Primary failure of eruption(PFE) is an unusual dental disease.Clinically,it is difficult to distinguish PFE from Mechanical failure of eruption (MFE),and the diagnosis is especially challenging since misdiagnosis and mistreatment always take place.The present paper reports the treatment experience of a case of PFE.

Objective To study the phase transformations and chemical composition changes of Pyritum Preparata (PP) influenced by different processing. Methods To analyse the changes of microstructure, morphology, mineral phase, and chemical compositions in different PP by ore microscope, electron probe microanalyzer technique. Results Greater changes have taken place in chemical compositions of PP after calcination: pyrite (FeS_2) changed into pyrrhotite (Fe_(1-x)S), even changed into magnetite (Fe_3O_4); and chalcopyrite generated mutation to be low-copper chalcopyrite, the contents of Cu reduced, the rate of Cu/Fe changed. At the same time, in the pyrrhotite around the mutative chalcopyrite, the contents of Cu increased. That is to say, the Cu got into pyrrhotite and generated solid-solution with high dispersion, and then ore became loose and porous. In the hard-burned spot of calcined quenched samples by vinegar, the contents of Pb and S are far lower than non-burned spot, the minimum estimate of Pb is less than 1/10 of crude ore. Conclusion There is a co-relativity between phase transformations and dissolution of chemical compositions before and after calcining PP.

Background The suppression of retinal angiogenesis is one of primary treatment targets for retinal vascular diseases,so seeking the intervention targets of retinal neovascularization is a hot research.Studies showed that insulin-like growth factor 1 (IGF-1) can promote the growth and restrain the apoptosis of vascular endothelial cells.However,whether IGF-1 is an intervention target for the treatment of retinal vascular diseases is unelucidated.Objective This study was to address the effects of IGF-1 on the migration,apoptosis and capillary tube formation of human retinal vascular endothelial cells (HRECs) and mechanism.Methods HRECs were cultured in vitro,and the cells in the exponential phase were prepared for subsequent experiments.The expression of IGF-1R mRNA in the cells was examined using reverse transcriptase PCR assay.Different concentrations of IGF-1 were added in the medium based on the difference of tests.The relative free-cell area difference (△S) after test was measured by Photoshop CS4 software and compared among 0,10 and 200 ng/ml IGF-1 groups 12 and 24 hours after cell scratching,respectively.The cell apoptotic rate was assayed by flow cytometry and compared between 0 ng/ml IGF-1 group and 1 000 ng/ml IGF-1 group,and the number of capillary tubes was examined by Matrigel test and assessed among 0,10,100 and 200 ng/ml IGF-1 groups 24 hours after addition of IGF-1.The expressions of platelet derived growth factor (PDGF)-BB mRNA and caspase-3 mRNA in the cells of the 0,500 and 1 000 ng/ml IGF-1 groups were detected by real-time fluorescence quantitative PCR after adding IGF-1 for 6 hours.Results Cultured cells grew well and attached 90％ confluence 2-3 days after incubation,and IGF-1R mRNA was positively expressed in the cells.In 12 and 24 hours after scratching,the relative migrating area of the cells was gradually reduced with the increase of IGF-1 contents.The △S was (4.83 ± 0.61) × 105 μm2 in the 200 ng/ml IGF-1 group,which was significantly larger than (3.28±0.64) ×105 μm2 in the 0 ng/ml IGF-1 group 24 hours after stretching (t=-3.707,P=0.021).The apoptotic rate in the 0 ng/ml IGF-1 group and 1 000 ng/ml IGF-1 group was (18.77±2.37) ％ and (12.05 ±0.88) ％,with a significant difference between them (t =2.869,P =0.046).The number of intact tubes was significantly increased in the 200 ng/ml IGF-1 group compared with the 0 ng/ml IGF-1 group ([20.33±2.83]/well vs.[17.94± 1.96]/well;t =-2.940,P =0.042).Compared with 0 ng/ml IGF-1 group,the relative expression level of PDGF-BB mRNA was elevated and that caspase-3 mRNA was evidently reduced in the 1 000 ng/ml IGF-1 group (t=-3.489,P =0.025;t =7.287,P =0.002).Conclusions IGF-1 can promote the migration and angiogenesis of HRECs and inhibit the apoptosis of HRECs.These effects of IGF-1 probably are associated with the up-regulation of PDGF-BB and down-regulation of caspase-3 in the cells.

