Patchy biofilm coverage can explain the potential advantage of BGAC reactors.

An adsorbing biofilm carrier, like granular activated carbon (GAC), can be the source of an extra flux of pollutant to the biofilm in addition to the bulk liquid. This double flux can improve the performance of a biological GAC (BGAC) reactor as compared to a nonabsorbing carrier reactor but only under conditions of pollutant partial penetration in the biofilm. Pollutant partial penetration in a biofilm often occurs in treatment processes where very low effluent concentrations are required.

Candida kunwiensis sp. nov., a yeast associated with flowers and bumblebees.

A novel asexual ascomycetous yeast, Candida kunwiensis (SG99-26T = KCTC 17041T = CBS 9067T), was isolated from sweet potato (Ipomoea batatas) flowers in Korea and from the body surface of pollinating bumblebees in Germany. Comparative analysis of the D1/D2 domain of 26S rDNA of all available sequences for ascomycetous yeasts showed that the novel species was phylogenetically related to the genus Metschnikowia, but the sequence similarity was low. Morphologically and physiologically, C.

The modulation of tissue factor by endothelial cells during heat shock.

Tissue factor (TF) initiates the extrinsic coagulation cascade on the surface of macrophages and endothelial cells. In septic patients, the extrinsic coagulation cascade is activated. When septic patients are febrile, mortality is decreased.

Streptococcus sanguis modulates type II collagen-induced arthritis in DBA/1J mice.

Native type II collagen is tolerogenic when given orally or i.p. to DBA/1J mice and induces autoimmune arthritis when given s.

Conflicting results obtained by RAPD-PCR and large-subunit rDNA sequences in determining and comparing yeast strains isolated from flowers: a comparison of two methods.

Sixty-six yeast strains isolated from the nectar of various plant species in Central Europe were characterized by randomly amplified polymorphic DNA PCR (RAPD-PCR) and by sequencing of the variable D1/D2 domain of large-subunit (26S) rDNA. The usefulness of both methods for the determination and comparison of unknown ascomycetous and basidiomycetous yeast strains was compared and evaluated. The reproducibility of RAPD-PCR was shown to be low and the information obtained by this method was clearly not as precise as that obtained from sequence analysis.

Coagulation and thrombosis in cardiovascular disease: plausible contributions of infectious agents.

An occlusive thrombus in the coronary arteries is the critical pathological event that immediately precedes most cases of myocardial infarction. Often the thrombus originates with a bleed from a fissured atheroma. Atheroma formation, therefore, creates risk of thrombosis; asymptomatic episodes of thrombosis and healing contribute to the pathogenesis of atherosclerosis and the development of atherosclerotic plaques.

Anti-fibrin antibody binding in valvular vegetations and kidney lesions during experimental endocarditis.

In Streptococcus sanguinis (sanguis) induced experimental endocarditis, we sought evidence that the development of aortic valvular vegetation depends on the availability of fibrin. Endocarditis was induced in New Zealand white rabbits by catheter placement into the left ventricle and inoculation of the bacteria. Fibrin was localized in the developing vegetation with 99mTechnetium (Tc)-labeled anti-fibrin antibody one or three days later.

Calprotectin expression in vitro by oral epithelial cells confers resistance to infection by Porphyromonas gingivalis.

Calprotectin, an S100 calcium-binding protein with broad-spectrum antimicrobial activity in vitro, is expressed in neutrophils, monocytes, and gingival keratinocytes. In periodontitis, calprotectin appears upregulated and is detected at higher levels in gingival crevicular fluid and tissue specimens. How calprotectin contributes to the pathogenesis of periodontal diseases is unknown.

Calprotectin expression inhibits bacterial binding to mucosal epithelial cells.

Squamous mucosal epithelial cells constitutively express calprotectin in the cytoplasm. To study how this antimicrobial protein complex confers epithelial resistance to invading bacteria, an epithelial cell line was stably transfected to express the calprotectin complex. Cells expressing calprotectin resist invasion by Listeria monocytogenes and Salmonella enterica serovar Typhimurium.

Calprotectin expression by gingival epithelial cells.

Calprotectin, a heterodimer of MRP8 and MRP14 with antimicrobial properties, is found in the cytosol of neutrophils, monocytes, and human gingival keratinocytes. During inflammation of the oral mucosa, the expression of immunoreactive calprotectin appears upregulated. Given the possible cell sources, we sought to learn if epithelial cells upregulate calprotectin in response to proinflammmatory agents.

Salivary film expresses a complex, macromolecular binding site for Streptococcus sanguis.

Teeth in the oral cavity are coated with a salivary film or pellicle, which lacks apparent intermolecular organization. This heterogeneous film facilitates binding of early commensal colonizing bacteria, including Streptococcus sanguis. To test the hypothesis that sufficient intermolecular organization exists in salivary films to form binding sites for S.

Streptococcal reporter gene-fusion vector for identification of in vivo expressed genes.

