Time dependence of the expression of ICAM-1 (CD 54) in human skin wounds

Complement MASP-1 Modifies Endothelial Wound Healing

Endothelial wound-healing processes are fundamental for the maintenance and restoration of the circulatory system and are greatly affected by the factors present in the blood. We have previously shown that the complement protein mannan-binding lectin-associated serine protease-1 (MASP-1) induces the proinflammatory activation of endothelial cells and is able to cooperate with other proinflammatory activators. Our aim was to investigate the combined effect of mechanical wounding and MASP-1 on endothelial cells. Transcriptomic analysis showed that MASP-1 alters the expression of wound-healing-related and angiogenesis-related genes. Both wounding and MASP-1 induced Ca2+ mobilization when applied individually. However, MASP-1-induced Ca2+ mobilization was inhibited when the treatment was preceded by wounding. Mechanical wounding promoted CREB phosphorylation, and the presence of MASP-1 enhanced this effect. Wounding induced ICAM-1 and VCAM-1 expression on endothelial cells, and MASP-1 pretreatment further increased VCAM-1 levels. MASP-1 played a role in the subsequent stages of angiogenesis, facilitating the breakdown of the endothelial capillary network on Matrigel®. Our findings extend our general understanding of endothelial wound healing and highlight the importance of complement MASP-1 activation in wound-healing processes.

Vitality markers in forensic investigations: a literature review

Determining whether an injury was sustained in life or not is one of the most important topics in forensic medicine. Morphological, cytological, and biological techniques are used to assess wound vitality. Several markers involved in vital and supravital reactions increase the accuracy of wound age estimation. This systematic review aimed to investigate the main vitality markers used in forensic medicine to date. This review was conducted by performing a systematic literature search on online resources (PubMed Central database and Google Scholar) until May 2022. We identified 46 articles published between 1987 and May 2022, analyzing a total of 53 markers. Based on the data of this review, the most studied vitality markers were adhesion molecules (fibronectin, p-selectin, CD 15), pro-inflammatory cytokines (IL-6, IL-1β, TNF-α), cathepsin D, tryptase, and microRNAs (miRNAs). The most interesting studies were based on animal models: the different markers were investigated through immunohistochemical and qRT-PCR methods. The experimental methods were usually based on skin incisions, ligature marks, and burned skin areas. To date, it has not been possible to identify any gold standard markers based on the criteria of efficacy, specificity, and reliability; however, studies are still in progress. In the future, the use of miRNAs is promising as well as the combination of multiple markers. In this way, it will be possible to increase the sensitivity and specificity to validate systems or models for determining wound vitality in forensic practice.

Assessing wound vitality in decomposed bodies: a review of the literature

The capability of discriminating between a vital and a post-mortem injury has always been a central theme in forensic pathology, particularly when the corpse is an advanced state of decomposition. Post-mortem decay of the body can mask or disrupt the classical features of a skin lesion, making it difficult to establish the cause and manner of death. Taphonomically challenging situations pose several interpretative issues of skin lesions which need to be addressed with scientifically recent methods that are still limited in the forensic literature. For that reason, the present research aims at resuming what is currently available in the attempt to provide some insight regarding this topic. This review considers only original researches, in which the markers of vitality were studied a significant amount of time after death, in order to test post-mortem persistency of these markers over time. A number of 132 original articles and reviews were considered, and the most significant results are resumed in an overview table and in two intuitive figures. Though many researchers tried to establish the vitality of lesions in specimen, few analysed samples from bodies when a significant degree of putrefaction or burning had occurred. The most significant marker proved to be GPA, which sowed a satisfying persistence over time (up to 6 months in air putrefaction and 15 days in water). However, what clearly emerged is that further studies are needed to address the challenges of taphonomically transformed specimen and to possibly neutralize the variability of experimental conditions, which affect the reproducibility of results. In conclusion, this study could be a starting point for providing food for thoughts about the most useful markers to search for in unusually tricky autopsy cases.

