bluuebunny/crossref_metadata_2025 huggingface dataset:
Do foreign‐ and U.S.‐born mothers across racial/ethnic groups have a similar risk profile for selected sociodemographic and periconceptional factors?
Authors: Ramadhani Tunu A. , Canfield Mark A. , Farag Noha H. , Royle Marjorie , Correa Adolfo , Waller D. Kim , Scheuerle Angela ,   the National Birth Defects Prevention Study
Published: June 2011

BACKGROUND

We examined differences in selected pregnancy‐related risk factors, including maternal sociodemographic characteristics, health‐related conditions, and periconceptional behavioral factors, among foreign‐born versus U.S.‐born control mothers across race/ethnic groups.

METHODS

We used data from the National Birth Defects Prevention Study, and calculated odds ratios (ORs) and 95% confidence intervals (CIs) of the risk factors, for foreign‐born Hispanic, non‐Hispanic white, non‐Hispanic black, and Asian/Pacific Islander (API) mothers, compared to their U.S.‐born counterparts.

RESULTS

Across all race/ethnic groups, foreign‐born mothers were older and had lower odds of obesity compared to their U.S.‐born counterparts. With the exception of foreign‐born black mothers, foreign‐born mothers from other race/ethnic groups had significantly lower odds of binge drinking during the periconceptional period. Compared to U.S.‐born, foreign‐born Hispanic mothers had twice the odds of gestational diabetes (OR = 2.23; 95% CI = 1.36–3.66). Certain health behaviors were less prevalent in foreign‐born black mothers (e.g., folic acid use; OR = 0.54; 95% CI = 0.31–0.96) and foreign‐born API mothers (e.g., cigarette smoking; OR = 0.10; 95% CI = 0.02–0.48).

CONCLUSIONS

Significant differences in pregnancy related risk factors during the periconceptional period and throughout pregnancy were observed between maternal nativity groups and across race/ethnicity. Prevention efforts for both prepregnancy and after conception should be designed and delivered according to maternal nativity for each racial/ethnic group. Birth Defects Research (Part A), 2011. © 2011 Wiley‐Liss, Inc.
Vitreoscilla hemoglobin expression in engineered Escherichia coli: Improved performance in high cell‐density batch cultivations
Authors: Pablos Tania E. , Mora Eugenio Meza , Le Borgne Sylvie , Ramírez Octavio T. , Gosset Guillermo , Lara Alvaro R.
Published: June 2011

High cell‐density cultivations are the preferred system for biomolecules production by Escherichia coli. It has been previously demonstrated that a strain of E. coli with a modified substrate transport system is able to attain high cell densities in batch mode, due to the very low overflow metabolism displayed. The use of elevated amounts of glucose from the beginning of the cultivation, eliminates the existence of substrate gradients due to deficient mixing at large‐scale. However, the large amounts of oxygen demanded resulted in microaerobic conditions after some hours of cultivation, even at small‐scale. In this work, the effect of expressing the Vitreoscilla hemoglobin (VHb) in the engineered strain during batch cultures using high‐glucose concentrations was tested. Together, the expression of VHb and the modified substrate transport system resulted in a 33% increase of biomass production compared to the parental strain (W3110) lacking the VHb in batch cultivations using 25 g/L of glucose. When 50 g/L of glucose were used, expression of VHb in the modified strain led to 11% higher biomass production compared to W3110. The VHb also increased the growth rates of the strains by about 30% in the aerobic phase and more than 200% in the microaerobic phase of batch cultivation.
Uranium bioremediation in continuously fed upflow sand columns inoculated with anaerobic granules
Authors: Tapia‐Rodriguez Aida , Tordable‐Martinez Virginia , Sun Wenjie , Field James A. , Sierra‐Alvarez Reyes
Published: June 2011

Reductive precipitation of soluble hexavalent uranium (U(VI)) to insoluble tetravalent uranium (U(IV)) containing minerals is one of the more promising approaches to uranium remediation. The objective of this study was to evaluate the long‐term performance of methanogenic granules for the continuous treatment of U(VI). For this purpose, three sand‐packed columns inoculated with anaerobic biofilm were operated with or without ethanol and one column was exposed to nitrate co‐contamination. The columns were operated for 373 days and efficiently removed U (24 mg L−1) in excess of 99.8%. No long‐term benefit of ethanol addition was observed, suggesting that endogenous substrates in the biofilm were sufficient to drive the reduction reactions. Nitrate addition was found to inhibit U(VI) reduction and cause re‐oxidation of some U(IV) deposited in the column. Taken as a whole, the results indicate that methanogenic biofilms can be reliably applied in bioreactor technology for sustained U removal from groundwater. Biotechnol. Bioeng. 2011;108: 2583–2591. © 2011 Wiley Periodicals, Inc.
2D format for screening bacterial cells at the throughput of flow cytometry
Authors: Gordeev Alexander A. , Samatov Timur R. , Chetverina Helena V. , Chetverin Alexander B.
Published: June 2011

We present a method for generating gel‐based unordered 2D arrays of bacterial cells of a very high density, up to 105 cells per mm2. Bacteria in a suspension are focused into a thin layer when the suspension and a dry gel matrix penetrate each other. Formation of a second gel from gel‐forming components contained in the suspension results in immobilization of the cells. The immobilized cells stay alive and can repeatedly divide to produce microcolonies. The method provides for high‐throughput screening and massively parallel analysis of individual cells in large populations, as well as for rapid isolation of rare clones. Biotechnol. Bioeng. 2011;108: 2682–2690. © 2011 Wiley Periodicals, Inc.
Osteogenic response to BMP‐2 of hMSCs grown on apatite‐coated scaffolds
Authors: Davis Hillary E. , Case Erin M. , Miller Stephanie L. , Genetos Damian C. , Leach J. Kent
Published: June 2011

