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Biomedical subjects

E Straube

Publications and source records attributed to E Straube.

At least 37 records · Page 2Linked to original sources
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

Production of basic fibroblast growth factor and interleukin 6 by human smooth muscle cells following infection with Chlamydia pneumoniae.

Chlamydia pneumoniae infection has been associated with asthma and atherosclerosis. Smooth muscle cells represent host cells for chlamydiae during chronic infection. In this study we demonstrated that C. pneumoniae infection of human smooth muscle cells in vitro increased production of interleukin 6 (IL-6) and basic fibroblast growth factor (bFGF) as shown by reverse transcription-PCR, immunoblotting, and enzyme-linked immunosorbent assay. In contrast, levels of platelet-derived growth factor A-chain mRNA were not affected after infection. The stimulation of bFGF and IL-6 production was most effective when viable chlamydiae were used as inoculum. Furthermore, inhibition of bacterial protein synthesis with chloramphenicol prevented up-regulation of IL-6 and bFGF in infected cells. Addition of IL-6 antibody to infected cultures diminished bFGF expression, indicating involvement of produced IL-6. These findings suggest that chlamydial infection of smooth muscle cells elicits a cytokine response that may contribute to structural remodeling of the airway wall in chronic asthma and to fibrous plaque formation in atherosclerosis.

Arteriosclerosis↗
PubMed1999

Immunological parameters in humans exposed to pesticides in the agricultural environment.

Immune parameters were examined in 224 sera of non-exposed controls and in 304 sera of pesticide applicators in the agricultural environment. In comparison to the control group pesticide applicators showed significant increased odds ratios for neopterin and soluble tumor necrosis factor receptor (sTNF RII) and a decreased odds ratio for immunoglobulin M. Obtained results indicate an enhanced macrophage activation and an impaired humoral defense. These alterations have been found to correlate with exposure duration in the group of pesticide applicators in agriculture. For subjects who worked in indoor pest control an inverse correlation for sTNF RII with exposure duration was obtained indicating impairment of cell mediated immune function. It can be concluded that exposure to pesticides in the agricultural environment may contribute to modulation of the immune system. Since immune modulating agents can potentially lead to adverse health consequences the involvement of immune biomarkers in pesticide-related health studies seems to be of considerable value for risk assessment studies.

Antigens, CD↗
PubMed1999

Disruption of male sex hormones with regard to pesticides: pathophysiological and regulatory aspects.

Several pesticides used as herbicides, insecticides and fungicides are known to be endocrine disrupting chemicals (EDCs). In three pair-matched studies we found changes in sex hormone concentrations and T-lymphocytes in relation to acute and chronic pesticide exposure. After acute exposure, 1 day later the concentrations of testosterone and especially estradiol decreased. T4- and T8-lymphocytes slightly increased. Effects of chronic occupational pesticide exposure were expressed by a higher level of testosterone and a larger ratio of T4-/T8-lymphocytes in comparison to control persons. Concentrations of LH in exposed men were higher after exposure than before. We assume an inhibition of the aromatase system by testosterone metabolites. The studies show two effects with regard to the duration of exposure: a hormonal and immune suppression after acute exposure and an activation of both systems following chronic exposure.

CD4-Positive T-Lymphocytes↗
PubMed1999

Expression of interferon regulatory factors and indoleamine 2,3-dioxygenase in Chlamydia trachomatis-infected synovial fibroblasts.

