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A high-performance liquid chromatographic method for the simultaneous determination of 5-amino-salicylic acid (5-ASA) and N-acetyl-5-ASA (Ac-5-ASA) concentrations in endoscopic mucosal biopsy homogenates is presented. The mean recoveries of 5-ASA and Ac-5-ASA from spiked blank biopsy homogenates ranged from 95.9 to 120% and from 92.5 to 100%, respectively. The coefficients of variation for 5-ASA and Ac-5-ASA were 0.7-8.6% and 1.4-12.9%, respectively. This method is useful for direct determination of topical availability of 5-ASA and Ac-5-ASA and probably an accurate parameter of drug bioavailability.

A method has been developed for quantitative determination of pinaverium-bromide, a quaternary ammonium derivative with papaverine-like activity, in human serum. The method involves a chloroform extraction of serum spiked with N-(6,6-dimethyl bicyclo[3.1.1]2-heptenyl-ethoxyethyl) perhydro-1,4-oxazine as internal standard. After evaporation of the solvent, and reduction of the residue with Raney-Nickel, the internal standard and the reduced pinaverium-bromide are re-extracted from the reaction mixture with toluene and analysed isothermally on a fused silica column coated with OV-101. Although chemical ionization with methane revealed intense protonated molecular ions for both pinaverium-bromide and the internal standard, selectivity and sensitivity were significantly lower in comparison with electron impact ionization at 70 e V. Therefore, quantification was performed in the electron impact mode by single ion monitoring of the common fragment ion at m/z 100.2. A linear detector response was observed up to 160 ng ml-1. A within-run assay precision better than 2% CV (n = 5) was found, and a detection limit of 1 ng pinaverium-bromide ml-1 of serum was attained.

Quantification of bile acids has been carried out by selected ion monitoring and by repetitive scanning. The latter method has been explored critically and found to be very suitable. A 24 h collection of feces was submitted to Soxhlet extraction. The extract was purified on Servachrom XAD-2, and separated into sulfated and non-sulfated fractions over DEAP-Sephadex-LH20. Conjugated and sulfated bile acids were enzymatically deconjugated and desulfated prior to permethylation. Deuterated bile acid derivatives were added as external standards and an aliquot was injected onto a capillary column of SE-52. The reconstructed chromatogram traces of specific ions were integrated to quantify known bile acids. Spectra of all metabolites were available for identification purposes simultaneously.

Because of a biological difference between both primary hydroxylgroups of glycerol there are three distinct hydroxylgroups esterified with fatty acids in triglycerides. The distribution of fatty acids in the three distinct positions of triglycerides can be investigated by a combination of partial hydrolysis of triglycerides by pancreatic lipase, phosphorylation of the diglycerides formed and the stereospecific action of phospholipase A on phosphatides. Plasma triglycerides from normal and hyperlipemic humans are analysed. Human plasma triglycerides are highly asymmetric. The 1-position contains more than twice as much palmitic acid as the 3-position. Statistically significant differences are found between normal and hyperlipemic humans for palmitic and linoleic acid at the 2-position, and for oleic and linoleic acid at the 3-position.

Bile acids and microflora were studied in the proximal jejunum in 31 patients with Billroth I or II gastrectomy. At least 10(5) bacteria/ml., most frequently aerobic or facultative aerobic organisms, were isolated in 25 patients. Deconjugation diminished considerably in only three of seven patients with bile salt deconjugation treated with clindamycin. The relationship between bacterial overgrowth, deconjugation, steatorrhea, cholesterolemia and the relationship between bile salt concentration after testmeal and steatorrhea, are discussed. Bacterial overgrowth and bile salt deconjugation are only minor causes of steatorrhea in this series.