RESUMO
The need to fully exploit fishing resources due to increasing production and consequent waste generation requires research to promote the sustainability of the fishing industry. Fish waste from the industry is responsible for relevant environmental contamination. However, these raw materials contain high amounts of collagen and other biomolecules, being attractive due to their industrial and biotechnological applicability. Thus, to reduce the waste from pirarucu (Arapaima gigas) processing, this study aimed to obtain collagen from pirarucu skin tissue. The extraction process used 0.05 M sodium hydroxide, 10% butyl alcohol, and 0.5 M acetic acid, with extraction temperature of 20°C. The obtained yield was 27.8%, and through sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), it was determined that the collagen obtained was type I. This study showed that collagen solubility was highest at pH 3 and the lowest solubility was at concentrations of 3% sodium chloride. The denaturation temperature of collagen was 38.1°C, and its intact molecular structure was observed using the Fourier transform infrared spectrophotometry technique with an absorption radius of 1. The results showed that it was possible to obtain collagen from pirarucu skin at 20°C, which has the typical characteristics of commercial type I collagen. In conclusion, the procedures used may be considered to be an interesting alternative for collagen extraction, a new product obtained from the processing of fish waste.
Assuntos
Colágeno , Proteínas de Peixes , Animais , Proteínas de Peixes/análise , Proteínas de Peixes/química , Colágeno Tipo I , Pele/química , Peixes , Água DoceRESUMO
The need to fully exploit fishing resources due to increasing production and consequent waste generation requires research to promote the sustainability of the fishing industry. Fish waste from the industry is responsible for relevant environmental contamination. However, these raw materials contain high amounts of collagen and other biomolecules, being attractive due to their industrial and biotechnological applicability. Thus, to reduce the waste from pirarucu (Arapaima gigas) processing, this study aimed to obtain collagen from pirarucu skin tissue. The extraction process used 0.05 M sodium hydroxide, 10% butyl alcohol, and 0.5 M acetic acid, with extraction temperature of 20°C. The obtained yield was 27.8%, and through sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), it was determined that the collagen obtained was type I. This study showed that collagen solubility was highest at pH 3 and the lowest solubility was at concentrations of 3% sodium chloride. The denaturation temperature of collagen was 38.1°C, and its intact molecular structure was observed using the Fourier transform infrared spectrophotometry technique with an absorption radius of 1. The results showed that it was possible to obtain collagen from pirarucu skin at 20°C, which has the typical characteristics of commercial type I collagen. In conclusion, the procedures used may be considered to be an interesting alternative for collagen extraction, a new product obtained from the processing of fish waste.
RESUMO
Research in fear conditioning has provided a comprehensive picture of the neuronal circuit underlying the formation of fear memories. In contrast, our understanding of the retrieval of fear memories is much more limited. This disparity may stem from the fact that fear memories are not rigid, but reorganize over time. To bring some clarity and raise awareness about the time-dependent dynamics of retrieval circuits, we review current evidence on the neuronal circuitry participating in fear memory retrieval at both early and late time points following auditory fear conditioning. We focus on the temporal recruitment of the paraventricular nucleus of the thalamus (PVT) for the retrieval and maintenance of fear memories. Finally, we speculate as to why retrieval circuits change with time, and consider the functional strategy of recruiting structures not previously considered as part of the retrieval circuit.
Assuntos
Medo/fisiologia , Memória de Longo Prazo/fisiologia , Tonsila do Cerebelo/metabolismo , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Núcleo Central da Amígdala/fisiologia , Condicionamento Clássico/fisiologia , Humanos , Memória/fisiologia , Núcleos da Linha Média do Tálamo/fisiologia , Vias Neurais/fisiologia , Tálamo/fisiologiaRESUMO
The aim of this study was to investigate the influence of image resolution manipulation on the photogrammetric measurement of the rearfoot static angle. The study design was that of a reliability study. We evaluated 19 healthy young adults (11 females and 8 males). The photographs were taken at 1536 pixels in the greatest dimension, resized into four different resolutions (1200, 768, 600, 384 pixels) and analyzed by three equally trained examiners on a 96-pixels per inch (ppi) screen. An experienced physiotherapist marked the anatomic landmarks of rearfoot static angles on two occasions within a 1-week interval. Three different examiners had marked angles on digital pictures. The systematic error and the smallest detectable difference were calculated from the angle values between the image resolutions and times of evaluation. Different resolutions were compared by analysis of variance. Inter- and intra-examiner reliability was calculated by intra-class correlation coefficients (ICC). The rearfoot static angles obtained by the examiners in each resolution were not different (P > 0.05); however, the higher the image resolution the better the inter-examiner reliability. The intra-examiner reliability (within a 1-week interval) was considered to be unacceptable for all image resolutions (ICC range: 0.08-0.52). The whole body image of an adult with a minimum size of 768 pixels analyzed on a 96-ppi screen can provide very good inter-examiner reliability for photogrammetric measurements of rearfoot static angles (ICC range: 0.85-0.92), although the intra-examiner reliability within each resolution was not acceptable. Therefore, this method is not a proper tool for follow-up evaluations of patients within a therapeutic protocol.
