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Biomedical subjects

J W Scanlon

Publications and source records attributed to J W Scanlon.

At least 37 records · Page 2Linked to original sources
PubMed1984

The impact of perinatal and neonatal events on the early behavior of the extremely premature human.

Observations were performed on 45 very low birth weight (VLBW) newborns at 7 and 21 days of life, using a Neonatal Behavioral Assessment Scale specifically modified for the extremely premature infant. Findings were analyzed using multiple and stepwise regression techniques to determine the influence of intrapartum and neonatal factors which might influence neurobehavior . Perinatal asphyxial descriptors accounted for significant variance on day 7 behavior; however, their impact was muted for day 21. At this time, jaundice and postnatal nutrition revealed a prominent and independent behavioral influence on the VLBW survivor.

Asphyxia Neonatorum↗
PubMed1983

Effect of theophylline on neurotransmitters in preterm infants with apnea.

Urinary excretion of various catecholamine metabolites (4-hydroxy-3-methoxymandelic acid, homovanillic acid, 3-methoxy-4-hydroxphenylglycol) was studied in preterm infants with idiopathic apnea treated with theophylline. Relief of apnea in these infants was not associated with significant increase in the urinary excretion of various metabolites. We suggest that theophylline does not seem to relieve apnea of prematurity by the stimulation of peripheral catecholamine systems.

Apnea↗
PubMed1983

Respiratory distress syndrome in the newborn: relationship to serum prolactin, thyroxine, and sex.

Prolactin and thyroxine levels were measured by radioimmunoassay in cord blood of 61 premature infants of 26-36 weeks gestation. 30 of the infants subsequently developed respiratory distress syndrome (RDS). The infants who developed RDS had a mean cord prolactin level of 174.5 +/- 24.5 ng/ml and a mean cord thyroxine level of 5.9 +/- 0.4 micrograms/dl. In the 31 healthy infants, the mean cord prolactin and thyroxine levels were significantly higher (226.3 +/- 25.8 ng/ml and 7.1 +/- 0.4 micrograms/dl, respectively). The correlation coefficient between prolactin and thyroxine was r = 0.56 in infants with RDS (p less than 0.0008). Both prolactin and thyroxine correlated with gestational age in the RDS group (r = 0.71 and 0.47, respectively). Discriminant analysis shows that the correlation between prolactin and thyroxine is independent of gestational age (r2 = 0.32, p less than 0.05). There was no correlation between the levels of prolactin and thyroxine in infants without RDS. In the healthy group, the cord prolactin levels were significantly higher (p less than 0.01) in female (335.8 +/- 47.7 ng/ml) than in male infants (209 +/- 17.2 ng/ml). Premature infants who develop RDS have significantly lower thyroxine and prolactin levels in cord blood than infants who remain healthy.

Female↗
PubMed1983

Cerebrospinal fluid concentration of biogenic amine metabolites in idiopathic apnea of prematurity.

The concentration of homovanillic acid and 3-methoxy-4-hydroxyphenylglycol (MHPG), the major metabolites of dopamine and norepinephrine, respectively, were studied in the cerebrospinal fluid (CSF) of 34 newborn infants. No significant difference was found in the levels of MHPG and homovanillic acid between preterm and term infants. Apneic preterm infants had significantly higher levels of MHPG than nonapneic prematures. Theophylline did not change the levels of these metabolites in CSF. There was a progressive rise of MHPG levels in CSF in preterm infants as their postnatal age increased. We suggest that idiopathic apnea of prematurity is not associated with depletion of catecholamine stores in the central nervous system. Theophylline does not seem to relieve apnea by stimulation of the central adrenergic system.

Apnea↗
PubMed1983

Hypernatremia in the very low birthweight infant.

The incidence and cause of hypernatremia in twenty-five very low birthweight infants were determined by a retrospective analysis of their clinical course during the first 72 hours of life. Ten (40%) developed a serum sodium greater than or equal to 150 mEq/l. This was associated with a greater weight loss than found in normal infants (5.3 +/- 2.6%/day vs 1.7 +/- 2.3%/day, p less than .05) and with more time spent under radiant energy, but not with the amount of water, or sodium received. The severity of hypernatremia correlated with birthweight (r = -.47, p less than .05) and with postnatal weight loss but not with sodium intake. The excess weight loss in the hypernatremic group, when added to their average measured fluid intake suggests an estimated optimal fluid requirement of 150 ml/kg/day in the environment described. The hypothesized mechanism for hypernatremia is dehydration, possibly through insensible water loss.

Birth Weight↗
PubMed1982

Nonoliguric acute renal failure in the newborn: a prospective evaluation of diagnostic indexes.

