A fast magnetic vector characterization method for quasi two-dimensional systems and heterostructures

The use of magnetic vector tomography/laminography has opened a 3D experimental window to access the magnetization at the nanoscale. These methods exploit the dependence of the magnetic contrast in transmission to recover its 3D configuration. However, hundreds of different angular projections are required leading to large measurement times. Here we present a fast method to dramatically reduce the experiment time specific for quasi two-dimensional magnetic systems. The algorithm uses the Beer-Lambert equation in the framework of X-ray transmission microscopy to obtain the 3D magnetic configuration of the sample. It has been demonstrated in permalloy microstructures, reconstructing the magnetization vector field with a reduced number of angular projections obtaining quantitative results. The throughput of the methodology is × 10-× 100 times faster than conventional magnetic vector tomography, making this characterization method of general interest for the community.

Wine yeast selection in the Iberian Peninsula: Saccharomyces and non-Saccharomyces as drivers of innovation in Spanish and Portuguese wine industries

Yeast selection for the wine industry in Spain started in 1950 for the understanding of the microbial ecology, and for the selection of optimal strains to improve the performance of alcoholic fermentation and the overall wine quality. This process has been strongly developed over the last 30 years, firstly on Saccharomyces cerevisiae, and, lately, with intense activity on non-Saccharomyces. Several thousand yeast strains have been isolated, identified and tested to select those with better performance and/or specific technological properties. The present review proposes a global survey of this massive ex-situ preservation of eukaryotic microorganisms, a reservoir of biotechnological solutions for the wine sector, overviewing relevant screenings that led to the selection of strains from 12 genera and 22 species of oenological significance. In the first part, the attention goes to the selection programmes related to relevant wine-producing areas (i.e. Douro, Extremadura, Galicia, La Mancha and Uclés, Ribera del Duero, Rioja, Sherry area, and Valencia). In the second part, the focus shifted on specific non-Saccharomyces genera/species selected from different Spanish and Portuguese regions, exploited to enhance particular attributes of the wines. A fil rouge of the dissertation is the design of tailored biotechnological solutions for wines typical of given geographic areas.

AB1356-HPR GOUT IN SPANISH PRIMARY HEALHCARE CENTERS: STILL A LONG WAY TO GO

Background:

Gout has a prevalence >2.5% in the Spanish adult population. It is a chronic disease that without proper treatment causes pain, joint deformity and increased cardiovascular risk and mortality. Recent advances have demonstrated that if correctly treated the disease can be controlled and even ‘cured’. Most gouty patients are diagnosed and treated by general practitioners (GPs). There is evidence that the management if these patients is not good neither at Rheumatology Units nor at Primary Healthcare (PHC) centers.Several causes of this mismanagement can be found in the literature.

Objectives:

Design and evaluation of the results of a questionnaire created from a bibliographic search focused on areas of improvement of gout management in PHC.

Methods:

A search was made in Pubmed to identify the main barriers described in the management of patients with gout in primary care. The terms used were: “Gout”, “primary healthcare” and “education”. A Google Form of gout knowledge and management questionnaire was designed, taking into account what is described in the literature. The Google Form was sent to all GP from an urban area via mail and to other contacts via WhatsApp and twitter.

Results:

Responses were obtained from 224 GPs; 69.5% were women; 73.1% had between 11 and 30 years of professional experience; 96.4% answered that gouty are mostly controlled in primary care; 99.6% performs the diagnosis of gout without analysis of synovial fluid and 17% diagnosed only by clinics without urate levels; 55.9% of GPs do not use any reference guide. Of those who use, the 73% use GUIPCLINGOT and 40% use SEMGs one; 80.5% have not done any gout course in the last 5 years; 26% did not have access to a rheumatologist to confirm the gout diagnosis; only 30.8% knew the therapeutic objective of the urate lowering therapy (ULT); 28.6% considered the beginning of ULT after the first attack; 62% believed that the most important part of the treatment was changing diet and lifestyles; 88.8% did not perform any specific education for these patients by the nurse; just 37.2% carried out a treat-to-target strategy to lower urate levels.

Conclusion:

The questionnaire identifies multiple points of improvement for the management of this pathology in accordance with the described in the literature. Most GPs are unaware of the therapeutic objective of the ULT.

