Asymptomatic hyperuricemia: impact of ultrasonography

Thirty-five patients (23 males) with asymptomatic hyperuricemia for at least two years underwent two-dimensional ultrasonography of knees and ankles. Urate deposits (tophi) in tendons, synovium, and other soft tissues were detected in 12 patients (34%). Increased vascularity (inflammation) was evident in 8 of these patients (23%). Tophi were more frequently found in knees than in ankles and were especially prevalent in the distal patellar tendon. The presence of tophi was unrelated to the known duration of hyperuricemia (mean, 5 years). Ultrasonography allows detection of tophi and inflammation in a third and in a fourth, respectively, of asymptomatic hyperuricemic patients.

A severe case of olanzapine overdose with analytical data

INTRODUCTION

Olanzapine is a second-generation atypical antipsychotic agent approved for the treatment of psychotic disorders and mania. While olanzapine overdoses are common, cases with whole blood concentrations are less so. We describe here a well-documented case of a pure olanzapine overdose in which whole blood concentrations were determined, and compared with other concentrations in the literature.

CASE REPORT

A 58-year-old woman with a 10-year history of paranoid schizophrenia and poor therapeutic compliance was found unconscious with two empty 28-tablet vials of Zyprexa (olanzapine) 10 mg tablets. Her initial vital signs were blood pressure 110/70 mmHg, pulse rate 82 beats/minute (sinus rhythm), respirations 20 breaths/minute, and the Glasgow Coma Scale score was 7. In the Intensive Care Unit, her pulse rate was 160 beats/minute, in sinus rhythm, and QTc 0.423 seconds (normal <0.4 seconds). Relevant analytical findings were metabolic acidosis, leukocytosis, creatine phosphokinase 1992 mg/dL, and glucose 207 mg/dL. Ten hours after being found, her blood sugar was 350 mg/dL and became normal at 25 hours. The patient needed intubation and insulin.

RESULTS

Olanzapine was detected and quantitated by gas chromatography with nitrogen-phosphorus detector and confirmed by gas chromatography-mass spectrometry using a validated analytical method. At approximately 4, 8, and 12 hours post-ingestion, whole blood concentrations of olanzapine were 0.41, 0.34, and 0.38 mg/L, respectively.

CONCLUSIONS

This study reports an acute olanzapine monointoxication with severe toxicity and high whole blood olanzapine concentrations. Clinical and analytical data of similar samples obtained in non-fatal life-threatening cases can be very useful when interpreting postmortem cases.

Modelling adaptative volumetric finite growth in patient-specific residually stressed arteries

Understanding the functional performance of vascular tissue is taking a rising importance due to the increasing impact of cardiovascular diseases in developed countries. Currently available medical imaging acquisition techniques, combined with computer modelling allow patient-specific simulations of customized geometries that may help in medical diagnosis and therapeutic treatment. In this work we show methodology to develop patient-specific simulations. Particular features of arteries such as their multilayered structure, as well as the non-linear behaviour of the arterial tissue are considered. A strategy based on the decomposition of the deformation gradient tensor is followed in order to include residual stresses in the real geometry. By means of this technique, it is also possible to model the adaptative growth of the artery neglecting the developing process from the embryo state.

Reporting a fatality during tumescent liposuction

Deaths of patients during elective surgery have drawn attention to the danger of anesthesia. Tumescent local anesthesia is subcutaneous infiltration of large volumes of dilute lidocaine with epinephrine to produce vasoconstriction while delivering anesthesia over large areas without lidocaine toxicity. This report documents the case of a 38-year-old woman who attended an outpatient clinic to undergo liposuction of the abdomen and bilateral hips and thighs. According to one witness, around 30 min after anesthesia administration, the victim suffered an episode of tonic-clonic convulsion. When the emergency medical services arrived the patient was in asystole. She died in spite of attempted cardiopulmonary resuscitation. The patient had no significant past medical history including no history of allergies or any known complications with anesthesia. A complete autopsy was performed and possible causes of death such as myocardial infarction, aspiration of food or foreign body, and pulmonary embolism were discarded. Anaphylactic shock was considered a possible but unlikely explanation for the fatality. Toxicological analyses revealed the presence of lidocaine and mepivacaine in heart blood, at concentrations of 4.9 and 16.2mg/L, respectively. All drugs involved in the case were detected using gas chromatography with nitrogen-phosphorus detector and confirmed using gas chromatography-mass spectrometry full scan mode after solid-phase extraction using Chem-Elut columns. An additional high-performance liquid chromatography coupled to diode-array detection screening also obtained the same results. Based on the autopsy findings, case history, and toxicology results, the forensic pathologists ruled that the cause of death was an overdose of local anesthetic agents. The Court of Law ruled the death as an involuntary homicide due to gross negligence.

Methylmalonic acidaemia: examination of genotype and biochemical data in 32 patients belonging to mut, cblA or cblB complementation group

Methylmalonic acidaemia (MMA) is a genetic disorder caused by defects in methylmalonyl-CoA mutase or in any of the different proteins involved in the synthesis of adenosylcobalamin. The aim of this work was to examine the biochemical and clinical phenotype of 32 MMA patients according to their genotype, and to study the mutant mRNA stability by real-time PCR analysis. Using cellular and biochemical methods, we classified our patient cohort as having the MMA forms mut (n = 19), cblA (n = 9) and cblB (n = 4). All the mut (0) and some of the cblB patients had the most severe clinical and biochemical manifestations, displaying non-inducible propionate incorporation in the presence of hydroxocobalamin (OHCbl) in vitro and high plasma odd-numbered long-chain fatty acid (OLCFA) concentrations under dietary therapy. In contrast, mut (-) and cblA patients exhibited a milder phenotype with propionate incorporation enhanced by OHCbl and normal OLCFA levels under dietary therapy. No missense mutations identified in the MUT gene, including mut (0) and mut (-) changes, affected mRNA stability. A new sequence variation (c.562G>C) in the MMAA gene was identified. Most of the cblA patients carried premature termination codons (PTC) in both alleles. Interestingly, the transcripts containing the PTC mutations were insensitive to nonsense-mediated decay (NMD).

Computer simulation of damage on distal femoral articular cartilage after meniscectomies

It is commonly accepted that total or partial meniscectomies cause wear of articular cartilages that leads to severe damage in a period of few years. This also produces alteration of the biomechanical environment and increases articular instability, with a progressive and degenerative arthrosic pathology. Due to these negative consequences, total meniscectomy technique has been avoided, with a clear preference for partial meniscectomies. Despite the better results obtained with this latter technique, it has been demonstrated that the knee still suffers progressive long-term wear, which alters the properties of the surface of articular cartilage. In this paper, a phenomenological isotropic damage model of articular cartilage is presented and implemented in a finite element code. We hypothesized that there is a relation between the increase of shear stress and cartilage degeneration. To confirm the hypothesis, the obtained results were compared to experimental ones. It is used to investigate the effect of meniscectomies on articular damage in the human knee joint. Two different situations were compared for the tibio-femoral joint: healthy and after meniscectomy. The distribution of damaged regions and the damage level distribution resulted qualitatively similar to experimental results, showing, for instance that, after meniscectomy, significant degeneration occurs in the lateral compartment. A noteworthy result was that patterns of damage in a total meniscectomy model give better agreement to clinical results when using relative increases in shear stress, rather than an absolute shear stress criterion. The predictions for partial meniscectomies indicated the relative severity of the procedures.

The tissue distribution of fluoride in a fatal case of self-poisoning

The purpose of this paper is to report a case of fluoride poisoning along with a discussion of poisoning characteristics, analytical procedures, and a review of previous reports of fatal intoxications with analytical data. A case of suicidal ingestion of 40 mL of a rust removal agent containing hydrofluoric acid and ammonium fluoride by a 33-year-old white male is presented. He had an organic personality disorder with residual schizophrenia and previous suicide attempts with therapeutic drugs and cleaning products. At admission, he presented with a Glasgow coma score of 3, third degree atrioventricular block, and asystole. Resuscitation efforts were performed during which the patient suffered two episodes of ventricular fibrillation followed by asystole. In spite of advanced resuscitation efforts and the administration of calcium chloride, he died 2.5 h after the ingestion. Analytical data in the hospital showed calcium levels of 3.1 mg/dL and metabolic acidosis. Internal findings were erosive gastritis, brain edema, and pulmonary and hepatic congestion. Quantitation of fluoride was performed using an ion-selective electrode for the anion. Disposition of fluoride in the different tissues was as follows: peripheral blood, 19.4 mg/L; urine, 670 mg/L; vitreous humor, 2.5 mg/L; liver, 40.0 mg/kg; kidney, 60.0 mg/kg; lung, 17.5 mg/kg; brain, 2.5 mg/kg; spleen, 30.0 mg/kg; bone, 0.5 mg/ kg; and gastric content, 1120 mg/L (67 mg total). Validation of the analytical method was performed using different spiked tissues, in a range of concentrations from 2.4 to 475 mg/L or mg/kg, and submitting them to dilution (1:25) to avoid the matrix effect and to bring these concentrations to the range of the aqueous calibration curve (0.19-19 mg/L). Limits of detection and quantitation were 0.02 and 0.1 mg/L, respectively. The linearity of the method, for all studies tissues, was excellent, with r(2) values of 0.999. Accuracy and precision were within 10.5% and 5.7%, respectively. Fluoride analyses using the ion selective electrode are simple, sensitive, and rapid. This report provides an extensive tissue distribution study of fluoride after a well documented case of acute poisoning. Based on the autopsy findings, patient history, toxicology results, and previously reported data the forensic pathologists ruled that the cause of death was due to a fluoride poisoning, and the manner of death was listed as suicide.

Reproducibilidad de la prueba de sobrecarga oral de glucosa en pacientes con glucosa alterada en ayunas

BACKGROUND AND OBJECTIVES

Impaired fasting glucose (IFG) is defined by a fasting glucose between 5.6 and 6.9 mmol/l in subjects with no known diabetes. The present study objectives were: a) to analyze the glucose tolerance test (GTT) reproducibility and b) to assess this test's diagnostic classification agreement.

PATIENTS AND METHOD

Cross-sectional study in adult patients diagnosed with IFG. Study subjects underwent a 75 g GTT in two occasions.

RESULTS

Fifty-nine patients were studied. The interval between GTT tests was 37 +/- 26 days. Fasting and post-GTT plasma glucose intra-individual variation coefficients were 6.9 and 31.0%, respectively. Diagnostic agreement between the two tests (normal tolerance vs. abnormal tolerance) was measured using the kappa index: 0.62 (95% CI 0.42-0.82). Agreement ranged from 80% (95% CI, 70-90%) to 83% (95% CI, 73-93%) depending on whether the first GGT results were abnormal or normal, respectively.

CONCLUSIONS

GTT reproducibility is moderate in patients diagnosed with IFG. Considering this fact, perhaps this test should be repeated before therapeutic decisions are made.

Membrane lipid composition of pancreatic AR42J cells: modification by exposure to different fatty acids

Dietary fat type influences fatty acids in rat pancreatic membranes, in association with modulation of secretory activity and cell signalling in viable acini. We aimed to confirm whether AR42J cells are a valid model to study the interactions between lipids and pancreatic acinar cell function. For this purpose we have (i) compared the baseline fatty acid composition of AR42J cells with that of pancreatic membranes from rats fed a standard chow; (ii) investigated if fatty acids in AR42J membranes can be modified in culture; and (iii) studied if similar compositional variations that can be evoked in rats when dietary fat type is altered occur in AR42J cells. Weaning Wistar rats were fed for 8 weeks either a commercial chow (C) or semi-purified diets containing virgin olive oil (VOO) or sunflower oil (SO) as fat source. AR42J cells were incubated for 72 hrs in medium containing unmodified fetal calf serum (FCS, AR42J-C cells), FCS enriched with 18:1 n-9 (AR42J-O cells), or FCS enriched with 18:2 n-6 (AR42J-L cells). Fatty acids in crude membranes from rat pancreas and AR42J cells were determined by gas-liquid chromatography. Differences in membrane fatty acids between C rats and AR42J-C cells can be explained in part by variations in the amount of fatty acids in the extracellular environment. Supplementation of FCS with 18:1 n-9 or 18:2 n-6 changed the fatty acid spectrum of AR42J cells in a manner that resembles the pattern found, respectively, in VOO and SO rats, although AR42J-L cells were unable to accumulate 20:4 n-6. The AR42J cell line can be a useful tool to assess the effect of membrane compositional changes on acinar cell function. However, differences in baseline characteristics, and perhaps fatty acid metabolism, indicate that results obtained in AR42J cells should be confirmed with experiments in the whole animal.

Treatment with tiludronate has a similar effect to risedronate on Paget's disease activity assessed by bone markers and bone scintigraphy

OBJECTIVE

To compare the effects of tiludronate and risedronate on Paget's disease activity assessed by biochemical markers of bone turnover and quantitative bone scintigraphy.

METHODS

An open-labeled non-randomized study was performed in 49 patients with Paget's disease who had completed treatment with tiludronate (400 mg/d) for 3 months (28 patients) or risedronate (30 mg/d) for 2 months (21 patients). Biochemical markers of bone turnover, including serum total alkaline phosphatase (TAP), bone alkaline phosphatase (BAP), procollagen type I N propeptide (PINP) and urinary N-terminal cross-linking telopeptide of type I collagen (NTX) were measured at baseline and at 6 and 12 months after the end of treatment. Quantitative bone scintigraphy at baseline and 6 months after the end of treatment was performed in all patients obtaining a scintigraphic activity index (SAI).

RESULTS

At baseline there were no significant differences in disease activity between both groups of patients, since markers of bone turnover as well as SAI were similar in both groups. The effects of tiludronate and risedronate in reducing the biochemical markers of bone turnover were comparable at 6 months (tiludronate vs risedronate: TAP -52% vs -43%; BAP -69% vs -56%; PINP -68% vs -63%; NTX -62% vs -59%) and at 12 months after the end of treatment (tiludronate vs risedronate: TAP -47% vs -36%; BAP -57% vs -46%; PINP -57% vs -52%; NTX -51% vs -52%). The effects of tiludronate and risedronate on SAI were also similar 6 months after the discontinuation of treatment. In addition, the percentage of patients who showed normalized serum TAP levels at 6 months after treatment were similar with both agents (74% with tiludronate and 70% with risedronate).

CONCLUSION

Tiludronate and risedronate given at the currently recommended dosages induce similar responses in Paget's disease activity.

Hypophosphatemia in postoperative patients with total parenteral nutrition: influence of nutritional support teams

PURPOSE, SETTING AND SUBJECTS: We conducted a prospective, descriptive study of postoperative patients under total parenteral nutrition controlled by a Multidisciplinary Nutritional Support Team in a tertiary care hospital. Between january 2002 and november 2003. Data of nutritional status, nutritional support, hypophosphatemia, electrolyte and metabolic complications were reviewed.

RESULTS

215 postoperative patients (63.3% male, 68 +/- 13.9 years old, 47.4% neoplasia). were included. Nutritional support according nutritional needs was made during fasting 14.2 +/- 18.4 days. Mild-moderate initial malnutrition was present in 58% of patients. 18.1% developed postoperative hypophosphatemia 96 hours after starting total parenteral nutrition containing phosphate. 37.7% patients showed moderated and 6.5% severe hypophosphatemia. Nutritional intervention corrected hypophosphatemia (p < 0.001). Factors related to hypophosphatemia were hypokalemia, hypomagnesemia, hypercalcemia, female sex, neoplasia, 96-hour postoperative period and duration of nutrition.

CONCLUSIONS

Prevalence of hypophosphatemia in postoperative patients with total parenteral nutrition is high and needs timely monitoring. The intervention of Multidisciplinary Nutritional Support Team is effective detecting and correcting postoperative hypophosphatemia.

Suicidal Inhalation of Motorbike Exhaust: Adding New Data to the Literature about the Contribution of Gasoline in the Cause of Death

We would like to alert toxicologists to the importance of testing for gasoline, and for volatile hydrocarbons in general, in deaths involving inhalation of exhaust fumes occurring in closed spaces with running motors or machinery. We present here a case of suicidal inhalation of motorbike exhaust, a mixture of carbon monoxide (CO) and gasoline vapor, by a 38-year-old female. She was found in her closed home garage with a hose extending from the exhaust pipe of a motorbike through a cellophane plastic device into a closed tent in which the victim lay. She left two suicide notes nearby. The carboxyhemoglobin (COHb) was measured using visible spectrophotometry. The toxicological screening and quantitation of gasoline was performed by means of gas chromatography with flame-ionization detector and confirmation was performed using gas chromatography-mass spectrometry. The %COHb determined in blood was 73%. Gasoline concentrations in heart blood and vitreous humor were 22.3 and 1.0 mg/L, respectively. Although fatalities with CO at this rate are common, we would like to highlight the role of gasoline and add new quantitative data of this toxic substance to the scarce literature. Based upon the toxicological data, along with the information provided by the medical examiner, the cause of death was determined to be CO and gasoline poisoning and the manner of death suicide.

Investigation of a Fatality Due to Diesel Fuel No. 2 Ingestion

This paper presents a simple, rapid, reliable, and validated analytical method suited for forensic examination of diesel fuel No. 2 in biological specimens. The proposed methodology has been applied to the investigation of a forensic case with diesel fuel No. 2 ingestion. Case history and pathological and toxicological findings are described here to illustrate the toxicity of this complex hydrocarbon mixture. The toxicological significance and the possible mechanisms leading to death are also discussed. The toxicological initial screening and quantitation were performed by means of gas chromatography with flame-ionization detection and confirmation was performed using gas chromatography-mass spectrometry in total ion chromatogram mode. n-Tetradecane peak was selected to estimate diesel fuel No. 2 in all biological samples. Diesel fuel No. 2 analytical methodology was validated at five concentration levels from 5 to 400 mg/L. The method provided extraction recoveries between 89.0% and 97.9%. The limit of detection was 1 mg/L and the limit of quantitation was 5 mg/L. The linearity of the blood calibration curves was excellent with r2 values of >0.999. Intraday and interday precisions had a coefficient of variation<or=10.9% in all cases. The case reports the suicide of a 64-year-old female by diesel fuel No. 2 ingestion. Heart blood concentration was 9.1 mg/L, and concentration in the abdominal contents was 3500 mg/L (total amount 8.2 mL). Pathological findings were unusual and consisted of gastric and intestinal lesions reminiscent of effects caused by ingestion of a corrosive agent and the presence of a dark-brownish liquid with strong odor to hydrocarbons. The cause of death was attributed to intoxication with diesel fuel No. 2. The manner of death, according to the case history provided by the medical examiner, was considered suicide. Because there are no other similar references regarding analytical and toxicological data, this article provides with evidence about toxic concentrations and is a useful adjunct to the postmortem toxicological interpretation of fatalities if the decedent has been involved in diesel fuel No. 2 use.

An Unusual Case of Drug-Facilitated Sexual Assault Using Aromatic Solvents

This report documents a case of drug-facilitated sexual assault (DFSA) under the influence of solvents. The victim was a 13-year-old female. Upon contact with law enforcement, she was still confused and could hardly explain the facts. She told authorities that she had been kidnapped 4 h previously when two individuals with covered faces put a cloth soaked in a solvent over her mouth. She spent a few hours in a room, during which she lost consciousness. The girl awakened semi-nude in the street with memory loss. No alcohol was present in the subject's body; no odor of alcohol was detected on the subject's breath. No lesions were observed during a gynecological exam. A blood sample was taken with the intent to investigate the use of chloroform or similar anesthetics. Toxicological analysis of the victim's blood revealed the presence of 7.6 mg/L of benzene, 24.8 mg/L of toluene, and 0.6 mg/L of xylene (mixture of isomers). As for other analytical findings, diazepam (0.02 mg/L) was also found. The aromatic solvents involved in this case were detected using gas chromatography with flame-ionization detection (GC-FID) and confirmed using GC-mass spectrometry (MS) in full scan mode after liquid-liquid extraction of the whole blood sample. Quantitation of the aromatic solvents was carried out using GC-FID. Diazepam was detected using GC with nitrogen-phosphorus detection (NPD) and confirmed using GC-MS with full scan mode after solid-phase extraction of the whole blood sample using Bond-Elut Certify columns. Quantitation of diazepam was carried out using GC-NPD. No other drugs, including ethanol, were detected. Recoveries for benzene, toluene, and xylene (mixture of isomers) in whole blood at 5 mg/L were 89.2%, 90.8%, and 93.4%, respectively. Intraday precisions were 5.3%, 5.0%, and 4.9%, respectively, and interday precisions were 12.1%, 11.6%, and 11.5%, respectively. The limits of detection (LOD) and quantitation (LOQ) were 30 and 100 microg/L, respectively. The linearity of the blood calibration curves was excellent with r(2) values of > 0.999 (range 0.1-10 mg/L). Recovery for diazepam in whole blood at 0.5 mg/L was 88.2% with intraday and interday precisions of 2.0% and 10.8%, respectively. The LOD and LOQ were 6 and 20 microg/L, respectively. The linearity of the blood calibration curve was excellent with r(2) values of > 0.999 (range 0.1-2 mg/L). We want to alert other toxicologists about new or unexpected products that should be taken into account when the surreptitious use of substances in DFSA is suspected.

Home blood pressure in poorly controlled hypertension: relationship with ambulatory blood pressure and organ damage

OBJECTIVES

(1) To assess whether home blood pressure measurement is a reliable alternative to ambulatory blood pressure monitoring for the evaluation of treated patients with inadequate blood pressure control at the clinic; and (2) to evaluate the relationship between home blood pressure and several target-organ damage markers.

BASIC METHODS

A cross-sectional study was performed in 225 treated hypertensive patients with persistently high blood pressure values at the clinic (systolic blood pressure 140 mmHg and/or diastolic blood pressure 90 mmHg). All study participants underwent clinic blood pressure measurement, 24-h ambulatory blood pressure and home blood pressure monitoring. A subgroup of patients underwent the following procedures: carotid echography (n=74), microalbuminuria determination (n=88) and echocardiography (n=43). We defined out-of-clinic normotension as an average ambulatory or home blood pressure less than 135 mmHg (systolic) and 85 mmHg (diastolic).

MAIN RESULTS

The sensitivity, specificity and positive and negative predictive values of the home blood pressure method for predicting out-of-clinic normotension (with the ambulatory method used as reference), expressed as percentages, were 50, 87, 64 and 79%, respectively. Systolic home blood pressure correlated significantly with left ventricular mass (r=0.33, P<0.05) and microalbuminuria (r=0.24, P<0.05). Similar correlation coefficients were found for systolic ambulatory blood pressure (r=0.32, P<0.05 and r=0.24, P<0.05, respectively). Clinic blood pressure did not correlate with either left ventricular mass or microalbuminuria (r=0.19, P=0.09 and r=0.19, P=0.24, respectively). Diastolic home blood pressure, but not ambulatory blood pressure, correlated negatively with mean carotid intima-media thickness (r=-0.27, P<0.05).

CONCLUSION

Our results suggest that, in patients with poorly controlled hypertension at the clinic, home blood pressure represents a complementary test rather than an alternative to ambulatory blood pressure, and correlates with several target-organ damage markers.

Toxicokinetics of lambda-cyhalothrin in rats

The toxicokinetics of lambda-cyhalothrin after single 20 mg kg(-1) oral and 3 mg kg(-1) intravenous doses were studied in rats. Serial blood samples were obtained after oral and intravenous administration. Liver, brain, spinal cord, sciatic nerve, vas deferens, anococcygeus and myenteric plexus tissue samples were also collected. Plasma, liver, hypothalamus, cerebellum, medulla oblongata, frontal cortex, striatum, hippocampus, midbrain, spinal cord, vas deferens, anococcygeus, myenteric plexus and sciatic nerve concentrations of lambda-cyhalothrin were determined by HPLC. The plasma and tissue concentration-time data for lambda-cyhalothrin were found to fit a two-compartment open model. For lambda-cyhalothrin, the elimination half-life (T1/2beta) and the mean residence time from plasma were 7.55 and 8.55 h after i.v. and 10.27 and 14.43 h after oral administration. The total plasma clearance was not influenced by dose concentration or route and reached a value of 0.060l h(-1)kg(-1). After i.v. administration, the apparent volume of distribution and at steady state were 0.68 and 0.53l kg(-1), suggesting a diffusion of the pyrethroid into tissue. After oral administration, lambda-cyhalothrin was extensively but slowly absorbed (Tmax, 2.69 h). The oral bioavailability was found to be 67.37%. Significant differences in the kinetic parameters between nervous tissues and plasma was observed. The maximum concentrations in hypothalamus (Cmax, 24.12 microg g(-1)) and myenteric plexus (Cmax, 25.12 microg g(-1)) were about 1.5 times higher than in plasma (Cmax, 15.65 microg ml(-1)) and 1.3 times higher than in liver (Cmax, 18.42 microg ml(-1)). Nervous tissue accumulation of lambda-cyhalothrin was also reflected by the area under the concentration curve ratios of tissue/plasma (liver). The T1/2beta for lambda-cyhalothrin was significantly greater for the nerve tissues, including neuromuscular fibres, (range 12-26 and 15-34 h, after i.v. and oral doses) than for plasma (7.55 and 10.27 h, respectively).

Anesthesiologist Suicide with Atracurium

Atracurium is a nondepolarizing skeletal muscle relaxant used to facilitate endotracheal intubation and to induce skeletal muscle relaxation during surgery or mechanical ventilation. The drug undergoes a spontaneous non-enzymatic biotransformation, yielding laudanosine and an acrylate moiety. This report documents the case of a 45-year-old anesthesiologist who was found dead at the hospital where he worked. The victim was known to be depressed and undergoing treatment with venlafaxine. An empty syringe was found near the body. Toxicological analysis revealed the presence of laudanosine in the syringe, 0.6 mg/L of laudanosine in heart blood, 0.3 mg/L in urine, and 0.02 mg/L in vitreous humor. Meanwhile, concentrations of venlafaxine and O-desmethyl-venlafaxine, its active metabolite, were 0.7 and 1.1 mg/L in heart blood, 1.7 and 5.2 mg/L in urine, 0.5 and 0.7 mg/L in vitreous humor, and 400 and 20 mg in gastric content, respectively. All drugs and metabolites involved in the case were detected using gas chromatography with nitrogen-phosphorus detection (GC-NPD) and confirmed using GC-mass spectrometry in full scan mode after solid-phase extraction using Bond-Elut Certify columns. Additional high-performance liquid chromatography coupled to diode-array detection screening also obtained the same results. Quantitation of laudanosine and venlafaxine together with its metabolite was carried out using GC-NPD. No other drugs, including ethanol, were detected. Recoveries for laudanosine and venlafaxine were 89% and 86%, respectively, at 0.5 mg/L; intraday and interday precisions were 2% and 6%, and 3% and 7%, respectively; and limits of detection and quantitation were 6 and 20 ng/mL and 18 and 59 ng/mL, respectively. The linearity of the blood calibration curves was excellent for both drugs with r(2) values of > 0.999 (range 0.1-2.0 mg/L). Based on the autopsy findings, case history, and toxicology results, the forensic pathologists ruled that the cause of death was an overdose of atracurium, and the manner of death was suicide.

Determination of several psychiatric drugs in whole blood using capillary gas–liquid chromatography with nitrogen phosphorus detection: comparison of two solid phase extraction procedures

A simple and reliable gas chromatographic method with nitrogen-phosphorus detection without derivatization was developed for the detection of several psychiatric drugs in whole blood as part of systematic toxicological analyses (STA). Drugs included mirtazapine, chlorpromazine, methotrimeprazine (levomepromazine), clothiapine, olanzapine, clozapine, haloperidol, and thioridazine. All drugs were studied at concentrations of 100-2,000 microg/L, except haloperidol that was studied at concentrations of 400-8,000 microg/L. In order to select the best blood purification procedure and therefore increase the signal to noise ratio we have compared two solid-phase extraction (SPE) columns, Chem Elut and Bond Elut Certify, for their recovery, precision, sensitivity and matrix purification efficiency. Recoveries for these drugs using Chem Elut columns at 500 and 2,000 microg/L (2,000 and 8,000 microg/L for haloperidol) were in the range 21-65%, with intra-assay and inter-assay precisions of less than 17% and 19%, respectively. Limits of detection (LODs) and limits of quantitation (LOQs) for mirtazapine, chlorpromazine, methotrimeprazine, clothiapine, olanzapine, clozapine, and thioridazine ranged from 62 to 161 microg/L and from 205 to 531 microg/L, respectively. LOD and LOQ for haloperidol were 442 and 1,458 microg/L, respectively. Recoveries of these compounds using Bond Elut Certify columns at 500 and 2,000 microg/L (2,000 and 8,000 microg/L for haloperidol) were in the range 44-97%, with intra-assay and inter-assay precisions of less than 7% and 14%, respectively. LODs and LOQs for mirtazapine, chlorpromazine, methotrimeprazine, clothiapine, olanzapine, clozapine, and thioridazine ranged from 37 to 66 microg/L and from 122 to 218 microg/L, respectively. LOD and LOQ for haloperidol were 156 and 515 microg/L, respectively. Linearity was observed in the studied range for all compounds with r(2) values of >0.999. The use of the mixed-mode bonded-silica Bond Elut Certify columns showed advantages comparing with Chem Elut columns for the screening of these psychotropic agents such as higher recoveries, cleaner extracts, better sensitivity, better precision and less solvent consumption and subsequent disposal.

Investigation of Fatalities Due to Acute Gasoline Poisoning

This paper presents a simple, rapid, reliable, and validated method suited for forensic examination of gasoline in biological samples. The proposed methodology has been applied to the investigation of four fatal cases due to gasoline poisoning that occurred in Spain in 2003 and 2004. Case histories and pathological and toxicological findings are described in order to illustrate the danger of gasoline exposure under several circumstances. Gasoline's tissular distribution, its quantitative toxicological significance, and the possible mechanisms leading to death are also discussed. The toxicological screening and quantitation of gasoline was performed by means of gas chromatography (GC) with flame-ionization detection, and confirmation was performed using GC-mass spectrometry in total ion chromatogram mode. m,p-Xylene peak was selected to estimate gasoline in all biological samples. Gasoline analytical methodology was validated at five concentration levels from 1 to 100 mg/L. The method provided extraction recoveries between 77.6% and 98.3%. The limit of detection was 0.3 mg/L, and the limit of quantitation was 1.0 mg/L. The linearity of the blood calibration curves was excellent with r2 values of > 0.997. Intraday and interday precisions had a coefficient of variation < or = 5.4% in all cases. Cases 1 and 2 consist of the accidental inhalation of gasoline vapor inside a small enclosed space. Case 3 is a death by recreational gasoline inhalation in a male adolescent. Heart blood concentrations were 28.4, 18.0, and 38.3 mg/L, respectively; liver concentrations were 41.4, 52.9, and 124.2 mg/kg, respectively; and lung concentrations were 5.6, 8.4, and 39.3 mg/kg, respectively. Case 4 was an accidental death due to gasoline ingestion of a woman with senile dementia. Peripheral blood concentration was 122.4 mg/L, the highest in our experience. Because pathological findings were consistent with other reports of gasoline intoxication and constituents of gasoline were found in the body, cause of death was attributed to acute gasoline intoxication. As a rule, this kind of poisoning offers little difficulty in diagnosis because there is a history of exposure, and the odor usually clings to the clothes, skin, or gastric contents. However, anatomic autopsy findings will be nonspecific and therefore toxicological analysis is necessary. There is a paucity of recent references regarding analytical and toxicological data, and this article provides evidence about toxic concentrations and is a useful adjunct to the postmortem toxicological interpretation of fatalities if the decedent has been involved in gasoline use.

A three-dimensional finite element analysis of the combined behavior of ligaments and menisci in the healthy human knee joint

We present here a three-dimensional FE model of the healthy human knee that included the main structures of the joint: bones, all the relevant ligaments and patellar tendon, menisci and articular cartilages. Bones were considered to be rigid, articular cartilage and menisci linearly elastic, isotropic and homogeneous and ligaments hyperelastic and transversely isotropic. Initial strains on the ligaments and patellar tendon were also considered. This model was validated using experimental and numerical results obtained by other authors. Our main goal was to analyze the combined role of menisci and ligaments in load transmission and stability of the human knee. The results obtained reproduce the complex, nonuniform stress and strain fields that occur in the biological soft tissues involved and the kinematics of the human knee joint under a physiological external load.

A finite element simulation of the effect of graft stiffness and graft tensioning in ACL reconstruction

BACKGROUND

The anterior cruciate is the most frequent knee ligament to be totally disrupted. Surgical reconstruction of the anterior cruciate ligament is a common practice to treat the disability or chronical instability of knees due to anterior cruciate ligament insufficiency. Some of the factors that influence the success or failure of the anterior cruciate ligament reconstruction are the integrity of secondary restraints, the preoperative laxity of the knee, the status of the articular and meniscal cartilages, the selection of the graft material, the surgical technique, the graft tension and the postoperative rehabilitation.

METHODS

In this paper we present and discuss the results obtained with a three-dimensional finite element model of the human knee joint corresponding to different aspects of human anterior cruciate ligament reconstruction. In particular, this model was used to investigate the effect of graft stiffness and graft tensioning on the knee joint biomechanics. The initial graft tension was set to 0, 20, 40 or 60 N with the knee at 0 degrees , 30 degrees and 60 degrees of flexion. Three different stiffnesses corresponding to those of patellar tendon, gracilis and quadrupled semitendinosus grafts were analyzed.

FINDINGS

The resulting kinematics in each of these cases under an anterior load of 134 N was compared to that of the intact knee. The obtained results showed that, after reconstruction, the closest anterior tibial translation to that of the intact knee is obtained with a bone-patellar tendon-bone graft with a pretension of 60 N.

INTERPRETATION

However, this initial tension produces an important additional stress in the graft during the knee movement. This may cause problems in revascularization and remodelling during the postoperative healing process. A lower pretension of about 40 N should therefore be recommended in the present conditions.

Finite element analysis of the effect of meniscal tears and meniscectomies on human knee biomechanics

BACKGROUND

Many authors have suggested that the high levels of shear and tensile stresses that appear in the articular cartilage after meniscectomy are partly responsible for cartilage pathologies, such as osteoarthrosis.

METHODS

In this paper, we investigate the effect of meniscal tears and meniscectomies on the human knee joint. Solid models of the tibia, femur, menisci and cartilage were generated from MRI images. A three-dimensional finite element model was developed that included the femur, tibia, cartilage layers, menisci and ligaments. The femur and tibia were considered to be rigid, the articular cartilage and menisci to be linearly elastic, isotropic and homogeneous and the ligaments were modelled as hyperelastic. Three different situations were compared: a healthy tibio-femoral joint, a tibio-femoral joint with tears in one meniscus and a tibio-femoral joint after meniscectomy.

FINDINGS

The minimal principal stresses corresponding to a compressive load at 0 degrees flexion were obtained for the posterior zone of the medial meniscus and the corresponding region of the articular cartilage. Under an axial femoral compressive load, the maximal contact stress in the articular cartilage after meniscectomy was about twice that of a healthy joint.

INTERPRETATION

This fact could partially explain the cartilage damage and degeneration that have been observed after meniscectomy.

Effects of the type of dietary fat on acetylcholine-evoked amylase secretion and calcium mobilization in isolated rat pancreatic acinar cells

Olive oil is a major component of the Mediterranean diet, and its role in human health is being actively debated. This study aimed to clarify the mechanism of pancreatic adaptation to dietary fat. For this purpose, we examined whether dietary-induced modification of pancreatic membranes affects acinar cell function in response to the secretagogue acetylcholine (ACh). Weaning male Wistar rats were assigned to one of two experimental groups and fed for 8 weeks with a commercial chow (C) or a semisynthetic diet containing virgin olive oil as dietary fat (OO). The fatty acid composition of pancreatic plasma membranes was determined by gas-liquid chromatography. For assessment of secretory function, viable acini were incubated with ACh and amylase of supernatant was further assayed with a substrate reagent. Changes in cytosolic Ca(2+) concentration in response to ACh were measured by fura-2 AM fluorimetry. Compared to C rats, pancreatic cell membranes of OO rats had a higher level of monounsaturated fatty acids and a lower level of both saturated and polyunsaturated fatty acids, thus, reflecting the type of dietary fat given. Net amylase secretion in response to ACh was greatly enhanced after OO feeding, although this was not paralleled by enhancement of ACh-evoked Ca(2+) peak increases. In conclusion, chronic intake of diets that differ in the fat type influences not only the fatty acid composition of rat pancreatic membranes but also the responsiveness of acinar cells to ACh. This mechanism may be, at least in part, responsible for the adaptation of the exocrine pancreas to the type of fat available.

Investigation of a Fatality Due to Trazodone Poisoning: Case Report and Literature Review

Trazodone is an antidepressant agent used in Spain since 1975. There are few documented reports of fatalities solely attributed to trazodone and none in which the main metabolite is analyzed. A fatal case of self-poisoning following oral ingestion is reported along with a description of the validated analytical methods involved, a discussion of poisoning characteristics, and a review of reports describing trazodone overdose cases with analytical results. The deceased was an 86-year-old man with cancer, who suffered depression. He went to see his doctor in a primary health care unit and told him he had just taken an unknown amount of tablets of Deprax to commit suicide. The doctor induced emesis as a first emergency measure. His death occurred before arriving to the hospital, and he left a suicide note nearby. Systematic toxicological analysis of postmortem blood used routinely in our laboratory revealed the presence of trazodone 4.9 mg/L and m-chlorophenyl-piperazine (m-CPP) 0.6 mg/L, its active and major metabolite. In addition, metamizol 19.6 mg/L and 4-methyl-amino-antipyrine (4-MAA) 40.7 mg/L, its active metabolite, were also found in blood. All drugs and metabolites involved in the case were detected using gas chromatography-nitrogen-phosphorus detection (GC-NPD) and confirmed using gas chromatography-mass spectrometry (GC-MS) mode total ion chromatogram. An additional high-performance liquid chromatography-diode array detection (HPLC-DAD) screening also obtained the same results. Quantitation of trazodone together with its metabolite in blood was carried out using GC-NPD, while quantitation of metamizol was performed using HPLC-DAD. Limits of detection for trazodone and m-CPP were 33 and 11 microg/L, respectively, absolute recoveries were more than 86% and 75%, respectively, intra-assay precisions less than 4%, interassay precisions less than 5%, and linearity up to 2.0 mg/L. Limit of detection for metamizol was 1117 microg/L, absolute recovery more than 84%, intra-assay precision less than 8%, interassay precision less than 12%, and linearity up to 48 mg/L. Based on the autopsy findings, patient history, toxicology results, and previously reported trazodone intoxications, the forensic pathologists ruled that the cause of death was due to an overdose of trazodone, and the manner of death was listed as suicide.