bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitrite Reductase from the Magnetotactic Bacterium Magnetospirillum magnetotacticum
Authors: Yamazaki Takehiro , Oyanagi Hiroyuki , Fujiwara Taketorao , Fukumori Yoshihiro
Published: September 2004

Cytochrome cd1, nitrite reductase was isolated from magnetite‐containing cells of the magnetotactic bacterium Magnetospirillum (formerly Aquaspirillum) magnetotacticum, which was microaerobically cultivated under denitrifying conditions. The enzyme showed absorption maxima at 643 nm and 409 nm in the oxidized form, and at 663, 551, 522, and 418 nm in the reduced form. A distinctive split absorption band did not occur at about 550 nm. The pyridine ferrohemochrome spectra suggested the presence of heme c and heme d1 in the molecule. The enzyme was composed of two identical subunits each with a molecular mass of 54 kDa; each subunit contained one c ‐type and one d ‐type heme. The isoelectric point was 9.2. The redox potentials of heme c and heme d1, were estimated to be +191 mV and +180mV, respectively. Although the enzyme showed cyanide‐sensitive N,N,N′,N′ ‐tetramethyl‐p–phenylenediamine‐O2 oxidoreductase activity and N,N,N′,N′ ‐tetramethyl‐p ‐phenylenediamine‐nitrite oxidoreductase activity, the enzyme did not oxidize M. magnetotacticum ferrocytochrome c ‐550 and Pseudomonas aemginosa ferrocytochrome c ‐551 in the presence of nitrite. Furthermore, sodium succinate did not cause the reduction of cytochrome cd1 in the crude cell‐free extract prepared from the magnetite‐containing bacterial cells. However, M. magnetotacticum cytochrome cd1 showed a novel Fe(II): nitrite oxidoreductase activity whereas P. aeruginosa cytochromes cd1 had no Fe(II): nitrite oxidoreductase activity. These results suggest that M. magnetotacticum cytochrome cd1 may function as a Fe(II)‐oxidizing enzyme under microaerobic conditions using nitrite as electron acceptor.
The Uniform Galactose 4‐Sulfate Structure in the Carbohydrate‐Protein Linkage Region of Human Urinary Trypsin Inhibitor
Authors: Yamada Shuhei , Oyama Mika , Yuki Yoshikazu , Kato Kazuo , Sugahara Kazuyuki
Published: September 2004

The carbohydrate‐protein linkage region of a chondroitin 4‐sulfate chain attached to urinary trypsin inhibitor (UTI) was isolated from human urine and characterized structurally. The chondroitin 4–sulfate chain was released from UTI by β‐elimination using alkaline NaBH4 then digested with chondroitinase ABC. These treatments resulted in only a single hexasaccharide alditol derived from the carbohydrate‐protein linkage region. Chemical and enzymic analyses and 600–MHz 1H‐NMR spectroscopy revealed that the hexasaccharide alditol had the following structure: ΔHexAα1‐3GalNAc(4‐sulfate)β1‐4GlcAβ1‐3Gal(4‐sulfate)β1‐3Galβ1‐4Xyl‐ol, where ΔHexA, GlcA and Xyl‐ol represent 4‐deoxy‐α‐L‐threo ‐hex‐4–enepyranosyluronic acid, D‐glucuronic acid and D‐xylitol, respectively. This structure contained the novel 4‐sulfated Gal residue, which was first demonstrated in one of the three linkage hexasaccharide‐serines isolated from chondroitin 4‐sulfate of rat chondrosarcoma [Sugahara, K., Yamashina, I., de Waard, P., Van Halbeek, H. & Vliegenthart, J. F. G. (1988) J. Biol Chem. 263, 10168–10174]. This disulfated structure was recently identified as the sole structural component in the linkage hexasaccharide alditol fraction isolated from inter‐α‐trypsin inhibitor (ITI) in human plasma [Yamada, S., Oyama, M., Kinugasa, H., Nakagawa, T., Kawasaki, T., Nagasawa, S., Khoo, K.‐H., Morris, H. R., Dell, A. & Sugahara, K. (1995) Glycobiology 5, 335–341]. The structural uniformity in the linkage hexasaccharide structure of ITI and UTI is in marked contrast to the heterogeneity demonstrated in the linkage hexasaccharides isolated from cartilaginous chondroitin sulfate whose linkage regions are sometimes but not always phosphorylated on the Xyl residue or sulfated on the Gal residue(s). The uniform structure containing the novel 4‐sulfated Gal residue in the linkage region of UTI and ITI may imply its significance in the biosynthetic mechanism of chondroitin sulfate.
Metchnikowin, a Novel Immune‐Inducible Proline‐Rich Peptide from Drosophila with Antibacterial and Antifungal Properties
Authors: Levashina Elena A. , Ohresser Serge , Bulet Philippe , Reichhart Jean‐Marc , Hetru Charles , Hoffmann Jules A.
Published: September 2004

One of the characteristics of the host defense of higher insects is the rapid and transient synthesis of a variety of potent antimicrobial peptides. To date, several distinct inducible antimicrobial peptides or peptide families have been totally or partially characterized. We present here the isolation and characterization of a novel 26‐residue proline‐rich immune‐inducible peptide from Drosophila, which exhibits both antibacterial (Gram‐positive) and antifungal activities. Peptide sequencing and cDNA cloning indicate the presense of two isoforms in our Drosophila OregonR strain, which differ by one residue (His compared to Arg) as a consequence of a single nucleotide change. The gene, which maps in position 52A1‐2 on the right arm of the second chromosome, is expressed in the fat body after immune challenge. The novel peptide, which we propose to name metchnikowin, is a member of a family of proline‐rich peptides, and we discuss the possible evolutionary relationships within this family.
Afaâcytin, an αβ‐fibrinogenase from Cerastes cerastes (Horned Viper) Venom, Activates Purified Factor X and Induces Serotonin Release from Human Blood Platelets
Authors: Laraba‐Djebari Fatirna , Martin‐Eauclaire Marie‐France , Mauco Gérard , Marchot Pascale
Published: September 2004