State-of-the-Art on Wound Vitality Evaluation: A Systematic Review

The vitality demonstration refers to determining if an injury has been caused ante- or post-mortem, while wound age means to evaluate how long a subject has survived after the infliction of an injury. Histology alone is not enough to prove the vitality of a lesion. Recently, immunohistochemistry, biochemistry, and molecular biology have been introduced in the field of lesions vitality and age demonstration. The study was conducted according to the preferred reporting items for systematic review (PRISMA) protocol. The search terms were "wound", "lesion", "vitality", "evaluation", "immunohistochemistry", "proteins", "electrolytes", "mRNAs", and "miRNAs" in the title, abstract, and keywords. This evaluation left 137 scientific papers. This review aimed to collect all the knowledge on vital wound demonstration and provide a temporal distribution of the methods currently available, in order to determine the age of lesions, thus helping forensic pathologists in finding a way through the tangled jungle of wound vitality evaluation.

Bone Marrow-Derived Cells and Wound Age Estimation

Appropriate technology as well as specific target cells and molecules are key factors for determination of wound vitality or wound age in forensic practice. Wound examination is one of the most important tasks for forensic pathologists and is indispensable to distinguish antemortem wounds from postmortem damage. For vital wounds, estimating the age of the wound is also essential in determining how the wound is associated with the cause of death. We investigated bone marrow-derived cells as promising markers and their potential usefulness in forensic applications. Although examination of a single marker cannot provide high reliability and objectivity in estimating wound age, evaluating the appearance combination of bone marrow-derived cells and the other markers may allow for a more objective and accurate estimation of wound age.

Forensic Impact of the Omics Science Involved in the Wound: A Systematic Review

Background: In forensic autopsies, examining the wounds is one of the most critical aspects to clarify the causal relationship between the cause of death and the wounds observed on the corpse. However, on many occasions, it is difficult to differentiate antemortem injuries from post-mortem injuries, mainly when they occur very close to the moment of death. At present, various studies try to find biomarkers and clarify the molecular mechanisms involved in a wound due to the high variability of conditions in which they occur, thus being one of the most challenging problems in forensic pathology. This review aimed to study the omics data to determine the main lines of investigation emerging in the diagnosis of vital injuries, time of appearance, estimation of the age and vitality of the wound, and its possible contributions to the forensic field.

Methods: A systematic review of the human wound concerning forensic science was carried out by following PRISMA guidelines.

Results: This study sheds light on the role of omics research during the process of wounding, identifying different cytokines and other inflammatory mediators, as well as cells involved in the specific stage of the wound healing process, show great use in estimating the age of a wound. On the other hand, the expression levels of skin enzymes, proteins, metal ions, and other biomarkers play an essential role in differentiating vital and post-mortem wounds. More recent studies have begun to analyze and quantify mRNA from different genes that encode proteins that participate in the inflammation phase of a wound and miRNAs related to various cellular processes.

Conclusions: This study sheds light on the role of research in the molecular characterization of vital wounds, heralding a promising future for molecular characterization of wounds in the field of forensic pathology, opening up an important new area of research.

Systematic Review Registration: URL: https://www.crd.york.ac.uk/prospero/#myprospero, Identifier: CRD42021286623.

[Reliability of the immunohistochemical estimation of vitality and injury age: analysis and perspectives for study]

This review summarizes the literature data on the applicability of various immunohistochemical markers for the diagnosis of vitality and injury age. Current state of the problem of the reliability of the estimation of injury vitality, and the most promising immunohistochemical markers for further study are also considered.

