alpha-Conotoxin ImI inhibits the alpha-bungarotoxin-resistant nicotinic response in bovine adrenal chromaffin cells

The activity of alpha-conotoxin (alpha-CTX) lml, from the vermivorous marine snail Conus imperialis, has been studied on mammalian nicotinic receptors on bovine chromaffin cells and at the rat neuromuscular junction. Synthetic alpha-CTX lml was a potent inhibitor of the neuronal[ nicotinic response in bovine adrenal chromaffin cells (IC50 = 2.5 mu M, log IC50 = 0.4 +/- 0.07), showing competitive inhibition of nicotine-evoked catecholamine secretion. (alpha-CTX lml also inhibited nicotine-evoked Ca-45(2+) uptake but not Ca-45(2+) uptake stimulated by 56 mM Kr. In contrast, alpha-CTX lml had no effect at the neuromuscular junction over the concentration range 1-20 mu M. Bovine chromaffin cells are known to contain the alpha 3 beta 4, alpha 7, and (possibly) alpha 3 beta 4 alpha 5 subtypes. However, the secretory response of bovine chromaffin cells is not inhibited by alpha-bungarotoxin, indicating that alpha 7 nicotinic receptors are not involved. We propose that alpha-CTX lml interacts selectively with the functional (alpha 3 beta 4 or alpha 3 beta 4 alpha 5) nicotinic acetylcholine receptor to inhibit the neuronal-type nicotinic response in bovine chromaffin cells.

Solution structure of alpha-conotoxin ImI by H-1 nuclear magnetic resonance

alpha-Conotoxin ImI derives from the venom of Conus imperialis and is the first and only small-peptide ligand that selectively binds to the neuronal alpha(7) homopentameric subtype of the nicotinic acetylcholine receptor (nAChR). This receptor subtype is a possible drug target for several neurological disorders. The cysteines are connected in the pairs Cys2-Cys8 and Cys3-Cys12, To date it is the only alpha-conotoxin with a 4/3 residue spacing between the cysteines, The structure of ImI has been determined by H-1 NMR spectroscopy in aqueous solution, The NMR structure is of high quality, with a backbone pairwise rmsd of 0.34 Angstrom for a family of 19 structures, and comprises primarily a series of nested beta turns. Addition of organic solvent does not perturb the solution structure. The first eight residues of ImI are identical to the larger, but related, conotoxin EpI and adopt a similar structure, despite a truncated second loop. Residues important for binding of ImI to the alpha 7 nAChR are all clustered on one face of the molecule. Once further binding data for EPI and ImI are available, the ImI structure will allow for design of novel alpha(7) nAChR-specific agonists and antagonists with a wide range of potential pharmaceutical applications.

IMI: ELES COMEM TUDO E NÃO DEIXAM NADA

O IMI é aliás, em si mesmo, um imposto profundamente injusto. A sua aplicação constitui, em muitos casos, uma situação de Abuso do Direito, art. 334º do Código Civil. A sua concretização implica uma violação do fim económico e social da própria Justiça no Direito. O sistema fiscal não objectiva apenas as necessidades financeiras do Estado e doutras entidades públicas, mas também, e sobretudo uma repartição justa dos rendimentos e da riqueza: art. 103º da Constituição. É claro que, para isso, tem que existir também um controlo rigoroso e honesto da gestão e da distribuição constitucional dos dinheiros públicos. § IMI is indeed in itself a profoundly unfair tax. Its use is in many cases a right Abuse situation art. 334 of the Civil Code. Its implementation involves a violation of economic and social justice at the end of its law. The tax system does not seek only the financial needs of the state and of other public authorities, but also and especially a fair distribution of income and wealth: art. 103 of the Constitution. Of course, for this, it must also be a rigorous and honest control of the constitutional management and distribution of public funds.

Práticas sobre o ordenamento e fiscalidade do território : caso de estudo IMI

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia do Ambiente, perfil de Gestão e Sistemas Ambientais

Joan Eckii ... De materia iuramenti accutiss[imi] decisio ad Georgium Kungspergium augustanum.

Mode of access: Internet.

Doklad ob otvi︠e︡tstvennosti obshchestv zheli︠e︡znykh dorog za srochnui︠u︡ dostavku i t︠s︡i︠e︡lostʹ pervozimykh imi gruzov /

Mode of access: Internet.

Opisanīe kubanskago imi͡enīi͡a "Khutorok" barona V.R. Shteĭngelʹ : 1900 g. /

Mode of access: Internet.

