288 research outputs found
Structure Related to Morphine
Synthesis of 2-N-heptyl-5,9-dimethyl-6,7-benzomorphan from 3,4-lutidine was effected in three step process and only a-form could be obtained through phosphoric acid cyclisation. This a-form of benzomorphan was converted in three steps to a-2N-hepthyl-2-hydroxy-5,9-dimethyl-6,7-benzomorphan, which was also synthesised from alternative route. Infrared spectrum of the base confirmed the presence of a-from
The proangiogenic capacity of polymorphonuclear neutrophils delineated by microarray technique and by measurement of neovascularization in wounded skin of CD18-deficient mice
Growing evidence supports the concept that polymorphonuclear neutrophils (PMN) are critically involved in inflammation-mediated angiogenesis which is important for wound healing and repair. We employed an oligonucleotide microarray technique to gain further insight into the molecular mechanisms underlying the proangiogenic potential of human PMN. In addition to 18 known angiogenesis-relevant genes, we detected the expression of 10 novel genes, namely midkine, erb-B2, ets-1, transforming growth factor receptor-beta(2) and -beta(3), thrombospondin, tissue inhibitor of metalloproteinase 2, ephrin A2, ephrin B2 and restin in human PMN freshly isolated from the circulation. Gene expression was confi rmed by the RT-PCR technique. In vivo evidence for the role of PMN in neovascularization was provided by studying neovascularization in a skin model of wound healing using CD18-deficient mice which lack PMN infi ltration to sites of lesion. In CD18-deficient animals, neo- vascularization was found to be signifi cantly compromised when compared with wild- type control animals which showed profound neovascularization within the granulation tissue during the wound healing process. Thus, PMN infiltration seems to facilitate inflammation mediated angiogenesis which may be a consequence of the broad spectrum of proangiogenic factors expressed by these cells. Copyright (c) 2006 S. Karger AG, Basel
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Teaching to Fish or Learning Not to Finish? - Reinventing a Responsible Marine Fisheries Extension System in India
The marine fisheries sector in India is currently going through a phase of socio-economic cum ecological turbulence.
The rate of growth in marine fisheries production, as evidenced by recent studies, is plateauing, if not, declining.
The need for initiating management options that promote sustainable resource utilization and stable livelihood
security to the coastal community through well-planned and massive efforts in making the fisher folk imbibe the
message of the FAO Code of Conduct for Responsible Fisheries (FAO CCRF) through Extension initiatives is never
felt so urgent as of now. Extension science is construed as the discipline that raises strategic questions and finds
ways in bridging the research system and the client system. But unlike the farming sector, the extension system in
the case of marine fisheries sector is confronted with a number of epistemological and methodological problems.
Based on the experiences and insights gathered during the implementation of a WB funded research project titled
“Designing and Validation of Communication strategies for responsible fisheries – A Co-learning approach” at
Central Marine Fisheries Research Institute(CMFRI) during 2001-04, this paper argues that the Transfer of
Technology -based extension paradigm dominant in the country is insufficient to infuse an ethos of responsible
fisheries among the stakeholders and therefore it is necessary to reinvent a new extension system, probably built on
the logic of constructivism rather than positivism. The potential of the rich research database on the resource base,
along with Fisheries Indigenous Knowledge system needs to be effectively utilized. A Responsible Fisheries
Extension Module (RFEM), first of its kind in the country, consisting of a number of well-validated communication
tools which includes the translation of the FAO CCRF into Malayalam, animation films etc., developed under the
project through participatory co-learning methodology is a stepping stone in this direction. A theoretical model of a
new extension approach is also proposed after diagnosing various parameters in the current extension system like
information flow, strategic gaps in the research-extension interface vis a vis an ideal system and constraints (logical,
epistemological and institutional)
Identification of candidate tumour suppressor genes frequently methylated in renal cell carcinoma
Promoter region hyermethylation and transcriptional silencing is a frequent cause of tumour suppressor gene (TSG) inactivation in many types of human cancers. Functional epigenetic studies, in which gene expression is induced by treatment with demethylating agents, may identify novel genes with tumour-specific methylation. We used high-density gene expression microarrays in a functional epigenetic study of 11 renal cell carcinoma (RCC) cell lines. Twenty-eight genes were then selected for analysis of promoter methylation status in cell lines and primary RCC. Eight genes (BNC1, PDLIM4, RPRM, CST6, SFRP1, GREM1, COL14A1 and COL15A1) showed frequent (30% of RCC tested) tumour-specific promoter region methylation. Hypermethylation was associated with transcriptional silencing. Re-expression of BNC1, CST6, RPRM and SFRP1 suppressed the growth of RCC cell lines and RNA interference knock-down of BNC1, SFRP1 and COL14A1 increased the growth of RCC cell lines. Methylation of BNC1 or COL14A1 was associated with a poorer prognosis independent of tumour size, stage or grade. The identification of these epigenetically inactivated candidate RCC TSGs can provide insights into renal tumourigenesis and a basis for developing novel therapies and biomarkers for prognosis and detection. © 2010 Macmillan Publishers Limited.Published versio
Targeting vascular endothelial growth factor receptor 2 and protein kinase d1 related pathways by a multiple kinase inhibitor in angiogenesis and inflammation related processes in vitro.
