bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative Toxicity of Caffeine and Aminophylline (Theophylline Ethylenediamine) in Young and Adult Rats
Authors: Warszawski Ditza , Gorodischer Rafael , Kaplanski Jacob
Published: September 2009

The toxicity of aminophylline and caffeine was studied in adult and 2-day-old rats following a single subcutaneous injection of the respective drug. Following the injection of high doses of either methylxanthine, adult rats developed convulsions, tremors, lethargy and licking of lips. In adult rats, the LD50 of caffeine and aminophylline was the same after 24 h and after 1 week of observation: caffeine 265 mg/kg, and aminophylline 202 mg/kg (theophylline base 172 mg/kg). In young rats, the LD50 was greater when the observation was carried out for 1 week than at 24 h after the injection; at 24 h: caffeine 220 mg/kg, and aminophylline 169 mg/kg (theophylline base 144 mg/kg); at 1 week: caffeine 155 mg/kg, and aminophylline 140 mg/kg (theophylline base 119 mg/kg). Young rats failed to gain weight at a normal rate after administration of either methylxanthine. The greater toxicity of both methylxanthines in newborn animals may be at least partly due to the extremely slow elimination of theophylline and caffeine in the neonate.
Possible Involvement of Growth Hormone in the Pathogenesis of Early Neonatal Hypocalcemia in Infants of Diabetic Mothers
Authors: Bergman Lars , Westerberg Barbro , Lindstedt Goran , Lundberg Per-Arne
Published: September 2009

The concentrations of plasma calcium and plasma growth hormone were determined up to 30 h of age in 10 infants of diabetic mothers (IDM) and 9 healthy infants. Plasma calcitonin was determined in all IDM and 5 control infants. The results are discussed in relation to the pathogenesis of early neonatal hypocalcemia.
Cardiovascular Responses to Autonomic Blockade in Brain-Injured Fetal Lambs
Authors: Lewis Alan B. , Nestor Larry , Dahms Beverly , Platzker Arnold C.G.
Published: September 2009

The cardiovascular responses to autonomic blockade were investigated in 15 late-gestation fetal lambs in utero. 4 animals had normal brains and 11 had hydranencephalic-like cerebral injury secondary to bilateral carotid artery obstruction (BCO). Following atropine administration, heart rate increased only 0.7 ± 0.7% in the BCO lambs compared to 25.7 ± 5.2% in the controls. α-Blockade with phentolamine resulted in a small decrease in systolic (2.2 ± 0.8%) and diastolic (1.8 ± 1.4%) blood pressure, and β-blockade with propranolol produced a small decrease in heart rate (2.5 ± 0.8%) as compared to control fetuses. Post mortem examination revealed extensive destruction of the cerebrum but normal hypothalamus and brain stem. These data suggest that supramedullary modification of autonomic cardiovascular control involves the cerebrum.
Gastric Response in Low Birth Weight Infants Fed Various Formulas
Authors: Pascale J.A. , Mims L.C. , Greenberg M.G. , Alexander J.B.
Published: September 2009

Feeding techniques, delayed gastric emptying, volume overload, or reverse peristalsis may lead to regurgitation and aspiration in the premature infant. Noting these complications, various aspects of gastric function were studied in relation to the type of formula fed. 27 low birth weight infants ( < 2,000 g) were each fed one of three randomly assigned commercial formulas, which varied in osmoiarity and MCT content. Gastric pH and emptying were monitored during the first 48 h of life. The fatty acid chain length of the triglyceride in the formula apparently did not influence either gastric pH or emptying. Infants fed formulas having a higher osmolar load (539 mosm/1) and containing protein hydrolysate showed greater gastric retention.
Intra-Uterine Malnutrition and Skeletal Retardation
Authors: Roord J.J. , Ramaekers L.H.J. , van Engelshoven J.M.A.
Published: September 2009

In the subgroup of small-for-dates, indicated as intra-uterine malnourished infants, we made an attempt to correlate the degree of starvation and the degree of skeletal retardation. In 31 wasted infants (including 4 post-mature children) and 20 not wasted infants, the ponderal index (100 × W/L3) was determined and deviation from ‘normal’ calculated. A highly significant correlation was found between the degree of malnutrition (deviation of the ponderal index from normal) and the degree of skeletal retardation (in weeks). The skeletal retardation seems a useful parameter to determine the minimal duration of insufficient energy supply to the fetus.
The Developmental Response of the Ductus arteriosus to Oxygen
Authors: Clyman RonaldIan , Mauray Françoise , Wong Louise , Heymann Michael A. , Rudolph Abraham M.
Published: September 2009

We studied the isometric contractile effects of increased PO2 on isolated rings of lamb ductus arteriosus (from three different gestational age groups). When rings were stretched to initial lengths that result in a maximal contractile response for rings in that age group, the oxygen-induced contraction was 5.91 ± 0.72 g/mm2 ( ± SEM, n = 18) in animals older than 135 days, 5.55 ± 1.23 g/mm2 (n = 18) in animals between Ill and 130 days, and 3.85 ± 0.75 g/mm2 (n = 19) in animals between 87 and 110 days. Only in the most immature vessels could a decrease in the tissue’s response to oxygen be observed.
Effect of Maternal Glucose Infusions on Fatty Acid Transport across the Placenta in Rabbits
Authors: Elphick M.C. , Edson J.L. , Hull D.
Published: September 2009

