Cerebrospinal fluid values in very low birth weight infants with suspected sepsis at different ages.

OBJECTIVES: Lumbar puncture can be an essential part of the septic work-up in premature infants who are at risk for sepsis and meningitis. Cerebrospinal fluid (CSF) values for cell counts, protein concentrations, and glucose concentrations in children and full-term infants are well established. CSF values in premature infants, however, have not been well studied. We sought to determine CSF values in very low birth weight premature infants at different ages (birth, postmenstrual age, and postnatal age). DESIGN: Medical records of all very low birth weight premature infants with suspected sepsis who were admitted to our neonatal intensive care unit between 1991 and 2005 were reviewed. Infants were excluded if they had evidence of intraventricular hemorrhage, sepsis/meningitis, or major congenital abnormalities or had a traumatic lumbar puncture. SETTING: Neonatal intensive care unit. PATIENTS: Patients were 455 infants who underwent lumbar puncture. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Medical records of 455 infants who underwent 648 lumbar punctures were reviewed. Of these, 243 infants met our inclusion criteria, and 88 patients underwent lumbar puncture only at birth. Patients' mean gestational age and birth weight were 28.8 +/- 2.6 wks and 1080 +/- 279 g, respectively. There were no correlations between gestational age and CSF white blood cell (WBC) count or between gestational age and CSF protein concentrations at birth. CSF WBC count remained unchanged at different postmenstrual ages. However, CSF protein concentration decreased with advancing postmenstrual age (Spearman's rho correlation coefficient, r = -.29; p < .01), and both CSF WBC count and CSF protein concentration decreased with advancing postnatal age (Spearman's rho correlation coefficient, r = -.319 and r = -.376, respectively; p < .01). A subgroup analysis revealed differences in CSF WBC count and CSF protein concentrations between infants who had a lumbar puncture at birth, at 2 wks, and at 3 wks of life at the same postmenstrual age. CONCLUSIONS: In very low birth weight premature infants, CSF WBC count and CSF protein concentrations vary with advancing postnatal and postmenstrual ages.     

Comparison of hemocytometer leukocyte counts and standard urinalyses for predicting urinary tract infections in febrile infants

OBJECTIVES: To compare the accuracy of standard and hemocytometer white blood cell (WBC) counts and urinalyses for predicting urinary tract infection (UTI) in febrile infants. METHODS: Enrolled were 230 febrile infants < 12 months of age. All urine specimens were obtained by suprapubic bladder aspiration and microscopically analyzed by the standard urinalysis (UA) and by hemocytometer WBC counts simultaneously, and quantitative urine cultures were performed. Receiver-operating characteristic (ROC) curves were constructed for each method of UA. The optimal cutoff point of the UA test in predicting UTI was determined by ROC analysis. RESULTS: There were 37 positive urine cultures of at least 1,000 CFU/ml. Of these 37 patients, 9 females and 28 males, 1 had a positive blood culture (Escherichia coli). Thirty (81%) of the positive urine cultures had a bacterial colony count > or = 100,000 colony-forming units/ml, whereas the remaining had between 1,000 and 50,000 colony-forming units/ml. The area under the ROC curve for standard UA was 0.790 +/- 0.053, compared with 0.900 +/- 0.039 for hemocytometer WBC counts (P < 0.05). For hemocytometer WBC counts, the presence of < or =10 WBC/microl appeared to be the most useful cutoff point, yielding a high sensitivity (83.8%) and specificity (89.6%). Standard UA, with a cutoff point of 5 WBC/high power field, had a lower sensitivity (64.9%) and similar specificity (88.1%). The hemocytometer WBC counts showed significantly greater sensitivity and positive predictive value (83.8 and 60.8%, respectively) than the standard urinalysis (64.9 and 51.1%, respectively) (P < 0.05). The accuracy, specificity and likelihood ratio of hemocytometer WBC counts were also greater than that of standard UA (88.7, 89.6 and 8.08% vs. 84.3, 88.1 and 5.44%). CONCLUSION: Hemocytometer WBC counts provide more valid and precise prediction of UTI in febrile infants than standard UA. The presence of > or =10 WBC/microl in suprapubic aspiration specimens is the optimum cutoff value for identifying febrile infants for whom urine culture is warranted.     

