1
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Besnard C, Marie A, Sasidharan S, Buček P, Walker JM, Parker JE, Spink MC, Harper RA, Marathe S, Wanelik K, Moxham TE, Salvati E, Ignatyev K, Kłosowski MM, Shelton RM, Landini G, Korsunsky AM. Multi-resolution Correlative Ultrastructural and Chemical Analysis of Carious Enamel by Scanning Microscopy and Tomographic Imaging. ACS Appl Mater Interfaces 2023; 15:37259-37273. [PMID: 37524079 PMCID: PMC10416148 DOI: 10.1021/acsami.3c08031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 07/17/2023] [Indexed: 08/02/2023]
Abstract
Caries, a major global disease associated with dental enamel demineralization, remains insufficiently understood to devise effective prevention or minimally invasive treatment. Understanding the ultrastructural changes in enamel is hampered by a lack of nanoscale characterization of the chemical spatial distributions within the dental tissue. This leads to the requirement to develop techniques based on various characterization methods. The purpose of the present study is to demonstrate the strength of analytic methods using a correlative technique on a single sample of human dental enamel as a specific case study to test the accuracy of techniques to compare regions in enamel. The science of the different techniques is integrated to genuinely study the enamel. The hierarchical structures within carious tissue were mapped using the combination of focused ion beam scanning electron microscopy with synchrotron X-ray tomography. The chemical changes were studied using scanning X-ray fluorescence (XRF) and X-ray wide-angle and small-angle scattering using a beam size below 80 nm for ångström and nanometer length scales. The analysis of XRF intensity gradients revealed subtle variations of Ca intensity in carious samples in comparison with those of normal mature enamel. In addition, the pathways for enamel rod demineralization were studied using X-ray ptychography. The results show the chemical and structural modification in carious enamel with differing locations. These results reinforce the need for multi-modal approaches to nanoscale analysis in complex hierarchically structured materials to interpret the changes of materials. The approach establishes a meticulous correlative characterization platform for the analysis of biomineralized tissues at the nanoscale, which adds confidence in the interpretation of the results and time-saving imaging techniques. The protocol demonstrated here using the dental tissue sample can be applied to other samples for statistical study and the investigation of nanoscale structural changes. The information gathered from the combination of methods could not be obtained with traditional individual techniques.
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Affiliation(s)
- Cyril Besnard
- MBLEM,
Department of Engineering Science, University
of Oxford, Parks Road, Oxford, Oxfordshire OX1
3PJ, U.K.
| | - Ali Marie
- MBLEM,
Department of Engineering Science, University
of Oxford, Parks Road, Oxford, Oxfordshire OX1
3PJ, U.K.
| | - Sisini Sasidharan
- MBLEM,
Department of Engineering Science, University
of Oxford, Parks Road, Oxford, Oxfordshire OX1
3PJ, U.K.
| | - Petr Buček
- TESCAN-UK
Ltd., Wellbrook Court, Girton, Cambridge CB3 0NA, U.K.
| | | | - Julia E. Parker
- Diamond
Light Source Ltd., Didcot, Oxfordshire OX11 0DE, U.K.
| | | | - Robert A. Harper
- School
of Dentistry, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham, West Midlands B5 7EG, U.K.
| | | | - Kaz Wanelik
- Diamond
Light Source Ltd., Didcot, Oxfordshire OX11 0DE, U.K.
| | - Thomas E.J. Moxham
- MBLEM,
Department of Engineering Science, University
of Oxford, Parks Road, Oxford, Oxfordshire OX1
3PJ, U.K.
- Diamond
Light Source Ltd., Didcot, Oxfordshire OX11 0DE, U.K.
| | - Enrico Salvati
- MBLEM,
Department of Engineering Science, University
of Oxford, Parks Road, Oxford, Oxfordshire OX1
3PJ, U.K.
| | | | | | - Richard M. Shelton
- School
of Dentistry, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham, West Midlands B5 7EG, U.K.
| | - Gabriel Landini
- School
of Dentistry, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham, West Midlands B5 7EG, U.K.
| | - Alexander M. Korsunsky
- MBLEM,
Department of Engineering Science, University
of Oxford, Parks Road, Oxford, Oxfordshire OX1
3PJ, U.K.
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2
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Besnard C, Marie A, Sasidharan S, Harper RA, Marathe S, Moffat J, Shelton RM, Landini G, Korsunsky AM. Time-Lapse In Situ 3D Imaging Analysis of Human Enamel Demineralisation Using X-ray Synchrotron Tomography. Dent J (Basel) 2023; 11:dj11050130. [PMID: 37232781 DOI: 10.3390/dj11050130] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 04/14/2023] [Accepted: 04/19/2023] [Indexed: 05/27/2023] Open
Abstract
Caries is a chronic disease that causes the alteration of the structure of dental tissues by acid dissolution (in enamel, dentine and cementum) and proteolytic degradation (dentine and cementum) and generates an important cost of care. There is a need to visualise and characterise the acid dissolution process on enamel due to its hierarchical structure leading to complex structural modifications. The process starts at the enamel surface and progresses into depth, which necessitates the study of the internal enamel structure. Artificial demineralisation is usually employed to simulate the process experimentally. In the present study, the demineralisation of human enamel was studied using surface analysis carried out with atomic force microscopy as well as 3D internal analysis using synchrotron X-ray tomography during acid exposure with repeated scans to generate a time-lapse visualisation sequence. Two-dimensional analysis from projections and virtual slices and 3D analysis of the enamel mass provided details of tissue changes at the level of the rods and inter-rod substance. In addition to the visualisation of structural modifications, the rate of dissolution was determined, which demonstrated the feasibility and usefulness of these techniques. The temporal analysis of enamel demineralisation is not limited to dissolution and can be applied to other experimental conditions for the analysis of treated enamel or remineralisation.
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Affiliation(s)
- Cyril Besnard
- MBLEM, Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK
| | - Ali Marie
- MBLEM, Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK
| | - Sisini Sasidharan
- MBLEM, Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK
| | - Robert A Harper
- School of Dentistry, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham B5 7EG, UK
| | | | - Jonathan Moffat
- Oxford Instruments Asylum Research, High Wycombe HP12 3SE, UK
| | - Richard M Shelton
- School of Dentistry, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham B5 7EG, UK
| | - Gabriel Landini
- School of Dentistry, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham B5 7EG, UK
| | - Alexander M Korsunsky
- MBLEM, Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK
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3
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Lioliou G, Roche i Morgó O, Marathe S, Wanelik K, Cipiccia S, Olivo A, Hagen CK. Cycloidal-spiral sampling for three-modal x-ray CT flyscans with two-dimensional phase sensitivity. Sci Rep 2022; 12:21336. [PMID: 36494470 PMCID: PMC9734192 DOI: 10.1038/s41598-022-25999-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 12/07/2022] [Indexed: 12/13/2022] Open
Abstract
We present a flyscan compatible acquisition scheme for three-modal X-Ray Computed Tomography (CT) with two-dimensional phase sensitivity. Our approach is demonstrated using a "beam tracking" setup, through which a sample's attenuation, phase (refraction) and scattering properties can be measured from a single frame, providing three complementary contrast channels. Up to now, such setups required the sample to be stepped at each rotation angle to sample signals at an adequate rate, to prevent resolution losses, anisotropic resolution, and under-sampling artefacts. However, the need for stepping necessitated a step-and-shoot implementation, which is affected by motors' overheads and increases the total scan time. By contrast, our proposed scheme, by which continuous horizontal and vertical translations of the sample are integrated with its rotation (leading to a "cycloidal-spiral" trajectory), is fully compatible with continuous scanning (flyscans). This leads to greatly reduced scan times while largely preserving image quality and isotropic resolution.
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Affiliation(s)
- G. Lioliou
- grid.83440.3b0000000121901201Department of Medical Physics and Biomedical Engineering, University College London, Malet Place, London, WC1E 6BT UK
| | - O. Roche i Morgó
- grid.83440.3b0000000121901201Department of Medical Physics and Biomedical Engineering, University College London, Malet Place, London, WC1E 6BT UK
| | - S. Marathe
- grid.18785.330000 0004 1764 0696Diamond Light Source, Harwell Science and Innovation Campus, Fermi Avenue, Didcot, OX11 0DE UK
| | - K. Wanelik
- grid.18785.330000 0004 1764 0696Diamond Light Source, Harwell Science and Innovation Campus, Fermi Avenue, Didcot, OX11 0DE UK
| | - S. Cipiccia
- grid.83440.3b0000000121901201Department of Medical Physics and Biomedical Engineering, University College London, Malet Place, London, WC1E 6BT UK
| | - A. Olivo
- grid.83440.3b0000000121901201Department of Medical Physics and Biomedical Engineering, University College London, Malet Place, London, WC1E 6BT UK
| | - C. K. Hagen
- grid.83440.3b0000000121901201Department of Medical Physics and Biomedical Engineering, University College London, Malet Place, London, WC1E 6BT UK
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4
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Massimi L, Clark SJ, Marussi S, Doherty A, Shah SM, Schulz J, Marathe S, Rau C, Endrizzi M, Lee PD, Olivo A. Time resolved in-situ multi-contrast X-ray imaging of melting in metals. Sci Rep 2022; 12:12136. [PMID: 35840749 PMCID: PMC9287332 DOI: 10.1038/s41598-022-15501-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 06/24/2022] [Indexed: 11/30/2022] Open
Abstract
In this work, the application of a time resolved multi-contrast beam tracking technique to the investigation of the melting and solidification process in metals is presented. The use of such a technique allows retrieval of three contrast channels, transmission, refraction and dark-field, with millisecond time resolution. We investigated different melting conditions to characterize, at a proof-of-concept level, the features visible in each of the contrast channels. We found that the phase contrast channel provides a superior visibility of the density variations, allowing the liquid metal pool to be clearly distinguished. Refraction and dark-field were found to highlight surface roughness formed during solidification. This work demonstrates that the availability of the additional contrast channels provided by multi-contrast X-ray imaging delivers additional information, also when imaging high atomic number specimens with a significant absorption.
