scholarly journals Iron absorption during normal human pregnancy: a study using stable isotopes

1991 ◽  
Vol 65 (3) ◽  
pp. 457-463 ◽  
Author(s):  
Paul G. Whittaker ◽  
Tom Lind ◽  
John G. Williams
Keyword(s):  
Inductively Coupled Plasma ◽  
Iron Absorption ◽  
Argon Plasma ◽  
Normal Pregnancy ◽  
The Other ◽  
Inductively Coupled ◽  
Normal Limits ◽  
Plasma Mass Spectrometry ◽  
Normal Human ◽  
Haematological Indices

The absorption of iron has been determined in nine healthy women studied serially during pregnancy and once post delivery. Following the oral administration of 5 mg aqueous 54FeSO4 plus ascorbic acid and the intravenous injection of 200 μg 57FeSO4, the isotope ratios of 54Fe: 56Fe and 57Fe:56Fe in serum were measured by the use of inductively-coupled-plasma mass spectrometry whereby metal ions are vaporized into an argon plasma without previous blood sample preparation. Mean oral Fe absorption was 7.6 (range 1–22) % at 12 weeks gestation, 21.1 (range 9–58) % at 24 weeks, 37.4 (range 18–56) % at 36 weeks and 26.3 (range 8–54) % at 12 weeks post delivery. All the other biochemical and haematological indices were within normal limits for pregnancy. The significant increase (P < 0.01) in Fe absorption during normal pregnancy suggests that most women would have the potential to meet the Fe demands of pregnancy without the need for supplementation if dietary Fe has similar availability to the aqueous preparation.

Comparison of Stable Isotopes and Radioisotopes in the Measurement of Iron Absorption in Healthy Women

1994 ◽  
Vol 87 (1) ◽  
pp. 91-95 ◽  
Author(s):  
Jon F. R. Barrett ◽  
Paul G Whittaker ◽  
John D. Fenwick ◽  
John G. Williams ◽  
Tom Lind
Keyword(s):  
Mass Spectrometry ◽  
Stable Isotopes ◽  
Inductively Coupled Plasma ◽  
Iron Absorption ◽  
Whole Body ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry ◽  
Body Counting ◽  
The Mean ◽  
Whole Body Counting

1. Stable isotope methods are being used to investigate the absorption of dietary iron. In order to be certain that this new methodology is accurate, we have compared results obtained using stable isotopes and inductively coupled plasma mass spectrometry with those determined using a radioisotope and whole body counting. 2. The stable isotope 54Fe (2.8 mg) was given to 10 healthy non-pregnant women. Six women received the isotope in aqueous form, and four took it with a meat meal. The 54Fe served as a carrier for 10 ng of the radioisotope 59Fe. An ampoule (200 μg) of the isotope 57Fe or 58Fe was then given intravenously, and in serum samples taken over the next 10 h the ratios of the stable iron isotopes were measured by inductively coupled plasma mass spectrometry and the oral iron absorption was calculated. This was then compared with the results obtained by using a whole body counter to measure (on day 0 and day 14) the γ-activity emitted by the radioisotope. 3. The mean iron absorption measured by both methods ranged from 8% to 45%. Measurement of the post-absorptive serum enrichment of the stable isotopes provided estimates of absorption from both aqueous and food iron which were similar to that yielded by whole body counting, the mean difference being −1.5% (95% confidence interval −5.2 to 2.1%). Absorption estimated by stable isotopes exhibited the same inverse relationship with the serum ferritin level (body iron stores) to that known to exist with whole body counting. Similar estimates of food iron absorption were obtained irrespective of the type of isotope used as an extrinsic label, implying that stable isotopes are as valid as radioisotopes in reflecting intrinsic food iron absorption. 4. This study validates the use of stable isotopes and post-absorption curves as a new and accurate technique in the measurement of iron absorption.

scholarly journals A culture-based calibration of benthic foraminiferal paleotemperature proxies: δ<sup>18</sup>O and Mg/Ca results

2010 ◽  
Vol 7 (4) ◽  
pp. 1335-1347 ◽  
Author(s):  
H. L. Filipsson ◽  
J. M. Bernhard ◽  
S. A. Lincoln ◽  
D. C. McCorkle
Keyword(s):  
Mass Spectrometry ◽  
Laser Ablation ◽  
Temperature Dependence ◽  
Benthic Foraminifera ◽  
Inductively Coupled Plasma ◽  
The Other ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry ◽  
Predicted Values ◽  
Increasing Temperature