Disclosure of Interests:

None declared

Chiral asymmetry detected in a 2D array of permalloy square nanomagnets using circularly polarized x-ray resonant magnetic scattering

The sensitivity of circularly polarized x-ray resonant magnetic scattering (CXRMS) to chiral asymmetry has been demonstrated. The study was performed on a 2D array of Permalloy (Py) square nanomagnets of 700 nm lateral size arranged in a chess pattern, in a square lattice of 1000 nm lattice parameter. Previous x-ray magnetic circular dichroism photoemission electron microscopy (XMCD-PEEM) images on this sample showed the formation of vortices at remanence and a preference in their chiral state. The magnetic hysteresis loops of the array along the diagonal axis of the squares indicate a non-negligible and anisotropic interaction between vortices. The intensity of the magnetic scattering using circularly polarized light along one of the diagonal axes of the square magnets becomes asymmetric in intensity in the direction transversal to the incident plane at fields where the vortex states are formed. The asymmetry sign is inverted when the direction of the applied magnetic field is inverted. The result is the expected in the presence of an unbalanced chiral distribution. The effect is observed by CXRMS due to the interference between the charge scattering and the magnetic scattering.

Nanoscale imaging of buried topological defects with quantitative X-ray magnetic microscopy

Advances in nanoscale magnetism increasingly require characterization tools providing detailed descriptions of magnetic configurations. Magnetic transmission X-ray microscopy produces element specific magnetic domain images with nanometric lateral resolution in films up to ∼100 nm thick. Here we present an imaging method using the angular dependence of magnetic contrast in a series of high resolution transmission X-ray microscopy images to obtain quantitative descriptions of the magnetization (canting angles relative to surface normal and sense). This method is applied to 55–120 nm thick ferromagnetic NdCo₅ layers (canting angles between 65° and 22°), and to a NdCo₅ film covered with permalloy. Interestingly, permalloy induces a 43° rotation of Co magnetization towards surface normal. Our method allows identifying complex topological defects (merons or ½ skyrmions) in a NdCo₅ film that are only partially replicated by the permalloy overlayer. These results open possibilities for the characterization of deeply buried magnetic topological defects, nanostructures and devices.

Transmission X-ray microscopy allows for the imaging of magnetic domains in thin film materials. Here, the authors exploit the angular dependence of the magnetic contrast to extract out-of-plane canting angles of stripe domains and topological defects in NdCo₅ films buried under a NiFe layer.

A soft X-ray beamline for transmission X-ray microscopy at ALBA

The MISTRAL beamline is one of the seven phase-I beamlines at the ALBA synchrotron light source (Barcelona, Spain) that will be opened to users at the end of 2010. MISTRAL will be devoted to cryotomography in the water window and multi-keV spectral regions for biological applications. The optics design consists of a plane-grating monochromator that has been implemented using variable-line-spacing gratings to fulfil the requirements of X-ray microscopy using a reflective condenser. For instance, a fixed-focus condition independent of the included angle, constant magnification as well as coma and spherical aberration corrections are achieved with this system. The reported design is of wider use.

Radiation effects analysis in a group of interventional radiologists using biological and physical dosimetry methods

