bluuebunny/crossref_metadata_2025 huggingface dataset:
Demonstrating Wavelength Dependency on Medium Density
Authors: Welch John
Published: September 2009

An instructor teaching an optics class recently asked me for a demo to show how the wavelength changes as a wave moves between materials of different indices of refraction. I decided to play with standing waves, since they're easier to set up than stable traveling waves. I used our standard PASCO Wave Driver and elastic cord, but I made a cord that changes its linear mass density about halfway along its length. To do this, I bent a section of the cord back on itself and twisted it into a “twine” that has a nice uniform mass density. (See Fig. 1 and also the article by my friend Norm Kidder for tips on how to twist cord into twine: http://www.primitive-ways.com/cordage.html). I glued the loose end to the main cord to hold it in place. When the cord is driven, it can be tuned as usual to get nice standing waves, but in this case the wavelengths will be different in the different sections, varying inversely as the square root of the mass density (see Fig. 2). It's a very nice demo: The standing waves add a bit of extra complexity, but it's worth it to get nice stable measureable wavelengths.
MicroReview by the Book Review Editor: Heavenly Errors: Misconceptions about the Real Nature of the Universe: Neil F. Comins
Authors: Hubisz John L.
Published: September 2009

Heavenly Errors: Misconceptions about the Real Nature of the Universe, by Neil F. Comins and published by Columbia University Press, New York, NY, 10023, pp. xi+244 (2001), $27.95, hardback.
Children and Population Biobanks
Authors: Gurwitz David , Fortier Isabel , Lunshof Jeantine E. , Knoppers Bartha Maria
Published: September 2009

Access to samples and individual DNA sequence data from children included in population biobanks should, when feasible, await their consent as adults.
Fire As an Engineering Tool of Early Modern Humans
Authors: Brown Kyle S. , Marean Curtis W. , Herries Andy I. R. , Jacobs Zenobia , Tribolo Chantal , Braun David , Roberts David L. , Meyer Michael C. , Bernatchez Jocelyn
Published: September 2009

Friendly Fire

Hints of the use of more advanced materials by humans, including symbolic marking and jewelry, appear about 75,000 years ago or so in Africa.

Brown
et al.

(p.
859
; see the Perspective by

Webb and Domanski

) now show that these early modern humans were also experimenting with the use of fire for improved processing of materials. Replication experiments and analysis of artifacts suggest that humans in South Africa at this time, and perhaps earlier, systematically heated stone materials, including silcrete to improve its flaking properties in making tools.
Antennal Circadian Clocks Coordinate Sun Compass Orientation in Migratory Monarch Butterflies
Authors: Merlin Christine , Gegear Robert J. , Reppert Steven M.
Published: September 2009

Butterfly Navigation

Monarch butterflies migrate to Mexico from various parts of North America in the fall and navigate with the aid of Sun compass. This navigational mechanism, also employed by migratory birds, uses the circadian clock to compensate for the positional change of the Sun in the sky throughout the day. The mechanism behind time-compensated Sun compass orientation has remained obscure.

Merlin
et al.

(p.
1700
; see the Perspective by

Kyriacou

) now provide comprehensive data showing that the mechanism resides in the antennae of the butterflies, rather than the brain, as previously thought. The “antennal clocks” found in the monarchs probably provide the primary timing mechanism for Sun compass orientation. These findings reveal a further function for the antennae—a function that may extend widely to other insects that use this orientation mechanism.
Mechanistic Analysis of a Dynamin Effector
Authors: Lackner Laura L. , Horner Jennifer S. , Nunnari Jodi
Published: September 2009

Dynamin-Related Proteins' Little Helper

Dynamin-related proteins (DRPs) comprise a family of large guanosine triphosphatases that self-assemble to form different nucleotide-dependent structures that associate with and change the behavior of intracellular membranes. Many studies have focused on how dynamins function by themselves as machines. In cells, however, DRPs cannot function alone and require additional, associated proteins (DAPs) to perform their functions. The exact mechanistic roles that DAPs play are not known.

Lackner
et al.

(p.
874
) address this question using the mitochondrial division machine that requires the DRP, Dnm1. The Dnm1-associated protein, Mdv1, functions as a conformational and structural nucleator for Dnm1 self-assembly.
The Theory? Diet Causes Violence. The Lab? Prison
Authors: Bohannon John
Published: September 2009

In a more ambitious study than any before, psychologist Bernard Gesch is leading a research team hoping to replicate controversial results showing that nutritional supplements can reduce violence among prisoners.
Occupational physical activities, working hours and outcome of pregnancy: findings from the Southampton Women’s Survey
Authors: Bonzini M , Coggon D , Godfrey K , Inskip H , Crozier S , Palmer K T
Published: September 2009

Objectives:

To investigate risks of physical activity at work by pregnancy trimester, including the effects on head and abdominal circumference.

Method:

At 34 weeks of gestation we interviewed 1327 mothers from the prospective Southampton Women’s Survey (SWS); we asked about their activities (working hours, standing/walking, kneeling/squatting, trunk bending, lifting and night shifts) in jobs held at each of 11, 19 and 34 weeks of gestation, and subsequently ascertained four birth outcomes (preterm delivery, small for gestational age (SGA) and reduced head or abdominal circumference) blinded to employment history.

Results:

Risk of preterm delivery was elevated nearly threefold in women whose work at 34 weeks entailed trunk bending for >1 h/day. Small head circumference was more common in babies born to women who worked for >40 h/week. However, no statistically significant associations were found with SGA or small abdominal circumference, and preterm delivery showed little association with long working hours, lifting, standing or shift work.

