70 results on '"Imran I. Patel"'
Search Results
2. Surface-enhanced Raman spectroscopy of the endothelial cell membrane.
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Simon W Fogarty, Imran I Patel, Francis L Martin, and Nigel J Fullwood
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Medicine ,Science - Abstract
We applied surface-enhanced Raman spectroscopy (SERS) to cationic gold-labeled endothelial cells to derive SERS-enhanced spectra of the bimolecular makeup of the plasma membrane. A two-step protocol with cationic charged gold nanoparticles followed by silver-intensification to generate silver nanoparticles on the cell surface was employed. This protocol of post-labelling silver-intensification facilitates the collection of SERS-enhanced spectra from the cell membrane without contribution from conjugated antibodies or other molecules. This approach generated a 100-fold SERS-enhancement of the spectral signal. The SERS spectra exhibited many vibrational peaks that can be assigned to components of the cell membrane. We were able to carry out spectral mapping using some of the enhanced wavenumbers. Significantly, the spectral maps suggest the distribution of some membrane components are was not evenly distributed over the cells plasma membrane. These results provide some possible evidence for the existence of lipid rafts in the plasma membrane and show that SERS has great potential for the study and characterization of cell surfaces.
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- 2014
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3. Comparing Proton to Photon Radiotherapy Plans: UK Consensus Guidance for Reporting Under Uncertainty for Clinical Trials
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Richard A. Amos, Y. Tsang, Sarah L. Gulliford, O Nicholas, Matthew Lowe, Elizabeth Miles, Catherine Clark, T S A Underwood, Imran I. Patel, Neil G. Burnet, Yen Chang, A. Gosling, and Nicky Sisson
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Organs at Risk ,medicine.medical_specialty ,Consensus ,Proton ,medicine.medical_treatment ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Multidisciplinary approach ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Medical physics ,In patient ,Proton therapy ,Uncertainty analysis ,Clinical Trials as Topic ,Photons ,Modalities ,Manchester Cancer Research Centre ,business.industry ,Radiotherapy Planning, Computer-Assisted ,ResearchInstitutes_Networks_Beacons/mcrc ,Uncertainty ,Nasopharyngeal Neoplasms ,Radiotherapy Dosage ,United Kingdom ,Radiation therapy ,Clinical trial ,Oncology ,030220 oncology & carcinogenesis ,Practice Guidelines as Topic ,Protons ,Tomography, X-Ray Computed ,business - Abstract
In the UK, the recent introduction of high-energy proton beam therapy into national clinical practice provides an opportunity for new clinical trials, particularly those comparing proton and photon treatments. However, comparing these different modalities can present many challenges. Although protons may confer an advantage in terms of reduced normal tissue dose, they can also be more sensitive to uncertainty. Uncertainty analysis is fundamental in ensuring that proton plans are both safe and effective in the event of unavoidable discrepancies, such as variations in patient setup and proton beam range. Methods of evaluating and mitigating the effect of these uncertainties can differ from those approaches established for photon therapy treatments, such as the use of expansion margins to assure safety. These differences should be considered when comparing protons and photons. An overview of the effect of uncertainties on proton plans is presented together with an introduction to some of the concepts and terms that should become familiar to those involved in proton therapy trials. This report aims to provide guidance for those engaged in UK clinical trials comparing protons and photons. This guidance is intended to take a pragmatic approach considering the tools that are available to practising centres and represents a consensus across multidisciplinary groups involved in proton therapy in the UK.
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- 2020
4. Fingerprint-to-CH stretch continuously tunable high spectral resolution stimulated Raman scattering microscope
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Imran I Patel, Carlo Liberale, Luca Genchi, Yeonwoo Lee, Vijayakumar P. Rajamanickam, Andrea Bertoncini, Sergey P. Laptenok, and Tual Monfort
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Chemical imaging ,Microscope ,Materials science ,Nonlinear Optical Microscopy ,General Physics and Astronomy ,Spectrum Analysis, Raman ,01 natural sciences ,Vibration ,General Biochemistry, Genetics and Molecular Biology ,law.invention ,010309 optics ,symbols.namesake ,Optics ,law ,Cell Line, Tumor ,Oscillometry ,0103 physical sciences ,Microscopy ,Humans ,Polymethyl Methacrylate ,General Materials Science ,Spectral resolution ,business.industry ,010401 analytical chemistry ,Resolution (electron density) ,General Engineering ,Hyperspectral imaging ,General Chemistry ,Hep G2 Cells ,Carbon ,0104 chemical sciences ,symbols ,Polystyrenes ,business ,Raman spectroscopy ,Raman scattering ,Hydrogen - Abstract
Stimulated Raman scattering (SRS) microscopy is a label-free method generating images based on chemical contrast within samples, and has already shown its great potential for high-sensitivity and fast imaging of biological specimens. The capability of SRS to collect molecular vibrational signatures in bio-samples, coupled with the availability of powerful statistical analysis methods, allows quantitative chemical imaging of live cells with sub-cellular resolution. This application has substantially driven the development of new SRS microscopy platforms. Indeed, in recent years, there has been a constant effort on devising configurations able to rapidly collect Raman spectra from samples over a wide vibrational spectral range, as needed for quantitative analysis by using chemometric methods. In this paper, an SRS microscope which exploits spectral shaping by a narrowband and rapidly tunable acousto-optical tunable filter (AOTF) is presented. This microscope enables spectral scanning from the Raman fingerprint region to the Carbon-Hydrogen (CH)-stretch region without any modification of the optical setup. Moreover, it features also a high enough spectral resolution to allow resolving Raman peaks in the crowded fingerprint region. Finally, application of the developed SRS microscope to broadband hyperspectral imaging of biological samples over a large spectral range from 800 to 3600 cm-1 , is demonstrated.
- Published
- 2019
5. Automated Monte-Carlo re-calculation of proton therapy plans using <scp>Geant4/Gate</scp>: implementation and comparison to plan-specific quality assurance measurements
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Imran I. Patel, Ranald I Mackay, Peter Sitch, Jenny C Richardson, Carla Winterhalter, and A. Aitkenhead
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medicine.medical_specialty ,Quality Assurance, Health Care ,Computer science ,Monte Carlo method ,Plan (drawing) ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Software ,Proton Therapy ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Patient treatment ,Medical physics ,Pencil-beam scanning ,Radiation treatment planning ,Proton therapy ,Full Paper ,business.industry ,Radiotherapy Planning, Computer-Assisted ,Reproducibility of Results ,Radiotherapy Dosage ,General Medicine ,England ,030220 oncology & carcinogenesis ,Calibration ,business ,Monte Carlo Method ,Quality assurance ,Algorithms - Abstract
Objectives: Software re-calculation of proton pencil beam scanning plans provides a method of verifying treatment planning system (TPS) dose calculations prior to patient treatment. This study describes the implementation of AutoMC, a Geant4 v10.3.3/Gate v8.1 (Gate-RTion v1.0)-based Monte-Carlo (MC) system for automated plan re-calculation, and presents verification results for 153 patients (730 fields) planned within year one of the proton service at The Christie NHS Foundation Trust. Methods: A MC beam model for a Varian ProBeam delivery system with four range-shifter options (none, 2 cm, 3 cm, 5 cm) was derived from beam commissioning data and implemented in AutoMC. MC and TPS (Varian Eclipse v13.7) calculations of 730 fields in solid-water were compared to physical plan-specific quality assurance (PSQA) measurements acquired using a PTW Octavius 1500XDR array and PTW 31021 Semiflex 3D ion chamber. Results: TPS and MC showed good agreement with array measurements, evaluated using γ analyses at 3%, 3 mm with a 10% lower dose threshold:>94% of fields calculated by the TPS and >99% of fields calculated by MC had γ ≤ 1 for>95% of measurement points within the plane. TPS and MC also showed good agreement with chamber measurements of absolute dose, with systematic differences of Conclusions: Reliable independent verification of the TPS dose calculation is a valuable complement to physical PSQA and may facilitate reduction of the physical PSQA workload alongside a thorough delivery system quality assurance programme. Advances in knowledge: A Gate/Geant4-based MC system is thoroughly validated against an extensive physical PSQA dataset for 730 clinical fields, showing that clinical implementation of MC for PSQA is feasible.
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- 2020
6. Quantum cascade laser infrared spectroscopy of single cancer cells
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Siarhei Laptenok, Andrea Bertoncini, Luca Tirinato, Imran I Patel, Vijayakumar P. Rajamanickam, Francesca Pagliari, and Carlo Liberale
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0301 basic medicine ,Materials science ,business.industry ,010401 analytical chemistry ,Analytical chemistry ,Infrared spectroscopy ,01 natural sciences ,0104 chemical sciences ,law.invention ,03 medical and health sciences ,030104 developmental biology ,law ,Cancer cell ,Optoelectronics ,business ,Quantum cascade laser - Published
- 2017
7. Infrared spectroscopy with multivariate analysis segregates low-grade cervical cytology based on likelihood to regress, remain static or progress
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Ann McHugh, Júlio Trevisan, Marwan Ma'ayeh, Nikhil Purandare, Kássio M. G. Lima, Francis Martin, Günther von Bünau, Walter Prendiville, Imran I. Patel, and Pierre L. Martin Hirsch
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Cervical cancer ,medicine.medical_specialty ,Multivariate analysis ,Cervical screening ,business.industry ,General Chemical Engineering ,General Engineering ,medicine.disease ,Linear discriminant analysis ,Analytical Chemistry ,Cytology ,Principal component analysis ,medicine ,Atypia ,Radiology ,business ,Progressive disease - Abstract
Cervical cancer is the 2nd most common female cancer worldwide. However, in the developed world, cervical screening has reduced this cancer burden. Most smear referrals are low-grade, requiring continuous monitoring until they regress. Others need monitoring for static disease, while a few require treatment due to persistent low-grade or progressive disease. The ‘Holy Grail’ in cervical screening is predicting which patient is likely to have progressive disease. Fourier-transform infrared (FTIR) spectroscopy exploits the fact that an infrared (IR) spectrum represents a “biochemical-cell fingerprint”, which can be obtained from a cellular specimen based on a wavenumber-dependent absorption band pattern of constituents' vibrating chemical bonds. Low-grade (CIN1) specimens (n = 67) diagnosed on cytology were analysed using IR spectroscopy. The n = 67 study participants were rescreened by conventional cytology after a year whereupon three showed progressive disease and 31 had persistent low-grade atypia; 33 had regressed. Spectra from the initial cytology samples were then analysed using principal component analysis (PCA) with output (10 principal components) being inputted into linear discriminant analysis (LDA) to predict which samples would progress, remain static or regress; this approach was compared with variable selection techniques, namely the successive projection algorithm (SPA) and genetic algorithm (GA). Significant wavenumbers distinguishing regressive vs. static disease were 1736 cm−1, 1680 cm−1, 1512 cm−1, 1234 cm−1, 1099 cm−1 and 968 cm−1; separating the two categories is difficult due to a significant degree of ‘overlap’. Progressive disease can be significantly differentiated from static disease based on wavenumbers 1662 cm−1, 1648 cm−1, 1628 cm−1, 1512 cm−1, 1474 cm−1 and 965 cm−1; it can be segregated from regressive disease with 1686 cm−1, 1674 cm−1, 1625 cm−1, 1561 cm−1, 1525 cm−1 and 1310 cm−1. The GA–LDA model shows good separation for all categories (i.e., regressive vs. static vs. progressive disease) using 35 wavenumbers. An ability to predict progressive disease will reduce the need for repeat smears every six months whilst allowing early identification of patients who require treatment.
