MOISES OLIVEIRA DOS SANTOS

MOISES OLIVEIRA DOS SANTOS

Página do item completo

Resultados de Busca

Agora exibindo 1 - 9 de 9

Evaluation of calcified mitral valves after Er,Cr:YSGG irradiation using Optical Coherence Tomography
2022 - DEL-VALLE, MATHEUS; CARVALHO, MARCELO; SANTOS, MOISES; PINTO, NATHALI; JATENE, FABIO; POMERANTZEFF, PABLO; BRANDAO, CARLOS; ZEZELL, DENISE
Mitral valve is responsible to control the left atrium-ventricle blood flux. Mitral stenosis is a disease that occurs in consequence of calcification and fibrosis on the cuspids of the valve. Diagnosis can be performed using echocardiography.Many treatments are possible, and one of them is commissurotomy (surgical approach).High intensity laser irradiation may be a new strategy for this surgical technique[1], and the optical coherence tomography (OCT) may contribute to the valve evaluation[2], asit provides higherspatialresolutionin exchange of lower penetrationthan ultrasonography. In this way, the aim of this study is to evaluate laser irradiation effectsincalcified mitral valvesusing OCTand digital processing.To that, it was conducted an ex-vivostudywith four human mitral valvessamples,obtained from valve replacement surgeries in the Heart Institute.The samples were splitin four groups: scalpel cut, laser cut, scalpel debridement and laser debridement.Cutting and debridement procedures were performed in calcified regions of the valves, usinga disposable scalpelbladeand anEr,Cr:YSGG laser(Waterlase; Biolase Inc., CA, USA), emitting at 2780 nm. The laser parameters were set at power = 1.6W, frequency = 20 Hz, energy density = 28.3J/cm2,pulse duration = 700 μs, 15% of water and 15% of air.The imaging was performed using a spectraldomain OCT system(Callisto110C1;ThorLabs Inc., NJ, USA).It was acquired10 B-scans per sample, 5 inprocedures regions and 5 in sound regions. The Optical Attenuation Coefficient (OAC) was calculated by comparing a beer-lambert like equation to exponential fittings of the A-scans[3].The distribution and normality of variances were tested using Shapiro-Wilk test,and statistical comparison was performed using one-way ANOVA and Tukey’s post hoc. All tests considered a level of significance of 5%.The FigureAshows a representative B-scan of a visibly calcified region, where a pattern of higher intensities can be observed.Thispattern is related tomorphological and optical changes, mainly a refractive index change, due to calcium presence in the valve tissue.This B-scan was acquired only to understand the calcified tissue aspect, as the procedures regions does notpresent visibly largecalcium stones.The Figure Bshowsthe statisticalanalysis, where the sound OAC values, as a mean of all sound regions, presented a significant statistical difference in comparison to scalpel groups, while no difference waspresentedin relation to laser groups. Higher OAC values are related to anaugmentation of the light backscatteringdue to calcium refractive index, leading to a change of lightpropagation in tissue-calcium interfaces.This finding indicates thatthe laser procedures promoted a better removal of calcified tissue than the scalpelmethods, which can be related to tissue-ablation interaction.Furthermore, the statistical difference between scalpel cut group and both laser groups suggests that the scalpel needs more wear interaction with the tissue, such as in the debridement procedure, being unable to significatively remove the calcification in a single cut.This study points the Er,Cr:YSGG and the OCT as potential techniques for the calcified tissue removal and evaluation,respectively, duringmitral valvessurgeries, although further studieswith higher sample numbermust be performed.
FTIR imaging on glass substrates evaluation of histological skin burn injuries specimens treated by femtosecond laser pulses
2022 - ZEZELL, DENISE; CASTRO, PEDRO; DEL-VALLE, MATHEUS; CAMILLO-SILVA, CARLOS; SAMAD, RICARDO; DE ROSSI, WAGNER; SANTOS, MOISES
Burn injuries continue to be one of the leading causes of unintentional death and injury in low- and middle-income countries [1]. Burns are considered an important public health problem, because in addition to physical problems that can lead the patient to death, they cause psychological and social damage. An estimated 180,000 deaths every year are caused by burns [2]. The use of infrared (IR) spectroscopy for studying biological specimens is nowadays a wide and active area of research. The IR microspectroscopy has proved to be an ideal tool for investigating the biochemical composition of biological samples at the microscopic scale, as well as its fast, sensitive, and label-free nature [3]. IR image spectral histopathology has shown great promise as an important diagnostic tool, with the potential to complement current pathological methods, reducing subjectivity in biopsy samples analysis. However, the use of IR transmissive substrates which are both fragile and