Conclusions:

There is a need for more research on trunk bending late in pregnancy, and on the relationship of work to reduced head circumference. Our findings on several other occupational exposures common among pregnant workers are reassuring.
A Pterosaur from the Oldman Formation (Cretaceous) of Alberta
Authors: Russell Dale A.
Published: September 2009

A fragment of the proximal phalanx of a wing finger (IV) from the Oldman Formation (Campanian) of Alberta probably represents the first record of a pterosaur from Canada. The animal from which it was derived had a wingspan of about 3.5 m.
NONSTATIONARY MIXING AND THE UNIQUE ERGODICITY OF ADIC TRANSFORMATIONS
Authors: FISHER ALBERT M.
Published: September 2009

We define topological and measure-theoretic mixing for nonstationary dynamical systems and prove that for a nonstationary subshift of finite type, topological mixing implies the minimality of any adic transformation defined on the edge space, while if the Parry measure sequence is mixing, the adic transformation is uniquely ergodic. We also show this measure theoretic mixing is equivalent to weak ergodicity of the edge matrices in the sense of inhomogeneous Markov chain theory.
Galanin potentiates supramaximal caerulein-stimulated pancreatic amylase secretion via its action on somatostatin secretion
Authors: Barreto Savio G. , Carati Colin J. , Schloithe Ann C. , Toouli James , Saccone Gino T. P.
Published: September 2009

Galanin inhibits pancreatic amylase secretion from mouse lobules induced by physiological concentrations of caerulein via an insulin-dependent mechanism. We aimed to determine the effect and elucidate the mechanism of action of exogenous galanin on pancreatic amylase secretion induced by supramaximal concentrations of caerulein. Amylase secretion from isolated murine pancreatic lobules was measured. Lobules were coincubated with galanin (10−12–10−7M) and caerulein (10−7M). Lobules were preincubated with atropine (10−5M), tetrodotoxin (10−5M), diazoxide (10−7M), or the galanin antagonist galantide (10−12–10−7M) for 30 min followed by incubation with caerulein alone, or combined with galanin (10−12M). Lobules were also coincubated with combinations of galanin (10−12M), caerulein, octreotide (10−12–10−7M) or cyclo-(7-aminoheptanoyl-Phe-D-Trp-Lys-Thr[BZL]), a somatostatin receptor antagonist (10−9M). Amylase secretion was expressed as percent of total lobular amylase. Caerulein stimulated amylase secretion to 124% of control. Diazoxide pretreatment abolished the caerulein-stimulated amylase secretion, whereas atropine or tetrodotoxin caused a partial inhibition. Galanin (10−12–10−7M) potentiated caerulein-stimulated amylase secretion to 160% of control. Preincubation with a combination of atropine and diazoxide abolished the potentiating effect of galanin, indicating muscarinic receptor and insulin mediation. Preincubation with galantide abolished the galanin effect, implying galanin receptor involvement. Coincubation with caerulein, galanin, and octreotide significantly reduced the potentiating effect galanin. However, coincubation with the somatostatin receptor antagonist, alone or in combination with galanin, significantly increased caerulein-stimulated amylase secretion to a level comparable to the galanin potentiation. Taken together, these data suggest that, at supramaximal caerulein concentrations, galanin acts via its receptors to further increase caerulein-stimulated amylase secretion by inhibiting the caerulein-induced release of somatostatin.
Neonatal Period: Body Composition Changes in Breast-Fed Full-Term Newborns
Authors: Roggero Paola , Giannì Maria L. , Orsi Anna , Piemontese Pasqua , Amato Orsola , Moioli Claudia , Mosca Fabio
Published: September 2009

Background: Weight loss during initial days of life in healthy infants is known to consist of loss of both body solids and total body water. However, the nature of these body composition changes needs further investigation. Objective: To investigate the nature of changes in body composition that accompany weight loss during the first days of life in healthy term newborns. Methods: Body composition of healthy full-term newborns was assessed using air-displacement plethysmography. Cross-sectional (n = 262) and longitudinal samples (n = 28) were assessed during the first 4 and 5 days after delivery, respectively. Results: In the cross-sectional sample, mean body weight decreased significantly through day 4 (p < 0.001), mean fat mass (FM) and %FM decreased significantly (p = 0.005 and p = 0.031, respectively) by day 3. There was a significant decrease in mean fat-free mass on days 3 and 4 (p = 0.01 and p < 0.001, respectively). In the longitudinal sample, there was a significant decrease in mean body weight, FM and %FM (p < 0.001, p = 0.001, p = 0.013, respectively) by day 4. On day 5 there was a significant increase in mean body weight, FM and %FM (p < 0.001, p = 0.024, p = 0.036, respectively) when compared to day 4. There was no significant difference in mean FM and %FM values between day 1 and day 5. Conclusions: These results indicate that body composition changes are constituted by a reduction in both fat and fat free mass. However, a greater %FM is lost and consequently regained by day 5 when compared to fat-free mass.
Leukocyte Alkaline Phosphatase in the Newborn
Authors: Sadovsky E. , Matz D. , Diamant Y.Z. , Polishuk W.Z.
Published: September 2009

Leukocyte alkaline phosphatase (LAP) activity was studied in 50 women at delivery and in the newborn after delivery. The foüowing findings were observed: (1) the LAP activity of newborns is lower than that of the mothers; (2) significant decrease in the LAP activity has been observed in newborns on the 4th day after delivery; (3) there are no significant differences between newborns from normal and prolonged labor; (4) immediately after delivery the LAP scores of male newborns are lower than those of females, but 4 days later these scores were reversed, and (5) 4 days after delivery, the LAP scores do correlate to the weight of the newborn.
Non-Ionic Diffusion of Pentobarbital across Human Chorion Laeve
Authors: Schruefer J.J. , Haburchak D.R. , Garlid K.D. , Seeds, jr. A.E.
Published: September 2009