Interventional radiologists and staff members are frequently exposed to protracted and fractionated low doses of ionizing radiation, which extend during all their professional activities. These exposures can derive, due to the effects of direct and scattered radiation, in deterministic effects (radiodermitis, aged skin, cataracts, telangiectasia in nasal region, vasocellular epitelioms, hands depilation) and/or stochastic ones (cancer incidence). A methodology has been proposed for estimating the radiation risk or detriment from a group of six exposed interventional radiologists of the Hospital Universitario La Fe (Valencia, Spain), which had developed general exposition symptoms attributable to deterministic effects of ionizing radiation. Equivalent doses have been periodically registered using TLD's and wrist dosimeters, H(p)(10) and H(p)(0.07), respectively, and estimated through the observation of translocations in lymphocytes of peripheral blood (biological methods), by extrapolating the yield of translocations to their respective dose-effect curves. The software RADRISK has been applied for estimating radiation risks in these occupational radiation exposures. This software is based on transport models from epidemiological studies of population exposed to external sources of ionizing radiation, such as Hiroshima and Nagasaki atomic bomb survivors [UNSCEAR, Sources and effects of ionizing radiation: 2006 report to the general assembly, with scientific annexes. New York: United Nations; 2006]. The minimum and maximum average excess ratio for skin cancer has been, using wrist physical doses, of [1.03x10(-3), 5.06x10(-2)], concluding that there is not an increased risk of skin cancer incidence. The minimum and maximum average excess ratio for leukemia has been, using TLD physical doses, of [7.84x10(-2), 3.36x10(-1)], and using biological doses, of [1.40x10(-1), 1.51], which is considerably higher than incidence rates, showing an excess radio-induced risk of leukemia in the group under study. Finally, the maximum radiological detriment in the group, evaluated as the total number of radio-induced cancers using physical dosimetry, has been of 2.18/1000 person-year (skin and leukemia), and using biological dosimetry of 9.20/1000 PY (leukemia). As a conclusion, this study has provided an assessment of the non-deterministic effects (rate of radio-induced cancer incidence) attributable to the group under study due to their professional activity.

Regulation of hdc expression and HDC activity by enological factors in lactic acid bacteria

AIMS

The aim of this work was to study the influence of enological factors on the histidine decarboxylase gene (hdc) expression and on histidine decarboxylase enzyme (HDC) activity in Lactobacillus hilgardii, Pediococcus parvulus and Oenococcus oeni.

METHODS AND RESULTS

Cell extracts and whole cells were used. Glucose, fructose, malic acid and citric acid diminished the hdc expression. Ethanol did not increase hdc expression or activity in cells, but increased HDC activity. Temperature and pH had effect on the activity of HDC but not on hdc expression. Tartaric acid and l-lactic acid, and sulphur dioxide (SO(2)) had no effect on enzyme synthesis and activity. Bacterial species differ in the relative enzymatic activity but all the factors affected similarly to L. hilgardii, P. parvulus and O. oeni.

CONCLUSIONS

The hdc gene expression was lowered by glucose, fructose, malic acid, and citric acid, whereas ethanol enhanced the HDC enzyme activity. The conditions that normally occur during malolactic fermentation and later on, could favour histamine production. SO(2) could prevent bacterial growth, but does not diminish the HDC enzyme activity.

SIGNIFICANCE AND IMPACT OF THE STUDY

Information on hdc expression and HDC activity can contribute to the prevention of histamine formation during wine production and storage.

Evaluation of DR and CR digital mammography systems based on phantom and breast dosimetry

Digital mammography has been progressively introduced in screening centers, since recent evolution of CR and DR detectors. However, it is questionable which exposure conditions would be more suitable when these techniques are applied, in order to reduce the glandular breast doses, as they are related with induced carcinogenesis. Several exposures have been performed in CR and DR mammography units for comparing absorbed doses during quality control assessments and during screening, diagnosis and treatment. In the first case, the CIRS11A mammographic phantom has been used with standard exposure conditions (28 kV, AEC mode with blackening +0, 50:50 glandularity and 4.5 compressed breast thickness) in order to obtain reference values for the standard breast. After that, a sample population of 100 women per mammography unit has been registered for performing a dosimetry study during clinical conditions, using the SCREENDOSE software developed by the authors. Results show that there are significative differences among the mammography units, proving that this methodology could be used for obtaining an objective criterion during the selection of a mammography unit, related with a minimum image quality level for a given clinical use (screening, diagnosis or treatment).

Accelerating Monte Carlo image reconstruction of a PMMA phantom through variance reduction techniques for quality control in digital mammography

Mammography is a non-invasive technique used for the detection of breast lesions. The use of this technique in a breast screening program requires a continuous quality control testing in mammography units for ensuring a minimum absorbed glandular dose without modifying image quality. Digital mammography has been progressively introduced in screening centers, since recent evolution of photostimulable phosphor detectors. The aim of this work is the validation of a methodology for reconstructing digital images of a polymethyl-methacrylate (PMMA) phantom (P01 model) under pure Monte Carlo techniques. A reference image has been acquired for this phantom under automatic exposure control (AEC) mode (28 kV and 14 mAs). Some variance reduction techniques (VRT) have been applied to improve the efficiency of the simulations, defined as the number of particles reaching the imaging system per starting particle. All images have been used and stored in DICOM format. The results prove that the signal-to-noise ratio (SNR) of the reconstructed images have been increased with the use of the VRT, showing similar values between different employed tallies. As a conclusion, these images could be used during quality control testing for showing any deviation of the exposition parameters from the desired reference level.

