bluuebunny/crossref_metadata_2025 huggingface dataset:
Lung Gas Volumes and Expiratory Time Constant in Immature Newborn Rabbits Treated with Natural or Synthetic Surfactant or Detergents
Authors: Bongrani Stefano , Fornasier Massenzio , Papotti Mario , Razzetti Roberta , Robertson Bengt
Published: October 2009

Immature newborn rabbits delivered at a gestational age of 27 days were tracheotomized and treated, via the tracheal cannula, with clinically recommended doses of natural or synthetic surfactant (Curosurf® and Exosurf®, respectively). Littermates received 0.1% tyloxapol, 5% Tween 20, or saline. The dose volume of Curosurf was 2.5 ml/kg, that of the other materials 5 ml/kg. Animals were kept in a multiplethysmograph system and ventilated for 30 min with a standardized sequence of insufflation pressures. End-expiratory lung gas volume was calculated at the end of the experiment from measurements of lung weight and total lung volume. Tidal volumes were significantly improved in all groups of animals receiving surfactant or detergents. However, expiratory time constant (determined from the tidal volume tracing) was significantly longer, and end-expiratory gas volume significantly larger, in animals treated with Curosurf than in those receiving Exosurf or detergents. These differences were confirmed by semiquantitative evaluation of alveolar air expansion in histological sections. In addition, airway epithelial necrosis was reduced in animals receiving Curosurf, Exosurf, or Tween 20, but not in animals treated with tyloxapol. The discrepancy between improvements in tidal volume, expiratory time constant, and end-expiratory gas volume reflects failure of lung stabilization in animals treated with Exosurf or detergents, probably due to absence of specific hydrophobic proteins in the synthetic products.
Cerebral Perfusion Studies during Maturation Using Single Photon Emission Computed Tomography in the Neonatal Period
Authors: Haddad Joseph , Constantinesco André , Brunot Bernard , Messer Jean
Published: October 2009

In this study, we used single photon emission computed tomography (SPECT) radiolabelled 99mTc HMPAO to assess cerebral perfusion during maturation in the neonatal period. Results of SPECT examinations in 18 newborn infants, in whom gestational age ranged form 30 to 41 weeks, and who were found to be neurologically normal in retrospect, were reviewed. The developmental changes in cerebral perfusion during the neonatal period shown by SPECT parallel findings of other methods on maturational changes of the central nervous system (neuropathological studies, positron emission tomography scan, magnetic resonance imaging). Cerebral perfusion progresses from the central part of the brain to the cerebellum, sensorimotor and then visual cortex. A close relation seems to exist between cerebral perfusion, metabolism and behavior under normal conditions in the neonatal period.
Sex Differences in Umbilical Cord Serum Levels of Inhibin, Testosterone, Oestradiol Dehydroepiandrosterone Sulphate, and Sex Hormone-Binding Globulin in Human Term Neonates
Authors: Simmons D. , France J.T. , Keelan J.A. , Song L. , Knox B.S.
Published: October 2009

The contribution of the fetus to inhibin production in human pregnancy is unclear. Previous studies have reported inhibin concentrations in cord blood but on limited sample numbers. The present study is a more extensive examination of sex differences in immunoreactive inhibin and steroidal hormones in term umbilical cord blood. Venous serum concentrations of inhibin were found to be significantly higher in males (mean ± SD 2,168 ± 914 pg/ml, n = 62) than in females (1,761 ± 951 pg/ml, n = 63) (p < 0.01). Male concentrations of total testosterone (p < 0.005), free testosterone (p < 0.005), and estradiol (p < 0.05) were also significantly higher. The concentration of dehydroepiandrosterone sulphate (DHEAS) and the sex hormone-binding globulin (SHBG) capacity were similar in males and females. Multivariate regression analysis showed that the inhibin concentration in males correlated with the testosterone concentration and in females it correlated not only with testosterone concentration but also with gestational age at delivery and SHBG capacity (all p < 0.001). Inhibin concentrations in cord arterial serum in a subgroup of 24 males and 31 females were higher than in the venous serum in both sexes but the differences were not statistically significant. Concentrations of DHEAS determined in 22 female cord arterial blood samples (6.0 ± 2.5 μmol/l) were significantly higher than the venous concentrations (5.2 ± 1.8 μmol/l) (p < 0.05). Inhibin did not correlate with DHEAS either in their arterial serum concentrations or in the arteriovenous concentration differences. The findings of this study are consistent with the placenta being the principal source of inhibin circulating in the human fetus in late pregnancy. Further, they suggest that there are minor sex differences in placental metabolism of inhibin and the steroidal sex hormones.
The Temperature of Inspired Air Influences Respiratory Water Loss in Young Lambs
Authors: Riesenfeld T. , Hammarlund K. , Norsted T. , Sedin G.
Published: October 2009

The temperature of inspired air influences respiratory water loss (RWL) in young lambs. Water loss from the airways, oxygen consumption and carbon dioxide production were measured using an open flow-through system with a mass spectrometer, specially equipped with a water channel, for gas analysis. Measurements were made in 9 newborn lambs at 3 different inspired air temperatures keeping all other environmental factors stable, including the ambient air temperature. The water content of the inspired air was also kept constant. RWL was found to be 9.9 ± 3.9 (SD) mg/kg/min when the temperature of the inspired air was 30°C and its humidity 30%. At 40°C this loss increased to 11.5 ± 3.6 mg/kg/min, and at about 60°C it increased further to 26.0 ± 8.2 mg/kg/ min. The oxygen consumption was 10.0 ± 0.8(SD)ml/kg/min at 30°C and 10.4 ± 2.0 ml/kg/min at 60°C, a change which is not significant. Thus RWL is influenced by the temperature of the inspired air, with greater loss at higher temperatures.
Rubella Embryopathy after Maternal Reinfection
Authors: Paludetto R. , van den Heuvel J. , Stagni A. , Grappone L. , Mansi G.
Published: October 2009

