RESUMO
Objective To investigate the relationship between K+ concentration in rabbit vitreous humor and postmortem interval (PMI) under different ambient temperature. Methods Rabbit corpses were stored at 5℃ , 15℃ , 25℃ , and 35℃ after execution, and 80~100μL vitreous humor was extracted from each eye of the rabbit in turn every 12 hours. The concentrations of K+ were examined by Modular DPPI automatic biochemistry analyzer. The Interpolation Functions were used to analyze the statistical relationship between PMI and K+ concentration under different temperature. Results In each animal group, K+ concentration increased with PMI. Equation was obtained after interpolation analysis on range of temperature 5℃ ~30℃ . The three-variable quintic surface equation was f(x,y)=-1.998e14+1.345e12x+5.902e13y+0.005585x2-4.509e11xy-3.876e12y2-0.0002868x3+0.003545x2y+4.406e10xy2-1.746e10y3+2.669e-6x4-1.568e-5x3y-0.0001771x2y2-1.64e9xy3+6.669e9y4-8.672e-9x5+4.467e-8x4y+2.354e-7x3y2+2.459e-6x2y3+2.05e7xy4-1.214e8y5(R2=0.9956), x stands for temperature, y stands for K+ concentration, f(x,y) stands for PMI. Conclusion The rule of K+ concentration changes at ambient temperature complied with three-variable quintic surface equation distribution. Measurement of interpolation function may be used for PMI estimation at different ambient temperature.
RESUMO
Objective To investigate the relationship between Ct value of mice liver and postmortem interval (PMI) under various ambient temperatures. Methods mice were stored at 10℃, 15℃, 20℃, 25℃ and 30℃ after execution, and total RNA was extracted from mice liver every 6 hours (PMI 6h to 72h). The levels of 18s rRNA were examined using real-time PCR. The results were expressed by cycle threshold (Ct) value to explore relationship between PMI and Ct value, and the interpolation functions were established to estimate PMI. Results In each group, Ct value increased with PMI increased. Surface equation was obtained after interpolation analysis on temperature range 10℃~30℃. The three-variable quintic surface equation was f(x, y)=-426.9+30.82x+44.48y-1.297x2-1.837xy-1.388y2+0.034 38x3+0.038 17x2y+0.038 67xy2+0.028 77y3-0.000 612 9x4-3.897e-7x3y-0.001 223x2y2+0.000 256 6xy3-0.000 537 4y4+3.606e-6x5-2.846e-6x4y+1.009e-5x3y2-3.439e-6x2y3-2.556e-7xy4+2.664e-6y5(r2=0.999 4). Conclusion The rule of Ct value changes at ambient temperature complied with three-variable quintic surface equation distribution. Measurement of interpolation function may be used for PMI estimation at ambient temperature.
RESUMO
Objective To investigate correlation between the changes of oxidation reduction potential (ORP ) values of heart blood in rabbits after death and postm ortem interval (PMI) at different temperatures. Meth-ods Forty-eight rabbits were random ly divided into 6 groups and sacrificed by air em bolism . Blood sam-ples were taken from the right ventricle of each rabbit and stored at different temperatures of 10, 15, 20, 25, 30and 35℃, respectively. Every 4 hours from 0h to 132 hpostm ortem , the ORP values of the blood samples were measured at different intervals by PB-21 electrochem ical analyzer. The curvilinear regres-sion equation was established by SPSS 17.0software. The surface equation and 3D surface diagram were established by MATL A B7.10.0software. Results The ORP values at different temperatures of heart blood in rabbits were highly correlated with the PMI. The ORP values rised obviously when the temper-ature was high and rised slowly when the temperature was low. The surface equation and 3D surface diagram were obtained. Conclusion The surface equation and 3D surface diagram of ORP values and PMI may be used for PMI estimation at different temperatures.