Study of elastic fiber changes of human skin in distinction between antemortem and postmortem wounds

Elastic fiber changes of volunteers' antemortem and postmortem skin wounds of various time were observed in order to find possible differences between them. These sections of the wounds were stained by Hart's modification of Weigert's elastic tissue stain.. However, this study showed that there were no differences in the nature and distribution of the elastic fibers in the dermis of volunteers' antemortem and postmortem human skin wounds. Therefore, this suggests that the appearances of the elastic fibers in the dermis should not be as a means of differentiating antemortem skin wounds from postmortem wounds in forensic identification.     

Evaluation of histologic changes of the skin in postmortem period

ABSTRACT: Determination of the time of death is an important consideration in forensic practice. Many methods have been attempted to accurately and systematically determine the postmortem interval (PMI). Histologic examination of the skin or appendages is one of the methods tried by few researchers. However, no attempt had been made to analyze the histologic changes in the skin and appendages simultaneously and to compare them with PMI. We sequentially studied the histologic changes of the skin and appendages in the early PMI. The results of the present study show that the skin undergoes progressive morphological changes in the postmortem period. The epidermis and the dermis appeared normal for 6 hours after death, and after this period, degenerative changes began. By 6 to 9 hours after death, degeneration began in the dermis, and by the end of 18 hours, the dermis began to disintegrate. The sweat glands appeared normal for approximately 3 to 4 hours. For 18 hours after death, the sebaceous glands and hair follicles appeared normal, and after this period, degeneration began.     

Finger prints on human skin--results of a general applications-oriented series

Numerous methods have been described for making dactyloscopic traces visible on human skin, but these have never become routine--last but not least because they are too complicated and time-consuming to perform. The purpose of the present investigation was to find out to what extent fingerprints on the skin of deceased persons can be made visible with the help of conventional methods like iodine fuming or brushing with Magna-Brush and can be preserved with gelatine film or moulding material. Of the total number of 486 experimental fingerprints the dermal ridges could be made visible in 150 prints. The best findings were obtained when the trace had been applied several hours post mortem. On the skin of the extremities better results could be achieved than on the trunk or the neck. Dactyloscopic tracing on the skin of bodies in homicide cases should be taken into consideration especially if there is evidence that the perpetrator touched the victim after his/her death (e.g. if the body was transported).     

Myocardial hypertrophy induces carotid body hyperplasia

The carotid bodies tend to enlarge after long-standing cardiopulmonary disease. Our objective was to investigate whether cardiac hypertrophy is associated with carotid body hyperplasia. Fifteen autopsy cases with combined left and right ventricular hypertrophy were examined and compared with two control groups (16 cases). The study involved a meticulous dissection of carotid bifurcations, thin serial sections, and morphometric analysis of carotid body volume and cell types (progenitor, dark, light, and sustentacular). There was a significant increase in sustentacular cells in all individuals with cardiac hypertrophy, which was not drug-induced, and accompanied by a similar increase in carotid body volume. Dark or light cell accumulation was detected focally and only in three instances. It appears that the generalized sustentacular cell hyperplasia is the result of long-standing hypoxia, while a superimposed focal prominence of dark or light cells may be proliferative or metaplastic in nature and attributed to short-term hypoxia.     

小鼠皮肤切创愈合过程中M_3型乙酰胆碱受体的表达

目的 探讨小鼠皮肤切创愈合过程中损伤区M3受体的表达及其随时间的变化规律.方法 应用免疫组织化学染色和Western印迹技术检测小鼠皮肤切创后不同时间段M3受体的变化情况.结果 正常皮肤组织的表皮、毛囊、皮脂腺、汗腺、皮肌层等均表达M3受体.伤后6～12h,损伤区M3受体阳性细胞以多形核粒细胞为主;1～3d,M3受体阳性细胞以单个核细胞和成纤维细胞为主;5～14d,M3受体阳性细胞主要为成纤维细胞.阳性细胞率在伤后6～12h逐渐增高,12h达高峰,1～5d略有下降,但保持较高水平,7d阳性细胞率再次达到峰值,随后逐渐降低.通过Westem印迹法检测显示,各个时间段均有M3受体阳性条带,其中12h和7d为M3受体两个表达高峰.结论 多形核粒细胞、单个核细胞和成纤维细胞均表达M3受体,提示其可能在皮肤切创愈合过程中起重要的作用;M3受体表达的规律性变化可用于损伤时间的推断.     

