bluuebunny/crossref_metadata_2025 huggingface dataset:
Fibronectin activity on substrates with controlled OH density
Authors: Gugutkov Dencho , Altankov George , Rodríguez Hernández José Carlos , Monleón Pradas Manuel , Salmerón Sánchez Manuel
Published: February 2009

Adhesion of human fibroblast to a family of fibronectin (FN) coated model substrates consisting of copolymers of ethyl acrylate and hydroxyl ethylacrylate in different ratios to obtain a controlled surface density of OH groups was investigated. Cell adhesion and spreading surprisingly decreased as the fraction of OH groups on the surface increased. AFM studies of FN conformation revealed formation of a protein network on the more hydrophobic surfaces. The density of this network diminished as the fraction of OH groups in the sample increased, up to a maximal OH concentration at which, instead of the network, only FN aggregates were observed. The kinetics of network development was followed at different adsorption times. Immunofluorescence for vinculin revealed the formation of well‐developed focal adhesion complexes on the more hydrophobic surface (similar to the control glass), which became less defined as the fraction of OH groups increased. Thus, the efficiency of cell adhesion is enhanced by the formation of FN networks on the substrate, directly revealing the importance of the adsorbed protein conformation for cell adhesion. However, cell‐dependent reorganization of substrate‐associated FN, which usually takes place on more hydrophilic substrates (as do at the control glass slides), was not observed in this system, suggesting the increased strength of protein‐to‐substrate interaction. Instead, the late FN matrix formation—after 3 days of culture—was again better pronounced on the more hydrophobic substrates and decreased as the fraction of OH groups increase, which is in a good agreement with the results for overall cell morphology and focal adhesion formation. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Relating cell proliferation to in vivo bone formation in porous Ca/P scaffolds
Authors: van Gaalen Steven M. , de Bruijn Joost D. , Wilson Clayton E. , van Blitterswijk Clemens A. , Verbout Abraham J. , Alblas Jacqueline , Dhert Wouter J. A.
Published: February 2009

Most current methods for cell monitoring on 3D porous scaffolds involve end‐stage investigation of scaffolds. Repeated measurements on scaffolds, without disturbing cell vitality and proliferation, are needed to relate in vitro to in vivo data. Alamar Blue™ was used for this purpose. Two different Ca/P scaffolds were studied, using rat BMSCs with three different seeding densities [2.5 × 104 (SD1), 2.5 × 105 (SD2), 2.5 × 106 (SD3) cells]. Alamar Blue™ readings were done on days 1, 3, 5 and 7. After 7 days all 96 scaffolds (n = 16) were implanted in 16 mice for 4 weeks. Bone histomorphometry was performed. For both scaffolds, seeding efficiencies were highest with SD1 and SD2, cell proliferation was optimal in SD1, whereas SD3 resulted in an initial drop in vital cell number in the first 3 days. In vivo, upscaling from SD1 to SD2 lead to significantly more bone contact% in both scaffolds. Alamar Blue™ was shown to be a valuable tool in relating in vitro to in vivo data. Cell proliferation may differ depending on seeding density and scaffold type used. Seeding more cells may not necessarily result in more in vivo bone contact%. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Nmp4/CIZ suppresses parathyroid hormone‐induced increases in trabecular bone
Authors: Robling Alexander G. , Childress Paul , Yu Jun , Cotte Jessica , Heller Aaron , Philip Binu K. , Bidwell Joseph P.
Published: February 2009

The nucleocytoplasmic shuttling transcription factor Nmp4/CIZ (nuclear matrix protein 4/cas interacting zinc finger protein) is a ubiquitously expressed protein that regulates both cytoplasmic and nuclear activities. In the nucleus, Nmp4/CIZ represses transcription of genes crucial to osteoblast differentiation and genes activated by various anabolic stimuli, including parathyroid hormone (PTH). We investigated the role of Nmp4/CIZ in the PTH‐induced increase in bone by engineering mice with loss‐of‐function mutations in the Nmp4/CIZ gene, and treating 10‐week‐old female mice with anabolic doses of human PTH (1–34) at 30 µg/kg/day, 7 day/week, for 7 weeks or vehicle control. The untreated, baseline phenotype of the Nmp4‐null mice between 8 and 16 weeks of age included a modest but significant increase in bone mineral density (BMD) and bone mineral content (BMC) compared to wild‐type (WT) mice. Type I collagen mRNA expression was moderately elevated in the femurs of the Nmp4‐null mice. The Nmp4 mutant alleles decreased body weight by 4% when expressed on a mixed background but the same alleles on a pure B6 background yielded a significant, 15% increase in body weight among the KO mice, compared to their WT controls. Hormone treatment equally enhanced BMD and BMC over vehicle‐treated mice in both the WT and Nmp4‐null groups but Nmp4‐KO mice exhibited a significantly greater PTH‐induced acquisition of femoral trabecular bone as compared to WT mice. These data support our hypothesis that Nmp4/CIZ is a transcriptional attenuator that suppresses osteoid synthesis and PTH‐mediated acquisition of cancellous bone. J. Cell. Physiol. 219: 734–743, 2009. © 2009 Wiley‐Liss, Inc.
Lysophosphatidic acid‐induced ERK activation and chemotaxis in MC3T3‐E1 preosteoblasts are independent of EGF receptor transactivation
Authors: Karagiosis Sue A. , Chrisler William B. , Bollinger Nikki , Karin Norman J.
Published: February 2009

