bluuebunny/crossref_metadata_2025 huggingface dataset:
The binding of [3H]R‐PIA to A1 adenosine receptors produces a conversion of the high‐ to the low‐affinity state
Authors: Casadó V. , Mallol J. , Canela E.I. , Lluis C. , Franco R.
Published: July 2002

Kinetic evidence for negative cooperativity on the binding of [3H]R‐PIA to A1 adenosine receptors was obtained from dissociation experiments at different ligand concentrations and from the equilibrium isotherm. The dissociation curves indicate that there is an apparent ligand‐induced transformation of high‐ to low‐affinity states of the receptor. At concentrations of 18.2 nM R‐PIA or higher there was only found the low‐affinity state of the receptor. In view of these results equilibrium binding data were analyzed by the usual two‐state model (assuming that there is an interconversion between them) and by the negative cooperativity model employing the Hill equation.
Rainbow trout cytochrome P‐450c17 (17α‐hydroxylase/17,20‐lyase) cDNA cloning, enzymatic properties and temporal pattern of ovarian P‐450c17 mRNA expression during oogenesis
Authors: Sakai Noriyoshi , Tanaka Minoru , Adachi Shinji , Miller Walter L. , Nagahama Yoshitaka
Published: July 2002

A cDNA clone encoding cytochrome P‐450c17 (17α‐hydroxylase/17,20‐lyase) was isolated from a rainbow trout ovarian follicle cDNA library. The cDNA contained an open reading frame of 1,542 nucleotides encoding a protein of 514 amino acid residues. The amino acid sequence of trout P‐450c17 shows a much greater homology with chicken P‐450c17 than with that of human, bovine and rat. The trout P‐450c17 expressed in non‐steroidogenic mammalian COS‐1 cells showed both 17α‐hydroxylase and 17,20‐lyase activities. The cDNA only hybridized to a single species or mRNA (2.4 kb) isolated from rainbow trout ovaries; the 2.4 kb transcripts were abundant in trout ovaries during the later stages of oogenesis.
Oleoylamine and sphingosine stimulation of phosphatidylserine synthesis by LA‐N‐2 cells is protein kinase C independent
Authors: Singh Indrapal N. , Sorrentino Giuseppe , Massarelli Raphael , Kanfer Julian N.
Published: July 2002

The presence of sphingosine and oleoylamine in the culture medium of LA‐N‐2 cells stimulated the incorporation of [3H]serine into its corresponding phospholipid, phosphatidylserine (PtdSer). The optimum stimulation for sphingosine and oleoylamine were 50 μM and 100 μM, respectively. Oleoylamine increased the incorporation of [3H]serine over 6‐fold while sphingosine increased the incorporation of [3H]serine over 2.5‐fold. The amount of radioactivity found in water‐soluble components and in protein was similar to that found with control LA‐N‐2 cells. The incorporation of [3H]choline and [3H]ethanolamine into their corresponding phospholipids were decreased in the presence of either oleoylamine or sphingosine. A protein kinase C (PKC) activator, DiC8, and a PKC inhibitor, H7, did not influence the enhanced phosphatidylserine formation by sphingosine and oleoylamine. In addition, there were no differences in the stimulatory effect of sphingosine and oleoylamine discernable between PKC down‐regulated cells or controls. These observations indicate that this oleoylamine and sphingosine mediated enhanced phosphatidylserine synthesis is PKC‐independent.
Polyamines enhance calcium mobilization in fMet‐Leu‐Phe‐stimulated phagocytes
Authors: Walters John D. , Sorboro David M. , Chapman Kena J.
Published: July 2002

Spermidine and putrescine (50 μM‐1 mM), found in exudates from infection sites, significantly enhance fMet‐Leu‐Phe‐induced Ca2+ mobilization in differentiated HL‐60 cells and polymorphonuclear leukocytes (PMNs) by delaying the return to basal cytosolic Ca2+ levels. This enhancement by polyamines is associated with inhibition of Ca2+ efflux across the plasma membrane. In parallel with their effects on Ca2+ signaling, polyamines also significantly prolong the kinetics of fMet‐Leu‐Phe‐induced protein kinase C translocation. Thus, polyamines may play a novel role in modulating regulatory events in phagocytes.
Cloning and sequencing of mouse collagenase cDNA Divergence of mouse and rat collagenases from the other mammalian collagenases
Authors: Henriet Patrick , Rousseau Guy G. , Eeckhout Yves
Published: July 2002

Mouse collagenase cDNA was cloned and sequenced. The deduced amino acid sequence was compared to those of the other mammalian collagenases and related matrix metalloproteinases. These comparisons, as well as those of some enzymatic properties, show that the rodent (mouse and rat) interstitial collagenases are very similar but differ more from the other interstitial collagenases than does human neutrophil collagenase. This supports the hypothesis that the order Rodentia is an outgroup to the other eutherian (placental) mammalian orders.
β‐Crystallins insolubilized by calpain II in vitro contain cleavage sites similar to β‐crystallins insolubilized during cataract
Authors: David Larry L. , Shearer Thomas R.
Published: July 2002

Incubation of soluble proteins from rat lens with the protease calpain II caused the precipitation of β‐crystallin polypeptides. Two‐dimensional electrophoresis and sequence analysis identified β‐crystallin polypeptides both before and after their precipitation by calpain II. β‐crystallin polypeptides precipitated by calpain were cleaved at their NH2‐terminal extensions. These cleavage sites were similar to cleavage sites occurring in β‐crystallin polypeptides precipitated during formation of experimental cataract induced by an overdose of selenite. These data suggested that calpain II caused β‐crystallin insolubilization during cataract formation, and indicated that the process can be mimicked in vitro.
The effect of crystallinity on hydroxyapatite‐induced production of reactive oxygen metabolites by polymorphonuclear leukocytes
Authors: Nagase Mitsuo , Hajime Nishiya , Abe Yoshihiro
Published: July 2002

