Elucidating the role of oxidative stress in the therapeutic effect of rutin on experimental acute pancreatitis.

INTRODUCTION: Acute pancreatitis (AP) may be severe and cause hospitalization or death, and the available treatment is insufficient to control pancreatic inflammation and pain. Rutin is a natural flavonoid with the potential to treat AP via anti-inflammatory, antinociceptive, and antioxidant activities. AIM: This study investigated the beneficial effects of rutin on experimental AP induced by l-arginine administration in mice. METHODS: The l-arginine-induced AP model was used in Swiss mice (n = 6-8). Mice submitted to AP induction were treated with rutin (37.5, 75, or 150 mg kg-1, p.o.) or vehicle (saline) after 24, 36, 48, and 60 h of AP induction. Abdominal hyperalgesia, serum enzymes, interleukin (IL)-6 levels, pancreatic inflammatory parameters, malondialdehyde (MDA) levels, antioxidant enzyme activities, and 3-nitrotyrosine contents were measured 72 h after induction. RESULTS: Mice submitted to l-arginine injections developed abdominal hyperalgesia and increased serum amylase, lipase, C-reactive protein and IL-6 concentrations; and increased pancreatic myeloperoxidase activity, edema index, MDA, and 3-nitrotyrosine contents. A marked decrease in catalase activity was observed in the pancreas without alterations of superoxide dismutase (SOD) activity compared with the control group. Rutin treatment significantly impaired all the parameters that were altered by AP induction, but increased catalase and SOD activities in the pancreas compared with the vehicle-treated group. CONCLUSION: Rutin treatment exerted a protective effect on l-arginine-induced AP by mechanisms involving the reduction of oxidative stress, which suggests that this flavonoid has a potential for future approaches designed for the management of AP.

Immunohistochemical staining of Langerhans cells in HPV-positive and HPV-negative cases of oral squamous cells carcinoma

The Human Papillomavirus (HPV) has been strongly implicated in development of some cases of oral squamous cell carcinoma (OSCC). However, the immunological system somehow reacts against the presence of this virus. Among the cells involved in such mechanism of defense Langerhans cells (LC) stand out, which are responsible for processing and presenting antigens. OBJECTIVES: The purposes of this study were to investigate the presence of HPV DNA and to evaluate the immunohistochemical reactivity for Langerhans cells between HPV-positive and HPV-negative OSCC. Twenty-seven cases of OSSC were evaluated. MATERIAL AND METHODS: DNA was extracted from paraffin-embedded tissue samples and amplified by Polymerase Chain Reaction (PCR) for the detection of HPV DNA. Viral typing was performed by dot blot hybridization. Immunohistochemistry was performed by the Streptavidin-biotin technique. RESULTS: From the 27 cases, 9 (33.3 percent) were HPV-positive and 18 (66.0 percent) HPV-negative. HPV 18 was the most prevalent viral type (100 percent cases) and infection with HPV-16 (co-infection) was detected in only 1 case. In the OSCC specimens examined, immunoreactivity to S-100 antibody was detected in all cases, with a mean number of 49.48±30.89 Langerhans cells positive for immunostaining. The mean number of immunostained Langerhans cells was smaller in the HPV-positive cases (38 cells/case) than in the HPV-negative cases (42.5 cells/case), but this difference was not significant (p=0.38). CONCLUSIONS: The low frequency of detection of HPV DNA in OSCC indicates a possible participation of the virus in the development and progression of only a subgroup of these tumors. There was no association between the immunohistochemical labeling for Langerhans cells (S-100+) and HPV infection of in OSSC. These findings suggest that the presence of HPV in such OSCC cases could not alter the immunological system, particularly the Langerhans cells.

Immunohistochemical staining of Langerhans cells in HPV-positive and HPV-negative cases of oral squamous cells carcinoma.