Emerging evidence suggests that the vascular endothelial growth factor receptor 2 (VEGFR2) and protein kinase D1 (PKD1) signaling axis plays a critical role in normal and pathological angiogenesis and inflammation related processes. Despite all efforts, the currently available therapeutic interventions are limited. Prior studies have also proved that a multiple target inhibitor can be more efficient compared to a single target one. Therefore, development of novel inflammatory pathway-specific inhibitors would be of great value. To test this possibility, we screened our molecular library using recombinant kinase assays and identified the previously described compound VCC251801 with strong inhibitory effect on both VEGFR2 and PKD1. We further analyzed the effect of VCC251801 in the endothelium-derived EA.hy926 cell line and in different inflammatory cell types. In EA.hy926 cells, VCC251801 potently inhibited the intracellular activation and signaling of VEGFR2 and PKD1 which inhibition eventually resulted in diminished cell proliferation. In this model, our compound was also an efficient inhibitor of in vitro angiogenesis by interfering with endothelial cell migration and tube formation processes. Our results from functional assays in inflammatory cellular models such as neutrophils and mast cells suggested an anti-inflammatory effect of VCC251801. The neutrophil study showed that VCC251801 specifically blocked the immobilized immune-complex and the adhesion dependent TNF-alpha -fibrinogen stimulated neutrophil activation. Furthermore, similar results were found in mast cell degranulation assay where VCC251801 caused significant reduction of mast cell response. In summary, we described a novel function of a multiple kinase inhibitor which strongly inhibits the VEGFR2-PKD1 signaling and might be a novel inhibitor of pathological inflammatory pathways
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Computational Modeling of Twin Screw Pumps for Thermal Management Applications
Electrification has become less of a catchphrase and increasingly commonplace when discussing today’s locomotives. Engineers developing thermal management strategies (both component suppliers and system-level analysts) must be armed with effective tools to design and analyze essential components such as coolant pumps and study their behavior in an actual system. This study focuses on the analysis of twin screw pumps for cooling battery packs in hybrid and battery electric vehicles via three different approaches – experimental measurements, a one-dimensional (1D) thermodynamic chamber model, and a three-dimensional (3D) computational fluid dynamics (CFD) model. Experimental measurements are conducted to quantify the coolant’s volume flow rate and the shaft power consumption over a range of operating speeds and pump discharge pressures. While these measurements provide some insight into the overall internal leakages and pumping efficiencies, more comprehensive tests at a higher cost are required to fully understand the detailed thermodynamic processes occurring within the pump. Two computational modeling approaches are presented and extensively validated against these measurements. The 1D chamber model demonstrates a good agreement of all measured quantities at a very low computational cost. It also provides useful information regarding the relative importance of the various leakage paths along with the working processes and pressure pulsations. This makes it an effective tool to quickly analyze operating conditions where test data may not be available and iterate towards improved designs via parametric analysis. 3D CFD yields very good agreement compared to the measured results and provides a more complete picture with greater spatial accuracy that is sacrificed in the 1D approach. However, this is available at a significantly higher computational cost. A combination of both methodologies can guide engineers in designing screw pumps for optimal performance
Cilia Proteins are Biomarkers of Altered Flow in the Vasculature
Cilia, microtubule-based organelles that project from the apical luminal surface of endothelial cells (ECs), are widely regarded as low-flow sensors. Previous reports suggest that upon high shear stress, cilia on the EC surface are lost, and more recent evidence suggests that deciliation—the physical removal of cilia from the cell surface—is a predominant mechanism for cilia loss in mammalian cells. Thus, we hypothesized that EC deciliation facilitated by changes in shear stress would manifest in increased abundance of cilia-related proteins in circulation. To test this hypothesis, we performed shear stress experiments that mimicked flow conditions from low to high shear stress in human primary cells and a zebrafish model system. In the primary cells, we showed that upon shear stress induction, indeed, ciliary fragments were observed