OBJECTIVETo explore the acting mechanism of electrical field in electrical injury.

METHODSThirty-six New Zealand white rabbits were employed in the study and were randomly divided into 7 groups. There were 12 rabbits in group 1 and 4 in each group of other 6 groups. The animal model of nonthermal electrical injury previously replicated was employed in the study. Experiment with paralleled muscular fibers in electrical field was carried out in groups 2 approximately 4, while that of vertical muscular fibers in electrical field in groups 5-7. Anatomical examination was done to determine the index of deep burn injury (IDBI) in all groups of rabbits at 0, 2 and 24 postburn hour (PBH). Histological and ultrastructural examination, gamma picturing and isotope scanning with 99mTc were done in group 1 at 2 PBH.

RESULTSThere was no obvious skin injury in the white rabbits in group 1. Deep tissue necrosis was identified under the small electrode. Constant muscular spasm was observed in the inner side of the thigh. The muscles in paralleled electrical field suffered more severe injury than those in vertical one. Tissue injury was more severe in those areas with higher current density, less soft tissue, and also in the central area of the axis of the electric field. There were obvious changes in the perfusion and blood pool phases in these areas as observed with the aid of 99mTc. Light microscopic examination revealed swelling and necrosis of muscular fibers. Under electron microscopy, it was found that there were edema and dissolution with separation of lipid molecular layers of cell membrane, Shortened nucleus with partial dissolution of nuclear membrane, increased heparin granules within nucleus, swelling of mitochondria and endoplasmic reticulum, myofilament dissolution, expanded gap between myofilament and decreased number of heparin granules.

CONCLUSIONNon-thermal tissue injury in the electrical field, in terms of cell, ultrastructural and molecular levels, was induced and aggravated by all the factors constituting high voltage electrical field.

Animals ; Electric Injuries ; pathology ; Lower Extremity ; injuries ; Necrosis ; Rabbits ; Soft Tissue Injuries ; pathology

Electric Injuries ; pathology ; Electroretinography ; Humans ; Macula Lutea ; pathology ; Male ; Middle Aged ; Tomography, Optical Coherence

It is the intent of this study to estimate the progression or regression of edema at the bedside continuously. Based on the theoretic model, the Adaptive Genetic Algorithm (AGA) has been applied in the calculation of conductivity reconstruction. Dynamic crossover and mutation operators which are based on Haiming Distance are brought forward in this paper to maintain generation's diversity. Then, both AGA and Standard GA (SGA) have been applied in the conductivity reconstruction of edema in human brain. It is shown that AGA not only has attained a higher degree of efficiency but also has enhanced the capability to converge to the best answer.
Algorithms ; Brain Injuries ; complications ; pathology ; Computer Simulation ; Edema ; pathology ; Electric Impedance ; Humans ; Models, Biological

Objective To summarize the characteristics of cases of electrocution due to direct current （DC） electronic hunter, and to provide references for forensic identification. Methods Four cases of electrocution due to DC electronic hunter were collected. Statistical analysis was carried out from the perspective of the scene and electric marks distribution, damage characteristics and histopathological changes. Results All the 4 cases of electrocution were accidental events. There were multiple electric marks, most of which were located in the lower limbs with serious damage. Some strip type electric marks were visible. Conclusion The distribution, morphological characteristics and severity of the electric marks caused by DC electronic hunter are different from those of the ordinary low-voltage alternating current damage. It is alerting that there would be actions of destroying the scene and abandoning the corpse in such cases.
Cadaver ; Electric Injuries/pathology* ; Electricity/adverse effects* ; Fatal Outcome ; Forensic Pathology/methods* ; Humans ; Lower Extremity

OBJECTIVETo study the pathologic findings seen in lethal cases due to accidental electrocution.

METHODSThe macroscopic and microscopic findings in 16 autopsy cases died of electrocution encountered during the period from January, 2001 to July, 2008 were retrospectively reviewed.

