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1.
J Esthet Restor Dent ; 35(2): 360-367, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-35652434

RESUMO

OBJECTIVE: Few studies evaluated low concentrations of hydrogen peroxide protocols. The aim of this paper was evaluated two application protocols using 4% hydrogen peroxide in at-home bleaching. MATERIALS AND METHODS: Eighty-six patients with upper canines' shade A2 or darker were randomly allocated under two experimental conditions: two daily applications of 1 h each or a 2-h single application. Color change was evaluated using Vita Classical, Vita Bleachedguide, and digital spectrophotometer weekly and 1 month after the bleaching procedure through one-way ANOVA. The risk and intensity of tooth sensitivity (TS) was assessed through visual and numeric rating scale and measured by Fisher's exact test, Mann-Whitney test and one-way ANOVA respectively. RESULTS: After 3 weeks, the mean difference for the ΔSGU Vita Classical (1.0; 95% CI -0.1 to 2.0), ΔEab (0.7; 95% CI -1.4 to 2.8), ΔE00 (0.1; 95% CI -1.4 to 1.6) and Wi (1.8; 95% CI -1.9 to 5.5) presented no difference (p > 0.08). The relative risk for TS was 0.91 (0.72 to 1.14) without significant difference neither in the risk (p = 0.6) nor in the TS intensity for both pain scales (p > 0.65). CONCLUSIONS: The application protocols evaluated (two daily applications of 1 h each or a 2-h single application) for at-home bleaching with 4% hydrogen peroxide did not showed differences in color change and tooth sensitivity. CLINICAL RELEVANCE: Higher amount of active hydrogen peroxide in two daily applications for at-home bleaching neither accelerate bleaching nor increase the risk or intensity of tooth sensibility.


Assuntos
Sensibilidade da Dentina , Clareadores Dentários , Clareamento Dental , Humanos , Peróxido de Hidrogênio , Clareamento Dental/métodos , Resultado do Tratamento , Ensaios Clínicos Controlados Aleatórios como Assunto
2.
J Esthet Restor Dent ; 33(7): 992-998, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34212493

RESUMO

OBJECTIVE: To evaluate the color change stability and patient satisfaction after one-year of at-home bleaching with 10% carbamide peroxide (CP) in trays with or without reservoirs. MATERIALS AND METHODS: Forty-six patients were subjected to bleaching with CP (3 h/daily; 21 days) with a bleaching tray with or without reservoirs. The color was measured one-month and one-year after the completion of bleaching using the spectrophotometer (ΔEab, Δ00 and ΔWi), and shade guide units (ΔSGU). Patients' satisfaction were assessed using a 5-point Likert Scale questionnaire. Data were submitted to paired t-test (α = 0.05). RESULTS: No significant difference between color change after one-month and one-year was observed (VITA Classical shade guide unit and the ΔWi; p > 0.53). Significant differences were observed for the VITA Bleachedguide 3D-MASTER shade guide, ΔEab and ΔE00 (p < 0.03). The level of patient satisfaction was similar between groups (p = 1.00). CONCLUSIONS: Bleaching tray design did not have any influence on the bleaching stability for the 10% CP (Opalescence PF, Ultradent). Patients were very satisfied with the bleaching outcomes regardless of the bleaching tray design. CLINICAL RELEVANCE: Placement of reservoirs in bleaching trays does not increase longevity of dental bleaching. No clinically important color rebound was observed 1 year after bleaching with 10% CP.


Assuntos
Sensibilidade da Dentina , Clareadores Dentários , Clareamento Dental , Seguimentos , Humanos , Peróxido de Hidrogênio , Peróxidos , Resultado do Tratamento , Ureia
3.
Ecotoxicology ; 29(2): 196-202, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31982987

