Abstract:
:Synchronized atrial contraction may be much more important in the newborn, who has a faster heart rate and a less compliant ventricle, than in the adult. We therefore investigated the extent by which synchronized atrioventricular contraction contributes to cardiac output and cardiac work in a neonatal circulation, and whether this effect can be fully explained by the Starling mechanism. In neonatal piglets, left ventricular pressure and volume (conductance catheter) were measured during atrial and ventricular pacing. By manipulating preload during atrial pacing, end-systolic pressure and volume, stroke work, and dP/dtmax were compared at the same end-diastolic volume as indices of contractility. Finally, end-diastolic pressure-volume relationships were assessed to investigate the validity of using end-diastolic pressure as an indicator of preload. We found a significant contribution of synchronized atrial contraction; cardiac output increased 27% when pacing mode was switched form ventricular to atrial. The mechanism by which this was achieved is entirely the enhancement of ventricular filling and thus the Starling effect; contractility was unaffected by pacing mode. This large and important effect can be explained by slowed relaxation (compared with the adult ventricle), which impairs passive filling during the ventricular relaxation phase, and makes active filling during atrial contraction more important. In addition, we found that the use of end-diastolic pressure as an indicator of preload, instead of end-diastolic volume, leads to serious misinterpretations, due to not only the nonlinearity of this relationship, but also the possible shifts in this relationship with certain interventions.
journal_name
Pediatr Resjournal_title
Pediatric researchauthors
Klautz RJ,Baan J,Teitel DFdoi
10.1203/00006450-199803000-00004subject
Has Abstractpub_date
1998-03-01 00:00:00pages
331-7issue
3eissn
0031-3998issn
1530-0447journal_volume
43pub_type
杂志文章abstract::The neonate conserves sodium avidly, and sodium intake is normally limited to that present in maternal milk. To evaluate the role of atrial natriuretic peptide (ANP) in this adaptation, preweaned rat pups were artificially reared and fed a formula with either normal sodium (25 mEq/L) or high sodium (145 mEq/L) for 7-8...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/00006450-199608000-00017
更新日期:1996-08-01 00:00:00
abstract::In order to study the neonatal microcirculation, the capillary hemodynamics in skin was investigated in 43 full-term infants 2-7 days after birth. The nailfold capillaries of the thumb were visualized by means of television microscopy and the capillary blood cell velocity (CBV) was videophotometrically quantified in 1...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/00006450-198806000-00011
更新日期:1988-06-01 00:00:00
abstract::This review article examines the National Institutes of Health's (NIH) overall budget and its pediatric research funding across three time periods: predoubling [fiscal year (FY) 1992-1997]; doubling (FY 1998-2003); and postdoubling (FY 2004-2009). The average annual NIH appropriations increased by 5.4%, 13.4%, and 1.3...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/PDR.0b013e31818912fd
更新日期:2008-11-01 00:00:00
abstract::Heart rate variability (HRV) is reported increasingly in pediatric research, but different strategies used to identify and manage potential outlier beats impact HRV parameter values in adults and animals. Do they in pediatrics? To compare the impact of different strategies to identifying and managing outliers, we used...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/PDR.0b013e318123fbcc
更新日期:2007-09-01 00:00:00
abstract::In the small bowel of patients with cystic fibrosis, primary defects involving both chloride transport and mucus secretion have been demonstrated, but there is no general consensus about the morphologic counterpart of functional and biochemical abnormalities. We have studied the intestinal mucosa in a group of patient...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/00006450-199802000-00013
更新日期:1998-02-01 00:00:00
abstract::A recently introduced test measures the concentration of transferrin receptor (TfR) in serum, which increases shortly after the onset of iron deficiency. In adults this increase reflects the degree to which tissue iron availability is impaired. We developed a fluoroimmunoassay to quantify TfR. The purpose of this stud...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/00006450-199309000-00011
