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Guo Y, Wang L, Luo Z, Zhu Y, Gao X, Weng X, Wang Y, Yan W, Qu J. Dynamic Volumetric Imaging of Mouse Cerebral Blood Vessels In Vivo with an Ultralong Anti-Diffracting Beam. Molecules 2023; 28:4936. [PMID: 37446598 DOI: 10.3390/molecules28134936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 06/19/2023] [Accepted: 06/21/2023] [Indexed: 07/15/2023] Open
Abstract
Volumetric imaging of a mouse brain in vivo with one-photon and two-photon ultralong anti-diffracting (UAD) beam illumination was performed. The three-dimensional (3D) structure of blood vessels in the mouse brain were mapped to a two-dimensional (2D) image. The speed of volumetric imaging was significantly improved due to the long focal length of the UAD beam. Comparing one-photon and two-photon UAD beam volumetric imaging, we found that the imaging depth of two-photon volumetric imaging (80 μm) is better than that of one-photon volumetric imaging (60 μm), and the signal-to-background ratio (SBR) of two-photon volumetric imaging is two times that of one-photon volumetric imaging. Therefore, we used two-photon UAD volumetric imaging to perform dynamic volumetric imaging of mouse brain blood vessels in vivo, and obtained the blood flow velocity.
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Affiliation(s)
- Yong Guo
- State Key Laboratory of Radio Frequency Heterogeneous Integration (Shenzhen University), College of Physics and Optoelectronic Engineering, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Luwei Wang
- State Key Laboratory of Radio Frequency Heterogeneous Integration (Shenzhen University), College of Physics and Optoelectronic Engineering, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Ziyi Luo
- State Key Laboratory of Radio Frequency Heterogeneous Integration (Shenzhen University), College of Physics and Optoelectronic Engineering, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Yinru Zhu
- State Key Laboratory of Radio Frequency Heterogeneous Integration (Shenzhen University), College of Physics and Optoelectronic Engineering, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Xinwei Gao
- State Key Laboratory of Radio Frequency Heterogeneous Integration (Shenzhen University), College of Physics and Optoelectronic Engineering, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Xiaoyu Weng
- State Key Laboratory of Radio Frequency Heterogeneous Integration (Shenzhen University), College of Physics and Optoelectronic Engineering, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Yiping Wang
- State Key Laboratory of Radio Frequency Heterogeneous Integration (Shenzhen University), College of Physics and Optoelectronic Engineering, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Wei Yan
- State Key Laboratory of Radio Frequency Heterogeneous Integration (Shenzhen University), College of Physics and Optoelectronic Engineering, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Junle Qu
- State Key Laboratory of Radio Frequency Heterogeneous Integration (Shenzhen University), College of Physics and Optoelectronic Engineering, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China
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2
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Alvarez-Venicio V, Castro-Beltrán R, Ramos-Ortiz G, Rodríguez M, Alba-Rosales JE, Gutiérrez-Juárez G, Santillán R, Ochoa ME, Flores-Villavicencio LL, Sabanero-López M. Red fluorescent benzothiadiazole derivative loaded in different nanoformulations: Optical properties and their use in bio-imaging. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 290:122250. [PMID: 36566533 DOI: 10.1016/j.saa.2022.122250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/09/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
Fluorophores with optimized nonlinear optical properties have become prominent as contrast labels in laser scanning microscopy (LSM). The purpose of this work is to report on a novel benzothiadiazole derivative, namely 4,7-bis(5-((9,9-dioctyl-9H-fluoren-2-yl)ethynyl)thiophen-2-yl)benzo[c][1,2,5]thiadiazole (EFBT) and its optical performance when it is loaded into organic nanostructures intended as labels for LSM. Four different nanostructured labels were prepared: i) EFBT-loaded silica nanoparticles (SiNPs); ii) folate-bioconjugated SiNPs (SiNPs-FA); iii) EFBT-loaded PEGylated nanoparticles (NPs-PEG); and iv) EFBT-loaded folate-terminated PEGylated nanoparticles (NPs-PEG-FA). All these nanostructures are reported through a comparative study of their linear and nonlinear optical properties, including their performance as exogenous label agents in the cervical cancer cell line HeLa. This assessment of the performance of a specific fluorophore loaded into different nanostructured matrices (labels), and fairly compared under the same characterization conditions, including the LSM settings, is less common while previous reports had focused in comparing silica and PEGylated nanoparticles but loaded with different fluorophores. The results show that the internal molecular organization into each type of organic nanostructure impacted differently the properties of EFBT, where the silica matrix tend to preserve the optical performance of the fluorophore by preventing intermolecular interactions; in contrast, PEGylated nanoparticles favored molecular interactions and introduced non-radiative decay channels that degrades drastically the optical performance. Nevertheless, the use of functionalized ends entities produced a better cellular label uptake with PEGylated that with silica nanoparticles. In overall, the NPs-PEG-FA label produced the best HeLa imaging.
