Objective:To investigate biomechanical changes of mandible in the impact injure simulated by finite element method (FEM).Methods:Mimics and Comsol software were used to build a FEM of human craniofacial bone based on CT scan data of a normal adult.LS-DYNA and Hypermesh software were used to simulate the impact with different quality,velocity and angulation pro-duced injures of human mandible,the biomechanical parameters of the mandible in the impact injury process were analysed.Results:A FEMof human maxillofacial bone was established,and the dynamic process of different impact force produced damage was simula-ted.Mandibular chin,angle and condylar neck was the stress concentrated area in the process of mandible injury.There was higher stress peak at the site which was closer to the impact position,the stress peak arrival time was also earlier.When the impactor with the same quality,the bigger the velocity,the greater the stress peak.When the impactor with the same velocity,the bigger the quali-ty,the greater the stress peak.When the impactor with the same velocity and quality,there was greater stress peak under the impact to mandible from angulation of 0 degree.Stress transfered to the surrounding bone from the impact position radially and gradually re-duced.The bone area with small cross-section was prone to high stress and more serious damage.Conclusion:The quality,the ve-locity,the impact angle and the impact site are the factors affecting the severity of impact injury.

Animals ; Animals, Newborn ; Brain ; metabolism ; pathology ; Caspase 3 ; Caspases ; metabolism ; DNA-Binding Proteins ; genetics ; Gene Expression ; Hypoxia, Brain ; genetics ; physiopathology ; Hypoxia-Inducible Factor 1 ; Hypoxia-Inducible Factor 1, alpha Subunit ; Immunohistochemistry ; Ischemic Preconditioning ; Nuclear Proteins ; genetics ; RNA ; genetics ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction ; Transcription Factors

Objective To develop a 3D finite element model for the human craniomaxillofacial region in an attempt to offer basis to the research of simulation of craniomaxillofacial injury.Methods A healthy adult male was submitted to head CT scan, and the data was imported into the Mimics 15.0 software for threshold segmentation and 3D reconstruction according to the classifications of bone tissue, skin tissue and subcutaneous tissue.The reconstruction data was imported into 3D reverse software Geomagic Studio 2012, and the images were optimized and the 3D model was generated.The three parts of the model were fitted according to the actual proportion using the 3D control software Solidworks 14.0, and then the boundary conditions were derived.Hypermesh 12.0 finite element processing software was used to build the volume mesh, and the model was established.Each layer of the model was given to the material parameters, and the simulation conditions were provided to test the model.Results This model was completely composed of volume meshes, including 214,250 hexahedral meshes and 411,920 nodes.This model can clearly show the stress distribution, the trend of fracture line, the displacement of fracture block of soft and hard tissue during the simulation, and the results are consistent with clinical practice.Conclusion A three-dimentional finite element model with good performance is established, which can be used for biomechamics simulation analysis of multiple sites on the head or the whole structure, and has a certain significance in clinical and scientific research.

Objective: The study investigated cognitive performance and brain function between treatment-resistant depression (TRD) and non- TRD patients to find potential neurobiological markers associated with refractoriness in depression patients. Methods: Fourteen TRD patients, 26 non-TRD patients and 23 healthy controls (HC) were included in the present study. The neural function of prefrontal cortex (PFC) and cognitive performance among the three group were examined using near-infrared spectroscopy (NIRS) during verbal fluency task (VFT). Results: Both TRD and non-TRD groups exhibited significantly worse VFT performance and lower activation of oxygenated hemoglobin (oxy-Hb) changes in the bilateral dorsolateral PFC (DLPFC) compared to the HC group. Within the TRD and non-TRD groups, VFT performance was no significant difference, but activation of oxy-Hb changes in dorsomedial PFC (DMPFC) in TRD patients was significantly lower than non-TRD patients. In addition, activation of oxy-Hb changes in right DLPFC were negatively correlated with the severity of depressive symptoms in depression patients. Conclusion Both TRD patients and non-TRD patients exhibited lower oxy-Hb activation in DLPFC. TRD patients exhibit lower oxy- Hb activation in DMPFC than non-TRD patients. fNIRS maybe a useful tool for predict depressive patients with or without treatment resistant.

Atrioventricular Block ; etiology ; Cardiac Catheterization ; adverse effects ; Heart Septal Defects, Ventricular ; therapy ; Hematologic Diseases ; etiology ; Hemolysis ; Humans

OBJECTIVESTo assess the diagnostic accuracy and to study the histologic typing of mediastinal lesions using core needle biopsies.

METHODSThe histopathology and immunophenotype of 65 mediastinal core needle biopsy specimens were studied retrospectively by light microscopy and immunohistochemical staining (ABC method). Gene rearrangement studies were performed in some of the non-Hodgkin's lymphomas cases using PCR. Follow-up records were also analyzed.

RESULTSMorphologically, all specimens showed a combination of epithelioid cells, lymphoid cells and fibrous tissue in different proportions. The pathologic diagnoses included lymphoma (21 cases), pulmonary carcinoma (20 cases), thymoma (14 cases), thymic carcinoma (4 cases), seminoma (3 cases) and chronic inflammation (1 case). Definitive diagnosis was not possible in 2 cases due to insufficient material. The tumor cells in lymphoma (21 cases) expressed CD20, CD3, TDT, CD30, CD15 or EMA, depending on their histologic subtypes. Tumor cells in the 17 pulmonary carcinoma cases expressed cytokeratin (CK), except 3 cases of small cell carcinoma of lung. Synaptophysin, chromogranin A and neuron-specific enolase were all positive in the 10 cases of small cell carcinoma of lung and 1 case of thymic small cell carcinoma (which was also CD5 negative). The 3 cases of adenocarcinoma of lung showed positivity for thyroid transcription factor-1 (TTF-1) and they were negative for CD5. The 14 thymoma cases expressed CK, CD3 or CD20. The 3 thymic carcinoma cases expressed CK and CD5. Placental-like alkaline phosphatase (PLAP) was positive in 3 seminoma cases which were CK-negative. Immunoglobulin heavy chain gene was rearranged in the 3 cases of diffuse large B-cell lymphoma and 1 B-cell anaplastic large cell lymphoma case. T-cell receptor beta gene was rearranged in 5 T-cell lymphoblastic lymphoma cases.

