Evaluation of a 24-Hour Caffeine Intake Assessment Compared with Urinary Biomarkers of Caffeine Intake among Young Adults in Canada.

Background: Caffeine is a widely consumed stimulant, and caffeine-containing products are increasingly available on the market. Few tools are available to capture caffeine intake, particularly among young adults. To estimate caffeine consumption in the previous 24 hours, the 24-Hour Caffeine Intake Recall (CIR-24) was modeled after the Automated Self-Administered 24-Hour Dietary Assessment Tool, using a brand-specific database of caffeine-containing foods, beverages, and supplements.

Urine excretion of caffeine and select caffeine metabolites is common in the U.S. population and associated with caffeine intake.

Background: Caffeine is a widely consumed psychoactive stimulant and is of epidemiologic interest. Major sources of caffeine are challenging to standardize, and the use of biomarkers is proposed as an alternative means of assessing intake.

Objective: We described urine caffeine and caffeine metabolite concentrations (n = 2466) and excretion rates (n = 2261) in the US population ≥6 y by age, sex, race-ethnicity, and caffeine intake (from foods, beverages, and dietary supplements).

Determination of urine caffeine and its metabolites by use of high-performance liquid chromatography-tandem mass spectrometry: estimating dietary caffeine exposure and metabolic phenotyping in population studies.

We have developed and validated a high-performance liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for determining urine caffeine and 14 caffeine metabolites suitable for estimating caffeine exposure and metabolic phenotyping in population studies. Sample preparation consisted solely of a series of simple reagent treatments at room temperature. Stable isotope-labeled analogs were used as internal standards for all analytes.

Detection and quantitation of subgroup C adenovirus DNA in human tissue samples by real-time PCR.

Advances in amplification techniques have revolutionized the ability to detect viruses both quantitatively and qualitatively and to study viral load. Real-time polymerase chain reaction (PCR) amplification depends on the ability to detect and quantify a fluorescent reporter molecule whose signal increases in proportion to the amount of amplification product generated. Recent advances have been made by using probes, such as TaqMan probes, to detect amplified products.