[Prolonged initial empirical antibiotic treatment and the risk of morbidity and mortality in very low birthweight infants]. / Tratamiento antibiótico empírico inicial prolongado y riesgo de morbimortalidad en recién nacidos de muy bajo peso al nacer.

INTRODUCTION: The objective of this study is to evaluate the association between the duration of ini tial empirical antibiotic treatment and the subsequent development of late-onset sepsis, necrotizing enterocolitis (NEC) and death in very low birth weight (VLBW) infants. PATIENTS AND METHODS: Quantitative, cross-sectional, analytical study of VLBW infants admitted to the neonatal ICU were included over a period of five years. Initial empirical antibiotic therapy was that which started immediately after birth, without knowing the results of blood cultures. It was considered prolonged antibiotic therapy when the treatment duration was > 5 days. Perinatal variables, as well as the inci dence of late-onset sepsis, confirmed NEC and mortality were analyzed. RESULTS: 266 VLBW infants were studied, with an average gestational age and birth weight of 28.8 ± 2.5 weeks and 1.127 ± 264 g respectively. 213 infants received initial empiric antibiotic therapy (80.0%), which was prolonged in 67.6% of cases. All infants received two different antibiotics. 136 episodes of late-onset sepsis were described. The most common pathogens were coagulase-negative Staphylococcus and Staphylococcus aureus. Among the newborns with prolonged antibiotic therapy, there were 20 cases of confirmed NEC and 15 of the studied infants died (10.4%). When comparing the use of antibiotic therapy during > 5 days versus treatment less than 5 days duration, a statistically significant association was observed between prolonged antibiotic therapy and late-onset sepsis (p = 0.03) and confirmed NEC (p = 0.03), but not of mortality (p = 0.12). CONCLUSION: The use of empirical antibiotic therapy for five days or more was associated with an increased risk of late-onset sepsis and NEC, but not of mortality in VLBW infants.

Microglia-derived IL-1ß contributes to axon development disorders and synaptic deficit through p38-MAPK signal pathway in septic neonatal rats.

BACKGROUND: Axon development plays a pivotal role in the formation of synapse, nodes of Ranvier, and myelin sheath. Interleukin-1ß (IL-1ß) produced by microglia may cause myelination disturbances through suppression of oligodendrocyte progenitor cell maturation in the septic neonatal rats. Here, we explored if a microglia-derived IL-1ß would disturb axon development in the corpus callosum (CC) following lipopolysaccharide (LPS) administration, and if so, whether it is associated with disorder of synapse formation in the cerebral cortex and node of Ranvier. METHODS: Sprague-Dawley rats (1-day old) in the septic model group were intraperitoneally administrated with lipopolysaccharide (1 mg/kg) and then sacrificed for detection of IL-1ß, interleukin-1 receptor (IL-1R1), neurofilament-68, neurofilament-160, and neurofilament-200, proteolipid, synaptophysin, and postsynaptic density 95 (PSD95) expression by western blotting and immunofluorescence. Electron microscopy was conducted to observe alterations of axonal myelin sheath and synapses in the cortex, and proteolipid expression was assessed using in situ hybridization. The effect of IL-1ß on neurofilament and synaptophysin expression in primary neuron cultures was determined by western blotting and immunofluorescence. P38-MAPK signaling pathway was investigated to determine whether it was involved in the inhibition of IL-1ß on neurofilament and synaptophysin expression. RESULTS: In 1-day old septic rats, IL-1ß expression was increased in microglia coupled with upregulated expression of IL-1R1 on the axons. The expression of neurofilament-68, neurofilament-160, and neurofilament-200 (NFL, NFM, NFH) and proteolipid (PLP) was markedly reduced in the CC at 7, 14, and 28 days after LPS administration. Simultaneously, cortical synapses and mature oligodendrocytes were significantly reduced. By electron microscopy, some axons showed smaller diameter and thinner myelin sheath with damaged ultrastructure of node of Ranvier compared with the control rats. In the cerebral cortex of LPS-injected rats, some axo-dendritic synapses appeared abnormal looking as manifested by the presence of swollen and clumping of synaptic vesicles near the presynaptic membrane. In primary cultured neurons incubated with IL-1ß, expression of NFL, NFM, and synaptophysin was significantly downregulated. Furthermore, p38-MAPK signaling pathway was implicated in disorder of axon development and synaptic deficit caused by IL-1ß treatment. CONCLUSIONS: The present results suggest that microglia-derived IL-1ß might suppress axon development through activation of p38-MAPK signaling pathway that would contribute to formation disorder of cortical synapses and node of Ranvier following LPS exposure.

Factors associated with neonatal hyperinsulinemic hypoglycemia, a case-control study.

