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A novel, simultaneous extraction of FAEE and EtG from meconium and analysis by LC-MS/MS
No full textatty acid ethyl esters (FAEEs) and ethyl-glucuronide (EtG) in meconium have been widely studied as biomarkers of maternal alcohol consumption during pregnancy. Many analytical approaches have been proposed for their analysis, mostly consisting of separated extraction procedures requiring the use of two meconium aliquots. This study aimed to validate a new analytical procedure for the simultaneous extraction of FAEEs and EtG from a meconium aliquot through a single solid-phase extraction (SPE) applied to 242 anonymized samples of meconium. Targeted FAEEs were: ethyl-myristate (Myr), ethyl-palmitate (Pal), ethyl-oleate (Ole) and ethyl-stearate (Ste). Two hundred milligrams of meconium was sonicated with acetonitrile, and a single SPE performed by means of aminopropyl columns. FAEEs were eluted with hexane, followed by EtG elution with water. Both the mixtures were dried, recovered, and analyzed by liquid chromatography-tandem mass spectrometry using C8 (FAEEs) and C18 (EtG) columns. Transitions were: m/z 257 → 57,88, Myr; m/z 262 → 57,88, Myr-d5; m/z 285 → 57, 72, Pal; m/z 290 → 57,258, Pal-d5; m/z 311 → 72,114, Ole; m/z 316 → 72,265, Ole-d5; m/z 257 → 57,72 Ste; m/z 318 → 57,286, Ste-d5; m/z 221 → 75,85, EtG; m/z 226 → 75,85, EtG-d5. Lower limit of quantification range was 10-15 ng/g for FAEEs and 10 ng/g for EtG. Linearity was evaluated for different concentration ranges; the mean coefficients of determination (R (2)) were above 0.9961. Precision and accuracy for FAEEs and EtG were consistently ≤20 % and ±20 %, respectively. Ion suppression was observed for all the analytes. Matrix effect did not significantly affect the analyses. Recovery efficiency was 93 % for EtG and 75-85 % for FAEEs
Assessing maternal alcohol consumption in pregnancy : comparison of confidential postnatal maternal interview and measurement of alcohol biomarkers in meconium
Get PDFObjective -- Knowledge of alcohol consumption in pregnancy is important for early identification of children with fetal alcohol spectrum disorder. We investigated whether alcohol biomarkers fatty acid ethyl esters (FAEEs) and ethyl glucuronide (EtG) in meconium are predicted by maternal or newborn demographics and/or correlate with confidential early postnatal self-report of alcohol consumption in pregnancy. Design -- Anonymised, observational population-based study. Setting -- Inner-city maternity unit, Glasgow, UK. Patients -- Singleton mother/infant dyads delivering every fourth day. Interventions -- Mother: confidential postnatal interview. Baby: meconium sample for FAEEs and EtG. Results -- 840/908 mothers consented. 370 (46.4%) reported alcohol consumption in pregnancy, generally of modest amount; for 114 (13.6%) this was after 20 weeks’ gestation. Alcohol consumption in later pregnancy was more commonly reported by older (31.3 vs 29.5 years) women of white British ethnicity (p Conclusions -- FAEEs and EtG measured in meconium have low sensitivity and specificity for self-reported alcohol consumption after 20 weeks’ gestation in an unselected Scottish population
Assessing maternal alcohol consumption in pregnancy : does phosphatidylethanol measured from day 5 newborn blood spot cards have any value? An observational, population-based study
Get PDFObjective: Prenatal alcohol exposure (PAE) places children at risk of fetal alcohol spectrum disorder (FASD) but ascertainment of PAE is problematic. Early intervention for children at risk of FASD may help mitigate long-term difficulties. Phosphatidylethanol (PEth), a metabolite of alcohol, is incorporated into red cell membranes and can be measured in dried blood spot (DBS) cards. In the UK, DBS samples are collected on day 5 for routine newborn screening. We sought to examine if PEth measured from DBS correlates with postnatal maternal self-report of alcohol consumption in pregnancy. Design: Observational population-based study. Comparison of infant PEth concentration and self-report of maternal alcohol use during pregnancy. Setting: Large maternity unit in Glasgow, Scotland. Participants: All singleton mother-infant dyads delivered during each fourth consecutive 24-hour period. Interventions: Mother: direct, confidential, immediate postnatal interview by a single researcher examining alcohol use during pregnancy. Infant: one extra DBS collected coincident with routine newborn screening if bleeding continued. Results: 92.5% of eligible mothers agreed to participate. 510 DBS were obtained of which 502 were successfully analysed. 216 (43%) samples contained PEth at a concentration of ≥8 ng/mL and 148 (29.5%) at ≥20 ng/mL. The sensitivity of PEth ≥8 ng/mL and ≥20 ng/mL in identifying women who self-reported modest alcohol use after 36 weeks' gestation was 50% and 36.4%, respectively. Conclusion: PEth measured from DBS obtained on day 5 of life does not reliably identify modest PAE after 36 weeks' gestation from maternal self-report
Determining the pattern and prevalence of alcohol consumption in pregnancy by measuring biomarkers in meconium
Get PDFObjective: To investigate the feasibility of determining the pattern and prevalence of alcohol consumption in pregnancy by measuring ethanol biomarkers in meconium.
Design: Population-based observational study.
Setting: Inner-city maternity unit in Scotland, UK.
Population: Random sample of singleton infants delivered after 36 completed weeks’ gestation.
Methods: Fatty acid ethyl esters (FAEEs) and ethyl glucuronide (EtG) in meconium were measured by liquid chromatography-mass spectroscopy. Samples were frozen at −20°C before analysis. Results were compared anonymously with demographic data including maternal age, parity, smoking, ethnicity and postcode and with infant gestation, birth weight and head circumference. Written informed consent was obtained from all subjects.
Results: 235 samples of meconium were analysed (70% of eligible babies). Only four (1%) of mothers declined to participate. FAAEs were detected in all, including four samples below the limit of quantification (10 ng/g). 98 (42%) samples had FAEE concentrations >600 ng/g. EtG was detectable in 93 (40%) samples; in 35 (15%) EtG concentration was >30 ng/g. No mother reported heavy alcohol consumption in pregnancy. FAAE concentration correlated with EtG (Pearson’s coefficient; p<0.001). There was no association between either biomarker and maternal age, parity, smoking, ethnicity or postcode, or infant gestation, birth weight or head circumference.
Conclusion: Measurement of ethanol biomarkers in meconium is a feasible tool for determining the pattern and prevalence of alcohol consumption in pregnancy. Data suggest that at least 15% of pregnant women in the west of Scotland are consuming significant quantities of alcohol during latter pregnancy
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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