Search

Your search keyword '"Bigolin Á"' showing total 48 results
Start Over Author "Bigolin Á" Publication Year Range Last 50 years
48 results on '"Bigolin Á"'

1. Enhancing chest X-ray datasets with privacy-preserving large language models and multi-type annotations: a data-driven approach for improved classification

Author

Lanfredi, Ricardo Bigolin, Mukherjee, Pritam, and Summers, Ronald

Subjects
Electrical Engineering and Systems Science - Image and Video Processing, Computer Science - Computer Vision and Pattern Recognition
Abstract

In chest X-ray (CXR) image analysis, rule-based systems are usually employed to extract labels from reports for dataset releases. However, there is still room for improvement in label quality. These labelers typically output only presence labels, sometimes with binary uncertainty indicators, which limits their usefulness. Supervised deep learning models have also been developed for report labeling but lack adaptability, similar to rule-based systems. In this work, we present MAPLEZ (Medical report Annotations with Privacy-preserving Large language model using Expeditious Zero shot answers), a novel approach leveraging a locally executable Large Language Model (LLM) to extract and enhance findings labels on CXR reports. MAPLEZ extracts not only binary labels indicating the presence or absence of a finding but also the location, severity, and radiologists' uncertainty about the finding. Over eight abnormalities from five test sets, we show that our method can extract these annotations with an increase of 3.6 percentage points (pp) in macro F1 score for categorical presence annotations and more than 20 pp increase in F1 score for the location annotations over competing labelers. Additionally, using the combination of improved annotations and multi-type annotations in classification supervision, we demonstrate substantial advancements in model quality, with an increase of 1.1 pp in AUROC over models trained with annotations from the best alternative approach. We share code and annotations., Comment: Code and data: https://github.com/rsummers11/CADLab/tree/master/MAPLEZ_LLM_report_labeler/

Published
2024

2. Localization supervision of chest x-ray classifiers using label-specific eye-tracking annotation

Author

Lanfredi, Ricardo Bigolin, Schroeder, Joyce D., and Tasdizen, Tolga

Subjects
Computer Science - Computer Vision and Pattern Recognition, Electrical Engineering and Systems Science - Image and Video Processing
Abstract

Convolutional neural networks (CNNs) have been successfully applied to chest x-ray (CXR) images. Moreover, annotated bounding boxes have been shown to improve the interpretability of a CNN in terms of localizing abnormalities. However, only a few relatively small CXR datasets containing bounding boxes are available, and collecting them is very costly. Opportunely, eye-tracking (ET) data can be collected in a non-intrusive way during the clinical workflow of a radiologist. We use ET data recorded from radiologists while dictating CXR reports to train CNNs. We extract snippets from the ET data by associating them with the dictation of keywords and use them to supervise the localization of specific abnormalities. We show that this method improves a model's interpretability without impacting its image-level classification.

Published
2022

4. Comparing radiologists' gaze and saliency maps generated by interpretability methods for chest x-rays

Author

Lanfredi, Ricardo Bigolin, Arora, Ambuj, Drew, Trafton, Schroeder, Joyce D., and Tasdizen, Tolga

Subjects
Computer Science - Computer Vision and Pattern Recognition, Electrical Engineering and Systems Science - Image and Video Processing
Abstract

The interpretability of medical image analysis models is considered a key research field. We use a dataset of eye-tracking data from five radiologists to compare the outputs of interpretability methods and the heatmaps representing where radiologists looked. We conduct a class-independent analysis of the saliency maps generated by two methods selected from the literature: Grad-CAM and attention maps from an attention-gated model. For the comparison, we use shuffled metrics, which avoid biases from fixation locations. We achieve scores comparable to an interobserver baseline in one shuffled metric, highlighting the potential of saliency maps from Grad-CAM to mimic a radiologist's attention over an image. We also divide the dataset into subsets to evaluate in which cases similarities are higher., Comment: This paper was presented as an Extended Abstract at the Gaze Meets ML 2022 Workshop, a NeurIPS 2022 workshop

Published
2021

5. REFLACX, a dataset of reports and eye-tracking data for localization of abnormalities in chest x-rays

Author

Lanfredi, Ricardo Bigolin, Zhang, Mingyuan, Auffermann, William F., Chan, Jessica, Duong, Phuong-Anh T., Srikumar, Vivek, Drew, Trafton, Schroeder, Joyce D., and Tasdizen, Tolga

Subjects
Electrical Engineering and Systems Science - Image and Video Processing, Computer Science - Computer Vision and Pattern Recognition
Abstract

