Salivary evaluation in radioactive I131 treated patients with thyroid carcinoma.

BACKGROUND AND OBJECTIVE: radioiodine treatment (I131) used to treat thyroid carcinomas produces side effects (sialadenitis, xerostomia, dysphagia and caries susceptibility) reflecting in a poor patient quality of life. This study aimed to evaluate the effect of I131 on salivary function and possible oral impairment. MATERIAL AND METHODS: Thirty-seven patients undergoing I131 were submitted to oral examination, answer questions regarding xerostomia/hyposalivation and collect saliva at three moments (M1: 30-45 days before I131, M2: 1-2 days after I131 and M3: 7-10 days after treatment). Saliva was assayed for flow rate and calcium/phosphate concentrations. RESULTS AND CONCLUSIONS: significant difference in calcium/phosphate concentration was shown between M1 and M2, with evident decrease at M2. Flow rate reduced right after treatment with 41% of patients returning to previous rate at M3 (no statistical difference). A higher number of patients related xerostomia and difficulty in swallowing food at M2. The results showed that xerostomia/hyposalivation, dysphagia and calcium/phosphate concentration decrease may be considered early radioiodine side effects.

DNA methylation in oral squamous cell carcinoma: from its role in carcinogenesis to potential inhibitor drugs.

DNA methylation is one of epigenetic changes most frequently studied nowadays, together with its relationship with oral carcinogenesis. A group of enzymes is responsible for methylation process, known as DNA methyltransferases (DNMT). Although essential during embryogenesis, DNA methylation pattern alterations, including global hypomethylation or gene promoter hypermethylation, can be respectively associated with chromosomal instability and tumor suppressor gene silencing. Higher expression of DNA methyltransferases is a common finding in oral cancer and may contribute to inactivation of important tumor suppressor genes, influencing development, progression, metastasis, and prognosis of the tumor. To control these alterations, inhibitor drugs have been developed as a way to regulate DNMT overexpression, and they are intended to be associated with ongoing chemo- and radiotherapy in oral cancer treatments. In this article, we aimed to highlight the current knowledge about DNA methylation in oral cancer, including main hyper/hypomethylated genes, DNMT expression and its inhibitor treatments.

Diagnostic Challenge and Clinical Management of Juvenile Mandibular Chronic Osteomyelitis.

Juvenile mandibular chronic osteomyelitis (JMCO) is a rare, idiopathic disease of chronic bone inflammation without suppuration, sinus tract formation, or sequestration. As the name suggests, this condition predominately affects children. The few cases of JMCO reported in the literature describe different treatments, and thus a standard therapy protocol has not yet been established. The aim of this paper is to report a clinical case in a 9-year-old girl that was misdiagnosed and unsuccessfully treated for 1 year. After experiencing persistent symptoms, a correct diagnosis was subsequently rendered based on the physical and radiographic examination as well as successful treatment with non-steroidal anti-inflammatory drugs (NSAIDs). The patient received drug therapy followed by periods of remission over a 4 year follow-up period. Diagnosis and treatment of JMCO is a challenge given the rarity and nonspecific signs and symptoms of this condition. Treatment with NSAIDs and regular follow-up is a conservative option for these patients.

Histone modifications: A review about the presence of this epigenetic phenomenon in carcinogenesis.

Among the epigenetic changes, histone acetylation has been recognized as a fundamental process that strongly affects gene expression regulation. Disrupt of this phenomenon has been linked to carcinogenesis. In this review, we analysed studies reporting the process of histone modification, the enzymes associated and affected genes concerning human malignancies and histone enzyme inhibitor drugs used in cancer treatment. Variable degrees of expression of HDACs (histone deacetylases) and HATs (histone acetyltransferases) are found in many human malignant tissues and the histones acetylation seems to influence different processes including the progression of cell cycle, the dynamics of chromosomes, DNA recombination, DNA repair and apoptosis. Thus, the control of aberrant activity and/or expression of these proteins have been favorable in treatment of diseases as cancer. HDACi have shown efficacy in clinical trials in solid and hematological malignancies. Therefore, the development and use of HDACs inhibitors are increasing, leading to continue studying these enzyme expressions and behavior, aiming to determine tumors that will respond better to this type of treatment.

Proliferative verrucous leukoplakia: diagnosis, management and current advances.

INTRODUCTION: Proliferative verrucous leukoplakia is a multifocal and progressive lesion of the oral mucosa, with unknown etiology, and commonly resistant to all therapy attempts with frequent recurrences. It is characterized by a high rate of oral squamous cell carcinoma and verrucou carcinoma transformations. OBJECTIVE: To analyze the studies about Proliferative verrucous leukoplakia and develop a concise update. METHODS: A Pubmed search identifying studies (laboratory research, case series and reviews of literature) that examined patients with Proliferative verrucous leukoplakia was realized. RESULTS: There are not enough studies about Proliferative verrucous leukoplakia in the literature. The few found studies not present a consensus about its etiology and diagnosis criteria. Although several treatment strategies have been proposed, most of them still show a high recurrence rate. CONCLUSION: More research about Proliferative verrucous leukoplakia is necessary to understand and treat this disease.

