Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Iron Isotopes”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
PubMed2005

[ICP-MS with octopole reaction system applied to isotopic analysis of iron in human fecal samples].

OBJECTIVE: The study was aimed to evaluate the application of the quadrupole inductively coupled plasma mass spectrometer (ICP-MS) with collision/reaction cell octopole reaction system (ORS) to determine the iron stable isotope ratio in human fecal samples. METHODS: In a field trial on human metabolism, 3.0 mg per subject of iron with 57Fe enriched was orally administrated, and feces were collected by fecal monitoring. The isotope ratio of 57Fe to 56Fe in the prepared fecal sample was detected with the ORS-ICP-MS. RESULTS: With the application of ORS-ICP-MS, interferences from the Ar plasma and the calcium-contained polyatomic ions could be eliminated. When the sample solution properly diluted, interferences from the matrix were too little to be noted. The relative stand deviation (RSD) of the long-term and short-term precision was < 0.3 %. From the changes of 57 Fe/56 Fe in the daily samples, a regularity of fecal iron outputs was presented, and the fractional iron absorption could be evaluated. CONCLUSION: The ratio of 57 Fe to 56 Fe in the fecal sample could be accurately determined by the quadrupole ICP-MS with ORS, based on which the dietary iron absorption could be evaluated and the metabolism of iron in the human body could also be traced.

Feces↗
PubMedDate not supplied

An iron metabolism study in humans by means of stable tracers.

An investigation of iron metabolism in a female patient volunteer by administration of stable iron isotopes as tracers was performed. The applied methodology had already been tested in rabbits in comparison with radioactive tracer technique. The subject under study was given 58Fe solution intravenously and about 45 min later 57Fe solution orally. Ten blood samples were drawn at different times within 522 min from injection. Single iron isotopes content in plasma samples was determined by proton nuclear activation. A Compton suppressor system was utilized to improve the detector limits. The characteristic parameters of iron plasma clearance and of iron intestinal absorption were determined.

Activation Analysis↗
PubMed1998

Addition of rice cereal to formula does not impair mineral bioavailability.

BACKGROUND: The effect of adding rice cereal to formula on calcium and iron bioavailability was studied. METHODS: Fourteen healthy infants were studied at 2-week intervals to assess the absorption of calcium and iron from formula or formula mixed with rice cereal. Infants were randomly assigned to initiate the study either on a lactose-containing formula (F) or the same formula mixed with 6.5 g/dl of rice cereal (F + R). Calcium and iron absorption were determined using a multiple tracer approach in which calcium and iron isotopes were given orally mixed with either F or F + R and a different tracer of calcium given intravenously. Nine infants underwent calcium and iron studies and five underwent calcium studies only. A tracer amount of 46Ca was administered intravenously. Calcium absorption was determined as the ratio of the recovered oral versus intravenous tracer in the urine during the 24 hr after tracer administration. Iron incorporation into red blood cells (RBCs) was determined from the enrichment of the iron isotopes in the RBCs at 14 days after dosing. RESULTS: Mean (+/- SD) percent absorption of calcium from F was 58% (+/- 13) and from F + R 57% (+/- 18). Absorption of iron from F was 5.8% (+/- 7) and from F + R 6.3% (+/- 4) (p = 0.06). Analyses of variance for repeated measures indicated no significant correlation between amount of calories, calcium, or iron ingested, and calcium or iron absorbed. CONCLUSIONS: Adding rice cereal to formula does not impair bioavailability of calcium or iron from infant formulas. Because of the increased total calcium and iron in the mixture of formula and cereal, the overall amount of minerals absorbed from F + R may be greater than from formula alone.

Biological Availability↗
PubMed2005

Dietary and physiological factors that affect the absorption and bioavailability of iron.

Iron deficiency, a global health problem, impairs reproductive performance, cognitive development, and work capacity. One proposed strategy to address this problem is the improvement of dietary iron bioavailability. Knowledge of the molecular mechanisms of iron absorption is growing rapidly, with identification of mucosal iron transport and regulatory proteins. Both body iron status and dietary characteristics substantially influence iron absorption, with minimal interaction between these two factors. Iron availability can be regarded mainly as a characteristic of the diet, but comparisons between human studies of iron availability for absorption require normalization for the iron status of the subjects. The dietary characteristics that enhance or inhibit iron absorption from foods have been sensitively and quantitatively determined in human studies employing iron isotopes. People with low iron status can substantially increase their iron absorption from diets with moderate to high availability. But while iron supplementation and fortification trials can effectively increase blood indices of iron status, improvements in dietary availability alone have had minimal influence on such indices within several weeks or months. Plentiful, varied diets are the ultimate resolution to iron deficiency. Without these, more modest food-based approaches to human iron deficiency likely will need to be augmented by dietary iron fortification.

Biological Availability↗