Diagnosis of lethal poisoning with some substances used by toxicomaniacs

The authors analyze 62 expert conclusions on deaths from acute and chronic poisoning with various toxic substances used by toxicomaniacs. Forensic medical examination of corpses and forensic chemical analysis identified drugs, toluene, freon, organophosphorus compounds, and other toxins.     

Method of determining methemoglobin in cadaver blood

Poisoning with methemoglobin toxins are not rare in forensic medical practice, but there is still no reliable method for measuring methemoglobin in cadaveric biological fluids and tissues. The author investigated factors affecting evaluation of natural amounts of methemoglobin in the blood, compared several methods for methemoglobin measurements, and developed qualitative characteristics indicating the presence of methemoglobin in cadaveric blood. A rational method for measuring methemoglobin in the blood, blood clots, and tissues is offered for forensic chemical and biochemical evaluations.     

Drug screening in clinical or forensic toxicology: are there differences?

Legal and medical practitioners need to remember that, with respect to drug analysis, there are two distinct disciplines in analytical toxicology concerned with human biological matrices, namely clinical and forensic toxicology. Both fields use similar analytical techniques designed to detect and quantify drugs, chemicals and poisons in fluids or tissues. In clinical toxicology, analytical results help to specify the appropriate treatment of a poisoned or intoxicated patient. In forensic toxicology, the results often play a vital role in determining the possible impairment or behavioural changes in an individual, or the contribution of drugs or poisons to death in a medico-legal investigation. This column provides an overview of the similarities and differences inherent in clinical and forensic toxicology.     

Isolation and Individualization of Conceptus and Maternal Tissues from Abortions and Placentas for Parentage Testing in Cases of Rape and Abandoned Newborns*

Abstract: Abortion specimens are often submitted to forensic laboratories as the only piece of physical evidence in rape and incest cases. The recovery of conceptus tissues from this evidence permits the use of paternity testing to evaluate suspects. In cases of abandoned newborns, the recovery of maternal tissue from the placenta allows for the direct comparison of genetic profiles between the suspected mother and the biological mother. We report on the identification and isolation of conceptus tissues from embryonic‐ and fetal‐period abortions, and maternal tissues from delivered placentas, by gross and low‐magnification examination with manual dissection. Hundreds of single‐source samples have been successfully recovered by this method and short tandem repeat typed using standard forensic procedures. We additionally describe extraembryonic tissues that can be recovered and typed in the absence of the embryo proper. We conclude that an expertise and protocols can be developed by forensic laboratories for the routine analysis of this evidence.     

Fly larvae: a new toxicological method of investigation in forensic medicine

Toxicological analyses on a putrefied cadaver are sometimes difficult to achieve because of the absence of blood and urine. In this study, maggots, living material, are proposed as a new medium of investigation in forensic medicine. Five drugs (triazolam, oxazepam, phenobarbital, alimemazine, and clomipramine) were identified and assayed in some tissues of a putrefied cadaver and in the maggots found on and in the body.     

allo-HSCT受者DNA嵌合状态研究进展及法医学意义

随着医疗新技术的迅速发展,造血干细胞移植在临床上的用途越来越广泛。移植后供者源细胞几乎存在于受者所有组织,必然对个人识别和亲权鉴定产生重要影响,应引起法医工作者的重视,避免因此而产生错误的司法鉴定结论。本文就近年来allo-HSCT受者不同组织DNA嵌合状态的研究进展及其对法医物证鉴定的影响作一综述,希望能对相关研究和实践提供参考。     

The stability of tetramine, morphine and meperidine in formalin solution.

The stability of tetramine, morphine and meperidine in formalin solution is an important factor for drug analysis in forensic investigation. In this paper, the tissues (liver, kidney, lung and heart) from poisoned rabbits were immersed in 50 ml 10% formalin solutions for 4 months before examination. We compared the levels of tetramine, morphine, meperidine and the main metabolite normeperidine, measured by GC/NPD or GC-MS, in frozen rabbit tissues, formalin-fixed rabbit tissues, and formalin solution. There was a decrease in the levels of tetramine, morphine, meperidine in formalin-preserved tissues compared with the levels of these drugs in the frozen tissues. It is suggested that the formalin-fixed tissues and formalin solution should be analyzed at the same time to assure the accurate results.     

Release of tissue paraquat into formalin solution during fixation

Formalin-fixed tissues and formalin solutions are among the most frequently found materials in pathology and forensic science laboratories. However, these materials are seldom used for the identification of poisons for forensic toxicology purposes. In this study, the possibility that paraquat may be released from formalin-fixed tissues during the fixation process was investigated. However, because of the interference of formaldehyde on the reduction of paraquat with dithionite reagent, paraquat in formalin solutions was treated with ion-pair column chromatography and then determined by measuring the derivative spectrum of reduced paraquat. The results show that the interference of formalin on paraquat determination has been eliminated by the proposed method. Furthermore, a study on the formalin solutions of fixed organs in cases with suspected paraquat intoxication revealed that portions of tissue paraquat had been released into formalin during the fixation process. Moreover, the paraquat levels in formalin increased with increased storage time. Therefore, these data suggest that the combined concentrations of paraquat in the formalin-fixed tissues and formalin solutions might reflect more reliably the total paraquat in the postmortem tissues. This investigation could be of value to the forensic toxicologist, especially in cases in which no fresh tissue samples are available for analysis.     