Utility of cell block in the cytological preoperative diagnosis of keratocystic odontogenic tumor.

In most cases involving jaw lesions, a biopsy and a histopathological analysis are necessary to establish the final diagnosis. However, biopsy may be a complex procedure at some maxillomandibular sites, and some systemic conditions could contraindicate the procedure. Thus, a search for new, less invasive techniques, which could eventually replace biopsy and simplify the diagnostic process, would benefit both professionals and patients. The aim of this study was to evaluate the cell block technique, prepared from the aspiration of luminal contents, in the preoperative diagnosis of keratocystic odontogenic tumors (KCOT). From 135 cases of lesions aspirated and processed by the cell block technique, we selected those containing keratin. In all cases selected, histological diagnosis was based on surgical biopsy. From 20 cases containing keratin in the cytological analyses, 19 were KCOTs and one was an orthokeratinized odontogenic cyst (OOC). In all KCOT cases, we observed the presence of parakeratin, even in those with intense inflammation. In the cytological analysis of the OOC, parakeratin was not observed. In conclusion, there is strong evidence that KCOT can be confidently diagnosed preoperatively by cytological analyses of lesions punctured and processed by the cell block technique.

Proliferative verrucous leukoplakia: diagnosis, management and current advances / Leucoplasia verrucosa proliferativa: diagnóstico, conduta e avanços atuais

Abstract Introduction: Proliferative verrucous leukoplakia is a multifocal and progressive lesion of the oral mucosa, with unknown etiology, and commonly resistant to all therapy attempts with frequent recurrences. It is characterized by a high rate of oral squamous cell carcinoma and verrucou carcinoma transformations. Objective: To analyze the studies about Proliferative verrucous leukoplakia and develop a concise update. Methods: A Pubmed search identifying studies (laboratory research, case series and reviews of literature) that examined patients with Proliferative verrucous leukoplakia was realized. Results: There are not enough studies about Proliferative verrucous leukoplakia in the literature. The few found studies not present a consensus about its etiology and diagnosis criteria. Although several treatment strategies have been proposed, most of them still show a high recurrence rate. Conclusion: More research about Proliferative verrucous leukoplakia is necessary to understand and treat this disease.

Resumo Introdução: Leucoplasia verrucosa proliferativa (LVP) é uma lesão multifocal e progressiva da mucosa oral, com etiologia desconhecida e comumente resistente a todas as tentativas terapêuticas, com recorrências frequentes. É caracterizada por uma alta taxa de transformação em carcinoma de células escamosas e carcinoma verrucoso da cavidade oral. Objetivo: Analisar os estudos sobre LVP e elaborar uma atualização resumida. Método: Foi realizada uma pesquisa na base de dados Pubmed que identificou estudos (pesquisas laboratoriais, séries de casos e revisões de literatura) que avaliaram pacientes com LVP. Resultados e discussão: Não há estudos suficientes sobre LVP na literatura. Os poucos estudos encontrados não apresentam consenso quanto aos critérios de etiologia e diagnóstico. Embora várias estratégias de tratamento tenham sido propostas, a maioria ainda apresenta alta taxa de recorrência. Conclusão: Mais pesquisas sobre LVP são necessárias para entender e tratar essa doença.

Salivary calcium and phosphate stability in different time and temperature storage

ABSTRACT The non-invasive collection and inexpensive nature of saliva has made it an attractive sample for use for diagnosis and research on several diseases. Storage circumstances may affect salivary component concentrations. The objective was to analyze calcium and phosphate stability in saliva samples stored at different conditions. Saliva of healthy people was stored and analyzed by spectrophotometry under different time and temperature conditions in order to evaluate calcium and phosphate stability. Calcium concentration was measured by Arsenazo III reaction at 600nm and phosphate by an acid-molybdate method at 650nm. Using Lin's concordance correlation coefficient (k), we observed very good agreement (k>0.8) for all samples frozen at -20 oC up to 50 days. Thaw/refreezing cycles can compromise phosphate stability even though there is good agreement (0.61<k<0.8). Because of higher variability for refrigerated samples, they are not the best storage method, although calcium and phosphate levels could be considered stable when the samples were stored at 4 oC for 7 days. Our results revealed that under different conditions, calcium and phosphate levels are stable in saliva samples, and that freezing at -20oC is the storage condition of choice, allowing to accumulate a higher number of samples before analysis, making it suitable for routine and research assays.

The role of epigenetic transcription repression and DNA methyltransferases in cancer.

Epigenetic alterations such as DNA methylation have been implicated in the development and progression of various cancers. DNA methylation consists of the reversible addition of a methyl group to the carbon 5 position of cytosine in CpG dinucleotides and is considered essential for normal embryonic development. However, global genomic hypomethylation and aberrant hypermethylation of regulatory regions of tumor suppressor genes have been associated with chromosomal instability and transcription repression, respectively, providing neoplastic cells with a selective advantage. DNA methyltransferases are the enzymes responsible for the addition of methyl groups to CpG dinucleotides, which, together with histone modifiers, initiate the events necessary for transcription repression to occur. It has been demonstrated that increased expression of DNA methyltransferases may contribute to tumor progression through methylation-mediated gene inactivation in various human cancers. Given their importance, this article reviews the main epigenetic mechanisms for regulating transcription and its implications in cancer development.