Reinfection with rubella is possible. The real risk for fetus and newborn is not known, as are the incidences of rubella reinfection during pregnancy and congenital rubella infection after maternal reinfection.
Surfactant Bolus Instillation: Effects of Different Doses on Blood Pressure and Cerebral Blood Flow Velocities
Authors: Rey Martin , Segerer Hugo , Kiessling Christiane , Obladen Michael
Published: October 2009

Fifteen preterm infants suffering from respiratory distress syndrome were randomly allocated to receive either high-dose (200 mg/kg) or low-dose (100 mg/kg) surfactant treatment. Retreatments were done with the low dose. Blood pressure, blood gases and cerebral blood flow velocities were determined before and after 24 bolus instillations. With the high dose mean blood pressure and mean cerebral blood flow velocity dropped significantly. With the low dose only mean cerebral blood flow velocity decreased; the course was unrelated to blood pressure or PCO2 fluctuations. The mechanisms leading to the observed circulatory changes after surfactant instillation remain unclear.
Predicting Insensible Water Loss in Premature Neonates
Authors: Doty Susan E. , McCormack William D. , Seagrave Richard C.
Published: October 2009

The insensible water loss from the skin of premature neonates in various environments can be estimated by modeling the skin as a composite membrane and applying Fick’s law to each layer. Studies involving human skin development have made it possible to apply the proposed model to predict an infant’s insensible water loss as a function of gestational age and postnatal age. However, the model tends to overestimate the insensible water loss particularly for gestational ages over 28 weeks. Values used in the model for the diffusivity of water through the stratum corneum were determined from adult skin rather than neonatal skin, which may be a factor in the overestimation.
Ketotifen in the Management of Infants with Bronchopulmonary Dysplasia
Authors: Rubaltelli Firmino F. , Dani Carlo , Zorzi Meneguzzo Carlo
Published: October 2009

Ketotifen, a histamine (Hi) antagonist, inhibits PAF-induced eosinophil accumulation and airway hyperreactivity. Bronchopulmonary dysplasia (BPD) is a complex disorder in which bronchial hyperreactivity is usually present. An open randomized trial was carried out with this agent in infants with chronic BPD who were followed up for 6 months. The efficacy of the drug was evaluated according to respiratory symptom and medication scores, in which numerical values were assigned to various other antiasthmatic agents used to control wheezing. No adverse clinical or biochemical sequelae were noted during treatment. The mean respiratory symptom and mean medication scores were significantly higher worse in the control group in comparison with the infants treated with ketotifen.
Elevated Erythropoietin Levels in Cord Blood of Newborns with Down’s Syndrome
Authors: Widness John A. , Pueschel Siegfried M. , Pezzullo John C. , Clemons Gisela K.
Published: October 2009

Plasma erythropoietin (Ep) was determined in umbilical cord blood in 18 infants with Down’s syndrome. The 16 infants with Down’s syndrome who were delivered after labor had significantly elevated plasma Ep levels compared to 36 control infants born after labor (p < 0.001). Six of the ten infants with Down’s syndrome who had their packed cell volume (PCV) measured in the first 24 h of life were polycythemic based on a PCV of > 0.65. The presence of congenital heart disease in 9 of the 18 infants with Down’s syndrome was not associated with a higher plasma Ep or PCV levels. Plasma Ep was correlated with neonatal PCV in the combined group of control and Down’s syndrome infants (p = 0.003). Increased plasma Ep levels observed in infants with Down’s syndrome suggested chronic fetal hypoxemia as a likely explanation for the high incidence of neonatal polycythemia observed in this group.
A Gestational-Age-lndependent Model of Birth Weight Based on Placental Size
Authors: Dombrowski Mitchell P. , Berry Stanley M. , Hurd William W. , Saleh AbdelAziz A. , Chik Larry , Sokol Robert J.
Published: October 2009

A placental weight (P) to birth weight (W) relationship, W = P1.5 × constant (A), was presented in 1966. However, based on histological and theoretical studies, placental efficiency increases proportionally to the square of the gestational age in weeks. The purpose of this study was to develop and validate a gestational-age-independent model of birth weight based on P2. Data were prospectively entered into a computerized database for liveborn, structurally normal neonates at a tertiary, urban center. 29,989 neonates had gestational ages based on menstural dating, ultrasound and Ballard examination, 81.4% were African American. The ‘best fit’ of W = A × P1.5 had errors in predicting the mean birth weight by at least 10% from 24 to 33 weeks of gestation. In contrast, there was significant improvement (p < 0.05) when the model W = 0.0071 × P2 was used; errors of greater than 10% only occurred at 28 and 43 weeks of gestation. This model had similar accuracy when stratified according to gender or ethnicity. A gestational-age-independent model of mean birth weight can be based upon the square of placental weight. We hypothesize that this model may have utility in understanding disorders of intrauterine fetal growth.
Arginine Deficiency Accompanies Persistent Pulmonary Hypertension of the Newborn
Authors: Vosatka Robert J. , Kashyap Sudha , Trifiletti Rosario R
Published: October 2009

