Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0014118 (endocarditis)
 15,629 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lipoteichoic acid (LTA), a component of the cell wall of most gram-positive bacteria, has been shown to play a significant role in the initiation and progression of bacterial infection. However, little is known of its position in the cytokine network involved in the induction and perpetuation of inflammation. In this study, we assessed whether the macrophage activating and chemotactic cytokine macrophage inflammatory protein-1 alpha (MIP-1 alpha) was expressed in the setting of localized gram-positive infection. Furthermore, we determined whether LTA purified from either Staphylococcus aureus or Streptococcus pyogenes could induce the expression of MIP-1 alpha mRNA and protein from human blood monocytes. Immunohistochemical staining of human endocardial samples obtained from patients with acute S. aureus endocarditis revealed cell-associated MIP-1 alpha expression by neutrophils, macrophages, and fibroblasts. Treatment of human peripheral blood monocytes in vitro with LTA isolated from either S. aureus or S. pyogenes resulted in both the time- and dose-dependent expression of MIP-1 alpha mRNA. Similarly, staphylococcal and streptococcal LTA induced the dose-dependent production of MIP-1 alpha protein after 24 h in culture. These studies suggest that LTA may play an important role in triggering the recruitment and activation of leukocytes that characterizes the host response to gram-positive bacterial invasion.
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PMID:Macrophage inflammatory protein-1 alpha expression in vivo and in vitro: the role of lipoteichoic acid. 799 29

A total of 266 patients with degree I primary chronic septic endocarditis concurrent with acquired heart disease and 101 apparently healthy subjects were examined. The patients were found to have scarce T helper cells and higher levels of T suppressors (quite the reverse in some patients), decreased proliferative responses of T and B cells and normal levels of circulating immune complexes. It was conceived that there was a block in the synthesis of specific antibodies and a decrease in their affinity. It was proposed that cytokine (enzyme) genes (initiators or repressors) should be exposed at intervals as immunomodulating therapy of immune diseases, as well as in some hereditary diseases.
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PMID:[The immunological aspects of primary chronic septic endocarditis in acquired heart defects. The treatment approaches]. 814 15

Viridans streptococci are a heterogeneous group of gram-positive bacteria that are normal inhabitants of the mouth. These organisms are thought to contribute significantly to the etiology of infective endocarditis, although recently they have been implicated in serious infections in other settings. Another group of oral bacteria, gram-negative anaerobes, is associated with chronic dental infections, such as periodontal diseases or endodontic lesion formation. We evaluated the ability of the oral pathogens Streptococcus mutans and Porphyromonas endodontalis to induce a pathogenic response in vivo, with the goal of quantifying the inflammatory response in soft tissue by measuring leukocyte recruitment and hard tissues by measuring osteoclastogenesis. S. mutans induced a strong inflammatory response and was a potent inducer of osteoclast formation, while P. endodontalis was not. To further study the mechanisms by which P. endodontalis and S. mutans elicit significantly different levels of inflammatory responses in vivo, we tested the capacity of each to induce production of cytokines by mononuclear cells in vitro. S. mutans stimulated high levels of interleukin-12 (IL-12), gamma interferon (IFN-gamma), and tumor necrosis factor alpha (TNF-alpha), all of which are associated with inflammation, enhanced monocyte function, and generation of a Th1 response. In contrast, P. endodontalis stimulated production of IL-10 but not of TNF-alpha, IL-12, or IFN-gamma. These results demonstrate that oral pathogens differ dramatically in their abilities to induce inflammatory and immunoregulatory cytokines. Moreover, there is a high degree of correlation between the cytokine profile induced by these bacteria in vitro and their pathogenic capacity in vivo.
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PMID:Bacterium-dependent induction of cytokines in mononuclear cells and their pathologic consequences in vivo. 1022 64

There are numerous reports documenting the correlation between Streptococcus bovis bacteraemia and endocarditis in conjunction with colonic diseases. The adherence of S. bovis to either buccal or intestinal epithelial cells seems to be the initial process in colonization and subsequent infection of the host, allowing further adhesion of S. bovis to either endothelial cells or extracellular matrix components which leads to infective endocarditis. Bacterial entry at tumour sites is further assisted by the local action of cytokines that promotes vasodilatation and increased capillary permeability. Thus the ability of S. bovis to adhere to and to stimulate human cells may contribute to the pathogenicity of this bacteria. In the present study, we have shown the ability of S. bovis and wall-extracted antigens (WEA) to adhere to human buccal (KB) or intestinal (Caco-2) epithelial cell lines, to human saphenous vein endothelial cells, to human monocytic cell line (THP-1) and to extracellular matrix components (ECM) (fibronectin, collagen and laminin). The fixation of S. bovis on cells was followed by the synthesis of IL-8 from all the cells except Caco-2, whereas S. bovis WEA was able to induce cytokine synthesis from all of them, showing the immunomodulatory effect of S. bovis and S. bovis WEA on different cells.
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PMID:Production of cytokines by monocytes, epithelial and endothelial cells activated by Streptococcus bovis. 1062 39

