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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

AVALIAÇÃO DA GENOTOXICIDADE E MUTAGENICIDADE DO BIODENTINE / EVALUATION OF GENOTOXICITY AND MUTAGENICITY OF BIODENTINE

Logar, Gustavo de Almeida 23 May 2014 (has links)
Made available in DSpace on 2016-07-18T17:53:13Z (GMT). No. of bitstreams: 1 Gustavo Logar.pdf: 371330 bytes, checksum: 461b03ba76909955dcf6db3c8b004b60 (MD5) Previous issue date: 2014-05-23 / The Biodentine is a new material suitable for various clinical situations in dentistry. Despite being a promising material, there are few studies evaluating the characteristics of this material, especially its genotoxicity and mutagenicity. Objective: This study aims to evaluate the genotoxic and mutagenic potential of Biodentine "in vivo". Methods: We used 24 Wistar albino rats, males were divided into 3 groups: A - 8 rats where specimens of Biodentine measuring 2 mm in diameter x 10mm length on the dorsum were placed, B - 8 rats, which received cyclophosphamide in single subcutaneous dose (50mg/kg) on the first day of the experiment (positive control group), C - 8 rats where specimens measuring 2 mm in diameter x 10mm long without Biodentine on the dorsum were placed (negative control group). After 24 hours, all animals were euthanized and material from bone marrow of femurs was collected to perform the Comet assay and micronucleus test. Results: Biodentine showed levels of DNA damage (tail intensity %) in bone marrow cells of 23.57 ± 7.70, cyclophosphamide of 27,43 ± 7,40 and negative control of 24.75 ± 5 55 (p < 0.05). The average number of micronuclei in the exposed Biodentine group was 6.25 (standard deviation - SD = 3.53), in the group exposed to cyclophosphamide was 9.75 (SD = 2.49) and negative control group was 0.75 (SD = 1.03) (p < 0.0001). Conclusion: The Biodentine showed an increase in the frequency of micronuclei, but no genotoxicity effect by the Comet assay. / O Biodentine é um novo material indicado para diversas situações clínicas na odontologia. Apesar de ser um material promissor, ainda há poucos trabalhos avaliando as características deste material, em especial sua genotoxicidade e mutagenicidade. Objetivo: Este estudo visa avaliar o potencial genotóxico e mutagênico do Biodentine in vivo . Material e métodos: Foram utilizados 24 ratos Wistar albinos, machos, distribuídos em 3 grupos: A 8 ratos onde foram colocados corpos de prova medindo 2mm de diâmetro x 10mm de comprimento com Biodentine no subcutâneo do dorso; B 8 ratos, que receberam ciclofosfamida em dose única subcutânea (50mg/kg) no primeiro dia do experimento (grupo controle positivo); C 8 ratos onde foram colocados corpos de prova medindo 2mm de diâmetro x 10mm de comprimento sem Biodentine no subcutâneo do dorso (grupo controle negativo). Após 24 horas, todos os animais foram eutanasiados e material da medula óssea dos fêmures foi coletado para realização do Teste do Cometa e do Teste do micronúcleo. Resultados: O Biodentine apresentou níveis de danos no DNA (tail intensity %) em células da medula óssea de 23,57 ± 7,70, a ciclofosfamida de 27,43 ± 7,40 e o controle negativo de 24,75 ± 5,55 (p<0,05). A média de micronúcleos no grupo exposto ao Biodentine foi de 6,25 (desvio padrão DP= 3,53), no grupo exposto a ciclofosfamida foi de 9,75 (DP= 2,49) e no grupo de controle negativo foi 0,75 (DP= 1,03) (p<0,0001). Conclusão: O Biodentine apresentou aumento na frequência de micronúcleos, mas não apresentou efeito genotóxico observado pelo teste do Cometa.
122

Avaliação da Mutagenicidade do Indoxacarbe em Ratos e Gatos / Mutagenicity Assessment of Indoxacarb in Rats and Cats

