酶消化联合强酸消化法的硅藻检验CSCD

目的采用酶消化联合强酸消化法对溺死尸体的器官进行硅藻检验,并评价其应用价值。方法收集40例本地区确证为溺死的尸体,每例提取肺、肝、肾组织及现场水样,分别采用强酸消化法、酶消化联合强酸消化法、酶消化法对组织样本进行硅藻检验,从消化时间、消化能力、硅藻检出率等方面进行比较分析。结果在消化时间、消化能力方面,酶消化联合强酸消化法明显优于酶消化法;在硅藻检出率方面,酶消化联合强酸消化法明显优于强酸消化法。结论酶消化联合强酸消化法结合了强酸消化法和酶消化法的优点,并且操作安全,环境污染小,具有一定的推广和实践价值。     

Frozen: Thawing and Its Effect on the Postmortem Microbiome in Two Pediatric Cases,

Previous postmortem microbiome studies have focused on characterizing taxa turnover during an undisturbed decomposition process. How coexisting conditions (e.g., frozen, buried, burned) affect the human microbiome at the time of discovery is less well understood. Microbiome data were collected from two pediatric cases at the Wayne County Medical Examiner in Michigan. The bodies were found frozen, hidden in a freezer for an extended time. Microbial communities were sampled from six external anatomic locations at three time points during the thawing process, prior to autopsy. The 16S rRNA V4 gene amplicon region was sequenced using high‐throughput sequencing (Illumina MiSeq). Microbial diversity increased, and there was a distinct shift in microbial community structure and abundance throughout the thawing process. Overall, these data demonstrate that the postmortem human microbiome changes during the thawing process, and have important forensic implications when bodies have been substantially altered, modified, and concealed after death.     

MicroRNA在心血管疾病方面的研究现状及应用前景

MicroRNA(miRNA或mi R)是一类21~25nt大小的高度保守的内源性单链非编码RNA,在生物体内广泛存在。近年来,在临床研究中与心血管疾病相关的mi RNA不断得以证实,但其在法医学鉴定方面的研究尚未有报道。本文就mi RNA的研究进展及其在心血管疾病中的应用,以及在心源性猝死法医学鉴定中的应用前景进行综述。     

道路交通事故死亡案例驾驶员损伤特征分析

目的针对交通事故中驾驶员和乘客的损伤,辨别驾驶员损伤的特征性改变,从而为交通事故中准确认定驾驶员提供科学的证据支撑。方法对2006—2014年间,黑龙江省垦区内126例汽车交通事故死亡案例数据进行回顾性研究,分析汽车事故死亡案例驾驶员损伤特征,探讨驾乘人员损伤的法医学鉴定要点。结果驾驶员颈部、胸部、腹部的损伤多见,可检见汽车部件所致特征性损伤。乘员仅头面部及四肢与汽车接触部位有特征性损伤,其他部位未检见可明确汽车部件所致特征性损伤。结论损伤部位、类型与死亡人员的驾乘身份有关。     

缺氧相关microRNA在窒息死亡原因推断中的意义

在缺氧条件下microRNA(miRNA)能与转录因子等相互作用,调节细胞代谢,血管再生,血细胞生成,细胞增殖、分化及凋亡等生理过程,这些过程可能在窒息导致的死亡中发挥重要作用。本文拟对缺氧条件下miRNA的调节功能及缺氧对miRNA生物合成的影响进行综述,以期为miRNA在法医学窒息死亡原因推断中的研究提供新思路。     

金属硫蛋白1A和2A的mRNA时序性表达(英文)

目的研究大鼠肌肉挫伤后金属硫蛋白(metallothionein,MT)1A m RNA、MT2A m RNA的时序性表达。方法 54只SD大鼠被分成挫伤组(挫伤后0.5、1、6、12、18、24、30和36 h组各6只)和对照组(6只)。所有总RNA均取自大鼠的骨骼肌。利用SYBR GreenⅠ法进行RT-q PCR检测大鼠挫伤骨骼肌中MT1A m RNA、MT2A m RNA的相对表达量。结果 MT1A m RNA、MT2A m RNA在损伤后的变化趋势与损伤时间具有一定的相关性。除了挫伤后0.5 h组外,其余各组MT1A m RNA、MT2A m RNA的表达量与对照组相比差异均有统计学意义(P0.05)。损伤后1 h、6 h、12 h、18 h MT1A m RNA和MT2A m RNA的相对表达量呈现逐渐上升的趋势,在18 h时达到了峰值,分别为对照组的(239.41±15.20)倍和(717.42±50.76)倍;损伤后24 h时两者的表达量均明显减少;损伤后30 h再次上升,随后下降。结论 MT1A m RNA、MT2A m RNA可能对损伤时间推断有一定的意义。     

