bluuebunny/crossref_metadata_2025 huggingface dataset:
Differentialdiagnose renaler Erkrankungen mit der Urinprotein-Elektrophorese (SDS-PAGE) Differential diagnosis of renal diseases by urinary protein electrophoresis (SDS-PAGE)
Authors: Becker Andreas , Boesken Wolf H.
Published: October 2005

Die SDS-Discelektrophorese (SDS-PAGE) trennt Proteine nach dem Molekulargewicht und erlaubt die qualitative und semiquantitative Analyse der mit dem Urin ausgeschiedenen Eiweiße. Im Gegensatz zur Einzelproteinanalyse werden keine Konzentrationen von Markerproteinen gemessen, sondern es werden alle im Urin vorhandenen Proteine mit einem Molekulargewicht zwischen etwa 10 und 800 kDa dargestellt. Da die pathophysiologischen Prozesse im Nephron sich im Wesentlichen in der molekularen Größe der Urineiweiße widerspiegeln, lassen die elektrophoretischen Muster Rückschlüsse auf das Vorliegen einer glomerulären und/oder tubulären Schädigung und auf prä- und postrenale Prozesse zu. Sie ermöglichen somit die Bestimmung der Lokalisation der Erkrankung am Nephron, nicht aber die Diagnose der zugrunde liegenden Ursache. Im klinischen Alltag gibt die Untersuchung damit wertvolle Hinweise auf die Natur der Erkrankung und leistet Hilfestellung bei der Entscheidung, ob eine Biopsie zur weiteren Abklärung erforderlich ist. Daneben liefert sie insbesondere bei Verlaufsuntersuchungen Hinweise in Bezug auf die Prognose und lässt bei Veränderungen im Verlauf Remissionen, Rezidive und Progression erkennen.
Fallbericht eines falsch-positiven Hepatitis C-Virus-diagnostischen Befundes mit weitreichenden Folgen Case report on a false positive hepatitis C diagnostic result with far-reaching consequences
Authors: Rabenau Holger F. , Werwatz Gudrun , Teuber Gerlinde , Gottschalk Rene , Wicker Sabine , Berger Annemarie , Wilhelm Doerr Hans
Published: October 2005

Im vorliegenden Fall wird von einer Fehldiagnose auf der Grundlage eines falsch-reaktiven Anti-HCV-Tests und eines falsch-reaktiven HCV-Nukleinsäureamplifikationstests (NAT) berichtet, die bei einem 58-jährigen chirurgischen Oberarzt im Rahmen einer arbeitsmedizinischen Vorsorgeuntersuchung im krankenhauseigenen Labor gestellt wurde und zu einem knapp zweimonatigen Berufsverbot führte. Basis dieser Fehldiagnose war ein wiederholt schwach reaktiver HCV-Antikörper-ELISA, der mit einem Nukleinsäureamplifikationstest, der ebenfalls schwach positiv ausfiel, überprüft wurde. Ein Antikörperbestätigungs- bzw. Ergänzungstest (Immunoblot) wurde nicht durchgeführt. Die Fehldiagnose ist jedoch nicht durch einen Testfehler, sondern durch ein Missverständnis entstanden, indem beim Kliniker zwei Laborindizien zu einem Beweis aufsummiert wurden.
Effect of pH on the toxicity of nickel and other divalent metals to Burkholderia cepacia PR1301
Authors: Van Nostrand Joy D. , Sowder Andrew G. , Bertsch Paul M. , Morris Pamela J.
Published: October 2005

Nickel (Ni) is a common cocontaminant at many waste sites where the soils and sediments often are acidic, thereby influencing metal availability. Growth of Burkholderia cepacia PR1301 was not affected at 3.41 mM Ni at pH 5, but was inhibited by 73.2% at pH 6 and inhibited completely at pH 7 compared to growth without Ni. This pH effect was not observed in the Niresistant strains, Ralstonia metallidurans CH34 and 31A. Predicted Ni speciation did not explain the observed toxicity trends. Sorption of Ni to PR1 increased with increasing pH (1.49, 1.12, and 3.88 mg Ni/g dry weight at pH 5, 6, and 7, respectively), but was low at all three pH values, and most likely does not explain the observed pH effect. Growth inhibition of PR1 with increasing pH also was observed for other divalent cations, with growth observed at 4.24 mM Co, 2.22 mM Cd, and 3.82 mM Zn at pH 5 and 6, but totally inhibited at pH 7. These studies suggest that, at circumneutral pH, PR1 would be considered sensitive to Ni and other divalent cations, in spite of the ability to grow in higher concentrations at lower pH values.
Heterogeneity of natural organic matter amelioration of silver toxicity to Daphnia magna: Effect of source and equilibration time
Authors: Glover Chris N. , Playle Richard C. , Wood Chris M.
Published: October 2005

Despite the heterogeneity of natural organic matter (NOM) in the aquatic environment, current models that predict metal toxicity to aquatic biota treat these important metal-complexing agents in a homogeneous manner. In this investigation, the ability of 11 commercial and naturally isolated NOM samples to ameliorate silver toxicity to the freshwater crustacean Daphnia magna was examined. The commercially available Aldrich humic acid (AHA) increased the 48-h median lethal concentration for daphnid neonates from nominally NOM-free levels of 0.29 to 3.80 μg/L (at 6.9 mg C/L) in a concentration-dependent manner. Three of the tested samples exhibited similar protective effects, but the additional seven NOM samples displayed significantly stronger ameliorative actions. In fact, four samples of both commercial and naturally isolated origin demonstrated greater than fourfold increases in protection compared to that of AHA. Additional investigations showed that increased silver-AHA equilibration time resulted in decreased toxicity. Increased equilibration time also decreased whole-body silver accumulation at NOM levels less than 1 mg C/L. The present results suggest that heterogeneity of NOM and silver-NOM equilibration time will have to be accounted for in future models of silver toxicity to D. magna and that laboratory toxicity testing using NOM and metals should account for the effects of metal-NOM equilibration time.
Delineating copper accumulation pathways for the freshwater bivalve Corbicula using stable copper isotopes
Authors: Croteau Marie-Noéle , Luoma Samuel N.
Published: October 2005

