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)

Eight Haemophilus influenzae and four Haemophilus parainfluenzae strains, all freshly isolated from patients, were examined for histamine production. Histamine was produced by all the H. influenzae (0.06 microgram-2.6 micrograms/100 ml) and by two of the H. parainfluenzae strains (46.5-47.9 micrograms/100 ml). It is concluded that histamine which plays an important role in the pathogenesis of chronic aspecific respiratory diseases, may derive not only from degranulation of mast cells, but also produced by Haemophilus.
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PMID:Histamine production by Haemophilus. 260 41

Otitis media with effusion (OME) is a common middle ear inflammatory disease in the pediatric population. This article determines concentrations of three functionally and metabolically distinct inflammatory mediators in middle ear effusions (MEE) and corresponding plasma of children with OME. One hundred two patients (mean age, 4.9 years) with persistent OME were studied. Middle ear effusions were collected from all subjects and plasma from a subset at the time of tympanostomy tube insertion. Histamine was assayed radioisotopically, 13,14-dihydro-15-keto-prostaglandin F2 alpha (stable PGF2 alpha metabolite) by radioimmunoassay, and neutrophil chemotactic factor of anaphylaxis by modified Boyden chamber. Mean MEE levels of the mediators (39 +/- 13 ng/mL, 462 +/- 179 pg/mL, and 264% +/- 57% positive control, respectively) were markedly higher than those of corresponding plasma (0.5 +/- 0.1 ng/mL, 285 +/- 127 pg/mL, and 47% +/- 5% positive control, respectively). The mean histamine content of mucoid effusions (43.2 +/- 56.9 ng/mL) was significantly higher than that of purulent (22.5 +/- 10.5 ng/mL) and serous (17.9 +/- 16.8 ng/mL) effusions. Higher histamine levels were observed in effusions positive for Haemophilus influenzae when compared with those with other pathogenic isolates. The high concentrations of these mediators in MEE and their potential for inducing or sustaining the inflammatory process supports a role in the pathogenesis of OME.
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PMID:Inflammatory mediators in chronic otitis media with effusion. 304 37

The influence of Haemophilus influenzae on anaphylactic mediator release from ovalbumin-sensitized isolated guinea pig lungs was investigated. Lungs from H. influenzae-vaccinated animals released prostaglandins and thromboxanes following a smaller dose of ovalbumin than was effective in non-vaccinated animals. Histamine release was significantly increased in 4 day-vaccinated animals but not 1 or 10 days after vaccination, while broncho-constriction was potentiated in 1 and in 4 day-vaccinated animals. This increased histamine release was achieved following 2 micrograms ovalbumin. In contrast, doses of 10 micrograms and 1 mg ovalbumin respectively did not affect and decreased histamine release in the vaccinated group. The inhibition of anaphylactic mediator release by an infusion of 6 x 10(-9) M isoprenaline was significantly attenuated by H. influenzae vaccination. These results indicate an increased sensitivity to antigenic challenge and suggest that the functioning of beta-adrenoceptors was decreased as a result of H. influenzae vaccination.
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PMID:The effects of Haemophilus influenzae vaccination on anaphylactic mediator release and isoprenaline-induced inhibition of mediator release. 615 89

Haemophilus influenzae is a bacterium that can be isolated from the deeper airways of asthmatic patients. We investigated the effect of vaccination with H. influenzae on alpha and beta adrenoceptor function in guinea-pig tracheal spirals and lung parenchymal strips. The tracheal spirals from H. influenzae-vaccinated animals showed significantly less relaxation to isoproterenol as compared to controls, independent of whether the trachea was maximally contracted with carbachol or only exhibited an intrinsic tone. Furthermore, an increased contractile response to carbachol was observed in these spirals. To isoproterenol in the presence of a beta-2 adrenergic antagonist (H35/25), or to salbutamol alone, the tracheal preparations from H. influenzae-vaccinated animals also showed a decreased relaxation. These results suggest involvement of both beta-1 and beta-2 subtype adrenoceptors. On the other hand, lung parenchymal strips from vaccinated guinea-pigs relaxed significntly more to these drugs. This effect was not influenced by H35/25 but could be inhibited by phenoxybenzamine. Histamine-induced contraction did not differ between the groups. These results indicated that H. influenzae causes a partial blockade of the beta adrenoceptors in tracheal spirals and, therefore, may have important implications in asthmatic bronchitis. In contrast, parenchymal lung strips of the H. influenzae-pretreated group showed an increased relaxation.
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PMID:Effects of vaccination with Haemophilus influenzae on adrenoceptor function of tracheal and parenchymal strips. 696 3

The histamine content of tears of healthy sex- and age-matched subjects and patients affected by allergic or nonallergic inflammatory ocular diseases was determined through a new competitive reverse-phase high-performance liquid chromatography (HPLC) method. Tear samples from 50 healthy subjects, 30 patients affected by seasonal allergic conjunctivitis, 12 patients with bacterial conjunctivitis associated with Haemophilus influenzae and 8 patients with bacterial conjunctivitis associated with Streptococcus pneumoniae were analyzed for histamine concentration by O-phthaldialdehyde precolumn derivatization-based HPLC. In physiological conditions, the tear histamine content was low (2.26 ng/ml) and did not vary in relation to age and sex. Histamine levels were significantly higher in all the patients studied, to a greater extent in those affected by allergic (23.61 ng/ml) or Haemophilus influenzae-associated (21.53 ng/ml) conjunctivitis.
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PMID:Quantitative determination of histamine in tears during conjunctivitis by a novel HPLC method. 1500 42

Histophilus somni (Haemophilus somnus) is one of the key bacterial pathogens involved in the multifactorial etiology of the Bovine Respiratory Disease Complex. This Gram negative pleomorphic rod also causes bovine septicemia, thrombotic meningencephalitis, myocarditis, arthritis, abortion and infertility, as well as disease in sheep, bison and bighorn sheep. Virulence factors include lipooligosaccharide, immunoglobulin binding proteins (as a surface fibrillar network), a major outer membrane protein (MOMP), other outer membrane proteins (OMPs) and exopolysaccharide. Histamine production, biofilm formation and quorum sensing may also contribute to pathogenesis. Antibodies are very important in protection as shown in passive protection studies. The lack of long-term survival of the organism in macrophages, unlike facultative intracellular bacteria, also suggests that antibodies should be critical in protection. Of the immunoglobulin classes, IgG2 antibodies are most implicated in protection and IgE antibodies in immunopathogenesis. The immunodominant antigen recognized by IgE is the MOMP and by IgG2 is a 40 kDa OMP. Pathogenetic synergy of bovine respiratory syncytial virus (BRSV) and H. somni in calves can be attributed, in part at least, to the higher IgE anti-MOMP antibody responses in dually infected calves. Other antigens are probably involved in stimulating host defense or immunopathology as well.
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PMID:Histophilus somni host-parasite relationships. 1821 58