bluuebunny/crossref_metadata_2025 huggingface dataset:
Unexpected Aggregation of Neutral, Xylene‐Cored Dinuclear GdIII Chelates in Aqueous Solution
Authors: Costa Jérôme , Balogh Edina , Turcry Véronique , Tripier Raphaël , Le Baccon Michel , Chuburu Françoise , Handel Henri , Helm Lothar , Tóth Éva , Merbach André E.
Published: June 2006

We have synthesized ditopic ligands L1, L2, and L3 that contain two DO3A3− metal‐chelating units with a xylene core as a noncoordinating linker (DO3A3− = 1,4,7,10‐tetraazacyclododecane‐1,4,7‐triacetate; L1 = 1,4‐bis{[4,7,10‐tris(carboxymethyl)‐1,4,7,10‐tetraazacyclododecane‐1‐yl]methyl}benzene; L2 = 1,3‐bis{[4,7,10‐tris(carboxymethyl)‐1,4,7,10‐tetraazacyclododecane‐1‐yl]methyl}benzene; L3 = 3,5‐bis{[4,7,10‐tris(carboxymethyl)‐1,4,7,10‐tetraazacyclododecane‐1‐yl]methyl}benzoic acid). Aqueous solutions of the dinuclear GdIII complexes formed with the three ligands have been investigated in a variable‐temperature, multiple‐field 17O NMR and 1H relaxivity study. The 17O longitudinal relaxation rates measured for the [Gd2L1–3(H2O)2] complexes show strong field dependence (2.35–9.4 T), which unambiguously proves the presence of slowly tumbling entities in solution. The proton relaxivities of the complexes, which are unexpectedly high for their molecular weight, and in particular the relaxivity peaks observed at 40–50 MHz also constitute experimental evidences of slow rotational motion. This was explained in terms of self‐aggregation related to hydrophobic interactions, π stacking between the aromatic linkers, or possible hydrogen bonding between the chelates. The longitudinal 17O relaxation rates of the [Gd2L1–3(H2O)2] complexes have been analysed with the Lipari–Szabo approach, leading to local rotational correlation times ${\tau {{298\hfill \atop {\rm l}\hfill}}}$ of 150–250 ps and global rotational correlation times ${\tau {{298\hfill \atop {\rm g}\hfill}}}$ of 1.6–3.4 ns (cGd: 20–50 mM), where ${\tau {{298\hfill \atop {\rm l}\hfill}}}$ is attributed to local motions of the Gd segments, while ${\tau {{298\hfill \atop {\rm g}\hfill}}}$ describes the overall motion of the aggregates. The aggregates can be partially disrupted by phosphate addition; however, at high concentrations phosphate interferes in the first coordination sphere by replacing the coordinated water. In contrast to the parent [Gd(DO3A)(H2O)1.9], which presents a hydration equilibrium between mono‐ and dihydrated species, a hydration number of q = 1 was established for the [Ln2L1–3(H2O)2] chelates by 17O chemical shift measurements on Ln = Gd and UV/Vis spectrophotometry for Ln = Eu. The exchange rate of the coordinated water is higher for [Gd2L1–3(H2O)2] complexes (${k{{298\hfill \atop {\rm ex}\hfill}}}$ = 7.5–12.0×106 s−1) than for [Gd(DOTA)(H2O)]−. The proton relaxivity of the [Gd2L1–3(H2O)2] complexes strongly decreases with increasing pH. This is related to the deprotonation of the inner‐sphere water, which has also been characterized by pH potentiometry. The protonation constants determined for this process are logKOH = 9.50 and 10.37 for [Gd2L1(H2O)2] and [Gd2L3(H2O)2], respectively.
Synthesis and Properties of the First Möbius Annulenes
Authors: Ajami Dariush , Hess Kirsten , Köhler Felix , Näther Christian , Oeckler Oliver , Simon Arndt , Yamamoto Chiyo , Okamoto Yoshio , Herges Rainer
Published: June 2006