Vital reactions - An updated overview

The question whether an injury was sustained during life or not is one of the most important subjects in forensic medicine. Therefore, vital reactions have been a main research topic in forensic medicine for a long period and many renowned forensic pathologists have devoted important papers to this field. The research area ranges from macroscopically visible organ reactions, over tissue alterations (enzyme histochemistry, later on immunohistochemistry with a wide range of enzymes and other analytes, molecular pathology) to biochemical responses to injury. Especially in the field of immunohistochemistry and molecular pathology much progress has been achieved in the last years (e.g. heat-shock-proteins or positive aquaporine3-staining in mechanical skin trauma). Furthermore, 20 years after its implementation postmortem imaging also contributes to the detection and visualization of vital signs. The aim of the present review is to provide an update on forensically relevant vital signs/vital reactions. Systemic vital reactions especially of the circulatory and respiratory system as well as local vital reactions will be addressed. Vital reactions of different organ systems will be discussed in detail regarding pathogenesis and possible postmortem evolution. Current research on immunohistochemically detectable vital reactions (heat-shock-protein expression, aquaporine3-staining in mechanical trauma of the skin) will be addressed as well as biochemical vital reactions (agonochemical stress reaction, myoglobine in electrocution death, hypoxanthine as marker of hypoxia).

Immunohistochemical analysis on aquaporin-1 and aquaporin-3 in skin wounds from the aspects of wound age determination

Immunohistochemical investigation of aquaporin (AQP)1 and AQP3 was performed in human skin wounds obtained from forensic autopsy cases. A total of 55 human skin wounds of different postinfliction intervals were collected as follows: group I, 0-3 days (n = 16); II, 4-7 days (n = 11); III, 9-14 days (n = 16); and IV, 17-21 days (n = 12). In uninjured skin samples, AQP1 and AQP3 could be slightly detected in dermal vessels and keratinocytes, respectively. The percentage of AQP1⁺ vessels and the number of AQP3⁺ keratinocytes were apparently elevated in accordance with wound ages. The number of AQP3⁺ keratinocytes was distinctly evident in groups II and III. Morphometrically, both AQP1⁺ vessel area and AQP3⁺ cell number were markedly increased in group II, compared with other three groups. With regard to forensic safety, AQP1⁺ vessel area of over 5% would imply wound ages of 4-12 days. Moreover, the positive area of > 15% would suggest wound age of 7-10 days. Especially, most samples of skin wounds aged 5-10 days except for only one sample (a 10-day-old wound) showed AQP3⁺ cell number of > 300, and the remaining other samples had that of < 300. Thus, the AQP3⁺ cell number of > 300 would indicate wound ages of 5-10 days. Collectively, immunohistochemical analyses of AQP1 and AQP3 in human skin wounds would support the objective accuracy of wound age determination.

[The myocardial histo-hematic barrier as a morphological criterion to be used for forensic medical diagnostics of alcoholic cardiomyopathy]

The author estimates the effectiveness of morphological diagnostics of alcoholic cardiomyopathy taking into consideration the general patterns of the structural and functional organization of the heart with special reference to myocardial histo-hematic barrier (HHB) the components of which are characterized by specific structural and functional properties and close relationships between them. It was shown that the morphological changes in the histo-hematic barrier reflect the range of variability of its morphological components and may be used as the indicators of its integrity and stability in the case of disorder. The study has demonstrated that the structural and functional degradation as well as decay of myocardial components may occur under the influence of both an ultrastrong acute impact and latent chronic intoxication or the diseases accompanied by rapid or slow persisting disintegration of the structural organization of the organ. The author maintains that the maximally high informative value of the assessment of the morphological criteria for alcoholic cardiomyopathy can be achieved with the use of special immunohistochemical methods allowing the concrete components of the biological structures to be identified and giving the exact location of the cellular and tissue components in the affected regions. Such an approach permits to detect the developing pathological changes at the molecular level with a high degree of accuracy and visualize the structural reorganization, if any, of each component of the myocardial histo-hematic barrier responsible for the lesions associated with alcoholic cardiomyopathy.

Could postmortem hemorrhage occur in the brain?: a preliminary study on the establishment and investigation of postmortem hypostatic hemorrhage using rabbit models

OBJECTIVE

The aim of this study was to explore whether postmortem hemorrhage can occur in brain tissue using rabbit models.

