bluuebunny/crossref_metadata_2025 huggingface dataset:
Isolation of tissue‐type plasminogen activator, cathepsin H, and non‐specific cross‐reacting antigen from SK‐PC‐1 pancreas cancer cells using subtractive hybridization
Authors: Paciucci Rosanna , Berrozpe Georgina , Torà Montserrat , Navarro Estanis , García de Herreros Antonio , Real Francisco X.
Published: July 2002

We have used subtractive hybridization to isolate cDNAs overexpressed in SK‐PC‐1 pancreas cancer cells. Fortyfive independent clones corresponding to 11 genes were identified. Their expression in cultured pancreas cancer cells, normal pancreas tissue, and normal exocrine pancreas cultures was examined by Northern blotting. cDNA clones can be grouped into two broad categories: (1) those corresponding to genes expressed at high levels both in tumor cell lines and in primary cultures of normal pancreas, but not in normal tissue (i.e. thymosin β43,, cytokeratin 18, β‐actin, pyruvate kinase and mitochondrial genes); and (2) those corresponding to genes expressed at high levels in pancreas cancer cultures but not in normal pancreas tissue or cultured cells (i.e. tissue‐type plasminogen activator and cathepsin H). The overexpression of these proteases in pancreas cancers suggests that they play a role in the aggressive biological behavior of this tumor.
The Escherichia coli trigger factor
Authors: Hesterkamp Thomas , Bukau Bernd
Published: July 2002

E. coli trigger factor is an abundant cytosolic protein originally iDAntified by its ability to maintain the precursor of a secretory protein in a translocation competent form. Recent studies shed new light on the function of this protein. Trigger factor was found to be a peptidyl‐prolyl‐cisltrans‐isomerase capable of catalysing protein folding in vitro, to associate with nascent cytosolic and secretory polypeptiDA chains, and to cooperate with the GroEL chaperone in promoting proteolysis of an unstable polypeptiDA in vivo. These findings suggest roles for trigger factor in various folding processes of secretory as well as cytosolic proteins.
Tyrosine phosphorylation is crucial for growth signaling by tissue inhibitors of metalloproteinases (TIMP‐1 and TIMP‐2)
Authors: Yamashita Kyoko , Suzuki Mitsunori , Iwata Hiroyuki , Koike Teruhiko , Hamaguchi Michinari , Shinagawa Akira , Noguchi Toshihide , Hayakawa Taro
Published: July 2002

[3H]Thymidine (TdR) incorporation by human osteosarcoma cell line MG‐63 was significantly stimulated at as early as 3 h after the addition of either TIMP‐1 or TIMP‐2 alone. Maximum stimulation was attained at a concentration of either 20 ng/ml (0.71 nM) TIMP‐1 or 1.0 ng/ml (46 pM) TIMP‐2. Tyrosine kinase inhibitors such as genistein, erbstatin, and herbimycin A almost completely inhibited the [3H]TdR incorporation stimulated by either of the TIMPs. However, essentially no effect was observed with H‐89, H‐7, bisindolylmaleimide and K‐252a. These inhibition studies suggest a crucial role for tyrosine kinase in the signal transduction of TIMPs. Phosphotyrosine‐containing proteins were significantly elevated by the treatment with both TIMPs. We also found that either TIMP stimulated an increase in mitogen‐activated protein (MAP) kinase activity, suggesting that MAP kinase plays a role in TIMP‐dependent growth signaling.
Oral nifedipine therapy in the management of severe preeclampsia
Authors: Kwawukume E.Y. , Ghosh T.S.
Published: July 2002

Objective: The purpose of this study was to compare the efficacy of nifedipine (Cordipin) and hydralazine in lowering blood pressure in severe preeclampsia. Method: A randomized, prospective study of 104 patients with severe preeclampsia in the Department of Obstetrics and Gynecology, Korle‐Bu Teaching Hospital, Accra, Ghana, was conducted between January 1992 and June 1994. Results: Of the 104 patients recruited into the study, six did not deliver at our hospital and were thus excluded from the study. Nifedipine and hydralazine as first‐line drugs controlled the blood pressure in 44 and 35 patients, respectively, but failed in 5 and 14, respectively. This was statistically significant (P < 0.05). The mean birth weight was higher in the nifedipine group (2500 ± 800 g vs. 2400 ± 800 g). There were 11 admissions to the neonatal intensive care unit in the nifedipine group and 13 in the hydralazine group but the difference was not statistically significant. Conclusion: Nifedipine and hydralazine could both be used effectively to control blood pressure in severe preeclampsia in our subregion. While hydralazine is administered intravenously and needs strict monitoring, nifedipine is more effective, is easy to administer orally, less demanding on hospital staff, convenient and more predictable.
Interleukin‐1 alpha and vasoactive interstinal peptide: Enigmatic regulation of neuronal survival
Authors: Brenneman D.E. , Hill J.M. , Glazner G.W. , Gozes I. , Phillips T.W.
Published: July 2002

A neurotrophic role for interleukin‐1 alpha (IL‐1α) was investigated in dissociated spinal cord‐dorsal root ganglion cultures. Three observations suggested a survival‐promoting action for IL‐1α in nine‐day‐old cultures: (1) neutralizing antiserum to murine IL‐1α decreased neuronal survival; (2) treatment with IL‐1α in electrically blocked cultures increased neuronal survival; and (3) antiserum to the type I IL‐1 receptor decreased neuronal survival. Treatment with VIP prevented neuronal cell death associated with the antiserum to IL‐1α. In contrast, treatment of one‐month‐old cultures with IL‐1α produced neuronal cell death and neutralizing antiserum to the IL‐1 receptor had no effect on neuronal survival in these cultures. These experiments suggested that an IL‐1‐like substance was necessary for neuronal survival during a specific stage in development and that a relationship between VIP and IL‐1α might account in part for the neurotrophic properties of VIP.