Urinary tract infection in very low birth weight preterm infants

BACKGROUND: The prevalence of urinary tract infection (UTI) in preterm neonates ranges between 4 and 25%. The need for a radiologic investigation has not yet been established in very low birth weight premature newborns (<1500 g birth weight). PATIENTS AND METHODS: For an 11-year period (1990 to 2001), medical records of 62 very low birth weight premature infants admitted to a Level III neonatal intensive care unit and who developed UTI were reviewed retrospectively. Results of renal ultrasound and voiding cystourethrograms were compared between extremely low birth weight infants (birth weight, <1000 g) (Group A, Patient 34) and premature infants with birth weight between 1001 and 1500 g (Group B, Patient 28). RESULTS: UTI was more common in Group A (12.2%) than in Group B (5.7%) infants. Renal ultrasound detected mild renal pelvic dilatation (unilateral or bilateral) in 9 infants in Group A (26%) and in 1 infant in Group B (3.5%). Voiding cystourethrograms were performed in 26 of 34 (76%) infants in Group A and in 17 of the 28 (61%) premature infants in Group B. Vesicourethral reflux (VUR) was observed in 6 infants, 2 in group A (7.7%) and 4 in Group B (23%). CONCLUSIONS: We found that the rate of VUR was lower in very low birth weight premature newborns than that reported in the medical literature among term newborns who developed UTI. VUR was less frequent in extremely low birth weight infants who developed UTI than in infants weighing 1001 to 1500 g.     

Postnatal growth curve of the infant with extremely low birth weight who was fed enterally

The primary objective of this study was the establishment of a postnatal growth curve for the very low-birth-weight infant. Only infants whose size was appropriate for gestational age and whose predominant form of nourishment was enteral were included in the study. Two growth curves were constructed: one for infants weighing less than 900 g (group A, birth weight 799 +/- 79 [SD] g, mean gestational age 26.5 weeks), and one for infants weighing 901 to 1,100 g (group B, birth weight 1,023 +/- 53 [SD] g, mean gestational age 28.5 weeks). Growth was followed over the first 50 postnatal days. Group A infants gained an average of 10.2 g/d overall during the first 50 postnatal days and group B infants gained an average of 17.1 g/d over the same period. Because the major objective of this study was construction of a growth curve for infants weighing less than 900 g, direct comparison is made with the Dancis grid (1948) as this is the only standard for this group. The growth rates of our infants were found to be more than twice that of the original prediction of Dancis.     

Necrotizing enterocolitis in the first 24 hours of life

Necrotizing enterocolitis (NEC) is commonly thought of as occurring in the sick premature infant, usually in the first one to two weeks of life. A review of NEC at the Children's Hospital of Denver over a 5-year period, found that 13 of 79 infants (16.1%) had onset of NEC during the first day of life. These infants were larger (mean birth weight 2,624 +/- 849 g), more mature (mean gestational age 37.9 +/- 2.5 weeks), and less asphyxiated as judged by Apgar scores (mean five-minute score 8.15 +/- 1.07) than infants with onset of NEC after the first day of life (mean birth weight 1,519 +/- 586 g, mean gestational age 32.0 +/- 3.5 weeks, P less than .001, and mean five-minute Apgar score 6.81 +/- 1.84, P less than .05). Despite their large size and degree of maturity, eight of these infants (62%) showed signs of respiratory distress; four (31%) were polycythemic; four (31%) had either a partial or double-volume exchange transfusion performed; and 11 (85%) were fed prior to developing NEC. Presenting signs of disease, occurrence of sepsis (31%), requirement for surgical intervention (62%), and mortality (30%) were similar for the two groups of infants. It is suggested that term and near-term infants who have significant illness after delivery be treated more like their premature counterparts with cautious introduction of feedings after an adequate period of stabilization.     