Diffusion of the weak organic acid, pentobarbital, across human chorion laeve in vitro shows an inverse correlation with pH, when corrected for extracellular space permeation by the concurrent measurement of membrane permeability to the lipid insoluble molecule, p-aminohippurate. The temperature dependence of pentobarbital diffusion at different pHs supports the concept that the additional net flux of solute at lower pH occurs by transcellular permeation by the non-ionized moiety, the observed increase corresponding roughly to the dissociation curve for pentobarbital.
Formation of Disaturated Lecithin through the Lysolecithin Pathway in the Lung of the Developing Rabbit
Authors: Hallman Mikko , Raivio Kari I.
Published: September 2009

The formation of disaturated lecithin in slices of developing rabbit lung was studied using 14C-CDP-choline, 3H-S-adenosylmethionine, and doubly labeled lecithin, lysolecithin and phosphatidylethanolamine as precursors. The labeling patterns suggest that some of the unsaturated lecithin becomes deacylated and subsequently reacylated to form disaturated surface-active lecithin. The rate of this pathway (lysolecithin ‘loop’) increases as a function of gestation and may contribute to the functional maturation of the lung.
Cortisol Treatment of Neonatal Rats: Effects on Enzymes in Kidney, Liver and Heart
Authors: Greengard Olga
Published: September 2009

Cortisol treatment of neonatal rats did not have permanent effects on the levels of 2–7 enzymes in heart, kidney, brain and liver, even though some exhibited abnormally high concentrations during the first 1 or 2 weeks. An injection of cortisol at birth evoked premature rises of glucose-6-phosphatase (G6P-ase) in kidney, of soluble and particulate aspartate aminotransferase (AAT) in kidney and heart and of soluble AAT in liver. These enzymes (with the exception of soluble AAT in the female) did not respond to cortisol in adult rats. The significance of the varying effects of cortisol is discussed in relation to previously studied developmental enzyme formations.
Age-Dependent Change in the Gel-Electrophoretic Pattern of Proteoglycans of Human Growth Cartilage
Authors: Stanescu V. , Maroteaux P. , Stanescu R. , Sobczak E.
Published: September 2009

The gel-electrophoretic pattern of dissociated proteoglycans was studied in 7 fetuses, 5 premature newborns, 4 term newborns, 5 infants and 5 children. The tibial growth cartilage was extracted with 4 M guanidinium chloride. After dialysis against 8 M urea at pH 7 the proteoglycans were obtained by ion chromatography in urea on DEAE cellulose and submitted to gel electrophoresis on polyacrylamide agarose gels. Gel electrophoresis of proteoglycans showed a different pattern in fetuses from that found in children. The change occurs in the first months of extrauterine life.
Metabolism of Natural and Synthetic Corticosteroids in Relation to their Effects on Mouse Fetuses
Authors: Wong M.D. , Thomson M.J. , Burton A.F.
Published: September 2009

14C-glucose uptake by mouse fetuses was reduced by doses of dexamethasone, 200 μg or more, which over 2 days caused fetal death. Uptake by strain C57B1/6J > A/J > SWV. Corticosterone or cortisol, 4 mg, caused neither reduced uptake nor fetal death. These differences occurred despite similar maternal hyperglycemia in all cases. Recovery of 3H-steroid after 15 min, total and unchanged steroid per gram fetal tissue was: corticosterone 1.7 and 0.3 %; dexamethasone 0.12 and 0.06 % of the dose. Rapid metabolism of corticosterone apparently prevents accumulation in fetal tissue sufficient to evoke a response under these conditions.
Transfer RNA and Aminoacyl Transfer RNA in Developing Rats
Authors: Liu Dai Kee , McKee Edward E. , Fritz Paul J.
Published: September 2009

The total transfer RNA (tRNA) level in the liver, kidney, skeletal muscle and heart muscle of developing rats was determined by purification using (3H)tRNA as an internal standard. Liver and kidney contained almost twice as much tRNA per gram tissue as heart and skeletal muscle. There were no apparent differences between the sexes. The aminoacylation capacities of six tRNA species (alanyl, aspartyl, leucyl, methionyl, phenylalanyl, and tryptophanyl) from rat liver were not different during three developmental stages (suckling, weanling and young adult), and there were also no differences noted between males and females. The in vivo percent aminoacylation of four tRNAs (aspartyl, leucyl, methionyl, and phenylalanyl) was lower during the newborn and suckling periods than in weanling and young adult rat livers. The tRNA of young adults was almost completely aminoacylated in vivo with the exception of alanyl-tRNA.
Factors Influencing the Lipolytic Response of Swine (Sus domesticus) Adipose Tissue: Ontogeny
Authors: Mersmann H.J. , Phinney G. , Brown L.J.
Published: September 2009

Swine adipose tissue was not responsive to glucagon at any age and only marginally to adrenocorticotropin (ACTH). The latter response could be greatly magnified and the sensitivity increased by addition of theophylline (Theo). The maximal lipolytic activity (MAX) obtained with ACTH plus Theo was minimal in the newborn, greatly increased in young animals, and reduced during the growing period; however, the sensitivity did not change. The MAX for Theo (plus low epinephrine) yielded a pattern similar to ACTH, but the sensitivity changed (most sensitive in younger animals). The MAX and sensitivity obtained with dibutyryl cyclic adenosine monophosphate were not appreciably changed during development.
Rib Anomalies in Myelodysplasia
Authors: McLennan James E.
Published: September 2009

