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Improving Diagnosis of Cervical Pre-Cancer: Combination of PCA and SVM Applied on Fluorescence Lifetime Images. PHOTONICS 2018. [DOI: 10.3390/photonics5040057] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We report a significant improvement in the diagnosis of cervical cancer through a combined application of principal component analysis (PCA) and support vector machine (SVM) on the average fluorescence decay profile of Fluorescence Lifetime Images (FLI) of epithelial hyperplasia (EH) and CIN-I cervical tissue samples, obtained ex-vivo. The fast and slow components of double exponential fitted fluorescence lifetimes were found to be higher for EH compared to the lifetimes of CIN-I samples. Application of PCA to the average time-resolved fluorescence decay profiles showed that the 2nd PC, in combination with 1st PC, enhanced the discrimination between EH and CIN-I tissues. Fluorescence lifetime and PC scores were then classified separately by using SVM support vector machine to identify the two. On applying SVM to a combination of fluorescence lifetime and PC scores, diagnostic capability improved significantly.
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Xu Z, Reilley M, Li R, Xu M. Mapping absolute tissue endogenous fluorophore concentrations with chemometric wide-field fluorescence microscopy. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:66009. [PMID: 28617923 DOI: 10.1117/1.jbo.22.6.066009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 05/30/2017] [Indexed: 05/24/2023]
Abstract
We report chemometric wide-field fluorescence microscopy for imaging the spatial distribution and concentration of endogenous fluorophores in thin tissue sections. Nonnegative factorization aided by spatial diversity is used to learn both the spectral signature and the spatial distribution of endogenous fluorophores from microscopic fluorescence color images obtained under broadband excitation and detection. The absolute concentration map of individual fluorophores is derived by comparing the fluorescence from “pure” fluorophores under the identical imaging condition following the identification of the fluorescence species by its spectral signature. This method is then demonstrated by characterizing the concentration map of endogenous fluorophores (including tryptophan, elastin, nicotinamide adenine dinucleotide, and flavin adenine dinucleotide) for lung tissue specimens. The absolute concentrations of these fluorophores are all found to decrease significantly from normal, perilesional, to cancerous (squamous cell carcinoma) tissue. Discriminating tissue types using the absolute fluorophore concentration is found to be significantly more accurate than that achievable with the relative fluorescence strength. Quantification of fluorophores in terms of the absolute concentration map is also advantageous in eliminating the uncertainties due to system responses or measurement details, yielding more biologically relevant data, and simplifying the assessment of competing imaging approaches.
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Affiliation(s)
- Zhang Xu
- Wenzhou Medical University, The Second Affiliated Hospital and Yuying Children's Hospital, Department of Pediatrics, Wenzhou, China
| | - Michael Reilley
- Fairfield University, Department of Physics, Fairfield, Connecticut, United States
| | - Run Li
- Fairfield University, Department of Mechanical Engineering, Fairfield, Connecticut, United States
| | - Min Xu
- Fairfield University, Department of Physics, Fairfield, Connecticut, United States
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Messina F, El-Zohry AM, Mohammed OF, Chergui M. The Role of Site-Specific Hydrogen Bonding Interactions in the Solvation Dynamics of N-Acetyltryptophanamide. J Phys Chem B 2012; 116:10730-8. [DOI: 10.1021/jp305363y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Fabrizio Messina
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide
(LSU), ISIC, Faculté des Sciences de Base, station 6, CH-1015
Lausanne-Dorigny, Switzerland
| | - Ahmed M. El-Zohry
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide
(LSU), ISIC, Faculté des Sciences de Base, station 6, CH-1015
Lausanne-Dorigny, Switzerland
- Chemistry Department, Faculty of Science, Assiut University, Assiut 71516, Egypt
| | - Omar F. Mohammed
- Chemistry Department, Faculty of Science, Assiut University, Assiut 71516, Egypt
| | - Majed Chergui
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide
(LSU), ISIC, Faculté des Sciences de Base, station 6, CH-1015
Lausanne-Dorigny, Switzerland
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Khosroshahi ME, Rahmani M. Detection and Evaluation of Normal and Malignant Cells Using Laser-Induced Fluorescence Spectroscopy. J Fluoresc 2011; 22:281-8. [DOI: 10.1007/s10895-011-0958-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 08/30/2011] [Indexed: 10/17/2022]
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Lee JS, Cox DD. Robust Smoothing: Smoothing Parameter Selection and Applications to Fluorescence Spectroscopy. Comput Stat Data Anal 2010; 54:3131-3143. [PMID: 20729976 DOI: 10.1016/j.csda.2009.08.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Fluorescence spectroscopy has emerged in recent years as an effective way to detect cervical cancer. Investigation of the data preprocessing stage uncovered a need for a robust smoothing to extract the signal from the noise. Various robust smoothing methods for estimating fluorescence emission spectra are compared and data driven methods for the selection of smoothing parameter are suggested. The methods currently implemented in R for smoothing parameter selection proved to be unsatisfactory, and a computationally efficient procedure that approximates robust leave-one-out cross validation is presented.
