LUCAS RAMOS DE PRETTO

LUCAS RAMOS DE PRETTO

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Relationship between nonperfusion area from widefeld optical coherence tomography angiography and macular vascular parameters in diabetic retinopathy
2023 - KONNO, AMI; ISHIBAZAWA, AKIHIRO; PRETTO, LUCAS de; SHIMOUCHI, AKITO; OMAE, TSUNEAKI; SONG, YOUNG‑SEOK
Purpose To evaluate the relationship between the nonperfusion area (NPA) from widefield optical coherence tomography angiography (OCTA) and macular vascular parameters in diabetic retinopathy (DR). Methods In total, 51 eyes from 51 patients with proliferative DR (PDR) or moderate/severe non-PDR were included. Widefield OCTA using the Zeiss Plex Elite 9000 was performed. A semi-automatic algorithm calculated the percentages of the NPA within the total image. Macular OCTA (3 × 3 mm and 6 × 6 mm area) was scanned using the RTVue-XR Avanti. Vessel density (VD) was automatically separated into the superficial (SCP) and deep capillary plexus (DCP), and foveal avascular zone (FAZ) measurements were computed according to the parafoveal (1–3 mm) and perifoveal (3–6 mm) regions. Results A negative correlation was found between the average VD of the SCP and DCP obtained 3 × 3 mm and 6 × 6 mm area and the NPA. Multiple regression analysis revealed that the temporal–perifoveal region most negatively correlated with the NPA (r = − 0.55, p < 0.0001). No correlation was found between FAZ measurements and DR severity (area, p = 0.07; perimeter, p = 0.13). Conclusion Diabetic macular nonperfusion was significantly associated with the NPA from widefield OCTA. In particular, the temporal–perifoveal DCP disorder may be a sensitive indicator of wide NPA.
Noninvasive red Laser intervention before radiotherapy of triple-negative breast cancer in a murine model
2023 - SILVA, CAMILA R.; PEREIRA, SAULO T.; SILVA, DANIELA F.T.; PRETTO, LUCAS R. de; FREITAS, ANDERSON Z.; ZEITUNI, CARLOS A.; ROSTELATO, MARIA E.C.M.; RIBEIRO, MARTHA S.
In proton beam treatments, the superposition of several weighted Bragg curves with different incident energies is required to homogeneously irradiate a large tumor volume, creating a spread-out Bragg peak (SOBP). This paper confirms on the suitability of two different methods to create SOBPs – Bortfeld/Jette's and MCMC (Monte Carlo calculations and Matrix Computations), using Monte Carlo simulations performed with TOPAS and MCNP6.1. To generate the SOBPs, algorithms were developed for implementation of the two methods, which enabled to find the weights for thirty variations of SOBPs, categorized according to their width and maximum depths. The MCMC method used weight optimization in designing SOBPs to avoid negative values. In contrast, the Bortfeld/Jette's method yielded the SOBPs according to the variation of a power-law parameter ( ) introduced by the range-energy relationship. Optimal values of , from MCNP and TOPAS, were selected in order to retrieve SOBPs with the best smoothness and then related to those obtained from the literature. In comparing both methods and codes, dose homogeneity parameters ( ) were used to examine the SOBP flatness and gamma analyses were employed to assess the dose deposition along its full extension. The results showed that the SOBPs designed using the MCMC method had better values and computational performance for both codes when compared to the Bortfeld/Jette's method. The gamma analyses highlighted significant differences between the entrance doses comparing the two different methods, for SOBPs with intermediate and high depths and small width. This evaluation was not possible with the values alone, which stresses the relevance of a broad analysis to avoid unintended doses in healthy tissues.
Optical coherence tomography (OCT) for the analysis of zirconia crystalline phase transformation
2023 - ARATA FOUND, ANELYSE; PRETTO, L.R. de; USSUI, V.; LIMA, N.B. de; SOUZA, G.M. de; MACHADO, J.P.B.; TANGO, R.N.; FREITAS, A.Z.; LAZAR, D.R.R.
