Bond strength of fibre glass and carbon fibre posts to the root canal walls using different resin cements

The aim of the study was to evaluate the bond strength of fibre glass and carbon fibre posts in the root canal walls cemented with self-adhesive (RelyX-Unicem) and chemical (Cement-Post) resin cements. Forty maxillary canines were divided into four groups according to the cement and post used and submitted to the push-out test (0.5 mm min(-1)). The data were submitted to statistical analysis (2-way ANOVA, Bonferroni - P < 0.05) and fracture analysis by Scanning Electronic Microscopy. Fibre glass presented the best results when cemented with RelyX-Unicem and Cement-Post (P < 0.05). RelyX-Unicem presented the highest bond strength values for both posts (P < 0.05). Fracture analysis showed predominance of cohesive fracture of post for RelyX-Unicem and adhesive fracture between dentin/cement and mixed for Cement-Post. The bond strength values were significantly affected by the type of post and cement used and the highest values were found for fibre glass posts and RelyX-Unicem.

Bond Strength of Fiber Posts in Different Root Thirds Using Resin Cement

Purpose: The aim of the study was to assess the in vitro bond strength (BS) of glass fiber posts (GF) and carbon fiber posts (CF) in the cervical, middle, and apical thirds of root canals cemented with RelyX-Unicem (RX) and Cement-Post (CP). Materials and Methods: Forty maxillary canines were divided into 4 groups (n = 10) according to the cement and post used: group 1: GF and RX; group 2: CF and RX; group 3: GF and CP; group 4: CF and CP. The push-out test was applied in the cervical, middle and apical thirds of each specimen to assess bond strength of the cement/post complex to the root canal wall. The data obtained were submitted to ANOVA (Bonferroni test, p < 0.05), and fracture analysis was done with SEM. Results: The GF posts presented the best results when cemented with RX and with CF (p < 0.05). RX presented the highest BS values for both GF and CF (p < 0.05). For all the groups, BS was higher in the cervical third, followed by the middle and apical thirds. Fracture analysis showed a predominance of cohesive fracture of posts for RX, and a predominance of adhesive fracture between dentin/cement, and mixed failure mode for CP. Conclusion: GF posts cemented with RX presented the highest BS values in all root thirds.

Exposure to ambient levels of particles emitted by traffic worsens emphysema in mice

Objectives: We investigated effects of chronic exposure (2 months) to ambient levels of particulate matter (PM) on development of protease-induced emphysema and pulmonary remodeling in mice. Methods: Balb/c mice received nasal drop of either papain or normal saline and were kept in two exposure chambers situated in an area with high traffic density. One of them received ambient air and the other had filters for PM. Results: mean concentration of PM10 was 2.68 +/- 0.38 and 33.86 +/- 2.09 mu g/m(3), respectively, in the filtered and ambient air chambers (p<0.001). After 2 months of exposure, lungs from papain-treated mice kept in the chamber with ambient air presented greater values of mean linear intercept, an increase in density of collagen fibers in alveolar septa and in expression of 8-isoprostane (p = 0.002, p < 0.05 and p = 0.002, respectively, compared to papain-treated mice kept in the chamber with filtered air). We did not observe significant differences between these two groups in density of macrophages and in amount of cells expressing matrix metalloproteinase-12. There were no significant differences in saline-treated mice kept in the two chambers. Conclusions: We conclude that exposure to urban levels of PM worsens protease-induced emphysema and increases pulmonary remodeling. We suggest that an increase in oxidative stress induced by PM exposure influences this response. These pulmonary effects of PM were observed only in mice with emphysema. (C) 2009 Elsevier Inc. All rights reserved.