Afaâcytin, a proteinase with caseinolytic, arginine‐esterase and amidase activities, was purified from the venom of Cerastes cerastes (horned viper) in two steps by gel filtration through Sephadex G75, then HPLC on carboxymethyl‐cellulose. Afaâcytin has an isoelectric point of 6.25. and consists of two sub‐units, α and β, which have the same apparent molecular mass (40000) and are indistinguishable in the absence of reduction or/and deglycosylation. Subunit β is constituted of two disulfide‐linked polypeptidic chains, β and β′. The respective apparent molecular mass of the chains are 43000 (α), 35500 (β) and 10200 (β') as determined by SDS/PAGE under reducing conditions. Both chains α and β are N‐glycosylated. The two chains have the same N‐terminal sequence (20 residues) which is similar to those of other proteinases from snake venom. Susceptibility of afaâcytin to diisopropyl fluorophosphate and benzamidine indicates the presence of a serine and an aspartic (or glutamic) acid residues in the catalytic site. Ca2+ appears to be required for structural cohesion of the afaâcytin molecule. Afaâcytin exhibits αβ‐fibrinogenase and α‐fibrinase properties. It replaces missing factors VIII and IX in deficient plasmas, and activates purified human factor X into factor Xa. It releases serotonin from platelets and directly aggregates human (but not rabbit) blood platelets. Despite its thrombin‐like characteristics, however, afaâcytin is not inhibited by plasmatic thrombin inhibitors. The procoagulant properties of afaâcytin therefore have potential clinical applications.
The Functional Integration of a Polytopic Membrane Protein of Escherichia coli is Dependent on the Bacterial Signal‐Recognition Particle
Authors: Macfarlane Juan , Müller Matthias
Published: September 2004

In eukaryotes, the cotranslational targeting of proteins to the endoplasmic reticular membrane is initially mediated by the signal‐recognition particle (SRP), a ribonucleoprotein complex consisting of the 7SL RNA and six protein subunits. Since the discovery of sequence homology between (a) the Escherichia coli 4.5s RNA (Ffs) and 7SL RNA, and (b) the E. coli P48 (Ffh) and SRP 54‐kDa subunit, more evidence has been obtained that E. coli also possesses an SRP‐type pathway that acts in the translocation of secreted proteins. Such a pathway could possibly be involved in the cotranslational integration of hydrophobic membrane proteins that cannot be effectively targeted post‐translationally due to folding and aggregation. In this study, we report that disruption of the E. coli SRP complex with a dominant lethal 4.5s RNA mutant in vivo prevents functional membrane integration of the E. coli lactose permease (Lacue). Likewise, depletion of the P48 (Ffh) protein also results in a decrease in the amount of functional Laue inserted into the E. coli plasma membrane. In direct contrast, inhibition of SecA function does not affect Laue integration. These results suggest a major function of the bacterial SRP in the targeting and subsequent integration of hydrophobic membrane proteins as opposed to SecA mediating the post‐translational targeting of secretory proteins.
A Novel Membrane Glycoprotein Involved in Ascidian Hemocyte Aggregation and Phagocytosis
Authors: Takahashi Hiroki , Azumi Kaoru , Yokosawa Hideyoshi
Published: September 2004

Invertebrate hemocytes undergo several cellular defense reactions. To clarify the molecular mechanisms for cellular recognition between hemocytes and also between hemocytes and foreign materials, we established hybridoma clones producing monoclonal antibodies that inhibit hemocyte aggregation (i.e. a cellular reaction between hemocytes) in the solitary ascidian, Hulocynthia roretzi. The antibody, A74, also inhibited phagocytosis of foreign materials by H. roretzi hemocytes.

Immunocytochemistry of H. roretzi hemocytes using A74 antibody revealed the localization of the A74 antigen on the surface of hemocytes. The A74 antigen, which is referred to as A74 protein, was purified from a hemocyte membrane preparation by three chromatographies on phenyl‐Sepharose, A74 antibody‐immobilized Sepharose and Mono Q. The A74 protein was a glycoprotein with a molecular mass of 160 kDa; N‐glycosidase or neuraminidase treatment resulted in a reduction of its molecular mass. The N‐terminal amino acid sequence of A74 protein showed little similarity to other known proteins. Thus, the A74 protein is a novel membrane protein that plays an important role in ascidian cellular defense reactions.
Characterization of the Lower‐Molecular‐Mass Fraction of Venoms from Dendroaspis Jamesoni Kaimosae and Micrurus Fulvius Using Capillary‐Electrophoresis Electrospray Mass Spectrometry
Authors: Perkins John R. , Tomer Kenneth B.
Published: September 2004

Capillary electrophoresis (CE) with electrospray ionization (ESI) and selected ion‐monitoring mass‐spectrometric (SIM‐MS) detection has been used to provide as much information as possible about the lower molecular‐mass fraction (peptides of molecular masses up to 8500 Da) of the venoms of Dendroaspis jamesoni kaimosae (Jameson's Mamba) and Micrurus fulvius (Eastern Coral Snake). Method development was based on the venom of D. jarnesoni kaimosae, which contains some previously described peptides, with subsequent application to the completely unknown venom of M. fulvius. CE‐ESI‐SIM‐MS provides a rapid and extremely sensitive method for the detection and molecular‐mass determination of peptides present in venoms. It has been utilized to provide molecular masses and thus, by inference, confirmation of the peptide compositions for those toxins which have been previously described in the literature. Our methodology indicates the presence of 83 peptides in the venom of D. jarnesoni kaimosae and 49 peptides in the venom of M. fulvius in the molecular‐mass range 6000–8500 Da.
NMR‐Based Structural Studies of the pNR‐2/pS2 Single Domain Trefoil Peptide
Authors: Polshakov Vladimir I. , Frenkiel Thomas A. , Westley Bruce , Chadwick Mark , May Felicity , Carr Mark D. , Feeney James
Published: September 2004

