bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phase Formation and Properties in the System Bi2O3:2CoO1+x:Nb2O5
Authors: Vanderah Terrell A. , Siegrist Theo , Lufaso Michael W. , Yeager Margaret C. , Roth Robert S. , Nino Juan C. , Yates Samantha 
Published: October 2006

AbstractSubsolidus phase relations have been determined for the Bi–Co–Nb–O system in air (750–925 °C). Ternary compound formation was limited to pyrochlore (A2B2O6O′), which formed a substantial solid solution region at Bi‐deficient stoichiometries (relative to Bi2Co2/3Nb4/3O7) suggesting that about 8 to 25 % of the A sites are occupied by Co. X‐ray powder diffraction data confirmed that all Bi–Co–Nb–O pyrochlores exhibit displacive behavior. A structural refinement of the pyrochlore Bi1.56Co0.96Nb1.48O7 using single‐crystal X‐ray diffraction data is reported with the A and O′ atoms displaced (0.34 Å and 0.45 Å, respectively) from ideal positions to96g sites and 32e sites, respectively [Fd3$\bar {S}$m (#227), a = 10.551(1) Å]. The displacive structural behavior is similar to that found in analogous Bi–M–Nb–O pyrochlores (M = Zn, Fe, Mn). Bi–Co–Nb–O pyrochlores exhibited overall paramagnetic behavior with negative Curie–Weiss temperature intercepts indicating weak antiferromagnetic interactions. At 250 K and 1 MHz the relative dielectric permittivity of the pyrochlore 0.4400:0.2100:0.3500 Bi2O3:2CoO1+x:Nb2O5 was ca. 115 with tan δ = 0.06; however, at lower frequencies the sample was conductive. Low‐temperature dielectric relaxation such as that observed for Bi1.5Zn0.92Nb1.5O6.92 and other bismuth‐based pyrochlores was not observed. Consideration of bond lengths, effective magnetic moments, and dielectric properties suggests that the average oxidation state of Co in the pyrochlore phases is close to but slightly higher than 2.0. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
siRNA‐mediated type 1 insulin‐like growth factor receptor silencing induces chemosensitization of a human liver cancer cell line with mutant P53
Authors: Niu Jian , Xu Zonghua , Li Xiang‐nong , Han Zeguang 
Published: October 2006

AbstractOverexpression of type 1 insulin‐like growth factor receptor (IGF1R) contributes to the progression and metastasis of liver cancer, implying that IGF1R gene is a suitable target of RNA interference (RNAi) for liver cancer therapy. To investigate the possible regulation of IGF1R by P53, we examined the level of IGF1R expression in liver cancer cell lines in response to adriamycin. Levels of IGF1R mRNA and protein in cell lines with wild‐type P53 decreased dramatically after P53 induction, but no such reduction of IGF1R was observed in cell lines with mutated P53. Inhibition of wild‐type P53 in HEPG2 cells by small interfering RNA (siRNA) significantly upregulated the expression of IGF1R. IGF1R inhibition by siRNA in Huh7 cells with mutated P53 significantly depressed cell proliferation. To investigate the sensitivity of cancer cells to adriamycin after inhibition of IGF1R, we depressed IGF1R expression using siRNA, and then added adriamycin at an IC50 dose. After a further 48 h incubation with adriamycin, proliferation was significantly depressed in the cells treated with siRNA targeting IGF1R, in comparison with siRNA targeting scramble. Furthermore, both TUNEL and pro‐caspase‐3 expression assay showed a significant increase in apoptosis after combined treatment with adriamycin and siRNA targeting IGF1R. Our results demonstrate that IGF1R is downregulated by P53, and that siRNA targeting of IGF1R increases liver cancer cells sensitivity to adriamycin and promotes apoptosis. siRNA targeting of IGF1R could be potentially useful for increasing sensitivity to anti‐cancer drugs, especially in drug‐resistant cells with mutated P53.
A change in N‐terminal pro‐brain natriuretic peptide is predictive of outcome in patients with advanced heart failure
Authors: Gardner Roy S. , Chong Kwok S. , Morton James J. , McDonagh Theresa A. 
Published: October 2006