Osteoconductive materials play a critical role in promoting integration with surrounding bone tissue and resultant bone repair in vivo. However, the impact of 3D osteoconductive substrates coupled with soluble signals on progenitor cell differentiation is not clear. In this study, we investigated the influence of bone morphogenetic protein‐2 (BMP‐2) concentration on the osteogenic differentiation of human mesenchymal stem cells (hMSCs) when seeded in carbonated apatite‐coated polymer scaffolds. Mineralized scaffolds were more hydrophilic and adsorbed more BMP‐2 compared to non‐mineralized scaffolds. Changes in alkaline phosphatase (ALP) activity within stimulated hMSCs were dependent on the dose of BMP‐2 and the scaffold composition. We detected more cell‐secreted calcium on mineralized scaffolds at all time points, and higher BMP‐2 concentrations resulted in increased ALP and calcium levels. RUNX2 and IBSP gene expression within hMSCs was affected by both substrate and soluble signals, SP7 by soluble factors, and SPARC by substrate‐mediated cues. The present data indicate that a combination of apatite and BMP‐2 do not simply enhance the osteogenic response of hMSCs, but act through multiple pathways that may be both substrate‐ and growth factor‐mediated. Thus, multiple signaling strategies will likely be necessary to achieve optimal bone regeneration. Biotechnol. Bioeng. 2011;108: 2727–2735. © 2011 Wiley Periodicals, Inc.
Secreted production of collagen‐inspired gel‐forming polymers with high thermal stability in Pichia pastoris
Authors: Silva Catarina I.F. , Teles Helena , Moers Antoine P.H.A. , Eggink Gerrit , de Wolf Frits A. , Werten Marc W.T.
Published: June 2011

Previously, we have shown that gel‐forming triblock proteins, consisting of random coil middle blocks and trimer‐forming (Pro‐Gly‐Pro)9 end blocks, are efficiently produced and secreted by the yeast Pichia pastoris. These end blocks had a melting temperature (Tm) of ∼41°C (at 1.1 mM of protein). The present work reveals that an increase of Tm to ∼74°C, obtained by extension of the end blocks to (Pro‐Gly‐Pro)16, resulted in a five times lower yield and partial endoproteolytic degradation of the protein. A possible cause could be that the higher thermostability of the longer (Pro‐Gly‐Pro)16 trimers leads to a higher incidence of trimers in the cell, and that this disturbs secretion of the protein. Alternatively, the increased length of the proline‐rich (Pro‐Gly‐Pro)n domain may negatively influence ribosomal translation, or may result in, for example, hydrophobic aggregation or membrane‐active behavior owing to the greater number of closely placed proline residues. To discriminate between these possibilities, we studied the production of molecules with randomized end blocks that are unable to form triple helices. The codon‐ and amino acid composition of the genes and proteins, respectively, remained unchanged. As these nontrimerizing molecules were secreted intact and at high yield, we conclude that the impaired secretion and partial degradation of the triblock with (Pro‐Gly‐Pro)16 end blocks was triggered by the occurrence of intracellular triple helices. This degradation was overcome by using a yapsin 1 protease disruptant, and the intact secreted polymer was capable of forming self‐supporting gels of high thermal stability. Biotechnol. Bioeng. 2011;108: 2517–2525. © 2011 Wiley Periodicals, Inc.
Dissolving carbon dioxide in high viscous substrates to accelerate biocatalytic reactions
Authors: Brummund Jan , Meyer Florian , Liese Andreas , Eggers Rudolf , Hilterhaus Lutz
Published: June 2011

Solvent free biotransformation of polyglycerol‐3 and lauric acid yields polyglycerol‐3‐laurate and water. This conversion can be catalyzed by Novozym 435. However, the performance is limited by the viscosity of polyglycerol as well as of polyglycerol‐3‐laurate. A decrease of viscosity by increasing reaction temperature is only possible in a certain temperature range because of the limited stability of the applied enzyme. By dissolving high dense carbon dioxide into the reaction system the viscosity could be reduced, keeping the temperature at an acceptable level at the same time. Thus the reaction rate was increased by a factor of 4 while working at a pressure of 280 bar and 60°C. Biotechnol. Bioeng. 2011;108: 2765–2769. © 2011 Wiley Periodicals, Inc.
Down‐regulation of CD81 tetraspanin in human cells producing retroviral‐based particles: Tailoring vector composition
Authors: Rodrigues A.F. , Guerreiro M.R. , Santiago V.M. , Dalba C. , Klatzmann D. , Alves P.M. , Carrondo M.J.T. , Coroadinha A.S.
Published: June 2011

Retroviral‐derived biopharmaceuticals (RV) target numerous therapeutic applications, from gene therapy to virus‐like particle (rVLP)‐based vaccines. During particle formation, beside the pseudotyped envelope proteins, RV can incorporate proteins derived from the virus producer cells (VPC). This may be detrimental by reducing the amounts of the pseudotyped envelope and/or by incorporating protein capable of inducing immune responses when non‐human VPC are used. Manipulating the repertoire of VPC proteins integrated onto the vector structure is an underexplored territory and should provide valuable insights on potential targets to improve vector pharmacokinetic and pharmacodynamic properties. In this work, human HEK 293 cells producing retrovirus‐like particles (rVLPs) and infectious RV vectors were used to prove the concept of customizing RV composition by manipulating cellular protein content. The tetraspanin CD81 was chosen since it is significantly incorporated in the RV membrane, conferring to the vector significant immunogenicity when used in mice. RNA interference‐mediated by shRNA lentiviral vector transduction was efficiently used to silence CD81 expression (up to 99%) and the rVLPs produced by knocked‐down cells lack CD81. Silenced clones were analyzed for cell proliferation, morphological changes, susceptibility to oxidative stress conditions, and rVLP productivities. The results showed that the down‐regulation of VPC proteins requires close monitoring for possible side effects on cellular production performance. Yet, they confirm that it is possible to change the composition of host‐derived immunogens in RV by altering cellular protein content with no detriment for vector productivity and titers. This constitutes an important manipulation tool in vaccinology—by exploiting the potential adjuvant effect of VPC proteins or using them as fusion agents to other proteins of interest to be exposed on the vector membrane—and in gene therapy, by reducing the immunogenicity of RV‐based vector and enhancing in vivo half‐life. Such tools can also be applied to lentiviral or other enveloped viral vectors. Biotechnol. Bioeng. 2011;108: 2623–2633. © 2011 Wiley Periodicals, Inc.
A novel planar flow cell for studies of biofilm heterogeneity and flow–biofilm interactions
Authors: Zhang Wei , Sileika Tadas S. , Chen Cheng , Liu Yang , Lee Jisun , Packman Aaron I.
Published: June 2011

