bluuebunny/crossref_metadata_2025 huggingface dataset:
THE PREPARATION OF HIGHLY PURIFIED PR8 INFLUENZA VIRUS FROM INFECTED MOUSE LUNGS
Authors: Knight C. A.
Published: June 2004

Highly purified preparations of PR8 influenza virus were obtained from perfused, infected mouse lungs by a combination of methods involving adsorption of the virus on and elution from chicken red cells and differential centrifugation. Such preparations were found to possess 50 per cent infectivity end-points at 10–11 to 10–11.8, and 10–13 to 10–14.3 gm. of nitrogen in mice and in chick embryos, respectively. A sedimentation constant of 683 S was obtained for the material and electron micrographs revealed essentially spherical particles about 100 mµ in diameter. The material was isoelectric at pH 5.4 and chemical analyses on several of the preparations indicated the presence of 10.1 per cent of nitrogen, 1.06 per cent of phosphorus, 6.2 per cent of carbohydrate and about 33 per cent of lipid. Positive tests were obtained for both ribonucleic and desoxyribonucleic acids. The virus was precipitated strongly by antisenim to purified PR8 virus obtained from the allantoic fluid of infected chick embryos and this serum inhibited the agglutination of red cells by the mouse virus to a dilution of about 40,000.

In general, the properties of the virus isolated from infected mouse lungs were found to coincide with those of the virus obtained from the allantoic fluid of infected chick embryos.
Employment Densities, Spatial Autocorrelation, and Subcenters in Large Metropolitan Areas
Authors: McMillen Daniel P.
Published: June 2004

Employment density functions are estimated for 62 large metropolitan areas. Estimated gradients are statistically significant for distance from the nearest subcenter as well as for distance from the traditional central business district. Lagrange Multiplier (LM) tests imply significant spatial autocorrelation under highly restrictive ordinary least squares (OLS) specifications. The LM test statistics fall dramatically when the models are estimated using flexible parametric and nonparametric methods. The results serve as a warning that functional form misspecification causes spatial autocorrelation.
What's in a Name? Extracting Econometric Drivers to Assess The Impact of National Park Designation*
Authors: Weiler Stephan , Seidl Andrew
Published: June 2004

Public land designations are often primarily political decisions that may also have substantial local economic impacts. This paper econometrically estimates the visitation effect of the conversion of National Monuments to National Parks through the eight designation changes that have occurred between 1979 and 2000. The study finds robust and significant impacts of such conversions, yielding 11,642 additional visitors annually, even after controlling for likely site acreage expansion and other site visitation trends. Furthermore, these new visitors do not appear to occur at the expense of visitation at alternative sites. Using these findings, the paper explores the local economic impact of the Great Sand Dunes conversion on Colorado's San Luis Valley.
Regional Occupational Employment Projections: Modeling Supply Constraints in the Direct‐Requirements Approach*
Authors: Sweeney Stuart H.
Published: June 2004

Detailed industry‐occupation employment forecasts are an important class of regional labor market information produced by the U.S. Bureau of Labor Statistics. In theory, the forecasts should improve the national, interregional, and intertemporal matching efficiency of labor markets. But the efficiency argument is dependent on the quality of the forecasts. The methodology used to produce the projections is still fundamentally a demand‐requirements approach that implicitly assumes that labor supply is infinitely elastic for every occupation. This paper examines the validity of that assumption and evaluates a demographically based labor supply module as an adjunct to the current methodology.
A Life‐cycle Model of Locational Choice in a Two‐region Economy*
Authors: Althaus Paul G.
Published: June 2004

The ability to use the amenities or other characteristics of a location may be a function of the length of time a household has resided in the location. We explore the implications of the hypothesis that the enjoyment of regional amenities depends on the accumulation of amenity‐specific human capital. We establish that the interaction of this human capital with regional wage rates determines life‐cycle locational trajectories. The model explains the timing of moves in the working and retirement periods of life as well as observed heterogeneity in household behavior. Small differences between households may result in dramatically different life‐cycle behavior.
A chemical dataset for evaluation of alternative approaches to skin‐sensitization testing
Authors: Gerberick G. Frank , Ryan Cindy A. , Kern Petra S. , Dearman Rebecca J. , Kimber Ian , Patlewicz Grace Y. , Basketter David A.
Published: June 2004

Allergic contact dermatitis resulting from skin sensitization is a common occupational and environmental health problem. In recent years, the local lymph node assay (LLNA) has emerged as a practical option for assessing the skin‐sensitization potential of chemicals. In addition to accurate identification of skin sensitizers, the LLNA can also provide a reliable measure of relative sensitization potency, information that is pivotal in successful management of human health risks. However, even with the significant animal welfare benefits provided by the LLNA, there is interest still in the development of non‐animal test methods for skin sensitization. Here, we provide a dataset of chemicals that have been tested in the LLNA and the activity of which correspond with what is known of their potential to cause skin sensitization in humans. It is anticipated that this will be of value to other investigators in the evaluation and calibration of novel approaches to skin‐sensitization testing. The materials that comprise this dataset encompass both the chemical and biological diversity of known chemical allergens and provide also examples of negative controls. It is hoped that this dataset will accelerate the development, evaluation and eventual validation of new approaches to skin‐sensitization testing.
Oral prednisone suppresses allergic but not irritant patch test reactions in individuals hypersensitive to nickel
Authors: Anveden Ingegärd , Lindberg Magnus , Andersen Klaus E. , Bruze Magnus , Isaksson Marléne , Liden Carola , Sommerlund Mette , Wahlberg Jan E. , Wilkinson John D. , Willis Carolyn M.
Published: June 2004

