Point Projection Mapping System for Tracking, Registering, Labeling and Validating Optical Tissue Measurements

Validation of newly developed optical tissue sensing techniques for tumor detection during cancer surgery requires an accurate correlation with histological results. Additionally, such accurate correlation facilitates precise data labeling for developing high-performance machine-learning tissue classification models. In this paper, a newly developed Point Projection Mapping system will be introduced, which allows non-destructive tracking of the measurement locations on tissue specimens. Additionally, a framework for accurate registration, validation, and labeling with histopathology results is proposed and validated on a case study. The proposed framework provides a more robust and accurate method for tracking and validation of optical tissue sensing techniques, which saves time and resources compared to conventional techniques available

Guia para aquisição de imagens em microscópio óptico com interface gráfica

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Resection Ratios and Tumor Eccentricity in Breast-Conserving Surgery Specimens for Surgical Accuracy Assessment

This study aims to evaluate several defined specimen parameters that would allow to determine the surgical accuracy of breast-conserving surgeries (BCS) in a representative population of patients. These specimen parameters could be used to compare surgical accuracy when using novel technologies for intra-operative BCS guidance in the future. Different specimen parameters were determined among 100 BCS patients, including the ratio of specimen volume to tumor volume (resection ratio) with different optimal margin widths (0 mm, 1 mm, 2 mm, and 10 mm). Furthermore, the tumor eccentricity [maximum tumor-margin distance − minimum tumor-margin distance] and the relative tumor eccentricity [tumor eccentricity ÷ pathological tumor diameter] were determined. Different patient subgroups were compared using Wilcoxon rank sum tests. When using a surgical margin width of 0 mm, 1 mm, 2 mm, and 10 mm, on average, 19.16 (IQR 44.36), 9.94 (IQR 18.09), 6.06 (IQR 9.69) and 1.35 (IQR 1.78) times the ideal resection volume was excised, respectively. The median tumor eccentricity among the entire patient population was 11.29 mm (SD = 3.99) and the median relative tumor eccentricity was 0.66 (SD = 2.22). Resection ratios based on different optimal margin widths (0 mm, 1 mm, 2 mm, and 10 mm) and the (relative) tumor eccentricity could be valuable outcome measures to evaluate the surgical accuracy of novel technologies for intra-operative BCS guidance.</p

Margin assessment during breast conserving surgery using diffuse reflectance spectroscopy

Significance: During breast-conserving surgeries, it is essential to evaluate the resection margins (edges of breast specimen) to determine whether the tumor has been removed completely. In current surgical practice, there are no methods available to aid in accurate real-time margin evaluation.Aim: In this study, we investigated the diagnostic accuracy of diffuse reflectance spectroscopy (DRS) combined with tissue classification models in discriminating tumorous tissue from healthy tissue up to 2 mm in depth on the actual resection margin of in vivo breast tissue.Approach: We collected an extensive dataset of DRS measurements on ex vivo breast tissue and in vivo breast tissue, which we used to develop different classification models for tissue classification. Next, these models were used in vivo to evaluate the performance of DRS for tissue discrimination during breast conserving surgery. We investigated which training strategy yielded optimum results for the classification model with the highest performance.Results: We achieved a Matthews correlation coefficient of 0.76, a sensitivity of 96.7% (95% CI 95.6% to 98.2%), a specificity of 90.6% (95% CI 86.3% to 97.9%) and an area under the curve of 0.98 by training the optimum model on a combination of ex vivo and in vivo DRS data.Conclusions: DRS allows real-time margin assessment with a high sensitivity and specificity during breast-conserving surgeries.</p

Diffuse reflectance spectroscopy for accurate margin assessment in breast-conserving surgeries:importance of an optimal number of fibers

During breast-conserving surgeries, it remains challenging to accomplish adequate surgical margins. We investigated different numbers of fibers for fiber-optic diffuse reflectance spectroscopy to differentiate tumorous breast tissue from healthy tissue ex vivo up to 2 mm from the margin. Using a machine-learning classification model, the optimal performance was obtained using at least three emitting fibers (Matthew's correlation coefficient (MCC) of 0.73), which was significantly higher compared to the performance of using a single-emitting fiber (MCC of 0.48). The percentage of correctly classified tumor locations varied from 75% to 100% depending on the tumor percentage, the tumor-margin distance and the number of fibers.</p

Rabdomiólise em militares: uma missão de reconhecimento para prevenção.

O treinamento físico regular faz parte do cotidiano militar, com intuito de aprimorar competências físicas essenciais para tarefas de combate. No entanto, quando executado de forma extenuante ou desenvolvido em condições climáticas adversas pode ocasionar o desenvolvimento da rabdomiólise por esforço físico. A rabdomiólise por esforço físico é definida como uma síndrome decorrente da necrose das células musculares, com sintomas variáveis, como dor muscular, fraqueza e aumento plasmático de enzimas musculares. A severidade da rabdomiólise por esforço físico varia individualmente, porém, pode se tornar clinicamente relevante, contribuindo para a hospitalização, insuficiência renal aguda, incapacidade permanente ou óbito. Sendo assim, o objetivo desta revisão narrativa é apresentar possíveis causas e fatores de risco para rabdomiólise, discutir sua fisiopatologia, seus possíveis diagnósticos e suas principais complicações, enfatizando o contexto militar

Apresentação clínica do câncer gástrico em paciente portador de HIV / Clinical presentation of gastric cancer in patient with HIV

Introdução: O câncer gástrico é uma das neoplasias mais comuns e apresenta alta mortalidade, sendo considerado a segunda causa de morte mundialmente. Objetivo: Relatar essa patologia em um paciente portador do HIV da cidade de Manaus - AM e explorar o caso clínico exposto. Metodologia: Pesquisa descritiva e exploratória com coleta dos dados clínicos através do prontuário e consulta em base de dados. Resultados: Paciente E.G.S., sexo masculino, 58 anos, pardo, divorciado, natural do Careiro da Várzea (AM), procedente de Manaus (AM), vendedor. Paciente portador do vírus HIV há 6 anos em uso de TARV regularmente e com carga viral não detectável, com 3 meses evolução clínica sugestiva de neoplasia gástrica que a endoscopia apresentou lesão ulcerada em corpo e antro gástrico, Bormann lll. Sendo confirmado pelo histopatológico como adenocarcinoma gástrico tubular moderadamente diferenciado. Discussão: O grau de imunossupressão tem uma profunda influência negativa sobre incidência e resultado do carcinoma. Um estudo de autópsia em pacientes com AIDS apresentou doenças do TGI em 79%. As pessoas com infecção pelo HIV desenvolvem tipos de câncer não relacionados à AIDS mais frequentemente do que a população geral. O principal tratamento do adenocarcinoma gástrico é a ressecção do tumor, seja ela cirúrgica ou endoscópica, porem a escolha do tratamento depende do estadiamento. Os fatores prognósticos observados nesse relato de caso cursam com os achados na literatura: sexo masculino, sexta década de vida, ulcerações em antro e corpo gástrico, diagnóstico e tratamento no estágio avançado da doença, assim como os sintomas relatados: dor abdominal, anorexia e perda ponderal. Considerações finais: Este caso reflete um caso clássico de câncer gástrico e demostra a associação existente entre o HIV e os canceres que não são diretamente relacionados a esse vírus, refletindo os achados da literatura. 

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Estimating the global conservation status of more than 15,000 Amazonian tree species

Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century