prohibitively very expensive, hinder the clinical translation. The goal of this study is to evaluate the potential of discriminating healing process, in burned skin specimens treated with ultrashort pulses laser 3 days after the burn. This study is considering a previous paper [4], in which it analyzed only micro-ATR-FTIR spectra of a frozen sample point. The specimens were obtained from third degree burn wound. The wounds treatment were performed three days after the burn, and the animals were sacrificed 3 and 14 days post-treatment. Using coverslipped H&E stained tissue on glass from previous histopathological analysis and applying the analytical techniques PCA and K-means on N−H, O−H, and C−H stretching regions occurring at 2500−3800 cm−1 (high wavenumber region), were possible to discriminate burned epidermal and dermal regions from irradiated in same regions on sample. In the figures is shown the average spectrum at (a) day 3 and (b) day 14. , in both there were increase of burned+laser treated bands. The great potential of this study was to analyse coverslipped H&E stained tissue on glass, without compromising the histopathologist practices and contribute for clinical translation.
Breast cancer subtype classification using a one-dimensional convolutional neural network in hyperspectral images
2022 - DEL-VALLE, MATHEUS; SANTOS, MOISES O. dos; BERNARDES, EMERSON S.; ZEZELL, DENISE M.
FTIR spectroscopy imaging in addition to deep learning is a potential tool for breast cancer subtype classification, where accuracies higher than 86% can be achieved to predict among all subtypes.
The impact of scan number and its preprocessing in micro-FTIR imaging when applying machine learning for breast cancer subtypes classification
2021 - DEL-VALLE, MATHEUS; SANTOS, MOISES O. dos; SANTOS, SOFIA N. dos; CASTRO, PEDRO A.A. de; BERNARDES, EMERSON S.; ZEZELL, DENISE M.
The breast cancer molecular subtype is an important classification to outline the prognostic. Gold-standard assessing using immunohistochemistry adds subjectivity due to interlaboratory and interobserver variations. In order to increase the diagnosis confidence, other techniques need to be examined, where the FTIR spectroscopy imaging allied with machine learning techniques may provide additional and quantitative information regarding the molecular composition. However, the impact of co-added scans acquisition parameter into machine learning classifications still needs better evaluation. In this study, FTIR images of Luminal B and HER2 subtypes were acquired varying the scan number and preprocessing techniques. It was demonstrated a spectral quality improvement when the scan number was increased, decreasing the standard deviation and outliers. Six machine learning models were used to classify the subtypes: Linear Discriminant Analysis, Partial Least Squares Discriminant Analysis, K-Nearest Neighbors, Support Vector Machine, Random Forest and Extreme Gradient Boosting. Best mean accuracy of 0.995 was achieved by Extreme Gradient Boosting model. It was found that all models achieved similar high accuracies with groups b256_064 (256 background and 064 scans), b256_128 and b128_128. Besides assessing the performance of different models, the b256_064 was established as the optimal group due to the minimum acquisition time. Therefore, this work indicates b256_064 for breast cancer subtype classification and also as a basis for other studies using machine learning for cancer evaluation.
Breast cancer estrogen and progesterone receptors evaluation using FTlR spectroscopy imaging
2020 - DEL-VALLE, M.; SANTOS, M.O.; SANTOS, S.N. dos; BERNARDES, E.S.; ZEZELL, D.M.
INTRODUCTION. Breast cancer is the second leading cause of cancer death in woman worldwide with an incidence of 2.09 million and 627 thousand deaths in 2018. Histopathology is the gold standard method for cancer diagnosis and identification of therapeutic targets, however it still presents interpretation difficulties, especially when comparing different cancer subtypes. OBJETICVE: The aim of this study was to evaluate Fourier transform infrared (FTIR) spectroscopy in the diagnose and differentiation of molecular differences between two different breast cancer subtypes: positive and negative for estrogen (ER) and progesterone (PR) receptors. METHODS: Two human breast cell lines, BT474 (ER and PR positive) and SKBR3 (ER and PR negative), were inoculated in Balb/c nude mice. Tumors were collected when reached 0.5 cm3, processed by formalin fixation and paraffin embedding. 5μm thick tissue cuts were fixed in low-e slides (MirrIR, Kevley Technologies). Spectral images were performed in a micro-FTIR (Cary 660, Agilent Technologies) with 32 x 32 FPA of 5.5 μm pixel size. Scattering correction (RMieS-EMSC) was performed using MATLAB and remaining processing using Python. Groups differentiation were evaluated by PCA from 1350 to 1000 cm-1 second derivatives. RESULTS AND DISCUSSION: Groups were split in two clusters, separated by PC-1 with a 99 % accuracy in both groups and 45 % of explained variance. The absorptions in the selected region for the PCA were mainly related to DNA, RNA and protein content. The main contribution was presented by the 1238 cm-1 peak, which was correlated with nucleic acids symmetrical stretching. Hyperspectral image built from this peak presented a spatial correlation with the microscope white light imaging, indicating that possible region for histopathological correlation might be present. CONCLUSAO: Our pilot study shows that FTIR spectroscopy imaging can distinguish ER/PR positive from negative breast cancer subtypes.