NMR spectroscopy measurements have been used to obtain structural information about the pNR‐2/pS2 single‐domain trefoil peptide. NMR data from 2D (two dimensional) double‐quantum‐filtered correlation spectroscopy (DQF‐COSY), total correlation spectroscopy (TOCSY), NOE spectroscopy (NOESY), rotating frame NOE spectroscopy (ROESY) and 2D 13C‐1H heteronuclear single‐quantum coherence (HSQC) and 13C‐1H HSQC‐TOCSY spectra have been analysed to provide essentially complete 1H and 13C sequence‐specific assignments for the pNR‐2/pS2 protein. From a consideration of the NOE intensities, 3J(NH‐αCH) coupling constants, 1H and 13C chemical shifts of backbone atoms and amide‐proton exchange rates, the pNR‐2/pS2 was found to contain two short antiparallel β‐strands (32–35 and 43–46), a short helix (25–30) and a type I β‐turn (11–15). These elements of secondary structure are very similar to those found in the two trefoil domains of pSP for which detailed structural information is already available. Similar 1H chemical shifts were noted for several conserved residues in pNR‐2/pS2 and pSP and a characteristic Phe residue with a slowly flipping ring was found in the pNR‐2/pS2 variant and in both domains of pSP. The tertiary structures of the domains therefore appear to be very similar in the two proteins and it is likely that the pNR‐2/pS2 has the same pattern of disulphide bonds (1–5, 2–4, 3–6) as pSP. Correlation time measurements derived from 1H‐1H NOE measurements indicate that the Cys58→Ser form of the pNR‐2/pS2 protein used in this study is monomeric in solution at approximately 2mM.
Molecular Properties of the Dissimilatory Sulfite Reductase from Desulfovibrio Desulfuricans (Essex) and Comparison with the Enzyme from Desulfovibrio Vulgaris (Hildenborough)
Authors: Steuber Julia , Arendsen Alexander F. , Hagen Wilfred R. , Kroneck Peter M. H.
Published: September 2004

The dissimilatory sulfite reductase desulfoviridin was purified from the membrane (mSiR) and the soluble fraction (sSiR) of the sulfate‐reducing bacterium Desulfovibrio desulfuricans (Essex). Molecular and spectroscopic properties were determined and compared with the properties of the soluble desulfoviridin from Desulfovibrio vulgaris (Hildenborough). The enzymes were isolated as α2β2γn (n=1–3) multimers with a relative molecular mass of 200±10 (gel filtration). Both mSiR and sSiR from D. desulfuricans contained 24±3 Fe and 18±3 labile sulfide/200 kDa, respectively, and showed identical EPR spectra. Quantification of the high‐spin Fe(III) heme resonances at g of approximately 6 indicated that close to 80% of the siroheme moiety in the enzyme from D. desulfuricans was demetallated. D. desulfuricans sulfite reductase showed S=9/2 EPR signals with the highest apparent g value at g=17 as reported for SiR from D. vulgaris. Antibodies raised against the α, β and γ subunit of the D. vulgaris enzyme exhibited cross‐reactivity with the subunits of mSiR and sSiR from D. desulfuricans. N‐terminal sequences of α, β and γ subunits of both mSiR and sSiR from D. desulfuricans were identical and showed a high degree of similarity with the sequences of the corresponding subunits obtained from the D. vulgaris enzyme. During gel filtration of sSiR from D. desulfuricans, under non‐denaturing conditions, a small protein (molecular mass ≈ 11 kDa) was separated. This 11‐kDa protein exhibited cross‐reactivity with the antibody raised against the γ subunit of D. vulgaris sulfite reductase. In the case of D. desulfuricans sulfite reductase, the 11‐kDa γ subunit seems not to be an integral part of the protein and can be obtained from the soluble fraction and during purification of the soluble enzyme.
Triggering of a Phospholipase D Pathway Upon Mitogenic Stimulation of Human Peripheral Blood Mononuclear Cells Enriched with 12(S)‐hydroxyicosatetraenoic Acid
Authors: Meskini Nadia , Zakaroff Alexia , Joulain Catherine , Némoz Georges , Lagarde Michel , Prigent Annie‐France
Published: September 2004

