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Examination of intestinal ultrastructure, bowel wall apoptosis and tight junctions in the early phase of sepsis. Sci Rep 2020; 10:11507. [PMID: 32661347 PMCID: PMC7359326 DOI: 10.1038/s41598-020-68109-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 06/17/2020] [Indexed: 12/17/2022] Open
Abstract
Gut hyperpermeability can be caused by either apoptosis of the intestinal epithelium or altered status, permeability or porosity of tight junctions. This project aims to elucidate these mechanisms in the early phase of sepsis. Eighteen male wild type mice were randomized to two groups. All mice received one single gavage of fluorescein isothiocyanate (FITC) dextran 30 min before intervention. One group (n = 10) underwent cecal ligation and puncture to induce sepsis. The other group (n = 8) was sham operated. Septic animals exhibited significantly increased permeability for FITC 8 h post-operatively. Significantly increased serum interleukin-6, tumor-necrosis-factor-alpha and interleukin-1-beta confirmed sepsis. Septic animals showed significant bowel wall inflammation of ileum and colon samples. PCR revealed significantly increased expression of claudin-2 and decreased expressions of claudin-4, tight-junction-protein-1 and occludin-1 resembling increased permeability of tight junctions. However, these alterations could not be confirmed at the protein level. Light microscopy revealed significant dilatation of intercellular spaces at the basal sections of intestinal epithelial cells (IEC) in septic animals confirmed by increased intercellular spaces at the level of tight junctions and adherens junctions in electron microscopy (TEM). In small angle X-ray scattering no increase in number or size of nanopores could be shown in the bowel wall. HOECHST staining and PCR of ileum samples for apoptosis markers proofed no relevant differences in intestinal epithelial cell apoptosis between the groups. Intestinal hyperpermeability in septic animals was most likely caused by alterations of the intercellular contacts and not by apoptosis or increased size/number of nanopores of intestinal epithelial cells in this murine model of early sepsis.
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Alam N, Choi M, Ghammraoui B, Dahal E, Badano A. Small-angle x-ray scattering cross-section measurements of imaging materials. Biomed Phys Eng Express 2017. [DOI: 10.1088/2057-1976/aa6720] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Arboleda C, Wang Z, Koehler T, Martens G, Van Stevendaal U, Bartels M, Villanueva-Perez P, Roessl E, Stampanoni M. Sensitivity-based optimization for the design of a grating interferometer for clinical X-ray phase contrast mammography. OPTICS EXPRESS 2017; 25:6349-6364. [PMID: 28380987 DOI: 10.1364/oe.25.006349] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
An X-ray grating interferometer (GI) suitable for clinical mammography must comply with quite strict dose, scanning time and geometry limitations, while being able to detect tumors, microcalcifications and other abnormalities. Such a design task is not straightforward, since obtaining optimal phase-contrast and dark-field signals with clinically compatible doses and geometrical constraints is remarkably challenging. In this work, we present a wave propagation based optimization that uses the phase and dark-field sensitivities as figures of merit. This method was used to calculate the optimal interferometer designs for a commercial mammography setup. Its accuracy was validated by measuring the visibility of polycarbonate samples of different thicknesses on a Talbot-Lau interferometer installed on this device and considering some of the most common grating imperfections to be able to reproduce the experimental values. The optimization method outcomes indicate that small grating pitches are required to boost sensitivity in such a constrained setup and that there is a different optimal scenario for each signal type.
