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Biomedical subjects

B Ludes

Publications and source records attributed to B Ludes.

At least 37 records · Page 2Linked to original sources
PubMed2002

Determination of blood cyanide by HPLC-MS.

An original high-performance liquid chromatographic-mass spectrometric (HPLC-MS) procedure was developed for the determination of cyanide (CN) in whole blood. After the addition of K13C15N as internal standard, blood was placed in a microdiffusion device, the inner well of which was filled with a mixture of taurine (50mM in water)/naphthalene-2,3-dicarboxaldehyde (NDA, 10mM in methanol)/methanol/ concentrated (approximately 20%) ammonia solution (25:25:45:5, v/v). Concentrated H2SO4 was added to the blood sample, and the microdiffusion chamber was sealed. After 30 min of gentle agitation, 2 microL of the contents of the inner vial were pipetted and directly injected onto a NovaPak C18 HPLC column. Separation was performed by a gradient of acetonitrile in 2mM NH4COOH, pH 3.0 buffer (35-80% in 10 min). Detection was done with a Perkin-Elmer Sciex API-100 mass analyzer with an ionspray interface, operated in the negative ionization mode. MS data were collected as either TIC or SIM at m/z (299 + 191) and (301 + 193) for the derivatives formed with CN and 13C15N, respectively. Inspired by previous works dealing with the complexation of CN by NDA + taurine to form a 1-cyano [f] benzoisoindole derivative analyzed by HPLC-fluorimetry, this method appears simple, rapid, and extremely specific. Limits of detection and quantitation for blood CN are 5 and 15 ng/mL, respectively. The use of 13C15N as internal standard allows the quantitation of CN with elegance and accuracy in comparison with previously reported methods.

Chromatography, High Pressure Liquid↗
PubMed2002

Blood investigation in a fatality involving the veterinary drug T-61.

A case involving an acute fatality resulting from self-administration of about 30 mL of T-61, a euthanasia solution, consisting of a mixture of embutramide, mebezonium, and tetracaine, in a 58-year-old veterinarian is presented. Forensic investigations consisted of an external body examination, during which 5 mL of fluorinated femoral blood was collected. Embutramide and tetracaine were quantitated using gas chromatography coupled to mass spectrometry after extraction with chloroform/isopropanol/n-heptane (50:17:33, v/v) at pH 9.5 and separation on an HP5-MS capillary column. Mebezonium was quantitated using liquid chromatography coupled to mass spectrometry after ion-pair extraction (saturated KI solution) with methylene chloride at pH 5.4 and separation on a 5-mm Nucleosil C18 column. Blood concentrations were 43.0, 6.5, and 0.21 mg/L for embutramide, mebezonium, and tetracaine, respectively. No other drugs, including ethanol, were detected.

Amides↗
PubMed2002

Fatal overdosage with sildenafil citrate (Viagra): first report and review of the literature.

A fatal case of sildenafil citrate (Viagra) overdosage is presented. The deceased was a 56-year old male found dead at home, with a past history of diabetes mellitus, hypertension, chronic alcoholism, anxio-depressive disorders, and erectile dysfunction. The main autopsy findings were cardiomegaly (650 g) with dilated cardiomyopathy, diffuse coronary atherosclerosis with no sign of acute ischaemic disease, and extensive fibrosis of the myocardium, especially affecting the cardiac conducting tissue. As measured by HPLC/MS, sildenafil concentration in postrmortem blood (6.27 microg/mL) exceeded at least four times the highest therapeutic levels previously reported. The results are discussed in the light of the literature about the cardiovascular side effects of sildenafil, with special emphasis on the recently evidenced arrhythmogenic potential of the drug. This is the first report of a fatality caused by sildenafil overdosage.

Alcoholism↗
PubMed2002

[Crime under the influence of psychoactive drugs: the problem of the duration of detection].

On a regular basis, the media presents the potential risks of the use of psycho-active compounds, including misused pharmaceuticals (flunitrazepam, GHB) or drugs of abuse (cannabis, LSD, ecstasy). Ethanol is also frequently encountered. These drugs can be used for recreational purposes by addicts or can be observed after sexual assaults (drugs spiked in food). Forensic toxicology can be involved in several situations to document impairment, such as: crime under influence, date rape, driving under influence, psychiatric disorders, determination of the cause of death... In some particular situations, it can be very cautious to investigate exposure to psycho-active drugs, due to late sampling of biological specimens. To enhance the window of detection of 3 specific drugs, the authors propose the following: 1. Use of an ultra-sensitive technique, such as GC/MS/MS/NCI for 7-aminoflunitrazepam; 2. Use of a cumulative specimen, such as sweat for GHB and 3. Use of a metabolite with a long half-life, such as ethyl glucuronide for ethanol.

