bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Prostaglandin E2 on Adenylate Cyclase Activity in Isolated Glomeruli and Tubules during Postnatal Maturation of Rat Renal Cortex
Authors: Judes Clément , Helwig Jean-Jacques , Bollack Claude
Published: September 2009

To examine the effect of prostaglandins on adenylate cyclase during the postnatal maturation of kidney, the prostaglandin E2 (PGE2) responsiveness of adenylate cyclase in the absence and presence of exogenous GTP was investigated in glomeruli and tubules isolated from renal cortex of 14-, 21- and 30-day-old rats. In the absence of GTP, the adenylate cyclase response to PGE2 in glomeruli of 14-day-old rats was about fourfold higher than that in 21- and 30-day-old rats. In the tubules there was an about 30–35% decrease in the enzyme response to the prostaglandin between 14 and 21 days as well as between 21 and 30 days. When GTP was present, the PGE2 responsiveness of adenylate cyclase was of the same order of magnitude in glomeruli at 14 and 21 days and lower at 30 days. Under the same conditions, no significant changes were observed in the cortical tubules throughout the period studied. Thus association of PGE2 plus GTP suggests that during the postnatal maturation of rat kidney, the response of adenylate cyclase to PGE2 remains unchanged in cortical tubules and slightly decreases in glomeruli.
Serum Lipoproteins in Venous Blood Serum from Birth to the End of the First Week: Feeding Influences
Authors: Tenenbaum Denis , Gambert Philippe , Meunier Sylvie , D’Athis Philippe , Nivelon Jean Louis , Lallemand Christian
Published: September 2009

Serum lipoproteins were explored on the first day of life (D1) and on the sixth day (D6) in blood drawn by peripheral venipuncture from 43 normal term newborns, 22 breast-fed and 21 formula-fed, and were compared to those of a control group of 28 young adults. With the exception of apolipoprotein E (Apo E), values of lipoprotein components obtained at D1 were similar, although generally slightly lower than those previously reported for cord blood serum. Total Apo E concentration at D1 (71 ± 25 mg/l) was much higher than that obtained for the adult group (30 ± 7 mg/l). Apo E distribution within the lipoprotein spectrum confirmed the presence of an already known Apo E-rich high density lipoprotein subfraction, which was responsible for the high total Apo E level at birth. The rise of lipoproteins of low density from D1 to D6, as evidenced by the increase of very low density lipoprotein + low density lipoprotein cholesterol and low density lipoprotein apolipoprotein B concentrations, was shown to be diet dependent. It was significantly less important in newborns fed a standard formula moderately enriched in unsaturated fatty acids than in breast-fed newborns.
Physiologic Jaundice in the Nigerian Neonate
Authors: Okolo Angela A. , Omene Jackson A. , Scott-Emuakpor Ajovi B.
Published: September 2009

In the course of a systematic study of physiologic hyperbilirubinaemia, 200 Nigerian newborn infants were evaluated daily over a 12-day period. The pre-term and post-term neonates exhibited a distinct biphasic pattern of hyperbilirubinaemia. Mean peak bilirubin levels of 8.20 mg/dl for the pre-term, 7.15 mg/dl for the post-term and 8.34 for the term were attained on the fourth, third and fifth days, respectively. Term small for gestational age neonates experienced mean peak bilirubin levels of 7.02 mg/dl at the age of 4 days and maintained a sustained elevation for as long as the last day of the study. Higher values of physiologic hyperbilirubinaemia are observed in this study than has been reported for American neonates.
Differences between Pregnant and Nulliparous Rats in Basal and Stress Levels of Metallothionein
Authors: Hidalgo Juan , Giralt Mercé , Garvey Justine S. , Armario Antonio
Published: September 2009

The present experiment was designed to examine the influence of pregnancy on basal and stress levels of serum and liver metallothionein (MT). Eighteen-day pregnant rats showed higher serum MT levels and lower liver MT levels than nulliparous rats, suggesting that a great MT mobilization from the liver into the serum was present in the former rats. Serum MT levels were not changed by either restraint or starvation. It is unlikely that the lower liver MT levels showed by pregnant rats were due to competition by progesterone for glucocorticoid receptors, as previously suggested, since the corticosterone/progesterone ratio was unchanged in pregnant rats. Liver MT response to food and water deprivation with or without restraint was somewhat different in nulliparous and pregnant rats. Thus, food and water deprivation for 24 h caused higher liver MT induction in pregnant than in nulliparous rats. When food and water deprivation was accompanied by restraint stress a further increase in liver MT was observed in nulliparous but not in pregnant rats. This suggests that food and water deprivation may be a more severe stress in pregnant rats because of the additional demands of the growing fetuses. Fetal liver MT was increased by restraint stress but not by food and water deprivation. The role of Zn influx into the liver is discussed.
Neutrophil-Mediated Killing, Opsonization, and Serum-Mediated Killing of Escherichia coli K1 by Neonatal Rats
Authors: Lassiter Herbert A. , Christensen Robert D. , Parker Charles , Rothstein Gerald
Published: September 2009

Neonates are particularly susceptible to infection with Escherichia coli K1. To investigate the mechanisms which lead to this susceptibility, we examined: (a) the bactericidal activity of neutrophils; (b) opsonization, and (c) the bactericidal activity of serum in developing rats. Neutrophils from adult rats killed E. coli K1 more efficiently than did neutrophils from young animals. Opsonization of E. coli K1 by serum of prematurely delivered rats was poor. Serum from prematurely delivered and term rats promoted growth of E. coli K1, while serum from adult rats killed > 95% of the organisms within 90 min. However, the mixture of heat-inactivated serum from adult rats plus serum from prematurely delivered rats killed E. coli K1.
Major Malformations of the Urinary Tract
Authors: Gillerot Y. , Koulischer L.
Published: September 2009