Delineation of metal uptake routes in aquatic invertebrates is critical for characterizing bioaccumulation dynamics and assessing risks associated with metal exposure. Here we demonstrate that Cu stable isotopic ratios can be manipulated in both exposure media and algae to determine the efflux rate constant (ke) and to estimate Cu assimilation efficiency (AE) from ingested food in a freshwater bivalve (Corbicula fluminea). The Cu AE in Corbicula fed 65Cu-spiked Cryptomonas ozolini was 38%. Copper uptake routes had no significant influence on efflux; ke of 0.004 per day characterized the slowest component of efflux following short-term exposures to 65Cu in water or in both food and water. Incorporation of the physiological parameters for dietary and dissolved uptake as well as rate constants of loss into a bioaccumulation model allowed for assessing the relative contribution of water and food as Cu sources. At [65Cu2+] of 6.7 μg/L, Corbicula accumulated twice as much Cu from diet as from water. In most freshwater systems, the dietary pathway is likely to act as the major Cu uptake route for Corbicula. Extrapolation of our laboratory results to the San Francisco Bay—Delta (California, USA) indicated that our biodynamic model and the laboratory-derived parameters for dietary 65Cu uptake provided a realistic representation of the processes involved in Cu accumulation by the bivalve Corbicula.
Biotests and biosensors in ecotoxicological risk assessment of field soils polluted with zinc, lead, and cadmium
Authors: Kahru Anne , Ivask Angela , Kasemets Kaja , Pollumaa Lee , Kurvet Imbi , François Matthieu , Dubourguier Henri-Charles
Published: October 2005

The combined chemical and ecotoxicological hazard evaluations study was conducted on 60 smelter-influenced soils containing 1 to 13, 50 to 653, and 100 to 1,198 mg/kg of Cd, Pb, and Zn, respectively. For these soils (liquid-to-soil ratio = 10), water extractability of Zn, Cd, and Pb was less than 0.19% (median values). Acetic acid (0.11 M) extracted 23, 9.7, and 0.7% of Cd, Zn, and Pb, respectively. Although heavy metal concentrations in the studied soils were high, the toxic effects of water extracts were observed only in few samples and in few biotests (algae Selenastrum capricornutum and metal detector assay). For most of the aquatic test organisms (e.g., crustaceans, photobacteria), the bioavailable concentrations of metals in soil-water extracts were either subtoxic, or the adverse effects were compensated by soil nutrients, etc. However, analysis of the soils with recombinant Cd sensor Bacillus subtilis (pTOO24) showed that about 65% of these apparently subtoxic samples contained bioavailable Cd when analyzed in the suspension assay (detection limit 1.5 mg Cd/kg soil), indicating the desorption of Cd induced by direct contact of bacteria with soil particles. The median bioavailable fraction of Cd (1%) was 23-fold lower than the fraction extracted by acetic acid. The Pb-Cd sensor Staphylococcus aureus (pT0024) detected bioavailable Pb only in the suspensions of five of the most lead-polluted soils (>417 mg Pb/kg): the median bioavailability of Pb was 0.42%. Consequently, the hazard assessment relying on total metal levels in soils should be revised by critical comparison with data obtained from bioassays. Development and use of biosensors (excellent tools for mechanistic studies and signaling hazard already at subtoxic level) should be encouraged.
Biotransformation of the polycyclic aromatic hydrocarbon pyrene in the marine polychaete Nereis virens
Authors: Jørgensen Anne , Giessing Anders M. B. , Rasmussen Lene Juel , Andersen Ole
Published: October 2005

In vivo and in vitro biotransformation of the polycyclic aromatic hydrocarbon (PAH) pyrene was investigated in the marine polychaete Nereis virens. Assays were designed to characterize phase I and II enzymes isolated from gut tissue. High-pressure liquid chromatography measurement of 1-hydroxypyrene, pyrene-1-glucuronide, pyrene-1-sulfate, and pyrene-1-glucoside appeared to be a sensitive method for estimating the activity of pyrene hydroxylase, glucuronosyl transferase, and sulfotransferase. Total pyrene in gut tissue after a 5-d exposure to 10 μg/g dry weight pyrene constituted 65% pyrene-1-glucuronide, 12% pyrene-1-sulfate, 2% pyrene-1-glucoside, 4% 1-hydroxypyrene, and 17% pyrene, indicating that glucuronidation is the prominent phase II pathway in this organism. Only pyrene hydroxylase activity was induced significantly after pre-exposure to sediment-associated pyrene (10 μg/g dry wt). Apparent kinetic parameters were determined for all enzymatic reactions. Glucuronidation was confirmed as being the prominent phase II reaction, based on its high apparent maximum velocity (Vmax(a)). Sulfation had the lowest apparent Michaelis constant (Km(a)), indicating high specificity. Apparent kinetic parameters for pyrene hydroxylase activity were changed after induction with pyrene. Induced worms showed increased Vmax(a) and decreased Km(a) compared to noninduced worms, indicating that the relative amount of the cytochrome P450 enzyme(s) responsible for pyrene hydroxylation is increased. Our findings show that N. virens has a high biotransformation capacity for PAHs, with inducible pyrene hydroxylase activity, and that the most prominent phase II pathway in this organism is glucuronidation.
Fate of gasoline oxygenates in conventional and multilevel wells of a contaminated groundwater table in düsseldorf, Germany
Authors: Rosell Mònica , Lacorte Sílvia , Forner Claudia , Rohns Hans-Peter , Irmscher Rudolf , Barceló Damiá
Published: October 2005