Cause of Death↗
PubMed2002

[Rapid determination of propofol in biological specimens and hair by HS-GC/MS].

This paper proposes an original method for the determination of propofol in biological specimens. For example, hair specimens are cut into small pieces and incubated overnight in Soerensen buffer at 40 degrees C. After headspace preparation of the biological specimens spiked with tetrahydrofurane (internal standard), the analytes are transferred to the gas chromatograph and separated on a HP Wax capillary column. Detection is achieved in SIM mode (propofol: m/z 117, 163 and 178) on a mass spectrometer operating in electronic impact mode. The developed procedure is easy (full-automated), rapid (no extraction- or derivatization-step), sensible and accurate. After validation of the analytical method (linearity, extraction recovery, repeatability, limit of detection), this new procedure was applied to forensic cases.

Anesthetics, Intravenous↗
PubMed2002

Hair analysis of seven bodybuilders for anabolic steroids, ephedrine, and clenbuterol.

Several bodybuilders, all winners of international competitions, were arrested for trafficking of a number of doping agents including anabolic steroids, ephedrine, beta-adrenergics, human chorionic gonadotropin, antidepressants, and diuretics. In accordance with the recent French law against doping, the judge asked to test seven bodybuilders to identify doping practices. Hair and urine specimens were collected for analysis. After decontamination, a 100 mg hair strand was pulverized in a ball mill, hydrolyzed, extracted, and derivatized to be tested by GC/MS for anabolic steroids, beta-adrenergic compounds, ephedrine, and other doping agents. Urine was analyzed for anabolic steroids and metabolites, beta-adrenergic compounds, ephedrine, and human chorionic gonadotropin, in addition to a broad spectrum screening with GC/MS. The following compounds were detected in urine: ephedrine (29 and 36 ng/mL, n = 2), clenbuterol (0.2 to 0.3 ng/mL, n = 3), norandrosterone (4.7 to 100.7 ng/mL, n = 7), norethiocholanolone (0.9 to 161.8 ng/mL, n = 6), stanozolol (1 to 25.8 ng/mL, n = 4), methenolone (2.5 to 29.7 ng/mL, n = 4), testosterone (3 to 59.6 ng/mL, n = 7), epitestosterone (1 to 20.4 ng/mL, n = 7) and ratio testosterone/epitestosterone >6 for four subjects (18.5 to 59.6). The following drugs were detected in hair: ephedrine (0.67 and 10.70 ng/mg, n = 2), salbutamol (15 to 31 pg/mg, n = 3), clenbuterol (15 to 122 pg/mg, n = 6), nandrolone (1 to 7.5 pg/mg, n = 3), stanozolol (2 to 84 pg/mg, n = 4), methenolone (17 and 34 ng/ml, n = 2), testosterone enanthate (0.6 to 18.8 ng/mg, n = 5), and testosterone cypionate (3.3 to 4.8 ng/mg, n = 2). These results document the doping practice and demonstrate repetitive exposure to anabolic compounds and confirm the value of hair analysis as a complement to urinalysis in the control of doping practice.

Adult↗
PubMed2001

Fatal blunt pancreatic trauma secondary to assault and battery: a case report.

The authors report on an fatal case of closed trauma of the pancreas in a context of violence. A 55-year-old man was found unconscious on the sidewalk and died a short time after being taken to the hospital. He had been hit with several punches to the face and abdomen 6 h before. The post-mortem examination showed numerous bruises over the whole body, a haemoperitoneum, a fissuration of the spleen and a massive peripancreatic haemorrhage associated with a complete dilaceration of the pancreas head. Histological examination of the pancreas revealed a massive necrosis associated with a subtotal disappearance of the acini, numerous sites of cytosteatonecrosis and a large haemorrhagic suffusion of the peripancreatic tissue. This case illustrates the possibilities of pancreatic injuries induced by blunt force aimed at the abdomen in a context of violence. Even if this occurs as an isolated injury it can result in rapid death because of the particular type of pancreatic fracture which is frequently involved. In postmortem situations, the pancreas should be systematically checked at necropsy and a histological examination should be carried out at the slightest doubt of a pancreatic lesion or suspicion of blunt force abdominal injuries.

