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Autofluorescence as a Parameter to Study Pharmaceutical Materials
Published in Victoria Vladimirovna Roshchina, Fluorescence of Living Plant Cells for Phytomedicine Preparations, 2020
Victoria Vladimirovna Roshchina
The fluorescence spectra of intact fluorescing cells containing various substances differ in the position of the maxima and the intensity. The influence of the media and various factors on the autofluorescence of secretory and nonsecretory plant cells has been considered in a special monograph (Roshchina 2008). More information may also be gained by modeling natural secretions via the composition of mixtures from various individual compounds (Roshchina 2008, 2014). This permits a preliminary discrimination of the dominating components in the secretory cell tested. The visible fluorescence of a secreting cell depends on the chemotaxonomy and metabolism of the secreted products (Roshchina 2003, 2008, 2014). The first publications related to the identification of phenols in plant cells based on their fluorescence (Weisenböck et al. 1987; Hutzler et al. 1998). Later, the range of compounds analyzed by their emission from living cells became wider (Roshchina 2003, 2008). Fluorescent secondary metabolites occurred in secretory cells may also be applied to vital histological procedures in cell biology. Today, autofluorescence has become an excellent tool for cell imaging and stress diagnostics by, for example, pharmacologists, plant physiologists, and biochemists as well as ecologists.
Check the Cancer Before It Checks You Out
Published in Prakash Srinivasan Timiri Shanmugam, Understanding Cancer Therapies, 2018
Only when screened early for oral cancer risks is intervention possible and the treatment more effective. In this regard, autofluorescence imaging comes close to being used as a robust oral cavity cancer screening and detection technique. Early detection of small cancer foci is required to improve the survival rate. Here, autofluorescence might become useful as in vivo biochemical changes of cancer metabolism can be shown by fluorescence. However, several nondysplastic lesions may be nonfluorescent, and occasional false-positive results have been reported. Therefore, fluorescence agents are being explored to further improve oral cancer diagnostics (Olivo et al. 2011).
How to master MCQs
Published in Chung Nen Chua, Li Wern Voon, Siddhartha Goel, Ophthalmology Fact Fixer, 2017
Autofluorescence is defined as the emission of fluorescent light from ocular structures in the absence of sodium fluorescein. On the other hand, pseudo-autofluorescence results from reflection of light from light-coloured or white fundal structures such as myelinated nerve fibres, sclera, hard exudates or cotton wool spots.
Natural history of Usher type 2 with the c.2299delG mutation of USH2A in a large cohort
Published in Ophthalmic Genetics, 2022
Audrey Meunier, Xavier Zanlonghi, Anne-Françoise Roux, Jean-François Fils, Laure Caspers, Isabelle Migeotte, Marc Abramowicz, Isabelle Meunier
At first OCT acquisition, the mean age of patients was, respectively, 38 y.o. and 37 y.o. for patients with and without the c.2299delG allele. Based on Heidelberg macular map thickness, no significant difference regarding the c.2299delG presence was reported on the retinal thickness of nasal 1500, nasal 3000, and temporal 1500 and 3000 µm from fovea quadrants (Table 2). Correlation between macular thickness, age, and visual acuity was not statistically significant due to the small size of the samples. No difference was observed regarding the foveolar thickness at first consultation either (Figure 2). Only 20/51 patients had a Heidelberg OCT acquisition, leading to an insufficient amount of statistical data to allow a robust statistical test. Regarding autofluorescence imaging, no analysis was possible due to the nonavailability of this technique for many patients.
Rationale and design of the Brazilian diabetes study: a prospective cohort of type 2 diabetes
Published in Current Medical Research and Opinion, 2022
Joaquim Barreto, Vaneza Wolf, Isabella Bonilha, Beatriz Luchiari, Marcus Lima, Alessandra Oliveira, Sofia Vitte, Gabriela Machado, Jessica Cunha, Cynthia Borges, Daniel Munhoz, Vicente Fernandes, Sheila Tatsumi Kimura-Medorima, Ikaro Breder, Marta Duran Fernandez, Thiago Quinaglia, Rodrigo B. Oliveira, Fernando Chaves, Carlos Arieta, Gil Guerra-Júnior, Sandra Avila, Wilson Nadruz, Luiz Sergio F. Carvalho, Andrei C. Sposito
The autofluorescence reader (AGE Reader; DiagnOptics, Groningen, the Netherlands, serial number: 09-10138) illuminates a skin surface of ∼4 cm2, guarded against surrounding light, with an excitation light source with peak intensity at ∼370 nm. Emission light and reflected excitation light from the skin area are measured with a spectrometer in the 300–600 nm range, using glass fiber. Autofluorescence was computed by dividing the average light intensity of the emission spectrum 420–600 nm by the average light intensity of the reflected excitation spectrum 300–420 nm and expressed in arbitrary units (AU)28. The measurements are performed in triplicate, and the average value is considered the definitive value of the AGE-Skin autofluorescence. AGE-Skin autofluorescence of all patients is assessed at the volar side of the arm, 10 cm below the elbow fold, in areas without tattoos, scars, cream or sunscreen28.
Demographic and Multimodal Imaging Features of Macular Telangiectasia Type 2: Korean Macular Telangiectasia Type 2 Study – Report No. 2
Published in Ophthalmic Epidemiology, 2021
Young Ho Kim, Yoo-Ri Chung, Jaeryung Oh, Seong-Woo Kim, Christopher Seungkyu Lee, Cheolmin Yun, Boram Lee, So Min Ahn, Eun Young Choi, Sungmin Jang, Kihwang Lee
Grading was based on methods published previously.1,2,9,10 Colour FPs were graded for the presence or absence of classic features of MacTel Type 2: loss of transparency (retinal greying), dilated and blunted retinal vessels, right-angled vessels, crystalline deposits, irregular retinal pigment epithelial abnormalities, pigment plaques or clumping, and/or evidences of neovascularization. When the quality of FP was low, FAF images were checked for any vascular abnormalities such as blunted and right-angled vessels. FAF images were graded for the presence of increased or decreased autofluorescence (AF).1,11,12 Increased AF was defined as the presence of a higher grayscale value clearly detectable to the human eye. Decreased AF was categorized as the presence of a large area of decreased AF (larger than approximately 500 μm in diameter) or the presence of localized decreased AF located mostly at the end of the retinal vessels.1,12 CBR images were graded for the presence of increased reflectance. The locations of representative findings of FP, FAF, CBR, FAG, and OCT were described using the Early Treatment Diabetic Retinopathy Study (ETDRS) grid (Supplementary Figure 1).11