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8.
Analyst ; 141(2): 416-28, 2016 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-26421636

RESUMO

Instrumental advances in infrared micro-spectroscopy have made possible the observation of individual human cells and even subcellular structures. The observed spectra represent a snapshot of the biochemical composition of a cell; this composition varies subtly but reproducibly with cellular effects such as progression through the cell cycle, cell maturation and differentiation, and disease. The aim of this summary is to provide a synopsis of the progress achieved in infrared spectral cytopathology (SCP) - the combination of infrared micro-spectroscopy and multivariate methods of analysis - for the detection of abnormalities in exfoliated human cells of the upper respiratory and digestive tract, namely the oral and nasopharyngeal cavities, and the esophagus.


Assuntos
Neoplasias Esofágicas/patologia , Programas de Rastreamento/métodos , Neoplasias Bucais/patologia , Neoplasias Nasofaríngeas/patologia , Espectrofotometria Infravermelho/métodos , Células Epiteliais/patologia , Neoplasias Esofágicas/diagnóstico , Humanos , Neoplasias Bucais/diagnóstico , Neoplasias Nasofaríngeas/diagnóstico
9.
J Biophotonics ; 6(11-12): 855-86, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24311233

RESUMO

During the last 15 years, vibrational spectroscopic methods have been developed that can be viewed as molecular pathology methods that depend on sampling the entire genome, proteome and metabolome of cells and tissues, rather than probing for the presence of selected markers. First, this review introduces the background and fundamentals of the spectroscopies underlying the new methodologies, namely infrared and Raman spectroscopy. Then, results are presented in the context of spectral histopathology of tissues for detection of metastases in lymph nodes, squamous cell carcinoma, adenocarcinomas, brain tumors and brain metastases. Results from spectral cytopathology of cells are discussed for screening of oral and cervical mucosa, and circulating tumor cells. It is concluded that infrared and Raman spectroscopy can complement histopathology and reveal information that is available in classical methods only by costly and time-consuming steps such as immunohistochemistry, polymerase chain reaction or gene arrays. Due to the inherent sensitivity toward changes in the bio-molecular composition of different cell and tissue types, vibrational spectroscopy can even provide information that is in some cases superior to that of any one of the conventional techniques.


Assuntos
Patologia Molecular/métodos , Espectrofotometria Infravermelho/métodos , Análise Espectral Raman/métodos , Animais , Humanos , Metástase Linfática , Neoplasias/diagnóstico , Neoplasias/patologia
10.
Analyst ; 138(14): 3975-82, 2013 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-23560275

RESUMO

This paper presents a short review on the improvements in data processing for spectral cytopathology, the diagnostic method developed for large scale diagnostic analysis of spectral data of individual dried and fixed cells. This review is followed by the analysis of the confounding effects introduced by utilizing reflecting "low-emissivity" (low-e) slides as sample substrates in infrared micro-spectroscopy of biological samples such as individual dried cells or tissue sections. The artifact introduced by these substrates, referred to as the "standing electromagnetic wave" artifact, indeed, distorts the spectra noticeably, as postulated recently by several research groups. An analysis of the standing wave effect reveals that careful data pre-processing can reduce the spurious effects to a level where they are not creating a major problem for spectral cytopathology and spectral histopathology.


Assuntos
Diagnóstico por Imagem/métodos , Neoplasias Bucais/diagnóstico , Lesões Pré-Cancerosas/diagnóstico , Espectrofotometria Infravermelho/métodos , Língua/citologia , Algoritmos , Estudos de Casos e Controles , Humanos
11.
J Biophotonics ; 6(1): 101-9, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23192957

RESUMO

The first study interpreting B-lymphocyte activation in normal lymph nodes using vibrational micro-spectral imaging is reported. Lymphocyte activation indicates the presence and response against a pathogen, regardless of the inciting pathogen's etiology, whether a benign, reactive or malignant process. Understanding the biochemical makeup of lymphocyte activation during early stages of disease and immune response may offer significant aid in determining a tumor's origin without the presence of malignant metastatic cells but within lymph nodes that are reactive and displaying regions of hyperplasia. Infrared and Raman data scrutinized via unsupervised multivariate methods may provide a physical and reproducible method to determine the biochemical components and variances therein of activated lymph nodes with distinguishing characteristics depending on the malignancy present in the region or elsewhere in the body. The results reported here provide a proof-of-concept study that reveal a potential to screen lymph nodes for disease without the presence of metastatic cells.


