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Navegando por Orientadores "BAHIA, Marcelo de Oliveira"

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    Avaliação do efeito antigenotóxico e anticitotóxico do bioproduto método CANOVA®
    (Universidade Federal do Pará, 2012-09-28) NASCIMENTO, Henrique Fonseca Sousa do; BAHIA, Marcelo de Oliveira; http://lattes.cnpq.br/3219037174956649
    The CANOVA® (CA) method is a Brazilian homeopathic immunomodulator. CA is indicated in clinical conditions where the immune system is impaired. N-Methyl-Nnitrosourea (NMU) is an N-nitroso carcinogenic alkylating agent used as an experimental model in rodents and monkeys. NMU also shows genotoxic/mutagenic effects that can be assessed by classical tests such as detection of DNA damage and chromosomal aberrations. Although several studies have shown promising results in the use of CA, there are no studies reporting possible antigenotoxic effects of this medicine, despite its anticancer potential. Therefore, the present study evaluated the in vitro antigenotoxic and anticytotoxic effects of CA in human lymphocytes exposed to NMU. Samples of human lymphocytes that were subjected to different concentrations of a mixture containing CA and NMU were used in the present study. The viability of cells exposed to NMU was evaluated by MTT assay, CA genotoxicity/antigenotoxicity was evaluated by the comet assay and CA anticytotoxicity was assessed by quantification of apoptosis and necrosis using fluorescent dyes (acridine orange/ethidium bromide). The MTT assay showed that NMU was able to decrease lymphocyte viability significantly. By using the comet assay it was observed that CA significantly reduces DNA damage induced by NMU, which sets a clear antigenotoxic effect of the homeopathic compound. CA also reduced significantly the frequency of NMU-induced apoptosis after 24 hours of treatment. We conclude that CA had an antigenotoxic and anticytotoxic effect in the conditions evaluated in this study, thereby demonstrating a clear cytoprotective potential.
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    Avaliação do efeito citoprotetor do composto homeopático canova® em linhagem celular de rim de macaco verde africano (VERO) exposta ao fármaco dipirona sódica
    (Universidade Federal do Pará, 2018-03-01) BONFIM, Laís Teixeira; BAHIA, Marcelo de Oliveira; http://lattes.cnpq.br/3219037174956649
    Paracetamol, sodium dipyrone and ibuprofen are among the main medicines exempt from medical prescription available in pharmacies in Brazil. Sodium dipyrone is highlighted in the literature as one of the most commonly used drugs. Despite its wide use, our research group demonstrated that sodium dipyrone exerts genotoxic and cytotoxic effects. Therefore, studies with medicines that may provide protection or that ameliorate the possible damages caused by sodium dipyrone are very important. The homeopathic compound Canova® (CA) seems to be a good candidate for such purpose, since in combination with other drugs it seems to soften the side effects of such drugs. Therefore, the present work aims to evaluate the possible cytoprotective effect of CA on African green monkey kidney cell line (VERO) exposed to the drug sodium dipyrone using the comet, micronucleus, apoptosis and immunocytochemistry assays. Results obtained by the comet test showed that sodium dipyrone induces an increase in DNA damage index of the VERO line. However, when such cells were co-treated with CA at the three concentrations studied, a significant reduction in the ID was observed, indicating a possible antigenotoxic effect of CA. We observed in the apoptosis and necrosis assays that dipyrone induced an increase in the percentage of apoptosis in both 24 hours and 48 hours. However when the drug was associated with CA, a significant reduction in this effect was observed in the three concentrations of CA + dipyrone. Results on immunocytochemistry showed an increase in the expression of caspase 8 and cytochrome C when cells were exposed to dipyrone. On the other hand, co-treatment significantly reduced such effect. Expression of caspase 9 was also observed after dipyrone tratament, however, co-treatment did not reduce such effect. Therefore, in our experimental conditions CA acted as a cytoprotect agent against the damages induced by dipyrone.