A multicentre, randomized, double‐blind, crossover study was designed to investigate the effects of prednisone on allergic and irritant patch test reactions. 24 subjects with known allergy to nickel were recruited and patch tested with a nickel sulfate dilution series in aqueous solution, 5% nickel sulfate in petrolatum and 2 dilution series of the irritants nonanoic acid and sodium lauryl sulfate. The subjects were tested ×2, both during treatment with prednisone 20 mg oral daily and during placebo treatment. The total number of positive nickel patch test reactions decreased significantly in patients during prednisone treatment. The threshold concentration to elicit a patch test reaction increased and the overall degree of reactivity to nickel sulfate shifted towards weaker reactions. The effect of prednisone treatment on the response to irritants was divergent with both increased and decreased numbers of reactions, although there were no statistically significant differences compared with placebo. It is concluded that oral treatment with prednisone suppresses patch test reactivity to nickel, but not to the irritants tested.
The Nicaraguan Literacy Crusade Revisited: The Teaching of Literacy as a Nation–Building Project
Authors: Baracco Luciano
Published: June 2004

This article draws on the ideas of Anderson (1991) in discussing the role played by the National Literacy Crusade of 1980 in imagining the Nicaraguan nation. As the article demonstrates, the National Literacy Crusade had the potential to create a sense of communion with a mass of anonymous others that is, according to Anderson, the hallmark of modern nations. At the same time, it was also a project that sought to foster a particular national identity centred around the anti–imperialist and socialist nationalism of the Sandinista National Liberation Front.
Effects of tetracycline on the pharmacokinetics of halofantrine in healthy volunteers
Authors: Bassi Peter U. , Onyeji Cyprian O. , Ukponmwan Otas E.
Published: June 2004

Aims  To investigate the effect of tetracycline co‐administration on the pharmacokinetics of halofantrine in healthy subjects.

Methods  Eight healthy males were each given 500 mg single oral doses of halofantrine alone, or with tetracycline (500 mg 12 hourly for 7 days), in a crossover fashion. Blood samples collected at predetermined intervals were analyzed for halofantrine and its major metabolite, desbutylhalofantrine (HFM), using a validated HPLC method.

Results  Co‐administration of tetracycline and halofantrine resulted in a significant increase (P < 0.05) in the maximum plasma concentration (Cmax), total area under the concentration‐time curve (AUC), and terminal elimination half‐life (t1/2,z), compared with halofantrine alone. (Cmax 0.43 ± 0.14 vs 1.06 ± 0.44 µg ml−1 (95% CI on the difference 0.30, 0.95); AUC 32.0 ± 13.6 vs 63.7 ± 20.1 µg ml−1 h (95% CI 14.2, 49.1); t1/2,z: 90.8 ± 17.9 vs 157.4 ± 57.4 h (95% CI 21.7, 111.5)). Similarly, tetracycline caused a significant increase (P < 0.05) in the AUC and Cmax of HFM.

Conclusions  Tetracycline co‐administration significantly increases the plasma concentrations of halofantrine and its major metabolite.
Pharmacokinetics of fosfluconazole and fluconazole following multiple intravenous administration of fosfluconazole in healthy male volunteers
Authors: Sobue Satoshi , Tan Keith , Layton Gary , Eve Malcolm , Sanderson J. Brian
Published: June 2004

Aims

To assess the bioavailability of fluconazole (FLCZ) from phosphate pro‐drug (fosfluconazole), to investigate the effect of loading doses on the time to achieve FLCZ steady state plasma concentrations and on safety, and to investigate the pharmacokinetics of fosfluconazole following once daily multiple bolus injection of fosfluconazole in healthy male volunteers.

Methods

The first study was a randomized, double‐blind, double dummy, two‐period crossover study. Subject received either 1000 mg fosfluconazole or 800 mg FLCZ once daily for 14 days in random order. The second study was an open label, randomized parallel group study. Subjects received one of three fosfluconazole once daily treatments: 500 mg for 10 days (no loading dose), a loading dose of 1000 mg on day 1 followed by 500 mg for 9 days (one loading dose), or loading doses of 1000 mg on days 1 and 2 followed by 500 mg for 8 days (two loading doses).

Results

The estimated mean (90% CI) bioavailability of FLCZ from fosfluconazole was 96.8% (94.5, 99.2), with a Cmax,ss ratio of 98.3% (93.3, 103.5) in the first study. Less than 1% of the administered dose of fosfluconazole was excreted unchanged in the urine and the majority (85.6%) was eliminated in the urine as FLCZ. In the second study two loading doses regimen led to earlier achievement of target steady state plasma concentrations (by day 3) compared with use of one or no loading dose (towards the end of the dosing period). Similar adverse event profiles were seen in all three treatment groups. Fosfluconazole did not accumulate after multiple dosing.

Conclusions

Multiple administration of 1000 mg fosfluconazole and 800 mg FLCZ produced equivalent systemic exposure to FLCZ. Steady state FLCZ plasma concentrations were achieved earliest when two loading doses were used.
Single and short‐term dosing effects of levocetirizine on adenosine monophosphate bronchoprovocation in atopic asthma
Authors: Lee Daniel K. C. , Gray Robert D. , Wilson Andrew M. , Robb Fiona M. , Soutar Patricia C. , Lipworth Brian J.
Published: June 2004

Aims  Adenosine monophosphate (AMP) acts indirectly via primed airway mast cells to induce bronchial hyper‐responsiveness, which in turn correlates with eosinophilic asthmatic  inflammation  and  atopic  disease  expression.  We  evaluated  single and short‐term dosing effects of a modern histamine H1‐receptor antagonist, levocetirizine, given at the usual clinically recommended dose, on the primary outcome of AMP bronchoprovocation.

