Research Progress of Forensic Diagnosis Approaches of Early Acute Myocardial Infarction.

The postmortem diagnosis of acute myocardial infarction (AMI), especially the postmortem diagnosis of early AMI that died immediately after onset or within 1 hour, has always been a difficulty in forensic identification. This article reviews the forensic application of diagnosis and analysis methods for AMI postmortem diagnosis including autopsy imaging, histomorphology, immunohisto-chemistry, biochemical marker and molecular biology diagnosis, and explores the feasible scheme of early postmortem diagnosis in AMI.

Temporal expression of wound healing-related genes inform wound age estimation in rats after a skeletal muscle contusion: a multivariate statistical model analysis.

Although many time-dependent parameters involved in wound healing have been exhaustively investigated, establishing an objective and reliable means for estimating wound age remains a challenge. In this study, 78 Sprague-Dawley rats were divided randomly into a control group and contusion groups at 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, and 48 h post-injury (n = 6 per group). The expression of 35 wound healing-related genes was explored in contused skeletal muscle by real-time polymerase chain reaction. Differences between the groups were assessed by partial least squares discriminant analysis (PLS-DA). The results show that the samples were classified into three groups by wound age (4-12, 16-24, and 28-48 h). A Fisher discriminant analysis model of 14 selected genes was constructed, and 94.9% cross-validated grouped cases were correctly classified. A PLS regression analysis using 14 genes showed reasonable internal predictive validity, with a root mean squared error of cross-validation of approximately 8 h. To examine whether the prediction models were capable of analyzing new (ungrouped) cases, an external validation was carried out using the expression data from an additional 30 rats. Approximately 76.7% of ungrouped cases were correctly classified, which was a lower proportion than that for cross-validation. Similarly, the prediction results of the PLS model showed lower relatively external predictive validity (root mean squared error of prediction = 11 h) than internal predictive validity. Although the prediction results were less accurate than expected, the gene expression modeling and multivariate analyses showed great potential for estimating injury time. These multivariate methods may be valuable when devising future wound time estimation strategies.

An "up, no change, or down" system: Time-dependent expression of mRNAs in contused skeletal muscle of rats used for wound age estimation.

The combined use of multiple markers is considered a promising strategy in estimating the age of wounds. We sought to develop an "up, no change, or down" system and to explore how to combine and use various parameters. In total, 78 Sprague Dawley rats were divided randomly into a control group and contusion groups of 4-, 8-, 12-, 16-, 20-, 24-, 28-, 32-, 36-, 40-, 44-, and 48-h post-injury (n=6 per group). A contusion was produced in the right limb of the rats under diethyl ether anesthesia by a drop-ball technique; the animals were sacrificed at certain time points thereafter, using a lethal dose of pentobarbital. Levels of PUM2, TAB2, GJC1, and CHRNA1 mRNAs were detected in contused muscle using real-time PCR. An up, no change, or down system was developed with the relative quantities of the four mRNAs recorded as black, dark gray, or light gray boxes, representing up-, no change, or down-regulation of the gene of interest during wound repair. The four transcripts were combined and used as a marker cluster for color model analysis of each contusion group. Levels of PUM2, TAB2, and GJC1 mRNAs decreased, whereas that of CHRNA1 increased in wound repair (P<0.05). The up, no change, or down system was adequate to distinguish most time groups with the color model. Thus, the proposed up, no change, or down system provide the means to determine the minimal periods of early wounds.