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Objective:To study the clinical value of N-terminal pro-B-type natriuretic peptide (NTproBNP) predicting the risk of bronchopulmonary dysplasia (BPD) in very/extremely low birth weight infants (VLBWI/ELBWI).Methods:From June 2017 to December 2019, VLBWI/ELBWI admitted to neonatal department in our hospital were enrolled in this non-interventional prospective study. According to the occurrence of BPD, the infants were assigned into BPD group and non-BPD group. Infants in BPD group were further assigned into mild, moderate and severe BPD groups. Plasma NTproBNP were measured on 14 d, 21 d, 28 d, 35 d, 42 d and 49 d after birth. Repeated-measures ANOVA was used to determine the differences of NTproBNP at different time points in each group.Results:A total of 190 infants were enrolled, including 36 cases in BPD group (18, 13 and 5 cases in mild, moderate and severe BPD group, respectively) and 154 cases in non-BPD group. The gestational age, birth weight and 5-min Apgar score in BPD group were lower than non-BPD group. BPD group had significantly higher incidences of retinopathy of prematurity, patent ductus arteriosus and necrotizing enterocolitis and significantly longer duration of invasive mechanical ventilation and noninvasive ventilation than non-BPD group ( P<0.05).No significant differences existed in NTproBNP levels between BPD group and non-BPD group on 42 d and 49 d ( P>0.05). At other time points, NTproBNP levels in BPD group were significantly higher than non-BPD group ( P<0.05). NTproBNP level in severe BPD group was the highest on 14 d. No significant differences existed in NTproBNP levels between mild and moderate groups on 28 d ( P>0.05). At other time points, NTproBNP in severe BPD group was higher than mild and moderate BPD groups ( P<0.001). The receiver operating characteristic curve analysis showed the best cut-off value of NTproBNP was 982 pg/ml on 14 d (AUC=0.907, 95% CI 0.831~0.983). Conclusions:VLBWI/ELBWI with BPD have higher levels of NTproBNP. And the more severe of BPD, the higher the NTproBNP level. NTproBNP has certain predictive values for BPD in VLBWI/ELBWI.
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Objective:To analyze the effects of espO gene knockout on the biological characteristics of enterhemorrhagic Escherichia coli (EHEC). Methods:Two-step methods mediated by the suicide plasmid pCVD442-Δ espO and plasmid pTrc99a were used to construct the espO gene-deleted strain (Δ espO) and the complemented mutant (CΔ espO), respectively. HeLa cells were infected with different EHEC strains to analyze the biological functions and lethal effects of espO gene during infection. Results:PCR, electrophoresis and gene sequencing showed that the Δ espO and CΔ espO mutants were successfully constructed. Compared with the wild-type strain, neither the Δ espO nor CΔ espO mutant showed significant difference in growth rate, indicating that the espO gene had no influence on the growth and replication of EHEC. Furthermore, EspO could activate the tumor necrosis factor receptor (TNF)-induced NF-κB signaling pathway, while the effector protein NleB could inhibit the process. EspO could not inhibit the death of HeLa cells induced by TNF or TNF-related apoptosis-inducing ligand (TRAIL) after EHEC infection. Conclusions:In this study, we successfully constructed the espO gene-deleted and complemented mutants of EHEC and preliminarily analyzed the interaction between espO gene and host cells and the effects of espO gene on cell apoptosis during infection, which provided reference for further research on the in vitro biochemical activity and in vivo pathogenic roles of EspO.
