Assessment of dental and periodontal indices and Streptococcus mutans virulence in fragile X syndrome patients.

INTRODUCTION: Fragile X syndrome (FXS) is the most common cause of hereditary genetic disorder in a single gene characterised by intellectual disability. Behavioural features such as autism, hyperactivity and anxiety disorder may be present. Biofilm development and pathogenicity of Streptococcus mutans may be altered because FXS renders the dental approach and oral hygiene more complex. OBJECTIVES: The purpose of this study was to compare the levels of transcripts for VicRK and CovR of S. mutans isolated from FXS patients with the levels of transcripts for VicRK and CovR of standard strain ATCC, using a quantitative polymerase chain reaction (qPCR). METHODS: The caries experience index was assessed by the International Caries Detection and Assessment System (ICDAS), Periodontal Condition Index (PCI) and Invasive Dental Treatment Need Index (INI). RESULTS: The clinical index findings revealed a high rate of caries cavities and bleeding on probing of FXS patients. When VicRK and CovR transcript levels were compared with the reference strain, Fragile X patients were found to have significantly higher values. CONCLUSION: The present study demonstrated that FXS patients have more adverse clinical conditions, with increased biofilm accumulation and virulence. When combined with behavioural abnormalities, these patients become even more vulnerable to dental caries.

Mini-implants for Orthodontic Anchorage: Surface Analysis after Redrilling and Sterilization - An in vitro Study.

OBJECTIVE: This study aimed to investigate, in vitro, possible alterations on mini-implants surface after retrieval and if the cleaning process and sterilization can predispose damages. MATERIALS AND METHODS: Two commercial mini-implants were tested for deformations after drilling and removing in artificial bone four times. Samples were analyzed by scanning electron microscopy, and surface alterations verified through thread and pitches deformation. To alterations caused by insertion/removal and the cleaning process and sterilization were verified in different procedures: Insertions and sterilization, only insertions, and only sterilization. Photomicrographs were analyzed in order to compare the surface characteristics. Head deformation was verified qualitatively. For a quantitative analysis, distances between threads were measured across the active part of the mini-implants. RESULTS: No deformation was observed in both groups. The cleaning and sterilization processes did not provoke alteration in both groups. Nevertheless, the presence of synthetic bone was noted in some samples. The mean distances between implant threads were similar after all steps in all regions in both groups. CONCLUSION: The results suggest that the tested mini-implants can be retrieved without damage of its surface after four cycles of insertion, removal, and sterilization. KEYWORDS: Orthodontic mini-implant, Redrilling, Sterilization. CLINICAL SIGNIFICANCE: Mini-implants can be retrieved without damage to its surface after four cycles of insertion, removal, and sterilization in the same patient without representing a biological concern.

Lymphatic vessel density and expressions of lymphangiogenic growth factors in salivary carcinomas.

Nodal metastasis is an important prognostic indicator in head and neck cancers, including salivary carcinomas. In these, the risk for lymph node metastasis is variable and strongly associated with the tumor histologic type. The aim of the current study was to evaluate the lymphatic vessel density (LVD) and expressions of lymphangiogenic growth factors by tumor cells in different histologic types of salivary carcinomas subdivided according to the risk for nodal metastasis. In 15 high-risk (undifferentiated, high-grade mucoepidermoid and salivary duct carcinomas) and 60 low/moderate-risk tumors (adenoid cystic, low/intermediate-grade mucoepidermoid, acinic cell, myoepithelial, epithelial-myoepithelial and polymorphic low-grade carcinomas) the expressions of vascular endothelial growth factor-C (VEGF-C), hepatocyte growth factor (HGF) and D2-40 (for assessing LVD) were examined. No significant differences were encountered between high- and low/moderate/-risk carcinomas regarding LVD and VEGF-C or HGF expressions. Furthermore, the expression of these proteins did not correlate with LVD. Lymphatic vascular invasion was found mainly in high-risk carcinomas. Intratumoral LVD was significantly lower than peritumoral, regardless of the risk for metastasis and primary site of the lesion. The histologic types of salivary carcinomas which are associated with high-risk for nodal metastasis do not present increased LVD or VEGF-C and HGF expressions. The greater tendency for metastasis in these carcinomas seems to be related to their capacity to invade lymph vessels. Further studies on tumor cell interactions with lymphatic endothelial cells are needed to improve our understanding of the metastatic potential of salivary carcinomas.

Actinic cheilitis among agricultural workers in Campinas, Brazil.

