68 research outputs found

    Systemic inflammation associated with mechanical ventilation among extremely preterm infants

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    Little evidence is available to document that mechanical ventilation is an antecedent of systemic inflammation in preterm humans. We obtained blood on postnatal day 14 from 726 infants born before the 28th week of gestation and measured the concentrations of 25 inflammation-related proteins. We created multivariable models to assess the relationship between duration of ventilation and protein concentrations in the top quartile. Compared to newborns ventilated for fewer than 7 days (N=247), those ventilated for 14 days (N=330) were more likely to have elevated blood concentrations of pro-inflammatory cytokines (IL-1β, TNF-α), chemokines (IL-8, MCP-1), an adhesion molecule (ICAM-1), and a matrix metalloprotease (MMP-9), and less likely to have elevated blood concentrations of two chemokines (RANTES, MIP-1β), a matrix metalloproteinase (MMP-1), and a growth factor (VEGF). Newborns ventilated for 7-13 days (N=149) had systemic inflammation that approximated the pattern of newborns ventilated for 14 days. These relationships were not confounded by chorioamnionitis or antenatal corticosteroid exposure, and were not altered appreciably among infants with and without bacteremia. These findings suggest that two weeks of ventilation are more likely than shorter durations of ventilation to be accompanied by high blood concentrations of pro-inflammatory proteins indicative of systemic inflammation, and by low concentrations of proteins that might protect from inflammation-mediated organ injury

    Patterns of Blood Protein Concentrations of ELGANs Classified by Three Patterns of Respiratory Disease in the First 2 Postnatal Weeks

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    We examined the association between elevated concentrations of 25 blood proteins in blood spots collected on postnatal days 1, 7, and 14 from infants < 28 weeks gestation who survived to 24 months and the risk of two patterns of early lung disease i.e., early and persistent pulmonary dysfunction (EPPD), and normal early pulmonary function followed by pulmonary deterioration (PD). 38% (N=347) of our cohort had PD, and 43% (N=383) had EPPD. On postnatal day 14, elevated concentrations of two proteins (RANTES and VEGF) were associated with reduced risk of PD. Similarly, the risk of EPPD was also reduced if three proteins had elevated concentrations on postnatal day 14 (RANTES, MMP-1, and VEGF). In contrast, the risk of EPPD was increased if on day 14 two proteins had elevated concentrations (IL-8 and ICAM-1). Inflammation might influence the risk of EPPD and PD, or be a consequence of lung damage or therapies to minimize lung dysfunction

    Blood Protein Concentrations in the First Two Postnatal Weeks That Predict Bronchopulmonary Dysplasia Among Infants Born Before the 28th Week of Gestation

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    Lung inflammation contributes to the pathogenesis of bronchopulmonary dysplasia (BPD) and may be accompanied by a systematic inflammatory response. The objective of this study was to investigate the role of systemic inflammation in the development of BPD in a cohort of extremely low gestational age newborns (ELGANs) by examining the relationships between inflammation-associated proteins in neonatal blood samples and pulmonary outcomes. Proteins were measured in blood specimens collected on postnatal days 1–3, 5–8 and 12–15 from 932 ELGANs. Increased risk of BPD was associated with elevated blood concentrations of a variety of pro-inflammatory cytokines, adhesion molecules and proteases. Reduced risk was prominently associated with increased concentrations of one chemokine, RANTES. Elevations of inflammatory proteins associated with BPD risk occurred during the first days following birth, and inflammation intensified thereafter. Therefore, exposures that promote inflammation after the first postnatal days may be more critical in the pathogenesis of BPD. Fetal growth restriction, a known BPD risk factor, was not accompanied by proteins elevations and therefore does not appear to be mediated by systemic inflammation. By contrast, mechanical ventilation altered protein levels and may be associated with systemic inflammation

    Cryogenic Optical Position Encoders for Mechanisms in the JWST Optical Telescope Element Simulator (OSIM)

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    The JWST Optical Telescope Element Simulator (OSIM) is a configurable, cryogenic, optical stimulus for high fidelity ground characterization and calibration of JWST's flight instruments. OSIM and its associated Beam Image Analyzer (BIA) contain several ultra-precise, cryogenic mechanisms that enable OSIM to project point sources into the instruments according to the same optical prescription as the flight telescope images stars - correct in focal surface position and chief ray angle. OSIM's and BIA's fifteen axes of mechanisms navigate according to redundant, cryogenic, absolute, optical encoders - 32 in all operating at or below 100 K. OSIM's encoder subsystem, the engineering challenges met in its development, and the encoders' sub-micron and sub-arcsecond performance are discussed

    Infectious causes of microcephaly: epidemiology, pathogenesis, diagnosis, and management.

