OBJECTIVETo investigate the pathogenicity of Leptospira interrogans fliR gene to J774A.1 cells.

METHODSfliR gene from L. interrogans serogroup Icterohaemorrhagiae serovar lai strain 56601 and kana gene from plasmid pET42a were amplified by PCR. Suicide plasmid of fliR gene was constructed; and specific siRNA for fliR gene was designed and synthesized. fliR gene mutants were constructed by gene knock-out with suicide plasmid (56601fliR-Kana) and gene silencing with siRNA (56601siRNA-R2). The mutants were identified by PCR, sequencing and semi-quantitative RT-PCR. Adhesion to mouse mononuclear-macrophage J774A.1 and induction of cell necrosis and apoptosis by 56601fliR-Kana and 56601siRNA-R2 were examined by adhesion test and flow cytometry, respectively.

RESULTThe nucleotide and putative amino acid sequences of cloned fliR gene had 99.9% and 100% similarities to those of reported sequences in GenBank. The nucleotide sequence of the cloned kana gene was identical to the corresponding sequence in pET42a map. The results of PCR and sequencing confirmed that kana gene was inserted in the sequence of 56601fliR-Kana fliR gene. The mRNA level of fliR gene in 56601fliR-Kana was remarkably decreased (P<0.01) while the mRNA level of fliR gene in 56601siRNA-R2 was much lower than that in wild strain 56601 (P<0.05). 56601fliR-Kana and 56601siRNA-R2 lost the ability to adhere J774A.1 cells; and their ability to induce cell necrosis and apoptosis was markedly weakened (P<0.01).

CONCLUSIONfliR is a virulence-associated gene of L. interrogans and the function of the gene is closely related to adhesion, induction of cell necrosis and apoptosis of the microbe.

Animals ; Apoptosis ; Bacterial Adhesion ; Bacterial Proteins ; genetics ; metabolism ; Cell Line ; Leptospira interrogans ; genetics ; pathogenicity ; Macrophages ; microbiology ; pathology ; Membrane Proteins ; genetics ; metabolism ; Mice ; RNA, Messenger ; genetics ; metabolism ; RNA, Small Interfering ; genetics

OBJECTIVETo study the content variation of triptolide in medicinal material of Tripterygium and provide theoretical basis for the hereditary improvement, the gathering and process, the quality evaluation and the provenance division in medicinal material of Tripterygium.

METHODHPLC method was used to determine the content of triptolide.

RESULTThe relations between triptolide and germplasm, growth year, gathering season were found out basically.

CONCLUSIONThe triptolide contents in xylem are affected by hereditary factors remarkably. While the triptolide contents in phloem are not affected obviously. The accumulation of triptolide needs the certain growth years. However when growth is beyond certain years, the triptolide content decreases with the disintegration of secondary metabolism in xylem. The triptolide in xylem is highest in winter and decreasing in growing season. The triptolide in phloem is less affected by the season.

Chromatography, High Pressure Liquid ; Diterpenes ; analysis ; metabolism ; Ecosystem ; Epoxy Compounds ; analysis ; metabolism ; Phenanthrenes ; analysis ; metabolism ; Plant Roots ; anatomy & histology ; chemistry ; Plants, Medicinal ; anatomy & histology ; chemistry ; growth & development ; Seasons ; Species Specificity ; Time Factors ; Tripterygium ; anatomy & histology ; chemistry ; growth & development ; Xylem ; chemistry

