Egbert W. van der Hoek

Radboud University Nijmegen, Nymegen, Gelderland, Netherlands

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Publications (2)5.56 Total impact

  • A Masclee · A Tangerman · A. VAN SCHAIK · E W van der Hoek · J H van Tongeren
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    ABSTRACT: Non-invasive methods to detect small intestinal bacterial overgrowth often lack specificity in patients who have undergone an ileal resection or have an accelerated intestinal transit. Since elevated serum unconjugated bile acid levels have been found in patients with clinical signs of bacterial overgrowth, we studied the clinical value of unconjugated serum bile acids as a marker of small intestinal bacterial overgrowth. Patients with culture-proven bacterial overgrowth had significantly elevated fasting unconjugated serum bile acid levels (median and range: 4.5; 1.4-21.5 mumol l-1) as compared to healthy subjects (0.9; 0.3-1.7 mumol l-1, P less than 0.005), to persons with an accelerated intestinal transit (1.0; 0.3-1.9 mumol l-1, P less than 0.005) and to persons who have undergone an ileal resection (2.1; 0.7-3.6 mumol l-1, P less than 0.005). The same was true 30 and 60 min after ingestion of a Lundh meal. Serum unconjugated bile acid levels above 4 mumol l-1 were found in eight of 10 patients with culture-proven small intestinal bacterial overgrowth whereas serum levels above 4 mumol l-1 were found in none of the patients from the three control groups. These results suggest that determination of unconjugated serum bile acids is of clinical value in the evaluation of patients suspected of small intestine bacterial overgrowth.
    No preview · Article · Sep 1989 · European Journal of Clinical Investigation
  • Albert Tangerman · Annie van Schaik · Egbert W. van der Hoek
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    ABSTRACT: A reliable method is described for the determination of conjugated and unconjugated bile acids in serum and jejunal fluid. Bile acids are extracted using reverse-phase octadecylsilane bonded silica cartridges and are separated into their unconjugated and conjugated fractions using the lipophilic anion exchanger diethylaminohydroxypropyl Sephadex LH-20 (DEAP-LH-20). The conjugated fraction can be separated into a glycine and a taurine fraction, using the same anion exchanger. The bile acids are measured using a hydroxysteroid dehydrogenase-fluorimetric assay for serum and a hydroxysteroid dehydrogenase-photometric assay for jejunal fluid. The normal fasting serum value of total 3 alpha-hydroxy bile acids amounts to 3.5 +/- 2.8 mumol/l (mean +/- SD, range 1.4-10.8, n = 22). The corresponding unconjugated bile acid fraction amounts to 39.9 +/- 11.2% (range 20.7-64.6%) of total bile acids. The concentration of conjugated bile acids became significantly elevated 30, and 60 min after a standard meal, whereas that of unconjugated bile acids remained unchanged. In jejunal fluid only conjugated bile acids are found, as well in fasting subjects as postprandial, 30 or 60 min after a standard meal.
    No preview · Article · Oct 1986 · Clinica Chimica Acta