Biomedical subjects

Jeri D Ropero-Miller

Publications and source records attributed to Jeri D Ropero-Miller.

6 recordsLinked to original sources

PubMed2006

External contamination of hair with cocaine: evaluation of external cocaine contamination and development of performance-testing materials.

The National Laboratory Certification Program undertook an evaluation of the dynamics of external contamination of hair with cocaine (COC) while developing performance testing materials for Federal Drug-Free Workplace Programs. This characterization was necessary to develop performance materials that could evaluate the efficacy of hair testing industry's decontamination procedures. Hair locks (blonde to dark brown/black) from five different individuals were contaminated with cocaine HCl. Hair locks were then treated with a synthetic sweat solution and hygienic treatments to model real-life conditions. Hair locks were shampooed daily (Monday through Friday) for 10 weeks, and samples of the hair locks were analyzed for COC, benzoylecgonine (BE), cocaethylene (CE), and norcocaine (NCOC). Three commercial analytical laboratories analyzed samples under three protocols: no decontamination procedure, individual laboratory decontamination, or decontamination by an extended buffer procedure at RTI International. Results indicated substantial and persistent association of all four compounds with all hair types. Hair that was not decontaminated had significantly greater quantities of COC and BE than did hair that was decontaminated. The only hair samples below detection limits for all four compounds were those decontaminated 1 h after contamination. Additionally, BE/COC ratios increased significantly over the 10-week study (regardless of decontamination treatment). From 21 days postcontamination until the end of the study, the mean BE/COC ratio for all hair types exceeded 0.05, the proposed Federal Mandatory Guidelines requirement. The largest variability in results was observed for samples decontaminated by participant laboratories. This suggests that current laboratory decontamination strategies will increase variability of performance testing sample results. None of the decontamination strategies used in the study were effective at removing all contamination, and some of the contaminated hair in this study would have been reported as positive for cocaine use based on the proposed Federal Mandatory Guidelines.

Cocaine↗

PubMed2006

Postmortem tissue distribution of atomoxetine following fatal and nonfatal doses--three case reports.

Atomoxetine (Strattera, Lilly) is a selective norepinephrine reuptake inhibitor (SNRI) prescribed for the treatment of attention-deficit/hyperactivity disorder (ADHD) in children, adolescents, and adults. It is the first nonstimulant drug-therapy option for ADHD. Three case reports are presented in which atomoxetine was detected in two individuals who died from causes unrelated to the drug and a third from the intentional ingestion of atomoxetine and other drugs. In addition, a brief description of the pharmacokinetics and side effects of atomoxetine are given. Postmortem fluid and tissue concentrations of atomoxetine were as follows: aortic blood, <0.1-8.3 mg/L; femoral blood, 0.33-5.4 mg/L; vitreous humor, 0.1-0.96 mg/L; bile, 1.0-33 g/L; urine, <0.1 mg/L; liver, <0.44-29 mg/kg; and gastric contents, 0.0097-16.8 mg total. Autopsy findings in the two cases in which death was not attributed to drug toxicity included arrhythmogenic right ventricular dysplasia and hypertrophic cardiomyopathy. The analytical method utilized was a modified basic drug, liquid-liquid procedure followed by gas chromatography/mass spectrometry and nitrogen phosphorous detection. Atomoxetine can be considered nontoxic at whole blood and liver concentrations below 1.3 mg/L and 5 mg/kg, respectively.

Adrenergic Uptake Inhibitors↗

PubMed2004

Metaxalone (Skelaxin)-related death.

