Fatal hemorrhage from a periumbilical wound: Stabbing or hemorrhage from a caput medusae?

Varices are the main clinical manifestation of portal hypertension, and their bleeding is the predominant cause of mortality from this condition. Periumbilical varices are known as “caput medusae.” Reports of their bleeding are rare, with only three fatal cases described in the literature. The antemortem diagnosis is relatively simple, while the postmortem diagnosis is more complex. This paper is the first report of fatal hemorrhage from a caput medusae for which the diagnosis was made postmortem, thanks to a complete diagnostic process including scene and circumstances, medical history, and autopsy with detailed histology. The circumstantial analysis showed the presence of a large amount of blood at the scene, blood which originated from a small abdominal wound; an analysis of the subject's clinical data reported that he was affected by portal hypertension. The autopsy revealed some dilated and convoluted veins in the subcutaneous tissue of the umbilical region; a fistula between these veins and the abdominal wound was detected. The histological study confirmed the presence of periumbilical varices, one of them ruptured and connected with the overlying skin. The cause of death was attributed to a massive hemorrhage generated by a periumbilical varix in a patient affected by portal hypertension.     

Validity of the use of porcine bone in forensic cut mark studies

Porcine bone is often used as a substitute for human bone in forensic trauma studies, but little has been published on its comparative mechanical behavior. The factors affecting mechanical properties and therefore selection of bone models are complex and include the age of the animal at death, and physiological loading conditions, the latter being of particular relevance when using a quadrupedal animal as a human substitute. The regional variation in hardness of adult and infant porcine bones was investigated using Vickers’ indentation tests and compared to published data for human limb bones to relate differences to inherent genetic effects and loading influences, and to examine the validity of the porcine‐human model. Significant differences in hardness were observed both along and around the adult porcine humerus and femur, but no significant differences were found along the length of the infant bones. Significant differences were found between the forelimb and hindlimb, but only in the infant specimens. The hardness values for porcine adult cortical bone from the femur (52.23 ± 1.00 kg mm^?2) were comparable to those reported in the literature for adult human cortical bone from the fibula, ilium, and calcaneus. These data will help inform subject selection in terms of both species and bone type for use in future trauma studies.     

Analysis of histomorphometric variables: Proposal and validation of osteon definitions

Histological analysis of bone tissue has been used to explore a variety of questions relating to age-at-death, habitual behaviors, health, and nutritional stress. Identification of intact and fragmentary osteons is of key interest to many researchers in these studies, yet the definitions of these features vary between researchers making cross-study comparisons problematic. Furthermore, histological variable definitions are often ambiguous or require subjective classifications by the observer. As a result, and as indicated by previous studies, observer error and misclassification of certain variables, namely intact and fragmentary osteons, can be significant. This study proposes new definitions for intact and fragmentary osteons that are designed to limit observer subjectivity and also explore efficacy of combining osteon types into one variable. A sample of 30 6th rib cross-sections from a modern forensic population was used to test the validity of the proposed definitions. Observations of intact osteon population density (OPD(I)) and fragmentary osteon population density (OPD(F)) were made by three observers for each cross-section. These observations were used to explore the interobserver error associated with the proposed definitions and determine if combining variables into one variable (OPD) mitigates persisting classification difficulties. Results indicate that the proposed definitions significantly reduce interobserver error and misclassification of intact and fragmentary osteons. However, the interobserver error associated with fragmentary osteons is still high. Evaluation of the variables independently indicates that combining variables has potential to reduce the predictive strength of an age estimation model and the ability to interpret age-related bone remodeling.     

陈旧性骨骼DNA提取技术的研究

对陈旧性骨骼建立一个高回收率并能除去 PCR 反应抑制物的提取 DNA 的方法。采用 CTAB 法提取 DNA。结果显示,该方法不但能有效去除 PCR 抑制物,而且对水泡、火烧、土埋以及10年左右的骨骼所提取的 DNA 均能成功地进行荧光标记 STR 多基因座扩增检验。实验表明,该方法稳定,重复性好,适合陈旧骨骼标本的 DNA 提取。     

大鼠颅骨材料力学和骨质参数的增龄性变化

目的 通过检测大鼠颅骨材料力学和骨质参数,探讨二者关系及其与年龄的相关性.方法 48只健康雄性SD大鼠按年龄分为2、4、6、8、17、26、52和104周龄组,每组6只.利用KDⅡ-0.2型微机控制电子万能试验机压缩右侧颅盖骨检测其材料力学参数(极限载荷、压缩强度、压缩模量),之后分离颅骨骨片进行Micro-CT系统扫...     

