Dissertações em Neurociências e Biologia Celular (Mestrado) - PPGNBC/ICB

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/2375

O Mestrado 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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Acesso aberto (Open Access)
Alterações oxidativas em portadores da doença de Alzheimer: correlação com os estágios da doença e o quadro cognitivo dos pacientes
(Universidade Federal do Pará, 2012-06-22) FUJIHARA, Satomi; FREITAS, Jofre Jacob da Silva; http://lattes.cnpq.br/2023282005842112; LIMA, Patrícia Danielle Lima de; http://lattes.cnpq.br/3411620003450812
The survival of the population has increased gradually and it is correlated with quality of health services and general living conditions, being particularly marked in industrialized countries. The increase in life expectancy affects the incidence of age-associated diseases. Aging is considered a risk factor for the development of neurodegenerative diseases like Alzheimer’s disease (AD). One theory on the pathogenesis of AD postulates that neurodegeneration is the result of oxidative stress and damage to vulnerable cerebral tissues. The fact that aging is a risk factor in AD also reinforces the hypothesis of free radicals involvement, because the effects of their actions can accumulate for years. It is an insidious, progressive disease and is characterized clinically by progressive loss of memory and other cognitive functions, as well as behavioral and social changes. The memory deficit is the main and usually the first symptom of AD, especially with deficiency of retention and recall of new information. The present study aims to evaluate if there are changes in oxidative metabolism detected in the blood of patients with AD, and if there is correlation with different stages of the disease and the patients’ cognitive framework. We evaluated 30 patients with Alzheimer’s disease and 28 subjects in the control group attended at Unit Education and Assistance Physical Therapy and Occupational Therapy at the University of Pará (UEAFTO-UEPA). Oxidative metabolism was assessed by measuring the total antioxidant capacity equivalent to Trolox (TEAC) and measuring the levels of substances that react with thiobarbituric acid (TBARS). Neuropsychological tests were also performed on all participants in the study. No significant correlations were observed in the performance of neuropsychological tests to the levels of TBARS and TEAC in patients with AD. It was observed that the total antioxidant capacity (TAC) was significantly decreased in AD patients compared to controls whatever stage of disease, showing a possible relationship between TAC and AD. In the evaluation of TBARS was a trend toward higher concentrations in AD patients than in control group but the difference was not statistically significant, only the moderate stage was significant when compared with the control group. Evaluation of the lipidic peroxidation through TBARS a biomarker would probably not be suitable for Alzheimer's disease.
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Análise citogenética de duas espécies do gênero Hylaeamys (Rodentia: Cricetidae) por citogenética clássica e molecular
(Universidade Federal do Pará, 2013-04-05) PINTO, Jamilly Amaral; NAGAMACHI, Cleusa Yoshiko; http://lattes.cnpq.br/8887641213110093
Rodents are one of the largest and oldest orders of the class Mammalia. In South America, the order Rodentia compromises about 42% of mammal species, and from this more than 50% belong to the family Cricetidae, which includes the subfamily Sigmodontinae. The genus Hylaeamys is inserted in the tribe Oryzomyini and corresponds to one of 10 new genera proposed for species and species groups within Oryzomys. Hylaeamys is the equivalent of "megacephalus group", and consists of the species H. acritus, H. laticeps, H. megacephalus, H. perenensis, H. oniscus, H. tatei and H. yunganus, distributed in Venezuela, Trinidad, Guyana, Paraguay and Brazil, in areas of the Amazon rain forest, Atlantic rainforest and savannah. This study aims to analyze chromosomal markers in two species of the genus Hylaeamys, providing data to assist in its taxonomic and cytogenetic characterization. Nineteen samples of Hylaeamys megacephalus (HME) and four samples of Hylaeamys oniscus (HON) were analyzed. HME has 2n = 54 and HON, 2n = 52. The results obtained by G- and C-banding and Fluorescent In Situ Hybridization with whole chromosome probes from Hylaeamys megacephalus made it possible to determine the chromosomal characteristics of the species studied, as well as allowing a comparative analysis between them, and in comparison with Cerradomys langguthi, observing homeologies and karyotypic differences. The two species of Hylaeamys differ by a centric fission/fusion rearrangement in which HON shows the association of the pairs 14/19 of HME. This association is shared with CLA with an inversion (19/14/19). This work is an achievement for phylogeny and chromosomal studies on the genus Hylaeamys.
