理化因素对毛发形态结构的影响

毛发是法医学研究的主要对象之一。在许多命案的勘验工作中,经常看到各类理化因素作用于人体造成毛发形态结构的损伤变化,因此,毛发损伤的检验在刑事办案活动中具有重要的意义。有关毛发损伤检验的问题,法医学文献已有论述。我们感到,文献中有关毛发损伤检验的知识难以满     

人发中35种元素的堆中子活化法（NAA）

毛发是人体代谢终端之一，它具有摄取、积累，排泄各种元素的机能，毛发中所含的各种元素量，远远超过血、尿中所含的浓度，毛发跟其它提供化验用的检材不同，可长期保存而不丧失其原有特性。本世纪六十年代以后，毛发的研究在国际上引起广泛的兴趣和极大的重视，但人发分析最早受到注意是它在法医学上的应用。     

利用聚乙烯（PE）薄膜提取毛发

随着我国法制的逐渐完善，人们的法律意识普遍增强，同时由于各种因素的影响，犯罪分子的反侦查意识也逐渐增强，此时DNA微量鉴定技术更加显出其不可替代的“杀手锏”作用。正常情况下，由于新陈代谢作用，人体平均每小时至少脱落3根毛发，毛发的脱落很难避免，因此，现场毛发的提取显得更加重要。常用提取毛发的方法无外乎利用放大镜直接观察、打光观察及喷水等方法提取。     

药物滥用者毛发药物分析研究进展

对药物滥用者的检测，7O年代前一般采用血液及尿液分析。1978年，Baumgartner等有次采用RIA技术，成功地对人体毛发检材中海洛因／吗啡进行了检测．获得满意的结果。自此用于生物体液分析的各种免疫学，物理化学技术包括RIA、GC／MS．MS／ms和HPLC逐渐移用于毛发中药物分析。近年来，毛发药物分析成了法科学和临床分析毒物学研究的热点。众多的研究表明，毛发分析和尿液分析两者具有互补的优点。尿液分析能提供个体短期使用药物的信息，而长期使用药物，从数月到数年，通过毛发分析较易得到证实。毛发分析不仅提供个体使用药物种类…     

毛发作证

在案发现场,办案人员不会放过任何可疑的蛛丝马迹,包括一些不起眼的痕量证据,比如毛发。细细的毛发中含有从人体血液循环系统中吸收来的大量化学物质,是很好的法医鉴定对象,在案件侦破中有着重要的价值。体毛的结构和特征要了解法医如何从细细的毛发中寻找到有用的破案线索,则首先需要了解体毛的基本结构。体毛是分布在人体表面的毛发的总称。     

几种灵长类毛发角蛋白组分的分析研究

迄今为止,对人和各种动物毛发的研究报道已有不少,诸如:光学显微镜观察毛发的形态结构,毛发微量元素的分析,扫描电镜对毛发进行种属鉴别,以及用 SDS—PAGE 分析毛发角旦白组分的研究,但是,对于灵长类毛发的比较研究则很少见,曹汉民等利用扫描和透射电镜对灵长类毛发的亚显微给构进行比较研究,     

人发中35种元素的堆中子活化法(NAA)同时测定

毛发是人体代谢终端之一,它具有摄取、积累、排泄各种元素的机能,毛发中所含的各种元素量,远远超过血、尿中所含的浓度,毛发跟其它提供化验用的检材不同,可长期保存而不丧失其原有特性.本世纪六十年代以后,毛发的研究在国际上引起广泛的兴趣和极大的重视,但人发分析最     

刃尖部有小豁的成伤特点

<正> 刃尖部有小豁的刺器形成刺创的特点是,创缘有皮肤小舌或在实质脏器创壁中有纵行挫伤带形成,其位置形态与小豁在刀尖上的位置与大小有关。当刀刺入人体,刀上的小豁挤压皮肤或脏器,就可能形成皮肤小舌或脏器的纵行挫伤带。此类损伤对致伤工具特征的认定在法医检验中具有重要的意义。现结合案例进行探讨。     

毛发枪弹损伤的环境扫描电镜研究

目的探讨毛发枪弹损伤微观形态与射击距离之间的关系。方法应用环境扫描电镜/能谱仪对64式手枪在0~200cm范围内射击造成的毛发损伤及附着物进行形态和成分分析。结果0~30cm射击,毛发表面粘附有大量密集分布的球形射击残留物颗粒,鳞片有严重斑纹状损伤和崩裂缺损;30~60cm射击,毛发表面粘附有较多散在分布的球形射击残留物颗粒,鳞片有轻微斑纹状损伤和崩裂缺损;100cm距离射击,毛发表面粘附有少数个别射击残留物颗粒,鳞片无斑纹状损伤;200cm距离射击,毛发表面无射击残留物。毛发枪弹射击断裂形态差异较大,大体分为剪切断裂和牵拉断裂两种类型,与射击距离无明显相关性。结论毛发表面粘附的大量球形射击残留物颗粒及其造成的鳞片斑纹状损伤对于法医学鉴定贴近距离射击((30cm)具有重要的实用价值。     