Methods  Fifteen atopic asthmatics were randomized in double‐blind, cross‐over fashion to receive for 1 week either levocetirizine 5 mg or placebo. There was a 1‐week washout period prior to each randomized treatment. The provocative concentration of AMP producing a 20% fall in FEV1 (PC20) was measured after each washout at baseline and at 4–6 h following the first and last doses of each randomized treatment.

Results  Baseline mean ± SEM values after washout prior to each randomized treatment comparing levocetirizine vs placebo were not significantly different for prechallenge FEV1 (% predicted) 83 ± 4 vs 82 ± 4, or AMP PC20 (mg ml−1) 45 ± 24 vs 45 ± 22, respectively. Airway calibre as prechallenge FEV1 for levocetirizine vs placebo was not significantly different following the first dose 86 ± 4 vs 82 ± 4, or the last dose 85 ± 4 vs 83 ± 4, respectively. There were significant improvements (P < 0.05) in AMP PC20 comparing levocetirizine vs placebo following the first dose 123 ± 73 vs 48 ± 24, a 1.4 doubling dilution difference (95% CI 0.8, 1.9), and the last dose 127 ± 74 vs 53 ± 29, a 1.2 doubling dilution difference (95% CI 0.5, 2.0). AMP PC20 was also improved (P < 0.05) by the first and last doses of levocetirizine but not placebo, vs respective baseline values, with there being no difference in the degree of protection between first and last doses.

Conclusions  Single and short‐term dosing with levocetirizine conferred similar improvements in bronchial hyper‐responsiveness to AMP challenge, which was unrelated to prechallenge airway calibre. Further studies are indicated to evaluate the longer‐term effects of levocetirizine on asthma exacerbations.
Enzymes in organic media
Authors: Gupta Munishwar N. , Roy Ipsita
Published: June 2004

Enzyme catalysis in low water containing organic solvents is finding an increasing number of applications in diverse areas. This review focuses on some aspects which have not been reviewed elsewhere. Different strategies for obtaining higher activity and stability in such media are described. In this context, the damaging role of lyophilization and the means of overcoming such effects are discussed. Ultrasonication and microwave assistance are two emerging approaches for enhancing reaction rates in low water media. Control of water activity and medium engineering are two crucial approaches in optimization of catalytic behaviour in nonaqueous enzymology. Organometallics and synthesis/modification of polymers are two areas where nonaqueous enzymology can play a greater role in the coming years. The greater understanding of enzyme behaviour in nonaqueous media is expected to lead to larger and even more diverse kinds of applications.
Role of peroxidase inhibition by insulin in the bovine thyroid cell proliferation mechanism
Authors: Krawiec León , Pizarro Ramón A , Aphalo Paula , de Cavanagh Elena M. V. , Pisarev Mario A. , Juvenal Guillermo J. , Policastro Lucía , Bocanera Laura V.
Published: June 2004

Monolayer primary cultures of thyroid cells produce, in the presence of insulin, a cytosolic inhibitor of thyroid peroxidase (TPO), lacto peroxidase (LPO), horseradish peroxidase (HRPO) and glutathione peroxidase (GPX). The inhibitor, localized in the cytosol, is thermostable and hydrophylic. Its molecular mass is less than 2 kDa. The inhibitory activity, resistant to proteolytic and nucleolytic enzymes, disappears with sodium metaperiodate treatment, as an oxidant of carbohydrates, supporting its oligosaccharide structure. The presence of inositol, mannose, glucose, the specific inhibition of cyclic AMP‐dependent protein kinase and the disappearance of peroxidase inhibition by alkaline phosphatase and α‐mannosidase in purified samples confirms its chemical structure as inositol phosphoglycan‐like. Purification by anionic interchange shows that the peroxidase inhibitor elutes like the two subtypes of inositol phosphoglycans (IPG)P and A, characterized as signal transducers of insulin action. Insulin significantly increases the concentration of the peroxidase inhibitor in a thyroid cell culture at 48 h. The addition of both isolated substances to a primary thyroid culture produces, after 30 min, a significant increase in hydrogen peroxide (H2O2) concentration in the medium, concomitantly with the disappearance of the GPX activity in the same conditions. The presence of insulin or anyone of both products, during 48 h, induces cell proliferation of the thyroid cell culture. In conclusion, insulin stimulates thyroid cell division through the effect of a peroxidase inhibitor, as its second messenger. The inhibition of GPX by its action positively modulates the H2O2 level, which would produce, as was demonstrated by other authors, the signal for cell proliferation.
The crystal structure of the tryptophan synthase β2 subunit from the hyperthermophile Pyrococcus furiosus
Authors: Hioki Yusaku , Ogasahara Kyoko , Lee Soo Jae , Ma Jichun , Ishida Masami , Yamagata Yuriko , Matsuura Yoshiki , Ota Motonori , Ikeguchi Mitsunori , Kuramitsu Seiki , Yutani Katsuhide
Published: June 2004

