bluuebunny/crossref_metadata_2025 huggingface dataset:
Intestinal and Femoral Blood Flow Autoregulation in Developing Swine
Authors: Buckley N.M. , Brazeau P. , Frasier I.D.
Published: September 2009

Pressure-flow relationships (P/F) in the small intestine or hindlimb circulation were used to examine autoregulation in 104 swine, aged 1 day to 2 months and anesthetized with pentobarbital. The P/F were obtained while perfusion pressure was decreased by compression of the abdominal aorta for 2 min at each pressure. Readjustments in vascular resistance stabilized within 2 min. Intestinal flow decreased with each decrease in pressure in swine 2 weeks old or younger, but was well maintained by 1 month of age. Femoral flow decreased with each decrease in pressure at all ages studied. Control experiments indicated that the observed vascular responses were independent of angiotension-II activity and were not reflex in origin.
The Effects of Glycolipids and Carbohydrates on Bilirubin Cytotoxicity in vitro
Authors: Sugita Katsuo , Sato Takeyuki , Fuse Akira , Nakajima Hironori
Published: September 2009

We have studied the inhibitory effects of various glycolipids including gangliosides and carbohydrates on bilirubin cytotoxicity towards human glia cells using a 51Cr release assay. All cytotoxic activity was abolished when 100 μM bilirubin was incubated with 40–80 μM gangliosides (GM1 galactosyl-N-acetylgalactosaminyl-(N-acetylneuraminyl)galactosylglucosylceramide; GM2, N-acetylgalactosaminyl-(N-acetylneuraminyl)galactosylglucosylceramide; GM3, N-acetylneuraminylgalactosylglucosylceramide, and GD1 a, N-acetylneuraminylgalactosyl-N-acetylgalactosaminyl -(N-acetylneuraminyl)galactosylglucosylceramide). On the other hand, inhibition by asialoglycolipids was less effective than that by gangliosides, but became more effective with increasing numbers of sugars per molecule, the efficacy of inhibition being as follows: globoside > trihexosyl ceramide > lactosyl ceramide > glucosyl ceramide. Glucosyl ceramide and the carbohydrates of neuramine lactose or N-acetylneuraminic acid (NANA) did not have inhibitory effects. These results suggest that the terminal acidic group of NANA and the numbers of sugar chains in glycolipids play important roles in the inhibition of bilirubin cytotoxicity.
Neuroleptic Drug-Induced Alterations on Neonatal Growth and Development
Authors: Ching Melvin , Tang Loretta
Published: September 2009

Subcutaneousinjectionofcodeineorphenobarbitaland feedingamphetamineto rats during gestation and lactation caused irregularities in mortality rates, growth, development, and associated neuroendocrine events within the newborns. Most striking was the subnormal birth size, increased mortality rate, and decreased hypothalamic growth hormone-releasing activity of neonates of mothers fed the highest dose of amphetamine.
5′-Nucleotidase Activity in Adult and Fetal Rabbit Lungs
Authors: Tsao Francis H.C.
Published: September 2009

5′-Nucleotidase was assayed in the membrane fractions isolated from rabbit lung homogenate. The enzyme activity was measured from the rate of hydrolysis of [U-14C]cytidine 5′-monophosphate (CMP). The optimal pH of the rate of hydrolysis is around 8.0 and the enzyme activity is stimulated by Mg2+. The apparent Km and Vmax of the enzyme in the microsomal fraction for CMP were 3.33 mM and 1.43 μmol/min/mg protein, respectively. During lung development the enzyme activity increased moderately at late gestational ages and reached its maximum level in adults (p < 0.001). The developing profile of 5′-nucleotidase activity is similar to the developing pattern of the CMP content in rabbit lungs.
Isolated Pancreatic Acini from Suckling and Weanling Rats: Changes in Amino Acid Incorporation and Carbachol-Stimulated Amylase Secretion with Age
Authors: Pollack Paul F. , Verbridge Jill , Thornburg William , Koldovsky Otakar , Korc Murray
Published: September 2009

To characterize the changes in pancreatic function during postnatal development, isolated pancreatic acini were prepared from rats aged 8–9, 12–14 and 20 days and from adult rats. Isolated acini maintained a normal microscopic appearance and viability as judged by exclusion of trypan blue and linear incorporation of tritiated leucine into total protein. The rate of incorporation in 8-day-old acini was 20% of that observed in adult rats. Significant dose-dependent increases in amylase release in response to carbachol were observed in all age groups; stimulated amylase secretion was significantly less in the 8- to 9- and 12- to 14-day-old animals than in the 20-day-old and adult rats. These data indicate that viable isolated pancreatic acini can be prepared from suckling rats and that these acini exhibit an altered in vitro responsiveness to carbachol. This preparation should therefore be a useful model for in vitro studies of the development of pancreatic function.
Isoenzymic Analysis of Fifteen Non-Lysosomal Enzymes in Human Chorionic Villi
Authors: Novelli G. , Catizone F. , Dallapiccola B.
Published: September 2009

The electrophoretic pattern of 15 non-lysosomal enzymes was established in human chorionic villi sampled at 8–12 weeks of gestation from 30 women requesting legal abortion. The product of 23 genes was detected at this stage of development. Trophoblast cells are mitotic derivates from the zygote. Thus, chorionic villi have the same genetic constitution as the embryo. Establishing the normal isoenzymatic patterns in fetal life is of wide theoretical and biological interest. In particular, it contributes to the understanding of gene modulation and the differential activity of alleloenzymes during early embryogenesis and development. In addition, the possibility is suggested that in the future electrophoresis analysis can be used in conjunction with quantitative enzyme assay for the fetal diagnosis of specific metabolic disorders involving one or more isoenzymes.
Kidney Growth and Collagen Content in Rat Pups from Uninephrectomized Mothers
Authors: McBroom M.J. , Al-Zaid N.S. , Dlouha H.
Published: September 2009

