Insulin-like peptide genes in honey bee fat body respond differently to manipulation of social behavioral physiology

Nutrient sensitive insulin-like peptides (ILPs) have profound effects on invertebrate metabolism, nutrient storage, fertility and aging. Many insects transcribe ILPs in specialized neurosecretory cells at changing levels correlated with life history. However, the major site of insect metabolism and nutrient storage is not the brain, but rather the fat body, where functions of ILP expression are rarely studied and poorly understood. Fat body is analogous to mammalian liver and adipose tissue, with nutrient stores that often correlate with behavior. We used the honey bee (Apis mellifera), an insect with complex behavior, to test whether ILP genes in fat body respond to experimentally induced changes of behavioral physiology. Honey bee fat body influences endocrine state and behavior by secreting the yolk protein precursor vitellogenin (Vg), which suppresses lipophilic juvenile hormone and social foraging behavior. In a two-factorial experiment, we used RNA interference (RNAi)-mediated vg gene knockdown and amino acid nutrient enrichment of hemolymph (blood) to perturb this regulatory module. We document factor-specific changes in fat body ilp1 and ilp2 mRNA, the bee`s ILP-encoding genes, and confirm that our protocol affects social behavior. We show that ilp1 and ilp2 are regulated independently and differently and diverge in their specific expression-localization between fat body oenocyte and trophocyte cells. Insect ilp functions may be better understood by broadening research to account for expression in fat body and not only brain.

DETERMINATION OF ENERGY VALUE OF HAMBURGERS AND MEATBALLS BY DIRECT CALORIMETRY AND FOOD ANALYSIS COMPOSITION. COMPARISON WITH NUTRITION INFORMATION DISPLAYED ON PACKAGES

The nutritional composition found in the laboratory and those present on labels of manufactured foods can differ significantly. The purpose of this study was to determine the nutritional composition of hamburgers and meatballs and compare them with your labels. The food analysis was performed following the Analytical Standards Institute`s Adolfo Lutz and energy content was determined by bomb calorimetry. Regarding the energy value, all the samples had values less than informed on the label. The content of lipids of hamburgers and meatballs ( except the beef) were lower than those reported on the label. The values of protein for the meatballs and chicken hamburger had lower values than those labels. Thus, the labels may overestimate as underestimate some nutritional values, leading to population erroneous information.

Binding of Dengue Virus Partitcles and Dengue Proteins onto Solid Surfaces

The interaction between dengue virus particles (DENV), sedimentation hemagglutinin particles (SHA), dengue virus envelope protein (Eprot), and solid surfaces was investigated by means of ellipsometry and atomic force microscopy (AFM). The surfaces chosen are bare Si/SiO(2) wafers and Si/SiO(2) wafers covered with concanavalin A (ConA), jacalin (Jac), polystyrene (PS), or poly(styrene sulfonate) (PSS) films. Adsorption experiments at pH 7.2 and pH 3 onto all surfaces revealed that (i) adsorption of DENV particles took place only onto ConA under pH 7.2, because of specific recognition between glycans on DENV surface and ConA binding site; (ii) DENV particles did not attach to any of the surfaces at pH 3, suggesting the presence of positive charges on DENV surface at this pH, which repel the positively charged lectin surfaces; (iii) SHA particles are positively charged at pH 7.2 and pH 3 because they adhered to negatively charged surfaces at pH 7.2 and repelled positively charged layers at pH 3; and (iv) SHA particles carry polar groups on the surface because they attached to silanol surfaces at pH 3 and avoided hydrophobic PS films at pH 3 and pH 7.2. The adsorption behavior of Eprot at pH 7.2 revealed affinity for ConA > Jac > PSS > PS approximate to bare Si/SiO(2) layers. These findings indicate that selectivity of the Eprot adsorption is higher when it is part of virus structure than when it is free in solution. The correlation between surface energy values determined by means of contact angle measurements and DENV, SHA, or Eprot adsorption behavior was used to understand the intermolecular forces at the interfaces. A direct correlation was not found because the contributions from surface energy were probably surpassed by specific contributions.

