Computer-assisted interpretation in forensic toxicology: morphine-involved deaths

Case data from 200 morphine-involved deaths (Spiehler, V. and Brown, R., Journal of Forensic Sciences, Vol. 32, No. 4, July 1987, pp. 906-916) were analyzed for patterns and relationships using artificial intelligence (AI) computer software. Case parameters were blood unconjugated morphine, blood, brain, and liver total morphine, sex, age, frequency of use, time of death after injection, cause of death, and presence of other drugs. The programs used were Expert 4 (Biosoft-Cambridge), BEAGLE (Warm Boot, Ltd.), and KnowledgeMaker (Knowledge Garden Inc.). Interpretation was defined as estimating the dose, response, and time after drug dosing. The AI programs were used to advise on time and response outcomes for cases, to calculate the probability of the estimate being true, to develop rules for interpretation of morphine-involved cases, and to diagram a decision tree. On known cases the AI programs were successful 70 to 90% of the time in classifying the cases as to response and time. No data on dose were available in this database. The success rate in individual cases was proportional to the program-estimated probability. All three programs found the case parameters of most value in predicting response to be blood unconjugated morphine, blood total morphine, and liver total morphine. The case data most useful in estimating time of death since drug injection were blood unconjugated morphine, percent unconjugated morphine in blood, and brain total morphine. The rule induction programs found that morphine overdoses were characterized by blood unconjugated morphine greater than 0.24 micrograms/mL, liver morphine greater than 0.50 to 0.75 micrograms/g, brain morphine greater than 0.08 micrograms/g or greater than blood unconjugated morphine, and percent blood unconjugated morphine greater than 37%. Rapid deaths were characterized by percent unconjugated morphine greater than 44 to 50%; blood unconjugated morphine, as a function of other drugs present, greater than 0.09 to 0.21 micrograms/mL; and brain total morphine greater than 0.16 to 0.22 micrograms/g. This work demonstrates that inexpensive AI programs commercially available for personal computers can be useful in interpretation in forensic toxicology.     

Postmortem forensic toxicology of trazodone

Trazodone is a popular antidepressant medication that has been available for approximately 30 years. It has a reputation as a safe drug with relatively few reported fatalities attributed solely to it. We review the pharmacology and forensic toxicology of trazodone and report toxicology and cause and manner of death in a series of 37 deaths in which trazodone was detected. Although the normal upper therapeutic blood concentration for trazodone is about 2 mg/L, fatalities are rarely attributed solely to it at blood concentrations below 9 mg/L. Considering the pharmacology of the drug, potential interactions between other drugs with serotonin reuptake properties need to be considered, as does the increased susceptibility to the toxic effects in patients with pre-existing heart disease. In the cases reviewed, none were attributed solely to trazodone, although trazodone was frequently present together with other serotonergic drugs, such as the selective serotonin reuptake inhibitors like fluoxetine and sertraline. Ten cases had blood trazodone concentrations above 2 mg/L. Of these cases, trazodone played a primary role in the death of three subjects, with blood concentrations all greater than 9 mg/L. We confirm the conclusions of others that trazodone is a relatively safe drug except in massive overdose, although its toxicity may be influenced by the presence of other drugs and underlying pathophysiology.     

代谢组学及其在法医毒理学中的应用

代谢组学是上世纪90年代中期发展起来的研究细胞和生物体的所有代谢中间体和终产物的一门新兴学科。其研究对象一般为分子量在1 000Da以下的小分子。代谢组学通过对生物体系中的小分子化合物进行定性定量分析,解析生物体系的代谢途径并揭示内源性小分子化合物与毒性、疾病、生命活动规律等的相互关系。本文综述代谢组学的概况及其在法医毒理学中的应用现状,为相关研究和应用提供参考。     

Audit in forensic pathology

Autopsy numbers in Australian hospitals have declined markedly during the past decade despite evidence of a relatively static rate of demonstrable clinical misdiagnosis during this time. The reason for this decrease in autopsy numbers is multifactorial and may include a general lack of clinical and pathologic interest in the autopsy with a possible decline in autopsy standard, a lack of clinicopathologic correlation after autopsies, and an increased emphasis on surgical biopsy reporting within hospital pathology departments. Although forensic autopsies are currently maintaining their numbers, it is incumbent on forensic pathologists to demonstrate the wealth of important information a carefully performed postmortem examination can reveal. To this end, the Pathology Division of the Victorian Institute of Forensic Medicine has instituted a program of minimum standards in varied types of coroner cases and commenced a system of internal and external audit. The minimum standard for a routine, sudden, presumed natural death is presented and the audit system is discussed.     