RESULTSTypical electric marks were found on gross examination in 5 of the 16 cases studied. Histologically, 11 of the 16 cases showed evidence of electric burn. The morphologic features of atypical electric marks varied. Simple epidermal exfoliation and color changes were relatively common. Pathologic changes in internal viscera included disarray of myocardial fibers. Rupture of myocardial fibers was readily identified than in non-electrocution death. Sometimes, focal interstitial hemorrhage and polarization of endothelial cells were seen.

CONCLUSIONSThe electric marks on the skin, as confirmed by histologic examination, remain important sequelae of electrocution. The pathologic changes seen in myocardium provide additional clues to the diagnosis.

Adolescent ; Adult ; Autopsy ; Burns, Electric ; pathology ; Child ; Child, Preschool ; Electric Injuries ; pathology ; Female ; Humans ; Male ; Middle Aged ; Myocardium ; pathology ; Retrospective Studies ; Skin ; pathology ; Young Adult

OBJECTIVE: To observe ultrastructure changes of electrical injury in rats. METHODS: An experimental model of rats suffered from the low voltage were designed. Ultrastructure changes of electrical injured tissues were observed under transmission electron microscope. RESULTS: (1) Plasma of epithelium was concreted in the affected areas and inner membrane system was broken. (2) Hypercontraction bands were observed in skeleton muscles. (3) There was dissolved necrosis and hypercontraction bands in the myocardium. (4) Vacuoles were found in plasma of endothelium of blood vessels on electrical current path, and myelin sheath of nerve fiber were loosed. CONCLUSION The above mentioned ultrastructure changes could be used as assistant diagnostic index of electrocution. The mechanism of the changes were discussed.
Animals ; Electric Injuries/pathology* ; Muscle, Skeletal/ultrastructure* ; Nerve Fibers/ultrastructure* ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To investigate the changes of creatine kinase-MB (CK-MB) and heat shock protein 60 (HSP 60) in rats without electric marks after electric injury, to identify the relationship of the CK-MB, HSP 60 and the time of electric injuries, and to evaluate the damage to cells after electric injury. METHODS: The animal model of electric injury without electric marks was established by alternating current (voltage 110 V). Automatic biochemistry analyzer was used to detect the serum CK-MB and immunohistochemical staining technology was used to analyze the tissues of myocardium and left lobe of liver. RESULTS: The amount of serum CK-MB was increased when the rats were injuried, and reached the peak at 30min. Then the amount of CK-MB began to decrease and showed a slight downward trend in 3-5 h after electric injury, and leveled off at 6 h. Immunohistochemistry staining also showed the changes of HSP 60 of rats' myocardial cells and hepatic cells regularly after electric injury. CONCLUSION The regular changes of serum CK-MB and tissular HSP 60 in rats can be used to diagnosis electric injury and assess the injury of internal organs after the electric injury without electric marks.
Animals ; Chaperonin 60/metabolism* ; Creatine Kinase, MB Form/metabolism* ; Electric Injuries/complications* ; Immunohistochemistry ; Liver/pathology* ; Myocardium/pathology* ; Rats