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Allec N, Choi M, Yesupriya N, Szychowski B, White MR, Kann MG, Garcin ED, Daniel MC, Badano A. Small-angle X-ray scattering method to characterize molecular interactions: Proof of concept. Sci Rep 2015; 5:12085. [PMID: 26160052 PMCID: PMC4498188 DOI: 10.1038/srep12085] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 05/28/2015] [Indexed: 11/24/2022] Open
Abstract
Characterizing biomolecular interactions is crucial to the understanding of biological processes. Existing characterization methods have low spatial resolution, poor specificity, and some lack the capability for deep tissue imaging. We describe a novel technique that relies on small-angle X-ray scattering signatures from high-contrast molecular probes that correlate with the presence of biomolecular interactions. We describe a proof-of-concept study that uses a model system consisting of mixtures of monomer solutions of gold nanoparticles (GNPs) as the non-interacting species and solutions of GNP dimers linked with an organic molecule (dimethyl suberimidate) as the interacting species. We report estimates of the interaction fraction obtained with the proposed small-angle X-ray scattering characterization method exhibiting strong correlation with the known relative concentration of interacting and non-interacting species.
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Affiliation(s)
- Nicholas Allec
- Division of Imaging, Diagnostics, and Software Reliability, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| | - Mina Choi
- Division of Imaging, Diagnostics, and Software Reliability, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland, USA
| | - Nikhil Yesupriya
- Division of Imaging, Diagnostics, and Software Reliability, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| | - Brian Szychowski
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Maryland, USA
| | - Michael R. White
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Maryland, USA
| | - Maricel G. Kann
- Department of Biological Sciences, University of Maryland, Baltimore County, Maryland, USA
| | - Elsa D. Garcin
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Maryland, USA
| | - Marie-Christine Daniel
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Maryland, USA
| | - Aldo Badano
- Division of Imaging, Diagnostics, and Software Reliability, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
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Vedantham S, Shi L, Karellas A. Large-angle x-ray scatter in Talbot-Lau interferometry for breast imaging. Phys Med Biol 2014; 59:6387-400. [PMID: 25295630 DOI: 10.1088/0031-9155/59/21/6387] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Monte Carlo simulations were used to investigate large-angle x-ray scatter at design energy of 25 keV during small field of view (9.6 cm × 5 cm) differential phase contrast imaging of the breast using Talbot-Lau interferometry. Homogenous, adipose and fibroglandular breasts of uniform thickness ranging from 2 to 8 cm encompassing the field of view were modeled. Theoretically determined transmission efficiencies of the gratings were used to validate the Monte Carlo simulations, followed by simulations to determine the x-ray scatter reaching the detector. The recorded x-ray scatter was classified into x-ray photons that underwent at least one Compton interaction (incoherent scatter) and Rayleigh interaction alone (coherent scatter) for further analysis. Monte Carlo based estimates of transmission efficiencies showed good correspondence [Formula: see text] with theoretical estimates. Scatter-to-primary ratio increased with increasing breast thickness, ranging from 0.11 to 0.22 for 2-8 cm thick adipose breasts and from 0.12 to 0.28 for 2-8 cm thick fibroglandular breasts. The analyzer grating reduced incoherent scatter by ~18% for 2 cm thick adipose breast and by ~35% for 8 cm thick fibroglandular breast. Coherent scatter was the dominant contributor to the total scatter. Coherent-to-incoherent scatter ratio ranged from 2.2 to 3.1 for 2-8 cm thick adipose breasts and from 2.7 to 3.4 for 2-8 cm thick fibroglandular breasts.
