利多卡因蛛网膜下腔麻醉致死的动物模型

目的 建立利多卡因麻醉致死的动物模型。方法 犬蛛网膜下腔注射利多卡因(37.01mg/kg体重),观察麻醉致死过程的生命体征变化及死后各器官的病理改变特点。结果 实验组犬心电、血压和呼吸消失的平均时间分别为23.8min(7-42min)、16.4min(7-35min)和18.6min(10～47min)。各器官病理改变均呈急死征象。结论 所建模型实验动物的表现和生命体征变化符合蛛网膜下腔麻醉致死的生前表现,可应用于利多卡因麻醉意外致死案件法医学鉴定的实验研究。     

Light microscopical investigations on structural changes of skeletal muscle as artifacts after postmortem stimulation

Samples of skeletal muscle were taken from 20 human corpses where mechanical or electrical stimulation had been carried out up to 8h postmortem (hpm) in order to estimate the time since death. The stimulation had caused an idiomuscular bulge or tetanic contraction of the muscle tissue at this location. The muscle samples were examined for structural changes of the fibers by light microscopy. A comparison with control muscle samples taken contralaterally from the same corpse, showed that the findings previously interpreted as being of intravital origin, e.g. destruction of fiber integrity, invagination and contraction bands, could also be due to postmortem alterations. It is hypothesized that structural changes to the muscle fibers can, in general, be produced as long as the manifestation time is shorter than the supravital phase after the time of force impact.     

Identification of human urinary stains by enzyme-linked immunosorbent assay for human uromucoid

An enzyme-linked immunosorbent assay (ELISA) of the sandwich type for identification of human urinary stains using commercially available anti-human uromucoid was developed. When experimentally prepared urinary stains of humans and animals, 2 by 2 cm in area, were subjected to analysis, human stains could be differentiated from animal ones except chimpanzee and Old World monkey ones. Stains of other human body fluids showed negative reactions. The reactions did not decrease when human urinary stains were stored at room temperature for three months. The present ELISA provides a useful presumptive test for urinary stains of human origin.     

Increased hematocrit after applications of conducted energy weapons (including TASER(®) devices) to Sus scrofa

Conducted energy weapons (CEWs) are used by law enforcement personnel to incapacitate individuals quickly and effectively, without intending to cause lethality. CEWs have been deployed for relatively long or repeated exposures in some cases. In laboratory animal models, central venous hematocrit has increased significantly after CEW exposure. Even limited applications (e.g., three 5-sec applications) resulted in statistically significant increases in hematocrit. Preexposure hematocrit was significantly higher in nonsurvivors versus survivors after more extreme CEW applications. The purpose of this technical note is to address specific questions that may be generated when examining these results. Comparisons among results of CEW applications, other electrical muscle stimulation, and exercise/voluntary muscle contraction are included. The anesthetized swine appears to be an acceptable animal model for studying changes in hematocrit and associated red blood cell changes. Potential detrimental effects of increased hematocrit, and considerations during law enforcement use, are discussed.     

Detection of human proteins in buried blood using ELISA and monoclonal antibodies: towards the reliable species indentification of blood stains on buried material.

The survival of human proteins in blood stains on fragments of cloth buried in exposed soil was examined in a 15-month investigation carried out from September 1990 to December 1991. During this period there was a wide variety of weather conditions. Samples were exhumed at 4-weekly intervals for 16 weeks and finally at 65 weeks; extracts of the stains were tested for albumin and IgG using a highly specific and sensitive enzyme-linked immunosorbent assay (ELISA) performed with monoclonal antibodies. Human albumin survived well throughout the 15 months of study, but IgG could be detected only in the 4- and 8-week samples. The reactions for IgG were weaker than those for albumin, although the method's sensitivity (10 ng) was the same for each protein. Appropriate buried and non-buried control experiments were carried out using cloth, either unstained or stained with human blood or animal sera; there was no cross-reactivity between human and the other species investigated and soil did not affect the assay; under laboratory conditions, IgG and albumin survived equally well. The system's versatility was illustrated by using monoclonal anti-bovine-albumin to detect specific albumin in the extracts of buried cloth which has been stained with bovine serum. It was concluded that ELISA performed with monoclonal antibodies could be of great value in identifying blood stains for forensic purposes.(ABSTRACT TRUNCATED AT 250 WORDS)     

Congestive hemorrhage caused by burns?

