bluuebunny/crossref_metadata_2025_split huggingface dataset:
The development of adopted children after institutional care: a follow‐up study
Authors: Vorria Panayiota , Papaligoura Zaira , Sarafidou Jasmin , Kopakaki Maria , Dunn Judy , Van IJzendoorn Marinus H. , Kontopoulou Antigoni 
Published: October 2006

Background:  Research suggests that institutional care has long‐lasting effects on children. However, no study has longitudinally studied infants in an institution and their subsequent development at age four.Methods:  Sixty‐one adopted children aged four years who had spent their first two years of life in an institution were compared to 39 children reared in their own two‐parent families. Cognitive development, security of attachment, shyness, children's emotional understanding and behavioural problems were examined in both groups. Parental health and stress were also assessedResults:  At four years adopted children still had lower scores on cognitive development, were less secure, and less able to understand emotions than family‐reared children. Children with a secure attachment type in infancy were found to be less secure at age four, compared with those who were classified in infancy as having an insecure attachment type. Their physical development had recovered, they were less shy, had no behavioural problems and no problems in the relationship with their teacher.Conclusions:  Early residential group care has long‐lasting effects on important socio‐emotional and cognitive aspects of preschool children's development.
The impact of alcohol‐specific rules, parental norms about early drinking and parental alcohol use on adolescents’ drinking behavior
Authors: Van Der Vorst Haske , Engels Rutger C.M.E. , Meeus Wim , Deković Maja 
Published: October 2006

Background:  The present study explores the role of having rules about alcohol, parental norms about early alcohol use, and parental alcohol use in the development of adolescents’ drinking behavior. It is assumed that parental norms and alcohol use affect the rules parents have about alcohol, which in turn prevents alcohol use by adolescent children.Methods:  Longitudinal data collected from 416 families consisting of both parents and two adolescents (aged 13 to 16 years) were used for the analyses.Results:  Results of structural equation modeling show that having clear rules decreases the likelihood of drinking in adolescence. However, longitudinally alcohol‐specific rules have only an indirect effect on adolescents’ alcohol use, namely through earlier drinking. Analyses focusing on explaining the onset of drinking revealed that having strict rules was related to the postponement of drinking initiation of older and younger adolescents. Further, parental norms about adolescents’ early drinking and parental alcohol use were associated with having alcohol‐specific rules. Parental norms were also related to adolescents’ alcohol use.Conclusions:  The current study is one of the first using a full family design to provide insight into the role of alcohol‐specific rules on adolescents’ drinking. It was shown that having strict rules is related to postponement of drinking, and that having alcohol‐specific rules depends on other factors, thus underlining the complexity of the influence of parenting on the development of adolescents’ alcohol use.
entaaification of Atrial Natriuretic Factor Receptor of Neuroblastoma N4TG1 Cells: Binding Characteristics and Photoaffinity Labeling
Authors: Pandey Kailash N. , Misono Kunio S. , Takayanagi Ryoichi , Pavlou Spyros N. , Inagami Tadashi 
Published: October 2006

AbstractsWe have found specific receptors for atrial natriuretic factor (ANF) in cultured neuroblastoma cells (N4TG1) of peripheral ganglionic origin. Scatchard analysis of the displacement binding revealed noninteracting, singleclass binding sites with a KD of 1 ± 1010M and a density (Bmax) of 110,000–150,000 sites/cell. The cell‐bound 125I‐ANF was displaced by unlabeled ANF in a dose‐dependent manner. Hormones unrelated to ANF such as angiotensins, adrenocorticotropic hormone, or arginine vasopressin were ineffective in displacing the cell‐bound radioactivity. Using azidobenzoyl‐125I‐ANF as a photoaffinity ligand, an ANF receptor with an apparent Mr of 138,000 was identified by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis and autoradiography. The addition of unlabeled ANF (1 μM) to the incubation medium completely abolished the labeling of this protein band, but atriopeptin I (1 μM) or angiotensins I, II, and III (each 1 μM) were not effective in inhibiting the affinity labeling. The treatment of the neuroblastoma cells with ANF stimulated intracellular cyclic GMP levels in a dose‐dependent manner with an EC50 of 5 nM. ANF(1 ± 107M) stimulated cyclic GMP accumulation in <5 min by 30‐fold as compared to the controls.
Characterization of the Binding of [3H]SR 95531, a GABAA Antagonist, to Rat Brain Membranes
Authors: Heaulme Michel , Chambon Jean‐Pierre , Leyris Roger , Wermuth Camille G. , Biziere Kathleen 
Published: October 2006

