bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tumor‐derived macrophage migration inhibitory factor modulates the biology of head and neck cancer cells via neutrophil activation
Authors: Dumitru Claudia A. , Gholaman Hossein , Trellakis Sokratis , Bruderek Kirsten , Dominas Nina , Gu Xiang , Bankfalvi Agnes , Whiteside Theresa L. , Lang Stephan , Brandau Sven 
Published: February 2011

AbstractMacrophage migration inhibitory factor (MIF) is an inflammatory cytokine that has been reported to enhance the aggressiveness and metastatic potential of tumor cells. However, the mechanisms through which MIF influences tumor development and progression are not understood. The objectives of our study were to assess the effects of tumor‐derived MIF on neutrophils in head and neck cancer (HNC) and to identify possible feedback effects on tumor cells. To this end, we used an in vitro system to model the interaction between human HNC cells and neutrophils. In addition, we analyzed expression of MIF in tissues from HNC patients in relation to neutrophilic infiltration and clinical parameters. Our results show that human HNC is infiltrated by neutrophils proportional to the levels of tumoral MIF. Strong MIF expression by the tumor is associated with higher lymph node metastasis and reduced survival in HNC patients. In vitro, MIF modulated functions of human neutrophils by inducing chemokine CXC motif receptor 2(CXCR2)‐dependent chemotaxis, enhancing neutrophil survival and promoting release of chemokine C‐C Motif Ligand 4 (CCL4) and matrix metalloprotease 9(MMP9). Further, neutrophils activated with tumor‐derived MIF enhanced migratory properties of HNC cells. In conclusion, our data indicate that the effects of tumor‐derived MIF on neutrophils represent an additional mechanism by which MIF might contribute to tumor progression.
Inactivation of the vitamin D receptor in APCmin/+ mice reveals a critical role for the vitamin D receptor in intestinal tumor growth
Authors: Zheng Wei , Wong Kari E. , Zhang Zhongyi , Dougherty Urzsula , Mustafi Reba , Kong Juan , Deb Dilip K. , Zheng Huachuan , Bissonnette Marc , Li Yan Chun 
Published: February 2011

AbstractEmerging evidence supports an inhibitory role for vitamin D in colorectal carcinogenesis; however, the mechanism remains unclear. The adenomatous polyposis coli (APC)/β‐catenin pathway plays a critical role in colorectal carcinogenesis. The purpose of our study is to explore the interactions of vitamin D and APC/β‐catenin pathways in intestinal tumor development. APCmin/+ mice with genetic inactivation of the vitamin D receptor (VDR) were generated through breeding. Intestinal tumorigenesis was compared between APCmin/+ and APCmin/+VDR−/− mice at different ages. No differences were seen in the number of small intestinal and colonic tumors between APCmin/+ and APCmin/+VDR−/− mice aged 3, 4, 6 and 7 months. The size of the tumors, however, was significantly increased in APCmin/+VDR−/− mice in all age groups. Immunostaining showed significant increases in β‐catenin, cyclin D1, phosphorylated Stat‐3 and MSH‐2 levels and decreases in Stat‐1 in APCmin/+VDR−/− tumors compared to APCmin/+ tumors. These observations suggest that VDR signaling inhibits tumor growth rather than tumor initiation in the intestine. Thus, the increased tumor burden in APCmin/+VDR−/− mice is likely due to the loss of the growth‐inhibiting effect of VDR. This study provides strong evidence for the in vivo relevance of the interaction demonstrated in vitro between the vitamin D and β‐catenin signaling pathways in intestinal tumorigenesis.
Tiled top–down combinatorial pyramids for large images representation
Authors: Goffe Romain , Brun Luc , Damiand Guillaume 
Published: February 2011

AbstractThe uprising number of applications that involve very large images with resolutions greater than 30,000 × 30,000 raises major memory management issues. Firstly, the amount of data usually prevents such images from being processed globally and therefore, designing a global image partition raises several issues. Secondly, a multiresolution approach is necessary since an analysis only based on the highest resolution may miss global features revealed at lower resolutions. This article introduces the tiled top–down pyramidal framework which addresses these two main constraints. Our model provides a full representation of multiresolution images with both geometrical and topological relationships. The advantage of a top–down construction scheme is twofold: the focus of attention only refines regions of interest which results in a reduction of the amount of required memory and in a refinement process that may take into account hierarchical features from previous segmentations. Moreover, the top–down model is combined with decomposition in tiles to provide an accurate memory bounding while allowing global analysis of large images. © 2011Wiley Periodicals, Inc. Int J Imaging Syst Technol, 21, 28–36, 2011.
A factorization‐based approach to photometric stereo
Authors: Julià Carme , Lumbreras Felipe , Sappa Angel D. 
Published: February 2011