Acesso aberto (Open Access)
Análise citogenética de profissionais de serviços de radiologia clínica expostos à radiação ionizante na cidade de Belém, Pará, Brasil
(Universidade Federal do Pará, 2011-05-06) CUNHA JUNIOR, Luiz Raimundo Campos da Silva e; BURBANO, Rommel Mario Rodriguéz; http://lattes.cnpq.br/4362051219348099
Acesso aberto (Open Access)
Análise citogenética em morcegos da família Emballonuridae (Chiroptera) da Amazônia Brasileira através de citogenética clássica e molecular
(Universidade Federal do Pará, 2011-04-29) ARAÚJO, Ramon Everton Ferreira de; PIECZARKA, Julio Cesar; http://lattes.cnpq.br/6644368250823351
This is the first description of the karyotypes of bats of the family Emballonuridae from the Brazilian Amazon region. The species studied were Cormura brevirostris-CBR (2n=22; NF=40), Rhynchonycteris naso-RNA (2n=22 and NF=36), Saccopteryx canescens-SCA (2n=24 and FN=38) and Saccopteryx leptura-SLE (2n=28 and NF=38), characterized by G-, C-banding, NOR-staining and Fluorescent In Situ Hybridization (FISH). In CBR the karyotypes found had the same diploid number and fundamental number than in literature. FISH with ribosomal DNA probes and Ag-NOR staining showed two NOR places. Hybridization with telomeric probes showed that the sequences were found in the centromeres of all chromosomes but the Y. Using meiotic studies, chromosome banding and FISH with a whole X chromosome probe from Phyllostomus hastatus (Chiroptera, Phyllostomidae) we suggest that the sex chromosome pair of this species is not the one described in the literature. Cells in diploid and diakinesis had a ring conformation with four chromosome pairs, what suggests multiple reciprocal translocations among these chromosomes, a very rare situation in vertebrates and never found in eutherian mammals. The analyses of RNA, SCA and SLE shows that the karyotypes of Emballonuridae are very conservative even when compared with samples collected geographically very far, but the C-banding analyses shows that it can happen intraspecific variations in the constitutive heterochromatin. For the first time the Nucleolar Organizer Regions were described, showing a stained pair of chromosomes on each analyzed species. The FISH with 18S rDNA probes agrees with the Ag-NOR staining. FISH with human telomeric probes showed hybridizations in the distal portion of all chromosomes. These works are Important to understand the biodiversity of bats from the Amazon region, as well as the comprehension of the chromosomal evolution of Chiroptera.
Acesso aberto (Open Access)
Análise de células-tronco adultas (CTA) em cultura de células de tecido epitelial de pequenos roedores (rodentia-stricognathi- sciurognathi)
(Universidade Federal do Pará, 2012-11-13) RISSINO, Jorge Dores; PIECZARKA, Julio Cesar; http://lattes.cnpq.br/6644368250823351
The Adult Stem Cells (ASC) are non-specialized multipotent cells found in the bone marrow, peripheral blood, cornea, retina, brain, muscles, dental pulp, liver, pancreas, skin epithelium, digestive system, umbilical cord and placenta. These cells can indefinably reproduce and renew themselves and, under some stimulation, to change into specialized cells of different tissues or organs. The present work had the aim of obtaining ASC from epithelial tissues from wild rodents of different species (Oecomys concolor – one female, Proechimys roberti – two males, Hylaeamys megacephalus – two males). The methodology for isolation and in vitro culture of epithelial tissue following the previously described protocols, as well as the analysis after cryopreservation of morphology, genome stability, counting and cells viability, clonogenic potential and differentiation on osteocytes, chondrocytes and adipocytes. The ADC were characterized as a homogeneous population of in vitro growing cells adherent to plastic surfaces, which has a morphology similar to fibroblasts and with fusiform shape, with high growing rate and cell proliferation form many successive passages, where the clonogenic assays evaluated the cell renewing. On checking the genome stability on P3, the entire sample had stable karyotypes with the correct diploid number. The methodology for ASC differentiation into osteocytes, chondrocytes and adipocytes cell lines was satisfactory and the cells demonstrated the staining with Alizarin Red S, Alcian Blue and Oil Red O, respectively. The entire sample had capacity of proliferation and differentiation, being a potential source of skin ASC. These species can be used as models for ASC studies.
Acesso aberto (Open Access)
Análise de mutações no gene GJB2 em indivíduos com deficiência auditiva neurossensorial não sindrômica
(Universidade Federal do Pará, 2012-11) PAULA, Danilo Monteiro de; SILVA FILHO, Manoel da; http://lattes.cnpq.br/2032152778116209
Deafness is the most frequent sensorial defect in human beings and it may have different causes since environmental to hereditary. In developed countries the estimates suggest that in each 1000 births some kind of deafness is expressed and more than 60% of the cases have a genetic origin. In Brazil, the hereditary deafness is not well-known. It is believed that four in each thousand newborns express some kind of hearing defect and that the frequency of deafness caused by genetic factors is estimated in 16%, while the 84% remaining cases are caused by environmental factors and have an unknown etiology. The many forms of hereditary deafness already identified are very rare, except for the one which is caused by mutations in the GJB2 gene which codifies the connexin 26. The connexins represent a class of a protein family which is responsible for the formation of communications channels between adjacent cells (Gap Junctions), this communication is fundamental for the growth and differentiation of the tissues. Until now there have been described 102 mutations of GJB2 gene which are associated to the hereditary deafness. Three mutations stand out because they have high frequency in specific population groups: 35delG among Europeans and Brazilians, 167delT among Ashkenazi Jews, and 235delG among Asians. In this study, we performed a molecular analysis of the entire coding sequence of the GJB2 gene (Connexin 26) in a population sample consisted of 30 unrelated individuals with prelingual nonsyndromic sporadic deafness from the population of Belém do Pará. DNA was obtained by peripheral blood samples and analyzed by the conventional PCR followed by automatic sequencing. Mutations in the Connexin 26 gene were found in 20% of the sample (6/30). The mutations 35delG and R143W were observed in one patient (1/30), both in the heterozygous and related to the patient’s deafness. Two additional mutations were observed in different individuals: G160S in a patient corresponding to 3.3% (1/30), and V27I was observed in 4 patients with allele frequency of 0.08; however mutations G160S and V27I are not related deafness. In this work the observed frequencies of mutations are equivalent to the frequencies observed in other populations previously studied. These results indicate that mutations in the GJB2 gene are important causes of deafness in our region and it cannot be excluded that the possibility of deafness presented by some individuals may be caused, mainly, by environmental factors such as infectious processes occurring during pregnancy or the first months of life.
