bluuebunny/crossref_metadata_2025 huggingface dataset:
Variations of the Intraesophageal Pressure with Maturation in the Postnatal Piglet
Authors: Richardson Charles , Miller Arthur J.
Published: September 2009

Variations in intraesophageal pressure (Pes) to 5-min exposures of 100% O2, 10%O2, and 6% CO2 were studied in successive days during the first 2 months of 8 piglets. Pressure measurements were integrated over time to obtain mean pressure changes for each minute. Initial exposure to 100% O2 decreased the mean pressure in all piglets followed by an increase over the next 4 test minutes. 5 of 8 piglets demonstrated maximum increases (25–55% above control) at 5 days and between 15 and 22 days; 3 piglets only at 5 days. Initial exposure to 10% O2 increased the pressure in all piglets followed by a decreased pressure (––10%) in the next 4 min when the piglets were less than 22 days, and an increase (15–70%) when above this age. Exposure to 6% CO2 increased the pressure throughout the 5-min test period with the maximum increase (140–160%) at the earliest ages tested of 5 days.
Transport of Uric Acid and Hypoxanthine Across the Isolated Guinea Pig Placenta
Authors: van Kreel B.K. , van Dijk J.P.
Published: September 2009

Transport of uric acid and hypoxanthine across the isolated guinea pig placenta is investigated quantitatively. The clearances measured are independent of concentration. It is shown that the uric acid transport is not greatly influenced by variations in flow, so it is concluded that the uric acid transport is membrane limited. The clearance of hypoxanthine is even less than the uric acid clearance, so hypoxanthine transport is also membrane limited. Xanthine oxidase is shown to be present in the uterine tissues, and an apparent Km and a maximum velocity have been determined.
Increase of Serum Thyrotropin (TSH) of Suckling Rats after Thyroliberin (TRH) Injection to Lactating Mothers
Authors: Štrbák V. , Macho L.
Published: September 2009

Injection of 50 μg TRH to lactating rats 15 days after parturition was followed 4h after treatment by an increase of serum TSH and a decrease of absolute and relative pituitary TSH content in suckling pups when compared to sucklings of saline-treated mothers. The weight of the pituitary and thyroid also decreased. Results indicate that TRH administered to lactating rats induces release of TSH from the pituitary of suckling pups. An increase of the variability of serum TSH and a decrease of pituitary TSH content at noon in pups of saline-treated mothers suggest the presence of diurnal variation of TSH secretion in 15-day-old rats.
Undersulfated Urinary Glycosaminoglycans in Preterm Newborns
Authors: Coppa Giovanni V. , Gabrielli Orazio , Maiorana Andrea , Sani Stefania , Benincasa Alberto , Belsito Mario , Montali Umberto
Published: September 2009

The glycosaminoglycans (GAG) isolated from pooled urine of preterm newborns were fractionated by step wise elution from a Dowex 1-X2 column. Analytical reactions, cellulose acetate electrophoresis and enzymatic digestions with chondroitinases and testicular hyaluronidase were performed on each fraction. Chondroitin-4-sulfate and chondroitin-6-sulfate constitute about 60% of urinary GAG; heparan sulfate amounts to about 20%, while chondroitin represents 12% of total GAG; dermatan sulfate, hyaluronic acid and keratan sulfate are present in small traces. Approximately 30% of the total is constituted by nonsulfated GAG.
General Observations on the Growth and Development of the Young Pouch Opossum, Didelphis virginiana
Authors: Cutts Harry , Krause William J. , Leeson Roland
Published: September 2009

A 3-year study of general growth and development revealed a uniform increase in body length of young pouch opossums during the first 10 weeks of life. Throughout this period, growth was linear and constant for all animals regardless of sex, litter size, or whether animals were obtained from first, second or third litters. Body weights were somewhat more variable, but there were no significant sex differences. Various aspects of external gross morphology are presented and discussed as they relate to growth of the young opossum.
Quantification of Intrauterine Malnutrition
Authors: Roord J.J. , Ramaekers L.H.J.
Published: September 2009

Small-for-gestational-age infants are a heterogeneous collection of growth-retarded infants. In the subgroup of intrauterine-malnourished infants an attempt is made to quantify the degree of malnutrition by postnatal measurements of length, weight and fat-fold thickness. In 48 clinically wasted and not-wasted term newborns, regardless of birth weight, the ponderal index of Rohrer (100 × W/L3) was determined and the deviation from Ê»normal’ calculated. The deviations are correlated with fat-fold thickness and clinical diagnosis. A highly significant correlation gives support to the view that both ponderal index deviation from Ê»normal’ and fat-fold thickness are useful parameters to quantify the effect of intrauterine malnutrition in newborns.
Development of Glucose-Mediated Insulin Release Response in Organ Cultured Rat Pancreas
Authors: Hasty David L. , Murrell Leonard R.
Published: September 2009

In the Sprague-Dawley rat, glucose concentration dependent insulin release first appears 2 days after birth. If pancreatic explants from 19-, 20- or 21-day fetal rats are organ cultured to a period corresponding to the 4th postnatal day, 120 min stimulus with glucose (100 or 300 mg/dl) fails to produce glucose-dependent insulin release. When explants from 20-day fetal pancreas are cultured, glucose-mediated insulin release develops after 12 h to 2 days of culture, and persists for up to 2 days. Explants from 3 day postnatal pancreas retain glucose-dependent insulin release for at least 2 days culture. High tissue insulin levels and continued release of immunoreactive insulin into culture medium are maintained throughout the culture period studied. Our data show that glucose-mediated insulin release can develop in organ culture, and suggest that this development, after the 19th fetal day, does not require extrapancreatic neural or endocrine factors.
Influence of Prenatal and Continuous Postnatal Protein-Deficient Diets on the Development of Rats
Authors: Wittstruck Thomas A. , Woodward Barbara E. , Forbes William B. , Caspi Eliahu
Published: September 2009