Bone‐forming osteoblasts and their progenitors are target cells for the lipid growth factor lysophosphatidic acid (LPA) which is produced by degranulating platelets at sites of tissue injury. LPA is a potent inducer of bone cell chemotaxis, proliferation and survival in vitro, and this lipid factor is an attractive candidate to facilitate preosteoblast migration during skeletal regeneration in vivo. In this study we sought to more clearly define the intracellular signaling pathways mediating the effects of LPA on bone cells. LPA‐treated MC3T3‐E1 preosteoblastic cells exhibited a bimodal activation of extracellular signal‐related kinase (ERK1/2) with maximal phosphorylation at 5 and 60 min. MEK1/2 activation was detected within 2.5 min of LPA exposure and remained elevated for at least an hour. ERK1/2 phosphorylation was not coupled to Ras activation or to LPA‐induced elevations in cytosolic Ca2+. While LPA exposure transactivates the EGF receptor in many cell types, LPA‐stimulated ERK1/2 activation in MC3T3‐E1 cells was unaffected by the inhibition of EGF receptor function. ERK isoforms can function as transcription factors and ERK1/2 rapidly accumulated in the nuclei of LPA‐treated cells, a process that was blocked if ERK1/2 phosphorylation was prevented. Blocking ERK1/2 phosphorylation also led to significant decreases in LPA‐induced MC3T3‐E1 cell chemotaxis, while the inhibition of EGF receptor function had no effect on the stimulation of preosteoblast motility by LPA. Our results identify ERK1/2 activation as a mediator of LPA‐stimulated MC3T3‐E1 cell migration that may be relevant to preosteoblast motility and gene expression during bone repair in vivo. J. Cell. Physiol. 219: 716–723, 2009. © 2009 Wiley‐Liss, Inc.
Biosorption of phenolic compounds from aqueous solutions onto chitosan–abrus precatorius blended beads
Authors: Siva Kumar Nadavala , Venkata Subbaiah Munagapati , Subba Reddy Alla , Krishnaiah Abburi
Published: February 2009

BACKGROUND: This research focuses on understanding the biosorption process and developing a cost‐effective technology for the treatment of water contaminated with phenolic compounds (phenol, 2‐chlorophenol and 4‐chlorophenol), which are discharged into the aquatic environment from a variety of sources and are highly toxic. In order to remove phenolic compounds from water, a new biobased sorbent is developed, blending chitosan with abrus precatorius, both naturally occurring biopolymers. The resulting chitosan–abrus precatorius blended beads (CS/Ab) were characterized by Brunauer, Emmett and Teller (BET) analysis, Fourier Transform Infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) techniques under batch equilibrium and column flow experimental conditions. The binding capacity of the biosorbent was investigated as a function of initial pH, contact time, initial concentration of adsorbate and dosage of adsorbent.

RESULTS: The percentage removal of phenol, 2‐CP and 4‐CP increased with increasing adsorbent dose, while the adsorption capacity at equilibrium, qe (mg g−1) (amount of phenol, 2‐CP and 4‐CP loaded per unit weight of adsorbent) decreased. The equilibrium time was found to be 240 min for full equilibration of all adsorbates. Adsorption kinetic and isotherm studies showed that the pseudo‐first‐order model and the Langmuir isotherm were the best choices to describe the adsorption behaviors. The maximum monolayer adsorption capacity of phenol, 2‐CP and 4‐CP on to the (CS/Ab) beads was found to be 156 mg g−1, 204 mg g−1 and 278 mg g−1, respectively.

CONCLUSION: The experimental results suggested that (CS/Ab) blended beads are effective in the removal of phenolic compounds from aqueous medium. Copyright © 2009 Society of Chemical Industry
Microbial conversion of androst‐1,4‐dien‐3,17‐dione by Mucor racemosus to hydroxysteroid‐1,4‐dien‐3‐one derivatives
Authors: Faramarzi Mohammad Ali , Zolfaghary Nadia , Tabatabaei Yazdi Mojtaba , Adrangi Sina , Rastegar Hossein , Amini Mohsen , Badiee Mohsen
Published: February 2009

BACKGROUND: A large number of bacterial, fungal and microalgal species are able to bio‐transform steroid compounds. Among them, fungi from the Mucor genus have been shown to mediate hydroxylation, oxidation, and desaturation by the double bond formation and epoxidation of various steroid substances. Mucor racemocus has not been studied for its ability to modify androst‐1,4‐dien‐3,17‐dione, a pharmaceutically important steroid precursor.

RESULTS: The filamentous fungus M. racemosus was applied for bioconversion of androst‐1,4‐dien‐3,17‐dione (ADD, I) in a 5‐day fermentation. Microbial metabolites were purified chromatographically and identified on the basis of their spectral data as 17β‐hydroxyandrost‐1,4‐dien‐3‐one (II), 14α‐hydroxyandrost‐1,4‐dien‐3,17‐dione (III), 15α‐hydroxyandrost‐1,4‐dien‐3,17‐dione (IV), 15α,17β‐dihydroxyandrost‐1,4‐dien‐3‐one (V), 14α,17β‐dihydroxyandrost‐1,4‐dien‐3‐one (VI), and 6β,17β‐dihydroxyandrost‐1,4‐dien‐3‐one (VII).