Glucose infusions given intravenously to 28-day-pregnant rabbits increased maternal and fetal plasma immunoreactive insulin levels and decreased maternal concentrations of circulating free fatty acid (FFA). Fetal plasma FFA were only slightly depressed and umbilical venous-arterial concentration differences were unchanged both for total FFA and for individual fatty acids in the FFA fraction. The mean umbilical venous concentration was twice that of maternal levels in the infused group, but about the same concentration in untreated rabbits. It is concluded that the infused glucose, or the high insulin levels provoked by it, or both, caused an increased flow of FFA to the fetus, probably from sources other than the maternal plasma FFA.
Pulmonary and Circulatory Function in Preterm Lambs Treated with Hydrocortisone in utero
Authors: Thibeault Donald W. , Emmanouilides George C. , Dodge Michael E.
Published: September 2009

The effects of the in utero intravenous administration of hydrocortisone on postnatal lung function and pulmonary and systemic hemodynamics were studied in preterm fetal lambs and compared with those of non-treated animals of similar gestational ages. The results indicate that steroid-induced changes in lung pressure volume curves, although statistically significant, did not render the pretreated fetuses capable of surviving without ventilatory assistance. In addition, the ductus arteriosus in the steroid-treated lambs at 2 h of age was functionally closed or constricted regardless of gestational age. In contrast, in the untreated lambs the ductus arteriosus was widely patent and, especially in lambs of less than 120 days gestation, there was invariably a large left-to-right ductal shunt.
The Development of DT-Diaphorase in Rat Liver and Its Induction by Benzo(a)pyrene
Authors: Hommes F.A. , Everts R.S. , Havinga H.
Published: September 2009

The development of cytosolic DT-diaphorase – NAD(P)H dehydrogenase, quinone, EC 1.6.99.2 – and its induction by benzo(a)pyrene has been studied in rat liver. DT-diaphorase belongs to the late suckling cluster, because the largest increase in activity can be observed 18 days after birth. A considerable activity is present, however, in the neonatal period. The activity of the enzyme can be prematurely induced by benzo(a)pyrene. A lag phase of 10 h can be observed before the activity of DT-diaphorase starts to increase. This increase in activity proved to be sensitive to inhibitors of mixed-function oxydase and RNA and DNA synthesis.
Baroreceptor and Chemoreceptor Responses to Umbilical Cord Occlusion in Fetal Lambs
Authors: Siassi Bijan , Wu Paul Y.K. , Blanco Carlos , Martin Chester B.
Published: September 2009

11 fetal lambs with gestational age of 116–35 days were studied while connected to a membrane-oxygenator replacing the ventilatory function of the placenta. Progressive increase in arterial oxygen tension from 20 to 220 mm Hg resulted in progressive decrease in baseline heart rate and baseline arterial blood pressure indicating presence of chemoreceptor activity over this wide range of arterial oxygen tension. The effect of 60 sec complete umbilical cord occlusion was studied at progressively higher arterial oxygen tension and it was concluded that the chemoreceptor activity at fetal normoxic condition is very brisk and is markedly attenuated at hyperoxic levels. Although it was not possible to completely separate baroreceptor and chemoreceptor reflexes involved in cardiovascular response to umbilical cord occlusion, it is postulated that the chemoreceptor and baroreceptor reflexes are complimentary during cardiovascular responses to umbilical cord occlusion.
Effects of Upper Respiratory Tract Stimuli on Neonatal Respiration: Reflex and Single Neuron Analyses in the Kitten
Authors: Lucier Gregory E. , Storey Arthur T. , Sessle Barry J.
Published: September 2009

Respiratory effects of electrical and chemical stimuli applied to nerves or sites associated with the respiratory tract were tested in kittens aged 6–70 days. Cessation of respiration occurred especially with superior laryngeal nerve stimulation and infusion of water and sodium bicarbonate into the larynx. The apneic reflex was more powerful and prolonged than that previously noted in adult cats and was sometimes irreversible. Brain stem respiratory neurons of the neonate also showed marked susceptibility to these stimuli: the respiratory-related rhythm of 80% could be powerfully suppressed, and only 25% received excitatory inputs. The susceptibility of the neonatal respiratory system to these stimuli may have physiopathological significance in conditions such as the sudden infant (crib) death syndrome.
Skeletal Changes in the Condylar Cartilage of the Neonate Mouse Mandible
Authors: Silbermann Michael , Livne Erella
Published: September 2009

Histological and histochemical qualitative and quantitative determinations are provided concerning the skeletal changes taking place in the growth center of the mandibular condyle in the neonatal ICR mouse. This study followed the changes in both the major matrical components (collagen, acidic glycosaminoglycans and glycolipids) as well as in the various cartilage cells throughout the maturational period of the neonatal condyle. It was found that the transformation of neonatal condylar cartilage to its mature form involved a significant decrease in its acid glycosaminoglycan content concomitant with a rapid increase in its collagen content. In addition, significant quantitative changes were found within the zone of hypertrophic chondrocytes. The period of highest growth activity along the mandibular posterior vertical dimension (ramus) was between birth and weanling (3rd postnatal week). At this time interval, the adaptive abilities of the growing condyle appeared maximal. A high degree of correlation was noted between the overall reduction in the height of the condylar cartilage and that of its hypertrophic zone. Further, the increase in the ramal height was highly correlated with the structural changes characteristic of the neonatal condyle.
Secretory Proteins in the Perfused Human Placenta
Authors: Dancis J. , Ghosh N.K. , Jansen V. , Schneider H. , Fallon R.J. , Cox R.P.
Published: September 2009

