bluuebunny/crossref_metadata_2025 huggingface dataset:
Cardiovascular Responses to Autonomic Blockade in Hypoxemic Fetal Lambs
Authors: Lewis Alan B. , Donovan Margaret , Platzker Arnold C.G.
Published: September 2009

The cardiovascular responses of 11 fetal lambs in utero to hypoxemia were evaluated before and after autonomic blockade. Hypoxemia was produced by lowering the maternally inspired oxygen or by progressive constriction of the umbilical cord by a cuff occluder. The animals were studied serially from 112 days’ gestation to term. Fetal carotid arterial pO2 fell from 24 to 12 torr and was accompanied by a 35% decline in heart rate and 32% rise in blood pressure. Parasympathetic blockade with atropine produced a 114% increase in heart rate in the hypoxemic fetuses compared to 26% in the normoxemic controls. Pretreatment with atropine prevented the hypoxemia-induced bradycardia without altering the hypertensive response. α-Adrenergic blockade resulted in a 22% decrease in blood pressure in the hypoxemic group, three times greater than the controls. Pre-hypoxemia α-blockade prevented the hypertension without affecting the fall in fetal heart rate. It is concluded that fetal bradycardia in response to hypoxemia is due to a direct increase in parasympathetic activity rather than secondary to a hypertension-induced baroreflex. The α-mediated increase in systemic vascular resistance and blood pressure may be a compensatory mechanism to maintain placental blood flow despite the decline in combined ventricular output.
The Origin of Plasma Proteins in Human Amniotic Fluid: the Significance of Alpha1-Antichymotrypsin Complexes
Authors: Burnett D. , Bradwell A.R.
Published: September 2009

12 proteins were studied in serum and amniotic fluid from 20 women in late pregnancy by two-dimensional immunoelectrophoresis. A close inverse relationship was observed between the amniotic fluid/serum concentration ratios of 11 proteins and their Stokes radii. These proteins enter the liquor from the maternal blood by molecular filtration. The concentration of Α1-antichymotrypsin in amniotic fluid was often higher than expected and the protein was often partially complexed. Α1-Antichymotrypsin is probably not actively secreted into amniotic fluid but may be selectively retained after complexing.
Zinc Concentration in Gravida’s Serum and Amniotic Fluid during Normal Pregnancy
Authors: Brandes Joseph M. , Lightman Abraham , Itskovitz Joseph , Zinder Oren
Published: September 2009

Zinc concentration was determined in maternal serum and amniotic fluid during normal pregnancy. The nonpregnant zinc concentration in the serum of about 110μg% decreases gradually during pregnancy to about half the normal level. Amniotic fluid zinc concentration shows a slight decrease and remains nearly constant until the 34th to 36th week of gestation, and then increases sharply (statistically significant) reaching the highest level at 40–42 weeks from the last menstrual period. The maternal-fetal metabolism of zinc, the various factors effecting zinc levels in maternal serum and amniotic fluid during pregnancy have been discussed in view of our results. These may serve as data base for further studies on the role of zinc in normal and patholgoical human pregnancies.
Effect of Inhaling 100% O2 on Ventilation and Acid-Base Balance in Cerebrospinal Fluid of Neonates
Authors: Davi Maria , Sankaran Koravangattu , Rigatto Henrique
Published: September 2009

If 100% O2 produces hyperventilation by increasing central CO2 due to cerebral vasoconstriction or diminished reduction of oxyhemoglobin, then, there should be a parallel decrease in alveolar and CSF PCO2 during O2 breathing in neonates. To test this hypothesis, we measured ventilation, alveolar PCO2 and CSF PCO2, pH and HCO2 before and 10–20 min after infants began breathing 100% O2. With 100% O2, minute ventilation increased from 0.193 ± (SE) 0.013 (n = 7) to 0.252 ± 0.013 liter/min/kg (p < 0.015), PACO2 decreased from 42 ± 2 to 38 ± 2 mm Hg (p < 0.005), CSF PCO2 decreased from 51 ± 1 to 44 ± 1 mm Hg (p < 0.015), and pH increased from 7.308 ± 0.013 to 7.354 ± 0.013 (p < 0.05). CSF bicarbonate decreased, but not significantly. These findings, showing a trend toward alkalosis, suggest that the neonate, like the adult man, induces hyperventilation during hyperoxia via an increase in PCO2 at the central level.
Circulating Plasma Protein Concentrations in the Fetal and Neonatal Sheep
Authors: Nathanielsz P.W. , Lowe K.C. , Beck N.F.G. , McNaughton Denise C. , Jansen C.A.M. , Thomas A.L. , Stanley C.J.
Published: September 2009

Fetal and neonatal ovine plasma protein and lactate dehydrogenase concentrations have been measured between 124 and 146 days gestation in the chronically catheterized fetal sheep and in the newborn lamb. Fetal plasma protein concentration ranged from 24.7 to 77.0 mg·ml––1 and increased at a rate of 1.65 mg·ml––1·day––1. In contrast, in the first 10 days of neonatal life plasma protein concentration fell steadily at a rate of 2.64 mg·ml––1·day––1. Fetal plasma lactate dehydrogenase concentration increased at a rate of 0.014 IU·ml-1·day––1 during the period of study. The increase correlated significantly with the rise in fetal plasma protein concentration. In contrast, in the newborn lamb no significant change in plasma lactate dehydrogenase concentration was observed during the first 10 days after birth.
Body and Organ Development of Young Rats Maternally Exposed to Methadone
Authors: McLaughlin Patricia J. , Zagon Ian S.
Published: September 2009

