CO2.

Human parvovirus B19, generally referred to as B19 virus, has been closely associated with a variety of different autoimmune diseases due to the features of its capsid protein. B19 virus VP1 unique region protein that has sites of phospholipase A2 and several antigenic determinants is exposed on the outside of the viral capsid protein. As a result of that, B19 virus VP1 unique region protein can stimulate the host to produce autoantibodies, which induces and/or aggravates the autoimmune diseases. The biological characteristics of B19 virus VP1 unique region protein and its relationships with autoimmune diseases are de-scribed in this review based upon the published literatures and the work achieved by our research team. This review will be helpful to the prevention and treatment of B19 virus infection.

Objective To simulate a finite element model for biomechanical analysis of mandible chin blast injury and analyze the mechanism of maxillofacial blast injury.Methods The three-dimensional element model of human mandible blast injury was established to simulate the dynamic process of injury to the mandible chin.Von Mises stress and effective strain were evaluated in biomechanical study of the simulation results.Results The dynamic damage process of human mandible chin blast injury was simulated successfully.In the condition of 1 000 mg and 3 cm,the Von Mises stress and effective were maximum at condylar neck region (9.1 × 106 Pa,0.62 × 10-3ε),were second at mandibular angle region (6.1 × 106 Pa,0.42 × 10-3ε),and minimum at mental foramen region (6.1 × 106 Pa,0.39 × 10-3ε).Blast distance rather than blast equivalent produced more effect on the mechanical parameters and damage degree.Conclusions Von Mises stress and effective strain can be applied to the evaluation of bone tissue damage.The finite element method is effective in simulating mandible blast injury and can provide a new thought and approach to clinical treatment of oral and maxillofacial blast injury.

Objective To develop a three-dimensional element model of pig mandible impact injury and test the simulation results in an attempt to determine the feasibility and reliability of finite element numerical simulation method used in the maxillofacial impact injury.Methods CT data was used to develop a three-dimensional finite element model of pig mandible impact injury,and the dynamic process of impact injury was simulated.The simulation results were compared with the animal experiment and had energy check to validate the reliability and feasibility of the modeling and simulation methods.Results The three-dimensional finite element model was established successfully,containing 61,512 hexahedrons,5,450 tetrahedrons,4,030 trihedrons,and 67,159 nodes.The simulation process was realistic,and the simulation results showed no statistical difference with the animal experiment with regard to strain,acceleration,and other biomechanical properties (P ＞ 0.05).The simulated damage shape had a high similarity with animal specimens,and the result of energy check also complied with energy conservation law.Conclusion Finite element method is effective to simulate the dynamic process of mandible impact which ensures a correct and reliable model and simulation,and thus can be used to analyze the mechanism of maxillofacial impact injury.

Objective To investigate the neuroprotective effect and mechanism of astragalus injection in cerebral ischemia reperfusion injury in rats .Methods A total of 70 healthy adult male Wistar rats were subjected to establish middle cerebral artery occlusion reperfusion models by inserting a monofilament thread from the external -internal carotid artery and treated by injecting 1g/L intraperitoneally astragalus injection (3ml/kg).The neurobehavioral function of rats was evaluated by Longa ’ s test and the cerebral infarction volume was calculated by tetrazolium chloride staining .The shape and ultrastructure of neurons in parietal cortex were observed by HE stain TEM .The early apoptotic ratio of neurons was detected by flow cytometry .The expressions of c-Jun N-terminal kinase 3 ( JNK3) mRNA and protein were determined by RT-PCR and Western blotting , respectively.Results After treatment with astragalus injection , the expressions of JNK3 mRNA and protein reduced significantly , the number of neuronal apoptosis in parietal cortexminus , the cerebral infarction volume shrink, the neuronal shape and ultrastructure and animal neurobehavioral function were improved significantly than those in model group rats .Conclusion The results suggest that astragalus injection may inhibit neuronal apoptosis , reduce the infarction volume and improve the animal neurobehavioral function by down -regulated the expression of JNK 3 gene following cerebral ischemia in rats .

Objective To investigate the effect of vardenafil on high altitude pulmonary hypertension in rats, and the possible mechanism thereof. Methods Thirty rats were randomly divided into three groups:control group with normal-pres?sure and normal-oxygen (group C), pulmonary hypertension group with low-pressure and low-oxygen (group P), and the group treated by vardenafil in low-pressure and low-oxygen condition (group V). The rats of group P and group V were ex?posed to low-pressure and low-oxygen condition in an auto-modulating hypobaric and hypoxic cabin to simulate 5 000 m high altitude environment (air pressure 50 kPa, oxygen concentration 10%) for 8 hours daily. Vardenafil (1 mg/kg) was given by gastrogavage to rats in group V once daily for 4 weeks, while the isodose distilled water was given by gastrogavage to rats in group C and group P. The mean pulmonary arterial pressure and right ventricular mass index were measured respectively after 4-week treatment. Morphologic changes of peripheral pulmonary artery were detected by light microscope. The serum levels of nitric oxide (NO) and endothelin-1 (ET-1) were detected as well. Results The pulmonary arterial pressure and right ventricular mass index were significantly higher in group P than those of group C and group V (P<0.05). The ratio of vascular medial wall thickness to external diameter (WT%) and the ratio of pulmonary artery wall area to tube area (WA%) were significantly increased in group P than those of group C and group V (P<0.05). Furthermore, the serum level of NO was significantly lower in group P than that of group C and group V, but the serum level of ET-1 was significantly increased compared with that of group C and group V (P<0.05). Conclusion Vardenafil can effectively reduce the pulmonary arteri?al pressure, and attenuate pulmonary vessels and right ventricle remodeling induced by high altitude pulmonary hypertension.

