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.

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.

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.

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.

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.

Well-differentiated liposarcoma of the tongue.

Intraoral liposarcomas are rare, with most reported cases being of the myxoid histological type. We present a well-differentiated liposarcoma of the tongue, in a 65-year-old man. The tumour presented lipoblasts in various stages of differentiation, lipocytes in different sizes and shapes, mesenchymal and signet-ring cells. Lipoma, spindle-cell lipoma, myxoma, hibernoma, angiolipoma, fibrolipoma, pseudosarcomatous faciitis and malignant hysticytoma were considered in the diagnosis process. The patient was treated surgically and so far is free of disease.

p53 In biopsies of oral squamous cell carcinoma. A comparative study with a malignancy grading system.

The relationship between the histological grading of malignancy and p53 protein expression was studied in 40 biopsies of oral squamous cell carcinomas. An immunohistochemical analysis was carried out using the streptavidin method preceded by a treatment with citric acid in a microwave oven. All cases were classified according to the histological malignancy grading system proposed by Anneroth et al. (Scandinavian Journal of Dental Research 1987, 95, 229-249). The expression of p53 was found in 62.5% of the carcinomas studied. Positivity of p53 staining showed a correlation with the histological grade of malignancy and with the degree of keratinisation, nuclear polymorphism and number of mitoses.

Immunohistochemical Mdm2 expression in minor salivary gland tumours and its relationship to p53 gene status.

Mdm2 protein is a cellular regulator of p53 protein activity. Minor salivary gland tumours were investigated for immunohistochemical expression of Mdm2 protein and for p53 gene status. Formalin-fixed sections were submitted to monoclonal antibody anti-Mdm2 through use of the streptavidin-biotin method. Nuclear immunoreactivity was scored 1 (0-25% nuclei positive), 2 (26-50%), 3 (51-75%) and 4 (> 75%). The scores found were: PLGA = 1-4; ACC = 3 and 4; ACA = 2 and 4; PA = 3. Genomic DNA of p53 gene exons 5-8 was examined by polymerase chain reaction and no alterations were detected. The strong immunohistochemical Mdm2 expression may represent an alternative mechanism to the development of salivary gland tumours.

Immunohistochemical study of apical periodontal cysts.

Periapical lesions, as well as periodontal disease, seems to have cyclic patterns of evolution. Periods of burst may be intercalated with periods of quiescence. Because keratinocyte division must occur during cyst growth, it is presumed that epithelium status could indicate the biological activity of radicular cysts (RCs). Th1 and Th2 are important heterogeneous stages of lymphocyte differentiation. Delayed-type hypersensitivity immune reactions are mediated by Th1 lymphocytes, whereas Th2 populations mediate some types of humoral immune response. Th2 lymphocytes are characterized by high expression of CD30 glycoprotein. Th1 and Th2 lymphocytes have not been evaluated in periapical inflammatory lesions. The purpose of this study was to evaluate CD30+ cells in RCs with atrophic and hyperplastic epithelium. A biotin-streptavidin amplified system was used for identification of CD30 receptor. Results demonstrate increased proportions of Th2 cells in cysts with hyperplastic epithelium. Our results suggest that Th2 cells could be associated with RC growth.

Rotated subcondylar process fracture in the growing animal: an experimental study in rats.

Unilateral, rotated subcondylar fractures were surgically induced in young rats under general anaesthesia. A decrease in body weight was observed in the fractured animals, with recovery at the end of the experimental period. A tendency of deviation of the mandible to the fracture side was noticed on axial radiographs, but without significant difference between experimental and sham-operated animals. Histological data initially demonstrated acute inflammation along the articular capsule and adjacent muscle fibres. Within 2 weeks, exuberant callus formation occurred. Neither devitalized bone ends nor intra-articular granulation tissue were seen. After 1 month, the temporomandibular joint presented characteristics of normality, with the condylar process centralized into the temporal fossa, interposed by the articular disc. These results were preserved after 3 months. We concluded that rotational subcondylar fractures in young rats heal by callus formation, with simultaneous and prompt repositioning of the condyle.

The effect of indirect trauma on the rat temporomandibular joint.

The effect of indirect trauma to the rat temporomandibular joint (TMJ) is analysed by means of an experimental model. The trauma, applied from an angle-glenoid fossa direction, produced injury of the TMJ. The histological data demonstrated that the impact could produce fractures of the glenoid fossa, but no hemarthrosis was observed. Trauma, both with or without fracture, caused proliferative changes in the TMJ. The glenoid fossa, the articular disk and the articular surface of the condyle were injured. Thickening of the articular surfaces had resulted in reduced joint space. Subsequently, remodelling changes in the condyle were found.

Sialadenoma papilliferum: immunohistochemical study.

