bluuebunny/crossref_metadata_2025 huggingface dataset:
Native multimer analysis of plasma and platelet von Willebrand factor compared to denaturing separation: Implication for the interpretation of satellite bands
Authors: Hohenstein Kurt , Griesmacher Andrea , Weigel Günter , Golderer Georg , Ott Helmut Werner
Published: June 2011

Blue native electrophoresis (BNE) was applied to analyze the von Willebrand factor (vWF) multimers in their native state and to present a methodology to perform blue native electrophoresis on human plasma proteins, which has not been done before. The major difference between this method and the commonly used SDS‐agarose gel electrophoresis is the lack of satellite bands in the high‐resolution native gel. To further analyze this phenomenon, a second dimension was performed under denaturing conditions. Thereby, we obtained a pattern in which each protein sub‐unit from the first dimension dissociates into three distinct sub‐bands. These bands confirm the triplet structure, which consists of an intermediate band and two satellite bands. By introducing the second dimension, our novel method separates the triplet structure into a higher resolution than the commonly used SDS‐agarose gel electrophoresis does. This helps considerably in the classification of ambiguous von Willebrand's disease subtypes. In addition, our method has the additional advantage of being able to resolve the triplet structure of platelet vWF multimers, which has not been identified previously through conventional SDS‐agarose electrophoresis multimer analysis. This potential enables us to compare the triplet structure from platelet and plasmatic vWF, and may help to find out whether structural abnormalities concern the vWF molecule in the platelet itself, or whether they are due to the physiological processing of vWF shed into circulation. Owing to its resolution and sensitivity, this native separation technique offers a promising tool for the analysis and detection of von Willebrand disorder, and for the classification of von Willebrand's disease subtypes.
Immunoaffinity capillary electrophoresis: A new versatile tool for determining protein biomarkers in inflammatory processes
Authors: Guzman Norberto A. , Phillips Terry M.
Published: June 2011

Many diseases caused by inflammatory processes can progress to a chronic state causing deterioration in the quality of life and a poor prognosis for long‐term survival. To address inflammatory diseases effectively, early detection and novel therapeutics are required. However, this can be challenging, in part because of the lack of early predictive biomarkers and the limited availability of adequate technologies capable of the identification/characterization of key predictive biomarkers present in biological materials, especially those found at picomolar concentrations and below. This review highlights the need for state‐of‐the art methodologies, with high‐sensitivity and high‐throughput capabilities, for determination of multiple biomarkers. Although many new biomarkers have been discovered recently, existing technology has failed to successfully bring this advancement to the patient's bedside. We present an overview of the various advances available today to extend the discovery of predictive biomarkers of inflammatory diseases; in particular, we review the technology of immunoaffinity capillary electrophoresis (IACE), which combines the use of antibodies as highly selective capture agents with the high resolving power of capillary electrophoresis. This two‐dimensional hybrid technology permits the quantification and characterization of several protein biomarkers simultaneously, including subtle structural changes such as variants, isoforms, peptide fragments, and post‐translational modifications. Furthermore, the results are rapid, sensitive, can be performed at a relatively low cost, without the introduction of false positive or false negative data. The IACE instrumentation can have relevance to medical, pharmaceutical, environmental, military, cultural heritage (authenticity of art work), forensic science, industrial and research fields, and in particular as a point‐of‐care biomarker analyzer in translational medicine.
Recent developments in capillary and chip electrophoresis of bioparticles: Viruses, organelles, and cells
Authors: Subirats Xavier , Blaas Dieter , Kenndler Ernst
Published: June 2011

In appropriate aqueous buffer solutions, biological particles usually exhibit a particular electric surface charge due to exposed charged or chargeable functional groups (amino acid residues, acidic carbohydrate moieties, etc.). Consequently, these bioparticles can migrate in solution under the influence of an electric field allowing separation according to their electrophoretic mobilities or their pI values. Based on these properties, electromigration methods are of eminent interest for the characterization, separation, and detection of such particles. The present review discusses the research papers published between 2008 and 2010 dealing with isoelectric focusing and zone electrophoresis of viruses, organelles and microorganisms (bacteria and yeast cells) in the capillary and the chip format.
Concentration and fractionation by isoelectric trapping in a micropreparative‐scale multicompartmental electrolyzer having orthogonal pH gradients. Part 2
Authors: Lim Peniel J. , Vigh Gyula
Published: June 2011

A micropreparative‐scale multicompartmental electrolyzer called ConFrac has been developed and tested for isoelectric trapping separations. ConFrac can be operated in pass‐by‐pass mode or recirculating mode, using either asymmetrical feeding (feed enters only the anodic or the cathodic flow‐through compartment) or symmetrical feeding (feed enters both the anodic and the cathodic flow‐through compartment). Symmetrical feeding results in higher processing rates and is the preferred operation mode. Residence time in the flow‐through compartments is set as a compromise between processing rate and temperature rise in the effluent. Ampholytic components have been isolated from 5 to 50 mL volumes of micromolar feed solutions and hundredfold concentrated into 100‐μL collection compartments. Samples containing ampholytic analytes in highly conducting salt solutions were readily desalted and fractionated in ConFrac in one operation. pH transients formerly observed in other isoelectric trapping devices were observed in ConFrac as well. The pH transients were caused by the unequal ion transmission rates of the anodic‐ and cathodic‐side buffering membranes.
Combining size‐exclusion chromatography and fully automated chip‐based nanoelectrospray quadrupole time‐of‐flight tandem mass spectrometry for structural analysis of chondroitin/dermatan sulfate in human decorin
Authors: Zamfir Alina D. , Flangea Corina , Sisu Eugen , Seidler Daniela G. , Peter‐Katalinić Jasna
Published: June 2011

