尸检样本乙醇分析结果的解释策略

由于死后各种复杂的人为现象的存在，使得建立死后血液酒精含量（BAC）和死亡时醉酒状态之间的关系十分困难。在日常检案中必须考虑细菌污染、发酵是否引起死后乙醇再合成．死亡时胃中未被吸收的乙醇是否向周围组织以及血中扩散等问题。本文总结了关于死后乙醇分析及结果解释相关问题的研究文献，旨在为从事法医毒物学乙醇分析的同行在调查此类案件时提供良好的开端。     

尸体血液中乙醇质量浓度的分析评价

血液中乙醇质量浓度是分析评价机体内乙醇水平的重要证据,由于尸体内检测到乙醇可能受死后生成、乙醇扩散等因素影响,尸体血液中乙醇质量浓度检测结果未必能反映其死亡时机体内乙醇的真实水平。鉴别尸体内乙醇是否为原始浓度是分析评价的关键。本文对乙醇在体内的分布特点、如何合理取材及死后乙醇扩散、尸体腐败产生的乙醇对乙醇质量浓度分析的影响进行了综述,并对死后乙醇质量浓度检测的分析评价策略进行了讨论。     

大鼠死后肋软骨细胞核DNA含量随死亡时间的变化

目的研究大鼠死后肋软骨细胞核DNA含量与晚期死亡时间的相关性。方法应用改良的Feu lgen法结合计算机图像分析技术对死后大鼠35d内肋软骨细胞核DNA含量变化进行观测分析。结果死后1~28d,细胞核染色逐渐变淡,至35d时已观察不到,死后肋软骨细胞核DNA含量与死亡时间呈直线相关。结论大鼠肋软骨细胞核DNA含量随死亡时间延长呈线性规律下降。     

死后人工生殖之禁制与开放——以德国及台湾地区的裁判为中心

死后人工生殖的禁制与开放，是一个法律疑难问题。德国法上的规范重点在胚胎保护，而非人工生殖技术之管制。在新布兰登堡案中，原告之卵子与其夫之精子已于其夫尚未死亡前即已完成精卵结合，故不在《胚胎保护法》禁止之列。但死后人工生殖，尚待有效管制。我国台湾地区关于死后人工生殖之争议，源起于死者家属死后取精的要求，其首要问题在于死者是否有事前同意。立法机构讨论认为，只有在具备受术夫妻的事前同意，并于配偶一方死亡后设一定期间之犹豫期的条件下，方可有条件地开放死后人工生殖。人工生殖禁制与开放的抉择，应综合考虑和审慎权衡生存配偶的生育权、死亡配偶的同意权和人工生殖子女之利益等。     

丽蝇生长发育与死亡时间的相关研究

目的探讨丽蝇的生长发育与死亡时间的关系。方法在室外自然条件情况下,观察尸体腐败过程中来蝇时间,蝇的群集时间,产卵时间,蝇蛆的生长情况及成蛹、羽化时间,并联系气候因素收集数据,进行统计分析。结果来蝇时间发生在死后0.2h,死后28h苍蝇群集,在44h时发现虫卵,幼虫孵出时间为死后60h,入土化蛹时间为死后112h,羽化时间为248h。结论在尸体上观察丽蝇的生长发育不同的时间节点可用于推断死亡时间。     

DNA降解与腐败尸体死亡时间的相关性

目的探讨骨髓细胞核DNA含量变化与腐败尸体死亡时间的关系。方法应用DNA高度特异性染色方法Feulgen改良法结合计算机图像分析技术对死后不同时间(0～14d)胸骨骨髓细胞核DNA含量变化进行分析。结果胸骨骨髓细胞核DNA含量随死亡时间延长呈缓慢而规律下降,直至死后两周仍未完全降解。结论死后DNA降解速率与死亡时间呈线性关系,测定死后骨髓细胞核DNA含量可望成为腐败尸体死亡时间推断的新方法。     