Low serum levels of mannose binding lectin are a risk factor for neonatal sepsis

Mannose binding lectin (MBL) is a soluble pattern recognition receptor of innate immunity that binds a wide range of pathogens and exerts opsonic effects. We investigated the association between serum MBL levels and development of sepsis in infants admitted to neonatal intensive care units (NICUs). Serum MBL levels on admission were measured by enzyme-linked immunosorbent assay (ELISA) in 206 neonates consecutively admitted to an NICU of whom 138 did not develop hospital-acquired sepsis and 68 did. Of these 68, 40 had confirmed sepsis with positive blood cultures, 19 clinically suspected sepsis, with negative blood cultures, and nine had clinically suspected sepsis with blood culture yielding coagulase-negative staphylococci (CoNS). Serum MBL levels on admission were significantly lower in infants with sepsis [0.45 microg/mL; interquartile range (IQR) 0.09-1.68], particularly in those with confirmed sepsis (0.17 microg/mL; IQR 0.05-0.96), compared with infants without sepsis (1.45 microg/mL; IQR 0.43-3.52), and infants with CoNS-positive blood culture (1.70 microg/mL: IQR 0.85-3.60). After adjusting for duration of exposure gestational age (GA) and birth weight (BW), the association of low MBL levels with development of sepsis was maintained [odds ratio (OR) = 0.52; 95% confidence interval (CI): 0.36-0.75]. The measurement of serum MBL levels on admission in NICU may help to identify neonates at higher risk of developing sepsis.     

The influence of NaCl supplementation on the postnatal development of urinary excretion of noradrenaline, dopamine, and serotonin in premature infants

The present study was designed to investigate the role of noradrenaline (NA), dopamine (DA), and serotonin (5-HT) in the adaptation of premature infants to alterations of sodium balance. Urinary excretion of NA, DA, and 5-HT was measured spectrofluorimetrically in a group of low birth weight premature infants with (group S) and without (group NS) NaCl supplementation. Group NS consisted of 10 infants with a birth weight of 1200-1750 g (mean, 1493 g) and gestational age of 28-31 wk (mean, 30.1 wk). Group S included 10 infants with mean birth weight of 1414 g (range, 1150-1600 g) and mean gestational age of 30.5 wk (range, 27-32 wk). Measurements were made on the 7th day and weekly thereafter until the 5th wk of life. NaCl supplementation was given in a dose of 3-5 and 1.5-2.5 mEq/kg/day for 8-21 and 22-35 days, respectively. In group NS, mean urinary excretion of NA and DA increased from 8.6 +/- 1.5 and 15.8 +/- 2.4 micrograms/day to maximum values of 21.4 +/- 5.5 (p less than 0.05) and 33.4 +/- 6.0 micrograms/day (p less than 0.01) in weeks 2-3, respectively. 5-HT excretion averaged about 60 micrograms/day and showed no consistent change during the course of the study. NaCl supplementation prevented the rise of NA and DA excretion above the initial baseline values. The postnatal course of 5-HT excretion, however, remained unaffected by NaCl supplementation. Urinary excretion of NA in weeks 2-3 (p less than 0.05) and DA in weeks 2-4 (p less than 0.05) were significantly lower in group NS.     

Preterm infants with low immunoglobulin G levels have increased risk of neonatal sepsis but do not benefit from prophylactic immunoglobulin G

OBJECTIVE: In a prospective, randomized, placebo-controlled, multicenter study, we evaluated the prevention of neonatal infections with intravenous immunoglobulin G (IVIgG) prophylaxis for preterm infants (gestational age <33 weeks) with umbilical cord blood IgG levels < or =4 g/L. STUDY DESIGN: Intravenous IgG or placebo (albumin), 1 g/kg body weight, was given on days 0, 3, 7, 14, and 21 to 81 infants with umbilical cord blood IgG levels < or =4 g/L: (1) IVIgG group, n = 40, mean (SD) gestational age 27.5 (2.2) weeks and birth weight 1.06 (0.39) kg; (2) placebo group, n = 41, mean (SD) gestational age 27.7 (2.5) weeks and birth weight 1.13 (0.38) kg. Infants with umbilical cord blood IgG levels >4 g/L (n = 238) served as a separate comparison group. Neonatal infections according to European Society of Pediatric Infectious Disease criteria were monitored until 28 days of life. RESULTS: Infants with IgG levels < or =4 g/L at birth who received IVIgG had no significant reduction in infectious episodes or mortality rate when compared with those given placebo. However, infants with a serum concentration of IgG >4 g/L at birth had significantly fewer infectious episodes (culture-proven sepsis) than infants with low serum concentrations of IgG (< or =4 g/L) when compared at the same gestational ages (26 to 29 weeks, P <.003). CONCLUSIONS: Prophylactic immunotherapy with IVIgG did not improve the immune competence in preterm infants with low serum IgG concentrations at birth. We speculate that a spontaneously high serum IgG concentration at birth reflects placenta function and is an indicator of a more mature immune system capable of protecting the preterm infant against severe neonatal infections.     