RESUMO

In order to evaluate the differential absorption and toxicity of arsenate (AsV) and arsenite (AsIII), Lemna valdiviana plants were grown in a nutrient solution and subjected to 0.0 (control); 0.5; 1.0; 1.5; 2.0; 3.0; 4.0; 5.0 and 7.5 mg L-1 of AsIII or AsV for three days. Exposure to both chemical forms resulted in As bioaccumulation, although AsIII-grown plants showed higher As content in tissues. In AsV-grown plants, the relative growth rate (RGR) decreased to 50%, at a concentration of 4.0 mg L-1, while for treatments with AsIII, the same decrease was observed at 1.0 mg L-1. The tolerance index decreased with increasing concentrations, with lower values for AsIII. Plants treated with AsIII showed increased superoxide anion levels, whilst higher levels of hydrogen peroxide were present in AsV-treated plants. Moreover, malondialdehyde (MDA) levels were higher for plants subjected to AsIII when compared to AsV at lower concentrations. Concentrations of 1 mg L-1 of AsIII and 4 mg L-1 of AsV showed equivalent MDA levels. Superoxide dismutase and catalase activities were increased at low concentrations and were inhibited at higher concentrations of AsIII and AsV, whereas peroxidase activity was positively modulated by increased AsIII or AsV concentrations. In conclusion, L. valdiviana plants took up and accumulated arsenic as AsIII or AsV, demonstrating the potential for phytoremediation of this metalloid. Furthermore, AsIII-exposed plants showed enhanced toxicity when compared to AsV, at the same applied concentration, although toxicity was more related to internal As concentrations, regardless of the chemical form applied.


Assuntos
Arseniatos/toxicidade , Arsenitos/toxicidade , Poluentes Ambientais/toxicidade , Plantas/efeitos dos fármacos , Araceae/fisiologia , Biodegradação Ambiental , Malondialdeído , Superóxido Dismutase/metabolismo
4.
Genet Mol Biol ; 38(3): 308-15, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26500434

RESUMO

Farm workers are often exposed to pesticides, which are products belonging to a specific chemical group that affects the health of agricultural workers and is mostly recognized as genotoxic and carcinogenic. The exposure of workers from Piauí, Brazil, to these hazardous chemicals was assessed and cytogenetic alterations were evaluated using the buccal micronucleus assay, hematological and lipid parameters, butyrylcholinesterase (BChE) activity and genetic polymorphisms of enzymes involved in the metabolism of pesticides, such as PON1, as well as of the DNA repair system (OGG1, XRCC1 and XRCC4). Two groups of farm workers exposed to different types of pesticides were evaluated and compared to matched non-exposed control groups. A significant increase was observed in the frequencies of micronuclei, kariorrhexis, karyolysis and binucleated cells in the exposed groups (n = 100) compared to controls (n = 100). No differences were detected regarding the hematological parameters, lipid profile and BChE activity. No significant difference was observed either regarding DNA damage or nuclear fragmentation when specific metabolizing and DNA repair genotypes were investigated in the exposed groups.

5.
Ecotoxicol Environ Saf ; 100: 282-6, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24238741

RESUMO

The water eutrophication process by phosphorus and nitrogen allows cyanobacteria blooms which promote, among other effects, the generation and release of the metabolite 2-methylisoborneol (2-MIB) in the environment. This substance has been shown to be recalcitrant to conventional water treatment, degrading water quality. Considering the limited number of studies on the biological effects of 2-MIB in eukaryotic organisms, the present study assessed the genotoxicity of 2-MIB using the in vitro comet assay and cytokinesis block-micronucleus (CBMN-Cytome) assay on Chinese Hamster Ovary (CHO) cells and the in vivo Drosophila melanogaster Somatic Mutation and Recombination Test (SMART). The results showed that 2-MIB (125, 250 and 500 µg/mL) was unable to induce gene and chromosome mutations or events associated with mitotic recombination in the SMART. Similarly, four different concentrations (7.5, 15, 30 and 60 µg/mL) of 2-MIB did not induce increments in frequencies of micronuclei, nuclear buds, and nucleoplasmatic bridges in the CBMN-Cytome assay. In the comet assay, the positive results were restricted to the highest dose, 60 µg/mL of 2-MIB. The results obtained may help evaluate the genotoxic profile of extracellular algal products.


