bluuebunny/crossref_metadata_2025 huggingface dataset:
Heat Production in the Newborn Ox during Noradrenaline Infusion
Authors: Thompson G.E. , Bell A.W.
Published: September 2009

There have been conflicting reports about the existence of non-shivering thermogenesis in the newborn calf of domestic cattle. The present experiments show that intravenous infusion of noradrenaline (1 μg·kg––1·min––1) causes a large increase in the temperature of perirenal adipose tissue, and a smaller increase in mixed-venous-blood temperature of calves. The animal’s total oxygen consumption increases and respiratory quotient decreases. On the first day of life the noradrenaline produces a large temperature difference between adipose tissue and blood, and a large increase in total oxygen consumption. This response disappears with age, with great variation between individual animals.
Amino Acid Pools in the Feto-Maternal System
Authors: Velázquez Anselmo , Rosado Adolfo , Bernal Alfonso , Noriega Luis , Arévalo Noel
Published: September 2009

The determinations of the amino acid pools, including tryptophan (by fluorescence spectrometry), in the arterial and venous blood of the mother, the arterial and venous blood of the fetus (cord blood), the amniotic fluid and the placenta was done in eight women at the moment of delivery. Only nine amino acids (asp, try, met, phe, ser, cys, lys, gly, thr) were significantly retained and four (arg, glu, pro and glu-NH2) were significantly released by the fetal tissues. In contrast with this behavior most amino acids were retained by the maternal tissue, try, phe and hist showing the highest retention. When the amino acids are grouped as essential and nonessentials, the maternal tissues retained both categories without apparent discrimination, while the fetal tissues retained essential amino acids preferentially. Our results emphasize the importance of the placenta as the regulating system of the fetal milieu under normal conditions. Thus human fetal blood levels of amino acids are patterned after the placental ones and not after the maternal values obtained at the same time. It is apparent that the placenta seems to function as a nonspecific retention filter for outgoing amino acids, but that its function is selective in respect to the release of amino acids into the fetal circulation.
Influence of Early Weaning on the Activity of Several Enzymes in the Liver of Rat
Authors: Palkovič Michal , Macho Ladislav , Škottová Nina , Hoštacká Anna
Published: September 2009

In normally weaned rats the activity of two enzymes in rat liver, i.e. ATP citrate lyase and malic enzyme, gradually increases between the end of the third and the beginning of the fourth postnatal week. The activity of mitochondrial α-glycerophosphate oxidase remains unchanged during this period. Early weaning on the 18th postnatal day causes a rapid increase in activity of these enzymes. The impulse for this increase is very probably the change from high fat milk diet to high carbohydrate standard laboratory diet, the decrease of blood lipids, the activation of thyroid gland and changes of sensitivity of hepatic cells towards thyroid hormones. These results showed that early weaning modifies to the known picture of physiological weaning to a great extent.
Development of Gluconeogenic Enzymes in the Newborn Guinea Pig
Authors: Robinson B.H.
Published: September 2009

The activities of key gluconeogenic enzymes in the liver of newborn guinea pigs delivered vaginally at term were monitored as a function of time following birth. The activities of glucose-6-phosphatase and fructose-1,6-diphosphatase did not show a significant increase over the first 72 h of life, neither did the activity of mitochondrial phosphoenolpyruvate carboxykinase. The mitochondrial enzyme pyruvate carboxylase and the cytosolic phosphoenolpyruvate carboxykinase (PEPCK) both increased significantly in the first 24 h postpartum. Mitochondrial protein and succinate dehydrogenase activities showed only slight increases in the 72-hour period. Rapid depletion of liver glycogen was evident in these animals following birth, but severe hypoglycaemia was not evident. Mitochondrial and cytosolic PEPCK showed similar kinetic behaviour with respect to their affinities for oxalacetate and divalent metal cation Mn++, though the mitochondrial enzyme would accept Mg++ as the divalent metal in place of Mn++. The role of the compartmented PEPCK activities is discussed.
Cholestasis Associated with Administration of L-Amino Acids and Dextrose Solutions
Authors: Zarif Mehrunnisa A. , Pildes Rosita S. , Szanto Paul B. , Vidyasagar D.
Published: September 2009

Infants of very low birth weight who require prolonged assisted ventilation are unable to tolerate oral feedings. To provide and maintain nutrition in these infants, a modified form of parenteral nutrition (dextrose 10% and crystalline L-amino acids, 1.7–3.4 g%) is used in our nursery. Intrahepatic cholestasis was diagnosed at autopsy in four infants who received modified peripheral alimentation and in a fifth infant who received total parenteral alimentation (dextrose 20%, L-amino acids 3.8 g%) via a central venous catheter. These infants weighed less than 1,250 g at birth (range 943–1,247 g) and were appropriate for gestational age. They required assisted ventilation for over 2 weeks. Three infants did not receive any oral feedings. L-Amino acids were given for a mean of 36.8 ± 10 days (range, 22–76 days). The diagnosis of cholestasis was suspected clinically in only one infant, in whom persistent elevation of direct bilirubin was detected at 4 weeks of age. Pathologic findings in four infants included the presence of bile casts in bile canaliculi and, in one case, in ductules and canaliculi. Liver architecture was well preserved. Inflammatory infiltrate in the portal tract was either absent or minimal, consisting of lymphocytes, and only in one of five cases a few eosinophils. Cholestasis may be regarded as a possible complication of parenteral alimentation even if the fluids are modified and given peripherally. High direct bilirubinemia may be the earliest clinical manifestation.
The Regulatory Effect of Estrogens on Fetal Growth
Authors: Abdul-Karim Raja W. , Pavy Michael , Beydoun Samir N. , Haviland Mary E.
Published: September 2009