Sterile cerebrospinal fluid pleocytosis in young infants with urinary tract infection

BACKGROUND: During the first 3 months of life febrile infants are subjected to sepsis workup, which includes evaluation for urinary tract infection (UTI) and meningitis. We investigated the existence of concomitant meningeal inflammation in infants younger than 90 days old affected with UTI. METHODS: We reviewed the medical records of all infants younger than 90 days old, who were hospitalized for UTI from January, 1990, to January, 2001. For the diagnosis of sterile cerebrospinal fluid (CSF) pleocytosis, the child's age, the CSF total white blood cell (WBC) count and the CSF absolute neutrophil count were taken into consideration. CSF pleocytosis was defined as the presence of > or = 35, > or = 21 and > or = 15 WBC/mm3 of CSF during the first, second and third month of life, respectively. The CSF Gram-stained smear, latex agglutination test and bacterial culture were negative. RESULTS: Sterile CSF pleocytosis was found in 15 (12.8%) of 117 infants with UTI who had had a lumbar puncture included in their initial laboratory evaluation. The 15 infants had a median age +/- semiinterquartile range of 40 +/- 25 days (range, 4 to 75 days). In these infants the median CSF WBC count +/- semiinterquartile range was 55 +/- 125/mm3 (range, 21 to 1,270/mm3). CONCLUSIONS: Sterile CSF pleocytosis was found in 12.8% of infants younger than 90 days old with UTI. The pathogenesis of this meningeal inflammation is not fully understood. Although bacterial infection of the subarachnoid space, with low bacterial seeding, cannot be excluded, at least in some cases, it is possible that CSF pleocytosis in some of the infants with UTI is mainly caused by the endotoxin of Gram-negative or other inflammation-inducing molecules of Gram-positive urine pathogens.     

Amino acid concentrations in plasma and urine in very low birth weight infants fed protein-unenriched or human milk protein-enriched human milk

Preprandial plasma and urine amino acid concentrations were measured in 28 growing, very low birth weight, appropriate-for-gestational-age infants randomly assigned to either protein-unenriched (n = 14) or human milk protein-enriched (n = 14) human milk. The two groups of infants had similar birth weights (900 to 1500 g) and gestational ages (26 to 32 weeks). The study was initiated at a mean age of 19 days when the infants tolerated full feeding volumes and lasted for a mean time of 28 days. Mean protein intake values were 2.1 +/- 0.3 and 3.6 +/- 0.3 g/kg per day (mean +/- SD) and weight gain values were 26.6 +/- 7.4 and 35.1 +/- 3.6 g/day in the protein-unenriched and the protein-enriched groups of infants, respectively. Human milk protein enrichment resulted in significantly increased concentrations of all plasma amino acids except serine, taurine, and histidine. Most urine amino acid concentrations correlated with protein intake and with the plasma concentrations, suggesting that the effects of protein quality and quantity can be evaluated by measuring urinary amino acid concentrations alone, thereby making such studies less invasive. Infants fed protein-unenriched human milk had growth rates below the estimated intrauterine rate as well as low plasma and urine amino acid concentrations, indicating suboptimal protein intake levels. When the plasma concentrations of the essential amino acids in the protein-enriched infants from the present study were compared with concentrations found in the literature in fetal and umbilical cord plasma, both were found to be much higher.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cord blood and postnatal serum leptin and its relationship to steroid use and growth in sick preterm infants