This paper outlines the problem of major malformations of the urinary tract, their frequency and their etiology. It is based on data analysis of 900 neonatal autopsies performed in our center from 1978 to 1987. These major malformations are often lethal and they can essentially be separated into disorders of the kidney and malformations of the lower urinary tract. Single-gene disorders are often seen in the former whereas the second group is more likely to be multifactorially controlled. We do insist on the importance of a strict collaboration between pathologists and geneticists.
Hormonal Regulation of Renal Function during Development
Authors: Robillard Jean E. , Nakamura Kenneth T.
Published: September 2009

The present review summarizes current and new knowledge concerning the major hormonal systems that directly or indirectly affect renal function during development. The role of the renin-angiotensin-aldosterone system in regulating renal function during fetal and postnatal life is reviewed. A summary of the role of this system during fetal and postnatal stresses is also provided. The physiological role of the renal kallikrein-kinin system in the control of renal blood flow, renin release and sodium excretion during development is examined. Possible influences of the prostaglandin system on regulation of renal function and renin secretion during fetal and postnatal maturation are explored. The effect of vasopressin on the ability of the fetal and postnatal kidney to concentrate urine and regulate body fluid homeostasis is reviewed in detail. The physiologic action of vasotocin on renal sodium and water homeostasis is described. New information regarding the role of the sympathetic system in the regulation of renal hemodynamics and in the control of renal function during development is presented. Finally, recent studies demonstrating the effect of atrial natriuretic factor and corticosteroids on the developing kidney are discussed.
Renal Function and Fluid Therapy in High Risk Infants
Authors: Oh William
Published: September 2009

In recent years, the survival rate of high risk infants has markedly increased. The role of such medical management as fluid, electrolyte and nutritional therapy have assumed a greater importance in assuring optimal quality of the survivors. The very low birth weight infants, particularly those with respiratory distress syndrome and perinatal asphyxia, are at highest risk. The inefficient renal function, unique characteristic of body fluid composition and/or presence of severe clinical illness often make the management of fluid and electrolytes in this group of infants difficult. The numerous factors that influence insensible water loss make calculation of fluid management in the high risk infant even more challenging. Systematic collection of data such as daily body weight, intake, output, urine specific gravity and serum electrolyte is essential to appropriately maintain fluid and electrolytes balance in these infants. Respiratory distress syndrome is a common problem in premature infants and the fluid and electrolyte management in these infants will require similar attention to details as described for the fluid and electrolytes of very low birth infants. Perinatal asphyxia often results in oliguria or anuria because of possible development of inappropriate ADH secretion or acute tubular necrosis. It is essential that fluid restriction be done on the first day or two of life to avoid fluid overload.
Adverse Effects of Drugs on the Immature Kidney
Authors: Guignard J.-P. , Gouyon J.-B.
Published: September 2009

The immature kidney may be adversely affected by a variety of vasoactive or diuretic drugs, either administered to the mother during pregnancy, or to the neonate. Inhibitors of the angiotensin-converting enzyme administered to the hypertensive pregnant woman can severely and sometimes definitely impair renal function in the fetus, leading to postnatal anuria. Pathogenesis involves interference with the renin-angiotensin system and the prostaglandins. Beta-adrenergic agents administered during labor depress glomerular filtration rate transiently. Tolazoline, an alpha-adrenergic blocking agent useful in the treatment of persistent pulmonary hypertension of the neonate induces intense renal vasoconstriction with consequent hypoperfusion. Indomethacin, a prostaglandin synthetase inhibitor used for the pharmacological closure of a patent ductus arteriosus, also increases renal vascular resistance, and decreases urine output. Furosemide, the drug most often used in oliguric neonates, may also adversely affect the newborn infant. Its use has been associated with an increase in the incidence of patent ductus arteriosus, hypercalciuria, nephrocalcinosis and secondary hyperparathyroidism. These observations demonstrate that the proper use of drugs requires that the therapeutic endpoint be clearly defined and the predictable side effects be anticipated.
Aminoglycoside Nephrotoxicity and Urinary Excretion of N-Acetyl-Beta-D-Glucosaminidase
Authors: Langhendries J.P. , Battisti O. , Bertrand J.M.
Published: September 2009

The purpose of this paper is to discuss briefly the mechanism of aminoglycosides nephrotoxicity. This kind of antibiotic seems to act preferentially on the phospholipid metabolism of the proximal tubular cell. A lysosomal enzyme, N-acetyl-beta-D-glucosaminidase, could be of interest in assessing this renal interference.
Influence of Radiant Heat Stress on Respiratory Water Loss in New-Born Lambs
Authors: Riesenfeld T. , Hammarlund K. , Jonzon A. , Sedin G.
Published: September 2009

Respiratory water loss, oxygen consumption and carbon dioxide production were measured during rest and during moderate radiant heat stress in 9 healthy unanaesthetized lambs, age 4–15 days. The method used is based on an open flow-through system with a mass spectrometer for gas analyses. Respiratory water loss was 12.7 mg/kg min when the lamb was at rest and increased to 24.7 mg/kg min during heat stress. Oxygen consumption was 13.9 ml/kg min at rest and remained unchanged during heat stress. The mean rate of breathing increased from 63 to 125 breaths/min.
Maternal-Fetal Relationship in Ammonia Metabolism during Late Gestation in the Rat
Authors: Garcia Victoria , Martín-Barrientos Josefa , Medina José M.
Published: September 2009

