Teses em Neurociências e Biologia Celular (Doutorado) - PPGNBC/ICB

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/2390

O Doutorado Acadêmico pertence ao Programa de Pós-Graduação em Neurociências e Biologia Celular (PPGNBC) do Instituto de Ciências Biológicas (ICB) da Universidade Federal do Pará (UFPA).

Navegar

Agora exibindo 1 - 20 de 128

Acesso aberto (Open Access)
Caracterização de aspectos morfológicos e ultra-estruturais do ciclo de vida de microsporidios encontrados em peixes da Região Amazônica
(Universidade Federal do Pará, 2007-03-28) MATOS, Edilson Rodrigues; NASCIMENTO, José Luiz Martins do; AZEVEDO, Carlos José Correia de; http://lattes.cnpq.br/7216249286784978; http://lattes.cnpq.br/3066639837918744
This work describes the results in the light (LM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) obtained of the life cycle of some microsporidian species (phylum Microsporidia Balbiani, 1882) parasites of the ichthyofauna of the Amazon region. Emphasis special to the ultrastructural aspects of the different life cycle phases with evidence of the spores was given. The spores and life cycle stages characterized the different genus and species. The ultrastructural organization of the host tissues with the lysed aspects, that frequently occurred, and the ultrastructural aspects of the xenoma, was discussed.
Acesso aberto (Open Access)
Efeitos da expansão de volume extracelular sobre o conteúdo de catecolaminas e a ativação neuronal de estruturas do hipotálamo e do tronco cerebral de ratos
(Universidade Federal do Pará, 2007-07-24) OLIVEIRA, Fabíola Raquel Tenório; DINIZ, Domingos Luiz Wanderley Picanço; http://lattes.cnpq.br/9601463988942971; RODRIGUES, José Antunes; http://lattes.cnpq.br/4243976484500835
The fine adjustment of the volume and osmolarity of body fluids is vital to survival. Any variation in the composition of the internal environment, active behavioral mechanisms, neural and hormonal compensatory which control intake and excretion of water and electrolytes in order to maintain homeostasis hydroelectrolytic. Changes in the range of 1-2% in blood osmolarity stimulate the release of arginine vasopressin (AVP) resulting in antidiuresis addition to oxytocin (OT) and atrial natriuretic peptide (ANP) promoting natriuresis. Work done in our laboratory using the experimental model of extracellular volume expansion (EVEC) showed activation of magnocellular OT-neurons located in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) responsible for the secretion of AVP and OT also changed in response this stimulus. The involvement of the sympathetic nervous system in these conditions has been raised. Projections spinal and brainstem (sympathetic) to the hypothalamus could act selectively inhibiting signals for eating and stimulating signals for excretion of water and electrolytes. The role of noradrenergic brainstem this regulation still needs to be better established. Thus, this study aimed to elucidate the role of the sympathetic nervous system (noradrenergic pathway) in the regulation of the changes induced model of EVEC analyzing by high performance liquid chromatography the content of norepinephrine (NE), epinephrine (DA) and serotonin (5 -HT) in brainstem structures such as the nucleus of the solitary tract (NTS), bulb rostral ventrolateral (RVLM), locus coeruleus (LC) and dorsal raphe nucleus (DRN) and hypothalamic structures like SON and PVN. We also seek, by immunocytochemical studies to determine changes in the pattern of neuronal activation by analysis of Fos-HT or Fos-5HT in the above mentioned structures in experimental conditions in which are induced changes in extracellular fluid volume.
Acesso aberto (Open Access)
Neurodegeneração crônica em modelo murino: ensaios comportamentais e neuropatológicos na doença prion em fêmeas adultas de camundongos albinos suíços
(Universidade Federal do Pará, 2009-04-30) OLIVEIRA, Roseane Borner de; DINIZ, Cristovam Wanderley Picanço; http://lattes.cnpq.br/2014918752636286
In the present report we described behavioral and neuropathological changes induced by ME7 prion agent inoculated into CA1 of the albino Swiss mice and confirmed previous descriptions in the murine model of prion disease C57Bl6J with two exceptions: 1) septal region present higher level of microglial activation and reactive astrocytosis 2) disease progression (from inoculation to death) is 4 weeks longer and on average, early behavioral changes start correspondently 4 weeks later in albino Swiss mice. Neuronal counts did not reveal any significant changes between the experimental groups. Comparative analysis of activated microglia and perineuronal nets by optical fractionators revealed significant differences between 15 and 18 weeks: the microglial total number increased in this period of time whereas perineuronal nets decreased (t test, two-tailed analysis p<0.05) Cluster and discriminant subsequent analysis applied to behavioral studies revealed that burrowing activity distinguished the occurrence of two subgroups with differential sensitivity to the ME7 agent: one group (40% of the subjects) where the disease progression is faster and the terminal stage is reached in 22 weeks and another one (60%) with slower progression and terminal stage at 26 weeks post-inoculation. The results are important for comparative studies of the immunoneuropathology of chronic neurodegenerative disorders in general and for prion disease itself.