Pulse and energy pulse height tally comparison in breast dosimetry with Monte Carlo radiation transport codes: MCNP5 and PENEASY(2005)

The authors present a review of tallying processes with non-Boltzmann tallies under Monte Carlo simulations. A comparison between different pulse and energy pulse height tallies has been done with MCNP5 code and PENEASY, a user-friendly version of PENELOPE code. Several simulations have been done for estimating the pulse and energy deposited spectra in a polymethyl-methacrilate (PMMA) phantom used during quality control testing in digital mammography. In the case of MCNP5, the arbitrary energy-loss which is activated by default for particles just crossing the detector has been removed for comparing the efficiency of the tally. PENEASY works similarly, counting all scores which have or have not deposited energy in the phantom. A correction has been done to the code to remove this scoring. As derived from the results, the deposited energy has been estimated as 3.73369e-3 MeV/particle for MCNP5 and 3.25468e-3 MeV/particle for PENASY. Further studies are necessary to obtain more accurate results modeling the compression plate and the imaging system. Pulse and energy pulse height spectra are still tallies under development and all effort must be done to understand the tallying process under different applications.

Monte Carlo image reconstruction of a mammographic phantom

The aim of this study is the development of a methodology to reconstruct via Monte Carlo techniques the radiographic image of the CIRS 11 A (MAMMO PHANTOM SP01) phantom. This phantom is used in image quality assessment during quality control tests in breast screening locations and other health centers. The mammographic phantom is comprised of a reference point, a glandular tissue step wedge, contrast and resolution targets, and groups of microcalcifications and fibers. The MCNP radiation transport code (version 4c2) has been modified and recompiled to let use of a large number of tallies and detectors per input file, and an azimuthal directional source biasing. The output surface air kerma (OSAK) delivered by the X-rays has been scored employing a rectangular matrix of point detectors (F5 tally) under the phantom, simulating the image system. Some variance reduction techniques have been implemented to ensure that photons reach the detectors and that weight fluctuations were reduced. The characteristic curve of the film-scanner imaging system combination has been obtained throughout several experimental measures with an aluminium sensitometric wedge and Monte Carlo simulations. The reconstructed images agree with the range of values, indicating that this method would be suitable for training purposes, phantom designing or dose calculations.

Which lactic acid bacteria are responsible for histamine production in wine?

AIMS

To quantify the ability of 136 lactic acid bacteria (LAB), isolated from wine, to produce histamine and to identify the bacteria responsible for histamine production in wine.

METHODS AND RESULTS

A qualitative method based on pH changes in a plate assay was used to detect wine strains capable of producing high levels of histamine. Two quantitative, highly sensitive methods were used, an enzymatic method and HPLC, to quantify the histamine produced by LAB. Finally, an improved PCR test was carried out to detect the presence of histidine decarboxylase gene in these bacteria. The species exhibiting the highest frequency of histamine production is Oenococcus oeni. However, the concentration of histamine produced by this species is lower than that produced by strains belonging to species of Lactobacillus and Pediococcus. A correlation of 100% between presence of histidine decarboxylase gene and histamine production was observed. Wines containing histamine were analysed to isolate and characterize the LAB responsible for spoilage.

CONCLUSIONS

Oenococcus was able to synthesize low concentrations of histamine in wines, while Pediococcus parvulus and Lactobacillus hilgardii have been detected as spoilage, high histamine-producing bacteria in wines.

SIGNIFICANCE AND IMPACT OF THE STUDY

Information regarding histamine-producing LAB isolated from wines can contribute to prevent histamine formation during winemaking and storage.

