Temperature‐Dependent Postmortem Changes in Human Cardiac Troponin‐T (cTnT): An Approach in Estimation of Time Since Death

Abstract

Estimation of time of death is an indispensible requirement of every medico-legal autopsy, but unfortunately, there is not a single method by which it could be determined accurately. This study focused on the temperature-dependent postmortem degradation of cardiac troponin-T and its association with postmortem interval (PMI) in human. The analysis involved extraction of the protein, separation by denaturing gel electrophoresis (SDS-PAGE), and visualization by Western blot using cTnT-specific monoclonal antibodies. The area of the bands within a lane was quantified by scanning and digitizing the image using Gel Doc (Universal Hood). The results indicate a characteristic banding pattern among human cadavers (n = 6) and a pseudo-linear relationship between percentage of cTnT degradation and the log of the time since death (r > 0.95), which can be used to estimate the postmortem interval. The data presented demonstrate that this technique can provide an extended time range during which PMI can be more accurately estimated.

Postmortem muscle protein degradation in humans as a tool for PMI delimitation

“…Similar to desmin, the cTnT degradation products appeared earlier in humans than in pigs (e.g., cTnT dp2 at 28.2 and 125.7 °d, respectively). Temperature- and PMI-dependent degradation kinetics of cTnT have recently been found in explanted human heart tissue [ 27 ]. Note that cardiac troponin T is not limited to cardiac muscle but also occurs in skeletal muscle tissue [ 25 ].…”

Forensic study of skin postmortem changes as a supplementary test to determine postmortem interval (first 78 hours)

“…21 histological criteria were analyzed by Fisher test; statistical significance (p <0.001) with a reliability of 94.61% was achieved in 15 of the 21 parameters studied. These parameters were statistically significant: 1,4,6,7,8,9,10,11,12,15,16,17,19,20, and 21, which correspond to presence of corneal and granular cell layers, topography of hydropic degeneration of the spinous layer, orientation of the collagen fibers, and percentage of: Early and advanced hydropic degeneration of spinous cells, loss of morphology of basal layer, melanocyte degeneration, hyalinization of the collagen fibers, hydropic degeneration of sweat glands, detachment and necrosis of the sebaceous gland, necrosis of follicles, loss of adipocyte morphology, and conservation of hypodermic lobular structure. Figure 1 shows the progression of post-mortem changes in the epidermis with progressive loss of granular cell layer (gcl), followed by hydropic degeneration of spinous cell layer (scl), and loss of morphology of basal layer (bl).…”

“…There are multiple approaches for determining the post-mortem interval [7]: Determination of vitreous concentrations of glucose [8], sodium and potassium [9,10]; the degree of corneal opacity and fundus analysis [11]; spectrophotometric analysis of lividity [12]; the degree of pleocytosis in cerebrospinal fluid [13]; potassium and glucose concentration in synovial fluid [14]; estimation of the volume and number of adrenal chromaffin cells [15,16]; determination of myoglobin in thyroid, lungs and blood [17]; degree of mobility of the nasal cilia [18]; rt-pcr analysis of genes involved in circadian cycles [19]; post-mortem muscle mechanical stimulation [20]; determination of cardiac troponin i [21], and many others.…”

Characterization of postmortem biochemical changes in rabbit plasma using ATR-FTIR combined with chemometrics: A preliminary study

“…Indeed, numerous studies have proposed that some specific proteins or their degradation products in multiple biological specimens may serve as biomarkers for PMI estimation. [35][36][37][38]. Nevertheless, there is so far a lack of parallel investigations on animal or human blood specimens.…”