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Background The aim of this study was to develop and characterize standardized in vitro three-dimensional organotypic models of human junctional epithelium ( JE) and sulcular epithelium ( SE). Methods Organotypic models were constructed by growing human normal gingival keratinocytes on top of collagen matrices populated with gingival fibroblasts ( GF) or periodontal ligament fibroblasts ( PLF). Tissues obtained were harvested at different time points and assessed for epithelial morphology, proliferation (Ki67), expression of JE-specific markers ( ODAM and FDC- SP), cytokeratins ( CK), transglutaminase, filaggrin, and basement membrane proteins (collagen IV and laminin1). Results The epithelial component in 3- and 5-day organotypics showed limited differentiation and expressed Ki-67, ODAM, FDC- SP, CK 8, 13, 16, 19, and transglutaminase in a similar fashion to control JE samples. PLF supported better than GF expression of CK19 and suprabasal proliferation, although statistically significant only at day 5. Basement membrane proteins started to be deposited only from day 5. The rate of proliferating cells as well as the percentage of CK19-expressing cells decreased significantly in 7- and 9-day cultures. Day 7 organotypics presented higher number of epithelial cell layers, proliferating cells in suprabasal layers, and CK expression pattern similar to SE. Conclusion Both time in culture and fibroblast type had impact on epithelial phenotype. Five-day cultures with PLF are suggested as JE models, 7-day cultures with PLF or GF as SE models, while 9-day cultures with GF as gingival epithelium ( GE) models. Such standard, reproducible models represent useful tools to study periodontal bacteria-host interactions in vitro. [ABSTRACT FROM AUTHOR]

Lymphangiogenesis, the formation of new lymphatics, is associated with chronic inflammation and tissue injury, and its role is to enhance lymphatic flow, immune cell transport, and antigen clearance. It is unknown if lymphangiogenesis takes place during periodontal disease development, and we hypothesized that growth of lymphatic vessels occurs in gingiva during development of periodontitis in mice. Inflammation was induced in gingiva with Porphyromonas gingivalis gavage, and bone resorption was verified after 42 days. Growth of lymphatic and blood vessels was measured after immunofluorescent staining with LYVE-1 and CD31. Expression of vascular endothelial growth factors and 2 inflammatory cytokines was investigated 10 days post-infection. Gingival lymphangiogenesis was found 10 days and 42 days post-infection, but proliferation of vessels was observed only in the shortest observation period. Epithelial expression of vascular growth factors (VEGF) A, C, and D was observed in gingiva, and increased numbers of immune cells expressing VEGF-C were found after infection, along with up-regulation of IL-1β and TNF-α at protein levels. We conclude that lymphangiogenesis takes place in gingiva during periodontal disease development, and that up-regulation of vascular growth factor C in recruited immune cells is likely important for the growth of lymphatic vessels. [ABSTRACT FROM PUBLISHER]

Elamin A, Albandar JM, Poulsen K, Ali RW, Bakken V. Prevalence ofAggregatibacter actinomycetemcomitans in Sudanese patients with aggressive periodontitis: a case-control study. J Periodont Res 2011; 46: 285-291.© 2011 John Wiley & Sons A/S Aggregatibacter actinomycetemcomitans is considered a possible etiological agent for aggressive periodontitis. The aim of this study was to determine the prevalence of the JP2 clone and non-JP2 genotypes of A. actinomycetemcomitans in the subgingival plaque of patients with aggressive periodontitis and controls among Sudanese high-school students. In a previous study we examined a large representative sample of students attending high schools in Khartoum, Sudan. In this population, 17 patients with aggressive periodontitis and 17 controls (14-19 years of age) consented to participate in the present study. The subjects underwent a clinical periodontal examination, and subgingival dental plaque samples were collected using paper points. The presence of the A. actinomycetemcomitans JP2 clone and non-JP2 genotypes were assessed using loop-mediated isothermal amplification (LAMP) and the PCR. The JP2 clone of A. actinomycetemcomitans was not detected in the subgingival plaque of either the cases or the controls. Non-JP2 types of A. actinomycetemcomitans were detected in the subgingival plaque of 12 (70.6%) patients with aggressive periodontitis and from only one (5.9%) control subject, showing a significantly higher frequency of detection in cases than in controls ( p = 0.0001). The odds ratio for the detection of A. actinomycetemcomitans in the subgingival plaque of the patients with aggressive periodontitis was 38.4 (95% confidence interval: 4.0-373.0; p = 0.002). The PCR and LAMP methods showed identical results pertaining to the identification of non-JP2 types of A. actinomycetemcomitans. The JP2 clone of A. actinomycetemcomitans was not detected in the subgingival plaque of high school subjects in Sudan. The detection of non-JP2 types of A. actinomycetemcomitans may be a useful marker of increased risk for development of aggressive periodontitis in young subjects. [ABSTRACT FROM AUTHOR]