The effects of maternal methadone (5 mg/kg methadone-HCl) administration during gestation and/or lactation on gross body measurements, absolute and dry organ weights, and tissue water content were studied in 60-day-old Sprague-Dawley rats. Female offspring perinatally exposed to methadone had body weights and measurements that were comparable to controls, but male rats from each treatment schedule had at least one subnormal body measurement. In contrast to controls, methadone-treated rats had alterations in both wet and dry organ weights, with many organ weights of experimental animals being significantly higher in weight than those of controls. Few differences in tissue water content of any organ were observed between methadone-exposed and control rats. Calculation of organ weight gain from 21 to 60 days of age revealed that methadone-treated animals exhibited abnormally greater weight gains than controls during the postweaning period. These findings suggest that the growth deficits observed at 21 days are, to a large degree, not apparent at sexual maturity. The question of whether this ‘catch-up’ growth is qualitatively as well as quantitatively complete and the implications of these aberrant growth patterns on function needs further evaluation.
Vitamin E Serum Levels in Newborn Infants Undergoing Phototherapy
Authors: Hadjigeorgiou E. , Tzortzatou F. , Malamitsi-Puchner A. , Papadatos J. , Papadakis D. , Nicolopoulos D.
Published: September 2009

The serum vitamin E levels of 11 full-term and 10 premature infants, jaundiced and subjected to phototherapy, were measured and compared with 9 premature and 10 full-term jaundiced control infants. No differences were observed before or after phototherapy or 1 week after stopping it. The same negative results were noted in the two groups of infants regarding the values of microhematocrit, Hb and reticulocytes.
Lung Fluid Balance in Hypoxic, Awake Newborn Lambs and Mature Sheep
Authors: Bland Richard D. , Bressack Michael A. , Haberkern Charles M. , Hansen Thomas N.
Published: September 2009

To study the pulmonary vascular response to hypoxia and associated transvascular flow of fluid into the lungs of newborn lambs and mature sheep, we collected lung lymph and measured pulmonary vascular pressures and blood flow in 14 unanesthetized lambs and 9 sheep breathing 10–12% oxygen for 3–6 h after a 2-hour control period in air. In both groups of animals, pulmonary arterial pressure, blood flow, and lung vascular resistance increased with hypoxia, but only in lambs did the flow of lymph increase and the concentration of protein in lymph decrease with hypoxia. These results suggest that hypoxia increased transvascular filtration of fluid into the lungs of the lambs by increasing hydraulic pressure in the pulmonary microcirculation. In sheep, the vascular response to hypoxia did not increase lung fluid filtration. Hypoxia had no effect on microvascular permeability to protein in the lungs of either group of animals.
Effects of Dexamethasone on Fetal Mouse Development
Authors: Tye Lesley M. , Burton A.F.
Published: September 2009

The in vitro incorporation of 14C-leucine, 3H-uridine and 3H-thymidine into the acid-insoluble components of mouse fetal liver, gut, heart and lung was followed on gestational days 14, 16 and 19. Liver and gut showed a similar pattern: the incorporation of all three substrates decreased steadily until day 19, falling from one tenth to one fifth the values on day 14. Heart and lung decreased by half after day 16. Injection of mothers 16 h earlier with 200 μg dexamethasone decreased in vitro incorporation on day 14 into liver and gut, respectively, of leucine by 38 and 37% and of thymidine by 67 and 56%. In heart and lung, only thymidine was decreased at this time by 61 and 33%, respectively. Values for uridine were affected significantly only in liver. Thymidine incorporation appeared to be the most sensitive parameter reflecting corticosteroid action and liver the most sensitive tissue. Treated fetuses were born at the usual time and weight gain did not differ from controls over the first 42 days neonatally. It is concluded that dexamethasone accelerates the development of many processes in fetal tissues which are induced by corticosteroids.
Glycogen Deposition in Fetal Mouse Tissues and the Effect of Dexamethasone
Authors: Tye Lesley M. , Burton A.F.
Published: September 2009

Glycogen in fetal mouse tissues was isolated and determined using the anthrone method on gestational days 14–19. Fetal liver showed rapid glycogen deposition after gestational day 17, reaching a value of 46.7 mg/g wet weight on day 19. Heart and placenta showed sizable glycogen stores earlier, with peak values of 21.7 and 12.8 mg/g, respectively, on day 16 which declined thereafter. Lung maintained approximately 10 mg/g days 16–19; gut and brain contained approximately 2 and 4 mg/g, respectively, days 14–19. After injection of dexamethasone into mothers on gestational day 15.5, 16 h prior to assay, the glycogen content of liver increased approximately tenfold, while placental glycogen declined. This indicates that corticosteroids merely accelerate the pattern observed in the normal course of gestation.
Effect of Positive End-Expiratory Pressure on Dynamic Respiratory Compliance in Neonates
Authors: Philips Joseph B., III , Beale Ernest F. , Howard Jane E. , Jaeger Marc J. , Eitzman Donald V.
Published: September 2009

A simplified method of determining dynamic respiratory compliance (Cdyn) in the newborn is described. Studies were performed during mechanical ventilation on 24 infants with respiratory distress syndrome (RDS) and 6 infants without RDS. Cdyn was evaluated at pressure settings of 20/0, 25/5 and 30/10 cm H2O. Significant decreases (p < 0.05) in Cdyn were noted with each increase in end-expiratory pressure setting. The values for Cdyn in RDS patients obtained by this method closely approximated previously published data for lung compliance in babies with RDS. This simple and reproducible method may be useful in following the course of illness in infants with RDS.
Lysosomal Enzyme Activities of Human Fetal Organs during Development
Authors: Shin-Buehring Y.S. , Dallinger M. , Osang M. , Rahm P. , Schaub J.
Published: September 2009

