Disposition of 14C-erythritol in germfree and conventional rats.

The metabolism and disposition of U-14C-erythritol was examined in four groups of three male and three female, nonfasted rats each. The rats of groups A and D were germfree; the rats of groups B and C were kept under conventional conditions. The rats of group B received an erythritol-supplemented diet for 3 weeks prior to the experiment (adapted rats).

Catch Handling and the Possible Migration of Anisakis Larvae in Herring, Clupea harengus.

The behavior of larvae of Anisakis sp. in North Sea herring (Clupea harengus) after capture was examined by a sensitive quantitative method (digestion). In one winter and one summer experiment, the mean numbers of worms in freshly caught herring were 0.

Bioanalysis of erythromycin 2'-ethylsuccinate in plasma using phase-system switching continuous-flow fast atom bombardment liquid chromatography-mass spectrometry.

A specific method for the determination of erythromycin 2'-ethylsuccinate (EM-ES) in plasma is described. The method involves a liquid-liquid extraction procedure followed by the analysis of extracts using phase-system switching (PSS) continuous-flow fast atom bombardment (CF-FAB) liquid chromatography-mass spectrometry (LC-MS). In PSS EM-ES is enriched after analytical separation on a short trapping column, from which it is desorbed to the LC-MS interface.

Occurrence and formation of biologically active amines in foods.

Attention is given to the toxicology of biogenic amines and their occurrence and formation in foods, with special emphasis on fermented foods. The role of the associated flora, the starter cultures used and their interaction is discussed.

Polycyclic aromatic hydrocarbons in Dutch total diet samples (1984-1986).

Over a period of 2.5 yr, 221 different food items of a 'market basket' of 18-yr-old males were purchased every 3 months. In total, 10 market baskets were collected.

Characterization of virus infected cell cultures by pyrolysis/direct chemical ionization mass spectrometry.

The supernatants of Vero cell cultures after infection with a herpes simplex virus or a poliomyelitis virus as well as a blank were analysed by pyrolysis/direct chemical ionization mass spectrometry (Py/DCI MS). Informative pyrogrammes were obtained and used for characterization of viral proteins by applying pattern recognition methods. Differentiation of viral proteins was evaluated by analysing 'blind' samples.

Identification of diuron and four of its metabolites in human postmortem plasma and urine by LC/MS with a moving-belt interface.

Unknown compounds that were not amenable to GC/MS were found during routine benzodiazepine HPLC screening in a postmortem case. The apparent thermolability made the application of liquid chromatography with mass spectrometry mandatory. The moving-belt interface was used because of its value for identification based on the use of both electron impact and chemical ionization, which provided information on both structure and molecular weight.

Direct chemical ionization-mass spectrometric profiling of urine in premenstrual syndrome.

In search of the pathophysiological background of premenstrual syndrome, direct chemical ionization-mass spectrometric profiling was applied to urine samples from 17 patients and 18 control subjects, collected on days 11 and 25 of the menstrual cycle. Oestrogenic compounds and hippuric acid were found to be involved in differences between these groups. Quotient profiles calculated for each subject from their profiles of days 11 and 25 showed cycle day-dependent group differences.

The effect of processing conditions on glucosinolates in cruciferous vegetables.

Glucosinolates are found naturally in cruciferous plants, such as brassica vegetables, which are important in the human diet. Glucosinolates are readily converted into a range of physiologically active compounds by hydrolysis under the influence of an endogenous thioglucosidase, which becomes active when plant cells are disrupted. Cruciferous vegetables are eaten raw, they are also consumed in the processed form.

Direct chemical ionization-pattern recognition: characterization of bacteria and body fluid profiling.

Direct chemical ionization is ideally suited for profiling purposes because it is a relatively soft ionization method, easy to operate, reproducible and with a high sample throughput. Moreover, for non-volatile matrices the method combines pyrolysis with an optimal pyrolysate transfer to the ionization region enabling the detection of high molecular weight compounds. Application of the technique to urine analysis of women with a premenstrual syndrome and characterization of Salmonella bacteria illustrates its usefulness.

Effect of dietary calcium supplementation with lactose on bone in vitamin D-deficient rats.

The relationship between plasma calcium and bone length, chemical and histomorphometric bone parameters was studied in vitamin D-deficient rats in order to determine whether the effects of vitamin D on bone could be attributed to the effect of vitamin D on serum calcium. Plasma calcium was varied over a wide range of dietary manipulation. Four groups of vitamin D-deficient rats were given for 6 weeks: a vitamin D-deficient diet (D-, n = 6), the D--diet with calcium supplementation (D-Ca+, n = 6), the D-Ca+-diet with lactose substituted for dextrose (D-Ca+lac, n = 6) or a normal diet (D+, n = 8).