Acesso aberto (Open Access)
Indução de escleróticas in vitro e análise da resposta imune dos pacientes de cromoblastomicose em tratamento com itraconazol
(Universidade Federal do Pará, 2009-06-26) SILVA, Moisés Batista da; SALGADO, Claudio Guedes; http://lattes.cnpq.br/2310734509396125
Chromoblastomycosis (CBM) is a chronic fungal disease witch affects the skin, characterized for slowing development of polymorphic skin, that present infiltrated inflammatory granulomatous in the presence of sclerotics cells, characteristic of this illness. One of the objectives of this study was to evaluate the induction of scleroticts cells for natural mediums, with biomasses of Bactris gasipaes and Theobroma grandiflorum, whose respective species had induced in vitro similar sclerotics cells to those found in tissue of patients, in 10 and 2 days, respectively, what it made possible the production of a powder medium inductor, already donated to other groups that study the CBM. Another objective was to evaluate the histopathology of the CBM in the patients, before and during the use of itraconazole (ITZ). For this, the technique of ELISA for the cytokines was used TNF-α, circulating IL-4 and IL-10, and the immunohistochemestry of biópsias in different times of treatment - that it allowed to analyze the quantitative and qualitative alterations of the cellular types during 12 months of the treatment with ITZ in the 200 dose of mg/dia - with antibodies anti- CD20, anti-CD8 and anti-CD68. How much the cytokines, the circulating IL-10 did not show significant change, while IL-4 and TNF-α had presented an increase of the levels throughout 12 months of treatment. In relation to the immunophenotyping, it had a significant reduction in the inflammatory process and the cellular infiltrated during 3 and 6 months of the treatment, whereas only to the 12 months had the significant regression of the number of sclerotics cells. The immunophenotyping disclosed that the macrophages are mainly located in the areas central areas of granuloma, whereas cells TCD8+ are in the periphery and cells TCD20+, which were found throughout the tissues, with a significant increase after 6 months of the treatment, returning to the initial levels after one year. The cytotoxic macrophages and lymphocytes were having presented a significant increase after 12 months of treatment with ITZ. These results demonstrate that the formation of granuloma in the CBM is similar to those observed in other granulomatous infectious disease, and that the presence of IL-4 and IL-10 can be related with the persistence of fungi in the injuries and with the difficulty of cure observed in these patients.
Acesso aberto (Open Access)
Impacto da mistura de amaranto adicionada de arroz na proporção de 30/70% sobre a defesa antioxidante de ratos desnutridos
(Universidade Federal do Pará, 2010-12-28) MENEZES, Maria Auxiliadora de; NASCIMENTO, José Luiz Martins do; http://lattes.cnpq.br/7216249286784978
Malnutrition was highly prevalent in developing countries, is an ancient evil that afflicts humanity, presents itself as a state of nutritional deficiency, with an overall deficit of calories and proteins, causing a lower supply of nutrients to cells. Some studies have shown evidence of interaction between malnutrition and oxidative stress caused by accumulation of reactive oxygen species that cause damage to the structure of biomolecules due to the deregulation of the production of oxidants and depletion of antioxidant defenses. In this study we evaluated the use of instant amaranth flour added rice at a ratio of 30/70% as a food supplement in the diet base used as a model of Para Induction of malnutrition in rats on oxidative stress in malnourished animals compared to controls and treated with supplemented diet. The model of malnutrition diet (RBDPA) was made respecting the quantities of food consumed routinely by the population of Pará, the second dietary survey carried out in the 70's by researchers at the Federal University of Pará, whereas the diet used as a treatment was prepared by adding the DBR-PA 30% of amaranth flour. The results of proximate composition and amino acid were performed in accordance with the standards of the Institute Adolfo Lutz (1995) and by atomic spectrophotometry. The control diet was used as it is available. For the study animals in the immediate postpartum mothers fed with control diet during pregnancy to rats (22% protein) with a minimum weight of 6 g at birth in the immediate postpartum mother rats were divided into three groups: Group control (22% protein); malnourished group (RBD-PA containing 7.8% protein) 3 treated group (RBD-PA + AA) supplemented with amaranth flour instant containing 11.33%). In the post weaning the animals were separated into individual cages and received specific maternal diet of each group until 60 days old when he was done and sacrificed to collect blood for biochemical testing (total cholesterol and fractions, values, blood counts (red blood cells, WBC and platelet counts), levels of lipid peroxidation and catalase activity. After blood collection the animals underwent liver resection for posterior histopathological analysis. The results revealed that the diet induces malnutrition is a model of severe malnutrition in the region eat north, is hipoproteic, normocaloric with limiting amino acid (methionine), has promoted weight loss in animals from the period of lactation with marked weight loss in rats and mother in the weaning pups (21 days), 28 and 60 days old (p <0.05) compared to animals treated with amaranth and controls. The diet supplemented with amaranth flour extruded promoted weight gain during the period of breastfeeding mothers in both rats (p <0.05) in the puppies as apartir the 14th day of using the same (p <0.05) at 21 days (weaning) (p <0.05) to 28 (p <0.05) and 60th days of life (p <0.05). Malnourished animals consumed more diet at all times evaluated and treated when compared to controls (p <0.05). There was no difference between groups in biochemical values of red blood cells, WBC, platelets, total cholesterol and fractions. levels lipid peroxidation did not differ between groups. Catalase activity was higher in the group treated with supplementation of amaranth flour when compared to both desnutridos.Os animals treated with amaranth as the undernourished have hepatic steatosis and inflammation in hepatocytes. The study revealed that malnutrition imposed did not cause oxidative stress, however, the decrease of catalase activity in malnourished animals may have been caused by decreased synthesis of catalase.
