Damage-regulated autophagy modulator 1 in oral inflammation and infection.

OBJECTIVES: Damage-regulated autophagy modulator (DRAM) 1 is a p53 target gene with possible involvement in oral inflammation and infection. This study sought to examine the presence and regulation of DRAM1 in periodontal diseases. MATERIAL AND METHODS: In vitro, human periodontal ligament fibroblasts were exposed to interleukin (IL)-1ß and Fusobacterium nucleatum for up to 2 days. The DRAM1 synthesis and its regulation were analyzed by real-time PCR, immunocytochemistry, and ELISA. Expressions of other autophagy-associated genes were also studied by real-time PCR. In vivo, synthesis of DRAM1 in gingival biopsies from rats and patients with and without periodontal disease was examined by real-time PCR and immunohistochemistry. For statistics, ANOVA and post-hoc tests were applied (p < 0.05). RESULTS: In vitro, DRAM1 was significantly upregulated by IL-1ß and F. nucleatum over 2 days and a wide range of concentrations. Additionally, increased DRAM1 protein levels in response to both stimulants were observed. Autophagy-associated genes ATG3, BAK1, HDAC6, and IRGM were also upregulated under inflammatory or infectious conditions. In vivo, the DRAM1 gene expression was significantly enhanced in rat gingival biopsies with induced periodontitis as compared to control. Significantly increased DRAM1 levels were also detected in human gingival biopsies from sites of periodontitis as compared to healthy sites. CONCLUSION: Our data provide novel evidence that DRAM1 is increased under inflammatory and infectious conditions in periodontal cells and tissues, suggesting a pivotal role of DRAM1 in oral inflammation and infection. CLINICAL RELEVANCE: DRAM1 might be a promising target in future diagnostic and treatment strategies for periodontitis.

Salivary, gingival crevicular fluid and serum levels of ghrelin and chemerin in patients with periodontitis and overweight.

BACKGROUND AND OBJECTIVE: Nutrition and body weight are modifying factors for periodontitis. The purpose of this study was to quantify two molecules (ghrelin and chemerin), released in association with food intake and obesity, in periodontally healthy and diseased individuals with respect to different body mass categories. MATERIAL AND METHODS: The two main groups (patients with chronic periodontitis and periodontally healthy/gingivitis volunteers) were subdivided into groups of subjects with normal weight [body mass index (BMI) <25] and groups of overweight/obese subjects (BMI ≥25). Subgingival bacteria were analysed and the levels of acylated and total ghrelin, chemerin and interleukin-1ß (IL-1ß) were assessed in saliva, gingival crevicular fluid and serum. RESULTS: The amount of Treponema denticola present subgingivally was significantly higher in the groups of patients with chronic periodontitis as well as in periodontally healthy/gingivitis individuals with BMI ≥25 than in periodontally healthy/gingivitis individuals with BMI <25. The amount of total ghrelin in gingival crevicular fluid differed significantly between the groups, with the lowest levels found in the group of patients with chronic periodontitis and BMI ≥25. The levels of chemerin in gingival crevicular fluid were significantly higher in each chronic periodontitis group than in periodontally healthy/gingivitis individuals with BMI <25. However, the level of IL-1ß in the gingival crevicular fluid was most differentiating between the groups, with the highest levels found in the group of patients with chronic periodontitis and BMI <25 and the lowest levels in periodontally healthy/gingivitis individuals with BMI <25. No significant differences between any groups were seen for chemerin or for acylated ghrelin in the stimulated whole saliva, or for acylated and total ghrelin in peripheral blood serum. The BMI correlated with the serum level of chemerin. CONCLUSION: Low ghrelin and high chemerin levels in the gingival crevicular fluid might be linked to periodontal disease and overweight/obesity. However, unlike IL-1ß, the levels of chemerin and ghrelin in gingival crevicular fluid are not reliable indicators of periodontal destruction.

Role of Cathepsin S in Periodontal Inflammation and Infection.