The effect of uninephrectomy (UNX) or sham-operation (SO) in pregnant rats at the 5th-7th day of gestation upon pup kidney development was studied. In newborns, kidney wet weight was low in pups of the SO and UNX groups, kidney/body weight was low in UNX only; collagen was highest in UNX. At 6 weeks, wet weight was least in UNX; dry weight was low and %H2O high in SO and UNX; collagen/dry weight was high in SO and UNX. Maternal surgery (SO or UNX) appears to impose a non specific development deficit upon pups, although kidney collagen growth is sustained; no specific renotropic activity was evident in pups of the UNX groups.
Fetal Encephalopathies of Circulatory Origin
Authors: Larroche Jeanne-Claudie
Published: September 2009

Fetal brain damage may be due to a variety of pathological conditions resulting in circulatory impairments. With generalized ultrasonography of the fetus, the lesions can be detected in utero and subsequent neurological handicaps of the infants will no longer be attributed to difficult labor and birth. The type of the lesions may be anoxic-ischemic and/or hemorrhagic. The morphological appearance depends on the time of occurrence of the insult in utero and on the time elapsed between the insult and the examination of the brain. Although the pathogenesis of the lesions is not fully understood, they may be related either to maternal, fetal, or placental pathological situations. In a last group of cases no causes as yet have been found.
Microwave Radiation Enhances Teratogenic Effect of Cytosine Arabinoside in Mice
Authors: Marcickiewicz Janusz , Chazan Bogdan , Niemiec Tomasz , Sokolska Grażyna , Troszyński Michał , Łuczak Mirosław , Szmigielski Stanisław
Published: September 2009

Impregnated Swiss mice were irradiated 2 h daily on days 1–18 of gestation in nonthermal (1 or 10 mW/cm2) or thermogenic (40 mW/cm2) 2,450-MHz microwave (MW) fields. On the 19th day of pregnancy all dams were killed to check the number of resorptions. Living fetuses were isolated, weighed and checked for the presence of macroscopically visible malformations of skeleton and cleft palate (CP) and/or lip (CLP). Some of the pregnant mice in each group were injected intraperitoneally on the 9th day of gestation with 10 mg/kg of cytosine arabinoside (ara-C), a well-known teratogen resulting under the above conditions in the appearance of about 15% (42 of 354) of resorbed implantation points and the development of CP or CLP in about 30% (96 of 312) of fetuses. Exposure to nonthermal MW fields during pregnancy did not lead to resorptions or detectable malformations; however, the body mass of 19-day fetuses was significantly lower than in sham-irradiated controls. MW hyperthermia (40 mW/cm2) applied during pregnancy led to an increased number of resorptions -about 25% (37 of 157) compared to 2% (6 of 306) in controls. Significant enhancement of the teratogenic potency of ara-C was observed after combined exposure to both ara-C and MWs during pregnancy. In dams treated with ara-C alone about 20% (62 of 358) resorptions and about 30% (91 of 296) fetuses with CL or CLP were found; additional exposure in MW fields (10 mW/cm2), not resulting per se in resorptions or detectable malformations, increased the numbers to 45% (213 of 448) of resorptions and to 70% (167 of 235) fetuses with CL or CLP. In view of results obtained, we conclude that the relatively weak embryotoxic effects of MWs may be revealed and markedly enhanced after combination of radiation with other teratogenic factors.
Gluconeogenesis from Lactate in the Chronically Catheterized Baboon Fetus
Authors: Levitsky Lynne L. , Paton John B. , Fisher David E.
Published: September 2009

Gluconeogenesis from lactate may be qualitatively identified in the chronically catheterized baboon fetus in the maternal fed and fasted state. Infusion of 250 μCi U-14C-lactate to the fetus over a 150-min period leads to the appearance of 14C-glucose in the fetal circulation. Little 14C-lactate or glucose appears in the maternal circulation, supporting fetal production of glucose from lactate. Maternal glucose infusion seems to inhibit fetal gluconeogenesis. The mean plateau in percent disintegrations per minute of glucose compared to lactate in the maternal fed state is 14.7 ± 2.2 compared to 16.1 ± 3.0 in the maternal fasting state and 11.1 ± 0.6 during maternal glucose infusion. It is clear that the primate fetus is capable of gluconeogenesis before term. Quantitation of this capacity awaits development of a model permitting assessment of maternal-placental and fetal substrate flux.
Colonisation of Haemophilus influenzae and Streptococcus pneumoniae in the Upper Respiratory Tract of Neonates in Papua New Guinea: Primary Acquisition, Duration of Carriage, and Relationship to Carriage in Mothers
Authors: Gratten Mike , Gratten Helen , Poli Alwyn , Carrad Emmanuelle , Raymer Marilyn , Koki George
Published: September 2009

In order to determine the age of acquisition and duration of carriage of the first strains of Haemophilus influenzae and Streptococcus pneumoniae in the upper respiratory tract of Papua New Guinea children, 25 babies were recruited at, or shortly after birth. Nasal secretions from mothers and children were cultured at 1- to 2-weekly intervals. H. influenzae and S. pneumoniae were acquired within the neonatal period by 60% of the infants, and all were colonised by both organisms within the first 3 months of life. Carriage periods for H. influenzae ranged from 6 to 221 days (mean, 74 days), and for S. pneumoniae from 5 to 290 days (mean, 96 days). Penicillin resistance was detected in 36% of the first acquired strains of pneumococci. Mothers, generally either did not carry H. influenzae or S. pneumoniae, or harboured types different to those first acquired by their infants. However, one-third of mothers subsequently became colonised with H. influenzae and S. pneumoniae types similar to those carried by their babies.
Effect of Application Pressure and Gestational Age on Transfontanel Pressure in Healthy Neonates
Authors: Lacey Lora , John Elizabeth , McDevitt Mike , Cassady George , Philips, III. Joseph
Published: September 2009

