How to treat proximal and middle one-third humeral shaft fractures: the role of helical plates

PURPOSE

To evaluate the outcomes of patients affected by proximal and middle one-third humeral shaft fractures treated with humeral helical plates.

MATERIAL AND METHODS

From October 2016 to June 2020, twenty-four (twenty women, four men) underwent humeral reduction and fixation with humeral helical plates (A.L.P.S.® Proximal Humeral Plating System, Zimmer Biomet) that preserve deltoid muscle insertion and reduce the risk of iatrogenic radial nerve injury. At one and six months after surgery, standard antero-posterior and lateral radiographs were obtained, and at last follow-up (eighteen months on average), clinical evaluation was performed through range of motion assessment, Constant score and DASH score questionnaires. Only descriptive statistical analysis was conducted.

RESULTS

At six months, all fractures have healed. At last follow-up (average eighteen months, 13-28) mean Constant score was 71 (range 33-96), mean Dash score was 19.2 (range 1.7-63). The average range of motion was calculated as follows: flexion 137.8° (range 90-180); abduction 125.8° (range 85-180°); external rotation 55° (range 20-80°), internal rotation at L3 (range between scapulae-trochanter). Three patients experienced temporary radial nerve palsy from injury, while in one case, a temporary iatrogenic palsy occurred.

CONCLUSIONS

In our opinion, the helical plate may be an effective surgical tool for management of proximal and middle one-third diaphyseal humeral fractures. The humeral helical plate allows stable fixation avoiding the deltoid tuberosity proximally and radial nerve distally, thus increasing the possibility of rapid functional recovery after surgery.

Aerobic and anaerobic energy production in juvenile roach (Rutilus rutilus): regulation of glycolytic process by ethofumesate at two temperatures

The aim of this study was to evaluate the coupled impact of an herbicide, ethofumesate, and temperature on the cellular energy metabolism of juvenile roach, especially on the glycolysis pathway. Juvenile roach were exposed to 0, 0.5, 5, and 50 μg/L of ethofumesate for 7 days in laboratory conditions at two temperatures (10 and 17 °C). The energy reserves (carbohydrate, lipid, and protein) were quantified, since the availability of substrates regulates the glycolysis. Then, the glycolysis was studied at the biochemical level by the measurement of the glycolytic flux and at the molecular level with the measurement of the relative expression of four genes encoding for glycolysis enzymes. This study revealed different effect of ethofumesate on the glycolysis pathway according to the temperature of exposure. Indeed, at 10 °C, it appeared that only the molecular regulation level was affected, whereas, at 17 °C, ethofumesate acted on the biochemical level. The differences observed between the two exposures imply the establishment of different strategies in order to maintain to cope with stress according to the temperature of exposure.

Effect of ethofumesate herbicide on energy metabolism in roach (Rutilus rutilus)

Not available

Energy metabolism and pesticides: biochemical and molecular responses to copper in roach Rutilus rutilus

Not available

Chemical submission to commit robbery: a series of involuntary intoxications with flunitrazepam in Asian travellers in Brussels

Between January 17, 2003 and August 29, 2003, the Emergency Department admitted a patient who had been surreptitiously intoxicated and robbed of his valuables every Friday. The first cases were considered anecdotal, but criminal activity was rapidly suspected. The cohort includes 16 male Asian patients aged 28-50 years. All the victims had just arrived in Brussels through one of the main rail station of the town and were admitted via the emergency ambulance service from different locations in the centre of Brussels around the CHU Saint-Pierre Hospital. Haemodynamic parameters upon admission were within normal limits. The Glasgow Coma Scale was equal or higher than 9/15 in 14 of the 16 victims. Toxicology screening obtained in 12 patients revealed the presence of flunitrazepam, which was further quantified at levels ranging from 21 to 75 μg/l. One of the Japanese patients, who returned to Belgium afterwards for professional reasons, was approached by the police and accepted to press charges. This allowed the police to investigate and send undercover agents to the railway station on Friday afternoons and evenings. They found a person who was offering welcome cookies to Asian travellers. He arrived from Amsterdam and returned once his crime was committed. Flunitrazepam is well known as a rape drug. We report a series of victims in whom flunitrazepam was used to facilitate robbery.

Bio-analysis of forensically relevant drugs in alternative matrices by liquid chromatography-tandem mass spectrometry

Cannabis is the most frequently detected illicit drug in the Western world, e.g. in cases of driving under the influence of drugs (DUID), whereas benzodiazepines comprise the most abused licit drugs and have been linked with drug-facilitated sexual assault cases (DFSA). In recent years, remarkable advances in sensitive analytical techniques have enabled the analysis of drugs in alternative matrices such as oral fluid and hair. These specimens allow easy, non-invasive sampling, which can be achieved under close supervision to prevent adulteration or substitution of the samples. The volume is often limited and to achieve the required analytical sensitivity, liquid chromatography-tandem mass spectrometry (LC-MS-MS) methods for the detection of cannabis and benzodiazepines in oral fluid and hair were developed. After validation, these methods were applied to genuine samples to assess: (a) the validity of oral fluid to detect recent cannabis consumption, (b) the Dräger Drug Test as an on-site oral fluid test, and (c) the applicability of hair testing in forensic cases. The latter led to new insights into metabolic conversions between benzodiazepines; this knowledge may avoid potentially erratic conclusions regarding DFSA. Finally, benzodiazepines are also frequently encountered in post-mortem cases. An LCMS-MS method to detect benzodiazepines in larvae and puparia of insects rearing on corpses was developed and validated. In conclusion, this research aimed at combining the usefulness of alternative matrices with the analytical power of LC-MS-MS. Final outcome is a number of sensitive and validated methods ready for use in routine analysis.