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Affiliation(s)
- Lorenzo Massimi
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK.
| | - Samuel J Clark
- Department of Mechanical Engineering, University College London, Gower St, London, WC1E 6BT, UK.,X-ray Science Division, Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL, USA
| | - Sebastian Marussi
- Department of Mechanical Engineering, University College London, Gower St, London, WC1E 6BT, UK
| | - Adam Doherty
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Saurabh M Shah
- Department of Mechanical Engineering, University College London, Gower St, London, WC1E 6BT, UK
| | - Joachim Schulz
- MicroWorks GmbH, Schnetzlerstraße 9, 76137, Karlsruhe, Germany.,Institute of Microstructure Technology, Karlsruhe Institute of Technology, 76021, Karlsruhe, Germany
| | | | - Christoph Rau
- Diamond Light Source, Harwell Oxford Campus, OX11 0DE, Didcot, UK
| | - Marco Endrizzi
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Peter D Lee
- Department of Mechanical Engineering, University College London, Gower St, London, WC1E 6BT, UK
| | - Alessandro Olivo
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
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5
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Metilli L, Storm M, Marathe S, Lazidis A, Marty-Terrade S, Simone E. Application of X-ray Microcomputed Tomography for the Static and Dynamic Characterization of the Microstructure of Oleofoams. Langmuir 2022; 38:1638-1650. [PMID: 35050635 PMCID: PMC8812118 DOI: 10.1021/acs.langmuir.1c03318] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 01/06/2022] [Indexed: 06/14/2023]
Abstract
Oleofoams are a novel, versatile, and biocompatible soft material that finds application in drug, cosmetic or nutraceuticals delivery. However, due to their temperature-sensitive and opaque nature, the characterization of oleofoams' microstructure is challenging. Here, synchrotron X-ray microcomputed tomography and radiography are applied to study the microstructure of a triglyceride-based oleofoam. These techniques enable non-destructive, quantitative, 3D measurements of native samples to determine the thermodynamic and kinetic behavior of oleofoams at different stages of their life cycle. During processing, a constant bubble size distribution is reached after few minutes of shearing, while the number of bubbles incorporated keeps increasing until saturation of the continuous phase. Low amounts of solid triglycerides in oleofoams allow faster aeration and a more homogeneous microstructure but lower thermodynamic stability, with bubble disproportionation and shape relaxation over time. Radiography shows that heating causes Ostwald ripening and coalescence of bubbles, with an increase of their diameter and sphericity.
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Affiliation(s)
- Lorenzo Metilli
- School
of Food Science and Nutrition, Food Colloids and Bioprocessing group, University of Leeds, Woodhouse Lane, Leeds LS29JT, U.K.
| | - Malte Storm
- Diamond
Light Source Ltd., Harwell Science and Innovation
Campus, Didcot OX110DE, U.K.
- Helmholtz-Zentrum
hereon, Max-Planck-Str 1, 21502 Geesthacht, Germany
| | - Shashidhara Marathe
- Diamond
Light Source Ltd., Harwell Science and Innovation
Campus, Didcot OX110DE, U.K.
| | - Aris Lazidis
- Nestlé
Product Technology Centre Confectionery, Haxby Road, York YO31 8TA, U.K.
| | | | - Elena Simone
- School
of Food Science and Nutrition, Food Colloids and Bioprocessing group, University of Leeds, Woodhouse Lane, Leeds LS29JT, U.K.
- Department
of Applied Science and Technology (DISAT), Politecnico di Torino, Corso Duca degli Abruzzi 24, Torino 10129, Italy
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6
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Kasi SG, Dhir SK, Shah A, Shivananda S, Verma S, Marathe S, Chatterjee K, Agarwalla S, Srirampur S, Kalyani S, Pemde HK, Balasubramanian S, Basavaraja GV, Parekh BJ, Kumar R, Gupta P. Coronavirus Disease 2019 (COVID-19) Vaccination for Children: Position Statement of Indian Academy of Pediatrics Advisory Committee on Vaccination and Immunization Practices. Indian Pediatr 2022; 59:51-57. [PMID: 34927603 PMCID: PMC8821846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/01/2023]
Abstract
JUSTIFICATION Data generated after the first wave has revealed that some children with coronavirus 19 (COVID-19) can become seriously ill. Multi-inflammatory syndrome in children (MIS-C) and long COVID cause significant morbidity in children. Prolonged school closures and quarantine have played havoc with the psychosocial health of children. Many countries in the world have issued emergency use authorisation (EUA) of selected Covid-19 vaccines for use in children. In India, a Subject Expert Committee (SEC) has recommended the use of Covaxin (Bharat Biotech) for children from the ages of 2-18 years. The recommendation has been given to the Drugs Controller General of India (DCGI) for final approval. OBJECTIVE To provide an evidence-based document to guide the pediatricians on the recommendation to administer COVID vaccines to children, as and when they are available for use. PROCESS Formulation of key questions was done by the committee, followed by review of literature on epidemiology and burden of Covid-19 in children, review of the studies on COVID vaccines in children, and the IAP stand on Covid-19 vaccination in children. The available data was discussed in the ACVIP focused WhatsApp group followed by an online meeting on 24 October, 2021, wherein the document was discussed in detail and finalized. RECOMMENDATIONS The IAP supports the Government of India's decision to extend the COVID-19 vaccination program to children between 2-18 years of age. Children with high-risk conditions may be immunized on a priority basis. The IAP and its members should be a partner with the Government of India, in the implementation of this program and the surveillance that is necessary following the roll-out.
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Affiliation(s)
- Srinivas G Kasi
- Kasi Clinic, 2nd Cross, 3rd Block, Jayanagar, Bengaluru, Karnataka. Correspondence to: Dr Srinivas G Kasi, Convener, ACVIP of IAP, Kasi Clinic, 2nd Cross, 3rd Block, Jayanagar, Bengaluru, Karnataka.
| | - Shashi Kant Dhir
- Department of Pediatrics, Guru Gobind Singh Medical College, Faridkot, Punjab
| | - Abhay Shah
- Dr Abhay K Shah Children Hospital, Ahmedabad, Gujarat
| | - S Shivananda
- Department of Pediatrics, Fortis Hospital, Banneraghatta Road, Bengaluru, Karnataka
| | - Sanjay Verma
- Division of Infectious Diseases, Department of Pediatrics, PGIMER, Chandigarh
| | - S Marathe
- Marathe Child Care Hospital, Nagpur, Maharashtra
| | | | - Sunil Agarwalla
- Department of Pediatrics, SCB Medical College and Hospital, Cuttack, Odisha
| | - Sanjay Srirampur
- Department of Pediatrics, Aditya Super Speciality Hospital, Hyderabad, Telangana
| | - Srinivas Kalyani
- Department of Pediatrics, Niloufer Hospital, Osmania Medical College, Hyderabad, Telangana
| | - Harish K Pemde
- Department of Pediatrics, Lady Hardinge Medical College, New Delhi
| | - S Balasubramanian
- Department of Pediatrics, Kanchi Kamakoti Childs Trust Hospital, Chennai, Tamil Nadu
| | | | | | | | - Piyush Gupta
- Department of Pediatrics, University College of Medical Sciences, New Delhi
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7
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Tran J, Marathe S, Stefanutti G, Alphonso N, Venugopal P. Outcomes of Paediatric Patients Needing Laparotomy During Extra-Corporeal Membrane Oxygenation. Heart Lung Circ 2022. [DOI: 10.1016/j.hlc.2022.06.414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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8
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Yaldo F, Sharma B, Marathe S, Alphonso N, Powell J, Venugopal P. The Embryological Basis for Anomalous Origin of Branch Pulmonary Arteries. Heart Lung Circ 2022. [DOI: 10.1016/j.hlc.2022.06.419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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9
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Storm M, Döring F, Marathe S, Cipiccia S, David C, Rau C. Optimizing the energy bandwidth for transmission full-field X-ray microscopy experiments. J Synchrotron Radiat 2022; 29:138-147. [PMID: 34985431 PMCID: PMC8733970 DOI: 10.1107/s1600577521011206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 10/25/2021] [Indexed: 06/14/2023]
Abstract
Full-field transmission X-ray microscopy (TXM) is a very potent high-resolution X-ray imaging technique. However, it is challenging to achieve fast acquisitions because of the limited efficiency of the optics. Using a broader energy bandwidth, for example using a multilayer monochromator, directly increases the flux in the experiment. The advantage of more counts needs to be weighed against a deterioration in achievable resolution because focusing optics show chromatic aberrations. This study presents theoretical considerations of how much the resolution is affected by an increase in bandwidth as well as measurements at different energy bandwidths (ΔE/E = 0.013%, 0.27%, 0.63%) and the impact on achievable resolution. It is shown that using a multilayer monochromator instead of a classical silicon double-crystal monochromator can increase the flux by an order of magnitude with only a limited effect on the resolution.