Heilbronner in 1964 predicted that annulenes with “…︁ a planar perimeter of N=4r AO's, which would yield an open shell configuration when occupied by 4r electrons, can be twisted into a closed shell Möbius strip perimeter without loss in π electron energy”. We have been able to synthesize the first [4n]annulene with such a Möbius topology and now present further Möbius isomers and the details of their preparation as stable compounds. To address the question whether the twist in the π system has an effect on the properties we systematically investigate energy, geometry and magnetic parameters of a large number isomers of [16]annulenes. The Möbius twisted annulenes are consistently more aromatic than the non‐twisted isomers. This is true for the parent as well as our benzoannelated systems. Our results are in contrast to those published recently by C. Castro, W. L. Karney, P. von R. Schleyer et al.
The reliability of fine‐needle aspiration biopsy as the initial diagnostic procedure for palpable masses
Authors: Florentine Barbara D. , Staymates Barry , Rabadi Munif , Barstis John , Black Alexander ,   Cancer Committee of the Henry Mayo Newhall Memorial Hospital
Published: June 2006

BACKGROUND

Fine‐needle aspiration biopsy (FNAB) is a reliable, rapid, minimally invasive alternative to surgical biopsy when it is performed by physician specialists for the diagnosis of palpable masses. FNAB may be under‐utilized in community hospitals in the U.S. because physicians without specialty training commonly provide the service, resulting in less reliable results.

METHODS

Records were reviewed retrospectively from 730 consecutive FNAB cases that were performed and interpreted by expert cytopathologists practicing in an outpatient community hospital setting between 2000 and 2004. Data concerning patient demographics, referring physician specialty type, body sites, diagnoses, specimen adequacy, accuracy of diagnosis, and follow‐up were examined and analyzed.

RESULTS

FNAB was diagnostic in 93% of patients and was 95% accurate. There were 5 false‐negative results and no false‐positive results for the diagnosis of malignancy. The overall sensitivity of FNAB was 93%, and the specificity was 100%. Using either histology or clinical follow‐up, the positive predictive value was 100%, and the negative predictive value was 99%.

CONCLUSIONS

Highly reliable results can be obtained when patients are referred to specialty‐trained cytopathologists practicing in the community for FNAB of palpable mass lesions. Clinicians are encouraged to seek out and support specialized FNAB services in their own communities. Cancer 2006. © 2006 American Cancer Society.
Parallel four‐dimensional Haralick texture analysis for disk‐resident image datasets
Authors: Woods Brent , Clymer Bradley , Heverhagen Johannes , Knopp Michael , Saltz Joel , Kurc Tahsin
Published: June 2006

Texture analysis is one possible method of detecting features in biomedical images. During texture analysis, texture‐related information is found by examining local variations in image brightness. Four‐dimensional (4D) Haralick texture analysis is a method that extracts local variations along space and time dimensions and represents them as a collection of 14 statistical parameters. However, application of the 4D Haralick method on large time‐dependent image datasets is hindered by data retrieval, computation, and memory requirements. This paper describes a parallel implementation using a distributed component‐based framework of 4D Haralick texture analysis on PC clusters. The experimental performance results show that good performance can be achieved for this application via combined use of task‐ and data‐parallelism. In addition, we show that our 4D texture analysis implementation can be used to classify imaged tissues. Copyright © 2006 John Wiley & Sons, Ltd.
Grid benchmarking: vision, challenges, and current status
Authors: Dikaiakos Marios D.
Published: June 2006

Grid benchmarking is an important and challenging topic of Grid computing research. In this paper, we present an overview of the key challenges that need to be addressed for the integration of benchmarking practices, techniques, and tools in emerging Grid computing infrastructures. We discuss the problems of performance representation, measurement, and interpretation in the context of Grid benchmarking, and propose the use of ontologies for organizing and describing benchmarking metrics. Finally, we present a survey of ongoing research efforts that develop benchmarks and benchmarking tools for the Grid. Copyright © 2006 John Wiley & Sons, Ltd.
Complexity, parallel computation and statistical physics
Authors: Machta J.
Published: June 2006