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    Avaliação do potencial citotóxico e genotóxico do piroxicam em linhagem VERO
    (Universidade Federal do Pará, 2016-08-08) MOYSÉS, Daniele de Araújo; BAHIA, Marcelo de Oliveira; http://lattes.cnpq.br/3219037174956649
    The Piroxicam is a NSAID that pharmacologically belongs to oxicam class and is indicated to treat various ailments such as rheumatoid arthritis, primary dysmenorrhea, endometriosis, among others. Its anti-inflammatory properties are well known and is related to its non-selective ability to reversible inhibition of COX, but it is known little about their cytotoxic activity and its effect on DNA. There are few data on the possible genotoxic effects of Piroxicam in mammalian cells. These effects can be monitored for the prevention and control of some adverse reactions and major side effects. This study was designed to investigate the possible genotoxic and cytotoxic induced in vitro by Piroxicam drug in kidney line of African green monkey (VERO). The viability of cells exposed to piroxicam was evaluated by MTT assay, cytotoxicity of piroxicam was verified by quantifying apoptosis and necrosis using fluorescent dyes (Hoechst, propidium iodide and fluorescein diacetate) and genotoxicity of piroxicam was evaluated by the comet assay. The results of the cell viability assay showed that Piroxicam reduces significantly (p <0.05) cell viability in the concentrations of 1.0 mM, 2.0 mM, 4.0 mM and 8.0 mM. It is also noted that piroxicam induced significant killing (p <0.01) by apoptosis in all concentrations tested, both as to 24h treatment 48h. In the case of the comet assay, there was no damage to the DNA in any concentration tested. The data support the idea that piroxicam has a cytotoxic activity, but has no genotoxic potential in the tested conditions.
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    Avaliação in vitro dos efeitos citotóxicos e genotóxicos do antifúgico Fluconazol em linhagens de rim de macaco verde (VERO)
    (Universidade Federal do Pará, 2018-11-26) CORREA, Regianne Maciel dos Santos; BAHIA, Marcelo de Oliveira; http://lattes.cnpq.br/3219037174956649
    Fluconazole is a broad-spectrum triazole antifungal that is well-established as the first-line treatment for Candida albicans infections. Despite its extensive use, reports on its genotoxic/mutagenic effects are controversial; therefore, further studies are needed to better clarify such effects. African green monkey kidney (Vero) cell line were exposed in vitro to different concentrations of Fluconazole and were then evaluated for different parameters, such as cytotoxicity (MTT/cell death by fluorescent dyes), genotoxicity/mutagenicity (comet assay/micronucleus test), and induction of oxidative stress (DCFH-DA assay). Fluconazole was used at concentrations of 81.6, 163.2, 326.5, 653, 1306, and 2612.1μM for the MTT assay and 81.6, 326.5, and 1306μM for the remaining assays. MTT results showed that cell viability reduced upon exposure to Fluconazole concentration of 1306μM (85.93%), being statistically significant (P<0.05) at Fluconazole concentration of 2612.1μM (35.25%), as compared with the control (100%). Fluconazole also induced necrosis (P<0.05) in Vero cell line when cells were exposed to all concentrations (81.6, 326.5, and 1306μM) for both tested harvest times (24 and 48 h) as compared with the negative control. Regarding genotoxicity/mutagenicity, results showed Fluconazole to increase significantly (P<0.05) DNA damage index, as assessed by comet assay, at 1306μM versus the negative control (DI=1.17 vs DI=0.28, respectively). Micronucleus frequency also increased until reaching statistical significance (P<0.05) at 1306μM Fluconazole (with 42MN/1000 binucleated cells) as compared to the negative control (13MN/1000 binucleated cells). Finally, significant formation of reactive oxygen species (P<0.05) was observed at 1306μM Fluconazole vs the negative control (OD=40.9 vs OD=32.3, respectively). Our experiments showed that Fluconazole is cytotoxic and genotoxic in the assessed conditions. It is likely that such effects may be due to the oxidative properties of Fluconazole and/or the presence of FMO (flavin-containing monooxygenase) in Vero cells.
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    Avaliação in vitro dos efeitos genotóxicos e citotóxicos do fármaco dipirona sódica (Metamizol Sodium) em linhagem de rim de macaco verde africano (VERO)
    (Universidade Federal do Pará, 2016-10-27) GOMES, Lorena Monteiro; BAHIA, Marcelo de Oliveira; http://lattes.cnpq.br/3219037174956649
    The dipyrone or metamizole belongs to the family of the pyrazolones. It is one of the nonsteroidal anti-inflammatory compounds (NSAIs) most used, Brazil included, mainly due to its low financial cost. However, in some countries the sale of dipyrone is prohibited due to reported severe cases of agranulocytosis as a result of its use. Despite its high usage, studies showing genotoxic and cytotoxic effects of dipyrone in mammalian cells are scarce. Therefore, in the present study we will assess cell viability, genotoxic effects, cytotoxic effects (by apoptosis and necrosis induction) and the induction of reactive oxygen species (ROS) in VERO cells (a cell line obtained from red kidney of green monkey) exposed to dipyrone. Our results showed a significant reduction in viability of cells exposed to dipyrone by the MTT assay. A significant increase in damage index evaluated by comet assay was also observed, which indicate its genotoxic effects. In which concerns the cytotoxic effects of dipyrone, we observed a significant increase in the number of apoptotic cells using fluorescent dyes after 24h and 48 h of treatment with the drug. Ours results also showed that there was no significant difference in the induction of ROS generation after treatment of the cells with the drug assessed by the DCFH-DA technique. Thus, our work showed that dipyrone is both a genotoxic and cytotoxic drug to VERO cells in the assessed conditions.