Brain weights and DNA, RNA, and total protein concentrations were determined on 31-day-old fetuses whose growth had been accelerated incidental to estrogen deficiency following maternal oophorectomy. Compared to controls, there were no differences in the DNA, RNA, or total protein concentrations, although the mean brain weight was increased. The higher mean brain weight in the growth accelerated fetuses was related to the increased mean fetal weight, and did not represent an independent response to the estrogen deficiency. A comparison of the influence of fetal weight versus gestational age on the weight of the fetal brain shows that gestational age exerts an effect apart from that of fetal weight.
Amniotic Fluid Surface Tension during Pregnancy
Authors: Rubaltelli Firmino F. , Rondinelli Mario , Zorzi Carlo , Saia Sergio
Published: September 2009

A good correlation between the amniotic fluid surface tension and gestational age was found in 51 amniotic fluid samples from normal pregnancies. The samples were obtained between the 20th and 43rd week of gestation. A good relation also exists between amniotic fluid lecithin concentration and fluid surface tension, and between said surface tension and the foam test carried out according to Clements et al. (4).
Effects of Recurrent Postnatal Stresses on Hypothalamic Concentrations of Norepinephrine
Authors: Torda Clara
Published: September 2009

The effect of recurrent postnatal stress on the norepinephrine content of hypothalamus has been studied. Repeated exposure to hunger or to stimulation of the lateral nucleus of the hypothalamus served as stress-producing process. Regardless of their nature, recurrent stresses increased the norepinephrine content of the hypothalamus. The differences between controls and stressed animals were statistically significant.
pH and the Level of Calcium in the Blood of Fetal and Neonatal Albino Rats
Authors: Krukowski Marilyn , Smith Jethroe J.
Published: September 2009

Near-term rat fetuses in utero are acidotic and hypoxic, and have high levels of total serum calcium. In the first hour of postnatal life, pO2 and pH increase and pCO2 and calcium fall. Between 1 and 4 h following birth, respiratory gases vary little, whereas pH continues to rise and calcium further declines. By 4 h, newborns reach normal pH levels but are markedly hypocalcemic. It is suggested that the Ê»hypercalcemia’ of intrauterine life is related to acidosis in utero, and that following birth, the initial fall in serum calcium is associated with the blowing off of CO2 and a concomitant rise in pH. The later decline in circulating calcium is independent of alterations in respiratory gases and relates directly to the final correction of neonatal acidosis.
Prostaglandin Biosynthesis in the Human Umbilical Cord
Authors: Jonsson C.-E. , Tuvemo T. , Hamberg M.
Published: September 2009

The content of prostaglandins (PGs) in homogenates of arteries, connective tissue from human umbilical cords, and the capacity for biosynthesis of PGs in these tissues were studied. Lipid extracts were prepared and subjected to chromatography on silicic acid columns. PGs were eluted by ethyl acetate after elution with ethyl acetate benzene (1:9) and determined by bioassay. For studies of the content of PGs, the cords were immediately frozen after delivery and homogenized in cold ethanol. Cords taken at vaginal deliveries contained amounts equivalent to approximately 700 ng prostaglandin E2/g dry weight and cords taken at caesarean sections about 450 ng/g. After homogenization and incubation of arteries in potassium phosphate buffer at 37 °C for 30 min the PG content increased from about 80 to 200 ng/g. Addition of arachidonic acid increased the biosynthesis fivefold. Indomethacin inhibited it. Most of the smooth muscle stimulating activity of the homogenated cords was due to prostaglandin E compounds, but smooth muscle stimulating material similar to prostaglandin F1α and F2α was also present. Prostaglandin E2 was conclusively identified by gas chromatography – mass spectrometry. The findings are compatible with the view that local biosynthesis of PGs is very active in the human umbilical cord after delivery.
Heterogeneity of Pituitary and Endogenous Plasma Human Growth Hormone from Fetuses, Premature and Full-Term Newborns
Authors: Eshet R. , Assa S. , Laron Z.
Published: September 2009

Fetal and adult human growth hormone (HGH) extract from human pituitaries as well as plasma from premature and full-term newborns and children were submitted to chromatography on Sephadex G-75 and the immunoreactive HGH (IRHGH) in the elution fractions was determined quantitatively by radioimmunoassay. Three fractions of IRHGH could be differentiated according to the elution pattern: Ê»big-big’, Ê»big’ and Ê»little’ IRHGH. In fetal pituitary extract only Ê»big-big’ and Ê»little’ IRHGH were found, whereas in adult pituitary extract all three forms of IRHGH were present. In the plasma samples studied no Ê»big-big’ form was found; only Ê»big’ and Ê»little’ IRHGH appeared. In addition, plasma samples of premature newborns had a smaller proportion of the Ê»big’ IRHGH than did those of the full-term newborns and older children.
Precursor and End Product Effects upon Indoleamine Maturation in Mouse Brain
Authors: Hoff Kenneth M. , Baker Peter C. , Buda Robert E.
Published: September 2009