The intuition that a long history is required for the emergence of complexity in natural systems is formalized using the notion of depth. The depth of a system is defined in terms of the number of parallel computational steps needed to simulate it. Depth provides an objective, irreducible measure of history that is applicable to systems of the kind studied in statistical physics. It is argued that physical complexity cannot occur in the absence of substantial depth and that depth is a useful proxy for physical complexity. The ideas are illustrated for a variety of systems in statistical physics. © 2006 Wiley Periodicals, Inc. Complexity 11: 46–64, 2006
The evolution of technology within a simple computer model
Authors: Arthur W. Brian , Polak Wolfgang
Published: June 2006

Technology—the collection of devices and methods available to human society—evolves by constructing new devices and methods from ones that previously exist, and in turn offering these as possible components—building blocks—for the construction of further new devices and elements. The collective of technology in this way forms a network of elements where novel elements are created from existing ones and where more complicated elements evolve from simpler ones. We model this evolution within a simple artificial system on the computer. The elements in our system are logic circuits. New elements are formed by combination from simpler existing elements (circuits), and if a novel combination satisfies one of a set of needs, it is retained as a building block for further combination. We study the properties of the resulting build out. We find that our artificial system can create complicated technologies (circuits), but only by first creating simpler ones as building blocks. Our results mirror Lenski et al.'s: that complex features can be created in biological evolution only if simpler functions are first favored and act as stepping stones. We also find evidence that the resulting collection of technologies exists at self‐organized criticality. © 2006 Wiley Periodicals, Inc. Complexity 11: 23–31, 2006
Relationship between protective effects of rosiglitazone on endothelium and endogenous nitric oxide synthase inhibitor in streptozotocin‐induced diabetic rats and cultured endothelial cells
Authors: Wang Shan , Jiang Jun‐Lin , Hu Chang‐Ping , Zhang Xiao‐Jie , Yang Dong‐Liang , Li Yuan‐Jian
Published: June 2006

Background

Previous investigations have indicated that the level of asymmetric dimethylarginine (ADMA) is increased in diabetic patients and animals, and rosiglitazone has a protective effect on the endothelium. In the present study, we tested the relationship between protective effects of rosiglitazone and ADMA in streptozotocin (STZ)‐induced diabetic rats and cultured endothelial cells.

Methods

Blood samples were collected from carotid artery. Vasodilator responses to acetylcholine (ACh) in the isolated aortic rings were measured, and serum concentrations of glucose, lipid, nitrite/nitrate, ADMA and tumour necrosis factor‐α (TNF‐α) were determined. Cultured endothelial cells were treated with ADMA, and the concentrations of intercellular adhesion molecule (ICAM‐1), TNF‐α, and the activity of nuclear factor‐κB (NF‐κB) were determined.

Results

Vasodilator responses to ACh were decreased markedly and the serum concentrations of TNF‐α, nitrite/nitrate and ADMA were increased significantly in diabetic rats. Rosiglitazone (3, 10 or 30 mg/kg) produced a significant reduction of the inhibition of vasodilator responses to ACh, but had no effect on the serum concentrations of glucose, lipid, nitrite/nitrate and ADMA in diabetic rats. ADMA (30 µM) significantly increased the activity of NF‐κB and elevated the levels of ICAM‐1 and TNF‐α, and pre‐treatment with rosiglitazone (10 or 30 µM) markedly inhibited the increased activity of NF‐κB and reduced the elevated levels of TNF‐α and ICAM‐1 induced by ADMA in cultured endothelial cells.

Conclusions

Rosiglitazone improves endothelial function in diabetic rats, which is related to the reduction of the inflammatory response induced by ADMA. Copyright © 2006 John Wiley & Sons, Ltd.
Cell and molecular regulation of the mouse blastocyst
Authors: Yamanaka Yojiro , Ralston Amy , Stephenson Robert O. , Rossant Janet
Published: June 2006

