Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Bull Environ Contam Toxicol ; 105(5): 685-691, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33067667

RESUMO

Owls are predators that perform important ecological functions. There are several threats to owl conservation such as the bioaccumulation of chemicals through environmental contamination. The high probability of bioaccumulation in these animals is related to their role as predators and high trophic positions. The objective of this study was to quantify four elements (cadmium, chromium, nickel, and lead) as the biomarkers of environmental exposure in owls. To this end, we analyzed pellets and feathers of different owl species. These matrices were contaminated with all four elements, with chromium most commonly detected. Chromium and nickel were found in the pellets in all 10 months of the study, and May was the month with the highest concentrations of all the elements. Tyto furcata appears to bioaccumulate more elements in its feathers than Megascops spp. and Athene cunicularia. Our findings showed bioaccumulation of these four elements in owls and their environment.


Assuntos
Monitoramento Biológico/métodos , Poluição Ambiental/análise , Plumas/química , Conteúdo Gastrointestinal/química , Metais Pesados/análise , Estrigiformes/crescimento & desenvolvimento , Animais , Cádmio/análise , Cromo/análise , Refluxo Laringofaríngeo , Chumbo/análise , Metais Pesados/metabolismo , Níquel/análise
2.
Biology (Basel) ; 9(9)2020 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-32899122

RESUMO

The aim was to evaluate the interactive effects on biochemistry and physiology of soybean plants exposed to simultaneous xenobiotic and water deficit stresses, and the possible attenuation of plant damage by an antioxidant agent. Soybean plants were submitted to eight different soil water potentials, in two experiments (first experiment: -0.96, -0.38, -0.07, -0.02 MPa, and second experiment: -3.09, -1.38, -0.69, -0.14 MPa), xenobiotic, and antioxidant agent applications. Was observed a reduction in water status, gas exchange, photosynthetic pigments, photosystem II quantum yield, and increased leaf temperature in plants under low water availability. Water deficit also induced oxidative stress by the increased production of reactive oxygen species, cellular and molecular damage, and induction of the antioxidant defense metabolism, reduction of gas exchange, water status, and photosynthetic efficiency. The xenobiotic application also caused changes, with deleterious effects more pronounced in low soil water availability, mainly the reactive oxygen species production, consequently the antioxidant activity, and the oxidative damages. This indicates different responses to the combination of stresses. Antioxidant enzyme activity was reduced by the application of the antioxidant agent. Principal Component Analysis showed a relation with the antioxidant agent and reactive oxygen species, which is probably due to signaling function, and with defense antioxidant system, mainly glutathione, represented by thiols.

3.
Environ Toxicol Pharmacol ; 80: 103473, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32860936

RESUMO

Residual contamination of water with MPH represents a severe environmental issue because it can affect non-target animals. Here we describe the behavioral effects in zebrafish after chronic contamination of water containing residues of MPH (0.1875, 1.875 and 3 ug/L). These doses are environmentally relevant since they reflect those found in wastewaters. We evaluated the behavioral effect through the novel tank test (NTT) and social preference test (SPT), and after euthanasia we analyzed oxidative stress parameters. Zebrafish exposed to MPH presented a social impairment, avoiding the conspecifics segment in the social preference test. In addition, MPH in the lowest concentration provoked an anxiolytic effect in the novel tank test. Oxidative stress is not related to these changes. Since the maintenance of an intact behavioral repertoire is crucial for species survival and fitness, our results demonstrate that residual contamination of water by MPH can be a threat to zebrafish, impacting directly to its well-being and survival in the aquatic environment.