A relatively simple perfusion technique of human placenta has been applied to the study of secretory proteins. Preferential secretion into the maternal circulation of human chorionic gonadotropin (HCG), human chorionic somatomammotropin (HCS), follicle-stimulating hormone (FSH), and placental alkaline phosphatase has been demonstrated, contrasting with the bidirectional secretion of progesterone. Evidence is presented for the net synthesis of HCS during perfusion. The technique offers advantages in the study of synthesis and secretion of placental materials.
Deacylation-Reacylation of Phospholipids by Rat Embryos and Their Associated Placentas
Authors: East J.M. , Chepenik K.P. , Waite Moseley
Published: September 2009

Homogenates and subcellular fractions of rat chorioallantoic placentas obtained on the 14th day of gestation were assayed for acyl-CoA: lysophospholipid acyltransferase activities using (14C)-linoleic acid, ATP, and CoA, or (14C)-oleoyl-CoA as acyl donor and 1-acylglycerophosphorylcholine or 1-acylglycerophosphorylethanolamine as acyl acceptor. We found that: (1) the Lands’ deacylation-reacylation cycle is present in the rat placenta, (2) the enzymes were concentrated in the microsomal fraction, and (3) the optimal conditions for in vitro assay of those enzyme activities were similar to those reported for adult tissues. Comparison of the acyl composition of phospholipids in maternal blood with those in placental homogenates revealed similarities which are consistent with a role for this cycle in vivo in placental uptake of phospholipids. That this cycle may function also in placental transformation of phospholipids, in vivo, is suggested by differences between the acyl composition of phospholipids in placental homogenates and microsomal fractions.
Monoamine Oxidase Inhibition and Recovery in the Mouse Brain at Various Ages after Birth
Authors: Samsa Joseph M. , Baker Peter C. , Hoff Kenneth M.
Published: September 2009

Mice between the ages of 1 day postpartum and adulthood were exposed to the monoamine oxidase inhibitors tranylcypromine and pargyline. The mice were killed at seven different times following drug injection and assayed in vitro for monoamine oxidase activity in four brain regions. Inhibition and recovery of monoamine oxidase activity varied by age, and with the two inhibitors used. During the early maturational period, the potential for new monoamine oxidase synthesis was greater than normal maturational patterns of increase would suggest; and during later maturation either the proportions of various monoamine oxidase forms or their rates of synthesis are different.
Maternal and Fetal Plasma Renin Activity during Ritodrine Infusion to the Mother
Authors: Erkkola Risto , Lammintausta Risto , Liukko Pekka
Published: September 2009

The effect of ritodrine to the mother on plasma renin activity (PRA) in the mother and fetus was examined in 10 mothers coming to elective cesarean section. 10 comparable mothers without ritodrine infusion served as controls. At the end of 2 h infusion of ritodrine, the mean maternal PRA was significantly (p < 0.001) higher than in the control group. Also the mean PRA levels in the umbilical vein (p < 0.001) and umbilical artery (p < 0.01) were significantly higher after ritodrine infusion to the mother than the respective levels in the control group.
Effect of Nicotine on the Development of Fetal and Suckling Rats
Authors: Hamosh Margit , Simon Morton R. , Hamosh Paul
Published: September 2009

Nicotine, administered at a dose of 100 μg/kg/day from day 14 of gestation, did not affect maternal food intake, weight gain, length of gestation, litter size or fetal development; however, a daily dose of 1 mg/kg led to smaller litter size and higher incidence of stillbirth. Continued maternal administration of nicotine (100 μg/kg/day) until 12 days postpartum did not affect newborn growth (body weight and length and size of heart and lung) during the first week after birth; during the second week, however, the nicotine-treated group lagged behind the controls. The stomachs of pups of nicotine-treated rats contained less food than those of controls; this difference increased with age, becoming more than 40% at 12 days. We suggest that lower milk production of nicotine-treated rats interferes with the normal development of the offspring during periods of rapid growth.
Postnatal Changes in Carbamylphosphate Synthetase-I and Ornithine Transcarbamylase Activities after Normal Birth, Premature Delivery and Prolonged Gestation in Rat Liver: Effects of Actinomycin D and Glucose
Authors: Gautier C. , Vaillant R.
Published: September 2009

The development of two urea cycle enzymes, carbamylphosphate synthetase-I and ornithine transcarbamylase was examined in neonatal rat liver. Normal birth on day 21.5 caused a marked increase of both activities as early as 4 h of extrauterine life. That increase occurred later in newborns delivered by cesarian section on day 21.5, but they exhibited a greater hepatic urea level. Premature delivery on day 20.5 caused a marked increase of both activities and hepatic urea level while prolonged gestation abolished these increases. The postnatal increase in both activities and in hepatic urea level was therefore dependent on a factor associated with birth. The in vivo administration of actinomycin D (2 μg) at birth did not abolish the postnatal increase of both activities. Moreover, the administration of glucose (25 mg every 2 h) to newborns delivered by cesarian section on day 21.5 abolished the postnatal increase of ornithine transcarbamylase activity and hepatic urea level 23 h later. It seems that the transient hypoglycemia and appearance of gluconeogenesis at birth were the physiological mechanisms involved in the postnatal induction of ornithine transcarbamylase activity.
Reincorporation of Iodinated Peptides in vivo and the Comparative Effectiveness of Tungstic and Trichloroacetic Acids in Peptide Separation
Authors: Jones R.E.
Published: September 2009