Animals use diverse strategies to specify tissue lineages during development. A common strategy is to partition maternally supplied and localized lineage determinants into progenitor cells. The mouse embryo appears to use a different, more regulative strategy to specify the first three lineages: the epiblast (EPI: future embryo), the trophectoderm (TE: future placenta), and the primitive endoderm (PE: future yolk sac). These lineages are specified during two successive differentiation steps leading to formation of the blastocyst. Here, we review classic and contemporary models of early lineage specification in the mouse, and describe recent efforts to understand the molecular regulation of these events. We describe evidence that trophectoderm differentiation bears resemblance to the process of epithelialization and describe the importance of apical/basal protein complexes in regulating this process. Next, we present a revised model of PE specification, and describe evidence that PE cells in the inner cell mass sort out to occupy their ultimate position on the surface of the EPI. Finally, we describe factors that reinforce these lineages and three distinct stem cell types that can be isolated from them. Together, these mechanisms guide the differentiation of the first lineages of the mouse and thereby set up tissues that will be important for the first steps of embryonic body patterning. Developmental Dynamics 235:2301–2314, 2006. © 2006 Wiley‐Liss, Inc.
BMP induction of cardiogenesis in P19 cells requires prior cell–cell interaction(s)
Authors: Angello John C. , Kaestner Stefanie , Welikson Robert E. , Buskin Jean N. , Hauschka Stephen D.
Published: June 2006

Mouse P19 embryonal carcinoma cells undergo cardiogenesis in response to high density and DMSO. We have derived a clonal subline that undergoes cardiogenesis in response to high density, but without requiring exposure to DMSO. The new subline retains the capacity to differentiate into skeletal muscle and neuronal cells in response to DMSO and retinoic acid. However, upon aggregation, these Oct 4‐positive cells, termed P19‐SI because they “self‐induce” cardiac muscle, exhibit increased mRNAs encoding the mesodermal factor Brachyury, cardiac transcription factors Nkx 2.5 and GATA 4, the transcriptional repressor Msx‐1, and cytokines Wnt 3a, Noggin, and BMP 4. Exposure of aggregated P19‐SI cells to BMP 4, a known inducer of cardiogenesis, accelerates cardiogenesis, as determined by rhythmic beating and myosin staining. However, cardiogenesis is severely inhibited when P19‐SI cells are aggregated in the presence of BMP 4. These results demonstrate that cell–cell interaction is required before P19‐SI cells can undergo a cardiogenic response to BMP 4. A concurrent increase in the expression of Msx‐1 suggests one possible process underlying the inhibition of cardiogenesis. The phenotype of P19‐SI cells offers an opportunity to explore new aspects of cardiac induction. Developmental Dynamics 235:2122–2133, 2006. © 2006 Wiley‐Liss, Inc.
Meta‐analysis of the nonword reading deficit in specific reading disorder
Authors: Herrmann Julia A. , Matyas Tom , Pratt Chris
Published: June 2006

A meta‐analysis was conducted to investigate whether specific reading disorder (SRD) groups demonstrate a deficit in using phonological recoding strategies. Thirty‐four studies were reviewed that had compared the nonword reading performances of SRD groups with reading‐level matched (RL) control groups. The average nonword reading difference between groups across the total number of studies was moderate (d=0.65, N=2865). Three predictors of the size of group differences in nonword reading ability were identified. Studies that used passage reading tests to match groups for reading level found significantly less evidence for nonword reading deficits than studies that used word‐level reading accuracy tests. Secondly, there was a significant positive relationship between group differences in intelligence level (SRD‐RL control group) and effect sizes. Finally, group differences in age showed a significant negative association with effect magnitudes. The mean age, reading level and intelligence level of groups did not significantly predict nonword reading outcomes. It was concluded that there was evidence for nonword reading deficits in SRD groups, consistent with the claim that deficient development of phonological recoding strategies is a leading cause of reading difficulties. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis of Polyether Cyclophanes through Rhodium‐Catalyzed Cross‐Alkyne Cyclotrimerization
Authors: Tanaka Ken , Sagae Hiromi , Toyoda Kazuki , Noguchi Keiichi
Published: June 2006

