bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metabotropic glutamate receptor mGluR5 subcellular distribution and developmental expression in hypothalamus
Authors: Van Den Pol Anthony N. , Romano Carmelo , Ghosh Prabhat 
Published: May 2005

AbstractThe metabotropic glutamate receptor mGluR5 is a G‐protein coupled receptor that plays a key role in release of Ca2+ from internal stores via inositol triphosphate mobilization. Western and Northern blot analyses revealed a greatly enhanced expression of mGluR5 in rats during early stages of hypothalamic development compared with the adult. This enhanced developmental expression provides an explanation for the dramatic physiological response of developing neurons to metabotropic glutamate receptor activation and supports the argument that metabotropic glutamate receptors may play an important role in hypothalamic development. During development, expression of the mGluR5 gene was reduced, not only in the hypothalamus but also in other regions of the brain. A differential decrease in mGluR5 protein was found in different brain regions with Western blot analysis. The hypothalamus showed a sixfold decrease in mGluR5 with dovelopment, whereas the cortex showed only a threefold decrease.Immunocytochemistzy with an afflnity‐purified antibody against a peptide deduced from the cloned mGluR5 gene revealed selective expression in some regions in the adult hypothalamus. In the adult and developing (postnatal day 10) brain, immunoreactive neurons were found in the suprachiasmatic nucleus, preoptic area, lateral hypothalamus, and mammillary region, areas where the related metabotropic glutamate receptor mGluR1 is also found. In contrast, the ventromedial nucleus, an area critically involved in the regulation of food intake and metabolic balances, showed strong mGluR5 immunoreactivity but no mGluR1 immunoreactivity. Little or no mGluR5 staining was found in the neurosecretory neurons of the paraventricular, supraoptic, and arcuate nuclei. Ultrastructurally, mGluR5 was associated with the cytoplasmic face of the plasmalemma on hypothalamic dendrites, dendritic spines, and neuronal perikarya in the adult. The strongest immunoreactivity was found in patches on the membrane, sometimes associated with the postsynaptic side of synapses and sometimes associated with nonsynaptic dendritic or perikaryal membrane. Intense immunostaining was found on some astrocyte processes surrounding synaptic complexes containing asymmetrical synapses. These astrocytes would be in an ideal position to receive excitatory signals from glutamatergic axons. Unlike the punctate appearance of immunolabeling on neuronal membranes, astrocytes showed continuous staining along the plasma membrane. © Wiley‐Liss, Inc.
Reduced gravity evaluation of potential spaceflight‐compatible flow cytometer technology
Authors: Crucian Brian , Sams Clarence 
Published: May 2005

AbstractBackgroundThe presence of a spaceflight‐compatible flow cytometer onboard the International Space Station would be extremely beneficial for in‐flight medicine and reduced gravity research. In the past, commercially available flow cytometers were not suitable for use during spaceflight due to their size, weight, power, and sheath fluid requirements. Recent advances in cytometer technology have enabled features that now make a spaceflight‐compatible cytometer possible. We evaluated a small, robust novel cytometer with design features that minimize or eliminate many incompatibilities with spaceflight. This cytometer is highly miniaturized and lightweight, does not require sheath fluid, and uses a low‐energy diode laser. The ability to achieve laminar particle flow without sheath fluid is important because an instrument using large liquid volumes and producing an equivalent amount of hazardous liquid waste would not meet spaceflight constraints.MethodsFor this study the cytometer was modified so that stained liquid cell samples could be delivered during reduced gravity. The cytometer was then evaluated onboard the NASA KC‐135 reduced gravity research aircraft. The KC‐135 uses a parabolic flight path to generate essentially zero gravity conditions for 30‐s increments. Typically 40 parabolas are flown per mission, resulting in approximately 20 min of reduced gravity during which research may be performed. During this evaluation, bead‐based cytometer precision, photomultiplier tube linearity, and leukocyte immunophenotype analysis were performed during reduced gravity. The flight data were then compared with ground‐based control data and data generated using a reference cytometer (Beckman‐Coulter XL).ResultsThis novel cytometer functioned well during reduced gravity and produced data comparable to those of ground‐based controls with only minor caveats. The reduced gravity cell immunophenotype data were indistinguishable from ground control data and reference cytometric data. Bead‐based instrument precision (coefficient of variation) was slightly increased during reduced gravity operation, but not to a degree that would affect most common flow cytometric applications. The ability of the instrument to collect absolute cell counts was validated.ConclusionsThis study represents the first generation of real‐time flow cytometry data during zero gravity. With modifications, the evaluated cytometer technology could be the basis from which an operational spaceflight‐compatible flow cytometer is developed. Published 2005 Wiley‐Liss, Inc.
Piracetam in the treatment of cognitive impairment in the elderly
Authors: Reisberg Barry , Ferris Steven H. , Schneck Michael K. , Corwin Jene , Mir Pervez , Friedman Eitan , Sherman Kathleen A. , McCarthy Martin , Bartus Raymond T. 
Published: May 2005