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Affiliation(s)
- Jong Soo Lee
- Department of Statistics, Carnegie Mellon University, Pittsburgh, PA, USA
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Polzer H, Haasters F, Prall WC, Saller MM, Volkmer E, Drosse I, Mutschler W, Schieker M. Quantification of fluorescence intensity of labeled human mesenchymal stem cells and cell counting of unlabeled cells in phase-contrast imaging: an open-source-based algorithm. Tissue Eng Part C Methods 2010; 16:1277-85. [PMID: 20218817 DOI: 10.1089/ten.tec.2009.0745] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Assessment of cell fate is indispensable to evaluate cell-based therapies in regenerative medicine. Therefore, a widely used technique is fluorescence labeling. A major problem still is the standardized, noninvasive, and reliable quantification of fluorescence intensity of adherent cell populations on single-cell level, since total fluorescence intensity must be correlated to the cell number. Consequently, the aim of the present study was to produce and validate an open-source-based algorithm, capable of measuring the total fluorescence intensity of cell populations and assessing the total cell number in phase-contrast images. To verify the algorithms' capacity to assess fluorescence intensity, human mesenchymal stem cells were transduced to stably express enhanced green fluorescent protein and results produced by the algorithm were compared to flow cytometry analysis. No significant differences could be observed at any time (p ≥ 0.443). For validation of the algorithm for cell counting in phase-contrast images, adherent human mesenchymal stem cells were manually counted and compared to results produced by the algorithm (correlation coefficient [CC] r = 0.975), nuclei staining (CC r = 0.997), and hemocytometer (CC r = 0.629). We conclude that applying the developed algorithm in routine practice allows robust, fast, and reproducible assessment of fluorescence intensity and cell numbers in simple large-scale microscopy. The method is easy to perform and open source based.
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Affiliation(s)
- Hans Polzer
- Department of Surgery, Experimental Surgery and Regenerative Medicine, University of Munich (LMU), Munich, Germany
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Mark S, Salman A, Grossman N, Gopas J, Sahu RK, Mordechai S. Fluorescence spectroscopy ofH-rastransfected murine fibroblasts: A comparison with Monte Carlo simulations. Biopolymers 2010; 93:132-40. [DOI: 10.1002/bip.21310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Bogomolny E, Mordechai S, Zwielly A, Huleihel M. Early detection of premalignant changes in cell cultures using light-induced fluorescence spectroscopy. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2009; 38:971-80. [DOI: 10.1007/s00249-009-0488-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Revised: 05/07/2009] [Accepted: 05/13/2009] [Indexed: 11/25/2022]
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Palmer GM, Keely PJ, Breslin TM, Ramanujam N. Autofluorescence Spectroscopy of Normal and Malignant Human Breast Cell Lines¶. Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2003)0780462asonam2.0.co2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Grégoire G, Jouvet C, Dedonder C, Sobolewski AL. Ab initio Study of the Excited-State Deactivation Pathways of Protonated Tryptophan and Tyrosine. J Am Chem Soc 2007; 129:6223-31. [PMID: 17447763 DOI: 10.1021/ja069050f] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In recent experiments, the excited-state lifetimes of protonated aromatic amino acids (TrpH+ and TyrH+) have been recorded by means of pump-probe photodissociation technique. The lifetime of TyrH+ is much longer than that of TrpH+, which has been initially rationalized on the basis of a simple phenomenological model. Besides, specific photofragments including the formation of radical cation after hydrogen loss are observed for TrpH+ that are not found for TyrH+. The ab initio calculations reported here for TrpH+ and TyrH+ using a coupled-cluster method are meant to track the rich photochemistry of these protonated amino acids following UV excitation.
