Forensic Science and Medicine

Metabolomic analysis of the brain and blood from rats exposed to high-dose chlorpyrifos Hao Wu, Qingtao Wei, Yuzi Zheng, Shiyong Fang, Yingqiang Fu, Linchuan Liao Journal of Forensic Science and Medicine 2019 5(1):1-6 Chlorpyrifos is an organophosphate pesticide used to kill pests such as insects and worms. Wide use of chlorpyrifos has led to serious safety concerns worldwide. Research on the mechanism of action of chlorpyrifos poisoning is continuing. We investigated changes in the small-molecular metabolites in the brain and blood of rats upon exposure to chlorpyrifos at an acute-poisoning dose. Rats were given twice the lowest dose of chlorpyrifos that is lethal for 100% of exposed animals (2 × LD100) and then killed after 2 h. After treatment, gas chromatography-mass spectrometry was used to analyze the metabolomic changes in the brain and blood samples of rats. An increase in blood levels of creatinine and uric acid were noted, along with a decrease in levels of various amino acids. These changes suggested that chlorpyrifos exposure may damage kidney function and cause disorders in amino-acid metabolism of rats. Decreased concentrations of gamma-aminobutyric acid and niacinamide in the brain and increased concentrations of 3-hydroxybutyric acid in rats with acute poisoning by chlorpyrifos were observed, which may suggest oxidative damage in the body.

Estimation of postmortem interval using attenuated total reflectance: Fourier transform infrared spectroscopy in adipose tissues Haohui Zhang, Qi Wang, Kai Zhang, Ruina Liu, Shuanliang Fan, Zhenyuan Wang Journal of Forensic Science and Medicine 2019 5(1):7-12 Estimation of postmortem interval (PMI) is vitally important in forensic investigations. Although many studies have examined the chemical changes of various tissues over time, no reports using spectroscopic methods in adipose tissue are available. In this study, attenuated total reflectance–Fourier transform infrared (ATR–FTIR) spectroscopy was utilized to collect comprehensive biochemical information from human adipose tissues in vitro at different times. Thereafter, mice were used as samples for in vivo experiments for more detailed studies on PMI. Then, partial least squares (PLS) model for PMI estimation was established based on the acquired spectral dataset of mouse samples. The spectral variable associated with C=O arising from lipids and free fatty acids was most susceptible to PMI. Moreover, the PLS model appeared to achieve a satisfactory prediction with a root mean square error of cross-validation of 1.78 days, and the reliability of the model was determined in an external validation set with a root mean square error of prediction of 1.87 days. The study shows the possibility of application of ATR–FTIR methods in PMI estimation using adipose tissue.

Estimation of the postmortem interval using chromatographic fingerprints of volatile organic compounds from muscle Zhiyuan Xia, Beibei Liu, Haimei Zhou, Ping Lv, Jinqi Ma Journal of Forensic Science and Medicine 2019 5(1):13-19 Estimation of the postmortem interval (PMI) is a crucial task in the field of forensic pathology and has unfortunately not been properly resolved. In this study, we analyzed volatile organic compounds (VOCs) in rat muscle samples collected at different PMIs and studied the feasibility of muscle VOC fingerprinting as a new method for PMI estimation. In total, 110 rats were sacrificed and stored at a constant temperature (25°C). Rat skeletal muscle samples were collected at 0–10-day postmortem, and then the VOCs were determined using a method of headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry. The correlations between the VOCs (species and quantities) and PMIs were carefully analyzed and standard muscle VOC fingerprints at 25°C were established for different PMIs. To further test the accuracy of muscle VOC fingerprinting as a method for PMI estimation, ten additional rats with known PMIs were studied. We identified 15 kinds of VOCs and the number of VOC species increased with the PMI. The total peak areas of the VOCs increased significantly with the postmortem day (adjusted R2 = 0.96–0.97). The mean error of the VOC fingerprinting for PMI estimation was 0.5 days and the mean relative error was 8.33%. We concluded that muscle VOC fingerprinting combining the use of VOC species and peak areas is accurate and effective and could be used as an alternative approach for PMI estimation in forensic practice. Although the preliminary results are encouraging, further studies in human cadavers under real case conditions are needed.

A comparative study of human and animal hairs: Microscopic hair comparison and cytochrome c oxidase I species identification Venusia Cortellini, Anna Carobbio, Gloria Brescia, Nicoletta Cerri, Andrea Verzeletti Journal of Forensic Science and Medicine 2019 5(1):20-23 Human and animal hairs have been used in forensic investigations for over a century. Hair is stable under adverse natural conditions; hence, it is often recovered at the crime scene, and it is necessary to determine whether the hair is of human or animal origin. Morphological and genetic characteristics are useful to differentiate human hair from animal hair. In the present study, we analyzed the distinguishing characteristics of hair of various species. In addition, we explore species identification by cytochrome c oxidase I mitochondrial gene analysis. We confirm that both the microscopic and molecular analyses of hairs are useful in forensic investigations.

