Deaths among narcotic addicts in Denmark in 1978 and 1979

Objective measurements were carried out to study the evolution of rigor mortis on rats at various temperatures.Our experiments showed that:(1) at 6 °C rigor mortis reaches full development between 48 and 60 hours post mortem, and is resolved at 168 hours post mortem; (2) at 24 °C rigor mortis reaches full development at 5 hours post mortem, and is resolved at 16 hours post mortem; (3) at 37 °C rigor mortis reaches full development at 3 hours post mortem, and is resolved at 6 hours post mortem; (4) the intensity of rigor mortis grows with increase in temperature (difference between values obtained at 24 °C and 37 °C); and (5) at 6 °C a “cold rigidity” was found, in addition to and independent of rigor mortis.     

Experimental evaluation of rigor mortis. VII. Effect of ante- and post-mortem electrocution on the evolution of rigor mortis

The influence of electrocution on the evolution of rigor mortis was studied on rats. Our experiments showed that: (1) Electrocution hastens the onset of rigor mortis. After an electrocution of 90 s, a complete rigor develops already 1 h post-mortem (p.m.) compared to 5 h p.m. for the controls. (2) Electrocution hastens the passing of rigor mortis. After an electrocution of 90 s, the first significant decrease occurs at 3 h p.m. (8 h p.m. in the controls). (3) These modifications in rigor mortis evolution are less pronounced in the limbs not directly touched by the electric current. (4) In case of post-mortem electrocution, the changes are slightly less pronounced, the resistance is higher and the absorbed energy is lower as compared with the ante-mortem electrocution cases. The results are completed by two practical observations on human electrocution cases.     

Long persistence of rigor mortis at constant low temperature

We studied the persistence of rigor mortis by using physical manipulation. We tested the mobility of the knee on 146 corpses kept under refrigeration at Torino's city mortuary at a constant temperature of +4 degrees C. We found a persistence of complete rigor lasting for 10 days in all the cadavers we kept under observation; and in one case, rigor lasted for 16 days. Between the 11th and the 17th days, a progressively increasing number of corpses showed a change from complete into partial rigor (characterized by partial bending of the articulation). After the 17th day, all the remaining corpses showed partial rigor and in the two cadavers that were kept under observation "à outrance" we found the absolute resolution of rigor mortis occurred on the 28th day. Our results prove that it is possible to find a persistence of rigor mortis that is much longer than the expected when environmental conditions resemble average outdoor winter temperatures in temperate zones. Therefore, this datum must be considered when a corpse is found in those environmental conditions so that when estimating the time of death, we are not misled by the long persistence of rigor mortis.     

常规冷冻对大鼠尸体组织形态学的影响

目的观察分析死后不同时间冷冻大鼠尸体主要内脏组织细胞形态变化规律。方法 SD大鼠20只,分为尸僵前冷冻组、尸僵期冷冻组、尸僵缓解冷冻组及对照组（各5只）,颈椎脱臼处死大鼠,实验组大鼠在室温25℃±5℃、相对湿度80%±5%分别放置0h、6h、24h后-20℃±2℃冰箱冷冻72h,解剖提取脑、心、肺、肝、肾,常规切片HE染色,显微图像体视学测量细胞外间隙的面密度。结果各实验组内脏组织间质疏松增宽,冰晶裂隙沿组织间隙或肝血窦分布、周边细胞固缩,红细胞冻溶、血管周围浆液淤积,以肝组织变化最明显。细胞外间隙的面密度：对照组明显小于实验组（P〈0.01）;脑尸僵前组较尸僵组大（P〈0.05）;心、肾尸僵前组和尸僵组无显著差异（P〉0.05）,均较尸僵缓解组大（P〈0.01）;肝各实验组组间比较均无显著差异（P〉0.05）。结论冷冻不同尸僵状态下内脏组织细胞有不同的形态结构,可作为区别和判断生前和死后组织细胞形态改变的参考。     

Differential rigor development in red and white muscle revealed by simultaneous measurement of tension and stiffness

Based on the molecular mechanism of rigor mortis, we have proposed that stiffness (elastic modulus evaluated with tension response against minute length perturbations) can be a suitable index of post-mortem rigidity in skeletal muscle. To trace the developmental process of rigor mortis, we measured stiffness and tension in both red and white rat skeletal muscle kept in liquid paraffin at 37 and 25 degrees C. White muscle (in which type IIB fibres predominate) developed stiffness and tension significantly more slowly than red muscle, except for soleus red muscle at 25 degrees C, which showed disproportionately slow rigor development. In each of the examined muscles, stiffness and tension developed more slowly at 25 degrees C than at 37 degrees C. In each specimen, tension always reached its maximum level earlier than stiffness, and then decreased more rapidly and markedly than stiffness. These phenomena may account for the sequential progress of rigor mortis in human cadavers.     

