Immunologic study of the age-related loss of activity of six enzymes in the red cells from newborn infants and adults--evidence for a fetal type of erythrocyte phosphofructokinase.

Blood from 10 normal healthy adults and cord blood from 8 healthy full term infants were infiltrated through a mixture sulfoethylethycellulose-Sephadex G 25 in order to eliminate the platelets and the leukocytes. Then the erythrocytes were fractionated into young and old cells by centrifugation in microhematocrit tubes. The enzyme activity and the immunologic reactivity of glucose phosphate isomerase (EC.5.3.1.9), phosphoglycerate kinase (EC.2.7.2.3), pyruvate kinase (ec.2.7.1.40), glucose 6-phosphate dehydrogenase (EC. 1.1.1.49), and 6-phosphogluconate dehydrogenase (EC.1.1.1.44) were measured in every fraction. As previously reported, the enzyme activities were far higher in cord blood than in adult blood red cells; nevertheless, the age-related loss of enzyme activity was similar in both cord and adult blood. The decrease of the enzyme activity of glucose phosphate isomerase and phosphoglycerate kinase in old cells was singly associated with a lowered concentration of the enzyme-related antigen; by contrast, the age-related decrease of the enzyme activity of pyruvate kinase, glucose-6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase was associated with both a lowered concentration of the enzyme-related antigen and a lowered "molecular specific activity" (i.e., a lowered ratio of enzyme activity to enzyme-related antigen concentration). This phenomenon was especially marked for pyruvate kinase, which had a molecular specific activity in old cells that was 68% of that in young cells. Phosphofructokinase had a lower enzyme activity in cord blood erythrocytes than in adult blood erythrocytes; the difference was especially important in old cells from infants in which phosphofructokinase activity was 53% of that in old cells from adults. Phosphofructokinase from old cells of full term infants and from unfractionated cells from two premature infants (21 and 32 weeks of gestation) was less neutralized by anti-muscle phosphofructokinase serum and more inhibited by ATP than the enzyme from adult blood erythrocytes.     

In vivo lability of red cell phosphofructokinase in term infants: the possible molecular basis of the relative phosphofructokinase deficiency in neonatal red cells.

Cord blood erythrocytes from nine term infants were separated by density gradient centrifugation into cohorts of intact cells of progressively increasing density and compared with red cells treated in a similar manner from four healthy adults. Pyruvate kinase (PK), an age-dependent enzyme, progressively decreased in activity from the lightest to the heaviest fractions, in both neonatal and adult red cells, indicating that red cells from newborn infants exhibit the same relationship between red cell age and density that had previously been demonstrated in red cells from adults. The rate of decline of red cell PK activity was essentially the same in neonates and adults, whereas phosphofructokinase (PFK) activity in cord erythrocytes decreased at a significantly faster rate when compared to adults. These data suggest that PFK has an accelerated rate of in vivo decay in neonatal red cells and is an unstable enzyme in the newborn.     

Red cell enzymes and intermediates in AGA term newborns, AGA preterm newborns and SGA term newborns

Red cell enzyme activities and 2,3-diphosphoglycerate and adenosine-triphosphate levels in cord blood of three groups of newborn infants were studied. The groups were classified according to birthweight in relation to intrauterine growth and gestational age. Only phosphofructokinase, glyceraldehyde-3-phosphate dehydrogenase and enolase activity values differed significantly among the groups. The activity of phosphofructokinase was lower in small-for-date term infants (TSGA) and preterm adequate for gestational age (PTAGA) in comparison to term infants adequate for gestational age (TAGA). Glyceraldehyde-3-phosphate dehydrogenase activity was higher in TAGA, in comparison to PTAGA, with no other difference among the groups. Enolase activity was found to be higher in TSGA compared to TAGA and higher in PTAGA compared to TAGA. No differences were found between PTAGA and TSGA.     

Red Cell Enzymes and Intermediates in AGA Term Newborns, AGA Preterm Newborns and SGA Term Newborns

ABSTRACT. Red cell enzyme activities and 2,3-diphosphoglycerate and adenosine-triphosphate levels in cord blood of three groups of newborn infants were studied. The groups were classified according to birthweight in relation to intrauterine growth and gestational age. Only phos-phofructokinase, glyceraldehyde-3-phosphate dehydrogenase and enolase activity values differed significantly among the groups. The activity of phosphofructokinase was lower in small-for-date term infants (TSGA) and preterm adequate for gestational age (PTAGA) in comparison to term infants adequate for gestational age (TAGA). Glyceraldehyde-3-phosphate dehydrogenase activity was higher in TAGA, in comparison to PTAGA, with no other difference among the groups. Enolase activity was found to be higher in TSGA compared to TAGA and higher in PTAGA compared to TAGA. No differences were found between PTAGA and TSGA.     

