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1.
Talanta ; 274: 126011, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38574537

RESUMO

In this article, we have studied the potential of flexible microtube plasma (FµTP) as ionization source for the liquid chromatography high-resolution mass spectrometry detection of non-easily ionizable pesticides (viz. nonpolar and non-ionizable by acid/basic moieties). Phthalimide-related compounds such as dicofol, dinocap, o-phenylphenol, captan, captafol, folpet and their metabolites were studied. Dielectric barrier discharge ionization (DBDI) was examined using two electrode configurations, including the miniaturized one based on a single high-voltage (HV) electrode and a virtual ground electrode configuration (FµTP), and also the two-ring electrode DBDI configuration. Different ionization pathways were observed to ionize these challenging, non-easily ionizable nonpolar compounds, involving nucleophilic substitutions and proton abstraction, with subtle differences in the spectra obtained compared with APCI. An average sensitivity increase of 5-fold was attained compared with the standard APCI source. In addition, more tolerance with matrix effects was observed in both DBDI sources. The importance of the data reported is not just limited to the sensitivity enhancement compared to APCI, but, more notably, to the ability to effectively ionize nonpolar, late-eluting (in reverse-phase chromatography) non-ionizable compounds. Besides o-phenylphenol ([M - H]-), all the parent species were efficiently ionized through different mechanisms involving bond cleavages through the effect of plasma reagent species or its combination with thermal degradation and subsequent ionization. This tool can be used to figure out overlooked nonpolar compounds in different environmental samples of societal interest through non-target screening (NTS) strategies.


Assuntos
Espectrometria de Massas , Praguicidas , Praguicidas/análise , Praguicidas/química , Praguicidas/sangue , Cromatografia Líquida/métodos , Espectrometria de Massas/métodos , Ftalimidas/química , Ftalimidas/análise , Contaminação de Alimentos/análise , Miniaturização , Captana/análise , Captana/sangue , Captana/química , Análise de Alimentos/métodos
2.
Sci Rep ; 14(1): 1788, 2024 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-38245578

RESUMO

Profenofos (PF) and captan (CT) are among the most utilized organophosphorus insecticides and phthalimide fungicides, respectively. To elucidate the physicochemical and influential toxicokinetic factors, the mechanistic interactions of serum albumin and either PF or CT were carried out in the current study using a series of spectroscopy and computational analyses. Both PF and CT could bind to bovine serum albumin (BSA), a representative serum protein, with moderate binding constants in a range of 103-104 M-1. The bindings of PF and CT did not induce noticeable BSA's structural changes. Both pesticides bound preferentially to the site I pocket of BSA, where the hydrophobic interaction was the main binding mode of PF, and the electrostatic interaction drove the binding of CT. As a result, PF and CT may not only induce direct toxicity by themselves, but also compete with therapeutic drugs and essential substances to sit in the Sudlow site I of serum albumin, which may interfere with the pharmacokinetics and equilibrium of drugs and other substances causing consequent adverse effects.


Assuntos
Captana , Organotiofosfatos , Praguicidas , Ligação Proteica , Espectrometria de Fluorescência , Simulação de Acoplamento Molecular , Albumina Sérica/metabolismo , Soroalbumina Bovina/química , Sítios de Ligação , Termodinâmica , Dicroísmo Circular
3.
Immunity ; 56(7): 1681-1698.e13, 2023 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-37301199

RESUMO

CD4+ T cell responses are exquisitely antigen specific and directed toward peptide epitopes displayed by human leukocyte antigen class II (HLA-II) on antigen-presenting cells. Underrepresentation of diverse alleles in ligand databases and an incomplete understanding of factors affecting antigen presentation in vivo have limited progress in defining principles of peptide immunogenicity. Here, we employed monoallelic immunopeptidomics to identify 358,024 HLA-II binders, with a particular focus on HLA-DQ and HLA-DP. We uncovered peptide-binding patterns across a spectrum of binding affinities and enrichment of structural antigen features. These aspects underpinned the development of context-aware predictor of T cell antigens (CAPTAn), a deep learning model that predicts peptide antigens based on their affinity to HLA-II and full sequence of their source proteins. CAPTAn was instrumental in discovering prevalent T cell epitopes from bacteria in the human microbiome and a pan-variant epitope from SARS-CoV-2. Together CAPTAn and associated datasets present a resource for antigen discovery and the unraveling genetic associations of HLA alleles with immunopathologies.