Structure and reactivity of surface oxides on Pt(110) during catalytic CO oxidation

We present the first structure determination by surface x-ray diffraction during the restructuring of a model catalyst under reaction conditions, i.e., at high pressure and high temperature, and correlate the restructuring with a change in catalytic activity. We have analyzed the Pt(110) surface during CO oxidation at pressures up to 0.5 bar and temperatures up to 625 K. Depending on the pressure ratio, we find three well-defined structures: namely, (i) the bulk-terminated Pt(110) surface, (ii) a thin, commensurate oxide, and (iii) a thin, incommensurate oxide. The commensurate oxide only appears under reaction conditions, i.e., when both and CO are present and at sufficiently high temperatures. Density functional theory calculations indicate that the commensurate oxide is stabilized by carbonate ions (CO3(2-)). Both oxides have a substantially higher catalytic activity than the bulk-terminated Pt surface.

Use of risk projection models to estimate mortality and incidence from radiation-induced breast cancer in screening programs

The authors report on a method to calculate radiological risks, applicable to breast screening programs and other controlled medical exposures to ionizing radiation. In particular, it has been applied to make a risk assessment in the Valencian Breast Cancer Early Detection Program (VBCEDP) in Spain. This method is based on a parametric approach, through Markov processes, of hazard functions for radio-induced breast cancer incidence and mortality, with mean glandular breast dose, attained age and age-at-exposure as covariates. Excess relative risk functions of breast cancer mortality have been obtained from two different case-control studies exposed to ionizing radiation, with different follow-up time: the Canadian Fluoroscopy Cohort Study (1950--1987) and the Life Span Study (1950--1985 and 1950--1990), whereas relative risk functions for incidence have been obtained from the Life Span Study (1958--1993), the Massachusetts tuberculosis cohorts (1926--1985 and 1970--1985), the New York post-partum mastitis patients (1930--1981) and the Swedish benign breast disease cohort (1958--1987). Relative risks from these cohorts have been transported to the target population undergoing screening in the Valencian Community, a region in Spain with about four and a half million inhabitants. The SCREENRISK software has been developed to estimate radiological detriments in breast screening. Some hypotheses corresponding to different screening conditions have been considered in order to estimate the total risk associated with a woman who takes part in all screening rounds. In the case of the VBCEDP, the total radio-induced risk probability for fatal breast cancer is in a range between [5 x 10(-6), 6 x 10(-4)] versus the natural rate of dying from breast cancer in the Valencian Community which is 9.2 x 10(-3). The results show that these indicators could be included in quality control tests and could be adequate for making comparisons between several screening programs.

Polyphasic study of wine Lactobacillus strains: taxonomic implications

One hundred and seventy-eight lactobacilli isolated from wine were characterized by a polyphasic approach. Strains were phenotypically identified at genus and species level by classical tests including the analysis of cell morphology, homo/heterofermentative character, sugar fermentation patterns, growth at different temperatures and the optical nature of the isomer of lactic acid produced from glucose. Molecular techniques such as random amplification of polymorphic DNA (RAPD), amplified 16S rDNA restriction analysis (16S-ARDRA), PFGE-RFLP and ribotyping were used to characterize strains, and their potential for identification and/or typing was evaluated. The information obtained with these techniques was processed with the BioNumerics software in order to analyse relationships existing between isolated strains and various reference species of the genus. Then, taxonomic dendrograms were obtained, and this information allowed the proposal of molecular procedures suitable for the identification and typing of these wine micro-organisms. The techniques useful for both identification and typing were RAPD and ribotyping, while 16S-ARDRA was only useful for identification and PFGE-RFLP only for typing purposes. The wine strains were identified as Lactobacillus brevis (19 strains), Lactobacillus collinoides (2 strains), Lactobacillus hilgardii (71 strains), Lactobacillus paracasei (13 strains), Lactobacillus pentosus (2 strains), Lactobacillus plantarum (34 strains) and Lactobacillus mali (10 strains).

Modelling of the mammographic exposure conditions for radiological detriment study in the Valencian Breast Cancer Screening Programme

Breast screening programmes are the best weapon to fight against breast cancer. Nevertheless, despite the benefits, this practice supposes a radiological risk that cannot be forgotten. In order to calculate breast glandular doses, different MCNP-4C2 models have been developed, simulating the exposure conditions. Radiological detriments have been transported from the population under study in the UNSCEAR 2000 to the Valencian Community, obtaining the detection-induced cancer ratio (DICR) for this population.