更新日期:1993-09-01 00:00:00
abstract::Periventricular leukomalacia (PVL), the major substrate of neurologic deficits in premature infants, is associated with reduced white matter volume. Using immunomarkers of axonal pathology [beta-amyloid precursor protein (beta-APP) and apoptotic marker fractin], we tested the hypothesis that widespread (diffuse) axona...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/PDR.0b013e31816c825c
更新日期:2008-06-01 00:00:00
abstract::Intracellular levels of cysteine (CSH) and reduced glutathione (GSH) in the kidney and liver of rats from the newborn to the adult period have been determined using a sensitive high performance liquid chromatography method. In the kidney, the intracellular level of free CSH increased 4-fold from 1 to 4 nmol/mg protein...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/00006450-198711000-00025
更新日期:1987-11-01 00:00:00
abstract::The aim of the present study was to determine the proportion of gamma/delta T-lymphocytes and CD16/CD56 (CD3- and CD3+) cells in the peripheral blood of children and adolescents with Graves' disease (GD; n = 27; mean age, 15.5 +/- 5.1 y) and nontoxic nodular goiter (NTNG; n = 25; mean age, 15.2 +/- 5.7 y), in comparis...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/01.PDR.0000076663.94850.44
更新日期:2003-09-01 00:00:00
abstract::The present study examined the extent to which abundance of the prolactin receptor (PRLR) and a range of primary mitochondrial proteins are influenced by either maternal nutrition and/or fetal number in adipose tissue. Pregnant sheep were control fed [consuming 100% of total metabolizable energy (ME) requirements (tak...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/01.PDR.0000047653.73271.C4
更新日期:2003-02-01 00:00:00
abstract::The mononuclear cells of newborn infants compared to those of normal adults contain diminished activity of pyruvate kinase (PK) (14.9 +/- 1.2 vs. 22.3 +/- 1.3 mumol/10(10) cells/min) and phosphoglycerate kinase (PGK) (195 +/- 10 vs. 415 +/- 19). These deficiencies are accentuated in the cells of premature infants (4.9...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/00006450-197710000-00008
更新日期:1977-10-01 00:00:00
abstract::We have previously demonstrated that enterally administered heparin-binding EGF-like growth factor (HB-EGF) produced in Escherichia coli decreases the incidence and severity of intestinal injury in a neonatal rat model of necrotizing enterocolitis (NEC). In preparation for upcoming human clinical trials, large-scale p...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/PDR.0b013e3181994fa0
更新日期:2009-04-01 00:00:00
abstract::Developmental differences in myocardial performance are known to exist. It is likely that the profile of protein isoforms present on the developing thin filament contributes to these observed differences. We have prepared thin filaments from developing and mature rat hearts by using an immunoprecipitation procedure de...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/00006450-199109000-00006
更新日期:1991-09-01 00:00:00
abstract::Energy and nitrogen balances were measured in growing low birthweight infants fed either mother's expressed breast milk or a 20 kcal per ounce formula to determine whether or not there were differences between the two dietary groups in (1) the partition of energy among excretion, expenditure, and storage and (2) the r...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/00006450-198311000-00011
更新日期:1983-11-01 00:00:00
abstract::Vascular dopamine (DA1) receptors may modulate circulatory hemodynamics in lambs. We evaluated resting dopaminergic tone in lambs by pharmacologically manipulating peripheral DA1 receptors with i.v. SCH 23390, (a highly selective, competitive DA1 receptor antagonist) and i.v. fenoldopam, (a highly selective DA1 recept...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/00006450-199302000-00018
更新日期:1993-02-01 00:00:00
abstract::The first days of postnatal life are energetically demanding as metabolic functions change dramatically to accommodate drastic environmental and physiologic transitions after birth. It is increasingly appreciated that metabolic pathways are not only crucial for nutrition but also play important roles in regulating inf...