Cross‐cyclotrimerizations of ether‐linked α,ω‐diynes and dimethyl acetylenedicarboxylate in the presence of a catalytic amount of cationic rhodium(I)/H8‐BINAP complex give [7]–[21]polyether cyclophanes in good yield. [8]–[9]Ester cyclophanes were also synthesized from the corresponding α,ω‐diynes. The ratio of para‐, meta‐, and orthocyclophanes depends on the length and the structure of the α,ω‐diyne tether chain, whilst the effect of concentration on the yield of polyether cyclophanes appears to be small. X‐ray analysis revealed that a single crystal of [15]metacyclophane 4g was the chiral form and that of [5.5]metacyclophane 4k the racemic form, due to an absence of ring flip in the crystals. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Observer‐independent analysis of high‐resolution MR images of the human cerebral cortex: In vivo delineation of cortical areas
Authors: Walters Nathan B. , Eickhoff Simon B. , Schleicher Axel , Zilles Karl , Amunts Katrin , Egan Gary F. , Watson John D.G.
Published: June 2006

Using high‐resolution MRI, it is now possible to examine the living human cortex down to a resolution of less than 300 μm. Thus, in vivo imaging is now approaching the resolution that has been successfully used in histological analysis of the cerebral cortex for many years, e.g., low‐magnification light microscopy. This allows unprecedented views of cortical microstructure that reflect defined histological features, specifically, individual cortical layers. As in histological brain mapping, it is possible to use the changes in the cortical lamination patterns to define individual cortical areas. This allows in vivo neuroanatomical maps to be generated for individual subjects and precise correlation of the results from functional imaging studies in these subjects with their own microanatomical information. To this end, we adapted the well‐established observer‐independent cytoarchitectonic mapping techniques for defining cortical borders based on changes in cortical lamination for in vivo parcellation of high‐resolution structural MR images. Hum. Brain Mapping, 2007. © 2006 Wiley‐Liss, Inc.
Dose‐dependent attenuation of auditory phantom perception (tinnitus) by PET‐guided repetitive transcranial magnetic stimulation
Authors: Plewnia Christian , Reimold Matthias , Najib Arif , Brehm Bernhard , Reischl Gerald , Plontke Stefan K. , Gerloff Christian
Published: June 2006

Recent data suggest that chronic tinnitus is a “phantom auditory perception” caused by maladaptive neuroplasticity and subsequent hyperactivity in an extended neuronal network including the primary auditory cortex, higher‐order association areas, and parts of the limbic system. It was suggested that attenuation of this tinnitus‐associated hyperactivity may offer a rational option for lasting tinnitus reduction. Here, we tested the hypothesis that tinnitus loudness can be attenuated by low‐frequency repetitive transcranial magnetic stimulation (rTMS) individually navigated to cortical areas with excessive tinnitus‐related activity as assessed by [15O]H2O positron‐emission tomography (PET). Nine patients with chronic tinnitus underwent this combined functional imaging and rTMS‐study. Group analysis of the PET data showed tinnitus‐related increases of regional cerebral blood flow in the left middle and inferior temporal as well as right temporoparietal cortex and posterior cingulum. Repetitive TMS was performed at 1 Hz and 120% of the motor threshold for 5, 15, and 30 min, navigated to the individual maximum of tinnitus‐related cortical hyperactivity. A noncortical stimulation site with the same distance to the ear served as sham control. Tinnitus loudness was reduced after temporoparietal, PET‐guided low‐frequency rTMS. This reduction, lasting up to 30 min, was dependent on the number of stimuli applied, differed from sham stimulation, and was negatively correlated with the length of the medical history of tinnitus in our patients. These data show the feasibility and effectiveness of rTMS guided by individual functional imaging to induce a lasting, dose‐dependent attenuation of tinnitus. Of note, these effects were related to stimulation of cortical association areas, not primary auditory cortex, emphasizing the crucial role of higher‐order sensory processing in the pathophysiology of chronic tinnitus. Hum Brain Mapp, 2007. © 2006 Wiley‐Liss, Inc.
The influences of thermophysical properties of porous media on superadiabatic combustion with reciprocating flow
Authors: Du Liming , Xie Maozhao
Published: June 2006

