bluuebunny/crossref_metadata_2025 huggingface dataset:
Cyclin‐dependent kinase inhibition limits glomerulonephritis and extends lifespan of mice with systemic lupus
Authors: Zoja Carla , Casiraghi Federica , Conti Sara , Corna Daniela , Rottoli Daniela , Cavinato Regiane A. , Remuzzi Giuseppe , Benigni Ariela
Published: April 2007

Objective

To examine whether the cyclin‐dependent kinase (CDK) inhibitor seliciclib ameliorates autoimmune nephritis in (NZB × NZW)F1 mice.

Methods

In experiment 1, NZB × NZW mice received seliciclib (100 mg/kg or 200 mg/kg) or vehicle by gavage, beginning at age 2 months and ending at 8 months of age. In experiment 2, seliciclib (200 mg/kg) was administered alone or combined with low‐dose methylprednisolone, starting at age 5 months, when immune complex deposition in the kidney had already occurred. Animals were followed up until all vehicle‐treated mice died. In 2 additional groups of NZB × NZW mice treated with seliciclib or vehicle from 2 months of age until 5 months of age, splenocytes were isolated and tested ex vivo for T cell and B cell activity.

Results

Seliciclib, given at an early phase of disease, prolonged survival, delayed the onset of proteinuria and renal function impairment, and protected the kidney against glomerular hypercellularity, tubulointerstitial damage, and inflammation. Combining seliciclib with low‐dose methylprednisolone in mice with established disease extended the lifespan and limited proteinuria and renal damage more than treatment with either agent alone. Seliciclib limited immunologic signs of disease, reducing glomerular IgG and C3 deposits and levels of serum anti‐DNA antibodies. Moreover, it inhibited ex vivo T cell and B cell proliferative responses to polyclonal stimuli. T cell production of interferon‐γ and interleukin‐10 and B cell release of IgG2a were reduced by treatment with seliciclib.

Conclusion

These findings suggest that CDK activity may be a useful target in the treatment of systemic lupus erythematosus. A direct immunomodulatory action of seliciclib on T cells and B cells may be one of the mechanisms underlying the beneficial effects.
Cultivation of Tropheryma whipplei from the synovial fluid in Whipple's arthritis
Authors: Puéchal Xavier , Fenollar Florence , Raoult Didier
Published: April 2007

This report describes a patient who presented with fever, weight loss, diarrhea, and adenopathy. At the time of presentation he had a 28‐year history of unusually severe destructive polyarthritis. Duodenal biopsy revealed periodic acid–Schiff–positive macrophages. Polymerase chain reaction studies showed positivity for Tropheryma whipplei in synovial fluid, synovial tissue, and lymph node specimens, and Whipple's disease was diagnosed. T whipplei was successfully cultivated from the synovial fluid by both cell culture and axenic culture. This strain (named ART1) was subcultured and subsequently established and genotyped. Antibiotic treatment was instituted in the patient, after which his symptoms remitted. These findings show for the first time that Whipple's arthritis may be, at least in some cases, a septic arthritis.
BAFF‐modulated repopulation of B lymphocytes in the blood and salivary glands of RITUXIMAB‐TREATED patients with Sjögren's syndrome
Authors: Pers Jacques‐Olivier , Devauchelle Valérie , Daridon Capucine , Bendaoud Boutahar , Berre Rozenn Le , Bordron Anne , Hutin Pascal , Renaudineau Yves , Dueymes Maryvonne , Loisel Séverine , Berthou Christian , Saraux Alain , Youinou Pierre
Published: April 2007

Objective

Treatment with rituximab depletes B cells from the peripheral blood (PB) and salivary glands (SGs) of patients with primary Sjögren's syndrome (SS). The purpose of this study was to track the repopulation of B cell subsets in PB as well as their subsequent homing into SGs in patients with primary SS treated with rituximab.

Methods

A series of 4‐color flow cytometry experiments delineated B cell subsets in 15 patients with primary SS. All were tested on days 8 and 15 of treatment. Nine of the patients were followed up monthly for 10 months, and the remaining 6 patients were followed up monthly for 24 months. Enzyme‐linked immunosorbent assays were developed to measure serum levels of BAFF and rituximab. SGs were biopsied at the start of the study and 4 months after treatment in 15 patients, 12 months after treatment in 3 patients, and 24 months after treatment in 2 patients.

Results

Baseline serum levels of BAFF correlated inversely (r = −0.92, P < 5 × 10−4) with the duration of B cell depletion: the higher the BAFF levels, the shorter the duration of B cell depletion. Four B cell subsets repopulated the PB: plasmablasts (CD19+, CD5−,IgD−,CD38++), transitional type 1 (T1) B cells (CD19+,CD5+,IgD+,CD38++), mature Bm2 cells (CD19+,CD5+/−,IgD+,CD38+/−), and memory B cells (CD19+,CD5−,IgD−,CD38−). Increased numbers of Bm2 cells and decreased memory B cells reappeared with time. Sequential SG biopsies revealed that B cells were absent in these glands for 12 months: they were detected 24 months after rituximab treatment. Memory and T1 B cells were the first B cells identified locally.