The influence of prenatal and continuous postnatal protein-restricted diet on the development of rats was investigated. Virgin female rats were maintained for 35 days on isocaloric diets containing 8 or 25% casein, and then mated. The animals were supplied their respective diets during gestation and nursing. It was observed that the offspring of mothers kept on the 8% casein diet had 50% less body weight, and 10–15% less brain weight than the corresponding controls. The peak of rapid brain growth for both groups of animals occurred at age 6 days. The rate of de novo biosynthesis of sterols, following the injection of (2-14C)-mevalonic acid into the midline thalamic area and the cerebellum, was also investigated. A significant shift of the age of peaking of 14C-incorporation into sterols in the cerebellum was noted. Our results indicate that although unlimited amounts of food were supplied to the mothers on the 8% casein diet, this could not offset the detrimental effect of the protein deficiency on the offspring.
Minimal Tissue Concentrations of Glutamate Required to Produce Necrosis of Hypothalamic Neurons in Newborn Mice
Authors: Perez V.J. , Olney J.W. , Martin J.F. , Cannon W.O.
Published: September 2009

Groups of 4-day-old Cox Swiss albino mice were injected once subcutaneously with monosodium glutamate at several doses between 0.2 and 0.5 mg/g body weight. Glutamate, at a dose of 0.35 mg/g, produced neuronal necrosis of a very limited nature in only 60% of the animals and was defined as the minimal effective neurotoxic dose in the 4-day-old mouse. Neuronal loss was not detected in any animals treated with less than 0.35 mg/g of the amino acid whereas lesions became more extensive as the dose was increased to 0.5 mg/g. Glutamate was measured in the arcuate nucleus and plasma 0, 15, 30, 60 and 90 min after injection. These data indicated that duration of glutamate accumulation in the arcuate nucleus may be as important a variable in producing neuronal degeneration in the hypothalamus as concentration of the amino acid in that nucleus.
Isoxsuprine Infusion to the Pregnant Rabbit and Its Effect on Fetal Lung Surfactant
Authors: Enhorning Goran , Chamberlain Dean , Contreras Carlos , Burgoyne Rosmarie , Robertson Bengt
Published: September 2009

Rabbit does, pregnant on the 28th day, were infused with isoxsuprine 2.5 mg/kg body weight/h in 50 ml 5% glucose, or with glucose only. The isoxsuprine caused maternal heart rate to increase and blood pressure, mean and diastolic, to decrease. The volume of fetal pulmonary fluid (FPF) and the wet lung weight/body weight ratio were significantly lowered by isoxsuprine. Lecithin/sphingomyelin ratio of FPF in isoxsuprine-infused animals was higher, compared with controls, not infused. Minimal surface tension of FPF, evaluated with pulsating bubble, was significantly lower in treated fetuses. Histologic examination of the fetal lungs after fixation with potassium dichromate and mercuric chloride showed that in isoxsuprine-treated litters FPF contained more granular and sudanophilic material. The results offer further evidence that isoxsuprine causes dehydration of fetal lungs and a release of pulmonary surfactant.
Pyrimidine Metabolism in Erythrocytes of the Newborn
Authors: Tax W.J.M. , Veerkamp J.H. , Schretlen E.D.A.M.
Published: September 2009

Activities of orotate phosphoribosyltransferase and orotidine-5′-phosphate decarboxylase were found to be significantly higher in erythrocytes from newborn infants than in erythrocytes from adults, and approximated those observed in patients with deficiency of hypoxanthine-guanine phosphoribosyltransferase. Enzyme activities were increased to a varying extent in patients with reticulocytosis. The results are discussed in relation to red cell age and stabilization of the enzymes by phosphoribosylpyrophosphate. Pyrimidine-5′-nucleotidase was assayed by a new radiochemical method involving thin-layer chromatography for separation of product from substrate. Enzyme activity was higher with orotidine monophosphate than with uridine monophosphate. The activity of this enzyme was similar in erythrocytes of newborns and adults.
Postnatal Development of Renal Function in Piglets: Glomerular Filtration Rate, Clearance of PAH and PAH Extraction
Authors: Friis Christian
Published: September 2009

Glomerular filtration rate (GFR), estimated as clearance of inulin, and clearance of p-aminohippuric acid (CPAH) were measured in 32 unanaesthetized piglets 1–62 days of age. During this period of time, GFR increased from 0.27 to 0.59 ml/min/g kidney and CPAH increased from 1.02 to 1.72 ml/min/g kidney. At 8 weeks of age, GFR and CPAH equaled adult values. In addition, renal PAH extraction (EPAH) was estimated in 12 anaesthetized piglets aged 1–79 days. EPAH increased from 0.75 at birth to 0.86 (adult value) at 3 weeks of age. The result shows a postnatal increase in renal functions in piglets, but the development from birth to adult level was less pronounced than seen in other animal species.
Psychopathological Correlates of Lifetime Anxiety Comorbidity in Bipolar I Patients: Findings from a French National Cohort
Authors: Azorin Jean-Michel , Kaladjian Arthur , Adida Marc , Hantouche Elie G. , Hameg Ahcene , Lancrenon Sylvie , Akiskal Hagop S.
Published: September 2009