AbstractThis article presents an adaptation of a factorization technique to tackle the photometric stereo problem. That is to recover the surface normals and reflectance of an object from a set of images obtained under different lighting conditions. The main contribution of the proposed approach is to consider pixels in shadow and saturated regions as missing data, in order to reduce their influence to the result. Concretely, an adapted Alternation technique is used to deal with missing data. Experimental results considering both synthetic and real images show the viability of the proposed factorization‐based strategy. © 2011 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 21, 115–119, 2011.
Comparisons of Macrophyte Breakdown, Associated Plant Chemistry, and Macroinvertebrates in a Wastewater Dominated Stream
Authors: Nelson S. Mark 
Published: February 2011

AbstractReplacement of native macrophyte species with exotic or invasive ones affects the quality of detritus entering streams and can alter nutrient cycles and community structure in aquatic ecosystems. Decomposition of air‐dried native hardstem bulrush (Schoenoplectus acutus), invasive southern cattail (Typha domingensis), and exotic common reed (Phragmites australis) were studied in an urban stream (Las Vegas, Nevada, USA) using litter bags. Samples were analyzed for dry mass, lignin, nutrients, trace elements, and macroinvertebrates. Litter type and sediment deposited on plant material influenced material loss. Trace elements arsenic and selenium increased in plant material to concentrations considered marginal for ecosystem contamination by exposure day 76. Mercury increases were inconsistent across plant species and did not exceed limits. Bulrush decomposed faster, and tended to have higher selenium concentrations, than did invasive southern cattail and exotic common reed. Macroinvertebrate communities colonizing litter bags were similar across plant litter types, but differed from mesh‐only bags and samples collected with a kick‐net. Macroinvertebrate exclusion resulted in significantly lower loss rates, but functional feeding groups such as shredders were not associated with decomposition differences. The caddisfly, Smicridea, physically modified stem material and aided in processing, but microbes appeared most important in biological material breakdown. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nanostructured titanium promotes keratinocyte density
Authors: Zile Melanie A. , Puckett Sabrina , Webster Thomas J. 
Published: February 2011

AbstractInfection of a transcutaneous orthopedic prosthesis is undesirable and decreases the success rate of an implant. Critical to reducing this infection is to develop materials that can decrease bacteria colonization and/or increase skin growth. Since previous studies have demonstrated significantly less bacteria colonization (yet promoted osteoblast, bone forming cell, functions) on titanium (Ti) with select nanofeatures, the objective of this in vitro study was to determine keratinocyte (skin forming cells) functions on Ti modified to have nanoscale surface features. To further promote keratinocyte functions, some Ti surfaces were functionalized with fibroblast growth factor‐2 (FGF‐2). Nanometer‐sized topographical surface features were created on traditional Ti implants by anodization (termed nanotubular) and electron beam evaporation (termed nanorough). This study found that compared to conventional (nanosmooth) Ti, the nanotubular and nanorough Ti surfaces promoted keratinocyte density. Moreover, when functionalized with FGF‐2, keratinocyte density increased on all surfaces, resulting in the greatest keratinocyte density on nanorough and nanotubular Ti‐functionalized with FGF‐2 after 5 days of culture. Interestingly, keratinocyte densities on nanorough and nanotubular Ti were similar to that achieved on conventional Ti functionalized with FGF‐2. Therefore, when considered in the context of other studies, the results of this in vitro study demonstrated that certain nanometer‐sized Ti topographies may be useful for increasing keratinocyte density while reducing bacteria adhesion and promoting bone tissue formation and, thus, should be further studied for improving the efficacy of various transcutaneous Ti‐based orthopedic implants. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2011.
Skeletal phenotype of the leptin receptor–deficient db/db mouse
Authors: Williams Garry A , Callon Karen E , Watson Maureen , Costa Jessica L , Ding Yaoyao , Dickinson Michelle , Wang Yu , Naot Dorit , Reid Ian R , Cornish Jillian 
Published: February 2011