The structure of the tryptophan synthase β2 subunit (Pfβ2) from the hyperthermophile, Pyrococcus furiosus, was determined by X‐ray crystallographic analysis at 2.2 Å resolution, and its stability was examined by DSC. This is the first report of the X‐ray structure of the tryptophan synthase β2 subunit alone, although the structure of the tryptophan synthase α2β2 complex from Salmonella typhimurium has already been reported. The structure of Pfβ2 was essentially similar to that of the β2 subunit (Stβ2) in the α2β2 complex from S. typhimurium. The sequence alignment with secondary structures of Pfβ and Stβ in monomeric form showed that six residues in the N‐terminal region and three residues in the C‐terminal region were deleted in Pfβ, and one residue at Pro366 of Stβ and at Ile63 of Pfβ was inserted. The denaturation temperature of Pfβ2 was higher by 35 °C than the reported values from mesophiles at ≈ pH 8. On the basis of structural information on both proteins, the analyses of the contributions of each stabilization factor indicate that: (a) the higher stability of Pfβ2 is not caused by either a hydrophobic interaction or an increase in ion pairs; (b) the number of hydrogen bonds involved in the main chains of Pfβ is greater by about 10% than that of Stβ, indicating that the secondary structures of Pfβ are more stabilized than those of Stβ and (c) the sequence of Pfβ seems to be better fitted to an ideally stable structure than that of Stβ, as assessed from X‐ray structure data.
Modulation of sarcoplasmic reticulum Ca2+‐ATPase by chronic and acute exposure to peroxynitrite
Authors: Gutiérrez‐Martín Yolanda , Martín‐Romero Francisco J. , Iñesta‐Vaquera Francisco A. , Gutiérrez‐Merino Carlos , Henao Fernando
Published: June 2004

The Ca2+‐ATPase of skeletal muscle sarcoplasmic reticulum (SERCA), an integral membrane protein, becomes irreversibly inactivated in vitro by the addition of a single bolus of peroxynitrite with a K0.5 of 200–300 µm, and this results in a large decrease of the ATP‐dependent Ca2+ gradient across the sarcoplasmic reticulum (SR) membranes. The inactivation of SERCA is raised by treatment of SR vesicles with repetitive micromolar pulses of peroxynitrite. The inhibition of the SERCA is due to the oxidation of thiol groups and tyrosine nitration. Scavengers that react directly with peroxynitrite, such as cysteine, reduced glutathione, NADH, methionine, ascorbate or Trolox, a water‐soluble analog of α‐tocopherol, afforded significant protection. However, dimethyl sulfoxide and mannitol, two hydroxyl radical scavengers, and α‐tocopherol did not protect SERCA from inactivation. Our results showed that the target of peroxynitrite is the cytosolic globular domain of the SERCA and that major skeletal muscle intracellular reductants (ascorbate, NADH and reduced glutathione) protected against inhibition of this ATPase by peroxynitrite.
Role of K22 and R120 in the covalent binding of the antibiotic fosfomycin and the substrate‐induced conformational change in UDP‐N‐acetylglucosamine enolpyruvyl transferase
Authors: Thomas Alison M. , Ginj Cristian , Jelesarov Ilian , Amrhein Nikolaus , Macheroux Peter
Published: June 2004

UDP‐N‐acetylglucosamine enolpyruvyl transferase (MurA), catalyzes the first step in the biosynthesis of peptidoglycan, involving the transfer of the intact enolpyruvyl moiety from phosphoenolpyruvate to the 3′‐hydroxyl group of UDP‐N‐acetylglucosamine (UDPNAG). The enzyme is irreversibly inhibited by the antibiotic fosfomycin. The inactivation is caused by alkylation of a highly conserved cysteine residue (C115) that participates in the binding of phosphoenolpyruvate. The three‐dimensional structure of the enzyme suggests that two residues may play a decisive role in fosfomycin binding: K22 and R120. To investigate the role of these residues, we have generated the K22V, K22E, K22R and R120K single mutant proteins as well as the K22V/R120K and K22V/R120V double mutant proteins. We demonstrated that the K22R mutant protein behaves similarly to wild‐type enzyme, whereas the K22E mutant protein failed to form the covalent adduct. On the other hand, the K22V mutant protein requires the presence of UDPNAG for the formation of the adduct indicating that UDPNAG plays a crucial role in the organization of productive interactions in the active site. This model receives strong support from heat capacity changes observed for the K22V/R120K and R120K mutant proteins: in both mutant proteins, the heat capacity changes are markedly reduced indicating that their ability to form a closed protein conformation is impeded due to the R120K exchange.
The crystal structure of glucose‐6‐phosphate isomerase from Leishmania mexicana reveals novel active site features
Authors: Cordeiro Artur T. , Michels Paul A. M. , Delboni Luiz F. , Thiemann Otávio H.
Published: June 2004

Glucose‐6‐phosphate isomerase catalyzes the reversible aldose‐ketose isomerization of d‐glucose‐6‐phosphate to d‐fructose‐6‐phosphate in glycolysis and gluconeogenesis, and in the recycling of hexose‐6‐phosphate in the pentose phosphate pathway. The unicellular protozoans, Trypanosoma brucei, T. cruzi and Leishmania spp., of the order Kinetoplastida are important human parasites responsible for African sleeping sickness, Chagas' disease and leishmaniases, respectively. In these parasites, glycolysis is an important (and in some cases the only) metabolic pathway for ATP supply. The first seven of the 10 enzymes that participate in glycolysis, as well as an important fraction of the enzymes of the pentose phosphate pathway, are compartmentalized in peroxisome‐like organelles called glycosomes. The dependence of the parasites on glycolysis, the importance of the pentose phosphate pathway in defense against oxidative stress, and the unique compartmentalization of these pathways, point to the enzymes contained in the glycosome as potential targets for drug design. The present report describes the first crystallographic structure of a parasite (Leishmania mexicana) glucose‐6‐phosphate isomerase. A comparison of the atomic structure of L. mexicana, human and other mammalian PGIs, which highlights unique features of the parasite's enzyme, is presented.
The in vitro effects of CRE‐decoy oligonucleotides in combination with conventional chemotherapy in colorectal cancer cell lines
Authors: Liu Wai M. , Scott Katherine A. , Shahin Sipra , Propper David J.
Published: June 2004