Background: Despite numerous studies on the comorbidity of bipolar and anxiety disorders, there is no satisfactory psychopathological model for their overlap. Method: 1,090 hospitalized patients meeting DSM-IV criteria for a manic episode of bipolar I disorder were subtyped according to the presence or not of lifetime anxiety comorbidity and assessed for demographic, illness course, clinical, associated condition, temperament, and treatment characteristics. Results: Lifetime anxiety comorbidity, defined as presence of at least one anxiety disorder in lifetime, was found in 27.2% (n = 297) of the sample. Compared to patients without such a comorbidity (n = 793), those who had it experienced a higher number of mood episodes and suicide attempts in the previous year, more stressors, organic disorders and less free intervals; furthermore, they showed more temperaments with depressive features and complex treatment. At study entry, they also experienced manic episodes with higher levels of depression, psychosis and hostility. The following independent variables were associated with lifetime anxiety comorbidity: higher scores on the Montgomery-Åsberg Depression Rating Scale, depressive temperament, irritable temperament, higher scores on the Scale for the Assessment of Positive Symptoms, episodes without free intervals and at least one stressor before the index episode. Conclusions: Factors associated with lifetime anxiety comorbidity in bipolar I patients may be integrated into a comprehensive diathesis-stress model emphasizing the role of irritable temperament as a source of mood instability and stress, and interacting with other temperamental characteristics to trigger the outbreak of both anxiety and bipolar symptoms.
Phototherapy: the Cause of Increased Enterohepatic Circulation of Bilirubin in Newborn Infants?
Authors: Jirsová Věra , Hodr Roman
Published: September 2009

The unconjugated/conjugated bilirubin ratio which was examined in the feces of 17 newborn infants submitted to phototherapy, was approximately 1:1 before, during and after the treatment. These results are not in keeping with those of Lund and Jacobsen who demonstrated an increased concentration of unconjugated bilirubin in duodenal bile. From this discrepancy one can deduce the unfavorable hypothesis that phototherapy stimulates the intestinal reabsorption of unconjugated bilirubin to the circulation.
Absorption of Orally Administered Bovine Prolactin by Neonatal Rats
Authors: Mulloy A.L. , Keen S.J. , Malven P.V.
Published: September 2009

Neonatal rats received by esophageal administration 400 ng bovine prolactin (bPRL) in 0.5 ml of diluent. Blood serum was collected by decapitation at intervals of 15, 30, 45 and 90 min after administration. Pooled samples of rat sera were assayed for the presence of immunoreactive bPRL using radioimmunoassay procedures validated for that purpose. Significant quantities of bPRL were detected in sera from 7- and 8-day-old rats at 30 and 45 min after oral administration. However, there was no bPRL detected in sera from 7-day-old rats at 15 or 90 min after administration. There was also an absence of detectable bPRL at 45 min after administration in rats between 9 and 14 days of age. Rats older than 8 days apparently lose the ability to absorb oral bPRL or become more able to degrade the hormone.
Heterogeneity of Fetal Hemoglobin in Severe α-Thalassemia
Authors: Vedvick Thomas S. , Wheeler Steven A. , Koenig Harold M.
Published: September 2009

The heterogeneity of residue 136 of the 7-chain of human hemoglobin has been determined for a patient afflicted with severe α-thalassemia. Separation of the cord blood sample into the various constituent hemoglobins A, F, FI and Bart’s were done on a column packed with DEAE Sephadex. The amount of glycine or alanine at position 136 was determined for hemoglobins F, FI and Bart’s. The ratios determined for all three hemoglobins indicated that the Gγ/Aγ ratio is the same for all three fractions and is similar to that observed in normal cord blood samples.
Electrolyte Composition of Fetuses, Placentas, and Maternal Plasma during the Last Trimester of Gestation in the Rat
Authors: Greizerstein Hebe B. , Abel Ernest L.
Published: September 2009

Pregnant rats were sacrificed during their last trimester of pregnancy. Maternal plasma levels of calcium and zinc decreased during gestation, whereas calcium and zinc levels increased in fetuses as gestation progressed. Although sodium and potassium levels remained relatively constant in maternal plasma, the levels of these electrolytes in fetuses decreased with gestation. Magnesium levels remained relatively unchanged in both maternal plasma and fetuses. The changes in placenta electrolyte content resembled the pattern of changes in fetuses.
Effects of Anemia and Growth Retardation on Respiratory Activity in the Piglet
Authors: Lee John C. , Downing Evans
Published: September 2009

Respiratory activity (RA) was assessed in a piglet model by giving chloralose (Ch), 6 mg/kg i.v. every 2 min, until the appearance of apnea. The total cumulative dose of Ch (mg/kg) which produced permanent apnea (lethal dose, LD) was determined. The slope of the dose-respiratory frequency curve (R=ae––λch) was also computed. The LD of Ch increased progressively with age, while respiratory frequency (λ) decreased. However, in piglets with severe spontaneous anemia (hematocrit < 10%), the LD of Ch was less than half that expected for the age groups, and the rate of reduction of γ was much greater. The enhanced sensitivity to inhibition of RA may relate in part to anemia with reduced O2-carrying capacity to the CNS, and in part to growth retardation with delayed respiratory center maturation.
Distribution of Fluid between Extracellular and Intracellular Compartments in the Heart, Lungs, Liver and Spleen of Neonatal Rats
Authors: Johanson Conrad E.
Published: September 2009