Deep learning has shown recent success in classifying anomalies in chest x-rays, but datasets are still small compared to natural image datasets. Supervision of abnormality localization has been shown to improve trained models, partially compensating for dataset sizes. However, explicitly labeling these anomalies requires an expert and is very time-consuming. We propose a potentially scalable method for collecting implicit localization data using an eye tracker to capture gaze locations and a microphone to capture a dictation of a report, imitating the setup of a reading room. The resulting REFLACX (Reports and Eye-Tracking Data for Localization of Abnormalities in Chest X-rays) dataset was labeled across five radiologists and contains 3,032 synchronized sets of eye-tracking data and timestamped report transcriptions for 2,616 chest x-rays from the MIMIC-CXR dataset. We also provide auxiliary annotations, including bounding boxes around lungs and heart and validation labels consisting of ellipses localizing abnormalities and image-level labels. Furthermore, a small subset of the data contains readings from all radiologists, allowing for the calculation of inter-rater scores., Comment: Supplementary material included as ancillary files. Update 1: added clarifications and a graph showing the time correlation between gaze and report. Update 2: This preprint has not undergone peer review or any post-submission improvements or corrections. The Version of Record of this article is published in Scientific Data, and is available online at https://doi.org/10.1038/s41597-022-01441-z

Published
2021
Full Text
View/download PDF

6. Student Perception of Peer Review in the Digital Age

Author

Bigolin, Marcio, Reategui, Eliseo, García Cabeza, Sofía, Motz, Regina, Huang, Ronghuai, Series Editor, Kinshuk, Series Editor, Jemni, Mohamed, Series Editor, Chen, Nian-Shing, Series Editor, Spector, J. Michael, Series Editor, and Berrezueta, Santiago, editor

Published
2023
Full Text
View/download PDF

7. Quantifying the Preferential Direction of the Model Gradient in Adversarial Training With Projected Gradient Descent

Author

Lanfredi, Ricardo Bigolin, Schroeder, Joyce D., and Tasdizen, Tolga

Subjects
Statistics - Machine Learning, Computer Science - Computer Vision and Pattern Recognition, Computer Science - Machine Learning
Abstract

Adversarial training, especially projected gradient descent (PGD), has proven to be a successful approach for improving robustness against adversarial attacks. After adversarial training, gradients of models with respect to their inputs have a preferential direction. However, the direction of alignment is not mathematically well established, making it difficult to evaluate quantitatively. We propose a novel definition of this direction as the direction of the vector pointing toward the closest point of the support of the closest inaccurate class in decision space. To evaluate the alignment with this direction after adversarial training, we apply a metric that uses generative adversarial networks to produce the smallest residual needed to change the class present in the image. We show that PGD-trained models have a higher alignment than the baseline according to our definition, that our metric presents higher alignment values than a competing metric formulation, and that enforcing this alignment increases the robustness of models., Comment: This paper was published in Pattern Recognition

Published
2020
Full Text
View/download PDF

8. Interpretation of Disease Evidence for Medical Images Using Adversarial Deformation Fields

Author

Lanfredi, Ricardo Bigolin, Schroeder, Joyce D., Vachet, Clement, and Tasdizen, Tolga

Subjects
Electrical Engineering and Systems Science - Image and Video Processing, Computer Science - Computer Vision and Pattern Recognition, Computer Science - Graphics, Quantitative Biology - Quantitative Methods
Abstract

The high complexity of deep learning models is associated with the difficulty of explaining what evidence they recognize as correlating with specific disease labels. This information is critical for building trust in models and finding their biases. Until now, automated deep learning visualization solutions have identified regions of images used by classifiers, but these solutions are too coarse, too noisy, or have a limited representation of the way images can change. We propose a novel method for formulating and presenting spatial explanations of disease evidence, called deformation field interpretation with generative adversarial networks (DeFI-GAN). An adversarially trained generator produces deformation fields that modify images of diseased patients to resemble images of healthy patients. We validate the method studying chronic obstructive pulmonary disease (COPD) evidence in chest x-rays (CXRs) and Alzheimer's disease (AD) evidence in brain MRIs. When extracting disease evidence in longitudinal data, we show compelling results against a baseline producing difference maps. DeFI-GAN also highlights disease biomarkers not found by previous methods and potential biases that may help in investigations of the dataset and of the adopted learning methods., Comment: Presented at MICCAI 2020

Published
2020
Full Text
View/download PDF

9. Recent HIV infection and annualized HIV incidence rates among sexual and gender minorities in Brazil and Peru (ImPrEP seroincidence study): a cross-sectional, multicenter study

