Proof‐of‐concept study on the suitability of <sup>13</sup>C‐urea as a marker substance for assessment of <i>in vivo</i> behaviour of oral colon‐targeted dosage forms

Schellekens, Reinout C. A.; Olsder, G G; Langenberg, S M C H; Boer, Th. J. de; Woerdenbag, Herman J.; Frijlink, Henderik W.; Kosterink, Jos G. W.; Stellaard, Frans

doi:10.1111/j.1476-5381.2009.00302.x

Cited by 20 publications

(13 citation statements)

References 29 publications

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“…[247] Relative bioavailability is used to compare different formulations of the same compound (e.g., capsule vs.tablet) [248] or to compare ageneric version with the original drug. [249] Absolute bioavailability is determined by comparing the blood (plasma) concentration-time curves (usually as "area under the curve") following extravascular drug and concomitant intravenous stable-isotope-labelled tracer administration (Scheme 24). [250] With the sensitivity improvements of newer mass spectrometry instruments into the picomolar or even femtomolar range,s table-isotope i.v.…”

Section: Stable Isotopes In Metabolomicsmentioning

confidence: 99%

Deuterium‐ and Tritium‐Labelled Compounds: Applications in the Life Sciences

Atzrodt¹,

Derdau²,

et al. 2018

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Hydrogen isotopes are unique tools for identifying and understanding biological and chemical processes. Hydrogen isotope labelling allows for the traceless and direct incorporation of an additional mass or radioactive tag into an organic molecule with almost no changes in its chemical structure, physical properties, or biological activity. Using deuterium-labelled isotopologues to study the unique mass-spectrometric patterns generated from mixtures of biologically relevant molecules drastically simplifies analysis. Such methods are now providing unprecedented levels of insight in a wide and continuously growing range of applications in the life sciences and beyond. Tritium ( H), in particular, has seen an increase in utilization, especially in pharmaceutical drug discovery. The efforts and costs associated with the synthesis of labelled compounds are more than compensated for by the enhanced molecular sensitivity during analysis and the high reliability of the data obtained. In this Review, advances in the application of hydrogen isotopes in the life sciences are described.

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Section: Stable Isotopes In Metabolomicsmentioning

confidence: 99%

Deuterium‐ and Tritium‐Labelled Compounds: Applications in the Life Sciences

Atzrodt¹,

Derdau²,

et al. 2018

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“…For example, heavy carbon can be used as a tracer in biomedical applications, [1] in studies of ecosystem carbon cycling, [2] in geology, [3] and in atmospheric studies. [4] Natural fractionation processes involved in photosynthesis and plant and microbial respiration make δ 13 C especially suited to studies of ecosystem carbon cycling.…”

mentioning

confidence: 99%

Adaptation of continuous‐flow cavity ring‐down spectroscopy for batch analysis of δ¹³C of CO₂ and comparison with isotope ratio mass spectrometry

Berryman

Marshall

Rahn

et al. 2011

Rapid Comm Mass Spectrometry

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Measurements of δ(13)C in CO(2) have traditionally relied on samples stored in sealed vessels and subsequently analyzed using magnetic sector isotope ratio mass spectrometry (IRMS), an accurate but expensive and high-maintenance analytical method. Recent developments in optical spectroscopy have yielded instruments that can measure δ(13)CO(2) in continuous streams of air with precision and accuracy approaching those of IRMS, but at a fraction of the cost. However, continuous sampling is unsuited for certain applications, creating a need for conversion of these instruments for batch operation. Here, we present a flask (syringe) adaptor that allows the collection and storage of small aliquots (20-30 mL air) for injection into the cavity ring-down spectroscopy (CRDS) instrument. We demonstrate that the adaptor's precision is similar to that of traditional IRMS (standard deviation of 0.3‰ for 385 ppm CO(2) standard gas). In addition, the concentration precision (±0.3% of sample concentration) was higher for CRDS than for IRMS (±7% of sample concentration). Using the adaptor in conjunction with CRDS, we sampled soil chambers and found that soil-respired δ(13)C varied between two different locations in a piñon-juniper woodland. In a second experiment, we found no significant discrimination between the respiration of a small beetle (~5 mm) and its diet. Our work shows that the CRDS system is flexible enough to be used for the analysis of batch samples as well as for continuous sampling. This flexibility broadens the range of applications for which CRDS has the potential to replace magnetic sector IRMS.

