大鼠限制性体位窒息模型中膈肌Fn和HSP70的免疫荧光组化观察

目的观察Fn和HSP70在限制性体位窒息死亡的大鼠膈肌中的表达情况,进一步探讨限制性体位窒息死亡的机理。方法分组建立限制性体位窒息死亡大鼠模型,采用免疫荧光组织化学方法研究大鼠膈肌的Fn和HSP70的表达情况,并将荧光照片进行灰度值分析,比较抗原在不同组别间的表达差异。结果在Fn检测中,限制性体位窒息死亡组大鼠的膈肌肌内膜上有明亮荧光,肌纤维间隙的荧光强度明显大于对照组。在HSP70检测中,肌纤维内的荧光强度随着体位性限制程度的加重而明显增加。结论采用免疫荧光组织化学检测膈肌Fn和HSP70抗原的表达,对判断限制性体位窒息死亡者膈肌的损伤是一种有意义的手段。     

悬挂双前肢致死兔的膈肌超微结构的研究

目的研究悬挂体位下窒息死亡动物的膈肌超微结构变化。方法取悬挂双前肢体位家兔的膈肌和腓肠肌组织,以勒颈致死家兔的膈肌和腓肠肌组织为对照,采用透射电镜方法观察其超微结构的变化。结果悬挂组膈肌的细胞核、细胞质、细胞膜均有缺氧损伤的征象,其中肌纤维内的肌原纤维、线粒体病变尤为严重;勒颈组膈肌的改变与悬挂组膈肌相类似,但程度上较轻微;悬挂组腓肠肌轻微病变,但肌原纤维无明显改变;勒颈组腓肠肌无明显改变。结论悬挂体位造成了膈肌纤维超微结构的损伤,形成了机体缺氧的病理基础,可导致死亡;本实验的结果可为限制性体位窒息死亡的法医学鉴定标准提供实验性的形态学依据。     

限制性体位窒息死亡的国内外研究进展

限制性体位窒息是指被限制于某种异常体位,造成了自主呼吸功能的障碍引起的窒息,严重时可引起死亡,属机械性窒息中的特殊类型。从国内外有关案例报道来看,限制性体位窒息死亡可以发生在多种环境、体位下。由于早年限制性体位窒息死亡的案例没有引起足够的重视,其作为一个法医学课题起步较晚。近年来由于发生率猛增,已引起国内外法医学家们的极大关注,并对其发生机理、鉴定标准等方面进行了大量研究,但从研究的成果来看,尚不能形成一些客观的鉴定指标,由此,国外关于限制性体位窒息的研究重点已转向其发生的危险因素评估及如何预防。本文就其死亡机理、危险因素及预防、鉴定标准和展望等方面作一综述。     

家兔双前肢悬挂致死过程中的电生理研究

目的探讨悬挂体位致窒息死亡的电生理方面的机制。方法成年家兔12只,雌雄不限。随机分为两组:一组监测膈肌肌电图,另一组监测肋间肌肌电图、心电图、脑电图。取仰卧位固定,手术暴露膈肌和肋间肌,引导肌电图;同时引导标准Ⅱ导联心电图和脑电图。然后将家兔固定双前肢悬挂,连续监测实验过程中家兔的心电、脑电、肌电图的变化情况,直至其死亡。结果悬挂末期和悬挂初期相比,膈肌肌电频率下降(P<0.05)、呼吸波持续时间、振幅和面积均有延长或增多(P<0.05)、最大传导速度无变化;肋间肌仅见肌电频率下降(P<0.05);脑电振幅降低(P<0.01)、δ波增多(P<0.01)、β波减少(P<0.05);心电仅见各波形振幅的降低(P<0.01)。膈肌肌电频率的下降最早,脑电频率的下降次之,肋间肌肌电的下降最晚(P<0.01)。结论悬挂体位致窒息死亡的机制的始动因素是呼吸运动受限,并最终形成外周性呼吸肌疲劳和呼吸中枢缺氧性衰竭而发生死亡。     