Acesso aberto (Open Access)
Alterações neuroquímicas no tecido retiniano murino em modelo de malária cerebral induzida pela infecção por Plasmodium berghei (ANKA)
(Universidade Federal do Pará, 2011-07-21) OLIVEIRA, Karen Renata Matos; NASCIMENTO, José Luiz Martins do; http://lattes.cnpq.br/7216249286784978
Cerebral Malaria (CM) is a severe complication resulting from Plasmodium falciparum infection. This condition has usually been associated with cognitive, behavioral and motor dysfunctions, being the retinopathy the most serious consequence resulting from the disease. The pathophysiologymechanisms underlying the complications of CM remain incompletely understood. Several experimental models of CM have already been developed in order to clarify those mechanisms related to this syndrome. In this context, the present work has been performed to investigate which possible neurochemistry alteration could be involved in the CM pathology. Male and female susceptible C57Bl/6 mice (6-8 week old) infected with ≈106 parasitized red blood cells (PbA), showed a low parasitaemia (15-20%), with evident clinical signs as: respiratory failure, ataxia, hemiplegia, and coma followed by animal death. In parallel to the clinical characterization of CM, retinal analysis demonstrated that the disease led to a decrease in the glutathione levels with 2 days post inoculation. However, this decrease was not so evident with the course of the infection (4º and 6º days post- infection). We further demonstrated that the increase in the glutathione levels during the infection is followed by the increase in the 3H-glutamate uptake rate (4º and 6º days post-infection), suggesting that CM condition causes an up-regulation of the transporters systems. Immunofluorescence data demonstrated that besides the activity increases, CM condition also stimulated the increase of the xCG- system expression in the retinal tissue. Furthermore, our findings also highlighted that in the retina the neurochemistries alterations occurs in a manner independent on the establishment of an inflammatory response, once TNF-α levels and NOS-2 expression were altered only in the cerebral tissue.
Acesso aberto (Open Access)
Alterações hematológicas, bioquímicas e histopatológicas no modelo de malária aviária Gallus gallus por Plasmodium gallinaceum: papel do óxido nítrico
(Universidade Federal do Pará, 2011-07-29) MACCHI, Barbarella de Matos; DAMATTA, Renato Augusto; http://lattes.cnpq.br/6212140983414786; NASCIMENTO, José Luiz Martins do; http://lattes.cnpq.br/7216249286784978
Malaria causes major losses to human populations in the world. Experimental models are needed for a better understanding of the pathological mechanisms of the diseases and the development of new treatments. Chickens infected with Plasmodium gallinaceum constitute an adequate malaria model due to the phylogenetic proximity of this parasite to human Plasmodium as well as similarities in disease manifestation, as cerebral malaria. The aim of the present study was to investigate the role of nitric oxide in avian malaria development in chickens experimentally infected with P. gallinaceum, treated or not with aminoguanidine (AG - nitric oxide synthase inhibitor). Survival, classical hematology, serum biochemistry and pathology was assayed during the development of the disease. The greatest survival was observed in animals treated with AG that also presented higher parasitemia. Decrease in hematological parameters and Mean Corspucular Volume of erythrocytes increase was showed, indicating bone marrow response to anemia. Lymphopenia and thrombocytopenia were detected in infected animals, but not at the same proportion in treated animals. Monocytes, lymphocytes and heterophils showed an increase in size and changes that indicated activation. Thrombocytes were also higher with the infection and with atypical morphology. Treated animals showed fewer lesions in histological sections of brain, liver and spleen, and NO production decreased, principally during high parasitemia, compared to untreated animals. These results characterize the participation of the chemistry mediator nitric oxide in the pathogenesis of malaria in the avian model.