Introduction: Fusobacterium nucleatum represents one of the predominant anaerobic species in the oral microbiota. Penicillin-resistant F. nucleatum have been isolated from intra- and extraoral infections. This study aimed to assess ampicillin resistance in F. nucleatum by investigating the synthesis of resistance-associated proteins. Methods: Ampicillin-resistant and ampicillin-susceptible F. nucleatum isolates were obtained from 22 dental plaque samples. Two-dimensional gel electrophoresis and mass spectrometry were used to investigate bacterial protein synthesis. Proteins exhibiting statistically significant quantitative changes between sensitive and resistant isolates were identified using peptide mass mapping and matrix-assisted laser desorption/ionization – time of flight/time of flight (MALDI-TOF/TOF) mass spectrometry. Results: Twenty-three F. nucleatum isolates were recovered from plaque samples and their ampicillin minimum inhibitory concentrations ranged between 0.125 μg/ml and 256 μg/ml. Analysis of the bacterial cellular proteins by two-dimensional gel electrophoresis resolved 154–246 distinct protein spots (mean 212, n = 9). Between 32% and 83% of the protein spots were common for the F. nucleatum isolates. Comparisons of the protein profiles of sensitive and resistant isolates revealed the presence of a 29 kDa protein and significant increases in the synthesis of two proteins at 37 and 46 kDa in the ampicillin-resistant F. nucleatum isolates. These proteins were identified as a class D β-lactamase, ATP-binding cassette (ABC) transporter ATP-binding protein and enolase, respectively. Conclusion: Synthesis of a class D β-lactamase by ampicillin-resistant F. nucleatum isolates could complicate antimicrobial treatment because these enzymes might confer resistance to many classes of β-lactam antibiotics. The differences observed in protein synthesis between ampicillin-resistant and ampicillin-susceptible F. nucleatum may contribute to the antibiotic resistance and virulence of these bacteria. [ABSTRACT FROM AUTHOR]

Introduction: Fusobacterium nucleatum represents one of the predominant anaerobic species in the oral microbiota. Penicillin-resistant F. nucleatum have been isolated from intra- and extraoral infections. This study aimed to assess ampicillin resistance in F. nucleatum by investigating the synthesis of resistance-associated proteins. Methods: Ampicillin-resistant and ampicillin-susceptible F. nucleatum isolates were obtained from 22 dental plaque samples. Two-dimensional gel electrophoresis and mass spectrometry were used to investigate bacterial protein synthesis. Proteins exhibiting statistically significant quantitative changes between sensitive and resistant isolates were identified using peptide mass mapping and matrix-assisted laser desorption/ionization – time of flight/time of flight (MALDI-TOF/TOF) mass spectrometry. Results: Twenty-three F. nucleatum isolates were recovered from plaque samples and their ampicillin minimum inhibitory concentrations ranged between 0.125 μg/ml and 256 μg/ml. Analysis of the bacterial cellular proteins by two-dimensional gel electrophoresis resolved 154–246 distinct protein spots (mean 212, n = 9). Between 32% and 83% of the protein spots were common for the F. nucleatum isolates. Comparisons of the protein profiles of sensitive and resistant isolates revealed the presence of a 29 kDa protein and significant increases in the synthesis of two proteins at 37 and 46 kDa in the ampicillin-resistant F. nucleatum isolates. These proteins were identified as a class D β-lactamase, ATP-binding cassette (ABC) transporter ATP-binding protein and enolase, respectively. Conclusion: Synthesis of a class D β-lactamase by ampicillin-resistant F. nucleatum isolates could complicate antimicrobial treatment because these enzymes might confer resistance to many classes of β-lactam antibiotics. The differences observed in protein synthesis between ampicillin-resistant and ampicillin-susceptible F. nucleatum may contribute to the antibiotic resistance and virulence of these bacteria. [ABSTRACT FROM AUTHOR]

