Cessation of livor in defined pressure conditions

In 28 cases of sudden death, the corpses were tested for the effect of different storage temperatures (5 degrees C, 14 degrees-15 degrees C, 25 degrees C) regarding the reaction of livor mortis to known pressure conditions (force and duration of pressure). The reaction is dependent on the storage temperature but there is no linear relationship. At certain storage temperatures the postmortem lividity reaction is dependent on the amount and duration of the pressure. In addition, at defined storage temperature and pressure conditions, there are large interindividual differences in the estimation of time of death.     

Effects of refrigeration on the biometry and development of Protophormia terraenovae (Robineau-Desvoidy) (Diptera: Calliphoridae) and its consequences in estimating post-mortem interval in forensic investigations

The aim of this study was to simulate the low temperatures that insects could experience between the time being sampled from cadavers and their arrival in the laboratory. This was in order to investigate the effect of low temperature on development of maggots. At different stages of development, individuals of Protophormia terraenovae (Robineau-Desvoidy) reared at 24 degrees C were submitted to a temperature of 4.0+/-0.5 degrees C for a period varying from 1 to 10 days. Independent of the stage of development at which the insects were refrigerated, the treatment induced significant changes on the duration of development. The effect of low temperature on the developmental time between the return to 24 degrees C to adult emergence depended on the larval stage that was refrigerated. When first instar larvae and prepupae were refrigerated, the time to emergence at 24 degrees C decreased with an increase of duration of the refrigeration period. Time to emergence increased under the same conditions when second instar larvae and pupae were refrigerated. These results indicate that keeping larvae of P. terraenovae at 4 degrees C does not just simply lead to a cessation of metabolism but disturbs the regular development. Ten days of cooling induced an error in estimating post-mortem interval (PMI) of more than 6h.     

Headspace gas chromatographic determination of ethanol: the use of factorial design to study effects of blood storage and headspace conditions on ethanol stability and acetaldehyde formation in whole blood and plasma

Our headspace gas chromatographic flame ionization detection (HS-GC-FID) method for ethanol determination showed slightly, but consistently, low ethanol concentrations in whole blood (blood) in proficiency testing programs (QC-samples). Ethanol and acetaldehyde were determined using HS-GC-FID with capillary columns, headspace equilibration temperature (HS-T degrees ) of 70 degrees C and 20 min equilibration time (HS-EqT). Full factorial designs were used to study the variables HS-T degrees (50 degrees -70 degrees C), HS-EqT (15-25 min), ethanol concentration (0.20-1.20 g/kg) and storage at room temperature (0-6 days) with three sample-sets; plasma, hemolyzed blood and non-hemolyzed blood. A decrease in the ethanol concentration in blood was seen as a nearly equivalent increase in the acetaldehyde concentration. This effect was not observed in plasma, indicating chemical oxidation of ethanol to acetaldehyde in the presence of red blood cells. The variables showed different magnitude of effects in hemolyzed and non-hemolyzed blood. A decrease in ethanol concentration was seen even after a few days of storage and also when changing the HS-T degrees from 50 to 70 degrees C. The formation of acetaldehyde was dependent on all the variables and combinations of these (interactions) and HS-T degrees was involved in all the significant interaction effects. Favorable instrumental conditions were found to be HS-T degrees of 50 degrees C and HS-EqT of 15-25 min. The ethanol concentrations obtained for the range 0.04-2.5 g/kg after analyzing authentic forensic blood samples with a HS-T degrees of 50 degrees C were statistically significantly higher than at 70 degrees C (+0.0154 g/kg, p < 0.0001, n = 180). In conclusion, chemical oxidation of ethanol to acetaldehyde in the presence of red blood cells has been shown to contribute to lowered ethanol concentrations in blood samples. Storage conditions before analysis and the headspace equilibration temperature during analysis were important for the determination of blood ethanol concentrations.     

