Interaction of bovine serum albumin (BSA) with ionic surfactants evaluated by electron paramagnetic resonance (EPR) spectroscopy

EPR spectra of 5- and 16-doxyl stearic acid nitroxide probes (5-DSA and 16-DSA, respectively) bound to bovine serum albumin (BSA) revealed that in the presence of ionic surfactants, at least, two label populations coexist in equilibrium. The rotational correlation times (tau) indicated that component I displays a more restricted mobility state, associated to the spin labels bound to the protein; the less immobilized component 2 is due to label localization in the surfactant aggregates. For both probes, the increase of surfactant concentration leads to higher motional levels of component 1 followed by a simultaneous decrease of this fraction of nitroxides and its conversion into component 2. For 10 mM cethyltrimethylammonium chloride (CTAC), the nitroxides are 100% bound to the protein, whereas at 10mM N-hexadecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (HPS) and sodium dodecyl sulfate (SDS) the fractions of bound nitroxides are reduced to 18% and 86%, respectively. No significant polarity changes were observed in the whole surfactant concentration range for component 1. Moreover, at higher surfactant concentration, component 2 exhibited a similar polarity as in the pure surfactant micelles. For 16-DSA the surfactant effect is different: at 10mM of HPS and CTAC the fractions of bound nitroxides are 76% and 49%, respectively, while at 10 mM SDS they are present exclusively in a micellar environment, consistent with 100% of component 2. Overall, both SDS and HPS are able to effectively displace the nitroxide probes from the protein binding sites. while CTAC seems to affect the nitroxide binding to a significantly smaller extent. (C) 2008 Elsevier B.V. All rights reserved.

Isoelectric Point Determination for Glossoscolex paulistus Extracellular Hemoglobin: Oligomeric Stability in Acidic pH and Relevance to Protein-Surfactant Interactions

The extracellular hemoglobin from Glossoscolex paulistus (HbGp) has a molecular mass of 3.6 M Da, It has a high oligomeric stability at pH 7.0 and low autoxidation rates, as compared to vertebrate hemoglobins. In this work, fluorescence and light scattering experiments were performed with the three oxidation forms of HbGp exposed to acidic pH. Our focus is on the HbGp stability at acidic pH and also on the determination of the isoelectric point (pI) of the protein. Our results show that the protein in the cyanomet form is more stable than in the other two forms, in the whole range. Our zeta-potential data are consistent with light scattering results. Average values apt obtained by different techniques were 5.6 +/- 0.5, 5.4 +/- 0.2 and 5.2 +/- 0.5 for the oxy, met, and cyanomet forms. Dynamic light scattering (DLS) experiments have shown that, at pH 6.0, the aggregation (oligomeric) state of oxy-, met- and cyanomet-HbGp remains the same as that at 7.0. The interaction between the oxy-HbGp and ionic surfactants at pH 5.0 and 6.0 was also monitored in the present study. At pH 5,0, below the protein pI, the effects of sodium dodecyl sulfate (SDS) and cetyltrimethylammonium chloride (CTAC) are inverted when compared to pH 7.0. For CTAC, in acid pH 5.0, no precipitation is observed, while for SDS an intense light scattering appears due to a precipitation process. HbGp interacts strongly with the cationic surfactant at pH 7.0 and with the anionic one at pH 5.0. This effect is due to the predominance, in the protein surface, of residues presenting opposite charges to the surfactant headgroups. This information can be relevant for the development of extracellular hemoglobin-based artificial blood substitutes.