OBJECTIVE: To assess the prevalence of Actinic Cheilitis (AC) among agricultural workers and analyze its risk factors. DESIGN: A cross sectional epidemiological study. A lip lesion was defined as an abnormal change on the lip mucosa surface, such as erythematous pigmented, ulcerative or swelling (Cataldo and Doku, 1981). Data were gathered according to age group, gender, ethnicity-time and frequency of occupational sunlight exposure, smoking habits, drinking habits and socio-economic status. SETTING: Sugar-cane plantation farms in Brazil. PARTICIPANTS: Full-time workers of both genders employed at sugar-cane plantation farms for at least six months. OUTCOME MEASURES: Correlations between AC prevalence, demographic and socioeconomic risk factors. RESULTS: 202 people were examined and the prevalence of AC was 39.6%. Results revealed that being black (0.15-0.88- 95% CI; OR = 0.36; p = 0.025) or mulatto (0.21-0.82- 95% CI; OR = 0.42; p =0.011) decreased the risk for AC, while age and gender sex had no effect. In relation to socioeconomic variables, formal education and more than four years of education (0.07-0.68- 95% CI; OR = 0.22; p = 0.009) decreased the risk for AC. Moreover, drinking alcohol was a risk for AC (1.05-3.37- 95% CI; OR = 1.88; p = 0.034), while tobacco smoking was not (0.60-2.02- 95% CI; OR = 1.10; p = 0.763). CONCLUSIONS: The prevalence of AC is high in agricultural workers who were fairskinned, had low education and high alcohol intake. Prevention and early diagnosis are required for workers exposed to sunlight.

Spatiotemporal Dynamics and Natural Mortality Factors of Myzus persicae (Sulzer) (Hemiptera: Aphididae) in Bell Pepper Crops.

Pest populations are mostly regulated by climate, intra- and interspecific competition, natural enemies, and host plant quality. Myzus persicae (Sulzer) (Hemiptera: Aphididae) is a widely adapted aphid in the agroecosystems and is one of the main bell pepper pests. In the present study, we determined the spatial and temporal dynamics and the regulatory factors of M. persicae populations in bell pepper crops. The number of aphids and their natural enemies were evaluated during 2 years in four commercial bell pepper fields. Myzus persicae density data were related to temperature, rainfall, and natural enemies by multiple regression analysis and were then submitted to geostatistical analysis. The density of M. persicae was higher during the plant's reproductive growth stage. Rainfall, Chrysoperla spp., and Toxomerus spp. regulate M. persicae populations. Initial infestations of this pest occur along the edges of the fields and subsequently spread towards the center. This information is useful for integrated management programs aimed at anticipating periods of higher abundance of M. persicae and identifying arthropods to be prioritized in biological control.

Angiogenesis in salivary carcinomas with and without myoepithelial differentiation.

To investigate whether salivary carcinomas with and without myoepithelial differentiation could present differences regarding degree of angiogenesis, we compared tumor vascularization between adenoid cystic (31 cases) and epithelial-myoepithelial carcinomas (14) versus mucoepidermoid (37) carcinoma. The expression of peroxiredoxin I was also studied to verify the potential relationship between cellular metabolism and microvascular density. Microvascular density for CD34 and CD105 were significantly lower in carcinomas with myoepithelial differentiation. However, no correlation was found between degree of angiogenesis and amounts of myoepithelial cells. High-grade peroxiredoxin I expression was found in 73.7% of mucoepidermoid carcinomas, whereas 85.1% of carcinomas with myoepithelial differentiation presented low-grade expression. In conclusion, carcinomas with myoepithelial differentiation, regardless of the amounts of myoepithelial cells, are associated to a significantly lower vascular density. The reasons for this lower angiogenic activity remain to be determined but could be related to metabolic characteristics of the cancer cells.

Substance P regulates the expression of matrix metalloproteinases and tissue inhibitors of metalloproteinase in cultured human gingival fibroblasts.

