Characterizing variability in in vivo Raman spectroscopic properties of different anatomical sites of normal tissue in the oral cavity

2011 ◽  
Vol 43 (2) ◽  
pp. 255-262 ◽  
Author(s):  
Mads Sylvest Bergholt ◽  
Wei Zheng ◽  
Zhiwei Huang
Author(s):  
Junchao Qian ◽  
Xiang Yu ◽  
Bingbing Li ◽  
Zhenle Fei ◽  
Xiang Huang ◽  
...  

Background:: It was known that the response of tumor cells to radiation is closely related to tissue oxygen level and fractionated radiotherapy allows reoxygenation of hypoxic tumor cells. Non-invasive mapping of tissue oxygen level may hold great importance in clinic. Objective: The aim of this study is to evaluate the role of oxygen-enhanced MR imaging in the detection of tissue oxygen levels between fractionated radiotherapy. Methods: A cohort of 10 patients with brain metastasis was recruited. Quantitative oxygen enhanced MR imaging was performed prior to, 30 minutes and 22 hours after first fractionated radiotherapy. Results: The ΔR1 (the difference of longitudinal relaxivity between 100% oxygen breathing and air breathing) increased in the ipsilateral tumor site and normal tissue by 242% and 152%, respectively, 30 minutes after first fractionated radiation compared to pre-radiation levels. Significant recovery of ΔR1 in the contralateral normal tissue (p < 0.05) was observed 22 hours compared to 30 minutes after radiation levels. Conclusion: R1-based oxygen-enhanced MR imaging may provide a sensitive endogenous marker for oxygen changes in the brain tissue between fractionated radiotherapy.


Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 172
Author(s):  
Mariusz Dziadas ◽  
Adam Junka ◽  
Henryk Jeleń

Eugenyl-β-D-glucopyranoside, also referred to as Citrusin C, is a natural glucoside found among others in cloves, basil and cinnamon plants. Eugenol in a form of free aglycone is used in perfumeries, flavourings, essential oils and in medicinal products. Synthetic Citrusin C was incubated with human saliva in several in vitro models together with substrate-specific enzyme and antibiotics (clindamycin, ciprofloxacin, amoxicillin trihydrate and potassium clavulanate). Citrusin C was detected using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Citrusin C was completely degraded only when incubated with substrate-specific A. niger glucosidase E.C 3.2.1.21 (control sample) and when incubated with human saliva (tested sample). The addition of antibiotics to the above-described experimental setting, stopped Citrusin C degradation, indicating microbiologic origin of hydrolysis observed. Our results demonstrate that Citrusin C is subjected to complete degradation by salivary/oral cavity microorganisms. Extrapolation of our results allows to state that in the human oral cavity, virtually all β-D-glucosides would follow this type of hydrolysis. Additionally, a new method was developed for an in vivo rapid test of glucosidase activity in the human mouth on the tongue using fluorescein-di-β-D-glucoside as substrate. The results presented in this study serve as a proof of concept for the hypothesis that microbial hydrolysis path of β-D-glucosides begins immediately in the human mouth and releases the aglycone directly into the gastrointestinal tract.


Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 855
Author(s):  
Paola Serrano Martinez ◽  
Lorena Giuranno ◽  
Marc Vooijs ◽  
Robert P. Coppes

Radiotherapy is involved in the treatment of many cancers, but damage induced to the surrounding normal tissue is often inevitable. Evidence suggests that the maintenance of homeostasis and regeneration of the normal tissue is driven by specific adult tissue stem/progenitor cells. These tasks involve the input from several signaling pathways. Irradiation also targets these stem/progenitor cells, triggering a cellular response aimed at achieving tissue regeneration. Here we discuss the currently used in vitro and in vivo models and the involved specific tissue stem/progenitor cell signaling pathways to study the response to irradiation. The combination of the use of complex in vitro models that offer high in vivo resemblance and lineage tracing models, which address organ complexity constitute potential tools for the study of the stem/progenitor cellular response post-irradiation. The Notch, Wnt, Hippo, Hedgehog, and autophagy signaling pathways have been found as crucial for driving stem/progenitor radiation-induced tissue regeneration. We review how these signaling pathways drive the response of solid tissue-specific stem/progenitor cells to radiotherapy and the used models to address this.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
V. K. Chava ◽  
K. Sirisha

