A b s t r a c t : T h e p o t e n t i a l fo r m a l i g n a n t transformation of oral lichen planus is still controversial.The expression of proteins related to cell proliferation and apoptosis in oral lichen planus and epithelial dysplasia was analyzed to evaluate the true potential for malignant transformation of this disease. Twentyfour cases of each lesion were subjected to the streptoavidin-biotin technique for identifying the immunohistochemical expression of PCNA, p53, bax, and bcl-2 proteins. Of the 24 cases of oral lichen planus, 14 (58.33%) were positive for PCNA, 10 (41.67%) for p53, 4 (16.67%) for bcl-2 and 12 (50%) for bax, whereas of the 24 cases of epithelial dysplasia, 20 (83.33%) were positive for PCNA, 10 (41.67%) for p53, 6 (25%) for bcl-2, and 20 (83.33%) for bax. Chi-squared test showed no statistically significant differences between the expression of p53 and bcl-2 in oral lichen planus and epithelial dysplasia, regardless of the grade (P > 0.05). However, the expression of PCNA and bax was significantly increased in epithelial dysplasia (P < 0.05). The results of this study showed that alterations in expression of these proteins are observed in oral lichen planus and epithelial dysplasia, suggesting the potential for malignant transformation in both lesions. IntroductionOral lichen planus is a chronic inflammatory disease of unknown cause, and its potential for malignant transformation is a subject of much controversy (1). Since the first case was reported in 1910, several studies have suggested that patients with oral lichen planus are at an increased risk of developing cancer (1-7).However, many authors believe that there is insufficient data to prove an association between oral lichen planus and cancer. For these authors, most cases of malignant transformation are the result of errors in the initial diagnosis of the disease (1,8-13).The true potential for malignant transformation of oral lichen planus can be evaluated by analyzing the expression of proteins related to cell proliferation and apoptosis, as alterations in the expression of these proteins are essential for carcinogenesis (14)(15)(16)(17)(18)(19).Therefore, the aim of this study was to evaluate the immunohistochemical expression of PCNA, p53, bax and bcl-2 proteins in oral lichen planus and epithelial dysplasia in order to explain the controversy regarding the potential for malignant transformation of oral lichen planus and emphasize the importance of long-term follow-up of patients with this disease. Materials and MethodsThe samples used in this study consisted of 24 cases of oral lichen planus and 24 cases of epithelial dysplasia (4 mild, 12 moderate, 8 severe) obtained from the records of

No abstract

Resumen.-La variabilidad temporal de la densidad de la macrofauna y su relación con las propiedades del agua y sedimento fue estudiada a través de muestreos mensuales en una ensenada estuarina de la Laguna de los Patos, Brasil, de enero a diciembre de 2001. Las características del agua y del sedimento mostraron un nítido patrón estacional. Los mayores valores de salinidad y temperatura del agua se observaron en los meses de verano, mientras que un aumento de las fracciones finas en el sedimento ocurrió durante el invierno. Durante el estudio fueron recolectadas 18 especies, con un total de 38.827 organismos. El bivalvo Erodona mactroides, el tanaidaceo Kalliapseudes schübartii, los poliquetos Heteromastus similis y Nephtys fluviatilis y el gasterópodo Heleobia australis fueron los organismos dominantes, correspondiendo juntos, al 90% de la abundancia total. La macrofauna también mostró un patrón estacional de distribución, con las mayores densidades registradas durante los meses de verano (enero = 62.205 ind. m -2 ) y las menores en invierno (julio = 9.410 ind. m -2 ). Este patrón es resultante del proceso reproductivo de las especies, el cual comienza con el aumento de la temperatura a partir de fines de primavera. Las bajas densidades en el invierno están relacionadas con el efecto de una fuerte depredación sobre estos organismos asociada con la ausencia de reclutamientos efectivos en los meses fríos. Las alteraciones sedimentarias también pueden haber contribuido a la reducción de la densidad de la macrofauna durante el invierno.Palabras clave: Bentos, fondos blandos, estuario, Océano Atlántico suroesteAbstract.-Temporal variability of the macrofauna density and its relationship with water and sediments characteristics were studied through monthly sampling at an estuarine embayment of the Patos Lagoon, Brazil from January to December 2001. Both, water and sediments characteristics showed distinct seasonal patterns. High salinity and water temperature values were registered in summer months. Increase of fine fractions in the sediments occurred in cold months. A total of 38,827 individuals represented by 18 species were collected during the study period. The bivalve Erodona mactroides, the tanaid Kalliapseudes schübartii, the polychaetes Heteromastus similis and Nephtys fluviatilis, and the gastropod Heleobia australis were the dominant organisms, accounting for more than 90% of total macrofauna. The macrofauna also showed a seasonal pattern, with the highest density found in summer (January = 62, and the lowest one in winter (July = 9,410 ind. m -2 ). This pattern results from the species reproductive process, which was strongly correlated to the increase of water temperature at the end of spring. The low macrofauna densities in winter are related to a high predation during summer along with the absence of effective recruitment in cold months. Furthermore, sedimentary proprieties changes due to natural climatic disturbances could also be important factors controlling the estuarine macrofauna of the Patos Lagoo...