OBJECTIVES: We aimed to identify perinatal risk factors associated with hyperinsulinemic hypoglycemia in neonates. Secondary objectives included an examination of clinical and biochemical characteristics at the time of diagnosis and an exploration of the duration of diazoxide therapy. METHODS: A case-control study was conducted, involving individual chart reviews of inborn infants diagnosed with hyperinsulinemic hypoglycemia (the HH group) between 2014 and 2021. These cases were paired with controls (the non-HH group) belonging to the same gestational age (GA) strata who did not exhibit HH or only had transient postnatal hypoglycemia. RESULTS: A total of 52 infants with HH were matched with corresponding controls. The mean GA in the HH group was 34.4 ± 3.1 weeks. Notably, the HH group exhibited lower mean minimum plasma glucose (PG) levels and required higher glucose infusion rates in comparison to the non-HH group (26.5 ± 15.6 vs. 49.1 ± 37.7 mg/dL and 12.9 ± 3.8 vs. 5.7 ± 2.1 mg/kg/min, respectively; p<0.001 for both). After adjusting for potential confounding factors, only two variables, fetal growth restriction (FGR) and neonatal sepsis, demonstrated significant associations with HH (adjusted odds ratio [95 % confidence interval]: 8.1 [2.1-31.0], p=0.002 and 6.3 [1.9-21.4], p=0.003, respectively). The median duration of diazoxide therapy for the HH group was 4 months. CONCLUSIONS: FGR and neonatal sepsis emerged as notable risk factors for HH. These infants exhibited lower PG levels and necessitated higher glucose infusion rates compared to their non-HH counterparts. Importantly, a substantial proportion of the HH group received diazoxide therapy, with a median treatment duration of 4 months.

Complement C3a induces axonal hypomyelination in the periventricular white matter through activation of WNT/ß-catenin signal pathway in septic neonatal rats experimentally induced by lipopolysaccharide.

Neuroinflammation is thought to play a pivotal role in the pathogenesis of periventricular white matter (PWM) damage (PWMD) induced by neonatal sepsis. Because the complement cascade is implicated in inflammatory response, this study was carried out to determine whether C3a is involved in PWMD, and, if so, whether it would induce axonal hypomyelination. Furthermore, we explored if C3a would act through its C3a receptor (C3aR) and thence inhibit maturation of oligodendrocyte precursor cells (OPCs) via the WNT/ß-catenin signal pathway. Sprague Dawley (SD) rats aged 1 day were intraperitoneally injected with lipopolysaccharide (LPS) (1 mg/kg). C3a was upregulated in activated microglia and astrocytes in the PWM up to 7 days after LPS injection. Concomitantly, enhanced C3aR expression was observed in NG2+ oligodendrocytes (OLs). Myelin proteins including CNPase, PLP, MBP and MAG were significantly reduced in the PWM of 28-day septic rats. The number of PLP+ and MBP+ cells was markedly decreased. By electron microscopy, myelin sheath thickness was thinner and the average g-ratios were higher. This was coupled with an increase in number of NG2+ cells and decreased number of CC1+ cells. Olig1, Olig2 and SOX10 protein expression was significantly reduced in the PWM after LPS injection. Very strikingly, C3aRa administration for the first 7 days could reverse the above-mentioned pathological alterations in the PWM of septic rats. When incubated with C3a, expression of MBP, CNPase, PLP, MAG, Olig1, Olig2, SOX10 and CC1 in primary cultured OPCs was significantly downregulated as opposed to increased NG2. Moreover, WNT/ß-catenin signaling pathway was found to be implicated in inhibition of OPCs maturation and differentiation induced by C3a in vitro. As a corollary, it is speculated that C3a in the PWM of septic rats is closely associated with the disorder of OPCs differentiation and maturation through WNT/ß-catenin signaling pathway, which would contribute ultimately to axonal hypomyelination.

Indole-3-guanylhydrazone hydrochloride mitigates long-term cognitive impairment in a neonatal sepsis model with involvement of MAPK and NFκB pathways.