To test if VIP might be a secretagogue for IL‐1, a neuron‐free model system was utilized: astroglial cultures derived from cerebral cortex. VIP treatment produced a concentration‐dependent (EC50:50 pM) increase in the amount of IL‐1α in the medium and a decrease in cellular IL‐1α. Interleukin‐1 beta (IL‐1β) was also increased (EC 50: 1 nM) in the medium by VIP but without depleting IL‐1β in the cytosol. Semi‐quantitative measurements of the IL‐1α mRNA after VIP treatment indicated a significant but transient decrease. These data indicate that VIP produced an increase in the secretion of IL‐1α while depleting IL‐1α mRNA.
Ser727‐dependent transcriptional activation by association of p300 with STAT3 upon IL‐6 stimulation
Authors: Schuringa Jan-Jacob , Schepers Hein , Vellenga Edo , Kruijer Wiebe
Published: July 2002

Activation of the signal transducer and activator of transcription 3 (STAT3) in response to interleukin‐6 (IL‐6) type cytokines involves both phosphorylation of Tyr705, which enables dimerization, nuclear translocation and DNA binding, as well as ser727 phosphorylation. Here, we describe that the 65 C‐terminal amino acids of STAT3 can function as an independent transcription activation domain (TAD), particularly when a negative charge is introduced at position 727 by mutation of the serine residue into aspartate. The strong transcriptional activity of the C‐terminal STAT3 Ser727Asp TAD is coupled to a constitutive association with the co‐activator p300. In HepG2 cells, p300 associates with STAT3 upon IL‐6 stimulation, and overexpression of p300 enhances the transcriptional activity of STAT3α, but not of STAT3β or STAT3 Ser727Ala. We conclude that Ser727 phosphorylation in the C‐terminal region of STAT3 is required for transactivation by association with p300.
Chemical shift mapping of shikimate‐3‐phosphate binding to the isolated N‐terminal domain of 5‐enolpyruvylshikimate‐3‐phosphate synthase
Authors: Stauffer Melissa E. , Young John K. , Helms Gregory L. , Evans Jeremy N.S.
Published: July 2002

To facilitate evaluation of enzyme–ligand complexes in solution, we have isolated the 26‐kDa N‐terminal domain of 5‐enolpyruvylshikimate‐3‐phosphate (EPSP) synthase for analysis by NMR spectroscopy. The isolated domain is capable of binding the substrate shikimate‐3‐phosphate (S3P), and this letter reports the localization of the S3P binding site using chemical shift mapping. Based on the NMR data, we propose that Ser23, Arg27, Ser197, and Tyr200 are directly involved in S3P binding. We also describe changes in the observed nuclear Overhauser effects (NOEs) that are consistent with a partial conformational change in the N‐terminal domain upon S3P binding.
Role of thioltransferases on the modulation of rat liver S‐adenosylmethionine synthetase activity by glutathione
Authors: Martinez-Chantar María L. , Pajares Maria A.
Published: July 2002

Rat liver S‐adenosylmethionine synthetase, high‐ and low‐M
r forms, are regulated in vitro by the GSH/GSSG ratio at pH 8. The inhibition and oxidation constants for both forms have been calculated in the presence of thioltransferases. The mechanism of the reaction appeared to involve the formation of intramolecular disulfides. Increases of 3‐ to 4‐fold in the oxidation constants for both S‐adenosylmethionine synthetase isoenzymes in the presence of protein disulfide isomerase suggested the possibility of a thiol‐disulfide exchange regulatory mechanism for this enzyme in vivo. The significance of these results is discussed on the light of the data available relating glutathione changes and modulation of enzyme activities, either in vivo and in vitro.
Aeration‐dependent changes in composition of the quinone pool in Escherichia coli
Authors: Shestopalov Alexander I. , Bogachev Alexander V. , Murtazina Rakhilya A. , Viryasov Mikhail B. , Skulachev Vladimir P.
Published: July 2002

© 1997 Federation of European Biochemical Societies.
Essential role of Rac GTPase in hydrogen peroxide‐induced activation of c‐fos serum response element
Authors: Kim Jae-Hong , Kwack Hee-Jin , Choi Sung-E , Kim Byung-Chul , Kim Yong-Sun , Kang Il-Jun , Kumar Chandra C.
Published: July 2002

In the present study, we investigated whether hydrogen peroxide activates c‐fos serum response element (SRE) in Rat‐2 fibroblast cells. By transient transfection analysis, exogenous H2O2 stimulated SRE‐dependent reporter gene activity in a dose and time‐dependent manner. Also, we examined the role of Rac GTPase and phospholipase A2 (PLA2) in the H2O2‐induced SRE activation. Either transfection of a dominant negative Rac mutant, RacN17, plasmid or pretreatment of mepacrine, a potent inhibitor of PLA2, blocked H2O2‐induced SRE activation dramatically. Together, these findings suggest a critical role of ‘Rac and subsequent activation of phospholipase A2’ in the signaling pathway of H2O2 to SRE.
A structural tree for proteins containing 3β‐corners
Authors: Efimov A.V.
Published: July 2002

A structural tree for β‐proteins with predominantly orthogonal β‐sheet packing has been constructed. The 3β‐corner, a structural motif that recurs in proteins of this class, is taken as a root structure of the tree. The 3β‐corner can be represented as a triple‐stranded β‐sheet folded on to itself so that its two β‐β‐hairpins are packed approximately orthogonally in different layers and the central strand bends by ∼90° in a right‐handed direction when passing from one layer to the other. The larger protein structures are obtained by stepwise addition of β‐strands to the root 3β‐corner taking into account a restricted set of rules inferred from known principles of protein structure. The protein structures that can be obtained in this way are grouped into one structural class and those found in branches of the structural tree into subclasses.
K+ is an indispensable cofactor for GrpE stimulation of ATPase activity of DnaK·DnaJ complex from Thermus thermophilus
Authors: Motohashi Ken , Yohda Masafumi , Odaka Masafumi , Yoshida Masasuke
Published: July 2002

