Lymphocyte­derived microparticles stimulate osteoclastogenesis by inducing RANKL in fibroblasts of odontogenic keratocysts.

Leukocyte­derived microparticles (LMPs) include neutrophil­, lymphocyte­ and monocyte­derived MPs. LMPs act as proinflammatory mediators in autoimmune diseases, infectious diseases and vascular diseases. The present study examined the hypothesis that the percentage of LMPs was increased in patients with inflamed odontogenic keratocysts (OKCs), and investigated the biological effects of Jurkat cell­derived MPs on the fibroblasts of OKCs in vitro. Cyst fluid MPs, obtained by centrifugation of samples from 20 patients with inflamed OKCs, 3 patients with uninflamed OKCs, 15 patients with radicular cysts (RCs) and 12 patients with inflamed dentigerous cysts (DCs), were analyzed by transmission electron microscopy, dynamic light scattering and immunofluorescence staining. The percentages and concentrations of cyst fluid LMPs were further determined by flow cytometry. The cytokine levels of apoptotic Jurkat cell­derived MPs and Jurkat cell supernatants were compared by cytokine antibody arrays. Fibroblasts were isolated from 3 patients with OKC and co­cultured with apoptotic Jurkat cell­derived MPs with or without interleukin (IL)­15Rα to detect the levels of matrix metallopeptidase 9 (MMP­9) and receptor activator of nuclear factor­κB ligand (RANKL) by reverse transcription­quantitative polymerase chain reaction and enzyme­linked immunosorbent assay. The supernatant from Jurkat MPs­treated fibroblasts was collected to make conditioned medium in which the osteoclastogenesis of Raw264.7 cells was determined. Antibodies against human soluble (s)RANKL were added to the conditioned medium to investigate the inhibitory effects. Mean percentages of lymphocyte­ and neutrophil­derived MPs were significantly higher in inflamed OKCs than in DCs. Significant elevations in IL­15 were detected in apoptotic Jurkat cell­derived MPs compared with that in Jurkat cell supernatant. Furthermore, higher levels of MMP­9 and RANKL were detected in Jurkat cell MP­treated OKC fibroblasts, and this was partially blocked by IL­15Rα. Increased osteoclast­like cell formation was observed in the Jurkat MPs­treated fibroblast supernatant and Raw264.7 co­culture groups. The anti­human sRANKL antibody in the Jurkat MPs­treated fibroblast supernatant group decreased the osteoclastogenesis of the Raw264.7 cells. These results indicate that LMPs serve as novel communication tools that contribute toward the bone resorption of inflamed OKCs by inducing RANKL of OKC fibroblasts via IL­15.

Immunoexpression of proteins involved in cytoskeleton remodeling in benign odontogenic lesions.

OBJECTIVE: The present study was designed to analyze the immunolocalization of proteins involved in cytoskeleton remodeling, such as moesin and Rho-A, in benign odontogenic lesions that present with expansive growth and invasive clinical behavior. MATERIALS AND METHODS: Expressions of moesin and Rho-A in odontogenic epithelium were evaluated by immunohistochemical analysis in 45 odontogenic lesions using monoclonal antibodies. RESULTS: Our results demonstrated strong membranous and cytoplasmic expressions of moesin in the epithelial cells in 66.7% and 44.4% of the odontogenic lesions, respectively. Furthermore, Rho-A expression in odontogenic epithelium was strong in the membrane and cytoplasm of 51.1% and 62.2% of the odontogenic lesions, respectively. A statistically significant correlation was found between the membranous and cytoplasmic expressions of moesin (p = 0.000) and those of Rho-A (p = 0.048) in odontogenic epithelial cells, while no statistically significant correlation was found between moesin and Rho-A expressions (p > 0.05). CONCLUSIONS: The present study confirmed the strong expressions of moesin and Rho-A by odontogenic epithelial cells, suggesting their involvement in the development of benign odontogenic lesions. However, this study has failed to detect the connection between the moesin and Rho-A interaction in expansive growth and local invasiveness of these lesions.