The volume of fluid in various tissue compartments of thoracic and abdominal viscera in neonatal rats has been calculated from the steady state distribution of radioindicators. During the first 3 weeks after birth, the volume of extracellular fluid (3H-inulin space) decreases at a similar rate (ca. 0.04 ml/g tissue/week) in heart, lungs, liver and spleen. Over the same postnatal period, the 51Cr tagged erythrocyte space (an estimate of vascularity) remains relatively constant in liver, increases slightly in the heart and spleen, and rises substantially (3-fold increase) in the lungs. The volume of parenchymal cell water, calculated from data for tissue water content and radioindicator spaces, tends to increase with age. However, the distribution of fluid between extracellular and intracellular compartments in 3-week-old animals is similar to that in adults.
Δ9- and Δ6-Desaturase Activities of the Ovine Placenta and Their Role in the Supply of Fatty Acids to the Fetus
Authors: Shand John H. , Noble Raymond C.
Published: September 2009

Although the fatty acid compositions of the total lipids of the sheep placenta and fetal plasma were shown to be broadly similar, they differed significantly from the fatty acid composition of the maternal plasma unesterified fatty acids, the plasma lipid component from which the fetus derives almost all of its requirements for pre-formed fatty acids. In particular, the placental and fetal plasma lipids displayed a 3-fold higher oleic acid/stearic acid ratio and contained a significantly higher proportion of arachidonic acid than the maternal unesterified fatty acids. These differences correlated well with the high Δ9- and ▵6-desaturase activities, respectively, shown to be present in sheep placental tissue in vitro. The levels of these enzymes in placental tissue contrasted with the relatively low desaturase activities found to be present in adult and neonatal sheep liver and in the placentas of other, non-ruminant, species. The possible role of such high levels of desaturase activity in the sheep placenta is discussed in relation to the particularly poor essential fatty acid status imposed upon the fetal ruminant.
Prematurity in the Rat
Authors: Cuezva J.M. , Medina J.M.
Published: September 2009

Changes in liver glycogen, plasma glucose, lactate, alanine and glycerol concentrations in term and preterm newborn rats breathing pure oxygen have been studied. The time courses of lactate and pyruvate concentrations in the livers of term and preterm rats breathing air or pure oxygen have also been investigated. The increased oxygen supply enhanced plasma glucose, lactate and alanine utilization while the rate of glycogenolysis was not affected. In these conditions, the resistance to lactate utilization observed in preterm newborns breathing air was overcome. The liver lactate/pyruvate ratio sharply decreased immediately after delivery in term and preterm rats breathing pure oxygen and in term rats breathing air. However, this decrease was delayed for 30 min in preterm newborns breathing air. These results suggest that the preterm rat suffers a defective oxygen supply to the tissues which results in a transient resistance to lactate utilization.
Localization of Digoxin in Sheep Myocardium by Immunofluorescent Microscopy
Authors: Berman William , Musselman Jude , Shortencarrier Ramona
Published: September 2009

6 newborn and 6 adult sheep were treated intravenously with digoxin for 2 weeks prior to sacrifice. Plasma and myocardial concentrations of digoxin were determined at steady state; the myocardial/plasma digoxin ratio was similar for the newborn and adult sheep. An immunofluorescent technique was used to localize digoxin within the myocardium. The pattern of fluorescence also did not vary with age. These studies show no age-related differences in the penetration or localization of digoxin within the heart. A simple immunofluorescent technique for the localization of digoxin within the heart is described.
A Spectrophotometric Assay of Skin Bilirubin in Adult Gunn Rats
Authors: Bessard G. , Chouraqui J.-P. , Rambaud P.
Published: September 2009

The present study was undertaken to assess the value of a spectrophotometric method for the assay of bilirubin content in Gunn rat skin. The pigment extraction was performed by incubating skin strips in a barbital-acetate buffered methanol-chloroform mixture at pH 7 for 90 min. The procedure yielded an overall recovery average of 93 ± 9% which was not influenced when the incubation time was varied from 1 to 2.5 h. The bilirubin concentration in skin extracts was calculated from spectrophotometric absorbance readings and according to the molar extinction coefficient of the pigment in chloroform. Bilirubin appeared to remain stable during the analytical process. The mean bilirubin content as measured by this method was 1.88 μmol/100 g (1.1 mg/100 g). It is concluded that the proposed method is well suited for the investigation of bilirubin skin metabolism.
Fatty Acid Biosynthesis in Sheep Placenta and Maternal and Fetal Adipose Tissue
Authors: Christie W.W. , Noble R.C.
Published: September 2009

The rates of fatty acid synthesis from 3H2O and [1-14C]-acetate as substrates have been determined in sheep placental tissue and maternal and fetal adipose tissues in vitro. The tissue was obtained from sheep approximately 28 or 3 days from parturition. Placental tissue synthesised fatty acids at an appreciable rate and newly synthesised fatty acids were apparently transferred from the tissue to the incubation medium. When the results were expressed per unit of tissue weight, fetal adipose tissue synthesised fatty acids much more rapidly than did placental tissue but because there was much more of the latter tissue, the total amounts of fatty acids synthesised by each were comparable. However, it appeared that most of the fatty acids (approximately 80%) in the fetus must have been derived from the maternal plasma. The nature of the fatty acids synthesised de novo was investigated, as was the manner of their esterification.
Urinary Prostacyclin and Thromboxane A2 Metabolites in Preterm and Full-Term Infants in Relation to Plasma Renin Activity and Blood Pressure
Authors: Joppich Rüdiger , Häuser Irmgard
Published: September 2009

