318 research outputs found
Recruiters' perspectives and experiences of trial recruitment processes:a qualitative evidence synthesis protocol
Get PDFUrinary nandrolone metabolite detection after ingestion of a nandrolone precursor
Get PDFIntroduction: Quantities of various anabolic/ androgenic steroids have been found in dietary
supplements without their presence being disclosed on the label. The aim of this study was to
quantify the excretion patterns of the diagnostic metabolites, 19-norandrosterone (19-NA) and
19-noretiocholanolone (19-NE), after ingestion of small doses of 19-nor-4-androstene-3,17-
dione (19-norandrostenedione). Methods: Eleven males and nine females entered the
laboratory in the morning following an overnight fast. An initial urine sample was collected
and volunteers then ingested 500 mL of water containing 5 g of creatine monohydrate and
either 1.0 μg, 2.5 μg or 5.0 μg of 19-norandrostendione. The volume of each urine void was
measured and an aliquot taken. Samples were analysed for the metabolites 19-NA and 19-NE
by GCMS. Results Baseline urinary 19-NA concentrations were 0.19±0.14 ng/mL. Ingestion
of the supplement resulted in peak mean urinary 19-NA concentrations of 0.68±0.36 ng/mL,
1.56±0.86 ng/mL, and 3.89±3.11 ng/mL in the 1.0μg, 2.5μg or 5.0μg trials respectively.
Under current WADA regulations, ingestion of the 1.0 μg dose produced 0 positive doping
tests, 5 subjects (20%) tested positive in the 2.5 μg trial and 15 subjects (75%) had urinary 19-
NA concentrations exceeding 2 ng/mL after ingesting creatine containing 5.0 μg of the
steroid. The recovery of the ingested dose was highly variable between individuals, with
values ranging from 11 - 84 % (mean±SD = 47 ± 18%). Conclusions: Ingestion of trace
amounts of 19-norandrostendione can result in transient elevations of urinary 19-NA and 19-
NE concentrations. The addition of as little as 2.5 μg of 19-norandrostendione to a
supplement (0.00005% contamination) appears sufficient to result in a doping violation in
some individuals
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Pubertal timing and breast density in young women: a prospective cohort study.
Get PDFBACKGROUND:Earlier age at onset of pubertal events and longer intervals between them (tempo) have been associated with increased breast cancer risk. It is unknown whether the timing and tempo of puberty are associated with adult breast density, which could mediate the increased risk. METHODS:From 1988 to 1997, girls participating in the Dietary Intervention Study in Children (DISC) were clinically assessed annually between ages 8 and 17 years for Tanner stages of breast development (thelarche) and pubic hair (pubarche), and onset of menses (menarche) was self-reported. In 2006-2008, 182 participants then aged 25-29 years had their percent dense breast volume (%DBV) measured by magnetic resonance imaging. Multivariable, linear mixed-effects regression models adjusted for reproductive factors, demographics, and body size were used to evaluate associations of age and tempo of puberty events with %DBV. RESULTS:The mean (standard deviation) and range of %DBV were 27.6 (20.5) and 0.2-86.1. Age at thelarche was negatively associated with %DBV (p trend = 0.04), while pubertal tempo between thelarche and menarche was positively associated with %DBV (p trend = 0.007). %DBV was 40% higher in women whose thelarche-to-menarche tempo was 2.9 years or longer (geometric mean (95%CI) = 21.8% (18.2-26.2%)) compared to women whose thelarche-to-menarche tempo was less than 1.6 years (geometric mean (95%CI) = 15.6% (13.9-17.5%)). CONCLUSIONS:Our results suggest that a slower pubertal tempo, i.e., greater number of months between thelarche and menarche, is associated with higher percent breast density in young women. Future research should examine whether breast density mediates the association between slower tempo and increased breast cancer risk
The Principal Pauline Epistles:A Collation of Old Latin Witnesses
Get PDFThis collation presents the evidence for the earliest Latin versions of Romans, 1 and 2 Corinthians and Galatians, enabling scholars to examine the development of the biblical text at an important early stage in its history. Readership: Scholars of the New Testament text, the development of Christian theology, the history of the Latin language, translation studies. An important reference work for research institutes and academic libraries
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