Search results for "Spectrometry"
showing 10 items of 3206 documents
Case report: Another death associated to γ-hydroxybutyric acid intoxication
2019
Abstract We report a fatal γ-hydroxybutyric acid (GHB) intoxication of a forty-year old man. According to an acquaintances’ statement, the deceased had drunk a beverage containing GHB approximately five hours before he was found. Postmortem GHB concentrations were determined using gas chromatography coupled to single quadrupole mass spectrometry after simple protein precipitation with methanol and derivatization with BSTFA (1% TMCS). Concentrations in body fluids and tissues of the deceased were as follows: cardiac blood 384 mg/L, femoral blood 358 mg/L, urine 864 mg/L, brain tissue 211 mg/kg, liver tissue 201 mg/kg, kidney tissue 492 mg/kg, bile 334 mg/L and gastric content 2025 mg/L. In a…
GHB related acids (dihydroxy butyric acids, glycolic acid) can help in the interpretation of post mortem GHB results.
2020
Post mortem gamma hydroxy butyric acid (GHB) concentrations should be interpreted with caution since GHB concentrations can increase after death. Post mortem concentrations after the intake of GHB ante mortem do overlap with concentration ranges in cases without known exposure to GHB and make an interpretation challenging. GHB is known to undergo intensive metabolism to related acids (glycolic acid (GA), succinic acid (SA), 2,4- and 3,4-dihydroxy butyric acid (2,4-OH-BA and 3,4-OH-BA)). GHB and these related acids were analyzed using a validated gas chromatographic mass spectrometric (GC-MS) method after liquid liquid extraction and trimethylsilylation. SA concentrations were not usable pos…
The synthetic cannabinoid 5F-MDMB-PICA: A case series
2020
5F-MDMB-PICA has been detected in products sold on the internet as well as in biological samples since 2016. It is associated with serious adverse health and behavioral effects and even death. Herein we report on twelve cases with proven 5F-MDMB-PICA consumption, including three fatalities, four cases of driving under the influence of drugs and five other criminal acts. In these cases, 5F-MDMB-PICA was detected in postmortem blood or serum. Concentrations ranged from 0.1-16ng/mL. In some blood (serum) and urine samples, the hydrolysis metabolite of 5F-MDMB-PICA (M12) could also be detected. In this case series, co-consumption with other drugs occurred in 9 of 12 cases, most commonly alcohol…
Longitudinal analysis of taurine induced effects on the tear proteome of contact lens wearers and dry eye patients using a RP-RP-Capillary-HPLC-MALDI…
2012
Tear proteomic studies revealed distinct similarities between contact lens wearers and dry eye patients. AMO Complete® multipurpose contact lens cleaning solutions containing taurine seem to have a beneficial effect regarding contact lens induced dry eye. To illuminate the effect of taurine on the tear proteome of contact lens wearers and sicca patients we developed a gel-based RP-RP capillary HPLC-MALDI TOF/TOF MS strategy. Two contact lens wearer groups, one using eye drops containing 0.05% taurine; the other for control physiological NaCl solution were monitored. Also, a third group of sicca patients using taurine solution was studied (N=4 individuals/group). Tear pools of each group at …
Concentrations of 9-Tetrahydrocannabinol and 11-Nor-9-Carboxytetrahydrocannabinol in Blood and Urine After Passive Exposure to Cannabis Smoke in a C…
2010
Cannabinoid concentrations in blood and urine after passive exposure to cannabis smoke under real-life conditions were investigated in this study. Eight healthy volunteers were exposed to cannabis smoke for 3 h in a well-attended coffee shop in Maastricht, Netherlands. An initial blood and urine sample was taken from each volunteer before exposure. Blood samples were taken 1.5, 3.5, 6, and 14 h after start of initial exposure, and urine samples were taken after 3.5, 6, 14, 36, 60, and 84 h. The samples were subjected to immunoassay screening for cannabinoids and analyzed using gas chromatography-mass spectrometry (GC-MS) for Delta(9)-tetrahydrocannabinol (THC), 11-nor-hydroxy-Delta(9)-tetra…
In vitro production of GHB in blood and serum samples under various storage conditions
2011
Abstract The in vitro production of GHB was observed in freshly collected, untreated whole blood samples using glass BD-Vacutainers and polypropylene S-monovettes. GHB concentrations were determined daily over a period of one week and after 3, 6 and 9 weeks again. Furthermore, the GHB concentration in 40 untreated random whole blood samples stored at 4 °C for a longer period of time (10 samples 12 month, 10 samples 24 month and 20 samples 36 month) was also determined. For comparison, the in vitro production of GHB in freshly collected and prepared serum samples was observed. GHB serum concentrations were determined three times over a period of one week and once again after six weeks. Sampl…
Precision and Bias of Target-Controlled Prolonged Propofol Infusion for General Anesthesia and Sedation in Neurosurgical Patients
2018
The aim of this study was to determine the relationship, precision, and bias of a propofol target-controlled infusion (TCI) system during prolonged infusion in neurosurgical patients. We retrospectively included patients undergoing general anesthesia for elective neurosurgical removal of brain tumors and postoperative sedation in the intensive care unit over a period of 3 months. TCI of propofol (Diprifusor - Marsh model) and remifentanil were used for general anesthesia and sedation. We compared propofol blood concentration (Cmeas) measured by liquid chromatography-mass spectroscopy with predicted concentrations (Cpred) by the TCI system at 40 minutes (T0), 2 hours (T1), and 4 hours (T2) a…
Exposure assessment approach through mycotoxin/creatinine ratio evaluation in urine by GC–MS/MS
2014
Abstract In this pilot survey human urine samples were analyzed for presence of 15 mycotoxins and some of their metabolites using a novel urinary multi-mycotoxin GC–MS/MS method following salting-out liquid–liquid extraction. Fifty-four urine samples from children and adults residents in Valencia were analyzed for presence of urinary mycotoxin and expressed in gram of creatinine. Three out of 15 mycotoxins were detected namely, HT-2 toxin, nivalenol and deoxynivalenol (DON). 37 samples showed quantifiable values of mycotoxins. Co-occurrence of these contaminants was also observed in 20.4% of assayed samples. DON was the most frequently detected mycotoxin (68.5%) with mean levels of 23.3 μg/…
Evidence of noncentrosymmetry of human tooth hydroxyapatite crystals
2014
Herein, we investigate human single hydroxyapatite crystals (enamel and dentine) by convergent-beam electron diffraction (CBED) and automated electron-diffraction tomography (ADT). The CBED pattern shows the absence of the mirror plane perpendicular to the c axis leading to the P63 space group instead of the P63 /m space group considered for larger-scale crystals, this is confirmed by ADT. This experimental evidence is of prime importance for understanding the morphogenesis and the architectural organization of calcified tissues.
A fatal paramethoxymethamphetamine intoxication.
2003
During the last years in Germany a marked increase in the use of amphetamines such as 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) has been observed. The use of these recreational drugs is especially common among young people participating in rave parties. Occasionally ring-methoxylated phenethylamine derivatives like paramethoxymethamphetamine (PMMA) or paramethoxyamphetamine (PMA) are found in street drugs offered as ecstasy. These compounds exhibit a higher toxicity than the methylenedioxyamphetamine derivatives. We report on the death of a 22-year-old man after the ingestion of ecstasy pills containing PMMA and PMA. The PMMA concentration in femoral blood was 0.85 mg/l. Besides PMA…