小鼠皮肤切创愈合过程中M_3型乙酰胆碱受体的表达

目的 探讨小鼠皮肤切创愈合过程中损伤区M3受体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和Western印迹技术检测小鼠皮肤切创后不同时间段M3受体的变化情况.结果 正常皮肤组织的表皮、毛囊、皮脂腺、汗腺、皮肌层等均表达M3受体.伤后6～12h,损伤区M3受体阳性细胞以多形核粒细胞为主;1～3d,M3受体阳性细胞以单个核细胞和成纤维细胞为主;5～14d,M3受体阳性细胞主要为成纤维细胞.阳性细胞率在伤后6～12h逐渐增高,12h达高峰,1～5d略有下降,但保持较高水平,7d阳性细胞率再次达到峰值,随后逐渐降低.通过Westem印迹法检测显示,各个时间段均有M3受体阳性条带,其中12h和7d为M3受体两个表达高峰.结论 多形核粒细胞、单个核细胞和成纤维细胞均表达M3受体,提示其可能在皮肤切创愈合过程中起重要的作用;M3受体表达的规律性变化可用于损伤时间的推断.     

Atypical Suicide by Submachine Gun

In case of suicide, the presence of multiple entrance wounds is always suspicious. We report the case of a man who committed suicide by shooting himself three times in the chest and the skull with a submachine gun. The weapon seems to have been initially pointed in the precordium area with a lethal lesion of the proximal aorta. Two other projectiles were fired by the weapon and hit the neck and the skull of the deceased. The presence of three entrance wounds despite a first fatal wound could finally be explained by the characteristics of the weapon and wounds. Most suicides related to multiple gunshot wounds are explained by a first nonlethal shot but the use of an automatic weapon can also be found. In these last cases, medicolegal and criminalistics aspects become important in differentiating suicide and homicide.     

Complex Suicide by Self‐stabbing and Drowning: A Case Report and a Review of Literature

Sharp force injuries and drowning are methods exceptionally combined in complex suicides. We report a challenging case of complex suicide by self‐stabbing and drowning that illustrates the difficulty in discriminating between homicide and suicide in such circumstances of death. The corpse of a young man was found submerged in a river, stabbed nine times with two wounds that had penetrated the thorax and had caused lung injuries and a hemopneumothorax. The postmortem and histological examinations were consistent with a death caused by drowning, but the manner of death still remained undetermined. Police investigation finally concluded to a suicide, although no suicide note had been left and the victim had no underlying diagnosed mental disorder. The parameters that may help distinguish suicide from homicide at the autopsy should be interpreted in light of a thorough forensic investigation to determine the exact manner of death in such a case.     

Macroscopic Analysis of Axe and Hatchet Trauma in Fleshed and Defleshed Mammalian Long Bones*

Abstract: Recently, the authors have noted that many studies involving the characterization of chopping weapon wounds have used either semi‐fleshed or defleshed bones (e.g., J Forensic Sci 2001; 46: 228). As these types of specimens do not reflect the full range of actual cases of postmortem dismemberment or perimortem trauma, 11 fresh pig (Sus scrofa) articulated hind limbs, with contiguous surrounding flesh, were inflicted with wounds using two axes and two hatchets. Defleshed humeri and femora were subjected to the same treatment. While there were no great differences found between the fleshed and defleshed specimens, characteristics observed including entrance site width and the presence of chattering were inconsistent with some aspects of Humphrey and Hutchinson’s study (J Forensic Sci 2001; 46: 228). Further, it was found that curve transverse and spiral fractures were prevalent in femora, while longitudinal fractures were prevalent in fibulae. Hence, fracture types may play a role in characterizing some wounds caused by chopping weapons.     

损伤皮肤酯酶显微定位、定量与损伤时间推断

作者用显微分光光度计扫描法,对32只 Hartly 豚鼠的实验性损伤以及8例人体损伤的皮肤组织中的酯酶,进行定位、定量研究。发现生前损伤后,创壁0.4mm 以内真皮胶原纤维等间质即刻出现酯酶着色,存活时间越长,着色就越深、范围越大。生前各时间组互相间有显著差异。所有的生前损伤组创缘酯酶含量及平均单位面积酶含量与正常皮肤及死后损伤组差别均极显著。人体损伤皮肤组织酯酶定位及含量变化与豚鼠所见一致。因此,作者认为损伤皮肤酯酶定位定量分析以推断损伤后存活时间,已可应用于法医实际案例鉴定中。作者还根据对抑制剂的反应认为创缘真皮胶原纤维上所显示的酯酶为 B-酯酶。     