人体面部形态特征的研究进展

而部形态特征研究在很多学科中都具有重要作用,例如雕塑学、考^学、医学美容、法医学颅骨面貌复原等。随着计算机技术的快速发展,使得面貌复原技术也大大提高,同时,对五官形态特衙的要求也相应提高。现就国内外在人体而部形态特征相关研究作一概述。     

A morphological study of human hair tips by scanning electronic microscope (SEM)

Morphological characteristics of human hair tip was studied by SEM. It was concluded that human hair tips could be classified into eight types. The tip formation, distribution and changes after being trimmed were explored. This study can be used in the mechanism research of human hair growth and the forensic hair examination.     

Detection of meperidine and its metabolites in the hair of meperidine addicts

The presence of meperidine and its metabolites in the hair of meperidine addicts was investigated using GC–MS (EI, PCI). Meperidine and its three metabolites – normeperidine, N-methoxy meperidine and acetyl normeperidine, were found in hair samples from addicted subjects. Methods for the simultaneous determination of meperidine and its metabolites by GC–MS-SIM were also established for human hair samples. After the addition of d₄-meperidine as an internal standard, hair samples weighing 5 mg were incubated in 0.1 M HCl at 45°C overnight, and the resulting digests were extracted with ether. The recoveries were greater than 80%, with coefficients of variation (CVs) between 4.48 and 8.31%. The calibration curves for meperidine and normeperidine in hair were linear over a concentration range of 1 to 500 ng per mg of hair, with correlation coefficients of r=0.9990 and r=0.9992, respectively. Values less than 0.25 ng/mg of hair were cut off. Hair samples obtained from 60 drug addicts were analyzed using this method, and the content of meperidine and normeperidine was determined to be 103±130 and 117±143 ng/mg, respectively. Sectional analysis revealed that meperidine was present and stable in hair for at least 20 months, but normeperidine content at the level of the hair root was higher compared to the tip of the hair shaft. The results also revealed that there was a correlation between the subject’s drug abuse history and the distribution of drug along the hair shaft, and between the doses of meperidine and drug content presented in hair.     

度冷丁滥用者毛发分段分析及其结果评价

以度冷丁滥用者为研究对象,在度冷丁滥用者毛发中检出度冷丁及代谢物去甲度冷丁、N一羟甲基度冷丁和N-乙酰度冷丁。60例度冷丁滥用者头发中度冷丁和去甲度冷丁的含量分别为103±130ng／mg和117±143ng／mg。度冷丁稳定地存在于头发中,检出时限至少为药后20个月,而去甲度冷丁则随着离头发根距离的增加而降低。头发分段分析揭示度冷丁在毛干中的分布和滥用史、剂量和含量存在相关性。     

汉人不同区段头发的线粒体HVII异质性的序列分析

目的探讨汉族人不同区段头发线粒体DNA(mtDNA)HVII区的异质性。方法用5%Chelex100法提取7名汉族个体额、顶、枕及左、右颞部等5个不同部位的不同根不同段的头发mtDNA,同时取各自毛囊作为对照;以两步法扩增纯化后测序反应,3100型遗传分析仪检测。结果不同毛干区段的点异质性多发生于女性长发远段、儿童及老年人,不同区及同一根不同段均可发生点异质性,可多达4处,点异质性可能相同,可能不同,但一般多发生于相同个体毛囊mtDNA点突变处。不同区头发长度异质性不同,同一根头发不同段长度异质性相同。mtDNA点异质性有一定遗传倾向。稀释及混合样本mtDNA图谱也可表现为“点异质性”图谱。结论根据人头发毛干mtDNA测序结果得出“排除”结论时一定应慎重。     

Degeneration of Nuclei and Mitochondria in Human Hairs

Abstract:  It is generally accepted that nuclei degrade in developing hair shafts but the point at which such occurs has not been investigated. The fate of mitochondria in the keratinizing hair shaft has been less clear. This study uses transmission electron microscopy to investigate when nuclei and mitochondria are no longer visible in the developing hair shaft. Serial sections were obtained from anagen head hairs absent follicles in order to determine the sequence of degradation of nuclei and mitochondria in the hair shaft by starting at the root bulb and proceeding toward the hair tip. It was demonstrated that nuclei and mitochondria become invisible in the keratinizing hair shaft at about the same time. This was found to occur fairly early in the process at the level of the hair shaft where the hair cuticle becomes permanent.     