兔悬挂双前肢致死组织中PKC、AchE、HSP70的活性变化

目的观察兔悬挂双前肢致死不同组织中PKC、AchE、HSP70的活性变化,探讨其在死亡机制中的作用。方法家兔双前肢悬挂致死亡,取膈肌、肋间肌、心肌、腓肠肌、大脑、脑干、肝、肾、肺等组织,以勒颈、颅脑损伤和疾病死亡相应组织为对照。采用SP法对上述组织中蛋白激酶C(PKC)、乙酰胆碱酯酶(AchE)和热休克蛋白70(HSP70)进行免疫组化染色,观察其活性,并采用多组独立样本的Kruskal-Wallis秩和检验方法,对结果进行统计学分析。结果膈肌、肋间肌和大脑组织细胞质中PKC免疫组化阳性染色,悬挂组较其它组增强(P0.05);膈肌、肋间肌、心肌、大脑和肝细胞质及肌组织神经束中AchE免疫组化阳性染色,悬挂组较其它组增强(P0.05);大脑、心、肺中HSP70免疫组化阳性染色,悬挂组较其它组增强(P0.05)。结论PKC、AChE、HSP70通过不同机制,在悬挂双上肢体位性窒息死亡中起到一定作用,本文结果可为相关研究及鉴定提供实验依据。     

死后尸体CT影像学特征变化研究进展

死后尸体变化于死亡后立即出现,会不同程度地改变尸体原有的结构特征,并在计算机断层扫描(computed tomography,CT)图像上表现出特异性改变,有时易出现假阳性与假阴性,影响损伤或疾病的鉴别。本文系统地综述了死后尸体CT影像学的变化特点,以进一步拓展虚拟解剖技术在法医病理学鉴定实践中的应用,为鉴别损伤、疾病与正常死后变化提供参考。     

家兔限制性体位窒息模型中的LDH/CHE活性变化

目的 探讨家兔体位性窒息模型中乳酸脱氢酶(LDH)和胆碱脂酶(CHE)活性变化与窒息死亡的关系。方法 建立动物模型，检测膈肌、腓肠肌，以及血清中LDH、CHE的活性变化。结果 实验组家兔膈肌与腓肠肌相比，LDH活性明显下降，且差异显著(P＜0.05)，CHE活性差异无显著性(P＞0.05)；2组膈肌比较，LDH活性明显下降，有显著性差异(P＜0.05)，CHE活性无显著性差异(P＞0.05)；实验组血清中LDH活性比对照组明显升高，有显著性差异(P＜0.05)，2组CHE活性无显著性差异(P＞0.05)。结论 膈肌中LDH活性的降低与固定双上肢悬挂体位具有相关性。     

固定双上肢并悬挂家兔死亡机理的研究

目的观测固定双上肢并悬挂家兔的血气变化及膈肌的肌电变化,探讨体位性窒息死亡的发生机制。方法建立家兔体位性窒息死模型,在实验前、后分别抽取家兔耳缘动脉和左心室血2m l进行血气分析,并监测实验过程中家兔膈肌肌电图(EMGd i)的变化。结果实验组与对照组均有缺氧、二氧化碳储留以及氧饱和度下降,但是实验组的二氧化碳储留比对照组低,氧饱和度比对照组高,缺氧情况比对照组低。在连续记录的EMGd i中,早期EMGd i较晚期EMGd i的高频与低频(H/L)比值显著降低,超过20%。结论固定双上肢并悬挂家兔死亡与膈肌疲劳导致缺氧窒息有关     

扼死的特殊面容

<正> 扼死的判断,除必具明显窒息现象外,主要以颈前扼伤为根据。但工作实践中,我们遇到相当部分的扼死尸体,颈部扼伤(掐痕或甲痕)包括颈内部的损伤极不明显或很轻,以至很难认定为“伤”。鉴定时只能做出“窒息死亡”的结论。而难于判断为扼死。近些年来,我们在办案中发现扼死尸体颜面,多出现主要密集于两眼、两耳(或含耳前或耳后)以及两口     

窒息相关案件的死因纠错分析3例

导致死亡发生的疾病、暴力或衰老等因素即为死亡原因,简称"死因"。确定死因是法医病理学的首要任务,然而在法医实践中,死因鉴定错误时有发生[1],造成不良社会影响[2-3]。对于死因鉴定错误的案例,国内外以个案报道为主,缺乏对鉴定错误成因的系统分析。机械性窒息是法医实践中常见的死因,尸体征象表现为颜面部发绀、瘀点性出血和器官淤血等,称为窒息征象。其不具有特异性,不同尸体变化较大,与窒息相关的案例容易产生误判。本文选取某地经办的3例窒息相关死因鉴定前后不符的案件进行纠错分析,为避免死因鉴定错误提供参考。     

