Magnesium, potassium, sodium and calcium in post-mortem vitreous humour from humans

Levels of magnesium, potassium, sodium and calcium in post-mortem vitreous humour from human controls, fire fatalities and drowning victims have been determined. The effects of time-related internal changes, external environmental parameters and different causes of death are evaluated. Despite the positive correlation and marked increase of potassium and, to a lesser extent, of magnesium and calcium with the length of the post-mortem interval, individual biological variability severely limits the usefulness of predictions of post-mortem interval based on electrolyte metal data. At best, there is only a 2/3 chance of a prediction being within 12 h of the true value. Vitreous humour metal concentrations are affected by external influences, such as the elevated temperatures of fires which increase the rate of release of intracellular magnesium and potassium. In cases where drowning is suspected, establishment or exclusion of this cause of death is not possible on the basis of vitreous humour electrolyte metal data because of possible post-immersion diffusion across the permeable membrane of the eyeball. It appears, however, that magnesium in salt-water cases and sodium in fresh-water cases are related, albeit erratically, to the length of the immersion period.     

Frequency and severity of injuries in correlation with the height of fall

The main aim of this study was to examine the correlation between the height of fall and the frequency, extensiveness, and type of injuries of certain body regions and organs. The specific objective was to determine characteristic injuries of the analyzed body regions in relation to the certain height of fall. The study included 660 cases of fatal falls from height (469 males and 191 females). Results support the hypothesis that the frequency and extent of the injured body regions and organs are related to the fall height. Head injuries are characteristic of the falls from heights up to 7 m and beyond 30 m. Brain injuries in high falls from heights beyond 30 m show an absence of contre coup contusions and macroscopically evident intracranial bleeding. The extensiveness of chest injuries is significantly statistically associated with fall height. In cases of high falls, the frequency of abdominal injuries is not significantly statistically related to the height of fall. Liver injuries are the most common abdominal injury and the critical height of fall at which the liver injury occurs is 15 m. Injuries of liver and spleen are concomitant in high falls from heights beyond 24 m, irrespective of the manner of impact. The height of fall over 15 m appears to be a reasonable boundary height beyond which the injuries of two or three body regions are generally associated.     

The strength, biochemical and biophysical properties of the skin in the simulation of injuries

The results of experimental investigation on determination of stress-strain and resistant skin properties, its plastic elements (collagenous proteins, proteoglycans, glycoproteins) and steam permeability in lesion modelling are presented.     

Immunohistochemical detection of fibronectin and tenascin in incised human skin injuries

Immunohistochemical detection of molecules involved in inflammatory reaction can be useful for the diagnosis of vitality in skin wounds. We studied the expression of fibronectin (FN) and tenascin (TN) in 58 human skin wounds (48 vital and 10 postmortem). The age of vital injuries ranged from 3 min to 8 h and postmortem specimens were collected after a postinfliction interval of 15-180 min. One hundred thirty-seven formalin-fixed paraffin-embedded sections (mean: 2.3 sections per case) were stained with each of two monoclonal antibodies against FN and TN using the streptABC technique. A reticular staining for FN in wound edge and dermis was observed in 50% of vital specimens versus 0% in postmortem cases. Immunoreactivity was reduced in 10 autolysed cases. FN positivity exclusively at the injury margin was observed in 39.4% of vital wounds and 10% of postmortem cases. TN was negative in all specimens. Vital and postmortem hemorrhage areas showed positivity for FN and TN. Due to its low sensitivity, immunohistochemical analysis of FN is useful for determining vitality only in a minority of cases. Different factors in everyday practice, including autolysis and technical problems often produce false negative reactions with the result that FN cannot be regarded as a reliable parameter of vitality. Positive reactions (network staining) are more valuable than negativity but are not pathognomonic. Both vital and postmortem hemorrhages show an enhanced positivity for FN and TN, thus impeding the diagnosis.     

An improved method for restoring the initial appearance of injuries on the skin

Presents a modified method for restoring the shape and size of wounds on skin preparations. The advantages of the modification over the routine A. N. Ratnevski?'s method are enumerated.     

Electrical and thermal injuries in pig skin — Evaluated and compared by light microscopy

The morphology of pig skin after electrical (el) and thermal exposure was studied in order to find methods applicable for disclosing electrical torture.Biopsies from pig skin exposed 24 hours earlier to either heat or electrical current under general anesthesia were studied by light microscopy. The amount of energy used of either type ranged from about 6 to about 100 joule deposited on two circular areas of the skin measuring 12 mm in diameter.In sections stained with hematoxylin and eosin alterations were found in heat-influenced specimens following the administration of moderate and large doses of energy. Changes were observed in el-influenced specimens also after the administration of low amounts of energy, which did not lead to macroscopical changes in the skin. The two types of energy induced different patterns of alterations inside the epidermis. The most characteristic change following heat exposure was the presence of a granular or fibrillar eosinophilic cytoplasm and subepidermal clefts, while el-expoure often produced white homogeneous cytoplasm and shadowy nuclei (“white necrosis”) in the attached epidermis. The individual changes could be produced by both types of injury, but to a highly different degree. However, the alteration classified as “vesicular nuclei” was only observed in el-damaged skin. The dermis from the more severely injured skin of both groups showed a homogeneous appearance (“necrosis”). While the changes of epidermis and dermis in response to heat were diffusely distributed, the changes created by electrical injury were often present in segments. By electrical damage homogeneous areas with loss of stainability and shadowy nuclei were occasionally observed in sweat glands, hair sheaths and in vessel walls, structures which are suggested to serve as conductors for the electrical current. “Vesicular nuclei” were observed in similar structures.Some of the findings may be associated with differences in intensity of energy during exposure to heat and electricity. Furthermore, the existence of different biological patterns following the two types of exposure should be considered. The studies are being continued to elucidate these basic questions, and to study further the medical diagnostic potential of examining skin biopsies from tortured individuals.     