To assess the role of crystallinity in biological response, we quantitated the generation of reactive oxygen metabolites in human polymorphonuclear leukocytes (PMN) with a chemiluminescence assay using three hydroxyapatite preparations with sintering temperatures of 1,200°C and 900°C and a drying temperature of 110°C on the basis of equal weights (1 mg/ml). These crystals have almost the same average diameters and similar average zeta potentials. The crystals prepared at higher temperatures have higher crystallinity, or larger domain sizes, which were calculated by X‐ray diffraction line broadening. The production of reactive oxygen metabolites by PMN in hydroxyapatite of 1,200°C was 10‐times that by PMN in hydroxyapatite of 900°C and more than 50‐times greater than that in hydroxyapatite of 110°C. A single linear correlation was observed for a plot of log (peak chemiluminescence levels) vs. a plot of log (domain sizes). These results clearly show that the maximal effect of crystallinity on hydroxyapatite‐induced production of reactive oxygen metabolites by human PMN was seen at higher crystallinity.
Human CD40‐ligand: molecular cloning, cellular distribution and regulation of expression by factors controlling IgE production
Authors: Gauchat Jean-François , Aubry Jean-Pierre , Mazzei Gonzalo , Life Paul , Jomotte Therese , Elson Greg , Bonnefoy Jean-Yves
Published: July 2002

Here we report the cloning of the cDNA for human CD40‐Ligand (CD40‐L) from a CD4‐positive T cell clone. The deduced amino acid sequence predicts a type II membrane protein of 261 amino acids. Northern blot and FACS analysis of PBMNC revealed that the human CD40‐L can be detected on T cells and is absent from B cells and monocytes. The human CD40‐L is expressed on both CD4‐ and CD8‐positive T cells, (CD45RO+) and (CD45RA+) subsets. We observed that IL‐4, an inducer of IgE production, upregulated CD40‐L mRNA level while IFNy, an inhibitor of IgE synthesis, reduced the expression of CD40‐L mRNA. These data suggest a the correlation between human CD40‐L expression and IgE production.
Isolation, primary structures and metal binding properties of neuronal growth inhibitory factor (GIF) from bovine and equine brain
Authors: Pountney Dean L. , Fundel Sibylle M. , Faller Peter , Birchler Neil E. , Hunziker Peter , Vas̆ák Milan
Published: July 2002

Human neuronal growth inhibitory factor (GIF) impairs the survival of cultured neurons and is deficient in the brains of Alzheimer's disease victims. We have isolated and sequenced analogous proteins from bovine and equine brain. By comparing their primary structures with those of human, mouse and rat GIFs, a consensus GIF sequence was obtained. Although this exhibits ca. 65% similarity with primary structures of mammalian metallothioneins (MTs), some significant differences are expected in the content of helix and turn secondary structures. In contrast to MTs, which usually bind 7 Zn(II) ions, human, bovine and equine GIFs contain 1–4 Cu(I) and 3–5 Zn(II) ions in species‐specific ratios. The observed Cu(I) phosphorescence (λmax 550–590 nm; τ, 100 μs at 77 K) indicates the presence of the cuprous ion. Both bovine Cu1Cd5‐ and the equine Cu3Cd3‐GIF derivatives (Cd replacing Zn) exhibit cadmium‐dependent absorption and CD features between 220–260 nm characteristic of Cd‐thiolate clusters similar to those in Cd‐MTs.
Maternal brain death during pregnancy
Authors: Vives A. , Carmona F. , Zabala E. , Fernández C. , Cararach V. , Iglesias X.
Published: July 2002

A case of a 36‐year‐old woman diagnosed brain dead secondary to pneumococcal meningitis at 27 weeks of gestation is presented. In spite of aggressive therapy, supportive intensive care was possible for only 36 h. Signs of fetal distress appeared and a cesarean section was performed. The complexity of supportive care and its ethical implications are discussed.
Spectroscopic studies on the active site of hydroperoxide lyase; the influence of detergents on its conformation
Authors: Noordermeer Minke A. , Veldink Gerrit A. , Vliegenthart Johannes F.G.
Published: July 2002

Expression of high quantities of alfalfa hydroperoxide lyase in Escherichia coli made it possible to study its active site and structure in more detail. Circular dichroism (CD) spectra showed that hydroperoxide lyase consists for about 75% of α‐helices. Electron paramagnetic resonance (EPR) spectra confirmed its classification as a cytochrome P450 enzyme. The positive influence of detergents on the enzyme activity is paralleled by a spin state transition of the heme Fe(III) from low to high spin. EPR and CD spectra showed that detergents induce a subtle conformational change, which might result in improved substrate binding. Because hydroperoxide lyase is thought to be a membrane bound protein and detergents mimic a membrane environment, the more active, high spin form likely represents the in vivo conformation. Furthermore, the spin state appeared to be temperature‐dependent, with the low spin state favored at low temperature. Point mutants of the highly conserved cysteine in domain D indicated that this residue might be involved in heme binding.
The C‐terminus of dUTPase: observation on flexibility using NMR
Authors: Nord Johan , Nyman Per-Olof , Larsson Gunilla , Drakenberg Torbjörn
Published: July 2002