Acesso aberto (Open Access)
Análise morfológica in vitro da ação de antifúngicos em cepas de Fonsecaea pedrosoi
(Universidade Federal do Pará, 2014-02-21) MASSOUD JUNIOR, Heleno Ramos; SALGADO, Claudio Guedes; http://lattes.cnpq.br/2310734509396125
Choromoblastomycosis (CBM) is a disease caused by traumatic implantation of many species of melanized fungi. The State of Pará is the major endemic area in Brazil and Fonsecaea pedrosoi is the major etiological agent. The treatment is not standardized and many forms of interventions are related in the literature. In the other hand, the in vitro susceptibility test to antifungal drugs may help in the therapeutic choice and in the identification of resistant strains. The objective of this work is to evaluate the in vitro susceptibility of 20 F. pedrosoi clinical isolates to itraconazole (ITZ), ketoconazole (KCZ), fluconazole (FCZ) and terbinafine (TBF) as well as the possible morphological alterations induced by ITZ or TBF in the Minimal Inhibitory Concentration (MIC) and high concentrations. The tests were performed according to the Clinical and Laboratory Standards Institute (CLSI, M38-A2 document) recommendations. The final concentrations of ITZ, TBF and KCZ in each test were to 16 to 0.03 μg/mL. To FCZ the final concentrations were to 64 to 0.125 μg/mL. The MIC was defined as the lowest drug concentration that inhibit 100% the visual growth when compared to the non-treated group after five days of incubation at 30°C. ITZ proved to be the most effective drug in vitro against F. pedrosoi (CIM 90= 1μg/mL). TBF showed a low drug activity with 70% of the isolates with MIC ≥ 0.5 μg/mL. The conidia morphological analysis revealed an increasing in the diameter, an interruption of the cellular division and the formation of little chains after the treatment with ITZ in the MIC. At the high concentration used in the susceptibility test we noticed an irregular shape, a detachment of pigmented material from the cell wall and a vacuolization. Rupture in cell wall and amorphous conidia were observed at 32 μg/mL and 64 μg/mL. Significant alterations were not observed after treatment with TBF at the same concentrations. Moreover, the 5-fluorocytocise (5-FC) and FCZ do not stop the conidia growth at high concentrations. However, ultrastructure alterations were noticed after treatment with 5-FC 64 μg/mL. Thus, it is suggested a different morphological pattern after ITZ or TBF treatment during the in vitro susceptibility test. In synthesis, ITZ shown better in vitro antifungal activity while 5-FC only provoked structures alterations in the highest concentration tested.
Acesso aberto (Open Access)
Ativação microglial, perda neuronal e astrocitose em um modelo experimental de epilepsia do lobo temporal
(Universidade Federal do Pará, 2011-05-12) FERREIRA, Elane de Nazaré Magno; LEAL, Walace Gomes; http://lattes.cnpq.br/2085871005197072
Epilepsy is one of the most prevalent serious chronic neurological conditions worldwide. The World Health Organization (WHO) estimates 45-50 cases in 100,000 habitants in developed countries, rising to 122 to 190, in developing countries, including Brazil. There are no risk factors in relation to gender, race or age, but it is believed that some gene mutations are associated with an increased risk to develop the disease. The pathophysiology of epilepsy involves complex factors such as loss inhibition and increased neuronal excitability in different brain regions, but mainly at the hippocampus. Mutations in ion channels and in both receptor and neurotransmitter transporters may underlie disease pathogenesis. The inflammatory response plays an important role on epilepsy pathophysiology. Recent experimental evidence suggests a major role for both microglia and astrocyte activation on the seizure exacerbation. In this dissertation, we describe the general patterns of microgial and astrocyte activation and neuronal loss in CA1, CA3, hippocampal hylus, peririnal, lateral entorrinal and motor cortices and amigdaloid complex in the first week following “Status Epilepticus” induced by pilocarpine injection. Immunohistochemistry was performed to label neurons (anti-NeuN), microglia in general (anti-Iba1), activated microglia/macrophages (anti-ED1) and astrocytes (anti-GFAP). Numbers of neurons and activated microglia were counted in the hippocampus. There was intense microglia and astrocyte activation in all motor and limbic regions studied, mainly at 3 and 7 days post SE. Minocycline treatment reduced microglia activation in the hippocampus (p<0.05), without affecting astrocytosis. There was considerable inflammation in regions outside the hippocampus with an early inflammatory response. There was no neuronal loss in the hippocampus in the first week following SE, although sporadic alterations on neuronal morphology have been observed. These results suggest that the inflammatory response is an early and generalized histopathological event in several motor and limbic structures following pilocarpine-induced SE, even in the absence of conspicuous cell loss. The patterns of microglia and astrocyte activation can be used as markers of the progressive tissue impairment in the experimental models of epilepsy.