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Affiliation(s)
- Gilles Grégoire
- Laboratoire de Physique des Lasers du CNRS, Institut Galilée, Université Paris 13, 93430 Villetaneuse, France.
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Kamilya T, Pal P, Talapatra GB. Interaction of Ovalbumin with Phospholipids Langmuir−Blodgett Film. J Phys Chem B 2007; 111:1199-205. [PMID: 17266275 DOI: 10.1021/jp063377l] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Interaction of native ovalbumin (OVA) with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) Langmuir-Blodgett monolayer has been studied at the air-water interface. A compressibility study shows the positive association with DPPC. Adsorption kinetics shows that the protein adsorption is a one-step process and the amount of protein adsorbed depends on the concentration of protein at the water subphase. Incorporation of protein into the DPPC layer is surface-pressure dependent. The compressibility study indicates that the DPPC-OVA interaction is hydrophobic in nature and structural reorganization is eminent to adjust the hydrophobic mismatch between DPPC acyl chains and OVA hydrophobic moieties. At higher pressure, OVA tends to squeeze out from the DPPC monolayer. A nanometer scale FE-SEM image confirms this observation. Globular aggregates of protein of dimension 60-80 nm were observed in DPPC-OVA supported film. Steady-state fluorescence spectroscopy suggests that the tryptophan residues of OVA are main emitting species. The blue shift of tryptophan fluorescence in supported film may be due to the tryptophan molecule of protein exposed to the hydrophobic air phase.
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Affiliation(s)
- Tapanendu Kamilya
- Department of Spectroscopy, Indian Association for the Cultivation of Science, Jadavpur, Kolkata--700032, India
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Chidananda SM, Satyamoorthy K, Rai L, Manjunath AP, Kartha VB. Optical diagnosis of cervical cancer by fluorescence spectroscopy technique. Int J Cancer 2006; 119:139-45. [PMID: 16450394 DOI: 10.1002/ijc.21825] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In the present work, we examine normal and malignant stage IIIB cervical tissue by laser induced fluorescence, with 2 different objectives. (i) Development of the fluorescence spectroscopy technique as a standard optical method for discrimination of normal and malignant tissue samples and, (ii) Optimization of the technique by the method of matching of a sample spectrum with calibration sets of spectra of pathologically certified samples. Laser-induced fluorescence spectra were measured using samples from 62 subjects at different excitation wavelengths. Principal component analysis (PCA) of spectra and intensity ratios of curve-resolved fluorescence peaks were tested for discrimination. It was found that PCA of total fluorescence at 325 nm excitation gives specificity and sensitivity over 95%. Use of calibration sets of spectra of histo-pathologically certified samples combined with PCA for matching and pass/fail classification of test samples is shown to have high sensitivity/specificity for routine diagnostic purposes as well as for possible staging of the disease. Further, the multi-component origin of the fluorescence spectra is illustrated by curve resolution and fluorescence spectra of separated proteins of tissue homogenates.
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Affiliation(s)
- Siddappa M Chidananda
- Center for Molecular and Cellular Biology, Manipal Academy of Higher Education, Science Center, Manipal, Karnataka, India
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Kang H, Jouvet C, Dedonder-Lardeux C, Martrenchard S, Grégoire G, Desfrançois C, Schermann JP, Barat M, Fayeton JA. Ultrafast deactivation mechanisms of protonated aromatic amino acids following UV excitation. Phys Chem Chem Phys 2005; 7:394-8. [PMID: 19785164 DOI: 10.1039/b414986f] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- H Kang
- Laboratoire de Photophysique Moléculaire du CNRS, Université Paris-Sud, Bât. 210, 91405 Orsay, France.
