Biomedical subjects

S Eick

Publications and source records attributed to S Eick.

18 recordsLinked to original sources

PubMed2006

Porphyromonas gingivalis survives within KB cells and modulates inflammatory response.

BACKGROUND/AIMS: The purpose of the study was to investigate the intracellular survival of Porphyromonas gingivalis as a possible mechanism for maintaining periodontitis. METHODS: P. gingivalis strains, the strain ATCC 33277 and seven clinical isolates, were co-cultured with KB cells. The number of intracellular bacteria was determined up to 3 days after infection. In addition, the numbers of KB cells per well, the concentrations of the cytokines interleukin-1beta (IL-1beta), IL-6, IL-8 and tumour necrosis factor-alpha (TNF-alpha) and the arginine-specific amidolytic activity were measured. The 16S rRNA of P. gingivalis and the mRNA expression of IL-1beta, IL-6, IL-8, TNF-alpha and rgpA were also determined. RESULTS: All the P. gingivalis strains studied were able to survive within KB cells. In contrast to the reduced values of colony-forming units at day 3, equal and higher levels of 16S rRNA were seen in comparison to day 0. Arginine-specific amidolytic activity declined in all samples during infection. Expression of mRNA for rgpA was not found after infection of KB cells by P. gingivalis strains. IL-8 was detectable in all samples 2 days after infection with P. gingivalis strains. Principal components analysis underlined a correlation between the arginine-specific amidolytic activity 1 h after infection and both the released IL-8 and the mRNA expression of IL-8. Associations were found between the cultivable numbers of intracellular P. gingivalis and the mRNAs of IL-1, IL-6 and TNF-alpha at the day of infection. CONCLUSION: The results indicate survival of P. gingivalis within epithelial cells, possibly in a non-cultivable stage. Invasion into cells modulates the virulence properties of P. gingivalis as well as the inflammatory response of the cells.

Adhesins, Bacterial↗

PubMed2004

Adherence of Streptococcus mutans to various restorative materials in a continuous flow system.

A continuous flow system was developed to evaluate the adhesion of Streptococcus mutans ATCC 25175 to filling materials (Ariston, Tetric, Dyract, Compoglass, Vitremer, Aqua Ionofil, Ketac Fil, amalgam, Galloy and ceramics as controls). Streptococcus mutans was added to saliva-coated test specimens, and a nutrient broth permanently supplied over a time period of 48 h and then the weight of plaque, the number and viability of the bacteria adhering to the materials were determined. The weights of artificial plaque on all filling materials tested were higher than those on ceramics, the highest values were measured on the glass-ionomers. The amount of plaque correlates with the surface roughness, whereas there was no correlation of the surface roughness with the number of colony-forming units (CFU) of S. mutans. The CFU of adhering S. mutans also depends on the viability of the bacteria. The plaque on Ketac Fil contained a high number of viable bacteria. The fluorides of glass-ionomers do not efficiently prevent the attachment and the viability of S. mutans.

Bacterial Adhesion↗

PubMed2004

Efficacy of antibiotics to strains of periodontopathogenic bacteria within a single species biofilm - an in vitro study.

OBJECTIVES: This study examined differences in the efficacy of antibiotics against a single strain of three periodontal pathogens grown in an artificial biofilm. METHODS: Single species biofilms were established with artificial saliva and one of the following bacterial strains: Actinobacillus actinomycetemcomitans Y4, Streptococcus constellatus 384b (a clinical isolate) and Porphyromonas gingivalis ATCC 33277. The efficacy of the antibiotics clindamycin, doxycycline, metronidazole, and moxifloxacin to these bacteria was determined using concentrations up to 100-fold minimal inhibitory concentration (MIC) to planctonic bacteria over 48 h. RESULTS: The ability of the bacteria to form a biofilm varied. The biofilms of S. constellatus 384b and A. actinomycetemcomitans Y4 contained more viable bacteria and showed a larger thickness in SEM photographs than those of P. gingivalis ATCC 33277. The antibiotics tested showed different efficacy for the different strains. Moxifloxacin was the most efficient antibiotic: onefold MIC was sufficient to eliminate A. actinomycetemcomitans Y4 and P. gingivalis ATCC 33277 after 48 h. However, only the 50-fold MIC completely eradicated S. constellatus 384b. SEM photographs underlined the damaging effect of moxifloxacin on the biofilm structure. CONCLUSION: The complete removal of bacteria by the use of antibiotics alone seems to be impossible when taking into account MIC values and the level of antibiotics in gingival fluid.