Synovial fibroblasts probably represent host cells for Chlamydia trachomatis during initial intra-articular infection in reactive arthritis. In vitro synovial cells produce interferon-beta (IFN-beta) in response to chlamydial infection. IFN-beta expression can be activated by interferon regulatory factor-1 (IRF-1) and interferon-stimulated gene factor 3gamma (ISGF3gamma). In this study, we demonstrate that infection of synovial fibroblasts with C. trachomatis serotype D induced the expression of IRF-1 mRNA as shown by reverse transcription-PCR. Tumor necrosis factor-alpha (TNF-alpha) stimulation enhanced IRF-1 mRNA levels in infected cells and was required to detect IRF-1 protein by immunoblotting. The level of constitutively expressed IRF-2 was not significantly affected after infection. C. trachomatis was found to cause an up-regulation of ISGF3gamma protein in synovial cells. Induction of the tryptophan-catabolizing enzyme indoleamine 2,3-dioxygenase (IDO) is an important mechanism of the host cell response to control intracellular infection by chlamydiae. It has been described that IRF-1 can induce IDO gene expression. Infection of synovial fibroblasts alone in the absence of exogenous cytokine induced the expression of IDO mRNA which was enhanced by TNF-alpha treatment. The stimulation of IRF-1, ISGF3gamma, and IDO expression was most effective when viable chlamydiae were used as inoculum. Neutralization of IFN-beta in the culture medium of infected cells diminished but did not abrogate expression of IRF-1, ISGF3gamma, and IDO. The increased production of IRF-1 and ISGF3gamma in C. trachomatis-infected synovial fibroblasts may contribute to induction of IFN-beta and IDO.

Antibodies↗
PubMed1999

Detection of Chlamydia trachomatis DNA in cervical samples with regard to infection by human papillomavirus.

OBJECTIVE: The correlation between human papillomavirus (HPV) and Chlamydia, trachomatis infections was evaluated in 144 patients with normal cytology or with atypical squamous cells of undetermined significance (ASCUS). METHODS: Cervical samples were analysed using polymerase chain reaction (PCR) and non-radioactive Southern blot analysis. Specificity and sensitivity of two C. trachomatis PCR systems: major outer membrane protein (MOMP)-PCR and plasmid-PCR were determined. Southern blot hybridization of the PCR amplicons was done using 5' and 3' biotinylated oligonucleotide probes. RESULTS: All cervical samples were tested by the plasmid-PCR due to a 10 times higher sensitivity compared to the MOMP-PCR. To determine the specificity of our C. trachomatis primer sets different bacteria and viruses which can cause urogenital infections were analysed. Comparison of the probes revealed an increased sensitivity of the 5' and 3' double-biotinylated probe vs. the 5' biotinylated probe. The infection rate of C. trachomatis in cervical samples of HPV-positive patients was 10.3% (three out of 29) vs. 1.7% (two out of 115; P< or =0.05) in HPV-negative patients. In patients HPV-X (unsequenced HPV-types) positive the rate was 14.3% (one out of seven) vs. 2.9% (four out of 137: P = 0.2) in HPV-X negative patients. In high risk (HR) HPV-positive cervical samples the infection rate was 9.1% (two out of 22) vs. 2.5% (three out of 122; P = 0.14) in HR HPV-negative samples. Chlamydia trachomatis frequency of patients with cytological changes (ASCUS) was 27.3% (three out of 11) vs. 1.5% (two out of 1 33) in patients with normal cytology (P = 0.003). The highest prevalence rate of C. trachomatis-positive cervical samples (50%; one out of two) was found in HR HPV-positive patients with cytological changes (ASCUS) vs. 5% (one out of 20) in HR HPV-positive patients with normal cytology (P = 0.17). Patients negative for HPV and positive for ASCIIS have a C. trachomatis rate of 22.2% (two out of nine) vs. HPV-negative patients with normal cytology (none out of 106; P = 0.006) and vs. HR HPV-negative patients with normal cytology (0.9%; one out of 113; P = 0.014). CONCLUSIONS: There appears to be a correlation between cervical HPV and cervical C. trachomatis infections. The prevalence rate of C. trachomatis was significantly higher in patients with abnormal cytology (ASCUS) vs. normal cytology.

Blotting, Southern↗
PubMed1999

The influence of ofloxacin (Tarivid) on the parasite-host inter-relationship in patients with chronic urinary tract infection.

