Postmortem activity of the key enzymes of glycolysis. In rat brain regions in relation to time after death

The activities of the rate-limiting enzymes of glycolytic pathway were measured in various areas of rat brains kept at a temperature of +25 degrees C for various intervals after death by cervical dislocation. Hexokinase shows a substantial decline in activity over a period of 24 h, reaching 41%, 57%, 44%, and 51% of the controls in cerebellum, medulla oblongata and pons, cerebral cortex, and diencephalon, respectively. In the same areas the phosphofructokinase reached 28%, 61%, 60%, and 40% of the zero-time activity, respectively. Lactate dehydrogenase behaves differently in the four areas, with an increase in cerebral cortex and diencephalon and a decrease in cerebellum and medulla oblongata and pons. Pyruvate kinase activity was quite stable over the 24 h period studied. Therefore, the activities of hexokinase and phosphofructokinase in brain tissue were of little value for diagnosis of the time of death.     

Aminopeptidase and cathepsin A activity in vitreous humor in relation to causes of death

Brain autolysis happens rapidly, especially when environmental temperatures are high, and poses serious limitations for evaluating damage using morphologic methods. In the present study we have measured total proteins, cathepsin A and aminopeptidase activity in the vitreous humor in relation to cause of death and survival time. We have studied vitreous humor samples from 106 cadavers autopsied in the I.A.F. of Granada. The samples were classified according to causes of death as follows: myocardial infarction; hanging; other mechanical asphyxias; multiple trauma; craniocerebral trauma; other violent death; pulmonary functions; and other natural deaths. Total protein was measured by Lowry's method, and cathepsin A and aminopeptidase activity by the Bowen and Davison (1973) and Greenberg (1962) methods, respectively. Results are expressed in IU/l and in mIU/mg of protein. We found higher values of aminopeptidase and cathepsin A activity in groups with severe brain damage (craniocerebral trauma, multiple trauma, etc.) and lower values in groups of natural deaths. We believe, therefore, that aminopeptidase activity in vitreous humor may be a useful parameter for evaluating brain damage.     

家兔死后红细胞内钾钠离子含量与死亡时间的关系

研究了40只家兔死后不同时间心血红细胞内钾钠离子含量变化及红细胞膜Na+－K+－ATP酶活性。发现红细胞内钾离子含量随死亡时间增加呈线性下降（r=-0．829,P＜0．025）。在死后0－48小时,红细胞内钾离子含量与死亡时间显著相关。红细胞膜Na+－K+－ATP酶活性在死后48小时无显著变化。     

Morphometric approaches to diagnosing the time of death

A new method has been used to evaluate the time of death. The relationship between the degree of autolysis of cadaveric viscera and time of death has been studied by histomorphometrical methods. The study was carried out on histological preparations of the lungs, heart, liver, spleen, and kidneys from 20 corpses of humans dead from craniocerebral injuries. Based on the results, tables were created for evaluating the time of death even at remote periods after death, when the results of other methods are unreliable.     

Postmortem serum catecholamine levels in relation to the cause of death

Catecholamines are major humoral factors and neurotransmitters that contribute to various stress responses. However, they have been considered unstable due to agony, terminal medical care and postmortem interference. The present study was a comprehensive investigation of postmortem serum levels of adrenaline (Adr), noradrenaline (Nad) and dopamine (DA) with regard to the cause of death in serial medicolegal autopsy cases (n=542) including fatalities from various traumas and diseases. There was a slight tendency toward postmortem increases of Nad and DA in cardiac blood as well as Adr and Nad in peripheral blood, a slight age-dependent decrease in Adr and DA in right heart blood, and a marked increase in serum DA due to administration during critical medical care. When these factors were taken into consideration, significantly higher cardiac blood levels were observed for Adr and Nad in injury and asphyxiation cases and for Adr in fatal methamphetamine (MA) abuse and other poisoning cases, whereas those levels were lower in fatal hypothermia. Drowning, fire fatality, acute cardiac death and cerebrovascular disease showed intermediate Adr and Nad levels. The DA level was elevated in cases of injury, hyperthermia, MA fatality and other poisoning. Topographical analyses suggested that the major sources of increased serum catecholamines in cases of injury was abdominal viscera including adrenal glands, and that in cases of asphyxiation, drowning, fire fatality, hyperthermia, MA fatality, other poisoning, acute cardiac death and cerebrovascular disease was the extremities in addition to abdominal viscera. However, there was in part a large case-to-case difference in each marker related to individual causes of death. These findings differed markedly from clinical observations and suggest that the postmortem serum catecholamine levels may reflect the magnitude of physical stress responses during the process of death in individual cases.     