Solubilizacao e interacao de pigmentos com solventes organicos e agentes tenso-ativos

A Mg e Mn-Ftalocianina (Mg e Mn-Pc) foram solubilizados à 25°C em dimetilsulfóxido (DMSO); N, N-dimetilacetamida (DMA); N,N-dimetilformamida (DMF); N-metil-formamida, formamida, piridina, o-diclorobenzeno, monoclorobenzeno, tolueno, metanol, etanol, propanol-1, propanol-2, butanol-1 e octanol-1. Alguns valores representativos obtidos para o logarítimo da absortividade molar (E) da Mn-Pc, são os seguintes: o-diclorobenzeno (E = 4,94); DMSO (E = 4,39); octanol-1 (E = 3,90). Valores correspondentes para Mg-Pc são: o-diclarobenzeno (E = 4,93); DMSO (E = 5,22) e Octanol-1 ( E = 5,06). Em função de interação com solventes, pode-se classificar a Mg-Pc como um indicador básico e a Mn-Pc como indicador ácido. Os pigmentos Mg e Mn-Pc foram também solubillzados em soluções aquosas contendo vários surfatantes à 25°C. A Mg-Pc apresentou solubilidade significativa em água contendo brometo de cetiltrimetilamônio (CTAB), Brij-35, cloreto de cetilpiridinio (CPC1), brometo de cetilpiridínio (CPBr,) Triton X-100, cloreto de metildodecilbenziltrimetilamônio, brometo de cetildimetiletilamõnio e brometo de laurilisoquinolínio. A Mn-Pc foi solúvel em soluções aquosas de Brij-35 e Triton X-100. Em função de sua interação com surfatantes a Mg-Pc é classificada como corante catiônico e a Mn-Pc como corante aniônico. O corante comercial quinóide Oil Blue A [1,4-di(isopropilarnina)-antraquinona - 9,10 foi solubilizado à 25°C em DMF, DMSO, DMA, monoclorobenzeno, benzeno, tolueno, piridina, metanol, etanol, propanol-1, propanol-2, butanol-1 e octanol-1. Foi também solubilizado em soluções aquosas de surfatantes, tais como sódio lauril-sulfato (NaLS), cloreto de cetiltrimetilamônio (CTAB), brometo de cetildimetiletilamônio, Triton X-100, cloreto de cetilpiridínio (CPCl), Brij-35, cloreto de rnetildodecilbenziltrimetilamônio e brometo de laurilisoquinolínio. Em função de suas interações com os solventes o corante é um indicador ácido-básico pouco sensível e em função de sua interação com surfatantes é um corante catiônico. 0s resultados experimentais apresentam importância teórica e prática considerando sistemas que envolvem armazenamento e transferência de energia, compostos porfirínicos, fotossíntese, fotocondutores, coletores solares, semi-condutores e processos de embelezamento e proteção de superficies de vários materiais.

Recuperação do cromo contido nas cinzas provenientes da incineração de resíduos sólidos das indústrias coureira e calçadista visando a obtenção de cromato de sódio (VI)