4.
Artigo em Inglês | MEDLINE | ID: mdl-32800866

RESUMO

Methylphenidate (MPH) is a psychostimulant widely misused to increase wakefulness by drivers and students. Also, MPH can be found in dietary supplements in a clandestine manner aiming to burst performance of physical exercise practitioners. The abusive use of high doses of caffeine (CAF) in these contexts is equally already known. Here, we demonstrate the behavioral, oxidative and mitochondrial effects after acute exposure to high doses of MPH (80 mg/L) and CAF (150 mg/L), alone or associated (80 mg/L + 150 mg/L, respectively). We used zebrafish as animal model due to its high translational relevance. We evaluated the behavioral effects using the Novel Tank Test (NTT), Social Preference Test (SPT) and Y-maze Task and analyzed biomarkers of oxidative stress and activity of mitochondrial respiratory chain complexes. MPH alone induced antisocial behavior. MPH inhibited lipid peroxidation. The association of MPH + CAF presented memory impairment and anxiogenic behavior. In oxidative status, it inhibited lipid peroxidation, increased protein carbonylation and mitochondrial complex II, III and IV activity. Our results demonstrate that MPH and CAF alone negatively impact the typical behavioral of zebrafish. When associated, changes in cognition, memory, oxidative and mitochondrial status are more relevant.

5.
Adv Pharm Bull ; 9(2): 241-248, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31380249

RESUMO

Purpose: We aimed to evaluate the effect of blueberry extract and microparticles (MP) on sunscreen performance of multifunctional cosmetics. Octocrylene (OCT), benzophenone-3 (BENZ-3) and Tinosorb® M (MBBT) were employed as UV filters. Methods: An in-silico modeling was used to determine the UV filters concentrations to obtain high values of sunscreen protection factor (SPF) and UVA protection factor (UVA-PF). MBBT and blueberry-loaded microparticles (MPMB+B) and MBBT-loaded microparticles (MPMBBT) were prepared by spray-drying. OCT and BENZ-3 were added in the oil phase of cosmetics. Cosmetics A and B contained MPMB+B and MPMBBT, respectively, and cosmetic C was prepared without MP. Characterization, physicochemical stability and in vitro SPF was performed. UV filters distribution in human stratum corneum (SC) for each cosmetic was performed. Anti-oxidant activity of blueberry extract was evaluated. Results: Sunscreen combination with the highest SPF was selected for formulations. Formulations A and B maintained their rheological behavior over time, unlike formulation C. In-vitro SPFs for formulations A, B and C were 51.0, 33.7 and 49.6, respectively. We also developed and validated a method for analysis of the UV filters by HPLC/ PDA suitable for the in-vivo assay. In Tape stripping test, MBBT showed SC distribution similar for all cosmetic formulations. OCT and BENZ-3 distribution to formulation A and C was also similar. Blueberry extract showed antioxidant capacity of 16.71 µg/mL equivalent to vitamin C. Conclusion: Cosmetics containing MPs presented better physical stability. Blueberry increased the photoprotective capacity of the formulations and added extra benefits due to its anti-oxidant and anti-aging properties.

6.
Biomed Chromatogr ; 33(9): e4564, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31041812

RESUMO

Midazolam (MDZ) is the first choice in palliative sedation, and commonly used in sleep induction in anesthesia, with rapid onset of action. However, monitoring of the level of sedation in patients is not accurate. We developed and validated a bioanalytical method to detect MDZ in plasma using high-performance liquid chromatography (HPLC) coupled to a photodiode array detector (PDA) for future monitoring of sedation. MDZ was extracted by solid-phase extraction (SPE). Analyses were performed on a C18 column, using 0.05% triethylamine and acetonitrile as mobile phase, analyzing at 220 nm. Recovery was evaluated by comparing extracted and nonextracted solutions. Precision, accuracy, linearity, limits of detection (LD) and quantification (LQ), specificity and selectivity were determined. The mean recovery obtained by SPE was 101.03%. The method was linear in the range 1.0-50.0 µg/mL. The LD and LQ were, respectively, 0.43 and 1.43 µg/mL. The specificity of the MDZ peak was adequate. The method was able to detect MDZ among other drugs. Plasma anticoagulants showed no interference with the drug detection. The bioanalytical method using HPLC-PDA and SPE was successfully validated and showed linearity, precision, accuracy, specificity and high sensitivity for detection of MDZ in human plasma.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Midazolam/sangue , Extração em Fase Sólida/métodos , Humanos , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes
7.
Aust Endod J ; 45(2): 209-215, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30230647

