Search results for "Signal"
showing 10 items of 6924 documents
What Can Proteomics Tell Us About Platelets?
2014
More than 130 years ago, it was recognized that platelets are key mediators of hemostasis. Nowadays, it is established that platelets participate in additional physiological processes and contribute to the genesis and progression of cardiovascular diseases. Recent data indicate that the platelet proteome, defined as the complete set of expressed proteins, comprises >5000 proteins and is highly similar between different healthy individuals. Owing to their anucleate nature, platelets have limited protein synthesis. By implication, in patients experiencing platelet disorders, platelet (dys)function is almost completely attributable to alterations in protein expression and dynamic difference…
Explaining the phenomenon of nitrate tolerance.
2005
During the last century, nitroglycerin has been the most commonly used antiischemic and antianginal agent. Unfortunately, after continuous application, its therapeutic efficacy rapidly vanishes. Neurohormonal activation of vasoconstrictor signals and intravascular volume expansion constitute early counter-regulatory responses (pseudotolerance), whereas long-term treatment induces intrinsic vascular changes, eg, a loss of nitrovasodilator-responsiveness (vascular tolerance). This is caused by increased vascular superoxide production and a supersensitivity to vasoconstrictors secondary to a tonic activation of protein kinase C. NADPH oxidase(s) and uncoupled endothelial nitric oxide synthase …
Guided ultrasonic waves in long bones: modelling, experiment and in vivo application.
2002
Existing ultrasound devices for assessing the human tibia are based on detecting the first arriving signal, corresponding to a wave propagating at, or close to, the bulk longitudinal velocity in bone. However, human long bones are effectively irregular hollow tubes and should theoretically support the propagation of more complex guided modes similar to Lamb waves in plates. Guided waves are attractive because they propagate throughout the bone thickness and can potentially yield more information on bone material properties and architecture. In this study, Lamb wave theory and numerical simulations of wave propagation were used to gain insights into the expected behaviour of guided waves in …
Modification of Plasma Membrane Organization in Tobacco Cells Elicited by Cryptogein
2014
Abstract Lipid mixtures within artificial membranes undergo a separation into liquid-disordered and liquid-ordered phases. However, the existence of this segregation into microscopic liquid-ordered phases has been difficult to prove in living cells, and the precise organization of the plasma membrane into such phases has not been elucidated in plant cells. We developed a multispectral confocal microscopy approach to generate ratiometric images of the plasma membrane surface of Bright Yellow 2 tobacco (Nicotiana tabacum) suspension cells labeled with an environment sensitive fluorescent probe. This allowed the in vivo characterization of the global level of order of this membrane, by which w…
Extracellular membrane vesicles as a mechanism of cell-to-cell communication: advantages and disadvantages.
2014
Microvesicles represent a newly identified mechanism of intercellular communication. Two different types of microvesicles have been identified: membrane-derived vesicles (EVs) and exosomes. EVs originate by direct budding from the plasma membrane, while exosomes arise from ectocytosis of multivesicular bodies. Recent attention has focused on the capacity of EVs to alter the phenotype of neighboring cells to make them resemble EV-producing cells. Stem cells are an abundant source of EVs, and the interaction between stem cells and the microenvironment (i.e., stem cell niche) plays a critical role in determining stem cell phenotype. The stem cell niche hypothesis predicts that stem cell number…
Quercetin and MicroRNA Interplay in Apoptosis Regulation in Ovarian Cancer
2020
The multifaceted nature of ovarian cancer has severely hampered the development of effective therapeutics over the years. The complicate nature of ovarian cancer makes it therapeutically challenging, therefore, there has been a renewed interest in phytochemistry. Phytochemicals have emerged as a potential therapeutic option due to less side effects. Moreover, the signaling inhibition properties have also been studied extensively in recent times. A growing number of data obtained via high-throughput technologies has started to delineate the complex oncogenic signaling networks, thus broadening the therapeutic opportunities. Within the network, microRNAs (miRNAs) have been shown to play a ve…
Localized versus systemic effect of arbuscular mycorrhizal fungi on defence responses to Phytophthora infection in tomato plants
2002
Development of biological control for plant diseases is accepted as a durable and environmentally friendly alternative for agrochemicals. Arbuscular mycorrhizal fungi (AMF), which form symbiotic associations with root systems of most agricultural, horticultural and hardwood crop species, have been suggested as widespread potential bioprotective agents. In the present study the ability of two AMF (Glomus mosseae and Glomus intraradices) to induce local or systemic resistance to Phytophthora parasitica in tomato roots have been compared using a split root experimental system. Glomus mosseae was effective in reducing disease symptoms produced by P. parasitica infection, and evidence points to …
Are elicitins cryptograms in plant-oomycete communications?
1999
Stimulation of plant natural defenses is an important challenge in phytoprotection prospects. In that context, elicitins, which are small proteins secreted by Phytophthora and Pythium species, have been shown to induce a hypersensitive-like reaction in tobacco plants. Moreover, these plants become resistant to their pathogens, and thus this interaction constitutes an excellent model to investigate the signaling pathways leading to plant resistance. However, most plants are not reactive to elicitins, although they possess the functional signaling pathways involved in tobacco responses to elicitin. The understanding of factors involved in this reactivity is needed to develop agronomic applica…
Development of a low-cost piezo film-based knock sensor
2003
It is well known that spark advance is a key parameter in spark ignition engine management. Increasing fuel cost and emission regulation strictness require a higher engine efficiency, which can be improved by an accurate regulation of the spark advance. Under high load conditions, an optimal spark advance choice leads the engine to run next to the knock limit, so the management and control system needs to be equipped with a knock sensor in order to preserve the engine from damage. The authors developed a low-cost knock sensor whose sensing element is a thin washer of polyvinylidine fluoride (PVDF), a fluoropolymer characterized by a great piezoelectric e ect if polarized. The sensor has be…
Reduced Temperature Sensitivity of Maximum Latewood Density Formation in High-Elevation Corsican Pines under Recent Warming
2021
Maximum latewood density (MXD) measurements from long-lived Black pines (Pinus nigra spp. laricio) growing at the upper treeline in Corsica are one of the few archives to reconstruct southern European summer temperatures at annual resolution back into medieval times. Here, we present a compilation of five MXD chronologies from Corsican pines that contain high-to-low frequency variability between 1168 and 2016 CE and correlate significantly (p <