208 research outputs found
Deep learning systems and methodologies for Spitz melanocytic tumour analysis
No full text[ES] El avance de la inteligencia artificial ha revolucionado muchos campos, incluyendo la patología digital. La digitalización de biopsias en whole slide images de alta resolución ha permitido aplicar metodologías de aprendizaje profundo para ayudar en el diagnóstico, asistir a los patólogos e incluso reducir errores. Sin embargo, a pesar de su potencial, este campo sigue sujeto a retos importantes, tanto en lo que respecta a los datos como a la integración práctica de la inteligencia artificial en entornos clínicos. Superar estos obstáculos requiere abordar la complejidad de las imágenes histopatológicas de alta resolución, la escasez de datos de entrenamiento y la integración efectiva de estas herramientas en la práctica.
Estas limitaciones pueden verse aún más pronunciadas en el caso de enfermedades menos comunes, donde la investigación clínica es compleja y, a menudo, limitada. Cánceres poco comunes, como los tumores melanocíticos de Spitz, suponen dificultades adicionales debido a su baja incidencia y su difícil interpretación clínica, lo que complica tanto la investigación en este ámbito como la aplicación de métodos de inteligencia artificial.
Esta tesis aborda parte de estos desafíos mediante la exploración e implementación de diferentes estrategias de aprendizaje profundo adaptadas al contexto de la patología digital y sus retos, con un enfoque particular en los tumores de Spitz. En concreto, esta tesis investiga la aplicación de metodologías como el multiple instance learning, active learning, self-training y federated learning para mitigar los desafíos inherentes al campo de la patología digital, manteniendo un enfoque práctico hacia la integración clínica. Este trabajo, posicionado en la intersección entre la inteligencia artificial y los sistemas de información, busca sentar las bases para futuras investigaciones sobre los tumores de Spitz basadas en sistemas inteligentes.[CA] L'avanç de la intel·ligència artificial ha revolucionat molts camps, incloent-hi la patologia digital. La digitalització de biòpsies en whole slide images d'alta resolució ha permés aplicar metodologies d'aprenentatge profund per a ajudar en el diagnòstic, assistir als patòlegs i fins i tot reduir errors. No obstant això, malgrat el seu potencial, este camp seguix subjecte a reptes importants, tant pel que fa a les dades com a la integració pràctica de la intel·ligència artificial en entorns clínics. Superar estos obstacles requerix abordar la complexitat de les imatges histopatològiques d'alta resolució, l'escassetat de dades d'entrenament i la integració efectiva d'estes ferramentes en la pràctica.
Estes limitacions poden veure's encara més pronunciades en el cas de malalties menys comunes, on la investigació clínica és complexa i, sovint, limitada. Càncers poc comuns, com els tumors melanocítics de Spitz, suposen dificultats addicionals a causa de la seua baixa incidència i la seua difícil interpretació clínica, la qual cosa complica tant la investigació en este àmbit com l'aplicació de mètodes d'intel·ligència artificial.
Esta tesi aborda part d'estos desafiaments mitjançant l'exploració i implementació de diferents estratègies d'aprenentatge profund adaptades al context de la patologia digital i els seus reptes, amb un enfocament particular en els tumors de Spitz. En concret, esta tesi investiga l'aplicació de metodologies com el multiple instance learning, active learning, self-training i federated learning per a mitigar els desafiaments inherents al camp de la patologia digital, mantenint un enfocament pràctic cap a la integració clínica. Este treball, posicionat en la intersecció entre la intel·ligència artificial i els sistemes d'informació, busca establir les bases per a futures investigacions sobre els tumors de Spitz basades en sistemes intel·ligents.[EN] The advent of artificial intelligence has revolutionised many fields, and digital pathology is no exception. The digitisation of biopsies into whole slide images has enabled the application of deep learning that can assist in diagnosis, support pathologists and ultimately reduce errors. However, despite its great potential, the field still faces significant challenges, both in terms of the data itself and the practical implementation of artificial intelligence in clinical workflows. Addressing these challenges requires overcoming the complexities of high-resolution histopathological images, the constraints posed by limited training data, and the integration of such tools into clinical practice.
