Ultrastructural changes in dermal pig skin after exposure to heat and electric energy and acid and basic solutions

In order to describe the ultrastructure of the histopathological changes in dermis after exposure to electrical energy, heat energy and acid and basic solutions the skin of fully anaesthetized Danish Landrace pigs were exposed to direct current, heat (80 degrees C and 450 degrees C) and acid and basic solutions. Biopsies were obtained immediately after the exposure from all types of injury. Biopsies from the cathode areas biopsies were also taken on day 1 and day 2.5 in order to describe the initial calcium deposits. Homogeneous collagen fibres without any birefringence from heat exposed areas were ultrastructurally composed of filamentous materials. Collagen fibres with fine densely spaced cross-striation from cathode areas and areas exposed to basic solutions were shown ultrastructurally to consist of parallelly arranged collagen fibrils with regular waves. It is concluded that the cross-striation of the collagen fibres observed in polarized light are due to a periodic change in the orientation of the fibres seen as waves of the fibres. The ultrastructure of dermal cells were similar to that of epidermal cells following the different types of influence. Characteristically the nuclei were condensed following heat and more electron-lucent following direct current (d.c.) and acid and basic solutions. In cathode areas and areas influenced by basic solutions the electron-lucent nuclei contained fine fibrils. The ultrastructural study supports the suggestion from light microscopic studies that the morphology of anode and cathode lesions shows resemblance to acid induced and basic induced lesions, respectively. Apatite crystals were observed on day 2.5 at the periphery of the collagen fibrils and in the matrix of elastic fibres.     

The morphogenesis of electrically and heat-induced dermal changes in pig skin

In order to establish pathological evidence in dermis for distinguishing between sequelae of electrical torture and those of other superficial injuries, the skin of eleven fully anaesthetized Danish Landrace pigs have been exposed to heat and electrical energy from either 50 Hz alternating current (a.c.) or direct current (d.c.) via 12 mm large contact knobs or via a pointed 0.5 mm large electrode (only 50 Hz a.c.). The lesions have been examined from 1 to 126 days after the injury. While heat lesions exposed to energy lower than 60 joule only gave minor changes, heat lesions exposed to more than 60 joule showed changes in both collagen fibres (basophilic or eosinophilic fibres without any birefringence or coarse cross-striation in polarized light, respectively) and dermal cells (granular cytoplasm). Areas exposed to 50 Hz a.c. via 0.5 mm. electrode showed basophilic collagen fibres and in a few biopsies on day 7 calcium salts on collagen fibres. Using 12 mm large electrodes the changes were minor, but basophilic and eosinophilic collagen fibres with no birefringence or with fine/coarse cross-striation respectively were seen. Even cells with 'vesicular nuclei' were seen on day 1 and 2 after the injury. The changes in the anode area showed resemblance to that of heat lesions (basophilic collagen fibres). Eosinophilic collagen fibres with fine densely spaced cross-striation in polarized light and 'vesicular nuclei' as well as collagen fibres with calcium salts were seen in the cathode lesions. It is concluded that the dermal changes in the cathode area are specific for electrical injury from day 1 to 14. However, earlier studies have demonstrated dermal changes specific for electrical injury at day 0 and the presence of calcified collagen fibres up to 2 months after injury. The dermal changes in anode lesions were non specific and could not be differentiated from those found in heat lesions. Alternating current lesions (50 Hz) were specific from day 1 to day 7, when the pointed electrode was used, but only in a few days when the energy was transferred via the 12-mm electrodes.     

Early epidermal changes in heat- and electrically injured pig skin. I. A light microscopic study

In order to find methods applicable for disclosing electrical torture, pig skin was exposed to heat and electricity under controlled circumstances. Biopsies were obtained immediately after exposure and the morphology of the heat lesions was compared to that of electrical lesions. The cytoplasm of epidermal cells in heat lesions appeared granular or fibrillar, while the nuclei were rather unaffected. In electrical lesions the cytoplasm appeared homogeneous often with a peculiar white colour in hematoxylin-eosin stained sections. The nuclei were either dark and shadowy or enlarged and vesicular. The keratin in electrical lesions often showed a bright yellow colour. Small defects in the epidermis were seen in some electrical lesions. Thus the morphology of electrical lesions differed markedly from that of heat lesions. Although some of these differences may be due to differences in distribution and intensity of energy, it is probable that pH shifts in the cells due to electrolysis is the main cause of the specific morphology of electrical lesions.     