Aggregatibacter actinomycetemcomitans↗

PubMed2002

Interaction of Porphyromonas gingivalis with KB cells: comparison of different clinical isolates.

The ability of different Porphyromonas gingivalis strains (15 clinical isolates and ATCC 33277) to attach to and invade KB cells, in relation to other properties such as release of interleukin (IL)-6 and IL-8, cytotoxicity, proteolytic activity and types of fimbriae genes present, was examined. A hierarchical cluster analysis based on adherence and internalization resulted in four groups. Eight of the 15 clinical isolates belonged to a cluster group whose adherence and internalization were about 10% those of the ATCC strain. A negative correlation between lysine-specific protease activity and adherence was found. In all cases the released concentrations of IL-6 and IL-8 were very low. Only one strain was found to be cytotoxic to KB cells. Principal components analysis demonstrated correlations between adherence, internalization and autoaggregation. Most strains had fimA type I and II, type I being associated with elastase-like activity. The ability of P. gingivalis to invade epithelial cells may be a key factor for maintaining periodontal disease.

Bacterial Adhesion↗

PubMed2001

Altered chemotactic behavior of crevicular PMNs in different forms of periodontitis.

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 degrees C, 30 min) using N-formyl-methionyl-leucyl-phenylalanine (FMLP, 1 x 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 x 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.

Adolescent↗

PubMed2000

[Pathogen and resistance spectrum in intraoral infections of the jaw-facial area with special reference to anaerobic bacteria].

The aim of the study was to obtain more knowledge about the aerobic and anaerobic species causing maxillofacial infections and their resistance patterns today. Samples of pus or infectious tissue obtained from 110 patients of maxillofacial surgery were investigated microbiologically by means of aerobic and anaerobic cultivation. After incubation, the cultivated species were isolated and identified. The resistance patterns of all bacteria to penicillin, doxycyclin, and clindamycin were determined. Additionally, the resistance of aerobic species to cefuroxim was documented, and the MICs of cefoxitin and metronidazole to the anaerobic species were assessed. The most frequent disease was periodontitis apicalis (70 patients). Aerobic species alone were found in 23% of the samples, 14% of the infections harbored only anaerobes, but 63% were mixed infections caused by aerobic and anaerobic bacteria. In case of detection of aerobic species, streptococci were always identified. Five patients were infected by Staphylococcus aureus and gram-negative aerobic rods were found in eight patients. Most of the anaerobic species were black pigmented prevotella species (62), nonpigmented prevotellae (56), and fusobacteria (37). Metronidazole and clindamycin were highly efficient to gram-negative anaerobic rods. Most of the oral species were resistant to penicillin and doxycyclin. The indication for applying antibiotics should always be noticed and these drugs should only be used after determination of the pathogenic microorganisms and their susceptibility to the antimicrobials.

Bacteria, Aerobic↗

PubMed2000

Phagocytosis of periodontopathogenic bacteria by crevicular granulocytes is depressed in progressive periodontitis.

BACKGROUND: 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). PATIENTS AND METHODS: 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. RESULTS: 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. CONCLUSION: The PMN of patients with RPP show deficiencies in phagotcytic activity and in the intracellular killing or peridontopathogenic bacteria.

Aggregatibacter actinomycetemcomitans↗

PubMed2000

Clindamycin promotes phagocytosis and intracellular killing of periodontopathogenic bacteria by crevicular granulocytes: an in vitro study.

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.

Adult↗

PubMed2000

Red light kills bacteria via photodynamic action.

With the increase in the number of antibiotic resistant strains of microorganism, the search for alternative treatments of microbial infections becomes all the more important. We report a novel method for bacterial inactivation based on the optical excitation of the naturally occurring (endogenous) photosensitzing porphyrins by red light. In particular, the pathogenic Gram-positive porphyrin producing ATCC strains Propionibacterium acnes, Actinomyces odontolyticus and Porphyromonas gingivalis were investigated. Sensitive autofluorescence spectroscopy revealed that these bacteria naturally synthezise the fluorescent photosensitizer protoporphyrin IX. In addition, bacterial plaque samples of periodontitis patients were studied. Non-labeled fluorescent bacterial colonies were exposed to red light at 632.8 nm, 100 mW/cm2 light intensity and 360 J/cm2 energy density using a helium-neon laser. The survival rate after a single phototreatment with red light was found to be 0.58 +/- 0.09 in the case of Propionibacterium acnes, 0.30 +/- 0.04 in Actinomyces odontolyticus and 0.59 +/- 0.10 in Porphyrormonas gingivalis compared to non-exposed bacteria suspensions. No photoeffect was found for the bacterium Streptococcus mutans which exhibited no detectable porphyrin autofluorescence. Red-light exposed plaque samples of patients showed significant reduction of colony forming units by 50% as well as a pronounced photoeffect on the pigmented species Prevotella intermedia. Taken together, these results suggest the treatment with red light can be potentially employed as an therapeutic method to inactivate certain pathogenic strains of porphyrin producing bacteria without the use of external photosensitizers.