Silva, Dayane Aparecida Francisco da 16 September 2015 (has links)
Made available in DSpace on 2016-07-18T17:53:15Z (GMT). No. of bitstreams: 1 Dayane.pdf: 321360 bytes, checksum: c2b06ee1c47438b8e086585e5a6fc8c5 (MD5) Previous issue date: 2015-09-16 / Background: Pesticides are substances used for pest control. Because of their persistence in the environment, they can induce toxicity in humans and animals. Indoxacarb is an oxadiazine insecticide that acts against insects of the order Lepidoptera. Furthermore, indoxacarb has demonstrated strong insecticide activity against fleas; therefore, it is used in ectoparasite treatment. Choice of species used in this study (rats and cats) is based on several factors such as these animals have a high count of micronucleated polychromatic erythrocytes, thereby facilitating the execution of the chosen assay; rats are the standard animal model for mutagenicity studies; and the product is intended for use in cats. Limited data in literature pertaining to the mutagenic effects of this product motivated this study. The aim of this study was to evaluate the mutagenicity of indoxacarb when administered in one and tenfold therapeutic doses in rats and cats. This evaluation was performed using the micronucleus test. Materials, Methods & Results: Forty male Wistar rats aged 70 days and weighing 280 ± 10 g and 20 mixed breed male and female adult cats weighing 4 ± 0.2 kg were selected. These animals were obtained from the central animal facility and cattery, respectively, of the university of origin. Rats were reared in individual cages with a controlled temperature of 22°C ± 2°C, humidity of 55% ± 5% and 12-h light dark cycle. Cats were reared in individual stalls with water and food ad libitum. Animals were randomly distributed into four groups comprising 10 rats and 5 cats in respective groups: negative control group, which received 0.9% sodium chloride solution as a single topical administration; positive control group, which received 50 mg/kg cyclophosphamide as a single intra-peritoneal (rats) or intravenous injection (cats); indoxacarb group, which received indoxacarb as a single topical dose according to the manufacturer s recommendations; and high dose indoxacarb group, which also received indoxacarb in a single topical dose, but at a tenfold concentration. Rats were evaluated 24 h after indoxacarb administration. After euthanasia, rat femurs were obtained and their medullary canals were washed using fetal bovine serum. The content was centrifuged and used for smear preparations. Cats were evaluated using the micronucleus test before and 24 h after indoxacarb administration. For smear preparations, a drop of peripheral blood samples was obtained from the tail tip. Smear fixation, staining, and microscopic analysis were similar for cats and rats. Statistical analyses were performed using analysis of variance with contrast through Tukey s method and paired t test to compare time points. The significance level was 5%. Indoxacarb showed no mutagenic activity in the two species and doses evaluated. Even in animals subjected to high doses, the micronuclei count remained within the normal range (p > 0.05). Discussion: The results of this study corroborate those of other studies, where in the mutagenic capacity of indoxacarb was similar in different animal species and product delivery routes. In addition, it is of note the speed and ease of micronucleus testing, which makes it an important mutagenicity bioassay. / Introdução: Os pesticidas são venenos intencionalmente dispersos no ambiente para o controle de pragas e, com sua persistência nesse meio podem induzir a toxicidade em seres humanos e animais. Indoxacarbe é um inseticida, oxidiazínico, que apresenta atividade sobre insetos da ordem lepidóptera. No tratamento contra pulgas em pequenos animais, o indoxacarbe tem demonstrado uma alta atividade inseticida associada a esses ectoparasitas. A escolha da utilização dessas duas espécies animais neste estudo se deu pelo fato de que ratos e gatos apresentam uma grande quantidade de eritrócitos policromáticos micronucleados, facilitando desta forma a realização do ensaio escolhido e, pelo rato ser o modelo biológico padrão para avaliações de mutagenicidade, e por fim pelo fato do produto ser indicado para o uso em gatos. A escassez na literatura sobre o efeito mutagênico causado pelo uso desse produto levou a realização dessa pesquisa, cujo objetivo foi avaliar por meio do teste de micronúcleo a mutagenicidade do indoxacarbe em dose terapêutica e em dez vezes maior em ratos e gatos. Materiais, métodos e resultados: Foram selecionados 40 ratos, com 70 dias de idade, da linhagem Wistar, machos, peso de 280g±10 e 20 gatos adultos, sem raça definida, machos e fêmeas, com peso de 4kg±200gr, ambos do biotério central e gatil da universidade de origem, respectivamente. Os ratos foram mantidos em caixas individuais em ambiente com controle de temperatura 22ºC±2, umidade 55%±5, fotoperíodo 12 horas claro e escuro, os gatos foram mantidos em baias individuais, e ambos com água e ração ad libitum. Os animais foram distribuídos aleatoriamente em quatro grupos, com 10 animais em cada grupo de ratos e 5 animais nos grupos compostos por gatos, e foram tratados com: Grupo controle negativo (GCN)-solução de cloreto de sódio 0,9% por via tópica, em dose única. Grupo controle positivo (GCP)-ciclofosfamida em única dose de 50mg/kg por via intraperitoneal nos ratos e intravenosa nos gatos. Grupo indoxacarbe (GI)- indoxacarbe por via tópica, em dose única recomendado pelo fabricante. Grupo indoxacarbe dose alta (GIDA)-indoxacarbe por via tópica, em dose única, porém dez vezes maior que a dose recomendada pelo fabricante. Os ratos foram avaliados 24 horas após o uso do indoxacarbe, após eutanásia e retirada do fêmur para a realização da lavagem do canal medular com soro fetal bovino, posterior centrifugação, retirada do sobrenadante e realização do esfregaço. Os gatos foram avaliados por meio do teste de micronúcleo antes e 24 horas após a aplicação do indoxacarbe, através da coleta de uma gota de sangue periférico da extremidade do rabo para a realização do esfregaço. A fixação, coloração e leitura das lâminas foram semelhantes para os ratos e gatos. Os testes estatísticos utilizados foram de análise de variância com contraste pelo método de Tukey e, para a comparação entre momentos utilizou-se teste t pareado. O nível de significância adotado foi de 5%. Indoxacarbe não apresentou atividade mutagênica em nenhuma das espécies e doses estudadas, mesmo nos animais submetidos a altas doses, a quantidade de micronúcleos permaneceu dentro da normalidade (p>0,05).Discussão: Os resultados obtidos neste estudo corroboraram com os poucos relatos encontrados na literatura, afirmando a ausência da capacidade mutagênica do indoxacarbe em diferentes espécies animais e vias de administração do produto. Observou-se também a rapidez, e facilidade na realização do teste para micronúcleo, caracterizando-o como um importante bioensaio para avaliações de mutagenicidade.
123