The dynamics of the C‐terminus of the dUTPases from Escherichia coli and equine infectious anaemia virus (EIAV) were studied by 1H–15N nuclear magnetic resonance spectroscopy. The two enzymes differ with regard to flexibility in the backbone of the 15 most C‐terminal amino acid residues, some of which are conserved and essential for enzymic activity. In the bacterial enzyme, the residues closest to the C‐terminus are highly flexible and display a correlation time in the nanosecond time range. No similar high flexibility could be detected for the C‐terminal part of EIAV dUTPase, indicating a different time range of flexibility.
Intrinsic fluorescence changes and rapid kinetics of proteinase deformation during serpin inhibition
Authors: Tew Deborah J , Bottomley Stephen P
Published: July 2002

The X‐ray crystal structure of the serpin–proteinase complex suggested that the serpin deformed the proteinase thereby inactivating the molecule. Using a variant of α1‐antitrypsin in which both tryptophan residues have been replaced by phenylalanine, we have shown that the proteinase becomes partially unfolded during serpin inhibition. The tryptophan free variant, α1‐antitrypsin(FF), is fully active as an inhibitor of thrombin. Thrombin has a fluorescence emission maximum of 340 nm which blue shifts to 346 nm, concomitant with a 40% increase in intensity, upon formation of the serpin–proteinase complex indicative of substantial conformational change within the proteinase. Stopped‐flow analysis of the fluorescence changes within the proteinase indicated a two‐step mechanism. A fast bimolecular reaction with a rate constant of 2.8×106 M−1 s−1 is followed by a slow unimolecular process with a rate of 0.26 s−1 that is independent of concentration. We propose that the first rate is formation of an initial complex which is then followed by a slower process involving the partial unfolding of the proteinase during its translocation to the opposite pole of the serpin.
The vav proto‐oncogene product (p95vav) interacts with the Tyk‐2 protein tyrosine kinase
Authors: Uddin Shahab , Sweet Michelle , Colamonici Oscar R , Krolewski John J , Platanias Leonidas C
Published: July 2002

© 1997 Federation of European Biochemical Societies.
Extracellular K+ and Ba2+ mediate voltage‐dependent inactivation of the outward‐rectifying K+ channel encoded by the yeast gene TOK1
Authors: Vergani Paola , Miosga Thomas , Jarvis Simon M. , Blatt Michael R.
Published: July 2002

Gating of the yeast K+ channel encoded by the Saccharomyces cerevisiae gene TOK1, unlike other outward‐rectifying K+ channels that have been cloned, is promoted by membrane voltage (inside positive‐going) and repressed by extracellular K+. When expressed in Xenopus laevis oocytes, the TOK1p current rectified strongly outward, its activation shifting in parallel with the K+ equilibrium potential when the external K+ concentration ([K+]o) was increased above 3 mM. Analysis of the TOK1p current indicated that two kinetic components contributed to the conductance and the voltage sensitivity of the conductance. By contrast, the [K+]o sensitivity of the current was accommodated entirely within the slow‐relaxing component; it was diminished near 1 mM [K+]o, and at submillimolar concentrations the voltage dependence of the TOK1p conductance was insensitive to [K+]o. External Rb+, the K+ channel blockers Cs+ and Ba2+ – but not Na+, Ca2+ or Mg2+ – substituted for K+ in control of TOK1p activation, indicating a specificity in cation interaction with the TOK1p gate. These and additional results indicate that external K+ acts as a ligand to inactivate the TOK1p channel, and they implicate a gating process mediated by a single cation binding site within the membrane electric field, but distinct from the permeation pathway. © 1997 Federation of European Biochemical Societies.
Construction and expression in the yeast Pichia pastoris of functionally active soluble forms of the human costimulatory molecules B7‐1 and B7‐2 and the B7 counter‐receptor CTLA‐4
Authors: Gerstmayer Bernhard , Pessara Ulrich , Wels Winfried
Published: July 2002

We have generated soluble recombinant forms of the costimulatory molecules B7‐1 and B7‐2, and their counter‐receptor CTLA‐4 using a yeast Pichia pastoris expression system. Fragments comprising the extracellular domains of human B7‐1, B7‐2, and CTLA‐4 molecules were expressed at high levels and could be purified from culture supernatants following a simple one‐step purification protocol. The recombinant proteins retained their functionality and specific binding to their natural counterparts could be demonstrated by FACS analysis. In T cell proliferation assays costimulatory activity of immobilized B7‐1 and B7‐2 proteins in the presence of an anti‐CD3 antibody was observed with the B7‐1 protein being more potent than B7‐2.
Enhanced oxidizability of ubiquinol and α‐tocopherol during lovastatin treatment
Authors: Palomäki Ari , Malminiemi Kimmo , Metsä-Ketelä Timo
Published: July 2002

A double‐blinded, placebo‐controlled cross‐over trial was carried out with 27 hypercholesterolemic men with coronary heart disease. During the 6‐week treatment period lovastatin (60 mg/day) decreased fasting serum LDL cholesterol by 45%, LDL phosphorus by 38% and apoB by 33%. Ubiquinol content diminished by 13% as measured per LDL phosphorus. When LDL was oxidized ex vivo with AMVN both LDL ubiquinol and α‐tocopherol were exhausted faster after lovastatin treatment compared to placebo, by 24% (P<0.005) and 36% (P<0.0001), respectively. Lag time in copper‐induced oxidation of LDL decreased by 7% (P<0.01). This suggests diminished antioxidant‐dependent resistance of LDL to the early phase of oxidative stress.
Aging decreases the abundance of retinoic acid (RAR) and triiodothyronine (TR) nuclear receptor mRNA in rat brain: effect of the administration of retinoids
Authors: Enderlin V , Alfos S , Pallet V , Garcin H , Azaı̈s-Braesco V , Jaffard R , Higueret P
Published: July 2002