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    Avaliação in vitro dos possíveis efeitos citotóxicos e genotóxicos do alcalóide julocrotina em linfócitos humanos
    (Universidade Federal do Pará, 2011-11-04) CORREA, Regianne Maciel dos Santos; BAHIA, Marcelo de Oliveira; http://lattes.cnpq.br/3219037174956649
    Leishmaniasis is considered a public health problem, mainly due to the presence of different species of enzootic Leishmania, involving many different hosts and insect vectors. The pentavalent antimony remain the first choice drugs for the treatment of leishmaniasis for more than 50 years, however, its use has been compromised due mainly to the parasite developed resistance to the drug. Thus, the choice of drugs derived from plants based on the study and use of traditional medicine practices should appear as a new strategy for the control of leishmaniasis. However, it is important to note that some of these drugs can be toxic to the body and may even have genotoxic properties, causing changes in DNA with consequent increased risk of carcinogenesis. Julocrotine (2 -[N-(2-methylbutanolyl)]-N-phenylethylglutarimide) is an alkaloid isolated from the species Croton pullei var. glabrior Lanj. (Euphorbiaceae), widely found in the Amazon jungle and known to possess potent leishmanicidal effect. Thus, the present study evaluated the cytotoxic and genotoxic effects of julocrotina using the MTT and the Comet Assays in cultured human lymphocytes. Our results showed that the alkaloid did not show cytotoxicity in human lymphocytes at the concentrations tested. However, julocrotine showed to be genotoxic to human lymphocytes treated with the highest concentration (632μM) of the substance. Although the cytotoxicity results seem promising with respect to the use of julocrotina in the treatment of leishmaniasis, the genotoxic effect observed reinforces the need to obtain the necessary cautions for its use as an herbal leishmanicidal.
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    Caracterização in vitro dos efeitos genotóxicos e citotóxicos da droga antimalárica artesunato em linfócitos humanos
    (Universidade Federal do Pará, 2015-10-23) MOTA, Tatiane Cristina; BAHIA, Marcelo de Oliveira; http://lattes.cnpq.br/3219037174956649
    Malaria is one of the most serious infectious disease in the world, with quite extensive geographic distribution in tropical areas. Its treatment is based on administration of specific drugs, as artemisinin and its derivatives: artesunate, which will be the subject of this study, and artemether. The artesunate is a semi-synthetic compound derived from artemisinin, a substance extracted from the Chinese plant Artemisia annua L. Despite the widespread use of artesunate in antimalarial therapy and the strong evidences that other antimalarials such as partenin and chloroquine present genotoxic effects in vitro; there are few studies that demonstrate artesunate genotoxic effects in human lymphocytes. In previous studies carried out in laboratory human cytogenetics, it was shown that artesunate induces cytotoxic and genotoxic effects in human lymphocytes in vitro. Despite these findings, the mechanisms of these effects have not been adequately characterized due to limitations of the techniques used. This study aimed to assess in vitro the cytotoxic and genotoxic effects of artesunate on human peripheral blood lymphocytes using assays such as FISHMN, oxidative stress and immunocytochemistry by immunofluorescence. We aimed through these tools elucidate the mechanisms responsible for the effects of artesunate in DNA of human lymphocytes. The results found in this study suggest that the artesunate induces the formation of ROS and other free radicals and that these substances are causing DNA damage in human lymphocytes in culture. Thus cells with damaged DNA, not being able to reverse this condition, activate apoptosis through the extrinsic and intrinsic pathways.