Avaliação auditiva e citogenética de trabalhadores rurais do Pontal do Paranapanema – sp expostos a agroquímicos e tabagismo, isolados ou em combinação / Hearing and citogenetic evaluation of rural workers from Paranapanema Pontal - SP exposed to agrochemicals and tobagism, isolated or combined

TOMIAZZI , Jamile Silveira 27 March 2017 (has links)
Submitted by Adriana Martinez (amartinez@unoeste.br) on 2017-08-03T20:13:27Z No. of bitstreams: 1 Jamile Tomiazzi.pdf: 1140169 bytes, checksum: 85ab1353f7aab9dbdd62efcda0bc0e0c (MD5) / Made available in DSpace on 2017-08-03T20:13:27Z (GMT). No. of bitstreams: 1 Jamile Tomiazzi.pdf: 1140169 bytes, checksum: 85ab1353f7aab9dbdd62efcda0bc0e0c (MD5) Previous issue date: 2017-03-27 / The growing increase in the use of agrochemicals by small and large rural producers has generated environmental impacts and in the health of the exposed population. Another relevant public health problem, whose adverse effects have been widely documented, is smoking. Studies have indicated that isolate exposure to these xenobiotics can lead to ototoxicity and genotoxicity. Thus, the objective of this study was to evaluate the possible auditory and cytogenetic alterations in rural workers exposed to smoking and agrochemicals in isolation or in combination and to identify possible classification patterns of exposure groups. Were evaluated 127 workers of both sexes, with ages ranging from 18 to 39 years, divided into four groups: Control Group - CG; Group exposed to smoking - GT; Group exposed to agrochemicals - GA and Group exposed to the association between smoking and agrochemicals - GTA. Initially, a questionnaire was used to measure the exposure to the study compounds and general and auditory health. Auditory examinations (meatoscopy, conventional and high-frequency audiometry, logoaudiometry and imitanciometry) and cytogenetic evaluation (from cells of the bucal mucosa, stained by Giemsa method) were performed. The data were evaluated by the following pattern recognition algorithms Artificial Neural Network (ANN), Bayes Classifier (BAY) and Support Vector Machine (SVM). The results of the audiological evaluation demonstrated a lowering of high frequency thresholds, a higher incidence of descending type, type A tympanometry and absence of reflex of the stapedic muscle in the three exposed groups (GT, GA and GTA). In addition, these groups showed an increase in the total number of nuclear alterations and in the number of micronuclei, binucleate cells, karyotype, karynx, pycnotic cells and nuclear bud. The computational analysis did not recognize the GTA group as a real value, as with GT and GA in relation to GC, in which the data were distributed with standard and correctly classified. Therefore, it was concluded that exposure to agrochemicals and cigarettes, in isolation or in combination, has been shown to be potentially ototoxic and genotoxic. However, the concomitant use of xenobiotics did not lead to additive or potentiating effect. / O crescente aumento do uso de agroquímicos por pequenos e grandes produtores rurais tem gerado impactos ambientais e à saúde da população exposta. Outro problema relevante de saúde pública, cujos efeitos adversos têm sido amplamente documentados, é o tabagismo. Estudos têm indicado que a exposição isolada a estes xenobióticos pode levar a ototoxicidade e genotoxicidade. Assim, o objetivo deste estudo foi avaliar as possíveis alterações auditivas e citogenéticas de trabalhadores rurais expostos ao tabagismo e aos agroquímicos de maneira isolada ou em combinação e identificar possíveis padrões de classificação dos grupos de exposição. Foram avaliados 127 trabalhadores de ambos os sexos, com faixa etária de 18 a 39 anos, divididos em quatro grupos: Grupo Controle – GC; Grupo exposto ao tabagismo – GT; Grupo exposto a agroquímicos – GA e Grupo exposto à associação entre tabagismo e agroquímicos - GTA. Inicialmente foi aplicado um questionário, para coleta de dados sobre a exposição aos compostos de estudo e saúde geral e auditiva. Em seguida, foram realizados exames auditivos (meatoscopia, audiometria convencional e de alta frequência, logoaudiometria e imitânciometria) e avaliação citogenética (a partir de células da mucosa bucal, coradas pelo método Giemsa). Os dados foram avaliados pelos seguintes algoritmos de reconhecimento de padrões: Artificial Neural Network (ANN), Bayes Classifier (BAY) e Support Vector Machine (SVM). Os resultados da avaliação audiológica demonstraram rebaixamento de limiares auditivos em alta frequência, maior incidência de curva do tipo descendente, timpanometria tipo A e ausência de reflexo do músculo estapédico nos três grupos expostos (GT, GA e GTA). Além disso, nestes grupos foi observado aumento do número total de alterações nucleares e no número de micronúcleos, células binucleadas, cariólise, cariorréxis, células picnóticas e broto nuclear. A análise computacional não reconheceu o grupo GTA como um valor real, como ocorreu com GT e GA em relação ao GC, onde os dados foram distribuídos com padrão e classificadas corretamente. Diante disso, concluiu-se que a exposição a agroquímicos e cigarro, de maneira isolada ou em combinação, demonstrou ser potencialmente ototóxica e genotóxica. No entanto, o uso concomitante dos xenobióticos não levou a efeito aditivo ou de potencialização.
124