journal_title:Pediatric research
pub_type: 杂志文章,评审
doi:10.1038/s41390-019-0647-6
更新日期:2020-01-01 00:00:00
abstract::The effects of fetal hypoxemia on blood coagulation (platelet count, prothrombin time, partial thromboplastin time, fibrinogen, factors II, V, VI, VIII, IX, X, XI, XII, XIII and von Willebrands activities, fibrin degradation products, and fibrin monomer) were evaluated in nine chronically catheterized fetal lambs earl...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/00006450-198201001-00003
更新日期:1982-01-01 00:00:00
abstract::To determine the influence of an altered carotid body function on the laryngeal chemoreflex (LCR) response, reflex apnea was induced by laryngeal water stimulation during normoxia or acute hypoxia in unanesthetized awake lambs in which the ventilatory response to acute hypoxia was attenuated by prolonged postnatal hyp...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/00006450-199312000-00024
更新日期:1993-12-01 00:00:00
abstract:BACKGROUND:Later life metabolic dysfunction is a well-recognized consequence of being born small for gestational age (SGA). This study has applied metabolomics to identify whether there are changes in these pathways in prepubertal short SGA children and aimed to compare the intracellular and extracellular metabolome in...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1038/pr.2016.72
更新日期:2016-08-01 00:00:00
abstract::A sensitive and rapid high-performance liquid chromatography method for determining lecithin/sphingomyelin (L/S) ratios in small volume tracheal aspirates has been evaluated in 115 infants sampled within 3 h of delivery. Respiratory distress syndrome was present in 41 infants and all had L/S ratios of less than or equ...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/00006450-198708000-00010
更新日期:1987-08-01 00:00:00
abstract::Clinical trials demonstrated decreasing rates of bronchopulmonary dysplasia in preterm infants with hypoxic respiratory failure treated with inhaled nitric oxide (iNO). However, the molecular and biochemical effects of iNO on developing human fetal lungs remain vastly unknown. By using a well-characterized model of hu...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/PDR.0b013e3181d4f20f
更新日期:2010-05-01 00:00:00
abstract::The ontogeny of glutamine uptake by jejunal brush border membrane vesicles was studied in suckling and weanling rats and compared with the data obtained from previous studies done on adult rats in our laboratory. Glutamine uptake represented transport into the intravesicular space rather than mere binding into the mem...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/00006450-199005000-00021
更新日期:1990-05-01 00:00:00
abstract::Pathomechanisms involved in obstructive apneas remain obscure. Apnea arousal failure has been proposed as a cause for sudden death during sleep. The present study hypothesizes an interdependency between upper airway dilating submental muscle electromyogram (EMG) activity (EMGsub), diaphragmatic muscle activity (EMGdia...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/00006450-199509000-00005
更新日期:1995-09-01 00:00:00
abstract:BACKGROUND:Early recognition of patients at risk for sepsis is paramount to improve clinical outcomes. We hypothesized that subtle signatures of illness are present in physiological and biochemical time series of pediatric-intensive care unit (PICU) patients in the early stages of sepsis. METHODS:We developed multivar...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1038/s41390-019-0518-1
更新日期:2019-11-01 00:00:00
abstract::The objective of this study was to investigate changes of cerebral oxygenation and hemodynamics related to opening of the bypass bridge during veno-arterial extracorporeal membrane oxygenation (ECMO). Ten newborn infants and 12 piglets were studied during opening of the bridge for 10 and 1 s, respectively. Changes in ...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/00006450-199507000-00022
更新日期:1995-07-01 00:00:00
abstract::Response characteristics of a transcutaneous PO2 electrode to step changes in PaO2 were determined. In vitro lag time and 95% response time of a transcutaneous PO2 monitor were compared to in vivo response. Release of arterial occlusion was used to produce rapid local PaO2 changes in human infants and adults. In vitro...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/00006450-198102000-00012
更新日期:1981-02-01 00:00:00
abstract::This study was undertaken to determine whether simultaneous activation of clotting, fibrinolysis, and kinin-kallikrein is associated with disease severity in preterm infants with neonatal respiratory distress syndrome (RDS), during the first 5 d of life. In the infants with severe RDS, we found activation of clotting,...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/00006450-199701000-00019
更新日期:1997-01-01 00:00:00
abstract::BackgroundSotos syndrome (SoS) is an overgrowth disorder with various congenital anomalies and is usually accompanied by other clinical problems. However, anorectal malformations have not been documented as part of the SoS entity. Our objective is to report on a case of SoS associated with Hirschsprung's disease (HSCR...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1038/pr.2017.106
更新日期:2017-07-01 00:00:00
abstract::A child diagnosed at birth as deficient in red blood cell adenosine deaminase (ADA) but with substantial residual lymphocyte ADA has been evaluated for two and one-half years. The only immunologic abnormality observed was hypogammaglobulinemia during the fifth month of life. This was unexpected because children with t...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/00006450-198007000-00009
更新日期:1980-07-01 00:00:00
abstract::The purpose of the present study was to determine if autoregulation of cerebral blood flow (CBF) is present in the preterm fetal lamb and, if present, to measure the range of mean arterial blood pressure over which autoregulation exists. Thirty-seven measurements of CBF were made in seven preterm fetal lambs (118-122 ...
journal_title:Pediatric research
pub_type: 杂志文章
doi:10.1203/00006450-198502000-00001
更新日期:1985-02-01 00:00:00