Acesso aberto (Open Access)
Avaliação de biomarcadores sorológicos em um estudo de busca ativa de casos novos de hanseníase em área hiperendêmica
(Universidade Federal do Pará, 2016-10-07) GOBBO, Angélica Rita; SALGADO, Claudio Guedes; http://lattes.cnpq.br/2310734509396125
Leprosy is a cronic infection diasease clinically characterized by changes in tactile, thermal and painful sensitivity in skin and peripheral nerves. Due to the absence of laboratory diagnosis of leprosy, new tools that contribute for identification of cases are necessary for enable patient treatment before progression to physical disabilities. In this sense, the present study aimed evaluate serological biomarkers contribution for early diagnosis of leprosy. Was perfomed an active case finding study in Mosqueiro district, Belém – Pará. All individuals were clinically examined by experient leprologists doctors and than 5mL of peripheral blood were colleted for future titration of anti-ND-O-BSA, anti-LID-1 e anti-NDO-LID by ELISA. The action of active finding in Mosqueiro district diagnosed 104 new cases of leprosy between 895 subjects examined (11.6%), indicating a high hidden endemy that agree with the high seroprevalence between schoolchildren. Were observed a significant difference among patients with late or early diagnoses, mainly in multibacillary forms. All biomarkers tested showed promising results in detection of late cases, such as related in literature, however, for early cases those molecules identified correctly only 50% of patients. None of biomarker tested presented sufficient sensitivity to detect all leprosy patients, early or lately diagnosed. Besides, LID-1 molecule had evidenced a lower sensitivity for early cases, their high especificity and accuracy suggest their use as a potential tool for serological screening to identify assintomatic subjects with high risk of illness. Thus, we concludes that besides no biomarker had reveled utility as a serological diagnostic tool, the detection of anti-LID-1 presented a possible aplicability as a screening marker of subjects with increased risk to develop leprosy, contributing indirectly for leprosy diagnosis.
Acesso aberto (Open Access)
Avaliação in vitro do efeito genotóxico e neurotóxico da rotenona em populações neuronais de encéfalo de ratos
(Universidade Federal do Pará, 2011-12-28) LIMA, Geovanny Braga; YAMADA, Elizabeth Sumi; http://lattes.cnpq.br/7240314827308306
Parkinson’s disease is a neurogenerative disease that affects dopaminergic neurons of the substantia nigra whose neurons Project to the striatum. Rotenone is a compound widely used as pesticide and which has been implicated among the environmental factors that increase the risk of developing PD. An essay that evaluate DNA damage, such as the eletroforesis comet essay, was introduced in the present work, to better understand the neurotoxic effects of the rotenone in a experimental model of PD. The comet assay was applied to neurons from mixed mesencephalic cultures exposed to different concentrations of rotenone in two different exposure times, 24 and 48 hours. The mean comet damage index showed a significant difference between the control condition and all the rotenone concentrations tested in both exposure times. However, in the comparative analysis considering time exposure for equivalent concentrations, there was significant difference only with 20 and 30 nM rotenone concentrations. This study demonstrated that, in the experimental conditions used, the comet assay detected damage to the genetic material without detectable alterations in the MTT viability test (5 nM rotenone, 24h), suggesting that genotoxic alterations may precede viability alterations in rotenone-exposed neurons. It is not possible, however, to assure that such alterations are irreversible or not.
Acesso aberto (Open Access)
Caracterização da resposta inflamatória e alterações neuroquímicas e eletrofisiológicas do tecido retiniano em modelo murino de malária cerebral induzido pela infecção por Plasmodium Berghei ANKA
(Universidade Federal do Pará, 2015-02-19) LEÃO, Luana Ketlen Reis; SILVA, Anderson Manoel Herculano Oliveira da; http://lattes.cnpq.br/8407177208423247; OLIVEIRA, Karen Renata Herculano Matos; http://lattes.cnpq.br/3032008039259369
Cerebral malaria (CM) is one of the most serious complications resulting from infection by P. falciparum and the leading cause of death in children. The CM frame has a complex pathogenesis associated with neurological complications arising in an enhanced immune response as well as hemorrhagic events. Studies describing retinopathy associated with the frame, together with an intense process of astrogliosis in the vicinity of retinal vessels that nourish the tissue. This paper sought to characterize the inflammatory process and the possible neurochemical and electrophysiological changes in the retinal tissue of Swiss albino mice, when inoculated with Plasmodium berghei ANKA strain (PbA). Swiss albino mice were infected with PbA strain. To characterize the above experimental cerebral malaria (ECM) was evaluated several parameters, such as onset of clinical signs, survival curves parasitemia (%) and body mass gain, vascular permeability and quantification of cytokines (TNF-α, IL-6 and IL-10) in the cortical tissue. To evaluate changes in retinal tissue functionality, use full-field electroretinography. For the evaluation of neurotransmitter systems release assay was performed and uptake of glutamate and GABA which was then quantified by High Performance Liquid Chromatography. The inflammatory response analysis was performed to quantify the cytokines (TNF-α, IL-6 and IL-10) in retinal tissue. After characterizing the MCE framework we observe a reduction in the amplitude of b-wave of rods and cones, as well as increase the implicit time of rods, mixed responses at different intensities and oscillatory potential. We observed an increase in the release and glutamate uptake and also the activation of an anti-inflammatory pathway in retinal tissue. This study allowed us to validate the murine model of MCE and characterize for the first time, changes in the retinal function accompanied by changes in the glutamatergic system as well as activation of the inflammatory pathway in retinal tissue.