The developmental patterns of four lysosomal enzymes have been investigated in liver, kidney, lung, heart, spleen, muscle and brain tissues of human fetuses at various gestational ages. The largest increment in the activity of all four enzymes, namely acid α-glucosidase, α-galactosidase, β-galactosidase and acid phosphatase has been observed in kidney with a 6- to 12-fold increase between the second and third trimester of gestation. The activity of all liver and spleen enzymes also increased considerably during these periods. In muscle, however, only α-glucosidase and acid phosphatase showed an increase in the activity, and in lung, acid phosphatase and β-galactosidase. Most of brain and heart enzymes, except acid phosphatase, did not change significantly during the observation period. The activities of these lysosomal enzymes were also measured in tissues of a normal adult individual, and aspects of the neonatal and postnatal development of these enzymes were discussed.
Fetal Metabolic Response to Phloridzin-Induced Hypoglycemia in Pregnant Rats
Authors: Freund Nicole , Kervran Alain , Assan Roger , Geloso Jean-Pierre , Girard Jean
Published: September 2009

Phloridzin, an inhibitor of renal sugar transport, produces an important loss of glucose in urine of treated animals. In order to reduce severely the maternal glucose supply to the fetuses in short-term experiments, we have combined phloridzin administration to pregnant rats with 18 h starvation. Fetuses from starved phloridzin-treated mothers were compared with fetuses from starved mothers. Combined treatment markedly decreases fetal blood glucose concentration (––36%) and fetal liver glycogen stores (––76%). These changes are associated with a decrease in plasma insulin (––25%), a rise in plasma glucagon (+120%) and a marked increase of hepatic PEPCK activity (+400%). It appears from these results that phloridzin treatment for a short duration is able to induce glycogenolysis and the premature appearance of PEPCK in the liver of rat fetuses.
Effects of Diets with or without Folic Acid, with or without Methionine, on Fetus Development, Folate Stores and Folic Acid-Dependent Enzyme Activities in the Rat
Authors: Potier de Courcy G. , Bujoli J.
Published: September 2009

Wistar female rats fed, since mating, with diets lacking either methionine, replaced in this case by homocystine (HF), or folic acid (MO), or both (HO). With diets lacking either one of the two factors, fetal weights remained in the range of the controls. When both factors were absent from the diet (HO), underweight fetuses were observed on day 20. In the offspring of folic acid-deficient mothers (MO), only folyloligoglutamates were lowered; total ones remained near control level. Switching HO females to a folic acid-supplemented diet from day 16 to 20 of pregnancy restored fetal weight and folates to the control level. The activity of folico-dependent enzymes of the whole fetal body or liver varied in parallel to fetal weight. We conclude from these data that: (1) methionine has a protective effect on folates in MO groups; (2) when folic acid is present in a diet containing homocystine but no methionine (MF), endogenous methionine synthesis is sufficient to cover maternal and fetal needs; (3) when the vitamin is also withdrawn (HO), methionine synthesis is no more adequate and fetal underdevelopment appears.
Hormonal Status in the Newborn Lamb (Cortisol, T3, T4)
Authors: Cabello G. , Levieux D.
Published: September 2009

The experiments reported involve 18 Romanov lambs born spontaneously between 135 and 145 days of gestation. Their birth weights ranged between 1.22 and 3.55 kg. The neonatal changes in plasma cortisol, triiodothyronine and thyroxine levels were observed from birth to 30 days postpartum, and related to the length of gestation and the birth weight. Positive correlations were found between: (1) plasma T3 (2, 4, 8 h and 11 days after birth), T4 levels (4 h after birth) and the birth weight; (2) plasma T3 levels (2, 4 and 8 h after birth) and the weight gain during the 1st month of life, and (3) plasma cortisol levels at birth, 8 and 48 h postpartum and the litter size. Negative correlations were found between: (1) plasma cortisol levels (at birth, 2, 4, 8 and 48 h postpartum) and the birth weight; (2) plasma cortisol levels (2, 8 and 48 h after birth) and the length of gestation, and (3) values of the T3/T4 ratio and the litter size. A tentative scheme of the interactions between litter size, hormonal plasma levels, length of gestation and birth weight is proposed. Moreover, the effects of placental insufficiency and insufficient plasma levels of thyroid hormones could explain partly the high frequency of disease which occurs in low birth weight lambs.
25-Hydroxyvitamin D3 Metabolism in the Pregnant Rat: Maternal-Fetal Relationships
Authors: Lester G.E. , Gray T.K. , Lorenc R.S.
Published: September 2009

Metabolism of 3H-25OHD3 was studied in pregnant, D-deprived rats and their fetuses at 21 days’ gestation. Significant changes in the circulating levels of 3H-24,25(OH)2D3 and 3H-1,25(OH)2D3 in maternal and fetal plasma occurred from 4 to 12 h after the administration of 223 ng of 3H-250HD3. 3H-1,25(OH)2D3 appeared before 3H-24,25(OH)2D3 in both the mother and fetuses. Maternal plasma contained more 3H-1,25(OH)2D3 than fetal plasma and, contrariwise, fetal plasma contained more 3H-24,25(OH)2D3 than maternal plasma. Maternal nephrectomy studies showed that the in vivo synthesis of 3H-24,25(OH)2D3 at 6 h was dependent on circulating levels of 3H-1,25(OH)2D3. These results revealed aspects of maternal-fetal metabolism of 250HD3 similar to those in the non-pregnant state as well as others unique to pregnancy.
Surfactant Phospholipid Ontogeny in Fetal Rabbit Lung Lavage and Amniotic Fluid
Authors: Torday John S. , Nielsen Heber C.
Published: September 2009