Photometric redshifts and k-corrections for the Sloan Digital Sky Survey Data Release 7

We present a catalogue of galaxy photometric redshifts and k-corrections for the Sloan Digital Sky Survey Data Release 7 (SDSS-DR7), available on the World Wide Web. The photometric redshifts were estimated with an artificial neural network using five ugriz bands, concentration indices and Petrosian radii in the g and r bands. We have explored our redshift estimates with different training sets, thus concluding that the best choice for improving redshift accuracy comprises the main galaxy sample (MGS), the luminous red galaxies and the galaxies of active galactic nuclei covering the redshift range 0 < z < 0.3. For the MGS, the photometric redshift estimates agree with the spectroscopic values within rms = 0.0227. The distribution of photometric redshifts derived in the range 0 < z(phot) < 0.6 agrees well with the model predictions. k-corrections were derived by calibration of the k-correct_v4.2 code results for the MGS with the reference-frame (z = 0.1) (g - r) colours. We adopt a linear dependence of k-corrections on redshift and (g - r) colours that provide suitable distributions of luminosity and colours for galaxies up to redshift z(phot) = 0.6 comparable to the results in the literature. Thus, our k-correction estimate procedure is a powerful, low computational time algorithm capable of reproducing suitable results that can be used for testing galaxy properties at intermediate redshifts using the large SDSS data base.

Melanopsin and Clock Genes: Regulation by Light and Endothelin in the Zebrafish ZEM-2S Cell Line

It is well known that clocks are present in brain regions other than the suprachiasmatic nucleus and in many peripheral tissues. In the teleost, Danio rerio, peripheral oscillators can be directly synchronized by light. Danio rerio ZEM-2S embryonic cells respond to light with differential growth: cells kept in constant light exhibited a strong inhibition of proliferation, whereas in cells kept in light:dark (LD) cycles (14L:10D and 10L:14D) or in constant darkness (DD), the doubling times were not statistically different. We demonstrated by RT-PCR followed by PCR that ZEM-2S cells express two melanopsins, Opn4x and Opn4m, and the six Cry genes. The presence of the protein OPN4x was demonstrated by immunocytochemistry. The pattern of temporal expression of the genes Opn4x, Per1, Cry1b, and Clock was studied in ZEM-2S cells kept for five days in 12L:12D or DD. In 12L:12D, the clock genes Per 1 and Cry1b exhibited robust circadian expression, while Opn4x and Clock expression seemed to vary in an ultradian pattern. Both Per1 and Cry1b genes had higher expression during the L phase; Clock gene had an increase in expression coincident with the D phase, and during the subjective night. In DD, the temporal variation of Per1 and Cry1b genes was greatly attenuated but not extinguished, and the higher expressions were shifted to the transition times between subjective day and night, demonstrating that Per and Cry1b were synchronized by the LD cycle. Clock and Opn4x kept the ultradian oscillation, but the rhythm was not statistically significant. As endothelins (ET) have been reported to be a potent stimulator of Per genes in rodents, we investigated the effect of endothelin on ZEM-2S cells, which express ETA receptors. Cells were kept in 12D:12L for five days, and then treated with 10-11 to 10-8M ET-1 for 24h. ET-1 exhibited a biphasic effect on Opn4x expression. At 10-11M, the hormone exerted a highly significant stimulation of Opn4x expression during the L phase and introduced a circadian oscillatory pattern. At 10-10M, a significant increase was seen at ZT21 and ZT0 (i.e., at the end of the D phase and beginning of the L phase), whereas 10-9 and 10-8M ET-1 inhibited the expression of Opn4x at most ZTs. Clock expression was unaffected by 10-8M ET-1; however, in the presence of lower concentrations, the expression was enhanced at some ZTs, strengthening the ultradian oscillation. ET-1 at 10-11 and 10-10M had no effect on Per1 circadian expression; however, 10-9 and 10-8M ET-1 reduced the amplitude of Per1 expression in the beginning of the L phase. ET-1 effects were less evident on Cry 1b. For both genes, the reduction in expression was not sufficient to abolish the circadian oscillatory pattern. Based on these results and data in the literature, a link between ET-1 stimulation of ETA receptors may be established by E4BP4 binding to the promoters and consequent inhibition of gene expression.