Chondroitin/dermatan sulfate (CS/DS) chain of decorin (DCN) from human skin fibroblasts (HSk) was released by reductive β‐elimination reaction and digested with chondroitin AC I lyase. Enzymatic hydrolysis mixture of CS/DS chains was separated by size‐exclusion chromatography (SEC). Collected octasaccharide fraction was subjected to fully automated chip‐based nanoelectrospray (nanoESI) quadrupole time‐of‐flight (QTOF) MS and tandem MS (MS/MS). MS of human skin fibroblasts DCN CS/DS displayed a high complexity due to the large variety of glycoforms, which under chip‐nanoESI MS readily ionized to form multiply charged ions. Except for the regularly tetrasulfated octasaccharide, the investigated fraction contained four additional octasaccharides of atypical sulfation status. Two new oversulfated glycoforms and two undersulfated species were identified. Remarkably, the series of decasaccharides discovered in the same SEC pool was found to encompass a trisulfated and a novel hexasulfated [4,5‐Δ‐GlcAGalNAc(IdoAGalNAc)4] species. MS/MS by collision‐induced dissociation (CID) on the [M‐4H]4 ion corresponding to the previously not reported [4,5‐Δ‐GlcAGalNAc(IdoAGalNAc)3](5S) corroborated for a novel motif in which three N‐acetylgalactosamine (GalNAc) moieties are monosulfated, 4,5‐Δ‐GlcA and the first IdoA from the non‐reducing end bear one sulfate group each, while the second N‐acetylgalactosamine from the reducing end is unsulfated.
Single-substance and mixture toxicity of five pharmaceuticals and personal care products to marine periphyton communities
Authors: Backhaus Thomas , Porsbring Tobias , Arrhenius Åsa , Brosche Sara , Johansson Per , Blanck Hans
Published: June 2011

The single-substance and mixture toxicity of five pharmaceuticals and personal care products (fluoxetine, propranolol, triclosan, zinc-pyrithione, and clotrimazole) to marine microalgal communities (periphyton) was investigated. All compounds proved to be toxic, with median effective concentration values (EC50s) between 1,800 nmol/L (triclosan) and 7.2 nmol/L (Zn-pyrithione). With an EC50 of 356 nmol/L, the toxicity of the mixture falls into this span, indicating the absence of strong synergisms or antagonisms. In fact, a comparison with mixture toxicity predictions by the classical mixture concepts of concentration addition and independent action showed a good predictability in the upper effect range. However, the mixture provoked stimulating effects (hormesis) in the lower effect range, hampering the application of either concept. An independent repetition of the mixture experiment resulted in a principally similar concentration–response curve, again with clear hormesis effects in the lower range of test concentrations. However, the curve was shifted toward higher effect concentrations (EC50 1,070 nmol/L), which likely is due to changes in the initial species composition. Clear mixture effects were observed even when all five components were present only at their individual no-observed-effect concentrations (NOECs). These results show that, even with respect to mixtures of chemically and functionally dissimilar compounds, such as the five pharmaceuticals and personal care products investigated, environmental quality standards must take possible mixture effects from low-effect concentrations of individual compounds into consideration. Environ. Toxicol. Chem. 2011;30:2030–2040. © 2011 SETAC
Dechlorane Plus in house dust from E-waste recycling and urban areas in South China: Sources, degradation, and human exposure
Authors: Wang Jing , Tian Mi , Chen She-Jun , Zheng Jing , Luo Xiao-Jun , An Tai-Cheng , Mai Bi-Xian
Published: June 2011

Dechlorane Plus (DP) was measured in house dust from e-waste recycling and from urban and rural areas of South China, with geometric mean concentrations of 604, 14.5, and 2.89 ng/g, respectively. Dechlorane Plus in house dust in the e-waste area originated from e-waste recycling activities, whereas household appliances served as a major source of DP in urban house dust. The isomer ratios (fanti) of DP in most dust samples from the e-waste area were significantly lower than those in the urban and rural dust samples and the commercial mixture. Several [−1Cl + H] and [−2Cl + 2H] dechloro-DPs were identified in house dust from the e-waste area, and an a-Cl11 DP was qualified with concentrations of <55.1 ng/g. Photolytic degradation experiments were conducted by exposing anti-DP, syn-DP, and commercial DP solutions to ultraviolet (UV) light. The slight difference in isomeric half-life derived by photodegradation, as well as the lower fanti values in the e-waste combusted residue, suggest a significant influence of isomer-specific thermal degradation of DP during e-waste burning on isomer composition in house dust in the e-waste area. The average estimated daily intakes (EDIs) of DP via house dust ranged from 0.06 to 30.2 ng/d for adults and 0.14 to 121 ng/d for toddlers in the studied area. The average EDIs of a-Cl11 DP for adults and toddlers in the e-waste area were 0.07 and 0.18 ng/d, respectively. Environ. Toxicol. Chem. 2011;30:1965–1972. © 2011 SETAC
Evidence for behavioral preference toward environmental concentrations of urban-use herbicides in a model adult fish
Authors: Tierney Keith B , Sekela Mark A , Cobbler Christine E , Xhabija Besa , Gledhill Melissa , Ananvoranich Sirinart , Zielinski Barbara S
Published: June 2011

