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Biomedical subjects

N S Araújo

Publications and source records attributed to N S Araújo.

At least 19 recordsLinked to original sources
PubMed2006

Effect of a topical antimicrobial paste on healing after extraction of molars in HIV positive patients: randomised controlled clinical trial.

AIM: To assess the efficacy of a medicated dressing in the socket on the healing after dental extractions in HIV positive patients. PATIENTS AND METHODS: Forty HIV positive patients with CD4 counts below 200 cells/mm(3) who were to have molar teeth extracted were randomly allocated to have the socket dressed with a medicated paste (Rifocort) with camphorated parachlorophenol and iodoform) and sutured (treated group), or merely sutured (control group). RESULTS: The sockets in the treated group healed more quickly than in the control group.

Administration, Topical↗
PubMed2005

Carcinoma ex pleomorphic adenoma (CXPA): immunoprofile of the cells involved in carcinomatous progression.

AIMS: To characterize the cellular component in pleomorphic adenoma (PA) that undergoes malignant transformation in carcinoma ex pleomorphic adenoma (CXPA). METHODS AND RESULTS: A panel of antibodies against cytoskeletal proteins was applied in 16 cases of CXPA: intracapsular carcinoma (five cases), minimally invasive (four cases) and frankly invasive (seven cases). The CXPAs were classified into two main groups according to their predominant cellular component as detected by the panel of antibodies: (i) carcinomas with only epithelial differentiation (75% of the cases), and (ii) carcinomas with a myoepithelial component (25%). CXPA with only epithelial differentiation showed two types of malignant areas in the part of the tumour that was confined by the PA capsule: (i) intraductal carcinoma areas characterized by ductal structures containing both benign myoepithelial cells positive for alpha-smooth muscle actin (alpha-SMA), vimentin and cytokeratin (CK)14 and proliferating atypical luminal cells reactive for CK7, CK8 and CK19, and (ii) carcinoma areas composed only of epithelial cells reactive for CK7, CK8 and CK19. In the latter, the cells presented morphological and immunohistochemical characteristics similar to those found in areas of invasive carcinoma outside the PA capsule. CXPAs with a myoepithelial component were composed mainly or exclusively of cells that expressed vimentin and alpha-SMA. In this group, ductal structures reminiscent of PA filled by malignant cells were not identified. CONCLUSION: Most CXPAs consist only of epithelial cells that have an immunoprofile comparable to ductal luminal cells of PA. These malignant luminal cells arise in the duct-like structures as intraductal carcinoma and probably only at this early stage of development should the lesion be considered as a non-invasive carcinoma.

Actins↗
PubMed2003

Salivary gland tumours: immunoexpression of integrins beta 1, beta 3 and beta 4.

BACKGROUND: Integrins, heterodimeric transmembranic adhesion molecules composed of alpha and beta subunits, have been implicated in normal and neoplastic biological processes. We investigated the patterns of expression of integrins subunits beta 1, beta 3 and beta 4 in neoplasms derived from the terminal segment of salivary glands in order to understand their expression patterns in the different structures of these tumours. METHODS: Immunohistochemistry using 'catalized signal amplification' (CSA) detection system was applied to paraffin-embedded specimens of polymorphous low-grade adenocarcinoma, adenoid cystic carcinoma and acinic cell carcinoma. Normal salivary glands were used as controls. RESULTS: Immunoexpression of integrins showed that neoplastic structures of the tumours studied tend to mimic the patterns seen in the normal structures of salivary glands from which they are derived. Anaplastic cells were negative for all integrins. CONCLUSIONS: This study revealed detailed topography of integrins in malignant tumours derived from intercalated acinar segment of salivary gland and this might be useful in the diagnosis of these lesions, especially of fine-needle aspiration (FNA) products or small specimens derived form incisional biopsies.

Adenocarcinoma↗
PubMed2002

Immunohistochemical distinction of high-grade mucoepidermoid carcinoma and epidermoid carcinoma of the parotid region.

