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P Toivanen

Publications and source records attributed to P Toivanen.

At least 37 records · Page 2Linked to original sources
PubMed2000

Interleukin-15 up-regulates the expression of CD154 on synovial fluid T cells.

To investigate the role of the CD40-CD154 interaction in rheumatoid arthritis (RA), we analysed the expression of CD154 on CD3+ and CD4+ T cells in synovial fluid (SF) from patients with RA and in peripheral blood (PB) from patients and normal controls. As interleukin (IL)-15 is a potent activator of synovial T cells we wanted to study whether IL-15 also regulated the expression of CD154 on these T cells. Freshly isolated synovial T cells did not express significant levels of CD154, as evaluated using flow cytometry, whereas the expression of CD86 and human leucocyte antigen (HLA)-DR was significantly elevated on SF T cells when compared with PB T cells from patients or controls. Synovial T cells could up-regulate their CD154 expression following activation with phorbol 12-myristate 13-acetate (PMA) + ionomycin or anti-CD3 + anti-CD28 monoclonal antibodies (mAbs), but the maximal level of expression remained lower than in control T cells. IL-15 significantly increased the expression of CD154 on SF and PB T cells from patients, whereas IL-2 had minimal effects. Furthermore, IL-15 induced extensive proliferation in SF T cells. Our results show that SF T cells up-regulate the expression of CD154 in the presence of IL-15, a cytokine present in the synovium of patients with RA. These results further emphasize the role of IL-15 in the pathogenesis of RA.

Adult↗
PubMed2000

BPI-ANCA is found in reactive arthritis caused by Yersinia and Salmonella infection and recognise exclusively the C-terminal part of the BPI molecule.

OBJECTIVE: To examine the prevalence, binding sites and functional interactions of antineutrophil cytoplasmic autoantibodies (ANCA) against the bactericidal/permeability increasing protein (BPI) in reactive arthritis (ReA). METHODS: Sera were analysed for the occurrence of ANCA by indirect immunofluorescence microscopy (IIF) and ELISA. Binding sites were determined using BPI, lipopolysaccharid binding protein (LBP), and fusion proteins of both proteins in ELISA. In addition, the effect of antibodies on the antibiotic activity of BPI was examined. RESULTS: BPI-ANCA was found in patients with Yersinia- and Salmonella-triggered ReA and directed against the C-terminal portion of BPI. Goat anti BPI antibodies recognising this part inhibited the antibiotic activity of BPI in vitro. CONCLUSION: BPI-ANCA was associated with ReA triggered by Salmonella and Yersinia infection. Directed against the C-terminal part of BPI, it can potentially inhibit its antibiotic activity and might be useful to identify patients with infectious bowel disease prone to extraintestinal sequelae.

Acute-Phase Proteins↗
PubMed2000

What determines arthritogenicity of bacterial cell wall? A study on Eubacterium cell wall-induced arthritis.

OBJECTIVE: To study what determines the arthritogenicity of the bacterial cell wall (CW) using Eubacterium CW-induced arthritis in the rat. METHODS: Eubacterium aerofaciens, previously reported as arthritogenic, and E. limosum and E. alactolyticum, known as non-arthritogenic, were used. Gas chromatography-mass spectrometry (GC-MS) was applied to analyse the chemical composition of the bacterial cell wall. Cellular immune response was measured by concanavalin A (Con A) stimulation and FACScan analysis. Also, serum antibodies against the injected cell wall were determined. RESULTS: Unexpectedly, from the two strains of E. aerofaciens used only one proved to be arthritogenic (with a CW inducing chronic arthritis after a single intraperitoneal injection), even though these two strains were 100% identical by 16S rDNA analysis. CW of the other E. aerofaciens strain induced only transient acute arthritis; CW of E. limosum and E. alactolyticum induced weak signs of acute arthritis. Based on the GC-MS analysis and on the results published previously, putative structures of peptidoglycan (PG) in the four CW preparations are presented. It is apparent that the presence of lysine in position 3 of the PG stem peptide contributes to arthritogenicity but is alone not decisive. Both strains of E. aerofaciens were immunosuppressive, when tested by Con A response at 2 weeks after CW injection. Such an immunosuppression was not observed after injection of CW from E. limosum or E. alactolyticum. FACScan analysis for six T cell markers and studies on serum antibody responses did not reveal any differences in the effect of the four bacterial strains used. CONCLUSIONS: The results obtained suggest that the chemical structure of PG present in the bacterial CW is decisive in determining arthritogenicity/non-arthritogenicity. Therefore, from two bacterial strains belonging to normal human intestinal flora and 100% identical by 16S rDNA analysis, one proved to be arthritogenic and the other non-arthritogenic.