AbstractA synthetic derivative of γ‐aminobutyric acid (GABA), SR 95531 [2‐(3′‐carboxy‐2′‐propyl)‐3‐amino‐6‐p‐methoxyphenylpyridazinium bromide], has recently been reported, on the basis of biochemical and in vivo microion‐tophoretic studies, to be a potent, selective, competitive, and reversible GABAA antagonist. In the present study, the binding of [3H]SR 95531 to washed, frozen, and thawed rat brain membranes was characterized. Specific binding was linear with tissue concentrations, had a pH optimum at neutrality, and was maximal at 4°C after 30 min of incubation. Pretreatment of the membranes with Triton X‐100 resulted in a 50% decrease of specific binding. Addition of iodide, thiocyanate, or nitrate to the incubation mixture decreased the affinity of [3H]SR 95531 for its binding site; Na+ had no effect. Subcellular fractionation showed that 74% of the P2 binding was in synaptosomes; 31% of the total homogenate binding was in P2 and 50% in P3. The binding of [3H]SR 95531 was saturable; Scatchard analysis of the saturation isotherm revealed two apparent populations of binding sites (KD of 6.34 nM and Bmax of 0.19 pmol/mg of protein; KD of 32 nM and Bmax of 0.81 pmol/mg of protein). The binding of [3H]SR 95531 was reversible, and association and dissociation kinetics confirmed the existence of two binding sites. Only GABAA ligands were effective displacers of [3H]SR 95531. GABAA antagonists were relatively more potent in displacing [3H]SR 95531 than [3H]GABA; the inverse was true for GABAA agonists. There were marked regional differences in the distribution of binding sites: hippocampus = cerebral cortex > thalamus = olfactory bulb = hypothala‐mus = amygdala = striatum > pons‐medulla and cerebellum. The surprisingly low density of binding sites in the cerebellum was owing to a marked reduction of Bmax values at both the high‐ and the low‐affinity binding sites. In conclusion, the present results demonstrate specific, high‐affinity, saturable, and reversible binding of [3H]SR 95531 to rat brain membranes and strongly suggest that this radioligand labels the GABAA receptor site in its antagonist conformation.
Specific Binding of [3H]Pyrilamine to Histamine H1 Receptors in Guinea Pig Brain In Vivo: Determination of Binding Parameters by a Kinetic Four‐Compartment Model
Authors: Yanai Kazuhiko , Yagi Naoto , Watanabe Takehiko , Itoh Masatosi , Ishiwata Kiichi , Ido Tatsuo , Matsuzawa Taiju 
Published: October 2006

AbstractThe binding of [3H]pyrilamine, a selective ligand of histamine H1 receptors, to guinea pig brain in vivo was compared with its binding to a brain homogenate. The pharmacological properties (regional distribution, saturability, and stereoselectivity) of the [3H]pyrilamine binding in vivo were similar to those of the in vitro binding to brain homogenate. A dynamic four‐compartment model was proposed for the analysis of the kinetics of [3H]pyrilamine binding in vivo. The receptor constants in vivo were determined by a computer‐fitting method after correcting the radioactivity of arterial plasma and brain for the presence of radioactive metabolites. The in vivo association and dissociation were 213 and 42 times, respectively, slower than those of in vitro binding at 37°C. A possible mechanism for slow association and dissociation in vivo is discussed.
Analysis of Carnosine, Homocarnosine, and Other Histidyl Derivatives in Rat Brain
Authors: O'Dowd John J. , Cairns Maria T. , Trainor Maxine , Robins David J. , Miller David J. 
Published: October 2006