Fish live in waters of contaminant flux. In three urban, fish-bearing waterways of British Columbia, Canada, we found the active ingredients of WeedEx®, KillEx®, and Roundup® herbicide formulations (2,4-D, dicamba, glyphosate, and mecoprop) at low to high ng/L concentrations (0.26 to 309 ng/L) in routine conditions, i.e., no rain for at least one week. Following rain, these concentrations increased by an average of eightfold, suggesting runoff as a major route of herbicide introduction in these waterways. To determine whether fish might be able to limit point-source exposures through sensory-driven behaviors, we introduced pulses of representative herbicide mixtures to individual adult zebrafish (a model species) in flow-through tanks. Fish did the opposite of limit exposure; they chose to spend more time in pulses of herbicide mixtures representative of those that may occur with rain events. This attraction response was not altered by a previous 4-d exposure to lower concentrations of the mixtures, suggesting fish will not learn from previous exposures. However, previous exposures did alter an attraction response to an amino acid prevalent in food (L-alanine). The present study demonstrates that fish living within urban waterways may elect to place themselves in herbicide-contaminated environments and that these exposures may alter their behavioral responses to cues necessary for survival.Environ. Toxicol. Chem. 2011;30:2046–2054. © 2011 SETAC
Landscape-level patterns of mercury contamination of fish in North Texas, USA
Authors: Drenner Ray W , Chumchal Matthew M , Wente Stephen P , McGuire Mandy , Drenner S. Matthew
Published: June 2011

Mercury (Hg) is a toxic metal that is found in aquatic food webs and is hazardous to humans. An emerging conceptual model predicts that the areas of the landscape that have the potential to contain food webs with elevated concentrations of Hg are those that receive high amounts of Hg and sulfate deposition and have high coverage of forests and wetlands and low coverage of agriculture. The objective of the present study was to test this conceptual model using concentrations of Hg in largemouth bass (Micropterus salmoides) from 145 reservoirs in four ecoregions of North Texas. The highest level of Hg contamination in fish was in the South Central Plains, the ecoregion that receives the highest levels of Hg and sulfate deposition and contains extensive forest and wetland habitat and little agriculture. The present study has important implications for other areas of the United States, because the South Central Plains extend into parts of Oklahoma, Louisiana, and Arkansas, covering a total area of 152,132 km2 of the southern United States. Environ. Toxicol. Chem. 2011;30:2041–2045. © 2011 SETAC
Effects of the antihistamine diphenhydramine on selected aquatic organisms
Authors: Berninger Jason P , Du Bowen , Connors Kristin A , Eytcheson Stephanie A , Kolkmeier Mark A , Prosser Krista N , Valenti Theodore W , Chambliss C. Kevin , Brooks Bryan W
Published: June 2011

In recent years pharmaceuticals have been detected in aquatic systems receiving discharges of municipal and industrial effluents. Although diphenhydramine (DPH) has been reported in water, sediment, and fish tissue, an understanding of its impacts on aquatic organisms is lacking. Diphenhydramine has multiple modes of action (MOA) targeting the histamine H1, acetylcholine (ACh), and 5-HT reuptake transporter receptors, and as such is used in hundreds of pharmaceutical formulations. The primary objective of this study was to develop a baseline aquatic toxicological understanding of DPH using standard acute and subchronic methodologies with common aquatic plant, invertebrate, and fish models. A secondary objective was to test the utility of leveraging mammalian pharmacology information to predict aquatic toxicity thresholds. The plant model, Lemna gibba, was not adversely affected at exposures as high as 10 mg/L. In the fish model, Pimephales promelas, pH affected acute toxicity thresholds and feeding behavior was more sensitive (no-observed-effect concentration = 2.8 µg/L) than standardized survival or growth endpoints. This response threshold was slightly underpredicted using a novel plasma partitioning approach and a mammalian pharmacological potency model. Interestingly, results from both acute mortality and subchronic reproduction studies indicated that the model aquatic invertebrate, Daphnia magna, was more sensitive to DPH than the fish model. These responses suggest that DPH may exert toxicity in Daphnia through ACh and histamine MOAs. The D. magna reproduction no-observed-effect concentration of 0.8 µg/L is environmentally relevant and suggests that additional studies of more potent antihistamines and antihistamine mixtures are warranted. Environ. Toxicol. Chem. 2011;30:2065–2072. © 2011 SETAC
Using ptilochronology to determine daily mercury deposition in feathers of nestling waterbirds
Authors: Clarkson Charles E , Riscassi Ami
Published: June 2011

Feathers are commonly used biomarkers of mercury (Hg) contamination in waterbird species. Most studies that analyze waterbird feathers for Hg content report concentrations on a per-unit mass basis. While this is appropriate for intraspecific comparisons, we suggest a more effective method for studies comparing multiple species of similar size and with similar foraging habits. Ptilochronology is a technique for determining the rate of feather growth in individuals based on their nutritional condition. When paired with Hg analysis, feather growth rates can be used to calculate the average daily Hg deposition into a feather. In this study we used this technique in comparison with the commonly used metric of Hg per-unit feather mass in two waterbird species. Average daily Hg deposition into feathers was 26.7% more sensitive to differences in Hg between the two species, suggesting that this may be a more biologically meaningful metric to use in interspecific comparisons. Environ. Toxicol. Chem. 2011;30:2081–2083. © 2011 SETAC
PCB and organochlorine pesticides in northern fulmars (Fulmarus glacialis) from a High Arctic colony: Chemical exposure, fate, and transfer to predators
Authors: Foster Karen L , Mallory Mark L , Hill Laura , Blais Jules M
Published: June 2011