RESUMO

The aim of this study was to evaluate the influence of ultrasonic activation (US) over final irrigants on antimicrobial activity, smear layer removal and bond strength. The root canals of 180 extracted human teeth were distributed into three experimental tests (n = 60). In each test, the samples were subdivided into six groups (n = 10) according to final irrigation protocols: G1:distilled water (DW); G2:DW + US; G3:17% EDTA; G4:QMix; G5:17% EDTA + US; and G6:QMix + US. The antimicrobial activity was evaluated by counting of colony-forming units (CFUs), the smear layer removal by scanning electron microscopy and the bond strength by push-out test. Statistical analysis was performed for each evaluation (α = 5%). Groups 4 and 6 provided higher bacterial reduction, groups 5 and 6 provided higher smear layer removal, groups 3, 4, 5 and 6 provided the higher bond strength (P < 0.05). US activation did not improve the antimicrobial activity and the bond strength, whereas it improved the smear layer removal.


Assuntos
Anti-Infecciosos , Camada de Esfregaço , Cavidade Pulpar , Ácido Edético , Humanos , Microscopia Eletrônica de Varredura , Irrigantes do Canal Radicular , Ultrassom
8.
Photodiagnosis Photodyn Ther ; 23: 347-352, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30053480

RESUMO

INTRODUCTION: The aim of this study is to evaluate the antimicrobial activity of hypochlorite solutions and reciprocating instrumentation associated with photodynamic therapy (PDT). METHODS: One hundred and thirty two root canals were enlarged up to #35 K-file and inoculated with E.faecalis for 14 days. The 132 samples were randomly divided into eleven groups (n = 12) and subjected to the following protocols: G1-distilled water + Reciproc R40 (control), G2-1% sodium hypochlorite (NaOCl) + Reciproc R40, G3-2.5% NaOCl + Reciproc R40; G4-1% calcium hypochlorite (Ca[OCl]2) + Reciproc R40, G5-2.5% Ca(OCl)2 + Reciproc R40; G6-PDT; G7-distilled water + Reciproc R40 + PDT, G8-1% NaOCl + Reciproc R40 + PDT, G9-2.5% NaOCl + Reciproc R40 + PDT; G10-1% Ca(OCl)2 + Reciproc R40 + PDT, G11-2.5% Ca(OCl)2 + Reciproc R40 + PDT. The percentage bacterial reduction was checked by counting the colony-forming units (CFUs) in 10 samples of each group. The remaining 2 samples of each group were submitted to scanning electronic microscopy (SEM) to illustrate the effectiveness of the proposed treatments. Data were subjected to one-way ANOVA followed by Tukey's post hoc test (α = 0.05). RESULTS: The greatest ability to promote bacterial reduction was observed in groups 8 (1% NaOCl + R40 + PDT), 9 (2.5% NaOCl + R40 + PDT), 10 (1% Ca[OCl]2 + R40 + PDT), and 11 (2.5% Ca[OCl]2 + R40 + PDT), with no significant difference between them (p < 0.05). CONCLUSIONS: The association of PDT with hypochlorite solutions and reciprocating instrumentation provides effective elimination of E.faecalis.


Assuntos
Enterococcus faecalis/efeitos dos fármacos , Ácido Hipocloroso/uso terapêutico , Azul de Metileno/uso terapêutico , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/uso terapêutico , Preparo de Canal Radicular/métodos , Carga Bacteriana , Compostos de Cálcio/uso terapêutico , Terapia Combinada , Cavidade Pulpar/microbiologia , Relação Dose-Resposta a Droga , Humanos , Hipoclorito de Sódio/uso terapêutico
9.
Clin Oral Investig ; 22(2): 859-865, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28669105