Acesso aberto (Open Access)
Condicionamento físico e desempenho em testes neuropsicológicos em adultos jovens
(Universidade Federal do Pará, 2015-12-21) TOMÁS, Alessandra Mendonça; DINIZ, Cristovam Wanderley Picanço; http://lattes.cnpq.br/2014918752636286; SÓSTHENES, Márcia Consentino Kronka; http://lattes.cnpq.br/7881527576747420
Brazil is a country in demographic transition period and significantly increased population over 65 years, which requires changes in public policies for health. The early onset of specific care to young adult population with a view to successful aging may represent future reduction of public and lower incidence of diseases associated with aging expenses such as dementias. To provide grants to health policies based on evidence, this study investigated the effects of physical fitness on performance in automated neuropsychological tests selected for measurement of learning functions, visuospatial memory and language. We evaluated 109 healthy young adults of both sexes, submitted to an interview; global cognitive assessment using the Mini Mental State Examination, language tests (including verbal fluency and word list of CERAD drums) and automated neuropsychological tests (Cantab Battery); assessment of physical fitness (indirect assessment of cardiorespiratory fitness, strength of lower limbs, agility assessment, measurement surround and anthropometric indices). Based on multivariate statistics by cluster analysis (Ward method, Euclidean distance) three groups divided volunteers, matched for age and education, to make up the ANOVA criterion or the Kruskal-Wallis, in the event of samples with unequal variances. In addition, the correlation analysis was performed, principal components and discriminant analysis, which showed that the cardiorespiratory fitness was the variable that most contributed to the formation of clusters. The level of significance was set at p ≤ 0.05 values. Significant differences were found in the semantic verbal fluency tests; in physical fitness tests including resting heart rate, cardiorespiratory fitness, lower limb strength and agility assessment and neuropsychological tests of Cantab Battery (paired learning - PAL and reaction time - RTI). The correlation analysis showed only weak correlations. The results obtained in this study indicate that fitness young adult practitioners or no regular exercise cannot predict performance on neuropsychological tests. However, the fitness shown to be associated with better performance on attention tasks, visuospatial memory and learning, measured through the PAL and RTI.
Acesso aberto (Open Access)
Correlação entre parâmetros estimados pelos testes Colour Assessment and Diagnosis e Cambridge Colour Test na avaliação da discriminação de cores
(Universidade Federal do Pará, 2015-03-31) FARIAS, Letícia Miquilini de Arruda; SOUZA, Givago da Silva; http://lattes.cnpq.br/5705421011644718
The Colour Assessment and Diagnosis (CAD) and Cambridge Colour Test (CCT) tests are widely used in basic and clinic researches, because of high sensibility and specificity of your results. These tests use distinct paradigms of stimulation to estimate the color discrimination thresholds. It is not well known about the relationship of results of each paradigm in the evaluation of color discrimination in these tests. So, the present study aimed to compare the parameters of evaluation of color discrimination estimated from CAD and CCT tests. Fifty-nine trichromat subjects and thirty eight subjects with congenital dyschromatopsia (16 protans, 22 deutans) with mean age of 26,32 ±8,9 years-old were evaluated. 66 subjects were tested in CAD and CCT tests, 29 subjects in the CAD test and 2 subjects in the CCT test. The color vision phenotype of all subjects was determined through a battery of psychophysical tests and the estimative of color discrimination thresholds was evaluated by CAD and CCT tests. The data of color discrimination thresholds was fitted ellipses. The criteria analyzed to each subject were: area of the ellipses, angle of rotation of the ellipses and size of protan, deutan and tritan vectors. For each one of parameters was realized: descriptive statistic, analysis of dispersion of parameters between CAD e CCT tests and the combination of these parameters in each test, ratio between the parameters, correlation of parameters to three mathematical models and analysis of agreement. The parameters of area and size of deutan and tritan vectors of trichromat subgroup, area and size of tritan vector of protan subgroup, and size of protan and tritan vectors of deutan subgroup exhibited equivalence between the results of both tests. The parameters of area, angle of rotation and size of protan and tritan vectors showed agreement of measures between your results. Factors as the distincts localizations of neutral points of CAD and CCT tests and the spatial arrangement of the vectors in the CIE 1976 color space in the CCT test may have influenced the determination of chromatic discrimination thresholds of both tests. Despite using distinct paradigms in configuration of stimulation, the tests CAD and CCT are comparable.