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Affiliation(s)
- V Alvarez-Venicio
- Centro de Investigaciones en Óptica A.P. 1-948, 37000 León, Gto., Mexico
| | - R Castro-Beltrán
- Departamento de Ingeniería Física, División de Ciencias e Ingenierías, Universidad de Guanajuato, Loma del Bosque 103, Lomas del Campestre, C.P. 37150, León, Guanajuato, México
| | - G Ramos-Ortiz
- Centro de Investigaciones en Óptica A.P. 1-948, 37000 León, Gto., Mexico.
| | - M Rodríguez
- Centro de Investigaciones en Óptica A.P. 1-948, 37000 León, Gto., Mexico.
| | - J E Alba-Rosales
- Centro de Investigaciones en Óptica A.P. 1-948, 37000 León, Gto., Mexico; Departamento de Ingeniería Física, División de Ciencias e Ingenierías, Universidad de Guanajuato, Loma del Bosque 103, Lomas del Campestre, C.P. 37150, León, Guanajuato, México
| | - G Gutiérrez-Juárez
- Departamento de Ingeniería Física, División de Ciencias e Ingenierías, Universidad de Guanajuato, Loma del Bosque 103, Lomas del Campestre, C.P. 37150, León, Guanajuato, México
| | - R Santillán
- Departamento de Química, Centro de Investigación y de Estudios Avanzados del IPN, 07000, Apdo. Postal. 14-740, México D.F., Mexico
| | - M E Ochoa
- Departamento de Química, Centro de Investigación y de Estudios Avanzados del IPN, 07000, Apdo. Postal. 14-740, México D.F., Mexico
| | - L L Flores-Villavicencio
- Departamento de Biología, División de Ciencias Naturales y Exactas, campus Guanajuato, Universidad de Guanajuato, Guanajuato 36050, Mexico
| | - M Sabanero-López
- Departamento de Biología, División de Ciencias Naturales y Exactas, campus Guanajuato, Universidad de Guanajuato, Guanajuato 36050, Mexico
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3
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Luo T, Warner RL, Sapoznik KA, Walker BR, Burns SA. Template free eye motion correction for scanning systems. OPTICS LETTERS 2021; 46:753-756. [PMID: 33577506 PMCID: PMC8447858 DOI: 10.1364/ol.415285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 12/31/2020] [Indexed: 05/18/2023]
Abstract
Scanning imaging systems are susceptible to image warping in the presence of target motion occurring within the time required to acquire an individual image frame. In this Letter, we introduce the use of a dual raster scanning approach to correct for motion distortion without the need for prior knowledge of the undistorted image. In the dual scanning approach, the target is imaged simultaneously with two imaging beams from the same imaging system. The two imaging beams share a common pupil but have a spatial shift between the beams on the imaging plane. The spatial shift can be used to measure high speed events, because it measures an identical region at two different times within the time required for acquisition of a single frame. In addition, it provides accurate spatial information, since two different regions on the target are imaged simultaneously, providing an undistorted estimate of the spatial relation between regions. These spatial and temporal relations accurately measure target motion. Data from adaptive optics scanning laser ophthalmoscope (AOSLO) imaging of the human retina are used to demonstrate this technique. We apply the technique to correct the shearing of retinal images produced by eye motion. Three control subjects were measured while imaging different retinal layers and retinal locations to qualify the effectiveness of the algorithm. Since the time shift between channels is readily adjustable, this method can be tuned to match different imaging situations. The major requirement is the need to separate the two images; in our case, we used different near infrared spectral regions and dichroic filters.