In a gasoline-contaminated site in Düsseldorf, Germany a two-year monitoring program was carried out to determine the presence, behavior, and fate of 12 gasoline additives in a total of 96 samples from 14 groundwater wells. The origin of contamination was suspected to be a gasoline spill at a gas station. Target compounds were methyl-tert-butyl ether (MTBE), its main degradation products, tert-butyl alcohol (TBA) and tert-butyl formate (TBF); other gasoline additives, oxygenate dialkyl ethers: Ethyl-tert-butyl ether (ETBE), tert-amyl methyl ether (TAME) and diisopropyl ether (DIPE); aromatics: Benzene, toluene, ethylbenzene and xylenes (BTEX), and other compounds causing odor problems: Dicyclopentadiene and trichloroethylene. Purge and trap coupled with gas chromatography-mass spectrometry permitted detection of ng/L concentrations. Ninety of the 96 samples analyzed contained MTBE at levels varying between 0.01 to 645 μ/L. Five contaminated hot spots were identified with levels up to U.S. Environmental Protection Agency (U.S. EPA) drinking water advisory values (20–40 μ/L) and one of them doubling Danish suggested toxicity level of 350 μ/L at a depth of 11 m. No significant natural attenuation was found in MTBE degradation, although samples with high levels of MTBE contained 0.1 to 440 μg/L of TBA. These levels were attributed to its presence in the contamination source more than MTBE degradation. tert-Butyl alcohol was found to be recalcitrant in groundwater. In all cases, BTEX were at low concentrations or not detected, showing less persistence than MTBE. The monitoring of the contamination plume showed that the distribution of the MTBE and TBA in the aquifer formed a similar vertical concentration profile that was influenced by the groundwater flow direction.
Field‐Scale Evaluation of Phosphorus Leaching in Acid Sandy Soils Receiving Swine Waste
Authors: Nelson Nathan O. , Parsons John E. , Mikkelsen Robert L.
Published: October 2005

Accurate descriptions of P leaching are important because excess P applied to soils can enter surface water via leaching and subsurface transport, thereby negatively impacting water quality. The objectives of this study were to monitor P leaching in soils with a long‐term history of waste application, relate soil solution P concentrations to soil P status, and quantify P leaching losses. Soil solution was monitored for 20 mo with samplers installed at 45‐, 90‐, and 135‐cm depths in two pits (1 × 3 × 1.5 m) in Autryville (loamy, siliceous, thermic Arenic Paleudults) and Blanton (loamy, siliceous, semiactive, thermic Grossarenic Paleudults) soils located in a grazed pasture in Sampson County, NC, which had received swine waste for >20 yr. Maximum soil solution P concentrations at 45 cm exceeded 18 mg L−1 in both soils. Soil solution P concentrations at 90 cm in the Blanton soil were similar to that at 45 cm indicating low P sorption. Soil solution P concentrations at 90 cm in the Autryville soil averaged 0.05 mg L−1 compared to 10 mg L−1 at 45 cm. A split‐line model related soil solution P concentration to the degree of phosphorus saturation (DPS), identifying a change point at 45% DPS. Phosphorus movement past 45 cm equaled or exceeded surplus P additions for both soils. Long‐term waste applications resulted in DPS > 90%, high soil solution P concentrations, and substantial vertical P movement. Phosphorus leaching should be considered when assessing long‐term risk of P loss from waste‐amended soils.
Oxytetracycline Sorption to Organic Matter by Metal‐Bridging
Authors: MacKay Allison A. , Canterbury Brian
Published: October 2005

The sorption of oxytetracycline to metal‐loaded ion exchange resin and to natural organic matter by the formation of ternary complexes between polyvalent metal cations and sorbent‐ and sorbate ligand groups was investigated. Oxytetracycline (OTC) sorption to Ca‐ and Cu‐loaded Chelex‐100 resin increased with increasing metal/sorbate ratio at pH 7.6 (OTC speciation: 55% zwitterion, 45% anion). Greater sorption to Cu‐ than Ca‐loaded resin was observed, consistent with the greater stability constants of Cu with both the resin sites and with OTC. Oxytetracycline sorption to organic matter was measured at pH 5.5 (OTC speciation: 1% cation, 98% zwitterion, 1% anion). No detectable sorption was measured for cellulose or lignin sorbents that contain few metal‐complexing ligand groups. Sorption to Aldrich humic acid increased from “clean” < “dirty” (no cation exchange pretreatment) < Al‐amended < Fe(III)‐amended clean humic acid with Kd values of 5500, 32000, 48000, and 250000 L kg−1 C, respectively. Calcium amendments of clean humic acid suggested that a portion of the sorbed OTC was interacting by cation exchange. Oxytetracycline sorption coefficients for all humic acid sorbents were well‐correlated with the total sorbed Al‐plus‐Fe(III) concentrations (r2 = 0.87, log‐log plot), suggesting that sorption by ternary complex formation with humic acid is important. Results of this research indicate that organic matter may be an important sorbent phase in soils and sediments for pharmaceutical compounds that can complex metals by the formation of ternary complexes between organic matter ligand groups and pharmaceutical ligand groups.
Reducing Sediment and Phosphorus in Tributary Waters with Alum and Polyacrylamide
Authors: Mason L. B. , Amrhein C. , Goodson C. C. , Matsumoto M. R. , Anderson M. A.
Published: October 2005