This study aimed to validate the Optical coherence tomography (OCT) for the analysis of the transformed zone of two dental zirconia-based materials after hydrothermal ageing and correlate the values with biaxial flexural strength. Kinetics of tetragonal to monoclinic phase transformation (t→m) was calculated. X-ray diffraction (XRD) results showed a sigmoidal transformation rate over time due to the limited X-ray maximum penetration depth. Scanning electron microscope (SEM) and OCT showed a linear relationship between the thickness of the transformed layer and the ageing time. The apparent activation energy was 104.5 kJ/mol and 106.7 kJ/mol (SEM) and 106 kJ/mol and 99.4 kJ/mol (OCT) for the infrastructure and monolithic dental zirconia, respectively. Mechanical strength decreased after 150 h. of ageing at 150 ◦C for both materials showing a correlation with the depth of the transformed zone observed by OCT. Therefore, both monoclinic phase percentage and the depth of the transformed layer are critical concerning zirconia mechanical properties upon hydrothermal ageing. OCT is a non-destructive, fast, innovative, and accurate method for the analysis of zirconia’s t→m phase transformation depth kinetics after hydrothermal ageing.
Photobiomodulation therapy as a radiosensitizer for triple-negative breast cancer
2022 - SILVA, CAMILA R.; PEREIRA, SAULO de T.; PRETTO, LUCAS R. de; FREITAS, ANDERSON Z. de; RIBEIRO, MARTHA S.
INTRODUCTION: Radiotherapy (RT) is an essential cancer treatment and is estimated that approximately 52% of oncological patients will be submitted to this technique once. However, some tumors, such as triple-negative breast cancer (TNBC), present radioresistance, demanding high doses of ionizing radiation (IR) and a prolonged period of treatment, which contributes to secondary malignancies due to deposition of dose in organs at risk and several side effects. Moreover, this subtype of cancer shows a high incidence of metastasis and decreases the survival expectancy of the patient. Thus, the search for new agents that can act as a radiosensitizer to improve the RT effects has been growing. Conversely, photobiomodulation therapy (PBM), which is a promising therapy with increasing adhesion in clinical practice, has been used to mitigate the adverse effects of RT. Indeed, recent studies have associated PBM with RT to combat cancer. OBJECTIVES: In this study, we used TNBC-bearing mice as a radioresistant cancer model to verify if PBM could act as a radiosensitizer MATERIALS AND METHODS: PBM was applied in two different protocols before the RT with a high dose (60 Gy fractioned in 4 sessions). We evaluated the tumor volume progression, animal clinical evolution, lung metastases by optical coherence tomography, and animal survival DISCUSSION AND RESULTS: Our data indicate that PBM before each RT session arrested the tumor volume, improved the clinical signals of the animals, reduced the nodules in the lung, and extended animal survival. CONCLUSION: In the light of the knowledge gained, our data indicate that PBM could act as a radiosensitizer.
Long-term functioning status of COVID-19 survivors
2022 - BATTISTELLA, LINAMARA R.; IMAMURA, MARTA; DE PRETTO, LUCAS R.; VAN CAUWENBERGH, SIMON K.H.A.A.; RAMOS, VINICIUS D.; UCHIYAMA, SABRINA S.T.; MATHEUS, DENISE; KUHN, FLAVIA; OLIVEIRA, ANA A.A. de; NAVES, GABRIELLA S.; MIRISOLA, ALINE R.; RIBEIRO, FERNANDO de Q.; SUGAWARA, ANDRE T.; CANTARINO, MAURICIO; CAVALCA, RAFAEL A.S.A.; PAGANO, VANESSA; MARQUES, MELINA V.; SILVA, ELIZABETH M. da; GOMES, ALESSANDRA P.; FREGNI, FELIPE
Objectives The study investigated the long-term functional status of hospitalised COVID-19 survivors to explore and document their functional situation. Design This prospective observational study assessed 801 COVID-19 survivors at 3–11 months after hospital discharge. It analyses participants' sociodemographic background, COVID-19 clinical manifestations, and clinical and functional evaluations. Setting Tertiary-level university hospital in São Paulo, Brazil. Participants Study participants are COVID-19 survivors admitted to hospital care for at least 24 hours to treat acute SARS-CoV-2 infection. Outcome measures Epworth Sleepiness Scale, EuroQoL-5 Dimensions-5 Levels, Functional Assessment of Chronic Illness Therapy–Fatigue, Functional Independence Measure, Functional Oral Intake Scale, Handgrip Strength, Insomnia Severity Index, Medical Research Council (MRC) Dyspnea Scale, MRC sum score, Modified Borg Dyspnea Scale, pain Visual Analogue Scale, Post-COVID-19 Functional Status, Timed Up and Go, WHO Disability Assessment Schedule 2.0, 1-Minute Sit to Stand Test. Results Many participants required invasive mechanical ventilation (41.57%, 333 of 801). Mean age was 55.35±14.58 years. With a mean of 6.56 (SD: 1.58; 95% CI: 6.45 to 6.67) months after hospital discharge, 70.86% (567 of 800) reported limited daily activities, which were severe in 5.62% (45 of 800). They also reported pain and discomfort (64.50%, 516 of 800), breathlessness (64.66%, 514 of 795), and anxiety and depression (57.27%, 457 of 798). Daytime sleepiness and insomnia evaluations showed subthreshold results. Most (92.85%, 727 of 783) participants reported unrestricted oral intake. Data indicated no generalised fatigue (mean score: 39.18, SD: 9.77; 95% CI: 38.50 to 39.86). Assessments showed poor handgrip strength (52.20%, 379 of 726) and abnormal Timed Up and Go results (mean 13.07 s, SD: 6.49). The invasive mechanical ventilation group seemed to have a better handgrip strength however. We found no clear trends of change in their functional status during months passed since hospital discharge. Conclusions Muscle weakness, pain, anxiety, depression, breathlessness, reduced mobility, insomnia and daytime sleepiness were the most prevalent long-term conditions identified among previously hospitalised COVID-19 survivors.
