Direct metabolites of Ethanol as biological markers of alcohol use: Basic aspects and applications

In addition to self reports and questionnaires, biomarkers are of relevance in the diagnosis of and therapy for alcohol use disorders. Traditional biomarkers such as gamma-glutamyl transpeptidase or mean corpuscular volume are indirect biomarkers and are subject to the influence of age, gender and non-alcohol related diseases, among others. Direct metabolites of ethanol such as Ethyl glucuronide (EtG), ethyl sulphate (EtS) and phosphatidylethanol (PEth) are direct metabolites of ethanol, that are positive after intake of ethyl alcohol. They represent useful diagnostic tools for identifying alcohol use even more accurately than traditional biomarkers. Each of these drinking indicators remains positive in serum and urine for a characteristic time spectrum after the cessation of ethanol intake - EtG and EtS in urine up to 7 days, EtG in hair for months after ethanol has left the body. Applications include clinical routine use, emergency room settings, proof of abstinence in alcohol rehabilitation programmes, driving under influence offenders, workplace testing, assessment of alcohol intake in the context of liver transplantation and foetal alcohol syndrome. Due to their properties, they open up new perspectives for prevention, interdisciplinary cooperation, diagnosis of and therapy for alcohol-related problems.

What Ethanol metabolites as biological markers tell us about alcohol use

Alcohol and tobacco related disorders are the two leading and most expensive causes of illness in central Europe. In addition to self reports and questionnaires, biomarkers are of relevance in diagnosis and therapy of alcohol use disorders.Traditional biomarkers such as gamma glutamyl transpeptidase or mean corpuscualr volume are indirect biomarkers and are subject to influence of age, gender and non alcohol related diseases, among others.Direct ethanol metabolites such as ethyl glucuronide (EtG), ethyl sulphate (EtS) and phosphatidylethanol (PEth) are direct metabolites of ethanol, that are positive after intake of ethyl alcohol. They represent useful diagnostic tools for identifying alcohol use even more accurately than traditional biomarkers. Each of these drinking indicators remains positive in serum and urine for a characteristic time spectrum after the cessation of ethanol intake-EtG and EtS in urine up to 7 days, EtG in hair for months after ethanol has left the body. Applications include clinical routine use, emergency room settings, proof of abstinence in alcohol rehabilitation programs, driving under influence offenders, workplace testing, assessment of alcohol intake in the context of liver transplantation and fetal alcohol syndrome.

Design and operation of ARGONTUBE: a 5 m long drift liquid argon TPC

The Liquid Argon Time Projection Chamber (LArTPC) is a prime type of detector for future large-mass neutrino observatories and proton decay searches. In this paper we present the design and operation, as well as experimental results from ARGONTUBE, a LArTPC being operated at the AEC-LHEP, University of Bern. The main goal of this detector is to prove the feasibility of charge drift over very long distances in liquid argon. Many other aspects of the LArTPC technology are also investigated, such as a voltage multiplier to generate high voltage in liquid argon (Greinacher circuit), a cryogenic purification system and the application of multi-photon ionization of liquid argon by a UV laser. For the first time, tracks induced by cosmic muons and UVlaser beam pulses have been observed and studied at drift distances of up to 5 m, the longest reached to date.

First measurements with ARGONTUBE, a 5m long drift Liquid Argon TPC

The Liquid Argon Time Projection Chamber (LAr TPC) technique is a promising technology for future neutrino detectors. At LHEP of the University of Bern (Switzerland), an R&D program towards large detectors are on-going. The main goal is to show the feasibility of long drift paths over many meters. Therefore, a liquid Argon TPC with 5m of drift distance was constructed. Many other aspects of the liquid Argon TPC technology are also investigated, such as a new device to generate high voltage in liquid Argon (Greinacher circuit), a recirculation filtering system and the multi-photon ionization of liquid Argon with a UV laser. Two detectors are built: a medium size prototype for specific detector technology studies, and ARGONTUBE, a 5m long device.

Comparison of globules prepared from high dilutions of various starting materials by ultraviolet light spectroscopy

