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Biomedical subjects

B A Goldberger

Publications and source records attributed to B A Goldberger.

At least 19 recordsLinked to original sources

Rapid detection of benzoylecgonine in vitreous humor by enzyme immunoassay.

The usual specimens submitted by a medical examiner for toxicological analysis include blood, urine, bile, vitreous humor, stomach contents, and solid-organ tissue. The detection of drugs in these specimens typically involves a combination of techniques including colorimetry, immunoassay, and gas chromatography. Although many laboratories rely principally on urine for the detection of drugs of abuse by immunoassay, these assays may be applied to other specimen types. An evaluation of Microgenics Corporation's cloned enzyme donor immunoassay (CEDIA) was conducted in order to evaluate its use in the detection of cocaine/cocaine metabolites in vitreous humor specimens. During a 14-month period, 392 vitreous humor specimens were analyzed by the CEDIA DAU Cocaine assay. Instrument parameters were set according to published manufacturer's guidelines. All presumptive positive immunoassay results prompted confirmatory testing and quantitation by gas chromatography-mass spectrometry (GC-MS) of other specimens including blood. Vitreous humor specimens were not tested by GC-MS. Using a approximately 100-ng/mL cutoff, the CEDIA assay produced 23 presumptive positive results, 22 of which were confirmed by GC-MS. The only specimen which could not be confirmed, elicited an immunoassay screen value near the cutoff limit. Routine analysis of blood, urine, bile, and/or bladder wash specimens by gas chromatography-nitrogen phosphorus detection revealed the presence of cocaine/cocaine metabolites in only 7 (31.8%) of the 22 confirmed cases. The concentration ranges of cocaine and benzoylecgonine in the blood specimens were none detected to 337 ng/mL and 17 to 8598 ng/mL, respectively. Cocaethylene was not detected in these cases. Analysis of vitreous humor specimens by CEDIA improved the detection rate of cocaine/cocaine metabolites by 0.7% in the cases submitted to our laboratory during the 14-month period.

Autopsy↗

Detection of cocaine and its metabolites in breast milk.

A method was developed for measuring cocaine and its metabolites, benzoylecgonine, ecgonine methyl ester, norcocaine, ecgonine ethyl ester, cocaethylene, and m-hydroxybenzoylecgonine, in breast milk by gas chromatography/mass spectrometry. Limits of detection for this method ranged from 2.5 to 10 ng/mL, and limits of quantitation ranged from 5 to 50 ng/mL. For each of the compounds measured by this method, linear response was demonstrated to 750 ng/mL. Breast milk was collected from 11 mothers who admitted to drug use during pregnancy and ten drug-free volunteers serving as control subjects. Cocaine was detected in six of the specimens obtained from drug-exposed subjects, and in none of the drug-free control subjects. In breast milk specimens where cocaine and one or more of its metabolites were detected, the concentration of parent compound was greater than any of the metabolites. The highest cocaine concentration found was over 12 microg/mL. Breast-fed infants of cocaine abusing mothers may be exposed to significant amounts of drug orally.

Adult↗

The disposition of cocaine and opiate analytes in hair and fingernails of humans following cocaine and codeine administration.

This study investigated the disposition patterns of cocaine and opiates into hair and fingernail specimens collected from 8 volunteers enrolled in a 10-week inpatient clinical study. All subjects were African-American males with a confirmed drug use history. Scalp hair and fingernail scrapings were collected weekly throughout the course of the study. Head hair was collected from the posterior vertex region, and fingernail scrapings were collected along the entire ventral surface of the nail plate. The specimens were introduced to successive decontamination washes including an isopropanol wash and three phosphate buffer washes. All decontamination washes were collected and analyzed. All specimens were enzymatically digested prior to being subjected to solid-phase extraction and derivatization. Analyses were performed using electron impact gas chromatography-mass spectrometry. Analytes investigated included eight cocaine analytes and five codeine analytes. The limit of quantitation for all analytes ranged from 0.1 to 0.5 ng/mg for both matrices. Cocaine was present at the highest concentrations of any analyte in both hair and nail. Benzoylecgonine and ecgonine methyl ester were the primary metabolites in both matrices and were typically less than 15% of cocaine concentrations. Codeine was the only opiate analyte identified in either hair or nail. Observed drug disposition profiles were different for hair and nails. A significant dose-response relationship was observed for hair specimens. The mean peak concentrations in hair after low dosing were half the concentration observed after high-dose administration. Generally, no clear relationship was evident between nail drug concentrations and dose. Decontamination washes removed less than 20% of the total drug present in hair, but removed most of the drug concentrations (60-100%) in nail. This investigation demonstrated that higher concentrations of drug were found in the subjects' hair than in their fingernails and that cocaine was found in both matrices at a greater concentration than codeine. Although both hair and nail have similar physical and chemical properties and may share common mechanisms of drug incorporation, this clinical study suggests that there are distinct differences in their disposition profiles.

Area Under Curve↗

Modification of screening immunoassays to detect sub-threshold concentrations of cocaine, cannabinoids, and opiates in urine: use for detecting maternal and neonatal drug exposures.