兔不同时间切创中肌细胞核DNA的定量测定

为了使损伤时间推断手段更加精确化,为损伤时间推断提供新的方法,我们利用显微分光光度计测定兔皮肤切创创口内肌细胞核DNA 含量,结果发现:正常肌细胞核DNA 含量为18. 420Au,而损伤后创外周区内肌细胞核的DNA 含量立即迅速下降。伤后1h 为17. 274Au;伤后3h 为8. 672Au,达最低水平,随着损伤及经过时间的延长,DNA 含量又逐渐回升,伤后6、8、12,24h 的含量分别为12. 563、13. 608、14. 743,16. 448Au。上述结果说明,损伤区域内肌细胞核内DNA 的含量与损伤时间有明显关系,DNA定量分析可作为损伤时间推断的一个重要根据。     

人体骨骼上菜刀痕迹的检验及同一认定

目的 对人体骨骼上刀痕进行致伤工具同一认定的检验和研究.方法 用同一把菜刀的相同部位分别砍击骨骼与新鲜灌木,通过对骨骼上刀痕进行组织学处理以显现致伤工具的痕迹,并使用比对显微镜将骨骼与灌木上的砍痕进行比对,分析骨质断面的痕迹特征.结果 菜刀在骨骼上形成的砍切痕迹线条与比对样本的砍切痕迹线条可以完全拼接.结论 显微镜下可直观、清晰地观察到致伤工具在骨骼上留下的痕迹,为致伤工具的推断提供了新的方法.     

Time-dependent Appearances of Myofibroblasts during the Re-pair of Contused Skeletal Muscle in Rat and Its Application for Wound Age Determination

Objective To research the relation between the time-dependent appearances of myofibroblasts during the repair of contused skeletal muscle in rat and wound age determination. Methods A total of 35 SD male rats were divided into the control and six injured groups according to wound age as follows: 12 h, 1 d, 5 d, 7 d, 10 d and 14 d after injury. The appearances of myofibroblasts were detected by HE staining, immunohistochemistry and confocal laser scanning microscopy. Masson’s trichrome staining was utilized to examine collagen accumulation in the contused areas. Results Immunohistochemical staining showed that α-SMA+myofibroblasts were initially observed at 5 d post-injury. The average ratio of myofibroblasts was highest at 14 d post-injury, with all samples, ratios more than 50%. In the other five groups, the average of α-SMA positive ratios were less than 50%. The collagen stained areas in the contused zones, concomitant with myofibroblast appearance, were increasingly augmented along with advances of posttraumatic interval. Conclusion The immunohistochemical detection of myofibroblasts can be applied to wound age determination. The myofibroblasts might be involved in collagen deposition during the repair of contused skeletal muscle in rat.     

Breaking point? An analysis of fatal stab wounds to the torso in Ireland between 2011 and 2018, examining the extent of rib fractures

This study examines the pattern of rib injuries occurring in cases of fatal torso stab wounds in Ireland between 2011 and 2018. It has been suggested by previous studies that rib fractures are not commonly sustained in stab wounds to the torso. We wanted to ascertain whether this was the case, as our data suggested that rib fractures were frequent, and where a rib is fractured there is a higher chance of organ injury and death, making this an important area of study. One hundred and forty seven cases of fatal stab wounds from an eight-year period were retrospectively reviewed. Fatal stab wounds to other body areas, were excluded; leaving a total of 104 cases with stab wounds to the torso. We found that 69.2% of cases had rib injuries, a figure significantly higher than previously reported. Our data suggests that stab wounds to the torso often fracture ribs, putting the underlying organs at increased risk of injury and perhaps contributing to fatality. The amount of force needed to cause a rib fracture can be difficult to quantify and indeed from the high percentage of rib fractures sustained in our data it appears that the ribs may be fractured regardless of the amount of force used; this is borne out by the finding that self-inflicted injuries also caused rib fractures. Our study shows that other factors, such as anatomical positioning and wound depth may have a greater bearing than force in terms of whether a rib fracture is sustained.     

An anthropological analysis of gunshot wounds to the chest

This analysis of gunshot trauma to the bony thorax examines 87 handgun and rifle wounds from documented cases in an effort to corroborate an earlier report and to provide the forensic community with additional literature in this area. Specifically, this study tests whether the trauma signatures associated with gunshot wounds in the bony thorax are useful in determining the direction of fire. Because the ribs occupy a significant portion of the bony thorax, they are struck more frequently than other bones and, consequently, they are the focus of this report. This study confirmed that bullets can leave distinctive markers on ribs that indicate the direction of fire, including depressed fractures, bone fragments displaced in the direction of the bullet's path, and beveling. Although forensic anthropologists can determine the direction that a bullet was traveling when it struck a given rib, they cannot give a definitive statement about the number or sequence of gunshots without supporting soft tissue evidence.