scholarly journals Roughness and pH changes of enamel surface induced by soft drinks in vitro-applications of stylus profilometry, focus variation 3D scanning microscopy and micro pH sensor

2011 ◽  
Vol 30 (3) ◽  
pp. 404-410 ◽  
Author(s):  
Mie FUJII ◽  
Yuichi KITASAKO ◽  
Alireza SADR ◽  
Junji TAGAMI
Keyword(s):  
Ph Sensor ◽  
3D Scanning ◽  
Soft Drinks ◽  
Enamel Surface ◽  
Scanning Microscopy ◽  
Ph Changes ◽  
Focus Variation

scholarly journals Erosive Effect of Different Soft Drinks on Enamel Surface in vitro: Application of Stylus Profilometry

2015 ◽  
Vol 24 (5) ◽  
pp. 451-457 ◽  
Author(s):  
Radomir Barac ◽  
Jovanka Gasic ◽  
Natasa Trutic ◽  
Slavica Sunaric ◽  
Jelena Popovic ◽  
...  
Keyword(s):  
Soft Drinks ◽  
Enamel Surface ◽  
Erosive Effect

scholarly journals pHluorin-BACE1-mCherry Acts as a Reporter for the Intracellular Distribution of Active BACE1 In Vitro and In Vivo

Cells ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 474 ◽  
Author(s):  
Lu Zhao ◽  
Yang Zhao ◽  
Fu-Lei Tang ◽  
Lei Xiong ◽  
Ce Su ◽  
...  
Keyword(s):  
Ph Dependence ◽  
Ph Sensor ◽  
Maximal Activity ◽  
Ph Changes ◽  
Fluorescence Characteristics ◽  
A Subunit ◽  
Amyloid Aβ ◽  
Bace1 Activity

β-site APP-cleaving enzyme 1 (BACE1) initiates amyloid precursor protein (APP) cleavage and β-amyloid (Aβ) production, a critical step in the pathogenesis of Alzheimer’s disease (AD). It is thus of considerable interest to investigate how BACE1 activity is regulated. BACE1 has its maximal activity at acidic pH and GFP variant—pHluorin—displays pH dependence. In light of these observations, we generated three tandem fluorescence-tagged BACE1 fusion proteins, named pHluorin-BACE1-mCherry, BACE1-mCherry-pHluorin and BACE1-mCherry-EGFP. Comparing the fluorescence characteristics of these proteins in response to intracellular pH changes induced by chloroquine or bafilomycin A1, we found that pHluorin-BACE1-mCherry is a better pH sensor for BACE1 because its fluorescence intensity responds to pH changes more dramatically and more quickly. Additionally, we found that (pro)renin receptor (PRR), a subunit of the v-ATPase complex, which is critical for maintaining vesicular pH, regulates pHluorin’s fluorescence and BACE1 activity in pHluorin-BACE1-mCherry expressing cells. Finally, we found that the expression of Swedish mutant APP (APPswe) suppresses pHluorin fluorescence in pHluorin-BACE1-mCherry expressing cells in culture and in vivo, implicating APPswe not only as a substrate but also as an activator of BACE1. Taken together, these results suggest that the pHluorin-BACE1-mCherry fusion protein may serve as a useful tool for visualizing active/inactive BACE1 in culture and in vivo.

scholarly journals Dentin erosion by whitening mouthwash associated to toothbrushing abrasion: A focus variation 3D scanning microscopy study

2013 ◽  
Vol 76 (9) ◽  
pp. 904-908 ◽  
Author(s):  
Juliana P.M. Lima ◽  
Mary A.S. Melo ◽  
Vanara F. Passos ◽  
CÍcero L.N. Braga ◽  
Lidiany K.A. Rodrigues ◽  
...  
Keyword(s):  
Microscopy Study ◽  
3D Scanning ◽  
Scanning Microscopy ◽  
Focus Variation ◽  
Dentin Erosion

scholarly journals SWI/SNF senses carbon starvation with a pH-sensitive low complexity sequence

2021 ◽  
Author(s):  
J. Ignacio Gutiérrez ◽  
Gregory P. Brittingham ◽  
Yonca B. Karadeniz ◽  
Kathleen D. Tran ◽  
Arnob Dutta ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Ph Sensor ◽  
Transcriptional Response ◽  
Low Complexity ◽  
Carbon Starvation ◽  
Ph Sensing ◽  
Ph Changes ◽  
Transcriptional Reprogramming ◽  
Biophysical Mechanism

AbstractIt is increasingly appreciated that intracellular pH changes are important biological signals. This motivates the elucidation of molecular mechanisms of pH-sensing. We determined that a nucleocytoplasmic pH oscillation was required for the transcriptional response to carbon starvation in S. cerevisiae. The SWI/SNF chromatin remodeling complex is a key mediator of this transcriptional response. We found that a glutamine-rich low complexity sequence (QLC) in the SNF5 subunit of this complex, and histidines within this sequence, were required for efficient transcriptional reprogramming during carbon starvation. Furthermore, the SNF5 QLC mediated pH-dependent recruitment of SWI/SNF to a model promoter in vitro. Simulations showed that protonation of histidines within the SNF5 QLC lead to conformational expansion, providing a potential biophysical mechanism for regulation of these interactions. Together, our results indicate that that pH changes are a second messenger for transcriptional reprogramming during carbon starvation, and that the SNF5 QLC acts as a pH-sensor.

