36 research outputs found

    Stromal myofibroblasts in oral leukoplakia and oral squamous cell carcinoma

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    Objectives: Oral leukoplakia (OL) is the main potentially malignant disorder and oral squamous cell carcinoma (OSCC) is the most common malignancy of the oral mucosa. Stromal myofibroblasts play an important role in tumor invasion and metastasis, due to its ability to modify the extracellular matrix. This study aimed to evaluate the presence of stromal myofibroblasts in OL and OSCC. Differences in the presence of myofibroblasts among OL with distinct grades of epithelial dysplasia as well as between histologically high- and low-invasive OSCC were also assessed. Study D esign: A total of 30 OL and 41 OSCC from archival formalin-fixed, paraffin-embedded specimens were evaluated. 10 samples of normal oral mucosa were used as a control. Myofibroblasts were identified by immunohistochemical detection of alpha smooth muscle actin and its presence was classified as negative, scanty or abundant. Differences in the presence of myofibroblasts among OL with distinct grades of epithelial dysplasia as well as between high- and low-invasive OSCC were analyzed using the Mann-Whitney test. Results: Myofibroblasts were not detected in normal oral mucosa and OL, whatever its histological grade. In OSCC, the presence of stromal myofibroblasts was classified as negative in 11 (26.8%), scanty in 15 (36.6%), and abundant in 15 samples (36.6%). The presence of stromal myofibroblasts was statistically higher in high-invasive OSCC than in low-invasive OSCC (p<0.05). Conclusions: Stromal myofibroblasts were not detected in OL, indicating that these cells are not important during oral carcinogenesis. Nevertheless, stromal myofibroblasts were heterogeneously detected in OSCC and its presence was higher in tumors with a more diffuse histological pattern of invasion. These findings suggest that myofibroblasts are associated with the creation of a permissive environment for tumor invasion in OSC

    Expression of epithelial-mesenchymal transition markers at the invasive front of oral squamous cell carcinoma

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    Oral squamous cell carcinoma (OSCC) is one of the most common malignances. In epithelial-mesenchymal transition (EMT), epithelial cells switch to mesenchymal-like cells exhibiting high mobility. This migratory phenotype is significant during tumor invasion and metastasis. Objective : The aim of this study is to evaluate the expression of the EMT markers E-cadherin, N-cadherin and vimentin in OSCC. Material and Methods : Immunohistochemical detection of E-cadherin, N-cadherin and vimentin was performed on 20 OSCC samples. Differences in the expression of each protein at the invasive front (IF) and in the central/superficial areas (CSA) of the tumor were assessed. Differences in the expression of each protein at the IF of both histologically high- and low-invasive OSCCs were evaluated. Associations among expression of proteins at the IF were assessed. Correlations between the expression levels of each protein at the IF and the tumor stage and clinical nodal status were also evaluated. Results : Reduced expression of E-cadherin was detected in 15 samples (75%). E-cadherin expression was reduced at the IF when compared to the CSA and in high-invasive tumors when compared to low-invasive tumors. All samples were negative for N-cadherin, even though one sample showed an inconspicuous expression. Positive expression of vimentin was observed in 6 samples (30%). Nevertheless, there was no difference in vimentin expression between the IF and the CSA regions or between the low- and high-invasive tumors. Furthermore, no association was observed among protein expression levels at the IF. Finally, no correlations were observed between each protein’s expression levels and tumor stage or clinical nodal status. Conclusions : Reduced E-cadherin expression at the IF and its association with histological invasiveness suggest that this protein is a noteworthy EMT marker in OSCC. Although vimentin was also detected as an EMT marker, its expression was neither limited to the IF nor was it related to histological invasiveness

    Advanced osteosarcoma of the maxilla : a case report

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    Osteosarcomas are primary malignant bone tumours in which mesenchymal cells produce osteoid. It is generally the most common malignant bone neoplasm, although lesions of the jaw are uncommon. Osteosarcoma of the jaw (JOS) presents a lower incidence of metastasis and a better prognosis than osteosarcoma of the long bones. However, patients with JOS can exhibit advanced tumours, mainly when early diagnosis is not performed. This article reports on a case of an advanced osteosarcoma of the maxilla. A 38-year-old woman was referred for evaluation and treatment of recurrent fibrous dysplasia of the facial bones. The patient related that she had been diagnosed with fibrous dysplasia four years earlier and, since the first diagnosis, she was submitted to four surgical interventions, all followed by recurrences. The main clinical findings were redness and swelling of the facial skin, upper lip ulceration, and hard palate swelling. Computed tomography showed a large hyperdense mass in right maxilla extending to right orbit and left maxillary sinus. An incisional biopsy was performed and microscopic examination showed areas of osteoid and chondroid formation surrounded by a cellular stroma. The diagnosis of osteosarcoma was established and the patient was recommended for oncologic treatment. Unfortunately, she died six months after the diagnosis due to uncontrollable local spread

    Use of Surgical Laser for Excision of a Neurofibroma Associated With Neurofibromatosis Type-1