METHODS

The rabbits killed by air embolism were randomly divided into the horizontal-position group and the upside-down group. Autopsy was performed after 48 hours, and the brains were investigated with macroscopic assessment and histologic examination.

RESULTS

Macroscopically, congestion of vessels on the surface of the brain was identified in all the subjects in both groups. Microscopically, the presence of multifocal extravascular red blood cell aggregation was observed in brain parenchyma and subarachnoid space in the upside-down group. In contrast, no leakage of extravascular red blood cells was observed in the brain parenchyma and the subarachnoid space in the horizontal-position group.

CONCLUSIONS

Hypostatic and leakage bleeding can occur in sites of subarachnoid space and brain parenchyma of rabbits after death by nonforce with a certain period and certain position of the placement. This type of hemorrhage is challenging to differentiate from traumatic hemorrhage in pathologic practice. To avoid misdiagnosis, the clinical pathologists should keep in mind that the possibility of postmortem hypostatic hemorrhage needs to be ruled out when the diagnosis of subarachnoid hemorrhage or cerebral hemorrhage is established.

The role for decorin in delayed-type hypersensitivity

Decorin, a small leucine-rich proteoglycan, regulates extracellular matrix organization, growth factor-mediated signaling, and cell growth. Because decorin may directly modulate immune responses, we investigated its role in a mouse model of contact allergy (oxazolone-mediated delayed-type hypersensitivity [DTH]) in decorin-deficient (Dcn(-/-)) and wild-type mice. Dcn(-/-) mice showed a reduced ear swelling 24 h after oxazolone treatment with a concurrent attenuation of leukocyte infiltration. These findings were corroborated by reduced glucose metabolism, as determined by (18)fluordeoxyglucose uptake in positron emission tomography scans. Unexpectedly, polymorphonuclear leukocyte numbers in Dcn(-/-) blood vessels were significantly increased and accompanied by large numbers of flattened leukocytes adherent to the endothelium. Intravital microscopy and flow chamber and static adhesion assays confirmed increased adhesion and reduced transmigration of Dcn(-/-) leukocytes. Circulating blood neutrophil numbers were significantly increased in Dcn(-/-) mice 24 h after DTH elicitation, but they were only moderately increased in wild-type mice. Expression of the proinflammatory cytokine TNF-α was reduced, whereas syndecan-1 and ICAM-1 were overexpressed in inflamed ears of Dcn(-/-) mice, indicating that these adhesion molecules could be responsible for increased leukocyte adhesion. Decorin treatment of endothelial cells increased tyrosine phosphorylation and reduced syndecan-1 expression. Notably, absence of syndecan-1 in a genetic background lacking decorin rescued the attenuated DTH phenotype of Dcn(-/-) mice. Collectively, these results implicated a role for decorin in mediating DTH responses by influencing polymorphonuclear leukocyte attachment to the endothelium. This occurs via two nonmutually exclusive mechanisms that involve a direct antiadhesive effect on polymorphonuclear leukocytes and a negative regulation of ICAM-1 and syndecan-1 expression.

Time-dependent expression and distribution of monoacylglycerol lipase during the skin-incised wound healing in mice

