scholarly journals 14C-Cobalamin Absorption from Endogenously Labeled Chicken Eggs Assessed in Humans Using Accelerator Mass Spectrometry

Nutrients ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 2148 ◽  
Author(s):  
Garrod ◽  
Rossow ◽  
Calvert ◽  
Miller ◽  
Green ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Human Volunteers ◽  
Physiological Limit ◽  
Stool Samples ◽  
Vitamin B 12 ◽  
Chicken Eggs ◽  
Higher Doses ◽  
Cobalamin Absorption

Traditionally, the bioavailability of vitamin B-12 (B12) from in vivo labeled foods was determined by labeling the vitamin with radiocobalt (57Co, 58Co or 60Co). This required use of penetrating radioactivity and sometimes used higher doses of B12 than the physiological limit of B12 absorption. The aim of this study was to determine the bioavailability and absorbed B12 from chicken eggs endogenously labeled with 14C-B12 using accelerator mass spectrometry (AMS). 14C-B12 was injected intramuscularly into hens to produce eggs enriched in vivo with the 14C labeled vitamin. The eggs, which provided 1.4 to 2.6 μg of B12 (~1.1 kBq) per serving, were scrambled, cooked and fed to 10 human volunteers. Baseline and post-ingestion blood, urine and stool samples were collected over a one-week period and assessed for 14C-B12 content using AMS. Bioavailability ranged from 13.2 to 57.7% (mean 30.2 ± 16.4%). Difference among subjects was explained by dose of B12, with percent bioavailability from 2.6 μg only half that from 1.4 μg. The total amount of B12 absorbed was limited to 0.5–0.8 μg (mean 0.55 ± 0.19 μg B12) and was relatively unaffected by the amount consumed. The use of 14C-B12 offers the only currently available method for quantifying B12 absorption in humans, including food cobalamin absorption. An egg is confirmed as a good source of B12, supplying approximately 20% of the average adult daily requirement (RDA for adults = 2.4 μg/day).

scholarly journals Histone Adduction with Nicotine: A Bio-Ams Study

Radiocarbon ◽  
1997 ◽  
Vol 39 (3) ◽  
pp. 293-297 ◽  
Author(s):  
X. H. Wu ◽  
H. F. Wang ◽  
Y. F. Liu ◽  
X. Y. Lu ◽  
J. J. Wang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Human Exposure ◽  
Mouse Liver ◽  
Dose Range ◽  
The Other ◽  
Histone 3 ◽  
Protein Adduction ◽  
Dna Adduction

Based on the study of DNA adduction with nicotine, we have measured the mouse hepatic histone adduction with 14C-labeled nicotine in vivo by bio-accelerator mass spectrometry (bio-AMS). In the exposure of mice to nicotine, the dose range administered was from 0.2 μg to 6.0 μg kg b.w.-1, which was equivalent to a very low level of human exposure to cigarette smoke. The adducts of either histone 1 (H1) or histone 3 (H3) with nicotine in mouse liver increased markedly with increasing nicotine dose. Our results have demonstrated that in the study of protein adduction with toxic xenobiotics as a biomarker, the AMS method achieves the highest sensitivity, 4.6 × 10-17 mol (46 amol) adducts per mg H1 protein, compared to all the other methods used previously.

scholarly journals Determining the Pharmacokinetics and Long-Term Biodistribution of SiO2 Nanoparticles In Vivo Using Accelerator Mass Spectrometry

Nano Letters ◽  
2012 ◽  
Vol 12 (11) ◽  
pp. 5532-5538 ◽  
Author(s):  
Michael A. Malfatti ◽  
Heather A. Palko ◽  
Edward A. Kuhn ◽  
Kenneth W. Turteltaub
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Sio2 Nanoparticles

scholarly journals 41Ca and Accelerator Mass Spectrometry to Monitor Calcium Metabolism in End Stage Renal Disease Patients

2005 ◽  
Vol 51 (11) ◽  
pp. 2095-2102 ◽  
Author(s):  
Robert L Fitzgerald ◽  
Darren J Hillegonds ◽  
Douglas W Burton ◽  
Terrance L Griffin ◽  
Scott Mullaney ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Bone Resorption ◽  
Renal Disease ◽  
Accelerator Mass Spectrometry ◽  
End Stage Renal Disease ◽  
Isotope Ratios ◽  
Stage Renal Disease ◽  
End Stage ◽  
Esrd Patients

Abstract Background: Monitoring bone resorption with measurements of bone density and biochemical markers is indirect. We hypothesized that bone resorption can be studied directly by serial measurements of the ratio 41Ca/Ca in serum after in vivo labeling of calcium pools with 41Ca. We report the preparation of an intravenous 41Ca dose suitable for humans, an analytical method for determining 41Ca/Ca isotope ratios in biological samples, and studies in human volunteers. Methods: 41Ca was formulated and aliquoted into individual vials, and to the extent possible, the 41Ca doses were tested according to US Pharmacopeia (USP) guidelines. A 10 nCi dose of 41Ca was administered intravenously to 4 end stage renal disease (ESRD) patients on hemodialysis and 4 healthy control individuals. Distribution kinetics were determined over 168 days. Calcium was isolated with 3 precipitation steps and a cation-exchange column, and 41Ca/Ca ratios in serum were then measured by accelerator mass spectrometry. Results: The dosing solution was chemically and radiologically pure, contained <0.1 endotoxin unit/mL, and passed USP sterility tests. Quantification of 41Ca/Ca ratios was linear from 6 × 10−14 to 9.1 × 10−10. The run-to-run imprecision (as CV) of the method was 4% at 4.6 × 10−11 and 6% at 9.1 × 10−10. The area under the curve of 41Ca in the central compartment vs time was significantly less for ESRD patients than for controls (P <0.005). Conclusions: Isotope ratios spanning 5 orders of magnitude can be measured by accelerator mass spectrometry with excellent precision in the range observed in samples collected from patients who have received 10 nCi of 41Ca. The 41Ca at this dose caused no adverse effects in 8 volunteers. This is the first report of the use of 41Ca to monitor differences in bone turnover between healthy individuals and ESRD patients.

scholarly journals Zone analysis by two-dimensional electrophoresis with accelerator mass spectrometry of in vivo protein bindings of idiosyncratic hepatotoxicants troglitazone and flutamide bioactivated in chimeric mice with humanized liver

2015 ◽  
Vol 4 (1) ◽  
pp. 106-111 ◽  
Author(s):  
Hiroshi Yamazaki ◽  
Shunji Kuribayashi ◽  
Tae Inoue ◽  
Tomohiro Honda ◽  
Chise Tateno ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Two Dimensional ◽  
Chimeric Mice ◽  
Two Dimensional Electrophoresis ◽  
Dimensional Electrophoresis

A zone analysis for imbalance of covalent bindings of substrates and proteins may help predict hepatoxicity.

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