Conclusion

The timing of B cell repopulation is modulated by BAFF and is followed by reconstitution of the preexisting abnormalities.
Duodenal atresia in an infant with triple‐X syndrome: A new associated malformation in 47,XXX
Authors: Rolle Udo , Linse Barbara , Glasow Simone , Sandig Klaus Rainer , Richter Thomas , Till Holger
Published: April 2007

BACKGROUND: An association between the triple‐X syndrome (47,XXX) and gastrointestinal malformations is extremely rare. Most 47,XXX patients present with a normal phenotype, but genitourinary malformations have been described. CASE: We report a case of a child with 47,XXX and duodenal atresia. Antenatal ultrasound scan showed a dilated fetal stomach and upper part of the duodenum (double bubble phenomenon) at 31 weeks of gestation in a 31‐year‐old woman with polyhydramnion. The amniotic fluid karyotype showed 47,XXX. After a scheduled delivery, duodenal atresia was confirmed and treated with duodeno‐duodenostomy. CONCLUSIONS: The possible association of gastrointestinal and genitourinary tract anomalies requires a detailed postnatal clinical investigation and ultrasonographic examination of the abdomen, retroperitoneum, and pelvis on all triple‐X syndrome patients. Birth Defects Research (Part A) 2007. © 2007 Wiley‐Liss, Inc.
Bemessungshilfen und Konstruktion bei geneigten Querkräften
Authors: Mark Peter , Birtel Veit , Stangenberg Friedhelm
Published: April 2007

Dargestellt wird das praktische Vorgehen der Querkraftbemessung bei geneigt zu den Querschnittshauptachsen angreifenden Querkräften (zweiachsige Querkraft). Dazu werden für Stahlbetonträger mit Rechteckquerschnitt die Widerstandsgleichungen für Zug‐ und Druckstrebentragfähigkeiten auf Grundlage von DIN 1045‐1 und EC 2 abgeleitet, verifiziert und in Bemessungsdiagrammen aufgearbeitet. Ein Beispiel zeigt die einfache Ermittlung erforderlicher Bügelbewehrungsmengen mit gleichzeitigem Nachweis der Druckstrebentragfähigkeit. Die konstruktiven Regeln für Bügelverankerungen und das Versatzmaß lassen sich bei Beachtung der räumlichen Neigung des Querkraftfachwerks und der verdrehten Nulllinienlage direkt auf Situationen geneigter Querkraftwirkungen übertragen.
Ettringit‐ und Thaumasittreiben in Betonwerkstoffen: Analytische Betrachtung und Ursachenermittlung mittels Röntgendiffraktometrie und Rasterelektronenmikroskopie
Authors: Göske Jürgen , Pöllmann Herbert , Wenda Richard
Published: April 2007

Seit einigen Jahren werden vermehrt Bauschäden an Betonbauwerken beobachtet, die auf Treiberscheinungen infolge von Ettringit‐ und Thaumasit‐ Kristallisation rückzuführen sind. Die Ursachen hierfür sind meistens mineralische Treiberscheinungen. Als Maßnahme gegen derartige Angriffe werden sulfatbeständige Zemente eingesetzt, die sich durch besonders niedrigen C3A‐Gehalt auszeichnen (d. h. entsprechend wenig Aluminat für die Ettringit‐Bildung enthalten). Trotzdem kam es in letzter Zeit zu Langzeitschäden an Betonbauwerken durch Sulfatangriff, die auf Thaumasit‐Bildung zurückgeführt werden. Mit Hilfe von Röntgendiffraktometrie, Rasterelektronenmikroskopie und energiedispersiver Röntgenspektroskopie konnten an prädestinierten Schadensfällen die hierfür ursächlichen mineralischen Phasen zweifelsfrei analysiert, identifiziert und in den Betonwerkstücken lokalisiert werden.
Elucidation of the mechanism and end products of glutaraldehyde crosslinking reaction by X‐ray structure analysis
Authors: Wine Yariv , Cohen‐Hadar Noa , Freeman Amihay , Frolow Felix
Published: April 2007

Glutaraldehyde has been used for several decades as an effective crosslinking agent for many applications including sample fixation for microscopy, enzyme and cell immobilization, and stabilization of protein crystals. Despite of its common use as a crosslinking agent, the mechanism and chemistry involved in glutaraldehyde crosslinking reaction is not yet fully understood. Here we describe feasibility study and results obtained from a new approach to investigate the process of protein crystals stabilization by glutaraldehyde crosslinking. It involves exposure of a model protein crystal (Lysozyme) to glutaraldehyde in alkaline or acidic pH for different incubation periods and reaction arrest by medium exchange with crystallization medium to remove unbound glutaraldehyde. The crystals were subsequently incubated in diluted buffer affecting dissolution of un‐crosslinked crystals. Samples from the resulting solution were subjected to protein composition analysis by gel electrophoresis and mass spectroscopy while crosslinked, dissolution resistant crystals were subjected to high resolution X‐ray structural analysis. Data from gel electrophoresis indicated that the crosslinking process starts at specific preferable crosslinking site by lysozyme dimer formation, for both acidic and alkaline pH values. These dimer formations were followed by trimer and tetramer formations leading eventually to dissolution resistant crystals. The crosslinking initiation site and the end products obtained from glutaraldehyde crosslinking in both pH ranges resulted from reactions between lysine residues of neighboring protein molecules and the polymeric form of glutaraldehyde. Reaction rate was much faster at alkaline pH. Different reaction end products, indicating different reaction mechanisms, were identified for crosslinking taking place under alkaline or acidic conditions. Biotechnol. Bioeng. 2007;98:711–718. © 2007 Wiley Periodicals, Inc.
Proteome analysis of antibody‐producing CHO cell lines with different metabolic profiles
Authors: Pascoe Deborah E. , Arnott David , Papoutsakis Eleftherios T. , Miller William M. , Andersen Dana C.
Published: April 2007