in the effluent in vitro, and effluents contained ciliary proteins normally expressed in both endothelial and epithelial cells. In zebrafish, upon shear stress induction, fewer cilia-expressing ECs were observed. To test the translational relevance of these findings, we investigated our hypothesis using patient blood samples from sickle cell disease and found that plasma levels of ciliary proteins were elevated compared with healthy controls. Further, sickled red blood cells demonstrated high levels of ciliary protein (ARL13b) on their surface after adhesion to brain ECs. Brain ECs postinteraction with sickle RBCs showed high reactive oxygen species (ROS) levels. Attenuating ROS levels in brain ECs decreased cilia protein levels on RBCs and rescued ciliary protein levels in brain ECs. Collectively, these data suggest that cilia and ciliary proteins in circulation are detectable under various altered-flow conditions, which could serve as a surrogate biomarker of the damaged endothelium
Finding one's way in proteomics: a protein species nomenclature
Our knowledge of proteins has greatly improved in recent years, driven by new technologies in the fields of molecular biology and proteome research. It has become clear that from a single gene not only one single gene product but many different ones - termed protein species - are generated, all of which may be associated with different functions. Nonetheless, an unambiguous nomenclature for describing individual protein species is still lacking. With the present paper we therefore propose a systematic nomenclature for the comprehensive description of protein species. The protein species nomenclature is flexible and adaptable to every level of knowledge and of experimental data in accordance with the exact chemical composition of individual protein species. As a minimum description the entry name (gene name + species according to the UniProt knowledgebase) can be used, if no analytical data about the target protein species are available
Structural and kinetic characterization of DUSP5 with a Di-phosphorylated tripeptide substrate from the ERK activation loop
Introduction: Dual specific phosphatases (DUSPs) are mitogen-activated protein kinase (MAPK) regulators, which also serve as drug targets for treating various vascular diseases. Previously, we have presented mechanistic characterizations of DUSP5 and its interaction with pERK, proposing a dual active site.Methods: Herein, we characterize the interactions between the DUSP5 phosphatase domain and the pT-E-pY activation loop of ERK2, with specific active site assignments. We also report the full NMR chemical shift assignments of DUSP5 that now enable chemical shift perturbation and dynamics studies.Results and Discussion: Both phosphates of the pT-E-pY tripeptide are dephosphorylated, based on 31P NMR; but, steady state kinetic studies of the tripeptide both as a substrate and as an inhibitor indicate a preference for binding and dephosphorylation of the phospho-tyrosine before the phospho-threonine. Catalytic efficiency (kcat/Km) is 3.7 M−1S−1 for T-E-pY vs 1.3 M−1S−1 for pT-E-Y, although the diphosphorylated peptide (pT-E-pY) is a better substrate than both, with kcat/Km = 18.2 M−1S−1 . Steady state inhibition studies with the pNPP substrate yields Kis values for the peptide inhibitors of: 15.82 mM (pT-E-Y), 4.932 mM (T-E-pY), 1.672 mM (pT-E-pY). Steady state inhibition studies with pNPP substrate and with vanadate or phosphate inhibitors indicated competitive inhibition with Kis values of 0.0006122 mM (sodium vanadate) and 17.32 mM (sodium phosphate), similar to other Protein Tyrosine Phosphatases with an active site cysteine nucleophile that go through a five-coordinate high energy transition state or intermediate. Molecular dynamics (MD) studies confirm preferential binding of the diphosphorylated peptide, but with preference for binding the pY over the pT reside in the catalytic site proximal to the Cys263 nucleophile. Based on MD, the monophosphorylated peptide binds tighter if phosphorylated on the Tyr vs the Thr. And, if the starting pose of the docked diphosphorylated peptide has pT in the catalytic site, it will adjust to have the pY in the catalytic site, suggesting a dynamic shifting of the peptide orientation. 2D 1H-15N HSQC chemical shift perturbation studies confirm that DUSP5 with tripeptide bound is in a dynamic state, with extensive exchange broadening observed—especially of catalytic site residues. The availability of NMR chemical shift assignments enables additional future studies of DUSP5 binding to the ERK2 diphosphorylated activation loop.Summary: These studies indicate a preference for pY before pT binding, but with ability to bind and dephosphorylate both residues, and with a dynamic active site pocket that accommodates multiple tripeptide orientations
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