Comparison of RNA and DNA synthesis,spontaneous and PHA induced,between blood lymphoid cells of newborn infants,older infants,and adults

Spontaneous and PHA induced RNA and DNA synthesis was measured qualitatively by autoradiography and quantitatively by scintillation counting in blood lymphoid cells of newborn infants, older infants, and adults. Spontaneous RNA synthesis was found in transitional cells, large phagocytic lymphoid cells and lymphocytes. Transitional cells and phagocytic lymphoid cells also synthesized DNA spontaneously. Quantitatively, spontaneous RNA synthesis was active in both newborn infants and in adults, but significantly less so in older infants. PHA stimulation for 18 h increased RNA synthesis significantly in blood lymphoid cells of newborn infants and adults, and to a much lesser but still significant degree in older infants. Spontaneous DNA synthesis was significantly greater in newborn infants than in older infants and adults. PHA stimulation for 18 h had no effect on thymidine incorporation in any of the groups studied.Supported by grant Pr 75/7 from the Deutsche Forschungsgemeinschaft     

Quantitation of T cells in venous blood of healthy neonates

Quantitation of T Cells in blood is the part of the diagnostic workup for cellular immunity. Specimens of venous blood were collected within 24 hours of birth from 51 healthy, appropriate for gestational age infants. T lymphocytes were identified on the basis of their ability to form rosettes with sheep erythrocytes. The lymphocytes were harvested from peripheral venous blood, which is considered to be more representative of the immune status in the newborn than the cord blood. In the newborn infants the proportion in T cells was found to be considerably diminished in comparison to previously reported values for adults. Preterm infants, especially those with gestational age of 34 wk or less had significantly lower percentage of T cells in their blood as compared with term infants. The proportion of T cells was statistically reduced in infants weighing 2000g or less in contrast to those weighing 2500 g or more.     

Acetylcholinesterase activity in the erythrocytes of newborn infants with hyperbilirubinemia and asphyxia.

The authors measured erythrocyte acetylcholinesterase (ACHE) activity in 51 physiologic newborn infants, 35 pregnant women and 101 infants with hyperbilirubinemia caused by hemolytic diseases in the ABO and Rh systems, or of other origin (6 children). In total, 374 examinations of erythrocyte ACHE were performed. The normal values of physiologic infants during the first hours of life were 0.162 +/- 0.03, at the age of 3 days 0.104 +/- 0.04. The values in pregnant women were 0.206 +/- 0.07. The ACHE activity was considerably decreased in newborn infants affected by erythroblastosis-ABO, and its mean value, in the case of exsanguinotransfusion indicated by the Polácek scheme, amounted to 0.060 +/- 0.051. It raised after exsanguinotransfusion and was equal to the value of red cells transfused. In newborn infants affected by erythroblastosis-Rh, the value decreased in the cases complicated with asphyxia. Low values of ACHE are sometimes found in certain cases of IRDS or of septicemia. The determination of erythrocyte ACHE activity enables assessing the state of red blood cells.     

Direct monitoring of arterial blood pressure in depressed and normal newborn infants during the first hour of life

Direct systolic, diastolic, and mean arterial blood pressure was continuously recorded during the first 64 min of life in 150 newborn infants. The data were analyzed at 4, 8, 16, 32, and 64 min. The highest blood pressure values were noted during the first few minutes of life in all newborn infants, with a rapid drop within 4 to 8 min. Decline in blood pressure was more gradual throughout the remainder of the observation period. Blood pressures of depressed newborn infants at birth (Apgar scores 6 or less at 1 and 5 min) were compared to those of normal newborn infants (Apgar scores 7 or greater at 1 and 5 min). The former demonstrated generally higher systolic pressures during the first 16 min and diastolic pressures at 4 min when infants were compared by their 1 min Apgar scores and higher diastolic pressures at 4 min when the infants were compared by their 5 min Apgar scores.     

