Evaluation of amphetamines diffusion in hair after contact with amphetamines-containing blood.

Amphetamine-type stimulants are the third most widely consumed category of illicit drugs worldwide. Faced with the growing problem of amphetamine-type stimulants, numerous qualitative and quantitative techniques have been developed to detect amphetamine (AMP), methamphetamine (MET), MDMA, MDEA or MDA in biological matrices, including hair. Hair analysis is widely used in forensic medicine, but one of its main drawbacks remains external contamination. In this study, we investigated the possibility of hair contamination through external exposure to blood containing AMP, MET MDMA, MDEA or MDA at 2 ng/mL; 20 ng/mL; 200 ng/mL or 2000 ng/mL after 6 h, 1, 3, 7 or 14 days of contact protected from light at room temperature (RT or 20 °C) or at 4 °C. Dried extracts of hair samples were analyzed by UPLC-MS/MS after extensive washings in several baths of water, methanol and acetone before grounding. At the end of our study, contamination of hair was observed from 6 h of contact with all tested amphetamine-type stimulants. The concentrations found in hair ranged from 3 ± 1 to 1464 ± 10 pg/mg, 5 ± 1 to 5070 ± 160 pg/mg, 3 ± 1 to 1269 ± 60 pg/mg, 4 ± 1 to 1860 ± 113 pg/mg and from 8 ± 1 to 1041 ± 44 pg/mg for AMP, MET, MDMA, MDEA and MDA, respectively. Possibly due to its low polar surface area, MET was the most prone to contaminate. As anticipated, hair contamination was mainly dependent on the concentration of all molecules in the contaminating blood, reaching the SOHT cut-off of 200 pg/mg when amphetamine-type stimulants are at toxic or lethal concentrations in the blood. These observations call for caution in interpreting exposure to these substances in such forensic situations.

In vitro stability study of 10 beta-lactam antibiotics in human plasma samples.

BACKGROUND AND OBJECTIVES: Beta-lactam antibiotics are reported for some of them to be subject to a rapid degradation in infusion solutions and in human blood samples. However, the current data of stability available in blood samples are limited to a few number of beta-lactam antibiotics, and the methodology of the corresponding studies may be discussed. The objective of the present study is to evaluate the stability of 10 beta-lactam antibiotics in human plasma samples. METHODS: Stability of amoxicillin, cefazolin, cefepime, cefotaxime, cefoxitin, ceftazidime, ceftriaxone, imipenem, meropenem, and piperacillin was evaluated at low and high concentrations at 20°C, 4°C, -20°C, and -80°C for 1, 7, 60, and 90 days, respectively. RESULTS: Amoxicillin, cefepime, meropenem, and piperacillin were the least stable antibiotics. The maximum durations allowing the stability for all the evaluated beta-lactams at both tested concentrations were estimated at 3 h, 23 h, 10 days, and 35 days at 20°C, 4°C, -20°C, and -80°C, respectively. CONCLUSION: We recommend to transport antibiotic plasma samples in ice at 4°C and even at -20°C if these samples come from external hospitals. Ideally, plasma samples should be stored at -80°C if possible; if not, the analysis of the samples should be performed as soon as possible in the limit of 10 days after a storage at -20°C.

Online SPE UPLC-MS/MS method for the simultaneous determination of 33 psychoactive drugs from swab-collected human oral fluid samples.

Oral fluid is easy and safe to collect and allows the detection of drugs of abuse after local exposure by oral, smoked, and/or inhaled intake, or systemic exposure. A routine online solid-phase extraction UPLC-MS/MS method was developed for the simultaneous determination of 33 psychoactive drugs in oral fluid. The selected drugs were fourteen fentanyl analogs and nineteen other abused psychoactive compounds, including classical narcotics, which were analyzed in a run of 10 min. Limits of detection and of quantification ranged from 0.02 to 1 ng/mL and from 0.02 to 5 ng/mL depending on the analyte, respectively. Matrix effect was in the range - 17 to + 15.7% for all analytes having a deuterated analog. Accuracy ranged from 82.7 to 113.4% and precision CV was at worst of 18.6%. Carryover was below 0.8% for all analytes. Recovery from FLOQSwabs™ showed high variability between analytes with THC, D2FF, 4-ANPP, ocfentanil, and valerylfentanyl being recovered below 40%. A stability study performed over 2 weeks on collecting devices loaded with artificial oral fluid showed huge variation between analytes with morphine, BZE, and norfentanyl being the more stable. Storage at 4 °C allowed drug detection for 1 week except for THC and remifentanil. The method was successfully applied to the detection of abused psychoactive compounds in oral fluid samples from 6 patients admitted to an addiction department.

Multiplex detection of 14 fentanyl analogues and U-47700 in biological samples: Application to a panel of French hospitalized patients.

