Biomedical subjects
Publications and source records attributed to F De Keyser.
An increase of the basic atrial pacing rate from a preset value of 70 beats/min up to 91 beats/min was recorded in a patient with an external bipolar dual chamber pacing system. This observation could be explained by the occurrence of crosstalk; this specific manifestation of crosstalk was the result of the use of an uncommitted DVI pacing mode.
An adamantinoma is a rare primary tumour of bone. It is usually seen by stomatologists as a tumour of the jaws, although several cases of the long bones, especially the tibia, have been described. The tumour is considered as a low grade malignancy with unknown histogenesis. It has a high rate of local recurrence after resection and metastasizes in part of the cases. This report describes a 41-year-old woman with multiple pulmonary metastases occurring 27 years after the diagnosis of a tibia adamantinoma. The clinical, radiographic and fiber-bronchoscopic findings are presented. The literature of adamantinoma metastasis is reviewed. The need for an early locally aggressive treatment is stressed as the treatment of metastatic disease seems very disappointing.
We report a case of pyoderma gangrenosum in association with chronic myeloid leukemia. The clinical and pathological features are reviewed and the relationship with hematological disorders is discussed.
In a population of 564 patients with rheumatoid arthritis (RA), the onset of symptoms has been studied in relation to age, sex and last menstrual period for women. Median age of menopause was 49 years (3rd percentile: 32 years and 97th percentile: 56 years). Median age of first symptoms was 45 years in women and 50 in men. The individual interval between menopause and first symptoms has a Gaussian distribution with mean at time 0, implying that the average woman develops the first symptoms at the time of her menopause. The F:M ratio of all patients was 2.3; with increasing age the F:M ratio decreased from 3.7 before 30 years of age to 1 after the 6th decade of life, with a peak at the age of 40-44 years. A possible effect of age related changes in sex hormone levels on the pathogenesis of RA is suggested.
A fast immunoblotting procedure, termed "microgel diffusion blotting," is used to detect and identify antibodies to extractable nuclear antigens (i.e., to Sm, RNP, and SSB) in patients with rheumatic diseases. The method differs from the standard immunoblotting techniques by the use of ultra-thin microgels for polyacrylamide gel electrophoresis: the very thin gel layer allows transfer of proteins to a nitrocellulose membrane by simple diffusion. Principal advantages of this variant technique are its simplicity, rapidity, and reproducibility--characteristics that make the test suitable for routine application. We compared the sensitivity of the test with that of double immunodiffusion in agarose for the evaluation of humoral antinuclear immunity. Microgel diffusion blotting detected antibodies in serum at concentrations less than 0.001 of those detectable by immunodiffusion.
A variant immunoblotting procedure is presented, starting from sodium dodecyl sulfate-containing ultra-thin microgels. The use of these gels allows efficient transfer of proteins to an immobilizing matrix such as nitrocellulose, by simple uni-directional diffusion, without loss of resolution. To this end an assembly was developed, keeping the microgel and the immobilizing matrix in continuous contact. To standardize the technique, two protein extracts (a classical rabbit thymus extract and an original autologous nuclear extract) were used, together with reference antinuclear antisera. The method is fast, easy to perform, and perfectly reproducible. For these reasons, the technique is very suitable for screening a patient's sera on a large scale.
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We have examined a large family in which eleven members have a form of autosomal dominant Ehlers-Danlos syndrome type IV. Analysis of fibroblast cultures from affected individuals showed a partial deficiency of type III collagen production. The protein produced was, however, normal in all aspects examined. Using a restriction site polymorphism associated with the structural gene for human type III collagen (COL3A1), we have found tight linkage between the low frequency polymorphic allele and the clinical expression of the disease (lod = 3.86 at 0 = 0), identifying the type III collagen gene as the disease locus.
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Ehlers-Danlos syndrome (EDS) type I was diagnosed in an 18-year-old girl on the basis of marked skin hyperextensibility with generalized loose-jointedness, pigmented paper-tissue scars, and a pronounced tendency to bruising. Her father and one of her sisters showed a similar phenotype. Her mother was normal. Light microscopy of skin biopsies showed large, irregular collagen fibres in the father and daughter, with normal findings in the mother. Electron microscopy of the skin sections revealed a variation in diameter and shape of the collagen fibrils as well as slight dilatation of the rough endoplasmic reticulum of fibroblasts in father and daughter, but normal findings in the mother. Cultured fibroblasts did not show these changes. Measurements of collagen synthesis by fibroblast cultures showed that type III collagen levels were reduced to 50% of normal in the father and daughter, and were normal in the mother. The alpha I (III) proteins had a normal molecular weight, determined by SDS-PAGE electrophoresis. The phenotypes and biochemical results in the family members tested were compatible with autosomal dominant transmission. To our knowledge, this is the first report of a type III collagen deficiency in Ehlers-Danlos syndrome type I. The findings in this family, especially the pronounced bruising tendency, illustrate the heterogeneity within type I EDS.
The authors discuss the history and use of injections of paraffin, silicone, and collagen for soft-tissue contouring. The structure and uses of collagen are described with particular reference to Zyderm Collagen Implant, a highly purified bovine collagen.