The concentrations of the major metabolites for nitrogen excretion and/or transport in maternal and fetal blood and amniotic fluid during the last 2 days of gestation were investigated. Alanine, glutamine, ammonia and allantoin accumulated in amniotic fluid during late gestation. Urea concentrations increased in amniotic fluid though only during the last day of gestation, suggesting that urea is taken up by the mother through the amniotic membranes. Glutamate did not accumulate in amniotic fluid during late gestation although high concentrations of it were found in fetal blood in the same circumstances, suggesting the occurrence of a mechanism for preventing fetal glutamate disposal.
Characteristics of Postnatally Induced Alterations in Thyroxine 5′- and 5-Monodeiodinating Activities in Several Pig Tissues
Authors: Ślebodziński A.B. , Brzezińska-Ślebodzińska E.
Published: September 2009

Changes in the in vitro hepatic, kidney, skeletal muscle, heart and brain 5′- and 5-monodeiodinase activities were studied in piglets aged 4–12 h and 3, 7, 14, 21, and 42 days. As compared to the adult pig, the hepatic conversion of thyroxine (T4) to 3,5,3′-triiodothyronine (T3) and 3,3′5′-triiodothyronine (rT3) was on average 3–5 times higher in the liver, and equal or lower in the kidney. At birth, the liver generated about 66% of T3 and 75% of rT3, the other tissues the rest. Increasing contribution of skeletal muscles in the postnatal process of triiodothyronines generation was found. The apparent Km and Vmax values suggested higher capacity of T4 converting systems in newborns than in adults, and an increase in the enzyme affinities. Shortly after birth serum rT3 but not T3 corresponded to the level of hepatic and kidney T4 conversion.
Effect of Chronic Modification of Diet Fat and Cholesterol during Gestation on Plasma Hormones and Hepatic Enzyme Activities in Rat Fetus
Authors: Innis S.M. , Haave N.C.
Published: September 2009

Diet-induced elevation of cholesterol and corticosterone in pregnant rats had no effect on fetal plasma cholesterol or corticosterone, 3-hydroxy-3-methylglutaryl coenzyme A or hepatic reductase activities. The data suggest that increasing the maternal cholesterol pool has no effect on cholesterol transfer to, or metabolism in, the developing offspring, and that the late gestation fetus can maintain corticosterone levels appropriate to gestational age despite diet-induced elevations in the maternal plasma.
Impairment of Superoxide Release by Alveolar Macrophage in Rats Exposed to Oxygen and Vitamin E
Authors: Nakamura Hajime , Takada Satoshi , Sano Kimihiko , Komura Miyoji , Matsuo Tamotsu , Ohara Hidefumi
Published: September 2009

We examined the digitonin-stimulated release of superoxide by alveolar macrophages (AMs) from young rats exposed to > 95% oxygen for 24–168 h. AMS were obtained by lung lavages, and the release of superoxide stimulated by digitonin was measured by using cytochrome C reduction. The total cell count of lung lavages decreased at 24 and 168 h of oxygen exposure (p < 0.05 for both). The contamination of polymorphonuclear cells (PMNs) was less than 1% up to 120 h of oxygen exposure, and at 168 h PMNs increased to 5% of total cells in lung lavages. The viability of AMs was greater than 95% up to 72 h and then decreased to 90% at 120 h of oxygen exposure and 87% at 168 h. Digitonin-stimulated superoxide release by AMs recovered from lung lavages in rats exposed to hyperoxia showed a slight increase during the first 48 h. However, oxygen exposure for 72 h or more caused a significant decrease of the stimulated superoxide release of AMs compared to AMs from control rats. This decline in stimulated superoxide release of AMs resulting from hyperoxia was not prevented by vitamin E treatment.
Influence of Hydrocortisone on the Development of Pancreas in Suckling Rats
Authors: Puccio Francois , Chariot Jacques , Lehy Thérèse
Published: September 2009

The effect of hydrocortisone on the growth and differentiation of the pancreas was examined in suckling rats. Three doses of hydrocortisone (40, 20, 5 mg/kg/day) were administered during the second week of life. Biochemical and ultrastructural morphometric studies were performed on the pancreas at the end of the treatment. Whatever the dose used, hydrocortisone induced pancreatic hypertrophy and significantly increased enzymatic activities by 70–200% for lipase and colipase, 140–340% for trypsinogen and chymotrypsinogen and 600–1,200% for amylase. With the 20-mg/kg/day dose, ultrastructural morphometric data indicated that the increase in pancreatic weight was associated with cellular exocrine hypotrophy (diminution of cell size, and of the number of zymogen granules). They also suggest that hydrocortisone, at that dose, might enhance the excretion of secretory products. By contrast, the 5-mg/kg/day dose of hydrocortisone did not modify the acinar cell size, but significantly increased the number of granules per cell. The increase in pancreatic weight and the fact that either cellular hypotrophy or no change in acinar cell size was observed, strongly suggest that hyperplasia occurred with both doses. These results confirm that hydrocortisone is an important modulator of pancreatic development in the rat, inducing stimulation of pancreatic activities, associated with modifications in cell structure and components which vary according to the dose.
Vasoactive Compound Effects on Autoregulating versus Nonautoregulating Intestinal and Renal Circulations in Young Swine
Authors: Buckley N.M. , Diamant S. , Frasier I.D. , Owusu K.
Published: September 2009