Two‐dimensional gel electrophoresis and tandem mass spectrometry were used to identify proteins associated with a metabolic shift during fed‐batch cultures of two recombinant antibody‐producing CHO cell lines. The first cell line underwent a marked change in lactate metabolism during culture, initially producing lactate and then consuming it, while the second cell line produced lactate for a similar duration but did not later consume it. The first cell line displayed a declining specific antibody productivity during culture, correlating to the 2‐D gel results and the intracellular antibody concentration determined by HPLC. Several statistical analysis methods were compared during this work, including a fixed fold‐change criterion and t‐tests using standard deviations determined in several ways from the raw data and mathematically transformed data. Application of a variance‐stabilizing transformation enabled the use of a global empirical standard deviation in the t‐tests. Most of the protein spots changing in each cell line did not change significantly in the other cell line. A substantial fraction of the changing proteins were glycolytic enzymes; others included proteins related to antibody production, protein processing, and cell structure. Enolase, pyruvate kinase, BiP/GRP78, and protein disulfide isomerase were found in spots that changed over time in both cell lines, and some protein changes differed from previous reports. These data provide a foundation for future investigation of metabolism in industrially relevant mammalian cell culture processes, and suggest that along with differences between cell types, the proteins expressed in cultures with low lactate concentrations may depend on how those conditions were generated. Biotechnol. Bioeng. 2007;98: 391–410. © 2007 Wiley Periodicals, Inc.
A genetic time‐delay circuitry in mammalian cells
Authors: Weber Wilfried , Kramer Beat P. , Fussenegger Martin
Published: April 2007

Gene expression circuitries with time‐delayed expression profiles regulate key events, such as oscillating systems, noise elimination, and coordinated multi‐step processes, in all organisms from bacteria to mammalian cells. We present the rational synthesis of a genetic circuit displaying time‐delayed expression in silico and in mammalian cells. The network is based on a time‐delay circuit, where the tetracycline‐responsive transactivator (tTA) induces expression of the pristinamycin‐responsive repressor PIP‐KRAB, which silences expression of the terminal human placental secreted alkaline phosphatase (SEAP). While the addition of pristinamycin I inactivates PIP‐KRAB and results in the immediate resumption of SEAP expression, addition of tetracycline abolishes PIP‐KRAB synthesis. Consequently, SEAP production remains repressed until the PIP‐KRAB buffer in the cell is eliminated. We characterized in silico and in vivo the time‐delayed expression properties and analyzed the impact of the size and stability of the PIP‐KRAB buffer on fine‐tuning of the response kinetics. This tunable time‐delay circuitry represents a biologic building block for emulating a fundamental circuit topology in integrated artificial synthetic gene networks for the design of tailor‐made cell types and organisms. Biotechnol. Bioeng. 2007;98: 894–902. © 2007 Wiley Periodicals, Inc.
Effect of moderate electric field on the metabolic activity and growth kinetics of Lactobacillus acidophilus
Authors: Loghavi L. , Sastry S.K. , Yousef A.E.
Published: April 2007

Moderate electric fields (MEF), applied across microbial growth media may potentially affect the permeability of cell membranes. We investigated the effects of MEF on bacteriocin (lacidin A) production during fermentation and on microbial growth kinetics of Lactobacillus acidophilus OSU 133. We comparatively investigated the following treatments: conventional, MEF (1 V/cm, 60 Hz, for 40 h), combinations of MEF (1 V/cm, 60 Hz, for the first 5 h) and conventional fermentation (for 35 h), and discrete MEF (1 V/cm, 2 min on and off, for 40 h). In all treatments, except as noted below, temperature was set at 30°C. The two exceptions were control (conventional) and discrete MEF treatment, which were conducted both at 30 and 37°C. MEF treatments at the early stage of fermentation at 30°C showed the maximum bacteriocin activity. Minimum bacteriocin production was observed under conventional fermentation at 37°C. A mathematical model based on Monod growth kinetics was used to predict bacteriocin production and showed results consistent with conventional treatment data. MEF did not have a significant effect on the lag time, maximum specific growth rate, biomass production and pH change under the different experimental conditions at each specific temperature. Based on the observations, bacteriocin activity under the presence of MEF at the early stage of fermentation increased without significant change in the final biomass. Biotechnol. Bioeng. 2007; 98: 872–881. © 2007 Wiley Periodicals, Inc.
Size comparison between proteins PEGylated with branched and linear poly(ethylene glycol) molecules
Authors: Fee Conan J.
Published: April 2007

Therapeutic proteins conjugated with branched poly(ethylene glycol) (PEG) have extended in vivo circulation half‐lives compared to linear PEG‐proteins, thought to be due partly to a greater hydrodynamic volume of branched PEG‐proteins, which reduces the glomerular sieving coefficient. In this paper, viscosity radii of PEGylated α‐lactalbumin (Mr = 14.2 kDa) and bovine serum albumin (Mr = 67 kDa) prepared with linear and branched PEGs (with nominal molecular weights 5, 10, 20 and 40 kDa) were compared experimentally using size exclusion chromatography (SEC). PEG adduct:protein molecular weight ratios of the PEGylated proteins covered the range 1:12 to 6:1. Direct comparisons of experimentally measured viscosity radii were found to be misleading due to differences between actual and nominal molecular weights of the PEG reagents used. Comparison with predicted viscosity radii shows that there is no significant difference between the viscosity radii of branched and linear PEG‐proteins having the same total molecular weight of PEG adducts. Therefore, longer in vivo circulation half‐lives of branched PEG‐proteins compared to linear PEG‐proteins are not explained by size difference. It is also calculated that the molecular size cut‐off for glomerular filtration, 60 Å for a 30 kDa PEG, matches the 30–50 Å size range for the pores of the glomerular basement membrane. Finally, it is confirmed that prediction of PEG‐protein viscosity radii should be based upon conservation of the total PEG adduct surface area to volume ratio for both linear and branched PEG‐proteins regardless of PEGylation extent. Biotechnol. Bioeng. 2007;98: 725–731. © 2007 Wiley Periodicals, Inc.
A novel solid–liquid two‐phase partitioning bioreactor for the enhanced bioproduction of 3‐methylcatechol
Authors: Prpich George P. , Daugulis Andrew J.
Published: April 2007