近十年法医毒物分析和法医毒理学研究热点统计分析

借助Bicomb 2.0软件及SPSS 19.0软件对近十年国内外法医毒物分析和法医毒理学的研究热点进行分析,结果表明国内研究热点可以分为5类:分类1为毒品和精神活性物质的提取方法和样品稳定性研究;分类2为镇静催眠药的代谢和死后分布研究;分类3为农药的快速检测方法开发;分类4为分析方法的完善和标准化研究;分类5为新型毒物γ-羟基丁酸和合成大麻素的检测方法研究。国际研究热点分为6类:分类1为传统精神活性物质、乙醇和样品稳定性的研究;分类2为芬太尼的分析研究;分类3为氰化物的检测和毒理学研究;分类4为新型精神活性物质的检测图库建立和分析方法开发;分类5为镇静催眠药的研究;分类6为丁烷及其引起的猝死案例的研究。同时,对近十年国际合作法医毒物学研究进行了网络可视化分析。     

Fly larvae and their relevance in forensic toxicology

Toxicological analyses on a putrefied cadaver are sometimes difficult to perform because of the absence of blood and urine. In this study, fly larvae, being living material, are proposed as a new medium of investigation in forensic toxicology. Bromazepam and levomepromazine were identified and assayed in the remains of cerebral tissue, in the clavicle of a putrefied cadaver, and in the fly larvae found on and in the corpse.     

Importance of information in forensic toxicology.

Information in forensic toxicology plays a very important role. The forensic pathologist usually seeks toxicologic analyses on basis of the information available at the time of the medicolegal autopsy. Such information may be obtained from different sources: hospitals, authorities, relatives, friends, or neighbors of the deceased and, obviously, macroscopic findings at the time of the autopsy. In order to evaluate the relative importance of these different sources of information, the authors have studied, retrospectively, results of 580 postmortem examinations performed at the Institute of Legal Medicine of Lisbon, wherein toxicologic analyses had been requested. These cases pertain to the years 1987 and 1988, but do not include alcohol determination in the blood in cases of traffic accidents. In 274 (47.4%) of the 580 cases, there were positive findings while in the remaining 306 (52.6%) findings were negative. In cases with positive findings, circumstances and factors, which may have influenced the pathologist's decision to request toxicologic analysis, are discussed. In more than half the cases, hospital information was the decisive factor, while in approximately 25% of the cases, autopsy findings were the justification. In contrast, it is worth mentioning that in approximately 45% of the cases with analytical negative results, requests were made, in cases of blank autopsies, for toxicologic analyses in order to exclude the possibility of poisoning. It is interesting to note that in the same proportion requests were justified on grounds of hospital information. Some of the factors that may explain this apparent discrepancy are discussed. Finally, the relevance of background information is emphasized at the level of the interpretation of analytical results, whether positive or negative.(ABSTRACT TRUNCATED AT 250 WORDS)     

Extraction procedures for some common drugs in clinical and forensic toxicology.

The results of four extraction systems for 86 drugs are reported. These systems were investigated with the view to obtaining a rapid, reliable, and efficient extraction technique in clinical and forensic toxicology.     

The forensic pathology specialty certifications

The subspecialty of pathology known as forensic pathology has been certified by the American Board of Pathology since 1959, when the first examinations were offered in New Orleans, Louisiana, U.S.A. This article provides information on those who have been certified since 1959 and also the requirements for this certification by the American Board of Pathology.     

法庭科学毒物分析实验室质量控制的发展与现状

本文综述了国内外法庭科学毒物分析实验室质量控制的发展及一般要求,并讨论了我国毒物分析实验室质量控制中存在的不足和应对措施。     

The United Kingdom and Ireland association of forensic toxicologists forensic toxicology laboratory guidelines (2018)

In 2010, the United Kingdom and Ireland Association of Forensic Toxicologists (UKIAFT) created forensic toxicology laboratory guidelines. This represents a revision of those guidelines as a result of the changing toxicological and technical landscape.     

Microwave processing and ethanol-based fixation in forensic pathology

An ethanol-based fixative (FineFIX) has been used, together with rapid microwave-stimulated processing, in postmortem material, resulting in a rapid fixation and processing of the tissues with morphology, histochemical stains, and immunocytochemistry comparable to formalin-fixed material. Furthermore, this alternative fixation gives better DNA recovery in higher amounts if compared with DNA extracted from formalin-fixed tissue, particularly advantageous in forensic pathology.     

A proposed dissection procedure for vertebral arteries in forensic pathology

Vertebral artery removing constitutes a significant forensic pathology challenge. Dissection techniques during head-neck autopsy are based on anterior approach, a difficult method, which is unable to assess the transverse part of the artery. This work presents an original and simple method for dissecting vertebral arteries by a posterior approach, opening the vertebroarterial canal through the spinal canal without any special equipment. Once the spinal cord is removed, the transversarium foramens are opened by an internal cut at the pedicle and an external cut at the transverse process. This enables us to visualize vertebral arteries in its entirety. The method improves both the examination of the upper extracranial segment of the vertebral artery and the neuropathological study when arterial injury is suspected. Applying this method routinely is both feasible and useful in suspected cases of vertebral artery trauma and could contribute to assess more precisely the actual incidence of this injury.     

微波在法医病理学免疫组化染色中的应用

将松下牌微波炉（microwave oven，MWO）应用于20例人体尸检材料（心、脑）的链霉菌素一生物素免疫组化染色（LSAB法），检测了10种心、脑组织抗原．MWO应用于尸检材料免疫组化染色时的使用要点为（1）抗原的修复：切片置于0.01M枸椽酸盐缓冲液（PH6．0）中，DEF档（210W），10min，温度92－98℃；（2）滴加正常血清、一抗、二抗及SP复合物后，于LOW档（70W），5min，温度20～37℃,其它步骤与标准方法一致．结果表明：MWO的应用有助于封闭抗原的修复，提高阳性染色程度，降低背景着色，缩短染色时间．