大鼠死后不同时间坐骨神经雪旺氏细胞核DNA的变化

目的探讨大鼠死后不同时间坐骨神经雪旺氏细胞核DNA的变化及其与死亡时间的关系。方法应用Feulgen染色法及计算机图像分析技术,观测大鼠死后即刻至9d坐骨神经雪旺氏细胞核DNA染色变化及其图像分析参数,所得数据进行统计学分析。结果雪旺氏细胞核在死后6-18h细胞核呈紫红色、长椭圆形,轮廓清晰,其长轴方向与坐骨神经走向一致,死后24h着色变淡、着色面积变小,最终完全消失;在6h-9d内目标面积和积分光密度随死亡时间的延长而逐渐减小,且其均值均与死亡时间明显相关,并得出对应的回归方程。结论大鼠死后9d内,其坐骨神经雪旺氏细胞核DNA变化与死亡时间有一定的相关性。     

小鼠骨骼肌细胞核DNA降解与死亡时间的关系

目的　监测小鼠死后骨骼肌核内DNA降解的情况 ,探讨死后细胞核DNA降解的一般规律。方法　建立小鼠死亡模型 ,在死后 72h内 ,以 12h的间隔取骨骼肌样本进行单细胞凝胶电泳 ,在荧光显微镜下测量彗星图像 ,并作统计学分析。结果　机体死后 ,骨骼肌细胞在电泳图像上出现了明显的彗星形拖尾 ,L/W比值随死亡时间而逐渐增大 ,二者呈一定的线性关系。结论　单细胞凝胶电泳技术可以应用于早期死亡时间推断。     

死者生前人格利益的保护

学界对于自然人死后是否还有人格权,一直存在争议.本文从几个典型案例入手,对这种情况作了分析,认为自然人死亡后,无论是权利还是利益都已经消灭,但是从死者近亲属角度,应当予以保护。     

血、尿中乙醇含量的测定及其评价——Ⅲ. 乙醇的死后生成及其血、尿样品中乙醇浓度变化

动物实验和实际案例分析结果表明,尸体低温保存较长时间,或室温保存数天,血尿中可生成乙醇正丙醇等,乙醇量一般为正丙醇的20倍内.另一组实验考察了血、尿样品保存时乙醇的稳定性.在评价乙醇含量,判断是否生前饮酒时需考虑这些因素对乙醇含量的影响.     

Interpreting results of ethanol analysis in postmortem specimens: a review of the literature

We searched the scientific literature for articles dealing with postmortem aspects of ethanol and problems associated with making a correct interpretation of the results. A person's blood-alcohol concentration (BAC) and state of inebriation at the time of death is not always easy to establish owing to various postmortem artifacts. The possibility of alcohol being produced in the body after death, e.g. via microbial contamination and fermentation is a recurring issue in routine casework. If ethanol remains unabsorbed in the stomach at the time of death, this raises the possibility of continued local diffusion into surrounding tissues and central blood after death. Skull trauma often renders a person unconscious for several hours before death, during which time the BAC continues to decrease owing to metabolism in the liver. Under these circumstances blood from an intracerebral or subdural clot is a useful specimen for determination of ethanol. Bodies recovered from water are particular problematic to deal with owing to possible dilution of body fluids, decomposition, and enhanced risk of microbial synthesis of ethanol. The relationship between blood and urine-ethanol concentrations has been extensively investigated in autopsy specimens and the urine/blood concentration ratio might give a clue about the stage of alcohol absorption and distribution at the time of death. Owing to extensive abdominal trauma in aviation disasters (e.g. rupture of the viscera), interpretation of BAC in autopsy specimens from the pilot and crew is highly contentious and great care is needed to reach valid conclusions. Vitreous humor is strongly recommended as a body fluid for determination of ethanol in postmortem toxicology to help establish whether the deceased had consumed ethanol before death. Less common autopsy specimens submitted for analysis include bile, bone marrow, brain, testicle, muscle tissue, liver, synovial and cerebrospinal fluids. Some investigators recommend measuring the water content of autopsy blood and if necessary correcting the concentration of ethanol to a mean value of 80% w/w, which corresponds to fresh whole blood. Alcoholics often die at home with zero or low BAC and nothing more remarkable at autopsy than a fatty liver. Increasing evidence suggests that such deaths might be caused by a pronounced ketoacidosis. Recent research has focused on developing various biochemical tests or markers of postmortem synthesis of ethanol. These include the urinary metabolites of serotonin and non-oxidative metabolites of ethanol, such as ethyl glucuronide, phosphatidylethanol and fatty acid ethyl esters. This literature review will hopefully be a good starting point for those who are contemplating a fresh investigation into some aspect of postmortem alcohol analysis and toxicology.     

