Margaret L. Williams

Role of Dietary Iron and Fat on Vitamin E Deficiency Anemia of Infancy

Thirty-five infants weighing less than 1500 g at birth were fed four commercial formulas (A-D) varying in polyunsaturated fatty acid composition (32 per cent linoleic acid in A and B and 12 per cent linoleic acid in C and D) and in iron content (smaller than 1.0 in A and B; 12 to 12 mg per liter in B and D). Infants receiving formula B showed significantly lower hemoglobins (p smaller than 0.01) and higher reticulocyte counts (p smaller than 0.005) than infants fed the other three formulas. Infants receiving the two formulas with higher concentrations of unsaturated fatty acids (A and B) showed significantly greater hydrogen-peroxide-induced hemolysis (p smaller than 0.001) than those given diets containing lower amounts. Infants in groups A and B also had lower serum tocopherol concentrations. Infant red-cell membranes are altered by the increased amounts of polyunsaturated fatty acids and iron in the diet. It appears that the development of vitamin E deficiency anemia occurs in infants receiving iron supplementation.

EXPRESSION OF N-METHYL-D-ASPARTATE (NMDA) AND NON-NMDA GLUTAMATE RECEPTOR GENES IN NEUROBLASTOMA, MEDULLOBLASTOMA, AND OTHER CELL LINES

We evaluated expression of N‐methyl‐D‐aspartate (NMDA) and non‐NMDA glutamate receptor (GluR) genes by reverse transcriptase‐polymerase chain reaction (RT‐PCR) and Southern blotting in nine established cell lines: rat CG‐4 (oligodendroglial lineage) and RINm5F insulinoma cells; human CHP134, SMS‐KCNR, SKNSH, and Nb69 neuroblastoma cells; and human D384Med, D425Med, and D458Med medulloblastoma cells. CG‐4 expressed mRNAs encoding GluR2–7, KA‐1, and KA‐2 non‐NMDA GluR (Yoshioka et al.: J Neurochem 64:2442–2448, 1995) and NR1 (NMDAR1) and NR2D NMDA GluR. After differentiation to oligodendrocyte‐like cells, CG‐4 also expressed NR2B mRNA. Rat insulinoma cells expressed GluR5, and KA‐2 non‐NMDA and NR1 and NR2D NMDA GluR mRNAs. The four human neuroblastoma lines all expressed mRNAs encoding GluR2–4, 6, 7 and KA‐1 non‐NMDA and NR1 NMDA GluR, and the three human medulloblastoma cell lines all expressed mRNAs encoding GluR1, 6 and KA‐1, but none of the NMDA GluRs. Whereas CG‐4 is susceptible to kainate excitotoxicity, treatment of insulinoma, neuroblastoma, and medulloblastoma lines with L‐glutamate, kainate, α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionate (AMPA), or NMDA failed to cause cell damage or to augment 45Ca2+ influx. Thus, despite expressing a variety of non‐NMDA and NMDA GluR genes, the human neuroblastoma and medulloblastoma and rat insulinoma lines failed to assemble Ca2+‐permeable NMDA or non‐NMDA GluR channels. This failure confers protection against excitotoxicity and may contribute to progression of tumors of these types.

Expression of Non-NMDA Glutamate Receptor Channel Genes by Clonal Human Neurons

Abstract: Treatment of the human teratocarcinoma line NTera2/c1.D1 (NT2) with retinoic acid induces terminal neuronal differentiation. In a previous study, we found that the neurons obtained in this way express functional N‐methyl‐d‐aspartate (NMDA) and non‐NMDA glutamate receptor channels. We now show by reverse transcriptase‐polymerase chain reaction and Southern blotting that these neurons transcribe each of the nine known non‐NMDA glutamate receptor genes (GluR1‐7, Ka‐1, and Ka‐2) and that four of these genes (GluR2, GluR6, GluR7, and Ka‐1) are also transcribed by undifferentiated NT2 cells. Patch clamp studies demonstrate that individual non‐NMDA glutamate receptor channels are readily isolated from NT2‐derived neurons and that these channels are potently modulated by the desensitization blocker cyclothiazide. NT2‐derived neurons are susceptible to kainate excitotoxicity but are not injured by prolonged exposure to α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionate. We expect that the NT2‐derived human neuronal culture system will facilitate studies of human neuronal non‐NMDA glutamate receptor channels and of the pathophysiology of neuronal excitotoxicity.