Pharmacological Manipulation of Immune-Induced Food Aversion in Rats

Background: Mice allergic to ovalbumin (OVA) avoid drinking a solution containing this antigen. This was interpreted as related to IgE-dependent mast cell degranulation and sensory C fiber activation. Methods: We employed pharmacological manipulation to further investigate the mediators involved in immune-induced food aversion. Results: While nonimmunized rats preferred a sweetened OVA solution, immunized rats avoided it. We also employed a paradigm in which rats are conditioned to drink water for two 10-min sessions a day. Tolerant rats presented lower IgE titers, and this manipulation abrogated food aversion. Dexamethasone (1.0 mg/kg) prevented the aversion of OVA-immunized rats to the antigen-containing solution. Combined blockade of H(1) and 5-hydroxytryptamine (5-HT)(2) receptors by promethazine (3.0 mg/kg) plus methysergide (5.0 mg/kg) was unable to alter food aversion. Blockade of 5-HT(3) receptors by ondansetron (1.0 mg/kg) caused a twofold increase in the ingestion of the sweetened OVA solution by immunized rats, suggesting the involvement of 5-HT(3) receptors in food aversion. Finally, we showed that dexamethasone or promethazine plus methysergide, but not ondansetron, effectively prevented the IgE-dependent mast-cell-degranulation-induced increase in vascular permeability in rats. Conclusion: We suggest that regardless of whether or not they cause edema, IgE-mediated mast cell degranulation and consequent 5-HT(3) signaling are involved in the process that triggers avoidance to the source of the allergen in allergic rats. Copyright (C) 2008 S. Karger AG, Basel

Accuracy of working length determination using 3 electronic apex locators and direct digital radiography

Objectives. The objectives of this study were to assess the accuracy of working length determination using 3 electronic apex locators and direct digital radiography and to compare the results with those obtained using the visual method (control measurement). Study design. Twenty extracted human maxillary premolars were selected: 17 two-rooted and 3 single-rooted (total of 37 canals). Working length was measured using electronic apex locators Elements Diagnostic, Root ZX, and Just II. Subsequently, teeth were positioned in the alveolar bone of a dry skull and submitted to direct digital radiography. A variation of +/- 1 mm was considered as acceptable. Results were analyzed using the Wilcoxon and the chi(2) tests. Results. Results presented an accuracy of 94.6% for Elements Diagnostic, 91.9% for Root ZX, 73.0% for Just II, and 64.9% for direct digital radiography when considering the margin of +/- 1 mm in relation to the control measurement. Comparisons with the actual control measurements resulted in accuracy results of 13.51%, 13.51%, 10.10%, and 2.70%, respectively. Conclusions. Root ZX and Elements Diagnostic are more accurate in determining working length when compared with Just II and Schick direct digital radiography. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011;111:e44-e49)

Micromorphology of Resin-Dentin Interfaces Using One-Bottle Etch&Rinse and Self-Etching Adhesive Systems on Laser-Treated Dentin Surfaces: A Confocal Laser Scanning Microscope Analysis

Background and Objectives: This study evaluated the hybrid layer (HL) morphology created by three adhesive systems (AS) on dentin surfaces treated with Er:YAG laser using two irradiation parameters. Study Design: Occlusal flat dentin surfaces of 36 human third molars were assigned into nine groups (n = 4) according to the following ASs: one bottle etch&rinse Single Bond Plus (3M ESPE), two-step Clearfil Protect Bond (Kuraray), and all-in-one S3 Bond (Kuraray) self-etching, which were labeled with rhodamine B or fluorescein isothiocyanate dextran and were applied to dentin surfaces that were irradiated with Er:YAG laser at either 120 (38.7 J/cm(2)) or 200 mJ/pulse (64.5 J/cm(2)), or were applied to untreated dentin surfaces (control group). The ASs were light-activated following MI and the bonded surfaces were restored with resin composite Z250 (3M ESPE). After 24 hours of storage in vegetable oil, the restored teeth were vertically, serially sectioned into 1-mm thick slabs, which had the adhesive interfaces analyzed with confocal laser microscope (CLSM-LSM 510 Meta). CLSM images were recorded in the fluorescent mode from three different regions along each bonded interface. Results: Non-uniform HL was created on laser-irradiated dentin surfaces regardless of laser irradiation protocol for all AS, while regular and uniform HL was observed in the control groups. ""Stretch mark""-like red lines were found within the HL as a result of resin infiltration into dentin microfissures, which were predominantly observed in 200 mJ/pulse groups regardless of AS. Poor resin infiltration into peritubular dentin was observed in most regions of adhesive interfaces created by all ASs on laser-irradiated dentin, resulting in thin resin tags with neither funnel-shaped morphology nor lateral resin projections. Conclusion: Laser irradiation of dentin surfaces at 120 or 200 mJ/pulse resulted in morphological changes in HL and resin tags for all ASs evaluated in the study. Lasers Surg. Med. 42:662-670, 2010. (C) 2010 Wiley-Liss, Inc.