Assuntos
Canfanos/toxicidade , Drosophila melanogaster/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Células CHO , Núcleo Celular/genética , Aberrações Cromossômicas , Ensaio Cometa , Cricetinae , Cricetulus , Cianobactérias/química , Testes para Micronúcleos , Odorantes , Paladar , Água/normas
6.
Genet Mol Biol ; 37(1): 90-104, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24688296

RESUMO

The genotoxicity of bloom head (BHE) and leaf (LE) extracts from artichoke (Cynara scolymus L.), and their ability to modulate the mutagenicity and recombinogenicity of two alkylating agents (ethyl methanesulfonate - EMS and mitomycin C - MMC) and the intercalating agent bleomycin (BLM), were examined using the somatic mutation and recombination test (SMART) in Drosophila melanogaster. Neither the mutagenicity nor the recombinogenicity of BLM or MMC was modified by co- or post-treatment with BHE or LE. In contrast, co-treatment with BHE significantly enhanced the EMS-induced genotoxicity involving mutagenic and/or recombinant events. Co-treatment with LE did not alter the genotoxicity of EMS whereas post-treatment with the highest dose of LE significantly increased this genotoxicity. This enhancement included a synergistic increase restricted to somatic recombination. These results show that artichoke extracts promote homologous recombination in proliferative cells of D. melanogaster.

7.
An Acad Bras Cienc ; 85(2): 585-94, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23828338

RESUMO

Noni, a Hawaiian name for the fruit of Morinda citrifolia L., is a traditional medicinal plant from Polynesia widely used for the treatment of many diseases including arthritis, diabetes, asthma, hypertension and cancer. Here, a commercial noni juice (TNJ) was evaluated for its protective activities against the lesions induced by mitomycin C (MMC) and doxorrubicin (DXR) using the Somatic Mutation and Recombination Test (SMART) in Drosophila melanogaster. Three-day-old larvae, trans-heterozygous for two genetic markers (mwh and flr3 ), were co-treated with TNJ plus MMC or DXR. We have observed a reduction in genotoxic effects of MMC and DXR caused by the juice. TNJ provoked a marked decrease in all kinds of MMC- and DXR-induced mutant spots, mainly due to its antirecombinagenic activity. The TNJ protective effects were concentration-dependent, indicating a dose-response correlation, that can be attributed to a powerful antioxidant and/or free radical scavenger ability of TNJ.


Assuntos
Antimutagênicos/farmacologia , Bebidas , Frutas/química , Morinda/química , Testes de Mutagenicidade/métodos , Animais , Dano ao DNA/efeitos dos fármacos , Drosophila melanogaster/citologia , Drosophila melanogaster/efeitos dos fármacos , Mitomicina/farmacologia , Teofilina/análogos & derivados , Teofilina/farmacologia
8.
Prog Cardiovasc Dis ; 79: 89-99, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37302652

RESUMO

Calcific aortic valve stenosis (CAS), the most prevalent valvular disease worldwide, has been demonstrated to frequently occur in conjunction with coronary artery disease (CAD), the third leading cause of death worldwide. Atherosclerosis has been proven to be the main mechanism involved in CAS and CAD. Evidence also exists that obesity, diabetes, and metabolic syndrome (among others), along with specific genes involved in lipid metabolism, are important risk factors for CAS and CAD, leading to common pathological processes of atherosclerosis in both diseases. Therefore, it has been suggested that CAS could also be used as a marker of CAD. An understanding of the commonalities between the two conditions may improve therapeutic strategies for treating both CAD and CAS. This review explores the common pathogenesis and disparities between CAS and CAD, alongside their etiology. It also discusses clinical implications and provides evidence-based recommendations for the clinical management of both diseases.


Assuntos
Estenose da Valva Aórtica , Aterosclerose , Doença da Artéria Coronariana , Humanos , Doença da Artéria Coronariana/epidemiologia , Doença da Artéria Coronariana/terapia , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/patologia , Estenose da Valva Aórtica/epidemiologia , Estenose da Valva Aórtica/terapia , Aterosclerose/patologia , Fatores de Risco
9.
Mutat Res ; 747(2): 228-33, 2012 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-22640881