This paper attempts to summarise the findings accumulated within the last few years concerning the hormone of darkness “melatonin.” Based on its origin, from the pineal gland until recently it was portrayed exclusively as a hormone. Due to its lipophilic nature, it is accessible to every cell. Thus, in the classic sense it is a cell protector rather than a hormone. Recent studies, by Claustrat et al. (2005), detected few extrapineal sources of melatonin like retina, gastrointestinal tract, and salivary glands. Due to these sources, research by Cutando et al. (2007), is trying to explore the implications of melatonin in the oral cavity, in addition to its physiologic anti-oxidant, immunomodulatory and oncostatic functions at systemic level that may be receptor dependent or independent. Recently, certain in vivo studies by Shimozuma et al. (2011), detected the secretion of melatonin from salivary glands further emphasising its local activity. Thus, within our confines the effects of melatonin in the mouth are reviewed, adding a note on therapeutic potentials of melatonin both systemically and orally.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Muhammad H. Khan ◽  
John J. Walsh ◽  
Jelena M. Mihailović ◽  
Sandeep K. Mishra ◽  
Daniel Coman ◽  
...  

AbstractUnder normal conditions, high sodium (Na+) in extracellular (Na+e) and blood (Na+b) compartments and low Na+ in intracellular milieu (Na+i) produce strong transmembrane (ΔNa+mem) and weak transendothelial (ΔNa+end) gradients respectively, and these manifest the cell membrane potential (Vm) as well as blood–brain barrier (BBB) integrity. We developed a sodium (23Na) magnetic resonance spectroscopic imaging (MRSI) method using an intravenously-administered paramagnetic polyanionic agent to measure ΔNa+mem and ΔNa+end. In vitro 23Na-MRSI established that the 23Na signal is intensely shifted by the agent compared to other biological factors (e.g., pH and temperature). In vivo 23Na-MRSI showed Na+i remained unshifted and Na+b was more shifted than Na+e, and these together revealed weakened ΔNa+mem and enhanced ΔNa+end in rat gliomas (vs. normal tissue). Compared to normal tissue, RG2 and U87 tumors maintained weakened ΔNa+mem (i.e., depolarized Vm) implying an aggressive state for proliferation, whereas RG2 tumors displayed elevated ∆Na+end suggesting altered BBB integrity. We anticipate that 23Na-MRSI will allow biomedical explorations of perturbed Na+ homeostasis in vivo.


2021 ◽  
Vol 161 ◽  
pp. S192-S193
Author(s):  
C. Overgaard ◽  
M.K. Sitarz ◽  
N. Bassler ◽  
H. Spejlborg ◽  
J.G. Johansen ◽  
...  

1999 ◽  
Vol 30 (4) ◽  
pp. 324-346 ◽  
Author(s):  
Elerson Gaetti-Jardim Júnior ◽  
Mario Julio Avila-Campos

Fusobacterium nucleatum is indigenous of the human oral cavity and has been involved in different infectious processes. The production of bacteriocin-like substances may be important in regulation of bacterial microbiota in oral cavity. The ability to produce bacteriocin-like substances by 80 oral F. nucleatum isolates obtained from periodontal patients, healthy individuals and Cebus apella monkeys, was examinated. 17.5% of all tested isolates showed auto-antagonism and 78.8% iso- or hetero-antagonism. No isolate from monkey was capable to produce auto-inhibition. In this study, the antagonistic substances production was variable in all tested isolates. Most of the F. nucleatum showed antagonistic activity against tested reference strains. These data suggest a possible participation of these substances on the oral microbial ecology in humans and animals. However, the role of bacteriocins in regulating dental plaque microbiota in vivo is discussed.


2000 ◽  
Vol 26 (5) ◽  
pp. 432-440 ◽  
Author(s):  
Jianan Y. Qu ◽  
Po Wing ◽  
Zhijian Huang ◽  
Dora Kwong ◽  
Jonathan Sham ◽  
...  

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