Assuntos
Adenocarcinoma/patologia , Linfócitos B/patologia , Neoplasias do Colo/patologia , Espectrofotometria/métodos , Algoritmos , Análise por Conglomerados , Neoplasias Esofágicas/patologia , Humanos , Linfonodos/patologia , Ativação Linfocitária , Análise Multivariada , Metástase Neoplásica , Análise de Componente Principal , Espectrofotometria Infravermelho/métodos , Neoplasias Gástricas/patologia
12.
Anal Chem ; 84(19): 8265-71, 2012 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-22935013

RESUMO

Spectral cytopathology (SCP) is a robust and reproducible diagnostic technique that employs infrared spectroscopy and multivariate statistical methods, such as principal component analysis to interrogate unstained cellular samples and discriminate changes on the biochemical level. In the past decade, SCP has taken considerable strides in its application for disease diagnosis. Cultured cell lines have proven to be useful model systems to provide detailed biological information to this field; however, the effects of sample fixation and storage of cultured cells are still not entirely understood in SCP. Conventional cytopathology utilizes fixation and staining methods that have been established and widely accepted for nearly a century and are focused on maintaining the morphology of a cell. Conversely, SCP practices must implement fixation protocols that preserve the sample's biochemical composition and maintain its spectral integrity so not to introduce spectral changes that may mask variance significant to disease. It is not only necessary to evaluate the effects on fixed exfoliated cells but also fixed cultured cells because although they are similar systems, they exhibit distinct differences. We report efforts to study the effects of fixation methodologies commonly used in traditional cytopathology and SCP including both fixed and unfixed routines applied to cultured HeLa cells, an adherent cervical cancer cell line. Data suggest parallel results to findings in Part 1 of this series for exfoliated cells, where the exposure time in fixative and duration of sample storage via desiccation contribute to minor spectral changes only. The results presented here reinforce observations from Part 1 indicating that changes induced by disease are much greater than changes observed as a result of alternate fixation methodologies. Principal component analysis of HeLa cells fixed via the same conditions and protocols as exfoliated cells (Part 1) yield nearly identical results. More importantly, the overall conclusion is that it is necessary that all samples subjected to comparative analysis should be prepared identically because although changes are minute, they are present.


Assuntos
Análise de Componente Principal , Fixação de Tecidos , Células HeLa , Humanos , Espectrofotometria Infravermelho , Células Tumorais Cultivadas
13.
Analyst ; 137(13): 2958-64, 2012 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-22377958

RESUMO

We have optimized an imaging methodology capable of monitoring individual live HeLa cells using non-synchrotron FTIR in an aqueous environment. This methodology, in combination with MATLAB based pre-processing techniques, allows fast and efficient collection of data with high signal-to-noise ratio in comparison with previous methods using point mode data collection, which required manual operation and more collection time. Also, presented are early results that illustrate interpretable spectral differences from live cells treated with chemotherapeutic drugs, demonstrating the potential of this methodology to develop more desirable modes of treatment for patients in their diagnoses and treatments for disease.


Assuntos
Análise de Componente Principal , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Células HeLa , Humanos
14.
Anal Chem ; 84(3): 1259-66, 2012 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-22103764

RESUMO

Spectral cytopathology (SCP) is a novel approach for disease diagnosis that utilizes infrared spectroscopy to interrogate the biochemical components of cellular samples and multivariate statistical methods, such as principal component analysis, to analyze and diagnose spectra. SCP has taken vast strides in its application for disease diagnosis over the past decade; however, fixation-induced changes and sample handling methods are still not systematically understood. Conversely, fixation and staining methods in conventional cytopathology, typically involving protocols to maintain the morphology of cells, have been documented and widely accepted for nearly a century. For SCP, fixation procedures must preserve the biochemical composition of samples so that spectral changes significant to disease diagnosis are not masked. We report efforts to study the effects of fixation protocols commonly used in traditional cytopathology and SCP, including fixed and unfixed methods applied to exfoliated oral (buccal) mucosa cells. Data suggest that the length of time in fixative and duration of sample storage via desiccation contribute to minor spectral changes where spectra are nearly superimposable. These findings illustrate that changes influenced by fixation are negligible in comparison to changes induced by disease.


Assuntos
Mucosa Bucal/patologia , Fixação de Tecidos , Fosfatos de Cálcio/química , Humanos , Doenças da Boca/diagnóstico , Doenças da Boca/patologia , Análise de Componente Principal , Fatores de Tempo
15.
J Biophotonics ; 3(8-9): 588-96, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20449833

RESUMO

In this paper we describe the advantages of collecting infrared microspectral data in imaging mode opposed to point mode. Imaging data are processed using the PapMap algorithm, which co-adds pixel spectra that have been scrutinized for R-Mie scattering effects as well as other constraints. The signal-to-noise quality of PapMap spectra will be compared to point spectra for oral mucosa cells deposited onto low-e slides. Also the effects of software atmospheric correction will be discussed. Combined with the PapMap algorithm, data collection in imaging mode proves to be a superior method for spectral cytopathology.


Assuntos
Células Cultivadas/química , Células Cultivadas/classificação , Microscopia/métodos , Espectrofotometria Infravermelho/métodos , Animais , Humanos
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