Comparative immunoexpression of ICAM-1, TGF-Beta1 and ki-67 in periapical and residual cysts

BACKGROUND: This study compared the immunohistochemical expression of ki-67, transforming growth factor beta 1 (TGF-Beta 1) and intercellular adhesion molecule-1 (ICAM-1) in inflammatory periapical cysts and residual cysts. MATERIAL AND METHODS: The study sample was composed by 25 periapical cysts and 25 residual cysts and immunohistochemical reactions were carried out using antibodies directed against ICAM-1, TGF-β1 and ki- 67. Clinical, radiological, gross, histological and immunohistochemical data were tabulated for descriptive and comparative analysis using the SPSS software and differences were considered statistically significant when p < 0.05%. RESULTS: There were no differences between the expression of ICAM-1 (p = 0.239) and TGF-β1 (p = 0.258) when comparing both groups. Ki-67 labeling index was higher in residual cysts compared to periapical cysts (p = 0.017). CONCLUSIONS: Results from the present study suggest that some specific inflammatory stimuli on residual cysts would modulate their mechanisms of etiopathogenesis, growing and repair

Immunoexpression of tumour necrosis factor-α, interleukin-1α and interleukin-10 on odontogenic cysts and tumours.

AIM: To analyse the immunoreactivity of IL-1α, TNF-α and IL-10 in odontogenic cysts and tumours and to investigate possible associations with established biological behaviours of these different lesions. METHODOLOGY: Immunohistochemical expression of anti-IL-1α, anti-TNF-α and anti-IL-10 antibodies was assessed on epithelium and mesenchyme of 20 radicular cysts (RCs), 20 residual cysts (RECs), 20 dentigerous cysts (DCs), 18 solid ameloblastomas (SAs), 20 keratocystic odontogenic tumours (KCOTs) and 15 dental follicles (DFs). Comparative analysis of data was performed using the nonparametric Wilcoxon signed-rank test and Kruskal-Wallis's test. RESULTS: Significantly greater expression of IL-1α in the epithelium was noted in RC, KCOT and SA (P = 0.01), whilst IL-10 and TNF-α was in the epithelium of RC, DC and KCOT (P < 0.01). In the mesenchyme, significantly greater immunopositivity was observed for IL-1α, IL-10 and TNF-α in KCOT, DC and RC (P < 0.01). In epithelial and mesenchymal tissues, there were a significant number of cases of RC and DC with IL-1α < IL-10 ratio (P < 0.01), whilst SA and KCOT showed IL-1α > IL-10 (P < 0.01). There was a significantly greater percentage of DF, DC and KCOT with TNF-α > IL10 ratio (P < 0.01). CONCLUSION: These results suggest involvement of the proteins in the pathogenesis of odontogenic cysts and tumours, with emphasis on the highest immunoreactivity of osteolysis stimulating factors in tumours with aggressive biological behaviour, such as SA and KCOT.

Metallothionein immunoexpression in non-syndromic and syndromic keratocystic odontogenic tumour.

BACKGROUND: To compare the metallothionein (MT) immunoexpression in non-syndromic and syndromic keratocystic odontogenic tumour (KOT), to correlate MT with cellular proliferation, and to evaluate the influence of inflammation in MT. STUDY DESIGN: Fourteen cases of KOT were submitted to immunohistochemistry for MT and Ki-67 analysis. The lesions were grouped according to their grade of inflammation, and statistical analysis was performed. RESULTS: MT was higher in non-syndromic KOT than in syndromic KOT (p<0.05). No statistical difference in Ki-67 could be identified; however, an inverse correlation was observed between MT and Ki-67 in both lesions. When analysing inflammation, non-syndromic KOT showed no differences in either MT or Ki-67. CONCLUSIONS: The MT immunophenotype of syndromic KOT was different from non-syndromic KOT. MT might not be involved in the proliferation control of both KOT. MT and Ki-67 immunoexpressions proved to be unaffected by inflammation in non-syndromic KOT.

[THE ROLE OF IMMUNOLOGICAL CHANGES IN ODONTOGENIC CYSTS].

