Comparison of Three Methods for Skeleton Age Estimation.

OBJECTIVES: To find the appropriate method for age estimation for different ages and sexes. METHODS: The costal cartilage, sternum and pubic symphysis of 91 unknowns from 2000 to 2020 from the Forensic Department of the Criminal Investigation Team of Shanghai Public Security Bureau were collected. Costal cartilage, sternal and pubic symphysis inferences were used to estimate the age, and the consistency between the estimated results and the actual physiological age of the unknowns was tested. The accuracy of age estimation of different samples was compared, and the relationship between accuracy and age and sex was analyzed. RESULTS: Using the costal cartilage method, the inference errors of males, females and the whole population under 40 years old were (0.608±2.298) years, (0.429±1.867) years and (0.493±2.040) years, while those over 40 years old were (-1.707±3.770) years, (-3.286±4.078) years and (-2.625±4.029) years. The differences between different age groups in these three populations were statistically significant (P<0.05). Using the sternum method, the inference errors of males and females under the age of 40 were (0.921±3.019) years and (0.452±1.451) years, while those over the age of 40 were (-5.903±5.088) years and (-1.429±2.227) years. The differences between different age groups in males and females were statistically significant (P<0.05). Using the pubic symphysis method, the inference errors of males and females under 40 years old were (-0.204±1.876) years and (0.238±2.477) years, while those over 40 years old were (1.500±2.156) years and (-2.643±4.270) years. The differences between different age groups in males and females were statistically significant (P<0.05). Using the sternum method and pubic symphysis method for age estimation of over 40 years old, the difference between different sexes was statistically significant (P<0.05). CONCLUSIONS: All three methods of age estimation are stable and effective and more accurate for people under 40 years old. For age estimation of unknowns over 40 years old, the pubic symphysis method is preferred in males and the sternum method is preferred in females.

ER stress-related protein, CHOP, may serve as a biomarker of mechanical asphyxia: a primary study.

The precise authentication of death from mechanical asphyxia (DMA) has been a complex problem in forensic medicine. Besides the traditional methods that concern the superficial characterization of the body, researchers are now paying more attention to the biomarkers that may help the identification of DMA. It has been reported that the extremely hypoxic environment created by DMA can cause the specific expression of mitochondria-related protein, which may sever as the biomarkers of DMA authentication. Since endoplasmic reticulum stress (ER stress) has been found to be related to the dysfunction of mitochondria, it is promising to look for the biomarkers of DMA among ER stress-related proteins. In this article, animal and cell experiments were conducted to examine how ER-mitochondria interaction may be influenced in the hypoxic condition caused by DMA primarily. Human samples were then used to verify the possible biomarkers of DMA. We found that ER stress-related protein CHOP was significantly up-regulated within a short-term postmortem interval (PMI) in brain tissue of DMA samples, which may interact with a series of ER stress- and mitochondria-related protein, leading to the apoptosis of the cells. It was also verified in human samples that the expression level of CHOP can sever as a potential biomarker of DMA within a specific PMI.