Author

Kristic, Tania, Rocha, Carla, da Silva Santos, Willian, Lovreto Santana, Ana Paula, Lima, Renato, Souza, Carolina, Oliva, Talita Andrade, Valões, Mônica dos Santos, Olivetto, Jennifer, Mota, Gabriel Lima, Cano, Aline Barnabé, Trefiglio, Roberta, Coutinho, Carolina, Elorreaga, Oliver, Gutierrez, Ximena, Olivos, Fernando, Caviedes, Damaris, Adriazola, Daniella, Juárez, Eduardo, Mariño, Gabriela, Qquellon, Jazmin, Vasquez, Francesca, Jiron, Jean Pierre, Flores, Sonia, Campos, Karen, Eguiluz, Maria, Torres, Thiago S., Teixeira, Sylvia L.M., Hoagland, Brenda, Konda, Kelika A., Derrico, Monica, Moreira, Ronaldo I., Guanira, Juan V., Benedetti, Marcos, Nazer, Sandro, Calvo, Gino M., Vargas, Silver, Benites, Carlos, Bigolin, Álisson, Alonso Neto, José Boullosa, Farias, Alessandro, Guimarães Lacerda, Marcos Vinícius, Raenck Silva, Daila Alena, Paz, Leidijany Costa, Madruga, José Valdez, Salvatierra Flores, Hector Javier, Boluarte, Ginjaylan Prada, Osco Tamayo, Cesar Vidal, Castro Antezana, Hardy Teresa, Pimenta, M. Cristina, Bórquez, Annick, Luz, Paula M., Grinsztejn, Beatriz, Szwarcwald, Celia Landmann, Cáceres, Carlos F., and Veloso, Valdilea G.

Published
2023
Full Text
View/download PDF

10. Adversarial regression training for visualizing the progression of chronic obstructive pulmonary disease with chest x-rays

Author

Lanfredi, Ricardo Bigolin, Schroeder, Joyce D., Vachet, Clement, and Tasdizen, Tolga

Subjects
Electrical Engineering and Systems Science - Image and Video Processing, Computer Science - Computer Vision and Pattern Recognition, Computer Science - Graphics
Abstract

Knowledge of what spatial elements of medical images deep learning methods use as evidence is important for model interpretability, trustiness, and validation. There is a lack of such techniques for models in regression tasks. We propose a method, called visualization for regression with a generative adversarial network (VR-GAN), for formulating adversarial training specifically for datasets containing regression target values characterizing disease severity. We use a conditional generative adversarial network where the generator attempts to learn to shift the output of a regressor through creating disease effect maps that are added to the original images. Meanwhile, the regressor is trained to predict the original regression value for the modified images. A model trained with this technique learns to provide visualization for how the image would appear at different stages of the disease. We analyze our method in a dataset of chest x-rays associated with pulmonary function tests, used for diagnosing chronic obstructive pulmonary disease (COPD). For validation, we compute the difference of two registered x-rays of the same patient at different time points and correlate it to the generated disease effect map. The proposed method outperforms a technique based on classification and provides realistic-looking images, making modifications to images following what radiologists usually observe for this disease. Implementation code is available at https://github.com/ricbl/vrgan., Comment: Accepted for MICCAI 2019

Published
2019
Full Text
View/download PDF

15. Evaluating the Performance of SOBEK Text Mining Keyword Extraction Algorithm

Author

Reategui, Eliseo, Bigolin, Marcio, Carniato, Michel, dos Santos, Rafael Antunes, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Holzinger, Andreas, editor, Kieseberg, Peter, editor, Tjoa, A Min, editor, and Weippl, Edgar, editor

Published
2022
Full Text
View/download PDF

18. Interpretation of Disease Evidence for Medical Images Using Adversarial Deformation Fields

Author

Bigolin Lanfredi, Ricardo, Schroeder, Joyce D., Vachet, Clement, Tasdizen, Tolga, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Woeginger, Gerhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Martel, Anne L., editor, Abolmaesumi, Purang, editor, Stoyanov, Danail, editor, Mateus, Diana, editor, Zuluaga, Maria A., editor, Zhou, S. Kevin, editor, Racoceanu, Daniel, editor, and Joskowicz, Leo, editor

Published
2020
Full Text
View/download PDF

20. Adversarial Regression Training for Visualizing the Progression of Chronic Obstructive Pulmonary Disease with Chest X-Rays

Author

Bigolin Lanfredi, Ricardo, Schroeder, Joyce D., Vachet, Clement, Tasdizen, Tolga, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Woeginger, Gerhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Shen, Dinggang, editor, Liu, Tianming, editor, Peters, Terry M., editor, Staib, Lawrence H., editor, Essert, Caroline, editor, Zhou, Sean, editor, Yap, Pew-Thian, editor, and Khan, Ali, editor