An embryologic teratogenic mechanism is reconstructed by utilizing the distribution of anomalous ribs in children with lumbosacral myelomeningocele. This methodology may help to coalesce information from experimental models of teratogenesis and from descriptive human embryology. It provides an approach to deductive reasoning about human structural anomalies based on dynamic embryonic models of teratogenesis. Availability of a developmental time scale, based for example on the distribution of defective ribs, may be useful in the study of other teratogenic and developmental processes.
The Effects of Continuous Positive Airway Pressure on Lung Mechanics and Lung Volumes in the Neonate
Authors: Saunders R.A. , Milner A.D. , Hopkin I.E.
Published: September 2009

We have studied the effect of continuous positive airways pressure (CPAP) on the lung mechanics and thoracic gas volumes on 15 occasions in 12 healthy neonates. As expected, the thoracic gas volume rose and total pulmonary resistance fell. The dynamic compliance fell on all occasions. 43% of the applied pressure was transmitted through to the mediastinal structures.
Glucose Homeostasis in the Developing Rat
Authors: Watts C. , Gain K. , Sandin P.L.
Published: September 2009

Changes in blood glucose and plasma immunoreactive insulin (IRI) during the last 6 days of gestation of the fetal rat were studied. Blood glucose decreased from day 17 to day 19 to 43 mg/l00 ml and subsequently rose towards adult levels just before birth. The ratio of maternal to foetal blood glucose varied over this period. Plasma IRI increased to very high values at days 20 and 21 and subsequently fell just before birth. There was no correlation between the blood glucose and plasma IRI. The fetal pancreas increased 15-fold in size over this period and the percentage of insulin-containing Β-cells in the islets increased 12-fold.
Effect of ACTH on Blood-Free Fatty Acids, Glucose and on the Release of Free Fatty Acids from Subcutaneous Adipose Tissue in Various Groups of Newborns and Adults
Authors: Vízek K. , Rážová M. , Melichar V.
Published: September 2009

After administration of ACTH the blood concentration of FFA increases in full-term, premature and small-for-date newborn 1 day old, and in full-term and small-for-date newborns 7 days old. This effect does not appear in infants. Glucose concentration rises in all groups of newborns and in infants. In the in vitro study ACTH increases release of FFA and glycerol from the subcutaneous AT in the newborn period only.
Neonatal Hydrocortisone Administration: Effect on Cortisol and Glucose Levels
Authors: Price H.V. , Cowley Teresa , Cameron E.H.D.
Published: September 2009

Mean plasma cortisol levels were 314 and 553 μg/100ml 1 h after intramuscular hydrocortisone hemisuccinate 12.5 and 25 mg respectively, and significant levels were still present 10 h later. Half-life values in the period 2–8 h after injection range from 116 to 218 min with a mean of 147 min. Mean blood glucose increased by 12 mg/100 ml 2 h after injection.
Human Placental Amino Acid Oxidation
Authors: Robertson A.F. , Karp W.B. , Johnsson J.
Published: September 2009

Uniformly labeled L-alanine, L-aspartic acid, L-glutamic acid, and glycine were incubated with placental ‘mitochondria’ from normal pregnancies and the 14CO2 production measured. Significant oxidation of these amino acids occurred. By determining the endogenous level of these amino acids in placental ‘mitochondria’ and calculating the oxygen consumption due to their catabolism, it is likely that amino acid oxidation accounts for a negligible fraction of the energy needs of placentas from normal pregnancies.
Developmental and Compensatory Renal Growth in the Guinea Pig
Authors: Shirley D.G.
Published: September 2009

Postnatal renal growth in the guinea pig was studied in terms of cell size and number by estimation of renal nucleic acids. The renal content of RNA and DNA increased until about 3 months of age, when the kidneys themselves virtually ceased growing. By relating kidney weight to DNA content, it was found that average renal cell size reaches a maximum within 3–5 weeks of birth; after this renal growth is achieved purely by hyperplasia. When adult guinea pigs (3–4 months old) were subjected to unilateral nephrectomy, the remaining kidney underwent compensatory growth; after 6 weeks it was 42 % bigger than that of littermate control or sham-operated animals. Unilateral nephrectomy of guinea pigs 4–6 days old produced a greater response – a 59 % weight increase after 6 weeks. The renal weight increases were associated with similar increases in RNA content, but DNA content did not increase until the 2nd postoperative week, and then only by a relatively small amount. The increases in renal DNA content in newborn animals were not significantly different from those in adults. It is concluded that the degree of compensatory renal hyperplasia is the same in newborn and adult guinea pigs and that the extra response of neonates is due to cellular hypertrophy; thus the factor(s) controlling compensatory growth cannot act merely by regulating the rate of cell division.
Effect of Malnutrition and 6-Hydroxydopamine on the Early Postnatal Development of Noradrenaline and Serotonin Content in the Rat Brain
Authors: Hernández R.J.
Published: September 2009

Newborn rats were subjected to undernutrition and 6-hydroxydopamine (6-OHDA) treatment. Body and brain weight were affected more deeply during development in malnourished animals than in the 6-OHDA-treated ones. An increase in 5-hydroxytryptamine (5-HT) concentration in the anterior and posterior brain was observed at the age of 21 days in the malnourished group, suggesting changes in amine metabolism during nerve terminal maturation in the brain. In the 6-OHDA-treated group the 5-HT brain content was unchanged at the ages studied, which does not exclude the possibility of 5-HT metabolic modifications in the absence of noradrenergic pathways during postnatal development of the rat brain.
Diminished Response to Carbon Dioxide in Premature Infants
Authors: Krauss Alfred N. , Waldman Stephanie , Auld Peter A.M.
Published: September 2009