K+ is an indispensable cofactor for ATPase activity of eukaryotic cytosolic Hsp70 chaperone systems which lack a GrpE homolog. In the case of the bacterial Hsp70 (DnaK) system, GrpE, a nucleotide exchange factor, stimulates ATPase activity but little is known about the effect of K+. Here, we have cloned a grpE gene from a thermophile, Thermus thermophilus, and purified a homodimeric GrpE protein. Using proteins of this bacterium, we found that the GrpE stimulation of ATPase activity of DnaK·DnaJ complex was absolutely dependent on the presence of K+.
Transient expression of botulinum neurotoxin C1 light chain differentially inhibits calcium and glucose induced insulin secretion in clonal β‐cells
Authors: Lang Jochen , Zhang Hui , Vaidyanathan Vadakkanchery-Viswanathan , Sadoul Karin , Niemann Heiner , Wollheim Claes B
Published: July 2002

We have investigated the effect of botulinum neurotoxin (BoNT) C1 light chain (LC) on insulin exocytosis from the clonal β‐cell line HIT‐T15. In streptolysin‐O permeabilized cells, the β‐cell impermeant BoNT C1 cleaved mainly syntaxin 1 and inhibited Ca2+ as well as GTPγS induced exocytosis. To study the effect of BoNTs in intact cells, we transiently coexpressed the BoNT LC together with a reporter gene for insulin release. BoNT C1 inhibited K+ induced insulin secretion by 95% but reduced insulin release stimulated by glucose only by 25%. Thus a component of glucose stimulated insulin release is insensitive to BoNT C1.
Three kinds of binding site for tentoxin on isolated chloroplast coupling factor 1
Authors: Mochimaru Mari , Sakurai Hidehiro
Published: July 2002

Tentoxin binding on chloroplast coupling factor 1 (CF1) was studied using a centrifugation column method followed by HPLC analysis. From non‐linear regression analysis of the results, the presence of three types of binding site with the following K
d values was deduced: 6.9×10−8 M (first site), 1.4×10−5 M (second site), and 6.3×10−3 M (third site). The binding of one tentoxin inhibits, that of two tentoxins moderately restores, and that of three tentoxins greatly stimulates the ATPase activity of CF1. The forward rate constant of the binding of tentoxin on the first site was 6.3×103 M−1 s−1.
Lipid membrane binding of NK‐lysin
Authors: Ruysschaert Jean-Marie , Goormaghtigh Erik , Homblé F , Andersson Mats , Liepinsh Edvards , Otting Gottfried
Published: July 2002

The membrane‐binding properties and pore‐forming potential of the tumor‐lysing and antibacterial polypeptide NK‐lysin were investigated. Fluorescence quenching experiments show a drastic change of accessibility to Trp58 in solution and in association with a lipid membrane. Calcein release from large unilamellar vesicles and fluctuating conductivity observed across a planar lipid bilayer of asolectin show that NK‐lysin renders lipid bilayers permeable in a transient fashion, indicating a non‐specific lipid interaction as the mechanism underlying the biological activity. FTIR experiments show the same amount and type of regular secondary structure of NK‐lysin in the membrane as in aqueous solution and exclude a structural rearrangement into a set of parallel or antiparallel α‐helices as the predominant conformation. The molecular mechanism of the membrane‐destabilizing effect of NK‐lysin is discussed.
3‐Aminobenzamide inhibition of protein kinase C at a cellular level
Authors: Ricciarelli Roberta , Palomba Letizia , Cantoni Orazio , Azzi Angelo
Published: July 2002

3‐Aminobenzamide, a known inhibitor of poly‐(ADP‐ribose)‐polymerase has been found in the cell line U‐937 to inhibit protein kinase C at the same concentration as poly‐(ADP‐ribose)‐polymerase. 3‐Aminobenzamide was not able, however, to inhibit the isolated enzyme. An indirect mechanism of protein kinase C inhibition is proposed.
Identification of a novel human homolog of the Drosophila dlg, P‐dlg, specifically expressed in the gland tissues and interacting with p55
Authors: Nakamura Hideo , Sudo Tamotsu , Tsuiki Hiromasa , Miyake Hideaki , Morisaki Tetsuro , Sasaki Ji-ichiro , Masuko Norio , Kochi Masato , Ushio Yukitaka , Saya Hideyuki
Published: July 2002

We have identified a novel human homolog of the Drosophila dlg tumor suppressor gene, termed P‐dlg, which has been mapped at chromosome 10q23. Unlike other human dlg homologs, P‐dlg is expressed in placenta and various gland tissues but not in brain. The P‐dlg protein is localized at the plasma membrane and cytoplasm, and it is expressed in the gland epithelial cells in normal prostate tissue but not in prostate cancer cell lines. Furthermore, we identified interaction between P‐dlg and p55 palmitoylated membrane protein by yeast two‐hybrid screening. These findings suggest that P‐dlg forms a complex with p55 at the plasma membrane and plays roles in maintaining the structure of epithelial cells and transmitting extracellular signals to the membrane and cytoskeleton, which may negatively regulate cell proliferation.
Electroporation‐mediated gene transfer in cardiac tissue
Authors: Harrison Rachel L , Byrne Barry J , Tung Leslie
Published: July 2002

