Influ��ncia da fixa����o e de m��todos de secagem na detec����o de altera����es proliferativas ultraestruturais induzidas pelo Diuron no urot��lio vesical de ratos wistar

P��s-gradua����o em Patologia - FMB

Avalia����o dos efeitos delet��rios do diuron e de seus metab��litos em lambaris (Astyanax sp.): testes de toxicidade, marcadores de estresse oxidativo, marcadores genot��xicos e enzimas de biotransforma����o

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Diuron metabolites and urothelial cytotoxicity: In vivo, in vitro and molecular approaches

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Diuron-induced rat urinary bladder carcinogenesis: Mode of action and human relevance evaluations using the International Programme on Chemical Safety framework

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Valida����o de metodologias de extra����o e quantifica����o de pesticidas, diuron, clorpirif��s e metil paration em ��guas subterr��neas em regi��o de cultura de soja, utilizando QuEChERS/HPLC-UV

P��s-gradua����o em Qu��mica - IQ

Determination of carbofuran and diuron in FIA system using electrochemical sensor modified with organometallic complexes and graphene oxide

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Dose and temporal effects on gene expression profiles of urothelial cells from rats exposed to diuron

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Estudo da toxicidade de diferentes doses do Diuron (3-(3,4 -dichlorophenyl)-1,1-dimethylurea) no epit��lio da bexiga de ratos wistas machos por microscopia eletr��nica de varredura

Diuron (3-(3,4-Dichlorophenyl)-1,1-dimethylurea) is a substituted urea herbicide widely used on agricultural crops such as soy, cotton and sugar cane. In a previous long-term study this herbicide exerted carcinogenic activity on the urinary bladder and renal pelvis mucosa of Wistar rats and breast of mice. Also, it was shown to be carcinogenic to the mice skin in a initiation-promotion assay. In 1997, the northamerican EPA evaluated Diuron as a ���known/likely��� carcinogen for humans (USEPA, 2004). In a previous study developed at this laboratory, male Wistar rats treated with Diuron 2500 ppm during 20 weeks presented increased indices of cell proliferation and incidences of simple urothelial hyperplasia (HS) in the urinary bladder. Under scanning electron microscopy (SEM) severe urothelial necrosis and hyperplasia were observed. However, in that study the urinary bladders of animals exposed to lower doses of Diuron were not examined under SEM. Therefore, the possible dose-response influence of Diuron on the urothelium under SEM is not known. The present study aimed to analyze under SEM the urinary bladder of male Wistar rats exposed to 125 ppm, 500 ppm and 2500 ppm doses of Diuron through diet during 20 weeks and to compare to the previous histological findings in the same material. Under SEM, 125 ppm and 2500 ppm groups presented significantly (p<0,05) increased incidences of simple hyperplasia, i.e., 7/10 and 8/10 respectively, compared to control group and the 500 ppm group The sensitivity of SEM was higher since it detected a 45% incidence of hyperplasiaswhile the histological analysis found only 27%. Considering SEM as the gold-standard, histology showed a 44% sensitivity, 86.4% specificity, a positive predictive value of 72,7% and negative predictive value of 65,5% and accuracy of 67,5%. Scanning Electron Microscopy...(Complete abstract click electronic access below)

Express��o do gene Glipican 3 (Gpc3) no urot��lio da bexiga de ratos expostos ao diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) por 7 dias e 20 semanas

Diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) is a substituted urea herbicide widely used in crops of sugar cane, cotton and soybeans. In 1997, this agent has been classified by the United States Environmental Protection Agency as known/likely human carcinogen because it induced tumors in the urinary bladder and renal pelvis of rats, and breast and skin of mice exposed to 2500 ppm for feed for two years. A previous study from our group demonstrated dose-response relationship in the gene expression profile associated with severe necrosis on bladder urothelium and increased incidence of simple hyperplasia in male Wistar rats treated with different concentrations of diuron for 20 weeks. To check how early the molecular changes occurs, rats were fed for 7 days with diets containing diuron at 0, 125, 500 or 2500 ppm. The main observations recorded were urothelium ultrastructural alterations and disruptions of molecular pathways associated with cell-cell interaction and the tissue organization maintenance. Particularly, the gene Glypican 3 (Gpc3), a surface proteoglycan related to cellular adhesion and apoptosis induction, was down regulated on urothelium exposed to 2500ppm diuron for 7 days and 20 weeks. The aim of this study was validate by quantitative RT-PCR real time, the reduced Gpc3 gene expression in epithelial cells of the urinary bladder of male Wistar rats treated with different concentrations of diuron for 7 days and 20 weeks. The endogenous control of the quantitative PCR real time technique was the ��-actin gene and the target was the gene Gpc3. The relative quantification (RQ) was obtained by the method of relative quantification 2-����Ct . Animals exposed to diuron for 7 days or for 20 weeks presented reduction of Gpc3 gene expression compared to the control group. This reduction was statistically significant only for the 7 days study. Moreover, by comparing animals exposed for 7 days with the exposed for 20 weeks, it was ...

A new biomimetic sensor based on molecularly imprinted polymers for highly sensitive and selective determination of hexazinone herbicide

A new selective sensor based on molecularly imprinted polymers (MIPs) was developed for the determination of hexazinone (HXZ) in environmental samples. MIPs were synthesized using a non-covalent approach, and selection of the monomers employed in the polymerization reaction was carried out by molecular modeling. Three functional monomers with high (2-vinylpyridine (MP17)) and intermediate (methacrylic acid (MP12) and acrylamide (MP5)) energies of binding to the template (HXZ) were selected for preparation of the MIPs, in order to conduct comparative studies and validate the theoretical data. For sensor construction, carbon pastes were modified with each MIP or NIP (non-imprinted polymer), and HXZ determination was performed using differential pulse adsorptive cathodic stripping voltammetry (DPAdCSV). All parameters affecting the sensor response were optimized. In HCl at pH 2.5, the sensor prepared with MP17 (5% w/w in the paste) showed a dynamic linear range between 1.9 �� 10���11 and 1.1 �� 10���10 mol L���1, and a detection limit of 2.6 �� 10���12 mol L���1, under the following conditions: accumulation time of 200 s at a potential of ���0.5V, scan rate of 50 mVs���1, pulse amplitude of 60 mV, and pulse width of 50 ms. The sensor was selective in the presence of other similar compounds, and was successfully applied to the analysis of HXZ in river water samples.

Desenvolvimento de sensores eletroqu��micos e m��todos de extra����o em fase s��lida baseados em sistemas biomim��ticos para an��lise de poluentes ambientais

P��s-gradua����o em Qu��mica - IQ

Estudo do potencial de degrada����o do herbicida diuron e seus metab��litos por bact��rias isoladas de solo de canavial

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Degrada����o do herbicida diuron por bact��rias isoladas de solos de cultura de cana-de-a����car e avalia����o da toxidade dos metabolitos gerados sobre peixes

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Avalia����o do potencial de degrada����o do herbicida diuron por fungos isolados de solo de canavial e suas toler��ncias aos metab��litos gerados

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Evaluation of early changes induced by diuron in the rat urinary bladder using different processing methods for scanning electron microscopy

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)