963 resultados para alpha 1 adrenergic receptor stimulating agent


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Background: To validate STOPPFrail, a list of explicit criteria for potentially inappropriate medications (PIMs) in frailer older adults with limited life expectancy. A Delphi consensus survey of an expert panel (n = 17) comprising specialists in geriatric medicine, clinical pharmacology, palliative care, psychiatry of old age, clinical pharmacy and general practice.
Methods: STOPPFrail criteria was initially created by the authors based on clinical
experience and appraisal of the available literature. Criteria were organised according to physiological system. Each criterion was accompanied by an explanation. Panellists ranked their agreement with each criterion on a 5-point Likert scale and invited to provide written feedback. Criteria with a median Likert response of 4/5 (agree/strongly agree) and a 25th centile of ≥4 were included in the final criteria.
Results: Three Delphi rounds were required. All panellists completed all rounds. Thirty criteria were proposed for inclusion; 26 were accepted. No new criteria were added. The first two criteria suggest deprescribing medications with no indication or where compliance is poor. The remaining 24 criteria include lipid-lowering therapies, alpha-blockers for hypertension, anti-platelets, neuroleptics, proton pump inhibitors, H-2 receptor antagonists, anti-spasmodics, theophylline, leukotriene antagonists, calcium supplements, bone anti-resorptive therapy, selective oestrogen receptor modulators, non-steroidal antiinflammatories, corticosteroids, 5-alpha reductase inhibitors, alpha-1 selective blockers, muscarinic antagonists, oral diabetic agents, ACE-inhibitors, angiotensin receptor blockers, systemic oestrogens, multivitamins, nutritional supplements and prophylactic antibiotics. Anticoagulants and anti-depressants were excluded. Despite incorporation of panellists’ suggestions, memantine and acetyl-cholinesterase inhibitors remained inconclusive.
Conclusion: STOPPFrail comprises 26 criteria, which have been judged by broad consensus, to be potentially inappropriate in frailer older patients with limited life expectancy. STOPPFrail may assist in deprescribing medications in these patients.

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Chapter 1 While targeting kinases in oncology research has been explored extensively, targeting protein phosphatases is currently in its infancy. However, a number of pharmaceutical companies are currently looking to expand their research efforts in this area. PP2A has been shown to down-regulate ERK5, a mitogen-activated protein kinase (MAPK) that has been shown to be important in driving the invasive phenotype of prostate cancer. Fostriecin and its related structural analogues PD 113,270 and 113,271 have been shown to inhibit a mitotic entry checkpoint in cell growth through the potent and selective inhibition of protein phosphatases PP1, PP2A, and PP4 (IC50 of 45 μM, 1.5 nM, and 3 nM respectively). Fostriecin is one of the most selective protein phosphatase inhibitors disclosed to date with a 104 fold selectivity for PP2A/PP4 versus PP1. Unfortunately, fostriecin and its analogues are very unstable, and this instability has effectively prevented them from being used as effective therapeutic leads. The microcystins and nodularins on the other hand, exhibit significant inhibitory activity against PP1 and PP2A (IC50 = 26 pM and 1.8 nM respectively), but their high toxicity has prevented any therapeutic application. Truncation of the ADDA chain from these polypeptides completely attenuates PP inhibitory activity. Simpler analogues incorporating the N-acylated ADDA chain and D-Ala retain moderate activity against PP1 and PP2A (IC50 = 1.0 μM and 0.17 μM respectively). The generation of a new series of fostriecin analogues to further expand its structure-activity relationship is envisaged with a view to creating new more stable PP2A inhibitors. It was hoped that by incorporating some of the more stable structural features of ADDA into fostriecin that stability and activity could be reconciled. With that in mind a series of PP2A inhibitors were synthesised and biologically evaluated. Chapter 2 GPCRs are an important area of research and are the targets of a quarter of the drugs on the market (2005). As a result, GPCRs continue to be at the forefront of research in both small and large drug companies. However one of the difficulties in studying this diverse class of membrane proteins is their tendency to denature in aqueous solution. As a result there is a pressing need to develop new detergents to solubilise, stabilise and crystallise GPCRs in their native form for further study. Cholesterol analogues have been shown to be important for stabilising membrane proteins and preventing their thermal inactivation. In addition the β2-adrenergic receptor, a GPCR membrane protein, has been crystallised in the active state with two cholesterol molecules bound between the I, II, III and IV helices of the protein. This appears to represent a distinct cholesterol binding pocket on the membrane protein that is speculated to be conserved across up to 44% of the rhodopsin class of GPCRs. CHOBIMALT is a cholesterol-based detergent that has been shown to exhibit promising GPCR-stabilising properties. When benchmarked against other cholesterol based detergents it was found to be superior to all others tested except for cholesteryl hemisuccinate.1 CHOBIMALT has an aggregation number of roughly 200 and forms 210 ± 30 kDa micelles, which are significantly larger than those of most detergents used for biological systems which is likely due to the packing constraints associated with CHOBMALT’s large polar headgroup.2 As a result, CHOBIMALT is used mostly as an additive to other commercially available detergents in order to decrease micelle size. A branched dimaltoside motif is common in recently synthesised detergents by Chae and co-workers. These detergents have shown promising detergent properties, for example the maltose neopentyl glycol (MNG) detergent synthesised by Chae. This branched dimaltoside detergent was shown to be able to solubilise and stabilise the very labile light harvesting complex I (LHI) from Rhodopsin capsulatus in its active form for 20 days with little loss of protein conformation.3 A cholesterol-based detergent was envisaged that combines the cholesterol framework of CHOBIMALT but replaces its linear tetrasaccharide with a branched dimaltoside. This detergent would then be investigated to assess its ability to solubilise, stabilise and crystallise GPCR proteins. This cholesterol-based detergent (shown below) was eventually synthesised in 9 linear steps from cholesterol.