Published
2019
Full Text
View/download PDF

21. Intrinsic Lipschitz graphs in Heisenberg groups and continuous solutions of a balance equation

Author

Bigolin, Francesco, Caravenna, Laura, and Cassano, Francesco Serra

Subjects
Mathematics - Differential Geometry, Mathematics - Analysis of PDEs, 53C17, 35L60, 49Q15
Abstract

In this paper we provide a characterization of intrinsic Lipschitz graphs in the sub-Riemannian Heisenberg groups in terms of their distributional gradients. Moreover, we prove the equivalence of different notions of continuous weak solutions to the equation \phi_y+ [\phi^{2}/2]_t=w, where w is a bounded function depending on \phi.

Published
2012
Full Text
View/download PDF

22. Geometric Characterizations of C1 Manifold in Euclidean Spaces by Tangent Cones

Author

Bigolin, Francesco and Greco, Gabriele H.

Subjects
Mathematics - Differential Geometry, 58A05, 49Q99 (Primary) 01A60, 01A61 (Secondary)
Abstract

A remarkable and elementary fact that a locally compact set F of Euclidean space is a smooth manifold if and only if the lower and upper paratangent cones to F coincide at every point, is proved. The celebrated von Neumann's result (1929) that a locally compact subgroup of the general linear group is a smooth manifold, is a straightforward application. A historical account on the subject is provided in order to enrich the mathematical panorama. Old characterizations of smooth manifold (by tangent cones), due to Valiron (1926, 1927) and Severi (1929, 1934) are recovered; modern characterizations, due to Gluck (1966, 1968), Tierno (1997), Shchepin and Repovs (2000) are restated., Comment: 32 pages, 5 figures

Published
2012

24. Evaluation of the performance of Dutch Lipid Clinic Network score in an Italian FH population: The LIPIGEN study

Author

Arca, Marcello, Averna, Maurizio, Bertolini, Stefano, Calandra, Sebastiano, Catapano, Alberico Luigi, Tarugi, Patrizia, Pellegatta, Fabio, Angelico, Francesco, Bartuli, Andrea, Biasucci, Giacomo, Biolo, Gianni, Bonanni, Luca, Bonomo, Katia, Borghi, Claudio, Bossi, Antonio Carlo, Branchi, Adriana, Carubbi, Francesca, Cipollone, Francesco, Citroni, Nadia, Federici, Massimo, Ferri, Claudio, Fiorenza, Anna Maria, Giaccari, Andrea, Giorgino, Francesco, Guardamagna, Ornella, Iannuzzi, Arcangelo, Iughetti, Lorenzo, Lupattelli, Graziana, Lupi, Alessandro, Mandraffino, Giuseppe, Marcucci, Rossella, Maroni, Lorenzo, Miccoli, Roberto, Mombelli, Giuliana, Muntoni, Sandro, Pecchioli, Valerio, Pederiva, Cristina, Pipolo, Antonio, Pisciotta, Livia, Pujia, Arturo, Purrello, Francesco, Repetti, Elena, Rubba, Paolo, Sabbà, Carlo, Sampietro, Tiziana, Sarzani, Riccardo, Tagliabue, Milena Paola, Trenti, Chiara, Vigna, Giovanni Battista, Werba, Josè Pablo, Zambon, Sabina, Zenti, Maria Grazia, Minicocci, Ilenia, Noto, Davide, Fortunato, Giuliana, Banderali, Giuseppe, Benso, Andrea, Bigolin, Paola, Bonora, Enzo, Bruzzi, Patrizia, Bucci, Marco, Buonuomo, Paola Sabrina, Capra, Maria Elena, Cardolini, Iris, Cefalù, Baldassarre, Cervelli, Nazzareno, Chiariello, Giuseppe, Cocci, Guido, Colombo, Emanuela, Cremonini, Anna Laura, D'Addato, Sergio, D'Erasmo, Laura, Dal Pino, Beatrice, De Sanctis, Luisa, De Vita, Emanuele, Del Ben, Maria, Di Costanzo, Alessia, Di Taranto, Maria Donata, Fasano, Tommaso, Gentile, Luigi, Gentile, Marco, Ghirardello, Omar, Grigore, Liliana, Lussu, Milena, Meregalli, Giancarla, Moffa, Simona, Montalcini, Tiziana, Morgia, Valeria, Nascimbeni, Fabio, Pasta, Andrea, Pavanello, Chiara, Saitta, Antonino, Scicali, Roberto, Siepi, Donatella, Spagnolli, Walter, Spina, Rossella, Sticchi, Elena, Suppressa, Patrizia, Vigo, Lorenzo, Vinci, Pierandrea, Casula, Manuela, Manzato, Enzo, Olmastroni, Elena, Tragni, Elena, Zampoleri, Veronica, and Pirillo, Angela

