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Biomedical subjects

G Verbruggen

Publications and source records attributed to G Verbruggen.

At least 37 records · Page 2Linked to original sources
PubMed2001

Flow cytometric analysis of gut mucosal lymphocytes supports an impaired Th1 cytokine profile in spondyloarthropathy.

OBJECTIVE: To quantify the fraction of gut mucosal lymphocytes expressing the T helper type 1 (Th1) cytokines, interferon gamma (IFNgamma) and interleukin (IL)2, and the Th2 cytokines, IL4 and IL10, at the single cell level in patients with spondyloarthropathy (SpA) in comparison with healthy controls. METHODS: An improved extraction protocol was used for the enrichment of intraepithelial lymphocytes (IELs) and lamina propria lymphocytes (LPLs) from colonic and ileal biopsy specimens obtained from patients with SpA (n=20) and healthy controls (n=13). After stimulation with phorbol ester/ionomycin, expression of the intracellular cytokines IFNgamma, IL2, IL4, and IL10 was determined in CD3+, CD3+CD8+ and CD3+CD8- T cells by flow cytometry. RESULTS: In colonic LPLs, a significant decrease in IFNgamma-producing CD3+ cells was observed (p=0.02) in patients with SpA. In the CD3+CD8- subset, the proportion of cells producing IFNgamma and IL2 was decreased in patients with SpA (p=0.021 and p=0.027 respectively). In ileal LPLs, the percentage of IL10-producing CD3+CD8- cells was significantly increased (p=0.046). CONCLUSION: An impaired Th1 cytokine profile is observed in gut mucosal lymphocytes from patients with SpA. This adds to the existing evidence that the gut mucosal immune apparatus is involved in the pathogenesis of SpA.

Adult↗
PubMed2001

Culture of chondrocytes in alginate surrounded by fibrin gel: characteristics of the cells over a period of eight weeks.

OBJECTIVE: To produce tissue engineered cartilage by human articular chondrocytes in vitro for further use in in vivo manipulations for the treatment of cartilage defects. METHODS: Human articular chondrocytes were cultured in 0.5%, 1.0%, and 2.0% of alginate for up to four weeks. The optimal concentration of an alginate matrix for cell replication and for aggrecan synthesis by chondrocytes was determined. DNA content in the different culture conditions was measured after two and four weeks. Aggrecan synthesis rates and accumulation in the surrounding extracellular matrix were assessed by [(35)S]sulphate incorporation after the same periods of culture. To follow the outgrowth of chondrocytes from the alginate beads, chondrocytes were cultured for four weeks in 0.5 or 1.0% alginate surrounded by 0.25 or 0.5% fibrin gel. DNA content of each culture was measured after different culture periods. Finally, human chondrocytes in 1.0% alginate beads were embedded in 0.5% fibrin gel for eight weeks. Immunohistochemical analysis for aggrecan, type I and II collagen was performed weekly. RESULTS: At two weeks the DNA content in each culture significantly increased in 0.5 and 1.0% alginate cultures in comparison with baseline values. This increase continued until week 4 at the three alginate concentrations. Aggrecan synthesis at two weeks was highest in 0.5 and 1.0% alginate cell cultures. At four weeks aggrecan synthesis rates decreased independently of the alginate concentrations. Aggrecan mainly accumulated in the interterritorial matrix. Proliferation of chondrocytes in alginate and outgrowth of these cells in the surrounding fibrin gel were evident throughout the culture period. The accumulation of aggrecan and type II collagen around the cells, in alginate as well as in fibrin gel, gradually increased over the culture period. Type I collagen appeared after six weeks in alginate and in the surrounding fibrin. CONCLUSION: Human chondrocytes proliferate in this culture system, show an outgrowth into the surrounding fibrin, and synthesise a cartilage-like matrix for up to eight weeks.

Aggrecans↗
PubMed2000

Chemical agents and enzymes used for the extraction of gut lymphocytes influence flow cytometric detection of T cell surface markers.