The use of supercritical fluid extraction for the determination of amphetamines in hair

A laboratory study interested in the analysis of human hair for drugs-of-abuse was conducted to determine if drugs could be detected and quantified from hair. Supercritical fluid extraction (SFE) techniques followed by GC-MS analysis were applied to extract amphetamines from hair. The group of amphetamines included methylenedioxyamphetamine (MDA), methylenedioxymetamphetamine (MDMA), methylenedioxyethylamphetamine (MDEA) and internal standard mephentermine (MP). To validate information on amphetamine use in hair, powdered hair samples free from drugs were collected and soaked in a known amphetamine standard solution. Authentic fortified case hair samples taken from known drug users known to have consumed amphetamines were also analyzed for amphetamine. Results from this study show that amphetamine use can be detected in spiked and authentic fortified human hair using SFE techniques for qualitative and quantitative reproducible results.     

Human hair histogenesis for the mitochondrial DNA forensic scientist.

Analysis of mitochondrial DNA (mtDNA) sequence from human hairs has proven to be a valuable complement to traditional hair comparison microscopy in forensic cases when nuclear DNA typing is not possible. However, while much is known about the specialties of hair biology and mtDNA sequence analysis, there has been little correlation of individual information. Hair microscopy and hair embryogenesis are subjects that are sometimes unfamiliar to the forensic DNA scientist. The continual growth and replacement of human hairs involves complex cellular transformation and regeneration events. In turn, the analysis of mtDNA sequence data can involve complex questions of interpretation (e.g., heteroplasmy and the sequence variation it may cause within an individual, or between related individuals. In this paper we review the details of hair developmental histology, including the migration of mitochondria in the growing hair, and the related interpretation issues regarding the analysis of mtDNA data in hair. Macroscopic and microscopic hair specimen classifications are provided as a possible guide to help forensic scientists better associate mtDNA sequence heteroplasmy data with the physical characteristics of a hair. These same hair specimen classifications may also be useful when evaluating the relative success in sequencing different types and/or forms of human hairs. The ultimate goal of this review is to bring the hair microscopist and forensic DNA scientist closer together, as the use of mtDNA sequence analysis continues to expand.     

Short tandem repeat (STR) genotyping of keratinised hair. Part 1. Review of current status and knowledge gaps

We present a review of the literature on procedures for obtaining short tandem repeat (STR) genotypes from keratinised hair, being either hair shaft or telogen phase (naturally shed) hairs without associated scalp, follicle or sheath cells. Both the hair shaft and the telogen hair club have been subjected to the DNA-degrading keratinisation process and are more likely to be found at a crime scene than anagen (plucked) or catagen phase hairs. We discuss human hair structure, the human hair growth cycle, the keratinisation process and their implications for DNA extraction procedures, PCR amplification strategies and the interpretation of STR genotypes. Knowledge gaps and areas requiring research are identified and are the subject of a second article in this series.     

烫发、梳理和拉伸损伤对头发角蛋白的影响

目的为法医物证学中的头发个人识别提供依据。方法采用烫发、梳理、拉伸等方式对正常人头发进行损伤处理,用十二烷基磺酸钠-聚丙烯酰胺凝胶梯度电泳(SDS-PAGGE)和激光光密度扫描仪对损伤头发角蛋白进行分析。结果三种损伤条件均可导致头发损伤,造成分子量(MW)67000～43000区域头发角蛋白的丢失。结论头发角蛋白的丢失程度随着损伤程度增加而增加。     

Microscopical discrimination of twins' head hair

Twin populations are ideal for studying human variation; a study of twin's hair, therefore, provided a better understanding of the value of hair comparisons. Duplicate head hair samples from 17 pairs of twins and one set of identical triplets were compared in a verified blind study. In addition to the direct comparison of all twins, random samples of two or three hairs were compared with randomly selected groups of known samples in a second blind study, to better simulate an ordinary forensic science case. Features commonly used by forensic hair examiners were adequate to distinguish hair samples from each twin from all other samples, illustrating the power of microscopical comparison when numerous questioned hairs are available in evidence. When two or three hairs were compared with randomly selected known samples, several were indistinguishable from hair samples other than the true source, proving once again that a human hair can never be associated with one person to the exclusion of all others.