Vascular resistance changes to single intra-arterial injections of norepinephrine, histamine and adenosine were examined in 12 kidney and 10 jejunum preparations perfused in situ in fasting swine anesthetized with pentobarbital. Threshold doses were higher and other response magnitudes were smaller in the nonautoregulating renal circulation of 1-week-olds and jejunal circulation of 2-week-olds than in âutoregulating circulations of 1-month-olds. These results suggest a correlation between maturation of autoregulatory capability and of vasodilator histamine and adenosine receptors.
Respiratory Failure Caused by Intratracheal Saline: Additive Effect of Xanthine Oxidase
Authors: Saugstad Ola Didrik , Hallman Mikko , Becher Günther , Oddoy Arno , Lium Björn , Lachmann Burkhard
Published: September 2009

Administration of physiological saline or drugs together with saline into the airways is becoming common clinical practice. However, there are few studies on possible side effects. We have studied the effects of saline, saline plus xanthine oxidase, and saline plus xanthine oxidase plus superoxidase dismutase on lung-thorax compliance and on arterial blood gases in anesthetized, paralyzed guinea pigs, ventilated for 2.5 h. Saline bolus (2–3 ml isotonic saline/kg body weight) into the airways reduced the compliance within 20 min to a mean of 39% of the pretreatment levels, and necessitated an increase in the respirator pressure. Saline plus xanthine oxidase decreased the compliance to 16 % of the pretreatment levels. The xanthine oxidase-induced (but not saline-induced) decrease in lung compliance was relieved by superoxide dismutase. According to the present results xanthine oxidase induces a lung injury possibly by production of free oxygen radicals. Superoxide dismutase can be valuable in prevention of free oxygen radical-mediated lung damage. Saline alone can be harmful when applied to the airways. This should be considered in clinical trials and in clinical practice.
Percutaneous Respiration in the New-Born Infant
Authors: Cartlidge P.H.T. , Rutter N.
Published: September 2009

The effect of increasing ambient oxygen concentration on percutaneous oxygen absorption was studied by measuring pulmonary oxygen uptake before and after exposure of the skin to 90% oxygen; assuming the metabolic demands of the infant remain unchanged, the pulmonary oxygen uptake should fall as percutaneous absorption increases. During the first few days of life, in infants between 28 and 30 weeks gestation, there was a significant reduction in the mean pulmonary oxygen uptake of 0.27 ml/kg/min (6.2%) when the trunk and limbs were surrounded by 90% oxygen. The calculated fall in pulmonary uptake if the whole body was surrounded by 90% oxygen would be 8–10%. In contrast, the changes seen in more mature infants (32–39 weeks gestation) and older infants (28–29 weeks gestation and 7–17 days old) were small and not significant. Percutaneous oxygen delivery may usefully contribute to the total oxygen requirements of very preterm infants during the early neonatal period.
Urocytogram, an Index of Maturity in Premature Infants
Authors: Robine N. , Relier J.P. , LeBars S.
Published: September 2009

Cellular material found in urinary sediment stems essentially from exfoliated cells of the vesical triangle whose morphology is under the influence of the sex hormones. The study of cellular modifications forms the basis of a cytological procedure – the urocytogram. The urocytograms of 103 newborns, both premature and full term, made in the intensive care unit of the Department of Neonatal Medicine, Port-Royal Hospital, Paris, showed that marked changes in hormonal impregnation occur as a function of gestational age and permitted the establishment of a maturation index for the epithelium of the vesical triangle. In boys, the percentage of basal cells varied from 17.30 at 28 weeks’ gestational age to 31.64 at term; while in girls the variations were less marked: 0.20 at 28 weeks to 1.37 at term. The oestrogen index (OI) was higher in a girl at 28 weeks (OI = 45.20) than in a girl born at term (OI = 13.50). The lower the gestational age the higher the pyknotic index (PI = 52.80 at 28 weeks), and the latter decreased as gestational age rose (PI = 23.12 at term). In boys, the oestrogen and pyknotic indices showed less variation (18.50 at 28 weeks and 15.29 at term). It thus appears that the urocytogram, a totally nontraumatic examination of urine samples obtained by simple miction, has its place among the tests of fetal maturity.
Lung Glycogen Metabolism in Suckling Rats: A Comparative Study
Authors: Maritz G.S.
Published: September 2009

Glycogen metabolism was studied in lungs of suckling rats and the data was compared with that of the adult. From the data it appeared that the control of glycogen metabolism of lung tissue of suckling rats differs from that of adult lung. After a 24-hour fasting period, the lung glycogen content of 1- to 2-week-old rats was decreased (p < 0.05). This was accompanied by an increased (10%) phosphorylase activity (p < 0.001). In contrast to this, the lung glycogen content of adult lung increased by about 26% (p < 0.05) while at the same time the hexokinase activity increased by about 39% and the phosphorylase activity decreased by about 65%. Also, the 1- to 2-week-old lung utilized glycogen more readily (9.00 ± 0.04 μmol/g/h) than adult lung (3.70 ± 0.15 μmol/g/h). This means that lung tissue of suckling rats is more dependent on glycogen than adult lung which is probably the reason for the difference in control.
Vascular Placental Insufficiency in the Rabbit
Authors: Harel S. , Sömjen D. , Earon Y. , Tomer A. , Kaye A.M. , Kariv N. , Binderman I.
Published: September 2009