The influence of 12(S)‐hydroxyicosatetraenoic acid (12‐HETE), that we have previously shown to decrease the proliferative response of human lymphocytes to mitogens, on diacylglycerol and phosphatidic acid (PtdOH) formation was investigated in stimulated human peripheral blood mononuclear cells (PBMC). When human PBMC were first enriched with 12‐HETE, then stimulated by the mitogenic lectin concanavalin A (Con A), the production of PtdOH normally associated with Con A stimulation was markedly increased as compared with non‐enriched cells. The Con‐A‐induced rise in the PtdOH mass was markedly decreased by 1 % ethanol in 12‐HETE‐enriched cells, whereas it was unaffected in control cells stimulated by Con A alone. Furthermore, in [3H]arachidonic‐acid‐labelled cells previously enriched with 12‐HETE, the formation of [3H]arachidonic‐acid‐labelled phosphatidylalcohol was significantly increased upon Con A stimulation, no phosphatidylalcohol being synthesized in non‐enriched cells. Collectively, these results suggest that, in the presence of 12‐HETE, Con A stimulates a phospholipase D activity which was not triggered by Con A alone. These data are consistent with the lack of effect of suramin, reported as a phospholipase D inhibitor, which we observed in cells stimulated by Con A alone and with the suramin‐induced decrease of PtdOH mass in 12‐HETE‐plus‐Con‐A‐treated cells. Moreover, 12–[3H]HETE‐enriched PBMC produced a significant amount of 12–[3H]HETE‐containing PtdOH (0.4% of the total PtdOH) in resting conditions. Upon mitogenic Stimulation by Con A, the phorbol ester tetrade‐canoylphorbol acetate or the anti‐CD3 mAb OKT3, this proportion was decreased to 0.1–0.2%, since the total PtdOH mass was more drastically increased than the 12‐HETE‐containing PtdOH species. Although present in relatively low amount in stimulated cells, 12‐HETE‐containing PtdOH species might have been generated in strategic compartments of the membrane bilayer so that the following events involved in the transduction of the mitogenic signal could be impaired. GC analyses have pointed out drastic variations in the fatty acid composition of PtdOH in non‐enriched and in 12‐HETE‐enriched stimulated cells. Especially PtdOH synthesized in 12‐HETE‐enriched cells upon Con A stimulation contained a higher amount of saturated fatty acids and a lower amount of arachidonic acid than that formed in control cells stimulated with Con A alone. Such saturated PtdOH species with a low arachidonic acid content are very likely to have a low mitogenic potential.
Characterisation of Clusters of α‐Tocopherol in Gel and Fluid Phases of Dipalmitoylglycerophosphocholine
Authors: Quinn Peter J.
Published: September 2004

The effect of α‐tocopherol on the phase behaviour of aqueous dispersions of dipalmitoylglycerophosphocholine has been examined by differential scanning calorimetry, freeze‐fracture electron microscopy, and real‐time X‐ray diffraction methods. The presence of α‐tocopherol in proportions 2.5, 5, 7.5, and 10 mol/100 mol results in a progressive decrease in the temperature of the gel to liquid‐crystalline phase transition from 41.5°C to 36°C and a reduction in transition enthalpy from 35 kJ · mol−1 to 15 kJ · mol−1 phospholipid. The thermal data indicated that the pretransition of the phospholipid is eliminated even in mixtures containing 2.5 mol/100 mol α‐tocopherol. Real‐time X‐ray diffraction measurements using synchrotron radiation performed under identical conditions to the thermal studies showed clear transition sequences of Lβ→Pβ→Lα for all mixtures. The sequence was reversible with hysteresis of 2–3°C on cooling. Low‐angle X‐ray scattering from mixtures in the gel phase showed three lamellar repeat spacings of 6.35, 7.5, and 8.4 nm. The spacing at 6.35 nm was assigned to pure phospholipid from which α‐tocopherol had been phase separated into enriched domains giving lamellar repeat spacings of 7.5 nm and 8.4 nm. Low‐angle diffraction patterns of mixtures in the fluid phase were characterised by two lamellar repeat spacings. The longer spacing of about 6.6 nm was assigned to pure phospholipid and the shorter spacing at about 6.1 nm to an α‐tocopherol‐enriched phase. Electron microscopy of freeze‐fracture replicas of mixtures of phospholipid containing 10mol/100 mol α‐tocopherol thermally quenched from 10°C and 60°C, showed evidence of domain structures within the bilayer plane that appeared to be correlated between successive bilayers in multilamellar dispersions. Calculations of the stoichiometry of phospholipids: α‐tocopherol in the α‐tocopherol‐enriched domains based on enthalpy data and integrated X‐ray scattering intensity gave values of 9.6:1 for the fluid phase and 9.2:1 for the gel phase. This was consistent with a clustering of α‐tocopherol molecules in both gel and liquid‐crystal phases of dipalmitoyl‐glycerophospholcholine in approximately the same stoichiometry.
Peroxidative Interaction of Myoglobin and Myosin
Authors: Hanan Tali , Shaklai Nurith
Published: September 2004

Met‐myoglobin [Fe(III)] was found to induce myosin cross‐linking in the presence of H2O2 [Bhoite‐Solomon, V. & Shaklai, N. (1992) Biochem. Int. 26, 181–189]. To assess the relevance of these findings to cellular pathology, peroxidation of myosin was performed with physiological divalent iron [Fe(II)] myoglobins in the oxy and deoxy forms. Both myoglobin forms were capable of mediating cross‐linking of myosin. Deoxymyoglobin reactivity was similar to that of met‐myoglobin, but the reactivity of oxymyoglobin was retarded compared to deoxymyoglobin. Cross‐linking of myosin occurred under a low flow rate of H2O2 (3 μM/min) and in the presence of excess oxymyoglobin over H2O2, known to diminish the steady state of the myoglobin active heme [ferryl, Fe(IV)] state. The adenosinetriphosphatase activity of myosin was reduced to about half due to cross‐linking. Addition of myoglobin/H2O2 to high myosin concentrations (≥20 μM) turned the solutions into gels, a phenomenon explained by the further formation of intermolecular super cross‐links of soluble myosin. Thus, at cellular ionic strength in which myosin is insoluble, cross‐linking of myosin could still be triggered by myoglobin and H2O2. Based on these data, it is suggested that myoglobin‐induced cross‐linking of myosin and the consequent loss of adenosinetriphosphatase activity may be involved in muscle malfunction under hypoxia when cellular peroxidants increase and the deoxymyoglobin form prevails.
Identification of the Iron‐Sulfur Clusters in a Ferredoxin from the Archaeon Sulfolobus acidocaldarius
Authors: Breton Jacques L. , Duff Jill L. C. , Butt Julea N. , Armstrong Fraser A. , George Simon J. , Pétillot Yves , Forest Eric , Schäfer Günter , Thomson Andrew J.
Published: September 2004