Acesso aberto (Open Access)
Caracterização do mecanismo de ação antiinflamatória do flavonóide BAS1 isolado da planta Brosimum acutifolium
(Universidade Federal do Pará, 2011-08-02) MORAES, Waldiney Pires; SILVA, Anderson Manoel Herculano Oliveira da; DINIZ, Domingos Luiz Wanderley Picanço; http://lattes.cnpq.br/9601463988942971
Inflammation is the body's response to injury and danger. Even though it’s a body defensive mechanism, this response’s intensity and/ or persistency might be harmful for an individual. In such context, natural products are important sources of biologically active molecules, and they’re considered promising resources for the discovering of new drugs. Based on ethno pharmacological studies, BAS1 flavonoid (4'-hydroxy, 7, 8 - (2'', 2''-dimethyl-pyran)-flavan), which hasn’t been described by literature yet, was isolated from the Brosimum acutifolium plant, popularly known as "mururé da terra-firme." Facing this, the present study aimed at characterizing the anti-inflammatory mechanism of action of BAS1 flavonoid in stimulated murine macrophages. Macrophages were activated with LPS and IFN-γ, cell viability was evaluated by the MTT, levels of inflammatory mediators were determined by ELISA (TNF-α, PGE2, IL-10) through Griess reaction (NO) and protein expression by Western blotting. The results demonstrate that BAS1 only has cyclotoxic effects at high concentrations (100 μM) inhibited NO production (95%), negatively regulated the expression of NOS-2, reduced the TNF-α production (39%) and PGE2 (57%), but didn’t with IL-10 in activated macrophages. Thus, demonstrating the pharmacological effect of BAS1 flavonoid, as well as supporting the usage of the Brosimum acutifolium plant as an anti-inflammatory in our region was an important contribution from this study. Furthermore, the production of this plant’s extract could provide the local population with an effective and affordable anti-inflammatory. The present work may also contribute to the establishment of a new classification of anti-inflammatory agents, based on natural flavonoids, such as BAS1.
Acesso aberto (Open Access)
Alterações hepáticas por exposição a baixas doses de metilmercúrio em macacos prego, Cebus apella (Linnaeus 1758)
(Universidade Federal do Pará, 2011-09-16) SILVA, Márcia Cristina Freitas da; SILVEIRA, Luiz Carlos de Lima; http://lattes.cnpq.br/9383834641490219
Cebus apella were exposed to 1,5 ppm methylmercury (methylHg) in the diet for 120 days. Hepatotoxicity was investigated, concentrations of mercury in total blood were monitored each 30 days using atomic absorption spectrometry with cold vapor Hg201, aspartate transaminase (AST), alanine transaminase (ALT) and total bilirubin (BT) were determined. Liver was fixed by formaldehyde 10% and prepared by histopathology protocols. Significant difference was observed in groups exposed and control about total mercury (Hgtotal) in the periods of 60, 90 (P < 0,05) and 120 days (P < 0,01). The histopathology revealed moderate steatosis and hydropic degeneration, common in methylHg exposed in other species. No Significant difference between the levels of AST (p= 0.38), ALT (p= 0.83) and BT (p= 0.07) in groups exposed and control. The Pearson correlation with Hgtotal was negative (AST r= -0,7; ALT r=0,07; BT r= -0,3 e p > 0,05), suggests another studies to clarify the alert levels of mercury concentrations and liver dosages.
