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Biomedical subjects

A Tracqui

Publications and source records attributed to A Tracqui.

At least 19 recordsLinked to original sources
PubMed1998

Confirmation of oleander poisoning by HPLC/MS.

A non-fatal case of Nerium oleander (common oleander) self-poisoning in a 45-year-old female is presented. Initial symptoms were nausea and vomiting, abdominal pain, phosphenes, cardiovascular shock and sinus brady-cardia. Blood and urine were assayed for oleandrin, the major cardiac glycoside of N. oleander, using a highly specific HPLC/MS procedure. The blood concentration of oleandrin at admission was 1.1 ng/ml. This is the first report of an oleander intoxication ascertained by the mass spectrometric identification of oleandrin in blood. HPLC/MS appears to be the method of choice for the forensic-toxicological investigation of poisonings by cardiac glycosides.

Cardenolides↗
PubMed1998

Enantioselective analysis of methadone in sweat as monitored by liquid chromatography/ion spray-mass spectrometry.

In recent years, remarkable advances in sensitive analytical techniques have enabled the analysis of drugs in unconventional samples, such as sweat. In a study conducted during a methadone maintenance program, PharmChek sweat patches were applied to 20 subjects. The subjects were orally administered methadone in 1 dosage/day, and doses ranged from 80 to 100 mg. The sweat patch was applied 10 minutes before administration and removed 72 hours later just before a new administration of methadone. The absorbent pad was stored at -20 degrees C until analysis in plastic tubes. Methadone was extracted in 5 ml methanol in presence of 200 ng of racemic methadone-d3, used as internal standard. After a 30-minute agitation, the methanol solution was evaporated to dryness. Enantioselective separation of methadone was obtained using an alpha-1-acid glycoprotein column (100 x 4 mm ID) and liquid chromatography/ion spray-mass spectrometry. In all 20 specimens obtained from subjects under racemic methadone treatment, R- (the active form) and S-enantiomers of methadone were identified with the following concentrations: 26 to 1118 ng/patch for R-methadone and 28 to 1114 ng/patch for S-methadone. The ratio between R- and S-methadone was in the range of 0.72 to 2.66 and was higher than 1.00 in 15 samples. No correlation between the doses of methadone administered and the concentrations of methadone in sweat was observed.

Chromatography, High Pressure Liquid↗
PubMed1997

High-performance liquid chromatography-ionspray mass spectrometry for the specific determination of digoxin and some related cardiac glycosides in human plasma.

An original method based upon high-performance liquid chromatography coupled to ionspray mass spectrometry (HPLC-ISP-MS) has been developed for the identification and quantification in plasma of several cardiac glycosides, namely digoxin, digitoxin, lanatoside C and acetyldigitoxin. After single-step liquid-liquid extraction by chloroform-2-propanol (95:5, v/v) at pH 9.5 using oleandrin as an internal standard, solutes are separated on a 4 microm NovaPak C18 (Waters) column (150x2.0 mm, I.D.), using a gradient of acetonitrile-2 mM NH4COOH, pH 3 buffer (flow-rate 200 microl/min, post-column split 1:3). Detection is done by a Perkin-Elmer Sciex API-100 mass analyzer equipped with an ISP interface. In most instances the major ion observed is not [M+H]+ as expected, but [M+NH4]+. The mean retention times (min) are: lanatoside C, 5.74; digoxin, 6.00; digitoxin, 8.08, oleandrin, 8.30, acetyldigitoxin, 8.66 and 9.01 (isomers alpha and beta, respectively). The lower limits of detection in single ion monitoring mode range from 0.15 ng/ml (alpha- and beta-acetyldigitoxin) to 0.60 ng/ml (lanatoside C), making the method less sensitive than radioimmunoassay, whereas it is much more specific.

Acetyldigitoxins↗
PubMed1997

HPLC/MS determination of buprenorphine and norbuprenorphine in biological fluids and hair samples.