Phenomena occurring under exposure to heat such as epidural burn hematoma, hyperemia of the internal organs and extravasation of blood into the serous mucosae have been known for a long time. There has so far been less attention to an alteration which was recently observed in two burn corpses. These were punctiform hemorrhages in the conjunctivae as well as hemorrhages in the throat musculature which initially suggested application of force to the neck. After it could be established by usual investigations that the cases were suicides, an attempt was made to clarify the origin of these hemorrhages and the question of their vitality in animal experiments. To the extent that unequivocal results could be obtained, these indicated that the blood extravasations are vital phenomena which are associated with the still-intact circulation. However, differentiation between the action of third parties and extravasation of blood due to heat it difficult and can only be possible with the consideration of the overall circumstances in the individual case.     

Acidosis, lactate, electrolytes, muscle enzymes, and other factors in the blood of Sus scrofa following repeated TASER exposures

Repeated exposure to electro-muscular incapacitating devices could result in repetitive, sustained muscle contraction, with little or no muscle recovery period. Therefore, rhabdomyolysis and other physiological responses, including acidosis, hyperkalaemia, and altered levels of muscle enzymes in the blood, would be likely to occur. Experiments were performed to investigate effects of repeated exposures of TASER International's Advanced TASER X26 on muscle contraction and resultant changes in blood factors in an anaesthetized swine model. A total of 10 animals were used. Six swine were exposed for 5 s, followed by a 5-s period of no exposure, repeatedly for 3 min. (In five of the animals, after a 1-h delay, a second 3-min exposure period was added.) The remaining four animals were used for an additional pilot study. All four limbs of each animal exhibited contraction even though the electrodes were positioned in areas at some distances from the limbs. The degree of muscle contraction generated during the second exposure period was significantly lower than that in the first exposure series. This finding was consistent with previous studies showing that prolonged activity in skeletal muscle will eventually result in a decline of force production. There were some similarities in blood sample changes in the current experiments with previous studies of muscular exercise. Thus problems concerning biological effects of repeated TASER exposures may be related, not directly to the "electric output" per se, but rather to the resulting contraction of muscles (and related interruption of respiration) and subsequent sequelae. Transient increases in hematocrit, potassium, and sodium were consistent with previous reports in the literature dealing with studies of muscle stimulation or exercise. It is doubtful that these short-term elevations would have any serious health consequences in a healthy individual. Blood pH was significantly decreased for 1h following exposure, but subsequently returned toward a normal level. Leg muscle contractions and decreases in respiration each appeared to contribute to the acidosis. Lactate was highly elevated, with a slow return (time course greater than 1 h) to baseline. Other investigators have reported profound metabolic acidosis during restraint-associated cardiac arrest. Since restraint often occurs immediately after TASER exposure, this issue should be considered in further development of deployment concepts. On the basis of the results of the current studies, the repeated use of electro-muscular incapacitating devices in a short period of time is, at least, feasible, with the caveat that some medical monitoring of subjects may be required (to observe factors such as lactate and acidosis).     

Zur ultrastruktur vitaler,postmortaler und autolysierter gerinnsel

Investigations on animal experimental and human tissue material (skin, musculature, liver) with the scanning electron microscope are reported. These studies were carried out to clarify open questions on extravascular fibrin structures after blunt and sharp traumatization of vital and postmortem nature. The network formation which was already characterized earlier as typically vital and the irregular structure of postmortem coagula could be demonstrated even with modification of the traumatization, especially in tissue hematomas. Experimental investigations on autolysis revealed an exceedingly good preservation of the structure of vital coagulum material with massive damage and granular decomposition of fibrin fiber structures produced postmortem. The structural differences in the mode of interlinking of the fibrin was shown up especially clearly by the autolysis, which suggests an application as preparation technique for the question specified.Special modifications of the preparation technique (fixation according to Karnovsky, critical-point drying) did not provide such substantial advantages for routine investigations that they might be generally recommended.Sources of artefacts and possibilities of misinterpretation of findings as well as more advanced techniques are discussed.     