虚拟解剖技术在法医学中的应用

虚拟解剖是一种非侵入性的新型“解剖”技术,它利用影像学技术构建人体器官组织的三维立体图像,为判断死亡原因和死亡方式提供线索。由于这一技术具有无侵入性、客观、准确的特点,目前已成为发达国家法医病理学的研究热点。本文对虚拟解剖技术的原理、优缺点、研究进展及在我国开展研究应用的可行性进行综述。     

Cause of death and drug use pattern in deceased drug addicts in Sweden, 2002-2003

Compared with their contemporaries, individuals abusing illicit drugs suffer a higher risk of premature death. In Sweden, a simple protocol for registration of fatalities among abusers of alcohol, pharmaceuticals, illicit drugs, or other substances, has been used by the forensic pathologists since 2001. This routine was introduced to allow for an evaluation of the cause and manner of death, and patterns of abuse among different groups of abusers. We explored the data on drug abusers (i.e. abusers of illicit drugs) subjected to a forensic autopsy 2002-2003. The Swedish forensic pathologists examined 10,273 dead victims during the study period and 7% (743/10,273) of the cases were classified as drug abusers. Toxicological analyses were carried out in 99% (736/743) and illicit drugs were detected in 70% (514/736) of these. On average, 3.8 substances (legal or illegal) were found per case. The most common substances were ethanol and morphine, detected in 43 and 35% of the cases, respectively. When exploring the importance of the different substances for the cause of death, we found that the detection of some substances, such as fentanyl and morphine, strongly indicated a poisoning, whereas certain other substances, such as benzodiazepines more often were incidental findings. In total, 50% (372/743) died of poisoning, whereas only 22% (161/743) died of natural causes. Death was considered to be directly or indirectly due to drug abuse in 47% (346/743), whereas evidence of drug abuse was an incidental finding in 21% (153/743) or based on case history alone in 33% (244/743). We believe that this strategy to prospectively categorize deaths among drug addicts constitutes a simple means of standardizing the surveillance of the death toll among drug addicts that could allow for comparisons over time and between countries.     

A simple and cost-effective method for preparing DNA from the hard tooth tissue, and its use in polymerase chain reaction amplification of amelogenin gene segment for sex determination in an Indian population

The use of teeth as an important resource in the analysis of forensic case history by polymerase chain reaction (PCR) or other related methods has been reported. However, a major drawback in using teeth has been that the DNA is present only in trace amounts, and the methods to recover DNA from the flinty material have not been efficient or cost effective. In this report, we describe a method to prepare DNA from the hard tooth tissues. Our studies show that ultrasonication of teeth samples yields sufficient amounts of good quality DNA useful for PCR-based diagnostic methods. The teeth could serve as a reliable source of DNA for amplification-based forensic methods in sex determination. DNA could be obtained from any tooth, regardless of the age of subject. Furthermore, by using the AMEL gene-based primers in PCR, we have shown that the AMEL gene serves as a good marker for sex determination in the Indian population. In our study, the PCR-based method was sensitive and proved to be successful for sex determination with a complete specificity.     

Validation of PrepFiler™ forensic DNA extraction kit (Applied Biosystems)

The PrepFiler™ is a new kit recently introduced by Applied Biosystems for DNA extraction from a wide range of forensic samples. In the present study we tested the performance of PrepFiler™ kit against other commonly used commercially available kits on a variety of real forensic casework samples: bloodstains on different substrates, washed bloodstains, semen stains, saliva stains, hairs, bones, tissues, nails, prints after chemical treatments, skin swabs.     

从ICE看缴获毒品检验的发展趋势

当今世界缴获毒品检验使用的技术发展迅速,为促进各国相关实验室间的技术交流,国际合作测试项目(ICE)已开展多次,本文通过对ICE缴获毒品组测试结果和总体评估报告进行分析,针对国际上缴获毒品检验常用技术方法及发展趋势进行分析,希望能为相关研究和实践提供一些参考和借鉴.     