AbstractBackground:The prognosis of chronic heart failure has improved with modern medical therapy. However, identifying those patients who fail to respond to such therapy and therefore those who remain at high risk is notoriously difficult. The B‐type natriuretic peptides are established independent predictors of prognosis in CHF. However, the relevance of a change in NT‐proBNP concentration over time in advanced heart failure is unknown.Methods:We prospectively studied 133 patients with advanced CHF referred for consideration of cardiac transplantation. Plasma for NT‐proBNP analysis was sampled at baseline and a median of 4months later in the 112 patients surviving without cardiac transplantation. Patients were followed up for a median of 1003days.Results:The primary endpoint of all‐cause mortality occurred in 30 (26.8%) patients. Those subjects who had the highest NT‐proBNP concentration at 4months were at the greatest risk of death (log rank statistic=10.4, p=0.001). On Cox regression analysis, both a NT‐proBNP concentration above the median and an absolute increase in NT‐proBNP were independent predictors of mortality (χ2=53, p<0.0001 and χ2=17.3, p<0.0001, respectively).Conclusion:A single NT‐proBNP concentration above the median and a change in NT‐proBNP concentration over a 4‐month period were independent predictors of mortality in patients with advanced heart failure.
Simulations of Kelvin–Helmholtz modes in the dusty plasma environment of noctilucent clouds
Authors: WIECHEN HEINZ M. 
Published: October 2006

AbstractWe present results of quantitative multi-fluid simulations of the nonlinear dynamics of Kelvin–Helmholtz modes in the partially ionized dusty plasma of noctilucent clouds. Noctilucent clouds are a typical example of dusty plasmas in the Earth's mesosphere/lower thermosphere. A specific feature observed in noctilucent clouds is wavy, turbulent structure. Possible explanations for these structures, which are discussed in the literature, are based on hydrodynamical models. The dusty plasma aspect has been widely neglected, so far. In this paper we examine the nonlinear dynamics of Kelvin–Helmholtz modes in noctilucent clouds from the viewpoint of dusty plasma dynamics. The corresponding results are in good qualitative and quantitative agreement with observations.
THE ADENOSINE DIPHOSPHATE‐ADENOSINE TRIPHOSPHATE EXCHANGE REACTION OF EXTRACTED CEREBRAL MICROSOMES
Authors: SWANSON P. D. 
Published: October 2006

Abstract—Microsomal fractions prepared from guinea pig cerebral cortex manifested ADP‐ATP exchange activity, 40–99 per cent of which was extractable by dilute salt solutions. All of the (Na+, K+)‐ATPase activity remained in the particulate material. The unextracted ADP‐ATP exchange activity was stimulated six to seven fold by a non‐ionic detergent (Lubrol W). When pre‐extracted microsomes were sedimented in a sucrose density gradient, the ADP‐ATP exchange activity was more widely distributed than (Na+, K+)‐ATPase or adenylate kinase activities. The ADP‐ATP exchange activity of microsomes extracted with NaI was stimulated by Na+ ions when the Mg2+ concentration in the reaction mixture was low (0·2 mm). The Na+ stimulation of exchange activity was more variable than was the stimulation of phosphate formation by Na+ plus K+. The Na+‐stimulated ADP‐ATP exchange reaction of extracted microsomes may be a component of the (Na+, K+)‐ATPase system, which has not been freed from adenylate kinase or possibly other contributing enzyme systems.
NON‐ENZYMIC INCORPORATION OF AMINES INTO PROTEOLIPID PROTEIN1
Authors: Mokrasch L. C. , Andelman R. 
Published: October 2006

