Management of hydrocephalus secondary to intracranial hemorrhage in the high risk newborn

The experience of the Special Care Nursery of the University of California Medical Center, San Diego, in the management of the high risk newborn with progressive ventricular enlargement is reviewed, and the physiopathological basis of progressive ventricular enlargement is analyzed.

Elastase and alpha 1-proteinase inhibitor activity in tracheal aspirates during respiratory distress syndrome. Role of inflammation in the pathogenesis of bronchopulmonary dysplasia

Pulmonary effluent samples were obtained from 26 preterm or term infants throughout the period of endotracheal intubation. Infants with respiratory distress syndrome, infants with this disorder developing bronchopulmonary dysplasia, and intubated infants without lung disease were compared daily in terms of lung effluent cellularity, albumin, elastase activity, alpha 1-proteinase content and activity, and elastase inhibitory capacity. The elastase activity was determined to be neutrophilic in origin. Polyacrylamide gel electrophoresis of pulmonary effluents from two infants with respiratory distress syndrome and exposed to FiO2 greater than or equal to 0.6 up to 6 d revealed cleavage of alpha 1-proteinase inhibitor to a 47,000-mol weight fragment suggestive of oxidation. Pulmonary effluent neutrophils, macrophages, and elastase activity were increased by day 3 of life in infants with respiratory distress syndrome eventually developing bronchopulmonary dysplasia. Elastase inhibitory capacity and alpha 1-proteinase inhibitor activity were reduced in infants developing chronic lung disease. Bronchopulmonary dysplasia developed in infants with enhanced inflammatory response, but with less or inhibited antiprotease activity.

Increased hypoxanthine concentrations in cerebrospinal fluid of infants with hydrocephalus

Hypoxanthine, the end product of purine metabolism, is usually very elevated in body fluids during severe hypoxia. We measured hypoxanthine in the cerebrospinal fluid of hydrocephalic preterm infants (12 with posthemorrhagic, one with congenital hydrocephalus) to determine whether hydrocephalus is associated with anaerobic metabolism of brain tissue. Cerebrospinal fluid hypoxanthine was undetectable in normal infants. In hydrocephalic infants, the concentration of hypoxanthine ranged from 7.5 mumol/L to 28 mumol (means = 14.3 mumol/L). The hypoxanthine concentrations fell from a mean of 12.8 mumol/L to a mean of 2.0 mumol/L (P less than 0.05) with successful treatment of the ventriculomegaly by lumbar puncture or by ventriculoperitoneal shunt. Patients with acute posthemorrhagic hydrocephalus had similar concentrations of hypoxanthine (means = 14.5 mumol/L) as patients with late or with congenital hydrocephalus (means = 13.8 mumol/L), indicating that brain hypoxia is probably a consequence of the ventriculomegaly and not of the hemorrhagic insult.

Evidence of lung surfactant abnormality in respiratory failure. Study of bronchoalveolar lavage phospholipids, surface activity, phospholipase activity, and plasma myoinositol

Autopsy findings suggest that lung surfactant is damaged in the adult respiratory distress syndrome. In the present study 225 bronchoalveolar lavage specimens (78 from 36 patients, 1-78 yr old with respiratory failure, 135 from another 128 patients with other respiratory disease, and 12 from healthy controls) were assayed for the lung profile [lecithin/sphingomyelin (L/S) ratio, saturated lecithin, phosphatidylinositol, and phosphatidylglycerol]. Bronchoalveolar lavage fluid was further analyzed for phospholipids and for phosphatidic acid phosphohydrolase, phospholipase A2, and phosphatidylinositol phosphodiesterase activities. A lipid-protein complex was isolated and analyzed for surface activity, and plasma was measured for myoinositol. There were only small differences seen in the recovery of total phospholipid between respiratory failure patients and normal controls. However, in respiratory failure, phospholipids in bronchoalveolar lavage were qualitatively different from those recovered either from normal controls or from patients with other lung disease: the LO/S ratio, phosphatidylglycerol, and disaturated lecithin were low, whereas sphingomyelin and phosphatidylserine were prominent. These abnormalities were present early in respiratory failure and tended to normalize during recovery. Low L/S ratio (less than 2), and low phosphatidylglycerol (1% or less of glycerophospholipids) in bronchoalveolar lavage was always associated with respiratory failure. Abnormal lavage phospholipids were not due to plasma contamination. The phospholipase studies revealed little evidence of increased catabolism of phospholipids. In respiratory failure, the lipid-protein complexes from lung lavage were not surface active, whereas that from healthy controls had surface properties similar to lung surfactant. Phospholipids from patients with respiratory failure were similar to those from respiratory distress syndrome in the newborn. However, the latter condition is characterized by fast recovery of surfactant deficiency and by high plasma myoinositol that suppresses the synthesis of surfactant phosphatidylglycerol and increases phosphatidylinositol (Pediatr. Res. 1981. 15: 720). On the other hand, in adult respiratory distress syndrome, the abnormality in surfactant phospholipids may last for weeks and in most cases is associated with low phosphatidylinositol, low phosphatidylglycerol, and low plasma myoinositol.

