919 resultados para vitamin B-1


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Palladium and platinum complexes of pyridoxamine, pyridoxine and pyridoxal have been prepared. The structures of the complexes PtCI2PM.H20, trans-PdC12 (PN)2 and [PLH+ ]2[PtC16] 2- ,H20 have been determined by use of single crystal x-ray studies. The compounds PdC12PH, trans-PdC12 (PN) 2 , cis-PdCI2 (PN)2 and cis PdC12 (PL)2 were also studied by use of carbon-13 nmr spectroscopy. All the complexes have also been characterised by use of infrared spectral studies. In the complexes, PtCI2PM.H20 and PdC12PM, the ligand pyridoxamine is chela ted to the metal through the aminomethyl nitrogen and the phenolate oxygen atoms whereas in the complexes, trans-PdCI2 (PN)2' cis-PdCI2 (PN)2 and cis-PdC12 (PL)2 the vitamin B6 ligands are coordinated to the metal through the pyridine ring nitrogen. The compounds [PLH+ ]2[PtCI6] 2- .H20 and [PMH2] 2+ [PdCI4] 2- .H20have no direct metal-ligand bonding, In all the complexes, the metal maintains a square planar coordination except in [PLH +] 2[PtCI6] 2- ,H20 where the metal is octahedrally coordinated. PH pyridoxamine [PMH ] 2+ = diprotonated pyridoxamine 2 PN = pyridoxine PL pyridoxal PLH+ protonated pyridoxal

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El ejemplar con signatura 42827 es de 1993

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Relaxing action of sodium nitroprusside (SNP) was significantly reduced in the stomach fundus of mice lacking the kinin B(1) receptor (B(1)(-/-)). Increased basal cGMP accumulation was correlated with attenuated SNP induced dose-dependent relaxation in B(1)(-/-) when compared with wild type (WT) control mice. These responses to SNP were completely blocked by the guanylate cyclase inhibitor ODQ(10 mu M). It was also found that Ca(2+)-dependent, constitutive nitric oxide synthase (cNOS) activity was unchanged but the Ca(2+)-independent inducible NOS (iNOS) activity was greater in B(1)(-/-) mice than in WT animals. Zaprinast (100 mu M), a specific phosphodiesterase inhibitor, increased the nitrergic relaxations and the accumulation of the basal as well as the SNP-stimulated cGMP in WT but not in B(1)(-/-) stomach fundus. From these findings it is concluded that the inhibited phosphodiesterase activity and high level of cGMP reduced the resting muscle tone, impairing the relaxant responses of the stomach in B(1)(-/-) mice. In addition, it can be suggested that functional B(2) receptor might be involved in the NO compensatory mechanism associated with the deficiency of kinin B(1) receptor in the gastric tissue of the transgenic mice. (C) 2009 Elsevier Inc. All rights reserved.

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In the present study the effects of bradykinin receptor antagonists were investigated in a murine model of asthma using BALB/c mice immunized with ovalbumin/alum and challenged twice with aerosolized ovalbumin. Twenty four hours later eosinophil proliferation in the bone marrow, activation (lipid bodies formation), migration to lung parenchyma and airways and the contents of the pro-angiogenic and pro-fibrotic cytokines TGF-beta and VEGF were determined. The antagonists of the constitutive B(2) (HOE 140) and inducible B(1) (R954) receptors were administered intraperitoneally 30 min before each challenge. In sensitized mice, the antigen challenge induced eosinophil proliferation in the bone marrow, their migration into the lungs and increased the number of lipid bodies in these cells. These events were reduced by treatment of the mice with the B(1) receptor antagonist. The B(2) antagonist increased the number of eosinophils and lipid bodies in the airways without affecting eosinophil counts in the other compartments. After challenge the airway levels of VEGF and TGF-beta significantly increased and the B(1) receptor antagonist caused a further increase. By immunohistochemistry techniques TGF-beta was found to be expressed in the muscular layer of small blood vessels and VEGF in bronchial epithelial cells. The B(1) receptors were expressed in the endothelial cells. These results showed that in a murine model of asthma the B(1) receptor antagonist has an inhibitory effect on eosinophils in selected compartments and increases the production of cytokines involved in tissue repair. It remains to be determined whether this effects of the B(1) antagonist would modify the progression of the allergic inflammation towards resolution or rather towards fibrosis. (C) 2009 Elsevier Ltd. All rights reserved.

