bluuebunny/crossref_metadata_2025 huggingface dataset:
Iron Saturation Alters the Effect of Lactoferrin on the Proliferation and Differentiation of Human Enterocytes (Caco-2 Cells)
Authors: Oguchi Satoshi , Walker Allan , Sanderson Ian R.
Published: October 2009

Recent studies have indicated that lactoferrin may act as a cell mitogen. The effect of human and bovine lactoferrins on the proliferation and differentiation of a human intestinal epithelial cell line (Caco-2) was investigated and compared with that of human transferrin. Caco-2 cells were cultured in serum-free media supplemented with both iron-unsaturated and -saturated forms of the iron-binding proteins. Cell proliferation and differentiation were evaluated by examining growth curves and measuring sucrase and alkaline phosphatase activities of brush border membrane fractions, respectively. The iron-binding status of lactoferrins and transferrin affected the proliferation of Caco-2 cells. The iron-saturated forms of human (S-hLf), bovine (S-bLf) lactoferrins and human transferrin (S-hTf) enhanced cell proliferation, while iron-unsaturated forms (U-hLf, U-bLf, and U-hTf) suppressed it. Iron-binding status also determined the effect of lactoferrin and transferrin on cellular differentiation, but this effect differed for different brush border enzymes. S-hTf enhanced sucrase activity more than S-hLF or S-bLf. Both U-hLf and U-bLf markedly suppressed sucrase activity. U-hTf suppressed alkaline phosphatase activity appreciably, while the other iron-binding proteins showed no significant effect on it. Lactoferrin and transferrin may modulate the proliferation and differentiation of intestinal epithelial cells, but their efficacy depends on their saturation with iron.
A Portable Device for Estimating the Rate of CO2 Production in Preterm Infants
Authors: Kien Lawrence , Murray Robert D. , Knerr Tamara L. , McClead Richard E. , Cordero, Jr. Leandro
Published: October 2009

We developed a simple flow-through system for measuring the net rate of pulmonary excretion of CO2 (VCO2). Its components, connected in series by plastic tubing, are the following: plastic oxygen hood, suction flask used both as a mixing and sampling chamber, Brooks mass flow controller, and wall suction. Gas aliquots withdrawn from the sampling flask are analyzed for CO2 concentration in the laboratory. The system was validated by measuring over a 60-min period the evolution of CO2 from the reaction of sodium carbonate with phosphoric acid. In 9 trials, the mean recovery of CO2 was 99.8%. In 14 studies in 11 preterm infants, we evaluated the reproducibility of duplicate measurements of CO2 production on consecutive days; in 9 of the studies, the coefficient of variation was < 5%, but in other 5 studies, it ranged from 7.7 to 35.8%. We believe that this device might have both research and clinical applicability.
Renal Blood Flow Velocity in Non-Distressed Preterm Infants during the First 72 Hours of Life
Authors: van de Bor Margot
Published: October 2009

Renal blood flow velocity (RBFV) was studied with two-dimensional/pulsed Doppler ultrasound in 28 non-distressed very preterm infants (mean ± SD gestational age was 27.3 ± 2.1 weeks and birth weight 907 ± 214 g) at 6, 12, 24, 36, 48, and 72 h of age. Mean arterial blood pressure (MABP), PaCO2, PaO2, and Hct were determined simultaneously. Mean RBFY increased significantly from 14.5 ± 1.9 cm/s at 6 h to 20.2 ± 2.5 cm/s at 72 h (p < 0.005). MABP decreased slightly though significantly between 6 h (36.5 ± 1.8 mm Hg) and 12 h (34.3 ± 1.5 mm Hg), but rose thereafter to significantly higher values at72h(41.4 ± 1.3 mm Hg). Renal vascular resistance (RVR = MABP/RBFV) decreased rapidly during the first day of life (2.6 ± 0.1 mm Hg/cm·s––1 at 6 h vs. 2.0 ± 0.05 mm Hg/cm·s––1 at 24 h). In conclusion, RBFV increases whereas RVR decreases during the first days of life.
Effects of Epinephrine on the Cardiorespiratory Response to Hypoxia in Sedated Newborn Piglets with Intact and Denervated Carotid Bodies
Authors: Suguihara Chide , Hehre Dorothy , Bancalari Eduardo
Published: October 2009

In order to evaluate the effects of epinephrine on the cardiorespiratory response to hypoxia in the neonate, 35 sedated, spontaneously breathing newborn piglets (X ± SD, age 5 ± 0.8 days; weight 1.6 ± 0.3 kg) with intact (ICB) or denervated (DCB) carotid bodies were studied before and during an infusion of saline or epinephrine (2.2 ± 1.0 μg/kg/min, i.v.). Cardiorespiratory measurements were performed while the animals breathed room air and after 10 min of hypoxia (FiO2 0.10) during saline or epinephrine infusion. During epinephrine infusion, the ICB animals had a sustained increase in minute ventilation during hypoxia while the control group showed a biphasic ventilatory response with depression during sustained hypoxia. After the chemodenervation, the ventilatory response to hypoxia was completely blunted in saline and epinephrine animals. In the ICB and DCB animals, the arterial blood pressure decreased significantly with hypoxia during epinephrine infusion, while cardiac output increased significantly in all ICB and DCB saline animals. The oxygen consumption (VO2) decreased significantly after 10 min of hypoxia in all groups except in the ICB epinephrine animals, in whom the VO2 did not change with hypoxia. In conclusion, the administration of epinephrine to newborn piglets reverses the depressed ventilatory response to hypoxia and this effect requires the activity of the peripheral chemoreceptors.
Effects of Yersinia enterocolitica Infection on Growth of the Body and Internal Organs in Newborn Colostrum-Deprived Piglets
Authors: Shu D. , Simpson H.V. , Xu R.-J. , Mellor D.J. , Reynolds G.W. , Marshall R.B.
Published: October 2009

