Purpose::The toughest challenge in pedestrian traffic accident identification lies in ascertaining injury manners. This study aimed to systematically simulate and parameterize 3 types of craniocerebral injury including impact injury, fall injury, and run-over injury, to compare the injury response outcomes of different injury manners.Methods::Based on the total human model for safety (THUMS) and its enhanced human model THUMS-hollow structures, a total of 84 simulations with 3 injury manners, different loading directions, and loading velocities were conducted. Von Mises stress, intracranial pressure, maximum principal strain, cumulative strain damage measure, shear stress, and cranial strain were employed to analyze the injury response of all areas of the brain. To examine the association between injury conditions and injury consequences, correlation analysis, principal component analysis, linear regression, and stepwise linear regression were utilized.Results::There is a significant correlation observed between each criterion of skull and brain injury ( p < 0.01 in all Pearson correlation analysis results). A 2-phase increase of cranio-cerebral stress and strain as impact speed increases. In high-speed impact (> 40 km/h), the Von Mises stress on the skull was with a high possibility exceed the threshold for skull fracture (100 MPa). When falling and making temporal and occipital contact with the ground, the opposite side of the impacted area experiences higher frequency stress concentration than contact at other conditions. Run-over injuries tend to have a more comprehensive craniocerebral injury, with greater overall deformation due to more adequate kinetic energy conduction. The mean value of maximum principal strain of brain and Von Mises stress of cranium at run-over condition are 1.39 and 403.8 MPa, while they were 1.31, 94.11 MPa and 0.64, 120.5 MPa for the impact and fall conditions, respectively. The impact velocity also plays a significant role in craniocerebral injury in impact and fall loading conditions (the p of all F-test < 0.05). A regression equation of the craniocerebral injury manners in pedestrian accidents was established. Conclusion::The study distinguished the craniocerebral injuries caused in different manners, elucidated the biomechanical mechanisms of craniocerebral injury, and provided a biomechanical foundation for the identification of craniocerebral injury in legal contexts.

Lung is the largest organ of the respiratory system. During hypoxia, pulmonary cells undergo rapid damage changes and activate the self-rescue pathways, thus leading to complex biomacromolecule modification. Death from mechanical asphyxia refers to death due to acute respiratory disorder caused by mechanical violence. Because of the absence of characteristic signs in corpse, the accurate identification of mechanical asphyxia has always been the difficulty in forensic pathology. This paper reviews the biomacromolecule changes under the pulmonary hypoxia condition and discusses the possibility of application of these changes to accurate identification of death from mechanical asphyxia, aiming to provide new ideas for related research.
Humans ; Asphyxia/pathology* ; Cause of Death ; Hypoxia/pathology* ; Lung/pathology* ; Forensic Pathology

OBJECTIVES: Fourier transform infrared spectroscopy (FTIR) was used to analyze myocardial infarction tissues at different stages of pathological change to achieve the forensic pathology diagnosis of acute and old myocardial infarction. METHODS: FTIR spectra data of early ischemic myocardium, necrotic myocardium, and myocardial fibrous tissue in the left ventricular anterior wall of the sudden death group of atherosclerotic heart disease and the myocardium of the normal control group were collected using hematoxylin-eosin (HE) and immunohistochemistry (IHC) staining as a reference, and the data were analyzed using multivariate statistical analysis. RESULTS: The mean normalized spectra of control myocardium, early ischemic myocardium and necrotic myocardium were relatively similar, but the mean second derivative spectra were significantly different. The peak intensity of secondary structure of proteins in early ischemic myocardium was significantly higher than in other types of myocardium, and the peak intensity of the α-helix in necrotic myocardium was the lowest. The peaks of amide Ⅰ and amide Ⅱ in the mean normalized spectra of myocardial fibrous tissue significantly shifted towards higher wave numbers, the peak intensities of amide Ⅱ and amide Ⅲ were higher than those of other types of myocardium, and the peak intensities at 1 338, 1 284, 1 238 and 1 204 cm^-1 in the mean second derivative spectra were significantly enhanced. Principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA) showed that FTIR could distinguish different types of myocardium. CONCLUSIONS FTIR technique has the potential to diagnose acute and old myocardial infarction, and provides a new basis for the analysis of the causes of sudden cardiac death.
Humans ; Amides ; Death, Sudden, Cardiac ; Myocardial Infarction/pathology* ; Myocardium/pathology* ; Spectroscopy, Fourier Transform Infrared/methods* ; Forensic Pathology

