bluuebunny/crossref_metadata_2025 huggingface dataset:
Receptor Binding Transforms the Surface Subunit of the Mammalian C-Type Retrovirus Envelope Protein from an Inhibitor to an Activator of Fusion
Authors: Barnett Anna L. , Cunningham James M.
Published: July 2002

The envelope protein (Env) of murine leukemia viruses (MLVs) is composed of a surface subunit (SU) and a transmembrane subunit (TM), which mediates membrane fusion, resulting in infection. SU contains a discrete N-terminal receptor binding domain (RBD) that is connected to the remainder of Env by a short, proline-rich segment. Previous studies suggest that after receptor binding, the RBD interacts directly with the remainder of Env to trigger fusion (A. L. Barnett, R. A. Davey, and J. M. Cunningham, Proc. Natl. Acad. Sci. USA 98:4113–4118, 2001). To investigate the role of the RBD in activating fusion, we compared infection by several MLVs that are defective unless rescued in
trans
by the addition of soluble RBD to the culture medium. Infection by MLV lacking a critical histidine residue near the N terminus of the viral RBD is dependent on the expression of receptors for both the RBD in the viral Env and the soluble RBD supplied in
trans
. However, infection by MLVs in which the RBD has been deleted or replaced by the ligand erythropoietin are dependent only on expression of the receptor for the soluble RBD. We were able to expand the host range of xenotropic MLV to nonpermissive murine fibroblasts only if the RBD was deleted from the xenotropic viral envelope and the soluble RBD from ecotropic Friend MLV was supplied to the culture medium. These findings indicate that receptor binding transforms the RBD from an inhibitor to an activator of the viral fusion mechanism and that viruses lacking the critical histidine residue at the N terminus of the RBD are impaired at the activation step.
Construction and In Vitro Characterization of Attenuated Feline Immunodeficiency Virus Long Terminal Repeat Mutant Viruses
Authors: Bigornia Luisa , Lockridge Kristen M. , Sparger Ellen E.
Published: July 2002

AP-1- and ATF-binding sites are
cis
-acting transcriptional elements within the U3 domain of the feline immunodeficiency virus (FIV) long terminal repeat (LTR) that serve as targets for cellular activation pathways and may regulate virus replication. We report that FIV LTR mutant proviruses encoding U3 deletions of the ATF-binding sequence exhibited restricted virus expression and replication in both feline lymphocytes and macrophages. In contrast, deletion of the AP-1 site had negligible effects on virus expression and replication. FIV LTR mutant proviruses encoding deletions of both the AP-1 and ATF sites or a 72-bp deletion encompassing the AP-1 site, duplicated C/EBP sites, and ATF sites were severely restricted for virus expression. These results demonstrate that deletion of either the ATF-binding site or multiple
cis
-acting transcriptional elements attenuates FIV. These attenuated FIV mutants provide opportunities to characterize the role of
cis
-acting elements in virus replication in vivo and to test LTR mutants as attenuated virus vaccines.
Both Carboxy- and Amino-Terminal Domains of the Vaccinia Virus Interferon Resistance Gene, E3L, Are Required for Pathogenesis in a Mouse Model
Authors: Brandt Teresa A. , Jacobs Bertram L.
Published: July 2002

The vaccinia virus (VV) E3L gene is responsible for providing interferon (IFN) resistance and a broad host range to VV in cell culture. The E3L gene product contains two distinct domains. A conserved carboxy-terminal domain, which is required for the IFN resistance and broad host range of the virus, has been shown to bind double-stranded RNA (dsRNA) and inhibit the antiviral dsRNA-dependent protein kinase, PKR. The amino-terminal domain, while conserved among orthopoxviruses, is dispensable in cell culture. To study the role of E3L in whole-animal infections, WR strain VV recombinants either lacking E3L (VVΔE3L) or expressing an amino-terminal (VVE3LΔ83N) or carboxy-terminal (VVE3LΔ26C) truncation of E3L were constructed. Whereas wild-type VV had a 50% lethal dose of approximately 10
4
PFU after intranasal infection, and elicited severe weight loss and morbidity, VVΔE3L was apathogenic, leading to no death, weight loss, or morbidity. VVΔE3L was also apathogenic after intracranial injection. Although the amino-terminal domain of E3L is dispensable for infection of cells in culture, both the amino- and carboxy-terminal domains of E3L were required for full pathogenesis in intranasal infections. These results demonstrate that the entire E3L gene is required for pathogenesis in the mouse model.
An N-Terminal Domain of Herpes Simplex Virus Type I gE Is Capable of Forming Stable Complexes with gI
Authors: Rizvi Syed Monem , Raghavan Malini
Published: July 2002

Using limited proteolytic analyses, we show that gE present in soluble herpes simplex virus type 1 gE-gI complexes is cleaved into a C-terminal (CgE) and an N-terminal (NgE) domain. The domain boundary is in the vicinity of residue 188 of mature gE. NgE, but not CgE, forms a stable complex with soluble gI.
Cymbidium Ringspot Tombusvirus Coat Protein Coding Sequence Acts as an Avirulent RNA
Authors: Szittya György , Burgyán József
Published: July 2002