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Affiliation(s)
- Ting Luo
- Optometry School, Indiana University Bloomington, 800 Atwater Ave., Bloomington, IN 47045
| | - Raymond L. Warner
- Optometry School, Indiana University Bloomington, 800 Atwater Ave., Bloomington, IN 47045
| | - Kaitlyn A Sapoznik
- Optometry School, Indiana University Bloomington, 800 Atwater Ave., Bloomington, IN 47045
| | - Brittany R. Walker
- Optometry School, Indiana University Bloomington, 800 Atwater Ave., Bloomington, IN 47045
| | - Stephen A. Burns
- Optometry School, Indiana University Bloomington, 800 Atwater Ave., Bloomington, IN 47045
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4
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De Simone A, Naldi M, Tedesco D, Bartolini M, Davani L, Andrisano V. Advanced analytical methodologies in Alzheimer’s disease drug discovery. J Pharm Biomed Anal 2020; 178:112899. [DOI: 10.1016/j.jpba.2019.112899] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 09/25/2019] [Accepted: 09/26/2019] [Indexed: 12/13/2022]
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5
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Rowley MI, Coolen ACC, Vojnovic B, Barber PR. Robust Bayesian Fluorescence Lifetime Estimation, Decay Model Selection and Instrument Response Determination for Low-Intensity FLIM Imaging. PLoS One 2016; 11:e0158404. [PMID: 27355322 PMCID: PMC4927071 DOI: 10.1371/journal.pone.0158404] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 06/15/2016] [Indexed: 11/26/2022] Open
Abstract
We present novel Bayesian methods for the analysis of exponential decay data that exploit the evidence carried by every detected decay event and enables robust extension to advanced processing. Our algorithms are presented in the context of fluorescence lifetime imaging microscopy (FLIM) and particular attention has been paid to model the time-domain system (based on time-correlated single photon counting) with unprecedented accuracy. We present estimates of decay parameters for mono- and bi-exponential systems, offering up to a factor of two improvement in accuracy compared to previous popular techniques. Results of the analysis of synthetic and experimental data are presented, and areas where the superior precision of our techniques can be exploited in Förster Resonance Energy Transfer (FRET) experiments are described. Furthermore, we demonstrate two advanced processing methods: decay model selection to choose between differing models such as mono- and bi-exponential, and the simultaneous estimation of instrument and decay parameters.
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Affiliation(s)
- Mark I. Rowley
- Institute for Mathematical and Molecular Biomedicine, King’s College London, London, United Kingdom
| | - Anthonius C. C. Coolen
- Institute for Mathematical and Molecular Biomedicine, King’s College London, London, United Kingdom
| | - Borivoj Vojnovic
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Paul R. Barber
- Institute for Mathematical and Molecular Biomedicine, King’s College London, London, United Kingdom
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
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6
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Brandes AR, Elmaklizi A, Akarçay HG, Kienle A. Modeling the tight focusing of beams in absorbing media with Monte Carlo simulations. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:115003. [PMID: 25393966 DOI: 10.1117/1.jbo.19.11.115003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 10/17/2014] [Indexed: 06/04/2023]
Abstract
A severe drawback to the scalar Monte Carlo (MC) method is the difficulty of introducing diffraction when simulating light propagation. This hinders, for instance, the accurate modeling of beams focused through microscope objectives, where the diffraction patterns in the focal plane are of great importance in various applications. Here, we propose to overcome this issue by means of a direct extinction method. In the MC simulations, the photon paths' initial positions are sampled from probability distributions which are calculated with a modified angular spectrum of the plane waves technique. We restricted our study to the two-dimensional case, and investigated the feasibility of our approach for absorbing yet nonscattering materials. We simulated the focusing of collimated beams with uniform profiles through microscope objectives. Our results were compared with those yielded by independent simulations using the finite-difference time-domain method. Very good agreement was achieved between the results of both methods, not only for the power distributions around the focal region including diffraction patterns, but also for the distribution of the energy flow (Poynting vector).
