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Biomedical subjects

E W Adcock

Publications and source records attributed to E W Adcock.

18 recordsLinked to original sources
PubMed1992

Retinol (vitamin A) and riboflavin (vitamin B2) administration and metabolism in very low birth weight infants.

The combination of marginal hepatic retinol stores at delivery and the reduction of daily retinol dose due to complications with the delivery system places the VLBW infant receiving parenteral nutrition at high risk for retinol deficiency during the first month of life. This has serious health implications because retinol is essential during this period for normal growth and repair of the pulmonary tissue in VLBW infants. Enterally fed VLBW infants, on the other hand, receive relatively higher doses of retinol from vitamin-supplemented premature infant formula and fortified breast milk. Equally serious is the problem of monitoring vitamin A status in infants receiving supplemental doses of vitamin A. It seems clear that while plasma vitamin A levels are the most easily available method of monitoring vitamin A status, further studies are necessary to determine if these levels correlate with hepatic content. This is of particular concern since liver disease is common in VLBW infants and vitamin A hepatotoxicity has been described in a cohort of 41 patients receiving therapeutic doses of the vitamin. While further research of daily enteral and parenteral retinol requirements of VLBW infants should continue, formulation of a specific VLBW parenteral vitamin supplement should also be developed.

Delivery, Obstetric↗
PubMed1991

Prospective observations of 100 high-risk neonates by high-field (1.5 Tesla) magnetic resonance imaging of the central nervous system: I. Intraventricular and extracerebral lesions.

The results of observations of the first 100 neonates at the University of Texas Health Science Center (Houston) who received magnetic resonance imaging of the central nervous system by means of a high-field image (1.5 T) are reported. All were assessed prospectively to be at risk neurodevelopmental delay. This first report specifically addresses the appearance of primarily hemorrhagic intracranial lesions, including intraventricular hemorrhage (n = 28), and extracerebral lesions, which include 3 cases of venous sinus thrombosis (n = 20). The signal intensities of hemorrhage underwent a characteristic evolution with time with only minor variations in the study group. Magnetic resonance imaging detected direct evidence of hemorrhage for up to 2 months, but hemosiderin was detected as a late indicator of hemorrhage for up to 9 months. Magnetic resonance imaging was equal in benefit to head ultrasonography and computed tomography for the diagnosis of intraventricular hemorrhage, but magnetic resonance imaging was also able to approximate the time of onset of hemorrhage. Magnetic resonance imaging was superior for the evaluation of extracerebral hemorrhage; ultrasonography failed to detect any of these lesions and computed tomography detected only 3 of 7. Short-term neurological abnormality was assessed, but the ability of magnetic resonance imaging to predict long-term neurodevelopmental delay is unknown and is the subject of an ongoing project.

Cerebral Hemorrhage↗
PubMed1991

Prospective observations of 100 high-risk neonates by high-field (1.5 Tesla) magnetic resonance imaging of the central nervous system. II. Lesions associated with hypoxic-ischemic encephalopathy.

One hundred neonates determined prospectively to be at risk for neurologic handicap underwent magnetic resonance imaging with a high-field (1.5 T) imager. Thirty-three demonstrated a total of 37 lesions consistent with hypoxic-ischemic encephalopathy, including periventricular leukomalacia (n = 12), basal ganglia hemorrhage (n = 5), multicystic encephalomalacia (n = 5), and focal parenchymal hemorrhage (n = 15). Diagnoses by ultrasonography and computed tomography were compared with those by magnetic resonance imaging in 29 and 17 infants, respectively. Ultrasonography agreed more frequently with magnetic resonance imaging than did computed tomography. Ultrasonography detected 79% of lesions demonstrated by magnetic resonance imaging whereas computed tomography detected only 41%. Periventricular leukomalacia was seen most often in preterm infants, basal ganglia hemorrhage and multicystic encephalomalacia primarily occurred in term infants, and focal parenchymal hemorrhage occurred at all gestational ages. Basal ganglia hemorrhage and multicystic encephalomalacia were strongly associated with histories of perinatal asphyxia, seizures, and early abnormal neurological status. All infants with basal ganglia hemorrhage (5/5) and multicystic encephalomalacia (5/5) and the majority with periventricular leukomalacia (9/12) and focal parenchymal hemorrhages (9/15) had developmental abnormalities at discharge.

Brain Ischemia↗
PubMed1990

Twenty-four hour in-house coverage for neonatal intensive care units in academic centers: who, how, and why?