We developed and evaluated a transducer holder and calibrated, spring-loaded applicator for the Ladd intracranial pressure monitor. The transducer holder/applicator combination allows reproducibility of application pressure and assures coplanarity of the transducer and the skin of the anterior fontanel. Measured transfontanel pressure (TFP) increased with increasing application pressure. Mean TFP was 9.1 ± (SD) 2.6 cm H2O with an application pressure of about 10 g/cm2 in a group of healthy preterm and term infants at 6 h postnatal age. Birth weight, gestational age and mode of delivery did not affect TFP, allowing use of a single normative value and set of confidence limits in all infants at 6 h of postnatal age.
Are Polygraphic and Cardiopneumographic Respiratory Patterns Useful Tools for Predicting the Risk for Sudden Infant Death Syndrome?
Authors: Monod Nicole , Plouin Perrine , Sternberg Bernadette , Peirano Patricio , Pajot Nicole , Flores Robert , Linnett Susan , Kastler Bernadette , Scavone Cristina , Guidasci Simone
Published: September 2009

Between 1974 and 1984 we have studied 204 control infants (C) comparing them with 650 SIDS siblings (SS) and 146 near-miss for SIDS (NM). These 1,000 full-term infants were recorded by day polysomnography (DPSG; n = 417), night polysomnography (NPSG; n = 257) and cardiopneumography (CPG; n = 2,600). Records were visually analyzed. In DPSG and NPSG, total amount of central, mixed and obstructive apnea as well as the percentage of periodic breathing was studied in each sleep state (active sleep, AS; quiet sleep, QS; indeterminate sleep, IS, and total sleep, TS) and over the total recording time (TRT). In CPG, only the total amount of central apnea and percentage of periodic breathing over TRT were studied. Infants were grouped according to postnatal age: < 5, ≥ 5 to ≤ 13, and > 13 to ≤ 26 weeks. In each age group results were compared as follows: C vs. SS, C vs. NM, and SS vs. NM for each parameter studied. Before 5 weeks and after 13 weeks there was no significant difference between C and SS, C and NM, and SS and NM in DPSG and NPSG for all categories of central, mixed and obstructive apnea as well as the percentage of periodic breathing in different sleep states and over TRT. Similar results were obtained in CPG for all categories of central apnea and percentage of periodic breathing over TRT. Between 5 and 13 weeks, results were comparable with those given above, except for central apnea between 2 and 5 s in DPSG, being more numerous in both NM and SS compared with C in AS (p < 0.001 and < 0.01, respectively), and in TS (p < 0.01 and < 0.001, respectively). 146 NM infants were compared according to whether they subsequently had no NM event (n = 117) or one or more NM events (n = 29). No difference was found between these 2 groups (in DPSG, NPSG and CPG) which could allow the risk of a subsequent NM event to be predicted. The same study was done in SS: five of them subsequently had one or more NM events. No significant differences were found between SS with or without an NM event. Four SS died unexpectedly (3 diagnosed as SIDS at autopsy) with no significant abnormalities on their recordings. In any case, according to our results DPSG, NPSG and CPG recordings do not permit the risk for SIDS in any infant to be predicted.
Ontogeny of Fatty Acid-Activating Enzyme in Rat Liver and Lung
Authors: Riaz-ul-Haq R.
Published: September 2009

Fatty acyl CoA synthetase (FACS) activities were investigated in fetal, neonatal and adult liver and lung. Lung microsomal FACS activity increased near term, declined after birth and reached adult values in 30-day-old rats. Liver microsomal FACS did not show these changes near term. The post-weaning shift from a high fat diet to regular chow diet resulted in decreased liver FACS activity. Lung FACS did not respond to this change in diet. These data demonstrate that long chain FACS is present in the last 4 days of fetal life and probably contributes to the activation of fatty acids utilized as energy substrate or for the synthesis of phospholipids.
Inositol Phosphatase in Developing Rat Duodenum, Jejunum and Ileum
Authors: Rao R.K. , Ramakrishnan C.V.
Published: September 2009

Inositol phosphatase and phytase activities in different segments of the rat small intestine were measured during postnatal development. In the duodenum and jejunum, inositol phosphatase activity (units/g tissue) was low during the suckling period and increased at weaning, reaching a peak of activity at 4 weeks of age. In the ileum, peak activity was observed during the suckling period with a sharp decline at weaning. Phytase activity was very low during the suckling period in all segments, and increased to exhibit a peak at 4 weeks of age in the duodenum, and to a lesser extent in the jejunum (low activity was maintained in the ileum). The content of inositol phosphatase activity in the duodenum increased rapidly during the suckling period to reach its maximum at 4 weeks of age. This suggests a relationship to cell proliferation rate in the small intestinal mucosa.
Caliper Skinfold Measurements in Newborns: Analysis of a Method
Authors: Weile Birgitte , Bach-Mortensen Niels , Peitersen Birgit
Published: September 2009