OBJECTIVE: To study the effect of prenatal and postnatal glucocorticoids use on serum leptin and weight gain in sick preterm infants and its correlation with caloric intake. METHODS: Serum leptin was measured in 24 neonates at day 1 (cord), 14 and 28 by radioimmunoassay. Total caloric intake (enteral and parenteral) and weight were measured on days 14 and 28 of life. RESULTS: Mean birth weight and gestational age of study infants were 864 +/- 273 g (mean +/- SD) (range 520-1755 g), and 26.6 +/- 2.4 weeks (23-32 weeks) respectively. Cord blood leptin was greater in infants whose mothers received antenatal steroids (1.98 +/- 1.05 ng/ml vs 0.94 +/- 0.39 ng/ml, p=0.004). Serum leptin increased postnatally from 1.52 +/- 1.0 ng/ml at birth to 2.2 +/- 1.3 ng/ml on day 28 of life (p=0.03). Mean serum leptin had an inverse exponential relationship with postnatal weight gain by day 28 of life (R2=0.56). Total caloric intake on days 14 and 28 of life did not correlate with postnatal weight gain. CONCLUSIONS: Increased serum concentration of leptin following glucocorticoids may be associated with poor weight gain in sick preterm infants.     

Evaluation of routine lumbar punctures in newborn infants with respiratory distress syndrome

Infants with respiratory distress syndrome are routinely evaluated for infection which commonly includes a lumbar puncture. In this study cerebrospinal fluid (CSF) examination failed to elicit evidence for meningitis in 238 consecutively admitted infants with respiratory distress syndrome evaluated during the first 24 hours of life. Blood cultures were obtained in all; suprapubic or catheterized urine was obtained in 163 infants; CSF was collected successfully in 203 infants. Seventeen infants demonstrated positive blood cultures: 7 Streptococcus, 5 Staphylococcus, 3 Haemophilus influenzae, 1 Bacillus subtilis and 1 diphtheroid infection. CSF obtained from 14 of those infants had normal examinations and sterile cultures. Factors associated with bacteremia were birth weight (P less than 0.01), gestational age (P less than 0.01), prolonged rupture of membranes (P less than 0.05) and leukopenia below 10 000/mm3 (P less than 0.05). In view of the negative CSF examinations in infants with positive blood cultures and the potential complications of lumbar puncture (hypoxia, trauma, infection, epidermoid tumor), the potential risks of CSF evaluation may exceed the assessed benefit for the infant with respiratory distress syndrome.     

The effect of neonatal sepsis on bone turnover in very-low birth weight premature infants

Neonatal sepsis is very common in preterm infants, and severe morbidity during the neonatal period is a major cause of osteopenia of prematurity. We examined the effect of neonatal sepsis on bone turnover markers in premature infants. Twenty-four premature infants participated in the study. Ten of the premature infants developed sepsis during their hospitalization in the neonatal intensive care unit (mean gestational age [GA] 27.3 +/- 0.4 weeks; mean birth weight [BW] 898 +/- 82 g). Fourteen infants who did not develop sepsis served as controls (GA: 26.8 +/- 0.8 weeks, BW: 892 +/- 66 g). Blood samples for bone turnover markers were collected during the initial sepsis workup, and at the end of the first week of treatment, and were compared to the corresponding weekly changes in bone markers in the controls. In addition, samples were collected at the end of the 10th week of life to determine long-term effects of sepsis on bone turnover. Bone osteoblastic activity was assessed by measurements of circulating osteocalcin, bone-specific alkaline phosphatase (BSAP) and the C-terminal procollagen peptide (PICP) levels. Bone resorption was assessed by measurements of circulating carboxy terminal cross-links telopeptide of type I collagen (ICTP). There were no significant differences in the weekly changes of all bone turnover markers in premature infants who developed or did not develop sepsis. No significant differences were found in bone turnover markers at the age of 10 weeks between the groups. Neonatal sepsis in premature infants was not associated with biochemical evidence of reduced bone turnover.     

Impaired sensitivity of a single early leukocyte count in screening for neonatal sepsis

The common clinical practice of using a single, early white blood cell (WBC) count to screen for early onset neonatal sepsis was investigated in a population of 61 newborn infants with culture proven sepsis in the first 3 days of life. Thirteen patients (21%) had a falsely normal WBC screening test. The patients with true positive and falsely normal WBC counts did not differ by risk factors for sepsis, birth weight, age, outcome or severity of disease. However, there was a significant delay between the screening test and the positive blood culture in the patients with false normal WBC counts and not in the patients with positive abnormal WBC counts (14.9 +/- 5.9 hours vs. 2.8 +/- 1.4 hr, mean +/- SE, P less than 0.001). A WBC count obtained soon after birth as currently utilized may not adequately screen for early onset neonatal sepsis.     

