bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of anti‐secretory medication: a population‐based cohort study
Authors: Lassen A. , Hallas J. , Schaffalitzky de Muckadell O. B. 
Published: August 2004

SummaryBackground : Total use of anti‐secretory medication (H2 blockers and proton pump inhibitors) is increasing rapidly, but knowledge of factors related to the increasing use is sparse.Aim : To describe development in the use of anti‐secretory medication between 1993 and 2002 at a population level.Methods : We extracted data on use of anti‐secretory medication (H2‐blockers and proton pump inhibitors) and ulcerogenic drugs, demographic data, and data on gastroscopy and endoscopically verified oesophagitis and peptic ulcer diagnoses, from three large population‐based databases covering the County of Funen, Denmark 1990–2002 (population 470 000).Results : Between 1993 and 2002 incidence of first time users was stable at 16.7/1000 persons/year. Total amount of consumed anti‐secretory medication increased from 10.5 DDD/1000 persons/day to 25.2 DDD/1000 persons/day. Ninety per cent of the increase was related to long‐term use of anti‐secretory medication (≥180 DDD/patient/year). In 1993 21% of the anti‐secretory medication was used by patients with oesophagitis, this increased to 28% in 2002. The proportion of medication used by peptic ulcer patients decreased from 29% in 1993 to 19% in 2002.Conclusions : Total use of anti‐secretory medication increased as a result of more extensive long‐term use, and most of the medication was used by patients without diagnosed peptic ulcer or oesophagitis.
Basic fibroblast growth factor as a response parameter to infliximab in fistulizing Crohn's disease
Authors: Gao Q. , van Hogezand R. A. , Lamers C. B. H. W. , Verspaget H. W. 
Published: August 2004

SummaryBackground : Fibroblast growth factors play an important role in (patho)physiological processes such as wound healing and tissue repair. We previously showed that basic fibroblast growth factor is actively involved in inflammatory bowel disease processes. In the present retrospective study, we assessed whether serum basic fibroblast growth factor levels in Crohn's disease patients reflect the response to anti‐tumour necrosis factor‐α antibody infliximab treatment.Aim and methods : Serum samples, biopsies and patient data from a subgroup of patients included in two placebo‐controlled trials were used. Fistulizing Crohn's disease patients (n = 42) were administered placebo or infliximab intravenously three times and evaluated for response up to 18 weeks. Biopsies from a subgroup of patients were stained for basic fibroblast growth factor using indirect immunohistochemistry. In the active Crohn's disease trial, patients (n = 24) received either placebo or infliximab once, and disease activity and serum basic fibroblast growth factor were assessed at weeks 0 and 4.Results : Basic fibroblast growth factor levels at inclusion were comparable in the fistulizing Crohn's disease patients regardless of whether the fistulas did or did not respond or completely heal (median range: 9.3–10.6 pg/mL). At the end of follow‐up basic fibroblast growth factor levels were lower in patients who responded (9.2 pg/mL, P = 0.06) or who were completely healed (8.9 pg/mL, P = 0.009) when compared with patients did not respond/heal (14.5 pg/mL), the latter not significantly increased from baseline. Decreases in the perianal disease activity index and open fistula scores at the end of the follow‐up were significantly correlated with the decrease in basic fibroblast growth factor (R = 0.41; P = 0.012 and R = 0.35; P =0.027, respectively). Immunohistological evaluation also showed a trend towards decreased basic fibroblast growth factor expression in intestinal biopsies of these patients. Patients with active disease, i.e. a Crohn's disease activity index ≥220 combined from the two studies, were found to have significantly (P = 0.0046) lower baseline serum basic fibroblast growth factors levels than those with inactive disease (5.3 vs. 10.3pg/mL, respectively). Treatment of the active disease patients did not affect the serum basic fibroblast growth factor level, although a general decrease in disease activity was observed with infliximab treatment.Conclusions : Healing of fistulizing/perianal Crohn's disease seems to be reflected by a decrease in high serum basic fibroblast growth factor. Basic fibroblast growth factor levels do not relate with response in active Crohn's disease patients.
Insulin and Phorbol Ester Stimulate Initiation Factor eIF–4E Phosphorylation by Distinct Pathways in Chinese Hamster Ovary Cells Overexpressing the Insulin Receptor
Authors: Flynn Andrea , Proud Christopher G. 
Published: August 2004

