Forensic Analysis of Sudden Death Associated with Sexual Activity.

OBJECTIVES: To analyze the characteristics of sudden death associated with sexual activity to provide recommendations for forensic identification. METHODS: A retrospective analysis was conducted on autopsy cases accepted by Forensic Identification Center of Huazhong University of Science and Technology from 1998 to 2018, and a total of 15 cases of sudden death associated with sexual activity were screened out. The general information, case data and pathological changes of 15 cases were collected to find the relationship between sexual activity and sudden death. RESULTS: The ratio of male to female was 1.5∶1. The average age of males was 50.1 years and that of females was 35.0 years. Coronary artery diseases and brain diseases accounted for most of the cases (12/15). Sexual partners were associated with locations of deaths and body dumping behaviors. CONCLUSIONS: Sudden death associated with sexual activity, although rare, may occur in people over 30 years old with pre-existing heart or brain diseases, which should be paid attention to in forensic practice.

[Changes of cyclin D1 expression following human brain contusion].

OBJECTIVE: To study the relationships of Cyclin D1 expression with the posttraumatic intervals (PTI) following the cerebra, brainstem or cerebella contusion in human. METHODS: 88 cases of brain contusions of the closed head injury were investigated with pathological and Cyclin D1 immunohistochemistry methods. The results were analyzed by image analysis technique (IAT). RESULTS: The immunoreactivity of Cyclin D1 was almost disappeared in the core cells of the brain contusion. Cyclin D1-positive cells started to increase in the boundary of the brain contusion in the 1h group. Cyclin D1-positive cells were increased significantly in the 3 h-30 d groups and maintained at a high level in the boundary of the brain contusion of those groups. It is suggested that the Cyclin D1-positive cells were primarily origin from microglia and other glia. A few neurons expressed Cyclin D1. CONCLUSION: Cyclin D1 can express in several kinds of brain cells following the contusion, especially in the glia cells. Cyclin D1-positive cells were increased obviously and rapidly after injury, so it could be used as a reference marker for early stage brain injury.

[Relationship between expression of nestin in experimental brain contusion and injury time].

OBJECTIVE: To observe the alteration of nestin intervals in the experimental traumatic brain injury and investigate its relation to the injury intervals. METHODS: The rat brain contusion was conducted by falling impact injury. After various survival interval (0.5, 6, 12 h and 1, 3, 7, 14, 28 d), immunohistochemical SP method was used for observing the expression of nestin in the cortex, hippocampal dentate gyrus and the corpus callosum on injury side. RESULTS: Expression of nestin positive cells increased at 0.5 h and reached the maximum level in 7 d after brain contusion, then the expression decreased gradually. The intensity of nestin staining in the the cortex and the hippocampal dentate gyrus decreased to normal on 28 d. As to the corpus callosum of injury side it remained weak on 28 d. CONCLUSION: The changes of nestin immunohistochemical staining can be used as an index for forensic estimation of early injury time.

[A primary study on the ARP-SRP gene expression profiling of brain injury by cDNA microarray].

OBJECTIVE: To screen the differential expression of apoptosis-related protein and stress response protein(APR-SRP) genes after human brain injury by cDNA microrarray. METHODS: The total RNAs were isolated from normal and injured brain tissues of a car-accident victim, and were purified to obtain mRNAs by Oligotex. Both mRNAs from the tissues of the injured and the normal tissue were reversely transcribed to cDNAs with the incorporation of fluorescent dUTP to prepare the hybridization probes. The probes from normal tissue was labeled with Cy3-dUTP, that from the injured tissue with Cy5-dUTP. The mixed probes were hybridized to the BioDoor Chip ARP-SRP-1.0S, a cDNA microarray which contains 77 apoptosis related protein genes and 23 stress protein related genes. After high-stringent washing, the cDNA microarray was scanned for the fluorescent signals and showed differences between two tissues. RESULTS: Among the 100 target genes, Only CLN2 gene (Homo sapiens lysosomal pepstatin insensitive protease gene) showed distinct deference in expression level between the brain injury and normal tissues. CONCLUSION: cDNA microarray analysis indicated that CLN2 gene, which is correlated to a fatal childhood neurodegenerative disease, might be related to the brain injury. The expression level of CLN2 gene was significantly decreased in brain injured tissue in comparison to normal tissue. Further analysis of this gene will be helpful to understand the molecular mechanism of brain injury and utilization in forensic medicine.

[The mast cell and trauma].

Mast cell(MC) takes an important role in trauma and the process of wound healing, and the pathophysiology reaction has a relationship to the time since trauma, which is helpful to determine the post-trauma and postmortem interval, and to distinguish the wound shaped whether before or after death. In this paper, the role of MC and its chemic medium in the process of wound healing, scar shaping, postburns inflammatory response, healing of bone fracture, as well as the signification for forensic medicine and the progress of researching in this field were reviewed.