Assuntos
COVID-19 , Aprendizado Profundo , Humanos , Captana , SARS-CoV-2 , Antígenos HLA , Epitopos de Linfócito T , Peptídeos
4.
Chemosphere ; 313: 137498, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36495984

RESUMO

Apples play an important role in everyone's diet and may contain pesticide residues that can pose a significant health problem for consumers. Various technological processes are promising methods for minimizing pesticide concentrations in fruit. Therefore, the subject of this comprehensive study was to investigate the effects of high-temperature (baking) and low-temperature (freeze-drying) processes on the change in the levels of nine fungicides in apples with skin and peeled. The investigated compounds belong to the chemical groups of benzimidazole (thiophanate methyl and carbendazim), phtalimide (captan and their metabolite tetrahydrophtalimid (THPI)), strobilurin (pyraclostrobin, trifloxystrobin) and triazole (difenoconazole, tebuconazole, tetraconazole). Processing factors (PF) were calculated for each pesticide-process-product combination. The results show that baking and freeze-drying generally reduced pesticide concentrations, with PFs ranging from 0.31 to 0.81 and 0.26 to 0.68, respectively. Apart from freeze-drying for carbendazim and baking for captan, PFs were above 1. Only for thiophanate-methyl, a complete reduction was observed, which resulted from complete degradation to carbendazim. The study also aimed to assess human risk according to the new strategy for different sub-populations with conversion using the 36 PFs obtained. The highest acute exposure (expressed as %ARfD) was obtained for tebuconazole in raw apples (initial concentration of 1.42 mg/kg; 400% ARfD) for Dutch toddlers. After food processing, this decreased to 284% (0.74 mg/kg, baking) and to 137% (0.37 mg/kg, freeze-drying), but was still above the safety limit. Similarly, for adults and the general French population for tebuconazole, the %ARfD was high as it reached the values of 104% (initial concentration of 0.89 mg/kg) in unprocessed apples, 73.9% after baking (0.73 mg/kg) and 35.6% after freeze-drying (0.35 mg/kg). The results indicate that food processing techniques can potentially be used to minimize the hazardous effects of pesticide residues on human health.


Assuntos
Malus , Resíduos de Praguicidas , Praguicidas , Adulto , Humanos , Praguicidas/análise , Malus/química , Resíduos de Praguicidas/análise , Captana/análise , Temperatura , Frutas/química , Ingestão de Alimentos , Medição de Risco , Contaminação de Alimentos/prevenção & controle , Contaminação de Alimentos/análise
5.
Toxicol Appl Pharmacol ; 459: 116340, 2023 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-36509231

RESUMO

Several crops of agronomic interest depend on bees' pollination, and Apis mellifera L (Hymanoptera: Apidae) is the most studied direct pollinator. Nevertheless, the use of pesticides in agricultural environments is common, including fungicides. Studies that seek to evaluate the effects of fungicides on the hypopharyngeal glands of bees, the site of royal jelly synthesis, are lacking. Thus, this work aimed to evaluate the effect of field doses of fungicides (Captan SC® and Zignal®), alone or in mixture, on the hypopharyngeal glands and their subsequent effect on the strength of hives. The evaluations were carried out under field conditions in three hives per treatment. For a period of one month, bee hives received feed containing sugar syrup, pollen and 1.2 mL of Zignal® and 3 mL of Captan SC® in the isolated treatments and 4.2 mL in the mixture. The action of fungicides on the hypopharyngeal glands was determined by transmission electron microscopy analysis in bees 7 and 15 days old, collected in the hives one month after exposure to fungicides. The strength of the hives was evaluated for six months based on the number of frames with adult bees, open and closed brood, and stored food. The results indicate that fungicides promote early degeneration of the rough endoplasmic reticulum and morphological and structural changes in mitochondria. In addition, a reduction in adult population, open and closed breeding and food stock was observed. More pronounced damage occurred when bees were exposed to the mixture of fungicides. Overall, it can be concluded that the presence of fungicides in bee diets promotes harm accentuated over time and compromises the survival of hives. It will be worth estimating the fungicide effects of the queen development and on the colony heath.


