The Expression Of Diatom In Organ Of The Postmortem Into The Water

Background&ObjectiveIdentification of water bodies is a common and important part of the work of forensic pathology. The major problem to solve is identification of water bodies death cause, namely drowning during his lifetime, or postmortem into the water. Drowning (Drowning) is due to the liquid enters and blocks the airway and alveolar space, hindering gas exchange leading to hypoxia and hypercapnia, asphyxia death are known as drowning. The actual case, the majority of the bodies found in water are drowning by accidents, drowning is also one of the common means of suicide, a minority belong to homicide, and even the postmortem into the water, so it is very important for the water body to clear nature and idetection in such cases.Diatoms (diatom), also known as diatoms, mostly planktonic in waters to survive are single-celled organisms, a small number of diatom are.groups or filaments. In normal circumstances, if the body was alive when drowning, diatoms will with the drowning liquid into the respiratory tract and lung tissue, and through a cycle to the internal organs of the body. So the lifetime may be checking the diatoms in whether the lung and other organ to determine of drowning. Moreover, if the form of the (species, size, diameter) these diatoms and water diatom samples are consistent, can be considered the deceased was alive drowned in the waters of the samples. Who died after postmortem into the water, which generally do not exist in the lung tissue of diatoms, it is impossible in their lungs, liver, kidney, bone marrow, while the detection of diatoms. Therefore, in forensic practice, diatom test is the most commonly used methods to diagnosis of drowning, especially the identification of the cause of death in water-corruption bodies, is regarded as the best identification method.In1960s,there have reported diatoms may also enter the lungs of the postmortem into the water. In recent years, scholars from both here and abroad have reported diatoms may also enter the lungs of the postmortem into the water.If the water location of the body that is deeper, also means pressure is large, or for a long time, the phenomenon of corruption can be found, diatoms may also enter the lungs and was detected. But this academic point of view not seen experimental basis.Methods1.65healthy female SD rats were randomly divided into40postmortem into the water group and20drowning group and5blank control group, there was5rats in every group. The postmortem into the water group rats were killed by air embolism then into the water, this group set depth of5m,10m,15m and20m, at different depths then divided time into the water48h and120h. Drowning group divided according to depth of5m,10m,15m and20m groups, in the water for2hours. Using self-made improvement deepwater collector extraction Om,5m,10m,15m,20m depth of water.2. The Lung and liver and kidneys diatom was detected with enzyme chemical method and nitric acid digestion method. Water diatom was detected with nitric acid digestion method.3. All the experimental data can be expressed by mean±tandard deviation (x±s). Using Image-Pro Plus5.0image analysis system to measure diatom. Comparison between groups use single factor analysis of variance, within group comparisons used LsD-t, inspection level a=0.05.4.112cases of forensic investigation about corpses recovered out of water were selected from part of the Public Security Bureau of Henan Province from2011to2013. The cases were classified according to different standards in order to obtain their general eatures by use of Excel software.Results1. The diatom test of rat lung、liver、kidneys results:in the postmortem into the water group,5m,10m,15m,20m, into the water while the48h and120h were not detected at diatom. The lung of the drowning group in5m,10m,15m,20m can be detected at diatom, the liver and kidneys were not detected at diatom. The blank control grouprat lungs were not detected at diatom.2. Drowning rats lung pathology changes:The membranes of the lungs is smooth, full of lobi pulmonis, most lung section were gray white, extrusion visible foam overflow. Under a mocroscopr:the majority of alveolus pulmonis are enlargement, pulmonary interstitial hemorrhage, alveolar wall thinning or even fracture, ipart of alveolar can visible red liquid. The forensic pathological diagnosis: saqueous emphtsema.3. The diatom test results of water sample:the most total diatom in the surface water, diatoms of depth of5m reduced in number, the number of the Pennales in10m water depth at low value, total number of diatom in15m water depth indiatom at low value, the number of the Centricae in depth of20m at low value. Comparison of the numbenr of diatom in different depth, we can see the differences were statistically significant (P<0.01).As the water depth increases, the total number of diatom are different,the species of diatoms also changed. The diatoms of different points from same surface and bottom water samples were compared with P<0.01, the differences were no statistical significance.4. Statistics suggested that forensic identifications about corpses in water a total of112cases, including65cases of male,47cases of female. There have99cases of corruption of organs and tissues. Pathological examination of48cases, saqueous emphtsema, splenic anemia, congestion of liver detection rates were62.7%,42.5%,45.5%, Splenic anemia and congestion of liver often occur at the same time.100cases identified as drowning by diatom test,57cases of the natures of deaths were undefined, the diatom test results were negative ot10cases of postmortem into the water.Conclusions1. The postmortem of dult SD rats in mechanical asphyxia death into deepwater (20m) stay to corruptionoccurs (120h), diatom test results of Lung edge and hilum of lung are negative.2.We successfully improvement deepwater collector extracted from the specified depth of water, This model could be used for extract water. Comparison of different water quantity diatom group, the difference was have statistical significant (P<0.01). As the water depth increases, the total number of diatom are different, the species of diatoms also changed. The differences of the diatoms of different points from same surface and bottom water samples were no statistical significance.3. The diatom of water is not easy to enter the pulmonary tissue of the postmortem into the water. The diatom test of lung tissue have a great significance of determine whether the drowning...