The development of pulmonary surfactant production by the fetal lung is essential for normal lung function at birth. Failure to produce an adequate amount of surfactant is associated with respiratory distress syndrome of the newborn (RDS). Prediction of the risk of RDS is based on the measurement of surfactant phospholipids in amniotic fluid. We have studied the ontogeny of surfactant phospholipids in the fetal rabbit by analyzing samples obtained simultaneously from lung lavage and amniotic fluid during late gestation (days 24–30). A surge in saturated phosphatidylcholine and percent saturation is observed first in lung lavage (day 26), followed 1.5–2.5 days later by a similar increase in amniotic fluid. These findings support the assumption that amniotic fluid surfactant phospholipids reflect the production of surfactant phospholipids in the developing lung.
A Comparison of the in vivo Metabolism of Phenothiazine and Promazine in the Neonatal Guinea Pig
Authors: Mitchell S.C. , Waring R.H.
Published: September 2009

The in vivo metabolism of promazine and phenothiazine was studied in neonatal guinea pigs aged 1–21 days. Urinary metabolites were estimated for both compounds; marked fluctuations with age were noted, some values being greater than those found for adult animals. Unconjugated phenol (C-oxidation products) levels were very low, although glucuronide excretion was always present; glucuronyl transferase activity did not appear to be limiting, and was present as early as 1 day after birth. Peak sulphoxide excretion showed no correlation with output of other metabolites, suggesting that S- and C-oxidation are not directly linked.
Effects of Phototherapy on Serum Unbound Bilirubin in Icteric Newborn Infants
Authors: Nakamura Hajime , Lee Yokei , Uetani Yoshiyuki , Kitsunezuka Yoshiki , Shimabuku Robert , Matsuo Tamotu
Published: September 2009

Sera from 39 preterm and 35 full-term infants with hyperbilirubinemia, undergoing phototherapy continuously for 48 h, were assayed for unbound bilirubin by the peroxidase oxidation method. Assessment was done to determine the influence of therapeutic exposure to light on the serum unbound bilirubin concentrations in preterm and full-term infants. At 24 and 48 h after initiation of phototherapy, the unbound/total bilirubin ratios, as well, as the serum total and unbound bilirubin levels showed statistically significant declines of values in both preterm and full-term infants. It is concluded that, following phototherapy, the serum levels of unbound bilirubin decline more conspicuously than the decrease in serum total bilirubin levels.
Localization of Tamm-Horsfall Glycoprotein in the Fetal and Neonatal Hamster Kidney as Demonstrated by Immunofluorescence and Immunoelectron Microscopical Techniques
Authors: Sikri K.L. , Foster C.L. , Alexander D.P. , Marshall R.D.
Published: September 2009

Tamm-Horsfall (T-H) glycoprotein was demonstrated in the developing hamster kidney using immunofluorescence and immunoelectron microscopical techniques. The glycoprotein was first observed in the fetal kidneys on the 12th day of gestation and was confined to the luminal surface of the presumed distal tubules of the medulla. It was not until the 14th day of gestation that T-H glycoprotein was also sometimes seen to be associated with the lateral and basal invaginations of the plasma membranes of the now differentiated distal tubules. On the 16th day (1st day post-partum) the glycoprotein was also found in the cortex. Although the general distribution of T-H gylocoprotein was at 3–4 days after birth similar to the adult, the full intensity of staining was not attained until after the 21st day. The possible physiological significance of these findings is discussed.
Effect of Maternal Diabetes on Response to Hypoxia in the Newborn Rabbit
Authors: Epstein Michael F. , Hartig-Beecken Imme , Loo Sherry W.
Published: September 2009

We tested the hypothesis that maternal diabetes is associated with a decreased ability of the newborn to tolerate hypoxia by measuring the time to last gasp of rabbit pups born to diabetic and control does and placed in 100% N2. Rabbits were made diabetic by injection of 100mg/kg alloxan i.v. The alloxan-treated mothers had significantly elevated blood glucose during pregnancy and at delivery (132 vs. 90 mg/dl, p < 0.001). Pups were delivered at 30 days’ gestation by hysterotomy under local anesthesia. Half of each litter were immediately sacrificed and the remaining pups placed in 100% N2. The pups from the alloxan-treated mothers showed a higher pre-asphyxial mean blood glucose (97 vs. 73 mg/dl, p < 0.025) and a lower mean survival time (18.4 vs. 21.1 min, p < 0.005).
Lymphocyte Infiltration of Gut Epithelium in Fetal and Neonatal Rabbits
Authors: Orlic D. , Gray B.A. , Carmichael R.D. , Baron P.
Published: September 2009

Lymphocytes infiltrate the epithelium of small intestinal villi of fetal rabbits as early as day 28 of gestation. They appear within the lateral spaces between the columnar absorptive cells. At this time, the epithelial cells transport compounds, such as injected horseradish peroxidase, through these intercellular spaces to the subjacent lamina propria. The possibility for in utero interaction between intraepithelial lymphocytes and antigen in swallowed amniotic fluid is discussed. There is an increase in the number of intraepithelial lymphocytes from 1 per 500 epithelial cells on day 1 to 16 per 500 epithelial cells on day 21 of postnatal life. Each segment, duodenum, jejunum and ileum, shows an increase in the number of lymphocytes during this period.
Chronic Maternal Hyperinsulinemia and Hypoglycemia
Authors: Gruppuso Philip A. , Migliori Richard , Susa John B. , Schwartz Robert
Published: September 2009