人骨骼肌线粒体DNA4977片段缺失与年龄的相关性调查

目的 探讨人骨骼肌组织中线粒体DNA 4977bp片段的缺失情况及其与年龄的相关性.方法 收集105例不同年龄死者的骨骼肌组织,抽提MDT,通过CPR、琼脂糖紫外凝胶成像等技术,测定不同年龄组线粒体DNA 4977bp片段的缺失情况.结果 在105例样品中,不同年龄组(0～9、10～19、20～29、30～39、40～49、50～59、60～69、70～79、80～89、90～99岁)mtDNA4977片段缺失的频率分别为:0、0、0.003%、0.011%、0.015%、0.033%、0.038%、0.062%、0.069%、0.091%.结论 人骨骼肌线粒体DNA 4977bp片段的缺失频率随着年龄的增长而增高,各年龄组之间具有显著差异(P《0.01).该缺失片段的检测对于软组织年龄推测具有一定指导意义.     

Tissue-specific differences in mRNA quantification of glucose transporter 1 and vascular endothelial growth factor with special regard to death investigations of fatal injuries

Glucose transporter 1 (GLUT1) and vascular endothelial growth factor (VEGF) have been established as being responsible for cellular adaptation to oxygen deficiency in tissue ischemia and hypoxia mediated by hypoxia-inducible factor 1. We hypothesized that mRNA quantification of these factors in autopsy tissue specimens could have diagnostic significance for investigating the pathology of death, especially after injury. Various cases (total, n=119; less than 48h postmortem) were examined, including fatal blunt injury (n=71) and sharp instrument injury (n=18), as well as asphyxia (strangulation/hanging, n=12) and acute myocardial infarction/ischemia (n=18) as controls. Quantification of mRNA by TaqMan real-time RT-PCR and immunostaining were performed for GLUT1 and VEGF in lung, kidney, and skeletal muscle specimens. The postmortem interval showed no significant influence on the relative quantification of mRNA during the early postmortem period. Characteristic results were found in blunt injury cases: both GLUT1 and VEGF mRNAs decreased in the lung but increased in the skeletal muscle depending on survival time. In the kidney, subacute deaths showed higher GLUT1 mRNA levels compared with acute deaths from blunt injury, but no significant change was found for VEGF mRNA. Immunohistochemistry showed visually predominant GLUT1 immunoreactivity in the renal cortex for cases with a longer survival time, coincident with the results at the mRNA level. Tissue-specific differences in mRNA quantification of GLUT1 and VEGF shed light on tissue ischemia/hypoxia and subsequent tissue-dependent pathophysiological changes leading to death after injury.     

大鼠骨骼肌钝挫伤分级模型的建立

目的建立一个控制性、重复性好,并可分级的骨骼肌挫伤动物模型。方法采用自行设计的机械式撞击装置,以撞击速度（velocity,v）和形变（deformation,DF）作为外力参数,并保持较恒定的撞击时间,使击锤打击瞬间速度不同,造成轻、中、重不同程度的大鼠腓肠肌挫伤。结果在肉眼、HE染色观察下．39只大鼠腓肠肌出现可分级的病理学改变。在低撞击水平（v：2m／s,DF：5．5mm）,轻度挫伤组病理改变局限于大鼠腓肠肌肌外膜和腓肠肌表层部位;在中度撞击水平（v：2．5m／s,DF：6．5mm）,中度挫伤组病理改变可见于大鼠腓肠肌肌外膜和大部分腓肠肌;在高撞击水平（v：3m／s,DF：7,5mm）,重度挫伤组病理改变除中度挫伤组累及部位外,还伤及比目鱼肌。结论该模型制作出常见的钝力性骨骼肌挫伤,以撞击速度和形变作为外力参数,成功建立了机械骨骼肌挫伤分级模型,致伤程度较一致,是骨骼肌挫伤研究较合适的动物模型,为深入研究钝力性骨骼肌挫伤奠定了基础．     

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.     