Immunohistochemical expression of DNA methyltransferases 1, 3a and 3b in oral leukoplakias and squamous cell carcinomas.

UNLABELLED: Over-expression of DNA methyltransferases DNMT1, DNMT3a and DNMT3b has been reported in various cancers and precancerous lesions. OBJECTIVE: To investigate DNMT1, DNMT3a and DNMT3b enzymes in oral squamous cell carcinoma (SCC) and leukoplakia, and their relationship with histopathologic/clinical parameters. STUDY DESIGN: Immunohistochemistry was carried out to evaluate the three DNMTs in 60 samples of oral SCC and 37 samples of oral leukoplakia. RESULTS: DNMT3a immunoreactivity in the three groups of oral SCC (39.8%) was significantly higher than in control (22.6%) (ANOVA, Student-Newman-Keuls test, P<0.05), but not when compared to oral leukoplakia groups (28.2%). For DNMT1 and DNMT3b, there were no statistically significant differences between oral SCC groups (65% and 74.7%), oral leukoplakia groups (68.3% and 70.9%) and control (65.4% and 76.5%). There was a significantly higher mean percentage of DNMT1 immunoreactivity in non-smokers (ANOVA, P=0.048), and a higher DNMT3a immunoreactivity in alcohol users (ANOVA, P=0.01). CONCLUSIONS: Higher DNMT3a immunopositivity may be associated with oral SCC and alcohol use, whilst lower levels of DNMT1 may be related with smoking habit. However, there was a significantly higher mean percentage of DNMT1 immunoreactivity in non-smokers (ANOVA, P=0.048), and a higher DNMT3a immunoreactivity in alcohol users (ANOVA, P=0.010).

Carcinoma de células escamosas em rebordo alveolar inferior: diagnóstico e tratamento odontológico de suporte / Squamous cell carcinoma in lower alveolar ridge: diagnosis and odontologic support treatment

O carcinoma epidermóide é a neoplasia maligna mais comum de cavidade oral e estruturas adjacentes. Apresenta maior incidência no gênero masculino, após a quarta década de vida, e tem como principais fatores etiológicos os usos crônicos de tabaco e álcool. Neste trabalho é relatado um caso de carcinoma de células escamosas do rebordo alveolar inferior, que não é uma região preferencial para esse tipo de patologia. Também é discutida a importância do cirurgião-dentista na equipe de profissionais que assiste esses pacientes, tanto no diagnóstico precoce quanto no manejo das alterações estomatológicas advindas da terapia antineoplásica.

Squamous cell carcinoma is the most common malignant neoplasm in oral cavity and adjacent structures. Its prevalence is higher in males, after the fourth decade, and the main etiologic associated factors are smoking and alcohol. This study reports a case of squamous cell carcinoma arising from the lower alveolar ridge, a non-preferential site for this pathology. It also discusses the importance of the dentist in the team of professionals assisting these patients, in early diagnosis and treatment of the stomatological alterations due to antineoplastic therapy.

Estudo da prevalência de alterações labiais em pescadores da ilha de Santa Catarina / Prevalence of lips pathologies in fishermen of Santa Catarina Island

São várias as alterações provocadas pela exposição labial continuada e desprotegidas à radiação ultravioleta, com destaque para a Queilite Actínica e o Carcinoma Epidermóide. O objetivo desta pesquisa foi levantar a prevalência de alterações labiais relacionadas à exposição crônica ao sol e estudar a sua relação com outros possíveis fatores etiológicos numa população de pescadores de Florianópolis/SC bem como os dispositivos e métodos de prevenção regularmente utilizados. De uma população de aproximadamente 4000 pescadores filiados a Federação de Pescadores do Estado de Santa Catarina, foram examinados 111 pescadores de 08 comunidades pesqueiras de Florianópolis, no período compreendido entre agosto de 2002 e março de 2003. Todos os participantes voluntßrios da amostra foram entrevistados e examinados em sedes ou associações das colônias de pescadores incluídas na amostra. As alterações labiais diagnosticadas no exame clínico foram registradas em ficha clínica própria. Dentre as patologias labiais diagnosticadas, destacaram-se 48 casos de queilite actínica, 2 casos de queilite actínica aguda, 3 de leucoplasia, 4 de hiperceratose e 4 suspeitas de Carcinoma Epidermóide. Foram realizadas 22 palestras educativas e distribuídos mais de 350 folhetos com orientações bßsicas sobre prevenção do câncer de boca; 16 pacientes foram encaminhados para o atendimento especializado no Ambulatório de Estomatologia do Hospital Universitßrio. O diagnóstico precoce de alterações labiais em pescadores, bem como a conscientização destes sobre os prejuízos da radiação ultra-violeta são fundamentais pelo fato dos mesmos pertencerem a uma população de risco ao desenvolvimento de lesões cancerizáveis e câncer de lábio.