Chemical agents (DTT, EDTA) and enzymes (collagenase, DNAse) are often used for the generation of a single cell suspension from tissue samples. In this study, flow cytometry was used to examine the effect of chemical agents and enzymes on the expression of cell membrane markers of T lymphocytes from tonsils and peripheral blood. Expression of CD4, CD8, CD25, CD38, L-selectin, CD44, alphaEbeta7 and alpha4beta7 were studied. Incubation of lymphocytes with DTT and EDTA resulted in a decrease of CD38, alphaEbeta7 and alpha4beta7 expression. Incubation with collagenase A and DNAse resulted in a decrease of CD25, L-selectin, alphaEbeta7 and alpha4beta7. The results of this study indicate that a careful interpretation is necessary for phenotypic descriptions of lymphocyte populations obtained by enzymatic isolation techniques.

Adolescent↗
PubMed2000

Influence of aging on the synthesis and morphology of the aggrecans synthesized by differentiated human articular chondrocytes.

OBJECTIVE: Synthesis rates of aggrecans by phenotypically stable human articular chondrocytes and the immobilization of these aggrecans in large aggregates were used as variables reflecting the capability of these cells of restoring the extracellular matrix of articular cartilage in vivo in an aging population. DESIGN: Human articular chondrocytes were isolated from articular cartilage obtained from 33 different donors at autopsy. The chondrocytes were cultured in gelled agarose. Synthesis of aggrecans was investigated using Na(2)(35)SO(4)as a radioactive precursor after a 2-week culture period. Electron microscopic study of aggrecan aggregates was done on the macromolecules accumulated over 3 weeks in culture by the chondrocytes obtained from eight other donors with increasing ages. RESULTS: Sulfate incorporation rates into aggrecans correlated inversely with the age of the donor. The value of sulfate incorporation in aggrecans for chondrocytes obtained from mature cartilage of a 20-year-old individual in this system drops to 50% and 25% for chondrocytes obtained from 45- and 69-year-old individuals respectively. Electron microscopic study of aggrecan aggregates showed that the 'de novo' synthesized hyaluronan molecules were fully loaded with aggrecans. Mature human articular cartilage cells were found to synthesize an aggrecan aggregate which carried an average number of 11.7 to 13.1 aggrecans. Cells obtained from immature donors synthesized aggrecan aggregates of which the hyaluronan chain carried twice the amount of aggrecans. These immature human articular cartilage cells were also found to synthesize significant proportions of large aggrecan aggregates with 20 to over 100 aggrecans immobilized on a single hyaluronan chain. The proportions of these large aggrecan aggregates decreased with increasing age of the donors of the chondrocytes. CONCLUSION: The declining aggrecan synthesis rates and the decreased capability of assembling large molecular size aggregates with increasing age in humans illustrates a progressive failure of the repair function of articular cartilage cells in humans.

Adolescent↗
PubMed2000

Erosive and non-erosive hand osteoarthritis. Use and limitations of two scoring systems.

OBJECTIVE: To assess the evolution and progression of osteoarthritis (OA) in the finger joints using anatomical changes on standard radiographs. METHODS: Data obtained from 85 patients enrolled in a prospective study were used to evaluate systems to score the morbidity and the progression of the disease over 3 years. Posteroanterior (PA) radiographs of the metacarpophalangeal (MCP) and interphalangeal (IP) joints were obtained at entry and after 3 years. Assessment of the progression of OA over time is based on: (1) the increase in incidence of OA in previously normal joints during the study period, (2) the changes in the OA-associated features (osteophyte growth, loss of joint space, subchondral cysts or sclerosis) in the pathological finger joints (anatomical lesion progression score system), and (3) the recognition of consecutive anatomical phases in the course of 'erosive' OA (anatomical phase progression score system). RESULTS: Almost 80% of the distal IP and 50% of the proximal IP were affected at study entry. In approximately 40% of the patients, the classical picture of OA of the IP joints was complicated by manifest erosive changes, which were followed by a repair phenomenon in the 'eroded' finger joints. MCP were less affected and showed the non-erosive picture of OA. Numbers of affected DIP, PIP and MCP joints per patient at entry did not differ from those after 3 years of follow-up. Two systems to score the progression of OA (anatomical lesion and anatomical phase progression score system) showed definite progression within 3 years of follow-up, especially in the IP joints. Since changes in both non-erosive and erosive joints were recorded by the anatomical lesion progression system, it was found much more sensitive to change than the anatomical phase progression system which principally recorded the progression through the destructive phases of erosive OA. The results of both progression score systems correlated well. CONCLUSION: Conventional radiographs can be used to assess the morbidity and progression of hand OA. The existence of non-erosive and erosive forms of OA of the finger joints necessitates the use of two scoring systems: the anatomical lesion progression score system and the anatomical phase progression score system.

