Skin Ultrastructure and the Changes of HIF-2α, H-FABP Expression in the Myocardium of Electric Shock Death Rats / 法医学杂志

Objective To observe the skin ultrastructure change of electric shock death rats and to test the expression changes of hypoxia-inducible factor-2α （HIF-2α） and heart type-fatty acid-binding protein （H-FABP） of myocardial cells, in order to provide basis for forensic identification of electric shock death. Methods The electric shock model of rats was established. The 72 rats were randomly divided into control group, electric shock death group and postmortem electric shock group. Each group was divided into three subgroups, immediate （0 min）, 30 min and 60 min after death. The skin changes of rats were observed by HE staining, the changes of skin ultrastructure were observed by scanning electron microscopy, and the expression of HIF-2α and H-FABP in rats myocardium was tested by immunohistochemical staining. Results The skin in the electric shock death group and postmortem electric shock group had no significant difference through the naked eye or by HE staining. Under the scanning electron microscope, a large number of cellular debris, cells with unclear boundaries, withered cracks, circular or elliptical holes scattered on the cell surface and irregular edges were observed. A large number of spherical foreign body particles were observed. Compared with the control group, the expression of HIF-2α in all electric shock death subgroups increased, reaching the peak immediately after death. In the postmortem electric shock group, HIF-2α expression only increased immediately after death, but was lower than that of electric shock death group （P<0.05）. Compared with the control group, the expression of H-FABP in all subgroups of electric shock death group and postmortem electric shock group significantly decreased. The expression of H-FABP in all subgroups of electric shock death group was lower than that of the postmortem electric shock group （P<0.05）. Conclusion Electric shock can increase HIF-2α expression and decrease H-FABP expression in the myocardium, which may be of forensic significance for the determination of electric shock death and identification of antemortem and postmortem electric shock.

Estimation on Formation Time of Thrombus / 法医学杂志

OBJECTIVES@#To observe the changes of the formation time of venous thrombus in rats, and to provide new ideas and methods for the estimation on thrombus formation time of the forensic cases died from thrombosis.@*METHODS@#Totally 80 rats were randomly divided into 10 groups （0 h, 3 h, 6 h, 12 h, 1 d, 3 d, 1 week, 2 weeks, 3 weeks and 4 weeks after operation）. A vein thrombosis model was established by the "narrow" method. The processes of thrombosis, organization, recanalization and the features of change on hemosiderin and calcium salt were observed by HE stain, Perls stain and Von Kossa stain. The expression changes of CD61, α-SMA and CD34 were observed by immunohistochemical staining technique.@*RESULTS@#Platelets adhered to the exposed blood vessel intima 3 h after operation, and platelet trabeculae were formed by the repeated accumulation of platelets 1 d after operation. The thrombus organization formed through the fibroblasts from vessel wall that grew into the interior of the thrombus 3 d after operation. Endothelial cells covered the surface of thrombus and then the new blood vessels were reformed, and the vessels were reconstructed. The expression of CD61 upregulated at the stages of the thrombus formation （3 h） and thrombus reformation （4 weeks）, and reached the peak 1 d after thrombus formation. The release of hemosiderin and the initial expression of α-SMA were detected 3 d later. Calcium deposit and expression of CD34 were observed 1 week later.@*CONCLUSIONS@#The hemosiderin, calcium salt, CD61, α-SMA and CD34 show time-dependent changing characteristics, which is expected to provide a reference for the estimation on thrombus formation time of the forensic cases died from thrombosis.

Construction of semantic relations of the top-level ontology of military medicine / 军事医学

Objective To explore a construction method of semantic relations of the top-level ontology of military medicine in order to construct the top-level ontology semantic network.Methods The military medical corpus was selected,and the relationships between the concepts were extracted using text analysis.On the basis of inheriting the semantic relations of UMLS,the special semantic relations of military medicine were added.Results A method of establishing the semantic relations of the top-level ontology of military medicine was proposed,the applicability of which was verified by example of the branch of military medical equipment.Conclusion The proposed method is effective and feasible,which can provide important support to the establishment of top-level semantic networks of military medicine.

Cardiac Ultrastructure and Changes of HSP70 and HIF-1α Expression in Electric Shock Death Rats / 法医学杂志

OBJECTIVE@#To observe cardiac ultrastructure and the expression of heat shock protein 70 (HSP70) and hypoxia inducible factor-lα (HIF-lα) in electric shock death rats and to explore the application of these indexes as the basis of medical identification in electric shock death.@*METHODS@#Seventy-two SD rats were randomly divided into electric shock death group, postmortem electric shock group and the control group. The changes of myocardial ultrastructure were observed by transmission electron microscope, and the expressions of myocardial HSP70 and HIF-1α were observed by immunohistochemical technology.@*RESULTS@#Myocardial myofibril fracture, mitochondrial cristae and membrane dissolution, and disordered arrangement of Z lines and M lines were observed in electric shock rats. HSP70 and HIF-lα were strong positive expressions in the electric shock death group, significantly compared with the control and postmortem electric shock groups (P < 0.05).@*CONCLUSION@#The expressions of HSP70 and HIF-lα were obviously increased in electric shock death group, which may be used as the diagnostic indicator of electric shock death.

Dynamic changes of LDH and HBDH activity in rabbit serum after low voltage electrical injury / 法医学杂志

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.