective: The effect of age on alveolar bone turnover adjacent to maxillary molar roots of male rats was assessed histomorphometrically with special focus on bone formation and resorption.

Design: A total of 110 male Wistar rats ranging in age from 6 to 100 weeks were used for this study. Histomorphometric parameters were measured in fluorescence-labeled undecalcified ground and paraffin-embedded decalcified sections of the alveolar wall around the disto-lingual roots of the maxillary first molars.

New 19-nor-(20S)-1alpha,25-dihydroxyvitamin D3 analogs strongly stimulate osteoclast formation both in vivo and in vitro.

2-Methylene-19-nor-(20S)-1alpha,25-dihydroxyvitamin D3 (2MD), an analog of 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3], has been shown to strongly induce bone formation both in vitro and in vivo. We have synthesized four substituents at carbon 2 of 2MD (2MD analogs), four stereoisomers at carbon 20 of the respective 2MD analogs (2MD analog-C20 isomers) and four 2MD analogs with an oxygen atom at carbon 22 (2MD-22-oxa analogs) and examined their ability to stimulate osteoclastogenesis and induce hypercalcemia. 2MD analogs were 100 times as potent as 1alpha,25(OH)2D3 in stimulating the formation of osteoclasts in vitro and in inducing the expression of receptor activator of NF-kappaB ligand (RANKL) and 25-hydroxyvitamin D3-24 hydroxylase mRNAs in osteoblasts.

Increase of bone volume by a nanosecond pulsed laser irradiation is caused by a decreased osteoclast number and an activated osteoblasts.

The biostimulatory effects of laser irradiation focus not only in the field of soft tissue but also bone formation. Studies have shown that the light of a nanosecond pulsed laser which has a high peak power can produce stress waves in tissue. We have hypothesized that nanosecond pulsed laser irradiation stimulates bone formation.