178 research outputs found

    Biomass and Stored Carbohydrate Compensation after Above-Ground Biomass Removal in a Perennial Herb: Does Environmental Productivity Play a Role?

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    Many plant species are able to tolerate severe disturbance leading to removal of a substantial portion of the body by resprouting from intact or fragmented organs. Resprouting enables plants to compensate for biomass loss and complete their life cycles. The degree of disturbance tolerance, and hence the ecological advantage of damage tolerance (in contrast to alternative strategies), has been reported to be affected by environmental productivity. In our study, we examined the influence of soil nutrients (as an indicator of environmental productivity) on biomass and stored carbohydrate compensation after removal of aboveground parts in the perennial resprouter Plantago lanceolata. Specifically, we tested and compared the effects of nutrient availability on biomass and carbon storage in damaged and undamaged individuals. Damaged plants of P. lanceolata compensated neither in terms of biomass nor overall carbon storage. However, whereas in the nutrient-poor environment, root total non-structural carbohydrate concentrations (TNC) were similar for damaged and undamaged plants, in the nutrient-rich environment, damaged plants had remarkably higher TNC than undamaged plants. Based on TNC allocation patterns, we conclude that tolerance to disturbance is promoted in more productive environments, where higher photosynthetic efficiency allows for successful replenishment of carbohydrates. Although plants under nutrient-rich conditions did not compensate in terms of biomass or seed production, they entered winter with higher content of carbohydrates, which might result in better performance in the next growing season. This otherwise overlooked compensation mechanism might be responsible for inconsistent results reported from other studies

    2,2′,2′′,2′′′-[Pyridine-2,6-diylbis(methyl­ene­nitrilo)]tetra­ethanol

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    In the crystal structure of the title compound C15H27N3O4, the mol­ecule is located on a twofold axis and the asymmetric unit contains one half-mol­ecule, with one N and one C atom lying on the rotation axis. The pyridine ring is the hydrogen-bond acceptor, while two hydroxyl O atoms act as hydrogen-bond donors in intra­molecular O—H⋯N and intermolecular O—H⋯N and O—H⋯O hydrogen bonds, thereby forming a closed hydrogen-bonded cage

    Adamantane-1-thio­amide

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    The title compound, C11H17NS, is an important inter­mediate for the synthesis of biologically active adamantlythia­zolo-oxadiazo­les. The adamantyl residue is disordered about a twofold rotation axis over two sites with site-occupation factors of 0.817 (3) and 0.183 (3). The crystal structure is stabilized by inter­molecular N—H⋯S hydrogen-bonding inter­actions

    4-Methoxy­benzene­carbothio­amide

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    The asymmetric unit of the title compound, C8H9NOS, contains two independent mol­ecules with the meth­oxy groups oriented in opposite conformations. The mean planes of the carbothio­amide groups are tilted by 7.88 (15) and 11.16 (9)° from the mean planes of the benzene rings. In the crystal, the mol­ecules form dimers via intermolecular N—H⋯S inter­molecular hydrogen bonds, resulting in eight-membered rings of R 2 2(8) graph-set motif. The dimers are further linked by C—H⋯O hydrogen bonds into chains along the c axis. Adjacent chains inter­act through inter­molecular N—H⋯S hydrogen bonds, generating eight-membered rings of R 4 2(8) graph-set motif

    4-Methyl­benzene­carbothio­amide

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    In the title mol­ecule, C8H9NS, the mean plane of the carbothio­amide group is twisted slightly with respect to the mean plane of the benzene ring, making a dihedral angle of 17.03 (10)°. The crystal structure is stabilized by inter­molecular N—H⋯S hydrogen bonds, resulting in the formation of eight-membered rings lying about inversion centers and representing R 2 2(8) and R 4 2(8) motifs. Futhermore, these hydrogen bonds build up chains parallel to the b axis

    4-Bromo­thio­benzamide

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    The title compound, C7H6BrNS, crystallizes with two mol­ecules in the asymmetric unit. The dihedral angles between the aromatic ring and the thio­amide fragment are 23.6 (4) and 20.5 (3)° in the two mol­ecules. In the crystal, there are inter­molecular N—H⋯S hydrogen-bonding inter­actions between the amine group and the S atoms

    Lysate of Probiotic Lactobacillus casei DN-114 001 Ameliorates Colitis by Strengthening the Gut Barrier Function and Changing the Gut Microenvironment

