Segmental hair analysis can demonstrate external contamination in postmortem cases

Excluding laboratory mistakes, a false positive hair result can be observed in case of contamination from environmental pollution (external contamination) or after drug incorporation into the hair from the individual body fluids, such as sweat or putrefactive fluid (post mortem artifact). From our 20 years experience of hair testing, it appears that artifact(s) cannot be excluded in some post mortem cases, despite a decontamination procedure. As a consequence, interpretation of the results is a challenge that deserves particular attention. Our strategy will be reviewed in this paper, based on six cases. In all cases, a decontamination procedure with two washes of 5 ml of dichloromethane for 5 min was performed and the last dichloromethane wash was negative for each target drug. From the histories, there was no suspicion of chronic drug use. In all six cases, the concentrations detected were similar along the hair shaft, irrespective of the tested segment. We have considered this as indicative of external contamination and suggested to the forces or the judges that it is not possible to indicate exposure before death. In contrast to smoke, it seems that contamination due to aqueous matrices (sweat, putrefactive fluid, blood) is much more difficult to remove. To explain potential incorporation of 7-aminoflunitrazepam via putrefactive material, the author incubated negative hair strands in blood spiked at 100 ng/ml and stored at +4°C, room temperature and +40 °C for 7, 14 and 28 days. After routine decontamination, 7-aminoflunitrazepam tested positive in hair, irrespective of the incubation temperature, as early as after 7 days (233-401 pg/mg). In all periods, maximum concentrations were observed after incubation at room temperature. The highest concentration (742 pg/mg) was observed after 28 days incubation at room temperature. It is concluded that a standard decontamination procedure is not able to completely remove external contamination in case of post mortem specimens. Homogenous segmental analyses can be probably indicative of external contamination and therefore a single hair result should not be used to discriminate long-term exposure to a drug. Nor should the presence of a metabolite be considered as a discrimination tool, as it can also be present in putrefactive material.     

Chloroquine distribution in postmortem cases

Chloroquine concentrations in blood and tissues were examined in overdose and non-overdose cases to determine appropriate ranges for interpretation. Twenty-nine literature overdose cases and 8 non-overdose literature cases were compared with this laboratory's findings. The results indicate significant postmortem redistribution of chloroquine. Combining this laboratory's results and the literature results indicates that using a liver concentration of 150 mg/kg as a cutoff between overdose and non-overdose concentrations properly identified 30 of the 34 published cases containing liver chloroquine and 19 of the 20 presented cases.     

Fluvoxamine distribution in postmortem cases

Four postmortem cases are reported in which the selective serotonin re-uptake inhibitor fluvoxamine was identified. Fluvoxamine was detectable using a standard alkaline drug screen, chromatographed well using a HP-1 column, and did not require derivitization for quantitation. Two of the cases reported were drug intoxications; fluvoxamine was only an incidental finding in the other 2 cases. Central and peripheral blood values are reported, as well as antemortem blood, bile, vitreous fluid, and urine values. No solid organs were obtained in any of the cases. Quantitations were performed using both an analytical standard and a fluvoxamine tablet for the preparation of calibrators. A comparison of quantitative values was made to evaluate the feasibility of using a tablet as the drug source for the preparation of calibrators when a pure reference material is unavailable. Postmortem peripheral blood concentrations ranged from approximately 0.5 mg/L in a case of suicidal shooting to approximately 6 mg/L in a case of drug overdose. Evidence of postmortem redistribution was noted in the only case for which both central and peripheral blood were obtained. Quantitations using an extracted drug tablet for the preparation of calibrators correlated well with quantitations using a pure reference material.     