Genotoxic effects of oestrogens and nano-NSAIDs: Genotoxic effects of oestrogens in vivo and nano- and bulk forms of NSAIDs on blood samples from prostate cancer patients

Rathore, Dildar S. January 2014 (has links)
The genotoxicological effects of five intra-peritoneal administered oestrogens (17β- oestradiol, daidzein, diethylstilboestrol, genistein, and equol), were examined. Male hooded- Lister rats were used to examine to what extent DNA damage occurred. The alkaline Comet assay was the chosen method used to assess double-strand DNA breakage by examining the Olive tail moment and %age tail DNA. Tissues from the testis, bone marrow, liver and blood were analysed after an 8-day duration of exposure. Statistically significant increases in DNA damage were observed in the testis with daidzein and in the blood with diethylstilboestrol. In addition, a further study was carried out to examine the effects of bulk and nanotised forms of non-steroidal anti-inflammatory drugs (NSAIDs), aspirin and ibuprofen, in the Comet and micronucleus assays, on whole blood taken from prostate cancer patients or volunteers. These were used because it is known that the sensitivity of DNA to genotoxins can be heightened in patients with cancer. Patients’ and volunteers’ blood was cultured with either the bulk or nano-forms for 44 hours at 37°C, 5% CO2. Data were obtained for the Comet assay as above and the number of binucleated cells scored for the micronucelus assay. The results show the nanotised forms of the NSAIDs decreased the levels of strand breakage and lowered the numbers of micronuclei generated compared with their bulk forms. There was no clear difference between the sensitivity of the healthy controls and the prostate cancer patients, with only one individual showing evidence of heightened sensitivity.
125

Genotoxic effects of NSAIDs and hydrocortisone on bulk and nano forms in lymphocytes from patients with haematological cancers

Normington, Charmaine January 2017 (has links)
Chronic inflammation is intimately linked with cancer development and progression and therefore reducing or eliminating inflammation represents a logical treatment and prevention strategy. Studies have shown that anti-inflammatory agents have anti-tumour effects in cancers, with reduced metastases and mortality. Current use of anti-inflammatory agents in the treatment and prevention of cancer is limited by their toxicity and side effects. The emerging field of nanotechnology allows the fundamental properties of a drug to be altered, creating a product with improved reactivity and bioavailability, leading to more targeted treatments and reduced dosage. In the present study, the genotoxic effects of three commonly used anti-inflammatory drugs; aspirin, ibuprofen and hydrocortisone, in their bulk and nano forms were evaluated on peripheral blood lymphocytes of healthy donors using the comet assay and the micronucleus assay. In order to determine any anti-cancer effects, these agents were also tested in peripheral blood lymphocytes in patients with haematological cancers. The glucocorticoid hydrocortisone was also evaluated for anti-oxidant capacity. Our results demonstrate that the nano versions of each drug produced a different response than the bulk counterpart, indicating that a reduction in particle size had an impact on the reactivity of the drug. Our results also indicate that the nano versions of each drug were less genotoxic than the bulk formulation, further emphasising the potential of nanoparticles as an improvement to current treatment options. We also found an anti-oxidant effect with hydrocortisone, with a more profound effect seen with the nano formulation.
126

