The Ratio of 6β‐Hydroxycortisol to Cortisol in Urine as a Measure of Cytochrome P450 3A Activity in Postmortem Cases

Poisoning can occur with chronic accumulation of a drug due to reduced metabolic capacity; conversely, under‐treatment may occur due to an increased metabolic rate. Over half of all drugs are metabolized by the cytochrome P450 3A complex (CYP3A). The activity of CYP3A can be assessed by the urinary ratio of 6β‐hydroxycortisol to cortisol. The aim of this study was to determine the usefulness of this ratio as a postmortem marker for determining whether altered CYP3A enzyme activity occurred prior to death. In a series of 244 postmortem cases, this ratio ranged from 0.014 to 78.6 (median 3.50). The median was significantly higher (5.14) in a subgroup of 28 cases that exhibited the presence of CYP3A‐inducing drugs. In cirrhosis, the median ratio was 1.69. This pointed to a reduced metabolic capacity of CYP3A. Thus, the ratio may constitute a rough indicator of the CYP3A metabolic capacity, which could be of value in special cases.     

利用放射性核素骨显像检查鉴别鼻部骨折新旧程度回顾性法医学分析

目的 利用放射性核素骨显像检查鉴别鼻部骨折的新旧程度.方法 对48例疑似陈旧性鼻部骨折伤者放射性核素全身骨显像、局部断层骨显像及CT融合图像在鼻部骨折处放射性分布、浓聚情况的分析,鉴别鼻部骨折的新旧程度.结果 48例中8例放射性核素全身骨显像、局部断层骨显像及CT融合图像在鼻部骨折处显示放射性分布增高、浓聚区,诊为新鲜骨折,评定为轻伤;40例在鼻部骨折处未见明显异常放射性分布增高、浓聚区,诊为陈旧骨折,与本次外伤无因果关系.结论 放射性核素骨显像检查在鉴别鼻部骨折新旧程度方面可得到满意结果.     

磁珠法对混合斑中精子DNA批量自动提取的应用研究

目的 建立混合斑中精子DNA批量自动提取的方法.方法 对56例混合斑经第一步消化后的精子沉淀用DNA IQ试剂盒和Biomek（R）2000全自动核酸工作站自动提取纯化,3130xl型遗传分析仪分析结果.结果 56例混合斑检材均得到较好的STR分型结果.结论 DNA IQ试剂盒和Biomek（R）2000全自动核酸工作站批量自动提取纯化混合斑的方法快速简便,可应用于法庭科学实践.     

尸体血管造影技术的发展和趋势

尸体血管造影技术是一种有效的血管检查手段,对探查尸体血管,尤其是心脏、脑部血管的情况具有重要意义。该技术起源于15世纪,发展于18、19世纪。尤其是在发现X线之后,该技术进入了快速发展阶段,无论是在对比剂、灌注方法,还是在成像方法上都取得了巨大的发展。目前,该技术已被广泛应用于实践中。但该技术仍存在一些瑕疵,首先,对比剂仍无法克服渗透弥散、栓塞血管等问题,最理想的对比剂仍未发现;其次,目前的灌注方法仍无法模拟生理血液流动状态。在＂保全尸＂的宗教和传统观念的指引下,有必要进一步提高目前的造影技术,以满足实践需求。     

A Comparison Between Digital Radiography,Computed Tomography,and Magnetic Resonance in the Detection of Gunshot Residues in Burnt Tissues and Bone

The radiological search for GSR is crucial in burnt material although it has been rarely tested. In this study, thirty‐one bovine ribs were shot at near‐contact range and burnt to calcination in an oven simulating a real combustion. Computed tomography (CT) and magnetic resonance (MR) were performed before and after carbonization and compared with former analyses with DR (digital radiography); thus comparing the assistance, the radiological methods can provide in the search for GSR in fresh and burnt bone. DR demonstrated the greatest ability in the detection of metallic residues, CT showed lower abilities, while MR showed a high sensitivity only in soft tissues. Thus, DR can be considered as the most sensitive method in the detection of GSR in charred bones, whereas CT and MR demonstrated much less reliability. Nonetheless, the MR ameliorates the analysis of gunshot wounds in other types of remains with large quantities of soft tissues.     