A ferredoxin isolated from the archaeon Sulfolobus acidocaldarius strain DSM 639 has been shown to contain one [3Fe‐4S]1+/0 cluster with a reduction potential of –275 mV and one [4Fe‐4S]2+/1+ cluster with a reduction potential of –529 mV at pH 6.4, in the temperature range 0–50°C. The monomer molecular mass was confirmed to be 10907.5±1.0 Da by electrospray mass spectrometry, as calculated from the published amino acid sequence [Minami, Y., Wakabayashi, S., Wada, K., Matsubara, H., Kerscher, L. & Oesterhelt, D. (1985) J. Biochem. (Tokyo) 97, 745–751], while the holoprotein molecular mass was found to be 11550±1.0 Da. The reduced [3Fe‐4S]0 cluster was also shown by direct electrochemistry and magnetic circular dichroic spectroscopy to undergo a one‐proton uptake reaction as first observed for Azotobacter chroococcum ferredoxin I [George, S. J., Richards, A. J. M., Thomson, A. J. & Yates, M. G. (1984) Biochem. J. 224, 247–251]. The pKa, of the protonation step has been determined by a novel thin film electrochemical method to be 5.8. This is significantly different from the pKa of 7.7 determined for A. vinelundii ferredoxin I [Shen, B., Martin, L. L., Butt, J. N., Armstrong, F. A., Stout, C. D., Jensen, J. M., Stephens, P. J., LaMar, G. N., Gorst, C. M. & Burgess, B. K. (1993) J. Biol. Chem. 268, 25928–25939] and indicates that the polypeptide chain around the [3Fe‐4S] cluster controls this reaction. Although this appears to be only the second reported case of protonation at or near the reduced [3Fe‐4S]0 cluster, its observation in S. acidoculdarius ferredoxin raises the question of the generality of this chemistry for 3Fe clusters. The similarity of the pKa to the estimated intracellular pH of S. acidocaldarius strongly suggests a physiological role for this process.
Purification of Crotonyl‐CoA Reductase from Streptomyces collinus and Cloning, Sequencing and Expression of the Corresponding Gene in Escherichia coli
Authors: Wallace Kimberlee K. , Bao Zhuo‐Yao , Dai Hong , Digate Russell , Schuler Gregory , Speedie Marilyn K. , Reynolds Kevin A.
Published: September 2004

A crotonyl‐CoA reductase (EC 1.3.1.38, acyl‐CoA:NADP+trans ‐2‐oxidoreductase) catalyzing the conversion of crotonyl‐CoA to butyryl‐CoA has been purified and characterized from Streptomyces collinus. This enzyme, a dimer with subunits of identical mass (48 kDa), exhibits a Km, = 18 μM for crotonyl‐CoA and 15 μM for NADPH. The enzyme was unable to catalyze the reduction of any other enoyl‐CoA thioesters or to utilize NADH as an electron donor. A highly effective inhibition by straight‐chain fatty acids (Ki=9.5 μM for palmitoyl‐CoA) compared with branched‐chain fatty acids (Ki>400 μM for isopalmitoyl‐CoA) was observed. All of these properties are consistent with a proposed role of the enzyme in providing butyryl‐CoA as a starter unit for straight‐chain fatty acid biosynthesis. The crotonyl‐CoA reductase gene was cloned in Escherichia coli. This gene, with a proposed designation of ccr, is encoded in a 1344‐bp open reading frame which predicts a primary translation product of 448 amino acids with a calculated molecular mass of 49.4 kDa. Several dispersed regions of highly significant sequence similarity were noted between the deduced amino acid sequence and various alcohol dehydrogenases and fatty acid synthases, including one region that contains a putative NADPH binding site. The ccr gene product was expressed in E. coli and the induced crotonyl‐CoA reductase was purified tenfold and shown to have similar steady‐state kinetics and electrophoretic mobility on sodium dodecyl sulfate/polyacrylamide to the native protein.
An ethnographic study of three mental health triage programs
Authors: Grigg Margaret , Endacott Ruth , Herrman Helen , Harvey Carol
Published: September 2004

ABSTRACT:   Triage processes are commonly used to manage the interface between demand for, and supply of, health services. This dimension of service provision is particularly pertinent for mental health services in Australia, where demand outweighs services available. This paper draws on the experiences of using participant observation to explore mental health triage processes. Findings highlight the complexities of the researcher role and benefits of using an ethnographic approach to explore mental health triage patterns. Insider participant observation brings many challenges but also, in this study, enabled the researcher to uncover some roles and processes underpinning triage decisions in mental health services.
The I‐C‐A‐C framework: Uncovering patients’ experiences
Authors: Chan Zenobia C. Y.
Published: September 2004

ABSTRACT:  The use of metaphors to enhance nursing knowledge and intervention has not been thoroughly addressed in a Chinese context. Use of metaphors helps people transform feelings from the inexpressible to the expressible, to revise their view of their own strengths from unaware to aware, and to expand a one‐dimensional view to a multifaceted one. Based on the therapeutic essence of metaphors, this article proposes the I‐C‐A‐C framework on the use of metaphors, with a case example given to illustrate how nurses can help uncover patients’ illness experiences. The I‐C‐A‐C framework has four strategies: I − Inviting the patients to create and share their metaphors; C − Creating many meanings for the metaphors; A − Analysing the metaphors; amd C − Connecting the patients’ metaphors to their personal context. Limitations and implications of the framework for nursing practice are suggested.
Exploring the impact of the implementation of a nursing clinical development unit program: What outcomes are evident?
Authors: Happell Brenda , Martin Trish
Published: September 2004