Preschool assessment of infants with a patent ductus arteriosus: comparison of ligation and indomethacin therapy

We report the preschool growth and development of preterm infants with problematic patent ductus artferiosus requiring either surgical ligation or indomethacinn treatment in the neonatal period. Of 60 who completed longitudinal growth assessments, no differences in growth to 3 years could be demonstrated except for four cases of regressed retinopathy of prematurity among the ligated infants. Developmental tests (Bayley Scales of Infant Development and the Peabody Picture Vocabulary Test) showed no group differences at preschool ages. Although psychomotor performance on the Bayley Scales in the first 1 1/2 years was significantly lower among the surgically treated infants, later analysis showed that a similar number in both treatment groups scored within the normal range. No selective short- or long-term adverse effects of indomethacin treatment could be demonstrated.

Effects of maternal insulin or glucose infusion on the fetus: study on lung surfactant phospholipids, plasma myoinositol, and fetal growth in the rabbit

Pregnant rabbits were given continuous intravenous insulin between days 26.7 and 28.7 after conception. The treatment decreased fetal serum glucose, insulin, and myoinositol. Furthermore, maternal insulin decreased fetal growth slightly, and improved the survival of the prematurely delivered fetuses. Analysis of phospholipids recovered by alveolar lavage revealed that the lung surfactant was quantitatively and qualitatively superior to the surfactant from the fetuses of the saline-glucose control animals. This effect on the lung was more striking than that of glucocorticoid. Another group of pregnant rabbits received continuous intravenous glucose between days 27.0 and 29.0 after conception. The hyperinsulinemic fetuses of the glucose-infused does weighed more and had higher serum glucose and myoinositol than did those of the control animals. There was no detectable difference in alveolar lavage phospholipids between hyperinsulinemic and normoinsulinemic fetuses of glucose-infused does. The possible importance of these findings in understanding the mechanism of acceleration of lung maturation is discussed.

The cardiovascular effects of dopamine in the severely asphyxiated neonate

The cardiovascular effects of dopamine were evaluated in 14 severely asphyxiated neonates. After a period of stabilization, either dopamine 2.5 micrograms/kg/minute or placebo was infused in a randomized double-blind protocol. In seven dopamine-treated infants, echocardiographically determined shortening fraction and mean velocity of circumferential fiber shortening increased when compared to preinfusion values (P less than 0.05). There was no significant change in these echo indices of cardiac function in the placebo-treated group. Systolic blood pressure rose in the dopamine group when compared to predopamine infusion values and to the postinfusion values of the placebo group (P less than 0.001 and 0.025, respectively). Diastolic blood pressure increased to a small degree in the dopamine group. There was no significant change in heart rate or echocardiographically measured systolic time intervals. Low doses of dopamine increase cardiac performance and raise systolic blood pressure in the severely asphyxiated neonate.