To study streptococcal genes that are specifically induced in the host during endocarditis, we have developed a novel plasmid for use in in vivo expression technology (IVET). This IVET uses an integration plasmid, pAK36, that carries dual (amy-cat) reporter genes. A gene-fusion strain library was constructed with the plasmid randomly inserted into the chromosome of Streptococcus gordonii V288 by insertion-duplication.

Emergence of antibiotic resistant Streptococcus sanguis in dental plaque of children after frequent antibiotic therapy.

Purpose: In the pediatric population, several different antibiotic regimens are currently recommended for the treatment of otitis media. This study investigated whether therapy for otitis media was associated with the emergence of antibiotic-resistant oral bacteria.

Methods: Streptococcus sanguis (S.

Streptococcus sanguis-induced platelet clotting in rabbits and hemodynamic and cardiopulmonary consequences.

By mimicking hemostatic structural domains of collagen, Streptococcus sanguis (aggregation-positive phenotype; Agg+) induces platelets to aggregate in vitro. To test the hypothesis that aggregation occurs in vivo, S. sanguis (Agg+ or Agg- suspension) was infused intravenously into rabbits.

A streptococcal adhesion system for salivary pellicle and platelets.

A Streptococcus sanguis 133-79 adhesin identified by the monoclonal antibody 1.1 (MAb 1.1) binds both saliva-coated hydroxylapatite (sHA) and platelets.

Dental plaque, platelets, and cardiovascular diseases.

Cardiovascular diseases, including atherosclerosis and myocardial ischemia, occur as a result of a complex set of genetic and environmental factors. During periodontitis, dental plaque microorganisms may disseminate through the blood to infect the vascular endothelium and contribute to the occurrence of atherosclerosis and risk of myocardial ischemia and infarction. Myocardial ischemia and infarction are often preceded by acute thromboembolic events.

Platelet-derived interleukin-1 induces cytokine production, but not proliferation of human vascular smooth muscle cells.

During vascular injury, such as observed in atherosclerosis, restenosis, vasculitides, transplantation, or sepsis, vascular smooth muscle cells (SMC) can be exposed to platelets or platelet products. Under these conditions proliferation or cytokine production of SMC stimulated by platelets or platelet products may contribute to regulation of vascular pathogenesis. Thus, we investigated interleukin-6 (IL-6) and IL-8 production as well as proliferation of SMC in response to platelets or platelet lysates.

Streptococcus sanguis expresses a 150-kilodalton two-domain adhesin: characterization of several independent adhesin epitopes.

Streptococcus sanguis binds to saliva-coated hydroxylapatite (sHA), an in vitro model of the enamel pellicle. To learn if more than one adhesin functions during adhesion, 12 reactive monoclonal antibodies (MAbs) were isolated by screening against both adhesive and nonadhesive strains. Two of these MAbs, 1.

Human vascular smooth muscle cells express interleukin-1beta-converting enzyme (ICE), but inhibit processing of the interleukin-1beta precursor by ICE.

Local immunoregulatory processes during normal vascular biology or pathogenesis are mediated in part by the production of and response to cytokines by vessel wall cells. Among these cytokines interleukin (IL)-1 is considered to be of major importance. Although vascular smooth muscle (SMC) and endothelial cells (EC) expressed both IL-1alpha and IL-1beta as cell-associated, 33-kilodalton (kD) precursors, SMC neither contained detectable mature IL-1beta, nor processed recombinant IL-1beta precursor into its mature 17-kD form.

Host-pathogen interactions in bacterial endocarditis: streptococcal virulence in the host.

To identify streptococcal genes that are expressed during experimental endocarditis, we developed a promoter-less dual reporter gene-fusion (amy, cat) plasmid, pAK36. Chromosomal DNA from S. gordonii V288 was digested with Sau3A1.

Characterization of prosomes in human lymphocyte subpopulations and their presence as surface antigens.

Prosomes, also called "multicatalytic proteinase" (MCP) or "proteasomes," are a new type of ubiquitous RNP particle present in some archeobacteria and in all eukaryotic cells tested from yeast to human. They were discovered as subcomplexes of untranslated messenger-ribonucleoproteins (mRNP) and later found to have a MCP activity putatively involved in antigen processing. Being composed of variable sets of characteristic proteins and associating small RNAs (pRNA), families of individual "mosaic" prosome particles seem to characterize the differentiation type and physiological state of individual cells and tissues.

Effects of Oral Flora on Platelets: Possible Consequences in Cardiovascular Disease.

During episodes of dental bacteremia, viridans group streptococci encounter platelets. Among these microorganisms, certain induce human and rabbit platelets to aggregate in vitro. In experimental rabbits, circulating streptococci induced platelets to aggregate, triggering the accumulation of platelets and fibrin into the heart valve vegetations of endocarditis.

Effects of oral flora on platelets: possible consequences in cardiovascular disease.

During episodes of dental bacteremia, viridans group streptococci encounter platelets. Among these microorganisms, certain Streptococcus sanguis induce human and rabbit platelets to aggregate in vitro. In experimental rabbits, circulating streptococci induced platelets to aggregate, triggering the accumulation of platelets and fibrin into the heart valve vegetations of endocarditis.