High-throughput on-line solid-phase extraction–liquid chromatography–tandem mass spectrometry method for the simultaneous analysis of 14 antidepressants and their metabolites in plasma

A rapid, sensitive and fully automated on-line solid-phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) method was developed and validated for the direct analysis of 14 antidepressants and their metabolites in plasma. Integration of the sample extraction and LC separation into a single system permitted direct injection of the plasma without prior sample pre-treatment. The applied gradient ensured the elution of all the examined drugs within 14 min and produced chromatographic peaks of acceptable symmetry. The total process time was 20 min and only 50 microL of plasma was required. Selectivity of the method was achieved by a combination of retention time and two precursor-product ion transitions for the non-deuterated compounds. The use of SPE was demonstrated to be highly effective and led to significant decreases in the interferences present in the matrix. Extraction was found to be both reproducible and efficient with recoveries >99% for all the analytes. The method showed excellent intra-assay and inter-assay precision (relative standard deviation (RSD) and bias <20%) for quality control (QC) samples spiked at a concentration of 40, 200 and 800 microg/L and the r2>0.99 over the range investigated (10-1000 microg/L). Limits of quantification (LOQs) were estimated to be 10 microg/L. Furthermore, the processed samples were demonstrated to be stable for at least 48 h, except for clomipramine and norclomipramine, where a slight negative trend was observed, but did not compromise the quantification. The method was subsequently applied to authentic samples previously screened by a routine HPLC method with diode array detection (DAD).

Detection of diazepam in urine, hair and preserved oral fluid samples with LC-MS-MS after single and repeated administration of Myolastan® and Valium®

Sedative agents are used to facilitate sexual assault due to their ability to render the victim passive, submissive and unable to resist. The primary pharmacological effect of the benzodiazepine tetrazepam is muscle relaxation, whereas the benzodiazepine diazepam acts on the central nervous system (CNS) exerting mainly sedation effects. Therefore, contrary to tetrazepam, diazepam is an often-abused drug, which can potentially be used as a date-rape drug. In this study, we describe the detection of low amounts of diazepam in Myolastan (Sanofi-Synthelabo S.A., Brussels, Belgium) and Epsipam (Will-Pharma, Wavre, Belgium) 50 mg tablet preparations by LC-MS-MS, GC-FID and HPLC-DAD. Considering the important forensic implication of this finding, a study was conducted with volunteers receiving a single or repeated dosage of Myolastan. Urine, hair and preserved oral fluid samples were analysed using a previously described sensitive and specific LC-MS-MS detection method allowing for the simultaneous quantification of tetrazepam, diazepam, nordiazepam, oxazepam and temazepam. This study demonstrates that diazepam can be observed in urine samples even after a single dose of Myolastan. In addition, maintaining therapy for 1 week results in the detection of both diazepam and nordiazepam in urine samples and of diazepam in the first hair segment. Importantly, comparing urine and hair samples after a single intake of diazepam versus the single and 1 week administration of Myolastan shows that the possible metabolic conversion of tetrazepam to diazepam is a more plausible explanation for the detection of diazepam in biological samples after the intake of Myolastan. As such, these results reveal that the presence of diazepam and/or nordiazepam in biological samples from alleged drug-facilitated assault cases should be interpreted with care.

New [99mTc]bombesin analogues with improved biodistribution for targeting gastrin releasing-peptide receptor-positive tumors

AIM

Bombesin (BBS) receptors are potential targets for diagnosis and therapy of breast and prostate tumors. To overcome the rapid degradation of natural BBS some modifications were introduced at positions 13 and 14. Additionally, a spacer was inserted between the chelator and the binding sequence in order to further improve the in vivo uptake. The analogues were labeled with the [(99m)Tc(CO)(3)]-core and tested.

METHODS

Stability was analyzed in vitro in human plasma. Binding affinity and internalization were determined in vitro in prostate carcinoma PC-3 cells. Biodistribution studies and single photon emission computed tomography/X-ray computed tomography (SPECT/CT) imaging were performed in nude mice with PC-3 tumor xenografts.

RESULTS

The changes introduced in the BBS(7-14) sequence substantially increased plasma stability. Affinity for gastrin releasing-peptide (GRP) receptors on PC-3 cells was comparable to that of the unmodified analogue with Kd<1 nM. The presence of a spacer in the molecule induced an increment in the in vivo uptake in pancreas and PC-3 xenografts (GRP receptor-positive tissues). The increase in pancreas and tumor uptake was higher when both spacer and stabilization are present in the same molecule. Moreover, in vivo uptake was highly specific. The tumor was clearly visualized by SPECT/CT.