Fatal Outcome↗
PubMed2001

Doping control for nandrolone using hair analysis.

A sensitive, specific and reproducible method for the quantitative determination of nandrolone in human hair has been developed. The sample preparation involved a decontamination step of the hair with methylene chloride. The hair sample (about 100 mg) was solubilized in 1 ml NaOH IN, 15 min at 95 degrees C, in presence of 10 ng nandrolone-d(3) used as an internal standard. The homogenate was neutralized and extracted using consecutively a solid phase (Isolute C18) and a liquid--liquid (pentane) extraction. The residue was derivatized by adding 50 microl MSTFA/NH4I/2-mercaptoethanol (1000:2:5; v/v/v), then incubated for 20 min at 60 degrees C. A 4-microl aliquot of the derivatized extract was injected into the column (HP5-MS capillary column, 5% phenyl--95% methylsiloxane, 30 m x 0.25 mm i.d. x 0.25 mm film thickness) of a Hewlett Packard (Palo Alto, CA) gas chromatograph (6890 Series) via a Hewlett Packard (7673) autosampler. The assay was capable of detecting 0.5 pg of nandrolone per mg of hair when approximately 100 mg of hair were processed. Linearity was observed for nandrolone concentrations ranging from 1 to 50 pg/mg with a correlation coefficient of 0.997. Intra-day and between-day precisions at 10 pg/mg were 11.2 and 15.1%, respectively, with an extraction recovery of 81.7%. The analysis of three strands of hair, obtained from three bodybuilders, revealed the presence of nandrolone at the concentration of 1, 3.5 and 7.5 pg/mg.

Doping in Sports↗
PubMed2001

Repeated measurements of aldicarb in blood and urine in a case of nonfatal poisoning.

A nonfatal case of poisoning involving aldicarb, an extremely toxic carbamate pesticide, is presented. A 39-year-old female ingested an unknown amount of aldicarb, together with alprazolam and sertraline. On admission to ICU (T0), she displayed marked cholinergic symptoms and a deep coma. The patient was given pralidoxime and atropine. Her condition gradually improved on days 2 and 3 and she was discharged at T0+80 h. Aldicarb was assayed by high-performance liquid chromatography on 21 blood and 8 urine samples successively taken during hospitalization. At the same time, serum pseudocholinesterase activity was followed on 21 successive samples. Blood aldicarb level was 3.11 microg/mL at T0 and peaked at T0+3.5 h (3.22 microg/mL), then followed a two-slope decay with a terminal half-life of ca. 20 h. Aldicarb was detected in all urine samples (peak level: 6.95 microg/mL at T0+31.5 h) and was still present at the time of discharge. Serum pseudo-cholinesterase activity remained low (< or = 10% of normal) until the 30th hour then rapidly increased and returned to normal after the 60th hour. The patient's clinical picture closely followed blood aldicarb levels and serum pseudo-cholinesterase activities. To our knowledge, this is the first report of an aldicarb poisoning documented by repeated measurements of the drug in the intoxicated person.

Adult↗
PubMed2000

Molecular identification by "suicide PCR" of Yersinia pestis as the agent of medieval black death.

Medieval Black Death is believed to have killed up to one-third of the Western European population during the 14th century. It was identified as plague at this time, but recently the causative organism was debated because no definitive evidence has been obtained to confirm the role of Yersinia pestis as the agent of plague. We obtained the teeth of a child and two adults from a 14th century grave in France, disrupted them to obtain the pulp, and applied the new "suicide PCR" protocol in which the primers are used only once. There were no positive controls: Neither Yersinia nor Yersinia DNA were introduced in the laboratory. A negative result is followed by a new test using other primers; a positive result is followed by sequencing. The second and third primer pair used, coding for a part of the pla gene, generated amplicons whose sequence confirmed that it was Y. pestis in 1 tooth from the child and 19/19 teeth from the adults. Negative controls were negative. Attempts to detect the putative alternative etiologic agents Bacillus anthracis and Rickettsia prowazekii failed. Suicide PCR avoids any risk of contamination as it uses a single-shot primer-its specificity is absolute. We believe that we can end the controversy: Medieval Black Death was plague.