Acute Disease↗
PubMed2000

Reactive arthritis.

During the past year, no big advances were reported in understanding the pathogenesis or treatment of reactive arthritis (ReA). The need for generally accepted diagnostic criteria has become a central issue. Regarding pathogenesis, attention has been drawn to a similarity between ReA and the experimental antigen-induced arthritis. Molecular mechanisms of the HLA-B27-associated pathogenesis have remained, in spite of intensive research, so far a mystery. It is apparent that antibiotics have no effect on the fully developed reactive arthritis, with the exception of patients with Chlamydia-triggered ReA, who might benefit from a course of antibiotics.

Animals↗
PubMed2000

Bacterial cell wall-induced arthritis: chemical composition and tissue distribution of four Lactobacillus strains.

To study what determines the arthritogenicity of bacterial cell walls, cell wall-induced arthritis in the rat was applied, using four strains of Lactobacillus. Three of the strains used proved to induce chronic arthritis in the rat; all were Lactobacillus casei. The cell wall of Lactobacillus fermentum did not induce chronic arthritis. All arthritogenic bacterial cell walls had the same peptidoglycan structure, whereas that of L. fermentum was different. Likewise, all arthritogenic cell walls were resistant to lysozyme degradation, whereas the L. fermentum cell wall was lysozyme sensitive. Muramic acid was observed in the liver, spleen, and lymph nodes in considerably larger amounts after injection of an arthritogenic L. casei cell wall than following injection of a nonarthritogenic L. fermentum cell wall. The L. casei cell wall also persisted in the tissues longer than the L. fermentum cell wall. The present results, taken together with those published previously, underline the possibility that the chemical structure of peptidoglycan is important in determining the arthritogenicity of the bacterial cell wall.

Animals↗
PubMed2000

Direct amplification of rRNA genes in diagnosis of bacterial infections.

A broad-range bacterial PCR targeting rRNA genes (rDNAs) was used to directly analyze 536 clinical samples obtained from 459 hospitalized patients during a 4-year study period. The molecular diagnosis based on DNA sequencing of the PCR product was compared to that obtained by bacterial culture. The bacteriological diagnosis was concordant for 447 (83%) specimens. Broad-range rDNA PCR was the only method that yielded an etiologic diagnosis for 11 (2.4%) of 459 patients. Compared to culture and clinical assessment, the sensitivity of the PCR method combined with sequencing was 74.2%, and the specificity was between 98.7 and 99.6%. At present, the described molecular approach proved superior to bacterial culture in two clinical situations: infections caused by bacteria with unusual growth requirements and specimens taken during antimicrobial treatment of the patient.

Anti-Bacterial Agents↗
PubMed2000

Therapeutic equivalence and acceptability of two multidose powder inhalers in the treatment of asthma.

BACKGROUND: Problems in using conventional inhalation aerosols, in addition to environmental reasons, have driven development of the dry powder inhalers. OBJECTIVE: To compare therapeutic equivalence and acceptability of two dry powder inhalers, Easyhaler (EH) and Diskhaler (DH), in the delivery of beclomethasone dipropionate (BDP) in the treatment of asthma. METHODS: Adult asthmatics (n = 185), previously treated with inhaled steroids, were recruited in this open parallel-group study. After a run-in period of 2 weeks during which the patients inhaled 800 microg/day of BDP via DH, the patients were randomly allocated into three groups: EH 200 group (62 patients) using EH 200 microg/dose inhaler (1 inhalation q.i.d.), EH 400 group (62 patients) using EH 400 microg/dose inhaler (1 inhalation b.i.d.), and DH group (61 patients) using DH 200 microg/dose inhaler (1 inhalation q.i.d.) for 12 weeks. The primary outcome variables were PEF and FEV(1). RESULTS: The 95% CI for treatment difference in morning PEF between the EH 200 and DH groups was -16 to 23 litres/min and between the EH 400 and DH groups -18 to 21 litres/min. There was an increase in the morning PEF of 13 litres/min (p < 0.05) in the EH 200 group, and 9 and 11 litres/min in the DH and EH 400 groups. No differences between the groups were seen in the lung function parameters, in the symptom scores, in the use of rescue medication or in the incidence of adverse events. The treatments had no effects on morning cortisol levels. The patients in the EH groups compared the inhalers by using an 11-item questionnaire. In 8 questions the majority of the patients rated EH superior to DH. CONCLUSION: The tested inhalers were therapeutically equal. However, based on the acceptability data, the EH was better accepted by the patients than DH.