Sandy beaches constitute a key ecosystem and provide socioeconomic goods and services, thereby playing an important role in the maintenance of human populations and in biodiversity conservation. Despite the ecological and social importance of these ecosytems, Brazilian sandy beaches are significantly impacted by human interference, chemical and organic pollution and tourism, as well as global climate change. These factors drive the need to better understand the environmental change and its consequences for biota. To promote the implementation of integrated studies to detect the effects of regional and global environmental change on beaches and on other benthic habitats of the Brazilian coast, Brazilian marine researchers have established The Coastal Benthic Habitats Monitoring Network (ReBentos). In order to provide input for sample planning by ReBentos, we have conducted an intensive review of the studies conducted on Brazilian beaches and summarized the current knowledge about this environment. In this paper, we present the results of this review and describe the physical, biological and socioeconomics features of Brazilian beaches. We have used these results, our personal experience and worldwide literature to identify research projects that should be prioritized in the assessment of regional and global change on Brazilian sandy beaches. We trust that this paper will provide insights for future studies and represent a significant step towards the conservation of Brazilian beaches and their biodiversity.

http://www.medicinaoral.com/medoralfree01/v14i11/medoralv14i11p563.pdf AbstractBackground: Although oral lichen planus has been classified by the World Health Organization (WHO) as a potentially malignant disorder, such classification is still the target of much controversy. Aim: To evaluate the cell proliferation rate in oral lichen planus, comparing it to the rate observed in epithelial dysplasia and oral squamous cell carcinoma, aiming at indications which might indicate the potential for malignant transformation . Material and Methods: Twenty-four cases of each lesion were submitted to the streptoavidin-biotin and AgNOR technique to evaluate the immunohistochemical expression of PCNA and the mean NORs/nucleus, respectively. Results: Positivity for PCNA was observed in 58.33% of oral lichen planus cases, 83.33% of epithelial dysplasia cases and 91.67% of oral squamous cell carcinoma cases. Chi-squared test showed that the number of positive cases for PCNA was significantly lower in oral lichen planus than in oral squamous cell carcinoma (p<0.05). No significant statistical difference between oral lichen planus and epithelial dysplasia (p>0.05) and between the epithelial dysplasia and oral squamous cell carcinoma (p>0.05) was observed. The mean NORs/nucleus in oral lichen planus, epithelial dysplasia and oral squamous cell carcinoma were 1.74±0.32, 2.42±0.62 e 2.41±0.61, respectively. Variance analysis (ANOVA) revealed significant statistical difference between oral lichen planus and the other studied lesions (p<0.05). Conclusion: Oral lichen planus cell proliferation rate was less than in oral epithelial dysplasia and oral squamous cell carcinoma which might explain the lower malignant transformation rate.

No abstract

No abstract

This study examines the spatial distribution of the ghost crabs, Ocypode quadrata Fabricius, 1787, in thirteen estuarine sandy beaches located along two main axes of the Paranaguá Bay Estuarine Complex, southern Brazil. Burrow densities of ghost crabs were measured at three beach levels established around the high tide mark during the summer and winter of 2005. All beaches showed a steep beach face slope (2.6 to 8.3º) with sediment composition varying from well sorted fine sand to very poorly sorted coarse sand towards the upper estuary. Water salinity ranged from around 31 at those beaches near the bay inlet, to 14 at beaches in the inner estuary. The burrow densities of O. quadrata in the estuarine beaches were similar to those observed in the oceanic beaches. However, the absence of burrows at the four innermost beaches suggests that low salinity and sediment penetrability may prevent ghost crabs from occurring in this region of the estuary. Burrow densities showed strong seasonal variability. The low densities observed during the winter are probably related to a delay crab activities due to low temperatures in the early morning during this season. The absence of a clear zonation pattern was related to estuarine beach morphology.