Fecal microbiota transplant (FMT) has emerged as a potential treatment for severe colitis associated with graft-versus-host disease (GvHD) following hematopoietic stem cell transplant. Bacterial engraftment from FMT donor to recipient has been reported, however the fate of fungi and viruses after FMT remains unclear. Here we report longitudinal dynamics of the gut bacteriome, mycobiome and virome in a teenager with GvHD after receiving four doses of FMT at weekly interval. After serial FMTs, the gut bacteriome, mycobiome and virome of the patient differ from compositions before FMT with variable temporal dynamics. Diversity of the gut bacterial community increases after each FMT. Gut fungal community initially shows expansion of several species followed by a decrease in diversity after multiple FMTs. In contrast, gut virome community varies substantially over time with a stable rise in diversity. The bacterium, Corynebacterium jeikeium, and Torque teno viruses, decrease after FMTs in parallel with an increase in the relative abundance of Caudovirales bacteriophages. Collectively, FMT may simultaneously impact on the various components of the gut microbiome with distinct effects.
The expression of the prophenoloxidase (proPO) gene was investigated in nine tissues of red swamp crayfish Procambarus clarkii, by real-time PCR after challenges by CpG oligodeoxynucleotide (ODN), Aeromonas hydrophila and white spot syndrome virus (WSSV). The results can be summarized as follows: (i) the expression level of the proPO gene in haemocytes was highest among nine studied tissues before the challenge; (ii) the expression of proPO increased in all studied tissues after stimulation by CpG ODN and WSSV, and also increased in all tissues, except the ovary, after the A. hydrophila challenge; (iii) the whole expression profiles were different, suggesting that different immune mechanisms may exist for crayfish that are resistant to WSSV and A. hydrophila, although the expression in haemocytes was similar before and after the WSSV and A. hydrophila challenges.
BackgroundNoise, nonlinear interactions, positive and negative feedbacks within signaling pathways, time delays, protein oligomerization, and crosstalk between different pathways are main characters in the regulatory of gene expression. However, only a single noise source or only delay time in the deterministic model is considered in the gene transcriptional regulatory system in previous researches. The combined effects of correlated noise and time delays on the gene regulatory model still remain not to be fully understood.ResultsThe roles of time delay on gene switch and stochastic resonance are systematically explored based on a famous gene transcriptional regulatory model subject to correlated noise. Two cases, including linear time delay appearing in the degradation process (case I) and nonlinear time delay appearing in the synthesis process (case II) are considered, respectively. For case I: Our theoretical results show that time delay can induce gene switch, i.e., the TF-A monomer concentration shifts from the high concentration state to the low concentration state ("on"→"off"). With increasing the time delay, the transition from "on" to "off" state can be further accelerated. Moreover, it is found that the stochastic resonance can be enhanced by both the time delay and correlated noise intensity. However, the additive noise original from the synthesis rate restrains the stochastic resonance. It is also very interesting that a resonance bi-peaks structure appears under large additive noise intensity. The theoretical results by using small-delay time-approximation approach are consistent well with our numerical simulation. For case II: Our numerical simulation results show that time delay can also induce the gene switch, however different with case I, the TF-A monomer concentration shifts from the low concentration state to the high concentration state ("off"→"on"). With increasing time delay, the transition from "on" to "off" state can be further enhanced. Moreover, it is found that the stochastic resonance can be weaken by the time delay.ConclusionsThe stochastic delay dynamic approach can identify key physiological control parameters to which the behavior of special genetic regulatory systems is particularly sensitive. Such parameters might provide targets for pharmacological intervention. Thus, it would be highly interesting to investigate if similar experimental techniques could be used to bring out the delay-induced switch and stochastic resonance in the stochastic gene transcriptional regulatory process.
Dissolved organic matter (DOM) was isolated from the hypersaline Da Qaidam Lake using solid-phase extraction (SPE) methods with five different adsorbents: ENVI-Carb (non-porous graphitized carbon), HLB, PPL, and XAD-8 (polymer based), and ENVI-18 (silica based). Structure-selective assessments of SPE-DOM isolated using the different adsorbents were conducted using a combination of complementary analysis techniques, including dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) analysis, as well as elemental analysis, Fourier transformed infrared spectroscopy (FTIR), H nuclear magnetic resonance (H NMR) and pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS). The results indicated that the modified polymer based adsorbents (PPL and HLB) exhibited higher DOC recoveries than the others. The PPL and ENVI-Carb cartridges can recover representative nitrogen-containing organic components from the hypersaline lake. The SPE-DOM isolates obtained using ENVI-18 and XAD-8 adsorbents contained higher proportions of purely aliphatic, alkene, and aromatic compounds; the ENVI-Carb and PPL adsorbents showed higher affinity for polar functionalized aliphatic and nitrogen-containing compounds; HLB isolate was enriched with oxygen-rich organic compounds and sulphur-bearing components. The structural and compositional features of SPE-DOM from the hypersaline Da Qaidam Lake indicated the predominately autochthonous sources of organic matter in the lake.
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