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    Ecologia alimentar de Saimiri macrodon (Elliot, 1907) (Primates: Cebidae) em floresta de várzea na Amazônia Central
    (Universidade Federal do Pará, 2016-04-20) LAUTON, Denise Costa Rebouças; BAHIA, Marcelo de Oliveira; http://lattes.cnpq.br/3377799793942627
    The availability of fruits in the Amazon floodplain forests is seasonal what demand from frugivorous adaptive strategies to ensure their survival in periods of fruit scarcity. In this scenario we evaluated the diet, activity patterns and the use of space by Saimiri macrodon during periods of higher (aquatic phase) and lower (terrestrial phase) fruit availability in the várzea forest of Mamirauá Sustainable Development Reserve, Brazil. Social units were followed and the behavior of the animals was recorded through scan sampling method within two minutes between eight-minute intervals. Saimiri macrodon presented faunivorous-frugivorous diet, and arthropods were important in the diet during both ecosystem phases (59.5% of the records; N = 899), despite the highest consumption during the terrestrial phase (t = 3.40, df = 41; p = 0.001). In the aquatic phase, S. macrodon consumed an average of 29 fruits more than in the terrestrial phase. Fruits of Ficus species were the most consumed in both phases, demonstrating the relevance of this genus to S. macrodon, especially during the period of greater fruit scarcity. The general activity budget followed the common pattern of squirrel monkeys, with the predominance of travelling (56%) and feeding (23%), and the rest of the records distributed among social interactions (6%) resting (< 1,0%) and others (7,5%). Among the activities, social interactions, resting and food were the only ones that showed a significant difference between the phases, having been both more frequent during the aquatic phase, in which fruit availability is higher. In both phases, S. macrodon occupied the low várzea more often and fed mainly on medium (55.8%) and high (35.8%) forest vertical strata. The results are similar to other studies on squirrel monkeys, which indicate typical genus behavior patterns though, S. macrodon, different of the expected, has used mostly the medium and high strata of the canopy.
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    Efeito do metilmercúrio em girinos e recém-metamorfoseados de Physalaemos ephippifer (Steindachner, 1864) (Anura, Leptodactylidae)
    (Universidade Federal do Pará, 2016-11-23) CASTELO BRANCO, Ailin; BAHIA, Verônica Regina Lobato de Oliveira; http://lattes.cnpq.br/1218901740124657; BAHIA, Marcelo de Oliveira; http://lattes.cnpq.br/3219037174956649
    The metal contamination in amphibians has been taken into account as one of the factors contributing to the population decline of these animals. The mercury (Hg) is an environmental contaminant showing high levels of toxicity. Its organic form, methylmercury (MeHg), may bioaccumulative reaching high levels in the trophic chain. For amphibian populations, bioaccumulation of metals is important once that such animals may be MeHg diffusers from the aquatic environment to the terrestrial environment because of their double life cycle. MeHg concentrations in high doses can cause obvious lethargic effects and larvae mortality of amphibious, however little is known about subchronic effects of MeHg doses. Therefore, the present research aims to explore the effects of subchronic exposure to MeHg in one experimental model, the species Physalaemus ephippifer, describing, identifying and characterizing the possible changes in physical performance of larvae and newly metamorphosed, in addition to teratogenic and morphological changes in the sensory and nervous system. After the toxicological test, with MeHg concentrations of 0.007 μg/ml, 0.004 μg/ml 0.0007 μg/ml and 0.0004 μg / ml and negative control, the animals were assessed by behavioral analysis simulating breakout predatory, morphometric and analysis in light microscopy and scanning electron microscopy. Our results revealed that MeHg concentrations did not induce locomotor weaknesses in tadpoles and nor apparent anatomical morphological damage, however, it induces the appearance of a massive cell count of pyknotic nuclei in the areas of the cerebellum and optic tectum. Such alteration, which remains in the animal even after metamorphosis, induces a locomotor weakness in concentration of 0,007μg/ml which is also the concentration where one increased teratogenic damage effect (corneal malformation) is observed. Therefore, we conclude that MeHg is a neurotoxic and teratogenic agent for P. ephippifer and that such features lead to one decrease in locomotor performance. The present work may contribute to the knowledge on effect of MeHg in amphibian populations that live in environments where this contaminant is present as member of the ecosystem.
