Τετάρτη 18 Σεπτεμβρίου 2019

Degradation of β-Actin mRNA and 18S rRNA in mouse spleen cells after death
Zhiyuan An, Feng Li, Dong Zhao

Journal of Forensic Science and Medicine 2019 5(3):123-129

We observed degradation of β-actin mRNA and 18S rRNA in mouse spleen cells under constant temperature conditions in the different temperature group during postmortem intervals (PMIs) of 0–72 h. Thirty-nine mice were sacrificed by cervical dislocation and kept at constant temperatures of 10°C, 15°C, 20°C, 25°C, and 30°C. From 0 to 72 h after death, total RNA in spleen cells was extracted every 6 h. The cycle threshold (Ct) values of β-actin mRNA and 18S rRNA were obtained by real-time-quantitative polymerase chain reaction. The results showed that, under the conditions of different and constant temperatures after mouse death at 72 h, the Ct values of β-actin and 18S, Ct ratios of β-actin to 18S, and relative ratios of β-actin to 18S were significantly correlated with PMI. In addition, the relative degradation rates of β-actin and 18S appeared to change from fast to slow with the increase of temperature. By interpolation and fitting analysis of the data, we obtained a ternary quintic equation of the relationship between the change in the relative ratios and PMI, which can be used to infer PMI within a certain temperature range (10°C–30°C).

Fe3O4 nanoparticle-modified multi-walled carbon nanotubes for the determination of synthetic pyrethroids in human blood
Cui Yanhua, Shen Weidong, Yang Fan, Pan Yaoyue, Zhang Suling, Yao Weixuan

Journal of Forensic Science and Medicine 2019 5(3):130-135

In this study, a sensitive and rapid magnetic solid-phase microextraction (MSPE) procedure based on Fe3O4 nanoparticle-modified, multi-walled carbon nanotubes combined with a gas chromatography/electron capture detector (GC/ECD) was developed to quantify pyrethroids in human blood samples. This study compared liquid–liquid extraction and solid-phase extraction methods and found that the MSPE-GC/ECD method had many advantages, such as high recovery rate, high extraction efficiency, high detection sensitivity, low limit of detection, and simple operation. It can meet the actual requirements for the determination of synthetic pyrethroids in human blood.

Rapid screening of nine illicit drugs in human blood and urine by direct analysis in real-time mass spectrometry
Ying Zhang, Wenfang Zhang, Guobin Xin, Li Liu, Xiaokun Duan, Charles Liu

Journal of Forensic Science and Medicine 2019 5(3):136-140

We aimed to establish for the rapid detection of morphine, O6-monoacetylmorphine, heroin, codeine, cocaine, methamphetamine, ketamine, methadone, and dolantin in human blood and urine by direct analysis in real-time coupled with tandem mass spectrometry (DART-MS/MS). These samples were extracted by acetonitrile-methanol (V/V = 4:1), using DART 12 Dip-it automatic sampling system. They were injected at 400°C, and analyzed by positive ion and multiple reaction monitoring mode. The detection limits of morphine, O6-Monoacetylmorphine, heroin, codeine, cocaine, methamphetamine, ketamine, methadone, and dolantin were 100, 50, 50, 100, 20, 20, 10, 1, and 0.01 ng/mL, respectively. The practical cases contained methamphetamine, codeine, cocaine, and O6-monoacetylmorphine were detected accurately and rapidly. The method has the advantages of high sensitivity and good accuracy. The sample processing is simple and can be analyzed in a short time. This method is suitable for the analysis of morphine, O6-monoacetylmorphine, heroin, codeine, cocaine, methamphetamine, ketamine, methadone, and dolantin in some practical cases.

Estimating a reliable cutoff point of 1-propanol in postmortem blood as marker of microbial ethanol production
Vassiliki A Boumba, Nikolaos Kourkoumelis, Kallirroi Ziavrou, Theodore Vougiouklakis

Journal of Forensic Science and Medicine 2019 5(3):141-146

The interpretation of the ethanol analysis results in postmortem cases may be challenging when the origin of postmortem ethanol (antemortem ingestion or microbial production) is under dispute. In this study, we investigated the suitability of blood 1-propanol cutoff concentration as a reliable marker for the discrimination between “positive” and “negative” for postmortem ethanol production (PEP) autopsy blood samples by performing receiver operating characteristic (ROC) analysis. The results indicated that a threshold 1-propanol concentration of 0.104 mg/dL had an area under the curve of 0.90 (standard deviation = 0.03), sensitivity of 79%, and specificity of 91% for predicting PEP with 95% confidence interval. This means that the positive for PEP autopsy blood samples yield significantly differentiated PEP than approximately 90% of the controls. The estimated concentration of 1-propanol is an applicable threshold (cutoff) value for autopsy blood 1-propanol to discriminate between “positive” and “negative” samples for PEP. We named this threshold 1-propanol concentration (of 0.104 mg/dL) as “1-propanol criterion.” In an effort to test its applicability to postmortem cases, we evaluated blood ethanol and 1-propanol from 222 postmortem cases records. The results showed that 10% of the tested samples were positive for PEP, and only a few of them were from bodies with signs of putrefaction at autopsy. This finding indicates that PEP in a corpse could take place before the appearance of obvious putrefaction. We suggest the ROC-based calculation of the 1-propanol cutoff concentration, at 0.104 mg/dL, as an effective method for “flagging” blood samples as positive for PEP irrespectively of the presence or not of putrefaction.

