Anisotropy links cell shapes to tissue flow during convergent extension

Within developing embryos, tissues flow and reorganize dramatically on timescales as short as minutes. This includes epithelial tissues, which often narrow and elongate in convergent extension movements due to anisotropies in external forces or in internal cell-generated forces. However, the mechanisms that allow or prevent tissue reorganization, especially in the presence of strongly anisotropic forces, remain unclear. We study this question in the converging and extending Drosophila germband epithelium, which displays planar polarized myosin II and experiences anisotropic forces from neighboring tissues, and we show that in contrast to isotropic tissues, cell shape alone is not sufficient to predict the onset of rapid cell rearrangement. From theoretical considerations and vertex model simulations, we predict that in anisotropic tissues two experimentally accessible metrics of cell patterns, the cell shape index and a cell alignment index, are required to determine whether an anisotropic tissue is in a solid-like or fluid-like state. We show that changes in cell shape and alignment over time in the Drosophila germband predict the onset of rapid cell rearrangement in both wild-type and snail twist mutant embryos, where our theoretical prediction is further improved when we also account for cell packing disorder. These findings suggest that convergent extension is associated with a transition to more fluid-like tissue behavior, which may help accommodate tissue shape changes during rapid developmental events

Is there any correlation between levels of serum ostepontin, CEA, and FDG uptake in lung cancer patients with bone metastasis?

Seven, Bedri/0000-0002-2645-7661WOS: 000371940100006PubMed: 26521996Objective: in this study, an evaluation was made of the relationship between the serum levels of carcinoembryonic antigen (CEA), osteopontin (OPN), and the semi-quantitative parameters of 18-fluoro2-deoxyglucose positron emission tomography/computed tomography (F-18-FDG PET/CT) in lung cancer patients with bone metastasis. Material and methods: the evaluation included 42 non-small cell lung cancer (NSCLC) and 31 small cell lung cancer (SCLC) patients who were referred to our institution for staging by F-18-FDG PET/CT. the biochemical parameters measured included CEA and OPN serum levels. Results: Serum levels of OPN in NSCLC patients with and without bone metastasis were 21.20 +/- 4.97 ng/ml and 13.33 +/- 4.53 ng/ml, respectively (p < 0.05). in SCLC patients with and without bone metastasis serum OPN levels were 23.95 +/- 4.78 ng/ml and 17.30 +/- 3.09 ng/ml, respectively (p < 0.05). Serum levels of CEA in NSCLC patients with and without bone metastasis were 33.79 +/- 6.49 ng/ml and 11.74 +/- 2.96 ng/ml, respectively (p < 0.05). in SCLC patients with and without bone metastasis serum levels of CEA were 28.93 +/- 4.59 ng/ml and 13.88 +/- 4.47 ng/ml, respectively (p < 0.05). There were no correlations between primary tumor SUVmax, and serum levels of CEA and OPN. Conclusions: Bone metastasis can be detected in patients with lung cancer by measuring CEA and OPN levels. Increased levels of CEA and OPN levels may be considered an early warning sign in patients needing accurate imaging, as they are at higher risk of bone metastasis. (C) 2015 Elsevier Espana, S.L.U. and SEMNIM. All rights reserved

Melatonin prevents radiation-induced oxidative stress and periodontal tissue breakdown in irradiated rats with experimental periodontitis

