FTIR spectroscopy for diseases diagnosis
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2016
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ENCONTRO DE FISICA
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Resumo
Mid-infrared spectroscopy is a technique by which the chemical structure of an analyzed
material can be identified; it also allows the semi-quantitative analysis of the components of the
material. It has been already shown that Fourier transform infrared spectroscopy (FTIR) can be
used to evaluate the effects of high-intensity laser irradiation on dentin and enamel tissues,as
well as for the study of bone properties and several pathologies, such as lung, thyroid and skin
cancer.
The structural and biochemical changes associated with the development of enamel caries
and also with the interaction of laser irradiation with the enamel, suggest that vibrational
spectroscopy are promising techniques to differentiate sound and carious enamel, as well as
detect changes due to laser irradiation. Considering that there is no agreement in the literature
on the chemical changes promoted by the irradiation of Nd:YAG and Er,Cr:YSGG for
preventive purposes on enamel, our studies aimed to determine these changes by FTRaman and
FTIR spectroscopy and to investigate the influence of laser irradiation before or after the
application of topical fluoride on the development of caries in vitro.
Nonmelanoma skin cancers represent 95% of cutaneous neoplasms. Among them, squamous
cell carcinoma (SCC) is the more aggressive form and shows a pattern of possible metastatic
profile. In this work, we used Fourier transform infrared spectroscopy (FTIR) spectroscopy to
assess the biochemical changes in normal skin caused by squamous cell carcinoma induced by
multi-stage chemical carcinogenesis in mice. Changes in the absorption intensities and shifts
were observed in the vibrational modes associated to proteins, indicating changes in secondary
conformation in the neoplastic tissue. Hierarchical cluster analysis was performed to evaluate
the potential of the technique to differentiate the spectra of neoplastic and normal skin tissue, so
that the accuracy obtained
for this classification was 92%.
We develop a methodology to interpret hyperspectral imaging data and protein
conformational changes observed in nomal thyroid tissue. Raw image datasets
were imported into software written in-house in the MATLAB environment and processed to
yield pseudo-color images of the tissue sections. All spectra were vector normalized, noisefiltered,
and corrected for water-vapour contributions and scattering effects before being
subjected to Hierarchical Cluster Analysis (HCA) and correlated with histological structures
obtained from images of H&E-stained parallel tissue sections. We successfully identified a
protein structural heterogeneity that can be correlated with the spatially resolved amount of
iodine in the thyroglobulin structure of colloids and follicular cells.
The chemical carcinogens from tobacco are related to over 90% of lung cancers around the
world. The risk of death of this kind of cancer is high because the diagnosis usually is made
only in advanced stages. Therefore, to develop new diagnostic methods for detecting the lung
cancer in earlier is very important
stages. The second derivate of spectra indicates that there are displacement in 1646 cm-1 (amine
I) and 1255 cm-1 (DNA), allowing the possibility to differentiate the e10 lung normal cells from
e10 lung cells transformed by tobacco substances (NKK) with accuracy of 89,9%.
Como referenciar
ZEZELL, DENISE M. FTIR spectroscopy for diseases diagnosis. In: ENCONTRO DE FISICA, 03-07 de setembro, 2016, Natal, RN. Abstract... São Paulo: Sociedade Brasileira de Física, 2016. Disponível em: http://repositorio.ipen.br/handle/123456789/28169. Acesso em: 30 Dec 2025.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.