Determinants of arm muscle and fat accretion during the first postnatal month in preterm newborn infants

We measured arm muscle and fat areas in 22 preterm appropriate for gestational age infants at birth (mean +/- 1 SD birth weight: 1,640 +/- 484 g; gestational age: 31 +/- 2 weeks). Birth arm muscle and fat areas correlated significantly with gestational age (arm muscle: r = 0.86; p less than 0.001; arm fat: r = 0.75; p less than 0.001) and with birth weight. Deviations of birth weights from gestational age means (birth weight z-scores) were related more to variations in arm muscle area (r = 0.69; p less than 0.001) rather than arm fat area (r = 0.44; p = 0.04). Sixteen infants were followed over 4 weeks. They were most physiologically unstable (mean Physiologic Stability Index score = 5.3 +/- 3.5) during the first postnatal week when they also all lost weight. Their mean arm muscle area decreased significantly during the first week by greater than 10%, whereas the mean arm fat area remained unchanged. First week arm muscle losses were directly correlated with the lack of protein intake (r = 0.52; p less than 0.05). The regression equation predicted a protein intake of 4.06 g/kg/day (95% confidence interval: 2.3-6.4) to prevent first week muscle loss. Enteral intake and weight gain were established after week 1, accompanied by a significant reduction in physiologic instability (PSI score = 1.9 +/- 1.9; p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Energy expenditure in premature newborns with bronchopulmonary dysplasia.

Five premature newborns (birth weight, mean +/- SD, 960 +/- 145 g; gestational age 28 +/- 1 weeks) with bronchopulmonary dysplasia (BPD) according to the criteria of Bancalari, and 6 controls (birth weight 1,320 +/- 210 g; gestational age 30 +/- 2 weeks) were studied for energy expenditure (EE) by indirect calorimetry. The measurement of total EE was performed when the intake of the infants in both groups was the same and when the respiratory condition had stabilized (control group: postnatal age 31 +/- 6 days, 1,950 +/- 200 g; BPD group: postnatal age 105 +/- 45, postnatal weight 2,440 +/- 380). The BPD group had a higher VO2 (11.15 vs. 8.04 ml/kg/min, p less than 0.01), VCO2 (9.13 vs. 7.74 ml/kg/min, p less than 0.02) and total EE (76 vs. 61 kcal/kg/day, p less than 0.02). The highest values were encountered in the 3 more severely ill infants: mean VO2 11.03 ml/kg/min, mean EE 82 kcal/kg/min. In these cases, administration of medium chain triglycerides limits the increase in VCO2 and lowers the respiratory quotient (0.87 vs. 0.96 in controls.     

Postnatal Weight Gain of Exclusively Breast Fed Preterm African Infants

The weight of 64 preterm appropriate for gestational age infants were followed closely during the period of stay in the newborn unit. They were subdivided into three groups: A (1001-1250 g), B (1250-1500 g), and C (1501-1750 g). The mean gestation for these groups were 28.7, 30.5, and 31 weeks, respectively, while mean birth weights were 1132 +/- 81.7 g, 1377 +/- 85.6 g, and 1641 +/- 88.6 g. All were fed their own mothers breast milk during the period of study with no supplements. During the first week, there was significant weight loss in all groups as follows: A (12.0 per cent), B (7.7 per cent), and C (4.4 per cent). Thereafter, only group A lost weight in the second week, but the loss was not significant. Birth weights were regained at 23, 16, and 15 days, respectively. The weight gain after the initial loss was A (20.0 g), B (20.4 g), and C (20.2 g) per day. Group A had the fastest growth rate.     

