70 research outputs found
LABAS LAUKSAIMNIECĪBAS PRAKSES (LLP) IZSTRĀDE LATVIJAI
LLP nosacījumu izstrādes nepieciešamību nosaka:Latvijas lauku perspektīvā attīstība;ES nitrātu direktīva (EEC/91/676) ar mērķi samazināt un turpmāk novērst ūdens piesārņošanu no lauksaimniecības avotiem;« Baltijas jūras vides aizsardzības Helsinku konvencijas (HELCOM) pielikums III par lauksaimniecības izraisīto piesārņojumu. Tiek prasīts dalībvalstīm izstrādāt ieviešanas programmu līdz 2Q02.g. un paredzētos pasākumus izvērst līdz 2011.gadam
Modulation of Kv Channel Expression and Function by TCR and Costimulatory Signals during Peripheral CD4+ Lymphocyte Differentiation
Ionic signaling pathways, including voltage-dependent potassium (Kv) channels, are instrumental in antigen-mediated responses of peripheral T cells. However, how Kv channels cooperate with other signaling pathways involved in T cell activation and differentiation is unknown. We report that multiple Kv channels are expressed by naive CD4+ lymphocytes, and that the current amplitude and kinetics are modulated by antigen receptor–mediated stimulation and costimulatory signals. Currents expressed in naive CD4+ lymphocytes are consistent with Kv1.1, Kv1.2, Kv1.3, and Kv1.6. Effector CD4+ cells generated by optimal TCR and costimulation exhibit only Kv1.3 current, but at approximately sixfold higher levels than naive cells. CD4+ lymphocytes anergized through partial stimulation exhibit similar Kv1.1, Kv1.2, and/or Kv1.6 currents, but approximately threefold more Kv1.3 current than naive cells. To determine if Kv channels contribute to the distinct functions of naive, effector, and anergized T cells, we tested their role in immunoregulatory cytokine production. Each Kv channel is required for maximal IL-2 production by naive CD4+ lymphocytes, whereas none appears to play a role in IL-2, IL-4, or IFN-γ production by effector cells. Interestingly, Kv channels in anergized lymphocytes actively suppress IL-4 production, and these functions are consistent with a role in regulating the membrane potential and calcium signaling
The Liver Plays a Major Role in Clearance and Destruction of Blood Trypomastigotes in Trypanosoma cruzi Chronically Infected Mice
Intravenous challenge with Trypanosoma cruzi can be used to investigate the process and consequences of blood parasite clearance in experimental Chagas disease. One hour after intravenous challenge of chronically infected mice with 5×106 trypomastigotes, the liver constituted a major site of parasite accumulation, as revealed by PCR. Intact parasites and/or parasite remnants were visualized at this time point scattered in the liver parenchyma. Moreover, at this time, many of liver-cleared parasites were viable, as estimated by the frequency of positive cultures, which considerably diminished after 48 h. Following clearance, the number of infiltrating cells in the hepatic tissue notably increased: initially (at 24 h) as diffuse infiltrates affecting the whole parenchyma, and at 48 h, in the form of large focal infiltrates in both the parenchyma and perivascular spaces. Phenotypic characterization of liver-infiltrating cells 24 h after challenge revealed an increase in Mac1+, CD8+ and CD4+ cells, followed by natural killer (NK) cells. As evidence that liver-infiltrating CD4+ and CD8+ cells were activated, increased frequencies of CD69+CD8+, CD69+CD4+ and CD25+CD122+CD4+ cells were observed at 24 and 48 h after challenge, and of CD25−CD122+CD4+ cells at 48 h. The major role of CD4+ cells in liver protection was suggested by data showing a very high frequency of interferon (IFN)-γ-producing CD4+ cells 24 h after challenge. In contrast, liver CD8+ cells produced little IFN-γ, even though they showed an enhanced potential for secreting this cytokine, as revealed by in vitro T cell receptor (TCR) stimulation. Confirming the effectiveness of the liver immune response in blood parasite control during the chronic phase of infection, no live parasites were detected in this organ 7 days after challenge
Regulatory T cells and their role in rheumatic diseases: a potential target for novel therapeutic development
Regulatory T cells have an important role in limiting immune reactions and are essential regulators of self-tolerance. Among them, CD4+CD25high regulatory T cells are the best-described subset. In this article, we summarize current knowledge on the phenotype, function, and development of CD4+CD25high regulatory T cells. We also review the literature on the role of these T cells in rheumatic diseases and discuss the potential for their use in immunotherapy
Seni kerajinan keramik Pajetan Tabanan hubunganya dengan pengembangan pariwisata didaerah Bali
Produk kerajinan keramik yang dihasilkan yaitu jenis, fungsi produk, bahan, desain, tehnik yang dipergunakann dan diproses pembakaranya. adapun jenis dan fungsi produk yang dihasilkan adalah selain membuat jenis keramik gerabah sebagian besar membuat jenis keramik porselin
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