Chronic hypoglycemia was produced in pregnant rats during the last third of gestation through the constant infusion of insulin by a subcutaneously implanted, osmotically driven minipump. The offspring, delivered by cesarean section on day 20 of gestation, demonstrated intrauterine growth retardation compared to control fetuses. This effect was associated with fetal hypoglycemia and hypoinsulinemia. Fetal total and branch-chain amino acid concentrations were not affected. Increases in maternal to fetal glucose ratio and fetal insulin to glucose ratio in the experimental group were interpreted to indicate that limitation in the availability of glucose, a major fetal nutrient, was the basis for these effects.
Effect of Dexamethasone on Lipoprotein Lipase Activity of Fetal Rat Lung
Authors: Mostello Dorothea J. , Hamosh Margit , Hamosh Paul
Published: September 2009

Dexamethasone was administered by continuous subcutaneous infusions (16 μg/kg/h) to pregnant rats from day 16 of gestation. Administration of the hormone markedly affected maternal and fetal weight gain, fetal lung:body weight ratio and lipoprotein lipase activity of the lung. Cumulative maternal weight gain from days 15–21 of gestation was 80 ± 4.0 g in control and 30 ± 10 g in dexamethasone-treated rats. Fetal weight at 22 days of gestation and 1 day after birth was 5.5 ± 0.39 and 8.6 ± 0.30 in control and 4.65 ± 0.26 and 5.9 ± 0.34 in dexamethasone-treated rats. The ratio of lung weight to body weight was lower throughout the last 5 days of gestation in dexamethasone-treated than in control rats. Dexamethasone administration led to a 2- to 3-fold increase in lipoprotein lipase activity levels in fetal rat lung at 19 and 20 days’ gestation and prevented the decline in enzyme activity shortly before birth. Stimulation of fetal lung lipoprotein lipase activity suggests that increased uptake of triglyceride-fatty acids by the lung could be a contributory factor to corticosteroid-enhanced surfactant synthesis.
The Maternal Diet and Its Effect on the Lipid Composition and Osmotic Fragility of Neonatal Ovine Erythrocytes
Authors: Shand J.H. , Noble R.C.
Published: September 2009

Two groups of pregnant ewes were fed either a control diet or one in which part of the concentrate ration was replaced during the last 8 weeks of gestation with a protected polyunsaturated fatty acid (PUFA) supplement. The feeding of the PUFA diet resulted in significantly higher proportions of linoleic acid in the plasma lipids of the ewes and both linoleic and arachidonic acids in the plasma lipids of the lambs. The erythrocytes were composed almost totally of free cholesterol and phospholipids and, although no significant difference was observed in the overall phospholipid compositions of the erythrocytes from the two groups of lambs, there were differences from those of the adult. Fatty acid analysis of the erythrocyte phospholipids showed marked differences between ewes and lambs and also between the two groups of lambs. In particular, the proportions of linoleic and arachidonic acids were higher in the erythrocyte phospholipids from PUFA lambs compared with those from control lambs. This compositional change correlated with a greater resistance to haemolysis and it is suggested that this might be indicative of beneficial effects on the membrane stability of other cells.
The Effects of Maternal Carbohydrate (Sucrose) Supplementation on the Growth of Offspring of Pregnancies with Habitual Caffeine Consumption
Authors: Dunlop Marjorie , Court John M. , Larkins Richard G.
Published: September 2009

Reduced offspring growth was found following introduction of caffeine into the normal diet of rats during pregnancy and lactation. When maternal caffeine (10 mg/kg/day) was consumed together with supplementary sucrose (7 g/kg/day) the expected offspring growth reduction attributed to caffeine did not occur. It is concluded that maternal nutritional status may determine the outcome of caffeine exposure at low concentrations which mimic human usage.
Kernicterus at Low Levels of Serum Bilirubin: The Impact of Bilirubin Albumin-Binding Capacity
Authors: Pledger Derek R. , Scott Jean M. , Belfield Alan
Published: September 2009

A retrospective survey of neonatal postmortems over a 10-year period was made to establish the incidence of kernicterus and the associated laboratory abnormalities. Cases with evidence of kernicterus without hyperbilirubinaemia were found to have significantly lower reserve albumin-binding capacity (RABC) than the control group. The results suggest that RABC estimation is a necessary adjunct in the assessment of the jaundiced, low birth-weight neonate.
The Effect of Preweaning Undernutrition upon the Sexual Development of Male Mice
Authors: Jean-Faucher Christiane , Berger Michel , de Turckheim Marc , Veyssière Georges , Jean Claude
Published: September 2009

Sexual maturation was evaluated in male mice subjected to preweaning undernutrition by separating pups from their mothers. Underfed and normally fed males were sacrificed at 20, 30, 40, 50 and 60 days of age. From 20 to 60 days, body and organ weights (testes, seminal vesicle) were lower in underfed males. Plasma testosterone levels were lowered in undernourished males at 20 and 30 days of age, and thereafter they were not significantly different from controls. First fertile matings, which occurred between 36 and 46 days (mean age: 40.6 ± 0.6) in controls, were delayed in underfed males and occurred between 42 and 58 days (mean age: 48 ± 1.7). The mean body weight, at the time of first fertile matings, was significantly different in controls (29.5 ± 0.5 g, range 25.9–32.4) and in undernourished males (24.3 ± 0.3 g, range: 22.0–25.6). Testicular weight and plasma testosterone concentrations were also significantly lower in underfed males, at the time of first fertile matings. The data lead to the conclusion that puberty did not occur at the same body weight in normal and undernourished male mice.
Postnatal Surges in Plasma Gut Hormones in Term and Preterm Infants
Authors: Lucas A. , Bloom S.R. , Aynsley-Green A.
Published: September 2009

