Micro-shear bond strength of Er:YAG-laser-treated dentin

This study tested if dentin adhesion is affected by Er:YAG laser. Ninety dentin disks were divided in groups (n = 10): G1, control; G2, Er:YAG laser 150 mJ, 90 degrees contact, 38.8 J/cm(2); G3, Er:YAG laser 70 mJ, 90 degrees contact, 18.1 J/cm(2); G4, Er:YAG laser 150 mJ, 90 degrees non-contact, 1.44 J/cm(2); G5, Er:YAG laser 70 mJ, 90 degrees non-contact, 0.67 J/cm(2); G6, Er:YAG laser 150 mJ, 45 degrees contact, 37.5 J/cm(2); G7, Er:YAG laser 70 mJ, 45 degrees contact, 17.5 J/cm(2); G8, Er:YAG laser 150 mJ, 45 degrees non-contact, 1.55 J/cm(2); and G9, Er:YAG laser 70 mJ, 45 degrees non-contact, 0.72 J/cm(2). Bonding procedures were carried out and the micro-shear-bond strength (MSBS) test was performed. The adhesive surfaces were analyzed under SEM. Two-way ANOVA and multiple comparison tests revealed that MSBS was significantly influenced by the laser irradiation (p < 0.05). Mean values (MPa) of the MSBS test were: G1 (44.97 +/- 6.36), G2 (23.83 +/- 2.46), G3 (30.26 +/- 2.57), G4 (35.29 +/- 3.74), G5 (41.90 +/- 4.95), G6 (27.48 +/- 2.11), G7 (34.61 +/- 2.91), G8 (37.16 +/- 1.96), and G9 (41.74 +/- 1.60). It was concluded that the Er:YAG laser can constitute an alternative tool for dentin treatment before bonding procedures.     

Peroxynitrite mediates the failure of neutrophil migration in severe polymicrobial sepsis in mice

BACKGROUND AND PURPOSE: Sepsis is a systemic inflammatory response resulting from the inability of the host to restrict local infection. The failure of neutrophil migration to the infection site is one of the mechanisms involved in this process. Recently, it was demonstrated that this event is mediated by nitric oxide (NO). The present study addresses the possibility that peroxynitrite (ONOO(-)), a NO-derived powerful oxidizing and nitrating compound, could also be involved in neutrophil migration failure. EXPERIMENTAL APPROACH: Male C57Bl/6 mice were subjected to moderate (MSI) or severe (SSI) septic injury, both induced by cecal ligation and puncture (CLP). The leukocyte rolling and adhesion in the mesentery was evaluated by intravital microscopy. Cytokines (TNF-alpha and MIP-1alpha) were measured by ELISA and 3-nitrotyrosine (3-NT) by immunofluorescence. KEY RESULTS: Compared with saline pretreatment of SSI mice, pre-treatment with uric acid, a ONOO(-) scavenger, partially restored the failure of neutrophil rolling, adhesion and migration to the site of infection. These mice also presented low circulating bacterial counts and diminished systemic inflammatory response. Pretreatment with uric acid reduced 3-NT labelling in leukocytes in mesenteric tissues and in neutrophils obtained from peritoneal exudates. Finally, uric acid pretreatment enhanced significantly the survival rate in the SSI mice. Similarly, treatment with FeTPPs, a more specific ONOO(-) scavenger, re-established neutrophil migration and increased mice survival rate. CONCLUSIONS AND IMPLICATIONS: These results indicate that ONOO(-) contributed to the reduction of neutrophil/endothelium interaction and the consequent failure of neutrophil migration into infection foci and hence susceptibility to severe sepsis.     

Gastroprotective activity of the hydroalcoholic extract obtained from Polygala paniculata L. in rats

The possible gastroprotective effects of the hydroalcoholic extract of Polygala paniculata in rats have been evaluated. We have investigated the effects of this hydroalcoholic extract on acute lesions induced by ethanol (70%, p.o.) and indomethacin (20 mg kg(-1), s.c.). Its influence on mucus secretion was investigated, measured as the amount of Alcian blue dye estimated by colorimetry, and antisecretory effects were assessed in the pylorus ligature model. The treatment of rats with a crude hydroalcoholic extract of P. paniculata (HEPP; 30, 100, 300 mg kg(-1), p.o., or 3, 10 and 30 mg kg(-1), i.p.) decreased the ulcer index, and maintained the gastric mucus production in acute gastric lesions caused by ethanol 70%. In addition, the extract partially protected the mucosa against indomethacin-induced lesions. The extract did not change the volume and acidity of gastric secretion in the pylorus-ligated rat. An additional antioxidant activity of the extract and its isolated flavonoid compound rutin, in the DPPH free radical scavenging assay, was observed. In conclusion, HEPP exhibited marked gastroprotection; these effects may have involved prostaglandins and be related to cytoprotective factors, such as antioxidant activity and maintenance of mucus production.     

