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.

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.

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.

Do whole-body vibration exercise and resistance exercise modify concentrations of salivary cortisol and immunoglobulin A?

A single bout of resistance exercise (RE) induces hormonal and immune responses, playing an important role in a long-term adaptive process. Whole-body vibration (WBV) has also been shown to affect hormonal responses. Evidence suggests that combining WBV with RE may amplify hormonal and immune responses due to the increased neuromuscular load. Therefore, the aim of this study was to evaluate salivary cortisol (Scortisol) and salivary IgA (SIgA) concentrations following a RE session combined or not with WBV. Nine university students (22.9 ± 5.1 years, 175.8 ± 5.2 cm, and 69.2 ± 7.3 kg) performed five sets of squat exercise (70 percent one-repetition-maximum) combined (R+V30) or not (R) with WBV at 30 Hz. Saliva samples were obtained before and after exercise. Subjects also rated their effort according to the Borg CR-10 scale (RPE). Data were analyzed by a mixed model. RPE was higher after R+V30 (8.3 ± 0.7) compared to R (6.2 ± 0.7). However, Scortisol (pre: 10.6 ± 7.6 and 11.7 ± 7.6, post: 8.3 ± 6.3 and 10.2 ± 7.2 ng/mL for R and R+V30, respectively) and SIgA concentrations (pre: 98.3 ± 22.6 and 116.1 ± 51.2, post: 116.6 ± 64.7 and 143.6 ± 80.5 µg/mL for R and R+V30, respectively) were unaffected. No significant correlations were observed between Scortisol and RPE (r = 0.45, P = 0.22; r = 0.30, P = 0.42, for R and R+V30, respectively). On the basis of these data, neither protocol modified salivary cortisol or IgA, although RPE was higher after R+V30 than R.

Do whole-body vibration exercise and resistance exercise modify concentrations of salivary cortisol and immunoglobulin A?

A single bout of resistance exercise (RE) induces hormonal and immune responses, playing an important role in a long-term adaptive process. Whole-body vibration (WBV) has also been shown to affect hormonal responses. Evidence suggests that combining WBV with RE may amplify hormonal and immune responses due to the increased neuromuscular load. Therefore, the aim of this study was to evaluate salivary cortisol (Scortisol) and salivary IgA (SIgA) concentrations following a RE session combined or not with WBV. Nine university students (22.9 ± 5.1 years, 175.8 ± 5.2 cm, and 69.2 ± 7.3 kg) performed five sets of squat exercise (70% one-repetition-maximum) combined (R+V30) or not (R) with WBV at 30 Hz. Saliva samples were obtained before and after exercise. Subjects also rated their effort according to the Borg CR-10 scale (RPE). Data were analyzed by a mixed model. RPE was higher after R+V30 (8.3 ± 0.7) compared to R (6.2 ± 0.7). However, Scortisol (pre: 10.6 ± 7.6 and 11.7 ± 7.6, post: 8.3 ± 6.3 and 10.2 ± 7.2 ng/mL for R and R+V30, respectively) and SIgA concentrations (pre: 98.3 ± 22.6 and 116.1 ± 51.2, post: 116.6 ± 64.7 and 143.6 ± 80.5 µg/mL for R and R+V30, respectively) were unaffected. No significant correlations were observed between Scortisol and RPE (r = 0.45, P = 0.22; r = 0.30, P = 0.42, for R and R+V30, respectively). On the basis of these data, neither protocol modified salivary cortisol or IgA, although RPE was higher after R+V30 than R.

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.

High-grade transformation of adenoid cystic carcinomas: a study of the expression of GLUT1 glucose transporter and of mitochondrial antigen.

AIMS: To broaden understanding of phenomena involved in progression from classical adenoid cystic carcinomas (ACCs) to tumours with high-grade transformation (ACC-HGT) METHODS: Expression of proteins linked to cellular metabolism as well as the microvascular density (MVD) in conventional and transformed areas were analysed. Findings were compared with ordinary ACCs. In seven cases of ACC-HGT and in 18 ACCs the expressions of GLUT1, mitochondrial antigen (MTA), CD34 (for assessing MVD), alpha-SMA and P63 (for detection of myoepithelial cells) and Ki-67 (for evaluation of proliferation index) were examined. RESULTS: The transformed component corresponded to adenocarcinomas with frequent (four cases) or scarce/absent (three cases) gland differentiation. In the latter, Ki-67 index was higher, two patients presented lymphatic metastasis and one died of disease. In the former, there was one long-term survivor and one with liver metastasis. Conventional areas of both ACC-HGT and ACC were negative for GLUT1 in most cases (83.3% and 81.3%, respectively) and exhibited low or no expression of MTA (100% and 66.7% of cases, respectively). In contrast, the HGT component presented increased expression of both proteins (GLUT1+ in 50% of cases; MTA+ in 100%). However, the degree of GLUT1 expression did not correlate with clinical outcome. MVD did not differ significantly between conventional and transformed components. CONCLUSIONS: Transformation of classical ACC into ACC-HGT encompasses adenocarcinomas with variable degrees of differentiation and seems to lead to metabolic changes without reflection in tumour vasculature. Despite the tumours' higher GLUT1 expression, this protein has no utility as a prognostic marker.

