不同保存条件对血中CN-浓度的影响

目的研究在各种温度贮存条件下血液中CN-浓度与保存时间的关系。方法用氯胺T衍生GC/ECD分析。结果在室温下存放的阳性血,在30天～50天中,CN-浓度有所增加,以后浓度下降很快,80天后则检不出。在4℃及-20℃下贮存的血液CN-浓度,在一定的时间段中,有所增加,以后则逐渐下降,至8个月仍可检出CN-。结论不同条件下存放的血液CN-其浓度的变化是不同的。     

The effect of storage at various temperatures on blood alcohol concentration

There is a paucity of data available on the effect of storage on blood alcohol concentration (BAC) at elevated temperatures. Changes in serum alcohol concentration (SAC) and BAC were studied. Serum samples spiked with alcohol in the presence or absence of preservative were stored at 26.7 °, 32.2 ° or 37.8 °C respectively. Serum alcohol concentrations were determined daily on days 1 through 14, and on days 21 and 35. Under these controlled conditions, no significant change in SAC was observed at the aforementioned temperatures. Whole blood samples submitted from outside agencies were initially analyzed (day 1), then stored for 35 days at different elevated temperatures before a second analysis. The average loss in BAC was 19.20 ± 15.6, 9.95 ± 5.7, and 15.60 ± 6.9% when the samples were stored at 26.7, 32.2 and 37.8 °C, respectively. The alcohol loss from whole blood samples may be attributed to chemical oxidation rather than to elevated temperatures. It is, therefore, concluded that a whole blood sample obtained from a living individual and stored in a locker, glove compartment or other environment where the temperature is elevated, may lose 10–19% of its alcohol content over 35 days of storage. On the other hand, when a serum or plasma sample is exposed to the same environment, no significant change in SAC was observed. The utility of this information is significant to the forensic toxicologist. The results of this study suggest that a whole blood sample analyzed after exposure to elevated temperature may have had, originally, a higher BAC.     

Cause of death in heroin users with low blood morphine concentration

The blood morphine concentrations in cases of heroin-associated fatalities can vary considerably. Currently, a free-morphine concentration of > or = 100 ng/ml in blood is generally considered as potentially fatal. Moreover, it is a common observation that fatal cases of heroin-intoxication with blood morphine concentrations lower than 100 ng/ml occur. This poses the question of how the fatal cases with low blood morphine concentrations can be explained. In the study described here, 62 cases of morphine only intoxications were examined. The fatal cases were divided into two groups according to the free morphine concentrations measured in the blood of the heart (group I: free morphine concentration < 100 ng/ml, n = 21 cases; group II: free morphine concentration > or = 100 ng/ml, n = 41 cases). The two groups were compared as to circumstances of death, as well as to autopsy findings and histopathologic alterations. Overall, infections of the respiratory tract occurred significantly more often in group I (lower morphine concentrations) than in group II. In a second step, the group I cases were analyzed individually to get detailed information on the cause of death. In 19 of the 21 cases the authors could find a plausible explanation for death in combination with low free morphine concentrations in the blood.     

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.     

Cyanide distribution in five fatal cyanide poisonings and the effect of storage conditions on cyanide concentration in tissue

The cyanide distribution in five fatal cyanide poisonings was analyzed by the pyridine-pyrazolone method using a Conway diffusion cell. In order to study the effect of storage conditions on cyanide concentration in tissue samples, the cyanide concentrations were first measured immediately after collection of the samples at autopsy, then measured again after storage in a refrigerator (4 degrees C) or in a freezer (-20 degrees C) for periods ranging from 1 day to 3 weeks. Concentrations in all but three of the blood samples stored at 4 degrees C or -20 degrees C increased, with concentration ratios based on measurement made before and after storage ranging from 0.71 to 1.46. The concentrations in the liver, kidney, and brain samples either increased or decreased, with ratios of from 0.2 to 8.8. The concentrations in the stomach contents samples decreased rapidly at 4 degrees C, but hardly changed at all at -20 degrees C.     

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.     

The post-mortem concentration of glutamate in the structures of rat brain as an exponent of short aversive sensory stimulation preceding death.

The problem of post-mortem assessment of short central fear reaction preceding death has been obscure till now. The preliminary results obtained by authors have encouraged them to further research on this topic. Time of aversive sensory stimulation in the presented study was considerably decreased in comparison to the preliminary investigations. The concentration of glutamate was assayed in the selected structures of limbic system and in the cerebellum. The rats were subjected to different simultaneous modalities of sensory stimulation. The involvement of the hippocampi and the cerebellum was revealed as measured by glutamate concentration increase in the whole structures homogenates. The dominant role of mechanical stimulus has been suggested based on the measured increase of glutamate concentration in the whole cerebellum homogenate. By using the presented experimental paradigm a possible application of the biochemical assessment of human brain tissue might be developed in the future for implementing in the field of forensic pathology. The biochemical evaluation of "frozen frames" of neurotransmission can possibly help reconstruct the events which had happened just before sudden and violent death.     