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- 2014
8. CARS based label-free assay for assessment of drugs by monitoring lipid droplets in tumour cells
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Alexander Schreiner, Imran I. Patel, Sumeet Mahajan, Kevin M. Brindle, Stefanie Reichelt, Christian Steuwe, Mahmud Ul-Hasan, and Joan Boren
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Chemistry ,Cell growth ,Stereochemistry ,Cell ,General Engineering ,General Physics and Astronomy ,General Chemistry ,General Biochemistry, Genetics and Molecular Biology ,Cell biology ,medicine.anatomical_structure ,In vivo ,Cytoplasm ,Lipid droplet ,medicine ,Staurosporine ,General Materials Science ,Camptothecin ,Ex vivo ,medicine.drug - Abstract
Coherent anti-Stokes Raman scattering (CARS) is becoming an established tool for label-free multi-photon imaging based on molecule specific vibrations in the sample. The technique has proven to be particularly useful for imaging lipids, which are abundant in cells and tissues, including cytoplasmic lipid droplets (LD), which are recognized as dynamic organelles involved in many cellular functions. The increase in the number of lipid droplets in cells undergoing cell proliferation is a common feature in many neoplastic processes [1] and an increase in LD number also appears to be an early marker of drug-induced cell stress and subsequent apoptosis [3]. In this paper, a CARS-based label-free method is presented to monitor the increase in LD content in HCT116 colon tumour cells treated with the chemotherapeutic drugs Etoposide, Camptothecin and the protein kinase inhibitor Staurosporine. Using CARS, LDs can easily be distinguished from other cell components without the application of fluorescent dyes and provides a label-free non-invasive drug screening assay that could be used not only with cells and tissues ex vivo but potentially also in vivo.
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- 2013
9. Infrared microspectroscopy identifies biomolecular changes associated with chronic oxidative stress in mammary epithelium and stroma of breast tissues from healthy young women
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Judith Weisz, Imran I. Patel, Debra A. Shearer, Simon W. Fogarty, Nigel J. Fullwood, Luca Quaroni, and Francis Martin
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Adult ,Cancer Research ,Pathology ,medicine.medical_specialty ,Stromal cell ,Breast Neoplasms ,In Vitro Techniques ,Biology ,medicine.disease_cause ,Young Adult ,Basal (phylogenetics) ,Breast cancer ,Stroma ,Reference Values ,Spectroscopy, Fourier Transform Infrared ,medicine ,Humans ,Breast ,Pharmacology ,Aldehydes ,Epithelial Cells ,medicine.disease ,Pathophysiology ,Oxidative Stress ,Cell Transformation, Neoplastic ,Oncology ,Mammary Epithelium ,Molecular Medicine ,Female ,Stromal Cells ,Carcinogenesis ,Biomarkers ,Oxidative stress ,Research Paper - Abstract
Studies of the decades-long latent stages of breast carcinogenesis have been limited to when hyperplastic lesions are already present. Investigations of earlier stages of breast cancer (BC) latency have been stymied by the lack of fiducial biomarkers needed to identify where in histologically normal tissues progression toward a BC might be taking place. Recent evidence suggests that a marker of chronic oxidative stress (OxS), protein adducts of 4-hydroxy-2-nonenal (4HNE), can meet this need. Specifically: (1) 4HNE immunopositive (4HNE+) mammary epithelial (ME) cells were found to be prevalent in normal (reduction mammoplasty) tissues of most women (including many teenagers) studied, representative of those living in the United States’ high risk-posing environment and: (2) marked (>1.5-fold) differences were identified between tissues of healthy young women with many vs. few 4HNE+ ME cells in the relative levels of transcripts for 42 of the 84 OxS-associated genes represented in SABioscience Oxidative-Stress/Oxidative-Defense PCR array. Herein we used synchrotron radiation-based Fourier-transform infrared (SR-FTIR) microspectroscopy to identify molecular changes associated with 4HNE adducts in basal and luminal ME cells in terminal ductal units (TDLU), which are the cells of origin of BC, and associated intralobular and interlobular stroma, known contributors to carcinogenesis. Multivariate analysis-derived wavenumbers differentiated 4HNE+ and 4HNE− cells in each of the anatomical compartments. Specifically, principal component and linear discriminant analyses of mid-infrared spectra obtained from these cells revealed unambiguous, statistically highly significant differences in the “biochemical fingerprint” of 4HNE+ vs. 4HNE− luminal and basal ME cells, as well as between associated intralobular and interlobular stroma. These findings demonstrate further SR-FTIR microspectroscopy’s ability to identify molecular changes associated with altered physiological and/or pathophysiological states, in this case with a state of chronic OxS that provides a pro-carcinogenic microenvironment.
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- 2013
10. Exploiting biospectroscopy as a novel screening tool for cervical cancer: towards a framework to validate its accuracy in a routine clinical setting
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Maria Kyrgiou, Georgios Theophilou, Júlio Trevisan, Evangelos Paraskevaidis, Pierre L. Martin-Hirsch, Walter Prendiville, Nikhil Purandare, Mary Martin, Günther von Bünau, Alana L. Mitchell, Ketan Gajjar, Imran I. Patel, George Valasoulis, and Francis Martin
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Cervical cancer ,medicine.medical_specialty ,Cervical screening ,Computer science ,Clinical Biochemistry ,Uterine Cervical Neoplasms ,Clinical settings ,General Medicine ,medicine.disease ,Analytical Chemistry ,Medical Laboratory Technology ,medicine ,Humans ,Mass Screening ,Female ,Medical physics ,Screening tool ,Computational analysis ,General Pharmacology, Toxicology and Pharmaceutics ,Early Detection of Cancer - Abstract
Biospectroscopy is an emerging field that harnesses the platform of physical sciences with computational analysis in order to shed novel insights on biological questions. An area where this approach seems to have potential is in screening or diagnostic clinical settings, where there is an urgent need for new approaches to objectively interrogate large numbers of samples in an objective fashion with acceptable levels of sensitivity and specificity. This review outlines the benefits of biospectroscopy in screening for precancer lesions of the cervix due to its ability to separate different grades of dysplasia. It evaluates the feasibility of introducing this technique into cervical screening programs on the basis of its ability to identify biomarkers of progression within derived spectra (‘biochemical‑cell fingerprints’).
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- 2013
11. OS3.6 Optical Biopsies in Neurosurgery: Raman Spectroscopy for the Real-time Identification of Tumours during Surgery
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U. Faiz, Haishan Zeng, Babar Vaqas, Kevin O’Neill, M. Short, and Imran I. Patel
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Cancer Research ,medicine.medical_specialty ,business.industry ,010401 analytical chemistry ,01 natural sciences ,OS3 Models ,0104 chemical sciences ,Surgery ,010309 optics ,symbols.namesake ,Oncology ,0103 physical sciences ,medicine ,symbols ,Identification (biology) ,Neurology (clinical) ,Neurosurgery ,business ,Raman spectroscopy - Published
- 2016
12. Spatial and temporal age-related spectral alterations in benign human breast tissue
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Rebecca J. Strong, Helen F. Stringfellow, Francis Martin, Simon W. Fogarty, Júlio Trevisan, Georgios Theophilou, Kelly A. Heys, Imran I. Patel, and Pierre L. Martin-Hirsch
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0301 basic medicine ,Pathology ,medicine.medical_specialty ,Chemistry ,Organic Chemistry ,Myoepithelial cell ,Disease ,medicine.disease ,Epithelium ,Analytical Chemistry ,Biomarker (cell) ,Inorganic Chemistry ,Menopause ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,medicine.anatomical_structure ,Breast cancer ,030220 oncology & carcinogenesis ,medicine ,Stem cell ,Thelarche ,skin and connective tissue diseases ,Spectroscopy - Abstract
Epidemiological evidence suggests that cancers attributable to exogenous carcinogenic agents may appear decades after initiating exposures. Environmental factors including lifestyle and/or diet have been implicated in the aetiology of breast cancer. Breast tissue undergoes continuous molecular and morphological changes from the time of thelarche to menopause and thereafter. These alterations are both cyclical and longitudinal, and can be influenced by several environmental factors including exposure to oestrogens. Research into the latent period leading to breast carcinogenesis has been mostly limited to when hyperplastic lesions are present. Investigations to identify a biomarker of commitment to disease in normal breast tissue are hindered by the molecular and histological diversity of disease-free breast tissue. Benign tissue from reduction mammoplasties provides an opportunity to study biochemical differences between women of similar ages as well as alterations with advancing age. Herein, synchrotron radiation-based Fourier-transform infrared (SR-FTIR) microspectroscopy was used to examine the terminal ductal lobular epithelium (TDLU) and, intra- and inter-lobular epithelium to identify spatial and temporal changes within these areas. Principal component analysis (PCA) followed by linear discriminant analysis of mid-infrared spectra revealed unambiguous inter-individual as well as age-related differences in each histological compartment interrogated. Moreover, exploratory PCA of luminal and myoepithelial cells within the TDLU indicated the presence of specific cells, potentially stem cells. Understanding alterations within benign tissue may assist in the identification of alterations in latent pre-clinical stages of breast cancer.
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- 2016
13. Chemical Composition and Sulfur Speciation in Bulk Tissue by X-Ray Spectroscopy and X-Ray Microscopy: Corneal Development during Embryogenesis
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Andrew J. Quantock, Carlo Knupp, Francis Martin, Imran I. Patel, Elena Koudouna, Giulia Veronesi, and Marine Cotte
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Analytical chemistry ,Biophysics ,Embryonic Development ,chemistry.chemical_element ,Chick Embryo ,Cornea ,Microscopy ,Fluorescence microscope ,Animals ,Spectroscopy ,Chemical composition ,Principal Component Analysis ,Systems Biophysics ,X-ray absorption spectroscopy ,X-ray spectroscopy ,X-Rays ,Discriminant Analysis ,Sulfur ,X-Ray Absorption Spectroscopy ,chemistry ,Thermodynamics ,Absorption (chemistry) ,Chickens - Abstract
The chemical composition and sulfur (S) speciation of developing chick corneas at embryonic days 12, 14, and 16 were investigated using synchrotron scanning x-ray fluorescence microscopy and x-ray absorption near-edge structure spectroscopy. The aim was to develop techniques for the analysis of bulk tissue and identify critical physicochemical variations that correlate with changes in corneal structure-function relationships. Derived data were subjected to principal component analysis and linear discriminant analysis, which highlighted differences in the elemental and S species composition at different stages of embryonic growth. Notably, distinct elemental compositions of chlorine, potassium, calcium, phosphorus, and S altered with development during the transition of the immature opaque cornea to a mature transparent tissue. S structure spectroscopy revealed developmentally regulated alterations in thiols, organic monosulfides, ester sulfate, and inorganic sulfate species. The transient molecular structures and compositional changes reported here provide a deeper understanding of the underlying basis of corneal development during the acquisition of transparency. The experimental and analytical approach is new, to our knowledge, and has wide potential applicability in the life sciences.
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- 2012
- Full Text
- View/download PDF
14. Concentration-dependent effects of carbon nanoparticles in gram-negative bacteria determined by infrared spectroscopy with multivariate analysis
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Matthew J. Riding, Imran I. Patel, Francis Martin, Kirk T. Semple, Valon Llabjani, Kevin C. Jones, and Júlio Trevisan
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Fullerene ,Dose-Response Relationship, Drug ,Nanotubes, Carbon ,Chemistry ,Health, Toxicology and Mutagenesis ,Nanoparticle Type ,Infrared spectroscopy ,Nanoparticle ,General Medicine ,Toxicology ,medicine.disease_cause ,Photochemistry ,Pollution ,Soot ,Nanotoxicology ,Attenuated total reflection ,Gram-Negative Bacteria ,Multivariate Analysis ,Spectroscopy, Fourier Transform Infrared ,Toxicity Tests ,medicine ,Organic chemistry ,Fullerenes ,Spectroscopy ,Environmental Monitoring - Abstract
With increasing production of carbon nanoparticles (CNPs), environmental release of these entities becomes an ever-greater inevitability. However, many questions remain regarding their impact on soil microorganisms. This study examined the effects of long or short multiwalled carbon nanotubes (MWCNTs), C60 fullerene and fullerene soot in Gram-negative bacteria. Attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy was applied to derive signature spectral fingerprints of effects. A concentration-dependent response in spectral alterations was observed for each nanoparticle type. Long or short MWCNTs and fullerene soot gave rise to similar alterations to lipids, Amide II and DNA. The extent of alteration varies with nanoparticle size, with smaller short MWCNTs resulting in greater toxicity than long MWCNTs. Fullerene soot was the least toxic. C60 results in the most distinct and largest overall alterations, notably in extensive protein alteration. This work demonstrates a novel approach for assaying and discriminating the effects of CNPs in target systems.