Adult↗
PubMed2000

Imaging. Radiological assessment of hand OA.

OBJECTIVE: The different radiographic procedures and methods for reading films and assessing the status and progression of hand osteoarthritis (OA) were reviewed. METHODS: The methods that relate to each of the above procedures were assigned to categories upon which there was or was not general agreement. RESULTS: It was agreed that the radiographic method should use published standardized radiographic protocols; that X-ray features should be graded separately for determining the extent of the disease and that changes in osteophyte size was the most sensitive indicator of progression. For epidemiological studies films should be read blind and randomly, but for assessing progression films should be read in pairs and in sequence. No agreement was obtained on the value of the lateral radiographic view of the hand nor on which radiographic atlas would be best for long-term longitudinal studies. CONCLUSIONS: Further work was required to evaluate the role of MRI and scintigraphy in hand OA; radiographic atlases could be improved by incorporating diagrams to illustrate the change in grade for each feature; validation was required for methods of assessment in long-term trials.

Clinical Protocols↗
PubMed2000

Focal up-regulation of E-cadherin-catenin complex in inflamed bowel mucosa but reduced expression in ulcer-associated cell lineage.

The E-cadherin-catenin complex is important for the maintenance of epithelial architecture. We studied its expression in Crohn disease, ulcerative colitis, acute ileitis, and controls. Immunohistochemical stainings for E-cadherin, alpha-catenin, beta-catenin and gamma-catenin were performed. E-cadherin messenger RNA (mRNA) was detected using riboprobes. In active inflammation, there was up-regulation of the complex. In particular, epithelium adjacent to ulcers showed increased expression of protein and mRNA, but in ulcer-associated cell lineage, the intensity of staining was weak to negative. In focal inflammation, up-regulation was found in affected areas. Reparative epithelium growing over denuded areas showed weaker expression. Since structural or functional perturbation in any of the molecules of the E-cadherin-catenin complex results in loss of intercellular adhesion, the preexistent epithelium may benefit from up-regulation to try to maintain its normal architecture under inflammatory conditions. Reduced expression in reparative epithelium and ulcer-associated cell lineage could facilitate the motility of these cells.

Cadherins↗
PubMed2000

Comparative study of the synovial histology in rheumatoid arthritis, spondyloarthropathy, and osteoarthritis: influence of disease duration and activity.

OBJECTIVES: To compare the macroscopic and microscopic characteristics of synovial tissue in rheumatoid arthritis (RA), spondyloarthropathy (SpA), and osteoarthritis (OA) after exclusion of possible biases induced by disease duration or activity, or both. METHODS: Synovial biopsy specimens were obtained by needle arthroscopy in patients with early RA (n=16), late RA (n=14), early SpA (n=23), and OA (n=12). Macroscopic and microscopic features were scored on a four point scale and analysed as a function of disease duration (early versus late RA), local and systemic disease activity, and diagnosis. RESULTS: Except for the maximal synovial lining thickness, no significant differences were seen between early and late RA. For disease activity, synovial histology was only weakly correlated with C reactive protein in RA, but seemed to be strongly dependent on effusion of the biopsied joint in all disease groups. After stratification for local disease activity, no disease related differences were found in patients without joint effusion. In contrast, important differences were found between patients with RA and SpA with active joint effusion. Synovial vascularity was macroscopically increased in SpA versus RA (p=0.017). A straight vessel pattern was only seen in RA, while tortuous vessels were preferentially seen in SpA. Vascularity was also microscopically increased in SpA compared with RA (p=0.031), and correlated with the macroscopic vascularity (r(s)=0.36, p=0.036). CD3+ (p=0.008), CD4+ (p=0.008), and CD20+ (p=0.024) lymphocytes were overrepresented in RA compared with SpA. The integrin expression in RA was characterised by a decrease of alphaVbeta3 in the synovial lining (p=0.006) and an increase of alphaVbeta5 in the sublining (p<0.001). CONCLUSIONS: The immune architecture of the synovial membrane is more dependent on local disease activity than on disease duration. Synovium obtained from clinically affected joints shows important histological differences between RA and SpA.