Reduced ventilatory response to CO2 (less than 50 cm3/min/mm Hg increase in minute ventilation) has been demonstrated in premature infants of 28–32 weeks postconceptional age. Diminished ventilatory response to CO2 may be due either to mechanical limitations on respiratory work or true loss of chemosensitivity. Although premature infants are neurologically immature they have been shown to have chemoreceptor activity for oxygen. They are also known to have stiff lungs and high total pulmonary resistance. The present study was undertaken to determine if mechanical or neurological factors limited CO2 response of premature infants. Adult patients have been shown to increase work during CO2 stimulation even though they do not increase minute ventilation as much as healthy subjects. Pulmonary work was therefore calculated from tracings of tidal volume and intraesophageal pressure during rebreathing of 5%CO2 – 40% O2 on 13 occasions in 12 infants. Evidence of CO2 sensitivity, demonstrated by increased respiratory work, was found in 5 of 7 infants who failed to increase minute volume in response to CO2. Two infants increased neither minute volume nor respiratory work, suggesting true absence of chemoreceptor activity. Both mechanical and neurological factors may limit the response to CO2 in premature infants.
Amniotic Fluid Volume in Pregnancies Complicated by Diabetes
Authors: Pass Robert , Christopher Craig , Hinkley Clark , Milstead Rachael , Bailey Penrhym , Cassady George
Published: September 2009

Amniotic fluid volume estimates were obtained in 37 diabetic women at 33½–38½ weeks of gestation. The technique employed, sodium aminohippurate (PAH) dilution, allowed estimation of both volume and Ê»turnover’. Hydramnios was common in the patients studied earlier in their third trimester; fetal macrosomia and increased severity of maternal disease was also evident in this group. Volumes comparable to those reported from normal patients were observed in the women studied later in their third trimester. Amniotic fluid volume appeared to be related to fetal growth with hydramnios accompanying macrosomia and oligohydramnios in fetal growth retardation. A positive correlation of PAH clearance and amniotic fluid volume was found.
Immunoreactive Insulin in Amniotic Fluid from Rh-Immunized Women
Authors: Vidnes Jostein , Finne Per H.
Published: September 2009

Immunoreactive insulin was measured in amniotic fluid from Rh-immunized women (anti-D antibody). The degree of immunization was expressed by the spectrophotometric index of the amniotic fluid and by the capillary hemoglobin concentration of the newborn. Higher levels of insulin were found in amniotic fluid from severely Rh-immunized mothers than from non-immunized, and a correlation between the degree of immunization and insulin concentration was indicated. To our knowledge this has not previously been demonstrated, and may justify some new hypotheses concerning the pathogenesis of the observed higher frequency of hyperinsulinism in babies of Rh-immunized mothers.
Cord and Maternal Serum Meperidine Concentrations and Clinical Status of the Infant
Authors: Rothberg Richard M. , Rieger Christian H.L. , Hill Jeffrey H. , Danielson John , Matadial Lennox
Published: September 2009

The possible relationship between the use of meperidine during labor and fetal or neonatal distress was investigated by correlating clinical parameters with maternal and cord serum concentrations of meperidine. The serum concentration of meperidine was determined by a radioimmunoassay which is 100-fold more sensitive than previously employed techniques and can detect as little as 0.02 nmol meperidine/ml. The incidence of fetal or neonatal depression following meperidine administration was higher (6 of 17 infants) than in a control group but no correlation between suppression and the route of meperidine administration or the serum meperidine concentrations at the time of delivery was found.
Body and Organ Growth in the Newborn Rat
Authors: Holloway, jr. William R. , Dollinger Mark J. , Denenberg Victor H.
Published: September 2009

Body and organ growth were described in rat pups 1 h and 10 days of age. Several organs (e.g., brain and pineal gland) exhibited significant growth in 1-hour-old but not in 10-day-old rats. Further, organs such as the testis and liver showed significant growth in 10-day-old but not 1-hour-old pups. 11 h of exposure to a warming oven, devoid of maternal and nutritional input, significantly influenced the body and organ growth of both newborn and 10-day-old pups. These data show that the first 12 h of life is an active period of growth for the rat.
Ultrastructure of the Cells in the Peripheral Blood of Human Embryos at Early Gestational Stages
Authors: Djaldetti M. , Goldman J.A. , Fishman P.
Published: September 2009

The presence of the different blood series in the peripheral blood of 10- to 18-week-old human embryos was followed by electron microscopy. It has been demonstrated that the earlier the stage of embryonic development, the more immature cells are found in the peripheral blood. This phenomenon may suggest migration of blood cell progenitors from earlier to more definitive sites of embryonic erythropoiesis.
Proteolytic Activity of Maternal Serum on Newborn IgD-Positive Lymphocytes
Authors: Tucci Pier Luigi , Biagioli Elena Cosenza , Panero Carlo
Published: September 2009

