2种陈旧骨骼、牙齿DNA纯化方法的比较

目的比较有机法+QIAquick纯化法和DNA IQ磁珠法对陈旧骨骼和牙齿DNA的纯化效果。方法选择10份陈旧骨骼和12份牙齿样本,进行消化后分别采用有机法+QIAquick纯化法和DNA IQ磁珠法进行提取纯化,进行DNA定量后用SinofilerTM试剂盒进行检测。结果 2种方法纯化的骨骼、牙齿DNA的IPC CT值无显著差异。有机法+QIAquick纯化法纯化的骨骼、牙齿DNA平均浓度分别为0.180ng/μL±0.068ng/μL和0.132ng/μL±0.027ng/μL,所有样品均获得全部基因分型。DNA IQ磁珠法纯化的DNA平均浓度分别为0.038ng/μL±0.028ng/μL和0.036ng/μL±0.007ng/μL,有5份骨骼和6份牙齿样本仅获得部分基因分型或未能分型。结论有机法+QIAquick纯化法对陈旧骨骼、牙齿DNA的纯化效果优于DNA IQ磁珠法。     

An Analysis of Systematic Elemental Changes in Decomposing Bone

The aim of this pilot study was to investigate compositional changes in bone during decomposition. Elemental concentrations of barium, calcium, iron, potassium, magnesium, zinc and phosphorus in porcine bone (as an experimental analog for human bone) were analyzed by inductively coupled plasma optical emission spectroscopy (ICP‐OES). The samples were taken from porcine bone subjected to shallow burial and surface depositions at 28‐day intervals for a period of 140 days. Results indicated that ICP‐OES elemental profiling has potential to be developed as a forensic test for determining whether a bone sample originates from the early stages of soft tissue putrefaction. Significant changes in iron, sodium and potassium concentrations were found over 140 days. These elements are known to be primarily associated with proteins and/or tissue fluids within the bone. Changes in their respective concentrations may therefore be linked to dehydration over time and in turn may be indicative of time since deposition.     

A Simple and Efficient Method of Extracting DNA from Aged Bones and Teeth

DNA is often difficult to extract from old bones and teeth due to low levels of DNA and high levels of degradation. This study established a simple yet efficient method for extracting DNA from 20 aged bones and teeth (approximately 60 years old). Based on the concentration and STR typing results, the new method of DNA extraction (OM) developed in this study was compared with the PrepFiler? BTA Forensic DNA Extraction Kit (BM). The total amount of DNA extracted using the OM method was not significantly different from that extracted using the commercial kit (p > 0.05). However, the number of STR loci detected was significantly higher in the samples processed using the OM method than using the BM method (p < 0.05). This study aimed to establish a DNA extraction method for aged bones and teeth to improve the detection rate of STR typing and reduce costs compared to the BM technique.     

Use of a Gelatin‐based Consolidant to Preserve Thermally‐Altered Skeletal Remains,

Thermally altered skeletal remains can be very fragile and fragmented and are typically further fragmented or even destroyed when handled; recovery of such remains from a scene can therefore be extremely challenging. There are few recommendations and no generally accepted practices for preserving burned bone for recovery and transport. Here, we test whether the application of a gelatin‐based consolidant at the scene can preserve thermally altered bone in the condition and relative anatomical position in which it was discovered. A solution of Knox^® brand gelatin and water was applied to burned pig mandibles using a spray bottle. Qualitative and quantitative analysis indicates that the application of the consolidant significantly decreased fragmentation as compared to untreated controls (p < 0.05), with most of the treated mandibles remaining completely intact after recovery and transport to a secondary location. In addition to the effectiveness for preservation, the method is also easy to apply, inexpensive, and reversible.     

Differences among species in compact bone tissue microstructure of mammalian skeleton: use of a discriminant function analysis for species identification

In order to develop an identification key for distinguishing between several mammalian species, bone structure of their compact bone tissue was analyzed using qualitative and quantitative characteristics. Ninety femora of adult male humans, pigs, cows, sheep, rabbits, and rats were studied. The average area, perimeter, minimum, and maximum diameter of 1863 Haversian canals and 1863 secondary osteons were measured using a digital image device. The observed data were first used to evaluate inter- and intraspecies diversity. After that, we applied a discriminant function analysis for differentiation of the species by these variables. Classification functions for investigated species give cross-validated correct classification rates for 76.17% of cases. This percentage value can be increased by integrating conclusions from the qualitative analysis.     