- Published
- 2012
15. Differential Effects in Mammalian Cells Induced by Chemical Mixtures in Environmental Biota As Profiled Using Infrared Spectroscopy
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Weiyi Pang, Júlio Trevisan, Abdullah A. Ahmadzai, Imran I. Patel, John D. Crosse, Kevin C. Jones, Valon Llabjani, Francis Martin, and Richard F. Shore
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Infrared Rays ,Infrared spectroscopy ,Cell Line ,Birds ,chemistry.chemical_compound ,food ,Spectroscopy, Fourier Transform Infrared ,Halogenated Diphenyl Ethers ,Animals ,Environmental Chemistry ,Spectroscopy ,Ovum ,Mammals ,Spectroscopy, Near-Infrared ,food.dish ,Diphenyl ether ,Polychlorinated biphenyl ,Biota ,General Chemistry ,Contamination ,Polychlorinated Biphenyls ,chemistry ,Environmental chemistry ,Attenuated total reflection ,Biological Assay ,Environmental Pollutants ,Environmental Monitoring ,Northern gannet - Abstract
Environmental contaminants accumulate in many organisms and induce a number of adverse effects. As contaminants mostly occur in the environment as mixtures, it remains to be fully understood which chemical interactions induce the most important toxic responses. In this study, we set out to determine the effects of chemical contaminants extracted from Northern Gannet (Morus bassanus) eggs (collected from the UK coast from three sampling years (1987, 1990, and 1992) on cell cultures using infrared (IR) spectroscopy with computational data handling approaches. Gannet extracts were chemically analyzed for different contaminants, and MCF-7 cell lines were treated for 24 h in a dose-related manner with individual-year extracts varying in their polybrominated diphenyl ether (PBDE) to polychlorinated biphenyl (PCB) ratios. Treated cellular material was then fixed and interrogated using attenuated total reflection Fourier-transform IR (ATR-FTIR) spectroscopy; resultant IR spectra were computationally analyzed to derive dose-response relationships and to identify biomarkers associated with each contaminant mixture treatment. The results show distinct biomarkers of effect are related to each contamination scenario, with an inverse relationship with dose observed. This study suggests that specific contaminant mixtures induce cellular alterations in the DNA/RNA spectral region that are most pronounced at low doses. It also suggests alterations in the "biochemical-cell fingerprint" of IR spectra can be indicative of mixture exposures.
- Published
- 2011
16. Combining Immunolabeling and Surface-Enhanced Raman Spectroscopy on Cell Membranes
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Simon W. Fogarty, Nigel J. Fullwood, Imran I. Patel, Francis Martin, Matthew D. Hodges, Jemma G. Kelly, and Adam J. Bentley
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Materials science ,Cell Membrane ,Cell ,Epithelium, Corneal ,General Engineering ,Membrane Proteins ,General Physics and Astronomy ,Nanotechnology ,Surface-enhanced Raman spectroscopy ,Spectrum Analysis, Raman ,Immunohistochemistry ,Silver nanoparticle ,Cell membrane ,symbols.namesake ,Immunolabeling ,Membrane ,medicine.anatomical_structure ,Microscopy ,symbols ,medicine ,Humans ,General Materials Science ,Raman spectroscopy ,Cells, Cultured ,Epitope Mapping - Abstract
We applied surface-enhanced Raman spectroscopy (SERS) to immunolabeled endothelial cells to derive enhanced spectra of the biomolecular makeup of the cellular surface. A two-step immunolabeling protocol with gold-conjugated antibodies coupled with silver enhancement to attach silver nanoparticles to the cell surface was employed. This approach generated ∼50-fold SERS enhancement of spectral signals. The SERS spectra exhibited several SERS-enhanced peaks associated with cell membrane components. The SERS detection of silver nanoparticles proved more far more sensitive than conventional light microscopy techniques. The SERS enhancement allowed us to carry out spectral mapping using wavenumbers associated with membrane components that correlated directly with the distribution of silver nanoparticles. SERS has the potential to detect immunolabeling at lower levels than is possible using conventional immunolabeling methods while simultaneously providing unique, spatially defined, biochemical information.
- Published
- 2011
17. Infrared spectroscopy with multivariate analysis to interrogate endometrial tissue: a novel and objective diagnostic approach
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Helen F. Stringfellow, Júlio Trevisan, Francis Martin, Pierre L. Martin-Hirsch, Siân E. Taylor, Katherine M. Ashton, Nicholas J Wood, Patrick J. Keating, Imran I. Patel, and Karen T. Cheung
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Cancer Research ,Pathology ,medicine.medical_specialty ,Multivariate analysis ,medicine.medical_treatment ,Infrared spectroscopy ,Haematoxylin ,Endometrium ,chemistry.chemical_compound ,Spectroscopy, Fourier Transform Infrared ,medicine ,Humans ,infrared spectroscopy ,Molecular Diagnostics ,Fixative ,Hysterectomy ,business.industry ,Endometrial cancer ,Cancer ,medicine.disease ,Endometrial Neoplasms ,multivariate analysis ,medicine.anatomical_structure ,Oncology ,chemistry ,endometrial cancer ,Female ,business ,attenuated total reflection Fourier-transform infrared spectroscopy - Abstract
Background: Endometrial cancer is the most common gynaecological malignancy in the United Kingdom. Diagnosis currently involves subjective expert interpretation of highly processed tissue, primarily using microscopy. Previous work has shown that infrared (IR) spectroscopy can be used to distinguish between benign and malignant cells in a variety of tissue types. Methods: Tissue was obtained from 76 patients undergoing hysterectomy, 36 had endometrial cancer. Slivers of endometrial tissue (tumour and tumour-adjacent tissue if present) were dissected and placed in fixative solution. Before analysis, tissues were thinly sliced, washed, mounted on low-E slides and desiccated; 10 IR spectra were obtained per slice by attenuated total reflection Fourier-transform IR (ATR-FTIR) spectroscopy. Derived data was subjected to principal component analysis followed by linear discriminant analysis. Post-spectroscopy analyses, tissue sections were haematoxylin and eosin-stained to provide histological verification. Results: Using this approach, it is possible to distinguish benign from malignant endometrial tissue, and various subtypes of both. Cluster vector plots of benign (verified post-spectroscopy to be free of identifiable pathology) vs malignant tissue indicate the importance of the lipid and secondary protein structure (Amide I and Amide II) regions of the spectrum. Conclusion: These findings point towards the possibility of a simple objective test for endometrial cancer using ATR-FTIR spectroscopy. This would facilitate earlier diagnosis and so reduce the morbidity and mortality associated with this disease.
- Published
- 2011
18. Expression of ERα, its ERαΔ3 Splice Variant and γ-SYNUCLEIN in Ovarian Cancer: A Pilot Study
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Karen T. Cheung, Helen F. Stringfellow, Adam J. Bentley, Francis Martin, Nigel J. Fullwood, Imran I. Patel, Siân E. Taylor, and Pierre L. Martin-Hirsch
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Pathology ,medicine.medical_specialty ,Environmental Engineering ,medicine.diagnostic_test ,business.industry ,Angiogenesis ,Alternative splicing ,medicine.disease ,Immunofluorescence ,Article ,Industrial and Manufacturing Engineering ,Metastasis ,Pathogenesis ,Neovascularization ,Gene expression ,medicine ,medicine.symptom ,Ovarian cancer ,business - Abstract
AIMS: Ovarian cancer has the highest mortality of any gynaecological malignancy; this is due to rapid peritoneal spread of tumour cells and neovascularization. Understanding the mechanisms underlying this is critical to developing early diagnostic or treatment strategies. We devised a pilot study to examine the role of γ-SYNUCLEIN (γ-SYN), oestrogen receptor (ER)α, and the splice variant ERαΔ3. METHODOLOGY: With ethical approval, ovarian tissue was collected from patients (n=24) undergoing oopherectomy for non-ovarian pathology or primary surgery for suspected ovarian cancer. Quantitative gene expression analysis was employed for γ-SYN, ERα, and ERαΔ3. To identify the in situ localization, immunofluorescence for γ-syn was carried out. RESULTS: Ovarian tumour tissue exhibited an elevated expression of γ-SYN and high-grade tumours had an elevated ERαΔ3:ERα ratio compared with benign tissue. The majority of previous studies point to the γ-syn protein being present in epithelial cells of high-grade disease. Our study supports this, but additionally we conclusively identify its presence in the endothelial cells of vasculature surrounding low-grade disease; immunofluorescence was strongest in the apical cells surrounding the lumen. CONCLUSION: Our results demonstrate for the first time that there are readily-expressed levels of γ-SYN and ERαΔ3 in normal ovarian tissue and ovarian tumours. In high-grade disease, γ-syn and an elevated ERαΔ3:ERα ratio might confer metastatic potential to the tumourigenic cells and promote neoangiogenesis. Future in vitro studies might be necessary to delineate such a mechanism, which could potentially be the basis of early intervention.
- Published
- 2011
19. Constitutive expression of bioactivating enzymes in normal human prostate suggests a capability to activate pro-carcinogens to DNA-damaging metabolites
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David H. Phillips, Narasimhan Ragavan, Volker M. Arlt, Francis Martin, Paras B. Singh, Walter Meinl, Caroline M. Nicholson, Hansruedi Glatt, Eva Frei, Osman Sozeri, and Imran I. Patel
- Subjects
chemistry.chemical_classification ,Regulation of gene expression ,Sulfotransferase ,biology ,DNA damage ,Urology ,Cytochrome P450 ,medicine.disease_cause ,Molecular biology ,Reverse transcriptase ,Blot ,Enzyme ,Oncology ,chemistry ,Biochemistry ,medicine ,biology.protein ,Carcinogenesis - Abstract
BACKGROUND. The constitutive bioactivating capacity of human prostate may play a role in determining risk of adenocarcinoma developing in this tissue. Expression of candidate enzymes that convert exogenous and/or endogenous agents into reactive DNA-damaging species would suggest the potential to generate initiating events in prostate cancer (CaP). METHODS. Normal prostate tissues from UK-resident Caucasians (n = 10) were collected following either radical retropubic prostatectomy (RRP) or cystaprostatectomy (CyP). An analysis of gene and protein expression of candidate metabolizing enzymes, including cytochrome P450 (CYP) 1A1, CYP1A2, CYP1B1, N-acetyltransferase 1 (NAT1), sulfotransferase (SULT) 1A1, SULT1A3, NAD(P) H: quinone oxidoreductase (NQO1), prostaglandin H synthase 1 (cyclooxygenase 1; COX1), and CYP oxidoreductase (POR) was carried out. Quantitative real-time reverse transcriptase polymerase chain reaction, Western blot, and immunohistochemical analysis were conducted. RESULTS. Except for CYP1A1 and CYP1A2, the metabolizing enzymes examined appeared to be expressed with minimal inter-individual variation (in general, approximately two-to fivefold) in the expression levels. Enzymes such as CYP1B1 and NQO1 that are capable of bioactivating pro-carcinogens to reactive metabolites were readily identifiable in human prostate. Immunohistochemical analysis showed that although some expression is located in the stroma, the majority is localized to epithelial cells lining the glandular elements of the tissue; these are the cells from which CaP might arise. CONCLUSION. Constitutive expression of bioactivating enzymes confers the potential to convert a range of exogenous and/or endogenous agents to reactive species capable of inducing DNA damaging events. These findings suggest an organ capability for pro-carcinogen activation that could play an important role in the etiology of human CaP. Prostate 70: 15861599, 2010. (C) 2010 Wiley-Liss, Inc.