Avirulent genes either directly or indirectly produce elicitors that are recognized by specific receptors of plant resistance genes, leading to the induction of host defense responses such as hypersensitive reaction (HR). HR is characterized by the development of a necrotic lesion at the site of infection which results in confinement of the invader to this area. Artificial chimeras and mutants of cymbidium ringspot (CymRSV) and the pepper isolate of tomato bushy stunt (TBSV-P) tombusviruses were used to determine viral factors involved in the HR resistance phenotype of
Datura stramonium
upon infection with CymRSV. A series of constructs carrying deletions and frameshifts of the CymRSV coat protein (CP) undoubtedly clarified that an 860-nucleotide (nt)-long RNA sequence in the CymRSV CP coding region (between nt 2666 and 3526) is the elicitor of a very rapid HR-like response of
D. stramonium
which limits the virus spread. This finding provides the first evidence that an untranslatable RNA can trigger an HR-like resistance response in virus-infected plants. The effectiveness of the resistance response might indicate that other nonhost resistance could also be due to RNA-mediated HR. It is an appealing explanation that RNA-mediated HR has evolved as an alternative defense strategy against RNA viruses.
Envelope Glycoprotein Incorporation, Not Shedding of Surface Envelope Glycoprotein (gp120/SU), Is the Primary Determinant of SU Content of Purified Human Immunodeficiency Virus Type 1 and Simian Immunodeficiency Virus
Authors: Chertova Elena , Bess, Julian W. , Crise Bruce J. , Sowder Raymond C. , Schaden Terra M. , Hilburn Joanne M. , Hoxie James A. , Benveniste Raoul E. , Lifson Jeffrey D. , Henderson Louis E. , Arthur Larry O.
Published: July 2002

Human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV) particles typically contain small amounts of the surface envelope protein (SU), and this is widely believed to be due to shedding of SU from mature virions. We purified proteins from HIV-1 and SIV isolates using procedures which allow quantitative measurements of viral protein content and determination of the ratios of
gag
- and
env
-encoded proteins in virions. All of the HIV-1 and most of the SIV isolates examined contained low levels of envelope proteins, with Gag:Env ratios of approximately 60:1. Based on an estimate of 1,200 to 2,500 Gag molecules per virion, this corresponds to an average of between 21 and 42 SU molecules, or between 7 and 14 trimers, per particle. In contrast, some SIV isolates contained levels of SU at least 10-fold greater than SU from HIV-1 isolates. Quantification of relative amounts of SU and transmembrane envelope protein (TM) provides a means to assess the impact of SU shedding on virion SU content, since such shedding would be expected to result in a molar excess of TM over SU on virions that had shed SU. With one exception, viruses with sufficient SU and TM to allow quantification were found to have approximately equivalent molar amounts of SU and TM. The quantity of SU associated with virions and the SU:TM ratios were not significantly changed during multiple freeze-thaw cycles or purification through sucrose gradients. Exposure of purified HIV-1 and SIV to temperatures of 55°C or greater for 1 h resulted in loss of most of the SU from the virus but retention of TM. Incubation of purified virus with soluble CD4 at 37°C resulted in no appreciable loss of SU from either SIV or HIV-1. These results indicate that the association of SU and TM on the purified virions studied is quite stable. These findings suggest that incorporation of SU-TM complexes into the viral membrane may be the primary factor determining the quantity of SU associated with SIV and HIV-1 virions, rather than shedding of SU from mature virions.
Systemic, Mucosal, and Heterotypic Immune Induction in Mice Inoculated with Venezuelan Equine Encephalitis Replicons Expressing Norwalk Virus-Like Particles
Authors: Harrington Patrick R. , Yount Boyd , Johnston Robert E. , Davis Nancy , Moe Christine , Baric Ralph S.
Published: July 2002

Norwalk-like viruses (NLVs) are a diverse group of single-stranded, nonenveloped, positive-polarity RNA viruses and are the leading cause of epidemic acute gastroenteritis in the United States. In this study, the major capsid gene of Norwalk virus, the prototype NLV, has been cloned and expressed in mammalian cells using a Venezuelan equine encephalitis (VEE) replicon expression system. Upon infection of baby hamster kidney (BHK) cells with VEE replicon particles (VRPs), the Norwalk virus capsid proteins self-assemble to generate high titers of Norwalk virus-like particles (VLPs) that are morphologically and antigenically analogous to wild-type Norwalk virus. Mice inoculated subcutaneously with VRPs expressing the Norwalk virus capsid protein (VRP-NV1) developed systemic and mucosal immune responses to Norwalk VLPs, as well as heterotypic antibody responses to the major capsid protein from another genogroup I NLV strain (NCFL) isolated from a recent outbreak. A second Norwalk virus capsid clone (NV2) containing three amino acid codon mutations from the NV1 clone was also expressed using VEE replicons (VRP-NV2), but upon infection of BHK cells failed to confer VLP self-assembly. Mice inoculated with VRP-NV2 elicited reduced systemic and mucosal immune responses to Norwalk VLPs, demonstrating the importance and potential utility of endogenous VLP presentation for maximum immune induction. Inoculation with either VRP-NV1 or VRP-NV2 resulted in serum antibody responses far superior to the induction in mice dosed orally with VLPs that were prepared using the VEE-NV1 replicon construct, a regimen similar to current models for NLV vaccination. Expression of NLV VLPs in mammalian cells offers a powerful approach for the design of novel NLV vaccines, either alone or in combination with current vaccination models.
Chemometric Analysis of Substituent Effects. II. Relation Between Hammett Substituent Constants σm and σp and a New Model for Quantitative Description of Substituent Effects
Authors: Pytela Oldřich
Published: July 2002