The absorption of 125I-bovine IgG after oral administration to young rats has been followed by gel filtration and quantitatively by TCA precipitation. The wide spectrum of protein derivatives crossing the gut wall have been utilised to compare the relative effectiveness of 10% TCA, and 1% tungstic acid, as reagents for the quantitative assessment of radioactive proteins and peptides. Radioactive iodide was the chief radioactive metabolite when 125I-labelled bovine IgG was fed to young rats, there was no significant incorporation of small radioactive metabolites into protein during a second exposure to the gut wall.
Effects of Low-Dose Prenatal Corticosteroid Administration on the Premature Rat
Authors: Frank Lee , Roberts Robert J.
Published: September 2009

Administration of dexamethasone (0.2 mg/kg/day) to the pregnant rat on days 19 and 20 of gestation has been found to have marked effects on the body and organ weight of fetuses delivered 1 day prematurely on day 21 of gestation. Longer-term dexamethasone treatment earlier in gestation (days 14–18) had even more pronounced effects on body and organ weights in rat fetuses delivered three days prematurely. Dexamethasone treatment for 2 days prior to delivery had no effect on the survival of 1-, 2- and 3-day premature rats. The marked inhibitory effect on organ and body weight observed in the premature rats resulted from prenatal steroid therapy approximating that used in human pregnancies (dexamethasone 0.2 mg/kg/day for 48 h prior to premature delivery).
Assessment of Ventilation-Perfusion Inequality by aADN2 in Newborn Infants
Authors: Corbet A.J.S. , Ross J.A. , Beaudry P.H. , Stern L.
Published: September 2009

The contribution (Qo/Qt) of gas-filled air spaces with reduced ventilation-perfusion ratio (VA/Qc) to the production of total venous admixture in nondistressed premature infants and newborn infants with transient tachypnea was assessed by the aADN2 and AaDO2. The mean value for Qo/Qt in both nondistressed prematures and infants with transient tachypnea was 0.08. In both groups this represented about 30% of total venous admixture.
Organic Acids in Urine from Preterm Infants
Authors: Conde C. , Mazzá M. , Almar J. , Seijo G. , Ballabriga A.
Published: September 2009

The organic acid excretion was studied in urine samples from 26 preterm infants on the 1st and 5th days of life and the results compared to those obtained in 5 samples from full-term neonates. Gas-chromatography-mass spectrometry with a computer system was the method used in this work. The acids tabulated were those more closely related to lactic acidosis and the Krebs cycle. Great variations were found in the excretion of these acids in preterm infants in contrast to the very homogeneous pattern obtained in full-term neonates.
Malonyldialdehyde Formation, Oxygen Consumption, Fatty Acid Composition in Newborn Platelets Stimulated by Thrombin
Authors: Del Principe D. , Gabriotti M. , Mastracchio F. , Menichelli A. , Giardini O.
Published: September 2009

The release reaction, the formation of malonyldialdehyde (MDA), the pattern of oxygen consumption, and the variation in fatty acid composition after addition of thrombin (1.67 U/ml) have been investigated in newborn platelets, comparing the obtained data with analogous values showed by adult platelets assumed as normal controls. Newborn platelets showed a release reaction 20% lower than that of controls. MDA formation, even in the presence of NEM and the burst in oxygen consumption, resulted to be similar in newborn and adult platelets (p > 0.3); the burst was also similar after the addition of thrombin (10 U/ml) in the presence of antimycin and aspirin. The ratio between formed MDA and oxygen consumption was 1:10 in adult platelets while it was 1:15 in those of newborns. The study of fatty acid composition demonstrated that in newborn platelets at rest, arachidonic acid is significantly in a higher concentration than in controls and that it decreases after stimulation with thrombin. It is concluded that the pathway of prostaglandins is normally stimulated by thrombin in newborn platelets.
Plasma Thyroid Hormones and Cholesterol in the Newborn of Genetically Different Types of Cattle in a Tropical Environment
Authors: O’Kelly J.C. , Wallace A.L.C.
Published: September 2009

The patterns of plasma concentrations of thyroxine (T4), triiodothyronine (T3) and cholesterol were determined in tropically adapted (ZX) and temperate (SH) breeds of cattle in the first 6 days of their lives in a tropical environment. T4 concentrations were high at birth and fell to within normal adult values at 6 days of age. In contrast, plasma cholesterol levels were low at birth and increased daily to the highest values on day 6. T3 levels increased from birth to maximum values at 12 h after birth and then declined progressively. The T4/T3 molar ratios were high at birth and decreased to lower values on day 2. T4 and cholesterol levels were higher (p < 0.001) in ZX than in SH calves, and in calves born in winter were higher (p < 0.001) in females than in males. There were significant (p < 0.001) animal within-breed differences in all parameters. The results are discussed with reference to the use of physiological and biochemical indices for the early selection of cattle suited to tropical conditions.
Perinatal Development of Gluconeogenic Enzymes in Rabbit Liver
Authors: Callikan Soomant , Girard Jean
Published: September 2009

Activities of the 4 hepatic gluconeogenic enzymes: glucose-6-phosρhatase, fructose-1,6-diphosphatase, pyruvate carboxylase, particulate and cytosolic phosphoenolpyruvate carboxykinase (PEPCK) have been measured in fetal rabbits (22, 25, 28, 30 and 31 days of gestation) and in fasted or suckling newborns (1 and 2 days after birth). Between days 25 and 31 of gestation, fructose 1,6-diρhosphatase and particulate PEPCK activities represent 50% of adult (pregnant female) activities, while pyruvate carboxylase is present at adult values during the same period. Glucose-6-phosphatase is low and cytosolic PEPCK absent in fetal liver until 30 days of gestation and increase significantly during the day preceding birth. All the enzymes show a further increase after birth independently of the nutritional status of the animals (starved or suckling).
Fetal to Maternal Transfer of Palmitic and Linoleic Acids across the Sheep Placenta
Authors: Noble R.C. , Shand J.H. , Bell A.W.
Published: September 2009

