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Objective:To investigate the association between ureaplasma urealyticum (UU) colonization in the respiratory tract and bronchopulmonary dysplasia (BPD) in extremely preterm or extremely low birth weight infants.Methods:This was a retrospective study involving preterm infants with gestational age <28 weeks or birth weight <1 000 g who was hospitalized in the Neonatal Intensive Care Unit (NICU) of Chengdu Women's and Children's Central Hospital from June 2019 to March 2022. Respiratory tract secretion was collected for UU DNA detection within 24 h after admission. All the participants were divided into the UU-positive or negative groups based on the detection results. Clinical characteristics of the two groups were analyzed using Mann-Whitney U, t-, or Chi-square tests (Fisher exact test). Results:A total of 82 infants were enrolled, including 31 cases (37.8%) in the UU-positive group and 51 patients (62.2%) in the negative group. Among the 30 cases treated with azithromycin in the positive group, 27 (90.0%, 27/30) turned negative after two courses of treatment. The rates of premature rupture of membranes [51.6% (16/31) vs 17.6% (9/51), χ2=10.50] and prenatal antibiotic exposure [71.0% (22/31) vs 47.1% (24/51), χ2=4.47] in the UU-positive group were both higher than those in the UU-negative group (both P<0.05). Multivariate logistic regression analysis showed that premature rupture of membranes ( OR=5.893, 95% CI: 2.016-17.228) and gestational age ( OR=0.663, 95% CI: 0.441-0.999) were independent risk factors for UU colonization (both P<0.05). UU-positive group had a longer duration of oxygen use [ M ( P25- P75), 1 756 h (1 385-2 088 h) vs 1 357 h (1 128-1 656 h), Z=2.98], a longer length of hospital stay [81 d (70-105 d) vs 68 d (59-84 d), Z=3.05], and higher hospitalization costs [(201 574±70 326) yuan vs (161 288±53 412) yuan, t=－2.74] compared to the UU negative group (all P<0.05). The incidence of BPD [74.2% (23/31) vs 47.1% (24/51), χ2=5.80] and retinopathy of prematurity [93.4% (29/31) vs 74.5% (38/51), χ2=4.68] in the UU positive group was higher than those in the UU-negative group (both P<0.05). No significant correlation was found between UU colonization and the severity of BPD ( P>0.05). Conclusion:UU colonization may increase the incidence of BPD, but there was no clear correlation with the severity of BPD.
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Objective:To study the effects of endothelial progenitor cells (EPC)-derived exosomes on hyperoxia-induced injury in type Ⅱ alveolar epithelial cell (AECⅡ) in neonatal rats.Methods:EPCs of rats were cultured and exosomes were collected using Total Exosome Isolation kit. Primary cultured AECⅡof neonatal rats were randomly assigned into three groups: the control group, the hyperoxia group and the exosome group. The control group was cultured in room air with 5%CO 2, the hyperoxia group was cultured in 95%O 2 with 5%CO 2 and the exosome group was cultured with 0.1 mg/ml EPC-derived exosomes in 95%O 2 with 5%CO 2. Cell viability was detected using cell counting kit-8 (CCK-8) and apoptosis was detected using flow cytometry on d2, d4, and d6. Results:EPC-derived exosomes isolated from EPC culture supernatant were confirmed morphologically using transmission electron microscopy. After co-incubation of Dil-labeled EPC-derived exosomes with AEC Ⅱ for 24 h, Dil fluorescence was detected in the cytoplasm of AEC Ⅱ, indicating exosomes were uptaken by AEC Ⅱ. Compared with the control group, hyperoxia decreased cell viability and increased apoptosis of AEC Ⅱ and the injury was aggravated with the prolongation of hyperoxia duration ( P<0.001). Cell injury in the exosome group was milder than the hyperoxia group ( P<0.001). Compared with the control group, cell viability on d4 and d6 of hyperoxia was lower ( P=0.029 and 0.005 respectively) and cell apoptosis at d6 of hyperoxia was higher in the exosome group ( P=0.007). Conclusions:EPC-derived exosomes may partially attenuate hyperoxia-induced cell injury in neonatal rat AEC Ⅱ.
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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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Objective To explore the effectiveness and adverse effect of high frequency oscillation ventilation (HFOV) combined with Sildenafil (SIL) treatment on newborns with persistent pulmonary hypertension (PPHN).Methods A total of 89 cases of PPHN infants collected from Chengdu Women and Children's Central Hospital from Sep.2010 to Sep.2012 were randomly divided into HFOV group,constant mechanical ventilation (CMV) group,HFOV combined SIL group (HFOV + SIL group) and CMV combined with SIL group (CMV + SIL group).The arterial blood gas,pulmonary artery pressure (PAP) and adverse reactions were monitored before and 3 days after treatment.SNK multiple comparison method andx2 test were performed for data before and after treatment among groups for continuous variables and categorical variables,respectively.Results The levels of pa (O2) [(79.1 ± 13.7) mmHg (1 mmHg =0.133 kPa),(77.9 ±14.6) mmHg,(85.4 ±15.2) mmHg],Sa(O2) [(87.8 ±13.4)％,(88.4±15.6)％,(96.1±15.9)％],pa(CO2)[(42.5±11.3) mmHg,(40.2 ±10.5) mmHg,(35.6 ±8.7) mmHg] and PAP [(31.1 ± 8.1) mmHg,(30.4 ± 9.5) mmHg,(25.8 ± 7.3) mmHg] were all improved significantly in CMV + SIL group,HFOV group and HFOV + SIL group compared with those in CMV group[(69.9 ± 12.3) mmHg,(81.1 ± 14.9)％,(48.1 ±9.5) mmHg,(35.6 ±8.9) mmHg] (F =4.629 3,3.673 2,5.865 3,4.849 5,P ＜0.05),especially for HFOV + SIL group(P ＜ 0.05).No significant difference in such indicators was observed between CMV + SIL group and HFOV group (P ＞ 0.05).The effective rate in HFOV + SIL group (90％) was the highest among the 4 groups (x2 =7.938,P ＜ 0.05).During the treatment,all neonates have no adverse reaction.Conclusion The combined use of SIL and HFOV might be a more effective and safer method in the treatment of PPHN of neonate.