The effects of tryptophan loading and the acid transport inhibitor, probenecid, on the maturation of 5-hydroxytryptamine (5-HT) and 5-hydroxyindole acetic acid (5-HIAA) have been studied in the maturing mouse brain. Tryptophan loading elevates already high endogenous tryptophan at all stages studied. It does not alter 5-HT or 5-HIAA at day 1 but does elevate levels of both at later stages. Probenecid does not affect 5-HT at any age or 5-HIAA at day 1, but does cause increasingly greater elevations of 5-HIAA at later stages. The results indicate that tryptophan-5-hydroxylase is substrate saturated in early postnatal stages but not later, and that the early postnatal brain lacks an acid transport mechanism for 5-HIAA egress but develops this at later stages.
Thyroid Hormone and Cell Formation in the Developing Rat Cerebellum
Authors: Legrand J. , Selme-Matrat M. , Rabié A. , Clos J. , Legrand C.
Published: September 2009

Effects of neonatal hyperthyroidism on cell formation in the developing rat cerebellum were reinvestigated. Administration at birth of excessive doses of thyroxine or triiodothyronine led to an early stimulation of cell acquisition, followed by a permanent deficit of cells in the cerebellum. The corrective effects of physiological doses of thyroxine on the troubles of the histological and biochemical development of the cerebellum in thyroid-deficient animals were also studied. As early as 6 days, cell maturation and formation were already retarded in animals treated with propylthiouracil, but, as previously reported, cell formation was prolonged and the final number of cells was normal. Administration to thyroid-deficient animals of progressively increasing doses of thyroxine, nearly equal to the amounts of hormone secreted by the thyroid gland of the developing normal rat, returned the evolution of the cerebellar wet weight and of the cerebellar DNA to normal, as well as the histological maturation of the cerebellum, even if it did not entirely correct the retardation of body growth. These results are consistent with the view that thyroid hormone early stimulates maturation of the cerebellar germinative cells and subsequently interacts with cell formation in the cerebellum, and that this action is physiological.
Changes in the ECG and Somatosensory-Evoked EEG Responses during Intrauterine Asphyxia in the Sheep
Authors: Rosén K.G. , Hrbek A. , Karlsson K. , Kjellmer I. , Olsson T. , Riha M.
Published: September 2009

Progressive changes in the S-T interval of the fetal ECG were studied in 14 mature lamb fetuses, acutely exteriorized and submitted to a graded hypoxia. The degree of hypoxic stress was measured from changes in the somatosensory-evoked EEG responses (SER), blood gas analysis and lactate concentration. The ECG and the SER were found to be affected simultaneously. A close relationship was further obtained between pH of the arterial blood and changes in the S-T interval, the ratio between the T and S waves being used for quantifying these changes. This relationship was further strengthened by the strong correlation obtained between the accumulation of lactate and the T/S ratio. The findings corroborate the hypothesis that the hypoxic changes in the ECG pattern could be regarded as a sign of myocardial glycolysis and early hypoxic stress.
Plasma Glucocorticoid Concentrations after Injections of Heroin, Corticotrophin, Saline, and Cortisol in Fetal and Neonatal Rabbits
Authors: Taeusch, jr. William , Patterson Andrew , Williams Laura , Colle Eleanor
Published: September 2009

Concentrations of plasma glucocorticoids were measured in fetal and newborn rabbits at various stages of late gestation after injections of heroin, saline, ACTH, or glucocorticoid. No change in blood corticoid levels were found in response to injections of these substances in rabbit fetuses, nor were corticoid levels altered in full-term newborn rabbits by heroin injection. ACTH in premature newborn rabbits was associated with a minimal increase in corticoids, although survival of the premature newborn rabbits was insufficient to allow measurement of corticoids at a time when ACTH effect might be maximal.
Kinetics of Insulin-Stimulated Accumulation of Glucose by Heart Cells from Newborn Rats
Authors: Clark Julia F. , Clark, jr. Charles M.
Published: September 2009

Cells isolated from the hearts of newborn (1-day-old) rat accumulate 14C-glucose. Insulin stimulates glucose accumulation by the heart cells. Values for net accumulation of glucose by heart cells agree well with those values obtained earlier using whole hearts. Lineweaver-Burk plots of initial rates of glucose accumulation at different concentrations of glucose show that the effect of insulin is to increase the Vmax. It is concluded that the effect of insulin is to increase the rate of glucose accumulation rather than to alter the concentration of glucose required to half-saturate the system. Glucose accumulation is also stimulated by mild trypsin digestion of the cells. Increasing concentrations of concanavalin A inhibit glucose accumulation.
Intrauterine Malnutrition and IgG Allotypes in the Rat
Authors: Olusi S.O. , Wallwork J.C. , McFarlane H.
Published: September 2009

IgG2b allotype could not be detected by immunodiffusion and immunoelectrophoresis in the sera of newborn rats. It would appear that IgG2b allotype does not cross the placenta while IgG2a does so readily. Intrauterine malnutrition causes prolonged impairment of synthesis to both IgG allotypes and this impairment could not be corrected by refeeding.
Relationship between Concentrations of Human Chorionic Gonadotrophin (HCG) in Maternal Plasma, Amniotic Fluid and Fetal Cerebrospinal Fluid
Authors: Zondek Lilly H. , Zondek Theodor
Published: September 2009

The cerebrospinal fluid (CSF) of 14 fetuses of 13–24 weeks of gestation has been assayed for the presence of human chorionic gonadotrophin (HCG). The results demonstrated that small amounts of HCG were present in the fetal CSF and showed highest values at 13 weeks, gradually falling to very low values by 19 and 24 weeks of gestation. No correlation appeared to exist between HCG concentration in maternal plasma and HCG concentration in fetal CSF, whereas a significant correlation could be demonstrated between HCG concentration in amniotic fluid and HCG concentration in fetal CSF. It may also be suggested that the blood brain barrier for HCG is incompletely developed in the fetus but this problem requires further investigation.
Post-Natal Changes in Blood Glucose, Phosphopyruvate Carboxylase and Tyrosine Aminotransferase after Normal Birth and Premature Delivery in the Rat
Authors: Di Marco P.N. , Ghisalberti A.V. , Pearce P.H. , Oliver I.T.
Published: September 2009