- Published
- 2010
20. Raman spectroscopy: a novel tool for intraoperative guidance in surgical neuro-oncology
- Author
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Babar Vaqas, Imran I. Patel, Haishan Zeng, Kevin O’Neill, and Michael Short
- Subjects
Cancer Research ,medicine.medical_specialty ,Intra operative ,medicine.medical_treatment ,Neuro oncology ,02 engineering and technology ,Brain tissue ,01 natural sciences ,Abstracts ,symbols.namesake ,Glioma ,medicine ,Craniotomy ,Intraoperative guidance ,business.industry ,010401 analytical chemistry ,021001 nanoscience & nanotechnology ,medicine.disease ,0104 chemical sciences ,Oncology ,symbols ,Neurology (clinical) ,Radiology ,0210 nano-technology ,Raman spectroscopy ,business - Published
- 2018
21. Design and implementation of an electronic data recording and processing system for physics quality control checks in external beam radiotherapy
- Author
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Imran I. Patel and Mike Kirby
- Subjects
Quality Control ,Electronic Data Processing ,Data processing ,Radiotherapy ,business.industry ,Radiotherapy Dosage ,General Medicine ,Resource (project management) ,Microcomputers ,Backup ,Computers, Handheld ,Data logger ,Component (UML) ,Radiation Oncology ,Data analysis ,Humans ,Radiology, Nuclear Medicine and imaging ,Electronic data ,Macro ,business ,Computer hardware - Abstract
Quality control (QC) of external beam radiotherapy equipment ensures that commissioning performance is maintained. Paper based data recording is still used for QC, but this is resource intensive in terms of data calculation and processing. Electronic systems of data recording have many advantages; for example, they facilitate the analysis of data on a regular basis, allowing the user to examine the "health" of each machine; they help review and audit local frequencies of each check and can possibly predict component failure. They also allow for secure calculation of results and automatic charting for routine trend analysis. Initially, data recording at our centre was paper-based for daily, weekly and monthly checks. This paper system has been successfully replaced with an electronic system for QC data recording and processing for linear accelerators and superficial units. The system makes use of personal digital assistants and networked laptops for online recording of data, and networked desktop PCs for offline work. The systems of data recording have been designed using the power of macros within Microsoft Excel, which automatically calculate each QC parameter and charts the data recorded for long-term analysis of trends. As of the beginning of 2006, these systems have been fully implemented. The benefits of implementing such a system are numerous, for example, central storage, backup and archiving of data, for greater security and reducing operator errors in calculations. Other benefits are discussed within the paper. In the future, we hope to develop similar systems of data recording for QC checks on other radiotherapy equipment.
- Published
- 2007
22. Dosimetric characteristics of the Elekta Beam Modulator™
- Author
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A G Glendinning, Mike Kirby, and Imran I. Patel
- Subjects
Film Dosimetry ,Materials science ,Radiological and Ultrasound Technology ,business.industry ,Radiotherapy Planning, Computer-Assisted ,X-Rays ,Penumbra ,Reproducibility of Results ,Radiotherapy Dosage ,Collimator ,Gantry angle ,law.invention ,Radiotherapy, High-Energy ,Leaf width ,Optics ,law ,Humans ,Scattering, Radiation ,Linear Energy Transfer ,Radiology, Nuclear Medicine and imaging ,Particle Accelerators ,Radiotherapy, Conformal ,Radiometry ,business ,Leakage (electronics) - Abstract
The dosimetric characteristics of a production pilot multi-leaf collimator (Elekta Beam Modulator, Elekta Oncology Systems, Crawley, UK) having a 4 mm leaf width (at isocentre) have been investigated. Characteristics explored included leaf bank set-up, penumbra width (80-20%) as a function of leaf position, leaf positioning reproducibility, interleaf leakage and leaf transmission. The penumbra values for leaf ends were measured to be between 4.2 and 4.8 mm for various large rectangular fields studied using Kodak X-omat V film at isocentre (1.5 cm deep). Similar films were taken with a standard 1 cm width multi-leaf collimator (MLC) and the penumbra for leaf ends was found to range from 4.3 to 5.2 mm. Other results showed that the rounded leaf tip provided tight control of the penumbra across the leaves' full range of travel. The positioning of the leaves was within a 0.5 mm range when approaching from the same direction. The maximum interleaf leakage was found to be 1.7% and the average leaf transmission less than 1.0%. No major differences were observed in leakage and transmission with changing gantry angle.
- Published
- 2005
23. Local tumor control after 106Ru brachytherapy of choroidal melanoma
- Author
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Helen Mayles, Bertil Damato, R. Douglas Errington, Imran I. Patel, and Ian R. Campbell
- Subjects
Adult ,Male ,Cancer Research ,medicine.medical_specialty ,medicine.medical_treatment ,Brachytherapy ,Optic disk ,Basal (phylogenetics) ,Clinical Protocols ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Prospective Studies ,Treatment Failure ,Prospective cohort study ,Melanoma ,Aged ,Proportional Hazards Models ,Aged, 80 and over ,Analysis of Variance ,Univariate analysis ,Radiation ,business.industry ,Plaque radiotherapy ,Choroid Neoplasms ,Incidence ,Middle Aged ,Confidence interval ,Surgery ,Radiation therapy ,Oncology ,Female ,Radiology ,Neoplasm Recurrence, Local ,Ruthenium Radioisotopes ,business - Abstract
Purpose To report on local tumor control after 106 Ru brachytherapy for choroidal melanoma. Methods and Materials A total of 458 patients with choroidal melanoma were treated at a single institution between January 1993 and December 2001. The tumors had a median longest basal dimension of 10.6 mm and a median height of 3.2 mm. The brachytherapy was administered using a 15- or 20-mm plaque. For posterior tumors, the plaque was positioned eccentrically with its posterior edge aligned with the posterior tumor margin to reduce the radiation dose to the optic disk and fovea. A minimal scleral dose sufficient to cause visible choroidal atrophy provided a permanent ophthalmoscopic record of the distribution of choroidal irradiation. If radiotherapy to the posterior tumor was uncertain, adjunctive transpupillary thermotherapy was administered 6 months postoperatively. Results The actuarial rates of tumor recurrence were 1%, 2%, and 3% at 2, 5, and 7 years, respectively. Local tumor recurrence correlated with the longest basal tumor dimension (Cox univariate analysis, p = 0.02, risk ratio 1.41, 95% confidence interval 1.06–1.88). Seven of the nine eyes with recurrent tumor were salvaged with additional conservative therapy. Conclusion The low rate of local tumor recurrence suggests that ruthenium plaque radiotherapy is effective with good case selection and if special measures are taken to ensure that the plaque is positioned correctly.
- Published
- 2005
24. SURG-18. REAL-TIME INTRAOPERATIVE MOLECULAR DIAGNOSIS AND SURGICAL GUIDANCE USING LASER SPECTROSCOPY
- Author
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Imran I. Patel, Haishan Zeng, Babar Vaqas, Kevin O’Neill, Michael Short, and Umer Faiz
- Subjects
Cancer Research ,Materials science ,business.industry ,010401 analytical chemistry ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Oncology ,Neurology (clinical) ,0210 nano-technology ,Nuclear medicine ,business ,Spectroscopy - Published
- 2016
25. Surface-enhanced Raman spectroscopy of the endothelial cell membrane
- Author
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Simon W. Fogarty, Nigel J. Fullwood, Imran I. Patel, and Francis Martin
- Subjects
Biophysics ,lcsh:Medicine ,Nanoparticle ,Bioinformatics ,Glycocalyx ,Spectrum Analysis, Raman ,Silver nanoparticle ,Cell membrane ,symbols.namesake ,medicine ,Animals ,Humans ,lcsh:Science ,Lipid raft ,B290 ,Multidisciplinary ,Chemistry ,lcsh:R ,Cell Membrane ,Biology and Life Sciences ,Endothelial Cells ,Cell Biology ,Surface-enhanced Raman spectroscopy ,Membrane ,medicine.anatomical_structure ,Colloidal gold ,Bionanotechnology ,Multivariate Analysis ,symbols ,Microscopy, Electron, Scanning ,lcsh:Q ,Cellular Structures and Organelles ,Raman spectroscopy ,Research Article - Abstract
We applied surface-enhanced Raman spectroscopy (SERS) to cationic gold-labeled endothelial cells to derive SERS-enhanced spectra of the bimolecular makeup of the plasma membrane. A two-step protocol with cationic charged gold nanoparticles followed by silver-intensification to generate silver nanoparticles on the cell surface was employed. This protocol of post-labelling silver-intensification facilitates the collection of SERS-enhanced spectra from the cell membrane without contribution from conjugated antibodies or other molecules. This approach generated a 100-fold SERS-enhancement of the spectral signal. The SERS spectra exhibited many vibrational peaks that can be assigned to components of the cell membrane. We were able to carry out spectral mapping using some of the enhanced wavenumbers. Significantly, the spectral maps suggest the distribution of some membrane components are was not evenly distributed over the cells plasma membrane. These results provide some possible evidence for the existence of lipid rafts in the plasma membrane and show that SERS has great potential for the study and characterization of cell surfaces.
- Published
- 2014
26. Surface Presentation of Functional Peptides in Solution Determines Cell Internalization Efficiency of TAT Conjugated Nanoparticles
- Author
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Imran I. Patel, Nevena Todorova, Benjamin R. Simona, Irene Yarovsky, Molly M. Stevens, Morgan Mager, and Ciro Chiappini
- Subjects
cell-penetrating peptides ,Technology ,Chemistry, Multidisciplinary ,Cell ,Lipid Bilayers ,Nanoparticle ,LIPOSOMES ,02 engineering and technology ,01 natural sciences ,functionalized nanoparticles ,MODIFIED GOLD NANOPARTICLES ,Functionalized nanoparticles ,Drug Delivery Systems ,Nanotechnology ,General Materials Science ,Lipid bilayer ,Internalization ,LIPID-BILAYERS ,INTRACELLULAR DELIVERY ,media_common ,Chemistry, Physical ,Physics ,Temperature ,Permeation ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Chemistry ,Membrane ,medicine.anatomical_structure ,Physics, Condensed Matter ,Physical Sciences ,Science & Technology - Other Topics ,tat Gene Products, Human Immunodeficiency Virus ,0210 nano-technology ,Materials science ,DOMAINS ,PROTEINS ,media_common.quotation_subject ,Materials Science ,education ,BIOLOGY ,Bioengineering ,Materials Science, Multidisciplinary ,Conjugated system ,Molecular Dynamics Simulation ,010402 general chemistry ,Article ,Physics, Applied ,Microscopy, Electron, Transmission ,MONOLAYER-PROTECTED NANOPARTICLES ,MD Multidisciplinary ,medicine ,Humans ,Computer Simulation ,Nanoscience & Nanotechnology ,Science & Technology ,Mechanical Engineering ,Water ,General Chemistry ,Cell internalization ,molecular dynamics ,0104 chemical sciences ,SIZE ,Biophysics ,PENETRATING PEPTIDES ,Nanoparticles ,Gold ,Peptides ,HeLa Cells - Abstract
Functionalizing nanoparticles with cell-penetrating peptides is a popular choice for cellular delivery. We investigated the effects of TAT peptide concentration and arrangement in solution on functionalized nanoparticles’ efficacy for membrane permeation. We found that cell internalization correlates with the positive charge distribution achieved prior to nanoparticle encountering interactions with membrane. We identified a combination of solution based properties required to maximize the internalization efficacy of TAT-functionalized nanoparticles.