Specific research of antigens of the ABO system in samples of decayed blood

Liquid blood and blood stains were examined after storage under different conditions and temperature regimes ranging from 18 to 26 degrees C. Blood stains were washed by distilled water or heated to 120 degrees C for as long as 4 hours. Then, blood groups were determined by absorption-elution.     

The post mortem alterations of myofibrilar proteins and adenosintriphosphatase activities of the skeletal muscles (author's transl)]

Immediately after the death of rabbits and at different times within 48 hours, we took out a part of the psoas muscle, from which we made myofibrilar preparations. The carcasses providing the muscle samples were held at two different temperatures. One group was held for 48 hours at 25 degrees C, imitating room temperature. The other group was held for 12 hours at 25 C degrees and at 25 C degrees and 12 hours at 10 C degrees, imitating daily temperature changes. Each myofibrilar sample was subjected to SDS-polyacrylamide gel electrophoresis. In addition we determined the Ca++ activated and the EGTA inhibited ATPase specific activity of the myofibrils. We found that within 48 hours the myofibrilar proteins were subjected to some characteristic proteolytic changes, which were dependant on the environmental temperature. The most interesting change was found in carcasses held constantly at 25 C degrees for 48 hours, where the EGTA inhibited ATPase activity was increased to about seven times its initial value, reflecting impairment of the troponin complex.     

Dynamics of postmortem autolysis of cardiomyocytes

Dynamics of postmortem autolysis of cardiocytes was evaluated using cells and tissues obtained from the patients who died from acute forms of ischemic heart disease, such as acute coronary insufficiency and acute myocardial infarction in the pre-necrotic phase. The studies were carried out at a temperature of 7, 20, and 37 degrees C. It was shown that autolysis of cardiac muscular fibers proceeds through three successive stages. A rise in temperature from 7 to 20 degrees C accelerated autolysis by one third while further elevation of the temperature up to 37 degrees C was associated with a 9-fold decrease in the duration of autolysis.     

Postmortem production of ethanol in different tissues under controlled experimental conditions

The aim of this study was to follow the postmortem ethanol production phenomenon under controlled experimental conditions (temperature, time interval) in different tissues. Specimens of blood, liver, skeletal muscle and kidney were taken from 30 corpses and no chemical preservatives were used in the specimens collected. Ethanol concentrations were detected by gas chromatography. All specimens stored at -20 degrees C and 4 degrees C did not show any change in ethanol concentration in an eight-day time interval. At 20 degrees C and 30 degrees C, all tissues, except blood, showed statistically significant ethanol production over the time interval tested. However, blood sample kept at 30 degrees C, showed statistically significant increase in ethanol production on the 2nd and 4th day comparing to the controls. Thus, we can state that postmortem ethanol production occurs in different tissues, and is increased at higher temperatures and, in general, it is in accordance with the course of time.     

血液中乙醇保存稳定性研究

目的确定血液中乙醇最佳保存条件,探讨影响血液中乙醇含量稳定性的主要因素。方法对血液保存的温度(-20、4、20℃)、防腐剂(NaF、无防腐剂、Na2O2)、储存容器中空气所占比例(0%、25%、50%)和血醇质量浓度(0.2、0.8、2.0mg/mL)四个因素采用正交试验L9(34)方法分组,样本采用顶空气相色谱法进行测定,测定结果采用方差分析进行讨论。结果在20℃保存且不加入防腐剂的两组样本中血醇浓度变化明显,其余变化不明显。结论血液样本在4℃、储存容器中空气比例为50%和加防腐剂(NaF)的条件下保存,稳定性最佳;四个影响因素中温度为影响血液中乙醇含量稳定性的主要因素。     

Trial elution of semen stains and measurement of IgG level: a contribution to Gm typing

The conditions for the elution of IgG in seminal stains have been investigated systematically. The amount of IgG recovered could neither or hardly be influenced by variation of the time (15 minutes to 120 hours) and temperature (4 degrees C, 20 degrees C, 37 degrees C, 56 degrees C) of elution, nor by mechanical treatment (cutting in small pieces, crushing), ultrasonic treatment or addition of a detergent. For fresh traces and such of an age of several weeks an elution time of 30 minutes at room temperature is sufficient; for very old stains an elution up to 2 hours may be recommended for safety. The investigations were restricted to the measurement of the IgG concentration in the eluates. No statement can yet be given about the biological value of the IgG for Gm typing due to this investigation alone.     

