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

In order to isolate porcine alveolar macrophages and to quantitatively study the components of recovered lung fluid, a bronchoalveolar lavage technique in living pigs was developed. Lung lavage was performed after introducing a catheter through the mouth via the trachea in the diaphragmatical lobe. Thirty ml of phosphate-buffered saline (PBS) was introduced into the lung and the fluid was aspirated after one minute. Following this, another 15 ml of PBS was introduced into the lung and aspirated after one minute. The recovered volume of the second lavage averaged 15 ml (+/- 0.4 S.E.M.). Cells thus obtained from specific-pathogen-free (SPF) pigs were composed of 98% macrophages. Lavage fluids from conventionally bred pigs contained 67% macrophages, 17% neutrophilic granulocytes and about 16% lymphocytes, demonstrated by their morphology and acid phosphatase activity. The viability of the recovered cells was over 98% in both SPF and conventionally bred pigs. The dilution of the aspirated lung liquid was determined by using methylene blue in the introduced fluid. The calculated dilution factor of the recovered lavage fluid was 0.58 (S.E.M. 0.02). No influence was noticed on the number or composition of cells nor on the dilution factor when lung lavage was done in SPF pigs twice a week during a four week period. The protein concentration in lavage fluid from SPF pigs was 142 (SD +/- 26) mcg/ml. In conventionally bred pigs, however, a wide variation (276 +/- 229 mcg/ml) in protein content was noted. Lavage fluid supernatant of some animals had a bactericidal effect on Haemophilus pleuropneumoniae strain 13261, whereas no bactericidal effect was noted in other lavage samples.
 ...
PMID:A method for bronchoalveolar lavage in live pigs. 252 34

Periodontal disease is thought to be initiated by a bacterial infection and subsequently developed by immunopathological mechanisms thorough host-parasite interactions. The macrophage and lymphocyte are the major functional cell types in the lesion of the disease and participate in tissue destruction and alteration of the periodontal connective tissue as well as in host defense mechanisms. However, the detailed implications of macrophages in development of the disease is still unclear. The aim of this study was to gain more understanding of the functional role of macrophages in periodontal disease. In this study, we examined the inducing effects of sonicated extracts from some gram-negative and gram-positive bacteria associated with the pathogenesis of periodontal disease, including Bacteroides gingivalis, Fusobacterium nucleatum, Haemophilus actinomycetemcomitans, and Actinomyces viscosus, on activation of macrophage functions and IL-1 production by the macrophages from the mouse peritoneum. At a dose as low as 1 microgram/ml (dry weight) sonicated extracts from B. gingivalis induced an increase in acid phosphatase activity and in glucose consumption of mouse peritoneal macrophages in vitro. A significant increase in the acid phosphatase and in glucose consumption was observed in the cultures at 24 h and 48 h, respectively, after the addition of the sonicate. Sonicated extracts from A. viscosus, a gram-positive bacterium, as well as B. gingivalis, F. nucleatum, and H. actinomycetemcomitans, gram-negative ones, were able to induce the increase in acid phosphatase activity and in glucose consumption of the macrophages. These periodontopathic bacteria were found to strongly induce IL-1 production by the macrophages as early as 24 h after addition of the sonicates. A significant increase in the IL-1 production was observed at a dose of 1 microgram/ml of the sonicates. The inducing ability was equivalent to 1 microgram/ml Escherichia coli lipopolysaccharide. The highest production of IL-1 was observed in the macrophages treated with H. actinomycetemcomitans among these sonicates. Sonicated extracts from both gram-negative and gram-positive bacteria were able to induce the IL-1 production by macrophages from C3H/HeJ mice, which are LPS low-responders. These results suggest that periodontopathic bacteria have potent ability to induce macrophage activation and IL-1 production and that the activated macrophages may play an important role in development of periodontal disease.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:[Inducing effect of periodontopathic bacteria on activation of macrophage functions and production of interleukin-1 by mouse peritoneal macrophages]. 260 96