scholarly journals The effects of soft drinks on the released of calcium from the enamel surface

2015 ◽  
Vol 27 (2) ◽  
Author(s):  
Diandra Audyla Miranti ◽  
Endang Sukartini ◽  
Milly Armilia Andang
Keyword(s):  
Calcium Release ◽  
Soft Drink ◽  
Atomic Absorption Spectrophotometry ◽  
Soft Drinks ◽  
Enamel Surface ◽  
Test Results ◽  
Soda Water ◽  
Maxillary Premolars ◽  
Mineral Loss

Introduction: Calcium release from the enamel surface is known as enamel demineralisation. Enamel demineralisation is a chemical process of mineral loss from the email structure. One of the factors that cause demineralisation is the presence of acids derived from food or beverages consumed. This study was aimed to determine the effects of soft drinks and the amount of calcium release from the enamel surface. Methods: This study was an in-vitro experimental. The population was extracted maxillary premolars from orthodontics clinics in health centres, hospitals, and private clinics throughout Bandung and Jakarta. As many as 20 crown of maxillary premolars divided into two groups. Dissolved calcium was measured using the Atomic Absorption Spectrophotometry (AAS). Data obtained was tested using an independent t-test. Results: The results showed that the amount of calcium released after exposure of soft drink was higher than soda water. The average amount of calcium released after soft drink exposure was 4122 ppm and soda water was 3492 ppm. Conclusion: Soft drink affects the calcium release from the enamel surface.

In vitro Evaluation of Enamel Surface Treated with Fluoride After Bleaching and Etching Erosive Processes

2018 ◽  
Vol 69 (7) ◽  
pp. 1714-1717
Author(s):  
Roxana Ionela Vasluianu ◽  
Norina Consuela Forna ◽  
Elena Raluca Baciu ◽  
Mirela Zaltariov ◽  
Lavinia Vasiliu ◽  
...  
Keyword(s):  
Enamel Surface ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Fluoride Treatment ◽  
Enamel Structure ◽  
Erosion Effect ◽  
Enamel Composition ◽  
Morphology Changes ◽  
Scanning Electron

The anti-erosion effect of fluoride on the enamel surface was investigated by ATR-FTIR, SEM and EDX techniques. Four extracted teeth (two incisors and two premolars) were initially bleached with carabamide peroxide and etched with ortho-phosphoric acid then fluoride treatment was applied. Significant differences in enamel composition and morphology were observed providing the effect of fluoride application in remineralization of teeth. Infrared spectroscopy was employed to probe the changes in enamel structure. Scanning electron microscopy/energy dispersive X-ray spectroscopy analysis revealed higher content in F of teeth enamel. Morphology changes revealed a re-mineralization of enamel surface after the treatment with fluoride gel.

scholarly journals Cofilin is a pH sensor for actin free barbed end formation: role of phosphoinositide binding

2008 ◽  
Vol 183 (5) ◽  
pp. 865-879 ◽  
Author(s):  
Christian Frantz ◽  
Gabriela Barreiro ◽  
Laura Dominguez ◽  
Xiaoming Chen ◽  
Robert Eddy ◽  
...  
Keyword(s):  
Actin Filament ◽  
Structural Changes ◽  
Ph Sensor ◽  
Ph Sensitive ◽  
Actin Binding ◽  
Filamentous Actin ◽  
Filament Dynamics ◽  
Ph Dependent ◽  
Dynamics Simulations

Newly generated actin free barbed ends at the front of motile cells provide sites for actin filament assembly driving membrane protrusion. Growth factors induce a rapid biphasic increase in actin free barbed ends, and we found both phases absent in fibroblasts lacking H+ efflux by the Na-H exchanger NHE1. The first phase is restored by expression of mutant cofilin-H133A but not unphosphorylated cofilin-S3A. Constant pH molecular dynamics simulations and nuclear magnetic resonance (NMR) reveal pH-sensitive structural changes in the cofilin C-terminal filamentous actin binding site dependent on His133. However, cofilin-H133A retains pH-sensitive changes in NMR spectra and severing activity in vitro, which suggests that it has a more complex behavior in cells. Cofilin activity is inhibited by phosphoinositide binding, and we found that phosphoinositide binding is pH-dependent for wild-type cofilin, with decreased binding at a higher pH. In contrast, phosphoinositide binding by cofilin-H133A is attenuated and pH insensitive. These data suggest a molecular mechanism whereby cofilin acts as a pH sensor to mediate a pH-dependent actin filament dynamics.

Stimulus Induced pH Changes in Cochlear Implants: An In Vitro and In Vivo Study

2001 ◽  
Vol 29 (9) ◽  
pp. 791-802 ◽  
Author(s):  
Christie Q. Huang ◽  
Paul M. Carter ◽  
Robert K. Shepherd
Keyword(s):  
Cochlear Implants ◽  
In Vivo Study ◽  
Ph Changes
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