Increased activity of the respiratory burst in cord blood neutrophils: kinetics of the NADPH oxidase enzyme system in subcellular fractions

Previous studies with neutrophils from newborn infants compared to neutrophils from healthy adults have documented increased respiratory burst activity including enhanced superoxide anion (O2-) production, nitroblue tetrazolium dye reduction, and hexose monophosphate shunt activity. To investigate the biochemical basis for these observations, we examined oxidative metabolism in membrane-rich fractions of neutrophils. Neutrophils from cord blood of vaginally delivered term infants or healthy adults were disrupted by nitrogen cavitation and subcellular fractions collected on discontinuous sucrose density gradients. Subcellular fractions of newborn neutrophils separated in a fashion identical with samples from healthy adults. Activity of alkaline phosphatase, a plasma membrane marker, was increased 4- to 5-fold in disrupted cells free from nuclei (postnuclear supernatant) as well as plasma membrane fractions from newborn samples compared to those from healthy adults. Content of lactoferrin, a specific granule marker, was decreased in postnuclear supernatants but equivalent in specific granule fractions of newborn cells compared to those from adults. No differences were noted in myeloperoxidase content of postnuclear supernatants or any other subcellular fraction. Plasma membrane fractions from phorbol myristate acetate-stimulated cord blood neutrophils made significantly more O2- than samples from adults (newborn 32.9 +/- 8.1 nmol O2-/min/mg protein mean +/- SEM, n = 3 versus adult 10.8 +/- 4.2, n = 3; p less than 0.05). Plasma membrane-rich fractions were also collected by the technique of differential centrifugation and kinetic parameters of the NADPH-dependent oxidase enzyme(s) were measured for vaginally delivered newborn and adult samples.(ABSTRACT TRUNCATED AT 250 WORDS)     

Spontaneous DNA synthesis of blood lymphoid cells in premature newborn infants,in older premature infants and in full-term newborn infants

In adults, blood cells which synthesize DNA spontaneously are large, pale lymphoid phagocytes. In fetal blood, transitional cells label spontaneously in addition to the lymphoid phagocytes (Prindull et al., 1975a, b). In the present study, we have measured quantitatively by scintillation counting, spontaneous thymidine incorporation of blood cells from different groups of infants.When compared with the conditions in the normal adult, spontaneous DNA synthesis of peripheral blood lymphoid cells is increased by a factor of 16.4 in premature newborn infants (P<0.002), by a factor of 8.7 in full-term newborn infants (P<0.01), and in older premature infants studied at the time of their calculated birth dates by a factor of 4.3 (P<0.001).Spontaneously labelling blood cells most likely are, at least in part, hematopoietic stem cells from the bone marrow.With technical assistance of Brigitte Prindull.     

SYSTOLIC TIME INTERVALS IN NEWBORN INFANTS

ABSTRACT: Hedvall, G. (Department of Paediatrics I, Östra sjukhuset, University of Göteborg, Göteborg, Sweden). Systolic time intervals in newborn infants. Acta Paediatr Scand, 64: 839, 1975.–Systolic time intervals, calculated from the carotid artery pulse curve have been used for some time to assess left ventricular performance. Normal values have been established for adults and older children, but few investigations have been made on newborn infants, generally with partly contradictory results. Therefore a study has been undertaken in 29 normal newborn infants ½-119 hours old, and 9 infants 2–3 months old to establish normal values for the different intervals. They were found to differ from those reported for adults and older children, most clearly seen in the relatively long preejection period (PEP). Statistically significant differences were found between the PEP of 20 infants below 47 hours of age and 9 infants 2–3 months old: PEP 82 ms and 68 ms respectively. ( P < 0.01); the same is true of the quotient PEP/LVET (left ventricular ejection time), which was found to be 0.41 and 0.35 resp. ( p < 0.01). By adult standards this would mean impairment of left ventricular function. A possible explanation of this could be a difficulty for the left ventricle to cope with the systemic circulation during the first days of life even in normal newborns, a difficulty not fully compensated for even at 3 months of age.     