Organochlorine contaminant concentrations, associated fugacities, and stable isotopes of nitrogen (δ15N) are reported for liver, whole body homogenate, and opportunistically collected samples of prey (amphipods), stomach oils, digestive tract contents, and guano for northern fulmars (Fulmarus glacialis) collected at Cape Vera, Devon Island in the Canadian High Arctic. Liver concentrations of polychlorinated biphenyls (ΣPCB) and ΣDDT were on average 49.9 ± 35.4 ng g−1 and 29.9 ± 25.2 ng g−1 wet weight, respectively. Whole body homogenate concentrations of ΣPCB and ΣDDT were 637 ± 293 ng g−1 and 365 ± 212 ng g−1 wet weight, respectively. A mass and energy balance showed that whole body contaminant concentrations, which are seldom reported for Arctic seabirds, are critical in determining contaminant exposure and associated risk to predators such as the Arctic fox (Alopex lagopus). Biomagnification in the fulmars is evident, because concentrations and fugacities of contaminants were generally one to three orders of magnitude higher than those of likely prey items. The fate of diet-derived contaminants along the digestive tract is discussed, in particular with respect to stomach oils, which are used to feed chicks and for defensive purposes. The benefits of considering both concentrations and fugacities are demonstrated and provide information on the absorption and distribution of chemicals within the fulmars and contaminant transfer to offspring and predators. Environ. Toxicol. Chem. 2011;30:2055–2064. © 2011 SETAC
Time‐dependent simulation of cavitating flow with k − ℓ turbulence models
Authors: Decaix Jean , Goncalvès Eric
Published: June 2011

A compressible, multiphase, one‐fluid Reynolds‐averaged Navier–Stokes solver has been developed to study turbulent cavitating flows. The interplay between turbulence and cavitation regarding the unsteadiness and structure of the flow is complex and not well understood. This constitutes a critical point to accurately simulate the dynamic behavior of sheet cavities. In the present study, different formulations based on a k − ℓ transport‐equation model are investigated and a scale‐adaptive formulation is proposed. Numerical results are given for a Venturi geometry and comparisons are made with experimental data. The scale‐adaptive model shows several improvements compared with standard turbulence models. Copyright © 2011 John Wiley & Sons, Ltd.
Free (open) boundary condition: some experiences with viscous flow simulations
Authors: Mitsoulis Evan , Malamataris Nikolaos A.
Published: June 2011

The free (or open) boundary condition (FBC, OBC) was proposed by Papanastasiouet al.(A new outflow boundary condition, International Journal for Numerical Methods in Fluids, 1992; 14:587–608) to handle truncated domains with synthetic boundaries where the outflow conditions are unknown. In the present work, implementation of the FBC has been tested in several benchmark problems of viscous flow in fluid mechanics. The FEM is used to provide numerical results for both cases of planar and axisymmetric domains under laminar, isothermal or non‐isothermal, steady‐state conditions, for Newtonian fluids. The effects of inertia, gravity, compressibility, pressure dependence of the viscosity, slip at the wall, and surface tension are all consideredindividuallyin the extrudate‐swell benchmark problem for a wide range of the relevant parameters. The present results extend previous ones regarding the applicability of the FBC and show cases where the FBC is inappropriate, namely in the extrudate‐swell problem with gravity or surface‐tension effects. Particular emphasis has been given to the pressure at the outflow, which is the most sensitive quantity of the computations. In all cases where FBC is appropriate, excellent agreement has been found in comparisons with results from very long domains. The formulation for Picard‐type iterations is given in some detail, and the differences with the Newton–Raphson formulation are highlighted regarding some computational aspects. Copyright © 2011 John Wiley & Sons, Ltd.
Carbon Aerogels as Catalyst Supports and First Insights on Their Durability in Proton Exchange Membrane Fuel Cells
Authors: Ouattara‐Brigaudet M. , Beauger C. , Berthon‐Fabry S. , Achard P.
Published: June 2011

To enable a large penetration of proton exchange membrane fuel cells (PEMFC) on the market, the durability of these systems must be improved. This work aims at evaluating the durability of carbon aerogels used as cathode catalyst support and at comparing it with the durability of a commercial electrocatalyst Tanaka Kikinzoku Group (TKK). To do so, platinum was deposited on carbon aerogel. Resulting electrocatalysts were then used to prepare 50 cm2 membrane electrode assemblies (MEA). MEAs were then submitted to an ageing protocol consisting in operating the cell under H2/N2 and in maintaining the cell potential at 1.2 V during cycles of 7 h. MEA performance was then evaluated every 7 h before the following cycle. We showed that, in our testing conditions, neither carbon aerogel nor the commercial electrocatalyst can fulfil DOE objectives in terms of durability. The lower carbon aerogel corrosion resistance as compared to that one of the commercial electrocatalyst can be explained by their low degree of graphitisation. Carbon aerogels durability could be increased thanks to a pyrolysis at higher temperatures.
Paleoenvironmental analysis of the Mawaki archaeological site, central Japan, in relation to the stratigraphic position of dolphin bones
Authors: Itoh Yasuto , Takemura Keiji , Nakamura Toshio , Hasegawa Shin , Takada Hideki
Published: June 2011