Gingipains are potent virulence factors of Porphyromonas gingivalis and are likely to be associated with the development of periodontitis. It is, therefore, suggested that gingipain inhibition by vaccination could be a useful therapy for adult periodontitis. This study investigated the ability of antibodies raised against the catalytic part and the adhesin/haemagglutinin part of HRgpA to prevent haemagglutination and fibronectin degradation caused by P. gingivalis. We constructed two DNA vaccines, one containing the adhesin part of HRgpA and one with the catalytic part of HRgpA. BALB/c mice were immunized intramuscularly with either catalytic-part-encoding plasmids, adhesin-part-encoding plasmids or empty control plasmids. Sera from mice immunized with the catalytic vaccine or the adhesin vaccine each showed inhibition of human fibronectin degradation. A DNA vaccine encoding the adhesin or catalytic part of HRgpA induces responses that inhibit the degradation of molecules important for the structure and function of gingival and bone tissues. [ABSTRACT FROM AUTHOR]

Vågnes KS, Vågnes ØB, Vasstrand EN, Bakken V. Expression of the β-adhesin part of HRgpA in Sprague Dawley rats induces a specific antibody response. Oral Microbiol Immunol 2004: 19: 77–82. © Blackwell Munksgaard, 2004. The β-adhesin part of the Porphyromonas gingivalis W50 (ATCC 53978) protease HRgpA was cloned in an eukaryotic expression vector and expressed in COS-7 cells. The monoclonal antibody MAb (61BG1.3), specific for the hemagglutinating domain of β-adhesin, recognized the expressed β-adhesin in the transfected cells both by immunoblot and immunofluorescence. Sprague Dawley rats were immunized intramuscularly with β-adhesin encoding expression plasmid and expression plasmid without β-adhesin insert. Skeletal muscle tissue at the site of immunization in the β-adhesin immunized animals was shown to express this protein. The immunization induced a β-adhesin-specific antibody response. Sera from the immunized animals were tested for hemagglutination inhibiting activity. Due to high natural inhibiting activity in all rat sera tested, no increased hemagglutination inhibition was detected in sera from the β-adhesin immunized animals. [ABSTRACT FROM AUTHOR]

Summary 1.Although experimental studies show that organochlorines (OC) can affect bird behaviour, field assessments are invariably confounded by ecological differences between contaminated and uncontaminated sites. The behaviour of individual birds in the field has rarely been related to the contaminant burden. 2.We examined individual patterns of incubation and nest-site attentiveness in relation to OC burden, measured as polychlorinated biphenyl (PCB) concentration in the blood, of 27 glaucous gulls Larus hyperboreus in two breeding areas at Bear Island, in the north-eastern Atlantic. 3.Blood PCB concentrations ranged from 52 ng g-1 to 1079 ng g-1 (wet weight). There were significant differences between the two breeding areas, and females had significantly lower concentrations than males. 4.Gull behaviour differed significantly between breeding areas and sexes independently of PCB. Females incubated more than males (54% vs. 46%) but spent more time away from the nest site than males, both overall (23% vs. 12%) and when not incubating (50% vs. 21%). They were also absent for longer periods (4·5 vs. 2·8 h). Moreover, length of incubation bouts (6·4 vs. 4·4 h), the amount of time absent from the nest site when not incubating (51% vs. 25%) and length of absences (5·6 vs. 1·8 h) differed between breeding areas, probably due to different feeding specializations. 5.After controlling for these area and sex effects, the proportion of time absent from the nest site when not incubating, and the number of absences, were both significantly related to blood concentration of PCB. 6.Increased absence from the nest site in individual glaucous gulls with high blood concentrations of OC suggests effects on reproductive behaviour. We speculate that endocrine disruption or neurological effects might be involved, leading to increased energetic costs during incubation and reduced reproductive output. [ABSTRACT FROM AUTHOR]

