Intrapulmonary aquaporin-5 expression as a possible biomarker for discriminating smothering and choking from sudden cardiac death: a pilot study

The diagnosis of mechanical asphyxia as a cause of death, especially smothering and choking lacking evident injury, is one of the most difficult tasks in forensic pathology. The present study investigated the intrapulmonary expressions of aquaporins (AQPs; AQP-1 and AQP-5), as markers of water homeostasis, in forensic autopsy cases (total n=64, within 48 h postmortem) of mechanical asphyxiation due to neck compression (strangulation, n=24), including manual/ligature strangulation (n=12) and atypical hanging (n=12), smothering (n=7) and choking (n=8), compared with sudden cardiac death (n=14) and acute brain injury (n=11). Quantification of mRNA using a Taqman real-time PCR assay system demonstrated suppressed expression of AQP-5, but not AQP-1, in smothering and choking, compared with that in strangulation as well as sudden cardiac death and acute brain injury death. Immunostaining of AQP-5 was weakly detected in a linear pattern in the type I alveolar epithelial cells in smothering and choking cases, while cardiac and brain injury death showed marked positivity, and most strangulation cases had AQP-5-positive granular aggregates and fragments in intra-alveolar spaces. These observations indicate a partial difference in pulmonary molecular pathology among these causes of death, suggesting a procedure for possible discrimination of smothering and choking from sudden cardiac death.     

死亡方式对大鼠DNA降解影响的图像分析研究

探讨不同的死亡方式对组织细胞核 DNA 降解的速率是否存在影响。选取20只大鼠随机分为4组,分别采用失血性休克、断颈、溺死及扼死等4种方式处死,每2 h 取材一次(脑、脾、肝组织),Carnoy 液固定,VANS 改良法染色,选取7个指标进行图像分析,数据经一元回归及多元回归统计处理,对不同死亡方式组的一元回归方程进行多组间分析。结果显示,7个指标与死亡时间明显相关,但在不同死亡方式组间各指标相关性存在差异,一元回归方程比较显示,溺死组与其他组肝组织 ID、AOD、LDC 3个指标存在差异,显示其 DNA 降解较慢,脾脏在溺死组 A、MD、ID、AOD、LDC、AG 等6个指标以及失血性休克组 MD、ID、AOD、AG 等4个指标与其他组间存在明显差异,而脑组织在不同组间则差异较小。多元回归分析进一步印证了上述差异。在失血性休克、溺死、断颈及扼死致死的尸体间其组织细胞 DNA 降解速率存在差异,其原因可能与淤血程度及尸体所处环境有关。在本实验条件下,脑是受影响最小的器官,而脾是较易受影响的器官。     

2633例机械性窒息法医尸检资料回顾性研究

本文根据湖北省部分地区1957～1986年间尸检记录,收集并分析了2633例机械性窒息死的出现率、案情性质、城市与乡村的差别等问题,为法医学实践提供了可供参考的资料。     

Quantitative assessment of brain hydration in determination of death speed and type of tanatogenesis in forensic medical practice

Brain hydration was determined in death of strangulation mechanical asphyxia, acute alcoholic poisoning, acute poisoning with opiates, cancer of stage IV, coronary heart disease with acute heart failure, hemorrhagic stroke. Brainstem edema (BSE) occurred in 69.2% cases (upper BSE - 20.2%, lower BSE - 17.3%, BSE of the all parts - 31.7%). BSE was present in all cases of opiate poisoning; 52.9% cases of hemorrhagic strokes, 61.3% cases of coronary heart disease. The data obtained show prevalence of brain tanatogenesis in death of the above diseases. Hypohydration and hyperhydration of the brain were observed in short and slow agony, respectively.     

