Effect of pH on the accumulation kinetics of pentachlorophenol in goldfish

During influenza A virus (IAV) infections, CD4+ T cell responses within infected lungs mainly involve T helper 1 (Th1) and regulatory T cells (Tregs). Th1-mediated responses favor the co-expression of T-box transcription factor 21 (T-bet) in Foxp3+ Tregs, enabling the efficient Treg control of Th1 responses in infected tissues. So far, the exact accumulation kinetics of T cell subsets in the lungs and lung-draining lymph nodes (dLN) of IAV-infected mice is incompletely understood, and the epigenetic signature of Tregs accumulating in infected lungs has not been investigated. Here, we report that the total T cell and the two-step Treg accumulation in IAV-infected lungs is transient, whereas the change in the ratio of CD4+ to CD8+ T cells is more durable. Within lungs, the frequency of Tregs co-expressing T-bet is steadily, yet transiently, increasing with a peak at Day 7 post-infection. Interestingly, T-bet+ Tregs accumulating in IAV-infected lungs displayed a strongly demethylated Tbx21 locus, similarly as in T-bet+ conventional T cells, and a fully demethylated Treg-specific demethylated region (TSDR) within the Foxp3 locus. In summary, our data suggest that T-bet+ but not T-bet− Tregs are epigenetically stabilized during IAV-induced infection in the lung.

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Sigmoid kinetics of purified beef heart mitochondrial carnitine palmitoyltransferase. Effect of pH and malonyl-CoA.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)90660-5 ◽

1984 ◽

Vol 259 (21) ◽

pp. 13084-13088 ◽

Cited By ~ 2

Author(s):

C J Fiol ◽

L L Bieber

Keyword(s):

Carnitine Palmitoyltransferase ◽

Beef Heart ◽

Effect Of Ph ◽

Malonyl Coa ◽

Kinetics Of

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The effect of pH on the reduction kinetics of P-680 in tris-treated chloroplasts

Biochimica et Biophysica Acta (BBA) - Bioenergetics ◽

10.1016/0005-2728(80)90206-6 ◽

1980 ◽

Vol 590 (3) ◽

pp. 353-359 ◽

Cited By ~ 114

Author(s):

Hélène Conjeaud ◽

Paul Mathis

Keyword(s):

Reduction Kinetics ◽

Effect Of Ph ◽

Kinetics Of

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Kinetics of mercury accumulation by freshwater biofilms

Environmental Chemistry ◽

10.1071/en17073 ◽

2017 ◽

Vol 14 (7) ◽

pp. 458 ◽

Cited By ~ 3

Author(s):

Perrine Dranguet ◽

Vera I. Slaveykova ◽

Séverine Le Faucheur

Keyword(s):

Food Webs ◽

Food Chain ◽

Microbial Composition ◽

Biofilm Thickness ◽

Aquatic Microorganisms ◽

Uptake Rate Constant ◽

The Difference ◽

Accumulation Kinetics ◽

Kinetics Of ◽

Hg Accumulation

Environmental contextMercury (Hg) is a major environmental contaminant due to its toxicity, accumulation and biomagnification along the food chain. We demonstrate that Hg accumulation by biofilms, one possible entry point for Hg into food webs, is rapid and depends on biofilm structure and composition. These findings have important implications for the understanding of Hg bioavailability and effects towards aquatic microorganisms. AbstractMercury contamination is of high concern due to its bioaccumulation, toxicity and biomagnification along the food chain. Biofilms can accumulate Hg and contribute to its incorporation in freshwater food webs. Nevertheless, the accumulation kinetics of Hg by biofilms is not well described and understood. The aim of the present study was thus to gain mechanistic understanding of Hg accumulation by biofilms. Kinetics of Hg uptake by biofilms of different ages (e.g. different compositions) was characterised by determining Hg contents in biofilms with and without a cysteine-washing step. Hg accumulation was rapid in both biofilms, with the uptake rate constant of the younger biofilm 10 times higher than that of the older biofilm. Moreover, accumulated Hg reached a plateau at 24h exposure in the younger biofilm, whereas it increased linearly in the older biofilm. The observed difference in Hg uptake by the studied biofilms is likely a result of the difference in biofilm thickness (and thus Hg diffusion inside the biofilm matrix) and microbial composition. These findings have important implications for the understanding of Hg bioavailability and effects towards aquatic microorganisms.

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