An unusual accidental death from positional asphyxia

Death from postural or positional asphyxia takes place in circumstances when the victim's body assumes an abnormal position compromising the process of respiration. The diagnosis is usually based on circumstantial evidence in conjunction with excluding other significant underlying causes of death. This case report is about a 37-year-old man who had been drinking the previous night and was found dead in the morning in a knee-chest position. The forensic medical examiner had the opportunity to examine and photograph the scene of death while the body was still in its original position. Apart from a blood alcohol level of 290 mg/100 mL, marked congestion of the face, and petechial hemorrhages on the conjunctivae, autopsy findings were unremarkable. There were no injuries or pathological findings to account for his death. Death was certified as due to postural asphyxia secondary to intoxication by alcohol.     

Causes and Mechanisms of Death in Fatal Water Buffalo Attacks

Deaths due to buffalo attack have not been well described. A 72‐year‐old man was trampled by a water buffalo (Bubalus bubalis) while attempting to move the animal within an enclosed area at an abattoir. At autopsy, there were numerous injuries involving the chest, head, neck, and left upper arm. Blunt force injury had resulted in multiple rib fractures with a flail chest and fracture/dislocation of the mid‐cervical vertebrae caused either by physical crushing by the animal against the walls of the enclosure or by stomping. There was also evidence of crush asphyxia with bilateral conjunctival hemorrhages and petechial hemorrhages. In addition, there was a deep degloving injury of the upper left arm compatible with goring by one of the buffalo horns. While large animal attacks may result in death from multiple injuries, careful dissection and examination of specific injuries at autopsy may clarify the complex interaction of lethal mechanisms.     

Sudden Death Secondary to an Undiagnosed B‐Cell Lymphoma of the Hypopharynx and Infiltration of the Inferior Constrictor Muscle

The aim of this presentation was to share an uncommon form of sudden death, suffered by a 64‐year‐old woman, due to a mechanical obstruction of hypopharynx by an undiagnosed B‐cell lymphoma, infiltrating the inferior pharyngeal constrictor muscle. A forensic approach by means of scene investigation, circumstantial data collection, autopsy, and histological and toxicological investigations led to conclude that the cause of death was asphyxia, correlated with B‐cell lymphoma of the hypopharynx. The autopsy examination highlighted the presence of a wall thickening, infiltrating, and projecting into the hypopharynx lumen. The histological analysis showed the essential finding of a B‐cell lymphoma of the hypopharynx, diffusely infiltrating the inferior pharyngeal constrictor muscle. To conclude, this case demonstrates once more that in the absence of specific data, a thorough forensic investigation including autopsy, histological examination, and circumstantial data collection is mandatory to reach a correct cause of death.     

Postmortem Computed Tomography in Firearm Homicides: A Retrospective Case Series,

Postmortem computed tomography (PMCT) is integrated into the evaluation of decedents in several American medical examiner offices and medicolegal death investigative centers in many other countries. We retrospectively investigated the value of PMCT in a series of firearm homicide cases from a statewide centralized medical examiner’s office that occurred during 2016. Autopsies were performed or supervised by board-certified forensic pathologists who reviewed the PMCT scans prior to autopsy. PMCT scans were re-evaluated by a forensic radiologist blinded to the autopsy findings and scored by body region (head–neck, thoracoabdominal, and extremities). Injury discrepancies were scored using a modified Goldman classification and analyzed with McNemar’s test. We included 60 males and 20 females (median age 31 years, range 3–73). Based on PMCT, 56 (79.1%) cases had injuries relevant to the cause of death in a single body region (24 head–neck region, 32 thoracoabdominal region). Out of these 56 cases, 9 had a missed major diagnosis by PMCT outside that region, including 6 extremity injuries visible during standard external examination. Yet all had evident lethal firearm injury. We showed that PMCT identifies major firearm injuries in homicide victims and excludes injuries related to the cause of death in other regions when a single body region is injured. Although PMCT has a known limited sensitivity for soft tissue and vascular pathology, it can be combined with external examination to potentially reduce or focus dissections in some of these cases depending on the circumstances and medicolegal needs.     