CONCLUSION: Observed modifications included hydroxylation at C‐6β, C‐14α, C‐15α positions and 17‐carbonyl reduction. The best fermentation conditions for production of hydroxysteroid‐1,4‐dien‐3‐one derivatives were found to be 25 °C at 150 rpm for 5 days with a substrate concentration of 0.5 g L−1. Copyright © 2009 Society of Chemical Industry
Experimental and neural model analysis of styrene removal from polluted air in a biofilter
Authors: Rene Eldon R. , Veiga María C. , Kennes Christian
Published: February 2009

BACKGROUND:Biofilters are efficient systems for treating malodorous emissions. The mechanism involved during pollutant transfer and subsequent biotransformation within a biofilm is a complex process. The use of artificial neural networks to model the performance of biofilters using easily measurable state variables appears to be an effective alternative to conventional phenomenological modelling.

RESULTS:An artificial neural network model was used to predict the extent of styrene removal in a perlite‐biofilter inoculated with a mixed microbial culture. After a 43 day biofilter acclimation period, styrene removal experiments were carried out by subjecting the bioreactor to different flow rates (0.15–0.9 m3h−1) and concentrations (0.5–17.2 g m−3), that correspond to inlet loading rates up to 1390 g m−3h−1. During the different phases of continuous biofilter operation, greater than 92% styrene removal was achievable for loading rates up to 250 g m−3h−1. A back propagation neural network algorithm was applied to model and predict the removal efficiency (%) of this process using inlet concentration (g m−3) and unit flow (h−1) as input variables. The data points were divided into training (115 × 3) and testing set (42 × 3). The most reliable condition for the network was selected by a trial and error approach and by estimating the determination coefficient (R2) value (0.98) achieved during prediction of the testing set.

CONCLUSION:The results showed that a simple neural network based model with a topology of 2–4–1 was able to efficiently predict the styrene removal performance in the biofilter. Through sensitivity analysis, the most influential input parameter affecting styrene removal was ascertained to be the flow rate. Copyright © 2009 Society of Chemical Industry
Aerobic biodegradation of MtBE in an upflow fixed bed reactor
Authors: Bianchi Emma , Censabella Irene , Fascetti Eugenio
Published: February 2009

BACKGROUND: An aerobic upflow fixed bed reactor (UFBR) was densely colonized by a bacterial consortium, obtained from gasoline polluted waters, able to mineralize MtBE and BTEX. The system was studied in order to determine its capability to degrade the MtBE present in prepared solutions and in real contaminated aquifers and was operating for more than a year.

RESULTS: Efficient colonization of the reactor took about 50 days, utilizing bacteria grown in continuous culture in a fermenter connected to the UFBR. During the study the influence of feed concentration of MtBE, temperature and hydraulic retention time (HRT) was analyzed. The system, running at 18 °C on synthetic medium, was fed at an influent MtBE concentration of 27.8 mg L−1 with HRT of 5 h showing 99.98% of MtBE degradation. When working with polluted groundwater, the system achieved 100% BTEX degradation and 99.34% MtBE degradation.

CONCLUSION: The UFBR was tested on synthetic medium spiked with MtBE and on groundwater contaminated with MtBE and BTEX at concentrations of 50–60 ppm and a few ppm, respectively. The reactor responded efficiently showing great flexibility and capability of adjustment to different operating conditions with MtBE degradation of nearly 100%. Copyright © 2009 Society of Chemical Industry
In situ transmission electron microscopy and ion irradiation of ferritic materials
Authors: Kirk Marquis A. , Baldo Peter M. , Liu Amelia C.Y. , Ryan Edward A. , Birtcher Robert C. , Yao Zhongwen , Xu Sen , Jenkins Michael L. , Hernandez‐Mayoral Mercedes , Kaoumi Djamel , Motta Arthur T.
Published: February 2009

The intermediate voltage electron microscope‐tandem user facility in the Electron Microscopy Center at Argonne National Laboratory is described. The primary purpose of this facility is electron microscopy with in situ ion irradiation at controlled sample temperatures. To illustrate its capabilities and advantages a few results of two outside user projects are presented. The motion of dislocation loops formed during ion irradiation is illustrated in video data that reveals a striking reduction of motion in Fe‐8%Cr over that in pure Fe. The development of extended defect structure is then shown to depend on this motion and the influence of nearby surfaces in the transmission electron microscopy thin samples. In a second project, the damage microstructure is followed to high dose (200 dpa) in an oxide dispersion strengthened ferritic alloy at 500°C, and found to be qualitatively similar to that observed in the same alloy neutron irradiated at 420°C. Microsc. Res. Tech., 2009. © 2009 Wiley‐Liss, Inc.
In situ deformation of thin films on substrates
Authors: Legros Marc , Cabié Martiane , Gianola Daniel S.
Published: February 2009