Persistent pulmonary hypertension of the newborn (PPHN) is a life-threatening disorder of neonates manifested by vasoconstriction of the pulmonary arteries. Recently, the gas nitric oxide (NO) has been used with some success in the management of infants with PPHN. Exogenous administration of NO selectively dilates the pulmonary vascular bed. NO is naturally synthesized in the body from the amino acid L-arginine. Here we report our findings that infants with PPHN are deficient in arginine and achieve normal or elevated plasma arginine concentrations with intravenous hyperalimentation. We prospectively identified and studied 10 infants with PPHN who were not receiving protein or amino acids for at least 24 h and compared their plasma arginine concentrations to 8 control infants without PPHN given similar nutrition. Plasma arginine concentrations were 32 ± 14 and 52 ± 20 µmol/l in infants with PPHN and control infants, respectively (p = 0.02). There were no other statistically significant differences in plasma amino acid concentration for any of the 22 other amino acids determined. Infants with PPHN who were subsequently treated with amino acid infusions had plasma arginine concentrations of 115 ± 48 µmol/l (mean often determinations at 86 ± 27 h after initiation of intravenous amino acids in five PPHN infants).
Hyperbilirubinemia in Premature Infants: Relevance to Blood Transfusion
Authors: Ergaz Zivanit , Arad Ilan
Published: October 2009

The rate of hemolysis of transfused adult red blood cells in the premature circulation may be higher than in the native circulation and produce a significant bilirubin load on the immature liver during the first days of life with consequent hyperbilirubinemia. The association between the transfusion of packed red blood cells and consequent change of serum bilirubin level was evaluated in 35 premature infants with birth weight of < 1,250 g during the first 10 days of life, using the analysis of variance method. There was a significant increase of bilirubin level with a mean of 24.3 µmol/l following packed red blood cells transfusion. Birth weight had a significant negative effect and mechanical ventilation for > 2 days had a significant positive effect on bilirubin levels; however, the changes were of small magnitude. The results of our study indicate that a rise of bilirubin level following blood transfusion to very low birth weight infants during the early neonatal period should be anticipated.
Hyperoxia Induces Interstitial (Type I) and Increases Type IV Collagenase mRNA Expression and Increases Type I and IV Collagenolytic Activity in Newborn Rat Lung
Authors: Devaskar Uday , Taylor Wiley , Govindrajan R. , Malicdem Milagros , Heyman Sarah , deMello Daphne E.
Published: October 2009

Oxygen toxicity is attributed to the reaction of oxygen metabolites with cellular components leading to cell destruction. Activation of latent human neutrophil interstitial collagenase by reactive oxygen species has been demonstrated. The potential role of collagenases in hyperoxic lung injury has not been investigated. We studied the effect of hyperoxia on newborn rat lung water content, morphology and ultrastructure, interstitial (type I) and type IV collagenase gene expression and type I and IV collagenolytic activity. We observed that hyperoxia causes pulmonary edema, alters newborn rat lung morphology in a sequential manner and produces ultrastructural alterations, induces type I and increases type IV collagenase mRNA expression, and increases type I and IV collagenolytic activity. A role for type I and IV collagenase in hyperoxic newborn lung injury or in the recovery following the injury is proposed.
Sequential Changes in Pulmonary Epithelial Permeability after Birth in Term and Preterm Rabbits
Authors: Jefferies Ann L. , Young Tai Kin Fan
Published: October 2009

We assessed sequential changes in the permeability properties of the pulmonary epithelium in spontaneously breathing, newborn term (30 days of gestation) and preterm (28 days) rabbit pups, using the rate of pulmonary clearance of 99mTc-DTPA (MW = 492) as an index of permeability. In term rabbits, clearance was faster at 1 h of age than at hourly timepoints thereafter (p < 0.05). In preterm rabbits, clearance rates measured from 1 to 5 h after birth were not quite significantly different (p = 0.0519) although the trend to slower clearance with increasing time after birth was significant. When term and preterm rabbits were compared, clearance was similar at 1 h after birth but was faster at both 2 and 3 h in the preterm rabbits (p < 0.05). Pulmonary epithelial permeability appears to be increased in the immediate postnatal period and the duration of increased permeability is longer in preterm rabbits. Because lung water content at birth is greater in the preterm rabbits, we speculate that the permeability changes may be associated with clearance of fetal lung liquid.
Elevated Production of lnterleukin-1-Beta from Alveolar Macrophages Isolated from Newborn Rabbits
Authors: Rozycki Henry J.
Published: October 2009

Alveolar macrophage (AM) production of pro-inflammatory cytokines has been associated with the development of acute and chronic lung injury. However, the role of AM-derived IL·1Β in the development of bronchopulmonary dysplasia has not been extensively examined. To determine if in vitro production of IL-1Β by AM is influenced by maturity, cells were isolated by lung lavage from litters of newborn rabbits and from adults. After overnight incubation in serum-supplemented medium, newborn AM produced more IL-1Β than cells from adults. When these AM were then exposed for 2 h to endotoxin in serum-free medium, adult cells increased their IL-1Β secretion while the newborn cells did not. Newborn AM IL-1Β response to LPS returned by 24 h. AM from newborn rabbits also demonstrated increased spontaneous production and increased LPS-induced production of IL-1Β during overnight incubation in serum-free medium. The newborn rabbit AM appears to be up-regulated in its IL·1Β production compared to the adult.
The Catecholamine Sensitivity of Adult Rats Is Enhanced after Prenatal Hypoxia
Authors: Heydeck D. , Roigas J. , Roigas C. , Papies B. , Lun A.
Published: October 2009

In this study, the effect of prenatal hypoxia on the catecholamine sensitivity of the offspring of pregnant rats was investigated. The offspring from hypoxic animals showed after treatment with isoproterenol in adult age a distinctly more pronounced decrease of protein content and enzyme activities in heart tissue as well as a significantly higher elevation of enzyme activities in blood plasma as compared with the offspring from normoxic rats. These results suggest a long-lasting enhancement of catecholamine sensitivity after prenatal oxygen deficiency.
Effect of Mode of Delivery, Parity and Umbilical Blood Gas on First Meconium Passage in Full-Term Healthy Neonates
Authors: Tateishi Hiroshi , Yarnauchi Yoshitada , Yamanouchi Itsuro , Khasba Mohamed T.
Published: October 2009