RESUMO

OBJECTIVES: Chlorhexidine binds to dentine to provide sustained action. The aim of the present study was to evaluate and compare the substantivity of chlorhexidine using manual, rotary, and reciprocating systems for root canal preparation. METHODS: Forty-five extracted human single-rooted teeth were used for this study. The samples were divided into three groups (n = 15) according to the instrumentation technique used: manual instrumentation (K-File), rotary instrumentation (ProTaper), and reciprocating instrumentation (Reciproc R25). Chlorhexidine gel (2%) was used as auxiliary chemical substance during root canal preparation. Longitudinal grooves were carved on the free surfaces of the roots, providing two halves of each root and resulting in 30 samples per group. Each group was randomly divided into three subgroups (n = 10), and substantivity was evaluated after 48 h, 7 days, and 30 days of incubation. The amount of CHX (in mg/mL) was measured through reverse-phase high-performance liquid chromatography. Statistical analysis was performed by analysis of variance and the Tukey test for post hoc comparisons (α = 0.05). RESULTS: The manual did not show a statistical significant difference with rotary instrumentation (P > 0.05), but higher CHX substantivity was recorded in all periods of observation when compared to reciprocating instrumentation (P < 0.05). CONCLUSIONS: The CHX substantivity on human dentine is lowest when using reciprocating compared to manual and rotary instrumentation. CLINICAL SIGNIFICANCE: Using chemical analysis, this study showed that a manual and rotary multi-instrument system results in greater chlorhexidine substantivity on human dentin than a reciprocating single-instrument system.


Assuntos
Anti-Infecciosos Locais/química , Clorexidina/química , Dentina/efeitos dos fármacos , Preparo de Canal Radicular/métodos , Adulto , Cromatografia Líquida de Alta Pressão , Humanos , Técnicas In Vitro , Distribuição Aleatória , Irrigantes do Canal Radicular/química , Preparo de Canal Radicular/instrumentação
10.
Pharmacogn Mag ; 13(Suppl 2): S370-S374, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28808408

RESUMO

BACKGROUND: The traditional use of Drimys brasiliensis Miers (Winteraceae) in the south of Brazil to reduce cholesterol has not been described in scientific literature. OBJECTIVE: To verify the hypocholesterolemic effects of D. brasiliensis using rats as animal model. MATERIALS AND METHODS: The bark of D. brasiliensis was extracted with water with further lyophilization and was subjected to phytochemical analysis by high-performance liquid chromatography (HPLC), and free radical scavenging activities by 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay to determine antioxidant potential. The hypocholesterolemic activity was determined in male Wistar rats treated with 100 and 250 mg/kg/day extract concomitantly fed a hypercaloric diet, over 20 days (prevention assay). In the treatment assay, rats were fed a hypercaloric diet for 40 days and received the extract (100 mg/kg/day) from day 20. RESULTS: In this research, we found that the extract of the bark of D. brasiliensis was able to reduce the triglycerides significantly and reduce total cholesterol at doses 100 and 250 mg/kg/day and both administration regimens (prevention and treatment) in rats treated with the extract and hypercaloric diet. The extract showed strong antioxidant properties (DPPH assay), probably responsible by hypocholesterolemic activity of the plant. By HPLC, we detected catechin (1.34%), epicatechin (3.48%), rutin (0.86%), caffeic acid (0.45%), and ferulic acid (0.84%) in D. brasiliensis extract. CONCLUSIONS: We confirm the popular use of the plant to reduce of cholesterol. SUMMARY: The extract of the bark of Drimys brasiliensis was able to reduce the triglycerides significantly and reduced total cholesterol at doses 100 and 250 mg/kg/day and both administration regimens (prevention and treatment) in rats treated with the extract and hypercaloric dietThe extract showed strong antioxidant properties (1,1-diphenyl-2-picrylhydrazyl assay), probably responsible by hypocholesterolemic activity of the plantThe extracts present catechin (1.34%), epicatechin (3.48%), rutin (0.86%), caffeic acid (0.45%), and ferulic acid (0.84%)The plant can be used to cholesterol reduction. Abbreviations used: HPLC: High-performance liquid chromatography; PDA: Photodiode array detector; RS: Reference substances; DPPH: 1,1-diphenyl-2-picrylhydrazyl; VCEAC: Vitamin C equivalent antioxidant capacity.