Delivery of genes or macromolecules to cardiovascular tissues provides new therapeutic opportunities for the treatment of many acquired and inherited diseases. To investigate electroporation as a delivery method in cardiac tissue, embryonic chick hearts were studied for uptake of propidium iodide (PI) or DNA encoding either green fluorescent protein (GFP) or luciferase following electrical shock. PI uptake increased monotonically from 6% of heart tissue after 3 shocks to 77% with 12 shocks. GFP and luciferase expression varied in proportion to shock number, with detectable levels in all electrically treated hearts. Thus, electroporation promotes uptake of PI and DNA in cardiac tissue, suggesting further application of this method for therapeutic genes.
Characterization of a heavy metal ion transporter in the lysosomal membrane
Authors: Havelaar Adrie C , de Gast Izaäk L , Snijders Saskia , Beerens Cecile E.M.T , Mancini Grazia M.S , Verheijen Frans W
Published: July 2002

Lysosomes are thought to play a role in various aspects of heavy metal metabolism. In the present study we demonstrate for the first time the presence of a heavy metal ion transport protein in the lysosomal membrane. Uptake of radioactive silver both in highly purified lysosomal membrane vesicles and in purified intact lysosomes showed the typical kinetics of a carrier‐mediated process. This transport was stimulated by ATP hydrolysis, and showed specificity for Ag+, Cu2+, and Cd2+. All biochemical properties of this lysosomal metal ion transporter could classify it as a heavy metal transporting P‐type ATPase. Long Evans Cinnamon (LEC) rats, an animal model for the copper transport disorder Wilson disease, showed normal lysosomal silver transport.
Protein phosphatase type 2C active at physiological Mg2+: stimulation by unsaturated fatty acids
Authors: Klumpp Susanne , Selke Dagmar , Hermesmeier Jan
Published: July 2002

Type 2C serine/threonine protein phosphatases (PP2C) so far require unphysiologically large amounts of Mg2+ ions for activity. Activators and inhibitors are not available, targeting subunits unknown. Studying the regulation of PP2C isozymes in bovine retinae, we found that the activity of PP2C increased specifically by the addition of mono‐ and polyunsaturated fatty acids. Activation was most pronounced at low Mg2+ levels (10‐fold stimulation of PP2Cα by 0.5 mM arachidonic acid at 0.7 mM Mg2+). Sensitivity of PP2Cβ was 30–50% less, revealing for the first time enzymatic differences among the PP2C isozymes. Combining unsaturated fatty acids with physiological Mg2+ concentrations resulted in PP2C activity that by far exceeded the dephosphorylation rates obtained otherwise. This suggests that PP2C activity has been severely underestimated in the past. In the presence of fatty acids, Ca2+ ions became inhibitory in the micromolar range. We conclude that unsaturated fatty acids may play a role in the regulation of PP2C activity.
Selective conservation of an E‐protein gene promoter during vertebrate evolution
Authors: Shain Daniel H. , Zuber Mauricio X. , Norris Jeff , Yoo Jakyoung , Neuman Toomas
Published: July 2002

The murine E‐protein gene ME1 encodes a non‐tissue‐specific, helix‐loop‐helix transcription factor that is associated with morphological development. ME1 gene expression is regulated by a TATA‐less promoter that contains multiple Sp1 consensus elements, E‐boxes, and a novel transcription initiation site. In this study, we compared DNA homologous to the ME1 promoter from vertebrate species ranging from frog to human. A region of striking sequence similarity was identified in a region corresponding to the ME1 transcription initiation site (ME1 Inr). Within this region, a poly d(A) tract and a 9‐bp inverted repeat (5′‐GTCCGCCTG) were highly conserved in all species that were examined. Protein complexes that recognized these DNA elements were present among distant vertebrates (frog, chick, monkey and human), and were able to bend the ME1 Inr to a similar extent (∼60°) as the previously described murine MBPα and MBPβ proteins. Collectively, these results suggest that an ME1 Inr‐like element and its associated proteins functioned in an ancestral vertebrate more than 350 million years ago.
Biochemical evidence that the N‐terminal segments of the α subunit and the β subunit play interchangeable roles in the activation of protein kinase CK2
Authors: Sarno Stefania , Marin Oriano , Ghisellini Paola , Meggio Flavio , Pinna Lorenzo A
Published: July 2002

The concept that the amino‐terminal segment plays a role in conferring high basal activity to protein kinase CK2 α subunit has been validated by generating two mutants (Y26F and Δ2–6) which are defective both in catalytic activity and in thermal stability. The additional finding that the activity of the two mutants is fully restored upon association with the regulatory β subunit, in conjunction with the observation that synthetic peptides reproducing the N‐terminal segment (1–30) and the activation loop (175–201) of CK2α counteract the functional effects of the C‐terminal domain of the β subunit, is consistent with a mechanism of activation of CK2 where the N‐terminal domain of α and the C‐terminal domain of β play interchangeable roles.
Accessibility of selenomethionine proteins by total chemical synthesis: structural studies of human herpesvirus‐8 MIP‐II
Authors: Shao Weiping , Fernandez Elias , Wilken Jill , Thompson Darren A , Siani Michael A , West John , Lolis Elias , Schweitzer Barry I
Published: July 2002

The determination of high resolution three‐dimensional structures by X‐ray crystallography or nuclear magnetic resonance (NMR) is a time‐consuming process. Here we describe an approach to circumvent the cloning and expression of a recombinant protein as well as screening for heavy atom derivatives. The selenomethionine‐modified chemokine macrophage inflammatory protein‐II (MIP‐II) from human herpesvirus‐8 has been produced by total chemical synthesis, crystallized, and characterized by NMR. The protein has a secondary structure typical of other chemokines and forms a monomer in solution. These results indicate that total chemical synthesis can be used to accelerate the determination of three‐dimensional structures of new proteins identified in genome programs.
Up‐regulation of nuclear protein import by nuclear localization signal sequences in living cells
Authors: Tachibana Taro , Hieda Miki , Yoneda Yoshihiro
Published: July 2002