In order to elucidate the paleoenvironment associated with the early Holocene Mawaki archaeological site on the Noto Peninsula of central Japan, a high‐resolution stratigraphic study was conducted of 17 boreholes drilled at the archaeological site. We selected three boreholes for which lithological and/or chronological data are reported. Initial magnetic susceptibility was utilized for correlation of clastic core samples with the assistance of 26 radiocarbon dates. Four lithological units (A, B, C, and D in ascending order) were identified and interpreted as a sequence in a cycle of marine transgression and regression. Dated coastal horizons were chosen to indicate former sea levels. A Holocene relative sea level curve was generated on the basis of the geological data, and a rapid rise from 8000cal. yr B.P. to 7000cal. yr B.P. and a succeeding minor sea level fall represent the basic eustatic trend around the Sea of Japan because hydroisostatic and tectonic effects are moderate in the study area. Abundant dolphin bones lay just above the top of the marine sequence (boundary between Units C and D), located in the seashore environment. Cultural artifacts are found in a subaerial deposit (Unit D) near the dolphin bone level that is assigned to a period of high, stable sea level after the post‐glacial eustatic highstand. Dolphin bones are associated with stone artifacts (arrowheads, knives, and scrapers) and ritual wood columns, indicating the presence of a longstanding fishery during the early Holocene on the Sea of Japan coast. © 2011 Wiley Periodicals, Inc.
ESTIMATING ADVERSE SELECTION AND MORAL HAZARD EFFECTS WITH HOSPITAL INVOICES DATA IN A GOVERNMENT‐CONTROLLED HEALTHCARE SYSTEM
Authors: Liu Xiangping , Nestic Danijel , Vukina Tomislav
Published: June 2011

We use invoices for hospital services from a regional hospital in Croatia to test for adverse selection and moral hazard. There are three categories of patients: with no supplemental insurance, who bought it, and who are entitled to it for free. Our identification procedure relies on the premise that the difference in the observed medical care consumption between the patients who bought the insurance and those entitled to free insurance is caused by pure selection effect, whereas the difference in healthcare consumption between the group that received the free insurance and the group that has no insurance is due to moral hazard. Results show favorable selection for patients in 20‐ to 30‐year‐old cohort and significant moral hazard for all age cohorts. The selection effect reverses its sign in older cohorts explained by the differences in risk aversion across cohorts caused by the timing of transition from socialism to market economy. Copyright © 2011 John Wiley & Sons, Ltd.
Retracted: A hybrid artificial intelligence sales‐forecasting system in the convenience store industry
Authors: Lee Wan‐I , Shih Bih‐Yaw , Chen Chen‐Yuan
Published: June 2011

Recently, there has been increasing interest in computer‐aided ergonomics and its applications, such as in the fields of intelligent robots, intelligent mobiles, intelligent stores, and so on. The operation of convenience stores (CVS) in Taiwan is facing a crossover revolution by providing multiple services, including daily fresh foods, a café, ticketing, and a grocery. Therefore, forecasting the daily sales of fresh foods is getting more and more complex due to the influence of both internal and external factors. Eventually, a reliable sales‐forecasting system will play an important role in improving business strategies and increasing competitive advantages. The purpose of this study is the development of an enhanced hybrid sales‐forecasting model of fresh foods, called ECFM (Enhanced Cluster and Forecast Model), for CVSs by combining a self‐organization map (SOM) neural network and radial basis function (RBF) neural networks. The model is evaluated for a six‐month sales data set of daily fresh foods at a chained CVS in Taiwan. Meanwhile, the performance of the proposed model is compared with that of fuzzy neural network (FNN) and cluster and forecast model (CFM). The result reveals that the proposed model is not only amenable but can also promise the fresh food sales forecasting for CVSs. © 2011 Wiley Periodicals, Inc.
Retracted: A novel viewpoint on information and interface design for auction web sites
Authors: Kuo Hui‐Ming , Chen Cheng‐Wu
Published: June 2011

For the reason of convenience, auction sites are one of the most popular and quickly developing of Internet shopping sites. There have been many problems, however, arising in relation to online auction commerce; these problems have been dealt with one by one. In addition to the important issue of security, some customers have faced problems such as complicated processes, insufficient product information, and bad interface design. Based on the consumer behavior model that we have built on auction sites, the purpose of this study is to evaluate the information and interface design for current domestic and foreign auction sites. The results indicated that some auction Web sites provided insufficient information and inconvenient interface design during some shopping steps. Foreign auction Web sites provided sufficient information and a more convenient interface design than did the domestic auction Web sites. The results, hopefully, can be used as the reference for online auction Web sites to provide customers more convenient shopping environments. © 2011 Wiley Periodicals, Inc.
Single amino acid arginine starvation efficiently sensitizes cancer cells to canavanine treatment and irradiation
Authors: Vynnytska‐Myronovska Bozhena , Bobak Yaroslav , Garbe Yvette , Dittfeld Claudia , Stasyk Oleh , Kunz‐Schughart Leoni A.
Published: June 2011