Bilateral skinfold measurements on 10 different sites were performed blindly by 3 investigators in 118 newborns with a mean birth weight from 1,700 to 4,200 g. The caliper method was precise as judged by intra- and interobserver variances. Precision was independent of skinfold thickness, and not related to amount of training. Bilateral measurements of skinfolds over the quadriceps, pectoral and biceps muscles carried the highest precision. Precision was significantly increased by combination of these 3 measurements. There was no significant difference between the precision of these 3 bilateral measurements and 5 selected unilateral sites. For clinical practice, we recommend cumulated measurements of right-sided skinfolds over the quadriceps, pectoral, biceps and triceps muscles and subscapular skinfold.
Lipid Synthesis in Various Organs of the Rat during Postnatal Development
Authors: Hahn P.
Published: September 2009

The incorporation of 3H2O into the lipids of brown and white adipose tissue (BAT and WAT), skin, liver, heart, kidney, brain and lungs was studied 1 h after injection in rats aged 1,13 and 22 days. In the younger age group, triglyceride synthesis was considerably higher in BAT than in any other tissue, while in the 22-day-old rats, this is no longer the case. Cholesterol synthesis in the oldest age group was highest in liver. In the younger animals, there was little difference between tissues in the low rate of cholesterol synthesis except in the brain where the rates of all lipid syntheses were highest on day 13. The surprisingly high rate of triglyceride synthesis in BAT of infant rats is partly due to the high rate of synthesis of the glycerol moiety. Nevertheless, on hydrolysis, the rate of fatty acid synthesis was still highest in these animals.
Constriction of the Fetal Ductus arteriosus by Progesterone
Authors: Pulkkinen M.O. , Momma K. , Pulkkinen J.
Published: September 2009

Progesterone substitution in the rat during pregnancy days 17–21 or administration 6 h before spontaneous delivery constricted the fetal ductus arteriosus. The rapid whole-body freezing technique was used. Indomethacin-induced constriction of the fetal ductus arteriosus was not affected by progesterone treatment.
Fetal Cardiovascular and Breathing Movement Responses to Endogenous Opiates
Authors: Lewis Alan B. , Ferry David A. , Sadeghi Mahvash
Published: September 2009

Endogenous opiates have been shown to alter cardiopulmonary activity in a variety of animal models. The present investigation in fetal sheep evaluated the response of heart rate, blood pressure and breathing movements (FBM) to central nervous and intravenous meth-enkephalin and β-endorphin. Marked bradycardia was noted within 3–5 s of intravenous meth-enkephalin administration and lasted less than 10–15 s. An 84.8 ± 19.0% prolongation in cardiac cycle length was observed after 20 nmol/kg meth-enkephalin (p < 0.02). In contrast, there was no significant change in heart rate following 2–50 nmol/kg β-endorphin. The meth-enkephalin-induced slowing of heart rate was virtually eliminated by autonomic blockade with atropine or hexamethonium but merely partially blunted by naloxone. FBM were not altered by intravenous administration of either opiate. However, both meth-enkephalin and β-endorphin produced a dramatic increase in FBM following injection into the cisterna magna. Prior to opioid administration, FBM were noted 11 ± 1.4% of the time. Intracisternal opiates resulted in a 43.9 ± 10.1% incidence of FBM for up to 60 min. Parasympathetic blockade with atropine had no effect on the pattern of FBM following intracisternal opiate administration whereas naloxone terminated the increased respiratory activity within 1 min. These data suggest a potential role for endogenous opiates in the modulation of fetal cardiorespiratory function.
Postnatal Distribution of Vitamin A in Liver, Lung, Heart and Brain of the Rat in Relation to Maternal Vitamin A Status
Authors: Sharma Hari S. , Misra U.K.
Published: September 2009

The effect of low, medium and adequate vitamin A (6, 40 and 100 μg/day/kg body weight) supplementation to the dams was studied on the accumulation of vitamin A in various tissues of the rat during postnatal growth. The restricted supply of vitamin A to the mother resulted in an impaired growth of pups and their organs. The maternal hepatic stores of vitamin A were related to their vitamin A intake, being lowest in the low group and highest in the adequate group during their fetal development. The plasma vitamin A levels of dams were comparable in three groups at birth and on 10th day of postnatal age. The vitamin A contents of fetal hepatic and extra-hepatic tissues (lung, heart and brain) were increased with the age of pups and this increase was observed to be dependent on the supply of vitamin A to the mother.
Effect of Metoclopramide Therapy on Arginine Vasopressin Excretion and Renal Water Handling in Premature Infants
Authors: Sulyok E. , Kovács L. , Lichardus B. , Bircak J.
Published: September 2009

The role of endogenous dopamine (DA) in regulating arginine vasopressin (AVP) release and renal water excretion was studied in 10 premature infants with a mean birth weight of 1,341 g (range 1,150–1,660 g) and a mean gestational age of 30.2 weeks (28–33 weeks), who were given metoclopramide (MTC), a specific DA antagonist. It was demonstrated that in response to MTC urine flow rate increased significantly from a basal value of 0.90 ± 0.07 to 1.27 ± 0.09 ml/min/1.73 m2 (mean ± SE; p < 0.01), urinary sodium excretion from 6.10 ± 1.47 to 11.7 ± 2.24 μEq/min/1.73 m2 (p < 0.025) and osmolar clearance from 0.38 ± 0.044 to 0.600 ± 0.075 ml/min/1.73 m2 (p < 0.01). MTC administration did not cause any alterations in free water clearance, whereas urinary AVP excretion fell significantly from 49.38 ± 10.13 to 32.66 ± 6.53 ng/min/1.73 m2 (p < 0.05) after MTC. It is concluded that, contrary to adults, in low birth weight premature infants endogenous DA is enhancing rather than inhibiting AVP release and the MTC-induced water diuresis is independent of the fall of AVP since free water clearance remained unaltered after MTC.
Tin Protoporphyrin Inhibits Carbon Monoxide Production in Suckling Mice
Authors: Stevenson David K. , Watson Elizabeth M. , Hintz Susan R. , Kim Charles B. , Vreman Hendrik J.
Published: September 2009

