Quantitating Isotopic Molecular Labels with Accelerator Mass Spectrometry

Vogel, John S.; Love, Adam H.

doi:10.1016/s0076-6879(05)02013-6

Cited by 64 publications

(92 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Typical AMS measurement times were 3-5 min per sample, with a counting precision of 0.6-1.4% and a SD among 3-10 measurements of 1-3%. The 14 C/ 13 C ratios of the protein samples were normalized to measurements of four identically prepared standards of known isotope concentration (IAEA C-6, also known as ANU sucrose) and converted to units of femtograms TETS per microgram protein (47). Each experiment was performed in triplicate and repeated three times in determining the mean and SEs.…”

mentioning

confidence: 99%

GABA _A receptor target of tetramethylenedisulfotetramine

Zhao

Hwang

Buchholz³

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Significance Tetramethylenedisulfotetramine (TETS) is a feared chemical threat agent because of its high convulsant toxicity, ease of synthesis, and availability even though it is banned as a rodenticide. Earlier physiological evidence indicating action as a GABA receptor antagonist and inhibitor of [ 35 S]TBPS and [ 3 H]EBOB binding is confirmed here by radiosynthesis of [ 14 C]TETS and defining its binding site in rat brain membranes by accelerator mass spectrometry and toxicant specificity studies on inhibition of [ 14 C]TETS and [ 3 H]EBOB binding. TETS undergoes specific and unique polar interactions inside the 1′2′ ring pore region instead of the 2′,6′, and 9′ site for insecticides. This study helps define GABA A R sites for potential antidotes acting to prevent TETS binding or displace it from its binding site.

show abstract

mentioning

confidence: 99%

GABA _A receptor target of tetramethylenedisulfotetramine

Zhao

Hwang

Buchholz³

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…After thawing a stored biological sample (or directly after collecting a fresh sample), small aliquots (20 µl plasma, 100 µl urine, 5 mg wet tissue, 75 µl homogenized feces, etc) containing 0.5 -2 mg of carbon (Vogel & Love, 2005) are first placed into a 6 mm quartz sample tube ( Figure 1A). The biological samples are then evaporated to dryness and the Falcon tube is capped promptly and stored.…”

Section: Sample Dryingmentioning

confidence: 99%

“…However, tributyrin from different sources can differ in 14 C content (Table 2). Tributyrin with low 14 C is used to maintain a significant signal to background level, but the finite 14 C content provides an alert of unexpected 14 C-depleted carbon in the collected sample (Vogel & Love, 2005), which is not available from 14 C-free carrier. The difference in tributyrin 14 C levels between combustion in 6 mm quartz at 900°C for 2.5 hr (0.111 ± 0.025 Mod) and 6 mm borosilicate glass at 650 o C for 2 hr (0.118 ± 0.024 Mod) is not significant.…”

Section: Eq 1: Dried Biological Sample + Cuomentioning

confidence: 99%

See 1 more Smart Citation

How to Convert Biological Carbon Into Graphite for AMS

et al. 2006

View full text Add to dashboard Cite

Isotope tracer studies, particularly radiocarbon measurements, play a key role in biological, nutritional, and environmental research. Accelerator mass spectrometry (AMS) is now the most sensitive detection method for radiocarbon, but AMS is not widely used in kinetic studies of humans. Part of the reason is the expense, but costs would decrease if AMS were used more widely. One component in the cost is sample preparation for AMS. Biological and environmental samples are commonly reduced to graphite before they are analyzed by AMS. Improvements and mechanization of this multi-step procedure is slowed by a lack of organized educational materials for AMS sample preparation that would allow new investigators to work with the technique without a substantial outlay of time and effort. We present a detailed sample preparation protocol for graphitizing biological samples for AMS and include examples of nutrition studies that have used this procedure.

show abstract

“…1,3-6 First 14 C has a low natural abundance. Second, 14 C has a long half-life ( t 1/2 = 5,730 yrs).…”

Section: Introductionmentioning

confidence: 99%

Carbon Isotopes Profiles of Human Whole Blood, Plasma, Red Blood Cells, Urine and Feces for Biological/Biomedical ¹⁴C-Accelerator Mass Spectrometry Applications

et al. 2011

View full text Add to dashboard Cite

Radiocarbon (14C) is an ideal tracer for in vivo human ADME (absorption, distribution, metabolism, elimination) and PBPK (physiological-based pharmacokinetic) studies. Living plants preferentially incorporate atmospheric 14CO2, vs 13CO2, vs 12CO2, which result in unique signature. Furthermore, plants and the food chains they support also have unique carbon isotope signatures. Humans, at the top of the food chain, consequently acquire isotopic concentrations in the tissues and body fluids depending on their dietary habits. In preparation of ADME and PBPK studies, 12 healthy subjects were recruited. The human baseline (specific to each individual and their diet) total carbon (TC) and carbon isotope 13C (δ13C) and 14C (Fm) were quantified in whole blood (WB), plasma, washed red blood cell (RBC), urine, and feces. TC (mg of C/100μL) in WB, plasma, RBC, urine, and feces were 11.0, 4.37, 7.57, 0.53, and 1.90, respectively. TC in WB, RBC, and feces was higher in men over women, P < 0.05. Mean δ13C were ranked low to high as follows, feces < WB = plasma = RBC = urine, P < 0.0001. δ13C was not affected by gender. Our analytic method shifted δ13C by only ± 1.0 ‰ ensuring our Fm measurements were accurate and precise. Mean Fm were ranked low to high as follows, plasma = urine < WB = RBC = feces, P < 0.05. Fm in feces was higher for men over women, P < 0.05. Only in WB, 14C levels (Fm) and TC were correlated with one another (r = 0.746, P < 0.01). Considering the lag time to incorporate atmospheric 14C into plant foods (vegetarian) and or then into animal foods (non-vegetarian), the measured Fm of WB in our population (recruited April 2009) was 1.0468 ± 0.0022 (mean±SD), the Fm of WB matched the (extrapolated) atmospheric Fm of 1.0477 in 2008. This study is important in presenting a procedure to determine a baseline for a study group for human ADME and PBPK studies using 14C as a tracer.

show abstract

Quantitating Isotopic Molecular Labels with Accelerator Mass Spectrometry

Cited by 64 publications

References 29 publications

GABA _A receptor target of tetramethylenedisulfotetramine

GABA _A receptor target of tetramethylenedisulfotetramine

How to Convert Biological Carbon Into Graphite for AMS

Carbon Isotopes Profiles of Human Whole Blood, Plasma, Red Blood Cells, Urine and Feces for Biological/Biomedical ¹⁴C-Accelerator Mass Spectrometry Applications

Contact Info

Product

Resources

About

Quantitating Isotopic Molecular Labels with Accelerator Mass Spectrometry

Cited by 64 publications

References 29 publications

GABA A receptor target of tetramethylenedisulfotetramine

GABA A receptor target of tetramethylenedisulfotetramine

How to Convert Biological Carbon Into Graphite for AMS

Carbon Isotopes Profiles of Human Whole Blood, Plasma, Red Blood Cells, Urine and Feces for Biological/Biomedical 14C-Accelerator Mass Spectrometry Applications

Contact Info

Product

Resources

About

GABA _A receptor target of tetramethylenedisulfotetramine

GABA _A receptor target of tetramethylenedisulfotetramine

Carbon Isotopes Profiles of Human Whole Blood, Plasma, Red Blood Cells, Urine and Feces for Biological/Biomedical ¹⁴C-Accelerator Mass Spectrometry Applications