免疫印迹检测人胸大肌肌钙蛋白I推断较晚期死后经过时间

目的研究人死后骨骼肌肌钙蛋白I(Skeletal troponn in I,sTnI)的变化规律,探讨较晚期死后经过时间推断方法。方法以人胸大肌为研究对象,利用免疫印迹(W estern b lot)结合图象分析技术半定量检测不同离体时间内人胸大肌sTnI的含量,观察其与离体时间的关系。结果人胸大肌sTnI含量随离体时间延长而逐渐下降,与离体时间的对数值呈近似的线性关系:Y=11 972.5-4 761.9 lgX,相关系数r=0.989;离体5d的人胸大肌仍可检出sTnI。结论检验人死后骨骼肌(胸大肌)sTnI的含量有望成为用于推断人体较晚期死后经过时间的新技术。     

Characterization of the volatile organic compounds present in the headspace of decomposing animal remains, and compared with human remains

Human Remains Detection (HRD) dogs can be a useful tool to locate buried human remains because they rely on olfactory rather than visual cues. Trained specifically to locate deceased humans, it is widely believed that HRD dogs can differentiate animal remains from human remains. This study analyzed the volatile organic compounds (VOCs) present in the headspace above partially decomposed animal tissue samples and directly compared them with results published from human tissues using established solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS) methods. Volatile organic compounds present in the headspace of four different animal tissue samples (bone, muscle, fat and skin) from each of cow, pig and chicken were identified and compared to published results from human samples. Although there were compounds common to both animal and human remains, the VOC signatures of each of the animal remains differed from those of humans. Of particular interest was the difference between pigs and humans, because in some countries HRD dogs are trained on pig remains rather than human remains. Pig VOC signatures were not found to be a subset of human; in addition to sharing only seven of thirty human-specific compounds, an additional nine unique VOCs were recorded from pig samples which were not present in human samples. The VOC signatures from chicken and human samples were most similar sharing the most compounds of the animals studied. Identifying VOCs that are unique to humans may be useful to develop human-specific training aids for HRD canines, and may eventually lead to an instrument that can detect clandestine human burial sites.     

家兔肺脂肪栓塞后超微病理学观察

目的 研究脂肪栓塞后肺组织的超微结构变化.方法 通过向实验组家兔血管内注射脂肪诱导肺脂肪栓塞制作肺栓塞动物模型,分别于栓塞即刻(0 h)和栓塞后3、8 h及1、2、7、14d处死动物;对照组家兔注射同等剂量的生理盐水,其余处理方法与实验组相同.经HE和苏丹Ⅲ染色证实造模成功后,用透射电镜观察肺组织的超微结构变化.结果 ...     

Local vital reaction following injuries of the neck

Sixty-one cases of hemorrhaging of the laryngeal muscles are reported among 86 deaths due to compression of the neck (strangulation by ligature and/or with the hands, blunt force); the results of histological examinations of these cases (laryngeal muscles; hemorrhaging of the cervical muscles and tongue in numerous cases) are discussed, as well as 55 comparative cases (natural, violent death) with regard to vital changes from the hemorrhaging aspect. Although sanguineous infiltration of the laryngeal muscles can occur after death (prone position), it differs macroscopically and in some cases also microscopically from the vital type: extensive bleeding on the inside of the larynx or dorsally above the larynx (PCA muscle), possible combined with histologically detectable ruptures of muscle cells, must be viewed as the result of laryngeal compression suffered when still alive. No clear-cut evidence of emigration or infiltration of leukocytes was found in the cases of immediately fatal strangulation, but there was occasional evidence (6 cases) when protracted maltreatment had taken place. Although there was no clear correlation with age, sex, type of impact, cause of death, or amount of laryngeal bleeding, in 25 of the 61 cases leukocytes were sometimes detectable in enormous amounts within the extravasation; the ratio exceeded that to be expected from the composition of the blood. Findings of this nature have also been made in cases of vital bleeding in other violent or natural deaths; they are not a cell reaction in the proper sense but, when distinctly marked, a vital event--at least in the laryngeal region. These findings can support the assumption of the amount of hemorrhaging in deaths in which the survival time was inadequate for a leukocyte emigration. In 20 cases such findings were combined with localized leucocytosis, which is regarded as an early vital reaction.     