The various physiologic factors which might influence the time of first meconium passage were studied in 62 healthy full-term newborn infants. Thirty-two babies were born vaginally and 30 by elective cesarean section. Infants born vaginally were more acidotic and passed first stool earlier compared to those born by cesarean section. The same applies to vaginally delivered babies when comparing babies born to primipara and others. Acidosis is a presumed mechanism, and a role of gastrointestinal hormones is suggested to be the possible mediator of increased motility in these babies.
Short Apneas and Their Relationship to Body Movements and Sighs in Preterm Infants
Authors: Weintraub Zalman , Alvaro Ruben , Mills Sharon , Cates Donald , Rigatto Henrique
Published: October 2009

To test the hypothesis that there is an association among short apneas (3–10 s), body movements, and sighs, we studied 11 preterm infants (body weight 1,500 ± 200 g, mean ± SE; gestational age 30 ± 1 weeks, postnatal age 28 ± 5 days) using a flow-through system. A total of 1,166 apneas, 1,024 movements, and 473 sighs were recorded. Of the 1,166 apneas, 460 (39%) were associated with movements, 91 (8%) with sighs, and 226 (19%) with both movements and sighs. The rate of apneas associated with movements and sighs was significantly greater than expected if only a random association had occurred. These differences remained in quiet, rapid eye movement, and indeterminate sleep. The frequency of each of the three events was similar in a given sleep state. Of the 460 movements associated with apnea, 26% preceded, 23% followed, and 51% occurred during apnea. Similarly, of the 315 sighs associated with apnea, 44% preceded and 56% followed apnea. Apneas preceded by movements were longer than those without movements (5.6 ± 0.2 vs. 4.9 ± 0.1 s; p = 0.01). Oxygen saturation before apnea with movement (94 ± 0.1%) was lower than before apnea alone (96 ± 0.6%; p = 0.02) and also lower than before movement alone (96 ± 0.1%; p = 0.001). These findings suggest: (1) there is a strong association among short apneas, movements, and sighs in these infants; (2) sighs appear not to be an isolated event and are likely to be part of a more general motor discharge, and (3) these events are accompanied by mild desaturations and bradycardias. We conclude that clusters of short apneas, movements and sighs are common in preterm infants and speculate that they are probably mediated via a common central neurogenic mechanism.
Mononuclear Phagocytic Cells in Human Milk: HLA-DR and FcγR Ligand Expression
Authors: Rivas Richard A. , El-Mohandes Ayman A.E. , Katona Ildy M.
Published: October 2009

The study of the cellular immune components of human milk is essential in the understanding of the role human milk may play in protecting the nursing infant against infection. We have investigated some phenotypic characteristics of breast milk macrophages (BMM) and have compared them to the characteristics of adult peripheral blood monocytes (PBM) by using dual parameter flow microfluorometry. Most BMM expressed the monocyte/macrophage markers Leu-M3 and Leu-M5. The latter marker was present in high density (bright) on BMM, but the density of expression of Leu-M3 was higher on PBM than on BMM [median fluorescence intensity (MFI) 409 ± 105 versus 203 ± 106, p = 0.02]. The percentage of BMM (98 ± 2) that expressed the HLA-DR antigen did not differ significantly from PBM, but the density of expression was higher on BMM (MFI 318 ± 56 versus 264 ± 41, p = 0.03). The HLA-DR expression of BMM was further enhanced after incubation with interferon-γ for 36 h; however, receptor for interleukin-2 could not be induced on BMM by this treatment. The expression of the three classes of FcγR was lower on BMM than on PBM, in percentage (FcγRI 56 ± 23 versus 79 ± 17%, p = 0.02), density of expression (FcγRIII MFI 71 ± 20 versus 153 ± 73, p = 0.002), or both (FcγRII 74 ± 22% versus 94 ± 12%, p = 0.02, and MFI 115 ± 53 versus 202 ± 59, p = 0.003). These findings help to define the BMM as a Leu-M3+ (dull), HLA-DR ± (bright), phenotypically mature macrophage with a specifically low expression of the FcγR ligands. These cell surface characteristics could be ontogenic in nature, or could reflect pregnancy-induced down-regulation of the maternal immune system.
Hypoxia-Ischemia in the Neonatal Rat Brain: Histopathology after Post-Treatment with NMDA and Non NMDA Receptor Antagonists
Authors: Hagberg Henrik , Gilland Eric , Diemer Nils-Henrik , Andiné Peter
Published: October 2009

In a model of perinatal hypoxic-ischemic brain damage, we examined the neuroprotective efficacy of posttreatment with the NMDA receptor antagonist MK-801 and the AMPA receptor antagonist NBQX. Unilateral brain damage developed in 95% of rat pups subjected to hypoxia-ischemia with a 27.8 ± 1.2% weight deficit of the damaged hemisphere. MK-801 in doses of 0.3 and 0.5 mg/kg i.p. reduced the brain damage by 61% (p < 0.001) and 43% (p < 0.001), respectively. A higher dose of MK-801 (0.75 mg/kg) did not offer neuroprotection. Treatment with NBQX (40 mg/kg) reduced the hemispheric lesion by 28% (p < 0.05). In conclusion, posttreatment with both NBQX and low doses of MK-801 reduced perinatal brain damage. The NMDA receptor antagonist offered stronger neuroprotection which is in agreement with a proposed NMDA receptor hyperactivity around postnatal day 7 in rats.
Comparison of Colony Stimulation Factors on in vitro Rat and Human Neutrophil Function
Authors: Wheeler Gary , Huffine Mary Elizabeth , Childress Sherry , Sikes Jim
Published: October 2009

