Parametric analysis of craniocerebral injury mechanism in pedestrian traffic accidents based on finite element methods.

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 was 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.

Research Progress on Molecular Changes in Pulmonary Hypoxia and Cause of Death Identification in Mechanical Asphyxia.

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.

Forensic Pathological Diagnosis of Acute and Old Myocardial Infarction Using Fourier Transform Infrared Spectroscopy.

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.

Loss of LKB1 Expression Decreases the Survival and Promotes Laryngeal Cancer Metastasis.

Background: Given recent results indicating that diminished LKB1 expression in laryngeal cancer correlates with shorter survival. We aim to perform an analysis estimate the role of decreased liver kinase B1(LKB1) and in the prognostication of human laryngeal squamous cell carcinoma (LSCC). Methods: We conducted a retrospective study and evaluate the expression of LKB1 and p16INK4a (p16) in 208 clinical advanced-stage LSCC tissue samples by using immunohistochemistry. The specimens were received at Sun Yat-sen University Cancer Center (Guangzhou, China). To evaluate the independent prognostic relevance of LKB1, univariate and multivariate Cox regression models were used, overall survival (OS) and distant metastasis-free survival (DMFS) were compared using the Kaplan-Meier method. Results: Immunohistochemical analyses revealed that 80/208 (38.5%) of the LSCC tissue samples expressed high LKB1. Low LKB1 expression was associated with a significantly shorter OS and DMFS than high LKB1 expression (P = 0.041 and 0.028, respectively; log-rank test), and there was a poorer OS in the p16-positive than p16-negative group. In the subgroup stratified by p16 status, the shorter OS were also seen with low LKB1 expression. Multivariate survival analysis indicated that high LKB1 expression was an independent prognostic factor for OS (hazard ratio [HR]: 1.628, 95% confidence interval [CI]: 1.060-2.500, P = 0.026) and DMFS (HR: 2.182, 95% CI: 1.069-4.456, P = 0.032). Conclusions: Our data indicated that low expression of LKB1 was significantly associated with poor prognosis and it may represent a marker of tumor metastasis in patients with LSCC. When combined with p16, LKB1 was also of prognostic value.

Association between the CYP2E1 polymorphisms and lung cancer risk: a meta-analysis.

The previous, published data on the association between CYP2E1 RsaI (rs2031920), DraI (rs6413432) polymorphisms and lung cancer risk remained controversial. Hence, we performed a meta-analysis to investigate the association between lung cancer and CYP2E1 RsaI (5,074 cases and 6,828 controls from 34 studies), and CYP2E1 DraI (2,093 cases and 2,508 controls from 16 studies) in different inheritance models. Overall, significantly decreased lung cancer risk was observed (dominant model: odds ratio (OR) 0.80, 95 % confidence interval (95 % CI) 0.71-0.90; heterozygote model: OR 0.80, 95 % CI 0.70-0.90; additive model: OR 0.82, 95 % CI 0.72-0.94) when all the eligible studies were pooled into the meta-analysis of CYP2E1 RsaI polymorphism. In further stratified and sensitivity analyses, significantly decreased lung cancer risk was found among Asians (dominant model: OR 0.81, 95 % CI 0.71-0.93; heterozygous model: OR 0.81, 95 % CI 0.69-0.95), population-based studies (dominant model: OR 0.69, 95 % CI 0.54-0.88; recessive model: OR 0.39, 95 % CI 0.16-0.91; additive model: OR 0.67, 95 % CI 0.53-0.84; homozygous model: OR 0.34, 95 % CI 0.14-0.80; heterozygous model: OR 0.70, 95 % CI 0.54-0.91), hospital-based studies (dominant model: OR 0.80, 95 % CI 0.69-0.93; additive model: OR 0.84, 95 % CI 0.70-1.00; heterozygous model: OR 0.80, 95 % CI 0.68-0.95), lung AC (heterozygous model: OR 0.84, 95 % CI 0.71-1.00), smokers (dominant model: OR 0.72, 95 % CI 0.55-0.94), and non-smokers (dominant model: OR 0.74, 95 % CI 0.61-0.91). There was no significant association between CYP2E1 DraI polymorphism and the risk of lung cancer when all the eligible studies were pooled into the meta-analysis. However, in further stratified and sensitivity analyses, significant association was observed among smokers (dominant model: OR 0.49, 95 % CI 0.35-0.69). In summary, this meta-analysis indicates that CYP2E1 RsaI polymorphism is associated with lung cancer risk among Asians, CYP2E1 RsaI polymorphism may be associated with lung adenocarcinoma risk, and CYP2E1 RsaI and DraI polymorphisms may be associated with decreased lung cancer risk in smokers.

Association between the TP53 polymorphisms and lung cancer risk: a meta-analysis.