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“…First, after oral administration the concentrations of 13 C-urea reaching the lung are lower than those in the stomach and hence the amount of tracer available for bacterial conversion in the lung is limited. 13 C-urea uptake occurs rapidly once the tracer enters the jejunum, and earlier studies suggest that serum C max concentrations are achieved by 30–45 minutes after ingestion [26, 27]. Although our previous study in the rabbit model of TB produced a positive signal by both intra-tracheal administration [18] and oral administration (unpublished data), the anatomical and physiological parameters of oral administration may render it a poor model for studies such as this.…”

Section: Discussionmentioning

confidence: 91%

Stool microbiome reveals diverse bacterial ureases as confounders of oral urea breath testing for Helicobacter pylori and Mycobacterium tuberculosis in Bamako, Mali

et al. 2016

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Detection of bacterial urease activity has been utilized successfully to diagnose Helicobacter pylori (H. pylori). While Mycobacterium tuberculosis (M. tb) also possesses an active urease, it is unknown whether detection of mycobacterial urease activity by oral urease breath test (UBT) can be exploited as a rapid point of care biomarker for tuberculosis (TB) in humans. We enrolled 34 individuals newly diagnosed with pulmonary TB and 46 healthy subjects in Bamako, Mali and performed oral UBT, mycobacterial sputum culture and H. pylori testing. Oral UBT had a sensitivity and specificity (95% CI) of 70% (46–88%) and 11% (3–26%), respectively, to diagnose culture-confirmed M. tb disease among patients without H. pylori, and 100% sensitivity (69–100%) and 11% specificity (3–26%) to diagnose H. pylori among patients without pulmonary TB. Stool microbiome analysis of controls without TB or H. pylori but with positive oral UBT detected high levels of non-H. pylori urease producing organisms, which likely explains the low specificity of oral UBT in this setting and in other reports of oral UBT studies in Africa.

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Proof‐of‐concept study on the suitability of ¹³C‐urea as a marker substance for assessment of in vivo behaviour of oral colon‐targeted dosage forms

Cited by 20 publications

References 29 publications

Deuterium‐ and Tritium‐Labelled Compounds: Applications in the Life Sciences

Deuterium‐ and Tritium‐Labelled Compounds: Applications in the Life Sciences

Adaptation of continuous‐flow cavity ring‐down spectroscopy for batch analysis of δ¹³C of CO₂ and comparison with isotope ratio mass spectrometry

Stool microbiome reveals diverse bacterial ureases as confounders of oral urea breath testing for Helicobacter pylori and Mycobacterium tuberculosis in Bamako, Mali

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Proof‐of‐concept study on the suitability of 13C‐urea as a marker substance for assessment of in vivo behaviour of oral colon‐targeted dosage forms

Cited by 20 publications

References 29 publications

Deuterium‐ and Tritium‐Labelled Compounds: Applications in the Life Sciences

Deuterium‐ and Tritium‐Labelled Compounds: Applications in the Life Sciences

Adaptation of continuous‐flow cavity ring‐down spectroscopy for batch analysis of δ13C of CO2 and comparison with isotope ratio mass spectrometry

Stool microbiome reveals diverse bacterial ureases as confounders of oral urea breath testing for Helicobacter pylori and Mycobacterium tuberculosis in Bamako, Mali

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Product

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Proof‐of‐concept study on the suitability of ¹³C‐urea as a marker substance for assessment of in vivo behaviour of oral colon‐targeted dosage forms

Adaptation of continuous‐flow cavity ring‐down spectroscopy for batch analysis of δ¹³C of CO₂ and comparison with isotope ratio mass spectrometry