Metallic thin‐film plasticity has been widely studied by using the difference between the coefficients of thermal expansion of the film and the underlying substrate to induce stress. This approach is commonly known as the wafer curvature technique, based on the Stoney equation, which has shown that thinner films have higher yield stresses. The linear increase of the film strength as a function of the reciprocal film thickness, down to a couple hundred nanometers, has been rationalized in terms of threading and interfacial dislocations. Polycrystalline films also show this kind of dependence when the grain size is larger than or comparable to the film thickness. In situ TEM performed on plan‐view or cross‐section specimens faithfully reproduces the stress state and the small strain levels seen by the metallic film during wafer curvature experiments and simultaneously follows the change in its microstructure. Although plan‐view experiments are restricted to thinner films, cross‐sectional samples where the film is reduced to a strip (or nanowire) on its substrate are a more versatile configuration. In situ thermal cycling experiments revealed that the dislocation/interface interaction could be either attractive or repulsive depending on the interfacial structure. Incoherent interfaces clearly act as dislocation sinks, resulting in a dislocation density drop during thermal cycles. In dislocation‐depleted films (initially thin or annealed), grain boundaries can compensate for the absence of dislocations by either shearing the film similarly to threading dislocations or through fast diffusion processes. Conversely, dislocations are confined inside the film by image forces in the cases of epitaxial interfaces on hard substrates. To increase the amount of strain seen by a film, and to decouple the effects of stress and temperature, compliant substrates can also be used as support for the metallic film. The composite can be stretched at a given temperature using heating/cooling straining holders. Other in situ TEM methods that served to reveal scaling effects are also reviewed. Finally, an alternate method, based on a novel bending holder that can stretch metallic films on rigid substrates, is presented. Microsc. Res. Tech., 2009. © 2009 Wiley‐Liss, Inc.
Implications of an avian‐style respiratory system for gigantism in sauropod dinosaurs
Authors: Perry Steven F. , Christian Andreas , Breuer Thomas , Pajor Nadine , Codd Jonathan R.
Published: February 2009

In light of evidence for avian‐like lungs in saurischian dinosaurs, the physiological implications of cross‐current gas exchange and voluminous, highly heterogeneous lungs for sauropod gigantism are critically examined. At 12 ton the predicted body temperature and metabolic rate of a growing sauropod would be similar to that of a bird scaled to the same body weight, but would increase exponentially as body mass increases. Although avian‐like lung structure would be consistent with either a tachymetabolic‐endothermic or a bradymetabolic‐gigantothermic model, increasing body temperature requires adjustments to avoid overheating. We suggest that a unique sauropod structure/function unit facilitated the evolution of gigantism. This unit consisted of (1) a reduction in metabolic rate below that predicted by the body temperature, akin to thermal adaptation as seen in extant squamates, (2) presence of air‐filled diverticula in the long neck and in the visceral cavity, and (3) low activity of respiratory muscles coupled with the high efficiency of cross‐current gas exchange. J. Exp. Zool. 311A:600–610, 2009. © 2009 Wiley‐Liss, Inc.
Arboreal habitat structure affects the performance and modes of locomotion of corn snakes (Elaphe guttata)
Authors: Astley Henry C. , Jayne Bruce C.
Published: February 2009

Arboreal environments pose many functional challenges for animal locomotion including fitting within narrow spaces, balancing on cylindrical surfaces, moving on inclines, and moving around branches that obstruct a straight path. Many species of snakes are arboreal and their elongate, flexible bodies appear well‐suited to meet many of these demands, but the effects of arboreal habitat structure on the locomotion of snakes are not well understood. We examined the effects of 108 combinations of surface shape (cylinder vs. rectangular tunnel), surface width, incline, and a row of pegs on the locomotion of corn snakes (Elaphe guttata). Pegs allowed the snakes to move on the widest and steepest surfaces that were impassable without pegs. Tunnels allowed the snakes to move on steeper inclines than cylinders with similar widths. The mode of locomotion changed with habitat structure. On surfaces without pegs, most snakes used two variants of concertina locomotion but always moved downhill using a controlled slide. Snakes used lateral undulation on most surfaces with pegs. The detrimental effects of increased uphill incline were greater than those of increased surface width on maximal velocity. Snakes moved faster in tunnels than on cylinders regardless of whether pegs were present. Depending on the surface width, the addition of pegs to horizontal cylinders and tunnels resulted in 8–24‐fold and 1.3–3.1‐fold increases in speed, respectively. Thus, pegs considerably enhanced the locomotor performance of snakes, although similar structures such as secondary branches seem likely to impede the locomotion of limbed arboreal animals. J. Exp. Zool. 311A:207–216, 2009. © 2009 Wiley‐Liss, Inc.
Comparison of toxicity and transfection efficiency of amphiphilic block copolymers and polycationic polymers in striated muscles
Authors: Roques Caroline , Fattal Elias , Fromes Yves
Published: February 2009

Background

Gene delivery using synthetic vectors is frequently based on cationic compounds such as polyethyleneimine (PEI). However, few data have been published on the ability of PEI to mediate transgene expression in muscle tissue. Besides cationic vectors, there is increasing interest focusing on amphiphilic copolymers as gene carriers into striated muscles, although their mechanism of action is unknown.

Methods

Plasmid DNA was associated with three different polymers: the cationic polyethyleneimine and two amphiphilic copolymers displaying few (tetronic 304) or no charges (pluronic L64). The resulting formulations were investigated by dynamic light scattering, laser doppler velocimetry, gel retardation assay and transmission electron microscopy. The toxicity and efficiency of the carriers were assessed in both skeletal and cardiac muscles.

Results

PEI efficiently condenses plasmids into small complexes displaying a positive electrophoretic mobility. However, these PEI/DNA complexes lead to severe side‐effects in vivo. The association between amphiphilic copolymers and DNA leads to no or only partial condensation of plasmids. Moreover, amphiphilic polymers do not interact strongly with DNA and tetronic‐based systems are destabilized with a decreasing pH. Those vectors also display a negative electrophoretic mobility. Thus, characteristics of amphiphilic polymer/DNA systems might be considered unfavourable for transfection. However, safe and rather efficient gene expression was obtained in skeletal muscles, even at low DNA doses, but not in the myocardium.