The carbon monoxide excretion rate (VeCO) of groups of 1-day-old mice was measured after administration of two separate doses of 50 nmol of tin protoporphyrin (TP) per gram of body weight. The mean VeCO of the saline-treated control groups over the study period was 1.50 ± 0.26 nmol/g/h, and that of the TP-treated groups was 1.35 ± 0.29 nmol/g/h. Tin protoporphyrin treatment reduced the CO excretion by approximately 14% in 2-day-old mice over 24–48 h.
Maternal Factors Modulating Nutrient Transfer to Fetus
Authors: Lasunción M.A. , Lorenzo J. , Palacin M. , Herrera E.
Published: September 2009

Current knowledge of the modulation of maternal-fetal transfer of metabolites is reviewed and new data on the actual placental transport of D-glucose, L-alanine and glycerol in the rat are presented. Twenty-one day pregnant rats were infused with the 14C-labelled substrates throughout the left uterine artery. Radioactivity appearing in fetuses was corrected by the specific dilution of the tracer at maternal arterial plasma and the uterine artery blood flow to estimate placental transfer. This parameter appeared to be 127 μmol·kg––1 fetal b.w.·min––1 for D-glucose, 23 for L-alanine, and 1 for glycerol – values which are much higher than those described for larger species. There is a parallelism between the magnitude of transfer to fetus and arterial concentration in mother for each studied metabolite and actually variations in their plasmatic levels affect this transport process. This is clearly seen in the case of glucose where placental transfer is reduced during fasting hypoglycemia and greatly increased in diabetes. Placental transfer of L-alanine and blood flow to the placenta were reduced in both 48-hour starved and streptozotocin-induced diabetic late pregnant rats. Results show the main role of maternal nutrient concentration as a modulator of their transfer to fetus, the deleterious effect of reductions of uterine blood flow on placental transport of amino acids as well as the small placental transfer of glycerol as compared to either glucose or alanine.
Research Priorities in Diabetic Pregnancy Today: The Role of Animal Models
Authors: Baird J.D. , Aerts L.
Published: September 2009

Strict metabolic control has resulted in a striking fall in the rates for stillbirths, neonatal deaths and neonatal morbidity in diabetic pregnancy. However, clinical problems and challenges for research remain, particularly in relation to a high incidence of congenital malformation, low birth weight, and early growth delay; the detection and management of gestational diabetes; insulin delivery systems; the consequences of maternal hypoglycaemia on organogenesis and fetal well-being; the mechanisms underlying various categories of neonatal morbidity, and possible long-term morbidity in the children born to diabetic mothers. The nature of these problems determines that certain fundamental aspects of reproduction which are difficult to study in human pregnancy will have high priority for research. Progress in this field will be heavily dependent on animal models in the foreseeable future.
Effects of Oral L-Carnitine Supplementation in Low-Birth-Weight Premature Infants Maintained on Human Milk
Authors: Melegh Béla , Kerner János , Sándor Attila , Vincellér Maria , Kispál Gyula
Published: September 2009

Effects of oral L-carnitine supplementation on fat and protein metabolism have been studied in 20 low-birth-weight premature infants (mean weight at birth 1.519 g, range 1,200–1,880 g) fed with pooled pasteurized human milk. Throughout 7 consecutive days, started at various postnatal ages (range 10–33 days) infants were fed exclusively with milk containing 300 nmol/ml L-carnitine as added supplement. The amount of extra carnitine intake ranged from 42.6 to 72.0 μmol/kg/day. Until day 5 of supplementation there was a continuous increase in the daily urinary excretion of total carnitine, which levelled off thereafter, corresponding approximately to 50% of the extra L-carnitine intake, indicating that a part of the supplement was retained by the body. Total, free and esterified carnitine levels were significantly elevated in the plasma at the end of the study period. The increased levels of acylcarnitines in plasma and urine indicate that the carnitine supplement was taken up by tissues and entered the intermediary metabolism. Plasma triglyceride level was decreased, whereas 3-hydroxybutyrate level was increased at the end of supplementation, indicating an enhanced fat utilization. Plasma and urine analysis also revealed an altered nitrogen handling. There was a marked decrease in plasma urea level as well as a significant fall in the urea and total N excretion, with a trend of decrease in excretion of 3-methylhistidine, suggesting a reduced amino acid and protein catabolism during L-carnitine supplementation.
Hemodynamic and Ventilatory Effects of High-Frequency Jet and Conventional Ventilation in Piglets with Lung Lavage
Authors: Suguihara Cleide , Bancalari Eduardo , Goldberg Ronald N. , Barrios Patricia , Hehre Dorothy
Published: September 2009

The cardiovascular and ventilatory effects of high-frequency jet ventilation (HFJV) and conventional ventilation (CV) were evaluated in a saline lung lavage model in piglets. After saline lavage and stabilization on CV, animals were randomized to either mode of ventilation for 4 h. Arterial blood gases, cardiac output, mean pulmonary and arterial blood pressures, and pulmonary and systemic vascular resistances were compared between groups. Alveolar-arterial oxygen gradient (AaDO2) was lower in the HFJV than in the CV group after 3 h of ventilation (p < 0.04). The peak inspiratory pressure necessary to maintain PaCO2 within the normal range was approximately half as much in the HFJV group as in the CV group (p < 0.005) throughout the entire study period. Mean airway pressure, cardiac output, mean pulmonary and arterial blood pressures as well as pulmonary and systemic vascular resistances were not statistically different between groups. These results suggest that in this model, HFJV produces better oxygenation with lower peak airway pressures compared to CV without producing hemodynamic compromise.
Vasopressin Functions as an Endogenous Antipyretic in the Newborn
Authors: Kasting Norman W. , Wilkinson Marshall F.
Published: September 2009