C7 typing of blood stains using isoelectric focusing and immunoblotting

By means of isoelectric focusing and immunoblotting C7 types were clearly demonstrated from bloodstains which had been stored at 37 degrees C for up to three weeks, at room temperature for up to six weeks and at 4 degrees C for over ten weeks. The C7 typing is practically useful in medicolegal individualization of unknown bloodstains.     

Blood, bone marrow and eye fluid ethanol concentrations in putrefied rabbits

The effect of putrefaction on postmortem blood, bone marrow and eye fluid ethanol levels was evaluated in rabbits. Control and dosed animals were sacrificed and stored at either room temperature (approx. 19 degrees C) or cold temperature (approx. 3.5 degrees C) for as long as 28 days. Control animals stored at room temperature showed ethanol levels in the bone marrow that peaked at 7 days after sacrifice, followed by decreases to a nondetectable level at 21 days. Overall decreases were demonstrated in bone marrow of dosed rabbits stored at room temperature for all postmortem intervals. The control animals stored at low temperature showed no ethanol in the bone marrow and blood until 21 days after sacrifice. Dosed rabbits stored at low temperature showed no significant changes in blood and marrow ethanol until 21 days after sacrifice.     

Scanning electron microscopy of incinerated teeth

The aim of the present scanning electron microscopy study was to document the nature of morphologic changes occurring in human enamel and dentin subjected in vitro to temperatures in the range of 200-1,000 degrees C for variable times. The results of the investigation confirm that human enamel and dentin remain microscopically identifiable after incineration at 1000 degrees C. Furthermore, these tissues remain identifiable after incineration at 1,000 degrees C for periods greater than 3 h. No consistent or reliable differences in morphology could be detected in enamel or mineralized dentin incinerated in the temperature range 200-600 degrees C. Temperature-dependent changes involving the predentin zone were observed. Following incineration at 800 degrees C for over 3 h and at 1,000 degrees C for 3 h, a metamorphosis of enamel and dentin into a globular form was observed.     

AmpFlSTR Profiler Plus and AmpFlSTR COfiler analysis of tissues stored in GenoFix, a new tissue preservation solution for mass disaster DNA identification

A preliminary study was conducted to assess the capability of a new alcohol-based tissue fixative, GenoFix, to preserve DNA from biopsy tissues stored at room temperature and/or -20 degrees C in a freezer, for subsequent short tandem repeat (STR) DNA typing analysis. Fresh human smooth muscle samples were stored at room temperature in GenoFix for one month and up to one year and seven months before being processed using the megaplex STR systems, AmpFlSTR Profiler Plus and AmpFlSTR COfiler. Alternatively, muscle tissues in GenoFix were placed at -20 degrees C in a freezer for up to 3 1/2 years following two to three months in the fixative at room temperature. DNA analysis was also carried out on tissues stored in GenoFix for one month at room temperature and subsequently paraffin-embedded and stored at room temperature for four years. The AmpFlSTR Profiler Plus and AmpFlSTR COfiler STR profiles produced, using DNA extracted from all fixed tissue samples, were of very good quality. The fluorescent signals were well balanced across the nine STR loci or six loci comprised in the megaplexes surveyed and profiles showed no differences with those observed for the control blood of the respective donor patients. Continuous exposure to GenoFix at room temperature (up to one year and seven months) did not compromise the STR typing analysis of the fixed tissues. No adverse effects were noted on the STR typeability of tissues fixed with GenoFix and stored at -20 degrees C in a freezer for up to 3 1/2 years. STR profiles generated from the paraffin-embedded tissues fixed in GenoFix were of excellent quality. This preliminary study suggests that GenoFix can be used to store tissue samples at room temperature for up to one year and seven months or at -20 degrees C in a freezer for longer storage (up to 3 1/2 years). This new and odorless tissue fixative promotes tissue and DNA preservation in a very effective manner and as such may prove useful in criminal investigations or mass disaster identifications carried out in remote locations and in which a small or large number of tissue samples are collected for further analyses.     