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    Microcephaly is an important sign of neurological malformation and a predictor of future disability. The 2015-16 outbreak of Zika virus and congenital Zika infection brought the world's attention to links between Zika infection and microcephaly. However, Zika virus is only one of the infectious causes of microcephaly and, although the contexts in which they occur vary greatly, all are of concern. In this Review, we summarise important aspects of major congenital infections that can cause microcephaly, and describe the epidemiology, transmission, clinical features, pathogenesis, management, and long-term consequences of these infections. We include infections that cause substantial impairment: cytomegalovirus, herpes simplex virus, rubella virus, Toxoplasma gondii, and Zika virus. We highlight potential issues with classification of microcephaly and show how some infants affected by congenital infection might be missed or incorrectly diagnosed. Although Zika virus has brought the attention of the world to the problem of microcephaly, prevention of all infectious causes of microcephaly and appropriately managing its consequences remain important global public health priorities

    The relationship between organisational characteristics and the effects of clinical guidelines on medical performance in hospitals, a meta-analysis

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    We are grateful to our colleagues involved in the systematic review of guideline dissemination and implementation strategies across all settings especially Cynthia Fraser, Graeme MacLennan, Craig Ramsay, Paula Whitty, Martin Eccles, Lloyd Matowe, Liz Shirran. The systematic review of guideline dissemination and implementation strategies across all settings was funded by the UK NHS Health Technology Assessment Program. Dr Ruth Thomas is funded by a Wellcome Training Fellowship in Health Services Research. (Grant number GR063790MA). The Health Services Research Unit is funded by the Chief Scientists Office of the Scottish Executive Department of Health. Dr Jeremy Grimshaw holds a Canada Research Chair in Health Knowledge Transfer and Uptake. However the views expressed are those of the authors and not necessarily the funders.Peer reviewedPublisher PD

    The Relationship of Maternal Prepregnancy Body Mass Index and Pregnancy Weight Gain to Neurocognitive Function at Age 10 Years among Children Born Extremely Preterm

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    OBJECTIVE: To assess the association between maternal prepregnancy body mass index and adequacy of pregnancy weight gain in relation to neurocognitive function in school-aged children born extremely preterm. STUDY DESIGN: Study participants were 535 ten-year-old children enrolled previously in the prospective multicenter Extremely Low Gestational Age Newborns cohort study who were products of singleton pregnancies. Soon after delivery, mothers provided information about prepregnancy weight. Prepregnancy body mass index and adequacy of weight gain were characterized based on this information. Children underwent a neurocognitive evaluation at 10 years of age. RESULTS: Maternal prepregnancy obesity was associated with increased odds of a lower score for Differential Ability Scales-II Verbal IQ, for Developmental Neuropsychological Assessment-II measures of processing speed and visual fine motor control, and for Wechsler Individual Achievement Test-III Spelling. Children born to mothers who gained an excessive amount of weight were at increased odds of a low score on the Oral and Written Language Scales Oral Expression assessment. Conversely, children whose mother did not gain an adequate amount of weight were at increased odds of a lower score on the Oral and Written Language Scales Oral Expression and Wechsler Individual Achievement Test-III Word Reading assessments. CONCLUSION: In this cohort of infants born extremely preterm, maternal obesity was associated with poorer performance on some assessments of neurocognitive function. Our findings are consistent with the observational and experimental literature and suggest that opportunities may exist to mitigate risk through education and behavioral intervention before pregnancy

    Sensitivity and performance of the Advanced LIGO detectors in the third observing run

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    On April 1st, 2019, the Advanced Laser Interferometer Gravitational-Wave Observatory (aLIGO), joined by the Advanced Virgo detector, began the third observing run, a year-long dedicated search for gravitational radiation. The LIGO detectors have achieved a higher duty cycle and greater sensitivity to gravitational waves than ever before, with LIGO Hanford achieving angle-averaged sensitivity to binary neutron star coalescences to a distance of 111 Mpc, and LIGO Livingston to 134 Mpc with duty factors of 74.6% and 77.0% respectively. The improvement in sensitivity and stability is a result of several upgrades to the detectors, including doubled intracavity power, the addition of an in-vacuum optical parametric oscillator for squeezed-light injection, replacement of core optics and end reaction masses, and installation of acoustic mode dampers. This paper explores the purposes behind these upgrades, and explains to the best of our knowledge the noise currently limiting the sensitivity of each detector
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