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Featured researches published by P.A.M. Van Hees.


Gut | 1980

An index of inflammatory activity in patients with Crohn's disease.

P.A.M. Van Hees; P H van Elteren; H. J. J. Van Lier; J. H. M. Van Tongeren

An objective and quantitative standard of inflammatory activity for patients with Crohns disease was developed. This Activity Index (AI) was derived from data of 63 patients with Crohns disease who had been submitted to a total of 85 clinical examinations. On the basis of 18 predictor variables three physicians gave an overall evaluation of the severity of inflammatory activity in each patient. Stepwise multiple regression analysis was used to investigate which combination of variables contributed most to the overall evaluation. The combination of the following nine variables gave a very good correlation (r = 0.95) with the overall evaluation: serum albumin, ESR, body weight related to length, abdominal mass, sex, temperature, stool consistency, bowel resection, and extraintestinal symptoms related to Crohns disease. This combination of variables expressed in a score that was used as an activity index proved to be very useful in the assessment of disease activity and of the effect of therapy. Index values below 100 are associated with inactive disease, values between 100 and 150 can be regarded as indicating slight inflammatory activity, values between 150 and 210 as indicating moderate, and values above 210 as indicating severe-to-very-severe inflammatory activity.


Gut | 1980

Effect of sulphapyridine, 5-aminosalicylic acid, and placebo in patients with idiopathic proctitis: a study to determine the active therapeutic moiety of sulphasalazine.

P.A.M. Van Hees; J H Bakker; J. H. M. Van Tongeren

Suppositories of sulphapyridine, 5-aminosalicylic acid, and placebo were used in 45 patients with idiopathic proctitis to determine the active part of sulphasalazine. Each patient used one of the suppositories twice daily for four weeks in a double-blind controlled trial. Complete clinical remission with normal rectal mucosa on sigmoidoscopy occurred in 60% of patients given 5-aminosalicylic acid, but in only 13% and 27% of those given sulphapyridine and placebo respectively. Twelve patients were included twice. In eight of these patients 5-aminosalicylic acid was given one time and sulphapyridine (two patients) or placebo (six patients) another time. Clinical remission occurred in each patient with 5-aminosalicylic acid, but in only one patient during other therapy. The results suggest that 5-aminosalicylic acid is the active therapeutic moiety of sulphasalazine.


Gut | 1981

Effect of sulphasalazine in patients with active Crohn's disease: a controlled double-blind study.

P.A.M. Van Hees; H. J. J. Van Lier; P H van Elteren; M Driessen; R. A. van Hogezand; G P Ten Velde; J H Bakker; J. H. M. Van Tongeren

The response of active Crohns disease to sulphasalazine (4-6 g per day) has been studied in a placebo-controlled trial. The study was carried out at two hospitals. From August 1977 to August 1979 all patients with established Crohns disease were examined for their eligibility for the trial. A nine-item index of inflammatory activity was used as the primary measure of response. The variables in this index were serum albumin, ESR, body weight released to height, abdominal mass, temperature, stool consistency, bowel resection, and extraintestinal symptoms related to Crohns disease. A favourable response to therapy was defined as a decrease of the activity index with 25% or more at the end of the trial period, compared with the initial value. Twenty-six patients (13 in each treatment group) have been followed up for six months. The response of active Crohns disease to sulphasalazine was significantly better than to placebo.


Gastroenterology | 1985

Disposition of disodium azodisalicylate in healthy subjects. A possible new drug for inflammatory bowel disease.

R.A. van Hogezand; P.A.M. Van Hees; B. Zwanenburg; J.M. van Rossum; J. H. M. Van Tongeren

The disposition of disodium azodisalicylate and salicylazosulfapyridine was studied in 6 healthy volunteers. After a single oral dose (1.0 g disodium azodisalicylate; 2.3 g salicylazosulfapyridine) maximum serum concentrations of the intact compound ranged between 1.4 and 6.8 mumol/L and 32 and 114 mumol/L, respectively. Mean residence time and serum half-life of disodium azodisalicylate were considerably longer than those of salicylazosulfapyridine, probably because of a higher apparent volume of distribution. Both compounds were largely split by colonic bacteria and comparable amounts of the active moiety, (acetyl-)5-aminosalicylic acid, were recovered in feces. During long-term ingestion of disodium azodisalicylate (1.0 g/day) it took 6-19 days to reach a steady state. Serum concentrations of disodium azodisalicylate at steady state were low: 2.2-8.4 mumol/L. The serum half-life was 6-10 days. It is concluded that the disposition of disodium azodisalicylate is similar, in important respects, to that of salicylazosulfapyridine. Disodium azodisalicylate, therefore, deserves therapeutic trial.