These experiments sought to determine the role of arginine vasopressin (AVP) in the inability of newborns to produce a fever. Our data demonstrate that the AVP analog, [1-β-mercapto-β,β-cyclopentamethylene propionic acid)-2-(O-methyl)tyrosine] arginine vasopressin (M-AVP), administered centrally to adult rats, prevented the antipyretic action of centrally injected AVP. Behaviorally thermoregulating 3-day-old rat pups failed to respond to endoxin with a fever, similar to neonates of other species, but when central AVP antipyretic receptors were blocked by pretreatment with M-AVP, the pups were able to raise their body temperature to febrile levels. The antipyretic drug, indomethacin, prevented these fevers. We conclude that endogenous AVP is a physiologically important antipyretic substance in the brain of the newborn rat.
Effects of Parenteral and Enteral Nutrition on Postnatal Development of the Small Intestine and Pancreas in the Rabbit
Authors: Gall D.G. , Chung M. , O’Loughlin E.V. , Zahavi I. , Opleta K.
Published: September 2009

Although TPN is used frequently in young infants, little information is available regarding its effect on postnatal development of the gut. The effect of total parenteral nutrition (TPN) and intragastric (IG) alimentation on ontogeny of the small intestine was examined in infant rabbits starting at 10–12 days. Animals were killed at 17–19 days. Body weight, organ weight and weight of segments of proximal, mid and distal small intestine were measured. Intestinal mucosa was scraped, weighed and homogenized for estimation of protein, DNA and disaccharidases. Na+ transport was examined in short-circuited jejunum. Weight gain was similar in controls, sham-treated and TPN animals, but was significantly reduced in IG animals. TPN induced precocious development of sucrase and maltase activity and glucose-stimulated Na+ transport, despite causing a significant decrease in mucosal weight and DNA and pancreatic amylase. IG alimentation also induced precocious development of sucrase, maltase and glucose-stimulated Na+ transport. Thus TPN, despite producing mucosal atrophy and decreased pancreatic exocrine development, stimulates accelerated postnatal maturation of the small intestine.
A Prospective Study on the Intrauterine Growth of Hong Kong Chinese Babies
Authors: Fok T.F. , Lam T.K. , Lee N. , Chow C.B. , Au Yeung H.C.L. , Leung N.K. , Davies D.P.
Published: September 2009

A prospective study on the birth weight, crown-heel length and head circumference of 8,445 singleton Chinese newborn infants born between 27 and 42 weeks of gestation was conducted in three major regional maternity units in Hong Kong over a 3½-year period. The data were used to construct centile charts for the intrauterine growth of each physical measurement. By careful gestational assessment of the infants, primary exclusion of pregnancies complicated by abnormal fetal or maternal conditions that might have affected fetal growth together with infants of doubtful maturity, these curves depict more accurately the prenatal growth of Chinese infants than those previously published in studies on similar populations of infants. Chinese infants, as shown by the findings of the present study, are similar in their mean weight to Japanese infants and American infants in Denver but are lighter than British and Australian infants, as well as American infants born at sea level.
Effects of pH and Hypoglycemia on Bilirubin Cytotoxicity in vitro
Authors: Sugita Katsuo , Sato Takeyuki , Nakajima Hironori
Published: September 2009

In this study the effects of pH and hypoglycemia on bilirubin cytotoxicity in vitro were examined by means of a 51Cr release assay. The bilirubin cytotoxicity, which was dose dependent, was increased at lower pH values. Cells, pre exposed to the hypoglycemic state, became more resistant on incubation in culture medium containing glucose for 1 h in comparison with those exposed to the hypoglycemic state only.
Developmental Expression and Modification of Genes
Authors: Benvenisty Nissim , Reshef Lea
Published: September 2009

Differentiating tissue is characterized by a specific repertoire of proteins out of which some are developmentally controlled. This review describes modifications in the structure of genes which encode developmentally regulated proteins. Evidence is provided for changes in chromatin conformation and DNA methylation of specific genes – either change can be observed in various stages of some vertebrates. The involvement of hormones in regulating DNA modifications is suggested, and interrelationships between DNA modifications and gene expression are discussed.
Carnitine Concentrations in the Milk of Different Species and Infant Formulas
Authors: Penn Duna , Dolderer Maria , Schmidt-Sommerfeld Eberhard
Published: September 2009

Carnitine concentrations were measured in the milk of sheep, cows, goats, and horses, in human milk of term and preterm infants and in European infant formulas. There were significant species’ differences in carnitine milk content. Acylcarnitme concentrations ranged from 13 to 47% of total carnitine. This may be related to differences in maternal and/or mammary gland metabolism. The concentration of long-chain acylcarnitine in milk was under 1 % in all investigated species. In cow’s milk, there was a decrease in acylcarnitine concentration during the first 2 months of lactation. In human milk, carnitine concentrations did not change during the 1 st month postpartum, but maternal plasma carnitine concentrations increased and plasma concentrations of acylcarnitine were always lower than those in simultaneously sampled milk. Milk carnitine concentrations in mothers of premature infants were not different from those in mothers of term infants. European formulas based on cow’s milk contained somewhat more carnitine than human milk. However, very low carnitine concentrations were found in soy-based or protein hydrolysate formulas. This may lead to nutritional carnitine deficiency in infants receiving these formulas without carnitine supplementation.
Effect of Protein Malnutrition and Maternal Caffeine Intake on the Growth of Fetal Rat Brain
Authors: Yazdani Malektaj , Tran Tai H. , Conley Pamela M. , Laurent, Jr Julius , Nakamoto Tetsuo
Published: September 2009