Rehabilitation of patients after COVID-19 recovery
2021 - IMAMURA, MARTA; MIRISOLA, ALINE R.; RIBEIRO, FERNANDO de Q.; DE PRETTO, LUCAS R.; ALFIERI, FABIO M.; DELGADO, VINICIUS R.; BATTISTELLA, LINAMARA R.
OBJECTIVES: As patients recovering from the novel coronavirus disease 2019 (COVID-19) present with physical, respiratory, cognitive, nutritional, and swallowing-related impairments and mental health complications, their rehabilitation needs are complex. This study aimed to describe the demographic, clinical, and functional status after the discharge of COVID-19 survivors who underwent intensive multidisciplinary inpatient rehabilitation at the Physical and Rehabilitation Medicine Institute of the University of Sao Paulo Medical School General Hospital and Lucy Montoro Rehabilitation Institute. We determined the most important factors related to the length of inpatient rehabilitation treatment and present the functional outcomes. METHODS: This was a retrospective study based on electronic medical records. In addition to the severity of COVID-19 and length of hospital stay for the management of COVID-19 and comorbidities, we collected sociodemographic data including age, sex, height, and weight. Functional assessments were performed using the Functional Independence Measure (FIM); Short Physical Performance Battery; Montreal Cognitive Assessment; Depression, Anxiety and Stress Scale; Revised Impact of Events Scale; bioelectrical impedance; Functional Oral Intake Scale; oropharyngeal dysphagia classification; and nutritional assessment. RESULTS: There was a significant improvement in FIM before and after inpatient rehabilitation treatment (p<0.0001). Muscle strength and walking capacity were significantly improved (p<0.01). The most important factors related to the length of inpatient rehabilitation treatment were improvement in FIM scores (Spearman’s r=0.71) and gain in lean mass (Spearman’s r=0.79). CONCLUSIONS: Rehabilitation of patients after COVID-19 recovery improves their functional status and should be considered in the post-acute phase for selected patients with COVID-19.
Laser speckle imaging for osteoporosis evaluation
2020 - AMARAL, MARCELLO M.; DEL-VALLE, MATHEUS; RAELE, MARCUS P.; PRETTO, LUCAS R. de
Osteoporosis is a common disease characterized by the reduction on Bone Mineral Density (BMD), leading to weakening of bone structure, Chronic pain, deformities and loss of quality of life. In addition to the clinical evaluation, dual-energy X-ray absorptiometry is one of the main techniques to diagnose it. However, this technique uses ionizing radiation to assess the bone structure and therefore cannot be used very often by patients, due to radiological safety reasons. On the other hand, optical techniques are known for its safe use, due to non-ionizing radiation, however, optical techniques do not easily allows the analysis of bone tissue. This limitation could be circumvented in the oral cavity area. In this work we used the Laser Speckle Imaging (LSI) technique to evaluate maxilla and mandible bones after demineralization prosses in an animal in vitro model. Osteoporosis lesions were simulated in sixteen mandible and twelve maxilla slabs using Ethylenediaminetetraacetic Acid (EDTA) 0.5 M for 0 (control) 7, 15 and 30 days. The roughness parameters Ra and Rq were analyzed with optical profilometry (ZeGage, Zygo, USA) to characterize the demineralization process. The LSI images were measured by custom experimental setup. A collimated laser beam at 635 nm and 1.3mW (Thorlabs CPS635R), expanded by a diverging lens (-75 mm), illuminates the sample. The scattered signal was imaged by a CCD camera (Thorlabs - DCC1645-HQ), an adapter (Thorlabs MVLCMC) and objective lens (Thorlabs/Navitar - MVL12X3Z) setting. A custom software was implemented to measure the speckle patches ratio and the speckle contrast ratio from speckle images obtained by a custom LSI setup. The speckle contrast ratio method only differentiate sound from osteoporotic tissue. The speckle patches ratio method presented a negative correlation with the roughness parameter, and consequently with the demineralization level. It was concluded that LSI is a promissory technique for assessment osteoporosis lesions on alveolar bone and, for that, the patches ratio is the best methodology for detecting and differentiating several degrees of demineralization.