We examined the events associated with phagocytosis, lysis and digestion of Haemophilus influenzae type b (Hib) by subarachnoid leukocytes in infant rats with experimental Hib meningitis. In early stages of infection, large numbers of bacteria were attached to the surfaces of neutrophils and macrophages invaded the subarachnoid space and actively ingested Hib. The bacteria, coccobacillary in shape with an approximate length of 1.0 micrometers and 0.3 micrometer in width, were interiorized after fusion of leukocyte microplicae which had arisen around them. Ingested Hib were sequestered within large, membrane-bound vacuoles containing five or more microbes. Following the fusion of primary lysosomes with the membrane of the phagocytic vacuole, bacteria were lysed and degraded. In later stages of infection, macrophages possessed large numbers of inclusions containing extensively digested Hib and myelin figures. Histochemical analysis of subarachnoid leukocytes revealed that macrophages actively synthesized acid phosphatase and that this enzyme aided in the digestion of phagocytosed bacteria. Peroxidase was also demonstrated within phagocytic vacuoles of neutrophils. Our results suggest that subarachnoid macrophages and neutrophils actively lyse and digest ingested Hib through the direct action of their hydrolytic enzymes.
 ...
PMID:Ultrastructural histopathology of experimental Haemophilus influenzae type B meningitis in the infant rat. II. Phagocytosis and lysis of microorganisms by leptomeningeal leukocytes. 697 44

The function of the streptococcal cytoplasmic membrane lipoprotein, LppC, was identified with isogenic Streptococcus equisimilis H46A and Escherichia coli JM109 strain pairs differing in whether they contained [H46A and JM109(pLPP2)] or lacked (H46A lppC::pLPP10 and JM109) the functional lppC gene for comparative phosphatase determinations under acidic conditions. lppC-directed acid phosphatase activity was demonstrated zymographically and by specific enzymatic activity assays, with whole cells or cell membrane preparations as enzyme sources. LppC acid phosphatase showed optimum activity at pH 5, and the enzyme activity was unaffected by Triton X-100, L-(+)-tartaric acid, or EDTA. Database searches revealed significant structural homology of LppC to the Streptococcus pyogenes LppA, Flavobacterium meningosepticum OplA, Helicobacter pylori HP1285, and Haemophilus influenzae Hel [e (P4)] proteins. These results suggest a possible function for these proteins and establish a novel function of streptococcal cell membrane lipoproteins.
 ...
PMID:Cytoplasmic membrane lipoprotein LppC of Streptococcus equisimilis functions as an acid phosphatase. 964 12

Haemophilus influenzae exists as a commensal of the upper respiratory tract of humans but also causes infections of contiguous structures. We describe the identification, localization, purification, and characterization of a novel, surface-localized phosphomonoesterase from a nontypeable H. influenzae strain, R2866. Sequences obtained from two CNBr-derived fragments of this protein matched lipoprotein e (P4) within the H. influenzae sequence database. Escherichia coli DH5alpha transformed with plasmids containing the H. influenzae hel gene, which encodes lipoprotein e (P4), produced high levels of a membrane-associated phosphomonoesterase. The isolated approximately 28-kDa enzyme was tartrate resistant and displayed narrow substrate specificity with the highest activity for arylphosphates, excluding 5-bromo-4-chloro-3-indolylphosphate. Optimum enzymatic activity was observed at pH 5.0 and only in the presence of divalent copper. The enzyme was inhibited by vanadate, molybdate, and EDTA but was resistant to inorganic phosphate. The association of phosphomonoesterase activity with a protein that has also been recognized as a heme transporter suggests a unique role for this unusual phosphohydrolase.
 ...
PMID:Outer membrane lipoprotein e (P4) of Haemophilus influenzae is a novel phosphomonoesterase. 1054 83

Haemophilus influenzae is an important respiratory tract pathogen. Toward understanding the progression of H. influenzae from commensal to pathogen, we need to understand the steps of colonization and infection, processes which must involve overcoming the normal host mucociliary clearance mechanism. A reliable method for the screening and quantitation of mucin-H. influenzae binding to allow for the assessment of the physiological variables significant to H. influenzae-mucin interactions in the normal and diseased conditions, will provide insight on how to intervene to prevent, inhibit, or treat infection. The current methods for enumeration of mucin-bound H. influenzae are labor intensive and rely on viable organisms. In this report, we present a new detection method, which reduces the number of variables, processing steps, and time involved, providing an economical, rapid, and reliable means to screen for and quantitate mucin-bound H. influenzae. Organisms are applied to mucin-coated microtiter wells for a set time; nonadherent organisms are removed with gentle rinses; wells are incubated with the phosphomonoesterase substrate p-nitrophenyl phosphate; and the absorbance, reflecting phosphatase activity of the mucin-bound organisms, is read at 410 nm in a microtiter plate reader against enzymatic activity calibration curves. All nonencapsulated and encapsulated H. influenzae tested exhibited significant acid phosphate activity within 20 min, which provided linear relationships with the numbers of organisms present. H. influenzae mucin binding characteristics obtained by this method were generally comparable to published data, and ranged from 10(3) to 10(6) organisms per well, depending on both strain of organism and type of mucin employed. This convenient, rapid and economical mucin adherence assay, will enable more extensive and comprehensive studies of the interactions of H. influenzae adhesins and specific ligands on mucin macromolecules, as well as the nonspecific means by which mucins function in preventing bacterial infection.
 ...
PMID:Acid phosphatase activity as a measure of Haemophilus influenzae adherence to mucin. 1057 7