AbstractReisberg, B., S.H. Ferris, M.K. Schneck, J. Corwin, P. Mir, E. Friedman, K.A. Sherman, M. McCarthy, and R.T. Bartus: Piracetam in the treatment of cognitive impairment in the elderly. Drug Dev. Res. 2: 475–480, 1982.Piracetam (Nootropil, 2‐oxopyrrolidone acetamide) has been extensively investigated for the treatment of cognitive impairment. Initial studies on normal subjects and patients with mild or moderate cognitive decline have been somewhat encoruaging. Accordingly, we conducted a further evaluation of the effects of piracetam in the treatment of elderly outpatients 60 to 85 years of age with mild to moderate memory impairment consistent with a diagnosis of Primary Degenerative Dementia (PDD). In our first study, we examined the effects of piracetam in 20 patients. All patients received 7.2 g of piracetam and placebo for 4 weeks in accordance with a double‐blind, randomized treatment order, crossover design with 1‐week washout periods prior to each crossover period. Hence, the total study period for each patient was 10 weeks (1‐4‐1‐4). An analysis of 43 psychometric measures revealed significant improvement (P < 0.05) in only three measures, all favoring the treatment condition. Recent findings support a rationale for examining the effects of piracetam in conjunction with cholinergic precursors in patients with cognitive decline. In our second study we conducted a 1‐week open trial of 1.6 g of piracetam t.i.d. in conjunction with 3 g of choline cholride t.i.d. in 15 patients. Four patients were rated as clinically improved. These “responders” were all subjects with moderate cognitive impairment. The responders showed much higher RBC choline levels than the nonresponders, both at baseline and during treatment. We conclude that the present evidence indicates that the effects of piracetam treatment alone in elderly outpatients with mild to moderate congnitive decline are subtle and not of proven clinical significance. However, studies of longer duration and of piracetam in combination with other agents may eventually show genuine clinical utility.
New methods to determine the CNS effects of antigeriatric compounds: EEG topography and glucose use
Authors: Buchsbaum Montes S. , Cappelletti John , Coppola Richard , Regal Francois , King Anna C. , van Kammen D. P. 
Published: May 2005

AbstractBuchsbaum, M.S., J. Cappelletti, R. Coppola, F. Regal, A. C. King, and D. P. van Kammen: New methods to determine the CNS effects of antigeriatric compounds: EEG topography and glucose use. Drug Dev. Res. 2:489–496, 1982.It has previously been possible to measure regional glucose use in the cerebral cortex in animals only with autoradiographic techniques. With the advent of position emission tomography (PET) using (18F‐2DG) 18F‐2‐deoxyglucose, it is now possible to assess local glucose uptake in μmol/100 g tissue/min in normal volunteers or patients. The PET technique is complex and costly and cannot be repeated frequently because of the radiation dosage. However, local glucose use is closely tied to cerebral blood flow, and studies have related blood flow to EEG frequency measures. In this study, we have simultaneously investigated local glucose metabolism using 18F‐2DG with PET and EEG frequency with 16‐lead topographic mapping in six normal controls. Subjects sat in an acoustically treated darkened room with eyes closed for 10 min prior to, and 30 min following injection of 3–5 mCi 18F‐2DG. Following uptake, seven to eight horizontal scans parallel to the canthomeatal line were made. EEG recordings are made beginning 1 min after injection of the isotope and continuing for 30 min with 12 standard 10/20 system points on the left hemisphere and midline, and 4 additional points between existing posterior leads. Ten‐second EEG epochs are edited for artifacts and then analyzed by fast Fourier transform techniques. Using a cross‐sectional whole‐head atlas, a standardized, approximately equal‐area two‐dimensional representation of a lateral view of the brain was developed and 10/20 system scalp coordinates were projected onto it. EEG power estimates are interpolated for all points on this brain map. Using digital techniques, a 1‐cm‐thick cortical strip is peeled off each PET, slice and conformed to the lateral brain view, and values between strips are interpolated. The result is two simultaneously obtained electrophysiologic and metabolic lateral views of brain function displayed in gray‐scale values represented by dot density. In some subjects with eyes closed, alpha power is high in low glucose‐use regions, such as the occiput. Temporal regions appear low both in glucose use and in most power bands. Parallels between alpha distribution and glucose use are illustrated.
Sonochemical Synthesis and Characterization of Ni(C4H6N2)6(PF6)2, Fe(C4H6N2)6(BF4)2, and Ni(C4H6N2)6(BF4)2 in 1‐Butyl‐3‐methylimidazole with Hexafluorophosphate and Tetrafluoroborate
Authors: Jacob David S. , Makhluf Shirli , Brukental Ishay , Lavi Ronit , Solovyov Leonid A. , Felner Israel , Nowik Israel , Persky Rachel , Gottlieb Hugo E. , Gedanken Aharon 
Published: May 2005