Cathepsin S is a cysteine protease and regulator of autophagy with possible involvement in periodontitis. The objective of this study was to investigate whether cathepsin S is involved in the pathogenesis of periodontal diseases. Human periodontal fibroblasts were cultured under inflammatory and infectious conditions elicited by interleukin-1ß and Fusobacterium nucleatum, respectively. An array-based approach was used to analyze differential expression of autophagy-associated genes. Cathepsin S was upregulated most strongly and thus further studied in vitro at gene and protein levels. In vivo, gingival tissue biopsies from rats with ligature-induced periodontitis and from periodontitis patients were also analyzed at transcriptional and protein levels. Multiple gene expression changes due to interleukin-1ß and F. nucleatum were observed in vitro. Both stimulants caused a significant cathepsin S upregulation. A significantly elevated cathepsin S expression in gingival biopsies from rats with experimental periodontitis was found in vivo, as compared to that from control. Gingival biopsies from periodontitis patients showed a significantly higher cathepsin S expression than those from healthy gingiva. Our findings provide original evidence that cathepsin S is increased in periodontal cells and tissues under inflammatory and infectious conditions, suggesting a critical role of this autophagy-associated molecule in the pathogenesis of periodontitis.

Dental caries and microbiota in children with black stain and non-discoloured dental plaque.

AIM: We aimed to assess caries experience and microbiota in systemically healthy children with black stain (BS) and non-discoloured plaque. METHODS: Forty-six children with BS and 47 counterparts with non-discoloured plaque aged 7.9 ± 1.3 years were clinically examined. Dental caries was scored using WHO criteria. Samples of BS and non-discoloured dental plaque were collected from tooth surfaces. The DNA of the samples was extracted and real-time PCR was performed to determine the total number of bacteria and the species Streptococcus mutans, S. sobrinus, Lactobacillus sp., Actinomyces naeslundii, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum. RESULTS: Children with BS had lower DMFT (p = 0.013), lower DT values (p = 0.005) and a tendency to lower caries prevalence (p = 0.061) than children with non-discoloured plaque. Plaque samples of the BS group contained higher numbers of A. naeslundii (p = 0.005) and lower numbers of F. nucleatum (p = 0.001) and Lactobacillus sp. (p = 0.001) compared to the non-discoloured plaque samples of the control group. Comparing the children with BS and non-discoloured plaque, higher counts for A. naeslundii (p = 0.013) were observed in caries-free children with BS while in caries-affected children with BS, lower counts of F. nucleatum (p = 0.007) were found. Counts of Lactobacillus sp. were higher in non-discoloured plaque samples than in BS of caries-free and caries-affected children. CONCLUSION: Results suggest that the different microbial composition of BS might be associated with the lower caries experience in affected subjects. The role of black-pigmented bacteria associated with periodontitis needs further studies.

Oral prophylaxis and its effects on halitosis-associated and inflammatory parameters in patients with chronic periodontitis.

OBJECTIVE: A controlled clinical trial was conducted to evaluate the effects of oral prophylaxis on halitosis-associated, immunological and microbiological parameters. METHODS: Thirty subjects were included in this controlled clinical trial (patients with generalized chronic periodontitis and controls without clinical attachment loss; each n = 15). Before oral prophylaxis and 14 days after (including tongue cleaning) volatile sulphur compounds (VSC), organoleptic scores and a tongue coating index were evaluated. The levels of IL-1ß, IL-8, IL-10 and MMP-8 were measured in GCF, and also major periodontal pathogens were detected. Data were statistically analysed using anova and paired t-test. RESULTS: Supragingival plaque and calculus removal with combined tongue cleaning was able to reduce significantly (P < 0.05) the VSC values in both groups (no significant differences between both groups). Two weeks after periodontal debridement, the VSC values were observed in the periodontitis group, but not in the control group, similar to the baseline values. The difference between the groups was statistically significant (P < 0.05). Only a repeated prophylaxis session in the periodontitis group was able to reduce VSC values significantly in comparison with baseline (P < 0.05). Organoleptic scores (10 and 30 cm) were significantly different (P < 0.05) between both groups before and after the treatment. Periodontal pathogens and host-derived markers were not significantly affected by a single prophylaxis session. CONCLUSIONS: Oral prophylaxis may result in a significant decrease in VSC values. However, in periodontal diseases, a more complex treatment seems to be necessary.