BACKGROUND AND OBJECTIVE: Substance P may play a role in the pathogenesis of periodontal disease; however, its mechanisms of modulation are not clear. This study evaluated the effect of two concentrations of Substance P on the expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in cultured human gingival fibroblasts. MATERIAL AND METHODS: Fibroblasts were stimulated for 48 h with 10(-4) or 10(-9) m Substance P; untreated fibroblasts served as controls. The expression of MMP-1, -2, -3, -7 and -11 and of TIMP-1 and -2 was evaluated using real-time polymerase chain reaction and western blotting. RESULTS: There was a significant, concentration-dependent stimulatory effect of Substance P on MMP-1, -2, -3 and -7 and TIMP-2 gene expression (p < 0.05), and a probable effect on MMP-11 (p = 0.06). At the higher concentration (10(-4) m Substance P), MMP-1, -2, -3, -7 and -11 and TIMP-2 showed the greatest up-regulation; at the lower concentration (10(-9) m Substance P), MMP-1, -3 and -7 and TIMP-2 exhibited diminished up-regulation, with MMP-2 and -11 showing down-regulation (p < 0.05). Expression of TIMP-1 was not affected by Substance P (p > 0.05). Western blotting confirmed that Substance P up-regulated MMP-1, -2, -3 and -11 and TIMP-2. MMP-1, -3 and -11 and TIMP-2 showed greater up-regulation at the higher Substance P concentration and diminished up-regulation at the lower concentration. MMP-2 was up-regulated to a similar degree at both Substance P concentrations. CONCLUSION: In gingival fibroblast cells, Substance P at the higher concentration (10(-4) m) induced greater up-regulation of MMP-1, -3 and -11 and TIMP-2 expression, but at the lower concentration (10(-9) m) induced diminished up-regulation, which may represent a mechanism for modulating periodontal breakdown.

Peroxiredoxin I is differentially expressed in multiple myelomas and in plasmablastic lymphomas.

BACKGROUND: Plasmablastic lymphoma (PBL) and multiple myeloma (MM) are B cell-derived malignancies that share many morphologic and immunophenotypic traits, making the differential diagnosis particularly complicated. We have recently demonstrated that peroxiredoxin I (PrdxI) is expressed in plasma cells but not in B lymphocytes, suggesting that its expression is development-associated. AIM: To analyze PrdxI expression in PBL and in MM in order to study its utilization as an additional diagnostic molecular tool. METHODS AND RESULTS: Eight cases of PBL and nine of MM were studied by immunohistochemistry. We have demonstrated that PrdxI expression is closely connected with the immunoglobulin production capacity of the cells, which means high in MM, but absent in PBL cases, except one, wherein few cells were stained. CONCLUSIONS: We hypothesize PrdxI as a component of the unfolded protein response (UPR), an adaptive pathway essential for plasma cell differentiation. As we have not detected immunoglobulin in our PBL cases, we suggest that UPR was not activated in the cells, accounting for the impediment of the developmental process, and for the inhibition of PrdxI expression observed. PrdxI could be considered an additional plasma cell functional marker and could also be speculated as a therapeutic target in the treatment of MM.

Acid phosphatase and cathepsin D are active expressed enzymes in the placenta of the cat.

Enzymes are crucial for the metabolism of macromolecular substrates. In the great majority of cells, most enzymes are constitutive. Nevertheless, inducible enzymes can predominate, determining specialized cell functions. Within this context, histochemistry/immunohistochemistry and biochemistry were used to investigate expression of peroxidase and reduced nicotinamide-adenine dinucleotide phosphate (NADPH)-oxidase, as well as the expression and activity of cathepsin D and acid phosphatase, in trophoblast cells within the endotheliochorial labyrinth and marginal hematoma of the term cat placenta. In the marginal hematoma, elevated Cathepsin D expression and activity was accompanied by erythrophagocytosis. In contrast, acid phosphatase activity was much more intense in the labyrinth, where metabolic exchanges occur. Peroxidase and NAD(P)H-oxidase were predominantly active in trophoblast cells within endosomal vesicles of different placental compartments, indicating that, although reactive oxygen species might participate in endosomal/lysosomal processes, they are not territorially specific or functional markers. These findings highlight differential characteristics of cathepsin D and acid phosphatase activity within each placental compartment, thereby contributing to the comprehension of the territorial role played by the placenta and facilitating future metabolic studies.

Angiogenic switch during tumor progression of carcinoma ex-pleomorphic adenoma.

We analyzed the tumor vascularization in carcinomas ex-pleomorphic adenoma (CXPA) to investigate the angiogenic switch during the malignant transformation of pleomorphic adenoma (PA) to carcinoma and during tumor progression. In eight cases of early CXPA (intracapsular and minimally invasive tumors), eight of advanced CXPA (widely invasive tumors), and ten of PA without malignant transformation, tumor vascularization was assessed in histological samples by measuring total microvascular area (TVA) and microvessel density (MVD) using CD34 and CD105 antibodies. MVD for CD105 increased significantly during tumor progression, whereas this was not the case for CD34 MVD. Comparing widely invasive CXPA with and without myoepithelial differentiation, CXPA with myoepithelial differentiation showed a significantly lower number of CD105 positive vessels but revealed higher TVA values. In these tumors, the neoplastic cells usually formed larger hypovascularized aggregates that were often surrounded by large-sized vessels. In conclusion, the antibody CD105 reveals an angiogenic switch during the progression from adenoma to carcinoma in salivary glands. The degree of angiogenesis and the total vascular area have distinctive patterns in CXPA with and without myoepithelial differentiation. Low angiogenesis associated with high TVA value is more characteristic of CXPA with myoepithelial differentiation.