RESUMO

The simultaneous treatment with the cross-linking agent cisplatin, the radiomimetic antitumoral drug bleomycin, and the anti-metabolite drug 5-fluorouracil has been used as a regimen to treat patients with squamous cell carcinoma of the head and neck. Considering that these drugs interact directly with DNA, one of the important late-occurring complications from treatment of primary malignancies is the therapy-related secondary cancers as a result of the genotoxic activity of the drugs on normal cells. In this sense, the genotoxicity of this combination was evaluated using the wing somatic mutation and recombination test in Drosophila melanogaster. The mutant spots observed in marker-heterozygous and balancer-heterozygous flies were compared in order to quantitatively and qualitatively estimate the genotoxic effect of these drugs. Cisplatin (0.003 and 0.006mM), bleomycin (0.005 and 0.01mM), and both combinations preferentially induced recombinational events, while mutation is the major event regarding the genetic toxicity of 5-fluorouracil (0.025 and 0.05mM). The combination of these drugs produced synergistic and antagonistic genotoxic effects, depending on the concentrations used, which could impose a higher risk of secondary effects associated with their genotoxic effects, emphasizing the importance of long-term monitoring in patients being treated with these drugs.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/toxicidade , Bleomicina/toxicidade , Cisplatino/toxicidade , Fluoruracila/toxicidade , Mutagênicos/toxicidade , Animais , Cisplatino/antagonistas & inibidores , Dano ao DNA , Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/genética , Testes de Mutagenicidade
10.
Mutat Res ; 742(1-2): 43-7, 2012 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-22142834

RESUMO

Fluoroquinolones are widely used in human and in veterinary medicine due to their broad-spectrum antibacterial activity. They act by inhibiting type II DNA topoisomerases (gyrase and topoisomerase IV). Because of the sequence homology between prokaryotic and eukaryotic topoisomerases II, fluoroquinolones can pose a hazard to eukaryotic cells. However, published information concerning the genotoxic profiles of these drugs in vivo is sparse and inconsistent. We have assessed the activities of three fluoroquinolones, ciprofloxacin, enrofloxacin and norfloxacin, in the Drosophila melanogaster Somatic Mutation and Recombination Test (SMART) and measured their mutagenic and recombinagenic potentials. Norfloxacin was non-genotoxic. Ciprofloxacin and enrofloxacin induced significant increases in spot frequencies in trans-heterozygous flies. To test the roles of somatic recombination and mutation in the observed genotoxicity, balancer-heterozygous flies were also analyzed. Ciprofloxacin and enrofloxacin were preferential inducers of homologous recombination in proliferative cells, an event linked to loss of heterozygosity.


Assuntos
Antibacterianos/toxicidade , Drosophila melanogaster/genética , Fluoroquinolonas/toxicidade , Recombinação Homóloga/efeitos dos fármacos , Mutagênicos/toxicidade , Animais , Testes de Mutagenicidade/métodos
11.
Curr Probl Cardiol ; 47(12): 101342, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35918009

RESUMO

Dyslipidemia, specifically elevated low-density lipoprotein (LDL) cholesterol levels, causes atherosclerotic cardiovascular disease (ASCVD) and increases the risk of myocardial infarction and stroke. Statins, a class of drugs that exert their effects by inhibiting HMG-CoA reductase, a key enzyme in the synthesis of cholesterol, have been the mainstay of therapy for the primary prevention of cardiovascular disease and lipids reduction. Statins are associated with side effects, most commonly myopathy and myalgias, despite their proven efficacy. This review explores non-statin lipid-lowering therapies and examines recent advances and emerging research. Over the previous decades, several lipid-lowering therapies, both as monotherapy and adjuncts to statin therapy and lipid-targeting gene therapy, have emerged, thus redefining how we treat dyslipidemia. These drugs include Bile acids sequestrants, Fibrates, Nicotinic acid, Ezetimibe, Bempedoic acid, Volanesoren, Evinacumab, and the PCSK 9 Inhibitors Evolocumab and Alirocumab. Emerging gene-based therapy includes Small interfering RNAs, Antisense oligonucleotides, Adeno-associated virus vectors, CRISPR/Cas9 based therapeutics, and Non-coding RNA therapy. Of all these therapies, Bempedoic acid works most like statins by working through a similar pathway to decrease cholesterol levels. However, it is not associated with myopathy. Overall, although statins continue to be the gold standard, non-statin therapies are set to play an increasingly important role in managing dyslipidemia.


