Research On Cardiac Ultrastructure And Changes Of HSP70, HIF-1Alpha Expression In Electric Shock Dead Rat

Objective: Death as a result of current is called electrocution.electrocution body signs have current typical porphyry, electric bright scars,shock pattern and skin metallization, etc. Current spot is the mainmorphological basis for diagnosis of death electric shock death, therefore, tofind and extract the current damage skin, microscopy confirmed the currentspot are the key to the diagnosis of electric shock death. But not every case ofelectric shock to death in the practical case had current spot, and it also canappear after the death of shock current spot; At present the lack of current spotshock death and lifetime and after the shocks of identification is a key problemfor forensic pathology identification, is also a problem urgently to be solved inforensic medicine. At present this kind of case is mainly combined with thecase, vulnerable people, get an electric shock the scene and body inspectionetc. to make a comprehensive judgment. And forensic pathology is still lack ofa more specific morphology or other indicators provide the basis for diagnosis.This experiment on the basis of model rats shock death, using HE stainingand transmission electron microscope and immunohistochemical stainingmethod, observing the morphological change of heart tissue in theelectrocution and a shock after the death. Through the observation of HSP70,HIF-1α, explore the different change in electrocution and a shock after thedeath，Provide certain diagnostic significance for forensic identification.Methods:56health SD rats, the weight is220g±10g, male and femaleunlimited, Fed7days to adapt to the environment, randomly divided into7groups, each group of8. Preparation of the model with a homemade electricshock devices.Control group, the30min after death control group, the60min after deathcontrol group, control group adopts after intraperitoneal injection of1ml chloralhydrate anesthesia supine fixed in rats on the shelf, will be on the sideof the front and hind legs do unhairing process using hair removal creams,beheaded kill rats, take its heart after thoracotomy, locally based part cut into0.5-1mm3(after) small2-3pieces, into a small bottle of4%glutaraldehyde,line for transmission electron microscope. The heart of the remaining localskin and body fixed in4%paraformaldehyde, the preparation of paraffinsection, HE staining observation, immunohistochemical method to observe theheart HSP70, HIF-1alpha expression. the30min after death control group andthe60min after death control group used the same method to be put to death inthe rats.Placed at room temperature to the corresponding time points after takeits heart and skin, observe with the control group.The electrical shock group：Anesthetized rats by intraperitoneal injectionof1ml chloral hydrate, then the rat in supine position fixed in rat frame,Willbe on the side of the front and hind legs using hair removal creams to woolprocessing connected self-made electric equipment，After a closed circuit witha220V voltage shock in rats2minutes to kill.After turning off the power andretreat the shock device immediately draw materials. The experiment contentwas the same as the control group.The0min after death electrical shock group, the30min after deathelectrical shock group and the60min after death electrical shock group:decapitated the rats after anesthesia by1ml intraperitoneal injection of chloralhydrate and fixed them on rat shelves supinely, do unhairing process. Shockedthe rats in the group of electric shock instantly with a220V household voltagefor two minutes, fixed them on rat shelves supinely after turned off the powerand removed Electrical equipment, the experiment contents such as drawmaterials instantly reference to the control group. Shocked the rats in theother two groups with a220V household voltage for two minutes, fixed themon rat shelves supinely after turned off the power and removed Electricalequipment, the experiment contents such as draw materials instantly referenceto above method.With “SD” indicates the data, statistical analysis was performed using SPSS16.0statistical software, using one-way ANOVA compared the mean ofeach group，for pairwise comparisons using the least significant differencemethod (least significant difference, LSD). With p<0.05indicated there werestatistically significant differences.Results:1The basic performance of shock rats and shock observation of the skinShock after death group of rats live ankylosing jitter, high upwarp tail, apale yellow urine, some rats have defecate eduction, limbs had burn shock；Current spot in accordance with line contact conductor walk, color showssallowness, qualitative hard, dry, central sag, slightly uplift, around the edgeof obtuse, with clear boundary between the surrounding tissue. Shock afterdeath group of rats also appear ankylosing jitter, urine and stool.Current spotalso agree with