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    BACKGROUND: Probiotic bacteria can be used for the prevention and treatment of human inflammatory diseases including inflammatory bowel diseases (IBD). However, the nature of active components and exact mechanisms of this beneficial effects have not been fully elucidated. Our aim was to investigate if lysate of probiotic bacterium L. casei DN-114 001 (Lc) could decrease the severity of intestinal inflammation in a murine model of IBD. METHODOLOGY/PRINCIPAL FINDINGS: The preventive effect of oral administration of Lc significantly reduces the severity of acute dextran sulfate sodium (DSS) colitis in BALB/c but not in SCID mice. In order to analyze how this beneficial effect interferes with well-known phases of intestinal inflammation pathogenesis in vivo and in vitro, we evaluated intestinal permeability using the FITC-labeled dextran method and analysed tight junction proteins expression by immunofluorescence and PCR. We also measured CD4(+)FoxP3(+) regulatory T cells proportion by FACS analysis, microbiota composition by pyrosequencing, and local cytokine production by ELISA. Lc leads to a significant protection against increased intestinal permeability and barrier dysfunction shown by preserved ZO-1 expression. We found that the Lc treatment increases the numbers of CD4(+)FoxP3(+) regulatory T cells in mesenteric lymph nodes (MLN), decreases production of pro-inflammatory cytokines TNF-α and IFN-γ, and anti-inflammatory IL-10 in Peyer's patches and large intestine, and changes the gut microbiota composition. Moreover, Lc treatment prevents lipopolysaccharide-induced TNF-α expression in RAW 264.7 cell line by down-regulating the NF-κB signaling pathway. CONCLUSION/SIGNIFICANCE: Our study provided evidence that even non-living probiotic bacteria can prevent the development of severe forms of intestinal inflammation by strengthening the integrity of intestinal barrier and modulation of gut microenvironment

    Safety and efficacy of the immunosuppressive agent 6-tioguanine in murine model of acute and chronic colitis

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    <p>Abstract</p> <p>Background</p> <p>Oral thiopurines are effective and widely used in treatment of inflammatory bowel disease (IBD) in humans, although their use is limited due the development of adverse events. Here, we examine the efficacy and toxicity of oral treatment with 6-tioguanine (6-TG) and azathioprine (AZA) in a murine model of IBD.</p> <p>Methods</p> <p>We induced acute or chronic colitis in BALB/c mice by one or four cycles of 3% dextran sulphate sodium (DSS), respectively. Mice were treated by daily gavages of various dosages of 6-tioguanine, azathioprine, or by phosphate buffered saline (PBS) starting the first day of DSS or after two cycles of DSS, respectively. We monitored the efficacy and toxicity by measuring the weight change and serum alanine aminotransferase (ALT) activity and by disease severity and histology, at the end of the experiment. Moreover, we measured cytokine production after colon fragment cultivation by enzyme-linked immunoabsorbent assay and numbers of apoptotic cells in the spleen by flow cytometry.</p> <p>Results</p> <p>6-TG is effective in the treatment of acute DSS-induced colitis in a dose-dependent manner and 40 μg of 6-TG is significantly more effective in the treatment of acute colitis than both AZA and PBS. This effect is accompanied by decrease of IL-6 and IFN-γ production in colon. We did not observe histological abnormalities in liver samples from control (PBS) or 6-TG treated mice. However, liver samples from most mice treated with AZA showed mild, yet distinct signs of hepatotoxicity. In chronic colitis, all thiopurine derivatives improved colitis, 20 μg of 6-TG per dose was superior. High doses of 6-TG led to significant weight loss at the end of the therapy, but none of the thiopurine derivatives increased levels of serum ALT. Both thiopurine derivatives reduced the proportion of apoptotic T helper cells, but a high production of both IL-6 and TGF-β was observed only in colon of AZA-treated mice.</p> <p>Conclusions</p> <p>Use of 6-TG in the treatment of experimental colitis in mice appears superior to AZA administration and placebo. In contrast to 6-TG, the use of AZA resulted in histological liver abnormalities.</p

    Facile heterocyclic synthesis and antimicrobial activity of polysubstituted and condensed pyrazolopyranopyrimidine and pyrazolopyranotriazine derivatives

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    Reaction of 6-amino-3-methyl-4-(substituted phenyl)-1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile (1) with triethylorthoformate followed by treatment with hydrazine hydrate, formic acid, acetic acid, phenylisocyanate, ammonium thiocyanate and formamide afforded the corresponding pyranopyrimidine derivatives 2–6. Cyclocondensation of 1 with cyclohexanone afforded pyrazolopyranoquinoline 7. One-pot process of diazotation and de-diazochlorination of 1 afforded pyrazolopyranotriazine derivative 8, which upon treatment with secondary amines afforded 9 and 10a-c. Condensation of 2 with aromatic aldehyde gave the corresponding Schiff bases 11a,b, the oxidative cyclization of the hydrazone with appropriate oxidant afforded 11-(4-fluorophenyl))-2-(4-substitutedphenyl)-10-methyl-8,11-dihydropyrazolo-[4\u27,3\u27:5,6]pyrano[3,2-e][1,2,4]triazolo[1,5-c]pyrimidines (12a,b). Structures of the synthesized compounds were confirmed by spectral data and elemental analysis. All synthesized compounds were evaluated for antibacterial and antifungal activities compared to norfloxacin and fluconazole as standard drugs. Compounds 9, 10c, 12a and 15 were found to be the most potent antibacterial agents, with activity equal to that of norfloxacin. On the other hand, compound 5 exhibited higher antifungal activity compared to fluconazole
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