Yersinia enterocolitica enteritis in newborn, colostrum-deprived piglets fed a human milk formula caused a reduced milk intake and decreased gain in weight but not length of the body. In infected piglets, the weight of the liver was less than in controls but other abdominal organs were unaffected. The weight of the caecum and small intestinal muscle were greater, but the length and weight of the small intestine and colon were not different. In infected piglets, the RNA concentration of the small intestinal mucosa was elevated whereas the concentrations of DNA and protein were unchanged, and total lactase activity was reduced. After antibiotic therapy, the liver weight was greater and the body weight increased at the same rate as the controls but was still lower at 14 days. The body weight of the control piglets increased linearly over the 14 days after birth. The stomach, pancreas and spleen grew more rapidly, but the liver more slowly, than the body as a whole but the kidneys had a minimum relative weight at 5 days. The total lactase activity and protein and RNA concentrations of the small intestinal mucosa decreased with age, the RNA to a greater extent than the protein.
Developmental Factors in the Contractile Response of Rabbit Urinary Bladder: Effect of Anoxia and Extracellular Acidosis
Authors: Yoon Jai-Young , Zderic Stephen A. , Duckett John W. , Snyder, III Howard M. , Levin Robert M.
Published: October 2009

Previous studies have demonstrated that the mechanism of excitation contraction coupling changes with normal development in rabbit urinary bladder smooth muscle. The present study was designed to determine whether there were any differences in the effects of anoxia and extracellular acidosis in response to field stimulation, bethanechol and KCl between mature (8 weeks) and neonatal (3 days) rabbit bladder smooth muscle. Bladder smooth muscle strips from mature and neonatal New Zealand White rabbits were mounted in organ baths and bathed in oxygenated Tyrode’s solution. Anoxia was produced by changing the gas mixture to 95% nitrogen/5% CO2 and the effects on contractility were determined at different times after initiation of anoxia. The extracellular acidosis was produced by decreasing the buffer’s NaHCO3 concentration. We conclude that bladder smooth muscle does not exhibit an age-specific ability to counteract the effects of anoxia or acidosis as is seen in the developing rabbit myocardium. Instead it appears that the purinergic mechanisms of contraction are much more sensitive to the effects of anoxia or acidosis. Neonatal bladder smooth muscle exhibits a greater drop in contractility with anoxia or acidosis at low frequency (2 Hz) field stimualtion; we attribute this to the fact that neonatal bladder smooth muscle has a greater purinergic component in its response to field stimulation. These differences in the responses to anoxia and pH reflect alternate mechanisms of pharmacologic activation, and not inherent differences in the biochemistry of the maturing smooth muscle.
Examination for Toxicity of a Chinese Drug, the Toad Glandular Secretory Product Chan Su, in Pregnant Mice and Embryos
Authors: Chan W.Y. , Ng T.B. , Yeung H.W.
Published: October 2009

In order to evaluate the developmental toxicity and teratogenicity of a Chinese drug, the toad venom Chan Su, the drug was administered in a single intraperitoneal injection to pregnant ICR mice during the period of embryonic organogenesis. At the end of the gestation period, the mice were sacrificed, and the fetuses were collected, fixed and sectioned. A dose of Chan Su lower than 50 mg (dry weight)/kg body weight did not produce detectable changes in the recipient mice, but at a dose of 50 mg/kg the drug induced a decrease in body weight and structural abnormalities in livers and kidneys of the pregnant mice as well as increases in the number of resorbed and dead fetuses. There was a reduction in fetal weight although there were no changes in fetal crown-rump length nor tail length. No abnormalities were observed in the fetuses.
Changes in Serum Lipid, Lipoprotein and Corticosterone Concentrations during Neonatal Chick Development
Authors: Latour Mickey A. , Peebles Edgar D. , Boyle Carolyn R. , Brake Julian D. , Kellogg Thomas F.
Published: October 2009

Broiler chicks were given a standard commercial starter diet from day 0 (day of hatch) to 9 days of age. Body weight and concentrations of the following serum constituents were measured daily: glucose (GLU), triglycerides (TRI), corticosterone (CORT), cholesterol (CHOL), and high (HDL) and low (LDL) density lipoproteins. Serum GLU and TRI increased at each sampling day to reach a peak on days 3 and 4, respectively, and then decreased thereafter. However, CHOL, HDL, and LDL decreased sharply by day 1 and then gradually decreased to day 5. Conversely, CORT peaked on day 1 and then decreased to day 4. It peaked again on day 5 and remained at that level throughout the remainder of the experiment. In summary, serum concentrations of all constituents measured fluctuated drastically between 1 and 5 days of age, with few changes occurring between days 6 and 9.
Responsiveness to the Odour of Amniotic Fluid in the Human Neonate
Authors: Schaal Benoist , Marlier Luc , Soussignan Robert
Published: October 2009

Two-day-old newborns were videotaped during a double-choice test contrasting the odours of their amniotic fluid (AF) and of a control stimulus. To control for early motor asymmetries, the lateral position of both stimuli was balanced both between and within subjects. On average, neonates oriented their nose for a significantly longer duration toward the odour of AF. Regardless of the nature of the stimulus, neonates also evinced a marked head-turning bias to the right side. The nature of the odour stimulus and side of presentation interacted so that infants turned their nose longer to the AF odour when it was presented from the right side. These data indicate that newborns can detect the AF odour, and that they remain attracted towards it for at least 2 days after birth.
Monoamine Neurotransmitters and Metabolites in the Cerebrospinal Fluid following Perinatal Asphyxia
Authors: Blennow Mats , Zeman Jiri , Dahlin Ingrid , Lagercrantz Hugo
Published: October 2009