The paper presents values of 25 substituent constants σi obtained by optimizing 46 data series of dissociation constants of substituted benzoic acids in various media. The constants σi fulfil the general relation between the substituent constants of the Hammett type in meta and para positions enabling the description of substituent effects from both positions at the same time by a single constant. The Hammett substituent constants are interpreted by means of the σi constants with an accuracy better than 0.03 units. In addition to it, the validity of general relationship between σp and σm was verified on a set of 56 substituents with the prediction accuracy of 0.06 units for σp, and after excluding the probably incorrectly parametrized substituents NHCOC6H5, CH3S, and F the accuracy has improved to 0.05 units (98% of interpreted variability). The given relationship has served as a basis for suggesting a new model of transfer of substituent effects to a reaction centre: the model involves both the Hammett equation and the Yukawa-Tsuno equation and explains their background. The suggested model uses generalized transmission coefficients to separately describe the transformation of a single primary substituent effect - depending on its structure - into one inductive and two resonance effects which are transmitted through two independent channels to the reaction centre and here transformed into the resulting observable effect. From the model it follows that the substituent constant σp is not a substituent constant in the true sense of the word since it involves the characteristics of skeleton and of reaction centre.
Radical Additions of Tertiary Amines to Chlorotrifluoroethylene
Authors: Bárta Milan , Hampl František , Liška František , Dědek Václav
Published: July 2002

Radical addition of ethyldimethylamine, cyclohexyldimethylamine, 1-methylpyrrolidine, 1-methylpiperidine, 1-methylperhydroazepine and 1-methylmorpholine to chlorotrifluoroethylene afforded 1 : 1 and 1 : 2 adducts containing 2-chloro-1,1,2-trifluoroethyl groups in the α- or α,α'-positions. Further reaction products were 1 : 2 telomers and secondary products arising by reduction of the chlorine atom in CHFCl groups by tertiary amines. The reaction course and mass and NMR spectra of the products are discussed.
Inclusion Compounds of Tetracyano Complexes and Their Electrical Properties
Authors: Reháková Mária , Sopková Anna , Šály Vladimír
Published: July 2002

The presence of iodine and iodide ions in tetracyanonickelates inclusion compounds with the general formula Ni(B)mNi(CN)4 . n H2O (B = NH3 or ethylenediamine) changes the properties of these compounds. High frequency conductance measurements in the range of 10 - 105 Hz show that the products with ethylenediamine ligands have a higher electrical conductivity than those with NH3 ligands. The differences in the electrical properties between the compounds studied are mainly caused by chemical composition, structure and morphology.
Synthesis of Acyclic Nucleotide Analogues Derived from 2-(Aminomethyl)adenine and 2-(Aminomethyl)hypoxanthine
Authors: Hocek Michal , Masojídková Milena , Holý Antonín
Published: July 2002

Synthesis of a series of 2-(aminomethyl)-9-(2-phosphonomethoxyalkyl)adenines VI and hypoxanthines VII is reported. The protected 2-(aminomethyl)adenine I was selectively alkylated with [bis(2-propoxy)phosphonylmethoxy]alkyl chlorides or tosylates II and the obtained 9-[bis(2-propoxy)phosphonylmethoxy]alkyl-2-(benzyloxycarbonyla minomethyl)adenines IV were oxodeaminated to give the corresponding hypoxanthine derivatives V. The intermediates IV and V were completely deprotected by treatment with iodotrimethylsilane under formation of the title compounds VI and VII.
13C and 119Sn NMR Spectra of Some Mono-n-butyltin(IV) Compounds
Authors: Pejchal Vladimír , Holeček Jaroslav , Nádvorník Milan , Lyčka Antonín
Published: July 2002

The 13C and 119Sn NMR spectra of some mono-n-butyltin(IV) compounds in solution of non-coordinating (CDCl3 and CD3NO2) and coordinating ((CD3)2SO and C5D5N) solvents have been studied. From the values of delta(119Sn), 1J(119Sn,13C) and additional 13C NMR parameters an evaluation of the coordination numbers of the central tin atom and the shapes of coordination polyhedra around the tin atom has been carried out.
Molecular Diversity and Libraries of Structures: Synthesis and Screening
Authors: Rinnová Markéta , Lebl Michal
Published: July 2002

Library, or molecular diversity, approaches are a progressive tool in contemporary investigation of biological interactions and drug discovery. All library approaches include certain degree of rationality and cannot be therefore classified as random or irrational techniques. Reviewed techniques are complementary to so called "rational design"; they can serve either as a tool to generate a lead, or, on the other hand, to optimize a "designed" lead by rapid evaluation of structure-activity relationships. Combinatorial approaches are based on either a random or multiple principle which enables production of large number of diverse molecular structures that can be simultaneously screened and evaluated in a biological assay to find an optimal interacting molecule.
Extra-Column Effects in Determination of Rate Parameters by the Chromatographic Method
Authors: Šolcová Olga , Schneider Petr
Published: July 2002

It was shown that the sampling loop, detector and connecting elements in the chromatographic set-up for determination of transport parameters by the dynamic method significantly influence the response peaks from columns packed with porous or nonporous particles. A method, based on the use of convolution theorem, was developed which can take these effects into account. The applicability of this method was demonstrated on the case of axial dispersion in a single-pellet-string column (SPSR) packed with nonporous particles. It is possible to handle also responses from columns packed with porous particles by a similar procedure.
Synthesis of (15E)-3β-Hydroxyandrost-5-ene-15,17-dione 15-(O-Carboxymethyl)oxime; The New Hapten for 3β-Hydroxyandrost-5-en-17-one (Dehydroepiandrosterone, DHEA)
Authors: Fajkoš Jan , Pouzar Vladimír , Černý Ivan
Published: July 2002

