90例行人撞击伤案例分析

目的 探讨行人交通事故和致伤车辆类型的关系,总结其规律.方法 回顾90例行人交通事故案例,分析致伤车辆、损伤部位、损伤特点、严重程度之间的关系. 结果 不同类型致伤车辆所致的撞击伤好发部位取决于受撞击时人体的姿势和车头突出部位的高度,其损伤特点与作用力大小、方向和接触面光滑程度相关. 结论 通过对行人撞击伤的损伤部位、损伤特点、严重程度的分析,可以推断致伤车辆类型.     

损伤经过时间的实验研究

作者在全身麻醉及无菌条件下,通过在大白鼠背部皮肤造成的切创创口,于伤后不同时间杀死.每组中1只于处死前8小时注射秋水仙碱以观察核分裂.取损伤处皮肤,经福尔马林固定、石蜡切片、HE染色、Gorden和Sweet染色(网状纤维)、Weigert染色(弹力纤维)、PTAH染色(纤维蛋白)和Van Gieson染色,于显微镜下观察.结果发现创口逐日缩小,但其中24小时创口较12小时创口有所扩大,伤后第6～7日创口呈突击式缩小.通过组织学变化观察,作者对创口收缩现象在判断损伤时间的意义及形成机理作了讨论.     

Concordance Rate for the Identification of Distant Entrance Gunshot Wounds of the Back by Experienced Forensic Pathologists Examining Only Images of Autopsies

The images of 66 gunshot entrance wounds with a defect on the back, a bullet in the body, hemorrhage along the wound track, and logical certainty that it was an entrance wound were collected from the files of a moderately busy medical examiner's office. Participants numbering 22 board‐certified forensic pathologists viewed a single digital archival image of each of the 66 entrance wounds randomly mixed with 74 presumptive exit wounds to determine whether they were entrance or exit wounds. The concordance rate for correctly identifying the 66 logically known entrance wounds was 82.8% with a range from 58% to 97%. This pilot study was conducted to provide an evidence‐based approach to the interpretation of the direction of gunshot wounds by reviewing pathologists with access only to archival photographs, and it is not a measure of the accuracy to distinguish entrance from exit wounds when given all of the circumstances.     

小鼠皮肤损伤愈合过程中PI3K/Akt通路的作用

目的探讨小鼠皮肤损伤愈合过程中损伤区磷脂酰肌醇-3-激酶(phosphatidylinositol-3-kinase,PI3K)、磷酸化磷脂酰肌醇-3-激酶(phospho-PI3K,p-PI3K)、蛋白激酶B(protein kinase B,PKB,又称Akt)和磷酸化蛋白激酶B(phospho-Akt,p-Akt)的表达及其随时间的变化规律。方法应用免疫组织化学染色、Western印迹法和real-time PCR技术检测小鼠皮肤损伤不同时间段PI3K、Akt、p-PI3K及p-Akt的变化情况。结果免疫组织化学染色显示,皮肤损伤后,PI3K、p-Akt阳性染色出现在单核细胞和成纤维细胞,峰值出现在组织修复期。Western印迹法显示,各个时间段均有PI3K、p-PI3K、Akt、p-Akt的阳性条带,其中p-PI3K、p-Akt表达的峰值出现在炎症期和增生期,PI3K、Akt表达的高峰出现在组织重建期。real-time PCR结果显示,PI3K m RNA的峰值出现在炎症期和组织重建期,Akt m RNA的峰值出现在组织重建期。结论在皮肤损伤愈合过程中,PI3K、Akt、p-PI3K及p-Akt的表达变化呈现不同的规律性并有较好的时间依赖性,PI3K/Akt通路的表达规律可以用于法医学损伤时间推断。     

An Unplanned Complex Suicide by Multiple Blank Cartridge Gunshots and Cutting

Blank firing guns are readily accessible in most countries due to an absence of legal regulations. These weapons are capable of causing lethal injuries. We report a rare case of secondary (unplanned) complex suicide committed with a knife and blank cartridge pistol. A 59‐year‐old man was found dead with three superficial incisions in his neck and a gunshot wound to the chest. The external examination revealed an entrance wound in the left chest region consistent with contact shooting. The appearance of a muzzle imprint suggested two discharges. The autopsy showed a slightly hemorrhaged but otherwise intact pericardium, blood in the pericardial sac, and a channel‐like defect in the anterior wall of the left cardiac ventricle. The cause of death was attributed to cardiac tamponade. To the best of our knowledge, this is the first reported case of unplanned complex suicide involving an unmodified blank firing gun.     