Lymphatic vascular density and lymphangiogenesis during tumour progression of carcinoma ex pleomorphic adenoma.

AIMS: To assess lymphatic vascular density (LVD) and lymph vessel endothelial proliferation in a series of carcinoma ex pleomorphic adenoma (CXPA) that represents the tumour in the different carcinogenesis phases and tumour progression. METHODS: In 8 cases of early CXPA (intracapsular and minimally invasive tumours), 8 of advanced CXPA (widely invasive tumours) and 10 of pleomorphic adenoma (PA) without malignant transformation, lymphatic vessels and proliferating cells were detected using the antibodies D2-40 and Ki-67 respectively. RESULTS: Comparing early tumours with advanced ones, LVD was not significantly different at the tumour margin. In contrast, regarding intratumoural lymphatics, PA without malignant transformation and early CXPA contained rare, if any, lymph vessels, whereas in widely invasive carcinomas they were more numerous. However, neither intratumoural nor peritumoural LVD were increased in comparison to adjacent normal salivary gland tissue. In no case did dual immunohistochemistry using D2-40 and the cell proliferation marker Ki-67 reveal the existence of proliferating lymphatics. Carcinomatous emboli were found in peritumoural as well as in intratumoural lymphatics only in advanced CXPA without myoepithelial differentiation. CONCLUSION: In CXPA, the lymphatic network is mainly composed of pre-existing lymphatics which are rare in tumours that have not infiltrated outside the confines of the original PA. In the widely invasive CXPA, intratumoural as well as peritumoural lymphatics are a conduit for carcinoma cells, but in carcinomas with myoepithelial differentiation, the neoplastic cells seem to have a lower invasion capacity.

Nrf2-peroxiredoxin I axis in polymorphous adenocarcinoma is associated with low matrix metalloproteinase 2 level.

Polymorphous adenocarcinoma (PAC) is a malignant epithelial neoplasm that affects almost exclusively the minor salivary glands, generally described as having a relatively good prognosis. Aberrant nuclear factor erythroid 2 (NF-E2)-related factor (Nrf2) activation in tumor cells has been associated with induction of antioxidant enzymes, such as peroxiredoxin I (Prx I) and increased matrix metalloproteinase (MMP) expression. In this context, the aim of the present study was to evaluate the expression of Nrf2 and correlate it with Prx I and MMP-2 secretion in PAC. Thirty-one cases of PAC from oral biopsies were selected and immunohistochemically analyzed for Nrf2 and Prx I. MMP-2 quantification was performed on primary cell cultures derived from PAC. Oral squamous cell carcinoma (OSCC) cell cultures were used as control. A high immunoexpression of Nrf2 was observed in both the cytoplasm and the nucleus of neoplastic cells from PAC. Nuclear staining for Nrf2 suggested its activation in the majority of the PAC cells, which was confirmed by the high expression of its target gene, Prx I. Quantification of MMP-2 secretion showed lower levels in PAC cell cultures when compared to OSCC cell cultures (p < 0.05). In conclusion, although Nrf2 overexpression has been frequently associated with high-grade malignancies, such relationship is not infallible and, in fact, the opposite may occur in low-grade tumors, such as PAC of minor salivary glands.

Maspin expression in carcinoma ex pleomorphic adenoma.

AIMS: To investigate the presence and distribution of the protein maspin in carcinoma ex pleomorphic adenoma (CXPA). METHODS: Maspin expression was studied by means of immunohistochemistry in 16 cases of CXPA, using the labelled polymer method. RESULTS: According to the extent of invasion, the tumours were subdivided into: intracapsular (five cases), minimally invasive (four cases), and invasive (seven cases). Twelve patients had carcinoma with only epithelial differentiation, whereas four had a malignant myoepithelial component. Non-luminal cells in the duct-like structures of the remnant pleomorphic adenoma were strongly positive for maspin, whereas only a few luminal cells were immunopositive. A few positive cells were seen in the frequent hypocellular and hyalinised areas. Maspin was abundantly expressed, mainly in non-luminal cells, in transitional areas of CXPA with only epithelial differentiation. In frankly carcinomatous areas there was a gradual decrease in maspin expression. Almost all cells were maspin positive in CXPA with a myoepithelial component. When present, luminal cells were in general negative for maspin. CONCLUSIONS: When only epithelial cells undergo malignant transformation, maspin expression is gradually lost. In cases with a myoepithelial component, maspin expression is high, and this might be related to the tumour suppressor activity attributed to this cell.