From 17β-hydroxy-15β-[(4-methoxyphenyl)methoxy]androst-5-en-3β-yl acetate (1) by acetylation, removal of (4-methoxyphenyl)methyl group, and oxidation with Jones reagent, 15-oxoandrost-5-ene-3β,17β-diyl 3,17-diacetate (4) was prepared. (O-Carboxymethyl)hydroxylamine treatment and subsequent diazomethane methylation gave methyl ester of corresponding 15-(O-carboxymethyl)oxime derivative. Partial acid hydrolysis gave 3-acetate as a minor product, therefore the major 17-acetate was transformed in two steps into the 3-benzoate. Oxidation at position 17 and subsequent deprotection gave for both products final (15E)-3β-hydroxyandrost-5-ene-15,17-dione 15-(O-carboxymethyl)oxime (14), but for 3-acetyl derivative the whole synthesis is shorter and gave higher yield.
Oxidation of Toluene Over V2O5-Sb2O3/TiO2 Catalysts. Enhancement of Selectivity Towards Benzoic Acid
Authors: Antol Marcel , Kaszonyi Alexander , Hronec Milan
Published: July 2002

The effect of reaction parameters, additives and cooxidants on the selectivity of toluene oxidation to benzoic acid in the vapor phase has been studied. The presence of ethanol as cooxidant in the reaction stream does not improve the selectivity of toluene oxidation towards partial oxidation products via methyl group oxidation. However, the presence of carbon dioxide has a positive effect on the selectivity to benzoic acid formation. The catalysts were characterized by temperature programmed reduction.
Peroxidases from Tulip Bulbs (Tulipa fosteriana, L.) Oxidize Xenobiotics NNitrosodimethylamine and N-Nitroso-N-methylaniline in vitro
Authors: Stiborová Marie , Hansíková Hana
Published: July 2002

Tulip bulbs (Tulipa fosteriana, L.) contain peroxidases catalyzing the oxidation of the xenobiotics N-nitrosodimethylamine (NDMA) and N-nitroso-N-methylaniline (NMA). Three anionic (A1, A2, A3) and four cationic (B, C, D, E) peroxidases were purified from this tissue, partially characterized and used for kinetic studies. Demethylation of NDMA and NMA producing formaldehyde is catalyzed by one anionic (A1) and three cationic (C, D, E) peroxidases. The oxidation of NDMA by tulip peroxidases exhibits the Michaelis-Menten kinetics. The apparent Michaelis constant and the maximal velocity values for this substrate were determined. On the other hand, non-Michaelian kinetics for the NMA oxidation were observed with tulip peroxidases. The most abundant cationic peroxidase (peroxidase C) was used for detailed enzymatic studies. In addition to formation of formaldehyde, methylaniline, aniline, 4-aminophenol and phenol were found to be metabolites formed from NMA. Phenol was formed presumably by N-demethylation via a benzenediazonium ion, while methylaniline, aniline and 4-aminophenol were products of denitrosation of the substrate. The efficiencies of plant peroxidases to oxidize NDMA and NMA in vitro are compared with those of cytochromes P450 and discussed.
Synthesis and Structure of Noncoordinated Curtis Macrocycle as a Free Base and Dihydrobromide Dihydrate
Authors: Rohovec Jan , Vojtíšek Pavel , Lukeš Ivan
Published: July 2002

5,7,7,12,14,14-Hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene (1) (Curtis macrocycle) was synthesized and studied by X-ray diffraction and NMR spectroscopy. In addition, a product of its decomposition 5,7,7-trimethyl-2,3,6,7-tetrahydro-1,4-diazepine (2) was found and identified by NMR spectroscopy. The X-ray structure of 1·H2O and 1·2 HBr·2 H2O is given.
Cross-Interaction Constants. A Mechanistic Tool
Authors: Lee Ikchoon , Lee Hai Whang
Published: July 2002

The cross-interaction constant, ρij, is a second derivative parameter representing a change in the intensity of interaction between the two reacting partners (or fragments) i and j in a reaction. It can be either an activation or a reaction parameter. The sign and magnitude of ρij have important mechanistic significances and are useful as a tool for the studies of organic reaction mechanism. We have presented several more important applications of the cross-interaction constants. A review with 42 references.
Organic Sonoelectrochemistry on Mercury Pool Electrode
Authors: Klíma Jiří , Ludvík Jiří
Published: July 2002

So far, the influence of sonication on the electrolytic current was studied only at solid or rather miniaturized mercury electrodes. The presented paper reports on sonoelectrochemical experiments at a liquid mercury pool electrode. Two sonoelectrochemical cells have been developed and tested. It was shown that during sonication, the electrolytic current increases in a number of individual peaks representing short local enhancements of current density due to vigorous local mass transfer and instantaneous increase of fresh electrode surface. Both these effects are caused by microjets of solution formed during violent unsymmetric collapses of cavitation bubbles in the close vicinity of the electrode surface. The newly formed electrode surface and the decrease in the diffusion layer thickness were estimated and discussed. An example is presented where the sonication is used for destruction of a film of products formed during electrolysis of cysteine, that otherwise rapidly inhibits continuation of the electrode process.
Ligand Field Model and d-d Spectra of dN Metallocene Complexes
Authors: Pavlík Ivan , Fiedler Josef , Vinklárek Jaromír , Pavlišta Martin
Published: July 2002

Complete ligand field calculations, including spin-orbit coupling, have been carried out for bent d1 metallocene complexes, [M(Cp)2Ln] (Cp = η5-cyclopentadienyl, n = 1 or 2), in C2v symmetry. Using the strong-field coupling formalism (with exclusion of spin-orbit coupling) the full energy matrices for d2, d3, and d4 bent metallocenes were constructed in terms of four ligand field splitting parameters and two Racah interelectronic repulsion parameters (only d2 energy matrices are presented here). The bonding in the bent d1 C2v M(Cp)2 fragment was analyzed from the point of view of the ligand field model. The experimental d-d transition energies of two d1 metallocene dichlorides, vanadocene and niobocene dichlorides, have been assigned, the values of four one-electron ligand field splitting parameters determined and the effect of spin-orbit coupling estimated. The ground state of both d1 metallocene dichlorides has shown to be 2A(111), the d-orbital energy order being 1a1 < b1 < b2 < 2a1 < a2. Finally, the prediction of d-d spectra for d2, d3, and d4 bent metallocene complexes is presented.
Stripping Analysis Using Ion-Transfer Voltammetry at Liquid/Liquid Interface
Authors: Senda Mitsugi , Katano Hajime , Kubota Yuko
Published: July 2002