- Published
- 2014
27. Determination using synchrotron radiation-based Fourier transform infrared microspectroscopy of putative stem cells in human adenocarcinoma of the intestine: corresponding benign tissue as a template
- Author
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Giulia Veronesi, Marine Cotte, Imran I. Patel, Valon Llabjani, Abdullah A. Ahmadzai, Helen F. Stringfellow, Francis Martin, and Pierre L. Martin-Hirsch
- Subjects
In situ ,Cell type ,Colon ,Population ,Crypt ,Analytical chemistry ,Lumen (anatomy) ,Adenocarcinoma ,Aberrant Crypt Foci ,Intestinal Neoplasms ,Intestine, Small ,Spectroscopy, Fourier Transform Infrared ,medicine ,Image Processing, Computer-Assisted ,Humans ,education ,Instrumentation ,Spectroscopy ,education.field_of_study ,Chemistry ,Histocytochemistry ,Stem Cells ,medicine.disease ,Molecular biology ,Small intestine ,medicine.anatomical_structure ,Phenotype ,Stem cell ,Synchrotrons - Abstract
The epithelial-cell layer lining the two morphologically and functionally distinct segments of the mammalian intestinal tract, small intestine, and colon is constantly being renewed. This renewal is necessitated by a harsh lumen environment and is hypothesized to be driven by a small population of stem cells (SCs) that are believed to reside at the base of intestinal crypts. A lack of specific markers has hampered previous attempts to identify their exact location. We obtained tissue sections containing small intestine and colon crypts derived from normal (benign) or adenocarcinoma (AC) human intestine. The samples were floated onto BaF2 windows and analyzed using synchrotron radiation-based Fourier transform infrared microspectroscopy via an aperture size of 10 × 10 μm. Derived infrared (IR) spectral data was then analyzed using principal component analysis and/or linear discriminant analysis. Hypothesized cell types (as a function of aperture location along the length of individual crypts) within benign crypts were classed based on exploratory unsupervised IR spectral point clustering. Scores plots derived from individual small intestine crypts consistently generated one or two distinct spectra that clustered away from the remaining cell categories; these were retrospectively classed as “distinct base region” spectra. In these plots, a clear progression of locations along crypt lengths designated as from putative stem cells (SCs) to transit-amplifying (TA) cells to terminally differentiated (TD) cells was observed in benign small intestine and colon crypts. This progression of spectral points was crypt specific, pointing away from a unifying cell lineage model in human intestinal crypts. On comparison of AC-derived spectra versus corresponding benign, a subpopulation of AC-derived spectra suggested a putative SC-like spectral fingerprint; remaining IR spectra were classed as exhibiting TA cell-like or TD cell-like spectral characteristics. These observations could point to a cancer SC phenotype; an approach capable of identifying their in situ location has enormous therapeutic applications.
- Published
- 2014
28. Gold nanoparticles explore cells: cellular uptake and their use as intracellular probes
- Author
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Sumeet Mahajan, Anna Huefner, Imran I. Patel, Wei-Li Kuan, Bodo D. Wilts, Dedy Septiadi, Alexandra M. C. Fragniere, and Roger A. Barker
- Subjects
Cytoplasm ,Chemistry ,Cell ,Metal Nanoparticles ,Nanoparticle ,Nanotechnology ,Surface-enhanced Raman spectroscopy ,Spectrum Analysis, Raman ,Endocytosis ,General Biochemistry, Genetics and Molecular Biology ,Nanomaterials ,Imaging, Three-Dimensional ,medicine.anatomical_structure ,Cell Tracking ,Colloidal gold ,medicine ,Humans ,Gold ,Molecular Biology ,Intracellular - Abstract
Understanding uptake of nanomaterials by cells and their use for intracellular sensing is important for studying their interaction and toxicology as well as for obtaining new biological insight. Here, we investigate cellular uptake and intracellular dynamics of gold nanoparticles and demonstrate their use in reporting chemical information from the endocytotic pathway and cytoplasm. The intracellular gold nanoparticles serve as probes for surface-enhanced Raman spectroscopy (SERS) allowing for biochemical characterisation of their local environment. In particular, in this work we compare intracellular SERS using non-functionalised and functionalised nanoparticles in their ability to segregate different but closely related cell phenotypes. The results indicate that functionalised gold nanoparticles are more efficient in distinguishing between different types of cells. Our studies pave the way for understanding the uptake of gold nanoparticles and their utilisation for SERS to give rise to a greater biochemical understanding in cell-based therapies.
- Published
- 2014
29. MGMT promoter hypermethylation and K-RAS, PTEN and TP53 mutations in tamoxifen-exposed and non-exposed endometrial cancer cases
- Author
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Siân E. Taylor, Eszter Nagy, David H. Phillips, Imran I. Patel, Ketan Gajjar, Pierre L. Martin-Hirsch, Helen F. Stringfellow, and Francis Martin
- Subjects
Selective Estrogen Receptor Modulators ,PTEN ,Cancer Research ,DNA repair ,Biology ,medicine.disease_cause ,Epigenesis, Genetic ,Proto-Oncogene Proteins p21(ras) ,Endometrium ,Germline mutation ,medicine ,Humans ,TP53 ,Promoter Regions, Genetic ,skin and connective tissue diseases ,DNA Modification Methylases ,Aged ,B290 ,Mutation ,tamoxifen ,epigenetics ,Base Sequence ,Tumor Suppressor Proteins ,Endometrial cancer ,Estrogen Antagonists ,PTEN Phosphohydrolase ,O-6-methylguanine-DNA methyltransferase ,Sequence Analysis, DNA ,DNA Methylation ,medicine.disease ,Endometrial Neoplasms ,hypermethylation ,Gene Expression Regulation, Neoplastic ,DNA Repair Enzymes ,Oncology ,endometrial cancer ,DNA methylation ,biology.protein ,Cancer research ,Female ,Tumor Suppressor Protein p53 ,Translational Therapeutics ,K-RAS ,Tamoxifen ,medicine.drug - Abstract
Background: Tamoxifen has anti-oestrogenic and anti-tumour activity in the breast, but is oestrogenic and carcinogenic in the endometrium. It can induce experimental tumours by both hormonal and DNA-damaging mechanisms, but its carcinogenic mode of action in human endometrium remains unclear. Methods: We investigated whether an epigenetic mechanism, involving promoter hypermethylation of the gene for the DNA repair enzyme MGMT (O6-methylguanine DNA methyltransferase), was associated with K-RAS, TP53 and PTEN mutations in endometrial tumours from women treated with tamoxifen (TAM, n=30) or unexposed to the drug (EC, n=38). Results: There were significant (PA, occurred in small numbers in both groups. TP53 mutations were of mainly A>G, C>T and indel modifications in both groups, but more frequent in TAM cases. PTEN mutations dominated in EC tumours and were of the type that has large impact on protein function, such as indel or nonsense mutations. These observations alongside the mutational spectrum in PTEN suggest that the malignancies arise from different backgrounds, hence pointing to an effect of tamoxifen. Both groups displayed MGMT promoter hypermethylation. This coincided with mutations more frequently in the TAM (78%) than in the EC (50%) group, even though there were significantly (P
- Published
- 2014
30. Audit of the job satisfaction levels of the UK radiography and physics workforce in UK radiotherapy centres 2012
- Author
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Imran I. Patel, J. Massey, Charlotte Beardmore, D. Hutton, Heidi Probst, and H. Wong
- Subjects
Male ,Clinical audit ,medicine.medical_specialty ,education ,Workload ,Audit ,Burnout ,Job Satisfaction ,State Medicine ,Nursing ,Physicians ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,Burnout, Professional ,Response rate (survey) ,Clinical Audit ,Full Paper ,business.industry ,Physics ,General Medicine ,Middle Aged ,United Kingdom ,Family medicine ,Workforce ,Workforce planning ,Female ,Job satisfaction ,Radiology ,business - Abstract
Conclusion: Radiotherapy professionals are prone to the effects of compassion fatigue and burnout. Attention must be paid to workload and its impact on practitioners' job satisfaction. Professional development that is supported and informed by a performance development review is a simple and effective means of enhancing satisfaction. Individuals have a responsibility to themselves and their colleagues as their behaviours and attitudes influence job satisfaction.\ud Advances in knowledge: This work identifies areas for future research to enhance the professional resilience of practitioners, in order to provide high-quality treatments.\ud Objective: Workforce planning reports identify a staff shortfall that jeopardizes the ability of UK radiotherapy centres to meet future demands. Obtaining an understanding of the work experiences of radiotherapy professionals will support the development of strategies to increase job satisfaction, productivity and effectiveness.\ud Methods: A quantitative survey assessed job satisfaction, attitudes to incident reporting, stress and burnout, opportunities for professional development, workload, retention and turnover. Clinical oncologists were not included, as the Royal College of Radiologists, London, UK, had recently assessed their members' satisfaction. All questions were taken from validated instruments or adapted from the "UK National Health Service Staff Survey".\ud Results: The survey yielded 658 completed responses (approximately 16% response rate), from public and private sectors. Over a third (36%) of respondents were classified as satisfied for job satisfaction with 11% dissatisfied and the remaining 53% ambivalent. A significant proportion of clinical staff (37.5%) report high emotional exhaustion. Presenteeism was an issue with 42.4% attending work despite feeling unable to fulfil their role.
- Published
- 2014
31. EP-1438: A comparative treatment planning study for Ewings sarcoma: protons vs. photons
- Author
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Ranald I Mackay, Imran I. Patel, J Handley, A. Aitkenhead, Matthew Clarke, M. Trainer, and E. Smith
- Subjects
Physics ,medicine.medical_specialty ,business.industry ,Hematology ,medicine.disease ,Oncology ,Radiology Nuclear Medicine and imaging ,medicine ,Radiology, Nuclear Medicine and imaging ,Medical physics ,Sarcoma ,Nuclear medicine ,business ,Radiation treatment planning - Published
- 2015
32. Diagnostic segregation of human brain tumours using Fourier-transform infrared and/or Raman spectroscopy coupled with discriminant analysis
- Author
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Ketan Gajjar, Katherine M. Ashton, Lara D. Heppenstall, Helen F. Stringfellow, Valon Llabjani, Weiyi Pang, Francis Martin, Timothy Dawson, Júlio Trevisan, Imran I. Patel, and Pierre L. Martin-Hirsch
- Subjects
Pathology ,medicine.medical_specialty ,Chemistry ,General Chemical Engineering ,General Engineering ,Human brain ,medicine.disease ,Linear discriminant analysis ,Bioinformatics ,Article ,Analytical Chemistry ,Meningioma ,symbols.namesake ,medicine.anatomical_structure ,Glioma ,medicine ,symbols ,Medical imaging ,Spectroscopy ,Raman spectroscopy ,Brain metastasis - Abstract
The most common initial treatment received by patients with a brain tumour is surgical removal of the growth. Precise histopathological diagnosis of brain tumours is to some extent subjective. Furthermore, currently available diagnostic imaging techniques to delineate the excision border during cytoreductive surgery lack the required spatial precision to aid surgeons. We set out to determine whether infrared (IR) and/or Raman spectroscopy combined with multivariate analysis could be applied to discriminate between normal brain tissue and different tumour types (meningioma, glioma and brain metastasis) based on the unique spectral "fingerprints" of their biochemical composition. Formalin-fixed paraffin-embedded tissue blocks of normal brain and different brain tumours were de-waxed, mounted on low-E slides and desiccated before being analyzed using attenuated total reflection Fourier-transform IR (ATR-FTIR) and Raman spectroscopy. ATR-FTIR spectroscopy showed a clear segregation between normal and different tumour subtypes. Discrimination of tumour classes was also apparent with Raman spectroscopy. Further analysis of spectral data revealed changes in brain biochemical structure associated with different tumours. Decreased tentatively-assigned lipid-to-protein ratio was associated with increased tumour progression. Alteration in cholesterol esters-to-phenylalanine ratio was evident in grade IV glioma and metastatic tumours. The current study indicates that IR and/or Raman spectroscopy have the potential to provide a novel diagnostic approach in the accurate diagnosis of brain tumours and have potential for application in intra-operative diagnosis.
- Published
- 2013
33. CARS based label-free assay for assessment of drugs by monitoring lipid droplets in tumour cells
- Author
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Christian, Steuwe, Imran I, Patel, Mahmud, Ul-Hasan, Alexander, Schreiner, Joan, Boren, Kevin M, Brindle, Stefanie, Reichelt, and Sumeet, Mahajan
- Subjects
Cytoplasm ,Antineoplastic Agents ,Apoptosis ,Lipid Droplets ,HCT116 Cells ,Spectrum Analysis, Raman ,Staurosporine ,Lipids ,Microscopy, Fluorescence ,Cell Line, Tumor ,Neoplasms ,Humans ,Camptothecin ,Drug Screening Assays, Antitumor ,Algorithms ,Cell Proliferation ,Etoposide ,Fluorescent Dyes - Abstract
Coherent anti-Stokes Raman scattering (CARS) is becoming an established tool for label-free multi-photon imaging based on molecule specific vibrations in the sample. The technique has proven to be particularly useful for imaging lipids, which are abundant in cells and tissues, including cytoplasmic lipid droplets (LD), which are recognized as dynamic organelles involved in many cellular functions. The increase in the number of lipid droplets in cells undergoing cell proliferation is a common feature in many neoplastic processes [1] and an increase in LD number also appears to be an early marker of drug-induced cell stress and subsequent apoptosis [3]. In this paper, a CARS-based label-free method is presented to monitor the increase in LD content in HCT116 colon tumour cells treated with the chemotherapeutic drugs Etoposide, Camptothecin and the protein kinase inhibitor Staurosporine. Using CARS, LDs can easily be distinguished from other cell components without the application of fluorescent dyes and provides a label-free non-invasive drug screening assay that could be used not only with cells and tissues ex vivo but potentially also in vivo.