O processo de transformação da pele em couro envolve uma seqüência complexa de reações químicas e processos mecânicos, no qual o curtimento representa fundamental estágio, por propiciar à pele características como qualidade, estabilidade hidrotérmica e excelentes propriedades para uso. O sulfato básico de cromo trivalente é o agente curtente predominantemente empregado no curtimento de peles em todo o mundo. É produzido a partir do cromato de sódio, industrialmente obtido do minério de cromo. Consideráveis quantidades de resíduos sólidos contendo cromo são geradas pelas indústrias coureira e calçadista. Estes resíduos tem sido motivo de preocupação constante, uma vez que são considerados perigosos devido a presença do cromo. O processo de incineração destes resíduos é uma importante alternativa a ser considerada, em decorrência de suas características de redução de massa, volume e possibilidade de aproveitamento da energia térmica dos gases de combustão. O processo de incineração dos resíduos das indústrias coureira e calçadista dá origem a cinzas contendo cerca de 40% de cromo que pode ser submetida a um processo de recuperação. Este trabalho apresenta os resultados da pesquisa sobre a utilização das cinzas, provenientes da incineração dos resíduos sólidos da indústria coureira e da indústria calçadista, para a produção de cromato de sódio(VI). No processo de planejamento e de condução dos experimentos foram utilizadas as técnicas de Planejamento Fatorial 2k, Metodologia de Superfície de Resposta e Análise de Variância na avaliação da produção de cromato de sódio(VI). Os fatores investigados foram: temperatura, taxa de aquecimento, tempo de reação, vazão de ar e quantidade de dolomita. A partir das variáveis selecionadas identificaram-se como parâmetros importantes a temperatura e a taxa de aquecimento. As superfícies de resposta tridimensionais obtidas a partir dos modelos de segunda ordem ajustados aos dados experimentais, apresentaram o comportamento do efeito conjugado dos fatores temperatura e taxa de aquecimento sobre a variável resposta grau de oxidação, desde a temperatura de inicio da reação química até a temperatura limite utilizada industrialmente. As condições de operação do processo de produção de cromato de sódio(VI) foram otimizadas. Os níveis ótimos dos fatores de controle aplicados as cinzas dos resíduos da indústria calçadista, geradas em uma planta piloto com incinerador de leito fixo, com tecnologia de gaseificação e combustão combinadas, apresentaram um grau de oxidação superior a 96% para as cinzas coletadas no ciclone e de 99,5% para as cinzas coletas no reator de gaseificação. Os resíduos sólidos, as cinzas e o produto de reação foram caracterizados por análises químicas, fluorescência de raio-X, microscopia eletrônica de varredura e difração de raio-X.

Bacteriologic investigation of the effects of sodium hypochlorite and chlorhexidine during the endodontic treatment of teeth with apical periodontitis

SIQUEIRA JR. et al. Bacteriologic investigation of the effects of sodium hypochlorite and chlorhexidine during the endodontic treatment of teeth with apical periodontitis. Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod., v. 104, n. 1, p. 122-130, 2007.

Effect of Tripanosomicide Benznidazole (Rochagan®) on the Biodistribution of Sodium Pertechnetate (Na99mTcO4) in Wistar Rats

Benznidazole, a drug with specific anti-Trypanosoma cruzi activity, is used in the treatment of Chagas’ disease. The radiopharmaceutical sodium pertechnetate (Na99mTcO4) is used to obtain diagnostic images of the stomach, thyroid, parathyroids, salivary glands, brain and in the study of esophageal reflux and blood flow. This study aimed at evaluating in vivo the influence of benznidazole treatment on the sodium pertechnetate biodistribution in Wistar rats. The percentage of radioactivity per gram (%ATI/g) of various organs (brain, heart, esophagus, stomach, small intestine, large intestine, spleen, liver, muscle and blood) was determined. Comparing the treated rats with the controls, we observed that sodium pertechnetate biodistribution did not change when administered to rats treated for thirty days with benznidazole

Biodistribution of the Radiopharmaceutical Sodium Pertechnetate after Biliopancreatic Bypass with a Duodenal Switch

Study with the purpose to examine the effects of duodenal switch (DS), regularly performed in morbidly obese patients, on biodistribution of sodium pertechnetate in several organs of rats. There was no early or late mortality in either rats groups. The values of percent radioactivity per gram of tissue (%ATI/g), showed no significant difference in liver, stomach, small bowel, duodenum, kidney, heart, bladder, bone and brain, when compared the DS rats with sham and controls rats. A postoperative significant increase (p<0.05) in mean %ATI/g levels was observed in spleen, pancreas and muscle in group DS rats, as compared to group S and C rats. In the lung there was an increase and in thyroid a decrease in mean %ATI/g of DS rats, when compared to sham rats (p<0.05). In conclusion, the biliopancreatic diversion with duodenal switch in rats modified the biodistribution of sodium pertechnetate in thyroid, lung, pancreas, spleen and muscle

Biodistribution of the Radiopharmaceutical Technetium- 99m-Sodium Phytate in Rats After Splenectomy