CONCLUSIONS

The modifications in the BBS(7-14) sequence led to a higher plasma stability while binding affinity remained unaffected. Stabilization resulted in improved biodistribution with better tumor to non-tumor ratios. However, the insertion of a spacer had a greater influence on the biodistribution. Analogues with both spacer and stabilization are the most promising radiopharmaceuticals for targeting GRP receptor-positive tumors.

Correlation of Delta9-tetrahydrocannabinol concentrations determined by LC-MS-MS in oral fluid and plasma from impaired drivers and evaluation of the on-site Dräger DrugTest

Oral fluid (collected with the Intercept((R)) device) and plasma samples were obtained from 139 individuals suspected of driving under the influence of drugs and analyzed for Delta(9)-tetrahydrocannabinol (THC), the major psychoactive constituent of cannabis, using a validated quantitative LC-MS-MS method. The first aim of the study was to investigate the correlation between the analytical data obtained in the plasma and oral fluid samples, to evaluate the use of oral fluid as a 'predictor' of actual cannabis influence. The results of the study indicated a good accuracy when comparing THC detection in oral fluid and plasma (84.9-95.7% depending on the cut-off used for plasma analysis). ROC curve analysis was subsequently used to determine the optimal cut-off value for THC in oral fluid with plasma as reference sample, in order to 'predict' a positive plasma result for THC. When using the LOQ of the method for plasma (0.5 ng/mL), the optimal cut-off was 1.2 ng/mL THC in oral fluid (sensitivity, 94.7%; specificity, 92.0%). When using the legal cut-off in Belgium for driving under the influence in plasma (2 ng/mL), an optimal cut-off value of 5.2 ng/mL THC in oral fluid (sensitivity, 91.6%; specificity, 88.6%) was observed. In the second part of the study, the performance of the on-site Dräger DrugTest for the screening of THC in oral fluid during roadside controls was assessed by comparison with the corresponding LC-MS-MS results in plasma and oral fluid. Since the accuracy was always less than 66%, we do not recommend this Dräger DrugTest system for the on-site screening of THC in oral fluid.

Validation of a Liquid Chromatography-Tandem Mass Spectrometry Method for the Simultaneous Determination of 26 Benzodiazepines and Metabolites, Zolpidem and Zopiclone, in Blood, Urine, and Hair

A liquid chromatography-tandem mass spectrometry method was developed for the simultaneous quantification of 26 benzodiazepines and metabolites, zolpidem and zopiclone, in blood, urine, and hair. Drugs were extracted from all matrices by liquid-liquid extraction with 1-chlorobutane. Chromatography was achieved using a XTerra MS C18 column eluted with a mixture of methanol and formate buffer. Data were acquired using positive electrospray ionization and multiple reaction monitoring using one precursor ion/product ion transition per compound. Quantification was performed using 13 deuterated analogues. Further confirmation of the identity of the compounds was achieved through a second injection of positive samples, monitoring two transitions per compound. The limits of quantification for all benzodiazepines ranged from 1 to 2 ng/mL in blood, 10 to 25 ng/mL in urine, and 0.5 to 10 pg/mg in hair. Linearity was observed from the limit of quantification of each compound to 200 ng/mL, 1000 ng/mL, and 1000 pg/mg for blood, urine, and hair, respectively (r2 > 0.99). Precision for quality control samples, spiked at three concentrations, was calculated (CV < 20% in most cases). Extraction recoveries for the three matrices ranged from 25.1 to 103.8%, except for one compound (cloxazolam in urine). Ion suppression was studied for all matrices. The validated assay was applied to authentic blood, urine, and hair samples from forensic cases.

Validation of an ELISA-based screening assay for the detection of amphetamine, MDMA and MDA in blood and oral fluid

The use of amphetamine and 'ecstasy' (MDMA) has increased exponentially in many European countries since the late nineties, leading to a rapid growth in the number of clinical and forensic analyses. Therefore, a rapid screening procedure for these substances in biological specimens has become an important part of routine toxicological analysis in forensic laboratories. The objective of this study was to evaluate the Cozart amphetamine enzyme-linked immunosorbent assay (ELISA) for the screening of plasma samples and oral fluid samples (collected with the Intercept device). Authentic plasma samples from drivers (n=360) were screened, using an 1:5-fold dilution. True positive, true negative, false positive and false negative results were determined relative to the in-house routine GC-MS analysis. Samples consisted of 144 amphetamine-only positives, 141MDMA/MDA-only positives, and 74 negatives when using the limit of quantitation as the cut-off level for confirmation (10 ng/mL). Using these results, receiver operating characteristic (ROC) curves were generated and optimal cut-off values for the screening assay were calculated. Analysis showed that the ELISA is able to predict the presence of either amphetamine or *MDMA/MDA (*MDMA as its metabolite MDA) in plasma samples with 98.3% sensitivity and 100% specificity at a cut-off value of 66.5 ng/mL d-amphetamine equivalents. A similar analysis was conducted on 216 oral fluid specimens collected from a controlled double blind study. Subjects received placebo or a high (100 mg) or low (75 mg) dose of MDMA. Oral fluid samples were collected at 1.5 and 5.5h after administration. Combined results of the analysis of the high and low dose oral fluid samples indicated a screening cut-off of 51 ng/mL d-amphetamine equivalents with both a sensitivity and specificity of 98.6% (using a LC-MS/MS confirmation cut-off of 10 ng/mL). In conclusion, these data indicate that the Cozart AMP EIA plates constitute a fast and accurate screening technique for the identification of amphetamine and MDMA/MDA positive plasma samples and oral fluid specimens (collected with Intercept. It should be emphasized that method validation should be performed for each type of biological matrix.