Fatal Injuries of Law Enforcement/Correctional Officers Attacked with Sharp‐Edged Weapons,

According to the National Law Enforcement Memorial Fund, there were 117 law enforcement fatalities in the United States in 2015. Assaults with sharp‐edged weapons have resulted in a total of over 400 fatalities in the United States. The goal of the current research was to examine sharp‐edged weapon assaults against law enforcement and correctional agents that resulted in a fatal outcome. A total of twelve autopsy reports were reviewed from across the United States. Four cases involved law enforcement officers, seven involved correctional officers, and one was an off‐duty border officer. The male‐to‐female ratio was 11:1. A total of 70.2% of the wounds analyzed were stab wounds (n = 85), and 29.8% of the wounds were slash wounds (n = 36). Based on this review, the neck, shoulder, and chest regions were the most vulnerable to single fatal stab/slash wounds. Multiple stab/slash wounds often resulted in exsanguination. The use of body armor was only noted in one case.     

Characteristics and Frequency of Chipping Effects in Near‐Contact Gunshot Wounds

The presence of “chipping” or “flaking” around the edges of gunshot entry wounds has been described among the characteristics of gunshot wounds in bone. In this study, the real frequency of such a peculiar feature was investigated. The presence of “chipping” was assessed on 22 gunshot wounds fired at a near‐contact range on bovine ribs with 9‐mm bullets. As controls, five samples were shot with a 3 cm range, and five from 40 cm. In 77% of cases shot at near‐contact range, a detachment of small fragments of the upper layers of bone was detected, mainly with a circumferential disposition, whereas this feature was lacking in control samples. The study demonstrated the frequency of “chipping” and that it may probably be due to a combined ballistic effect of impact of the bullet itself and expansion of gases. It may be thus considered indicative of close‐range shots.     

The detection of metallic residues in skin stab wounds by means of SEM-EDS: A pilot study

The morphological analysis of stab wounds may often not be accurate enough to link it with the type of wounding weapon, but a further evaluation may be performed with the search for metallic residues left during the contact between the instrument and the skin. In this study, Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) was applied to the study of cadaveric stab wounds performed with kitchen knives composed of iron, chromium and nickel, in order to verify the presence of metallic residues on the wound's edge. Two groups of 10 corpses were selected: group A, including victims of stab wounds and a control group B (died of natural causes). Samplings were performed on the lesions and in intact areas of group A, whereas in group B sampling were performed in non-exposed intact skin. Samples were then analysed with optical microscopy and SEM-EDS. In group A, optical microscopic analysis showed the presence of vital haemorrhagic infiltration, while SEM-EDS showed evidence of microscopic metal traces, isolated or clustered, consisting of iron, chromium and nickel. Moreover, in two cases organic residues of calcium and phosphate were detected, as a probable sign of bone lesion. Control samples (group A in intact areas and group B), were negative for the search of exogenous material to optical microscopy and SEM-EDS. The results show the utility and possible application of the SEM-EDS in theidentification of metallic residues from sharp weapons on the skin.     

Effects of Decomposition on Gunshot Wound Characteristics: Under Moderate Temperatures with Insect Activity

Abstract:  Previous studies document characteristics of gunshot wounds shortly after they were inflicted. This study was conducted to determine if the early stages of decomposition obscure or alter the physical surface characteristics of gunshot wounds, thereby affecting the quantity and quality of information retrievable from such evidence. The study was conducted in August and September, 2005 in Nova Scotia, Canada in forested and exposed environments. Recently killed pigs were used as research models and were shot six times each at three different ranges (contact, 2.5 cm, and 1.5 m). Under these test conditions, the gunshot wounds maintained the characteristics unique to each gunshot range and changes that occurred during decomposition were not critical to the interpretation of the evidence. It was concluded that changes due to decomposition under the conditions tested would not affect the collection and interpretation of gunshot wound evidence until the skin was degraded in the late active or advanced decay stage of decomposition.     

Macroscopic,Microscopic, and Chemical Assessment of Gunshot Lesions on Decomposed Pig Skin

Abstract: Very little literature exists on gunshot wounds on decomposed material. In this study, seven pig heads underwent a shooting test. Entrance wounds from the first head underwent neutron activation analysis (NAA) and histological testing immediately after the firing test; the other six heads were exposed to two different environments (open air and soil) and analyzed by radiochemical and histological tests every 15 days. Gunshot wounds in air maintained their morphological characteristics, and those in soil showed severe alteration after 5 weeks. Microscopic testing verified positive results for lead in all gunshot wounds in open air, whereas in most of those in soil lead could not be detected. Radiochemical analysis performed by NAA yielded for all gunshot wounds but one antimony quantities in the range of 0.07–13.89 μg. In conclusion, it may be possible to detect residues of antimony even in degraded tissues.