Hair as a specimen to document tetramethylene disulfotetramine exposure

Tetramethylene disulfotetramine (tetramine) is a rodenticide that has been banned for many years in China. Since 2005, inhabitants of a village in the Henan Province have been suffering from grand mal seizures. To investigate the possibility of tetramine as the cause, we developed a method to determine tetramine in human hair. Sample preparation involved external decontamination, frozen pulverization, and ultrasonication in 2 mL ethyl acetate in the presence of cocaine-d3 as an internal standard. The method exhibited good linearity; calibration curve was linear over a range of 0.1-20 ng/mg hair. The limit of detection for the assay was 0.05 ng/mg hair. Except for one subject (No. 4), all head and pubic hair samples were positive for tetramine. The concentrations of tetramine in pubic hair were significantly higher than those in the same subjects' head hair samples. Because of a long retention in body, segmental head hair analysis cannot provide an accurate exposure history of tetramine in the body.     

Heteroplasmy in Hair: Study of Mitochondrial DNA Third Hypervariable Region in Hair and Blood Samples*†

Abstract: Mitochondrial DNA (mtDNA) analysis has proved useful for forensic identification especially in cases where nuclear DNA is not available, such as with hair evidence. Heteroplasmy, the presence of more than one type of mtDNA in one individual, is a common situation often reported in the first and second mtDNA hypervariable regions (HV1/HV2), particularly in hair samples. However, there is no data about heteroplasmy frequency in the third mtDNA hypervariable region (HV3). To investigate possible heteroplasmy hotspots, HV3 from hair and blood samples of 100 individuals were sequenced and compared. No point heteroplasmy was observed, but length heteroplasmy was, both in C‐stretch and CA repeat. To observe which CA “alleles” were present in each tissue, PCR products were cloned and re‐sequenced. However, no variation among CA alleles was observed. Regarding forensic practice, we conclude that point heteroplasmy in HV3 is not as frequent as in the HV1/HV2.     

Sickle Cell Trait Mimicking Multiple Inflicted Injuries in a 5-Year-Old Boy

Abstract:  Sickle cell disease (SCD) and sickle cell trait (SCT) can be associated with sudden unexpected death in the pediatric population, usually due to pulmonary complications occurring within the acute chest syndrome (ACS). Musculoskeletal complications can occur and are classically limited to bone infarcts. The occurrence of bone pathology centered upon the epiphyseal growth plate in SCD/SCT is extremely rare, and multiple such injuries in a single patient have not been previously reported. Herein, we describe a case of sudden unexpected death in a 5-year-old child with undiagnosed SCT due to the ACS, with widespread epiphyseal and periosteal bone lesions mimicking multiple inflicted injuries at autopsy. This case highlights the importance of clinicopathological correlation and is the first to describe SCT pathology as a mimic of nonaccidental injury.     

中国汉族人群41个STR基因座突变情况的观察分析

目的调查41个STR基因座在中国汉族人群中的突变情况。方法收集1 932个三联体家系4 546份血样本,采用AGCU_21+1、AGCU_EX22、Global Filer_Express~(TM)系统扩增41个STR基因座分型,统计各基因座发生突变的频率。结果 150个三联体在32个基因座共观察到154次突变,平均突变率为1.0×10~(-3)(95%CI:0.8~1.1×10~(-3)),突变率最高的是基因座SE33。其中一步突变152次(98.7%),两步突变2次(1.3%);146个三联体仅1个基因座发生突变(97.3%),4个三联体在2个基因座发生突变(2.7%);父、母来源突变比率约为4.7:1。结论 STR基因座等位基因突变现象较为常见,亲子鉴定时应引起注意。     

Latent fingermark development on a range of porous substrates using ninhydrin analogs--a comparison with ninhydrin and 1,8-diazofluoren

Three relatively new reagents for developing latent fingermarks on porous substrates, 1,2-indandione (IND), 5-methylthioninhydrin (5-MTN), and lawsone, are compared with the more widely used ninhydrin and 1,8-diazofluoren (DFO). Developed latent fingermark visualization on 10 different substrates comprising colored papers, cardboard, and cellophane rather than conventional printer and writing/notepad paper is assessed using latent fingermark deposits from 48 donors. Results show improved fluorescent fingermark visualization using IND compared with DFO on a range of colored cardboards and thick white paper, thus extending the range of substrates known to yield improved visualization with IND. Adding zinc chloride to IND failed to yield any further improvement in fluorescent fingermark visualization. 5-MTN (with and without zinc chloride posttreatment) showed no improvement in visualization compared with ninhydrin and DFO although visible fingermarks were developed. Lawsone produced fluorescent visible fingermarks only with white substrates, which were inferior to those produced with DFO.     