Single amino acid arginine deprivation is a promising strategy in modern metabolic anticancer therapy. Its potency to inhibit tumor growth warrants the search for rational chemo‐ and radio‐therapeutic approaches to be co‐applied. In this report, we evaluated, for the first time, the efficacy of arginine deprivation as anticancer therapy in three‐dimensional (3D) cultures of human tumor cells, and propose a new combinatorial metabolic‐chemo‐radio‐treatment regime based on arginine starvation, low doses of arginine natural analog canavanine and irradiation. A sophisticated experimental setup was designed to evaluate the impact of arginine starvation on four human epithelial cancer cell lines in 2D monolayer and 3D spheroid culture. Radioresponse was assessed in colony formation assays and by monitoring spheroid regrowth probability following single dose irradiation using a standardized spheroid‐based test platform. Surviving fraction at 2 Gy (SF2Gy) and spheroid control dose50(SCD50) were calculated as analytical endpoints. Cancer cells in spheroids are much more resistant to arginine starvation than in 2D culture. Spheroid volume stagnated during arginine deprivation, but even after 10 days of starvation, 100% of the spheroids regrew. Combination treatment, however, was remarkably efficient. In particular, pretreatment of cancer cells with the arginine‐degrading enzyme arginase combined with or without low concentration of canavanine substantially enhanced cell radioresponse reflected by a loss in spheroid regrowth probability and SCD50values reduced by a factor of 1.5–3. Our data strongly suggest that arginine withdrawal alone or in combination with canavanine is a promising antitumor strategy with potential to enhance cancer cure by irradiation.
MDM2 promoter SNP309 is associated with an increased susceptibility to chronic lymphocytic leukemia and correlates with MDM2 mRNA expression in Chinese patients with CLL
Authors: Dong Hua‐Jie , Fang Cheng , Fan Lei , Zhu Dan‐Xia , Wang Dong‐Mei , Zhu Hua‐Yuan , Zhuang Yun , Miao Kou‐Rong , Liu Peng , Xu Wei , Li Jian‐Yong
Published: June 2011

A single nucleotide polymorphism (SNP) at position 309 in the promoter region of MDM2 leading to increased expression of MDM2 and attenuated function of p53 has recently been suggested as an unfavorable prognostic marker in chronic lymphocytic leukemia (CLL) although this has been questioned. The MDM2 SNP309 genotypes in 173 CLL patients and 260 healthy controls were detected by the polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) method, which was confirmed by direct DNA sequencing. Compared with the T/T genotype, the SNP309 G/G genotype instead of T/G heterozygote was associated with a significantly increased risk of CLL (OR = 2.84; 95% CI 1.61–5.03; p < 0.001). Age at onset of CLL was similar irrespective of MDM2 status. MDM2 mRNA expression within CLL of G/G genotype was significantly higher than that in T/G (p = 0.009) and T/T genotypes (p < 0.001). Excluding patients with p53 deletions or mutations enhanced the significance of the findings (G/G vs. T/T, p < 0.001; G/G vs. T/G p = 0.001), which prompted us to study the role of the polymorphism in p53 wild‐type individuals. In the p53 wild‐type groups, survival analysis showed that the patients with MDM2 SNP309 G/G and T/G genotypes both had significantly shorter treatment‐free survival (TFS) than SNP309 T/T genotype. Notably, univariate and multivariate analyses showed that MDM2 SNP309 genotypes were associated with TFS. These data show that MDM2 309G polymorphisms contribute to the risk of developing CLL. The unfavorable MDM2 SNP309 G/G genotype was associated with an increase of MDM2 mRNA expression. MDM2 SNP309 was found to be associated with TFS in p53 wild‐type Chinese CLL populations.
ARFGAP3, an androgen target gene, promotes prostate cancer cell proliferation and migration
Authors: Obinata Daisuke , Takayama Ken‐ichi , Urano Tomohiko , Murata Taro , Ikeda Kazuhiro , Horie‐Inoue Kuniko , Ouchi Yasuyoshi , Takahashi Satoru , Inoue Satoshi
Published: June 2011

ADP ribosylation factor GTPase‐activating protein 3 (ARFGAP3) is a GTPase‐activating protein that associates with the Golgi apparatus and regulates the vesicular trafficking pathway. In the present study, we examined the contribution of ARFGAP3 to prostate cancer cell biology. We showed that ARFGAP3 expression was induced by 100 nM of dihydrotestosterone (DHT) at both the mRNA and protein levels in androgen‐sensitive LNCaP cells. We generated stable transfectants of LNCaP cells with FLAG‐tagged ARFGAP3 or a control empty vector and showed that ARFGAP3 overexpression promoted cell proliferation and migration compared with control cells. We found that ARFGAP3 interacted with paxillin, a focal adhesion adaptor protein that is important for cell mobility and migration. Small interfering RNA (siRNA)‐mediated knockdown of ARFGAP3 showed that ARFGAP3 siRNA markedly reduced LNCaP cell growth. Androgen receptor (AR)‐dependent transactivation activity on prostate‐specific antigen (PSA) enhancer was synergistically promoted by exogenous ARFGAP3 and paxillin expression, as shown by luciferase assay in LNCaP cells. Thus, our results suggest that ARFGAP3 is a novel androgen‐regulated gene that can promote prostate cancer cell proliferation and migration in collaboration with paxillin.
Mesenchymal–epithelial transitions: Spontaneous and cumulative syntheses of epithelial marker molecules and their assemblies to novel cell junctions connecting human hematopoietic tumor cells to carcinomatoid tissue structures
Authors: Franke Werner W. , Rickelt Steffen
Published: June 2011