ABSTRACT:  Nursing Clinical Development Units have become popular as a framework for the facilitation of the professional development of nursing and to contribute to improved outcomes for consumers of health care services. An exploratory evaluation of the Nursing Clinical Development Unit program implemented by the Centre for Psychiatric Nursing Research and Practice was undertaken using a qualitative approach. This paper focuses on the findings relating to outcomes. A number of positive outcomes were identified including: changes within nursing practices; the development of more positive attitudes by nurses, a greater focus on research utilization and evidence‐based practice; and an increase in professional development activities, including conference presen­tations. Despite these positive findings, the need for more structured evaluation and an increased emphasis on dissemination of findings was identified.
Mental health survivors: your colleagues
Authors: Lawrence Jan
Published: September 2004

ABSTRACT:  An increasing number of mental health survivors or people who have episodes of mental illness (EOMI) are seeking employment and training as mental health workers (

Health Workforce Advisory Committee 2002

). Problems for such individuals, as students and in the workforce, will be discussed with special reference to those who are training to complete the New Zealand National Certification in Mental Health Support Work. This article seeks to encourage health professionals to reassess their roles in regard to supported employment for people who have EOMI and to alert them as to the rising number of people who successfully work as trained professionals within mental health areas and have EOMI. The reader is encouraged to reflect on the recovery approach itself and the journey that people who have EOMI encounter when they choose to enter the workforce. This is especially useful to health professionals working in mental health such as consumer groups and nurses. An example of a student who has EOMI is included and the pseudonym ‘Joe’ is applied to this student to protect his identity.
Evaluating the impact of a preceptorship course on mental health nursing practice
Authors: Charleston Rosemary , Happell Brenda
Published: September 2004

ABSTRACT:  The crisis in the recruitment of nursing graduates into the mental health nursing field dictates the need for assertive and innovative strategies to promote the positive aspects of this field of nursing. A positive clinical experience has been identified as one of the most important determinants of nursing students’ attitudes towards mental health nursing. The Centre for Psychiatric Nursing Research and Practice implemented the course ‘Preceptorship in Psychiatric Nursing’ as a means to increase the skill level within and interest towards the preceptorship role in clinical practice. This paper presents an evaluation of courses conducted between 2000 and 2002. The findings suggest that participants (n = 150) were highly satisfied with the content and delivery of the course, and that it is likely to affect their attitude towards and fulfilment of the preceptorship role.
Bilateral infundibulopelvic stenosis without renal insufficiency: Is surgery necessary?
Authors: GENERAO SUZANNE E , TUNUGUNTLA HARI SIVA GURUNADHA RAO , MAKKER SUDESH P , BUTANI LAVJAY , KURZROCK ERIC A
Published: September 2004

SUMMARY:  The following case describes the clinical course of a patient with bilateral infundibulopelvic stenosis from her initial presentation at age 2 through the age of 14 years. This condition is associated with hypoplasia of segments of the upper collecting system and is characterized by dilated calyces that drain through stenotic infundibulae. Our patient is unique in that, although her renal function has slowly deteriorated with time, she has a persistently non‐obstructive pattern on dynamic imaging studies. Only a minority of patients reported in the literature with this condition progress to renal insufficiency or failure. Although some patients have undergone surgery for presumed obstruction, surgical intervention has no proven benefit. Patients are at risk for hyperfiltration injury and should be followed for the development of hypertension, proteinuria and renal insufficiency. Without evidence of obstruction, medical management remains the cornerstone of treatment.
Interpreting incidence trends for treated end‐stage renal disease: Implications for evaluating disease control in Australia
Authors: STEWART JOHN H , MCCREDIE MARGARET RE , WILLIAMS SHEILA M , MCDONALD STEPHEN P
Published: September 2004

Background:  Five sources of change modify trends in incidence of treated end‐stage renal disease (ESRD): (i) demography; (ii) disease control, comprising prevention and treatment of progressive kidney disease; (iii) competing risks, which encompass dying from untreated uraemia or non‐renal comorbidity; (iv) lead‐time bias; and (v) classification bias. Thus, rising crude incidence of treated ESRD may conceal effective disease control when there has been demographic change, lessening competing risks, or the introduction of bias.

Methods:  Age‐specific incidences of treated ESRD in Australia were calculated from Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry data by indigenous/non‐indigenous status (all causes) and by primary renal disease (non‐indigenous only) for two successive decades, 1982–1991 and 1992–2001.

Results:  We postulate that less competing risks explained much of the increase in treated ESRD in the elderly and Indigenous Australians. The increase in glomerulonephritic ESRD in non‐indigenous Australians could be ascribed mainly to immigration from non‐European countries. There was no significant change in incidence of treated ESRD in Indigenous or non‐indigenous persons aged less than 25 years, in non‐indigenous persons aged 25–64 years for ESRD caused by hereditary polycystic disease or hypertension, or in type 1 diabetics aged over 55 years. End‐stage renal disease from analgesic nephropathy had declined. The increase in treated ESRD caused by type 2 diabetic nephropathy appeared to be multifactorial. Lead‐time/length bias and less competing risks may have concealed a small favourable trend in other primary renal diseases.

