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).
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Item 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/7216249286784978Malaria 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.Item Acesso aberto (Open Access) Alterações histopatológicas dos rins de macacos prego, Cebusapella (Linnaeus 1758) após exposição crônica a baixas doses de metilmercúrio(Universidade Federal do Pará, 2014-02-28) SOUSA, Andréa do Socorro Campos de Araújo; SILVEIRA, Luiz Carlos de Lima; http://lattes.cnpq.br/9383834641490219Mercury has been a major environmental and occupational risk and it still remains a problem for human health in the Amazon region. Although studies have shown that mercury affects various tissues and organs, kidneys are the target organs to the metal toxicity. Thus, the aim of this study was to investigate the effects of chronic exposure to low doses of methylmercury on renal parenchyma of Cebusapella, adult males exposed during 120 consecutive days with daily oral doses of 1.5 μg in the diet. The concentrations of total mercury in the animals’ blood were monitored every 30 days using a cold vapor atomic spectrophotometer (201 Hg), compared to the control group. The method used for histopathological analysis was the immersion in paraffin for staining with hematoxylin and Eosin, Masson's CAB and PAS. The immunohistochemical investigations included reactions for detection of smooth muscle actin ( IA4 ), muscle actin ( HHF35 ) and cytokeratin (AE1 and AE2). The results showed that treatment with mercury caused significant differences (P < 0.001) between the exposed and control groups. As for total Hg levels, histopathologicalchanges just likehydrops in Proximal tubuleswere observed, a common finding in methylmercury exposure in other species, with no significant changes in creatinine and urea concentrations. The Person correlation test showed a strong negative relationship between mercury concentration and animal body weight loss (P < 0.0001). Another important finding was the decrease in mesangial cells number, which suggests that methylmercury executed its nephrotoxicity, affecting not only the renal tubular system, as well as the glomerular mesangium cells, making necessary a greater amount of experimental studies to clarify which mercury concentration alert level is capable of triggering aggression mechanisms and kidney injury in subjects exposed to methylmercury.Item 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/7216249286784978Cerebral 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.Item Acesso aberto (Open Access) Atividade antiproliferativa e antineoplásica de flavonóides da espécie Brosimum acutifolium em modelo de glioblastoma in vitro(Universidade Federal do Pará, 2013-05-24) MAUÉS, Luis Antônio Loureiro; NASCIMENTO, José Luiz Martins do; http://lattes.cnpq.br/7216249286784978Among the tumors that affect the nervous system, glioblastoma multiforme (GBM) is notable by its high degree of aggressiveness and poor prognosis, with an average survival of 15 months from diagnosis. The present study aimed to investigate the antiproliferative and antineoplastic activity of four flavonoids isolated from species Brosimum acutifolium (Huber). two flavans: 4'-hydroxy-7,8-(2",2"-dimethylpyran)-flavan (BAS-1) and 7,4'-dihydroxy-8-(3,3-dimethylallyl)-flavan (BAS-4), and two chalcones: 4,2'-dihydroxy-3',4'-(2",2"-dimetilpirano)-chalcone (BAS-6) and 4,2',4'-trihydroxy-3'-(3,3-dimethylallyl)-chalcone (BAS-7), tested on rat C6 glioblastoma in vitro. Our results showed good cytotoxic activity for flavans (BAS-1, -4) and the chalcone BAS-7, with IC50 less than 100 μM in the MTT viability test, since the chalcone BAS-6, showed no cytotoxicity at the concentrations tested. These flavonoids showed less cytotoxity for non-neoplastic cell (glia), with higher degree of security for the BAS and BAS-4-7, once showed lower cytotoxic effect on non-neoplastic cell, and less hemolytic. Analysis of cell migration showed that treatment with BAS-1; -4 and -7 at low concentrations was effective in promoting the inhibition of cell migration. These three flavonoids were also very promising in inhibiting colony formation and growth, and promote cell cycle arrest with a substantial increase in population SubG0 for treatment with BAS-1 and -4 with 100 μM. The flavans BAS-1 and -4 also showed increased ability to promote losing in the integrity of the mitochondrial membrane potential (ΔΨm) and increased for staining with Annexin V, indicating that these drugs cause death by apoptosis. However the analysis by electron microscopy showed markedly the presence of autophagic vacuoles in the treatment with BAS-4 suggesting that the process of cell death occurs by apoptosis as well as autophagy. Based on these results it can be concluded that the flavonoids BAS-1, -4, and -7 have potential as an anticancer agent in the therapy of GBM and BAS-4 is the most promising of all.Item 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/5547874183666459Item 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/4243976484500835The 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.Item 