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Obvious Impact (obvious + impact)

Distribution by Scientific Domains

Medical Sciences	40%
Life Sciences	40%

Selected Abstracts

Melatonin modulates the expression of VEGF and HIF-1, induced by CoCl2 in cultured cancer cells

JOURNAL OF PINEAL RESEARCH, Issue 2 2008
Min Dai
Abstract:, Melatonin is an important natural oncostatic agent. At present there are no data available as to its possible influence on tumor angiogenesis, which is a major biological mechanism responsible for tumor growth and dissemination. It is well known that vascular endothelial growth factor (VEGF) is crucial to a solid tumor's higher vascularization and development. To investigate the possible influence of melatonin on angiogenesis, we studied the effect of melatonin on endogenous VEGF expression in three human cancer cell lines (PANC-1, HeLa and A549 cells). In this study, we report that physiologic concentrations of melatonin have no obvious impact on the VEGF expression, whereas pharmacologic concentrations of melatonin suppress the VEGF mRNA and protein levels induced by hypoxia mimetic cobalt chloride (CoCl2). Melatonin also decreases hypoxia-inducible factor (HIF)-1, protein levels, suggesting a role for transcription factor HIF-1 in the suppression of VEGF expression. The effect of pharmacologic concentrations of melatonin on VEGF and HIF-1, under normoxia is uncertain, which indicates that the regulatory mechanisms of VEGF in the absence or presence of CoCl2 are different and other or additional transcription factors may be involved. Taken together, our data show that melatonin in high concentrations markedly reduces the expression of endogenous VEGF and HIF-1, induced by CoCl2 in cultured cancer cells. [source]

The Impact of Electronic Reverse Auctions on Supplier Performance: The Mediating Role of Relationship Variables

JOURNAL OF SUPPLY CHAIN MANAGEMENT, Issue 1 2007
Craig R. Carter
The use of electronic reverse auctions (ERAs) by buying organizations has increased dramatically over the past five years. Both anecdotal and empirical evidence have shown that ERAs can lower purchase prices. However, researchers are only just beginning to investigate how ERAs impact perceptions of opportunism as compared to sealed bids and traditional negotiations. Further, researchers have yet to examine how perceptions of opportunism surrounding ERAs might in turn affect such outcome variables as trust, commitment, conflict, and ultimately nonprice attributes of supplier performance. The authors address this gap in the research by developing a theoretically grounded model of the interrelationships among these five variables, and empirically testing the model through a survey of buying organizations that rely heavily on ERAs to select and source from suppliers. The authors' findings suggest that increased levels of opportunism harm supplier nonprice performance, through both their more obvious impact on dysfunctional conflict and their more latent effects on relationship trust and commitment. [source]

Neuromuscular Electrical Stimulation As a Possible Means to Prevent Muscle Tissue Wasting in Artificially Ventilated and Sedated Patients in the Intensive Care Unit: A Pilot Study

NEUROMODULATION, Issue 4 2010
Raf L.J. Meesen PhD
Objective:, The aim of this study was to explore if electrical stimulation could prevent muscle atrophy. Material and Methods:, Patients were hospitalized for postoperative coronary artery bypass graftin, chronic obstructive pulmonary disease, ventilatory failure, or acute cerebro-vascular accident, and were divided into an intervention group or a control group. The intervention group underwent daily 30 minute training with an intermittent neuromuscular electrical stimulation applied to the right quadriceps muscle. Heart rate, respiration rate, systolic and diastolic blood pressure, and oxygen saturation were monitored before, during, and after electrical stimulation. Circumference of both thighs was measured. Results:, The intervention resulted in a significant reduction of muscle atrophy in the stimulated as compared with the non-stimulated limb (p < 0.05), without making any impact on cardiovascular, respiratory and, hemodynamic characteristics. Conclusions:, Muscle atrophy is prevented by intermittent neuromuscular electrical stimulation while this intervention showed no obvious impact on the cardio-respiratory conditions of the patients. [source]