The Salton Sea is the largest inland water body in California, covering an area of 980 km2 Inflow to the Salton Sea (1.6 km3 yr−1) is predominately nutrient‐rich agricultural wastewater, which has led to eutrophication. Because internal phosphorus release from the bottom sediments is comparatively low and external phosphorus loading to the Salton Sea is high, reduction of tributary phosphorus is expected to reduce algal blooms, increase dissolved oxygen, and reduce odors. Removing both dissolved phosphorus and phosphorus‐laden sediment from agricultural drainage water (ADW) should decrease eutrophication. Both alum and polyacrylamide (PAM) are commonly used in wastewater treatment to remove phosphorus and sediment and were tested for use in tributary waters. Laboratory jar tests determined PAM effectiveness (2 mg L−1) for turbidity reduction as cationic > anionic = nonionic. Although cationic PAM was the most effective at reducing turbidity at higher speeds, there was no observed difference between the neutral and anionic PAMs at velocity gradients of 18 to 45 s−1 Alum (4 mg L−1 Al) reduced turbidity in low energy systems (velocity gradients < 10 s−1) by 95% and was necessary to reduce soluble phosphorus, which comprises 47 to 100% of the total P concentration in the tributaries. When PAM was added with alum, the anionic PAM became ineffective in aiding flocculation. The nonionic PAM (2 mg L−1) + alum (4 mg L−1 Al) is recommended to reduce suspended solids in higher energy systems and reduce soluble P by 93%.
Modeling Tritium Transport Through a Deep Unsaturated Zone in an Arid Environment
Authors: Mayers C. J. , Andraski B. J. , Cooper C. A. , Wheatcraft S. W. , Stonestrom D. A. , Michel R. L.
Published: October 2005

Understanding transport of tritium (3H) in unsaturated zones is critical to evaluating options for waste isolation. Tritium typically is a large component of low‐level radioactive waste (LLRW). Studies at the U.S. Geological Survey's Amargosa Desert Research Site (ADRS) in Nevada investigate 3H transport from a closed LLRW facility. Two boreholes are 100 and 160 m from the nearest waste trench and extend to the water table at 110 m. Soil‐water vapor samples from the deep boreholes show elevated levels of 3H at all depths. The objectives of this study were to (i) test source thermal and gas‐advection mechanisms driving 3H transport and (ii) evaluate model sensitivity to these mechanisms and to selected physical and hydraulic properties including porosity, tortuosity, and anisotropy. A two‐dimensional numerical model incorporated a non‐isothermal, heterogeneous domain of the unsaturated zone and instantaneous isotopic equilibrium. The TOUGH2 code was used; however, it required modification to account for temperature dependence of both the Henry's law equilibrium constant and isotopic fractionation with respect to tritiated water. Increases in source temperature, pressure, and porosity enhanced 3H migration, but failed to match measured 3H distributions. All anisotropic simulations with a source pressure component resembled, in shape, the upper portion of the 3H distribution of the nearest borehole. Isotopic equilibrium limited migration of 3H, while effects of radioactive decay were negligible. A 500 Pa pressure increase above ambient pressure in conjunction with a high degree of anisotropy (1:100) was necessary for simulated 3H transport to reach the nearest borehole.
Contribution of multiplexed electrical resistance and magnetic techniques to the archaeological investigations at Poros, Greece
Authors: Papadopoulos N. G. , Sarris A. , Kokkinou E. , Wells B. , Penttinen A. , Savini E. , Tsokas G. N. , Tsourlos P.
Published: October 2005

The Sanctuary of Poseidon at Kalaureia is located on the island of Poros in the Saronic Gulf in Greece. Two Swedish archaeologists first carried out excavations at the site in 1894; in 1997 investigations were resumed by the Swedish Institute at Athens. Although there are traces of occupancy in the area by the early Bronze Age, the results so far attest to some activity in the very late Bronze Age (ca. 1100 BC); with a considerable proportion of the remains dating from the eighth century BC and the visible remains dating to the sixth to second centuries BC.

A geophysical investigation was conducted at the site using both electrical resistance techniques and magnetic methods. A small area of 20 × 15 m at the southeast section of the site was surveyed with high‐resolution multiplexed electrical resistance techniques in order to maximize the information content of the subsurface remains in both horizontal and vertical extent.

The local vertical magnetic gradient of the Earth's magnetic field was measured using a fluxgate gradiometer, and multiplexed electrical resistance techniques were applied in order to map the subsoil resistance at different depths. In addition, the whole area was investigated with a double twin probe configuration.

Emphasis was given to the use of the multiplex electrical resistance technique with different configurations. A small grid to the southeast of the survey area was investigated with a twin probe configuration, recording the subsurface resistance at four increasing depths. Additionally, 0.5 m dipole–dipole and 0.5 m Wenner mapping configurations were performed. The above data were processed using a specifically developed processing package (GPP). The resistance instrument was also programmed in such a way as to conduct parallel resistance tomographies along the x and y directions with a pole–pole array. Copyright © 2005 John Wiley & Sons, Ltd.
Preparation, characterization, and properties of chitosan‐g‐poly(vinyl alcohol) copolymer
Authors: Huang Meifang , Fang Yue'e
Published: October 2005

The graft copolymer chitosan‐g‐poly(vinyl alcohol), with nontoxicity, biodegradability, and biocompatibility, was prepared by a novel method. The copolymer with porous net structure was observed by scanning electron microscopy (SEM). It is a potential method to combine chitosan with the synthetic polymers. The grafting reactions were conducted with various poly(vinyl alcohol) (PVA)/6‐O‐succinate‐N‐phthaloyl‐chitosan (PHCSSA) feed ratios to obtain chitosan‐g‐poly(vinyl alcohol) copolymers with various PVA contents. The chemical structure of the chitosan‐g‐poly(vinyl alcohol) was characterized by Fourier transform infrared and nuclear magnetic resonance (NMR) spectroscopy. Differential scanning calorimetry (DSC), X‐ray diffraction (XRD), and SEM were also detected to characterize the copolymer. © 2005 Wiley Periodicals, Inc. Biopolymers 81: 160–166, 2006

