The role of nutrition in analysis of risk factors and short-term outcomes for late-onset necrotizing enterocolitis among very preterm infants: a nationwide, multicenter study in China.

BACKGROUND: Necrotizing enterocolitis (NEC) is a serious gastrointestinal disease, primarily affects preterm newborns and occurs after 7 days of life (late-onset NEC, LO-NEC). Unfortunately, over the past several decades, not much progress has been made in its treatment or prevention. This study aimed to analyze the risk factors for LO-NEC, and the impact of LO-NEC on short-term outcomes in very preterm infants (VPIs) with a focus on nutrition and different onset times. METHOD: Clinical data of VPIs were retrospectively collected from 28 hospitals in seven different regions of China from September 2019 to December 2020. A total of 2509 enrolled VPIs were divided into 2 groups: the LO-NEC group and non-LO-NEC group. The LO-NEC group was divided into 2 subgroups based on the onset time: LO-NEC occurring between 8 ~ 14d group and LO-NEC occurring after 14d group. Clinical characteristics, nutritional status, and the short-term clinical outcomes were analyzed and compared among these groups. RESULTS: Compared with the non-LO-NEC group, the LO-NEC group had a higher proportion of anemia, blood transfusion, and invasive mechanical ventilation (IMV) treatments before NEC; the LO-NEC group infants had a longer fasting time, required longer duration to achieve the target total caloric intake (110 kcal/kg) and regain birthweight, and showed slower weight growth velocity; the cumulative dose of the medium-chain and long-chain triglyceride (MCT/LCT) emulsion intake in the first week after birth was higher and breastfeeding rate was lower. Additionally, similar results including a higher proportion of IMV, lower breastfeeding rate, more MCT/LCT emulsion intake, slower growth velocity were also found in the LO-NEC group occurring between 8 ~ 14d when compared to the LO-NEC group occurring after 14 d (all (P < 0.05). After adjustment for the confounding factors, high proportion of breastfeeding were identified as protective factors and long fasting time before NEC were identified as risk factors for LO-NEC; early feeding were identified as protective factors and low gestational age, grade III ~ IV neonatal respiratory distress syndrome (NRDS), high accumulation of the MCT/LCT emulsion in the first week were identified as risk factors for LO-NEC occurring between 8 ~ 14d. Logistic regression analysis showed that LO-NEC was a risk factor for late-onset sepsis, parenteral nutrition-associated cholestasis, metabolic bone disease of prematurity, and extrauterine growth retardation. CONCLUSION: Actively preventing premature birth, standardizing the treatment of grade III ~ IV NRDS, and optimizing enteral and parenteral nutrition strategies may help reduce the risk of LO-NEC, especially those occurring between 8 ~ 14d, which may further ameliorate the short-term clinical outcome of VPIs. TRIAL REGISTRATION: ChiCTR1900023418 (26/05/2019).

Hyperglycemia in pregnancy did not worsen the short-term outcomes of very preterm infants: a propensity score matching study.

Background: Hyperglycemia in pregnancy (HGP) has generally been considered a risk factor associated with adverse outcomes in offspring, but its impact on the short-term outcomes of very preterm infants remains unclear. Methods: A secondary analysis was performed based on clinical data collected prospectively from 28 hospitals in seven regions of China from September 2019 to December 2020. According to maternal HGP, all infants were divided into the HGP group or the non-HGP group. A propensity score matching analysis was used to adjust for confounding factors, including gestational age, twin or multiple births, sex, antenatal steroid administration, delivery mode and hypertensive disorders of pregnancy. The main complications and the short-term growth status during hospitalization were evaluated in the HGP and non-HGP groups. Results: A total of 2,514 infants were eligible for analysis. After matching, there were 437 infants in the HGP group and 874 infants in the non-HGP group. There was no significant difference between the two groups in main complications including respiratory distress syndrome, bronchopulmonary dysplasia, necrotizing enterocolitis, retinopathy of prematurity, patent ductus arteriosus, culture positive sepsis, intraventricular hemorrhage, periventricular leukomalacia, anemia, feeding intolerance, metabolic bone disease of prematurity, or parenteral nutrition-associated cholestasis. The incidences of extrauterine growth retardation and increased growth retardation for weight and head circumference in the non-HGP group were all higher than those in the HGP group after matching (P < 0.05). Conclusions: HGP did not worsen the short-term outcomes of the surviving very preterm infants, as it did not lead to a higher risk of the main neonatal complications, and the infants' growth improved during hospitalization.

Real-world evidence regarding the growth of very premature infants with small for gestational age after birth: a multicenter survey in China.