We studied the effect of maternal serum on the surface IgD of newborn lymphocytes in the presence of protease inhibitors (ε-aminocaproic acid and Trasylol). Contact with maternal serum caused a significant reduction (p < 0.000001) in the percentage of neonatal IgD-positive cells. The addition of either ε-aminocaproic acid or Trasylol significantly reduced this action of maternal serum (p < 0.00001 and p < 0.0001), without difference between the effects of the two inhibitors (p > 0.05). We suggest, therefore, that activity of maternal serum is due, at least in part, to proteolytic enzymes, such as plasmin. The relative role of plasminogen and α2-macroglobulin in the incapacity of the newborn serum to reduce the number of IgD-positive lymphocytes is discussed.
Dietary Influences on Fatty Acid Metabolism in the Liver of the Neonatal Lamb
Authors: Shand J.H. , Noble R.C. , Moore J.H.
Published: September 2009

A ‘protected’ polyunsaturated fatty acid supplement was fed to ewes during the last 8 weeks of pregnancy. The effect of this dietary supplement on the essential fatty acid composition of the liver phospholipids and associated changes in the liver Δ9- and Δ6-desaturase activities were investigated and compared with the effects of directly dosing the newborn lambs for 8 days with an unprotected polyunsaturated oil, maize oil. The maternal dietary supplement produced significant changes in the essential fatty acid composition of the neonatal lamb liver phospholipids. Although the liver Δ6-desaturase activity in these animals was also significantly higher than in the lambs from control ewes, the Δ9-desaturase was unaffected by maternal dietary supplementation. Direct dosing of the newborn lambs with maize oil failed to produce any significant changes either in the liver phospholipid fatty acid composition or in the Δ9- and Δ6-desaturase activities. These results are discussed in terms of the dietary control of liver desaturase enzyme systems.
Quantitative Analysis of Morphological Changes in Skeletal Muscle of the Rat after Hormone Administration
Authors: Kloosterboer H.J. , Stoker-De Vries S.A. , Hulstaert C.E. , Hommes F.A.
Published: September 2009

Thyroxine and cortisone acetate administration to rats of 4–7 days of age is not only accompanied by the induction of the muscle-specific enzyme, creatine kinase, but the hormones also induce morphological changes in the gastrocnemius during this period. Administration of thyroxine to these rats causes a splitting of myofibrils as shown by stereological measurements on electron micrographs. This splitting of myofibrils was not observed upon cortisone acetate administration and when both hormones were given simultaneously. It is suggested that cortisone acetate counteracts the effect of thyroxine. Both thyroxine and cortisone acetate increase the volume percentage taken by the mitochondria at 7 days of age. The effect of the simultaneous injection of both hormones is equal to the sum of the separate effects of these hormones. These changes in volume percentage of the mitochondria were compared with changes in a mitochondrial marker enzyme, i.e. citrate synthase. The difference between the morphological measurements and citrate synthase activity is due to a change in the specific activity of citrate synthase in the mitochondria.
Age-Dependent Pattern of Autonomic Heart Rate Control during Hypoxia in Fetal and Newborn Lambs
Authors: Walker A.M. , Cannata J.P. , Dowling M.H. , Ritchie B.C. , Maloney J.E.
Published: September 2009

Autonomic nervous control of heart rate (HR) during hypoxia was studied longitudinally using 9 chronically catheterized fetal lambs (109 day to term) and 10 newborn lambs (2–28 days old). Changes in heart rate (ΔHR) during hypoxia were age-dependent. Before 120 days of gestation ΔHR was insignificant, but between 120 days to term bradycardia occurred. The newborn response was marked tachycardia. Autonomic influences on HR were quantified using atropine and propranolol blockade. In fetal lambs, antagonistic increases in parasympathetic and sympathetic outflows were evident during hypoxia. In hypoxic lambs 120 days to term, net bradycaria reflected predominant parasympathetic cardio-deceleration; before 120 days of gestation both the parasympathetic and sympathetic outflows increased, but no net ΔHR occurred. In hypoxic newborn lambs, sympathetic and parasympathetic changes contributed synergistically to the net tachycardia. Thus the pattern of autonomic control of HR during hypoxia differs in fetal and newborn lambs. Changes in sympathetic and parasympathetic influences are antagonistic in the fetus, but synergistic in the newborn.
Influence of Progressive Starvation upon Brain and Adrenal Monoaminergic Activity in Developing Rats of Two Different Ages
Authors: Ismahan Gül , Parvez Hasan , Parvez Simone
Published: September 2009

Experiments show the influence of progressive starvation upon the synthetic and metabolic activity of monoaminergic function in the brain and the adrenal gland of young rats of two different ages. Brain and adrenal monoamine oxidase (MAO) showed a tendency to decline with the prolongation of the starvation interval. After 60 h of starvation, MAO activity was irreversibly decreased, even with 24 h of feeding, in the two age groups. Cerebral catechol-O-methyltransferase (COMT) activity was very slightly affected in response to the starvation in the older group, but the younger group showed an increased level of enzyme activity, and refeeding after 60 h of starvation of the young rats produced further increases. 60 h of starvation produced an increase in COMT activity of the adrenal gland of the older rats whereas the younger group did not show any marked change. Adrenal phenylethanolamine-N-methyltransferase (PNMT) declined after 24 and 48 h of starvation in the older rats, but the younger rats showed progressive increases after similar intervals of starvation. After 60 h of starvation, PNMT in the adrenal gland of the old rats increased significantly when compared to the control value, but the younger rats did not show any important change. Adrenal stores of adrenaline rose progressively up to 60 h of starvation in the old rats whereas the younger group responded in a contrary manner. Adrenal noradrenaline followed a similar pattern of evolution in both groups up to 60 h of starvation (when the results are expressed per milligram of adrenal protein), and refeeding had very little influence on the effects of starvation. The effects of starvation upon adrenal and cerebral MAO activity were verified with two different substrates. The results provide evidence that the metabolism of monoamines by oxidative deamination can be markedly affected by starvation, and this can be irreversible even after 24 h of feeding of starved rats. COMT activity augments when MAO activity declines.
Arginine Vasopressin during Gestation and Parturition in Sheep Fetus
Authors: Stark Raymond I. , Daniel Salha S. , Husain Kazim M. , James Stanley , Vande Wiele Raymond L.
Published: September 2009

