Endoglin is Highly Expressed in Human Mast Cells.

Endoglin, known to be expressed in proliferating vessels, is of worth when evaluating microvessel density as a prognostic factor in many types of malignancies, including some subtypes of leukemia cells. In childhood acute lymphoblastic leukemia, endoglin is associated with adverse outcome. In bone marrow, endoglin identifies the repopulating hematopoietic stem cells. Mast cells are a component of normal tissue and play an important role in the regulation of several processes, including inflammation and neoplasia. The aim of this study was to evaluate the use of endoglin as a biological marker of mast cells compared with the gold standard stains. We studied 15 specimens of neurofibroma, 9 of mastocytosis, and 6 of fibrous scar tissue through immunohistochemistry (for endoglin and mast cell tryptase) and histochemical staining using toluidine blue. Quantitative analysis of the cells was performed by counting 5 hotspots. The validity of endoglin as a mast cell marker was assessed by intraclass correlation coefficient. The Kruskal-Wallis test was used to compare mast cell count for each marker. A strong endoglin expression was found in the cytoplasmic granules of mast cells within the 3 groups. Similar results were observed with mast cell tryptase as well as toluidine blue. The intraclass correlation coefficient revealed that endoglin is a highly reliable biomarker of mast cells when compared with mast cell tryptase and toluidine blue. In conclusion, endoglin may assist in the diagnosis and pathogenesis study of various processes associated with mast cells. An endoglin-neutralizing treatment for solid cancers and leukemia could also affect mastocytes and the immunologic system.

Prevalence of oral lesions in hospitalized patients with infectious diseases in northern Brazil.

The aim of this study was to assess the prevalence of oral lesions in infectious-contagious diseases patients being treated in the University Hospital of the Federal University of Pará, northern Brazil. One hundred seven patients with infectious diseases were clinically investigated for oral lesions at the University Hospital of Pará, northern Brazil. From total sample, most patients were men (65.7%) with a mean age of 45.4 years. About prevalence of systemic diseases, tuberculosis was the most frequent illness, followed by AIDS, hepatitis types B and C, leishmaniasis, and meningitis. Analyzing oral manifestations, periodontal diseases and candidiasis were the most prevalent diseases in both genders, followed by recurrent aphthous ulcers, saburral tongue, simplex herpes, and squamous cell carcinoma. Of all 107 patients, only 10 males and 6 females did not present any oral manifestation. There was no statistical difference between genders with any systemic condition (P>0.05). The great prevalence of oral manifestations in hospitalized patients with systemic disorder emphasizes the need of integral dental care in this context, aiming at a multidisciplinary approach of patients. Therefore, presence of some oral conditions, such as candidiasis, should be an alert to different systemic conditions, once in assistance with physicians; dentists can influence the early diagnosis and treatment.

Malignancy-related 67kDa laminin receptor in adenoid cystic carcinoma. Effect on migration and beta-catenin expression.

Adenoid cystic carcinoma is a malignant salivary gland neoplasm with recurrence and metastasis. We studied the expression of a malignancy-related non-integrin laminin receptor, the 67LR, in this neoplasm. Immunohistochemistry showed 67LR in adenoid cystic carcinoma. This receptor binds a sequence of laminin beta1 chain, the YIGSR peptide. We studied the effect of 67LR and YIGSR in cells (CAC2) from adenoid cystic carcinoma. Three-dimensional cultures of cells embedded into either laminin-111 gel (controls) or YIGSR-enriched laminin-111 (treated) were prepared and studied by light microscopy. CAC2 cells treated with YIGSR appeared fibroblast-like, while control cells were epithelioid. Blockage of 67LR by antibody abolished YIGSR effect in three-dimensional cultures. We analysed the relevance of 67LR and YIGSR on beta-catenin expression in CAC2 cells. Immunofluorescence and immunoblot showed that YIGSR decreased beta-catenin, while blockage of 67LR restored the presence of this molecule. The 67LR and YIGSR induced fibroblast-like morphology in CAC2 cells, with disruption of cell-cell contacts and decrease of beta-catenin. These features resemble epithelial-mesenchymal transition (EMT). EMT also increases cell migration. In monolayer assays YIGSR increased migration of CAC2 cells. We conclude that 67LR and YIGSR are involved in epithelial-mesenchymal transition, modulation of beta-catenin expression, and migratory activity of CAC2 cells.