Adult↗
PubMed2000

[Drug tests on 198 drivers involved in an accident].

OBJECTIVES: A prospective analytical study was performed in a large population of drivers implicated in traffic accidents to determine the significance of drug levels observed in blood, urine, saliva and sweat and which assays are best to perform in each sample. METHODS: Samples of blood (7.5 ml), urine (10-20 ml), saliva (salivette Sarstedt) and sweat (cosmetic pad spiked with water-isopropanol) were systematically collected in drivers implicated in non-fatal traffic accidents from March to November 1999. The samples were tested for pharmaceuticals (barbiturates, benzodiazepines, anti-depressants, neuroleptics, antiepileptics and antihistamines) and for drugs of abuse by hyphenated chromatographic methods (LC/DAD, GC/MS and LC/MS). RESULTS: A total of 198 drivers (bicycle, motorbike, car, truck) were tested (age range 13-57 years, 82% males). Blood alcohol was positive in 27 cases (13.7%), ranging from 0.11 to 3.19 g/l (mean 1.49 g/l), being > 0.5 g/l in 21 cases. Cannabis was the most frequently observed illicit drug (9.6% of the cases). Its formal pharmacological effect could only be documented by blood testing using GC/MS. Even in the hospital setting, urine collection was difficult. In 16% of the cases, this fluid was missing. Parent compounds were excreted in both saliva and sweat. On-site devices devoted to urine and metabolites were inapplicable. Concentrations in sweat and saliva were very low, particularly for benzodiazepines and cannabis. There was also a risk of external contamination for sweat. CONCLUSION: Saliva might be a good substitution fluid for blood for sample taking on the road side.

Accidents, Traffic↗
PubMed2000

Testing of the anabolic stanozolol in human hair by gas chromatography-negative ion chemical ionization mass spectrometry.

A sensitive, specific and reproducible method for the quantitative determination of stanozolol in human hair has been developed. The sample preparation involved a decontamination step of the hair with methylene chloride and the sonication in methanol of 100 mg of powdered hair for 2 h. After elimination of the solvent, the hair sample was solubilized in 1 ml 1 M NaOH, 15 min at 95 degrees C, in the presence of 10 ng stanozolol-d3 used as internal standard. The homogenate was neutralized and extracted using consecutively a solid-phase (Isolute C18) and a liquid-liquid (pentane) extraction. After evaporation of the final organic phase, the dry extract was derivatized using 40 microl MBHFA-TMSI (1000:20, v/v), incubated for 5 min at 80 degrees C, followed by 10 microl of MBHFBA, incubated for 30 min at 80 degrees C. The derivatized extract was analyzed by a Hewlett-Packard GC-MS system with a 5989 B Engine operating in the negative chemical ionization mode of detection. Linearity of the detector response was observed for stanozolol concentrations ranging from 5 to 200 pg/mg with a correlation coefficient of 0.998. The assay was capable of detecting 2 pg of stanozolol per mg of hair when approximately 100 mg hair material was processed, with a quantification limit set at 5 pg/mg. Intra-day precision was 5.9% at 50 pg/mg and 7.8% at 25 pg/mg with extraction recoveries of 79.8 and 75.1%, respectively. The analysis of a 3-cm long hair strand, obtained from a young bodybuilder (27 year old) assuming to be a regular user of Winstrol (stanozolol, 2 mg), revealed the presence of stanozolol at the concentration of 15 pg/mg.

Adult↗
PubMed2000

Clozapine dose-concentration relationships in plasma, hair and sweat specimens of schizophrenic patients.