Biofilms are microbial communities growing on surfaces, and are ubiquitous in nature, in bioreactors, and in human infection. Coupling between physical, chemical, and biological processes is known to regulate the development of biofilms; however, current experimental systems do not provide sufficient control of environmental conditions to enable detailed investigations of these complex interactions. We developed a novel planar flow cell that supports biofilm growth under complex two‐dimensional fluid flow conditions. This device provides precise control of flow conditions and can be used to create well‐defined physical and chemical gradients that significantly affect biofilm heterogeneity. Moreover, the top and bottom of the flow chamber are transparent, so biofilm growth and flow conditions are fully observable using non‐invasive confocal microscopy and high‐resolution video imaging. To demonstrate the capability of the device, we observed the growth ofPseudomonas aeruginosabiofilms under imposed flow gradients. We found a positive relationship between patterns of fluid velocity and biofilm biomass due to faster microbial growth under conditions of greater local nutrient influx, but this relationship eventually reversed because high hydrodynamic shear leads to the detachment of cells from the surface. These results reveal that flow gradients play a critical role in the development of biofilm communities. By providing new capability for observing biofilm growth, solute and particle transport, and net chemical transformations under user‐specified environmental gradients, this new planar flow cell system has broad utility for studies of environmental biotechnology and basic biofilm microbiology, as well as applications in bioreactor design, environmental engineering, biogeochemistry, geomicrobiology, and biomedical research. Biotechnol. Bioeng. 2011;108: 2571–2582. © 2011 Wiley Periodicals, Inc.
Preservation of kidneys from controlled donors after cardiac death
Authors: Wind J , Snoeijs M G J , van der Vliet J A , Winkens B , Christiaans M H L , Hoitsma A J , van Heurn L W E
Published: June 2011

Background

Donation after cardiac death (DCD) expands the pool of donor kidneys, but is associated with warm ischaemic injury. Two methods are used to preserve kidneys from controlled DCD donors and reduce warm ischaemic injury: in situ preservation using a double-balloon triple-lumen catheter (DBTL) inserted via the femoral artery and direct cannulation of the aorta after rapid laparotomy. The aim of this study was to compare these two techniques.

Methods

This was a retrospective cohort study of 165 controlled DCD procedures in two regions in the Netherlands between 2000 and 2006.

Results

There were 102 donors in the DBTL group and 63 in the aortic group. In the aortic group the kidney discard rate was lower (4·8 versus 28·2 per cent; P < 0·001), and the warm (22 versus 27 min; P < 0·001) and the cold (19 versus 24 h; P < 0·001) ischaemia times were shorter than in the DBTL group. Risk factors for discard included preservation with the DBTL catheter (odds ratio (OR) 5·19, 95 per cent confidence interval 1·88 to 14·36; P = 0·001) and increasing donor age (1·05, 1·02 to 1·07; P < 0·001). Warm ischaemia time had a significant effect on graft failure (hazard ratio 1·04, 1·01 to 1·07; P = 0·009), and consequently graft survival was higher in the aortic cannulation group (86·2 per cent versus 76·8 per cent in the DBTL group at 1 year; P = 0·027).

Conclusion

In this retrospective study, direct aortic cannulation appeared to be a better method to preserve controlled DCD kidneys.
Rapid identification and evaluation of antioxidant compounds from extracts of Petasites japonicus by hyphenated‐HPLC techniques
Authors: Kim Sang Min , Kang Suk Woo , Jeon Je‐Seung , Jung Yu‐Jin , Kim Chul Young , Pan Cheol Ho , Um Byung‐Hun
Published: June 2011

Gradient HPLC coupled to Diode Array Detector (DAD), MS/MS and NMR was applied to the rapid structure determination of major compounds of methanol extracts from leaves and roots of Petasites japonicus. The relative antioxidant capacities of the compounds were evaluated by an HPLC system with post‐column on‐line antioxidant detection based on 2,2′‐azinobis‐3‐ethylbenzothiazoline‐6‐sulfonic acid radical scavenging. Six compounds were successfully separated on a reverse‐phase C18 column and were identified as 5‐caffeoylquinic acid (5‐CQA), fukinolic acid (FA), 3,5‐di‐O‐caffeoylquinic acid (3,5‐DCQA), quercetin‐3‐O‐(6″‐acetyl)‐β‐glucopyranoside (QAG), 4,5‐di‐O‐caffeoylquinic acid (4,5‐DCQA) and kaempferol‐3‐O‐(6″‐acetyl)‐β‐glucopyranoside (KAG) by MS/MS and 1H NMR data. Among these compounds, those containing a caffeoyl moiety (5‐CQA, FA, 3,5‐ and 4,5‐DCQA) showed relatively strong radical scavenging capacity, with 3,5‐DCQA having the greatest radical scavenging capacity in leaf (23.09% of total antioxidant capacity) and root (26.47%) extracts. The relative radical scavenging portion of QAG was only 3.41% in the leaves and KAG did not show any radical scavenging activity. These results demonstrate that the hyphenated HPLC techniques can be successfully applied to rapidly identify structures and evaluate antioxidant activities without prior purification of compounds from plant tissues of P. japonicus. Copyright © 2011 John Wiley & Sons, Ltd.
Sensitive, selective and rapid determination of bupropion and its major active metabolite, hydroxybupropion, in human plasma by LC‐MS/MS: application to a bioequivalence study in healthy Indian subjects
Authors: Parekh Jignesh M. , Sutariya Dipen K. , Vaghela Rajendrasinh N. , Sanyal Mallika , Yadav Manish , Shrivastav Pranav S.
Published: June 2011