UNLABELLED: The Human Papillomavirus (HPV) has been strongly implicated in development of some cases of oral squamous cell carcinoma (OSCC). However, the immunological system somehow reacts against the presence of this virus. Among the cells involved in such mechanism of defense Langerhans cells (LC) stand out, which are responsible for processing and presenting antigens. OBJECTIVES: The purposes of this study were to investigate the presence of HPV DNA and to evaluate the immunohistochemical reactivity for Langerhans cells between HPV-positive and HPV-negative OSCC. Twenty-seven cases of OSSC were evaluated. MATERIAL AND METHODS: DNA was extracted from paraffin-embedded tissue samples and amplified by Polymerase Chain Reaction (PCR) for the detection of HPV DNA. Viral typing was performed by dot blot hybridization. Immunohistochemistry was performed by the Streptavidin-biotin technique. RESULTS: From the 27 cases, 9 (33.3%) were HPV-positive and 18 (66.0%) HPV-negative. HPV 18 was the most prevalent viral type (100% cases) and infection with HPV-16 (co-infection) was detected in only 1 case. In the OSCC specimens examined, immunoreactivity to S-100 antibody was detected in all cases, with a mean number of 49.48±30.89 Langerhans cells positive for immunostaining. The mean number of immunostained Langerhans cells was smaller in the HPV-positive cases (38 cells/case) than in the HPV-negative cases (42.5 cells/case), but this difference was not significant (p=0.38). CONCLUSIONS: The low frequency of detection of HPV DNA in OSCC indicates a possible participation of the virus in the development and progression of only a subgroup of these tumors. There was no association between the immunohistochemical labeling for Langerhans cells (S-100+) and HPV infection of in OSSC. These findings suggest that the presence of HPV in such OSCC cases could not alter the immunological system, particularly the Langerhans cells.

Role of inflammation in oral carcinogenesis (Part I): Histological grading of malignancy using a binary system.

The aim of the present study was to assess the suppressant role of the inflammatory infiltrate in oral carcinogenesis through the immunohistochemical expression of CD8 and FOXP3 and to discuss how representative this expression proved, as well as other parameters considered to be of prognostic value. A total of 20 cases of oral epithelial dysplasia and 40 cases of oral squamous cell carcinoma were selected. The criteria suggested by the World Health Organization were used for the histological grading of dysplasia. For carcinoma, a binary method was developed for the present study using parameters such as type of invasion, maturity, presence of epithelial masses and dysmorphism of the masses. Immunohistochemical analysis was performed for assessment of the expression of anti-CD8 and anti-FOXP3 in cases of dysplasia and carcinoma. Although the inflammatory infiltrate was more intense in the majority of carcinomas, it exercised a protective role in the dysplasia cases, as CD8 expression was significantly greater. Although a correlation was found between CD8 and the intensity of the inflammatory infiltrate in the carcinoma cases, CD8 demonstrated >5% expression in only 32.5% of the cases, compared to 80% of the dysplasia cases. Thus, we suggest that the inflammatory infiltrate should not be used as a parameter in routine examinations, as it plays different roles in the various stages of carcinogenesis. The histological grading system for malignancy employed in the present study is indicated for the assessment of oral squamous cell carcinoma.

High-risk human papillomavirus (HPV) is not associated with p53 and bcl-2 expression in oral squamous cell carcinomas.

OBJECTIVE: To determine the frequency and type of human papillomavirus (HPV) in oral squamous cell carcinomas (OSCC), as well as to identify a possible association between HPV infection and the expression pattern of p53 and bcl-2, and identify whether the oral HPV infection is a characteristic finding in our sample. METHODS: We performed polymerase chain reaction and dot blot hybridization for the detection of HPV DNA in paraffin sections as well as immunohistochemical analysis of p53 and bcl-2 in our sample. RESULTS: Twenty-six cases (29.5%) were positive for the virus by PCR. Dot blot hybridization identified HPV 18 in 21 (80.8%) cases, HPV 16 in one (3.8%) case and a combination of the two types in the four (15.4%) remaining cases. No other type of HPV was detected in the sample. Immunohistochemistry showed p53 in 26 (60.4%) cases and bcl-2 in 17 (39.5%) ones. No significant association was observed between the presence of HPV and the expression of the proteins studied (p=0.988 and p=0.748, respectively). CONCLUSIONS: Although this investigation have detected only 29.5% of HR-HPV DNA in OSCC, it is possible that this virus contribute to the development of some case of this tumor. Furthermore, it seems that the immunohistochemical expression of p53 and bcl-2 and the presence of HPV DNA are independent events in OSCC.

Detection of HPV DNA and immunohistochemical expression of cell cycle proteins in oral carcinoma in a population of Brazilian patients.