Using sensitive radioimmunoassays we have measured and compared plasma concentrations of motilin, gastrin, enteroglucagon, neurotensin, gastric inhibitory polypeptide and pancreatic polypeptide in (a) 53 healthy, preterm infants at birth or preprandially at 2.5, 6, 13 or 24 days; (b) 45 normal, breast-fed, term infants at birth or preprandially at 6 or 16 days, and (c) 12 healthy fasting adults. Plasma concentrations of all six hormones rose during the neonatal period in both preterm and term infants, the first four of these hormones reaching levels which exceeded those seen in healthy fasting adults. The rate of increase and the magnitude of the changes were less in term infants than preterm infants. These changes in plasma hormone concentrations may be the result of enteral feeding. Gut hormones exert important effects on gut growth, secretion and motility and on intermediary metabolism, and the postnatal hormonal surges observed may play a key role in the postnatal adaptions to enteral feeding.
Expiratory Patterns during Sleep in Normal Full-Term and Premature Neonates
Authors: Radvanyi-Bouvet M.F. , Monset-Couchard M. , Morel-Kahn F. , Vicente G. , Dreyfus-Brisac C.
Published: September 2009

Airflow (V), tidal volume (TV), and EEG polygraphic recordings were performed in 30 normal full-term newborns (FTN) and in 10 premature newborns (PN). Besides the classical expiratory flow (CEF), a retarded expiratory flow (REF) was observed: a phase of slow flow ending with a sharp increase. REF was mostly encountered in quiet sleep (QS) in FTN. During REF, Te and Ttot became longer; T, became shorter, with an increase in TV. In QS, sighs were more numerous in FTN with a high percentage of REF. Expiratory sudden short arrests of airflow (SSAA), < 2 s, during expiration were more frequent in active sleep (AS) in FTN. REF may be due to some obstruction or to postinspiratory diaphragmatic activity; variations in functional residual capacity may also be involved.
Proteolytic Activity as a Regulator of the Transmission of Orally Fed Proteins from the Gut to the Blood Serum in the Suckling Rat
Authors: Telemo E. , Weström B.R. , Karlsson B.W.
Published: September 2009

14-day-old rats were orally fed with porcine colostrum or serum having a low or high activity of protease inhibitors (i.e., sow colostrum trypsin-chymotrypsin inhibitor or soybean trypsin inhibitor). The uptake of undigested porcine albumin and IgG to the blood serum of these rats was studied 4 h after feeding. The effect of the exclusion of proteases to the intestinal lumen by means of pancreatic duct ligation prior to feeding was also studied. The results from these feeding experiments in the presence of protease inhibitors or in the absence of pancreatic proteases agreed well. It was concluded that for the suckling rat the intraluminal proteolytic activity in the gastrointestinal tract is a regulator for nonselective protein uptake, as represented by albumin, while the selective absorption of IgG was unaffected.
Blood and Tissue Levels of Lipoperoxides in Rats during Development
Authors: Yoshioka Tamotsu , Mori Mariko , Takehara Yoshiki , Shimatani Mie
Published: September 2009

The excessive accumulation of lipoperoxides has been accepted as being highly responsible for the development of retinopathy of prematurity and idiopathic respiratory distress syndrome of the newborn infant. We have studied development-related levels of lipoperoxides in blood and tissues such as the liver, lungs, kidneys and brain from birth to adult age using rats as the experimental animal. Lipoperoxide concentrations in blood and tissues were low in the fetal and early newborn periods. The concentrations increased with age and peaked in the early newborn period and gradually decreased as the development progressed. In vitro lipoperoxide formation and accumulation in tissues exhibited a close correlation with in vivo lipoperoxide concentrations, except in the brain.
Erythrocyte Enzymes in Sheep: Comparison of Activity in Fetal, Newborn, Maternal and Nonpregnant Ewe Erythrocytes
Authors: Noble N.A. , Cabalum T.C. , Nathanielsz P.W. , Tanaka K.R.
Published: September 2009

Hematological data and the activities of 21 red cell enzymes were measured in 8 nonpregnant ewes, 13 chronically catheterized fetuses at 125–135 days of gestation, and 8 of their mothers. In addition, 7 lambs were followed from birth to 17 days of age. Fetal sheep red cells have dramatically increased activities for 17 of the 21 enzymes measured compared with adult nonpregnant ewes. The pattern of decline of enzyme activities with development varies considerably among enzymes. The activity of seven enzymes showed an orderly decline from fetal to adult life. For seven enzymes very little or no decline in activity was observed between 125 and 135 days of gestation and birth. Pyruvate kinase activity declined to adult levels by birth. Phosphoglucose isomerase and nucleoside phosphorylase activity increased, and glutathione peroxidase activity decreased in newborn lamb red cells compared to fetal cells. Differences in blood cell variables were also found among these groups.
Exposure of Rats to Lead Nitrate in utero or Postpartum; Effects on Morphology and Behavior
Authors: Minsker D.H. , Moskalski Nancy , Peter Chennekatu P. , Robertson Richard T. , Bokelman Delwin L.
Published: September 2009

Female rats were administered lead (Pb), as the nitrate salt, on day 17 of pregnancy (5 or 25 mg/kg i.v.) or throughout lactation (5 or 25 mg/kg/day p.o.). There were adverse effects on weights of females receiving Pb on day 17. At 25 mg/kg i.v. gestation was significantly prolonged. In both groups treated intravenously, average pup weight on day 1 postpartum was significantly reduced and there was a significantly higher mortality than in controls, and hydrocephalus occurred. Survival rate and weight gain of pups from dams that received Pb throughout lactation was not different from controls. Brain weights and histomorphology of all groups was normal. Behavior in male offspring, as measured by open-field activity, rotorod or passive avoidance tests, was unaffected by exposure to Pb.
Blood Glucose of Mother and Fetus during Late Pregnancy of Rats with a Glycogen Storage Disorder
Authors: Watts Colin , Gain Kevin , Malthus Rex
Published: September 2009