The study investigated the expression of monoacylglycerol lipase (MGL) during the skin-incised wound healing in mice and applicability of the time-dependent expression of MGL to wound age determination by immunofluorescent staining, Western blotting, and real-time PCR. Furthermore, cell types were identified by double immunofluorescence. A total of 45 BALB/c male mice were used in this study. After a 1.5-cm-long incision in the central dorsum skin, mice were killed at intervals ranging from 6 h to 14 days, followed by the sampling of wound margin. In the control, there was a low-level expression of MGL in the epidermis, hair follicles, and glandulae sebaceae. In the injured skin, MGL immunoreactivity was mainly detected in the neutrophils, macrophages, and myofibroblasts. Morphometrically, the average ratios of MGL-positive cells were more than 50% at 5 and 7 days post-wounding, whereas it was <50% at the other posttraumatic intervals. By Western blotting analysis, the average ratio of MGL protein expression was highest at 5 days after injury, which had a ratio of >2.30. Similarly, the relative quantity of MGL mRNA expression maximized at posttraumatic 5 days in comparison with control as detected by real-time PCR, with an average ratio of >2.54. In conclusion, MGL expression is detected in neutrophils, macrophages, and myofibroblasts and significantly up-regulated, suggesting that it may play roles in response to inflammation during skin-incised wound healing. From the viewpoint of forensic pathology, MGL detection is applicable to skin wound age determination.

Hemorrhagic lividity of the neck: controlled induction of postmortem hypostatic hemorrhages

Postmortem hypostasis (livor mortis or lividity) is classically defined as the intravascular pooling of blood in gravitationally dependent parts of the body after death. However, intense lividity can be associated with small hemorrhages in the skin, so-called postmortem hypostatic hemorrhages (Tardieu spots). Postmortem hypostatic hemorrhages seem to contradict the usual understanding of lividity, since hemorrhage is by definition an extravascular phenomenon. Substantive medicolegal difficulties can arise if such hemorrhagic lividity develops in the necks of bodies that have ventral lividity due to prone position at the death scene. To study this phenomenon, we have developed a model for the controlled formation of hypostatic hemorrhages in human cadavers. In this model, extensive hypostatic hemorrhages or hemorrhagic lividity could be reproducibly but not universally induced in the soft tissues of the anterior neck and strap muscles. Histologic examination revealed hemorrhage that was microscopically indistinguishable from the acute hemorrhages observed in contusions. In addition, some larger areas of interstitially extravasated blood showed "buffy coat"-sedimentation separation of neutrophils that closely mimicked acute inflammation, further confounding the correct diagnosis. This research implies that hypostatic hemorrhages form after the progressive development of increasing gravitational hydrostatic pressure in an autolysing venous plexus. Thus, this phenomenon can mimic soft tissue injury ("pseudo-bruising") and the internal injuries related to strangulation. Caution must be exercised when diagnosing strangulation in bodies with anterior neck lividity.

Timing of skin wounds

Wound examination is indispensable in forensic practice. It is always necessary to determine wound vitality or wound age to correctly evaluate the relationship between death and any wounds. Thus, the determination of wound vitality or wound age is a classic but still modern theme in forensic pathology. Skin wound healing is a primitive but well orchestrated biological phenomena consisting of three sequential phases, inflammation, proliferation, and maturation. Many biological substances are involved in the process of wound repair, and this short and simplified overview of wound healing can be adopted to determine wound vitality or wound age in forensic medicine. With the development of immunohistochemistry and chemical analyses, the scientific field of wound age determination has advanced progressively during recent years. In particular, it has been demonstrated that collagens, cytokines, and growth factors are useful candidates and markers for the determination of wound vitality or age. In this review article, some interesting and instructive results are presented, contributing to the future practice of every forensic pathologist.

Time-course changes in the expression of heme oxygenase-1 in human subcutaneous hemorrhage

To determine the time-course of human subcutaneous hemorrhage, heme oxygenase (HO)-1 expression and macrophage infiltration were observed using an immunohistochemical technique and semiquantitative analysis. The number of immunoreactive cells and the number of all infiltrating cells of each microscopic field were counted, and the ratio of the former to the latter was calculated as the positive cells ratio. An increase in the HO-1-positive cells ratio was observed starting at 3 h after injury, and the maximum ratio was observed 3 days after injury. The pattern of the increase in the macrophage ratio was similar to that of the HO-1-positive cells ratio in the early period after injury. Observation of serial sections revealed that the expression of HO-1 in the cells corresponded to the localization of macrophage. The present results suggest that the determination of HO-1 expression, as derived from macrophages, might be useful for the estimation of the time-course of subcutaneous hemorrhage.

