At present, the theory and experiment teaching of forensic toxicology are faced with difficulties such as lake of practical cases and toxic types, content being abstract and difficult to un-derstand. On that account, we collected and collated many typical cases from Public Security Bureau and our school's medico legal expertise center, and then a relatively systematic and complete teaching case base in forensic toxicology has been constructed, and will be supplement constantly, so as to pro-vide extensive teaching resources and improve the teaching quality of forensic toxicology.

The people died from H5N1 avian influenza virus,which was diagnosed by serological test.The remarkable pathohistology change is as follows:thick and homogeneous things dyed red can be seen on the face of pulmonary alveoli;the alveolar septum become wider and there are a lot of inflammatory cells in the pulmonary alveoli.Above all,we think that the histology changes can provide evidence to help coroners identify people died from H5N1 avian influenza virus or not.

For the purpose of establishment of a diagnostic method of mild viral myocarditis,an experimental mild viral myocarditis model was induced in Balb/c murine by coxsackie virus B 3.The cardiac tissue secfion were stained by LSAB-immunohistochemical method with anti fibronectin(Fn) antibody. The results demonstrated that the Fn deposition was found in the myocardium of mice with myocarditis and the mild degeneration of cardiomyocytes could be identified by Fn LSAB immunohistochemical staining.It is suggested that the Fn deposition in the myocardium tissue is one of the reliable marks of myocardium inflammation.

Objective To study the characteristics of organ function and structural injuries in the elderly with multiple organ dysfunction syndrome. Method 50 Wistar rats (25 three-month-old rats and 25 twenty-month-old rats) were anaesthetized and experienced cecal ligation puncture (CLP) operation, which were defined as MODSE group and MODS group respectively. 40 Wistar rats (20 three-month-old rats and 20 twenty-month-old rats) were anaesthetized and not experienced cecal ligation puncture operation, which were used as SOGE (sham operation group in the elderly) and SOG (sham operation group). At 6 h, 12h, 24h, 48h or 72h after operation, serum levels of alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, creatinine and total bilirubin were measured by automatic biochemistry analyzer. Organs (hearts, brains, lungs, livers, kidneys) were harvested. Paraffin sections were made and stained by conventional H.E procedure for histological examination. Results Based on histological investigations, physiological and biochemical measurements, organ dysfunction in MODSE group occurred at 6h after operation and peaked at 24 h after operations. Otherwise, organ injuries with MODS occurred at 24 h and peaked at 48 h after operation. Conclusion According to histological investigations, physiological and biochemical measurements, damages of organ dysfunction and structural damages in MODSE group occurred much earlier and more seriously. which may provide an experimental evidence for medico-legal certification of the death caused by MODS.

Objective To detect the morphological evidence of identifying death from electrical injury, the ultrastructural changes of the heart, brain,lung and skin in the electrocuted rats were observed by transmission electron microscopy (TEM). Methods 12 rats were divided into the experimental and control groups. In the experimental group,6 rats were killed by electrocution, and in the control group, 6 rats were killed by decapitation. Samples from the heart, brain, lungs, and skin were fixed with valeric aldehyde and post-fixed with osmic acid. After being stained, the ultrathin sections were observed by TEM. Results Evident cell apoptosis was detected in all the tissues examined, and erythrocytes appeared swelling, which stuffed the lumen of the capillary vessels. Conclusion The ultrastructural changes of the cells of the heart, brains, lungs, and skins including the vascular endothelial cells may be used as the indicators for identifying death from electrical injury.

Objective To observe the characteristics of vertical cast-off bloodstain pattern by different hitting-tools. Methods The regular hitting tools, a kitchen knife, a dirk, a plane set-hammer and an iron pipe, were selected. At a distance of 30 cmaway fromthe wall, the hitting tool with 5 mL fresh chick-en blood made the cast-off bloodstain fromtop to bottom. Then the holistic distribution characteristics ( length , width and density ) of cast-off bloodstain and morphology characteristics ( length , width and contact angle) of first single cast-off bloodstain were analyzed. Results The distribution length of cast-off bloodstain formed by dirk was minimum( P<0 .05 ) . The distribution width of cast-off bloodstain formed by kitchen knife was minimum(P<0.05). Except the pair of kitchen knife and plane set-hammer, the distribution density between each two tools had statistical differences (P<0.05). The length of first single cast-off bloodstain formed by plane set-hammer was longest compared (P<0.05). The width of first single cast-off bloodstain had statistical differences between kitchen knife and plane set-hammer, and between dirk and plane set-hammer (P<0.05). Conclusion The type of hitting tool could be inferred by the specific characteristics of cast-off bloodstain pattern formed by every specific type of hitting tool in crime scene.