The correct diagnosis of high-grade mucoepidermoid (MEC), which is composed of solid islands of intermediate and squamous cells, may be challenging, due to its similarity to other tumours, mainly with squamous cell carcinoma (SCC). The present report employed immunohistochemical technique against different cytokeratins (CKs), in order to differentiate these two entities. : Six high-grade MEC and six SCC of the parotid region, retrieved from the files of both Oral Pathology Department of the School of Dentistry of University of São Paulo and Pathology Department of A.C. Camargo Hospital, were submitted immunohistochemical technique against Cks 7,8, 10, 13, 14 and 19. : High-grade MEC was positive for Cks 7, 8, 13, 14 and 19. The cases of SCC showed strong positivity for CK14, and CK10 was present only in focal areas. Our results highlight the use of CKs (especially CK14) to differentiate high-grade MEC and SCC.

Adult↗
PubMed2001

Effect of N-CAM on in vitro invasion of human adenoid cystic carcinoma cells.

Adenoid cystic carcinoma of salivary glands is characterised by aggressive behaviour, high rate of local recurrences, neurotropism and late metastasis. In a previous work we demonstrated that adenoid cystic carcinoma cultured cells (CAC2 cells) expressed N-CAM. It was suggested that this expression, modulated by extracellular matrix, would be correlated to cell movement. The aim of our study was to verify whether CAC2 cells presented invasion capacity. Moreover, we tested whether the neural adhesion molecule (N-CAM) would participate in this process. CAC2 cells were either previously treated, or not (control), with a monoclonal antibody against N-CAM. Invasion assays were carried out using a modified Boyden chamber (Transwell chamber). CAC2 cells (10(5)) were dispensed into Transwell upper chamber on the top of Matrigel coated filter. The cells that invaded the filters in the first 8 h were counted under light microscopy, yielding data for the invasion rates (%). Control CAC2 cells presented an invasion rate of 5.28+/-0.04%. The invasion rate raised to 6.53+/-0.2% when N-CAM was blocked with monoclonal antibody. N-CAM impaired the adenoid cystic carcinoma cell invasion in vitro. Therefore, we suggest an anti-invasive role for N-CAM in adenoid cystic carcinoma.

Analysis of Variance↗
PubMed2001

The cribriform features of adenoid cystic carcinoma and polymorphous low-grade adenocarcinoma: cytokeratin and integrin expression.

Cribriform areas are common features of both adenoid cystic carcinoma and polymorphous low-grade adenocarcinoma. Both are malignant salivary gland tumors that share similar histologic patterns, but with marked distinct clinical behavior. This study was undertaken to improve the accuracy of the histopathology diagnostic process, using an immunohistochemical panel to differentiate adenoid cystic carcinoma from polymorphous low-grade adenocarcinoma, with special concern to the common cribriform areas shared by these tumors. Three-microm serial sections of these tumors were submitted to the streptavidin-biotin peroxidase immunotechnique against the monoclonal antibodies anticytokeratins 7, 8, 14 and 19, and anti-integrins beta1, beta3, and beta4. In the neoplastic lobules of adenoid cystic carcinoma cribriform type, the spaces were mainly surrounded by cells negative for the cytokeratins and integrins studied. In the solid type of adenoid cystic carcinoma, the microcystic areas were caused by spaces lined by neoplastic luminal cells positive for cytokeratins and presenting integrins concentrated in the apical pole of these cells. The cribriform areas of polymorphous low-grade adenocarcinoma were composed of cords of luminal cells, positive for cytokeratins and showing integrins disposed in a bipolar pattern. We concluded that cribriform areas of adenoid cystic carcinoma and polymorphous low-grade adenocarcinoma are histologically similar, although not identical. Indeed, their cellular composition is distinct and can be distinguishable from one another by the proteins of the cytoskeleton, by the integrins, or both.

Adenocarcinoma↗
PubMed2001

Langerhans cell histiocytosis: recurrent lesions affecting mandible in a 10-year-old patient.

Hand-Schuller-Christian disease is a multifocal variant of eosinophilic granuloma, characterised by the classical triad of bony lesions, exophthalmos and diabetes insipidus. This case relates recurrent Langerhans' cell histiocytosis lesions presented as destruction of periodontal support associated with diabetes in a 10-year-old patient. Medical history suggests that the case represents a case of Hand-Schuller Christian disease.

Alveolar Bone Loss↗
PubMed2000

The role of basement membrane proteins on the expression of neural cell adhesion molecule (N-CAM) in an adenoid cystic carcinoma cell line.

