Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Gram-negative bacterium Haemophilus influenzae has been shown to cause a deterioration of the guinea pig pulmonary beta-adrenergic receptor system. In the present study we investigated further the mechanisms behind this effect. To this extent we evaluated the involvement of pulmonary macrophages (PM). Treatment of guinea pigs with killed H. influenzae bacteria resulted in the accumulation of a factor in the serum which could specifically stimulate PM. Thus stimulated, PM from nontreated animals caused a decrease of tracheal beta-adrenergic receptor function in vitro. This effect was evident by a decrease of the maximal response of the dose-response curves to isoprenaline, whereas the EC50 values did not change. Catalase and thiourea abolished the PM-induced effects, whereas superoxide dismutase did not, indicating that oxygen-centered radicals, in particular the highly reactive hydroxyl radical, may be responsible for the observed effects. In addition, dexamethasone also inhibited the decrease of tracheal beta-adrenergic receptor function. When activated PM, taken from animals that had been pretreated with killed H. influenzae bacteria 4 days beforehand, were stimulated with serum from a H. influenzae-treated animal, a potentiation of tracheal beta-adrenergic receptor function was observed.
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PMID:Dual effects of Haemophilus influenzae on guinea pig tracheal beta-adrenergic receptor function: involvement of oxygen-centered radicals from pulmonary macrophages. 303 75

The new ureas and thioureas of 15-membered azalides, N''-substituted 9a-(N'-carbamoyl-gamma-aminopropyl) (4), 9a-(N'-thiocarbamoyl-gamma-aminopropyl) (6), 9a-[N'-(beta-cyanoethyl)-N'-(carbamoyl-gamma-aminopropyl)] (8) and 9a-[N'-(beta-cyanoethyl)-N'-(thiocarbamoyl-gamma-aminopropyl)] (10) of 9-deoxo-9-dihydro-9a-aza-9a-homoerythromycin A (2), were synthesized and structurally characterized by NMR and IR spectroscopic methods and mass spectrometry. The new compounds were evaluated in vitro against a panel of erythromycin susceptible and erythromycin-resistant gram-positive and gram-negative bacterial strains. These compounds displayed an excellent overall antibacterial in vitro activity against erythromycin sensitive gram-positive strains, Streptococcus pneumoniae, Streptococcus pyogenes, Staphylococcus aureus, and good against negative strains, Moraxella catarrhalis and Haemophilus influenzae. In addition, several ureas with naphthyl substituents (4f, 4g, 4h) showed better activity in comparison to azithromycin against inducible resistant S. pyogenes. Ureas with naphthyl substituents 4g, 4h and thiourea 8h displayed moderate activity against constitutively resistant S. pneumoniae.
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PMID:Novel ureas and thioureas of 15-membered azalides with antibacterial activity against key respiratory pathogens. 1930 71