Determination of sex from the tibia in a contemporary Sri Lankan population Deepthi Nanayakkara, Amal Nishantha Vadysinghe, Lakshika S Nawarathna, Harshana Sampath Journal of Forensic Science and Medicine 2019 5(1):24-28 Determination of sex from the tibial dimensions has been attempted before in different populations. The formulae developed to determine sex of one population are not appropriate to be applied to another. Seven standard variables including the maximum length of tibia, proximal epiphyseal breadth, distal epiphyseal breadth, minimum circumference of shaft, anteroposterior diameter at nutrient foramen, transverse diameter at the nutrient foramen (TDNF), and circumference at the nutrient foramen obtained from 81 adult tibiae (56 male and 25 female) were analyzed to investigate the sexual dimorphism in the tibial dimensions to establish sex estimating formulae from the tibia in a contemporary Sri Lankan population. Results confirmed the existence of sexual dimorphism of the tibia. Discriminant functions obtained resulted in the classification accuracies ranging from 61.9% to 80.2%. The most dimorphic single parameter in males was the TDNF providing an accuracy of 92.9%, while in females, the minimum circumference of shaft provided an accuracy of 70.4%. The best multivariate equation utilizing two tibial dimensions resulted in an accuracy of 80.2% after cross-validation. We envisage that sex estimating formulae established in this study for a contemporary Sri Lankan population will contribute toward the biological profiling and identification of unknown skeletal remains.

Handheld raman spectrometer for the rapid determination of synthetic cannabinoids Ling Zhang, Guoping Li Journal of Forensic Science and Medicine 2019 5(1):29-32 A handheld laser Raman spectrometer was developed to detect 11 synthetic cannabinoid standards. The spectrometer can be connected with a mobile phone by Bluetooth or a computer by a data cable. The Raman spectra of the synthetic cannabinoids AM-694, JWH-019, and nine others were accurately determined by software analysis of characteristic Raman peaks. This technique is highly efficient, accurate, and simple, and it is a valid procedure for rapid on-site investigations of cannabinoids.

Post-traumatic stress disorder: Relationship to traumatic brain injury and approach to forensic psychiatry evaluation Ye-Fei Chen, Hu Zhao Journal of Forensic Science and Medicine 2019 5(1):33-39 Posttraumatic stress disorder (PTSD) has an important and complex relationship with traumatic brain injury (TBI). The prevalence of comorbid PTSD and TBI is increasing in both military and civilian populations. Moreover, TBI has emerged as an important risk factor for the development and manifestation of PTSD. Meanwhile, PTSD is also a significant mediator of the negative sequelae of TBI. PTSD and TBI, especially mild TBI (mTBI), have overlapping neural substrates and neuroanatomical functional features. Given that comorbid PTSD and TBI remain a challenge for forensic psychiatry evaluation, we review the relationship between the two disorders and discuss special considerations during evaluation of the condition.

Chasing truth from the perspective of history Luping Zhang Journal of Forensic Science and Medicine 2019 5(1):40-56 This paper analyzes the development processes of the text on the narration of case facts until it finally be ascertained in trial. It is a subtle evolution process from evidence to the list of events and eventually to the factual text. It is a complex task to distinguish the content that would be inexorable once being proved and to reach consensus from the content that could only be presented through rhetoric. Meanwhile, this paper compares some existing documents of chronicles, annals, and narrative history with the events list and the factual text in Cui Yingjie Case so as to illustrate how the vertical evolution takes place in the description of the case as well as the differences of all evolution stages in judicial practice.

Key technology research for mobile police terminal fingerprint collection for quick comparison using automated fingerprint identification system Shengjun Sun, Yaomin Gu, Lan Wang, Ping Gu, Yuankai Li Journal of Forensic Science and Medicine 2019 5(1):57-60 When the face of the inspected person and the photograph on their identification (ID) card cannot be clearly matched, the individual is undocumented, or the ID is forged, it is often difficult for the on-site police to respond in time. This study proposes a number of key technologies for collecting fingerprints at mobile terminals for fast comparison using an automated fingerprint ID system (AFIS). These technologies ensure intelligent mobile fingerprint collection and allow the transmission of fingerprint information from the terminal to AFIS, over a wireless public security network for real-time fingerprint comparison. This study also analyzes the feasibility and effectiveness of the proposed technologies for system design and the applicability of fingerprint ID algorithms. The system achieved good results in a test by the Shanghai Public Security Bureau Criminal Investigation Corps.

Alexandros Sfakianakis
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alsfakia@gmail.com