The aim of the present study was to establish an analytical method for the determination of clozapine in sweat and to determine whether the clozapine level in hair and sweat were correlated to the daily dose of clozapine delivered to patients. Twenty-six subjects treated with clozapine at 200-700 mg/day for refractory psychosis were included in the study. Clozapine was determined in plasma by liquid chromatography coupled to a diode array detection system, after extraction with an organic solvent at pH 9.5. Clozapine was extracted from hair and sweat patches specimens by incubation in methanol overnight at 40 degrees C. The residues were analyzed by gas chromatography coupled to mass spectrometry in the electronic impact mode of detection. It was possible to determine clozapine in concentrations ranging from 30 to 1016 ng/ml in plasma (n = 22), from 0.17 to 34.24 ng/mg in hair (n = 23) and from 49 to 5609 ng/patch in sweat (n = 20). Preliminary results suggest a lack of correlation between daily regimen of clozapine and plasma levels of the drug. Therefore, a better dose-concentration relationship was observed in our study between daily dose and hair concentration (r = 0.542, P < 7%) or between daily dose and sweat concentration (r = 0.589, P < 6%), but with wide variations for patients at the same posology. However, the idea of using quantitative drug measurements in hair or sweat to ascertain whether a patient has taken his treatment exactly as prescribed will remain inapplicable.

Antipsychotic Agents↗
PubMed2000

Pharmacological criteria that can affect the detection of doping agents in hair.

When positive drug results are reported, a common interpretive question posed is whether or not it is possible to put a quantitative finding into context. A standard answer to this inquiry is that a positive hair testing result can be interpreted as meaning that the donor has chronically or repetitively used the drug identified in the hair, but that chronic or repetitive are not defined in the same way for all individuals. The Society of Hair Testing published on June 16, 1999, a consensus opinion on the use of hair in doping situations. However, although accepted in most courts of justice, hair analysis is not yet recognised by the International Olympic Committee. To be considered as a valid specimen for doping control, some issues still need to be addressed. The scientific community has demonstrated significant concern over the proper role that hair drug testing should serve in toxicological applications. Among the unanswered questions, five are of critical importance: (1) What is the minimal amount of drug detectable in hair after administration? (2) What is the relationship between the amount of the drug used and the concentration of the drug or its metabolites in hair? (3) What is the influence of hair color? (4) Is there any racial bias in hair testing? (5) What is the influence of cosmetic treatments? The present report documents scientific findings on these questions, with particular attention to the applications of hair in doping control.

Anabolic Agents↗
PubMed2000

Identification of ten corticosteroids in human hair by liquid chromatography-ionspray mass spectrometry.

This paper describes a screening procedure based upon high-performance liquid chromatography-ionspray mass spectrometry for the identification of ten corticosteroids in human hair: triamcinolone, prednisolone, prednisone, methylprednisolone, cortisone, cortisol, beta- and dexamethasone, flumethasone and beclomethasone. Hair strands were washed in methylene chloride, pulverized in a ball mill and 50 mg of the powdered hair were incubated in 1 ml Soerensen buffer, pH 7.6 for 16 h at 40 degrees C, in presence of 50 ng cortisol-d3 used as internal standard. Purification of the incubation medium was achieved on SPE C18 Isolute extraction columns. The eluates were evaporated to dryness and resuspended in 30 microliters MeOH before analysis by HPLC-IS-MS in positive and negative modes of detection. The validation parameters were found satisfactory for a corticosteroid screening procedure. The correlation coefficient of the calibration curve ranged from 0.939 to 0.997, showing linearity between 0.1 and 10 ng/mg, excepted for beclomethasone which was between 0.2 and 10 ng/mg. Extraction recovery at 4 ng/mg ranged from 43.2 to 85.7%. Repeatability (CV values) at 4 ng/mg ranged from 6.1 to 17.5%. The limits of detection ranged from 0.03 to 0.17 ng/mg for a signal-to-noise ratio of 2. The detection of prednisone and beclomethasone in three hair specimens obtained from forensic and clinical cases have documented corticosteroids incorporation into human hair.

Adrenal Cortex Hormones↗
PubMed2000

The distribution of laudanosine in tissues after death from atracurium injection.

A case is presented involving an acute fatality resulting from self-administration of atracurium, a muscle relaxant by a 45-year-old nurse. In the body, atracurium undergoes a spontaneous non-enzymatic degradation to laudanosine and an acrylate moiety. Laudanosine was quantified using gas chromatography coupled to mass spectrometry after extraction with chloroform-isopropanol-n-heptane (50:17:33 v/v) at pH 9.5 and separation on a HP5-MS capillary column. Laudanosine was subject to postmortem redistribution due to release from drug-rich tissues such as the lung and heart. The heart blood (917 ng/ml) to peripheral blood (390 ng/ml) ratio was 2.4. No other drugs, including ethanol were detected.

Atracurium↗