BACKGROUND: To analyze the real-world growth pattern of very premature infants (VPI) with small for gestational age (SGA) after birth by using the ΔZ value of weight at discharge. METHODS: The clinical data were collected from 28 hospitals in China from September 2019 to December 2020. They were divided into the EUGR(Extrauterine Growth Restriction) and the non-EUGR group according to the criterion of ΔZ value of weight at discharge < -1.28. RESULTS: This study included 133 eligible VPI with SGA. Following the criterion of ΔZ value, the incidence of EUGR was 36.84% (49/133). The birth weight, the 5-min Apgar score, and the proportion of male infants in the EUGR group were lower (P < 0.05). The average invasive ventilation time, cumulative duration of the administration of antibiotics, blood transfusion time, blood transfusion ratio, and total days of hospitalization were significantly higher in the EUGR group (P < 0.05). In the EUGR group, several factors exhibited higher values (P < 0.05), including the initiation of enteral feeding, the volume of milk supplemented with human milk fortifier (HMF), the duration to achieve complete fortification, the cumulative duration of fasting, the duration to achieve full enteral feeding, the length of parenteral nutrition (PN), the number of days required to attain the desired total calorie intake and oral calorie intake, as well as the age at which birth weight was regained. The average weight growth velocity (GV) was significantly lower in the EUGR group (P < 0.001). The incidences of patent ductus arteriosus with hemodynamic changes (hsPDA), neonatal necrotizing enterocolitis (NEC) stage≥ 2, late-onset sepsis (LOS), and feeding intolerance (FI) in the EUGR group were higher (P < 0.05). Multivariate logistic regression analysis showed that birth weight, male, and GV were the protective factors, while a long time to achieve full-dose fortification, slow recovery of birth weight, and NEC stage ≥2 were the independent risk factors. CONCLUSION: SGA in VPI can reflect the occurrence of EUGR more accurately by using the ΔZ value of weight at discharge. Enhancing enteral nutrition support, achieving prompt and complete fortification of breast milk, promoting greater GV, reducing the duration of birth weight recovery, and minimizing the risk of NEC can contribute to a decreased occurrence of EUGR. TRIAL REGISTRATION: CHICTR, ChiCTR1900023418. Registered 26/05/2019, http://www.chictr.org.cn .

[Influence of bronchopulmonary dysplasia on cerebral blood flow in preterm infants: a prospective study based on arterial spin labeling]. / åŸºäºŽåŠ¨è„‰è‡ªæ—‹æ ‡è®°æˆåƒæŠ€æœ¯æŽ¢è®¨æ”¯æ°”ç®¡è‚ºå‘è‚²ä¸è‰¯å¯¹æ—©äº§å„¿è„‘è¡€æµé‡å½±å“çš„å‰çž»æ€§ç ”ç©¶.

OBJECTIVES: To investigate local cerebral blood perfusion in preterm infants with bronchopulmonary dysplasia (BPD) based on cerebral blood flow (CBF) values of arterial spin labeling (ASL). METHODS: A prospective study was conducted on 90 preterm infants with a gestational age of <32 weeks and a birth weight of <1 500 g who were born in the Department of Obstetrics and admitted to the Department of Neonatology in the Third Affiliated Hospital of Zhengzhou University from August 2021 to June 2022. All of the infants underwent cranial MRI and ASL at the corrected gestational age of 35-40 weeks. According to the presence or absence of BPD, they were divided into a BPD group with 45 infants and a non-BPD group with 45 infants. The two groups were compared in terms of the CBF values of the same regions of interest (frontal lobe, temporal lobe, parietal lobe, occipital lobe, thalamus, and basal ganglia) on ASL image. RESULTS: Compared with the non-BPD group, the BPD group had a significantly lower 1-minute Apgar score, a significantly longer duration of assisted ventilation, and a significantly higher incidence rate of fetal distress (P<0.05). After control for the confounding factors such as corrected age and age at the time of cranial MRI by multiple linear regression analysis, compared with the non-BPD group, the BPD group still had higher CBF values of the frontal lobe, temporal lobe, parietal lobe, occipital lobe, basal ganglia, and thalamus at both sides (P<0.05). CONCLUSIONS: BPD can increase cerebral blood perfusion in preterm infants, which might be associated with hypoxia and a long duration of assisted ventilation in the early stage.

Effect of early initiation of enteral nutrition on short-term clinical outcomes of very premature infants: A national multicenter cohort study in China.

