156 research outputs found
Allylsulfones through Palladium-Catalyzed Allylic CâH Sulfonylation of Terminal Alkenes
Two previously unknown protocols for Pd-catalyzed allylic C-H sulfonylation of terminal alkenes have been developed. While the former consists of a direct Pd(II)-catalyzed oxidative C-H allylic sulfonylation in the presence of sulfinate anions, the latter involves a sequential one-pot Pd(II)-catalyzed C-H allylic acetoxylation followed by a Pd(0)-catalyzed sulfonylation. The scope of both protocols was studied on 25 examples
Cellular localisation of VvRops and VvRabA5e, small GTPases developmentally regulated in grape berries
VvRops, in particular VvRop9, and VvRabA5e are small GTPases which are developmentally regulated in grape berries. In an attempt to help elucidate the role of these proteins during fruit development and ripening, we investigated their localisation in the fruit by immunocytofluorescence. These proteins were observed at a perinuclear location, at cell periphery and around vesicles. In particular VvRops were found to be located in the nucleus and likely on the plasma membrane. VvRop9 and VvRabA5e cDNAs were introduced separately into S. cerevisiae mutants with RHO1 and YPT31/YPT32 defective genes respectively. Neither cDNAs could complement these temperature-sensitive mutants, suggesting that the functions of the VvRop9 and VvRabA5e genes in grapevine likely differ from the functions of RHO1 and YPT31/YPT32 genes in yeast.
The GCC repeat length in the 5'UTR of MRP1 gene is polymorphic: a functional characterization of its relevance for cystic fibrosis
BACKGROUND: Among the members of the ATP binding cassette transporter superfamily, MRPs share the closest homology with the CFTR protein, which is defective in CF disease. MRP1 has been proposed as a potential modifier gene and/or as novel target for pharmacotherapy of CF to explain the clinical benefits observed in some CF patients treated with the macrolide AZM. The 5'UTR of the MRP1 gene contains a GCC triplet repeat that could represent a polymorphic site and affect the activity of the promoter. METHODS: The MRP1 5' flanking region was amplified by PCR from 36 CF patients and 100 non-CF subjects and the number of GCC triplets of each allele was determined by sequence and electrophoretic analysis. We performed gene reporter studies in CF airway epithelial cells 16HBE14o-AS3, in basal conditions and in the presence of AZM. RESULTS: We found that the GCC repeat is polymorphic, ranging from 7 to 14 triplets either in CF or in non-CF subjects. Our data are preliminary and have to be confirmed on a larger population of CF subjects. The transcriptional activity of the proximal MRP1 5' regulatory region revealed no statistically significant correlations between the number of repeats and treatment with AZM. CONCLUSION: We identified a novel polymorphism in the 5'UTR of MRP1 gene that provides multiple alleles in a gene relevant for multidrug resistance as well as for CF, determining that this region is transcriptionally active and that this activity does not appear to be influenced by AZM treatment
Morphological Plant Modeling: Unleashing Geometric and Topological Potential within the Plant Sciences
The geometries and topologies of leaves, flowers, roots, shoots, and their arrangements have fascinated plant biologists and mathematicians alike. As such, plant morphology is inherently mathematical in that it describes plant form and architecture with geometrical and topological techniques. Gaining an understanding of how to modify plant morphology, through molecular biology and breeding, aided by a mathematical perspective, is critical to improving agriculture, and the monitoring of ecosystems is vital to modeling a future with fewer natural resources. In this white paper, we begin with an overview in quantifying the form of plants and mathematical models of patterning in plants. We then explore the fundamental challenges that remain unanswered concerning plant morphology, from the barriers preventing the prediction of phenotype from genotype to modeling the movement of leaves in air streams. We end with a discussion concerning the education of plant morphology synthesizing biological and mathematical approaches and ways to facilitate research advances through outreach, cross-disciplinary training, and open science. Unleashing the potential of geometric and topological approaches in the plant sciences promises to transform our understanding of both plants and mathematics
A multi-scale model of the interplay between cell signalling and hormone transport in specifying the root meristem of Arabidopsis thaliana
The growth of the root of Arabidopsis thaliana is sustained by the meristem, a region of cell proliferation and differentiation which is located in the root apex and generates cells which move shootwards, expanding rapidly to cause root growth. The balance between cell division and differentiation is maintained via a signalling network, primarily coordinated by the hormones auxin, cytokinin and gibberellin. Since these hormones interact at different levels of spatial organisation, we develop a multi-scale computational model which enables us to study the interplay between these signalling networks and cell cell communication during the specification of the root meristem. We investigate the responses of our model to hormonal perturbations, validating the results of our simulations against experimental data. Our simulations suggest that one or more additional components are needed to explain the observed expression patterns of a regulator of cytokinin signalling, ARR1, in roots not producing gibberellin. By searching for novel network components, we identify two mutant lines that affect significantly both root length and meristem size, one of which also differentially expresses a central component of the interaction network (SHY2). More generally, our study demonstrates how a multi-scale investigation can provide valuable insight into the spatio-temporal dynamics of signalling networks in biological tissues
Azithromycin reduces spontaneous and induced inflammation in ÎF508 cystic fibrosis mice
BACKGROUND: Inflammation plays a critical role in lung disease development and progression in cystic fibrosis. Azithromycin is used for the treatment of cystic fibrosis lung disease, although its mechanisms of action are poorly understood. We tested the hypothesis that azithromycin modulates lung inflammation in cystic fibrosis mice. METHODS: We monitored cellular and molecular inflammatory markers in lungs of cystic fibrosis mutant mice homozygous for the ÎF508 mutation and their littermate controls, either in baseline conditions or after induction of acute inflammation by intratracheal instillation of lipopolysaccharide from Pseudomonas aeruginosa, which would be independent of interactions of bacteria with epithelial cells. The effect of azithromycin pretreatment (10 mg/kg/day) given by oral administration for 4 weeks was evaluated. RESULTS: In naive cystic fibrosis mice, a spontaneous lung inflammation was observed, characterized by macrophage and neutrophil infiltration, and increased intra-luminal content of the pro-inflammatory cytokine macrophage inflammatory protein-2. After induced inflammation, cystic fibrosis mice combined exaggerated cellular infiltration and lower anti-inflammatory interleukin-10 production. In cystic fibrosis mice, azithromycin attenuated cellular infiltration in both baseline and induced inflammatory condition, and inhibited cytokine (tumor necrosis factor-α and macrophage inflammatory protein-2) release in lipopolysaccharide-induced inflammation. CONCLUSION: Our findings further support the concept that inflammatory responses are upregulated in cystic fibrosis. Azithromycin reduces some lung inflammation outcome measures in cystic fibrosis mice. We postulate that some of the benefits of azithromycin treatment in cystic fibrosis patients are due to modulation of lung inflammation
The importance of over-the-counter-sales and product format in the environmental exposure assessment of active pharmaceutical ingredients
Item does not contain fulltex
- âŠ