Conclusions

The present study highlights the interest in amphiphilic carriers for promoting DNA transfection in vivo. Gaining new insights into the properties of these vectors should allow their optimization. Copyright © 2009 John Wiley & Sons, Ltd.
Replacement of sulfur dioxide by lysozyme and oenological tannins during fermentation: influence on volatile composition of white wines
Authors: Sonni Francesca , Cejudo Bastante Maria Jesus , Chinnici Fabio , Natali Nadia , Riponi Claudio
Published: February 2009

BACKGROUND: In recent years the use of sulfur dioxide, a commonly used additive in winemaking, has been questioned because of its toxic effects on human health. Studies have been conducted to find alternatives that can effectively substitute for this additive in all its various technological functions. In previous work, lysozyme and oenological tannins were found as possible substitutes in controlling bacterial undesirable fermentations and phenolic oxidation. However, data on the volatile composition of wines obtained by that protocol are lacking. In this work, the effects on volatile composition of white wines by the substitution of SO2 during fermentation with lysozyme and tannin were studied. At the same time, the technological performance of two strains of yeast that produce low amounts of SO2 were evaluated.

RESULTS: The results showed that both SO2 and lysozyme prevented the development of undesirable bacterial fermentations. The study of volatile compounds shows differences in the alcohol, acid and ester contents among the final products: wines fermented with strain 1042 and lysozyme had higher total alcohol concentration, while the addition of SO2 promoted higher production of 3‐methyl‐1‐butanol, 3‐methylthio‐1‐propanol, phenylethyl alcohol and 4‐hydroxy‐benzenethanol. Esters, as a total, were influenced by the different strain and tannins addition, while amounts of medium‐chain fatty acid ethyl esters and their corresponding fatty acids were found in higher amounts in wines coming from fermentations with lysozyme. The sensory analysis revealed a preference for wines to which lysozyme and tannins had been added.

CONCLUSION: The data suggest that the addition of lysozyme and oenological tannins during alcoholic fermentation could represent a promising alternative to the use of SO2 and for the production of wines with reduced content of SO2. The composition of the volatiles in the final wines was affected by the different vinification protocols (mainly with regards to alcohols and ethyl esters). Copyright © 2009 Society of Chemical Industry
Comparison of physicochemical, microscopic and sensory characteristics of ecologically and conventionally grown crops of two cultivars of tomato (Lycopersicon esculentum Mill.)
Authors: Ordóñez‐Santos Luis Eduardo , Arbones‐Maciñeira Enrique , Fernández‐Perejón José , Lombardero‐Fernández Matilde , Vázquez‐Odériz Lourdes , Romero‐Rodríguez Angeles
Published: February 2009

BACKGROUND: Numerous studies have compared ecologically produced foods with conventionally produced competitors, with contradictory results. In this work we investigated the physicochemical, microscopic and sensory properties of two tomato cultivars (Lladó and Antillas), which were grown both ecologically and conventionally.

RESULTS: The physicochemical variables size, weight, firmness, total acidity, pH, total solids content, lycopene content and CIELab a*, b*, a*/b*, C* and h* were all significantly influenced by cultivar, as were the sensory variables external colour, internal colour, external aroma intensity and flavour persistence. Compared with conventionally grown tomatoes, ecologically grown tomatoes had larger total solids contents and larger values of the CIELab colour parameters b*, C* and h*, but smaller sizes and weights and smaller values of the CIELab parameter ratio a*/b*; however, these physicochemical differences were insufficient for growing method to have a significant influence on any of the sensory attributes that were evaluated. Microscopy showed the influence of cultivar on lycopene content, but no other structural differences were observed between the two cultivars or between tomatoes grown by different methods.

CONCLUSIONS: The statistically significant differences found in this study were mainly between cultivars rather than between tomatoes grown using different management practices. Copyright © 2009 Society of Chemical Industry
Inflammatory cutaneous adverse effects of methylene blue dye injection for lymphatic mapping/sentinel lymphadenectomy
Authors: Bleicher Richard J. , Kloth Dwight D. , Robinson Darlene , Axelrod Peter
Published: February 2009

Background

Methylene blue (MB) dye has been used for lymphatic mapping/sentinel lymphadenectomy (LM/SL) in staging of melanoma and breast cancer. It has been noted to cause skin necrosis, but its more mild adverse effects from intraparenchymal breast injections are not well characterized.

Methods

Patients undergoing LM/SL for breast cancer and melanoma were reviewed, with attention devoted to skin manifestations. Patients undergoing mastectomies were excluded to rule out changes from flap devascularization. All breast patients were injected intraparenchymally.

Results

Ninety‐five patients underwent MB injection during a nationwide shortage of lymphazurin; 78 for breast cancer and 17 for melanoma, with 51 patients undergoing breast conservation (BCT). There was no frank skin necrosis among any of the patients. Six (11.8%) BCT patients demonstrated inflammatory changes. Four patients developed findings indistinguishable from infectious cellulitis, with two developing skin telangiectasias prior to radiotherapy. Two patients had fat necrosis confirmed at the MB injection site away from the surgical site; one on imaging and one by biopsy. Most symptoms resolved after conservative management.