Ethanol production by Candida albicans in postmortem human blood samples: effects of blood glucose level and dilution

We present two cases in which the ethanol concentration in blood samples taken after death continued to increase in the absence of any remarkable increase in n-propanol concentration. Species of bacteria and yeasts, including Candida albicans were isolated from these samples. We then examined whether C. albicans, the most common yeast in the general environment, was able to produce ethanol in human blood stored at room temperature. Ethanol production increased as the glucose concentration increased, indicating that C. albicans produced ethanol from the glucose. Our results also suggested that C. albicans produced ethanol more easily in blood diluted by intravenous infusions that included glucose than in undiluted blood. These findings are useful for the evaluation of postmortem ethanol production in subjects whose blood has been diluted by infusions with glucose. Furthermore, there was no quantitative relationship between the amount of n-propanol detected and the amount of ethanol production: n-propanol appears to be an unreliable index of putrefaction and postmortem ethanol production by C. albicans. It is possible for the blood ethanol level to be high and n-propanol not to be detected, even if the subject has not been drinking alcohol. We reconfirmed the necessity of immediately adding sodium fluoride to samples for ethanol analysis to prevent postmortem ethanol production.     

Abnormally high alcohol concentration in the heart blood

A 46-year-old male alcoholic whose whereabouts had been unknown for about a month was found dead at the foot of a cliff 31 m deep. Fractures of the mandible, thorax and left patella were found at autopsy, but fatal injury to the brain or other organs was not observed. The alcohol distribution was 7.44 mg/g in the heart blood, 13.91 mg/g in the left thoracic cavity fluid and 1.88 mg/g in the urine. The high ethanol concentration in the heart blood was assumed to be mainly due to the diffusion of ethanol from the contents of the stomach and postmortem production of ethanol. It was decided that the cause of death was not acute alcohol intoxication but respiratory failure caused by fractures of the thorax.     

The role of trauma in postmortem blood alcohol determination

In postmortem cases, a blood sample is frequently obtained by transthoracic (TT) puncture. The purpose of this study was to determine if, in traumatic death, blood samples collected by TT provided a valid sample for blood alcohol analysis. A retrospective study (1980–1986) was conducted to evaluate possible contamination of blood by GI alcohol in traumatic death cases. Out of 6000 cases reviewed, 19 cses with BACs >500 mg/dl were found and 8 of these cases involved traumatic death with GI laceration and/or transection. The results of this study support the hypothesis that blood samples from the 8 cases had been contaminated, resulting in a falsely elevated BAC. A transthoracic study (1987–1989) was conducted under controlled conditions, where blood alcohol content of TT blood samples was compared with samples collected from the intact heart chamber. Seven out of 28 cases of traumatic injury revealed trauma to the GI tract. The results showed that when GI traumatic injury occurs and unabsorbed ethanol is present in the stomach, contamination of TT blood samples occurs and artificially elevated BACs are obtained. It is recommended that, in cases of traumatic injury, heart blood samples from the intact heart chamber, as well as samples of additional biological fluids, be collected to rule out the possibility of contamination and to ensure that the BAC used for forensic interpretation is accurate.     

Postmortem blood and vitreous humor ethanol concentrations in a victim of a fatal motor vehicle crash

A 20-year-old male was found on the passenger side of a small car after a collision with a semi-trailer truck. Postmortem blood, collected from the chest cavity, and vitreous humor samples were collected following harvesting of the heart and bones. Gas chromatographic analysis revealed a blood ethanol concentration of 0.32 g/dL and a vitreous humor ethanol concentration of 0.09 g/dL. The stomach was intact and full of fluid and food, but its contents were not collected. Possible explanations for the large difference between the two results include diffusion of ethanol from the stomach into the chest cavity, contamination of the blood sample prior to collection, and ingestion of a large quantity of ethanol shortly before death. This case demonstrates the importance of proper quality assurance procedures in collecting postmortem specimens and of collecting a vitreous humor sample for ethanol analysis in postmortem toxicology cases.     