A 52-year-old male with coronary artery disease was admitted with acute aortic valve endocarditis and a temperature up to 39.5 degrees C caused by Staphylococcus aureus. The patient was treated with ticlopidine (Tiklyd) after percutaneous transluminal coronary angioplasties to reduce restenosis by inhibiting thrombocyte aggregation. Upon admission c-reactive protein (CRP) was 389 mg/l. Interleukin-6 (IL-6) and Interleukin-2-receptor (IL-2-rec) were distinctly increased. Monoclonal antimyocardial antibodies were found. Leukocyte count never exceeded 9.8 G/l; however, transesophageal echocardiography validated a soft vegetation of the aortic valve. Antibiotic therapy was initiated with imipenem, gentamicin and vancomycin; clarithromycin was added after five days. Temperature normalized after 24 days. The c-reactive protein decreased from 389 mg/l to 6 mg/l, and the elevated cytokine levels decreased accordingly. Agranulocytosis or pancytopenia by ticlopidine through a toxic mechanism have been described, which are normally reversible within three weeks; there has not yet been a description of a missing leukocyte response in endocarditis as in this case report. This is a special situation with lack of or impeded immunological response, which limits the use of ticlopidine, especially since a therapeutic alternative with clopidogrel is available.
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PMID:[Impediment of cellular immune response under treatment with ticlopidine in a patient with Staphylococcus aureus endocarditis]. 1101 74

Eighty-five patients with acquired heart diseases with and without infective endocarditis (IE) were examined. In one group of patients traditional therapy was supplemented by the Russian drug immunofan, a synthetic hexapeptide with immunomodulating, antiinflammatory, and detoxifying effects. A course consisted of 10 intramuscular injections every other day (1 ml of 0.005% solution). The drug was prescribed after immunological studies on a laser flow cytometer (Becton Dickinson, USA). Correction was carried out before and after the operation. The postoperative period was uneventful in patients treated with immunofan; the incidence of clinical manifestations of IE was decreased. The concentrations of cytokines (IL-1, IL-6, TNF-alpha) in the blood were increased in patients with IE. In patients treated with immunofan, the concentrations of cytokines were decreased and immune parameters were normalized. Changes in the cytokine status can be used as a laboratory test for evaluating the efficiency of treatment in cardiosurgical patients with IE.
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PMID:[Correction of secondary immunodeficiency as a method of prevention of suppurative-septic complications after surgery with artificial blood circulation]. 1122 Sep 36

Coxiella burnetii, an obligate intracellular bacterium, is the agent of Q fever. The chronic form of the disease is associated with the overproduction of interleukin-10 and deficient C. burnetii killing by monocytes. We hypothesized that the replication of C. burnetii inside monocytes requires a macrophage-deactivating cytokine such as interleukin-10. In the absence of interleukin-10, C. burnetii survived but did not replicate in monocytes. C. burnetii replication (measured 15 days) was induced in interleukin-10-treated monocytes. This effect of interleukin-10 is specific since transforming growth factor beta1 had no effect on bacterial replication. C. burnetii replication involves the down-modulation of tumor necrosis factor (TNF) release. First, interleukin-10 suppressed C. burnetii-stimulated production of TNF. Second, the addition of recombinant TNF to interleukin-10-treated monocytes inhibited bacterial replication. Third, the incubation of infected monocytes with neutralizing anti-TNF antibodies favored C. burnetii replication. On the other hand, deficient C. burnetii killing by monocytes from patients with chronic Q fever involves interleukin-10. Indeed, C. burnetii replication was observed in monocytes from patients with Q fever endocarditis, but not in those from patients with acute Q fever. Bacterial replication was inhibited by neutralizing anti-interleukin-10 antibodies. As monocytes from patients with endocarditis overproduced interleukin-10, the defective bacterial killing is likely related to endogenous interleukin-10. These results suggest that interleukin-10 enables monocytes to support C. burnetii replication and to favor the development of chronic Q fever.
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PMID:Interleukin-10 stimulates Coxiella burnetii replication in human monocytes through tumor necrosis factor down-modulation: role in microbicidal defect of Q fever. 1125 92