尸体心血红细胞ATP降解规律与早期死亡时间的相关性

目的观察早期死亡时间（PMI）与血液红细胞ATP含量的相关性。方法选择具有确切死亡时间的尸体30例,在死亡后6、8、10、12、14、16、18、20、22、24h分别于第4肋间进行心脏穿刺取血,利用生物发光法检测血液样本红细胞ATP含量（μmol／gHb）,并观察红细胞ATP含量变化与死亡时间的关系。结果尸体心血红细胞ATP含量在死亡后1～24h之内呈现非匀速下降趋势,与死亡时间的Pearson相关系数为-0．971（P=0．000）;尸体心血红细胞ATP含量与死亡时间的回归方程及尺。值为：Y=-0．096X＋2．872（x为死亡时间）,R2=0．936,P=0．000。结论尸体心血红细胞ATP含量在死后1—24h之内的变化与死亡时间具有相关关系,可以作为法医学死亡时间推断的生物学指标。     

切创后细胞自噬及炎症因子的表达与损伤时间的关系

目的观察小鼠皮肤切创后不同时间细胞自噬与炎症细胞因子的变化,同时探讨这些变化与损伤时间之间的关系。方法采用RT-PCR及West-blot方法检测小鼠皮肤切创组织在不同时间Beclin-1、LC-3、IL-1α、IL-1β、MCP-1的基因表达及蛋白表达。结果皮肤切创后早期IL-1α、IL-1β基因的表达及蛋白表达水平有所升高,12小时达到最高值,而后呈下降的趋势;MCP-1的表达在损伤后6h开始升高,48h达到最高值,72h有所下降,而Beclin-1、LC3基因及蛋白表达在组织损伤后6h开始升高,24h到达到最高值而后下降。结论小鼠皮肤组织切创后细胞自噬的启动及自噬的最高值明显晚于炎性细胞因子的启动及炎症因子表达的最高值,实验发现当细胞自噬水平达到最高时,炎症因子的水平则开始表现为下降的趋势。这可能是随着切创组织中炎症因子释放的增多激活了细胞的自噬,而当自噬水平达到一定的程度又抑制过度的炎症反应。自噬与炎症因子的表达随着小鼠皮肤创面损伤后不同时间呈现出一定的变化规律,这为组织损伤后损伤的时间推断提供一定的参考。     

Device and methods for the measurement of energy transfer in experiments involving thermal and electrical injuries of skin

This work is part of a larger investigation aiming at tracing differences between injuries caused by heat and electricity. Electrodes and heaters similar to the electrodes of an electric cattle baton are used to dissipate approximately 40 joules in 40 seconds in pig skin.Voltages in the range 40–60 volts (AC or DC) are applied via stainless steel electrodes and temperatures in the range 50–100 °C are applied via heaters made of copper wire. Heat transfer is controlled by electronically regulated heaters utilizing the temperature dependence of the heater wire itself as a thermometer.Transfer of electricity takes place from either commerical DC supply, from transformed voltage from the mains or from a sine voltage generator connected to a power amplifier. The energy transfer is in all cases measured by electronic integration of the dissipated power in time. The power supplied to the electrodes or the heaters is found by electronic multiplication of the applied voltage and current.Typical power vs. time curves are presented.     

Diagnosis of electrical skin injuries. A review and a description of a case.

This paper presents a brief review of the results of research in the area of electrical skin injuries. It also includes a case report of a 5-year-old girl noted on her admission to the hospital to have injuries to the skin of her chest and left arm. Histological examinations demonstrated that the skin lesions were segmental and showed necrosis and inflammation. Deposits of calcium salts distinctly located to collagen fibers were observed below the regenerated epidermis at the periphery of two skin lesions of the chest wall, in the lower part of dermis at the periphery of a skin lesion of the left arm, and within connective tissue adjacent to elastic arteries and peripheral nerves from the thoracic cavity. The pattern of calcification localized to collagen fibers and situated both superficially and deeply in the skin in a zone of viable tissue close to necrotic tissue is characteristic of electrically induced lesions. Although there have been reports of deposition of calcium salts on collagen fibers after application of calcium salts in high concentration at the skin surface, the collagen calcification in the pattern observed in this patient is probably diagnostic of electrical injury.     