This study investigated the presence of human papillomavirus (HPV) DNA and viral types in 33 cases of oral squamous cells carcinoma (OSCC) and compared the immunohistochemical expression of the cell-cycle markers p21 and pRb between cases of the disease with and without HPV. DNA was extracted from paraffin-embedded tissue and amplified by PCR for the detection of HPV DNA. Viral typing was performed by dot blot hybridization. Immunohistochemistry was performed by the streptavidinbiotin technique. HPV DNA was detected in 11 (33.33%) of the 33 cases. The prevalent viral type was HPV 18 (81.81%). A significant association was observed between the presence of HPV and immunohistochemical expression of pRb, but not between p21 expression and the presence of the virus. The low frequency of detection of HPV DNA in OSCC suggests a possible participation of the virus in the development and progression of only a subgroup of these tumors.

Detection of HPV DNA and immunohistochemical expression of cell cycle proteins in oral carcinoma in a population of brazilian patients

This study investigated the presence of human papillomavirus (HPV) DNA and viral types in 33 cases of oral squamous cells carcinoma (OSCC) and compared the immunohistochemical expression of the cell-cycle markers p21 and pRb between cases of the disease with and without HPV. DNA was extracted from paraffin-embedded tissue and amplified by PCR for the detection of HPV DNA. Viral typing was performed by dot blot hybridization. Immunohistochemistry was performed by the streptavidinbiotin technique. HPV DNA was detected in 11 (33.33 percent) of the 33 cases. The prevalent viral type was HPV 18 (81.81 percent). A significant association was observed between the presence of HPV and immunohistochemical expression of pRb, but not between p21 expression and the presence of the virus. The low frequency of detection of HPV DNA in OSCC suggests a possible participation of the virus in the development and progression of only a subgroup of these tumors.

Inmunohistochemical expression of PCNA, p53 and bcl-2 in pleomorphic adenomas / Expresión inmunohistoquímica de PCNA, p53 y bcl-2 en adenomas pleomórficos

The aim of the study was to determine the immunohistochemical expression of the PCNA, p53 and bcl-2 proteins in pleomorphic adenomas. Nineteen specimens of pleomorphic adenomas were selected for analysis by the streptavidin-biotin-peroxidase method with antibodies againstp53, PCNA and bcl-2 proteins. It was observed weak labeling for p53 in 12 cases (63.1 percent) andforPCNA in 8 (42.1 percent). With respect to the bcl-2 labeling index, o no expression of this protein was detected in 12 cases, corresponding to 63.1 percent of the sample. Based on these findings, it was concluded that p53 and PCNA can favour the proliferative activity of pleomorphic adenomas, whereas bcl-2 probably does not effectively participate in the pathogenesis of this tumor.

El objetivo del estudio fue determinar la expresión inmmunohistoquímica de las proteínas PCNA, p53 y bcl-2 en adenomas pleomórficos. Fueron seleccionados 19 especímenes de adenomas pleomórficos para análisis a través del método de la estreptavidina-biotina-peroxidasa con anticuerpos contra las proteínas p53, PCNA y bcl-2. Fue observada leve marcación para p53 en 12 casos (63,1 por ciento) y para PCNA en 8 (42,1 por ciento). Con relación al índice de marcación para bcl-2, ono fue detectada en 12 casos (63,1 por ciento) expresión de esta proteína. En base a los resultados, se concluyó que las proteínas p53 y PCNA pueden favorecer la actividad proliferativa de adenomas pleomórficos, y por otro lado, la bcl-2 probablemente ono participaría efectivamente de la patogenia de este tumor.

Human papillomavirus in oral squamous cells carcinoma in a population of 75 Brazilian patients.

PURPOSE: In the present study, we investigated the presence of human papillomavirus (HPV) DNA and viral types in 75 cases of oral squamous cells carcinoma from Brazil to obtain data that would contribute to a better understanding of the role of HPV in the pathogenesis of this tumor. MATERIALS AND METHODS: DNA was extracted from paraffin-embedded tissue and amplified by polymerase chain reaction using a pair of primers designated PCO3+ and PCO4+ for the detection of a fragment of the human beta-globin gene, followed by polymerase chain reaction for the detection of HPV DNA using a pair of generic primers, GP5+ and GP6+. Viral typing was performed by dot blot hybridization. RESULTS: Human papillomavirus DNA was detected in 18 (24%) of the 75 cases positive for the human beta-globin gene. No significant association was observed between HPV and age, sex, or anatomical location of the tumor. The most prevalent viral type was HPV-18 (77,8%). CONCLUSION: The low frequency of detection of HPV DNA in oral epidermoid carcinomas suggests a possible participation of the virus in the development and progression of only a subgroup of these tumors.