Published
2018
Full Text
View/download PDF

29. Vaping and Hookah Use Among Medical Trainees: A Multinational Survey Study

Author

Degani-Costa, Luiza Helena, (PI), Gushken, Fernanda, Szlejf, Claudia, Fernandes, João Roberto Resende, Fidalgo, Thiago M, (PI), Degani-Costa, Luiza Helena, Bruno, Fernando Pereira, Tokeshi, Ana B, Douradinho, Christian, Pinto Corrêa, Paulo César Rodrigues, Aguiar Brandão, Antonio Carlos, Campos, Vilson Geraldo, Gandolfo, Lara, Pires, Oscar César, De Mello, Ramon Andrade Bezerra, Knorst, Marli Maria, Carvalho Pessôa, Carlos Leonardo, Golmia, Ricardo, da Silva, Guilherme Borges Gomes, Antônio, Karine Corcione Turke, Carla, Carlos Palandri Chagas, Lantieri, Janice Baister, De Marchi, Yasmin Paz, Heringer, Daniel Lacerda, Valente, Bruna Granig, David, Larissa Moreira, Souza, Carolina Lacerda, Ramos, Juliana Monteiro, de Almeida, Rafael Moura, Bentes, Thainá Mendonça, Kami, Vinicius Ryu, Lucchetti, Giancarlo, Silveira, Marina Toscano, Barros, Arthur Somavila, Hauli, Vicente Bigolin, da Silva Bouzas, Luis Fernando, de Carvalho, Antonia Worcman, Guerra, Juliana Moreira, Benchimol, Gabriel Lima, Alves, Lincoln Basílio, Luz, Victória Mourão, Resende, Caroline Meneses, da Silva Sena, Antonio Andrei, Mendes Sales, Ana Karoline, Pereira, Gabriel Victor Silva, Mohta, Aditi, Kumar, Pentapati SS, Jamir, Limalemla, Prasad, Kandipudi K L, (PI), Bhimarasetty, Devi Madhavi, Lakshmi, Makineedi Rama, Neeluri, Rajesh, V, Mahesh, Shinde, Pradnya V., Bonu, Radha Ramani, Boovaragasamy, Chithra, Gnanasabai, Gnanamani, Oberoi, Simmi, Singh, Aman Dev, Nandan, Tumul, Bruno, Fernando Pereira, (PI), Tehrani, Yasmin F, Kaufman, Daniel, Ghassemi, Cameron, Benesch, Matthew GK, (PI), Ryan, Morag G, Fuld, Jonathan P, (PI), Lotay, Hardeep, Bruno, Fernando P., Tokeshi, Ana B., Tehrani, Yasmin F., Prasad, Kandipudi K.L., Kumar, Pentapati S.S., Benesch, Matthew G.K., Ryan, Morag G., Fuld, Jonathan P., and Fidalgo, Thiago M.

Published
2023
Full Text
View/download PDF

32. Relationship between the timing of administration of IgM and IgA enriched immunoglobulins in patients with severe sepsis and septic shock and the outcome: A retrospective analysis

Author

Berlot, Giorgio, Vassallo, Michele C., Busetto, Nicola, Bianchi, Monica, Zornada, Francesca, Rosato, Ivana, Tartamella, Fabiana, Prisco, Lara, Bigotto, Federica, Bigolin, Tiziana, Ferluga, Massimo, Batticci, Irene, Michelone, Enrico, Borelli, Massimo, Viviani, Marino, and Tomasini, Ariella

Published
2012
Full Text
View/download PDF

43. Radiological evaluation of the patency of duodenal-esophageal anastomosis during a long postoperative follow-up: effectiveness of an alkaline reflux model in rats

