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Biomedical subjects

P Van Dael

Publications and source records attributed to P Van Dael.

12 recordsLinked to original sources
PubMed2001

Selenium absorption and retention from a selenite- or selenate-fortified milk-based formula in men measured by a stable-isotope technique.

The present study was designed to determine the apparent absorption and retention of the inorganic Se compounds SeO3(2-) and SeO4(2-), which are commonly used for Se fortification of clinical nutrition products and infant formulas. Ten healthy men were fed a milk-based formula labelled with 40 microg Se as 74SeO3(2-) or 76SeO4(2-) on two consecutive days using a randomised crossover design. Se stable-isotope analysis of 9 d complete collections of urine and faeces was used to calculate apparent Se absorption and retention. Se retention from 74SeO3(2-) (41.0 (SD 8.4) %) and from 76SeO4(2-) (46.0 (SD 7.9) %) was not significantly different (P > 0.05). However, Se absorption was significantly higher from SeO4(2-) than from SeO3(2-) (91.3 (SD 1.4) % v. 50.2 (SD 7.8) %, P < 0.05). Urinary excretion of the administered dose was 9.2 (SD 1.8) % for 74SeO3(2-) and 45.3 (SD 8.2) % for 76SeO4(2-) (P < 0.05). Urinary Se excretion kinetics differed significantly for the two Se compounds; 90 % of the total urinary Se was excreted after 121 h for 74SeO32- and after 40 h for 76SeO42- These results suggest that although Se absorption and urinary excretion differ for SeO3(2-) and SeO4(2-), both Se compounds are equally well retained when administered at a relatively low dose (40 microg Se). The nutritional impact of Se fortification of foods would thus be expected to be similar when SeO4(2-) or SeO3(2-) are used.

Adult↗
PubMed1998

Determination of selenium stable isotopes by gas chromatography-mass spectrometry with negative chemical ionisation.

A gas chromatography mass spectrometric method using negative chemical ionisation was developed for the determination of stable isotopes of selenium for evaluation of selenium absorption and retention from foods in humans. The method involves an acid digestion to convert all selenium into selenite, which subsequently reacts with 4-nitro-o-phenylene-diamine to form a volatile piazselenole. The piazselenole, after extraction into an organic solvent, was analysed for its isotopic selenium composition by gas chromatography mass spectrometry. Negative chemical ionisation is reported for the first time for the determination of selenium stable isotopes and its analytical characteristics were compared to those of electron impact mass spectrometric ionisation, classically used for the determination of selenium. The negative chemical ionisation technique allowed accurate determination of total selenium by isotope dilution and of selenium isotope ratios in biological samples. The repeatability for total selenium and for stable isotope ratios was good (R.S.D.< or =10%) within the range of 50 to 250 ng selenium. The detection limit for the investigated selenium isotopes was approximately 1 pg (signal to noise ratio at 3). The applicability of the developed stable isotope methodology was demonstrated by the determination of the selenium absorption and retention from foods in a pilot study using one human adult.

Adult↗
PubMed1996

Estimation of selenium bioavailability from human, cow's, goat and sheep milk by an in vitro method.

The trace element selenium (Se) has been recognized to be essential for human health. The dependence of infants on milk as their principal food source, generally low in Se content, makes them more vulnerable to inadequate Se intake. The present study compared the Se availability as estimated by a simulated gastrointestinal digestion procedure, of human milk and some common ruminant milks, namely cow, goat and sheep milk. The Se availability of human milk (11.1%) was significantly higher compared to that of cow (6.8%), goat (6.2%) and sheep milk ( < 2%). Further study suggested that the Se availability may be related to the gastric digestibility of protein. The high Se availability of human milk might be attributed to the high gastric digestibility of human milk protein. It was found that removal of the milk fat fraction increases the Se availability.

Animals↗
PubMed1994

Capillary whole blood selenium determination in assessing selenium status of children.