Assuntos
Adulto , Feminino , Humanos , Masculino , Pé/anatomia & histologia , Pé/fisiologia , Variações Dependentes do Observador , Fotogrametria , Valores de Referência , Reprodutibilidade dos TestesRESUMO
The aim of this study was to investigate the influence of image resolution manipulation on the photogrammetric measurement of the rearfoot static angle. The study design was that of a reliability study. We evaluated 19 healthy young adults (11 females and 8 males). The photographs were taken at 1536 pixels in the greatest dimension, resized into four different resolutions (1200, 768, 600, 384 pixels) and analyzed by three equally trained examiners on a 96-pixels per inch (ppi) screen. An experienced physiotherapist marked the anatomic landmarks of rearfoot static angles on two occasions within a 1-week interval. Three different examiners had marked angles on digital pictures. The systematic error and the smallest detectable difference were calculated from the angle values between the image resolutions and times of evaluation. Different resolutions were compared by analysis of variance. Inter- and intra-examiner reliability was calculated by intra-class correlation coefficients (ICC). The rearfoot static angles obtained by the examiners in each resolution were not different (P > 0.05); however, the higher the image resolution the better the inter-examiner reliability. The intra-examiner reliability (within a 1-week interval) was considered to be unacceptable for all image resolutions (ICC range: 0.08-0.52). The whole body image of an adult with a minimum size of 768 pixels analyzed on a 96-ppi screen can provide very good inter-examiner reliability for photogrammetric measurements of rearfoot static angles (ICC range: 0.85-0.92), although the intra-examiner reliability within each resolution was not acceptable. Therefore, this method is not a proper tool for follow-up evaluations of patients within a therapeutic protocol.
Assuntos
Pé/anatomia & histologia , Adulto , Feminino , Pé/fisiologia , Humanos , Masculino , Variações Dependentes do Observador , Fotogrametria , Valores de Referência , Reprodutibilidade dos TestesRESUMO
The prelimbic (PL) subregion of medial prefrontal cortex has been implicated in anxiety regulation. It is unknown, however, whether PL cortex also serves to fine-tuning the level of anxiety-related behavior exhibited on the next exposure to the same potentially threatening situation. To address this, we infused cobalt (1.0 mM) to temporarily inactivate the PL cortex during testing, post-testing or retesting in the elevated plus-maze (EPM). This protocol was chosen because it allowed us to concurrently investigate anxiety and the process of aversive learning and memory. PL cortex inactivation during the EPM testing increased the exploration of open-arms, substantiating its role in anxiety. PL cortex inactivation during the EPM retesting counteracted the further avoidance to open-arms exhibited by rats. Interestingly, as evidenced by min-by-min analysis, the cobalt-treated group behaved on EPM retesting as did the vehicle-treated group on EPM testing. This result may imply that activity in PL cortex is necessary for retrieving previously learned information that adjusts the anxiety response level on EPM retesting. Alternatively, a simple reduction in anxiety could explain the cobalt-induced increase in retest open-arms exploration. Neither test nor post-test PL cortex inactivation affected the further avoidance to open-arms observed on EPM retesting. To extend the investigation of PL cortex role in the regulation of open-arms avoidance, we infused other drugs prior to testing or retesting in the EPM. Antagonism of PL cortex adrenergic beta-1 receptors with atenolol (10 nmol), cholinergic muscarinic receptors with scopolamine (20 nmol) or glutamatergic N-methyl-d-aspartic acid (NMDA) receptors with AP5 (6.0 nmol) interfered with the level of open-arms exploration on testing, but not on retesting.
Assuntos
Ansiedade/metabolismo , Sistema Límbico , Aprendizagem em Labirinto/fisiologia , Córtex Pré-Frontal/metabolismo , Animais , Ansiedade/psicologia , Aprendizagem da Esquiva/fisiologia , Comportamento Exploratório/fisiologia , Sistema Límbico/metabolismo , Masculino , Ratos , Ratos Wistar , Fatores de TempoRESUMO
The hydroalcoholic extract of Equisetum arvense (HAE) tested at the doses of 200 and 400 mg/kg showed a significant activity on the open-field, enhanced the number of falls in the rota-rod reducing the time of permanence in the bar and increased the sleeping time (46% and 74%) in the barbiturate-induced sleeping time. In the pentylenetetrazole-seizure, it increased the first convulsion latency, diminished the severity of convulsions, reduced the percentage of animals which developed convulsion (50% and 25%) and protected animals from death. On the contrary, in the elevated plus maze, the doses 50, 100 and 150 mg/kg did not affect the evaluated parameters. Thus, HAE presented anticonvulsant and sedative effects. Phytochemical analysis detected the presence of tannins, saponins, sterols and flavonoids.