Fatal overdoses involving carfentanil: A case series
Nicholas J Corsi, Ljubisa J Dragovic

Journal of Forensic Science and Medicine 2019 5(3):147-150

Carfentanil, an ultrapotent analog of fentanyl, has invaded the street drug market, unbeknownst to many heroin users. About 10,000 times more potent than morphine, it was initially suspected that 20 μg of the substance was lethal. In this case series, we present 17 confirmed carfentanil overdoses in Michigan, with a primary focus on the concentration levels. Through a retrospective review, each public death reported in Oakland County, Michigan, with a subsequent toxicology report was investigated for suspected carfentanil use. To characterize each fatality, the autopsy results were collected, including the postmortem findings at scene and the decedent's medical and social history. Carfentanil levels were measured through liquid chromatography and tandem mass spectrometry (LC-MS-MS) by National Medical Services (NMS) Laboratories. Our case series found postmortem carfentanil concentrations as low as 10 ng/mL, with a mean concentration of 0.387 ng/mL. Ultimately, there are implications on law enforcement, first responders, and health care providers when dealing with this emerging illicit substance, and there is an alarmingly high mortality rate associated with the abuse of carfentanil.

Sex determination using mandibular canine among Northeastern Nigerian population
Saleh Nuhu, Babagana Mohammed Dalori, Lawan Hassan Adamu, Isyaku Ibrahim, Maryam Nasir Aliyu

Journal of Forensic Science and Medicine 2019 5(3):151-155

Establishing a person's identity is important for both legal and humanitarian purposes. Sex determination is a key characteristic used in the identification of a deceased individual. The aim of this study was to determine sex by using mandibular canines among individuals in the Northeastern Nigerian population. Two hundred and eight individuals (102 men and 106 women) participated in this study. The mesiodistal widths of the mandibular canines and intercanine distances were measured using a vernier caliper and a divider. Step-wise logistic regression analyses were used to determine sex based on mandibular parameters. Male participants had significantly higher mandibular mesiodistal width than female participants. Similarly, the canine index was significantly higher in male participants than in female participants. The mesiodistal width of the left mandibular canine exhibited the highest sexual dimorphism (9.78%) and was the best characteristic for use in determining sex, with an accuracy of 75%. Among the Northwestern Nigerian population, sex can be most accurately determined using the mesiodistal width of the left mandibular canine.

A study on the model of fact-finding in criminal investigation
Mohan Pan, Kaixin Zheng

Journal of Forensic Science and Medicine 2019 5(3):156-163

Fact-finding, as the foundation of a judicial decision, has been an important consideration in China's judicial reform. This study introduces the theory of evidence-based information and falsification methods in the fact-finding procedure of criminal investigations and proposes a paradigm for fact-finding using combined pairs of approaches: individual evidence examination and global analysis, the objective basis and subjective perception of fact-finders, and methods of verification and falsification. The working procedure of the paradigm is illustrated with the objective of making a contribution to the improvement of the existing model of fact-finding in the criminal justice process.

A case of suicide with multiple stab wounds
Ganesh Raj Selvaraja, Poh Kuang Jih, Kunasilan Subramaniam, Norliza Binti Ibrahim

Journal of Forensic Science and Medicine 2019 5(3):164-167

Multiple stab wounds are very common features of homicidal stabbing. The common findings differentiating homicidal and suicidal stabbing are well described in the medical literature. Among the features mentioned are location, shape, and direction of the wounds. These features are vital in differentiating suicide from homicide. However, this case has an unusual presentation. We discuss the importance of interpretation and differentiation of the stab wounds to determine the manner of death and facilitate the investigation. A 29-year-old male presented with multiple stab wounds. There was no witness at the time of the incident. The body was discovered in his room with pools of blood. A knife was present on his body. No tentative cuts were present on the body. Scene investigation and postmortem examination determined the cause and manner of death.

Profile interpretation of extremely long alleles at DYF387S1 and DYS447 migrated into allele range of adjacent loci
Wei-Wei Wu, Honglei Hao, Dejian Lu, Hailun Nan

Journal of Forensic Science and Medicine 2019 5(3):168-171

Two rare cases of long alleles at Y-chromosome short tandem repeat (Y-STR) loci (DYF387S1 and DYS447) were identified when two father–son pairs were analyzed by multiplex amplification. “Null alleles” were observed at DYF387S1 and DYS447, and duplicated alleles were displayed at DYS533 and DYS19. We secondly amplified DYF387S1, DYS533, DYS447, and DYS19 loci by singleplex polymerase chain reaction (PCR) and sequence analysis of the long alleles at DYF387S1 and DYS447 loci. The results showed that alleles from DYF387S1 (allele 55) and DYS447 (allele 41) were longer than their common sizes in the allelic ladder ranges (33–42 for DYF387S1 and 18–30 for DYS447) and located in the neighboring loci (DYS533 and DYS19, respectively). Therefore, to identify these cases involving this unusual phenomenon, not only re-amplification using the same kit but also additional amplification (using alternative multiplex kits with different adjoining markers or additional singleplex PCR amplification) should be performed to avoid misinterpreting Y-STR profiles.

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