965 resultados para 11260658 M1
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The present work is to understand the alterations of total Muscarinic and Muscarinic MI receptors in brain and pancreatic islets of Streptozotocin induced diabetic rats. The work focuses on the evaluation of the antihyperglycemic activity of aqueous extracts of Aegle marmelose and Costus pictus leaves in vivo and the changes in the total Muscarinic and Muscarinic MI receptors during diabetes and after the treatment with insulin. The insulin secretory activity of Aegle marmelose and Costus pictus leaf extracts and the effect of cholinergic receptor agonist were investigated in vitro using rat primary pancreatic islet culture. Muscarinic MI receptor kinetics and gene expression during diabetes and regulation of insulin secretion by Aegle marmelose and Costus pie/us leaf extracts will help us to elucidate the role of Muscarinic and Muscarinic MI receptors in hyperglycemia and the regulatory activity of these plant extracts on insulin secretion through Muscarinic receptors.
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The present study describes that acetylcholine through muscarinic Ml and M3 receptors play an important role in the brain function during diabetes as a function of age. Cholinergic activity as indicated by acetylcholine esterase, a marker for cholinergic function, decreased in the brain regions - the cerebral cortex, brainstem and corpus striatum of old rats compared to young rats. in diabetic condition, it was increased in both young and old rats in cerebral cortex, and corpus striatum while in brainstem it was decreased. The functional changes in the muscarinic receptors were studied in the brain regions and it showed that muscarinic M I receptors of old rats were down regulated in cerebral cortex while in corpus striatum and brainstem it was up regulated. Muscarinic M3 receptors of old rats showed no significant change in cerebral cortex while in corpus striatum and brainstem muscarinic receptors were down regulated. During diabetes, muscarinic M I receptors were down regulated in cerebral cortex and brainstem of young rats while in corpus striatum they were up regulated. In old rats, M I receptors were up regulated in cerebral cortex, corpus striatum and in brainstem they were down regulated. Muscarinic M3 receptors were up regulated in cerebral cortex and brainstem of young rats while in corpus striatum they were down regulated. In old rats, muscarinic M l receptors were up regulated in cerebral cortex, corpus striatum and brainstem. In insulin treated diabetic rats the activity of the receptors were reversed to near control. Pancreatic muscarinic M3 receptor activity increased in the pancreas of both young and old rats during diabetes. In vitro studies using carbachol and antagonists for muscarinic Ml and M3 receptor subtypes confirmed the specific receptor mediated neurotransmitter changes during diabetes. Calcium imaging studies revealed muscarinic M I mediated Ca2 + release from the pancreatic islet cells of young and old rats. Electrophysiological studies using EEG recording in young and old rats showed a brain activity difference during diabetes. Long term low dose STH and INS treated rat brain tissues were used for gene expression of muscarinic Ml, M3, glutamate NMDARl, mGlu-5,alpha2A, beta2, GABAAa1 and GABAB, DAD2 and 5-HT 2C receptors to observe the neurotransmitter receptor functional interrelationship for integrating memory, cognition and rejuvenating brain functions in young and old. Studies on neurotransmitter receptor interaction pathways and gene expression regulation by second messengers like IP3 and cGMP in turn will lead to the development of therapeutic agents to manage diabetes and brain activity.From this study it is suggested that functional improvement of muscarinic Ml, M3, glutamate NMDAR1, mGlu-5, alpha2A, beta2, GABAAa1 and GABAB, DAD2 and 5-HT 2C receptors mediated through IP3 and cGMP will lead to therapeutic applications in the management of diabetes. Also, our results from long term low dose STH and INS treatment showed rejuvenation of the brain function which has clinical significance in maintaining healthy period of life as a function of age.
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In this article I provide a critical account of the 'placing' of England's M1 motor-way. I start by critiquing Marc Auge's anthropological writings on 'non-places' which have provided a common point of reference for academics discussing spaces of travel, consumption and exchange in the contemporary world. I argue that Auge's ethnology of supermodernity results in a rather partial account of these sites, that he overstates the novelty of contemporary experiences of these spaces, and that he fails to acknowledge the heterogeneity and materiality of the social networks bound up with the production of non-places/places. I suggest that, rather than focusing on the presences and absences associated with the polarities of place and non-place, academics should examine the multiple, partial, dynamic and relational 'placings' which arise through the diverse performances and movements associated with travel, consumption and exchange. I then trace the topologies of England's M1 motorway, examining some of the different ways in which the motorway has been assembled, performed and placed over the past 45 years.