OBJECTIVES: The management of enteral nutrition in very preterm infants (VPIs) is still controversial, and there is no consensus on the optimal time point after birth at which enteral nutrition can be started. The aim of this study was to investigate the effect of early initiation of enteral nutrition on the short-term clinical outcomes of VPIs. METHODS: Data of infants (n = 2514) born before 32 wk of gestation were collected from 28 hospitals located in seven different regions of China. Based on whether enteral feeding was initiated within or after 24 h since birth, the infants were divided into an early initiation of enteral feeding (EIEF) group and a delayed initiation of enteral feeding (DIEF) group. RESULTS: Compared with the DIEF group, the EIEF group was more likely to tolerate enteral nutrition and had less need for parenteral nutrition (all P < 0.05). The EIEF group was associated with lower incidence rates of feeding intolerance, extrauterine growth restriction (EUGR), and late-onset sepsis (LOS) (all P < 0.05). There was no significant difference in the incidence of necrotizing enterocolitis (NEC) (Bell stage ≥2) between the two groups (P = 0.118). The multivariate logistic regression analysis revealed that EIEF was a protective factor against EUGR (odds ratio [OR], 0.621; 95% confidence interval [CI], 0.544-0.735; P < 0.001), feeding intolerance (OR, 0.658; 95% CI, 0.554-0.782; P < 0.001), and LOS (OR, 0.706; 95% CI, 0.550-0.906; P = 0.006). CONCLUSIONS: Early initiation of enteral feeding was associated with less frequency of feeding intolerance, EUGR, and LOS, and it may shorten the time to reach total enteral feeding without increasing the risk of NEC.

Analysis of "true extrauterine growth retardation" and related factors in very preterm infants-A multicenter prospective study in China.

Objective: To investigate the incidence and related factors of extrauterine growth retardation (EUGR) and "true EUGR" in very preterm infants (VPI) from different regions of China. Materials and methods: Clinical data of VPI were prospectively collected from 28 hospitals in seven different regions of China from September 2019 to December 2020. The infants were divided into a small for gestational age (SGA) group or non-SGA group at birth, with non-SGA infants at 36 weeks of gestation or at discharge being further divided into a EUGR group or a non-EUGR group. Infants in the EUGR and non-SGA group were defined as "true EUGR." The general information of VPI, such as maternal complications during pregnancy, use of enteral nutrition and parenteral nutrition, and complications during hospitalization were compared between the groups. Results: Among the 2,514 VPI included in this study, 47.3, 41.5, and 33.3% of VPI were below the 10th percentile, and 22.6, 22.4, and 16.0% of VPI were below the 3rd percentile for weight, height, and head circumference at 36 weeks of gestation or at discharge, respectively, by the percentile on the 2013 Fenton curve. The incidences of EUGR and "true EUGR" evaluated by weight were 47.3 and 44.5%, respectively. Univariate analysis showed that there were statistically significant differences in the aspects of perinatal and nutritional characteristics, treatment, and complications between the groups. Multivariate analysis showed that in non-SGA infants, the cumulative caloric intake during the first week was a protective factor for "true EUGR," while days to reach total enteral nutrition, late initiation of human milk fortifier, and moderate to severe bronchopulmonary dysplasia were independent risk factors for "true EUGR." Conclusion: More attention should be paid to the nutritional management of VPI to prevent "true EUGR." Cumulative caloric intake should be ensured and increased during the first week, total enteral nutrition should be achieved as early as possible, human milk fortifier should be added early, and moderate to severe bronchopulmonary dysplasia should be prevented. These strategies are very important for reducing the incidence of "true EUGR" in VPI.

[Establishment of a predictive nomogram model for predicting the death of very preterm infants during hospitalization]. / 极早产儿住院期间死亡的列线图预测模型的建立.

OBJECTIVES: To establish a nomogram model for predicting the risk of death of very preterm infants during hospitalization. METHODS: A retrospective analysis was performed on the medical data of 1 714 very preterm infants who were admitted to the Department of Neonatology, the Third Affiliated Hospital of Zhengzhou University, from January 2015 to December 2019. These infants were randomly divided into a training cohort (1 179 infants) and a validation cohort (535 infants) at a ratio of 7∶3. The logistic regression analysis was used to screen out independent predictive factors and establish a nomogram model, and the feasibility of the nomogram model was assessed by the validation set. The area under the receiver operating characteristic curve (AUC), calibration curve, and decision curve analysis (DCA) were used to assess the discriminatory ability, accuracy, and clinical applicability of the model. RESULTS: Among the 1 714 very preterm infants, 260 died and 1 454 survived during hospitalization. By the multivariate logistic regression analysis of the training set, 8 variables including gestational age <28 weeks, birth weight <1 000 g, severe asphyxia, severe intraventricular hemorrhage (IVH), grade III-IV respiratory distress syndrome (RDS), and sepsis, cesarean section, and use of prenatal glucocorticoids were selected and a nomogram model for predicting the risk of death during hospitalization was established. In the training cohort, the nomogram model had an AUC of 0.790 (95%CI: 0.751-0.828) in predicting the death of very preterm infants during hospitalization, while in the validation cohort, it had an AUC of 0.808 (95%CI: 0.754-0.861). The Hosmer-Lemeshow goodness-of-fit test showed a good fit (P>0.05). DCA results showed a high net benefit of clinical intervention in very preterm infants when the threshold probability was 10%-60% for the training cohort and 10%-70% for the validation cohort. CONCLUSIONS: A nomogram model for predicting the risk of death during hospitalization has been established and validated in very preterm infants, which can help clinicians predict the probability of death during hospitalization in these infants.