Vascular placental insufficiency is considered a common pathogenic factor in human intrauterine growth retardation. To mimic this condition, the rabbit, a ‘perinatal brain developer’ was utilized as an experimental model. Ischemic conditions were achieved by total ligation of approximately 30% of the uteroplacental vessels of half of the fetuses in each pregnant rabbit in the last third of gestation. The change in activity of the brain type isozyme of creatine kinase (CKBB), involved in energy regeneration and regulation, was assessed as a response marker to tissue ischemia in rabbit tissues: cerebellum, cerebrum, kidney, liver and placenta. A significant transient increase in CK-specific activity was found in the kidney and the cerebellum but not in the other organs tested, at 24 and 48 h after ligation. This increase was not seen with adenylate kinase, another enzyme involved in energy regeneration and regulation. It is proposed that an increase in CK-specific activity could serve as a metabolic marker of vascular insufficiency in rapidly developing tissues, representing part of a compensatory mechanism to overcome an energetic gap induced by ischemia.
Alanine Turnover Rate and Its Hepatic Metabolism Are Increased in Midpregnant Rat
Authors: Pastor-Anglada Marçal , Champigny Odette , Ferré Pascal , Remesar Xavier , Girard Jean
Published: September 2009

At mid pregnancy (12th day) fed rats exhibit a drop of blood alanine level when the weight of the fetoplacental unit is still negligible. A primed infusion A-V method was used to measure alanine kinetics in fed midpregnant rats and virgin controls, using L-[2,3–3H]alanine as a tracer. Alanine turnover and metabolic clearance rates were higher on day 12 than in virgin controls. The increase in alanine turnover rate was accounted for by an increase in alanine degradation. Since the liver is the main site of alanine degradation, alanine uptake was studied in isolated hepatocytes. Hepatocytes isolated from midpregnant rats utilized 50% more alanine than those from virgin controls. This increase was mainly due to metabolism rather than incorporation into proteins. In conclusion, the alanine turnover rate and its hepatic metabolism are increased in fed midpregnant rats, resulting in the decrease in blood alanine.
Impact of Protein-Calorie Malnutrition on the Developing Intestine
Authors: Butzner Decker , Gall Grant
Published: September 2009

We assessed the impact of protein-calorie malnutrition on the developing rabbit intestine. Litters expanded 7 days postpartum (13–16 animals) were compared to control litters (6–8 animals). Chronic nutrient deprivation in early life markedly reduced small intestinal mass, as evidenced by depressed weight, crypt-villus length, protein content and DNA content. In kinetic studies, we observed impaired mucosal growth in undernourished rabbits, as demonstrated by depressed enterocyte proliferation and epithelial migration. Intestinal maturation also appeared to be modified, as suggested by altered mucosal enzyme activities and enhanced permeability which we evaluated by measuring unidirectional Na+ transport in short-circuited Ussing chambers. These findings may contribute to the increased severity of diarrheal illness observed in clinical malnutrition in infancy.
Regulation of Growth Hormone Release in Fetal Calves
Authors: Coxam Véronique , Davicco Marie-Jeanne , Dardillat Claude , Robelin Jacques , Lefaivre Jacques , Opmeer Fred , Barlet Jean-Pierre
Published: September 2009

Plasma GH and IGF1 concentrations were measured during the last 2 months of gestation in 9 chronically catheterized fetal calves under basal conditions or following growth-hormone-releasing factor (GRF), thyrotropin-releasing hormone (TRH) or SRIF intravenous cotyledonnary injections. Plasma GH concentrations were higher in fetuses (1.40 ± 0.10 nmol/l) than in dams (0.14 ± 0.01 nmol/l). Plasma GH secretory profile was pulsatile. The number of secretory pulses, as well as their magnitude and mean baseline values decreased from 220 to 270 days of gestation. Synthetic 1–29 GRF or TRH increased fetal plasma GH concentration at 250 and 270 days of gestation but was devoid of any significant effect at 220 days. SRIF injection decreased plasma GH concentration in 270-day-old fetuses. Plasma IGF1 concentrations were lower in fetuses than in dams. No treatment had a significant effect on fetal and maternal IGF1 levels.
Concentration of Hypoxanthine in both Cerebrospinal Fluid and Brain Tissue Increases under Intensive Hypoxia Only
Authors: Lun Andreas , Gross Johann , Siggel Holger , Pohle Renate
Published: September 2009

The relationships between the concentrations of glycogen, glucose, lactate, adenosine triphosphate (ATP) and hypoxanthine in the brain tissue, and the hypoxanthine and lactate concentration in cerebrospinal fluid and blood were examined after exposure of rats to hypoxia. The animals (1 and 10 days old) were exposed to hypobaric hypoxia for 1–12 h, pO2 11.3 kPa (mild), pO2 8.6 kPa (moderate), pO2 6.4 (strong) and pO2 4.7 kPa (severe) in inspired air. The concentration of hypoxanthine in both cerebrospinal fluid and brain tissue increases in severe hypoxia. This severe hypoxia was related to a decrease of ATP level in brain tissue. This study showed that the level of hypoxanthine in blood did not closely correlate to the level of hypoxanthine in brain tissue and cerebrospinal fluid. Extremely high hypoxanthine values in the blood might indicate a decrease in ATP content in brain tissue.
Maternal Treatments with Corticosteroids and/or T3 Change Lung Volumes and Rupture Pressures in Preterm Rabbits
Authors: ElKady Tarek , Jobe Alan
Published: September 2009