A sensitive, selective and rapid liquid chromatography tandem mass spectrometry (LC‐MS/MS) method was developed for the simultaneous determination of bupropion (BUP) and its major active metabolite hydroxybupropion (HBUP) in human plasma. Separation of both the analytes and venlafaxine as internal standard (IS) from 50 μL human plasma was carried out by solid‐phase extraction. The chromatographic separation of the analytes was achieved on a Zorbax Eclipse XDB C18 (150 × 4.6 mm, 5 µm) analytical column using isocratic mobile phase consisting of 20 mm ammonium acetate–methanol (10:90, v/v), with a resolution factor of 3.5. The method was validated over a wide dynamic concentration range of 0.1–350 ng/mL for BUP and 0.1–600 ng/mL for HBUP. The matrix effect was assessed by post‐column infusion and the mean process efficiency was 96.08 and 94.40% for BUP and HBUP, respectively. The method was successfully applied to a bioequivalence study of 150 mg BUP (test and reference) extended release tablet formulation in 12 healthy Indian male subjects under fed conditions. Copyright © 2011 John Wiley & Sons, Ltd.
Fine Tuning of a Biological Machine: DnaK Gains Improved Chaperone Activity by Altered Allosteric Communication and Substrate Binding
Authors: Schweizer Regina S. , Aponte Raphael A. , Zimmermann Sabine , Weber Annika , Reinstein Jochen
Published: June 2011

DnaK is a member of the Hsp70 family of molecular chaperones. This molecular machine couples the binding and hydrolysis of ATP to binding and release of substrate proteins. The switches that are involved in allosteric communication within this multidomain protein are mostly unknown. Previous insights were largely obtained by mutants, which displayed either wild‐type activity or reduced folding assistance of substrate proteins. With a directed evolution approach for improved folding assistance we selected a DnaK variant characterized by a glycine to alanine substitution at position 384 (G384A); this resulted in a 2.5‐fold higher chaperone activity in an in vitro DnaK‐assisted firefly luciferase refolding assay. Quantitative biochemical characterization revealed several changes of key kinetic parameters compared to the wild type. Most pronounced is a 13‐fold reduced rate constant for substrate release in the ATP‐bound state, which we assume, in conjunction with the resulting increase in substrate affinity, to be related to improved chaperone activity. As the underlying mechanistic reason for this change we propose an altered interface of allosteric communication of mutant G384A, which is notably located at a hinge position between nucleotide and substrate binding domain.
Enhanced Catalytic Performance by Zirconium Phosphate‐Modified SiO2‐Supported RuCo Catalyst for Fischer–Tropsch Synthesis
Authors: Bae Jong Wook , Park Seon‐Ju , Woo Min Hee , Cheon Joo Young , Ha Kyoung‐Su , Jun Ki‐Won , Lee Dong‐Hyun , Jung Hyun Min
Published: June 2011

Our zirconium phosphate (ZrP)‐promoted Ru/Co/ZrP/SiO2 catalyst reveals a high catalytic activity and stability during Fischer–Tropsch synthesis. Surface modification with ZrP on SiO2 support with an appropriate amount of phosphorous component prevents cobalt particle aggregation and enhances its stability. These positive effects of ZrP are mainly induced by the spatial confinement of cobalt particles in a thermally stable ZrP matrix, and the catalytic performance was greatly improved when the P/(Zr+P) molar ratio was 0.134 on the CoZrP(0.5) catalyst.
Controlled Synthesis of Noble Metallic Dimers and the Influence of Secondary Metals on the Catalytic Activity
Authors: Zheng Zhaoliang , Li Hongfang , Shen Yanhua , Cao Rong
Published: June 2011

To precisely discuss the influence of secondary metals on the whole nanosystem, two different types of Pd/Au dimers are constructed by reducing Au precursors with or without ascorbic acid. The number and size of gold nanoparticles attaching on larger Pd nanocrystals can be roughly controlled. Furthermore, based on electrocatalysis, we find that multidecorated dimers are generally more active than singly decorated ones. Meanwhile, the amount of Au precursor used in preparing multidecorated dimers is found to be very important to the catalytic activity of the as‐prepared catalysts. The performance of the catalyst is enhanced with the increasing of Au precursor when the Au/Pd molar ratio is below 1:4, but hindered when the ratio climbs higher. Finally, this work provides a promising approach in forming hybrid nanocompositions to find an optimized amount of secondary metal, which is of significance in academic and economic fields.
Coordination Power Adjustment of Surface‐Regulating Polymers for Shaping Gold Polyhedral Nanocrystals
Authors: Lee Seon Joo , Park Garam , Seo Daeha , Ka Duyoun , Kim Sang Youl , Chung Im Sik , Song Hyunjoon
Published: June 2011