Improved enzymatic method for the rapid determination of histamine in wine

Fermented foods are frequently contaminated by histamine generated by microorganisms possessing histidine decarboxylase activity. The ingestion of large amounts of histamine can cause serious toxicological problems in man. Thus, it becomes important to set a reliable method for rapid histamine quantification in foods. The detection of bacteria exhibiting histidine decarboxylase activity is also important to estimate the risk of contamination of food. Previous enzymatic methods used to quantify histamine in fish gave erroneously high values due to interference when applied to wine. A new enzymatic method is described that allows the direct determination of histamine concentrations in this type of sample. It can be used for the detection of histamine in synthetic media, grape must or wine (white, rose, red) without polyphenols or sugar interferences. This new enzymatic method shows a good correlation (R2 = 0.996, p < 0.001) between the histamine concentrations and absorbances in the interval 0.4-160 mg l(-1). Comparison between this enzymatic method and a high-performance liquid chromatography method showed a high correlation (R2 =0.9987, p<0.001). A miniaturized enzymatic method is also proposed, which is particularly useful when high numbers of samples must be analysed.

High seroprevalence of Pneumocystis infection in Spanish children

Pneumocystis infection occurs worldwide, and most individuals test seropositive for Pneumocystis early in childhood. Little is known about the epidemiology of this infection in western Europe. The seroprevalence of Pneumocystis infection in 233 Spanish children was determined in a community study by immunoblot analysis of sera. The overall seroprevalence was 73%, with an age-related increase from 52% at 6 years to 66% at 10 years and 80% at 13 years. The data indicated a high seroprevalence of Pneumocystis infection in healthy Spanish children, thereby demonstrating that this pathogen is widespread in southern Spain.

New insights in the c(4 x 2) reconstruction of hexadecanethiol on Au(111) revealed by grazing incidence X-ray diffraction

The c(4 x 2) structure of C16H33SH alkanethiol monolayers self-assembled on Au(111) has been studied by grazing incidence X-ray diffraction. This structure coexists on the surface with the (radical3x radical3)R30 degrees phase. The structural refinement of the c(4 x 2) phase has been accomplished by omitting the fractional order reflections common to both structures. The surface unit cell consists of four symmetry-independent molecules with atomic displacements related by couples, such that only two nonequivalent chains are present in the surface cell. The stability between neighbor chains is due to van der Waals interactions. The substrate plays an important and non-negligible role in the c(4 x 2) reconstruction. The lateral and normal substrate relaxations to the surface plane are small, and gold atom displacements are lower than 0.25 angstroms but contribute very strongly to the fractional order intensities. The molecular chains form a close packed structure tilted by 37 degrees from the surface normal with no indications of dimer formation between closest S atoms.

Spin reorientation and structural relaxation of atomic layers: pushing the limits of accuracy

The correlation between an ad-layer-induced spin reorientation transition (SRT) and the ad-layer-induced structural relaxation is investigated by combined in situ surface x-ray diffraction and magneto-optical Kerr-effect experiments on Ni/Fe/Ni(111) layers on W(110). The Fe-induced SRT from in-plane to out-of-plane, and the SRT back to in-plane upon subsequent coverage by Ni, are each accompanied by a small lattice relaxation of at most 0.002 A. Such a small strain variation excludes a magnetoelasticity driven SRT, and we suggest the interface anisotropy as a possible driving force.

Functional Superoxide Dismutase Mimics. Structural Characterization and Magnetic Exchange Interactions of Copper(II)−N-Substituted Sulfonamide Dimer Complexes

