THIAGO MARTINI PEREIRA
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- Rapid identification of breast cancer in different stages using micro-FTIR and supervised machine learning methods2024 - GERMANO, GLEICE; VALLE, MATHEUS D.; PERES, DANIELLA L.P.M. de O.; SILVA, DANIELA de F.T. da; PEREIRA, THIAGO M.; ZEZELL, DENISE M.According to the World Health Organization, breast cancer is the second most common cancer in the world; 11.5% of the total cases of cancer in both genders and 15.4% of deaths in females are reported. Accurate determination of the intrinsic subtype and disease stage of breast cancer will help in the adoption of optimal treatment strategies, thus improving overall outcomes. The aim of the present work, therefore, is to apply micro-FTIR spectroscopy combined with different supervised machine learning methods to classify various types and stages of breast cancer and to identify the chemometric areas that best distinguish between them. In the work reported here, PCA-LDA and PLS-DA models were carried out in the raw data in the fingerprint region (1800–900 cm−1) and the region characteristic for proteins (1750–1400 cm−1). Therefore, the analysis of these results reveals significant differences in the amide I and amide II regions, thus proving that both PCA-LDA and PLS-DA are useful frameworks for performing discrimination analyses.
Artigo IPEN-doc 27546 Evaluating biochemical differences in thyroglobulin from normal and goiter tissues by infrared spectral imaging2020 - PEREIRA, THIAGO M.; DIEM, MAX; BACHMANN, LUCIANO; BIRD, BENJAMIN; MILJKOVIC, MILOS; ZEZELL, DENISE M.Thyroglobulin is a glycoiodoprotein that is produced by thyroid follicular cells; it is stored in follicles in structures known as colloids. The main function of this protein is to stock the hormones triiodothyronine (T3) and thyroxine (T4) until the body requires them. This study aims to demonstrate that infrared spectral imaging with appropriate multivariate analysis can reveal biochemical changes in this glycoprotein. The results achieved herein point out biochemical differences in the colloid samples obtained from normal and goiter patients including glycosylation and changes in the secondary conformational structure. We have presented the first spectral histopathology-based method to detect biochemical differences in thyroid colloids, such as TG iodination, glycosylation, and changes in the secondary structure in normal and goiter patients. The observed changes in the colloids were mainly due to the alterations in amide I and amide II (secondary conformation of proteins) and there is a correlation with different glycosylation between normal and goiter tissues.Artigo IPEN-doc 27026 Caracterização por espectroscopia no infravermelho de colóides tireoidianos sadios e hiperplásicos2014 - PEREIRA, T.M.; DIEM, M.; BIRD, B.; MILJKOVIC, M.; ANA, P.A.; BACHMANN, L.; ZEZELL, D.M.O presente trabalho mostra a caracterização da Tiroglobulina contidos nos colóides tireoidianos por espectroscopia no infravermelho. A produção da tiroglobulina é alterada em pacientes com Bócio Nodular. Assim, as informações bioquímicas desta glicoiodoproteina podem ser utilizada como indicador desta disfunção. Os resultados utilizando espectroscopia no infravermelho revela diferenças bioquímicas nas conformação da proteína, hormônios e carboidratos.Artigo IPEN-doc 18215 Influence of fixation products used in the histological processing in the FTIR Spectra of lung cells2012 - PEREIRA, THIAGO M.; DAGLI, MARIA L.Z.; MENNECIER, GREGORY; ZEZELL, DENISE M.