Adolescent↗
PubMed2000

Subclinical gut inflammation in spondyloarthropathy patients is associated with upregulation of the E-cadherin/catenin complex.

OBJECTIVE: Previously an upregulation of E-cadherin and its associated molecules alpha-catenin, beta-catenin and plakoglobin has been demonstrated in clinically overt inflammatory bowel disease (IBD). The aim of this study was to investigate the expression of the E-cadherin/catenin complex in subclinically inflamed bowel mucosa from spondyloarthropathy (SpA) patients. METHODS: Ileal and colonic biopsy specimens from 19 SpA patients with subclinical inflammatory gut lesions and from seven controls were stained with monoclonal antibodies against E-cadherin, beta-catenin and plakoglobin and a polyclonal antibody against alpha-catenin. E-cadherin mRNA was detected using a riboprobe. Inflammation was histologically classified into acute, chronic active and chronic quiescent forms. RESULTS: In acute and chronic active bowel inflammation of SpA patients, upregulation of the E-cadherin/catenin glycoprotein complex could be observed. Chronic lesions in a quiescent state did not show such an upregulation. Furthermore, chronic inflammation was associated with an increase in E-cadherin mRNA. CONCLUSIONS: As some of the SpA patients with subclinical gut inflammation develop IBD, upregulation of the E-cadherin/catenin complex in inflamed bowel mucosa from SpA patients may point to early cellular changes in the development of IBD. However, at present it cannot be excluded that increased E-cadherin/catenin complex expression is a bystander phenomenon of active inflammation.

Acute Disease↗
PubMed1999

Candida glabrata arthritis: case report and review of the literature of Candida arthritis.

We report a case of arthritis due to Candida (Torulopsis) glabrata in two different joints at different times in the same patient. The first episode of arthritis was situated in the right ankle and lasted more than 1 year before the patient agreed to the proposed treatment. Therapy with intravenous amphotericin B and oral fluconazole failed. A cure was achieved with weekly intra-articular administration of amphotericin B, which was continued for more than 20 weeks and combined with oral itraconazole. Several weeks later the patient developed Candida glabrata arthritis of the left knee while still taking itraconazole. Immediately, intravenous amphotericin B therapy was started and was successful. Because there were no previous invasive point manipulations or trauma, the infections were considered to be haematogenously disseminated. Chronic corticosteroid and repeated antibiotic therapy for infectious exacerbations of chronic obstructive pulmonary disease and alcohol abuse are the presumed risk factors in this otherwise immunocompetent patient.

Adult↗
PubMed1999

Influence of polysulfated polysaccharides on aggrecans synthesized by differentiated human articular chondrocytes.

OBJECTIVE: Synthesis rates of aggrecans by phenotypically stable human articular chondrocytes and the immobilization of these aggrecans in large aggregates have been used as variables reflecting the capability of these cells to restore the extracellular matrix of articular cartilage in vitro. The effects of heparin, chondroitin polysulfate, and xylosan polysulfate on these variables were investigated. METHODS: Human articular chondrocytes were maintained in culture in gelled agarose. After 2 weeks of culture, the media were supplemented for one week with 10 microg/ml each of heparin, chondroitin polysulfate, and xylosan polysulfate. Synthesis of aggrecans was investigated using Na2(35SO4) as a radioactive precursor during the last 24 h of exposure to polysaccharides. Size exclusion chromatography was used to assay the proportions of aggrecans immobilized in aggregates. Native aggrecan aggregates accumulated during culture were liberated in associating conditions by agarase digestion of the artificial agarose matrix and studied by electron microscopy. Hyaluronan synthesis was studied in monolayer cultured chondrocyte derived fibroblasts. The cells were exposed to 3H glucosamine for 24 h after the nutrient media were supplemented with 3 polysaccharides for one week. Size exclusion chromatography was used to assess the length of the hyaluronan filaments. RESULTS: Xylosan polysulfate and chondroitin polysulfate but not heparin significantly increased total 35S incorporation rates in aggrecan. Electron microscopy study of aggrecan aggregates showed that xylosan and chondroitin polysulfate but not heparin significantly increased aggrecan aggregate sizes. The same polysulfated polysaccharides increased the synthesis of high molecular weight hyaluronan by chondrocyte derived fibroblast-like cells. CONCLUSION: Polysulfated polysaccharides significantly increased the synthesis rates and the accumulation of aggrecan in aggregates in the extracellular environment in this in vitro system.