The relationship between post-natal changes in blood glucose and hepatic enzyme induction was examined in the newborn rat after delivery in the last 3 days of gestation (22 days). A period of transient hypoglycaemia followed normal birth, delivery under ether anaesthesia on day 21 and delivery without anaesthesia on day 22. When fetuses were delivered without anaesthesia on days 20 and 21 the blood glucose concentration was low at birth, was constant for 3 h then increased at a rate similar to that observed for older animals. Phosphopyruvate carboxylase and tyrosine aminotransferase developed in utero after day 21 and at term the activities were high and increased immediately after birth. The time lag for the increase in enzyme activity shortened as gestation progressed. It is concluded that postnatal changes in blood glucose concentration do not have any specific effect on hepatic enzyme induction.
Plasma Esterase Development in the Perinatal Lamb
Authors: Bell J.U. , Van Petten G.R.
Published: September 2009

Ovine plasma cholinesterase and nonspecific esterase activities were determined during the last 45 days of fetal development and first 48 h of extrauterine life and compared to adult activities. Marked differences in the development pattern of these enzymes were found. Fetal plasma cholinesterase activity increased between 102 and 112 days gestation to approximately twice adult values and thereafter progressively decreased to adult levels at 48 h postpartum. In contrast, fetal nonspecific esterase activity at 102 days gestation was only about 8% of the adult activity; a steady increase in this activity was found from 102 days gestation to term. From term to 48 h postpartum there was a marked increase of nonspecific esterase activity but the activity at 48 h was still only about 25% of the adult value.
Maturation of Indoleamine Metabolism in the Spinal Cord of the Mouse
Authors: Hoff Kenneth M. , Baker Peter C. , Presnell Vicky , Rodville Lois
Published: September 2009

The maturation of various enzymes and intermediates of the 5-hydroxytryptamine (5-HT) biochemical pathway have been measured in the spinal cord of the mouse between 1 day postpartum and adulthood. During the early postnatal period, most components are adult-like or near adult-like, increase to levels greater than the adult by the second week, and return to adult levels thereafter. 5-HT, however, never exceeds adult level and does not attain it until week 4. The early maturation of 5-HT metabolism in the cord is in keeping with the caudal/rostral gradient of maturation in the brain. Possible reasons for this are discussed.
Thymus-Dependent Lymphocytes and Delayed Hypersensitivity in Low Birth Weight Infants
Authors: Chandra R.K. , Ali S.K. , Kutty K.M. , Chandra S.
Published: September 2009

The proportion of thymus-dependent (T) lymphocytes in the blood and the ability to mount cutaneous delayed hypersensitivity to a battery of antigens were evaluated in 50 low birth weight (LBW) infants when they were 3 months to 5 years old. There was a significant reduction in the number of T lymphocytes. Delayed hypersensitivity was impaired. The abnormalities were more pronounced in those with persistent growth retardation. It is suggested that continued postnatal depression of cell-mediated immunity in LBW infants may contribute to increased frequency of infections and imrnunopathological diseases.
Effects of Continuous Distending Pressure on Lung Volumes and Lung Mechanics in the Immediate Neonatal Period
Authors: Milner A.D. , Saunders R.A. , Hopkin I.E.
Published: September 2009

The effects of CPAP and CNEP on lung mechanics and lung volumes were investigated in a group of 12 healthy newborn infants. Both resulted in a mild suppression of respiration. The fall in TPR50 was far greater during CPAP than during CNEP. Both led to a one third fall in dynamic compliance. Approximately 50% of the distending pressure was transmitted to the mediastinal structures whether applied as CPAP or CNEP.
Water Content and Distribution in Intrauterine Growth-Retarded Newborn Rats
Authors: Brans Yves W. , Ortega Patricia
Published: September 2009

Body composition of 54 normally grown and 29 intrauterine growth-retarded rat fetuses was determined. Half the fetuses in each group were analyzed whole while in the other half abdominal contents were separated from carcasses before analysis. No differences in body composition of whole fetuses, carcasses and abdominal contents were evident between the two groups. Although the validity of using the rat as animal model for human intrauterine growth retardation appears to be questionable, analysis of our results in light of previously published data raises important questions that deserve further investigation.
Effect of Hypoxia on Monoamine Synthesis in Brains of Developing Rats
Authors: Hedner T. , Lundborg P. , Engel J.
Published: September 2009

Tyrosine and tryptophan hydroxylase activity was studied in the postnatal rat brain in vivo by measuring the accumulation of dihydroxyphenylalanine and 5-hydroxytryptophan, respectively after inhibition of L-aromatic amino acid decarboxylase with NSD 1015. With increasing age there was a significant increase in the amount of dopa and 5-HTP accumulated in the brain after administration of NSD 1015. After 30 min in a 12% oxygen environment there were significant reductions of tyrosine hydroxylase and tryptophan hydroxylase activity at 1, 14 and 28 but not 4 days of postnatal age. Further, the decrease in 5-HTP accumulation was significantly more marked at 14 and 28 days than at 1 day of age. Thus, the oxygen-dependent synthesis of the neurotransmitter 5-hydroxytryptamine seems to be less vulnerable in the early postnatal rat brain.
Developmental Pattern of Hepatic Uridine Diphosphoglucuronosyl Transferase Activity in Growing Male Rats
Authors: Hietanen Eino
Published: September 2009