- Published
- 2013
34. Sub-cellular spectrochemical imaging of isolated human corneal cells employing synchrotron radiation-based Fourier-transform infrared microspectroscopy
- Author
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Júlio Trevisan, Imran I. Patel, Takahiro Nakamura, Carol J. Hirschmugl, Francis Martin, Nigel J. Fullwood, and Simon W. Fogarty
- Subjects
In situ ,Infrared ,Cell ,Analytical chemistry ,Intracellular Space ,Infrared spectroscopy ,Synchrotron radiation ,Cell Separation ,Biochemistry ,Analytical Chemistry ,Cornea ,Spectroscopy, Fourier Transform Infrared ,Electrochemistry ,medicine ,Environmental Chemistry ,Humans ,Spectroscopy ,Principal Component Analysis ,Chemistry ,Discriminant Analysis ,Cell sorting ,Molecular Imaging ,medicine.anatomical_structure ,Biophysics ,Microtechnology ,Stem cell ,Synchrotrons - Abstract
Understanding stem cell (SC) biology remains challenging and one of the few human tissues within which their in situ location is well characterized is the cornea. Individual human corneal epithelial cells were isolated from biopsies of live tissues using fluorescence-activated cell sorting (FACS); these were divided into putative SCs, transit-amplifying (TA) cells and terminally-differentiated (TD) cells. Employing synchrotron radiation-based Fourier-transform infrared (SR-FTIR) microspectroscopy with a focal plane array (FPA), sub-cellular spatial resolution analysis of unstained isolated cells was achieved as a consequence of the brilliance of a 12 collimated beams arrangement allowing rapid spectral acquisition. Infrared (IR) spectra were extracted and pre-processed. Subsequent categorization with multivariate analysis of IR spectra derived from FPA images was used to investigate biomolecular changes between classes. A progressive segregation in cell-specific spectral categories with differentiation from SC to TA cell to TD cell was noted. Multiple different absorption peaks that discriminated putative SCs, TA cells and TD cells across DNA, protein and lipid spectral regions were identified. DNA regions (1080 and 1225 cm(-1)) and some protein regions (1443 cm(-1)) primarily segregated SCs from TA cells and TD cells, whilst amide regions and lipids (1,550, 1650 and 1740 cm(-1)) segregated TA cells and TD cells. Scanning electron microscopy images verified the external phenotypic characteristics of the different isolated cell types. These findings highlight the applicability of SR-FTIR microspectroscopy towards distinguishing SCs, TA cells and TD cells, and suggest that cellular classification via traditional methods of immunolabelling can be greatly aided by the use of spectral biomarkers.
- Published
- 2012
35. Isolating stem cells in the inter-follicular epidermis employing synchrotron radiation-based Fourier-transform infrared microspectroscopy and focal plane array imaging
- Author
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Imran I. Patel, Wesley J. Harrison, Katia Wehbe, Francis Martin, Paul L. Carmichael, Jacob Filik, Michael P. Philpott, Gianfelice Cinque, Andrew D. Scott, Jemma G. Kerns, and Mark D. Frogley
- Subjects
chemistry.chemical_classification ,Epidermis (botany) ,Infrared ,Biomolecule ,Stem Cells ,Analytical chemistry ,Synchrotron radiation ,Infrared spectroscopy ,Cell Differentiation ,Biochemistry ,Analytical Chemistry ,Molecular Imaging ,Absorbance ,Nuclear magnetic resonance ,chemistry ,Epidermal Cells ,Spectroscopy, Fourier Transform Infrared ,Humans ,Fourier transform infrared spectroscopy ,Epidermis ,Spectroscopy ,Hair Follicle ,Biomarkers - Abstract
Normal function and physiology of the epidermis is maintained by the regenerative capacity of this tissue via adult stem cells (SCs). However, definitive identifying markers for SCs remain elusive. Infrared (IR) spectroscopy exploits the ability of cellular biomolecules to absorb in the mid-IR region (λ = 2.5-25 μm), detecting vibrational transitions of chemical bonds. In this study, we exploited the cell's inherent biochemical composition to discriminate SCs of the inter-follicular skin epidermis based on IR-derived markers. Paraffin-embedded samples of human scalp skin (n = 4) were obtained, and 10-μm thick sections were mounted for IR spectroscopy. Samples were interrogated in transmission mode using synchrotron radiation-based Fourier-transform IR (FTIR) microspectroscopy (15 × 15 μm) and also imaged employing globar-source FTIR focal plane array (FPA) imaging (5.4 × 5.4 μm). Dependent on the location of derived spectra, wavenumber-absorbance/intensity relationships were examined using unsupervised principal component analysis. This approach showed clear separation and spectral differences dependent on cell type. Spectral biomarkers concurrently associated with segregation of SCs, transit-amplifying cells and terminally-differentiated cells of epidermis were primarily PO(2)(-) vibrational modes (1,225 and 1,080 cm(-1)), related to DNA conformational alterations. FPA imaging coupled with hierarchical cluster analysis also indicated the presence of specific basal layer cells potentially originating from the follicular bulge, suggested by co-clustering of spectra. This study highlights PO (2) (-) vibrational modes as potential putative SC markers.
- Published
- 2012
36. Classification of test agent-specific effects in the Syrian hamster embryo assay (pH 6.7) using infrared spectroscopy with computational analysis
- Author
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Júlio Trevisan, Nigel J. Fullwood, Abdullah A. Ahmadzai, Francis Martin, Kamala Pant, Andrew D. Scott, Shannon W. Bruce, Imran I. Patel, Weiyi Pang, and Paul L. Carmichael
- Subjects
Health, Toxicology and Mutagenesis ,Hamster ,Infrared spectroscopy ,Biology ,Toxicology ,In vivo ,Cricetinae ,Spectroscopy, Fourier Transform Infrared ,Genetics ,medicine ,Bioassay ,Animals ,Genetics (clinical) ,Carcinogen ,Cells, Cultured ,Mesocricetus ,Mutagenicity Tests ,Hydrogen-Ion Concentration ,Embryo, Mammalian ,Transformation (genetics) ,Cell Transformation, Neoplastic ,Biochemistry ,Mechanism of action ,Attenuated total reflection ,Data Interpretation, Statistical ,Carcinogens ,Linear Models ,medicine.symptom ,Biomarkers ,Mutagens - Abstract
The Syrian hamster embryo (SHE) cell transformation assay (pH 6.7) has utility in the assessment of potential chemical carcinogenicity (both genotoxic and non-genotoxic mechanisms of action). The assay uses morphological transformation as an end point and has a reported sensitivity of 87%, specificity of 83% and overall concordance of 85% with in vivo rodent bioassay data. However, the scoring of morphologically transformed SHE cells is subjective. We treated SHE cells grown on low-E reflective slides with benzo[a]pyrene, 3-methylcholanthrene, anthracene, N-nitroso-N-methylnitroguanidine, ortho-toluidine HCl, 2,4-diaminotoluene or D-mannitol for 7 days before fixation with methanol. Identified colonies were interrogated by acquiring a minimum of five infrared (IR) spectra per colony using attenuated total reflection Fourier-transform IR spectroscopy. Individual IR spectra were acquired over a spatial area of approximately 250 x 250 mu m. Resultant data were analysed using Fisher's linear discriminant analysis and feature histogram algorithms to extract classifying biomarkers of test agent-specific effects or transformation in SHE cells. Clustering of spectral points suggested co-segregation or discrimination of test agent categories based on mechanism of action. Towards transformation, unifying alterations were associated with alterations in the Amide I and Amide II peaks; these were consistently major classifying biomarkers for transformed versus non-transformed SHE cells. Our approach highlights a novel method towards objectively screening and classifying SHE cells, be it to ascertain test agent treatment based on mechanism of action or transformation.
- Published
- 2012
37. Alterations in the biomolecular signatures of developing chick corneas as determined by biospectroscopy and multivariate analysis
- Author
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Abdullah A. Ahmadzai, Andrew J. Quantock, Weiyi Pang, Melody Liles, Francis Martin, Xiaoqiang Qiu, and Imran I. Patel
- Subjects
chemistry.chemical_classification ,Principal Component Analysis ,Chemistry ,RNA ,Chick Embryo ,DNA ,Spectrum Analysis, Raman ,Amino acid ,Protein Structure, Tertiary ,Cornea ,chemistry.chemical_compound ,symbols.namesake ,Protein structure ,Biochemistry ,Valine ,Multivariate Analysis ,Spectroscopy, Fourier Transform Infrared ,symbols ,Animals ,Tyrosine ,Spectroscopy ,Raman spectroscopy ,Biomarkers - Abstract
PURPOSE: Biospectroscopy tools are increasingly being recognized as novel approaches toward interrogating complex biological structures in a nondestructive fashion. This study was conducted to apply these tools to interrogate alterations in the molecular signatures of developing chick corneas during the onset and development of transparency. METHODS: Embryonic chick corneas (n = 46) were obtained at 2-day intervals from embryonic day (E)10 to E18 of incubation and investigated with attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy and Raman microspectroscopy. Resultant spectra were analyzed for variance by using principal component analysis and linear discriminant analysis (PCA-LDA). RESULTS: Mean spectra after ATR-FTIR spectroscopy or Raman microspectroscopy derived from corneas at each developmental stage showed some overlap; however, in PCA-LDA scores plots, a clear segregation of spectra was evident, and two-category discrimination indicated that significant molecular alterations occur during tissue morphogenesis. Notable by both techniques was the increasing intensity of DNA signal (1080 cm⁻¹) from E10 onward. Major segregating biomarkers identified by ATR-FTIR spectroscopy between E10 and E18 were in the DNA/RNA (1126 cm⁻¹), glycogen (1045 cm⁻¹), protein (1470 cm⁻¹), and amide II (1512 cm⁻¹ and 1524 cm⁻¹) spectral regions. Raman spectroscopy also identified major distinguishing vibrational modes that included proteins, amino acids (tyrosine, proline phenylalanine, and valine), and secondary structures of proteins (amide I and amide II). CONCLUSIONS: The developing chick cornea undergoes significant changes in its biomolecular composition in the E10 to E18 developmental period, with the major changes occurring in the spectral regions associated with DNA/RNA, proteins, glycogen, and secondary protein structures.