Cleavage of IgG1 in gingival crevicular fluid is associated with the presence of Porphyromonas gingivalis.

BACKGROUND AND OBJECTIVES: Immunoglobulin (Ig) G1 plays an important role in the adaptive immune response. Kgp, a lysine-specific cysteine protease from Porphyromonas gingivalis, specifically hydrolyses IgG1 heavy chains. The purpose of this study was to examine whether cleavage of IgG1 occurs in gingival crevicular fluid (GCF) in vivo, and whether there is any association with the presence of Porphyromonas gingivalis and other periodontopathogens. MATERIAL AND METHODS: GCF was obtained from nine patients with aggressive periodontitis, nine with chronic periodontitis and five periodontally healthy individuals. The bacterial loads of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Treponema denticola, Prevotella intermedia and Tannerella forsythia were analysed by real-time polymerase chain reaction, and the presence and cleavage of IgG1 and IgG2 were determined using Western blotting. Kgp levels were measured by ELISA. RESULTS: Cleaved IgG1 was identified in the GCF from 67% of patients with aggressive periodontitis and in 44% of patients with chronic periodontitis. By contrast, no cleaved IgG1 was detectable in healthy controls. No degradation of IgG2 was detected in any of the samples, regardless of health status. Porphyromonas gingivalis was found in high numbers in all samples in which cleavage of IgG1 was detected (P < 0.001 compared with samples with no IgG cleavage). Furthermore, high numbers of Tannerella forsythia and Prevotella intermedia were also present in these samples. The level of Kgp in the GCF correlated with the load of Porphyromonas gingivalis (r = 0.425, P < 0.01). The presence of Kgp (range 0.07-10.98 ng/mL) was associated with proteolytic fragments of IgG1 (P < 0.001). However, cleaved IgG1 was also detected in samples with no detectable Kgp. CONCLUSION: In patients with periodontitis, cleavage of IgG1 occurs in vivo and may suppress antibody-dependent antibacterial activity in subgingival biofilms especially those colonized by Porphyromonas gingivalis.

Influence of serum on interaction of Porphyromonas gingivalis ATCC 33277 and Aggregatibacter actinomycetemcomitans Y4 with an epithelial cell line.

BACKGROUND AND OBJECTIVE: The purpose of this study was to investigate the influence of serum on the interaction of periodontal pathogens with epithelial cells using an epithelial cell line (KB cells). This is important because serum is a key component of gingival crevicular fluid and may influence inflammatory responses in epithelial cells exposed to periodontal pathogens. MATERIAL AND METHODS: Porphyromonas gingivalis ATCC 33277 and Aggregatibacter actinomycetemcomitans Y4 were co-cultured with KB cells either with or without the addition of up to 10% human serum or 50 mg/mL human serum albumin. The numbers of free-floating, adherent and intracellular bacteria were determined up to 18 h after exposure of the epithelial cells to the pathogens. Additionally, the concentrations of interleukin (IL)-6 and IL-8 produced by the epithelial cells in response to exposure to the bacteria were determined. RESULTS: Serum and human serum albumin reduced the number of internalized A. actinomycetemcomitans Y4 organisms in the epithelial cells, increased the levels of IL-6 and IL-8 in the supernatants of infected cells (those with internalized A. actinomycetemcomitans) and influenced non-infected epithelial cells. Increased IL-6 and IL-8 concentrations were also detected in the supernatants of KB cells infected with P. gingivalis ATCC 33277. Interleukin-6 and IL-8 were detectable after addition of serum, probably as a result of inhibition of the activity of P. gingivalis cysteine proteinases by serum. CONCLUSION: Serum promotes the release of the cytokines IL-6 and IL-8 by epithelial cells. This mechanism is influenced by periodontal pathogens and may maintain clinical periodontal inflammation.

Microbiological and host-derived biomarker evaluation following non-surgical periodontal therapy with short-term administration of systemic antimicrobials: secondary outcomes of an RCT.