Principles and theory of stripping ion-transfer voltammetry at the organic solvent (O)/water (W) interface are described, in which a thin O-film is used to preconcentrate an ionic substance by electroextraction followed by stripping analysis using linear sweep voltammetry or normal pulse voltammetry. For ease of handling, the thin O-film was gelled by adding poly(vinyl chloride) to make an O-gel electrode. Lead(II), cadmium(II) and zinc(II) ions behave reversibly or quasi-reversibly in voltammetric transfer at the O/W interface assisted by 5,6-diphenyl-3-(2-pyridyl)-1,2,4-triazine (DPT) present in the O-phase. Thus, these ions at trace levels can be determined using stripping ion-transfer voltammetry with the O(DPT)-gel electrode. The detection limit was as low as a few tens of nmol/l of these ions. Simultaneous determination of two or more ions is possible when their half-wave potentials of ion transfer are reasonably separated.
Danish type gelsolin related amyloidosis: 654G-T mutation is associated with a disease pathogenetically and clinically similar to that caused by the 654G-A mutation (familial amyloidosis of the Finnish type)
Authors: Maury Carl Peter J , Liljeström Mikko , Boysen Gudrun , Törnroth Tom , de la Chapelle Albert , Nurmiaho-Lassila Eeva-Liisa
Published: July 2002

Background—Familial amyloidosis of the Finnish type (FAF, Finnish hereditary amyloidosis) is caused by a 654G-A mutation in the gelsolin gene on chromosome 9 resulting in the expression of mutant Asn-187 gelsolin which is abnormally proteolytically processed generating amyloidogenic fragments that polymerise into amyloid fibrils. We have recently shown that in a Danish and a Czech family with a clinical syndrome similar to FAF, including corneal lattice dystrophy, cranial neuropathy and skin changes, the disease is caused by another mutation at the same position, namely 654G-T predicting a Tyr-for-Asp substitution at 187 in secreted gelsolin.

Aim—To undertake a closer examination of the Danish subtype of FAF and report immunohistochemical and biochemical findings.

Results—Immunostaining of plasma gelsolin isolated from heterozygous FAF of the Danish subtype revealed a pattern similar to that found in FAF-Asn 187. The > 60 kDa gelsolin species contain an epitope characteristic of the amyloid forming region as revealed by an amyloid specific antibody, whereas the ∼50 kDa fragments are devoid of it. Compared with the wild-type gelsolin peptide (Asp-187), the corresponding mutant peptide (Tyr-187) showed dramatically increased fibrillogenicity as revealed by quantitative thioflavine-T based fluorimetry; ultrastructurally, amyloid-like fibrils were formed by the mutant peptide. Immunohistochemistry showed that antibodies directed against residues 231–242 of secreted gelsolin, representing the carboxy terminus of the sequence forming the amyloid protein (residues 173–243) laid down in the tissues in a fibrillar form in FAF, specifically labelled the amyloid deposited in rectum and skin in the Danish (654G-T) subtype.

Conclusions—The 654G-T mutation in the gelsolin gene gives rise to an amyloid disease clinically and pathogenetically similar to that caused by the 654G-A mutation.
Indomethacin induced psychosis
Authors: Tharumaratnam D , Bashford S , Khan S A
Published: July 2002

Indomethacin is a commonly prescribed non-steroidal anti-inflammatory drug. While its adverse effects on gastrointestinal and renal systems are well described, its central nervous system effects are less well known. This case report describes an elderly man, prescribed indomethacin for gout, who presented with psychosis.
Audit of a nurse endoscopist based one stop dyspepsia clinic
Authors: Melleney E M-A , Willoughby C P
Published: July 2002

As a response to the UK Health Department’s “two week cancer wait” initiative a one stop dyspepsia clinic based on a nurse endoscopist was introduced, and the first 100 cases attending this clinic have been audited. After referral on a purpose designed form, patients were assessed by a gastroenterologist and then investigated at the same visit—where possible and appropriate—by endoscopy or ultrasound scan. All endoscopies were performed by a trained nurse specialist.

Of the 100 patients, 84 were gastroscoped the same day and 11 had an ultrasound scan. Inappropriate tests were avoided in 16% of referrals. The commonest endoscopic diagnoses were minor oesophageal or gastroduodenal inflammation (64% of gastroscopies). Only six oesophageal or gastric cancers were found—all at an advanced stage—and three further malignancies were diagnosed. Only a minority (12%) of the patients with “alarm symptoms” had cancer. The waiting time for an appointment rose progressively during the first six months of the clinic.

The system was popular with patients as most of them (70%) were dealt with at a single hospital attendance. Basing the endoscopy practice on a trained nurse specialist not only facilitated the creation of the service by maximising the use of scarce resources, but also improved communication and overall management of patients.
Comprehensive tobacco control policies and the smoking behaviour of Canadian adults
Authors: Stephens Thomas , Pederson Linda L , Koval John J , Macnab Jennifer
Published: July 2002

OBJECTIVE

To examine the associations of cigarette prices, restrictions on public smoking, and health education with the odds of adult smoking and amount smoked daily.

DESIGN

Multi-level analysis of adult (age 25+) smoking patterns in Canada's National Population Health Survey, after adding administrative data on prices, bylaws, and health education according to the survey respondent's place of residence.

SETTING/SUBJECTS

Population based sample of Canadians age 25+ in households (n = 14 355).