The bioproduction of 3‐methylcatechol from toluene via Pseudomonas putida MC2 was performed in a solid–liquid two‐phase partitioning bioreactor with the intent of increasing yield and productivity over a single‐phase system. The solid phase consisted of HYTREL™, a thermoplastic polymer that was shown to possess superior affinity for the inhibitory 3‐methylcatechol compared to other candidate polymers as well as a number of immiscible organic solvents. Operation of a solid–liquid biotransformation utilizing a 10% (w/w) solid (polymer beads) to liquid phase ratio resulted in the bioproduction of 3‐methylcatechol at a rate of 350 mg/L‐h, which compares favorably to the single phase productivity of 128 mg/L‐h. . HYTREL™ polymer beads were also reconstituted into polymer sheets, which were placed around the interior circumference of the bioreactor and successfully removed 3‐methylcatechol from solution resulting in a rate of 3‐methylcatechol production of 343 mg/L‐h. Finally, a continuous biotransformation was performed in which culture medium was circulated upwards through an external extraction column containing HYTREL™ beads. The design maintained sub lethal concentrations of 3‐methylcatechol within the bioreactor by absorbing produced 3‐methylcatechol into the polymer beads. As 3‐methylcatechol concentrations in the aqueous phase approached 500 mg/L the extraction column was replaced (twice) with a fresh column and the process was continued representing a simple and effective approach for the continuous bioproduction of 3‐methylcatechol. Recovery of 3‐methylcatechol from HYTREL™ was also achieved by bead desorption into methanol. Biotechnol. Bioeng. 2007; 98: 1008–1016. © 2007 Wiley Periodicals, Inc.
Peptide Derivatized Lamellar Aggregates as Target‐Specific MRI Contrast Agents
Authors: Tesauro Diego , Accardo Antonella , Gianolio Eliana , Paduano Luigi , Teixeira José , Schillén Karin , Aime Silvio , Morelli Giancarlo
Published: April 2007

The relaxivity behaviour and the structural characterization of new supramolecular aggregates (bilayer structures and micelles) obtained by combining two different amphiphilic monomers are reported. One monomer, (C18)2DTPAGlu‐Gd, contains a very stable gadolinium complex, and the other, DSPE‐PEG2000‐CCK8, contains the bioactive CCK8 peptide. Samples that contained only DSPE‐PEG2000‐CCK8, or up to 50 % (C18)2DTPAGlu‐Gd, aggregated as double‐layer structures (lamellar aggregates) with a thickness of∼80–100 Å, as evaluated by SANS measurement and Cryo‐TEM imaging. A transition to micelle formation was observed when the amount of (C18)2DTPAGlu‐Gd in the aggregate was increased. These were rod‐like micelles ∼40 Å in radius and >200 Å in length. The proton relaxivities for both lamellar aggregates and rod‐like micelles were the same (17.2 mM−1 s−1), although the values were the results of different combinations of local and global contributions. The in vitro target selectivity of aggregates that contained the CCK‐8 peptide was demonstrated by using nuclear medicine techniques.
Der Ölmarkt in Turbulenzen
Authors: Proidl H.
Published: April 2007

Das Jahr 2006 bestimmte aus energiewirtschaftlicher Sicht nachhaltig der hohe Ölpreis. Kein Superlativ wurde ausgelassen, um den Rohölpreis und seine Auswirkungen auf die Preise für Endenergieträger zu beschreiben. Zwar hat es in den vergangenen Wochen eine leichte Entspannung am internationalen Markt gegeben, doch der anstehende Winter und Förderkürzungen der OPEC ließen den Rohölpreis zuletzt wieder steigen. Der folgende Beitrag fasst einige zentrale Entwicklungen am Ölmarkt in der Vergangenheit zusammen, beleuchtet die Preise und wirft einen Blick in die Zukunft.
Transition‐State Energy and Position along the Reaction Coordinate in an Extended Activation Strain Model
Authors: de Jong G. Theodoor , Bickelhaupt F. Matthias
Published: April 2007

We investigate palladium‐induced activation of the CH, CC, CF, and CCl bonds in methane, ethane, cyclopropane, fluoromethane, and chloromethane, using relativistic density functional theory (DFT) at ZORA‐BLYP/TZ2P. Our purpose is to arrive at a qualitative understanding, based on accurate calculations, of the trends in activation barriers and transition state (TS) geometries (e.g. early or late along the reaction coordinate) in terms of the reactants’ properties. To this end, we extend the activation strain model (in which the activation energy ΔE≠ is decomposed into the activation strain ΔE≠strain of the reactants and the stabilizing TS interaction ΔE≠int between the reactants) from a single‐point analysis of the TS to an analysis along the reaction coordinate ζ, that is, ΔE(ζ)=ΔEstrain(ζ)+ΔEint(ζ). This extension enables us to understand qualitatively, trends in the position of the TS along ζ and, therefore, the values of the activation strain ΔE≠strain=ΔEstrain(ζTS) and TS interaction ΔE≠int=ΔEint(ζTS) and trends therein. An interesting insight that emerges is that the much higher barrier of metal‐mediated CC versus CH activation originates from steric shielding of the CC bond in ethane by CH bonds. Thus, before a favorable stabilizing interaction with the CC bond can occur, the CH bonds must be bent away, which causes the metal–substrate interaction ΔEint(ζ) in CC activation to lag behind. Such steric shielding is not present in the metal‐mediated activation of the CH bond, which is always accessible from the hydrogen side. Other phenomena that are addressed are anion assistance, competition between direct oxidative insertion (OxIn) versus the alternative SN2 pathway, and the effect of ring strain.
Joint packet scheduling and dynamic base station assignment for CDMA data networks
Authors: Makaya Christian , Aïssa Sonia
Published: April 2007