Author

Cavazzola L, Bigolin AV, Grossi JV, Montes JH, and Nicola RF

Subjects
Diseases of the digestive system. Gastroenterology, RC799-869
Abstract

André Vicente Bigolin1, João Vicente Grossi2, Juliano Hermes Maeso Montes1, Roberto Nicola1, Leandro Totti Cavazzola11School of Medicine, Lutheran University of Brazil, Canoas; 2Hospital de Pronto Socorro de Porto Alegre, Department of Surgery, Porto Alegre, Rio Grande do Sul, BrazilBackground: Performing experimental studies has played an important role in acquiring knowledge about esophageal carcinogenesis. In this context, the choice of a more reliable experimental model requires proof of its effectiveness in order to lend greater credibility to the results. The objective of this study was to evaluate the patency of duodenal-esophageal anastomosis during long-term postoperative follow-up in rats.Methods: This was an experimental study in which 45 female Wistar rats were used. A side-to-side anastomosis was performed, going from the anterior side of the esophagus to the second duodenal portion. A standardized radiological technique was used to carry out a contrasted radiological study of the esophagus, stomach, and duodenum during weeks 4, 12, 20, and 30 after surgery. Different contrast media were used, and the animals were divided into groups, ie, group 1 (100% barium sulfate), group 2 (50% barium sulfate), and group 3 (60% aqueous iodinated contrast media). Contrast radiographs were taken in each group at weeks 4, 12, 20, and 30 after the surgical procedure. The radiographic images were evaluated by two radiologists who were blinded regarding the contrast groups. Macroscopic evaluation of each animal was compared with the radiological findings.Results: Postoperative mortality was 13.33%. The remaining animals were divided into study groups. All the contrast radiological examinations showed evidence of the location of the esophagus, stomach, and proximal portion of the intestine, and demonstrated the laterolateral relationship of the distal esophagus and the duodenum in the epigastric region. Patency of the anastomosis was observed at each examination period. The different contrast media used were able to demonstrate this outcome shortly after the first phase of injection. Necropsies corroborated the radiological findings.Conclusion: Regardless of the contrast agent used, contrasted radiography revealed that side-to-side duodenal-esophageal anastomosis in rats allowed patent communication during long-term postoperative follow-up.Keywords: gastroesophageal reflux, esophagus, adenocarcinoma, experimental neoplasm

Published
2011

44. Recent HIV infection and annualized HIV incidence rates among sexual and gender minorities in Brazil and Peru (ImPrEP seroincidence study): a cross-sectional, multicenter study.

Author

Torres TS, Teixeira SLM, Hoagland B, Konda KA, Derrico M, Moreira RI, Guanira JV, Benedetti M, Nazer S, Calvo GM, Vargas S, Benites C, Bigolin Á, Alonso Neto JB, Farias A, Guimarães Lacerda MV, Raenck Silva DA, Paz LC, Madruga JV, Salvatierra Flores HJ, Boluarte GP, Osco Tamayo CV, Castro Antezana HT, Pimenta MC, Bórquez A, Luz PM, Grinsztejn B, Szwarcwald CL, Cáceres CF, and Veloso VG

Abstract

Background: HIV incidence estimation is critical for monitoring the HIV epidemic dynamics and the effectiveness of public health prevention interventions. We aimed to identify sexual and gender minorities (SGM) with recent HIV infections, factors associated with recent HIV infection, and to estimate annualised HIV incidence rates., Methods: Cross-sectional multicentre study in HIV testing services in Brazil and Peru (15 cities). Inclusion criteria: 18+ years, SGM assigned male at birth, not using pre-/post-exposure prophylaxis. We identified recent HIV infection using the Maxim HIV-1 LAg-Avidity EIA assay as part of a recent infection testing algorithm (RITA). Annualized HIV incidence was calculated using the UNAIDS/WHO incidence estimator tool. Multivariable logistic regression models were used to estimate factors associated with recent HIV infection. Trial registration: NCT05674682., Findings: From 31-Jan-2021 to 29-May-2022, 6899 individuals participated [Brazil: 4586 (66.5%); Peru: 2313 (33.5%)]; 5946 (86.2%) cisgender men, 751 (10.9%) transgender women and 202 (2.9%) non-binary/gender diverse. Median age was 27 (IQR: 23-34) years. HIV prevalence was 11.4% (N = 784/6899); 137 (2.0%) SGM were identified with recent HIV infection. The overall annualized HIV incidence rate was 3.88% (95% CI: 2.86-4.87); Brazil: 2.62% (95% CI: 1.78-3.43); Peru: 6.69% (95% CI: 4.62-8.69). Participants aged 18-24 years had higher odds of recent HIV infection compared to those aged 30+ years in both countries., Interpretation: Our results highlight the significant burden of HIV epidemic among SGM in large urban centres of Brazil and Peru. Public health policies and interventions to increase access to effective HIV prevention methods such as PrEP are urgently needed in Latin America., Funding: Unitaid, WHO (Switzerland), Ministry of Health from Brazil and Peru., Competing Interests: Nothing to declare., (© 2023 The Author(s).)