Effect of spatial arrangement of the basement membrane on cultured pleomorphic adenoma cells. Study by immunocytochemistry and electron and confocal microscopy.

In a cell line from human pleomorphic adenoma (AP2 cells) we studied the response of these cells to basement membrane proteins. The culture was characterized as myoepithelial-like by transmission electron microscopy and immunocytochemistry. AP2 cells were grown in contact with a reconstituted basement membrane (Matrigel). Cells grown on Matrigel showed conspicuous phenotypic alterations, depending on how the substrate was applied. Cells grown on the top of Matrigel developed a dendritic phenotype, exhibiting thin, long and intercommunicating cytoplasmic extensions resembling normal myoepithelial cells. Cells grown inside Matrigel formed multi-layered clusters. Light, confocal and transmission electron microscopy showed that these clusters were formed by double-layered epithelioid cells delimiting luminal spaces. The cells facing the lumen were cuboidal, showing microvilli at the apical plasmalemmal and junctional complexes. The spatial arrangement of basement membrane is a key modulator of morphogenetic changes and cytodifferentiation of tumour myoepithelial cell lineage in culture.

Salivary duct carcinoma: immunohistochemical profile of an aggressive salivary gland tumour.

BACKGROUND: Salivary duct carcinoma (SDC) is considered to be a distinct malignancy of the major salivary glands, because of its highly aggressive behaviour, and the high rate of recurrence, metastasis, and disease related death. AIMS: To investigate expression of the proteins involved in the retinoblastoma (pRb) and p53 pathways, which control cell cycle progression at the G1/S checkpoint, and also expression of the c-erbB-2 oncoprotein in SDCs. METHODS: Using a streptavidin-biotin method, five cases of SDC were evaluated immunohistochemically for the presence of cyclin D1, CDK4 (cyclin dependent kinase 4), p16 (CDK2A), pRb (retinoblastoma protein), E2F-1, p53, mdm2 (murine double minute 2), bcl-2, and the c-erbB-2 oncoprotein to determine whether there was a correlation between the expression of these proteins and patient outcome. RESULTS: All of the cases showed deregulation of the pRb and p53 pathways. Of the five patients analysed, only the patient with longterm survival (10 years) was not positive for c-erbB-2 expression. CONCLUSIONS: c-erbB-2 overexpression was associated with a poor prognosis. Aggressive behaviour, recurrence, and metastatic potential do not appear to be related to cell cycle deregulation, but seem to be associated with the c-erbB-2 oncoprotein, which is involved in matrix degradation and proteolitic activity, in addition to increases in vessel permeability, endothelial cell growth, proliferation, migration, and differentiation. There was a correlation between c-erbB-2 oncoprotein expression and aggressive behaviour in SDCs.

Basal cell adenocarcinoma of the palate with squamous metaplasia.

Basal cell adenocarcinoma is a rare salivary gland tumour, especially in minor glands. The clinical, histological, and immunohistochemical features of a case involving the palate are described. Formalin fixed, paraffin embedded sections of the tumour were examined in haematoxylin and eosin (H&E) sections and also using immunostaining for cytokeratins 7, 8, 13, 14, 18, 19, vimentin, muscle specific actin (HHF35), and laminin. H&E sections showed that the tumour was composed mainly of basaloid cells and a striking feature was the presence of squamous metaplasia. Neural invasion was also conspicuous. Immunohistochemical reactions indicated that cytokeratin 14 was expressed by all tumour cells and vimentin by all cells except those in the areas of squamous metaplasia. The remaining cytokeratins and actin were present in some of the tumour cells, while laminin showed discreet positivity around cell arrangements. The foci of squamous metaplasia and the immunohistochemical findings are helpful in distinguishing basal cell adenocarcinoma from other salivary gland tumours which show basaloid cells.

Application of immunohistochemistry to the diagnosis of salivary gland tumors.

