14 research outputs found
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
Free volume effects on ionics conductivity of pvdf-co-hfp with Li-salt complexes probing by positron annihilation techniques
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