We have developed a one‐dimensional isoelectric focusing technique to measure changes in the steady‐state phosphorylation of the cap‐binding initiation factor, eIF‐4E. We have used a Chinese hamster ovary cell line transfected with the human insulin receptor (CHO.T cells) to study the regulation of eIF‐4E phosphorylation by insulin and other stimuli. Exposure of CHO.T cells to insulin, phorbol ester or serum resulted in a rapid increase (up to twofold) in eIF‐4E phosphorylation. As a control, we have also performed experiments with the parental cell line, CHO.K1 cells, in which both serum and phorbol ester, but not nanomolar concentrations of insulin, produce similar changes in eIF‐4E phosphorylation.We have used two complementary approaches to study the role of protein kinase C (PKC) in these responses: a highly specific inhibitor of PKC and down‐regulation of PKC by prior treatment of the cells with phorbol ester. In CHO.T cells, both approaches indicate that PKC is required for the response to phorbol ester but that insulin and serum each increase elF‐4E phosphorylation by a mechanism(s) independent of this protein kinase. Similarly, PKC is necessary for the effects of phorbol ester, but not of serum, on eIF‐4E phosphorylation in CHO.K1 cells. These data indicate that multiple signal transduction mechanisms are involved in the modulation of eIF‐4E phosphorylation and the implications of these findings are discussed.
Synthesis of Stereoisomers and Isoforms of a Tryptic Heptapeptide Fragment of Human Growth Hormone and Analysis by Reverse‐Phase HPLC and Capillary Electrophoresis
Authors: Vinther Anders , Holm Arne , Høeg‐Jensen Thomas , Jespersen Anne M. , Klausen Niels K. , Christensen Thorkild , Sørensen Hans H. 
Published: August 2004

The amino acid sequence Asn‐Gly has at pH 7 a tendency to induce deamidation of asparagine to aspartic acid via the formation of a cyclic imide. This imide opens up to yield Asp‐Gly or the isoaspartic acid (isoAsp) form, isoAsp‐Gly. Both isomers may be found in their l‐form or d‐form. Like Asn‐Gly, the sequence Asp‐Gly has a tendency for isomerization and racemization via the formation of a cyclic imide intermediate.When human growth hormone is digested with trypsin, one of the fragments is a heptapeptide (amino acid residues 128–134) containing the amino acid sequence Asp‐Gly (amino acid residues 130 and 131). This heptapeptide, as well as stereoisomers and isoforms where l‐Asp was replaced by d‐Asp, l‐isoAsp, d‐isoAsp or the l‐cyclic imide, respectively, has been synthesized and used as a standard to achieve separation of the five forms by capillary electrophoresis and by reverse‐phase HPLC.Capillary electrophoresis analysis was performed in uncoated capillaries by the use of aspartic acid/cyclodextrin buffers at low pH. The elution order of the aspartic‐acid‐containing heptapeptides was d‐Asp, asp, l‐isoAsp, d‐isoAsp and l‐cyclic imide. Reverse‐phase HPLC analysis was performed on a C18 column by the use of a shallow acetonitrile gradient in trifluoroacetic acid/water. The elution order was d‐isoasp, l‐isoAsp, l‐asp, d‐Asp and l‐cyclic imide.Human growth hormone samples were degraded by incubation at high temperature and analyzed for their potential content of isomerization and racemization products. Only l‐forms of aspartic acid and isoaspartic acid of the heptapeptide fragment were found.
ATP Synthesis by the F0F1 ATP Synthase from Thermophilic Bacillus PS3 Reconstituted into Liposomes with Bacteriorhodopsin
Authors: Pitard Bruno , Richard Peter , Duñarach Mireia , Girault Guy , Rigaiud Jean‐Louis 
Published: August 2004