Adult↗
PubMed1999

Joint effects of an aldosterone synthase (CYP11B2) gene polymorphism and classic risk factors on risk of myocardial infarction.

BACKGROUND: The -344C allele of a 2-allele (C or T) polymorphism in the promoter of the gene encoding aldosterone synthase (CYP11B2) is associated with increased left ventricular size and mass and with decreased baroreflex sensitivity, known risk factors for morbidity and mortality associated with myocardial infarction (MI). We hypothesized that this polymorphism was a risk factor for MI. METHODS AND RESULTS: We used a nested case-control design to investigate the relationships between this polymorphism and the risk of nonfatal MI in 141 cases and 270 matched controls from the Helsinki Heart Study, a coronary primary prevention trial in dyslipidemic, middle-aged men. There was a nonsignificant trend of increasing risk of MI with number of copies of the -344C allele. However, this allele was associated in a gene dosage-dependent manner with markedly increased MI risk conferred by classic risk factors. Whereas smoking conferred a relative risk of MI of 2.50 (P=0.0001) compared with nonsmokers in the entire study population, the relative risk increased to 4.67 in -344CC homozygous smokers (relative to nonsmokers with the same genotype, P=0.003) and decreased to 1.09 in -344TT homozygotes relative to nonsmokers with this genotype. Similar joint effects were noted with genotype and decreased HDL cholesterol level as combined risk factors. CONCLUSIONS: Smoking and dyslipidemia are more potent risk factors for nonfatal MI in males who have the -344C allele of CYP11B2.

Adult↗
PubMed1999

Salmonella-triggered reactive arthritis: use of polymerase chain reaction, immunocytochemical staining, and gas chromatography-mass spectrometry in the detection of bacterial components from synovial fluid.

OBJECTIVE: To investigate whether microbial components are present in the cells of synovial fluid or peripheral blood from patients with Salmonella-triggered reactive arthritis (ReA). METHODS: Synovial fluid cells and/or peripheral blood cells from 23 patients with Salmonella-triggered ReA and from 19 control patients with newly diagnosed rheumatoid arthritis were studied using 3 different polymerase chain reaction (PCR) techniques and immunocytochemical staining. Muramic acid from the synovial fluid was studied by gas chromatography-mass spectrometry. RESULTS: Salmonella chromosomal DNA was not detectable in the synovial fluid cells and peripheral blood leukocytes of patients with Salmonella ReA. Initially, positive reactions were observed in the synovial fluid cells and peripheral blood leukocytes of 3 of 17 and 3 of 18 patients with ReA, respectively, but in the subsequent PCR studies, these findings were not reproducible. Salmonella-specific antigen was detectable by immunofluorescence in the synovial fluid cells and peripheral blood leukocytes of 4 of 11 and 2 of 7 patients with ReA, respectively. Muramic acid was present in 2 of 15 synovial fluid samples from patients with ReA, but the bacterial cultures from synovial fluid were negative. CONCLUSION: These findings indicate the presence of bacterial degradation products, but not bacterial DNA, in the inflamed joints of patients with Salmonella-triggered ReA.

Adolescent↗
PubMed1999

Expression of soluble human signaling lymphocytic activation molecule in vivo.

BACKGROUND: Signaling lymphocytic activation molecule (SLAM) is a novel glycoprotein expressed on activated T and B cells. Ligation of cell surface SLAM, either by anti-SLAM mAbs or the recombinant soluble form of SLAM (sSLAM), enhanced the proliferation of T and B cells in vitro. In addition, the engagement of SLAM on T cells preferentially induced IFN-gamma production even by allergen-specific TH2 clones. OBJECTIVE: In this study we investigated the expression of sSLAM in vivo in healthy individuals and in disease conditions that are associated with increased TH1 - or TH2 -cell responses. METHODS: The expression of mRNA encoding sSLAM in peripheral blood and synovial fluid (SF) lymphocytes was studied by using reverse transcriptase-PCR, and the presence of sSLAM protein in serum and SF samples was investigated by using a specific ELISA. RESULTS: Lymphocytes from patients with rheumatoid arthritis (RA) and healthy individuals consistently expressed mRNA encoding sSLAM. In addition, sSLAM protein was present in 38% of serum and 54% of SF samples from patients with RA and in 47% of serum samples from healthy individuals. The levels of sSLAM in positive serum and SF samples from patients with RA and in positive serum samples from healthy individuals were not significantly different. In contrast, the levels of sSLAM were significantly lower in patients with reactive arthritis or in patients with elevated IgE levels than in patients with RA. Similarly, the frequency of positive SF samples was significantly lower in reactive arthritis (28%) than in RA (54%). CONCLUSION: These results indicate that sSLAM is present in serum and SF, further suggesting that sSLAM regulates T- and B-cell function in vivo. Moreover, these data suggest an association between low sSLAM production and the occurrence of TH2 responses in vivo.