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The aim of this study was to determine the clinical, pathological and mycotoxicological effects of oral administration of fumonisin B, (FBI) in rabbits. Eighteen rabbits were randomly assigned to two experimental groups: control group, 0 mg FB(1): fumonisin group. 31.5 mg FB(1)/kg body weight, corresponding to about 630 mg FB(1)/kg diet. Fumonisin administered as a single oral dose to rabbits resulted in acute toxicity, significantly interfering with body and liver weight. Serum biochemical analysis revealed a significant increase of total protein, alkaline phosphatase (AP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), urea and creatinine in the group receiving FBI compared to control animals, a finding characterizing hepatic and renal injury in this group. Urinary protein concentrations were markedly elevated at 12,24,48 and 72 h after dosing, although visible pathological abnormalities were not observed, probably because of rapid repair of the damage. FBI was detected in feces, with a maximum concentration at 24h after administration, indicating that the enterohepatic circulation is important in rabbits. FBI concentrations found in urine were low, with peak elimination at 12 h after intoxication. The highest FBI concentrations were observed in feces compared to urine and liver, demonstrating that feces are the main routes of excretion. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

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Objetivo: determinar a viabilidade da identificação do linfonodo-sentinela em pacientes com câncer invasor de colo uterino estádio Ib1. Material e Métodos: 16 pacientes consecutivas com câncer de colo uterino agendadas para histerectomia radical com linfadenectomia pélvica bilateral realizaram estudo para detecção de linfonodo-sentinela. Onze pacientes injetaram 1 mCi de tecnécio 99 (99Tc) em quatro pontos do estroma superficial do colo uterino ao redor do tumor, às 12, 3, 6 e 9 h ( 16 horas antes da cirurgia ). No dia da cirurgia, as pacientes foram submetidas ao mapeamento linfático com gamma-probe e azul patente injetado nos mesmos pontos que o 99Tc.Cinco pacientes realizaram a detecção apenas com azul patente. Resultados: foi detectado pelo menos um (1 a 3 por paciente) linfonodo-sentinela em cada uma das 15 pacientes (93,7 %) que realizaram a técnica combinada.Foi detectado pelo menos 1 linfonodo-sentinela em 4 pacientes ( 80% )com azul patente apenas. A maioria dos linfonodos-sentinela foi localizada nas regiões: obturadora (37 %), ilíaca externa (22,2 %) e inter-ilíacas (18,5 %). Seis pacientes (40 %) tiveram linfonodos-sentinela bilaterais. Dos 27 linfonodos-sentinela detectados, 11 (40,7 %) foram detectados pelo corante, 9 (33,3%) pela radioatividade e 7 (26 %) pela radioatividade e corante. O índice de detecção intra-operatória com o gamma-probe foi de 90,9 % ( 11 pacientes ). Destes, 7 linfonodos foram azul e quente (31,8 %), 6 linfonodos foram apenas azuis (27,2 %) e 9 linfonodos foram apenas quentes (40,9 %). A sensibilidade, especificidade e valor preditivo negativo para a detecção do linfonodo-sentinela foram 100%, 85,7 % e 100 % respectivamente. Conclusão: A combinação do radiofármaco 99Tc e azul patente é efetiva na detecção do linfonodosentinela em câncer de colo uterino inicial.

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

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Calculation for the electronic excitation of the ground state of H-2 to B (1) Sigma(u)(+) and b(3) Sigma(u)(+) states by positronium- (Ps) atom impact has been carried out using the first Born approximation considering discrete Ps excitations up to n = 6 and Ps ionization in the final state. To include the effect of electron exchange, we propose an alternative approximation scheme in the light of the Rudge approach, which takes into account the composite nature of the Ps-atom projectile.

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This Letter presents the first strong evidence for the resolution of the excited B mesons B-1 and B-2(*) as two separate states in fully reconstructed decays to B+(*())pi(-). The mass of B-1 is measured to be 5720.6 +/- 2.4 +/- 1.4 MeV/c(2) and the mass difference Delta M between B-2* and B-1 is 26.2 +/- 3.1 +/- 0: 9 MeV/c(2), giving the mass of the B-2* as 5746.8 +/- 2.4 +/- 1.7 MeV/c(2). The production rate for B-1 and B-2* mesons is determined to be a fraction (13.9 +/- 1.9 +/- 3.2)% of the production rate of the B+ meson.