Assuntos
Anticonvulsivantes/farmacologia , Equisetum , Hipnóticos e Sedativos/farmacologia , Aprendizagem em Labirinto/efeitos dos fármacos , Fitoterapia , Extratos Vegetais/farmacologia , Convulsões/prevenção & controle , Sono/efeitos dos fármacos , Animais , Anticonvulsivantes/administração & dosagem , Anticonvulsivantes/uso terapêutico , Relação Dose-Resposta a Droga , Feminino , Hipnóticos e Sedativos/administração & dosagem , Hipnóticos e Sedativos/uso terapêutico , Masculino , Pentilenotetrazol , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêutico , Caules de Planta , Ratos , Ratos Wistar , Convulsões/induzido quimicamenteRESUMO
Venlafaxine, an atypical antidepressant drug, has been used to treat several neurological disorders, presenting excellent efficacy and tolerability. Clinical seizures after venlafaxine treatment have occasionally been reported when the drug was used at very high doses or in combination with other medications. The aim of the present study was to investigate the convulsant effects of venlafaxine in rats under controlled laboratory conditions. Adult male Wistar rats (8 per group) receiving venlafaxine or saline at the doses of 25-150 mg/kg were subjected 30 min later to injections of pentylenetetrazole at the dose of 60 mg/kg. The animals receiving 75, 100 and 150 mg/kg venlafaxine presented increased severity of convulsion when compared to controls (P = 0.02, P = 0.04, and P = 0.0004, respectively). Indeed, an increased percentage of death was observed in these groups (50, 38, and 88%, respectively) when compared to the percentage of death in the controls (0%). The group receiving 150 mg/kg showed an reduction in death latency (999 +/- 146 s) compared to controls (1800 +/- 0 s; cut-off time). Indeed, in this group, all animals developed seizures prior to pentylenetetrazole administration. Surprisingly, the groups receiving venlafaxine at the doses of 25 and 50 mg/kg showed a tendency towards an increase in the latency to the first convulsion. These findings suggest that venlafaxine at doses of 25 and 50 mg/kg has some tendency to an anticonvulsant effect in the rat, whereas doses of 75, 100 and 150 mg/kg presented clear proconvulsant effects in rats submitted to the pentylenetetrazole injection. These findings are the first report in the literature concerning the role of venlafaxine in seizure genesis in the rat under controlled conditions.
Assuntos
Antidepressivos de Segunda Geração/efeitos adversos , Cicloexanóis/efeitos adversos , Convulsões/induzido quimicamente , Animais , Antidepressivos de Segunda Geração/administração & dosagem , Convulsivantes , Cicloexanóis/administração & dosagem , Interações Medicamentosas , Masculino , Pentilenotetrazol , Ratos , Ratos Wistar , Cloridrato de VenlafaxinaRESUMO
Venlafaxine, an atypical antidepressant drug, has been used to treat several neurological disorders, presenting excellent efficacy and tolerability. Clinical seizures after venlafaxine treatment have occasionally been reported when the drug was used at very high doses or in combination with other medications. The aim of the present study was to investigate the convulsant effects of venlafaxine in rats under controlled laboratory conditions. Adult male Wistar rats (8 per group) receiving venlafaxine or saline at the doses of 25-150 mg/kg were subjected 30 min later to injections of pentylenetetrazole at the dose of 60 mg/kg. The animals receiving 75, 100 and 150 mg/kg venlafaxine presented increased severity of convulsion when compared to controls (P = 0.02, P = 0.04, and P = 0.0004, respectively). Indeed, an increased percentage of death was observed in these groups (50, 38, and 88 percent, respectively) when compared to the percentage of death in the controls (0 percent). The group receiving 150 mg/kg showed an reduction in death latency (999 + or - 146 s) compared to controls (1800 + or - 0 s; cut-off time). Indeed, in this group, all animals developed seizures prior to pentylenetetrazole administration. Surprisingly, the groups receiving venlafaxine at the doses of 25 and 50 mg/kg showed a tendency towards an increase in the latency to the first convulsion. These findings suggest that venlafaxine at doses of 25 and 50 mg/kg has some tendency to an anticonvulsant effect in the rat, whereas doses of 75, 100 and 150 mg/kg presented clear proconvulsant effects in rats submitted to the pentylenetetrazole injection. These findings are the first report in the literature concerning the role of venlafaxine in seizure genesis in the rat under controlled conditions
Assuntos
Animais , Masculino , Ratos , Antidepressivos de Segunda Geração , Convulsões , Antidepressivos de Segunda Geração , Interações Medicamentosas , Pentilenotetrazol , Ratos Wistar , Estatísticas não ParamétricasRESUMO
The isolation of 1-hydroxy-3,7-dimethoxyxanthone (1) from Shultesia guianensis is reported along with relevant NMR spectra, including new data by two-dimensional NMR experiments (HMQC and HMBC).