PVP (poly(vinyl pyrrolidone)) is a common polymer that behaves as a surface‐regulating agent that shapes metal nanocrystals in the polyol process. We have used different polymers containing tertiary amide groups, namely PVCL (poly(vinyl caprolactam)) and PDMAm (poly(N,N‐dimethyl acrylamide)), for the synthesis of gold polyhedrons, including octahedrons, cuboctahedrons, cubes, and higher polygons, under the present polyol reaction conditions. The basicity and surface coordination power of the polymers are in the order of PVCL, PVP, and PDMAm. A correlation is observed between the coordination power of the polymers and the resulting gold nanocrystal size. Strong coordination and electron donation from the polymer functional groups to the gold surface restrict particle growth rates, which leads to small nanocrystals. The use of PVCL can yield gold polyhedral structures with small sizes, which cannot be achieved in the reactions with PVP. Simultaneous hydrolysis of the amide group in PDMAm leads to carboxylate functionality, which is very useful for generating chemical and bioconjugates through the formation of ester and amide bonds.
Investigation of Multiphase Flows on Inclined Plates as Potential Design Tool for Separation Devices
Authors: Repke Jens‐Uwe , Kohrt Martin , Wozny Günter
Published: June 2011

Flüssigkeiten strömen in verfahrenstechnischen Apparaten häufig in Form von Filmen und Rinnsalen. Das grundlegende Verständnis der Stoffübergangsvorgänge in diesen meist unter 1 mm dicken Strömungen ist von wesentlicher Bedeutung für die Auslegung von Apparaten. Dabei können wichtige Erkenntnisse zur Strömungsform und zum Stoffübergang bereits an einfachen Platten gewonnen werden. In Basisuntersuchungen wird der Einfluss von Oberflächenstrukturen auf den Stoffübergang und auf das Strömungsfeld experimentell nachgewiesen. Die Ergebnisse könnten künftig für die Validierung von CFD‐Modellen und die signifikante Weiterentwicklung von eingesetzt werden.
Mining query log graphs towards a query folksonomy
Authors: Francisco Alexandre P. , Baeza‐Yates Ricardo , Oliveira Arlindo L.
Published: June 2011

The human interaction through the web generates both implicit and explicit knowledge. An example of an implicit contribution is searching, as people contribute with their knowledge by clicking on retrieved documents. When this information is available, an important and interesting challenge is to extract relations from query logs, and, in particular, semantic relations between queries and their terms. In this paper, we present and discuss results on query contextualization through the association of tags to queries, that is, query folksonomies. Note that tags may not even occur within the query. Our results rely on the analysis of large query log induced graphs, namely click induced graphs. Results obtained with real data show that the inferred query folksonomy provide interesting insights both on semantic relations among queries and on web users intent.Copyright © 2011 John Wiley & Sons, Ltd.
Primary role of multiparametric flow cytometry in the diagnostic work‐up of indolent clonal mast cell disorders
Authors: Perbellini Omar , Zamò Alberto , Colarossi Sabrina , Zampieri Francesca , Zoppi Francesca , Bonadonna Patrizia , Schena Donatella , Artuso Anna , Martinelli Giovanni , Chilosi Marco , Pizzolo Giovanni , Zanotti Roberta
Published: June 2011

Background:

According to the World Health Organization (WHO) classification the diagnosis of systemic mastocytosis (SM) relies on bone marrow (BM) examination and is based on one major and four minor criteria. Herein, we used WHO criteria to compare flow cytometry (FC) with other available techniques in the diagnosis of SM after BM examination.

Methods:

We analyzed a cohort of 95 patients with suspect SM. All patients underwent comprehensive BM examination by using cytology, immunohistochemistry, FC and molecular study for mutation of c‐Kit and serum tryptase dosage. FC evaluation was based on a combination of monoclonal antibodies, specifically CD25/CD2/CD45/CD34/CD117.

Results:

Seventy‐four out of ninety‐five patients were diagnosed with indolent SM (n = 59) or monoclonal mast cell activation syndrome (n = 15) because satisfying less than 3 minor criteria. Thirty‐nine out of these seventy‐four patients fulfilled the major histological criterion, whereas the presence of a minor criterion was assessed by FC, molecular study, cytology, and tryptase level in 70/74, 52/67, 56/74, and 42/74 patients, respectively.

FC showed higher sensitivity than IHC in detection of CD25+ mast cells (MC) (92.9% vs. 73.8%; P = 0.019), especially in the absence of the major histological criterion (90.5% vs. 47.6%; P = 0.003). Moreover, CD2 expression was documented by FC and IHC in 97.1% and 35.3% of cases, respectively (P < 0.001).

Conclusions:

FC showed the best sensitivity for identifying abnormal MC compared to other techniques, especially in cases with low MC burden. Therefore, we hope for a major role of FC in the diagnostic work‐up of clonal MC disorders. © 2011 International Clinical Cytometry Society
Maturation of shoaling behavior is accompanied by changes in the dopaminergic and serotoninergic systems in zebrafish
Authors: Buske Christine , Gerlai Robert
Published: June 2011

The zebrafish has been one of the preferred vertebrate model organisms of developmental biology, and is becoming an important research tool for behavioral neuroscience and behavior genetics. A prominent feature of zebrafish is their strong shoaling tendency. Most recently, the first study investigating the development of shoaling in zebrafish demonstrated that a few days after hatching zebrafish do not shoal, but that shoaling tendency gradually increases during development. The current study investigates this phenomenon using the nearest neighbor distance, a measure most frequently employed for the quantification of shoal cohesion in fish. We demonstrate that shoal cohesion increases with age, while thigmotaxis, “wall hugging,” does not show a consistent age‐dependent change. The mechanisms underlying the maturation of shoaling are unknown. HPLC analysis of whole brain extracts finds the concentration of dopamine, DOPAC, serotonin, and 5‐HIAA normalized to total brain protein weight to increase with age. Although the behavioral and neurochemical results are only correlative at this point, they may open a new avenue into the investigation of the mechanisms and development of social behavior in zebrafish. © 2011 Wiley Periodicals, Inc. Dev Psychobiol 54:28–35, 2012.
Experimental and Theoretical Study of the Keto–Enol Tautomerization of 3,5‐Dioxopimelates
Authors: Erfle Silke , Reim Stefanie , Michalik Dirk , Jiao Haijun , Langer Peter
Published: June 2011