In current code division multiple access (CDMA) based wireless systems, a base station (BS) schedules packets independently of its neighbours, which may lead to resource wastage and the degradation of the system's performance. In wireless networks, in order to achieve an efficient packet scheduling, there are two conflicting performance metrics that have to be optimized: throughput and fairness. Their maximization is a key goal, particularly in next‐generation wireless networks. This paper proposes joint packet scheduling and BS assignment schemes for a cluster of interdependent neighbouring BSs in CDMA‐based wireless networks, in order to enhance the system performance through dynamic load balancing. The proposed schemes are based on sector subdivision in terms of average required resource per mobile station and utility function approach. The fairness is achieved by minimizing the variance of the delay for the remaining head‐of‐queue packets. Inter‐cell and intra‐cell interferences from scheduled packets are also minimized in order to increase the system capacity and performance. The simulation results show that our proposed schemes perform better than existing schemes available in the open literature. Copyright © 2007 John Wiley & Sons, Ltd.
Prognostic value of serum liver enzymes levels in type 2 diabetic patients
Authors: Monami Matteo , Balzi Daniela , Lamanna Caterina , Melani Cecilia , Cocca Carmen , Lotti Elena , Fedeli Angela , Masotti Giulio , Marchionni Niccolò , Mannucci Edoardo
Published: April 2007

Background

Elevated liver enzymes are associated with cardiovascular disease, while their relationship with cancer‐related mortality has not been assessed so far in diabetic patients.

Methods

An observational cohort study was performed on a consecutive series of 1952 type 2 diabetic patients. The association of liver enzymes with all‐cause and cause‐specific mortality was assessed. Information on all‐cause mortality was obtained by the City of Florence Registry Office.

Results

The average duration of follow‐up was 6.4 ± 2.7 years. Over that period, 362 deaths were recorded (26.9%), with a yearly mortality rate of 4.2%. Age‐ and sex‐adjusted HR of all‐cause mortality for gamma glutamyl‐transpeptidase (γ‐GT) γ‐GT > 40 U/l was 1.610 [1.245–2.082]. An increased cardiovascular mortality rate was observed in patients with elevation of γ‐GT, and γ‐GT and/or alanine aminotransferase (ALT), when compared with the rest of the sample (15.3 vs 10.8%, p < 0.05; and 15.2 vs 10.7%, p < 0.05, respectively). Similar results were observed when considering cancer‐related mortality.

The association of higher γ‐GT levels with all‐cause, cardiovascular, and cancer‐related mortality was confirmed at a multivariate analysis after adjustment for potential confounders.

Conclusions

The present study shows that, in type 2 diabetic patients, higher γ‐GT, but not ALT, is associated with increased mortality for cardiovascular disease and malignancies. Copyright © 2007 John Wiley & Sons, Ltd.
Carbon Ceramic Electrodes Modified with Laccase from Trametes hirsuta: Fabrication, Characterization and Their Use for Phenolic Compounds Detection
Authors: Haghighi Behzad , Rahmati‐Panah Amir , Shleev Sergey , Gorton Lo
Published: April 2007

Fungal laccase (Lc) from the basidiomycete Trametes hirsuta was immobilized on top of a carbon ceramic electrode using physical absorption. Direct, unmediated heterogeneous electron transfer between Lc and the carbon ceramic electrode (CCE) under aerobic conditions was shown. The bioelectrocatalytic reduction of oxygen on Lc‐CCE started at about 430 mV vs. Ag|AgCl|KClsat at pH 3.5 and moved with about 57 mV in the cathodic region per pH unit. The Lc‐modified CCE was then used as a biosensing detection element in a single line flow injection system for the amperometric determination of a variety of phenolic substrates of the enzyme. The experimental conditions were studied and optimized for catechol serving as a model compound. Statistical aspects were applied and the sensor characteristics and Michaelis‐Menten constants of the investigated phenolic compounds were calculated and compared with those obtained for solid graphite electrodes modified with Trametes hirsuta laccase. The results showed that the CCE based biosensor in comparison with the solid graphite based biosensor offers a lower detection limit, a wider linear dynamic range, and excellent operational stability with no sensor passivation, indicating that the sol–gel lattice improves the electrochemical behavior of the biosensor.
Electrochemical Determination of Oxalate at Pyrolytic Graphite Electrodes
Authors: Šljukić Biljana , Baron Ronan , Compton Richard G.
Published: April 2007

The electrocatalytic oxidation of oxalate at several carbon based electrodes including basal plane (BPPG) and edge plane (EPPG) pyrolytic graphite and glassy carbon (GC) electrode, was studied. The electrodes were examined for the sensing of oxalate ions in aqueous solutions and all three electrodes showed a response to oxalate additions. The peak of oxalate oxidation at BPPG electrode appeared at lower potential, +1.13 V vs. SCE, than at EPPG (+1.20 V vs. SCE) and GC electrode (+1.44 V vs. SCE). Oxalate oxidation at BPPG electrode was studied in more details for response characteristics (potential and current), effects of pH, temporal characteristics of response potential and current. The results indicated that oxalate oxidation proceeds as two‐electron process at the BPPG electrode with a transfer coefficient β and a diffusion coefficient D evaluated to be 0.45 and 1.03 (±0.04)×10−5 cm2 s−1 respectively. The BPPG electrode was found to be suitable for oxalate determination in aqueous media showing linear response to oxalate concentration with a sensitivity of 0.039 AM−1 and a limit of detection of 0.7 μM.
Simultaneous chiral separation of ephedrine alkaloids by MEKC‐ESI‐MS using polymeric surfactant II: Application in dietary supplements
Authors: Hou Jingguo , Zheng Jie , Shamsi Shahab A.
Published: April 2007

