A Unique Type of Birth Trauma Mistaken for Abuse

Pediatric abusive head trauma is a challenging subject across many disciplines. Of particular importance is the identification of mimics of abuse, so cause and manner of death can be properly assigned. We present the case of suspected child abuse involving an infant who presented unresponsive to the hospital with hypoglycemia, hypothermia, and bilateral parietal fractures. An autopsy revealed fractures associated with organizing scalp hemorrhage and gross leptomeningeal congestion and hemorrhage. The fractures were circular with external displacement, rounded margins, and subperiosteal new bone formation indicative of healing. Birth records revealed vacuum assist and cesarean section delivery. Although vacuum extraction‐related injuries are typically cephalohematomas and/or linear fractures, the outbending and circular morphology of the fractures are consistent with vacuum extraction. Moreover, microscopic neuropathological examination revealed hemorrhagic purulent leptomeningitis. This unique case demonstrates the importance of considering birth trauma in the determination of cause and manner of death of an infant.     

潞党参多糖的提取及含量测定

目的：从潞党参中提取多糖并测定多糖含量。方法：用水提醇沉法提取潞党参多糖;用苯酚．硫酸法测定其含量。结果：测得潞党参中多糖含量为20．99％,平均收回率为99．03％,RSD=1．01％(n=3)。结论：潞党参中多糖含量较高,具有开发利用价值。     

陈旧骨骼及牙齿的性别检验

为分析陈旧骨骼及牙齿的性别，建立了从陈旧人骨骼和牙齿中提出DNA的方法。通过PCR技术扩增，得到X－Y染色体上的单拷贝同源基因片断（AmelogeninGene）。结果显示，从死亡后2年、4年、7年和10年的4个骨骼和牙齿样品中，均成功地获得了特异的PCR扩增片段。女性为单一的106bp条带，男性为106bp和112bp两条谱带。其快速、简单、可靠，为陈旧骨骼和牙齿的性别鉴定提供了方法。     

Determination of blood-harbored 2′-diclazepam with auto-spe and gc-ms/ms

Objective To develop a GC-MS/MS method for determination of 2′-diclazepam in blood. Methods The sampling blood was extracted via HLB cartridge (a product from Waters Corporation, enabling operation of the auto-SPE (solid-phase extraction) for this determination) that was eluted with ethyl acetate, having the collected eluate subjected to GC MS/MS analysis. Results For the 2′-diclazepam tested, a linear relationship was present between the concentration and peak area from the calibration curve in the range of 20 ～ 20μg/mL, demonstrating the limit of detection (LOD) being 10ng/mL. Moreover, the average recoveries were shown within the range of 81.8%~90.4%, and the relative standard deviations among 4.89%~5.47%. Conclusion The here-established method is of high sensitivity, selectivity and strong operability, suitable for determination of diclazepam in blood. © 2021, Editorial Office of Forensic Science and Technology. All rights reserved.     

Less is More—Optimization of DNA Extraction from Canine Feces

Although most DNA crime laboratories may not encounter fecal samples often, they are a familiar sample type in non‐human forensic laboratories due to their prevalence in the environment. Fecal matter can be challenging due to low numbers of nucleated cells and the presence of inhibitors that impede amplification success. Sampling location (internal vs. external), sampling quantity (10–200 mg), and various extraction protocols (silica matrix, bead beating, and clean‐up column) were evaluated to maximize DNA yield. The greatest yield of intact DNA was obtained using a modified silica matrix extraction protocol (VGL‐Fecal) on 30–50 mg of fecal matter collected from the external surface of a stool that had been dried for 24 h. This optimized sampling and extraction protocol was applied to a pilot study where DNA yield and genotyping success were evaluated. By optimizing our collection, sampling, and extraction procedures, a reliable method for maximizing the yield of canine fecal DNA was developed.     

法医学DNA提取试剂盒优化及适用性评价

目的用磁性纳米磁珠和自主设计的试剂体系及提取流程,来建立一种基因组DNA的快速提取优化方案。方法利用自主研制的法医DNA提取纯化试剂盒设计实验方案对陈旧棉签血样进行DNA提取,用紫外分光光度计分析定量,通过对实验结果进行分析比较进一步优化自主研发的法医学DNA提取试剂盒。用优化之后的试剂盒提取各种不同的疑难捡材,探索本试剂盒的适用性。结果通过优化试验条件,同样获得了各种检材理想的DNA提取效果,却大大降低了DNA样本的提取成本。结论经优化过的国产磁珠DNA提取试剂盒完全可以应用与法医DNA检测中。     

ASE-GPC/GC/MS方法检验血中20种常见毒物

目的建立血样中20种常见毒物的ASE-GPC/GC/MS检验方法。方法血样采用快速溶剂萃取,GPC/GC/MS检验。结果 20种常见毒物平均回收率为85.3%~99.1%,检出限为0.02μg/mL~0.03μg/mL。结论该方法可满足实际检案的需求。     

LC-MS/MS同时分析尿液中15种安眠镇静药物及其代谢物

目的建立尿液中15种常见安眠镇静药物及代谢物的液相色谱-串联质谱分析方法。方法尿液经酶水解、固相萃取后,用C18液相柱分离,以含甲酸铵和甲酸的水、乙腈为流动相梯度洗脱,质谱采用电喷雾电离（ESI）-正负离子模式同时扫描,采用二级质谱多反应监测（MRM）模式检测目标化合物。结果以化合物的保留时间、两对母离子/子离子对定性,尿中常见安眠镇静药物的检测限为0.01～0.5ng/mL（ESI＋）和10ng/mL（ESI-）;相关系数r在0.994以上;日内及日间精密度均在18%以下;绝对回收率在64.80%～116.20%之间。结论方法快速、灵敏、简便、可靠,能同时分析尿液中的15种安眠镇静药物及其代谢物。     

Automated extraction of DNA from reference samples from various types of biological materials on the Qiagen BioRobot EZ1 Workstation

We have validated and implemented a protocol for DNA extraction from various types of biological materials using a Qiagen BioRobot EZ1 Workstation. The sample materials included whole blood, blood from deceased, buccal cells on Omni swabs and FTA Cards, blood on FTA Cards and cotton swabs, and muscle biopsies. The DNA extraction was validated according to EN/ISO 17025 for the STR kits AmpF?STR^® Identifiler^® and AmpF?STR^® Yfiler^® (Applied Biosystems). Of 298 samples extracted, 11 (4%) did not yield acceptable results. In conclusion, we have demonstrated that extraction of DNA from various types of biological material can be performed quickly and without the use of hazardous chemicals, and that the DNA may be successfully STR typed according to the requirements of forensic genetic investigations accredited according to EN/ISO 17025.     

Genetic identification of degraded DNA samples buried in different types of soil

Biological samples buried in different types of soil are often found in crime scenes. These samples are usually highly degraded which difficult their analysis. Several factors contribute to the degradation of biological material including temperature variation, humidity, UV light and especially the presence of microorganisms.Blood was collected from three non-related male donors and blood stains were made in fabrics such as jeans, cotton and lycra. Blood stains were dried at room temperature and buried in three different types of soil (sand, marsh and clay), to promote its natural degradation.The buried samples suffered a high degradation over time which difficult their genetic identification. The marshy soil proved to be the most destructive one, leading to rapid degradation of the different analyzed fabrics, which disabled the obtainment of the genetic profiles.