Using biochemical as well as light‐ and electron‐microscopic immunolocalization methods, in cultures of unicellular human blood tumor cells, we have studied the phenomenon of spontaneous and cumulative syntheses of certain epithelial proteins and glycoproteins and their assemblies to two major kinds of novel cell–cell junctions, adhering junctions (AJs) and junctions based on the epithelial cell adhesion molecule (EpCAM). More than two decades, we have selected and characterized clonal sublines of multipotential hematopoietic K562 cells, which are enriched in newly formed AJs based on cis‐clusters of desmoglein Dsg2, in some sublines accompanied by desmocollin Dsc2. Both desmosomal cadherins can be anchored in a submembranous plaque containing plakoglobin and plakophilins Pkp2 and Pkp3, with or without other armadillo proteins and desmoplakin. Also, these cells are often connected by an additional, extended junction system, in which the transmembrane epithelial glycoprotein EpCAM is associated with a cytoplasmic plaque rich in several actin‐binding proteins such as afadin, α‐actinin, ezrin and vinculin. Both kinds of junctions contribute to connections of K562 cells into epithelioid monolayers or even three‐dimensional, tissue‐like structures, thus markedly changing the cell biological nature and behavior of the resulting tumor subforms (mesenchymal–epithelial transitions). We discuss molecular mechanisms involved in the formation and function of these junctions, also with respect to tumor spread and metastasis, as well as diagnostic and therapeutic consequences.
Cell adhesion and proliferation studies on semi‐interpenetrating polymeric networks (semi‐IPNs) of polyacrylamide and gelatin
Authors: Jaiswal Maneesh , Koul Veena , Dinda Amit K. , Mohanty Sujata , Jain Krishan Gopal
Published: June 2011

In this study, the effect of feed composition, degree of hydrophilicity, and internal morphology has been investigated for cell proliferation potential of the polyacrylamide/gelatin (PAm/G) semi‐interpenetrating polymeric network (semi‐IPNs). Polycaprolactone diacrylate was used to cross‐link polyacrylamide chains. Scanning electron microscopy (SEM) micrographs demonstrate uniformly distributed porous structure with internal diameter in the range of 75–175 μm, dependent on matrix compositions. Water–air contact angle was found in the range of 49° ± 0.22 to 89° ± 0.14 (p < 0.02) suggesting varying degree of hydrophilicity of the hydrogel surface. In addition, protein adsorption study showed 45 ± 0.14 μg to 64 ± 0.12 μg (p < 0.01) of protein adsorbed per cm2 of hydrogel. Quantitative estimation of cell adhesion and proliferation was carried out by DNA quantification using fluorimetric assay method (p < 0.02). Microscopic images of proliferative cells on semi‐IPNs by fluorescent and inverted phase contrast supported the findings of DNA quantification. Contact angle in the range of 63–69° in association with 52–59 μg/cm2 protein absorption and 115–150 μm pore size was found optimum for fibroblast proliferation on PAm/G semi‐IPN scaffolds. The newly developed semi‐interpenetrating network may serve as a potential scaffold for soft tissue‐engineering applications. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Spatiotemporal control of proliferation and differentiation of bone marrow–derived mesenchymal stem cells recruited using collagen hydrogel for repair of articular cartilage defects
Authors: Mimura Tomohiro , Imai Shinji , Okumura Noriaki , Li Liangman , Nishizawa Kazuya , Araki Susumu , Ueba Hiroaki , Kubo Mitsuhiko , Mori Kanji , Matsusue Yoshitaka
Published: June 2011

Articular cartilage has a poor healing capacity, and cartilage regeneration is not always warranted to achieve healing. On the other hand, collagen scaffolds have been shown to support regeneration of articular cartilage defects in animal models, whereas bone morphogenetic protein‐2 (BMP‐2) is known to cause chondrogenic differentiation of marrow‐derived mesenchymal stem cells (MSCs). The purpose of this study was to evaluate the effectiveness of intra‐articular administration of BMP‐2 into bone marrow–derived MSCs recruited to defects using original collagen hydrogel in rabbits at various time points. Full‐thickness defects were created in both knees, then collagen hydrogels were transplanted, and BMP‐2 was supplied for 1‐week periods, as follows. BMP‐2 was administered immediately after the operation for 1 week (BMP0‐1 group), and BMP‐2 was administered between weeks 1 and 2 after the operation (BMP1‐2 group). BMP2 was administered between weeks 2 and 3 (BMP2‐3 group). Specimens were then obtained, and bromodeoxyuridine (BrdU)–positive cells were enumerated and histologic grading was also performed. In addition, the gene expression analysis was performed using quantitative real‐time reverse transcription polymerase chain reaction (RT‐PCR) assays. Enumeration of BrdU‐positive cells showed a significant increase in the BMP0‐1 group compared with the other groups. Similarly, histologic scores in the BMP0‐1 group were superior for up to 8 weeks. Finally, RT‐PCR findings revealed that immediate BMP‐2 administration enhanced chondrogenic differentiation. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Electrochemical investigation of chromium oxide‐coated Ti‐6Al‐4V and Co‐Cr‐Mo alloy substrates
Authors: Swaminathan Viswanathan , Zeng Haitong , Lawrynowicz Daniel , Zhang Zongtao , Gilbert Jeremy L.
Published: June 2011