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Affiliation(s)
- Malte Storm
- Diamond Light Source Ltd, Didcot OX11 0DE, United Kingdom
| | - Florian Döring
- Paul Scherrer Institut, Forschungsstrasse 111, 5232 Villigen PSI, Switzerland
| | | | | | - Christian David
- Paul Scherrer Institut, Forschungsstrasse 111, 5232 Villigen PSI, Switzerland
| | - Christoph Rau
- Diamond Light Source Ltd, Didcot OX11 0DE, United Kingdom
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10
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Suna J, Alphonso N, Venugopal P, Marathe S, Justo R, Merlo G. Stakeholder Preferences for Paediatric Cardiac Surgery Outcome Reporting in Australia and New Zealand. Heart Lung Circ 2022. [DOI: 10.1016/j.hlc.2022.06.417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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11
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Kasi SG, Dhir SK, Shah A, Shivananda S, Verma S, Marathe S, Chatterjee K, Agarwalla S, Srirampur S, Kalyani S, Pemde HK, Balasubramanian S, Basavaraja GV, Parekh BJ, Kumar R, Gupta P. Coronavirus Disease 2019 (COVID-19) Vaccination for Children: Position Statement of Indian Academy of Pediatrics Advisory Committee on Vaccination and Immunization Practices. Indian Pediatr 2021. [PMID: 34927603 PMCID: PMC8821846 DOI: 10.1007/s13312-022-2421-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Justification Data generated after the first wave has revealed that some children with Coronavirus 19 (COVID-19) can become seriously ill. Multi-inflammatory syndrome in children (MIS-C) and long COVID cause significant morbidity in children. Prolonged school closures and quarantine have played havoc with the psychosocial health of children. Many countries in the world have issued emergency use authorisation (EUA) of selected COVID-19 vaccines for use in children. In India, a Subject Expert Committee (SEC) has recommended the use of Covaxin (Bharat Biotech) for children from the ages of 2–18 years. The recommendation has been given to the Drugs Controller General of India (DCGI) for final approval. Objective To provide an evidence-based document to guide the pediatricians on the recommendation to administer COVID vaccines to children, as and when they are available for use. Process Formulation of key questions was done by the committee, followed by review of literature on epidemiology and burden of COVID-19 in children, review of the studies on COVID vaccines in children, and the IAP stand on COVID-19 vaccination in children. The available data was discussed in the ACVIP focused WhatsApp group followed by an online meeting on 24 October, 2021, wherein the document was discussed in detail and finalized. Recommendations The IAP supports the Government of India’s decision to extend the COVID-19 vaccination program to children between 2–18 years of age. Children with high-risk conditions may be immunized on a priority basis. The IAP and its members should be a partner with the Government of India, in the implementation of this program and the surveillance that is necessary following the roll-out.
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Affiliation(s)
- Srinivas G Kasi
- Kasi Clinic, 2nd Cross, 3rd Block, Jayanagar, Bengaluru, Karnataka. Correspondence to: Dr Srinivas G Kasi, Convener, ACVIP of IAP, Kasi Clinic, 2nd Cross, 3rd Block, Jayanagar, Bengaluru, Karnataka.
| | - Shashi Kant Dhir
- Department of Pediatrics, Guru Gobind Singh Medical College, Faridkot, Punjab
| | - Abhay Shah
- Dr Abhay K Shah Children Hospital, Ahmedabad, Gujarat
| | - S Shivananda
- Department of Pediatrics, Fortis Hospital, Banneraghatta Road, Bengaluru, Karnataka
| | - Sanjay Verma
- Division of Infectious Diseases, Department of Pediatrics, PGIMER, Chandigarh
| | - S Marathe
- Marathe Child Care Hospital, Nagpur, Maharashtra
| | | | - Sunil Agarwalla
- Department of Pediatrics, SCB Medical College and Hospital, Cuttack, Odisha
| | - Sanjay Srirampur
- Department of Pediatrics, Aditya Super Speciality Hospital, Hyderabad, Telangana
| | - Srinivas Kalyani
- Department of Pediatrics, Niloufer Hospital, Osmania Medical College, Hyderabad, Telangana
| | - Harish K Pemde
- Department of Pediatrics, Lady Hardinge Medical College, New Delhi
| | - S Balasubramanian
- Department of Pediatrics, Kanchi Kamakoti Childs Trust Hospital, Chennai, Tamil Nadu
| | | | | | | | - Piyush Gupta
- Department of Pediatrics, University College of Medical Sciences, New Delhi
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12
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Massimi L, Clark SJ, Marussi S, Doherty A, Schulz J, Marathe S, Rau C, Endrizzi M, Lee PD, Olivo A. Dynamic Multicontrast X-Ray Imaging Method Applied to Additive Manufacturing. Phys Rev Lett 2021; 127:215503. [PMID: 34860108 DOI: 10.1103/physrevlett.127.215503] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 07/06/2021] [Accepted: 10/12/2021] [Indexed: 06/13/2023]
Abstract
We present a dynamic implementation of the beam-tracking x-ray imaging method providing absorption, phase, and ultrasmall angle scattering signals with microscopic resolution and high frame rate. We demonstrate the method's ability to capture dynamic processes with 22-ms time resolution by investigating the melting of metals in laser additive manufacturing, which has so far been limited to single-modality synchrotron radiography. The simultaneous availability of three contrast channels enables earlier segmentation of droplets, tracking of powder dynamic, and estimation of unfused powder amounts, demonstrating that the method can provide additional information on melting processes.
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Affiliation(s)
- Lorenzo Massimi
- Department of Medical Physics and Biomedical Engineering, University College London, Gower St, London WC1E 6BT, United Kingdom
| | - Samuel J Clark
- Department of Mechanical Engineering, University College London, Gower St, London WC1E 6BT, United Kingdom
| | - Sebastian Marussi
- Department of Mechanical Engineering, University College London, Gower St, London WC1E 6BT, United Kingdom
| | - Adam Doherty
- Department of Medical Physics and Biomedical Engineering, University College London, Gower St, London WC1E 6BT, United Kingdom
| | - Joachim Schulz
- MicroWorks GmbH, Schnetzlerstrae 9, 76137 Karlsruhe, Germany
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany
| | - Shashidhara Marathe
- Diamond Light Source, Harwell Oxford Campus, OX11 0DE Didcot, United Kingdom
| | - Christoph Rau
- Diamond Light Source, Harwell Oxford Campus, OX11 0DE Didcot, United Kingdom
| | - Marco Endrizzi
- Department of Medical Physics and Biomedical Engineering, University College London, Gower St, London WC1E 6BT, United Kingdom
| | - Peter D Lee
- Department of Mechanical Engineering, University College London, Gower St, London WC1E 6BT, United Kingdom
| | - Alessandro Olivo
- Department of Medical Physics and Biomedical Engineering, University College London, Gower St, London WC1E 6BT, United Kingdom
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13
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Perna A, Marathe S, Dreos R, Falquet L, Akarsu Egger H, Auber LA. Revealing NOTCH-dependencies in synaptic targets associated with Alzheimer's disease. Mol Cell Neurosci 2021; 115:103657. [PMID: 34314836 DOI: 10.1016/j.mcn.2021.103657] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 07/14/2021] [Accepted: 07/18/2021] [Indexed: 11/28/2022] Open
Abstract
Recent studies have identified NOTCH signaling as a contributor of neurodegeneration including Alzheimer's disease' (AD) pathophysiology. As part of the efforts to understand molecular mechanisms and players involved in neurodegenerative dementia, we employed transgenic mouse models with Notch1 and Rbpjk loss of function (LOF) mutation in pyramidal neurons of the CA fields. Using RNA-seq, we have investigated the differential expression of NOTCH-dependent genes either upon environmental enrichment (EE) or upon kainic acid (KA) injury. We found a substantial genetic diversity in absence of both NOTCH1 receptor or RBPJK transcriptional activator. Among differentially expressed genes, we observed a significant upregulation of Gabra2a in both knockout models, suggesting a role for NOTCH signaling in the modulation of E/I balance. Upon excitotoxic stimulation, loss of RBPJK results in decreased expression of synaptic proteins with neuroprotective effects. We confirmed Nptx2, Npy, Pdch8, TncC as direct NOTCH1/RBPJK targets and Bdnf and Scg2 as indirect targets. Finally, we translate these findings into human entorhinal cortex containing the hippocampal region from AD patients performing targeted transcripts analysis. We observe an increased trend for RBPJK and the ligand DNER starting in the mild-moderate stage of the disease with no change of NOTCH1 expression. Alongside, expression of the Notch targets Hes5 and Hey1 tend to rise in the intermediate stage of the disease and drop in severe AD. Similarly the newly discovered NOTCH targets, NPTX2, NPY, BDNF show an up-warding tendency during the mild-moderate stage, and decline in the severe phase of the disease. This study identifies NOTCH as a central signaling cascade capable of modulating synaptic transmission in response to excitatory insult through the activation of neuroprotective genes that have been associated to AD.