Electrically-induced collagen calcification in pig skin. A histopathologic and histochemical study

Deposition of calcium salts on collagen fibres in skin of fully anaesthetized pigs was induced by exposure to direct current (d.c.). In biopsies obtained from cathode areas successively from day 1 to day 7 after exposure the histopathologic and histochemical changes before and after the initial deposition of calcium salts have been examined. For comparison skin sites with intradermal injected calcium hydroxyapatite crystals were studied in addition. Small areas of calcified collagen and elastic fibres were noted in viable tissue 2 days after d.c. exposure. In succeeding days the calcified areas enlarged with new deposits always more superficial and closer to the epidermis than the original calcium deposits. Preconditions for calcification appear to be (1) a pH change in basic direction and/or the electrochemical processes specific to the cathode area and (2) a viable tissue. Elastic fibres appear to have a lower calcification threshold than collagen fibres. A positive staining for glycoproteins (PAS) and glycosaminoglycans (alcian blue pH 2.5) was noted in the calcified collagen fibres simultaneously with the calcification. In succeeding days the intensity of the staining reactions increased. Whether changes in the glycoproteins, collagen and its intimately bound glycosaminoglycans precede the calcification or the staining reactions develop secondarily to this deposition is not known. However, seven days after intradermal injections of Ca-apatite crystals in pig skin small and large crystals were observed ultrastructurally without any relation to collagen fibrils, but the calcified tissue presented a positive PAS and alcian blue reaction from day 2. Thus the PAS and alcian blue stainings in this model develop secondary to the deposition of calcium salts.     

Early epidermal changes in heat- and electrically injured pig skin. II. An electron microscopic study

In order to find methods applicable for disclosing electrical torture, pig skin was exposed to heat and electricity under controlled circumstances. Biopsies for electron microscopy were obtained immediately after exposure. In heat lesions the nuclei were slightly distorted, sometimes with broken nuclear membranes. The tonofilaments were clumped, intracellular oedema was present and cell membranes were ruptured between desmosomes. In electrical lesions the nuclei were usually enlarged with strongly condensed chromatin. Some nuclei were composed of fine, evenly dispersed granular material. The cytoplasm appeared homogeneous, in large magnification finely granular. Cell borders could sometimes be identified located in situ. In the stratum corneum, which appeared normal in heat lesions, single or several cells or large areas had an electron-dense appearance. The difference in ultrastructure of heat and electrical lesions makes it probable that electricity has a specific action on epidermal cells.     

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.     

Dermal absorption of kerosene components in rats and the influence of its amount and area of exposure

The influences of amount and area of dermal exposure to kerosene upon the levels of kerosene components in biological samples were examined in vivo and in vitro. Thirty-two rats were randomly divided into four groups and exposed to kerosene through the abdominal skin for 2h. The amounts (soaked in cotton) and area of kerosene exposed were 1 ml/4 cm(2) in Group I, 4 ml/4 cm(2) in Group II, 4 ml/16 cm(2) in Group III and 16 ml/64 cm(2) in Group IV. Before, then 5, 10, 20, 30, 45, 60, 90 and 120 min after exposure, 0.5 ml of blood was collected. Solid tissue samples, including the exposed skin area, were harvested at 120 min. Kerosene components were analyzed by gas chromatography/mass spectrometry. Trimethylbenzens (TMBs) that are easily absorbed kerosene components, appeared at 5-20 min. The time course changes in TMB levels in blood were significantly different between Groups I and II or Groups I and III, and almost identical between Groups II and III. Similar trends were observed in tissue samples at 120 min. High concentrations of aliphatic hydrocarbons (AHCs) were detected in the exposed skin and the AHC levels were dependent on the amount of kerosene exposed per unit area. These results suggest that (1) dermal absorption of kerosene occurs soon after dermal exposure started, (2) absorption of TMBs is influenced by the total amount of kerosene rather than area of exposure, and (3) AHCs remaining in the skin at significant levels are influenced by the amount of kerosene per unit area exposed.     

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.     

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.     