DNA降解与腐败尸体死亡时间的相关性

目的探讨骨髓细胞核DNA含量变化与腐败尸体死亡时间的关系。方法应用DNA高度特异性染色方法Feulgen改良法结合计算机图像分析技术对死后不同时间(0～14d)胸骨骨髓细胞核DNA含量变化进行分析。结果胸骨骨髓细胞核DNA含量随死亡时间延长呈缓慢而规律下降,直至死后两周仍未完全降解。结论死后DNA降解速率与死亡时间呈线性关系,测定死后骨髓细胞核DNA含量可望成为腐败尸体死亡时间推断的新方法。     

男性耻骨结构软X线影像与年龄关系的研究

根据118付10～60岁男性耻骨样本的软X线片形态，设计了新的数量化赋值指标标准。用数量化理论Ⅰ和逐步回归数学模型对所得数据进行统计分析，借用电子计算机技术，建立两个推断男性耻骨年龄方程。其方程检验：复相关系数（R）分别为对0．9843和0．9818；标准差（S）分别为：2．52和2．54；两个方程均F＞F0.001；P＞0．01。按新的指标标准赋值，经4个省市提供的58例（其中3例为实际应用案例）未用过的男性耻骨拍摄的软X线影像照片测试；±S8296％，±2S96．56％，其结果达到设计要求。该方程可用来推断男性耻骨年龄。     

钝器致鼻部骨折95例法医学分析

目的探讨钝器致鼻部骨折种类、骨折及其修复的X线与CT表现差异等特点,为鉴定实践提供参考。方法对福建省古田县1999年1月至2013年12月发生的95例成年人因钝器致鼻部骨折的实际案例,按基本情况、骨折部位、致伤方式、确诊方式、鉴定意见等信息进行描述性统计,并对不同损伤根据新旧标准得出的鉴定意见进行比对。结果 95例成年人中,男性87例,女性8例,骨折部位、数量与鼻骨解剖关系、受力大小和方向均有明显的关联,复合性骨折多见,X线检查无法确定的骨折,经CT检查均可明确诊断。不同骨折类型按新旧标准鉴定意见有所不同。结论鼻部骨折数存在性别差异,外力大时易出现复合性骨折,CT检查明显优于X线检查。     

耻骨推断年龄方程改进

为了进一步提高耻骨推断年龄方程推广使用价值,在原方程454副样本基础上又增加146副,共600副（男、女各300副）。观测项目（形态特征）由男女各9个减为各8个。有效赋分标准,男性增加5个;女性增加4个。每项中0改为1。使用数量化理论1和逐步回归数学模型,取得8个方程、6个推断年龄表。应用时可根据不同性别、不同年龄组,选用不同推断年龄表,使用不同标准差。比原方程,提高了实际应用价值。     

Detection of methamphetamine in mouse femurs exposed to high temperature

Bone samples are valuable for examining the cause of death and circumstance leading up to death when body fluids are not available for forensic toxicological analysis. Examined were heat-induced changes in methamphetamine and amphetamine concentrations in femurs removed from methamphetamine-injected mice to determine if the burned bones could be used for toxicology testing. The femurs were heated at 100°C, 300°C, or 500°C for 10 or 30 min. The tissue structure of the heated femurs was preserved at 100°C for 30 min but was destructed at higher temperatures. Methamphetamine and amphetamine were detected in femurs heated at 100°C for 10 min, 100°C for 30 min, and 300°C for 10 min (with methamphetamine and amphetamine concentrations ranging from 0.36 to 35 μg/g and 0.54 to 47 μg/g, respectively). Methamphetamine and amphetamine were detectable when heated above their decomposition temperature as a result of limited heat transfer do to protection provide by the femoral muscle. Thus, the bone could be a useful analytical sample in cases of burn-related deaths, where it is difficult to collect body fluids.