The gsd/gsd rat is unable to mobilize liver glycogen due to an absence of phosphorylase b kinase activity. Unlike the normal rat, the maternal gsd/gsd rat cannot maintain its blood glucose concentration in late pregnancy, and values of 3.25 ± 0.22 mM were found just before birth. The blood glucose of the gsd/gsd fetus falls to 1.76 ± 0.09 raMat day 19 of gestation and does not rise appreciably again before birth. In contrast, normal fetal rats show a steady rise in blood glucose from hypoglycemic levels at day 19 to a value of 5.70 ± 0.12 mM on the day of birth. These results indicate that the normal fetal rat contributes towards the regulation of its own blood glucose in late gestation by utilizing its liver glycogen stores.
Accurate Measurement of Cerebral Metabolism in the Conscious, Unrestrained Neonatal Piglet
Authors: Flecknell P.A. , Wootton R. , John Muriel
Published: September 2009

Cerebral utilization rates of glucose and oxygen were measured in 18 conscious, unrestrained neonatal piglets. Cerebral glucose utilization rate was 26.9 ± 2.8 μmol/min/100g (mean ± SEM), cerebral oxygen utilization rate was 160 ± 10 μmol/min/ 100 g and the glucose to oxygen ratio was 1.03 ± 0.11, implying that glucose is the primary substrate for cerebral metabolism in the normal neonatal piglet at rest. These results are similar to the data obtained in the few studies of cerebral metabolism in the human infant and encourage the continued use of the piglet as a suitable animal model.
Development of Enzymes of Adenine Nucleotide Metabolism in Rat Brain and Liver
Authors: Andrés Antonio , Machado Alberto
Published: September 2009

The developmental changes in the activity of certain representative enzymes of adenine nucleotide metabolism, namely AMP deaminase, adenylate kinase and creatine kinase, have been studied in rat brain and liver. The principal points observed can be summarised as follows. (1) Fetal liver has a remarkably high AMP deaminase activity, which decreases immediately after birth. (2) The activities of both soluble and mitochondrial forms of brain creatine kinase are about 50-fold those of liver. The activities of these liver enzymes remain unchanged during the developmental period. In brain, however, these enzymes increase their activities about 3 and 5 times in the cytoplasmic and mitochondrial fractions, respectively. (3) The brain adenylate kinase activity from cytoplasmic fractions increased 4-fold during the 10- to 30-day period, whereas the enzyme from mitochondrial fractions remained unchanged.
Interrelationship of Insulin and Somatomedin Activity in Fetal Rats
Authors: Heinze E. , Nguyen Thi C. , Vetter U. , Fussgänger R.D.
Published: September 2009

The effects of glucose and glibenclamide on fetal body weight and fetal serum somatomedin activity were studied. From day 18 to day 20 post-conception, pregnant rats were continuously infused with saline or 40 % glucose, which raised the maternal blood sugar to about 200 mg/dl. On day 21 of gestation, fetal body weight was not different, while fetal serum somatomedin activity was significantly elevated in the hyperlycemic animals. Glibenclamide, 1 mg/kg body weight, was injected on day 20 of gestation to the rat mother. The sulfonylurea crossed the placenta. A daily glibenclamide injection from day 16 to day 20 post-conception did not change the fetal body weight, but it significantly augmented the fetal serum somatomedian activity. The results suggest that insulin stimulated the generation of somatomedian activity in the fetus. Both insulin and somatomedian may act as fetal growth factors.
Proteins, Vitamin A, Carotene, Folacin, Ferritin and Zinc in Navajo Maternal and Cord Blood
Authors: Butte Nancy F. , Calloway Doris Howes
Published: September 2009

Blood samples were obtained from 28 Navajo women at delivery and cord blood samples were collected from their healthy, full-term infants. The concentrations of retinol, folacin, ferritin and zinc in the cord blood fell in the normal range even though some mothers had blood levels suggesting a deficiency. Levels of maternal and cord blood retinol-binding protein were positively correlated. Although marginal and deficient levels of folacin in maternal blood did not result in significantly lower cord blood levels, the strong association indicated a dependence of fetal level upon maternal supply. Birth weight and the developmental indices were not related to any of the maternal or fetal nutrient levels.
Relationship of Plasma Total Bilirubin, Apparent Unbound Bilirubin and Total Albumin with Cerebellar Glycogen and Abnormal Purkinje Cells in the Gunn Rat
Authors: Karp Warren B. , Moore Pamela J. , Subramanyam S.B. , Brown Donna B.
Published: September 2009

Total plasma bilirubin, apparent unbound plasma bilirubin, cerebellar glycogen and Purkinje cells were quantified in heterozygous Gunn rats, homozygous Gunn rats and normal Wistar rats. Our results indicated that, in the Gunn rat, total bilirubin, apparent unbound bilirubin, and the bilirubin/albumin molar ratio are highly correlated with each other and with alterations in cerebellar Purkinje cells and accumulation of cerebellar glycogen. In addition, cerebella of heterozygous Gunn rats contained many abnormal Purkinje cells without intramitochondrial glycogen and cerebella of homozygous Gunn rats showed many Purkinje cells with intramitochondrial glycogen. Our results demonstrate previously unreported differences between heterozygous Gunn rats and controls. We suggest that a population of Purkinje cells in the heterozygous Gunn rats may have received a cellular insult from fetal exposure to bilirubin.
Morphine Treatment during Rat Pregnancy: Neonatal and Preweaning Consequences
Authors: Lapointe G. , Nosal G.
Published: September 2009