Machine Learning methods for micro-FTIR imaging classification of human skin tumors
2021 - DEL VALLE, MATHEUS; STANCARI, KLEBER; CASTRO, PEDRO A.A. de; SANTOS, MOISES O. dos; ZEZELL, DENISE M.
This review presents some methods applied to micro-FTIR imaging for classification of human skin tumors. It is a collection of the pre-processing pipeline and machine learning classification models. The aim of this review is to update and summaiize the current methods which an applied in our skin tumor research.
Evaluation of machine learning models for the classification of breast cancer hormone receptors using micro-FTIR images
2021 - VALLE, MATHEUS del; SANTOS, MOISES O. dos; SANTOS, SOFIA N. dos; BERNARDES, EMERSON S.; ZEZELL, DENISE M.
The breast cancer is the most incident cancer in women. Evaluation of hormone receptors expression plays an important role to outline treatment strategies. FTIR spectroscopy imaging may be employed as an additional technique, providing extra information to help physicians. In this work, estrogen and progesterone receptors expression were evaluated using tumors biopsies from human cell lines inoculated in mice. FTIR images were collect from histological sections, and six machine learning models were applied and assessed. Xtreme gradient boost and Linear Discriminant Analysis presented the best accuracies results, indicating to be potential models for breast cancer classification tasks.
Human dental enamel evaluation after radiotherapy simulation and laminates debonding with Er,Cr:YSGG using SEM and EDS
2019 - RABELO, THAIS F.; ZAMATARO, CLAUDIA B.; KUCHAR, NIELSEN G.; ZANINI, NATHALIA; JUVINO, AMANDA C.; DEL-VALLE, MATHEUS; CASTRO, PEDRO A.A.; SANTOS, MOISES O.; ZEZELL, DENISE M.
The pursuit of perfection makes younger people undergo aesthetic procedures without formal indication. However, young patients may be susceptible to a disease such as head and neck cancer which treatment can compromise the adhesion of these indirect mate-rials. Here, we present an analyze, of the gamma radiation effects on crystallographic morphology of human dental enamel after laminate veneer debonding with Er,Cr:YSGG laser. Thus, human dental enamel samples were prepared and randomized into 2 groups (n=10): Laser Irradiation (L) and Gamma + Laser Irradiation (GL) group. Scanning elec-tron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were performed before bonding and after debonding using Er,Cr:YSGG. Only Gamma + Laser Irradia-tion group received a cumulative dose of 70 Gy gamma radiation used in head and neck cancer radiotherapy. SEM images showed that both GL and L groups presented altered morphology. EDS showed an decrease in Ca and P intensities after laser debonding of laminates veneers in both group. Therefore, a proper laser facet removal protocol should be established for healthy patients and patients who have been exposed to radiotherapy for head and neck cancer.
Multimodal evaluation of ultra-short laser pulses treatment for skin burn injuries
2017 - SANTOS, MOISES O. dos; LATRIVE, ANNE; CASTRO, PEDRO A.A. de; ROSSI, WAGNER de; ZORN, TELMA M.T.; SAMAD, RICARDO E.; FREITAS, ANDERSON Z.; CESAR, CARLOS L.; VIEIRA JUNIOR, NILSON D.; ZEZELL, DENISE M.
Thousands of people die every year from burn injuries. The aim of this study is to evaluate the feasibility of high intensity femtosecond lasers as an auxiliary treatment of skin burns. We used an in vivo animal model and monitored the healing process using 4 different imaging modalities: histology, Optical Coherence Tomography (OCT), Second Harmonic Generation (SHG), and Fourier Transform Infrared (FTIR) spectroscopy. 3 dorsal areas of 20 anesthetized Wistar rats were burned by water vapor exposure and subsequently treated either by classical surgical debridement, by laser ablation, or left without treatment. Skin burn tissues were noninvasively characterized by OCT images and biopsied for further histopathology analysis, SHG imaging and FTIR spectroscopy at 3, 5, 7 and 14 days after burn. The laser protocol was found as efficient as the classical treatment for promoting the healing process. The study concludes to the validation of femtosecond ultra-short pulses laser treatment for skinburns, with the advantage of minimizing operatory trauma.