OUTCOME MEASURES

Smoking status, amount consumed daily.

ANALYSIS

Logistic regression for smoking status, multiple regression for amount smoked, with controls for age, education, marital status; separate analyses for men and women.

RESULTS

Cigarette prices were positively associated with the odds of being a non-smoker and negatively with amount smoked, for adults of both sexes. Per capita health education expenditures were positively associated with the odds of being a non-smoker and negatively with amount smoked—formen but not women. The restrictiveness of municipal bylaws limiting public smoking was positively associated with the odds of being a non-smoker and negatively with amount smoked—forwomen but not men.These results are independent of age, education, and marital status.

CONCLUSIONS

To be effective, tobacco control must comprise a mix of strategies as men and women respond differently to health education and restrictions on public smoking; taxation, reflected in higher cigarette prices, is the only one of these measures related to smoking for both sexes. This model permits calculations of the level of increase in each measure that is required to reduce the prevalence of smoking by a specified amount.
Stockenvironment recruitment models for Norwegian spring spawning herring (Clupea harengus)
Authors: Fiksen Øyvind , Slotte Aril
Published: July 2002

Different stockenvironment recruitment models for Norwegian spring spawning herring (Clupea harengus) are fitted to a time series of spawning stock, recruitment, and temperature data extending back to 1907. In addition to the traditional temperature index from the Barents Sea (the average annual temperature in the Kola transect), we also developed a new index based on the temperature in the larval drift trajectories during early larval life. The models show highly significant effects of both spawning stock and temperature. The inclusion of the temperature term in the stockrecruitment models removes the autocorrelation from the residuals and improves their explanatory ability by 69%. We explore the interdependence between recruitment success and subsequent spawning stock biomass and conclude that this is not likely to generate the stockrecruitment relationship. Our analysis suggests that the collapse of the Norwegian spring spawning herring stock in the period 19501970 was not caused by reduced recruitment, but by the drop in spawning stock biomass induced by the increased fisheries in this period.
The endothermic nature of the binding of anionic bile salts to a cationic adsorbent
Authors: Williams Celia K , Galley William C , Brown G Ronald
Published: July 2002

The binding of a hydrophobic bile salt, sodium chenodeoxycholate, by a polyacrylamide with N,N,N-trimethylammonium dodecyl chloride (QPDA12) pendant groups was studied to evaluate the thermodynamic parameters associated with the binding. The Langmuir equation was used in interpreting the data obtained from HPLC measurements. An increase in binding affinity was observed with increasing temperature indicating that the driving force for binding is derived from an increase in entropy (ΔS° = 253 J mol1K1) despite the positive, or unfavourable, enthalpy change (ΔH° = 53 kJ mol1). The positive thermodynamic parameters associated with the binding suggest that the disruption of hydrophobic and (or) ionic hydration associated with the bile salts and cationic polymer is the driving force for the binding.Key words: bile salts, endothermic binding, polymer sorbents, solvent randomization.
MARTIN-LÖF'S TYPE THEORY AS AN OPEN-ENDED FRAMEWORK
Authors: TSUKADA YASUYUKI
Published: July 2002

This paper treats Martin-Löf's type theory as an open-ended framework composed of (i) flexibly extensible languages into which various forms of objects and types can be incorporated, (ii) their uniform, effectively given semantics, and (iii) persistently valid inference rules. The class of expression systems is introduced here to define an open-ended body of languages underlying the theory. Each expression system consists of two parts: the computational part is a structured lazy evaluation system with a bisimulation-like program equivalence; the structural part is a system of strictly positive inductive definitions for type constructors in terms of partial equivalence relations. Types and their objects are uniformly and inductively constructed from a given expression system as a type system, which can provide a semantics of the theory. Building on these concepts, this paper presents two main results. First, all the inference rules of the theory are sound; that is, they remain valid in every type system built from an extension of an initial expression system. This result gives a characterization of the class of types that can be introduced into the theory. Second, each type system is complete with respect to the underlying bisimulation-like program equivalence. This result provides a useful form of type-free equational reasoning in the theory.
MEMBRANE COMPUTING AND ONE-WAY FUNCTIONS
Authors: OBTUŁOWICZ ADAM
Published: July 2002

There are presented certain membrane systems for computing the inverse of one-way functions in a polynomial time. The membrane systems are derived from some mathematical models of natural processes investigated in biochemistry and they have been introduced by Gh. Păun.
QUANTIZED ELECTROMAGNETIC FIELD ON A MANIFOLD
Authors: DIMOCK J.
Published: July 2002

We develop the quantization of the electromagnetic field on an arbitrary globally hyperbolic Lorentzian manifold with a compact Cauchy surface.
A FUNCTIONAL REPRESENTATION FOR NON-COMMUTATIVE C*-ALGEBRAS
Authors: CIRELLI RENZO , MANIÀ ALESSANDRO , PIZZOCCHERO LIVIO
Published: July 2002

We obtain a representation of non commutative C*-algebras as function algebras on the pure state space, with a convenient product. This construction is an extension of the classical functional representation of commutative C*-algebras.
ON THE GENUS EXPANSION IN THE TOPOLOGICAL STRING THEORY
Authors: EGUCHI TOHRU , YAMADA YASUHIKO , YANG SUNG-KIL
Published: July 2002

A systematic formulation of the higher genus expansion in topological string theory is considered. We also develop a simple way of evaluating genus zero correlation functions. At higher genera we derive some interesting formulas for the free energy in the A1 and A2 models. We present some evidence that topological minimal models associated with Lie algebras other than the A-D-E type do not have a consistent higher genus expansion beyond genus one. We also present some new results on the CP1 model at higher genera.
Resonant Decay Near an Accumulation Point
Authors: King Christopher , Waxler Roger
Published: July 2002

