HNK1 and Sox10 are present during repair of mandibular bone defects.

Neural crest cells possess characteristics of stem cells including plasticity and ability to differentiate into various cell types. HNK1 and Sox10 are markers of neural crest cell progenitors that have been demonstrated in osteoblasts during osteogenesis of the maxilla and mandible. We investigated the presence of Sox10 and HNK1 during regeneration of mandibular bone defects. Defects were created in mandibles of rats. Samples of these defects were collected at 7, 14 and 28 days post-surgery; bone regeneration was observed during this period. Immunohistochemical analysis revealed expression of HNK1 and Sox10 in osteoblasts, osteocytes and osteogenic cells, whereas osteoclasts were unstained. HNK1 expression was increased in osteoblasts and osteocytes over time and SOX10 expression was found in osteoblasts and osteogenic cells at 7, 14 and 28 days post-surgery. HNK1 and Sox10 are present in osteoblasts, osteocytes and osteogenic cells during mandible bone regeneration.

Immunoexpression of HDAC1, HDAC2, and HAT1 in actinic cheilitis and lip squamous cell carcinoma.

BACKGROUND: Acetylation and deacetylation are the most studied covalent histone modifications resulting in transcriptional regulation with histone deacetylases (HDAC) and histone acetyltransferases (HAT) as the main associated enzymes. These enzymes overexpression induces abnormal transcription of key genes that regulate important cellular functions, such as proliferation, cell cycle regulation, and apoptosis. Thus, the expression of different HATs and HDACs has been evaluated in various cancers. OBJECTIVE: To investigate HDAC1, HDAC2 and HAT1 expression in lip squamous cell carcinoma (LSCC) and actinic cheilitis (AC) and to demonstrate their correlation with DNA metyltransferases (DNMTs). MATERIAL AND METHODS: Thirty cases of lip squamous cell carcinoma (LSCC), thirty cases of actinic cheilitis (AC), and 28 cases of non-neoplastic epithelium as control were selected for immunohistochemical investigation. RESULTS: Nuclear HDAC2 immunopositivity was significantly higher in AC (75.07% ± 29.70) when compared with LSCC (51.06% ± 39.02). HDAC1 and HAT1 nuclear immunostaining were higher in AC, with no statistical significance. When comparing data with our previous study, we found a positive correlation between HDAC1 X DNMT1/DNMT3b, HDAC2 X DNMT3b, and HAT1 X DNMT1/DNMT3b for certain studied groups. CONCLUSION: This study showed higher levels of nuclear HDAC2 immunopositivity in AC, possibly indicating that this enzyme plays a key role in lip photocarcinogenesis early stages.

Histopathologic features in actinic cheilitis by the comparison of grading dysplasia systems.

OBJECTIVE: This study aimed to determine the histopathologic findings in actinic cheilitis (AC) and lip squamous cell carcinomas (LSCC) diagnosed at Federal University of Santa Catarina in order to attempt to predict the evolution from AC to LSCC based on the comparison of two dysplasia classification systems. METHODS: Histopathologic features were evaluated according to the World Health Organization classification of dysplasia and binary system of classification. Also, in LSCC, pattern, stage of invasion, and degree of keratinization were evaluated. A total of 58 cases of AC and 70 cases of LSCC were studied, and data correlation was performed using statistical analysis. RESULTS: The presence of dyskeratosis and keratin pearls was found to be strongly associated with severe dysplasia and could represent higher proximity between the severe dysplasia in AC and LSCC. Also, changes related to the nuclei, such as hyperchromasia, nuclear pleomorphism, anisonucleosis, increase in the number and size of nucleoli, increased number of mitoses, and atypical mitoses, indicate progression in dysplasia spectrum. CONCLUSION: Knowledge of clinical and histological features of AC and LSCC leads to better understanding of factors possibly associated with malignant transformation of epithelial dysplasia.

Paracoccidioidomicosis: Manifestaciones orales e implicaciones sistémicas / Paracoccidioidomicose: Oral manifestations and sistemic implications

La paracoccidioidomicosis es una infección causada por un hongo P. brasiliensis. Se trata de una micosis profunda y sistémica, es considerada una enfermedad endémica en Brasil y en otros países de América Latina. El hongo es adquirido por inhalación, dando lugar a un cuadro clínico pulmonar que puede posteriormente afectar a la piel, mucosa oral, nasal y gastrointestinal; también el bazo y el hígado pueden verse afectados. Es frecuente encontrar linfadenopatías, y verse afectada la glándula suprarrenal y todas las vísceras, causando la muerte del paciente. Las úlceras orales suelen ser lesiones muy dolorosas, por ello el paciente acude a consulta para ser evaluado clínicamente por su odontólogo o estomatólogo. El diagnóstico precoz es la mejor manera de salvar al paciente de las complicaciones de la enfermedad. El número creciente de inmigrantes latinos puede hacer que esta importante enfermedad empiece a ser más prevalente en los países de la Comunidad Europea, por ello conocer en profundidad las características clínicas de esta infección por parte de los odontólogos europeos, es fundamental para llegar a diagnosticarla de forma temprana (AU)

Paracoccidioidomycosis is an infection caused by the p. brasiliensis fungus. This is a deep, systemic fungal infection considered endemic in Brazil and some Latin American countries. The fungus is acquired by inhalation, resulting in a pulmonary disease which may also affect the skin, oral, nasal and gastrointestinal mucosa, as well as the spleen and liver. Patients commonly present lymphadenopathy. The resulting adrenal gland and visceralin volvement can be fatal. Oral lesions are often very painful leading the patient to the dentist or stomatologist for a clinical evaluation. Early diagnosis is the best way to avoid serious complications of the disease. The growing number of Latin immigrants may increase the prevalence of this important disease in the European Community, therefore, the knowledge of the clinical characteristics of this infection by European dentists isessential to early diagnosis (AU)

Expression of integrin subunits alpha2, alpha3, alpha5, alphav, beta1, beta3 and beta4 in different histological types of ameloblastoma compared with dental germ, dental lamina and adult lining epithelium.

OBJECTIVE: To analyze integrin expression and distribution in different histological types of ameloblastoma, compared with dental germ, dental lamina and adult lining epithelium. MATERIALS AND METHODS: Three-micrometer sections from paraffin-embedded specimens were evaluated employing a streptavidin-biotin immunohistochemical method and anti-integrin alpha2, alpha3, alpha5, alphav, beta1, beta3 and beta4 antibodies. RESULTS: All integrins were present in all specimens, exhibiting different patterns. In follicular ameloblastoma, the integrin staining was stronger in the periphery while integrin alpha2 was not present in the central cells. Acanthomatous ameloblastoma showed a similar pattern, with positive staining for integrins alpha3, alpha5, alphav, beta1 and beta4 in the metaplastic cells. In the unicystic, integrin staining was uniform except for integrins alpha5 and beta3 which showed weaker staining in the upper layers. In the plexiform ameloblastoma, dental germ and lamina integrin staining was uniform. In the adult lining epithelium, staining for integrins alpha2, alpha5 and beta4 was confined to the basal layer, while integrins alphav and beta3 were present in the basal and parabasal, with integrins alpha3 and beta1 in the upper layers. CONCLUSION: Acanthomatous, follicular and unicystic ameloblastomas showed integrin staining patterns similar to the adult lining epithelium while the plexiform ameloblastoma was similar to the dental germ and lamina.