Screening for familial hypercholesterolemia in 5000 neonates: a recall study

To investigate the feasibility of screening for familial hypercholesterolemia, apolipoprotein B (Apo B) levels were determined in dried blood spot samples on neonatal screening cards from 5000 consecutively born neonates, by radial immunodiffusion assay. The 103 infants with Apo B levels in the top 2% were recalled for repeat dried blood spot Apo B determinations. Forty-five of the 103 infants were retested, and serum lipid profiles and Apo B levels were determined for both parents of 43 of these infants, and for the mother only for the other two infants. The recalled "top 2%" group had a higher proportion of females, a higher mean birth weight, a higher mean gestational age and a higher proportion of infants sampled initially on day 5 than in the total screened population, consistent with our previously determined influence of these factors on Apo B levels at screening. The retested group (n = 45) was representative of the total recalled group (n = 103) with respect to Apo B levels at screening, sex, birth weight, gestational age, and age at sampling for screening. The infants' mean +/- SD age at retesting was 12.3 +/- 3.3 months. Their mean Apo B value on retesting was 0.65 +/- 0.20 g/liter of whole blood (range 0.30 to 1.16 g/liter). Two fathers had had coronary bypass surgery by the age of 40 and had type II lipid profiles and elevated serum Apo B levels. For both, their child had elevated Apo B levels at recall (both 1.05 g/liter of whole blood).(ABSTRACT TRUNCATED AT 250 WORDS)     

Influence of gestational age and intrauterine growth on leptin concentrations in venous cord blood of human newborns

BACKGROUND: The ob gene product leptin is involved in the regulation of body weight and energy expenditure, suggesting a potential role of leptin in embryonal and fetal development and progression of pregnancy. In term infants, leptin concentrations showed a positive correlation with birth weight. We aimed at comparing leptin cord blood levels in AGA (appropriate for gestational age) to SGA (small for gestational age) preterm and term newborns. PATIENTS AND METHODS: Ninety-seven human newborns, 47 females and 50 males, 33 born at term and 64 born before 36 weeks of gestation, were studied prospectively. Leptin concentrations in venous cord blood were determined using a specific RIA (radioimmunoassay). RESULTS: In term newborns, mean gestational age (GA) was 39 weeks (wk) (+/- 0.7 wk) and mean birth weight (BW) was 3316 g (+/- 473 g); in preterm newborns (n = 64), mean GA was 30 wk (+/- 5.0 wk) and mean BW was 1398 g (+/- 505 g). Mean standard deviation score of birth weight (BW SDS) was calculated as - 0.47. Mean leptin concentrations in term newborns differed significantly from those in preterm newborns (9.21 +/- 2.63 ng/ml vs. 1.58 +/- 0.88 ng/ml; p < 0.0001). In preterm and term infants, leptin concentrations showed a linear correlation with BW (r = 0.46; p < 0.0001) and GA (r = 0.48; p < 0.0001), respectively. Leptin levels were best predicted by an exponential regression model with GA (Leptin = exp(- 4.41 + 0.14 x GA); r = 0.61; p < 0.0001). Using multivariate regression analysis (r = 0.57; p < 0.0001), we found significant influences of GA (p < 0.00001) and BW SDS (p < 0.05) on leptin levels. No difference was observed between leptin values in AGA versus SGA preterm infants. CONCLUSION: These data suggest fetal leptin levels to be primarily determined by GA and additionally modulated by growth restriction in term newborns. We found a dramatic increase at weeks 33 to 35 of gestation and no modulation by BW SDS in very preterm infants.     

Urinary excretion of prostaglandin E and F 2 alpha in healthy newborn infants and in infants with hyaline membrane disease

Urinary PGE and PGF 2 alpha excretion was estimated in 11 healthy full-term (mean birth weight, 3327 g; mean gestational age, 39.2 weeks). 15 healthy preterm (mean birth weight, 1722 g; mean gestational age, 32.1 weeks) and in 9 preterm infants suffering from hyaline membrane disease (HMD) (mean birth weight: 1454 g, mean gestational age: 31 weeks). Measurements were carried out on the 1st, 3rd and 5th days of life by radioimmunoassay, using Clinical Assays Inc. RIA kits. Urinary PGE excretion on the first day of life was 3.76 +/- 0.41 ng/day, 2.43 +/- 0.65 ng/day and 1.19 +/- 0.27 ng/day for healthy full-term, healthy premature and premature infants with HMD, respectively. The differences were significant at the level of p less than 0.05. With advancing postnatal age urinary PGE excretion markedly increased in each group (p less than 0.05). Urinary PGF 2 alpha excretion on the first day was 10.8 +/- 2.0 ng/day in full-term, 6.6 +/- 2.2 ng/day in healthy premature and 4.35 +/- 1.9 ng/day in premature infants with HMD. Then an inconsistent rise could be observed without statistically significant difference between the individual groups of various postnatal age and between the different groups of the same postnatal age. The decreased renal PGE production is suggested to be involved in the pathomechanism of HMD.