Pregnant does were treated with betamethasone, T3, the combination of betamethasone and T3 or vehicle control on days 24 and 25 of gestation. At 26 days gestional age, pressure-volume curves and lung rupture pressures and volumes were measured in the various groups of rabbits randomized to receive saline or surfactant by tracheal injection. Alveolar wash and lung tissue quantities of saturated phosphatidylcholine were comparable across the hormone-treated and control groups. Corticosteroids increased maximal lung volumes more than did T3. Corticosteroids augmented the lung volumes of surfactant-treated lungs more than did T3, and no additive effects on lungs treated with both hormones and surfactant were noted. Both corticosteroids and surfactant decreased lung rupture pressures from 51.7 ± 4.1 to about 44 cm H2O. T3 decreased lung rupture pressure to 48.9 ± 3.9 cm H2O and the combination of T3 and corticosteroids resulted in rupture pressures comparable to T3 alone. There were no additive effects of the combined use of T3 and corticosteroids and T3 antagonized the decreased lung rupture pressures caused by corticosteroids. While T3 did not alter the increase in lung volumes noted with corticosteroids, lung structure as assessed by lung rupture was differentially affected by the two hormones.
Effects of Antenatal Hydrocortisone on Tidal Volumes in Spontaneously Breathing Preterm Newborn Rabbits
Authors: Hedner T. , Bergman B. , Freyschuss U. , Grossmann G. , Robertson B.
Published: September 2009

Rabbit fetuses were injected on day 26 of gestation with hydrocortisone (2 mg) and delivered by hysterotomy 2 days later. The animals were tracheotomized at birth, and tidal volumes and esophageal pressures were recorded during spontaneous ventilation at standardized intervals from the first breath to the age of 2 h. In a subgroup of animals, the catecholamine content was measured in the adrenal glands. In comparison with littermate controls, tidal volumes were enlarged in hydrocortisone-treated neonates at the first breath and 60 min after birth; however, this effect was associated with an increased incidence of intra-alveolar hemorrhage. Hydrocortisone-treated animals also had a significantly increased adrenal content of adrenaline. Our data confirm a modest beneficial effect of antenatal hydrocortisone treatment on the fetal lung and suggest that this might in part be mediated by adrenal catecholamines. Stimulation of β-adrenergic receptors could thus potentiate the effect induced by direct influence of glucocorticoids on fetal lung maturation.
Impact of Nutrition on Postnatal Development of Serine-Threonine Dehydratase and Branched-Chain Keto Acid Dehydrogenase in the Rat
Authors: Grogan C.K. , Janas L.M. , Hendrix M.K. , Layman D.K. , Picciano M.F.
Published: September 2009

The developmental patterns of two amino acid-catabolizing enzymes, serine-threonine dehydratase (STD) and branched-chain α-keto acid dehydrogenase (BCKAD), were investigated in growing rats. At 10, 15, 20, 30, and 60 days of age, STD and BCKAD activities were determined in pup tissues. Hepatic STD activity increased more than 3-fold between 10 and 20 days of age; after this peak, activity decreased by 30 days of age. Threonine dosing did not affect STD activity at any age. In the liver, kidney, brain and skeletal muscle, total BCKAD activity increased 2- to 4-fold between 10 and 30 days of age. Percentages of BCKAD active in all tissues decreased between 10 and 15 days of age, associated with a large increase in total activity. The percentages of BCKAD activity were unchanged between 20 and 30 days of age but increased from 30 to 60 days of age, associated with a decrease in total activity. Leucine dosing did not affect total BCKAD activity at any age. These results demonstrate that both STD and BCKAD develop late during the suckling period and total activities are unresponsive to excess dietary amino acids.
Interaction of Insulin with Small Intestinal Epithelial Cells from Developing Rats
Authors: Fernández-Moreno M.D. , Fernández-González M.A. , Díaz-Juárez J.L. , López-Luna M.P. , Prieto J.C.
Published: September 2009

The interaction of insulin with its specific receptors was studied in jejunoileal epithelial cells from 14-, 20-, and 60-day-old rats. Characteristics such as potency and specificity of the insulin receptor system did not vary during development. However, insulin binding decreased with age due to a diminished concentration of insulin receptors, whereas the circulating levels of the hormone followed an inverse evolution. These results support previous suggestions on the potential role of insulin on the mechanisms of differentiation and proliferation of small intestinal mucosa.
Neonatal and Adult Copper-64 Metabolism in the Pig and the Possible Relationship between the Ontogeny of Copper Metabolism and Wilson’s Disease
Authors: Bingle Colin D. , Srai Surjit K.S. , Whiteley Graham S.W. , Epstein Owen
Published: September 2009

The copper profiles of neonatal mammals differ from those of the adult; in man they are similar to those found in people with Wilson’s disease (WD). WD patients handle an intravenous bolus of radioactive copper in a characteristic manner which aids diagnosis. In view of the similarity between neonatal mammals and WD patients, we have studied the fate of an intravenous bolus of 64Cu injected into neonatal and adult pigs. In adult pigs, plasma 64Cu activity fell for 10 h and then slowly increased over the next 14 h as newly synthesised caeruloplasmin was secreted. In the neonate a secondary rise in 64Cu activity was not observed. Gel filtration of the soluble supernatant revealed significant differences in the association of 64Cu with hepatic copper proteins. In adults 64Cu associated predominantly with superoxide dismutase whilst in the neonate the 64Cu associated with metallothionein and a protein of high molecular weight. This study indicates that 64Cu export from the neonatal pig liver is in many ways similar to that found in WD. Additionally, there are similarities in the profile of hepatic 64Cu-binding proteins.
Corticosteroid Increases Gastrointestinal Luminal Proteolysis in Suckling Rats
Authors: Britton John R. , Koldovský Otakar
Published: September 2009