CONCLUSIONSMicroscopic assessment of tissue samples from mediastinal core needle biopsies should be made in combination with clinical and radiologic information. Ancillary investigations, including immunohistochemical staining and/or gene rearrangement studie, are needed in both non-lymphoma and lymphoma cases of mediastinum.

Adolescent ; Adult ; Aged ; Biopsy, Needle ; CD5 Antigens ; analysis ; Child ; Child, Preschool ; Diagnosis, Differential ; Female ; Follow-Up Studies ; Gene Rearrangement, beta-Chain T-Cell Antigen Receptor ; Humans ; Keratins ; analysis ; Lung Neoplasms ; chemistry ; pathology ; Lymphoma ; chemistry ; pathology ; Male ; Mediastinal Diseases ; pathology ; Mediastinum ; pathology ; Middle Aged ; Retrospective Studies ; Thymus Neoplasms ; chemistry ; pathology

A 76-year-old male presented with a recurrent depressive episode, an unsteady gait and cognitive impairment. Extensive blood tests, including hemogram, biochemical tests, folic acid, vitamin B12, and thyroid hormone, showed normal results. With the exception of the unsteady gait, neurological examination was negative. Brian magnetic resonance imaging (MRI) showed the typical feature of central pontine myelinolysis (CPM); however, there was no history of alcoholism, liver transplantation, malnutrition or rapid correction of hyponatremia. The patient had taken venlafaxine to treat major depressive disorder for more than 20 years. After discontinuation of venlafaxine, the unsteady gait gradually resolved, and subsequent MRI revealed reduction of the lesions over 6 months. We discuss herein the possible correlation between chronic use of venlafaxine and CPM.

Objective To analyze the clinical characteristics,muscle pathological features and pathogenic gene mutation in 4 cases with LMNA-related congenital muscular dystrophy (L-CMD).Methods Clinical data of the probands and the parents were collected.Skeletal muscle specimens were biopsied from the probands for pathological analysis.Genomic DNA and RNA were extracted from peripheral blood leukocytes,and PCR,reverse transcription(RT)-PCR and DNA direct sequencing were employed to analyze the LMNA gene to determine the gene mutation and confirm the pathogenicity.Results Four patients had symptoms from fetal period to several months after birth.They presented with motor retardation,muscle weakness with prominent the proximal upper limbs,distal lower limbs and neck extensor,hypotonia,contractures,with mild to moderate elevation of CK level.The muscle biopsies showed muscular dystrophic and with inflammatory changes,and the abnormal nuclear morphology was observed with transmission electron microscopy.Genetic analysis of them detected 4 dominant de novo mutations.Three of them had unreported pathogenic mutations.The same sites of the LMNA gene were wild type in their parents.Conclusions Four cases of L-CMD are genetically identified.Genetic counseling of the family can be possible.The patients should be considered LMNA gene mutation of they present themselves with muscle weakness with the proximal upper limbs,distal lower limbs and neck extensor,hypotonia,contractures,mild to moderate elevation of CK level,and if the biopsies show muscular dystrophic changes but also with inflammatory changes should be considered LMNA gene mutation.Genetic analysis is the most reliable method for diagnosing L-CMD.

A 76-year-old male presented with a recurrent depressive episode, an unsteady gait and cognitive impairment. Extensive blood tests, including hemogram, biochemical tests, folic acid, vitamin B12, and thyroid hormone, showed normal results. With the exception of the unsteady gait, neurological examination was negative. Brian magnetic resonance imaging (MRI) showed the typical feature of central pontine myelinolysis (CPM); however, there was no history of alcoholism, liver transplantation, malnutrition or rapid correction of hyponatremia. The patient had taken venlafaxine to treat major depressive disorder for more than 20 years. After discontinuation of venlafaxine, the unsteady gait gradually resolved, and subsequent MRI revealed reduction of the lesions over 6 months. We discuss herein the possible correlation between chronic use of venlafaxine and CPM.

Objective To explore a reliable, simple and minimally invasive approach for establishing rat models of intraventricular hemorrhage (IVH). Methods The rat model of IVH was established by stereotactic injection of autologous arterial blood into the right lateral ventricle. The neurobehavioral scores of the rats were recorded at different time points after the injection, and the pathological changes in the ventricular and periventricular brain tissues were observed. Results IVH was successfully induced in 88.9% of the rats, which exhibited significant behavioral changes 6 h after IVH. The behavioral abnormalities were ameliorated 7 days after intraventricular injection of the blood. Optical microscopy showed ruptured continuity of the ependymal lining of the lateral ventricle, enlargement of the intercellular space, periventricular edema and neuronal necrosis in periependymal tissues 24 h after IVH. Conclusion The approach we adopted allows convenient establishment of a stable IVH model in rats with minimal invasiveness and pathological changes closely resembling those in patients with IVH.