Objective:To observe the effect of electroacupuncture (EA) on the expressions of acetylcholine (ACh) and mucin 5AC (MUC5AC) in the lungs of rats with chronic obstructive pulmonary disease (COPD),and explore the mechanism of EA in treating COPD.Methods:Thirty Sprague-Dawley (SD) rats were randomly divided into a control group,a COPD group,and an EA group,with 10 rats in each group.The control group was a group of normal rats.The COPD rat model was induced by cigarette smoke combined with lipopolysaccharide (LPS).The COPD rats were treated with EA at bilateral Feishu (BL 13) and Zusanli (ST 36) in the EA group,30 min each time,once a day,successively for 14 d.The lung function was tested.The contents of ACh and MUC5AC in lungs and bronchoalveolar lavage fluid (BALF) were detected by enzyme-linked immunosorbent assay (ELISA).Pearson method was used to analyze the correlation between pulmonary function and the content of MUC5AC in lungs.The mRNA and protein expressions of MUC5AC in lung tissues were detected by real-time polymerase chain reaction (RT-PCR) and Western blot (WB),respectively.The immune response of MUC5AC was observed by immunohistochemistry.Results:Eight rats were left in each group,and the other two died.Compared with the control group,the total airway resistance (Raw) increased significantly and dynamic compliance (Cdyn) decreased significantly in the COPD group (P＜0.01);compared with the COPD group,the Raw level declined significantly and Cdyn increased significantly in the EA group (P＜0.01).The contents of ACh and MUC5AC in the lungs and BALF were remarkably higher in the COPD group compared with those in the control group (P＜0.01,P＜0.001);compared with the COPD group,the contents of ACh and MUC5AC were significantly lower in the EA group (P＜0.05,P＜0.001).There was a negative correlation between MUC5AC content and lung function (P＜0.001).The mRNA and protein expressions of MUC5AC in the lungs were significantly higher in the COPD group than in the control group (P＜0.001);compared with the COPD group,the expressions were significantly lower in the EA group (P＜0.01).Compared with the control group,the immune response of MUC5AC in the airway epithelium significantly increased in the COPD group (P＜0.001);the immune response of MUC5AC was significantly lower in the EA group compared with that in the COPD group (P＜0.001).Conclusion:EA treatment can improve the lung function of COPD rats,which may be related to its effect in the down-regulation of ACh and MUC5AC contents in the lungs as well as the inhibition of mucus hypersecretion.

In order to identify the Torque Teno virus (TT virus),a PCR-DHPLC assay was performed in this study.Primers specific were selected according to the characteristics of TT virus nucleic acid sequence to conduct PCR,and PCR products assayed by DHPLC.We analyzed the sensitivity,specificity,repeatability of PCR-DHPLC and applied it preliminarily on clinical detection.The specific testing was performed with TTV,HBV,HCV and HEV,no cross reaction were found,and the PCR-DHPLC assays we developed had good specification and nice repeatability.Sensitivity analysis showed that the developed PCR-DHPLC assays could detect 1.0× 101 copy/μL.Then we detected 32 serum samples by this method,real-time PCR and normal PCR at same time.The results showed that 17 TTV positives results could be observed by PCR-DHPLC for 32 samples,it is consistent with real-time PCR test results and 15 positive by normal RT-PCR.PCR-DHPLC assays showed nice specification,sensitivity,repeatability,and could be used in epidemiological investigation.

OBJECTIVETo evaluate the impact of nicotine- and tar-free cigarette smoke extract (fCSE) on the serum testosterone (T) level and erectile function of male rats.

METHODSWe randomized 30 male SD rats to three groups of equal number to receive subcutaneous injection of PBS (1.0 ml / 300 g body weight per day), fCSE (1.0 ml/300 g body weight per day), and reduced glutathione hormone (GSH, 200 mg per kg body weight per day) in addition to fCSE (fCSE + GSH), respectively, all for 8 weeks. Then we evaluated the erectile function of the rats by measuring the maximal intracavernous pressure (MICP), mean arterial pressure (MAP), ICP/MAP ratio, time of stimulation to MICP (Tmax), and cavernosal filling fate (CFR). We determined the serum T level, the activities of superoxide dismutase (SOD) , malondialdehyde (MDA), and nitric oxide synthase (NOS) in the cavernosal tissue, and also observed the morphological changes of the corpus cavernosum.

RESULTSCompared with the controls, the rats of the fCSE group showed obvious decreases in the levels of serum T ([5.37 ± 1.43] vs [3.22 ± 1.11] μg/L), NOS ([2.90 ± 0.27] vs [1.67 ± 0.18] U/mg) , and SOD ([18.41 ± 1.09] vs [13.36 ± 1.18] U/mg prot) and erectile function-related indexes MICP ([85.92 ± 6.36] vs [58.99 ± 10.76] mmHg), MICP/MAP (0.86 ± 0.09 vs [0.56 ± 0.08]), and CFR (2.14 ± 0.44 vs 0.89 ± 0.44), but markedly increased Tmax ([29.90 ± 5.78] vs [42.90 ± 8.56]s), with a positive correlation between the serum T level and CFR (r = 0. 364, P < 0.05). Masson staining revealed a lower ratio of the corpus cavernosum smooth muscle tissue to collagen fiber in the fCSE group (0.27 ± 0.04) than in the control (0.98 ± 0.12). Compared with the fCSE group, the fCSE + GSH group exhibited significantly improved MICP ([58.99 ± 10.76 ] vs [77.95 ± 7.71] mmHg), MICP/MAP (0.56 ± 0.08 vs 0.77 ± 0.09), and CFR (0.89 ± 0.44] vs 1.76 ± 0.42) and shortened Tmax ([42.90 ± 8.56 ] vs [32.10 ± 5.84 ] s). The ratio of the corpus cavernosum smooth muscle tissue to collagen fiber was higher in the fCSE + GSH than in the fCSE group (0.77 ± 0.09 vs 0.27 ± 0.04) but still lower than in the control (0.98 ± 0.12).