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Hansch A, Sauner D, Hilger I, Böttcher J, Malich A, Frey O, Bräuer R, Kaiser WA. Autofluorescence spectroscopy in whole organs with a mobile detector system. Acad Radiol 2004; 11:1229-36. [PMID: 15561569 DOI: 10.1016/j.acra.2004.07.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2004] [Accepted: 07/27/2004] [Indexed: 11/26/2022]
Abstract
RATIONALE AND OBJECTIVES Autofluorescence can be exploited to obtain spectroscopic information about tissues or organs in a noninvasive fashion. The knowledge of normal organ patterns is a prerequisite for subsequent characterization of pathological states, eg, inflammation or tumors. Therefore, the aim of this study was to investigate the autofluorescence properties of healthy organs in mice. MATERIALS AND METHODS Organs from C57Bl/6 mice were removed in toto and stored in physiologic sodium chloride solution on ice (non-perfused specimens). Investigations were performed with a custom-made mobile fluorescence detector. Excitation-emission matrices (EEMs) were measured in selected organs (bladder, brain, kidney, liver, and spleen) (n = 5). Afterwards, single-emission spectra were obtained in selected organs (bladder, colon, brain, kidney, liver, and spleen) and peak fluorescence signal intensities were calculated (n = 9). RESULTS EEMs showed that excitation at wavelengths from 300-310 nm (emission spectra in all samples of bladder and brain; probably caused by collagen/elastin) and from 350-360 nm (emission spectra in all samples with the exception of spleen; probably caused by NAD(P)H) seem to be best suited for autofluorescence measurements in organs. The single-emission spectra measurements were noticeably different in terms of occurrence (yes/no response) and intensity of fluorescence emission peaks in different organs. CONCLUSION Combined autofluorescence measurements of collagen/elastin (for structural information) and NAD(P)H (for functional information) allow conclusions about the target organs. Therefore, autofluorescence measurements seem to be a diagnostic tool feasible for characterization of tissue.
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Affiliation(s)
- Andreas Hansch
- Institute of Diagnostic and Interventional Radiology, Friedrich Schiller University Jena, Bachstr. 18, D-07743 Jena, Germany.
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Palmer GM, Keely PJ, Breslin TM, Ramanujam N. Autofluorescence spectroscopy of normal and malignant human breast cell lines. Photochem Photobiol 2004; 78:462-9. [PMID: 14653577 DOI: 10.1562/0031-8655(2003)078<0462:asonam>2.0.co;2] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The fluorescence of tryptophan, reduced nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) and flavin adenine dinucleotide (FAD) were characterized in normal human breast cells as well as in malignant human breast cells of similar and dissimilar genetic origins. Fluorescence measurements of each cell line were made over a wide range of cell concentrations, and the fluorescence per cell was determined from the slope in the linear range of the fluorescence intensity vs cell concentration plot. All of the malignant cells showed a statistically significant decrease in the tryptophan fluorescence per cell relative to that of the normal cells. No statistically significant differences were observed in the NAD(P)H or FAD fluorescence per cell between the normal and any of the malignant cell types. NAD(P)H fluorescence was also imaged from monolayers of the normal and malignant cells (of similar genetic origin) using two-photon fluorescence microscopy. A statistically significant decrease in the NAD(P)H fluorescence with malignancy was observed, suggesting that fluorescence imaging of single cells or the cell monolayer preparation may provide more contrast than volume-averaged fluorescence measurements of cells in suspension. In conclusion, the differences in normal and malignant human breast tissue fluorescence spectra may be attributed in part to differences in the intrinsic cellular fluorescence of normal and malignant breast epithelial cells.
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Affiliation(s)
- Gregory M Palmer
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI 53706, USA
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Palmer GM, Keely PJ, Breslin TM, Ramanujam N. Autofluorescence Spectroscopy of Normal and Malignant Human Breast Cell Lines¶. Photochem Photobiol 2003. [DOI: 10.1562/0031-8655(2003)078%3c0462:asonam%3e2.0.co;2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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