Zolpidem distribution in postmortem cases

Zolpidem is the prototype of a class of sedative hypnotic drugs that are derivatives of imidazopyridine and is sold in the United States under the trade name Ambien. Over a four-year period, zolpidem was identified in eight cases investigated by the Office of the Chief Medical Examiner, State of Maryland. Zolpidem was identified by gas chromatography-nitrogen-phosphorus detection (GC-NPD) following an alkaline extraction and was confirmed by full-scan electron impact gas chromatography/mass spectrometry. Zolpidem was quantitated by GC-NPD in all specimens received. Five of the cases presented were deaths due to drug intoxication. In three of these cases, zolpidem was an incidental finding because the drug fatalities resulted from other drugs. In the other two cases of drug intoxication, zolpidem was present in elevated concentrations and was a contributing, but not exclusive cause of the drug intoxication. The remaining three cases were deaths that were not caused by drugs. The blood zolpidem concentrations in these cases were therapeutic (0.28, 0.12 and 0.19 mg/L, respectively). In six of the eight cases where both blood and urine were analyzed, the blood concentration was higher than the urine concentration. The distribution of zolpidem into the liver and kidney failed to identify any sequestration of the drug into either specimen.     

Analysis of 3130 cases of medicolegal postmortem

3130 cases of medicolegal postmortem in Shantou City between January 1977 and December 1996 were analyzed statistically. The results revealed that the ratio of male to female was 2.3 and most dead were young and middle age. The number of postmortem has increased in resent years. Of 3130 cases, 2829 (92.3%) were caused by mechanical injury, mechanical asphyxia, sudden death and poisoning. As to manners of the death, 1226 were related to accidents (39.2%), 776 homicide(29.8%), 658 suicide (21.0%). These results were compared with other studies reported in domestic and international literature.     

3130例法医尸检资料分析

对汕头市1977年1月至1996年12月20年间3130例法医尸检资料进行统计分析，探讨其性别、年龄、季节、死因和案情性质构成，并与国内外文献比较。结果表明男性为女性的2．3倍；青壮年居多；尸检数逐年增加；损伤、窒息、粹死、中毒占2829例（92．3％），意外1226例（39．2％），他杀776例（29．8％），自杀658例（21．0％）。与广州、湖北部分地区资料相似，与日本东京、美国佛罗里达资料存在明显差异。     

Evaluation of postmortem redistribution phenomena for commonly encountered drugs

We described the findings of a study into the post-mortem redistribution (PMR) of 76 drugs found in 129 drug-related cases between 2006 and 2009. Seventy six drugs (psychotropic drugs (n=14), antidepressants (n=9), sedatives (n=6) and so on) were simultaneously quantified in cardiac and peripheral blood by gas chromatography-mass spectrometry (GC/MS) or liquid chromatography-tandem mass spectrometry (LC/MS/MS). The absence, possibility or presence of PMR of drugs was determined according to the ratios of cardiac to femoral blood concentrations (C/P ratios). Proxyphylline (C/P ratio: 0.85) showed no PMR; carbamazepine was not subject to PMR; a potential for PMR of lorazepam and mirtrazapine cannot be excluded; chlordiazepoxide is subject to PMR; acetaminophen and alprazolam exhibit minimal PMR; amitriptyline and benztropine exhibit PMR. Codeine (C/P ratio: 4.9), zolpidem (C/P ratio: 3.74), chlorpromazine (C/P ratio: 2.97), fluoxetine (C/P ratio: 2.83) and propranolol (C/P ratio: 2.72) had the largest C/P ratios. Postmortem drug concentrations showed variations depending on sampling sites and characteristics of the drugs. It is continuously necessary to analyze commonly used or abused drugs in simultaneously collected cardiac and peripheral blood to establish significant reference values for PMR. These findings can be used to reach a conclusion about the cause and manner of death.     

Disposition of citalopram in biological specimens from postmortem cases

Citalopram is a bicyclic phthalate compound approved in 1998 by the U.S. Food and Drug Administration for the treatment of depression. It is a highly selective serotonin reuptake inhibitor that appears to have little effect on noradrenaline or dopamine reuptake. Since this drug has only recently been released on the U.S. market, information regarding therapeutic, toxic, and lethal concentrations is sparse. This study reports the detection of citalopram in 22 postmortem cases. Citalopram was identified and quantitated by capillary column gas chromatography with nitrogen phosphorus detection after basic liquid-liquid extraction. Confirmation was achieved by full scan electron impact gas chromatography/mass spectrometry. In the 22 cases studied, heart blood citalopram concentrations ranged from 0.09 to 1.64 mg/L (n = 22, mean +/- SD = 0.51+/-0.43, median = 0.34); femoral blood concentrations ranged from 0.09 to 0.76 mg/L (n = 14, mean +/- SD = 0.34+/-0.23, median = 0.28); and urine concentrations ranged from 0.05 to 276.00 mg/L (n = 13). Liver was analyzed in three cases with citalopram concentrations ranging from 2.22 to 8.08 mg/kg. The average heart blood/femoral blood ratio was 1.26 (range 0.75 to 1.98, n = 14). In each case, the cause of death was not considered to be related to citalopram toxicity. These data may therefore provide a basis for establishing post mortem citalopram concentrations following therapeutic doses.     