Quantitative analysis of Δ9-tetrahydrocannabinol in preserved oral fluid by liquid chromatography–tandem mass spectrometry

A rapid and sensitive method for the analysis of delta9-tetrahydrocannabinol (THC) in preserved oral fluid was developed and fully validated. Oral fluid was collected with the Intercept, a Food and Drug Administration (FDA) approved sampling device that is used on a large scale in the U.S. for workplace drug testing. The method comprised a simple liquid-liquid extraction with hexane, followed by liquid chromatography-tandem mass spectrometry (LC-MS-MS) analysis. Chromatographic separation was achieved using a XTerra MS C18 column, eluted isocratically with 1 mM ammonium formate-methanol (10:90, v/v). Selectivity of the method was achieved by a combination of retention time, and two precursor-product ion transitions. The use of the liquid-liquid extraction was demonstrated to be highly effective and led to significant decreases in the interferences present in the matrix. Validation of the method was performed using both 100 and 500 MicroL of oral fluid. The method was linear over the range investigated (0.5-100 ng/mL and 0. 1-10 ng/mL when 100 and 500 microL, respectively, of oral fluid were used) with an excellent intra-assay and inter-assay precision (relative standard deviations, RSD <6%) for quality control samples spiked at a concentration of 2.5 and 25 ng/mL and 0.5 and 2.5 ng/mL, respectively. Limits of quantification were 0.5 and 0.1 ng/mL when using 100 and 500 microL, respectively. In contrast to existing GC-MS methods, no extensive sample clean-up and time-consuming derivatisation steps were needed. The method was subsequently applied to Intercept samples collected at the roadside and collected during a controlled study with cannabis.

Simultaneous analysis of gamma-hydroxybutyric acid and its precursors in urine using liquid chromatography–tandem mass spectrometry

We have developed a rapid method that enables the simultaneous analysis of gamma-hydroxybutyrate (GHB) and its precursors, i.e. gamma-butyrolactone (GBL) and 1,4-butanediol (1,4-BD) in urine. The method comprised a simple dilution of the urine sample, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Chromatographic separation was achieved using an Atlantis dC18 column, eluted with a mixture of formic acid and methanol. The method was linear from 1-80 mg/L for GHB and 1,4-BD and from 1-50 mg/L for GBL. The limit of quantification was 1 mg/L for all analytes. The procedure, which has a total analysis time (including sample preparation) of less than 12 min, was fully validated and applied to the analysis of 182 authentic urine samples; the results were correlated with a previously published GC-MS procedure and revealed a low prevalence of GHB-positive samples. Since no commercial immunoassay is available for the routine screening of GHB, this simple and rapid method should prove useful to meet the current increased demand for the measurement of GHB and its precursors.

Intentional overdose of Large Animal Immobilon

We describe a case of voluntary self-injection with Large Animal Immobilon, a veterinary anaesthesia product containing etorphine, a very strong opioid, and acepromazine, a phenothiazine. This resulted in cardiorespiratory arrest and the need for sustained haemodynamic support after resuscitation. Large Animal Immobilon is used under specific conditions only, mainly in zoo and wildlife medicine. Primary toxicological analysis, although guided by the presumed toxin, could only detect a metabolite of acepromazine in the urine. Further analysis was able to show some traces of etorphine. A number of topics are treated, including the apparent potency of the etorphine and the selection of a suitable antidote, taking into account the different properties of the respective agents.

Development of a Rapid and Sensitive Method for the Quantitation of Benzodiazepines in Calliphora vicina Larvae and Puparia by LC-MS-MS

Liquid chromatography-tandem mass spectrometry (LC-MS-MS) is emerging as the tool of choice for rapid analysis and the detection of biologically active compounds in complex mixtures. We describe the development of a sensitive method for the simultaneous quantitation of 10 benzodiazepines in Calliphora vicina (Diptera: Calliphoridae) larvae and puparia. The use of larvae for toxicological analyses offers some technical advantages over putrefied tissue. Four sample pretreatment methods for isolating the benzodiazepines out of larvae were evaluated. A simple homogenization, followed by acetonitrile precipitation yielded the highest recoveries. Puparia were pulverized and extracted by ultrasonification in methanol. All extracts were subsequently analyzed using reversed-phase LC-MS-MS. Larvae and puparia calibrators containing benzodiazepines at concentrations ranging from 25 to 750 pg/mg and 50 to 500 pg/mg, respectively, were prepared and analyzed. The method was demonstrated to be linear over the ranges investigated. Limits of detection were from 1.88 to 5.13 pg/mg larva and from 6.28 to 19.03 pg/mg puparium. The developed method was applied to the determination of nordiazepam and its metabolite oxazepam in larvae and puparia of the Calliphora vicina fly that had been reared on artificial foodstuff (beef heart) spiked with 1 microg/g nordiazepam. The larvae were harvested at day 5 for analysis of drug content. The method was sufficiently sensitive to allow the detection of nordiazepam and oxazepam in a single larva or puparium.