Khozi︠a︡ĭstvennye opyty : tridt︠s︡atili︠e︡tneĭ praktiki ili nastavlenīe dli︠a︡ upravlenīi︠a︡ imi︠enīi︠a︡mi /

Mode of access: Internet.

E-Perakendecilik ve Gelişimi Engelleyen Dirençler

Günümüzde e-perakendeciler tüketicilerin isteklerine cevap verdiklerini iddia ederken, acaba tüketicilere yegane seçenekleri sunmakta olduklarini göz ardi mi ediyorlar? Özellikle gelisen pazar sartlarinda, kamusal alanlarin özellestirilmesi ve güvenlikli sitelerin insasi ile tüketicilerin geo-demografik özellikleri degisirken vakti kisitli ama alim gücü yüksek bireylerin katma degerli farkli hizmet seçenekleri beklentisi içerisine girmelerine yol açiyor. Ancak, günümüzde perakendecilerin yeni e-market uygulamalarina gösterdikleri direnç, modern e-tüketicilerin nitelikli ürün ve servis firsatlarindan faydalanmasini engelliyor. Bilgi ve iletisim teknolojilerindeki son gelismeler, e-kanallar söz konusu oldugunda lojistik aginin küçük ölçekli nitelikli ürünlere yönelik mikro düzeyde degerlendirilmesi gerekmekte ve kentsel yenilenme, e-perakende firmalari, lojistik saglayicilar ve kentsel planlamacilar arasinda bir isbirligi ihtiyaci dogurmaktadir. Ancak öte yandan hizla degisen perakende yapisi içerisinde, yerel cografyanin etkisini ve çoklu iliskileri anlama konusunda e-kanallarda varlik gösteren bu üç oyuncunun gösterdigi karsilikli direnç de önemli bir role sahip olarak ortaya çikmakta. Süreci yöneten üç aktörün dinamik bir pazar yapisi içerisinde e-market dagitim planlama ve uygulama süreçlerine gösterdikleri direnç detayli olarak incelenmelidir. Peki, ucunda daha iyi hizmet verebilmek, daha çok kazanç elde etmek de olsa çoklu entegrasyona ve isbirliksel ortakliga gösterilen bu çift tarafli direncin sebepleri acaba nedir?

VEGF Promotes Malaria-Associated Acute Lung Injury in Mice

The spectrum of the clinical presentation and severity of malaria infections is broad, ranging from uncomplicated febrile illness to severe forms of disease such as cerebral malaria (CM), acute lung injury (ALI), acute respiratory distress syndrome (ARDS), pregnancy-associated malaria (PAM) or severe anemia (SA). Rodent models that mimic human CM, PAM and SA syndromes have been established. Here, we show that DBA/2 mice infected with P. berghei ANKA constitute a new model for malaria-associated ALI. Up to 60% of the mice showed dyspnea, airway obstruction and hypoxemia and died between days 7 and 12 post-infection. The most common pathological findings were pleural effusion, pulmonary hemorrhage and edema, consistent with increased lung vessel permeability, while the blood-brain barrier was intact. Malaria-associated ALI correlated with high levels of circulating VEGF, produced de novo in the spleen, and its blockage led to protection of mice from this syndrome. In addition, either splenectomization or administration of the anti-inflammatory molecule carbon monoxide led to a significant reduction in the levels of sera VEGF and to protection from ALI. The similarities between the physiopathological lesions described here and the ones occurring in humans, as well as the demonstration that VEGF is a critical host factor in the onset of malaria-associated ALI in mice, not only offers important mechanistic insights into the processes underlying the pathology related with malaria but may also pave the way for interventional studies.

Bacterial soil community in a Brazilian sugarcane field

The assessment of bacterial communities in soil gives insight into microbial behavior under prevailing environmental conditions. In this context, we assessed the composition of soil bacterial communities in a Brazilian sugarcane experimental field. The experimental design encompassed plots containing common sugarcane (variety SP80-1842) and its transgenic form (IMI-1 - imazapyr herbicide resistant). Plants were grown in such field plots in a completely randomized design with three treatments, which addressed the factors transgene and imazapyr herbicide application. Soil samples were taken at three developmental stages during plant growth and analyzed using 16S ribosomal RNA (rRNA)-based PCR-denaturing gradient gel electrophoresis (PCR-DGGE) and clone libraries. PCR-DGGE fingerprints obtained for the total bacterial community and specific bacterial groups - Actinobacteria, Alphaproteobacteria and Betaproteobacteria - revealed that the structure of these assemblages did not differ over time and among treatments. Nevertheless, slight differences among 16S rRNA gene clone libraries constructed from each treatment could be observed at particular cut-off levels. Altogether, the libraries encompassed a total of eleven bacterial phyla and the candidate divisions TM7 and OP10. Clone sequences affiliated with the Proteobacteria, Actinobacteria, Firmicutes and Acidobacteria were, in this order, most abundant. Accurate phylogenetic analyses were performed for the phyla Acidobacteria and Verrucomicrobia, revealing the structures of these groups, which are still poorly understood as to their importance for soil functioning and sustainability under agricultural practices.