Hepatic uridine diphospho(UDP)glucuronosyl transferase activity was measured in growing male rats to gain the developmental activity pattern of this enzyme catalyzing conjugation of xenobiotics and endogenous substrates. The activity was at a very low level at the age of 14 days showing a 10-fold increase to the age of 72 days whereafter a slight decrease of activity was observed. Simultaneously there was about 30% increase in the hepatic postmitochondrial supernatant protein content. The highly enhanced UDPglucuronosyl transferase activity during the growth may be caused by increased synthesis of enzyme protein or by changes in the micro-environment of the enzyme.
Oxygen Consumption of the Newborn Rabbit Treated with Pulmonary Surfactant
Authors: Wallin A. , Burgoyne R. , Enhorning G.
Published: September 2009

A method is described for measuring oxygen consumption of small animals. It was used for 151 newborn rabbits delivered on the 27th, 28th, 29th, and 30th day of gestation. Half of the neonates were given a pharyngeal deposition of a concentrated surfactant (SA) suspension prior to their first breath. The remaining neonates served as controls. The survival rate among the immature rabbits treated with SA was significantly higher. The treatment did not affect oxygen consumption in any age-group. With increasing maturity, the neonates consumed more oxygen, and the controls delivered on the 30th day of gestation consumed 29.6 ± SEM 4.2 ml oxygen per kilogram and minute.
Histological Observations on Thymic Development in Fetal and Newborn Mammals Subject to Intrauterine Growth Retardation
Authors: Lansdown A.B.G.
Published: September 2009

Fetal growth retardation resulting from maternal dietary protein deprivation (rats) or Coxsackie virus B3 infection in mid-pregnancy (mice) was associated with delayed thymic development. Histological examination revealed that less darkly staining small lymphocytes were present and that the thymus was not well organised into cortex and medulla as seen in the normal-weight fetuses. In preterm or neonatal piglets, the histological pattern of the thymus did not vary appreciably according to the body weight of the fetus. HassalΓs corpuscles were present and the tissues were well organised into cortex and medulla regions. Although fetal growth retardation in rats and mice leads to an apparent delay in the differentiation of the thymus, functional studies are necessary to understand the immunological significance of this finding.
Effect of Chronic Maternal Methadone Exposure on Perinatal Development
Authors: Zagon Ian S. , McLaughlin Patricia J.
Published: September 2009

The effect of perinatal exposure to methadone on body growth and brain development was studied in rat. Female Sprague-Dawley albino rats received daily intraperitoneal injections of 5 mg/kg dl-methadone-HCl during gestation and lactation. Body weights were reduced in drug-treated mothers during gestation and the first 2 weeks of lactation. No differences in gestation time, litter size, or infant mortality were recorded, however methadone-treated offspring grew more slowly than controls. Weight deficits persisted in rats observed 5½ weeks after cessation of drug exposure (group 1) and in animals continuing to receive daily intraperitoneal injections of 5 mg/kg (group 2). From birth to day 21, brain weight and length, cerebral width and cerebellar weight and width were generally smaller in methadone-exposed rats. Brain measurements of group 1 and group 2 animals on day 60 revealed a reduction in brain and cerebellar weights and cerebral and cerebellar widths from control values. Brain:body weight and cerebellum:brain weight ratios were similar to controls. Analysis of these results indicates that maternal methadone treatment retards the growth of young rats and affects brain development.
Fetal Exposure to 1:8 Dihydroxyanthraquinone
Authors: Blair A.W. , Burdon M. , Powell J. , Gerrard M. , Smith R.
Published: September 2009

A survey of 160 consecutive maternity cases showed that a high percentage of mothers had exposed their fetus to laxatives of the anthraquinone type at some stage during the pregnancy. Administration of 1:8 dihydroxyanthraquinone at the time of induction of labour with estimation of the substance in maternal urine, amniotic fluid and the first urine obtained from the baby, indicated that the substance is absorbed from the maternal gut, crosses the placenta and is excreted via the fetal kidney into the liquor. In mothers and babies most of the drug appeared as glucuronide. Fetal catharsis did not appear to occur and the reasons for this are discussed.
Iodoprotein and Iodoamino Acid Distribution in Pig Thyroid Tissues at Different Periods of Development
Authors: Etling N. , Gehin F.
Published: September 2009

A biochemical study of the thyroid tissue in pigs at various stages of development was undertaken. The iodine and protein concentrations, and the iodoamino acid content of thyroglobulin (TG) were determined. Expressed as μg 127I/100 mg wet tissue, the mean iodine content of pig fetus is 66.4, 89.2 in the piglet and 168 in the adult pig. TG accounts for 95% of total proteins; its content increases with age. Mean iodine content of TG is 0.70 μg 127I/100 μg in the fetus, 0.78 in the piglet and 0.97 in the adult pig. The average number of molecules of thyroxine residues is 1.6 in the fetus, 2.2 in the piglet and 3.5 in the adult. Average triiodothyronine residues are lower around birth than in the adult. At all stages of development, synthesis of thyroxine is less effective in the pig than in the human, relative to the iodine content of TG. In contrast to the human, iodinated compounds are not found at a very low level near birth, but TG and iodine content regularly increase.
Plasma Renin Activity and Its Postnatal Development in Preterm Infants
Authors: Richer Christine , Hornych Hélèna , Amiel-Tison Claudine , Relier Jean-Pierre , Giudicelli Jean-François
Published: September 2009

