Multigap Superconductivity in Y2_2C3_3: A 13^{13}C-NMR Study

We report on the superconducting (SC) properties of Y$_2$C$_3$ with a relatively high transition temperature $T_{\rm c}=15.7$ K investigated by $^{13}$C nuclear-magnetic-resonance (NMR) measurements under a magnetic field. The $^{13}$C Knight shift has revealed a significant decrease below $T_{\rm c}$, suggesting a spin-singlet superconductivity. From an analysis of the temperature dependence of the nuclear spin-lattice relaxation rate $1/T_1$ in the SC state, Y$_2$C$_3$ is demonstrated to be a multigap superconductor that exhibits a large gap $2\Delta/k_{\rm B}T_{\rm c}=5$ at the main band and a small gap $2\Delta/k_{\rm B}T_{\rm c}=2$ at other bands. These results have revealed that Y$_2$C$_3$ is a unique multigap s-wave superconductor similar to MgB$_2$.Comment: 4 pages, 5 figure

Immunohistochemical expression of matrilysins (MMP-7 and MMP-26) in ameloblastomas and adenomatoid odontogenic tumors

OBJECTIVE: The aim was to evaluate the expression of matrix metalloproteinases (MMPs) 7 and 26 in ameloblastomas and adenomatoid odontogenic tumors (AOTs). STUDY DESIGN: Twenty intraosseous solid ameloblastomas and 10 intraosseous AOTs were evaluated regarding immunohistochemical expression of MMP-7 and -26 in the epithelium and stroma. RESULTS: There was no statistically significant difference in MMP-7 and -26 expression between the epithelium of ameloblastomas (P = .50) and AOTs (P = .90). Stromal staining for MMP-7 was evident in all cases. For MMP-26, stromal staining was observed in 65% of ameloblastomas and 50% of AOTs, and this difference was not statistically significant (P = .69). CONCLUSION: The marked expression of these matrilysins suggests their role in the process of tissue remodeling and growth in the studied tumors, but it does not relate to the their distinct patterns of aggressiveness

Expression of extracellular matrix proteins in ameloblastomas and adenomatoid odontogenic tumors

This study evaluated the expression of fibronectin, tenascin and type I collagen in ameloblastomas and adenomatoid odontogenic tumors (AOTs) aiming to contribute with the comprehension of the differences in the biological behavior of these tumors. Immunohistochemical technique was performed in 20 cases of ameloblastoma (16 solid and 4 desmoplastic) and in 10 cases of AOT. All tumors presented moderate fibronectin expression in the stroma. Solid ameloblastomas showed intense expression of fibronectin at the epithelial-mesenchymal interface, whereas desmoplastic ameloblastomas revealed no immunoexpression of fibronectin at this site. Ameloblastomas presented stronger immunoreactivity to tenascin than AOTs, especially at the epithelial-mesenchymal interface. AOTs and desmoplastic ameloblastomas showed intense labeling for type I collagen. The patterns of expression of the proteins studied agree with the locally more invasive behavior of ameloblastomas in comparison to AOTs. Our results might suggest a less invasive behavior of desmoplastic ameloblastoma in comparison to solid ameloblastoma

Analysis of scientific production in oral pathology: a descriptive study

Objective: This research aimed to make a profile of the researches in an oral pathology post graduate program regarding to annual distribution, research subjects and financial support. Methods: The publications from the Annals Books from the Annual Session of the Brazilian Society of Research in Odontology (SBPqO) were analyzed, since 1984 until 2009. The sample was composed by 116 works, with the greater part (88) done after the doctoral program creation. Results: Seventeen (14.6%) works were made prior to creation of doctorate program, and the major part (n=99 / 85.4%) was done after that. The prevalent research subjects were: oral cancer (31.8%) and odontogenic cysts and tumors (18.2%). CNPq and CAPES were the most remarkable financial support agencies, with 30.8% and 24.8% each one, respectively. Conclusions: The program evaluated here exemplifies the scientific production of post graduation programs in oral pathology, showing its role in execution and publication of scientific works, also following the changes in research that occurred in Brazil in the last decades

Immunohistochemical expression of E-cadherin and beta-catenin in ameloblastomas and tooth germs

OBJECTIVE: The aim was to analyze the expression of E-cadherin and beta-catenin in ameloblastomas and tooth germs to determine their roles in cell differentiation processes and invasiveness compared with odontogenesis. STUDY DESIGN: Twenty-one ameloblastoma cases (16 solid and 5 unicystic tumors) and 5 tooth germs were submitted to the immunohistochemical detection of E-cadherin and beta-catenin. Immunoreactivity was evaluated using descriptive and semiquantitative analysis, investigating the location and intensity of staining. The Fisher exact test was performed, and P values of <.05 were considered to indicate statistical significance. RESULTS: There was no statistically significant difference in the expression of E-cadherin and beta-catenin between solid and unicystic ameloblastomas (P = .59; P = .63; respectively). The same was found when comparing solid and unicystic ameloblastomas with the tooth germs for both E-cadherin (P = .53; P = .44; respectively) and beta-catenin (P = .12; P = .16; respectively). Nuclear staining of beta-catenin was observed in only 4 cases (3 solid and 1 unicystic tumor). CONCLUSION: The results showed no differences in the expression of E-cadherin or beta-catenin between tooth germs and solid and unicystic ameloblastomas. The expression of these molecules seems mainly to be related to the process of cell differentiation

Stanniocalcin 2 contributes to aggressiveness and is a prognostic marker for oral squamous cell carcinoma

Stanniocalcin 2 (STC2), a glycoprotein that regulates calcium and phosphate homeostasis during mineral metabolism, appears to display multiple roles in tumorigenesis and cancer progression. This study aimed to access the prognostic value of STC2 in oral squamous cell carcinoma (OSCC) and its implications in oral tumorigenesis. STC2 expression was examined in 2 independent cohorts of OSCC tissues by immunohistochemistry. A loss-of-function strategy using shRNA targeting STC2 was employed to investigate STC2 in vitro effects on proliferation, apoptosis, migration, invasion, epithelial-mesenchymal transition (EMT) and possible activation of signaling pathways. Moreover, STC2 effects were assessed in vivo in a xenograft mouse cancer model. High expression of STC2 was significantly associated with poor disease-specific survival (HR: 2.67, 95% CI: 1.37-5.21, p = 0.001) and high rate of recurrence with a hazard ratio of 2.80 (95% CI: 1.07-5.71, p = 0.03). In vitro downregulation of STC2 expression in OSCC cells attenuated proliferation, migration and invasiveness while increased apoptotic rates. In addition, the STC2 downregulation controlled EMT phenotype of OSCC cells, with regulation on E-cadherin, vimentin, Snaill, Twist and Zeb2. The reactivation of STC2 was observed in the STC2 knockdown cells in the in vivo xenograft model, and no influence on tumor growth was observed. Modulation of STC2 expression levels did not alter consistently the phosphorylation status of CREB, ERK, JNK, p38, p70 S6K, STAT3, STAT5A/B and AKT. Our findings suggest that STC2 overexpression is an independent marker of OSCC outcome and may contribute to tumor progression via regulation of proliferation, survival and invasiveness of OSCC cells.Peer reviewe

Serotonin and cholecystokinin synergistically stimulate rat vagal primary afferent neurones

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65669/1/jphysiol.2004.064816.pd

Metal-macrofauna interactions determine microbial community structure and function in copper contaminated sediments

Peer reviewedPublisher PD