The Interest of Postmortem Bacteriology in Putrefied Bodies

A 27‐year‐old man was found dead in an advanced decomposition stage at home. On external examination, his body showed petechial hemorrhages of the skin. At autopsy, petechial hemorrhages of the epicardium were found, but no sign of meningitis was detected. Toxicological investigations remained negative. Bacteriological conventional analyses showed no significant result. Neisseria meningitidis serogroup B was finally isolated on cerebrospinal fluid by a specific real‐time polymerase chain reaction. To our knowledge, there are no available data about the postmortem diagnosis of an infectious cause of death in a decomposed corpse. In such situations, the polymicrobial overgrowth usually hampers the interpretation of bacteriological conventional methods and questions their diagnostic value. Such molecular bacteriological approaches appear to constitute an important diagnostic tool for forensic scientists and should be widely processed in case of suspected infectious death or sudden death whatever the postmortem interval.     

Are Peripapillary Intrascleral Hemorrhages Pathognomonic for Abusive Head Trauma?*

Abstract: The American Academy of Pediatrics’ Committee on Child Abuse and Neglect, Section on Ophthalmology, acknowledges that searching for retinal hemorrhages (RHs) in infants only in cases of suspected of abuse creates selection bias. However, they also recommend that postmortem eye removal might not be indicated “in children who have clearly died from witnessed severe accidental head trauma or otherwise readily diagnosed systemic medical conditions.” Although infrequently described in the child abuse literature, peripapillary intrascleral hemorrhages (bleeding in the sclera at the optic nerve insertion)—putatively from severe repetitive acceleration/deceleration forces with or without blunt head trauma—have been considered essentially pathognomonic for abusive head trauma (shaken baby syndrome). We present two neonates who sustained accidental, severe in utero head injuries and had associated extensive RHs and optic nerve sheath hemorrhages with peripapillary intrascleral hemorrhages detected at autopsy. Neither neonate had a documented clinical fundal examination in the intensive care unit.     

Postmortem Skeletal Survey Practice in Pediatric Forensic Autopsies: A National Survey*

Abstract: Recommendations for the evaluation of an unexplained death in infancy include a postmortem skeletal survey (PMSS) to exclude skeletal trauma. Objectives of this study were to assess adherence to these recommendations in forensic autopsies in children equal to or less than 36 months of age, and what factors influence the use or nonuse of the PMSS. We surveyed pathologists who were members of the American Academy of Forensic Sciences. The survey included practice characteristics about where, when, and how PMSS were done. Nearly all respondents (99.6%) indicated they performed PMSS at least some of the time; however, almost a third did not use PMSS for all suspected Sudden Infant Death Syndrome (SIDS), abuse, unsafe sleep, or undetermined causes of death. Despite evidence that “babygrams” are inappropriate in a SIDS workup, 30% of pathologists use them preferentially. Despite SIDS being a diagnosis of exclusion that requires a PMSS, almost 10% of pathologists do not order a PMSS. Future research is necessary to reduce barriers to this important component of the pediatric forensic autopsy.     

死亡大鼠看家基因mRNA时序性降解的组织差异性研究

目的研究死亡大鼠看家基因mRNA时序性降解的组织差异性,评价其用于死亡时间推断的价值。方法SD大鼠20只分为死后0、1、3、5、7d共5组,脊椎脱臼法处死大鼠,提取大鼠心、肝、脾、肺、肾、脑组织,在相应时间段提取RNA,应用一步法RT-PCR技术检测各组织中看家基因GAPDHmRNA和β-actinmRNA的水平,Vilber凝胶图像分析系统测定扩增产物IOD值,SPSS10．0统计软件对数据进行方差分析。结果GAPDHmRNA、β—actinmRNA扩增产物相对灰度与积分光密度值随死后经过时间的延长而逐渐减小,且与死亡时间显著相关,大鼠脾脏和脑组织GAPDHmRNA和β-actinmRNA在死后5d内可检出,心脏和肾脏在死后3d内可检出,而肝脏和肺脏GAPDHmRNA和β-actin mRNA降解较快,仅在死后1d内可检出。结论脑组织和脾脏中mRNA稳定性较好,适用于PMI特别是晚期PMI的推断。除环境温度外,环境湿度也是死亡时间推断中的重要影响因素。     

大鼠皮肤切创后E-选择素表达及稳定性研究

目的探讨大鼠皮肤切创后E-选择素表达规律及法医学意义。方法健康SD大鼠90只,随机分成4组：正常对照组、活体切创组（30min～7d12个时间点）、死后切创组（30min～3h3个时间点）、死后稳定性组（-20％6h-7d9个时间点,25％6h～3d5个时间点）。在大鼠头部建立皮肤切创模型,按设定的时间点取皮肤检材,运用免疫组化和图像分析技术,检测血管内皮E-选择素的表达规律。结果在活体切创组中,伤后1hE-选择素在血管内皮细胞内即呈阳性表达,持续至伤后7d,且随时间变化呈规律性表达。在正常对照及死后切创组未见阳性表达。死后-20％稳定性组各时间点E-选择素表达与死后即刻比较无显著性差异（P〉0．05）。25％各时间点与死后即刻比较有显著性差异（P〈0．01）。结论E-选择素在创伤后血管内皮细胞内特异性的表达具有时序性规律,且低温条件下稳定性较好。     