Risk factors of extrauterine growth restriction in very preterm infants with bronchopulmonary dysplasia: a multi-center study in China.

OBJECTIVE: Nutritional deficiency soon after birth is a risk factor of chronic lung disease (bronchopulmonary dysplasia, BPD). Afflicted infants are further prone to inadequate growth during hospitalization (extrauterine growth restriction, EUGR). This multi-center retrospective study investigated risk factors of EUGR, specifically in very preterm infants with BPD. METHOD: Data of infants with BPD who were born less than 32 weeks gestation (n = 1010) were collected from 7 regions of China. All infants were non-small for gestational age at birth. Infants were characterized as EUGR or non-EUGR at 36 weeks gestation or discharge, or stratified by gestational age or birthweight. Logistic regression analysis was applied. RESULTS: In 65.5% of the population, the BPD was mild. Infants with severe BPD (8.3%) had the highest rate of EUGR (72.6%, P < 0.001). Groups stratified by gestational age did not differ in rates of EUGR, but the birthweight of the EUGR group was significantly lower than that of the non-EUGR (P < 0.001). Birthweights of < 1000, 1000-1499, and ≥ 1500 g showed EUGR rates of 65.9%, 43.4%, and 23.8%, respectively (P < 0.001). Overall, the independent risk factors of EUGR were: moderate-to-severe BPD, gestational hypertension, cesarean section, cumulative fasting time, time required to achieve 110 kcal/kg/d, and hemodynamically significant patent ductus arteriosus (hsPDA). CONCLUSION: In very preterm infants with BPD, the lower the birthweight or the more severe the BPD, the greater the risk of EUGR. In those with hsPDA, or moderate-to-severe BPD, it is especially important to prevent EUGR through perinatal management, enteral nutrition, and nutritional strategies.

Incidence of extrauterine growth retardation and its risk factors in very preterm infants during hospitalization: a multicenter prospective study. / ä½é™¢æžæ—©äº§å„¿å®«å¤–ç”Ÿé•¿è¿Ÿç¼“åŠç›¸å ³å› ç´ çš„å¤šä¸­å¿ƒå‰çž»æ€§ç ”ç©¶.

OBJECTIVES: To investigate the incidence of extrauterine growth retardation (EUGR) and its risk factors in very preterm infants (VPIs) during hospitalization in China. METHODS: A prospective multicenter study was performed on the medical data of 2 514 VPIs who were hospitalized in the department of neonatology in 28 hospitals from 7 areas of China between September 2019 and December 2020. According to the presence or absence of EUGR based on the evaluation of body weight at the corrected gestational age of 36 weeks or at discharge, the VPIs were classified to two groups: EUGR group (n=1 189) and non-EUGR (n=1 325). The clinical features were compared between the two groups, and the incidence of EUGR and risk factors for EUGR were examined. RESULTS: The incidence of EUGR was 47.30% (1 189/2 514) evaluated by weight. The multivariate logistic regression analysis showed that higher weight growth velocity after regaining birth weight and higher cumulative calorie intake during the first week of hospitalization were protective factors against EUGR (P<0.05), while small-for-gestational-age birth, prolonged time to the initiation of total enteral feeding, prolonged cumulative fasting time, lower breast milk intake before starting human milk fortifiers, prolonged time to the initiation of full fortified feeding, and moderate-to-severe bronchopulmonary dysplasia were risk factors for EUGR (P<0.05). CONCLUSIONS: It is crucial to reduce the incidence of EUGR by achieving total enteral feeding as early as possible, strengthening breastfeeding, increasing calorie intake in the first week after birth, improving the velocity of weight gain, and preventing moderate-severe bronchopulmonary dysplasia in VPIs.

Construction of early risk prediction models for bronchopulmonary dysplasia in preterm infants. / 早产儿支气管肺发育不良早期风险预测模型的构建.