These limitations can become even more pronounced in the case of rare diseases, where research is clinically challenging and not always extensive. Rare cancers, such as Spitz melanocytic tumours, pose additional difficulties due to their low incidence and clinical ambiguities, making both research in the field and the application of artificial intelligence more complex.
This thesis addresses part of these challenges by exploring and implementing different deep learning strategies tailored to the complexities of digital pathology, with a particular focus on Spitz tumours. Specifically, this research investigates the application of methodologies such as multiple instance learning, active learning, self-training and federated learning to help mitigate the inherent challenges in digital pathology, while maintaining a practical focus on clinical integration. Positioned at the intersection of artificial intelligence and information systems, this work aims to lay the groundwork for future research on Spitz tumours through artificial intelligence-driven solutions.Launet Gallas, LM. (2025). Deep learning systems and methodologies for Spitz melanocytic tumour analysis [Tesis doctoral]. Universidad Politécnica de Valencia. https://riunet.upv.es/handle/10251/231146TESI
Three contemporary hunting spitz breeds representing breeds with Finnish origins.
No full textThe Nordic Spitz (left), although officially Swedish, the breed originates from feral dogs typical for norther Finland and was brought to Sweden by Finnish settlers. The breed almost went to extinction prior to its recognition in 1966. Finnish Spitz (center) is the Finnish national dog and was established as a breed already in 1892. Karelian Bear Dog (right), a much larger spitz type used for large game hunting, was recognized as a breed in 1936 but registered only in 1946. All photos by the first author.</p
Developmental Change: An Annotated Bibliography
No full textDevelopmental change and the related problems of modernization have attracted the attention of scholars in many disciplines. In this bibliography—derived and expanded from an earlier compilation by Mr. Spitz and Edward Weidner—the author orders and annotates nearly 2,500 articles appearing between 1945 and 1969 in 234 journals from 25 countries. Organized by subject and indexed by both author and journal, the citations include studies of social problems, economic factors, political questions, public administration, and international cooperation and assistance. Special emphasis has been given to new and little-known sources. In addition, a selected bibliography of monographs and book-length studies dealing with the modernization of underdeveloped countries and areas is included in the volume.
Allan A. Spitz is associate professor of political science at the University of Wisconsin at Janesville.https://uknowledge.uky.edu/upk_politics_and_social_change/1002/thumbnail.jp
Clinical, Morphologic, and Genomic Findings in Spitz Tumors With RET Fusion: A Series of 31 Cases
No full textInternational audienceRET-fused Spitz neoplasms represent a rare and poorly characterized category of Spitz tumors. Here we describe the clinical, histologic, and molecular findings of 31 Spitz neoplasms with RET fusion diagnosed as Spitz nevus (n = 16), atypical Spitz tumors (n = 13), and Spitz melanoma (n = 2). The lesions mainly occurred in children and young adults of both sexes with a predilection for the extremities. Microscopically, they were mainly symmetrical compound melanocytic neoplasms with a dome-shaped/slightly raised silhouette predominantly composed of epithelioid, spindled, and/or smaller nevoid melanocytes arranged in confluent nests. Dyscohesive melanocytes within the nests in the upper part of the lesions, prominent Kamino bodies, giant multinucleated melanocytes, variable pigmentation, and increased vascularity with vascular ectasia were frequent features. RNA sequencing detected 9 different 5' (N-terminus) fusion partners, including KIF5B (n = 8), LMNA (n = 7), CCDC6 (n = 6), OPTN (n = 3), MYO5A (n = 2), and NCOA4, ERC1, MYH9, AGAP3 (n = 1). Of these, OPTN::RET and AGAP3::RET represent novel fusions, and 3 further 5' fusion partners, namely NCOA4, ERC1, and MYH9, have never been reported in Spitz tumors. Although as a whole group, the tumors showed