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In the present study, the effects of Polybia paulista venom (PPV) on renal and vascular tissues were investigated. Isolated kidneys perfused with PPV (1 and 3 mu g/mL) had increased perfusion pressure, renal vascular resistance, urinary flow, and glomerular filtration rate; and reduced sodium tubular transport. Histological evaluation demonstrated deposits of proteins in Bowman's space and tubular lumen, and focal areas of necrosis. The venom promoted a cytotoxic effect on Madin-Darby canine kidney (MDCK) cells. A significant increase in lactic dehydrogenase levels was observed in response to venom exposure. In isolated mesenteric vascular beds, pressure and vascular resistance augmented in a dose-dependent manner. PPV increased the contractility of aortic rings maintained under basal tension. This contractile response was inhibited when preparations were maintained in Ca2+-free medium. Likewise, verapamil, a voltage-gated calcium channel blocker, also inhibited the contractile response. In this study, phentolamine, a blocker of a-adrenergic receptor blocker, significantly reduced the contractile effect of PPV in the aortic ring. In conclusion, PPV produced nephrotoxicity, which suggests a direct effect on necrotic cellular death in renal tubule cells. The vascular contractile effect of PPV appears to involve calcium influx through voltage-gated calcium channels via adrenergic regulation.

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BACKGROUND Anaplasma phagocytophilum infects a wide variety of hosts and causes granulocytic anaplasmosis in humans, horses and dogs and tick-borne fever in ruminants. Infection with A. phagocytophilum results in the modification of host gene expression and immune response. The objective of this research was to characterize gene expression in pigs (Sus scrofa) naturally and experimentally infected with A. phagocytophilum trying to identify mechanisms that help to explain low infection prevalence in this species. RESULTS For gene expression analysis in naturally infected pigs, microarray hybridization was used. The expression of differentially expressed immune response genes was analyzed by real-time RT-PCR in naturally and experimentally infected pigs. Results suggested that A. phagocytophilum infection affected cytoskeleton rearrangement and increased both innate and adaptive immune responses by up regulation of interleukin 1 receptor accessory protein-like 1 (IL1RAPL1), T-cell receptor alpha chain (TCR-alpha), thrombospondin 4 (TSP-4) and Gap junction protein alpha 1 (GJA1) genes. Higher serum levels of IL-1 beta, IL-8 and TNF-alpha in infected pigs when compared to controls supported data obtained at the mRNA level. CONCLUSIONS These results suggested that pigs are susceptible to A. phagocytophilum but control infection, particularly through activation of innate immune responses, phagocytosis and autophagy. This fact may account for the low infection prevalence detected in pigs in some regions and thus their low or no impact as a reservoir host for this pathogen. These results advanced our understanding of the molecular mechanisms at the host-pathogen interface and suggested a role for newly reported genes in the protection of pigs against A. phagocytophilum.