OBJECTIVES: To construct risk prediction models for bronchopulmonary dysplasia (BPD) in preterm infants on postnatal days 3, 7, and 14. METHODS: A retrospective analysis was performed on the medical data of 414 preterm infants, with a gestational age of <32 weeks and a birth weight (BW) of <1 500 g, who were admitted to the neonatal intensive care unit from July 2019 to April 2021. According to the diagnostic criteria for BPD revised in 2018, they were divided into a BPD group with 98 infants and a non-BPD group with 316 infants. The two groups were compared in terms of general status, laboratory examination results, treatment, and complications. The logistic regression model was used to identify the variables associated with BPD. The receiver operating characteristic (ROC) curve was used to evaluate the predictive value of models. RESULTS: The logistic regression analysis showed that BW, asphyxia, grade III-IV respiratory distress syndrome (RDS), acute chorioamnionitis, interstitial pneumonia, fraction of inspired oxygen (FiO2), and respiratory support mode were the main risk factors for BPD (P<0.05). The prediction models on postnatal days 7 and 14 were established as logit (P7) =-2.049-0.004×BW (g) +0.686×asphyxia (no=0, yes=1) +1.842×grade III-IV RDS (no=0, yes=1) +0.906×acute chorioamnionitis (no=0, yes=1) +0.506×interstitial pneumonia (no=0, yes=1) +0.116×FiO2 (%) +0.816×respiratory support mode (no=0, nasal tube=1, nasal continuous positive airway pressure=2, conventional mechanical ventilation=3, high-frequency mechanical ventilation=4) and logit (P14) =-1.200-0.004×BW (g) +0.723×asphyxia+2.081×grade III-IV RDS+0.799×acute chorioamnionitis+0.601×interstitial pneumonia+0.074×FiO2 (%) +0.800×respiratory support mode, with an area under the ROC curve (AUC) of 0.876 and 0.880, respectively, which was significantly larger than the AUC of the prediction model on postnatal day 3 (P<0.05). CONCLUSIONS: BW, asphyxia, grade III-IV RDS, acute chorioamnionitis, interstitial pneumonia, FiO2, and respiratory support mode are the main risk factors for BPD and can be used to construct risk prediction models. The prediction models on postnatal days 7 and 14 can effectively predict BPD.

Role of Neonatal Behavioral Neurological Assessment combined with magnetic resonance diffusion tensor imaging in evaluating white matter development in preterm infants. / NBNAè¯„åˆ†è”åˆç£å ±æŒ¯å¼¥æ•£å¼ é‡æˆåƒåœ¨æ—©äº§å„¿è„‘ç™½è´¨å‘è‚²è¯„ä»·ä¸­çš„ä½œç”¨åŠç›¸å ³æ€§åˆ†æž.

OBJECTIVES: To study the correlation of fractional anisotropy (FA) on magnetic resonance diffusion tensor imaging with Neonatal Behavioral Neurological Assessment (NBNA) score in preterm infants, and to study the role of FA in evaluating white matter development from the perspective of imaging. METHODS: A prospective study was performed for 98 preterm infants who were admitted to the Neonatal Intensive Care Unit of the Third Affiliated Hospital of Zhengzhou University within 24 hours after birth from October 2016 to January 2020. According to the results of NBNA, they were divided into an abnormal group with 51 infants (NBNA score <37) and a normal group with 47 infants (NBNA score ≥37). The FA values of 10 regions of interest were collected and compared between the two groups. The correlations of FA value and umbilical arterial blood gas pH value with the NBNA score were analyzed. RESULTS: Compared with the normal group, the abnormal group had significantly lower FA value of the posterior limb of the internal capsule and umbilical arterial blood pH (P<0.05). The FA value of the posterior limb of the internal capsule and umbilical arterial blood pH were positively correlated with the NBNA score (r=0.584 and 0.604 respectively, P<0.001), and the FA value of the posterior limb of the internal capsule was positively correlated with umbilical arterial blood pH (r=0.426, P<0.05). CONCLUSIONS: The FA value of the posterior limb of the internal capsule can quantitatively reflect white matter development in preterm infants and is correlated with the NBNA score. The combination of the two indices can help to evaluate white matter development in preterm infants more accurately and objectively. Citation.

[A multicenter study of the birth condition of preterm infants and the causes of preterm birth in Henan Province, China].

OBJECTIVE: To investigate the birth condition of preterm infants and the causes of preterm birth in Henan Province, China, and to provide a basis for the prevention and treatment of preterm birth. METHODS: An epidemiological investigation was conducted for live-birth preterm infants who were born in 53 hospitals in 17 cities of Henan Province from January 1, 2019 to December 31, 2019 to investigate the incidence rate of preterm birth, the distribution of gestational age and birth weight, the use of antenatal glucocorticoids, and the causes of preterm birth. RESULTS: The incidence rate of preterm birth was 5.84% (12 406/212 438) in the 53 hospitals. The proportions of preterm infants with gestational ages of < 28 weeks, 28 - < 32 weeks, 32 - < 34 weeks, and 34 - < 37 weeks were 1.58% (196/12 406), 11.46% (1 422/12 406), 15.18% (1 883/12 406), and 71.78% (8 905/12 406) respectively. The proportions of preterm infants with birth weights of < 1 000 g, 1 000- < 1 500 g, 1 500- < 2 500 g, 2 500- < 4 000 g, and ≥ 4 000 g were 1.95% (240/12 313), 8.54% (1 051/12 313), 49.53% (6 099/12 313), 39.59% (4 875/12 313), and 0.39% (48/12 313) respectively. The infants born by natural labor accounted for 28.76% (3 568/12 406), and those born by cesarean section accounted for 70.38% (8 731/12 406). The rate of use of antenatal glucocorticoids was 52.52% (6 293/11 983) for preterm infants and 68.69% (2 319/3 376) for the preterm infants with a gestational age of < 34 weeks. Iatrogenic preterm labor was the leading cause of preterm birth[40.06% (4 915/12 270)], followed by spontaneous preterm birth[30.16% (3 701/12 270)] and preterm birth due to premature rupture of membranes[29.78% (3 654/12 270)]. The top three causes of iatrogenic preterm birth were hypertensive disorders of pregnancy[47.12% (2 316/4 915)], fetal intrauterine distress[22.85% (1 123/4 915)], and placenta previa/placental abruption[18.07% (888/4 915)]. CONCLUSIONS: There is a relatively low incidence rate of preterm birth in Henan Province, and late preterm infants account for a relatively high proportion. Iatrogenic preterm birth is the main cause of preterm birth in Henan Province, and hypertensive disorders of pregnancy and fetal intrauterine distress are the main causes of iatrogenic preterm birth.