Acesso aberto (Open Access)
Detecção molecular e sorológica da infecção por Mycobacterium Leprae em casos e comunicantes de hanseníase e escolares de Oriximiná (PA)
(Universidade Federal do Pará, 2011-05-23) FERREIRA, Denis Vieira Gomes; SALGADO, Claudio Guedes; http://lattes.cnpq.br/2310734509396125
Leprosy is a chronic infectious disease that primarily affects skin and peripheral nerves and its clinical signs are lesions with abnormal pigmentation and sensitivity. Its etiologic agent is Mycobacterium leprae, an obligate intracellular bacillus, acid fast rod-shaped straight or slightly curved. The transmission occurs through the upper airway, and the default host immune ranges from a high cell-mediated immune response, known as Th1 response, a high susceptibility to infection with high humoral immune response, Th2 response. This study aimed to examine clinical and socio-epidemiological information to correlate with levels of IgM anti-PGL-1 in plasma, and molecular detection of M. leprae in nasal swabs from cases and contacts of leprosy between 2004 and 2008, and schoolchildren from public schools in the city of Oriximiná Para. The results show that: 1) leprosy patients have poor housing and food, with almost 50% of food deprivation, 2) approximately 45% of clinically healthy presents IgM anti-PGL-1 positive, regardless of age, period of living with index cases or the presence or absence of a BCG scar and 3) the DNA of M. leprae is found in 15- 30% of cases and contacts, and only 1.6% of students did not show correlation with ELISA IgM anti-PGL-1, with the clinical form of the disease or the duration of the leprosy patients treated with MDT in the 5 years before data collection. Thus, the positivity of ELISA IgM anti-PGL-1 seems to indicate the magnitude of the exposure of a population to M. leprae, which may contribute to epidemiological studies and the definition of priority population groups to conduct active case finding of leprosy in a given community.
Acesso aberto (Open Access)
Efeito protetor da ração enriquecida com açaí (Euterpe oleracea) no quadro de malária cerebral experimental
(Universidade Federal do Pará, 2018-05-17) TORRES, Marjorie Lujan Marques; OLIVEIRA, Karen Renata Herculano Matos; http://lattes.cnpq.br/3032008039259369; BATISTA, Evander de Jesus Oliveira; http://lattes.cnpq.br/2206444845201080
Cerebral malaria (CM) is one of the most severe complications attributed to protozoal infection by Plasmodium falciparum, gaining prominence in infant mortality rates in endemic areas. It´s a complex pathogenesis and still little elucidated, being associated with cognitive, behavioral and motor changes. Aiming to broaden the knowledge about this pathology and looking for the benefits attributed to the daily consumption of antioxidants, the objective of this work is to evaluate the possible protective effect of Euterpe oleracea fruit (açaí) during evolution of experimental cerebral malaria (ECM) induced in murine model by means of inoculation of Plasmodium berghei (PbA), ANKA stain. For this, we used the Swiss line, which were inoculated intraperitoneally (i.p.) with 10⁶ of parasited erythrocytes. The animals (females and males between 4 and 6 weeks) were divided into four groups, among which Açaí and PbA+Açaí groups were maintained on a ration-exclusive diet enriched with açaí and the Control and PbA groups were given only standard ration during 22 days of experiment. To characterize the ECM framework, several parameters were evaluated such as the appearence of clinical signs, survival curve, parasitemia, body mass gain and vascular permeability. The SHIRPA protocol was used to evaluate the behavioral and locomotor changes in animals. We observed an extension of survival of the infected animals and treated with a diet enriched with acai berry, and decreased the neurological changes arising from the exposure of the cerebral parenchyma. This work allowed us to validate the development of the experimental brain malaria framework in murine model and evaluate the neuroprotective effect of Acai (Euterpe oleracea) in the course of the disease.
Acesso aberto (Open Access)
Efeitos do exercício voluntario na recuperação de hemissecção da medula espinhal: mudanças na rede perineuronal e acetilação de histonas
(Universidade Federal do Pará, 2014-03-31) SFAIR, Márcio José Teixeira; BAHIA, Carlomagno Pacheco; http://lattes.cnpq.br/0910507988777644; PEREIRA JÚNIOR, Antônio
Regular physical exercise prevents and combats various diseases over time, especially as a great therapeutic tool for the treatment of lesions in the central nervous system (CNS). After transection (complete or incomplete / hemisection) spinal cord reactive glial cells secrete substances inhibitory to axonal regeneration , for example , molecules of chondroitin sulfate proteoglycans (PGSCs) that play an important role in the formation of a physical barrier chemical , called glial scar, which prevents the growth of axons damaged by injury. Research involving experimental model of spinal cord injury and rehabilitation by exercise have obtained promising results. However, the physiological and molecular mechanisms by which promote these positive results are still poorly understood. The objective of this study was to analyze the recovery of motor function of the hind paw after voluntary exercise protocol in an experimental model of spinal cord hemisection and investigate two molecular mechanisms involved in functional recovery: the degradation of the PGSCs Perineuronal networks and histone acetylation. To do this, twenty-four (24) male Wistar rats (Rattus norvegicus) mice were used and divided into 3 groups (control, trained and untrained). Except for the control group, all animals were accustomed to racing wheels and followed underwent an experimental surgery hemisection of the spinal cord at the time of the 8th thoracic vertebra. Our results showed that voluntary exercise on wheels racing after experimental spinal cord injury promoted recovery of motor function of the affected hind paw, but did not observe qualitative differences in histone acetylation and degradation PGSCs between groups.