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Affiliation(s)
- A Perna
- Section of Medicine, Department NMS, University of Fribourg, Fribourg, Switzerland
| | - S Marathe
- Centre for Neuroscience, Indian Institute of Science, Bangalore, India
| | - R Dreos
- Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland
| | - L Falquet
- Biochemistry Unit, University of Fribourg and Swiss Institute of Bioinformatics, Fribourg, Switzerland
| | - H Akarsu Egger
- Biochemistry Unit, University of Fribourg and Swiss Institute of Bioinformatics, Fribourg, Switzerland
| | - L Alberi Auber
- Section of Medicine, Department NMS, University of Fribourg, Fribourg, Switzerland; Swiss Integrative Center for Human Health, Fribourg, Switzerland.
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14
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Orchard J, Miedecke A, Rahiman S, Lally E, Justo R, Suna J, Marathe S, Alphonso N, Venugopal P. Early Recovery With a Fast-Track Program: Initial Experience in Paediatric Cardiac Surgery. Heart Lung Circ 2021. [DOI: 10.1016/j.hlc.2021.06.357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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15
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Marathe S, Shah J, Shikata F, Suna J, Patukale A, Justo R, Alphonso N, Venugopal P. Partial Upper Sternal Pplit for Paediatric Cardiac Surgery: Preliminary Experience. Heart Lung Circ 2021. [DOI: 10.1016/j.hlc.2021.06.361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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16
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Stenehjem D, Lubinga S, King S, Betts K, Rao S, Castriota F, Mahin M, Orvis E, Marathe S, Ma J. 1316P Trial-based costs of all-cause adverse events in first-line therapy for advanced non-small cell lung cancer: Findings from CheckMate-9LA. Ann Oncol 2020. [DOI: 10.1016/j.annonc.2020.08.1630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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17
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Barui S, Ding H, Wang Z, Zhao H, Marathe S, Mirihanage W, Basu B, Derby B. Probing Ink-Powder Interactions during 3D Binder Jet Printing Using Time-Resolved X-ray Imaging. ACS Appl Mater Interfaces 2020; 12:34254-34264. [PMID: 32567300 PMCID: PMC7467558 DOI: 10.1021/acsami.0c03572] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 06/22/2020] [Indexed: 06/11/2023]
Abstract
Capillary-driven ink infiltration through a porous powder bed in three-dimensional (3D) binder jet printing (inkjet printing onto a powder bed) controls the printing resolution and as-printed "green" strength of the resulting object. However, a full understanding of the factors controlling the kinetics of the infiltration remains incomplete. Here, high-resolution in situ synchrotron radiography provides time-resolved imaging of the penetration of an aqueous solution of eythylene glycol through a porous alumina powder bed, used as a model system. A static drop-on-demand inkjet printer was used to dispense liquid droplets onto a powder surface. The subsequent migration of the liquid front and its interactions with powder particles were tracked using fast synchrotron X-radiography in the Diamond Synchrotron, with phase-contrast imaging at a frame rate of 500 Hz. Image processing and analysis reveal that both the time-dependent increment in the wetting area and the propagation of the "interface leading edge" exhibit heterogeneous behavior in both temporal and spatial domains. However, mean infiltration kinetics are shown to be consistent with existing infiltration models based on the Washburn equation modified to account for the spreading of the liquid drop on the powder surface and using a modified term for the bed porosity.
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Affiliation(s)
- Srimanta Barui
- Department
of Materials, University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
- Laboratory
for Biomaterials and Translational Center on Biomaterials for Orthopedic
and Dental Applications, Materials Research Centre, Indian Institute of Science, Bangalore 560012, India
| | - Hui Ding
- Department
of Materials, University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - Zixin Wang
- Department
of Materials, University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - Hu Zhao
- Department
of Materials, University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | | | - Wajira Mirihanage
- Department
of Materials, University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - Bikramjit Basu
- Laboratory
for Biomaterials and Translational Center on Biomaterials for Orthopedic
and Dental Applications, Materials Research Centre, Indian Institute of Science, Bangalore 560012, India
| | - Brian Derby
- Department
of Materials, University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
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18
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Kumar S, Dhamija B, Marathe S, Karulkar A, Sharma N, Jain H, Purwar R. 889 Interleukin-9 promotes malignant T cell survival by inhibiting oxidative stress and lactic acidosis in cutaneous T cell lymphoma. J Invest Dermatol 2020. [DOI: 10.1016/j.jid.2020.03.905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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19
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Cao J, Marathe S, Zannino D, Celermajer D, Justo R, Alphonso N, d'Udekem Y, Winlaw D. 042 Challenging the “Ten Commandments” – Early Age at Fontan is not a Risk Factor for Long-Term Failure. Heart Lung Circ 2020. [DOI: 10.1016/j.hlc.2020.09.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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20
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Marathe S, Perumal G, Wildschut J, Mattke A, Morwood J, Venugopal P, Alphonso N. Use of Temporary Epicardial Pacing Wires After Congenital Heart Surgery: Necessity or Luxury? Heart Lung Circ 2018. [DOI: 10.1016/j.hlc.2018.06.758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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21
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22
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Olatinwo MB, Ham K, McCarney J, Marathe S, Ge J, Knapp G, Butler LG. Recent applications of X-ray grating interferometry imaging to evaluate flame retardancy performance of brominated flame retardant. Polym Degrad Stab 2017. [DOI: 10.1016/j.polymdegradstab.2017.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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23
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Marathe S, Shi X, Wojcik MJ, Macrander AT, Assoufid L. Measurement of X-ray Beam Coherence along Multiple Directions Using 2-D Checkerboard Phase Grating. J Vis Exp 2016. [PMID: 27768076 DOI: 10.3791/53025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
A procedure for a technique to measure the transverse coherence of synchrotron radiation X-ray sources using a single phase grating interferometer is reported. The measurements were demonstrated at the 1-BM bending magnet beamline of the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). By using a 2-D checkerboard π/2 phase-shift grating, transverse coherence lengths were obtained along the vertical and horizontal directions as well as along the 45° and 135° directions to the horizontal direction. Following the technical details specified in this paper, interferograms were measured at different positions downstream of the phase grating along the beam propagation direction. Visibility values of each interferogram were extracted from analyzing harmonic peaks in its Fourier Transformed image. Consequently, the coherence length along each direction can be extracted from the evolution of visibility as a function of the grating-to-detector distance. The simultaneous measurement of coherence lengths in four directions helped identify the elliptical shape of the coherence area of the Gaussian-shaped X-ray source. The reported technique for multiple-direction coherence characterization is important for selecting the appropriate sample size and orientation as well as for correcting the partial coherence effects in coherence scattering experiments. This technique can also be applied for assessing coherence preserving capabilities of X-ray optics.
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Affiliation(s)
- Shashidhara Marathe
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory; Division of Science, Diamond Light Source Ltd
| | - Xianbo Shi
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory
| | - Michael J Wojcik
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory
| | - Albert T Macrander
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory
| | - Lahsen Assoufid
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory;
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24
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Assoufid L, Shi X, Marathe S, Benda E, Wojcik MJ, Lang K, Xu R, Liu W, Macrander AT, Tischler JZ. Development and implementation of a portable grating interferometer system as a standard tool for testing optics at the Advanced Photon Source beamline 1-BM. Rev Sci Instrum 2016; 87:052004. [PMID: 27250384 DOI: 10.1063/1.4950775] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 04/25/2016] [Indexed: 06/05/2023]
Abstract
We developed a portable X-ray grating interferometer setup as a standard tool for testing optics at the Advanced Photon Source (APS) beamline 1-BM. The interferometer can be operated in phase-stepping, Moiré, or single-grating harmonic imaging mode with 1-D or 2-D gratings. All of the interferometer motions are motorized; hence, it is much easier and quicker to switch between the different modes of operation. A novel aspect of this new instrument is its designed portability. While the setup is designed to be primarily used as a standard tool for testing optics at 1-BM, it could be potentially deployed at other APS beamlines for beam coherence and wavefront characterization or imaging. The design of the interferometer system is described in detail and coherence measurements obtained at the APS 34-ID-E beamline are presented. The coherence was probed in two directions using a 2-D checkerboard, a linear, and a circular grating at X-ray energies of 8 keV, 11 keV, and 18 keV.