We investigated the presence of neural cell adhesion molecule (N-CAM) in the adenoid cystic carcinoma cell line CAC2 using immunofluorescence microscopy. Additionally, we analysed the role of laminin and type IV collagen in N-CAM expression. We demonstrated that cultured adenoid cystic carcinoma cells express N-CAM. Control cells presented a scattered N-CAM expression on cell membrane, and type IV collagen had no effect in N-CAM distribution. CAC2 cells grown on laminin-coated coverslips expressed N-CAM concentrated on cell lamellipodia suggesting relationship with migratory activity. Our results showed that cultured adenoid cystic carcinoma cells express N-CAM and this expression is modulated by extracellular matrix.

Carcinoma, Adenoid Cystic↗
PubMed2000

Expression of cytokeratins in human enamel organ.

Cytokeratin (CK) is a filament which plays a central role in epithelial tissue and, like the polypeptides of intermediate filaments in general, shows a high degree of tissue specificity. The CK expression patterns of odontogenic epithelia are still poorly described. We studied the distribution of individual CK polypeptides in the human enamel organ at bell stage and in remnants of the dental lamina. Our immunohistochemical study showed that epithelial cells stained for CKs 7, 13, 14 and 19 with slight changes in their pattern during the differentiation phase of odontogenesis. There was negative staining for all other CK polypeptides tested (CKs 8, 10, 16, 17 and 18). Most of the CKs in the enamel organ epithelia did not show differences related to the stage-specific state of differentiation, except for CKs 14 and 19 at the inner enamel epithelium. A strong label for CK 14 was present at the inner dental epithelium at early bell stage, and this was substituted by CK 19 at the late bell stage when the ameloblasts were fully differentiated.

Ameloblasts↗
PubMed2000

Polymorphous low-grade adenocarcinoma and adenoid cystic carcinoma: distinct architectural composition revealed by collagen IV, laminin and their integrin ligands (alpha2beta1 and alpha3beta1).

AIMS: Polymorphous low-grade adenocarcinoma (PLGA) and adenoid cystic carcinoma (ACC) are malignant salivary gland tumours bearing many similar histological patterns. This study was undertaken to show how the presence and distribution of collagen IV and laminin, and their ligands (integrin alpha2beta1 and alpha3beta1 components), can reveal histoarchitectural differences which distinguish these two entities. METHODS AND RESULTS: Five cases of ACC and five cases of PLGA from the archives of the Oral Pathology Department of the School of Dentistry of the São Paulo University were submitted to immunostaining with the antibodies to collagen IV, laminin, and integrins alpha2beta1 and alpha3beta1 using the streptavidin-biotin-peroxidase technique. Positive and negative controls were included. PLGA showed a thin line of collagen IV and laminin surrounding structures composed of a single cell layer. Integrins were expressed as a widespread and granular pattern. A thick line of collagen and laminin was observed around the neoplastic structures of ACC. Both integrins were expressed in intercellular spaces and around luminal spaces of tubular structures. CONCLUSIONS: Collagen IV and laminin, and their integrin ligands, are useful in demonstrating that neoplastic ductal units of PLGA are composed of a single cell layer, being distinct from ACC which contains structures composed of two layers of neoplastic cells.

Adenocarcinoma↗
PubMed1999

Extranodal follicular dendritic cell sarcoma of the palate.

Follicular dendritic cell tumors are uncommon and usually occur in lymph nodes. We report the case of a follicular dendritic cell tumor that occurred in the palate of a 14-year-old boy and manifested itself as a nodular mass. Histologically, the neoplasm consisted of spindle-shaped or oval-shaped cells with eosinophilic cytoplasms and nuclei with delicate, dispersed chromatin. The lesional cells were principally arranged in diffuse, fascicular patterns with vaguely whorled or storiform areas. Focal multinucleate tumor giant cells and lymphocytes were observed throughout the neoplasm. Immunohistochemically, tumor cells were positive for the follicular dendritic cell markers CD21, CD35, and CD23 and for S-100 protein, CD68, and muscle-specific actin. Tumor cells were negative for LCA, CD20, EMA, CK (AE1/AE3), HMB45, and CD34. Lymphocytes were positive for LCA and CD45RO. Although follicular dendritic cell sarcoma is a very uncommon tumor, it should be included in the differential diagnosis of tumors in this location.

Adolescent↗
PubMed1999

Intraosseous leiomyoma of the mandible.