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Sphingosine 1-phosphate receptor 1 (S1PR1) is a G-protein-coupled receptor for sphingosine-1-phosphate (S1P) that has a role in many physiological and pathophysiological processes. Here we show that the S1P/S1PR1 signalling pathway in hypothalamic neurons regulates energy homeostasis in rodents. We demonstrate that S1PR1 protein is highly enriched in hypothalamic POMC neurons of rats. Intracerebroventricular injections of the bioactive lipid, S1P, reduce food consumption and increase rat energy expenditure through persistent activation of STAT3 and the melanocortin system. Similarly, the selective disruption of hypothalamic S1PR1 increases food intake and reduces the respiratory exchange ratio. We further show that STAT3 controls S1PR1 expression in neurons via a positive feedback mechanism. Interestingly, several models of obesity and cancer anorexia display an imbalance of hypothalamic S1P/S1PR1/STAT3 axis, whereas pharmacological intervention ameliorates these phenotypes. Taken together, our data demonstrate that the neuronal S1P/S1PR1/STAT3 signalling axis plays a critical role in the control of energy homeostasis in rats.

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Pectic substances are structural heteropolysaccharides that occur in the middle lamellae and primary cell walls of higher plants. They are composed of partially methyl-esterified galacturonic acid residues linked by alpha-1, 4-glycosidic bonds. Pectinolytic enzymes are complex enzymes that degrade pectic polymers and there are several classes of enzymes, which include pectin esterases, pectin and pectate lyases and polygalacturonases. Plants, filamentous fungi, bacteria and yeasts are able to produce pectinases. In the industrial world, pectinases are used in fruit juice clarification, in the production of wine, in the extraction of olive oil, fiber degumming and fermentation of tea, coffee and cocoa.

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A case-control study was carried out in litters of 1 to 7-day-old piglets to identify the main infectious agents involved with neonatal diarrhea in pigs. Fecal samples (n=276) from piglets were collected on pig farms in the State of Rio Grande do Sul, Brazil, from May to September 2007. Litters with diarrhea were considered cases (n=129) and normal litters (n=147) controls. The samples were examined by latex agglutination test, PAGE, conventional isolating techniques, ELISA, PCR, and microscopic methods in order to detect rotavirus, bacterial pathogens (Escherichia coli, Clostridium perfringens type A and C, and Clostridium difficile), and parasites (Coccidian and Cryptosporidium spp.). Outbreaks of diarrhea were not observed during sampling. At least one agent was detected in fecal samples on 25 out of 28 farms (89.3%) and in 16 farms (57.1%) more than one agent was found. The main agents diagnosed were Coccidia (42.86%) and rotavirus (39.29%). The main agents identified in litters with diarrhea were Clostridium difficile (10.6%), Clostridium perfringens type A (8.8%) and rotavirus (7.5%); in control litters, Clostridium difficile (16.6%) and Coccidian (8.5%). Beta hemolytic Escherichia coli and Clostridium perfringens type C were not detected. When compared with controls, no agent was significantly associated with diarrhea in case litters. These findings stress the need for caution in the interpretation of laboratorial diagnosis of mild diarrhea in neonatal pigs, as the sole detection of an agent does not necessarily indicate that it is the cause of the problem.

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Temperature-dependent electrical resistance in quasi-one-dimensional Li(0.9)Mo(6)O(17) is described by two Luttinger liquid anomalous exponents alpha, each associated with a distinct one dimensional band. The band with alpha < 1 is argued to crossover to a higher dimension below the temperature T(M'), leading to superconductivity. Disorder and magnetic fields are shown to induce the Bose metal behavior in this bulk compound.

