Early cytotoxic and genotoxic effects of atrazine on Wistar rat liver: A morphological, immunohistochemical, biochemical, and molecular study

Risk assessments suggest that intermediate and long-term exposure to triazine herbicides and its metabolites through water can cause severe damage to human health. The objective of this study was to investigate the possible effects of atrazine on Wistar rats submitted to subacute treatment. For this purpose, the activity of catalase and alanine aminotransferase was quantified, and the effect of the herbicide on cell membranes was examined based on the measurement of lipid peroxidation and consequent formation of malondialdehyde and on the mRNA expression of antioxidant enzymes (Mn-superoxide dismutase [SOD] and GSTM1) and connexins. In addition, we evaluated histopathological alterations in the liver, cellular expression of SOD and glutathione (GST), activation of heat shock proteins (HSPs) by immunohistochemistry, and the induction of apoptosis. The genotoxic potential of the herbicide was investigated by the micronucleus test in bone marrow smears. Adult male Wistar rats were treated with an aqueous solution of atrazine at a concentration of 400 mg/kg/day, by gavage, for 14 consecutive days. Control groups were also included. The results showed an increase of catalase levels and maintenance of the expression of antioxidant enzymes (SOD and GST). In addition, lipid peroxidation, hepatic tissue degeneration, activation of HSP90, increased levels of connexin mRNA, and genotoxicity were observed. In conclusion, atrazine induced early hepatic oxidative stress that triggered defense mechanisms to maintain the morphophysiological integrity of the liver. Further studies are needed to better understand the effects of this herbicide on human health. (C) 2011 Elsevier B.V. All rights reserved.

Quercetin-PVP K25 solid dispersions: Preparation, thermal characterization and antioxidant activity

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Characterization of dense lead lanthanum titanate ceramics prepared from powders synthesized by the oxidant peroxo method

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Use of Biopolymeric Membranes for Adsorption of Paraquat Herbicide from Water

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of the surfactant nature on the thermo-stability of surface modified SnO2 nanoparticles

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Bone repair using mineral trioxide aggregate combined to a material carrier, associated or not with calcium hydroxide in bone defects

Mineral trioxide aggregate (MTA) is a powder aggregate containing mineral oxides with a good biological action and may facilitate the regeneration of the periodontal ligament and formation of bone. Calcium hydroxide demonstrates antibacterial properties, enhances tissue dissolution, and induces bone formation. The objective of this study was to evaluate the MTA in the bone healing process and verify if the calcium hydroxide P.A. can improve and accelerate this process. It was used forty rnale Wistar rats, which were divided into two groups, considering or not the use of calcium hydroxide P.A. solution before treatment. Thus, each one of these groups was divided in four groups with five animals each, according to the treatment and the defect filled by: animal's coagulum, monoolein gel, MTA in aqueous solution, and MTA combined with monoolein gel. After 10 days, the animals were perfused and the right hemimandibles removed for histological analysis. Statistical analysis of the data showed significant difference between all analyzed groups when it was made comparisons using or not calcium hydroxide P.A. (p < 0.0001). There was found statistical difference between the groups that was inserted or not MTA, independently the calcium hydroxide application (p < 0.05). Results showed that the MTA used was able to induce bone regeneration and had its action optimized when combined to calcium hydroxide P.A. (C) 2007 Elsevier Ltd. All rights reserved.

Synthesis, characterization, crystal structure, and biological studies of vanadium complexes with glycolic acid

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Preparation and properties as positive electrodes of PANI-LiNi0.8Co0.2O2 nanocomposites

PANI-LiNi0.8Co0.2O2 nanocomposite material with improved properties as positive electrode was prepared by a new synthesis method. In a first step, LiNi0.8Co0.2O2 mixed oxide in the form of a fine powder was dispersed in aniline and this suspension was sprayed on the surface of an aqueous solution of HCl and ammonium peroxodisulfate. The resulting PANI-LiNi0.8Co0.2O2 nanocomposite is spontaneously formed by polymerization of the aniline molecules present in the drops together with small particles of the oxide. This method induces the formation of nanocomposites showing a better distribution of the oxide particles in the polymer matrix than that observed in related PANI-LiNi0.8Co0.2O2 microcomposites prepared under ultrasound irradiation to disperse the oxide particles during PANI polymerization. Measurements of electrical conductivity and zeta potential, as well as structural characterization of PANI-LiNi0.8Co0.2O2 nanocomposites, reveal the existence of relatively strong interactions between the conducting polymer and the oxide particles. This feature determines higher values of the electrical conductivity (0.5 S cm(-1)) and of the average operative voltage (3.6 V), as well as of other technological parameters of the nanocomposite when it is used as the positive electrode of rechargeable lithium batteries, in comparison to those of the related microcomposite materials already reported.

Urea-Based Synthesis of Zinc Oxide Nanostructures at Low Temperature

The preparation of nanometer-sized structures of zinc oxide (ZnO) from zinc acetate and urea as raw materials was performed using conventional water bath heating and a microwave hydrothermal (MH) method in an aqueous solution. The oxide formation is controlled by decomposition of the added urea in the sealed autoclave. The influence of urea and the synthesis method on the final product formation are discussed. Broadband photoluminescence (PL) behavior in visible-range spectra was observed with a maximum peak centered in the green region which was attributed to different defects and the structural changes involved with ZnO crystals which were produced during the nucleation process.