Determination of blood/serum ratios of different forensically relevant analytes in authentic samples

For forensic toxicological investigations only whole blood, but no serum is often available. Pharmacokinetic data are helpful for interpreting the results, but most of these studies indicate serum or plasma concentrations. In order to obtain reliable conversion factors which also take intersubject variability into account, the blood/serum ratios (B/S) of oxycodone, morphine, fentanyl, hydromorphone, zopiclone, MDMA, dexamphetamine, alprazolam, risperidone and 9-hydroxyrisperidone were determined by LC-MS/MS using authentic samples. Blood and corresponding serum samples were obtained from driving studies performed with controlled or known dosages of the above drugs. The analytes were analysed in blood and serum and the following mean B/S ratios (relative standard deviations) were determined: oxycodone 1.48 (8.19 %); morphine 1.03 (3.59 %); fentanyl 0.87 (13.9 %); hydromorphone 1.04 (8.11 %); zopiclone 0.89 (16.1 %); MDMA 1.19 (8.04 %); dexamphetamine 0.89 (10.9 %); alprazolam 0.81 (5.84 %); risperidone 0.65 (7.52 %); 9-hydroxyrisperidone 0.73 (12.3 %). These mean values are largely in line with those reported in the literature. The B/S ratios did not appear to depend on partition coefficients, whereas there was strong evidence that B/S ratios decreased with increasing plasma protein binding.     

The effect of the THV bullet in animal tissue

The Très Haute Vitesse (THV) bullet was introduced to meet the requirements of law enforcement officers, as an alternative to larger calibre fully jacketed bullets, since expanding or exploding bullets are not relevant in Europe. To examine the effect of the THV bullet in tissue, especially the size of the lesion and the degree of overpenetration, 11 recently killed pigs were shot with the weapons used by the Danish Police Force and a 9-mm pistol for reference. The ammunition was THV in the calibres 7.65 mm, 0.38, and 9 mm, using conventional fully jacketed bullets for comparison. The lesions were considerably larger when the THV bullet was used, the entry wound in particular, being roughly twice the diameter in the case of the THV bullet as compared to the fully jacketed bullet of similar calibre. Only one 7.65-mm THV bullet overpenetrated the target when fired against the thorax or abdomen of the pigs and then with only minimal residual energy. All fully jacketed 7.65-mm bullets, all 0.38 bullets, with the exception of one THV bullet, and all 9-mm bullets overpenetrated the target. The 7.65-mm THV bullet produced a lesion which in its extent resembled that of the fully jacketed 9-mm bullet, and should be a suitable alternative for the Danish Police Force.     

Circumstances at the time of death in drug fatalities

The circumstances in drug-related deaths were investigated in this study. The basic client sample was composed of 743 drug addicts of the opiate type who had been admitted into the institute's drug-free outpatient program from 1969 to 1982. In this program, 91 clients died during the observation period. In order to be able to judge the various backgrounds adequately, a multiply subdivided classification system was developed for the death cases. Each case was recorded in three main categories: manner of death, cause of death, and phase of addiction. This was a more elaborate procedure than those commonly used since, in general, such death cases are only subdivided into a few groups that differ little from one another. Two manners of death predominated in this sample: accidents caused by poison (62%) and suicide (25%). Within in the various causes of death, poison cases prevailed (80%) and opiate intoxication (single or combined) was predominant (60%). Concerning the phase of addiction two phases were distinguished: the actual drug addiction phase (65%) and the intramural stay in prison or a hospital (25%). There were no significant sex-related differences. Various combinations regarding the mechanism of lethal opiate intoxication of drug addicts were scrutinized, concentrating on three approaches: the lack of opiate tolerance after periods of abstinence, the synergistic effect of simultaneously taking other CNS-depressant drugs, and differences in concentration in the heroin used. Our conclusions are given from the point of view of adequate counseling for drug addicts.     

The use of circular dichroism and spectrophotometric methods in establishing the time of death

Dynamics of destruction of metal-containing proteins in skeletal muscles depending on storage duration (up to 30 days) of cadaveric material was studied in vitro using spectra of circular dichroism and absorption in visible spectrum area. Dichroic absorption diminishes gradually with increase of storage duration of cadaveric material.     

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.