Early human development
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Early human development · Nov 1998
ReviewThe 'pharmacology' of neuronal rescue with cerebral hypothermia.
The neuroprotective effects of hypothermia during cerebral ischaemia or asphyxia are well known. Although, in view of this, the possibility of a therapeutic role for hypothermia during or after resuscitation from such insults has been a long standing focus of research, early studies had limited and contradictory results. Clinically and experimentally severe perinatal asphyxial injury is associated with a latent phase after reperfusion, with initial recovery of cerebral energy metabolism but EEG suppression, followed by a secondary phase with seizures, cytotoxic edema, accumulation of cytotoxins, and cerebral energy failure from 6 to 15 h after birth. ⋯ Moderate cerebral hypothermia initiated in the latent phase, between one and as late as 6 hours after reperfusion, and continued for a sufficient duration in relation to the severity of the cerebral injury, has been associated with potent, long-lasting neuroprotection in both adult and perinatal species. These encouraging results must be balanced against the adverse systemic effects of hypothermia. Randomised clinical trials are in progress to establish the safety and efficacy of prolonged cerebral hypothermia.
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Bronchopulmonary dysplasia (BPD)/chronic lung disease occurs primarily in very low birth weight infants (VLBW) often without antecedent severe respiratory distress syndrome. The BPD in these VLBW infants results in less fibrosis than the traditional BPD but the normal process of alveolarization seems to be disrupted. This review develops the thesis that BPD in VLBW infants results from inflammatory mediators interfering with the signaling required for normal late gestational lung development. ⋯ The preterm lung is highly susceptible to injury during resuscitation or more chronic mechanical ventilation because the gas volumes/kg body weight of the lungs are small. An understanding of what causes cytokine release and how cytokines influence lung development is necessary to develop targeted therapies to minimize BPD. However, care strategies that minimize inflammation and ventilator-induced lung injury should help decrease BPD.
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Early human development · Nov 1998
Development of baroreflex influences on heart rate variability in preterm infants.
To investigate developmental changes in autonomic cardiovascular reflexes in preterm infants, we used autoregressive power spectral analysis to analyze the effect of upright tilting on heart rate variability in preterm infants. Twenty-eight infants were studied in a longitudinal fashion beginning at 28-32 weeks postconceptional age (postnatal age 1-5 weeks). Each week, heart rate variability in the supine position and after 45 degrees head-up tilt was analyzed by spectral analysis. ⋯ No significant change in these ratios were observed when infants were first studied between 28 and 32 weeks postconceptional age, suggesting that the cardiac baroreflex is poorly developed at this stage of development. However, with postnatal maturation, the LF component of the power spectrum became progressively larger with tilt relative to the basal state, such that the difference between LF/HF(tilt) and LF/HF(base) became progressively more positive (P <0.006). These findings suggest that in premature infants, cardiac baroreceptor reflexes become more functional with postnatal development.
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Early human development · Oct 1998
Increased serum concentrations of soluble tumor necrosis factor receptors p55 and p75 in early onset neonatal sepsis.
Sepsis and pneumonia are major causes of morbidity and mortality in the neonatal period. The symptoms are variable and unspecific. So far, no reliable diagnostic test for neonatal infection has been found. ⋯ Levels of both p55 and p75 decreased in neonates with infection during the perinatal period. CRP was a more specific parameter than p55 and p75 (CRP: 97%, p55: 65% and p75: 75%) whereas the sensitivity of all three parameters was at similar levels (CRP: 59%, p55: 70% and p75: 67%). We conclude that assessment of sTNFR may not improve accuracy in the diagnosis of early onset neonatal sepsis compared to the use of CRP.
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Early human development · Oct 1998
Serial copper and ceruloplasmin levels in African newborns with emphasis on the sick and stable preterm infant, and their antioxidant capacities.
Literature on serum copper (Cu) and its antioxidant protein (ceruloplasmin) in the African newborn is infrequent, and more reports are evident from developed or affluent societies. We, therefore, studied longitudinally our newborns to delineate their Cu and ceruloplasmin (CLP) status. All infants were born between July 1st, 1991 and June 30th, 1992 at the University of Maiduguri Teaching Hospital, Maiduguri, Nigeria. ⋯ Newborns with serum Cu and CLP>0.2 micromol/ml and >2.3 micromol/dl, respectively, did not have a poor outcome. It is tempting to suggest that absent serum CLP activity may portend a poor prognosis. Our findings (number albeit small) could be taken as a preliminary normative data for further comparisons.