An intraosseous leiomyoma arising within the mandible was diagnosed in a 24-year-old woman. Clinically, a nodular swelling of the lower border of the mandible was noted. Radiographically, a unilocular ellipsoid radiolucency, loss of the lower border of the mandible, and tooth resorption were observed. The mitotic count was 0.4 per 10 high-power fields, which supported the benign nature of the tumor. The clinical and histologic parameters for distinguishing between benign and malignant smooth muscle neoplasms are discussed.

Adult↗
PubMed1998

Healing of the displaced condylar process fracture: an experimental study.

Healing of the displaced condylar process fracture was analysed by means of an experimental model using adults rats. Displaced fractures of the right condylar process were achieved under general anaesthesia. Histological data initially demonstrated neutrophilic exudation along the articular capsule and adjacent muscle fibres. One week later, devitalized bone areas at the fracture site, as well as proliferation of cartilaginous and osseous tissue were observed. Subsequently, exuberant callus formation and a decrease in the inflammatory process occurred. After 3 months, the condylar process presented characteristics of normality and was centralized into the temporal fossa, with interposition of the articular disc. These results indicate that experimentally induced, displaced condylar process fractures heal by callus formation with simultaneous repositioning of the condyle.

Animals↗
PubMed1998

Study of minor salivary gland mucoepidermoid carcinoma differentiation based on immunohistochemical expression of cytokeratins, vimentin and muscle-specific actin.

The expression of cytokeratins (CKs) 7,8,10,13,14,18,19, vimentin and muscle-specific actin (MSA) was investigated in 17 mucoepidermoid carcinomas (MEC) by the streptavidin-biotin technique. The results revealed that CKs 7, 8 and 18 were positive for intermediate, luminal columnar and mucous cells. For epidermoid cells, the expression was heterogeneous and discrete. The reaction with CK19 was similar to that seen for the above CKs, except for the fact that mucous cells were negative. CK 14 was preferentially expressed in the intermediate cells localised in basal, parabasal and epidermoid cells. CK13 was localised in intermediate, epidermoid and luminal columnar cells. In stratified epithelium, CK13 was expressed in intermediate cells and negative in basal cells. These findings were more expressive in cystic areas of the tumours. CK10 was negative for all the cases studied. MSA was positive only in stromal elements, and only two cases of CME were heterogeneously positive for vimentin. The result obtained showed that the immunoprofile of MEC, for the studied antigens, is similar to that exhibited by the excretory duct of normal salivary glands.

Actins↗
PubMed1997

CD30+ lymphocytes in chronic gingivitis from HIV-positive patients: a pilot study.

Th2 type lymphocytes are characterized by high expression of CD30 glycoprotein. Increased serum levels of CD30 and Th2 IL-4 producing T-cells are found during AIDS progression. Since HIV-positive patients are more susceptible to periodontal disease, quantitative analysis of positive cells for the CD30 receptor in chronic gingivitis of both HIV-infected and non-infected patients (NSG) would help to clarify the immunoregulation of HIV-associated periodontal diseases. The purpose of this study was to evaluate CD30+ lymphocytes in gingival biopsies from sites exhibiting chronic gingivitis on HIV-positive patients (CG-HIV) and NSG. A biotin-streptavidin amplified system was used for identification of the CD30 receptor. The results demonstrated increased proportions of Th2 cells in CG-HIV as compared to NSG. Additional studies are necessary to understand the importance of these cells to the biological activity or inactivity of the disease.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Argyrophilia in nucleolar organizer regions (AgNOR) in adenoid cystic carcinoma and polymorphous low-grade adenocarcinoma of the salivary glands.

Nine cases of adenoid cystic carcinomas (ACC) and three cases of polymorphous low-grade adenocarcinomas (PLGA) of the salivary glands from the Surgical Oral Pathology Service of the University of São Paulo School of Dentistry were examined by means of the silver-staining nucleolar organizer regions (AgNOR) technique. Quantitative and dimensional analyses of NORs were carried out. Our findings suggest that solid and cribriform patterns of ACC have a higher cellular activity than that presented by tubular ACC and PLGA.

Adenocarcinoma↗
PubMed1984

The use of subcutaneously implanted araldite disks for microstructural studies of inflammatory macrophages.

Subcutaneously implanted epoxy resin disks can be used instead of glass coverslips in mice to recruit inflammatory macrophages. Implanted araldite disks exhibited large numbers of macrophages on both surfaces which could be observed conveniently by light and phase contrast microscopy. Most importantly, the disks can be embedded directly in an araldite mixture for the preparation of thin sections for electron microscope examination.

Animals↗