Assuntos
Fungicidas Industriais , Himenópteros , Praguicidas , Abelhas , Animais , Fungicidas Industriais/toxicidade , Captana , Agricultura
6.
Food Chem Toxicol ; 163: 112992, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35395341

RESUMO

Exposure to pesticides through eyes, skin, ingestion and inhalation may affects human health by interfering with immune cells, such as macrophages. We evaluated, in vitro, the effect of six pesticides widely used in apple arboriculture on the functions of human monocyte-derived macrophages (hMDMs). hMDMs were cultured for 4 or 24 h with or without pesticides (0.01, 0.1, 1, 10 µmol.L-1). We showed that chlorpyrifos, thiacloprid, thiophanate, boscalid, and captan had little toxic effect at the tested concentrations, while dithianon had low-cytotoxicity at 10 µmol.L-1. While boscalid showed no effect on hMDMs function, thiophanate (0.01 µmol.L-1) stimulated with TPA and thiacloprid (1, 10 µmol.L-1) stimulated with zymosan activated ROS production. Chlorpyrifos, dithianon, and captan inhibited ROS production and TNF-α, IL-1ß pro-inflammatory cytokines. We established that dithianon (0.01-1 µmol.L-1) and captan (0.1, 1 µmol.L-1) induced mRNA expression of NQO1 and HMOX1 antioxidant enzymes. Dithianon also induced the mRNA expression of catalase, superoxide dismutase-2 at 10 µmol.L-1. Together, these results show that exposure to chlorpyrifos, dithianon, and captan induce immunomodulatory effects that may influence the disease fighting properties of monocytes/macrophages while pesticides such as thiacloprid, thiophanate and boscalid have little influence.


Assuntos
Clorpirifos , Macrófagos , Praguicidas , Captana/farmacologia , Clorpirifos/toxicidade , Citocinas/metabolismo , Humanos , Macrófagos/efeitos dos fármacos , Praguicidas/toxicidade , RNA Mensageiro , Espécies Reativas de Oxigênio/metabolismo , Tiofanato/toxicidade
7.
Crit Rev Toxicol ; 50(8): 685-706, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-33146058

RESUMO

Small intestinal (SI) tumors are relatively uncommon outcomes in rodent cancer bioassays, and limited information regarding chemical-induced SI tumorigenesis has been reported in the published literature. Herein, we propose a cytotoxicity-mediated adverse outcome pathway (AOP) for SI tumors by leveraging extensive target species- and site-specific molecular, cellular, and histological mode of action (MOA) research for three reference chemicals, the fungicides captan and folpet and the transition metal hexavalent chromium (Cr(VI)). The gut barrier functions through highly efficient homeostatic regulation of SI epithelial cell sloughing, regenerative proliferation, and repair, which involves the replacement of up to 1011 cells per day. This dynamic turnover in the SI provides a unique local environment for a cytotoxicity mediated AOP/MOA. Upon entering the duodenum, cytotoxicity to the villous epithelium is the molecular initiating event, as indicated by crypt elongation, villous atrophy/blunting, and other morphologic changes. Over time, the regenerative capacity of the gut epithelium to compensate declines as epithelial loss accelerates, especially at higher exposures. The first key event (KE), sustained regenerative crypt proliferation/hyperplasia, requires sufficient durations, likely exceeding 6 or 12 months, due to extensive repair capacity, to create more opportunities for the second KE, spontaneous mutation/transformation, ultimately leading to proximal SI tumors. Per OECD guidance, biological plausibility, essentiality, and empirical support were assessed using modified Bradford Hill considerations. The weight-of-evidence also included a lack of induced mutations in the duodenum after up to 90 days of Cr(VI) or captan exposure. The extensive evidence for this AOP, along with the knowledge that human exposures are orders of magnitude below those associated with KEs in this AOP, supports its use for regulatory applications, including hazard identification and risk assessment.


Assuntos
Captana/toxicidade , Cromo/toxicidade , Fungicidas Industriais/toxicidade , Hiperplasia , Neoplasias Intestinais/induzido quimicamente , Ftalimidas/toxicidade , Rotas de Resultados Adversos , Animais , Duodeno , Humanos , Camundongos , Medição de Risco
8.
J Agric Food Chem ; 68(12): 3729-3741, 2020 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-32125836

RESUMO

To seek new protoporphyrinogen oxidase (PPO) inhibitors with better biological activity, a series of novel diphenyl ether derivatives containing tetrahydrophthalimide were designed based on the principle of substructure splicing and bioisomerization. PPO inhibition experiments exhibited that 6c is the most potential compound, with the half-maximal inhibitory concentration (IC50) value of 0.00667 mg/L, showing 7 times higher activity than Oxyfluorfen (IC50 = 0.0426 mg/L) against maize PPO and similar herbicidal activities to Oxyfluorfen in weeding experiments in greenhouses and field weeding experiments. In view of the inspected bioactivities, the structure-activity relationship (SAR) of this series of compounds was also discussed. Crop selection experiments demonstrate that compound 6c is safe for soybeans, maize, rice, peanuts, and cotton at a dose of 300 g ai/ha. Accumulation analysis experiments showed that the accumulation of 6c in some crops (soybeans, peanuts, and cotton) was significantly lower than Oxyfluorfen. Current work suggests that compound 6c may be developed as a new herbicide candidate in fields.