Using an in vivo assay system, nuclear import ability in individual cells was determined by examining the nuclear import rate. It was found that when a small (not excess) amount of SV40 T‐NLS peptides was co‐injected, the nuclear import rate of SV40 T‐NLS‐containing substrates apparently increased. This up‐regulation was reproduced by the co‐injection of peptides containing bipartite type NLS of CBP80, but not mutated non‐functional NLS peptides, which suggests that these phenomena are specific for functional NLSs. It was further shown that although, in growth‐arrested cells, the nuclear import rate was down‐regulated compared to growing cells, the elevation of the functional import rate by co‐injected NLS peptides reached the same level as in proliferating cells. This up‐regulation was abolished by the addition of a protein kinase inhibitor, staurosporine. These results suggest that although potential nuclear import ability does not vary in each cell, the rate of nuclear import may be controlled by the amount of karyophilic proteins, which need to be carried into the nucleus from the cytoplasm, possibly via an NLS‐dependent phosphorylation reaction.
Mutational analysis of two Arabidopsis thaliana cyclin‐dependent kinases in fission yeast
Authors: Porceddua, Andrea , De Veyldera Lieven , Hayles Jacky , Van Montagu Marc , Inzé Dirk , Mironov Vladimir
Published: July 2002

We have analyzed five mutant alleles of two cyclin‐dependent kinases from Arabidopsis thaliana, CDC2aAt and CDC2bAt, in Schizosaccharomyces pombe. Two of the five mutant alleles produced similar phenotypes for both cyclin‐dependent kinases. The other three mutants caused phenotypes dependent on the particular cyclin‐dependent kinase. Of all the mutant alleles, only two were found to possess a detectable kinase activity. Our mutational analysis lends further support for CDC2aAt being the true orthologue of the yeast cdc2. CDC2bAt, even though quite divergent from S. pombe cdc2, still retains the ability to interact with at least some essential cell cycle regulators, suggesting some functional homology with the yeast protein. Additionally, we demonstrated that the three amino acid deletion in the DL50 mutants results in the loss of the ability to interact with the suc1/CKS1 proteins.
Hypochlorite modification of high density lipoprotein: effects on cholesterol efflux from J774 macrophages
Authors: Bergt Constanze , Reicher Helga , Malle Ernst , Sattler Wolfgang
Published: July 2002

The present study was aimed at investigating effects of hypochlorite (HOCl) modification of high density lipoproteins subclass 3 (HDL3) on their ability for cellular cholesterol removal from permanent J774 macrophages. Our findings indicate that HOCl (added as reagent or generated enzymatically by the myeloperoxidase/H2O2/Cl− system) damages apolipoprotein A‐I, the major protein component of HDL3. Fatty acid analysis of native and HOCl‐modified HDL3 revealed that unsaturated fatty acids in both major lipid subclasses (phospholipids and cholesteryl esters) are targets for HOCl attack. HOCl modification resulted in impaired HDL3‐mediated cholesterol efflux from J774 cells, regardless of whether reagent or enzymatically generated HOCl was used to modify the lipoprotein. Decreased cholesterol efflux was also observed after HOCl modification of reconstituted HDL particles. Impairment of cholesterol efflux from macrophages was noticed at low and physiologically occurring HOCl concentrations.
N‐Acetyl‐sphingenine‐1‐phosphate is a potent calcium mobilizing agent
Authors: Gijsbers Sofie , Mannaerts Guy P. , Himpens Bernard , Van Veldhoven Paul P.
Published: July 2002

Calcium mobilization induced by phosphorylated sphingoid bases was analyzed in calf pulmonary artery endothelial cells by confocal microscopy. A sphingenine‐1‐phosphate (SeP) analogue, N‐acetyl‐sphingenine‐1‐phosphate (N‐C2‐SeP), exogenously added to these cells, caused a fast and transient intracellular rise in calcium and was as potent as SeP. A minimal concentration of 0.6 nM for N‐C2‐SeP versus 1 nM for SeP was determined. The N‐C2‐SeP‐induced Ca2+‐signaling, like the response to SeP, was due to a release from thapsigargin‐sensitive, ryanodine‐insensitive, intracellular Ca2+‐stores and not to a Ca2+‐influx. N‐C2‐SeP can be considered as a truncated ceramide‐phosphate, a lipid already reported to be mitogenic (Gomez‐Munoz, A., Duffy, P.A., Martin, A., O'Brien, L., Byun, H.S., Bittman, R. and Brindley, D.N. (1995) Mol. Pharmacol. 47, 833–839), an effect that might be secondary to Ca2+‐mobilization.
Molecular characterization and immunolocalization of Dictyostelium discoideum protein phosphatase 2A
Authors: Murphy M.B. , Levi S.K. , Egelhoff T.T.
Published: July 2002

Protein phosphatase 2A (PP2A) was previously purified from Dictyostelium and biochemically characterized. The purified PP2A holoenzyme was composed of a 37 kDa catalytic ‘C‐subunit’, a 65 kDa ‘A‐subunit’ and a 55 kDa ‘B‐subunit’. We report here the characterization of the genes encoding the Dictyostelium PP2A subunits as well as the immunolocalization of the PP2A subunits in Dictyostelium. The cDNAs encoding the B‐ and C‐subunits were isolated from a Dictyostelium library and the deduced amino acid sequences reveal strong conservation with the mammalian PP2A homologues. Southern blot analysis suggests that each of the PP2A subunit genes is present in a single copy. The PP2A subunits were localized mainly to the cytosol in Dictyostelium cells. However, immunofluorescence confocal microscopy demonstrates that the B‐subunit of PP2A is highly enriched in centrosomes, suggesting a potential role for this PP2A regulatory subunit in the centrosomal function.
Activation of PPARγ inhibits cell growth and induces apoptosis in human gastric cancer cells
Authors: Takahashi Nobuhiko , Okumura Toshikatsu , Motomura Wataru , Fujimoto Yoshinori , Kawabata Isao , Kohgo Yutaka
Published: July 2002