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Affiliation(s)
- Arnd R Brandes
- Institute for Lasertechnology in Medicine and Metrology, Helmholtzstraße 12, Ulm D-89081, Germany
| | - Ahmed Elmaklizi
- Institute for Lasertechnology in Medicine and Metrology, Helmholtzstraße 12, Ulm D-89081, Germany
| | - H Günhan Akarçay
- Institute for Lasertechnology in Medicine and Metrology, Helmholtzstraße 12, Ulm D-89081, GermanybInstitute of Applied Physics at the University of Bern, Sidlerstrasse 5, Bern CH-3012, Switzerland
| | - Alwin Kienle
- Institute for Lasertechnology in Medicine and Metrology, Helmholtzstraße 12, Ulm D-89081, Germany
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7
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8
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Physico-mechanical characterisation of cells using atomic force microscopy — Current research and methodologies. J Microbiol Methods 2011; 86:131-9. [DOI: 10.1016/j.mimet.2011.05.021] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Revised: 05/18/2011] [Accepted: 05/26/2011] [Indexed: 11/21/2022]
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9
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Chou DR, Bower BA, Wax A. Low-cost, scalable laser scanning module for real-time reflectance and fluorescence confocal microscopy. APPLIED OPTICS 2005; 44:2013-2018. [PMID: 15835349 DOI: 10.1364/ao.44.002013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We present a low-cost, high-speed, retrofitted laser scanning module for microscopy. The cage-mounted system, with various available fiber-coupled sources, offers a real-time imaging alternative to costly commercial systems with capabilities for conventional or confocal reflectance and fluorescence applications as well as advanced laser scanning microscopy implementations. Reflectance images of a resolution target and confocal images of fluorescent polystyrene beads are presented for system characterization. Confocal fluorescence image stacks of T84 epithelial cancer cells are presented to demonstrate application to biological studies. This laser scanning module is a flexible, scalable, high-speed alternative to commercial laser scanning systems suitable for applications requiring a simple imaging tool and for teaching laboratories.
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MESH Headings
- Algorithms
- Cell Line, Tumor
- Colorectal Neoplasms/pathology
- Computer Systems
- Equipment Design
- Equipment Failure Analysis
- Humans
- Image Enhancement/instrumentation
- Image Enhancement/methods
- Image Interpretation, Computer-Assisted/methods
- Microscopy, Confocal/economics
- Microscopy, Confocal/instrumentation
- Microscopy, Confocal/methods
- Microscopy, Fluorescence/economics
- Microscopy, Fluorescence/instrumentation
- Microscopy, Fluorescence/methods
- Phantoms, Imaging
- Reproducibility of Results
- Sensitivity and Specificity
- Signal Processing, Computer-Assisted
- United States
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Affiliation(s)
- Derrick R Chou
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, USA.
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10
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Montag M, Kukulies J, Jörgens R, Gundlach H, Trendelenburg MF, Spring H. Working with the confocal scanning UV-laser microscope: specific DNA localization at high sensitivity and multiple-parameter fluorescence. J Microsc 1991; 163:201-10. [PMID: 1719207 DOI: 10.1111/j.1365-2818.1991.tb03172.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The use of fast-staining DNA-specific dyes such as DAPI or Hoechst 33342/33258 has been a major problem for confocal scanning laser microscopy (CSLM) studies of intranuclear chromatin organization. Moreover, the availability of a confocal ultraviolet scanning laser microscope configuration, which allows an excitation at wavelengths of 364 nm as well as 488, 514 and 543 nm, is a prerequisite for single as well as multiple fluorescence parameter studies, especially if these studies are concerned with the precise localization of intranuclear signals. Here we report the characteristics and application of a CSLM, which was adapted for UV-excitation and therefore enables comparison of the spatial distribution of several types of signals within one preparation. In addition to multiple-parameter studies, we have also investigated the sensitivity of the system with regard to the identification of the double-stranded DNA of lampbrush chromosome loops in germinal vesicles of amphibian oocytes.
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Affiliation(s)
- M Montag
- Gene Structure Unit, German Cancer Research Center, Heidelberg
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11
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Nordén B, Elvingson C, Jonsson M, Akerman B. Microscopic behaviour of DNA during electrophoresis: electrophoretic orientation. Q Rev Biophys 1991; 24:103-64. [PMID: 1924681 DOI: 10.1017/s0033583500003395] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The study of the behaviour of DNA when subjected to electric fields poses several intriguing problems of fundamental physico-chemical importance. Electric field (Kerr effect) orientation of DNA in free solution as well as migration of DNA in gel electrophoresis are two well-established, but so far rather separate, research fields. Whereas the first one has been generally concerned with basic structural and dynamical properties of DNA (Charney, 1988), the second is closely related to techniques of molecular biology (for a review on DNA electrophoresis, see stellwagen 1987).