Assuntos
Herbicidas/química , Herbicidas/toxicidade , Éteres Fenílicos/química , Éteres Fenílicos/toxicidade , Plantas Daninhas/efeitos dos fármacos , Captana/síntese química , Captana/química , Captana/toxicidade , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/fisiologia , Éteres Difenil Halogenados/toxicidade , Herbicidas/síntese química , Simulação de Acoplamento Molecular , Éteres Fenílicos/síntese química , Ftalimidas/síntese química , Ftalimidas/química , Ftalimidas/toxicidade , Plantas Daninhas/enzimologia , Plantas Daninhas/fisiologia , Protoporfirinogênio Oxidase/antagonistas & inibidores
9.
Curr Microbiol ; 77(1): 85-98, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31722045

RESUMO

In the present study five potent rhizobacterial antagonists of Fusarium oxysporum f. sp. ciceris alone and in combination with Mesorhizobium (M) were evaluated for their potential to elicit the defence response reactions to reduce the total loss of plants and enhance the growth of two chickpea cultivars i.e. resistant GPF-2 and susceptible JG-41. Observations revealed that maximum phenolic, peroxidase (PO) and polyphenol oxidase (PPO) activity was induced after 30th day of germination. Maximum phenol concentration of 745.8 and 724.1 µg/gfw root tissues was recorded by Ps45 when co-inoculated with Mesorhizobium in both the varieties i.e. GPF-2 and JG-41 respectively. Isolates Ps45, Ps47 and Ps44 were found most promising to induce PO and PPO activity, in combination with Mesorhizobium and recorded superior over the fungicide with respect to negative control. Similar results were recorded for the phenylalanine ammonia lyase (PAL), maximally induced on 20th day after germination, where dual inoculation of Ps44+M and Ps45+M induced 57.0 and 54.2 nmol of cinnamic acid min-1 gfw-1 in GPF-2. However in case of JG-41, Ps45 and Ba1a exhibited highest PAL activity of 54.2 and 41.4 nmol of cinnamic acid min-1 gfw-1. Malonic aldehyde concentration in stem tissues at 30th day revealed that lipid peroxidation was effectively reduced in rhizobacterial treated plants compared to fungicide and negative control, signifying the role of antagonistic plant growth promoting rhizobacteria in reducing the stress and enhancing the plant's defence response to reduce the disease incidence and thus improving the plant growth and yield. Moreover the dual inoculations were observed superior over the fungicide treatment as well as single inoculations in terms of growth (root/shoot length and weight), signifying the synergistic effect of screened antagonists and native Mesorhizobium in suppressing the pathogen and thereby enhancing the plant growth.


Assuntos
Cicer/metabolismo , Cicer/microbiologia , Fusarium/patogenicidade , Mesorhizobium/fisiologia , Captana/farmacologia , Eletroforese em Gel de Ágar , Fusarium/efeitos dos fármacos , Genótipo , Peroxidação de Lipídeos , Fenilalanina Amônia-Liase/metabolismo
10.
Toxicol Pathol ; 47(7): 851-864, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31558096

RESUMO

Carcinogenesis of the small intestine is rare in humans and rodents. Oral exposure to hexavalent chromium (Cr(VI)) and the fungicides captan and folpet induce intestinal carcinogenesis in mice. Previously (Toxicol Pathol. 330:48-52), we showed that B6C3F1 mice exposed to carcinogenic concentrations of Cr(VI), captan, or folpet for 28 days exhibited similar histopathological responses including villus enterocyte cytotoxicity and regenerative crypt epithelial hyperplasia. Herein, we analyze transcriptomic responses from formalin-fixed, paraffin-embedded duodenal sections from the aforementioned study. TempO-Seq technology and the S1500+ gene set were used to analyze transcription responses. Transcriptional responses were similar between all 3 agents; gene-level comparison identified 126/546 (23%) differentially expressed genes altered in the same direction, with a total of 25 upregulated pathways. These changes were related to cellular metabolism, stress, inflammatory/immune cell response, and cell proliferation, including upregulation in hypoxia inducible factor 1 (HIF-1) and activator protein 1 (AP1) signaling pathways, which have also been shown to be related to intestinal injury and angiogenesis/carcinogenesis. The similar molecular-, cellular-, and tissue-level changes induced by these 3 carcinogens can be informative for the development of an adverse outcome pathway for intestinal cancer.