We investigated the expression of peroxisome proliferator‐activated receptor γ (PPARγ) and the role of PPARγ in cell growth in human gastric cancer cells. Reverse transcription‐polymerase chain reaction, Northern blot and Western blot analyses showed that a human gastric cancer cell line, MKN45, expressed PPARγ mRNA and protein. Luciferase assay in MKN45 cells showed that troglitazone, a selective ligand for PPARγ, transactivated the transcription of a peroxisome proliferator response element‐driven promoter. Troglitazone or pioglitazone, selective ligands for PPARγ, inhibited the growth of MKN45 cells in a dose‐dependent manner. Co‐incubation of MKN45 cells with troglitazone induced DNA ladder formation. These results suggest that human gastric cancer cells express PPARγ and that activation of PPARγ inhibits cell growth and induces apoptosis in gastric cancer cells.
Calmodulin inhibits inositol 1,4,5‐trisphosphate‐induced calcium release through the purified and reconstituted inositol 1,4,5‐trisphosphate receptor type 1
Authors: Hirota Junji , Michikawa Takayuki , Natsume Tohru , Furuichi Teiichi , Mikoshiba Katsuhiko
Published: July 2002

Our previous studies have demonstrated that calmodulin binds to IP3R type 1 (IP3R1) in a Ca2+ dependent manner, which suggests that calmodulin regulates the IP3R1 channel. In the present study, we investigated real‐time kinetics of interactions between calmodulin and IP3R1 as well as effects of calmodulin on IP3‐induced Ca2+ release by purified and reconstituted IP3R1. Kinetic analysis revealed that calmodulin binds to IP3R1 in a Ca2+ dependent manner and that both association and dissociation phase consist of two components with time constants of k
a=4.46×102 and >104 M−1 s−1, k
d=1.44×10−2 and 1.17×10−1 s−1. The apparent dissociation constant was calculated to be 27.3 μM. The IP3‐induced Ca2+ release through the purified and reconstituted IP3R1 was inhibited by Ca2+/calmodulin, in a dose dependent manner. We interpret our findings to mean that calmodulin binds to IP3R1 in a Ca2+ dependent manner to exert inhibitory effect on IP3R channel activity. This event may be one of the mechanisms governing the negative feedback regulation of IP3‐induced Ca2+ release by Ca2+.
Altered binding of mutated presenilin with cytoskeleton‐interacting proteins1
Authors: Johnsingh Amit A. , Johnston Jane M. , Merz George , Xu Jiliu , Kotula Leszek , Jacobsen J.Steven , Tezapsidis Nikolaos
Published: July 2002

The majority of familial Alzheimer's disease (AD) cases are linked to mutations on presenilin 1 and 2 genes (PS1 and PS2). The normal function of the proteins and the mechanisms underlying early‐onset AD are currently unknown. To address this, we screened an expression library for proteins that bind differentially to the wild‐type PS1 and mutant in the large cytoplasmic loop (PS1L). Thus we isolated the C‐terminal tail of the 170 kDa cytoplasmic linker protein (CLIP‐170) and Reed–Sternberg cells of Hodgkin's disease‐expressed intermediate filament‐associated protein (Restin), cytoplasmic proteins linking vesicles to the cytoskeleton. PS1L binding to CLIP‐170/restin requires Ca2+. Treating cells with thapsigargin or ionomycin increased the mutated PS1 in CLIP‐170 immunoprecipitates. Further, PS1 and CLIP‐170 co‐localize in transfected cells and neuronal cultures.
Adjunctive testing for cervical cancer in low resource settings with visual inspection, HPV, and the Pap smear
Authors: Blumenthal P.D. , Gaffikin L. , Chirenje Z.M. , McGrath J. , Womack S. , Shah K.
Published: July 2002

Objective: To test whether the performance of visual inspection using acetic acid (VIA) could be improved through adjunctive testing and to determine whether the combination of visual inspection of the cervix and HPV testing could prove useful for identifying those at highest risk of cervical precancer. Methods: Between October 1995 and August 1997, 2199 women willing to be screened for cervical cancer in peri‐urban clinics in Harare, Zimbabwe received VIA, Pap smear and HPV as screening tests. The presence or absence of (pre)cancer was confirmed via colposcopy with biopsy as indicated for >97% of all women. Computerized simulations of sequential testing scenarios provided estimates of the joint (net) test qualities of different paired combinations of the three tests and allowed for comparisons with the individual test qualities. Results: Using HGSIL/CIN II‐III as the reference threshold of disease, the net sensitivity and specificity of VIA and HPV when used sequentially were 63.6 and 81.9%, respectively, compared to 43.3 and 91%, respectively, when Pap smears were followed by HPV testing. VIA followed by the Pap smear yielded a net sensitivity of 37.5% and net specificity of 94.3%. Conclusions: For programs with limited resources but with the capacity for HPV testing, sequential testing involving the use of VIA followed by HPV could yield fewer false positives than the use of VIA alone at a cost of relatively few additional false negatives.
The pathway of MAP kinase mediation of CSF arrest in Xenopus oocytes
Authors: Maller James L. , Schwab Markus S. , Roberts B.Tibor , Gross Stefan D. , Taieb Frédéric E. , Tunquist Brian J.
Published: July 2002