Fifteen newborn babies with azotemia without oliguria were studied. Group A infants had increased BUN levels and decreased creatinine clearance (Ccr) for gestational and postnatal age, and were compared with group B infants, who had increased BUN levels and normal Ccr. The Ccr was 0.35 mL/min in group A and 0.76 mL/min in group B. Urine volume during the same period was 2.45 mL/kg/hr in group A and 4.66 mL/kg/hr in group B. No significant differences in fractional sodium excretion; urine to plasma ratios of creatinine, osmolality, and sodium; and renal failure index were present between the two groups. The results suggest that nonoliguric acute renal failure is a diagnostic entity in the newborn. The Ccr is the most useful indicator for defining renal function in the presence of azotemia and normal urine volume.

Acute Kidney Injury↗
PubMed1982

Study of neurotransmitters in premature infants with or without apnea of prematurity.

Twelve-hour urinary excretion of 4-hydroxy-3-methoxymandelic acid (VMA), homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenylglycol (MHPG) was studied in 20 premature infants, 8 without apnea and 12 with apnea. All infants were studied at 1-3 days of postnatal age (before apnea). Nonapneic infants were restudied at 10-15 days of postnatal age. Apneic infants were also restudied 24 h after apnea. Apnea was not associated with decreased urinary excretion of VMA and MHPG. Only HVA, when expressed as microgram/kg body weight, was significantly lower after the onset of apnea. This difference disappeared when HVA was expressed as microgram/mg creatinine. We suggest that apnea of prematurity may not be related to the immaturity of catecholamine pathways.

Apnea↗
PubMed1982

Effects of oral antibiotics on stool flora and overall sensitivity patterns in an intensive care nursery.

The effects of orally administered gentamicin and colistin on stool bacterial flora and overall antibiotic sensitivity patterns were evaluated in 100 newborns at risk for neonatal necrotizing enterocolitis. Gentamicin (2.5 mg/kg q6h) and colistin (1 mg/kg q6h) were administered to randomly selected groups of 50 newborns for 3 wk after birth during an 11-month study period. Stools were collected on days 1, 11, and 21 and cultures were grown under aerobic conditions on three different media. Staph. epidermidis was the most common predominant organism in both antibiotic groups, whereas E. coli and Klebsiella were the most common Gram-negative bacteria isolated. Seventeen % of these Gram-negative species were resistant to colistin and 9% to gentamicin, with a gradual increase occurring during the 3-wk period. On the basis of 980 positive cultures from all sites in babies in the nursery during the 11-month study, E. coli sensitivity to kanamycin and gentamicin ranged between 92% and 100% except for one month midway through the study when sensitivity to kanamycin was at 80% and then returned to the 92-100% range. Klebsiella sensitivity to both aminoglycosides remained greater than 95% throughout. The incidence of neonatal sepsis remained consistent at seven to nine per 1000 live births during the study. One baby of 50 in the gentamicin group developed necrotizing enterocolitis at 5 wk of age; 0/50 in the colistin group had necrotizing enterocolitis (not significant).

Colistin↗
PubMed1982

Effects of intrapartum maternal glucose infusion on the normal fetus and newborn.

The effect of maternal intravenous glucose infusion on the newborn's glucose, insulin, and neurobehavioral performance was studied prospectively in 56 normal mother-newborn pairs. Maternal blood glucose levels at the time of delivery, umbilical venous blood glucose and insulin levels, and neonatal blood glucose levels were measured. Neurobehavioral assessment of the newborns was performed at 4 and 24 hours of life. The median value for total amount of glucose infused to the mother was 32.5 g, the median rate of glucose infusion was 8 g/h, and the median maternal blood glucose concentration at delivery was 110 mg/dl. Median umbilical venous blood glucose concentrations were 104 mg/dl and median insulin concentration was 15 microunits/ml. Six babies were hypoglycemic at 1 hour of age. Umbilical venous glucose and insulin levels correlated significantly (p less than 0.001) with the rate of glucose infusion to the mother and her blood glucose level. The incidence of neonatal hypoglycemia was significantly related (p less than 0.05) to a maternal blood glucose level greater than 120 mg/dl, to a glucose infusion rate of 20 g/hr or greater and to an umbilical venous insulin level of greater than 40 microunits/ml. There were no major differences in neurobehavior that distinguished hypoglycemic neonates. It is recommended that the normal parturient be given less than 20 g/hr of intravenous glucose before delivery and have a blood glucose level less than 120 mg/dl at the time of delivery. Newborns delivered to mothers with hyperglycemia or excessive glucose infusion should be tested for hypoglycemia at 1 and 2 hours of age.

Behavior↗
PubMed1981

The pattern of eosinophilia in premature infants. A prospective study in premature infants using the absolute eosinophil count.