The cAMP response element consensus sequence directs the transcription of a wide range of genes. A 24‐mer single‐stranded cAMP response element decoy oligonucleotide (CDO) has been shown to compete with these sequences for binding transcription factors and therefore interferes with cAMP‐induced gene transcription. We have examined the effect of this CDO alone and in combination with a range of common chemotherapeutic agents in colorectal cancer cell lines. CDO had a potent anti‐proliferative effect in colorectal cell lines, yet, a similar enhancement of cell death was not observed. Simple drug–drug interaction studies showed that combining CDO with chemotherapy resulted in an enhancement of the antiproliferative effects. Furthermore, this cytostatic effect was protracted and associated with an increase in senescence‐associated β‐galactosidase activity at pH 6. There is a possible role for p21waf1 in mediating this effect, as the enhancement of cell growth inhibition was not observed in cells lacking the ability to correctly upregulate this protein. Additionally, significant decreases in cyclin‐dependent kinase (CDK) 1 and CDK 4 function were seen in the responsive cells. These data provide a possible model of drug interaction in colorectal cell lines, which involves the complex interplay of the molecules regulating the cell cycle. Clinically, the cytostatic ability of CDO could improve and enhance the antiproliferative effects of conventional cytotoxic agents.
Mutational analysis of methionine adenosyltransferase from Leishmania donovani
Authors: Pérez‐Pertejo Yolanda , Reguera Rosa M. , García‐Estrada Carlos , Balaña‐Fouce Rafael , Ordóñez David
Published: June 2004

The methionine adenosyltransferase (MAT; EC 2.5.1.6) mediated synthesis of S‐adenosylmethionine (AdoMet) is a two‐step process, consisting of the formation of AdoMet and the subsequent cleavage of the tripolyphosphate (PPPi) molecule, a reaction induced, in turn, by AdoMet. The fact that the two activities − AdoMet synthesis and tripolyphosphate hydrolysis − can be measured separately is particularly useful when the site‐directed mutagenesis approach is used to determine the functional role of the amino acid residues involved in each. This report describes the mutational analysis of the amino acids involved in both the ATP and l‐methionine binding sites of Leishmania donovani MAT (GenBank accession number AF179714) the aetiological agent of visceral leishmaniasis. Site‐directed mutagenesis was used to substitute neutral residues for the basic amino acid (Lys168, Lys256, Lys276, Lys280 and His17), acidic residues (Asp19, Asp121, Asp166, Asp249, Asp277 and Asp288) and Phe241 involved in AdoMet synthesis and PPPi hydrolysis. With the exception of D116N, none of these mutants was able to synthesize AdoMet at a significant rate, although H17A, H17N, K256A, K280A, D19N, D121N, D166N, D249N and D282N showed measurable tripolyphosphatase activity. Finally, the C‐terminus domain of L. donovani MAT was truncated at three points (F382Stop, D375Stop, F368Stop), deleting a 310 one‐turn helix motif in all three cases. Whilst none of the truncated proteins conserved MAT activity, they were able to hydrolyse PPPi, albeit at a lower rate than the wild‐type enzyme. A fourth protein with an internal deletion (E376ΔF382) in the C‐terminal domain conserved high tripolyphosphatase activity, which was not, however, induced by 50 µm AdoMet.
Tumour necrosis factor‐α stimulates expression of TNF‐α converting enzyme in endothelial cells
Authors: Bzowska Monika , Jura Natalia , Lassak Adam , Black Roy A. , Bereta Joanna
Published: June 2004

Tumor necrosis factor‐α converting enzyme (ADAM17) is a major metalloproteinase involved in the shedding of several membrane‐bound cytokines and cytokine receptors. Interplay of cytokines and their soluble receptors might be an important regulatory element in the network of interactions responsible for maintaining homeostasis in the immune system. ADAM17 thus has the potential to participate in a broad range of immune reactions. We studied the mechanisms of ADAM17 activation in endothelial cells and found that pro‐inflammatory cytokines (tumor necrosis factor‐α, interleukin‐1β, interferon‐γ) and growth factors (epidermal growth factor, vascular endothelial growth factor) are able to upregulate transcription of ADAM17 and expression of ADAM17 protein. This process might constitute an important mechanism of regulation of ADAM17 activity. Stimulation of transcription, rather than increased ADAM17 mRNA stability, was responsible for increased levels of ADAM17 mRNA. Importantly, the increase in ADAM17 was accompanied by increased shedding of TNF‐Receptor I (p55) in tumor necrosis factor‐α‐stimulated endothelial cells. Therefore, ADAM17‐dependent depletion of membrane‐bound tumor necrosis factor receptors from endothelial cells might constitute a mechanism of self‐protection in states of prolonged immunostimulation.
Native and introduced fish species richness in French lakes: local and regional influences
Authors: Irz Pascal , Argillier Christine , Oberdorff Thierry
Published: June 2004

Aim  To analyse the importance of local and regional influences on the patterns of species richness in natural and man‐made lakes and to infer the impacts of human‐mediated introductions on these patterns.

Location  France.

Methods  Species occurrence data were gathered for 25 natural and 51 man‐made lakes. Analysis is based on regression models of local richness against their related regional richness and lake environmental variables.

Results  Local native richness was mostly controlled by the regional richness. Conversely, local total richness was mainly explained by local variables. These statements apply to both natural and man‐made lakes. Lacustrine systems displayed weak resistance to invaders.