Optical 3D surface digitizing in forensic medicine: 3D documentation of skin and bone injuries

Photography process reduces a three-dimensional (3D) wound to a two-dimensional level. If there is a need for a high-resolution 3D dataset of an object, it needs to be three-dimensionally scanned. No-contact optical 3D digitizing surface scanners can be used as a powerful tool for wound and injury-causing instrument analysis in trauma cases. The 3D skin wound and a bone injury documentation using the optical scanner Advanced TOpometric Sensor (ATOS II, GOM International, Switzerland) will be demonstrated using two illustrative cases. Using this 3D optical digitizing method the wounds (the virtual 3D computer model of the skin and the bone injuries) and the virtual 3D model of the injury-causing tool are graphically documented in 3D in real-life size and shape and can be rotated in the CAD program on the computer screen. In addition, the virtual 3D models of the bone injuries and tool can now be compared in a 3D CAD program against one another in virtual space, to see if there are matching areas. Further steps in forensic medicine will be a full 3D surface documentation of the human body and all the forensic relevant injuries using optical 3D scanners.     

人体皮肤切创纤维连接蛋白EDA、EDB的表达与损伤时间关系的研究

目的研究纤维连接蛋白(fibronectin,FN)可变剪接片段EDA、EDB在人体皮肤切创的表达情况,并摸索EDA、EDBmRNA在离体皮肤上最长检出时限,以期为早期损伤时间的推断提供实用的参考指标。方法采用DIG标记的反意RNA探针,原位杂交检测人体皮肤在损伤早期(从30min开始)FNEDA、EDBmRNA表达的变化。结果正常人体皮肤无EDA、EDBmRNA表达;在损伤早期(≤3h)FNEDA、EDB的表达随时间的延长而呈现一种不断上升的趋势;EDA、EDBmRNA主要出现在表皮基底层细胞;EDA、EDBmRNA在标本离体后4h就不能检测到。结论FNEDA、EDB可作为早期损伤时间推断的较理想的参考指标,但原位杂交的检测方法不适用于实际应用。     

Evaluation of the correlation between time corpses spent in in-ground graves and findings at exhumation

To determine how long pathological findings persist after burial and which factors play a role in decomposition of a corpse, we evaluated all bodies exhumed under the auspices of the Institute of Legal Medicine at the Hannover Medical School between 1978 and 1997. A total of 87 exhumations (54 men, 33 women) were performed in this period. The time bodies remained buried varied between 5 days and 16.8 years (mean 1.5 years, median 2.3 months). Fifty-six percent of the bodies were exhumed after at most 3 months, 10% remained buried for greater than 3 years. Pathomorphological changes of the soft tissues and the internal organs remained evident after several months, in some cases after several years of burial. Overall, it was possible to evaluate internal organs after 5 years of burial. Bodies became mostly decomposed after approximately 8 years at the earliest, although it was still possible to evaluate some soft tissue remnants after 16.8 years. In stepwise logistic regression, both the length of time the body was buried (p < 0.00005) and the time of year (p < 0.0019) clearly affected the rate of physical change. The variables of sex (p = 0.33), age (p = 0.61) and changes in the integrity of the body before burial (trauma, autopsy before burial; p = 0.15) did not influence the physical state of the body after exhumation. Our data show that much information may be gained from an exhumation even after significant time has passed since burial.     

大鼠挫伤骨骼肌中M1/M2型巨噬细胞时间相关性研究

目的 研究大鼠骨骼肌挫伤后M1/M2型巨噬细胞浸润的动态变化规律结合组织学改变建立损伤时间推断方法.方法 建立大鼠骨骼肌挫伤模型,挫伤后6h、12h、24h、36h、48h、60h、72h、96h、144h、216h、336h为实验组,对照组不进行任何处理.采用HE染色法和免疫荧光多重染色方法观察骨骼肌挫伤后修复规律,...     

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。     

The occurrence of calcium salt deposition on dermal collagen fibres following electrical injury to porcine skin

Deposition of calcium salts on collagen fibres has been shown to occur in cathode areas from 2 days to 2 months after exposure to direct current (d.c.) via contact knobs measuring 12 mm in diameter using energy level from 0.5 to 96 J and on day 7 after exposure to alternating current (a.c.) via pointed electrodes using energy level from 30 to 50 J. In order to determine the statistical relation of this histological observation to the type of energy applied 1095 biopsies from 49 pigs including biopsies from skin areas exposed to heat, 50 Hz a.c., 100 kHz a.c. and d.c. as well as from unexposed skin were examined. The specificity was 1.0 using calcium deposition as the test criterium. The sensitivity for cathode areas was found to vary from 0.52 to 1.0 depending on the biopsy technique and the number of days after exposure. Calcium salts on collagen fibres seem uniformly to be present in the cathode area from day 4 to 7, the positive test answer being depending on the biopsy technique. For 50 Hz a.c. the sensitivity using a pointed electrode was found to vary from 0.08 to 0.27 dependent on the number of days after exposure. For all other types of energy the sensitivity was 0.