Aging is accompanied by troubles resulting from changes in hormonal and nutritional status. Therefore, the abundance of mRNA coding for triiodothyronine (TR) and retinoic acid (RA) nuclear receptors was studied in the brain of young, adult and aged (2.5, 6 and 24 months, respectively) rats. In the brain of aged rats, there was a lower abundance of TR and RAR mRNA and a lower activity of tissue transglutaminase (tTG), an enzyme the gene of which is a target for retinoids. Administration of RA in these rats restored TR and RAR mRNA and the activity of tTG in the brain. The importance of these observations to the function of the aged brain is discussed.
EPR detection of phytophenoxyl radicals stabilized by zinc ions: evidence for the redox coupling of plant phenolics with ascorbate in the H2O2‐peroxidase system
Authors: Yamasaki Hideo , Grace Stephen C
Published: July 2002

Chlorogenic acid (CGA; 3‐o‐caffeoylquinic acid), a phenylpropanoid metabolite of plants, was oxidized by H2O2 in the presence of horseradish peroxidase. The primary and secondary oxidized products both were free radicals which gave EPR multiline signals at g=2.0044 and 2.0042 in the presence of zinc as a spin stabilizing agent. The EPR kinetics showed that ascorbate functioned as a cooperative reductant by regenerating CGA from its corresponding radicals. These results provide evidence to support the idea that the ascorbate‐phenolic redox couple in conjunction with guaiacol peroxidase is an efficient H2O2 scavenging mechanism in higher plants.
Interaction of peroxynitrite with carotenoids and tocopherols within low density lipoprotein
Authors: Pannala Ananth Sekher , Rice-Evans Catherine , Sampson Julia , Singh Surinder
Published: July 2002

Peroxynitrite is a powerful oxidising and nitrating agent generated in vivo by the combination of nitric oxide and superoxide. Previous studies have shown that on exposure to peroxynitrite, low density lipoprotein (LDL) is modified resulting in both a time‐ and concentration‐dependent change to lipid and protein components. The present investigation highlights the reaction between carotenoids and tocopherols, present within the lipophilic phase of LDL, and peroxynitrite at varying concentrations. It was observed that the carotenoids were consumed by a significantly greater proportion than that of the tocopherols with lycopene (87.2±11%) being more reactive than β‐carotene (68.2±5.8%) when exposed to peroxynitrite (50 μM) for 1 min. Among the tocopherols, α‐tocopherol (54.9±20.2%) was more extensively depleted than γ‐tocopherol (14.7±1.09%) at peroxynitrite concentration of 500 μM. It was also observed that peroxynitrite, unlike copper ions, does not lead to significant peroxidation of LDL as determined by the formation of conjugated dienes and thiobarbituric acid‐reactive substances.
Topological analysis of the ATP‐gated ionotrophic P2X2 receptor subunit
Authors: Torres Gonzalo E , Egan Terrance M , Voigt Mark M
Published: July 2002

We investigated the transmembrane topology of the P2X2 receptor subunit expressed in HEK 293 cells. Initial studies using two P2X subunits expressed in tandem indicated that the amino‐ and carboxy‐termini are on the same side of the membrane. Immunofluorescence studies showed the cytoplasmic orientation of the amino‐ and carboxy‐termini. Finally, N‐glycosylation scanning mutagenesis revealed that reporter sites inserted into the central loop, but not those in the amino‐ or carboxy‐terminal regions, were glycosylated, thus suggesting an extracellular placement for that domain. Our results support a two‐transmembrane arrangement for P2X receptors with intracellular amino‐ and carboxy‐termini.
Regulation of the glial glutamate transporter GLT‐1 by glutamate and δ‐opioid receptor stimulation
Authors: Thorlin Thorleif , Roginski Raymond S , Choudhury Kanakendu , Nilsson Michael , Rönnbäck Lars , Hansson Elisabeth , Eriksson Peter S
Published: July 2002

The excitatory effect of presynaptically released glutamate is tightly regulated and terminated by high affinity sodium‐dependent glutamate transporters. The regulation of the glial glutamate transporter GLT‐1 is potentially important in synaptic modulation. Using astroglial cultures prepared from the rat cerebral cortex, we found that the δ‐opioid receptor agonist [d‐pen2,d‐pen5]‐enkephalin decreases and glutamate increases the expression of the GLT‐1 transporter mRNA. Corresponding changes in the uptake kinetics were found after incubation for 48 h with the respective agonists when glial glutamate uptake was measured in primary astroglial cultures. The data suggest that long‐term receptor activation induces alterations in glial glutamate uptake properties.
Intrinsic membrane association of Drosophila cysteine string proteins
Authors: Mastrogiacomo Alessandro , Kohan Sirus A , Whitelegge Julian P , Gundersen Cameron B
Published: July 2002

