Navegando por Orientadores "ROCHA, Fernando Allan de Farias"
Agora exibindo 1 - 6 de 6
- Resultados por página
- Opções de Ordenação
Item Acesso aberto (Open Access) Análise morfológica e topográfica das células ganglionares da retina do caititu (Tayassu tajacu)(Universidade Federal do Pará, 2014-12-22) COSTA, Kelly Helorany Alves; ROCHA, Fernando Allan de Farias; http://lattes.cnpq.br/3882851981484245In the Amazon there are several different wild animals species, becoming this way a good environment to investigated about compared physiology. Among this species, the caititu, Tayassu tajacu, stood out. This animals is located in central America and Latin America. There are many publications around morphology of sexual organs, meat and blood of the catitu. Although, regarding studies about visual’s morphology are scarce. Facing this reality, the present study investigated a morphology and topography of ganglion cells of Tayassu tajacu’s retina. Were used six retina, from eight animals, Both sexes of the species Tayassu tajacu. The caititu born and raised in captivity in the Brazilian company of research known as Embrapa/Pará. Were slaughtered according to the rules of animals ‘s management to subsequent removal and attachment of eyes. The retinas were dissected and stained using Nissl technique to ganglion cells of view, displaced amacrine, red blood cells, microglia cells and components of vascularization. A count of ganglion cells was made a long the horizontal and vertical axis. Being the number of ganglion cells by field converted into density values. The different regions of the retina were analyzed as the cellular density, obtaining the medium value of the density 351,822 ± 31,434 CG/mm². Verified different of the density between the studies regions : The dorsal region had a medium density and standard deviation 894 ± 44 CG/mm², the ventral region 894 ± 1 CG/mm²; the nasal region 1.403 ± 43; the temporal region with 1596 ± 251. The average peak density located approximately 3.13 mm from the dorsal direction and 6.77 mm in the temporal direction of the optic nerve, was 6767 GC / mm². Check there are two specialized regions, the visual streak region and the area temporalis. The visual streak located in the horizontal direction of the nasal region to temporal, presenting higher cellular density, possibly providing better panoramic vision from the environment and detecting the objects in the horizontal direction. Already the temporalis area, located within the visual range, provides increased visual acuity and spatial resolution, the environment that they live. These results allow to start comparisons between morphophysiological the retina of peccaries with other animal species.Item Acesso aberto (Open Access) Avaliação comportamental e eletrofisiológica do sistema visual em camundongos com anemia a partir de um modelo de colite aguda(Universidade Federal do Pará, 2017-01-31) GOMES, Luana Aparecida Silva; GOULART, Paulo Roney Kilpp; http://lattes.cnpq.br/7800966999068746; ROCHA, Fernando Allan de Farias; http://lattes.cnpq.br/3882851981484245; https://orcid.org/0000-0002-6148-1050Inflammatory bowel diseases (IBD) are the main causes of anemia and iron deficiency and tend to affect metabolically active tissues distant from the inflammation areas, such as the retina. From this context, it is interesting to investigate the responsive behavior of the visual system through psychophysical and electrophysiological tests in animals with IBD. The main objective of the present work was to evaluate the behavioral and physiological changes of the visual system in mice with induced anemia, from an acute colitis model. For this purpose, 18 mice were used, divided into three groups: control; Colitis (induced by Dextran Sulfate Sodium (DSS), and colitis mother (animals born from mothers with induced colitis). Induction with DSS was performed 6 days before the tests, which occurred in the period between 60 and 90 days of life of the subjects. After induction, the electrophysiological responses were collected using the full field electroretinogram as an electrophysiological measure. Scotopic responses (rods, mixed 1 and mixed 2) and photoptic responses (from cones 1 Hz, S cones and flicker at 12, 18, 24 and 30 Hz) were measured. In addition, behavioral tests were performed by training with drinking fountain and evaluation of the perception of contrast, through stimulation with sinusoidal grids, arranged in different frequencies. Statistical analysis was performed with one-way ANOVA test, using Tukey post- test, considering (P <0.05) as significant. It was found a reduction in the response amplitudes in microvolts (μV) at 60 days in the following responses: b-wave of mixed 1 (colitis: 28.12 and ± 7.96, mother colitis 42.180 And ± 8,525), cone wave 1 Hz (colitis 39.85 and ± 12.74); Cones S (colitis 36.64 and ± 9.09 