Antibody-Dependent Cellular Cytotoxicity and Natural Killer Activity Against HTLV-1 Infected Cells

Antibody-dependent cellular cytotoxicity (ADCC) and natural killer (NK) ativity were examined using MT-2 cells persistently infected by HTLV-1 as target cells, and mononuclear cells as effector cells, from helathy one-week-old newborn babies, infants, children and adults. More than 10% of ADCC was observed in 17 newborn babies out of 22 (77.3%) and in all 67 healthy one-month-old babies to adults, by adding serum from anti-HTLV-1 positive carriers. When anti-HTLV-1 negative serum was added, less than 10% of ADCC was observed. If infants without anti-HTLV-1 antibodies were breast-fed they had the possibility of HTLV-1 vertical transmission. There was no significant decrease in NK activity between 90 healthy newborn babies, infants, children, or adults. These results suggest that ADCC and NK activity protect against the transmission of HTLV-1 from mother to child.     

Effect of lipid emulsion on IL-2 production by mononuclear cells of newborn infants and adults

The in vitro effect of a lipid emulsion (intralipid) on interleukin-2 (IL-2) production by cord blood mononuclear cells (CBMC) of preterm and term newborn infants was examined and compared to that of peripheral blood mononuclear cells (PBMC) of adults. Intralipid, added at concentrations accepted in clinical practice, caused a dose-dependent inhibition of IL-2 activity tested by bioassay. IL-2 levels, tested by radioimmunoassay (RIA), were found to be reduced only in supernatants derived from CBMC of term infants and not in those derived from MC of preterm infants or adults. The capacity of the IL-2 dependent cell line CTLL-2 to respond to IL-2 was abolished in the presence of intralipid, suggesting an interference with the binding of IL-2 to its receptor on these cells. It is conceivable that administration of intralipid to preterm infants may interfere with the binding of IL-2 to the specific receptors on their activated lymphocytes, with a possible subsequent suppression of their immune response.     

BLOOD VISCOSITY AND PERIPHERAL CIRCULATION IN NEWBORN INFANTS: A Study on Resting Flow

ABSTRACT. Bergqvist, G. and Zetterström, R. (Department of Paediatrics, Karolinska Institutet, St Göran's Hospital for Children, Stockholm, Sweden). Blood viscosity and peripheral circulation in newborn infants. A study on resting flow. Acta Paediat Scand, 63: 865, 1974.—Whole blood viscosity, hernatocrit and peripheral resting flow have been measured in 18 one to three days old newborn infants. There was no correlation between viscosity and blood flow or between viscosity and peripheral resistance. In seven infants isovolemic hernodilution was performed. This procedure did not alter the resting blood flow.     

"Pseudoleukemia" in a newborn infant with trisomy 21]

The increased incidence of leukemia in patients with trisomy 21 is well established. A blood disorder which may be mistaken for acute leukemia may occur in infants with trisomy 21. The authors report a newborn with trisomy 21 and hematologic findings suggesting acute leukemia (hyperleukocytosis, anemia, thrombocytopenia; replacement of bone marrow by blast-like cells). Without treatment spontaneous and complete recovery occurred. Cytochemistry and therapy are discussed in this paper.     

A neurologic comparison of pre-term and full-term infants at term conceptional age.

There are currently no neurologic examinations designed for pre-term infants with sufficient data to determine neurologic deviance at various gestational or conceptional ages (gestational age plus age from birth). In this study a neurologic examination standardized for full-term newborn infants was administered to 97 full-term newborn infants was administered to 97 full-term newborn infants and 97 pre-term infants at their expected date of birth, 40 weeks' conceptional age. The pre-term infants had more weak responses than did the full-term infants despite being at a higher level of activity state throughout the examination. The pre-term infants also had more asymmetric responses. There was no correlation between gestational age and the incidence of weak responses in the pre-term infants, but the pre-term infants of lowest birth weight at all gestational ages had the greatest number of weak responses. The latter may be because pregnancy and neonatal problems contribute more to the neurologic findings than does the length of gestation.     

Skin conductance and behaviour during sensory stimulation of preterm and term infants

Aim: To investigate the responses to painful and tactile stimulation in preterm and term infants in terms of changes in the plantar skin conductance activity (SCA) and behavioural state. Plantar SCA reflects activity in the sympathetic nervous system. Design: The plantar SCA and behavioural state in response to nociceptive (the heel prick for blood samples, or immunization) and tactile (routine nursery handling) simulation was recorded in four different groups of infants (n=71): Preterm and term neonatal infants (defined here as up to 1 week old), and preterm and term infants in the postneonatal period. Results: The preterm infants had significant increases in all skin conductance variables during both tactile and nociceptive stimulation (p<0.02), except for wave amplitude when newborns were heel pricked. The term infants displayed a more varied picture, but both the number and amplitude of the waves increased significantly during both procedures in the newborn groups, while the postneonatal groups only showed significant increases in wave amplitude during nociceptive stimulation (p<0.05). Tactile stimulation of the preterm newborn infants produced significantly higher increases in SCA than nociceptive stimulation (p<0.01), while the behavioural state was highest during nociceptive stimulation (p<0.05). A gradual change in this relation was seen with advancing total age. Conclusion: Non-painful sensory stimulation of infants, especially the newborn and preterm ones, can produce equal or higher levels of physiological stress activation than painful stimulation. Repeated nociceptive stimulation probably sensitises the infants to pain.     