Optimal conditions for the reconstitution of bacteriorhodopsin and H+‐transporting ATP synthase from thermophilic Bacillus PS3 (TF0F1) were determined. Phosphatidylcholine/phosphatidic acid liposomes prepared by reverse‐phase evaporation were treated with various amounts of Triton X‐100, octyl glucoside, octaethylcne glycol n‐dodecylether, sodium cholate or sodium deoxycholate and the incorporation of proteins by these detergents was studied at each step of the solubilization process. After removal of detergent by means of SM‐2 Bio‐Beads, the light‐driven ATP synthase activities of the resulting proteoliposomes were analyzed at 40°C. The nature of the detergent used for reconstitution wits important for determining the mechanism of protein insertions. The most efficient reconstitutions were obtained with octyl glucoside or Triton X‐100 by insertion of the proteins into detergent‐saturated liposomes.The conditions for reconstitution were further optimized with regard to functional coupling between bacteriorhodopsin and TF0F1. It was demonstrated that one of the main factors limiting the production of efficient reconstituted proteoliposomes was related to activation of the highly stable TF0F1. Activation was accomplished by total solubilization of phospholipids and proteins in a Triton X‐100/octyl glucoside mixture containing 20 mM octyl glucoside, leading to a threefold slii1iulation of the ATP synthase activities. Final ATP synthase activities depended greatly on the lipid/bacteriorhodopsin and the lipid/TF0F1 ratios as well as on the phospholipid used. In particular, light‐driven ATP synthesis depended upon the presence of negatively charged phospholipids. Cholesterol was found to induce a fourfold increase in ATP synthase activity with a concomitant 65 % decrease in the Km for ADP, suggesting that sterols can modulate catalytic events mediated by F1.Preparations obtained by this step‐by‐step reconstitution procedure displayed activities up to 20‐fold higher (500–800 nmol ATP. min‐1 mg TF0F1−1 in the presence of cholesterol) than the maximal values reported in the literature for light‐driven ATP synthesis by TF0F1 measured under similar conditions. This study also allowed rationalization of the different parameters involved in reconstitution experiments and the present simple method is shown to be of general use for preparation of efficient proteoliposomes containing bacteriorhodopsin and choloroplast or mitochondrial F0F1‐type ATP synthases.
CMP–3‐Deoxy‐d‐Glycerol‐d‐Galacto‐Nonulosonic Acid (CMP‐Kdn) Synthetase
Authors: Terada Takaho , Kitajima Ken , Inoue Sadako , Koppert Klaus , Brossmer Reinhard , Inoue Yasuo 
Published: August 2004

In this report we present kinetic data of the activation reaction of several synthetic 3‐deoxy‐d‐glycero‐d‐galacto‐nonulosonic acid (Kdn) and N‐acetylneuraminic acid (Neu5Ac) analogues catalyzed by the rainbow trout testis CMP‐Kdn synthetase. This enzyme showed broad substrate specificity in terms of substitutions at C4 or C5 position of Kdn and Neu5Ac. In contrast, calf brain CMP‐N‐acylneuraminic acid synthetase had narrow substrate specificity, being active only on various N‐acyl analogues of Neu5Ac and only slightly active on Kdn derivatives.Usefulness of the trout testis enzyme for synthesis of various CMP‐sialate analogues, which could be donor substrates for sialyltransferases, was demonstrated.
Structure of the O‐Specific Polysaccharide of an Aeromonas Trota Strain Cross‐Reactive with Vibrio Cholerae O139 Bengal
Authors: Knirel Yuriy A. , Senchenkova Sof'ya N. , Jansson Per‐Erik , Weintraub Andrej , Ansaruzzaman Mohammed , Albert M. John 
Published: August 2004

The O‐specific polysaccharide of an Aeromonas trota strain was isolated by hydrolysis of the lipopoly‐saccharide at pH 4.5 followed by gel‐permeation chromatography and found to consist of hexasaccharide repeating units containing D‐galactose, L‐rhamnose, 3,6‐dideoxy‐L‐xylo ‐hexose (colitose, Col), 2‐acet‐amido‐2‐deoxy‐D‐glucose and 2‐acetamido‐2‐deoxy‐D‐galactose in the ratios 1:1:2:1:1. Partial hydrolysis of the polysaccharide with 48% hydrofluoric acid resulted in selective removal of colitose to give a modified polysaccharide containing the other four sugar constituents. On the basis of methylation analysis and NMR spectroscopic studies of the initial and modified, colitose‐free polysaccharide, it was concluded that the repeating unit of the O‐specific polysaccharide has the following structure
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The known cross‐reactivity between the strain studied and Vibrio cholerae 0139 Bengal is substantiated by the presence of a common colitose‐containing epitope shared by the O‐specific polysaccharide of A. trota and the capsular polysaccharide of V. cholerae, which is thought to carry determinants of O‐specificity.
Association of the Cytoplasmic Domain of Intercellular‐Adhesion Molecule‐1 with Glyceraldehyde‐3‐Phosphate Dehydrogenase and β‐Tubulin
Authors: Federici Christian , Camoin Luc , Hattab Maurice , Strosberg Arthur Donny , Couraud Pierre‐Olivier 
Published: August 2004