Isolation and Identification of Three By‐products Found in Methylamphetamine Synthesized by the Emde Route

This article describes the isolation and structural elucidation of three compounds produced during the synthesis of methylamphetamine by the so‐called “Emde” procedure. The “Emde” procedure involves the preparation of the intermediate chloropseudoephedrine or chloroephedrine from ephedrine or pseudoephedrine, respectively. The intermediates are then reduced to methylamphetamine with hydrogen under pressure in the presence of a catalyst. The by‐product compounds were isolated from methylamphetamine by column chromatography and liquid chromatography (LC). Proton nuclear magnetic resonance spectroscopy (¹H NMR), carbon nuclear magnetic resonance spectroscopy (¹³C NMR), and nanospray quadrupole‐time of flight‐mass spectrometry (Q‐TOF‐MS) were used to identify them as two stereoisomers of the compound N, N′‐dimethyl‐3,4‐diphenylhexane‐2,5‐diamine and N‐methyl‐1‐{4‐[2‐(methylamino)propyl]phenyl}‐1‐phenylpropan‐2‐amine.     

Thin layer chromatography/fluorescence detection of 3,4-methylenedioxy-methamphetamine and related compounds

A rapid and sensitive method for the detection of six methylenedioxylatedphenethylamines, 3,4-methylenedioxymethamphetamine (MDMA); 3,4-methylenedioxyamphetamine; 3,4-methylenedioxyethylamphetamine; N-methyl-1-(3,4-methylenedioxyphenyl)-2-butamine; N-methyl-1-(3,4-methylenedioxyphenyl)-3-butamine; and 3,4-methylenedioxydimethylamphetamine, by thin-layer chromatography with fluorescence detection is proposed. These compounds form fluorophores on the developing plate following spraying with a reagent consisting of sodium hypochlorite, potassium hexacyanoferrate (III), and sodium hydroxide, and heating for 3 min at 100 degrees C. Blue fluorescent spots were observed under ultraviolet light in a wavelength range of 250-400 nm. The detection limits for MDMA and the above related compounds were 50 ng. The proposed method was effectively applied to the detection of MDMA in urine samples.     

Gunshot residues on dry bone after decomposition-a pilot study

Abstract: Very little literature exists concerning radiochemical and microscopic analyses of gunshot wounds in decomposed material, and even less concerning skeletonized samples; the most advanced technologies may provide useful indications for the diagnosis of suspect lesions, especially if gunshot wounds are no longer recognizable. However, we know very little of the survival of gunshot residues (GSR) in skeletonized samples. This study examined nine gunshot wounds produced on pig heads which then underwent skeletonization for 4 years, and four gunshot entries on human heads from judicial cases which were then macerated to the bone in water; the samples underwent scanning electron microscopy coupled with energy dispersive X‐ray (SEM‐EDX) analysis. Positive results for GSR were observed only in four of the nine animal samples and in all four human samples. Among the human samples, two lesions showed Pb and Sb, one lesion only Pb, and one Pb, Sb, and Ba. This pilot study showed the survival of GSR in skeletal material and therefore the crucial importance of SEM‐EDX analyses on skeletonized material. Further studies are needed in order to ascertain the role of environmental modifications of GSR.     

HLA-DRB1基因分型芯片的法医物证学应用价值研究

目的对HLA-DRB1基因分型芯片在个体识别中的应用价值进行研究。方法根据HLA-DRB1基因座不同等位基因的独特序列设计探针,制成分型芯片。将待测样品DNA用末端标记了CY5的引物进行PCR扩增,产物与芯片进行杂交,根据杂交产生的荧光信号值确定样品在HLA-DRB1位点的基因型。将这一方法应用于561份样本的HLA-DRB1基因分型,根据基因型分布统计分析其法医学应用价值。同时,进行了家系调查和方法灵敏度分析,并应用于部分案例。结果利用微量检材,HLA-DRB1基因芯片可检测DRB1位点等位基因26个,基因型的分布符合Hardy-Weinberg平衡定律,该位点的观察杂合度(Ho)为0.888,期望杂合度(He)为0.902,多态信息含量(PIC)为0.893,平均非父排除率(PE)为0.801。家系调查和案例运用的结果表明,HLA-DRB1位点等位基因由亲代向子代的传递符合孟德尔遗传定律。结论HLA-DRB1为高度多态位点,其基因分型芯片可在亲子鉴定和个体识别中发挥重要作用。