Estimation of the breaking of rigor mortis by myotonometry

Myotonometry was used to detect breaking of rigor mortis. The myotonometer is a new instrument which measures the decaying oscillations of a muscle after a brief mechanical impact. The method gives two numerical parameters for rigor mortis, namely the period and decrement of the oscillations, both of which depend on the time period elapsed after death. In the case of breaking the rigor mortis by muscle lengthening, both the oscillation period and decrement decreased, whereas, shortening the muscle caused the opposite changes. Fourteen h after breaking the stiffness characteristics of the right and left m. biceps brachii, or oscillation periods, were assimilated. However, the values for decrement of the muscle, reflecting the dissipation of mechanical energy, maintained their differences.     

Development of rigor mortis is not affected by muscle volume

There is a hypothesis suggesting that rigor mortis progresses more rapidly in small muscles than in large muscles. We measured rigor mortis as tension determined isometrically in rat musculus erector spinae that had been cut into muscle bundles of various volumes. The muscle volume did not influence either the progress or the resolution of rigor mortis, which contradicts the hypothesis. Differences in pre-rigor load on the muscles influenced the onset and resolution of rigor mortis in a few pairs of samples, but did not influence the time taken for rigor mortis to reach its full extent after death. Moreover, the progress of rigor mortis in this muscle was biphasic; this may reflect the early rigor of red muscle fibres and the late rigor of white muscle fibres.     

博落回对大鼠心肌Ca2＋.Mg2＋-ATPase与SDH活性的影响及超微结构观察

目的探讨博落回对心肌作用的机制。方法SD大鼠36只分为2个实验组和1个对照组,每组12只;2个实验组分别按1/6LD50、1/3LD50剂量的博落回水煎液灌胃,对照组以蒸馏水灌胃。各组大鼠处死后,每组10只取心肌组织制成匀浆,检测Ca2＋.Mg2＋-ATPase与SDH（琥珀酸脱氢酶）的活性;另2只大鼠心肌行超微结构观察。结果1/6LD50组大鼠心肌内Ca2＋.Mg2＋-ATPase与SDH活性较对照组有显著性升高（P〈0.05）;1/3 LD50组大鼠心肌内Ca2＋.Mg2＋-ATPase与SDH活性同对照组比较无显著性差异（P〉0.05）,但呈下降趋势。超微结构观察到实验组大鼠心肌细胞发生凋亡及1/3 LD50组大鼠出现心肌排列紊乱、断裂等征象。结论博落回对大鼠心肌内Ca2＋.Mg2＋-ATPase与SDH的活性有影响作用,并能诱导心肌细胞凋亡。     

Determination of Adenosine Phosphates in Rat Gastrocnemius at Various Postmortem Intervals Using High Performance Liquid Chromatography

Abstract: Although the change in adenosine phosphate levels in muscles may contribute to the development of rigor mortis, the relationship between their levels and the onset and development of rigor mortis has not been well elucidated. In the current study, levels of the adenosine phosphates including adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) in gastrocnemius at various postmortem intervals of 180 rats from different death modes were detected by high performance liquid chromatography. The results showed that the levels of ATP and ADP significantly decreased along with the postmortem period of rats from different death mode whereas the AMP level remained the same. In addition, it was found that changes in the ATP levels in muscles after death correlated well with the development of rigor mortis. Therefore, the ATP level could serve as a reference parameter for the deduction of rigor mortis in forensic science.     

大鼠尸僵发展过程中肌节长度的变化及其长度测定

目的观察大鼠尸僵发展过程中肌节形态、肌节长度的变化。方法 2 1只大鼠分为 3组 ,每组大鼠分别于死后立即和死后 2h、 4h、 6h、 8h、 12h、 2 4h取材 ,扫描电镜下观察大鼠死后不同时间的肌节形态 ,同时测定肌节长度。结果死后立即取材标本肌原纤维松散 ,纤维间有一定的间隙 ;死后 2h ,肌原纤维间界限模糊 ,出现周期性横纹 ;死后 4h、 6h横纹清晰 ;死后 12h肌原纤维断裂 ,仍可见横纹 ;死后 2 4h肌原纤维断裂、融合。各组大鼠肌节长度与同组立即取材时比较 ,死后 2h、 4h、 6h、 8h均显著变短 (P值均小于 0 0 0 1) ,其中死后 4～ 6h最短 ;死后12h均无显著性差异 (P值均大于 0 0 5 ) ;死后 2 4h ,组 1、组 3无显著性差异 (P值均大于 0 0 5 ) ,组 2差异显著(P值为 0 0 0 7)。结论用扫描电镜测定肌节长度 ,发现肌节长度随尸僵经过时间的延长而发生变化     

On the estimation of lay-time by measurements of rigor mortis

Measurements of the torgue to overcome rigor mortis on the legs of 101 male human cadavers at 5 degrees C are reported. There seems to exist an upper limit, which is dependent on the lay-time, above which no value occurs, but below which every value may be found. By calculating the 90% tolerance limits for lay-times grouped at 12-hourly intervals, this upper limit was found to decrease exponentially with lay-time. This may be used for the estimation of maximum lay-times from rigor mortis measurements.     

