Alcohol use trends in Dallas County during the COVID-19 pandemic.

Alcohol (ethanol) is the most widely detected drug in forensic toxicology casework and an increase in consumption of alcohol was reported during the COVID-19 pandemic. The increase in consumption could be attributed to rising stress levels and social isolation. To determine whether the pandemic had an impact on ethanol positivity and concentrations in cases analyzed by the Dallas County Southwestern Institute of Forensic Sciences, blood ethanol results were evaluated from January 1, 2019, through December 31, 2021. This time frame captured ethanol prevalence and concentrations before, during, and immediately following the pandemic for comparison. The average ethanol concentration in postmortem casework over the three years for each quarter ranged from 0.116 g/100 mL to 0.142 g/100 mL while the average concentration in driving while intoxicated (DWI) was higher, ranging from 0.173 g/100 mL to 0.188 g/100 mL. The ethanol positivity rate for postmortem casework remained relatively the same at approximately 20% during the time frame, while there was a decrease in ethanol positivity rate for DWI casework during the pandemic in April - June (Q2) 2020. However, the positivity rate returned to pre-pandemic levels by the end of 2020. Despite the self-reported surveys of increased alcohol consumption during the pandemic, a corresponding increase in average ethanol concentrations was not observed in Dallas County and the surrounding area.

Classical stimulants in Dallas County: A retrospective review of toxicological, seized drug, and demographical data from 2017 to 2022.

Cocaine and methamphetamine remain highly abused drugs in the United States due to their euphoric effects. This study examines classical stimulant casework, defined as cases positive for methamphetamine and/or cocaine, received by the Toxicology Laboratory and the Drug Analysis Laboratory at the Dallas County Southwestern Institute of Forensic Sciences from local law enforcement agencies and/or the Office of the Medical Examiner (OME) between January 1, 2017, and December 31, 2022. Methamphetamine positivity increased from 10.4% to 20.3% in the Toxicology Laboratory over the 6 years, whereas cocaine positivity remained relatively stable at approximately 17%. Similarly, in the Drug Analysis Laboratory, the methamphetamine positivity rate changed from 24.8% to 33.2%, whereas cocaine identification remained stable at approximately 20%. Blood concentrations of methamphetamine in OME cases ranged from 10.1-42,740.0 ng/mL while they were lower in DWI casework ranging from 10.2-2385.0 ng/mL. The blood concentration trends of cocaine were similar to methamphetamine, with OME casework ranging higher (10.0-24,501.0 ng/mL) than DWI casework (10.2-371.6 ng/mL). Polydrug use was evident for both methamphetamine and cocaine in postmortem cases, and the top three most frequently co-occurring drug/drug class were opioids/opiates, cannabinoids, and ethanol. The results from this study aid in the understanding of historical usage trends of cocaine and methamphetamine in Dallas County and how those trends have changed over time as newer stimulant drugs have emerged.

Heroin and fentanyl in Dallas County: A 5-year retrospective review of toxicological, seized drug, and demographical data.

The opioid epidemic resulted in an increase in identifications of fentanyl, fentanyl analogs, and heroin, among other opioids, in the toxicology and seized drug analysis fields over the past several years. The Dallas County Southwestern Institute of Forensic Sciences, comprised of the Toxicology Laboratory and Drug Analysis Laboratory, observed a rise in fentanyl-positive analyses in both laboratories. Fentanyl positivity increased from 1.1% to 3.4% in the Toxicology Laboratory over the five years of this study, whereas 6-monoacetylmorphine (6-MAM) positivity remained relatively stable at approximately 2%. Similarly, in the Drug Analysis Laboratory, the fentanyl positivity rate changed from 0.03% to 0.60%, whereas heroin identification remained stable at approximately 8-9%. Based on data obtained from toxicology submissions, a typical fentanyl or heroin user was a white male in their late 30s. The average concentration of fentanyl in postmortem cases, antemortem cases, and 6-MAM in postmortem specimens was 9.7 ng/ml, 5.5 ng/ml, and 68.4 ng/ml, respectively. Poly-drug use was evident, with benzodiazepines being the most commonly co-administered drug with fentanyl (49.4%). Multiple drugs were identified via analysis of clandestine tablets submitted to the Drug Analysis Laboratory, including fentanyl and/or heroin in combination with compounds such as cocaine, etizolam, and acetaminophen. The most frequently identified clandestine tablet was "M367," typically manufactured to contain acetaminophen and hydrocodone, but was found to contain fentanyl or heroin. The results from this study aid in the understanding of the current opioid trends in Dallas County and provides an opportunity for comparison to other populations and geographical regions.

Phencyclidine in Drivers and Decedents in Dallas County: A Five-Year Retrospective Review of Toxicological and Demographical Data.

