27 resultados para BON-28-AI

em QUB Research Portal - Research Directory and Institutional Repository for Queen's University Belfast


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Piclavines AI and A2 have been synthesised for the first time. The route is short with the key step being the reaction of a bicyclic N-acyl iminium ion with 3-trimethysilyl-1-decene. This convergent strategy gave exclusively compounds in which the pendant decenyl group was axial, as a 6:1 mixture of E:Z-alkene diastereoisomers. Reduction of the lactam carbonyl group gave a 6:1 mixture of piclavines Al and A2, (C) 2000 Published by Elsevier Science Ltd.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Skin kininogens from bombinid toads encode an array of bradykinin-related peptides and one such kininogen from Bombina maxima also encodes the potent bradykinin B2-receptor antagonist, kinestatin. In order to determine if the skin secretion of the closely-related toad, Bombina orientalis, contained a bradykinin inhibitory peptide related to kinestatin, we screened reverse phase HPLC fractions of defensive skin secretion using a rat tail artery smooth muscle preparation. A fraction was located that inhibited bradykinin-induced relaxation of the preparation and this contained a peptide of 3198.5 Da as determined by MALDI-TOF MS. Automated Edman degradation of this peptide established the identity of a 28-mer as: DMYEIKGFKSAHGRPRVCPPGEQCPIWV, with a disulfide-bridge between Cys18 and Cys24 and an amidated C-terminal Val residue. Peptide DV-28 was found to correspond to residues 133–160 of skin pre-kininogen-2 of B. orientalis that also encodes two copies of (Thr6)-bradykinin. The C-terminal residue, Gly-161, of the precursor open-reading frame, acts as the C-terminal amide donor of mature DV-28. DV-28 amide thus represents a new class of bradykinin inhibitor peptide from amphibian skin secretion.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Kinestatin, isolated from the skin of the Chinese toad, Bombina maxima, was the first bradykinin B2 receptor antagonist identified in amphibians. Molecular cloning established that it is co-encoded with the bradykinin-related peptide, maximakinin, within one of several skin kininogens. To examine other species within the genus Bombina for the presence of structural homologues of kinestatin, we subjected skin secretion of the toad, Bombina orientalis, to HPLC fractionation with subsequent bioassay of fractions for antagonism of bradykinin activity using an isolated rat tail artery smooth muscle preparation. A single fraction was located that inhibited bradykinin-induced relaxation of rat arterial smooth muscle and MALDI-TOF analysis of this fraction revealed that it contained a single peptide of molecular mass 3198.5 Da. Further primary structural analysis of this peptide showed that it was a 28-mer with an N-terminal Asp (D) residue and a C-terminal Val (V) residue that was amidated. The peptide was named DV-28 amide in accordance with these primary structural attributes. Synthetic DV-28 amide replicated the observed bradykinin antagonistic effect within the smooth muscle bioassay in a dose-dependent manner. In addition, it was observed to inhibit the proliferation of human microvessel endothelial cells (HMECs) as assessed by MTT assay. Bioinformatic analysis revealed that DV-28 amide was, like kinestatin, co-encoded with a bradykinin receptor agonist on one of two skin kininogens identified in B. orientalis. DV-28 amide thus represents a novel class of bradykinin antagonist from skin secretions of bombinid toads that appear to be a rich source of such novel peptides.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

OBJECTIVE:Diabetes during pregnancy is a strong risk factor for obesity in the offspring, but the age at which this association becomes apparent is unknown. The purpose of this study was to examine the relation of glycemia during pregnancy with anthropometry in offspring of nondiabetic pregnant women from the Belfast U.K. center of the multinational Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study.
RESEARCH DESIGN AND METHODS: Women from the HAPO Study were invited to participate in follow-up of their offspring aged 2 years. Measurements included height, weight, and thickness of triceps, subscapular, and suprailiac skinfolds. RESULTS: A total of 1,165 offspring (73% of eligible children; 598 boys and 567 girls) were seen from ages 22-30 completed months. The only association that reached statistical significance was between categories of maternal 1-h glucose and BMI Z score =85th percentile at 2 years (P = 0.017). Overall the correlations between maternal glucose during pregnancy and BMI Z score at age 2 years were weak (fasting glucose r = 0.05, P = 0.08; 1-h glucose r = 0.04, P = 0.22; 2-h glucose r = 0.03, P = 0.36; and area under the curve for glucose r = 0.04, P = 0.18).
CONCLUSIONS: This study found little association between maternal glucose during pregnancy and obesity in the offspring at this young age. These findings are not unexpected given that study results for young offspring whose mothers had diabetes during pregnancy were indistinguishable from those for normal offspring at this age. It will be interesting to see whether, as these children age, maternal glucose during pregnancy in the ranges included in the HAPO Study will be associated with obesity in their children. © 2010 by the American Diabetes Association.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The end of the Occupation, which was much more violent than its beginning, dramatically affected the overall perception of Germans and Germany for many years in post-WWII France. This vision is of course reflected to a large extent in French literature. Yet, paradoxically, many novels—including the ‘best-sellers’ E ´ ducation europe´enne (1945) by Romain Gary, Mon Village a` l’heure allemande (1945) by Jean-Louis Bory or Les Foreˆts de la nuit (1947) by Jean-Louis Curtis—contain a ‘good German’ character. Firstly, this article will give an overview of the dominant representations of Germans in post-WWII France, before suggesting that the ‘good German’ character follows both a literary tradition and the humanist values of the French Resistance, to which these writers claim to subscribe. Finally, it will show how this character, far from blurring the Manichean ideology of the novel in which he appears, actually reinforces it.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Agricultural intensification can affect biodiversity and related ecosystem services such as biological control, but large-scale experimental evidence is missing. We examined aphid pest populations in cereal fields under experimentally reduced densities of (1) ground-dwelling predators (-G), (2) vegetation-dwelling predators and parasitoids (-V), (3) a combination of (1) and (2) (-G-V),compared with open-fields (control), in contrasting landscapes with low vs. high levels of agricultural intensification (AI), and in five European regions. Aphid populations were 28%, 97%, and 199% higher in -G, -V, and -G -V treatments, respectively, compared to the open fields, indicating synergistic effects of both natural-enemy groups. Enhanced parasitoid : host and predator : prey ratios were related to reduced aphid population density and population growth. The relative importance of parasitoids and vegetation-dwelling predators greatly differed among European regions, and agricultural intensification affected biological control and aphid density only in some regions. This shows a changing role of species group identity in diverse enemy communities and a need to consider region-specific landscape management.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We examined the association between workplace social capital and all-cause mortality in a large occupational cohort from Finland.