Main conclusions  Species introductions have apparently contributed to saturate fish communities in these systems even if no clear negative effect on the survival of native species (i.e. species extinction) is detectable so far.
Sovereignty, Migration and the Rule of Law in Global Times
Authors: Dauvergne Catherine
Published: June 2004

This article argues that in the present era of globalisation, control over the movement of people has become the last bastion of sovereignty. This is important both to theoretical accounts of globalisation and to policy decisions by governments. Nation states threatened with loss of control in other realms are implementing a variety of ‘crackdown’ measures in questions of immigration. Issues of refugee law, illegal migration and skilled migration each challenge sovereignty in specific ways. While international human rights standards have made few inroads in questions of migration, recent decisions in England and Australia suggest that the rule of law may be emerging as a counter to traditional executive free reign in matters of migration law.
Are the underprivileged really that economically ‘leftist’? Attitudes towards economic redistribution and the welfare state in Flanders
Authors: DERKS ANTON
Published: June 2004

Abstract.  According to S. M. Lipset, the working classes are authoritarian in the cultural domain, but leftist in the economic domain as the interests of the underprivileged make them inclined to support redistributive politics. These findings have been repeated in an extensive body of research. In our analysis using Flemish (Belgian) data (N =1,577), we examine the economic orientations of the underprivileged, more specifically their attitudes towards social inequality, economic redistribution and welfare state politics. We found that many respondents (especially among the underprivileged) express complaints against social inequality, while at the same time rejecting the arrangements of the welfare state. We argue that it is inappropriate to consider this economic orientation as a specific ideological doctrine. Rather it should be considered as a syndrome that can be labelled ‘economic populism’. Economic populism is caused by feelings of social discontent, such as defeatism and political distrust. The methodological and theoretical implications of these findings will be discussed.
How multilevel structures affect environmental policy in industrialized countries
Authors: WÄLTI SONJA
Published: June 2004

Abstract.  Extensive decentralization and devolution efforts among industrialized nations throughout the 1980s and 1990s call for a closer look at the effect these trends have on public policy. This article investigates the impact of these trends on the environmental performance of industrialized countries. There are two competing hypotheses as to how federalism and other multilevel governance structures affect the environmental performance of countries. The first stresses that the resulting institutional fragmentation and regulatory unpredictability is detrimental to the protection of the environment. An alternative hypothesis emphasizes that multilevel systems fare better regarding environmental performance because they can effectively respond to local needs and encourage innovation at the sub‐national level. Based on OECD air pollution data, the study finds that multilevel structures affect the way in which important determinants of environmental performance work. Thus, corporatist accommodation structures, which are known to enhance environmental policy, do so primarily in multi‐tiered systems. A high level of economic development, on the other hand, which has also been shown to contribute to environmental performance, does so mainly in countries that are characterized by weak multilevel structures. The article discusses theoretical and practical implications of these findings.
The consequences of delegation to independent agencies: Separation of powers, discursive governance and the regulation of telecommunications in Germany
Authors: GEHRING THOMAS
Published: June 2004

Abstract.  Whereas the delegation of regulatory powers is usually examined from the principal's perspective, this article explores the consequences of delegation for the regulatory output. Empirically, it finds that the dissolution of the original German postal authority led to the establishment of a system of divided labour in which different actors, including an (almost) independent regulatory agency, depend on each other's performance of specialized functions. Theoretically, it contributes to the ongoing debate over the role and operation of independent agencies in two main respects. First, based on the modern theory of social systems, it draws attention to the fact that the reform process was characterized by an increased functional differentiation of institutionalized decision‐making. Second, drawing on the Habermasian theory of communicative action, it is argued that functional differentiation supports the transformation of interaction from interest‐based bargaining to deliberative arguing both in the legislative and the administrative arenas. As political actors are made unable to resort to their power resources, reasons become a key source of influence.
Complications in Large‐bore Catheters for Extracorporeal Detoxification Methods
Authors: Bambauer Rolf , Latza Reinhard
Published: June 2004

Abstract:  Catheters for large vessels have become essential tools for the management of hospitalized or chronically ill patients requiring intensive medical treatments such as extracorporeal detoxification procedures. The increased use of such devices has been accompanied by a corresponding increase in complications, such as infection, sepsis, and thrombosis. In two retrospective studies, the first (1979–1990) with 1672 patients and 2626 large‐bore catheters and the second (1996–2001) with 182 patients and 332 acute catheters, the frequency of infections, thrombosis, bleeding, and other side‐effects were investigated. All complications and side‐effects are presented. In total, the complication rate was in the first study 27.7% (internal jugular vein 23.8% in 2105 catheters, subclavian vein 43.5% in 521 catheters) and in the second study 32.2% (internal jugular vein 20% in 231 catheters, subclavian vein 60.6% in 94 catheters, femoral vein 57.1% in 7 catheters). The majority of complications were puncture not possible, puncture of the artery abscess, septicemia, bleeding, thrombosis, and faults in catheter material. To minimize these complication rates the handling of the inserted catheters before, during, and after the hemodialysis or apheresis treatment is minimized.
Unisothermal Control of the Cascade of CSTR Using Constant Degree of Thermal Stability
Authors: Horák Josef , Rosol Petr
Published: June 2004

Unisothermal control of a cascade of continuous stirred tank reactors was analyzed. The control strategy is based on keeping the same degree of the thermal stability for all reactors in the cascade. The cooling driving force (the stationary temperature difference between the reaction mixture and the coolant) was used as the measure of the thermal regime stability. The structure of possible steady states was established, the thermal stability and technological properties of steady states were discussed. The most advantageous set of stationary states is recommended and the possibility of practical application of the suggested control strategy was discussed.
Photooxidation of Cyclohexane with Dioxygen in Acetonitrile in the Presence of Transition Metal Chlorides
Authors: Lederer Pavel , Nizova Galina V. , Kats Marina M. , Shuľpin Georgii B.
Published: June 2004