Substituted 3,5‐dioxopimelic acid diesters, stable 1,3,5,7‐tetracarbonyl derivatives, were prepared by condensation of 1,3‐bis(trimethylsilyloxy)‐1,3‐butadienes with methyl malonyl chloride. The influence of the substituents and the solvent on the keto–enol tautomerization of these compounds was investigated by NMR spectroscopy. For the parent compound, the experimental findings were compared with computational results.
An Original On‐Column Oxidative Cleavage of Vicinal Diols Using Alumina/Potassium Periodate: Application to Sequential Oxidation/Horner–Emmons Reactions
Authors: Dakdouki Saada C. , Villemin Didier , Bar Nathalie
Published: June 2011

An unprecedented simple on‐column solvent‐free oxidative cleavage of vicinal diols in the solid phase using alumina/potassium metaperiodate is described herein. It permits preparation of the corresponding carbonyl compounds with high purity and good to excellent yields requiring only short reaction times. This methodology is then employed in on‐column sequential oxidation/Horner–Emmons reactions for the preparation of selected stilbenes in good yields where both reaction and purification are integrated in a single unit or occur simultaneously permitting the rapid and easy preparation of small samples of pure stilbenes.
Fluvial and slope‐wash erosion of soil‐mantled landscapes: detachment‐ or transport‐limited?
Authors: Pelletier Jon D.
Published: June 2011

Many numerical landform evolution models assume that soil erosion by flowing water is either purely detachment‐limited (i.e. erosion rate is related to the shear stress, power, or velocity of the flow) or purely transport‐limited (i.e. erosion/deposition rate is related to the divergence of shear stress, power, or velocity). This paper reviews available data on the relative importance of detachment‐limited versus transport‐limited erosion by flowing water on soil‐mantled hillslopes and low‐order valleys. Field measurements indicate that fluvial and slope‐wash modification of soil‐mantled landscapes is best represented by a combination of transport‐limited and detachment‐limited conditions with the relative importance of each approximately equal to the ratio of sand and rock fragments to silt and clay in the eroding soil. Available data also indicate that detachment/entrainment thresholds are highly variable in space and time in many landscapes, with local threshold values dependent on vegetation cover, rock‐fragment armoring, surface roughness, soil texture and cohesion. This heterogeneity is significant for determining the form of the fluvial/slope‐wash erosion or transport law because spatial and/or temporal variations in detachment/entrainment thresholds can effectively increase the nonlinearity of the relationship between sediment transport and stream power. Results from landform evolution modeling also suggest that, aside from the presence of distributary channel networks and autogenic cut‐and‐fill cycles in non‐steady‐state transport‐limited landscapes, it is difficult to infer the relative importance of transport‐limited versus detachment‐limited conditions using topography alone. Copyright © 2011 John Wiley & Sons, Ltd.
Experimental analysis of the effectiveness of emergency signage and its implementation in evacuation simulation
Authors: Xie Hui , Filippidis Lazaros , Galea Edwin R , Blackshields Darren , Lawrence Peter J
Published: June 2011

Signage systems play an important role in aiding occupants during both circulation and evacuation. Despite the fact that signage systems are an important component in building wayfinding systems, there is a lack of relevant data regarding how occupants perceive, interpret and use the information conveyed by emergency signage. The effectiveness of signage systems is therefore difficult to assess. In this paper, we address this issue through experimentation. The experiment involved measuring the impact of a signage system on a population of 68 test subjects who were instructed to individually vacate a building as quickly as possible via any means they thought appropriate. The evacuation path involved a number of decision points at which emergency signage was available to identify the appropriate path. Through analysis of video footage and data derived from questionnaires, the number of people who saw and utilised the signage information to assist their egress is determined. The experimental results are used to enhance the existing signage model within the buildingEXODUS software. In particular, the signage detection and acceptance probabilities are assigned values based on the experimental data rather than the ideal values previously used in the model. The impact that the enhanced signage model has on evacuation analysis is demonstrated in a hypothetical evacuation scenario. The enhanced signage model is shown to produce a more conservative lower estimate of expected egress times. Copyright © 2011 John Wiley & Sons, Ltd.
Smoke oxidation kinetics for application to prediction of clean burn patterns
Authors: Hartman J. R. , Beyler A. P. , Riahi S. , Beyler C. L.
Published: June 2011

Smoke deposition patterns are a potentially rich source of information concerning the behavior of a fire. Clean burn patterns are smoke‐free areas where smoke deposits have been oxidized away. In order to predict the formation of clean burn patterns, smoke oxidation kinetics are required. Smoke oxidation kinetics were studied for smokes from acrylonitrile butadiene styrene, polymethylmethacrylate, polypropylene, and gasoline. The fuels were burned below a hood, and smoke samples were collected from the hot gas layer and from the wall surfaces. The smokes from various polymers and gasoline were found to contain no measurable volatile organic chemicals. The kinetics of the smokes from the polymers and gasoline were found to be satisfactorily modeled as first order in both smoke and oxygen with the same kinetic constants for all fuels tested. The activation energy was calculated to be 211 kJ/mol, and the pre‐exponential factor was found to be 4.7 × 1010/s. These kinetic parameters provide a basis for modeling clean burn pattern generation. Copyright © 2011 John Wiley & Sons, Ltd.
Performance Evaluation of Solid Oxide Fuel Cells with Thin Film Electrolyte Fabricated by Binder‐Assisted Slurry Casting
Authors: Guo W. M. , Xiao Y. F. , Liu X. M. , Chen Y. , Li L. J.
Published: June 2011