Influence of rubber dam isolation on human pulp responses after capping with calcium hydroxide and an adhesive system.

OBJECTIVE: The objective was to evaluate the influence of rubber dam isolation on the response of human pulps capped with calcium hydroxide and an adhesive system. METHODS AND MATERIALS: Direct pulp capping was performed in 40 caries-free human premolars scheduled for extraction as part of orthodontic treatment. The teeth were randomly divided into 8 groups (n = 5) according to the combination of treatment factors: capping agent (adhesive resin or calcium hydroxide), isolation (rubber dam or cotton pellets only), and period of evaluation (30 or 60 days). Class 2 cavities were prepared, and pulp exposures were created on the occlusal floor. After capping, all teeth were restored with Z-100 placed incrementally. After 30 or 60 days, patients were asked about their symptoms, teeth were extracted, and serial sections were evaluated. The data were subjected to a nonparametric test. RESULTS: Overall, the histologic features showed that the pulp response was worse for groups capped with adhesive. For adhesive-capped groups, the pulp response varied from pulp necrosis to acute inflammatory cell infiltrate, and most of the pulps capped without rubber dam isolation showed severe inflammatory cell infiltrate involving the coronal pulp with chronic abscesses. For the calcium hydroxide groups, all specimens showed dentin bridge formation, regardless of the type of isolation used. CONCLUSION: Calcium hydroxide should be used as the material of choice for pulp capping with or without rubber dam isolation. The use of adhesive systems in vital pulp capping is contraindicated, especially if rubber dam isolation is not implemented.

Comparative immunoprofile of polymorphous low-grade adenocarcinoma and canalicular adenoma.

Immunohistochemistry is an important tool when dealing with salivary gland neoplasms. Canalicular adenoma and polymorphous low-grade adenocarcinoma may share some histologic characteristics that can cause difficulties in their separation. In the present study, cases of polymorphous low-grade adenocarcinoma and canalicular adenoma were submitted to a panel of antibodies to evaluate the differences in their immunoprofiles. The results obtained showed that, while vimentin is only expressed by polymorphous low-grade adenocarcinoma, CK7 and CK8 are present in both neoplasms. Therefore, vimentin is the best marker to differentiate between these tumors.

Expression of cytoskeletal proteins in developing human minor salivary glands.

The presence of an epithelium at different stages of proliferation and differentiation raises interesting questions concerning the histogenesis, cell turnover and differentiation of normal salivary glands. In order to expand knowledge of these aspects, we investigated the expression of cytokeratins (CKs) 7,8,10,13,14,16,18 and 19, vimentin (VIM), and smooth muscle actin (SMA) in developing human minor salivary glands using monoclonal antibodies. Labial, buccal, palatine, and lingual salivary glands and those from the floor of the mouth were obtained from human fetuses (forensic postmortem) ranging in age from gestational weeks 10 to 29. Serial sections, 3 microm thick, were immunostained using a strepto-avidin-biotin technique. Reactivity for all antibodies was negative in the salivary gland epithelium during the developmental stages of bud formation, cord growth, and branching of cord. During canalization and cytodifferentiation, the glandular epithelial cells showed a positive reaction to some CKs and SMA. Cytokeratins 7, 8, 18, and 19 showed strong labeling in luminal duct cells that exhibited some degree of morphological differentiation. Myoepithelial cellc were recognized by antibodies to SMA. Cytoskeletal protein expression changes according to the cell type, degree of differentiation, and stage of morphological development of the glandular structure. These changes occur independently of the localization of the gland.