Objective To study the relationship between the DNA content of chondrocytes in the costal cartilage and postmortem interval in putrefactive rat cadavers.Methods Nuclear DNA wag visualized by modified Feulgen's staining method.DNA content of ehondrocytes in the costal cartilage was semi-quantita tively determined by a computerized image analysis system in rats within 35d postmortem.Results Staining intensity of the nuclei was gradually reduced within from 1d to 28d postmortem.The nuclej could not be detected at 35d.The DNA content of chondrocytes decreased time-dependently within 28 days after death as determined semi-quantitatively,which revealed a linear relationship between DNA content and postmortem interval.Conclusion DNA content of chondrocytes in the costal cartilage reduces time-dependently with the extension of postmortem interval.

AIM: To explore the role of activation and apoptosis of splenic lymphocytes in the development of viral myocarditis (VMC). METHODS: Apotosis and MHC II antigen of splenic lymphocytes were detected in the VMC group (VMC, death, 8 cases) and control group (non-cardiac death, 4 cases) with TUNEL and immunohistochemistry methods.RESULTS: Compared with the control group, the increased expression of MHC II antigen and apoptosis were found in the splenic lymphocytes in the VMC group. CONCLUSION: These results suggest that the abnormality of the apoptosis/activation of splenic lymphocytes may be involved in the pathogenesis of VMC.

Objective To investigate the numbers, sizes and types distribution of diatoms in drowned and postmortem immersed rabbits’ lungs. Methods Sixty-two rabbits were randomly divided into drowning group (n=30), postmortem immersion group (n=30) and land death group (n=2), and the diatoms in each lung lobe were analyzed quantitatively and qualitatively by microwave digestion and scanning electron microscopy. Results In the drowning group, the diatoms were detected in each lung lobe with Cyclotella and Melosira in the majority. In the postmortem immersion group, Cyclotella was in the majority. And the diatoms weren’t detected in some lung lobes in postmortem immersion. There were significant dif-ferences in the detection rates of upper lobe of left lung, middle lobe and cardiac lobe of right lung in two groups (P<0.05). Conclusion Based on the microwave digestion and scanning electron microscopy, the numbers, sizes and types distribution of diatoms in drowned and postmortem immersed rabbits ’ lungs can be analyzed and used as references for testing theory.

Objective To investigate the effect of maternal deprivation (MD) on neurobehavior and PP1Cγgene expression in hippocampus. Methods Male pups were randomly divided into MD group(thirty-five)and control group(twenty-four). From PND 1 to PND 21 ,pups in the MD groups underwent daily maternal deprivation for 3 h ( Postnatal day). Neurobehavior was observed to investigate neurodevelopment, Morris water maze was used to measure spatial learning and memory,and Real-Time quantitative PCR was employed to analyze PP1Cγ gene expression. Results Several significant deficiencies were observed in bodyweight and grasping reflex while a great enhancement in hot-plate test in rat pups suffering from MD( (26.23 ± 2.81 )g vs. (30. 38 ± 3.85 )g;( 19.37 ± 11.89) s vs. (22.39 ± 17.62 ) s; (4.36 ± 1.76 ) s vs. ( 5.26 ± 2.55 ) s; P ＜ 0. 05 ), but deficiencies in neurological reflexes were subtle ( ( 0.83 ±- 0.30 ) s vs. ( 0. 83 ± 0. 34 ) s; ( 3.68 ± 1.63 ) s vs. ( 5.61 ± 3. 01 ) s;( 3.00 ± 0.00 ) vs. ( 3.00 ± 0. 00); P ＞ 0. 05 ). MD had a subtle influence on spatial learning and memory (P ＞0.05). Meanwhile,MD could lead to PP1Cγ expression down-regulation on PND 22 ( (2.19 ±0.62) vs. (3.52 ±0.86), P＜0. 05)which was in line with early neurobehavior results. No difference was found compared with MD group and control group on PND60 ( ( 1.73 ± 0. 78 ) vs. ( 1.33 ± 0. 34); P ＞ 0.05 ). However, there was the up-regulation of PP1Cγexpression on PND 90 ( (2.85 ± 0. 34) vs. ( 1.34 ± 0.93 ); P ＜ 0.05 ). Conclusion MD alters early neurobehavior and hippocampal PP1Cγgene expression in the Wistar rats,but has a subtle effect on learning and memory. At the same time,MD can make PP1Cγexpression in the hippocampus varying with the age.