A gas‐tight yttria‐stabilized zirconia (YSZ) electrolyte film was fabricated on porous NiO–YSZ anode substrates by a binder‐assisted slurry casting technique. The scanning electron microscope (SEM) results showed that the YSZ film was relatively dense with a thickness of 10 μm. La0.8Sr0.2MnO3 (LSM)–YSZ was applied to cathode using a screen‐print technique and the single fuel cells were tested in a temperature range from 600 to 800 °C. An open circuit voltage (OCV) of over 1.0 V was observed. The maximum power densities at 600, 700, and 800 °C were 0.13, 0.44, and 1.1 W cm–2, respectively.
CORAL: Quantitative structure–activity relationship models for estimating toxicity of organic compounds in rats
Authors: Toropova A. P. , Toropov A. A. , Benfenati E. , Gini G. , Leszczynska D. , Leszczynski J.
Published: June 2011

For six random splits, one‐variable models of rat toxicity (minus decimal logarithm of the 50% lethal dose [pLD50], oral exposure) have been calculated with CORAL software (http://www.insilico.eu/coral/). The total number of considered compounds is 689. New additional global attributes of the simplified molecular input line entry system (SMILES) have been examined for improvement of the optimal SMILES‐based descriptors. These global SMILES attributes are representing the presence of some chemical elements and different kinds of chemical bonds (double, triple, and stereochemical). The “classic” scheme of building up quantitative structure–property/activity relationships and the balance of correlations (BC) with the ideal slopes were compared. For all six random splits, best prediction takes place if the aforementioned BC along with the global SMILES attributes are included in the modeling process. The average statistical characteristics for the external test set are the following: n = 119 ± 6.4, R2 = 0.7371 ± 0.013, and root mean square error = 0.360 ± 0.037. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Imaging and assessment of placental function
Authors: Moran Mary , McAuliffe Fionnuala M.
Published: June 2011

The placenta is the vital support organ for the developing fetus. This article reviews current ultrasound (US) methods of assessing placental function. The ability of ultrasound to detect placental pathology is discussed. Doppler technology to investigate the fetal, placental, and maternal circulations in both high‐risk and uncomplicated pregnancies is discussed and the current literature on the value of three‐dimensional power Doppler studies to assess placental volume and vascularization is also evaluated. The article highlights the need for further research into three‐dimensional ultrasound and alternative methods of placental evaluation if progress is to be made in optimizing placental function assessment. © 2011 Wiley Periodicals, Inc. J Clin Ultrasound, 2011
An efficient three‐component synthesis of hexahydroquinoline derivatives in ionic liquid
Authors: Wang Ju‐Xian , Shen Gao‐Ling , Shi Da‐Qing
Published: June 2011

A series of hexahydroquinoline derivatives were synthesized by the three‐component reaction of 5,5‐dimethyl‐3‐aminocyclohex‐2‐enone, aromatic aldehyde, and acyl acetonitrile in ionic liquid without using any catalyst. This protocol has the advantages of easier work‐up, milder reaction conditions, high yields, and environmentally benign procedure. J. Heterocyclic Chem., (2011).
Design and synthesis of novel polycycles based on the 3H‐pyrrolo/6,7‐dihydropyrido[1,2‐a]indole scaffold as templates for pharmaceutical development
Authors: Derudas Marco , Pala Nicolino , Sanna Vanna , Dallocchio Roberto , Dessì Alessandro , Roggio Anna Maria , Sechi Mario
Published: June 2011

In the course of our work aimed at developing novel heterocycles of pharmaceutical interest, we designed and synthesized several polycyclic templates as potential substrates to be used in drug design. We obtained a set of condensed ring systems as versatile structural platforms to generate potential DNA‐interactive agents and/or reversible inhibitors of enzymes such as topoisomerases, poly(ADP‐ribose) polymerase‐1 (PARP‐1), telomerase, and, in particular, cyclin dependent kinases. Herein, we report the design, synthesis, structural investigation, and preliminary DNA‐binding affinity of these heteroaromatic systems. J. Heterocyclic Chem., (2011).
Neurotensin regulates cortical glutamate transmission by modulating N‐methyl‐D‐aspartate receptor functional activity: An in vivo microdialysis study
Authors: Ferraro Luca , Beggiato Sarah , Tomasini Maria Cristina , Fuxe Kjell , Tanganelli Sergio , Antonelli Tiziana
Published: June 2011

The aim of the present in vivo microdialysis study was to investigate whether the tridecapeptide neurotensin (NT) influences the N‐methyl‐D‐aspartate (NMDA) receptor‐mediated increase of cortical glutamate transmission in freely moving rats. Intracortical perfusion with NT influenced local extracellular glutamate levels in a bell‐shaped, concentration‐dependent manner. One hundred and three hundred nanomolar NT concentrations increased glutamate levels (151% ± 7% and 124% ± 3% of basal values, respectively). Higher (1,000 nM) and lower (10 nM) NT concentrations did not alter extracellular glutamate levels. The NT receptor antagonist SR48692 (100 nM) prevented the NT (100 nM)‐induced increase in glutamate levels. NMDA (100 and 500 μM) perfusion induced a concentration‐dependent increase in extracellular glutamate levels, the lower 10 μM NMDA concentration being ineffective. When NT (10 nM, a concentration by itself ineffective) was added in combination with NMDA (100 μM) to the perfusion medium, a significant greater increase in extracellular glutamate levels (169% ± 7%) was observed with respect to the increase induced by NMDA (100 μM) alone (139% ± 4%). SR48692 (100 nM) counteracted the increase in glutamate levels induced by the treatment with NT (10 nM) plus NMDA (100 μM). The enhancement of cortical glutamate levels induced by NMDA (100 and 500 μM) was partially antagonized by the presence of SR48692, at a concentration (100 nM) that by itself was ineffective in modulating glutamate release. These findings indicate that NT plays a relevant role in the regulation of cortical glutamatergic transmission, especially by modulating the functional activity of cortical NMDA receptors. A possible role in glutamate‐mediated neurotoxicity is suggested. © 2011 Wiley‐Liss, Inc.
Quantifying intra‐osseous growth of osteosarcoma in a murine model with radiographic analysis
Authors: Cole Heather A. , Ichikawa Jiro , Colvin Daniel C. , O'Rear Lynda , Schoenecker Jonathan G.
Published: June 2011