Acesso aberto (Open Access)
Pesquisa epidemiológica e molecular do vírus respiratório sincicial humano (VSRH) em amostras de pacientes hospitalizados com pneumonia, na cidade de Belém
(Universidade Federal do Pará, 2011-11-17) LAMARÃO, Letícia Martins; LINHARES, Alexandre da Costa; http://lattes.cnpq.br/3316632173870389
Childhood pneumonia and bronchiolitis is a leading cause of illness and death in young children worldwide with Respiratory Syncytial Virus (RSV) as the main viral cause. RSV has been associated with annual respiratory disease outbreaks and bacterial co-infection has also been reported. This study is the first RSV study in young children hospitalized with community-acquired pneumonia (CAP) in Belém city, Pará (Northern Brazil). It had the objective of determining the prevalence of RSV infection and evaluating the patients’ clinical and epidemiological features. Methods. We conducted a prospective study across eight hospitals from November 2006 to October 2007. In this study, 1,050 nasopharyngeal aspirate samples were obtained from hospitalized children up to the age of three years with CAP, and tested for RSV antigen by direct immunofluorescence assay and by Reverse Transcription Polymerase Chain Reaction (RT-PCR) for RSV subtype identification. Levels of C-reactive protein (CRP) and results of bacterial infection were also obtained. Results. RSV infection was diagnosed in 243 (23.1%) children. The mean age of the RSV-positive group was lower than the RSV-negative group (12.1 months vs 15.5 months, both ranged 1-36 months, p<0.001) whereas gender distribution was similar. The RSV-positive group showed lower CRP mean levels when compared to the RSV-negative group (15.3 vs 24.0 mg/dL, p<0.05). Radiological findings showed that 54.2% of RSV-positive group and 50.3% of RSV-negative group had interstitial infiltrate. Bacterial infection was identified predominantly in the RSV-positive group (10% vs 4.5%, p<0.05). Rhinorrhea and nasal obstruction were predominantly observed in the RSV-positive group. A co-circulation of subtypes A and B was noted, with a predominance of subtype B (209/227). Multivariate analysis revealed that age under 1 year (p<0.015), CRP levels under 48 mg/dL (p<0.001) and bacterial co-infection (p<0.032) were independently associated with the presence of RSV as opposed to RSV-negative group, and in analyze of symptoms, nasal obstruction were independently associated with RSV-positive group (p<0.001). Conclusion. The present study highlights the relevance of RSV infection in hospitalized cases of CAP in our region; our findings warrant the conduct of further investigations which can help design strategies for controlling the disease.
Acesso aberto (Open Access)
Avaliação de uma solução de água de coco (cocos nucifera) suplementada na produção in vitro de embriões bovinos
(Universidade Federal do Pará, 2011-12-02) CORDEIRO, Marcela da Silva; OHASHI, Otávio Mitio; http://lattes.cnpq.br/5547874183666459
Acesso aberto (Open Access)
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.
Acesso aberto (Open Access)
Caracterização comportamental e eletroencefalográfica das convulsões induzidas pelo cunaniol e acetato de cunaniol extraídos das folhas de Clibadium sylvestre, um modelo de convulsão generalizada experimental em ratos (Wistar)
(Universidade Federal do Pará, 2011-12-15) HAMOY, Moisés; NASCIMENTO, José Luiz Martins do; http://lattes.cnpq.br/7216249286784978
The Clibadium sylvestre is largely distribued in the Amazon region, where is know as cunambi or cunhambi, and its ingestion causes inebriation or even fish´s death, demonstrating ichthyotoxic property. The compounds existing in the leaf of Clibadium sylvestre are powerful of central nervous system stimulants, its leafs contain potential convulsivant substances. The electroencephalographic changes, seizure and drug effects on seizure behavior control were studied as well as metabolic pathway of compounds cunaniol acetate and cunaniol. The work was performed with adult male Wistar rats, treated with DE50 of 2,92 mg/kg or DL50 of 3,64 mg/kg of cunaniol, administration route used was intraperitoneal. After cunaniol administration, the seizure evolution was observed, it allows to classify them according to the presentation intensity relate to cunaniol plasma concentration. The eletroencefalografic parameters of the drugs action on the seizure control and the clinic characteristic were determined and evaluated. The plasma analysis obtained by liquid chromatography after the application of convulsivant substances indicates that the cunaniol acetate undergoes deacetylation giving rise to cunaniol, drug responsible for convulsive state. Data electrocorticography has been shown five different patterns of tracks during recording with 4 hours remaining changes outlined by 12 hours after application. Among the drugs used to prevent the onset of seizures, the most effective were diazepam, phenobarbital and ketamine. The convulsive behavior was classified into five stages. For the occurrence of stages 4 and 5 there was no statistical differences regarding plasma cunaniol.
Acesso aberto (Open Access)
Modelo experimental de imunossupressão com ciclofosfamida em Rattus norvegicus da linhagem wistar e primatas não humanos da especie Cebus apella: análise genotoxicológica
(Universidade Federal do Pará, 2011-12-23) SOUZA, Patrícia Carvalho de; BURBANO, Rommel Mario Rodriguéz; http://lattes.cnpq.br/4362051219348099
We established a model of immunosuppression in rats by inoculation of the alkylating agent Cyclophosphamide (CY). The administration of 50 mg/kg CY in Wistar rats caused a significant decrease in the parameters of cellularity, and relative weight of lymphoid organs. For analysis of antibody titre of the test on the plaque forming cells and hemolysis test was proven that the humoral immunity of rodents suffered suppression. Four inoculations were carried out and this immunosuppressive intervals between inoculations was determined by recovery of normal levels of the aforementioned parameters. The change in differential counts of white blood cells represented the greatest adverse effect of CY, observed in laboratory parameters analyzed in Cebus apella. Both times it was administered the drug decreased the number of lymphocytes and neutrophils subsequently decreased, but only in the second was observed immunosuppression. Since the phylogenetic proximity of nonhuman primates, this experimental design is of paramount importance for the study of tumors at various stages of development and mainly for testing new drugs and therapeutic regimens. With respect to genotoxicity analysis of CY can conclude that in Wistar rats, the administration of CY significantly increased frequency of micronuclei in polychromatic erythrocytes (MN ECPs) and caused a cytotoxic effect (P <0.05). In C. apella, the peripheral blood lymphocytes after treatment with CY showed a significant increase in media MN/1000 lymphocyte cells compared to control (P <0.05). The concentration of 50mg/kg of CY in C. apella, LD50 is the concentration of the drug, whereas 50% of these animals died during the trial of immunosuppression. Until the development of this work, do not know the concentration corresponding to the LD50 in this species. In comparing the two species of animals used in this work, non-human primates have a more rapid immune recovery compared to rats. Probably the ability to metabolize the drug is more effective in C. apella. Our results support, therefore, that non-human primates are the best experimental models due to its great evolutionary and phylogenetic proximity to humans.