Vitality and time course of wounds

The term "wound" describes the morphologic-functional disruption of the continuity of a tissue structure. A wound can be inflicted during life--when the cardiovascular and respiratory system is still intact--or after death, i.e. after cardiac and respiratory arrest. Traumatization during life triggers vital reactions that do not occur in postmortem wounds. Three types of vital reactions in wound healing can be distinguished: Reactions of the scavenger type, which are almost exclusively mediated by blood cells. Reactions by complex signal transduction pathways, which involves cascade-like release of chemokines, cytokines and adhesion molecules and may influence type 1 and type 3 reactions. Reactions of the scarring type, which involve the final repair of the damaged tissue and are carried out primarily by cells residing at the wound edges, i.e. partly concerning mesenchymal cells and partly tissue-specific cells dependent on the involved organ system. The three different types of reaction follow roughly parallel temporal courses that include cascade-like interactions among themselves. Whereas demonstration of a vital reaction suffices to differentiate an intravital wound from a postmortem wound, the vital reactions themselves follow strictly temporal courses. The regular time-dependent occurrence of each phenomenon allows--in limits--a reliable temporal classification of wound healing. A review will be given especially demonstrating the actual German scientific research in vitality and in skin wound timing as well as in timing of mechanical injury of the brain.

Forensic application of VEGF expression to skin wound age determination

An immunohistochemical study combined with morphometry was carried out to examine the time-dependent expression of vascular endothelial growth factor (VEGF) using 53 human skin wounds with different wound ages (groups I: 0-12 h, II: 1-4 days, III: 7-14 days and IV: 17-21 days). In the human wound specimens aged 4-12 h, neutrophils recruited at the wound showed no positive signals for VEGF. With an increase in wound ages of > or =7 days, granulation tissue and angiogenesis were observed, with the migration of macrophages and fibroblasts of which the cytoplasm expressed VEGF-positive reactions. Morphometrically, the average VEGF-positive ratio was highest in group III, followed by that of group IV. In groups III and IV, 13 out of 26 wound samples had VEGF-positive ratios of more than 50%. However, all of the wound samples in groups I and II showed VEGF-positive ratios of less than 50%. With regard to the practical applicability and forensic validity, these observations suggest that a VEGF-positive ratio of more than 50% possibly indicates a wound age of 7 days or more.

The time-dependent expression of fibronectin, MRP8, MRP14 and defensin in surgically treated human skin wounds

Fibronectin, MRP8, MRP14 and defensin were detected immunohistochemically in 46 surgically treated, fresh (hours old) human wounds and in wounds of 13 individuals who died immediately from fatal trauma (airplane crashes or train rollovers). In immediate fatal trauma, it was not possible to detect fibronectin outside of bleeding areas nor could inflammatory cells be visualized in the interstitium using MRP8, MRP14, or defensin antibodies. Fibronectin staining could be regularly demonstrated in wounds at least 20 min-old. Granulocytic infiltrates limited to the perivasal space could be detected 20-30 min after infliction of the wound expressing MRP8, MRP14 and defensin. It was also possible to detect fibronectin networks and MRP8-, MRP14-, and defensin-positive granulocytes and macrophages in particular wounds up to 30 days-old. No differences between the expression of MRP8 and MRP14 could be demonstrated in the wounds, the majority of which were only several hours old. As wound age increased, the number of defensin-positive granulocytes detected decreased. The immunohistochemical detection of fibronectin is a useful way to demonstrate vitality in fresh wounds, beginning about 20-30 min post-trauma. However, detection of MRP8, MRP14 and defensin provides no advantage over the routine histological detection of granulocytes and macrophages in wounds under 1-2 days old.