The effect of oxidative stress in lymphocytes from patients with inflammatory bowel disease and various cancer states compared with healthy control individuals

Najafzadeh, Mojgan January 2010 (has links)
In the present investigation peripheral blood lymphocytes from patients with inflammatory bowel disease (IBD) and different cancer states were treated with various agents and compared with lymphocytes from healthy control individuals (HCI) treated in the same way and measured in the Comet assay. For inflammatory bowel disease, patient's responses in IBD patients treated with H2O2 were higher than in HCI and Crohn's patients (CD) were found to have higher responses than Ulcerative colitis (UC) patients. The responses for all IBD and HCI were all reduced in the presence of chaga mushroom extract which behaved in an antioxidant manner. A second group of IBD patients were treated with the heterocyclic amine (food mutagen), IQ and H2O2 and responses were reduced in the presence of the flavonoids, quercetin and epicatechin and compared with HCI similarity treated. In all cells responses were reduced with flavonoids and again CD had higher responses than the UC patients and IBD patients higher than HCI. The responses with CD and UC were that confirmed in two independent studies with IBD, one with chaga mushroom extract and the other with flavonoids. Peripheral lymphocytes from malignant melanoma and suspected melanoma patients and colon cancer and polyposis patients were compared to the lymphocytes from HCI and treated with UVA. There were differential sensitivities when measured in the micronucleus and Comet assays. The cancer patients had higher responses than those in the precancerous states and they in turn were higher than responses in HCI. In all the studies, untreated baseline DNA damage values were also higher in IBD and cancer patients and pre-cancerous patients than HCIs. This would suggest that baseline frequencies of different diseases compared to controls could be an important biomarker in the diagnosis of pre-cancers and early stage cancers. Also peripheral lymphocytes are a useful surrogate for cancers and pre-cancerous disease states since, blood is present in all organs and tissues and DNA is basically the same in all cells.
127

Effect of nanoparticles on human cells from healthy individuals and patients with respiratory diseases

Osman, Ilham F. January 2010 (has links)
Ever increasing applications of nanomaterials (materials with one or more dimension less than 100 nm) has raised awareness of their potential genotoxicity. They have unique physico-chemical properties and so could have unpredictable effects. Zinc oxide (ZnO) and titanium dioxide (TiO2) are widely used in a number of commercial products. There are published studies indicating that some forms of these compounds may be photo-clastogenic in mammalian cells. What has not been investigated before is the effect of nanoparticles from these compounds in human germ cells. Thus the present study has examined their effects in the presence and absence of UV light in human sperm and compared responses to those obtained with human lymphocytes using the Comet assay to measure DNA damage. The effect of nanoparticles (40-70nm range) was studied in human sperm and lymphocytes in the dark, after pre-irradiation with UV and simultaneous irradiation with UV. The studies do provide some evidence that there are photo-genotoxic events in sperm and lymphocytes in the absence of overt toxicity. The cytotoxic and genotoxic potentials of ZnO and TiO2 as well as their effect on phosphotyrosine expression, were examined in the human epithelial cervical carcinoma cells (Hela cells). This was done to try and determine the underlying molecular events resulting from their exposure to ZnO and TiO2 nanoparticles occurring at the same time as DNA is damaged. Concentration- and time-dependent cytotoxicity, and an increase in DNA and cytogenetic damage with increasing nanoparticle concentrations were reported in this study. Mainly for zinc oxide, genotoxicity was clearly associated with an increase in tyrosine phosphorylation. Nanotechnology has raced ahead of nanotoxicology and little is known of the effects of nanoparticles in human systems, let alone in diseased individuals. Therefore, the effects of TiO2 nanoparticles in peripheral blood lymphocytes from patients with respiratory diseases (lung cancer, chronic obstructive pulmonary disease (COPD) and asthma) were compared with those in healthy individuals using genotoxic endpoints to determine whether there are any differences in sensitivity to nano-chemical insult between the patient and control groups. The results have shown concentration dependent genotoxic effects of TiO2 in both respiratory patient and control groups in the Comet assay and an increasing pattern of cytogenetic damage measured in the micronucleus assay without being statistically significant except when compared with the untreated controls of healthy individuals. Furthermore, modulation of ras p21 expression was investigated. Regardless of TiO2 treatment, only lung cancer and COPD patients expressed measurable ras p21 levels that showed modulation as the result of nanoparticle treatment. Results have suggested that both ZnO and TiO2 nanoparticles can be genotoxic over a range of concentrations without either photoa-ctivation or being cytotoxic.
128