Conclusion:  Whether recent disease control measures have had an impact on incidence of treated ESRD is not yet certain, but seems more likely than implied by previous reports.
A CASE OF DUODENAL LIPOMA REMOVED BY ENDOSCOPIC POLYPECTOMY
Authors: Shoji Tuyoshi , Taniwaka Koichi , Goto Hideki , Fukasawa Tomoki , Akaike Hidenori , Tabata Minoru
Published: September 2004

A rare case of duodenal lipoma removed by endoscopic polypectomy is presented herein. A 64‐year‐old female was found to have a polypoid lesion in the duodenum on gastrointestinal endoscopic examination. Endoscopy revealed a submucosal tumor located on the second portion. Endoscopic ultrasonography (EUS) demonstrated a homogenous, hyperechoic mass continuous with the submucosal layer, suggesting a lipoma. Because of the likelihood of the tumor ultimately causing obstruction or bleeding, endoscopic polypectomy was performed. There were no complications after treatment.
ATTEMPT IN GASTROSCOPY TO EXPOSE NARROW FURROWS BETWEEN PACKED FOLDS OF THE GREATER CURVATURE: SIMPLE TECHNIQUE TO AVOID A BLIND SPOT
Authors: Ukawa Shiro , Ukawa Kunio
Published: September 2004

Background:  Occasionally, there are patients in whom the folds of the greater curvature of the stomach are closely packed, resulting in difficulty with endoscopic visualization of the intervening furrows.

Methods:  A simple technique was attempted to avoid such blind spots. This was to slide the scope tip along the furrow or furrows between the folds to attain smoothing in the greater curvature. In the present study, 424 patients required this unfolding maneuver for complete observation. This accounted for 12.5% of 3404 patients examined during the study period. It was found that sliding the scope tip across the folds or applying gentle pressure at a point of the greater curvature also was effective. Possible modification by atropine, given as premedication, is also discussed.

Results:  A marked smoothing effect was achieved in 263 patients accounting for 62.0%, a moderate effect in 125 patients accounting for 29.5%, and a poor effect in 36 patients, which is 8.5%. The background mucosa of the stomach seemed to be related to the degree of effectiveness. Specifically, the cases with widely spread chronic gastritis showed less response to the maneuver.

Conclusions:  Gentle contact with the greater curvature, cleaving the furrows between folds, mild touching in random directions, or applying pressure on a point, resulted in the unexpected flattening of the folds and widening of the narrow furrows in many cases. This phenomenon cannot be explained by mechanical factors alone, and a physiological response, such as an accommodation reflex, is suspected to be playing a role.
SQUAMOUS CELL PAPILLOMA OF THE ESOPHAGUS: CLINICOPATHOLOGICAL STUDY OF 24 CASES
Authors: Oguma Junya , Ozawa Soji , Kitagawa Yuko , Saikawa Yoshiro , Oyama Takashi , Kitajima Masaki
Published: September 2004

Background:  Squamous cell papilloma of the esophagus is considered to be a rare condition; however, the number of cases with this condition reported in recent years has increased, perhaps due to advances in endoscopic diagnosis.

Methods:  We reviewed the clinicopathological features of 26 lesions of squamous cell papilloma of the esophagus in 24 cases seen at our hospital from 1994 to 2003. There were nine men and 15 women, with a mean age of 60.5 years (range, 31–82 years). Six patients had a history of malignant disease in the past. With regard to the presence of other lesions in the esophagus, six patients had hiatal hernia and four had gastroesophageal reﬂux disease.

Results:  Two patients each had two lesions of squamous cell papilloma. There were seven lesions in which inﬂammatory cell inﬁltration was found on hisotological examination, of which four had underlying hiatal hernia; ﬁve lesions were found to have mild dysplasia on histological examination of which three had gastroesophageal reﬂux disease. The median duration of follow up of the cases was 8 months (range, 1–101 months). During the follow‐up period, none of the lesions showed any dramatic change of appearance or malignant transformation.

Conclusion:  In principle, while it may be sufﬁcient to keep patients with squamous cell papilloma of the esophagus under simple follow up, the patients must be investigated to rule out malignancy of other organs, and the small probability of malignant transformation of the tumor must always be borne in mind.
A CASE OF PANCREATIC PSEUDOCYST SUCCESSFULLY TREATED WITH ENDOSCOPIC CYSTGASTROSTOMY USING A NEW THERAPEUTIC ECHOENDOSCOPE
Authors: Kakutani Hiroshi , Hino Syoryoku , Ikeda Keiichi , Uchiyama Yujirou , Sumiyama Kazuki , Kuramochi Akira , Kawamura Muneo , Tajiri Hisao
Published: September 2004

Aim:  A case of an infected pancreatic pseudocyst in which cystgastrostomy was successfully performed with a new therapeutic echoendoscope and ﬂuoroscopic guidance is presented.

Methods:  A curved linear array echoendoscope (GF‐UCT240‐AL5; Olympus) with an instrument channel 3.7 mm in diameter was used in combination with the Aloka SSD‐5000 display unit. It enabled endoscopic video viewing. The cyst puncture was performed using a 1‐mm diathermic needle housed in a 5 Fr Teﬂon tube. Following the endoscopic ultrasound (EUS)‐guided puncture, a 10 Fr stent was placed in the pancreatic pseudocyst without an exchange of endoscope.

Results:  The procedure was well tolerated for the patient and there were no complications. The cyst was resolved and the stent was removed 8 weeks later.

Conclusion:  This new therapeutic echoendoscope may provide a more effective, safer and less time‐consuming method of endoscopic pseudocyst drainage.
Capital Controls: a Political Economy Approach
Authors: Alfaro Laura
Published: September 2004

The paper examines the economic consequences of political conflicts that arise when countries implement capital controls. In an overlapping‐generations model, agents vote on whether to open or close an economy to capital flows. The young (workers) receive income only from wages while the old (capitalists) receive income only from savings. The authors characterize the set of stationary equilibria for an infinite‐horizon game. Assuming dynamic efficiency, when the median representative is a worker (capitalist), capital‐importing countries will open (close) while capital‐exporting countries will close (open). These predicted patterns are consistent with data on liberalization policies over time and across various countries.
The Gains from Trade and Policy Reform Revisited
Authors: Diewert W. Erwin , Woodland Alan D.
Published: September 2004