Lesões verrucosas orais: papiloma, verruga vulgar e carcinoma verrucoso oral: estudo epidemiológico de 77 casos e avaliação histológica / Oral verrucous lesions

Neste estudo realizou-se um levantamento epidemiológico de 77 casos de lesões papilíferas da mucosa oral envolvendo 63 papilomas, 06 verrugas vulgares orais e 08 carcinomas verrucosos diagnosticados no serviço de Patologia Oral do Departamento de Odontologia da UFRN. Aspectos morfológicos relacionados na literatura como importantes indicadores de infecção por HPV também foram analisados em algumas lesões. Verificou-se que o papiloma oral foi a lesão mais freqüente, com uma ligeira predileção pelo gênero feminino, sendo a raça branca mais acometida e o palato a localização preferencial. A faixa etária de maior ocorrência foi a 1ª década de vida e maioria das lesões eram pediculadas. Quanto às demais lesões, a raça mais atingida também foi a branca e tanto nos casos de verruga vulgar como nos de carcinoma verrucoso, predominou a implantação do tipo séssil. O carcinoma verrucoso ocorreu principalmente na 6ª década de vida assim como no gênero masculino, não havendo predileção por um sítio de localização específico. Entretanto, a verruga vulgar oral foi mais freqüente na 1ª década de vida, ocorrendo preferencialmente no lábio inferior. Nos três tipos de lesões investigadas observou-se que alguns aspectos morfológicos relacionados ao HPV estavam presentes na maioria dos casos, indicando uma provável infecção pelo vírus nestas lesões

Estudo da detecção do DNA do papiloma vírus humano (HPV) e da expressão imuno-histoquímica de proteína do ciclo celular no carcinoma epidermóide oral / Study of DNA detection of human papillomavirus (HPV) and immunohistochemical expression of cell cycle protein in oral squamous cell carcinoma

O carcinoma epidermóide oral é a neoplasia maligna mais freqüente da cavidade oral e o papilomavírus humano (HPV) parece ter um relevante papel na indução desta lesão. Neste trabalho investigou-se o DNA do HPV e tipos virais em 90 casos de carcinoma epidermóide oral (CEO). Realizou-se também uma análise comparativa entre os grupos de CEO com DNA do HPV e sem o DNA do vírus, empregando-se os marcadores do ciclo celular p2l e pRb, a fim de estabelecer possível correlação entre a expressão imuno-histoquímica dessas proteínas e a infecção pelo HPV. O DNA foi extraído de tecido emblocado em parafina e amplificado por PCR (reação em cadeia da polimerase) com um par de primers designados PC03+ e PC04+ para um fragmento do gene da ~-globina humana. Posteriormente, realizou-se PCR para detecção do DNA de HPV utilizando-se um par de primers genéricos designados GP5+ e GP6+. A tipagem viral foi realizada pela hibridização dot blot. No método imuno-histoquímico utilizou-se a técnica da streptavidina-biotina com um painel de anticorpos monoclonais para as proteínas p2l e pRb. Dos 88 casos positivos para o gene da ~-globina humana, em 26 (29,5%) foi detectado o DNA do HPV. Não houve associação significativa entre o HPV e as variáveis idade e sexo dos pacientes e localização anatõmica da lesão. O tipo viral prevalente foi o HPV 18 (80,8%). Quanto à análise imuno-histoquímica, foi observada associação estatisticamente significativa entre a presença do HPV e a expressão imuno histoquímica de pRb (p=0,044), entretanto, não houve qualquer diferença estatisticamente significativa entre a expressão da proteína p2l e a presença do vírus (p =0,416). Pôde-se concluir que o baixo percentual de detecção do DNA do HPV no carcinoma epidermóide oral no presente trabalho, sugere uma possível participação do HPV no desenvolvimento e progressão de apenas um subgrupo dessas lesões.