Novel OTOF mutations in Brazilian patients with auditory neuropathy

The OTOF gene encoding otoferlin is associated with auditory neuropathy (AN), a type of non-syndromic deafness. We investigated the contribution of OTOF mutations to AN and to non-syndromic recessive deafness in Brazil. A test for the Q829X mutation was carried out on a sample of 342 unrelated individuals with non-syndromic hearing loss, but none presented this mutation. We selected 48 cases suggestive of autosomal recessive inheritance, plus four familial and seven isolated cases of AN, for genotyping of five microsatellite markers linked to the OTOF gene. The haplotype analysis showed compatibility with linkage in 11 families (including the four families with AN). Samples of the 11 probands from these families and from seven isolated cases of AN were selected for an exon-by-exon screening for mutations in the OTOF gene. Ten different pathogenic variants were detected, among which six are novel. Among the 52 pedigrees with autosomal recessive inheritance (including four familial cases of AN), mutations were identified in 4 (7.7%). Among the 11 probands with AN, seven had at least one pathogenic mutation in the OTOF gene. Mutations in the OTOF gene are frequent causes of AN in Brazil and our results confirm that they are spread worldwide. Journal of Human Genetics (2009) 54, 382-385; doi: 10.1038/jhg.2009.45; published online 22 May 2009

Absence of Melatonin Induces Night-Time Hepatic Insulin Resistance and Increased Gluconeogenesis Due to Stimulation of Nocturnal Unfolded Protein Response

It is known that the circadian rhythm in hepatic phosphoenolpyruvate carboxykinase expression (a limiting catalytic step of gluconeogenesis) and hepatic glucose production is maintained by both daily oscillation in autonomic inputs to the liver and night feeding behavior. However, increased glycemia and reduced melatonin (Mel) levels have been recently shown to coexist in diabetic patients at the end of the night period. In parallel, pinealectomy (PINX) is known to cause glucose intolerance with increased basal glycemia exclusively at the end of the night. The mechanisms that underlie this metabolic feature are not completely understood. Here, we demonstrate that PINX rats show night-time hepatic insulin resistance characterized by reduced insulin-stimulated RAC-alpha serine/threonine-protein kinase phosphorylation and increased phosphoenolpyruvate carboxykinase expression. In addition, PINX rats display increased conversion of pyruvate into glucose at the end of the night. The regulatory mechanism suggests the participation of unfolded protein response (UPR), because PINX induces night-time increase in activating transcription factor 6 expression and prompts a circadian fashion of immunoglobulin heavy chain-binding protein, activating transcription factor 4, and CCAAT/enhancer-binding protein-homologous protein expression with Zenith values at the dark period. PINX also caused a night-time increase in Tribble 3 and regulatory-associated protein of mammalian target of rapamycin; both were reduced in liver of PINX rats treated with Mel. Treatment of PINX rats with 4-phenyl butyric acid, an inhibitor of UPR, restored night-time hepatic insulin sensitivity and abrogated gluconeogenesis in PINX rats. Altogether, the present data show that a circadian oscillation of UPR occurs in the liver due to the absence of Mel. The nocturnal UPR activation is related with night-time hepatic insulin resistance and increased gluconeogenesis in PINX rats. (Endocrinology 152: 1253-1263, 2011)

Immobilized Kidney 28-kDa Endostatin- Related (KES28kDa) Fragment Promotes Endothelial Cell Survival

Background/Objective: Renal ischemia-hypoxia is a leading cause of acute kidney injury (AKI). Ischemia causes extracellular matrix breakdown of the tubular basement membrane. Endostatin (ES) is the C-terminal fragment of collagen XVIII generated by proteolytic cleavage. Recent studies have demonstrated that ES expression is upregulated in ischemic kidneys. The present study aimed to characterize ES from ischemic kidneys. Methods: Ischemic renal failure was induced via 45 min of occlusion of the left renal artery and vein. After the ischemic period, blood was collected. Kidneys were harvested and used for immunohistochemical testing and protein extraction. Three-step purification was used. Soluble and immobilized purified ES were tested in cell viability and adhesion assays. Results: The soluble KES28kDa inhibited endothelial cell proliferation: 25 versus 12.5 mu g (p < 0.05); 12.5 versus 3.15 mu g (p < 0.05). Immobilization of KES28kDa supports endothelial cell survival over the control p = 0.021). Human umbilical vein endothelial cells plated on immobilized KES28kDa showed an increase in membrane ruffles and stress fibers. Conclusion: These data demonstrate the local synthesis of a 28-kDa ES-related fragment following AKI and suggest its role in endothelium survival. Copyright (C) 2010 S. Karger AG, Basel