Adult↗
PubMed1998

Chondroitin sulfate: S/DMOAD (structure/disease modifying anti-osteoarthritis drug) in the treatment of finger joint OA.

A total of 119 patients were included in a randomized, double-blind, placebo-controlled trial in order to assess the S/DMOAD properties in OA of chondroitin sulfate (CS 4&6, 3 x 400 mg/day, Condrosulf IBSA, Lugano, CH). Posteranterior roentgenographies of the interphalangeal (IP) joints were carried out at the start of the study and at yearly intervals. This enabled the investigators to document the radiological progression of the anatomical lesions in the pathological finger joints over a 3-year period. It was shown that the progression of OA in the IP finger joints in an individual can be determined by the evolution of his finger joints through previously described anatomical phases: 'N' (not affected), 'S' (classical OA), 'J' (loss of joint space), 'E' (erosive OA) and 'R' (remodeled joint). Structure/disease-modifying anti-OA drug (S/DMOAD) properties were searched for by assaying the number of patients developing OA in previously normal IP joints ('N' > 'S'), or progressing through the described anatomical phases of the disease ('S' > 'J', 'S' > 'E', 'J' > 'E', 'S' > 'R', 'J' > 'R', 'E' > 'R'). In the CS 4&6 group we observed a significant decrease in the number of patients with new 'erosive' OA finger joints. This result is particularly important since OA of the finger joints becomes a clinical problem (pain, functional loss) when 'S' joints progress to 'J' and especially 'E' phases. During and after these 'E' phases, joints will remodel and show the nodular deformities characteristic of Heberden's and Bouchard's nodes. Treated patients were protected against erosive evolution.

Aged↗
PubMed1998

Distinctive activated cellular subsets in colon from patients with Crohn's disease and ulcerative colitis.

BACKGROUND: Activated lymphocytes are considered to play a pathogenic role in Crohn's disease (CD) and ulcerative colitis (UC), although only a limited fraction of the gut-residing lymphocytes in these diseases may be pathogenetically involved, due to active recruitment from the peripheral circulation. Our aim was to characterize in situ preactivated lymphocytes in inflammatory bowel disease mucosa by expansion with interleukin-2. METHODS: Flow cytometry was performed on T cells expanded from the colon of patients with CD (7), UC (16), and controls (20), with special reference to T-cell activation markers and adhesion molecules. RESULTS: In CD a decrease in alpha4beta7 integrin expression was associated with an increase in alphaEbeta7. In UC a similar increase in alphaEbeta7 was observed. Moreover, L-selectin and CD30 were overexpressed on T helper cells in UC versus CD. CONCLUSION: These findings indicate different immunopathogenic pathways for CD and UC.

Biomarkers↗
PubMed1998

A comparative phenotypical analysis of rheumatoid nodules and rheumatoid synovium with special reference to adhesion molecules and activation markers.