INTRODUCTIONBased on the estimate results of the capacity and preparedness of Beijing hospitals to respond to pandemic influenza, using flu surge model to evaluate its applicable hypothesis and to provide government with sentient strategy in planning pandemic influenza. Through collection of medical resources information, we calculated the possible impaction on hospitals by Flu Surge model and explored the applicable hypothesis in model operation through a questionnaire, direct observation and group discussion in 3 hospitals in Beijing. Based on flu surge model estimation during a 6-week epidemic from a pandemic virus with 35% attack rate, Beijing would have had an estimation of 5 383 000 influenza illnesses, 2 691 500 influenza outpatients, 76 450 influenza hospitalizations and 14 508 excess deaths. For a 6-week period with 35% attack rate, there would be a peak demand for 8% of beds, 210% of ICU beds, and 128% of ventilators estimated. Outpatients in different level hospital were quite disproportionated with 1742/ hospital/day, 650/hospital/day, and 139/hospital/day respectively. The sampled health workers had a mastery of 63.4% of the total knowledge and skills of diagnosing and treating of influenza, 73.5% of them washed their hands and 63.5% used PPE correctly. The total beds capacity, medical beds capacity and respiratory medical beds capacity would increase 8%, 35% and 128% respectively.

CONCLUSIONThe estimation results could be referenced when planning the pandemic strategy, but the results should be treated objectively when considering the hypothesis and practical situation in this model being used.

Adolescent ; Adult ; Aged ; Child ; Child, Preschool ; Disease Outbreaks ; statistics & numerical data ; Female ; Hospital Bed Capacity ; Hospital Planning ; Hospitalization ; statistics & numerical data ; Humans ; Infant ; Infant, Newborn ; Influenza, Human ; epidemiology ; Male ; Middle Aged ; Models, Statistical ; Surge Capacity ; Young Adult

Objective To develop the finite element model of six-year-old child occupant lower extremity with higher biofidelity and validate the model of knee joints,as well as analyze the biomechanical responses of growth plate under frontal impact load and injury mechanisms of the knee joint by using this model.Methods The sixyear-old child occupant lower extremity with growth plate was modeled based on children's anatomy and CT images,and corresponding material properties of the lower extremity model were assigned.The model was validated according to biomechanical experiments by Kerrigan et aL and Haut et aL and then was used to analyze the injury results of growth plate with different material properties.Results The model validation was qualified by comparing the curves from the experimental and simulation results.The growth plates at knee regions could change injury patterns of the child occupant lower extremity fracture.The material properties of growth plate could affect threshold of axial damage of the femur as well as relative position of the fracture.Conclusions The validated model can be used for related study and application on biomechanical responses and injury mechanisms of sixyear-old child occupant lower extremities.

OBJECTIVETo sum up the various procedures for skeleton and soft tissue contour reconstruction in severe progressive hemifacial atrophy.

METHODSFrom Jan 2004 to May 2012, 25 patients with severe progressive hemifacial atrophy underwent the procedures of lipoinjection, microsurgical flap transplantation, dermis grafting, distraction osteogenesis, orthognathic surgery and so on for both skeleton and soft tissue reconstruction.

RESULTSAmong them, zygomatic augmentation and lipoinjection were performed in 24 cases, anterolateral thigh adipofascial flap in 10 cases and latissimus dorsi flap in one case, orthognathic surgery in 17 cases, including Le Fort I osetoectomy in 3 cases, genioplasty in 4 cases, mandibular distraction osteogenesis combined with secondary Le Fort I osteotomy in 3 cases, genioplasty combined with mandibular augmentation with Medpor implant in 7 cases. The patients were followed up for 6 months to 5 years. Through skelton and soft tissue reconstruction, the oblique occlusion plane and malocclusion were corrected with great improvement in face asymmetry.

CONCLUSIONSFor severe progreassive hemifacial atrophy, comprehensive procedures should be adopted for both skelton and soft tissue reconstruction to achieve good results.