μV); 18 Hz Flicker (colitis: 25.12 ± 5.62, mother colitis: 38.37 ± 7.1); 24 hr (colitis: 22.46 ± 8.38, mother colitis: 29.41 ± 9.676) and 30 Hz (colitis: 14.4 ± 3.25, mother colitis: 27.13 ± 5.51). At 90 days, reduction in the b wave of rods (colitis: 57.06 ± 6.7), mixed 1 (colitis: 45.69 ± 7.86 and mother colitis: 56.03 ± 17.130), wave ‘a’ of photopic responses (Colitis, 25.1 ± 5.11) and cones S (colitis 31.04 ± 4.83), Flicker 18 Hz (colitis 29.1 ± 9.01) and Flicker 30 Hz (colitis: 41, 8 ± 5.09, mother colitis: 32.72 ± 11.4). There was an increase in implicit time in miliseconds (ms) in rods (colitis 24.68 ± 3.48 ms) and Flicker response of 12 Hz (colitis: 21.69 ± 4.65, mother colitis 22.14 ± 4.42) At 60 days. E cone S (colitis 13.35 ± 1.18) and Flicker 24Hz (mother colitis 28.4 ± 3.87) at 90 days. The behavioral tests showed a decrease in the responses of the colitis group and a delay in the learning on bar pressure response in comparison to the control group. Therefore, anemia impairs scotopic and photopic visual function, affecting rodent retinal cells with anemia and maternal anemia, as well entails in difficulties performing a behavioral learning task in the training performed at the operant conditioning box.Item Acesso aberto (Open Access) Avaliação eletrorretinográfica de ratos wistar jovens submetidos à tireoidectomia bilateral(Universidade Federal do Pará, 2012-10-31) RODRIGUES, Keuri Eleutério; ROCHA, Fernando Allan de Farias; http://lattes.cnpq.br/3882851981484245The thyroid synthesizes thyroxine (T4) and 3,5,3 '-triiodothyronine (T3), both hormones have a crucial role in the development of the central nervous system, including the retina and visual system. The decrease in blood levels of T3 and T4 causes a syndrome called hypothyroidism, which may lead to visual impairment. The visual deficits generated by hypothyroidism are directly related to the development period of the individual. It has been demonstrated in murine models that congenital hypothyroidism decreases the retinal thickness, the number of cells and interferes with the differentiation of M cones. Here, we investigated the possible functional changes in juvenile rat’s retina after bilateral thyroidectomy using noninvasive electrophysiological responses. Therefore, we divided the rats into three groups (control, sham and thyreoidectomized) each containing n≥8 animals. The surgeries were performed 30 days post-natal and the full-field electroretinogram (ERG) were performed 10, 15, 20, 25 and 30 days after surgery, using standard protocols for assessing the scotopic response maximum, photopic response (with and without the use of light filters) and response to flicker (12, 15, 18 and 30 Hz). The parameters analyzed were implicit time and amplitude of a- and b-waves of ERG. We also perform monitoring of clinical parameters of animals in order to identify characteristics that indicate a hypothyroidism, as well as the dosage of thyroid hormones. The results showed that there was a decrease in the a- and b-waves amplitudes in thyroidectomy animals (10, 15, 20, 25 and 30 days after surgery), compared to control and sham animals at all the stimulation protocols used in ERG. The results of the evaluation of the implicit time for both waves showed none statistical difference when comparing to control and sham groups. Also we observed a reduction in size and weight of thyroidectomy animals, associated with reduced levels of thyroid hormone (T3). Thus we concluded that the thyroid hormones are directly related to functional changes in the retina of thyroidectomy animals, together with the reduction of weight and size.Item Acesso aberto (Open Access) Avaliação neuropsicológica de deficits cognitivos em pessoas vivendo com HIV (PVHIV)(Universidade Federal do Pará, 2024-08) GONÇALVES, Samilly Palheta; RODRIGUES, Anderson Raiol; ROCHA, Fernando Allan de Farias; http://lattes.cnpq.br/3882851981484245; https://orcid.org/0000-0002-6148-1050The introduction of antiretroviral therapy resulted in a reduction in opportunistic infections associated with HIV, consequently reducing the incidence of most neurological diseases in HIV-positive patients. However, neurocognitive changes associated with HIV (HAND) remain at a significant prevalence, even in individuals using antiretroviral drugs. The present study aimed to evaluate possible cognitive deficits in HIV-positive patients and characterize the clinical profile of neurocognitive manifestations in the Northern region of Brazil. 