To elucidate the molecular mechanisms of the transendothelial migration of leukocytes, we attempted to identify the cellular proteins capable of interaction with the cytoplasmic domain of the intercellular adhesion molecule‐1 (ICAM‐1) in a rat brain microvessel endothelial cell line (RBE4 cells). A 27‐amino‐acid synthetic peptide, corresponding to the cytoplasmic domain of rat ICAM‐1, was covalently linked to a Sepharose matrix. Upon affinity chromatography of RBE4 cell cytosol, several ICAM‐1‐interacting proteins were specifically eluted by the soluble peptide. Two of these proteins have been identified by microsequencing as the cytoskeletal protein β‐tubulin and the glycolytic enzyme glyceraldehyde‐3‐phos‐phate dehydrogenase (GraP‐DH). Experiments carried out with purified GraP‐DH or CNBr fragments of GraP‐DH indicated that binding to the ICAM‐1 matrix was mediated by the C‐terminal domain of GraP‐DH, containing the binding site of the cofactor NATL+, and that NATL+ could compete with this binding. Using a series of ICAM‐1 C‐terminal truncated peptides, we could demonstrate that (a) the nitric‐oxide‐induced covalent linkage of NATL+ to GraP‐DH was impaired by these peptides, (b) the glycolytic activity of GraP‐DH was drastically inhibited by a truncated peptide containing the 15 C‐terminal residues, (c) nitric oxide appeared to prevent this inhibition.Together, our results demonstrate that GraP ‐DH specifically associates with the isolated ICAM‐1 cytoplasmic domain. Since GraP ‐DH is known as a microtubule bundling protein, these findings suggest that, in a cellular environment, GraP‐DH may behave as an Actaptor molecule by linking ICAM‐1 to the microtubule network. The role of nitric oxide in the modulation of this interaction deserves further investigation.
Secondary Structural Elements as a Basis for Antibody Recognition in the Immunodominant Region of Human Immunodeficiency Viruses 1 and 2
Authors: Markert Robert L. M. , Ruppach Horst , Gehring Stephan , Dietrich Ursula , Mierke Dale F. , Köck Matthias , Rübsamen‐waigmann Helga , Griesinger Christian 
Published: August 2004

Synthetic peptide antigens corresponding to the entire third variable region V3, the principal neutralizing determinant of the human immunodeficiency virus (HIV) envelope glycoprotein of HIV‐1 subtype B (1), HIV‐2 subtype A (5), and HIV‐2 subtype B (7) were synthesized by solid‐phase peptide synthesis (Table 1).1and5were also prepared as their GlcNAc‐glycosylated forms at the natural N‐glycosylation site NXT (positions 6–8; peptides4and6). Additionally, the proposed β‐turn region of 1 (GPGR; positions 15–18) was altered by introducing D‐Ala17 (2) and D‐Pro16 (3). All compounds have been studied by two‐dimensional NMR techniques. Interproton distances and3JNH/Hαcoupling constants derived from NMR data are used as restraints in distance geometry and ENSEMBLE‐Distance and angle‐bound driven dynamics calculations. The simulations led to disordered conformations except for a high propensity of a βII‐turn in the region GPXR (positions 15–18) in1,2, and4. In3(G‐D‐ProGR, positions 15–18), a type βII‐turn was mainly found instead. For peptide7, the consensus sequence of HIV‐2 subtype B, a type βrturn was also found although the primary structure (VSGL; positions 15–18) differs grossly from the HIV‐1 peptide1. With the exception of2, all βIIturns were able to form a canonically opened β‐turn by a 180° rotation of φ(G17). Surprisingly, compounds5and6that are highly similar to7showed no βIItype turn within MSGL (positions 15–18). They form a type βVIII‐turn across the tetrapeptide SGLV (positions 16–19) together with a non‐canonical turn conformation across LMSG (positions 14–17) leading to an S‐conformation.The reaction of the peptides with HIV‐positive sera from patients infected with different subtypes of HIV‐1 and HIV‐2 was tested in enzyme‐linked immunosorbent assays (ELISA reactions). No HIV‐2 sera reacted with peptide1and no HIV‐1 sera showed reactivity to peptide5. We propose that certain amino acid exchanges within the V3 domain lead to altered conformations of the V3 loop resulting in antibodies that show altered binding properties to the peptide antigens used in the ELISA reactions.
Heterologous Expression and Site‐Directed Mutagenesis Studies on the Activation Mechanism and the Roles of the Basic Residues in the Prosegment of Aspergillopepsinogen I
Authors: Inoue Hideshi , Hayashi Takaharu , Huang Xiang‐Ping , Lu Jing‐Fang , Athauda Senarath B. P. , Kong Kwang‐Hoon , Yamagata Hideo , Udaka Shigezo , Takahashi Kenji 
Published: August 2004

