Search results for "tolerance"
showing 10 items of 956 documents
The symbiosis between Nicotiana tabacum and the endomycorrhizal fungus Funneliformis mosseae increases the plant glutathione level and decreases leaf…
2015
Over time, anthropogenic activities have led to severe cadmium (Cd) and arsenic (As) pollution in several environments. Plants inhabiting metal(loid)-contaminated areas should be able to sequester and detoxify these toxic elements as soon as they enter roots and leaves. We postulated here that an important role in protecting plants from excessive metal(loid) accumulation and toxicity might be played by arbuscular mycorrhizal (AM) fungi. In fact, human exploitation of plant material derived from Cd- and As-polluted environments may lead to a noxious intake of these toxic elements; in particular, a possible source of Cd and As for humans is given by cigarette and cigar smoke. We investigated …
Plant virus evolution under strong drought conditions results in a transition from parasitism to mutualism
2021
Environmental conditions are an important factor driving pathogens’ evolution. Here, we explore the effects of drought stress in plant virus evolution. We evolved turnip mosaic potyvirus in well-watered and drought conditions in Arabidopsis thaliana accessions that differ in their response to virus infection. Virus adaptation occurred in all accessions independently of watering status. Drought-evolved viruses conferred a significantly higher drought tolerance to infected plants. By contrast, nonsignificant increases in tolerance were observed in plants infected with viruses evolved under standard watering. The magnitude of this effect was dependent on the plant accessions. Differences in to…
INFγ stimulates arginine transport through system y+L in human monocytes
2004
Freshly isolated human monocytes transport L-arginine mostly through a sodium independent, NEM insensitive pathway inhibited by L-leucine in the presence, but not in the absence of sodium. Interferon-gamma (IFNgamma) stimulates this pathway, identifiable with system y+L, and markedly enhances the expression of SLC7A7, the gene that encodes for system y+L subunit y+LAT1, but not of SLC7A6, that codes for the alternative subunit y+LAT2. System y+ plays a minor role in arginine uptake by monocytes and the expression of system y+-related genes, SLC7A1 and SLC7A2, is not changed by IFNgamma. These results demonstrate that system y+L is sensitive to IFNgamma.
The effect of birthplace on heat tolerance and mortality in Milan, Italy, 1980-1989
2006
The temperature–mortality relationship follows a well-known J-V shaped pattern with mortality excesses recorded at cold and hot temperatures, and minimum at some optimal value, referred as Minimum Mortality Temperature (MMT). As the MMT, which is used to measure the population heat-tolerance, is higher for people living in warmer places, it has been argued that populations will adapt to temperature changes. We tested this notion by taking advantage of a huge migratory flow that occurred in Italy during the 1950s, when a large number of unemployed people moved from the southern to the industrializing north-western regions. We have analyzed mortality–temperature relationships in Milan residen…
Mechanisms of resistance to autoimmune disease induced by T-cell vaccination.
1991
Many human autoimmune diseases tend to progress slowly. Phases of rapid progression may come to a halt and may be followed by transient or even permanent remissions. Autoimmune diseases in animals either arise spontaneously or are induced. The former tend to be slowly progressive, the latter mostly acute to subacute, and usually followed by spontaneous remissions. The mechanisms at work that prevent rapid disease progression and can effect remissions are poorly understood, but they may provide us with a clue both to natural self-tolerance and to the therapeutic induction of self-tolerance.
B7‐H1 and CD8+Treg: The enigmatic role of B7‐H1 in peripheral tolerance
2009
The interaction between B7-H1 (PD-L1) expressed on APC with PD-1 expressed by T cells was shown previously to result in inhibition of T-cell activation and autoimmune diseases. A paper in this issue of the European Journal of Immunology demonstrates that DC B7-H1 expression can in fact enhance autoimmunity, rather than suppress it. Using a model of direct injection of self antigen-loaded DC into the CNS, the authors demonstrate that DC with intact B7-H1 expression exacerbate CNS autoimmune disease. Importantly, the improved disease outcome in animals treated with B7-H1(-/-) DC is a result of a population of CD8(+) Treg cells that expand at the site of autoimmune inflammation.
TGF-β signalling is required for CD4⁺ T cell homeostasis but dispensable for regulatory T cell function.
2013
Signalling by the cytokine TGF-β regulates mature CD4+ T cell populations but is not involved in the survival and function of regulatory T cells.
Imigrantu Integrācija. Trešo kultūru bērni: Latvija un Vācija
2015
Arvien vairāk ģimeņu migrē, kļūstot par globāliem nomadiem un attīstot transnacionālu identitāti. Tāpēc lielāka uzmanība jāpievērš imigrantu bērniem, jo īpaši gados jaunāki cilvēki kļūst par trešās kultūras bērniem. Tā ir kultūra, kas ir atšķirīga no dzimtās zemes un mītnes zemes kultūras. Latvijā un Vācijā ir līdzīga problēma – izglītības sistēma nav pietiekami adaptēta imigrantu bērniem. Maģistra darba mērķis ir izpētīt konceptu „trešās kultūras bērni” un pieejamo informāciju par tešo valstu bērnu integrāciju abās valstīt, piemērojot kvalitatīvo pētniecības metodi, lai apkopotu un analizētu datus. Latvija un Vācija nesen sāka izstrādāt integrācijas politiku, lielāku uzmanību pievēršot pie…
Transcriptome changes induced by Arbuscular mycorrhizal symbiosis in leaves of durum wheat (Triticum durum Desf.) promote higher salt tolerance
2022
AbstractThe salinity of soil is a relevant environmental problem around the world, with climate change raising its relevance, particularly in arid and semiarid areas. Arbuscular Mycorrhizal Fungi (AMF) positively affect plant growth and health by mitigating biotic and abiotic stresses, including salt stress. The mechanisms through which these benefits manifest are, however, still unclear. This work aimed to identify key genes involved in the response to salt stress induced by AMF using RNA-Seq analysis on durum wheat (Triticum turgidum L. subsp. durum Desf. Husn.). Five hundred sixty-three differentially expressed genes (DEGs), many of which involved in pathways related to plant stress resp…
The anti-oxidant capacity of tumour glycolysis.
2009
In this mini-review data are summarised which provide evidence for the biological and clinical significance of tumour glycolysis and of its relationship to the redox state of cancer cells.Malignant transformation is associated with an overexpression of numerous glycolysis-related genes in the vast majority of human cancers. At the same time, glycolytic activity and glycolysis-linked metabolic milieu are often variable between individual tumours which induces large variations in treatment response and aggressiveness. Currently, there is no genetic or proteomic marker for the prediction of the therapeutic response for individual tumours, but the prognostic value of tumour lactate accumulation…