This is the statistical analysis about the medicolegal autopsy cases performed by the Department of Forensic Medicine, Seoul National University Medical College during the last 5 years. 1. The total number of cases was 330, among which male took 256(77.5%) cases, female 74(22.5%) cases. The natural death took 134(40.6%) cases, unnatural death 177(53.6%) cases. For remaining 19(5.8%) cases the cause of death was known, although thorough analyses including microscopic examination, toxicology study were done. The thirties were most as 25.4% of the total cases, and the forties followed the second. 2. The number of autopsy showed severe variation annually or monthly in a year. 3. Among unnatural death, death by violent injury took 87(49.2%) cases, asphyxia 48(27.1%) cases, intoxication 17(9.6%) cases and death by thermal injuries or electric injuries 25(14.1%) cases. 4. Among natural death the abnormality in cardiovascular system were the most as 73(54.5%) cases, gastrointestinal system 38(28.4%) cases and central nervous system 12(8.9%) cases. 5. There were some differences between these and the data from other institute in the ratio of male to female, ratio of natural death to unnatural death and the ratio of specific cause of death among natural and unnatural death. 6. During this work, there were some difficulties in the aspect the irregularity of the work, in requesting toxicology and in the expense needed for the process. Considering the educational aspect for the students and the residents in pathology, performing medicolegal autopsy in medical college should be encouraged. The small number of autopsy and the closeness of the scene made the scene investigation possible in several cases, which is the ideal form that we must consider when we set up our system for the postmortem investigation.
Asphyxia ; Autopsy* ; Cardiovascular System ; Cause of Death ; Central Nervous System ; Electric Injuries ; Female ; Forensic Medicine ; Humans ; Male ; Pathology ; Seoul* ; Toxicology

AIMStudy on the relationship between the degraded spinal cord injuries and the changes of the motor evoked potentials (MEP) to prove the diagnosis and prognosis value of MEP.

METHODSAfter injury at T8-T9 cord using modified Allen's weight-drop method, 27 male SD rats were divided randomly into control group (n = 5), group A (50 gcf, n = 8), group B (70 gcf, n = 8) and group C (100 gcf, n = 6). MEPs elicited by monopolar transcortical stimulation were recorded continuously before injury, just after injury, 15 minutes, 1 hour, 3 hours and 6 hours after injury. The rate of the size of the bleeding or necrosis area to the total cord was also calculated.

RESULTSMEP had no significant change in the control group. The amplitude of MEP's early components in group A or group B decreased or even obliterated after SCI, and then partially recovered, while the late components were lost without any recovery signals. All animals in group C showed no MEP waves excepting 2 rats had recovery signals. The size of the cord injuries area increased according to the dropping force and was correlated significantly with the amplitude of the largest peaks of scMEP 1 hour after SCI (r = -0.821).

CONCLUSIONThe scMEP changes after SCI are correlated with the injury forces and the pathological changes in the cord, which indicates that scMEP can be used as an objective index for the cord functional monitoring.

Animals ; Electric Stimulation ; Evoked Potentials, Motor ; physiology ; Male ; Rats ; Rats, Sprague-Dawley ; Spinal Cord Injuries ; pathology ; physiopathology

OBJECTIVE: To investigate changes of LDH and HBDH activity in rabbit serum after non-thermal low voltage electrical injury and to provide diagnostic criteria for non-thermal low voltage electrical injury. METHODS: Forty New Zealand rabbits were randomly distributed into control group and electrical injury group (EI-groups; designated 7 time points: 0 h, 2 h, 4 h, 12 h, 1 d, 2 d, 3 d), 5 rabbits per each group. EI-groups were treated with the method of non-thermal low voltage electrical injury established in our laboratory. Ventricular blood (5 mL) was obtained under anesthesia at designated time points after electrical injury. The activities of LDH and HBDH were measured. RESULTS: Dynamic changes were observed with certain patterns from target serum enzyme activities after electrical injury. Compared with control group, the activities of LDH increased markedly at 4 h, 12 h, and on days 1, 2, and 3 after injury (4 h, 12 h, and day 1 P<0.01; day 2 and day 3 P<0.05). Activities of HBDH increased markedly at day 2 and day 3 after injury (P<0.05). The ratio of HBDH/LDH decreased markedly at 2 h, 4 h, and 12 h after injury (P<0.01). CONCLUSION Dynamic changes of LDH and HBDH activities may be useful in diagnosis of non-thermal low voltage electrical injury and in estimation of post injury intervals.
Animals ; Electric Injuries/enzymology* ; Female ; Forensic Pathology ; Hydroxybutyrate Dehydrogenase/blood* ; L-Lactate Dehydrogenase/blood* ; Male ; Rabbits ; Random Allocation