Chiral MEKC‐MS method was utilized for separation, identification, and quantitation of ten enantiomers of ephedrine and related compounds. Enantioselective separations of all ephedrine alkaloids were accomplished through a combination of polysodium N‐undecenoxycarbonyl‐L‐leucinate (poly‐L‐SUCL) with 30% v/v ACN. Interestingly, the more hydrophilic stereoisomers were eluted later than the hydrophobic ones indicating that hydrogen bonding interactions are much stronger than hydrophobic interactions in the presence of ACN in chiral MEKC. The method was validated in terms of linearity, LOD, LOQ, precision and robustness. The method was finally used in the analysis of three standard reference materials (SRMs). Results of (–)‐ephedrine ranged from 12.49 to 0.24 mg/g, for (+)‐pseudoephedrine from 4.04 to 0.019 mg/g, for (–)‐norephedrine from 0.36 to 0.0031 mg/g, for (+)‐norpseudoephedrine from 0.68 to 0.0052 mg/g, for (–)‐methylephedrine from 1.18 to 0.0092 mg/g and for (+)‐methylpseudoephedrine from 0.086 to 0.00037 mg/g in the SRMs.
Simultaneous chiral separation and determination of ephedrine alkaloids by MEKC‐ESI‐MS using polymeric surfactant I: Method development
Authors: Hou Jingguo , Zheng Jie , Rizvi Syed A. A. , Shamsi Shahab A.
Published: April 2007

In this work, simultaneous separation of eight stereoisomers of ephedrine and related compounds ((±)‐ephedrine, (±)‐pseudoephedrine, (±)‐norephedrine and (±)‐N‐methylephedrine) was accomplished using a polymeric chiral surfactant, i.e. polysodium N‐undecenoxycarbonyl‐L‐leucinate (poly‐L‐SUCL) by chiral (C)MEKC‐ESI‐MS. The conditions of CMEKC were first investigated. The baseline separation of all eight stereoisomers of ephedrine and related compounds was achieved under optimum CMEKC conditions (35 mM poly‐L‐SUCL, 15 mM NH4OAc, pH 6.0, 30% v/v ACN, 30 kV and 20°C) in less than 30 min. Next, a central composite design for response surface modeling has been described to evaluate the electrospray chamber parameters and the sheath liquid conditions. Optimum mass abundance of stereoisomers of ephedrine and related compounds was observed using the spray chamber parameters, namely 250°C drying gas temperature and 8 L/min drying gas flow rate at a nebulizer pressure of 4 psi. Furthermore, the experimental design indicates that the optimum mass abundance of the stereoisomers of ephedrine and related compounds can be obtained using a sheath liquid containing 80:20 v/v methanol‐water, 5 mM NH4OAc at pH 8.5 delivered at 5 µL/min. Finally, compared to MEKC‐UV, the use of poly‐L‐SUCL in MEKC‐MS provided significantly higher sensitivity for stereoisomers of ephedrine and related compounds.
The protective effect of N‐acetylcysteine against cyclosporine A‐induced hepatotoxicity in rats
Authors: Kaya Hasan , Koc Ahmet , Sogut Sadik , Duru Mehmet , Yilmaz H. Ramazan , Uz Efkan , Durgut Ramazan
Published: April 2007

The immunosuppressive agent cyclosporine A (CsA) has been reported to exert measurable hepatotoxic effects. One of the causes leading to hepatotoxicity is thought to be reactive oxygen radical formation. The aim of this study was to investigate the effects of N‐acetylcysteine (NAC) treatment on CsA‐induced hepatic damage by both analysing superoxide dismutase (SOD), glutathione peroxidase (GSH‐Px), aspartate aminotransferase (AST) and alanine transaminase (ALT) activities with malondialdehyde (MDA) and nitric oxide (NO) levels, and using an histological approach. CsA administration produced a decrease in hepatic SOD activity, and co‐administration of NAC with CsA resulted in an increase in SOD activity. MDA and NO levels increased in the CsA group and NAC treatment prevented those increases. A significant elevation in serum AST and ALT activities was observed in the CsA group, and when NAC and CsA were co‐administered, the activities of AST and ALT were close to the control levels. CsA treatment caused evident morphological alterations. Control rats showed no abnormality in the cytoarchitecture of the hepatic parenchyma. The co‐administration of NAC with CsA showed no signs of alteration and the morphological pattern was almost similar to the control group. In conclusion, CsA induced liver injury and NAC treatment prevented the toxic side effects induced by CsA administration through the antioxidant and radical scavenging effects of NAC. Copyright © 2007 John Wiley & Sons, Ltd.
Mitochondria a key role in microcystin‐LR kidney intoxication
Authors: La‐Salete R. , Oliveira M. M. , Palmeira C. A. , Almeida J. , Peixoto F. P.
Published: April 2007

Microcystins (MCs) are a group of closely related cyclic heptapeptides produced by a variety of common cyanobacteria. These toxins have been implicated in both human and livestock mortality. Microcystin‐LR could affect renal physiology by altering vascular, glomerular and urinary parameters, indicating that MC‐LR could act directly on the kidney. The aim of the current work was to examine the effect of MC‐LR on mitochondrial oxidative phosphorylation of rat kidney isolated mitochondria.

Furthermore, microcystin‐LR decreased both state 3 and carbonylcyanide p‐trifluoromethoxyphenylhydrazone (FCCP)‐uncoupled respiration. The transmembrane potential was strongly depressed by MC‐LR in a concentration dependent manner, pointing to an uncoupling effect; however, microcystin‐LR did not increase the permeability of the inner mitochondria membrane to protons. Therefore, the transmembrane decrease was a consequence of a strong inhibitory effect on redox complexes. The addition of uncoupling concentrations of MC‐LR to Ca2+‐loaded mitochondria treated with ruthenium red resulted in mitochondrial permeability transition pore (MPTP) opening, as evidenced by mitochondrial swelling in isosmotic sucrose medium. Mitochondrial swelling in the presence of Ca2+ was prevented by cyclosporin A and was drastically inhibited by catalase and dithiothreitol, indicating the participation of mitochondrial generated reactive oxygen species in this process. From this study it can be concluded that the bioenergetic lesion promoted by microcystin‐LR seems to be sufficient to explain renal injury. Copyright © 2007 John Wiley & Sons, Ltd.
A superlinear lower bound for the size of a critical set in a latin square
Authors: Cavenagh Nicholas J.
Published: April 2007