Maternal and fetal blood samples were obtained at 2.5, 10 and 20 min after the injection of 3H-palmitic acid and 14C-linoleic acid into the fetal circulation of pregnant ewes. 3H-palmitic acid was easily detected in the maternal circulation within 2.5 min after its injection into the fetus resulting in an appreciable accumulation in the maternal plasma by the 20th min after injection. In contrast the presence of 14C-linoleic acid in the maternal circulation was barely detectable over the 20-min sampling period. The concentrations of total lipid and unesterified fatty acids within the fetal plasma were considerably lower than in the maternal plasma thereby providing an adverse concentration gradient for the passage of fatty acids between fetus and mother. The differential permeability of the placenta to the passage of the 3H-palmitic acid and 14C-linoleic acid is discussed in relation to their passage from fetus to mother in non-ruminant species and the adverse essential fatty acid status known to exist in the developing ruminant fetus.
Plasma Renin Activity and Adrenal Angiotensin II Receptors in Fetal, Newborn, Adult and Pregnant Rabbits
Authors: Pernollet M.G. , Devynck M.A. , Macdonald G.J. , Meyer P.
Published: September 2009

Plasma renin activity (PRA) and adrenal angiotensin II receptors have been studied simultaneously in the rabbit at various stages of development. In the fetus both parameters show very low values but increase rapidly during the last 4 days of gestation. PRA reaches a maximal level in the early post-natal period but the concentration of adrenal angiotensin II receptors continues to increase further up to the adult state. In adult females, pregnancy results in an initial rise in PRA and adrenocortical angiotensin II receptors. However, PRA remains at a high level throughout the gestation period whereas the number of adrenocortical angiotensin II receptors decreases progressively as pregnancy progresses. The role of circulating angiotensin in the regulation of the concentration and affinity of its receptor sites is discussed.
The Pentose Phosphate Pathway in Brain during Development
Authors: Hakim A.M. , Moss G. , Scuderi D.
Published: September 2009

Sprague-Dawley rats were delivered in our laboratory and decapitated at ages varying between 1 and 60 days. The concentrations of 6-phosphogluconate in extracts of the brain were determined in these litters and in adult rats. The highest content of 6-phosphogluconate was seen in brains of 3-day-old rats when it was at that age more than six times the adult level. Turnover rates for this same compound were determined by an in vitro technique at ages 1, 3 and 12 days and in the adult. We conclude that the pentose phosphate pathway is more active in rat brain during early development than in the adult, with a peak occurring at 3 days of life, indicating a possible link to nucleic acid synthesis.
Free Amino Acid Levels of Mother and Child Immediately after Delivery in Dar es Salaam, Tanzania
Authors: Boersma E.R. , Blom W. , Massawe A.W.
Published: September 2009

The pattern of the free serum amino acids was analysed in 20 healthy mothers immediately after delivery and from their term appropriate for gestational age infants in cord blood. The free amino acid concentrations were higher in Tanzanian women, when compared to Swedish standards, whereas slightly higher or similar values were found in cord blood, resulting in a marked reduction of the fetal/maternal ratio for the individual amino acids. It is suggested that under ‘basal nutritional conditions’ the reduced placental gradient could be one of the compensatory mechanisms to facilitate an adequate supply of amino acids to the human fetus. The validity of the glycine/valine index to recognize early protein malnutrition in pregnant women and their offspring or in small for dates is disputed.
Factors Affecting Glucose Turnover and Utilization in the Neonatal Subhuman Primate (Macaca mulatta)
Authors: Robinson Brian H. , Sherwood Geoffrey , Mayes Susan , Freire Evelina , Oei Jos , DiBattista David
Published: September 2009

The rate of glucose turnover (RT) has been studied in 33 subhuman primate newborn (Macaca mulatta). There appears to be a linear relationship between RT and plasma glucose (G) such that RT = 1.053 G + 0.242. Liver enzymes show a change in specificity such that hexokinase is predominant in the preterm animals and glucokinase has little activity, while in the term animal these enzymes are of equal activity. In the 1-year-old animal glucokinase predominates. Hexokinase activity in the brain remains constant throughout development. These results imply that low blood glucose in the neonate is not associated with increased glucose utilization.
Factors Affecting Gluconeogenesis in the Neonatal Subhuman Primate (Macaca mulatta)
Authors: Sherwood Geoffrey , Robinson Brian H. , Mayes Susan , Freire Evelina , Oei Jos , DiBattista David
Published: September 2009

The capacity for gluconeogenesis has been studied in 33 subhuman primate newborn (Macaca mulatta) in the basal steady state. Basal blood glucose levels were seen to rise with increasing postnatal age. Availability of the major gluconeogenic substrates, alanine and lactate, was adequate at times when blood glucose and the rate of gluconeogenesis were low. Hepatic and renal cortical content of the four key gluconeogenic enzymes was low during the 1st week of life compared to adult levels. Diminished induction of the gluconeogenic enzymes did not appear to be the cause of low blood glucose levels. The serum-free fatty levels were directly correlated to both the basal glucose levels and to the rate of gluconeogenesis.
Prematurity in the Rat
Authors: Cuezva J.M. , Moreno F.J. , Medina J.M. , Mayor F.
Published: September 2009