While the release of neurotransmitters is involved in the pathophysiology of brain damage following birth asphyxia, it also plays a role in endogenous defense against such damage. Levels of monoamines and the main cerebral monoamine metabolites in the cerebrospinal fluid (CSF) were measured in asphyxiated and control infants within 24 h after birth. The results indicate an increased turnover of noradrenaline (NA) and dopamine following asphyxia. Furthermore, the NA stores in the brain seem to be exhausted in some cases. We conclude that this increase in catecholamine turnover to some extent explains the clinical symptoms of hypoxic-ischemic encephalopathy and that it may reflect an intrinsic adaptive capacity to perinatal distress.
Influence of Early Feeding Mode on Body Composition of Infants
Authors: Butte Nancy F. , Wong William W. , Fiorotto Marta , O’Brian Smith E. , Garza Cutberto
Published: October 2009

To determine the effect of infant feeding mode on body composition, a cross-sectional study was designed in which 10 breast-fed and 10 formula-fed infants were studied at 1 month of age, and another 10 breast-fed and 10 formula-fed infants at 4 months of age. Anthropometric measurements included body weights, lengths, selected diameters, circumferences and skinfold thicknesses. Total body water (TBWO) was measured by 18O dilution. A dose equivalent to 300 mg 180/kg body weight was administered orally to the infants. Fat-free mass (FFMo) was calculated from TBWo using reference hydration constants of 0.805 and 0.798 at 1 and 4 months, respectively. Body fato was taken as the difference between weight and FFMo. Total-body electrical conductivity (TOBEC) measurements were used to estimate FFMT anf fatT ANOVA was used to analyze the anthropometric and body composition data using feeding mode and age as grouping factors. Anthropometric measurements did not differ by feeding mode. TBW (kg) and FFM (kg) and body fat (kg) derived from 180 dilution or TOBEC did not differ by feeding mode. TBWO, T (%wt), FFMO, T (%wt), and body fatO.T (%wt) derived from 180 dilution and TOBEC differed significantly between the breast-fed and formula-fed infants at 4 months of age (p < 0.05). Expressed as a percentage of body weight, TBWO and FFMOT were higher and body fatO, T was lower among the 4-month formula-fed infants.
Effect of Nordihydroguaiaretic Acid on Cerebral Blood Flow and Metabolism during Hypoxia in Newborn Piglets
Authors: Goplerud Jan M. , McGowan Jane E. , Marro Peter J. , Delivoria-Papadopoulos Maria
Published: October 2009

Nordihydroguaiaretic acid (NDGA), a lipoxygenase inhibitor, was investigated for its effect on cerebral blood flow (CBF) and cortical oxygen consumption during hypoxia in 9 anesthetized, ventilated newborn piglets. CBF was measured by radioactive microspheres while brain cortical metabolism was evaluated by continuous 31P-NMR spectroscopy. Five piglets were treated with NDGA (3 mg/kg i.v. in 50% ethanol as vehicle) prior to hypoxia and had CBF measured before NDGA (control), 15 min after NDGA (baseline) and then after 15 and 45 min of hypoxia following NDGA. Another 4 piglets were treated with vehicle (2 ml/kg 50% ethanol) under the same protocol. In the NDGA-treated piglets, cerebral cortical O2 consumption for a given PCr/Pi was significantly increased (p < 0.05) compared to non-NDGA. Since NDGA inhibits production of vasoconstricting leukotrienes during hypoxia, cortical capillary beds otherwise constricted may be perfused following NDGA, thus increasing the O2-consuming tissue area.
Ethanol, Morphine and Barbiturate Alter the Hemodynamic and Cerebral Response to Cocaine in Newborn Pigs
Authors: Albuquerque Maria Luiza C. , Kurth Dean , Monitto Constance L. , Shaw Leslie , Anday Endla K.
Published: October 2009

Newborns delivered to cocaine-abusing mothers are often exposed to other concurrently consumed illicit drugs, which may alter the hemodynamic and cerebral response to cocaine. This study examined the interaction of ethanol, morphine or barbiturate with cocaine on mean arterial pressure (MAP), cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) in newborn pigs. CBF, CMRO2 and cerebral O2 extraction (CECO2) were measured before and 4 and 10 min after cocaine (1.5 mg/kg i.v.) was administered in piglets that were awake, or pretreated with morphine, ethanol or pentobarbital. In awake piglets, cocaine increased CMRO2 and CEO2 while it had no significant effect on CBF. Conversely, in morphine- and ethanol-pretreated piglets, cocaine decreased CMRO2, decreased CBF and had not effect on CEO2. In awake piglets, cocaine increased MAP, whereas in morphine- or ethanol-pretreated piglets, cocaine decreased MAP. In the pentobarbital group, cocaine had no effect. These data demonstrate that other drugs of abuse alter the hemodynamic and cerebral effects of cocaine in the immature animal and may contribute to the central nervous system abnormalities in ‘crack babies’.
Signaling Pathways Regulating Ornithine Decarboxylase Activity in the Embryonic Chicken
Authors: Shibley, Jr. Ivan A. , Pennington Sam N.
Published: October 2009