- Published
- 2012
38. Segregation of human prostate tissues classified high-risk (UK) versus low-risk (India) for adenocarcinoma using Fourier-transform infrared or Raman microspectroscopy coupled with discriminant analysis
- Author
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Júlio Trevisan, Shyam S. Matanhelia, Francis Martin, R. K. Gopala Krishnan, Imran I. Patel, Caroline M. Nicholson, and Paras B. Singh
- Subjects
Male ,Infrared spectroscopy ,India ,Phenylalanine ,Adenocarcinoma ,Spectrum Analysis, Raman ,Biochemistry ,Analytical Chemistry ,chemistry.chemical_compound ,Prostate cancer ,Risk Factors ,Amide ,Spectroscopy, Fourier Transform Infrared ,medicine ,Humans ,Protein secondary structure ,Aged ,Aged, 80 and over ,RNA ,Discriminant Analysis ,Prostatic Neoplasms ,Middle Aged ,medicine.disease ,United Kingdom ,chemistry ,Disease Susceptibility ,DNA ,Biomarkers - Abstract
Vibrational spectroscopy techniques can be applied to identify a susceptibility-to-adenocarcinoma biochemical signature. A sevenfold difference in incidence of prostate adenocarcinoma (CaP) remains apparent amongst populations of low- (e.g. India) compared with high-risk (e.g. UK) regions, with migrant studies implicating environmental and/or lifestyle/dietary causative factors. This study set out to determine the biospectroscopy-derived spectral differences between risk-associated cohorts to CaP. Benign prostate tissues were obtained using transurethral resection from high-risk (n = 11, UK) and low-risk (n = 14, India) cohorts. Samples were analysed using attenuated total reflection Fourier-transform infrared (FTIR) spectroscopy, FTIR microspectroscopy and Raman microspectroscopy. Spectra were subsequently processed within the biochemical cell region (1,800(-1)-500 cm(-1)) employing principal component analysis (PCA) and linear discriminant analysis (LDA) to determine whether wavenumber-absorbance/intensity relationships might reveal biochemical differences associated with region-specific susceptibility to CaP. PCA-LDA scores and corresponding cluster vector plots identified pivotal segregating biomarkers as 1,582 cm(-1) (Amide I/II trough); 1,551 cm(-1) (Amide II); 1,667 cm(-1) (Amide I); 1,080 cm(-1) (DNA/RNA); 1,541 cm(-1) (Amide II); 1,468 cm(-1) (protein); 1,232 cm(-1) (DNA); 1,003 cm(-1) (phenylalanine); 1,632 cm(-1) [right-hand side (RHS) Amide I] for glandular epithelium (P0.0001) and 1,663 cm(-1) (Amide I); 1,624 cm(-1) (RHS Amide I); 1,126 cm(-1) (RNA); 1,761, 1,782, 1,497 cm(-1) (RHS Amide II); 1,003 cm(-1) (phenylalanine); and 1,624 cm(-1) (RHS Amide I) for adjacent stroma (P0.0001). Primarily protein secondary structure variations were biomolecular markers responsible for cohort segregation with DNA alterations exclusively located in the glandular epithelial layers. These biochemical differences may lend vital insights into the aetiology of CaP.
- Published
- 2011
39. Raman scattering in InAsxSbyP1xy alloys grown by gas source MBE
- Author
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Chong-Rong Wu, Francis Martin, K. J. Cheetham, J.-S. Tzeng, Anthony Krier, Imran I. Patel, Hao-Hsiung Lin, Department of Physics [Lancaster], Lancaster University, Lancaster Environment Centre, Graduate Institute of Electronics Engineering [Taipei] (GIEE), and National Taiwan University [Taiwan] (NTU)
- Subjects
Acoustics and Ultrasonics ,Phonon ,Spinodal decomposition ,Alloy ,Analytical chemistry ,02 engineering and technology ,engineering.material ,Epitaxy ,01 natural sciences ,Condensed Matter::Materials Science ,symbols.namesake ,chemistry.chemical_compound ,Condensed Matter::Superconductivity ,0103 physical sciences ,Chemical composition ,ComputingMilieux_MISCELLANEOUS ,010302 applied physics ,Chemistry ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Physical Sciences ,symbols ,Indium phosphide ,engineering ,0210 nano-technology ,Raman spectroscopy ,Raman scattering - Abstract
The Raman spectra of quaternary InAs x Sb y P1−x−y epitaxial layers nominally lattice-matched to (1 0 0) n-type InAs substrates are reported. The phonon peaks are identified for alloys covering a wide composition range extending into the miscibility gap. Three-mode behaviour was obtained across part of the composition range. InP-like longitudinal optical (LO) and transverse optical (TO) phonons were observed over the entire compositional range, but InAs-like LO phonons were only observed at high arsenic concentrations and no InSb-like TO phonons were observed. Disorder-related phonon peaks were obtained for alloy compositions within the miscibility gap.
- Published
- 2011
40. Distinguishing cell types or populations based on the computational analysis of their infrared spectra
- Author
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Júlio Trevisan, Jemma G. Kelly, Valon Llabjani, Imran I. Patel, Michael J. Walsh, Pierre L. Martin-Hirsch, Nigel J. Fullwood, and Francis Martin
- Subjects
Complex data type ,Principal Component Analysis ,Materials science ,Spectrophotometry, Infrared ,Infrared ,Infrared spectroscopy ,Discriminant Analysis ,Linear discriminant analysis ,General Biochemistry, Genetics and Molecular Biology ,Principal component analysis ,Animals ,Humans ,Sample preparation ,Spectroscopy ,Biological system ,Cluster analysis - Abstract
Infrared (IR) spectroscopy of intact cells results in a fingerprint of their biochemistry in the form of an IR spectrum; this has given rise to the new field of biospectroscopy. This protocol describes sample preparation (a tissue section or cytology specimen), the application of IR spectroscopy tools, and computational analysis. Experimental considerations include optimization of specimen preparation, objective acquisition of a sufficient number of spectra, linking of the derived spectra with tissue architecture or cell type, and computational analysis. The preparation of multiple specimens (up to 50) takes 8 h; the interrogation of a tissue section can take up to 6 h (∼100 spectra); and cytology analysis (n = 50, 10 spectra per specimen) takes 14 h. IR spectroscopy generates complex data sets and analyses are best when initially based on a multivariate approach (principal component analysis with or without linear discriminant analysis). This results in the identification of class clustering as well as class-specific chemical entities.
- Published
- 2010
41. Discrimination of zone-specific spectral signatures in normal human prostate using Raman spectroscopy
- Author
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Imran I. Patel and Francis Martin
- Subjects
Male ,Central Zone ,Stromal cell ,Prostatic Hyperplasia ,Spectrum Analysis, Raman ,Biochemistry ,Analytical Chemistry ,symbols.namesake ,chemistry.chemical_compound ,Prostate ,Electrochemistry ,medicine ,Environmental Chemistry ,Humans ,Spectroscopy ,Transition (genetics) ,RNA ,Prostatic Neoplasms ,Middle Aged ,Molecular biology ,language.human_language ,medicine.anatomical_structure ,chemistry ,language ,symbols ,Raman spectroscopy ,DNA ,Cytosine - Abstract
The prostate gland is the most common site of pathology in human males. Using the urethra as an anatomical reference point, it can be divided into three distinct zones known as the transition zone (TZ), peripheral zone (PZ) and central zone (CZ). The pathological conditions of benign prostatic hypertrophy and/or prostate adenocarcinoma are highly prevalent in this gland. This preliminary study set out to determine whether biochemical intra-individual differences between normal prostate zones could be identified using Raman spectroscopy with subsequent exploratory analyses. A normal (benign) prostate transverse tissue section perpendicular to the rectal surface and above the verumontanum was obtained in a paraffin-embedded block. A 10-µm-thick slice was floated onto a gold substrate, de-waxed and analysed using Raman spectroscopy (200 epithelial-cell and 140 stromal spectra/zone). Raman spectra were subsequently processed in the 1800-367 cm(-1) spectral region employing principal component analysis (PCA) to determine whether wavenumber-intensity relationships expressed as single points in hyperspace might reveal biochemical differences associated with inter-zone pathological susceptibility. Visualisation of PCA scores plots and their corresponding loadings plots highlighted 781 cm(-1) (cytosine/uracil) and 787 cm(-1) (DNA) as the key discriminating factors segregating PZ from less susceptible TZ and CZ epithelia (P0.001). Conversely, 1459 cm(-1) (lipids and proteins) and 1003 cm(-1) (phenylalanine) were identified as the key biochemical factor distinguishing TZ from CZ epithelia (P0.05). All stromal zones were discriminated by the protein/lipid region (1459 cm(-1) and 1100 cm(-1)) with DNA/RNA region (781 cm(-1) and 787 cm(-1)) only highlighted between PZ and CZ (P0.05). This novel approach identifies biochemical markers that may have aetiological functional roles towards susceptibility of human prostate zones to specific pathological conditions.
- Published
- 2010
42. Syrian hamster embryo (SHE) assay (pH 6.7) coupled with infrared spectroscopy and chemometrics towards toxicological assessment
- Author
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Imran I. Patel, Andrew D. Scott, Júlio Trevisan, Valon Llabjani, Karen T. Cheung, Paul L. Carmichael, Shannon W. Bruce, Ghazal M. Najand, Francis Martin, Kamala Pant, Plamen Angelov, and Hubert M. Pollock
- Subjects
Stereochemistry ,Hamster ,Infrared spectroscopy ,Biochemistry ,Fourier transform spectroscopy ,Analytical Chemistry ,Chemometrics ,In vivo ,Cricetinae ,Spectroscopy, Fourier Transform Infrared ,Electrochemistry ,Environmental Chemistry ,Animals ,Sample preparation ,Fourier transform infrared spectroscopy ,Organic Chemicals ,Spectroscopy ,Principal Component Analysis ,Chromatography ,Mesocricetus ,Chemistry ,Discriminant Analysis ,Embryo, Mammalian ,Cell Transformation, Neoplastic ,Attenuated total reflection ,Biological Assay - Abstract
The Syrian hamster embryo (SHE) assay (pH 6.7) is an in vitro candidate to replace in vivo carcinogenicity tests. However, the conventional method of visual scoring of foci (non-transformed vs. transformed colonies) can be time-consuming and is open to subjectivity. Infrared (IR) spectroscopy has the potential to provide objective assessment of such SHE colonies with the added advantage of potentially providing mechanistic information. In this study, SHE cells were treated with one of eight different chemical regimens, allowed in culture to attach and form foci on IR-reflective glass slides; these were subsequently interrogated by attenuated total reflection (ATR) Fourier-transform IR (FTIR) spectroscopy. Derived mid-IR spectra (n = 13,406) were subjected to chemometric analysis focusing primarily on the extraction of biochemical information related to test agent treatment and/or morphological transformation. The use of ATR-FTIR spectroscopy with chemometrics to analyze the SHE assay is a novel approach to toxicological assessment.
- Published
- 2010
43. Elevated oestrogen receptor splice variant ERαΔ5 expression in tumour-adjacent hormone-responsive tissue
- Author
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Caroline M. Nicholson, Helen F. Stringfellow, Francis Martin, Siân E. Taylor, Imran I. Patel, Shyam S. Matanhelia, Paras B. Singh, R. K. Gopala Krishna, and Pierre L. Martin-Hirsch
- Subjects
Gene isoform ,Male ,medicine.medical_specialty ,DNA, Complementary ,Neoplasms, Hormone-Dependent ,splice variant ,Health, Toxicology and Mutagenesis ,RNA Splicing ,lcsh:Medicine ,Biology ,Endometrium ,Article ,Prostate cancer ,Prostate ,Internal medicine ,medicine ,Humans ,splice ,DNA Primers ,Base Sequence ,Reverse Transcriptase Polymerase Chain Reaction ,lcsh:R ,Public Health, Environmental and Occupational Health ,Estrogen Receptor alpha ,Cancer ,Prostatic Neoplasms ,real-time RT PCR ,medicine.disease ,prostate cancer ,Reverse transcriptase ,Endometrial Neoplasms ,oestrogen receptor ,medicine.anatomical_structure ,Endocrinology ,Microscopy, Fluorescence ,endometrial cancer ,Cancer research ,Female ,Estrogen receptor alpha - Abstract
Susceptibility to prostate or endometrial cancer is linked with obesity, a state of oestrogen excess. Oestrogen receptor (ER) splice variants may be responsible for the tissue-level of ER activity. Such micro-environmental regulation may modulate cancer initiation and/or progression mechanisms. Real-time reverse transcriptase (RT) polymerase chain reaction (PCR) was used to quantitatively assess the levels of four ER splice variants (ERαΔ3, ERαΔ5, ERβ2 and ERβ5), plus the full-length parent isoforms ERα and ERβ1, in high-risk [tumour-adjacent prostate (n = 10) or endometrial cancer (n = 9)] vs. low-risk [benign prostate (n = 12) or endometrium (n = 9)], as well as a comparison of UK (n = 12) vs. Indian (n = 15) benign prostate. All three tissue groups expressed the ER splice variants at similar levels, apart from ERαΔ5. This splice variant was markedly raised in all of the tumour-adjacent prostate samples compared to benign tissues. Immunofluorescence analysis for ERβ2 in prostate tissue demonstrated that such splice variants are present in comparable, if not greater, amounts as the parent full-length isoform. This small pilot study demonstrates the ubiquitous nature of ER splice variants in these tissue sites and suggests that ERαΔ5 may be involved in progression of prostate adenocarcinoma.