Morphine treatment during pregnancy was scheduled with the view to reproduce physical dependence in female rats and to investigate the occurrence of a neonatal withdrawal syndrome (NWS) as well as more prolonged effects of the narcotic in the preweaned pups. Administration started 5 days prior to mating with the daily dose of 20 mg/kg i.p. injections. All along gestation, the dosage was gradually increased up to the final dose of 56 mg/kg/day on the 16th day when the treatment was interrupted. Pregnant dams showed behavioral manifestations of narcotic dependence and drug abstinence. At birth, morphine-exposed neonates exhibited (1) an approximate 28% decrease in respiratory rates (p < 0.001) during the first day of life and (2) excessive crying (p < 0.001) accompanied by restlessness. These two last features are related to clinical signs of the NWS identified in babies born to narcotic-addicted women. A significant delay in the time of eye-opening and an earlier sexual maturation in females only were also found in the postnatally developing morphine offsprings. The NWS and some other developmental changes were considered in relation to the used animal model and to possible processes involved in narcotic interferences with postnatal physical growth and neurobehavioral maturation.
Stimulation of Serum Erythropoietic Activity in Rat Fetuses under Conditions of Glucocorticoid Deficiency or Excess
Authors: Nagel M.D. , Billat C. , Félix J.M. , Nagel J.
Published: September 2009

Fetal hepatic erythron misfunction, experimentally induced at the end of intrauterine life of the rat either by corticosteroid deprivation (fetal hypophysectomy following maternal adrenalectomy) or, on the contrary, by corticosteroid excess (repeated maternal stress), leads to an increase in serum erythropoietic activity detected with an in vitro fetal liver bioassay. This increase in serum erythropoietin-like substance may be related with the premature onset of bone marrow red cell formation observed under similar experimental conditions.
Correlation between Gestational Age and Fetal Activity Periods
Authors: Dierker LeRoy J. , Rosen Mortimer G. , Pillay Sasi , Sorokin Yoram
Published: September 2009

Cyclic patterns of active and quiet fetal activity were evaluated in 36 clinically normal gravidas between 27 and 42 weeks of gestation. All infants were subsequently delivered between 37 and 42 weeks of gestation, were clinically normal and of appropriate weight for gestational age. Active-quiet cycles occurred less frequently and were of longer duration with increasing gestational age. Regression analysis of the number of active-quiet cycles with gestational age yielded a correlation coefficient of 0.52 (p < 0.01). The similarity of fetal active-quiet cycles and active and quiet sleep cycles observed after birth is noted.
Colostral T Lymphocytes Detected by Intracytoplasmic and Membrane Markers
Authors: Pignata C. , Nespoli L. , Maccario R. , Siena S. , Mingrat G. , Mazzucco M. , Ugazio A.G.
Published: September 2009

Colostral lymphocytes were studied using two established T-cell markers: intracytoplasmic alpha-naphtyl-acetate esterase (ANAE) staining and membrane receptors for sheep erythrocytes (E rosettes). ANAE staining allowed counting and identification of T-cell subsets independently of the status of membrane structures and receptors frequently altered in colostral cells. The fact that a sizeable number of colostral lymphocytes had the same phenotype as the majority of mature circulating peripheral blood lymphocytes supports the hypothesis that colostral lymphocytes may play a role in protecting neonates against infections, in transferring immune information to the newborn, or in modulating the immune response via release of soluble factors. A considerable percentage of colostral T lymphocytes are ANAE-negative. This phenotype is similar to that observed among thymocytes.
Diabetes in Pregnancy: Growth of the Fetal Pancreatic B Cells in the Rat
Authors: Eriksson Ulf , Swenne Ingemar
Published: September 2009

The development of the pancreatic B cells in the offspring of normal (N), subdiabetic (SD), manifest diabetic (MD) and insulin-treated diabetic (MDI) rats was studied with the aid of immunocytochemical staining for insulin. Morphometric evaluation of the B-cell volume density and weight was made by point sampling. The offspring were studied on gestational days 20 and 22 and in the newborn state. In the N offspring the weight of the B-cell parenchyma doubled during the last 2 days of gestation. This rapid increase may be ascribed not only to high mitotic activity but also to differentiation of putative percursor cells to B cells. The mild glucose intolerance of the SD mothers had no major effects on the fetal B-cell development. In the MD group both the volume density and the weight of the B cells were considerably lower than in the N and SD groups at all ages studied. Despite prolonged gestation, the weight of the fetal B cells in the MD newborns was not greater than that in the 20-day-old fetuses of the N group. Insulin treatment of the MD mothers restored the fetal B-cell development towards normal. This study indicates that manifest maternal diabetes in the rat retards the development of the fetal B cells. This is in obvious contrast to the corresponding situation in human diabetic pregnancy, in which hyperinsulinism represents a striking feature of diabetic fetopathy. It is suggested that a milder form of maternal glucose intolerance together with the relatively longer gestational period in man, compared with the rat, may create conditions that favour fetal B-cell hyperplasia.
Action of Salbutamol on Carbohydrate Metabolism in the Rat Fetus
Authors: Hauguel S. , Gilbert M. , Cedard L.
Published: September 2009

The metabolic action of salbutamol in fetuses was studied after acute (day 21 of pregnancy) and chronic (5 daily infusions from day 16 to day 20 of pregnancy) treatment of pregnant rats. A single injection of salbutamol on day 21 of gestation induced an increase in plasma insulin levels prior to the rise of blood glucose concentration. After the chronic treatment, fetuses from treated mothers showed a decrease in insulin-secreting ability in response to a maternal glucose injection. However, no modifications in fetal liver and placental glycogen contents or in birth weight could be demonstrated. These results suggest that a chronic treatment of pregnant rats with salbutamol could affect the fetal pancreatic responsiveness to glucose.