Summry— A cytoplasmic activity in mature oocytes responsible for second meiotic metaphase arrest was identified over 30 years ago in amphibian oocytes.  In Xenopus oocytes CSF activity is initiated by the progesterone‐dependent synthesis of Mos, a MAPK kinase kinase, which activates the MAPK pathway.  CSF arrest is mediated by a sole MAPK target, the protein kinase p90Rsk which leads to inhibition of cyclin B degradation by the anaphase‐promoting complex.  Rsk phosphorylates and activates the Bub1 protein kinase, which may cause metaphase arrest due to inhibition of the anaphase‐promoting complex (APC) by a conserved mechanism defined genetically in yeast and mammalian cells.  CSF arrest in vertebrate oocytes by p90Rsk provides a potential link between the MAPK pathway and the spindle assembly checkpoint in the cell cycle.
Postnatal development of interlaminar astroglial processes in the cerebral cortex of primates
Authors: Colombo J.A. , Lipina S. , YáÑez A. , Puissant V.
Published: July 2002

Long astroglial processes traversing several cortical laminae appear to be characteristic of primate brains. Whether interlaminar processes develop as a modification of radial glia or are truly postnatal elements stemming from stellate astroglia, could be assessed by analyzing their early developmental stages. A survey of glial fibrillar acidic protein immunoreactive (GFAP‐IR) astroglial interlaminar processes in the cerebral cortex of Ceboidea monkeys at various postnatal developmental ages, and in human cortical samples of a ten day and a seven year old child disclosed that such processes develop postnatally. At one month of age GFAP‐IR interlaminar processes in monkeys were scarce and short in most frontal, parietal or occipital (striate) cortical areas, except for sulcal (principal and orbital sulci) and temporal cortical areas. Some processes were weakly positive for vimentin, and these were most abundant in ventral temporal cortical areas. At two months of age processes were present in all these areas, albeit in restricted patches and significantly shorter than in adults. The expression of this pattern was increased at seven months of age. At three years of age almost every area showed abundant processes and with lengths comparable to the adult Ceboidea individuals. In humans, at 10 days of age long interlaminar processes were readily apparent in a frontal cortex sample, becoming most apparent at the age of seven years although not reaching yet the adult characteristics as described previously. Conclusions : (1) GFAP‐IR interlaminar processes develop postnatally, thus typifying a subtype of the classical stellate forms ; (2) they bear no obvious direct relationship with radial glia ; (3) their development is not contemporary among the various cortical regions. These long cellular processes represent an addition to those already described for other astroglial cell types in the adult mammalian brain (Golgi–Bergmann glia, tanicytes, Muller cells) .
Tissue‐specific alternative mRNA splicing ofphenylethanolamine n‐methyltransferase (PNMT) duringdevelopment by intron RETENTION
Authors: Unsworth Brian R. , Hayman G.Thomas , Carroll Amie , Lelkes Peter I.
Published: July 2002

The expression of phenylethanolamine N‐methyl transferase (EC 2. 1.1.2.8,PNMT), the final enzyme in the cascade of catecholamine synthesis, is differentially regulated inadrenergic neurons in the brain and in adrenal chromaffin cells. Using reversetranscription‐polymerase chain reaction‐based techniques, we detected in the prenatal developingrat brainstem, two species of PNMT mRNA which were produced by a rare alternative splicingmechanism known as intron retention. The spliced, intronless message was downregulatedpostnatally, while the intron‐retained mRNA species continued to be constitutively expressedthrough adulthood. By contrast in the adrenals, at all stages of development examined, only theintronless message was expressed. In line with previous reports on the failure of glucocorticoidsto induce PNMT expression in the brain, the pattern of PNMT splicing in brainstem explants wasnot affected by the presence of the synthetic glucocorticoid dexamethasone. Undifferentiatedsympathoadrenal PC12 pheochromocytoma cells expressed very low basal levels of both mRNAvariants, accompanied by a very low basal PNMT enzymatic activity. Exposure of PC12 cells todexamethasone resulted in the upregulation of only the spliced mRNA variant concomitant with a3‐fold increase in PNMT enzymatic activity. In contrast, treatment of PC12 cells with nervegrowth factor (NGF) enhanced the expression of both the intron‐retained and the intronlessmRNA species without changes in the basal enzyme activity. This latter result suggests that thetranslation of the intronless mRNA species may be regulated by the intron‐retained mRNAspecies, which by itself may yield a truncated, yet enzymatically functional translational product.Our data suggest that the tissue‐specific regulation of PNMT expression is based on a rarealternative splicing mechanism termed intron retention, and that in the adrenal, but not in thebrain, this mechanism is sensitive to regulation by glucocorticoids. Thus, this system is uniquelysuited for studying the hormonal control of tissue‐specific splicing in the nervous system.
Effects of radiation on a three‐dimensional model of malignant glioma invasion
Authors: Bauman Glenn S. , Fisher Barbara J. , McDonald Warren , Amberger Verena R. , Moore Emi , Del Maestro Rolando F.
Published: July 2002

An experimental model of malignant glioma growth involving implantation of spheroids into a gel matrix of collagen type I has been developed. This model has been used to characterize changes in glioma cell invasion in response to single dose and fractionated radiation treatment. Suspensions of C6 astrocytoma cells were grown in spinner culture flasks to yield spheroids of varying size (300–1000 μm). Implantation of spheroids into a gel matrix of collagen type I was associated with measurable invasion of the surrounding gel by individual tumor cells. Changes in the distance of invasion in response to single dose and fractionated radiation were measured. Changes in apoptosis and proliferative indices in different regions of the spheroids in response to radiation were also assessed. In unirradiated gels, maximum depth of invasion, 1300–1750 μm, was achieved by 5 days after implantation. A radiation dose‐dependent inhibition of invasion was noted and was most profound for larger spheroids. Fractionation of the radiation dose was associated with a partial recovery of invasion. Changes in apoptotic and proliferative indices in response to radiation depended on the region of the spheroid examined. Increases in apoptosis were noted for cells at the surface of the spheroid and invading cells while cells at the centre of the spheroid demonstrated virtually no increase in apoptosis. Likewise, a dose‐dependent decrease in proliferative indices following radiation was noted among the invading cells and cells at the surface of the spheroid but not at the centre of the spheroid.