1) A three generations family (44 live born individuals) was investigated concerning the occurrence of Ehlers-Danlos syndrome type IV. 2) Diagnosis was established with clinical data on skin bruisability, bleeding diathesis and ligamentary laxity, especially of the small joints. A striking feature was congenital clubfeet in 7 of 12 affected patients and in one premature baby that lived only 2 days. In 2 of 3 relatives who died abruptly with clinical signs of abdominal bleeding, autopsy demonstrated a ruptured right arteria iliaca communis. 3) Pulse wave velocity was decreased in severely affected patients and normal in mildly affected and in unaffected relatives. Lowered pulse wave velocity apparently objectivates the increased arterial wall distensibility of affected patients. 4) The occurrence of the syndrome amongst the children and grandchildren of one single affected ancestor yields ample evidence for autosomal dominant transmission in this family. 5) Collagen typing and ultrastructural examination were not performed as consent for skin biopsy was not obtained. 6) Further clinical investigation is going on to find out whether miscellaneous signs of abnormal connective tissue in eyes, ears, teeth and palmar fascia are inherent to the observed syndrome or not.
Rheumatoid arthritis is a chronic inflammatory joint disease characterized by the presence of autoantibodies. The best known autoantibody is the rheumatoid factor. Another group of antibodies directed against citrullinated epitopes is proven to be more specific for rheumatoid arthritis. This review gives an overview of the history of the different anti-citrullinated protein antibody detection methods and their diagnostic and prognostic properties in RA.
OBJECTIVES: We investigated the feasibility of using a single multi-parameter test based mainly on recombinant autoantigens for the detection of anti-nuclear autoantibodies, and analyzed the agreement between this test format and conventional techniques. METHODS: The presence of autoantibodies was determined by a line immunoassay (LIA) in 755 sera derived from patients with different autoimmune connective tissue disorders. All sera were previously tested by standard assays that are routinely used at the 8 participating European centers. RESULTS: The overall sensitivity and specificity of autoantibody detection by LIA was similar or higher as compared to combined conventional techniques (CCT). In particular, the detection of anti-Ro52 in systemic lupus erythematosus (SLE) sera (P = 0.004) and anti-LA in both SLE (P < 0.0009) and in Sjögren's syndrome (P < 0.0009) sera was significantly more sensitive when using LIA compared to CCT. By contrast, CCT was never more sensitive than LIA for any of the markers. CONCLUSION: The LIA is a reliable alternative to a combination of conventional techniques for the detection of specific anti-nuclear autoantibodies. The multi-parameter test also reveals autoantibody reactivities that may not be detected when only a limited number of conventional techniques are applied.
The association of hepatitis B virus infection and vasculitis or other immune-mediated manifestations is well documented. Reports on such manifestations in relation to hepatitis B vaccination are scarce, however. We report 2 patients who developed polyarteritis nodosa following vaccination against hepatitis B. In one patient this resulted in an ischemic and necrotic digital ulcus, necessitating surgical amputation. The other patient presented with typical cutaneous polyarteritis nodosa which responded well to corticosteroid treatment. A third patient developed a severe pityrias rosea-like eruption. He was treated with topical steroids with healing of the lesions, leaving only post-inflammatory hyperpigmentation. The literature on these associations is reviewed.
OBJECTIVE: The aim of the study was to evaluate the T cell receptor (TCR) family usage in T cell-lines from subcutaneous nodules and synovium from patients with rheumatoid arthritis (RA), with specific reference to the duration of symptoms. In vitro adherence characteristics of nodular T cells was studied as well. METHODS: Monoclonal antibodies were used to determine the distribution of TCR families in T cell-lines from synovium of patients with early and long-standing RA, from rheumatoid nodules and control tissues. An in vitro binding assay with T cell-lines from 2 rheumatoid nodules was performed. RESULTS: In early RA synovium, a restricted TCR family usage was observed in 5 out of 8 patients, contrary to long-standing disease, peripheral blood, ileum and colon. In RA nodules, a similar degree of restriction was noted. Moreover, the same TCR family was overexpressed by T cell-lines from different nodules derived from the same patient. T cell-lines from rheumatoid nodules demonstrated a preferential in vitro adherence to rheumatoid synovium and rheumatoid nodules, while no binding was observed on skin or tonsil. CONCLUSION: The TCR spectrum among RA synovial cell-lines broadens in relation to the disease duration. The overexpression of the same TCR family in different rheumatoid nodules from the same patients, and the in vitro adherence of T cell-lines from rheumatoid nodules may be indicative for recirculation between the different disease manifestations in RA.
OBJECTIVE: An intriguing link between gut and synovial inflammation exists in patients with spondyloarthropathy (SpA), illustrated by the high frequency of microscopically inflammatory gut lesions observed in these patients. We hypothesise that aberrant homing of mucosal T cells might play a role in the induction/perpetuation of arthritis in SpA. Here, we analyse the expression of the homing molecules alpha4beta7 and alphaEbeta7 on mucosal T cells from patients with ankylosing spondylitis (AS) and controls, in view of the critical role of these receptors in the homing of mucosal lymphocytes. METHODS: Colonic biopsy specimens were obtained from patients with AS (n = 23) and controls (n = 30). Biopsy specimens were immunostained, treated for extraction of intraepithelial lymphocytes (IEL) and lamina propria lymphocytes (LPL) or cultured in the presence of IL-2. The expression of the beta7 integrins was investigated. RESULTS: In situ no differences were observed in alphaEbeta7 and alpha4beta7 integrin expression in isolated IEL and LPL, whether determined by flow cytometry or by immunohistochemical staining. In gut mucosal T cell lines, alphaEbeta7 expression was significantly higher in the mucosa of patients with AS compared with controls. Alpha4beta7 was highly expressed on T cells in both groups studied. Mucosal T cells either expressed only the alpha4beta7 integrin or co-expressed the alpha4beta7 and alphaEbeta7 integrins. Almost none of them expressed only the alphaEbeta7 integrin. CONCLUSION: In gut mucosal T cell lines from patients with AS an increased expression of alphaEbeta7 was observed.