Isolation of tooth pulp cells for sex chromatin studies in experimental dehydrated and cremated remains.

In experiments designed to assess sex chromatin in artificially mummified and heated pulp tissue, a method was devised that successfully separates cells while minimizing nuclear damage. Sex chromatin (both Barr bodies and F-bodies) is shown to preserve in dehydrated human pulps up to one year. Human pulp tissue retains sex diagnostic characteristics when heated to 100 degrees C for up to 1 h. Parallel experiments on extracted teeth from young pigs reveals comparable tissue preservation. Heat penetration is retarded, however, in unextracted pig teeth in fleshed jaws such that temperatures could be raised to 300 degrees C for longer than 1 h. Heat penetration into fleshed material was further tested by the insertion of thermocouple probes to assess the temperature attained within the pulp chamber. At chamber temperatures up to 75 degrees C sex diagnosis in human pulps from extracted teeth was still possible. In outdoor incineration of fleshed pigs' heads in an open fire, 75 degrees C in the pulp chamber was reached at a fire temperature within the range 500-700 degrees C. The implications of these findings for forensic situations are described.     

Time of death of victims found in cold water environment

Limited data is available on the application of post-mortem temperature methods to non-standard conditions, especially in problematic real life cases in which the body of the victim is found in cold water environment. Here we present our experience on two cases with known post-mortem times. A 14-year-old girl (rectal temperature 15.5 degrees C) was found assaulted and drowned after a rainy cold night (+5 degrees C) in wet clothing (four layers) at the bottom of a shallow ditch, lying in non-flowing water. The post-mortem time turned out to be 15-16 h. Four days later, at the same time in the morning, after a cold (+/- 0 degrees C) night, a young man (rectal temperature 10.8 degrees C) was found drowned in a shallow cold drain (+4 degrees C) wearing similar clothing (four layers) and being exposed to almost similar environmental and weather conditions, except of flow (7.7 l/s or 0.3 m/s) in the drain. The post-mortem time was deduced to be 10-12 h. We tested the applicability of five practical methods to estimate time of death. Henssge's temperature-time of death nomogram method with correction factors was the most versatile and gave also most accurate results, although there is limited data on choosing of correction factors. In the first case, the right correction factor was close to 1.0 (recommended 1.1-1.2), suggesting that wet clothing acted like dry clothing in slowing down body cooling. In the second case, the right correction factor was between 0.3 and 0.5, similar to the recommended 0.35 for naked bodies in flowing water.     

Heat stroke deaths caused by electric blankets: case report and review of the literature

Heat stroke is the most serious and potentially life-threatening condition of the heat-related illnesses. Heat stroke deaths caused by electric blanket are rarely reported. In this paper, we report 2 cases of fatal heat stroke caused by overheating from electric blankets in winter. One was a 41-year-old man who was found unresponsive in bed on an electric blanket. His wife shared the same bed with him and was found unconscious. The wife's axillary temperature was 40 degrees C (104 degrees C) when she was admitted to the hospital. She fully recovered after medical treatment. The husband was pronounced dead at scene, with rectal temperature at 41.2 degrees C (106.2 degrees C). The other was a 13-year-old girl who was found dead in bed on an electric blanket, with rectal temperature at 41 degrees C (105.8 degrees F). The literature is reviewed, and the pertinent findings, including scene investigations, postmortem examination, the risk and mechanism of fatal heat stroke caused by using electric blanket, are discussed.     