The pathways regulating ornithine decarboxylase (ODC) activity in the chick embryo were studied to determine which kinase-signaling pathways regulate ODC activity levels during development. Insulin-dependent tyrosine kinase, protein kinase C and cAMP-dependent protein kinase were activated by the addition of insulin, tetradecanoylphorbol-12,13-acetate, and forskolin, respectively. All three drugs increased ODC activity and forskolin combined with insulin increased ODC activity above the increase caused by either drug alone. These results suggest that all three signaling pathways regulate ODC activity during development and that common intermediates exist among the pathways downstream of the kinases.
Failure of Immunoglobulins to Prevent Neonatal Thrombocytopenia in Mothers with Immunothrombocytopenic Purpura
Authors: Zuppa Antonio Alberto , Tornesello Assunta , Mastrangelo Renato
Published: October 2009

We report the case of a full-term (gestational age: 39 weeks) female newborn of a mother affected by immunothrombocytopenic purpura, treated with a high total dose (2 g/kg) of intravenous IgG, administered over a 3-day period starting 3 days before delivery. Infant platelet count at birth was 20,000/ mm3 and she showed a great number of petechiae on the first day of life. After a random donor platelet transfusion and treatment with intravenous high-dose IgG (400 mg/kg for 5 days), platelet count began to increase. We conclude that exogenous IgG, even at high concentrations, apparently does not significantly cross the placenta, despite adequate maternal blood levels.
Potential Role of Surfactant Proteins A and D in Innate Lung Defense against Pathogens
Authors: van Golde Lambert M.G.
Published: October 2009

The physiological role of pulmonary surfactant is probably not limited to conferring mechanical stability to the alveoli. Increasing evidence suggests that surfactant components, in particular the hydrophilic surfactant proteins SP-A and SP-D, play potentially important roles in host defense mechanisms. Both SP-A and SP-D are collagenous C-type lectins (collectins) that are structurally and, perhaps, functionally related to collectins in the circulation. As will be discussed in this review, evidence is accumulating that the alveolar collectins SP-A and SP-D could be important components of a first-line defense system against infiltrating pathogenic micro-organisms and viruses.
Pathophysiology and Treatment of Surfactant Protein-B Deficiency
Authors: Hamvas Aaron , Nogee Lawrence M. , deMello Daphne E. , Cole Sessions
Published: October 2009

Surfactant protein B (SP-B) deficiency is an inherited disease of full-term newborn infants which leads to lethal respiratory failure within the first year of life. Genetic analysis of affected infants has permitted identification of a mutation in the SP-B gene found in several unrelated kindreds which disrupts pulmonary surfactant composition and function. Lung transplantation has resulted in reconstitution of pulmonary surfactant function and long-term survival. SP-B deficiency represents the first opportunity to link physiologic characteristics of respiratory failure in infancy with specific molecular and cellular defects. This linkage will facilitate development of novel strategies for the treatment of neonatal respiratory diseases.
Factors Influencing Efficacy of Exogenous Surfactant in Acute Lung Injury
Authors: Lewis Jim F. , Veldhuizen Ruud A.W.
Published: October 2009

Exogenous surfactant is currently being tested as a therapeutic modality for patients with acute respiratory distress syndrome (ARDS). Animal studies have shown that several factors may influence the efficacy of this treatment modality. These factors include the surfactant delivery method used (instillation vs. aerosolization), the timing of surfactant treatment over the course of injury, the specific surfactant preparation used, and the dose of surfactant administered. Each of these factors alone and together may influence the interaction of the exogenous surfactant with the host’s alveolar environment. This, in turn, may dictate how a specific patient responds to a particular surfactant treatment strategy. It is suggested that patients at an early stage of lung injury will benefit from aerosolized exogenous surfactant whereas large quantities of an instilled exogenous surfactant may be necessary at later stages of injury. Future studies will clarify how a specific surfactant treatment strategy should be chosen for an individual patient with ARDS.
Phagocytosis-Promoting Factor in Human Colostrum
Authors: Straussberg R. , Sirota L. , Hart J. , Amir Y. , Djaldetti M. , Bessler H.
Published: October 2009

The effect of colostrum of mothers of preterm and full-term newborns on the phagocytic activity for latex particles by normal peripheral blood polymorphonuclear cells was examined. The results showed that human colostrum contains a phagocytosis-promoting factor(s), which not only increases the number of phagocytic cells, but also stimulates the phagocytic activity of the individual cell. This factor(s) was more active in preterm colostrum. Thus, while term colostrum increased the number of phagocytic cells by 95% in comparison with the control, preterm colostrum enhanced the number of phagocytic cells by 300%. Similarly, term colostrum increased the phagocytic capacity of the individual cell by 51%, whereas preterm colostrum by 137%. The difference between the results in all experimental points was statistically highly significant.
Hepatic Biotransformation Capacity in Low-Birth-Weight Infants as Measured with the [15N]Methacetin Urine Test: Influences of Gestational Age, Postnatal Age, and Intrauterine Growth Retardation
Authors: Boehm Günther , Teichmann Barbara , Krumbiegel Peter
Published: October 2009

The influences of the gestational age (range: 28-36 weeks) and the postnatal age (range: 6–100 days) on the biotransformation capacity of the liver were studied in 51 preterm appropriate-for-gestational-age infants and in 20 preterm small-for-gestational-age infants using the [15N]methacetin urine test. Methacetin is a test drug assessing a two-step pathway of biotransformation including monooxygenation and conjugation. After oral administration of 3 mg [15N]methacetin/kg body-weight, the cumulative 15N excretion in urine during the consecutive 9 h was measured and used as a marker of microsomal biotransformation capacity. In preterm appropriate-for-gestational-age infants, the biotransformation capacity increases with gestational age as well as with postnatal age, but the strongest correlation could be found between cumulative [15N] excretion and postmenstrual age. Intrauterine growth retardation results in lower biotransformation capacity (26.3 ± 11.3 vs. 36.1 ± 9.6% [15N] excretion, expressed as percentage of intake) and disturbed postnatal development of this hepatic function. The data indicate that normal intrauterine development is a prerequisite for normal postnatal development of the biotransformation capacity, which might have consequences for the metabolism and efficacy of certain drugs in small-for-gestational-age infants.
Effects of Epidermal Growth Factor on Glucose Metabolism in Neonatal Rats
Authors: Sato Yasushi , Hiramatsu Yuji , Kudo Takafumi
Published: October 2009