Evaluation of postmortem serum calcium and magnesium levels in relation to the causes of death in forensic autopsy

There appears to be very poor investigation of postmortem serum calcium (Ca) and magnesium (Mg) for diagnostic evidence to determine the cause of death. The aim of the present study was a comprehensive analysis of the serum levels in relation to the causes of death in routine casework. Autopsy cases (total, n=360; 5-48 h postmortem), including blunt injury (n=76), sharp injury (n=29), asphyxiation (n=42), drownings (n=28: freshwater, n=11; saltwater, n=17), fire fatalities (n=79), methamphetamine (MA) poisoning (n=8), delayed death from traumas (n=37), and acute myocardial infarction/ischemia (AMI, n=61), were examined. In total cases, there was no significant postmortem time-dependent rise in serum Ca and Mg. Both Ca and Mg levels in the heart and peripheral blood were significantly higher in saltwater drowning compared with those of the other groups. In addition, a significant elevation in the Ca level was observed in freshwater drowning and fire fatalities, and in the Mg level in fatal MA intoxication and asphyxiation. Topographic analyses suggested a rise in serum Ca and Mg due to aspirated saltwater in drowning, that in serum Ca in freshwater drowning and fire fatalities of peripheral skeletal muscle origin and that in serum Mg in MA fatality and asphyxiation of myocardial and/or peripheral origin. These markers may be useful especially for diagnosis and differentiation of salt- and freshwater drownings and may be also helpful to determine the causes of death involving skeletal muscle damage, including burns and MA intoxication.     

Single-stranded DNA as an immunohistochemical marker of neuronal damage in human brain: an analysis of autopsy material with regard to the cause of death

Single-stranded DNA (ssDNA) is a marker of apoptosis and programmed cell death, which appears prior to DNA fragmentation during delayed neuronal death. The present study investigated the immunohistochemical distribution of ssDNA in the brain to investigate apoptotic neuronal damage with regard to the cause of death in medicolegal autopsy cases (n=305). Neuronal immunopositivity for ssDNA was globally detected in the brain, independent of the age, gender of subjects and postmortem interval, and depended on the cause of death. Higher positivity was typically found in the pallidum for delayed brain injury death and fatal carbon monoxide intoxication, and in the cerebral cortex, pallidum and substantia nigra for drug intoxication. For mechanical asphyxiation, a high positivity was detected in the cerebral cortex and pallidum, while the positivity was low in the substantia nigra. The neuronal ssDNA increased during the survival period within about 24h at each site, depending on the type of brain injury, and in the substantia nigra for other blunt injuries. The neuronal positivity was usually lower for drowning and acute ischemic disease. Topographical analysis of ssDNA-positive neurons may contribute to investigating the cause of brain damage and survival period after a fatal insult.     

Central monoamines and the death process time (antemortem time) during asphyxia. An experimental study in the mouse brain

The changes of the brain monoamines, norepinephrine (NE), dopamine (DA), and serotonin (5-HT), during acute asphyxia, caused by strangulation, anoxia, and drowning, were studied in the mouse. In several asphyxiated animal groups significant linear correlation was found between the level of monoamines, NE, DA, and 5-HT, and the death process times or antemortem times were r = 0.50, 0.98 (P less than 0.05), and 0.57, respectively. It is concluded that the level of brain NE and DA increased in the mouse that died of asphyxia, and the level of 5-HT showed only an apparent decrease in anoxia groups as compared with the control group and showed a twice as high increase in drowning groups. Especially, there was a tendency that the longer the death process times or antemortem times, the higher was the level of DA.     

Toxicological findings in victims of traumatic deaths.

The toxicological findings from 6037 analyses of viscera obtained from victims of traumatic death are used to correlate the relative incidence of carbon monoxide, ethyl alcohol, narcotics, hypnotics, analgesics, and tranquilizers-antidepressants in deaths occurring under the following circumstances: fire related, asphyxia by hanging, by use of plastic bags, from physical obstruction of trachae, and by drowning; traumatic injury from impact of moving train, fall from height, and occupational accident; traumatic injury to pedestrian, driver, and passenger from vehicular accidents; and from violent death by shooting, stabbing, strangulation, and beating. The influence of alcohol, narcotic drugs, and tranquilizers on carbon monoxide can be seen in some of these traumatic deaths. Ethanol alone and in combination with other drugs was present in 42.3% and 19.5% of driver and pedestrian victims, respectively, of vehicular accidents in the year 1974. Comparative analysis is presented for the toxicological data obtained on victims of homicide (shooting, stabbing, strangulation, and beating) in New York City and similar data reported for victims of homicide in Detroit. In New York City 45.9% of such victims died while under the influence of alcohol or narcotic drugs, or both, with methadone predominating in the latter category. Tissue concentrations of drugs found in victims of traumatic death are presented. Diphenylhydantoin, diazepam, meperidine, and slow-acting barbiturates were found in normal therapeutic levels. Higher concentrations of amitriptyline, chlorpromazine, propoxyphene, short-acting barbiturates, and methadone were observed. The concentration of methadone in blood and brain (0.13 +/- 0.14 mg/100 ml) and in liver (0.53 +/- 0.42 mg/100 ml) in cases of traumatic death are not different from those observed in deaths classified as due to methadone overdose.     