Nonsurgical periodontal therapy with adjunctive use of systemic antimicrobials (for 7-14 days) showed improved clinical, microbiological and immunological results over the mechanical protocol alone. Considering the increasing risk for antimicrobial resistance with longer antibiotic regimes, it is important to establish the optimal antibiotic protocol with a maximum antimicrobial benefit and minimum risk for adverse effects. The aim of the study was to evaluate the microbiological and inflammatory outcomes 12-months after a 3-/7-day systemic antibiotic protocol [amoxicillin (AMX) + metronidazole (MET)] adjunctive to subgingival debridement in severe periodontitis compared to mechanical treatment alone. From the initially treated 102 patients, 75 subjects (Placebo group: n = 26; 3-day AMX + MET group: n = 24; 7-day AMX + MET group: n = 25) completed the 12-month examination. Clinical parameters, eight periodontal pathogens and inflammatory markers were determined at baseline and 3-, 6-, 12-months after therapy using real-time PCR and ELISA respectively. After 6 months, several periodontopathogens were significantly more reduced in the two antibiotic groups compared to placebo (p < 0.05). After 1 year, both antibiotic protocols showed significant reductions and detection of the keystone pathogen P. gingivalis compared to placebo. Antibiotic protocols, smoking, disease severity, baseline-BOP, -CAL and -IL-1ß, as well as detection of T. denticola at 12-months significantly influenced the residual number of deep sites. The present data indicate that the systemic use of both short and longer antibiotic protocols (AMX + MET) adjunctive to nonsurgical periodontal therapy lead to higher microbiological improvements compared to subgingival debridement alone. The two investigated antibiotic protocols led to comparable microbiological and inflammatory results.

Neutrophils in chronic and aggressive periodontitis in interaction with Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans.

BACKGROUND AND OBJECTIVE: This study analyzed the interaction of Porphyromonas gingivalis ATCC 33277 and Aggregatibacter actinomycetemcomitans Y4 with peripheral blood polymorphonuclear neutrophils taken from patients with aggressive periodontitis and chronic periodontitis. MATERIAL AND METHODS: Peripheral blood polymorphonuclear neutrophils obtained from 12 patients with chronic periodontitis, six patients with aggressive periodontitis and 12 healthy controls were exposed to P. gingivalis and A. actinomycetemcomitans following opsonization of the bacteria using the patient's own serum. Serum immunoglobulin G (IgG) levels against both periodontopathogens were measured. Phagocytosis and killing of the bacteria, as well as the extracellular human neutrophil elastase activity, were quantified. The total amount and the extracellular release of reactive oxygen species were measured using luminol-dependent and isoluminol-dependent chemiluminescence. RESULTS: Polymorphonuclear neutrophils from patients with chronic (62.16 +/- 19.39%) and aggressive (43.26 +/- 26.63%) periodontitis phagocytosed more P. gingivalis than the healthy controls (24.43 +/- 19.87%) at the 30-min time point after exposure to the bacteria (p < 0.05). High serum IgG levels against P. gingivalis and A. actinomycetemcomitans were detected in subjects with periodontitis. Polymorphonuclear neutrophils from subjects with chronic and aggressive periodontitis released significantly more reactive oxygen species and demonstrated greater human neutrophil elastase activity in the absence of any stimulus than polymorphonuclear neutrophils from healthy controls (p < 0.05). Polymorphonuclear neutrophils in chronic periodontitis released significantly more reactive oxygen species when exposed to P. gingivalis and A. actinomycetemcomitans than polymorphonuclear neutrophils in aggressive periodontitis. CONCLUSION: High serum IgG levels against P. gingivalis and A. actinomycetemcomitans promote phagocytosis in periodontitis. The extracellular release of reactive oxygen species and neutrophil elastase by polymorphonuclear neutrophils may also contribute to damage of the surrounding periodontal tissues.

Analysis of neutrophil-derived antimicrobial peptides in gingival crevicular fluid suggests importance of cathelicidin LL-37 in the innate immune response against periodontogenic bacteria.