Erythrocyte insulin binding in preterm newborn infants

To characterize the erythrocyte insulin receptor in newborn infants we studied the binding of 125I-insulin to the erythrocytes from 42 preterm infants (14 at birth, 14 aged 2-7 days, and 14 aged 8-16 days) with a mean gestational age of 34.1 wk, and from 32 term infants (16 at birth and 16 aged 2-7 days). The insulin binding to cord blood erythrocytes from preterm infants was significantly higher than that of cord blood cells from term infants and to postnatal cells from preterm as well as term infants. The erythrocytes from preterm infants aged 2-7 days bound more insulin than cells from preterm infants aged 8-16 days. The maximum insulin binding (specific insulin binding at tracer concentration of insulin) correlated negatively with the gestational age both at birth and over the 1st postnatal wk. In the preterm infants there was a strong negative correlation between the maximum insulin binding and postnatal age. The enhanced insulin binding to cord blood erythrocytes from preterm infants was due to both an increased receptor concentration and a high affinity for insulin. The increased affinity persisted over the 1st wk of life. In preterm infants older than 1 wk the insulin binding characteristics were basically similar to those in term newborn infants. In all infants studied the receptor concentration seemed to be postnatal age dependent while the receptor affinity was gestational age dependent. No correlation was found between the insulin binding data and the plasma concentrations of immunoreactive insulin or C-peptide.(ABSTRACT TRUNCATED AT 250 WORDS)     

Basal insulin secretion and erythrocyte insulin binding in preterm and term newborn infants

To study the ontogeny of the insulin secretion and the erythrocyte insulin receptor we measured plasma immunoreactive insulin and C-peptide concentrations and the binding of [125I]-insulin to the erythrocytes in cord blood from 16 preterm and 16 term infants. 20 normal-weight adults were also studied. The C-peptide concentrations and the molar ratio of C-peptide to insulin were lower in the newborn infants than in the adults. The immunoreactive insulin correlated positively with birth weight in the term infants. The insulin binding to erythrocytes from the newborn infants was increased when compared to the adults. Erythrocytes from the preterm infants bound more insulin than the cells from the term infants. There was a strong negative correlation between insulin binding and gestational age. In the term infants, plasma C-peptide correlated negatively with the insulin binding. The increased binding to erythrocytes from the term infants was due to an increase in the receptor concentration. The high insulin binding in the preterm infants was a result of both an increased receptor concentration and affinity. These data suggest that the basal insulin secretion is similar in preterm and term infants and that the clearance of insulin is decreased in newborn infants. The increased insulin binding in newborn infants may be a mechanism by which the growth stimulatory effect of insulin in fetal life is mediated.     

Maternal cell microchimerism in newborn tissues

OBJECTIVES: On the basis of reports of maternal cells being detected in the umbilical cord blood of newborn infants, we tested the hypothesis that maternal cells can migrate out of the circulation into newborn tissues. STUDY DESIGN: We studied autopsy material from 4 newborn infants who never received a blood transfusion and died during the first week of life. The study subjects' diagnoses were trisomy 21 with nonimmune hydrops, 46, XY, 4q+ with multiple congenital anomalies, Potter syndrome, and congenital ichthyosis. Fluorescence in situ hybridization analysis with X and Y chromosome-specific probes was performed on sections of paraffin-embedded tissue, including liver, spleen, thymus, thyroid, and skin. RESULTS: Female cells, as defined by the presence of intact nuclei with two X chromosome signals, were detected in multiple tissue types from all 4 male neonates. The number of female cells varied from 3 to 45 per slide. CONCLUSIONS: Maternal cells enter the fetal circulation and are capable of migration to fetal and neonatal organs. This is of importance with regard to potential consequences of umbilical cord blood transplantation and postnatal development of autoimmune disease.