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Affiliation(s)
- Lahsen Assoufid
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Xianbo Shi
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Shashidhara Marathe
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Erika Benda
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Michael J Wojcik
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Keenan Lang
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Ruqing Xu
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Wenjun Liu
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Albert T Macrander
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Jon Z Tischler
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
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25
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Olatinwo MB, Ham K, McCarney J, Marathe S, Ge J, Knapp G, Butler LG. Analysis of Flame Retardancy in Polymer Blends by Synchrotron X-ray K-edge Tomography and Interferometric Phase Contrast Movies. J Phys Chem B 2016; 120:2612-24. [DOI: 10.1021/acs.jpcb.5b12775] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mutairu B. Olatinwo
- Department
of Chemistry, Louisiana State University, 232 Choppin Hall, Baton Rouge, Louisiana 70803, United States
| | - Kyungmin Ham
- Center for Advanced Microstructures & Devices, Louisiana State University, 6980 Jefferson Highway, Baton Rouge, Louisiana 70806, United States
| | - Jonathan McCarney
- Albemarle Corporation,
Process Development Center, P.O. Box 341, Baton
Rouge, Louisiana 70821, United States
| | - Shashidhara Marathe
- Advanced
Photon Source, Argonne National Laboratory, Building 401, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Jinghua Ge
- Center
for Computation and Technology, Louisiana State University, 340
East Parker Boulevard, Baton Rouge, Louisiana 70808, United States
| | - Gerry Knapp
- Department
of Mechanical and Industrial Engineering, Louisiana State University, Baton
Rouge, Louisiana 70803, United States
| | - Leslie G. Butler
- Department
of Chemistry, Louisiana State University, 232 Choppin Hall, Baton Rouge, Louisiana 70803, United States
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26
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Pelliccia D, Vaz R, Svalbe I, Morgan KS, Marathe S, Xiao X, Assoufid L, Anderson RA, Topczewski J, Bryson-Richardson RJ. Comparison of different numerical treatments for x-ray phase tomography of soft tissue from differential phase projections. Phys Med Biol 2015; 60:3065-80. [PMID: 25802946 DOI: 10.1088/0031-9155/60/8/3065] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
X-ray imaging of soft tissue is made difficult by their low absorbance. The use of x-ray phase imaging and tomography can significantly enhance the detection of these tissues and several approaches have been proposed to this end. Methods such as analyzer-based imaging or grating interferometry produce differential phase projections that can be used to reconstruct the 3D distribution of the sample refractive index. We report on the quantitative comparison of three different methods to obtain x-ray phase tomography with filtered back-projection from differential phase projections in the presence of noise. The three procedures represent different numerical approaches to solve the same mathematical problem, namely phase retrieval and filtered back-projection. It is found that obtaining individual phase projections and subsequently applying a conventional filtered back-projection algorithm produces the best results for noisy experimental data, when compared with other procedures based on the Hilbert transform. The algorithms are tested on simulated phantom data with added noise and the predictions are confirmed by experimental data acquired using a grating interferometer. The experiment is performed on unstained adult zebrafish, an important model organism for biomedical studies. The method optimization described here allows resolution of weak soft tissue features, such as muscle fibers.
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27
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Marathe S, Liu S, Brai E, Kaczarowski M, Alberi L. Notch signaling in response to excitotoxicity induces neurodegeneration via erroneous cell cycle reentry. Cell Death Differ 2015; 22:1775-84. [PMID: 25822340 DOI: 10.1038/cdd.2015.23] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Revised: 01/26/2015] [Accepted: 02/11/2015] [Indexed: 02/06/2023] Open
Abstract
Neurological disorders such as Alzheimer's disease, stroke and epilepsy are currently marred by the lack of effective treatments to prevent neuronal death. Erroneous cell cycle reentry (CCR) is hypothesized to have a causative role in neurodegeneration. We show that forcing S-phase reentry in cultured hippocampal neurons is sufficient to induce neurodegeneration. We found that kainic-acid treatment in vivo induces erroneous CCR and neuronal death through a Notch-dependent mechanism. Ablating Notch signaling in neurons provides neuroprotection against kainic acid-induced neuronal death. We further show that kainic-acid treatment activates Notch signaling, which increases the bioavailability of CyclinD1 through Akt/GSK3β pathway, leading to aberrant CCR via activation of CyclinD1-Rb-E2F1 axis. In addition, pharmacological blockade of this pathway at critical steps is sufficient to confer resistance to kainic acid-induced neurotoxicity in mice. Taken together, our results demonstrate that excitotoxicity leads to neuronal death in a Notch-dependent manner through erroneous CCR.
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Affiliation(s)
- S Marathe
- Department of Medicine, Institute of Anatomy, University of Fribourg, Fribourg, Switzerland
| | - S Liu
- Receptor Biology Section, NINDS/NIH, Bethesda, MD, USA
| | - E Brai
- Department of Medicine, Institute of Anatomy, University of Fribourg, Fribourg, Switzerland
| | - M Kaczarowski
- Department of Medicine, Institute of Anatomy, University of Fribourg, Fribourg, Switzerland
| | - L Alberi
- Department of Medicine, Institute of Anatomy, University of Fribourg, Fribourg, Switzerland
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28
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Kujala N, Marathe S, Shu D, Shi B, Qian J, Maxey E, Finney L, Macrander A, Assoufid L. Kirkpatrick-Baez mirrors to focus hard X-rays in two dimensions as fabricated, tested and installed at the Advanced Photon Source. J Synchrotron Radiat 2014; 21:662-668. [PMID: 24971959 DOI: 10.1107/s1600577514006493] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 03/24/2014] [Indexed: 06/03/2023]
Abstract
The micro-focusing performance for hard X-rays of a fixed-geometry elliptical Kirkpatrick-Baez (K-B) mirrors assembly fabricated, tested and finally implemented at the micro-probe beamline 8-BM of the Advanced Photon Source is reported. Testing of the K-B mirror system was performed at the optics and detector test beamline 1-BM. K-B mirrors of length 80 mm and 60 mm were fabricated by profile coating with Pt metal to produce focal lengths of 250 mm and 155 mm for 3 mrad incident angle. For the critical angle of Pt, a broad bandwidth of energies up to 20 keV applies. The classical K-B sequential mirror geometry was used, and mirrors were mounted on micro-translation stages. The beam intensity profiles were measured by differentiating the curves of intensity data measured using a wire-scanning method. A beam size of 1.3 µm (V) and 1.2 µm (H) was measured with monochromatic X-rays of 18 keV at 1-BM. After installation at 8-BM the measured focus met the design requirements. In this paper the fabrication and metrology of the K-B mirrors are reported, as well as the focusing performances of the full mirrors-plus-mount set-up at both beamlines.
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Affiliation(s)
- Naresh Kujala
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439, USA
| | - Shashidhara Marathe
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439, USA
| | - Deming Shu
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439, USA
| | - Bing Shi
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439, USA
| | - Jun Qian
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439, USA
| | - Evan Maxey
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439, USA
| | - Lydia Finney
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439, USA
| | - Albert Macrander
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439, USA
| | - Lahsen Assoufid
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439, USA
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29
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Marathe S, Shi X, Wojcik MJ, Kujala NG, Divan R, Mancini DC, Macrander AT, Assoufid L. Probing transverse coherence of x-ray beam with 2-D phase grating interferometer. Opt Express 2014; 22:14041-14053. [PMID: 24977503 PMCID: PMC4083056 DOI: 10.1364/oe.22.014041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 05/08/2014] [Accepted: 05/08/2014] [Indexed: 06/03/2023]
Abstract
Transverse coherence of the x-ray beam from a bending magnet source was studied along multiple directions using a 2-D π/2 phase grating by measuring interferogram visibilities at different distances behind the grating. These measurements suggest that the preferred measuring orientation of a 2-D checkerboard grating is along the diagonal directions of the square blocks, where the interferograms have higher visibility and are not sensitive to the deviation of the duty cycle of the grating period. These observations are verified by thorough wavefront propagation simulations. The accuracy of the measured coherence values was also validated by the simulation and analytical results obtained from the source parameters. In addition, capability of the technique in probing spatially resolved local transverse coherence is demonstrated.