Abstract—Proteolipid protein binds biogenic amines irreversibly. The bound amines can be recovered as the original compounds and as complexes with polypeptide after proteolysis or acid hydrolysis. The properties of the protein‐bound tryptamine are consistent with the concept that the amine is covalently linked by its primary amine group. Mescaline, 3,4‐dihydroxyphenylethylamine, 5‐hydroxytryptamine (5‐HT) and histamine also bind irreversibly to proteolipid protein. 5‐Hydroxytryptamine and mescaline bind similarly to other proteins (casein, ovalbumin, serum albumin and a serum protein mixture), but proteolipid binds the amines to a greater extent.
THE METABOLISM OF γ‐AMINOBUTYRIC ACID (GABA) IN THE LOBSTER NERVOUS SYSTEM–UPTAKE OF GABA IN NERVE‐MUSCLE PREPARATIONS1
Authors: Iversen L. L. , Kravitz E. A. 
Published: October 2006

Abstract—The lack of information on the mechanism of inactivation of the crustacean neuromuscular inhibitory transmitter compound prompted a study of the disposition of radioactive γ‐aminobutyric acid (GABA) in lobster nerve‐muscle preparations.A specific GABA transport system was found. Radioactive GABA was concentrated by the tissues to levels several times those in the medium, and net uptake could be demonstrated. The process was dependent on sodium ions in the medium; neither lithium nor choline could substitute for sodium. Incubations with increasing GABA concentrations indicated that uptake was a saturable mechanism with an apparent Km of 5.8 × 10−5m.Of many compounds tested, only desmethylimipramine, chlopromazine (and several related compounds), and certain close structural analogues (guanidinoacetic acid, β‐guani‐dinopropionic acid and,β‐hydroxy‐GAB A) were effective inhibitors of uptake. The inhibition with all these compounds, however, was at high concentrations (5 × 10−4 to 10−3m) which limited their usefulness for physiological studies.A separate uptake mechanism for glutamate was found in the lobster nerve‐muscle preparations. This process was not described in detail, but certain properties are similar to those of the GABA transport system.The cellular location of the GABA uptake system remains unknown. By analogy with noradrenaline inactivation, however, it is postulated that uptake could serve to terminate the physiological actions of GABA by rapidly removing it from its sites of action in synaptic clefts.
FLOW OF PROTEIN AND RIBONUCLEIC ACID IN PERIPHERAL NERVE
Authors: Bray J. J. , Austin L. 
Published: October 2006

Abstract— –Radioactively labelled leucine and orotic acid were injected into the ventral horn of the lumbar region of the spinal cord. The outflow of labelled products into the sciatic nerve was studied.Leucine is rapidly incorporated into protein and to a lesser extent into lipid. The labelled protein is transported down the nerve, apparently by axoplasmic flow. This labelled protein was present in all sub‐cellular fractions of nerve although the soluble fraction had the highest specific activity.Orotic acid is converted to a number of nucleotide derivatives and RNA. Both the nucleotides and RNA move down the sciatic nerve, but the pattern of movement is diffuse whereas protein appears to move as a discrete band.The results suggest that two systems may be operating, one in which part of the RNA is transported by axoplasmic flow along the nerve and the other involving a synthesis of RNA in the nerve from precursors which flow down the nerve. This labelled RNA was membrane bound and on sedimentation analysis, proved to be predominantly of ribosomal type.
PHOSPHOLIPIDS IN THE NERVOUS SYSTEM OF MOLLUSCS
Authors: Kreps E. , Smirnov A. , Chirkovskaya E. , Patrikeeva M. , Krasilnikova V. 
Published: October 2006