The persistence of fibres on skin in an outdoor deposition crime scene scenario

Textile fibres were transferred to a pig skin carcass and their persistence determined at daily intervals for up to a 12 day period during which time the carcass was left outdoors exposed to the prevailing weather conditions and animal activity. In the absence of strong winds and precipitation, the loss of fibres was found to be exponential. Stronger winds and heavier precipitation caused an increase in the rate of loss of fibres. The results of this study showed that the majority of fibres transferred to a body deposited outdoors, can be expected to be lost after the first 2 days, however, none of the experiments performed resulted in a complete loss of fibres, even after 12 days exposure. These persistence characteristics differed from those observed in a similar study using small sections of skin, rather than carcasses.The implications of the results of the present study in relation to the examination of fibre evidence in cases of homicide are discussed.     

Changes in the ratio of collagen type I and III in the interlobular interstitium of the lung in sudden infant death--a pilot study

In a blind study the interlobular interstitial connective tissue in paraffin embedded lung sections from 45 autopsy cases aged under 2 years (23 SIDS and 22 Non-SIDS) were investigated with the aim of determining the collagen type I:type III ratio by means of polarimetric evaluation. Sections were stained with Resorcin-Fuchsin for elastin fibres, Celestine Blue/Mayer's Haematoxylin for nuclear details and with Solophenyl Red 3 BL in saturated picric acid solution for the differential staining of type I and type III collagen fibres for polarization microscopy. The type I fibres were orange and the type III fibres green in colour. The spectral distribution of the coloured polarized light from the sections was determined and peaks were evident at the wavelengths 590 nm for the orange coloured light of type I and 490 nm for the green coloured light of type III collagen. With corresponding filtres the intensities of the orange and green emissions were separately measured at several points adjacent to lymphatic vessels. The ratio collagen I/III, deduced from the ratio of the intensities of orange to green light, was significantly higher in the SIDS-group than in the Non-SIDS-group (a = 0.001) due to the increase in the amount of collagen type I and could indicate an insiduous fibrosis resulting from lymphostasis.     

Dermal lesions after post mortem petrol-exposure

The effect of post mortem contact of the skin with petrol was investigated in 18 corpses with exposure times between 10 min and 24 h. The earliest onset of skin changes was observed within 2 h of exposure. They consisted of swelling and wrinkling with detachment of the upper layers of the skin (positive Nikolski's sign). Histologically the lesions appeared as non-vital acantholyses located in the prickle-cell layer with formation of intra-epidermal bullae. An influence of age and sex could be excluded, the earlier onset of lesions at 22 degrees C than at 4 degrees C was not statistically significant. These findings prove that post mortem petrol exposure may lead to dermal lesions.     

Skin changes following defibrillation. The effect of high voltage direct current

Previously, electrical injuries have been suggested caused only by the concomitant heat developed during the passage of an electrical current. Recent experimental studies on fully anesthetized pigs and the study of one human case have, however, shown typical electrical alterations. The purpose of the present study was further to evaluate the histology of electrically induced changes in the skin in humans. In addition, supplementary in vivo methods for evaluation of skin changes as high-frequency ultrasound and Raman spectroscopy were used. The skin of 11 patients treated with a defibrillation of the heart was examined for macroscopic changes, the skin of eight of them also for histologic changes and for changes observable via supplementary methods. Immediately and 7 days after the defibrillation, fractions of a narrow red ring were observed along the periphery of the tin-foil electrode. Epidermis showed signs previously observed following electrical influence: segmental alterations often related to the openings of sweat ducts, darkstaining or "empty" nuclei and homogeneous cytoplasm, eosinophilic or pale. Dermis did not show the specific sign of electrical influence: deposits of calcium salts on dermal fibres, neither via histologic examination nor via high-frequency ultrasonography and Raman spectroscopy. Fractions of a narrow red ring along the periphery of the electrode showing histological signs of electric influence in epidermis thus appear to be characteristic of high voltage electrical injury.     

Bullet or bite--a contribution to the morphogenesis of gunshot dermal injury

Histopathologic studies of dermal dog bites revealed changes identical with those observed in distant gunshot skin entrance wounds and in a presternal skin stab wound made by a screwdriver. The similarity of the epithelial and collagen changes produced by these three totally different traumatizing, perforating agencies indicate that it is the bullet's penetrating and crushing power, and not its caloric content, that is responsible for the characteristic dermal collagen changes noted in these common injuries.     

Dermal surface in electric and thermal injuries. Observations by scanning electron microscopy

The dermal surface (after enzymatic digestion of the dermo-epidermal junction) in electric and heat lesions is described. There do not appear to be elements that help in forming a precise differential diagnosis. It is possible, however, to differentiate these lesions from all traumatic cutaneous injuries and some limited nontraumatic lesions (e.g., verrucae). Remarkably good preservation of the dermal surface even in an advanced state of decomposition does suggest the possibility of certain diagnosis of electric and heat lesions even when postmortem phenomena have greatly damaged or even totally removed the epithelial part of the skin.     