We consider the quantum mechanics of a model system in which meta-stable states arise through perturbation of a sequence of embedded simple eigenvalues with an embedded accumulation point. It is shown that the embedded eigenvalues become resonances in the perturbed system. These resonances also accumulate, and the position of the accumulation point is unchanged. The positions of the resonances are estimated uniformly up to the accumulation point. The meta-stable states associated with these resonances have the usual approximately exponential decay with time. Some applications to physical models are discussed.
SYMPLECTIC CONNECTIONS AND EXOTIC HOLONOMY
Authors: CHI QUO-SHIN
Published: July 2002

We show that exotic holonomies arise naturally from torsion-free sympletic connections.
ON -K2 FOR NORMAL SURFACE SINGULARITIES
Authors: CHEN HAO , ISHII SHIHOKO
Published: July 2002

In this paper we show the lower bound of the set of non-zero -K2 for normal surface singularities establishing that this set has no accumulation points from above. We also prove that every accumulation point from below is a rational number and every positive integer is an accumulation point. Every rational number can be an accumulation point modulo ℤ. We determine all accumulation points in [0, 1]. If we fix the value -K2, then the values of pg, pa, mult, embdim and the numerical indices are bounded, while the numbers of the exceptional curves are not bounded.
THE EFFECT OF SOCIAL ALLIANCE AND DISRUPTION ON A SIMPLE AGING MODEL
Authors: SHIMADA TAKASHI
Published: July 2002

The social effects of wolf pack survival are simulated by combining the Makowiec model with Stauffer's simple aging model.
VISUALIZATION OF THE TIME-DEPENDENT CORRELATED WAVEFUNCTIONS OF POSITRON–HYDROGEN SCATTERING SYSTEM
Authors: ODERO D. O.
Published: July 2002

Time-dependent approach has been applied to positron–hydrogen scattering. The initial wavefunction of the system in this approach is expanded in terms of three-dimensional dynamical wavefunctions to include all higher angular momenta by solving a set of three coupled differential equations. The entire contributing scattering channels are automatically included in this approach. Therefore, it resolves the problems at the intermediate energies where the positronium-formation is important. The visualization of the two-particle correlated (angular dependent) wavefunction of the system as it evolves has been presented and provides quantitative analysis of the positronium-formation and ionization processes as they occur. The positron impact transfer (combined positronium-formation and ionization) probabilities obtained from the final wavefunction compares very well with those of time-dependent converged close-coupling calculations.
WORLD SHEET LOGARITHMIC CFT IN AdS STRINGS, GHOST-MATTER MIXING AND M THEORY
Authors: KOGAN IAN I. , POLYAKOV DIMITRI
Published: July 2002

We discuss several closely related concepts in the NSR formulation of superstring theory. We demonstrated that recently proposed NSR model for superstrings on AdS 5× S5 is described by the world sheet logarithmic conformal field theory (LCFT). The origin of LCFT on a world sheet is closely connected to the matter-ghost mixing in the structure of a brane-like vortex operators. We suggest a dynamical origin of M theory as a string theory with an extra dimension given by bosonized superconformal ghosts.
RELATIONS OF TWO TRANSVERSAL SUBMANIFOLDS AND GLOBAL MANIFOLD
Authors: YANG GUO-HONG , FENG SHI-XIANG , NI GUANG-JIONG , DUAN YI-SHI
Published: July 2002

In Riemann geometry, the relations of two transversal submanifolds and global manifold are discussed without any concrete models. By replacing the normal vector of a submanifold with the tangent vector of another submanifold, the metric tensors, Christoffel symbols and curvature tensors of the three manifolds are connected at the intersection points of the two submanifolds. When the inner product of the two tangent vectors of submanifolds vanishes, some corollaries of these relations give the most important second fundamental form and Gauss–Codazzi equation in the conventional submanifold theory. As a special case, the global manifold which is Euclidean is considered. It is pointed out that, in order to obtain the nonzero energy–momentum tensor of matter field in a submanifold, there must be the contributions of the above inner product and the other submanifold. Generally speaking, a submanifold is closely related to the matter fields of the other submanifold and the two submanifolds affect each other through the above inner product.
ON THE HOLOMORPHICALLY FACTORIZED PARTITION FUNCTION FOR ABELIAN GAUGE THEORY IN SIX DIMENSIONS
Authors: GUSTAVSSON ANDREAS
Published: July 2002

We use holomorphic factorization to find the partition functions of an Abelian two-form chiral gauge-field on a flat six-torus. We prove that exactly one of these partition functions is modular invariant. It turns out to be the one that previously has been found in a Hamiltonian formulation.
NON-ABELIAN MEDIUM EFFECTS IN QUARK–GLUON PLASMA
Authors: CHEN JI-SHENG , LI JIA-RONG , ZHUANG PENG-FEI
Published: July 2002

Based on the kinetic theory, the non-Abelian medium property of hot Quark–Gluon Plasma is investigated. The nonlinearity of the plasma comes from two aspects: The nonlinear wave–wave interaction and self-interaction of color field. The non-Abelian color permittivity is obtained by expanding the kinetic equations to third order. As an application, the nonlinear Landau damping rate and the nonlinear eigen frequency shift are calculated in the longwave length limit.
A SPECTRAL APPROACH TO YANG-MILLS THEORY
Authors: ESPOSITO GIAMPIERO
Published: July 2002