The primary purpose of the paper is to provide characterizations of the conditions for welfare improvements in several situations that have received very little attention in the existing literature. The first aim is to exhibit the gains that can accrue to a country from the elimination of excess supplies as a result of a policy move from autarky to free trade. The second aim is to characterize the conditions under which the introduction of new goods into the economy will generate welfare gains. The third main area discussed is the extension of the authors’ methodology to a large open economy that can influence its terms of trade. The techniques used to illustrate the gains from eliminating excess supplies and from the introduction of new goods have a much wider applicability; they may be used to obtain and synthesize several welfare results from the literature.
Foreign Investment and the Mediation of Trade Flows
Authors: Swenson Deborah L.
Published: September 2004

How does foreign direct investment affect the trade between nations? While many theories of the multinational firm are based on the premise that foreign production and trade are substitutes, most empirical studies of foreign investment and trade uncover a complementary relationship. This paper shows that the mismatch between theoretical work and empirical findings is a byproduct of data aggregation. When the unique country–industry patterns of mostly OECD country foreign investments in the US are analyzed, predicted substitution patterns are revealed at the data level that roughly corresponds to broad products. The complementary effects of foreign investment on trade emerge at higher levels of aggregation.
Labor Mobility, Trade, and Social Capital
Authors: Schiff Maurice
Published: September 2004

Labor market integration raises welfare in the absence of distortions. This paper examines labor and goods market integration in a general‐equilibrium model with social capital. The findings are: (i) labor market integration has an ambiguous impact on welfare, and raises it if the goods and labor skills are sufficiently different; (ii) compared to Pareto optimum, labor mobility (social capital) is excessively large (depleted); (iii) trade is superior to labor market integration if trading costs are no higher than private migration costs, otherwise the outcome is ambiguous; and (iv) the creation of new institutions in response to labor market integration has an ambiguous impact on welfare.
Vertically Integrated North–South Trade and the Redux Model
Authors: Garcia‐Cebro Juan Antonio , Varela‐Santamaria Ramon
Published: September 2004

The paper uses the framework of Obstfeld and Rogoff's Redux model to study the impact of monetary shocks on exchange rate, terms of trade, and welfare in the context of a North–South trade. The authors show that a relative Northern monetary expansion can depreciate or appreciate its currency depending on whether the consumption elasticity of money demand and the degree of monopolistic distortion are low or high enough. This shock has asymmetric effects on welfare in such a way that “beggar‐thyself” or “beggar‐thy‐neighbor” effects always occur.
From Segmented Markets to Integrated Markets: an Analysis of Economic Integration and Antidumping Legislation
Authors: Ishikawa Jota
Published: September 2004

The paper examines how a movement from segmented markets to integrated markets affects the volume of trade, consumer prices, profits and welfare in a monopoly model. The monopolist can initially discriminate consumer prices among markets with trade costs but has to take arbitrage into account as economic integration proceeds. The analysis provides interesting insights into economic integration and antidumping law. It is shown that the extent of arbitrage and the shape of the marginal cost curve play crucial roles. Surprisingly, it is possible that neither consumers nor the monopolist gains from economic integration, and that antidumping legislation benefits consumers at the expense of producers.
Using GIS to Model Incidence, Prevalence and Spread of Non‐legal Drug Use
Authors: Field Ken , Beale Linda
Published: September 2004

Current methods for estimating the incidence and prevalence of non‐legal drug use tend to be retrospective and are not capable of forecasting spatial characteristics. This paper details the development of a GIS model for forecasting and displaying spatio‐temporal trends in non‐legal drug use. It builds upon a current model that estimates levels of drug use, using GIS to develop and visualise the spatial dimension and to predict levels of use for unknown locations using radial basis functions with a thin spline interpolator. The model is calibrated against known data for the onset and spread of heroin use. Results of validation and cross validation of the interpolated surfaces give some confidence to the accuracy of the method. It provides a first stage in a process to develop more complex models that might be used to examine the introduction of new drug use practices, socio‐economic characteristics of different drug use habits, harm reduction measures or to further examine the role of space in the spread of drug use.
Sea urchin egg preparations as systems for the study of calcium‐triggered exocytosis
Authors: Zimmerberg Joshua , Coorssen Jens R. , Vogel Steven S. , Blank Paul S.
Published: September 2004

This paper reviews recent work in our laboratory on the mechanism of calcium‐triggered exocytosis. Upon echinoderm egg fertilization, cortical secretory vesicle exocytosis is massive and synchronous. By combining physiological and molecular analyses with a variety of purified membrane isolates containing secretory vesicles that fuse to the plasma membrane or each other, we have characterized the final steps of this calcium‐triggered exocytosis. Our kinetic analysis led to a functional definition of the fusion complex whose activation by calcium follows Poisson statistics. The properties of this complex are compared with the properties of the heterotrimeric SNARE protein complex that is present in the cortical vesicle system. Our data do not support the hypothesis that this particular heterotrimeric complex is by itself the biological fusogen.
Pathophysiological basis of orthostatic hypotension in autonomic failure
Authors: Smit Adrianus A. J. , Halliwill John R. , Low Phillip A. , Wieling Wouter
Published: September 2004

In patients with autonomic failure orthostatic hypotension results from an impaired capacity to increase vascular resistance during standing. This fundamental defect leads to increased downward pooling of venous blood and a consequent reduction in stroke volume and cardiac output that exaggerates the orthostatic fall in blood pressure. The location of excessive venous blood pooling has not been established so far, but present data suggest that the abdominal compartment and perhaps leg skin vasculature are the most likely candidates. To improve the orthostatic tolerance in patients with autonomic failure, protective measures that reduce excessive orthostatic blood pooling have been developed and evaluated. These measures include physical counter‐manoeuvres and abdominal compression.