Drugs and surgery can interfere with the biodistribution of radiopharmaceuticals and data about the effect of splenectomy on the metabolism of phytate-Tc-99m are scarce. This study aimed at evaluating the interference of splenectomy on phytate-Tc-99m biodistribution and liver function in rats. The SP group rats (n=6) underwent splenectomy. In group C (control) the animals were not operated on. After 15 days, all rats were injected with 0.1mL of Tc-99m-phytate via orbital plexus (0.66MBq). After 30 minutes, liver samples were harvested, weighed and the percentage of radioactivity per gram (%ATI-g) was determined by a Wizard Perkin-Elme gama counter. The ATI%-g in splenectomized rats (0.99±0.02) was significantly higher than in controls (0.4±0.02), (p=0.034). ALT, AST and HDL were significantly lower in SP rats (p= 0.001) and leukocytosis was observed in SP rats. In conclusion, splenectomy in rats changed the hepatic biodistribution of Tc-99m-phytate and liver enzimatic activity

Biodistribution of the radiophamarceutical sodium pertechnetate (Na99mTcO4) after massive small bowel resection in rats

To evaluate the biodistribution of sodium pertecnetate (Na99mTcO4) in organs and tissues, the morphometry of remnant intestinal mucosa and ponderal evolution in rats subjected to massive resection of the small intestine. Methods: Twenty-one Wistar rats were randomly divided into three groups of 7 animals each. The short bowel (SB) group was subjected to massive resection of the small intestine; the control group (C) rats were not operated on, and soft intestinal handling was performed in sham rats. The animals were weighed weekly. On the 30th postoperative day, 0.l mL of Na99mTcO4, with mean activity of 0.66 MBq was injected intravenously into the orbital plexus. After 30 minutes, the rats were killed with an overdose of anesthetic, and fragments of the liver, spleen, pancreas, stomach, duodenum, small intestine, thyroid, lung, heart, kidney, bladder, muscle, femur and brain were harvested. The biopsies were washed with 0.9% NaCl.,The radioactivity was counted using Gama Counter WizardTM 1470, PerkinElmer. The percentage of radioactivity per gram of tissue (%ATI-g) was calculated. Biopsies of the remaining jejunum were analysed by HE staining to obtain mucosal thickness. Analysis of variance (ANOVA) and the Tukey test for multiple comparisons were used, considering p<0.05 as signifi cant. Results: There were no signifi cant differences in %ATI-g of the Na99mTcO4 in the organs of the groups studied (p>0.05). An increase in the weight of the SB rats was observed after the second postoperative week. The jejunal mucosal thickness of the SB rats was signifi cantly greater than that of C and sham rats (p<0.05). Conclusion: In rats with experimentally-produced short bowel syndrome, an adaptive response by the intestinal mucosa reduced weight loss. The biodistribution of Na99mTcO4 was not affected by massive intestinal resection, suggesting that short bowel syndrome is not the cause of misleading interpretation, if an examination using this radiopharmaceutical is indicated

Purificação e caracterização de uma ß-N-acetillhexosaminadase extraída do mamífero marinho Sotalia fluviatilis

This report shows 2232 times purification of a βNAcetylhexosaminidase from hepatic extracts from the sea mammal Sotalia fluviatilis homogenate with final recovery of 8,4%. Sequenced steps were utilized for enzyme purification: ammonium sulfate fractionation, Biogel A 1.5 m, chitin, DEAESepharose and hydroxyapatite chromatographies. The protein molecular mass was estimated in 10 kDa using SDSPAGE and confirmed by MALDITOF. It was found to have an optimal pH of 5.0 and a temperature of 60°C. Using pnitrophenylNAcetylβDglycosaminide apparent Km and Vmax values were of 2.72 mM and 0.572 nmol/mg/min, respectively. The enzyme was inhibited by mercury chloride (HgCl2) and sodium dodecil sulfate (SDS)