Published
2023
Full Text
View/download PDF

45. Brazilian Protocol for Sexually Transmitted Infections 2020: syphilis diagnostic tests.

Author

Gaspar PC, Bigolin Á, Alonso Neto JB, Pereira EDDS, and Bazzo ML

Subjects
Brazil, Diagnostic Tests, Routine, Humans, Syphilis Serodiagnosis, Sexually Transmitted Diseases, Syphilis diagnosis
Abstract

The recommendations for diagnostic tests for investigating syphilis are part of the Clinical Protocol and Therapeutic Guidelines for Comprehensive Care for People with Sexually Transmitted Infections and the Technical Manual for Syphilis Diagnosis, published by the Brazilian Ministry of Health. These recommendations were developed based on scientific evidence and discussions with a panel of experts. This article presents direct tests to detect Treponema pallidum in lesions and algorithms that combine treponemal and non-treponemal antibody tests to assist in syphilis diagnosis, with the aim of contributing to the efforts of health service managers and health professionals in qualifying health care. The article also covers the use of non-treponemal tests to investigate neurosyphilis and guidelines for interpreting non-treponemal antibody titers in monitoring the treatment and diagnosis of congenital syphilis, as well as prospects for innovations in diagnosis. The critical role of rapid immunochromatographic treponemal tests for public health and for addressing syphilis is also highlighted. Highlighted excerpt: During the natural evolution of syphilis, activity periods with distinct clinical, immunological, and histopathological characteristics are interspersed with latent periods when there are no signs or symptoms, making access to tests critical for early diagnosis.

Published
2021
Full Text
View/download PDF

46. MICONIDINE acetate, a new selective and cytotoxic compound with synergic potential, induces cell cycle arrest and apoptosis in leukemia cells.

Author

Maioral MF, Stefanes NM, Bigolin Á, Zatelli GA, Philippus AC, de Barcellos Falkenberg M, and Santos-Silva MC

Subjects
Antineoplastic Agents pharmacology, Humans, Leukemia, Myeloid, Acute drug therapy, Leukemia, Myeloid, Acute metabolism, Mitochondria drug effects, Mitochondria metabolism, Mitochondria pathology, Precursor Cell Lymphoblastic Leukemia-Lymphoma drug therapy, Precursor Cell Lymphoblastic Leukemia-Lymphoma metabolism, Reactive Oxygen Species metabolism, Signal Transduction, Tumor Cells, Cultured, Apoptosis drug effects, Cell Cycle Checkpoints drug effects, Hydroquinones pharmacology, Leukemia, Myeloid, Acute pathology, Precursor Cell Lymphoblastic Leukemia-Lymphoma pathology
Abstract

Plants are important sources of biologically active compounds and they provide unlimited opportunities for the discovery and development of new drug leads, including new chemotherapeutics. Miconidin acetate (MA) is a hydroquinone derivative isolated from E. hiemalis. In this study we demonstrated that MA was cytotoxic against acute leukemia (AL), solid tumor cells and cancer stem cells, with the strongest effect exhibited against AL. Furthermore, it was non-cytotoxic against non-tumor cells and did not cause significant hemolysis. MA blocks the G2/M phase and causes cytostatic effects, acting in a similar way to dexamethasone by increasing PML expression. The compound also triggered intrinsic and extrinsic apoptosis by modulating Bax, FasR and survivin expression. This led to an extensive mitochondrial damage that resulted in AIF, cytochrome c and endonuclease G release, caspase-3 and PARP cleavage and DNA fragmentation. We have further demonstrated that MA was strongly cytotoxic against neoplastic cells collected from patients with different AL subtypes. Interestingly, MA increased the cytotoxic effect of chemotherapeutics cytarabine and vincristine. This study indicates that MA may be a new agent for AL and highlights its potential as a new source of anticancer drugs. Graphical abstract MA blocks G2/M phase with PML expression and KI67 inhibition, ROS generation and intrinsic and extrinsic apoptosis, leading to mitochondrial damage, caspase 3 and PARP cleavage and DNA fragmentation.

Published
2019
Full Text
View/download PDF

47. Synthesis of novel pyrazoline derivatives and the evaluation of death mechanisms involved in their antileukemic activity.

