Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023241 (Legionella)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A/J mouse macrophages infected with Legionella pneumophila and treated with gamma interferon (IFN-gamma) in vitro developed potent antimicrobial activity. This antilegionella activity was independent of the macrophage capacity to generate reactive oxygen intermediates, since the oxygen radical scavengers catalase, superoxide dismutase, mannitol, and thiourea had no effect on the antilegionella activity of IFN-gamma-activated macrophages. Likewise, whereas the ability of IFN-gamma-activated macrophages to synthesize reactive nitrogen intermediates was markedly inhibited by the L-arginine (Arg) analogs, NG-monomethyl-L-arginine and L-aminoguanidine, as well as by incubation in L-Arg-free medium, their ability to inhibit the intracellular growth of L. pneumophila remained intact. The intracellular growth of L. pneumophila in A/J macrophages was inhibited by the iron(III) chelator desferrioxamine and reversed by Fe-transferrin as well as by ferric salts. Additionally, IFN-gamma-activated macrophages incorporated 28% less 59Fe(III) compared with nonactivated cells. Nonetheless, only partial blocking of growth restriction was observed when IFN-gamma-stimulated macrophages were saturated with iron(III). Indole-propionic acid, which appears to inhibit the biosynthesis of L-tryptophan (L-Trp), was an L-Trp-reversible growth inhibitor of L. pneumophila in macrophages, implying that the intracellular replication of this pathogen is also L-Trp dependent. However, an excess of exogenous L-Trp did not reverse the growth inhibition due to IFN-gamma, though a small synergistic effect was observed when the culture medium was supplemented with both iron(III) and L-Trp. We conclude that IFN-gamma-activated macrophages inhibit the intracellular proliferation of L. pneumophila by reactive oxygen intermediate- and reactive nitrogen intermediate-independent mechanisms and just partially by nutritionally dependent mechanisms. We also suggest that additional mechanisms, still unclear, may be involved, since complete reversion was never obtained and since at higher concentrations of IFN-gamma, iron(III) did not induce any significant reversion in the L. pneumophila growth inhibition.
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PMID:Inhibition of Legionella pneumophila growth by gamma interferon in permissive A/J mouse macrophages: role of reactive oxygen species, nitric oxide, tryptophan, and iron(III). 803 89

Six new Cu(II), Ni(II), and VO(II) complexes (1-6) with Schiff base 1-phenyl-2,3-dimethyl-4-(1H-indole-3-carboxaldehyde)-3-pyrazolin-5-one (HL) were synthesized. The Schiff base was prepared through the condensation of 1-phenyl-2,3-dimethyl-4-amino-3-pyrazolin-5-one (antipyrine) with 1H-indole-3-carboxaldehyde. The new obtained compounds were characterized by (1)H NMR, (13)C NMR, UV-VIS, IR, EPR spectroscopy, elemental analysis, molar electric conductibility, magnetic susceptibility and thermal gravimetric analysis. In addition, the structure of the ligand HL has been determined by X-ray diffraction methods. The biological activity of complex compounds was investigated in terms of antibacterial effect on prokaryotic cells, by using paper disc diffusion technique, and for antiproliferative effect on eukaryotic cells, by monitoring mitotic activity in timelapse videomicroscopy experiments. The compounds were screened for their antibacterial activity against gram-positive bacteria (Staphylococcus aureus var. Oxford 6538, Klebsielle pneumoniae ATCC 100131 and Legionella monocytogenes ATCC 35182), gram-negative bacteria (Escherichia coli ATCC 10536, Pseudomonas aeruginosa ATCC 9027 and Salmonella typhimurium ATCC 14028) and anti-fungal activity (Candida albicans and Aspergillus flavus) using paper disc diffusion technique. The minimum inhibitory concentrations (MICs) of the compounds were also determined by agar streak dilution method. Compounds 3 and 4 proved to be the most effective as antibacterial agents. The antiproliferative activity was investigated by counting the number of mitoses for HeLa, and MCF7 cells. No significant antiproliferative effect was noted for HL and complex 2, for both used cell types. For complexes 1 and 3 complete inhibition of cell proliferation was observed in the case of HeLa cells, while the effects on MCF7 cell proliferation were lower. In conclusion, six new complex compounds were synthesized, and their biological activity investigated on both prokaryotic and eukaryotic cells, proving that some of them could be putative therapeutic substances.
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PMID:Synthesis and characterization of some new complexes of Cu(II), Ni(II) and V(IV) with Schiff base derived from indole-3-carboxaldehyde. Biological activity on prokaryotes and eukaryotes. 2251 25