25 resultados para Naphthalene-2-sulfonic acid

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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UV filters belong to a group of compounds that are used by humans and are present in municipal waste-waters, effluents from sewage treatment plants and surface waters. Current information regarding UV filters and their effects on fish is limited. In this study, the occurrence of three commonly used UV filters - 2-phenylbenzimidazole-5-sulfonic acid (PBSA), 2-hydroxy-4-methoxybenzophenone (benzophenone-3, BP-3) and 5-benzoyl-4-hydroxy-2-methoxy-benzenesulfonic acid (benzophenone-4, BP-4) - in South Bohemia (Czech Republic) surface waters is presented. PBSA concentrations (up to 13μgL(-1)) were significantly greater than BP-3 or BP-4 concentrations (up to 620 and 390ngL(-1), respectively). On the basis of these results, PBSA was selected for use in a toxicity test utilizing the common model organism rainbow trout (Oncorhynchus mykiss). Fish were exposed to three concentrations of PBSA (1, 10 and 1000µgL(-1)) for 21 and 42 days. The PBSA concentrations in the fish plasma, liver and kidneys were elevated after 21 and 42 days of exposure. PBSA increased activity of certain P450 cytochromes. Exposure to PBSA also changed various biochemical parameters and enzyme activities in the fish plasma. However, no pathological changes were obvious in the liver or gonads.

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The use of self-etch primers has increased steadily because of their time savings and greater simplicity; however, overall benefits and potential disadvantages and harms have not been assessed systematically. In this study, we reviewed randomized controlled trials to assess the risk of attachment failure, bonding time, and demineralization adjacent to attachments between 1-stage (self-etch) and 2-stage (acid etch) bonding in orthodontic patients over a minimum follow-up period of 12 months.

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Liver receptor homolog-1 (LRH-1) is a nuclear receptor involved in intestinal lipid homeostasis and cell proliferation. Here we show that haploinsufficiency of LRH-1 predisposes mice to the development of intestinal inflammation. Besides the increased inflammatory response, LRH-1 heterozygous mice exposed to 2,4,6-trinitrobenzene sulfonic acid show lower local corticosterone production as a result of an impaired intestinal expression of the enzymes CYP11A1 and CYP11B1, which control the local synthesis of corticosterone in the intestine. Local glucocorticoid production is strictly enterocyte-dependent because it is robustly reduced in epithelium-specific LRH-1-deficient mice. Consistent with these findings, colon biopsies of patients with Crohn's disease and ulcerative colitis show reduced expression of LRH-1 and genes involved in the production of glucocorticoids. Hence, LRH-1 regulates intestinal immunity in response to immunological stress by triggering local glucocorticoid production. These findings underscore the importance of LRH-1 in the control of intestinal inflammation and the pathogenesis of inflammatory bowel disease.

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OBJECTIVE Crohn's disease is a chronic inflammatory process that has recently been associated with a higher risk of early implant failure. Herein we provide information on the impact of colitis on peri-implant bone formation using preclinical models of chemically induced colitis. METHODS Colitis was induced by intrarectal instillation of 2,4,6-trinitro-benzene-sulfonic-acid (TNBS). Colitis was also induced by feeding rats dextran-sodium-sulfate (DSS) in drinking water. One week after disease induction, titanium miniscrews were inserted into the tibia. Four weeks after implantation, peri-implant bone volume per tissue volume (BV/TV) and bone-to-implant contacts (BIC) were determined by histomorphometric analysis. RESULTS Cortical histomorphometric parameters were similar in the control (n = 10), DSS (n = 10) and TNBS (n = 8) groups. Cortical BV/TV was 92.2 ± 3.7%, 92.0 ± 3.0% and 92.6 ± 2.7%. Cortical BIC was 81.3 ± 8.8%, 83.2 ± 8.4% and 84.0 ± 7.0%, respectively. No significant differences were observed when comparing the medullary BV/TV and BIC (19.5 ± 6.4%, 16.2 ± 5.6% and 15.4 ± 9.0%) and (48.8 ± 12.9%, 49.2 ± 6.2 and 41.9 ± 11.7%), respectively. Successful induction of colitis was confirmed by loss of body weight and colon morphology. CONCLUSIONS The results suggest bone regeneration around implants is not impaired in chemically induced colitis models. Considering that Crohn's disease can affect any part of the gastrointestinal tract including the mouth, our model only partially reflects the clinical situation.

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The recrystallization behavior of Cu films electrodeposited under oscillatory conditions in the presence of plating additives was studied by means of secondary ion mass spectrometry (SIMS) and focused ion beam analysis. When combined with bis-(sodium-sulfopropyl)-disulfide (SPS), Imep levelers (polymerizates of imidazole and epichlorohydrin) show characteristic oscillations in the galvanostatic potential/time transient measurements. These are related to the periodic degradation and restoration of the active leveler ensemble at the interface. The leveler action relies on adduct formation between the Imep and MPS (mercaptopropane sulfonic acid)-stabilized CuI complexes that appear as intermediates of the copper deposition when SPS is present in the electrolyte. SIMS depth profiling proves that additives are incorporated into the growing film preferentially under transient conditions during the structural breakdown of the leveler ensemble and its subsequent restoration. In contrast, Cu films electrodeposited in the presence of a structurally intact Imep–CuI–MPS ensemble remain largely contamination free.