The incidence and severity of eosinophilia was prospectively studied in 45 premature infants, who were divided into three groups according to their gestational age. The incidence and severity of eosinophilia was higher in small preterm infants. A significantly higher number of infants with eosinophilia received total parenteral nutrition, endotracheal intubation, or blood transfusions. The duration of total parenteral nutrition or endotracheal intubation and the number of blood transfusions were also significantly higher in infants with eosinophilia. Eosinophilia in premature infants is not associated with neutropenia.

Birth Weight↗
PubMed1981

Postheparin lipolytic activity and Intralipid clearance in very low-birth-weight infants.

The effect of heparin (10 U/kg) on serum lipolytic activity, triglyceride and FFA levels, during four hours infusion of 0.5 gm/kg Intralipid was measured in 18 AGA infants, 25 to 32 weeks' gestational age. PHLA, TG, and FFA were measured at 0, 10, 30, 120, and 240 minutes of infusion of Intralipid, before and following a bolus of 10 U/kg heparin iv. Lipolytic activity, measured by hydrolysis of activated tri-3H-oleate and expressed in mumol FFA released per milliliter serum per hour, was not detected in serum before heparin administration. Ten minutes after heparin administration peak PHLA was significantly higher in infants of 27 to 32 weeks' gestation than in infants of 25 to 26 weeks' gestation. There was no significant difference in peak PHLA between infants of 27 to 28 and 29 to 32 weeks' gestation. PHLA returned to baseline (zero) two hours after heparin administration in all infants. Infants of 25 to 26 weeks' gestational age had significantly higher concentrations of serum triglycerides before and during Intralipid infusion than in infants of 27 to 32 weeks' gestational age. Although there was a transient rise in FFA 10 and 30 minutes after heparin administration, the levels of FFA and triglycerides were not different at the end of infusion with or without heparin in either group, suggesting that a single bolus of heparin has only a transient effect on Intralipid clearance.

Fatty Acids, Nonesterified↗
PubMed1981

Fat digestion in the newborn. Characterization of lipase in gastric aspirates of premature and term infants.

We have measured lipolytic activity in gastric aspirates obtained at birth in a group of 142 infants. The infants ranged in gestational age from 26 to 41 wk. Lipolytic activity, measured by the hydrolysis of long chain triglyceride ([tri-(3)H]oleate), and expressed as nanomoles FFA per milliliter gastric aspirate per minute was 333+/-66 in 55 small premature infants (gestational age 26-34 wk and body wt 750-2,000 g) and 558+/-45 in a group of 87 larger infants (gestational age 35-41 wk and body wt 2,020-4,000 g). No activity was detected in seven infants with an unusually low pH in the gastric aspirate, 2.88+/-0.44 (compared with a mean pH level of 5.59+/-0.22 in the other 135 infants). Attempts to characterize this lipase showed that it has a molecular weight of 44-48,000, pH optimum of 3.0-5.0, that FFA acceptors (albumin) stimulate activity, whereas bile salts, taurocholate and glycocholate, cause marked inhibition at concentration >3 mM. Our survey shows that enzyme activity is present as early as 26 wk of gestation, increases with gestational age, and has the same characteristics throughout gestation. The data show that the lipase in gastric aspirates differs from pancreatic lipase, but closely resembles human and rat lingual lipase. Because the lipase has a low pH optimum and does not require bile salts, it can act in the stomach where it initiates the hydrolysis of dietary fat. We suggest that intragastric lipolysis is probably of major importance in the newborn and especially in the premature infant where it compensates not only for low pancreatic lipase, but in addition, helps to overcome the temporary bile salt deficiency through the formation of amphiphilic reaction products.

Dietary Fats↗
PubMed1981

Fat digestion in very low-birth-weight infants: effect of addition of human milk to low-birth-weight formula.

The possible compensatory role of human milk lipase in the digestion of dietary fat was examined in a group of very low-birth-weight infants. Fat excretion was studied in 15 preterm infants of gestational age 26 to 33 weeks and birth weight 660 to 1,695 gm. The amount and composition of fecal fat were determined in stools collected for 72 hours. Eight infants were fed Similac 24 LBW exclusively and seven infants were fed a mixture of fresh human milk (40%) and formula (60%). Fat excretion was lower in infants fed a mixture of human milk and formula than in infants fed formula only (4.7% -+/- 0.50% vs 11.9% +/- 1.4% of intake, respectively). Excretion of calcium soaps, when expressed as percent of total fat, was higher in the group fed the human milk-containing diet (18.9% +/- 13.5%), than in the group fed formula only (6.8 +/- 2.5%); however, the absolute amounts excreted were similar in both groups (65 +/- 46 and 45 +/- 17 mg/kg/day, respectively). The lower fat excretion in infants fed a mixture of fresh human milk and formula could be related to the lipase present in human milk. These data suggest that human milk lipase probably contributes to the digestion and absorption of dietary fat in the "tiny premature" infant.

Dietary Fats↗