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  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of periodontal research 31 (1996), S. 0 
    ISSN: 1600-0765
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Serum rheumatoid factor (RF) level and peritoneal and splenic CD5+B (B-1) cells in mice were examined after intraperitoneal administration of purified lipopolysaccharides (LPS) from oral periodontopathic bacteria; Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum and Capnocytophaga ochracea. F. nucleatum and C. ochracea LPS induced higher levels of serum IgM- and IgG-RF, while P. gingivalis LPS showed the least induction. In addition, wet weights of spleen and serum IgM and IgG concentration were markedly increased in F. nucleatum LPS injected group. On the other hand, the proportion of CD5+ B cells to lymphocytes in the peritoneal cavity and spleen did not increase. The reason for this was not clear but conventional B cells (CD5+ B cells) might increase more rapidly with splenic enlargement than CD5+ B cells. These results suggested that RF induced by bacterial LPS may modulate immune responses against bacteria and plays an important role for defence and destruction of periodontal tissue.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1600-0765
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Cystatins are protein inhibitors of cysteine proteinases, which are believed to play an important role in the pathogenesis of periodontal disease. In this study, we report a new sensitive method for the quantitative analysis of cystatin activity in a small amount of crude sample such as gingival crevicular fluid. Cystatin activity in the crude sample was determined by using active site-titrated papain, which is a cysteine proteinase from the plant Carica papaya. Crude samples usually contain endogenous cysteine proteinases. These competed with the added papain for the active sites of the cystatins. The cystatin-cysteine proteinase complex was able to be dissociated by the addition of papain. This competition and dissociation could interfere with the determination of cystatin activity, since some of the cysteine proteinases, such as cathepsin B, hydrolyzed the specific substrate for papain during titration with the papain. In order to exclude this interference and measure total cystatin activity, the crude sample must be alkalinized (pH 11.0) for 5 min at 4°C followed by 10 min at 40°C before titration with papain. The minimum detectable amount of cystatins was 20 fmol/ assay when it was calculated per mole of papain inhibitory sites. Using this method, significant levels of cystatin activity were detected in all the samples of gingival crevicular fluid taken from periodontal disease patients. These results suggest that cystatins could regulate the cysteine proteinases in gingival crevicular fluid and that this new method could be useful to clarify the role of cystatins in the pathogenesis of periodontal disease.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1600-0765
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Different types of periodontopathic bacterial lipopolysaccharide (LPS) exert various biological activities in vitro. However, whether or not these activities also occur in vivo remains unclear. Thus the present study investigates bone resorption, as well as local IL-1α and IL-1β synthesis induced by Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis LPS in the periodontal tissue of mice. Both types of LPS were injected into mouse gingiva every 48 h and the animals were sacrificed 6 h after the 1st, 4th, 7th, 10th, 13th, 16th, 20th, or 24th injection. Bone resorption in the injected gingiva was histopathologically and histomorphometrically investigated and local concentrations of IL-1α and IL-1β were detected using an enzyme-linked immunosorbent assay. The active resorption ratio was significantly higher in the group given the 10th injection of LPS from A. actinomycetemcomitans than in the group given P. gingivalis LPS. Furthermore, A. actinomycetemcomitans LPS stimulated significantly more synthesis of IL-1α than P. gingivalis LPS after the 4th and 10th injections, and of IL-1β after the 4th, 7th, 10th, 13th, 16th and 20th injections. These results suggest that A. actinomycetemcomitans LPS is a more potent inducer of bone resorption and synthesis of IL-1α and IL-1β in the short term than P. gingivalis LPS.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1600-0765
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: To clarify roles of lysosomal cysteine proteinases cathepsins B, H and L in pathological destructive process of periodontal tissues, levels of their enzymatic activities were determined in gingival crevicular fluid (GCF) from chronic adult periodontitis patients and from experimental gingivitis subjects. In periodontitis patients, higher levels of cathepsins B, H and L activities were found at sites with more serious signs of the disease activity. The total activity of each enzyme (per unit time) was positively correlated with the GCF volume. However, it had little or no correlation with the probing depth (PD). In contrast, the specific activity of each enzyme in GCF (activity units per mg protein), which reflects the selectivity of enzyme exudation, was negatively correlated with the GCF volume. These results suggest that the cysteine proteinases are selectively released into gingival crevices at a relatively mild stage of periodontitis. In experimental gingivitis subjects, no significant activity of each enzyme was detected in GCF, even when the quantity of GCF was comparable to that from periodontitis patients. These data suggest that no significant amounts of these enzymes are released at experimental gingivitis sites or that a homeostatic mechanism, including regulation by protease inhibitors, may control activities of these enzymes in GCF with acute inflammation.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of periodontal research 34 (1999), S. 0 
    ISSN: 1600-0765
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: We examined the levels of anti-thymocyte/T lymphocyte autoantibody (ATA) in the serum of mice injected intraperitoneally with lipopolysaccharides (LPS) from periodontopathic bacteria; Porphyromonas gingivalis, Actinobacillus actinomyceterncomitans, Fusobacterium nucleatum, Capnocytophaga ochracea, and non-oral Escherichia coli. All of the LPS induced IgM-ATA. Among these, LPS from C. ochracea induced the highest level of IgM-ATA, whereas that of P. gingivalis induced the lowest. The peritoneal T lymphocytes of mice injected with LPS were bound by IgM-ATA. Peritoneal B-1 (CD5+B) cells stimulated by each LPS produced much more IgM-ATA than splenic B-2 (CD5− B) cells, suggesting that B-1 cells might be responsible for the production of these antibodies. Serum of mice injected with C. ochracea and F. nucleatum LPS showed cytotoxicity against thymocytes in the presence of rabbit complements. Binding and cytotoxicity were confirmed by IgM purified from serum of the mice injected with C. ochracea LPS. Furthermore, serum of mice treated with C. ochracea, F. nucleatum or A. actinomycetemcomitans LPS inhibited the proliferation of thymocytes. However, purified IgM from the serum of mice treated with C. ochracea LPS failed to produce the same inhibition. Our results suggest that LPS from certain species of periodontopathic bacteria can induce IgM-ATA in the serum and these antibodies may modulate the local immune network in periodontal tissues.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  To examine the role of T cell subgroups, Th1 and Th2, in the development of periodontitis, the expression of various cytokines was investigated in a mouse model of alveolar bone resorption using in situ hybridization (ISH) with digoxigenin-labeled oligonucleotides. When mice received repetitive injections with Escherichia coli lipopolysaccharide into the gingiva every 48 h, alveolar bone resorption was detectable after the fourth injection, reaching a maximum after the 13th injection. For the best performance of ISH, we first had to choose a decalcification protocol. Among various decalcification protocols, 10% EDTA (4°C, 5–6 days) was the best for 28S rRNA staining. Positive cells for transcripts of interferon-γ (Th1 product) were detected after the fourth injection, reaching a maximum after the tenth injection. A similar pattern was obtained for interleukin (IL)-10 mRNA (Th2 product) and IL-1β, while the positive cell number reached a maximum after the 13th and 10th injections, respectively. The number of IL-4 mRNA (Th2 product)-positive cells remained low till the tenth injection, but increased thereafter. Consequently, we found that the population change from Th1 to Th2 in the inflammation site correlated with the transition from gingivitis to periodontitis, indicating differential roles of T cell subgroups in the development of periodontitis.
    Type of Medium: Electronic Resource
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