Assuntos
Anticolesterolemiantes , Doenças Cardiovasculares , Dislipidemias , Inibidores de Hidroximetilglutaril-CoA Redutases , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversos , Anticolesterolemiantes/efeitos adversos , LDL-Colesterol/uso terapêutico , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/prevenção & controle , Ezetimiba/farmacologia , Ezetimiba/uso terapêutico , Dislipidemias/tratamento farmacológico , Colesterol/uso terapêutico
12.
Mutat Res ; 696(2): 139-43, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20083227

RESUMO

Recent studies have added paclitaxel (PAC) to traditional cisplatin (CIS) regimen to treat squamous cell carcinoma of the head and neck. The target of these antineoplastic agents is nuclear DNA for CIS and microtubules for PAC, although it is not restricted to malignant cells. In this study, the genotoxicity of the combined treatment of PAC and CIS was investigated using the standard version of the wing Somatic Mutation and Recombination Test (SMART) in Drosophila melanogaster. Quantitative and qualitative genotoxic effects of these compounds were estimated by comparing wing spot frequencies in marker-heterozygous to balancer-heterozygous flies. Two different concentrations of PAC (0.0025 and 0.005mM) and CIS (0.025 and 0.05mM) as well as combinations of them were employed. The results demonstrated that the spindle poison PAC alone was not genotoxic in this test system, while CIS was able to induce a high incidence of DNA damage in both genotypes, mainly related to somatic recombination. The data obtained for the combined treatments showed that its genotoxicity varied with the concentrations used. In small concentrations the number of total spots induced by combination was reduced in relation to CIS 0.025mM just for marker-heterozygous flies, showing that somatic recombination was the prevalent event involved. At higher concentrations the combined treatment showed significant reductions in the frequencies of large single spots, for both genotypes, and twin spots for marker-heterozygous flies, but did not significantly reduce the total spots frequency in either genotype. The data suggest that aneugenic activity of PAC could be responsible for the reduction in the genotoxicity of CIS.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/toxicidade , Cisplatino/toxicidade , Drosophila melanogaster/efeitos dos fármacos , Paclitaxel/toxicidade , Animais , Cisplatino/administração & dosagem , Dano ao DNA/efeitos dos fármacos , Perda de Heterozigosidade/efeitos dos fármacos , Testes de Mutagenicidade , Mutagênicos , Paclitaxel/administração & dosagem
13.
Integr Environ Assess Manag ; 16(5): 596-607, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32077580

RESUMO

The objective of this study was to evaluate the concentration of potentially toxic elements in Brachiaria decumbens, Stylosanthes guianensis, and Saccharum officinarum plants and soil samples in affected and unaffected areas by rupture of the Fundão dam, Brazil. Samples were collected in areas affected by residues from the Fundão dam (RAA1, RAA2, RAA3) and in an unaffected area (control). The material was analyzed for the composition of micronutrients and trace elements in soil and plants, as well as contamination factor (CF), accumulation factor, and translocation factor (TF). Overall, the results showed that soil and plant tissues had increased Fe, Mn, Cu, and Cr content and decreased Zn content in the affected areas, compared to the control. Leaves and roots of B. decumbens showed an increase in Fe content in affected areas, compared to the control, reaching a mean maximum value of 42 958 µg/g of roots of RAA2-collected plants. As a result, CF for Fe of B. decumbens was classified as very high and they presented low TF values. Furthermore, B. decumbens collected in affected areas showed an increase of Fe, Mn, Cu, and Cr in leaves, stems, and roots, whereas in Stylosanthes guianensis, there was an increase of Fe concentration in all tissues and Cr in leaves. Also, Saccharum officinarum showed the accumulation of Mn in the stem and Cu in leaves and stem. On the other hand, there was no contamination of plants by hazardous elements such as Pb, Cd, and As in the samples analyzed. In conclusion, increases in the content of Fe, Mn, Cu, and Cr were found in soil and several plant tissues of residue-affected areas, which could compromise plant growth and represent potential hazards arising from the biomagnification process in the food chain. Integr Environ Assess Manag 2020;16:596-607. © 2020 SETAC.