Epidermal growth factor (EGF) may play a key role in fetal growth. We have investigated the effects of EGF on glucose metabolism, the main source of energy during the early neonatal period. When compared to control, EGF treatment increased hepatic glycogen, plasma insulin, and the proportion of B cells in the islets of Langerhans, but decreased the concentration of plasma glucagon. Thus, the insulin-to-glucagon molar ratio in plasma was increased in the EGF-treated group. These data suggest that EGF shifts glucose metabolism from catabolism towards anabolism during the early neonatal period by controlling the pancreatic endocrine system. This effect may help the neonate in adapting to the extrauterine environment after birth.
Effects of Maternal Administration of Dexamethasone and Thyrotropin-Releasing Hormone on Fetal Rat Pulmonary Surfactant Synthesis
Authors: Yokoyama Naoki , Takada Satoshi , Uetani Yoshiyuki , Nakamura Hajime
Published: October 2009

To determine the effects of maternal administration of dexamethasone (DEX) and thyrotropin-releasing hormone (TRH) on fetal lung maturation, 16 pregnant rats were divided into the following four groups: 20 μg/kg TRH twice a day was given intraperitoneally to the TRH group rats, 0.5 mg/kg/day DEX to the DEX group and both DEX and TRH to the DEX + TRH group for 3 consecutive days from gestational day 17. The control rats were given an equivalent volume of saline. The pregnant rats were sacrificed on gestational day 20 and the fetal lungs were removed. The relative amounts of surfactant protein A (SP-A), B (SP-B) and C (SP-C) mRNAs were analyzed by Northern blotting and the total lung disaturated phosphatidylcholine (DSPC) contents were determined using an enzymatic method. The SP-B and -C mRNA and DSPC contents in the DEX and DEX + TRH groups were significantly higher than those in the control group, whereas the SP-A mRNA levels did not differ significantly among the four groups. The SP-B and -C mRNA and DSPC contents in the DEX and DEX + TRH groups did not differ significantly. These findings suggest that TRH has no effects on the regulation of surfactant protein mRNAs or DSPC contents in the fetal rat lung and has no additive effects when combined with DEX.
Dendritic Branching of Claustral Neurons in Neonatally Undernourished Rats
Authors: Escobar Carolina , Salas Manuel
Published: October 2009

Golgi-Cox-impregnated neurons of the claustrum were studied in control and undernourished Wistar strain rats at 12, 20, and 40 days of age. A reduced cross-sectional somatic area was observed in the 20-day-old undernourished rats and a significant reduction in the dendritic area was observed in the three ages studied. Dendritic arbor alteration was mainly observed in the number of high order and in the total number of dendritic branches of undernourished rats throughout the study. The data suggest vulnerability of the dendritic claustral growth process during the postnatal period to neonatal undernutrition. These alterations may be associated with telencephalic integrative impairments described in perinatal undernourished rats.
Serum Amino Acid Concentrations in Growing Rats Fed Intact Protein versus Enzymatic Protein Hydrolysate-Based Diets
Authors: Baró Luis , Guadix Emilia M. , Martínez-Augustin Olga , Boza Julio J. , Gil Angel
Published: October 2009

The aim of this study was to evaluate the effect of the molecular form of dietary protein (native or enzymatically hydrolyzed) on the total serum protein concentrations and the serum amino acid profile of growing rats at weaning. Wistar male rats at weaning were randomly assigned to one of the four isocaloric and isonitrogenous (12% protein equivalent content) diets and fed for 7 days. The protein sources of the diets were: whey protein, casein and their respective hydrolysates. Differences in the serum amino acid profiles exclusively related to the amino acid composition of the protein (casein or whey proteins) were observed, but differences due to their molecular form were not observed. It is concluded that the use of enzymatic hydrolysates of whey proteins and casein has the same effects as their native proteins on nitrogen intake, body weight gain and serum amino acid profile of growing rats at weaning.
Somatostatin in Preterm Infants: Postnatal Changes and Response to Stress
Authors: Jain Lucky , DelValle John , Gelhar Debra , Levy Paul , McCulloch Kristine , Vidyasagar D.
Published: October 2009

To determine the chronology of postnatal somatostatin (SRIF) changes in preterm infants and the relationship of SRIF levels to respiratory and gastrointestinal complications, we evaluated sequential SRIF levels in 62 preterm infants in the first month of life. Weekly preprandial plasma samples were obtained and analyzed for SRIF using a radioimmunoassay. Additional blood samples were obtained at the time of abdominal events. Somatostatin levels were highest in week 2 and gradually declined in weeks 3 and 4 (mean ± SD pmol/l, SRIF = 92.3 ± 30.3 in week 2 vs. 79.8 ± 33.9 in week 3 and 69.7 ± 54.4 in week 4, p < 0.03). Birth weight, gestational age and sex were not related to initial SRIF levels. Infants with respiratory distress requiring assisted ventilation had significantly higher week 1 SRIF levels compared to infants without respiratory problems (97.9 ± 22.7 vs. 74.9 ± 21 pmol/l, p < 0.02). Twenty-one of the 62 infants had gastrointestinal complications. Somatostatin levels preceding (89.0 ± 25.9 pmol/l), during (91.0 ± 13.3) and after (79.3 ± 28.6) the gastrointestinal events were not significantly different, nor were they different from SRIF concentrations of age-matched preterm infants without gastrointestinal complications. The results suggest that in preterm infants, postnatal SRIF changes follow a definite pattern with peak concentrations in week 2. Respiratory distress is associated with a significant increase in SRIF. However, subsequent gastrointestinal events do not lead to an increase in SRIF. This lack of SRIF response in gastrointestinal stress may play a role in the pathogenesis of gut injury in the premature neonate.
Acute Effects of Indomethacin on Cerebral Hemodynamics and Oxygenation
Authors: Benders Manon J.N.L. , Dorrepaal Caroline A. , van de Bor Margot , van Bel Frank
Published: October 2009