Histopathological,histochemical and biochemical postmortem changes in induced fatal hypothermia in rats

Reaching a postmortem diagnosis of hypothermia is challenging in forensic practice. Therefore, this study was conducted to detect the histopathological, histochemical and biochemical changes that occur in adult albino rats following exposure to induced fatal hypothermia. Twenty-four adult albino rats were divided into the negative control, moderate hypothermia, severe hypothermia and hypoxia groups. Rats in the control group were euthanized when those in the moderate hypothermic group died. Blood samples were collected via heart puncture, and the cerebrum, heart, suprarenal gland, kidney, liver and skeletal muscle were removed to investigate the biochemical, histochemical and histopathological changes. Postmortem assessment depicted significant changes in lipid peroxidation, represented by increased malondialdehyde levels in the studied organs of the rats in hypothermic and hypoxia groups. Histopathological examination of the rats’ organs revealed degeneration and necrosis in the hypothermia and hypoxia groups. Sections taken from the severe hypothermic rats revealed a loss of normal cardiac tissue architecture, necrotic changes in the pyramidal cells in the cerebral cortex, and massive necrosis, mainly in the tubules of the renal cortex and medulla. These findings suggest that histological changes might be used as biochemical markers for postmortem diagnosing of fatal hypothermia, particularly in severe hypothermic conditions.

Key points

• Death by hypothermia is a serious public health problem worldwide.
• Confirming a diagnosis and determining the cause of death in cases of hypothermia are among the most difficult practices in forensic medicine.
• Death by hypothermia might be associated with structural abnormalities in various organs.
• Studies using different tissue staining techniques will enable an overall illustration of the role of histopathological changes in body organs as indicators of hypothermia.

     

Fatal Aspiration of Barium Sulfate in a Case of Myasthenia Gravis: A Case Report and Review of Literature

Barium contrast radiography is a usual procedure performed for detecting lesions of the digestive tract using barium sulfate on X-ray irradiation. The aspiration of barium contrast is an uncommon but well-documented complication occurring accidentally during examinations of the upper gastrointestinal system using contrast media. Certain conditions that affect the anatomical and functional integrity of the oropharynx and esophagus can be predisposing factors. Barium is an inert material that can cause symptoms varying from an asymptomatic mechanical obstruction to severe respiratory distress that can result in death when aspirated. Sudden death due to aspiration of barium is rarely reported in the literature. We report a case of a 50-year-old female who suddenly developed difficulty in breathing, followed by loss of consciousness during barium swallow procedure due to aspiration of barium contrast. She could not be revived and died within a few minutes of the episode. The predisposing factor was the weakness of the muscles of deglutition due to myasthenia gravis. We also reviewed the literature available on cases resulting from the aspiration of barium sulfate during the barium study procedures. We considered the factors like the age, indications, the distribution of barium in the lungs, clinical presentation, the period of survival, and cause of death. We came across only four cases of death within 24 h following the aspiration of barium. This case report and review of literature emphasize the importance of consideration of predisposing factors before conducting barium contrast radiography and also the possibility of sudden death.     

A rare case of sudden death due to IgG4-related giant coronary artery aneurysms

Immunoglobulin G4-related disease (IgG4-RD) is a fibro-inflammatory condition that can affect many organs, either simultaneously or metachronously. In recent years, IgG4-related vascular complications of larger arteries such as the aorta and iliac arteries have been increasingly identified. Among vascular complications, coronary artery involvement in the forms of either periarteritis or coronary artery aneurysms (CAAs) has also been reported; however, are very rare in comparison. This case report presents a rare case of a sudden death due to occlusive thrombosis of IgG4-related giant CAAs measuring up to 10 cm in diameter, demonstrates their possible clinical progression, and shows how they can distort normal anatomy which may then pose challenges in the interpretation of postmortem-computed tomography scans. It also briefly discusses the diagnosis of IgG4-RD in arteries, both clinically and in the postmortem setting.     

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.