O objetivo deste estudo foi avaliar a concentração de elementos potencialmente tóxicos em plantas de Brachiaria decumbens, Stylosanthes guianensis e Saccharum officinarum e amostras de solos em áreas afetadas e não afetadas pelo rompimento da barragem de Fundão. As amostras foram coletadas em áreas afetadas por resíduos da barragem de Fundão (RAA1, RAA2, RAA3) e em uma área não afetada (controle). O material foi analisado quanto à composição de micronutrientes e elementos-traço no solo e plantas, além de fatores de contaminação (CF), bioacumulação e translocação (TF). No geral, os resultados mostraram que o solo e as plantas apresentaram maiores teores de Fe, Mn, Cu e Cr e menores teores de Zn nas áreas afetadas em comparação ao controle. Folhas e raízes de B. decumbens apresentaram aumento no teor de Fe nas áreas afetadas em relação ao controle, atingindo o valor máximo médio de 42.958 µg/g nas raízes de plantas coletadas em RAA2. Como resultado, CF para Fe de B. decumbens foi classificado como muito alto, mas com baixos valores de TF. Além disso, B. decumbens coletadas nas áreas afetadas apresentaram aumento de Fe, Mn, Cu e Cr nas folhas, caules e raízes, enquanto que em Stylosanthes guianensis houve aumento da concentração de Fe em todos as partes das plantas e Cr nas folhas. Saccharum officinarum também apresentou acúmulo de Mn no caule e Cu nas folhas e caule. Por outro lado, não há contaminação das plantas por elementos perigosos como Pb, Cd e As nas amostras analisadas. Concluindo, foram encontrados aumentos nos teores de Fe, Mn, Cu e Cr no solo e em vários tecidos vegetais, o que pode comprometer o crescimento das plantas e representar riscos potenciais decorrentes do processo de biomagnificação na cadeia alimentar. Integr Environ Assess Manag 2020;16:596-607.


Assuntos
Metais Pesados , Plantas , Poluentes do Solo , Brasil , Monitoramento Ambiental , Metais Pesados/análise , Plantas/química , Solo , Poluentes do Solo/análise
14.
Mutagenesis ; 24(2): 169-72, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19047495

RESUMO

This in vivo study investigated the genotoxicity of two dental bonding agents: Adper Single Bond Plus and Prime&Bond 2.1. The somatic mutation and recombination test (SMART) in Drosophila melanogaster was applied to analyse their genotoxicity expressed as homologous mitotic recombination, as well as point and chromosomal mutation. SMART detects the loss of heterozygosity of marker genes expressed phenotypically on the fly's wings. This fruit fly has extensive genetic homology to mammals, which makes it a suitable model organism for genotoxic investigations. Adper Single Bond Plus induced statistically significant increases in the frequency of total spots at the highest concentration tested, while Prime&Bond 2.1 was positive at all concentrations tested. The mechanistic basis underlying the genotoxicity of Adper Single Bond Plus relies on mitotic recombination alone, and was different from that of Prime&Bond 2.1, which showed evidence of the contribution of both recombination and mutational events. These findings indicate that both adhesives are inducers of toxic-genetic events, with the mitotic recombination being the main mechanism of action. The clinical significance of these observations has to be interpreted with data obtained in other bioassays.


Assuntos
Acetona/toxicidade , Bis-Fenol A-Glicidil Metacrilato/toxicidade , Colagem Dentária , Drosophila melanogaster/efeitos dos fármacos , Mutagênicos/toxicidade , Ácidos Polimetacrílicos/toxicidade , Animais , Feminino , Heterozigoto , Larva/efeitos dos fármacos , Masculino
15.
Environ Mol Mutagen ; 49(4): 312-7, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18366095

RESUMO

Antiretroviral therapies based on nucleoside reverse transcriptase inhibitors, like zidovudine (3'-azido-3'-deoxythymidine; AZT) and didanosine (2',3'-dideoxyinosine; ddI), markedly reduce human immunodeficiency virus loads. The Somatic Mutation And Recombination Test in Drosophila melanogaster (wing SMART), in its standard version, was applied to compare AZT and ddI genetic toxicity expressed as point and chromosomal mutation as well as homologous mitotic recombination. The present findings provide evidence that the mechanistic basis underlying the genetic toxicity of these antiretrovirals is mainly related to mitotic recombination. However, a genotoxic pattern can correspondingly be discerned: AZT is able to induce recombination ( approximately 85%) and mutation ( approximately 15%), and ddI causes only homologous recombination (100%) in the wing SMART assay. Another point to be considered is the fact that ddI is 3.8 times less active to induce mutant clones per mg/ml unit as compared to AZT. The clinical significance of these observations has to be interpreted in the light of data obtained from long-term toxicity in patients treated with the above mentioned agents.