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    Investigação do efeito terapêutico do Psyllium sobre a dislipidemia infanto-juvenil
    (Universidade Federal do Pará, 2011-12-12) RIBAS, Simone Augusta; SILVA, Luiz Carlos Santana da; http://lattes.cnpq.br/6161491684526382; BAHIA, Marcelo de Oliveira; http://lattes.cnpq.br/3219037174956649
    Psyllium is one of the richest known sources of soluble mucilaginous dietary fibre, and is considered to be a useful supplement to dietary therapy for the treatment of patients with hypercholesterolemia. The aim of this study was to assess the efficacy and safety of psyllium as a dietary supplement for the reduction of the lipidic profile of dyslipidemic Brazilian children and adolescents. Fifty-five subjects (6-19y) with mild to moderate hypercholesterolemia were evaluated in a randomised, double-blind, placebo-controlled, parallel clinical trial, conducted in two periods. During the initial dietary adaptation phase, all subjects enrolled were treated with diet low in saturated fat (<7%) and cholesterol (<200mg/day) for 6-week to prior to the treatment phase. After this period, all eligible participants were allocated randomly to two groups (control n=25 and psyllium n=30) using a computer-generated random number sequence. Over an eight-week clinical trial period, one group (psyllium) were maintained a diet low in saturated fat and cholesterol supplemented daily with 7.0g of psyllium, while the control group received the same diet plus with an equivalent amount of cellulose (placebo). At the end of the treatment period, four subjects were excluded following randomisation (lost to follow up) leaving 51 subjects (control group n= 24; psyllium group n=27, who completed the study. At the end of experiment, the psyllium group presented a significant decrease in the concentrations of total cholesterol, TC (4.1% [-0.20 mmol/L]; p=0.01) and LDL-cholesterol, LDL-c (7.2% [-0.24 mmol/L]; p<0,001). Additional reductions were observed in comparison with the control group (TC: 4.1% [-0.20 mmol/L]; p=0.007) and LDL-c: 7.8% [-0.26 mmol/L]; p=0.002). None of the participants reported any aversion to the smell, taste, appearance or texture of the psyllium, and absence serious adverse effects. Psyllium therapy shows significant efficacy on lowering of the LDL-c. It also demonstrates to be safe and acceptable for pediatric population in the study.
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    Perfil citopatológico de pacientes atendidas na Casa da Mulher e avaliação da atividade do ácido caurenoico contra linhagens de câncer cervical
    (Universidade Federal do Pará, 2018-02-28) ROCHA, Silvia Maria Machado da; ROCHA, Carlos Alberto Machado da; http://lattes.cnpq.br/5789536737681588; BAHIA, Marcelo de Oliveira; http://lattes.cnpq.br/3219037174956649
    Cervical cancer (CC), which is of great importance for public health, is considered to be the 4th most common type of cancer in the world. Human papillomavirus (HPV) infections are the main risk factor. Approximately 70% of women with CC are in less developed regions, demonstrating a socioeconomic relationship. Papillomavirus belong to the family Papillomaviridae, with more than 40 genera, of which five are composed of HPVs, with at least 200 species already described associated with human infections. These virus are enveloped, spherical and have a double-stranded DNA genome. HPVs have tropism by epithelial cells and persistent infections can lead to progressive intraepithelial transformations with evolution to precursor lesions of cervical cancer, and finally cancer. HPV infection is the most common sexually transmitted infection in the world, and most sexually active people, men and women, will have contact with the virus at some point in their lives. In the present study, the cytopathological profile of patients treated at a Secondary Reference Unit in Gynecological Cancer of the city of Belém / PA and the activity of caurenoic acid against cervical cancer lines were analyzed. The profile of the microbiological and cytopathological findings was verified in the examinations carried out by the Casa da Mulher laboratory during a period of one year, using data from 2,202 cervical cancer preventive exams (PCCU), showing a weak correlation between age range and frequency of microbiological findings and pathological alterations. The microbiological findings were the presence of three species: Gardnerella vaginalis (23.48%), Candida sp. (12.44%) and Trichomonas vaginalis (0.68%). The prevalence of cytologic abnormalities corresponded to 5.72%. Atypia cells of undetermined significance corresponded to 2.679%, and the total proportion of potentially malignant neoplastic lesions was 1.09%. The increase in PCCU coverage in the female population needs to be achieved and health promotion must be effected through intersectoral partnerships, popular participation, and collective accountability for quality of life. On the other hand, the evaluation of the genotoxic and mutagenic effect of caurenoic acid (CA) in cervical cancer lines was performed using HeLa (HPV18-positive), CaSki (HPV16-positive) and C33A (HPV-negative). AC showed a strong positive correlation with the genotoxicity indicators evaluated. At high concentrations, it inhibited the expression of E6 and E7 HPV genes, which interfere with cell cycle regulation. Although genotoxic effects were observed, the assays pointed to the possibility of using CA as feedstock for therapeutic agents against cervical cancer with HPV, as well as future research on E6 and E7 functions.
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