Analysis of labeling and clearance of lung surfactant phospholipids in rabbit. Evidence of bidirectional surfactant flux between lamellar bodies and alveolar lavage

Turnover and clearance of lung surfactant phospholipids were studied with particular reference to myoinositol-induced perturbation in the acidic phospholipids. Administration of myoinositol decreased [(3)H]palmitate and [(32)P]phosphate incorporation into phosphatidylglycerol by 80-90% in whole lung, and by 94-99% in lamellar bodies and in alveolar lavage. The increased incorporation of radioactive isotopes into phosphatidylinositol following myoinositol, was inverse to the decrease in phosphatidyl-glycerol incorporation. Myoinositol treatment affected neither content nor labeling of phosphatidylcholine or disaturated phosphatidylcholine as studied within 50 h of administration. Phosphatidylglycerol was pulse labeled by intravenous [(32)P]phosphate and [(3)H]palmitate, followed by myoinositol. The biological half-lives of phosphatidylglycerol in the microsomal fraction, lamellar bodies, and alveolar lavage were 1.6, 4.6, 5.4 h (with (3)H), and 2.8, 6.5, 7.0 h (with (32)P), respectively.(32)P-labeled lung surfactant tracer was applied to the airways in saline suspension and the clearance of phospholipid radioactivity was measured in alveolar lavage, alveolar macrophages, lamellar bodies and lung homogenates. The clearance rates of phosphatidylcholine, disaturated phosphatidylcholine, phosphatidylglycerol, and phosphatidylinositol as studied in whole lung over 6 h were 3.4-5.8% h. Only a small amount of phospholipid radioactivity was recovered in the alveolar macrophage fraction (including bis-[monoacylglycerol]phosphate). Phospholipid radioactivity in alveolar lavage fell to 40-70% of the maximum during the 1st h, and to 5-18% over the next 6 h. During 2 h after the application of phospholipids, the radioactivity in the lamellar body fraction increased, and the specific radioactivities approached those in alveolar lavage. The association of phosphatidylglycerol with lamellar bodies was unaffected by myoinositol. Phosphatidylinositol entered more slowly than did phosphatidylglycerol from microsomes to the alveolar lavage fraction, and from alveolar lavage to lamellar bodies. These differences may be of importance regarding the poor performance of phosphatidylinositol-containing surfactant at birth. Further investigations are needed to clarify the possible role for the postulated bidirectional surfactant flux between the lamellar body and alveolar lavage fractions in maintaining the activity of surfactant.

Tc-99m HIDA scintigraphy in segmental biliary obstruction

Segmental biliary obstruction as a result of primary or secondary hepatic malignancy has been reported with increasing frequency. For two representative patients, the clinical and Tc-99m HIDA scintigraphic findings in segmental biliary obstruction are described. The presence of photon-deficient dilated bile ducts in one segment of the biliary tree is highly suggestive of localized biliary obstruction and should be considered in the patient with suspected or proven hepatic malignancy despite the absence of jaundice.

Premature labor. II. Bacterial sources of phospholipase

Human term labor is thought to be initiated by amniotic and chorionic phospholipase A2, an enzyme that liberates arachidonic acid esters from the phospholipids of these membranes, leading to the synthesis of prostaglandins by the placental membranes. The striking association of premature labor with intrauterine infection or contamination, urinary tract infection, and early neonatal sepsis led us to study the microorganisms present in these infections for phospholipase A2 activity. Activity was found in Bacteroides fragilis, Peptostreptococcus, Fusobacterium necrophorum, Streptococcus viridans, Streptococcus fecalis, Streptococcus A and B, Escherichia coli, Klebsiella, Staphylococcus epidermidis, Pneumococcus, Lactobacillus, and Mycoplasma hominis. Bacteroides fragilis, Peptostreptococcus, Fusobacterium, and S viridans had the highest activities. The specific activities of phospholipase A2 from these organisms were several times higher than that of the membrane phospholipase A2 of the amnion and chorion. We postulate that premature labor may be initiated by microorganisms with phospholipase A2 activity from endocervical and/or intrauterine contamination or infection, producing deacylation of arachidonic acid from amniotic phospholipids with increased concentrations of free arachidonic acid and increased prostaglandin synthesis, which triggers labor.