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The effects of prolonged oral administration (21 days) of fumonisin B(1) (FB(1)) and aflatoxin B(1) (AFB(1)) were evaluated on male Wistar rats. The animals were housed in individual metabolic cages and submitted to the following treatments: 1-0 mug AFB(1) + 0 mg FB(1)/100g bw.; 2-72 mug AFB(1)+ 0 mg FB(1)/100 g bw; 3-0 mug AFB(1) + 0.5 mg FB(1) g bw; 4-0 mug AFB(1) + 1.5 mg FB(1)/100 g bw; 5-72 mug AFB(1) + 0.5 mg FB(1)/100g bw; 6-72 mu gAFB(1) + 1.5 mg FB(1)/100g bw. on day 21, the rats were sacrificed for evaluation. The results showed that treated animals presented differences in body weight and absolute/relative weights of liver and kidney as well as altered hepatic function and cholesterol blood levels. Rats fed with the greatest doses of AFB(1) and FB(1) gained less weight (2.79 g/day) at the end of the experimental period; their blood concentrations of liver enzymes aspartate aminotransferase (AST) and alkaline phosphatase (AP) were above control levels (130.35 mu /l and 471.00 mu /l, respectively). Blood cholesterol increased in the groups treated with the highest dose of FB(1) or FB(1) associated with AFB(1). Histopathology revealed the occurrence of apoptosis in the liver of rats exposed to FB(1). The association of aflatoxin B(1) with fumonisin B(1) at higher dose probably potentiated the effects of the higher dose of fumonisin B(1)acting singly.

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As demonstrated previously in our laboratory, B-1 cells migrate from the peritoneal cavity of mice and home to a distant site of inflammation to become macrophage-like cells. However, the influence that these cells might have on the kinetics and fate of the inflammatory process is not known. Considering that macrophages are pivotal in the inflammatory reaction, we decided to investigate the possible influence B-1 cells could have on macrophage activities in vitro. Our results show that peritoneal macrophages from Xid mice, a mouse strain deprived of B-1 cells, have higher phagocytic indexes for zymozan particles when compared with macrophages from wild-type mice. Moreover, macrophages from wild-type mice have a lower ability to release nitric oxide and hydrogen peroxide when compared with macrophages from Xid mice. Experiments using cocultures of B-1 cells and macrophages from Xid mice in transwell plates demonstrated that B-1 cells down-regulate macrophage activities. These observations also indicate that this phenomenon is not due to a physical interaction between these two cell populations. As B-1 cells are one of the main sources of interleukin (IL)-10, we demonstrate in this study that adherent peritoneal cells from Xid mice produce significantly less amounts of this cytokine in culture when compared with IL-10 production by cells from wild-type mice. When B-1 cells from IL-10 knock-out mice and macrophages from wild-type mice were cocultured in transwell plates, the phagocytic index of macrophages was not altered demonstrating that B-1 cells can influence the effector functions of macrophages in vitro via IL-10 secretion.

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Background and Purpose Bone resorption induced by interleukin-1β (IL-1β) and tumour necrosis factor (TNF-α) is synergistically potentiated by kinins, partially due to enhanced kinin receptor expression. Inflammation-induced bone resorption can be impaired by IL-4 and IL-13. The aim was to investigate if expression of B1 and B2 kinin receptors can be affected by IL-4 and IL-13. Experimental Approach We examined effects in a human osteoblastic cell line (MG-63), primary human gingival fibroblasts and mouse bones by IL-4 and IL-13 on mRNA and protein expression of the B1 and B2 kinin receptors. We also examined the role of STAT6 by RNA interference and using Stat6-/- mice. Key Results IL-4 and IL-13 decreased the mRNA expression of B1 and B2 kinin receptors induced by either IL-1β or TNF-α in MG-63 cells, intact mouse calvarial bones or primary human gingival fibroblasts. The burst of intracellular calcium induced by either bradykinin (B2 agonist) or des-Arg10-Lys-bradykinin (B1 agonist) in gingival fibroblasts pretreated with IL-1β was impaired by IL-4. Similarly, the increased binding of B1 and B2 ligands induced by IL-1β was decreased by IL-4. In calvarial bones from Stat6-deficient mice, and in fibroblasts in which STAT6 was knocked down by siRNA, the effect of IL-4 was decreased. Conclusions and Implications These data show, for the first time, that IL-4 and IL-13 decrease kinin receptors in a STAT6-dependent mechanism, which can be one important mechanism by which these cytokines exert their anti-inflammatory effects and impair bone resorption. © 2013 The Authors. British Journal of Pharmacology © 2013 The British Pharmacological Society.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)