Cysteine string proteins (csps) are highly conserved constituents of vertebrate and invertebrate secretory organelles. Biochemical and immunoprecipitation experiments implied that vertebrate csps were integral membrane proteins that were tethered to the outer leaflet of secretory vesicles via the fatty acyl residues of their extensively acylated cysteine string. Independently, work of others suggested that Drosophila csps were peripheral membrane proteins that were anchored to membranes by a mechanism that was independent of the cysteine string and its fatty acyl residues. We extended these investigation and found first that sodium carbonate treatment partially stripped both csps and the integral membrane protein, synaptotagmin, from Drosophila membranes. Concomitantly, carbonate released fatty acids into the medium, arguing that it has a mild, solubilizing effect on these membranes. Second, we observed that Drosophila csps behaved like integral membrane proteins in Triton X‐114 partitioning experiments. Third, we found that when membrane‐bound csps were deacylated, they remained membrane bound. Moreover, it appeared that hydrophobic interactions were necessary for this persistent membrane association of csps. Thus, neither reducing conditions, urea, nor chaotropic agents displaced deacylated csps from membranes. Only detergents were effective in solubilizing deacylated csps. Finally, by virtue of the inaccessibility of deacylated csps to thiol alkylation by the membrane‐impermeant alkylating reagent, iodoacetic acid, we inferred that it was the cysteine string domain that mediated the membrane association of deacylated csps. Thus, we conclude that under physiological conditions csps are integral membrane proteins of secretory organelles, and that the cysteine string domain plays a vital role in the membrane association of these proteins.
Alfalfa contains substantial 9‐hydroperoxide lyase activity and a 3Z:2E‐enal isomerase
Authors: Noordermeer Minke A , Veldink Gerrit A , Vliegenthart Johannes F.G
Published: July 2002

Fatty acid hydroperoxides formed by lipoxygenase can be cleaved by hydroperoxide lyase resulting in the formation of short‐chain aldehydes and ω‐oxo acids. Plant hydroperoxide lyases use 13‐ or 9‐hydroperoxy linoleic and linolenic acid as substrates. Alfalfa (Medicago sativa L.) has been reported to contain a hydroperoxide lyase specific for 13‐hydroperoxy linoleic and linolenic acid only. However, in addition to 13‐hydroperoxide lyase activity we found substantial 9‐hydroperoxide lyase activity in alfalfa seedlings as well. The specific activity for 9‐hydroperoxy fatty acids was about 50% of the activity for the 13‐isomers. Furthermore, alfalfa seedlings contain a 3Z:2E‐enal isomerase that converts the 3Z‐enal products to their 2E‐enal isoforms.
Cardiomegaly in the juvenile visceral steatosis (JVS) mouse is reduced with acute elevation of heart short‐chain acyl‐carnitine level after l‐carnitine injection
Authors: Kuwajima Masamichi , Horiuchi Masahisa , Harashima Hideyoshi , Lu Kang-mo , Hayashi Miyuki , Sei Masako , Ozaki Kiyokazu , Kudo Tomoko , Kamido Hiroshi , Ono Akira , Saheki Takeyori , Shima Kenji
Published: July 2002

The long‐term administration of l‐carnitine was very effective in preventing cardiomegaly in juvenile visceral steatosis (JVS) mice, which was confirmed by heart weight as well as the lipid contents in heart tissue. After i.p. injection of l‐carnitine, the concentration of free carnitine in heart remained constant, although serum free carnitine level increased up to 80‐fold. On the other hand, a significant increase in short‐chain acyl‐carnitine level in heart was observed. These results suggest that increased levels of short‐chain acyl‐carnitine, not free carnitine, might be a key compound in the protective effect of l‐carnitine administration in JVS mice.
Up‐regulated EGF receptors undergo to rapid internalization and ubiquitin‐dependent degradation in human cancer cells exposed to 8‐Cl‐cAMP
Authors: Caraglia M. , Di Gennaro E. , Barbarulo D. , Marra M. , Tagliaferri P. , Abbruzzese A. , Budillon A.
Published: July 2002

8‐Cl‐cAMP, a cAMP analogue that antagonizes type I cAMP‐dependent protein kinase, is a novel anti‐tumor agent presently under investigation in clinical trials. Herein we report the effects of this agent on epidermal growth factor receptor expression and degradation in human KB cancer cells. Exposure to 10 μM 8‐Cl‐cAMP for 48 h induced a 65% increase in epidermal growth factor receptor surface expression while the receptor synthesis was 22‐fold enhanced. Analysis of epidermal growth factor‐dependent receptor internalization in 8‐Cl‐cAMP‐treated cells showed a higher endocytosis rate as well as an accelerated degradation which occurred together with an increased receptor ubiquitination. The enhanced degradation of epidermal growth factor receptor correlated with the lack of epidermal growth factor‐induced proliferation and mitogen‐activated protein kinase stimulation. The disregulation of epidermal growth factor receptor internalization and ubiquitin‐dependent degradation could underlay a new mechanism of the anti‐tumor activity of 8‐Cl‐cAMP suggesting its combination with agents that disrupt epidermal growth factor receptor signalling.
Leptin treatment increases suppressors of cytokine signaling in central and peripheral tissues
Authors: Emilsson Valur , Arch Jonathan R.S. , de Groot Rolf P. , Lister Carolyn A. , Cawthorne Michael A.
Published: July 2002

Leptin concentrations are elevated in the majority of obese individuals raising the possibility that leptin resistance contributes to their obesity. Peripheral leptin administration for 48 h caused a several‐fold increase in mRNA encoding the suppressors of cytokine signaling SOCS‐3 and CIS in hypothalamus and peripheral tissues. Paradoxically, CIS and SOCS‐3 mRNAs are also elevated in the leptin‐deficient ob/ob mouse. Forced expression of CIS in insulinoma cells prevented transactivation mediated by leptin. Thus tissues continuously exposed to leptin and/or other factors associated with obesity accumulate excessive amounts of SOCS‐3 and CIS which could provide a potential mechanism for leptin resistance.
The cta3+ gene that encodes a cation‐transporting P‐type ATPase is induced by salt stress under control of the Wis1‐Sty1 MAPKK‐MAPK cascade in fission yeast
Authors: Nishikawa Tomohiro , Aiba Hirofumi , Mizuno Takeshi
Published: July 2002