Although stress during the perinatal period may influence a number of enzymes in the gastrointestinal tract, the resulting effects on digestive processes are not completely understood. In suckling rats, corticosteroid administration increases levels of proteases in gastric mucosa and pancreas, but previous studies of unstimulated luminal fluid proteolytic activity suggest no effect. To re-evaluate this phenomenon, we injected suckling rats with cortisone acetate (5 mg/l00 g body weight) subcutaneously daily on days 9-11 followed by sacrifice on day 12; littermates served as controls. Luminal fluid from stomach and small intestine was analyzed for proteolytic activity by a sensitive assay in which incubation in vitro with 125I-bovine casein was followed by measurement of radioactivity soluble in trichloroacetic acid. Cortisone acetate produced significant increases in luminal proteolytic activity in all gastrointestinal segments with the most dramatic effect observed in the ileum; this segment showed a more than 10-fold enhancement of proteolysis with steroid treatment. Analysis of acid-precipitable reaction products by electrophoresis in polyacrylamide gels containing sodium dodecyl sulfate also revealed enhancement of casein degradation by luminal fluid in all segments from steroid-treated animals. We conclude that corticosteroid increases luminal proteolysis in the gastrointestinal tract of the suckling rat. This phenomenon may have implications for steroid-induced premature closure to macromolecular absorption and protein digestive capacity during the perinatal period.
Excessive Doses of Cerulein Stimulate Pancreatic Growth in Suckling Rats but Damage the Pancreas of Weaned Rats
Authors: Papp Miklós , Dobronyi István , Varga Gábor
Published: September 2009

The cerulein-stimulated pancreatic growth response was evaluated in 4- and 11-day-old female suckling CFY rats and compared with the pancreatic response of cerulein-treated 24-day-old weaned rats. Cerulein was given subcutaneously in saline in 1-, 10- and 100-μg/kg doses t.i.d. The increase in pancreatic DNA content was regarded as an index for hyperplasia, and the increase in pancreatic weight, protein content and enzyme activity related to milligrams of DNA as an index for hypertrophy. Three-day administration of 1-and 10-μg/kg doses of cerulein increased the pancreatic trypsin/DNA ratio, and doses of 100 μg/kg cerulein evoked pancreatic hypertrophy and hyperplasia in 4-day-old rats. Ten-day administration of 1- and 10-μg/kg doses induced pancreatic hypertrophy and hyperplasia, while the 100-μg/kg doses induced pancreatic hypertrophy in 11-day-old rats. In 24-day-old weaned rats, the 3-day administration of 1-μg/kg doses resulted in hypertrophy of the gland, while the 100-μg/kg doses of cerulein evoked pancreatic aplasia and atrophy. It is concluded that the growth-promoting effect of cerulein on the newborn rat pancreas is age- and dose-dependent.
Prenatal Protein-Energy Malnutrition Alters Various Biochemical Components of the Membranous Bones in Fetal Rats
Authors: Miwa Takashi , Shoji Hiromu , Solomonow Moshe , Nakamoto Tetsuo
Published: September 2009

The effects of prenatal protein-energy malnutrition on the biochemical parameters of the membranous bone were studied using fetal rats. Timed pregnant rats were fed a protein-deficient diet as an experimental group from day 13 of gestation, whereas control dams were fed a normal protein diet. By day 15, radioactive NaiSCO4 was injected. On day 22, all fetuses were delivered by cesarean section. The hexosamine content per milligram dry tissue, and the protein and hexosamine contents per guanidine-HCl extract were greater in the mandibles but less in the calvaria of the malnourished group than in those of the controls. Calcium content per gram dry tissue was lower in both bones of the malnourished group. 35S-sulfate uptake per milligram dry tissue or milligram proteoglycan was greater in the malnourished group than in the controls in both bones. The mandible in the malnourished group had less lower-weight molecular proteoglycan subunits in the dissociative condition. Protein-energy malnutrition affects the mandible and calvaria in different ways, although both bones originate from membranous bone. Insufficient degradation of proteoglycan could be the reason for the delay of mineralization in the malnourished bones.
Glucose Homeostasis in the Newborn
Authors: Flecknell P.A. , Wootton R. , Royston P. , John M.
Published: September 2009

The effect of oral feeding on the response to fasting and to an intravenous glucose infusion was investigated in neonatal piglets. Piglets, which had received no food at birth, reduced both their rates of glucose appearance and glucose utilisation (at 24 h: 43 ± 3.5 μmol/min in previously fed piglets and 28 ± 6 μmol/min in fasted piglets; at 48 h: 45 ± 3.5 μmol/min in previously fed piglets and 25 ± 5 μmol/min in fasted piglets). This reduction in glucose turnover was not associated with a fall in plasma glucose concentration, and all groups of piglets were normoglycaemic at the start of the study. An intravenous infusion of glucose (100 μmol/kg/min) resulted in suppression of hepatic glucose output and an increase in the glucose utilisation rate. Piglets, which had received no food at birth, had lower absolute rates of glucose utilisation throughout the period of infusion. The present study indicates that major changes in glucose turnover rates may occur prior to these being reflected in changes in blood glucose concentration. The results also indicate that oral feeding affects both steady-state glucose turnover and the response to an intravenous glucose infusion.
Social Inequalities in Perinatal Health
Authors: Masuy-Stroobant G.
Published: September 2009