Conclusions

MB dye may cause cutaneous changes more subtle than previously described. Physicians caring for patients having LM/SL using MB should be aware of these effects so that a proper differential diagnosis can be entertained postoperatively. J. Surg. Oncol. 2009;99:356–360. © 2009 Wiley‐Liss, Inc.
The latent structure of the Peritraumatic Dissociative Experiences Questionnaire
Authors: Bryant Richard A. , Brooks Robert , Silove Derrick , Creamer Mark , O'Donnell Meaghan , McFarlane Alexander C. , Marmar Charles R.
Published: February 2009

This paper has been retracted due to a publisher's error: the order of the authors was incorrect. The Editor and Publisher of the Journal of Traumatic Stress apologize to the authors and our readership.
Recent Developments in Lipase‐Catalyzed Synthesis of Polyesters
Authors: Kobayashi Shiro
Published: February 2009

Polyester synthesis by lipase catalyst involves two major polymerization modes: i) ring‐opening polymerization of lactones, and, ii) polycondensation. Ring‐opening polymerization includes the finding of lipase catalyst; scope of reactions; polymerization mechanism; ring‐opening polymerization reactivity of lactones; enantio‐, chemo‐ and regio‐selective polymerizations; and, chemoenzymatic polymerizations. Polycondensation includes polymerizations involving condensation reactions between carboxylic acid and alcohol functional groups to form an ester bond. In most cases, a carboxylic acid group is activated as an ester form, such as a vinyl ester. Many recently developed polymerizations demonstrate lipase catalysis specific to enzymatic polymerization and appear very useful. Also, since lipase‐catalyzed polyester synthesis provides a good opportunity for conducting “green polymer chemistry”, the importance of this is described

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79Br NMR spectroscopy as a practical tool for kinetic analysis
Authors: Chan Si Jia , Howe Andrew G. , Hook James M. , Harper Jason B.
Published: February 2009

79Br NMR spectroscopy has been used to monitor a series of reactions in which the bromide ion is produced, including the Menschutkin reaction of pyridine with a range of substituted benzyl bromides and a Heck coupling process. In cases where the process could also be monitored using 1H NMR spectroscopy, the kinetic analyses using heteronuclear magnetic resonance spectroscopy were shown to be completely consistent. Both the utility of the process in following reactions which may be difficult to analyse using other techniques and the practical limitations associated with solvent choice are discussed. Copyright © 2009 John Wiley & Sons, Ltd.
Implementation of quantitative perfusion imaging using pulsed arterial spin labeling at ultra‐high field
Authors: Gardener A.G. , Gowland P.A. , Francis S.T.
Published: February 2009

This study compares the implementation of the STAR and FAIR pulsed arterial spin labeling (PASL) schemes to form quantitative perfusion maps at ultra‐high field, 7 Tesla (T), and high field, 3T. Phantom experiments were performed to compare the inversion efficiency and profile of the labeling pulses at 7T and 3T and to optimize in‐plane saturation techniques. The perfusion weighted (PW) signal was measured at a range of postlabeling delay times and quantitative perfusion maps were calculated on a voxel‐by‐voxel basis. An increase in PW signal was found with field strength, and together with the increased signal‐to‐noise ratio, this led to improved image signal‐to‐noise and quality of fit of perfusion maps at 7T. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Balanced multipoint displacement encoding for DENSE MRI
Authors: Zhong Xiaodong , Helm Patrick A. , Epstein Frederick H.
Published: February 2009

Displacement encoding with stimulated echoes (DENSE) is a quantitative imaging technique that encodes tissue displacement in the phase of the acquired signal. Various DENSE sequences have encoded displacement using methods analogous to the simple multipoint methods of phase contrast (PC) MRI. We developed general n‐dimension balanced multipoint encoding for DENSE. Using these methods, phase noise variance decreased experimentally by 73.7%, 65.6%, and 61.9% compared with simple methods, which closely matched the theoretical decreases of 75%, 66.7%, and 62.5% for one‐dimensional (1D), 2D, and 3D encoding, respectively. Phase noise covariances decreased by 99.2% and 99.3% for balanced 2D and 3D encoding, consistent with the zero‐covariance prediction. The direction bias inherent to the simple methods was decreased to almost zero using balanced methods. Reduced phase noise and improved displacement and strain maps using balanced methods were visually observed in phantom and volunteer images. Balanced multipoint encoding can also be applied to PC MRI. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Novel reconstruction method for three‐dimensional axial continuously moving table whole‐body magnetic resonance imaging featuring autocalibrated parallel imaging GRAPPA
Authors: Zenge Michael O. , Ladd Mark E. , Quick Harald H.
Published: February 2009

Continuously moving table MR imaging has been successfully evaluated for whole‐body tumor staging and metastasis screening. In previous studies it was demonstrated that three‐dimensional (3D) slab‐selective excitation with lateral readout can provide very efficient k‐space coverage when the longitudinal field of view (FOV) is limited. To reduce respiratory artifacts, data acquisition in the thoracoabdominal region of the patient typically must be performed during one single breath hold. This consequently restricts acquisition time and thus spatial resolution. In this work, a novel reconstruction method is introduced for axial 3D moving table data acquisition with lateral readout. The method features table position correction completely in k‐space and is compatible with autocalibrated parallel imaging (GRAPPA). Parallel imaging can be applied to increase spatial resolution while maintaining the breath‐holding time. A sophisticated protocol for whole‐body moving table MRI was developed. The impact of gradient nonlinearity on the featured imaging method was evaluated in phantom and volunteer experiments. Finally, the protocol was optimized toward minimizing residual artifacts. Moving table whole‐body MRI with lateral readout was performed in 5 healthy volunteers and was compared with lateral readout data acquired with a GRAPPA accelerated protocol providing increased spatial resolution. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Physiological origin of low‐frequency drift in blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI)
Authors: Yan Lirong , Zhuo Yan , Ye Yongquan , Xie Sharon X. , An Jing , Aguirre Geoffrey K. , Wang Jiongjiong
Published: February 2009