The effects of rhCSFs on in vitro polymorphonuclear leukocyte (PMN) function were studied in Sprague-Dawley neonatal and adult rats and adult and umbilical cord derived human PMN to compare species response. Following in vitro exposure to buffer or rhCSFs (50–100 μg/ml), PMN oxidative burst, chemotactic activity and adherence protein expression were measured. RhG-CSF increased the oxidative burst of adult rat PMN as measured by chemiluminescence and altered CD lib/CD 18 in resting neonatal rat but not adult rat cells. RhGM-CSF had no effect on adult rat PMN function in vitro, but led to modest changes in adult rat PMN diapedesis across rat peritoneum. No responses were noted to rhM-CSF. Human PMN responded best to GM-CSF (particularly in the neonate), intermediately to G-CSF and none to M-CSF. These experiments show that the profile of cytokine effects is not similar in adult and neonatal rat PMN when compared to human cells. The diversity of actions in other species must be considered when using rhCSFs in animal models.
Ornithine Decarboxylase Activity and Concentrations of Polyamines in Embryos of Diabetic Rats
Authors: Bengtsson Bengt-Ola , Wiberg Kristina , Eriksson Ulf J.
Published: October 2009

Previous studies have demonstrated high concentrations of polyamines in neoplastic tissue and embryos and these compounds are therefore believed to play a role in cellular growth and embryonic development. Maternal diabetes causes embryonic dysmorphogenesis and alterations in embryonic polyamine concentrations may contribute to this process. In the present study we have measured the contents of DNA, putrescine, spermidine and spermine in embryos on days 10 and 11 of gestation in normal and diabetic rats. We also estimated the activity of ornithine decarboxylase (ODC) in embryos on days 9–11. We found that maternal diabetes causes delayed growth as reflected by decreased content of DNA on day 11 in the embryos of the diabetic group. Both the polyamine content and ODC activity were altered in the embryos of diabetic rats. Thus, the polyamines were increased on day 10 and decreased on day 11, and the ODC activity was decreased in a down-regulated manner in day-10 embryos of the diabetic rats. These findings suggest that polyamine metabolism is involved in the dysmorphogenesis of diabetic pregnancy.
Identification of CD34+ Cord Blood Cells and Their Subpopulations in Preterm and Term Neonates Using Three-Color Flow Cytometry
Authors: Meister Bernhard , Tötsch Martin , Mayr Andrea , Widschwendter Martin , Huter Otto , Sperl Wolfgang
Published: October 2009

Three-color flow cytometry was used to identify CD34+ cord blood (CB) hematopoietic progenitors of preterm (n = 13) and term (n = 18) neonates. The frequency of CD34+ CB cells gated on the lymphocyte fraction in term neonates is about half the frequency of preterm neonates (mean 1.84 ± 0.8 vs. 3.49 ± 1.8, p < 0.005). The difference of absolute CD34+cells between the 2 groups did not reach statistical significance (premature 169 ± 161 vs. mature 108 ± 62.6 × 106 cells/1). The proportion of myeloid lineage-committed CD34+ cells coexpressing the CD 33 antigen in preterm neonates does not significantly differ from that found in term neonates. However, in preterm neonates a higher fraction of erythroid lineage-committed CD34+ cells coexpresses the CD71 antigen as compared with term neonates (mean 28.7 ± 14.1 vs. 11.4 ± 5.7, p < 0.001). The positive correlation between gestational age and the ratio of myeloid/erythroid lineage-specific progenitor cells (r = 0.61, n = 31, p < 0.0005) suggests gestational changes in lineage commitment of CD34+ cells.
Dose-Effect Relationship of Bilirubin on Striatal Synaptosomes in Rats
Authors: Amato Maurizio M. , Kilguss Nelda V. , Gelardi Nancy L. , Cashore William J.
Published: October 2009

The uptake of tyrosine as precursor of dopamine in striatal nerve endings was studied in rat striatal synaptosomes to evaluate the role of different bilirubin concentrations on this mechanism of synaptic neurotransmission. Freshly prepared striatal synaptosomes obtained from adult male Sprague-Dawley rats (200–300 g) were homogenized in about 25 vol of 0.32 M sucrose and 5 nM Hepes at pH 7.4 and centrifugated at 12,000–16,000 rpm for 20 min. 14C tyrosine was evaporated under N2 and resuspended in tyrosine 100 μl/ml. Different concentrations of crystalline bilirubin ranging from 70 to 140 μM at 10-min intervals were prepared. Eighty microliters of synaptosomes were added to 5 μl of the different bilirubin concentrations and 20 μl of 14C tyrosine. The results of this study show a statistically significant correlation between bilirubin levels and tyrosine uptake in rat synaptosomes (p < 0.05) supporting the hypothesis that the effect of bilirubin on neuronal excitability is dose-dependent.
Copper Distribution in Fetus and Placenta of the Macular Mutant Mouse as a Model of Menkes Kinky Hair Disease
Authors: Xu Gui-Qin , Yamano Tunekazu , Shimada Morimi
Published: October 2009