Author

Stefanes NM, Toigo J, Maioral MF, Jacques AV, Chiaradia-Delatorre LD, Perondi DM, Ribeiro AAB, Bigolin Á, Pirath IMS, Duarte BF, Nunes RJ, and Santos-Silva MC

Subjects
Acute Disease, Antineoplastic Agents chemical synthesis, Antineoplastic Agents chemistry, Apoptosis Inducing Factor metabolism, Caspase 3 metabolism, Cell Line, Tumor, Cell Proliferation drug effects, Drug Screening Assays, Antitumor, Humans, Leukemia drug therapy, Membrane Potential, Mitochondrial drug effects, Proto-Oncogene Proteins c-bcl-2 metabolism, Pyrazoles chemical synthesis, Pyrazoles chemistry, S Phase Cell Cycle Checkpoints drug effects, Survivin metabolism, bcl-2-Associated X Protein metabolism, Antineoplastic Agents pharmacology, Apoptosis drug effects, Pyrazoles pharmacology
Abstract

Malignant neoplasms are one of the leading causes of death worldwide and hematologic malignancies, including acute leukemia (AL) is one of the most relevant cancer types. Current available chemotherapeutics are associated with high morbidity and mortality rates, therefore, the search for new molecules with antitumor activity, specific and selective for neoplastic cells, became a great challenge for researchers in the oncology field. As pyrazolines stand out in the literature for their great variety of biological activities, the aim of this study was to synthesize and evaluate the antileukemic activity of five new pyrazoline derivatives. All pyrazolines showed adequate physicochemical properties for a good oral bioavailability. The two unpublished and most effective pyrazoline derivatives have been selected for further experiments. These compounds are highly selective for leukemic cells when compared to non-neoplastic cells and did not cause lysis on human red blood cells. Additionally, selected pyrazolines induced cell cycle arrest at G0/G1 phase and decreased cell proliferation marker KI67. Apoptotic cell death induced by selected pyrazolines was confirmed by morphological analysis, assessment of phosphatidylserine residue exposure and DNA fragmentation. Several factors indicate that both intrinsic and extrinsic apoptosis occurred. These were: increased FasR expression; the predominance of Bax in relation to Bcl-2; the loss of mitochondrial membrane potential; AIF release; decreased expression of survivin (an antiapoptotic protein); and the activation of caspase-3. The selected pyrazolines were also found to be cytotoxic against neoplastic cells collected from the peripheral blood and bone marrow of patients with different subtypes of acute leukemia., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Published
2019
Full Text
View/download PDF

48. Cytotoxic effect of a novel naphthylchalcone against multiple cancer cells focusing on hematologic malignancies.

Author

Maioral MF, Bodack CDN, Stefanes NM, Bigolin Á, Mascarello A, Chiaradia-Delatorre LD, Yunes RA, Nunes RJ, and Santos-Silva MC

Subjects
A549 Cells, Animals, Drug Screening Assays, Antitumor, Female, HL-60 Cells, HeLa Cells, Hematologic Neoplasms genetics, Hematologic Neoplasms metabolism, Hematologic Neoplasms pathology, Humans, Jurkat Cells, Male, Mice, NIH 3T3 Cells, Neoplasm Proteins genetics, U937 Cells, Apoptosis drug effects, Chalcones chemical synthesis, Chalcones chemistry, Chalcones pharmacology, Cytotoxins chemical synthesis, Cytotoxins chemistry, Cytotoxins pharmacology, Gene Expression Regulation, Neoplastic drug effects, Hematologic Neoplasms drug therapy, Neoplasm Proteins biosynthesis
Abstract

Chalcones are natural compounds described in the literature by its several properties including cytotoxic activity against several tumor types. Considering that the search for new chemotherapeutic agents is still necessary, the aim of this study was to investigate the cytotoxic mechanisms involved in cell death induced by a synthetic chalcone (A23) on different tumor cells. Chalcone A23 reduced the cell viability of twelve tumor cell lines in a concentration and time dependent manner and it was more cytotoxic against acute leukemia cells. Interestingly, the compound was non cytotoxic to normal cells and non-hemolytic to normal red blood cells. Chalcone A23 decreased the expression of cell proliferation marker KI-67 and blocked the G2/M phase in both K562 and Jurkat cell lines. Cells treated with A23 showed morphological features suggestive of apoptosis, the "latter pattern" in agarose gel, the externalization of phosphatidylserine and caspase-3 and PARP cleavage. Chalcone A23 significantly reduced the mitochondrial membrane potential, decreased the expression of anti-apoptotic proteins Bcl-2 and survivin and increased the expression of pro-apoptotic protein Bax, confirming the involvement of the intrinsic pathway. The increased mitochondrial permeability resulted in the release of AIF, cytochrome c and endonuclease G from the mitochondria to the cytosol. In addition, chalcone A23 increased the expression of FasR and induced Bid cleavage, showing the involvement of the extrinsic pathway. Finally, chalcone A23 seems to have a synergic effect with the chemotherapy drugs cytarabine and vincristine. These results suggest that A23 is an interesting compound with strong and selective anti-tumor activity., (Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.)

Published
2017
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results