AbstractIsocratic reverse‐phase analytical HPLC has been used to examine naturally occurring imidazoles of rat brain. Elution of brain extracts with a phosphate buffer mobile phase from columns packed with Hypersil ODS (5 μm) resulted in good separation of the well‐documented brain imidazole‐containing dipeptides carnosine and homocarnosine. Measured concentrations corresponded to published values. Several further peaks observed had properties consistent with those of N‐acetyl derivatives of compounds related to carnosine and homocarnosine. N‐Acetyl forms not commercially available were prepared and their identities verified by nuclear magnetic resonance spectroscopy. A number of these had chromatographic properties identical to those of compounds in brain extracts. Fractions corresponding to some of the peaks were examined using staining systems specific for certain chemical features and compared with results obtained for commercial or synthetic standards. The results of these tests supported the chromatographic data. Thus, chromatographic and microchemical evidence is presented for the existence of N‐acetyl forms of histidine, 1‐methylhistidine, carnosine, anserine, and homocarnosine in rat brain.
Neurofilament Proteins Are Distributed in a Diminishing Proximodistal Gradient Along Rat Sciatic Nerve
Authors: Schlaepfer William W. , Bruce Jennifer 
Published: October 2006

AbstractNeurofilament (NF) proteins are distributed in a diminishing proximodistal gradient along rat sciatic nerve when compared with total noncollagen or other proteins in nerve. About a twofold decline of NF proteins can be detected by quantitating nerve proteins that have been separated by gel electrophoresis. A similar decrease of immunoreactivity to each NF subunit is seen in distal nerve segments when noncollagen nerve proteins are immunoblot ed. Parallel decreases occur in all three NF proteins, thereby maintaining neurofilament subunit stoichiometry along the neuraxis. The same NF gradient can be detected when the NF contents in nerve branches to the gluteus and gastrocnemius muscles are compared with each other and with those in nerve segments taken from the same proximodistal levels of the parent sciatic nerve. The gradient of NF proteins increases during postnatal development and is readily detected by postnatal day 16. During the same period of development, the heavy NF subunit appears for the first time and is rapidly incorporated throughout the sciatic nerve. Hence, the NF gradient becomes manifest during the development and maturation of the adult form of the axonal cytoskeleton. The basis for the proximodistal gradient of NF proteins in peripheral nerve is presently unknown. The extent of the gradient cannot be accounted for on the basis of diminishing numbers of nerve fibers or increasing amounts of other nerve proteins, e.g., collagen, in distal nerve. An alternative interpretation is that the gradient reflects a low level of NF protein turnover during axonal transport.
Reflex Splanchnic Nerve Stimulation Increases Levels of Carboxypeptidase E mRNA and Enzymatic Activity in the Rat Adrenal Medulla
Authors: Flicker Lloyd D. , Rigual Ricardo J. , Diliberto Emanuel J. , Viveros O. Humberto 
Published: October 2006

AbstractCarboxypeptidase E (CPE; EC 3.4.17.10) is a carboxypeptidase B‐like enzyme involved with the biosynthesis of numerous peptide hormones and neurotransmitters, including the enkephalins. Reflex splanchnic stimulation of the rat adrenal medulla, which has previously been found to substantially increase enkephalin mRNA and enkephalin peptide levels, was examined for an influence on CPE mRNA and enzymatic activity. Several hours after insulin‐induced reflex splanchnic stimulation, the levels of CPE activity in rat adrenal medulla are reduced to 40–60% of control. CPE activity returns to the control level 2 days after the treatment and then continues to increase, reaching ˜200% of control 1 week after the treatment. The time course of the changes in CPE activity is different from those of the changes in epinephrine levels and the previously reported changes in enkephalin peptide levels. CPE mRNA is also influenced by the insulin shock, with levels increasing to 155% of the control level after 6 h and 170% after 2 days. The time course of the change in CPE mRNA levels is similar to that previously found for proenkephalin mRNA. However, the magnitude of the change is much different: Proenkephalin mRNA has been reported to increase by 1,600%. The changes in CPE mRNA and enzymatic activity are consistent with the proposal that CPE is not a rate‐limiting enzyme in the biosynthesis of enkephalin.
High Level of Expression of the Myelin Protein P0 in Chinese Hamster Ovary Cells
Authors: Filbin Marie T. , Tennekoon Gihan I. 
Published: October 2006

AbstractThe major PNS myelin protein, P0, has been expressed in Chinese hamster ovary cells by transfection with a plasmid containing the P0‐cDNA. The expression of P0 at both the RNA and the protein level was greatly increased, without detriment to the cell, by the dihydrofolate reductase/methotrexate strategy of gene amplification. The P0 expressed by these cells was glycosylated (containing approximately equal amounts of the complex and high‐mannose type glycoproteins) and reached the plasma membrane. This system is suitable not only for addressing the function of P0 directly, but is also applicable to any protein of which an abundance is needed.
Glutamate‐Dependent Active‐Site Labeling of Brain Glutamate Decarboxylase
Authors: Martin David L. , Wu Susan J. , Martin Sandra Bloom 
Published: October 2006