Demands on scientific studies: vitality of wounds and wound age estimation

Research on vitality and wound age estimation belongs to the classic fields in forensic medicine. Despite large literature data there is still considerable demand of further research and practical transfer of knowledge and techniques to daily casework. Scientific studies must fulfil basic criteria as to appropriate methods, selection of case material, analysis of results and quality control. Nowadays, immunohistochemistry, biochemical tests and molecular biological techniques are mainly used studying questions of vitality and wound age. Investigations can be based on human tissue samples (autopsy material, vital specimens) or animal experiments. The possibilities, advantages and disadvantages of these study designs are described. Indispensable is the use of appropriate control groups or control samples and a sufficient case number which permits statistical analysis. Main strategy is to minimize variations due to methods and investigators as the unavoidable biological variation of vitality processes and wound repair is large enough.     

人体皮肤创伤组织细胞因子表达的时间相关性

目的探讨TGF-β1、b—FGF和VEGF在人体皮肤创伤组织中的表达变化及其与损伤时间的关系。方法收集15例机械性致伤的人体皮肤组织(受伤5—120min内死亡),常规制作组织切片后进行免疫组化染色,并统计分析TGF-β1、b—FGF和VEGF因子的表达情况。结果 TGF-β1在16—50min组表达升高,60～120min组呈阳性至强阳性表达;b—FGF在16—50min组表达升高明显,强阳性表达亦出现在60～120min组;VEGF仅在60—120min组出现阳性表达。统计学分析表明,TGF—β1和b—FGF的表达升高分别在受伤60~120min(P<0.01)和在16—50min(P<0.01)有显著性意义,VEGF表达升高只在60~120min(P<0.05)有显著性意义。结论 TGF-β1、b—FGF和VEGF的表达时间和表达强度与损伤时间有关;TGF-β1、b—FGF和VEGF的表达可为人体短存活期损伤时间的推断提供参考。     

Dermestes maculatus (Coleoptera: Dermestidae) development under fluoxetine effect using two drug administration models

Fluoxetine is a selective serotonin reuptake inhibitor, commonly used for the treatment of a variety of psychopathological conditions. As such, fluoxetine may be expected to appear in clinical and forensic cases. Dermestes maculatus De Geer (Coleoptera: Dermestidae) has been recognized as a relevant component of the insect fauna associated with decomposing human and animal remains. Experiments were conducted to study the effect of fluoxetine on developing D. maculatus using two‐drug administration models: a non‐living animal model (pork muscle) and a living one (Sus scrofa L. pigs). We assessed the duration of immature stages and total life cycle, as well as morphological parameters (body length, cephalic width, and weight). The effect of fluoxetine was studied at an overdose concentration: In the non‐living animal model the drug was mixed with macerated pork muscle (2000 mg/kg) and in the living animal model, pigs were given the drug orally (833 mg/kg). A control was used for each model. Daily observations were performed from the beginning to the end of the experiments. GC‐MS was used for drug detection and quantification. There were no statistically significant differences in the duration of immature stages, life cycle, larval mortality, morphological parameters, or sex ratio, between treatment and control, regardless of the drug administration model. Given that fluoxetine had no detectable effect on the development of D. maculatus, detection of this drug in forensic situations would not compromise the accuracy of PMI estimations.