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
On‐line monitoring of CO2 production in Lactococcus lactis during physiological pH decrease using membrane inlet mass spectrometry with dynamic pH calibration
Authors: Andersen Ann Zahle , Lauritsen Frants Roager , Olsen Lars Folke
Published: October 2005

Monitoring CO2 production in systems, where pH is changing with time is hampered by the chemical behavior and pH‐dependent volatility of this compound. In this article, we present the first method where the concentration and production rate of dissolved CO2 can be monitored directly, continuously, and quantitatively under conditions where pH changes rapidly (≈2 units in 15 min). The method corrects membrane inlet mass spectrometry (MIMS) measurements of CO2 for pH dependency using on‐line pH analysis and an experimentally established calibration model. It is valid within the pH range of 3.5 to 7, despite pH‐dependent calibration constants that vary in a non‐linear fashion with more than a factor of 3 in this interval. The method made it possible to determine the carbon dioxide production during Lactococcus lactis fermentations, where pH drops up to 3 units during the fermentation. The accuracy was approximately 5%. We used the method to investigate the effect of initial extracellular pH on carbon dioxide production during anarobic glucose fermentation by non‐growing Lactocoocus lactis and demonstrated that the carbon dioxide production rate increases considerably, when the initial pH was increased from 6 to 6.8. © 2005 Wiley Periodicals, Inc.
Preparation of human metabolites of propranolol using laboratory‐evolved bacterial cytochromes P450
Authors: Otey Christopher R. , Bandara Geethani , Lalonde James , Takahashi Katsuyuki , Arnold Frances H.
Published: October 2005

Testing the toxicities and biological activities of the human metabolites of drugs is important for development of safe and effective pharmaceuticals. Producing these metabolites using human cytochrome P450s is difficult, however, because the human enzymes are costly, poorly stable, and slow. We have used directed evolution to generate variants of P450 BM3 from Bacillus megaterium that function via the “peroxide shunt” pathway, using hydrogen peroxide in place of the reductase domain, oxygen and NADPH. Here, we report further evolution of the P450 BM3 heme domain peroxygenase to enhance production of the authentic human metabolites of propranolol by this biocatalytic route. This system offers a versatile, cost‐effective, and scaleable route to the synthesis of drug metabolites. © 2005 Wiley Periodicals, Inc.
Feasibility of early emergency room notification to improve door‐to‐balloon times for patients with acute ST segment elevation myocardial infarction
Authors: Sekulic Milan , Hassunizadeh Bischan , McGraw Steve , David Shukri
Published: October 2005

An algorithm to lower time from first contact in the field by EMS personnel to in‐hospital mechanical reperfusion is described. ECG tracings were telemetered via cellular phone to an emergency room physician, who then activated the cardiac catheterization call team to bypass usual delays seen during ER triage. Seventy‐one ECGs were sent to the ER in the time interval from October 2003 to October 2004. Five ECGs (7.0%) failed to transmit due to failure of the cellular phone to receive an adequate signal. Sixty‐six patients (93.0%) had an adequate ECG transmitted to the ER and six patients with ST elevation myocardial infarction were identified. Door‐to‐balloon times were lowered to 44 ± 17.4 min, a substantial decrease over historical norms that range from 120 min (25th percentile) to 289 min (75th percentile). © 2005 Wiley‐Liss, Inc.
Encapsulation of Cyanometalates by a Tris‐macrocyclic Ligand Tricopper(II) Complex: Syntheses, Structural Variation, and Magnetic Exchange Coupling Pathways
Authors: Atanasov Mihail , Comba Peter , Lampeka Yaroslaw D. , Linti Gerald , Malcherek Thomas , Miletich Ronald , Prikhod'ko Alexander I. , Pritzkow Hans
Published: October 2005

The reaction of [M(CN)6]3− (M=Cr3+, Mn3+, Fe3+, Co3+) and [M(CN)8]4−/3− (M=Mo4+/5+, W4+/5+) with the trinuclear copper(II) complex of 1,3,5‐triazine‐2,4,6‐triyltris[3‐(1,3,5,8,12‐pentaazacyclotetradecane)] ([Cu3(L)]6+) leads to partially encapsulated cyanometalates. With hexacyanometalate(III) complexes, [Cu3(L)]6+ forms the isostructural host–guest complexes [{[Cu3(L)(OH2)2][M(CN)6]2}{M(CN)6}]⋅[M(CN)6]⋅30 H2O with one bridging, two partially encapsulated, and one isolated [M(CN)6]3− unit. The octacyanometalates of Mo4+/5+ and W4+/5+ are encapsulated by two tris‐macrocyclic host units. Due to the stability of the +IV oxidation state of Mo and W, only assemblies with [M(CN)8]4− were obtained. The Mo4+ and W4+ complexes were crystallized in two different structural forms: [{Cu3(L)(OH2)}2{Mo(CN)8}](NO3)8⋅15 H2O with a structural motif that involves isolated spherical [{Cu3(L)(OH2)}2{M(CN)8}]8+ ions and a “string‐of‐pearls” type of structure [{[Cu3(L)]2[M(CN)8]}{M(CN)8}](NO3)4⋅ 20 H2O, with [M(CN)8]4− ions that bridge the encapsulated octacyanometalates in a two‐dimensional network. The magnetic exchange coupling between the various paramagnetic centers is characterized by temperature‐dependent magnetic susceptibility and field‐dependent magnetization data. Exchange between the Cu⋅⋅⋅Cu pairs in the [Cu3(L)]6+ “ligand” is weakly antiferromagnetic. Ferromagnetic interactions are observed in the cyanometalate assemblies with Cr3+, exchange coupling of Mn3+ and Fe3+ is very small, and the octacoordinate Mo4+ and W4+ systems have a closed‐shell ground state.
Supramolecular Assembly of an Amphiphilic GdIIIChelate: Tuning the Reorientational Correlation Time and the Water Exchange Rate
Authors: Torres Susana , Martins José A. , André João P. , Geraldes Carlos F. G. C. , Merbach André E. , Tóth Éva
Published: October 2005

