1.Biomechanical study on the impact injure of human mandible by finite element method
Ziyang YANG ; Songbo QIU ; Yu LIU ; Po WU ; Yinghui TAN
Journal of Practical Stomatology 2016;32(3):377-382
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.
2.Safety and efficacy of mitomycin nanoparticles in inhibiting scar proliferation after glaucoma filtration surgery
Ying LI ; Juan TANG ; Changfen LI ; Qilin FANG ; Xingde LIU ; Dan ZHANG ; Tingting ZHANG ; Xiaoli WU ; Tao LI
International Eye Science 2024;24(11):1708-1714
AIM: To prepare a nanodrug MMC-ATS-@PLGA using polylactic acid hydroxyacetic acid copolymer(PLGA)as a carrier and mitomycin C(MMC)loaded on PLGA, and to analyse the biological safety and treatment effect of this nanodrug on inhibiting the proliferation of filtering bleb scarring after glaucoma surgery in vivo.METHODS: The thin-film dispersion hydration ultrasonic method was used to prepare the MMC-ATS-@PLGA, and its physical and chemical properties were detected. The effect of MMC-ATS@PLGA on rabbit corneas was analysed through corneal fluorescence staining and HE staining, and tear film rupture time(BUT), Schirmer test and intraocular pressure data were collected to analyse ocular surface biosafety. A slit lamp was used to observe and calculate the filtration bubble size, and the tissue morphological changes were analysed by conjunctival HE staining. In addition, immunohistochemistry and Elisa were used to compare the anti-inflammatory effects of Flumiolone Eye Drops(FML), MMC, and MMC-ATS-@PLGA nanoparticles on inhibiting the formation of filtering bleb scarring after glaucoma surgery from multiple perspectives via comparative proteomic analysis.RESULTS: The average particle size and zeta potential of MMC-ATS-@PLGA were 128.78±2.54 nm and 36.49±4.25 mV, respectively, with an encapsulation efficiency and a drug loading rate of(78.49±2.75)% and(30.86±1.84)%, respectively. At 33°C(the ocular surface temperature), the cumulative release rate of the MMC-ATS-@PLGA nanoparticles reached(76.58±2.68)% after 600 min. Moreover, corneal fluorescence staining, HE, BUT, Schirmer, and intraocular pressure results showed that MMC-ATS-@PLGA had good biocompatibility with the ocular surface of rabbits. At 3 wk after surgery, the area of filtering blebs in the MMC-ATS-@PLGA group was significantly larger than that in the FML group and MMC group, and the filtering blebs in the control group had basically disappeared. Pathological tissue analysis of the conjunctiva in the filtering blebs area of the eyes of the rabbits revealed that compared with that in the normal group, the morphology of the collagen fibres in the MMC-ATS-@PLGA group was relatively regular, the fibres were arranged neatly, and the tissue morphology was similar to that of the normal group. Immunohistochemistry and Elisa confirmed that compared with those in the normal group, the expression levels of α-SMA, CTGF, and type Ⅲ collagen fibre antibodies were significantly increased in the control group. After FML, MMC, or MMC-ATS-@PLGA treatment for 3 wk, the expression of inflammatory factors gradually decreased. Among the groups, the MMC-ATS-@PLGA group showed the most significant decrease(P<0.05).CONCLUSION: This study successfully synthesized a nanomedicine(MMC-ATS-@PLGA)that inhibits scar proliferation after glaucoma filtration surgery. The drug had stable physicochemical properties, good biocompatibility, and better anti-inflammatory effects by inhibiting the expression of α-SMA, CTGF, and type Ⅲ collagen fibres, which can prevent the formation of scarring in the filtering blebs area, thereby improving the success rate of glaucoma filtering surgery.