Changes in liver glycogen, plasma glucose, lactate, alanine and glycerol concentrations during the first 2 h after delivery by cesarean section in term and preterm rats were studied. Liver glycogenolysis initiated in both groups just after delivery, the rates of glycogenolysis being about 50 μmol/h/g wet weight. Glycogen breakdown came along with very low plasma glucose concentrations suggesting that glycogenolysis could be promoted by neonatal hypoglycemia. Plasma alanine concentrations decreased in both groups at similar rates suggesting that alanine utilization was enhanced during the first 2 h of extrauterine life. The plasma glycerol concentration increased in preterm rats but no changes were observed in term rats. The plasma lactate concentration progressively decreased during the first 2 h in term rats. However, preterm rats showed no changes in plasma lactate concentrations during the first hour, then decreased during the second hour at similar rates to those observed in term rats. These results suggest that preterm rats showed a transient resistence to lactate utilization at delivery which was overcome during the first hour of extrauterine life.
Hyperviscosity in the Small-for-Gestational Age Infant
Authors: Hakanson David O. , Oh William
Published: September 2009

Small-for-gestational age infants are prone to hyperviscosity but the precise incidence is unknown. A prospective survey was conducted on 4,974 consecutive livebirths for hyperviscosity in small-for-gestational age infants. Small-for-gestational age is defined as birth weight below the 10th percentile of the intrauterine growth curve and signs of malnutrition and hyperviscosity as venous blood viscosity (measured by a microviscometer) above the 2 SD of the norm. 79 infants were identified as small-for-gestational age. Of these, 14 were hyperviscous and 65 were normoviscous. The venous hematocrit range from 61 to 70% in hyperviscous and 37 to 62% for normoviscous. A predefined symptom complex referrable to cardiovascular, respiratory, gastrointestinal, and central nervous systems were assessed by an unbiased observer; 57% of hyperviscous and 25% of normal viscous infants were symptomatic (p < 0.05 by χ2). The data indicate that the hyperviscosity syndrome occurs in 17.7% of small-for-gestational age infants; venous hematocrit (64%) is predictive of hyperviscosity, and that in spite of a positive correlation between symptom complex and hyperviscosity, there is a lack of specificity for the clinical manifestation of this neonatal complication.
Thyroid Hormone Relationships in the Fetal and Newborn Lamb
Authors: Mathur H. , Brown B.L. , Krane E.J. , Thomas A.L. , Nathanielsz P.W.
Published: September 2009

Plasma thyroxine (T4) and reverse triiodothyronine (rT3) concentrations have been measured in chronically catheterised sheep fetuses during the last third of gestation. In some animals T4 and rT3 concentrations fell before delivery but there was no change in the T4/rT3 ratio. In several serially sampled fetuses a small rise in plasma triiodothyronine concentration has been demonstrated in the days preceding delivery. Infusion of cortisol to fetuses commencing at 130 days of gestation (term 147 days) with the simultaneous administration of progesterone to delay labour resulted in changes, in T4 and rT3 concentrations which were similar to those normally seen at term. The nature of the changes in the peripheral metabolism of T4 around the time or birth are discussed.
Compensatory Adrenal Hypertrophic Response in Fetuses of Calorie-Malnourished Rats
Authors: Lee Melvin , Eguchi Yasunobu , Arishima Kazuyoshi , Chan Kenneth K.-Y.
Published: September 2009

Fetuses of ad libitum fed and calorie-restricted rats were unilaterally adrenalectomized on day 19. By day 20 ad libitum fed fetuses exhibited compensatory adrenal hypertrophy, but calorie-restricted fetuses did not. As this may be due to the elevated corticosteroid levels of the calorie-restricted dams, unilateral adrenalectomy was performed on fetuses of control and restricted rats bilaterally adrenalectomized on day 15. Fetuses of restricted and control rats exhibited compensatory hypertrophy. One effect of calorie restriction may be to increase the amount of maternal corticosteroids acting on the fetus.
Ontogeny of the Inflammatory Response in the Fetal Rat
Authors: Gruber Benjamin , Esterly John R.
Published: September 2009

Fetal rats of 16, 17 and 18 days gestation (dg) were injected with turpentine or Streptococcus faecalis in 1% India ink. Specimens of peritoneal tissues and exudates were collected at 24, 48 and 96 h after injection. Inflammation was present in some of the youngest animals (16 dg) 24 h after injection with bacteria. The response consisted of infiltrates of polymorphonuclear (PMN) and mononuclear (MN) cells in tissues adjacent to the peritoneum. Inflammatory cells were also found within the peritoneal cavity. Phagocytosis of ink particles and bacteria was noted in these cells and in cells of the serosa and adjacent mesenchyme. Free peritoneal cells were not seen in littermate controls. Phagocytosis was also noted in PMNs and MNs in the exudates collected at 48 h. A more marked granulocytic response was seen in animals sacrificed 24 h following bacteria-ink injection at 17 dg. Inflammation was more extensive and consistent by 19 dg. The reaction to turpentine was associated with the variable degree of tissue injury noted in histologic sections. The gestational age at time of injection was a more important determinant of the magnitude and character of response than was the duration of the lesion.
Tyrosine Hydroxylase Activity and Catecholamine Content in the Adrenals of Young Hypo- and Hyperthyroid Rats
Authors: Gripois D. , Klein C. , Valens M.
Published: September 2009

The weight, the tyrosine hydroxylase (TH) activity and the catecholamine (noradrenaline and adrenaline) content of young rat adrenals have been measured from birth to 20 days after birth in relation to hypo- and hyperthyroidism. Hypothyroidism impairs the adrenal growth, while hyperthyroidism has no effect on the adrenal weight. Hypothyroidism is associated with an enhancement of TH activity and catecholamine content. In hyperthyroid rats, the increase in TH activity and catecholamine content is slower than in controls. In adult animals, TH activity and catecholamine content are less affected by thyroid function.
Fetal Development in Relation to Gestational Age in the Piglet
Authors: Flecknell P.A. , Wootton R. , Cooper J.E. , John M. , McFadyen I.R.
Published: September 2009