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We consider distributions u is an element of S'(R) of the form u(t) = Sigma(n is an element of N) a(n)e(i lambda nt), where (a(n))(n is an element of N) subset of C and Lambda = (lambda n)(n is an element of N) subset of R have the following properties: (a(n))(n is an element of N) is an element of s', that is, there is a q is an element of N such that (n(-q) a(n))(n is an element of N) is an element of l(1); for the real sequence., there are n(0) is an element of N, C > 0, and alpha > 0 such that n >= n(0) double right arrow vertical bar lambda(n)vertical bar >= Cn(alpha). Let I(epsilon) subset of R be an interval of length epsilon. We prove that for given Lambda, (1) if Lambda = O(n(alpha)) with alpha < 1, then there exists epsilon > 0 such that u vertical bar I(epsilon) = 0 double right arrow u 0; (2) if Lambda = O(n) is uniformly discrete, then there exists epsilon > 0 such that u vertical bar I(epsilon) = 0 double right arrow u 0; (3) if alpha > 1 and. is uniformly discrete, then for all epsilon > 0, u vertical bar I(epsilon) = 0 double right arrow u = 0. Since distributions of the above mentioned form are very common in engineering, as in the case of the modeling of ocean waves, signal processing, and vibrations of beams, plates, and shells, those uniqueness and nonuniqueness results have important consequences for identification problems in the applied sciences. We show an identification method and close this article with a simple example to show that the recovery of geometrical imperfections in a cylindrical shell is possible from a measurement of its dynamics.

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Galectin-3 is a beta-galactoside-binding protein that has been shown to regulate pathophysiological processes, including cellular activation, differentiation and apoptosis. Recently, we showed that galectin-3 acts as a potent inhibitor of B cell differentiation into plasma cells. Here, we have investigated whether galectin-3 interferes with the lymphoid organization of B cell compartments in mesenteric lymph nodes (MLNs) during chronic schistosomiasis, using WT and galectin-3(-/-) mice. Schistosoma mansoni synthesizes GalNAc beta 1-4(Fuc alpha 1-3) GlcNAc(Lac-DiNAc) structures (N-acetylgalactosamine beta 1-4 N-acetylglucosamine), which are known to interact with galectin-3 and elicit an intense humoral response. Antigens derived from the eggs and adult worms are continuously drained to MLNs and induce a polyclonal B cell activation. In the present work, we observed that chronically-infected galectin-3(-/-) mice exhibited a significant reduced amount of macrophages and B lymphocytes followed by drastic histological changes in B lymphocyte and plasma cell niches in the MLNs. The lack of galectin-3 favored an increase in the lymphoid follicle number, but made follicular cells more susceptible to apoptotic stimuli. There were an excessive quantity of apoptotic bodies, higher number of annexin V(+)/PI(-) cells, and reduced clearance of follicular apoptotic cells in the course of schistosomiasis. Here, we observed that galectin-3 was expressed in nonlymphoid follicular cells and its absence was associated with severe damage to tissue architecture. Thus, we convey new information on the role of galectin-3 in regulation of histological events associated with B lymphocyte and plasma cell niches, apoptosis, phagocytosis and cell cycle properties in the MLNs of mice challenged with S. mansoni.

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In this work, we demonstrate field-induced Bose-Einstein condensation (BEC) in the organic compound NiCl(2)-4SC(NH(2))(2) using ac susceptibility measurements down to 1 mK. The Ni S=1 spins exhibit 3D XY antiferromagnetism between a lower critical field H(c1)similar to 2 T and a upper critical field H(c2)similar to 12 T. The results show a power-law temperature dependence of the phase transition line H(c1)(T)-H(c1)(0)=aT(alpha) with alpha=1.47 +/- 0.10 and H(c1)(0)=2.053 T, consistent with the 3D BEC universality class. Near H(c2), a kink was found in the phase boundary at approximately 150 mK.