The previous published data on the association between TP53 codon 72, intron 6, and intron 3 16 bp polymorphisms and lung cancer risk remained controversial. This meta-analysis of literatures was performed to derive a more precise estimation of the relationship. 38 publications with 51 studies were selected for this meta-analysis, including 17,337 cases and 16,127 controls for TP53 codon 72 (from 43 studies), 2,201 cases and 2,399 controls for TP53 intron 6 (from four studies), and 4,322 cases and 4,558 controls for TP53 intron 3 16 bp (from four studies). When all the eligible studies were pooled into the meta-analysis of codon 72 polymorphism, there was significant association between lung cancer risk and codon 72 polymorphism in any genetic model (dominant model: OR = 1.13, 95 % CI 1.05-1.21; recessive model: OR = 1.14, 95 % CI 1.02-1.27; additive model: OR = 1.19, 95 % CI 1.05-1.33). In the subgroup analysis by ethnicity, histological type, source of control, and smoking status, significantly increased risks were observed in subgroups such as Asians, Caucasians, lung squamous cell carcinoma patients for Asians, population-based study, hospital-based study, non-smokers, and smokers. When all the eligible studies were pooled into the meta-analysis of intron 6 polymorphism, there was significant association between lung cancer risk and intron 6 polymorphism in dominant model (OR = 1.27, 95 % CI 1.11-1.44). When all the eligible studies were pooled into the meta-analysis of intron 3 16 bp polymorphism, there was significant association between lung cancer risk and intron 3 16 bp polymorphism in dominant model (OR = 1.12, 95 % CI 1.02-1.23) and additive model (OR = 1.41, 95 % CI 1.04-1.90). Additionally, when one study was deleted in the sensitive analysis, the results of TP53 intron 3 16 bp duplication polymorphism were changed in the dominant model (OR = 1.11, 95 % CI 0.87-1.42) and additive model (OR = 1.01, 95 % CI 0.65-1.56). In summary, this meta-analysis indicates that codon 72 and intron 6 polymorphisms show an increased lung cancer risk. A study with the larger sample size is needed to further evaluated gene-environment interaction on TP53 codon 72, intron 6, and intron 3 16 bp polymorphisms and lung cancer risk.

Effect of antisense oligodeoxynucleotides glucose transporter-1 on enhancement of radiosensitivity of laryngeal carcinoma.

PURPOSE: Laryngeal carcinomas always resist to radiotherapy. Hypoxia is an important factor in radioresistance of laryngeal carcinoma. Glucose transporter-1 (GLUT-1) is considered to be a possible intrinsic marker of hypoxia in malignant tumors. We speculated that the inhibition of GLUT-1 expression might improve the radiosensitivity of laryngeal carcinoma. METHODS: We assessed the effect of GLUT-1 expression on radioresistance of laryngeal carcinoma and the effect of GLUT-1 expressions by antisense oligodeoxynucleotides (AS-ODNs) on the radiosensitivity of laryngeal carcinoma in vitro and in vivo. RESULTS: After transfection of GLUT-1 AS-ODNs: MTS assay showed the survival rates of radiation groups were reduced with the prolongation of culture time (p<0.05); Cell survival rates were significantly reduced along with the increasing of radiation dose (p<0.05). There was significant difference in the expression of GLUT-1mRNA and protein in the same X-ray dose between before and after X-ray radiation (p<0.05). In vivo, the expressions of GLUT-1 mRNA and protein after 8Gy radiation plus transfection of GLUT-1 AS-ODNs were significant decreased compared to 8Gy radiation alone (p<0.001). CONCLUSION: Radioresistance of laryngeal carcinoma may be associated with increased expression of GLUT-1 mRNA and protein. GLUT-1 AS-ODNs may enhance the radiosensitivity of laryngeal carcinoma mainly by inhibiting the expression of GLUT-1.

[Changes of left ventricular myocardial collagen fibers and osteopontin expression in hypertrophic cardiomyopathy].

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.

Hemorrhage of brain metastasis from non-small cell lung cancer post gefitinib therapy: two case reports and review of the literature.