3.Effect of 15d-PGJ2 on endotoxin-induced acute lung injury in rats
Rui LYU ; Yan WU ; Jianghua SHEN ; Ziyang ZENG ; Bin YI ; Kaizhi LU
Chinese Journal of Anesthesiology 2015;35(9):1128-1130
Objective To evaluate the effect of 15-deoxy-△12,14-prostaglandin J2 (15d-PGJ2) on endotoxin-induced acute lung injury (ALI) in rats.Methods Forty healthy male Sprague-Dawley rats, aged 3-5 months, weighing 220-250 g, were randomly divided into 4 groups (n =10 each) using a random number table: control group (group C), 15d-PGJ2 group, lipopolysaccharide (LPS) group, and LPS +15d-PGJ2 group.In group 15d-PGJ2, 15d-PGJ20.3 mg/kg was injected via the tail vein, while the equal volume of normal saline was given in group C.In LPS and LPS+15d-PGJ2 groups, ALI was produced with LPS 6 mg/kg injected through the tail vein, and then the equal volume of normal saline and 15d-PGJ2 0.3 mg/kg were injected, respectively.At 4 h after LPS injection, blood samples were drawn from the abdominal aorta for blood gas analysis, and arterial oxygen partial pressure (PaO2) was recorded.The rats were then sacrificed, lungs were removed for microscopic examination, and for determination of wet/dry lung weight ratio (W/D ratio), TNF-α, IL-8 and cytokine-induced neutrophil chemoattractant-1 (CINC-1) contents (by enzyme-linked immunosorbent assay) , and nuclear factor kappa B (NF-κB) p65 and IκB-α expression (by Western blot).Results Compared with group C, no significant change was found in PaO2, W/D ratio, contents of TNF-α, IL-8 and CINC-1, and expression of NF-κB p65 and IκB-α in group 15d-PGJ2 (P>0.05), and PaO2 was significantly decreased, W/D ratio and contents of TNF-α,IL-8 and CINC-1 were increased, the expression of NF-κB p65 was up-regulated, and the expression of IκB-α was down-regulated in LPS and LPS+ 15d-PGJ2 groups (P<0.05).Compared with group LPS,PaO2 was significantly increased, W/D ratio and contents of TNF-α, IL-8 and CINC-1 were decreased, the expression of NF-κB p65 was down-regulated, and the expression of IκB-α was up-regulated (P<0.05),and the pathological changes were attenuated in group LPS+ 15d-PGJ2.Conclusion 15d-PGJ2 can mitigate endotoxin-induced ALI in rats.
4.Etiology and bone age of 2132 children with short stature
Su WU ; Sumei WANG ; Ziyang ZHU ; Wei GU ; Shining NI ; Xing SHI ; Qianqi LIU
Journal of Clinical Pediatrics 2015;(8):730-733
ObjectiveThe aim of this study is to analyze the etiology and status of bone age of children with short stat-ure.MethodsAnthropological and physical examination data were retrospectively collected and studied in 2132 children with short stature in the department of endocrinology between 2009 and 2014. Growth hormone (GH) levels were determined by ar-ginine-clonidine test. Bone age was determined by CHN scoring.ResultsAmong the 2132 patients, 1333 were males and 799 were females. Mean age is 9.03 ± 3.04 years old, mean bone age is 6.81 ± 3.05 years. Of them, 324 cases (15.2%) were diagnosed complete GH deifciency, 780 cases (36.59%) were partial GH deifciency, 27cases (1.27%) were multiple pituitary hormone de-ifciency, 13 cases (1.64%) were hypothyroidism, 893 cases (41.89%) were idiopathic short stature, 19 cases (0.89%) were small for gestational age (SGA), 40 cases (1.88%) were chromosomal disorders, etc. Signiifcant difference in age and bone age was found using t test (P<0.05). Signiifcant differences in Δage were found between etiological categories using ANOVA (P=0.000). Δage was signiifcantly and negatively associated with peak GH using Pearson's correlation.ConclusionsGH deifciency is the most common cause of short stature. Bone age of children with short stature is commonly delayed. Δage was signiifcantly and negatively associated with peak GH. Multiple pituitary hormone deifciency has a signiifcant effect on bone age. The etiology of patients with short stature cannot be determined just by bone age.
5.Analysis of cognition and motivation of blood donation for blood donors in blood collection vehicles
Heshan TANG ; Ziyang FENG ; Xianyao MU ; Chunyan WU ; Zi WANG ; Baohua QIAN
Chinese Journal of Blood Transfusion 2017;30(7):799-800
Objective To investigate the status of blood donation in Shanghai streets,understanding the motivation of the donors for blood donation and how many times they had donate their blood.Here,we intend to improve work efficiency in order to better serve the blood donators and to provide a theoretical basis.Methods To gain insight into the understanding and attitude of citizens for blood donation,we analyzed the volunteer blood donors in 387 vehicles and 436 outdoor pre mobilization object by six months,questionnaire in blood collection vehicle or at scene etc.Results The survey specifically reflected the understanding,attitude and motivation of citizens and foreign workers for blood donation in Shanghai.Conclusion There existed many problems such as wrong recognition,diversified motivation among many citizens for blood donation.More publicity and education for the knowledge of blood donation are needed and it plays significant and longlasting role for blood donation.
6.Experimental study on establishment of a 3D finite element model of human craniomaxillofacial region and its use in impact injury simulation
Yu LIU ; Ziyang YANG ; Po WU ; Gang ZHANG ; Songbo QIU ; Yinghui TAN
Chinese Journal of Trauma 2016;32(2):161-165
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.