Avaliação do potencial mutagênico e antimutagênico da polpa de açaí (Euterpe olereacea Mart) e do óleo de buriti (Mauritia flexuosa) in vivo / Evaluation of the mutagenic and antimutagenic potential of açai pulp (Euterpe olereacea Mart) and buriti oil (Mauritia flexuosa) in vivo

Ribeiro, Juliana Carvalho 10 January 2011 (has links)
Os corantes são amplamente usados como aditivos na indústria alimentícia. Atualmente, diversas pesquisas têm demonstrado que alguns corantes de origem natural, como por exemplo, polifenóis, antocianinas, carotenóides, dentre outros, são dotados de efeitos benéficos, atuando como promotores da saúde, o que desperta o interesse na produção de alimentos com propriedades funcionais. A polpa de açaí é rica em pigmentos polifenóis e antocianinas, e o óleo de buriti é a maior fonte de - caroteno já identificada em frutos até o momento. No entanto, ainda existem poucos estudos evidenciando os seus efeitos bioativos. O objetivo deste estudo foi avaliar o potencial mutagênico e antimutagênico da polpa de açaí e do óleo de buriti, frente aos danos ao DNA induzidos pelo antitumoral doxorrubicina (DXR), em diferentes tecidos de camundongos Swiss. As metodologias envolvem o teste do micronúcleo em células da medula óssea e em sangue periférico e o ensaio do cometa em células sanguíneas, renais e hepáticas em dois diferentes protocolos de tratamento, sendo um agudo (gavagem e eutanásia após 24 horas) e um sub-agudo (gavagem por 14 dias e eutanásia 24 horas após a última gavagem). Em cada protocolo de tratamento, foram testadas 3 doses diferentes da polpa de açaí (3,33; 10,00 e 16,67g/kg p.c.), usando 8 grupos experimentais (n=6). Seguindo o mesmo delineamento experimental, para cada protocolo de tratamentnoto foram testadas 3 doses do óleo de buriti (100; 200 e 300 mg/Kg p.c.), diluído em óleo de milho, em 10 grupos experimentais (n=6). A DXR (16 mg/kg p.c.; i.p.) foi usada como controle positivo nos testes de antimutagenicidade. Nos ensaios com a polpa de açaí e com o óleo de buriti, em ambos os tratamentos, não houve diferença estatística significativa (p<0,05) entre os grupos tratados apenas com a polpa e o controle negativo, demonstrando ausência de efeitos genotóxicos e mutagênicos. Os tratamentos com as associações de polpa de açaí e DXR mostraram redução significativa (p<0,05) de danos ao DNA induzidos pela DXR em todos os órgão testados, no teste do micronúcleo e no ensaio do cometa, e o tratamento subagudo demonstrou ter sido mais efetivo na inibição da genotoxicidade induzida pela DXR. O óleo de buriti mostrou atividade antimutagênica significativa (p<0,05) em células sanguíneas, no tratamento agudo e no tratamento sub-agudo. No entanto, nota-se que o óleo de milho, usado como solvente nos experimentos com o óleo de buriti interferiu nos resuldados encontrados. A identificação e caracterização de pigmentos naturais polifenóis e antocianinas na polpa de açaí e carotenóides, tocoferóis e compostos fenólicos no óleo de buriti, mencionados na literatura como antimutagênicos e antigenotóxicos, pode justificar os resultados encontrados. Os efeitos antimutagênicos detectados na polpa de açaí e no óleo de buriti encorajam novos estudos, visto que estes podem ter seu uso amplamente explorado na indústria cosmética e farmacêutica, em ações de benefícios à saúde da população e, também na indústria alimentícia, no desenvolvimento de produtos com propriedades funcionais. / The dyes are widely used as additives in the food industry. Currently, several studies have shown that some dyes from natural sources, such as polyphenols, anthocyanins, carotenoids, among others, are endowed with beneficial effects, acting as health promoters, which raises the interest in the production of foods with functional properties. The açai is rich in polyphenols and anthocyanins pigments, and the buriti oil is the largest source of -carotene in fruit that has been identified so far. However, there are few studies showing the bioactive effects. The aim of this study was to evaluate the mutagenic and antimutagenic proprieties of the açai pulp and buriti oil, compared to DNA damage induced by the antitumoral doxorubicin (DXR) in different tissues of Swiss mice. The methods involve the micronucleus test in bone marrow and peripheral blood and the comet assay in blood cells, liver and kidney in two different treatment protocols, an acute (gavage and euthanized after 24 hours) and a sub-acute treatment (gavage for 14 days and euthanized 24 hours after the last gavage).In each treatment protocol, we tested three different doses of açai pulp (3.33, 10.00 and 16.67 g/kg b.w.), using eight experimental groups (n=6). Following the same experimental design for each protocol were tested three doses trataments of buriti oil (100, 200 and 300 mg/kg b.w.), diluted in corn oil, in 10 experimental groups (n = 6). The DXR (16 mg/kg b.w., ip) was used as positive control in the antimutagenicity tests. In tests with the pulp and buriti oil in both treatments, there was no statistically significant difference (p<0.05) between groups treated with pulp and negative control, demonstrating a lack of genotoxic and mutagenic . The treatments with associations of açai pulp and DXR showed a significant reduction (p<0.05) in the DNA damages induced by DXR in all organs tested, in the micronucleus test and comet assay, and subacute treatment showed have been more effective in inhibiting the genotoxicity induced by DXR. Buriti oil showed antimutagenic activity (p<0.05) in blood cells, to treat acute and subacute treatment. However, note that the corn oil used as solvent in experiments with buriti oil resuIts interfere in matches. The identification and characterization of natural pigments, polyphenols and anthocyanins in the açai pulp and carotenoids, tocopherols and phenolic compounds in the buriti oil, mentioned in the literature as antimutagenic and antigenotoxicity, can justify the results. The antimutagenic effects found in açai pulp and buriti oil encourage further studies, since they may have fully explored its use in cosmetic and pharmaceutical industry, in shares of health benefits to the population and also in the food industry in developing of products with functional properties.
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Uso de biomarcadores para avaliar o efeito citogenotóxico e o estresse oxidativo em Trachinotus carolinus (Linnaeus, 1766) ocasionada por nanopartícula de prata / The use of biomarkers to assess genotoxicity and oxidative stress induced by silver nanoparticle in Trachinotus carolinus (Linnaeus, 1766)