Abstract
Leptin, a major hormonal product of the adipocyte, regulates appetite and reproductive function through its hypothalamic receptors. The leptin receptor is present in osteoblasts and chondrocytes, and previously we have shown leptin to be an anabolic bone factor in vitro, stimulating osteoblast proliferation and inhibiting osteoclastogenesis. Leptin increases bone mass and reduces bone fragility when administered peripherally but also can indirectly reduce bone mass when administered into the central nervous system. However, data from animal models deficient in either leptin (ob/ob) or its receptor (db/db) remain contradictory. We compared the bone phenotype of leptin receptor–deficient (db/db) and wild-type mice using micro–computed tomographic (µCT) analysis of the proximal tibias and vertebrae. In the tibia, db/db mice had reduced percent trabecular bone volume (13.0 ± 1.62% in wild-type versus 6.01 ± 0.601% in db/db mice, p = .002) and cortical bone volume (411 ± 21.5 µm3 versus 316 ± 3.53 µm3, p = .0014), trabecular thickness (48.4 ± 001.07 µm versus 45.1 ± 0.929 µm, p = .041) and trabecular number (2.68 ± 0.319 mm−1 versus 1.34 ± 0.148 mm−1, p = .0034). In the fifth lumbar vertebral body, the trabecular thickness and cortical thickness were decreased in the db/db versus wild-type mice (0.053 ± 0.0011 mm versus 0.047 ± 0.0013 mm, p = .0002 and 0.062 ± 0.00054 mm versus 0.056 ± 0.0009 mm, p = .0001), respectively, whereas the trabecular and cortical percent bone volume and trabecular number did not reach significance. The total (endosteal and periosteal) cortical perimeter (12.2 ± 0.19 mm versus 13.2 ± 0.30 mm, p = .01) was increased. The serum osteocalcin levels were reduced in the db/db mice, suggesting that bone formation rates are decreased. The material properties of db/db femurs were determined by three-point bending and nanoindentation, showing decreased bone strength (13.3 ± 0.280 N versus 7.99 ± 0.984 N, p = .0074) and material stiffness (28.5 ± 0.280 GPa versus 25.8 ± 0.281 GPa, p &lt; .0001). These results demonstrate that bone mass and strength are reduced in the absence of leptin signaling, indicating that leptin acts in vivo as an anabolic bone factor. This concurs with results of in vitro studies and of peripheral leptin administration in vivo and suggests that leptin's direct effects on bone cells are likely to override its actions via the central nervous system. © 2011 American Society for Bone and Mineral Research
On the sensitivity of rotational CARS N2 thermometry to the Herman–Wallis factor
Authors: Bohlin Alexis , Bengtsson Per‐Erik , Marrocco Michele 
Published: February 2011

AbstractPurely rotational spectral signals of coherent anti‐Stokes Raman scattering (CARS) from nitrogen molecules are studied as a function of the vibration–rotation interaction that weakens the rigid rotor approximation under which the dominant terms of the Raman cross section are calculated. The effect of the vibration–rotation interaction is quantified by means of the Herman–Wallis (HW) factor, and different approaches to its determination are evaluated in terms of their relative contribution to the CARS intensity and thermometric measurements made in a fuel‐rich hydrocarbon flame. Known HW factors are contrasted with more complete expressions of recent derivation, and it is found that relative line strength adjustments amount to about a few percent. Such differences result in temperature corrections of less than 1%. This value should be considered for the definition of the ideal thermometric accuracy of the technique but it is of minor importance in comparison with other sources of uncertainty (e.g. Raman line widths) that emerge from the complexity typical of reactive gas mixtures. Copyright © 2011 John Wiley & Sons, Ltd.
Historical organic dyes: a surface‐enhanced Raman scattering (SERS) spectral database on Ag Lee–Meisel colloids aggregated by NaClO4
Authors: Bruni Silvia , Guglielmi Vittoria , Pozzi Federica 
Published: February 2011

AbstractIn the present study, several natural organic dyes used in antiquity, especially in textile dyeing, were analysed by surface‐enhanced Raman scattering (SERS) spectroscopy, in order to build a wide database that could integrate the data previously published in the literature. In particular, we reported for the first time the SERS spectra of 11 dyes: dragon's blood, sandalwood, annatto, safflower yellow and red, old fustic, gamboge, catechu, kamala, aloe and sap green. Silver colloids (Ag colloids) prepared according to the Lee–Meisel procedure, i.e. by reduction of a silver nitrate (AgNO3) aqueous solution with trisodium citrate dihydrate, were used as substrate. As its efficiency had been tested in a previous work, sodium perchlorate (NaClO4) 1.8Mwas again employed as aggregating agent, giving the best results when added to the silver nanoparticles after the analyte. Copyright © 2011 John Wiley & Sons, Ltd.
Detection of Panax quinquefolius in Panax ginseng using ‘subtracted diversity array’
Authors: Niu Linhai , Mantri Nitin , Li Chun Guang , Xue Charlie , Wohlmuth Hans , Pang Edwin CK 
Published: February 2011