Morphologic determinants of asphyxia in lungs: a semiquantitative study in forensic autopsies

Asphyxia is a name given to different kinds of lesions that can produce similar histologic findings. Thus, because of the varied nature of the different kinds of lesions, as well as the incidence of similar qualitative histologic findings with different causes, the aim of this work was to study special kinds of injuries with particular subsequent impairment. These include some diagnostic problems of sudden death of natural causes, including aspiration, suffocation, drowning, and strangulation. Ranking was made of 167 victims based on the diagnosis as having: aspiration (n = 35), suffocation (n = 88), drowning (n = 27), and strangulation (n = 17). Stepwise discriminant analysis of the resulting data showed that lung necropsies from victims of these four events could be distinguished from one another. Statistical differences among the four groups were observed for eight morphologic parameters. A robust discriminant function permitted an adequate classification of the four groups of disease in 85.03% of the cases. Lung autopsies with congestion, septal hemorrhage, and foreign body showed a specificity of 100% for victims of aspiration, whereas ductal overinsufflation, interstitial edema, and bronchiolar constriction showed a specificity of 81.8% in victims of suffocation. Intraalveolar edema and dilatation of the alveolar spaces with secondary compression of the septal capillaries characterized drowning. Victims of strangulation showed a strong alveolar hemorrhage, with alveolar collapse and overinsufflation, associated with bronchiolar dilatation. It is concluded that semiquantitative analysis of lung autopsies might be a useful supplementary histologic criterion to support the diagnosis of asphyxia.     

Thyreoglobulin and violent asphyxia

The concentration of thyreoglobulin (tg) was determined for death caused by hanging, strangulation by ligature, and throttling. Cases of sudden death (traumatic aortic rupture, penetrating wounds of the heart) were used for comparison. The mean values in cases of hanging (149.9±202.3 ng/ml), strangulation by ligature (193.1±173.3), manual strangulation (561.6±173.9) are distinguishable from violent acute deaths (23.3±27.6) and living healthy individuals (17.3±16.1). By means of statistical comparisons, significant differences were found between throttling and strangulation by ligature and between throttling and hanging (adjusted P<0.001). In connection with examination of the bodies high tg values can be regarded as a vital reaction in obstructive asphyxia.     

怀疑原发性脑干损伤早期死亡脑干纤维联结蛋白的免疫组化研究

在本研究的１３个案例中，怀疑原发性脑干伤死亡的５例，明确死因的８例，其中严重闭合性颅脑损伤２例；缢死１例，失血性休克１例，电击２例，海洛因中毒２例。用ＬＳＡＢ法对１３例脑干的中脑、脑桥、延髓各部ＦＮ进行检测。结果显示５例怀疑为原发性脑干伤、２例严重颅脑损伤、２例海洛因中毒死者的脑千部位的神经元内均可见ＦＮ的异常沉积，其它各例未见ＦＮ的异常沉积。结果表明；ＬＳＡＢ－ＦＮ法是诊断原发性脑干伤早期死亡灵敏但非特异的形态学指标。     

Cervical Arterial Injury After Strangulation—Different Types of Arterial Lesions

After strangulation, cervical arterial injuries (CAI) are uncommon. We report three unusual cases where strangulation induced immediate stroke. CAI were examined using brain CT scan and Doppler ultrasonography in the three cases and then by autopsy in one of the victims. One of the two victims who survived the attempted strangulation had a unilateral carotid dissection, whereas in the other victim, no arterial dissection or thrombosis was observed. As regards the deceased victim, the autopsy confirmed the bilateral dissection showed on CT scan and Doppler ultrasonic examination and revealed that both carotid arteries were dilated up to two times the normal diameter. Microscopic examination showed a major bilateral hemorrhagic dissection of the media with obliterating fibrous endarteritis lesions associated with inflammatory damage. CT scan with arteriography does not demonstrate all the different types of arterial injury, particularly atheromatous embolism, direct compression, or prolonged spasm. Thus, traditional autopsy remains an essential forensic tool after strangulation to show the type of CAI.     