We investigated the blood concentrations of organochlorines (OCs) and the diet of glaucous gulls Larus hyperboreus breeding in two neighbouring areas at Bear Island in the Barents Sea, north-eastern Atlantic. One area was situated on the edge of the large seabird cliff, about 100–150 m above sea level. The second area was about 1–2 km from the seabird cliff, and 10–50 m above sea level. In both 1997 and 1998 there were significant differences between the breeding areas for five OCs (HCB, HCH, Oxychlordan, DDE and PCB) measured, with the birds breeding on the cliff having higher levels. These differences were accompanied by a difference in diet between the areas. Birds in the former area had at least four times higher intake of guillemot Uria spp. eggs, while the birds near sea level seemed to have a much higher intake of fish. This study demonstrates the importance of feeding ecology for the distribution of OCs within populations. The results have important implications for the establishment of monitoring programs for OC contamination of the glaucous gull in the Arctic. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the antigenic abilities of Fusobacterium nucleatum strain ATCC 25586 and Porphyromonas gingivalis strain W50 black in- bred BALB/cABom mice immunized subcutaneously. Furthermore, we aimed to analyze whether the outer membranes (OM) and whole cells (WC) of F. nucleaturn or P. gingivalis had an effect on the levels of antibody response and whether a combination of both could either enhance or suppress the B-cell response. A single-cell assay, solid-phase enzyme-linked immunospo (ELISPOT), was used to analyze the splenic B-cell response (immunoglobulin A (IgA), IgG and IgM). Enzyme-linked immunosorbent assay (ELISA) and immunoblotting were used to verify the specific antibody response in the sera. A statistically significant lower level of spontaneous antibody production was observed in the group immunized with P. gingivalis OM compared with groups immunized with F. nucleatum and saline. The specific antibody titers measured by ELISA indicated that the bacterial preparations were able to induce IgG and IgM response. The preparations containing F. gingivalis OM induced higher humoral response than the preparations containing P. gingivalis WC, but for F. nucleatum such a difference was not observed. The prominent proteins revealed had apparent molecular masses of 40 kDa for F. nucleatum and 115, 55-56 and 43kDa for P. gingivalis whereas the immunoreactive proteins were 70, 65 and 40 kDa for mice immunized with F. nucleatum and 115, 55-56, 43 and 33-34 kDa for mice immunized with P. gingivalis. Quantitative analysis of B-cell response at the single cell level with ELISPOT revealed that some component (s) of P. gingivalis OM may have a suppressive ability on splenocytes incubated for a short time. [ABSTRACT FROM AUTHOR]

Mucosal immunization can induce immune responses different from those induced by systemic immunization. In this study, murine immune responses were analysed after immunization through gastric and subcutaneous routes with Mycobacterium bovis BCG. The number of circulating cells secreting antigen-specific immunoglobulins (Ig), and the number of gamma interferon (IFN-γ) secreting cells in spleen-cell cultures after in vitro stimulation with mycobacterial antigens were analysed at the single cell level by the ELISPOT method. Levels of antigen-specific antibodies in sera were determined by ELISA. In the subcutaneously immunized mice the authors found approximately 100 times more splenic cells secreting antigen-specific IgG than in gastrically immunized mice or control mice. Their levels of antigen-specific IgG in sera were 66-6700 times higher than in sera from gastrically immunized mice or control mice. In contrast, the numbers of IFN-γ producing cells in spleen-cell cultures after in vitro activation with BCG were equally high in the immunized groups of mice, and for both groups higher than in non-immunized controls. Furthermore, IFN-γ producing cells could be demonstrated in gastrically immunized animals even without in vitro activation. The results demonstrate that gastric immunization with the BCG vaccine can induce a systemic T cell-mediated immune response against mycobacterial antigens. [ABSTRACT FROM AUTHOR]

Copyright of Il Nuovo Cimento: A is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Il Nuovo Cimento: A is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Il Nuovo Cimento: A is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Il Nuovo Cimento: B is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)