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Objective To study the protective effects and preliminary mechanisms of endothelial progenitor cells-derived microvesicles (EPC-MVs) on hypoxic-ischemic brain damage (HIBD) in newborn rats by using the HIBD model.Method Rat endothelial progenitor cells (EPCs) were cultured and microvesicles were extracted from EPCs culture medium by ultracentrifugation.A total of 60 neonatal SD rats were randomly assigned into control group,HIBD group,saline group and EPC-MVs group.The HIBD model was prepared in HIBD group,saline group and EPC-MVs group.After the preparation of the HIBD model,rats in saline group and EPC-MVs group received intraventricular injection with saline and EPC-MVs,respectively.After 72 hours,the rats were sacrificed for brain tissue,cerebral infarction was detected by TTC staining,vascular endothelial growth factor (VEGF) mRNA was tested by real-time PCR,protein western blot was used to detect changes in VEGF protein expression.Result Cells extracted and cultured from the spleen of 12-week-old SD rats were confirmed as EPCs by morphology and flow cytometry.EPC-MVs isolated by high-speed centrifugation from EPCs culture supernatant met the morphological characteristics of microvesicles by transmission electron microscopy.The infarcted brain tissue was not detected in the control group.The cerebral infarction volume ratios of HIBD group,saline group and EPC-MVs group were (80.3 ± 6.3) ％,(77.9 ± 8.9) ％,(35.2 ± 7.7) ％,respectively.The infarct volume of EPC-MVs group was significantly lower than that of HIBD group and saline group (P ＜ 0.001).The expression of VEGF mRNA and protein in HIBD group,saline group and EPC-MVs group were higher than those in control group (P ＜0.001).Among them,EPC-MVs group had the most significant increase,compared with the other three experimental groups,and the difference was statistically significant (P ＜ 0.001).There was no significant difference between saline group and HIBD group in the expression of VEGF mRNA and protein (P ＞ 0.05).Conclusion Intraventricular injection of EPC-MVs can attenuate HIBD in neonatal rats,and the mechanism may be related to up-regulation of VEGF expression.
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<p><b>OBJECTIVE</b>To compare the accuracy of mesiodistal tooth angulation measurements by using traditional panoramic radiographs and cone beam CT (CBCT) panoramic images.</p><p><b>METHODS</b>Plaster models of 15 volunteers with individual normal occlusions were collected. The functional occlusal plane and tooth long axis on the plaster models were marked from the right first molar to the left first molar in the upper and lower dental arches. A radiographic stent, which contains radiopaque markers near the functional occlusal plane and approximating the root axis, was fabricated for each model. Traditional panoramic radiographs and CBCT scan images were obtained from each patient, with the radiographic stent seated on the dentition. A panoramic image reconstruction was made from the CBCT volumetric data by using related software. The CBCT panoramic image data were oriented parallel to the maxillary or mandibular functional occlusal plane containing all the radiopaque markers when measuring the maxillary or mandibular teeth, respectively. The mesiodistal tooth angulations of the plaster model, traditional panoramic radiographs, and CBCT panoramic images were measured and compared. Multivariate analysis of variance and Dunnett-t test were performed to compare the differences among the three methods.</p><p><b>RESULTS</b>The difference among the three methods was statistically significant (P = 0.00). Significant differences compared with the model measurement were found in two teeth (upper second premolar and lower second premolar) among twelve teeth (P = 0.00) in traditional panoramic measurement. CBCT panoramic measurement was not significantly different to model measurement.</p><p><b>CONCLUSION</b>Traditional panoramic radiographs do not provide a more reliable measure of mesiodistal tooth angulation, whereas CBCT panoramic image is an tool for evaluating mesiodistal tooth angulation.</p>
Subject(s)
Humans , Bicuspid , Cone-Beam Computed Tomography , Dental Arch , Dental Occlusion , Image Processing, Computer-Assisted , Maxilla , Molar , Radiography, Panoramic , Tooth , Tooth RootABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of different premolar extraction models on postextraction Bolton overall ratio among different classes of malocclusion.</p><p><b>METHODS</b>180 patients with equivalent skeletal and dental classifications were chosen(Group I, II and III, with 60 per group). According to dental casts, the Bolton overall ratios of each group were measured and compared before and after hypothetical premolar extraction (the four premolar extraction models were all first premolars, all second premolars, upper first and lower second premolars, and upper second and lower first premolars). Chi-square Test analysis was taken within each group in order to compare the abnormal rates of postextraction Bolton overall ratios.</p><p><b>RESULTS</b>The differences of pretreatment Bolton overall ratios among three types of malocclusions were found statistically significant (P=0.000). For Class I and Class II group, the four extraction models made no statistically significant differences in the abnormal rates of postextraction Bolton overall ratio (P>0.05). For Class III group, the four extraction models made statistically different results that was the upper second and lower first premolar extraction model creating lower abnormal rates than the upper first and lower second premolar extraction model (P=0.002).</p><p><b>CONCLUSION</b>As far as the postextraction Bolton overall ratios are concerned, Class I and II malocclusions can choose any of four premolar extraction models, while to Class III malocclusions, the upper second and lower first premolar extraction model fits better than the upper first and lower second premolar extraction model.</p>