Reconsideration of the sequence of rigor mortis through postmortem changes in adenosine nucleotides and lactic acid in different rat muscles

We examined the changes in adenosine triphosphate (ATP), lactic acid, adenosine diphosphate (ADP) and adenosine monophosphate (AMP) in five different rat muscles after death. Rigor mortis has been thought to occur simultaneously in dead muscles and hence to start in small muscles sooner than in large muscles. In this study we found that the rate of decrease in ATP was significantly different in each muscle. The greatest drop in ATP was observed in the masseter muscle. These findings contradict the conventional theory of rigor mortis. Similarly, the rates of change in ADP and lactic acid, which are thought to be related to the consumption or production of ATP, were different in each muscle. However, the rate of change of AMP was the same in each muscle.     

Post-mortem interval estimation using miRNAs of road traffic accident cases: A forensic molecular approach

In forensic examination accurate estimation of post-mortem interval (PMI) is a challenging task, particularly in the advanced stages of decomposition. The existing methods (algor mortis, livor mortis, rigor mortis, putrefaction etc) used for estimating PMI rely on analyzing the physical, biochemical, and metabolic changes that occur in the corpse after death. While these methods have shown some level of effectiveness in estimating PMI during the early stages of decomposition, accurate estimation becomes increasingly challenging during the later stages of putrefaction when the body undergoes significant changes. Recently, microRNA (miRNA) profiling due to its relatively small size and stability has emerged as a promising tool in several areas of forensics. This study demonstrates the potential of miRNA for PMI estimation in advanced stages of death. In this study, miRNA-195, miRNA-206, and miRNA-378 were selected as target miRNAs and miRNA-1 as reference miRNA. Left ventricle tissue (5 g) of the heart from 20 forensic autopsies of traffic accident victims (18–32 years) were collected and processed. The samples were held at room temperature for eight different time intervals (12, 24, 48, 72, 96, 120, 168 and 196 h), and RNA was extracted from all the samples using Trizol-based RNA isolation protocol, followed by cDNA synthesis and amplification with commercially available specific miRNA probes in Real-Time PCR (RT-PCR), Ct was calculated. The result showed that miRNAs were associated with PMI. Over time, there were substantial changes in the Ct values of all three miRNAs, with significant reductions observed at 196 h compared to 12 h. miRNA-206 demonstrated significant changes at multiple time intervals, while miRNA-1 remained stable for up to 196 h and thus holds caas an endogenous marker. In conclusion, miRNA has the potential to serve as a valuable tool for estimating PMI, especially during the advanced stages of decomposition, when used in conjunction with established techniques. However, further validation of the study is required to obtain more accurate estimates of PMI.     

急慢性酗酒后脑组织Ngb、Hif-1α表达和Na^＋,K^＋-ATPase活性变化与TSAH的关系

目的探讨急慢性酗酒后脑组织脑红蛋白（Ngb）、缺氧诱导因子1α（Hif-1α）表达和Na＋,K＋-ATPase活性变化及与外伤性蛛网膜下腔出血（TSAH）的关系。方法雄性SD大鼠146只,随机分为急、慢性模型两大组,每组再各分为灌酒打击、灌水打击及单纯灌酒3个组,其中各打击组于最后一次灌胃后2h,用单摆式打击装置制作脑震荡模型;断颈处死大鼠,用免疫组化法观察脑组织Ngb、Hif-1α的表达、用分光光度法检测Na＋,K＋-ATPase。结果急、慢性灌酒打击组TSAH发生率分别为28.6%和82.4%;各灌酒打击和单纯灌酒组Ngb、Hif-1α-IOD值均显著高于各灌水打击组（P〈0.01）;急性单纯灌酒组2-4h Na＋,K＋-ATPas活性明显低于灌水打击组（P〈0.01）;慢性单纯灌酒组2h Na＋,K＋-ATPase活性高于急性灌酒组（P〈0.01）,而低于灌水打击组（P〈0.05）。结论急慢性灌酒后,脑组织Ngb、Hif-1α均呈反应性增强,Na＋,K＋-ATPase活性降低,酒精作用可能参与了TSAH的发生和死亡过程。     

