48 resultados para FUNCTIONAL-ASPECTS

em Reposit


Relevância:

100.00% 100.00%

Publicador:

Resumo:

A study of the anatomy and ultrastructural aspects of leaf mesophyll and floral nectaries of Hymenaea stigonocarpa Mart. ex Hayne revealed the presence of intercellular pectic protuberances (IPPs) linking adjacent cells in both the leaf palisade cells and the secretory parenchyma of the floral nectary. Samples of the middle third of the leaf blade and of floral nectaries in anthesis were collected, fixed, and processed using standard procedures for light, transmission, and scanning electron microscopies. The IPPs of palisade cells of the mesophyll and the secretory parenchyma cells of the floral nectary take the form of scalae or strands, respectively. No evidence of the specific synthesis of these structures was observed, and they are apparently formed by the separation of adjacent cells due to cell expansion, when intercellular spaces develop. The IPPs observed in H. stigonocarpa increase cellular contact and probably act in apoplastic transport.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Snake venom glands are a rich source of bioactive molecules such as peptides, proteins and enzymes that show important pharmacological activity leading to in local and systemic effects as pain, edema, bleeding and muscle necrosis. Most studies on pharmacologically active peptides and proteins from snake venoms have been concerned with isolation and structure elucidation through methods of classical biochemistry. As an attempt to examine the transcripts expressed in the venom gland of Bothrops jararacussu and to unveil the toxicological and pharmacological potential of its products at the molecular level, we generated 549 expressed sequence tags (ESTs) from a directional cDNA library. Sequences obtained from single-pass sequencing of randomly selected cDNA clones could be identified by similarities searches on existing databases, resulting in 197 sequences with significant similarity to phospholipase A(2) (PLA(2)), of which 83.2% were Lys49-PLA(2) homologs (BOJU-1), 0.1% were basic Asp49-PLA(2)s (BOJU-II) and 0.6% were acidic Asp49-PLA(2)s (BOJU-III). Adjoining this very abundant class of proteins we found 88 transcripts codifying for putative sequences of metalloproteases, which after clustering and assembling resulted in three full-length sequences: BOJUMET-I, BOJUMET-II and BOJUMET-III; as well as 25 transcripts related to C-type lectin like protein including a full-length cDNA of a putative galactose binding C-type lectin and a cluster of eight serine-proteases transcripts including a full-length cDNA of a putative serine protease. Among the full-length sequenced clones we identified a nerve growth factor (Bj-NGF) with 92% identity with a human NGF (NGHUBM) and an acidic phospholipase A2 (BthA-I-PLA(2)) displaying 85-93% identity with other snake venom toxins. Genetic distance among PLA(2)s from Bothrops species were evaluated by phylogenetic analysis. Furthermore, analysis of full-length putative Lys49-PLA(2) through molecular modeling showed conserved structural domains, allowing the characterization of those proteins as group II PLA(2)s. The constructed cDNA library provides molecular clones harboring sequences that can be used to probe directly the genetic material from gland venom of other snake species. Expression of complete cDNAs or their modified derivatives will be useful for elucidation of the structure-function relationships of these toxins and peptides of biotechnological interest. (C) 2004 Elsevier SAS. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

70.00% 70.00%

Publicador:

Resumo:

Crotoxin is a neurotoxin from Crotalus durissus terrificus venom that shows immunomodulatory, anti-inflammatory, antimicrobial, antitumor and analgesic activities. Structurally, this toxin is a heterodimeric complex composed by a toxic basic PLA2 (Crotoxin B or CB) non-covalently linked to an atoxic non-enzymatic and acidic component (Crotapotin, Crotoxin A or CA). Several CA and CB isoforms have been isolated and characterized, showing that the crotoxin venom fraction is, in fact, a mixture of different molecules derived from the combination of distinct subunit isoforms. Intercro (IC) is a protein from the same snake venom which presents high similarity in primary structure to CB, indicating that it could be an another isoform of this toxin. In this work, we compare IC to the crotoxin complex (CA/CB) and/or CB in order to understand its functional aspects. The experiments with IC revealed that it is a new toxin with different biological activities from CB, keeping its catalytic activity but presenting low myotoxicity and absence of neurotoxic activity. The results also indicated that IC is structurally similar to CB isoforms, but probably it is not able to form a neurotoxic active complex with crotoxin A as observed for CB. Moreover, structural and phylogenetic data suggest that IC is a new toxin with possible toxic effects not related to the typical CB neurotoxin. © 2013.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