Body and organ weights were measured in piglets from 44 litters which had been delivered by caesarean section at various times during the last 20 days of gestation. An attempt has been made to assess the usefulness of these measurements as predictors of gestational age. In this series of animals there was a highly significant correlation between mean litter weight and age. However, a considerable degree of uncertainty about the true gestational age must be accepted if mean litter weight is to be used as the sole predictor: at a mean litter weight of 1 kg, the 95% confidence limits were found to be ± 10.2 days. No extra information was afforded by the inclusion of the organ weight data once the mean litter weight was known.
The Complement System of the Newborn Infant
Authors: Drew John H. , Arroyave Carlos M.
Published: September 2009

Whole complement activity (CH50), and levels of some components of the classical (C1q, C4, C3) and alternative (factor B and properdin) pathways were determined in 55 non-infected and 11 infected newborn infants. Normal newborn infants were lower than adults in all complement measurements; pre term infants being significantly lower than term infants. Complement was not effected by intrauterine growth retardation. Absence of C3 split products indicated that the deficiencies were developmental and not due to activation of the complement system. Complement levels were lower in infected infants and this was due to activation of the complement system as C3 split products were present in 54%. Because of the high incidence of split products in infected infants, incorporating a test to determine their presence may be of benefit in the diagnosis of the presence of infection in newborn infants.
Systolic Blood Pressure in Normal Newborn Infants during the First 6 Hours of Life: Transcutaneous Doppler Ultrasonic Technique
Authors: Lagler U. , Duc G.
Published: September 2009

Systolic blood pressures of 72 normal newborn infants were taken immediately, as well as 60, 120, 240 and 360 min after birth, using the transcutaneous Doppler ultrasonic technique. The mean values lie between 56 ± 9 and 61 ± 9 mm Hg and are presented graphically. This method is recommended for routine use in the delivery room.
Postnatal Development of Jejunal Sucrase: Independence from Cyclic AMP
Authors: Henning Susan J.
Published: September 2009

It has previously been shown that jejunal sucrase activity becomes increasingly responsive to glucocorticoids between the postnatal ages of 4 and 15 days. This study examines the possibility that cyclic AMP is the mediator of the increasing responsiveness. When dibutyryl cyclic AMP was administered concomitantly with glucocorticoid to rat pups aged 6 days, there was no enhancement of sucrase activity in pups sacrificed either 30 or 54 h later. To check for short-lived effects of cyclic AMP, pups aged 5 days were pretreated with glucocorticoid for 2 days to elicit sucrase activity, then received dibutyryl cyclic AMP by injection and were sacrificed 1, 3 and 6 h later. Once again there was no effect of cyclic AMP on sucrase activity. The final approach was to use cholera enterotoxin to stimulate epithelial adenylyl cyclase in jejunal segments in vivo. Under these conditions the stimulation of fluid secretion served as positive evidence that intracellular concentrations of cyclic AMP were elevated. However, once again there was no stimulation of sucrase activity. It is concluded that cyclic AMP does not mediate the increasing responsiveness of the developing intestine to glucocorticoids.
25-Hydroxycholecalciferol 1α-Hydroxylase Activity in the Kidney of the Fetal, Neonatal and Adult Guinea Pig
Authors: Fenton Enid , Britton H.G.
Published: September 2009

Homogenates of fetal, newborn and maternal kidney and placenta have been compared with homogenates of non-pregnant adult kidney for their ability to hydroxylate 25- hydroxycholecalciferol. The activity in the fetal kidney near term is similar to that in the mother and 4–5 times that in the non-pregnant adult. These differences from the non-pregnant adult are significant (p < 0.05 and 0.1 fetus and newborn, respectively). Even higher levels are present in some newborn 12–24 h after birth, but these values fall towards the non-pregnant level in the following 21 days. Significant hydroxylating activity is present in the near-term placenta.
The Influence of Inhibition of Prostaglandin Synthesis on Hippurate Extraction in Conscious, Newborn Lambs
Authors: Hoskins Edward J. , Mendoza Stanley A. , Friedman William F.
Published: September 2009

The influence of indomethacin (INDO) on the renal extraction of hippurate (EH) was studied in 12 conscious, newborn lambs divided into two groups based upon age. EH was measured before and after INDO (7.5 mg/kg i.v.) by collecting blood samples from both the abdominal aorta (opposite the renal artery) and renal vein (under fluoroscopy). In the youngest group (0–4 days, n = 5), control EH was 18 ± 8% (mean ± SE) and increased to 29 ± 6% following INDO (p = NS). In the older animals (2–3 weeks, n = 7) control EH was 66 ± 5% (p < 0.001, compared to the 0–4-day-olds) and decreased to 57 ± 4% following INDO (p < 0.02). The results suggest that EH increases during the first weeks of life and that prostaglandins may play a role in regulating the tubular transport of hippurate.
Classification of Threatened Premature Labor Related to Treatment with a Prostaglandin Inhibitor: Indomethacin
Authors: Atad Jack , David Amnon , Moise Jacob , Abramovici H.
Published: September 2009

