Objective To study the relations between the site of head injury and the position of brain edema induced tentorial notch herniation (TNH). Method The formalin fixed brain specimens of 91 cases were cut either coronally, or sagittally or horizontally, according to different requirement. Then, the characteristics of injury were observed. Results There were three types of brain edema induced TNH after cerebral injury: 65 cases with anterior herniation (71.4%), 5 cases with posterior herniation (5.5%), and 21 cases with unilateral or bilateral total herniation (23.1%). Anterior herniation was notable among 16 cases with total herniation. Conclusion Frontotemporal anterior herniation was the most common type of TNH after cerebral injury. The occurrence of TNH was related to the site and manner of injury, as well as the strength of force and survival interval after injury.

Objective To investigate the value of diffusion-weighted magnetic resonance imaging (DWI) and apparent diffusion coefficients (ADC) in detecting metastatic lymph nodes from nasopharyngeal carcinoma (NPC),and predicting the response of these nodes to concurrent chemoradiation (CRT).Methods Eighteen patients with pathologically proven NPC received conventional magnetic resonance imaging (MRI) and DWI before treatment,weekly during treatment,and one month after treatment.DWI was performed using a single-shot echo-planar (SSEPI) MR imaging sequence with b values of 0 and 1500 s/mm2.ADC maps were reconstructed for all patients and ADC values were calculated for each lymph node and tongue muscle.Totally fifty-two morphologically abnormal lymph nodes were analyzed.The ADC values of the metastatic lymph nodes before treatment were compared between those with the short axis≥10 mm (n=32) and those with the short axis<10 mm (n=20),and the dynamic changes in ADC values of the lymph nodes before,during,and after therapy were observed and recorded.Results The average ADC of the 32 lymph nodes with the short axis ≥ 10 mm was (0.71±0.12) x 10-3mm/s,not significantly different from that of the 20 lymph nodes with the short axis < 10 mm [(0.73±0.16) x 10-3mm/s,t = 1.11 ,P =0.27].The average ADC values of these lymph nodes before treatment was significantly lower than that of the tongue muscle (t = 19.35,P < 0.0001).During CRT,the ADC values of the lymph nodes increased gradually,with the most evident change in the first two weeks before reaching a relatively flat plateau thereafter.The ADC value of the residual lymph nodes after CRT was significantly higher than that before treatment (t = 12.72,P < 0.0001),however,not statistically significant different from that of the normal tongue muscle (t = 0.34,P = 0.73).Conclusions DWI plays an important role in diagnosing the metastatic lymph nodes from NPC and is feasible for observation of the early response of the lymph nodes to IMRT,thus helping the clinicians make appropriate treatment planning and replanning in the course of radiotherapy.

Objective Investigating activity variance of PKC.AchE and HSP70 in different tissues of rabbits caused by dying from suspension of anterior limbs.in order to study how factors above contribute in the mechanism of death.Methods Suspend rabbit by its anterior limbs until it dies.and coilect tissue from its diaphragmatic muscle,intercostal muscle,myocardium,gastrocnemius,cerebrum,brain stem,liver,kidney and lung.In the control groups,collect same tissues of rabbits dying from strangulation,craniocerebral injury and diseases as contrast.Detect activity of PKC,AchE and HSP70 in tissues of those groups mentioned above by SP stain of immunohistochemistry.and statistically analyze result of detection by rank SUm test of independent samples of multi-groups.Results Compared with data from other control groups,there are more obvious expressions in following tissues of group of suspension:PKC in disphragmatic muscle,intercostal muscles and cerebrum(P＜0.05);AchE in disphragmatic muscles,intercostal muscles,myocardium,cerebrum,liver and nerve tract ofmuscles(P＜0.05);HSP70 in cerebrum,myocardium and lung(P＜0.05).Conclusion Through different mechanisms,PKC,AchE and HSP70 could take some certain contributions in death pmcess of suspension by anterior limbs,and the results above could offer some experimental evidences for related studies and medicolegal investigations.

Objective To study the pathological changes of the sudden death cases due to the dysplasia of the cardiac conduction system. Methods Using the newly established pathological sampling method by our research team, 26 hearts of unidentified sudden deaths excluding trauma, poisoning and diseases were collected and observed optically with H&E staining, Masson staining and immunohistochemical staining. Results Among the 26 cases, there were dysplasia in the cardiac conduction system,structural abnormalities, tissue or structure shift, fibrous cushion in the sinoatrial node and 9 cases have 2~3 abnormalities at the same time. Among the age groups from 16 to 30, 21 cases (80.8%) showed dysplasia of the cardiac conduction system. Conclusion The dysplasia of the cardiac conduction system may be one of the predominant reasons for the sudden death in young adults.

It is a challenge to determine the cause of death in cases caused by both injury and disease in forensic pathology examinations.Here,we retrospectively analyzed 140 such cases enrolled in the Sun Yat-sen University Forensic Identification Center from 2013 to 2021.It was found that the cases caused by both injury and disease accounted for 2.89%of the total number of cases during the same period.The male-to-female ratio was 5.09.Cardiovascular disease accounted for 71.43%of the death-leading diseases,and coronary heart disease accounted for 49.29%.Among the three types of injury and disease relationship,the proportion of disease-based and injury-assisted cases accounted for more than half(65.86%),and the proportion of injury and disease with the same effect cases was the least(12.14%).Medical treatment was involved in as more as 82.86%of the cases.Re-identification were carried out in 10.71%of the cases,53.33%of which were with a≤24-hour-survival time,higher than the proportion(20.80%)of this survival time in initial identification cases(x2 = 13.84,P = 0.000 2).This study revealed the epidemiological characteristics of cases caused by both injury and disease,and supplied useful data for improving the level of forensic identification in such cases.

ObjectiveTo clearly identify the difference between rescue injuries and agonal injuries and to avoid duplicate identifications and misidentifications. MethodsBased on the forensic pathological data of 5 923 cases of death cause identification from 2013 to 2022 in Sun Yat-sen University Forensic Identification Center and Guangzhou Tianhe District Branch of Guangzhou Public Security Bureau， this study retrospectively studied the characteristics of rescue injuries and agonal injuries seen in cause of death identification and their influence on cause of death identification. ResultsAmong all the 5 923 cases， 640 cases were found to have rescue injuries or agonal injuries， and 624 cases received treatment， of which 609 cases were found to have rescue injuries （97.60%）， 44 cases were found to have agonal injuries， and 13 cases were found to have both types of injuries. Among the 640 cases， 441 were male and 199 were female. The age of death was discontinuously distributed from 0 to 95 years old. The leading cause of death was disease， followed by mechanical injury and asphyxia. The main manifestations of rescue injuries were rib and sternum fractures， soft tissue injuries in the prechest area or face， and pericardial rupture. The most common injuries in agonal stage were falling after unconsciousness， inhalation of foreign body in respiratory tract or multiple violent injuries. Among the 640 cases， 19 cases were repeatedly identified， including 15 cases of rescue injuries， 6 cases of agonal injuries， and 2 cases of both types of injuries. Compared with the cases where neither type of injuries was detected， the repeated identification rate of treatment injuries and agonal injuries was significantly increased （χ²=4.04， P=0.044； χ²=43.49， P<0.001）. Among the 640 cases， 11 cases （1.72%） were misidentified as the initial injuries in the first identification， and 13 cases had combined rescue injuries or agonal injuries that were involved in death. ConclusionsBy elucidating the epidemiological characteristics of the two types of injuries， this study proved that the two types of injuries were associated with higher rates of repeated identification and misidentification， which provided a reference for reducing repeated identification and misidentification and improving the accuracy of cause of death identification.