Postmortem Diagnosis of Fatal Hypothermia by Fourier Transform Infrared Spectroscopic Analysis of Edema Fluid in Formalin-Fixed,Paraffin-Embedded Lung Tissues

The goal of this study was to investigate whether pulmonary edema could become a specific diagnostic marker for fatal hypothermia using Fourier transform infrared (FTIR) spectroscopy in combination with chemometrics. The spectral profile analysis indicated that hypothermia fatalities associated with pulmonary edema fluid contained more β-sheet protein conformational structures than the control causes of death, which included sudden cardiac death, brain injury, cerebrovascular disease, mechanical asphyxiation, intoxication, and drowning. Subsequently, the results of principal component analysis (PCA) further revealed that the content of β-sheet protein conformational structures in the pulmonary edema fluid was the main discriminatory marker between fatal hypothermia and the other causes of death. Ultimately, a robust postmortem diagnostic model for fatal hypothermia using a partial least-squares discriminant analysis (PLS-DA) algorithm was constructed. Pulmonary edema fluid spectra collected from eight new forensic autopsy cases that did not participate in the construction of the diagnostic model were predicted using the model. The results showed the causes of death of all these eight cases were correctly classified. In conclusion, this preliminary study demonstrates that FTIR spectroscopy in combination with chemometrics could be a promising approach for the postmortem diagnosis of fatal hypothermia.     

Six‐Year Retrospective Study of Suicidal Hangings: Determination of the Pattern of Limb Lesions Induced by Body Responses to Asphyxia by Hanging*

Abstract: The objective of the present study was to estimate the proportion of hanging victims presenting with limb lesions, to compare this rate between hanging in restraint spaces and in more open settings, and to describe the usual pattern of limb lesions associated with hanging. Two hundred and seven cases of suicidal hanging were retrospectively reviewed and compared to 45 homicidal nonhanging strangulation victims. Bruises incidence was significantly lower in hanging victims (19.8%) compared to homicidal strangulation victims (55.6%). Bruises were more commonly encountered in restraint areas such as closets and staircases (56.3% and 66.7%, respectively) than in more open settings such as barn, bridge, fence, and park. Limb bruises on hanging victims were generally located on the posterior upper limb or the anterior lower limbs, whereas strangulation victims did not display this preferential bruises concentration. Possible suspicion criteria for limb bruises distribution are discussed, in relation to physiopathology of human asphyxia by hanging.     

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.     

Autoerotic fatalities in Greater Dusseldorf

Autoerotic fatalities in the Greater Dusseldorf area correspond to the relevant medicolegal literature. Our results included exclusively young to middle-aged, usually single men who were found dead in their city apartments. Clothing and devices used showed a great variety. Women's or fetish clothing and complex shackling or hanging devices were disproportionately frequent. In most cases, death occurred due to hanging or ligature strangulation. There was no increased incidence of underlying psychiatric disorders. In most of the deceased no or at least no remarkable alcohol intoxication was found. Occasionally, it may be difficult to reliably differentiate autoerotic accidents, accidents occurring in connection with practices of bondage & discipline, dominance & submission (BDSM) from natural death, suicide or homicide.     