We report the synthesis and characterization of the novel ligand H5EPTPA‐C16((hydroxymethylhexadecanoyl ester)ethylenepropylenetriaminepentaacetic acid). This ligand was designed to chelate the GdIIIion in a kinetically and thermodynamically stable way while ensuring an increased water exchange rate (kex) on the GdIIIcomplex owing to steric compression around the water‐binding site. The attachment of a palmitic ester unit to the pendant hydroxymethyl group on the ethylenediamine bridge yields an amphiphilic conjugate that forms micelles with a long tumbling time (τR) in aqueous solution. The critical micelle concentration (cmc = 0.34 mM) of the amphiphilic [Gd(eptpa‐C16)(H2O)]2−chelate was determined by variable‐concentration proton relaxivity measurements. A global analysis of the data obtained in variable‐temperature and multiple‐field17O NMR and1H NMRD measurements allowed for the determination of parameters governing relaxivity for [Gd(eptpa‐C16)(H2O)]2−; this is the first time that paramagnetic micelles with optimized water exchange have been investigated. The water exchange rate was found to be${k{{\,298\hfill \atop {\rm ex}\hfill}}}$= 1.7×108s−1, very similar to that previously reported for the nitrobenzyl derivative [Gd(eptpa‐bz‐NO2)(H2O)]2−(${k{{\,298\hfill \atop {\rm ex}\hfill}}}$= 1.5×108s−1). The rotational dynamics of the micelles were analysed by using the Lipari–Szabo approach. The micelles formed in aqueous solution show considerable flexibility, with a local rotational correlation time of${\tau {{\,298\hfill \atop {\rm l0}\hfill}}}$= 330 ps for the GdIIIsegments, which is much shorter than the global rotational correlation time of the supramolecular aggregates,${\tau {{298\hfill \atop {\rm g0}\hfill}}}$= 2100 ps. This internal flexibility of the micelles is responsible for the limited increase of the proton relaxivity observed on micelle formation (r1= 22.59 mM−1 s−1for the micelles versus 9.11 mM−1 s−1for the monomer chelate (20 MHz; 25 °C)).
Lipase Active‐Site‐Directed Anchoring of Organometallics: Metallopincer/Protein Hybrids
Authors: Kruithof Cornelis A. , Casado Miguel A. , Guillena Gabriela , Egmond Maarten R. , van der Kerk‐van Hoof Anca , Heck Albert J. R. , Klein Gebbink Robertus J. M. , van Koten Gerard
Published: October 2005

The work described herein presents a strategy for the regioselective introduction of organometallic complexes into the active site of the lipase cutinase. Nitrophenol phosphonate esters, well known for their lipase inhibitory activity, are used as anchor functionalities and were found to be ideal tools to develop a single‐site‐directed immobilization method. A small series of phosphonate esters, covalently attached to ECE “pincer”‐type d8‐metal complexes through a propyl tether (ECE=[C6H3(CH2E)2‐2,6]−; E=NR2 or SR), were designed and synthesized. Cutinase was treated with these organometallic phosphonate esters and the new metal‐complex/protein hybrids were identified as containing exactly one organometallic unit per protein. The organometallic proteins were purified by membrane dialysis and analyzed by ESI‐mass spectrometry. The major advantages of this strategy are: 1) one transition metal can be introduced regioselectively and, hence, the metal environment can potentially be fine‐tuned; 2) purification procedures are facile due to the use of pre‐synthesized metal complexes; and, most importantly, 3) the covalent attachment of robust organometallic pincer complexes to an enzyme is achieved, which will prevent metal leaching from these hybrids. The approach presented herein can be regarded as a tool in the development of regio‐ and enantioselective catalyst as well as analytical probes for studying enzyme properties (e.g., structure) and, hence, is a “proof‐of‐principle design” study in enzyme chemistry.
Transition‐Metal‐Catalyzed Sequential Cross‐Coupling of Bis(iodozincio)methane and ‐ethane with Two Different Organic Halides
Authors: Yoshino Hideaki , Toda Narihiro , Kobata Masami , Ukai Katsumi , Oshima Koichiro , Utimoto Kiitiro , Matsubara Seijiro
Published: October 2005

Bis(iodozincio)methane, prepared from diiodomethane and zinc, reacts with an organic halide in the presence of a transition‐metal catalyst to give an iodozinciomethylenated compound; this then reacts with another organic halide to form a CC bond. The overall process connects two electrophiles with one carbon atom. Bis(iodozincio)ethane can also undergo this transformation, yielding a new stereogenic center. The asymmetric induction of this stereogenic center was investigated by using a chiral palladium catalyst.
A Close Look at Fluorescence Quenching of Organic Dyes by Tryptophan
Authors: Doose Sören , Neuweiler Hannes , Sauer Markus
Published: October 2005