Evidence for cis -acting regulation of ANK3 and CACNA1C gene expression

BIPOLAR DISORDERS, Issue 4 2010
Emma M Quinn
Quinn EM, Hill M, Anney R, Gill M, Corvin AP, Morris DW. Evidence for cis -acting regulation of ANK3 and CACNA1C gene expression. Bipolar Disord 2010: 12: 440,445. © 2010 The Authors. Journal compilation © 2010 John Wiley & Sons A/S. Objectives:, Genome-wide association studies (GWAS) have identified Ankyrin-G (ANK3) and the ,-1C subunit of the L-type voltage-gated calcium channel (CACNA1C) as susceptibility genes for bipolar disorder. Available biological information on these genes suggests a potential molecular mechanism involving ion channel dysfunction. The associated single nucleotide polymorphisms (SNPs) at ANK3 (rs10994336) and CACNA1C (rs1006737) are both intronic with no obvious impact on gene function. We investigated whether, instead of affecting protein function, these risk variants might impact on gene regulation affecting expression. Methods:, We have done this by testing for allelic expression imbalance (AEI) to identify cis -acting regulatory polymorphisms. Results:, We identified evidence of cis -acting variation at both loci in HapMap Caucasian Europeans from Utah (CEU) lymphoblastoid cell lines. There was considerable evidence of AEI at ANK3 with more than half of all heterozygous samples (21 out of 34) for marker SNP rs3750800 showing AEI and a small number of samples showing near monoallelic expression. The AEI at either gene could not be attributed to the GWAS-associated SNPs. Conclusions:, These data indicate that there is genetic variation local to both genes affecting their expression, but that this variation is not responsible for increasing risk of bipolar disorder. [source]

Pathogenicity of seed-associated fungi to Podocarpus falcatus in vitro

FOREST PATHOLOGY, Issue 1 2005
A. Gure
Summary Twenty-nine fungi that were isolated from seeds and female cones of Podocarpus falcatus from natural forests in Ethiopia, were assessed for their impact on seeds and seedlings of the same host. Based on the results from in vitro seed inoculation tests, we could group the fungi into five categories as: (i) isolates that were pathogenic only to seeds and had no obvious impacts on the germlings; (ii) isolates that were pathogenic only to the germlings; (iii) isolates that were pathogenic both to seeds and the emerging germlings; (iv) isolates that were more or less harmless; and (v) isolates that were germination promoters. Inoculation tests were also performed on 4,7-day-old aseptically grown seedlings. Fusarium oxysporum and Polyporus sp., were strongly pathogenic to both seeds and seedlings, while Nectria gliocladioides, Peniophora cinerea and Pestalotiopsis neglecta also demonstrated pathogenicity but to a lesser extent. Other isolates, e.g. Diaporthe spp. resulted in increased germination of P. falcatus seeds and no pathogenicity to seedlings. However, further investigations are required in order to find out how these fungi behave under nursery or field conditions. Résumé L'étude porte sur l'impact sur les graines et semis de Podocarpus falcatus de vingt-neuf champignons isolés de graines et fruits du même hôte en forêts naturelles en Ethiopie. D'après les résultats des inoculations de semences in vitro, les champignons peuvent être classés en 5 groupes: (i) les isolats pathogènes uniquement sur graines et sans effet apparent sur plantules; (ii) les isolats pathogènes uniquement sur plantules; (iii) les isolats pathogènes à la fois sur graines et sur plantules émergentes; (iv) les isolats non pathogènes; (v) les isolats favorisant la germination. Des inoculations ont également été pratiquées sur des semis de 4,7 jours produits en conditions axéniques. Fusarium oxysporum et Polyporus sp. montrent un fort pouvoir pathogène à la fois sure graines et semis, Nectria gliocladioides, Peniophora cinerea et Pestalotiopsis neglecta sont également pathogènes mais à un moindre degré. D'autres isolats, comme Diaporthe spp., induisent une augmentation de germination des graines de P. falcatus et ne sont pas pathogènes sur plantules. Des études complémentaires sont nécessaires pour déterminer le comportement de ces champignons en pépinières ou en conditions naturelles. Zusammenfassung Von Samen und weiblichen Zapfen von Podocarpus falcatus aus Naturwäldern in Äthiopien wurden 29 Pilze isoliert und auf ihre Pathogenität an Samen und Sämlinge der gleichen Art getestet. Anhand der Inokulationstests an Samen in vitro wurden die Pilze in 5 Klassen eingeteilt: (i) Pilze, die nur den Samen schädigen und keine Auswirkung auf den Keimling haben; (ii) Pilze, die nur den Keimling schädigen; (iii) Pilze, die sowohl den Samen als auch den Keimling schädigen; (iv) nicht pathogene Pilze; und (v) Pilze, welche die Keimung fördern. Zusätzlich wurden Inokulationstests an vier bis sieben Tage alten steril gekeimten Sämlingen durchgeführt. Fusarium oxysporum und Polyporus sp. waren sowohl an Samen als auch an Keimlingen stark pathogen, Nectria gliocladioides, Peniophora cinerea und Pestalotiopsis neglecta waren weniger stark pathogen. Andere Isolate, wie z.B. Diaporthe spp. waren apathogen und förderten die Keimung. Zur Abklärung des Verhaltens dieser Pilze unter Freilandbedingungen sind jedoch weitere Untersuchungen notwendig. [source]