- Published
- 2010
44. Constitutive expression of bioactivating enzymes in normal human prostate suggests a capability to activate pro-carcinogens to DNA-damaging metabolites
- Author
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Francis L, Martin, Imran I, Patel, Osman, Sozeri, Paras B, Singh, Narasimhan, Ragavan, Caroline M, Nicholson, Eva, Frei, Walter, Meinl, Hansruedi, Glatt, David H, Phillips, and Volker M, Arlt
- Subjects
Aged, 80 and over ,Male ,Prostatectomy ,Estradiol ,Blotting, Western ,Amino-Acid N-Acetyltransferase ,Prostate ,Middle Aged ,DNA Adducts ,Gene Expression Regulation ,Cytochrome P-450 CYP1A2 ,Sex Hormone-Binding Globulin ,Cytochrome P-450 CYP1B1 ,Carcinogens ,Cytochrome P-450 CYP1A1 ,Humans ,Testosterone ,Aryl Hydrocarbon Hydroxylases ,Aged ,DNA Damage - Abstract
The constitutive bioactivating capacity of human prostate may play a role in determining risk of adenocarcinoma developing in this tissue. Expression of candidate enzymes that convert exogenous and/or endogenous agents into reactive DNA-damaging species would suggest the potential to generate initiating events in prostate cancer (CaP).Normal prostate tissues from UK-resident Caucasians (n = 10) were collected following either radical retropubic prostatectomy (RRP) or cystaprostatectomy (CyP). An analysis of gene and protein expression of candidate metabolizing enzymes, including cytochrome P450 (CYP)1A1, CYP1A2, CYP1B1, N-acetyltransferase 1 (NAT1), sulfotransferase (SULT)1A1, SULT1A3, NAD(P)H:quinone oxidoreductase (NQO1), prostaglandin H synthase 1 (cyclooxygenase 1; COX1), and CYP oxidoreductase (POR) was carried out. Quantitative real-time reverse transcriptase polymerase chain reaction, Western blot, and immunohistochemical analysis were conducted.Except for CYP1A1 and CYP1A2, the metabolizing enzymes examined appeared to be expressed with minimal inter-individual variation (in general, approximately two- to fivefold) in the expression levels. Enzymes such as CYP1B1 and NQO1 that are capable of bioactivating pro-carcinogens to reactive metabolites were readily identifiable in human prostate. Immunohistochemical analysis showed that although some expression is located in the stroma, the majority is localized to epithelial cells lining the glandular elements of the tissue; these are the cells from which CaP might arise.Constitutive expression of bioactivating enzymes confers the potential to convert a range of exogenous and/or endogenous agents to reactive species capable of inducing DNA damaging events. These findings suggest an organ capability for pro-carcinogen activation that could play an important role in the etiology of human CaP.
- Published
- 2010
45. The use of computed radiography for routine linear accelerator and simulator quality control
- Author
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T. Natarajan, Imran I. Patel, S S Hassan, and Mike Kirby
- Subjects
Quality Control ,Reproducibility ,Materials science ,business.industry ,Radiography ,X-Ray Film ,Root mean square difference ,Reproducibility of Results ,General Medicine ,Signal ,Linear particle accelerator ,Radiographic Image Enhancement ,Quality (physics) ,Maximum difference ,Image Processing, Computer-Assisted ,Humans ,Radiographic Image Interpretation, Computer-Assisted ,Radiology, Nuclear Medicine and imaging ,Computed radiography ,Particle Accelerators ,business ,Tomography, X-Ray Computed ,Simulation - Abstract
Computed radiography (CR) systems were originally developed for the purpose of clinical imaging, and there has been much work published on its effectiveness as a film replacement for this end. However, there has been little published on its use for routine linear accelerator and simulator quality control, and therefore we have evaluated the use of the Kodak 2000RT system with large Agfa CR plates as a replacement for film for this function. A prerequisite for any such use is a detailed understanding of the system behaviour, hence characteristics such as spatial uniformity of response, reproducibility of spatial accuracy, plate signal decay with time and the dose-response of plates were investigated. Finally, a comparison of results obtained using CR for the measurement of radiation field dimensions was made against those from radiographic film, and found to be in agreement within 0.1 mm (mean difference for high-resolution images, 0.3 mm root mean square difference) for megavoltage images and 0.3 mm (maximum difference) for simulator images. In conclusion, the CR system has been shown to be a good alternative to radiographic film for routine quality control of linear accelerators and simulators.
- Published
- 2009
46. EP-1665: Do radiotherapy tattoos reliably guide patient set up for breast tumour bed treatment? - A review of current practice
- Author
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H. Lander, C. Anandadas, S. Chauhan, J. Loncaster, Imran I. Patel, and Julia Stratford
- Subjects
medicine.medical_specialty ,business.industry ,General surgery ,medicine.medical_treatment ,Hematology ,Surgery ,Radiation therapy ,Oncology ,Radiology Nuclear Medicine and imaging ,Current practice ,Medicine ,Radiology, Nuclear Medicine and imaging ,business ,Set (psychology) - Published
- 2015
47. Visual acuity after Ruthenium(106) brachytherapy of choroidal melanomas
- Author
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Bertil Damato, Imran I. Patel, R. Douglas Errington, Helen Mayles, and Ian R. Campbell
- Subjects
Choroidal melanoma ,Adult ,Male ,Cancer Research ,medicine.medical_specialty ,Visual acuity ,medicine.medical_treatment ,Brachytherapy ,Visual Acuity ,Transillumination ,Single Center ,Extraocular muscles ,Tumor margin ,Medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Prospective Studies ,Melanoma ,Aged ,Aged, 80 and over ,Analysis of Variance ,Radiation ,business.industry ,Choroid Neoplasms ,Middle Aged ,eye diseases ,Surgery ,medicine.anatomical_structure ,Oncology ,Optic nerve ,Female ,medicine.symptom ,Ruthenium Radioisotopes ,business ,Nuclear medicine - Abstract
To report on conservation of visual acuity after Ruthenium(106) (Ru-106) brachytherapy of choroidal melanoma.This study was a noncomparative interventional case series of 458 patients with choroidal melanoma treated at a single center between January 1993 and December 2001. The intervention consisted of Ru-106 brachytherapy delivering minimum scleral and apex doses of 300 Gy and 80 Gy, respectively, using a 15-mm or 20-mm plaque. For discrete, posterior tumors, the plaque was positioned eccentrically with its posterior edge aligned with the posterior tumor margin. To ensure correct plaque positioning, any overlying extraocular muscles were dis-inserted, and the locations of both tumor and plaque edges were confirmed by transillumination and indentation. The main outcome measures were conservation of vision of 20/40 or better, 20/200 or better, and Counting Fingers or better, according to baseline variables.The actuarial rate of conservation of 20/40 or better was 55% at 9 years, loss of such vision correlating with posterior tumor extension (p0.001), temporal tumor location (p = 0.001), increased tumor height (p = 0.01), and older age (p0.01) (Cox multivariate analysis). Similar analyses showed conservation of 20/200 or better in 57% of eyes at 9 years, loss correlating with reduced initial visual acuity (p0.001), posterior tumor extension (p0.001), and temporal tumor location (p = 0.006). Counting Fingers or better vision was conserved in 83% of patients at 9 years, loss correlating with increased tumor height (p0.0001). Local tumor recurrence occurred in 9 patients (actuarial rate, 3% at 9 years).Ruthenium(106) brachytherapy of posterior choroidal melanoma achieves good conservation of vision if the tumor does not extend close to the optic nerve or fovea.
- Published
- 2005
48. OC-0560: Job satisfaction of the UK radiotherapy workforce: physics and radiography, a strategy to improve satisfaction
- Author
-
H. Wong, D. Hutton, A. Eddy, Imran I. Patel, J. Massey, and Heidi Probst
- Subjects
Nursing ,Oncology ,business.industry ,Radiology Nuclear Medicine and imaging ,Radiography ,Workforce ,Medicine ,Radiology, Nuclear Medicine and imaging ,Job satisfaction ,Hematology ,business - Published
- 2013
- Full Text
- View/download PDF
49. Coherent anti-Stokes Raman scattering for label-free biomedical imaging
- Author
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Christian Steuwe, Stefanie Reichelt, Sumeet Mahajan, and Imran I. Patel
- Subjects
chemistry.chemical_classification ,business.industry ,Computer science ,Biomolecule ,Nanotechnology ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,symbols.namesake ,Optics ,chemistry ,Medical imaging ,symbols ,Tumour classification ,Imaging technique ,Cars microscopy ,business ,Raman scattering ,Label free - Abstract
Coherent anti-Stokes Raman scattering (CARS) has established itself as an imaging technique capable of providing video-rate imaging of biological specimens through vibrational coherence of endogenous molecules. Current techniques predominantly involve the application of costly, invasive and potentially non-specific dyes or labels for imaging biomolecules. CARS microscopy can however provide a high-resolution and non-invasive alternative for imaging biomolecules of interest without the need for exogenous labels. Here we provide an overview of CARS including the technique and common instrumentation as well as its applications in biomedical imaging. We discuss the major biomedical areas where CARS has been applied such as in evaluating liver disease, progression of atherosclerosis, tumour classification and tracking drug delivery, whilst also assessing the future challenges for clinical translation.
- Published
- 2013
50. Biospectroscopy insights into the multi-stage process of cervical cancer development: probing for spectral biomarkers in cytology to distinguish grades
- Author
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Pierre L. Martin-Hirsch, Júlio Trevisan, Nikhil Purandare, Imran I. Patel, Walter Prendiville, Günther von Bünau, Francis Martin, Ronan Kelehan, and Noel Bolger
- Subjects
medicine.medical_specialty ,Multivariate analysis ,Cytodiagnosis ,Analytical chemistry ,Uterine Cervical Neoplasms ,Cervix Uteri ,Biochemistry ,Gastroenterology ,Analytical Chemistry ,Cytology ,Internal medicine ,Spectroscopy, Fourier Transform Infrared ,Electrochemistry ,medicine ,Humans ,Environmental Chemistry ,Least-Squares Analysis ,Early Detection of Cancer ,Spectroscopy ,Neoplasm Staging ,Vaginal Smears ,Colposcopy ,Cervical cancer ,Principal Component Analysis ,medicine.diagnostic_test ,Cervical cytology screening ,business.industry ,Cervical cytology ,medicine.disease ,Multi stage ,Dysplasia ,Case-Control Studies ,Female ,Neoplasm Grading ,business - Abstract
Cervical cancer screening programmes have greatly reduced the burden associated with this disease. However, conventional cervical cytology screening still lacks sensitivity and specificity. There is an urgent need for the development of a low-cost robust screening technique. By generating a spectral "biochemical-cell fingerprint", Fourier-transform infrared (FTIR) spectroscopy has been touted as a tool capable of segregating grades of dysplasia. A total of 529 specimens were collected over a period of one year at two colposcopy centres in Dublin, Ireland. Of these, n = 128 were conventionally classed as high-grade, n = 186 as low-grade and n = 215 as normal. Following FTIR spectroscopy, derived spectra were examined for segregation between classes in scores plots generated with subsequent multivariate analysis. A degree of crossover between classes was noted and this could be associated with imperfect conventional screening resulting in an inaccurate diagnosis or an incomplete transition between classes. Maximal crossover associated with n = 102 of 390 specimens analyzed was found between normal and low-grade specimens. However, robust spectral differences (P≤ 0.0001) were still observed at 1512 cm(-1), 1331 cm(-1) and 937 cm(-1). For high-grade vs. low-grade specimens, spectral differences (P≤ 0.0001) were observed at Amide I (1624 cm(-1)), Amide II (1551 cm(-1)) and asymmetric phosphate stretching vibrations (νasPO2(-); 1215 cm(-1)). Least crossover (n = 50 of 343 specimens analyzed) was seen when comparing high-grade vs. normal specimens; significant inter-class spectral differences (P≤ 0.0001) were noted at Amide II (1547 cm(-1)), 1400 cm(-1) and 995 cm(-1). Deeper understanding of the underlying changes in the transition between cervical cytology classes (normal vs. low-grade vs. high-grade) is required in order to develop biospectroscopy tools as a screening approach. This will then allow for the development of blind classification algorithms.
- Published
- 2013
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