Irradiation of cyclohexane solution in acetonitrile (λ = 300, 365, or 436 nm) in the presence of dioxygen and catalytic amounts of FeCl3, CuCl3, Na[AuCl4] or H2[PtCl]6 gives rise to cyclohexanol and cyclohexanone (after GLC). The quantum yields with respect to the products lie within the range of 0.01 to 0.05. The most efficient of the catalysts used is FeCl3, and the most efficient radiation wavelength is λ = 365 nm. A reaction pathway is suggested; it is assumed that the first step is photoexcitation of M-Cl followed by electron transfer from the ligand to the metal associated with the formation of the Cl. radical, which reacts (probably after solvation by the solvent) with RH giving R.. The Fe(II) species is oxidized by ROO., and the photocatalytically active complex is restored. Complexes with metals in low oxidation states (particularly in the case of Cu, Au and Pt), however, can react with molecular oxygen to give peroxo or oxo complexes, which can directly hydroxylate alkanes.
Substituent Effects on the Basicity of ortho-, meta- and para-substituted N1,N1-Dimethyl-N2-phenylformamidines in Ethanol and in Water
Authors: Raczyńska Ewa Daniela
Published: June 2004

The relative δpKa values of ortho-, meta-, and para-substituted N1,N1-dimethyl-N2-phenylformamidines obtained in 95.6% aqueous ethanol have been compared with those in water. The comparison shows only some differences in the ortho substituent effects. The meta and para substituent effects in ethanol are not very different from those in water. Quantitative analysis of the experimental δpKa values based on the Taft equation has led to separation of the total electromeric effects into the inductive and mesomeric effects. As compared to the amino group in anilines, the formamidine group is more sensitive to the transmission of the inductive than the mesomeric effects.
Total Synthesis of Protected Form of Fungi Metabolite Cortalcerone
Authors: Szechner Barbara , Achmatowicz Osman
Published: June 2004

Synthesis of methyl 4,5-dideoxy-D,L-hex-4-enos-2-ulopyranosid-3-ulose ethylene acetal, derivative of the first natural sugar with dihydropyranone moiety, from 5-acetoxymethylfurfural is described. It was shown that 1,3-transposition of the allylic alcohol in the dihydropyran ring, a key step of the synthesis, can be carried out via an intermediate allylic selenoxide with excellent regio- and stereoselectivity.
Synthesis and Calcium Antagonist Activity of Dialkyl 1,4-Dihydro-2,6-dimethyl-4-(nitrogenous heteroaryl)-3,5-pyridine Dicarboxylates
Authors: Baraldi Pier G. , Budriesi Roberta , Cacciari Barbara , Chiarini Alberto , Garuti Laura , Giovanninetti Giuseppe , Leoni Alberto , Roberti Marinella
Published: June 2004

A new series of 4-(nitrogenous heteroaryl)-1,4-dihydropyridine antagonists II - XVI were synthesized and screened for inotropic, chronotropic and calcium antagonist properties, in order to evaluate the effect on pharmacological activity of replacement of the 4-aryl group of nifedipine-like drugs by heterocyclic moieties, such as quinoline, indole, carbazole and pyrazole. The most potent bradycardic compounds of the series (VIII - X, XII and XIII) elicited weak calcium antagonist activity and were stronger negative inotropic.
Synthesis and Antibacterial Activity of Some 3-Hydroxyquinolones
Authors: Rádl Stanislav , Janichová Magda
Published: June 2004

A reductive decarboxylation of 7-chloro-1-ethyl-6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid (Id) with sodium borohydride provided the respective 1,2,3,4-tetrahydro derivative Va, which was treated with selenium dioxide to give product of dehydrogenation VIa. 3-Acetyl-1-ethyl-1,4-dihydroquinolin-4-ones VIb and VIc were oxidized with 3-chloroperoxybenzoic acid to the respective 3-hydroxyderivatives IIIa and IIIb. Compound IIIb was benzylated on a hydroxy group at position 3 to corresponding 3-benzyloxy derivative VIf which after prolonged heating with N-methylpiperazine in a sealed tube provided directly 3-hydroxy-7-(4-methyl-1-piperazinyl) derivative IIIc.
Conjugates of Hepatitis B Surface Antigen (14-32)Pre-S2 Region with N-Acetylmuramic Acid, N-Acetylnormuramic Acid, and Their L-Alanyl-D-Isoglutamine Derivatives: Synthesis and Studies on Immunogenicity
Authors: Maćkiewicz Zbigniev , Świderska Hanna , Kalmanowa Maria , Smiatacz Zygfryd , Nowosławski Adam , Kupryszewski Gotfryd
Published: June 2004

Four novel analogs of hepatitis B virus surface antigen (14-32)Pre-S2 region fragment attached covalently to N-acetylmuramic acid, N-acetylmuramyl-L-alanyl-D-isoglutamine, N-acetylnormuramic acid, and N-acetylnormuramyl-L-alanyl-D-isoglutamine were synthesized by the solid phase method. The ability of analogs to induce cellular and humoral immunity to native HBsAg was tested on rabbits. Cellular immune response occurred in vitro, and HBs antibodies were detected in all immunized animals. No additional adjuvants were used in the tests.
Dissociation Time of Chemical Bond I. Dissociation of the Morse Oscillator
Authors: Valko Ladislav
Published: June 2004

