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 m
2) perceived it, was monitored from May until November 1998. The number of fine particles, PM
3 (0.3–3.0 μm); number of coarse particles, PM
7 (3.0–7.0 μm); 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 PM
3 and a 67% reduction for PM
7 (
P<0.001). The reduction in PM
3 was inconsistent and not statistically significant (
P=0.3). The reduction in PM
7 from outdoors and the removal of PM
7 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 PM
3 of 21% (
P<0.001) and a further 3% reduction for PM
7 (
P>0.05). Therefore, at the end of Stage 2, the total reductions in particles from outdoors to indoors were 40% for PM
3 and 70% for PM
7 (
P<0.001). The Stage 2 results strongly suggest that electrostatic forces, created by the EAC unit(s) improved the removal of PM
3, with no further significant improvement in the reduction of PM
7. The questionnaire indicated an improvement in the IAQ, as perceived by the employees. The results suggest that the EAC system is effective in reducing PM
3 and thereby improving IAQ in an urban office.
Background, aims: Polymorphonuclear neutrophils (PMN) are the predominant host defence cells in the gingival sulcus. Previous work demonstrates that the in vitro phagocytosis of crevicular cells in ...localised early onset periodontitis (LEOP) and generalised early onset periodontitis (GEOP) lesions is diminished. The present study extends this work by characterizing the chemotaxis function of crevicular fluid (CF) PMNs in various forms of periodontitis.
Methods: We investigated 7 patients with LEOP, 11 patients with GEOP, 12 patients with adult periodontitis (AP) and 2 age‐ and sex‐matched healthy control groups. The two deepest sites of each quadrant in test and control subjects were selected for crevicular sampling. Chemotaxis was performed in a micro chamber (moist atmosphere, 5% CO2, 37 °C, 30 min) using N‐formyl‐methionyl‐leucyl‐phenylalanine (FMLP, 1×10−7 mol FMLP/l) as a chemoattractant. The total chemotaxis was defined as the difference between the number of cells migrating towards FMLP minus the number of cells migrating towards PBS, counted in 20 randomly selected fields. Membranes were examined microscopically at 400× magnification.
Results: The chemotactic activity in the adult periodontitis group was significantly higher compared to the age‐related control group. However, we found a statistically significant reduction of chemotactic activity in LEOP and GEOP patients compared to the controls.
Conclusions: These results indicate an increase of chemotactic activity from CF‐PMN in patients with adult periodontitis, but on the other hand, a significant reduction of chemotactic responsiveness of these cells in LEOP and GEOP lesions.
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 α‐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.
Aims. This paper reports a review conducted to identify the factors in the indoor environment that have an evidence‐based link with the exacerbation or development of asthma and to identify measures ...that healthcare professionals can promote to reduce exposure to these risk factors in the home.
Background. The indoor environment, particularly at home, has been recognized as a major source of exposure to allergens and toxic chemicals. Exposure to allergens and toxins is thought to exacerbate respiratory conditions, in particular, asthma.
Methods. Searches were made of health and indoor environment databases, including Cochrane Library, National Health Services Centre for Reviews and Assessment Reports, British Medical Journal, CINAHL and Ovid library, MEDSCAPE/MEDLINE, EMBASE, INGENTA, Science Citation Index, Web of Science. Searches were also made of other Internet‐based resources, including those of international and government bodies. The following keywords were used: allergens, allergen avoidance, asthma, asthma prevention, cat, damp, Der p 1, dog, environmental control, house dust mites, indoor air quality, indoor environment, meta analysis, mould, pets, remedial actions, respiratory illnesses and systematic reviews.
Findings. There is evidence of a link between asthma and a small number of indoor environmental factors. There is currently only reasonable evidence for one causative factor for asthma in the indoor environment and that is house dust mite allergen. Although there are many studies of different remedial actions that can be taken in the home, often these give evidence of reduced risk of exposure but not clinical improvement in asthma. Although there is a lack of medical evidence for the reduction of known sensitizers such as mould, this is because of a dearth of research rather than evidence of no association.
Conclusions. There is some evidence of a link between the indoor environment and asthma. There are measures, which could be promoted by healthcare professionals to alleviate asthmatic symptoms.
The aim of this study was to examine crevicular polymorphonuclear neutrophils (PMN) of patients with rapidly progressive periodontitis (RPP) for their in vitro phagocytic activity and intracellular ...killing of Porphyromonas gingivalis ATCC 33277 and two strains of Actinobacillus actinomycetemcomitans (NCTC 9710 - type strain and Tanner FDC 44 - leukotoxin producing strain).
18 patients with RPP and nine healthy controls were included in the study. Phagocytosis and intracellular killing were assessed by fluorescence microscopy after staining with acridine orange. The percentage of phagocytosing PMN was determined. The phagocytic cells were then separated into two groups; those containing < 10 phagocytosed bacteria and those containing > 10 bacteria. The percentage of PMN containing viable bacteria was also determined.
The leukotoxic A. actinomycetemcomitans strain was phagocytosed to a lesser degree than the corresponding type strain. The number of phagocytosing cells obtained from the RPP patients did not differ from the controls. However, in healthy subjects there were more phagocytes with more than ten ingested P. gingivalis than in RPP patients. The intracellular killing was diminished in the periodontitis group for P. gingivalis and for both A. actinomycetemcomitans strains.
The PMN of patients with RPP show deficiencies in phagotcytic activity and in the intracellular killing or peridontopathogenic bacteria.