The association of γδ-T cells with bronchopulmonary dysplasia in premature infants.

BACKGROUND: As the survival rate of premature infants increases, the incidence of bronchopulmonary dysplasia (BPD), a chronic complication of premature infants, is also higher than before. The pathogenesis of BPD is complicated, and immune imbalance and inflammatory response may play important roles in it. OBJECTIVE: To investigate the correlation between lymphocyte subsets in peripheral blood, especially γδ-T cells, and BPD of preterm infants. MATERIALS AND METHOD: The study was carried out with the peripheral blood of premature infants (GA < 32 weeks, BW < 1500 g), which were collected at 24 h or 3-4 weeks after birth. The infants were divided into non-BPD groups and BPD groups that were classified as mild or moderate and severe in preterm infants based on the magnitude of respiratory support at 28 days age and 36 weeks postmenstrual age. The γδ-T, CD3+, CD4+, CD8+ and total lymphocyte subsets in peripheral blood were detected by flow cytometry. RESULTS: The percentages of T lymphocyte subsets in peripheral blood were not different between BPD and non-BPD within 24 h after birth. And no significant difference was found in T lymphocyte subsets among neonates with BPD of different severities. However, the infants who developed BPD had a significant increase in γδ-T cells compared to non-BPD ones within 3-4 weeks after birth. CONCLUSIONS: It seems that γδ-T cells in peripheral blood are correlated with BPD. However, the causality of BPD and various lymphocytes remains unclear, which need to be further studied.

[An assessment of white matter development in preterm infants with bronchopulmonary dysplasia using diffusion tensor imaging].

OBJECTIVE: To assess white matter development in preterm infants with bronchopulmonary dysplasia (BPD) using fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of diffusion tensor imaging (DTI). METHODS: Ninety-six infants with a gestational age of ≤32 weeks and a birth weight of <1 500 g who were admitted to the neonatal intensive care unit within 24 hours after birth from August 2016 to April 2019 and underwent head MRI and DTI before discharge were enrolled. According to the discharge diagnosis, they were divided into BPD group with 48 infants and non-BPD group with 48 infants. The two groups were compared in terms of FA and ADC values of the same regions of interest on DTI image. RESULTS: There were no significant differences in the incidence rates of periventricular/intraventricular hemorrhage, periventricular leukomalacia, and punctate white matter lesions between the two groups (P>0.05). Compared with the non-BPD group, the BPD group had significantly lower FA values and significantly higher ADC values of the posterior limb of the internal capsule, the splenium of the corpus callosum, the occipital white matter, the cerebellum, and the cerebral peduncle (P<0.05). Compared with the non-BPD group, the BPD group had a significantly higher frequency of apnea, a significantly higher proportion of infants with pneumonia or mechanical ventilation, and a significantly longer duration of assisted ventilation (P<0.05). CONCLUSIONS: BPD may has potential adverse effects to white matter development in preterm infants, leading to delayed white matter development. Therefore, it is necessary to pay attention to the neurological function of these infants.

[Risk factors for poor prognosis of neonatal bacterial meningitis].

OBJECTIVE: To investigate the risk factors for poor prognosis of neonatal bacterial meningitis. METHODS: A retrospective analysis was performed for the clinical data of 152 children with neonatal bacterial meningitis. According to their prognosis, they were divided into a good prognosis group with 122 children and a poor prognosis group with 30 children. The two groups were compared in terms of general status, initial symptoms, and laboratory findings, and the risk factors for poor prognosis were analyzed. RESULTS: Compared with the good prognosis group, the poor prognosis group had a significantly higher proportion of children with a very low birth weight, a peripheral blood white blood cell count (WBC) of <5×109/L or >20×109/L, a C-reactive protein level of >50 mg/L, a cerebrospinal fluid (CSF) WBC of >500×106/L, a CSF glucose level of <1 mmol/L, or a CSF protein level of >2 g/L, as well as significantly higher positive rates of blood culture and/or CSF culture, Gram-positive bacteria, and Streptococcus agalactiae (P<0.05). The multivariate logistic regression analysis showed that a CSF glucose level of <1 mmol/L and a CSF protein level of >2 g/L were independent risk factors for poor prognosis of neonatal bacterial meningitis. CONCLUSIONS: A CSF glucose level of <1 mmol/L and a CSF protein level of >2 g/L are risk factors for poor prognosis of neonatal bacterial meningitis.