To study the structure/function relationship of the prosegment of aspartic proteinase, a putative pro‐form of aspergillopepsin I (or proteinase B) from Aspergillus niger var. macrosporus was expressed by Escherichia coli, refolded in vitro, and purified. The conversion of the purified proenzyme (aspergillopepsinogen I, proproteinase B) into the active mature form occurred at pH≤4.5 and was completely inhibited by pepstatin A, a specific inhibitor for aspartic proteinase, suggesting autoprocessing. The N‐terminus of this mature form was Glu67 (numbering in preproform), which was different from the N‐terminal Ser70 of native proteinase B although there was no significant difference in enzymatic activity. During the conversion, two intermediates were observed on SDS/PAGE, indicating a stepwise mechanism. The Lys56‐Phe57 sequence seems to be a counterpart of the Lys‐Tyr pair highly conserved in the prosequences of aspartic proteinases. When the mutant proenzyme (K56N), in which Lys56 was replaced with Asn by site‐directed mutagenesis, was allowed to refold under various conditions, no significant potential activity could be obtained.Proproteinase B was also expressed by Bacillus brevis HPD31. This system required no in vitro refolding to obtain potentially active proenzyme, which was secreted into the culture medium (30–120mg/l) and had the same properties with that obtained by the E. coli system. The K56N mutant prepared by this system also had no potential activity, and was rapidly digested by incubation with native proteinase B, suggesting that the mutant did not fold correctly. On the other hand, the K56R mutant (Lys56→Arg) was potentially active. These results indicated that Lys56 is essential for the folding through electrostatic interaction with the catalytic Asp residues in the active site although it may be replaced with Arg. In the presence of a low concentration of pepstatin A, an incompletely processed form with N‐terminal Ser53 was obtained. Further, the R52Q (Arg52→Gln) mutant showed no processing but was converted to the active mature form by incubation with the native enzyme. Therefore, the cleavage between Arg52 and Ser53 is considered to be the initial and essential step of the autoactivation. The R26Q, K27Q, R36Q, K40Q, R42Q, and K66Q mutants were also potentially active. The K66Q mutant was processed to a form with N‐terminal Ala55.
Regulation of Prothymosin α During the Cell Cycle
Authors: Vareli Katerina , Tsolas Orestes , Frangou‐Lazaridis Maria 
Published: August 2004

A number of studies have indicated that the small nuclear acidic protein prothymosin α is associated with cellular‐proliferation events. For example, c‐myc causes immediate transcriptional activation of prothymosin α, and prothymosin α antisense oligonucleotides inhibit myeloma cell division.To investigate the regulation of prothymosin α, we examined its mRNA and protein levels during the cell cycle of mononuclear cells and fibroblastic cells. We isolated immunoreactive material from cellular extracts and immunolocalized the protein to the nucleus during the cell cycle. We report here that the material present in the cells is prothymosin α rather than the amino‐terminal peptide thymosin α1. [3H]Thymidine‐incorporation studies associate maximum accumulation of mRNA and protein with the S/G2 phase of the cell cycle. This induction of prothymosin α mRNA seems to resemble cyclin B expression and is more pronounced in fibroblasts. Moreover, transient‐transfection experiments indicate that transcription factor E2F is a strong positive regulator of the prothymosin α gene. Our results are consistent with the hypothesis that prothymosin α is involved in proliferation checkpoints of the cell cycle.