Although an indomethacin-induced decrease of brain perfusion in preterm infants has been well established, the acute effects of this vasoactive drug on cerebral hemodynamics and oxygenation are not well documented. Using near infrared spectroscopy we monitored in 6 very preterm infants changes in cerebral blood volume (ΔCBV) and cytochrome oxidase concentration (ΔCytaa3), used as relative measures of changes in brain perfusion and as an indicator for cellular oxygenation of brain tissue, during and up to 1 h after indomethacin infusion. ΔCBV showed a quick blood-pressure-related increase as compared to baseline (preindomethacin values) during indomethacin infusion (averaged maximal increase 13%), followed by a sharp decrease below baseline values (averaged maximal decrease 24%). There was a sustained recovery to baseline during the registration period. ΔCytaa3 showed a small, early increase in 4 of 6 babies, followed by a substantial decrease below baseline in 5 babies. ΔCytaa3 showed only a partial recovery in those 5 babies during the study period. We conclude that a therapeutic dose of indomethacin may cause substantial swings in brain perfusion and a marked and rather longstanding decrease in Cytaa3, suggesting a decrease in cellular oxygenation of brain tissue. Awareness of these effects may be important in sick preterm babies during periods of pulmonary and cardiac instability.
Maternal and Neonatal Plasma Cytokine Levels in Relation to Mode of Delivery
Authors: Buonocore Giuseppe , De Filippo Marcello , Gioia Dino , Picciolini Enrico , Luzzi Enrico , Bocci Velio , Bracci Rodolfo
Published: October 2009

After birth, host defences must be recruited to manage the transition from an almost sterile to a normal environment. The present study was undertaken to evaluate the relationship between cytokine plasma levels and phagocyte burst in mothers and neonates during the peripartal period. Plasma levels of interleukin (IL)-1 IL-6, tumour necrosis factor (TNF)-α interferon (IFN)-γ and granulocyte-macrophage colony-stimulating factor (GM-CSF) and whole blood superoxide anion (●O2) generation were evaluated in 27 healthy mothers, 16 undergoing vaginal delivery (VD) and 11 elective caesarean section (ECS) and in their babies. Blood specimens were taken from the mothers at the beginning of labour, during labour, immediately after delivery and 4 days later in the VD group, and before anaesthesia, immediately after delivery and 4 days later in the ECS group; neonatal samples were taken at birth (cord blood) and 4 days later. After delivery by VD, these mothers had higher plasma levels of IL-1β, IL-6, IFN-γ and higher ●O2 generation than those delivered by ECS. IL-6 plasma levels and ●O2 generation were higher in babies born by VD than in those born by ECS. A statistically significant correlation between IL·6 plasma levels and ●O2 release was observed in cord blood of babies born by VD (r = 0.69; p < 0.006). The study demonstrates that labour plays an important role in modulating host defences in the newborn.
Ontogeny of Rat Myocardial A1 Adenosine Receptors
Authors: Cothran Donna L. , Lloyd Thomas R. , Taylor Heidi , Linden Joel , Matherne Paul
Published: October 2009

Adenosine functions as a counterregulatory hormone in the myocardium by decreasing work and thereby protecting the myocardium against ischemia. Functional adenosine A1 receptors could serve as an important regulatory system in the developing preinnervated heart by balancing the humoral sympathetic input to the heart. The aims of this study were to determine if A1 adenosine receptors were functionally coupled to their Gi protein in the immature preinnervated heart and to determine if A1 adenosine receptors were present in greater numbers in the immature heart. One- to 3-day-old rat ventricular cardiomyocyte cultures were exposed to (1) control conditions; (2) isoproterenol, a β-receptor agonist; (3) R-PIA, an A1 agonist, or (4) isoproterenol and R-PIA. cAMP levels were determined by RIA in each group. Adenosine A1 receptor density and the equilibrium dissociation constant were determined by binding of an adenosine At receptor antagonist in newborn, 1-week-old, 2-week-old, and adult rat hearts. A1 stimulation decreased the isoproterenol-induced increase in cAMP by 30%, demonstrating functional A1 receptors in immature preinnervated myocytes. The A1 receptor density in the newborn age group was twice the adult and 2-week-old level. We conclude that A1 receptors in the immature heart are functionally coupled to their effector and that A1 receptors are present in greater numbers in the immature heart.
Lipoprotein Lipase Activity in Developing Rat Brain Areas
Authors: Nuñez Montserrat , Peinado-Onsurbe Julia , Vilaró Senén , Llobera Miquel
Published: October 2009

Lipoprotein lipase (LPL) is a key extracellular enzyme that enables tissue to import fatty acids from triacylglyceride-rich lipoproteins. LPL is present in most tissues of the body, but in the brain its functional significance remains unclear. Lipids constitute the main components of myelin and undergo significant changes during maturation. However, nothing is known of the postnatal evolution of LPL activity in the brain areas during postnatal development. Here we found that LPL activity is relatively high in the newborn brain and peaks between the 5th and the 10th days after birth, reaching activities 5 times higher than in the adult brain. In all the areas studied (olfactory bulbs, cortex, thalamus, cerebellum, hippocampus, striatum, brain-stem and spinal cord) LPL also increases sharply during postnatal development. Hippocampus shows the highest LPL activity levels, which are between 5 and 11 times higher than in the other regions. The significance of these high LPL activity levels is discussed.
Rates of Bilirubin Clearance from Rat Brain Regions
Authors: Ruud Hansen Thor Willy , Cashore William J.
Published: October 2009