Acesso aberto (Open Access)
Efeitos do fator de crescimento do nervo sobre os níveis extracelulares de glutamato e compostos tióis na retina embrionária de galinha
(Universidade Federal do Pará, 2011-04-20) GARCIA, Tarcyane Barata; SILVA, Anderson Manoel Herculano Oliveira da; http://lattes.cnpq.br/8407177208423247
Nerve growth factor (NGF) belongs to the neurotrophin family and induces its effects through activation of two distinct receptor types. NGF was first described by Rita Levi-Montalcini and collaborators as an important factor involved in nerve differentiation and survival. Another role for NGF has been established in neurotransmitter release in the hippocampus, developing visual cortex and cerebellar neuron. However, this phenomenon has not been demonstrated in retina to date. We therefore investigated whether NGF can modulate the glutamate release in the retinal tissue at its peak of the neurotrophic activity (E10-E12). In addition this, we aimed to study the mechanisms of this effect about its dependence on extracellular Ca2+ and participation of Na+-dependent and Na+-independent glutamate transporters. Since high levels of glutamate signalization have been implicated in the oxidative stress, we also investigated the effects of NGF on the thiols compounds. We used intact retinal tissue from chicken embryos (E11) incubated with NGF (10, 50, 100 ng/ml) for different periods (15, 30, 45, 60, 120 min). Extracellular glutamate and thiols content was measured by HPLC methods and colorimetric assay, respectively. We found that NGF rapidly enhances the release of basal glutamate and it can induce thiol release in a more prolonged time of incubation, as well. Interestingly, the NGF-induced increase in the extracellular levels of glutamate was blocked by Ca2+-free medium only in retina treated for 15 min. Retina incubated for 30 min showed a non-vesicular NGF-induced glutamate release. Since glutamate and thiol release was not blocked by Zn2+, we suggested the possible involvement of system Xc- in both processes.NGF-induced increase in the extracellular thiol could be an important protective mechanism enabling retinal neurons to maintain their redox status during development.
Acesso aberto (Open Access)
Entropia conjunta de espaço e reqüência espacial estimada através da discriminação de estímulos espaciais com luminância e cromaticidade moduladas por funções de Gábor: implicações para o processamento paralelo de informação no sistema visual humano
(Universidade Federal do Pará, 2013-12-06) SILVEIRA, Vladímir de Aquino; SOUZA, Givago da Silva; http://lattes.cnpq.br/5705421011644718
The objective of this study was to estimate the joint entropy of the human visual system in the domains of space and spatial frequency by using psychometric functions. The psychometric functions were obtained from stimulus discrimination that had luminance or chromaticity modulated by Gábor functions. The method consisted in evaluating the entropy in the space domain by testing subject capacity to discriminate stimuli that differed only in their spatial extent and in evaluating the entropy in the spatial frequency domain by testing subject capacity to discriminate stimuli that differed only in their spatial frequency. The joint entropy was then estimated from these two individual entropy values. Three visual conditions were studied: achromatic, chromatic without fine tuning correction of equiluminance, and chromatic with full equiluminance correction by using heterochromatic flickker photometry. Four subjects were tested in all conditions, two additional subjects were tested in the chromatic condition without fine equiluminance adjustment and a seventh subject also performed the acrhomatic test. All subjects were examined by an ophthalmologist, their eyes and visual system were considered normals, and presented no report, symptoms or signs of visual dysfunctions or diseases that could have affected their visual system. The subjects had their normal or corrected visual acuity of 20/30 minimum. The work was approved by the Comissão de Ética em Pesquisa (Núcleo de Medicina Tropical, UFPA) and followed the recomendations of the Helsinki Declaration. The Gábor functions used for luminance or chromaticity modulation comprised unidimensional horizontal sinusoidal gratings, modulated in the vertical direction, with bidimensional Gaussian envelopes whose spatial extent was measured by their standard deviation. Stimuli were generated by using a software written in Pascal in a Delphi 7 Enterprise environment. A Dell Precision 390 Workstation was used together with a CRS VSG ViSaGe stimulus generator to display the stimuli in a CRT monitor, 20”, 800 x 600 pixels, 120 Hz, RGB, Mitsubishi Diamond Pro 2070SB. In the achromatic experiments, the stimuli were generated by white luminance modulation (CIE1931: x = 0.270, y = 0.280; CIE1976: u’ = 0.186, v’ = 0.433), 44,5 cd/m2 mean luminance. In the chromatic experiments, mean luminance was kept in 15 cd/m2, and two series of red-green stimuli were used. In the first series, two chromaticities defined on the M-L axes of the DKL color space were used (CIE1976: green, u’=0.131, v’=0.380; red, u’=0.216, v’=0.371). In the second series, two chromaticities were defined along a red-green horizontal axis across the CIE1976 color space (CIE1976: green, u’=0.150, v’=0.480; red, u’=0.255, v’=0.480). Throughout the experiment, the reference stimuli comprised gratings with three different spatial frequencies (0.4, 2, and 10 cycles per degree) and a Gaussian envelope with 1 degree standard deviation. The test stimuli comprised 19 different spatial frequencies in the region of the reference spatial frequency and 21 different Gaussian envelopes in the region of the reference standard deviation. In the achromatic condition, four levels of Michelson contrast were studied: 2%, 5%, 10% e 100%. In the two chromatic conditions, the highest level of pooled cone contrast allowed by the CRT gamut was used, 17%. The procedure consisted of a two interval forced choice with the following steps: i) 1 s display of the reference