Immunoassayable plasma renin activity (PRA) was measured in 16 healthy preterm infants of different gestational ages. A total of 52 measurements have been performed between the second week of life and the date of the expected term. PRA was found markedly increased in preterm infants and a highly significative negative correlation with postmenstrual age was proved.
Metabolic Response to Fasting in Experimental Intrauterine Growth Retardation Induced by Surgical and Nonsurgical Maternal Stress
Authors: Levitsky Lynne L. , Kimber Anne , Marchichow Jo Ann , Uehara Jane
Published: September 2009

Experimental intrauterine growth retardation was produced in two groups of neonatal rats by maternal sham surgery or by maternal obligatory exercise during the last 5 days of gestation (forced swim). Both experimental groups of neonates had lower plasma glucose and higher plasma insulin levels than controls after a 4-hour fast. Fetal stunting may be produced by a variety of maternal stresses in the rat and may be associated with alterations in the hormonal and glycemic response to fasting. Studies of the metabolic effects of experimental intrauterine growth retardation must be interpreted with caution if control animals have been subjected to intrauterine stress.
Regulation of Cyclic Nucleotide Phosphodiesterase Activity in Rhesus Fetal Muscle
Authors: Beatty Clarissa H. , Herrington Paul T. , Bocek Rose Mary
Published: September 2009

In both fetal and adult rhesus muscle, low levels of guanosine 3’:5’-monophosphate (cyclic GMP; 0.25–5.0 μM) stimulated the adenosine 3’:5’-monophosphate (cyclic AMP)-phosphodiesterase (PDE) at low substrate levels; the fetal enzyme was more sensitive than the adult (supernatant and particulate fractions). At high levels of substrate cyclic AMP (25–100 μM), hydrolysis was not influenced by either 10 or 20 μM cyclic GMP but the fetal and adult series were equally inhibited by 40 μM cyclic GMP. In the supernatant fraction cyclic AMP inhibition of cyclic GMP hydrolysis increased with increasing cyclic AMP levels. There was no difference between fetal and adult muscle preparations in percent inhibition; however, in the adult series, the inhibition was noncompetitive whereas in the fetal series the inhibition was competitive. The Ki for cyclic AMP was 40 μM for fetal and 100 μM for adult cyclic GMP-PDE. The Vmax values for cyclic GMP-PDE and both cyclic AMP-PDE enzymes were higher in the fetal series.
Changes of Serum Gonadotropin Concentrations in Premature Babies Submitted to Phototherapy
Authors: Lemaitre Beatrice , Toubas Paul L. , Guillot Marcel , Dreux Claude , Relier Jean P.
Published: September 2009

In order to determine if phototherapy was influencing any change in plasma gonadotropin levels, we have compared a group of 8 premature infants (4 males and 4 females) who have been treated with phototherapy because of jaundice, to a control group of 6 premature infants who did not require phototherapy. During the third and fourth week of life, luteinizing hormone (LH) and follicule stimulating hormone (FSH), increased simultaneously in a significant range in phototherapy treated females. In the group of treated males, LH but not FSH increased significantly. Constant phototherapy and/or the sudden stopping of the treatment in the jaundiced premature newborn female is responsible for a marked and transient elevation of gonadotropins. A clear mechanism of the observed phenomenon with pathways including the retina, pineal gland and hypothalamus, is not apparent.
Postnatal Development of Cardiac Output Distribution Measured by Radioactive Microspheres in Rats
Authors: Štulcová B.
Published: September 2009

Distribution of cardiac output was measured in rats, 9, 18, 25, 42 and 64 days old, by means of 85Sr-labelled microspheres 15 μm in diameter. The fractions of the cardiac output supplying the heart, lungs, cerebrum, hindbrain, kidney, liver, spleen, stomach, small intestine, large intestine, bones and muscles of the hindlegs and skin were estimated. The values obtained were further related to the relative weights of the respective organs. The distribution of cardiac output changed with age, the changes being most pronounced in the brain, kidney and small intestine.
Superoxide Dismutase Activity and Lipid Peroxidation of the Rat Liver during Development
Authors: Yoshioka Tamotsu , Utsumi Kozo , Sekiba Kaoru
Published: September 2009

The present work was an attempt to understand the effects of oxygen toxicity in the early neonatal period and was performed using rat liver homogenate and mitochondria as examples of superoxide dismutase (SOD) activity and lipid peroxidation. SOD activity of the liver was extremely low during the fetal period and approximately the 5th day after birth. However, a rapid increase in the level of activity was observed from about the 10th day after birth. By the 20th day, this had reached 88% of the level in the adult rat. Peroxidated lipids, in an inverse relation to SOD activity, occurred at high levels during the fetal and early neonatal period, but rapidly decreased after the 10th day. It can be considered, therefore, that protection against oxygen toxicity is inadequate in such rat livers during the fetal and early neonatal periods, but that it is well established by the 10th day after birth.
The Development of Pyruvate Dehydrogenase in the Subhuman Primate Macaca mulatta
Authors: Robinson B.H. , Sherwood W.G. , Oei J.
Published: September 2009