Assuntos
Captana/toxicidade , Carcinógenos/toxicidade , Cromo/toxicidade , Intestino Delgado/efeitos dos fármacos , Ftalimidas/toxicidade , Animais , Perfilação da Expressão Gênica , Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Intestino Delgado/metabolismo , Intestino Delgado/patologia , Camundongos
11.
Environ Mol Mutagen ; 60(3): 286-297, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30471166

RESUMO

The classification of the fungicide captan (CAS Number: 133-06-2) as a carcinogen agent is presently under discussion. Despite the mutagenic effect detected by the Ames test and carcinogenic properties observed in mice, the genotoxicity of this pesticide in humans is still unclear. New information is needed about its mechanism of action in mammalian cells. Here, we show that Chinese Hamster Ovary (CHO) cells exposed to captan accumulate Fpg-sensitive DNA base alterations. In CHO and HeLa cells, such DNA lesions require the XRCC1-dependent pathway to be repaired. Captan also induces a replicative stress that activated the ATR signaling response and resulted in double-strand breaks and micronuclei. The replicative stress is characterized by a dramatic decrease in DNA synthesis due to a reduced replication fork progression. However, impairment of the XRCC1-related repair process did not amplify the replicative stress, suggesting that the fork progression defect is independent from the presence of base modifications. These results support the involvement of at least two independent pathways in the genotoxic effect of captan that might play a key role in carcinogenesis. Environ. Mol. Mutagen. 60:286-297, 2019. © 2018 Wiley Periodicals, Inc.


Assuntos
Captana/toxicidade , Dano ao DNA/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , Fungicidas Industriais/toxicidade , Mutagênicos/toxicidade , Animais , Células CHO , Carcinogênese/induzido quimicamente , Cricetulus , DNA/biossíntese , Reparo do DNA/genética , Células HeLa , Humanos , Testes de Mutagenicidade , Proteína 1 Complementadora Cruzada de Reparo de Raio-X/metabolismo
12.
Anal Bioanal Chem ; 410(26): 6861-6871, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30105623

RESUMO

Thermally labile pesticides (captafol, captan, dicofol, and folpet) are highly prone to suffer thermal degradation during sample introduction into a gas chromatograph (GC) to tetrahydrophthalimide (THPI), 4,4'-dichlorobenzophenone (DCBP), and phthalimide (PI), respectively, mainly produced in the glass liner of the injector. This undesired behavior leads to inaccurate qualitative and quantitative results. Direct on-column injection (OCI) technique is evaluated as an alternative to avoid or minimize compound alteration during the analysis. This configuration was studied and evaluated for the determination of this group of thermally troublesome pesticides. The OCI inlet was operated in "track oven" temperature and connected to a wide-bore deactivated guard column that is itself connected to a capillary GC analytical column. This technique has demonstrated to be useful for avoiding degradation generated in the hot inlet. Limitations observed for OCI in routine analysis were injection volume, guard column length, and maintenance issues. Analytical standards spiked in vegetable solutions were injected in OCI, not observing any thermal degradation rate. On the contrary, classical splitless injection (SLI) produced high degradation rates in all cases. This OCI approach was validated in citrate QuEChERS extracts of tomato, apple, and orange matrices for these four compounds and their corresponding transformation products (THPI, DCBP, and PI), evaluating recoveries, repeatability, linearity, and matrix effect. This set-up enabled the correct identification and quantitation for most compounds at LOQs of 0.010 mg/kg in fruit and vegetable samples. The OCI grants evident differentiation between metabolites naturally occurring in food and thermal degradation products created during the analysis. Graphical abstract ᅟ.