Immunohistochemical detection of chemokines in human skin wounds and its application to wound age determination

Immunohistochemical studies on the time-dependent expression of the chemokines such as interleukin (IL)-8, monocyte chemoattractant protein (MCP)-1 and macrophage inflammatory protein (MIP)-1alpha were performed on 50 human skin wounds with different wound ages (group I 0-12 h, group II 1-4 days, group III 7-14 days and group IV 17-21 days). In the wound specimens with wound ages between 4 and 12 h, neutrophils mainly showed positive reactions for IL-8, MCP-1 and MIP-1alpha. With increasing wound ages, macrophages and fibroblasts were positively stained with anti-IL-8, MIP-1alpha and MCP-1 antibodies. Morphometrically, there was a similar distribution in the positive ratios of the inflammatory cells among IL-8, MCP-1 and MIP-alpha. The positive ratios of each chemokine were very low in group I and a considerable increase of the positive ratios in each chemokine was observed in group II (mean +/- standard error IL-8: 59.8 +/- 2.1%, MCP-1: 42.4 +/- 3.1% and MIP-1alpha: 50.4 +/- 3.7%). Although the positive ratios for each chemokine gradually decreased according to the wound age, the mean positive ratios in groups III and IV were significantly higher than those in group I. From the forensic aspect, these chemokines are considered useful markers for wound age determination. Thus, ratios of > 50% for IL-8, > 30% for MCP-1 or > 40% for MIP-1alpha indicate a wound age of at least I day. Moreover, the combined investigation of these three chemokines can make wound age determination more objective and accurate.

Forensic wound examination

Wound examination is of prime importance in forensic pathology, and it is desirable to establish a wound examination system in order to evaluate and record the nature of wound more accurately and objectively. Modern diagnostic techniques and devices as well as advanced cell-biological methods should be introduced as the means for this aim. For example, radiological, endoscopic or magnetic resonance imaging (MRI) examination have been used in addition to examination with the naked eye. In our department, a binocular surgical operating microscope is routinely employed at forensic autopsy, which is useful for elucidating the nature of wound in more detail. It is also necessary to determine whether a wound has vitality, and, if antemortem, how long before death the wound has been sustained. For the determination of wound age including vitality, various biological factors such as cytokines and extracellular matrix components involved in wound healing have been examined by histopathological methods. Our studies have shown that interleukin (IL)-1alpha, IL-1 b, IL-6, IL-10 and tumor necrosis factor-alpha are possibly useful markers for wound age determination as well as cell-biological indicators of vitality. Furthermore, molecular biological techniques have been intended to be applied to wound examination; our experimental study has shown that even mRNA of cytokines mentioned above can be histologically detected by reverse transcriptase-polymerase chain reaction or in situ hybridization. A trial of forensic wound examination from macroscopic to molecular level is discussed.

Immunohistochemical study on the expression of c-Fos and c-Jun in human skin wounds

An immunohistochemical study on the temporal expression of c-Fos and c-Jun, both of which designate proto-oncogene products, was performed on 60 human skin wounds with different post-infliction intervals. In unwounded skin, c-Fos or c-Jun was immunolocalized at the nuclei of the epidermal cells in the basal layer, hair follicle cells and sweat gland cells. During the early inflammatory phase of wound healing, the nuclei of polymorphonuclear cells (probably neutrophils), mainly infiltrating at the wound site, were labeled with anti-c-Fos or -c-Jun antibody. As the wound age increased, the neutrophils had disappeared at the wound site, and both mononuclear cells (probably macrophages) and spindle-shaped fibroblastic cells, which expressed a c-Fos or c-Jun positive reaction in the nuclei, were mainly observed. Morphometrically, the distribution of the c-Fos-positive ratio was very similar to that of the c-Jun-positive ratio; the positive ratio was considerably increased in wound specimens with a post-infliction interval of > or = 1 day, thus indicating the late inflammatory or proliferative phase. This study showed that c-Fos and c-Jun were closely involved in the inflammatory phase as well as the proliferative phase of the wound healing process.