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Recent years have seen an increasing number of academics attempt to write more process-oriented and 'nonrepresentational' accounts of landscape. Drawing upon this literature, I discuss a number of the movements, materialities, and practices entailed in constructing England's M1 motorway in the late 1950s. The performances, movements and durability of a diverse range of things-including earth-moving machines, public relations brochures, maps, helicopters, senior engineers, aggregate and labourers-are shown to be important to the construction and ordering of the motorway and spaces of the construction company in different times and spaces, with people's experiences or understandings of construction, both now and in the past, emerging through memories, talk and embodied encounters with architectures, texts and artefacts which are assembled, circulated and/or archived. Aerial perspectives assumed a prominent role in depictions of construction, while journalists and engineers frequently drew upon a military vocabulary and alluded to the military nature of the project when discussing the motorway. (c) 2005 Elsevier Ltd. All rights reserved.
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We show that most isolates of influenza A induce filamentous changes in infected cells in contrast to A/WSN/33 and A/PR8/34 strains which have undergone extensive laboratory passage and are mouse-adapted. Using reverse genetics, we created recombinant viruses in the naturally filamentous genetic background of A/Victoria/3/75 and established that this property is regulated by the M1 protein sequence, but that the phenotype is complex and several residues are involved. The filamentous phenotype was lost when the amino acid at position 41 was switched from A to V, at the same time, this recombinant virus also became insensitive to the antibody 14C2. On the other hand, the filamentous phenotype could be fully transferred to a virus containing RNA segment 7 of the A/WSN/33 virus by a combination of three mutations in both the amino and carboxy regions of the M1 protein. This observation suggests that an interaction among these regions of M1 may occur during assembly. (C) 2004 Elsevier Inc. All rights reserved.
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In the present study, 24 samples of Minas Frescal cheese and 24 samples of Minas Padrao cheese produced in the North-east region of the state of Sao Paulo, Brazil, were analysed for aflatoxin M1 (AFM1) by high-performance liquid chromatography (HPLC) between March and August 2008. AFM1 was detected in 13 (27.1%) samples at concentrations ranging from 0.037 to 0.313 ng g-1. The mean concentrations of AFM1 in positive samples of Minas Frescal and Minas Padrao cheese were 0.142 +/- 0.118 and 0.118 +/- 0.054 ng g-1, respectively. It is concluded that the incidence of AFM1 in Minas cheese may contribute to an increase in the overall ingestion of aflatoxins in the diet, hence indicating the need for the adoption of a tolerance limit for AFM1 in cheese in Brazil.
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Bradykinin-potentiating peptides (BPPs) or proline-rich oligopeptides (PROs) isolated from the venom glands of Bothrops jararaca (Bj) were the first natural inhibitors of the angiotensin-converting enzyme (ACE) described. Bj-PRO-5a (< EKWAP), a member of this structurally related peptide family, was essential for the development of captopril, the first site-directed ACE inhibitor used for the treatment of human hypertension. Nowadays, more Bj-PROs have been identified with higher ACE inhibition potency compared to Bj-PRO-5a. However, despite its modest inhibitory effect of ACE inhibition, Bj-PRO-5a reveals strong bradykinin-potentiating activity, suggesting the participation of other mechanisms for this peptide. In the present study, we have shown that Bj-PRO-5a induced nitric oxide (NO) production depended on muscarinic acetylcholine receptor M1 subtype (mAchR-M1) and bradykinin B(2) receptor activation, as measured by a chemiluminescence assay using a NO analyzer. Intravital microscopy based on transillumination of mice cremaster muscle also showed that both bradykinin B(2) receptor and mAchR-M1 contributed to the vasodilatation induced by Bj-PRO-5a. Moreover, Bj-PRO-5a-mediated vasodilatation was completely blocked in the presence of a NO synthase inhibitor. The importance of this work lies in the definition of novel targets for Bj-PRO-5a in addition to ACE, the structural model for captopril development. (C) 2011 Elsevier Inc. All rights reserved.
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Proline-rich peptides from Bothrops jararaca venom (Bj-PRO) were characterized based on the capability to inhibit the somatic angiotensin-converting enzyme. The pharmacological action of these peptides resulted in the development of Captopril, one of the best examples of a target-driven drug discovery for treatment of hypertension. However, biochemical and biological properties of Bj-PROs were not completely elucidated yet, and many recent studies have suggested that their activity relies on angiotensin-converting enzyme-independent mechanisms. Here, we show that Bj-PRO-7a (
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Medicina Veterinária - FCAV
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)