Hasue, Fabio Matsu 03 July 2017 (has links)
A ação antimicrobiana da nanopartícula de prata (AgNP) favorece seu uso em diversos produtos. Sua toxicidade está relacionada com o tamanho da nanopartícula, seu estado de agregação e a capacidade em gerar espécies reativas de oxigênio (EsRO). O objetivo deste trabalho foi avaliar os efeitos citogenotóxicos, como também o estresse oxidativo em eritrócitos de Trachinotus carolinus expostos à AgNP. Os peixes receberam, via injeção intraperitoneal, três diferentes doses de suspensão de AgNP, 3, 1.5 e 0.75 &#956;gAgNP/gpeixe. Após 12, 24, 36, 72 e 108 horas o sangue foi coletado para realizar o ensaio cometa e o teste do micronúcleo (MN) outras anormalidades nucleares (ANE), como também o fígado para a atividade enzimática da catalase. A AgNP demonstrou ser citogenotóxica, como também se capaz de promover o estresse oxidativo em Trachinotus carolinus. Os resultados mostram que os danos ao DNA e a ocorrência de MN e ANE apresentaram relação dose-resposta dependente. A redução no dano ao DNA mostrou estar relacionada com o aumento da atividade da catalase. / Silver nanoparticles (AgNP) are applied as antimicrobial agents to many manufactured products. Nanoparticles size, aggregation and its induction of reactive oxygen species (ROS) are associated with AgNP toxicity. This study was undertaken to examine the citogenotoxicity as well as oxidative stress of AgNP in Trachinotus carolinos erythrocytes. The fish received tree different doses of 3, 1.5 e 0.75 µgAgNP/gfish by intraperitoneal injection. Bloods samples were collected and at 12, 24, 36, 72 and 108 hours post-injection to perform the comet assay and the micronucleus test. Extract of liver were used to measure catalase activity. This study showed that AgNP is citogenotoxic to this species and is able to induce oxidative stress. The results showed that the DNA damage, micronucleus and nuclear abnormalities was dose dependent. The reduction of DNA damage exhibit a close relationship with catalase activity.
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Avaliação do potencial mutagênico de corantes têxteis por meio do ensaio de micronúcleo / Evaluation of the mutagenic potential of textile dyes using the micronucleus assay