a heterogeneous histopathologic presentation, correlation of the morphologic features and the 5' fusion partners demonstrated certain associations. Nevoid melanocytes were exclusively encountered in cases with KIF5B fusion partner. Neuroid-like appearances with intersecting fascicles of spindled cells typified both MYO5A-fused cases. Epithelioid melanocyte population dominated cases with LMNA and CCDC6 fusion partners. Transepidermal elimination/floating intraepidermal nests of pigmented spindled and epithelioid melanocytes were observed in the OPTN subgroup. The remaining cases with less frequent 5' fusion partners manifested in general more atypical histopathologic features, including nuclear pleomorphism, high mitotic count, atypical mitoses, and sheet-like growth pattern. Melanoma fluorescence in situ hybridization probe kit targeting RREB1, MYC, CDKN2A, and CCND1, was negative for copy number variation in 4 cases tested, including 2 cases with complete p16 nuclear loss on immunohistochemistry. Array comparative genomic hybridization was performed in 3 lesions and detected numerous segmental chromosomal imbalances in 2 of them that were diagnosed as Spitz melanoma. DNA and RNA sequencing detected several further genomic alterations, including POU2F3 overexpression in 3 highly pigmented lesions. Further studies are needed to confirm possible correlations between the microscopic features and a particular fusion partner (or additional genetic events) in RET-fused Spitz neoplasms
Correção cirúrgica da persistência do ducto arterioso
No full textPatent ductus arteriosus (PDA) is among the most common congenital heart diseases in dogs and is most frequently detected in young animals. PDA occurs most frequently in small breed dogs, such as Maltese, German Spitz, Chihuahua, and Poodle.A persistência do ducto arterioso (PDA) está entre as mais comuns
cardiopatias congênitas em cães sendo mais frequentemente detectada em
animais jovens. A PDA ocorre com maior frequência em cães de raças pequenas,
Maltês, Spitz Alemão, Chihuahua, Poodle
Glucocerebrosidase mutations in Parkinson\'s disease patients
No full textIntrodução: A doença de Parkinson é uma enfermidade neurodegenerativa decorrente da perda de neurônios dopaminérgicos na substância negra, principalmente, e em outras regiões cerebrais. Caracteriza-se clinicamente por tremor, rigidez, bradicinesia e instabilidade postural. O tratamento é sintomático e consiste essencialmente na reposição da dopamina deficiente. A etiologia da doença de Parkinson ainda não é conhecida, mas os recentes avanços da Neurologia trouxeram novos conhecimentos acerca dos mecanismos fisiopatológicos envolvidos. Disfunção mitocondrial, estresse oxidativo e degradação de proteínas são alguns dos processos celulares que foram relacionados à degeneração dos neurônios dopaminérgicos. O campo da genética da doença de Parkinson tem recebido atenção especial na última década, graças à descoberta de vários genes associados ao desenvolvimento da doença. Um fator de risco genético recentemente descrito é a presença de mutações no gene da glicocerebrosidase, uma enzima lisossomal cuja deficiência resulta na doença de Gaucher. Apesar de a maioria dos estudos já publicados terem confirmado esta associação, um trabalho mais recente da Noruega não encontrou significância estatística ao analisar a presença destas mutações em pacientes com doença de Parkinson, tornando o assunto ainda controverso. Objetivo: Pesquisar a presença de mutações da glicocerebrosidase em pacientes com diagnóstico de doença de Parkinson no Brasil, acompanhados no ambulatório de Distúrbios do Movimento do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo e correlacionar tais achados com estudos recém-publicados que analisaram esta associação em outras populações em âmbito mundial, além de descrever possíveis características dos pacientes portadores de mutações que os diferenciem de não portadores. Métodos: Foram incluídos no estudo 65 pacientes com o diagnóstico de doença de Parkinson e idade de início da doença inferior ou igual a 55 anos e 267 controles sem a doença, emparelhados para sexo e idade. Foi realizada análise genética de material obtido a partir de raspagem da mucosa oral destes indivíduos, tendo sido pesquisadas as três mutações da glicocerebrosidase mais