BACKGROUND: Neonatal sepsis is defined as a systemic inflammatory response caused by a suspected or proven infection, occurring in the first month of life, and remains one of the main causes of morbidity and mortality in newborn and preterm infants. Frequently, survivors of neonatal sepsis have serious long-term cognitive impairment and adverse neurologic outcomes. There is currently no specific drug treatment for sepsis. Indole-3-guanylhydrazone hydrochloride (LQM01) is an aminoguanidine derivative that has been described as an anti-inflammatory, antihypertensive and antioxidant with potential applicability in inflammatory diseases. METHODS: We used a LPS-challenged neonatal sepsis rodent model to investigate the effect of LQM01 on cognitive impairment and anxiety-like behavior in sepsis mice survivors, and examined the possible molecular mechanisms involved. RESULTS: It was found that LQM01 exposure during the neonatal period reduces anxiety-like behavior and cognitive impairment caused by lipopolysaccharides (LPS) in adult life. Additionally, treatment with LQM01 decreased pro-inflammatory cytokine levels and reduced NFκB, COX-2, MAPK and microglia activation in hippocampus of neonatal mice. Furthermore, LQM01 was also able to prevent oxidative damage in hippocampus of neonatal mice and preserve brain barrier integrity. CONCLUSIONS: LQM01 attenuated inflammatory reactions in an LPS-challenged neonatal sepsis mice model through the MAPK and NFκB signaling pathways and microglia activation suppression. All these findings are associated with mitigated cognitive impairment in 70 days-old LQM01 treated-mice. GENERAL SIGNIFICANCE: We revealed the effect of LQM01 as an anti-septic agent, and the role of crucial molecular pathways in mitigating the potential damage caused by neonatal sepsis.

Tratamiento antibiótico empírico inicial prolongado y riesgo de morbimortalidad en recién nacidos de muy bajo peso al nacer / Prolonged initial empirical antibiotic treatment and the risk of morbidity and mortality in very low birthweight infants

Resumen: Introducción: El objetivo de este estudio es evaluar la asociación entre la duración del tratamien to antibiótico empírico inicial y el desarrollo posterior de sepsis tardía, enterocolitis necrotizante (NEC) y muerte en recién nacidos de muy bajo peso al nacer (RNMBP). Pacientes y Método: Estudio cuantitativo, transversal analítico, en RNMBP ingresados a UCI neonatal durante un período de 5 años. Se consideró antibioterapia empírica inicial aquella que comenzó desde el nacimiento, sin conocer resultado de hemocultivos. Antibioterapia prolongada se estimó cuando la duración del tratamiento fue > 5 días. Se analizaron variables perinatales, e incidencia de sepsis tardía, NEC confirmada y mortalidad. Resultados: Se estudiaron un total de 266 RNMBP, con edad gestacional y peso de nacimiento promedios de 28,8 ± 2,5 semanas y 1.127 ± 264 g respec tivamente. Recibieron antibioterapia empírica inicial 213 (80,0%), siendo ésta prolongada en el 67,6%. Todos recibieron antibioterapia biasociada. Se pesquisaron 136 episodios de sepsis tardía, siendo los gérmenes más frecuentes el Staphylococcus coagulasa negativo y el Staphylococcus au reus. Del total de RN con antibioterapia empírica prolongada, hubo 20 casos de NEC confirmada y 15 fallecidos (10,4%) en el grupo analizado. Al comparar el uso de antibioterapia > 5 días ver sus tratamiento menor de 5 días, se observó una asociación estadísticamente significativa entre la antibioterapia prolongada y sepsis tardía (p = 0,03) y además de NEC confirmada (p = 0,03), pero no de mortalidad (p = 0,12). Conclusión: El uso de antibioterapia empírica inicial por 5 días o más se asoció a un riesgo aumentado de sepsis tardía y de NEC, pero no de la mortalidad en RNMBPN.

Abstract: Introduction: The objective of this study is to evaluate the association between the duration of ini tial empirical antibiotic treatment and the subsequent development of late-onset sepsis, necrotizing enterocolitis (NEC) and death in very low birth weight (VLBW) infants. Patients and Methods: Quantitative, cross-sectional, analytical study of VLBW infants admitted to the neonatal ICU were included over a period of five years. Initial empirical antibiotic therapy was that which started im mediately after birth, without knowing the results of blood cultures. It was considered prolonged antibiotic therapy when the treatment duration was > 5 days. Perinatal variables, as well as the inci dence of late-onset sepsis, confirmed NEC and mortality were analyzed. Results: 266 VLBW infants were studied, with an average gestational age and birth weight of 28.8 ± 2.5 weeks and 1.127 ± 264 g respectively. 213 infants received initial empiric antibiotic therapy (80.0%), which was prolonged in 67.6% of cases. All infants received two different antibiotics. 136 episodes of late-onset sepsis were described. The most common pathogens were coagulase-negative Staphylococcus and Staphylococcus aureus. Among the newborns with prolonged antibiotic therapy, there were 20 cases of confirmed NEC and 15 of the studied infants died (10.4%). When comparing the use of antibiotic therapy during > 5 days versus treatment less than 5 days duration, a statistically significant association was observed between prolonged antibiotic therapy and late-onset sepsis (p = 0.03) and confirmed NEC (p = 0.03), but not of mortality (p = 0.12). Conclusion: The use of empirical antibiotic therapy for five days or more was associated with an increased risk of late-onset sepsis and NEC, but not of mortality in VLBW infants.