36 research outputs found

    Immunohistochemical expression of EGFR in oral leukoplakia : association with clinicopathological features and cellular proliferation

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    Objectives: to investigate the immunoexpression of epidermal growth factor receptor (EGFR) in a sample of oral leukoplakias (OL) and to determine the receptor?s association with dysplasia, tobacco consumption, lesion site, and proliferation rate. Although EGFR should be overexpressed in some oral leukoplakias, the factors that may interfere with this expression and the influence of this receptor on epithelial proliferation have yet to be investigated. Study Design: Samples of oral leukoplakias (48) and of normal oral epithelium (10) were immunohistologically examined for expression of EGFR. Immunohistochemistry for Ki-67, and p27 were also performed in leukoplakias. EGFR expression was associated with clinical and pathological features. Results: EGFR was positive in 62.5% of the leukoplakias and 50% of normal oral epithelium. The number of EGFR positive OL located in high-risk sites was significantly higher than EGFR positive OL located in low-risk sites. Most of the p27 negative leukoplakias were EGFR positive, and the p27 index in the parabasal layer was diminished in the presence of dysplasia. Positivity for EGFR was not associated with dysplasia, tobacco exposure, or Ki-67. Conclusion: EGFR is expressed in leukoplakia regardless of dysplasia, but EGFR positivity should be more frequent in lesions sited in areas of high cancer risk. The association between EGFR and p27 may represent an important mechanism in the control of cellular proliferation and malignant progression of oral epithelium and therefore warrants further investigation

    The importance of Cone-Beam computed tomography in diagnosis of associated mandibular osteonecrosis: case report / A importância da TCFC no diagnóstico e prognóstico da osteonecrose mandibular associada aos bisfosfonatos: relato de caso clínico

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    The Cone-Beam Computed Tomography (CBCT) is very useful in diagnosis and treatment planning, as well as in the prognosis of osteonecrosis of the jaws. This study reports a clinical case of Bisphosphonate-Associated Mandibular Osteonecrosis from the perspective of CBCT. The patient, female, 83 years old, presented painful symptoms in the posterior region of the right mandible and reported Bisphosphonate medication for more than five years to treat osteoporosis and osteopenia. Based on clinical and CBCT imaging characteristics, the patient was diagnosed with Bisphosphonate-Associated Mandibular Osteonecrosis. Initially, the treatment consisted of oral antibiotic therapy, pain control, hyperbaric oxygenation and oral hygiene (mouthwashes). After 11 months of clinical therapy, CBCT revealed bone reconstruction of the buccal cortex, but also a hypodense imaging in the lingual cortex compatible with bone lysis and bone sequestration. The patient was referred for bone debridement and sequestrectomy. The histopathological diagnosis consisted of osteonecrosis with secondary acute osteomyelitis. After 60 days of the surgical procedure and hyperbaric sessions/systemic antibiotic therapy, an oral healthy mucosa in the region of the right mandibular body was evidenced in the intraoral examination. Cortical bone regeneration was observed on CBCT. Concluded that the use of CBCT, in this case report, makes it possible to estimate the extent of the lesion and the post-treatment outcome, assessing bone density, the presence of bone sequestration and the involvement of the involved areas. In fact, early diagnosis is essential for the success of the therapeutic approach

    Pervasive gaps in Amazonian ecological research

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    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

    Pervasive gaps in Amazonian ecological research

    Get PDF

    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding 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,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 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 underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities 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 organism 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 neglected 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 lost

    Síndrome da ardência bucal: uma revisão sobre aspectos clínicos, etiopatogenia e manejamento

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    El síndrome de boca ardiente (SBA) es una enfermedad crónica que se caracteriza por una sensación de quemazón de la mucosa bucal, que impresiona clínicamente normal. Es una entidad nosológica frecuente, sin embargo, los mecanismos implicados en su desarrollo en la actualidad son poco conocidos. El objetivo de este trabajo fue llevar a cabo una revisión de la literatura sobre dicho síndrome y se hizo énfasis en sus principales factores etiológicos y en el tratamiento de esta enfermedad. El SBA es una afección multifactorial compleja, debido a la diversidad de sus síntomas, dificultad en el tratamiento y las características psicológicas particulares de los pacientes. El diagnóstico correcto es el elemento principal para establecer el tratamiento. Es necesario realizar nuevas investigaciones para aclarar con precisión las causas del SAB, especialmente en la forma primaria
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