In spite of an overall sharp decrease in the infant mortality level since the very beginning of the 20th century, one still observes a persistence of social inequalities, even in perinatal mortality, almost everywhere in Europe. International comparisons or trends are rather difficult to establish due to methodological and conceptual shortcomings. In the years 1979–1980, a comprehensive survey was conducted in one of the Belgian provinces, Hainaut, where information on the mothers’ behavior during pregnancy, including everyday life habits, was collected together with the usual identification factors. It appears that future research needs must be based on a new definition of the social gradients, shifting from the usual father’s socioeconomic reference to a more sociocultural integration gradient, taking also maternal and family characteristics into account in order to improve the understanding of the phenomenon.
History of Prenatal Care in Belgium
Authors: Bande-Knops J. , Renaer M. , VanTongelen E.
Published: September 2009

The history of the national mother and child care organization is reviewed up to 1980. The organisation originates in the efforts made during the First World War to provide food for mothers and children. Free prenatal visits have been organized since 1919. Among other activities, an extensive system of home visiting has been provided. The special program of prevention of preterm deliveries is an example of more recent actions focusing on high-risk groups.
Organization of Prenatal Care in Belgium
Authors: Humblet P.C. , Wollast E. , Vandenbussche P. , Leleux P. , Buekens P.
Published: September 2009

Prenatal care in Belgium is characterized by regional variations between the Flemish- and French-speaking communities. Generally, care in the former area is provided by a general practitioner or a gynecologist/obstetrician in private practice, and in the latter by a gynecologist/obstetrician on a private or public basis. The level of use of prenatal care observed is, on average, high, but variations do exist according to the socioeconomic and cultural characteristics of the families and the health care services which they frequent.
Organization of Obstetrical Care in Belgium
Authors: Derom R. , Pelfrene E. , Vlietinck R. , Thiery M.
Published: September 2009

Belgium, with its pluralistic health care system, has many small-sized maternity units staffed almost exclusively with obstetricians. The maternal and perinatal mortality and morbidity rates are still higher than in some of the neighboring countries. The new regulations with regard to the accreditation of maternity units might improve the figures. Other measures must be taken, however, to ensure that only low-risk patients are taken into small maternity units and that all high-risk cases and all those developing complications are cared for in large, well-equipped and well-staffed hospitals. Some form of peer review would also be beneficial.
Organization of Neonatal Care in Belgium
Authors: Van Reempts P. , Senterre J.
Published: September 2009

The objectives of this paper are (1) to describe the organization of neonatal care in Belgium; (2) to review evaluative studies aiming at assessing the availability, effectiveness and cost of care, and (3) to compare the situation in Belgium with that in other countries. In the future, basic neonatal care should be provided in each maternity unit. This means that many maternities need upgrading in staffing and equipment. For intensive care, there is only a need for 10–12 specialized centers in the country. A policy for rapid transfer of sick neonates to specialized centers should be implemented.
Arterial Hypertension in the Newborn Infant
Authors: Guignard J.-P. , Gouyon J.-B. , Adelman R.D.
Published: September 2009

Blood pressure is low at birth. It increases with age by about 1 mm Hg per day within the period of 3–8 days. It rises by about 1 mm Hg per week between 5 and 6 weeks of age. Neonatal hypertension carries a risk of cardiorespiratory failure and cerebral distress. Causes of neonatal hypertension are either secondary to congenital malformations or to acquired disease states. Congenital etiologies include: renal artery stenosis, renal artery hypoplasia, abdominal aortic atresia, coarctation of the aorta, kidney cystic disease, reflux nephropathies. Acquired causes include: thrombo-embolic renal artery complications secondary to umbilical artery catheterization or to thrombosis of the ductus arteriosus, closure of abdominal wall defects, adrenal hematoma with renal artery compression, seizures in preterm infants, central nervous system disorders, drug-induced hypertension, infants of drug-dependent mothers. The morbidity and the mortality of neonatal hypertension are elevated. Death may be caused by severe uncontrollable hypertension or by concomitant problems. Morbidity may be related to drug-resistant hypertension, or to the side-effects of hypotensive drugs.
Frequency of Cesarean Deliveries in Belgium
Authors: Thiery M. , Derom R. , Buekens P.
Published: September 2009

Belgium has not been spared the increase in the rates of cesarean section (CS) observed in other Western countries. In contrast with some of these countries, however, rate increases have been rather modest, both nationally and in most Belgian hospitals. Casuistic data suggest that the indications explaining the increase of CS rates in Belgium are by and large comparable to those pinpointed elsewhere. Ways to reduce rates of abdominal delivery are suggested.
Effect of Light on Diurnal Variation of Blood Amino Acids in Neonates
Authors: Mantagos S. , Moustogianni A. , Varvarigou A. , Frimas C.
Published: September 2009

Normal newborns show a diurnal variation of blood amino acid concentration, with lower values at 04.00 h and higher at 12.00 h. Three groups of infants, each consisting of 10 normal, full-term neonates, remained under different lighting conditions for 24 h and blood amino acids were determined at 04.00 and 12.00 h. Group A remained under continuous light, group B had the eyes covered, and group C was exposed to intermittent light, with the lights dimmed between 22.00 and 04.00 h. Group A showed a reversal of blood amino acid periodicity with a mean decrease of total amino acid concentration by 17.7% at 12.00 h (p < 0.025). In group B there was no statistically significant difference between 04.00 and 12.00 h values. Group C showed the usual amino acid periodicity with a mean increase of total amino acid concentration by 36.1 % at 12.00 h (p < 0.005). The differences observed between groups A and C were statistically highly significant (p < 0.0005). These data indicate that lighting conditions may affect the diurnal variation of blood amino acids and this should be considered for infants who remain under continuous light for prolonged periods in neonatal units.