In Schizosaccharomyces pombe, the Wis1‐Sty1 MAP (mitogen‐activated protein) kinase signaling cascade is known to play a major role in cellular adaptation to adverse external stimuli, including osmotic stress, oxidative stress, nutrient deprivation, DNA‐damaging agents, and heat stress. Nonetheless, it is not known whether or not this particular MAPK cascade is also involved in response to the most common stress, salinity. In this study, we provide evidence that the Wis1‐Sty1 MAP cascade is implicated in salt stress response through regulating expression of a salinity‐inducible gene. The downstream target gene thus identified is the cta3
+ gene, which encodes a cation‐transporting P‐type ATPase. The salt stress‐responsive nature of cta3
+ expression was characterized extensively. It was found that not only the Sty1 MAP kinase but also the Atf1 transcription factor is crucial for the inducible expression of cta3
+. As far as we know, this is the first instance that the stress‐activated Wis1‐Sty1 MAPK cascade plays a role in salt stress response in S. pombe.
Nerve growth factor (NGF) exerts its pro‐apoptotic effect via the P75NTR receptor in a cell cycle‐dependent manner
Authors: Bono Françoise , Lamarche Isabelle , Bornia Josette , Savi P. , Della Valle Giuliano , Herbert Jean-Marc
Published: July 2002

Nerve growth factor (NGF), the prototypic member of the neurotrophin family of growth factors, exerts its action via two receptors, P75NTR and TrkA, the expression of which varies at the cell surface of neuroblastoma cells (SH‐SY5Y cells) in a cycle phase‐specific manner. NGF was pro‐apoptotic on growing cells expressing preferentially P75NTR and exhibited a potent anti‐apoptotic effect on quiescent cells, when TrkA was prevalent at the cell surface, showing that NGF can have a dual action on SH‐SY5Y cells depending on the relative cell surface expression of TrkA and P75NTR. The pro‐apoptotic activity of NGF but not its anti‐apoptotic activity was abrogated by an antibody against the extracellular domain of P75NTR and in cells isolated from P75NTR knock‐out mice indicating that NGF exhibits a pro‐apoptotic activity via P75NTR exclusively. On the other hand, we showed that the anti‐apoptotic activity of NGF was specifically mediated by an interaction with TrkA with no contribution of P75NTR, as demonstrated on SK‐N‐BE cells transfected with TrkA in which NGF was a potent anti‐apoptotic compound but did not exhibit any pro‐apoptotic activity. These results support the hypothesis that the survival response to NGF depends on its binding to TrkA without any involvement of P75NTR which in turn selectively mediates the pro‐apoptotic activity of NGF with no contribution of TrkA and show that, depending on the growth state of the cells, NGF exhibits dual pro‐ or anti‐apoptotic properties via P75NTR and TrkA, respectively.
Mutations in the glucose‐6‐phosphate transporter (G6PT) gene in patients with glycogen storage diseases type 1b and 1c
Authors: Galli Lucia , Orrico Alfredo , Marcolongo Paola , Fulceri Rosella , Burchell Ann , Melis Daniela , Parini Rossella , Gatti Rosanna , Lam Ching-Wan , Benedetti Angelo , Sorrentino Vincenzo
Published: July 2002

Glycogen storage diseases type 1 (GSD 1) are a group of autosomal recessive disorders characterized by impairment of terminal steps of glycogenolysis and gluconeogenesis. Mutations of the glucose‐6‐phosphatase gene are responsible for the most frequent form of GSD 1, the subtype 1a, while mutations of the glucose‐6‐phosphate transporter gene (G6PT) have recently been shown to cause the non 1a forms of GSD, namely the 1b and 1c subtypes. Here, we report on the analysis by single‐stranded conformation polymorphism (SSCP) and/or DNA sequencing of the exons of the G6PT in 14 patients diagnosed either as affected by the GSD 1b or 1c subtypes. Mutations in the G6PT gene were found in all patients. Four of the detected mutations were novel mutations, while the others were previously described. Our results confirm that the GSD 1b and 1c forms are due to mutations in the same gene, i.e. the G6PT gene. We also show that the same kind of mutation can be associated or not with evident clinical complications such as neutrophil impairment. Since no correlation between the type and position of the mutation and the severity of the disease was found, other unknown factors may cause the expression of symptoms, such as neutropenia, which dramatically influence the severity of the disease.
Law and ethics in conflict over confidentiality?
Authors: Dickens B.M , Cook R.J
Published: July 2002

Ethical principles that require the preservation of patients’ confidential information are reinforced by principles found in several areas of law, such as law on contracts, negligence, defamation and fiduciary duty. However, laws sometimes compel disclosures of medical confidences, and more often may justify or excuse disclosures. Legally contentious issues concern patients’ confidences regarding possible unlawful conduct, such as pregnancy termination, and the risk of spread of HIV and other infections. This article reviews the various legal bases of the duty of confidentiality, and legal challenges to the ethical obligation of non‐disclosure. It addresses the justifications and limits of exchange of patients’ health information among healthcare professionals and trainees, and considers legally recognized limits of confidential duties, and the scope of legitimate disclosure. An underlying theme is how to determine whether physicians are ethically justified in employing the discretion the law sometimes affords them to breach patients’ expectations of confidentiality.
Contraceptive technology and family planning services
Authors: Dı́az S
Published: July 2002