男性上肢长骨的测量及其最大长推算

目的探讨用上肢长骨的残骨某一项指标建立肱骨、尺骨和桡骨最大长的回规方程,然后可根据所得值间接推算人体身高。方法选男性肱骨、尺骨和桡骨50例,左、右共100侧肢体。用人体测量仪器,按体质人类学测量方法进行各项指标测量,所得值经统计学分析后,分别与肱骨、尺骨和桡骨最大长建立直线回规方程。结果经相关分析建立了肱骨最大长回规方程17个,尺骨最大长回规方程8个,桡骨最大长回规方程11个。结论若能测得上肢长骨残骨的某一项指标,就可用所建立的回规方程推算该骨的最大长,这在法医学上具有一定的参考价值。     

Dielectric parameters of the tissues as additional criteria of postmortem period duration in medical examination of dismembered corpses

We studied dielectric indices of soft tissues from the parts of the dismembered corpses (skin, fragments of head, trunk extremities muscles) in terms of postmortem period duration. True (epsilon/) and false (epsilon//) parts of dielectric permeability at 10 cm wave length were determined. We obtained the curves characterizing changes in tissue dielectric parameters for 30 days after death. Thus, biophysical parameters of dismembered coupse fragments allow precise dating of death.     

Immunohistochemical study of the pattern of distribution of ABO blood group substances in male genitalia

The distribution of the ABH antigens was investigated in 11 different sections of the male genitalia in 53 autopsy cases; the peroxidase-antiperoxidase technique was used. Specific staining of the epithelia differed considerably among and between individuals. Nonsecretors showed a tendency toward less staining in the epithelia, whereas in the endothelia there was no difference. A2 cases could be recognized, as the endothelia were marked almost completely with anti-H. In A2B nonsecretor epithelia and endothelia, there was only a minimal reaction with anti-A and anti-H. Spermatozoa were irregularly stained in the ampulla of the vas deferens, whereas in the testis and epididymis no reaction could be found.     

Identification of a murder weapon by a peculiar blunt force injury pattern and histochemical analysis

Attempts to determine the instrument in the brutal killing of a middle-aged male resulted in the positive identification of an auto jack column as the actual instrument used. This was accomplished by the use of three modalities: (1) the edge of the jack column conformed exactly to a multi-curved laceration in the forehead (site of lethal injury), (2) blood found within this edge of the jack column afforded the same blood type as that of the victim, and (3) tissue sections made of the blood and debris from this edge of the jack column revealed tissue fragments containing human keratin (antihuman keratin technique) and positive staining with collagen stains.     

IL-33在小鼠皮肤创伤后损伤时间推断中的作用

目的通过观察白细胞介素-33(interleukin-33,IL-33)在皮肤创伤后的时序性变化规律,探讨IL-33在法医学实践中用于损伤时间推断的应用价值。方法利用直径为5mm的圆形锉刀在小鼠背部建造皮肤损伤模型,于伤后1h、3h、6h、12h、1d、3d、5d、7d、10d取损伤处组织,对照组在与创伤组小鼠相同部位取同等大小的皮肤样本。采用苏木精-伊红(hematoxylin-eosin,HE)染色法观察皮肤创伤后愈合过程中的形态学变化,通过Western印迹法、免疫组织化学染色和双重免疫荧光染色法检测皮肤创伤样本IL-33的表达变化。结果Western印迹法结果显示,伤后3h,IL-33蛋白表达稍有下降,6h后IL-33蛋白表达逐渐增加,于伤后3d达峰值,随后逐渐减少。免疫组织化学染色结果显示,在对照组皮肤的表皮、毛囊、皮脂腺及真皮中固有细胞有少量IL-33阳性表达,伤后3h,IL-33阳性细胞率开始增加,伤后3d达到峰值,随后逐渐减少。双重免疫荧光染色结果显示,伤后1~3d,IL-33阳性表达细胞主要为巨噬细胞,伤后5~7d,IL-33阳性表达细胞主要为肌成纤维细胞。HE染色结果显示该皮肤损伤模型创口愈合过程符合炎症的病理学发展规律。结论IL-33有望成为法医学推断皮肤损伤时间的参考指标。     

Suicidal ligature strangulation with an elastic band

An unusual case of self-strangulation with an elastic band is described. The victim was a young Hispanic male with a complicated psychiatric history, including suicide attempts. Mechanisms of strangulation and mechanical asphyxial death are discussed briefly.     