comuns na população brasileira: N370S, L444P e G377S. Resultados: Em dois dos 65 pacientes e em nenhum dos 267 controles foram identificadas mutações no gene da glicocerebrosidase. Os dois pacientes carreadores de mutações (L444P em um e L444P + E326K em outro) apresentavam quadro clínico indistinguível dos demais pacientes com doença de Parkinson não portadores das mutações. Conclusões: Foi observada uma associação estatisticamente significativa (P=0,0379, teste exato de Fisher) entre doença de Parkinson e mutações da glicocerebrosidase na nossa população. A prevalência de mutações da glicocerebrosidase neste grupo de pacientes foi maior do que a esperada para a população geral, porém menor do que a encontrada em estudos internacionais previamente publicados. Espera-se que a identificação desta nova associação permita uma maior compreensão dos mecanismos subjacentes à doença de Parkinson e que em um futuro próximo possa propiciar o desenvolvimento de novas estratégias terapêuticas.Introduction: Parkinson\'s disease is a neurodegenerative disorder due to the loss of dopaminergic neurons in the substantia nigra, primarily, and in other brain regions. It is clinically characterized by tremor, rigidity, bradykinesia and postural instability. Treatment is symptomatic and consists essentially in replacing the deficient dopamine. The etiology of Parkinson\'s disease remains unknown, but recent advances in Neurology have provided data concerning the pathophysiological mechanisms involved. Mithocondrial dysfunction, oxidative stress and protein degradation are some of the cellular processes that have been linked to dopaminergic neurons degeneration. The field of genetics in Parkinson\'s disease has gained special attention in the past decade, thanks to the discovery of several genes associated with the development of the disease. A recently described genetic risk factor for Parkinson\'s disease is the presence of glucocerebrosidase gene mutations. Glucocerebrosidase is a lysosomal enzyme which is deficient in Gaucher disease. Although most studies published to date have confirmed such association, a recent article from Norway could not find statistical significance when Parkinson\'s disease patients were analyzed for glucocerebrosidase mutations, generating controversy. Objective: To search for glucocerebrosidase mutations in Parkinson\'s disease patients in Brazil, followed at the Movement Disorders Division at Hospital das Clínicas, University of São Paulo Medical School, and correlate these findings with recently published studies which evaluated this association in other populations worldwide, besides describing possible features of patients carrying the mutations that may help differentiating them from non-carriers. Methods: Sixty five patients diagnosed with Parkinsons disease, with disease onset before age 55, and 267 age and sex-matched controls were included in the study. DNA analysis of the three most common glucocerebrosidase mutations in the Brazilian population, N370S, L444P and G377S, was performed utilizing samples obtained from mouth mucus. Results: Glucocerebrosidase gene mutations were identified in two of the 65 Parkinson\'s disease patients and in none of the 267 controls. The two patients who were carriers of mutations (one of them had L444P and the other L444P+E326K) had a clinical picture indistinguishable from the other Parkinson\'s disease non-carriers patients. Conclusion: A statistically significant association (P=0,0379, Fisher\'s exact test) between Parkinson\'s disease and glucocerebrosidase mutations was observed in our population. The prevalence of glucocerebrosidase mutations was higher than expected for the general population, though lower than reported in previous international studies. It is expected that the finding of this association will allow a better understanding of Parkinson\'s disease mechanisms and that in a near future it may help providing the development of new therapeutic strategies
Taxonomic revision of Gentianaceae in New Jersey