30 HIVpositive patients were evaluated, treated at the Health Care Center for Acquired Infectious Diseases (CASA DIA), in Belém do Pará. It was possible to verify a decline in neurological functions, which affect the functional capacity of these PLHIV, with emphasis on the cognitive domain of memory and attention, where it was possible to identify through IADLs, IHDS and CANTAB.Item Acesso aberto (Open Access) Eletrofisiologia da visão em modelo experimental de ratos com diabetes e hipotireoidismo(Universidade Federal do Pará, 2014-03-28) GUIMARÃES, Glenda Figueira; GOMES, Bruno Duarte; http://lattes.cnpq.br/4932238030330851; ROCHA, Fernando Allan de Farias; http://lattes.cnpq.br/3882851981484245Diabetes mellitus is a worldwide public health problem because of its potential morbidity and mortality. This pathology is characterized as a metabolic disorder with chronic hyperglycemia, results from an absolute or relative deficiency in the secretion and/or insulin action. Associated to this case, problems with the thyroid are often found in patients with diabetes, especially with advancing age. Furthermore, there is a body of knowledge describing that both diabetes and hypothyroidism cause visual loss, however, there are not many publications on the physiology involving both pathologies in conjunction with the visual complications. Therefore, this work aimed to investigate issues relevant to a more detailed understanding of the framework for the evolution of retinal impairment in animal models simultaneously affected by two diseases: diabetes and hypothyroidism. For this, 50 male Wistar rats (Rattus norvegicus) were used, two-months-old, weighing between 80 to 120 grams, divided into four groups: a control group without procedures; a group with hypothyroidism opting for a bilateral experimental model of thyroidectomy; a group with diabetes, with application of 200 mg/kg to 2% Aloxana; and two groups with both pathologies, adopting both experimental procedures by changing the sequence of the pathologies in question. In the studied groups, it was used the electroretinogram (ERG), a non-invasive method widely used in academia to evaluate the visual changes, in different periods of 30, 45 and 60 days. We found a decrease in the average amplitude of the wave-a of the animals in the groups with diabetes and with both pathologies in all the realized registrations, the ones that showed the highest statistical differences were in relation to the registration of maximum estocópica, as well as difference in oscillatory potential of both groups with both pathologies. These results support the hypothesis that both concomitant pathologies (diabetes and hypothyroidism) significantly diminish the ERG responses.Item Acesso aberto (Open Access) Investigação do efeito ictiotóxico do extrato etanólico da raíz de Spilanthes acmella (jambú) em zebrafish através da análise eletrofisiológica e comportamental(Universidade Federal do Pará, 2013-12-09) RIBEIRO, Layza Costa; ROCHA, Fernando Allan de Farias; http://lattes.cnpq.br/3882851981484245Among the various species of medicinal plants, we can find the Spilanthes acmella species, popularly known as Jambu that stands out due to its numerous applications in the folk medicine field. Traditional medicine recommends the use of its leaves and flowers in the preparation of infusions to treat anemia, dyspepsia, malaria, mouth diseases (tooth pain) and throat diseases, against scurvy and also as antibiotic and anesthetic, being its main effects attributed to espilantol, which is an important representative of the substances present in these plants. Some studies have been performed using the espilantol, providing some information of the effect of this substance, as its immunomodulatory effect and because of its functional interaction with monocytes, granulocytes and killer cells. However, there are still no electrophysiological studies about its ictiotoxic action using, for example, the EEG to demonstrate its action at the central nervous system level or electromyogram to verify the occurrence of their effects in the Zebrafish muscles, evoking the need for this research. Based on this, the present study aimed to investigate the ictiotoxic action of the ethanol extract of the Spilanthes acmella root in Zebrafish by electrophysiological and behavioral analysis. The results showed that the ethanol extract of Spilanthes acmella is a potent inducer of central excitability in zebrafish, this being evidenced by changes in electrical activity patterns seen in the EEG of the animals subjected to the extract and by increasing brain activity seen in the spectrogram. The extract also caused changes, in a lesser extent, on the electromyographic tracings of zebrafish subjected to the same concentration of the extract, with the appearance of scattered muscle contractions and brief myoclonus. And the behavioral findings from the delimitation of three stages of behavior, which began with the increased excitability of the animal and resulted in the seizure and death of the fish, served to corroborate the electrophysiological findings that the ethanol extract of Spilanthesacmella acts as a potent substance acting on the nervous system of zebrafish, with convulsant activity.