Abstract The phospholipid composition of nervous ganglia of the bivalve Unio crassa, the gastropod Helix pomatia and the cephalopods Octopus sp. and Ommastrephes sloanei pacificus have been investigated.The ganglia of cephalopods contain considerably more phospholipids than do gastropod and bivalve ganglia. Especially rich in phospholipids are the optic ganglion of the squid Ommastrephes and the cerebral ganglion of Octopus, where their content is of the same order as in the brain of teleosts and amphibia.In the ganglia of the lower molluscs, the bivalve and the gastropod, no sphingomyelin nor X‐phospholipid could be detected.No sphingomyelin nor X‐phospholipid were found in the optic ganglion of Octopus, whereas in its cerebral ganglion sphingomyelin but no X‐phospholipid was present.In both the optic and the cerebral ganglia of the squid Ommastrephes both sphingomyelin and X‐phospholipid were found.
SELECTIVE INCREASE OF BRAIN DOPAMINE INDUCED BY γ‐HYDROXYBUTYRATE: STUDY OF THE MECHANISM OF ACTION*
Authors: Gessa G. L. , Crabai F. , Vargiu L. , Spano P. F. 
Published: October 2006

Abstract— γ‐Hydroxybutyrate (γ‐OH) produces a selective accumulation of brain DA not only in normal animals but also in reserpinized animals. This is especially evident after the administration of DOPA; while in parallel experiments γ‐OH does not influence significantly the amount of 5‐HT present in brain after 5‐HTP treatment.γ‐OH does not raise DA in rats after inhibition of tyrosine hydroxylase. The accumulation of brain DA is not due to inhibition of MAO or COMT activity.
THE HETEROGENEITY OF RAT BRAIN MITOCHONDRIA ISOLATED ON CONTINUOUS SUCROSE GRADIENTS1
Authors: Neidle A. , Van Den Berg C. J. , Grynbaum A. 
Published: October 2006

Abstract— The distribution of a series of enzymes in the post‐nuclear supernatant of rat brain homogenates was investigated following continuous density‐gradient centrifugation. The enzymes studied were acetyl coenzyme A synthetase, glutamic dehydrogenase, glutamine synthetase, glutaminase I, succinic dehydrogenase and monoamine oxidase. Each of these enzymes with the exception of glutamine synthetase appears predominantly in the mitochondrial region of the gradient. Although about 20 per cent of this enzyme is present in the crude mitochondrial pellet, on density gradient centrifugation no special association of glutamine synthetase with any of the mitochondrial fractions was observed. Each of the other enzymes studied was found to have a characteristic distribution in the gradient; this suggests that brain mitochondria may be heterogeneous both in buoyant density and in their enzyme content. Three principal fractions are described: (i) dense particles containing high concentrations of acetyl coenzyme A synthetase and glutamic dehydrogenase; (ii) a fraction comprising the bulk of the mitochondria with high levels of monoamine oxidase, succinic dehydrogenase and glutaminase I; and (iii) particles in the synaptic ending region of the gradient characterized by relatively high levels of monoamine oxidase and succinic dehydrogenase and containing only small amounts of the other enzymes studied.If the mitochondrial heterogeneity that is observed on centrifugation reflects the existence within brain cells of mitochondria with specialized function, a partial explanation may be available for multiple pools of tricarboxylic acid cycle intermediates which have been postulated from isotopie labelling experiments.
IS THERE BIDIRECTIONAL TRANSPORT OF NORADRENALINE IN SYMPATHETIC NERVES?
Authors: Geffen L. B. , Hunter C. , Rush R. A. 
Published: October 2006