The orthotopic murine osteosarcoma model is an excellent representation of the human condition as mice develop rapid growth of ‘primary’ tumor with subsequent lung metastasis. Currently, monitoring tumor growth relies on measuring pulmonary metastases occurring four weeks post injection. Studies show that amputation of the tumor‐bearing limb is required before pulmonary metastases are detectable due to rapid growth causing morbidity. Thus, a method measuring ‘primary’ tumor growth independent of metastasis is required. We hypothesized that serial radiography would allow for longitudinal quantification of ‘primary’ osteosarcoma growth and explored this idea by utilizing the tibial orthotopic model. Tumor growth was monitored weekly by radiography and calipers, and results were compared with µCT and histology. We found that radiographs demonstrate extra and intra‐osseous tumor growth by displaying lytic and blastic lesions and the surrounding radio‐opaque area enlarged significantly (p < 0.0001) allowing for quantification. Additionally, radiographs proved more precise than indirect caliper measurements (intra‐observer error ±6.64%: inter‐observer error ±15.84%). Therefore, we determined that radiography provides accurate, longitudinal quantification of ‘primary’ osteosarcoma tumor that can be performed serially in the same mouse, does not require introduction of bioluminescence to the host or cell, and is more precise than the current caliper method. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29:1957–1962, 2011
Determination of 2‐ethylhexyl nitrate in diesel fuel
Authors: Dvořák Bohuslav , Bajerová Petra , Eisner Aleš , Nykodýmová Olga , Ventura Karel
Published: June 2011

The aim of this study was to develop and validate fast and easily applicable GC/MS assay for the quantification of the substance that increases cetane number in diesel fuel (2‐ethylhexylnitrate, 2‐EHN). These requirements were fulfilled best by a headspace GC‐MS assay with negative chemical ionization with methane (HS‐GC/MS). Chromatographic separation is achieved using a DB5‐MS capillary column after the addition of known amount of internal standard (o‐nitrotoluene). The limit of detection was 0.009% v/v for 2‐EHN and the limit of quantification was 0.03% v/v. The HS‐GC/MS method was applied for the quantification of cetane improver in spiked diesel fuel and real diesel fuel. The method is linear over the studied range (0.03–0.3%, v/v), with satisfactory intra‐ and inter‐assay precision, and the relative standard deviations are lower than 10%. Good accuracy is achieved with bias <10% at all levels tested.
Zinc deprivation inhibits extracellular matrix calcification through decreased synthesis of matrix proteins in osteoblasts
Authors: Alcantara Ethel H. , Lomeda Ria‐Ann R. , Feldmann Joerg , Nixon Graeme F. , Beattie John H. , Kwun In‐Sook
Published: June 2011

Scope: Zinc is implicated as an activator for bone formation, however, its influence on bone calcification has not been reported. This study examined how zinc regulates the bone matrix calcification in osteoblasts.

Methods and Results: Two osteoblastic MC3T3‐E1 cell subclones (SC 4 and SC 24 as high and low osteogenic differentiation, respectively) were cultured in normal osteogenic (OSM), Zinc deficient (Zn–, 1 μM), or adequate (Zn+, 15 μM) media up to 20 days. Cells (SC 4) were also supplemented with (50 μg/mL) or no ascorbic acid (AA) in combination with Zinc treatment. Zn– decreased collagen synthesis and matrix accumulation. Although AA is essential for collagen formation, its supplementation could not compensate for Zinc deficiency‐induced detrimental effects on extracellular matrix mineralization. Zn– also decreased the medium and cell layer alkaline phosphatase ALP activity. This decreased ALP activity might cause the decrease of Pi accumulation in response to Zn–, as measured by von Kossa staining. Ca deposition in cell layers, measured by Alizarin red S staining, was also decreased by Zn–.

Conclusion: Our findings suggest that zinc deprivation inhibits extracellular matrix calcification in osteoblasts by decreasing the synthesis and activity of matrix proteins, type I collagen and ALP, and decreasing Ca and Pi accumulation. Therefore zinc deficiency can be considered as risk factor for poor extracellular matrix calcification.
Affinity of vitamin E analogues for the ubiquinone complex II site correlates with their toxicity to cancer cells
Authors: Neuzil Jiri , Cerny Jiri , Dyason Jeffrey C. , Dong Lan‐Feng , Ralph Stephen J.
Published: June 2011

Scope: Vitamin E (VE) analogues, epitomised by the prototypic α‐tocopheryl succinate (α‐TOS), are potent anti‐cancer agents. α‐TOS has recently been shown to trigger apoptosis by targeting the ubiquinone (UbQ) binding site(s) of the mitochondrial complex II (CII) and to cause excessive production of reactive oxygen species.

Methods and results: We have modelled, using two approaches, a range of VE analogues into the proximal UbQ (Qp) binding site of CII. This study reveals that in both cases, the calculated interaction energies of individual VE analogues correlate (R2 value >0.8) with their toxicity to cancer cells.

Conclusion: These data further support the UbQ site(s) of CII as an important target determining the anti‐cancer activity of VE analogues as well as other emerging anti‐cancer drugs.