We have described a model of malignant glioma invasion which possesses many of the qualities of in vivo malignant gliomas. Within this model, invasion appeared to be inhibited by radiation in a dose‐ and fractionation‐dependent fashion. Measurement of apoptotic and cell proliferation indices favour a direct cytotoxic effect on the invading cells as the most likely mechanism for this phenomenon.
The Nordic comparative study on sectorised psychiatry: repeated emergency admissions to inpatient care during a 1-year follow-up
Authors: Saarento O , Christiansen L , Göstas G , Hakko H , Lönnerberg O , Muus S , Sandlund M , Öiesvold T , Hansson L
Published: July 2002

The emergency admissions to hospital care in six psychiatric services in four Nordic countries were explored as a part of a Nordic comparative study on sectorised psychiatry. One year treated incidence cohorts were used, with the total cohort comprising 2,454 patients. Of the 803 patients who were admitted to inpatient care during a 1-year follow-up, 82% had at least one emergency admission and 23% repeated emergency admissions. The definition for the repeated emergency admissions was at least two admissions during the follow-up. The mean length of stay in emergency inpatient care per treatment episode for this patient subgroup was 28 days. Their emergency inpatient episodes constituted 30% of all inpatient days during the follow-up. However, the variations between the services and diagnostic subgroups were large. The results of a logistic regression analysis indicated that the following variables predicted repeated emergency admissions: inpatient care at index contact, emergency outpatient contacts or no planned hospital admissions during the follow-up, psychiatric service, age under 45 years, and a diagnosis of psychosis, personality disorder or dependency. The repeated emergency admissions were related to the existence of a special service unit for abusers but not to the rates of outpatient staff or acute beds in the services, to geographical distances, referral practice or existence of emergency services.
Dividend reinvestment plans as efficient methods of raising equity financing
Authors: Roden Foster , Stripling Tom
Published: July 2002

This paper presents the results of an examination of the effect of establishing dividend reinvestment plans by public utilities. The authors mailed a questionnaire to a sample of public utilities establishing dividend reinvestment plans before May 1981 and use event methodology to determine excess returns surrounding the announcement dates of plans. Empirical analysis reveals statistically significant positive average excess returns during a 15‐day period preceding the announcement. The authors note that the results are consistent with the explanation that DRPs are an efficient alternative to using underwriters to raise equity financing.
THE 1999‐2000 TASK ANALYSIS OF AMERICAN NURSE‐MIDWIFERY/MIDWIFERY PRACTICE
Authors: Oshio Sachiko , Johnson Peter , Fullerton Judith
Published: July 2002

A master list of tasks, which contained 200 task statements, 23 professional issues statements, and 177 clinical conditions, was divided into three equivalent survey forms and distributed to those certified nurse‐midwives (CNMs) and certified midwives (CMs) certified by the ACNM Certification Council, Inc. during the 5‐year period from 1995 to 1999. Specific efforts were made to encourage the participation of CMs, because they represented a new professional cohort. A total of 627 valid responses were obtained. Reasonably similar numbers of respondents contributed data related to each of the three versions of the survey form. The responsibilities have expanded substantially within the domains of nonreproductive primary health care and gynecologic care of the well woman, including advances in assisted reproductive technology. A diminished emphasis on the CNM/CM role in the provision of newborn care was documented. The ACC Research Committee recommended the revision of the entry‐level certification examination blueprint, and this was approved by the ACC Board of Directors. The specific recommendations included the development of a new primary care domain and the reconfiguration of content emphasis with percentage allocations as follows: Primary Care, 5‐10%; Well‐Woman/Gynecology, 15‐20%; Newborn, 5‐10%; Postpartum, 5‐10%; Antepartum, 25‐30%; Intrapartum, 25‐35%; Professional Issues, up to 5%.
Defluorinative Diborasodiation of Benzotrifluorides with Bis(pinacolato)Diboron and Sodium
Authors: Ito Shiori , Takahashi Fumiya , Yorimitsu Hideki
Published: April 2021

Treatment of benzotrifluorides with sodium dispersion in the presence of bis(pinacolato)diboron results in diborative reduction to yield the corresponding diborylbenzylsodium species. The anionic species react not only with reactive organic halides but also with aromatic carbonyl compounds to yield the corresponding alkenylboron compounds via Peterson‐type olefination. The success of the generation of the diborylbenzylsodium species lies in immediate capture of initially formed unstable difluorobenzylsodium with co‐existing reduction‐resistant bis(pinacolato)diboron.
Atom‐Mediated Phonon Blockade and Controlled‐Z Gate in Superconducting Circuit System
Authors: Zhao Chengsong , Peng Rui , Yang Zhen , Chao Shilei , Li Chong , Zhou Ling
Published: April 2021

A scheme to generate phonon blockade in a superconducting Josephson junction circuit system is proposed, where the photon, phonon, and artificial two‐level atom are bound into a tripartite interaction. The phonon blockade in the proposal mediated by the two‐level atom differs from the phonon blockade resulting from the single phonon resonance and the destructive interference between different paths, which can be generated within a weak coupling region and a large range of cavity detuning, even with a large optical dissipation rate. In addition, under certain condition, the unconventional photon blockade can be achieved but the phonon blockade is still maintained. Based on the phonon blockade, it is shown that the controlled‐Z gate (CZ) can be implemented with the tripartite interaction.