Hard coatings for articulating surfaces of total joint replacements may improve the overall wear resistance. However, any coating approach must take account of changes in corrosion behavior. This preliminary assessment analyzes the corrosion kinetics, impedance and mechanical–electrochemical stability of 100 μm thick plasma sprayed chromium oxide (Cr2O3) coatings on bearing surfaces in comparison to the native alloy oxide films on Co‐Cr‐Mo and Ti‐6Al‐6V. Cyclic potentiodynamic polarization, electrochemical impedance spectroscopy, and mechanical abrasion under potentiostatic conditions were performed on coated and substrate surfaces in physiological saline. SEM analysis characterized the coating morphology. The results showed that the corrosion current density values of chromium oxide coatings (0.4–1.2 μA/cm2) were of the same order of magnitude as Ti‐6Al‐4V alloy. Mechanical abrasion did not increase corrosion rates of chromium oxide coatings but did for uncoated Co‐Cr‐Mo and Ti‐6Al‐4V. The impedance response of chromium oxide coatings was very different than Co‐Cr‐Mo and Ti‐6Al‐4V native oxides characterized by a defected coating model. More of a frequency‐independent purely resistive response was seen in mid‐frequency range for the coatings (CPEcoat: 40–280 nF/cm2 (rad/s)1‐α, α: 0.67–0.83) whereas a more capacitive character is seen for Co‐Cr‐Mo and Ti‐6Al‐4V (CPEox around 20 μF/cm2 (rad/s)1‐α, α around 0.9). Pores, interparticle gaps and incomplete fusion typical for thermal spray coatings were present in these oxides which could have influenced corrosion resistance. The coating microstructure could have allowed some fluid penetration. Overall, these coatings appear to have suitable corrosion properties for wear surfaces. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Deproteinized dentin: A favorable substrate to self‐bonding resin cements?
Authors: Barbosa De Souza Fábio , Sinclér Delfino Carina , Lacalle Turbino Míriam , Braz Rodivan
Published: June 2011

The adhesive performance on deproteinized dentin of different self‐adhesive resin cements was evaluated through microtensile bond strength (μTBS) analysis and scanning electron microscopy (SEM). Occlusal dentin of human molars were distributed into different groups, according to the categories: adhesive cementation with two‐step bonding systems—control Groups (Adper Single Bond 2 + RelyX ARC/3M ESPE; One Step Plus + Duolink/Bisco; Excite + Variolink I/Ivoclar Vivadent) and self‐adhesive cementation—experimental groups (Rely X Unicem/3M ESPE; Biscem/Bisco; MultiLink Sprint/Ivoclar Vivadent). Each group was subdivided according to the dentin approach to: α, maintenance of collagen fibers and β, deproteinization. The mean values were obtained, and submitted to ANOVA and Tukey test. Statistical differences were obtained to the RelyX Unicem groups (α = 13.59 MPa; β = 30.19 MPa). All the BIS Group specimens failed before the mechanical tests. Dentinal deproteinization provided an improved bond performance for the self‐adhesive cement Rely X Unicem, and had no negative effect on the other cementing systems studied. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Surface characteristics and biological studies of hydroxyapatite coating by a new method
Authors: Lee Ki‐Won , Bae Cheol‐Min , Jung Jae‐Young , Sim Gi‐Bong , Rautray Tapash Ranjan , Lee Hyo‐Jin , Kwon Tae‐Yub , Kim Kyo‐Han
Published: June 2011

Hydroxyapatite was coated on the Ti implants by a new coating method called low temperature high speed collision (LTHSC). Higher roughness values were estimated in the formed thick coating on the implant surface. While the roughness value was lower than plasma sprayed HA coatings, LTHSC HA‐coated surface showed higher hydrophilicity. The cell proliferation of oseteoblastic cells evaluated by MTT assay showed that HA‐coated surface had significantly higher cell viability than the control. The HA‐coated surface showed higher mean total protein production even though there was no statistical difference between two surfaces. Osteoblast differentiation, ALP activity and expression of differentiation marker genes such as osteopontin and osteocalcin were elevated in the cells cultured on HA‐coated surface and this surface also showed higher collagen protein expression than titanium control. Moreover, in experimental group, BIC values were significantly increased after 12 weeks of implantation and about 30–50% cortical bone‐implant contact was observed. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
The intrinsically high pitting corrosion resistance of mechanically polished nitinol in simulated physiological solutions
Authors: Bai Zhijun , Rotermund Harm H.
Published: June 2011

Nitinol wires have been widely used in many biomedical applications, such as cardiovascular stent due to their superelasticity and shape memory effect. However, their corrosion properties and the related biocompatibility are not well understood, and the reported results are controversial. In this study, we evaluate the pitting corrosion property of nitinol, titanium, nickel, and 316L stainless steel (316LSS) wires with different surface roughnesses in a saline solution at 37°C. The cyclic potentiodynamic polarization results show that mechanically polished nitinol and Ti wires are highly resistant to pitting corrosion, while Ni and 316LSS wires are susceptible to pitting corrosion. Electrochemical impedance spectroscopy is used to study the interface of oxide film/solution and all mechanically polished nitinol wires are covered by 2–3 nm thick films formed under open circuit potential. Furthermore, the electronic structures and semiconducting properties of passive films on nitinol, Ti and Ni wires are studied by Mott–Schottky analysis. Passive films formed on nitinol and Ti exhibit n‐type semiconducting characteristics, whereas films on Ni show p‐type semiconducting characteristics. Scanning Kelvin Microscopy is used to measure the surface potential difference between common inclusions from the nitinol matrix and the results indicate that the inclusions are more electrochemically noble than the nitinol matrix. Band energy theory is used to model the electrochemical interface between the passive films of nitinol and the solution under different applied potential conditions. A mechanism for the strong pitting corrosion resistance of nitinol in saline solution is proposed. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.