Efeito de frações obtidas da fucoidana de Fucus vesiculosus em modelo experimental de artrite induzida por Zymosan

The fucoidan from Fucus vesiculosus is known for having diverse biological properties. This study analyzed the therapeutic action of populations of commercial fucoidan (F. vesiculosus) on zymosan-induced arthritis. Three populations of fucoidan were obtained after acetone fractionation; these were denominated F1 (52.3%), F2 (36.7%) and F3 (10.7%). Chemical analyses showed that F1 contained the largest amount of sulfate ion. The electrophoretic profile shows that the commercial or total fucoidan (TF), different from the other fucoidans and from glycosaminoglycan patterns, is quite polydisperse, which indicates that it is composed of a mixture of sulfate polysaccharides. On the other hand, the fucoidans obtained from TF showed only an electrophoretic band with much lower polydispersion than that observed for TF. Fucoidan F2 showed a migration between fucoidans F1 and F3. Owing to the small amount of mass obtained from F3, we used only fucoidans F1 and F2 in the induced arthritis tests. After 1 hour of induction, we administered F1 or F2 (10, 25 and 50 mg/kg i.p.) or diclofenac sodium (10 mg/kg i.p.) or lumiracoxib (5 mg/kg o.a.) or L-NAME (30 mg/kg i.p.). After 6 hours, we performed analyses of cell influx and nitrite levels in addition to histopathological analysis. Fucoidans F1 and F2 were more potent both in decreasing the number of leukocytes and the amount of nitric oxide found in the synovial fluid. This indicates that the anti-inflammatory mechanism of these fucoidans is not only related to selectin block, but also to nitric oxide synthesis inhibition

Desenvolvimento de argamassa para restauração utilizando resíduo do polimento do porcelanato

The coatings mortars are essential elements of building structures because they execute an important role in protecting walls and are particularly exposed to aggressive action responsible for its degradation over time. The importance of wall coverings has been the subject of discussion and analysis in the conservation and rehabilitation of old buildings. Are sometimes removed and replaced with inappropriate solutions of constructive point of view or architecture. The most commonly used coatings on walls of old buildings is based on traditional hydraulic lime mortars. The present study aims at the formulation of new lime- based mortars and aerial fine aggregate, in order to contribute to a better field of conservation and restoration mortar coating of old buildings. Residue was used for polishing porcelain as fine aggregate, replacing the aggregate (sand), in percentages 05-30% by mass. We conducted a thorough evaluation of the mortar properties in fresh and hardened state by comparing the performance of the same with a reference mortar. The residue used was characterized as the density, bulk density, and particle size laser, scanning electron microscopy, X-ray diffraction and X-ray fluorescence. Formulations were produced 7, 6 with residue and one commonly used formulation, which served as a reference. In the formulations of lime mortars air (hydrated lime powder CH-I) has been adopted a stroke volume (1:3) with constant binder, was varied and the water / binder and aggregate and waste. For evaluation of mortars fresh, proceeded to consistency analysis, specific gravity, water retention and air content embedded. In the hardened state assays were performed in specific gravity, water retention, modulus of elasticity, tensile strength in bending, compressive strength, water absorption by capillary action, adhesion, tensile strength, resistance to shrinkage and salts by of crystallization trials with resources chloride solution, nitrate and sulfate all sodium in prismatic at 90 days of age, in addition to the micro structural analysis of mortars. Based on the results we can see that the mortar formulated with 10% content of waste and the reference free retraction feature more stable closer to neutrality. The composition of 10% was obtained better performance against the action of the salt crystallization. The mortar with 15% residue obtained better density, lower air content embedded and high capacity for water retention developing good workability. The replacement of 20% of waste generates a satisfactory utilization of resistance to compression, flexion and traction grip the base. And, finally, it can be seen that the mortar with 10, 15 and 20% residual show, in principle, good suitability as coatings, thus enabling a final result consistent with durability, workability and aesthetics developing therefore a material with better performance to repair or replace existing mortars in old buildings

