ABSTRACT
Objectives To explore the associations between higher antibiotic use rates (AURs) and adverse outcomes in very-low-birthweight (VLBW) infants without culture-proven sepsis or necrotizing enterocolitis (NEC) in a multicenter of China. Methods A prospective cohort study was performed on VLBW infants admitted to 24 neonatal intensive care units from January 1, 2018, to December 31, 2018. AUR was calculated as calendar days of antibiotic therapy divided by total hospital days. The composite primary outcome was defned as mortality or severe morbidity, including any of the following: severe neurologic injury, bronchopulmonary dysplasia (BPD), and stage 3 or higher retinopathy of prematurity. Results A total of 1,034 VLBW infants who received antibiotics without culture-proven sepsis or NEC were included in this study. The overall AUR of eligible VLBW infants was 55%, and the AUR of each eligible VLBW infant ranged from 3 to 100%, with a median of 56% (IQR 33%, 86%). After generalized propensity score and logistic regression analysis of 4 groups of VLBW infants with diferent AUR range, infants in the higher quartile AUR, (Q3, 0.57~0.86) and (Q4, 0.87~1.00), had higher odds of composite primary outcome (adjusted OR: 1.81; 95% CI: 1.23–2.67; adjusted OR 2.37; 95% CI: 1.59–3.54, respectively) and BPD (adjusted OR: 3.09; 95% CI: 1.52–6.57; adjusted OR 3.17; 95% CI: 1.56–6.57, respectively) than those in the lowest AUR (Q1). Conclusions Antibiotic overexposure in VLBW infants without culture-proven sepsis or NEC was associated with increased risk of composite primary outcome and BPD. Rational empirical antibiotic use in VLBW infants is urgently needed in China.
ABSTRACT
The cytokine repertoire of ADP/ATP carrier-specific humoral immune responses and the cytokine-dependent anti-ADP/ATP carrier antibody IgG subclasses were examined in a cohort of ADP/ATP carrier-immunized BALB/c mice treated with anti-CD4 monoclonal antibody. Eighteen male BALB/c mice (6-8 weeks old) were randomized into 3 groups: dilated cardiomyopathy (DCM)group, DCM-tolerance (Tol) group and control group. The mice in DCM group were immunized with the peptides derived from human ADP/ATP carrier protein for 6 months and mice in the control group were sham-immunized, while the mice in DCM-Tol group were immunized with ADP/ATP carrier protein and anti-CD4 McAb simultaneously. Serum autoantibody against ADP/ATP carrier and IgG subclasses were measured by ELISA, intracellular cytokines IFN-γ and IL-4 of Th cells were monitored with flow cytometry, and splenic T cell cytokines IFN-γ, IL-2, IL-4 and IL-6 were detected by using real-time fluorescent quantitative PCR. The results showed that the autoantibody against ADP/ATP carrier was found in all mice in DCM group, and the antibody level, serum IgG1 and IgG2a subclasses, cytokines in T cells and Th cells were all elevated in DCM group, as compared with those in control group (P＜0.01). On the other hand, in DCM-Tol group, the autoantibody level and contents of all the cytokines were significantly different from those in DCM group (P＜0.01), and were close to those in control group. And the levels of IgG1, IgG2a, IgG2b and IgG3 were influenced,to varying degrees, by anti-CD4 McAb as compared with those in DCM group. All these four types of IgG subclasses were substantially decreased in DCM-Tol group as compared with DCM group. It is concluded that the treatment with anti-CD4 McAb could prevent the activation of T cells, reverse the abnormal secretion of cytokines and the imbalance between Th1/Th2 cell subsets and abnormal production of autoantibody against ADP/ATP carrier, and eventually avoid myocardial injuries.
ABSTRACT
This study investigated the effects of propofol on the mRNA expression of Toll-like receptor-4 (TLR4) in BV-2 cells during mimic ischemia-reperfusion (I/R) injury in vitro. BV-2 cells, a mouse microglia line, were cultured and divided into 4 groups at random: control group (group C),ischemia/reperfusion group (group I/R), low-dose propofol (25 μmol/L) intervention group (group PF25) and high-dose propofol (100 μmoi/L) intervention group (group PF100). The mRNA expression of TLR4 and NF-kB was measured by means of RT-PCR. TNF-а levels in the supernatants of BV-2 cells were detected by ELISA. The results showed that the mRNA expression of TLR4 and NF-kB was significantly higher in groups I/R, PF25 and PF100 than in group C (P<0.01). And the TNF-а level in the supernatants was elevated in groups I/R, PF25 and PF100 as compared with that in group C (P<0.01). After pre-treatment with propofol, the mRNA expressions of TLR4 and NF-kB and the TNF-ct level were significantly decreased in groups PF25 and PF100 in comparison to those in group I/R (P<0.01). And the decrease in those indicators was more significant in group PF100 than in group PF25 (P<0.01). It was concluded that propofol exerted brain-protecting effects during I/R injury by suppressing the mRNA expressions of TLR4 and NF-kB and deceasing the TNF-а level.