Selenium levels in venous and capillary whole blood of children were assessed by direct graphite furnace atomic absorption spectrometry. Selenium data obtained for both blood samples did not differ statistically (p > 0.05). Capillary blood may therefore be used as an alternative to venous blood, which is more difficult to obtain from children. Whole-blood selenium data for children in the Antwerp region (Belgium) were compared with literature data for children from other countries.

Belgium↗
PubMed1993

Selenium content of sheep's milk and its distribution in protein fractions.

The selenium (Se) distribution in sheep's milk is reported. Skim milk was found to contain the major part (98%) of total milk Se. The Se distribution over casein and whey protein fractions depends on the separation method used, but irrespective of these methods, skim milk Se is mainly associated with the casein fraction (> 68%). Approximately 11%, 4% and 17% Se is removed by dialysis (molecular mass cut-off 10-12 kDa) from skim milk, casein and whey respectively, indicating a major association of Se with milk proteins. This observation is confirmed through Se analysis of individual caseins and whey proteins isolated through ion-exchange chromatography and gel filtration. Se concentrations of the different isolated milk proteins show considerable variations (caseins, 304-750 ng Se/g; whey proteins, 241-806 ng Se/g).

Animals↗
PubMed1993

Evaluation of an in vitro method for the estimation of the selenium availability from cow's milk.

The present study evaluates the application of an in vitro digestion procedure for estimating the selenium (Se) availability from cow's milk. The results obtained by this in vitro method indicate that only a small portion (< 10%) of milk Se can be estimated as available. The available fraction of whole milk (4.7%) was significantly lower compared to the Se availability of skim milk (7.3%). Investigations on the methodology of the in vitro method indicate that the portion of total potentially available Se, determined as total dialysable Se, increases simultaneously with protein digestibility along with the digestion process. Therefore it is concluded that protein digestibility might largely influence the Se availability from milk.

Animals↗
PubMed1993

Selenium.

Explore the source record for details and available documents.

Blood Platelets↗
PubMed1992

Selenium content of goat milk and its distribution in protein fractions.

This study reports on selenium distribution in goat milk. Skim milk was found to contain the major part (94%) of total milk selenium. The selenium distribution over casein and whey protein fractions depends on the separation method used, but irrespective of these methods, skim milk selenium is mainly associated with the casein fraction (greater than 69%). Approximately 9%, 7% and 24% of selenium is removed by dialysis (molecular cutoff 10-12 kDa) from skim milk, casein and whey respectively, indicating a major association of selenium with milk proteins. This observation is confirmed by selenium analysis of individual caseins and whey proteins isolated through ion-exchange chromatography and gel filtration. Selenium concentrations of the different isolated milk proteins show considerable variation (caseins: 294-550 ng Se/g; whey proteins: 217-457 ng Se/g).

Animals↗
PubMed1990

Direct selenium determination in human whole blood by graphite furnace atomic absorption spectrometry with deuterium correction using a L'vov-platform, a Pd/Mg matrix modification and appropriate dilution.

A mixture of palladium/magnesium nitrate was used as matrix modifier in graphite furnace atomic absorption spectrometry for the direct determination of selenium in human whole blood Addition of HCl up to 0.2 M, a twenty-five fold diluted sample and an appropriate furnace program are necessary to eliminate the interference of iron. Reproducibility of less than 3% at the 95 micrograms/L level, a detection limit of 10 micrograms/L and good accuracy, as determined by intercomparison runs and recovery of spiked samples, are obtained. The proposed method can be used for analysing 4 blood samples per hour.

Deuterium↗
PubMedDate not supplied

Estimation of the bioavailability of zinc and calcium from human, cow's, goat, and sheep milk by an in vitro method.

The availability of zinc and calcium from human, cow's, goat, and sheep milk is evaluated by an in vitro method that involves a simulated human gastrointestinal digestion followed by measurement of dialyzability of zinc and calcium. Zinc availability of milk showed the highest value for human milk (15.0%) and the lowest for sheep milk (1.0%), in both whole and skim milk. Calcium availability of the different types of milk did not differ significantly and ranged between 18 and 23%. No significant differences in availability between whole and skim milk were found for both elements, except for zinc in cow's milk.

Animals↗