New observations on cutaneous firearm wounds

The authors describe the aspect of the dermal surface in firearm wounds. In entrance wounds, the abraded area is rather evident, with loss of the papillary pattern and lacerations of the basement membrane. Exit wounds appear as irregularly lacerated interruptions, with protruding collagen fibers; the surrounding dermis has nearly undamaged papillae. Also described, still on the dermal surface, are the flame effect and the powder tattooing. Evident lesions of the basement membrane, produced by the grains of powder, can be observed. Particles [gunshot residues (GSR)] are often recognizable lying on the dermal surface or entrapped among the collagen fibers of the superficial dermis.     

Homicide by asphyxia--yes or no? On the use of muscle histology

In two cases of death autopsy revealed large hemorrhages in the muscles of the neck, which lead to the conclusion of a murder by strangulation, e.g. with a soft tool. Histologic examination of the injured muscles didn't show any sign of vital reaction, which means, that they had developed post mortem. There was no reason for further suspicion of a violent crime. Later it became obvious, that neck lesions resulted from inadequate recovery and transport of the corpses. "Vital" type of muscular alteration is characterized by segmental or disk-like fragmentation of muscle fibres, loss of sarcoplasmatic cross-striation and appearance of pathologic longitudinal fibrillar structures. These signs are missing in case of a postmortal injury, whereas the cross striation is intact. The slides should be stained with PTAH. With these two cases we would like to demonstrate the importance of histologic examination of injured muscles, when question for intravital or postmortal injury rises.     

Pathological demonstration of rapid involvement into the subcutaneous tissue in a case of fatal hydrofluoric acid burns

We report an autopsy case of a man who suffered accidental chemical burns following exposure to 60% hydrofluoric acid. The extent of the burns covered about 30% of his body surface, and cardiopulmonary arrest occurred about 30min after the exposure. At autopsy, the skin of the affected area showed greenish gray or black coloring with thin circumferential erythema, and this discoloration extended as far as the periosteum of the skull. However, such discoloration was not found on the mucosa of the airway or the gastrointestinal tract. Microscopically, severe liquefactive necrosis was already evident on the skin. Elastic fibers within the dermis were completely lost, and the entire wall of large vessels within the subcutaneous layer was already severely affected. Blood analysis in the emergency room showed hypocalcemia, and the levels of fluoride ions in the postmortem blood and urine showed extremely high values. However, fewer fluoride ions were detected from the lung tissue. The present case suggests that the hydrofluoric acid had immediately penetrated down into the deep layer of the skin, thereby involving the large vessels present within the subcutaneous layer. These pathological findings of the skin seen in the present case explain the mechanism behind the rapid dissemination of fluoride ions which entered the bloodstream from damaged arteries, resulting in the development of acute toxicity.     

Dichroism measurements in forensic fibre examination. Part 2 — Dyed polyamide, wool and silk fibres

A number of dyed polyamide, wool and silk samples were examined with plane polarized light on their dichroic behavior by optical light microscopy (OLM) and microspectrophotometry with plane polarized light (MSP-PPL). It was found that most of these acid dyed peptidic fibres possess dichroism, but these are weaker than the effects previously described for polyester fibres. The small effects may be not observed, especially for wool, but these can be measured using MSP-PPL.In the three peptidic fibre classes, for the first time, a so called “inverse dichroism” is observed which appears in the absorption spectra as a hyperchromic effect.     

Frozen cadaver. Antemortem versus postmortem.

Three categories of skin from Hanford miniature swine were examined microscopically: normal, unfrozen skin; skin exposed to -75 degrees C air for 5 min, 6 h postinjury; and skin frozen postmortem. Frostbitten skin (antemortem freezing) was characterized grossly by a purple discoloration and microscopically by dilated, blood-filled, superficial capillaries. Other changes in the frostbitten skin were vacuolated epithelial cells and dermal edema. Unfrozen skin (controls) and skin frozen postmortem were more difficult to differentiate. However, the epidermis of the latter usually was compressed and more basophilic. We concluded that skin frozen antemortem could be separated from skin frozen postmortem by its intense hyperemia, characterized grossly as a purple discoloration and microscopically by engorged capillaries.