OBJECTIVES: (1) To analyse the in situ expression of adhesion molecules in rheumatoid nodules. (2) To compare the endothelial expression of adhesion molecules in synovial tissue and subcutaneous nodules obtained from the same patients. (3) To compare the expression of adhesion molecules and activation markers on T cell lines from nodules and synovium. METHODS: (1) Immunohistochemical analysis by APAAP technique of E selectin, CD44, ICAM-1, PECAM-1, and VCAM-1 was performed on 10 rheumatoid nodules from seven patients with rheumatoid arthritis (RA); nodules and synovium were simultaneously analysed from three patients. (2) T cell lines were generated from RA nodules (n = 7) and synovium (n = 7) by interleukin 2 expansion, and subsequently characterised by flow cytometry for surface expression of alpha E beta 7, alpha 4 beta 7, CD44, L selectin, LFA-1a, PECAM-1, and CD30. RESULTS: (1) In rheumatoid nodules, the palisading layer strongly stains for ICAM-1 and PECAM-1, but less pronounced for CD44. VCAM-1 staining was usually negative. ICAM-1 is upregulated in the vessels surrounding the central zone of fibrinoid necrosis. The immunohistological picture in different nodules derived from the same patient was similar. (2) The endothelial expression of adhesion molecules is comparable in RA nodules and synovium on an individual level, except for E selectin, which is overexpressed in nodule endothelium. (3) T cell lines from nodules and synovium display similar adhesion molecule profiles. However, the expression of CD30, a T cell activation marker linked with Th2 subsets, is higher in nodules compared with synovium. CONCLUSION: These data support a recirculation hypothesis of T cells between articular and extra-articular manifestations in RA, although the activation state of the T cells in each of these localisations may differ.

Adult↗
PubMed1998

Enrichment of T cells carrying beta7 integrins in inflamed synovial tissue from patients with early spondyloarthropathy, compared to rheumatoid arthritis.

OBJECTIVE: To compare the expression of adhesion molecules on synovial T cells from patients with early spondyloarthropathy (SpA) and rheumatoid arthritis (RA), with special reference to the beta7 integrins alpha4beta7 and alphaEbeta7 in view of their intimate association with intestinal tissue. METHODS: Twenty-five synovial cell lines were generated by interleukin 2 (IL-2) expansion from synovial biopsies of patients with early SpA and RA, obtained from macroscopically inflamed synovial tissue by needle arthroscopy, and subsequently characterized by flow cytometry for CD3, CD4, CD8, L-selectin, CD11a, CD31, CD44, and alpha4beta7 and alphaEbeta7 integrin. RESULTS: In SpA, the beta7 integrin expression was increased, compared to RA. Furthermore, an inverse relation between alpha4beta7 and alphaEbeta7 was present in SpA (r = -0.75, p < 0.02), as on many mucosal T cells. In contrast, an opposite correlation was noted in RA (r = +0.84, p < 0.01), as similarly described on a subset of circulating T cells. CONCLUSION: Increased expression of beta7 integrins was noted on synovial T cell lines from SpA compared to RA, with discriminative correlations between alpha4beta7 and alphaEbeta7. This suggests a different origin of the synovial T cells in these diseases.

Adolescent↗
PubMed1996

Numerical scoring systems for the anatomic evolution of osteoarthritis of the finger joints.

OBJECTIVE: To assess and score the progression of osteoarthritis (OA) of the distal and proximal interphalangeal (DIP and PIP) and metacarpophalangeal (MCP) joints. METHODS: Forty-six patients with OA of the finger joints were followed up for 3 years; 36 of them were followed up for 5 years. Posteroanterior radiographs of the hands were obtained at the start of this prospective study and at yearly intervals. The scoring systems used were based on the increased incidence of OA during consecutive years in previously normal joints, the radiologic progression of anatomic lesions in the affected finger joints, and the consecutive pathologic phases recognized in the course of the disease. RESULTS: Significant increases both in the numbers of affected DIP, PIP and MCP joints per subject and in the anatomic progression of the disease (changes in osteophyte growth, loss of joint space, and subchondral cysts or sclerosis) in the different finger joints of each patient were recorded during the 3 and 5 years of followup. In approximately 40% of the patients, the classic picture of OA was complicated by erosive changes, which preceded a period in which repair phenomena in the "eroded" finger joints led to the generation of a new subchondral plate covered by cartilaginous tissue. Huge osteophytes were then responsible for the nodular aspect of the affected finger joints. CONCLUSION: OA of the finger joints is progressive in nature and passes through predictable phases. The recognition of and the attribution of a score to these respective phases made assessing the progression of OA less time-consuming and led to the same conclusions as when the anatomic progression was scored.

Arthrography↗