الفهرس 
PathophysiologyOnly 14 pages are availabe for public view
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Abstract
One of the biggest challenges faced by forensic pathologists is death due to electrocution. In many cases, one can see the gross pathological findings such as Joule burns, but in other cases – almost half of all cases – no gross pathological findings can be seen. When electrocution occurs without detectable body marks as in cases of electrocution in standing water or electrocution in concealed areas of the body, it poses a dilemma about in which body location to look for microscopic evidence of current injury. Several morphological changes of the skin and the internal organs are used for the diagnosis of electrical injury. In deaths from electrocution the presence of skin lesions and pathological examinations of tissue samples obtained during the autopsy usually help to determine the cause of death. The aim of this work was to evaluate the manifestations and postmortem findings that were observed on albino rats during and immediately after low voltage electrocution, and to evaluate electrolytes and complete blood count changes. Also to show histopathological, histochemical& immune-histochemical electrically induced changes in the heart, brain, skin &skeletal muscle at both contact sites. Finally to detect the copper traces of conductor used at sites of contact and to evaluate the cause of death of low voltage electrocution in different pathways in attempt to settle the diagnosis of electrocution as approximate cause of death.The study was carried on 170 adult male albino rats of Sprague species 150-200 grams. The animals were divided into three main groups, control group and two experimental groups (group II and III). GroupI: Control groups consisted of 10 rats. Sacrificed by cervical dislocation without any application of electrical current. GroupII: This group of 80 rats was electrocuted by alternating current 110 volt and was divided into five equal subgroups according to different current pathways. Subgroup IIa :( 16 rats) The points of electrical contact were on the skin of left forelimb (entry) and the skin of right hind limb (exit).The rats were electrocuted till death. Subgroup IIb :( 16 rats) The points of electrical contact were on the skin of right forelimb (entry) and the skin of left hind limb (exit).The rats were electrocuted till death. Subgroup IIc :( 16 rats) The points of electrical contact were on the skin of right forelimb (entry) and the skin of left forelimb (exit).The rats were electrocuted till death. Subgroup IId :( 16 rats) The points of electrical contact were on the skin of right hind limb (entry) and the skin of left hind limb (exit). The rats were electrocuted for seven minutes and no death occurred so we scarified the animals by cervical dislocation.Subgroup IIe :( 16 rats) The points of electrical contact were on the skin of head (entry) and the skin of the tail (exit).The rats were electrocuted till death. GroupIII: This group of 80 rats was electrocuted by alternating current 220 volt and was divided into five equal subgroups according to different current pathways as in group (II). Blood samples were taken from all the control and the experimental groups for CBC and electrolyte analysis. Tissue samples from all the control and the experimental groups were taken from skin at both site of contact (inlet and exit), and were divided into two halves, one for histopathological, histochemical and immune-histochemical studies and the other for detection of copper traces by atomic absorption spectrometry. Also tissue samples from all the control and the experimental groups were taken from skeletal muscles at both site of contact (inlet and exit) brain and heart, for histopathological, histochemical and immune-histochemical studies. The main findings of the present study were as follow: 1- As regard manifestations and gross post mortem finding that were observed in albino rats during and immediately after low voltage electrocution (alternating current 110 and 220 volt): Local electrical burn at both contact sites (entry and exit) and tetanic contractions were observed in all rats of both electrocuted groups (II &III).While respiratory and CNS manifestations were observed in relatively small percentages of all subgroups except (IId&IIId) which did not show any finding except for local burn and tetanic contractions. Regarding external gross postmortem findings: The skin in most rats did not show any specific features except for paleness while the remaining rats in each subgroup were cyanosed with bluish coloration. Internal examination showed markedly congested organs with petechiae which were verified in (IIa: 18.75%), (IIb: 25%), (IIc: 18.75%) and (IIe: 37.5%), (IIIa: 25%), (IIIb: 25%), (IIIc: 18.5%), and (IIIe: 43.75%) while the remaining rats showed pale or slightly congested organs. 