Pregnant dams were divided into two subgroups on day 10 of gestation. Half were fed a 20% protein diet and the other half an 8% protein diet. A second group also subdivided was pair-fed with rats of the first group. Their diet was supplemented with caffeine in amount calculated to provide daily doses of 2 mg/l00 g body weight. On days 18, 20, and 22 randomly selected dams were injected with 3H-thymidine intraperitoneally and 1.5 h later their fetuses were delivered surgically in order to determine the rate of DNA synthesis along the gestation. The rest of the fetuses were delivered surgically on day 22. Pups’ brains were rapidly removed and DNA, RNA, protein and 3H-thymidine uptake were studied. Average body weights of the fetuses in the caffeine-supplemented control group were smaller than those of the noncaffeine group. Effects of caffeine that were similar in both diet groups included a decrease in brain DNA content and concentration and an increase in brain protein content and concentration. However, the percent decrease and increase, respectively, was different depending on the nutritional status. DNA synthesis was not affected by malnutrition or caffeine supplementation on day 18 of gestation. Caffeine’s effect on the rate of DNA synthesis was different on day 20 of gestation depending on nutritional status. Caffeine supplementation resulted in a decrease in DNA synthesis in both groups on day 22 of gestation. These data indicate that caffeine intake during pregnancy produces differential effects on fetal rat brain depending on dietary protein content.
Serum HDL Cholesterol and Apolipoprotein AI, All and B Levels in Singapore Newborns
Authors: Saha N.S. , Wong H.B.
Published: September 2009

The mortality from coronary artery disease (CAD) in Indians is more than three times that in the Chinese and Malays of Singapore. Serum total and HDL cholesterol as well as apolipoprotein (Apo) AI, All and B levels were determined in a group of 349 newborns (cord blood) from both sexes in these three ethnic groups in order to examine if a trend is reflected at birth. Both serum LDL cholesterol and Apo B levels were low in the newborn, while HDL cholesterol and Apo All levels were almost the same as in adults. Serum Apo AI levels were also low in newborns. No consistent difference as to ethnic group or sex was observed in any of the parameters investigated, except that the females had significantly higher levels of serum Apo AI in all the ethnic groups. Serum total and HDL cholesterol levels in Singapore newborns were comparable to those reported in Caucasians and Asians. The trends of incidence of CAD were not reflected in the lipid profiles studied at birth.
Effects of Isoproterenol-Induced Tachycardia on Myocardial Blood Flow and Glycogen in the Fetal Lamb
Authors: Tweed W.A. , Davies J.M. , Alexander F. , Csorba T. , Weber S.
Published: September 2009

In utero tachycardia is a cause of fetal congestive heart failure and fetal hydrops. We investigated the effects of isoproterenol-induced tachycardia (IIT) on cardiac output and its distribution, on myocardial blood flow and intramyocardial blood flow distribution as well as on regional myocardial glycogen in 8 chronically prepared, near-term fetal lambs and 3 control twins (for myocardial glycogen only). Blood flows were measured by the radioactive microsphere method, myocardial glycogen by an enzymatic method. In animals with IIT (heart rate 200–280), cardiac output (excluding lung flow) increased from 0.399 to 0.544 ml/g/tissue/min (+36%), blood flow to the carcass increased from 0.19 to 0.32 ml/g/tissue/min (+68%) and myocardium increased from 2.31 to 7.72 ml/g/tissue/min (+234%), while kidney blood flow decreased from 1.34 to 0.72 ml/g/tissue/min (––46%). The normal intramyocardial blood flow distribution and predominance of flow to the endocardium of both ventricles was preserved during IIT. In the three sets of twins, glycogen was lower in the right (RV) and left (LV) ventricular walls of each animal stressed by IIT (mean RV = 0.19, mean LV = 0.44) than of its unstressed twin (mean RV = 0.75, mean LV = 0.70). Furthermore, a metabolic acidemia (mean pH 7.21, mean BE -8.4) developed in the stressed animals. Although we were unable to demonstrate regional myocardial ischemia at the maximal fetal heart rates achieved by isoproterenol infusion, our data suggest that metabolic acidemia and myocardial glycogen depletion are consequences of severe inotropic and chronotropic stress in the fetal lamb.
The Newborn Rabbit: A Model for Studying Hypoxemia-Induced Renal Changes
Authors: Gouyon Jean-Bernard , Vallotton Marianne , Guignard Jean-Pierre
Published: September 2009

The newborn rabbit was used as an experimental model for studying renal changes during normocapnic hypoxemia. Renal extraction of p-aminohippuric acid (PAH), as assessed in 15 normoxemic and 8 hypoxemic rabbits amounted to 54.6 ± 3.7 and 45.7 ± 4.6%, respectively (NS). Changes in glomerular filtration rate (GFR), and renal blood flow (RBF) as assessed by inulin and PAH clearances, respectively, were determined during norm oxemia and subsequent hypoxemia in 8 additional anesthetized and mechanically ventilated newborn rabbits. Normocapnic hypoxemia (PaO2 = 38.6 ± 2.1 mm Hg) induced a significant fall in GFR from 2.10 ± 0.21 to 1.51 ± 0.18ml/kg/min (p < 0.01), in filtration fraction (p < 0.01) and U/P inulin ratio (p < 0.01). RBF, renal vascular resistance and urine flow rate did not change significantly. In comparison with other immature animal species the newborn rabbit appears a valuable and inexpensive model for the study of acute hypoxemia-induced renal changes.
Kallikrein Excretion: Relationship with Maturation and Renal Function in Human Neonates at Different Gestational Ages
Authors: Vio Carlos P. , Olavarria Fernando , Krause Sergio , Herrmann Fernando , Grob Karin
Published: September 2009