Case Report. An 8-year-old girl with amelogenesis imperfecta (AI) reported unsatisfactory aesthetics, difficulty in mastication, and dental hypersensitivity. The intraoral examination observed mixed dentition, malocclusion in anteroposterior relationships, anterior open bite, and dental asymmetry. A hypoplastic form of AI was diagnosed in the permanent dentition. A multidisciplinary planning was performed and divided into preventive, orthopedic, and rehabilitation stages. Initially, preventive treatment was implemented, with fluoride varnish applications, in order to protect the fragile enamel and reduce the dental sensitivity. In the second stage, the patient received an interceptive orthopedic treatment to improve cross-relationship of the arches during six months. Finally, the rehabilitation treatment was executed to establish the vertical dimension. In the posterior teeth, indirect composite resin crowns were performed with minimally invasive dental preparation. Direct composite resin restorations were used to improve the appearance of anterior teeth. Follow-Up. The follow-up was carried out after 3, 6, 12, and 18 months. After 18 months of follow-up, The restoration of integrity, oral hygiene, and patient satisfaction were observed . Conclusion. Successful reduction of the dental hypersensitivity and improvement of the aesthetic and functional aspects as well as quality of life were observed.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Para avaliar o uso da eletroacupuntura (EA) sobre os aspectos clínicos e deambulatórios, 36 coelhos tiveram o tendão calcanear comum seccionado e, após 30 dias, receberam enxerto de peritônio bovino conservado em solução supersaturada de sal. em seguida, os animais foram distribuídos aleatoriamente em três grupos de igual número: no primeiro grupo, os coelhos foram estimulados pela EA do segundo ao 11° dia de pós-operatório (PO) (E10); no segundo grupo do 11o ao 31o dia de PO (E20) e, no terceiro grupo, os animais não foram estimulados (C). Verificou-se, nos animais do E10, durante o PO, ausência de edema e hiperemia no membro tratado pela EA. Não se observou diferença significativa (P>0,05) entre os grupos quanto ao grau de deambulação dos animais. Todos os coelhos tiveram completa recuperação da deambulação até os 51 dias de PO. A utilização da eletroacupuntura na fase precoce da cicatrização do tendão calcanear comum de coelhos impediu a formação de edema e hiperemia. O tratamento com eletroacupuntura no PO não melhorou o desempenho da deambulação.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Comunidades de Ephemeroptera, Plecoptera e Trichoptera (EPT) em substrato rochoso foram estudadas em dois riachos do Parque Estadual Intervales. Coletas com um amostrador de Surber (10 subamostras aleatórias, 1 m²) foram feitas mensalmente de setembro de 1999 a setembro de 2000 e trimestralmente de dezembro de 2000 a setembro de 2001 nos Ribeirões Bocaina e Água Comprida. A fauna de EPT do Ribeirão Bocaina foi mais diversificada e mais abundante do que a do Ribeirão Água Comprida. A fauna de EPT foi bastante diferente entre os dois riachos, tanto do ponto de vista da composição faunística quanto do ponto de vista funcional. Os resultados indicaram que não houve um padrão sazonal claro da variação temporal da densidade.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

60.00% 60.00%

Publicador:

Resumo:

É apresentada uma análise dos possíveis impactos que a diminuição da vegetação nativa, notadamente das florestas ripárias, pode causar sobre a ictiofauna. Três conjuntos de aspectos funcionais primordiais desempenhados pelas florestas ripárias são discutidos: transferência de energia solar ao ambiente aquático, interceptação de nutrientes e sedimentos que adentram nos rios e trocas de material orgânico entre o sistema terrestre e aquático. Conclui-se que qualquer alteração que se traduza em mais perdas de vegetação nativa, seja em áreas de preservação permanente ou em reservas legais, pode gerar perdas de espécies, homogeneização faunística e diminuição de biomassa íctica.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

60.00% 60.00%

Publicador:

Resumo:

INTRODUÇÃO: O movimento de alcance é muito estudado na literatura, no entanto, poucos estudos realizam análise cinemática e eletromiográfica desse movimento em sujeitos hemiparéticos. OBJETIVO: Avaliar o alcance de indivíduos hemiparéticos pós-acidente vascular encefálico (AVE) em seus aspectos cinemáticos e eletromiográficos. MATERIAIS E MÉTODOS: Foram selecionados quatro indivíduos, idade média de 54,5 ± 10,7 anos, com diagnóstico de AVE associado à hemiparesia. Realizou-se a avaliação cinemática e eletromiográfica concomitantemente do movimento de alcance na postura sentada, tanto do lado parético quanto do não parético. RESULTADOS: Houve diferença significativa entre os sujeitos com relação ao deslocamento (F(3,63) = 3.081, p = 0.03), porém, não ocorreu diferença significativa entre os lados (F(1,63) = 1.441, p = 0.23). Com relação às articulações (ombro, cotovelo e punho), houve diferença significativa entre os deslocamentos de cada uma (F(2,63) = 27.496, p = 0.00), assim como entre as coordenadas x, y e z (F(2,63) = 36.702, p = 0.00). Na análise dos dados eletromiográficos, não houve diferença significativa entre os sujeitos (F(3,31) = 2.437, p = 0.08), entre os lados (F(1,31) = 3.384, p = 0.07) e entre os músculos (F(4,31) = 0.942, p = 0.45). Existiu diferença no tempo de execução dos movimentos quando comparado o lado não acometido com o acometido. CONCLUSÃO: As análises cinemática e eletromiográfica, de um modo geral, mostraram resultados semelhantes aos encontrados na literatura. No entanto, este estudo acrescenta uma visão mais sistematizada do movimento de alcance, considerando seus aspectos funcionais, diferindo de outros estudos por apresentar, concomitantemente, análises cinemática e eletromiográfica e por investigar ambos os membros superiores.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The oxygenation of human Hb (HbA) demands a three state model: two deoxy states To and Tx, free and complexed with anions respectively, and an oxy R state. The regulation between these states is modulated by the presence of anions, such as chloride, that binds to T state. The b inding if chloride, however, remains controversial. The aim of this work is the study of arginines 92a (a1ß2 interface) and 141a (C-terminal) as chloride binding sites. To investigate that, we have studied 92 and 141 site directed mutant species: natural mutants Hb J-Cape-Town (R92Q), desArg (R141Δ), Chesapeake (R92L), and the constructed Chesapeake desArg (R92L,141Δ). We expressed Hbs in Escherichia coli and purified. Through oxygen binding curves we measured affinity and cooperativity, in function of water effect and Bohr effect in presence and absence of chloride. Structural features were obtained through 1H NMR spectroscopy Oxygen binding properties and Bohr effect measured indicated a higher affinity and lower cooperativity in absence and presence of chloride for all mutants. Structural changes represent functional aspects of mutant Hbs, such as a significant rise in affinity or a change in cooperativity. Water activity studies conducted as a function of chloride concentration showed that the only Hb desArg follows the thre state model. The other mutant Hbs do not exhibit the Tx state, a fact confirmed by the number of water molecules bound to each Hb during the deoxy-oxy transition. This behavior suggests that the Arginine 92 site could be responsible for chloride binding to Hb, since oxygenation of 92 mutant Hbs cannot be adjusted by the three state model. However, Bohr effect showed that all mutant Hbs released~1 proton in chloride presence, different from HbA that releases ~2, suggesting a role for 141 arginine in the tertiary and quaternary Bohr effect.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

PURPOSE: To present fundamental anatomical aspects and technical skills necessary to urethra and urinary bladder catheterization in female mice and rats. METHODS: Urethral and bladder catheterization has been widely utilized for carcinogenesis and cancer research and still remains very useful in several applications: from toxicological purposes as well as inflammatory and infectious conditions to functional aspects as bladder dynamics and vesicoureteral reflux, among many others. RESULTS: Animal models are in the center of translational research and those involving rodents are the most important nowadays due to several advantages including human reproducibility, easy handling and low cost. CONCLUSIONS: Although technical and anatomical pearls for rodent urethral and bladder access are presented as tackles to the advancement of lower urinary tract preclinical investigation in a broaden sight, restriction to female animals hampers the male microenvironment, demanding future advances.