Determination of Acetamiprid and IM‐1‐2 in PostMortem Human Blood,Liver, Stomach Contents by HPLC‐DAD

An HPLC‐DAD method was developed to detect and quantify a neonicotinoid insecticide acetamiprid (ATP) and its metabolite IM‐1‐2 in autopsy samples of a fatal intoxication case. The postmortem blood and tissue distribution of ATP and IM‐1‐2 was determined for the first time. The method showed acceptable precisions and recoveries with relative standard deviations of <10% for ATP level and 1.38 % for IM‐1‐2. The detection and quantification limits for ATP were 0.015 μg/mL and 0.030 μg/mL for blood and were 0.035 μg/g and 0.050 μg/g for liver samples, respectively. The mean contents of ATP were 0.79 μg/g in the liver, 47.35 μg/g in the stomach contents and 2.7 μg/mL in the blood. IM‐1‐2 content was 17.0 μg/g in the stomach contents. ATP and IM‐1‐2 were not detected in the urine. The presence of ATP and IM‐1‐2 in the samples was confirmed by GC‐MS. The method can be exploited in future forensic casework.     

Influence of Paraquat on Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae) Infesting Minced‐beef Substrates in Kelantan,Malaysia

This study investigated the influence of paraquat, a prevalent poison used by suicides, on initial oviposition and development of Chrysomya megacephala (Fabricius) using minced‐beef substrates. Paraquat in lethal dose for human (40 mg/kg), two times the lethal dose (80 mg/kg) and five times the lethal dose (200 mg/kg) were mixed thoroughly with respective minced‐beef substrates (1 kg each) that were decomposed in a shaded habitat fully protected from rain. Results of four replications of the above experiment revealed that the presence of paraquat neither delayed initial oviposition nor prolonged the developmental stages of C. megacephala. Therefore, estimation of postmortem interval (PMI) based on empirical baseline data obtained using animal models devoid of any poisons would still be appropriate for estimating PMI in paraquat‐related deaths.     

双手第1骨间背侧肌代谢物的氢质子磁共振波谱

目的 探讨氢质子磁共振波谱（1H-magnetic resonance spectroscopy,1H-MRS）检测技术在尺神经损伤预后评估的应用前景.方法 对12例健康青年志愿者、1例尺神经完全损伤者双手第1骨间背侧肌的代谢物进行1H-MRS检测,对采集到的数据进行统计分析. 结果 健康女性成年人第1骨间背侧肌的细胞外脂质（extra-myocellular lipids,EMCL）峰下面积高于男性（P＜0.05）,胆碱、肌酸、细胞内脂质（intra-myocellular lipids,IMCL）在两性间差异均无统计学意义（P＞0.05）,双手间各峰下面积差异均无统计学意义（P＞0.05）.尺神经损伤者患侧EMCL峰较健侧偏高,且FDI面积缩小.结论 1H-MRS对肌肉代谢物的无创性以及定量检测对周围神经损伤的预后评估具有一定价值.     

Do bone elasticity and postmortem interval affect forensic fractographic analyses?

Forensic fractographic features of bone reliably establish crack propagation in perimortem injuries. We investigated if similar fracture surface features characterize postmortem fractures. Experimentally induced peri- and postmortem fractures were used to assess if fractographic features vary as bone elasticity decreases during the postmortem interval (PMI). Thirty-seven unembalmed, defleshed human femoral shafts from males and females aged 33–81 years were fractured at varying PMIs with a drop test frame using a three-point bending setup and recorded with a high-speed camera. Vital statistics, cause of death, PMI length, temperature, humidity, collagen percentage, water loss, fracture energy, and fractography scores were recorded for each sample. Results showed that fractographic features associated with perimortem fractures were expressed in PMIs up to 40,600 accumulated degree hours (ADH), or 60 warm weather days. Hackle was the most consistently expressed feature, occurring in all fractures regardless of ADH. The most variable characteristics were wake features (78.4%) and arrest ridges (70.3%). Collagen percentage did not correlate strongly with ADH (r = −0.04, p = 0.81); however, there was a strong significant correlation between ADH and water loss (r = 0.74, p < 0.001). Multinomial logistic regression showed no association between fractographic feature expression and ADH or collagen percentage. In conclusion, forensic fractographic features reliably determine initiation and directionality of crack propagation in experimentally induced PMIs up to 40,600 ADH, demonstrating the utility of this method into the recent postmortem interval. This expression of reliable fractographic features throughout the early PMI intimates these characteristics may not be useful standalone features for discerning peri- versus postmortem fractures.