Assuntos
Fármacos Anti-HIV/toxicidade , Didanosina/toxicidade , Mutagênicos/toxicidade , Inibidores da Transcriptase Reversa/toxicidade , Asas de Animais/efeitos dos fármacos , Zidovudina/toxicidade , Animais , Drosophila melanogaster/anatomia & histologia , Drosophila melanogaster/genética , Feminino , Masculino , Mitose , Testes de Mutagenicidade , Mutação , Recombinação Genética , Asas de Animais/anormalidades , Asas de Animais/citologia
16.
Toxicol In Vitro ; 22(3): 695-8, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18083001

RESUMO

The present study evaluates the clastogenic and/or aneugenic potential of maté (Ilex paraguariensis) - previously tested for the presence of 48 organophosphorous pesticides - in the culture of human lymphocytes in the absence of exogenous metabolic activation. Peripheral blood was obtained once from three healthy female donors for lymphocyte cell cultures. The cultures were treated with maté infusion (filtered in sterilized sartorius filter with a 0.22 mm pore membrane), distilled water (negative control), and 6 microg/ml bleomycin (positive control). For each experimental person, 3000 binucleated cells (BN) from two independent cultures (1000 cells from replicate cultures) were scored for the presence of micronuclei (MN). No statistical differences between maté infusion concentrations were observed: 1400 microg/ml (0.001+/-0.002), 700 microg/ml (0.0006+/-0.0015), 350 microg/ml (0.002+/-0.002), 175 microg/ml (0.002+/-0.003) and negative control (0.001+/-0.001). The present findings show that there is no clastogenic or/and aneugenic basis underlying maté action in the CBMN assay.


Assuntos
Citocinese/efeitos dos fármacos , Ilex paraguariensis/toxicidade , Linfócitos/efeitos dos fármacos , Mutagênicos , Adulto , Células Cultivadas , Quebra Cromossômica/efeitos dos fármacos , Feminino , Humanos , Testes para Micronúcleos , Testes de Mutagenicidade , Compostos Organofosforados/toxicidade , Folhas de Planta/química , Folhas de Planta/toxicidade
17.
Environ Pollut ; 151(1): 47-52, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17478021

RESUMO

The genotoxicity associated with air pollution in the city of Canoas, Rio Grande do Sul (Brazil), was assessed in November (spring) and January (summer). We applied the somatic mutation and recombination test (SMART) in Drosophila melanogaster in its standard version with normal bioactivation (ST) and in its variant with increased cytochrome P450-dependent biotransformation capacity (HB). The data indicated the genotoxicity of TSP and PM10 collected in November, in both ST and HB crosses. The genotoxic activity of the PM10 material in the spring sample was exclusively associated with the induction of mitotic recombination, whereas the TSP genetic toxicity was due to both recombinational as well as point and/or chromosomal mutation events. Considering PM10 collected in January, a positive response--100% (17.10 m3/ml) concentration--was observed in the HB cross, which was not detected in the ST cross.


Assuntos
Poluentes Atmosféricos/toxicidade , Poluição do Ar/efeitos adversos , Estações do Ano , Poluição do Ar/análise , Animais , Brasil , Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/genética , Genes de Insetos , Testes de Mutagenicidade/métodos , Material Particulado , Recombinação Genética , Asas de Animais/anatomia & histologia
18.
Environ Mol Mutagen ; 48(1): 67-70, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17177210