AbstractThis paper reports on the inorganic sonochemical synthesis of crystalline Ni(C4H6N2)6(PF6)2, Fe(C4H6N2)6(BF4)2, and Ni(C4H6N2)6(BF4)2 in the ionic liquids, 1‐butyl‐3‐methylimidazolium hexafluorophosphate (BMI)+(PF6)– and 1‐butyl‐3‐methylimidazolium tetrafluoroborate (BMI)+(BF4)–. The structures of the compounds were determined and refined by using powder X‐ray diffraction methods. The salts crystallize in the trigonal P$\tilde {3}$ space group. IR, Raman and 19F NMR spectroscopic studies confirm that the PF6– and BF4– anions are not bonded to the metal cations. Magnetic measurements reveal the paramagnetic nature of the complexes. Mössbauer investigations show that the iron atom in Fe(C4H6N2)6(BF4)2 is in the oxidation +2 state. The broad EPR signals, which reflect the octahedral symmetry of the nickel complexes, were measured for Ni(C4H6N2)6(PF6)2 and Ni(C4H6N2)6(BF4)2. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
1‐D Open‐Channeled 3‐D Supramolecular Self‐Assembled Frameworks Encapsulating Unprecedented Cyclic (H2O)8 Clusters or Solvent Molecules
Authors: Li Dong‐sheng , Wang Yao‐yu , Luan Xin‐jun , Liu Ping , Zhou Cai‐hua , Ma Hai‐rui , Shi Qiz‐hen 
Published: May 2005

AbstractTwo novel 1‐D coordination polymers, {[Cu(Hhbd)(bpy)]·3H2O}n (1) and {[Cu(Hhbd)(phen)]·H2O·MeOH}n (2) [Hhbd = α‐hydroxybutanedioicate dianion, bpy = 2,2'‐bipyridine, phen = 1,10‐phenanthroline], were rationally designed and synthesized with an identical construction strategy, using Hhbd ligands as bridges and chelating aromatic ligands as terminal ligands. Interestingly, the chelating aromatic ligand and the –OH groups of the Hhbd ligand play an important role in the self‐assembly of the polymeric coordination chain by providing potential supramolecular recognition sites for π–π aromatic stacking and hydrogen‐bond interactions, resulting in the self‐assembly of the molecular double chains to give a 3‐D supramolecular framework with 1‐D open channels. More significantly, in 1 the host framework encapsulates unprecedented centrosymmetric cyclic (H2O)8 clusters that have a chair conformation and are connected into 1‐D arrays by supramolecular association along the 1‐D open channels. In contrast, the channels of 2 contain lattice water and disordered methanol molecules. TGA and XRPD show that the host frameworks of 1 and 2 are stable when the guest solvent molecules are removed from the channels. Variable‐temperature magnetic susceptibility measurements for both complexes indicate the presence of weak antiferromagnetic exchange interactions between adjacent copper(II) ions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Enzymatic and chemical synthesis of phosphatidylcholine regioisomers containing eicosapentaenoic acid or docosahexaenoic acid
Authors: Lyberg Ann‐Marie , Adlercreutz Dietlind , Adlercreutz Patrick 
Published: May 2005