CONCLUSIONNicotine- and tar-free cigarette smoke extract reduces the serum T level and erectile function of rats, which is related to oxidative stress. Antioxidant therapy can improve erectile function but has a limited value for morphological protection of the penile tissue.

Animals ; Erectile Dysfunction ; chemically induced ; Male ; Malondialdehyde ; metabolism ; Muscle, Smooth ; pathology ; Nicotine ; Nitric Oxide Synthase ; metabolism ; Penile Erection ; drug effects ; Penis ; pathology ; Rats ; Rats, Sprague-Dawley ; Smoke ; adverse effects ; Superoxide Dismutase ; metabolism ; Tars ; Tobacco ; adverse effects

BACKGROUNDFor muscle invasive bladder cancer, radical cystectomy is the most effective treatment now and urinary diversion is often necessary. The use of intestinal tissue for urinary diversion is frequently associated with complications. In this study, we aimed to make a tissue-engineered conduit (TEC) using bladder epithelial cells and bladder acellular matrix (BAM) for urinary diversion in rabbits.

METHODSBladder epithelial cells of rabbit were cultivated and expanded in vitro, then seeded on BAM, and cultured for 7 days. Then cell-seeded graft was used to make TEC. In the experimental group, most of bladder of the rabbit was removed while bladder trigone was retained. The proximal end of TEC was anastomosed with bladder trigone and the distal end was anastomosed with the abdominal stoma. In the control group, TEC was made using unseeded BAM. Haematoxylin and eosin staining was conducted, respectively, at 1, 2, 4, and 8 weeks postoperatively. Immunohistochemistry was performed 8 weeks postoperatively. Intravenous urography, retrograde pyelography, and cystoscopy of TEC were made at 12 weeks postoperatively.

RESULTSAll animals were alive in the experimental group. Haematoxylin and eosin staining showed epithelial coverage in TEC. Immunohistochemistry showed anti-cytokeratin AE(1)/AE(3) antibody and anti-ZO1 antibody positive, confirming there were mature and functional epithelial cells on the lumen of TEC. Retrograde pyelography and intravenous urography showed that TEC developed well and that there was no obstruction. In the control group, four rabbits were dead within 2 weeks and scar formation, atresia, and severe hydronephrosis were found.

CONCLUSIONSWe successfully made TEC using BAM and bladder epithelial cells for urinary diversion in rabbits. The lumen of this new TEC covered mature epithelial cells and could prevent urinary extravasation.

Animals ; Epithelial Cells ; cytology ; Male ; Rabbits ; Tissue Engineering ; methods ; Urinary Bladder ; cytology ; Urinary Diversion ; methods

Humans ; Muscle, Smooth ; Reconstructive Surgical Procedures ; methods ; Surgical Flaps ; Ureter ; surgery ; Urinary Bladder

Adult ; Autopsy ; Female ; Hair ; metabolism ; Humans ; Liver ; pathology ; Thallium ; poisoning

OBJECTIVE: To investigate the changes of collagen fibers and the expression of osteopontin in the left ventricle in cases of hypertrophic cardiomyopathy (HCM), along with the significance of their potential forensic application. METHODS: Fifteen cases of HCM, 15 cases of coronary heart disease with cardiac hypertrophy and 20 cases of traffic accidents were selected as HCM group, coronary heart disease group and control group, respectively. Collagen volume fraction and osteopontin expression were observed and compared by HE staining, Masson trichrome staining and immunohistochemistry methods. Imaging and statistical methods were used for quantitative analysis. RESULTS: Collagen volume fraction in left ventricle of HCM and coronary heart disease were significantly higher than that in the control group (P < 0.05), which was not significantly different between the HCM group and the coronary heart disease group. The integral light density value of osteopontin in left ventricular cardiomyocytes of the HCM group and the coronary heart disease group were significantly higher than that of the control group (P< 0.05), and the value of the HCM group was also significantly higher than that of coronary heart disease group (P < 0.05). CONCLUSION The increased contents of collagen fibers and the overexpression of osteopontin may play an important role in myocardial fibrosis, and they can be used as markers in aid of diagnosing sudden death due to HCM.
Cardiomyopathy, Hypertrophic/physiopathology* ; Case-Control Studies ; Collagen/metabolism* ; Coronary Disease/physiopathology* ; Death, Sudden, Cardiac/etiology* ; Female ; Fibrosis ; Forensic Pathology ; Heart Ventricles/pathology* ; Humans ; Immunohistochemistry ; Male ; Myocardium/pathology* ; Osteopontin/metabolism* ; Staining and Labeling