Twenty-four-hour in-house coverage by attending physicians is becoming more common in academic centers in certain subspecialties in pediatrics. The actual percentage of programs providing this coverage in most subspecialties is not documented. We report the results of a survey of in-house coverage by attending physicians in neonatal intensive care units at academic centers in the United States. Of the 238 surveys distributed, 204 (86%) were returned and completed. At the time of the survey, 47 of 204 programs (23%) provided 24-hour in-house coverage for their neonatal intensive care units. These programs had more manpower than those programs not providing this coverage. If this trend continues, it will significantly alter projections for neonatal manpower needs in the United States.

Academic Medical Centers↗
PubMed1979

Intraventricular hemorrhage in the neonate born at term.

Four term infants were found by computerized cerebral tomography (CT) to have intraventricular hemorrhage. All were male infants who had experienced substantial intrapartum complications. One infant had subtle clinical signs at 2 days of age; the others had major neurologic findings including seizures and ophthalmoplegia that occurred at 1, 4, and 6 weeks of age, respectively. Three infants in whom the hemorrhages were indistinguishable by CT from those described in preterm infants now have arrested hydrocephalus and normal development. The fourth infant was found to have a large glioblastoma at the site of origin of his initial hemorrhage. These cases emphasize the need to consider this diagnosis in neonates born at term who have abnormal neurologic signs.

Brain Neoplasms↗
PubMed1979

Neonatal gastric motility in dogs: maturation and response to pentagastrin.

Postnatal changes in the pH of gastric secretions, gastric motility, serum gastrin concentration, and response of the stomach to pentagastrin administration were studied in 15 beagle puppies from birth to 5 wk of age. Motility was monitored manometrically via twin-lumen catheters 3--6 h postprandially. Mean gastric pH was stable at 5.85 until the 7th postnatal day when pH decreased to 3.45; pH then increased to a mean value of 4.95 through the 18th day. Antral contractions increased from 0.2 contractions per min on the day of birth to a maximum 2.3 contractions per min on the 11th day and then gradually declined. Pentagastrin (8.0 microgram/kg sc) had no effect on gastric pH or motility until the 2nd postnatal wk. Pentagastrin inhibited the rate and peak pressure of antral contractions from the 2nd through the 5th wk. Mean serum gastrin concentrations in six puppies were greater than values for adult dogs, attaining a preweaning maximum on the 9th day.

Aging↗
PubMed1978

Determination of newborn special care bed requirements by application of queuing theory to 1975-1976 morbidity experience.

The movement of newborn infants from the delivery room of a level III perinatal center to nursing units that provided different levels of care was prospectively documented for 1975 and 1976. These data were employed in a computer modeling experiment based on sequential queuing theory to determine the relationships between numbers of available intermediate and maximum care nursery beds, the probability that a given newborn arrival could not be accommodated, and the occupancy rates for each level of care. The nursery bed requirements for the level III center were used to estimate the number of special care beds needed by the regional Health Service Area.

Bed Occupancy↗
PubMed1978

Effect of uterine artery insulin infusions on umbilical glucose uptake in sheep.

Although glucose is an important fuel for fetal oxidative metabolism, regulation of its availability to the mammalian fetus is poorly understood. This study was performed to determine the effect of infusions of insulin into the uterine arterial circulation on umbilical uptake of glucose in chronically instrumented, unstressed sheep. Twenty-eight determinations of umbilical glucose uptake and diffusion clearance of glucose by the placenta were made in four ewes. Immediately following a control study during which saline was infused into the uterine artery, porcine regular insulin diluted in saline was infused at 0.05 to 8.1 mU/min . kg uterine weight for 20--30 min and the determinations were repeated. Subsequent studies were performed at the conclusion of additional infusions of insulin to a maximum of 21.6 mU/min . kg. There was a significant increase in umbilical glucose uptake during initial insulin infusions (4.47 +/- 0.6 mg/min . kg fetus) compared to the control studies (3.08 +/- 0.6 mg/min . kg) associated with an increase in diffusion clearance (13.8 +/- 1.9 ml/min . kg fetus vs. 8.99 +/- 1.8 ml/min . kg). When the total cumulative dose of exogenous insulin, It, was 162 mU/kg uterine weight or less, the umbilical uptake of glucose, Q, may be expressed as a function of maternal arterial blood glucose concentration in milligrams per dl, [A], and of It.