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.     

Stability of drugs in stored postmortem femoral blood and vitreous humor

The stability of 46 drugs in postmortem femoral blood stored for one year at -20 degrees C was investigated. The drugs included benzodiazepines, antidepressants, analgetics and hypnotics. For seven drugs we found a significant change in the concentration between the first and second analysis. Five substances; ethanol, desmethylmianserin, 7-amino-nitrazepam, THC and zopiclone showed a decrease in the concentration whereas the concentrations of two substances; ketobemidone and thioridazine increased. However, the changes observed were not of such an order that it would affect the interpretation in normal forensic casework. We also investigated the possible influence of potassium fluoride on the concentrations of the 46 drugs in vitreous humor after storage for one year. For two substances, ethanol and zopiclone, there were significantly lower concentrations in the samples without potassium fluoride. Furthermore, we also studied the correlation between the concentrations in femoral blood and vitreous humor. For 23 substances there was a significant difference between the concentrations in the vitreous humor and femoral blood. Significant correlations between the concentrations in these two specimens were found for 23 substances, indicating that vitreous humor can be an alternative specimen when blood samples are not available, provided that such correlation exists for the particular substance. Statistical analysis also revealed a correlation between the degree of protein binding of the different drugs and percentage of vitreous/femoral blood concentrations.     

Bile analysis in heroin overdose

Abstract:  Following its metabolism in the liver, morphine and its metabolites can be directly eliminated in bile. Then, they undergo the enterohepatic cycle (EHC) and mostly reappear in the circulation. We report a case showing the presence of morphine in bile (21.3 μg/mL) and hair (4.8 ng/mg) but not in blood, urine or the liver of an addict who survived in hospital for about 144 h (6 days). These data would indicate that the EHC does not play any role about 144 h after the last injection, and directly confirms that gall bladder is a storage depot for morphine. They constitute the first report of a demonstration of the effect of the EHC on morphine bioavailability in an addict, and could be considered as indication, without supporting circumstantial evidence, that the morphine level in bile is related to chronic opiate use.     

Value of hair analysis in postmortem toxicology

It is generally accepted that chemical testing of biological fluids is the most objective means of diagnosis of drug use. The presence of a drug analyte in a biological specimen can be used to document exposure. The standard in postmortem drug testing is a general unknown screening, followed by the gas chromatographic/mass spectrometric confirmation conducted on a whole blood sample. In recent years, remarkable advances in sensitive analytical techniques have enabled the analysis of drugs in unconventional biological specimens such as hair. The advantages of this sample over traditional media, like urine and blood, are obvious: collection is almost non-invasive, relatively easy to perform, and in forensic situations it may be achieved under close supervision of law enforcement officers to prevent adulteration or substitution. Moreover, the window of drug detection is dramatically extended to weeks, months or even years. The aim of this review is to document the current status of hair analysis in postmortem toxicology.     

尸检样本乙醇分析结果的解释策略

由于死后各种复杂的人为现象的存在，使得建立死后血液酒精含量（BAC）和死亡时醉酒状态之间的关系十分困难。在日常检案中必须考虑细菌污染、发酵是否引起死后乙醇再合成．死亡时胃中未被吸收的乙醇是否向周围组织以及血中扩散等问题。本文总结了关于死后乙醇分析及结果解释相关问题的研究文献，旨在为从事法医毒物学乙醇分析的同行在调查此类案件时提供良好的开端。     