A panel of antibodies composed of the cytokeratins (CKs), vimentin, and actin was applied to 114 minor salivary gland tumors to evaluate its diagnostic value. The results revealed that luminal cells of intercalated duct-like structures, such as those seen in pleomorphic adenoma, basal cell adenoma, adenoid cystic carcinoma, and epithelial-myoepithelial carcinoma, expressed CKs 7, 8, 14, and 19. The outer cells of these structures exhibited vimentin or vimentin plus muscle-specific actin, but rarely CK14, which is seen particularly in pleomorphic adenoma, in the tubular type of basal cell adenoma, and seldom in the tubular type of adenoid cystic carcinoma. Modified myoepithelial cells of pleomorphic adenoma and myoepithelioma exhibited a variable immunoprofile. CKs 7 and 8 were also observed in acinar cell adenocarcinoma and polymorphous low-grade adenocarcinoma with vimentin in the latter. CK13 was expressed only by canalicular adenoma and mucoepidermoid carcinoma cells. This study showed that the panel of antibodies employed is effective in distinguishing among salivary gland tumors.

Immunohistochemical study of acinic cell carcinoma of minor salivary gland.

Acinic cell carcinoma (ACC) is a rare salivary gland tumour, making up 4% of all minor salivary gland tumors. Typically, it is composed of acinic cells although transitional and duct-like cells are also identified. In the present study, a panel of antibodies was applied to eight minor salivary gland ACCs. Antibodies tested were: cytokeratins 7, 8, 13, 14, 18, 19, vimentin and actin (HHF35). Immunohistochemical staining revealed that cytokeratin 8, among the tested antibodies, was the more specific to neoplastic cells with a pattern of distribution quite variable and peculiar. This staining may be useful in the recognition of neoplastic acinic cells.

Immunohistochemical expression of retinoblastoma pathway proteins in normal salivary glands and in salivary gland tumours.

The expression of G1-phase cell-cycle regulators is commonly deregulated in human malignancies. In the present study, we investigate components of the retinoblastoma (RB) pathway in normal salivary glands (NSG) and in salivary gland tumours (SGT). Samples of NSG, pleomorphic adenoma (PA), adenoid cystic carcinoma (ACC), mucoepidermoid carcinoma (MEC), epithelial-myoepithelial carcinoma (EMC), malignant myoepithelioma (MEM), carcinoma ex pleomorphic adenoma (CEPA), and polymorphous, low-grade adenocarcinoma (PLGA) were examined immunohistochemically using antibodies to cyclin D1, cyclin-dependent kinase 4 (CDK-4), retinoblastoma protein (pRb), CDK inhibitor p16 and transcription factor E2F-1. In normal salivary glands, cyclin D1 and cdk-4 were not expressed in any case while p16 was positively expressed. pRb was abundant and E2F-1 moderately expressed. In tumors, cdk-4 was overexpressed in half of the cases. Most tumour cases showed decreased pRb immunoexpression compared to normal salivary glands. In contrast, expression of p16 and E2F-1 increased. pRb expression was absent in three cases of PA, two of EMC and one of CEPA. One case of MEM and one of PLGA showed no E2F-1 expression. Statistical analyses revealed positive correlations between cyclin D1 and cdk-4, cyclin D1 and E2F-1, cdk-4 and E2F-1, and p16 and E2F-1. The benign and malignant tumours expressed retinoblastoma pathway proteins differently form the normal salivary gland. Our findings suggest that, pRb pathway deregulation in salivary gland neoplasms is unrelated to their biological behaviour.

Analysis of epithelial-myoepithelial carcinoma based on the establishment of a novel cell line.

Epithelial-myoepithelial carcinoma of the salivary gland is a rare, low-grade, neoplasm, composed of ductal and myoepithelial cells. We present two novel cell lines, which have been characterised by immunofluorescence, derived from an epithelial-myoepithelial carcinoma of the parotid gland. A resected mass of the parotid gland was diagnosed as an epithelial-myoepithelial carcinoma by routine histological examination. Part of the specimen was labelled with a panel of antibodies confirming the tumour type. The other part was finely minced and the explants were incubated in DMEM supplemented with penicillin and streptomycin, at 37 degrees C in a humidified 5% CO(2) atmosphere. Two cell types were identified by immunofluorescence-a small cobblestone cell, positive for AE1/AE3 and p53, and a polyhedral cell, positive for vimentin, smooth muscle markers and S-100. Herein two cell lines are presented in order to open up possibilities of new studies and a discussion of the events that culminate in this bimodal neoplasm is also performed.