Understanding fluorescence quenching processes of organic dyes by biomolecular compounds is of fundamental importance for in‐vitro and in‐vivo fluorescence studies. It has been reported that the excited singlet state of some oxazine and rhodamine derivatives is efficiently and almost exclusively quenched by the amino acid tryptophan (Trp) and the DNA base guanine via photoinduced electron transfer (PET). We present a detailed analysis of the quenching interactions between the oxazine dye MR121 and Trp in aqueous buffer. Steady‐state and time‐resolved fluorescence spectroscopy, together with fluorescence correlation spectroscopy (FCS), reveal three contributing quenching mechanisms: 1) diffusion‐limited dynamic quenching with a bimolecular quenching rate constant kd of 4.0×109 s−1 M−1, 2) static quenching with a bimolecular association constant Ks of 61 M−1, and 3) a sphere‐of‐action contribution to static quenching described by an exponential factor with a quenching constant λ of 22 M−1. The latter two are characterized as nonfluorescent complexes, formed with ≈30 % efficiency upon encounter, that are stable for tens of nanoseconds. The measured binding energy of 20–30 kJmol−1 is consistent with previous estimates from molecular dynamics simulations that proposed stacked complexes due to hydrophobic forces. We further evaluate the influence of glycerol and denaturant (guanidine hydrochloride) on the formation and stability of quenched complexes. Comparative measurements performed with two other dyes, ATTO 655 and Rhodamine 6G show similar results and thus demonstrate the general applicability of utilizing PET between organic dyes and Trp for the study of conformational dynamics of biopolymers on sub‐nanometer length and nanosecond time‐scales.
Tuning of the α‐Terthiophene Radical Cation Coupling Reaction Using Mixed Micelles with Varying Charge Density
Authors: van Stam Jan , Viaene Lucien , Evans Christopher H.
Published: October 2005

The photophysics and photochemistry of α‐terthiophene (αT), compartmentalized in mixed nonionic/anionic micelles, have been investigated with focus on the influence of the micellar surface charge density on the formation of the radical coupling product α‐hexathiophene (αH). By varying the ratio of nonionic‐to‐anionic surfactants, and assuming ideal mixing, the charge density of the mixed micelles was varied. From Poisson–Boltzmann calculations, performed using the cell model, the electrostatic potential and the counterion activity were estimated as a function of the distance from the micellar surface. Upon excitation, the triplet state of αT is formed, from which the αT radical cation can be formed by absorption of a second photon. The radical cation can form αH if it encounters another αT radical cation. Under the experimental conditions used, this implies that the αH formation only occurs if the compartmentalized radical cation is able to migrate from its host micelle to another micelle, either via the surrounding bulk or by fusion of two micelles followed by mixing of their contents before micellar fission. The formation yield of the radical cation depends on the charge density of the mixed micelle; a lower charge density, that is, an increased amount of nonionic surfactant, lowers the yield. The yield of the coupling product αH, however, does not follow the same trend. A maximum yield of αH is found at intermediate nonionic surfactant molar ratios. This behavior is understood in terms of the Poisson–Boltzmann simulation results and by comparing charge‐density changes as a function of molar fraction with the changes in counterion activity. The αH yield is a result of the balance between an increased possibility of radical cation bulk migration and a lowered electrostatic stabilization of the radical.
Novel Highly Substituted Biraryl Ethers, Phomosines D–G, Isolated from the Endophytic Fungus Phomopsis sp. from Adenocarpus foliolosus
Authors: Dai Jingqiu , Krohn Karsten , Flörke Ulrich , Gehle Dietmar , Aust Hans‐Jürgen , Draeger Siegfried , Schulz Barbara , Rheinheimer Joachim
Published: October 2005

Six new metabolites, phomosines D–G (4–7), 6‐hydroxy‐6‐isopropylcyclohex‐1‐enecarboxylic acid (8) and(1aS,3R,4R,4aR,6S,7R,8aS)‐7‐chloro‐3,6‐dihydroxy‐3,4a,8,8‐tetramethyl‐octahydro‐1aH‐naphtho[1‐b]oxirene‐4‐carboxylic acid (9) were isolated together with seven known compounds (1–3, 10–13) from the endophytic fungus Phomopsis sp. The structures of 1–13 were determined by spectroscopic methods (mainly extensive 1D and 2D NMR experiments and by mass spectrometric measurements). The antibacterial, fungicidal, and herbicidal properties of the new compounds were evaluated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Natural Product‐Guided Synthesis of a Spiroacetal Collection Reveals Modulators of Tubulin Cytoskeleton Integrity
Authors: Barun Okram , Kumar Kamal , Sommer Stefan , Langerak Anette , Mayer Thomas U. , Müller Oliver , Waldmann Herbert
Published: October 2005

The spiro[5.5]ketal moiety forms the underlying structural skeleton of numerous biologically active natural products. Since simplified but characteristic spiroketals derived from the parent natural products retain biological activity, the spiro[5.5]ketal unit can be regarded as a biologically prevalidated framework for the development of natural product‐derived compound collections. We report an enantioselective synthesis of spiro[5.5]ketals on solid support. The reaction sequence employs asymmetric boron enolate aldol reactions with the enolate bound to the polymer or in solution as the key enantiodifferentiating step. It proceeds in up to 12 steps on solid support, makes the desired spiroketals available in high overall yields and with high stereoselectivities and is amenable to structural variation of the products. The small spiroketal collection synthesized contains phosphatase inhibitors and compounds that modulate the formation of the tubulin cytoskeleton in human cancer cells without directly targeting microtubules. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Multiple Logical Access with a Single Fluorophore–Spacer–Receptor System: Realization of Inhibit (INH) Logic Function
Authors: Banthia Sandip , Samanta Anunay
Published: October 2005

A new fluorescent PET sensor (1) has been synthesized, the fluorescence of which switches “On” with a blue‐to‐green color change in the presence of Zn2+, Cd2+, or Pb2+ (OR logic). X‐ray structure analyses of 1 and its Zn2+ complex reveal that the solid‐state conformation is in accordance with the results observed in solution. Sensor 1 also acts as an “Off‐On‐Off” switch stimulated by protons. The H+‐driven “Off‐On‐Off” switch is integrated with a Zn2+‐, Cd2+‐, or Pb2+‐induced OR logic gate to construct a first INH logic gate employing these ionic inputs. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Urokinase‐immobilization suppresses inflammatory responses to polyurethane tubes implanted in rabbit muscles
Authors: Lai Zhong‐Fang , Imamura Takahisa , Koike Norio , Kitamoto Yasunori
Published: October 2005