The mechanism for the preferential distribution of bilirubin to basal ganglia (‘kernicterus’) is unknown. We hypothesized that differences in bilirubin clearance rates between brain regions might explain this phenomenon. Bilirubin [30mg/kg over 5 min, with 370-740 kBq (10-20 μCi) tritiated bilirubin] was infused into a peripheral vein in unanesthetized, young Sprague-Dawley rats (n = 36, weight 149 ± 15 g, mean ± SD). After blood sampling, groups of rats were killed at 15, 30, 45, 60, 75, 180, and 360 min with an intravenous injection of pentobarbital. Brain vasculature was flushed in situ and brains dissected into seven regions, which were weighed, dissolved and scintillation counted. Blood was analyzed for bilirubin, albumin, and blood gases. Brain bilirubin concentrations were calculated after determining the specific activity of bilirubin in serum at the time of sacrifice. Bilirubin half-lives in serum and brain regions were (in minutes, mean ± SD): serum 24.6 ± 17.2, whole brain 18.5 ± 21.5, cortex 17.6 ± 19.3, hippocampus 19.0 ± 21.5, striatum 17.1 ± 18.5, midbrain 16.3 ± 18.6, hypothalamus 17.4 ± 21.0, cerebellum 21.6 ± 33.8, medulla 20.0 ± 24.1. There were no significant differences in bilirubin half-lives between regions. The half-life of bilirubin in brain reported here is appreciably shorter than the 1.7 h previously found in rats with opened blood-brain barriers, but appears compatible with data on auditory brainstem response reversibility following exchange transfusion in jaundiced infants. We conclude that bilirubin disappeares rapidly from brains with intact blood-brain barriers. The rates of clearance found in different brain regions in this model cannot explain the kernicterus phenomenon (i.e. preferential staining of basal ganglia and cerebellum).
Biochemical and Morphological Changes in the Developing Kidney
Authors: Kahane Veronica L. , Cutrín Juan C. , Setton Clara P. , del Carmen Fernández Maria , Catz Sergio D. , Sterin-Speziale Norma B.
Published: October 2009

We have studied microsomal phospholipid, cholesterol and protein concentration in rat renal papilla, medulla and cortex during postnatal development, and the relationship between these membrane biochemical parameters and morphological changes. We also determined DNA concentration in each kidney zone. No changes were observed either in papillary microsomal phospholipids, proteins and cholesterol or in DNA concentration from 10- to 70-day-old rats. Medullary microsomal proteins and cholesterol did not change but a significant increase was observed in the microsomal phospholipid concentration during development; in this case, medullary DNA was significantly lower at 70 than at 10 days. In contrast, all biochemical parameters in renal cortex were significantly higher during development except for DNA concentration which suffered a great decrease. These biochemical findings agree with the morphological changes observed. Our results demonstrate that the developmental pattern is different in each zone of the kidney and confirm the fact that the papilla, in newborn rats, is almost fully developed whereas the renal cortex and medulla are immature.
Intrathecal Immune Response in Neonatal Flavobacterium meningosepticum Meningitis
Authors: Abrahamsen Tore G. , Mollnes Tom E. , Vandvik Bodvar
Published: October 2009

Neonates are predisposed to serious infections such as meningitis, probably due to their immature host reaction to the pathogens. We have studied the intrathecal immune response in 2 newborns with Flavobacterium meningosepticum meningitis. They showed a significant elevation of immunoglobulin indices (> 1.0), also after the CSF had become sterile with a normalized cell count. In addition, an intrathecal increase and subsequent decrease of both C3dg and TCC (terminal complement complex) were observed in 1 patient. We conclude that immunoglobulin production and complement activation may occur in neonatal CSF.
Umbilical Vein Pulsations and Acid-Base Status at Cordocentesis in Growth-Retarded Fetuses with Absent End-Diastolic Velocity in Umbilical Artery
Authors: Rizzo Giuseppe , Capponi Alessandra , Soregaroli Mirella , Arduini Domenico , Romanini Carlo
Published: October 2009

The objective of this study was to examine the acid-base status in blood obtained at cordocentesis in growth-retarded fetuses with absent end-diastolic velocity in the umbilical artery and divided according to the presence or absence of pulsations in the umbilical vein. Twenty-six growth-retarded fetuses free from structural and chromosomal abnormalities were considered for this study. All the fetuses had absent end-diastolic velocity in the umbilical artery associated in 11 cases (42.3%) with pulsations in the umbilical vein. Gas analysis of fetal blood obtained by cordocentesis was performed immediately after the Doppler recordings. Hypoxemia, acidemia and hypercapnia were defined respectively as the presence of pH or pO2 values 2 standard deviations below the normal mean for gestation and of pCO2 values 2 standard deviations above the normal mean for gestation. Fetuses with umbilical vein pulsations had lower values of pH (p < 0.001) and pO2 (p < 0.05) and higher values of pCO2 (p < 0.001) when compared to those without pulsations. All fetuses with pulsations were hypoxemic and hypercapnic and the incidence of acidemia was 90.9%. Fetuses with continuous blood flow in the umbilical vein, although frequently hypoxemic (80%), have pC02 and pH values within the normal range in 40 and 52.3% of the cases, respectively. In conclusion, in fetuses with absent end-diastolic velocity in the umbilical artery the presence of umbilical vein pulsations identifies a subgroup of fetuses with a more severe compromise of acid-base status. This may be useful in the selection of the timing of delivery of such fetuses.
Methylxanthines Increase Renal Calcium Excretion in Preterm Infants
Authors: Zanardo Vincenzo , Dani Carlo , Trevisanuto Daniele , Meneghetti Stefano , Guglielmi Alberto , Zacchello Graziella , Cantarutti Felice
Published: October 2009