Antigens, CD↗
PubMed1999

Human cytokine responses induced by gram-positive cell walls of normal intestinal microbiota.

The normal microbiota plays an important role in the health of the host, but little is known of how the human immune system recognizes and responds to Gram-positive indigenous bacteria. We have investigated cytokine responses of peripheral blood mononuclear cells (PBMC) to Gram-positive cell walls (CW) derived from four common intestinal indigenous bacteria, Eubacterium aerofaciens (Eu.a. ), Eubacterium limosum (Eu.l.), Lactobacillus casei (L.c.), and Lactobacillus fermentum (L.f.). Our results indicate that Gram-positive CW of the normal intestinal microbiota can induce cytokine responses of the human PBMC. The profile, level and kinetics of these responses are similar to those induced by lipopolysaccharide (LPS) or CW derived from a pathogen, Streptococcus pyogenes (S.p.). Bacterial CW are capable of inducing production of a proinflammatory cytokine, tumour necrosis factor-alpha (TNF-alpha), and an anti-inflammatory cytokine, IL-10, but not that of IL-4 or interferon-gamma (IFN-gamma). Monocytes are the main cell population in PBMC to produce TNF-alpha and IL-10. Induction of cytokine secretion is serum-dependent; both CD14-dependent and -independent pathways are involved. These findings suggest that the human cytokine responses induced by Gram-positive CW of the normal intestinal microbiota are similar to those induced by LPS or Gram-positive CW of the pathogens.

Antibodies, Monoclonal↗
PubMed1999

Synovial fluid T cells from patients with rheumatoid arthritis are refractory to the T helper type 2 differentiation-inducing effects of interleukin-4.

The balance between T helper type 1 (Th1) and Th2 cytokines is thought to be important in the initiation and outcome of autoimmune diseases. The goal of the present study was to compare the production of interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) by synovial fluid (SF) and peripheral blood (PB) CD4+ and CD8+ cells from patients with rheumatoid arthritis (RA) using three-colour immunofluorescence staining and flow cytometry, and to investigate the capacity of IL-4, IL-10 and IL-12 to modify the cytokine production profile of SF T cells. The frequency of IFN-gamma-producing CD4+ and CD8+ cells was significantly increased in SF when compared with PB. In contrast to IFN-gamma, the expression of IL-4 in SF and PB T cells was comparable. The majority of IL-4-producing cells in SF belonged to Th0/T cytotoxic (Tc) type 0 phenotype, whereas there were significantly more Th2/Tc2 cells in PB than in SF. Interestingly, IL-4 was unable to induce differentiation of non-adherent SF mononuclear cells (SFMC) into Th2 cells, whereas PB mononuclear cells (PBMC) under similar culture conditions differentiated into cells producing high levels of IL-4, IL-10 and IL-13. In contrast, there were no major differences in the effects of IL-10 and IL-12 on the cytokine production profile of SFMC when compared with PBMC. Taken together, the present results suggest that SF T cells from patients with RA are terminally differentiated into Th1/Tc1-like phenotype, and Th2/Tc2 differentiation-inducing agents, such as IL-4, may not be able to reverse the inflammatory process occurring in the joints.

Adult↗
PubMed1999

Expression of the myc-family proto-oncogenes and related genes max and mad in synovial tissue.

OBJECTIVE: To examine the expression of myc proto-oncogenes; c-myc, L-myc, and N-myc, and their related genes max and mad, in the arthritic synovium. METHODS: Using reverse transcription-polymerase chain reaction (RT-PCR), Northern and Southern hybridizations, the expression of these genes in the synovial tissue from rheumatoid arthritis (RA) and osteoarthritis (OA) was analyzed. Synovial specimens from cadavers without any joint disease and peripheral blood mononuclear cells (PBMC) from healthy individuals served as controls. RESULTS: As a novel finding, synovial cells were observed to express L-myc, N-myc as well as their related genes max and mad, in addition to the previously described presence of c-myc proto-oncogene in synovium. c-myc, L-myc, N-myc, and mad were expressed in all patient samples studied, including the controls. Instead, max was detected in only 10/12 of RA patients, in 11/13 of OA patients, and in all controls (4/4 cadavers, 5/5 blood donors). Six patients with RA revealed positive signals for max only after hybridization. The same was also true of two patients with OA and of one healthy individual donating blood. CONCLUSIONS: The L-myc, N-myc, max, and mad genes are expressed in synovial cells, in addition to c-myc proto-oncogene. However, expression of these genes is not disease-specific, since they were equally expressed in synovial samples from patients with RA or OA as well as from cadavers representing controls without any joint disease.