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In this paper we determine the local and global resilience of random graphs G(n,p) (p >> n(-1)) with respect to the property of containing a cycle of length at least (1 - alpha)n. Roughly speaking, given alpha > 0, we determine the smallest r(g) (G, alpha) with the property that almost surely every subgraph of G = G(n,p) having more than r(g) (G, alpha)vertical bar E(G)vertical bar edges contains a cycle of length at least (1 - alpha)n (global resilience). We also obtain, for alpha < 1/2, the smallest r(l) (G, alpha) such that any H subset of G having deg(H) (v) larger than r(l) (G, alpha) deg(G) (v) for all v is an element of V(G) contains a cycle of length at least (1 - alpha)n (local resilience). The results above are in fact proved in the more general setting of pseudorandom graphs.

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This paper is a continuation and a complement of our previous work on isomorphic classification of some spaces of compact operators. We improve the main result concerning extensions of the classical isomorphic classification of the Banach spaces of continuous functions on ordinals. As an application, fixing an ordinal a and denoting by X(xi), omega(alpha) <= xi < omega(alpha+1), the Banach space of all X-valued continuous functions defined in the interval of ordinals [0,xi] and equipped with the supremum, we provide complete isomorphic classifications of some Banach spaces K(X(xi),Y(eta)) of compact operators from X(xi) to Y(eta), eta >= omega. It is relatively consistent with ZFC (Zermelo-Fraenkel set theory with the axiom of choice) that these results include the following cases: 1.X* contains no copy of c(0) and has the Mazur property, and Y = c(0)(J) for every set J. 2. X = c(0)(I) and Y = l(q)(J) for any infinite sets I and J and 1 <= q < infinity. 3. X = l(p)(I) and Y = l(q)(J) for any infinite sets I and J and 1 <= q < p < infinity.

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Many therapeutic agents are commercialized under their racemic form. The enantiomers can show differences in the pharmacokinetic and pharmacodynamic profile. The use of a pure enantiomer in pharmaceutical formulations may result in a better therapeutic index and fewer adverse effects. Atropine, an alkaloid of Atropa belladonna, is a racemic mixture of l-hyoscyamine and d-hyoscyamine. It is widely used to dilate the pupil. To quantify these enantiomers in ophthalmic solutions, an HPLC method was developed and validated using a Chiral AGP (R) column at 20 degrees C. The mobile phase consisted of a buffered phosphate solution (containing 10 mM 1-octanesulfonic acid sodium salt and 7.5 mM triethylamine, adjusted to pH 7.0 with orthophosphoric acid) and acetonitrile (99 + 1, v/v). The flow rate was 0.6 mL/min, with UV detection at 205 nm. In the concentration range of 14.0-26.0 mu g/mL, the method was found to be linear (r > 0.9999), accurate (with recovery of 100.1-100.5%), and precise (RSD system: <= 0.6%; RSD intraday: <= 1.1%; RSD interday: <= 0.9%). The method was specific, and the standard and sample solutions were stable for up to 72 h. The factorial design assures robustness with a variation of +/-10% in the mobile phase components and 2 degrees C of column temperature. The complete validation, including stress testing and factorial design, was studied and is presented in this research.

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Sibutramine hydrochloride monohydrate, chemically 1-(4-chlorophenyl)-N,N-dimethyl-alpha-(2-methylpropyl) hydrochloride monohydrate (SB center dot HCl center dot H2O), was approved by the U.S. Food and Drug Administration for the treatment of obesity. The objective of this study was to develop, validate, and compare methods using UV-derivative spectrophotometry (UVDS) and reversed-phase high-performance liquid chromatography (HPLC) for the determination of SB center dot HCl center dot H2O in pharmaceutical drug products. The UVDS and HPLC methods were found to be rapid, precise, and accurate. Statistically, there was no significant difference between the proposed UVDS and HPLC methods. The enantiomeric separation of SB was obtained on an alpha-1 acid glycoprotein column. The R- and S-sibutramine were eluted in < 5 min with baseline separation of the chromatographic peaks (alpha = 1.9 and resolution = 1.9).