Synthetic opioids (SO) associated with the recent alarming increase of deaths and intoxications in United States of America and Europe are not detected by the usual first-line opiates drug screening assays. We developed a liquid chromatography tandem mass spectrometry analytical method for the multiplex detection of 14 fentanyl analogues (2-furanylfentanyl, 4-ANPP, 4-methoxybutyrylfentanyl, acrylfentanyl, alfentanil, carfentanil, despropionyl-2-fluorofentanyl, fentanyl, methoxyacetylfentanyl, norfentanyl, ocfentanil, remifentanil, sufentanil and valerylfentanyl) and U-47700 in whole blood and urine samples. The method was validated according to the requirements of ISO 15189. A simple and fast liquid-liquid extraction (LLE) with De-Tox Tube-A was performed leading to better recovery of molecules in urine than in blood samples. Depending on the compound, the limits of detection (LODs) ranged from 0.01 to 0.10 ng/mL and from 0.02 to 0.05 ng/mL in whole blood and urine, respectively. Calibration curves were linear in the range 0.5-50.0 ng/mL and the limit of quantification (LOQ) ranged from 0.10 to 0.40 ng/mL in blood. Internal quality controls at 1 and 40 ng/mL showed intra-day and between-day precision and accuracy bias below 10% in urine and 15% in blood. The method was applied to the screening of 211 urine samples from patients admitted in emergency or addiction departments. The presence of legal fentanyl analogues in 5 urine samples was justified by their therapeutic use as analgesics. Only one patient was concerned by fentanyl misuse and addiction whereas no illegal SO was detected. This study is not in favor of a huge misuse of SO in the Lorraine region.

Temocillin dosage adjustment in a preterm infant with severe renal disease: a case report.

BACKGROUND: Temocillin is a carboxypenicillin antibiotic indicated in complicated urinary tract infections due to susceptible ESBL-producing Enterobacteriaceae. While temocillin therapeutic schemes for adult patients with normal or impaired renal function are evidence based, little is known in paediatric populations. OBJECTIVES: We report herein the management of temocillin treatment in a preterm infant with end-stage renal disease. PATIENTS AND METHODS: The patient was a 7-month-old preterm infant born at 35 weeks gestation and treated by temocillin for 10 days for a bacteraemic urinary tract infection due to a susceptible ESBL-producing Enterobacter cloacae complex strain. Temocillin was administered by continuous infusion using a loading dose of 25 mg followed by a maintenance dose of 70 mg daily. Determination of MIC and temocillin plasma and urinary concentration was performed. RESULTS: Clinical improvement was observed 24 h after the initiation of temocillin treatment. Temocillin concentrations ranged between 21.6 and 35.5 mg/L in urine between the first and the sixth day of treatment and between 47.0 and 61.8 mg/L in plasma after 6 and 10 days of treatment, respectively. Temocillin concentrations were found to be above the determined MIC of 6 mg/L. From the measured concentrations, we can postulate that 100%fT>MIC was achieved in urine and at least equal to 40% in plasma. CONCLUSIONS: Temocillin dosing adjustment performed in the present reported case allowed safe and effective treatment. The strategy described herein could be used as a basis for further clinical studies relative to temocillin use in a paediatric population with renal impairment.

A 1-week extension of a ketogenic diet provides a further decrease in myocardial 18F-FDG uptake and a high detectability of myocarditis with FDG-PET.

BACKGROUND: Short periods of fasting and/or low-carbohydrate diet have been proven beneficial for decreasing the myocardial uptake of 18F-fluorodeoxyglucose (18F-FDG) and enhancing the detection of inflammatory heart diseases by 18F-FDG positron emission tomography (PET). This study aimed at determining whether this benefit is increased when a low-carbohydrate ketogenic diet is prolonged up to 7 days. METHODS: Wistar rats underwent serial 18F-FDG-PET imaging after an 18-hour fasting period and after 2, 4 and 7 days of a ketogenic diet (3% carbohydrate) and they were compared to rats submitted to the same protocol but with normal diet (44% carbohydrate). The 18F-FDG-PET/ketogenic protocol was also applied in rats with immune myocarditis (injection of porcine cardiac myosin). RESULTS: The 7-day ketogenic diet was associated with (1) a sustained increase in circulating ketone bodies at an equivalent level to that reached after 18-hour fasting, (2) a gradual decrease in 18F-FDG uptake within normal myocardium reaching a lower level compared to fasting at the 7th day (myocardium-to-blood ratios: 1.68 ± 1.02 vs 3.25 ± 1.40, P < .05) and (3) a high 18F-FDG-PET detectability of myocarditis areas. CONCLUSION: One-week extension of a ketogenic diet provides a further decrease in the 18F-FDG uptake of normal myocardium and a high detectability of inflammatory areas.

Cerebrospinal Fluid Aß42/Aß40 as a Means to Limiting Tube- and Storage-Dependent Pre-Analytical Variability in Clinical Setting.

BACKGROUND: Alzheimer's disease (AD) cerebrospinal fluid (CSF) biomarkers have recently been included in the criteria for AD diagnosis. Unfortunately, their wider use in routine and interpretation require more standardization, particularly for the pre-analytical steps. In particular, amyloid-ß (Aß)42 peptide measurement is strongly influenced by the type of collection tube and by repeated freeze/thaw cycles. OBJECTIVE: The objectives of this study were to compare, in clinical setting, the impact of collection tubes and the repetition of freeze/thaw cycles on Aß42 and Aß40 concentrations and consequently determine if the Aß42/Aß40 ratio could resolve the diagnosis difficulties related to these pre-analytical parameters. METHODS: CSF from 35 patients was collected in different polypropylene (PP) and stored at - 80°C after sampling. For CSF collected in the reference tube, three successive freeze-thaw cycles were done. Aß42 and Aß40 concentrations were determined in each condition in order to calculate the Aß42/Aß40 ratio. RESULTS: Our results showed that CSF Aß42 and Aß40 values were significantly different according to the type of collection tube and the number of freeze/thaw cycles. Although the calculation of the Aß42/Aß40 ratio eliminated the effect of PP tube-dependent variation, this was not the case for freeze-thaw cycle-associated variation. CONCLUSION: The use of Aß42/Aß40 ratio rather than Aß42 alone could contribute toward pre-analytical standardization, thus allowing the general use of CSF AD biomarkers in routine practice.