Adult↗
PubMed1999

Somatic serogroups, capsular types, and species of fecal Klebsiella in patients with ankylosing spondylitis.

The purpose of the present study was to find out whether patients with ankylosing spondylitis (AS) carry fecal Klebsiella strains that belong to serotypes or species specific for AS. Somatic serotypes (O groups), capsular (K) serotypes, and biochemically identified species were determined for fecal klebsiellae isolated from 187 AS patients and 195 control patients. The controls were patients with fibromyalgia or rheumatoid arthritis. The 638 isolates of Klebsiella that were obtained represented 161 strains; 81 from AS patients and 80 from the controls. The average number of Klebsiella strains per patient was 1.7 for the AS group and 1.5 for the control group. The most common O group was O1, which was observed for isolates from 23 of 187 AS patients and 24 of 195 control patients. Next in frequency was group O2, which was observed for isolates from 17 AS patients and 15 control patients. Regarding the K serotypes, 59 different types were identified, revealing a heterogeneous representation of Klebsiella strains, without a predominance of any serotype. By biochemical identification, Klebsiella pneumoniae was the most frequently occurring species, being found in 45 AS patients and 45 control patients. Next in the frequency was K. oxytoca, which was observed in 26 AS patients and in 29 control patients. K. planticola and K. terrigena occurred in only a minority of patients. Altogether, when analyzed either separately or simultaneously according to O groups, K serotypes, and biochemically identified species, no evidence of the existence of AS-specific Klebsiella strains was obtained. These findings do not indicate participation of Klebsiella in the etiopathogenesis of AS.

Adult↗
PubMed1999

Two forms of reactive arthritis?

Inflammatory arthritides developing after a distant infection have so far been called reactive or postinfectious, quite often depending on the microbial trigger and/or HLA-B27 status of the patient. For clarity, it is proposed that they all should be called reactive arthritis, which, according to the trigger, occurs as an HLA-B27 associated or non-associated form. In addition to the causative agents and HLA-B27, these two categories are also distinguished by other characteristics. Most important, HLA-B27 associated arthritis may occur identical to the Reiter's syndrome with accompanying ureteritis and/or conjunctivitis, whereas in the B27 non-associated form this has not been clearly described. Likewise, only the B27 associated form belongs to the group of spondyloarthropathies.

Arthritis, Reactive↗
PubMed1999

Detection of Salmonella infantis in synovial fluid cells of a patient with reactive arthritis.

We investigated a patient with Salmonella infantis triggered reactive arthritis (ReA) for a possible occurrence of S. infantis-specific antigens and DNA in the synovial fluid (SF) cells. S. infantis-specific antigens were abundantly observed by immunofluorescence in SF cells of the patient during acute joint inflammation. Salmonella-specific DNA was detected by Southern blotting of the amplified polymerase chain reaction product once, but the result could not be repeated. It seems that if bacterial DNA exists in inflamed joints in Salmonella triggered ReA, its amount is extremely low. This is the first report of intraarticular S. infantis antigens and potentially of Salmonella DNA in Salmonella triggered ReA.

Adolescent↗
PubMed1998

Detection of HLA-B27 alleles by group-specific amplification and time-resolved fluorometry.

This newly developed HLA-B27 assay combines a polymerase chain reaction (PCR) from blood spot samples with solution hybridisation in microtitration plate and with time-resolved fluorometry (TRF) as the detection system. In a multiplex amplification reaction, the 144 base pair region of HLA-B27 alleles is amplified with allele-specific primers simultaneously with the region of beta-actin gene as an internal control. Amplified products are collected onto streptavidin (SA)-coated microtitration wells, denatured and hybridised with a europium (Eu)-labelled HLA-B27 specific probe and a samarium (Sm)-labelled beta-actin specific probe. Finally, Eu and Sm fluorescence is enhanced and detected in a time-resolved fluorometer. The typing results obtained with 110 blood spot samples showed an exact match with serological class I HLA-typing. When this technique was further evaluated, 348 blood spot samples were clearly categorised into two populations, HLA-B27 positives and negatives. This new PCR-TRF method permits the automation of HLA-B27 assays and saves time and labour in routine diagnostics.

Alleles↗