By solving the equation of motion, the formula was derived for the dissociation time of the Morse oscillator. The dissociation time of oscillator is a characteristic physical parameter of chemical bond whose value depends on the parameters of potential curve. It is important for the selective excitation of chemical bond in a molecule in connection with the progress in femtosecond laser technique. The time required to break the bond must be of the order of a few hundred femtoseconds.
The Effect of Cluster Size on the Characteristics of Chemisorption in the Model Growth of Silicon Crystals
Authors: Burda Jaroslav , Bureš Michal , Černý Čestmír
Published: June 2004

The optimum cluster model size for the simulation of silicon crystal growth was sought by using the semiempirical CNDO/2 method. The Si4H9 system emerged as a reasonable compromise between the convergence of results and computation demands.
Activity Ratios of Lyate Ions in the Water-Alcohol Mixtures
Authors: Pavelek Zdeněk , Mollin Jiří
Published: June 2004

A new method for calculating the activity ratio of lyate ions in the water-alcohol mixtures is proposed on the basis of utilizing the linear relations between the Gibbs energies of ion transfer. The results for the water-methanol, -ethanol, and -2-propanol systems are compared with literature data. At the same time, the individual ionic products of water and alcohol in their mixtures were calculated. The accuracy of the method depends on the accuracy of experimental determination of the Gibbs energies of electrolyte transfer and of ionic products in mixed solvents.
Polarographic and Cyclic Voltammetric Behaviour of Some Azo Compounds Derived from Sulfonamide in DMF-Aqueous Solutions
Authors: Mabrouk El-Sayed M. , Killa Hamada M. , Abdel Fattah Abdel Fattah A. , Yasen Shalaby A.
Published: June 2004

The polarographic and cyclic voltammetric behaviour of (2-hydroxyphenylazo)-4-benzenesulfonamide and some of its derivatives have been studied in Britton-Robinson buffer series containing 30 vol.% of DMF. Over the entire pH range (2-12), the reduction pathway occurs through an irreversible 4-electron step corresponding to the reduction of N=N center to the amine stage. The voltammograms recorded in acidic and alkaline solution at different scan rates exhibit one or two cathodic peaks depending on the substituent and the pH of the medium. The electrode reaction mechanism was suggested, also the kinetic parameters were calculated.
Extraction of Alkali Metal and Ammonium Dipicrylaminates into Nitrobenzene in the Presence of Some Acyclic Polyethers
Authors: Makrlík Emanuel , Hálová Jaroslava , Vaňura Petr
Published: June 2004

The effect of the presence of six different acyclic polyethers (2-glym, 3-glym, 4-glym, PEG 200, PEG 300 and PEG 400), denoted by L, on the distribution of alkali metal dipicrylaminates and ammonium dipicrylaminate (MA) between the aqueous and nitrobenzene phases has been studied. The two-phase system can be quantitatively described by the following five chemical equilibria: Ma+ + Aa- + L0 ↔ MLa+ + Aa-,Ma+ + Aa- ↔ M0+ + A0-, MLA0 ↔ ML0+ + A0-, MA0 ↔ M0+ + A0-, La ↔ L0, for which the respective equilibrium constants Kex(ML+, A-), Kex(M+, A-), Kd0(MLA), Kd0(MA) and KD were determined. The values of Kex(ML+,A-) increase with the increasing crystallographic radius of the M+ ion and with the number of oxyethylene units in the molecule of the ligand, L, in the series 2-glym < 3-glym < 4-glym < PEG 200 < PEG 300 < PEG 400. In addition, it has been demonstrated that the stability of the ML0+ species in the nitrobenzene phase has a maximum value for M+ = Na+ for all the studied ligands. The presence of the polyethers is detrimental to the separation of Cs+ from the other cations, but improves the separation of Na+ from Li+. The extraction selectivities for the K+/NH4+, K+/Li+ and NH4+/Li+ pairs was not significantly affected by the presence of the ligands, except for 2-glym.
Kinetics and Mechanism of Oxidation of Tin(II) by Hexachloroiridate(IV) in Aqueous Perchlorate Solutions
Authors: Hassan Refat M.
Published: June 2004

The kinetics of hexachloroiridate(IV) oxidation of tin(II) in aqueous perchlorate media at a constant ionic strength of 2.0 mol dm-3 have been studied spectrophotometrically. The reaction was found to follow second-order overall kinetics and first order with respect to each of the reactants. The results showed hydrogen ion dependence where the reaction rate increased with increasing hydrogen ion concentration. The activation parameters were evaluated and a tentative reaction mechanism has been discussed.
A Comparative Study on Thin Poly-N-methylpyrrole and Polypyrrole Films
Authors: Novák Petr , Vielstich Wolf
Published: June 2004

Growth, cycling, and overoxidation of thin poly-N-methylpyrrole (PMePy) films was studied in 0.5 M LiClO4-propylene carbonate electrolyte. N-methylpyrrole starts to polymerize at about 3.53 V vs Li/Li+. The redox potential of PMePy is about 0.6 V more positive than that of polypyrrole (PPy). The overoxidation thresholds of both PMePy and PPy are, however, almost identical (3.8-3.9 V vs Li/Li+). Low doping levels, of the order of y ≈ 25%, are therefore reached during the nearly reversible potentiodynamic cycling of PMePy in the 2.0-4.0 V range, in contrast to y ≈ 42% attainable on polypyrrole (PPy) under the same conditions. Continuous slight decrease of the coulombic capacity of the polymer with the cycle number, attributed to an irreversible overoxidation, is observed. Addition of 1 vol% of water into the growth electrolyte does not improve the doping level of the PMePy film. Due to the poor electrochemical performance of thin PMePy films with respect to battery application, higher energy densities as offered from the Li/PPy system are not to be expected.