The case history and toxicological findings of a fatal multi-drug overdose involving metaxalone (Skelaxin) are presented. Gas-liquid chromatography with flame-ionization detection and gas chromatography-mass spectrometry were used to determine the following drug concentrations (mg/L) in aortic blood: 19 mg/L metaxalone; 190 mg/L acetaminophen; 0.28 mg/L hydrocodone; and < 0.1 mg/L diazepam, nordiazepam, amitriptyline, and nortriptyline. The following concentrations of metaxalone were reported in alternate specimens: 17 mg/L in femoral blood; 44 mg/L in bile; 70 mg/kg in liver; 7 mg/L in urine; 202 mg/kg in gastric contents; and 14 mg/L in vitreous humor. These concentrations were determined using both direct extraction and the method of standard addition. The quantitative results obtained by both procedures were in good agreement. Because of the limited information published on metaxalone toxicity, the pathologist assigned the manner and cause of death as accidental acute hydrocodone intoxication. Four additional cases in which metaxalone was present were analyzed for comparison. Two cases were probable drug-related deaths and had metaxalone aorta blood concentrations of 18 and 11 mg/L. The other two cases had therapeutic metaxalone concentrations in the aortic blood of < 0.75 and 2.1 mg/L.

Adult↗

PubMed2002

Simultaneous quantitation of opioids in blood by GC-EI-MS analysis following deproteination, detautomerization of keto analytes, solid-phase extraction, and trimethylsilyl derivatization.

Seven opioid analytes including codeine, morphine, 6-acetylmorphine, hydrocodone, hydromorphone, oxycodone, and oxymorphone were detected in postmortem blood (n > 1000). Two milliliters of specimen was deproteinated with approximately 2.5 mL of methanol and derivatized with hydroxylamine before solid-phase extraction and derivatization with BSTFA + 1% TMCS. Extracts were assayed by gas chromatography-electron impact-mass spectrometry utilizing selected ion mode. One-microliter aliquots were injected onto an HP-1MS capillary column (30 m x 0.25-mm i.d., 0.25 microm) with a helium linear velocity of 62 cm/s. Temperature programming began at 160 degrees C (hold 0 min), then increased at rates of 35 degrees C/min to 195 degrees C, 5 degrees C/min to 240 degrees C, and 30 degrees C/min to 300 degrees C (hold 2 min) resulting in a total run time of 14-min. Quantitative determinations were based on the ratios of the analyte peak areas to the corresponding deuterated analogues. Calibration curves were linear for the following concentrations: 10-500 ng/mL (6-AM), 100-2000 ng/mL (oxycodone), and 50-1000 ng/mL (all other opioids). LOQs ranged from 5 ng/mL (6-AM) to 20 ng/mL (oxycodone). Between-run precision yielded CVs ranging from 2.79% to 5.34% (n = 12). These data suggest that methanolic deproteination and dual derivatization improve separation and simultaneous quantitation of seven opioid analytes in difficult matrices.

Forensic Medicine↗

PubMed2002

HbA1c as a postmortem tool to identify glycemic control.

Estimates suggest that more than 5A million U.S. citizens unknowingly have diabetes and are at increased risk of morbidity and mortality. We evaluated an immunoturbidimetric measurement of glycated hemoglobin (%HbA1c) as a postmortem tool to identify such individuals. Although postmortem samples undergo some degradation, the effects are not sufficient to invalidate the use of the test or method. Using two study populations whose medical history of diabetes was known, we found the mean %HbA1c of the non-diabetics (5.8+/-0.3) to be statistically different from that of the diabetics (12.4+/-2.8). For the population whose disease status was unknown, the %HbA1c ranged from 4.7 to 16.8. For six unknowns whose values exceeded 7.0%. the mean was 11.7%, which did not differ statistically from the diabetic mean (p = 0.6615). These studies suggest that postmortem blood samples can be used to characterize HbA1c values.

Adolescent↗

PubMedDate not supplied

Postmortem distribution of tramadol, amitriptyline, and their metabolites in a suicidal overdose.

A case report involving a 34-year-old white male who was found dead at home by his roommate is presented. At the time of his death, he was being treated with tramadol/acetaminophen, metaxalone, oxycodone, and amitriptyline. The decedent's mother stated that he had been taking increasing amounts of pain medication in order to sleep at night. There were no significant findings at autopsy; however, toxicology results supported a cause and manner of death resulting from suicidal mixed tramadol and amitriptyline toxicity. This case reports the tissue and fluid distribution of tramadol, amitriptyline, and their metabolites in an acutely fatal ingestion in an effort to document concentrations of these analytes in 12 matrices with respect to one another to assist toxicologists in difficult interpretations.

Adult↗