We investigated the biophysical mechanism of low‐frequency drift in blood‐oxygen‐level‐dependent (BOLD) functional magnetic resonance imaging (fMRI) (0.00–0.01 Hz), by exploring its spatial distribution, dependence on imaging parameters, and relationship with task‐induced brain activation. Cardiac and respiratory signals were concurrently recorded during MRI scanning and subsequently removed from MRI data. It was found that the spatial distribution of low‐frequency drifts in human brain followed a tissue‐specific pattern, with greater drift magnitude in the gray matter than in white matter. In gray matter, the dependence of drift magnitudes on TE was similar to that of task‐induced BOLD signal changes, i.e., the absolute drift magnitude reached the maximum when TE approached T whereas relative drift magnitude increased linearly with TE. By systematically varying the flip angle, it was found that drift magnitudes possessed a positive dependence on image intensity. In phantom experiments, the observed drift was not only much smaller than that of human brain, but also showed different dependence on TE and flip angle. In fMRI studies with visual stimulation, a strong positive correlation between drift effects at baseline and task‐induced BOLD signal changes was observed both across subjects and across activated pixels within individual participants. We further demonstrated that intrinsic, physiological drift effects are a major component of the spontaneous fluctuations of BOLD fMRI signal within the frequency range of 0.0–0.1 Hz. Our study supports brain physiology, as opposed to scanner instabilities or cardiac/respiratory pulsations, as the main source of low‐frequency drifts in BOLD fMRI. Magn Reson Med 61, 2009. © 2009 Wiley‐Liss, Inc.
MRI contrast using solid‐state, B1‐distorting, microelectromechanical systems (MEMS) microresonant devices (MRDs)
Authors: Ciocan Razvan , Lenkinski Robert E. , Bernstein Jonathan , Bancu Mirela , Marquis Robert , Ivanishev Alex , Kourtelidis Fotini , Matsui Aya , Borenstein Jeffrey , Frangioni John V.
Published: February 2009

Presently, signal generation in MRI depends on the concentration and relaxivity of protons or other MR‐active nuclei, and contrast depends on local differences in signal. In this proof‐of‐principle study, we explore the use of nonchemical, solid‐state devices for generating detectable signal and/or contrast in vitro and in vivo. We introduce the concept of microresonant devices (MRDs), which are micron‐sized resonators fabricated using microelectromechanical systems (MEMS) technology. Fifteen‐micrometer (15‐μm)‐thick, coil MRDs were designed to resonate at the 3T Larmor frequency of protons (127.7 MHz) and were fabricated using tantalum (Ta) oxide thin‐film capacitors and copper‐plated spiral inductors. The performance of MRDs having final diameters of 300, 500, and 1000 μm were characterized in saline using a radio frequency (RF) scanning microscope and a clinical 3T MR scanner. The measured B1 fields of 300 μm to 1000 μm MRDs ranged from 3.25 μT to 3.98 μT, and their quality factors (Q) ranged from 3.9 to 7.2. When implanted subcutaneously in the flank of a mouse, only MRDs tuned to the resonant frequency of protons generated a measurable in vivo B1 field. This study lays the foundation for a new class of solid‐state contrast agents for MRI. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Ultra‐low output impedance RF power amplifier for parallel excitation
Authors: Chu Xu , Yang Xing , Liu Yunfeng , Sabate Juan , Zhu Yudong
Published: February 2009

Inductive coupling between coil elements of a transmit array is one of the key challenges faced by parallel RF transmission. An ultra‐low output impedance RF power amplifier (PA) concept was introduced to address this challenge. In an example implementation, an output‐matching network was designed to transform the drain‐source impedance of the metallic oxide semiconductor field effect transistor (MOSFET) into a very low value for suppressing interelement coupling effect, and meanwhile, to match the input impedance of the coil to the optimum load of the MOSFET for maximizing the available output power. Two prototype amplifiers with 500‐W output rating were developed accordingly, and were further evaluated with a transmit array in phantom experiments. Compared to the conventional 50‐Ω sources, the new approach exhibited considerable effectiveness suppressing the effects of interelement coupling. The experiments further indicated that the isolation performance was comparable to that achieved by optimized overlap decoupling. The new approach, benefiting from a distinctive current‐source characteristic, also exhibited a superior robustness against load variation. Feasibility of the new approach in high‐field MR was demonstrated on a 3T clinical scanner. Magn Reson Med 61, 2009. © 2009 Wiley‐Liss, Inc.
Articular cartilage deformation determined in an intact tibiofemoral joint by displacement‐encoded imaging
Authors: Chan Deva D. , Neu Corey P. , Hull Maury L.
Published: February 2009