In urinary tract infection (UTI), the aim of antimicrobial chemotherapy is either to attenuate the virulence of infective micro-organisms, to influence the interaction between germs and host or to kill bacteria. In 25 females (aged 49.8+/-14.7 years) with chronic UTI, parameters of inflammation (CRP, alpha 2-globulin, leukocytes, ESR) as well as renal function were analyzed under the treatment with ofloxacin 2 x 200 mg. Subsequently, bacterial attachment, bacterial count, leukocytes, antibody-coated bacteria (ACB), immunoglobulin (Ig) G, albumin, a2-microglobulin, Tamm Horsfall protein, secretory IgA (sIgA) and lysozyme were determined in urine. The micro-organisms were examined with regard to the expression of hemolysin, aerobactin, P-fimbriae and according to their plasmid profile. Ofloxacin serum levels were analyzed once prior to, on day 6 during and on day 3 after drug administration. In all cases, the acute clinical symptoms had disappeared after 10 days of treatment, all bacteria were eliminated, and the parameters of inflammation in serum and urine had returned to normal. On the sixth day of therapy, no expression of P-fimbriae was detectable in the Escherichia coli strains isolated, and the attachment rate decreased from 42+/-30.9% to 11.1+/-18.1%. The sIgA level rose from 42.6+68.5 prior to therapy to 88.8+/-136.8 mmol/l on day 3 after therapy; acute symptoms of UTI did not recur in any case during the period of 1 year.

Adult↗
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

Dialysis in neonates with inborn errors of metabolism.

BACKGROUND: Certain inborn errors of metabolism become manifest during the neonatal period by acute accumulation of neurotoxic metabolites leading to coma and death or irreversible neurological damage. Outcome critically depends on the immediate elimination of the accumulated neurotoxins. Recent technological progress provides improved tools to optimize the efficacy of neonatal dialysis. METHODS: We report our experience with continuous venovenous haemodialysis (CVVHD) in six neonates with hyperammonaemic coma due to urea-cycle disorders or propionic acidaemia and in one child with leucine accumulation due to maple-syrup urine disease (MSUD), in comparison with five patients managed by peritoneal dialysis (PD) (2 hyperammonaemia, 3 MSUD). Application of a new extracorporeal device specifically designed for use in small children permitted the establishment of stable blood circuits utilizing small-sized catheters, and the tight control of balanced dialysate flows over wide flow ranges. RESULTS: Plasma ammonia or leucine levels were reduced by 50% within 7.1 +/- 4.1 h by CVVHD and within 17.9 +/- 12.4 h by PD (P<0.05). Also, total dialysis time was shorter with CVVHD (25 +/- 21 h) than with PD (73 +/- 35 h, P<0.02). A comparison of the CVVHD results with published literature confirmed superior metabolite removal compared to PD, and suggested comparable efficacy as achieved with continuous haemofiltration techniques. Apart from accidental pericardial tamponade during catheter insertion in one case, no major complications were noted with CVVHD. In three of the five PD patients, dialysis was compromised by mechanical complications. None of the MSUD patients but four children with urea-cycle disorders died, two during the acute period and two later during the first year of life, with signs of severe mental delay. Of the eight children presenting with hyperammonaemic coma, the four with the most rapid dialytic ammonia removal rate (50% reduction in < 7 h) survived with no or moderate mental retardation, whereas slower toxin removal was always associated with a lethal outcome. Simulation studies showed that the efficacy of neonatal CVVHD is limited mainly by blood-flow restrictions. CONCLUSIONS: While CVVHD is the potentially most efficacious dialytic technique for treating acute metabolic crises in neonates, utmost care must be taken to provide an adequately sized vascular access.

Humans↗
PubMed1999

M protein of a Streptococcus dysgalactiae human wound isolate shows multiple binding to different plasma proteins and shares epitopes with keratin and human cartilage.

Besides group A (GAS), Lancefield group C beta-haemolytic streptococci (GCS) have been implicated as a causative agent in outbreaks of purulent pharyngitis. In this study we have investigated a class CI M protein of a Streptococcus dysgalactiae1:256, revealed that 26% of these sera showed serological cross-reactivity between a 68-kDa cartilage protein and the N-terminal part of MC. Only 8% of the sera of healthy patients showed this property. In additional, MC also cross-reacted with antibodies recognising epidermal keratins. The cross-reacting 68-kDa protein from cartilage was different from human serum albumin, but was recognised with anti-vimentin immune serum. The MC was cloned and the gene sequenced. By using PCR, recombinant gene fragments encoding characteristic peptide fragments of MC were expressed in Escherichia coli. The peptides were used to map the binding sites for plasma proteins and to locate the cross-reacting epitopes on the MC molecule. In consequence, sequence alignments revealed that MC shared homologous regions with vimentin and different keratins. Our data, obtained with MC, suggest that not only infections with GAS but also infections with GCS and possibly GGS (the latter species can also produce class CI M-like proteins) may be responsible for the formation of streptococcal-associated sequel diseases.