RyR2相关心脏性猝死的研究进展

雷诺定受体2(ryanodine receptor 2,RyR2)是心肌细胞肌浆网上主要的钙释放通道,主要参与心肌的兴奋收缩耦联过程,其基因突变及调控异常可导致心肌舒张期钙漏引起心律失常,甚至猝死。本文重点综述RyR2基因突变及调控异常引起心脏性猝死的机制,并对以后的研究提出建议,旨在为心脏性猝死的法医学诊断提供一种新的思路。     

大鼠急性心肌缺血后肌浆网RyR2 mRNA表达变化

目的 研究大鼠急性心肌缺血后心肌肌浆网兰尼碱受体蛋白2(ryanodine receptor 2,RyR2)mRNA表达的变化.方法 将SD大鼠分为正常对照组、心肌缺血组和缺血性猝死组.采用腹腔注射垂体后叶素的方法复制大鼠急性心肌缺血和猝死模型,对心肌进行半定量荧光RT-PCR检测,观察RyR2 mRNA表达水平的变化.结果 与正常对照组相比,不同时间和不同程度的急性心肌缺血后心肌肌浆网RyR2 mRNA表达均显著降低(P<0.05).结论 心肌缺血性损伤可诱导心肌钙调控蛋白RyR2 mRNA表达下调.     

Paraquat myopathy: report on two suicide cases.

We describe two suicide cases in which old paraquat was ingested. In conjunction with lung involvement a pronounced degeneration was observed in skeletal muscle of one who died on the 14th day after the ingestion. The following sarcoplasmic or endoplasmic reticulum Ca2+ ATPase (SERCA) monoclonal antibodies were used for skeletal muscle fiber typing by an immunohistochemical method: NCL-SERCA1, reactive with type 2 fiber (fast-twitch), and NCL-SERCA2, reactive with type 1 fiber (slow-twitch). The examination revealed that the remarkably degenerated fibers belonged to type 1 muscle fibers. This case showed an abrupt increase of plasma CK levels (1796 mU/ml) on the fifth day after the ingestion. The authors presume that the damage to the skeletal muscle had occurred in this period. The degeneration of the muscle seemed to be attributable to the long retention of paraquat in the tissue because these findings were not observed in the other case who died on the fifth day. Paraquat-induced myopathy may develop in prolonged paraquat poisoning. The examination of CK levels in plasma will be useful for diagnosis of damage of skeletal muscle.     

Factors and circumstances influencing the development of hemorrhages in livor mortis

Petechial hemorrhages or ecchymoses in the skin of the face and/or in eyelids and/or conjunctivae are one important feature in postmortem diagnosis of lethal strangulation. On the other hand, petechial bleedings can occur in various causes of death, especially in cases of neck or thoracic compression, they can occur in acute cardiac failure, as a result of blood or skin diseases or as a postmortem phenomenon. The focus of this investigation (retrospective study of 279 corpses, found initially in a prone position or some other face down position) was to analyse the frequency of postmortem (hypostatic) hemorrhages and factors which may influence their development. Petechial hemorrhages in livor mortis in the skin of the trunk and extremities were found in 110 cases (39%). The frequency ranged from 41% in the side position and 44% in the kneeling position to 50% in the prone position. Increasing intensity of livor mortis resulted in an increasing frequency of hemorrhages, up to 59%. In cases with a body-mass-index (BMI) of more than 26 the frequency of hemorrhages increased up to 64%. In cases without livor mortis when the corpses were found as well as in cases with complete movement of livor mortis after turning the corpses, no hemorrhages were found. If hypostasis was partly or completely fixed, the rate of hemorrhages increased up to 50%, without additional increase in longer postmortem intervals. Obviously postmortem petechiae develop neither very soon nor days after death, but within a period of several hours after death.     

Estimating time of death of deer in Missouri; a comparison of three indicators

Estimation of time of death (TOD) of white-tailed deer is important to wildlife law enforcement officers. The purpose of this study was to develop and test a model for estimating TOD of white-tailed deer in Missouri. We compare the utility of carcass temperature, pupil diameter, and rigor mortis as TOD indicators. The effects of body size, ambient temperature, and various carcass handling methods on the estimate were also examined. Data were collected from 1484 deer during the 1995-96 and 1996-97 hunting seasons. Stepwise regression indicated that all three indicators were significant and that body size and ambient temperature could influence the model. Predictive equations were developed for various combinations of the indicators based on practicality and statistical probabilities. TOD was estimated for 28 animals where the exact TOD was known. There was no significant difference between the estimated and known TOD (p = 0.759) and the average of the absolute differences in 1 h and 28 min.