The development of total pyruvate dehydrogenase activity in the subhuman primate, Macaca mulatta, was investigated in brain, liver, kidney cortex, and skeletal and cardiac muscle. Newborn primates delivered prematurely at 135 days of gestation had only 32% of this enzyme activity present in the brain compared to the full-term animal. Full-term animals were similar to adults. All tissues showed high activities of enzyme at 1 year of age compared either with neonates or adults. Kidney cortex showed an increase in activity from 807 ± 74 μmol/g/min in prematurely delivered neonates to a maximum of 3,769 ± 275 μmol/g/min in 1-year-old animals. The results are discussed in relation to the developing energy requirements of the tissues concerned.
Urinary Content of 3′,5′-Adenosine Monophosphate (cAMP) and Creatinine in Full-Term and Premature Infants
Authors: Maxwell G.M. , Dahlenburg G.W. , Rencis V.
Published: September 2009

Cyclic 3′,5′-monophosphate (c-AMP) and creatinine were measured in full-term and premature infants. In normals, values for c-AMP were highest on days 1 and 2 (1.3–1.5 nmol/ml) and decreased thereafter. In prematures the c-AMP values were significantly lower than in the full-term infants. There was a rough correlation with birth weight. Creatinine values were closely reflected by the c-AMP levels. Changes found in neonatal jaundice, hypocalcaemia, respiratory distress syndrome, and anoxia could be attributed to prematurity. No diurnal variation in c-AMP values was found.
Orotic Acid: Its Influence on Nuclear RNA and Microsomal Protein Synthesis in Brain Cells of Undernourished Rat Pups
Authors: Lipp K. , van der Meulen N. , Wenske G. , Linneweh F.
Published: September 2009

Malnourished rat pups were supplemented with orotic acid. RNA-synthesizing activity of isolated brain cell nuclei and microsomal protein synthesis was measured in vitro. A marked increase was found in the activity of nuclear RNA synthesis but not in microsomal protein synthesis after orotic acid treatment for 7 days.
Increased Adrenocortical Activity in the Newborn Rat
Authors: Corbier P. , Roffi J.
Published: September 2009

The evolution of adrenal weight, of the level of ascorbic acid and the levels of adrenal and plasma corticosterone were measured in the newborn rat at the moment of birth and during the hours that followed. Between 0 and 4 h, the absolute and relative weights of the adrenals decreased by 14 and 10%, respectively, and were even lower at 24 h. The amount of ascorbic acid in the adrenals decreases by 17% between 0 and 4 hours. Adrenal corticosterone levels dropped abruptly during the first hour of life, accompanied by an increase in the plasma levels of this hormone. These results suggest that during the initial hours of life, there is a significant stimulation of the adrenal cortex, probably connected to birth-related stress phenomena. An encephalectomy, leaving the pituitary in situ, or decapitation of the rat fetus during the last days of gestation impair the growth and endocrine activity of the adrenal glands. Normal adrenocortical function is restored by injecting hypothalamic extracts or ACTH at the time of surgery (9, 16). At the end of the gestation period, rat fetuses respond to such stimuli as epinephrine or formalin injection by depleting adrenal ascorbic acid levels 1 h after the stress (5, 24). The administration of ether, or laparotomy plus ether, on day 20 of gestation induce an immediate rise of fetal hypothalamic CRF and adrenal corticosterone (12, 27). All these results afford good evidence for an autonomous hypothalamic-hypophyseal-adrenocortical axis during the last days of gestation of the rat fetus. The purpose of the present report was to discover if the adrenal cortex was activated by the stress of labor and birth, as well as by adaptation of the newborn animal to new environmental conditions. The parameters examined were adrenal weight, the levels of adrenal ascorbic acid and corticosterone and the circulating corticosterone levels during the hours following birth.
Hyperbilirubinemia Connected with Parenteral Administration of Higher Amounts of Fluids in Premature Infants
Authors: Jirsová Věra , Janovský Miloš
Published: September 2009

During a study on the influence of different amounts of fluid intake on water and electrolyte metabolism in the first 3 days of life, a high incidence of hyperbilirubinemia was observed in infants receiving a large water load (150 ml/kg/24 h) intravenously. The amount of meconium excreted during the 3-day period in newborns with total parenteral alimentation was significantly lower than in controls. Hyperbilirubinemia is considered to be due to the enterohepatic circulation of bilirubin present in the retained meconium. The role of slight hemolysis and insufficient stimulation of choleresis is discussed.
Sympathetic and Parasympathetic Control of Heart Rate in Unanaesthetized Fetal and Newborn Lambs
Authors: Walker Adrian M. , Cannata J. , Dowling Margaret H. , Ritchie Blair , Maloney John E.
Published: September 2009

Development of autonomic nervous control of basal heart rate was studied in unanesthetized fetal lambs (93 days to term) and newborn lambs (2–29 days), using atropine and/or propranolol blockade. Fetal lambs showed a progressive increase in parasympathetic restraint of heart rate; vagal influence in the newborn lamb was similar to the term fetus. Sympathetic stimulation of fetal heart rate declined toward term, possibly due to the strongly increasing parasympathetic influence. Sympathetic influence in the newborn was similar to the early-gestation fetus. Intrinsic heart rate was about 185 beats/min throughout the fetal and newborn life span studied. Thus changes in basal heart rate resulted from a different balance of the sympathetic and parasympathetic components of the autonomic nervous outflow.
Oxygen Consumption of the Fetal Sheep in utero
Authors: Parer J.T.
Published: September 2009

Oxygen consumption was measured in 8 chronically instrumented fetal sheep by a combination of recently introduced techniques. Umbilical blood flow was measured by an electromagnetic flow transducer placed around the common portion of the umbilical artery. Blood representative of that in the umbilical artery was obtained from the distal aorta. The common portion of the umbilical vein was catheterized by direct puncture of the vessel at the base of the umbilicus. An accurate micromethod was used to measure oxygen content of blood from the umbilical vessels, and oxygen consumption was calculated by application of the Fick principle. The mean fetal oxygen consumption was 7.9 ± 1.8 ml O2/min/kg fetus.
Fetal Pepsinogens in Human Amniotic Fluid
Authors: Liebman William M. , Samloff Michael
Published: September 2009

