Biomphalaria glabrata infected with Angiostrongylus cantonensis: Proteomic changes in the snail host.

Angiostrongylus cantonensis is the main cause of human eosinophilic meningitis. Humans are accidental hosts, becoming infected due to ingestion of raw intermediate (snails and slugs) or paratenic hosts. Once ingested, the larvae migrate towards the brain where they die, causing the disease. To develop better mollusk control strategies, it is important to first understand what happens in the snail during infection, therefore our purpose was to characterize proteomic, metabolic and immunologic changes in Biomphalaria glabrata 24 h after infection with A. cantonensis. For this purpose, proteins were extracted from infected and uninfected snails and analyzed through mass spectrometry. Hemolymph was also collected, the number of hemocytes was counted and urea, nitric oxide, calcium, glycogen levels as well as alanine and aspartate aminotransferases activities were assessed. The cephalopodal region and gonad-digestive gland complex were dissected and their glycogen content was measured. After infection with A. cantonensis, we observed an increase of hemocytes and granulocytes as well as an increase in hemoglobin type 2 proteins. Temptin-like protein was also found up-regulated in infected snails. Several proteins with structural function (such as myosin heavy chain - striated muscle - like and protein LOC106059779 with ADAM/reprosolin domain) were also differentially expressed, suggesting loss/damage of internal tissues. Increase in phosphoglycerate mutase indicates an increase in glycolysis, possible to compensate the increase in energetic needs. Consequently, there is a decrease in glycogen reserves, particularly in the gonad - digestive gland complex.

Photolysis of parabens using medium-pressure mercury lamps: Toxicity effects in MCF7, Balb/c 3T3 cells and Ceriodaphnia dubia.

Degradation studies of the propylparaben (PrP), butylparaben (BuP) and of the propylparaben-butylparaben mixture (PrP-BuP) in deionized water and surface river water was investigated as a function of pH and initial concentration of the reactants using a medium-pressure mercury lamp. The photolysis of parabens (concentration ranging from 5 to 30 mg L-1) followed apparent pseudo-first-order kinetics, with rate constants (k) in deionized water and surface river water changed from 1.80 × 10-1 to 3.68 × 10-2 min-1 and 1.43 × 10-1 to 1.45 × 10-2 min-1, respectively. Degradation reaction was faster at pH 5 in comparison with pH 7 or 11. The photolysis of parabens was greater than 91%, with low mineralization (26.15%) observed in acidic medium after 95 min. Analysis by chromatography coupled to mass spectrometry (LC-MS/MS) showed that only one product was generated during the degradation reaction and has UV bands similar to 3,4-dihydroxybenzoic acid. Estrogenic activity tests showed that non-degraded parabens stimulated the growth of breast adenocarcinoma (MCF-7) cells and this effect was evaluated after the photolysis. Cytotoxicity assays using fibroblasts cells (Balb/C 3T3 clone A31) indicated that the parental compounds and degradation products were not cytotoxic. On the contrary, non-degraded parabens were toxic to Ceriodaphnia dubia, but the product of photolysis was not. Overall, the photolytic method presented was able to degrade these parabens providing safe and non-estrogenic reaction product.

Cyanate as an Active Precursor of Ethyl Carbamate Formation in Sugar Cane Spirit.

The thermodynamic and kinetic aspects of ethyl carbamate (EC) formation through the reaction between cyanate and ethanol were investigated. The rate constant values for cyanate ion decay and EC formation are (8.0 ± 0.4) × 10(-5) and (8.9 ± 0.4) × 10(-5) s(-1), respectively, at 25 °C in 48% aqueous ethanolic solution at pH 4.5. Under the investigated experimental conditions, the rate constants are independent of the ethanol and cyanate concentrations but increase as the temperature increases (ΔH1(⧧) = 19.4 ± 1 kcal/mol, ΔS1(⧧) = −12.1 ± 1 cal/K, and ΔG1(⧧) = 23.0 ± 1 kcal/mol) and decrease as the solution pH increases. According to molecular modeling (DFT) that was performed to analyze the reaction mechanism, the isocyanic acid (HNCO) is the active EC precursor. The calculated ΔG1(⧧), ΔH1(⧧), and ΔS1(⧧) values are in very good agreement with the experimental ones.

Profiles of polycyclic aromatic hydrocarbons in Brazilian sugar cane spirits: discrimination between Cachaças produced from nonburned and burned sugar cane crops.

Cachaça may be contaminated by a remarkable presence of polycyclic aromatic hydrocarbons (PAHs) when the sugar cane crop used for its production is burned before harvesting. The analysis of 15 PAHs by liquid chromatography coupled to a fluorescence detector in 131 cachaça samples from burned and nonburned sugar cane crops is reported. Average contents of 21.1 and 1.91 microg L(-1) for total PAHs were observed for cachaças originating from burned and nonburned sugar cane plantations, respectively. The main difference between these two classes of cachaças is in the quantitative profile of the most potent carcinogenic PAH, benzo[a]pyrene, which is more abundant in cachaça produced from burned sugar cane crops (4.54 x 10(-2) microg L(-1)) than in cachaça produced from nonburned crops (9.02 x 10(-3) microg L(-1)). The contents of benzo[a]pyrene in both classes of cachaça are lower than the legal limit established by the European Union (EU) at 2.00 microg L(-1) for food products. In relation to the total PAH content suggested by the German Society for Fat Science, both cachaças from burned (21.1 microg L(-1)) and nonburned crops (1.91 microg L(-1)) are below the limit (25 microg L(-1)) for total PAH content. The analytical data for PAHs, when treated through the multivariate statistical methods principal component analysis and canonical discriminant analysis, provide a very good distinction between samples produced from burned and nonburned sugar cane crops with a certainty of 98.1%.