The leptospiral antigen Lp49 is a two-domain protein with putative protein binding function

Pathogenic Leptospira is the etiological agent of leptospirosis, a life-threatening disease that affects populations worldwide. Currently available vaccines have limited effectiveness and therapeutic interventions are complicated by the difficulty in making an early diagnosis of leptospirosis. The genome of Leptospira interrogans was recently sequenced and comparative genomic analysis contributed to the identification of surface antigens, potential candidates for development of new vaccines and serodiagnosis. Lp49 is a membrane-associated protein recognized by antibodies present in sera from early and convalescent phases of leptospirosis patients. Its crystal structure was determined by single-wavelength anomalous diffraction using selenomethionine-labelled crystals and refined at 2.0 angstrom resolution. Lp49 is composed of two domains and belongs to the all-beta-proteins class. The N-terminal domain folds in an immunoglobulin-like beta-sandwich structure, whereas the C-terminal domain presents a seven-bladed beta-propeller fold. Structural analysis of Lp49 indicates putative protein-protein binding sites, suggesting a role in Leptospira-host interaction. This is the first crystal structure of a leptospiral antigen described to date. (C) 2008 Elsevier Inc. All rights reserved.

The combined effect of copper and low pH on antioxidant defenses and biochemical parameters in neotropical fish pacu, Piaractus mesopotamicus (Holmberg, 1887)

Copper sulfate is widely used in aquaculture. Exposure to this compound can be harmful to fish, resulting in oxidative metabolism alterations and gill tissue damage. Pacu, Piaractus mesopotamicus, (wt = 43.4 +/- A 3.35 g) were distributed in experimental tanks (n = 10; 180 l) and exposed for 48 h to control (without copper addition), 0.4Cu (0.4 mg l(-1)), 0CupH (without copper addition, pH = 5.0) and 0.4CupH (0.4 mg l(-1), pH = 5.0). In liver and red muscle, the superoxide dismutase (SOD) was responsive to the increases in the aquatic copper. The plasmatic intermediary metabolites and hematological variables in the fish of group 0.4Cu were similar to those of the control group. Conversely, the exposure to 0.4CupH caused an increase in the plasmatic lactate, number of red blood cells (RBC) and hemoglobin (Hb). Plasmatic copper concentration [Cu(p)] increased in group 0.4Cu and 0.4CupH, which is higher in group 0.4CupH, suggests an effect of water pH on the absorbed copper. Exposure to 0.4Cu and 0.4CupH resulted in a reduction in the Na(+)/K(+)-ATPase activity and an increase in metallothionein (MT) in the gills. Exposure to 0CupH caused a decrease in glucose and pyruvate concentrations and an increase in RBC, Hb, and the branchial Na(+)/K(+)-ATPase activity. These responses suggest that the fish triggered mechanisms to revert the blood acidosis, save energy and increase the oxygen uptake. MT was an effective biomarker, responding to copper in different pHs and dissolved oxygen. Combined-factors caused more significant disturbance in the biomarkers than single-factors.

AFM analysis of bleaching effects on dental enamel microtopography

The purpose of this in vitro study was to test a new methodology to evaluate the effects of 35% hydrogen peroxide agent on the microtopography of sound enamel using an atomic force microscope (AFM). The buccal sound surfaces of three extracted human lower incisors were used, without polishing the surfaces to maintain them with natural morphology. These unpolished surfaces were subjected to bleaching procedure with 35% hydrogen peroxide that consisted of 4 applications of the bleaching agent on enamel surfaces for 10 min each application. Surface images were obtained in a 15 mu m x 15 mu m area using an AFM. The roughness (Ra and RMS) and the power spectral density (PSD) were obtained before and after the bleaching treatment. As results we could inquire that the PSD analyses were very suitable to identifying the morphological changes on the surfaces, while the Ra and RMS parameters were insufficient to represent the morphological alterations promoted by bleaching procedure on enamel. The morphological wavelength in the range of visible light spectrum(380-750 nm) was analyzed, showing a considerable increase of the PSD with the bleaching treatment. (C) 2009 Elsevier B. V. All rights reserved.

