... Bárbara N. Porto a , Corresponding Author Contact Information , E-mail The Corresponding Auth... more ... Bárbara N. Porto a , Corresponding Author Contact Information , E-mail The Corresponding Author , Caliandra A. Telli b , Tatiana P. Dutra a , Letícia S. Alves a , Marcelo T. Bozza a , Cyntia A. Fin c , Flavia V. Thiesen b and Márcia F. Renner d. ...
Frequency of intentional exposure to organic solvents has been increasing among children and adol... more Frequency of intentional exposure to organic solvents has been increasing among children and adolescents in Brazil. Analysis of benzene, toluene and xylenes (BTX) in human blood is necessary to diagnose the intentional and accidental exposure to these solvents. A method for BTX determination in blood samples by gas chromatography preceded by solid phase microextration (SPME) from headspace (HS) has been described. SPME has several advantages when compared to other extraction techniques such as simplicity, low cost and solvent-free extraction. The method presents good repeatability (precision was of 2.2-8.0%), accuracy from -4.7 to -9.4%, limit of detection <1.0 ug/mL, linearity from 1.0 to 100 ug/mL for toluene and from 5.0 to 100 ug/mL for the other solvents (R2 > 0.99), which shows to be efficient and adequate for the detection of exposure to BTX in blood samples.
Tobacco dependence reaches one‐third of the world population, and is the second leading cause of ... more Tobacco dependence reaches one‐third of the world population, and is the second leading cause of death around the world. Cotinine, a major metabolite of nicotine, is the most appropriate parameter to evaluate tobacco exposure and smoking status due to its higher stability and half‐life when compared to nicotine. The procedure involves liquid–liquid extraction, separation on a RP column (Zorbax® XDB C8), isocratic pump (0.5 mL/min of water–methanol–sodium acetate (0.1 M)–ACN (50:15:25:10, v/v/v/v), 1.0 mL of citric acid (0.034 M) and 5.0 mL of triethylamine for each liter) and HPLC‐UV detection (261 nm). The analytical procedure proved to be sensitive, selective, precise, accurate and linear (r>0.99) in the range of 5–500.0 ng/mL for cotinine. 2‐Phenylimidazole was used as the internal standard. The LOD was 0.18 ng/mL and the LOQ was 5.0 ng/mL. All samples from smoking volunteers were collected simultaneously to establish a comparison between serum, plasma, and urine. The urinary cotinine levels were normalized by the creatinine and urine density. A significant correlation was found (p<0.01) between all matrices. Results indicate that the urine normalization by creatinine or density is unnecessary. This method is considered reliable for determining cotinine in serum and plasma of smokers and in environmental tobacco smoke exposure.
Toxicon : official journal of the International Society on Toxinology, 2007
Snake venom is a complex mixture containing diverse protein components with different structures ... more Snake venom is a complex mixture containing diverse protein components with different structures and functions that are used for prey immobilization and death. Snake venoms from the family Viperidae cause pronounced local and systemic effects, such as pain, edema, hemorrhage and necrosis. Here, we investigated the enzymatic and biological activities of venoms from two Amazonian snakes, Bothriopsis bilineata and Bothriopsis taeniata. Both venoms presented high enzymatic activities for proteases kallikrein, thrombin and plasmin, low levels of trypsin, cathepsin C and leucine aminopeptidase activities, while lacked acetylcholinesterase activity. B. taeniata and B. bilineata crude venoms caused inflammation inducing neutrophil recruitment into peritoneal cavity of mice 4h after injection. Neutrophil recruitment induced by B. taeniata venom was accompanied by hemorrhage. EDTA treatment profoundly impaired neutrophil recruitment, suggesting the involvement of a metalloproteinase on venoms...
... Bárbara N. Porto a , Corresponding Author Contact Information , E-mail The Corresponding Auth... more ... Bárbara N. Porto a , Corresponding Author Contact Information , E-mail The Corresponding Author , Caliandra A. Telli b , Tatiana P. Dutra a , Letícia S. Alves a , Marcelo T. Bozza a , Cyntia A. Fin c , Flavia V. Thiesen b and Márcia F. Renner d. ...
Frequency of intentional exposure to organic solvents has been increasing among children and adol... more Frequency of intentional exposure to organic solvents has been increasing among children and adolescents in Brazil. Analysis of benzene, toluene and xylenes (BTX) in human blood is necessary to diagnose the intentional and accidental exposure to these solvents. A method for BTX determination in blood samples by gas chromatography preceded by solid phase microextration (SPME) from headspace (HS) has been described. SPME has several advantages when compared to other extraction techniques such as simplicity, low cost and solvent-free extraction. The method presents good repeatability (precision was of 2.2-8.0%), accuracy from -4.7 to -9.4%, limit of detection <1.0 ug/mL, linearity from 1.0 to 100 ug/mL for toluene and from 5.0 to 100 ug/mL for the other solvents (R2 > 0.99), which shows to be efficient and adequate for the detection of exposure to BTX in blood samples.
Tobacco dependence reaches one‐third of the world population, and is the second leading cause of ... more Tobacco dependence reaches one‐third of the world population, and is the second leading cause of death around the world. Cotinine, a major metabolite of nicotine, is the most appropriate parameter to evaluate tobacco exposure and smoking status due to its higher stability and half‐life when compared to nicotine. The procedure involves liquid–liquid extraction, separation on a RP column (Zorbax® XDB C8), isocratic pump (0.5 mL/min of water–methanol–sodium acetate (0.1 M)–ACN (50:15:25:10, v/v/v/v), 1.0 mL of citric acid (0.034 M) and 5.0 mL of triethylamine for each liter) and HPLC‐UV detection (261 nm). The analytical procedure proved to be sensitive, selective, precise, accurate and linear (r>0.99) in the range of 5–500.0 ng/mL for cotinine. 2‐Phenylimidazole was used as the internal standard. The LOD was 0.18 ng/mL and the LOQ was 5.0 ng/mL. All samples from smoking volunteers were collected simultaneously to establish a comparison between serum, plasma, and urine. The urinary cotinine levels were normalized by the creatinine and urine density. A significant correlation was found (p<0.01) between all matrices. Results indicate that the urine normalization by creatinine or density is unnecessary. This method is considered reliable for determining cotinine in serum and plasma of smokers and in environmental tobacco smoke exposure.
Toxicon : official journal of the International Society on Toxinology, 2007
Snake venom is a complex mixture containing diverse protein components with different structures ... more Snake venom is a complex mixture containing diverse protein components with different structures and functions that are used for prey immobilization and death. Snake venoms from the family Viperidae cause pronounced local and systemic effects, such as pain, edema, hemorrhage and necrosis. Here, we investigated the enzymatic and biological activities of venoms from two Amazonian snakes, Bothriopsis bilineata and Bothriopsis taeniata. Both venoms presented high enzymatic activities for proteases kallikrein, thrombin and plasmin, low levels of trypsin, cathepsin C and leucine aminopeptidase activities, while lacked acetylcholinesterase activity. B. taeniata and B. bilineata crude venoms caused inflammation inducing neutrophil recruitment into peritoneal cavity of mice 4h after injection. Neutrophil recruitment induced by B. taeniata venom was accompanied by hemorrhage. EDTA treatment profoundly impaired neutrophil recruitment, suggesting the involvement of a metalloproteinase on venoms...
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