ABSTRACT
Bacterial lipopolysaccharide (LPS) release during periodontal infection is a significant component of periodontal disease. We hypothesized that some bacterial LPS release results from bacterial exposure to antibiotics. Therefore, we examined the ability of various classes of antibiotics to induce LPS release from Porphyromonas gingivalis as well as the ability of antimicrobial peptides (AMPs) to inhibit purified LPS. All antibiotics tested against P. gingivalis were able to liberate 1.9-12.9 times more LPS as compared to untreated bacteria. Among the three AMPs tested, LL-37 was found to be the most potent inhibitor of cytokine (tumor necrosis factor-alpha, interleukin-1beta, interleukin-6) production and completely neutralized purified P. ginigivalis LPS activity in the chromogenic limulus amebocyte lysate (LAL) and whole blood cytokine stimulation assays. These observations suggest that therapeutic approaches utilizing AMPs as adjuncts to neutralize released LPS should be considered.
Subject(s)
Anti-Bacterial Agents/pharmacology , Antimicrobial Cationic Peptides/pharmacology , Cytokines/metabolism , Lipopolysaccharides/antagonists & inhibitors , Lipopolysaccharides/metabolism , Porphyromonas gingivalis/drug effects , Porphyromonas gingivalis/metabolism , Bacteroidaceae Infections/drug therapy , Blood Cells/drug effects , Blood Cells/metabolism , Cathelicidins/pharmacology , Cytokines/blood , Histatins/pharmacology , Humans , Limulus Test , Lipopolysaccharides/isolation & purification , Oligopeptides/pharmacology , Osmolar Concentration , Periodontitis/drug therapy , Protein Synthesis Inhibitors/pharmacology , Time FactorsABSTRACT
Only immature palmarosa (Cymbopogon martinii, Roxb. wats. var. motia) inflorescence with unopened spikelets accumulated essential oil substantially. Geraniol and geranyl acetate together constituted about 90% of the palmarosa oil. The proportion of geranyl acetate in the oil decreased significantly with a corresponding increase of geraniol, during inflorescence development. An esterase enzyme activity, involved in the transformation of geranyl acetate to geraniol, was detected from the immature inflorescence using a gas chromatographic procedure. The enzyme, termed as geranyl acetate cleaving esterase (GAE), was found to be active in the alkaline pH range with the optimum at pH 8.5. The catalysis of geranyl acetate was linear up to 6 h, and after 24 h of incubation, 75% of the geranyl acetate incubated was hydrolyzed. The GAE enzymic preparation, when stored at 4 degrees C for a week, was quite stable with only 40% loss of activity. The physiological role of GAE in the production of geraniol during palmarosa inflorescence development has been discussed.
Subject(s)
Acetates/metabolism , Poaceae/metabolism , Terpenes/metabolism , Acyclic Monoterpenes , Biotransformation , Chromatography, Gas , Oils, Volatile/metabolismABSTRACT
Multidrug-resistant tuberculosis is a major global health emergency. Cell wall lipids of Mycobacterium tuberculosis can play crucial roles in the pathogenesis. The enzymes involved in their synthesis can be ideal new drug targets against tuberculosis, because many such lipids are unique to this pathogen. A variety of multiple methyl-branched fatty acids are among such unique lipids. We have identified seven genes highly homologous to the mas gene, which is known to be involved in the production of one class of such multiple methyl-branched fatty acids. One of these mas-like genes, pks2, was disrupted using a phage-mediated delivery of the disruption construct. Gene disruption by homologous recombination was confirmed by polymerase chain reaction analysis of the flanking regions of the introduced disrupted gene and by Southern analysis. Thin-layer and radio gas-chromatographic analyses of lipids derived from [1-14C]propionic acid and gas chromatography/mass spectrometry analysis of the fatty acids and hydroxy fatty acids showed that the pks2 mutant was incapable of producing hepta- and octamethyl phthioceranic acids and hydroxyphthioceranic acids that are the major acyl constituents of sulfolipids. Consequently, pks2 mutant does not produce sulfolipids. Sulfolipid deficiency in pks2 mutant was confirmed by two-dimensional thin-layer chromatographic analysis of lipids derived from [1-14C]propionic acid and 35SO4(-2). With this sulfolipid-deficient mutant, it should be possible to test for the postulated important roles for sulfolipids in the pathogenesis of M. tuberculosis.
Subject(s)
Bacterial Proteins , Fatty Acid Synthases/genetics , Fatty Acid Synthases/metabolism , Lipids/biosynthesis , Mycobacterium tuberculosis/enzymology , Mycobacterium tuberculosis/genetics , Blotting, Southern , Carbon Radioisotopes , Gas Chromatography-Mass Spectrometry , Genes, Bacterial , Lipids/chemistry , Polymerase Chain Reaction , Propionates/metabolism , Recombinant Proteins/metabolism , Sequence Deletion , Substrate SpecificitySubject(s)
Respiration , Silicosis/diagnosis , Sputum/cytology , Humans , Respiratory Function Tests , Silicosis/physiopathologyABSTRACT
We present a study of 151 persons working in slate-pencil manufacturing industries located in the Mandsaur district of Madhya Pradesh, India. Cough, dyspnea, and pain in the chest were the important symptoms. Cyanosis, rhonchi, and crepitations were found in varying numbers of cases. The chest x-ray films were abnormal in 85 cases.