The study involved 67 patients with odontogenic cysts (OC) aged 18 to 45 years, who were divided into groups: Group 1 (n = 67) patients with OC aged 18 to 45 years, group 2--control group, consisted of 20 healthy persons of similar age. We studied the characteristics of immune status and immunoreactivity in patients with odontogenic cysts. Condition of cellular and humoral immunity was assessed by using the methods of direct rosette developing with erythrocytes coated with monoclonal antibodies to CD3+, CD4+, CD8+, CD22+, CD4/CD8 indicators of immunoregulatory index and phagocytic immunity. State of nonspecific resistance was studied by determining the phagocytic activity of neutrophils and their oxygen dependent metabolism in NBT test. The concentration of cytokines (IL-6 and IL-4) in serum was determined by ELISA. During the study we found that in patients with (OC) developed significant changes in the structure of the immune response at the cellular as well as at the humoral level that makes it necessary to develop new individualized preventive measures along with existing therapies OC.

Estudo da expressão imuno-histoquímica das proteínas MMP-9, MMP-13, e TIMP-1 em ameloblastomas e tumores odontogênicos ceratocistos / Study of immunohistochemical expression of MMP -9, MMP -13 protein, and TIMP - 1 in ameloblastomas and odontogenic keratocysts tumors

Os ameloblastomas e tumores odontogênicos ceratocísticos (TOC) representam lesões odontogênicas que, apesar de sua natureza benigna, se destacam por um comportamento biológico distinto, caracterizado pelo crescimento localmente agressivo e episódios recidivantes. A reabsorção dos ossos gnáticos provocada pelo crescimento dessas lesões constitui um fator determinante à expansão das mesmas, sendo mediada tanto por células osteoclásticas como pela ação enzimática de diversas metaloproteinases de matriz (MMPs). A expressão de fatores estimuladores e inibidores da reabsorção óssea vem sendo correlacionada com o desenvolvimento destas lesões, merecendo destaque algumas MMPs como as colagenases e as gelatinases e os inibidores teciduais de metaloproteinases (TIMPs), dentre outros. Baseados na premissa de que fatores estimuladores e inibidores de processos osteolíticos podem ser determinantes para o ritmo de crescimento de lesões odontogênicas intraósseas, o objetivo de estudo foi avaliar a imunoexpressão das proteínas MMP-9, -13 e TIMP-1 no epitélio e mesênquima de espécimes de ameloblastomas e TOC. A análise estatística foi realizada através dos testes de Mann-Whitney e Wilcoxon com nível de significância estabelecido em 5%. Através de uma análise quantitativa das células imunomarcadas, foi observada a expressão imuno-histoquímica das MMP-9, -13 e TIMP-1 em 100% dos casos, tanto no epitélio quanto no mesênquima tumoral. Mais de 76% das células epiteliais (escore 3) dos TOC e ameloblastomas apresentaram imunomarcação para MMP-9 (p=0,382) e MMP-13 (p=0,069), sendo estatisticamente significativa para o TIMP-1 (p=0,003) nos ameloblastomas. No mesênquima, observou-se maior escore de imunomarcação da MMP-13 (p=0,031) nos ameloblastomas em relação aos TOC, enquanto para a MMP-9 e TIMP-1 não se observou diferença estatisticamente significativa (p=0,403; p=1,000). O cálculo da razão entre os escores de expressão das proteínas revelou, de uma maneira geral, similaridade entre as lesões, sendo observado predomínio significante de igualdade de expressão do TIMP-1 e da MMP-9 apenas no epitélio dos ameloblastomas. A imunoexpressão marcante das MMP-9, MMP-13 e TIMP-1 no epitélio e mesênquima das lesões estudadas indica que estas proteínas participam na remodelação da MEC necessária à progressão tumoral, no entanto, as diferenças pontuais observadas na expressão de algumas destas proteínas, não são suficientes para sugerir diferenças no comportamento biológico dos ameloblastomas e dos TOCs. (AU)