Haemophilus influenzae is a common inhabitant of the upper respiratory tract and can cause serious infections of mucosal surfaces. Results from recent studies indicate that this pathogen possesses copious amounts of surface-localized phosphomonoesterase activity mediated by the bacterial lipoprotein e (P4). While the enzyme has previously been purified to apparent homogeneity, purification of large amounts of protein has been prevented by presence of N-terminal lipid modification. Recombinant DNA technology was employed to simultaneously replace the N-terminal lipid modification signal sequence with one for protein secretion without such modification and to place expression of the protein under the control of the T7-inducible promoter. Results from this work show that high levels of phosphomonoesterase activity were achieved after IPTG induction and purified to apparent homogeneity after two chromatography steps. Consistent with loss of the N-terminal lipid modification, the recombinant enzyme was easily extracted from the bacterial membrane and partitioned within the matrix of gel filtration chromatography resin while retaining a denatured molecular weight similar to that of wild-type e (P4). Results from physicochemical characterization suggest that the recombinant protein was similar to wild-type protein in SDS-PAGE-derived molecular weight, primary structure, substrate specificity, pH optimum, and sensitivity or resistance to various inhibitors. Acquisition of sufficient amounts of recombinant P4 was a prelude for studies to elucidate the structure and function of this unusual phosphomonoesterase.
 ...
PMID:Purification and characterization of a recombinant Haemophilus influenzae outer membrane phosphomonoesterase e (P4). 1060 Apr 58

Exogenous NAD utilization or pyridine nucleotide cycle metabolism is used by many bacteria to maintain NAD turnover and to limit energy-dependent de novo NAD synthesis. The genus Haemophilus includes several important pathogenic bacterial species that require NAD as an essential growth factor. The molecular mechanisms of NAD uptake and processing are understood only in part for Haemophilus. In this report, we present data showing that the outer membrane lipoprotein e(P4), encoded by the hel gene, and an exported 5'-nucleotidase (HI0206), assigned as nadN, are necessary for NAD and NADP utilization. Lipoprotein e(P4) is characterized as an acid phosphatase that uses NADP as substrate. Its phosphatase activity is inhibited by compounds such as adenosine or NMN. The nadN gene product was characterized as an NAD-nucleotidase, responsible for the hydrolysis of NAD. H. influenzae hel and nadN mutants had defined growth deficiencies. For growth, the uptake and processing of the essential cofactors NADP and NAD required e(P4) and 5'-nucleotidase. In addition, adenosine was identified as a potent growth inhibitor of wild-type H. influenzae strains, when NADP was used as the sole source of nicotinamide-ribosyl.
 ...
PMID:NADP and NAD utilization in Haemophilus influenzae. 1076 Jan 56

Haemophilus influenzae lipoprotein e (P4) is a member of the DDDD phosphohydrolase superfamily and mediates heme transport. Each of the aspartate residues of the signature motif is required for phosphomonoesterase activity, as none of the e (P4) single D mutants (D64A, D66A, D181N, and D185A) possessed detectable phosphomonoesterase activity. These results suggest that the signature motif is essential to the phosphomonoesterase activity of lipoprotein e (P4). When assessed for phosphomonoesterase-dependent heme transport activity in Escherichia coli hemA strains, plasmids containing D181N and D185A retained heme transport as indicated by aerobic growth while D64A and D66A did not. We conclude that phosphomonoesterase activity is not required for heme transport.
 ...
PMID:Contribution of the DDDD motif of H. influenzae e (P4) to phosphomonoesterase activity and heme transport. 1129 27

Lipoprotein e (P4) of Haemophilus influenzae is a phosphomonoesterase, encoded by the hel gene, that has been implicated in the acquisition of heme by this fastidious organism. However, lipoprotein e (P4) is also involved in the utilization of NAD and NMN. Some reports have concluded that the reported heme-related growth defect actually reflects a growth defect for NAD. In the current study, hel insertion mutants were constructed and a role for e (P4) in heme acquisition was demonstrated independent of its role in NAD or NMN acquisition. In addition, a rat model of infection demonstrated a role for e (P4) in the pathogenesis of invasive disease.
 ...
PMID:Lipoprotein e (P4) of Haemophilus influenzae: role in heme utilization and pathogenesis. 1754 24


1 2 Next >>