AbstractRegioselective incorporation of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) into phosphatidylcholine (PC) was carried out using enzymatic and chemical synthesis. Incorporation at the sn‐1 position was successfully achieved by lipase‐catalysed esterification of 2‐palmitoyl‐lysophosphatidylcholine (LPC), although in most cases, the enzymes incorporated EPA and DHA at lower rates than other fatty acids. For the incorporation of DHA, Candida antarctica lipase B was the only useful enzyme, while incorporation of EPA was efficiently carried out using either this enzyme or Rhizopus arrhizus lipase. The highest yields in the lipase‐catalysed reactions were obtained at the lowest water activity (close to 0). However, by carrying out the reactions at a higher water activity of 0.22, more EPA and DHA were incorporated. Esterification of 2‐palmitoyl‐LPC with pure EPA at this water activity converted 66 mol‐% of LPC to PC using Rhizopus arrhizus lipase as catalyst. When the fatty acid was DHA and the catalyst Candida antarctica lipase B, 45 mol‐% of PC was obtained. For incorporation of EPA and DHA at the sn‐2 position, phospholipase A2 was used, but the reaction was very slow. Chemical coupling of 1‐palmitoyl‐LPC and EPA or DHA was more efficient, resulting in complete conversion of LPC.
Ionized and total magnesium level in blood serum and plasma of healthy and III adults
Authors: Maj‐Zurawska Magdalena , Hulanicki Adam , Drygieniec Danuta , Pertkiewicz Marek , Krokowski Marcin , Zebrowski Andrzej , Lewenstam Andrzej 
Published: May 2005

AbstractIonized magnesium was measured potentiometrically using a clinical analyzer MICROLYTE 6 (KONE, Finland). Total magnesium was measured colorimetrically. Ionized magnesium (iMg) concentration changes with pH were made to observe the accuracy of the results if they were not recalculated to the actual pH of blood or recalculated with some uncertainty in parameters. The dependence of iMg and iCa on heparin (used as anticoagulant in plasma samples) was made. Less than 40 units per 1 mL of blood decreased the concentration of iMg and iCa less than 1.5%. The range of iMg and total Mg in serum and plasma of healthy and ill adults (short bowel syndrome, myocardial infarct) was investigated and compared. In both illnesses, the concentration of ionized and/or total magnesium is significantly different from the range of healthy people. The range of iMg and total Mg as well as the percentage of iMg against total Mg seem to be specific for a given illness.
Benzoic acid determination through competitive inhibition of mediated bioelectrocatalysis
Authors: Smit Mark H. , Rechnitz Garry A. 
Published: May 2005

AbstractA bioelectrochemical system for the sensing of benzoic acid is described. An enzyme‐based oxygen electrode is constructed where the enzymatic consumption of oxygen by tyrosinase is monitored electrochemically through the mediator 1,2 naphthoquinone, 4‐sulfonate (NQS). The bioelectrocatalysis of oxygen can be electrochemically initiated and terminated and is sensitive to inhibition by benzoic acid in a concentration‐dependent manner. Inhibition of catalytic current results from a competitive interaction of benzoic acid at the enzymatic docking site of NQS. This inhibition of catalytic activity is reversible, and full catalytic activity can be reinstated following the removal of benzoic acid from solution. The sensing of benzoic acid is dependent on the nature of the mediator used, occurring with NQS but not with ferricyanide. These studies provide support for the possibility that analytes can be targeted for detection in such inhibition‐based sensing through the proper selection of mediator.
Analytical performances of lipophilic diamides based alkaline earth ion‐selective electrodes
Authors: Tóth Klára , Lindner Ernö , Horváth Mária , Jeney Judit , Pungor Ernö , Bitter István , Ágai Béla , Töke László 
Published: May 2005

AbstractBased on complex chemical considerations, lipophilic diamide derivatives have been designed and synthesized as ionophores for liquid membrane electrodes. The structure‐selectivity studies revealed that the majority of the ligands exhibit calcium ion selectivity, except the compound bis‐N,N‐dicyclohexyl‐malonamide. The latter has an almost equal selectivity for Ca2+ and Mg2+ and sufficiently rejects sodium ions, thus it lends itself to water hardness measurements.
Oligosiloxane‐modified calix[4]arene ionophores for silicone‐rubber‐membrane sodium ion‐sensitive field‐effect transistors
Authors: Tsujimura Yutaka , Yokoyama Masaaki , Kimura Keiichi 
Published: May 2005

AbstractUnsymmetrical and symmetrical calix[4]arene esters carrying oligosiloxane moiety were designed for neutral carriers of silicone‐rubber‐membrane sodium ion‐sensitive field‐effect transistors (ISFETs). The incorporation of oligosiloxane moiety to calix[4]arene ionophores promotes their dispersibility in silicone rubber, thus bringing about high stability and low impedance of the ion‐sensing membranes and thereby high sensitivity and fast response of the resulting sodium ISFETs.
Membraneless immobilization of xanthine oxidase on organic conducting salt/silicone oil electrodes
Authors: Korell Ulrich , Spichiger Ursula E. 
Published: May 2005