Dinuclear copper(II) complexes with N-substituted sulfonamide ligands as superoxide dismutase (SOD) mimics have been investigated. The new N-(thiazol-2-yl)toluenesulfonamide (Htz-tol) and N-(thiazol-2-yl)naphthalenesulfonamide (Htz-naf) ligands have been prepared and structurally characterized. The complexes derived from these ligands, [Cu(2)(tz-tol)(4)] (1) and [Cu(2)(tz-naf)(4)] (2), have been synthesized, and their crystal structure, magnetic properties, and EPR spectra were studied in detail. In both compounds the metal centers are bridged by four nonlinear triatomic NCN groups. The coordination geometry of the coppers in the dinuclear entity of 1 and 2 is distorted square planar with two N-thiazole and two N-sulfonamido atoms. Magnetic susceptibility data show a strong antiferromagnetic coupling, with -2J = 121.3 cm(-1) for compound 1 and -2J = 104.3 cm(-1) for compound 2. The EPR spectra of the polycrystalline samples of compounds 1 and 2 have been measured at the X- and Q-band frequencies at different temperatures. Above 20 K the spectra are characteristic of S = 1 species with zero-field splitting parameter D = 0.230 cm(-1) for compound 1 and 0.229 cm(-1) for compound 2. The EPR parameters are discussed in terms of the known binuclear structures. The complexes exhibit high SOD activity, as shown by the low IC(50) values obtained with the xanthine/xanthine oxidase/NBT assay: 0.13 microM for compound 1; 0.17 microM for compound 2.

A randomized study of intermediate as compared with high doses of interferon-alpha for chronic myeloid leukemia: no differences in cytogenetic responses

Interferon-alpha (IFN-alpha) is a therapy of unquestionable efficacy in chronic myeloid leukemia (CML) patients. The best dose of IFN-alpha in the treatment of CML still remains controversial. Our primary objective was to compare cytogenetic responses in patients treated with intermediate versus high doses of IFN-alpha. A multicenter randomized controlled trial was conducted involving 109 patients with untreated CML in chronic phase from 26 Spanish hospitals. Patients were assigned to receive either an intermediate (2.5 MU/m(2) per day) or high (5 MU/m(2) per day) target dose of IFN-alpha. Hydroxyurea was allowed in both groups. In total, 108 patients were analyzed, 53 in the intermediate- and 55 in the high-dose group. Median follow-up was 47.5 months. The dose of IFN-alpha actually given was lower in the intermediate-dose group (3.83 MU/day) than in the high-dose group (6.6 MU/day) ( p<0.001). The rate of complete cytogenetic response was 24.5% in the intermediate- and 12.7% in the high-dose group (NS). A partial cytogenetic response was obtained in 7.5% and 10.9%, respectively. Cox analysis did not reveal any influence of the randomization arm on cytogenetic response rate. Ten patients in each group discontinued IFN-alpha because of toxicity. Albeit not our primary objective, no differences were found in terms of survival or transformation rate between both groups. Median survival was 73 months; 64% of patients remained free of transformation at 5 years. In terms of cytogenetic response, intermediate doses of IFN-alpha are as effective as high doses in the treatment of CML.

Antifungal activities of two new azasordarins, GW471552 and GW471558, in experimental models of oral and vulvovaginal candidiasis in immunosuppressed rats

Sordarins constitute a new class of antifungal agents with a novel mechanism of action involving the selective inhibition of fungal protein synthesis. A further evolution of this class of antifungals has led to a new family of sordarin derivatives called azasordarins. The therapeutic efficacies of two new azasordarins, GW471552 and GW471558, were studied in experimental models of oral and vulvovaginal candidiasis in immunosuppressed rats. In all cases rats were immunosuppressed with dexamethasone in the drinking water. Oral candidiasis was established by inoculating 0.1 ml of a yeast suspension containing 5 x 10(8) cells of Candida albicans 4711E with a cotton swab on three alternate days. Vulvovaginal candidiasis was established in ovariectomized and estrus-induced rats by intravaginal inoculation of 10(7) CFU of C. albicans 4711E in 0.1 ml of saline. GW471552 and GW471558 were administered at 1, 5, and 10 mg/kg of body weight via the subcutaneous route. In oral candidiasis, azasordarins were administered each 8 h for 7 consecutive days, while in vaginal candidiasis the compounds were given each 4 h for 3 consecutive days. Antifungal activity of azasordarins was assessed by colony counts and by histological examination 1 day after treatment. In the oral infection model, GW471552 and GW471558 administered at 5 mg/kg significantly reduced (P < 0.05) the number of CFU of C. albicans compared with untreated controls. In addition, GW471552 and GW471558 given at 10 mg/kg eradicated C. albicans from the oral cavities of 100% of infected animals. Against vulvovaginal infection, both compounds showed significant therapeutic efficacy. GW471552 was able to eradicate the vaginal fungal burden at a dose of 10 mg/kg, and it significantly reduced the number of CFU of C. albicans in vaginas of rats treated with a dose of 5 mg/kg (P < 0.05). GW471558 showed greater efficacy, eradicating the fungal burden of 100% of infected rats at a dose of 5 mg/kg and significantly reducing (P < 0.05) the C. albicans vaginal counts even at a dose of 1 mg/kg. In both therapeutic efficacy studies, the histological findings confirmed the microbiological results. The experimental results presented show that the tested azasordarins are effective against oral and vulvovaginal candidiasis in immunosuppressed rats and could be promising antifungal agents for use in humans.