Yang–Mills theory in four dimensions is studied by using the Coulomb gauge. The Coulomb gauge Hamiltonian involves integration of matrix elements of an operator [Formula: see text] built from the Laplacian and from a first-order differential operator. The operator [Formula: see text] is studied from the point of view of spectral theory of pseudo-differential operators on compact Riemannian manifolds, both when self-adjointness holds and when it is not fulfilled. In both cases, well-defined matrix elements of [Formula: see text] are evaluated as a first step towards the more difficult problems of quantized Yang–Mills theory.
NEUTRON STARS AND THE FERMIONIC CASIMIR EFFECT
Authors: MAGIERSKI PIOTR , BULGAC AUREL , HEENEN PAUL-HENRI
Published: July 2002

The inner crust of neutron stars consists of nuclei of various shapes immersed in a neutron gas and stabilized by the Coulomb interaction in the form of a crystal lattice. The scattering of neutrons on nuclear inhomegeneities leads to the quantum correction to the total energy of the system. This correction resemble the Casimir energy and turn out to have a large influence on the structure of the crust.
COEXISTENCE OF CHARGES TRAPPED IN LOCAL LATTICE DISTORTIONS AND FREE CARRIERS IN CUPRATES
Authors: CATAUDELLA V. , DE FILIPPIS G. , IADONISI G. , BIANCONI A. , SAINI N. L.
Published: July 2002

The interplay of strong local electron-lattice and electron-electron interaction is analyzed in the two-dimensional Hubbard-Holstein model using an effective single band Hamiltonian. The effect of the strain field acting on the CuO2 plane and the local cooperative pseudo Jahn Teller vibronic electron-lattice coupling appropriate to cuprate superconductors at optimum doping (i.e.; at doping larger than 1/8) are included via the effective next near neighbor electronic hopping integral t′ (determined by the strain field) close to the local vibronic frequency ω0 (involved in the pseudo Jahn Teller electron lattice coupling). The system shows a characteristic feature of the physics of complex systems, the competition and fluctuation between two states: 1) a first phase of charges self trapped in domains with local lattice distortions (a generalization to a many polaron system of the idea of single intermediate polaron) and 2) a second phase of free carriers.
THE CLUSTER SPIN-GLASS PHASE IN La2-xMxCuO4 (M=Sr OR Ba) AS AC PRECURSOR OF STRIPES
Authors: PAOLONE A. , CORDERO F. , CANTELLI R. , FERRETTI M.
Published: July 2002

A cluster spin-glass transition has been identified in La 1.97 Ba 0.03 CuO 4, thanks to the analogies of the acoustic spectrum of this sample with that of La 2-x Sr x CuO 4 (x=0.03 and x=0.06), which has a well established cluster spin-glass phase. Our measurements are in good agreement with the presence of antiferromagnetically correlated clusters which are separated by hole rich boundaries. These "charge rivers" are thought to be the precursors of stripes.
SELF-ORGANIZED NETWORKS AS A REPRESENTATION OF QUANTUM STATISTICS
Authors: BIANCONI GINESTRA
Published: July 2002

A new class of self organized networks is described that is relevant to understand the emerging order in a large number of complex systems such as growing biological systems, the web, and heterogeneous phases of correlated condensed matter systems formed by doping. The Bose and Fermi quantum distributions are shown to be the right tool to describe the two extreme limit distributions, the fermionic Cayley-tree network and the bosonic scale-free network. In this new large class of self-organized networks the two different types of self organization coexists, maintaining the same 'ergodic' nature and are described by a 'mixed' quantum distribution.
PHOTOEMISSION FROM ORDERED STRIPE PHASES
Authors: MARKIEWICZ R. S. , KUSKO C.
Published: July 2002

A phase separation model for stripes has found good agreement with photoemission experiments and with other studies which suggest a termination of the striped phase in the slightly overdoped regime. Here the model is extended in a number of respects. In particular, a discussion of the nature of the charged stripes is presented, suggesting how density waves, superconductivity, and strong correlations can compete with the quantum size effects inherent in narrow stripes. The anomalous doping dependence of the chemical potential is explained.
RESISTIVE UPPER CRITICAL FIELD OF SUPERCONDUCTING SPIN-LADDER Sr14-xCaxCu24O41
Authors: NAKANISHI T. , MOTOYAMA N. , MITAMURA H. , TAKESHITA N. , TAKAHASHI H. , EISAKI H. , UCHIDA S. , MÔRI N.
Published: July 2002

We report the resistive upper critical field Hc2(T) of the hole-doped two-leg ladder Sr 14-x Ca x Cu 24 O 41(x=12) single crystal, which becomes superconducting with Tc~5 K in a pressure range above ~3.0 GPa . Using a newly developed compact high-pressure cell, the magneto-transport measurements have been performed at temperatures down to ~140 mK under high pressure above 3.5 GPa. It is found that Hc2 (perpendicular to the ladder Cu 2 O 3 plane) increases anomalously as the temperature is decreased having an upward curvature and shows no saturation down to T/T c ~ 0.03. Also, its temperature dependence is found to resemble that of the high-Tc superconducting oxide Tl 2 Ba 2 CuO 6. This fact suggests that the anomalous behavior of Hc2 has a common origin between the ladders and the two-dimensional high-Tc superconducting oxides.
QUANTUM DOTS AND THE MANY-BODY PROBLEM
Authors: WEIDENMÜLLER H. A.
Published: July 2002

Quantum dots are often referred to as artificial atoms: Metallic gates at the surface of a GaAs-GaAlAs heterostructure confine the two-dimensional electron gas at the interface to an area of ≤μm2 size. Because of the tunneling barriers connecting the quantum dot to external leads, the number of electrons on the dot is (almost) integer, and the Coulomb interaction is important and affects many properties of quantum dots: The spacing of Coulomb blockade resonances, the co-tunneling between resonances, and (possible) localization in Fock space. Some theoretical work relating to these topics is reviewed.