68 patients complaining of premature uterine contractions were treated with a prostaglandin synthetase inhibitor – indomethacin. This agent had a marked effect on uterine contractions suppressing them completely after 1–8 h from the administration of the drug. Classification of the premature uterine contractions according to a scoring system method is analyzed in this study. The score classified the patients into three groups and enabled us to treat them with a correct dosage and period according to the clinical findings at admission of the patients. Indomethacin treatment was effective in all the 68 patients. The drug was well tolerated by all the patients with minimal side effects. The outcome of the newborns was satisfactory, and laboratory tests on various systems of the pregnant women and newborns were normal during and after treatment with indomethacin.
Renal Response to Alterations in Dietary Phosphate in the Young Beagle
Authors: Russo Janita C. , Nash Martin A.
Published: September 2009

Hyperphosphatemia is present in the young of many species compared to adult animals. We studied the renal response to alterations in dietary phosphate in 4- to 7-day-old beagle puppies. Puppies were phosphate restricted with oral aluminum hydroxide gel (Group I) or phosphate loaded with oral sodium phosphate (Group II). Puppies in both groups had hyperphosphatemia (Group I 8.6, Group II 12.2mg/dl) relative to adult dogs (3.4–4.8 mg/dl). Plasma phosphate concentration (P) and rate of excretion of phosphate (Ep) were independent of glomerular filtration rate (GFR). At any filtered load of phosphate Ep was greater and rate of reabsorption less in Group II independent of P. The maximal rate of phosphate reabsorption (TmP) was higher in Group I (100 μg/ml GFR) than Group II (26 μg/ml GFR). Negative values for phosphate reabsorption in 4 animals support the presence of a secretory mechanism for phosphate. Relative hyperphosphatemia in the puppy is not secondary to a renal limitation in phosphate excretion. The 1- to 2-week-old puppy adjusts renal reabsorption of phosphate to maintain a concentration of phosphate in plasma higher than in the adult animal. The renal alterations in response to variations in dietary phosphate occur independently of plasma phosphate concentration, GFR, or filtered load of phosphate.
Effect of Theophylline on the Riboflavin-Sensitized Photodegradation of Bilirubin in vitro
Authors: Meisel P. , Amon I. , Hüller H. , Jährig K.
Published: September 2009

Under in vitro conditions, theophylline accelerates the rate of bilirubin photodestruction sensitized by riboflavin, but does not do so in absence of this dye. The effect depends on the concentrations of theophylline and/or riboflavin, on the bilirubin/albumin ratio, and seems to implicate bilirubin unbound to serum albumin. Possible causes of the theophylline action and clinical implications regarding the phototherapy of neonatal jaundice are discussed.
Relationship of 2,3-Diphosphoglycerate and 2,3-Diphosphoglycerate Mutase in Various Mammals
Authors: Chemtob Sylvain , Gibb William , Bard Harry
Published: September 2009

To investigate a possible mechanism involved in the regulation of 2,3-diphosphoglycerate (2,3-DPG) synthesis, 2,3-DPG mutase (DPGM) was measured in different mammals presenting large differences in 2,3-DPG concentration between fetal, neonatal and adult life to see if the activity of this enzyme, necessary for 2,3-DPG synthesis, was related to the levels of 2,3-DPG. The data demonstrated that the minimal levels of 2,3-DPG in the adult sheep are likely due to the very low levels of DPGM. Also these findings show that the increases in 2,3-DPG levels, found in the newborn sheep during the 1st week of life, in adult rabbit and guinea pig when compared with their fetuses, are not due to an increase in levels of the DPGM.
Urinary Loss of Oxypurines in Hypoxic Premature Neonates
Authors: Jensen Mogens Henning , Brinkløv Morten Mygind , Lillquist Kaj
Published: September 2009

The daily urinary excretion of the oxypurines hypoxanthine, xanthine and uric acid during each of the first 3 days of life was determined in premature infants without hypoxia (PI) and in hypoxic premature infants (HPI) with the respiratory distress syndrome. The loss of uric acid was statistically significantly greater in the HPI during days 1, 2, and 3 of life, and so was the loss of xanthine on days 1, and 2, but not on day 3. As to the loss of hypoxanthine, no difference could be shown. In both groups of infants the excretion of hypoxanthine and xanthine together made up about 2% of the total oxypurine loss for each day, the loss of xanthine being the greater of the two. The results did not seem to bear relation to differences between the two groups concerning urinary output, birth weight, gestational age, method of delivery, or administration of exogenic purines. So it appears that the increased loss of oxypurines in HPI is caused by the impact of hypoxia, probably owing to the compromised cellular respiration with a subsequent general displacement of the purine metabolism in the catabolic direction.
In vitro Response of Glycerol Metabolism to Insulin and Adrenaline in Adipose Tissue from Fed and Fasted Rats during Pregnancy
Authors: Chaves J.M. , Herrera E.
Published: September 2009

Pieces of lumbar adipose tissue from 19-day pregnant rats and their virgin controls were incubated in the presence of albumin, glucose, U-14C-glycerol, and either bovine insulin (200 μU/ml) or adrenaline (2.6 μM). The rate of glycerol release in the medium was augmented in both fed and 48-hour fasted pregnant rats. Insulin reduced this parameter in tissues from pregnant rats but not from controls. Adrenaline enhanced it in all groups, especially in tissues from fed pregnant rats. The rates of CO2, fatty acids and glyceride glycerol formation from glycerol were higher and the effect of insulin was greater in pregnant than in control rats when fed. Fasting produced a decrease in all these parameters, the effect being greater in pregnant than in control rats. The augmented sensitivity of adipose tissue from the mother allows for a rapid switch from the anabolic to the catabolic state according to the necessities of the fetus.