Постмортално одредување на староста на крвните подливи

Abstract

Introduction: Bruises are common injuries found in people who die from violent death and are particularly important in forensic medicine. In practice there are cases where it is of particular interest to determine with certainty the age of bruises. Knowing and analyzing the biological processes associated with the healing of bruises could provide more reliable information on their age. Objectives: The main purpose of this study was to determine the characteristics of different age-matched bruises. Because many factors influence the occurrence and presentation of bruise, each method used to interpret their age has its advantages and limitations. Further aims of the study will highlight the advantages and limitations of these methods in daily forensic practice, as well as the conceptualization of a general scheme for determining the age of bruises, by combining several methods. Material and methods: The assessed material comprises 120 tissue sections, 60 of which are normal human skin specimens as a control group and 60 bruised skin sections as an experimental group, with 4 subgroups, obtained during routine autopsies at the Institute for forensic medicine and deontology, at the Faculty of Medicine in Skopje. Along with the material, autopsy protocols are also analyzed for interpretation of results, in addition to histological analysis. Within the study group, subgroups of bruises with different time of injury were predicted. All samples were analyzed using a visual observation method, which assesses the color, location and size of the bruises. Subsequently, histological analysis of the tissue followed, with the hematoxylin and eosin staining method, as the initial histological analysis to confirm the bleeding, as well as additional staining with the Perl`s Prossian Blue method, Giemsa method, Masson Goldner, Alcian blue SCHIFF and Elastica van Gieson method, to prove presense of macrophages in the area of bleeding, as well as the localisation of the bruises in the skin. Immunohistochemically, with the use of an anti heme-oxigenase-1 [anti HO-1] antibody, presence of heme oxygenase enzyme in macrophages in the bleeding area was demonstrated. Results: Visual observation method confirmed the color change from the initial presentation of red to purple, blue, green and finally yellow in old bruises, over a period of time. Histological analysis confirmed presence of inflammatory cells, neutrophil granulocytes (neutrophils) and macrophages in the area of bleeding, as well as presence of hemosiderin, a pigment that is a product of hemoglobin metabolism, in the macrophages themselves. Immunohistochemical analysis confirmed the presence and activity of the heme oxygenase 1 enzyme [HO-1] in macrophages, a finding that suggests a reparative process in the area of bleeding. In group A, infiltration with neutrophils was observed in the area of bleeding, along with extravasated red blood cells. This finding is characteristic for fresh bruises, not older than 24 hours. In the next experimental group, Б, in bruises aged 1 to 3 days, in the area of bleedeng was observed initial minimal infiltration with macrophages. Their numerical representation (density) progressed in the following experimental groups, В and Г, ie in bruises aged 3 to 7 and 7 to 14 days. The obtained results were statistically processed and showed significant values in the compared groups, evaluated by Student`s t test (paired groups). Results showed that density of neutrophils in group A compared to density of neutrophils in group B, proved to be statistically significant with p<0,0001. Evaluation of density of macrophages in group A and Б showed statistically signification in favor of group B, with p<0,0001. The same statistically findings were evaluated for group Б and В, and В and Г, when these groups were tested with paired groups Student`S t test, with statistically significans of p< 0,0001. These findings suggest that density of macrophages rise in older bruises, ie in in bruises aged 3 to 7 and 7 to 14 days. The use of several complementary methods has given us the opportunity to design a simple algorithm in interpreting the age of bruises. Conclusion: In the biological process of repairing in bruises, different cells of the immune system are active in different time instance. Neutrophil granulocytes are activated as soon as the bruise occur. They are replaced with macrophages within a few hours, which, after a few days, begin to actively metabolize the iron from the bleeding area, producing enzyme HO-1.