Acesso aberto (Open Access)
Modelo in vitro de parkinsonismo experimental induzido por rotenona: investigação de mecanismos de ação, neuroproteção e morte celular
(Universidade Federal do Pará, 2011-12-29) MARTINS FILHO, Arnaldo Jorge; COSTA, Edmar Tavares da; http://lattes.cnpq.br/6776869402973569; YAMADA, Elizabeth Sumi; http://lattes.cnpq.br/7240314827308306
Increasing evidence has suggested a role for environmental factors, such as exposure to pesticides, in the pathogenesis of Parkinson’s disease. In experimental animals the exposure to rotenone, a common herbicide and piscicide, induces features of parkinsonism by inhibiting the activity of mitochondrial complex I. Here we propose to investigate rotenone-induced death of neurons by using primary neuron-enriched and neuron-glia cultures from the rat hippocampus and ventral mesencephalon. The neuronal loss was evaluated with the colorimetric MTT assay. Our results showed significant reduction in the cell viability after exposure to rotenone in a dose- but not in a timedependent manner. We also discovered a remarkable feature of rotenone-induced degeneration of cultured neurons. The higher susceptibility was observed in neuron-glia cultures from the ventral mesencephalon, suggesting that the presence of glia, especially microglia, is an important factor contributing to neurodegeneration. Also, as showed by immunohistochemistry, this type of culture presented the higher density of tirosinahidroxilase (TH)-positive neurons. Mechanistically, our results with calcium blockers showed a minimal role played by external calcium, and an important synergistic influence of the ions from the internal stores in the rotenone-induced neurodegeneration. Indeed, in this study, we report that aqueous extract of mahogany leaves didn’t protect against the rotenone-induced toxicity, in the used concentration; and promoted a synergistic effect when associated with rotenona. Finally, the mahogany leaves extract induced celular death both necrosis and apoptosis. The results of this study should advance our understanding of the mechanism of action for environmental factors in the pathogenesis of Parkinson’s disease.
Acesso aberto (Open Access)
Ativação microglial, lesão da substância branca e expressão de Nogo-A em ratos submetidos à isquemia estriatal
(Universidade Federal do Pará, 2012-05-10) LIMA, Rafael Rodrigues; LEAL, Walace Gomes; http://lattes.cnpq.br/2085871005197072
The objective of this investigation was to evaluate the degenerative pattern of several white matter tracts after striatal ischemic injury, correlating degenerative process standards with the microglial activation and expression of Nogo-A. For this purpose, focal ischemia was induced with stereotactic injection of endothelin in striatum of adult rats, and only in the control animals injected with sterile saline. The animals were perfused 3, 7, 14 and 30 days after ischemia. The brain removed, postfixed, cryoprotected, cut into cryostat sections obtained and submitted to immunohistochemical investigation with the following antibodies: anti-GFAP (1:2000, Dako), anti-Tau-1 (1:500, Chemicon), Anti-MBP (1:100, Chemicon International), Anti-Nogo-A (1:100, Invitrogen), Anti-Iba1 (1:1000, WAKO), ED1 (1:500, Serotec) and Anti-MHC II (Abcam 1:100), besides the viewing of the damage pattern with cresyl violet. Slides are marked by different methods were evaluated qualitatively and quantitatively also some (Anti-Nogo A, anti-ED-1, anti-MHC-II and anti-tau-1), counts were carried out in the striatum and in the corpus callosum. The data were tabulated, statistically analyzed by Tukey test (p <0.05) and micrographs taken of the findings more representative. The slides were stained with cresyl violet revealed an increase in cell density by the infiltration of inflammatory cells to the ischemic area, with a significant increase on day 7. The blades immunostained for GFAP was found progressive increase of the population of astrocytes and an increase in cell volume 7 and 14 days. Oligodendrocyte pathology marked with Tau-1 had peak marking the 3rd day in the striatum and the 7th day in the corpus callosum, and loss of myelin compaction identified by MBP was better at 14, in the different treatment. The microglial activation identified by different immunoblots showed a peak on day 7, both in striatum and in the corpus callosum, but in the corpus callosum with a much smaller number compared to the striatum. The morphology of microglial underwent changes, which found the branched phenotype in control animals, as well as in early and late times after ischemia and amoeboid default / phagocytic day 7, coinciding with the largest number of activated cells. The count of Nogo-A + cells peaked at 3 days observed in the striatum, and there were no differences in the corpus callosum expression Nogo-A 3 to 14 days, only a decrease compared to 30 days. Thus, microinjections of ET-1 induced conspicuous striatal tissue loss, concomitant with progressive microglial activation, astrocytosis, loss of immunoreactivity for myelin basic protein and oligodendrocytes damage in various survival times after focal ischemia. These events affect a few SB tracts, as the corpus callosum. The establishment of the temporal evolution of these events is the neuropathological basis for future studies, in which they should handle the inflammatory response in order to minimize these tissue changes.