Antibacterial activities and pharmacokinetics of E-4767 and E-5065, two new 8-chlorofluoroquinolones with a 7-azetidin ring substituent

E-4767 [(-)-7-[3-(R)-amino-2-(S)-methyl-1-azetidinyl]-8-chloro-1-cyclopropyl-1,4-dihydro-6-fluoro-4-oxo-3-quinolinecarboxylic acid] and E-5065 [(-)-7-(3-amino-1-azetidinyl)-8-chloro-1-cyclopropyl-1,4-dihydro-6-fluoro-4-oxo-3-quinolinecarboxylic acid] are two new chlorofluoroquinolones with an azetidine moiety at position 7. Their in vitro activities were evaluated in comparison with those of ciprofloxacin, ofloxacin, fleroxacin, and tosufloxacin, while ciprofloxacin was used as a reference for in vivo studies. Against gram-positive organisms, E-4767 and E-5065 were, in general, eight- and fourfold more active than tosufloxacin, which is the most potent of the reference compounds. E-4767 and E-5065 were also more potent than the reference compounds against all species of enteric bacteria tested. The MICs of E-4767 and E-5065 at which 90% of the isolates tested were inhibited (MIC(90)s) were 0.007 to 0.5 microg/ml and 0.03 to 2 microg/ml, respectively, for gram-positive organisms and <or=0.003 to 0.06 microg/ml and 0.007 to 0.12 microg/ml, respectively, for members of the family Enterobacteriaceae except Serratia marcescens and Providencia spp. (MIC(90)s of E-4767 and E-5065 for these species were <or=0.5 microg/ml and <or=2 microg/ml, respectively). For Pseudomonas aeruginosa both compounds had a MIC(90) of 0.5 microg/ml. E-4767 and E-5065 were 356- and 32-fold more potent than ciprofloxacin against Bacteroides spp., and their MIC(90)s for Clostridium spp. were 0.25 and 0.5 microg/ml, respectively. Both products showed a remarkable reduction of activity when the pH was below 4.8 and, in general, were less active in the presence of 5 or 10 mM Mg(2+). The presence of horse serum or human urine (pH 7.2) decreased the activity of E-4767 and E-5065 only two- to fourfold more than the activity observed in broth. After an oral dose of 50 mg/kg of body weight, the maximum levels in serum (the maximum concentration of drug in serum was reached 30 min postadministration) of E-4767 and E-5065 were approximately threefold higher than that of ciprofloxacin. The area under the concentration-time curve from 0 to 4 h for ciprofloxacin was about two- and fourfold lower than that for E-4767 and E-5065, respectively. These two new chlorofluoroquinolones were as effective as or more effective than ciprofloxacin against all experimental infections evaluated, not only against gram-negative bacteria, such as Escherichia coli or P. aeruginosa, but also against gram-positive pathogens, such as Staphylococcus aureus or Streptococcus pneumoniae. E-4767 was the most effective compound, with a 50% effective dose (ED(50)) of <or=17 mg/kg for all strains tested except ciprofloxacin-resistant S. aureus strains. The ED(50) of E-4767 for these strains was <or=47.5 mg/kg. Against gram-positive experimental infections, the ED(50) values of E-4767 were 3- to 14-fold lower than those of E-5065 and up to 25 times lower than those of ciprofloxacin.