Testing for drugs of abuse in urine is commonplace in emergency departments and neonatal units. However, the clinical sensitivity of immunochemical screening methods is limited by the threshold concentrations used to distinguish between positive and negative specimens. Immunochemical screening methods for cocaine metabolite (benzoylecgonine), cannabinoids, and opiates in urine were recalibrated to detect drugs at lower threshold concentrations. The precision and linearity of the signals at the modified thresholds were verified by diluting drug-positive urine specimens to concentrations below the conventional cutoff concentration and measuring the rate signals in triplicate. To assess the clinical performance of the modified methods, specimens that tested negative using the unmodified assays were re-screened at the lower threshold, and specimens that re-screened positive were submitted for gas chromatographic/mass spectrometric (GC/MS) confirmation. Reproducibility of sub-threshold measurements was comparable to the unmodified assays, and rate separations between successive dilutions were sufficient to give semi-quantitative results. Using the lower thresholds, drugs were detected in 4-5% of the subjects that had screened negative at the conventional threshold concentration. GC/MS analysis confirmed the presence of cannabinoids and cocaine metabolite in 74% and 84%, respectively, of urine specimens that re-screened positive. Morphine, codeine, hydromorphone, or hydrocodone was detected by GC/MS analysis in 31% of opiate-positive re-screens.

Adult↗

Analysis of gamma-hydroxybutyrate (GHB) in urine by gas chromatography-mass spectrometry.

A simple method for the direct analysis of gamma-hydroxybutyrate (GHB) from human urine is described. The method uses solid-phase extraction, liquid-liquid extraction, and silyl-derivatization, then gas chromatographic-mass spectrometric analysis using GHB-d6 as the internal standard. The method was linear from 5 to 500 mg/L, and coefficients of variation were less than 10%. Twenty-six urine specimens previously analyzed by an existing method were analyzed and yielded GHB concentrations ranging from 0 to 6100 mg/L; the results correlated between the two methods. Compared with existing methods, the method described here is superior because it is specific to GHB and can discriminate between GHB and gamma-butyrolactone.

4-Butyrolactone↗

Monitoring cocaine use in substance-abuse-treatment patients by sweat and urine testing.

Sweat and urine specimens were collected from 44 methadone-maintenance patients to evaluate the use of sweat testing to monitor cocaine use. Paired sweat patches that were applied and removed weekly (on Tuesdays) were compared with 3-5 consecutive urine specimens collected Mondays, Wednesdays, and Fridays. All patches (N = 930) were extracted in 2.5 mL of solvent and analyzed by ELISA immunoassay (cutoff concentration 10 ng/mL); a subset of patches (N = 591) was also analyzed by gas chromatography-mass spectrometry (GC-MS) for cocaine, benzoylecgonine (BZE), and ecgonine methyl ester (EME) (cutoff concentration 5 ng/mL). Urine specimens were subjected to qualitative analysis by EMIT (cutoff 300 ng/mL) and subsets were analyzed by TDx (semiquantitative, LOD 30 ng/mL) and by GC-MS for cocaine (LOD 5 ng/mL). Results were evaluated to (1) determine the relative amounts of cocaine and its metabolites in sweat; (2) assess replicability in duplicate patches; (3) compare ELISA and GC-MS results for cocaine in sweat; and (4) compare the detection of cocaine use by sweat and urine testing. Cocaine was detected by GC-MS in 99% of ELISA-positive sweat patches; median concentrations of cocaine, BZE, and EME were 378, 78.7, and 74 ng/mL, respectively. Agreement in duplicate patches was approximately 90% by ELISA analysis. The sensitivity, specificity, and efficiency of sweat ELISA cocaine results as compared with sweat GC-MS results were 93.6%, 91.3%, and 93.2%, respectively. The sensitivity, specificity, and efficiency between ELISA sweat patch and EMIT urine results were 97.6%, 60.5%, and 77.7%, respectively. These results support the use of sweat patches for monitoring cocaine use, though further evaluation is needed.

Adolescent↗

Detection of methadone, methadone metabolites, and other illicit drugs of abuse in hair of methadone-treatment subjects.

The disposition of methadone, its metabolites, and other illicit drugs of abuse was investigated in head hair samples collected from heroin users (N = 20) enrolled in an outpatient detoxification study. Hair samples were assayed for methadone, methadone primary metabolite (2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine, EDDP), methadone secondary metabolite (2-ethyl-5-methyl-3,3-diphenylpyrroline, EMDP), cocaine, phencyclidine, heroin, and 6-acetylmorphine. Hair samples were cut, washed, and incubated in methanol. The methanolic hair wash and incubation fractions were purified with solid-phase extraction and assayed by gas chromatography-mass spectrometry. Methadone, methadone metabolites, cocaine, and phencyclidine were assayed quantitatively, and other drugs were measured qualitatively. The number of positive results and the corresponding concentration ranges were as follows: methadone, 0-15.0 ng/mg (N = 18); EDDP, trace (N = 13); EMDP, trace (N = 1); cocaine, 0->40 ng/mg (N = 14); phencyclidine, 0-1.5 ng/mg (N = 2); heroin, positive (N = 3); and 6-acetylmorphine, positive (N = 4). These data suggest that testing hair for methadone, methadone metabolites, and other illicit drugs of abuse may be useful to drug-treatment specialists as a means of verifying drug-use history, monitoring compliance, and providing a broad measure of drug exposure.