Alimentary Pharmacology & Therapeutics | 2007

Double‐blind comparison of 5‐aminosalicylic acid and acetyl‐5‐aminosalicylic acid suppositories in patients with idiopathic proctitis

R.A. van Hogezand; P.A.M. Van Hees; J. P. W. M. Van Gorp; H. J. J. Van Lier; J H Bakker; P. Wesseling; U.J.G. van Haelst; J. H. M. Van Tongeren

Suppositories containing 300 mg 5‐aminosalicylic acid (1.96 mmol) or 425 mg acety1‐5‐aminosalicylic acid (1.96 mmol) were used in 40 patients with idiopathic proctitis to determine the efficacy of acetyl‐5‐aminosalicylic acid in treating this bowel inflammation. Each patient was treated with 5‐aminosalicylic acid or acetyl‐5‐aminosalicylic acid suppositories twice daily for 4 weeks in a double‐blind trial. Four patients were included twice in the trial. The second time they were treated with the alternative regimen. Six patients in the acetyl‐5‐aminoscylic acid group did not complete the trial, four of them because of diarrhoea. Complete clinical remission with normal rectal mucosa on sigmoidoscopy was achieved in 10 out of 18 patients on 5‐aminosalicylic acid and in only two out of 15 in the acetyl‐5‐aminosalicylic acid group (P= 0.03). A favourable histological improvement was demonstrated with 5‐aminosalicylic acid suppositories, but the difference with acetyl‐5‐aminosalicylic acid was not significant (P= 0.059). Three of the four patients who received both drugs recovered with 5‐aminosalicylic acid; in none of them was acetyl‐5‐aminosalicylic acid effective. The results from this study and from previous investigations show that acetyl‐5‐aminosalicylic acid is not superior to placebo.


Gut | 1979

Influence of intestinal transit time on azo-reduction of salicylazosulphapyridine (Salazopyrin).

P.A.M. Van Hees; J. H. M. Tuinte; J.M. van Rossum; J. H. M. Van Tongeren

During a normal and an accelerated intestinal transit, in seven healthy volunteers, the recoveries of salicylazosulphapyridine (SASP) and its split products sulphapyridine (SP) and 5-aminosalicylic acid (5-ASA) were determined in urine and faeces. The azo-reduction of SASP and consequently the recovery of 5-ASA in the faeces was found to be substantially decreased during an accelerated intestinal transit. In addition, in 18 patients with inflammatory disease of the colon during maintenance therapy of SASP it could be demonstrated that the serum SP levels were related to the diarrhoeal state and did not correlate with disease activity. As recent studies have reported that 5-ASA is possibly the active therapeutic moiety of SASP, the ineffectiveness of SASP therapy in patients with active colitis may be ascribed to the reduced azo reduction of SASP as the result of profuse diarrhoea.


European Journal of Clinical Pharmacology | 1992

Bacterial acetylation of 5-aminosalicylic acid in faecal suspensions cultured under aerobic and anaerobic conditions.

R. A. van Hogezand; H. M. Kennis; A. Van Schaik; J. P. Koopman; P.A.M. Van Hees; J. H. M. Van Tongeren

SummaryAfter oral administration of 5-aminosalicylic acid a substantial proportion of the acetylated form is excreted in the faeces. We have studied the role of the faecal microflora in acetylating 5-aminosalicylic acid.In faeces incubated under both aerobic and anaerobic conditions there was acetylation of 5-aminosalicylic acid. Of the anaerobic bacteria isolated from a 108 faecal dilution 44% were able to acetylate 5-aminosalicylic acid.We conclude that the normal faecal microflora contribute to the acetylation of 5-aminosalicylic acid.


European Journal of Drug Metabolism and Pharmacokinetics | 1988

Stability of disodium azodisalicylate (olsalazine) and metabolites in urine and faeces stored at different temperatures

R. A. van Hogezand; A. Van Schaik; P.A.M. Van Hees; J. H. M. Van Tongeren

SummaryMethods: The stability of disodium azodisalicylate, 5-aminosalicylic acid and acetyl-5-aminosalicylic acid dissolved in distilled water and in urine or mixed with faeces to which HgCl2 was added, was studied at −20°C, 4°C and room temperature.Results: In water, no marked differences were found between the three storage regimens. In urine, disodium azodisalicylate and acetyl-5-aminosalicylic acid were stable, while the 5-ASA concentration decreased when stored at 4°C and room temperature. In faeces stored during seven days, a marked decrease in 5-aminosalicylic acid concentration to about zero was found when it was kept at 4°C and room temperature. No marked change in the concentration of disodium azodisalicylate and 5-aminosalicylic acid added to the -HCl2-mixtures appeared.


The Lancet | 1978

ACTIVE THERAPEUTIC MOIETY OF SULPHASALAZINE

P.A.M. Van Hees; J. H. M. Van Tongeren; J H Bakker; H. J. J. Van Lier


Journal of Chromatography B: Biomedical Sciences and Applications | 1984

Determination of sodium azodisalicylate, salazosulphapyridine and their metabolites in serum, urine and faeces by high-performance liquid chromatography

R. A. van Hogezand; H.C.J.G. Van Balen; A. Van Schaik; Albert Tangerman; P.A.M. Van Hees; B. Zwanenburg; J. H. M. Van Tongeren

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H. J. J. Van Lier

Radboud University Nijmegen

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J H Bakker

Radboud University Nijmegen

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B. Zwanenburg

Radboud University Nijmegen

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J.M. van Rossum

Radboud University Nijmegen

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R.A. van Hogezand

Radboud University Nijmegen

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Albert Tangerman

Radboud University Nijmegen

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H. M. Kennis

Radboud University Nijmegen

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H.C.J.G. Van Balen

Radboud University Nijmegen

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