AbstractA major regulatory feature of brain glutamate decarboxylase (GAD) is a cyclic reaction that controls the relative amounts of holoenzyme and apoenzyme [active and inactive GAD with and without bound pyridoxal 5′‐phosphate (pyridoxal‐P, the cofactor), respectively]. Previous studies have indicated that progression of the enzyme around the cycle should be stimulated strongly by the substrate, glutamate. To test this prediction, the effect of glutamate on the incorporation of pyridoxal‐P into rat‐brain GAD was studied by incubating GAD with [32P]pyridoxal‐P, followed by reduction with NaBH4 to link irreversibly the cofactor to the enzyme. Adding glutamate to the reaction mixture strongly stimulated labeling of GAD, as expected. 4‐Deoxypyridoxine 5′‐phosphate (deoxypyridoxine‐P), a close structural analogue of pyridoxal‐P, was a competitive inhibitor of the activation of glutamate apodecarboxylase by pyridoxal‐P (K1= 0.27 μM) and strongly inhibited glutamate‐dependent labeling of GAD. Analysis of labeled GAD by sodium dodecyl sulfate (SDS)‐polyacrylamide gel electrophoresis showed two labeled proteins with apparent molecular masses of 59 and 63 kDa. Both proteins could be purified by immunoaffinity chromatography on a column prepared with a monoclonal antibody to GAD, and both were labeled in a glutamate‐dependent, deoxypyridoxine‐P‐sensitive manner, indicating that both were GAD. Three peaks of GAD activity (termed peaks I, II, and III) were separated by chromatography on phenyl‐Sepharose, labeled with [32P]pyridoxal‐P, purified by immunoaffinity chromatography, and analyzed by SDS‐polyacrylamide gel electrophoresis. Peak I contained only the 59‐kDa labeled protein. Peaks II and III contained the both the 59‐ and 63‐kDa proteins, but in differing proportions. The 59‐kDa protein predominated in peak II and the 63‐kDa protein in peak III. A similar pattern of proteins was observed with each of the immunoaffinity‐purified peaks of enzyme activity on silver‐stained SDS‐polyacrylamide gels. 32P‐Labeled peak‐I GAD and the 59‐ and 63‐kDa bands of peak III were each exhaustively digested with chymotrypsin and chromatographed on sulfopropyl and reverse‐phase HPLC columns. The elution profiles of the digests were very similar, and each contained a single major peak of radioactivity, as would be expected if the same active‐site peptide was labeled. The strong stimulation by glutamate of labeling with [32P]pyridoxal‐P is entirely consistent with the mechanism of GAD inferred from previous studies and provides further evidence for the glutamate‐dependent cyclic interconversion of the apo‐ and holoenzymes.
Dephosphorylation of r Factor by Protein Phosphatase 2A in Synaptosomal Cytosol Fractions, and Inhibition by Aluminum
Authors: Yamamoto Hideyuki , Saitoh Yoshiki , Yasugawa Setsuko , Miyamoto Eishichi 
Published: October 2006

AbstractWhen the synaptosomal cytosol fraction from rat brain was chromatographed on a DEAE‐cellulose column and assayed for protein phosphatases for τ factor and histone H1, two peaks of activities, termed peak 1 (major) and peak 2 (minor), were separated. Each peak was in a single form on Sephacryl S‐300 column chromatography. Both peaks 1 and 2 dephosphorylated τ factor phosphorylated by Ca2+/calmodulin‐dependent protein kinase II and the catalytic subunit of cyclic AMP‐dependent protein kinase. The Km values were in the range of 0.42–0.84 μM for τ factor. There were no differences in kinetic properties of dephosphorylation between the substrates phosphorylated by the two kinases. The phosphatase activities did not depend on Ca2+, Mn2+, and Mg2+. Immunoprecipitation and immunoblotting analysis using polyclonal antibodies to the catalytic subunit of brain protein phosphatase 2A revealed that both protein phosphatases are the holoenzymic forms of protein phosphatase 2A. Aluminum chloride inhibited the activities of both peaks 1 and 2 with IC50 values of 40–60 μM. These results suggest that dephosphorylation of r factor in presynaptic nerve terminals is controlled mainly by protein phosphatase 2A and that the neurotoxic effect of aluminum seems to be related mostly to inhibition of dephosphorylation of τ factor
Rapid Isolation of Metabolically Active Mitochondria from Rat Brain and Subregions Using Percoll Density Gradient Centrifugation
Authors: Sims Neil R. 
Published: October 2006