INTRODUCTION: During periodontitis, an innate immune response to bacterial challenge is primarily mediated by neutrophils. We compared neutrophilic content and the level of neutrophil-derived antimicrobial peptides in gingival crevicular fluid (GCF) in two clinical forms of severe periodontitis. METHODS: GCF was collected from 14 patients with aggressive periodontitis, 17 patients with chronic periodontitis, and nine healthy subjects. Samples were analyzed for periodontopathogen load using real-time polymerase chain reactions. The amounts of myeloperoxidase and alpha-defensins (HNP1-3) were determined by enzyme-linked immunosorbent assay, and the level of cathelicidin (hCAP18/LL-37) was assayed by Western blot. RESULTS: Myeloperoxidase concentration was not correlated with levels of LL-37 and HNP1-3 in samples from patients, compared to controls. The amount of HNP1-3 was twofold and fourfold higher in patients with aggressive and chronic periodontitis, respectively. Those with chronic disease had significantly elevated amounts of mature LL-37. The increased concentration of both peptides in chronic periodontitis correlated with the load of Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola. CONCLUSION: The lack of a correlation between LL-37, HNP1-3, and myeloperoxidase content suggests that neutrophils are not the sole source of these bactericidal peptides in the GCF of patients with periodontitis; and that other cells contribute to their local production. The bacterial proteases of P. gingivalis, T. forsythia, and T. denticola might degrade hCAP18/LL-37, because the 11-kDa cathelicidin-derived fragment was present in GCF collected from pockets infected with these bacteria. Collectively, it appears that a local deficiency in LL-37 can be considered as a supporting factor in the pathogenesis of severe cases of periodontitis.

In vivo expression of proteases and protease inhibitor, a serpin, by periodontal pathogens at teeth and implants.

Porphyromonas gingivalis and Tannerella forsythia secrete proteases, gingipains and KLIKK-proteases. In addition, T. forsythia produces a serpin (miropin) with broad inhibitory spectrum. The aim of this pilot study was to determine the level of expression of miropin and individual proteases in vivo in periodontal and peri-implant health and disease conditions. Biofilm and gingival crevicular fluid (GCF)/ peri-implant sulcular fluid (PISF) samples were taken from healthy tooth and implant sites (n = 10), gingivitis and mucositis sites (n = 12), and periodontitis and peri-implantitis sites (n = 10). Concentration of interleukin-8 (IL-8), IL-1ß and IL-10 in GCF was determined by enzyme-linked immunosorbent assay. Loads of P. gingivalis and T. forsythia and the presence of proteases and miropin genes were assessed in biofilm by quantitative PCR, whereas gene expression was estimated by quantitative RT-PCR. The presence of P. gingivalis and T. forsythia, as well as the level of IL-8 and IL-1ß, were associated with disease severity in the periodontal and peri-implant tissues. In biofilm samples harboring T. forsythia, genes encoding proteases were found to be present at 72.4% for karilysin and 100% for other KLIKK-protease genes and miropin. At the same time, detectable mRNA expression of individual genes ranged from 20.7% to 58.6% of samples (for forsylisin and miropsin-1, respectively). In comparison with the T. forsythia proteases, miropin and the gingipains were highly expressed. The level of expression of gingipains was associated with those of miropin and certain T. forsythia proteases around teeth but not implants. Cumulatively, KLIKK-proteases and especially miropin, might play a role in pathogenesis of both periodontal and peri-implant diseases.

Frequency and structure of t(14;18) major breakpoint regions in non-Hodgkin's lymphomas typed according to the Kiel classification: analysis by direct DNA sequencing.