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Affiliation(s)
- Shashidhara Marathe
- Advanced Photon Source, Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL 60439, USA
| | - Xianbo Shi
- Advanced Photon Source, Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL 60439, USA
| | - Michael J. Wojcik
- Advanced Photon Source, Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL 60439, USA
| | - Naresh G. Kujala
- Advanced Photon Source, Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL 60439, USA
| | - Ralu Divan
- Center for Nanoscale Materials, Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL 60439, USA
| | - Derrick C. Mancini
- PSE / Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL 60439, USA
| | - Albert T. Macrander
- Advanced Photon Source, Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL 60439, USA
| | - Lahsen Assoufid
- Advanced Photon Source, Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL 60439, USA
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30
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Marathe S, Assoufid L, Xiao X, Ham K, Johnson WW, Butler LG. Improved algorithm for processing grating-based phase contrast interferometry image sets. Rev Sci Instrum 2014; 85:013704. [PMID: 24517772 DOI: 10.1063/1.4861199] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Grating-based X-ray and neutron interferometry tomography using phase-stepping methods generates large data sets. An improved algorithm is presented for solving for the parameters to calculate transmissions, differential phase contrast, and dark-field images. The method takes advantage of the vectorization inherent in high-level languages such as Mathematica and MATLAB and can solve a 16 × 1k × 1k data set in less than a second. In addition, the algorithm can function with partial data sets. This is demonstrated with processing of a 16-step grating data set with partial use of the original data chosen without any restriction. Also, we have calculated the reduced chi-square for the fit and notice the effect of grating support structural elements upon the differential phase contrast image and have explored expanded basis set representations to mitigate the impact.
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Affiliation(s)
- Shashidhara Marathe
- Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, Illinois 60439, USA
| | - Lahsen Assoufid
- Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, Illinois 60439, USA
| | - Xianghui Xiao
- Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, Illinois 60439, USA
| | | | - Warren W Johnson
- Department of Physics and Astronomy, LSU, Baton Rouge, Louisiana 70803, USA
| | - Leslie G Butler
- Department of Chemistry, LSU, Baton Rouge, Louisiana 70803, USA
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31
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Abstract
We present a reflection based coherent diffraction imaging method which can be used to reconstruct a non periodic surface image from a diffraction amplitude measured in reflection geometry. Using a He-Ne laser, we demonstrated that a surface image can be reconstructed solely from the reflected intensity from a surface without relying on any prior knowledge of the sample object or the object support. The reconstructed phase image of the exit wave is particularly interesting since it can be used to obtain quantitative information of the surface depth profile or the phase change during the reflection process. We believe that this work will broaden the application areas of coherent diffraction imaging techniques using light sources with limited penetration depth.
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Affiliation(s)
- Shashidhara Marathe
- Department of Materials Science and Engineering & Nano-bio Materials and Electronics, Gwangju Institute of Science and Technology, Gwangju, 500-712 Korea
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32
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Abstract
INTRODUCTION Breast gangrene has been reported as a complication following puerperal sepsis, breast surgery, nipple piercings, warfarin toxicity, etc. We report a case of primary breast gangrene in an HIV-positive individual which, to the best of our knowledge, is the first of its kind. CASE REPORT A 40-year-old previously healthy woman presented with fulminating left breast gangrene. She was detected to be HIV positive. Mastectomy was performed. The detailed management of the condition is discussed. CONCLUSION Severe necrotising infections may be initial manifestations of HIV infection and patients with such infections should be screened for HIV.
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Affiliation(s)
- V Venkatramani
- Department of Surgery, Seth GS Medical College and KEM Hospital, Parel, Mumbai, India.
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Chimanpure J, Ashtaputre S, Marathe S, Hebalkar N, Kharrazi S, Pasricha R, Kulkarni SK. Synthesis and Characterization of Mercaptoethanol Capped Zinc Oxide Nanoparticles Capped with Organic Molecules. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/15533170500471748] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- J. Chimanpure
- a Department of Physics , University of Pune , Pune, India
| | - S. Ashtaputre
- a Department of Physics , University of Pune , Pune, India
| | - S. Marathe
- a Department of Physics , University of Pune , Pune, India
| | - N. Hebalkar
- a Department of Physics , University of Pune , Pune, India
| | - S. Kharrazi
- a Department of Physics , University of Pune , Pune, India
| | - Renu Pasricha
- b National Chemical Laboratory , Pashan, Pune, India
| | - S. K. Kulkarni
- a Department of Physics , University of Pune , Pune, India
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Lee G, Tsiriopoulos I, Marathe S, Smith R, Crisp J. Non seminomatous germ cell tumour of a solitary testis in a 70-year-old man: a rare case. Int Urol Nephrol 2005; 37:533-4. [PMID: 16307337 DOI: 10.1007/s11255-005-2090-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
We report a rare case of a 70-year-old patient who presented with undifferentiated malignant teratoma arising from a solitary testis. The literature review highlights the rarity of such tumour in this age group, and this may represent the oldest reported patient with non seminomatous germ cell tumour of testicle.
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Affiliation(s)
- G Lee
- Watford General Hospital, WD18 0HB, London, UK.
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Lee G, Marathe S, Sabbagh S, Crisp J. Thermo-expandable Intra-prostatic Stent in the Treatment of Acute Urinary Retention in Elderly Patients with Significant Co-morbidities. Int Urol Nephrol 2005; 37:501-4. [PMID: 16307329 DOI: 10.1007/s11255-005-2091-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
We assess the use of thermo-expandable intra-prostatic stent (Memokath, Engineers and Doctors A/S, Denmark) for the treatment of acute urinary retention (AUR) in men with significant co-morbidities for transurethral resection of prostate (TURP). We evaluate the pre- and post-operative complications, duration of stents in-situ and patients quality of life after the stent insertion. Patients with significant co-morbidities presenting with AUR were selected, who were unfit for TURP. The co-morbidities included ischaemic heart disease, congestive heart failure, and chronic obstructive pulmonary disease. The exclusion criteria were bladder tumour and atonic bladder. The Memokath stents were inserted using a flexible cystoscope under local anaesthesia. The patients were followed up at 3 and 6 months after the procedure and the ones who remained alive were asked to complete self-administered questionnaires and IPSS scores. Fifteen men with acute urinary retention were recruited for stent insertion with the mean age of 87 years. No peri-operative complications were recorded. Three patients died after the insertion with functional Memokath in-situ. Nine patients had good functioning stents post-operatively, and remain catheter free up to 30 months after the procedure. The mean duration of stent life was 18 months. Three long-term complications were detected, including stent migration and prostate overgrowth. The Memokath is a good option for frail elderly patients presenting with AUR. The procedure is safe and has minimal long term complications. The stent also provides a sustained good quality of life for patients and avoids the necessity of long term catheterisation.
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Affiliation(s)
- G Lee
- Watford General Hospital, WD18 0HB, Watford, UK.
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Marathe S, Mohandas TP, Sivaram S. Polymerization of 2-Allylnorbornane Using Ziegler-Natta Catalysts: Copolymerization with Ethylene. Macromolecules 2002. [DOI: 10.1021/ma00126a005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Damodaran A, Malathi A, Patil N, Shah N, Marathe S. Therapeutic potential of yoga practices in modifying cardiovascular risk profile in middle aged men and women. J Assoc Physicians India 2002; 50:633-40. [PMID: 12186115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
AIMS OF STUDY To study effect of yoga on the physiological, psychological well being, psychomotor parameter and modifying cardiovascular risk factors in mild to moderate hypertensive patients. METHODS Twenty patients (16 males, 4 females) in the age group of 35 to 55 years with mild to moderate essential hypertension underwent yogic practices daily for one hour for three months. Biochemical, physiological and psychological parameters were studied prior and following period of three months of yoga practices, biochemical parameters included, blood glucose, lipid profile, catecholmines, MDA, Vit. C cholinesterase and urinary VMA. Psychological evaluation was done by using personal orientation inventory and subjective well being. RESULTS Results showed decrease in blood pressure and drug score modifying risk factors, i.e. blood glucose, cholesterol and triglycerides decreased overall improvement in subjective well being and quality of life. There was decrease in VMA catecholamine, and decrease MDA level suggestive decrease sympathetic activity and oxidant stress. CONCLUSION Yoga can play an important role in risk modification for cardiovascular diseases in mild to moderate hypertension.