Kallikrein excretion and renal function were studied on 37 one-day-old newborn infants (14 fullterm and 23 preterm infants). Preterm infants excreted less kallikrein (p < 0.001), had lower creatinine clearance (p < 0.02) and urinary osmolality (p < 0.01). They had higher values on urinary volume (p < 0.001), FENa (p < 0.001), FEK (p < 0.02), and free water clearance (p < 0.01) than fullterm infants. The excretion of kallikrein correlated directly with gestational age (p < 0.01) and body weight (p < 0.01). No correlations were found with FENa, urinary volume, FEK or free water clearance. The values of kallikrein excretion were very low when compared with a young adult population. As kallikrein is synthesized in the distal nephron we advance as an hypothesis that the low levels of kallikrein excretion observed in newborns could be a reflection of immature distal tubular mass, and to the relative unresponsiveness of the distal nephron to hormones known to stimulate renal kallikrein such as aldosterone and antidiuretic hormone.
Amino Acid Profiles during Development of the Fetal Rat
Authors: McEvoy-Bowe Edward , Hislop Jaqueline , Wiggins David , Lund Patricia
Published: September 2009

Umbilical blood venous-arterial differences for amino acids across the rat fetus show uptake of disproportionately large amounts of glutamine, alanine and lysine relative to their contribution to total body protein. Free amino acid concentrations in fetal liver tend to increase during development, but show a rapid adjustment to near-adult values within 24 h after birth.
Intestinal Macromolecular Transmission in the Young Rat: Influence of Protease Inhibitors during Development
Authors: Telemo E. , Weström B.R. , Ekström G. , Karlsson B.W.
Published: September 2009

Intestinal macromolecular transmission in young rats of 10, 14, 18, 22 and 30 days of age was measured as the blood serum levels of markers 6 h after oral feeding of a solution containing bovine IgG (BIgG), bovine serum albumin (BSA) and fluorescein-isothiocyanate-labeled dextran 70,000 (FITC-D), either alone (controls) or with soybean trypsin inhibitor (SBTI) or swine colostrum trypsin inhibitor (SCTI). In the 10- and 14-day-old rats, transmission of all three macromolecular markers was high, with a preference for IgG. Transmission was greatly reduced by the age of 18 days and totally arrested for the protein markers at 22 days, with a low transmission of FITC-D remaining at 30 days of age. Addition of either of the two protease inhibitors significantly elevated the transmission of the protein markers in the rats aged 10, 14 and 18 days, while the transmission of the protease-independent marker FITC-D was unaffected. From 14 days of age, the rats have a functioning intestinal proteolysis, since only small amounts of marker proteins were left in the gut lumen 6 h after feeding, and since the addition of protease inhibitors resulted in increased amounts of undegraded proteins intraluminally. The results indicate that the increase of intraluminal proteolytic activity during development and the presence of protease inhibitors in the food are of importance for the intestinal transmission of undegraded proteins in the young rat. The Fc receptor for IgG in the enterocyte is not sufficient to maintain an optimal transmission of IgG, since the intraluminal proteolytic activity also appears to be of importance.
Glucose Homeostasis in the Newborn: Effects of an Intravenous Glucose Infusion in Normal and Intra-Uterine Growth-Retarded Neonatal Piglets
Authors: Flecknell P.A. , Wootton R. , Royston J.P. , John M.
Published: September 2009

Disturbances of glucose homeostasis are a common clinical problem in low birth weight human infants. Previous studies have demonstrated that the intrauterine growth-retarded piglet is a suitable animal model for the study of such problems. The effects of an intravenous glucose infusion on glucose homeostasis have been studied in normal and intrauterine growth-retarded neonatal piglets using a non-steady state tracer technique. Despite suppression of hepatic glucose output, hyperglycaemia (plasma glucose > 10.0 mmol/l) developed in the majority of animals. The hyperglycaemia resulted from a failure to increase glucose utilisation adequately in response to the glucose infusion. Growth-retarded animals had an impaired ability to increase their rate of glucose utilisation, although, in common with the normally grown animals, they demonstrated a graded response to different infusion rates of glucose.
Common Carotid Artery Flow Velocity Measurements in the Newborn Period with Pulsed Doppler Technique
Authors: Raju Tonse N.K. , Go Margaret , Ryva James C. , Schmidt David J.
Published: September 2009

Using a commercial pulsed Doppler (PD) system we measured commoncarotid artery (CCA) flow velocities in 19 healthy and 6 stable preterm infants and computed volume flow rates based on the time-averaged flow velocities and vessel diameter. The mean (± SEM) time-averaged CCA velocities in the term and preterm infants were 33.04 ± 3.0 and 23.3 ± 1.3 cm·s-1 respectively. The total flow volume was significantly higher in the term as opposed to preterm infants: 126 ± 11.2 vs. 55.6 ± 7.7 ml/min (p < 0.01). The body-weight-normalized flow volume, however, was not statistically significantly different between the two groups of infants. Several technical and practical limitations still exist to compute cerebral blood flow (CBF) volume accurately. In a puppy model we measured the CCA flow volume by electromagnetic flowmeter technique, and the PD device simultaneously. The correlation coefficient between 32 pairs of measurements was 0.93 (p < 0.005). We conclude that commercial PD devices provide accurate velocity data, and under experimental conditions, the computed volume flow rates are accurate. Although in clinical situations reasonably accurate CBF values can be estimated, refinements in technology are needed to adopt this method as a possible means of measuring CBF at the bedside.