A large variety of modern contraceptives is now available, including several means to administer hormonal contraception, highly effective long‐term methods and simple sterilization techniques. Methods under research include immuno‐contraceptives for women and men, hormonal methods for men, new approaches to female hormonal contraception and improved barrier methods. Modern contraceptives are effective and safe for most women, and some methods have beneficial health effects other than prevention of pregnancy. However, underlying health conditions may decrease the safety of a given method. The appropriate use of the technology available requires screening for biomedical conditions and counseling that enables the selection of methods according to the life style of women and couples. Contraceptive methods have had a considerable positive impact on maternal and infant health and on population growth, but unwanted pregnancies and unsafe abortion still occur in large numbers. This shows the need to improve access to and quality of family planning services including the availability of contraceptives, sensitive providers trained in technical matters and communication skills, and communication between the community, the providers and the managers.
Differences in manufacturing strategy decisions between Japanese and Western manufacturing plants: the role of strategic time orientation
Authors: Voss Chris , Blackmon Kate
Published: July 2002

In part, cultural differences between Japan and the West have been cited as contributing to fundamentally different manufacturing strategy orientations. One cultural difference is psychological attitudes toward time, which may lead to different emphases on long‐term and short‐term goals and objectives, i.e., differing strategic time orientations. This paper reports on the analysis of data from an international research study of manufacturing strategy that gathered data from 600 companies in 20 countries. Data on the rates of adoption of strategic manufacturing practices and links between corporate and manufacturing strategy were analysed to test for differences. The results show strong contrasts between Japan and the West and are consistent with a difference in strategic time orientation between the two regions.
The development of vestibulocochlear efferents and cochlear afferents in mice
Authors: Bruce L.L. , Kingsley J. , Nichols D.H. , Fritzsch B.
Published: July 2002

We have reinvestigated the embryonic development of the vestibulocochlear system in mice using anterograde and retrograde tracing techniques. Our studies reveal that rhombomeres 4 and 5 include five motor neuron populations. One of these, the abducens nucleus, will not be dealt with here. Rhombomere 4 gives rise to three of the remaining populations: the facial branchial motor neurons; the vestibular efferents; and the cochlear efferents. The migration of the facial branchial motor neurons away from the otic efferents is completed by 13.5 days post coitum (dpc). Subsequently the otic efferents separate into the vestibular and cochlear efferents, and complete their migration by 14.5 dpc. In addition to their common origin, all three populations have perikarya that migrate via translocation through secondary processes, form a continuous column upon completion of their migrations, and form axonal tracts that run in the internal facial germ. Some otic efferent axons travel with the facial branchial motor nerve from the internal facial genu and exit the brain with that nerve. These data suggest that facial branchial motor neurons and otic efferents are derived from a common precursor population and use similar cues for pathway recognition within the brain. In contrast, rhombomere 5 gives rise to the fourth population to be considered here, the superior salivatory nucleus, a visceral motor neuron group. Other differences between this group and those derived from rhombomere 4 include perikaryal migration as a result of translocation first through primary processes and only then through secondary processes, a final location lateral to the branchial motor/otic efferent column, and axonal tracts that are completely segregated from those of the facial branchial and otic efferents throughout their course inside the brain. Analysis of the peripheral distribution of the cochlear efferents and afferents show that efferents reach the spiral ganglion at 12.5 dpc when postmitotic ganglion cells are migrating away from the cochlear anlage. The efferents begin to form the intraganglionic spiral bundle by 14.5 dpc and the inner spiral bundle by 16.5 dpc in the basal turn. They have extensive collaterals among supporting cells of the greater epithelial ridge from 16.5 dpc onwards. Afferents and efferents in the basal turn of the cochlea extend through all three rows of outer hair cells by 18.5 dpc. Selective labeling of afferent fibers at 20.5 dpc (postnatal day 1) shows that although some afferents are still in early developmental stages, some type II spiral ganglion cells already extend for long distances along the outer hair cells, and some type I spiral ganglion cells end on a single inner hair cell. These data support previous evidence that in mice the early outgrowth of afferent and efferent fibers is essentially achieved by birth.
The DRD2 gene and the risk for alcohol dependence in bipolar patients
Authors: Gorwood P. , Bellivier F. , Adès J. , Leboyer M.
Published: July 2002

The high co-morbidity between bipolar disorder and alcohol dependence may have different explanations, one of them being the existence of common genetic factors for the two disorders. Several candidate genes may be involved but the genes acting in the dopaminergic pathway may be more specifically involved. We have thus tested the role of the gene encoding the D2 dopamine receptor (TaqI A1 allele) in the potentially shared vulnerability to alcohol dependence and bipolar disorder.

One hundred and twenty-two French (for at least two generations) patients were recruited on the basis of hospital or outpatient files and were interviewed with the DIGS. The A1 allele frequencies were compared between four groups, namely, with bipolar patients and co-morbid alcohol dependence (N = 21), with bipolar patients without alcohol morbidity (N = 31), with alcohol dependence without mood disorder (N = 35) and unaffected controls (N = 35).

The Hardy Weinberg equilibrium for the DRD2 Taq1 A1 genotypes was respected for the sample as a whole, and for each subsample. We observed that 42.9% of control subjects have at least one A1 allele, a frequency which is not significantly different from the one observed in the affected sample as a whole (39.1%), neither from patients with alcohol dependence (37.1%), patients with bipolar disorder (48.4%) nor patients with alcohol dependence and bipolar disorder (28.6%). The regression analysis based on the three variables (bipolar disorder, alcohol dependence and interaction between these two disorders) does not explain the presence of the A1 allele of the DRD2 gene.