AbstractXanthine oxidase (XOD, E.C. 1.2.3.2) has been immobilized on amperometric electrodes made from the organic conducting salt tetrathiafulvalene‐p‐tetracyanoquinodimethane (TTF‐TCNQ) and silicone oil. Xanthine oxidase was immobilized by various techniques; immobilization by means of hydrophobic interaction was found to yield optimum analytical performance. Except for buffer, no coreactants are required for sensor operation. The response of the XOD electrode to its substrate hypoxanthine can be described by the enzyme‐kinetic Michaelis‐Menten formalism with excellent correlation (in most cases, Γ2 > 0.995). Steady‐state currents are usually measured within 10 seconds. Apparent KM (typically 3 to 10 μM) and saturation current values (0.2 to 3.7 μA, measured with new electrodes) strongly depend on the preparation procedure chosen as did the useful lifetime of the XOD sensors which was up to several weeks at room temperature. The described immobilization methodologies circumvent diffusion problems associated with well‐established biosensor preparation techniques (e.g., physical entrapment in gel or between dialysis membranes) and thus yield biosensors of superior analytical performance.
Development of a regenerable amperometric immunosensor for 7‐hydroxycoumarin
Authors: Lu Bin , Smyth Malcolm R. , Quinn John , Bogan Declan , O'Kennedy Richard 
Published: May 2005

AbstractA regenerable immunosensor, based on a competitive assay principle and utilizing electrochemical detection, was developed for the determination of 7‐hydroxycoumarin. Horseradish peroxidase (HRP) labeled anti‐7‐hydroxycoumarin antibody was employed in the determination, and the enzyme activity was measured as a function of current due to the reduction of hydrogen peroxide in the presence of a mediator (potassium ferrocyanide). Sensor preparation involved chemical immobilization of 7‐hydroxy‐coumarin‐BSA conjugate on a glassy carbon electrode surface using a water soluble carbodiimide, 1 ‐ethyl‐3(3‐dimethyl‐aminopropyl) carbodiimide, as coupling reagent in the presence of N‐hydroxysuccinimide. The competition between the free and immobilized forms of the hapten for their HRP labeled antibody in solution allows for the quantitation of free 7‐hydroxycoumarin. The sensor can be regenerated by simply immersing the electrode tip in acidic media. Under these conditions the hapten‐antibody complex was selectively disrupted without adversely affecting the sensor performance. The conditions for removing the non‐specific adsorption of the enzyme conjugate were also studied. The results showed that the detection range obtained for the hapten was physiologically relevant.
Development of a conducting polymer‐based microelectrode array detection system
Authors: John Richard , Ongarato Daniela M. , Wallace Gordon G. 
Published: May 2005

AbstractAn individually addressable microelectrode array system has been developed in the course of this work. The performance of this system was investigated using conventional electrochemistry (oxidation/reduction or ferrocene carboxylic acid) to demonstrate that independent potential control and current measurement at each of the array components was possible. The practical utility of this system has been demonstrated using a conducting polymer based microarray detection system subsequent to Ion Chromatography. The detection of simple electroinactive ions (e.g., Cl−, SO42−, K+, NH4+) using the array system was achieved and the response at each of the array components was studied as a function of polymer composition.
Disposable nickel screen‐printed sensor based on dimethylglyoxime‐containing carbon ink
Authors: Wang Joseph , Nascimento Valberes B. , Lu Jianmin , Park Deog Su , Angnes Lucio 
Published: May 2005

AbstractDisposable complexing (preconcentrating) sensor strips for trace nickel have been fabricated by doping the screen‐printed carbon ink with ligand dimethylglyoxime (DMG). The carbon ink is shown to be a useful matrix for incorporating the DMG, with the ligand maintaining its attractive coordination chemistry following the printing and firing processes. The response is characterized with respect to the ink composition, preconcentration period and potential, solution conditions and other variables. A short (30 s) accumulation period yields a detection limit of 5 μg/L nickel. The highly stable response indicates great promise for use as reusable devices. Measurement of nickel in a river water sample is demonstrated. Such incorporation of ligands into screen‐printed carbon inks provides a promising route for thick‐film sensors based on the preconcentration/voltammetric strategy.