Abstract—The experiments were designed to detect somatopetal transport of [14C]noradrenaline in the postganglionic sympathetic nerves supplying the cat spleen and sheep eye. The animals were treated with nialamide to protect the radioactive noradrenaline, after uptake into the nerve terminals, from monoamine oxidase.In the spleen, the transmitter stores were labelled by infusion of [14C]noradrenaline into a branch of the splenic artery. The branches of the nerves to the infused and non‐infused sides of the spleen were ligated in an attempt to arrest, distal to the constriction, any noradrenaline transported somatopetally in the axons from their terminals. After 24 hr, however, there was less radioactivity in the nerves distal compared to proximal to the constriction, despite heavier labelling of the terminal transmitter stores in the infused portion of the spleen. The proximal accumulation of radioactivity could be attributed to a somatofugal transport of [14C]noradrenaline.Experiments were also done on the intact sympathetic nerve supply of the sheep eye. The sympathetic nerve terminals in the smooth muscle of the left eye were heavily labelled 5 days after the injection of [14C]noradrenaline into the left vitreous humour. However, both superior cervical ganglia were only lightly labelled, and there was no significant difference in the radioactivity present in the two ganglia.The results provide no support for a bidirectional transport of noradrenaline in sympathetic nerves but are consistent with a somatofugal transport of the amine storage vesicles from their site of synthesis in the soma to the axon terminals.
DECARBOXYLATION STUDIES OF GLUTAMATE, GLUTAMINE, AND ASPARTATE FROM BRAIN LABELLED WITH [1‐14C] ACETATE, l‐[U‐14C]‐ASPARTATE, AND l‐[U‐14C]GLUTAMATE
Authors: Nicklas W. J. , Clarke D. D. , Berl S. 
Published: October 2006

Abstract—Studies in vivo and in vitro of the distribution of label in C‐1 of glutamate and glutamine and C‐4 of aspartate in the free amino acids of brain were carried out. [1‐14C]‐Acetate was used both in vivo and in vitro and l‐[U‐14C]aspartate and l‐[U‐14C]glutamate were used in vitro.

The results obtained with labelled acetate and aspartate suggest that CO2 and a 3‐carbon acid may exchange at different rates on a COa‐fixing enzyme.
The apparent cycling times of both glutamate and glutamine show fast components measured in minutes and slow components measured in hours.
With [1‐14C]acetate in vitro glutamine is more rapidly labelled in C‐1 than is glutamate at early time points; the curves cross over at about 7 min.
The results support and extend the concept of metabolic compartmentation of amino acid metabolism in brain.
TRANSGLUTAMINASE LEVELS IN BRAIN AND RETICULOENDOTHELIAL CELLS DURING ALLERGIC ENCEPHALOMYELITIS DETERMINED BY A RADIOCHEMICAL METHOD1,2
Authors: Wajda I. J. , Lee J. M. , Neidle A. 
Published: October 2006

Abstract—A sensitive method for the assay of transglutaminase based on incorporation of [14C]methylamine into carbobenzoxy l‐glutaminyl l‐valine methyl ester is described.Transglutaminase levels were measured in the livers, brains and white cells obtained from peritoneal exudates of two strains of mice during the development of experimental allergic encephalomyelitis (EAE). The sensitive (BSVS) strain developed the disease, while the resistant (BRVR) mice did not succumb to EAE. The liver enzyme in the sensitive mice increased to significantly higher levels during the early stages of the disease. Low values were recorded in the same animals during paralysis.Brain transglutaminase increased to 300 per cent of normal values in the sensitive mice during paralytic stages of EAE. In the resistant strain of mice transglutaminase levels doubled in the mixture of cells obtained from the peritoneal wash. In the sensitive mice, normal values were recorded in those cells.It is suggested that transglutaminase is actively involved in immunological reactions taking place in the brain in EAE sensitive mice and in the reticuloendothelial system of EAE resistant mice.
CHOLINE ACETYLTRANSFERASE ACTIVITY OF HUMAN BRAIN TISSUE DURING DEVELOPMENT AND AT MATURITY
Authors: Bull G , Hebb Catherine , Ratković Dobrila 
Published: October 2006

