损伤皮肤中白三烯B_4含量测定与损伤时间推断

本文作者利用高压液相色谱,快速检测大鼠皮肤切创创缘组织中白三烯B_4含量。结果发现,生前各损伤时间组创缘中白三烯B_4含量明显升高,且在1小时内与损伤时间有一定线性关系;死后损伤标本未见白三烯B_4含量升高。由此表明白三烯B_4含量测定,对推断生前1小时内的损伤时间有重要价值。高压液相色谱能快速、准确地检测损伤组织中的白三烯B_4。     

PAP免疫组织化学技术检测血小板膜糖蛋白

<正> 血小板膜糖蛋白 GPⅠ_b 和 GPⅢa 在血小板粘附、聚集中起着极其重要的作用。为了直接检测组织中血小板粘附、聚集和血栓形成,我们建立了应用抗人血小板膜糖蛋白 GPⅠ_b和 GPⅢa 的单克隆抗体的 PAP 免疫组织化学技术,并首次对该技术在法医学中的应用进行了初步探讨。     

A novel histological technique for distinguishing between epithelial cells in forensic casework

There are a number of forensic cases in which the identification of the epithelial cell type from which DNA originated would provide important probative evidence. This study aimed to develop a technique using histological staining of fixed cells to distinguish between skin, buccal and vaginal epithelium. First, 11 different stains were screened on formalin-fixed, wax-embedded cells from five women. Samples were analysed qualitatively by examining staining patterns (colour) and morphology (absence or presence of nuclei). Three of the staining methods – Dane's, Csaba's and Ayoub-Shklar – were successful in distinguishing skin epithelial cells from buccal and vaginal. Second, cells were smeared directly onto slides, fixed with one of five fixatives and stained with one of the three stains mentioned above. Methanol fixation, coupled with the Dane's staining method, specific to keratin, was the only technique that distinguished between all three cell types. Skin cells stained magenta, red and orange and lacked nuclei; buccal cells stained predominantly orange–pink with red nuclei; while vaginal cells stained bright orange with orange nuclei and a blue extracellular hue. This staining pattern in vaginal cells was consistent in samples collected from 50 women aged between 18 and 67. Identification of cell type from unlabelled micrographs by 10 trained observers showed a mean success rate of 95%. The results of this study demonstrate that histological staining may provide forensic scientists with a technique for distinguishing between skin, buccal and vaginal epithelial cells and thus would enable more conclusive analyses when investigating sexual assault cases.     

大鼠皮肤挫伤修复过程中NF_κB P65表达的研究

目的探讨皮肤挫伤修复过程中,核转录因子(NFkB)P65在挫伤区不同时间表达的变化规律。方法 应用免疫组化技术对挫伤后0h、3h、6h、9h、12h、1d、3d、5d、7d、10d的大鼠皮肤挫伤组织中NFkB P65的表达进行研究。结果伤后3h,挫伤区内浸润的少量多核粒细胞的胞质中NFkB P65呈弱阳性表达,阳性率为(3.20％±0.15％);伤后6h,阳性表达增强,阳性率为(11.33％±0.88％);伤后12h,表达继续增强,阳性率(75.67％±0.82％);伤后1d,在浸润的几乎所有单核细胞和多核粒细胞的胞质和胞核中均可见NFkB P65呈强阳性表达,阳性率为(97.33％±0.88％),表达达高峰,以后逐渐下降。结论 大鼠皮肤挫伤修复过程中,NFkB P65在挫伤后的炎症反应中发挥重要作用;同时,NFkB P65在挫伤区内多核粒细胞,单核细胞及成纤维细胞中的表达呈规律性变化,可对挫伤时间的推断提供参考。     

Electoral colorism: Candidate skin color and list placement in Ecuador

To what extent does candidate skin color influence party list placement in proportional representation systems? While candidate skin color is increasingly understood to play an important role in politics, the extent to which it shapes electoral opportunities and outcomes remains unclear. In this paper, we investigate whether party elites in list proportional representation systems place darker-skinned candidates in lower, less advantageous list positions than their lighter-skinned copartisans. Drawing on party lists from Ecuador’s 2021 National Assembly elections and an original measure of candidate skin color, we find evidence that candidate skin color is a significant determinant of list placement. This finding indicates that party lists reinforce color-based inequalities in political representation and reveals that a candidate’s skin color shapes their chances of winning elected office.     