We thus found no evidence for a significant role of the A1 allele of the D2 dopamine receptor gene in the specific association between bipolar disorder and alcohol dependence in our sample.
Market response to analyst recommendations in the “dartboard” column: the information and price‐pressure effects
Authors: Albert Robert L. , Smaby Timothy R.
Published: July 2002

The market response to securities selected by analysts featured in the “Dartboard” column of The Wall Street Journal (WSJ) is the subject of this study. Prior studies have reported significantly positive abnormal returns on the WSJ issue date, followed by a partial price reversal, suggesting that the initial response is partially attributable to price pressure. If we use a post‐event instead of a pre‐event estimation period, we find a similar event day response but no significant reversal. Though we are unable to reject the possibility of a price pressure effect, our results are generally consistent with the existence of an information effect. We also detect a differential response to securities recommended by analysts invited back to the contest and those recommended by newcomers, suggesting that the information effect is related to the market following recommendations of potentially superior analysts.
Meeting Women'S Health Needs In Yemen: A Midwifery Perspective
Authors: Penney Debra S.
Published: July 2002

Maternal mortality in Yemen is one of the highest in the world. Reaching the rural majority of the population with primary health care services has been a continual priority for the nation. Despite efforts to expand health services, access to maternal and child health care remains low. The training of community midwives nationwide has been undertaken recently to address the need for maternal and child health services, particularly in rural areas. Several lessons have been gained through this initial training that will improve future efforts.
The case of a 61‐year‐old man with unusual headaches
Authors: Yu Margaret , Brooker Sarah , Priyadarshini Shubadra
Published: December 2020

A 61‐year‐old man with past medical history significant for prediabetes, hyperlipidemia and high‐grade prostate intraepithelial neoplasia presents with headaches for one month. Imaging of his brain reveals hydrocephalus and spine imaging reveals a cord lesion. These findings are discussed further in the case.
Intravenous arylsulfatase A in metachromatic leukodystrophy: a phase 1/2 study
Authors: í Dali Christine , Groeschel Samuel , Moldovan Mihai , Farah Mohamed H. , Krägeloh‐Mann Ingeborg , Wasilewski Margaret , Li Jing , Barton Norman , Krarup Christian
Published: December 2020

Objective

Metachromatic leukodystrophy (MLD) is an autosomal recessive lysosomal storage disease caused by deficient activity of arylsulfatase A (ASA), resulting in severe motor and cognitive dysfunction. This phase 1/2 study evaluated the safety and efficacy of intravenous (IV) recombinant human ASA (rhASA; HGT‐1111, previously known as Metazym) in children with MLD.

Methods

Thirteen children with MLD (symptom onset < 4 years of age) were enrolled in an open‐label, nonrandomized, dose‐escalation trial and received IV rhASA at 50, 100, or 200 U/kg body weight every 14 (± 4) days for 52 weeks (NCT00418561; NCT00633139). Eleven children continued to receive rhASA at 100 or 200 U/kg during a 24‐month extension period (NCT00681811). Outcome measures included safety observations, changes in motor and cognitive function, and changes in nerve conduction and morphometry.

Results

There were no serious adverse events considered related to IV rhASA. Motor function and developmental testing scores declined during the study in all dose groups; no significant differences were observed between groups. Nerve conduction studies and morphometric analysis indicated that peripheral nerve pathology did not worsen during the study in any dose group.

Interpretation

IV rhASA was generally well tolerated. There was no evidence of efficacy in preventing motor and cognitive deterioration, suggesting that IV rhASA may not cross the blood–brain barrier in therapeutic quantities. The relative stability of peripheral nerve function during the study indicates that rhASA may be beneficial if delivered to the appropriate target site and supports the development of rhASA for intrathecal administration in MLD.
Robust tracking of moving objects using thermal camera and speeded up robust features descriptor
Authors: Vlahović Nataša , Djurovic Zeljko
Published: December 2020

Robust methods based on nonlinear influence functions are often used to remove outliers from data. The article describes the design of an algorithm for tracking a moving object in a thermal image using a SURF descriptor and robust Kalman filter. However, given that the main shortfall of robust methods is reduced efficiency, tunable parameters of the robust influence function are used to achieve a balance between robustness and efficiency. The parameters adapt to the observed scene's current conditions, while their estimation is based on the calculated data outlier contamination factor. The outliers that contaminate the data are generally a result of various types of occlusions. The results show that the proposed solution achieves better performance than the standard Kalman filter or fixed‐parameter robust Kalman filter.
Electrochemical Mg2+ Displacement Driven Reversible Copper Extrusion/Intrusion Reactions for High‐Rate Rechargeable Magnesium Batteries
Authors: Xue Xiaolan , Chen Renpeng , Song Xinmei , Tao Anyang , Yan Wen , Kong Weihua , Jin Zhong
Published: December 2020

Rechargeable magnesium batteries (RMBs) based on metal Mg anodes have shown great potential owing to the abundant natural resources, high volumetric capacity, and low safety hazard. Nevertheless, the development of RMBs is hampered by the sluggish kinetics of Mg2+ diffusion and the limited cyclability of cathode materials. Herein, nonstoichiometric copper selenide (Cu2–xSe) are synthesized via a solution‐based method and exploited as a durable cathode material based on ionic displacement mechanism for RMBs. The copper ions in the Se2− based sub‐lattices are reversibly exchanged by Mg2+ ions without causing lattice collapse. Owing to the same face‐centered cubic Se2− sub‐lattices and similar unit cell size of Cu2–xSe and MgSe, the energy barrier for lattice reconstruction during cycling processes is very low, significantly improving the rate performance, structural stability, and cycle life of the Cu2–xSe cathode. Moreover, metal Cu is in situ generated during discharging, thus greatly facilitating electron transport. Comprehensive characterizations confirm that the Cu2–xSe cathode undergoes reversible copper ion extrusion/reinjection during the discharge−charge steps. This work suggests the great potential for exploring high‐performance electrode materials based on ionic displacement mechanism for advanced multivalent‐ion secondary batteries.