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    Introduction: Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder that affects approximately 1/3500 individuals. Various bone manifestations and peripheral nerves neoplastic lesions associated with NF1 are seen in the jaws. Several oral manifestations may occur in this disorder; therefore the dentist’s knowledge and multidisciplinary management of these patients are extremely important.Case Presentation: In the present article, we present the use of a high-power surgical laser to excise a neurofibroma in a patient with several intraoral manifestations associated with NF1.Conclusion: The use of diode laser (808 nm) for excision biopsy of tongue nodules showed no thermal damage to the tissue, allowing an adequate histopathological analysis of the neurofibrom

    Microvascular density and tumor budding in oral squamous cell carcinoma

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    Oral squamous cell carcinoma (OSCC) is the most prevalent malignant head and neck tumor, excluding the nonmelanoma skin cancer. Despite recent advances in the diagnosis and treatment, the disease's mortality rate is nonetheless high. The presence of isolated neoplastic cells or small clusters of up to four cells at the tumor?s invasive front, named tumor budding, is associated with a worse prognosis in OSCC. Angiogenesis has also been recognized as a determining factor in the progression of malignancies and in the development of metastases. Several studies have investigated the assessment of microvascular density (MVD) as a potential prognostic factor in OSCC. This study aimed to evaluate, in OSCC, differences in MVD between tumors with high-intensity tumor budding and tumors with low-intensity or no tumor budding. In samples with high-intensity tumor budding, differences in MVD between the budding area and the area outside the budding were also evaluated. Moreover, the study assessed differences in MVD concerning clinicopathological characteristics such as sex, age, tobacco smoking, tumor location and tumor size. One hundred and fifty [150] samples of OSCC were subjected to immunohistochemistry to assess the intensity of tumor budding (by immunostaining for multi-cytokeratin) and MVD (by immunostaining for CD34 and CD105, independently). The data were treated using descriptive and analytical statistics. There were no differences in MVD, assessed by immunostaining for CD34 or CD105, concerning clinicopathological characteristics such as sex, age, tobacco smoking, tumor location and tumor size (p > 0.05). Tumors with high-intensity tumor budding did not show differences in MVD, assessed by immunostaining for CD34 or CD105, when compared to tumors with low-intensity or no tumor budding (p > 0.05). However, in samples with high-intensity tumor budding, the MVD assessed by immunostaining for CD34 was higher in the budding area than in the area outside the budding (p 0.05). The higher MVD in the budding area may be an additional indication that this is a peculiar region of the tumor, associated with biological phenomena related to tumor progression

    Peripheral Calcifying Odontogenic Cyst : a rare case report

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    The Calcifying Odontogenic Cyst (COC) is a simple cyst lined by ameloblastoma-like epithelium with ghost cells. The peripheral COC is a rare lesion and few reports have been published considering its clinical and histopathological features. This article aimed to report on a case of a peripheral COC, discussing its clinical, imaginological and histopathological features. A 9-year-old male patient presented a 10x5 mm painless nodule in the palatal mucosa of the left central incisor. Panoramic, occlusal and periapical radiographs did not show alterations. A computed tomography exam showed a slight soft tissue swelling located in the palatal mucosa of the left maxillary central incisor. An excisional biopsy was performed. The histopathological analysis showed a cystic lesion adhered to an oral mucosa fragment and lined by an ameloblastoma-like epithelium with ghost cells. The diagnosis of peripheral COC was established and the patient has been disease-free for 5 years. Although rare, peripheral COC is an important lesion that should be considered as a differential diagnosis of gingival hyperplastic lesions

    Pesquisa Nacional de Saúde 2019: histórico, métodos e perspectivas

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    This article presents the history and construction of the National Health Survey (PNS) 2019, a household survey conducted in partnership with the Brazilian Institute of Geography and Statistics. The objective was to provide the country with information on the determinants, conditions and health needs of the Brazilian population. The expected sample was 108,525 households, considering a non-response rate of 20%. The questionnaire had three parts: (i) regarding the household; (ii) to all residents of the household, focusing on the collection of socioeconomic and health information; and (iii) aimed at the selected resident (15 years or more) for whom lifestyles, chronic diseases, violence, among other topics were investigated, and anthropometric measures (sub-sample) were measured. The PNS information will serve as a basis for the (re)formulation of health policies, as well as support for existing actions and programs of the Unified Health System.Este artigo apresenta o histórico e a construção da Pesquisa Nacional de Saúde (PNS) 2019, inquérito de base domiciliar realizado em parceria com a fundação Instituto Brasileiro de Geografia e Estatística. O objetivo da PNS 2019 foi dotar o país de informações sobre os determinantes, condicionantes e necessidades de saúde da população brasileira. A amostra prevista foi de 108.525 domicílios particulares, considerando-se uma taxa de não resposta de 20%. Seu questionário continha três partes, orientadas para (i) o domicílio, (ii) todos os moradores do domicílio, com enfoque na coleta de informações socioeconômicas e de saúde, e (iii) o morador selecionado (idade ≥15 anos), sobre o qual investigou-se estilos de vida, doenças crônicas, violências, entre outros temas, e aferiu-se medidas antropométricas (subamostra). As informações da PNS 2019 servirão de base para a (re)formulação de políticas de saúde e subsídio a ações e programas existentes do Sistema Único de Saúde

    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

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