To determine the effect of a short course of methylxanthines on renal function and on urinary calcium excretion, 20 premature neonates affected by apnea or moderate respiratory distress syndrome were randomly assigned to either a theophylline treatment or to a caffeine treatment group. The protocol included a 24-hour pretreatment study period (I) and a subsequent 24-hour period (II) following 5 days of theophylline (loading dose 5 mg/kg i.v., maintenance dose 2.5 mg/kg/l2 h) or caffeine (loading dose 10 mg/kg i.v., maintenance dose 2.5 mg/kg/l2 h) administration. Pre- and postxanthine treatment serum sodium, potassium, calcium and phosphorus remained stable, while serum creatinine decreased significantly (p < 0.05). Furthermore, from period I to period II, sodium urine excretion, fractional Na excretion and creatinine clearance remained statistically comparable in both study groups, along with a significant increase (p < 0.05) in calciuria, urinary Ca/creatinine and urinary Ca/Na. Predose caffeine and theophylline serum levels, assessed on the 5th day of treatment, were 12.8 ± 1.8 and 7.9 ± 1.7 μg/ml, respectively. Compared to control healthy untreated prematures, the studied premature infants showed a statistically significant increase in urine calcium excretion (10- to 15-fold), which was more evident in the theophylline group. Our data suggest further investigation to determine the long-term renal effects of methylxanthines in premature neonates, to improve assessment of the risk of nephrocalcinosis and osteopenia, in particular in association with various diuretic therapies.
Renal Masses in the Neonate
Authors: Pinto Eduarda , Guignard Jean-Pierre
Published: October 2009

Abdominal masses are frequent in newborn infants, two thirds being renal in origin. After thorough palpation of the abdomen, cystic masses must be differentiated from solid masses by ultrasound examination. The common benign cystic masses include hydronephrosis, multicystic dysplasia, polycystic disease, and adrenal hemorrhage. Solid masses include renal vein thrombosis, a renal ectopic kidney, or horseshoe kidneys. Occasionally, a renal mass may be malignant and correspond to congenital mesoblastic nephroma, Wilms’ tumor, or fetal hamartoma. Whatever the nature of the renal mass, early intervention may save the kidney or the patient.
Furosemide Pharmacokinetics following Intratracheal Instillation in the Guinea Pig
Authors: Smith Sue Ann , Pillers De-Ann M. , Gilhooly Joseph T. , Wall Michael A. , Olsen George D.
Published: October 2009

Inhaled furosemide has been shown to attenuate bronchospasm in asthmatics and to increase lung compliance in infants with bronchopulmonary dysplasia (BPD). The reports involving BPD used a dose of 1 mg/kg and some have failed to show an effect with that dose. We determined the pharmacokinetics of furosemide administered directly to the airway in 7 young adult male guinea pigs who received intravenous and intratracheal doses of furosemide. Each animal received a 3 mg/kg i.v. bolus, 1, 3 and 6 mg/kg i.t. in 2 ml/kg normal saline and 3 mg/kg i.t. in 2 ml/kg bovine extract surfactant. Blood was sampled multiple times after each dose. The mean fraction of the intratracheal dose absorbed was 0.50–0.60 for all doses. Surfactant delayed the absorption of furosemide but did not alter the fraction absorbed.
Carnitine Depletion in Rat Pups of Lactating Mothers Given Sodium Pivalate
Authors: Davis Alan T.
Published: October 2009

The purpose of this study was to determine the effect of pivalate administration in the pregnant and lactating rat upon tissue carnitine concentrations in 1- and 5-day-old rat pups, as well as in the lactating rats. At 17 days of gestation, 5 rats began receiving 20 mmol/l sodium pivalate in their drinking water, while an additional 5 rats (control) received equimolar NaHCO3. There were no significant differences in litter size, or in pup weights at day 1 (p > 0.05). However, the pups from the pivalate group did weigh significantly less at 5 days of age relative to the control group. Neonatal rats in the pivalate group had significantly depressed levels of total carnitine in plasma, heart and liver, relative to the control group, at both 1 and 5 days of age. Similar depressions were noted for the lactating rats from the pivalate group. This study demonstrates the utility of pivalate administration in depressing carnitine concentrations in newborn rats.
Glucocorticoid-Dependent Induction of the mRNA Coding for Argininosuccinate Lyase in Cultured Fetal Rat Hepatocytes
Authors: Renouf Sylvie , Fairand Alain , Husson Annie
Published: October 2009

Dexamethasone increased both argininosuccinate lyase (ASL) activity and specific mRNA level in cultured fetal hepatocytes. Addition of various inhibitors of RNA synthesis showed that the increase in ASL mRNA may be related to an enhancement of ASL gene transcription, but not to a specific messenger stabilization. An apparent half-life of about 12 h for ASL mRNA was found in both untreated and dexamethasone-treated hepatocytes. About 30 h were necessary to observe the maximal effect of dexamethasone, and, in addition, both puromycin and cycloheximide (two inhibitors of protein synthesis) blocked the inducing effect of the steroid. These results suggested the involvement of intermediary protein(s) in the mechanism of induction of ASL mRNA by glucocorticoids.