A critical set is a partial latin square that has a unique completion to a latin square, and is minimal with respect to this property. Let scs(n) denote the smallest possible size of a critical set in a latin square of order n. We show that for all n, $scs(n)\geq n\lfloor (\log{n})^{1/3}/2\rfloor$. Thus scs(n) is superlinear with respect to n. We also show that scs(n) ≥ 2n−32 and if n ≥ 25, ${\rm scs}(n)\geq \lceil (3n-7)/2 \rceil$. © 2007 Wiley Periodicals, Inc. J Combin Designs 15: 269–282, 2007
The effect of solids on the electrochemical treatment of olive mill effluents
Authors: Kotta Efi , Kalogerakis Nicolas , Mantzavinos Dionissios
Published: April 2007

The electrochemical oxidation of an olive mill effluent over Ti–Pt anodes was studied. The effluent had an average total chemical oxygen demand (COD) value of 234 g L−1, soluble COD of 61 g L−1, soluble phenolic content 3.4 g L−1, total solids of 80 g L−1 and pH = 5.1. Experiments were conducted in a 10 L vessel with the effluent recirculating at 1 L s−1. The applied current was varied between 5 and 20 A, the salinity between 1 and 4% NaCl, and experiments were performed with the effluent diluted with water to achieve the desired initial concentration. Emphasis was given to the effect of the presence of solids as well as of varying operating conditions on process performance as assessed in terms of COD, color and phenols removal. In general, degradation of phenols occurred relatively fast with conversion increasing with increasing applied current and decreasing initial organic loading and this was accompanied by low COD removal levels and moderate decolorization. The presence of solids had practically no effect on phenols removal, which, in most cases, was complete in less than about 180 min of reaction. However, oxidation in the presence of solids resulted in a substantial solid fraction being dissolved and this consequently increased sample color and the soluble COD content. The solid content typically found in olive mill effluents may partially impede its treatment by electrochemical oxidation, thus requiring more severe operating conditions and greater energy consumption. Copyright © 2007 Society of Chemical Industry
Manganese targets m‐aconitase and activates iron regulatory protein 2 in AF5 GABAergic cells
Authors: Crooks Daniel R. , Ghosh Manik C. , Braun‐Sommargren Michelle , Rouault Tracey A. , Smith Donald R.
Published: April 2007

Studies suggest that disturbances of amino acid metabolism and cellular iron regulation are important mechanisms underlying manganese (Mn) neurotoxicity, although the targets underlying these disturbances are poorly defined. Using the AF5 neural‐derived cell line, which displays GABAergic properties, we showed that Mn significantly increased glutamate release to 174%–214% of that of the control and that the effects of Mn exposure on the metabolism of glutamate, glutamine, alanine, and GABA resembled the effects of fluorocitrate, an inhibitor of aconitase, but not the effects of other toxicants including paraquat, rotenone, or 3‐nitropropionic acid. Consistent with this, Mn inhibited aconitase activity in AF5 cells, resulting in a 90% increase in intracellular citrate; an in vitro assay revealed that m‐aconitase was significantly more sensitive to inhibition by Mn than was c‐aconitase. RNA mobility shift assay and Western blot showed that Mn treatment caused c‐aconitase to be converted to iron regulatory protein 1 (IRP1) and increased the abundance of IRP2, leading to reduced H‐ferritin expression, increased transferrin receptor expression, and increased uptake of transferrin. To determine the relative contributions of IRP1 and IRP2 in mediating the effects of Mn on iron homeostasis, we exposed transgenic fibroblasts lacking either c‐aconitase/IRP1 or IRP2 to Mn. Manganese exposure minimally altered ferritin levels in cells possessing only c‐aconitase/IRP1, whereas cells possessing only IRP2 showed a robust decrease in ferritin, indicating a dominant role of IRP2 in Mn‐induced alteration of iron homeostasis. Together, these results demonstrate that m‐aconitase is an important target of Mn and thatMn‐induced alteration of iron homeostasis is mediated predominantly through IRP2. © 2007 Wiley‐Liss, Inc.
Clinical features of patellar tendinopathy and their implications for rehabilitation
Authors: Crossley Kay M. , Thancanamootoo Kaviraj , Metcalf Ben R. , Cook Jill L. , Purdam Craig R. , Warden Stuart J.
Published: April 2007

This study investigated the clinical features of patellar tendinopathy (PT), with focus on individuals with unilateral and bilateral PT. A cross‐sectional study design was employed to compare individuals with unilateral (n = 14) or bilateral (n = 13) PT and those without PT (control, n = 31). Features assessed included thigh strength (normalized peak knee extensor torque) and flexibility (sit‐and‐reach and active knee extension), calf endurance (heel‐rise test), ankle flexibility (dorsiflexion), alignment measures (arch height and leg length difference), and functional measures (hop for distance and 6 m hop test). Groups were matched for age and height; however, unilateral and bilateral PT had greater mass with a higher body mass index (BMI) than control. Also, bilateral PT performed more sport hours per week than both unilateral PT and control. Unilateral PT had less thigh strength than control and bilateral PT, whereas bilateral PT had more thigh flexibility than control and unilateral PT. Both unilateral and bilateral PT had altered alignment measures compared to control. Features that predicted symptoms in PT were lower thigh flexibility and strength, whereas those that predicted function were higher thigh strength and lower ankle flexibility. These findings indicate that unilateral and bilateral PT represent distinct entities, and that thigh strength appears particularly important in PT as it predicted both symptoms and function in PT. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1164–1175, 2007
New protein PCiP from edible golden oyster mushroom (Pleurotus citrinopileatus) activating murine macrophages and splenocytes
Authors: Sheu Fuu , Chien Po‐Jung , Wang His‐Kai , Chang Hui‐Hsin , Shyu Yuan‐Tay
Published: April 2007

