Biomedical subjects

M C Creemers

Publications and source records attributed to M C Creemers.

6 recordsLinked to original sources

PubMed1996

Disease activity in ankylosing spondylitis: selection of a core set of variables and a first set in the development of a disease activity score.

A large number of variables are available for the assessment of disease activity in ankylosing spondylitis (AS). The aim of this study was to evaluate the validity of commonly used variables, to select a core set of valid variables for disease activity and finally to compute an AS disease activity score (AS-DAS). Data from two longitudinal studies were used. Principal component analysis and reliability analysis resulted in 11 factors: cervical mobility, lumbar flexion, subjective complaints, functional index (FI), enthesis index (EI), inflammatory response, IgA, IgM, root joints, swollen joints and spinal mobility. Based on discriminating power, reproducibility and correlation with disease duration, seven single variables were selected. In a subsequent discriminant analysis, an AS-DAS was computed of five variables, i.e. subjective complaints, FI, EI, root joints and C-reactive protein, which should be validated in the future. A core set of process variables solves the problem of multiple testing in clinical trials, and improves comparability.

Adolescent↗

PubMed1995

Pseudoporphyria due to naproxen. A cluster of 3 cases.

Pseudoporphyria is a photo-induced blistering disorder with increased skin fragility, caused among others by nonsteroidal antiinflammatory drugs. Lesions heal with scarring and milia. Porphyrin screen studies are normal in this disease. Histology and immunofluorescence resembles porphyria cutanea tarda. In this report we describe a cluster of three cases of naproxen-induced pseudoporphyria, and review briefly previously reported cases induced by naproxen. The majority of reported cases involve children. Physicians should be aware of this reversible skin disorder.

Adult↗

PubMed1995

Methotrexate in severe ankylosing spondylitis: an open study.

OBJECTIVE: To study the efficacy and toxicity of methotrexate (MTX) for patients with ankylosing spondylitis (AS) in a 36 week, open, single observer study. METHODS: Patients were selected for study if they had evidence of active disease and had failed to respond to treatment with nonsteroidal antiinflammatory drugs (NSAID) and sulfasalazine. Eleven patients entered the study, and 9 were evaluated at the end. Oral MTX (7.5-15 mg weekly) was given for at least 24 weeks; NSAID were kept at a stable dose. Efficacy was evaluated by calculating the relative difference of assessed variable between Week 0 and 24 and by patient evaluation. RESULTS: Assessed variables showed good relative improvement. Four patients decided to continue MTX; 3 used a lower dose of NSAID; one stopped NSAID: Five patient patients discontinued MTX: 3 of these had disease flares and restarted MTX. Side effects were mild and reversible. CONCLUSION: Results of our study showed that the majority of our patients with AS taking MTX had beneficial effects.

Adolescent↗

PubMed1994

Ion-pair solid-phase extraction of cimetidine from plasma and subsequent analysis by high-performance liquid chromatography.

An improved method is described for the solid-phase extraction of cimetidine from plasma or serum with subsequent analysis by HPLC. New aspects of the method include protein precipitation with metaphosphoric acid (5%, w/v), followed by selective adsorption of cimetidine and the internal standard ranitidine on the surface of a solid-phase phenyl (PH Bond Elut) column, using octanesulfonate as an ion-pairing agent. Separation was achieved on a LiChrosorb RP-18 column with a mobile phase consisting of acetonitrile-0.01 M phosphate buffer pH 3.0 containing 0.005 M octanesulfonate (22:78, v/v). The intra-assay coefficient of variation varied between 0.7 and 4.0%. The procedure provides cleaner and more stable samples and a better recovery (90 +/- 2.3%) and sensitivity (limit of detection 5 ng/ml and limit of quantitation 25 ng/ml) as compared with previous methods.

Chromatography, High Pressure Liquid↗

PubMed1994

Second-line treatment in seronegative spondylarthropathies.

The literature concerning second-line treatment of seronegative spondylarethropathies from 1940 to August 1993 was reviewed. Sulfasalazine appeared to be effective in the treatment of ankylosing spondylitis (AS) and promising in reactive arthritis (ReA) and Reiters' syndrome (RS). Methotrexate and azathioprine were associated with a remarkable improvement in some cases of AS and RS. Methylprednisolone and levamisole were both efficacious in AS, but levamisole was associated with occasional severe side effects. Radiation therapy led to short-term improvement in AS, but was abandoned because of severe long-term side effects. Only sulfasalazine has been studied in sufficient detail to allow definitive conclusions, but methotrexate and azathioprine may be promising drugs.

Antirheumatic Agents↗

PubMed1994

A Dutch version of the functional index for ankylosing spondylitis: development and validation in a long-term study.

A Dutch Functional Index (DFI) for AS has been developed, containing 37 questions in essence this is a modification of a French index with additional questions. Internal consistency, reproducibility, criterion and construct validity and sensitivity to change were studied in different groups of AS patients. In a group of 149 patients the questionnaire was completed and internal consistency calculated (Cronbach's alpha = 0.94) after exclusion of three items. Reproducibility was studied in 39 patients with stable disease; Pearson correlation was 0.94. Criterion validity, against a 'gold standard' i.e. experts' observation of 25 items, was studied in 19 patients; r = 0.85. In a 48-week NSAID study patients were enrolled after a washout period: DFI scores before and after treatment showed significant improvement (P < 0.02). There were 187 DFI with corresponding clinical measurements, correlations varied from -0.30 to 0.68. Estimated measurement-remeasurement correlation was 0.87. The DFI is, thus, a potentially useful instrument, which is valid, reliable and sensitive to the effects of NSAID treatment.

Adolescent↗