[Pathogens and clinical features of preterm infants with sepsis].

OBJECTIVE: To investigate the pathogen composition and clinical features of preterm infants with sepsis, and to provide a basis for early identification and treatment of sepsis in preterm infants. METHODS: A retrospective analysis was performed for the clinical data of 371 preterm infants with sepsis who had a positive blood culture between January 2014 and May 2018. According to the time of onset, the preterm infants were divided into an early-onset group (an age of onset of <7 days) with 73 preterm infants and a late-onset group (an age of onset of ≥7 days) with 298 preterm infants. The two groups were compared in terms of pathogen composition and clinical features (initial symptoms, laboratory examination results at the time of onset, comorbidities, and prognosis). RESULTS: There was a higher proportion of infants with Klebsiella pneumoniae infection in the late-onset group (P<0.05), while there was a higher proportion of infants with Escherichia coli, Streptococcus agalactiae or Listeria infection in the early-onset group (P<0.05). The early-onset group had a significantly higher proportion of infants with dyspnea than the late-onset group (P<0.05). Compared with the late-onset group, the early-onset group had significantly shorter time to negative conversion of blood culture, duration of antibiotic use before infection, and indwelling time of deep venous catheterization (P<0.05), and the late-onset group had a significantly higher incidence rate of neonatal necrotizing enterocolitis than the early-onset group (P<0.05). The early-onset group had a significantly higher rate of treatment withdrawal than the late-onset group (P<0.05). CONCLUSIONS: Preterm infants with sepsis lack typical clinical manifestations and laboratory examination results at the time of onset. There are certain differences in pathogen composition and clinical features between preterm infants with early- and late-onset sepsis. Possible pathogens for sepsis should be considered based on age in days at the time of onset and related clinical features.

MicroRNA-135a participates in the development of astrocytes derived from bacterial meningitis by downregulating HIF-1α.

Accumulating evidence has highlighted the potential of microRNAs (miRs) as biomarkers in various human diseases. However, the roles of miRs in bacterial meningitis (BM), a severe infectious condition, still remain unclear. Thus, the present study aimed to investigate the effects of miR-135a on proliferation and apoptosis of astrocytes in BM. Neonatal rats were injected with Streptococcus pneumoniae to establish the BM model. The expression of miR-135a and hypoxia-inducible factor 1α (HIF-1α) in the BM rat models were characterized, followed by determination of their interaction. Using gain- and loss-of-function approaches, the effects of miR-135a on proliferation, apoptosis, and expression of glial fibrillary acidic protein (GFAP), in addition to apoptosis-related factors in astrocytes were examined accordingly. The regulatory effect of HIF-1α was also determined along with the overexpression or knockdown of HIF-1α. The results obtained indicated that miR-135a was poorly expressed, whereas HIF-1α was highly expressed in the BM rat models. In addition, restored expression levels of miR-135a were determined to promote proliferation while inhibiting the apoptosis of astrocytes, along with downregulated Bax and Bad, as well as upregulated Bcl-2, Bcl-XL, and GFAP. As a target gene of miR-135a, HIF-1α expression was determined to be diminished by miR-135a. The upregulation of HIF-1α reversed the miR-135a-induced proliferation of astrocytes. Taken together, the key findings of the current study present evidence suggesting that miR-135a can downregulate HIF-1α and play a contributory role in the development of astrocytes derived from BM, providing a novel theoretical perspective for BM treatment approaches.

[Effect of early application of recombinant human erythropoietin on white matter development in preterm infants].

OBJECTIVE: To evaluate the effect of early application of recombinant human erythropoietin (rhEPO) on white matter development in preterm infants using fractional anisotropy (FA) of magnetic resonance diffusion tensor imaging (DTI). METHODS: A total of 81 preterm infants with gestational age ≤32 weeks, birth weight <1 500 g, and hospitalization within 24 hours after birth were randomly divided into rhEPO group (42 infants) and control group (39 infants). The infants in the rhEPO group were administered rhEPO, while those in the control group were given the same volume of normal saline. The preterm infants of both groups took examinations of head magnetic resonance imaging, diffusion-weighted imaging, and DTI at the corrected gestational age of 35-37 weeks. FA was calculated for the regions of interest in both groups. RESULTS: There was no significant difference in the incidence of intracranial hemorrhage, periventricular leukomalacia, focal cerebral white matter damage (CWMD), and extensive CWMD between rhEPO and control groups (P>0.05). Compared with the control group, the rhEPO group showed higher FA values at the posterior limb of the internal capsule, the splenium of the corpus callosum, frontal white matter, and occipital white matter (P<0.05). There was no significant difference in FA values at the parietal white matter, thalamus, lenticular nucleus, and caudate nucleus between the two groups (P>0.05). CONCLUSIONS: Early application of rhEPO has a neuroprotective effect on white matter development in preterm infants.