Ameloblastomas and keratocystic odontogenic tumors (KOT) represent odontogenic lesions that, despite their benign nature, are distinguished by a distinct biological behavior, characterized by locally aggressive growth and recurrent episodes. The gnathic bone resorption caused by the growth of these lesions is a key to the expansion of the same, both being mediated by osteoclastic cells like enzymatic activity of various matrix metalloproteinases (MMPs) factor. The expression of stimulatory factors and inhibitors of bone resorption has been correlated with the development of these lesions, with emphasis to some MMPs such as collagenases and gelatinases and tissue inhibitors of metalloproteinases (TIMPs), among others. Based on the premise that stimulatory and inhibitory factors of osteolytic processes can be decisive for the growth rate of intraosseous odontogenic lesions, this experiment evaluated the immunoreactivity of MMP-9, -13 and TIMP-1 protein in the epithelium and mesenchyme of ameloblastoma and the KOT specimens, by a quantitative analysis of the immunoreactivity cells. Statistical analysis was performed using the MannWhitney and Wilcoxon tests with a significance level set at 5 %. Immunohistochemical expression of MMP-9, -13 and TIMP-1 was observed in 100% of cases both in the epithelium and in mesenchyme. The immunoreactivity in the epithelium of KOT and ameloblastomas revealed a predominance of score 3 for MMP-9 (p=0.382) and MMP-13 (p=0.069) and no statistically significance for TIMP-1, the latter being significantly higher immunoreactivity in ameloblastomas. In the mesenchyme, there was a higher score immunoreactivity of MMP-13 (p=0.031) in ameloblastomas in relation to KOT, whereas for MMP-9 and TIMP-1 no statistically significant difference (p=0.403 was observed, p=1.000). The calculation of the ratio of scores revealed expression of proteins in general, similarity of the lesions, a significant predominance of equal expression of TIMP-1 and MMP-9 was observed only in the epithelium of ameloblastoma. The marked immunostaining of MMP-9 , MMP-13 and TIMP-1 in epithelium and mesenchyme of the lesion indicate that these proteins involved in ECM remodeling required for tumor progression, however, specific differences in the expression of some of these proteins, are not sufficient to suggest differences in the biological behavior of ameloblastomas and KOTs. (AU)

The immunoprofile of odontogenic keratocyst (keratocystic odontogenic tumor) that includes expression of PTCH, SMO, GLI-1 and bcl-2 is similar to ameloblastoma but different from odontogenic cysts.

BACKGROUND: The aggressive biological behavior of odontogenic keratocysts (OKCs), unlike that of other odontogenic cysts, has argued for its recent re-classification as a neoplasm, 'keratocystic odontogenic tumor'. Identification of mutations in the PTCH gene in some of the OKCs that were expected to produce truncated proteins, resulting in loss of control of the cell cycle, provided additional support for OKCs having a neoplastic nature. METHODS: We investigated the immunohistochemical expression of the sonic hedgehog (SHH) signaling pathway-related proteins, PTCH, smoothened (SMO) and GLI-1, and of the SHH-induced bcl-2 oncoprotein in a series of primary OKC (pOKC), recurrent OKC (rOKC) and nevoid basal cell carcinoma syndrome-associated OKCs (NBCCS-OKCs), and compared them to solid ameloblastomas (SAMs), unicystic ameloblastomas (UAMs), 'orthokeratinized' OKCs (oOKCs), dentigerous cysts (DCs) and radicular cysts (RCs). RESULTS: All studied lesions expressed the SHH pathway-related proteins in a similar pattern. The expression of bcl-2 in OKCs (pOKCs and NBCCS-OKCs) and SAMs was significantly higher than in oOKCs, DCs and RCs (P < 0.001). CONCLUSIONS: The present results of the immunoprofile of OKCs (that includes the expression of the SHH-related proteins and the SHH-induced bcl-2 oncoprotein) further support the notion of OKC having a neoplastic nature. As OKCs vary considerably in their biologic behavior, it is suggested that the quality and quantity of interactions between the SHH and other cell cycle regulatory pathways are likely to work synergistically to define the individual phenotype and corresponding biological behavior of this lesion.

Immunohistochemical analysis of the patterns of p53 and PCNA expression in odontogenic cystic lesions.