Animals↗
PubMed1978

Human colostral cytotoxicity: I. Antibody-dependent cellular cytotoxicity against Herpes simplex viral-infected cells mediated by colostral cells.

Human colostral cells in combination with antibody were able to destroy Herpes simplex virus-infected cells (Antibody-dependent cellular cytotoxicity--ADCC) while demonstrating very low spontaneous (non-antibody mediated) cytotoxicity (SCT). The colostral cells involved in ADCC required a high effector to target ratio, were mononuclear, adherent and totally inhibited by latex particles. These results demonstrate that a subpopulation of human colostral macrophages can mediate ADCC against virus-infected target cells. The biologic implications of intact colostral cell ADCC and low SCT in regard to protecting the neonate from infection and maternal cell mediated gastrointestinal damage are discussed.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1977

Osmolalities of infant formulas.

The osmolalities of breast milk and of 36 products that may be fed to infants were determined by the freezing-point depression method. A wide range of osmolality was observed among formulas that provide 67 kcal/100 ml, and many have osmolalities greater than 400 mOsm/kg of water. Reconstituted powdered formulas have osmolalities that are widely varied from batch to batch, are greater when prepared by scoop measures when the osmolalities of corresponding ready-to-feed formulas, and are greater than the osmolalities of the formulas prepared by weighed measures from the manufacturer's formulation. The osmolality of products for oral consumption should be considered in the selection of formulas for preterm infants.

Animals↗
PubMed1977

Syndrome of inappropriate antidiuretic hormone secretion in neonates with pneumothorax or atelectasis.

Nine episodes of the syndrome of inappropriate antidiuretic hormone secretion occurred in five newborn infants following atelectasis or pneumothorax. All infants had pre-existing lung disease and were being treated with positive pressure ventilation. The mean interval between acute atelectasis or pneumothorax and the development of diagnostic hyponatremia, hypo-osmolal serum, hyperosmolal urine, and oliguria was 13.4 hours. Fluid restriction and removal of the triggering event resulted in resolution of the abnormalities within 1.5 to 4 days. Infants who develop atelectasis or pneumothorax should be evaluated for the subsequent occurrence of SIADH; the administration of a water load to them may result in dilutional hyponatremia, for which fluid restriction, not sodium infusion, is the proper therapy.

Acute Disease↗
PubMed1977

Congenital torsion of the penis in father-son pairs.

Congenital torsion of the penis was observed in 5 newborns, 3 of whom had fathers with torsion of the penis. We believe that this common benign condition may be transmitted as an autosomal dominant trait.

Chromosome Aberrations↗
PubMed1977

Rapid karyotypic diagnosis of a case of trisomy 18 in the neonatal intensive care unit.

Recent modifications in the technic of bone marrow preparation for karyotypic analysis permit confirmation of chromosomal aneuploidy such as trisomy 13, 18, or 21 within two to four hours. The patient reported illustrates how the technic of bone marrow karyotyping may assist the pediatrician in treating an acutely ill newborn, in accurately counseling parents, and in selecting with them an appropriate course of management.

Abnormalities, Multiple↗
PubMed1976

Umbilical uptake of amino acids in the unstressed fetal lamb.

The whole blood concentrations of 22 amino acids were measured in a chronic, unstressed fetal lamb preparations. Samples were taken daily from the umbilical artery, umbilical vein, and maternal artery over the latter quarter of gestation. 73 sets of samples (from the umbilical artery and vein and the maternal artery) from 13 animals were analyzed for amino acid levels. Oxygen contents were determined simultaneously in 48 sets (umbilical artery and vein) to relate fetal oxygen consumption to amino acid uptake via the umbilical circulation. The results indicate that there is no umbilical uptake of the acidic amino acids, glutamate and aspartate; there is, in fact, a net flux of glutamate out of the fetus into the placenta. As both of these amino acids are major constituents of body proteins, the data indicate that they are formed within the fetus. The umbilical uptake of some neutral and basic amino acids (e.g., valine, leucine, isoleucine, arginine, phenylalanine, and tyrosine) is in considerable excess of estimated growth requirements, suggesting that some amino acids undergo extensive transamination and oxidative degradation in the fetus. Finally, the net uptake of nitrogen, carbon, and calories by the growing ovine fetus in the form of amino acids, glucose, and lactate is compared to estimated requirements as determined in previous studies.

Amino Acids↗