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Affiliation(s)
- B Nordén
- Department of Physical Chemistry, Chalmers University of Technology, Gothenburg, Sweden
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12
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Abstract
In the past decades a large number of DNA adducts induced in the intact animal by alkylating agents have been identified. The formation and repair of these adducts are important determinants, not only of mutagenesis, tumor initiation and DNA-mediated toxicity but probably also of tumor progression. Most studies on in vivo DNA modification have been performed on isolated bulk DNA. More recently, methods have been developed to study the distribution of DNA adducts at the level of either the individual gene or the individual cell. This paper reviews immunocytochemical methods to study the formation and repair of DNA adducts and other DNA modifications at the level of the individual cell. DNA modifications induced by alkylating agents and a variety of other agents including ultraviolet radiation, aromatic amines, polycyclic aromatic hydrocarbons and platinum anti-cancer drugs will be discussed. Up to now, immunocytochemical analysis of in vivo modified DNA has largely concentrated on experimental animals. These studies have revealed striking heterogeneities with regard to formation and/or repair of DNA adducts in tissues from rat, hamster and mouse. Immunocytochemical adduct analysis can be used to identify in a convenient, fast and detailed way cell types, cell stages and sites in which biological effects of the adducts might be expressed. More recently, immunocytochemical analysis of DNA adducts also proved to be feasible on in situ exposed human samples. A number of existing and potential applications in the field of chemical carcinogenesis, experimental chemotherapy and molecular epidemiology are discussed.
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Affiliation(s)
- L den Engelse
- Division of Chemical Carcinogenesis, Netherlands Cancer Institute, Amsterdam
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13
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Mao C, Johnson KM, Cathey WT. Superresolving phase conjugate scanning microscope. APPLIED OPTICS 1990; 29:3753-3765. [PMID: 20567480 DOI: 10.1364/ao.29.003753] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Analytical and experimental results of a new type of optical scanning microscope, which uses a phase conjugate mirror and pinholes to achieve superresolution, are presented. The phase conjugate scanning microscope has a higher Rayleigh resolution limit and better sectioning discrimination than conventional, single pass, and double pass scanning microscopes. It also can reduce the effect of static and dynamic aberrations on the imaging process, is very easy to align, and has the potential of introducing optical power gain into the system.
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14
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Montag M, Spring H, Trendelenburg MF, Kriete A. Methodical aspects of 3-D reconstruction of chromatin architecture in mouse trophoblast giant nuclei. J Microsc 1990; 158:225-33. [PMID: 2370653 DOI: 10.1111/j.1365-2818.1990.tb02996.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Precise 3-D reconstruction of the spatial organization of murine trophoblast giant-cell chromatin is a prerequisite for detailed investigations on the fine structural changes in chromatin-fibre organization during the trophoblast endomitotic cell cycle. It appears very likely that sequential fine structural changes in the chromatin arrangement are concomitant with the changes in the gene expression pattern of these cells during the early phase of murine gestation. The complex intra-nuclear chromatin organization of mouse trophoblast giant nuclei was investigated in permanent tissue preparations which had been stained with a DNA-specific dye. The spatial chromatin arrangement was examined in fluorescence with a confocal scanning laser microscope. Serial optical sections were recorded and subjected to a computer-based 3-D reconstruction method which is suitable even for very complex biological structures.
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Affiliation(s)
- M Montag
- Institute of Experimental Pathology, German Cancer Research Center, Heidelberg
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15
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Docchio F. Ocular fluorometry: principles, fluorophores, instrumentation, and clinical applications. Lasers Surg Med 1989; 9:515-32. [PMID: 2689819 DOI: 10.1002/lsm.1900090602] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Ocular fluorometry is rapidly evolving as a versatile technique for research and diagnosis in ophthalmology. The main reasons for this increasing success are 1) the ideal characteristics of the eye as an optical device for excitation of tissue fluorescence and for the detection of the fluorescent emission; 2) the development of novel fluorometric techniques, including differential and time-resolved fluorescence spectroscopy; and 3) the increasing use of coupling geometries with high-resolution and high spatial selectivity. Both endogenous and exogenous fluorophores are of interest to ocular fluorometry. The most significant among endogenous fluorophores are the fluorescing pigments of the lens and of the retinal pigment epithelium (RPE). The nature, topography, and fluorescence properties of such pigments depend on age and pathology and on the level of light exposure. Exogenous fluorophores of interest are both intentionally induced and unintentionally accumulated drugs (some of which are phototoxic). Laser-based fluorometric techniques play a leading role in ocular fluorometry. The peculiar properties of the laser for the excitation of fluorescence make this source a favorite candidate for ocular fluorometry both in vitro and in vivo.
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Affiliation(s)
- F Docchio
- Dipartimento di Automazione Industriale, Università degli Studi di Brescia, Mompiano, Italy
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