Presented are phencyclidine (PCP)-positive cases received by the Toxicology Laboratory at the Southwestern Institute of Forensic Sciences from local law enforcement agencies and the Office of the Medical Examiner (OME) between 1 January 2015 and 31 December 2020. Of the 43,940 requests for testing received during that time, 898 (2.04%) were positive for PCP. These cases were evaluated for PCP concentration, additional/concurrently reported drug concentrations and demographics. For ME cases, the cause and manner of death were also evaluated. Although the number of requests received by the Toxicology Laboratory increased each year, the percentage positive for PCP remained consistent. Subjects ranged from 18 to 71 years old (median 48 years) and were predominantly black (94.19%) and male (78.49%). PCP concentrations for all case types ranged from 0.02 to 2.33 mg/L (median 0.05 mg/L); driving while intoxicated (DWI) cases ranged from 0.02 to 0.14 mg/L (median 0.04 mg/L) and ME cases ranged from 0.02 to 2.33 mg/L (median 0.13 mg/L). In addition to PCP, one or more drug(s) or metabolite(s) was identified concurrently in 69.49% of cases. Cannabinoids were the most frequently detected (39.8%), followed by cocaine and its metabolites (22.0%) and ethanol (18.5%). Results were similar when comparing the additional drugs reported in ME and DWI cases. PCP concentrations in ME samples were generally higher, especially for stimulant drugs. Of the 264 ME cases positive for PCP, the manner of death was determined to be an accident for the majority of cases (62.54%), and the most common cause of death was drug toxicity (35.61%). The results from this study facilitate comparison of laboratory- or region-specific data sets, help determine whether laboratory scopes meet testing needs, contribute to reference ranges and provide the foundation for well-informed policy decisions.

Evaluation of Amphiphilic Star/Linear-Dendritic Polymer Reverse Micelles for Transdermal Drug Delivery: Directing Carrier Properties by Tailoring Core versus Peripheral Branching.

The reverse micelle self-assembly of lipophile-functionalized poly(ethylene glycol) (PEG) dendrimer hybrids is probed for applications in carrier-mediated transdermal drug delivery. Under investigation are topologically diverse amphiphiles featuring controlled branching motifs at either the polymer core (one-, two-, and four-arm PEG) and the polar/nonpolar interface (peripheral dendritic generations 0-2). Thus, a systematic investigation of the effect of branching location (core vs peripheral) on carrier properties is described. Dye-encapsulation experiments verify these materials are capable of forming well-defined aggregates and solubilizing polar compounds. Further quantification of reverse micelle critical micelle concentration and dye loading capacity for the branched amphiphile library was obtained through spectroscopy characterization. Both core and peripheral branching are shown to significantly influence dynamic encapsulation behavior, with evidence of location-based contributions extending beyond multiplicity of branching alone. Finally, the in vitro transdermal diffusion of the reverse micelle carriers was investigated through Franz diffusion cell experiments using physiologically relevant juvenile porcine dermis. The permeation results, combined with previously reported aggregate size trends, show the complex relationship between polymer branching and transdermal transport, with the lowest core- and highest peripherally-branched amphiphilic analogs exhibiting optimal transdermal permeation characteristics for this set of branched carriers.

Synthesis and Self-Assembly of Amphiphilic Star/Linear-Dendritic Polymers: Effect of Core versus Peripheral Branching on Reverse Micelle Aggregation.

A series of branched polymers, consisting of a poly(ethylene glycol) (PEG) core and lipophilic peripheral dendrons, were synthesized and their self-assembly into reverse micelles studied toward the ultimate goal of carrier-mediated transdermal drug delivery. More specifically, this investigation systematically explores the structure-property contributions arising from location and extent of branching by varying the number of branch points at the core and the generation of dendrons at the polar/nonpolar interface. For branching at the core, PEGs were selected with one, two or four arms, with one terminal functionality per arm. For peripheral branching, end groups were modified with polyester dendrons (of dendritic generations 0, 1, and 2) for each of the three cores. Finally, lauric acid (LA) was used to esterify the periphery, yielding a library of branched, amphiphilic polymers. Characterization of these materials via MALDI-TOF MS, GPC and NMR confirmed their exceptionally well-defined structure. Furthermore, atomic force microscopy (AFM) and dynamic light scattering (DLS) confirmed these polymers' abilities to make discrete aggregates. As expected, increased multiplicity of branching resulted in more compact aggregates; however, the location of branching (core vs periphery) did not seem as important in defining aggregate size as the extent of branching. Finally, computational modeling of the branched amphiphile series was explored to elucidate the macromolecular interactions governing self-assembly in these systems.

Letter: The potential of amine-containing dendrimer mass standards for internal calibration of peptides.

In order to ensure accurate mass determinations, MALDI-TOF mass spectrometers must be calibrated regularly. While peptides and proteins represent the most widely used calibration standards due to their monodispersity, known masses and availability, their limited shelf-life complicates their use. Recently, polyester dendrimer calibrants have been introduced as an alternative because, in addition to monodispersity and relative molecular masses as high as 30,000, they exhibit vastly improved stability and broad compatibility with both matrices and solvents. However, the use of these initially reported polyester dendrimers as internal calibrants for the analysis of peptides or proteins presents a unique problem because these dendrimers typically require ionization with metal cations, while amino acid-based compounds preferentially ionize via protonation of an amine. To address this complication, dendrimers bearing a single amine were prepared which demonstrate the ability to easily ionize via protonation with either acidic matrices or dilute solutions of trifluoroacetic acid. This class of amine-containing dendrimers shows promise as a calibrant system specifically designed for the internal calibration of peptides.