Comparative analysis between diatom nitric acid digestion method and plankton 16S rDNA PCR method / 法医学杂志

OBJECTIVE@#To compare and explore the application value of diatom nitric acid digestion method and plankton 16S rDNA PCR method for drowning identification.@*METHODS@#Forty drowning cases from 2010 to 2011 were collected from Department of Forensic Medicine of Wenzhou Medical University. Samples including lung, kidney, liver and field water from each case were tested with diatom nitric acid digestion method and plankton 16S rDNA PCR method, respectively. The Diatom nitric acid digestion method and plankton 16S rDNA PCR method required 20 g and 2 g of each organ, and 15 mL and 1.5 mL of field water, respectively. The inspection time and detection rate were compared between the two methods.@*RESULTS@#Diatom nitric acid digestion method mainly detected two species of diatoms, Centriae and Pennatae, while plankton 16S rDNA PCR method amplified a length of 162 bp band. The average inspection time of each case of the Diatom nitric acid digestion method was (95.30 +/- 2.78) min less than (325.33 +/- 14.18) min of plankton 16S rDNA PCR method (P < 0.05). The detection rates of two methods for field water and lung were both 100%. For liver and kidney, the detection rate of plankton 16S rDNA PCR method was both 80%, higher than 40% and 30% of diatom nitric acid digestion method (P < 0.05), respectively.@*CONCLUSION@#The laboratory testing method needs to be appropriately selected according to the specific circumstances in the forensic appraisal of drowning. Compared with diatom nitric acid digestion method, plankton 16S rDNA PCR method has practice values with such advantages as less quantity of samples, huge information and high specificity.

Acute necrotizing pancreatitis and postmortem autolysis of pancreas / 法医学杂志

OBJECTIVE@#To compare the pathomorphologic changes between the pancreas in acute necrotizing pancreatitis (ANP) and that in acute deaths of rats (within 48 hours) so as to find the distinctions.@*METHODS@#The animal models of ANP and other acute deaths (electroshock, mechanic asphyxia/strangle, and acute poisoning with tetramine) were established according to the criteria. Half-quantitative grading and image quantitative analysis methods were employed to observe the gross and microscopic changes of the pancreases.@*RESULTS@#Three features including inflammation infiltrate, fat necrosis and calcium deposit in the ANP group were considerably different from that in other acutely died rat group (P<0.05).@*CONCLUSION@#Inflammation infiltrate, fat necrosis and calcium deposit are the most important pathologic features found in ANP by common light microscope, distinguishing ANP from postmortem pancreatic autolysis.