No full textChapter 1: Identification and Descriptions of Gentianaceae in New Jersey New Jersey holds unique ecological implications for the flora of North America, containing habitats from the coastal zone to the inland highlands, and as a transition zone between the more boreal and austral zones to the north and south, respectively. Presented here are identification keys and descriptions to the genera and species of Gentianaceae (Asteridae: Gentianales) that are native to or naturalized in the state of New Jersey, USA. This information will be used by the Flora of New Jersey Project, a collaboration among botanists to provide modern nomenclature, identification, description, distribution, abundance, and phenology data for all vascular plant species occurring naturally within the state. Keys to all genera and species are included, along with descriptions of morphological, ecological, distributional, and conservation information. These data were gathered from more than 1,650 herbarium specimens at The New York Botanical Garden (NY), Brooklyn Botanic Garden (BKL), the Academy of Natural Sciences of Philadelphia (PH), and the Chrysler Herbarium of Rutgers University (CHRB). In total, eight genera and 19 species were treated, and Schenkia spicata (L.) G. Mans. Is a new species and genus record for the state. Chapter 2: Nomenclature and Taxonomy of Gentianaceae in New Jersey Presented here are complete generic and specific nomenclature, typifications, and taxonomic updates on all of the species of Gentianceae (Asterids: Gentianales) occurring naturally in the state of New Jersey, USA. Complete synonymy is provided, along with all known information on typification. The gentianaceous species found in New Jersey include two Bartonia species, one Centaurium, seven Gentiana species, one Gentianella, one Gentianopsis, one Obolaria, five Sabatia species, and one Schenkia species. A clarification on the typification of Centaurium pulchellum (Sw.) Hayek ex Hand.-Mazz. et al. is provided, as well as neotype designations for Gentiana clausa Raf. and Gentiana linearis Froel., and a lectotypification for Sabatia stellaris Pursh.M.S.Includes bibliographical referencesby Lauren D. Spit
GUCY2D-Associated Retinopathy: A Comparative Study Between Humans and German Spitz Dogs
No full textThe anatomical and physiological similarities between human and canine eyes suggest that dogs may serve as a valuable model for studying retinopathies and developing future gene therapies. This study aims to evaluate the similarities and differences between humans with GUCY2D gene variants causing Leber’s congenital amaurosis (LCA) and a group of German Spitz dogs with hereditary retinopathy due to variants in the same gene, to assess their potential as an animal model for gene therapy research. A review of medical records, genetic testing, and ophthalmological examinations was conducted, including data such as age, genotyping, fundus photography, visual acuity (VA), fundus autofluorescence, optical coherence tomography (OCT), and electroretinography (ERG). Both groups presented subtle fundus abnormalities and severely reduced or absent ERG responses. In humans, OCT scans revealed decreased retinal thickness and structural alterations in the outer retinal layers. Similarly, the affected dogs exhibited focal neurosensory retinal detachments. The German Spitz model with GUCY2D variants shows significant parallels in retinal structure and functional impairment and may represent a promising candidate for preclinical gene therapy studies for LCA
Doença de Huntington e outras coreias
No full textCoreia se caracteriza por movimentos involuntários súbitos, breves, espontâneos, sem objetivo, contínuos, irregulares e imprevisíveis, que fluem de uma parte do corpo a outra. Pode ser manifestação de uma doença neurológica primária, como a doença de Huntington, ou pode ocorrer como complicação neurológica de condições sistêmicas. No Brasil, uma causa frequente, observada em crianças e adolescentes, é a coreia de Sydenham, decorrente de mecanismos imunes após infecção pelo estreptococo beta-hemolítico do grupo A e que é um dos critérios diagnósticos para febre reumática. A investigação de um paciente com coreia depende dos sintomas associados, presença de história familiar, idade de início, forma de instalação e progressão. O tratamento baseia-se nas medidas específicas para a doença subjacente, quando possível, e nos medicamentos sintomáticos, a serem administrados na dependência do impacto da coreia na qualidade de vida do paciente
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