20例脂肪栓塞死亡的法医学分析

目的分析脂肪栓塞综合征（fatembolismsyndrome,FES）死亡的一般情况以及法医病理学特点,为此类案件的法医病理学鉴定提供参考。方法选取某大学法医学鉴定中心1999—2012年20例FES死亡案件．对其一般情况及法医病理学特点（包括致伤方式、损伤类型、临床表现、病理学改变等方面）进行总结。结果脂肪栓塞主要见于损伤导致的长骨骨折和全身大面积软组织损伤,主要类型为肺脂肪栓塞,偶见合并脑脂肪栓塞。症状多出现在伤后和术后较短时间内,组织病理学检查可在肺小血管内检见大量脂滴并经特殊染色证实。结论FES死亡案例在损伤类型、脂肪栓塞出现症状时间及组织病理学表现等方面均有一定规律和特点。在鉴定中应注意进行特殊染色（油红0染色）处理,寻找FES的直接证据。     

An elliptical incised wound of the breast misinterpreted as a bite injury

Bite injuries upon homicide victims are most often initially identified by the forensic pathologist during the course of the autopsy examination. Following such recognition, the injury or photographs of the traumatized site are then referred to a forensic odontologist for his or her examination, further characterization, and subsequent comparison with any suspect's dentition. However, if the pathologist misidentifies an injury caused by another mechanism as a human bite, this mistake can potentially be perpetuated by the dental consultant, since relatively few dentists regularly examine traumatic injuries other than those arising from bites. To illustrate such an event, a case is presented involving an incised wound of the breast, which was originally identified as an avulsive bite wound. Detailed examination by two odontologic consultants confirmed the wound as having been caused by human teeth, and further, they related the "bite injury" to a specific individual. The bite injury interpretation represented the only scientific evidence implicating the suspect at a subsequent trial for capital murder. Later examination of the tissues and photographs by a forensic pathologist and another dental consultant revealed that the injury was not due to human dentition, but rather resulted from a sharp-edged instrument. These consultants conducted a unique experiment to reduplicate the injury and prove its causation. This information was presented to the jury during the suspect's trial and resulted in his acquittal on all charges.     

颈内动脉系钝性损伤法医学鉴定现状

颈内动脉系是大脑的主要血供来源。法医学鉴定实践中,颈内动脉系钝性损伤后常出现血栓、动脉瘤或动静脉瘘等并发症,由此引起迟发性脑梗死、颅内出血死亡的案例并不少见。目前国内对颈内动脉系钝性损伤引起死亡的研究以个案报道为主,本文综合国内外相关的文献及案例报道,对此类损伤引起死亡的法医学特点及检查方法进行总结,发现颈内动脉系钝性损伤与头颈部直接暴力或间接暴力致头颈部超生理范围运动牵拉,以及颅底骨折切割等机制有关,多见于颈部机械性窒息、颈部按摩、车祸、高坠等案例。法医学实践中若遇到此类案例,常规检查未发现梗死或出血原因,应注意检查该动脉,正确分析外伤、疾病和死亡之间的关系。鉴于尸体解剖中完整暴露该动脉的难度较大,必要时可借助血管造影技术进行定位,提高鉴定意见的科学性和可靠性。     

监管场所25例非正常死亡的法医学分析

目的通过对监管场所非正常死亡案例进行筛选、收集,分析其影响因素及法医学特点。方法收集某鉴定中心2000—2015年间受理的监管场所在押人员非正常死亡案例25例,从性别、年龄、历年发案数、死亡原因、死亡方式等方面分析其特征,并对公安类监管场所和监狱类场所的案件性质进行对比。结果涉案死者均为男性,中青年人群为高危人群,历年发案数量呈逐年下降趋势。公安类监管场所的伤害案件发生率(64.7%)大于监狱类场所(12.5%),而监狱类场所的自杀率(62.5%)高于公安类(23.5%)。死亡原因以损伤和窒息为主,其他还有中毒和电击等。结论监管场所非正常死亡案件暴露出执法不规范、监管有漏洞、医疗水平差等问题。进行全面、细致的尸体解剖对于查明此类案件的死因有重要意义。