An original method, based upon HPLC (high performance liquid chromatography)/Ionspray-MS, has been developed for the identification of buprenorphine (BUP) and norbuprenorphine (norBUP) in biological fluids and hair samples. Biological fluids (2 mL) are extracted at pH 8.4 by CHCl3/2-propanol/n-heptane (25:10:65, v/v) after addition of deuterated BUP (BUP-d4, 10 ng). Hair samples (40 mg) are extracted in the same conditions after decontamination by CH2Cl2, mechanical pulverization, addition of BUP-d4 (1 ng), acidic incubation (1 mL 0.1 N HCl, 56 degrees C overnight), then neutralization by NaOH. Analytes are separated on a 4-microns NovaPak C18 (Waters) column (150 by 2.0 mm, ID) with a mobile phase of acetonitrile/2 mM NH4COOH buffer, pH 3.0 (80:20, v/v; flow rate 200 microL/min; post column split 1:3). Detection is done by a Perkin-Elmer Sciex API-100 mass analyzer equipped with an ISP interface (nebulizing and curtain gas:99.95-% N2; main settings: orifice + 50 V, electron multiplier + 2400 V). The mean retention times for BUP, BUP-d4, and norBUP are 5.84, 5.79, and 4.42 min, respectively. For all compounds, mass spectra exhibit a unique, protonated molecular ion [M + H]+ at m/z 414 (norBUP), 468 (BUP), and 472 (BUP-d4), without any significant fragmentation. The lower limits of detection are 0.10 and 0.05 ng/mL blood, and 4 and 2 pg/mg hair for BUP and norBUP, respectively. BUP and norBUP concentrations measured in hair from six addicts under substitutive therapy by BUP ranged from 4 to 140 pg/mg, and from nondetected to 67 pg/mg, respectively. The good performances of this method in terms of both sensitivity and specificity make it a convenient alternative to HPLC/coulometry and GC/MS for the separate analysis of BUP and norBUP in biological samples.

Adult↗
PubMed1997

Enantioselective separation of methadone and its main metabolite in human hair by liquid chromatography/ion spray-mass spectrometry.

Optical isomers exhibit significant differences in their affinities for receptor sites, biotransformation and binding to serum and tissue proteins. Methadone has been used for the substitution of heroin addicts since 1964. The racemic form is used, i.e., a mixture of the biologically active R-form and the practically inactive S-form. To investigate methadone distribution, a chiral separation of the isomers was developed in human hair samples. The method involves decontamination of hair with water and acetone, pulverization in a ball mill, enzymatic hydrolysis in presence of deuterated internal standards, solid-phase extraction, and liquid chromatography/ion spray-mass spectrometry. Enantioselective separation of methadone and its main metabolite, EDDP, was obtained using an alpha1-acid glycoprotein column (100 by 4 mm ID). In all nine specimens obtained from subjects under racemic methadone treatment in a detoxification center, R- and S-enantiomers of methadone and EDDP were identified with the following concentrations: 2.58-10.22, 1.89-9.53, 0.42-1.73, and 0.40-2.10 ng/mg for R-methadone, S-methadone, R-EDDP, and S-EDDP, respectively. Results are suggestive of a predominance of the Renantiomer of methadone in human hair.

Chromatography, Liquid↗
PubMed1996

Headspace GC/MS testing for chlorodifluoromethane in two fatal cases.

Two cases of lethal poisoning due to chlorodifluoromethane (Freon 22) inhalation are described. The fluorocarbon was determined in biological tissues by headspace gas chromatography/mass spectrometry. Ions monitored were m/z 67, 86 and 51, the latter being used for quantification. Blood concentrations were 26.0 and 37.1 microliters/ml. In both cases, the drug was also identified in urine, vitreous humor and bile, but in much lower concentrations.

Accidents, Occupational↗
PubMed1996

High-performance liquid chromatography coupled to ion spray mass spectrometry for the determination of colchicine at ppb levels in human biofluids.

An original method based upon high-performance liquid chromatography coupled to ion spray mass spectrometry (HPLC-ISP-MS) has been developed for the identification and quantification of colchicine (COL) in human blood, plasma or urine. After single-step liquid-liquid extraction by dichloromethane at pH 8.0 using tofisopam (TOF) as an internal standard, solutes are separated on a 5-microns C18 Microbore (Alltech) column (250 x 1.0 mm, I.D.), using acetonitrile-2 mM NH4COOH, pH 3 buffer (75: 25, v/v) as the mobile phase (flow-rate 50 microliters/min). Detection is done by a Perkin-Elmer Sciex API-100 mass analyzer equipped with a ISP interface (nebulizing and curtain gas: N2, quality U; main settings: ISP, +4.0 kV; OR, +50 V; Q0, -10 V; Q1, -13 V; electron multiplier, +2.2 kV); MS data are collected as either total ion current (TIC, m/z 100-500 or 380-405), or selected ion monitoring (SIM) at m/z 400 and 383 for COL and TOF, respectively. COL mass spectrum shows a prominent molecular ion [M + H]+ at m/z 400. Increasing OR potential fails to provide a significant fragmentation. Retention times are 2.70 and 4.53 min for COL and TOF, respectively. The quantification method shows a good linearity (r = 0.998) over a concentration range from 5 to 200 ng/ml. The lower limit of detection in SIM mode is 0.6 ng/ml COL, making the method convenient for both clinical and forensic purposes.