Amino Acid Sequence↗
PubMed1998

Beta interferon is produced by Chlamydia trachomatis-infected fibroblast-like synoviocytes and inhibits gamma interferon-induced HLA-DR expression.

Infection of fibroblast-like synovial cells with Chlamydia trachomatis (serotype D strain IC Cal 8) in culture induced the secretion of beta interferon (IFN-beta). Chlamydial infection inhibited IFN-gamma-induced expression of HLA-DR antigen in the cells. Addition of IFN-beta antibody directly to infected cultures mitigated HLA-DR inhibition, suggesting involvement of produced IFN-beta.

Cells, Cultured↗
PubMed1998

In situ hybridisation and direct fluorescence antibodies for the detection of Chlamydia trachomatis in synovial tissue from patients with reactive arthritis.

BACKGROUND: Chlamydia trachomatis is associated with Reiter's syndrome and reactive arthritis but the form in which the organism survives in synovial cells is unclear. AIM: To compare in situ hybridisation with direct fluorescence in the detection of inapparent chlamydial infection in synovial tissue. METHODS: Synovial tissue from four patients with reactive arthritis patients was examined using biotin labelled probes for chlamydial DNA and fluorescein isothiocyanate (FITC) labelled monoclonal antibodies against the major outer membrane protein. RESULTS: In two of the four patients, evidence of chlamydial infections was detected by in situ hybridisation in parallel sections but not with FITC labelled monoclonal antibodies. CONCLUSIONS: Detection of chlamydial DNA by in situ DNA hybridisation may be a better way to identify chlamydial infection in synovial tissue than phenotype targeting with FITC conjugated antibodies, which is used as a standard procedure for screening clinical specimens for chlamydia.

Adult↗
PubMed1998

Secretion of cytokines by human synoviocytes during in vitro infection with Chlamydia trachomatis.

OBJECTIVE: Since Chlamydia-induced reactive arthritis is associated with the presence of viable chlamydiae in the synovial membrane, we studied the ability of Chlamydia trachomatis to stimulate a cytokine response by fibroblast-like synoviocytes in culture. METHODS: Fibroblast-like cells derived from biopsies of the synovial membrane were infected with Chlamydia trachomatis serotype E. Interleukin-6 (IL-6), transforming growth factor-beta (TGF-beta) and tumor necrosis factor-alpha (TNF-alpha) were determined using bio-assays. Granulocyte macrophage colony stimulating factor (GMCSF) was quantified by ELISA. RESULTS: Fibroblast-like synovial cells were capable of supporting chlamydial growth in vitro. Chlamydia trachomatis stimulated synoviocytes to produce IL-6, TGF-beta, and GMCSF. IL-1beta increased the production of IL-6 and GMCSF by mock-infected and infected cells. Treatment of synoviocytes with interferon-gamma resulted in the release of TNF-alpha in response to chlamydial infection. CONCLUSION: Chlamydia-induced cytokine release from synovial fibroblasts may contribute to alterations in the synovial membrane promoting the development of joint inflammation.

Bacteria↗
PubMed1997

[Prevention of reinfection by L-methionine in patients with recurrent urinary tract infection].