Menkes kinky hair disease (MKHD)in humans is caused by a disturbance in copper homeostasis. A mutant mouse shows clinical and biochemical features very close to MKHD. In an attempt to elucidate the defect in copper transport, the copper distribution in various organs of 18-gestational-day-old macular mouse embryos, following administration by a single injection of saline (control) or 50 μg of CuCl2 on day 16 of gestation or by two injections on days 15 and 17 of gestation to the dams, was examined both biochemically and histochemically. The copper content in the hemizygous fetus (M1/y) born to the homozygous mother, who had no copper injection during gestation, was lower in the brain and liver but higher in the placenta than in the respective organs of the normal fetus. When 50 μg of CuCl2 was injected into heterozgyous dams (M1/+) on day 16 of gestation, their hemizygous fetuses showed a slight increase in the copper content in the brain and liver, but the amount of copper in these organs was still less than that of the normal fetus. Conversely, the copper content in the placenta of the hemizygous fetus was far higher than that of the normal fetus. In the copper staining of the fetuses harvested from heterozygous dams, some fetuses showed copper deposition in the placenta, but not in the liver. The others showed no copper deposit in both the placenta and liver, thus indicating that the former were hemizygous for the mutation and the latter were normal littermates. These results indicate that the placenta of the hemizygous fetus has a primary defect in copper transport. Most of the copper administered to the heterozygous dam cannot be transported to the hemizygous fetus. These results also indicate that copper administration to pregnant women will not be beneficial to the MKHD fetuses and will adversely affect fetal maturation.
Myoclonus Associated with Lorazepam Therapy in Very-Low-Birth-Weight Infants
Authors: Lee David S.C. , Wong Adriana , Knoppert David C.
Published: October 2009

Lorazepam is being used with increasing frequency as a sedative in the newborn and the young infant. Concern has been raised with regard to the safety of lorazepam in this age group, especially in very-low-birth-weight (VLBW; < 1,500 g) infants. Three young infants, all of birth weight < 1,500 g, experienced myoclonus following the intravenous administration of lorazepam. The potential neurotoxic effects of the drug (and its vehicle) in this population are discussed. Injectable lorazepam should be used with caution in VLBW infants.
Middle Cerebral Artery Velocity Waveforms in Fetuses with Absent Umbilical Artery End-Diastolic Flow
Authors: Mimica Marko , Pejković Lidija , Furlan Ivanka , Vulić-Mladinić Denis , Praprotnik Tanja
Published: October 2009

Middle cerebral artery (MCA) velocity waveforms were analyzed in 21 fetuses with absent umbilical artery end-diastolic flow (AEDF). Resistance index (RI) was measured from MCA velocity waveforms when AEDF was observed for the first time and at consecutive examinations. Fetal distress defined by fetal heart rate monitoring was found in 19 cases (90%). The difference between MCA RI values of first and last examinations was statistically significant (p < 0.01). There was a positive correlation between MCA RI values at the first examination and the time passing to delivery (r = 0.52; p < 0.05). There was no significant correlation between MCA RI values and the incidence of an adverse perinatal outcome. Pregnancies with AEDF are of high risk for the development of fetal distress. MCA resistance index values decrease gradually in fetuses with AEDF suggesting continuous reduction of cerebral vascular resistance during chronic fetal hypoxia.
Neutrophils from Preterm Neonates and Adults Show Similar Cell Surface Receptor Expression: Analysis Using a Whole Blood Assay
Authors: Falconer A.E. , Carr R. , Edwards S.W.
Published: October 2009

Previous work has shown that Fcγ RIII expression in isolated neonate neutrophils is defective. We have re-examined this phenomenon in view of the facts that (1) the receptor is present on mobilisable subcellular stores and (2) commonly used isolation procedures can affect receptor expression in suspensions of isolated neutrophils. Receptor expression was measured by fluorescence-activated cell sorter analysis of neutrophils in unfractionated whole blood. Examination of receptor expression in preterm, term and adult neutrophils indicated small but significantly decreased expression of CR1 and CR3 in preterm neutrophils compared with term neutrophils (p < 0.01). A small decrease in expression was found for Fcγ RI and Fcγ RIII (p < 0.05). No significant difference in expression of Fcγ RII was observed in all groups analysed. These data suggest that isolated preterm neonate neutrophils have greatly decreased expression of Fcγ RIII because of impaired composition or mobilisation of the subcellular stores of this receptor and/or increased lability of the surface receptor which leads to its shedding during purification.
Differential Expression of α- and β-Thyroid Hormone Receptor Genes in the Developing Rat Brain under Hypothyroidism
Authors: Chattopadhyay Naibedya , Kher Rajesh , Virmani Jyoti , Godbole M.M.
Published: October 2009

One of the most alarming observations of iodine deficiency disorders (IDD) is neurological cretinism which is caused due to lack of T3 during the crucial stages of brain development. We have developed an iodine-deficient rat model to study the pattern of T3 receptor genes expression in the brain during postnatal development under iodine deficiency. We observed increased expression of c-erbA-α2 and –β1 T3 receptor transcripts while c-erbA-α1 remains unchanged in the brain of the iodine-deficient neonates compared with their euthyroid counterparts. Up-regulation of the β1 form in the developing brain under iodine deficiency is suggestive of an adaptive process coming into play to protect it from the damages that are inflicted due to hypothyroidism. Though the significance of the increased α2 form in the iodine-deficient rat brain has not yet been ascertained, it can be conjectured that it acts as a homeostatic control over ‘functional receptor’ (namely β1) under developmental hypothyroidism.
Ketone Body Turnover at Term and in Premature Newborns in the First 2 Weeks after Birth
Authors: de Boissieu D. , Rocchiccioli F. , Kalach N. , Bougnères P.F.
Published: October 2009

Using the infusion of D-(––)-3-hydroxy-[1,2,3,4,-13C4]butyrate at tracer doses, we measured total ketone body turnover in 13 premature and 10 at term infants in the first 2 weeks after birth. The premature infants received parenteral and/or oral feeding. The normal newborns were either recently fed or briefly fasting. The premature and the fed at term infants had comparable concentrations of ketone body (476 ± 86 and 406 ± 78 μmol/l) and free fatty acids (FFA) (309 ± 47 and 325 ± 75 μmol/l). In the premature newborns, ketone body turnover rates (3.2 ± 0.2 μmol kg––1 min––1) were 74% that of fed newborns at term (4.3 ± 0.3 μmol kg––1 min––1, p < 0.05), and 18% that of normal newborns during a brief fast (17.3 ± 1.3 μmol kg––1 min––1, p < 0.01). Ketone body production rates correlated with plasma FFA concentrations in both groups (r = 0.62 and 0.69, p < 0.05). However, for a similar plasma FFA content, ketone production was 2- to 3-fold lower in the premature, indicating an immature hepatic capacity to convert FFA into ketones. Our study therefore shows that ketogenesis is already active in infants born 10 weeks before normal term and continuously fed, but that daily ketone production is lower than at term.
In vitro Model of Human Umbilical Venous Pertusion to Study the Effects of Meconium Staining of the Umbilical Cord
Authors: Pickens James , Toubas Paul L. , Hyde Scott , Altshuler Geoffrey
Published: October 2009