Anti-Anxiety Agents↗
PubMed1996

Sweat testing in opioid users with a sweat patch.

For many years, toxicologists have detected the presence of drugs of abuse in biological materials using blood or urine. In recent years, remarkable advances in sensitive analytical techniques have enabled the analysis of drugs in unconventional samples such as sweat. In a study conducted in a detoxification center, sweat patches were applied to 20 known heroin abusers. Subjects wore the patch with minimal discomfort for five days. During the same period, two urine specimens were also collected. Target drugs analyzed either by gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-mass spectrometry (LC-MS) included opiates (heroin, 6-monoacetylmorphine, morphine, codeine), cocaine (cocaine, benzoylecgonine, ecgonine methyl ester), delta 9-tetrahydrocannabinol, benzodiazepines (nordiazepam, oxazepam), amphetamines (amphetamine, methamphetamine, methylenedioxyamphetamine [MDA], methylenedioxymethamphetamine [MDMA], methylenedioxyethylamphetamine [MDEA]), and buprenorphine. Patches were positive for opiates in 12 cases. Heroin (37-175 ng/patch) and/or 6-acetylmorphine (60-2386 ng/patch) were identified in eight cases, and codeine exposure (67-4018 ng/patch) was determined in four cases. When detected, heroin was always present in lower concentrations than 6-acetylmorphine, which was the major analyte found in sweat. Cocaine (324 ng/patch) and metabolites were found in only one case. delta 9-Tetrahydrocannabinol (4-38 ng/patch) was identified in nine cases. Benzodiazepine concentrations were very low, ranging from 2 to 44 and from 2 to 15 ng/patch for nordiazepam and oxazepam, respectively. MDEA (121 ng/patch) and its metabolite, MDA (22 ng/patch), were detected in one case. Buprenorphine, which was administered as therapy under close medical supervision, was detected in the range 1.3-153.2 ng/patch with no apparent relationship between the daily dose and amount excreted in sweat. All the urine tests were consistent with the sweat findings, but to identify the same drugs it was necessary to test two urine specimens along with only one sweat specimen. It was concluded that sweat testing appears to offer the advantage of being a relatively noninvasive means of obtaining a cumulative estimate of drug exposure over the period of a week. This new technology may find useful applications in the treatment and monitoring of substance abusers, as the patch provides a long-term continuous monitor of drug exposure or noncompliance.

Amphetamines↗
PubMed1996

Continuous river monitoring of the diatoms in the diagnosis of drowning.

The diagnosis of drowning is one of the most difficult in forensic pathology. Diatom analysis has been proposed to provide supportive evidence of drowning but the reliability and applicability of quantitative and qualitative diatom analysis in the diagnosis of drowning is still disputed in the literature. In order to further examine such cases, the authors report the development of a water monitoring system based on algae performed each month at three aquatic locations where drowning victims are frequently found. Water samples and stones were taken from the surface and from the bed of the river. This protocol was performed during 1993 with analyses both on water samples and human tissue samples (30 bodies). The diatom profile of the drowning sites was compared with the tissue analysis. The extraction of diatoms from the tissues was performed with an enzymatic digestion method using Proteinase K. Results indicate that the monitoring of river diatom populations is an accurate method of generating profiles of the river flora, which can then be compared with the diatom genera found in tissues.

Diatoms↗
PubMed1996

Sweat testing for benzodiazepines.

Thirteen subjects participated in a clinical study to determine the cumulative excretion, the time course, the dose-concentration relationship, and concentrations of diazepam in sweat following oral administration of single dose of the drug. Nordiazepam and oxazepam, two metabolites of diazepam, were also investigated. Sweat was collected by means of Sudormed sweat patch. Patches were removed at specified times over one week and drug content was determined by gas chromatography/mass spectrometry (GC/MS) in negative chemical ionization mode using deuterated internal standards. Irrespective of the time of collection, diazepam and nordiazepam were present, but oxazepam was never detected. Drugs were detectable in the 2 to 4-h period following the administration. Peaks of diazepam were obtained during the 48 to 72-h period. After the peak, a decrease of drug concentration was observed. Concentrations were in the range from 0.1 to 6.0 ng/patch for both drugs. After single administration of diazepam (10, 20, or 30 mg), drugs monitored in three groups of three subjects were suggestive to be dose related. All these data suggest that the sweat patch technology can be useful to document drug use over a week-long period of surveillance.

Administration, Oral↗
PubMed1995

Determination of manganese in human brain samples.

