34 research outputs found

    Use of term reference infants in assessing the developmental outcome of extremely preterm infants: lessons learned in a multicenter study.

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    OBJECTIVE: Extremely preterm (EP) impairment rates are likely underestimated using the Bayley III norm-based thresholds scores and may be better assessed relative to concurrent healthy term reference (TR) infants born in the same hospital. STUDY DESIGN: Blinded, certified examiners in the Neonatal Research Network (NRN) evaluated EP survivors and a sample of healthy TR infants recruited near the 2-year assessment age. RESULTS: We assessed 1452 EP infants and 183 TR infants. TR-based thresholds showed higher overall EP impairment than Bayley norm-based thresholds (O.R. = 1.86; [95% CI 1.56-2.23], especially for severe impairment (36% vs. 24%; p ≤ 0.001). Difficulty recruiting TR patients at 2 years extended the study by 14 months and affected their demographics. CONCLUSION: Impairment rates among EP infants appear to be substantially underestimated from Bayley III norms. These rates may be best assessed by comparison with healthy term infants followed with minimal attrition from birth in the same centers

    Rif1 maintains telomeres and mediates DNA repair by encasing DNA ends

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    In yeast, Rif1 is part of the telosome, where it inhibits telomerase and checkpoint signaling at chromosome ends. In mammalian cells, Rif1 is not telomeric, but it suppresses DNA end resection at chromosomal breaks, promoting repair by nonhomologous end joining (NHEJ). Here, we describe crystal structures for the uncharacterized and conserved ∼125-kDa N-terminal domain of Rif1 from Saccharomyces cerevisiae (Rif1-NTD), revealing an α-helical fold shaped like a shepherd's crook. We identify a high-affinity DNA-binding site in the Rif1-NTD that fully encases DNA as a head-to-tail dimer. Engagement of the Rif1-NTD with telomeres proved essential for checkpoint control and telomere length regulation. Unexpectedly, Rif1-NTD also promoted NHEJ at DNA breaks in yeast, revealing a conserved role of Rif1 in DNA repair. We propose that tight associations between the Rif1-NTD and DNA gate access of processing factors to DNA ends, enabling Rif1 to mediate diverse telomere maintenance and DNA repair functions

    Impact of Optimized Breastfeeding on the Costs of Necrotizing Enterocolitis in Extremely Low Birthweight Infants

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    To estimate risk of NEC for ELBW infants as a function of preterm formula and maternal milk (MM) intake and calculate the impact of suboptimal feeding on NEC incidence and costs

    Neurodevelopmental Impairment Among Extremely Preterm Infants in the Neonatal Research Network

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    Evaluate the spectrum of neurodevelopmental outcome in a contemporary cohort of extremely preterm infants. We hypothesize that the rate of severe neurodevelopmental impairment (NDI) decreases over time. Retrospective analysis of neurodevelopmental outcome of preterm infants ≤27 weeks' gestational age (GA) from a Neonatal Research Network center that completed neurodevelopmental follow-up assessments between April 1, 2011, and January 1, 2015. The Bayley Scales of Infant Development-III (BSID III) and a standardized neurosensory examination were performed between 18 and 26 months' adjusted age. Outcome measures were neurologic examination diagnoses, BSID III cognitive and motor scores, sensory impairment, and the composite outcome of NDI, based on the BSID III cognitive score (analyzed by using a cutoff of <85 or <70), BSID III motor score of <70, moderate or severe cerebral palsy (CP), bilateral blindness, and hearing impairment. Two thousand one hundred and thirteen infants with a mean GA of 25.0 ± 1.0 weeks and mean birth weight of 760 ± 154 g were evaluated. The 11% lost to follow-up were less likely to have private insurance, late-onset sepsis, or severe intraventricular hemorrhage. Neurologic examination results were normal in 59%, suspect abnormal in 19%, and definitely abnormal in 22%. Severe CP decreased 43% whereas mild CP increased 13% during the study. The rate of moderate to severe NDI decreased from 21% to 16% when using the BSID III cognitive cutoff of <70 (P = .07) or from 34% to 31% when using the BSID III cognitive cutoff of <85 (P = .67). Extremely preterm children are at risk for NDI. Over time, the rate of moderate to severe NDI did not differ, but the rates of severe CP decreased, and mild CP increased

    Neurodevelopmental and Behavioral Outcomes in Extremely Premature Neonates With Ventriculomegaly in the Absence of Periventricular-Intraventricular Hemorrhage

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    Studies of cranial ultrasonography and early childhood outcomes among cohorts of extremely preterm neonates have linked periventricular-intraventricular hemorrhage and cystic periventricular leukomalacia with adverse neurodevelopmental outcomes. However, the association between nonhemorrhagic ventriculomegaly and neurodevelopmental and behavioral outcomes is not fully understood. To characterize the outcomes of extremely preterm neonates younger than 27 weeks' gestational age who experienced nonhemorrhagic ventriculomegaly that was detected prior to 36 weeks' postmenstrual age. This longitudinal observational study was conducted at 16 centers of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. Infants born prior to 27 weeks' gestational age in any network facility between July 1, 2006, and June 30, 2011, were included if they had a cranial ultrasonogram performed prior to 36 weeks' postmenstrual age. Comparisons were made between those with ventriculomegaly and those with normal cranial sonograms. Data analysis was completed from August 2013 to August 2017. The main outcome was neurodevelopmental impairment, defined as a Bayley Scales of Infant and Toddler Development III cognitive score less than 70, moderate/severe cerebral palsy, a Gross Motor Function Classification System score of level 2 or more, vision impairment, or hearing impairment. Secondary outcomes included Bayley Scales of Infant and Toddler Development III subscores, components of neurodevelopmental impairment, behavioral outcomes, and death/neurodevelopmental impairment. Logistic regression was used to evaluate the association of ventriculomegaly with adverse outcomes while controlling for potentially confounding variables and center differences as a random effect. Linear regression was used similarly for continuous outcomes. Of 4193 neonates with ultrasonography data, 300 had nonhemorrhagic ventriculomegaly (7%); 3045 had normal cranial ultrasonograms (73%), 775 had periventricular-intraventricular hemorrhage (18.5%), and 73 had cystic periventricular leukomalacia (1.7%). Outcomes were available for 3008 of 3345 neonates with ventriculomegaly or normal scans (90%). Compared with normal cranial ultrasonograms, ventriculomegaly was associated with lower gestational age, male sex, and bronchopulmonary dysplasia, late-onset sepsis, meningitis, necrotizing enterocolitis, and stage 3 retinopathy of prematurity. After adjustment, neonates with ventriculomegaly had higher odds of neurodevelopmental impairment (odds ratio [OR], 3.07; 95% CI, 2.13-4.43), cognitive impairment (OR, 3.23; 95% CI, 2.09-4.99), moderate/severe cerebral palsy (OR, 3.68; 95% CI, 2.08-6.51), death/neurodevelopmental impairment (OR, 2.17; 95% CI, 1.62-2.91), but not death alone (OR, 1.09; 95% CI, 0.76-1.57). Behavioral outcomes did not differ. Nonhemorrhagic ventriculomegaly is associated with increased odds of neurodevelopmental impairment among extremely preterm neonates
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