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.

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.

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.

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.

Histological evaluation of the osteoinduction capability of human dentine.

Aim To assess whether human dentine has the potential to promote the development of calcified tissues when implanted in the muscle tissue of mice. Methodology Root canals in extracted human teeth were instrumented to produce dentine fragments. The dentine fragments produced were divided into two. In group 1, fragments were demineralized and sterilized. In group 2, the fragments were not submitted to any additional treatment. The dentine fragments were then implanted in the muscle of mice. In group 3, the muscles were implanted with rehydrated lyophilized human bone powder. Animals were killed following test periods of 7, 15, 30, 60, 120 and 180 days, the fragments were removed together with adjacent muscle and examined under light microscopy to assess calcification. Results Areas of calcification were observed in groups 1 and 3 after a period of 180 days. In group 2, the surrounding tissues displayed only chronic inflammatory infiltration. Conclusions On the basis of the experimental model adopted in this study, fibroblast-rich connective tissue formed in groups 1 and 3, which could reflect an osteoinductive process. Further studies are suggested to identify which dentinal factors are capable of inducing the formation of a calcified matrix.

Polymorphous low grade adenocarcinoma presenting an uncommon radiographic aspect.

The aim of this study was to present clinical, histological and immunohistochemical aspects of a polymorphous low grade adenocarcinoma occurring in the mandible. A radiolucent tumour, located in the right mandible, was removed from a 40-year-old woman. Radiographic and CT exams revealed that the lesion expanded bucco-lingual cortical plates and presented an irregular scalloping of the bone. The surrounding lining mucosa was intact. The patient underwent total surgical removal of the lesion with an intraoperative biopsy. Histological diagnosis was polymorphous low-grade adenocarcinoma confirmed by immunohistochemical study. One-year follow up was uneventful. The accurate diagnosis of lesions presenting unusual clinical aspects, as the one presented here, is critical for correctly handling treatment.

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.

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.

In vitro immunoexpression of extracellular matrix proteins in dental pulpal and gingival human fibroblasts.

AIM: To compare the expression of extracellular matrix (ECM) components in human pulpal and gingival fibroblasts in vitro. METHODOLOGY: Cultured dental pulp fibroblasts and gingival mucosa fibroblasts were used. Tenascin (TN), fibronectin (FN), type I (col I) and III collagen (col III) and osteonectin (ONEC) were detected by immunofluorescence. Main morphological characteristics were also analysed by light microscopy (LM) and transmission electron microscopy. RESULTS: The results revealed different expression patterns of the proteins. TN and ONEC were only immunoexpressed by pulpal fibroblast cells, suggesting a role of these glycoproteins in formation of mineralized tissues. FN and col I were present in the cytoplasms of both cell types. No expression of col III was detected. Different morphological characteristics were visualized under LM, in which pulpal fibroblasts were spindle-shaped with a wide cytoplasm, while gingival fibroblast cells exhibited stellate/pyramidal configuration, with rounded nuclei. However, ultrastructurally, both cell lineages showed very well developed rough endoplasmatic reticulum and Golgi complex. CONCLUSIONS: Due to the immunodetection of TN and ONEC on pulpal fibroblasts, the present findings demonstrated that a pulpal fibroblast cell is similar to an osteoblastic cell rather than an undifferentiated mesenchymal cell, such as a gingival fibroblast cell. Functional differences between the two cell lines may then be suggested.

Expression patterns of integrins on pleomorphic adenoma and adenoid cystic carcinoma: study on specimens and in vitro investigation of the effects of extracellular matrix on the expression of these adhesion molecules.

BACKGROUND: Pleomorphic adenoma (PA) and adenoid cystic carcinoma (ACC) are neoplasms of distinct behaviour, showing similar origin, cell components and marked presence of extracellular matrix (ECM). Interactions between cells and ECM are important in the biology of tumours, being partially mediated by integrins. This study investigated these interactions on PA and ACC using paraffin-embedded tissue and an in vitro model of these conditions. METHODS: Expression of integrins in paraffin-embedded samples was assessed by immunohistochemistry. Cells from PA and ACC were characterized using immunofluorescence, and integrin patterns of expression were investigated on cells cultivated on different ECM proteins. RESULTS: Luminal cells of both PA and ACC were more intensely positive for integrins than myoepithelial cells. In vitro studies revealed that PA cells expressed more integrins than ACC cells regardless the ECM protein present. CONCLUSIONS: This study revealed particular patterns of integrin expression in both specimens and in vitro models of PA and ACC. This might prove useful for a better understanding of the biology of these lesions.