Cobas Mira S endpoint enzymatic assay for plasma formate

In methanol intoxication, increased levels of the metabolite formate are associated with metabolic acidosis and an increased risk for ocular and neurological dysfunction. A simple method for plasma formate measurement by adaptation of a manual enzymatic assay to a Cobas Mira S analyzer is presented. Six microliters of sample is incubated for 5 min with buffer containing nicotinamide-adenine dinucleotide. Fifteen microliters of a suspension of formate dehydrogenase is then added. Absorbance at 340 nm is measured every 25 s. The NADH produced when formate is oxidized is stoichiometric to the amount of formate. The method is sensitive, reproducible, and specific and has a broad measurement range. The frozen reagents are stable for at least six months, so the described method can be applied to irregular and semi-urgent requests. A recent case is reported.

Pharmacokinetic model-driven infusion of sufentanil and midazolam during cardiac surgery: assessment of the prospective predictive accuracy and the quality of anesthesia

OBJECTIVE

To evaluate the prospective predictive accuracy and the quality of anesthesia of pharmacokinetic model-driven infusion of sufentanil and midazolam designed to establish and maintain a plasma level of drug during cardiac surgery.

DESIGN

Prospective analysis.

SETTING

Operating room at a university hospital.

PARTICIPANTS

Twenty adult patients younger than 75 years old scheduled for valvular or coronary artery bypass graft surgery.

INTERVENTIONS

Patients were anesthetized using a variable predicted concentration of sufentanil (1 to 10 ng/mL) combined with a stable predicted concentration of midazolam (100 ng/mL).

MEASUREMENTS AND MAIN RESULTS

For each patient, arterial samples were taken before (6 samples), during (2 samples), and after (2 samples) cardiopulmonary bypass (CPB). Plasma sufentanil and midazolam concentrations were measured by specific radioimmunoassay and high-performance liquid chromatography techniques. Predicted sufentanil and midazolam concentrations were derived using the data sets of Gepts et al and Maitre et al. The predictive performance, the percentage prediction error (PE), and the absolute percentage error were calculated for each sample. The bias, inaccuracy, and dispersion were assessed by determining the median of the individual medians of the prediction errors (MDPE), the median of the individual median of the absolute prediction errors (MDAPE), and the 10th and 90th percentiles of PE. For midazolam, the inaccuracy was low (MDAPE < 21%), but CPB was associated with a dilution of the measured concentration associated with a negative bias. For sufentanil, the inaccuracy was also low before CPB (MDAPE = 18%) but increased during and after CPB (MDAPE > 40%). During the whole procedure, the hemodynamic control necessitated only a few interventions.

CONCLUSIONS

Pharmacokinetic model-driven infusion of sufentanil and midazolam using the pharmacokinetic sets of Gepts et al and Maitre et al is a safe and accurate anesthetic technique before CPB in adult patients undergoing cardiac surgery when high sufentanil (1 to 10 ng/mL) and low midazolam (100 ng/mL) predicted plasma concentrations are targeted.

Orphenadrine poisoning in a child: clinical and analytical data

Orphenadrine is an anticholinergic drug used mainly in the treatment of Parkinson's disease. It has a peripheral and central effect and a known cardiotoxic effect when taken in large doses. We report the successful outcome of the treatment of a 2 1/2-year-old girl who accidentally ingested 400 mg of orphenadrine hydrochloride (Disipal). One hour after ingestion she presented neurological symptoms: confusion, ataxic walking, and periods of severe agitation. Generalized tonic-clonic seizures appeared resistant to the administration of multiple antiepileptics. They ceased after a supplementary dose of intravenous diazepam, endotracheal intubation, and mechanical ventilation. An episode of ventricular tachycardia responded well to i. v. lidocaine. Physostigmine was administered in three successive doses. The initial orphenadrine plasma level (3,55 microg/ml) was in the toxic range, associated with high mortality. The calculated elimination half-life was 10.2 h and the molecule and/or its metabolites were found up to 90 h after ingestion.

Classification of medicines according to their influence on driving ability

Within the scope of an information campaign of the Belgian Institute for Road Safety an attempt was made to classify 179 medicinal drugs from 9 therapeutic groups, listed in the Belgian "Commented Repertory of Drugs--1997", according to their effect on driving performance. The categorisation was based on literature data from about 500 references and used the system proposed by Wolschrijn et al [1]: 7 classes ranging from no effect (I) over minor and moderate (II.1,II.2) to severe effects (III), completed with the respective* categories (I*,II*,III*) for presumed classes with insufficient scientific data. Forty-two drugs (24%) were considered having severe effects (III/III*). Only 28/179 molecules (16%) were classed in I/I*: no hypnotics-sedatives (33), anticonvulsants (10), antidepressants (25), neuroleptics (29), nor narcotic analgesics and antitussives (18) were listed in this no-effect category, while for 7/24 antihistamines (5/20 H1 and 2/4 H2), 12/20 beta blockers and 9/10 central stimulants the effect was considered negligible. Antidiabetics were not classified, as the danger lies in the risk of hypoglycemia due to inadequate use. The classification of the molecules proved to be problematic due to the lack of study data (42% of molecules in presumed categories) and the diversity in the study protocols. The effect on driving ability is dose-dependent and time-related, which makes the use of a single category inadequate; the effect further depends on co-ingestion of other medicines or alcohol, the development of tolerance and the condition of the subject. Physicians and pharmacists can use the proposed categorisation as a scientific base for guiding their patients, but should take into account the factors involved for each patient when estimating the driving ability.

Gitaloxin poisoning in a child

Gitaloxin is a digitalis glycoside used for the same indications as digoxin and digitoxin. The successful outcome for a 2 1/2-year-old boy who accidentally ingested 3 mg of gitaloxin (100 times the normal therapeutic dose) is reported. At admission the child presented with irregular heart rhythm. He subsequently started vomiting, even after continuous gastric feeding. Only 48 h after ingestion of gitaloxin he became somnolent and developed bradyarrhythmia. The symptoms disappeared 96 h later; the bradyarrhythmia, however, (second-degree atrioventricular block) decreased progressively only after 120 h. The initial clinical presentation of gitaloxin poisoning may be misleading and careful observation in a pediatric intensive care unit is mandatory. A cross-reaction between the fluorescence polarization immunoassay for digitoxin and the radioimmunoassay for gitaloxin was found and was used as a helpful, but rough, estimate of the severity of gitaloxin poisoning, in the absence of a specific measurement of gitaloxin.

Automation of toxicological screenings on a Hewlett Packard Chemstation GC-MS system

OBJECTIVES

To optimize the interpretation of GC-MS toxicological screenings (i.e., to facilitate ion specific queries, create custom reports specifically adapted to each confirmation procedure, and eliminate redundant and/or inaccurate data on library search reports).

DESIGN AND METHODS

The MS Chemstation software of the Hewlett Packard 5972 is constructed in a modular way. We made extensive modifications to two modules, the data analysis and the report modules, using the built-in MS Chemstation macro language.

RESULTS

Ion specific queries were automated for over 60 commonly encountered analytes. Custom reports were created for the confirmation of positive drugs-of-abuse immunoassay results. With the incorporation of decision support rules into the data processing and the reporting phases, we obtained sensitive, accurate, and concise reports.

CONCLUSIONS

The MS Chemstation software can be tailored to the needs of each individual application. The incorporation of a rule-based decision support system enhances the quality of the GC-MS toxicological screenings and results in faster, easier, and more reliable processing.

Combined intoxication with a tricyclic antidepressive agent and a neuroleptic

We report the case of a patient who co-ingested a tricyclic antidepressant (2500 mg of doxepin) and a neuroleptic drug (3500 mg of prothipendyl). Following overdose either agent can affect the central nervous and cardiovascular systems, inducing arrhythmias, conduction disturbances and hypotension. The presented case illustrates that a combined overdose of tricyclic antidepressants and neuroleptics enhances the possible toxic effects of each drug and especially the risk for adverse cardiac events. The clinical features and management of this combined intoxication are discussed. Treatment with sodium bicarbonate readily corrected a potentially life-threatening cardiac arrhythmia and is therefore suggested to be imperative in the treatment of these cases.

Positive interference of merthiolate in the TDx digoxin assay in control samples used in the Belgian External Quality Assessment (EQA) Scheme

We investigated the possible origin of the spuriously high results observed with the Abbott TDx Immunoassay in the 1991 Belgian external quality assessment scheme for digoxin. The present work ascribes this discrepancy to a matrix effect induced by the addition of merthiolate as preservative to the control samples. It consequently stresses the importance of avoiding the use of this compound for preparing such samples.

Analytical and clinical evaluation of creatine kinase MB mass assay by IMx: comparison with MB isoenzyme activity and serum myoglobin for early diagnosis of myocardial infarction

We analytically and clinically evaluated Abbott's IMx assay for creatine kinase (CK) isoenzyme MB (CK-MB) in serum. Over a 1-year period, the method was more specific but less precise than catalytic isoenzyme measurements by electrophoresis or immunoinhibition. Sera from different individuals without electrophoretic evidence of CK-MB but containing macro CK type 1 (n = 20), mitochondrial CK (n = 5), or CK-BB (n = 5) were scored as CK-MB negative by the IMx. Likewise, CK-MB-negative by the sera remained so after addition of purified human CK-MM (< or = 7600 U/L) or CK-BB (< or = 8100 U/L). For 39 patients admitted for suspicion of uncomplicated acute myocardial infarction (precordial pain for < or = 4 h), the diagnostic performance of the IMx CK-MB assay on admission and 4 h later was superior to that of total CK activity and compared well with that of CK-MB activity measured by electrophoresis or immunoinhibition. An admission, myoglobin showed a higher diagnostic sensitivity, specificity, and predictive value than did CK-MB and was the most informative test. Diagnostic performance on admission and 4 h later was further improved by considering positivity for myoglobin and for CK-MB by IMx and for the change in each over the first 4 h of hospitalization as criteria. Twelve hours after admission, diagnostic performance was further improved for all CK and CK-MB methods but began to decline for myoglobin.

Analytical and Clinical Evaluation of Creatine Kinase MB Mass Assay by IMx: Comparison with MB Isoenzyme Activity and Serum Myoglobin for Early Diagnosis of Myocardial Infarction

We analytically and clinically evaluated Abbott's IMx assay for creatine kinase (CK) isoenzyme MB (CK-MB) in serum. Over a 1-year period, the method was more specific but less precise than catalytic isoenzyme measurements by electrophoresis or immunoinhibition. Sera from different individuals without electrophoretic evidence of CK-MB but containing macro CK type 1 (n = 20), mitochondrial CK (n = 5), or CK-BB (n = 5) were scored as CK-MB negative by the IMx. Likewise, CK-MB-negative by the sera remained so after addition of purified human CK-MM (&lt; or = 7600 U/L) or CK-BB (&lt; or = 8100 U/L). For 39 patients admitted for suspicion of uncomplicated acute myocardial infarction (precordial pain for &lt; or = 4 h), the diagnostic performance of the IMx CK-MB assay on admission and 4 h later was superior to that of total CK activity and compared well with that of CK-MB activity measured by electrophoresis or immunoinhibition. An admission, myoglobin showed a higher diagnostic sensitivity, specificity, and predictive value than did CK-MB and was the most informative test. Diagnostic performance on admission and 4 h later was further improved by considering positivity for myoglobin and for CK-MB by IMx and for the change in each over the first 4 h of hospitalization as criteria. Twelve hours after admission, diagnostic performance was further improved for all CK and CK-MB methods but began to decline for myoglobin.

Prophylactic diclofenac infusions in major orthopedic surgery: effects on analgesia and acute phase proteins

The influence of diclofenac, given by continuous i.v. infusion starting preoperatively, on postoperative pain and inflammation was assessed in a double-blind, randomized, placebo-controlled study in 40 patients scheduled for major orthopedic surgery. Starting 30 min before induction the patients received either diclofenac (0.35 mg.kg-1 bolus followed by a constant-rate infusion of 90 micrograms.min-1) or placebo for 24 h. The pain intensity (VAS) and the amount of rescue narcotic (piritramide on demand) were significantly lower in the diclofenac group from 4 and 6 h postsurgery, respectively, till end of infusion. Acute phase proteins used as inflammation markers (C-reactive protein, alpha 1-chymotrypsin, alpha 1-acid glycoprotein, haptoglobin and coeruloplasmin) showed similar variations in both groups for 24 h. The diclofenac treatment had no influence on hematological and coagulation profiles, nor on muscle and liver enzymes in comparison with placebo. Both patients and observer rated the diclofenac treatment as significantly superior to the placebo treatment.

Ataxia as the only delayed neurotoxic manifestation of organophosphate insecticide poisoning

A patient is reported presenting a cerebellar disorder developing about 5 weeks after acute exposure to an organophosphate insecticide. Initially no major cholinergic features were observed. The ataxia of delayed onset was not accompanied by clinical or electrophysiological signs of polyneuropathy. The possible pathogenetic mechanisms are reviewed and discussed. This case illustrates the need to closely monitor all patients intoxicated with such chemicals for at least 5 weeks. One should not only keep in mind the well-known late-onset polyneuropathy, but also the less frequent delayed central nervous system effects, even in the milder cases where initial signs of acetylcholine excess are only minimally present or lacking.

Lorazepam fast-dissolving drug formulation (FDDF) and intravenous administrations as anaesthetic premedicants: a pharmacokinetic analysis

The pharmacokinetics of lorazepam premedication were studied in 16 patients using two different formulations (intravenous and FDDF oral administrations). Arterial blood samples were taken at intervals for up to 600 min after administration of 4 mg of each formulation, and plasma lorazepam concentrations were determined by gas-chromatography with electron capture detection. Concentration-time data for individual subjects were analysed by model-independent methods. The derived pharmacokinetic parameters indicated a rapid distribution (median T1/2 lambda 1 i.v. = 15.2 min, median T1/2 lambda 1 oral = 31.6 min) into a steady-state volume of distribution approximating total body water, with a long elimination half-life and a low clearance. Vdss and clearance were similar with both treatments. The absorption of FDDF lorazepam was rapid in half of the patients and provided a high plasma concentration of lorazepam (Cmax = 61.8 ng ml-1) in a short time interval (Tmax = 58 min), but there were considerable inter-individual differences. This variability in absorption might explain why premedication with FDDF lorazepam is sometimes less effective than expected.

The inducing and inhibiting effects of sodium valproate in vivo on the biotransformation systems of xenobiotics in isolated rat hepatocytes

1. The induction and inhibition of some biotransformation enzymes by valproate have been studied in hepatocytes isolated from rats treated with sodium valproate either i.p. or by subcutaneous implantation of osmotic pumps. 2. When valproate was given i.p., the cytochromes P-450 and b5, and aldrin epoxidase and glutathione S-transferase activities were significantly induced. 3. In contrast, valproate administered by osmotic pumps induced 7-ethoxycoumarin-O-deethylase activity, whereas aldrin expoxidase and glutathione S-transferase activities were significantly inhibited. At a valproate serum concentration of about 100 micrograms/ml for 2 weeks a significant induction of the cytochromes P-450 and b5 was observed. 4. Since there is a large difference between the half-lives of valproate in man and rodent, constant-rate delivery of valproate represents a better model for induction studies than i.p. injection.

Meprobamate poisoning, hypotension and the Swan-Ganz catheter

A case is described in which voluntary ingestion of 72 g meprobamate (mpb) was complicated by shock ascribed to cardiac failure and vasodilation, documented by hemodynamic monitoring. Forced diuresis and cardiac inotropic support were added to the therapy. We recommend Swan-Ganz monitoring in any case of mpb overdosage associated with hypotension and suggest that forced diuresis is not contraindicated if appropriate assessment of the patient's hemodynamic condition is performed.

Disposition kinetics of propofol during alfentanil anaesthesia

The pharmacokinetics of a constant rate infusion of propofol were studied in 11 patients who received total intravenous anaesthesia for ENT surgery. Alfentanil was administered as an exponentially decreasing infusion using a computer-assisted infusion device with a constant target plasma alfentanil concentration of 300 ng/ml. Propofol was infused at a constant rate of 6 mg/kg/hours. Plasma alfentanil concentrations were determined by gas chromatography and whole blood propofol concentrations by high-performance liquid chromatography in arterial blood samples collected at selected times during and up to 8 hours after infusion. Pharmacokinetic modelling of the blood propofol concentration-time data indicated that a three-compartment open model with central elimination was most appropriate. Derived pharmacokinetic parameters were in agreement with previous studies on the pharmacokinetics of propofol. The plasma alfentanil concentrations in 10 patients significantly exceeded the expected values at any time during the infusion. The population mean bias amounted to 20.2% (SD 12.6). Only three data sets were significantly underestimated after the infusion was stopped (mean bias 11.9% (SD 25.5]. The elimination half-life of alfentanil was approximately 75 minutes (SD 21). We conclude that alfentanil does not interfere with the pharmacokinetic profile of propofol but that propofol induces higher plasma alfentanil concentrations than expected.

Acute and chronic intoxication with carbromal preparations

An important number of acute intoxications can be ascribed to the abuse of, until now, non-prescription carbromal preparations. Prolonged use of these drugs also leads to chronic intoxication with bromide accumulation. The clinical features and treatment of three suicidal Obral overdoses and of two patients presenting with bromism are presented. Laboratory findings, from admission to recovery, consist of qualitative TLC and quantitative HPLC drug assays in body fluids and the determination in plasma of the two competing ions chloride and bromide. The high frequency of acute intoxications and carbromal induced bromism stresses the need to bring these preparations under prescription.

Bromism after prolonged use of carbromal

Most of the brominated monoureide and bromide salt containing drugs are obtainable in Belgium without prescription. Apart from the regularly encountered suicidal attempts, these drugs can also, without the intention of the patient, cause bromism . We report two cases of patients recently admitted because of bromism after prolonged use of Carbromal . Bromism now has become a rather unfamiliar condition. Therefore diagnostic and therapeutic aspects are briefly discussed. Because we dispose now, for the same indications, of more efficient and much less toxic drugs, we suggest that drugs containing a significant amount of brominated monoureides or bromide salts should be removed from the market.

Fluorimetric analysis of the binding of warfarin to human serum albumin. Equilibrium and kinetic study

Binding of warfarin to human serum albumin results in a red shift of the UV absorption maximum, suggesting that the binding site is a hydrophobic area of the protein. The enhancement of the fluorescence of warfarin upon binding to human serum albumin was used to study the binding equilibrium and the kinetics of this drug-protein interaction. From equilibrium fluorescence measurements, contributions from free and bound warfarin could be evaluated. From the resulting Scatchard plots, equilibrium constants ranging from 4.2 X 10(5) to 3.5 X 10(5) M-1 for temperatures from 8 degrees to 37 degrees were calculated. The reaction is slightly exothermic (delta H = -1.2 kcal m mole-1) and strongly entropy-driven (delta S = +21 cal . mole-1 . K-1). The reaction rate constants of the warfarin-albumin interaction were determined by the stopped-flow technique. The association rate constant varies from 2.2 X 10(5) to 7.7 X 10(5) M-1 sec-1 from 10 degrees to 32 degrees. The corresponding activation enthalpy is 9.0 kcal . mole-1. These values are not consistent with a diffusion-controlled reaction. The dissociation of the complex was studied by making use of the direct competition between warfarin and phenylbutazone for the same binding site. The dissociation rate constant varies from 2.5 to 10.8 sec-1 in the same temperature range. Activation parameters obtained in the kinetic experiments correspond very well with the thermodynamic parameters calculated from the equilibrium study, validating the fluorescence approach to the equilibrium studies.