Publications by authors named "Gwendolyn McMillin"

Background: About 95% of consumed ethanol is metabolized by oxidative pathways. Less than 1% is metabolized via nonoxidative pathways: glucuronidation, sulfation, and the formation of fatty acid esters of ethanol. In neonates, the glucuronidation pathway has been reported to be underdeveloped but matures with age.

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Article Synopsis
  • Substance use during pregnancy is prevalent, and while biological testing is done to detect these exposures, there is currently no standardized approach regarding when or how testing should occur.
  • This review highlights various specimen types (like urine, meconium, and umbilical cord tissue) and analytical methods (such as immunoassay and mass spectrometry) to help guide testing related to maternal and newborn substance exposure.
  • There are specific strengths and limitations in detection methods, and better standardization is needed to improve how substance exposure is evaluated, keeping in mind the possibility of false results.
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Importance: Cannabis use is increasing among reproductive-age individuals and the risks associated with cannabis exposure during pregnancy remain uncertain.

Objective: To evaluate the association between maternal cannabis use and adverse pregnancy outcomes known to be related to placental function.

Design, Setting, And Participants: Ancillary analysis of nulliparous individuals treated at 8 US medical centers with stored urine samples and abstracted pregnancy outcome data available.

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Article Synopsis
  • Urine drug screening is essential for monitoring the compliance of patients with pain management and substance use disorders, helping to ensure they are using prescribed medications and avoiding non-prescribed substances.
  • The LC-MS/MS method described allows for the analysis of 41 commonly prescribed drugs and their metabolites from a single urine sample, despite challenges like sample variability and differing drug chemistries.
  • The method includes an enzymatic hydrolysis step with cation exchange solid phase extraction, and uses resorufin-glucuronide as a control to minimize false negatives, utilizing an Agilent 6470 mass spectrometer for detection.
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Δ8-Tetrahydrocannabinol (Δ8-THC) and cannabidiol (CBD) are increasingly popular cannabinoids. Measuring metabolites in urine is an important tool for detecting use and/or exposure as well as for monitoring elimination of these two drugs. Distinguishing between the metabolite 11-nor-9-carboxy-Δ8-tetrahydrocannabinol (Δ8-THC-COOH) and the analogous metabolite of the more common and naturally abundant Δ9-THC: 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (Δ9-THC-COOH) is analytically challenging due to structural similarities between the two compounds.

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Article Synopsis
  • * The study tested labetalol in various concentrations across different specimen types (urine, plasma, meconium, and umbilical cord tissue) using validated drug tests, including immunoassay and LC-MS/MS.
  • * Results revealed that while labetalol can generate false positives in immunoassays, no false positives occurred with the more accurate LC-MS/MS tests, indicating the importance of using specific testing methods.
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Background: Many low-complexity urine drug screen (UDS) devices are approved by the Food and Drug Administration as waived under Clinical Laboratory Improvement Amendments (CLIA) criteria. Labeling instructs patients to urinate directly into the device and also states that positive results should be confirmed. However, the device itself may pose a risk of drug adsorption and/or specimen contamination that could affect results in confirmatory assays if specimens are reused.

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Context.—: Consequences related to nicotine (NIC) use remain a major health concern, leading to demand for testing to detect NIC, metabolites such as cotinine (COT), and related tobacco alkaloids, including anabasine (ANAB). NIC-related testing is not standardized among laboratories, nor are there clinical or regulatory guidelines to inform decisions such as appropriate screening cutoffs or limits of quantitation.

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Kratom is an herbal drug that is legal in the USA. While it is marketed as a safer alternative to opioids, it can cause opioid-like withdrawal symptoms when discontinued after regular use. Several case studies have shown that kratom exposure in utero can lead to symptoms in newborns consistent with neonatal abstinence syndrome.

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Our objective was to evaluate whether cannabis use was associated with nausea and vomiting in early pregnancy. Participants from nuMoM2b (Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be) enrolled from October 2010 through September 2013 with a PUQE (Pregnancy-Unique Quantification of Emesis) questionnaire and an available stored urine sample from the first study visit (median gestational age 12 weeks) were included. Cannabis exposure was ascertained by urine immunoassay for 11-nor-9-carboxy-delta-9-tetrahydrocannabinol (THC-COOH); positive results were confirmed with liquid chromatography tandem mass spectrometry.

