Search results for "transport systems"

Le aree a domanda debole di trasporto: un metodo per la loro individuazione

2010

Could Technology and Intelligent Transport Systems Help Improve Mobility in an Emerging Country? Challenges, Opportunities, Gaps and Other Evidence f…

2022

Apart from constituting a topic of high relevance for transport planners and policymakers, support technologies for traffic have the potential to bring significant benefits to mobility. In addition, there are groups of “high potential” users, such as young adults, who constitute an essential part of the current market. Notwithstanding, and especially in low and middle-income countries (LMICs), their knowledge and acceptance remain understudied. This study aimed to assess the appraisal of intelligent transport systems (ITS) and other technological developments applicable to mobility among Dominican young adults. Methods: In this study, we used the data gathered from 1414 Dominicans aged betw…

Identification of Cysteine Residues in Human Cationic Amino Acid Transporter hCAT-2A That Are Targets for Inhibition by N-Ethylmaleimide

2013

In most cells, cationic amino acids such as l-arginine, l-lysine, and l-ornithine are transported by cationic (CAT) and y(+)L (y(+)LAT) amino acid transporters. In human erythrocytes, the cysteine-modifying agent N-ethylmaleimide (NEM) has been shown to inhibit system y(+) (most likely CAT-1), but not system y(+)L (Devés, R., Angelo, S., and Chávez, P. (1993) J. Physiol. 468, 753-766). We thus wondered if sensitivity to NEM distinguishes generally all CAT and y(+)LAT isoforms. Transport assays in Xenopus laevis oocytes established that indeed all human CATs (including the low affinity hCAT-2A), but neither y(+)LAT isoform, are inhibited by NEM. hCAT-2A inhibition was not due to reduced tran…

Human cationic amino acid transporter gene hCAT-2 is assigned to 8p22 but is not the causative gene in lysinuric protein intolerance

1997

Lysinuric protein intolerance (LPI) is a recessively inherited amino acid disorder characterized by defective efflux of cationic amino acids at the basolateral membrane of the intestinal and renal tubular epithelium. Recently, cDNAs encoding the related proteins hCAT-2A and hCAT-2B have been cloned. These two carrier proteins are most likely the product of the same gene, hCAT-2. Using the hCAT-2B cDNA, we assigned the hCAT-2 gene to chromosome 8p22. Furthermore, by linkage analysis in Finnish LPI families, we ruled out that hCAT-2B is involved in LPI disease.

Putative role of cationic amino acid transporter‐3 in murine liver metabolism

2015

Role of Neutral Amino Acid Transport and Protein Breakdown for Substrate Supply of Nitric Oxide Synthase in Human Endothelial Cells

2003

Endothelial dysfunction is often associated with a relative substrate deficiency of the endothelial nitric oxide synthase (eNOS) in spite of apparently high intracellular arginine concentrations. For a better understanding of the underlying pathophysiological mechanisms, we aimed to characterize the intracellular arginine sources of eNOS. Our previous studies in human endothelial EA.hy926 cells suggested the existence of two arginine pools: pool I can be depleted by extracellular lysine, whereas pool II is not freely exchangeable with the extracellular space, but accessible to eNOS. In this study, we demonstrate that the eNOS accessible pool II is also present in human umbilical vein endoth…

WPŁYW PANDEMII COVID-19 NA FUNKCJONOWANIE REGIONALNEGO TRANSPORTU KOLEJOWEGO OBSZARÓW PRZYGRANICZNYCH – NA PRZYKŁADZIE WOJEWÓDZTWA DOLNOŚLĄSKIEGO (PL…

2021

Systemy zbiorowego transportu publicznego są narażone na wiele zewnętrznych czynników wpływających na ich funkcjonowanie. Jednym z nich może być zagrożenie epidemiologiczne. W 2020 r. światowa pandemia COVID-19 miała istotny wpływ na światową gospodarkę oraz przewozy pasażerskie. Wprowadzone liczne ograniczenia wpłynęły na popyt (liczbę pasażerów) oraz podaż (oferta przewozowa) na rynku transportu. Do najczęstszych obostrzeń zaliczyć można: ograniczenie liczby połączeń, zmniejszenie limitu pasażerów w pojeździe, ograniczenie siatki połączeń komunikacyjnych. W analizie autorzy przeprowadzili badanie województwa dolnośląskiego oraz kraju libereckiego w kontekście zmian w funkcjonowaniu region…

A chimera carrying the functional domain of the orphan protein SLC7A14 in the backbone of SLC7A2 mediates trans-stimulated arginine transport.

2012

In human skin fibroblasts, a lysosomal transport system specific for cationic amino acids has been described and named system c. We asked if SLC7A14 (solute carrier family 7 member A14), an orphan protein assigned to the SLC7 subfamily of cationic amino acid transporters (CATs) due to sequence homology, may represent system c. Fusion proteins between SLC7A14 and enhanced GFP localized to intracellular vesicles, co-staining with the lysosomal marker LysoTracker(®). To perform transport studies, we first tried to redirect SLC7A14 to the plasma membrane (by mutating putative lysosomal targeting motifs) but without success. We then created a chimera carrying the backbone of human (h) CAT-2 and …

The stimulation of arginine transport by TNFα in human endothelial cells depends on NF-κB activation

2004

In human saphenous vein endothelial cells (HSVECs), tumor necrosis factor-alpha (TNFalpha) and bacterial lipopolysaccharide (LPS), but neither interferon gamma (IFNgamma) nor interleukin 1beta (IL-1beta), stimulate arginine transport. The effects of TNFalpha and LPS are due solely to the enhancement of system y+ activity, whereas system y+L is substantially unaffected. TNFalpha causes an increased expression of SLC7A2/CAT-2B gene while SLC7A1/CAT-1 expression is not altered by the cytokine. The suppression of PKC-dependent transduction pathways, obtained with the inhibitor chelerytrhine, the inhibitor peptide of PKCzeta isoform, or chronic exposure to phorbol esters, does not prevent TNFalp…

Expression and developmental regulation of the cystine/glutamate exchanger (xc-) in the rat.

2007

The cystine/glutamate exchanger (antiporter x c − ) is a membrane transporter involved in the uptake of cystine, the rate-limiting amino acid in the synthesis of glutathione. Recent studies suggest that the antiporter plays a role in the slow oxidative excitotoxity and in the pathological effects of β-N-oxalylamino-l-alanine, the molecule responsible for neurolathyrism, a neurotoxic upper motor neuron disease. The mouse cystine/glutamate exchanger has been cloned and showed to be composed of two distinct proteins, one of which being a novel protein, named xCT, of 502 amino acids and 12 putative trans-membrane domains. We have generated and purified a polyclonal antibody to mouse xCT and stu…