This study demonstrates the in vitro displacement and strain of articular cartilage in a cyclically‐compressed and intact joint using displacement‐encoded imaging with stimulated echoes (DENSE) and fast spin echo (FSE). Deformation and strain fields exhibited complex and heterogeneous patterns. The displacements in the loading direction ranged from −1688 to −1481 μm in the tibial cartilage and from −1601 to −764 μm in the femoral cartilage. Corresponding strains ranged from −9.8% to 0.7% and from −4.3% to 0.0%. The displacement and strain precision were determined to be 65 μm and less than 0.2%, respectively. Displacement‐encoded magnetic resonance imaging is capable of determining the nonuniform displacements and strains in the articular cartilage of an intact joint to a high precision. Knowledge of these nonuniform strains is critical for the in situ characterization of normal and diseased tissue, as well as the comprehensive evaluation of repair constructs designed using regenerative medicine. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Feasibility of concurrent dual contrast enhancement using CEST contrast agents and superparamagnetic iron oxide particles
Authors: Gilad Assaf A. , van Laarhoven Hanneke W.M. , McMahon Michael T. , Walczak Piotr , Heerschap Arend , Neeman Michal , van Zijl Peter C.M. , Bulte Jeff W.M.
Published: February 2009

A major challenge for cellular and molecular MRI is to study interactions between two different cell populations or biological processes. We studied the possibility to simultaneously image contrast agents based on two different MRI contrast mechanisms: chemical exchange saturation transfer (CEST) and enhancement of T2 relaxation. Various amounts of superparamagnetic iron oxide (SPIO) nanoparticles were mixed with a fixed concentration (250 μM) of the CEST agent poly‐L‐lysine. T2 maps, CEST maps, and frequency‐dependent saturation spectra were then measured. Color‐coded overlay maps demonstrated the feasibility of concurrent dual contrast enhancement. We found that at concentrations lower than 5 μg(Fe)/mL both contrast agents can be imaged simultaneously. At higher concentrations, the iron‐based agent can be used to “shut off” the signal arising from the CEST agent. These initial findings are a first step toward using dual CEST/T2 contrast imaging for studying multiple cellular or molecular targets simultaneously in vivo. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Nonparametric probabilistic approach of uncertainties for elliptic boundary value problem
Authors: Soize Christian
Published: February 2009

The paper is devoted to elliptic boundary value problems with uncertainties. Such a problem has already been analyzed in the context of the parametric probabilistic approach of system parameters uncertainties or for random media. Model uncertainties are induced by the mathematical–physical process, which allows the boundary value problem to be constructed from the design system. If experiments are not available, the Bayesian approach cannot be used to take into account model uncertainties. Recently, a nonparametric probabilistic approach of both the model uncertainties and system parameters uncertainties has been proposed by the author to analyze uncertain linear and non‐linear dynamical systems. Nevertheless, the use of this concept that has to be developed for dynamical systems cannot directly be applied for elliptic boundary value problem, for instance, for a linear elastostatic problem relative to an elastic bounded domain. We then propose an extension of the nonparametric probabilistic approach in order to take into account model uncertainties for strictly elliptic boundary value problems. The theory and its validation are presented. Copyright © 2009 John Wiley & Sons, Ltd.
Reduced human leukocyte antigen expression in advanced‐stage Ewing sarcoma: implications for immune recognition
Authors: Berghuis Dagmar , de Hooge Alfons SK , Santos Susy J , Horst Danielle , Wiertz Emmanuel J , van Eggermond Marja C , van den Elsen Peter J , Taminiau Antonie HM , Ottaviano Laura , Schaefer Karl‐Ludwig , Dirksen Uta , Hooijberg Erik , Mulder Arend , Melief Cornelis JM , Egeler R Maarten , Schilham Marco W , Jordanova Ekaterina S , Hogendoorn Pancras CW , Lankester Arjan C
Published: February 2009

Ewing sarcoma (EWS) is a tumour most commonly arising in bone, although on occasion in soft tissue, with a poor prognosis in patients with refractory or relapsed disease, despite multimodal therapy. Immunotherapeutic strategies based on tumour‐reactive T and/or natural killer cells may improve the treatment of advanced‐stage EWS. Since cellular immune recognition critically depends on human leukocyte antigen (HLA) expression, knowledge about HLA expression in EWS is crucial in the design of cellular immunotherapeutic strategies. Constitutive and IFNγ‐induced HLA class I expression was analysed in EWS cell lines (n = 6) by flow cytometry, using antibodies against both monomorphic and allele‐specific antigens. Expression of antigen processing pathway components and beta‐2 microglobulin (β2m) was assessed by western blot. Expression of class II transactivator (CIITA), and its contribution to HLA class II expression, was evaluated by qRT‐PCR, transduction assays, and flow cytometry. β2m/HLA class I and class II expression was validated in EWS tumours (n = 67) by immunofluorescence. Complete or partial absence of HLA class I expression was observed in 79% of EWS tumours. Lung metastases consistently lacked HLA class I and sequential tumours demonstrated a tendency towards decreased expression upon disease progression. Together with absent or low constitutive expression levels of specific HLA class I loci and alleles, and differential induction of identical alleles by IFNγ in different cell lines, these results may reflect the existence of an immune escape mechanism. Inducible expression of TAP‐1/‐2, tapasin, LMP‐2/‐7, and the β2m/HLA class I complex by IFNγ suggests that regulatory mechanisms are mainly responsible for heterogeneity in constitutive class I expression. EWSs lack IFNγ‐inducible HLA class II, due to lack of functional CIITA. The majority of EWS tumours, particularly if advanced‐stage, exhibit complete or partial absence of both classes of HLA. This knowledge will be instrumental in the design of cellular immunotherapeutic strategies for advanced‐stage EWS. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.