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The aim of the study was to assess the thickness of softened enamel removed by toothbrushing. Human enamel specimens were indented with a Knoop diamond. Softening was performed with citric acid or orange juice. The specimens were brushed in a brushing machine with a manual soft toothbrush in toothpaste slurry or in artificial saliva. Enamel loss was calculated from the change in indentation depth of the same indent before and after abrasion. Mean surface losses (95% confidence interval) were recorded in treatment groups (in nanometers): (1) citric acid, abrasion with slurry = 339 (280-398); (2) citric acid, abrasion with artificial saliva = 16 (5-27); (3) orange juice, abrasion with slurry = 268 (233-303); (4) orange juice, abrasion with artificial saliva = 14 (5-23); (5) no softening, abrasion with slurry = 28 (10-46). The calculated thickness of the softened enamel varied between 254 and 323 nm, depending on the acid used.

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Alcohol-induced liver disease (ALD) is a leading cause of nonaccident-related deaths in the United States. Although liver damage caused by ALD is reversible when discovered at the earlier stages, current risk assessment tools are relatively nonspecific. Identification of an early specific signature of ALD would aid in therapeutic intervention and recovery. In this study, the metabolic changes associated with ALD were examined using alcohol-fed male Ppara-null mouse as a model of ALD. Principal components analysis of the mass spectrometry-based urinary metabolic profile showed that alcohol-treated wild-type and Ppara-null mice could be distinguished from control animals without information on history of alcohol consumption. The urinary excretion of ethyl-sulfate, ethyl-beta-d-glucuronide, 4-hydroxyphenylacetic acid, and 4-hydroxyphenylacetic acid sulfate was elevated and that of the 2-hydroxyphenylacetic acid, adipic acid, and pimelic acid was depleted during alcohol treatment in both wild-type and the Ppara-null mice albeit to different extents. However, indole-3-lactic acid was exclusively elevated by alcohol exposure in Ppara-null mice. The elevation of indole-3-lactic acid is mechanistically related to the molecular events associated with development of ALD in alcohol-treated Ppara-null mice. This study demonstrated the ability of a metabolomics approach to identify early, noninvasive biomarkers of ALD pathogenesis in Ppara-null mouse model.

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Three fundamental types of suppressor additives for copper electroplating could be identified by means of potential Transient measurements. These suppressor additives differ in their synergistic and antagonistic interplay with anions that are chemisorbed on the metallic copper surface during electrodeposition. In addition these suppressor chemistries reveal different barrier properties with respect to cupric ions and plating additives (Cl, SPS). While the type-I suppressor selectively forms efficient barriers for copper inter-diffusion on chloride-terminated electrode surfaces we identified a type-II suppressor that interacts non-selectively with any kind of anions chemisorbed on copper (chloride, sulfate, sulfonate). Type-I suppressors are vital for the superconformal copper growth mode in Damascene processing and show an antagonistic interaction with SPS (Bis-Sodium-Sulfopropyl-Disulfide) which involves the deactivation of this suppressor chemistry. This suppressor deactivation is rationalized in terms of compositional changes in the layer of the chemisorbed anions due to the competition of chloride and MPS (Mercaptopropane Sulfonic Acid) for adsorption sites on the metallic copper surface. MPS is the product of the dissociative SPS adsorption within the preexisting chloride matrix on the copper surface. The non-selectivity in the adsorption behavior of the type-II suppressor is rationalized in terms of anion/cation pairing effects of the poly-cationic suppressor and the anion-modified copper substrate. Atomic-scale insights into the competitive Cl/MPS adsorption are gained from in situ STM (Scanning Tunneling Microscopy) using single crystalline copper surfaces as model substrates. Type-III suppressors are a third class of suppressors. In case of type-land type-II suppressor chemistries the resulting steady-state deposition conditions are completely independent on the particular succession of additive adsorption. In contrast to that a strong dependence of the suppressing capabilities on the sequence of additive adsorption ("first comes, first serves" principle) is observed for the type-IIIsuppressor. This behavior:is explained by a suppressor barrier that impedes not only the copper inter-diffusion but also the transport of other additives (e.g. SPS) to the copper surface. (C) 2011 Elsevier Ltd. All rights reserved.