Evaluation of Rana snk esculenta blood cell response to chemical stressors in the environment during the larval and adult phases

The assessment of the biological effects on aquatic vertebrate species is frequently employed to monitor water pollution, as it provides significant information on bioavailability and actual concentration levels. In anamniote vertebrates (fish and amphibians), significant correlations have been observed between exposure to contaminants - both natural and experimental - and blood modification. We investigated the changes in some circulating blood cell parameters of green frog (Rana snk esculenta) tadpoles and adults collected at two sample rice fields, one heavily polluted and the other relatively unpolluted. The frequency of eosinophilic leucocytes, mitotic, anucleated and micronucleated erythrocytes was evaluated also regarding the haemopoietic/haemocatheretic and NOS expression of the liver. Haematological indicators in polluted samples were found to be significantly different from controls as regards both larval and adult exposure, and provided information on long-term background pollution of the habitats under investigation. The population of the polluted area showed evident effects of chronic exposure to contaminants, to a degree which could lead to sub-lethal alterations of their health status. The general nature of responses to this kind of stress emphasizes the role of amphibian peripheral blood as a sensitive indicator regarding contamination in aquatic environments.     

Adhesion of composite luting cement to Er:YAG-laser-treated dentin

Although some studies claim to the increase of composite resin adhesion to Er:YAG-laser-treated dentin, there are still no reports on the adhesion of composite resin cements to the irradiated surface. This in vitro study evaluated the tensile bond strength (TBS) of a composite resin cement to dentin treated with the Er:YAG laser. Sixty human dentin samples were divided into four groups (n = 15): G1 (Control)-no treatment; G2-Er:YAG laser 60 mJ, 2 Hz, with water cooling, non-contact (19 J/cm(2)); G3-Er:YAG laser 60 mJ, 10 Hz, 50/10 fiber, contact, without water cooling (40 J/cm(2)); G4-Er:YAG laser 60 mJ, 10 Hz, 50/10 fiber, contact, with water cooling (40 J/cm(2)). After the surface treatment, each sample was submitted to bonding procedures. The analysis of variance (ANOVA) and Tukey tests revealed no statistical significant difference on TBS values for groups G1 (13.73 +/- 3.05 MPa), G2 (12.60 +/- 2.09 MPa) and G4 (11.17 +/- 4.04 MPa). G4 was not statistically different from G3 (8.64 +/- 2.06 MPa). Er:YAG laser irradiation with different settings can constitute an alternative tool to the use of composite resin-luting cements.     

Medicinal plants of the caatinga (semi-arid) vegetation of NE Brazil: a quantitative approach

The caatinga (semi-arid vegetation) is a Brazilian biome with a significant but poorly studied biodiversity closely associated with a diverse cultural heritage. The present work focused on analyzing published information available concerning medicinal plants used by traditional communities. We sought to contribute to future phytochemical and pharmacological investigations by documenting the therapeutic uses of native caatinga plants within the aims of modern ethnopharmacological research. Twenty-one published works cited a total of 389 plant species used by indigenous and rural communities in northeastern Brazil for medicinal purposes. The relative importance index (RI) of each species in these inventories was calculated, and information concerning the plant's local status (spontaneous or cultivated), distribution, and habit was recorded. Of the 275 spontaneous (non-cultivated) species cited, 15.3% were endemic to the caatinga. A statistical relationship was verified between the relative importance of the species and their endemic status (p<0.05). Herbaceous plants were more numerous (169) than trees (90) or shrubs and sub-shrubs (130) at a statistically significant level (p<0.05). A survey of published information on the phytochemical and pharmacological status of the plants demonstrating the highest RI supported the veracity of their attributed folk uses.