Homicidal alcoholic intoxation versus manual neck compression

A case of homicide involving a 49-year-old man is reported. In the course of a booze-up he was forced to excessive consumption of alcohol and was pushed back into a sofa by repeated grasping his neck which finally left him dead. The postmortem examination revealed a small abrasion in the right mandibular region, a contusion of the subcutaneous tissue above the left clavicle, a haemorrhage in the deep muscles of the neck at the right side of the cervical spine, a fatty tissue haemorrhage between the left cornus of hyoid and thyroid cartilage as well as petechiae of the eyelids and conjunctivae. The blood alcohol concentration amounted to 4.00@1000, the urine alcohol concentration to 5.26@1000. Thus, a manual strangulation of the neck versus a lethal alcohol intoxication had to be taken into consideration as cause of death. The morphological findings of the postmortem examination and the pathophysiological concepts of the underlying mechanisms of death in manual strangulation versus lethal alcohol intoxication are discussed with regard to their significance for the juridical assessment.     

Postmortem transport of gastric contents?

For the determination of the time since death, the distribution of the last meal in the stomach and small bowel may be of great importance. It may be even more difficult to estimate the time if there is a possibility that postmortem peristaltic emptying of the gastric content occurs, as has been claimed. Radiological control immediately after death by means of applying barium sulfate to the stomach, however, revealed no evidence of peristaltic emptying of the gastric content after death.     

Interleukin-6 and C-reactive protein serum levels in sepsis-related fatalities during the early postmortem period

Postmortem interleukin-6 (IL-6) and C-reactive protein (CRP) serum levels were investigated prospectively in sepsis-related fatalities and non-septic fatalities by using a linear regression model. At least three blood samples were collected between 0.3 and 139 h postmortem from sepsis-related fatalities (n=8) and non-septic fatalities (n=16). In addition, one antemortem blood sample was collected shortly before death from the septic patients. Antemortem and postmortem IL-6 and CRP levels were highly elevated in all individuals included in the sepsis group. An excessive postmortem increase of IL-6 serum levels associated with progressive time after death was observed in five out of the eight septic patients. Both, IL-6 and CRP serum concentrations seem to be suitable biochemical postmortem markers of sepsis. The determination of IL-6 serum levels above 1500 pg/ml in peripheral venous blood obtained in the early postmortem interval can be considered as a diagnostic hint towards an underlying septic condition. A more precise postmortem discrimination between sepsis and non-septic underlying causes of death is provided by the postmortem measurement of serum CRP in peripheral venous blood: on condition that at least two postmortem CRP values have been determined at different time points postmortem, the CRP level of a deceased at the time of death can be calculated by using linear regression analysis. When assessing postmortem IL-6 and CRP concentrations as biochemical postmortem markers of sepsis, various clinical conditions, such as a preceding trauma or burn injury going along with elevated IL-6 and/or CRP levels prior to death as a result of the systemic inflammatory response syndrome (SIRS) should be taken into consideration, thus adding relevant information for the practical interpretation of the results.     

Assessment of the Role Played by N‐propanol Found in Postmortem Blood in the Discrimination Between Antemortem Consumption and Postmortem Formation of Ethanol Using Rats

This study disproves the reliability of n‐propanol as a biomarker to establish whether the ethanol found in postmortem blood is derived from antemortem ingestion or postmortem putrefactive processes. Two groups of rats were given ethanol or normal saline solution, respectively, and sacrificed 1.5 h later. After putrefaction, blood and, in a few cases, urine samples from the rats were analyzed for ethanol and n‐propanol by head‐space gas chromatography equipped with flame ionization detection. Although the concentration ratios of ethanol/n‐propanol in the postmortem blood collected from the bodies without prior alcohol consumption were expected to be <20 (as per limited case reports and previous in vitro studies), in samples from several rats that were on saline solution, this ratio was found to exceed 20. In conclusion, the concentration ratio of ethanol/n‐propanol in postmortem blood does not allow for the discernment between antemortem ingestion and the postmortem synthesis of ethanol.