Because meconium diffuses into placental and umbilical cord tissue, its bioactive components are potentially capable of entering the fetal circulation. Meconium diluted in Krebs solution produces vasocontraction in human umbilical vein segments that are suspended in a milieu similar to that of the amniotic cavity. Based on published observations, we wanted to determine if very diluted meconium could induce vasospasm in intact umbilical cords. Human umbilical cords were obtained from full-term deliveries, cut into 2 equal segments, cannulated, and perfused continuously as test and control cords. The study included four parts: (1) intraluminal meconium (n = 6; 0.01-1% solution); (2) 4-hour exposure to 10% meconium-stained amniotic fluid of intact umbilical cords (n = 8); (3) 4-hour exposure to a 10% meconium-stained amniotic fluid of umbilical cords denuded of their epithelial layer (n = 5); (4) 24-hour exposure to a 10% meconium-stained amniotic fluid of intact umbilical cords (n = 9). Significant vasoconstriction of the umbilical vein occurred only with the intraluminal meconium solution exposure (p = 0.034). In this in vitro model meconium staining of the umbilical cord was not associated with vasocontraction of the umbilical vein.
Lipid A Binding to Neonatal and Adult Red Blood Cells
Authors: Pöschl J.M.B. , Schnauffer M. , Galanos C. , Linderkamp O.
Published: October 2009

Lipid A is responsible for the endotoxic activities of gram-negative bacteria. Binding of lipid A (50 μg/ml) to RBC was studied using a passive hemolysis test. RBC from adults, cord and venous RBC from full-term infants and RBC from preterm infants were studied. Lipid A sensitized RBC were hemolysed with anti-lipid A and guinea pig complement. Hemolysis was expressed as hemoglobin concentration (absorbance at 546 nm) in the supernatant after centrifugation. 50 μg/ml lipid A did not increase spontaneous hemolysis ( < 3%) after 60 min of incubation in any of the four groups. The passive hemolysis test did not result in additional hemolysis (5%) of umbilical cord RBC. RBC of preterm infants showed a significant increase in hemolysis (24%) after 60 min of incubation. In RBC of full-term neonates, increased hemolysis (14 and 46%) was detected after 30 and 60 min of incubation. Adult RBC hemolysed stronger (26 and 64%) after 30 and 60 min than neonatal RBC. We conclude that lipid A binds less to neonatal RBC compared to adults.
Ontogeny of Group II Phospholipase A2 Gene Expression in Rat Stomach and Ileum
Authors: Dimberg Jan , Lilja Ingela , Weström Björn , Tagesson Christer , Söderkvist Peter , Gustafson-Svärd Christina
Published: October 2009

Phospholipase A2 (PLA2) activity is important in the gastrointestinal tract, but detailed information about the different PLA2 isoenzymes present in the gastrointestinal mucosa is yet lacking. In the present study, we have investigated the postnatal development of group II phospholipase A2 (PLA2 II) gene expression in the forestomach, glandular stomach, and ileum of neonatal rats. The amounts of PLA2 II mRNA in the glandular stomach increased with age in 15- to 60-day-old rats (i.e. adult animals), whereas the PLA2 II gene expression in the forestomach and ileum increased between 15 and 21 days, but not between 21 days and adults. The PLA2 II gene expression of all three tissues investigated was induced precociously in rats treated with cortisone acetate at days 12, 13 and 14. Taken together, the results indicate that (1) the ontogeny of rat glandular stomach PLA2 II gene expression is similar to the ontogeny previously described for rat glandular stomach group I PLA2; (2) the ontogeny of rat forestomach, glandular stomach and ileal PLA2 II gene expression is related to the glucocorticoid-induced maturation of the rat gastrointestinal tract during the neonatal period, and (3) the ontogeny of PLA2 II gene expression is different in the glandular stomach compared to the ileum and forestomach, which may indicate a different physiological role of PLA2 II and/or a different postnatal maturation, in the glandular stomach.
Relationship between Associations of NOR and Chromosomal Anomalies in the Abnormal Embryos of Nonobese Diabetic and STZ-Diabetic Mouse
Authors: Tatewaki Reiko , Hashimoto Ryuju , Tanigawa Keiichiro , Furuse Kousuke , Tanaka Osamu
Published: October 2009