Fibronectin EIIIA splicing variant: a useful contribution to forensic wounding interval estimation

A fibronectin splicing variant, Fn containing an extra type III domain (EIIIA in rat, ED1 or EDA in human) has recently attracted more attention because of its sensitive response in injury of adult tissue. The characteristic that this form is absent in adult tissue while it is commonly expressed in fetal tissues and injured adult tissue is useful in estimation of injury interval in forensic science. The regulation of fibronectin splicing was studied by immunohistochemistry by using monoclonal antibody to EIIIA on sections from paraffin embedded rat skin sample after contusion. The results indicated that epidermic cells and hair follicle epithelium of rat skin were found positive staining at 6h after injury, and the color became darker with prolonged wounding time. Based on the above result, we invented a type of test paper assayed for EIIIA-Fn splicing variant by using immune colloidal gold technique. After dipping one end of test paper in the supernatant fluid of tissue homogenates of injury skin for few minutes, detecting line could be found. It showed that all experimental injured samples revealed positive staining; the darkness of positive staining was dependent on the injury time, while control normal skin cannot found positive staining. It is concluded that there is a close relationship between the expression of EIIIA-Fn splicing variant and wounding interval, and that the gold-labeled test paper can be useful in distinguishing ante- and post-mortem injury, and in estimation of wounding interval in forensic science.     

Determination of ABO antigens in fingernails using the APAAP (immunoalkaline phosphatase) technique

Fingernail specimens with adherent nail-bed were taken from autopsy material with blood groups A, AB, B and O. Frozen 4-5-microns sections were submerged and floated carefully during each working step. Portions of fingernails were contaminated with blood and buccal cells, respectively. Furthermore, fingernail fragments of 8 volunteers were embedded in a biocomponent adhesive according to Grieve and Kotowski (Forensic Sci. Soc., 26 29-34) (1986) and cut by the usual microtome technique. APAAP staining is a proper method for demonstrating blood group antigens in fingernails from groove to margin. Frozen sections as well as smallest specimen embedded in a suitable adhesive are applicable for staining procedures. Using freshly prepared artificial stains, blood group constellations of red blood cells and/or buccal cells adherent on the surface of fingernails may be distinguished from the nail matrix.     

Immunohistochemical studies on postmortem lividity

An immunohistochemical investigation of postmortem lividity was performed to illuminate localization of hemoglobin (Hb) and the mechanism of fixed lividity. The fixed lividity was defined as an unfading phenomenon by thumb finger pressure. Skin specimens were taken from 68 autopsy cases 7.5–336 h (2 weeks) postmortem. Localization of Hb of the specimens was examined by a labeled streptabidin biotin (LSAB) method using polyclonal (rabbit antihuman hemoglobin antibody) and monoclonal (mouse anti-human hemoglobin monoclonal antibody) antibodies. Positive staining for Hb was observed in various sites of the skin, i.e. in only intravascular erythrocytes, in vascular walls and perivascular tissue including sweat glands and sebaceous glands, in the dermal connective tissue, and in almost all of skin tissue except the horny layer. The diffusion of Hb into skin tissue was observed in 20 of 41 displaceable lividity cases (49%) and 11 of 27 fixed lividity cases (41%). Compared to displaceable lividity, superficial plexi in fixed lividity were filled with erythrocytes, which were markedly immunodetected. These findings support the hypothesis that the fixation of lividity is not due to diffusion of Hb into skin tissue but hemoconcentration in blood vessels.     

Recovery and evaluation by cytologic techniques of trace material retained on bullets