Anti-Bacterial Agents↗

PubMed1999

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.

Anti-Bacterial Agents↗

PubMed1999

The human H2A and H2B histone gene complement.

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 outto 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.

Amino Acid Sequence↗

PubMed1998

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.

Adult↗

PubMed1995

Low incidence of mbr bcl-2/JH fusion genes in Hodgkin's disease.

Lymph node biopsies from 140 cases of Hodgkin's disease (HD) and from 30 non-malignant lesions were screened for the presence of t(14;18) translocations involving the major breakpoint region (mbr) of the bcl-2 gene and the joining region (JH) of the immunoglobulin heavy chain gene, using a polymerase chain reaction (PCR) assay with subsequent nucleotide sequencing of amplified bcl-2/JH junctional regions. Expression of the bcl-2 protein within the Hodgkin and Reed-Sternberg (HRS) cells was investigated in 86 cases of HD by immunohistochemistry on cryostat or paraffin sections. Although bcl-2 expression could be found in a proportion of neoplastic cells in up to one-third of HD cases, the frequency of t(14;18) gene fusions detected by PCR was low. We identified such gene fusions in only 3 out of 140 (2 per cent) HD cases, one biopsy of which presented with four clonally distinct bcl-2/JH sequences. No t(14;18) was found in any of 30 reactive lymph node lesions. All fusion gene sequences were unique regarding the localization of the chromosome 14 and 18 breakpoints and the extranucleotide N-insertions. None of these gene fusions conformed to t(14;18) breakpoint sequences previously characterized in our laboratories. Our findings point to a mere coincidence in some cases of HD lesions and cells carrying a t(14;18) in the same biopsy and argue against a significant role of bcl-2 in the pathogenesis of HD.

Base Sequence↗

PubMed1993

Association of a human H1 histone gene with an H2A pseudogene and genes encoding H2B.1 and H3.1 histones.

A cluster of human histone genes was found on three overlapping clones isolated from cosmid and bacteriophage libraries. These three overlapping segments of the human genome comprise genes coding for H3.1, an H2A pseudogene, and an H2B.1 gene downstream of the previously characterized H1.2 gene. The cosmid clone covers 30 kb upstream of the H1.2 gene and overlaps with two phage clones covering the core histone genes and the pseudogene. The same arrangement of an H3 gene, an H2A pseudogene and an H2B gene downstream of an H1 gene has been described within a mouse histone gene cluster [Yang et al.:J Biol Chem 262:17118-17125, 1987; Gruber et al.:Gene 95:303-304, 1990].

Amino Acid Sequence↗

PubMed1991

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.

Antigens, CD↗

PubMed1990

Sequence analysis of amplified t(14;18) chromosomal breakpoints in B-cell lymphomas.

We have explored different strategies for sequencing of major breakpoint (mbr) junctional regions in t(14;18) chromosomal translocations--the most frequent chromosomal abnormality observed in B-cell lymphomas. We demonstrate that coupling of the preparation of single-stranded DNA by asymmetric polymerase chain reaction (PCR) and direct sequencing is the method of choice for the rapid and precise determination of clone-specific bcl-2/JH fusion gene sequences. The rapidity, relative ease, and accuracy of the technique, described for the nucleotide sequence analysis of mbr t(14;18) breakpoints, permits the analysis of a relatively large number of samples and should be considered as part of the clinical evaluation of lymphoma patients. Furthermore, by providing sequence information of clone-specific DNA regions, the procedure should reduce the risk of false-positive results from PCR.

Base Sequence↗

PubMed1989

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.

Amino Acid Sequence↗

PubMed1988

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.

Anthraquinones↗