Objective:To investigate parents′ knowledge and attitude toward post-operative pain management in pediatric orthopedics and analyze influencing factors.Methods:A total of 170 parents of 6 to 16 years old children who underwent selective surgeries and were hospitalized because of limb fracture were conveniently selected in Children′s Hospital of Soochow University from April to December in 2019, They were investigated using the general data questionnaire, Pain Management Knowledge and Attitudes Questionnaire.Results:There were 167 parents completed questionnaires in our study. The mean score of parents′ knowledge, general attitude and negative attitude to pain medication were 15.0(3.00), 24.0(4.00) and 17.0(3.00) respectively. There were statistical differences between different educational levels of parents′ knowledge ( χ2 value was11.599, P=0.021), as well as different age of parent′s general attitude ( χ2 value was 7.053, P=0.029). Spearman-related results showed that parents′ cognition was positively correlated with general attitudes ( r value was 0.394, P<0.01). Conclusions:The majority of parents are at moderate to high level of knowledge, general attitude and negative attitude to pain medication. Pediatric nurses should pay more attention to parents′ knowledge deficit of and negative attitude toward pain assessment tools and pain-drugs to develop targeted educational intervention programs for promoting parental involvement.

Objective:To translate the Anticoagulation Knowledge Tool(AKT) into Chinese,and to test its reliability and validity in patients with atrial fibrillation.Methods:After obtaining the authorization of the original author, the Brislin cross-cultural translation method was used to translate from the original, back translate and cross-cultural adaptation of AKT to form the Chinese version of AKT. The reliability and validity were tested in 147 patients with atrial fibrillation from January to June in 2020 in Ruijin Hospital, Shanghai Jiaotong University School of Medicine.Results:The Chinese version retained 20 items of the original questionnaire,with the item content validity index of 0.857-1.000 and the average scale content validity index of 0.85. The Cronbach alpha coefficient was 0.812 and test-retest coefficient was 0.781.Conclusions:The Chinese version of AKT has been proved to be valid and reliable, which can be used to assess anticoagulation knowledge of patients with atrial fibrillation.

Objective:To predict the secondary structure and B cell epitope of human decay accelerating factor Methods:The accuracy of two secondary structure prediction methods,Chou & Fasman and PHDsec,was compared,and then human DAF secondary structure was analyzed by PHDsec Hydrophilicity scores and solvent accessibility of DAF SCR1 4 were obtained by methods of Hopp & Woods and PHDacc respectively Combined with the secondary structure of DAF,the B cell epitopes in DAF were predicted Results:PHDsec which use multiple sequence alignment,achieve a better prediction accuracy There is no alpha helix in SCR1 4 of human DAF but only beta sheet and loop segments; The computer predicted most possible epitope in DAF localize within amino acid residues Pro73 Val79?Arg130 Leu139 and Glu156 Cys163 Conclusion:These results will be useful in estimate of the epitope and activity sites localized within human DAF

Objective To investigate the possibility and feasibility of the whole genome microarray scanning technique in clinical cytogenetic diagnosis of an uncertain karyotype and mentally retarded child. Methods The karyotype analysis of the mental development delayed child was 47, XY+mar. Genomic DNA was extracted from the peripheral blood and the whole genome microarray scanning technique was used to analyze the derivative chromosome. Results The whole genome microar-ray scanning technique indicated the derivative chromosome fragment had originated from 9p13.1-p24.3. Conclusions Com-paring to conventional cytogenetic analysis methods, the whole genome microarray scanning technique is of high resolution, high-throughput and high accuracy, which can detect the submicroscopic chromosomal aberrations and replace the conven-tional karyotype analysis.