We have examined 165 unselected cases of non-Hodgkin's lymphomas for rearrangements involving the t(14;18) major breakpoint region using a polymerase chain reaction (PCR) and direct sequencing of amplified major breakpoint region bcl-2/JH junctional regions. The lymphomas, diagnosed according to the updated Kiel classification, consisted of 33 centroblastic-centrocytic, 37 centroblastic, 27 immunocytic, 10 immunoblastic, 10 centrocytic, 2 lymphoblastic, 2 Ki-1-positive anaplastic large cell, 14 peripheral T-cell, and 4 unclassified lymphomas. In addition 18 chronic lymphocytic leukemias, 2 hairy cell leukemias, and 6 plasmacytomas were studied. In 17 cases a bcl-2/JH gene fusion sequence was amplified by PCR. A bcl-2/JH gene fusion was detected only in three lymphoma subgroups: 13 of 33 centroblastic-centrocytic (39%), 2 of 37 centroblastic (6%), and 2 of 27 immunocytic (8%) were positive. In two cases, major breakpoint region bcl-2 rearrangements verified by genomic Southern analysis were not detected by PCR. Direct sequencing of all 17 PCR-amplified, previously uncharacterized t(14;18) junctional regions provided corroborating evidence for the specificity of the assay. The procedure gave sequencing results even from limited amounts of lymphoma cells as obtained by fine needle aspiration of lymph nodes or from clinically uninvolved sites. Clone-specific sequences were identified due to the involvement of different JH segments, the variations among the exact JH and bcl-2 breakpoint positions, and the extensive incorporation of junctional region (D-) N-nucleotides. These clone-specific sequences allow accurate identification of clinically occult lymphoma cells and reduce the threat of false positive results. The finding of exceptionally long intervening sequences in some of the junctions and the partial homology with published DH segments in three cases support the view that some of the putative N-regions harbor DH regions.

Human H1 histones: conserved and varied sequence elements in two H1 subtype genes.

The genes coding for two different human H1 histones were isolated, and the primary structures were deduced from the nucleotide sequences. The genes differ from each other and from any other vertebrate H1 structure described until now. The differences occur mainly within the N- and C-terminal H1 domains, whereas the central part of the protein is highly conserved. Within the flanking domains, however, some sequence elements are shared by different H1 subtype genes. An octapeptide, which has been described in C-terminal domains of most H1 histones, is found in both H1 subtypes. The nucleotide sequences of the flanking portions of both H1 genes show conserved motifs at established regulatory sites, but otherwise these 3' and 5' noncoding sequences of both genes differ substantially.

Polymerase Chain Reaction Analysis of t(14;18) Junctional Regions in B-Cell Lymphomas.

The polymerase chain reaction (PCR) procedure was used for rapid and highly specific amplification of the t(14;18) bcl-2/JH DNA junctional regions in B-cell lymphomas. By using Taq-polymerase and relatively long oligonucleotide primers-a 33-mer for bcl-2 and an universal 25-mer complementary to the JH consensus sequence-the primer annealing and primer extension steps could be carried out at the same temperature (70°C), thus markedly reducing the reaction time and significantly improving the specificity of the reaction. The specificity of the amplification allowed visual identification of the bcl-2/JH PCR-products in ethidium bromide stained agarose gels. DNA-sequence analysis of PCR-amplified, previously uncharacterized t(14; 18) junctional regions, confirmed the specificity of this assay. Moreover, preliminary data show that the procedure is capable of documenting the presence of occult lymphoma cells in both the peripheral blood and bone marrow.

Antimicrobial susceptibility of anaerobic and capnophilic bacteria isolated from odontogenic abscesses and rapidly progressive periodontitis.

In dentistry antimicrobials are used in the treatment of progressive periodontitis and odontogenic abscesses, therefore the susceptibility to commonly used antibiotics of capnophilic and anaerobic species causing these diseases should be investigated. The activity of penicillin, amoxycillin, cefoxitin, clindamycin, doxycycline, metronidazole and ciprofloxacin was investigated. One hundred and sixty four isolates from subgingival plaque samples of 66 patients with progressive periodontitis and 192 bacterial strains from pus of 74 patients with odontogenic abscesses were included in this study. The majority of species tested were gram-negative anaerobes (Prevotella spp., Porphyromonas spp., Fusobacterium spp.), and were highly susceptible to clindamycin and metronidazole. Nearly 6% of the periodontal isolates and 22% of the bacteria obtained from pus samples produced beta-lactamases. With the exception of the periodontopathogenic species Actinobacillus actinomycetemcomitans and Eikenella corrodens, clindamycin seemed to be a useful antibiotic and could be recommended for empirical antimicrobial treatment.

Influence of hormonal contraceptives on microbial flora of gingival sulcus.