2-As regard the hematological parameters (Complete Blood Count ”CBC”): The difference in the mean values of WBCs, RBCs &Platelets counts and hemoglobin level in 110 electrocuted group (II) in comparison with control group (I) or in 220 electrocuted group (III) when compared also with the control group (I) was statistically non significant. The same findings were shown on comparing 110 electrocuted group (II) with 220 electrocuted group (III). Comparing the subgroups of group (II) with each other and also group (III) subgroups with each other showed no significant difference. 3-As regard the biochemical parameters (sodium and potassium electrolytes): There was statistically highly significant increment in the mean value of potassium level in venous blood of adult male albino rats in both 110 electrocuted group (II) and 220 electrocuted group (III) in comparison with control group (I), while comparing sodium levels revealed non significant difference. Subgroups (IId) as well as (IIId) subgroup showed statistically significant increase as regard potassium level in comparison with other subgroups with non significant difference as regard sodium. 4- As regard histopathological changes: A- Skin at both contact sites: Microscopic examination of hemotoxylin and eosin stained sections of the skin of rats of all the electrified groups at both contact sites (inlet and exit) showed splitting, honey comb appearance (Swiss-chess appearance), total loss and detachment areas of the keratin layer. Elongated pyknotic keratinocyte with vertical streaming, vacuolated cytoplasm with central nucleus, total loss and detachment areas were the observed changes in the epidermis. While the dermis was homogenized and vacuolated. B- Skeletal muscle at both contact sites: Microscopic examination of the skeletal muscle at both contact sites of rats of both electrocuted groups showed necrosis, degeneration, fragmentations with shrinkage of myocytes, and contraction bands. C- Heart: Microscopic examination of the heart specimens of the rats (of all electrified groups except IId &IIId subgroups which appeared histologically normal) showed areas of interstitial hemorrhage. Some cardiac myocytes appeared necrotic and fragmented. The nuclei were square or rounded in some areas. Myocardial waviness and contraction bands were also noted in other areas. Marked congestion of the blood vessels was observed in some rats of each subgroup beside the previous changes{IIa(18.75%),IIb(25%),IIc(18.75%),IIe(37.5%),IIIa(25%),IIIb(25%),IIIc(18.75%)) and IIIe(43.75%)}. D- Brain: Microscopic examination of the brain specimens of the rats (of all electrified groups except IId &IIId subgroups which appeared histologically normal) showed tearing in brain substance with shrinkage of pyramidal and granular cells in some areas. Other areas showed distorted pyramidal cells with deeply stained shrunken nuclei and cytoplasm surrounded by vacuolations. There was degeneration of some granular cells which appeared hazy ghost without nucleus. Marked congestion of the blood vessels was observed in some rats of each subgroup beside the previous changes {IIa (18.75%), IIb (25%), IIc(18.75%), IIe(37.5%), IIIa(25%), IIIb(25%), IIIc(18.75%) and IIIe(43.75%)}. 5- As regard histochemical changes: A- Skin at both contact sites: The both electrocuted groups showed weak PAS reaction in keratin and dermal layers B- Skeletal muscle at both contact sites: There were weak PAS reactions in fragmented and necrotic myocytes in both electrocuted groups. C- Heart: All the electrified subgroups of group II and group III (except IId and IIId which had normal reaction) showed weak PAS reactions in degenerated and fragmented areas in comparison with the control Brain: All the electrified subgroups of group II and group III (except IId and IIId which had normal reaction) showed weak PAS reaction in granular cells especially degenerated ones when compared with control. 6- As regard immunohistochemical examination: A- Skin at both contact sites: Both electrocuted groups showed Positive immune-reaction for caspase-3. This was detected in some cells when compared with the control group. B- Skeletal muscle at both contact sites: There was positive immune-reaction for caspase-3 detected in the cytoplasm and some nuclei of skeletal muscle fibers in both electrocuted groups when compared with the control group. C- Heart: There was positive immune-reaction for caspase-3 detected in the cytoplasm and some nuclei of cardiac muscle fibers in all the electrified subgroups of group II and group III (except IId and IIId which had negative reaction) in comparison with the control group. D-Brain: Positive immune-reaction for caspase-3was detected in some nerve cells of rats in all the electrified subgroups of group II and group III (except IId and IIId which had negative reaction) in comparison with the control group. metal traces