玻璃体液化学成分规律性改变与死亡时间推断的研究进展

死亡时间（postmortem interval．PMI）的准确推断是法医尸体检验工作中的难题之一,PMI推断对刑事案件的侦察和审判具有重要的意义。人死亡后不同时间眼玻璃体液化学成分的规律性变化,如钾、镁、氨、尿素氮、肌酐和尿酸、次黄嘌呤、乳酸的含量逐渐升高,而钙、钠、酶类、葡萄糖、维生素C的含量逐渐降低,有助于比较准确地进行PMI推断。本文对其在法医学领域的研究进展进行综述。     

实时RT-PCR检测大鼠死后管家基因mRNA的时序性降解

目的研究实时荧光定量RT—PCR方法检测死亡大鼠管家基因mRNA时序性降解的可行性,为死亡时间（Dostmortem interval,PMI）推断寻找新的研究手段。方法应用SYBR Green Ⅰ实时荧光定量RT—PCR技术．检测死后不同时间大鼠脑和脾中管家基因GAPDHmRNA及β—actinmRNA的水平,结果用循环阈值（简称Ct值）表示,分析死后经过时间与Ct值的线性关系,并建立死亡时间推断回归方程。结果GAPDH mRNA和β—actinmRNA的Ct值均与PMI之间存在显著的相关性。结论SYBR GreenⅠ实时荧光定量RT—PCR在定量分析mRNA降解的研究中是一个较理想的技术手段。选用管家基因作为PMI推断的研究对象,可在法医检案中消除其他基因因为个体差异带来的误差,更具实用性。Ct值作为动态监测机体死后不同时间点的客观指标．与死后不同时间点的线性关系良好,推断死后经过时间尤其是晚期死亡时间较为理想。     

The black soldier-fly, Hermetia illucens (Diptera, Stratiomyidae), used to estimate the postmortem interval in a case in Amapá State, Brazil

The black soldier-fly (Hermetia illucens) is a generalist detritivore which is commonly present in corpses in later stages of decomposition and may be useful in forensic entomology. This paper describes the estimation of the postmortem interval (PMI) based on the life cycle of the black soldier-fly in a case in northern Brazil. A male child was abducted from his home and 42 days later his corpse was found in an advanced stage of decay. Two black soldier-fly larvae were found associated with the body. The larvae emerged as adults after 25-26 days. Considering the development cycle of H. illucens, the date of oviposition was estimated as 24-25 days after abduction. Since H. illucens usually (but not always) colonizes corpses in more advanced stages of decay, this estimate is consistent with the hypothesis that the child was killed immediately after abduction.     

Diesel fumes do kill: a case of fatal carbon monoxide poisoning directly attributed to diesel fuel exhaust with a 10-year retrospective case and literature review*

While it is known that diesel fuel combustion engines produce much lower concentrations of carbon monoxide (CO) than gasoline engines, these emissions could certainly generate lethal ambient concentrations given a sufficient amount of time in an enclosed space and under suitable environmental conditions. The authors report a case of CO poisoning which was initially referred for autopsy as a presumed natural death of a truck driver found in the secure cab of a running diesel tractor trailer truck. Completion of the preliminary investigation ascribed death to complications of ischemic heart disease (IHD), pending toxicological analysis that included quantification of CO. When the toxicology results showed lethal blood COHbg, the cause of death was re-certified as CO intoxication secondary to inhalation of (diesel) vehicular exhaust fumes. Because of the unique source of fatal CO intoxication in this case, the contributory IHD and the possible contaminants in the putrefied blood, a 10-year retrospective review was conducted on all nonfire related CO deaths autopsied (n = 94) at the Office of the Chief Medical Examiner in Louisville, KY from 1994 to 2003. For validation of the COHbg detection method used by the Kentucky Office of Forensic Toxicology (KYOFT), blood samples from these cases along with controls were submitted to three laboratories using various analytical methods yielding no statistically significant differences. Lastly, an extensive literature review produced no scientifically reported cases of fatal CO poisoning attributed to diesel fuel exhaust.     

Elevated morphine concentrations determined during infant death investigations: artifacts of withdrawal of care

Abstract:  Three cases are reported of elevated postmortem blood morphine concentrations (189–3036 ng/mL) that were observed during the course of death investigations involving three children ranging in age from 1 week to 2 years, all of whom underwent withdrawal of life support. In all three cases, the presence of opiates in postmortem blood was indicated by immunoassay (ELISA) and quantitative confirmatory analysis of free morphine concentrations in postmortem blood was performed by solid-phase extraction followed by gas chromatography/mass spectrometry (GC/MS) in the selected ion monitoring mode. While the practice of withdrawing life support from terminally ill patients, with the accompanying administration of narcotics/analgesics has been reported in the medical literature, it has not been adequately described in the forensic literature. The implications of this practice on the forensic toxicological interpretation of morphine findings are discussed. To our knowledge, this is the first report of postmortem morphine concentrations arising directly from administration in conjunction with withdrawal of care in pediatric patients.