The metabolites of prostacyclin and thromboxane A2, 6-ketoprostaglandin F1α and thromboxane B2, were measured in urine of 27 preterm and 21 full-term infants. Their values were analyzed in correlation to plasma renin activity, urinary function, and systolic blood pressure. The 6-ketoprostaglandin F1α excretion was significantly higher in the preterm infants as compared to the full-term infants (p < 0.001). This decrease of 6-ketoprostaglandin F1α in the full-term infants was associated with a decrease in the plasma renin activity and an increase in systolic blood pressure. In contrast, the urinary excretion of thromboxane B2 was low, without significant difference between the two groups, and there was no correlation to the parameters mentioned above.
Ovarian Hilar Cells and Testicular Leydig Cells in Anencephaly
Authors: Zondek Lilly H. , Zondek Theodor
Published: September 2009

The presence of ovarian hilar cells in anencephaly has been investigated and compared with the presence of testicular Leydig cells in the same condition. The examination of 29 anencephalic ovaries and 49 controls showed that up to 36 weeks of gestation there was a preponderance of ovarian hilar cells in anencephalic monsters as compared with controls. Similar observations were made with regard to ovarian follicles which showed more pronounced maturational changes than controls. However, during the last month of gestation both these processes were more marked in the controls. These findings are in marked contrast to our previous observations on the testes in anencephalic monsters which showed significantly less Leydig cells than controls throughout the third trimester of pregnancy. It is assumed that these appearances are due to the fact that testes and ovaries are not strictly comparable structures and may, therefore, react in a different way to hormonal stimulation. This is of particular interest as the placental chorionic gonadotrophin levels which stimulate the development of testicular Leydig cells and, supposedly, the development of ovarian hilar cells are normal in anencephaly.
Effect of a Synthetic Folic Acid Analogue, 9-Methyl-Pteroylglutamic Acid, on Fetal Chondrogenesis: Ultrastructural Observations
Authors: Schmidt Richard R. , Slobodian Stephen A. , Chepenik Kenneth P. , Cotler Jerome M.
Published: September 2009

Maternally administered folic acid antagonists (x-methyl-PGA and 9-methyl-PGA) are known to produce various skeletal malformations in the neonate. These defects are thought to be due in part to abnormal metabolism and/or deposition of various extracellular matrix components, i.e., collagen and glycosaminoglycans. Experimental reduction of glycosaminoglycan biosynthesis in vitro has been shown previously to alter the spatial orientation and normal pattern of collagen fibrillogenesis. Furthermore, dietary withdrawal of folic acid concomitant with maternal administration of 9-methyl-PGA has been shown to result in abnormal collagen, uronic acid, and hexosamine metabolism by fetal limbs. In the present study pregnant rats were exposed to a transitory folic acid deficiency from day 11 to 14 of gestation and fetal tibias (mid-diaphyseal region) were examined with the electron microscope on day 18 of gestation. Although we were unable to ascertain any aberrant patterns of fibrillogenesis and orientation with respect to collagen, this particular teratogenic regimen resulted in an altered pattern of chondrocyte development when observed at the ultrastructural level.
Oxygen Consumption in Premature Infants in an Incubator of Proven Clinical Efficacy
Authors: LeBlanc Michael H.
Published: September 2009

Oxygen consumption was measured under carefully controlled conditions during non-REM sleep in 16 infants less than 1,500 g in a computer-controlled incubator and a skin servo-controlled incubator. Oxygen consumption was 7.16 ± SE 0.35 ml/kg/min in the computer-controlled incubator and 6.84 ± SE 0.37 ml/kg/min in the skin servo-controlled incubator. Oxygen consumption was similar in the two incubator systems.
Postnatal Increase in the Metabolism of Leucine and Valine
Authors: Fuller Gregory N. , Bell Margaret E. , Wiggins Richard C.
Published: September 2009

The catabolism of tritium-labeled leucine, valine, and glycine was determined by measuring the appearance of tritium-labeled water at various postnatal and adult ages in rats. Results for leucine and valine show a marked increase in the formation of labeled water during the 3rd postnatal week. The partial exclusion of leucine and valine from brain, as a result of the blood-brain barrier, particularly enhances observation of labeled water formation in that the product (water) and precursor (amino acid) are largely separated (supporting experiments demonstrate the prior existence of the blood-brain barrier for leucine). Results for glycine indicate its extensive metabolic degradation at all postnatal ages. These data indicate that the metabolic rate of intraperitoneally administered, radioactively labeled leucine and valine changes appreciably during early postnatal development. The early postnatal manifestation of human disorders of branched-chain amino acid metabolism is consistent with the chronology of development in the rat.
Metabolic and Hormonal Response to Endotoxin Fever in Fed and Starved One-Week Rabbits
Authors: Molnar D. , Milner R.D.G.
Published: September 2009

The metabolic and hormonal effect of Escherichia coli endotoxin injected intraperitoneally was studied in fed and starved rabbits aged 6–9 days. Fed rabbits responded to endotoxin with fever, starved animals became hypothermic. Endotoxin caused a transient rise in blood glucose in both groups which was associated with a rise in plasma insulin concentration. Blood glycerol levels fell only in starved rabbits, and hydroxybutyrate concentration in both groups following endotoxin treatment. No change in blood pyruvate, lactate, alanine, or acetoacetate level was observed in either group.
Effect of Sodium Benzoate on the Cutaneous Bilirubin Content of the Adult Gunn Rat
Authors: Bessard G. , Chouraqui J.-P. , Remy C. , Rambaud P.
Published: September 2009