PROBLEM: A great variety of different antimicrobial chemotherapeutics is available for the treatment of urinary tract infections. Influencing the course of chronic diseases is a problem because recurrent diseases may result in disturbances of renal and bladder functions as well as in irreversible damages of the renal parenchyma. The present investigations are expected to clarify whether an effective prevention of reinfection in patients with chronically recurrent urinary tract infection is possible by a regular administration of L-methionine (Acimethin). PATIENTS AND METHODS: 33 female patients were included in the examinations. Following acute disease, 23 females (aged: 47.4 +/- 13.3 years) were treated with 3 x 1 tablet of Acimethin (L-methionine) daily over a period of 26 months. Ten female patients (aged: 47.4 +/- 12.2 years) taking 1 tablet of Nevigramon (nalidixic acid) three times daily over 21.6 months served as a control group. Before starting treatment and in the middle of the therapy period control examinations were performed and following the last drug administration so as to assess the therapeutic result. RESULTS: No acute infection occurred during L-methionine treatment. All parameters of inflammation (leucocyte count, C-reactive protein, blood sedimentation rate, alpha 2-globulin concentration) were in the normal range; no impairment of renal function was observed. Although L-methionine, i.e. nalidixic acid, did not yield any significant changes in the range of bacteria, the adherence of uropathogenic microorganisms to the cells of the urinary tract was reduced. Before L-methionine treatment, the average load of the uroepithelial cells was 95.9 +/- 73.6 bacteria per cell. When the observation period was completed, 51.2 +/- 56.4 bacteria per cell were registered (p < 0.03). During nalidixic acid treatment, the rate of adherence was reduced from 74.0 +/- 88.4 to 34.4 +/- 37.8 bacteria per cell (p < 0.25). During L-methionine treatment, no Escherichia coli strains that are able to produce hemolysin or to form aerobactine were found. Among agents adhering to uroepithelial cells, however, an increase in their ability to produce mannose-resistant hemagglutination was conspicuous. CONCLUSION: L-methionine is suitable to prevent reinfection with chronic urinary tract infection. The therapeutic result is essentially due to its influence on bacterial cytoadherence. In contrast to the established recommendations concerning the prevention of reinfection by the use of antibiotics and sulphonamides selecting resistant strains during long-term treatment, nothing is known about the development of resistance to L-methionine.

Adult↗
PubMed1997

Detection of the intercellular adhesion gene cluster (ica) and phase variation in Staphylococcus epidermidis blood culture strains and mucosal isolates.

Staphylococcus epidermidis is a common cause of catheter-associated infections and septicemia in immunocompromised patients. To answer the question whether S. epidermidis skin isolates differ from isolates causing septicemic diseases, 51 strains obtained from blood cultures, 1 strain from shunt-associated meningitis, and 36 saprophytic isolates were characterized. The study demonstrates that most of the blood culture strains formed a multilayered biofilm on plastic material, whereas skin and mucosal isolates did not. Moreover, biofilm-producing strains were found to generate large bacterial autoaggregates in liquid culture. Autoaggregation and biofilm formation on polymer surfaces was associated with the presence of a DNA sequence encoding an intercellular adhesion gene cluster (ica) that mediates the production of a polysaccharide intercellular adhesin. The presence of the intercellular adhesion genes in blood culture isolates was also found to be correlated with the exhibition of black colonies on Congo red agar, whereas the adhesin-negative strains formed red colonies. Upon subcultivation on Congo red agar, the black colony forms of the blood culture strains exhibited red colony variants which were biofilm and autoaggregation negative and occurred at a frequency of 10(-5). The DNA analysis of these S. epidermidis variants by pulsed-field gel electrophoresis and Southern hybridization with an ica-specific gene probe revealed no detectable difference between the black and red colony types. Moreover, after repeated passage, the phenotype of the parent strain could be restored. Therefore, these colony forms were regarded as phase variants. This phenotypic change was observed exclusively in adhesin-positive clinical isolates and not in adhesin-negative saprophytic strains of S. epidermidis.

Bacteremia↗
PubMed1996

Primary cultivation of human synovial cells from nonrheumatic synovial tissue and fluid.

Cultures were established from adherent cells of synovial fluid and from collagenase-dispersed specimens of synovial tissue. In cultures derived from synovial tissue, prolyl hydroxylase-positive cells of fibroblast-like morphology were identified as the predominant cell type. In cultures from synovial fluid the majority of adherent cells was macrophage-like in appearance and strongly positive for CD 68. Cells with a stellate morphology could rarely be observed in cultures from synovial tissue. Their relations to other forms will be discussed. Several simple methods for cultivating adherent synovial cells are presented.

Cell Culture Techniques↗