RESUMO

Vanillin (VA) modulates the genotoxicity of chemical and physical agents in a complex manner. Previous studies indicate that VA inhibits the mutagenicity but increases the mitotic homologous recombination caused by at least some genotoxic agents. In the present study, we have evaluated the effects of VA on the repair of lethal damage produced by three genotoxins, N-ethyl-N-nitrosourea (ENU), ethyl methanesulfonate (EMS), and mitomycin C (MMC), using the DNA repair test (DRT) in Drosophila melanogaster. VA, 0.25% and 0.5% (w/v), increased the toxicity of MMC and EMS in repair-deficient flies, as measured by a decrease in the proportion of male to female progeny in the DRT; sex ratios decreased from 18-48% for MMC and 21-97% for EMS. These effects may be caused by the inhibition of nonhomologous DNA end joining caused by VA. In contrast to the results with MMC and EMS, VA protected against the lethality of ENU in repair-defective flies, as measured by a 43-207% increase in the survival of male flies in the DRT. It was inferred that the protective effect was due to VA modulating stages prior to the induction of ENU lesions in DNA, including modulating the antioxidant properties of VA and/or to its interference with the metabolic activation and/or detoxification of specific genotoxins. The results from this study indicate that the characterization of VA as a promising agent for preventing damage to genes and chromosomes should be tempered by observations that VA can increase the toxicity of chemical agents.


Assuntos
Benzaldeídos/farmacologia , Reparo do DNA/efeitos dos fármacos , Drosophila melanogaster/efeitos dos fármacos , Mutagênicos/toxicidade , Animais , Antimutagênicos/farmacologia , Dano ao DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Drosophila melanogaster/genética , Metanossulfonato de Etila/toxicidade , Etilnitrosoureia/toxicidade , Feminino , Masculino , Mitomicina/toxicidade , Recombinação Genética/efeitos dos fármacos
19.
Environ Mol Mutagen ; 48(8): 644-9, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17879299

RESUMO

Antiseptic mouthwashes used in biofilm control are widely available in the marketplace, despite inconsistent data concerning their genetic and cellular toxicity. In the present study, we investigated the genotoxic potential of three antiseptics currently used for odontologic treatment, Cepacol (containing cetylpyridinium chloride), Periogard (chlorhexidine digluconate), and Plax (triclosan). Genotoxicity was evaluated using the Somatic Mutation and Recombination Test (SMART) in Drosophila melanogaster, employing flies having normal bioactivation (the standard cross) and flies with increased cytochrome P450-dependent biotransformation capacity (the high bioactivation cross). Periogard and Plax produced negative responses in both types of flies; however, Cepacol (75 and 100%) produced positive responses in both the standard and high bioactivation assays, with the genotoxic responses mainly due to the induction of mitotic recombination. Assays performed with ethanol and cetylpirydinium chloride, two major ingredients of Cepacol, indicated that the genotoxicity of the mouthwash is likely to be due to ethanol.


Assuntos
Antissépticos Bucais/toxicidade , Asas de Animais/efeitos dos fármacos , Animais , Drosophila , Testes de Mutagenicidade
20.
Mutat Res ; 607(2): 225-30, 2006 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-16777474

RESUMO

Vanillin (VA), the world's major flavoring compound used in food industry and confectionery products - that has antimutagenic and anticarcinogenic activity against a variety of mutagenic/carcinogenic agents - was tested for the interval between the formation of premutational lesion and it is finalization as a DNA lesion. The overall findings using co-treatment protocols in SMART test suggest that VA can lead to a significant protection against the general genotoxicity of ethylmethanesulphonate (EMS), N-ethyl-N-nitrosourea (ENU), N-methyl-N-nitrosourea (MNU) and bleomycin sulphate (BLEO). Considering MNU, ENU and EMS the desmutagenic activity observed could result from VA-stimulation of detoxification, via induction of glutathione S-transferase. However, the protector effect related to BLEO could be attributed to its powerful scavenger ability, which has the potential to prevent oxidative damage induced by BLEO.


Assuntos
Alquilantes/toxicidade , Antimutagênicos/toxicidade , Benzaldeídos/farmacologia , Mutação/efeitos dos fármacos , Recombinação Genética , Animais , Bleomicina/toxicidade , Cromossomos , Cruzamentos Genéticos , Relação Dose-Resposta a Droga , Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Metanossulfonato de Etila/toxicidade , Etilnitrosoureia/toxicidade , Feminino , Marcadores Genéticos , Masculino , Metilnitrosoureia/toxicidade , Testes de Mutagenicidade
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