Kara, Adem/0000-0002-5766-6116;WOS: 000399955500015PubMed: 27510437Background and ObjectiveThe aim of this study was to analyze the biochemical and histochemical effects of radiation therapy and protective melatonin administration on periodontal tissues in rats with experimental periodontitis. Material and MethodsSixty male Sprague Dawley rats were divided into six groups, as follows: control; experimental periodontitis (Ped); radiotherapy administration (Rt); experimental periodontitis and exposure to irradiation (Ped-Rt); radiotherapy and protective melatonin administration (Rt-Mel); and periodontitis, radiation therapy and protective melatonin administration (Ped-Rt-Mel). the rats were killed at the end of the experimental procedure, and the oxidative stress level and periodontal destruction were compared among the groups. ResultsThe oxidative stress index and the levels of 8-hydroxy-2-deoxyguanosine, malondialdehyde and C-terminal telopeptide of type I collagen were found to be significantly higher in the Ped-Rt group compared with the Ped group (p < 0.05), and the levels were lower in the Ped-Rt-Mel group than in the Ped-Rt group (p < 0.05). Alveolar bone destruction and attachment level were also significantly lower in the Ped-Rt-Mel group than in the Ped-Rt group (p < 0.05). ConclusionIt was found that radiotherapy increased oxidative stress, the periodontal attachment level and alveolar bone loss, and protective melatonin administration significantly reduced the oxidative parameters and prevented periodontal damage in irradiated rats with experimental periodontitis. Further research is needed regarding the use of systemic melatonin administration before radiation therapy

Melatonin prevents radiation-induced oxidative stress and periodontal tissue breakdown in irradiated rats with experimental periodontitis.

BACKGROUND AND OBJECTIVE: The aim of this study was to analyze the biochemical and histochemical effects of radiation therapy and protective melatonin administration on periodontal tissues in rats with experimental periodontitis. MATERIAL AND METHODS: Sixty male Sprague Dawley rats were divided into six groups, as follows: control; experimental periodontitis (Ped); radiotherapy administration (Rt); experimental periodontitis and exposure to irradiation (Ped-Rt); radiotherapy and protective melatonin administration (Rt-Mel); and periodontitis, radiation therapy and protective melatonin administration (Ped-Rt-Mel). The rats were killed at the end of the experimental procedure, and the oxidative stress level and periodontal destruction were compared among the groups. RESULTS: The oxidative stress index and the levels of 8-hydroxy-2'-deoxyguanosine, malondialdehyde and C-terminal telopeptide of type I collagen were found to be significantly higher in the Ped-Rt group compared with the Ped group (p < 0.05), and the levels were lower in the Ped-Rt-Mel group than in the Ped-Rt group (p < 0.05). Alveolar bone destruction and attachment level were also significantly lower in the Ped-Rt-Mel group than in the Ped-Rt group (p < 0.05). CONCLUSION: It was found that radiotherapy increased oxidative stress, the periodontal attachment level and alveolar bone loss, and protective melatonin administration significantly reduced the oxidative parameters and prevented periodontal damage in irradiated rats with experimental periodontitis. Further research is needed regarding the use of systemic melatonin administration before radiation therapy

tissue breakdown in irradiated rats with experimental periodontitis

Background and ObjectiveThe aim of this study was to analyze the biochemical and histochemical effects of radiation therapy and protective melatonin administration on periodontal tissues in rats with experimental periodontitis.Material and MethodsSixty male Sprague Dawley rats were divided into six groups, as follows: control; experimental periodontitis (Ped); radiotherapy administration (Rt); experimental periodontitis and exposure to irradiation (Ped-Rt); radiotherapy and protective melatonin administration (Rt-Mel); and periodontitis, radiation therapy and protective melatonin administration (Ped-Rt-Mel). The rats were killed at the end of the experimental procedure, and the oxidative stress level and periodontal destruction were compared among the groups.ResultsThe oxidative stress index and the levels of 8-hydroxy-2-deoxyguanosine, malondialdehyde and C-terminal telopeptide of type I collagen were found to be significantly higher in the Ped-Rt group compared with the Ped group (p < 0.05), and the levels were lower in the Ped-Rt-Mel group than in the Ped-Rt group (p < 0.05). Alveolar bone destruction and attachment level were also significantly lower in the Ped-Rt-Mel group than in the Ped-Rt group (p < 0.05).ConclusionIt was found that radiotherapy increased oxidative stress, the periodontal attachment level and alveolar bone loss, and protective melatonin administration significantly reduced the oxidative parameters and prevented periodontal damage in irradiated rats with experimental periodontitis. Further research is needed regarding the use of systemic melatonin administration before radiation therapy