The possible correlation between plasma arginine vasopressin (AVP) concentration and the processes leading to parturition was assessed in 11 chronically catheterized pregnant ewes. Samples of blood withdrawn intermittently during a 20-day period preceding labor and during parturition were analyzed for AVP by a specific radioimmunoassay, as well as for pH, PaCO2 and PaO2. Fetal AVP was 1.74 ± 1.55 pg/ml and maternal AVP 1.47 ± 0.74 pg/ml (mean ± SD). No preparturient rise in fetal vasopressin was noted, but levels increased progressively during labor to reach peak levels in cord blood (range 7.5–8,000 pg/ml). There was no consistent rise in maternal vasopressin during the same interval. A relationship between prolonged antepartum intrauterine asphyxia and increases in fetal vasopressin was noted. It is concluded that the markedly elevated levels of vasopressin observed in cord blood are the result of intrapartum ‘stress’, but are not related to the initiation of parturition.
Alterations in Creatinine Clearance during Respiratory Distress Syndrome
Authors: Tulassay T. , Ritvay J. , Bors Z. , Büky B.
Published: September 2009

Some renal parameters have been studied in newborns with respiratory distress syndrome (RDS). During the first 24 h, the serum creatinine level of the severe cases of RDS are significantly increased, decreasing gradually with improvement of the RDS and reaching normal values within 10 days. Blood urea nitrogen remained unchanged. In the milder cases of RDS, the serum creatinine also showed a slighter increase, which became normal within 4 days after birth. During the acute phase of RDS, there is a reversible impairment in the renal function, which correlates with the degree of hypoxia, hypercapnia and acidosis determined by the primary disease.
Superoxide Dismutase Activity in the Maternal and Cord Blood
Authors: Yoshioka Tamotsu , Sugiue Akira , Shimada Toshie , Utsumi Kozo
Published: September 2009

Superoxide dismutase (SOD) activity was measured in the maternal and cord blood by the modified method of Beauchamp and Fridovich, using a carbonate-buffered (pH 10.2) xanthine-xanthine oxidase system. No great differences between maternal and cord blood in erythrocyte SOD levels were observed, with the exception of whole blood; namely, washed RBC showed a SOD activity of a fairly high level, which was comparable to the activities of crude SOD, but showed no difference between them. In contrast, the SOD activity in the maternal whole blood was significantly lower than that in the cord blood. In measuring SOD activity, the serum factor has a great effect, and serum contains a substance that inhibits NBT reduction. Only one band of SOD has been detected which shows identical Rf values both in maternal and cord blood by polyacrylamide-gel electrophoresis.
Influence of Oxygen Tension and Cortisol Environment upon Growth and Cortisone Conversion to Cortisol by Cultured Human Fetal Lung Fibroblasts
Authors: Tanswell Keith , Smith Barry T.
Published: September 2009

Growth and conversion of cortisone to cortisol by human fetal lung fibroblasts in monolayer cell culture have been found to be sensitive to steady-state oxygen concentrations or to acute oxidant stresses. Oxygen-dependent differences are significantly modified by pre-incubation with cortisol. We speculate that cortisol may have an oxygen-protective role, and that the induction of increased conversion of cortisone to cortisol with an increase in oxygen tension, such as that observed at delivery, may be of significance in the prematurely born infant with the respiratory distress syndrome.
Influence of Hypo- and Hyperthyroidism on Noradrenaline Metabolism in Brown Adipose Tissue of the Developing Rat
Authors: Gripois D. , Klein C. , Valens M.
Published: September 2009

We studied the noradrenaline content, and monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT) activities in brown adipose tissue (BAT) of normal, hypothyroid, and hyperthyroid developing rat. In the newborn, thyroid hormones are necessary for the increase in noradrenaline content which occurs between 0 and 5 days. Hypothyroidism increases both MAO and COMT activities. Hyperthyroidism decreases MAO activity but not noradrenaline content or COMT activity. In the full-term fetus, hypothyroidism decreases noradrenaline content as in the newborn, and also decreases MAO and COMT activities. It is suggested that thyroid hormones could modulate BAT nonshivering thermogenesis by regulating the level of noradrenaline, the direct mediator of heat production.
Uridine Phosphorylase Activity during Postnatal Development of the Rat Heart
Authors: Frelin Christian , Bonnard Odile
Published: September 2009

Uridine phosphorylase activity was assayed in heart extracts from rats of different postnatal age. Activity was low at birth, increased to a maximum at 8–14 days of postnatal development and then decreased to a low adult level. The switch from cellular hyperplasia to hypertrophy determined by the ratio proteins/DNA occurred at day 18 of development. It is suggested that the activation of uridine phosphorylase activity during the early life of the rat may be a critical element of the onset of hypertrophy.
Central Venous Pressure in Preterm Infants
Authors: Siassi Bijan , Wu Paul Y.K. , Li Raymond K. , Mondanlou Houchang
Published: September 2009