OBJECTIVE: the role of p53 expression in odontogenic lesions has not been fully determined, but has been associated with cell proliferation. The purpose of this study was to analyze p53 and proliferating cell nuclear antigen (PCNA) expression in 4 different odontogenic lesions. DESIGN: expression of p53 and PCNA was analyzed in radicular and dentigerous cysts, odontogenic keratocysts, and calcifying odontogenic cysts (Gorlin cysts) using monoclonal antibodies for detection of p53 and PCNA. RESULTS: PCNA expression was significantly greater in the basal layer of radicular cysts and in the suprabasal layer of odontogenic keratocysts; the percentage of p53 positive cells was significantly greater in the suprabasal layer of odontogenic keratocysts. CONCLUSIONS: The patterns of p53 and PCNA expression in dentigerous and radicular cysts were similar although the two lesions are of different origin. In odontogenic keratocysts and Gorlin cysts, results indicate a different pattern of tumor growth.

Glandular odontogenic cyst in China: report of 12 cases and immunohistochemical study.

OBJECTIVE: The purpose of this study was to present 12 additional cases of glandular odontogenic cyst (GOC) in the Department of Oral Pathology, School of Stomatology, Wuhan University, People's Republic of China, and to investigate their immunohistochemical cytokeratins (CKs) expression in the epithelial components. METHODS: A total of 12 GOCs were reviewed clinically and radiographically, and immunohistologic CKs AE1, 7, 8/18, 10/13, 14, 16, 19 and 20 were performed by using a standard biotin-streptavidin immunoperoxidase technique on paraffin sections. RESULTS: The present series showed that eight occurred in males and four in females. The mean age was 37.6 years with a peak incidence occurring in the third decades (six of 12). Mandibles were more affected than maxillas (7:5), especially anterior mandible (four of seven). Radiographically, ratio multilocular to unilocular radiolucencies was 5:7 usually with well-defined borders. Histologically, cystic spaces were lined by non-keratinized stratified epithelia containing focal plaque-like or whirlpool-like thickenings; surface epithelial layer-containing eosinophilic cuboidal cells; mucous cells; and mucin pools of microcystic areas in the epithelium. Immunohistochemistry showed that epithelium of GOCs stained for CKs AE1, 7, 8/18, 10/13, 14 and 19 with slight changes in their patterns, and no reaction to CKs 16 and 20. CONCLUSIONS: Most clinical and histologic features in this study were analogous to those reported west population, although with slight difference between them. Histologically, the morphology of the epithelium strongly suggested an odontogenic origin, and CKs expression of GOC was similar to that of odontogenic epithelium, suggesting histochemically that GOC might be derived from odontogenic epithelium.

Effects of positive pressure in odontogenic keratocysts.

Intracystic fluid pressure is thought to be involved in odontogenic cyst growth. In this study, we investigated the effects of positive pressure on the expression of interleukin-1alpha (IL-1alpha), matrix metalloproteinases (MMPs), and prostaglandin E2 (PGE2) in odontogenic keratocysts to determine whether this pressure stimulates inflammatory cytokine production and signaling of osteoclastogenic events. Positive pressure enhanced the expression of IL-1alpha mRNA and protein in odontogenic keratocyst epithelial cells, and increased the secretion of MMP-1, MMP-2, MMP-3, and PGE2 in a co-culture of odontogenic keratocyst fibroblasts and the epithelial cells. The pressure-induced secretions were inhibited by an interleukin-1 receptor antagonist. Recombinant human interleukin-1alpha (rhIL-1alpha) increased the secretion of MMP-1, MMP-2, MMP-3, and PGE2 in the fibroblasts. Furthermore, in the fibroblasts, rhIL-1alpha enhanced the expression of macrophage colony-stimulating factor (M-CSF) mRNA, and rhIL-1alpha-induced PGE2 increased the expression of nuclear factor kappaB ligand (RANKL) mRNA. Thus, positive pressure may play a crucial role in odontogenic keratocyst growth via stimulating the expression of IL-1alpha in epithelial cells.

