Simulation of the fate of the insecticide carbofuran in a rice field using a level IV fugacity model.

The object of this work was to verify the utility of a level IV fugacity model to simulate the environmental fate of the insecticide carbofuran when employed in the cultivation of irrigated rice. The model simulated the dynamic distribution of carbofuran in a system comprising of air, water, rice plants and the soil. The results indicated preferential compartments quality, and provided further knowledge of the fate of carbofuran in rice cultivation. Field experiments on rice were carried out to test the correspondence between simulated and measured carbofuran concentration in water and soil. Simulated concentrations had higher values in the compartments water > soil > rice plants > air. The model can be a useful tool for simulating the environmental fate of this insecticide and can be coupled with sensitivity and uncertainty analyses to test the influence of all input parameters on the outputs

Previsão do destino ambiental dos principais herbicidas aplicados na cultura do arroz.

RESUMO: Apresentamos a estimativa da distribuição ambiental dos principais herbicidas utilizados no cultivo de arroz irrigado. Foi utilizado o modelo de fugacidade nível I. Os compartimentos selecionados foram o ar, a água, a biota aquática, as plantas, o solo e o sedimento. Foram utilizadas características físico-químicas dos herbicidas tais como pressão de vapor, solubilidade em água, constante de Henry, coeficiente de partição do herbicida entre o octanol e a água e entre o carbono orgânico do solo e a solução do solo. São apresentados gráficos de barra descrevendo a distribuição percentual entre cada um dos herbicidas e os compartimentos selecionados

Previsão ambiental da distribuição dos pesticidas aplicados na cultura do arroz .

O objetivo do presente trabalho foi utilizar o modelo de fugacidade nível I como forma para auxiliar a avaliação preliminar da distribuição ambiental de fungicidas (carboxina, tiram e tebuconazol), herbicidas (2,4-D, dicloreto de paraquate, clomazona, propanil, quincloraque, bispiribaque-sódico e metsulfuron- metílico) e inseticidas (carbofurano, permetrina, fipronil e paration-metílico) aplicados na cultura do arroz. A metodologia utilizada incluiu basicamente as características físico-químicas dos pesticidas, os compartimentos ambientais e as equações de fugacidade. A avaliação preliminar do risco de contaminação pelo uso de pesticidas na cultura do arroz pode ser feita de forma expedita a partir das propriedades físico-químicas dos pesticidas, aplicando o modelo de fugacidade nível I. A água foi o compartimento ambiental que apresentou maior vulnerabilidade na preferência da distribuição dos pesticidas. O modelo de fugacidade nível I mostrou- se excelente ferramenta para ser utilizada como fator de decisão na escolha do pesticida a ser empregado no cultivo de arroz

CD28null CD4 T-cell expansions in autoimmune disease suggest a link with cytomegalovirus infection

Immunosenescence is thought to contribute to the increase of autoimmune diseases in older people. Immunosenescence is often associated with the presence of an expanded population of CD4 T cells lacking expression of CD28 (CD28null). These highly cytotoxic CD4 T cells were isolated from disease-affected tissues in patients with rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, or other chronic inflammatory diseases and their numbers appeared to be linked to disease severity. However, we recently demonstrated that the common herpes virus, cytomegalovirus (CMV), not ageing, is the major driver of this subset of cytotoxic T cells. In this review, we discuss how CMV might potentiate and exacerbate autoimmune disease through the expansion of CD28null CD4 T cells

Apoptotic Effects of Antilymphocyte Globulins on Human Pro-inflammatory CD4+CD28− T-cells

BACKGROUND: Pro-inflammatory, cytotoxic CD4(+)CD28(-) T-cells with known defects in apoptosis have been investigated as markers of premature immuno-senescence in various immune-mediated diseases. In this study we evaluated the influence of polyclonal antilymphocyte globulins (ATG-Fresenius, ATG-F) on CD4(+)CD28(-) T-cells in vivo and in vitro. PRINCIPAL FINDINGS: Surface and intracellular three colour fluorescence activated cell sorting analyses of peripheral blood mononuclear cells from 16 consecutive transplant recipients and short-term cell lines were performed. In vivo, peripheral levels of CD3(+)CD4(+)CD28(-) T-cells decreased from 3.7 ± 7.1% before to 0 ± 0% six hours after ATG-F application (P = 0.043) in 5 ATG-F treated but not in 11 control patients (2.9 ± 2.9% vs. 3.9 ± 3.0%). In vitro, ATG-F induced apoptosis even in CD4(+)CD28(-) T-cells, which was 4.3-times higher than in CD4(+)CD28(+) T-cells. ATG-F evoked apoptosis was partially reversed by the broad-spectrum caspase inhibitor benzyloxycarbonyl (Cbz)-Val-Ala-Asp(OMe)-fluoromethylketone (zVAD-fmk) and prednisolon-21-hydrogensuccinate. ATG-F triggered CD25 expression and production of pro-inflammatory cytokines, and induced down-regulation of the type 1 chemokine receptors CXCR-3, CCR-5, CX3CR-1 and the central memory adhesion molecule CD62L predominately in CD4(+)CD28(-) T-cells. CONCLUSION: In summary, in vivo depletion of peripheral CD3(+)CD4(+)CD28(-) T-cells by ATG-F in transplant recipients was paralleled in vitro by ATG-F induced apoptosis. CD25 expression and chemokine receptor down-regulation in CD4(+)CD28(-) T-cells only partly explain the underlying mechanism

The Antibody Targeting the E314 Peptide of Human Kv1.3 Pore Region Serves as a Novel, Potent and Specific Channel Blocker

Selective blockade of Kv1.3 channels in effector memory T (TEM) cells was validated to ameliorate autoimmune or autoimmune-associated diseases. We generated the antibody directed against one peptide of human Kv1.3 (hKv1.3) extracellular loop as a novel and possible Kv1.3 blocker. One peptide of hKv1.3 extracellular loop E3 containing 14 amino acids (E314) was chosen as an antigenic determinant to generate the E314 antibody. The E314 antibody specifically recognized 63.8KD protein stably expressed in hKv1.3-HEK 293 cell lines, whereas it did not recognize or cross-react to human Kv1.1(hKv1.1), Kv1.2(hKv1.2), Kv1.4(hKv1.4), Kv1.5(hKv1.5), KCa3.1(hKCa3.1), HERG, hKCNQ1/hKCNE1, Nav1.5 and Cav1.2 proteins stably expressed in HEK 293 cell lines or in human atrial or ventricular myocytes by Western blotting analysis and immunostaining detection. By the technique of whole-cell patch clamp, the E314 antibody was shown to have a directly inhibitory effect on hKv1.3 currents expressed in HEK 293 or Jurkat T cells and the inhibition showed a concentration-dependence. However, it exerted no significant difference on hKv1.1, hKv1.2, hKv1.4, hKv1.5, hKCa3.1, HERG, hKCNQ1/hKCNE1, L-type Ca2+ or voltage-gated Na+ currents. The present study demonstrates that the antibody targeting the E314 peptide of hKv1.3 pore region could be a novel, potent and specific hKv1.3 blocker without affecting a variety of closely related Kv1 channels, KCa3.1 channels and functional cardiac ion channels underlying central nervous systerm (CNS) disorders or drug-acquired arrhythmias, which is required as a safe clinic-promising channel blocker