The response of blood glucose, ketones, and plasma nonesterified fatty acids to fasting and epinephrine injection in infants and children

Summary 1. Blood ketone, blood glucose, and plasma NEFA concentrations after a 24 hour fast were studied in 181 infants and children from birth to 12 years of age. 2. The same measurements following epinephrine injections were made in 89 infants and children from birth to 14 years. 3. It was found that infants under 36 hours were more resistant to ketosis on fasting than infants 2 to 6 days of age whose ketosis became almost as severe as that of subjects aged 1 week to 4 years. The difference in response between these two newborn groups was found to be associated with large stores of liver glycogen in the younger group. Infants under 36 hours did not appear to have any impairment of fat catabolism as indicated by a progressive rise in blood ketone levels on more extended fasts and by their normal NEFA elevation after epinephrine. 4. Subjects 1 week to 4 years of age developed more ketosis on fasting than did older children. It was shown that this was not related to differences in excretion or utilization of ketone bodies, indicating that variation in ketone production was the factor responsible. 5. Blood sugar levels below 40 mg. per cent occurred in 45 of 123 subjects under 6 months of age who were fasted for 24 hours. With one exception, blood sugar below this level was not found in subjects over 7 months of age.

NEURODEVELOPMENTAL OUTCOME OF PRESCHOOL CHILDREN BORN PRETERM WITH AND WITHOUT INTRACRANIAL HEMORRHAGE

Thirty‐five children who had been born preterm with and without intracranial hemorrhage and weighing ≤1500g were followed prospectively to assess neurodevelopmental outcome. The 13 children with hemorrhage were inferior to the 22 without hemorrhage in terms of birthweight, Apgar scores, health complications at and after birth, neurological integrity at age five and several scales of the McCarthy Scales of Childrens Abilities. The hemorrhage group performed significantly below the standardized mean on each of the McCarthy scales, whereas the group without hemorrhage performed below the mean only in Quantitative and Memory scores. The Bayley scales at one year were not clinically sensitive to hemorrhage, but were predictive of McCarthy General Cognitive Index scores at age five. A greater proportion of children with hemorrhage have had educational difficulties and have been included in alternative school programs. Preterm, very low‐birthweight children, and particularly those with intracranial hemorrhage, are at high risk for motor, perceptual and cognitive defects which underlie learning difficulties.

Fatty acid, amino acid, and trace mineral analyses of five weaning foods from Jos, Nigeria

Five plant-based weaning foods (WF) (Dietrend, Jot-M, Soy, Ang and Vic-T) locallyprepared in Jos, Nigeria were analyzed by gas-liquid chromatography,reverse-phase high performance liquid chromatography, and atomicemission spectrometry with inductively coupled plasma to determine theirfatty acid (FA), amino acid, and trace mineral contents, respectively.Results of these direct analyses were compared to expected values derivedfrom food composition tables prepared by the United States Department of Agriculture (USDA). Additionally, results were compared against recommendednutrient values, using breast milk as the standard for FA content andrecommended dietary allowances (RDA) for amino acid and mineral contents.The overall nutritional value of the five WF varied considerably and thequantities of particular nutrients determined by direct analysis differedmarkedly from those estimated using USDA food tables. Comparison of WFfatty acid composition relative to the RDA recommendations and a humanmilk standard revealed a much higher proportion of both linoleic (35–55wt%) and α-linolenic acids (1%–7 wt%) relative to human milklipids (11%–12% and 0.8%–0.9% wt, respectively); however, the WFwere devoid of arachidonic acid and docosahexaenoic acid. Soy containedthe highest amounts of linoleic acid (59.7 mg/g) and α-linolenicacid (7.46 mg/g) compared to the other four WF (10.2–41.0 and 0.35–3.18 mg/g, respectively). The linoleic acid/α-linolenic acid ratio was within the recommended range (5:1 to 10:1) in only Jot-M (10:1)and Soy (8:1). Dietrend, Vic-T and Ang, containedlinoleic/α-linolenic ratios of 12:1, 29:1, and 82:1, respectively.The Soy weaning food would provide the most protein (24.3 g/day), basedon an estimated daily intake of 65 g of weaning food by a normalsix-month-old infant, compared to Jot-M (11.9 g/day), Dietrend (11.7g/day), Ang (8.07 g/day) and Vic-T (7.26 g/day). The protein RDA forchildren up to 1 year of age is 13–14 g/day. Comparison of the mineralcontents of the WF to the RDAs for various minerals indicated that all fivewould provide suboptimal amounts of calcium (16 to 250 mg/day) andzinc (1.42 to 3.56 mg/day) compared to respective RDAs of400 mg/day and 5 mg/day.These data show that the Soy weaning food is an excellent source of linoleicacid and α-linolenic acid, as well as being a good source of highquality protein. Jot-M and Dietrend provide useful amounts of the essentialFA; however, it is advisable to reevaluate the composition of Ang andVic-T to find ways to improve the linoleic/α-linolenic ratio of eachand increase their total protein content. These results document theshortcomings of using published food composition tables based on foods inAmerica when devising weaning foods based on ingredients in another partof the world.