Cisto maxilar: caso clinico / cist maxilar: case report

O cisto da região globulomaxilar é encontrado exclusivamente na maxila, no interior do osso, na junção da porção globular do processo nasal mediano com o processo maxilar- a fissura globulomaxilar - geralmente entre o incisivo lateral superior e o canino. Possui a forma de pêra invertida, radiotransparente e circundado por um halo esclerótico. Os dentes adjacentes possuem vitalidade, a não ser que estejam infectados. Este relato de caso clínico refere-se a uma paciente melanoderma, 50 anos, que apareceu na clínica de CTBMF, encaminhada de uma cidade vizinha com uma tumefação dolorida na região esquerda da face, na altura da bochecha. Já no exame clínico, foi feita punção para alívio do edema e dor. A paciente foi submetida à cirurgia, posteriormente, para remoção do cisto e o exame anátomo-patológico confirmou os achados histológicos consistentes com cisto na região globulomaxilar, provavelmente, um cisto residual

The aggressive nature of the odontogenic keratocyst: is it a benign cystic neoplasm? Part 1. Clinical and early experimental evidence of aggressive behaviour.

In this, the first of three articles on the aggressive nature of the odontogenic keratocyst (OKC), there is a review of clinical and histological observations which indicated that this was an aggressive lesion with a predilection for recurrence unlike the majority of other jaw cysts. This led to the tentative suggestion that the OKC might be a benign neoplasm. Subsequently there were early laboratory investigations that compared proliferation rates of the OKC epithelium with other jaw cysts, comparative enzyme histochemistry to assess aspects of its metabolism and markers that would enable accurate presurgical diagnosis of this cyst. Comparative studies were also pursued on the walls of the OKC and other jaw cysts to identify factors that might influence the capacity of the OKC to resorb the bone surrounding it. The clinical and laboratory studies reviewed in this section provided cogent presumptive evidence of the distinctively aggressive nature of the OKC that led numbers of investigators to pursue immunocytochemical and genetic studies on this cyst. Parts 2 and 3 of this series review this work.

Expresión de la proteína p53 en quistes dentígeros y queratoquistes odontogénicos / p53 protein expression in dentigerous cysts and odontogenic keratocysts

Objetivo: Se realizó un estudio descriptivo comparativo para valorar la expresión de la proteína p53 en los quistes dentígeros (QD) y queratoquistes odontogénicos (QQO), con sus variantes ortoqueratósica (QQO-O) y paraqueratósica (QQO-P), con el propósito de relacionar el grado de expresión de la proteína p53 con el potencial de agresividad de las patologías mencionadas. Método: La proteína p53 fue identificada, empleando el anticuerpo monoclonal M7001 junto con técnica de inmunoperoxidasa estándar. Se emplearon un total de 25 muestras de tejido, fijadas en formalina neutra y embebidas en parafina, correspondientes a 13 quistes dentígeros y 12 queratoquistes odontogénicos, previamente diagnosticados histológicamente. Estas fueron obtenidas de los archivos de Patología Oral de la Facultad de Odontología de la Pontificia Universidad Javeriana. La expresión de la proteína p53 fue medida observando el número de células con núcleos teñidos de color café en el epitelio quístico y que fueron identificadas con el miroscopio óptico de luz. Resultados: Grado de expresión nulo (72 por ciento) distribuidos así: QD 52 por ciento, QQO-O 16 por ciento y QQO-P 4 por ciento; grado de expresión leve (8 por ciento distribuidos así: QQO-O 4 por ciento y QQO-P 4 por ciento; grado de expresión moderado (20 por ciento) se presentó únicamente en los QQO-P. Ninguna patología presentó grado de expresión alto. La variable localización también fue estudiada relacionándola con el grado de expresión; no mostró significancia clínica. Conclusiones: La proteína p53 marcó más en los queratoquistes odontogénicos comparada con los quistes dentígeros, posiblemente por los cambios de queratinización que se presentan en su epitelio, siendo ésta una característica histológica importante en lesiones con potencial de transformación neoplásica o carcinomaS propiamente dichos

B cell- and monocyte-activating chemokine (BMAC), a novel non-ELR alpha-chemokine.

A novel alpha-chemokine, designated KS1, was identified from an EST database of a murine immature keratinocyte cDNA library. The EST has 94% similarity to a recently cloned human gene, BRAK, that has no demonstrated function. Northern analysis of mouse and human genes showed detectable mRNA in brain, intestine, muscle and kidney. Tumour panel blots showed that BRAK was down-regulated in cervical adenocarcinoma and uterine leiomyoma, but was up-regulated in breast invasive ductal carcinoma. KS1 bound specifically to B cells and macrophages, as well as two B cell lines, CESS and A20, and a monocyte line, THP-1. KS1 showed no binding to naive or activated T cells. In addition, KS1 stimulated the chemotaxis of CESS and THP-1 cells but not T cells. The s.c. injection of KS1 creates a mixed inflammatory response in Nude and C3H/HeJ mice. The above data indicates that KS1 and its human homologue represents a novel non-ELR alpha-chemokine that may have important roles in trafficking of B cells and monocytes. We propose the name B cell- and monocyte-activating chemokine (BMAC) for this molecule to reflect the described biological functions.