Acesso aberto (Open Access)
Avaliação in vitro dos possíveis efeitos citotóxicos, genotóxicos e mutagênicos das drogas antimaláricas artemisinina e artemeter em linfócitos humanos
(Universidade Federal do Pará, 2012-05-25) CARDOSO, Plínio Cerqueira dos Santos; BAHIA, Marcelo de Oliveira; http://lattes.cnpq.br/3219037174956649; BURBANO, Rommel Mario Rodriguéz; http://lattes.cnpq.br/4362051219348099
Artemisinin is a substance extracted from the Chinese plant Artemisia annua L., and widely used in natural medicine for a treatment of various diseases. Artemether is a substance synthesized from artemisinin. These drugs belong to a special group of molecules called sesquiterpene lactones widely administered in the treatment of malaria. Although considered effective anti-malarial drugs, very little is known about the genotoxic and cytotoxic effects of these drugs. Therefore, in the present study, we evaluated the genotoxic, mutagenic and cytotoxic effects of artemisinin and artemether in cultured human lymphocytes using the comet assay, the micronucleus test and a cytotoxicity assay for detection of necrosis and apoptosis by fluorescent differential acridine orange/ethidium bromide (LA/BE), respectively. Our results showed a significant increase (p<0.05) in the rate of DNA damage measured by comet assay and in the micronucleus frequency after treatment with both drugs. It was also observed that only artemisinin induced a statistically significant increase (p<0.05) in the number of lymphocytes with death by necrosis 48 h after treatment. Thus, it was shown in our work that these two drugs exert mutagenic, genotoxic and cytotoxic effects in cultured human lymphocytes under the conditions evaluated. Our data indicate the need for caution in the use of such drugs, since genotoxic/mutagenic effects may increase the risk of carcinogenesis.
Acesso aberto (Open Access)
Perda neuronal, ativação glial, neurogênese e alterações sensório-motoras após isquemia focal no córtex somestésico de ratos adultos
(Universidade Federal do Pará, 2012-09-26) CORRÊA, Vania Castro; LEAL, Walace Gomes; http://lattes.cnpq.br/2085871005197072
Stroke is considered one of the most important causes of death and functional deficits in the world. Few neurological conditions are so complex and devastating, resulting in severe neurological deficits and death in the survivors. The cortical regions are commonly affected by stroke, resulting in sensory and motor loss. The establishment of neuropathological patterns in cortical regions, including the somatosensory area, is critical for the investigation of possible therapeutic interventions. In the present study, we investigated the patterns of neuronal loss, microgliosis, astrocytosis, neurogenesis and functional deficits in the primary somatosensory cortex of adult rats submitted to focal ischemia induced by microinjections of 40 pmol of endothelin-1 (ET-1). A total of 30 young adult Wistar rats (Rattus norvegicus) of Wistar, weighing between 250-280g were used in the study. The animals were divided into ischemic (N = 21) and control (N = 9) groups. They were perfused at survival times of 1, 3 and 7 days. The 7 days animals were submitted to behavioral tests to evaluate sensorimotor impairment. Sections were stained with cresyl violet, cytochrome oxidase and immunostained to identify neurons (anti-NeuN), activated and non-activated microglia (Iba-1), activated macrophages/microglia (ED-1), astrocytes (GFAP) and neuroblasts (DCX ). Statistical comparisons between groups were made by one analysis of variance (ANOVA) with Tukey post-hoc test. The animals showed ischemic sensorimotor deficits revealed by Bederson Neurological Scale, Paw Placement and corner tests. Microinjections of ET-1 induced focal ischemic lesion in the primary somatosensory cortex with neuronal loss and progressive astrocytosis and microgliosis mainly in the late survival times. The cytochrome oxidase histochemistry revealed the barrel fields, but unexpectedly marked a population of inflammatory cells with macrophage characteristics in the ischemic region. Increased numbers of SVZ neuroblasts were observed mainly in late survival times of ipsilateral hemisphere in comparison to contralateral side and control animals. There was no significant migration of neuroblasts to the ischemic cortex. The results show that microinjections of ET-1 are an effective method for inducing tissue loss and sensorymotor deficits in the primary somatosensory cortex of adult rats. It was evident that the SVZ is influenced by distant ischemic events distant and that macrophage populations seem to increase the cytochrome oxidase expression. The implemented experimental model can be used in future studies, in which potential neuroprotective drugs can be tested to minimize the described neuropathological alterations.