line contact conductor walk, qualitative hard, dry, central sag,with a clear demarcation between the surrounding tissue.2The result of HE staining2.1The change of HE staining in skin pathologyControl group of HE staining, we found that epidermis cells showednormally, arranged in neat order and no fracture, meanwhile, the staining ofcytoplasm and nucleus were normally and uniform under the light microscopyobservation.The electrical shock groups were observed under light thinning of theskin cell fusion, dense, deeply staining, cell polarity is changed to change, ismost evident in basal layer cells, basal layer cells and nuclei are deep,longitudinal elongation and serious distortionThe0min after death electrical shock group were observed under lightsee thin skin cell fusion, dense, dark stain, unclear boundaries between cells,skin cells cytoplasm homogenization, skin cavity formation, basal layer cellsand nuclei are deep, longitudinal elongation and serious distortion, nuclearflow performance.2.2The changes of HE staining in cardiac pathologyControl group of myocardial tissue structure is clearly visible, myocardial cell size is consistent, is for the center with myocardial arteriovenous funicularlined up, after the death of30minutes,60minutes after the death ofmyocardial cell dyeing only part of the area is edema, eosinophilic changeperformance gradually.The electrical shock group of myocardial cells in interstitial edema,cytoplasm staining, lighter nuclei and increase, myocardial layer fractureperformance, part of the myocardial cells with eosinophilic change.The0min after death electrical shock group of heart muscle cells withmild edema, cytoplasm staining, lighter nuclei and increase, part of themyocardial cells with eosinophilic change; The30min after death electricalshock group and the60min after death electrical shock group of myocardialcell dyeing only part of the area is edema, partial eosinophilic change. Afterthe death of an electric shock each myocardial no obvious fracture.3The results of heart by electron microscopyThe control group were observed by electron microscopy there was noabnormality in fibromuscular stroma, and no edema in perivascularinterstitial,the vascular endothelium cells pinocytosis vesicles were in goodorder, no significant changes around capillaries, structure was clear,the line ofZ and M were clearly visible without fracture.The electrical shock group was observed by electron microscopy thatmyofibril was broken and dissolved to disappear; mitochondrial ridges andmembrane was dissolved to disappear, the dropsy observed in interstitial,fibromuscular, perivascular interstitial and surrounding capillaries; thevascular endothelium cells pinocytosis vesicles were densely arranged,surrounding capillaries structure fuzzy and chaos, the line of Z and M wasfuzzy derangement visible with fracture.The0min after death electrical shock group was observed that nuclearwas side shift；muscle fiber was showed dropsy; mitochondrial ridges andmembrane dissolved to disappear;the line of Z and M was fuzzy derangementvisible with fracture by electron microscopy. 4The results of immunohistochemistryHIF-1alpha protein expression in myocardial cells as the cytoplasmstaining, the control group, the30min after death control group, the60minafter death control group myocardial cell death dyeing is less, no significantdifferences between groups. the electrical shock group and the microscopicobservation of myocardial cell cytoplasm staining enhancement, increasedsignificantly compared with controls, with statistical difference (P<0.001);The0min after death electrical shock group has positive expression, comparedwith the control group with statistical significance (P<0.01), The30min afterdeath electrical shock group,the60min after death electrical shock group andthe control group was no significant difference.HSP70protein expression in myocardial cells of cytoplasm staining, thecontrol group, the30min after death control group, the60min after deathcontrol group accidental cytoplasm yellow dye, positive staining is notobvious, no significant differences between groups. the electrical shock groupenhanced cell death group yellow, increased significantly compared withcontrols, with statistical difference (P <0.001); The0min after death electricalshock group has positive expression, compared with the control group withstatistical significance (P<0.01), The30min after death electrical shockgroup,the60min after death electrical shock group and the control group wasno significant difference.Conclusions:Lifetime shock and after shocks are current spot, so its not as a basis todistinguish the lifetime shock and after shocks. Cardiac death and shock theexpression of HSP70and HIF-1alpha protein than electric shockssignificantly increased again after the death of a different time, so the electricshock after the death of death and the differential diagnosis of electric shockhas a certain significance.