毛发中毒品分析

毛发分析在法庭毒品分析领域有其独特的优势,很多国家的法化学实验室,毛发分析已成为毒品检测的常规操作,并已得到了法庭的承认、采纳。本文对毒品进入毛发的机制、毛发的现场勘查、毛发中毒品分析程序、毛发中毒品分析结果的评判进行了综述。简单地介绍了毛发在现场勘查中采取、包装、送检的基本方法和技术人员在操作过程中的注意事项,以及针对毛发检验中的特殊技术处理;另外,介绍了毛发中毒品分析的特点,通过分析毛发毒品的药理机制,总结出了一些高效、便利、快速的毒品分析方法,并对各种方法进行了介绍,得出了毛发中毒品分析结果的一些特点。     

司法鉴定改革：社会价值与发展方向

司法鉴定改革已经走过了极不平凡的十余年。全国人大常委会《关于司法鉴定管理问题的决定》（以下简称《决定》）实施以来。司法鉴定事业有了很大的发展，取得了可喜的成果。本文就司杀鉴定改革的社会价值与发展方向进行了有益的探索。展示了司法鉴定改革对其他社会改革的启迪价值。     

Review of analytical methods for screening and quantification of fentanyl analogs and novel synthetic opioids in biological specimens

Fentanyl, fentanyl analogs, and other novel synthetic opioids (NSO), including nitazene analogs, prevail in forensic toxicology casework. Analytical methods for identifying these drugs in biological specimens need to be robust, sensitive, and specific. Isomers, new analogs, and slight differences in structural modifications necessitate the use of high-resolution mass spectrometry (HRMS), especially as a non-targeted screening method designed to detect newly emerging drugs. Traditional forensic toxicology workflows, such as immunoassay and gas chromatography mass spectrometry (GC–MS), are generally not sensitive enough for detection of NSOs due to observed low (sub-μg/L) concentrations. For this review, the authors tabulated, reviewed, and summarized analytical methods from 2010–2022 for screening and quantification of fentanyl analogs and other NSOs in biological specimens using a variety of different instruments and sample preparation approaches. Limits of detection or quantification for 105 methods were included and compared to published standards and guidelines for suggested scope and sensitivity in forensic toxicology casework. Methods were summarized by instrument for screening and quantitative methods for fentanyl analogs and for nitazenes and other NSO. Toxicological testing for fentanyl analogs and NSOs is increasingly and most commonly being conducted using a variety of liquid chromatography mass spectrometry (LC–MS)-based techniques. Most of the recent analytical methods reviewed exhibited limits of detection well below 1 μg/L to detect low concentrations of increasingly potent drugs. In addition, it was observed that most newly developed methods are now using smaller sample volumes which is achievable due to the sensitivity increase gained by new technology and new instrumentation.     

Heteroplasmy in hair: differences among hair and blood from the same individuals are still a matter of debate

The analysis of mitochondrial DNA (mtDNA) is a useful tool in forensic cases when sample contents too little or degraded nuclear DNA to genotype by autosomal short tandem repeat (STR) loci, but it is especially useful when the only forensic evidence is a hair shaft. Several authors have related differences in mtDNA from different tissues within the same individual, with high frequency of heteroplasmic variants in hair, as also in some other tissues. Is still a matter of debate how the differences influence the interpretation forensic protocols. One difference between two samples supposed to be originated from the same individual are related to an inconclusive result, but depending on the tissue and the position of the difference it should have a different interpretation, based on mutation-rate heterogeneity of mtDNA. In order to investigate it differences in the mtDNA control region from hair shafts and blood in our population, sequences from the hypervariable regions 1 and 2 (HV1 and HV2) from 100 Brazilian unrelated individuals were compared. The frequency of point heteroplasmy observed in hair was 10.5% by sequencing. Our study confirms the results related by other authors that concluded that small differences within tissues should be interpreted with caution especially when analyzing hair samples.     

The determination of drugs and their substitutes in human hairs

In recent years it has become possible to detect organic pharmaceuticals and drugs in a few milligrams of a person's hair, using modern analytical methods (RIA, GC/MS, GC), whether this person has taken narcotics and other drugs in past times. With the aid of hair analysis it is possible to examine the drug career of a drug addict for up to 1 year, and sometimes for a longer time. This is mostly of great importance in criminalistics and forensic medicine, in the criminal retrospective examination of addicts.     

Screening and quantification of antipsychotic drugs in human brain tissue by liquid chromatography-tandem mass spectrometry: application to postmortem diagnostics of forensic interest

A quantitative LC-MS/MS method has been developed for the simultaneous determination of 17 antipsychotic drugs in human postmortem brain tissue. Sample preparation was performed using Hybrid Solid Phase Extraction-Precipitation technology for the removal of endogenous protein and phospholipid interferences. The chromatographic separation was performed for 16 min on a C8 column, which used a gradient elution of formate ammonium and acetonitrile, and a flow rate gradient. Triple quadrupole mass spectrometry was employed to generate tandem mass spectrometric (MS/MS) data of the target analytes to select the ion m/z signals. Quantitation of the analytes was performed by operating in the dynamic multiple reaction monitoring (dMRM) mode using an electrospray ionization interface. Calibration curves prepared in the spiked brain tissue were linear in the range 20-8000 ng/g (r(2)>0.993) for all drugs (except olanzapine). Within- and between-day coefficients of variation were lower than 25% for all drugs at the LOQ. The LOQ in the matrix ranged between 2 ng/g and 80 ng/g. The method was successfully applied to the unequivocal identification and accurate quantification of antipsychotic drugs in human postmortem brain tissues: therefore, this method can be used in forensic investigations.