Phagocytosis of periodontopathogenic bacteria by crevicular polymorphonuclear neutrophil granulocytes (PMNs) plays a key role in the aetiology of periodontitis. Antimicrobials such as clindamycin ...have been proven to be effective in treating progressive forms of this disease. Therefore, the purpose of this study was to determine the effect of clindamycin on the phagocytosing properties of gingival crevicular PMNs obtained from 16 patients with rapidly progressive periodontitis (RPP), eight with localized juvenile periodontitis (LJP), 12 with adult periodontitis (AP) and 13 periodontally healthy controls. The phagocytosis assay was performed with the two strains Porphyromonas gingivalis ATCC 33277 and Actinobacillus actinomycetemcomitans Tanner FDC 44 on a slide. Phagocytosis and intracellular killing were assessed by fluorescence microscopy after staining with acridine orange. The addition of clindamycin elevated the percentage of phagocytosing PMNs in periodontitis patients and controls regardless of whether P. gingivalis or A. actinomycetemcomitans was used as test strain. In granulocytes of healthy controls an enhancement of the intracellular killing of both strains was observed if clindamycin was added. Besides the antimicrobial effect, the enhancement of the phagocytosis might be an additional indication for treatment of periodontitis patients with clindamycin.
Microbiological laboratory procedures are involved in diagnosis and therapy control of progressive and refractory forms of periodontitis. In recent years techniques have been developed based on the ...detection of nucleic acids. The purpose of this study was to validate the commercially available micro-Dent(R) test which employs probes for A. actinomycetemcomitans, P. gingivalis, P. intermedia, B. forsythus and T. denticola.
122 plaque samples obtained from periodontal pockets with various depths from 33 early onset periodontitis (EOP) patients and 15 periodontally healthy subjects were analysed by cultivation and the microDent(R) kit.
Both cultivation and the nucleic acid based assay showed a positive correlation of pocket depth with the frequency and quantity of periodontopathogenic species. T. denticola was found only in pockets > 4 mm in EOP patients. Comparison of the two methods revealed that the microDent(R) kit identified both P. gingivalis and B. forsythus more often than did the cultivation method.
Nucleic acid techniques should replace cultivation methods as gold standard in microbiological diagnosis of progressive periodontitis. The micro-Dent(R) kit can be recommended for microbiological laboratories analysing subgingival plaque samples.
Background: Periodontopathogenic bacteria can invade and survive within epithelial cells, but susceptibility of intracellular infection to antibiotics used in periodontitis treatment has not been ...studied to date.
Methods: KB cells were infected by Actinobacillus actinomycetemcomitans, strain NCTC 9710; Porphyromonas gingivalis, strains ATCC 33277 and JH16‐1; or Streptococcus constellatus, strain J012b. After 2, 4, and 12 hours the bactericidal effect of antibiotics (clindamycin, doxycycline, metronidazole, and moxifloxacin) on intracellular microorganisms was tested at a concentration up to the 100‐fold minimum inhibitory concentration (MIC) determined separately on planktonic bacteria.
Results: The P. gingivalis strains differed in their invasiveness and ATCC 33277 was 100‐fold more invasive than JH16‐1. Doxycycline and clindamycin at a concentration 10‐fold MIC had no effect, but P. gingivalis intercellular infection was significantly reduced by metronidazole at 10‐fold MIC after 2 and 4 hours. Moxifloxacin was effective, but a 100‐fold MIC concentration was necessary to reduce P. gingivalis strains intracellular growth to 7% of the control. Other bacterial species grown inside the KB cells were more susceptible to antibiotics. Clindamycin at 10‐fold MIC reduced the number of intracellular S. constellatus after 4 and 12 hours. This bacterium was eliminated by moxifloxacin at 50‐fold MIC. Intracellular A. actinomycetemcomitans was killed by 10‐fold MIC of doxycycline and moxifloxacin after 4 hours incubation.
Conclusions: Moxifloxacin was the most efficient antibiotic to treat intracellular infection. However, taking into account the MIC values and the levels of antibiotics in gingival fluid, elimination of intracellular bacteria by antibiotics alone seems to be questionable. J Periodontol 2004;75:1327‐1334.
Sequences and expression patterns of newly isolated human histone H2A and H2B genes and the respective proteins were compared with previously isolated human H2A and H2B genes and proteins. ...Altogether, 15 human H2A genes and 17 human H2B genes have been identified. 14 of these are organized as H2A/H2B gene pairs, while one H2A gene and three H2B genes are solitary genes. Two H2A genes and two H2B genes turned out to be pseudogenes. The 13 H2A genes code for at least 6 different amino acid sequences, and the 15 H2B genes encode 11 different H2B isoforms. Each H2A/H2B gene pair is controlled by a divergent promoter spanning 300 to 330 nucleotides between the coding regions of the two genes. The highly conserved divergent H2A/H2B promoters can be classified in two groups based on the patterns of consensus sequence elements. Group I promoters contain a TATA box for each gene, two Oct-1 factor binding sites, and three CCAAT boxes. Group II promoters contain the same elements as group I promoters and an additional CCAAT box, a binding motif for E2F and adjacent a highly conserved octanucleotide (CACAGCTT) that has not been described so far. Five of the 6 gene pairs and 4 solitary genes with group I promoters are localized in the large histone gene cluster at 6p21.3–6p22, and one gene pair is located at 1q21. All group II promoter associated genes are contained within the histone gene subcluster at D6S105, which is located at a distance of about 2 Mb from the major subcluster at 6p21.3–6p22 containing histone genes with group I promoters. Almost all group II H2A genes encode identical amino acid sequences, whereas group I H2A gene products vary at several positions. Using human cell lines, we have analyzed the expression patterns of functional human H2A/H2B gene pairs organized within the two histone gene clusters on the short arm of chromosome 6. The genes show varying expression patterns in different tumor cell lines.
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