Morphological assessment of dentine and cementum following apicectomy with Zekrya burs and Er:YAG laser associated with direct and indirect Nd:YAG laser irradiation

Objectives. This study aimed to assess the apical surface morphology of maxillary central incisors resected 3.0 mm from the tooth apex using Zekrya burs or Er:YAG laser, with or without subsequent direct Nd:YAG laser irradiation (apical and buccal surfaces) and indirect irradiation (palatal surface). Study design. Forty maxillary central incisors were instrumented and obturated. The roots were divided into 4 groups according to the root resection method (Zekrya bur or Er: YAG laser -1.8 W, 450 mJ, 4 Hz, 113 J/cm(2)) and further surface treatment (none or Nd: YAG laser -2.0 W, 100 mJ, 20 Hz, 124 J/cm(2)). The teeth were prepared for SEM analysis. Scores ranging from 1 to 4 were attributed to cut quality and morphological changes. The data were analyzed by the Kruskal-Wallis test and by Dunn`s test. Results. SEM images showed irregular surfaces on the apical portions resected with Zekrya burs, with smear layer and grooves in the resected dentine and slight gutta-percha displacement and plasticization. On the other hand, apicectomies carried out with Er: YAG laser showed morphological changes compatible with ablated dentine, with rough surfaces and craters. In spite of the presence of plasticized gutta-percha, with the presence of bubbles, an irregular adaptation of the filling material to the root walls was also observed. Direct Nd: YAG laser irradiation of the apical and buccal surfaces of the resected roots resulted in areas of resolidification and fusion in the dentine and cementum, with a vitrified aspect; indirect Nd: YAG laser irradiation of the palatal surfaces yielded a lower number of changes in the cementum, with irregular resolidification areas. Conclusions. There were no differences in terms of cut quality between the use of burs and Er: YAG laser or between the 2 surfaces (apical and buccal) treated with Nd: YAG laser with direct irradiation. However, morphological changes were significantly less frequent on surfaces submitted to indirect irradiation (palatal) when compared with those directly irradiated. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010; 109: e77-e82)

Accuracy of direct digital radiography for detecting occlusal caries in primary teeth compared with conventional radiography and visual inspection: an in vitro study

Objectives: The diagnosis of caries lesions is still a matter of concern in dentistry. The diagnosis of dental caries by digital radiography has a number of advantages over conventional radiography; however, this method has not been explored fully in the field of paediatric dentistry. This in vitro research evaluated the accuracy of direct digital radiography compared with visual inspection and conventional radiography in the diagnosis of occlusal caries lesions in primary molars. Methods: 50 molars were selected and evaluated under standardized conditions by 2 previously calibrated examiners according to 3 diagnostic methods (visual inspection, conventional radiography and direct digital radiography). Direct digital radiographs were obtained with the Dixi3 system (Planmeca, Helsinki, Finland) and the conventional radiographs with InSight film (Kodak Eastman Co., Rochester, NY). The images were scored and a reference standard was obtained histologically. The interexaminer reliability was calculated using Cohen`s kappa test and the specificity, sensitivity and accuracy of the methods were calculated. Results: Examiner reliability was good. For lesions limited to the enamel, visual inspection showed significantly higher sensitivity and accuracy than both radiographic methods, but no significant difference was found in specificity. For teeth with dentinal caries, no significant differences were found for any parameter when comparing visual and radiographic evaluation. Conclusions: Although less accurate than the visual method for detecting caries lesions confined to the enamel, the direct digital radiographic method is as effective as conventional radiographic examination and visual inspection of primary teeth with occlusal caries when the dentine is involved. Dentomaxillofacial Radiology (2010) 39, 362-367. doi: 10.1259/dmfr/22865872

Direct comparison of the bond strength results of the different test methods: A critical literature review