BACKGROUND: Gefitinib is one of the small molecule inhibitors of epidermal growth factor receptor tyrosine kinase (EGFR TKIs). Clinical trials have demonstrated it is effective for treatment of a subset of patients with advanced non-small cell lung cancer (NSCLC). Gefitinib has been generally considered to be a relatively safe agent. Besides a small proportion of fatal interstitial pneumonia, the common adverse drug reactions of gefitinib include diarrhea and skin rash, which are generally mild and reversible. Herein, we report the first two cases of brain metastasis hemorrhage that might be involved with the use of gefitinib. CASE PRESENTATION: Two patients with brain metastasis from NSCLC developed brain hemorrhage after gefitinib therapy. The hemorrhage in one case occurred one month after gefitinib combined with whole brain radiation therapy (WBRT), and in the another case hemorrhage developed slowly within brain metastases eight months post gefitinib monotherapy for diffuse pulmonary metastasis from a lung cancer undergone surgical removal previously. CONCLUSION: We speculate brain hemorrhage could be one of the adverse drug reactions of gefitinib treatment for NSCLC and suggest clinicians be aware of this possible rare entity. More data are needed to confirm our findings, especially when gefitinib is used in the settings of brain metastases from NSCLC or other origins.

Re-evaluation of 6th edition of AJCC staging system for nasopharyngeal carcinoma and proposed improvement based on magnetic resonance imaging.

PURPOSE: To use magnetic resonance imaging to re-evaluate and improve the 6th edition of the International Union Against Cancer/American Joint Committee on Cancer staging system for nasopharyngeal carcinoma. METHODS AND MATERIALS: We performed a retrospective review of the data from 924 biopsy-proven nonmetastatic nasopharyngeal carcinoma cases. All patients had undergone magnetic resonance imaging examinations and received radiotherapy as their primary treatment. RESULTS: The T classification, N classification, and stage group were independent predictors. No significant differences in the local failure hazards between adjacent T categories were observed between Stage T2b and T1, Stage T2b and T2a, and Stage T2b and T3. Although the disease failure hazards for Stage T1 were similar to those for Stage T2a, those for Stage T2b were similar to those for Stage T3. Survival curves of the different T/N subsets showed a better segregation when Stage T2a was downstaged to T1, T2b and T3 were incorporated into T2, and the nodal greatest dimension was rejected. The disease failure hazard for T3N0-N1 subsets were similar to those of the T1-T2N1 subsets belonging to Stage II; the same result was found for the T4N0-N2 subsets in the sixth American Joint Committee on Cancer staging system. However, the staging system we propose shows more consistent hazards within the same stage group and better survival discrimination among T categories, N categories, and overall stages. CONCLUSION: Using the 6th American Joint Committee on Cancer staging system produces an acceptable distribution of patient numbers and segregation of survival curves among the different stage groups. The prognostic accuracy of the staging system could be improved by recategorizing the T, N, and group stage criteria.

How does magnetic resonance imaging influence staging according to AJCC staging system for nasopharyngeal carcinoma compared with computed tomography?

PURPOSE: To analyze the degree and pattern of influence of magnetic resonance imaging (MRI) on staging according to the 6th edition of the American Joint Committee on Cancer staging system compared with computed tomography (CT). METHODS AND MATERIALS: The MRI and CT scans and medical records of 420 consecutive patients with newly diagnosed nasopharyngeal carcinoma (NPC) were analyzed retrospectively. The tumors of all patients were staged according to the 6th edition of the American Joint Committee on Cancer staging system. RESULTS: A significant difference (p <0.05) was found between CT and MRI in demonstrating involvement in the oropharynx (CT, 25.0% vs. MRI, 14.5%), prevertebral muscle (CT, 18.4% vs. MRI, 36.0%), parapharyngeal space (CT, 82.6% vs. MRI, 68.8%), skull base (CT, 31.0% vs. MRI, 52.6%), sphenoid sinus (CT, 13.6% vs. MRI, 16.7%), ethmoid sinus (CT, 7.1% vs. MRI, 3.3%), intracranial area (CT, 4.8% vs. MRI, 16.0%), and retropharyngeal lymph nodes (CT, 52.1% vs. MRI, 69.0%). The incidence of cervical lymph node metastasis and lymph node metastasis at each level was similar according to CT and MRI. MRI resulted in changes in 49.8% of T stage cases, 10.7% of N stage cases, and 38.6% of clinical stage cases. CONCLUSION: MRI demonstrated early primary tumor involvement more precisely and deep primary tumor infiltration more easily. The use of MRI caused dramatic changes in the results of the T stage and clinical staging and should be preferred to CT in staging NPC. Patients would benefit from changes in treatment strategies resulting from the use of MRI.

[The role of diaphgram fatigue in the death from hanging with bound upper limbs of rabbits].

OBJECTIVE: To explore the role of diaphgram fatigue in the death from hanging with bound upper limbs of rabbits. METHODS: Rabbits were hanged with upper limbs bound, then the data of EMGdi were gathered RESULTS: By analyzing power spectral of EMGdi in experiment, we compare the ratio change of H/L between pre-experiment and post-experiment. There is a significance decrease of the ratio of H/L, so it indicates that diaphgram fatigue does exist. CONCLUSION: Diaphgram fatigue plays an important role in the death from hanging with limbs of rabbits bound.