AbstractBACKGROUND: Food adulteration remains a major global concern. DNA fingerprinting has several advantages over chemical and morphological identification techniques. DNA microarray‐based fingerprinting techniques have not been used previously to detect adulteration involving dried commercial samples of closely related species. Here we report amplification of low‐level DNA obtained from dried commercial ginseng samples using the Qiagen™ REPLI‐g® Kit. Further, we used a subtracted diversity array (SDA) to fingerprint the two ginseng species, Panax ginseng and Panax quinquefolius, that are frequently mixed for adulteration.RESULTS: The two ginseng species were successfully discriminated using SDA. Further, SDA was sensitive enough to detect a deliberate adulteration of 10% P. quinquefolius in P. ginseng. Thirty‐nine species‐specific features including 30 P. ginseng‐specific and nine P. quinquefolius‐specific were obtained. This resulted in a feature polymorphism rate of 10.5% from the 376 features used for fingerprinting the two ginseng species. The functional characterization of 14 Panax species‐specific features by sequencing revealed one putative ATP synthase, six putative uncharacterized proteins, and two retroelements to be different in these two species.CONCLUSION: SDA can be employed to detect adulterations in a broad range of plant samples. Copyright © 2011 Society of Chemical Industry
Analysis of saikosaponins in Bupleuri Radix and Caihu‐shugan‐san using reversed‐phase HPLC with pulsed amperometric detection
Authors: Kwon Ha‐Jeong , Sim Hee‐Jung , Lee Sa‐im , Lee Yong‐Moon , Lee Je‐Hyun , Park Yong‐Duk , Hong Seon‐Pyo 
Published: February 2011

AbstractA simple and sensitive reversed‐phase (RP) HPLC coupled with pulsed amperometric detection (PAD) method was developed to determine the saikosaponin content in Bupleuri Radix or Caihu‐shugan‐san. Four saikosaponins in Bupleuri Radix and Caihu‐shugan‐san were extracted with a 6:4 solution of 10 mM sodium phosphate buffer (pH 8)/100% ethanol. Pulsed amperometric detection of carbohydrates in four major saikosaponins was highly sensitive when used with a water–acetonitrile gradient on an alkaline RP column with a post‐column delivery system. The limits of detection (S/N=3) and of quantification (S/N=10) of saikosaponins were 0.01–0.02 and 0.03–0.05 μg/mL, respectively. The intra‐ and inter‐day precision (RSDs) were each <9.7% and the average recoveries were 95.0–97.6% in Bupleuri Radix. This method can be used to analyze saikosaponins in Bupleuri Radix and Caihu‐shugan‐san.
Influence of the bridging azine ligand on the rate of ligand substitution in a series of dinuclear platinum(II) complexes
Authors: Reddy D. , Jaganyi D. 
Published: February 2011

AbstractA series of azine‐bridged dinuclear platinum(II) complexes of the type [{trans‐Pt(NH3)2(OH2)}2(μ‐azn)](ClO4)4(where azn = pyrazine (pzn,Pt1), 2,3‐dimethylpyrazine (2,3‐pzn,Pt2), and 2,5‐dimethylpyrazine (2,5‐pzn,Pt3)) were synthesized to investigate the influence of the bridging azine ligand on the reactivity of the platinum(II) centers. The pKavalues of the complexes were determined via acid–base titration, and the rate of substitution of the aqua moiety by a series of neutral nucleophiles, viz. thiourea (TU), 1,3‐dimethyl‐2‐thiourea (DMTU), and 1,1,3,3‐tetramethyl‐2‐thiourea (TMTU), was determined under pseudo‐first‐order conditions as a function of concentration and temperature using standard spectrophotometric techniques. The introduction of the methyl groups to the bridging azine linker inPt2andPt3leads to a moderate increase in the pKavalues obtained for the first and second deprotonation steps, respectively, as a result of the increased σ‐donor capacity of the bridging azine ligand trans to the aqua moiety. A comparison of the rate constants,k1andk2, at 298 K, obtained for the substitution of the aqua moieties fromPt1,Pt2, andPt3by TU, shows that the introduction of the σ‐donating methyl groups on the bridging azine ligand inPt2andPt3results in a corresponding decrease in the reactivity, by ca. five times for the first substitution step and ca. 10 times for the second substitution step. Density functional theory calculations at the B3LYP/LACVP** level of theory for the complexes demonstrate that the introduction of electron‐donating methyl groups results in (i) increased steric hindrance over the metal centers and (ii) decreased the positive charge on the metal center and increases energy separation of the frontier molecular orbitals (EHOMO–ELUMO) of the ground‐state platinum(II) complexes, leading to a less‐reactive metal center. © 2011 Wiley Peiodicals, Inc. Int J Chem Kinet 43: 161–174, 2011
Chemical wave studies in the bromate–pyrocatechol beads system
Authors: Harati Mohammad , Izadyar Mohammad 
Published: February 2011

