Search results for "cellular"
showing 10 items of 6449 documents
Understanding the Role of Sensorimotor Beta Oscillations
2021
Beta oscillations have been predominantly observed in sensorimotor cortices and basal\ud ganglia structures and they are thought to be involved in somatosensory processing\ud and motor control. Although beta activity is a distinct feature of healthy and pathological\ud sensorimotor processing, the role of this rhythm is still under debate. Here we review\ud recent findings about the role of beta oscillations during experimental manipulations (i.e.,\ud drugs and brain stimulation) and their alteration in aging and pathology. We show how\ud beta changes when learning new motor skills and its potential to integrate sensory input\ud with prior contextual knowledge. We conclude by discussing a n…
An impaired alveolar-capillary barrier in vitro : effect of proinflammatory cytokines and consequences on nanocarrier interaction.
2009
The alveolar region of the lung is an important target for drug and gene delivery approaches. Treatment with drugs is often necessary under pathophysiological conditions, in which there is acute inflammation of the target organ. Therefore, in vitro models of the alveolar-capillary barrier, which mimic inflammatory conditions in the alveolar region, would be useful to analyse and predict effects of novel drugs on healthy or inflamed tissues. The epithelial cell line H441 was cultivated with primary isolated human pulmonary microvascular endothelial cells (HPMECs) or the endothelial cell line ISO-HAS-1 on opposite sides of a permeable filter support under physiological and inflammatory condi…
Changes in the Phytochemical Profile and Antioxidant Properties of Prunus persica Fruits after the Application of a Commercial Biostimulant Based on …
2022
Plant biostimulants are formulations that are experiencing great success from the perspective of sustainable agriculture. In this work, we evaluated the effect derived from the application of a biostimulant based on algae and yeast extracts (Expando®) on the agronomic yield and nutraceutical profile of two different cultivars (“Sugar Time” and “West Rose”) of Prunus persica (peach). Although, at the agronomic level, significant effects on production yields were not recorded, the biostimulant was able to reduce the ripening time, increase the fruit size, and make the number of harvestable fruits homogeneous. From a nutraceutical point of view, our determinations v…
Processing of metals and metalloids by actinobacteria: Cell resistance mechanisms and synthesis of metal(loid)-based nanostructures
2020
Metal(loid)s have a dual biological role as micronutrients and stress agents. A few geochemical and natural processes can cause their release in the environment, although most metal-contaminated sites derive from anthropogenic activities. Actinobacteria include high GC bacteria that inhabit a wide range of terrestrial and aquatic ecological niches, where they play essential roles in recycling or transforming organic and inorganic substances. The metal(loid) tolerance and/or resistance of several members of this phylum rely on mechanisms such as biosorption and extracellular sequestration by siderophores and extracellular polymeric substances (EPS), bioaccumulation, biotransformation, and me…
Changes in the Pi uptake and polyP accumulation in Saccharomyces cerevisiae strains deficient in the synthesis of trehalose and/or glycerol
2007
Abstract The intracellular level of free inorganic orthophosphate (P i ) in yeast cells generally depends on the P i uptake capacity, energy state of the cells in respect to the activity of the membrane-associated ATPases and on the activity of metabolic pathways involved in the production of glycerol and trehalose. Batch fermentation was performed to investigate the carbon substrate consumption, the P i uptake capacity and product formation by four Saccharomyces cerevisiae strains differing in their ability to produce glycerol and/or trehalose. The consumption of P i in mutant strains with a lack of the synthesis of the trehalose and/or glycerol exceeded the level for a wild type strain ab…
pH Homeostasis and Citric Acid Utilization: Differences Between Leuconostoc mesenteroides and Lactococcus lactis
1997
This study presents the effects of citric acid and extracellular pH (pHe) on the intracellular pH (pHi) of wild-type and citrate negative variants (cit−) Leuconostoc mesenteroides subsp. mesenteroides (Ln. mesenteroides M) and Lactococcus lactis subsp. lactis bv. diacetylactis (L. lactis LD). A recent method using a pH-sensitive fluorescent indicator carboxyfluorescein succinimidyl ester (cFSE) was adapted to measure the pHi of these two lactic acid bacteria in resting cells. Energized cells with 10 mM lactose of Ln. mesenteroides M and L. lactis LD modified their pH gradient (ΔpH) in the same manner; when the pHe was decreased from 7 to 4, the pHi decreased from 7 to about 5. The adjunctio…
Evolution of Cell Adhesion Systems: Evidence for Arg-Gly-Asp-Mediated Adhesion in the Protozoan Neoparamoeba aestuarina
1995
Developmental processes in multicellular organisms require structural elements, such as adhesion molecules, to stabilize cells at functional positions. In vertebrates, a series of extracellular matrix proteins, e.g. fibronectin and laminin, are involved in cell adhesion. These proteins contain Arg-Gly-Asp [RGD] at their binding sites. Here we show that at concentrations above 2 mM the peptide GRGDSPK, comprising the tripeptide RGD (Arg-Gly-Asp), prevents the adhesiveness of cells of the marine amoeba Neoparamoeba aestuarina. In addition, elevated levels of GRGDSPK cause cells to alter their shapes from those with digitiform subpseudopodia to rounded cells with small lobed pseudopodia. These…
Cajal–Retzius and Subplate Cells
2013
The laminar and columnar organization of the mature cerebral cortex is determined by a variety of early developmental processes. Two distinct populations of early generated preplate neurons play key roles in corticogenesis. Cajal–Retzius neurons, located in the marginal zone (later layer I), control the formation of neocortical layers by releasing the extracellular matrix protein reelin, which serves as a guiding signal for migrating neurons. Subplate neurons in the lower neocortical layer play an active role in transient synaptic circuits and influence early cortical plasticity and the maturation of the columnar architecture. Both neuronal cell populations serve as transient synaptic targe…
Activity of Drug Efflux Transporters in Tumor Cells Under Hypoxic Conditions
2008
Tumor cells exhibit mechanisms by which chemotherapeutic drugs can be actively pumped out of the cell (e.g., p-glycoprotein pGP, MRP1), resulting in a multidrug resistant phenotype. Many human tumors show pronounced hypoxia which can result in a local ATP depletion which in turn may compromise the efficacy of these transporters. The aim of this study was therefore to assess the transport activity and expression of drug transporters under hypoxic conditions. Prostate carcinoma cells (R3327-AT1) were exposed to hypoxia (pO2≶0.5 mmHg) for up to 24h and pump activity was determined by an efflux assay. The results showed that exposing cells to hypoxia for 3–6 h led to a moderate increase in pGP …
Role of GATA-1 and HSP70 in the Dyserythropoiesis of Early Myelodysplastic Syndromes.
2009
Abstract Abstract 3823 Poster Board III-759 Myelodysplastic syndromes (MDS) are heterogeneous hematopoietic stem cell disorders characterized by a hypercellular dysplastic bone marrow (BM) with peripheral blood cytopenias, mainly anemia. Early MDS with less than 10% BM blasts which belong in most cases to low and intermediate-1 (int-1) risk groups according to the International Prognostic Scoring System (IPSS), usually demonstrate dyserythropoiesis. The growth of erythroid progenitors is altered, with increased caspase activation leading to excessive cell death, and cellular dysplasia characterized, in liquid culture of CD34+-derived erythroid progenitors, by a delayed expression of the gly…