Abstract— (1) On analysis of human brain tissue to determine its choline acetyltransferase (ChAc) content the recovery of enzyme from many regions is very poor when the tissue is acetone‐dried and then extracted in the standard manner; for this reason the method is unsuitable when quantitative recoveries are required; it is preferable to prepare sucrose homogenates and activate these with ether before incubation.(2) From measurements made on homogenates of one adult brain the highest concentration of ChAc was found in the putamen and the lowest in the corpus callosum. The caudate nucleus also had a high activity. As in other mammals, the concentration of enzyme in the cerebellum was found to be low. Analogous results were obtained on a nine‐year‐old brain but the level of ChAc activity was generally higher than in the older brain.(3) During foetal development up to thirty‐two weeks, ChAc is higher in the cerebellum than in the caudate, the thalamus, corpora quadrigemina, medulla and spinal cord. In all regions the concentration and total amount of enzyme rise fairly steadily up to this time; between 24 and 32 weeks, however, its concentration in the cerebellum and corpora quadrigemina falls slightly although the total increases considerably.(4) Comparison of the results with the data of other authors indicates general agreement between the distribution of the enzyme in the human brain and its distribution in other mammals, especially the rhesus monkey. The corpus callosum may be an exception since in man it contains little ChAc while in lower mammals it seems to have relatively high concentrations of both ACh and ChAc.(5) In comparing the values for ChAc reported here with the values for AChE reported by others, three tissues, the globus pallidus, substantia nigra and cerebellum are found to be exceptional in that relative to their concentration in the caudate the activity of ChAc is only about one‐tenth that of AChE.
PURIFICATION AND SOME PROPERTIES OF ACID MUCOPOLYSACCHARIDES OF BOVINE BRAIN
Authors: Saigo K , Egami F 
Published: October 2006

Abstract— (1) Acid mucopolysaccharide was obtained from bovine brain and fractionated by Dowex 1 ×−2 column chromatography. Infrared spectra, elution profiles and chemical composition revealed that it was essentially composed of hyaluronic acid and chondroitin sulphates.(2) Six unsaturated dissacharides containing different types of ester‐sulphate, namely ΔDi‐OSh, ΔDi‐OS, ΔDi‐4S, ΔDi‐6S, ΔDi‐diSD, and ΔDi‐diSE, were detected in the chondroitinase‐ABC and ‐AC digests of sulphated acid mucopolysaccharide fractions. Their molar fraction was determined and the monosulphated disaccharides, ΔDi‐4S and ΔDi‐6S, wére found to be the two main components. A time course curve of digestion with condroitinase‐ABC indicated the existence of small amounts of uronic acid‐containing components resistant to chondroitinase‐ABC.(3) The peptide chains bound to acid mucopolysaccharides were mainly composed of hydrophilic amino acids. Beta‐elimination reaction was performed and at least two amino acids, serine and threonine residues, appeared to be the amino acids of the carbohydrate‐protein linkage regions of chondroitin sulphate fractions.(4) Optical rotatory dispersion of acid mucopolysaccharide‐methylene blue complexes suggested that chondroitin sulphate of bovine brain as well as authentic chondroitin sulphate A and C belonged to right‐screw sense helical acid mucopolysaccharides, while heparin belonged to left‐screw sense.
RAPIDLY‐LABELLED, ACIDIC PHOSPHOLIPIDS OF THE GOLDFISH BRAIN1
Authors: Hollander J. , Hallenbeck J. M. , Agranoff B. W. 
Published: October 2006

Abstract—Homogenates and particulate fractions of goldfish brain incorporated radioactivity from γ‐[32P]ATP selectively into acidic phospholipids during brief periods of incubation. Phosphatidate and lysophosphatidate became strongly labelled and activity was also found in phosphatidyl inositol phosphate and in phosphatidyl inositol diphosphate. When tetraphenylborate (a K+‐complexing agent) was added, a selective stimulation of incorporation of 32P into phosphatidate occurred. The addition of perchlorate (also known to bind K+) did not produce a similar stimulation, nor did the addition of K+ block the stimulation by tetraphenylborate. The stimulation of the labelling of phospholipids by tetraphenylborate appeared to be the result of multiple actions. Besides the evidence that it acted by stimulating the phosphoinositide phosphodiesterase of brain, data were obtained suggesting that it stimulated diglyceride kinase and blocked endogenous destruction of ATP as well. The stimulation by tetraphenylborate was blocked by addition of atropine but not of arecoline.