Na benzoate, which dissociates intravascular bilirubin-albumin complexes, might thus have the potential for driving bilirubin from the plasma into tissues such as the skin. We investigated this hypothesis in the adult Gunn rat. As others, we observed an early fall in blood bilirubin concentration after intraperitoneal Na benzoate injection, without any change in skin bilirubin content. Nevertheless, we observed a significant decrease (p < 0.01) in skin bilirubin content at 24 and then 48 h after Na benzoate injection, at which times blood bilirubin remained at a low level. The phenomenon was reversible since, at 8 days after Na benzoate injection, blood and skin bilirubin contents had returned to control values. Regarding the decrease in skin bilirubin content after Na benzoate injection we described a dose-effect relationship. So, we could not confirm our hypothesis. We concluded that the phenomenon we observed is probably due to a shift in the distribution equilibrium of the pigment between serum, skin and other tissues.
Pressure Profiles in Neonatal Spontaneously Hypertensive Rats
Authors: Gray Sarah D.
Published: September 2009

Spontaneously hypertensive (SHR) and normotensive (WKY) rats were studied on the day of birth and from 11 days to 12 weeks of age to determine whether increases in arterial pressure are detectable in the early neonatal stage of genetic hypertension. The data show that there are significant increases in systolic, diastolic, and mean pressures in neonatal SHR. Heart rate and heart weight/body weight ratios are also increased and indicate that many parameters, which have been shown to be significantly altered in adult rats in both the early and advanced stages of the disease, are already altered at birth.
Plasma Amino Acids and Glucose Levels in the Rat Fetus and Dam after Chronic Maternal Alcohol Consumption
Authors: Marquis Sandra M. , Leichter Joseph , Lee Melvin
Published: September 2009

To evaluate the effect of chronic maternal alcohol consumption on plasma amino acid and glucose levels in both the fetus and the mother, female Sprague-Dawley rats were divided into 3 dietary treatment groups. Group 1 (alcohol) was fed ad libitum a stock diet plus 20% alcohol in drinking water for at least 4 weeks before mating and 30% alcohol during gestation. Group 2 was pair-fed the stock diet plus corn starch calorically equivalent to the amount of alcohol consumed by group 1 animals. Group 3 (control) received the stock diet and water ad libitum. On day 21 of gestation the fetuses of alcohol-treated dams weighed significantly less than those of the control and pair-fed groups. Fetal plasma glucose levels were significantly lower in the alcohol group when compared to those of the pair-fed and control groups, while the maternal glucose levels were similar in all three treatment groups. Plasma amino acid concentrations showed no corresponding trends in mother and fetus. Only proline was significantly reduced and alpha-amino-n-butyric acid elevated in the alcohol-treated dams when compared to the pair-fed and control rats. In the fetal plasma, only aspartic acid was significantly lower in the alcohol group when compared to the other two groups. A moderate degree of dehydration occurred in the alcohol-treated dams, but plasma albumin was within normal levels. It is concluded that the marked decrease in the concentration of plasma glucose in alcohol-exposed fetuses may be partially responsible for their retarded growth.
Cholesterol Oxidation and 7α-Hydroxylation during Postnatal Development of the Rat
Authors: Hahn P. , Innis S.M.
Published: September 2009

The activity of rat hepatic cholesterol 7α-hydroxylase is low in the suckling period and rises at weaning. The oxidation of intraperitoneally administered 26-14C-cholesterol to 14CO2 is also low in suckling rats and increases with age as does the radioactivity in the plasma. In contrast, propionic acid oxidation to CO2 is much more rapid, suggesting that the side chain cleavage of cholesterol is not a rate-limiting process.
Relationship of Alpha-Fetoprotein and Albumin in Fetuses and Neonates from Genetically Lean and Obese Swine
Authors: Stone Roger T.
Published: September 2009

The relationship between alpha-fetoprotein and albumin during fetal development in two genetic lines of swine selected for either high backfat (obese) or low backfat (lean) has been investigated. Differences in serum concentrations, in vitro synthesis by liver slices, and cell-free translational activity of total tissue RNA for alpha-fetoprotein and albumin were determined at days 40, 60, and 80 of gestation and in newborn pigs. Serum concentrations of alpha-fetoprotein tended to be greater in pigs from the lean line compared to those from the obese line during the fetal stages, but no differences were observed in newborn pigs. Similar differences between the two lines were observed for alpha-fetoprotein synthesis by liver slices and cell-free mRNA translational activity. Serum albumin concentrations and the relative synthesis by liver slices were between 2- and 3-fold greater in the obese pigs compared to the lean pigs at days 60 and 80 of gestation and at birth. Albumin mRNA activity increased with fetal age in a manner similar to increases observed in serum concentrations and in vitro synthesis; however, no differences in the cell-free albumin mRNA activity in total liver RNA extracts from the two lines could be detected. The overall pattern of increasing albumin and decreasing alpha-fetoprotein concentrations in serum with increasing fetal age was similar in the two lines. Results from dot-blot hybridizations of total liver RNA to a heterologous recombinant mouse albumin cDNA probe suggested that increasing albumin synthesis with increasing age can be attributed to an increasing abundance of albumin mRNA. From these results, it is proposed that differences in serum protein (albumin) synthesis by the fetal liver in these genetic lines of swine reflect the degree of overall physiological maturity at birth which accounts for about a 20% neonatal survival advantage of pigs in the obese line over those in the lean line.
Hyperoxia Effects on Pulmonary Pressure: Volume Characteristics and Lavage Surfactant Phospholipid in the Newborn Rabbit
Authors: Ward Jill A. , Roberts Robert J.
Published: September 2009