Camptosemin, a tetrameric lectin of Camptosema ellipticum: structural and functional analysis

Lectins have been classified into a structurally diverse group of proteins that bind carbohydrates and glycoconjugates with high specificity. They are extremely useful molecules in the characterization of saccharides, as drug delivery mediators, and even as cellular surface makers. In this study, we present camptosemin, a new lectin from Camptosema ellipticum. It was characterized as an N-acetyl-d-galactosamine-binding homo-tetrameric lectin, with a molecular weight around 26 kDa/monomers. The monomers were stable over a wide range of pH values and exhibited pH-dependent oligomerization. Camptosemin promoted adhesion of breast cancer cells and hemagglutination, and both activities were inhibited by its binding of sugar. The stability and unfolding/folding behavior of this lectin was characterized using fluorescence and far-UV circular dichroism spectroscopies. The results indicate that chemical unfolding of camptosemin proceeds as a two-state monomer-tetramer process. In addition, small-angle X-ray scattering shows that camptosemin behaves as a soluble and stable homo-tetramer molecule in solution.

A new tick Kunitz type inhibitor, Amblyomin-X, induces tumor cell death by modulating genes related to the cell cycle and targeting the ubiquitin-proteasome system

The aim of this study was to evaluate the anti-tumor activity of Amblyomin-X, a serine protease Kunitz-type inhibitor. Amblyomin-X induced tumor mass regression and decreased number of metastatic events in a B16F10 murine melanoma model. Alterations on expression of several genes related to cell cycle were observed when two tumor cell lines were treated with Amblyomin-X. PSMB2, which encodes a proteasome subunit, was differentially expressed, in agreement to inhibition of proteasomal activity in both cell lines. In conclusion, our results indicate that Amblyomin-X selectively acts on tumor cells by inducing apoptotic cell death, possibly by targeting the ubiquitin-proteasome system. (C) 2010 Elsevier Ltd. All rights reserved.

Expression Profile of Rat Hippocampal Neurons Treated with the Neuroprotective Compound 2,4-Dinitrophenol: Up-Regulation of cAMP Signaling Genes

2,4-Dinitrophenol (DNP) is classically known as a mitochondrial uncoupler and, at high concentrations, is toxic to a variety of cells. However, it has recently been shown that, at subtoxic concentrations, DNP protects neurons against a variety of insults and promotes neuronal differentiation and neuritogenesis. The molecular and cellular mechanisms underlying the beneficial neuroactive properties of DNP are still largely unknown. We have now used DNA microarray analysis to investigate changes in gene expression in rat hippocampal neurons in culture treated with low micromolar concentrations of DNP. Under conditions that did not affect neuronal viability, high-energy phosphate levels or mitochondrial oxygen consumption, DNP induced up-regulation of 275 genes and down-regulation of 231 genes. Significantly, several up-regulated genes were linked to intracellular cAMP signaling, known to be involved in neurite outgrowth, synaptic plasticity, and neuronal survival. Differential expression of specific genes was validated by quantitative RT-PCR using independent samples. Results shed light on molecular mechanisms underlying neuroprotection by DNP and point to possible targets for development of novel therapeutics for neurodegenerative disorders.

Oroidin Inhibits the Activity of the Multidrug Resistance Target Pdr5p from Yeast Plasma Membranes

Oroidin was isolated from the marine sponge Agelas sventres and inhibited the activity and function of Pdr5p, an enzyme responsible for the multidrug resistance phenotype in Saccharomyces cerevisiae. This compound may help in the development of new drugs that reverse this dangerous phenotype of pathogenic yeast and fungi.