Streptococcus sanguis is the major causative organism of infective (bacterial) endocarditis but, surprisingly, almost nothing is known about how it induces endocardial inflammation. In earlier studies we have shown that many bacteria secrete potent cytokine-inducing or -inhibiting proteins. We have therefore isolated the material secreted by S. sanguis grown on blood agar or in broth culture and have tested its ability to induce human peripheral blood monocytes to synthesize pro-inflammatory cytokines. The activation of monocytes by the secreted components of S. sanguis was almost totally blocked by heat and trypsin treatment but not by the lipopolysaccharide-inactivating antibiotic, polymyxin B, suggesting that activity is due to secreted proteins. The activity of the secreted material was significantly reduced by anti-CD14 monoclonal antibodies suggesting that the active protein (or proteins) was binding to the CD14/Toll-like receptor (TLR)4 complex. Fractionation of the secreted proteins by high performance liquid chromatography (HPLC) identified two proteins as being responsible for the majority of the cytokine induction: a manganese-dependent superoxide dismutase and a 190 kDa protein, which could not be sequenced, but which was neither CshA nor the PI/II proteins. These proteins, or the receptors to which they bind, may be therapeutic targets and may allow the development of adjunctive therapies to prevent endocardial damage during the often prolonged treatment of infective endocarditis with antibiotics. In addition, blocking of CD14 may have some therapeutic benefit.
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PMID:Streptococcus sanguis secretes CD14-binding proteins that stimulate cytokine synthesis: a clue to the pathogenesis of infective (bacterial) endocarditis? 1185 41

Staphylococcus aureus is one of the most significant pathogens in human sepsis and endocarditis. S. aureus can initiate blood coagulation, leading to the formation of microthrombi and multiorgan dysfunction in sepsis, whereas in endocarditis the bacterium induces fibrin clots on the inner surface of the heart, so-called endocardial vegetations. In the present study, we show that live and heat-killed S. aureus bacteria are potent inducers of procoagulant activity in human peripheral blood mononuclear cells. Furthermore, purified peptidoglycan, the main cell wall component of S. aureus, induced procoagulant activity in mononuclear cells in a concentration-dependent fashion. The procoagulant activity in these cells was dependent on expression of tissue factor, since antibodies to tissue factor inhibited the effect of peptidoglycan. In mononuclear cells stimulated with peptidoglycan, reverse transcription-PCR showed tissue factor gene expression, and the gene product was detected by enzyme-linked immunosorbent assay. Finally, flow cytometry identified tissue factor at the surface of CD14-positive monocytes. Peptidoglycan is known to induce proinflammatory cytokine production in monocytes. The present investigation shows that peptidoglycan also activates the extrinsic pathway of coagulation by inducing the expression of tissue factor in these cells. This mechanism helps to explain the procoagulant activity, which plays such an important role in the pathogenicity of severe S. aureus infections.
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PMID:Peptidoglycan from Staphylococcus aureus induces tissue factor expression and procoagulant activity in human monocytes. 1201 Sep 95

Production of proinflammatory cytokines is implicated in the pathogenesis of viridans streptococcus-induced alpha-streptococcal shock syndrome and infective endocarditis. Streptococcus mutans, one of the opportunistic pathogens causing infective endocarditis, was reported previously to stimulate monocytes and epithelial and endothelial cells in vitro to produce various cytokines. We found that glucosyltransferases (GTFs) GtfC and GtfD of S. mutans stimulated predominantly the production of interleukin-6 (IL-6) from T cells cultured in vitro. The level of IL-6 but not of tumor necrosis factor alpha in blood was significantly elevated when rats were injected intravenously with S. mutans GS-5, whereas IL-6 was detected at a much lower level when rats were challenged with NHS1DD, an isogenic mutant defective in the expression of GTFs. The serum IL-6 level was elevated in patients with endocarditis caused by different species of viridans streptococci which express GTF homologues. Affinity column-purified GTFs reduced the levels of detectable IL-2 of T cells stimulated by another bacterial antigen, tetanus toxoid. These results suggested that GTFs might modulate the production of Th1-type cytokines and that GTFs of S. mutans play a significant role in stimulating the production of the proinflammatory cytokine IL-6 in vivo.
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PMID:Induction of cytokines by glucosyltransferases of streptococcus mutans. 1209 91


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