Efeitos do potencial probiótico Enterococcus faecium 32 e de sua associação com o extrato da alga marinha Caulerpa mexicana no tratamento de colite experimental murina

Ulcerative colitis comprising an inflammatory bowel disease, whose most severe consequence is the development of intestinal neoplasia. The drugs currently used to treat the disease trigger a variety of serious adverse effects and are not effective in many cases. Recent studies demonstrated the effectiveness of natural products for the treatment of inflammatory processes. Seaweed extracts and their purified products have shown protective effects in models of inflammation and the association of traditional therapies with probiotics has significantly improved the clinical symptoms of ulcerative colitis. Therefore, the aims of this study include evaluating the potential effects of the use of probiotic strain Enterococcus faecium 32 (Ef32), the methanolic extract of the green seaweed Caulerpa mexicana (M.E.) and their concomitant administration in a murine model of colitis induced by dextran sodium sulfate (DSS). Accordingly, C57BL /6 mice were pretreated orally with Ef32 (109 CFU/ml) for seven days. In the seven days following, the colitis was induced by administration of 3% DSS (w/v) diluted in the animals drinking water. During this period, animals were treated daily with Ef32 and the M.E. (2.0 mg/kg) every other day by intravenous route. The development of colitis was monitored by the disease activity index (DAI), which takes into account the loss of body weight, consistency and presence of blood in stools. After euthanasia, the colon was removed, its length measured and tissue samples were destined for histological analysis and culture for cytokine quantification. The levels of cytokines in the culture supernatant of the colon were measured by ELISA. The treatments with the probiotic Ef32 or the M.E. alone or the combination of these two substances provoked significant improvement as to weight loss and DAI, and prevented the shortening of the colon in response to DSS. The isolated treatments triggered a slight improvement in intestinal mucosal tissue damage. However, their combination was able to completely repair the injury triggered by DSS. The association was also able to reduce the levels of all the cytokines analyzed (IFN-γ, IL-4, IL-6, IL-12, IL-17A and TNF-α). On the other hand, the treatment with Ef32 did not interfere with the levels of TNF-α, whereas treatment with M.E. did not alter the levels of IL-6. Moreover, the treatment with Ef32 not interferes in TNF-α levels, whereas treatment with M.E. did not alter the levels of IL-6. Therefore, the potential probiotic Ef32 and M.E. and especially when these samples were associated proved promising alternatives in the treatment of ulcerative colitis as demonstrated in an experimental model because of its beneficial effects on morphological and clinical parameters, and by reducing the production of proinflammatory cytokines of Th1, Th2 and Th17

Determination of potassium and sodium in an ash sample by gamma-ray spectroscopy

Neutron activation analysis and gamma-ray spectroscopy were used to determine the quantity of potassium and sodium in an ash sample of Tabebuia sp bombarded with thermal neutrons. These techniques, widely applied in nuclear physics, can be used in the context of wood science as an alternative for the usual physical chemistry methods applied in this area. The quantity of K and Na in an 8.60 +/- 0.10 mg of ash was determined as being 1.3 +/- 0.3 mg and 11.0 +/- 1.8 mu g, respectively. The ratio of Tabebuia sp converted into ash was also determined as 0.758 +/- 0.004%.

Rheological Properties of a Sodium Bentonite and Lactose Aqueous Dispersion

Aim of this paper is show the viscosity measure of a sodium bentonite-water-lactose mixture and your rheological behaviour. This analysis showed the formation of tridimensional structure type and formation of stratified silicate/lactose, this occurred due to different concentrations of organic products into mixture and due to a difference of rotation during viscosity measument. Formation of networks is a consequence of the attraction between the silicate layers in water-lactose mixture. In the present work aqueous solutions of lactose with concentration of 7%, 5%, 3%, 1% and 0% (wt %) were used.