A Powder-free DNA Extraction Workflow for Skeletal Samples

The processing of skeletal material poses several challenges for forensic laboratories. Current methods can be laborious, time-consuming, require dedicated equipment, and are vulnerable to contamination. In this study, various sample mass (1 × 50 mg, 3 × 50 mg, and 1 × 150 mg chip(s)) and incubation times (2, 4, and 16 h) were tested using the PrepFiler^® BTA™ Forensic DNA Extraction Kit to digest whole bone chips in lieu of powdering. The most effective method was then applied to bones and tooth fragments collected from contemporary human cadavers exposed to various environmental conditions using an automated platform. Over a third of the samples tested generated full DNA profiles without having to powder the bone/tooth fragment or further alter the manufacturer's protocol. However, for most samples resulting in incomplete STR profiles due to low amounts of DNA, slightly better results were achieved with powdered tissue. Overall, this work demonstrates the potential use of a faster, nonpowdering DNA extraction method for processing skeletal samples as an effective first-pass screening tool.     

大黄泄浊颗粒保留灌肠对非透析慢性肾脏病肾性骨病湿热证患者骨密度及血清骨形成蛋白-7的影响

目的观察非透析慢性肾脏病(chronic kidney diseases,CKD)肾性骨病湿热证患者腰椎骨密度(bone mineral density,BMD)和血清骨形成蛋白-7(bone morphogenetic protein-7,BMP-7)水平及大黄泄浊颗粒保留灌肠的干预作用。方法将64例非透析CKD 3~5期湿热证患者随机分为治疗组和对照组各32例(结果每组失访2例),并设正常组20例。两组均给予基础治疗,治疗组加用大黄泄浊颗粒保留灌肠,每日1次,疗程均为8周。治疗前后分别观察两组血尿素氮(blood urea nitrogen,BUN),血清肌酐(serum creatinine,SCr)、钙(calcium,Ca)、磷(phosphorus,P)、碱性磷酸酶(alkaline phosphatase,ALP)、甲状旁腺激素(parathyroid hormone,iPTH)、BMP-7水平及第2—4腰椎BMD。结果治疗组临床疗效显著优于对照组(P0.05)。治疗4周末和8周末,两组中医证候积分均较前一时点显著降低(P0.05),且治疗组积分均显著低于对照组(P0.05)。治疗组在降低BUN、SCr和血清P、iPTH、ALP方面,以及在升高血清Ca和肾小球滤过率估算值方面均显著优于对照组(P0.05)。与正常组比较,CKD病例组BMD和BMP-7均显著降低(P0.05);两组治疗后BMD和BMP-7均显著升高(P0.05),而治疗组BMD和BMP-7升高值均显著大于对照组(P0.05)。结论非透析CKD肾性骨病湿热证患者BMD和BMP-7水平均显著低于健康人群;大黄泄浊颗粒保留灌肠可防治非透析CKD肾性骨病,其机制可能与改善肾功能及升高血清BMP-7含量有关。     

青少年骨龄鉴定及其相关问题

本文综述了骨龄研究和应用历史,以及骨龄评测的新方法和新技术,讨论了骨骼发育的影响因素、骨龄标准时效性、骨龄评测部位选择及法医骨龄鉴定等相关问题。     

中国汉族人耻骨性别判定的研究

目的为了探讨耻骨性别判定的更为简便可靠的方法。方法对96副已知生前确切性别的耻骨进行了性别差异的研究,其中男性耻骨73副,女性耻骨23副。测量项目有:缘枝角,耻骨宽,耻骨联合面的高及厚。结果将耻骨的测量数据输入电脑,用SPSS软件,对耻骨的测量数据进行了统计分析,建立了耻骨性别判定的判别方程。结论其性别判别率最高可达95.5%,该方法可以用于法医学实践。     

A New Method for Determination of Postmortem Interval: Citrate Content of Bone*

Abstract: Few accurate methods exist currently to determine the time since death (postmortem interval, PMI) of skeletonized human remains found at crime scenes. Citrate is present as a constituent of living human and animal cortical bone at very uniform initial concentration (2.0 ± 0.1 wt %). In skeletal remains found in open landscape settings (whether buried or not), the concentration of citrate remains constant for a period of about 4 weeks, after which it decreases linearly as a function of log(time). The upper limit of the dating range is about 100 years. The precision of determination decreases slightly with age. The rate of decrease appears to be independent of temperature or rainfall but drops to zero for storage temperature <0°C.