BACKGROUND: Inhibiting the degradation of extracellular matrix in the intervertebral disc can delay the degenerative process of intervertebral disc. Matrix metalloproteinases-3 (MMP3) is considered as a key enzyme for degradation of extracelular matrix components such as type II collagen and aggrecan.
OBJECTIVE:To construct the short hairpin RNA lentiviral vector targeting human MMP3 gene and to detect its efficiency of gene silence by infecting human degenerative nucleus pulposus cells.
METHODS:According to the human MMP3 mRNA (NM_002422.4) sequence, four groups of the short hairpin RNA gene sequences targeting MMP3 were designed, synthesized and annealed to form double stranded DNA fragments, which were connected with the LV3 vectors digested by BamHI andEcoRI enzymes, and then transfected into the competent cels. The positive clones were identified by PCR, and analyzed by sequencing. The packaging and titer of lentivirus were determined after transfecting 293T cells. Human degenerative nucleus pulposus cels were infected with lentivirus vector, and the transfection efficiency of each group was observed under inverted fluorescence microscope. The interfering efficiency was detected by real time-PCR and western blot at 72 and 96 hours.
RESULTS AND CONCLUSION:The ds-oligo DNA was successfully inserted into the lentiviral vector as confirmed by electrophoresis and sequence analysis. The recombinant lentivirus was harvested from 293T cels with a viral titer of 1-5 ×108 TU/mL. RNA interference targeting the GCC AGG CTT TCC CAA GCA AAT sequences with the highest interfering efficiency in MMP3 gene at 72 and 96 hours resulted in suppression of MMP3 mRNA expression by 98% and 72%, respectively; and at 96 hours, the interfering efficiency of protein expression was 57.2%. The recombinant lentivirus vector containing RNA interference targeting MMP3 gene is successfuly constructed, which lays a foundation for further studies on the MMP3 function and gene therapy.

Objective To obtain Chinese hamsterovary (CHO) cell line expressing human decay accelerating activity (hDAF) stably and to observe the protective effect of hDAF on heterologous cells under the circumstance of complement activation. Methods The eukaryotic expression vector DAF pcDNA3.1 was constructed and then transfected into CHO cells by lipofection. Monoclones of cells expressing hDAF stably were screened by the method of limiting dilution. hDAF expression was detected by flow cytometry. The decay accelerating activity of hDAF was determined by assay of C3 deposition and 51Cr release. Results The expression vector DAF pcDNA3.1 was successfully constructed, and monoclones of cells expressing hDAF were obtained. CHO cells expressing hDAF could decrease C3 deposition and attenuate the killing effect of activation of the complement system. Conclusion We have obtained CHO cell clones expressing hDAF stably, which is helpful for the further studies of the relationship of the structure with the functions of hDAF.

Objective:To compare the clinical effects of rapid maxillary expansion between tooth-borne and hybrid-borne expanders.Methods:PubMed,Cochrane Library,EMbase,CBM,CNKI,VIP and WanFang Data were searched from the date of their establishment to October 31,2015,to find clinical trials about comparison of rapid maxillary expansion by tooth tissue-borne versus hybrid-borne expanders.The quality of the included studies was evaluated by 2 independent reviewers,and Meta-analysis was performed by using RevMan 5.3 software.Results:8 articles with 206 cases were included.The results of Meta-analysis showed that:there were significant differences between the 2 groups in the changes of the right first molar dental inclination [MD =-1.62,95 ％ CI (-3.18,-0.07)],inter first premolar width [SMD =-0.86,95％ CI(-1.47,0.25)] and molar alveolar inclination [SMD =-0.86,95％ CI(-1.10,-0.20)].There was no significant difference between the 2 groups in the changes of inter first molar ~dth [SMD =-0.08,95％ CI (-0.6l,0.45)],the left first molar dental inclination [MD =-1.12,95％ CI(-2.57,0.33)],maxillary width [SMD =-0.30,95％ CI(-1.08,0.47)].Conclusion:The effect between tooth-borne and hybrid-borne expanders in the expansion of maxillary dental arch is similar.However,tooth-borne expanders may cause greater inclination of first molar and alveolar process.