Background: High and ultra-high dilutions of various starting materials, e.g. copper sulfate, Hypericum perforatum and sulfur, showed significant differences in ultraviolet light (UV) transmission from controls and amongst different dilution levels [1,2]. Verum and placebo globules of Aconitum napellus 30c or calcium carbonate/quercus e cortice 6x from the same packs as used in previous clinical trials and dissolved in water could be distinguished by UV spectroscopy [3]. However, it was unclear whether the differences in UV absorbance originated from specific characteristics of the starting materials, from differences in the production of verum and placebo globules, and/or other unknown interference factors. Aims: The aim of this study was to investigate whether globules produced with high and ultra-high dilutions (6x, 12x, 30c, 200c, 200CF (centesimal discontinuous fluxion), 10,000CF) of various starting materials (Aconitum napellus, Atropa belladonna, phosphorus, sulfur, Apis mellifica, quartz) could be distinguished by UV spectroscopy. Methodology: The globules were specially produced for this study by Spagyros AG (Gümligen, Switzerland) and differed only in the starting materials of the dilutions (but not in the batch of globules or ethanol used). Globules were dissolved in water at 10 mg/ml, in quadruplicates, approximately 22 h prior to the measurements. Absorbance of the samples in the UV range (from 190 to 340 nm) was measured in a randomized order with a Shimadzu double beam UV-1800 spectrophotometer equipped with an auto sampler. Samples of each starting material were prepared and measured on 5 independent days. The daily variations of the spectrophotometer as well as the drift during the measurements were corrected for. The average absorbance from 200 to 340 nm was compared among various starting materials within equal dilution levels using a Kruskal-Wallis test. Results: Statistically significant differences were found among 30c (Figure 1), 200c and 200CF dilutions of the various starting materials. No differences were found among 6x, 12x and 10,000CF dilutions. Conclusions: Globules prepared from high dilutions of various starting materials may show significantly different UV absorbance when dissolved in water. References [1] Wolf U, Wolf M, Heusser P, Thurneysen A, Baumgartner S. Homeopathic preparations of quartz, sulfur and copper sulfate assessed by UV-spectroscopy. Evid Based Complement Alternat Med. 2011;2011:692798. [2] Klein SD, Sandig A, Baumgartner S, Wolf U. Differences in median ultraviolet light transmissions of serial homeopathic dilutions of copper sulfate, Hypericum perforatum, and sulfur. Evid Based Complement Alternat Med. 2013;2013:370609. [3] Klein SD, Wolf U. Investigating homeopathic verum and placebo globules with ultraviolet spectroscopy. Forsch Komplementmed. 2013, accepted.

Measurement of the drift field in the ARGONTUBE LAr TPC with 266 nm pulsed laser beams

ARGONTUBE is a liquid argon time projection chamber (LAr TPC) with a drift field generated in-situ by a Greinacher voltage multiplier circuit. We present results on the measurement of the drift-field distribution inside ARGONTUBE using straight ionization tracks generated by an intense UV laser beam. Our analysis is based on a simplified model of the charging of a multi-stage Greinacher circuit to describe the voltages on the field cage rings.

Ethanol Metabolites: Their Role in the Assessment of Alcohol Intake

BACKGROUND Alcohol-related disorders are common, expensive in their course, and often underdiagnosed. To facilitate early diagnosis and therapy of alcohol-related disorders and to prevent later complications, questionnaires and biomarkers are useful. METHODS Indirect state markers like gamma-glutamyl-transpeptidase, mean corpuscular volume, and carbohydrate deficient transferrin are influenced by age, gender, various substances, and nonalcohol-related illnesses, and do not cover the entire timeline for alcohol consumption. Ethanol (EtOH) metabolites, such as ethyl glucuronide, ethyl sulfate, phosphatidylethanol, and fatty acid ethyl esters have gained enormous interest in the last decades as they are detectable after EtOH intake. RESULTS For each biomarker, pharmacological characteristics, detection methods in different body tissues, sensitivity/specificity values, cutoff values, time frames of detection, and general limitations are presented. Another focus of the review is the use of the markers in special clinical and forensic samples. CONCLUSIONS Depending on the biological material used for analysis, ethanol metabolites can be applied in different settings such as assessment of alcohol intake, screening, prevention, diagnosis, and therapy of alcohol use disorders.

Determination of fatty acid ethyl esters in dried blood spots by LC-MS/MS as markers for ethanol intake: application in a drinking study.

The forensic utility of fatty acid ethyl esters (FAEEs) in dried blood spots (DBS) as short-term confirmatory markers for ethanol intake was examined. An LC-MS/MS method for the determination of FAEEs in DBS was developed and validated to investigate FAEE formation and elimination in a drinking study, whereby eight subjects ingested 0.66-0.84 g/kg alcohol to reach blood alcohol concentrations (BAC) of 0.8 g/kg. Blood was taken every 1.5-2 h, BAC was determined, and dried blood spots were prepared, with 50 μL of blood, for the determination of FAEEs. Lower limits of quantitation (LLOQ) were between 15 and 37 ng/mL for the four major FAEEs. Validation data are presented in detail. In the drinking study, ethyl palmitate and ethyl oleate proved to be the two most suitable markers for FAEE determination. Maximum FAEE concentrations were reached in samples taken 2 or 4 h after the start of drinking. The following mean peak concentrations (c̅ max) were reached: ethyl myristate 14 ± 4 ng/mL, ethyl palmitate 144 ± 35 ng/mL, ethyl oleate 125 ± 55 ng/mL, ethyl stearate 71 ± 21 ng/mL, total FAEEs 344 ± 91 ng/mL. Detectability of FAEEs was found to be on the same time scale as BAC. In liquid blood samples containing ethanol, FAEE concentrations increase post-sampling. This study shows that the use of DBS fixation prevents additional FAEE formation in blood samples containing ethanol. Positive FAEE results obtained by DBS analysis can be used as evidence for the presence of ethanol in the original blood sample. Graphical Abstract Time courses for fatty acid ethyl ester (FAEE) concentrations in DBS and ethanol concentrations for subject 1 over a period of 7 h. Ethanol ingestion occured during the first hour of the time course.