The effect of hyperoxia (> 95%) on surfactant phospholipid recovered by lavage and pulmonary pressure:volume characteristics was studied in rabbits exposed from birth through 4 days of life. Decreased surfactant phospholipid (μg/mg dry lung weight) in the airways was observed as early as 6 h and persisted through 96 h of life in hyperoxiaexposed animals. The composition of lavage phospholipids and fatty acid profile of phosphatidylcholine was not altered by hyperoxia. Pressure:volume analysis revealed a decrease in maximum lung distensibility (V30, volume at 30 cm pressure) at 48 and 96 h and a decrease in inflation compliance (P30i, pressure on inflation to 30% V30) at 48 h of life in newborn pups exposed to hyperoxia. Pressure:volume changes in both male and female newborns were observed with hyperoxia exposure. However, only female pups exhibited a decrease in lavage phospholipid content as measured at 48 h. These data suggest that the newborn rabbit surfactant system is susceptible to oxygen toxicity. In addition to age-related differences, sex differences may exist with regard to susceptibility to hyperoxia. Subtle alterations in the surfactant system at this critical time of rapid lung development could have long lasting effects on lung function.
Effect of Dopamine Infusion on Pulmonary Gas Exchange in Lambs
Authors: Truog William E. , Standaert Thomas A.
Published: September 2009

We studied the effects of dopamine HCI, a potent vasoactive catecholamine, on ventilation-perfusion matching and pulmonary hemodynamics in infant lambs breathing room air and a hypoxic gas mixture. Neither alveolar hypoxia alone, nor dopamine infusion alone during room air breathing, significantly altered the ventilation-perfusion (VA/Q) distribution or intrapulmonary shunt size. Dopamine infusion during room air breathing did increase pulmonary blood flow (PBF; p < 0.05). Dopamine infusion plus alveolar hypoxia was associated with a significant increase in minute ventilation, PBF, and pulmonary arterial pressure (Ppa), a doubling (p < 0.01) of the fraction of PBF to low VA/Q lung regions, and a significant increase (p < 0.05) in intrapulmonary shunt when compared to results obtained during hypoxic gas breathing without dopamine infusion. We conclude the dopamine infusion increased PBF during room air breathing, and perturbed ventilation-perfusion matching and increased Ppa and minute ventilation with no net change in arterial pO2 during the breathing of a hypoxic gas mixture.
Changes in Cysteine Dioxygenase and Cysteinesulfinate Decarboxylase Activities and Taurine Levels in Tissues of Pregnant or Lactating Rat Dams and Their Fetuses or Pups
Authors: Kuo Shiu-Ming , Stipanuk Martha H.
Published: September 2009

The level of taurine and the activities of the two enzymes involved in its synthesis, cysteine dioxygenase and cysteinesulfinate decarboxylase, were measured in tissues of rat dams during pregnancy and lactation and in their fetuses or pups. The most marked changes observed in the dams included an increased hepatic taurine concentration in late pregnancy (20 days), a decreased plasma taurine concentration during late pregnancy and throughout lactation, and a decrease in tissue cysteine dioxygenase activity in late lactation (20 days). These observations suggest that the dam’s taurine pools may be an important source of taurine for secretion in the milk and that pregnant dams may prepare for the onset of lactation by accumulating additional taurine in the liver. There was little if any correlation between the activities of either of these key enzymes in taurine synthesis and tissue taurine levels. The taurine concentrations in liver, brain, heart and plasma of the young decreased between 1 day before birth and 20 days of age. Cysteine dioxygenase and cysteinesulfinate decarboxylase specific activities increased in the brains of pups between birth and 20 days of age, and cysteinesulfinate decarboxylase activity increased in the livers of pups between birth and 20 days of age. Cysteinesulfinate decarboxylase activity in 80-day-old male rats was more than six times that in female littermates, but no effects of sex on cysteine dioxygenase activity or tissue taurine concentrations were observed.
Perinatal Development of the Small Intestine and Pancreas in Rat and Spiny Mouse
Authors: Lamers W.H. , Mooren P.G. , Charles R.
Published: September 2009

Rat (Raitus norvegicus)and spiny mouse (Acomys cahirinus)are closely related species that mainly differ in the developmental timing of birth. A comparison between the developmental profiles of some characteristic enzymes of the small intestine (lactase and sucrase) and of the pancreas (amylase) of both species was carried out to elucidate the question to what extent these enzymic profiles and hence the maturation of these organs was related to the process of birth. It was found that these organ-specific enzymes become first detectable at the same developmental stage in both species. Likewise, the weaning phase of the enzymic profiles occurred at the same developmental time point in both species. It is argued that both the first appearance and the weaning increase in enzyme activity follow an inherent biological program that can only be modulated by hormones. In contrast, the perinatal phase of the enzymic profile is completely dependent on the developmental timing of birth, and therefore appears not to be anchored to a particular developmental time point but rather to be dependent on birth-associated (hormonal) adaptation. In accordance with this hypothesis it was found that the development of the microscopic anatomy of the small intestine proceeded independently of the functional adaptation of the intestine to the process of birth.
Endocrine Activity in Preterm and Full-Term Lambs
Authors: Wrutniak Chantal , Cabello Gérard
Published: September 2009