Objective. The goal of this paper is to undertake a literature search collecting all dentin bond strength data obtained for six adhesives with four tests ( shear, microshear, tensile and microtensile) and to critically analyze the results with respect to average bond strength, coefficient of variation, mode of failure and product ranking. Method. A PubMed search was carried out for the years between 1998 and 2009 identifying publications on bond strength measurements of resin composite to dentin using four tests: shear, tensile, microshear and microtensile. The six adhesive resins were selected covering three step systems ( OptiBond FL, Scotch Bond Multi-Purpose Plus), two-step (Prime & Bond NT, Single Bond, Clear. l SE Bond) and one step (Adper Prompt L Pop). Results. Pooling results from 147 references showed an ongoing high scatter in the bond strength data regardless which adhesive and which bond test was used. Coefficients of variation remained high (20-50%) even with the microbond test. The reported modes of failure for all tests still included high number of cohesive failures. The ranking seemed to be dependant on the test used. Significance. The scatter in dentin bond strength data remains regardless which test is used confirming Finite Element Analysis predicting non-uniform stress distributions due to a number of geometrical, loading, material properties and specimens preparation variables. This reopens the question whether, an interfacial fracture mechanics approach to analyze the dentin - adhesive bond is not more appropriate for obtaining better agreement among dentin bond related papers. (C) 2009 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

A direct composite resin stratification technique for restoration of the smile

Composite resins can be used to improve the esthetics of the smile at a low cost and with relatively high clinical performance, The aim of this article was to describe an approach to restore and enhance the esthetic appearance of the anterior dentition through vital tooth whitening and the direct layering of composite resin during predictable esthetic procedures, (Quintessence lot 2011;42205-211)

Direct and transdentinal antibacterial activity of chlorhexidine

Purpose: To evaluate the antibacterial effect of different chlorhexidine (CHX) concentrations against Streptococcus mutans using the agar-diffusion method with and without human dentin discs placed between the bacteria and the test substances. Methods: For the direct application (agar-well technique), a base layer containing 15 mL of BHI agar and 300 mu L. of S. mutans inoculum (10(9) cfu/mL) was prepared in Petri dishes. Six wells per dish were made at equidistant points and immediately filled with CHX gels (0.12%, 0.2%, 1% and 2%), 35% phosphoric acid and pure natrosol (n=6 wells/substance). Paper discs soaked in sterile distilled water served as control group (n=6). For the indirect application (transdentinal diffusion), 0.2 mm- and 0.5 mm-thick human dentin discs (36 discs/thickness) had the hydraulic conductance determined, which allowed the homogeneous allocation of them to the experimental and control groups. The discs were placed at equidistant points on the Petri dishes containing BHI with the S. mutans inoculum (six discs per dish; one per substance) with the pulpal side in contact with the bacteria. In the discs treated with CHX gels, dentin surface was etched with H(3)PO(4) and rinsed with distilled water before CHX gel application for 1 minute. After both direct and indirect application, the dishes were incubated for 24 hours and the bacterial growth inhibition zones formed around the wells and dentin discs were measured. Data were analyzed statistically by the non-parametric Kruskal-Wallis and Mann-Whitney tests at 5% significance level. Results: In the direct test, all CHX concentrations presented a dose-dependent antibacterial activity against S. mutans. In the indirect test, there were statistically significant differences (P< 0.05) among all groups and the largest microbial growth inhibition zones were observed when 2% CHX was applied on 0.2 mm-thick discs (P< 0.05). It was concluded that all evaluated CHX gels exhibited both direct and transdentinal antibacterial activity against S. mutans. This effect of CHX was strongly influenced by the CHX concentration as well as the dentin barrier thickness. (Am J Dent 2010;23:255-259).

Direct pulp capping with a self-etching adhesive system: Histopathologic evaluation in dogs` teeth

Objective. This study evaluated histopathologically the response of pulp and periradicular tissues after pulp capping with an all-in-one self-etching adhesive system in dogs` teeth. Study design. Forty teeth of 4 dogs were assigned to 3 groups according to the pulp capping material: G1 (n = 20): self-etching adhesive system; G2 (n = 10): Ca(OH)(2); G3 (n = 10): zinc oxide-eugenol. The animals were killed 7 and 70 days after pulp capping. The pieces containing the pulp-capped teeth were removed and processed for histologic analysis. Results. At 7 days, no dentin bridge formation was observed; G1 and G3 exhibited inflammatory pulpal alterations, whereas G2 presented only mild inflammatory infiltrate in the pulp tissue adjacent to the capping material, the remainder being intact. At 70 days, no specimen in G1 or G3 presented dentin bridge formation. The remaining pulp tissue exhibited severe inflammatory alterations and areas of necrosis. In G2, all specimens showed dentin bridge formation and absence of inflammation and mineralized tissue resorption. No bacteria were identified using Brown and Brenn staining techniques in all 3 groups at any observation period. Conclusion. According to the conditions of this study, direct pulp capping with the self-etching adhesive system did not allow pulp tissue repair and failed histopathologically in 100% of the cases. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009; 108: e34-e40)