Assuntos
Gentianaceae , Extratos Vegetais/química , Xantenos/química , Xantonas , Humanos , Espectroscopia de Ressonância MagnéticaRESUMO
The effects of methyleugenol (ME) on guinea-pig isolated ileum were studied. ME reversibly relaxed basal tonus (EC50 of 52.2 +/- 18.3 microM), an action unaltered by 0.5 microM tetrodotoxin or 0.5 mM hexamethonium, and relaxed the ileum pre-contracted with 60 mM KCl. ME slightly hyperpolarized the ileum from -57.3 to -62.8 mV but had no effect in depolarised tissues. ME inhibited contractions induced by ACh, histamine and KCl with IC50 values of approximately 82, 124, and 65 microM, respectively. Our results suggest that ME induces relaxation of guinea-pig ileum by a direct action on smooth muscle via a mechanism largely independent of alterations of membrane potential (Em).
Assuntos
Eugenol/análogos & derivados , Músculo Liso/efeitos dos fármacos , Parassimpatolíticos/farmacologia , Acetilcolina/farmacologia , Animais , Epinefrina/farmacologia , Eugenol/farmacologia , Cobaias , Histamina/farmacologia , Íleo/efeitos dos fármacos , Íleo/fisiologia , Técnicas In Vitro , Masculino , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Relaxamento Muscular/efeitos dos fármacos , Relaxamento Muscular/fisiologia , Músculo Liso/fisiologia , Cloreto de Potássio/farmacologiaRESUMO
Recent trends in migration affecting the Brazilian state of Paraiba are analyzed. "Three dimensions of the state's migrations are analysed here: inter-state mobility, the growth of urban population, and the rural exodus. The central thesis of this study is that the migration of Paraiba's population is an element which is determined by and at the same time determines the process of production and the conformity of space to the logic of profit at the present stage of Brazilian capitalist development. The intensity of emigration from Paraiba cannot be understood when it is divorced from the process of the organization of the socio-economic space of the nation. The greater the imbalance between the economy of the state and that of Brazil's metropolises, the more frequent are the fluxes of migrants. On the [other] hand conservative modernization of agriculture has largely contributed to strengthen the causes of the ousting of peasants inherent to the state's economic framework." (SUMMARY IN ENG)
Assuntos
Agricultura , Demografia , Economia , Emigração e Imigração , Dinâmica Populacional , Crescimento Demográfico , Mudança Social , Fatores Socioeconômicos , População Urbana , América , Brasil , Países em Desenvolvimento , América Latina , População , Características da População , Pesquisa , América do SulRESUMO
Estudando uma amostra de 176 casos de portadores de lentes progressivas, o autor, mostrando a eficacia do seu metodo de exames destas lentes, correlaciona os defeitos encontrados as queixas dos seus portadores
Assuntos
Oftalmopatias , Lentes IntraocularesRESUMO
O autor estabelece conceitos sobre a variabilidade da refratometria ocular utilizando metodos da logica formal
Assuntos
RefratometriaAssuntos
Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Humanos , Masculino , Feminino , Tireoidectomia , Neoplasias da Glândula Tireoide , Bócio , Doenças da Glândula TireoideRESUMO
O epitelio do pterigio apresenta, como principal alteracao, a metaplasia escamosa. Ela e tambem predominante e parece uma sua caracteristica. Ha comumente pigmentacao melanica assim como pseudo-glandula. A presenca de glandulas, mesmo nao sendo muito frequente, nao pode ser considerada como anomalia. A presenca de displasia, relativamente alta, sugere a observacao do pterigio como campo potencial de neoplasias
Assuntos
Humanos , Epitélio , Pterígio , MetaplasiaRESUMO
O modelo apresentado pelo autor, permite conhecer certas especificidades das lentes progressivas como centros opticos prismados, diferenca entre as lentes progressivas concavas e convexas, variabilidade das zonas de progressao e os efeitos das descentracoes
Assuntos
Óculos , Óptica e FotônicaRESUMO
O Autor estudou os componentes da acomodacao sob os aspectos embriologicos, anatomicos e fisiologicos. Atualizou o conceito de Weale sobre o carater multifatorial da acomodacao e acrescentou o papel do vitreo baseado nos achados de Coleman. Foram assinalados dados sobre a manifestacao e a evolucao da presbiopia na nossa regiao. Dados clinicos levaram o autor a sustentar o carater limitado da atuacao do corpo ciliar atribuindo ao cristalino papel preponderante na acomodacao