Neonatal endocrine status was studied in 14 lambs born 7 days before term, after estrogen injection into the ewes, and in 15 full-term animals. Plasma cortisol and triiodothyronine (T3) levels were depressed during the first hours of life in preterm lambs and plasma reverse T3 levels were significantly higher than in controls. The rise in plasma cortisol levels after Synacthen injection was significantly lowered by prematurity, suggesting reduced sensitivity of the adrenal cortex to ACTH. After ovine TSH injection, plasma thyroxine (T4) levels increased during a shorter period of time in preterm lambs, resulting in a lowered T4 rise; the T3 response was not affected by prematurity. After TRH injection, the rises in plasma T3 and T4 levels were significantly higher in preterm than in full-term lambs, suggesting a pituitary hypersensitivity to TRH linked to prematurity. Moreover it appeared that the response of reverse T3 to TSH or TRH was very weak.
Binding between heparin and the integrin VLA-4
Authors: Schlesinger Martin , Simonis Dirk , Schmitz Patrick , Fritzsche Juliane , Bendas Gerd
Published: September 2009

Heparin possesses antimetastatic effects that were related to various molecular mechanisms beyond anticoagulant activities. The ability of heparin to interfere with the function of adhesion receptors in the metastatic course appears as a promising therapeutic approach. This refers to numerous findings that heparin attenuates metastasis in a selectin-dependent manner. We recently demonstrated that heparin interferes with the integrin VLA-4 on murine melanoma cells binding to VCAM-1. To confirm this activity and to obtain further insight into molecular recognition of heparin by VLA-4, we investigated the inhibition of VLA-4 mediated binding of human melanoma MV3 cells to immobilized VCAM-1 by different heparins. The size of heparin has an important impact on inhibition. Unfractionated heparin (UFH) and tinzaparin, a low-molecular-weight heparin (LMWH) representing a mean of about 18– 20 monomers, displayed high inhibitory activity. Fractionating tinzaparin to 14– 18 monomers reduced inhibition slightly, while the pentasaccharide fondaparinux was without effects. To confirm molecular recognition of tinzaparin by VLA-4,a surface acoustic wave-biosensor was applied. A VLA-4 containing membrane preparation of MV3 cells was immobilised at the sensors to allow for detection of kinetic binding constants of tinzaparin compared to VCAM-1. Tinzaparin binds to VLA-4 with affinity in the low micromolar range (4.61× 10−6 M), which clearly indicates specific molecular recognition. Furthermore, tinzaparin displays a nearly identical koff compared toVCAM-1 (5.13× 10−3 s-1 versus 3.44× 10–3 s-1) which is evident for interference with the ligand binding. The data provide evidence for a direct confirmation of heparin binding to VLA-4 and thus, contribute to understand the antimetastatic activity of heparin.
The Tainted Heparin Story: An Update
Authors: Guerrini Marco , Shriver Zachary , Bisio Antonella , Naggi Annamaria , Casu Benito , Sasisekharan Ram , Torri Giangiacomo
Published: September 2009

Recently, certain batches of heparin have been associated with an acute, rapid onset of serious side-effects indicative of allergictype reactions.These reports generated significant concern regarding the possible presence of a dangerous contaminant within heparin and highlighted the need to re-assess the purity criteria of heparin preparations for clinical use. Given the nature of the array of all possible contaminants, traditional screening tests cannot safely differentiate between contaminated and uncontaminated heparin preparations. Monoand bi-dimensional NMR spectroscopy are powerful techniques that are able to detect and quantify a wide variety of potential sulfated polysaccharide contaminants. As such, these techniques are powerful tools for the analysis and assessment of heparin preparations.
Structural features of low-molecular-weight heparins affecting their affinity to antithrombin
Authors: Bisio Antonella , Vecchietti Davide , Citterio Laura , Guerrini Marco , Raman Rahul , Bertini Sabrina , Eisele Giorgio , Naggi Annamaria , Sasisekharan Ram , Torri Giangiacomo
Published: September 2009

As part of a more extensive investigation on structural features of different low-molecular-weight heparins (LMWHs) that can affect their biological activities, Enoxaparin,Tinzaparin and Dalteparin were characterised with regards to the distribution of different chain length oligosaccharides as determined by size-exclusion (SE) chromatography, as well as their structure as defined by 2D-NMR spectra (HSQC). The three LMWHs were also fractionated into high affinity (HA) and no affinity (NA) pools with regards to their ability to bind antithrombin (AT).The HA fractions were further subfractionated and characterised. For the parent LMWHs and selected fractions,molecular weight parameters were measured using a SE chromatographic system with a triple detector (TDA) to obtain absolute molecular weights. The SE chromatograms clearly indicate that Enoxaparin is consistently richer in shorter oligosaccharides than Tinzaparin and Dalteparin. Besides providing the content of terminal groups and individual glucosamine and uronic acid residues with different sulfate substituents, the HSQC-NMR spectra permitted us to evaluate and correlate the content of the pentasaccharide, AT-binding sequence A-G-A*-I-A (AT-bs) through quantification of signals of the disaccharide sequence G-A*.Whereas the percent content of HA species is approximately the same for the three LMWHs, substantial differences were observed for the chain distribution of AT-bs as a function of length, with the AT-bs being preferentially contained in the longest chains of each LMWH. The above information will be useful in establishing structure-activity relationships currently under way. This study is therefore critical for establishing correlations between structural features of LMWHs and their AT-mediated anticoagulant activity.