Testing a dynamic field account of interactions between spatial attention and spatial working memory

Studies examining the relationship between spatial attention and spatial working memory (SWM) have shown that discrimination responses are faster for targets appearing at locations that are being maintained in SWM, and that location memory is impaired when attention is withdrawn during the delay. These observations support the proposal that sustained attention is required for successful retention in SWM: if attention is withdrawn, memory representations are likely to fail, increasing errors. In the present study, this proposal is reexamined in light of a neural process model of SWM. On the basis of the model’s functioning, we propose an alternative explanation for the observed decline in SWM performance when a secondary task is performed during retention: SWM representations drift systematically toward the location of targets appearing during the delay. To test this explanation, participants completed a color-discrimination task during the delay interval of a spatial recall task. In the critical shifting attention condition, the color stimulus could appear either toward or away from the memorized location relative to a midline reference axis. We hypothesized that if shifting attention during the delay leads to the failure of SWM representations, there should be an increase in the variance of recall errors but no change in directional error, regardless of the direction of the shift. Conversely, if shifting attention induces drift of SWM representations—as predicted by the model—there should be systematic changes in the pattern of spatial recall errors depending on the direction of the shift. Results were consistent with the latter possibility—recall errors were biased toward the location of discrimination targets appearing during the delay

Interactions of Adiponectin and Lipopolysaccharide from Porphyromonas gingivalis on Human Oral Epithelial Cells

BACKGROUND: Periodontitis is an inflammatory disease caused by pathogenic microorganisms, such as Porphyromonas gingivalis, and characterized by the destruction of the periodontium. Obese individuals have an increased risk for periodontitis and show decreased serum levels of adiponectin. This in-vitro study was established to examine whether adiponectin modulates critical effects of lipopolysaccharide (LPS) from P. gingivalis on oral epithelial cells (OECs). METHODOLOGY/PRINCIPAL FINDINGS: The presence of adiponectin and its receptors in human gingival tissue samples and OECs was analyzed by immunohistochemistry and PCR. Furthermore, OECs were treated with LPS and/or adiponectin for up to 72 h, and the gene expression and protein synthesis of pro- and anti-inflammatory mediators, matrix metalloproteinases (MMPs) and growth factors were analyzed by real-time PCR and ELISA. Additionally, cell proliferation, differentiation and in-vitro wound healing were studied. The nuclear translocation of NFκB was investigated by immunofluorescence. Gingival tissue sections showed a strong synthesis of adiponectin and its receptors in the epithelial layer. In cell cultures, LPS induced a significant up-regulation of interleukin (IL) 1β, IL6, IL8, MMP1 and MMP3. Adiponectin abrogated significantly the stimulatory effects of LPS on these molecules. Similarly, adiponectin inhibited significantly the LPS-induced decrease in cell viability and increase in cell proliferation and differentiation. Adiponectin led to a time-dependent induction of the anti-inflammatory mediators IL10 and heme oxygenase 1, and blocked the LPS-stimulated NFκB nuclear translocation. CONCLUSIONS/SIGNIFICANCE: Adiponectin may counteract critical actions of P. gingivalis on oral epithelial cells. Low levels of adiponectin, as observed in obese individuals, may increase the risk for periodontal inflammation and destruction

Status of Endodontic Treatment and the Correlations to the Quality of Root Canal Filling and Coronal Restoration

Introduction: This cross-sectional study evaluated the prevalence and quality of root canal treatment in 1,977 digital radiological files. Materials and methods: Data were statistically analyzed using descriptive analysis, and the chi-square test was performed with a 5% significance level. Results: The mean age of the study population was 34.9 years. The endodontic treatment frequency was 6.14%, significantly higher in premolars. Adequate endodontic treatment was observed in 39.7% of analyzed cases. Molars were significantly more frequent with regard to inadequate filling quality. In 47.6% of cases, the filling's apical limit was classified as adequate, and there was a higher incidence of molars that were inadequate. Restorations were classified as adequate in 79.0% of cases, and molars were responsible for the highest frequency of inadequate restorations. The frequency of teeth with endodontic treatment that showed no periapical changes was 47.7%. There was no significant difference in the presence of periapical change according to gender. An increased presence of periapical change was observed with increasing age. The periapical lesions were observed in 45% of cases and related to inadequate filling quality. The apical limit was considered inadequate and related to periapical changes in 42% of cases. Periapical changes were present in 52% of cases, regardless of the quality of the filling and apical limit. Such changes were present in 42% of cases with adequate coronal restoration. Conclusion: It can be concluded that apical periodontitis (AP) is associated with the quality of endodontic treatment. The coronal restoration affects significantly the success rate of endodontic treatment. Clinical significance: The quality of the root filling and coronal restoration is closely related to periapical health.Department of Post-Graduate Program in Integrated Dental Science Dental School University of CuiabáDepartment of Post-Graduate Program in Dentistry CEUMA UniversityDepartment of Restorative Dentistry School of Dentistry Universidade Estadual PaulistaDepartment of Restorative Dentistry School of Dentistry Universidade Estadual Paulist