alpha-conotoxin EpI, a novel sulfated peptide from Conus episcopatus that selectively targets neuronal nicotinic acetylcholine receptors

We have isolated and characterized ol-conotoxin EpI, a novel sulfated peptide from the venom of the molluscivorous snail, Conus episcopatus, The peptide was classified as an cy-conotoxin based on sequence, disulfide connectivity, and pharmacological target. EpI has ho mology to sequences of previously described cu-conotoxins, particularly PnIA, PnIB, and ImI, However, EpI differs from previously reported conotoxins in that it has a sulfotyrosine residue, identified by amino acid analysis and mass spectrometry, Native EpI was shown to coelute with synthetic EpI, The peptide sequence is consistent with most, but not all, recognized criteria for predicting tyrosine sulfation sites in proteins and peptides, The activities of synthetic EpI and its unsulfated analogue [Tyr(15)]EpI were similar. Both peptides caused competitive inhibition of nicotine action on bovine adrenal chromaffin cells (neuronal nicotinic ACh receptors) but had no effect on the rat phrenic nerve-diaphragm (muscle nicotinic ACh receptors), Both EpI and [Tyr(15)]EpI partly inhibited acetylcholine-evoked currents in isolated parasympathetic neurons of rat intracardiac ganglia, These results indicate that EPI and [Tyr(15)]EpI selectively inhibit alpha 3 beta 2 and alpha 3 beta 4 nicotinic acetylcholine receptors.

Applications of NMR in drug design: Sructure-activity relationships in disulfide-rich peptides

NMR is a powerful technique for determining structures of biologically active molecules in solution. In recent years. our laboratory has focussed on the structure determination of small disulfide-rich proteins from both plants and animals which are valuable targets in drug design applications. This article will review these structural studies and their implications in drug design.

Leu(10) of alpha-conotoxin PnIB confers potency for neuronal nicotinic responses in bovine chromaffin cells

Two alpha-conotoxins PnIA and PnIB (previously reported as being mollusc specific) which differ in only two amino acid residues (AN versus LS at residues 10 and 11, respectively), show markedly different inhibition of the neuronal nicotinic acetylcholine receptor response in bovine chromaffin cells, a mammalian preparation. Whereas alpha-conotoxin PnIB completely inhibits the nicotine-evoked catecholamine release at 10 mu M, with IC50 = 0.7 mu M, alpha-conotoxin PnIA is some 30-40 times less potent. Two peptide analogues, [A10L]PnIA and [N11S]PnIA were synthesized to investigate the extent to which each residue contributes to activity. [A10L]PnIA (IC50 = 2.0 mu M) completely inhibits catecholamine release at 10 mu M whereas [N11S]PnIA shows Little inhibition. In contrast, none of the peptides inhibit muscle-type nicotinic responses in the rat hemi-diaphragm preparation. We conclude that the enhanced potency of alpha-conotoxin PnIB over alpha-conotoxin PnIA in the neuronal-type nicotinic response is principally determined by the larger, more hydrophobic leucine residue at position 10 in alpha-conotoxin PnIB. (C) 2000 Elsevier Science B.V. All rights reserved.

alpha-conotoxins EpI and AuIB switch subtype selectivity and activity in native versus recombinant nicotinic acetylcholine receptors

The Xenopus laevis oocyte expression system was used to determine the activities of alpha-conotoxins EpI and the ribbon isomer of AuIB, on defined nicotinic acetylcholine receptors (nAChRs). In contrast to previous findings on intracardiac ganglion neurones, alpha-EpI showed no significant activity on oocyte-expressed alpha3beta4 and alpha3beta2 nAChRs but blocked the alpha7 nAChR with an IC50 value of 30 nM. A similar IC50 value (103 nM) was obtained on the alpha7/5HT(3) chimeric receptor stably expressed in mammalian cells. Ribbon AuIB maintained its selectivity on oocyte-expressed alpha3beta4 receptors but unlike in native cells, where it was 10-fold more potent than native alpha-AuIB, had 25-fold lower activity. These results indicate that as yet unidentified factors influence alpha-conotoxin pharmacology at native versus oocyte-expressed nAChRs. (C) 2003 Published by Elsevier B.V. on behalf of the Federation of European Biochemical Societies.