Enzymehistochemical and immunohistological changes of skeletal muscle motor end-plates and muscle fibers and their relation to the time of death

In order to investigate the relationship between the retrograde changes of the skeletal muscle and the time of death in various postmortem intervals (PMI), a systemic study of the enzymehistochemical activity of AChE, SDH, LDH, Ca(2+)-ATPase and the immunohistochemical reaction of SYN in motor end-plates and muscle fibers was conducted in rats under different temperatures and at various PMI. The results were analyzed and compared by an image processing system. It was found that these changes were related to the PMI, especially AChE changes. The AChE could be used as a sign-enzyme of skeletal muscle to date death.     

Cathepsin activity in the myocardium and skeletal muscles as a sign of the time of death

Determination of postmortem interval according to the time course of cathepsins activity within 5 days since death was carried out using myocardium and skeletal muscles of white breedless rats and cadavers of people who died of craniocerebral trauma. Natural time course of changes in cathepsins activity was determined which makes it possible to use these values as one of criteria in determination of postmortem interval.     

The methodological aspects of establishing the time of death]

Methodological analysis of essence of problem concerning postmortem interval estimation is given. The authors present the most promising ways of scientific research on this problem and possibilities of practical use of results of scientific research. The general methods of postmortem interval estimation including wired-in analogy (criterial) method and methods of modelling postmortal processes (mathematical and physical) are analysed. Graph of logical structures of modes of postmortem interval estimation and means of their realization is given.     

家兔死后不同时间角膜基质胶原纤维的超微结构观察

目的探讨角膜基质胶原纤维直径变化与死亡时间的关系。方法28只家兔空气栓塞致死后,按死后不同时间取角膜,常规方法制作超薄切片,应用透射电镜观察角膜基质0.5μm×0.5μm区域内的胶原纤维,并用图像分析系统测量反映胶原纤维直径变化的横切面面积(Y1)、周长(Y2)、平均直径(Y3)、等效直径(Y4)4个参数,所得数据用EXCEL2000和SPSS10.0软件进行统计分析。结果在死后0～72h内,角膜胶原纤维横断面的面积从1131±53nm增加到1628±26nm,周长从132.8±23nm增加到167.5nm,等效直径从38nm增加到45nm,平均直径从37.71±6nm增加到44.89±5nm。结论死后72h内,角膜基质胶原纤维直径随死后时间的延长逐渐增大,4个参数有望作为判断死后时间的新指标。     

Homicide with special reference to alcoholic intoxication and relation to time of day

112 cases of homicide (around 4%) are presented from material of approximately 3000 psychiatric expert-opinions for criminal proceedings. The data of 107 committers were usable and could be evaluated statistically. 63% of the homicides were executed, 37% were attempted. 14% of the committers were considered to be psychopaths. The circumstances surrounding the crimes were further subdivided in imitation of Rasch and especially tested for daytime linkage. 53% of the males but only a very small percentage of the female committers were alcoholized. Neither alcoholization nor personality had influence upon the success of the crime. For most of the psychotic committers the attempt failed to succeed. There was a tendency that some of the assaults were performed during night-time. This was more pronounced in alcoholized than in sober committers. No linkage to the night hours could be found neither for criminal actions of psychotics or child murder, nor for murder or robbery. In conclusion we assume that certain forms of human aggression underlie a diurnal rhythm.     

Estimation of the time since death

The main principle of the determination of the time since death is the calculation of a measurable date along a time-dependent curve back to the start point. Characteristics of the curve (e.g. the slope) and the start point are influenced by internal and external, antemortem and postmortem conditions. These influencing factors have to be taken into consideration quantitatively in order to improve the precision of death time estimation. It does not make any sense to study the postmortem time course of any analyte without considering influencing factors and giving statistical parameters of the variability. Comparison of different methods requires an investigation of the same postmortem interval. For practical purposes, it must be concluded that the amount of literature on estimating the time since death has a reverse correlation with its importance in practice.     

脑组织中ATP含量变化与死亡时间关系的初步研究

本文报道用生物发光法测定不同死亡时间狗脑组织中ATP含量的变化．结果表明：随着死亡时间的延长，脑组织中ATP浓度逐渐下降，这对法医在实际检案工作中推断死亡时间有一定的应用价值。