复方守宫散辅助治疗晚期结直肠恶性肿瘤的疗效观察

目的 基于倾向性评分匹配法探讨复方守宫散辅助治疗晚期结直肠恶性肿瘤的疗效。方法 采用倾向性评分匹配法,将匹配成功的70例患者分为对照组（化学治疗）和观察组（复方守宫散联合化学治疗）,每组35例;比较两组患者瘤体客观疗效［客观缓解率（objective response rate,ORR）,疾病控制率（disease control rate,DCR）］、生活质量评分、免疫功能指标、安全性指标,并对生存期进行分析。结果 观察组ORR、DCR优于对照组（P＜0.05）;观察组患者治疗后功能维度（躯体功能、角色功能、情绪功能、认知功能、社会功能）,症状领域（疲劳、疼痛、恶心呕吐）评分改善程度显著优于对照组（P＜0.05）;观察组患者血清CD4+T细胞、CD8+T细胞、自然杀伤细胞水平,CD4+/CD8+均显著高于对照组（P＜0.05）;治疗组患者总不良反应发生率显著低于对照组（P＜0.05）;观察组的中位无进展生存期显著高于对照组（P＜0.05）,中位总生存期高于对照组（P＞0.05）。结论 相较于单纯化学治疗,复方守宫散与化学治疗联合应用能显著提高疗效,增强机体免疫力,改善晚期结直肠癌患者生活质量,降低化学治疗的毒性及不良反应,在一定程度上延长患者生存时间。     

DNA transfer during social interactions

Multiple DNA transfer has increasingly been brought up in court as potential means for the presence of the defendants DNA at the crime scene or on a piece of evidence. This has prompted several investigations into DNA transfer under very controlled and semi-controlled conditions, however little is published about DNA transfer in “uncontrolled” or real life situations.Here we examined the effects of multiple direct and indirect transfer of DNA within a small group of people and objects: three individuals participating in a social interaction of having a drink (jug of juice) together for 20 min. At the end of the tests all the surfaces of interest were sampled and analyzed.In many instances the last person or the only person to come in contact with the object was the main or the only depositor of the DNA detected on it. The jug was a clear vector for secondary DNA transfer. Interestingly, in many instances the participants acted as vectors for foreign DNA transfer.     

A validation study of mRNA markers for skin cell identification

The objectives of this study were to develop and optimize a multiplex of three skin specific gene markers; loricrin (LOR), corneodesmosin (CDSN) and keratin 9 (KRT9) and 1 house-keeping marker, β-actin (ACTB) using an endpoint PCR assay to analyze expression data from a range of relevant samples. Marker specificity and suitability were evaluated for their inclusion in future forensic casework. The presence of the three skin mRNA markers was successfully confirmed from swabs of human skin obtained from 20 individuals at each of 6 different body sites (forehead, neck, arm, palm, leg and sole). Significant variation was observed in the relative expression of the three genes across the body sites, with some individuals consistently failing to express one or more of the targets. Inter-individual variation was also evident. Accordingly, these markers must be used with caution in the identification of skin in forensic samples.     

Monte-Carlo Filesystem Search – A crawl strategy for digital forensics

Criminal investigations invariably involve the triage or cursory examination of relevant electronic media for evidentiary value. Legislative restrictions and operational considerations can result in investigators having minimal time and resources to establish such relevance, particularly in situations where a person is in custody and awaiting interview. Traditional uninformed search methods can be slow, and informed search techniques are very sensitive to the search heuristic's quality. This research introduces Monte-Carlo Filesystem Search, an efficient crawl strategy designed to assist investigators by identifying known materials of interest in minimum time, particularly in bandwidth constrained environments. This is achieved by leveraging random selection with non-binary scoring to ensure robustness. The algorithm is then expanded with the integration of domain knowledge. A rigorous and extensive training and testing regime conducted using electronic media seized during investigations into online child exploitation proves the efficacy of this approach.     

The ageing of bruises: A review and study of the colour changes with time

This work was inspired by a recent case of child abuse where the question of the age of the bruises on the body was raised. The first part of this paper reviews published work on bruises. It illustrates the paucity of work in this field and the absence of studies of the colour changes in bruises of human skin with time. The second part of this paper consists of our own study of the appearance of bruises. The aim was to identify the colour changes which occur in bruises and over what time-scale, in order to determine whether bruises can be aged by appearance. A total of 369 photographs were obtained of bruises aged <6 h and up to 21 days old, in 89 subjects aged 10–100 years. It was found that the development of a yellow colour was the most significant change (subjects aged <65, P < 0.001; subjects aged ≥65 years, P < 0.001). The development of a yellow colour occurred significantly faster in subjects aged < 65 years. (P < 0.001). The appearance of a blue and purple/black colour was of lesser significance. The appearance of a red colour did not alter significantly with time. From this study it was only possible to conclude that a bruise with a yellow colour was more than 18 h old.