Expressäo do antígeno nuclear de proliferaçäo celular (PCNA) e da proteína p53 em cistos odontogênicos / Study of the expression of the antígeno of celular proliferation (PCNA) and of the proteína p 53 in odontogênico cysts

Os cistos odontogênicos represetam entidades de interesse na clínica odontológica em funçäo de sua frequência e comportamento biológico variado. Levando em consideraçäo que a atividade proliferativa pode interferir no curso clínico dessas lesöes, foi avaliado nestetrabalho, a expressäo do PCNA e da proteína p53 em 11 ceratocistos odontogênico, 12 cistos dentígero, 12 cistos odontogênicos calcificantes e 11 cistos radiculares, através do método da streptavidina-biotina. Todos os casos analisados demonstraram positividade ao PCNA. Os ceratocistos odontogênicos e os cistos odontogênicos calcificantes expressaram maior reatividade com índices de 42,6 porcento e 41,13 porcento, respectivamente, enquanto cistos dentígeros e radiculares exibiram imunorreatividade em 32,45 porcento e 26,45 porcento, dos cistos estudados. Os índices de positividade do PCNA foram comparados entre os 4 grupos de cistos através da análise de variância e teste qui-quadrado, näo sendo verificada, no entanto, difernça estatisticamentesignificante. Por outro lado, somento 2 casos de cistos odontogênicos calcificantes e 1 cisto dentígero expressaram a proteína p53, os índices foram expressos em porcentuais. Frente a estes dados, concluímos que näo foi possível relacionar a expressäo da proteína p53 e do antígeno nuclear de proliferaçäo celular (PCNA) à atividade proliferativa do epitélio cístico e seu comportamento biológico (

Comparison of proliferating cell nuclear antigen expression in odontogenic keratocyst and ameloblastoma: an immunohistochemical study.

Proliferating cell nuclear antigen (PCNA) is a nuclear protein synthesized in the late G1 and S phase of the cell cycle, and immunohistochemical detection of the protein represents a useful marker for the proliferating fraction of cells in tissue specimens. PCNA expression was studied in odontogenic keratocysts (n = 15) and ameloblastomas (n = 46) using an avidin-biotin-peroxidase complex method on routinely processed paraffin sections. The percentage of PCNA-positive cells determined by point counting was significantly lower in the ameloblastomas (mean 9.4%, standard deviation (SD) 11.0) than in odontogenic keratocysts (mean 29.9%, SD 24.0). In ameloblastomas, the mean percentage of PCNA-positive cells was lowest in the acanthomatous pattern and highest in plexiform pattern. The mean percentage of PCNA-positive cells in plexiform pattern was non-significantly higher than that in follicular pattern. The mean percentage of PCNA-positive cells in plexiform and follicular patterns was significantly higher than that in cystic and acanthomatous patterns. The frequency of PCNA-positive cells was significantly higher in the peripheral cells of follicular and plexiform patterns than in the central cells of both patterns (p < 0.01). Therefore, peripheral cells were regarded as reserve cell of central cells. The mean percentage of PCNA-positive cells in the epithelial lining of odontogenic keratocyst was not significantly different from those in the peripheral cells of follicular and plexiform patterns of ameloblastoma. In contrast, the odontogenic keratocyst exhibited a mean percentage of PCNA-positive cells which was statistically higher than that in other histological elements of ameloblastomas. The present study suggests that odontogenic keratocyst is regarded as benign odontogenic tumour.

Immunohistochemical detection of Fas antigen in oral epithelia.