Group A beta hemolytic streptococcal sepsis in mother and infant twins.

Twin pregnancy was diagnosed at 32 weeks of gestation in an apparently healthy woman. Heavy leukorrhea at 35 weeks was followed one week later by delivery of apparently healthy neonates (2,155-gm girl and 2,600-gm boy) after a 4 89 labor initiated by spontaneous rupture of membranes. The subsequent course of the two infants was similar. Initial stability was followed within several hours by sudden onset of progressive respiratory distress. Initial chest roentgenogram in one infant was normal and in the sibling showed a few streak-like densities and fluid in a fissure. Repeat roentgenograms within several hours revealed large areas of the lungs to be opacified in both infants. Each of the infants had a leukopenia (1,100 and 1,500 white blood cells/mm0 and neutropenia (6% and 2%, respectively). Clinical evidence of pulmonary hemorrhage was followed shortly thereafter by circulatory collapse and death at 21 and 29 hours of age, respectively. Sepsis had been suspected and antibiotic therapy begun late in the clinical course. Postmortem examination of each infant revealed bilateral pneumonia, pulmonary hemorrhage, and bilateral adrenal hemorrhage. Eighteen hours after delivery the mother became febrile; subsequent examination and clinical course werecompatible with pelvic thrombophlebitis; this patient survived. Group A beta hemolytic streptococci (type 12) were isolated from premortem blood cultures of both infants, from a suprapubic urine culture of one infant, and from blood and lochia of the mother.

Acetylcholine in the treatment of idiopathic respiratory distress syndrome

Summary This report involved 7 infants with IRDS who were treated with acetylcholine. In 3 of them the drug was infused directly into the pulmonary artery, and a temporary rise in PaO2 was accompanied by fall in pulmonary artery pressure and partial correction of acidosis. However, both pressure and blood-gas tensions reverted to original levels during the course of the infusion, and no lasting beneficial effect was evident.

1135 EFFECT OF POSITIONING AND HEAD BANDING ON INTRACRANIAL PRESSURE IN THE PREMATURE INFANT

The intracranial pressure of 12 infants, birthweight 720-1800 gms., who had no evidence of intracranial hemorrhage, was measured over the anterior fontanelle by the Ladd ICP monitor. Pressures were determined before and one minute after the release of encircling phototherapy eye patches or nasal cannula apparatus. The measurements were performed twice on each infant in three different positions -- head up 30°, horizontal, and head down 30°. A significant decrease in pressure was noted immediately after release of the encircling band in all three positions in most infants. The average decrease was 3.75 (range 0-14.5), 3.73 (range 0-10), and 3.45 (range 0-9) cm H2O in the head up, horizontal, and head down position respectively. Three of the four infants who demonstrated the smallest decrease in intracranial pressure had been exposed to constricting apparatus for long periods of time prior to their determinations suggesting possible compensation. The magnitude of the decrease in pressure was not different in the various positions studied, although the pressures tended to increase as the infant was placed in the head down position. The changes noted in intracranial pressure both with positioning and banding raise questions as to the effect of such infant care practices on the brain of infants with compressible skulls. Increases in intracranial pressure induced by head banding may play a role in the high incidence of intracranial hemorrhage in the very small infant.

Water content and metabolic activity of mitochondria from fetal rat liver.

Summary 1. Mitochondria prepared from fetal rat liver show marked spontaneous swelling in KCl-Tris suspension but not in sucrose. This spontaneous swelling is inhibited by the use of EDTA in the preparation medium. 2. Fetal mitochondria swell much less in the presence of phosphate, thyroxine and calcium than do adult mitochondria but response to oxidized plus reduced glutathione is similar in fetal and adult preparations. Swollen fetal mitochondria contract well upon addition of ATP and magnesium except in the presence of phosphate. 3. Mitochondria from fetal liver oxidize succinate and glutamate-malate at rates equal to or higher than those of adult mitochondria. They are capable of carrying out active oxidative phosphorylation with good respiratory control. 4. Fetal mitochondria show marked lipid peroxidation on incubation without exogenous substrate. This peroxidation is inhibited by vitamin E.