尸检样本乙醇分析结果的解释策略

由于死后各种复杂的人为现象的存在,使得建立死后血液酒精含量(BAC)和死亡时醉酒状态之间的关系十分困难。在日常检案中必须考虑细菌污染、发酵是否引起死后乙醇再合成,死亡时胃中未被吸收的乙醇是否向周围组织以及血中扩散等问题。本文总结了关于死后乙醇分析及结果解释相关问题的研究文献,旨在为从事法医毒物学乙醇分析的同行在调查此类案件时提供良好的开端。     

Screening postmortem blood and tissues for nine classes [correction of cases] of drugs of abuse using automated microplate immunoassay

A commercially available enzyme-linked immunosorbant assay (ELISA) was evaluated as a screening procedure for the detection of nine classes of abused drugs in postmortem blood and tissue specimens. Specifically, postmortem blood, fluid and/or tissue homogenates were screened for amphetamine (AMP), methamphetamine (MET), barbiturates (BARB), benzodiazepines (BZD), cannabinoids (CNB), cocaine (benzoylecgonine; BE), morphine-specific (MOR), opiates (class; OPI), phencyclidine (PCP) and lysergic acid diethylamide (LSD) by ELISA and by coated tube radioimmunoassay (CTR) (BARB, BE, OPI, PCP, LSD) or double-antibody radioimmunoassay (DAR) (AMP/METH, BZD, CNB). Specimens that screened 'positive' by any method were confirmed and quantitated by gas chromatography/mass spectrometry (GC/MS). The only assay that appeared to perform less optimally than RIA was the MOR assay (five false negatives). However, this assay is very specific for free morphine while the GC/MS confirmation method provided a total morphine value. The OPI assay was more sensitive, producing fewer false negatives, and is recommended for broad class opiate screening. EIA is an adequate alternative to RIA for screening postmortem specimens, including blood and tissue, for nine major classes of drugs.     

The interpretation of cocaine and benzoylecgonine concentrations in postmortem cases.

This study examined cocaine and benzoylecgonine concentrations in 100 consecutive deaths where either compound was identified in blood or urine specimens to determine whether any relationship between these concentrations and cause of death can be found. Forty-seven of the 100 cases were deaths attributed to cocaine, narcotic or combined cocaine and narcotic intoxication. There were 13 cases of cocaine intoxication where no psychoactive substance other than ethanol was detected. The mean cocaine concentration in these deaths was 908 ng/ml; three cases had cocaine concentrations greater than 2000 ng/ml, while the other ten cases had cocaine concentrations less than or equal to 700 ng/ml. The mean cocaine concentration in non-cocaine deaths where no psychoactive substance other than ethanol was detected was 146 ng/ml. This difference was not statistically significant. However, the average blood benzoylecgonine concentration in the 13 cocaine deaths was significantly higher than in the 19 non-cocaine deaths. A review of combined cocaine and narcotic deaths suggest that the narcotic is the main causative agent in these deaths.     

脑组织与其相关分析推断死亡时间的研究进展

推断死后间隔时间(postmortem interval,PMI)一直是法医学鉴定中需要解决的重要问题之一.可用于推断PMI的尸体检材有很多种,脑组织因其独特的解剖学位置与生理功能,是推断PMI的重要检材之一.本文从三个方面将根据脑组织推断PMI的方法进行综述,包括了通过脑组织的温度、形态特点等尸体现象推断PMI;通过...     

An evaluation of fused silica capillary columns for the screening of basic drugs in postmortem blood: qualitative and quantitative analysis

Fused silica capillary columns (Durabond) have been evaluated for the screening of more than 100 basic drugs in postmortem blood samples. The combination of these columns, nitrogen-phosphorus detectors, and SKF-525A (internal standard) allows for the simultaneous screening and quantitation of several basic drugs such as amphetamines, amitriptyline, and codeine. Approximately 2000 blood samples have been analyzed by this procedure. The use of capillary columns results in excellent baseline stability and this, together with an autosampler and data system, enables unattended overnight operation. "Double peaking" associated with splitless injection can be a problem as can sensitivity for some of the polar drugs; however, with the extraction procedure described and the equipment used, the screening of blood for basic drugs is improved when compared with packed column technology.