A method is presented for the determination of manganese (Mn) in human tissue samples (especially brain) by graphite furnace atomic absorption spectrophometry (GFAAS). After complete digestion by a mixture of concentrated nitric acid (HNO3)/concentrated perchloric acid (HClO4) (50:50, v/v), the samples are assayed on a Perkin-Elmer 5100 PC apparatus, equipped with transversal graphite tubes and a Mn-specific hollow cathode lamp. The furnace conditions are as follows (for each step: temperature (degree C)/ramp (s)/duration (s)) dry 120/1/40; char 1200/5/10; atomization 2250/0/4; pyrolysis 2400/1/1. Zeeman correction is employed. The method is linear over the range 0.05 to 5.00 micrograms/g wet tissue, and the limit of detection for Mn is about 0.01 microgram/g wet tissue. This simple and rapid method may be of value for the post-mortem assessment of Mn accumulation in brain structures due to occupational or iatrogenic exposure. An application is presented in which elevated levels of Mn were determined in the brain samples of a 63-year-old female deceased after long-term total parenteral nutrition involving Mn supplementation.

Brain Chemistry↗
PubMed1995

A fatal dothiepin overdose.

High pressure liquid chromatography coupled to photodiode array detector and capillary gas chromatography coupled to mass spectrometry were employed to quantify dothiepin in biological fluids, tissues and hair in a death attributed to oral dothiepin (Prothiaden) ingestion. The blood concentration of dothiepin was 5.75 mg/l. Hair analysis clearly indicated a chronic antidepressant exposure, with a dothiepin concentration of 1.89 ng/mg hair. Results are discussed in the light of the existing literature.

Adult↗
PubMed1995

Simultaneous determination of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine and 3,4-methylenedioxymethamphetamine in human hair by gas chromatography-mass spectrometry.

A procedure is presented for the simultaneous identification and quantification of amphetamine (AP), methamphetamine (MA), methylenedioxyamphetamine (MDA) and methylenedioxymethamphetamine (MDMA) in human hair. The method involves decontamination of hair with dichloromethane and warm water, heat-alkaline hydrolysis in the presence of deuterated internal standards, liquid-liquid extraction and gas chromatography-mass spectrometry after derivatization with pentafluoropropionic anhydride-pentafluoropropanol. The limit of detection for AP, MA and MDA was 0.05 ng/mg using a 50-mg hair sample; for MDMA it was 0.1 ng/mg. Coefficients of variation ranged from 7 to 18%. This assay has been successfully utilized in the evaluation of the deposition of the drugs in hair obtained from various parts of the anatomy of a stimulant abuser.

3,4-Methylenedioxyamphetamine↗
PubMed1995

A fatal case of buflomedil self-poisoning: toxicological data and literature review.

A fatal case of buflomedil (Fonzylane) self-poisoning is presented. Drug identification and quantification in postmortem blood, urine and gastric contents was achieved by means of high pressure liquid chromatography with diode-array detection (HPLC/DAD). Blood concentration was 275 micrograms/ml, > 70 times the usual therapeutic values. Toxicological results are discussed in the light of the existing literature.

Adrenergic alpha-Antagonists↗
PubMed1995

Hair analysis: a worthless tool for therapeutic compliance monitoring.

Hair analysis has been presented by some authors as a possible tool of investigation for estimating patients' compliance to long-term therapies. This paper summarises the different publications that have been devoted to this topic and highlights the available statistically data presented to support this proposition. Qualitative results of such determinations may be of some interest but due to the enormous interindividual variations of quantitative data, the idea of using hair analysis to ascertain whether a patient has taken his treatment exactly as prescribed, clearly appears to be inapplicable.

Hair↗
PubMed1995

Fatal zipeprol intoxication.

A fatality resulting from ingestion of zipeprol is described. Capillary gas chromatography coupled to mass spectrometry was employed to quantify the drug in biological fluids and tissues. The femoral blood concentration of the drug was 2.85 mg/L. Hair analysis clearly indicated chronic drug abuse with a concentration of 7.34 ng/mg. Results are discussed in the light of the existing literature.

Adult↗
PubMed1995

Characterization of dextromoramide (Palfium) abuse by hair analysis in a denied case.

By providing information on exposure to drugs over time, hair analysis is useful in verifying the history of drug use. In a clinical case, where drug abuse was denied, it was possible to identify dextromoramide in the hair of the subject. After acid hydrolysis of the hair with 0.1 M HCl, in the presence of SKF 525A as an internal standard, the drug was extracted at pH 8.4 with chloroform-isopropanol-n-heptane (50:17:33 v/v) and quantified by gas chromatography/mass spectrometry. The hair strands were cut into 3 sections of 2.5 cm, corresponding to a growth period of 2 months. Concentrations were 1.09, 1.93 and 1.48 ng/mg from the root to the end, respectively. This is the first report on dextromoramide testing in human hair.

Dextromoramide↗