Fragments of tissue, intermediate targets, and debris related to firing are embedded in the fine striations and deforming edges of bullets. Because most of these fragments are too small to visualize and process as histologic sections, this material is usually washed away when the projectiles are cleaned following removal at autopsy. By preserving the rinsing material that results from routine cleaning of projectiles, it may be possible to evaluate adherent material from the bullet by cytologic techniques, including filter preparations, cell blocks, and smears of macroscopic tissue fragments. Bullet-wash cytology produced cellular elements, tissue fragments, and inert material from intermediate targets. Different tissue elements could be documented with a given projectile; this information could be utilized to document the path of a bullet through the body or intermediate target. This initial study suggests that low- and high-velocity projectiles produce different types of tissue debris, with much more fragmentation and scarcity of cellular components in the high-velocity rounds. Inert material, resulting from intermediate targets, such as clothing, as well as gunshot residue on the bullet or debris from the barrel could be distinguished on preparations. There was a difference in tissue representation of adherent material on the bullet; connective tissue, mesothelial coverings, and fragments from organs with higher elastic and cohesive properties were seen with much greater frequency on the filters than were loosely cohesive and friable organs such as liver and spleen. The cytologic preparations from projectile washings reflect both the path taken by the bullet and the ballistic damage to the organs. Thus, the cytologic evaluation of bullet washings may be useful in the incorporation of gunshot wound evaluation to support documentation of the trajectory of the projectile.     

脑干损伤后神经元及轴突改变的组织化学观察

采用针刺法造成大鼠脑干损伤,用尼氏体染色、嗜银染色和改良三色法观察脑干神经元及轴突在伤后不同时间的病理改变。结果发现,嗜银染色显示伤后 1～ 3h部分神经纤维不规则增粗、少数断裂, 6h断端膨大呈球形, 15h收缩球较为明显,至 24h收缩球明显且数量增多;改良三色法显示伤后 3～ 6h部分髓鞘与轴突之间的间隙增宽, 15h髓鞘明显弯曲、不完全地附着在轴突表面,甚至剥脱,持续到伤后 24h;尼氏体染色显示神经元核周尼氏体在伤后 24h减少。该结果提示,组织化学染色能观察到脑干损伤后的病理改变,并且有可能用于推断脑干损伤时间。     

Image analysis of gunshot residue on entry wounds. I--The technique and preliminary study.

An automated image analysis (IA) technique has been developed to obtain a measure of the amount (i.e. number and area) of gunshot residue (GSR) particles within and around a gunshot wound. Sample preparation and IA procedures were standardised to improve the reproducibility of the IA measurements of GSR. Measurements of GSR from test firings into goat hide were enhanced by staining the barium and lead components present on the skin sections with Alizarin Red S. The amount of GSR detected on the stained skin sections was compared with backscatter electron micrographs of the same sections. The differences were deemed to be insignificant when the variability in the repeated test firings were taken into consideration. Preliminary results indicated that the decreasing relationship between firing range and the amount of GSR deposited was non-linear, and that for firing ranges of up to 20 cm the amount of GSR deposited from repeated shots fired from the same distance was highly variable.     

Image analysis of gunshot residue on entry wounds: I – The technique and preliminary study

An automated image analysis (IA) technique has been developed to obtain a measure of the amount (i.e. number and area) of gunshot residue (GSR) particles within and around a gunshot wound. Sample preparation and IA procedures were standardised to improve the reproducibility of the IA measurements of GSR. Measurements of GSR from test firings into goat hide were enhanced by staining the barium and lead components present on the skin sections with Alizarin Red S. The amount of GSR detected on the stained skin sections was compared with backscatter electron micrographs of the same sections. The differences were deemed to be insignificant when the variability in the repeated test firings were taken into consideration. Preliminary results indicated that the decreasing relationship between firing range and the amount of GSR deposited was non-linear, and that for firing ranges of up to 20 cm the amount of GSR deposited from repeated shots fired from the same distance was highly variable.     

Dermatoglyphic examination of the dermal surface of bodies in advanced postmortem condition

A new technique was applied to examine dermatoglyphic characteristics in dead bodies in advanced postmortem conditions. For this purpose, the volar skin was first fixed in formalin, incubated in 1 N potassium hydroxide solution, and then the dermis was exposed. Dermatoglyphic features were inspected on the dermal surface by staining with toluidine blue solution. This technique may be useful in cases in which the regular examination process does not provide favourable results because of advanced decomposition of the skin.     

Forensic medical assessment of the mechanisms of development of gunshot lesions caused by elastic destructive agents

This paper reports the results of analysis of the data obtained in experimental studies and practical expert assessments of body injuries inflicted by rubber balls for traumatic weapons. The causes accounting for the polymorphism of such injuries and the mechanisms of their development were elucidated by means of damage simulation taking into consideration the physical and dynamic properties of elastic ball-type destructive agents and the morphological structure of different anatomical regions of the human body. The results of the study may be of interest for differential diagnostics of gunshot lesions caused by elastic destructive agents.