Assuntos
Cromatografia Gasosa/métodos , Frutas/química , Praguicidas/análise , Verduras/química , Benzofenonas/química , Captana/química , Limite de Detecção , Ftalimidas/química , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem , Temperatura
13.
Pharmacology ; 102(1-2): 81-87, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29953993

RESUMO

BACKGROUND: Estradiol, produced by aromatase (CYP19A1), is very important for reproduction. Folpet, captan, and captafol belong to the phthalimide class of fungicides. They are used to protect the leaves of plants or fruits. They could be endocrine disruptors and may disrupt CYP19A1 activity. METHODS: In the present study, we investigated the effects of folpet, captan, and captafol on estradiol production and human CYP19A1 activity in JEG-3 cells. RESULTS: Folpet, captan, and captafol decreased estradiol production in JEG-3 cells in a concentration-dependent manner. Folpet, captan, and captafol inhibited human CYP19A1 with inhibitory concentration (IC50) values of 3.55, 10.68, and 1.14 µmol/L respectively. These chemicals competitively inhibited human CYP19A1. Molecular docking simulation analysis showed that they tended to bind to the steroid-binding pocket of the CYP19A1. However, the required concentrations may not be relevant to the negligible systemic exposures in humans to these chemicals. CONCLUSION: Folpet, captan, and captafol are potential inhibitors of human CYP19A1.


Assuntos
Aromatase/metabolismo , Captana/análogos & derivados , Captana/farmacologia , Cicloexenos/farmacologia , Ftalimidas/farmacologia , Inibidores da Aromatase/farmacologia , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Disruptores Endócrinos/farmacologia , Estradiol/biossíntese , Humanos , Simulação de Acoplamento Molecular
14.
Pestic Biochem Physiol ; 145: 8-14, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29482735

RESUMO

Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial leaf blight (BLB) and can be effectively controlled by phenazine-1-carboxylic acid (PCA), an antibiotic secreted by Pseudomonas spp. PCA resistance in Xoo was investigated in this research. Only four PCA-resistant strains were obtained by extensive screening, and the resistance was genetically stable in only one of them (P4). P4 was also resistant to phenazine and 1-hydroxyphezine but not to captan, bismerthiazol, or streptomycin. The following were reduced in P4 relative to the parental wild type: growth, virulence, EPS production, extracellular cellulase production and activity, biofilm formation, and swimming ability. ROS accumulation was reduced, resistance to exogenous H2O2 was increased, and expression of catalase genes and catalase activities were increased in P4, suggesting that PCA resistance in P4 results from a reduction in ROS production and/or an increased ability to metabolize ROS following PCA treatment. Given the low risk of Xoo developing PCA resistance and the reduced virulence and fitness of the resistant strain, PCA can be used in alternation with other common bactericides to control BLB in rice fields.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Xanthomonas/efeitos dos fármacos , Biofilmes , Captana/farmacologia , Catalase/genética , Catalase/metabolismo , Celulase/biossíntese , Oryza/microbiologia , Fenazinas/metabolismo , Fenazinas/farmacologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Pseudomonas/metabolismo , RNA Mensageiro/genética , Espécies Reativas de Oxigênio/metabolismo , Estreptomicina/farmacologia , Compostos de Sulfidrila/farmacologia , Tiadiazóis/farmacologia , Nicotiana/efeitos dos fármacos , Virulência , Xanthomonas/isolamento & purificação , Xanthomonas/metabolismo , Xanthomonas/patogenicidade
15.
Toxicol Pathol ; 45(8): 1091-1101, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29161989

RESUMO

High concentrations of hexavalent chromium (Cr(VI)), captan, and folpet induce duodenal tumors in mice. Using standardized tissue collection procedures and diagnostic criteria, we compared the duodenal histopathology in B6C3F1 mice following exposure to these 3 carcinogens to determine whether they share similar histopathological characteristics. B6C3F1 mice ( n = 20 per group) were exposed to 180 ppm Cr(VI) in drinking water, 12,000 ppm captan in feed, or 16,000 ppm folpet in feed for 28 days. After 28 days of exposure, villous enterocyte hypertrophy and mild crypt epithelial hyperplasia were observed in all exposed mice. In a subset of mice allowed to recover for 28 days, duodenal samples were generally indistinguishable from those of unexposed mice. Changes in the villi and lack of observable damage to the crypt compartment suggest that toxicity was mediated in the villi, which is consistent with earlier studies on each chemical. These findings indicate that structurally diverse agents can induce similar (and reversible) phenotypic changes in the duodenum. These intestinal carcinogens likely converge on common pathways involving irritation and wounding of the villi leading to crypt regenerative hyperplasia that, under protracted high-dose exposure scenarios, increases the risk of spontaneous mutation and tumorigenesis.