11.
Environ Sci Pollut Res Int ; 24(28): 22673-22678, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28812184

RESUMO

Ozone helps decontamination environments due to its oxidative power, however present toxicity when it is in high concentrations, by long periods of exposition. This study aimed to assess the safety of ozone generator air purifier at concentrations of 0.05 ppm in rats exposed to 3 and 24 h/day for 14 and 28 days. No significant differences are observed between groups in clinical signs, feed and water intake, relative body weight gain and relative weight of organs, macroscopy and microscopy of lungs, and oxidative plasma assay. In this exposure regime, ozone does not cause genotoxicity and no significant changes in pulmonary histology indicative of toxicity. Ozone generated in low concentrations, even in exposure regimes above the recommended is safe, both acute and sub-acute exposition.


Assuntos
Ar Condicionado/normas , Ozônio/análise , Ozônio/toxicidade , Ar Condicionado/instrumentação , Animais , Peso Corporal/efeitos dos fármacos , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/patologia , Ensaio Cometa , Relação Dose-Resposta a Droga , Exposição por Inalação , Pulmão/efeitos dos fármacos , Pulmão/patologia , Masculino , Testes para Micronúcleos , Estresse Oxidativo/efeitos dos fármacos , Ratos Wistar , Testes de Toxicidade Aguda , Testes de Toxicidade Subaguda
12.
Neurosci Lett ; 650: 114-117, 2017 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-28445770

RESUMO

Several studies have reported the presence of methylphenidate (MPH) in effluents; however, its impacts on aquatic life are not yet well understood. Here, we investigated the effects of acute exposure on endocrine and behavioral stress responses to environmentally relevant concentrations of MPH in zebrafish. We show that MPH blunts the response of cortisol to stress in zebrafish. On the other hand, MPH stresses fish per se. Additionally, MPH seems to modulate anxiety-like behaviors. We conclude that the presence of MPH in aquatic environments can alter neuroendocrine and behavior responses, which might considerably impact fish survival and welfare.


Assuntos
Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Hidrocortisona/metabolismo , Metilfenidato/administração & dosagem , Estresse Fisiológico/efeitos dos fármacos , Poluentes Químicos da Água/administração & dosagem , Peixe-Zebra/fisiologia , Animais , Estimulantes do Sistema Nervoso Central/administração & dosagem , Relação Dose-Resposta a Droga , Sistema Endócrino/efeitos dos fármacos , Sistema Endócrino/fisiologia , Feminino , Humanos , Estresse Fisiológico/fisiologia
13.
Food Chem Toxicol ; 100: 247-252, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28017703

RESUMO

Lactose intolerance is characterized by low or inexistent levels of lactase, and the main treatment consists of dietary changes, especially replacing dairy milk by soy milk. Soy contains phytoestrogens, substances with known estrogenic activity, besides, glyphosate-based herbicides are extensively used in soy crops, being frequently a residue in soy beans, bringing to a concern regarding the consumption of soy-based products, especially for children in breastfeeding period with lactose intolerance. This study evaluated the pubertal toxicity of a soy milk rich feeding (supplemented or not with glyphosate, doses of 50 and 100 mg/kg) during prepubertal period in male rats. Endocrine disruption was observed through decrease in testosterone levels, decrease in Sertoli cell number and increase in the percentage of degenerated Sertoli and Leydig cells in animals receiving soy milk supplemented with glyphosate (both doses) and in animals treated only with soy milk. Animals treated with soy milk with glyphosate (both doses) showed decrease spermatids number and increase of epididymal tail mass compared to control, and decrease in the diameter of seminiferous tubules compared to soy milk control group. Animals receiving soy milk supplemented with 100 mg/kg glyphosate showed decrease in round spermatids and increase in abnormal sperm morphology, compared to control.


Assuntos
Disruptores Endócrinos/toxicidade , Sistema Endócrino/efeitos dos fármacos , Glicina/análogos & derivados , Puberdade/efeitos dos fármacos , Leite de Soja/farmacologia , Animais , Glicina/toxicidade , Herbicidas/toxicidade , Células Intersticiais do Testículo/citologia , Células Intersticiais do Testículo/efeitos dos fármacos , Masculino , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Wistar , Células de Sertoli/citologia , Células de Sertoli/efeitos dos fármacos , Leite de Soja/química , Espermatozoides/efeitos dos fármacos , Testosterona/sangue
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA