Stable isotopic characterization of ammonium metavanadate (NH4VO3)

The diagnosis of fatal anaphylaxis can be difficult for clinical features may not always be evident in necropsy. Therefore post mortem determination of tryptase and other blood parameters can be helpful in verifying the diagnosis. We compared post mortem tryptase, histamine and diamine oxidase (DAO) serum levels of two patients who had died after a Hymenoptera sting and one patient who died of bronchospasm during anaesthesia with data obtained from 55 control subjects who had died from other causes than anaphylaxis. In the three anaphylactic cases, serum tryptase level was 880, 68 and 200 μg/l (normal range in living subjects: <11.4 μg/l), histamine was 37.5, 8.5 and 23.2 ng/ml (normal range: <0.3 ng/ml) and DAO was 1, 30 and 4 U/ml (normal range 10-30 U/ml), respectively. Values in the control group were as follows: tryptase 1-340 μg/l (mean 24.2 ± 58.2), histamine 5.0-22.0 ng/ml (mean 14.7 ± 3.9) and DAO 0-114 U/ml (mean 21.1 ± 27.8). 19/55 (34.5%) of the controls had elevated tryptase levels >11.4 μg/l, with four of them showing values >45 μg/ml. Significantly higher histamine levels were seen in blood samples taken more than 24h post mortem (p<0.05), whereas the timing of blood collection had no effect on tryptase and DAO levels. While moderately elevated tryptase levels are common in post mortem sera, values above 45 μg/l may support the diagnosis of fatal anaphylaxis. Strongly elevated histamine levels might give an additional clue on fatal anaphylaxis, whereas DAO does not seem to be helpful.     

Heart fatty acid binding protein as a marker for postmortem detection of early myocardial damage

Depletion of heart fatty acid binding protein (H-FABP) from cardiomyocytes with varying post-ischemia intervals was studied in acute myocardial infarction (AMI) model of rat, and 22 human autopsy cases were studied with streptavidin-peroxidase conjugated method (S-P). It was observed that as early as 15 min after ischemia, the depletion of H-FABP could be detected in model rats. With the ischemic time prolonged, the depletion of H-FABP was more and more evident. In all human cases with myocardial infarction, absent H-FABP staining could be found in infarcted area. And in some suspected early myocardial infarction cases, depletion of H-FABP staining could be demonstrated in areas that showed normal hematoxylin-eosin (HE) staining. The blood samples from model rats before ligation, at varying post-ischemia intervals and various postmortem time were measured for plasma concentration of H-FABP with enzyme-linked immuno-sorbent assay (ELISA) method. At 15 min after myocardial ischemia, the concentration of H-FABP was 4 times higher (546.0+/-85.3 microg/l) than that of the baseline level (103.7+/-94.1 microg/l). With the continuation of ischemic time, the concentration of H-FABP increased and peaked at 4 h (1953.5+/-405.3 microg/l), then decreased. The plasma concentration of H-FABP decreased slightly with postmortem time, but was still significant higher at any postmortem intervals than that of baseline level within 48 h after death. The results suggest that H-FABP staining can detect very early ischemic damages in human myocardium and the elevated plasma concentration of H-FABP in rat was an indicator of AMI, which was not affected by autolysis.     

The atlas of dialkylphosphates; assessment of cumulative human organophosphorus pesticides' exposure

Organophosphorus pesticides (OPs) are a group of chemicals with significant health interest, due to their wide spectrum of action and their excessive use both indoors (household) and outdoors (occupationally). The non-specific metabolites of OPs, dialkylphosphates (DAPs), are the most commonly used indicators for the assessment of cumulative OP exposure in humans. This review presents studies on human biomonitoring of OPs in the general population and in occupationally exposed humans. Furthermore, cases of OP intoxication determined by the measurement of DAP metabolites in various biological samples are included. In many studies, urine samples from both the general population and exposed populations have been analyzed mainly in Europe and America, while other matrices such as amniotic fluid, meconium, hair and blood have been less studied. A variety of analytical techniques were used for the determination of DAPs in these matrices. In studies measuring DAPs in urine samples, the detected concentrations ranged from 18 to 830ppb for the general population, while the corresponding values for exposed populations ranged from 29 to 1370ppb. Studies on amniotic fluid indicated DAP levels of 0.3-2.8ppb. Studies on meconium samples showed a concentration range of 0.5-16,000ppb. DAP levels in hair samples ranged from 40 to 165ppb for the general population and from 181.7 to 812.9ppb for the exposed population. Each matrix provides specific information on OP exposure, namely acute, long-term, chronic or prenatal. Meconium and hair can indicate cumulative exposure, while amniotic fluid is an indicator of fetal exposure to xenobiotics. Thus, various biological samples provide a more comprehensive view of OP exposure. In general, dimethylphosphate (DMP) and diethylphosphate (DEP) levels were higher in mainly urine samples, than other methyl and ethyl phosphates. In addition, results in the existing literature are sufficient to demonstrate the difference in levels of DAPs in general and occupationally exposed populations, mainly in urine and hair samples. However, more studies are needed to measure DAP levels in matrices such as amniotic fluid, meconium and hair to add to the literature and confirm existing data.     

Efficacy of cerebro-spinal fluid biochemistry in the diagnosis of brain insult.

Postmortem biochemical indices may provide a useful adjunct to morphological studies in the identification of antemortem brain insult. We studied 34 routine medico-legal cases categorising them into one of four diagnostic groups. There were 11 cases of head trauma, 7 of 'hypoxia' (3 hangings and 4 carbon monoxide or drug poisonings), 7 sudden cardiac deaths and 9 miscellaneous cases. Survival time and postmortem interval was known for each case. The degree of cranio-cerebral trauma was graded. Cerebro-spinal fluid (CSF) and vitreous humour were analysed for calcium, glucose, total proteins, aldolase, aspartate transaminase (AST), alanine transaminase (ALT), gamma glutamyltransferase (GGT), lactate dehydrogenase (LDH), creatine kinase (CK) and creatine kinase BB isoenzyme (CK-BB). CK-BB was also measured in superior vena cava serum. In CSF there was a significant correlation between the severity of cranio-cerebral trauma and levels of aldolase, CK-BB, AST, ALT and total proteins. CSF CK-BB, median units/l (range), for the groupings of head trauma, hypoxia, sudden cardiac death and miscellaneous were respectively 823 (2-3431); 96 (2-187); 4 (2-25); 5 (1-69). Corresponding serum CK-BB levels were 240 (28-322); 390 (26-411); 180 (20-482); 79 (18-530).     

Urine/blood ratios of ethanol in deaths attributed to acute alcohol poisoning and chronic alcoholism

The concentrations of ethanol were determined in femoral venous blood (BAC) and urine (UAC) and the UAC/BAC ratios were evaluated for a large case series of forensic autopsies in which the primary cause of death was either acute alcohol poisoning (N=628) or chronic alcoholism (N=647). In alcohol poisoning deaths both UAC and BAC were higher by about 2g/l compared with chronic alcoholism deaths. In acute alcohol poisoning deaths the minimum BAC was 0.74 g/l and the distribution of UAC/BAC ratios agreed well with the shape of a Gaussian curve with mean+/-standard deviation (S.D.) and median (2.5th and 97.5th centiles) of 1.18+/-0.182 and 1.18 (0.87 and 1.53), respectively. In alcoholism deaths, when the BAC was above 0.74 g/l (N=457) the mean+/-S.D. and median (2.5th and 97.5th centiles) UAC/BAC ratios were 1.30+/-0.29 and 1.26 (0.87 and 2.1), respectively. When the BAC was below 0.74 g/l (N=190), the mean and median UAC/BAC ratios were considerably higher, being 2.24 and 1.58, respectively. BAC and UAC were highly correlated in acute alcohol poisoning deaths (r=0.84, residual S.D.=0.47 g/l) and in chronic alcoholism deaths (r=0.95, residual S.D.=0.41 g/l). For both causes of death (N=1275), the correlation between BAC and UAC was r=0.95 and the residual S.D. was 0.46 g/l. The lower UAC/BAC ratio observed in acute alcohol poisoning deaths (mean and median 1.18:1) suggests that these individuals died before absorption and distribution of ethanol in all body fluids were complete. The higher UAC/BAC ratio in chronic alcoholism (median 1.30:1) is closer to the value expected for complete absorption and distribution of ethanol in all body fluids.     

Comparative evaluation of postmortem serum concentrations of neopterin and C-reactive protein

The cellular immune response is accompanied by the release of neopterin. The level of neopterin in serum is increased in patients suffering from viral infections, autoimmune diseases, systemic inflammation, allograft rejection and malignant diseases, while that of C-reactive protein (CRP) is known to rise during inflammatory diseases and traumas. To investigate postmortem neopterin and CRP concentrations with regard to the cause of death, we examined cardiac and peripheral blood samples in 474 autopsy cases without advanced decomposition (0-96 years of age, 343 males and 131 females), 2.8 h to 3 days (median, 18.0 h) after death. Survival time was 0.1 h to 5 months (median, 3.0 h) for traumatic death, and 0.1-1, 440 h (median, 2.5 h) for natural death. In autopsied subjects, neopterin concentrations were higher than the clinical reference, independent of the time after death, and depended on the survival time. In cases of acute and subacute death due to trauma, the neopterin level in right heart blood was mildly to moderately elevated (about 50-200 nmol/l) except for sharp instrument injury, whereas the CRP concentration usually remained low (<1 mg/dl). However, a moderate rise in the CRP level (around 1-10 mg/dl) was observed in fatal cases of hypothermia (cold exposure). Markedly elevated serum CRP and neopterin levels (>10 mg/dl and >500 nmol/l, respectively) were detected in cases of delayed death due to trauma involving systemic inflammatory response syndrome (SIRS) and of fatal bacterial infections. For sepsis, the serum CRP level was markedly elevated but the neopterin level was low in some cases. Fatal viral infections usually resulted in a marked elevation in the serum neopterin level (>500 nmol/l) with a mild to moderate rise in the CRP level. Combined analyses of neopterin and CRP may be useful to investigate viral infections and delayed traumatic death involving SIRS to support pathological findings.     

Variability of simulants used in recreating stab events

Formic acid (FA) concentration was measured in post-mortem blood and urine samples as methyl formate using a headspace in-tube extraction gas-chromatography-mass-spectrometry method. A total of 113 cases were analyzed, each including a blood and urine sample fortified with 1% sodium fluoride. The cases were divided into three groups: regular (n=59), putrefied (n=30), and methanol-positive (n=22) cases. There was no evidence of ante-mortem methanol consumption in the regular and putrefied cases. In regular cases, the mean (and median) FA concentrations were 0.04 g/l (0.04 g/l) and 0.06 g/l (0.04 g/l) in blood and urine, respectively. In putrefied cases, the mean (and median) FA concentrations were substantially higher, 0.24 g/l (0.22 g/l) and 0.25 g/l (0.15 g/l) in blood and urine, respectively. In three putrefied cases, FA concentration in blood exceeded 0.5 g/l, a level associated with fatal methanol poisoning. Ten putrefied cases were reanalyzed after 3-4 months storage, and no significant changes in FA concentrations were seen. These observations suggest that FA was formed by putrefaction during the post-mortem period, not during sample storage when sodium fluoride was added as a preservative. In methanol-positive cases, the mean (and median) FA concentrations were 0.80 g/l (0.88 g/l) and 3.4 g/l (3.3 g/l) in blood and urine, respectively, and the concentrations ranged from 0.19 to 1.0 g/l in blood and from 1.7 to 5.6 g/l in urine. The mean (and median) methanol concentrations in methanol-positive cases were 3.0 g/l (3.0 g/l) and 4.4 g/l (4.7 g/l) in blood and in urine, respectively. The highest methanol concentrations were 6.0 g/l and 8.7 g/l in blood and urine, respectively. No ethyl alcohol was found in the methanol-positive blood samples. Poor correlation was shown between blood and urine concentrations of FA. Poor correlations were also shown, in both blood and urine, between methanol and FA concentrations.     

Blood carbon monoxide and hydrogen cyanide concentrations in the fatalities of fire and non-fire associated civil aviation accidents, 1991-1998

To evaluate pathophysiological significance of post-mortem urinary myoglobin levels in determining the cause of death, we investigated 210 forensic autopsy cases, partially in comparison with serum levels. Post-mortem serum myoglobin levels were extraordinary high in most cases possibly due to post-mortem change. Urinary myoglobin levels did not correlate with the serum levels, showing possible post-mortem elevation in cases of a prolonged post-mortem period over 48h. A high (>1000 ng/ml), moderate (100-1000 ng/ml), slight (50-100 ng/ml) and not significant (<50 ng/ml) elevation of urinary myoglobin were observed in 26, 43, 31 and 110 cases, respectively. Half the highly elevated cases were those with a survival time over 24h. In cases of minor muscle injury such as head trauma, elevation of urinary myoglobin level was closely related to longer survival. In acute/subacute deaths with a post-mortem interval within 48h, a significant difference was observed in relation to the blood carboxyhemoglobin (COHb) levels of fire victims: myoglobinuria over 100 ng/ml was more frequently and markedly observed in cases with COHb below 60% than over 60%, suggesting muscle damage in fatal burns. Similar elevation was observed in heat stroke victims, and also in some cases of acute and subacute death from polytrauma, asphyxiation, drowning, electricity and spontaneous cerebral bleeding, but not in myocardial infarction. Thus, it was suggested that high post-mortem urinary myoglobin levels in acute and subacute death cases may be a possible indicator of antemortem massive skeletal muscle damage as well as exertional muscle hyperactivity or convulsive disorders associated with hypoxia.     

Acute organophosphorus insecticide poisoning in Sri Lanka

Records of 92 cases of acute organophosphorus (OP) insecticide poisoning were analysed. Of the patients 91% were under 30 years of age and 86% were males. The common agents were Dimethoate, Methamidophos, Malathion, Monocrotophos and Fenthion. Poisoning was due to ingestion with suicidal intent in the majority. In addition to the acute cholinergic features, the other important manifestations were delayed onset respiratory paralysis and delayed polyneuropathy. The overall mortality was 18%.     

Phosphoenolpyruvate carboxykinase activity in human liver

The activity of phosphoenolpyruvate carboxykinase (EC 4.1.1.32) (PEPCK), a rate-limiting gluconeogenic enzyme, was found decreased by others in genetically determined disorders and in Sudden Infant Death Syndrome (SIDS). To understand these findings, we made a systematic study of normal human hepatic PEPCK activities in specimens obtained under various conditions from patients not suspected of having SIDS. PEPCK was assayed by the method of Ballard and Hanson [J. Biol. Chem., 244 (1969) 5625] and activity reported as units (1 mumol/min) per gram protein. Intra-assay precision was 4.1% (n = 1094); inter-assay precision using the same homogenate was 10.4% (n = 51); and inter-assay precision using different homogenates of the same tissue specimen was 16.3% (n = 17). The assay was linear with time and enzyme concentration for at least 60 min up to 1.3 mU/assay and for at least 5 min up to 20 mU/assay. Biopsy specimens had significantly (P = 0.015) higher PEPCK activity, 12.60 +/- 3.01 U/g (range 3.5-10.4, n = 9) compared to specimens obtained at autopsy, 3.20 +/- 0.45 U/g (range 0-8.6, n = 33). Specific activity was not significantly correlated with the patient's age, fresh vs. frozen tissue, postmortem intervals up to 68 h, or length of storage at -70 degrees C up to 21 years. One patient had activity at autopsy (tissue obtained less than 2 h postmortem) 26% less than was observed in his biopsy specimen. Autopsy samples separated by differential centrifugation into mitochondrial and cytosolic fractions and checked with marker enzymes ornithine transcarbamylase (mitochondrial) and arginase (cytosolic) had considerable cross-contamination between the two fractions in fresh and frozen specimens.     

Mast cell tryptase and hemolysis after trauma

BACKGROUND: We have previously found increased mast cell tryptase in accidental deaths due to trauma, indicating that mast cell degranulation had occurred. The present study was designed to confirm the previous observation and to determine if tryptase release after trauma is acute or delayed. Furthermore, the importance of hemolysis and direct trauma to the mast cells was investigated. MATERIALS AND METHODS: Mast cell tryptase was measured in post-mortem blood from the femoral vein in 27 cases of death from trauma and in 27 control cases by means of a commercially available immunoassay. The trauma cases were further classified into groups with single versus multiple trauma, and groups with short survival time (i.e. death at the scene of the accident) versus longer survival time (death in hospital). In five multi-trauma deaths, blood was sampled locally from the sites of crush injury. RESULTS: The mean value of tryptase in femoral vein blood was 35.6+/-34.6 microg/l in the entire trauma group and 14.7+/-6.5 microg/l in the controls (P<0.005). In bloody liquid sampled from crush injuries, tryptase was substantially elevated in all cases, with a mean of 227+/-146 microg/l. In cases with short survival time, tryptase was significantly higher than in those who died after several hours or days in hospital (P<0.001). No statistically significant difference was seen between multi- and single-trauma cases. A correlation between hemolysis in the samples and elevated tryptase was found only in the trauma cases (P<0.05), but experimentally induced hemolysis in vitro was not found to influence the measurements. CONCLUSION: Mast cell tryptase becomes elevated in trauma deaths and this seems to be ascribable either to direct mechanical injury to tissue mast cells and/or to cell lysis. In patients initially surviving severe injuries, the effects of massive release of histamine and other mast cell mediators might be of importance for treatment strategies and prognosis.     

Poisoning from oral ingestion of carbofuran (Furadan 4F), a cholinesterase-inhibiting carbamate insecticide, and its effects on cholinesterase activity in various biological fluids.

A case is presented of a fatal ingestion of Furadan (carbofuran), a cholinesterase-inhibiting carbamate insecticide. A 26-year-old white male was found dead with a partially filled 1-gal (3.8-L) container of Furadan 4F insecticide-nematocide (44.9% carbofuran). The individual had ingested approximately 345 mL of the mixture. Analysis of cholinesterase activity in various biological fluids was performed spectrophotometrically using propionylthiocholine and 5,5'-dithiobis-2-nitrobenzoic acid [Sigma Diagnostics, cholinesterase procedure No. 422 (PTC)] which was measured at 405 nm and 30 degrees C in a Gilford Stasar III Spectrophotometer. The cholinesterase activities were as follows: plasma, 245 units (U)/L (93% inhibition/7% normal activity); serum, 208 U/L (95.3% inhibition/4.7% normal activity); whole blood, 297 U/L (92.8% inhibition/7.2% normal activity); erythrocytes, 58 U/L (99% inhibition/1% normal activity); vitreous humor, 7 U/L; and bile, 148 U/L. Carbofuran was detected in the blood and gastric contents by thin-layer chromatography. No alcohol or other drugs were detected in the blood, urine, or gastric contents. Ingestion of the carbofuran produced acute visceral congestion and pulmonary edema. Death was caused by anoxia due to respiratory paralysis produced by cholinesterase inhibition from Furadan (carbofuran) ingestion.     

Comparison of ethanol concentrations in venous blood and end-expired breath during a controlled drinking study

Concentration-time profiles of ethanol were determined for venous whole blood and end-expired breath during a controlled drinking experiment in which healthy men (n=9) and women (n=9) drank 0.40-0.65 g ethanol per kg body weight in 20-30 min. Specimens of blood and breath were obtained for analysis of ethanol starting at 50-60 min post-dosing and then every 30-60 min for 3-6 h. This protocol furnished 130 blood-breath pairs for statistical evaluation. Blood-ethanol concentration (BAC, mg/g) was determined by headspace gas chromatography and breath-ethanol concentration (BrAC, mg/2l) was determined with a quantitative infrared analyzer (Intoxilyzer 5000S), which is the instrument currently used in Sweden for legal purposes. In 18 instances the Intoxilyzer 5000S gave readings of 0.00 mg/2l whereas the actual BAC was 0.08 mg/g on average (range 0.04-0.15 mg/g). The remaining 112 blood- and breath-alcohol measurements were highly correlated (r=0.97) and the regression relationship was BAC=0.10+0.91BrAC and the residual standard deviation (S.D.) was 0.042 mg/g (8.4%). The slope (0.91+/-0.0217) differed significantly from unity being 9% low and the intercept (0.10+/-0.0101) deviated from zero (t=10.2, P<0.001), indicating the presence of both proportional and constant bias, respectively. The mean bias (BAC - BrAC) was 0.068 mg/g and the 95% limits of agreement were -0.021 and 0.156 mg/g. The average BAC/BrAC ratio was 2448+/-540 (+/-S.D.) with a median of 2351 and 2.5th and 97.5th percentiles of 1836 and 4082. We found no significant gender-related differences in BAC/BrAC ratios, being 2553+/-576 for men and 2417+/-494 for women (t=1.34, P>0.05). The mean rate of ethanol disappearance from blood was 0.157+/-0.021 mg/(g per hour), which was very close to the elimination rate from breath of 0.161+/-0.021 mg/(2l per hour) (P>0.05). Breath-test results obtained with Intoxilyzer 5000S (mg/2l) were generally less than the coexisting concentrations of ethanol in venous blood (mg/g), which gives an advantage to the suspect who provides breath compared with blood in cases close to a threshold alcohol limit.     

Breaking the cycle demonstration project: using a quasi-experimental analysis to test the “worst of both worlds” hypothesis and risk principle

Objectives

The purpose of this study was to test the “worst of both worlds” hypothesis and the risk principle in a sample of drug-involved offenders enrolled in the Breaking the Cycle (BTC) demonstration project, an intensive drug intervention implemented in Birmingham, Alabama, Jacksonville, Florida, and Tacoma, Washington.

Methods

A group of 1081 drug-involved offenders enrolled in BTC were compared to 934 drug-involved offenders (pre-BTC) who processed through the regular court system of each city 1 year prior to implementation of BTC. Participants from both groups were divided into risk levels based on scores from the Addiction Severity Index (ASI) Drug (D) and Legal (L) scales. Individuals who scored at or above the mean on both the ASI-D and ASI-L were identified as high risk, individuals who scored at or above the mean on either the ASI-D or ASI-L but not both were identified as moderate risk, and individuals who scored below the mean on both the ASI-D and ASI-L were identified as low risk.

Results

Consistent with the risk principle, high-risk BTC participants displayed significant improvements in subsequent drug problem days, criminal offending, and days spent in jail relative to high-risk pre-BTC participants. There was no apparent benefit of BTC enrollment for moderate- and low-risk participants.

Conclusions

These results indicate that drug–crime comorbidity can be used to assess risk and that individuals identified as high risk are more likely to benefit from higher-intensity forms of intervention than moderate- or low-risk individuals.

     

Disposition of quetiapine in biological specimens from postmortem cases

Quetiapine is a new atypical antipsychotic that was approved in 1997 by the U.S. Food and Drug Administration for the treatment of schizophrenia. It possesses a high affinity for 5-HT2 receptors and a low affinity for D1 and D2 dopamine receptors. Because quetiapine has only been released recently to the U.S. market, little information exists regarding therapeutic, toxic, and lethal concentrations. This study reports the detection of quetiapine in 13 postmortem cases. Following a basic liquid-liquid extraction, quetiapine was identified and quantitated by capillary gas chromatography with nitrogen phosphorus detection. Confirmation was accomplished by full scan electron impact gas chromatography/mass spectrometry. Heart blood quetiapine concentrations ranged from 0.07 to 18.37 mg/L (N = 12, mean +/- SD = 3.42 +/- 5.67, median 0.62) and femoral blood concentrations ranged from 0.06 to 19.25 mg/L (N = 10. mean +/- SD = 3.89 +/- 6.12, median 0.81). The average heart blood/femoral blood ratio was 1.31 (range 0.55 to 2.57, N = 10). Urine, bile, and gastric contents were assayed in all cases in which they were submitted. In three cases, the cause of death was determined to be quetiapine toxicity. In these cases heart blood concentrations ranged from 0.72 to 18.37 mg/L (N = 3). These data may provide a basis for establishing levels associated with quetiapine toxicity as well as therapeutic concentrations in postmortem specimens.     

The National Ballistics Imaging Comparison (NBIC) project

In response to the guidelines issued by the American Society of Crime Laboratory Directors/Laboratory Accreditation Board (ASCLD/LAB-International) to establish traceability and quality assurance in U.S. crime laboratories, a NIST/ATF joint project entitled National Ballistics Imaging Comparison (NBIC) was initialized in 2008. The NBIC project aims to establish a National Traceability and Quality System for ballistics identifications in crime laboratories within the National Integrated Ballistics Information Network (NIBIN) of the U.S. NIST Standard Reference Material (SRM) 2460 bullets and 2461 cartridge cases are used as reference standards. 19 ballistics examiners from 13 U.S. crime laboratories participated in this project. They each performed 24 periodic image acquisitions and correlations of the SRM bullets and cartridge cases over the course of a year, but one examiner only participated in Phase 1 tests of SRM cartridge case. The correlation scores were collected by NIST for statistical analyses, from which control charts and control limits were developed for the proposed Quality System and for promoting future assessments and accreditations for firearm evidence in U.S. forensic laboratories in accordance with the ISO 17025 Standard.     

Melatonin concentrations in the sudden infant death syndrome

To examine a possible relationship between pineal function and the sudden infant death syndrome (SIDS), samples of whole blood, ventricular cerebrospinal fluid (CSF) and/or vitreous humor (VH) were obtained at autopsy from 68 infants (45 male, 23 female) whose deaths were attributed to either SIDS (n = 32, 0.5-5.0 months of age; mean +/- S.E.M., 2.6 +/- 0.2 months) or other causes (non-SIDS, n = 36, 0.3-8.0 months of age 4.3 +/- 0.3 months). The melatonin concentrations were measured by radioimmunoassay. A significant correlation was observed for melatonin levels in different body fluids from the same individual. After adjusting for age differences, CSF melatonin levels were significantly lower among the SIDS infants (91 +/- 29 pmol/l; n = 32) than among those dying of other causes (180 +/- 27; n = 35, P less than 0.05). A similar, but non-significant trend was also noted in blood (97 +/- 23, n = 30 vs. 144 +/- 22 pmol/l, n = 33) and vitreous humor (68 +/- 21, n = 10 vs. 81 +/- 17 pmol/l, n = 15). These differences do not appear to be explainable in terms of the interval between death and autopsy, gender, premortem infection or therapeutic measures instituted prior to death. Diminished melatonin production may be characteristic of SIDS and could represent an impairment in the maturation of physiologic circadian organization.     

Incidence of xenobiotics among drivers killed in single-vehicle crashes.

The authors have performed a study of single-vehicle crashes (SVCs) in order to verify a correlation between the loss of vehicle control and the presence of drugs in the body. Overall, 129 cases were recorded and occurred in the catchment area of the Institute of Legal Medicine in Milan between 1986 to 1996. Among the 129 cases under study, respectively 121 men and eight women, 101 were car-drivers and 28 motor-cyclists. The median age was equal to 29 years, while the average age to 32.0 years (range 15-65 years). Fifty eight cases (45.0%) were "positive" for the presence of ethanol > or = 0.8 g/l or other drugs. The sample of "positive cases" was studied according to sex, age, day, hour and type of vehicle. Considering the cases with presence of ethanol, although under the legal limit (20 cases), the total amount of cases (78) becomes even more consistent. The amount of ethanol was found to be respectively 0.34 g/l in daily drivers and 0.87 g/l in nightly drivers (p < 0.01). Our considerations confirm the importance of toxicological analyses in the forensic investigation of traffic deaths being the sample under study recorded following criteria which minimised other possible factors effecting road accidents.     

A study on the concentrations of 11-nor-Δ(9)-tetrahydrocannabinol-9-carboxylic acid (THCCOOH) in hair root and whole hair

In this study, we investigated the patterns of cannabis users (n=412) according to their sex, age, and the results of urinalysis and hair analysis, and classified the concentrations of THCCOOH in hair into three categories to examine the levels of cannabis use. We also compared the concentrations of THCCOOH in hair root, hair without the hair root and whole hair and examined the relationship among them according to the results of urinalysis. The hair samples were washed, digested with 1ml of 1M NaOH at 85°C for 30min and extracted with 2ml of n-hexane:ethyl acetate (9:1) two times after adding 1ml of 0.1N sodium acetate buffer (pH 4.5) and 200μl of acetic acid. The final mixture was derivatized with 50μl of PFPA and 25μl of PFPOH for 30min at 70°C. The solution was evaporated, and the residue was reconstituted in 40μl of ethyl acetate and transferred to an autosampler vial. One microlitre was injected into the GC/MS/MS-NCI system. The concentrations of THCCOOH ranged from 0.06 to 33.44pg/mg (mean 2.96; median 1.32) in hair from cannabis users who had positive urine results and ranged from 0.05 to 7.24pg/mg (mean 1.35; median 0.37) in hair from cannabis users who had negative urine results. The average concentration of THCCOOH in hair from cannabis users who had positive urine results was higher than that from cannabis users who had negative urine results. Male cannabis users in their forties were predominant. We classified the concentrations of THCCOOH in hair into three groups (low, medium and high), and could use the grouping of THCCOOH in hair as a guide for determining the level of use. The low, medium and high concentration ranges for THCCOOH in hair were 0.05-0.24, 0.25-2.60 and 2.63-33.44pg/mg, respectively. We also investigated 28 hair samples with the root. The highest concentrations of THCCOOH were seen in the hair root from 18 out of the 28 hair samples. The average concentrations of THCCOOH in hair root, hair without hair root and whole hair from cannabis users who had positive urine results were higher than those who had negative urine results.     

Influence of blood loss on the pharmacokinetics of citalopram

Extended blood loss results in several compensatory physiological mechanisms, including transfer of extravascular fluid into the blood circulation. If drugs are present in the body, this fluid exchange may imply that blood drug concentrations found in a trauma victim may differ from the concentrations present at the time of the trauma. To address this issue, an animal model was used to investigate the influence of blood loss on pre-existing levels of the antidepressant drug citalopram and its demethylated metabolites. Rats were administered citalopram either acutely (40 mg/kg, orally) or chronically (20 mg/kg daily, subcutaneously) for 6 days using osmotic pumps. In the experimental rats, blood loss was accomplished by withdrawing 0.8 mL blood at 10 min intervals during 70 min. In the control rats, blood was withdrawn at 0 and 70 min only. Blood, brain and lung drug concentrations were analyzed with an enantioselective HPLC method. In the chronically treated rats, the ratios between final and initial citalopram concentrations were 1.08 +/- 0.15 and 1.01 +/- 0.09 in the experimental rats and controls, respectively, indicating no major effect of blood loss. In contrast, acute oral administration resulted in increased ratios in the exsanguinated rats as compared to controls (1.84 +/- 0.50 versus 0.73 +/- 0.07; p = 0.0495). In conclusion, the observation of increased blood drug levels in the acute oral rats indicates that absorption of fluid from the gastrointestinal tract may be important in the intravascular refill. Further, in the interpretation of post-mortem blood levels of drugs, these physiological mechanisms should be taken into account.