AbstractTwo procedures are described for isolating free (nonsynaptosomal) mitochondria from rat brain. Both procedures employ a discontinuous Percoll gradient and yield well coupled mitochondria which exhibit high rates of respiratory activity and contain little residual contamination by synaptosomes or myelin. The procedures are considerably more rapid than methods described previously for the isolation of brain mitochondria and do not require an ultracentrifuge or swing‐out rotor. The first method separates mitochondria by gradient centrifugation from a P2 (crude mitochondrial) fraction and is likely to be widely applicable for studies in which at least 500 mg of tissue are available as starting material. In the second method, the unfractionated homogenate is subjected directly to gradient centrifugation. This method requires the preparation of more gradients (per gram of tissue) than the first method and yields a subcellular fraction with slightly more synaptosomal contamination. However, this second procedure is more rapid, requires less manipulation of the tissue, and is suitable for obtaining mitochondria with well preserved metabolic characteristics from subregions of single rat brains.
Lithium Chloride Inhibits the Phosphorylation of Newly Synthesized Neurofilament Protein, NF‐M, in Cultured Chick Sensory Neurons
Authors: Bennett Gudrun S. , Laskowska Danuta , DiLullo Camille 
Published: October 2006

Abstract: The middle and high molecular weight members of the neurofilament triplet, NF‐M and NF‐H, undergo extensive posttranslational polyphosphorylation, a process requiring 24 h or more for completion. We have investigated ways of perturbing this process in intact cells and have found that phosphorylation of newly synthesized NF‐M in cultured chick sensory neurons is inhibited by Li+. [35S]Methionine pulse‐chase experiments were carried out with pure neuronal cultures, and the phosphorylation of newly synthesized NF‐M was monitored by following the accompanying change, with chase time, in apparent size and charge of the polypeptide. Addition of LiCl to the medium inhibited this mobility shift in a dose‐dependent manner over concentrations between 2 and 25 mM. Incorporation of 32P into NF‐M, as well as NF‐H, was also inhibited, whereas incorporation into the low molecular weight neurofilament protein, β‐tubulin, and total protein was unaffected. Protein synthesis was not altered.Exposure to 25 mM LiCl for up to 72 h was not toxic, and the inhibition of NF‐M phosphorylation was completely reversible. When 25 mM Li+ was added after NF‐M had become partially phosphorylated, further progression was blocked, but there was no net dephosphorylation or degradation of NF‐M. Additional experiments suggest that this action of Li+ is probably not due to effects on second messenger levels or to effects on tubulin metabolism and assembly state presented in our accompanying article, but rather to interference by Li+ itself, with the phosphorylation of NF‐M and NF‐H by specific neurofilament kinase(s).
Characterization of Two Chromaffin Cell Populations Isolated from Bovine Adrenal Medulla
Authors: Moro M. A. , Garcia A. G. , Langley O. K. 
Published: October 2006

AbstractCultures of chromaffin cells isolated from the bovine adrenal medulla have been extremely useful for investigating secretory mechanisms, but such cultures used up to the present time represent mixed populations of adrenergic and nor‐adrenergic cells. This report describes how, with slight modifications to standard procedures, two separate chromaffin cell populations may be separated from bovine adrenal medullae. These two cell fractions have been characterized by biochemical, immunocytochemical, and morphological techniques as enriched populations of adrenergic or noradrenergic cells, respectively. The adrenergic cell‐enriched fraction consists of >90% adrenergic cells, whereas the noradrenergic cell‐enriched fraction contains >60% noradrenergic cells. We also demonstrate that these cells may be cultured with their secretory machinery intact: analysis of secreted catecholamines from nicotine‐ or high K+ concentration‐stimulated cells cultured from each fraction confirms that adrenaline is the major catecholamine secreted by one fraction, whereas noradrenaline is mainly secreted by the other.