stimulus; ii) 1 s replacement of the reference stimulus by a background with the same luminance and chromaticity; iii) 1 s display of the test stimulus which differed from the reference stimulus either in spatial frequency or spatial extent, together with a beep to tell the subject that it was now neccessary to provide a response if the two stimuli were equal or different; iv) replacement of the test stimulus by the background. The spatial extent or spatial frequency of the test stimulus was randomly changed from trial to trial by usind the method of constant stimuli. In a series comprising 300 trials, the spatial frequency was changed while in another series also comprising 300 trials, the spatial extent was changed, each test stimulus in each series being displayed at least 10 times. The subject response in every trial was stored as correct or incorrect for further use to estimate the psychometric function. The experimental data of the psychometric functions for spatial extent and spatial frequency at each contrast level, which corresponded to percent of correct responses, were fitted with Gaussian functions using the Least Square Method. For each contrast level, the spatial extent entropy and spatial frequency entropy were estimated from the standard deviations of these Gaussian functions. The joint entropy was then calculated by multiplying the square root of the spatial extent entropy by the spatial frequency entropy. The joint entropy values were compared with the theoretical minimum predicted for linear systems, 1/4π or 0.0796. For low and intermediate spatial frequencies at high contrasts, the joint entropy reached very low levels, below this minimum, suggesting that there were nonlinear interactions between two or more visual mechanisms. This phenomenon occurred in all conditions (achromatic, chromatic, and chromatic with fine equiluminance adjustment) and was more pronounced for spatial frequency 0.4 cycles / degree. A possible explanation for this phenomenon is the occurrence of nonlinear interactions between the retino-geniculo-striate visual pathways, such as the K, M, and P pathways, in the primary visual area or in higher levels of neural processing of visual information.
Acesso aberto (Open Access)
Estudos citogenéticos em roedores do gênero oecomys (rodentia: cricetidae)
(Universidade Federal do Pará, 2011-04-29) ROSA, Celina Coelho da; NAGAMACHI, Cleusa Yoshiko; http://lattes.cnpq.br/8887641213110093
The rodents are one of the most diversified groups of living mammals and also have a large range of ecological adaptations. The rodents, because of yours population characteristics, developed as the most specious group of mammals in Neotropical forests and one of the most interesting for studies of genetic variation and evolution among vertebrates. The genus Oecomys (Sigmodontinae) comprises approximately 16 species that inhabit tropical and subtropical forests in Central and South America. Six of these species are expected to occur in eastern Brasilian Amazon. In literature, the genus Oecomys has a large karyotypic variation, where the diploid number ranges from 58 to 86. In this study specimens of Oecomys paricola Thomas, 1904 from Belém and Marajó Island, northern Brazil, were investigated using cytogenetic, molecular and morphological analyses. Three karyotypes were found, two from Belém (2n=68, FN=72 and 2n=70, FN=76) and a third from Marajó Island (2n=70, FN=72). No molecular or morphological differences were found between the individuals with differing cytotypes from Belém and Marajó Island. Specimens from the Belém City region may represent two cryptic species because two different karyotypes are present in the absence of significant differences in morphology and molecular characteristics. The Marajó Island and Belém populations represent distinct species that have been separated for some time, and are in the process of morphological and molecular differentiation as a consequence of reproductive isolation at the geographic and chromosomal levels.
Acesso aberto (Open Access)
Influência da atividade mastigatória e do ambiente sobre o aprendizado espacial e o padrão da atividade exploratória em modelo murinho senil
(Universidade Federal do Pará, 2014-04-01) MENDES, Fabíola de Carvalho Chaves de Siqueira; DINIZ, Cristovam Wanderley Picanço; http://lattes.cnpq.br/2014918752636286; SÓSTHENES, Márcia Consentino Kronka; http://lattes.cnpq.br/7881527576747420
To measure possible influences of the mastication and sedentary lifestyle, we imposed masticatory patterns with three different experimental diet regimes starting at 21st postnatal day during 6 (6M) or 18 (18M) months: continuous pellet hard diet, equal periods of hard followed by soft diet or equal periods of hard followed by soft followed by hard diet. To mimic the sedentary and active lifestyles, the animals were raised, respectively in standard (AP) or enriched cages (AE). To measure the effects of diet, environment and age on the exploratory activity, we performed the open field test. Young mice (AP) with altered masticatory activity demonstrated more preference for peripheric zone, but in aging and AE animals these differences were minimized. In the aging specimens maintained in AE, these differences were reappeared. About influences on learning and spatial memory, we apply the Morris water maze and the reduced masticatory activity, regardless of the environment, decreased the average rate of spatial learning and rehabilitation recovered the losses associated in young animals and the association with AE improved the learning rate in old mice. No significant correlations were observed between swimming speed and learning rate. We conclude that the change in masticatory activity influences the pattern of exploration by zones in the open field and environmental stimulation enhances the effects of aging, emphasizing the preference for peripheric zone and reduced masticatory activity impairs spatial memory during the test of the Morris water maze and rehabilitation is able to recover spatial ability. Here, the combination with AE is required in aging.