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THCA in Head Hair: A Comparison with Fingernail
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Conflict of Interest Employees of USDTL Privately held company Commercial laboratory Sells hair testing services Internally funded No role in: Study design Data collection Analysis publication
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Marijuana usage trends THCA in hair and nail Validation w 10 fg/mg LOD Comparison hair and nail Conclusions OBJECTIVES
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Most common illicit drug 2010-17.4 M past month users 2009 factor 376k ED visits Trends of Marijuana Use
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Trends of Marijuana Use 23 States and DC Legalized Medical use Decriminalized Both
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Trends of Marijuana Use Daily use 12 th graders 6.5% from 5.1% in 2007 12 th graders negative perception of regular use 44.1%, lowest since 1979
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What Do We Look For? THCTHCA
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Detection Windows
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#1 ENVIRONMENTAL EXPOSURE SMOKE TRANSFERANCE CONTACT FUMES HOW DO DRUGS GET INTO THE HAIR?
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#2 SWEAT AND OIL THESE DRUG AND METABOLITE CONTAINING FLUIDS BATHE THE HAIR SHAFT
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HOW DO DRUGS GET INTO THE HAIR? #3 THE BLOOD
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Specimen Type: Why Fingernail?
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Anatomy of Fingernail NAIL MATRIX NAIL PLATE NAIL BED
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Fingernails Are Made of Keratin o Keratin: fibrous structural protein of hair, nails, horn, hoofs, wool, feathers, and of the epithelial cells in the outermost layers of the skin. The polypeptide chains of keratin are arranged in parallel sheets held together by hydrogen bonding. ~ Encyclopedia Britannica
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Fingernails Are Made of Keratin o These keratin sheets stack on top of each other, giving the nail thickness and length, making adulteration of the specimen difficult.
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Incorporation of Drug Biomarker: a measurable substance whose presence is indicative of ingestion or exposure to substances of abuse (SOA).
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NAIL MATRIX NAIL BED o Biomarkers can be found in nails as early as 1-2 weeks after substances of abuse are ingested. o The time period during which drug ingestion can be detected depends on the substance used, the amount used, and personal metabolism. Biomarker Absorption
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Single point Calibrator – 50 fg/mg LOQ – 20 fg/mg LOD – 10 fg/mg ULOL – 1000 fg/mg Controls 20, 62.5, and 400 fg/mg Robust – minimum 22 consecutive days THCA Validation Specs
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LOD 10 fg/mg LOQ 20 fg/mg ULOL 500 fg/mg Imprecision < 13.5% Bias < 13.8% Stable THCA Validation Results
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1000 fg = 1 pg 1000 pg = 1 ng What is a Femtogram
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THCA Low Control
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The Collection of Specimen NIAAA – 1 R44 AA016463-02 (Phase II) UW- Milwaukee- CABHR De-identified Remnants
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POSITIVITY RATE THCA HAIR/NAIL
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MEAN CONCENTRATIONS THCA HAIR/NAIL Paired Sample t-Test Difference 1449.2 +/- 745.3 t = 1.944, df = 59, P < 0.05
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60 Matched Pairs of Hair and Nail
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LIMITATIONS Accurate self-report Verified dose administration Demographics Prevalence not generalizable Personal hygiene Cosmetic treatment
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Published Results
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CONCLUSION Method is very sensitive & robust Nail is a suitable alternative [THCA] hair/nail strongly associated Slightly higher positivity rate in nail [THCA] up to 5x higher
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All Rights Reserved. Copyright © 2013 United States Drug Testing Laboratories, Inc. Thank You
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