scholarly journals Time-resolved fluorescence imaging technique for rat brain tumors analysis

2021 ◽  
Vol 2058 (1) ◽  
pp. 012028
Author(s):  
Yu S Maklygina ◽  
I D Romanishkin ◽  
A S Skobeltsin ◽  
T A Savelyeva ◽  
A A Potapov ◽  
...  
Keyword(s):  
Spectroscopic Analysis ◽  
Imaging Technique ◽  
Fluorescence Analysis ◽  
Female Rats ◽  
Time Resolved Fluorescence ◽  
Main Attention ◽  
Time Resolved ◽  
New Approach ◽  
The Difference

Abstract The paper presents a new approach to assessing the state of tissues that differ in phenotype and in the degree of immunocompetent cells activity using photosensitizers (PS) and time-resolved fluorescence analysis methods. The main attention is paid to the detection of differences between tumor cells and tumor-associated macrophages (TAM) using spectroscopic and microscopic methods by the fluorescent kinetics signal and the difference in the accumulation of PS (the accumulation is several times greater in macrophages). The results of the PS photoluminescence study were obtained using two different techniques: time-resolved spectroscopy and time-resolved fluorescence microscopy (FLIM). Time-resolved spectroscopic analysis of the PS fluorescence lifetime was performed on adult female rats with induced C6 glioma in vivo. 5-ALA-induced Pp IX, which is widely used in clinical practice for carrying out effective conduction photodiagnostics and PDT, was used as the PS.

255 THE ESTROGENIC EVALUATION OF PARABENS USING RAT UTERINE CALBINDIN-D9k

2010 ◽  
Vol 22 (1) ◽  
pp. 285
Author(s):  
T. T. B. Vo ◽  
E. B. Jeung
Keyword(s):  
Gene Expression ◽  
Adverse Effects ◽  
Treated Group ◽  
Environmental Chemicals ◽  
Female Rats ◽  
Protein Levels ◽  
Calbindin D9k ◽  
The Difference

In the current study, calbindin-D9k (CaBP-9k), a potent biomarker for screening estrogen-like environmental chemicals in vivo and in vitro, was adopted to examine the potential estrogen-like property of the following parabens: propyl-, isopropyl-, butyl-, and isobutyl-paraben. Immature female rats were administered for 3 days from postnatal day 14 to 16 with 17?-ethinylestradiol (EE, 1 mg/kg of body weight (BW) per day) or parabens (62.5, 250, and 1000 mg/kg of BW per day). In uterotrophic assays, significantly increased uterus weights were detected in the EE-treated group and in the groups treated with the greatest dose of isopropyl-, butyl- and isobutyl-paraben. In addition, these parabens induced uterine CaBP-9k mRNA and protein levels, whereas co-treatment of parabens and fulvestrant (Faslodex, formerly known as ICI 182, 780), a pure estrogen receptor (ER) antagonist, completely reversed the paraben-induced gene expression and increased uterine weights. To investigate the ER-mediated mechanism(s) by which parabens exert their effects, the expression level of ERα and progesterone receptor (PR) was analyzed. Exposure to EE or parabens caused a dramatic decrease in expression of both ER? mRNA and protein levels, whereas co-treatment with fulvestrant reversed these effects. These data showed the difference of CaBP-9k and ER? expression, suggesting that CaBP-9k might not express via ER? pathway. In the effect of parabens on CaBP-9k expression through PR mediation, a significantly increased expression of uterine PR gene, a well-known ER regulating gene, at both transcriptional and translational levels was indicated in the greatest dose of isopropyl- and butyl-paraben. These parabens induced PR gene expression that was completely blocked by fulvestrant. This result indicates that CaBP-9k expression might involve PR mediates in the estrogenic effect of paraben in immature rat uteri. Taken together, parabens exhibited an estrogen-like property in vivo, which might be mediated by a PR and/or ER? signaling pathway. In addition, our results expanded the current understanding of the potential adverse effects of parabens associated with their estrogen-like activities. Further investigation is needed to elucidate in greater detail the adverse effects of parabens in humans and wildlife.

scholarly journals A Multifocal Multiphoton Volumetric Imaging Technique for High Speed Time-Resolved FRET Imaging in vivo

2016 ◽  
Vol 110 (3) ◽  
pp. 165a ◽  
Author(s):  
Simon P. Poland ◽  
James A. Levitt ◽  
Nikola Krstajić ◽  
Ahmet Erdogen ◽  
Richard J. Walker ◽  
...  
Keyword(s):  
High Speed ◽  
Imaging Technique ◽  
Time Resolved ◽  
Volumetric Imaging

scholarly journals Binding of Coumarin 334 withβ-Cyclodextrin and with C-Hexylpyrogallol[4]arene: Opposite Fluorescence Behavior

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Chandrasekaran Sowrirajan ◽  
Enoch Israel Vijayaraj Muthu Vijayan
Keyword(s):  
Excited State ◽  
Inclusion Complexation ◽  
Fluorescence Analysis ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Host Molecules ◽  
Protonation Equilibrium ◽  
Decay Pattern ◽  
Strong Inclusion ◽  
2D Roesy

We report here the structure of the host-guest complexes of Coumarin 334 (C334) withβ-cyclodextrin (β-CD) and with C-hexylpyrogallol[4]arene (C-HPA) and the effect of acidity on the neutral-cation equilibrium of C334 in water and in the presence of the host molecules. The structures of the host-guest complexes are proposed on the basis of the change of fluorescence on the addition ofβ-CD or C-HPA to C334 and by 2D ROESY spectroscopy. Opposite fluorescence behaviors, that is, quenching of fluorescence inβ-CD and enhancement of fluorescence in C-HPA are observed. Time-resolved fluorescence analysis is done for the complexation, and biexponential decay pattern is observed. The possible strong inclusion complexation with C-HPA is explained. The ground and the excited statepKavalues for the protonation equilibrium of C334 in water and the difficulty of protonation in the presence of the host molecules are discussed.

scholarly journals Time-resolved fluorescence analysis of LHCII in the presence of PsbS at neutral and low pH

2018 ◽  
Author(s):  
Emanuela Crisafi ◽  
Maithili Krishnan ◽  
Anjali Pandit
Keyword(s):  
Lipid Membranes ◽  
Light Stress ◽  
Fluorescence Analysis ◽  
Low Ph ◽  
Photochemical Quenching ◽  
Ph Sensing ◽  
Fluorescence Lifetimes ◽  
Light Harvesting Complexes ◽  
Time Resolved

In plant chloroplast membranes, non-photochemical quenching (NPQ) is activated as a response to a low luminal pH and controlled by the pH-sensing protein PsbS. It has been proposed that PsbS directly interacts with the light-harvesting complexes (LHCII) of Photosystem II, inducing quenching of LHCII Chl excitations, whilst others proposed that PsbS has an indirect role in controlling the organization of the membrane. In this study, we systematically test the influence of low pH and PsbS on the fluorescence lifetimes of membrane-embedded spinach LHCII. The proteoliposome preparations contain LHCII in mild quenched states, aimed to mimic fluorescence conditions of dark-adapted leaves. We find that under those conditions, acidification and the presence of PsbS do not have significant effect on the LHCII Chl fluorescence lifetimes. This supports a view in which the functional role of PsbS consists of re-organizing the thylakoid membrane under light stress, rather than creating direct quencher states. The dimeric form of PsbS appears to be destabilized in lipid membranes compared to detergent micelles, which might explain why the low-pH PsbS crystal structure is dimeric, while in vivo activation of PsbS has been correlated with its monomerization at low pH.

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