Abstract. Benthic foraminifera were cultured for five months at four temperatures (4, 7, 14 and 21 °C) to establish the temperature dependence of foraminiferal calcite δ18O and Mg/Ca. Two Bulimina species (B. aculeata and B. marginata) were most successful in terms of calcification, adding chambers at all four temperatures and reproducing at 7 and 14 °C. Foraminiferal δ18O values displayed ontogenetic variations, with lower values in younger individuals. The δ18O values of adult specimens decreased with increasing temperature in all but the 4 °C treatment, exhibiting a relationship consistent with previous δ18O paleotemperature calibration studies. Foraminiferal Mg/Ca values, determined by laser ablation inductively coupled plasma mass spectrometry, were broadly consistent with previous Mg/Ca calibration studies, but extremely high values in the 4 °C treatment and higher than predicted values at two of the other three temperatures make it challenging to interpret these results.

scholarly journals Susceptibility of Enamel Treated with Bleaching Agents to Mineral Loss after Cariogenic Challenge

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Hüseyin Tezel ◽  
Cigdem Atalayin ◽  
Ozlem Erturk ◽  
Ercument Karasulu
Keyword(s):  
Hydrogen Peroxide ◽  
Inductively Coupled Plasma ◽  
The Other ◽  
Clinical Aspects ◽  
Control Group ◽  
Carbamide Peroxide ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry ◽  
And Control ◽  
Calcium Loss

Objectives. Controversial reports exist whether bleaching agents cause a susceptibility to demineralization. The aim of this study was to compare the calcium loss of enamel treated with different bleaching agents and activation methods.Method and Materials. The specimens obtained from human premolars were treated in accordance with manufacturer protocols; 10% carbamide peroxide, 38% hydrogen peroxide light-activated, 38% hydrogen peroxide laser-activated, and no treatment (control). After cariogenic challenge calcium concentrations were determined by Inductively Coupled Plasma Mass Spectrometry.Results. No differences were found between the calcium loss of the laser-activated group and 10% carbamide peroxide group (). However, the differences between laser-activated and control groups were statistically significant (). The differences between 10% carbamide peroxide and the control group were not significant (). On the other hand, the light-activated group showed a significantly higher calcium loss compared with the other groups ().Conclusions. The results show that bleaching agents may cause calcium loss but it seems to be a negligible quantity for clinical aspects.

scholarly journals A culture-based calibration of benthic foraminiferal paleotemperature proxies: δ<sup>18</sup>O and Mg/Ca results

2010 ◽  
Vol 7 (1) ◽  
pp. 351-385 ◽  
Author(s):  
H. L. Filipsson ◽  
J. M. Bernhard ◽  
S. A. Lincoln ◽  
D. C. McCorkle
Keyword(s):  
Mass Spectrometry ◽  
Laser Ablation ◽  
Temperature Dependence ◽  
Benthic Foraminifera ◽  
Inductively Coupled Plasma ◽  
The Other ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry ◽  
Expected Values ◽  
Increasing Temperature

Abstract. Benthic foraminifera were cultured for five months at four temperatures (4, 7, 14 and 21 °C) to establish the temperature dependence of foraminiferal δ18O and Mg/Ca. Two Bulimina species (B. aculeata and B. marginata) were most successful, adding chambers at all four temperatures and reproducing at 7 and 14 °C. Foraminiferal δ18O values displayed ontogenetic variations, with lower values in younger individuals. The δ18O values of adult specimens decreased with increasing temperature in all but the 4 °C treatment, exhibiting a relationship consistent with previous δ18O paleotemperature calibration studies. Foraminiferal Mg/Ca values, determined by laser ablation inductively coupled plasma mass spectrometry, were broadly consistent with previous Mg/Ca calibration studies, but extremely high values in the 4 °C treatment and higher than expected values at two of the other three temperatures make it challenging to interpret these results.

Ingestion of trace metals by the opossum shrimp, Mysis relicta, determined by laser ablation sampling - inductively coupled plasma mass spectrometry

1998 ◽  
Vol 76 (8) ◽  
pp. 1605-1610 ◽  
Author(s):  
David C Lasenby ◽  
Geoff Veinott
Keyword(s):  
Mass Spectrometry ◽  
Laser Ablation ◽  
Trace Metals ◽  
Inductively Coupled Plasma ◽  
The Other ◽  
Gut Contents ◽  
Mysis Relicta ◽  
Inductively Coupled ◽  
Opossum Shrimp ◽  
Plasma Mass Spectrometry

Differences in the diet of individual mysids can be determined by analysing the elemental composition of the gut contents of individual mysids with laser ablation sampling - inductively coupled plasma mass spectrometry. Two groups of the opossum shrimp, Mysis relicta, were cultured in the laboratory for a 2-week period. One group was fed a diet of Daphnia magna and the other lake sediment. Although the element:Sr ratios within the gut were highly variable, mean element:Sr ratios of several elements (V, Pb, Ca) in the gut of mysids fed D. magna were significantly different from those in the gut of sediment-fed mysids.

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