Assessment of osteoporosis through laser speckle imaging
2020 - AMARAL, M.M.; DEL-VALLE, M.; RAELE, M.P.; PRETTO, L.R. de; ANA, P.A.
Nondestructive evaluation of fused filament fabrication 3D printed structures using optical coherence tomography
2020 - DE PRETTO, LUCAS R.; AMARAL, MARCELO M.; FREITAS, ANDERSON Z. de; RAELE, MARCUS P.
Purpose – The quality of components under fused filament fabrication (FFF) is related to the correct filament spacing and bonding of successively deposited layers and is evaluated mainly by scanning electron microscopy (SEM). However, it is a destructive technique and real-time evaluation is not possible. Optical coherence tomography (OCT), on the other hand, is an optical method that acquires cross-sectional images non-invasively and in real-time. Therefore, this paper aims to propose and validate the use of OCT as a non-destructive quality evaluation tool for FFF using Polylactic Acid (PLA) filaments. Design/methodology/approach – PLA three-dimensional (3D) printed samples were made in a variety of nozzle temperatures and mesh spacing. These samples were fractured in liquid nitrogen and inspected using SEM (as a gold standard) to evaluate dimensions and morphology, then the samples were evaluated by OCT in the same area, allowing the results confrontation. Findings – Our results indicate a good correlation between OCT and SEM for the dimensional assessment of layers. When the filament was extruded in lower temperatures, the OCT images presented sharply defined interfaces between layers, in contrary to higher nozzle temperatures, denoting better fusion between them. However, higher extruding temperatures are incurred in greater deviations from nominal dimensions of the mesh. Finally, we demonstrate the advantage of a full 3D tomographic reconstruction to inspect within a FFF sample, which enabled the inspection of “hidden” information, not visible on a single cross-sectional cut. Originality/value – This paper proposes OCT as a novel and nondestructive evaluation tool for FFF.
Desenvolvimento de técnicas diagnósticas quantitativas baseadas em decorrelação de speckle presente nos sinais de Tomografia de Coerência Óptica
2019 - PRETTO, LUCAS R. de
Segundo dados da Organização Mundial da Saúde (OMS), doenças crônicas não transmissíveis (DCNT), são uma das principais causas de morte no mundo, principalmente diabetes mellitus (DM). De particular importância para a DM, a manutenção de elevados níveis glicêmicos contribui de forma direta para o prejuízo das funções vasculares. Ainda, a DM impacta diretamente na qualidade de vida através de outros fatores associados à doença. Destaca-se a Retinopatia Diabética (RD), uma das principais causas de cegueira no mundo. A Tomografia por Coerência Óptica (OCT, do inglês, Optical Coherence Tomography) é uma modalidade de diagnóstico por imagem baseada em interferometria óptica que não utiliza radiação ionizante. Análise das flutuações de intensidade do sinal de OCT, devido ao padrão de ruído denominado speckle, possibilita análises angiográficas e de fluxo. Este estudo apresenta, então, o uso de OCT como ferramenta diagnóstica tanto para medir níveis glicêmicos no sangue de forma sem-contato, como para analisar in vivo a microvasculatura retinal. Desta maneira, novas técnicas diagnósticas para controle do nível glicêmico e para acompanhamento e estudo da retinopatia diabética são propostas. Os resultados de diferenciação da concentração de glicose no sangue obtidos, com métodos de análise espacial e temporal, são animadores e mostram boa sensibilidade do OCT para aplicações ex vivo, indicando uma potencial técnica de monitoramento glicêmico não-invasiva. Adicionalmente, as novas formas de análise microvascular da retina possibilitam um diagnóstico precoce da severidade da RD, o que possibilita melhor indicação do tratamento adequado a cada caso. Ainda, esta análise revela informações novas sobre a angiogênese da RD. É necessário, entretanto, um conhecimento adequado sobre as imagens adquiridas e métricas utilizadas, e um relatório sobre estes fatores foi desenvolvido. Com isto, esta tese demonstra a importância do desenvolvimento de técnicas de OCT para aplicações clínicas e para saúde dos pacientes com DM.