Oral squamous cell carcinoma (OSCC) is the most common malignancy in oral cavity and human papillomavirus (HPV) may have an important role in its development. The aim of this experiment was to investigate the HPV DNA and viral types in 90 cases of OSCC. Moreover, a comparative analysis between the cases of OSSC with and without HPV DNA was performed by using cell cycle markers p21 and pRb in order to detect a possible correlation of these proteins and HPV infection. DNA was extracted from paraffin embedded tissue and amplified by PCR (polymerase chain reaction) with primers PCO3+ e PCO4+ for a fragment of human β-globin gene. After this procedure, PCR for HPV DNA detection was realized using a pair of generic primers GP5+ e GP6+. Immunohistochemical study was performed by streptoavidin-biotin technique and antibodies against p21 and pRb proteins were employed. Eighty-eight cases were positive for human β-globin gene and HPV DNA was found in 26 (29.5%) of then. It could not be detected significant correlation between HPV and age, sex and anatomical sites of the lesion. The most prevalent viral type was HPV 18 (80.8%). Regarding the immunohistochemical analysis, it was detected significant association between HPV presence and pRb immunoexpression (p=0,044), nevertheless, the same was not observed in relation to p21 protein (p =0,416). It can be concluded that the low detection of HPV DNA in OSCC by the present experiment suggests a possible role of the virus in the development and progression in just a subset of this disease.

Expressão imuno-histoquímica de proteínas da matriz extracelular em cistos odontogênicos calcificantes / Immunohistochemical expression of extracellular matrix proteins in calcifying odontogenic cyst

INTRODUÇAO: O cisto odontogênico calcificante (COC) é uma lesão odontogênica de natureza benigna considerada por alguns autores como uma lesão exclusivamente cística, enquanto outros admitem uma contraparte neoplásica benigna. Vários estudos têm pesquisado a natureza das células fantasmas características do COC, porém permanece obscuro o conhecimento sobre a expressão dos constituintes da matriz extracelular (MEC) nessa lesão. OBJETIVO: Realizar uma avaliação imuno-histoquímica da expressão de proteínas constituintes da MEC (fibronectina, tenascina e colágeno I) em espécimes de COCs, a fim de verificar se há diferenças significativas em tal expressão ou se esses padrões representam um espectro da mesma entidade. MATERIAL E MÉTODOS: Foram utilizados dez casos de COCs, representados por cinco do tipo unicístico simples, três do tipo produtor de odontoma e dois com proliferação ameloblastomatosa, que foram submetidos à técnica imuno-histoquímica da estreptoavidina-biotina com anticorpos monoclonais anti-fibronectina, anti-tenascina e anti-colágeno I. RESULTADOS: Verificou-se que houve uma expressão variável das proteínas pesquisadas, tanto entre as lesões do mesmo grupo, como entre os três grupos estudados, sendo notável a reatividade para os três anticorpos apresentada pelas células fantasmas. CONCLUSAO: Não foi possível observar um padrão de marcação que denotasse diferenças entre o tipo unicístico simples, o produtor de odontoma e o com proliferação ameloblastomatosa. Esse achado reforça a visão de que os vários tipos histológicos do COC podem, simplesmente, representar espectros histológicos diferentes de uma só entidade com comportamento biológico semelhante.

Aspectos morfológicos que sugerem a presença do papilomavírus humano (HPV) em lesões do epitélio de revestimento da mucosa oral / Suggestive morphological aspects of human papillomavirus (HPV) infection in epithelium oral mucosa lesions

O HPV é um vírus epiteliotrópico, cujo material genético é o DNA, e possivelmente associado a lesões benignas e malignas do epitélio de revestimento da mucosa oral. Os aspectos histomorfológicos encontrados na literatura relacionados a esse vírus são: coilocitose, disceratose, papilomatose, hiperceratose, acantose e grânulos de cerato-hialina proeminentes. Esses efeitos citopáticos quando encontrados em conjunto funcionam como um forte indicador de infecção por HPV. Dentre eles, a coilocitose se destaca por ser descrita freqüentemente como um sinal patognomônico de infecção por esse vírus. Este trabalho se propõe a revisar a literatura especializada sobre tais aspectos morfológicos na iniciativa de torná-los de uso rotineiro nos serviços de patologia oral como potentes indicadores de infecção por HPV