Premature labor. I. Prostaglandin precursors in human placental membranes

Amnion and chorion from premature and term placentas after both spontaneous labor and elective cesarean section were assayed for phospholipids and fatty acid composition by 2-dimensional thin-layer chromatography and gas-liquid chromatography. In preterm placental phospholipids, phosphorus concentrations were higher in amnion than in chorion, whereas at term the membranes were similar owing to an increase in phospholipid concentration in the chorion late in gestation. PHosphatidylcholine (PC) accounted for 47% of the total phospholipid phosphorus, followed by sphingomyelin at 20%, phosphatidylethanolamine (PE) at 15%, phosphatidylserine (PS) at 12%, and phosphatidylinositol (PI) at 5%. These percentages were similar for amnion and chorion and they did not change during gestation. The percentage of arachidonic acid (AA) was higher in PS (40 to 65%) than in PE (30 to 53%) and PC (10 to 13%). The percentage of AA was significantly higher in PC, PE, and PS from the amnion in premature pregnancies than in those of the premature chorion. At term, these amnionic and chorionic phospholipids had similar concentrations of AA owing to a significant increase in AA in the chorion late in gestation. Amnionic PE from term and preterm elective cesarean section had a significantly higher percentage of AA than that from preterm and term labor. These data suggest that AA is consumed during labor and that amnionic phospholipids, particularly PE, may be its principal source. The amnion seems to be more important for the storage of AA than the chorion, particularly in preterm pregnancies in which the concentrations of phospholipids and the percentages of AA in PC, PE, and PS were significantly higher than in the chorion.

Changes in the lecithin:sphingomyelin ratio during labor and the associated fetal heart rate patterns

Serial samples of amniotic fluid were taken from 38 patients in spontaneous labor and the lecithin:sphingomyelin (L:S) ratios were estimated. The fetal heart rate (FHR) pattern for each patient was analyzed, and the baseline rate, long-term variability, and periodic changes wee determined. It was found that changes in the L:S ratios were significantly correlated with the duration of labor and FHR long-term variability. Very low L:S ratios were observed in some patients whose infants did not subsequently develop respiratory distress syndrome. This raises the possibility that during labor the amniotic fluid is no longer representative of lung fluid, perhaps because of reduced tracheal fluid efflux, a process which may operate when the fetus is under stress.

Alterations in fetal lung phosphatidylinositol metabolism associated with maternal glucose intolerance

Prior to conception, female rabbits were made hyperglycemic by streptozotocin administration. Fetal hyperglycemia and hyperinsulinemia were documented. Although plasma myoinositol concentration were higher in the fetuses of diabetic mothers, the ratio of lung to plasma myoinositol concentrations in 29-day fetal rabbits were lower than control values. CDP-diglyceride:inositol phosphatidyltransferase was reduced by 70% in the diabetic fetuses and their lung tissue phosphatidylinositol content was decreased.

Diagnosis and follow-up of intraventricular and intracerebral hemorrhages by ultrasound studies of infant's brain through the fontanelles and sutures

A technique to diagnose subependymal hemorrhage (SEH), intraventricular hemorrhage (IVH), intracerebral hemorrhage, and posthemorrhage hydrocephalus in tiny infants, using real time ultrasound studies of the brain ventricular system, is described. This is a bedside technique that visualizes the brain through the fontanelles and the sutures, in three planes: coronal, sagittal, and horizontal. Excellent visualization of the ventricular system, caudate nuclei, the thalamus, the choroid plexus, the corpus callosum, and the foramen of Monro is obtained. This method has good definition using high frequency transducers since there is no bone interference. The ultrasound diagnosis correlated well with computed tomography (CT) and with direct pathologic studies. This technique was more sensitive in diagnosing small IVH/SEH and organized clots than were CT studies. IVH/SEH were found in 90% of 113 infants less than or equal to 34 weeks of gestation; 49% of the hemorrhages were large and 41% were small. Most hemorrhages were found in the first scan, usually shortly after birth. Twenty-one premature infants who never had perinatal asphyxia or respiratory distress syndrome had IVH/SEH. The hemorrhages were followed until disappearance, usually in one to three months in cases of large hemorrhages.