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/7216249286784978Malnutrition 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.Item 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/3219037174956649Psyllium 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.Item Acesso aberto (Open Access) Modulação dos sistemas GABAérgico e glutamatérgico na secreção hipotalâmica de ocitocina sob condições hiperosmóticas(Universidade Federal do Pará, 2014-04-07) GRISÓLIA, Alan Barroso Araújo; SILVA, Anderson Manoel Herculano Oliveira da; http://lattes.cnpq.br/8407177208423247; DINIZ, Domingos Luiz Wanderley Picanço; http://lattes.cnpq.br/9601463988942971In mammals, the osmolality of extracellular fluid is a main factor for maintenance hydro electrolyte balance. Thus, changes in osmolality are detected by specialized hypothalamic cell, thereby starting a neurochemical signaling with glutamatergic and GABAergic system involvement, which may trigger the oxytocin release. However, the way of GABA glutamate aminoacids relationship could modulate the oxytocin release under hyperosmolality is till poorly understood. In this context, the aim in present study was characterize the hypertonic medium effect in GABA glutamate extracellular levels and its relationship with oxytocin release in the hypothalamus in vitro. For this, male wistar rats (270-300g) were kept under standard laboratory conditions. After decapitation, the brain was quickly removed and the hypothalamic fragments were immediately dissected in cold Krebs Ringer Bicarbonate Glucose Buffer (KRBG), and were transferred to perifusion chambers containing KRBG isotonic (280 mOsm/Kg H₂O), at flow rate of 0.5-1.0 ml/min, medium effluent was collected every during 15 min. The hypertonic stimulation (340 mOsm/kg H2O) was performed during 3 minutes. Glutamate, GABA and oxytocin levels were determined by reverse phase high-performance liquid chromatograph (HPLC) system. The measurements of glutamate showed an increased release only after decrease in GABA concentration. This release temporal profile motivated us to add GABA (3 mM) during osmotic stimulation, resulting in blockage of glutamate release previously observed. Moreover the results showed oxtocin release by hypertonic solution may also depend on a GABA decrease. The present study suggests that oxytocin release stimulated by hypertonicity depends on altering the relationship GABA / glutamate.Item Acesso aberto (Open Access) Regeneração tendínea em modelo murino: estudo da plasticidade central e investigação do efeito da modulação nitrérgica na plasticidade periférica(Universidade Federal do Pará, 2015-08-10) MORAES, Suellen Alessandra Soares de; SILVA, Anderson Manoel Herculano Oliveira da; http://lattes.cnpq.br/8407177208423247Tendon injuries cause strong impact on people due to pain and functional limitation resulting therefrom. After injury, the tissue starts to present a network of nerves. Furthermore, there is evidence for the occurrence of central plasticity after injury. Among the molecular factors involved in injury repair, nitric oxide (NO) is implicated in tissue remodeling, but its effects are not yet well understood. The purpose of this study is to ascertain the existence of central plasticity and the influence of NO in peripheral plasticity, functional limitation and tendon regeneration in murine model. To study the effects of NO in peripheral plasticity, we used control animals (CTRL, without injury) or animals treated with saline (SAL, 0.9% NaCl), L-nitro-arginine-methyl-ester (L-NAME, NO-synthesis inhibitor) and sodium nitroprusside (SNP, NO donor) every other day until the 21st day post injury (DPI). To evaluate central plasticity (L5 segment), an injury was performed alone and the spinal cord collected at 2 or 21 DPI. We analyzed the integrity and tissue organization in tendon samples by H&E, transmission electron microscopy and immunofluorescence, which was also used to evaluate peripheral plasticity. To assess tendon functional recovery, we determined the Achilles functional index, the joint angle and the open field. In spinal cord studies, we investigated glial reactivity and neuron involvement after injury by co-localizations with the cell activation indicator c-Fos. The findings of this research show that NO inhibition promotes tissue organization in association to an increase in collagen synthesis, secretion and deposition. Besides, L-NAME local administration seems to favor cell differentiation to tenocyte-like morphological types and improve the organization of nerve branches in between the collagen mesh in correlation with functional recovery at 21 DPI. On the other hand, increased levels of NO by SNP promoted worsening in almost all parameters analyzed. Our data also show tendon injury triggers a central plasticity process with an increase in glial reactivity at 2 DPI and ipsilateral cell activation at 2 and 21 DPI. Afterall, our findings point out occurrence of central plasticity after tendon injury and favoring of tissue repair and peripheral plasticity through nitrergic blockage, unraveling fundamental aspects of tissue recovery that may represent new targets for a therapeutical approach in tendon injuries.