Assuntos
Captana/toxicidade , Carcinógenos/toxicidade , Cromo/toxicidade , Duodeno/efeitos dos fármacos , Duodeno/patologia , Ftalimidas/toxicidade , Administração Oral , Animais , Relação Dose-Resposta a Droga , Feminino , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/patologia , Camundongos Endogâmicos
16.
Environ Monit Assess ; 189(7): 350, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28646436

RESUMO

The supervised field trials were conducted in a commercial apple orchard in 2016. The trials were an attempt to determine a model for dissipation and toxicological evaluation of fluopyram, tebuconazole, captan, tetrahydrophthalimide (THPI), pirimicarb, spirodiclofen, and boscalid residues detected in fruit of Red Jonaprince, Lobo, and Gala varieties immediately before harvest. The analysis also covered amounts of pesticides still present in remnants of calyx in Lobo and Gala varieties immediately before harvest. Laboratory samples of ripe apples were collected within 14 days of the treatment. Levels of pesticide residues detected in the samples changed at a constant exponential rate, and the residue levels found in ripe apples of Red Jonaprince, Gala, and Lobo varieties immediately before harvest were below maximum residue levels (MRL). Overall, captan residues in remnants of calyx were at a level of 22.3% for the Gala variety and 9.3% for the Lobo variety. Likewise, the long-term daily intake of the detected substances by a Polish adult consumer was low, ranging from 0.02% ADI for pirimicarb to 0.72% ADI for captan.


Assuntos
Benzamidas/análise , Contaminação de Alimentos/estatística & dados numéricos , Malus/química , Resíduos de Praguicidas/análise , Piridinas/análise , Triazóis/análise , Captana , Proteção de Cultivos/métodos , Monitoramento Ambiental , Contaminação de Alimentos/análise , Frutas/química , Humanos , Praguicidas/análise , Ftalimidas , Polônia
17.
Int J Phytoremediation ; 18(11): 1128-35, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27196962

RESUMO

The occurrence of pesticides in groundwater represents an important health issue, notably for population whose drinking water supply source is located in agricultural areas. However, few solutions have been considered with regard to this issue. We tested the efficacy of a vegetal filtering system made of shrub willows planted at a high density (16,000 plants ha(-1)) to filter or degrade pesticides found in the groundwater flowing out of an apple orchard. Ethylene urea (EU), ethylene thiourea (ETU), tetrahydrophthalimide (THPI), atrazine, and desethylatrazine were monitored in the soil solution in willow and control plots over one growing season. ETU and atrazine concentrations were lower in the willow plots relative to the control plots, whereas desethylatrazine concentration was higher in the willow plots. No significant difference was detected for EU and THPI. Furthermore, pesticide concentrations displayed complex temporal patterns. These results suggest that willow filter systems can filter or degrade pesticides, notably ETU and atrazine, and could be used for phytoremediation purposes. Yet, this potential remains to be quantified with further studies using experimental settings allowing more estimation in time and space.


Assuntos
Fungicidas Industriais/metabolismo , Água Subterrânea/análise , Salix/metabolismo , Poluentes do Solo/metabolismo , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental , Captana/metabolismo , Produtos Agrícolas/crescimento & desenvolvimento , Água Potável/análise , Malus/crescimento & desenvolvimento , Maneb/metabolismo , Quebeque , Zineb/metabolismo
18.
Bull Environ Contam Toxicol ; 96(2): 217-23, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26611369

RESUMO

A novel bio-analytical method has been devised based on the change in catalytic activity of acetylcholinesterase (AChE) enzyme induced by captan, carbosulfan, 2,3,7,8-tetrachlorodibenzodioxin (TCDD) and pentachlorophenol (PCP) for the investigation of inhibition efficiency and sensitivity using Pt/ZnO/AChE/Chitosan bioelectrode. The inhibition curves of captan, carbosulfan, TCDD and PCP were similar to Michaelis-Menten curve. TCDD held the minimum inhibitor Michaelis-Menten constant ([Formula: see text]) value (10.2 nM) in comparison with PCP (10.9 nM), carbosulfan (14.5 nM) and captan (7.9 × 10(3) nM). The maximum inhibition of AChE enzyme by captan was about 100 %, which was much higher than that of TCDD (72.7 %), PCP (68.1 %) and carbosulfan (47.7 %). The calculated theoretical sensitivity was in the order of TCDD > PCP > carbosulfan > captan. Comparing with TCDD (35.3 %), PCP (47.8 %) and carbosulfan (20.9 %), only the inhibition efficiency of captan (55.0 %) was the maximum. The developed bioelectrode exhibited high recovery and low relative standard deviation in local tap water samples.