Morfologia macroscópica e topografia anatômica do intestino grosso da paca (Cuniculus paca Linnaeus, 1766)

Exploring the potential of using the paca as livestock involves understanding the morphophysiology of its digestive tract so its nutrition can be properly managed. The morphological and anatomical aspects of the large intestine of this species were investigated by inspecting material that was fresh and fixed in an aqueous solution of 10% formaldehyde. The material was provided by the Setor de Animais Selvagens do Departamento de Zootecnia da Faculdade de Ciencias Agrarias e Veterinarias de Jaboticabal - UNESP (FCAV - UNESP). The large intestine of the paca is formed by cecum, colon and rectum, and is located in the abdominal and pelvic cavity near the third or fourth lumbar vertebrae. It was found, in the 10 samples analyzed, that there was no change in the pattern of this arrangement and that this pattern resembles that of mammals in general.

About the arterial blood vessels pelvic opossum's (Didelphis albiventris) behaviour

The work consists of the study of 20 opossums (Didelphis albiventris); 7 females and 13 males, adults, natives of Jaboticabal county proceeding to a canulation and injection of the arterial system with neoprene latex-650 in the aorta artery (full-blooded). Right away the preparations were fixed by a 10% formaldehyde aqueous solution and afterwards dissected and formed a scheme. The analysis of the pieces showed that in the opossum, the end of the aorta always divides in the common iliac artery, right and left sides, both originating the external and internal iliac artery, on the right and left sides. The medium sacral artery results, medianly, from the aorta division's angle in 2 common iliac arteries in 8 cases (40% - 6 males and 2 females); this vessel comes from the left common iliac artery in 7 animals (35% - 5 males and 2 females) or comes from the right common iliac artery, in 5 preparations (25% - 3 females and 2 males). The deep iliac circumflex artery is born by the common iliac artery from the right side in 10 preparations (50% - 6 males and 4 females), can appear as well, concomitantly with the external and internal iliac artery, from the right side in 9 pieces (45% - 6 males and 3 females) and further from the right this vessels can emerge from the external iliac artery, in 1 case only (5% - 1 male).

Synthesis and characterization of ruthenium complexes immobilized on poly(4-vinylpyridine)

The [Ru(NH3)5(H2O)]2+ and trans-[Ru(NH3)4SO2(H2O)]2+ complexes ions were immobilized on poly(4-vinylpyridine) (4-PVP) through reactions in aqueous solutions. The stability of the imobilized complexes was checked in aqueous solution in the pH 2.0-8.0 range. The number of pyridinic nitrogens in the polymer 4-PVP is 2.80±0.05 mmol/g according to nitrogen elemental analysis. Potentiometric titration experiments showed that the accessible nitrogen, in aqueous medium, was 0.94±0.02 mmol/g with a p Ka value of 7.4±0.2. In addition, ruthenium and sulfate analysis has demonstrated that about 15% of the accessible nitrogen sites are able to coordinate to the metal centers. The characterization of the immobilized complexes was made through diffuse electronic and infrared spectroscopies and differential pulse and cyclic voltammetries. © 1993 Plenum Publishing Corporation.

Sorption and preconcentration of some heavy metals by 2-mercaptobenzothiazole-clay

2-Mercaptobenzothiazole loaded on previously treated clay was prepared, characterized and used for sorption and preconcentration of Hg(II), Pb(II), Zn(II), Cd(II), Cu(II) and Mn(II) from an aqueous solution. The support used was a natural clay previously treated with sulphuric acid solution. Adsorption isotherms of metal ions from aqueous solutions as function of pH were studied at 298 K. Conditions for quantitative retention and elution were established for each metal by batch and column methods. The chemically treated clay was very selective to Hg(II) in solution in which Zn(II), Cd(II), Pb(II), Cu(II) and Mn(II) were also present. © 1995.

Spectroscopic study of the interaction of Nd3+ with amino acids: Phenomenological 4f-4f intensity parameters

We have studied the bevahior of the phenomenological 4f-4f intensity parameters in compounds of the Nd ion with glycine, L-aspartic acid, L-glutamic acid, L-histidine, DL-malic acid and Aspartame™ in aqueous solution, as a function of the pK values and partial charges on the oxygens of the carboxylate groups of these molecules. The results are discussed and qualitatively interpreted in terms of the forced electric dipole and dynamic coupling mechanisms of the 4f-4f intensities, thus indicating that the forced electric dipole mechanism is dominant.

Study of water and dimethylformamide interaction by computer simulation

Monte Carlo simulations of water-dimethylformamide (DMF) mixtures were performed in the isothermal and isobaric ensemble at 298.15 K and 1 atm. The intermolecular interaction energy was calculated using the classical 6-12 Lennard-Jones pairwise potential plus a Coulomb term. The TIP4P model was used for simulating water molecules, and a six-site model previously optimised by us was used to represent DMF. The potential energy for the water-DMF interaction was obtained via standard geometric combining rules using the original potential parameters for the pure liquids. The radial distribution functions calculated for water-DMF mixtures show well characterised hydrogen bonds between the oxygen site of DMF and hydrogen of water. A structureless correlation curve was observed for the interaction between the hydrogen site of the carbonyl group and the oxygen site of water. Hydration effects on the stabilisation of the DMF molecule in aqueous solution have been investigated using statistical perturbation theory. The results show that energetic changes involved in the hydration process are not strong enough to stabilise another configuration of DMF than the planar one.