A new immunomodulatory protein (PCiP) was purified from an edible golden oyster mushroom (Pleurotus citrinopileatus) by extraction with 5% (v/v) cold acetic acid in the presence of 0.1% (v/v) 2‐mercaptoethanol, followed by ammonium sulfate fractionation, DE‐52 and MonoQ anion‐exchange chromatography. Electrophoresis assays demonstrated that the molecular mass of PCiP was approximately 15.0 kDa and its pI was around 5.2. PCiP is a simple protein without carbohydrate, and cannot agglutinate mouse red blood cells, suggesting PCiP is not a lectin. In addition, PCiP (5–20 µg mL−1) alone activated murine splenocytes, and markedly increased their proliferation and gamma‐interferon (IFN‐γ secretion, but suppressed MTT metabolization, while murine splenocytes were simultaneously stimulated by the mitogen concanavalin A (ConA). Furthermore, PCiP (5–20 µg mL−1) directly activated murine macrophages and increased the production of both the nitric oxide (NO) and tumor necrosis factor‐alpha (TNF‐α by RAW 264.7 macrophages. These findings suggest that PCiP could strengthen both the innate and adaptive responses of its host. Copyright © 2007 Society of Chemical Industry
Profiling glucosinolates in vegetative and reproductive tissues of four Brassica species of the U‐triangle for their biofumigation potential
Authors: Bellostas Natalia , Sørensen Jens C , Sørensen Hilmer
Published: April 2007

Glucosinolates are amino acid derived allelochemicals present in all plants of the order Capparales. These compounds are degraded by myrosinase isoenzymes, releasing a series of biologically active products defined by the parent glucosinolate and the reaction conditions. Species within the Brassicaceae are found to differ in their glucosinolate profile and glucosinolate concentrations. Different tissues within a single plant also show such variations, which are further influenced by the growth stage and environmental conditions. In the experiments described in this paper, four Brassica species of the U‐triangle (B. carinata, B. nigra, B. juncea and B. rapa) were compared with respect to their glucosinolate profiles in roots, stems, leaves and reproductive organs at different developmental stages. The glucosinolate profile of corresponding ripe seeds was also determined. Prop‐2‐enylglucosinolate was identified as the major glucosinolate in the three mustards, where it represented over 90% of the total glucosinolate concentration of ripe seeds and over 50% of green tissues. The relative concentration of this glucosinolate increased in all tissues during plant growth. Brassica rapa showed a different glucosinolate profile than the three mustards, with higher concentrations of but‐3‐enylglucosinolate, 2‐hydroxybut‐3‐enylglucosinolate and 2‐hydroxypent‐4‐enylglucosinolate. The concentration of indol‐3‐ylmethylglucosinolates was also higher in B. rapa than in the mustard plants, with 4‐hydroxyglucobrassicin representing 30% of the total glucosinolate concentration in ripe seeds. The total glucosinolate concentration of the species studied varied with growth stage and the mustards achieved a maximum towards the end of the period monitored. Glucosinolate concentration decreased in roots and leaves but increased in reproductive tissues. The determined glucosinolate profiles are an initial step in assessing the biofumigation potential of these species of the Brassicaceae family. Copyright © 2007 Society of Chemical Industry
Multiple wavelength Brillouin fiber laser from injection of intense signal light
Authors: Harun S W , Shirazi M R , Ahmad H
Published: April 2007

A multiple wavelength Brillouin fiber laser (BFL) is demonstrated using an injection of intense light at 1480 nm. The light generates Raman gain at around 1560 nm to amplify the Brillouin-Rayleigh backscattered light in the medium and allows the generation of multiple lines by self-feedback-seeding effects. Three Stokes are obtained in the BFL with the maximum power of the first Stokes at approximately -6 dBm from the injection of 1480 nm light at 150 mW. The line spacing is measured to be approximately 0.08 nm. There is no significant change in the power of the first Stokes with the injection of 1480 nm light; however the powers of additional Stokes are highest at Brillouin pump of 1560 nm.
Functionalized Multi‐Walled Carbon Nanotubes Prepared by In Situ Polycondensation of Polyurethane
Authors: Chen Xianhong , Chen Xiaojin , Lin Ming , Zhong Wenbin , Chen Xiaohua , Chen Zhenhua
Published: April 2007

Treating MWCNTs with an acidic solution (concentrated H2SO4/HNO3; 3:1) and subsequently with succinic acid peroxide leads to MWCNTs functionalized with carboxyl groups on their sidewalls (or surfaces). These MWCNT‐COOH were converted to MWCNT‐COCl and further to MWCNT‐NH2. The PU was covalently coated onto the sidewalls (or surfaces) of the MWCNT by in situ polymerization of TDI under ultrasound in the presence of MWCNT‐NH2. The results show that PU is chemically tethered to the MWCNT sidewalls (or surfaces) via the ∼HNCONH∼ linkage, with a thickness in the range of approximately 2 to 5 nm, and the amount of grafted PU is about 34 wt.‐%.

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Formation and Photoresponsive Properties of Giant Microvesicles Assembled from Azobenzene‐Containing Amphiphilic Diblock Copolymers
Authors: Su Wei , Han Kuo , Luo Yanhua , Wang Zhong , Li Yinmei , Zhang Qijin
Published: April 2007

Diblock copolymers composed of poly(acrylic acid) and poly{6‐[4‐(4‐methylphenylazo)phenoxy]hexyl acrylate} (PAA‐block‐PAzoM) were synthesized by RAFT polymerization. In a mixture of H2O and THF, PAA‐block‐PAzoM self‐assembled into giant spherical microvesicles, which were dispersed in the mixture. Using UV‐vis spectroscopy and optical microscopy, it is demonstrated that the spherical shape of the vesicles results from a framework composed of the azobenzene H‐aggregate skeleton. A plausible structural model of the microvesicles is proposed, and a discussion on the formation of H‐aggregates and the photoresponsive properties is presented.

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