To determine a possible influence of two different hormonal contraceptives on bacterial microflora of gingival sulcus, subgingival plaque samples of 29 healthy women aged between 20 and 32 years were investigated bacteriologically before subjects took a contraceptive and 10 and 20 days after subjects started the medication. In 14 women, and oral contraceptive containing 0.02 mg ethinyl estradiol and 0.15 mg desogestrel (preparation A) was used, and 15 women took a contraceptive containing 0.03 mg ethinyl estradiol and 2.00 mg dienogest (preparation B) daily over 21 days. There were no changes in clinical parameters of the teeth investigated during 3 weeks of the study. The periodontopathogenic bacteria Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans were never detected throughout the study. On the other hand, the periodontopathogenic species Prevotella intermedia was found in plaque samples of 22 women. The content of this microorganism showed only a little change between the pretreatment period and plaque sampling after 10 days of contraceptive treatment, but a striking increase occurred after 20 days of contraceptive treatment, especially in the preparation A group. In this respect, there was a significant difference between preparations A and B.

PIP: Several studies have suggested an association between sex hormones and chronic inflammatory periodontal disease. This study investigated the impact of two oral contraceptives (OCs) on bacterial microflora of gingival sulcus samples obtained from 29 women 20-32 years of age recruited from Jena (Germany) University Women's Hospital. Study participants were randomly assigned to receive an OC containing either 0.02 mg of ethinyl estradiol and 0.15 mg of desogestrel (n = 14) or 0.03 mg of ethinyl estradiol and 2.00 mg of dienogest (n = 15). Subgingival plaque samples were obtained before and 10 and 20 days after the initiation of OC use. No changes in clinical parameters of the upper incisors (i.e., bleeding on probing, pocket depth, plaque) occurred in either study group during 21 days of OC use. Although Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans were not detected, 22 plaque samples showed evidence of the periodontopathogenic bacteria Prevotella intermedia. The mean cultivable content of this microorganism increased significantly in users of the OC containing desogestrel from 1.2% at day 10 of OC use to 10.0% at day 20, but decreased slightly in women assigned to the OC containing dienogest and a higher dose of ethinyl estradiol. Good oral hygiene is essential in pregnancy and during OC use to compensate for hormonal influences and prevent gingivitis.

Metabolic products of microorganisms. 249. Tetracenomycins B3 and D3, key intermediates of the elloramycin and tetracenomycin C biosynthesis.

Tetracenomycins B3 and D3, besides tetracenomycin D (D1), were produced by a blocked mutant of the elloramycin producer Streptomyces olivaceus TU 2353. The compounds were isolated as red powders, and their structures were elucidated by comparing their physicochemical data with those of the known tetracenomycins A2, B1, B2, D and E. Tetracenomycin B3 (2), the main compound, and tetracenomycin D (3) were antibiotically inactive against Gram-positive and Gram-negative bacteria, whereas tetracenomycin D3 (1) showed a moderate activity against Bacillus subtilis and Arthrobacter aurescens. Tetracenomycin B3 (2) is the key intermediate where the biosynthesis of the elloramycins branches off from the line leading to tetracenomycin C (5) as the final product of the tetracenomycin biosynthesis branch.

Reduction of fine airborne particulates (PM3) in a small city centre office, by altering electrostatic forces.

A two stage intervention study was carried out to establish the degree to which a newly developed, electrostatic air cleaning (EAC) system can improve indoor air quality (IAQ) by reducing the number of airborne fine particles. The IAQ and how employees in a city centre office (49 m2) perceived it, was monitored from May until November 1998. The number of fine particles, PM3 (0.3-3.0 microm); number of coarse particles, PM7 (3.0-7.0 microm); number of small positive and negative air ions; relative humidity and temperature were recorded in and out of doors. To assess the employees' perception of any changes in their work environment, a questionnaire was completed. Number of particles, relative humidity and temperature were also recorded in a nearby office, equipped with an identical air processor, where no interventions were made. The results from the first intervention (Stage 1), comparing number of airborne particles outdoors to indoors, gave a 19% reduction for PM3 and a 67% reduction for PM7 (P < 0.001). The reduction in PM3 was inconsistent and not statistically significant (P = 0.3). The reduction in PM7 from outdoors and the removal of PM7 created indoors was achieved by optimizing the existing air moving equipment. The results from the second intervention (Stage 2--with EAC units installed) comparing indoor to outdoor values, gave a further reduction in PM3 of 21% (P < 0.001) and a further 3% reduction for PM7 (P > 0.05). Therefore, at the end of Stage 2, the total reductions in particles from outdoors to indoors were 40% for PM3 and 70% for PM7 (P < 0.001). The Stage 2 results strongly suggest that electrostatic forces, created by the EAC unit(s) improved the removal of PM3, with no further significant improvement in the reduction of PM7. The questionnaire indicated an improvement in the IAQ, as perceived by the employees. The results suggest that the EAC system is effective in reducing PM3 and thereby improving IAQ in an urban office.