Acesso aberto (Open Access)
Análise comparativa dos padrões neurodegenerativos da substância cinzenta em diferentes áreas corticais de ratos adultos submetidos à lesão isquêmica focal
(Universidade Federal do Pará, 2012-09-27) SANTOS, Enio Maurício Nery dos; LEAL, Walace Gomes; http://lattes.cnpq.br/2085871005197072
Stroke can occur in any region of the central nervous system (CNS). The cerebral cortex is one of the most often affected areaby this acute neural disorder, but there are no studies that have compared the damaging pattern in different cortical regions after acomparable focal ischemia. The aim of this investigation was to evaluate the degenerative pattern of different cortical areas after focal ischemic injury. Focal ischemia was induced by stereotaxic microinjections of endothelin-1 (ET-1) into the somatosensory, motor and association cortices of adult rats (N = 45). The control animals were injected with the same volume of sterile saline (N = 27). The animals were perfused 1, 3 and 7 days after the ischemic event. The brain was removed, postfixed, cryoprotected, and sectioned in a cryostat. The general histopathology was evaluated in 50μm sections stained with cresyl violet. 20μm sections were submitted to immunohistochemistry for astrocytes (anti-GFAP), activated microglia / macrophages (anti-ED1) and overall microglial population (anti-Iba1). The damaging patterns werequalitatively evaluated under optical microscopy and quantitatively by counting the number of cells in the ipsilateral and contralateral sides to injury.Descriptive statistics and comparisons within and between groups were performed using analysis of variance with Tukey post-hoc test. Conspicuous ischemic tissue loss, microglial activation and astrocytosis were observed mainly 3 and 7 days after ischemia, which was not observed in control animals. The tissue loss and activation of glial cells were more intense in the somatosensory cortex, followed by the motor cortex. The association cortex displayed less damage compared to other cortical areas, which was confirmed by quantitative analysis. The results suggest that an ischemic lesion of the same intensity induces a differential pattern of tissue loss and neuroinflammation, depending on the cortical area, and that the primary sensory and motor areas are more susceptible to ischemia than association areas.
Acesso aberto (Open Access)
Prevalência e associação da infecção por Helicobacter pylori e do vírus de Epstein-Barr em adenocarcinoma gástrico, em uma população do norte do Brasil
(Universidade Federal do Pará, 2012-12-13) FERRAZ, Jefferson José Sodré; QUARESMA, Juarez Antônio Simões; http://lattes.cnpq.br/3350166863853054; BURBANO, Rommel Mario Rodriguéz; http://lattes.cnpq.br/4362051219348099
Gastric neoplasias are the second leading cause of cancer-related deaths and although discoveries over physio-pathology of tumour cells, cancer is considered, to the best of our knowledge, minimally controlled by modern medicine. Gastric carcinoma is among the few malignant neoplasms in which infectious agents play an important role. The aim of the present work was to research the prevalence and the association of Helicobacter pylori and Epstein-Barr virus infection in gastric adenocarcinoma in a northern population of Brazil. A hundred twenty-five samples of gastric adenocarcinoma were analyzed by PCR to detect H. pylori and pathogenic genotype H. pylori-cagA+, by in situ hybridization to detect EBV, and by histopathological analysis to determine epidemiologic and clinico-pathological data. It was observed a higher frequency in male patients (68%) as much as older patients (78%). Prevalence to H. pylori was 88%, and it was considered high when compared to early studies in northern region of Brasil. To EBV the prevalence was 9,6%. Patients H. pylori-cagA+ showed increased relative risk to intestinal type adenocarcinoma. The case’s frequency to III and IV stages of the disease was 82,4%, demonstrating that the diagnostic to this neoplasia has been done late. The urease positive cases presented a higher than four-fold relative risk (OR=4,231) to H. pylori-cagA+, the more pathogenic genotype. There wasn’t statistical significance to the association between H. pylori and EBV in the studied population; however the EBV positive cases showed 100% positivity to H. pylori suggesting a possible synergistic relation of these agents in gastric carcinogenesis.