Cesila, Cibele Aparecida 27 October 2015 (has links)
Os corantes possuem grande importância nos diversos segmentos industriais, sendo utilizados em medicamentos, cosméticos, alimentos, roupas, plásticos, borracha, dentre outros. Atualmente, são produzidos no mundo mais de 7 x 105 toneladas de corantes por ano, sendo que aproximadamente 26.500 toneladas/ano são consumidas no Brasil. A produção desses compostos, apesar de ter grande importância econômica é alvo da preocupação ambiental, pois cerca de 2 a 50% dos corantes utilizados na indústria alcançam o ambiente aquático durante o processo de produção e de processamento têxtil. Desta forma aproximadamente 280.000 toneladas de corantes da indústria têxtil são descarregados nos efluentes industriais a cada ano no mundo. Dentro desse contexto, os estudos envolvendo a avaliação de risco de corantes e seus produtos de degradação são de grande importância para a análise do impacto que esses compostos podem causar à saúde humana e ao ecossistema. O Acid Black 210 é um azo corante frequentemente utilizado no tingimento do couro, algodão e tecido de lã, representando aproximadamente 80 a 90% do corante de cor preta utilizado na indústria. O Disperse Red 73 é um azo corante de cor vermelha, frequentemente utilizado no tingimento de tecidos. No entanto, não existem estudos publicados na literatura científica sobre o potencial genotóxico e toxicológico desses corantes e sobre o monitoramento da presença desses corantes em águas superficiais. Estudos preliminares realizados em nosso laboratório, mostraram que o corante Disperse Red 73 induziu mutagenicidade nas linhagens TA98 e TA100 de Salmonella typhimurium e que foi extremamente tóxico para a espécie de Daphnia similis em ensaios de toxicidade aguda. Desse modo, esse trabalho teve como objetivo avaliar o potencial mutagênico dos corantes Acid Black 210 e Disperse Red 73 através do ensaio de micronúcleo em células HepG2 e avaliar os efeitos ecotoxicológicos agudos do corante Acid Black 210 utilizando os organismos da espécie Daphnia similis. Adicionalmente foram realizados os ensaios de avaliação de proliferação celular, ensaio de avaliação da morte celular por necrose e apoptose e ensaio de parada do ciclo celular utilizando o corante Acid Black 210 em células HepG2. Os resultados obtidos mostraram que o corante Disperse Red 73 não induziu danos cromossômicos em células HepG2 nas condições testadas. O Acid Black 210 não provocou a morte celular por apoptose e/ou necrose, em altas concentrações provocou parada no ciclo celular e induziu a citotoxicidade nos ensaios de proliferação celular. Os ensaios de micronúcleo realizados com o corante Acid Black 210 foram inconclusivos. Portando, os resultados obtidos nesse trabalho mostram que não ha indícios de que o corante Disperse Red 73 induza mutações cromossômicas e sugerem que o corante Acid Black 210 possua baixa toxicidade. No entanto, outros ensaios serão necessários, para que seja realizada uma avaliação de risco ambiental e para os seres humanos. Os resultados obtidos nesse trabalho juntamente com outros resultados do nosso grupo de pesquisa fornecerão subsídios para a realização da avaliação do perigo e caracterização do risco de exposição dos seres vivos a esses corantes. / Dyes and pigments are important compounds in different areas, for example in the medicine, cosmetic, food, clothing, plastic, rubber, and other industries. Currently, the production of these compounds is around 7 x 106 tons per year all over the world, with 26,500 tons per year being consumed in Brazil. The production of dyes, despite its economic relevance, is a subject of environmental concern, because 2 to 50 % of dyes are discharged directly into wastewater during their production process, corresponding to approximately 280,000 t of textile dyes being discharged in the environment worldwide through industrial effluents every year. In this context, the studies of the risk assessment of the dyes and their degradation products are very relevant to assess the impact of these compounds to the human health and the ecosystem. The Acid Black 210 is an azo dye commonly used in the dyeing of leather, cotton, and wool, representing approximately 80 to 90 % of the black dye used in the industry. However, there are not published studies in the scientific literature about the genotoxic potential and the toxicological concerns of this dye, including its monitoring presence in surface waters. Preliminary studies in our laboratory had shown that the Disperse Red 73 dye induces mutagenicity in the TA98 and TA100 Salmonella typhimurium strains and it is extremely toxic to Daphnia similis in acute toxicity tests. Thus, this study aimed to evaluate the mutagenic potential of the dyes Acid Black 210 and Disperse Red 73 through the micronucleus assay in HepG2 cell, and the acute ecotoxicological effects of the dye Acid Black 210 using the Daphnia similis test. Additionally, it was performed cell proliferation tests, the evaluation of the cell death by apoptosis and necrosis, and the cell cycle arrest assay using the Acid Black 210 dye in HepG2 cells. The results obtained in this study showed that the Disperse Red 73 dye did not induce chromosomal damage in HepG2 cells under the conditions tested. Acid Black 210 dye did not cause cell death by apoptosis and/or necrosis, at higher concentrations cause arrest cell cycle and induced cytotoxicity in cell proliferation assays. Micronucleus assays performed with the dye Acid Black 210 showed inconclusive. Therefore, the results of this study show that there is no evidence that the Disperse Red 73 dye induces chromosomal mutations and suggest that the Acid Black 210 dye has low toxicity. However, other tests will be required to do environmental and human risk assessments of these dyes. The results of this study along with other results of our research group will provide these additional requirements.

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