Sialadenoma papilliferum (SP) is a rare benign tumour of salivary gland origin, which has been included among the ductal papillomas in the latest classification of tumours by the World Health Organisation. Two SP from the minor salivary gland of the palate of middle age patients were presented and studied by immunohistochemical. Our results showed presence of cytokeratins (CKs) 13, 14, 7, 8, 19 and absence of vimentin and smooth muscle actin. This immunoprofile is similar to the excretory duct of salivary gland.

Collagenous fibroma (desmoplastic fibroblastoma) of the palate: a case report.

Collagenous fibroma is an uncommon benign soft tissue lesion that has a wide anatomic distribution. We describe a case of a collagenous fibroma that appeared in the left soft and hard palate of a 37-year-old woman as a 5.0-cm solitary, firm nodule. Microscopically, it was composed of stellate or spindle-shaped cells embedded in hypovascular fibrous stroma. Entrapment of fat was focally identified at the edges. Mitotic figures and tumor necrosis were absent. Tumor cells were immunopositive for vimentin, and a few cells were positive for alpha-smooth muscle actin. Tumor extracellular matrix was immunopositive for type I and type III collagen, as well as for fibronectin. These findings satisfied the diagnostic criteria for collagenous fibroma (desmoplastic fibroblastoma). This case, to our knowledge, represents the first report of this tumor in the mouth. The differential diagnosis of fibrous lesions of the mouth is discussed.

Ultrastructural aspects of connective tissue in hereditary gingival fibromatosis.

OBJECTIVE: The purpose of this study was to analyze the ultrastructure of gingival connective tissue from patients in one family affected by hereditary gingival fibromatosis (HGF). STUDY DESIGN: Electron microscopic examination was performed with gingival tissue from 10 patients from a Brazilian family with 132 members. Fifty of 96 persons at risk for this disorder were affected, which is consistent with an autosomal dominant pattern of inheritance. RESULTS: The extracellular matrix showed flocculent material and collagen fibrils with structural abnormalities and variation in diameter. Increased numbers of oxytalan fibers were identified; however, elastic fibers were rare in the analyzed areas. CONCLUSIONS: The structural alterations found in HGF appear similar to those described in certain other heritable collagen disorders, suggesting that HGF should be included in the group of hereditary diseases in which connective tissue alterations have a distinct pattern, in contrast to reactive fibrotic gingival enlargements with no genetic component.

Clear-cell ameloblastoma (clear-cell odontogenic carcinoma): report of a case.

Clear-cell ameloblastoma (clear-cell odontogenic carcinoma) is an uncommon odontogenic epithelial neoplasm. We report a case of a well-circumscribed 2 cm radiolucent lesion of the anterior mandible in a 30-year-old woman; this tumor was curetted. The first recurrence (at 5-year follow-up) was treated by aggressive curettage, and in the second recurrence a block resection was performed. However, 2 years after the resection was performed, the tumor recurred for a third time as an extraosseous gingival tumor, and 6 months later a recurrence was noted involving only alveolar mucosa.

Glandular odontogenic cyst: report of a case with cytokeratin expression.

The glandular odontogenic cyst is a rare lesion that was recognized as a distinct entity in the latest WHO typing of odontogenic tumors. We report a glandular odontogenic cyst that recurred after surgical removal from the anterior mandible of a 54-year-old white man. Immunohistochemical study showed that the cystic epithelium reacted positively to antibodies directed against cytokeratins (CKs) 7, 13, 14, and 19 and negatively to CKs 8 and 18.

Expression of smooth-muscle actin in cultured cells from human plasmacytoid myoepithelioma.

OBJECTIVE: The definition of plasmacytoid myoepithelioma, a neoplasm exhibiting myoepithelial differentiation, has been recently questioned. To better understand the histogenesis of this neoplasm, we searched for myoepithelial markers in histologic sections of plasmacytoid myoepithelioma and in a cell line (M1) derived from this same neoplasm. STUDY DESIGN: Expression of vimentin, pan-keratin (AE-3) and smooth-muscle actin was studied by immunohistochemistry in paraffin-embedded tissue and by immunofluorescence in M1 cells. RESULTS: Plasmacytoid myoepithelioma tumor sections showed vimentin and AE-3 reactivity, but evidence of smooth-muscle actin was not seen. The cell line derived from this tumor also produced vimentin and cytokeratin. In addition, all cultured cells expressed smooth-muscle actin. CONCLUSION: We demonstrated that cells derived from a case of plasmacytoid myoepithelioma appear to show full myoepithelial differentiation in vitro. Thus, they are myoepithelial-like cells in nature. The lack of myogenous differentiation in vivo could be due to an inhibitory process mediated by the extracellular matrix.

Botryoid odontogenic cyst: report of a case with clinical and histogenetic considerations.

A case of a botryoid odontogenic cyst is reported. Some considerations regarding histogenetic and biologic behaviour of the lesion are discussed.