[Clinical features and prognosis of preterm infants with varying degrees of bronchopulmonary dysplasia].

OBJECTIVE: To study the clinical features and prognosis of preterm infants with varying degrees of bronchopulmonary dysplasia (BPD). METHODS: The clinical data of 144 preterm infants with a gestational age of <32 weeks who were admitted to the neonatal intensive care unit from March 2014 to March 2016 and were diagnosed with BPD were collected. According to the severity of BPD, these preterm infants were divided into mild group with 81 infants and moderate/severe group with 63 infants. The two groups were compared in terms of perinatal risk factors, treatment, comorbidities, complications, and prognosis of the respiratory system. RESULTS: Compared with the mild BPD group, the moderate/severe BPD group had a significantly higher gestational age and rate of small-for-gestational-age (SGA) infants (P<0.05), as well as a significantly higher rate of severe preeclampsia and a significantly lower rate of threatened preterm labor (P<0.05). Compared with the mild BPD group, the moderate/severe BPD group had a significantly higher percentage of infants who needed mechanical ventilation at 2 weeks after birth, longer duration of mechanical ventilation, total time of oxygen therapy, and length of hospital stay, and higher incidence rates of pneumonia and cholestasis (P<0.05), as well as a significantly lower application rate of caffeine citrate (P<0.05). The multivariate logistic regression analysis showed that SGA birth (OR=5.974, P<0.05), pneumonia (OR=2.590, P<0.05), and mechanical ventilation required at 2 weeks after birth (OR=4.632, P<0.05) were risk factors for increased severity of BPD. The pulmonary function test performed at the corrected gestational age of 40 weeks showed that compared with the mild BPD group, the moderate/severe BPD group had significantly lower ratio of time to peak tidal expiratory flow to total expiratory time, ratio of volume to peak tidal expiratory flow to total expiratory volume, and tidal expiratory flow at 25% remaining expiration (P<0.05). The infants were followed up to the corrected gestational age of 1 year, and the moderate/severe BPD group had significantly higher incidence rates of recurrent hospital admission for pneumonia and recurrent wheezing (P<0.05). CONCLUSIONS: SGA birth, pneumonia, and prolonged mechanical ventilation are associated with increased severity of BPD. Infants with moderate or severe BPD have poor pulmonary function and may experience recurrent infection and wheezing.

[Effects of caffeine citrate on myelin basic protein in neonatal rats with hypoxic-ischemic brain damage].

OBJECTIVE: To study the effects of caffeine citrate on myelin basic protein (MBP) expression in the cerebral white matter of neonatal rats with hypoxic-ischemic brain damage (HIBD) and the related mechanism. METHODS: Forty-eight seven-day-old Sprague-Dawley neonatal rats were randomly assigned to 3 groups: sham operation (n=16), HIBD (n=16) and HIBD+caffeine citrate (n=16). The rats in the HIBD and HIBD+caffeine citrate groups were subjected to left common carotid artery ligation, and then were exposed to 80 mL/L oxygen and 920 mL/L nitrogen for 2 hours to induce HIBD. The rats in the sham operation group were only subjected to a sham operation, without the left common carotid artery ligation or hypoxia exposure. Caffeine citrate (20 mg/kg) was injected intraperitoneally before hypoxia ischemia (HI) and immediately, 24 hours, 48 hours and 72 hours after HI. The other two groups were injected intraperitoneally with an equal volume of normal saline at the corresponding time points. On postnatal day 12, the expression of MBP in the left subcortical white matter was detected by immunohistochemistry, and the levels of adenosine A1 receptor mRNA and A2a receptor mRNA in the left brain were detected by real-time PCR. RESULTS: The expression of MBP in the left subcortical white matter in the HIBD group was lower than in the sham operation group (P<0.05). The MBP expression in the HIBD+caffeine citrate group was significantly higher than in the HIBD group, but was still lower than the sham operation group (P<0.05). Real-time PCR showed that the adenosine A1 receptor mRNA expression was significantly higher in the HIBD group than in the sham operation group, and it was significantly lower in the HIBD+caffeine citrate group than in the HIBD group (P<0.05). CONCLUSIONS: Caffeine citrate can improve brain white matter damage following HIBD in neonatal rats and the protection mechanism might be related with the down-regulation of adenosine A1 receptor expression.