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The proinflammatory cytokine IL-6 seems to have an important role in the intestinal inflammation that characterizes inflammatory bowel diseases (IBDs) such as Crohn disease and ulcerative colitis. However, little is known about the molecular mechanisms regulating IL-6 production in IBD. Here, we assessed the role of the transcriptional regulator IFN regulatory factor-4 (IRF4) in this process. Patients with either Crohn disease or ulcerative colitis exhibited increased IRF4 expression in lamina propria CD3+ T cells as compared with control patients. Consistent with IRF4 having a regulatory function in T cells, in a mouse model of IBD whereby colitis is induced in RAG-deficient mice by transplantation with CD4+CD45RB(hi) T cells, adoptive transfer of wild-type but not IRF4-deficient T cells resulted in severe colitis. Furthermore, IRF4-deficient mice were protected from T cell-dependent chronic intestinal inflammation in trinitrobenzene sulfonic acid- and oxazolone-induced colitis. In addition, IRF4-deficient mice with induced colitis had reduced mucosal IL-6 production, and IRF4 was required for IL-6 production by mucosal CD90+ T cells, which it protected from apoptosis. Finally, the protective effect of IRF4 deficiency could be abrogated by systemic administration of either recombinant IL-6 or a combination of soluble IL-6 receptor (sIL-6R) plus IL-6 (hyper-IL-6). Taken together, our data identify IRF4 as a key regulator of mucosal IL-6 production in T cell-dependent experimental colitis and suggest that IRF4 might provide a therapeutic target for IBDs.

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Gamma-radiation exposure has both short- and long-term adverse health effects. The threat of modern terrorism places human populations at risk for radiological exposures, yet current medical countermeasures to radiation exposure are limited. Here we describe metabolomics for gamma-radiation biodosimetry in a mouse model. Mice were gamma-irradiated at doses of 0, 3 and 8 Gy (2.57 Gy/min), and urine samples collected over the first 24 h after exposure were analyzed by ultra-performance liquid chromatography-time-of-flight mass spectrometry (UPLC-TOFMS). Multivariate data were analyzed by orthogonal partial least squares (OPLS). Both 3- and 8-Gy exposures yielded distinct urine metabolomic phenotypes. The top 22 ions for 3 and 8 Gy were analyzed further, including tandem mass spectrometric comparison with authentic standards, revealing that N-hexanoylglycine and beta-thymidine are urinary biomarkers of exposure to 3 and 8 Gy, 3-hydroxy-2-methylbenzoic acid 3-O-sulfate is elevated in urine of mice exposed to 3 but not 8 Gy, and taurine is elevated after 8 but not 3 Gy. Gene Expression Dynamics Inspector (GEDI) self-organizing maps showed clear dose-response relationships for subsets of the urine metabolome. This approach is useful for identifying mice exposed to gamma radiation and for developing metabolomic strategies for noninvasive radiation biodosimetry in humans.

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CONTEXT Chemical eye injuries are ophthalmological emergencies with a high risk of secondary complications and severe visual loss. Only limited epidemiological data for such injuries are available for many countries. PATIENTS AND METHODS We performed two independent studies. The cause of chemical eye injuries was assessed with a prospective questionnaire study. Questionnaires were sent to all ophthalmologists in Switzerland. A total of 163 patients (205 eyes) were included, between December 2012 and October 2014. Independent of the questionnaire study, the incidence of chemical eye injuries was assessed with a retrospective cohort study design using the database of the mandatory accident insurance. RESULTS Ophthalmological questionnaires revealed that plaster/cement (20.5%), alkaline (12.2%) and acid (10.2%) solutions caused the highest number of chemical injuries. Only 2% of all injuries were classified as grade III and none as grade IV (Roper-Hall classification). The official toxicological information phone-hotline was contacted in 4.3% of cases. Using data from the accident insurance, an incidence of chemical eye injuries of about 50/100 000/year was found in the working population. CONCLUSION Here, we present data on the involved agents of chemical eye injuries in Switzerland, and also the incidence of such injuries in the working population. This may also help to assess the need for further education programs and to improve and direct preventive measures.

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Acute promyelocytic leukaemia (APL) patients are successfully treated with all-trans retinoic acid (ATRA). However, concurrent chemotherapy is still necessary and less toxic therapeutic approaches are needed. Earlier studies suggested that in haematopoietic neoplasms, the green tea polyphenol epigallocatechin-3-gallate (EGCG) induces cell death without adversely affecting healthy cells. We aimed at deciphering the molecular mechanism of EGCG-induced cell death in acute myeloid leukaemia (AML). A significant increase of death-associated protein kinase 2 (DAPK2) levels was found in AML cells upon EGCG treatment paralleled by increased cell death that was significantly reduced upon silencing of DAPK2. Moreover, combined ATRA and EGCG treatment resulted in cooperative DAPK2 induction and potentiated differentiation. EGCG toxicity of primary AML blasts correlated with 67 kDa laminin receptor (67LR) expression. Pretreatment of AML cells with ATRA, causing downregulation of 67LR, rendered these cells resistant to EGCG-mediated cell death. In summary, it was found that (i) DAPK2 is essential for EGCG-induced cell death in AML cells, (ii) ATRA and EGCG cotreatment significantly boosted neutrophil differentiation, and 67LR expression correlates with susceptibility of AML cells to EGCG. We thus suggest that EGCG, by selectively targeting leukaemic cells, may improve differentiation therapies for APL and chemotherapy for other AML subtypes.

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ω3-polyunsaturated fatty acids (ω3-PUFAs) are known to exert anti-inflammatory effects in various disease models although their direct targets are only poorly characterized.