The presence of group I (Pg I) and group II (Pg II) pepsinogens was determined in 59 samples of human amniotic fluid between 11 and 40 weeks of gestation. Pg I was present in all of the samples, while Pg II was present only in samples of gestational age 32 weeks or older. No differential pattern of the fractions was present, although the first fraction of Pg I was not present in any of the samples. The sequential appearance of Pg I and Pg II suggests their fetal origin and that the synthesis of Pg I by fetal gastric mucosa may precede that of Pg II, thus serving as a potential marker of fetal maturity.
Postnatal Development of Rats Born Preterm and Postterm
Authors: Bührdel P. , Willgerodt H. , Keller E. , Theile H.
Published: September 2009

Litters with 3 preterm, 3 term and 3 postterm littermates have been fed by one mother each. Fetal body weight continues to increase in utero if the normal gestational period is extended by 1 day. But this intrauterine weight gain is smaller than the postnatal weight gains of term rats of the same conceptional ages. While the body weights of term and postterm rats increase rapidly immediately after birth, there is a lag phase of 3 days in preterm animals. This delay in weight gain is not caught up during a period of 30 postnatal days. This appears to be due to malnutrition in the early postnatal period. After the 20th day of life, the weight gain markedly increases in all groups, indicating the effect of supplemental feeding in the weaning period.
Sequential Intravenous Glucose Tolerance: Responses of Newborn and Adult
Authors: Obenshain Scott , Isaccsohn Meir , King Katherine , Schwartz Robert
Published: September 2009

Acute sequential intravenous glucose tolerance tests were performed at an interval of 120 min in 12 normal fasting adults, 5 normal infants, and 6 infants of gestationally diabetic mothers. Glucose disposal (Kt) and plasma insulin elevations were remarkably similar in the paired adult studies. In contrast, the studies in all infants were highly variable although they had similar initial plasma insulin levels (< 10 μU/ml). The rates of glucose disposal in the infants (1.43 and 1.47%/min) were slightly slower than the adult rates (1.66%/min). The plasma insulin responses, in contrast, were higher and more sustained throughout the second half of the test in the infants as a group. There was remarkable heterogeneity in the responses of the infants which obscured any differences between the groups.
Thyrotropin, Prolactin and Growth Hormone Response to Synthetic Thyrotropin-Releasing Hormone in Newborn Infants
Authors: Delitala G. , Meloni T. , Masala A. , Corti R.
Published: September 2009

The effects of 50 μg synthetic thyrotropin-releasing hormone (TRH) intravenously on thyrotropin (TSH), prolactin (PRL) and growth hormone (GH) levels were studied in 8 normal male newborns during the first hours of life. Mean plasma GH concentrations were similar to baseline values during the period of study; on the contrary, plasma PRL and TSH values increased in all infants after TRH administration. These data demonstrate a normal pituitary reserve of PRL and TSH in the early period of human life.
The Postnatal Development of Rats Born Preterm and Postterm
Authors: Bührdel P. , Keller E. , Willgerodt H. , Theile H.
Published: September 2009

Groups of 3 preterm (duration of gestation 22 days), 3 term (23 days), and 3 postterm (24 days) rats have been fed together by 1 mother rat. The postnatal growth of liver, brain, heart and kidney has been studied up to the 30th day of life. The postnatal loss of water shows good correlation with the maturation of each organ. The postnatal loss of water is marked in brain and kidneys, but only slight in liver and heart. The pronounced growth spurt of the brain at the about 10th day of life is probably due to the opening of the eyes. The growth spurt of the liver at the 15th day may be due to the supplementary food at the time of weaning. The effect of intrauterine undernutrition in postterm rats is most strikingly demonstrated in the liver. Postnatal undernutrition in preterm rats causes a retardation of growth of the liver and kidneys.
The Rabbit during the Last Third of Gestation
Authors: Metzger P. , Brachet E.
Published: September 2009

Total lipid, protein and glycogen concentrations were determined for the diaphragm and interscapular brown adipose tissue of fetal (22–31 days of gestation) and neonatal rabbits. In the diaphragm, protein concentration doubles and lipid concentration drops to half its initial value during the period under study; the glycogen level reaches its maximal value at 27 days, and decreases thereafter. In the brown fat, the lipid concentration rises steadily until the immediate prenatal period; the protein concentration remains steady and the glycogen is highest at 29 days of gestation. Fetal plasma glucose and insulin levels increase steadily; there exists a positive correlation between fetal plasma insulin levels and fetal body weight.
Relationship between Fatty Acids and Lipid Peroxidation in Lungs of Neonates
Authors: Kehrer James P. , Autor Anne P.
Published: September 2009

Triglycerides from the lungs of neonatal rats and mice were found to contain large amounts of the polyunsaturated fatty acids, arachidonate (20:4) and docosahexaeonoate (22:6). These fatty acids were diminished or absent in the triglycerides from the lungs of adult rats and mice and both neonatal and adult guinea pigs. No age-related changes were observed in the fatty acid composition of lung phospholipids in any of these species. The presence of arachidonic acid and docosahexaenoic acid in lung triglycerides correlated with the ability of these lungs to peroxidize lipids in vitro in all species. Depletion of lung triglycerides in neonatal rats by fasting abolished this lipid peroxidizing activity.