Associations of nucleolar organizing regions (NORs) in the postimplantation stage embryos of nonobese diabetic (NOD) mice, and diabetic ICR mice induced by streptozotocin (ST), were studied to investigate the possible cause of the numerical anomalies of the chromosomes in their abnormal embryos. The incidence of NOR associations in abnormal embryos from diabetic NOD (NOD-DM) and STZ-diabetic mice was 11.7 and 7.7%, respectively. This incidence was significantly higher than that (1.2%, p < 0.05) of normal embryos from ICR mice which were used as control. From the results analyzed cytogenetically it was suggested that the higher incidence of chromosomal numerical anomalies in the embryos from NOD-DM and STZ-diabetic mice were caused by the chromosomal nondisjunction induced by associations of NORs. Furthermore, it was suggested that NOD-DM embryos have a tendency to increase the associations of NOR in a diabetic condition together with other factors such as autoimmune disease, however a diabetic condition alone induced chromosomal anomalies. Regarding relationships between the incidence of associations of NOR and the types of malformed embryos, it was also clear that all of the abnormal embryos from NOD-DM and STZ-diabetic mice had a high incidence of associations of NOR, and that the incidence was not related to the types of congenital anomalies. Furthermore, in the mal-developed tissue of embryos from STZ-diabetic mice, many chromosomal anomalies were found (26.6%), and the incidence was similar to that of whole embryos (22.6%). Unexpectedly, the incidence of associations of NOR in the maldeveloped tissue was not higher than that of whole embryos. As the results in this study suggest, the numerical anomalies induced by association of NOR seemed to be a causal factor of the disorder of morphogenesis, rather than a resulting phenomenon in abnormal embryos from diabetic mothers.
Amino Acid Oxidation and Urea Production Rates in Fetal Life
Authors: Battaglia Frederick C.
Published: October 2009

Amino acid oxidation and urea production rates are quite different at various stages of development from fetal to adult life. Such information may become increasingly useful in the evaluation of the nutritional state in newborn infants and particularly in very-low-birth-weight infants. A brief commentary on some of the current clinical and basic physiological literature as it relates to amino acid oxidation and urea production is presented. The commentary emphasizes that the literature supports the concept of a higher urea production rate expressed per kilogram body weight in late fetal life as compared with postnatal life. It also discusses some differences for the phases of fetal life, the period of parturition, and the immediate neonatal period.
Closure of Patent Ductus arteriosus Decreases Pulmonary Myeloperoxidase in Premature Infants with Respiratory Distress Syndrome
Authors: Varsila Eeva , Hallman Mikko , Venge Per , Andersson Sture
Published: October 2009

The aim of the study was to determine whether in premature infants with respiratory distress syndrome (RDS), an interrelationship existed between patent ductus arteriosus (PDA) and pulmonary neutrophil content. Thirteen premature infants with PDA (gestational age 26.9 ± 2.4 weeks, birth weight 903 ± 300 g) were pair-matched with infants without PDA (gestations age 27.1 ± 2.5 weeks, birth weight 1,041 ± 430 g) with regard to gestational age, birth weight and severity of RDS. The myeloperoxidase (MPO) contents of tracheal aspirates were analyzed before (age 2.8 ± 1.7 days, MPO I) and after closure of PDA with indomethacin (5.5 ± 1.9 days, MPO II), and at corresponding time points in controls (2.6 ± 1.6 and 4.8 ± 1.8 days). In PDA patients closure of PDA decreased MPO from 14.7 (range 2.1–27.4) to 4.6 (1.2–8.0) μg/mg protein (p = 0.0008), whereas in controls it remained unchanged: 5.4 (2.9–7.8) and 5.3 (2.9–7.8; p = 0.58). A significant difference existed in the change in MPO contents between the infants with PDA and the controls. In premature infants with RDS, closure of PDA decreases the neutrophil content of the lungs. The effect may be caused by closure of PDA as such, or by indomethacin. The high pulmonary neutrophil content in PDA may exacerbate inflammatory processes and contribute to the development of chronic pulmonary disease.
Early Minimal Feedings Promote Growth in Critically III Premature Infants
Authors: Troche Brenda , Harvey-Wilkes Karen , Engle William D. , Nielsen Heber C. , Frantz, III Ivan D. , Mitchell Marvin L. , Hermos Rosalie J.
Published: October 2009

Critically ill premature infants requiring mechanical ventilation and an umbilical artery catheter usually do not receive enteral feedings during the acute phase of their illness. We studied the safety and benefit of early minimal enteral feedings during this time in a prospective, controlled, and randomized study. Twenty-nine infants were randomly assigned to receive only standard intravenous fluid and nutrition (nothing per OS, NPO group; n = 13), or in addition to receive small-volume hypocaloric continuous feedings (1 ml/kg/h), beginning at 24 h of age (early-feeding group; n = 16). Standard enteral feedings were begun in both groups at the resolution of the acute phase of the illness and advanced by protocol. The two groups were of comparable birth weight, gestational age, and Apgar scores. There were no significant differences in the episodes of feeding intolerance. Two infants in the NPO group developed clinical signs of necrotizing enterocolitis. Serum diamine oxidase and somatomedin C were measured weekly until 30-60 days of age and were not different between the two groups. The early-feeding group required fewer days to reach 120 ml/kg/day enteral intake (early-feeding group 10 + 3 days, NPO group 13 ± 4 days; p < 0.05). On day 30 of life the early-feeding group was 223 ± 125 g above birth weight, while the NPO group was 95 ± 161 g above birth weight (p < 0.05). The average intake (kcal/kg/day) from day 6 to day 30 was not different between the two groups. We conclude that early minimal feedings in critically ill very-low-birth-weight infants requiring mechanical ventilation are well tolerated and result in reduced time to reach 120 ml/kg/day of enteral feeding and in a greater weight gain by day 30 of life.
End-Tidal Carbon Monoxide in Newborn Infants: Observations during the 1st Week of Life
Authors: Balaraman Venkataraman , Pelke Susan , DiMauro Stephen , Cheung Steven , Stevenson David K. , Easa David
Published: October 2009

Serial end-tidal carbon monoxide corrected for ambient CO (ETCOc) levels were measured in an ethnically diverse population of 87 normal newborn infants during the first 5 days of life. The results demonstrate a progressive reduction in ETCOc from 1.6 ± 0.4 to 0.8 ± 0.2 ppm. These levels were unrelated to ethnicity, but were inversely related to serum bilirubin levels. We conclude that ETCOc is not a useful indicator for predicting the course of transitional hyperbilirubinemia in the normal newborn infant.