Right atrial A-wave, mean and inspiratory pressures were measured serially every 6 h in 36 preterm infants – 24 healthy and 12 with respiratory distress syndrome (RDS) – from the 2nd until 24th h of age. In healthy preterm infants, the right atrial A-wave averaged + 4.91 mm Hg with a range of + 2 and + 8 mm Hg and the right atrial mean pressure averaged + 1.62 with a range of -3 to + 4 mm Hg. Preterm infants developing RDS had significantly lower right atrial pressure (RAP) during the first 6 h of life than healthy preterm infants. RAP in preterm infants with RDS subsequently increased to normal range. RAP did not have any correlation with either birth weight or gestational age.
Cord Serum AFP and the Immunological Status of the Mother: a Lack of Correlation
Authors: Bernal J.E. , Wagstaff T.I.
Published: September 2009

Cord serum from 139 newborns was analysed for Α-fetoprotein and immunoglobulin G and the results correlated with the obstetric records of the mothers. No significant correlation was found in comparing either Α-fetoprotein or immunoglobulin G levels with the previous obstetric experiences of the mothers. A previously reported sex difference of Α-fetoprotein levels at birth was not found in this study. These results are discussed in the light of the possible immunosuppressive effects of Α-fetoprotein.
Surface Elastic Properties of Surfactant from the Lungs of Neonatal Pigs
Authors: Meban C.
Published: September 2009

The elasticity of surfactant films from the lungs of neonatal pigs was measured using a torsion elastometer. It was found that the elastic modulus of the films increased markedly as the surfactant concentration was raised. Increasing the temperature stepwise over the range 25–41 °C produced a decrease in the elastic modulus. In contrast, altering the pH of the subphase over the range 7.1–7.7 had no significant effect on film elasticity. The influence of surfactant films on pulmonary compliance is discussed.
Transport of 3H-TRH from Plasma to Rat Milk: Accumulation and Slow Degradation in Milk and Presence of Unaltered Hormone in Gastric Content of Pups
Authors: Štrbák V. , Alexandrová M. , Macho L. , Ponec J.
Published: September 2009

10μCi 3H-TRH was administered intravenously to lactating rats 14 days after delivery. The total radioactivity of plasma and milk equalized about 25 min after injection and increased continually in milk during the 2-hour study. The percentage of activity bound to specific TRH antibody was the same in extracts of plasma and milk (about 60% of standard binding) throughout the experiment. Besides milk, the radioactivity was also accumulated in pituitary, thyroid, kidney and liver; the tissue:plasma ratio being 2:4 2 h after injection. The presence of 3H-TRH in milk extracts was also confirmed by paper chromatography (butanolacetic acid-water-ethylacetate, 1:1:1:1) and electrophoresis (in pyridine acetate buffer, pH 5.8). TRH-degrading activity, representing about one fifth of that in plasma, was found in rat milk in vitro by means of paper chromatography and electrophoresis. The gastric contents of suckling pups after injection of 3H-TRH were also analyzed. The total radioactivity increased from 30 to 60 min after the injection. The percentage reacting with the specific TRH antibody in extracts of gastric contents was the same as that in plasma and milk and did not change throughout the 2 h of experiment. Our results show one-way transport of TRH from plasma to milk, low TRH-degrading activity of milk and passage of unaltered neurohormone from plasma to milk and stomach of suckling. The gastric content does not have a deteriorating effect on TRH. We suppose that the presence of accumulated TRH in maternal milk could be of some biological significance in suckling, in which the plasma TRH-degrading system is lacking.
Continuous Measurement of Scalp Tissue Oxygen Tension and Carotid Arterial Oxygen Tension in the Fetal Lamb
Authors: Aarnoudse J.G. , Oeseburg B. , Kwant G. , Huisjes H.J. , Zijlstra W.G.
Published: September 2009

Scalp tissue PO2 carotid arterial PO2 and fetal heart rate were continuously measured in the anaesthetized fetal lamb in utero while variations in oxygen supply were brought about. In some experiments the transcutaneously measured fetal scalp PO2 was recorded in addition. Scalp tissue PO2 was measured using a specially designed miniature needle-type oxygen electrode, incorporated in an easily applicable spiral scalp electrode as commonly used for fetal heart rate monitoring. The measurements showed that fetal carotid arterial hypoxaemia is always nearly immediately followed by fetal scalp tissue hypoxia, and that the recovery of scalp tissue PO2 after a hypoxic period has a remarkably varying time course. Fetal heart rate usually decreased during hypoxia, but in some instances it did not change or even increased, demonstrating that heart rate is not always a reliable indicator of fetal hypoxia. PO2 values obtained with the transcutaneous method were higher than those with the needle electrode, because of the effect of the heating system of the transcutaneous electrode on tissue blood flow and haemoglobin oxygen affinity. It would seem that during hypoxaemia the decrease in scalp tissue PO2 is possibly the combined result of the fall in arterial PO2 and a concomitant decrease in blood flow through the skin.
Glycosylation and Acetylation of Hemoglobin in Infants of Normal and Diabetic Mothers
Authors: Schwartz H.C. , Widness J. , Thompson D. , Tsuboi K.K. , Oh W. , Schwartz R.
Published: September 2009

The minor hemoglobins, which are formed post-translationally by acetylation or glycosylation, were studied in cord blood from 34 newborn infants. There were 9 normal infants, 8 infants of gestational (chemical) diabetics, and 17 infants of insulin-dependent diabetics. Among these groups, no significant differences in the acetylated fetal (FI) or other minor hemoglobin fractions were found by either isoelectric focusing in polyacrylamide gels or chromatography on DEAE-cellulose columns. These studies emphasize the technical limitations of detecting small amounts of glycosylated hemoglobin in newborns. The biological implications of the acetylated fetal hemoglobin fraction remain obscure.