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Objective: Our primary objective was to estimate statewide prenatal substance exposure based on umbilical cord sampling. Our secondary objectives were to compare prevalence of prenatal substance exposure across urban, rural, and frontier regions, and to compare contemporary findings to those previously reported.

Methods: We performed a cross-sectional prevalence study of prenatal substance exposure, as determined by umbilical cord positivity for 49 drugs and drug metabolites, through the use of qualitative liquid chromatography-tandem mass spectrometry.

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Maternal drug use during pregnancy is a significant concern. Drug-exposed newborns are often born premature and may suffer from birth defects, neonatal abstinence syndrome and cognitive and developmental delays. Because of this, testing of neonatal specimens is carried out to assess fetal drug exposure during pregnancy.

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Monitoring concentrations of thiopurine metabolites is used clinically to prevent adverse effects in patients on thiopurine drug therapy. We developed a LC-MS/MS method for the quantification of 6-thioguanine (6-TG) and 6-methylmercaptopurine (6-MMP) in red blood cells (RBCs). This method utilizes an automated cell washer for RBC separation from whole blood samples and washing of the separated RBCs.

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Pharmacogenomic testing interrogates germline sequence variants implicated in interindividual drug response variability to infer a drug response phenotype and to guide medication management for certain drugs. Specifically, discrete aspects of pharmacokinetics, such as drug metabolism, and pharmacodynamics, as well as drug sensitivity, can be predicted by genes that code for proteins involved in these pathways. Pharmacogenomics is unique and differs from inherited disease genetics because the drug response phenotype can be drug-dependent and is often unrecognized until an unexpected drug reaction occurs or a patient fails to respond to a medication.

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Objectives: Nicotine (NIC) use during pregnancy can influence markers used in biochemical maternal serum screening. This study was designed to determine prevalence of disclosed tobacco smokers in our patient population and to compare disclosed tobacco smoking status with the presence of serum nicotine and a common tetrahydrocannabinol (THC) metabolite.

Methods: A deidentified dataset of disclosed smoking status for quadruple (Quad) screens was obtained.

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Background: Hydrocodone is the most prescribed opioid in the US. The objective was to evaluate associations between genetic, intrinsic, and extrinsic patient factors, plasma hydrocodone and metabolites, common side effects, and pain scores in a cohort of orthopedic surgery patients.

Methods: Data for each patient was collected by review of the electronic hospital record (EHR), and patient interview.

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The objective of this study was to review the results of umbilical cord drug screening in twins and triplets (multiples) to compare the detected drug(s) and/or drug metabolite(s). Results that did not agree between multiples were considered mismatched and investigated. A retrospective analysis was conducted using de-identified data from a national reference laboratory, and results were compared with data from an academic medical center, where detailed medical chart review was performed.

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Background And Aims: To estimate during pregnancy correlations between frequency of self-reported use of marijuana and quantified marijuana metabolite in biospecimens including urine, sera and umbilical cord homogenate.

Design: Prospective cohort.

Setting: Two urban hospitals in Colorado with legal recreational and medicinal marijuana.

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Patients with breast cancer often receive many drugs to manage the cancer, side effects associated with cancer treatment, and co-morbidities (i.e., polypharmacy).

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Introduction: The prevalence of 2R/2R TYMS genotype is variable but estimated to be around 20-30% in Caucasians. The clinical relevance of TYMS 2R/2R genotype in predicting severe fluoropyrimidine-related adverse events (FrAE) is controversial. Here, we explored the prevalence and clinical relevance of 2R/2R TYMS genotype.

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Background: This review provides a description of how the opioid epidemic has impacted drug testing.

Methods: Four major service areas of drug testing were considered, including emergency response, routine clinical care, routine forensics, and death investigations.

Results: Several factors that the opioid epidemic has impacted in drug testing are discussed, including specimens, breadth of compounds recommended for testing, time to result required for specific applications, analytical approaches, interpretive support requirements, and examples of published practice guidelines.

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