A monospecific and high titer polyclonal antibody, designated as Fas D, raised against synthetic polypeptides selected from a part of the human Fas antigen (aa 104-114), was used to identify the Fas antigen in human oral epithelia in normal and pathological states. The human gingival proteins had been extracted and analysed by an ABC (avidin-biotin complex) immunoblotting technique. The antibody interacted with a single band in gingival proteins with an estimated molecular weight of 35,000, which is in good agreement with that calculated from amino acid sequences of the human Fas antigen. Using an indirect immunohistochemical method, the antibody localized on the stratum spinosum and the basal part of the stratum corneum of normal human gingiva. Specimens obtained from patients with odontogenic keratocysts, leukoplakia, lichen planus, and squamous cell carcinoma were also stained with the antibody. The pattern of the Fas antigen distribution in oral stratified squamous epithelia was, with some overlapping, characteristic for each disease.

Epithelial cell proliferation in odontogenic keratocysts: a comparative immunocytochemical study of Ki67 in simple, recurrent and basal cell naevus syndrome (BCNS)-associated lesions.

The aim of the present study was to investigate epithelial cell proliferation in the linings of odontogenic cysts, including three different subtypes of odontogenic keratocyst (OKC), namely simple (non-recurrent), recurrent and basal cell naevus syndrome (BCNS)-associated lesions. Ki67 immunoreactivity in OKC (simple, n = 10; recurrent, n = 8; syndrome, n = 9), dentigerous cysts (DC, n = 5), radicular cysts (RC, n = 5) and normal oral mucosa (n = 7) was studied using a biotin-streptavidin-peroxidase method on paraffin sections after microwave treatment. Ki67+ epithelial cells were counted manually and related to the length of basement membrane (BM) as determined by TV image analysis. Data were analysed by the Mann-Whitney U test. The number of Ki67+ cells in simple OKC linings (53.1 +/- 17.8 cells/mmBM) was similar to that in oral epithelium (42.5 +/- 12.7 cells/mmBM; P > 0.2). However, both contained significantly more Ki67+ cells than DC (3.9 +/- 1.3 cells/mmBM) and RC linings (6.7 +/- 4.8 cells/mmBM; P < 0.006). The epithelial distribution of Ki67+ cells differed between groups, with the percentage of positive cells in basal layers in OKC linings (7.0 +/- 2.1%) being significantly lower than that of oral epithelia (35.9 +/- 5.6%), DC (78.4 +/- 8.4%) and RC (80.6 +/- 7.7%) linings respectively (P < 0.003). Comparison of Ki67 expression within the OKC group revealed no significant difference between simple and recurrent lesions (44.0 +/- 13.8 cells/mmBM; P > 0.3). However, OKC associated with BCNS contained significantly higher numbers of Ki67+ cells (91.8 +/- 35.6 cells/mmBM; P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Estudo imunocitoquímico comparativo dos folículos pericoronários, cistos dentígeros e queratocistos odontogênicos / Immunohistochemical comparative study of the dental follicles with dentigerous cysts and odontogenic keratocysts

Com o objetivo de estabelecer as características imunocitoquímicas de folículos pericoronários, cistos dentígeros e queratocistos odontogênicos, foram selecionados dos arquivos do Laboratório de Anatomia Patológica do Departamento de Patologia da Faculdade de Odontologia de Bauru USP, dez casos de folículos pericoronários com epitélio reduzido do orgäo do esmalte, dez casos de folículos pericoronários com metaplasia escamosa, dez casos de cistos dentígeros e dez casos de queratocistos odontogênicos, submetidos a evidenciaçäo imunocitoquímica de um painel constituído dos seguintes marcadores: citoqueratina de alto peso molecular, citoqueratina de baixo peso molecular, laminina, fibronectina, colágeno IV, vimentina e proteína S100. A partir dos resultados obtidos pudemos concluir que o padräo imunocitoquímico das 4 condiçöes estudadas permite uma diferenciaçäo diagnóstica entre folículos pericoronários, cistos dentígeros e queratocistos odontogênicos, utilizando-se a marcaçäo da proteína S100. A diferenciaçäo pela marcaçäo com a proteína S100 pode ser complementada pela evidenciaçäo das células de Langerhans, que caracteristicamente estäo presentes nos revestimentos epiteliais dos cistos dentígeros