IL-4 inhibits tooth movement and prevents root resorption in the mouse model. These results suggest that IL-4 could be used as a useful adjunct to regulate the extent of OTM and also to control root resorption.

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Mechanical loading exerts important effects on the skeleton by controlling bone mass and strength. Osteoclasts are required for bone resorption and remodeling. Two cytokines are required for osteoclast formation: macrophage colony-stimulating factor and receptor activator of nuclear factor kappa-B ligand (RANKL). Tumor necrosis factor-α (TNF-α) has also been recognized as an important factor for osteoclastogenesis. It has previously been reported that interleukin (IL)-12 and IL-18, and interferon gamma (IFN-γ), which are type 1T helper cell (Th1) cytokines, inhibited RANKL-and TNF-α-mediated osteoclastogenesis. It also been reported that TNF-α plays an important role in mechanical loadinginduced osteoclastogenesis and bone resorption. Orthodontic tooth movement is a good model for exploring the mechanism underlying mechanical loading-induced bone changes. Orthodontic tooth movement in a mouse model was established, and we investigated whether Th1 cytokines such as IL-12 and IFN-γ inhibit osteoclastogenesis and bone resorption upon mechanical loading. The number of tartrateresistant acid phosphatase (TRAP)-positive cells increased at the pressure side of the first molar. Conversely, the amount of tooth movement and the number of TRAP-positive cells at the pressure side in IL-12-and IFN-γ-injected mice was less than that of non-injected mice. The results suggested that IL-12 and IFN-γ might have an inhibitory effect on mechanical loading-induced osteoclastogenesis. In this review, we describe and discuss the effect of Th1 cytokines on mechanical loadinginduced osteoclastogenesis and bone resorption.

Lipopolysaccharide (LPS) is a major component of Gram-negative bacteria cell walls and is a well-known potent inducer of inflammation and pathogens of inflammatory bone loss. Formation of osteoclasts is highly dependent on the presence of macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor kappa-B ligand (RANKL). Recent reports indicate that biological preparations, including anti-RANKL antibody and anti-tumor necrosis factor-α antibody, positively influence rheumatoid arthritis and osteoporosis. In this study, we aimed to investigate whether the M-CSF receptor c-Fms antibody would inhibit the formation of osteoclasts. C57BL6/J mice were injected with either LPS, LPS and anti-c-Fms antibody, anti-c-Fms antibody, or PBS into the supracalvariae. Animals were sacrificed and calvariae fixation and demineralization were performed. Histological sections of calvariae were stained for tartrate-resistant acid phosphatase (TRAP). In mice administered with both LPS and the anti-cFms antibody, osteoclast numbers were lower than those in mice administered with LPS alone. Moreover, levels of TRACP-5b, a bone resorption marker in mice serum, were lower in mice administered with both LPS and the anti-c-Fms antibody than in mice administered with LPS alone. These results suggest that M-CSF and its receptor are potential therapeutic targets in LPS-induced osteoclastogenesis, and that the anti-c-Fms antibody might be useful for inhibition of inflammation-induced bone erosion. In this study, we describe and discuss the effect the anti-c-Fms antibody has on pathological osteoclastogenesis and bone resorption.

Widespread presence of small and medium enterprise (SME) and entrepreneurial businesses (EB) as well as governments' key role in tourism sphere, especially in developing countries. As a result, the importance of policymaking in SME and EB has been growing through last decade. This study is trying to identify and prioritize the factors influencing SME and EB policy in Iran tourism scope. For this research, data were collected via exploratory mixed method in two steps. Firstly, qualitative techniques such as literature review has been done to find all scholarly work and then using qualitative content analysis, factors influencing SME policy in tourism has been identified. In second step, quantitative methods, namely survey and Statistical techniques were used for analysis. Population of this study comprised policymaking and tourism entrepreneurship experts of Iran. The survey results showed there were 40 variables into six factors under two main dimensions influence on SME and EB. Factors indentified in this study can be used to formulate macro policies in the tourism industry and national policymakers can utilize these concepts for entrepreneurship and SME's development in tourism. This research contributes to the existing literature in the field of entrepreneurship policymaking by introduce a systematic framework. This new framework can provide better insights and inform thinking in the area of entrepreneurship policymaking.