AbstractWe studied the chemical wave activity of the pyrocatechol‐acidic bromate system in the presence of ferroin‐loaded beads. The wave activity lasted for more than 24 h while meandering spirals continued for up to 10 h. Rigid and meandering spiral waves were investigated. We have analyzed the wave propagation speed and spiral tip trajectory versus the initial concentrations of all reagents as well as the age of the solution. Wave velocity depends on [H+] and [BrO] concentrations by the relationship v=k[H+]1/2[BrO]1/2, which is in agreement with other studies. This system is ideal to study wave activity and spiral waves as it does not produce precipitates under the studied conditions. © 2011 Wiley Periodicals, Inc. Int J Chem Kinet 43: 198–203, 2011
The application of mass spectrometry in molecular dosimetry: Ethylene oxide as an example
Authors: Wu Kuen‐Yuh , Chiang Su‐Yin , Shih Wei‐Chung , Huang Chih‐Chun Jean , Chen Ming‐Feng , Swenberg James A. 
Published: February 2011

AbstractMass spectrometry plays an increasingly important role in the search for and quantification of novel chemically specific biomarkers. The revolutionary advances in mass spectrometry instrumentation and technology empower scientists to specifically analyze DNA and protein adducts, considered as molecular dosimeters, derived from reactions of a carcinogen or its active metabolites with DNA or protein. Analysis of the adducted DNA bases and proteins can elucidate the chemically reactive species of carcinogens in humans and can serve as risk‐associated biomarkers for early prediction of cancer risk. In this article, we review and compare the specificity, sensitivity, resolution, and ease‐of‐use of mass spectrometry methods developed to analyze ethylene oxide (EO)‐induced DNA and protein adducts, particularly N7‐(2‐hydroxyethyl)guanine (N7‐HEG) and N‐(2‐hydroxyethyl)valine (HEV), in human samples and in animal tissues. GC/ECNCI‐MS analysis after HPLC cleanup is the most sensitive method for quantification of N7‐HEG, but limited by the tedious sample preparation procedures. Excellent sensitivity and specificity in analysis of N7‐HEG can be achieved by LC/MS/MS analysis if the mobile phase, the inlet (split or splitless), and the collision energy are properly optimized. GC/ECNCI‐HRMS and GC/ECNCI‐MS/MS analysis of HEV achieves the best performance as compared with GC/ECNCI‐MS and GC/EI‐MS. In conclusion, future improvements in high‐throughput capabilities, detection sensitivity, and resolution of mass spectrometry will attract more scientists to identify and/or quantify novel molecular dosimeters or profiles of these biomarkers in toxicological and/or epidemiological studies. © 2011 Wiley Periodicals, Inc., Mass Spec Rev 30:733–756, 2011
Update of uremic toxin research by mass spectrometry
Authors: Niwa Toshimitsu 
Published: February 2011

AbstractMass spectrometry (MS) has been successfully applied for the identification and quantification of uremic toxins and uremia‐associated modified proteins. This review focuses on the recent progress in the MS analysis of uremic toxins. Uremic toxins include low‐molecular weight solutes, protein‐bound low‐molecular weight solutes, and middle molecules (peptides and proteins). Based on MS analysis of these uremic toxins, the pathogenesis of the uremic symptoms will be elucidated to prevent and manage the symptoms. Notably, protein‐bound uremic toxins such as indoxyl sulfate, p‐cresyl sulfate, and 3‐carboxy‐4‐methyl‐5‐propyl‐2‐furanpropionic acid have emerged as important targets of therapeutic removal. Hemodialysis even with a high‐flux membrane cannot efficiently remove the protein‐bound uremic toxins because of their high albumin‐binding property. The accumulation of these protein‐bound uremic toxins in the blood of dialysis patients might play an important role in the development of uremic complications such as cardiovascular disease. Indoxyl sulfate is the most promising protein‐bound uremic toxin as a biomarker of progress in chronic kidney disease. Novel dialysis techniques or membranes should be developed to efficiently remove these protein‐bound uremic toxins for the prevention and management of uremic complications. © 2011 Wiley Periodicals, Inc., Mass Spec Rev 30:510–521, 2011