Urokinase and plasmin appear to have antiinflammatory activity in some injury models, and urokinase immobilization has been clinically used to prevent thrombus formation in various implants, including intravenous indwelling catheters and subcutaneous drainage tubes. In the present study, polyurethane tubes were embedded in rabbit muscle for 3 months and the effect of urokinase immobilization on inflammatory responses to the implanted tubes was studied at 1 week, 1 month, and 3 months. Mononuclear leukocyte accumulation occurred around implanted polyurethane tubes and peaked after 1 month, but was reduced significantly by urokinase immobilization. The treatment also lessened as well as delayed eosinophil accumulation, but did not affect fibrosis caused by implanted tubes. These results indicate suppressive effects of urokinase immobilization on polyurethane‐elicited inflammatory responses and suggest that an approach to develop persistently active urokinase immobilization is rational for successful long‐term device implantation. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Expression of morphogenic genes in mature ovarian and testicular tissues: Potential stem‐cell niche markers and patterning factors
Authors: von Schalburg Kristian R. , McCarthy Sean P. , Rise Matthew L. , Hutson James C. , Davidson William S. , Koop Ben F.
Published: October 2005

Morphogens are developmental regulators that modulate different tissue patterning, proliferation, differentiation, or remodeling processes in embryonic and adult tissues. Morphogens may also evoke specific regulatory programs in stem cells. Some of the morphogens involved in these processes have been characterized, while others remain unidentified. A microarray containing 3,557 salmonid cDNAs was used to compare the transcriptomes of rainbow trout precocious ovary at three different stages during second year (June, August, and October) with a reference (June normal ovary) transcriptome. During this study, we detected morphogen transcript hybridizations to salmonid elements and the study was enlarged to investigate these activities in various developmental stages of both ovary and testis. Genes from diverse development regulator families such as Anterior gradient‐2, BMP, Epimorphin, Flightless, Frizzled, Notch, Tiarin, Twisted gastrulation, and Wnt were demonstrated to be expressed in the adult trout gonads. In mice or rats, expression of mammalian bmp‐4, epimorphin, flightless, twisted gastrulation, and GW112 transcripts were localized to cell types isolated from the developed ovary and testis. Comparisons of salmonid and mammalian morphogens at the amino acid residue level show high similarities, suggesting functional conservation. This report provides evidence for local regulation by various morphogens and their potential to control distinct programs of gene expression in the gametes and their accessory cells during gametogenesis. Mol. Reprod. Dev. © 2005 Wiley‐Liss, Inc.
Crosslinking study of mixtures of DGEBA and 1,3‐dioxan‐2‐one catalyzed by lanthanide triflates
Authors: Cervellera Roser , Ramis Xavier , Salla Josep Maria , Mantecón Ana , Serra Angels
Published: October 2005

Ytterbium and lanthanum triflates were used as catalysts to cure diglycidylether of bisphenol A with different proportions of 1,3‐dioxan‐2‐one. The curing was studied by differential scanning calorimetry (DSC) and Fourier transform infrared in the attenuated‐total‐reflection mode (FTIR/ATR). FTIR/ATR was used to monitor the competitive reactive processes and to quantify the evolution of the groups involved in the curing process. We observed the formation of a five‐membered cyclic carbonate that remains unreacted at the chain ends, because of an equilibrium process between the spiroorthocarbonates that had formed as intermediate species. The kinetics were studied by DSC experiments and analyzed with isoconversional procedures. The system catalyzed by ytterbium triflate had a higher curing rate. Thermogravimetric analysis and dynamic mechanical thermal analysis experiments were used to evaluate the properties of the materials obtained. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5799–5813, 2005
New asymmetric vanadium catalyst for highly selective oxidative coupling polymerization
Authors: Habaue Shigeki , Murakami Soichiro , Higashimura Hideyuki
Published: October 2005

Novel oxovanadium(IV)–bisoxazoline catalysts, such as vanadyl sulfate (VOSO4)–(R)‐2,2′‐isopropylidenebis(4‐phenyl‐2‐oxazoline) [(R)Phbox], for the asymmetric oxidative coupling polymerization (AOCP) of 2,3‐dihydroxynaphthalene were developed. For example, the AOCP with VOSO4–(R)Phbox in CH2Cl2–MeOH [7/1 (v/v)] at room temperature for 24 h under an O2 atmosphere, followed by acetylation of the hydroxyl groups, afforded a polymer in a 58% yield with a specific rotation of [α]D = −147. The enantioselectivity during the polymerization was estimated to be 80% enantiomeric excess (S), a value much higher than that observed for the polymerizations with the copper(I)‐based catalyst systems and the typical oxovanadium(IV) catalysts reported for the asymmetric oxidative coupling producing the 1,1′‐bi‐2‐naphthol derivatives. © 2005 Wiley Periodicals, Inc., Inc. J Polym Sci Part A: Polym Chem 43: 5872–5878, 2005
Efficient route to well‐characterized homo, block, and statistical polymers containing terpyridine in the side chain
Authors: Shunmugam Raja , Tew Gregory N.
Published: October 2005

The incorporation of metal–ligand interactions into macromolecules imparts to them unique and potentially useful properties. We report the synthesis of homo, block, and statistical copolymers with controlled molecular weights, compositions, and relatively narrow polydispersities via atom transfer radical polymerization that contain activated esters for the subsequent incorporation of terpyridine. This approach is universal and allows facile access to macromolecules with rich chemical functions, illustrated here with metal ligands. Comonomers include methyl, n‐butyl, and poly(ethylene glycol) methyl ether methacrylate as well as styrene. The addition of lanthanide ions to the final copolymers generates emissive materials with blue, green, red, or purple light, depending on the metal used. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5831–5843, 2005