Adipose Tissue ; transplantation ; Facial Asymmetry ; surgery ; Facial Hemiatrophy ; surgery ; Humans ; Mandible ; surgery ; Orthognathic Surgical Procedures ; Osteogenesis, Distraction ; methods ; Osteotomy, Le Fort ; methods ; Reconstructive Surgical Procedures ; methods ; Skin Transplantation ; methods ; Surgical Flaps ; transplantation

Objective To explore the brain injury mechanism and enrich the database of human finite element (FE) biomechanical model by developing the FE model of one-year-old toddler head. Methods Based on CT data from Chinese one-year-old toddler head with substantial and detailed information, the head model with detailed anatomical structure was constructed by using the medical software Mimics to get the head geometry data, as well as the reverse engineering software to divide NURBS surface and build the geometric model. Finally, the FE pre-processing software was used mesh the model. The FE model of one-year-old toddle head was validated by data from anatomic and cadaver experiments, and was used for preliminary analysis on damage mechanism of one-year-old toddler head. Results The FE model of Chinese one-year-old male toddler head was developed, which included and distinguished the gray matter and white matter of brain and cerebellum, hippocampus, fontanel, sagittal suture, coronal suture, brainstem and ventricles. The cadaver head static compression experiments and drop experiments were reconstructed by using this head model, and the results showed that the FE model of head had similar mechanical properties with the cadaver, which proved the validity of the FE model. Simulation results showed that skull stiffness and skull injury severity varied with different compression rates. Conclusions The FE model of one-year-old toddler head with detailed anatomical structures is of great biofidelity. The FE head model can be used to further investigate the detailed injury mechanism of deep brain tissues, especially for the closed craniocerebral injury, which provides an effective way and tool for the related research and clinical application.

Objective To construct and validate the 95th percentile finite element model of Chinese human head, evaluate the relative displacement between the skull and brain according to four types of skull brain relative displacement experiments as references, and investigate the shear strain distributions on the brain. Methods By comparing the relative displacement curve derived from the experiment and simulation and referring to conclusions from animal and physical experiments, the position of higher shear strain was investigated. Results High correlations could be found between the simulated and experimental results for skull brain relative displacement. Peaks and troughs could always appear in curves of skull brain relative displacement due to the fact that the brain tissue tended to return to its initial state. The results that higher strain could occur at temporal lobe of the brain, corpus callosum and brain surface were consistent with conclusions from the animal and physical experiments. ConclusionsT he 95th percentile finite element model of Chinese human head is validated with good biofidelity. Due to the rotational motion of human head, higher shear strain will occur on brain surface and in deep brain, leading to injuries, which provids a scientific theoretical basis for the study on injury mechanism of human head in traffic accidents.

Objective In view of the uncertainties of material parameters for child craniocerebral tissues, the effects of such parameters on responses of child head under direct impact loads were investigated. Methods The impact simulation experiments were conducted under direct impact loads by using a validated finite element model of 3-year-old child head. Taguchi orthogonal method and variance analysis were performed to analyze the material properties of craniocerebral tissues in child head. Results Elastic modulus of the skull had statistically significant effects on impact responses of child head. With the skull elastic modulus increasing, the coup pressure decreased significantly (P=0.000), whereas the contrecoup pressure (P=0.000) and maximum Von Mises stress of the skull increased significantly (P=0.000). The linear viscoelastic material parameters of brain tissues also had statistically significant effects on impact responses of child head. With the increase of the short-time shear modulus of brain tissues, the maximum shear stress of brain tissues increased significantly (P=0.000) whereas the maximum principal strain decreased significantly (P=0.000). Conclusions These statistical analysis results can provide references for selecting material parameter of craniocerebral tissues in finite element model of child head, which will be helpful to improve diagnosis accuracy of brain injuries such as concussion difficult to be definitely diagnosed when using brain CT images in clinic.

Brain injury has become the most severe injury in traffic accident due to its high incidence and high fatality rate. The brain injury model plays a critical role in researches on brain injury. The constitutive model and the material properties used in the model are key factors in determining the accuracy of injury prediction. The present paper aims to review the application of constitutive models and material properties in brain simulation so as to better understand biomechanical properties of brain and provide references for finite element researches on brain injury.

Objective To investigate brain responses from children during traffic accident and drop impact by developing a 3-year-old child head finite element (FE) model. Methods Based on the CT data from a 4-year-old child head, the FE child head model with detaile