Objective Finite element numerical simulation technique was applied to simulate the dynamic projectile injury process of human chin in different injury conditions and the mechanism of injury was discussed by using biomechanical analysis . Methods The 3D finite element model of human mandible projective injury was established to simulate the dynamic projectile inju‐ry process of human chin in different injury conditions (high ,medium and low speeds) ,and the simulation results were used to com‐parative analysis of biomechanics .Results The dynamic damage process of human chin projectile injury was simulated successfully in different injury conditions ,and the more serious injury of mandible was caused by faster speed .Conclusion The finite element method can simulate the projectile injury of mandible effectively ,and can provide a new thought and method for basic research and clinical treatment of oral and maxillofacial war injury .

Objective The simulation of the human mandible injury was carried out by using the finite element simulation technology ,and the biomechanical analysis of simulation results was developed to explore the mechanism of injuries .Methods The Chinese Visible Human digital data were used to establish the three-dimensional element model of mandible injuries ,and the dynam-ic processes of human mandible injuries in different conditions were simulated ,and the biomechanical analysis were carried out by u-sing the Von Mises stress and effective strain .Results The three-dimensional element model of mandible injuries was established , the dynamic damage and fracture of human mandible were simulated successfully ,the mandibular angle and condylar were the predi-lection parts of high-stress ,high-strain and fractures .Conclusion The Von Mises stress and effective strain can be used to predict and judge the bone tissue injuries ,the finite element method can simulate the impact injuries of mandible effectively ,and the simula-ted results can provide guidance and reference for basic research and clinical treatment of oral and maxillofacial injuries .

Objective:To analyze the causes, influencing factors and trends of dead on arrival cases in children′s Hospital in the past 5 years, aiming to provide direction and basis for reducing the dead on arrival cases of children.Methods:We collected the dead on arrival cases in the department of emergency at Shanghai Children′s Hospital from January 2015 to December 2019, classifed and analysed the gender, age, native place, death season, time of death, and possible causes of death, and then studied the correlation between above factors and the cases.Results:A total of 151 dead on arrival cases were collected.The annual number decreased year by year, and boys were more than girls in gender.Most of them were infants under 1 year old, and nonlocal children were more than Shanghai native.The above differences were statistically significant, but there was no significant difference in the distribution of death season and death time.In terms of the cause of death, perinatal diseases accounting for 33.8%(51/151), those accompanied with severe underlying diseases accounting for 39.1%(59/151), accidental death accounting for 14.6%(22/151), unexplained deaths accounting for 12.6%(19/151). Those distribution differences were statistically significant( χ2=32.497, P<0.001). Meanwhile, there were statistic differences in gender and age of the cases with severe underlying diseases( χ2=4.898, P=0.027; χ2=32.169, P<0.001), and the year and age distributions of the accidental death cases also had significant differences( χ2=16.636, P=0.002; χ2=14.727, P=0.002). Conclusion:To reduce dead on arrival cases of children, we should do a good job in perinatal health care and screening, reduce premature birth and birth defects, actively conduct propaganda to prevent children′s accidental injuries, popularize medical first aid knowledge, and strengthen children′s transport system.

Objective To construct rCB1 gene eukaryotic expression vector, detect its expression in the cell, and explore its influence on apoptosis in human cervical cancer CaSki cells.Methods The total RNA was extracted from rat brains.The rCB1gene was amplified by RT-PCR.The pcDNA3.1(+)-rCB1 was constructed by enzyme digestion, purifi-cation, bind the PCR purification products and pcDNA3.1 (+) DNA.The pcDNA3.1 (+)-rCB1 plasmid was transfect-ed into HEK293 and CaSki cells by liposomes.The expression and localization of rCB1 were detected by Western blot and immunofluorescence combined with confocal laser scanning microscopy.The apoptosis rate of CaSki cells was detected by flow cytometry.The expression of rCB1, Bcl-2, Bax and Bad was detected by Western blot and real-time fluorescence quantitative RT-PCR (qRT-PCR).Results The 5300 bp pcDNA3.1(+) and 1500 bp rCB1 were obtained after diges-ting the pcDNA3.1 ( +)-rCB1.The result of sequencing was in agreement with the sequence of rCB1 gene ( NM_012784.4 ) .The rCB1 expressed in the membrane and cytoplasm when pcDNA3.1 (+)-rCB1 plasmid was transfected into HEK293 cells.The apoptosis rate of rCB1 group was increased compared with the blank group when pcDNA3.1 (+)-rCB1 plasmid was transfected into CaSki cells (P<0.05).Compared with the blank group, rCB1 gene upregulated the expres-sion of Bax and Bad, and suppressed the expression of Bcl-2.The statistical difference was significant ( P <0.05). Conclusions The pCDNA3.1(+)-rCB1 eukaryotic expression vector is constructed successfully.It is found that rCB1 is expressed in membrane and cytoplasm of HEK293 cells.rCB1 can significantly promote the apoptosis in cervical cancer CaSki cells by up-regulating the expression of Bax and Bad, and down-regulating the expression of Bcl-2 as well.