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Affiliation(s)
- A Damodaran
- Bhabha Atomic Research Centre, Medical Division Mumbai
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Marathe S, Choi Y, Leventhal AR, Tabas I. Sphingomyelinase converts lipoproteins from apolipoprotein E knockout mice into potent inducers of macrophage foam cell formation. Arterioscler Thromb Vasc Biol 2000; 20:2607-13. [PMID: 11116060 DOI: 10.1161/01.atv.20.12.2607] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The apoE knockout (E0) mouse is one of the most widely used animal models of atherosclerosis, and there may be similarities to chylomicron remnant-induced atherosclerosis in humans. Although the lesions of these mice contain large numbers of cholesteryl ester (CE)-laden macrophages (foam cells), E0 plasma lipoproteins are relatively weak inducers of cholesterol esterification in macrophages. Previous in vivo work has suggested that arterial wall sphingomyelinase (SMase) may promote atherogenesis in the E0 mouse, perhaps by inducing subendothelial lipoprotein aggregation and subsequent foam cell formation. The goal of the present study was to test the hypothesis that the modification of E0 lipoproteins by SMase converts these lipoproteins into potent inducers of macrophage foam cell formation. When d<1.063 E0 lipoproteins were pretreated with SMase and then incubated with E0 macrophages, cellular CE mass and stimulation of the cholesterol esterification pathway were increased approximately 5-fold compared with untreated lipoproteins. SMase-treated E0 lipoproteins were more potent stimulators of cholesterol esterification than either E0 lipoproteins in the presence of lipoprotein lipases or oxidized E0 lipoproteins. The uptake and degradation of SMase-treated E0 lipoproteins by macrophages were saturable and specific and substantially inhibited by partial proteolysis of cell-surface proteins. Uptake and degradation were diminished by an anti-apoB antibody and by competition with human S(f) 100-400 hypertriglyceridemic VLDL, raising the possibility that a receptor that recognizes apoB-48 might be involved. In conclusion, SMase-modification of E0 lipoproteins, a process previously shown to occur in lesions, may be an important mechanism for foam cell formation in this widely studied model of atherosclerosis. Moreover, the findings in this report may provide important clues regarding the atherogenicity of chylomicron remnants in humans.
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Affiliation(s)
- S Marathe
- Department of Medicine, Columbia University, New York, NY 10032, USA
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Marathe S, Miranda SR, Devlin C, Johns A, Kuriakose G, Williams KJ, Schuchman EH, Tabas I. Creation of a mouse model for non-neurological (type B) Niemann-Pick disease by stable, low level expression of lysosomal sphingomyelinase in the absence of secretory sphingomyelinase: relationship between brain intra-lysosomal enzyme activity and central nervous system function. Hum Mol Genet 2000; 9:1967-76. [PMID: 10942425 DOI: 10.1093/hmg/9.13.1967] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Most lysosomal storage diseases result in neurodegeneration, but deficiencies in the same enzymes can also lead to syndromes without neurologic manifestations. The hypothesis that low levels of residual, intra-lysosomal enzymatic activities in the central nervous system (CNS) are protective has been difficult to prove because of inconsistencies in assays of tissue samples. Experimental correction of lysosomal enzyme deficiencies in animal models suggests that low-level enzymatic activity may reduce CNS pathology, but these results are difficult to interpret owing to the partial and transient nature of the improvements, the presence of secretory hydrolases, and other confounding factors. Using a novel transgenic/knockout strategy to manipulate the intracellular targeting of a hydrolase, we created a mouse that stably expresses low levels of lysosomal sphingomyelinase (L-SMase) in the complete absence of secretory sphingomyelinase (S-SMase). The brains of these mice exhibited 11.5-18.2% of wild-type L-SMase activity, but the cerebellar Purkinje cell layer, which is lost by 4 months of age in mice completely lacking L- and S-SMase, was preserved for at least 8 months. The L-SMase activities in other organs were 1-14% of wild-type levels, and by 8 months of age all peripheral organs had accumulated sphingomyelin and demonstrated pathological intracellular inclusions. Most importantly, L-SMase-expressing mice showed no signs of the severe neurologic disease observed in completely deficient mice, and their life span and general health were essentially normal. These findings show that stable, continuous, low-level expression of intra-lysosomal enzyme activity in the brain can preserve CNS function in the absence of secretory enzyme or other confounding factors.
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Affiliation(s)
- S Marathe
- Departments of Medicine and Anatomy and Cell Biology, Columbia University, New York, NY 10032, USA
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Wong ML, Xie B, Beatini N, Phu P, Marathe S, Johns A, Gold PW, Hirsch E, Williams KJ, Licinio J, Tabas I. Acute systemic inflammation up-regulates secretory sphingomyelinase in vivo: a possible link between inflammatory cytokines and atherogenesis. Proc Natl Acad Sci U S A 2000; 97:8681-6. [PMID: 10890909 PMCID: PMC27008 DOI: 10.1073/pnas.150098097] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2000] [Indexed: 11/18/2022] Open
Abstract
Inflammation plays a critical role in atherogenesis, yet the mediators linking inflammation to specific atherogenic processes remain to be elucidated. One such mediator may be secretory sphingomyelinase (S-SMase), a product of the acid sphingomyelinase gene. The secretion of S-SMase by cultured endothelial cells is induced by inflammatory cytokines, and in vivo data have implicated S-SMase in subendothelial lipoprotein aggregation, macrophage foam cell formation, and possibly other atherogenic processes. Thus, the goal of this study was to seek evidence for S-SMase regulation in vivo during a physiologically relevant inflammatory response. First, wild-type mice were injected with saline or lipopolysaccharide (LPS) as a model of acute systemic inflammation. Serum S-SMase activity 3 h postinjection was increased 2- to 2.5-fold by LPS (P < 0.01). To determine the role of IL-1 in the LPS response, we used IL-1 converting enzyme knockout mice, which exhibit deficient IL-1 bioactivity. The level of serum S-SMase activity in LPS-injected IL-1 converting enzyme knockout mice was approximately 35% less than that in identically treated wild-type mice (P < 0.01). In LPS-injected IL-1-receptor antagonist knockout mice, which have an enhanced response to IL-1, serum S-SMase activity was increased 1. 8-fold compared with LPS-injected wild-type mice (P < 0.01). Finally, when wild-type mice were injected directly with IL-1beta, tumor necrosis factor alpha, or both, serum S-SMase activity increased 1. 6-, 2.3-, and 2.9-fold, respectively (P < 0.01). These data show regulation of S-SMase activity in vivo and they raise the possibility that local stimulation of S-SMase may contribute to the effects of inflammatory cytokines in atherosclerosis.
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Affiliation(s)
- M L Wong
- Department of Psychiatry and Biobehavioral Sciences, University of California, School of Medicine, Los Angeles, CA 90095-1761, USA
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Tabas I, Marathe S, Kuriakose G, Williams K, Tribble D. Secretory sphingomyelinase and atherosclerosis. Atherosclerosis 2000. [DOI: 10.1016/s0021-9150(00)80396-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Marathe S, Kuriakose G, Williams KJ, Tabas I. Sphingomyelinase, an enzyme implicated in atherogenesis, is present in atherosclerotic lesions and binds to specific components of the subendothelial extracellular matrix. Arterioscler Thromb Vasc Biol 1999; 19:2648-58. [PMID: 10559007 DOI: 10.1161/01.atv.19.11.2648] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Atherosclerotic lesions contain an extracellular sphingomyelinase (SMase) activity that hydrolyzes the sphingomyelin of subendothelial low density lipoprotein (LDL). This SMase activity may promote atherosclerosis by enhancing subendothelial LDL retention and aggregation, foam cell formation, and possibly other atherogenic processes. The results of recent cell-culture studies have led to the hypothesis that a specific molecule called secretory SMase (S-SMase) is responsible for the SMase activity known to be in lesions, although its presence in atheromata had not been examined directly. Herein we provide immunohistochemical and biochemical support for this hypothesis. First, 2 different antibodies against S-SMase detected extracellular immunoreactive protein in the intima of mouse, rabbit, and human atherosclerotic lesions. Much of this material in lesions appeared in association with the subendothelial matrix. Second, binding studies in vitro demonstrated that (125)I-S-SMase adheres to the extracellular matrix of cultured aortic smooth muscle and endothelial cells, specifically to the laminin and collagen components. Third, in its bound state, S-SMase retains substantial enzymatic activity against lipoprotein substrates. Overall, these data support the hypothesis that S-SMase is an extracellular arterial wall SMase that contributes to the hydrolysis of the sphingomyelin of subendothelial LDL. S-SMase may therefore be an important participant in atherogenesis through local enzymatic effects that stimulate subendothelial retention and aggregation of atherogenic lipoproteins.