Homicidal asphyxia

Homicides due to asphyxia are relatively uncommon. To better understand the presentation of such cases, the files of the Bexar County Medical Examiner's Office were reviewed from January 1, 1985, through December 31, 1998, for all such homicides. A total of 133 cases were found. The largest category was ligature strangulation with 48 deaths (21 male, 27 female). Petechiae were present in the conjunctivae and/or sclerae in 86% of the cases; fractures of the hyoid and/or thyroid cartilage were present in 12.5%. There were a total of 41 deaths from manual strangulation (27 female, 14 male). Petechiae were present in 89% of the cases. In cases of manual strangulation, fractures of the hyoid, thyroid, or cricoid cartilage were found in all the male victims and slightly more than one half of the female victims. Twenty-six cases of suffocation were found; 20 of the victims were < or =2 years of age. Only 1 of these children had petechiae and/or scleral hemorrhage. Five deaths were due to choking. Three of the deaths involved adults who were gagged; 2 deaths involved infants with foreign material pushed into the mouth. Other categories of asphyxia were as follows: 9 deaths due to more than one form of asphyxia; 1 death due to hanging, and 3 deaths due to drowning. Rape was the motive in 66% of the female victims of ligature strangulation and 52% of those due to manual strangulation.     

Classification of Asphyxia: The Need for Standardization

Abstract: The classification of asphyxia and the definitions of subtypes are far from being uniform, varying widely from one textbook to another and from one paper to the next. Unfortunately, similar research designs can lead to totally different results depending on the definitions used. Closely comparable cases are called differently by equally competent forensic pathologists. This study highlights the discrepancies between authors and tries to draw mainstream definitions, to propose a unified system of classification. It is proposed to classify asphyxia in forensic context in four main categories: suffocation, strangulation, mechanical asphyxia, and drowning. Suffocation subdivides in smothering, choking, and confined spaces/entrapment/vitiated atmosphere. Strangulation includes three separate forms: ligature strangulation, hanging, and manual strangulation. As for mechanical asphyxia, it encompasses positional asphyxia as well as traumatic asphyxia. The rationales behind this proposed unified model are discussed.     

Axonal injury – a diagnostic tool in forensic neuropathology?: A review

We used β-amyloid precursor protein (β-APP) to investigate our own forensic neuropathological case material (n=252) in light of the current literature on the phenomenon “axonal injury” (AI) to determine the incidence, specificity and biomechanical significance of AI and its significance for determining vitality and survival time. The case material consisted of cases of fatal nonmissile closed-head injury (n=119), gunshot injury (n=30), fatal cerebral ischemia/hypoxia (n=51), brain death caused by mechanical trauma (n=14) or nonmechanical injury (n=18), and acute hemorrhagic shock (n=20). AI was observed in 65% to 100% of cases of closed-head injury, fatal cerebral ischemia/hypoxia, and brain death with a survival time of more than 3 h; AI could not be detected in the cases of acute hemorrhagic shock. A statistically significant difference between traumatically and nontraumatically induced (nondisruptive) AI was not found. There was no statistical evidence of a correlation between AI and the different types of external force, since AI could be demonstrated after both acceleration/deceleration injuries and traumatic impact. Therefore, biomechanical inferences for reconstruction purposes are not possible. On the other hand, β-APP was found to be a definite marker of vitality. In our material, cases with a posttraumatic interval of under 180 min did not express β-APP. Moreover, the literature shows that the posttraumatic interval can be determined by other methods for demonstration of AI such as by ubiquitin immunostaining (360 min), silver staining (15–18 h), hematoxylin and eosin staining (about 24 h), or by demonstration of a microglial reaction (about 4 to 10 days) or of a few remaining isolated bulbs, without accompanying fibers, which can be detected after a survival time of up to 17 months.     

A contribution to a possible differentiation between SIDS and asphyxiation

The singular and combined appearance of conjunctival petechiae, of acute pulmonary emphysema and of signs of aspiration was evaluated in resuscitated and non-resuscitated children dying of SIDS (n=115), of other causes of natural death (n=17), of severe head injury (n=10) and of asphyxiation/strangulation (n=7). Conjunctival petechiae occurred in all of the asphyxiated victims and in five out of 10 children dying of severe head injury, but were exclusively found in four resuscitated babies and one baby with questionable resuscitation trials of the SIDS-group (4%), furthermore in one resuscitated child dying of a congenital heart defect. Acute pulmonary emphysema was detected in six out of the seven children of the asphyxiation/strangulation group, in two resuscitated children with head injury and in five resuscitated babies dying of SIDS. Both parameters were observed exclusively in the asphyxiation/strangulation group (71% of the cases) but not in the control cases. Therefore, it can be concluded that the simultaneous appearance of conjunctival petechiae and of acute pulmonary emphysema strongly indicates death by asphyxiation.