Assuntos
Técnicas Biossensoriais , Captana/análise , Carbamatos/análise , Pentaclorofenol/análise , Resíduos de Praguicidas/análise , Dibenzodioxinas Policloradas/análise , Água/química , Acetilcolinesterase/química , Captana/química , Carbamatos/química , Pentaclorofenol/química , Dibenzodioxinas Policloradas/química
19.
Environ Toxicol Pharmacol ; 39(2): 635-42, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25682009

RESUMO

The repeated use of pesticides, and their subsequent residues, has contributed to severe adverse effects on the environment, including risks to human health. Therefore, it is important to assess the quality of the environment to ensure it remains free from pesticide residues. The six pesticides tested in this study showed high mortality on Eisenia fetida with LC50 values ranging from 7.7 to 37.9 g L(-1). The strongest lethal effect resulted from the organochlorine insecticide endosulfan (LC50=7.7 g L(-1)). Following exposure to the carbamate pesticides, acetylcholinesterase activity in E. fetida decreased dramatically in comparison to the control. Carboxylesterase activity was only lowered in E. fetida exposed to propoxur, when compared to the control. The remaining five pesticides had no significant effect on carboxylesterase activity in E. fetida. In order to discover pesticide-specific biomarkers with differentially expressed proteins after exposure to pesticides, protein patterns of pesticide-treated E. fetida were analyzed using SELDI-TOF MS with Q10 ProteinChips. Protein patterns were compared with their intensities at the same mass-to-charge ratios (m/z). All 42 peaks had intensities with associated p-values less than 0.089, and 40 of these peaks had associated p-values of 0.05. Using SELDI-TOF MS technology, selective biomarkers for the six pesticides tested were found in E. fetida; four proteins with 5425, 5697, 9523, and 9868 m/z were consistently observed in the earthworms following exposure to the carbamates.


Assuntos
Oligoquetos/efeitos dos fármacos , Praguicidas/toxicidade , Acetilcolinesterase/metabolismo , Animais , Biomarcadores/metabolismo , Captana/toxicidade , Carbaril/toxicidade , Carbofurano/toxicidade , Carboxilesterase/metabolismo , Clorpirifos/toxicidade , Endossulfano/toxicidade , Oligoquetos/metabolismo , Propoxur/toxicidade , Análise Serial de Proteínas , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
20.
J Agromedicine ; 17(1): 40-50, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22191502

RESUMO

The objective of this study was to investigate the putative associations of specific pesticides with multiple myeloma. A matched, population-based, case-control study was conducted among men residing in six Canadian provinces (Quebec, Ontario, Manitoba, Saskatchewan, Alberta, and British Columbia). Data were collected on 342 multiple myelome cases and 1506 age and province of residence matched controls. Data were collected by mailed questionnaires to capture demographic characteristics, antecedent medical history, detailed lifetime occupational history, smoking history, family history of cancer, and exposure to broadly characterized pesticides at home, work, and practicing hobbies. Details of pesticide exposures were collected by telephone interview for those who reported 10 hours or more per year of exposure. Exposure to pesticides grouped into major chemical classes resulted in increased risk being detected only for carbamate insecticides [odds ratio (OR) and 95% confidence interval (CI) 1.90 (1.11, 3.27) adjusted for potential confounders]. An exposure to fungicide captan [2.35 (1.03, 5.35)] was positively associated with the incidence of multiple myeloma. While an exposure to carbaryl [1.89 (0.98, 3.67)] was associated with the incidence of multiple myelome with borderline significance. The authors further suggest that certain pesticide exposures may have a role in multiple myeloma etiology, and identify specific factors warranting investigation in other populations.


Assuntos
Mieloma Múltiplo/epidemiologia , Mieloma Múltiplo/etiologia , Praguicidas/efeitos adversos , Adulto , Idoso , Canadá/epidemiologia , Captana/efeitos adversos , Carbamatos/efeitos adversos , Carbaril/efeitos adversos , Estudos de Casos e Controles , Fungicidas Industriais/efeitos adversos , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Exposição Ocupacional , Razão de Chances , Inquéritos e Questionários
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