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- Talebizadeh, Nooshin, 1977-, et al.
(author)
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Objective automated quantification of fluorescence signal in histological sections of rat lens
- 2017
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In: Cytometry Part A. - : Wiley. - 1552-4922 .- 1552-4930. ; 91:8, s. 815-821
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Journal article (peer-reviewed)abstract
- Visual quantification and classification of fluorescent signals is the gold standard in microscopy. The purpose of this study was to develop an automated method to delineate cells and to quantify expression of fluorescent signal of biomarkers in each nucleus and cytoplasm of lens epithelial cells in a histological section. A region of interest representing the lens epithelium was manually demarcated in each input image. Thereafter, individual cell nuclei within the region of interest were automatically delineated based on watershed segmentation and thresholding with an algorithm developed in Matlab™. Fluorescence signal was quantified within nuclei, cytoplasms and juxtaposed backgrounds. The classification of cells as labelled or not labelled was based on comparison of the fluorescence signal within cells with local background. The classification rule was thereafter optimized as compared with visual classification of a limited dataset. The performance of the automated classification was evaluated by asking 11 independent blinded observers to classify all cells (n = 395) in one lens image. Time consumed by the automatic algorithm and visual classification of cells was recorded. On an average, 77% of the cells were correctly classified as compared with the majority vote of the visual observers. The average agreement among visual observers was 83%. However, variation among visual observers was high, and agreement between two visual observers was as low as 71% in the worst case. Automated classification was on average 10 times faster than visual scoring. The presented method enables objective and fast detection of lens epithelial cells and quantification of expression of fluorescent signal with an accuracy comparable with the variability among visual observers.
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| 2. |
- Yu, Zhaohua, 1983-, et al.
(author)
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Measuring temperature in the lens during experimental heat load indirectly as light scattering increase rate
- 2017
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In: Journal of Biomedical Optics. - 1083-3668 .- 1560-2281. ; 22:1
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Journal article (peer-reviewed)abstract
- The current study aims to experimentally estimate the temperature in the lens due to heat load indirectly from the measurement of increase rate of temperature-induced light scattering. The lens was extracted from Sprague-Dawley rats and put into a temperature-controlled cuvette filled with balanced salt solution. Altogether, 80 lenses were equally divided on four temperature groups. Each lens was exposed for 5 minutes to temperature depending on group belonging while the intensity of forward light scattering was recorded. The inclination coefficient of light scattering increase at the temperature 37, 40, 43, and 46 ºC was estimated as a CI(0.95), 3.1±0.8, 4.4±0.8, 5.5±0.9 and 7.0±0.8 x10-4 tEDC/s, respectively. The Arrhenius equation implies that the natural logarithm of the inclination coefficient is linearly dependent on the inverse of the temperature. The proportionality constant and the intercept were 9.6±2.4 x103 K and 22.8±7.7. The activation energy was 8.0±2.0 x101 kJ·mol-1. The current experiment implies that if averaging 20 measurements of inclination coefficients in a new experiment at constant heat load, the confidence limits for predicted temperature correspond to ±1.9 °C. With the proportionality constant and the intercept estimated in the current experiment, the in vivo temperature in the lens can be determined retrospectively with sufficient resolution.
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