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MESH Headings
- Animals
- Aorta/cytology
- Arteriosclerosis/enzymology
- Arteriosclerosis/etiology
- Cattle
- Cells, Cultured
- Chondroitin Sulfates/metabolism
- Chondroitin Sulfates/pharmacology
- Collagen/metabolism
- Collagen/pharmacology
- Dermatan Sulfate/metabolism
- Dermatan Sulfate/pharmacology
- Endothelium, Vascular/cytology
- Endothelium, Vascular/enzymology
- Extracellular Matrix Proteins/metabolism
- Female
- Fibronectins/metabolism
- Fibronectins/pharmacology
- Heparin/metabolism
- Heparin/pharmacology
- Humans
- Iodine Radioisotopes
- Laminin/analysis
- Laminin/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/enzymology
- Protein Binding/physiology
- Rabbits
- Serum Albumin, Bovine/metabolism
- Serum Albumin, Bovine/pharmacology
- Sphingomyelin Phosphodiesterase/analysis
- Sphingomyelin Phosphodiesterase/metabolism
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Affiliation(s)
- S Marathe
- Departments of Medicine and Anatomy & Cell Biology, Columbia University, New York, NY 10032, USA
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Marathe S, Yu YG, Turner GE, Palmier C, Weiss RL. Multiple forms of arginase are differentially expressed from a single locus in Neurospora crassa. J Biol Chem 1998; 273:29776-85. [PMID: 9792692 DOI: 10.1074/jbc.273.45.29776] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Neurospora crassa catabolic enzyme, arginase (L-arginine amidinohydrolase, EC 3.5.3.1), exists in multiple forms. Multiple forms of arginase are found in many vertebrates, but this is the only reported example in a microbial organism. The two major forms are structurally similar with subunit sizes of 36 and 41 kDa, respectively. The larger form is produced by mycelia growing in arginine-supplemented medium. Both forms are localized in the cytosol. The structural gene for arginase, aga, has been cloned and sequenced; it contains a 358-codon open reading frame with three in-frame ATGs at the amino terminus. Mutagenesis of these ATGs revealed that the first ATG initiates the 41-kDa protein and the third ATG initiates the 36-kDa protein. Mutation of the second ATG has no effect on translation. Northern analysis demonstrated that a 1.4-kilobase (kb) transcript is synthesized in minimal medium and both a 1.4- and 1.7-kb transcript are produced in arginine-supplemented medium. Primer extension identified the 5' ends of each transcript and demonstrated that the first and third ATG of the open reading frame are the initial AUGs of the 1.7- and 1. 4-kb mRNA, respectively. The results suggest that a basal promoter produces the 1.4-kb transcript and an arginine "activated" promoter is responsible for the 1.7-kb transcript. Tandem promoters are rare in eukaryotic organisms, and they often regulate developmental or tissue-specific gene expression. The possibility that arginase has a role in differentiation in N. crassa is being investigated.
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Affiliation(s)
- S Marathe
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA
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Marathe S, Schissel SL, Yellin MJ, Beatini N, Mintzer R, Williams KJ, Tabas I. Human vascular endothelial cells are a rich and regulatable source of secretory sphingomyelinase. Implications for early atherogenesis and ceramide-mediated cell signaling. J Biol Chem 1998; 273:4081-8. [PMID: 9461601 DOI: 10.1074/jbc.273.7.4081] [Citation(s) in RCA: 199] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We recently reported that macrophages and fibroblasts secrete a Zn2+-dependent sphingomyelinase (S-SMase), which, like lysosomal SMase, is a product of the acid SMase gene. S-SMase may cause subendothelial retention and aggregation of lipoproteins during atherogenesis, and the acid SMase gene has been implicated in ceramide-mediated cell signaling, especially involving apoptosis of endothelial cells. Because of the central importance of the endothelium in each of these processes, we now sought to examine the secretion and regulation of S-SMase by vascular endothelial cells. Herein we show that cultured human coronary artery and umbilical vein endothelial cells secrete massive amounts of S-SMase (up to 20-fold more than macrophages). Moreover, whereas S-SMase secreted by macrophages and fibroblasts is almost totally dependent on the addition of exogenous Zn2+, endothelium-derived S-SMase was partially active even in the absence of added Zn2+. Secretion of S-SMase by endothelial cells occurred both apically and basolaterally, suggesting an endothelial contribution to both serum and arterial wall SMase. When endothelial cells were incubated with inflammatory cytokines, such as interleukin-1beta and interferon-gamma, S-SMase secretion by endothelial cells was increased 2-3-fold above the already high level of basal secretion, whereas lysosomal SMase activity was decreased. The mechanism of interleukin-1beta-stimulated secretion appears to be through increased routing of a SMase precursor protein through the secretory pathway. In summary, endothelial cells are a rich and regulatable source of enzymatically active S-SMase, suggesting physiologic and pathophysiologic roles for this enzyme.
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Affiliation(s)
- S Marathe
- Department of Medicine, Columbia University, New York, New York 10032, USA
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Tabas I, Marathe S, Keesler GA, Beatini N, Shiratori Y. Evidence that the initial up-regulation of phosphatidylcholine biosynthesis in free cholesterol-loaded macrophages is an adaptive response that prevents cholesterol-induced cellular necrosis. Proposed role of an eventual failure of this response in foam cell necrosis in advanced atherosclerosis. J Biol Chem 1996; 271:22773-81. [PMID: 8798453 DOI: 10.1074/jbc.271.37.22773] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Macrophages in atherosclerotic lesions accumulate free cholesterol (FC) as well as cholesteryl ester and appear to have high rates of phospholipid (PL) synthesis and increased PL mass. Previous short term (i.e. </=24 h) studies with cultured macrophages have shown that these cells respond to FC loading by up-regulating phosphatidylcholine biosynthesis. We propose that this response is adaptive by keeping the FC:PL ratio in the macrophages from reaching toxic levels. We further propose that one cause of macrophage necrosis, a prominent and important event in atherosclerosis, is an eventual decrease of this adaptive response. To explore these ideas, cultured macrophages were loaded with FC for up to 4 days and assayed for phosphatidylcholine biosynthesis, FC and PL mass, and cytotoxicity. For the first 24 h, cellular phosphatidylcholine biosynthesis and FC and PL mass increased 3-4-fold, and thus the FC:PL molar ratio was prevented from reaching very high levels; at this point, there were no overt signs of cytotoxicity. Over the next 24-48 h, however, phosphatidylcholine biosynthesis, and then phosphatidylcholine mass, began to decrease. Initially, the macrophages remained healthy and continued to accumulate FC, but eventually these macrophages, but not unloaded macrophages, became necrotic (swollen organelles and disrupted membranes). Lipoprotein dose studies indicated a close relationship between the onset of macrophage necrosis and the FC:PL ratio. To test further the causal nature of these relationships, cellular FC and PL mass were independently manipulated by using high density lipoprotein3 (HDL3) to decrease cellular FC and choline depletion to decrease cellular PC. As predicted by our hypotheses, HDL3 protected FC-loaded macrophages from necrosis, whereas choline depletion accelerated cytotoxic changes. These findings support the idea that the initial increase in phosphatidylcholine biosynthesis in FC-loaded macrophages is an adaptive response that prevents cholesterol-induced macrophage necrosis. We propose that an eventual failure of the PL response in foam cells may represent one cause of macrophage necrosis in advanced atherosclerotic lesions.
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Affiliation(s)
- I Tabas
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA
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Echevskaya LG, Zakharov VA, Marathe S, Sehra JC, Jog JP, Sivaram S. Thermal and X-ray investigations of ethylene–α-olefin copolymers obtained with highly active supported Ti–Mg and V–Mg catalysts. POLYM INT 1994. [DOI: 10.1002/pi.1994.210330113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Marathe S, Connerton IF, Fincham JR. Duplication-induced mutation of a new Neurospora gene required for acetate utilization: properties of the mutant and predicted amino acid sequence of the protein product. Mol Cell Biol 1990; 10:2638-44. [PMID: 2140429 PMCID: PMC360622 DOI: 10.1128/mcb.10.6.2638-2644.1990] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
A cloned Neurospora crassa genomic sequence, selected as preferentially transcribed when acetate was the sole carbon source, was introduced in extra copies at ectopic loci by transformation. Sexual crossing of transformants yielded acetate nonutilizing mutants with methylation and restriction site changes within both the ectopic DNA and the normally located gene. Such changes are typical of the duplication-induced premeiotic disruption (the RIP effect) first described by Selker et al. (E. U. Selker, E. B. Cambareri, B. C. Jensen, and K. R. Haack, Cell 51:741-752, 1987). The mutants had the unusual phenotype of growth on ethanol but not on acetate as the carbon source. In a cross to the wild type of a mutant strain in which the original ectopic gene sequence had been removed by segregation, the acetate nonutilizing phenotype invariably segregated together with a RIP-induced EcoRI site at the normal locus. This mutant was transformed to the ability to use acetate by the cloned sequence. The locus of the mutation, designated acu-8, was mapped between trp-3 and un-15 on linkage group 2. The transcribed portion of the clone, identified by probing with cDNA, was sequenced, and a putative 525-codon open reading frame with two introns was identified. The codon usage was found to be strongly biased in a way typical of most Neurospora genes sequenced so far. The predicted amino acid sequence shows no significant resemblance to anything previously recorded. These results provide a first example of the use of the RIP effect to obtain a mutant phenotype for a gene previously known only as a transcribed wild-type DNA sequence.
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Affiliation(s)
- S Marathe
- Department of Genetics, Cambridge University, United Kingdom
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49
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Marathe S. Studies on the nature of the reactions and species involved in potentiometric titrimetric determination of uranium. Talanta 1983; 30:151-4. [DOI: 10.1016/0039-9140(83)80041-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/1981] [Revised: 09/22/1982] [Accepted: 10/04/1982] [Indexed: 11/29/2022]
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Shafi'ee A, Marathe S, Bhatkar R, Hite G. Absolute configurations of the enantiomeric pheniramines, methylphenidates, and pipradrols. J Pharm Sci 1967; 56:1689-90. [PMID: 4385278 DOI: 10.1002/jps.2600561240] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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