The role of adipokines in periodontal infection and healing.

Periodontitis is a chronic inflammatory disease of the periodontium, which is caused by pathogenic bacteria in combination with other risk factors. The bacteria induce an immunoinflammatory host response, which can lead to irreversible matrix degradation and bone resorption. Periodontitis can be successfully treated. To achieve regenerative periodontal healing, bioactive molecules, such as enamel matrix derivative (EMD), are applied during periodontal surgery. Recently, it has been shown that obesity is associated with periodontitis and compromised healing after periodontal therapy. The mechanisms underlying these associations are not well understood so far, but adipokines may be a pathomechanistic link. Adipokines are bioactive molecules that are secreted by the adipose tissue, and that regulate insulin sensitivity and energy expenditure, but also inflammatory and healing processes. It has also been demonstrated that visfatin and leptin increase the synthesis of proinflammatory and proteolytic molecules, whereas adiponectin downregulates the production of such mediators in periodontal cells. In addition, visfatin and leptin counteract the beneficial effects of EMD, whereas adiponectin enhances the actions of EMD on periodontal cells. Since visfatin and leptin levels are increased and adiponectin levels are reduced in obesity, these adipokines could be a pathomechanistic link whereby obesity and obesity-related diseases enhance the risk for periodontitis and compromised periodontal healing. Recent studies have also revealed that adipokines, such as visfatin, leptin and adiponectin, are produced in periodontal cells and regulated by periodontopathogenic bacteria. Therefore, adipokines may also represent a mechanism whereby periodontal infections can impact on systemic diseases.

Benzamidine derivatives inhibit the virulence of Porphyromonas gingivalis.

We have previously shown that benzamidine-type compounds can inhibit the activity of arginine-specific cysteine proteinases (gingipains HRgpA and RgpB); well-known virulence factors of Porphyromonas gingivalis. They also hinder in vitro growth of this important periodontopathogenic bacterium. Apparently growth arrest is not associated with their ability to inhibit these proteases, because pentamidine, which is a 20-fold less efficient inhibitor of gingipain than 2,6-bis-(4-amidinobenzyl)-cyclohexanone (ACH), blocked P. gingivalis growth far more effectively. To identify targets for benzamidine-derived compounds other than Arg-gingipains, and to explain their bacteriostatic effects, P. gingivalis ATCC 33277 and P. gingivalis M5-1-2 (clinical isolate) cell extracts were subjected to affinity chromatography using a benzamidine-Sepharose column to identify proteins interacting with benzamidine. In addition to HRgpA and RgpB the analysis revealed heat-shock protein GroEL as another ligand for benzamidine. To better understand the effect of benzamidine-derived compounds on P. gingivalis, bacteria were exposed to benzamidine, pentamidine, ACH and heat, and the expression of gingipains and GroEL was determined. Exposure to heat and benzamidine-derived compounds caused significant increases in GroEL, at both the mRNA and protein levels. Interestingly, despite the fact that gingipains were shown to be the main virulence factors in a fertilized egg model of infection, mortality rates were strongly reduced, not only by ACH, but also by pentamidine, a relatively weak gingipain inhibitor. This effect may depend not only on gingipain inhibition but also on interaction of benzamidine derivatives with GroEL. Therefore these compounds may find use in supportive periodontitis treatment.