Influence of Post and Resin Cement on Stress Distribution of Maxillary Central Incisors Restored with Direct Resin Composite

The current study evaluated the influence of two endodontic post systems and the elastic modulus and film thickness of resin cement on stress distribution in a maxillary central incisor (MCI) restored with direct resin composite using finite element analysis (FEA). A three-dimensional model of an MCI with a coronary fracture and supporting structures was performed. A static chewing pressure of 2.16 N/mm(2) was applied to two areas on the palatal surface of the composite restoration. Zirconia ceramic (ZC) and glass fiber (GF) posts were considered. The stress distribution was analyzed in the post, dentin and cement layer when ZC and GF posts were fixed to the root canals using resin cements of different elastic moduli (7.0 and 18.6 GPa) and different layer thicknesses (70 and 200 mu m). The different post materials presented a significant influence on stress distribution with lesser stress concentration when using the GF post. The higher elastic modulus cement created higher stress levels within itself. The cement thicknesses did not present significant changes.

Single embryo and oocyte lipid fingerprinting by mass spectrometry

Methods used for lipid analysis in embryos and oocytes usually involve selective lipid extraction from a pool of many samples followed by chemical manipulation, separation and characterization of individual components by chromatographic techniques. Herein we report direct analysis by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) of single and intact embryos or oocytes from various species. Biological samples were simply moisturized with the matrix solution and characteristic lipid ( represented by phosphatidylcholines, sphingomyelins and triacylglycerols) profiles were obtained via MALDI-MS. As representative examples, human, bovine, sheep and fish oocytes, as well as bovine and insect embryos were analyzed. MALDI-MS is shown to be capable of providing characteristic lipid profiles of gametes and embryos and also to respond to modifications due to developmental stages and in vitro culture conditions of bovine embryos. Investigation in developmental biology of the biological roles of structural and reserve lipids in embryos and oocytes should therefore benefit from these rapid MALDI-MS profiles from single and intact species.-Ferreira, C. R., S. A. Saraiva, R. R. Catharino, J. S. Garcia, F. C. Gozzo, G. B. Sanvido, L. F. A. Santos, E. G. Lo Turco, J. H. F. Pontes, A. C. Basso, R. P. Bertolla, R. Sartori, M. M. Guardieiro, F. Perecin, F. V. Meirelles, J. R. Sangalli, and M. N. Eberlin. Single embryo and oocyte lipid fingerprinting by mass spectrometry. J. Lipid Res. 2010. 51: 1218-1227.

A case study of the direct radiative effect of biomass burning aerosols on precipitation in the Eastern Amazon

Numerical experiments with the Brazilian additions to the Regional Atmospheric Modeling System were performed with two nested grids (50 and 10 km horizontal resolution, respectively) with and without the effect of biomass burning for 8 different situations for 96 h integrations. Only the direct radiative effect of aerosols is considered. The results were analyzed in large areas encompassing the BR163 road (one of the main areas of deforestation in the Amazon). mainly where most of the burning takes place. The precipitation change due to the direct radiative impact of biomass burning is generally negative (i.e., there is a decrease of precipitation). However, there are a few cases with a positive impact. Two opposite forcing mechanisms were explored: (a) the thermodynamic forcing that is generally negative in the sense that the aerosol tends to stabilize the lower atmosphere and (b) the dynamic impact associated with the low level horizontal pressure gradients produced by the aerosol plumes. In order to understand the non-linear relationship between the two effects, experiments were performed with 4-fold emissions. In these cases, the dynamic effect overcomes the stabilization produced by the radiative forcing and precipitation increase is observed in comparison with the control experiment. This study suggests that. in general, the biomass burning radiative forcing decreases the precipitation. However, very large concentrations of aerosols may lead to an increase of precipitation due to the dynamical forcing associated with the horizontal pressure gradients. (C) 2009 Elsevier B.V. All rights reserved.