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Affiliation(s)
- Srinivasan Vedantham
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
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Feye-Treimer U, Treimer W. Phase-based x-ray scattering--a possible method to detect cancer cells in a very early stage. Med Phys 2014; 41:053503. [PMID: 24784409 DOI: 10.1118/1.4871616] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE This theoretical work contains a detailed investigation of the potential and sensitivity of phase-based x-ray scattering for cancer detection in biopsies if cancer is in a very early stage of development. METHODS Cancer cells in their early stage of development differ from healthy ones mainly due to their faster growing cell nuclei and the enlargement of their densities. This growth is accompanied by an altered nucleus-plasma relation for the benefit of the cell nuclei, that changes the physical properties especially the index of refraction of the cell and the one of the cell nuclei. Interaction of radiation with matter is known to be highly sensitive to small changes of the index of refraction of matter; therefore a detection of such changes of volume and density of cell nuclei by means of high angular resolved phase-based scattering of x rays might provide a technique to distinguish malignant cells from healthy ones if the cell-cell nucleus system is considered as a coherent phase shifting object. Then one can observe from a thin biopsy which represents a monolayer of cells (no multiple scattering) that phase-based x-ray scattering curves from healthy cells differ from those of cancer cells in their early stage of development. RESULTS Detailed calculations of x-ray scattering patterns from healthy and cancer cell nuclei yield graphs and numbers with which one can distinguish healthy cells from cancer ones, taking into account that both kinds of cells occur in a tissue within a range of size and density. One important result is the role and the influence of the (lateral) coherence width of the radiation on the scattering curves and the sensitivity of phase-based scattering for cancer detection. A major result is that a larger coherence width yields a larger sensitivity for cancer detection. Further import results are calculated limits for critical sizes and densities of cell nuclei in order to attribute the investigated tissue to be healthy or diseased. CONCLUSIONS With this proposed method it should be in principle possible to detect cancer cells in apparently healthy tissues in biopsies and/or in samples of the far border region of abscised or excised tissues. Thus this method could support established methods in diagnostics of cancer-suspicious samples.
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Affiliation(s)
- U Feye-Treimer
- Department of Mathematics, Physics and Chemistry, University of Applied Sciences, D-13353 Berlin, Germany and Joint Department G-GTOMO, Helmholtz Zentrum fuer Materialien und Energie Berlin, D-14109 Berlin, Germany
| | - W Treimer
- Department of Mathematics, Physics and Chemistry, University of Applied Sciences, D-13353 Berlin, Germany and Joint Department G-GTOMO, Helmholtz Zentrum fuer Materialien und Energie Berlin, D-14109 Berlin, Germany
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Bravin A, Coan P, Suortti P. X-ray phase-contrast imaging: from pre-clinical applications towards clinics. Phys Med Biol 2012; 58:R1-35. [PMID: 23220766 DOI: 10.1088/0031-9155/58/1/r1] [Citation(s) in RCA: 379] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Phase-contrast x-ray imaging (PCI) is an innovative method that is sensitive to the refraction of the x-rays in matter. PCI is particularly adapted to visualize weakly absorbing details like those often encountered in biology and medicine. In past years, PCI has become one of the most used imaging methods in laboratory and preclinical studies: its unique characteristics allow high contrast 3D visualization of thick and complex samples even at high spatial resolution. Applications have covered a wide range of pathologies and organs, and are more and more often performed in vivo. Several techniques are now available to exploit and visualize the phase-contrast: propagation- and analyzer-based, crystal and grating interferometry and non-interferometric methods like the coded aperture. In this review, covering the last five years, we will give an overview of the main theoretical and experimental developments and of the important steps performed towards the clinical implementation of PCI.
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Affiliation(s)
- Alberto Bravin
- European Synchrotron Radiation Facility, 6 rue Horowitz, 38043 Grenoble Cedex, France.
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Kitchen MJ, Paganin DM, Uesugi K, Allison BJ, Lewis RA, Hooper SB, Pavlov KM. X-ray phase, absorption and scatter retrieval using two or more phase contrast images. OPTICS EXPRESS 2010; 18:19994-20012. [PMID: 20940891 DOI: 10.1364/oe.18.019994] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We have developed two phase-retrieval techniques for analyser-based phase contrast imaging that provide information about an object's X-ray absorption, refraction and scattering properties. The first requires rocking curves to be measured with and without the sample and improves upon existing techniques by accurately fitting the curves with Pearson type VII functions. The second employs an iterative approach using two simultaneously recorded images by exploiting the Laue crystal geometry. This technique provides a substantial reduction in X-ray dose and enables quantitative phase retrieval to be performed on images of moving objects.
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