Effect of temperature on development of the forensically important holarctic blow fly Protophormia terraenovae (Robineau-Desvoidy) (Diptera: Calliphoridae)

Immature development times of the blow fly Protophormia terraenovae (Robineau-Desvoidy, 1830) were studied in the laboratory at five different constant temperatures (15, 20, 25, 30, 35 degrees C). The minimal duration of development from oviposition to adult emergence was inversely related to temperature, ranging from 9.19+/-0.3 days at 35 degrees C to 37.78+/-2.96 days at 15 degrees C. From linear regression of development rates at the five studied constant temperature regimes, it followed that the minimum development threshold (t(L)) for total immature development is 8.95 degrees C ( approximately 9 degrees C) and the overall thermal constant (K) for P. terraenovae is 240.2+/-9.3 day-degrees (DD) above the threshold. Linear regression of developmental rates from oviposition to pupariation resulted in a minimum development threshold of 9.8 degrees C. However, it is possible that developmental time from oviposition to adult eclosion might be different in various regions of the world, and that the thermal constant of a holarctic species like P. terraenovae is not same everywhere. Additionally, as the present paper shows, studies characterizing variation in these parameters between geographically distinct populations of the same species would be of great value for future forensic entomological casework.     

Cooling rates of the ear and brain in pig heads submerged in water: implications for postmortem interval estimation of cadavers found in still water

The state of the art for determining postmortem interval in submerged bodies reflects a serious lack of studies. The objectives of the present study were therefore to study cerebral and tympanic cooling in water and its relation to cooling in air, in a pig model. First of all, cerebral and tympanic cooling on a single head and on an entire body were compared and proven to be very similar in air and in water. Nine pairs of heads were then exposed to 9 temperature intervals from 0 degrees C to 20 degrees C. For every set temperature, one head was placed in water, the other in "ambient" air in a thermostatic chamber. Ear and brain temperature were simultaneously measured every 10 minutes during 8 hours. Results showed that both in air and in water, cooling curves were almost exponential, regardless of the site (ear or brain) or the environmental temperature. Cooling was always more rapid in water than in air. Cerebral and tympanic cooling always had a correlation coefficient of 0.98-0.99. Assuming that these cooling patterns are applicable to man, this research may provide a starting point for postmortem interval estimation in submerged cadavers.     

Identification and significance of delta-aminovaleric acid in putrefaction materials (author's transl)]

During former putrefaction experiments regularly a proteogenic substance has been found which by means of modern analytical methods now was identified as delta-aminovaleric acid (DAVA). DAVA seems to appear in guinea pig as well as human organs and some body fluids under experimental conditions never before the 3rd (20 degrees C) to 5th day (10 degrees C). It is characterized by statistically significant increases until the end of the 2nd (20 degrees C) to 5th week (10 degrees C) and relatively stable values thereafter. Considering storage temperature measurement of DAVA concentration can be of relevance for the estimation of the time of death in cases of putrescent corpses.     

Detection of ABH blood group antigens in the saliva of Koreans and their stability according to storage of saliva samples

The purpose of the present study was to identify salivary molecules carrying the ABH blood group antigens in Koreans and to investigate the changes in these antigens according to processing and storage of saliva samples. Secretor or non-secretor phenotypes and salivary components carrying the ABH antigens were identified in 90 subjects, 30 subjects in each ABO blood group, by SDS-PAGE and immunoblotting. Saliva samples were then obtained from 12 secretors-two males and two females in each ABO blood group and aliquots of both fresh saliva samples and their supernatants after centrifugation were stored at room temperature, 4, -20 and -70 degrees C. The same experiments were performed after 1, 3 and 6 months to investigate changes in the blood group antigens. In all 68 secretors, high-molecular-weight salivary mucin (MG1) was found to be the primary carrier of the ABH antigens. A salivary component of approximately 80 kDa also carried H antigen in seven saliva samples of 22 blood type O secretors. The blood group antigens were better detected in centrifuged samples. In saliva samples preserved at room temperature and 4 degrees C, the blood group antigens were either not detected or detected as degraded molecules. No change was found in the blood group antigens in saliva samples preserved at -20 and -70 degrees C for 6 months.