Gas Chromatography-Mass Spectrometry↗

Identification of cocaine analytes in fingernail and toenail specimens.

Fingernail and toenail specimens were obtained from 18 suspected cocaine users. The nails were cut, heated under methanolic reflux, and the methanolic extracts were purified by solid-phase extraction. Gas chromatography/mass spectrometry was utilized for the qualitative and quantitative analysis of nine cocaine analytes. Comparison of conventional postmortem analysis of blood and urine with nail analysis revealed a marked increase in the detection of cocaine use by nail analysis. Cocaine analytes were present in 14 (82.3%) subjects utilizing nail analysis. Out of those 14 subjects, only 5 (27.7%) were positive by conventional postmortem drug analysis. Cocaine and benzoylecgonine were the predominant analytes in all positive nail specimens. Anhydroecgonine methyl ester, ecgonine methyl ester, ecgonine ethyl ester, cocaethylene, norcocaine, and norbenzoylecgonine were detected in a limited number of specimens. The ratio of cocaine to benzoylecgonine ranged from 2-10:1. These findings suggest that nails may be a useful alternative matrix for the detection of cocaine exposure.

Adolescent↗

Recreational drugs. Current trends in the 90s.

Recreational drug use continues to be prevalent in many social settings. These drugs are alleged to enhance sociability and liberate inhibitions, allowing the user to experience feelings of euphoria. This article reviews recreational drugs that have gained notoriety in the 1990s including gamma-hydroxybutyrate (GHB), flunitrazepam, and amphetamine analogues such as 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA), and 3,4-methylenedioxyethylamphetamine (MDEA). Topics discussed include history, drug use and misuse, clinical presentation and treatment, and laboratory analysis.

Amphetamine-Related Disorders↗

Rapid liquid-liquid extraction of cocaine from urine for gas chromatographic-mass spectrometric analysis.

A novel, simple and economic liquid-liquid extraction method for isolating cocaine from urine was developed utilizing gas chromatography-mass spectrometry (GC-MS) for analysis and quantification. The use of a single nonpolar organic solvent allowed only nonpolar analytes to be extracted from the biological fluid, and consequently, no derivatization step was necessary before GC-MS analysis. Large numbers of specimens (>60) can be extracted in approximately 3 h with this procedure. The method is highly precise (C.V. <7%), accurate (>98%), sensitive (limit of detection of 5 ng/ml) and has a mean recovery of 48.8%.

Alkanes↗

Identification of unique cocaine metabolites and smoking by-products in postmortem blood and urine specimens.

Toxicological investigation of suspected cocaine-related deaths routinely involves the identification of cocaine (COC) and its metabolites including benzoylecgonine (BE) and ecgonine methyl ester (EME) in postmortem specimens. We utilized solid-phase extraction followed by gas chromatography/mass spectrometry for the qualitative and quantitative analysis of cocaine and eight cocaine-related analytes. These analytes included anhydroecgonine methyl ester (AEME), a unique product formed during cocaine smoking, and cocaethylene (CE), formed by transesterification of cocaine in the presence of ethanol. Thirteen pairs of postmortem heart blood and urine specimens were analyzed from cases of death due to acute cocaine intoxication, multiple drug intoxication, or other non-drug related causes. COC, EME, and BE were detected in all specimens. The range of concentrations in blood were: COC, 23-2088 ng/mL; BE, 215-9195 ng/mL; and EME, 220-7275 ng/ mL. AEME was identified in 2 blood and 10 urine specimens, and CE was identified in 1 blood specimen and 4 urine specimens. The identification of AEME in the specimens indicated that "crack" cocaine had been smoked, and the presence of CE indicated co-administration of cocaine and ethanol. The presence of these unique cocaine analysis in postmortem specimens provides valuable information regarding the cause and manner of death.

Cocaine↗

Confirmatory tests for drugs in the workplace by gas chromatography-mass spectrometry.

The Mandatory Guidelines for Federal Workplace Drug Testing Programs require the use of gas chromatography-mass spectrometry (GC-MS) for the confirmation of presumptive positive urine specimens. This review focuses upon GC-MS methods developed specifically for forensic confirmation of amphetamine, methamphetamine, 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid (THC-acid), benzoylecgonine, morphine, codeine and phencyclidine in urine for purposes of workplace drug testing. In addition, current laboratory issues pertaining to each drug class are reviewed. Generally, drug assays utilized either liquid-liquid or solid-phase extraction methods, derivatization if necessary, and GC-MS detection operating in the selected ion monitoring mode or by full scan acquisition.

Amphetamines↗