The influences of thermophysical properties of porous media on superadiabatic combustion with reciprocating flow is numerically studied in order to improve the understanding of the complex heat transfer and optimum design of the combustor. The heat transfer performance of a porous media combustor strongly depends on the thermophysical properties of the porous material. In order to explore how the material properties influence reciprocating superadiabatic combustion of premixed gases in porous media (short for RSCP), a two‐dimensional mathematical model of a simplified RSCP combustor is developed based on the hypothesis of local thermal non‐equilibrium between the solid and the gas phases by solving separate energy equations for these two phases. The porous media is assumed to emit, absorb, and isotropically scatter radiation. The finite‐volume method is used for computing radiation heat transfer processes. The flow and temperature fields are calculated by solving the mass, moment, gas and solid energy, and species conservation equations with a finite difference/control volume approach. Since the mass fraction conservation equations are stiff, an operator splitting method is used to solve them. The results show that the volumetric convective heat transfer coefficient and extinction coefficient of the porous media obviously affect the temperature distributions of the combustion chamber and burning speed of the gases, but thermal conductivity does not have an obvious effect. It indicates that convective heat transfer and heat radiation are the dominating ways of heat transfer, while heat conduction is a little less important. The specific heat of the porous media also has a remarkable impact on temperature distribution of gases and heat release rate. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(5): 336–350, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20120
Advanced 3‐D CPC solar collector for thermal electric system
Authors: Saitoh Takeo S. , Kato Jun , Yamada Noboru
Published: June 2006

In this paper, the authors propose an innovative non‐tracking three‐dimensional compound parabolic concentrator (3‐D CPC) solar collector, which has excellent thermal efficiency for a high‐temperature range (100–200°C). In the past studies, in order to improve the thermal efficiency of the solar collector in a high‐temperature range, very high concentration ratios and tracking systems have been adopted. However, conventional high concentration solar collectors are not cost‐effective and are inappropriate for small‐rating thermal electric generation systems for residential use. The proposed 3‐D CPC collector has a moderate concentration ratio and does not need tracking. Initially, the tentative 3‐D CPC collector was fabricated and its thermal performance was tested. Next, numerical simulations of the optical characteristics of the 3‐D CPC collector were carried out via the ray‐tracing method. Finally, the specification of the optimal 3‐D CPC collector was clarified. Applications of the thermal electric system will also be mentioned. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(5): 323–335, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20121
Internal gravity wave resonance of thermal convection fields in a square cavity with heat‐flux vibration
Authors: Matsumura Shota , Ishida Hideshi , Kimoto Hideo
Published: June 2006

In this paper, the thermal convection field and its resonance phenomena in a square cavity with sinusoidal heat‐flux vibration were numerically investigated. As the angular velocity ω is changed, the thermal convection field at Pr = 0.71,Ra = 106 is found to be classified into 5 regions. In particular, the field has the local maximum relative amplitude of midplane Nusselt's number at ωc = 350, which corresponds to the angular velocity of internal gravity wave ωr estimated by a theoretical equation proposed by Thorpe. This shows that the local enhancement is induced by internal gravity wave resonance. Such correspondence is observed for Ra ≥ 105,Ra ≥ 106 for Pr = 0.71, 7.1, respectively. For these ranges of Ra we propose a correlation equation, a function of Pr and Gr only, to estimate the resonant angular velocity. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(5): 309–322, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20122
Quetiapine versus olanzapine for the treatment of negative symptoms in patients with schizophrenia
Authors: Sirota Pinkhas , Pannet Irit , Koren Ady , Tchernichovsky Eleonora
Published: June 2006

Negative symptoms are considered the most debilitating and refractory aspect of schizophrenia, being associated with poor social, occupational and global outcomes. Conventional antipsychotics have limited efficacy against these symptoms and poor tolerability profiles. Atypical antipsychotics are an alternative treatment, and this 12‐week, randomised, flexibly dosed study compared the efficacy, safety and tolerability of quetiapine and olanzapine in this regard. Of the 40 patients who entered the study (32 male; 8 female), 19 were randomised to quetiapine (mean dose 637 mg/day, mean treatment duration 80 days) and 21 to olanzapine (mean dose 16 mg/day, mean treatment duration 78 days). Quetiapine and olanzapine were similarly effective: in each treatment group significant improvements at Week 12 were observed for negative symptom scores on the SANS and the PANSS, and for subscale scores of affective flattening and alogia on the SANS. Both treatments were well tolerated in this patient population, with no worsening of extrapyramidal symptoms in either case. Anxiety and insomnia were the most common adverse events (≥7% of patients in each group), but were not drug‐related. Although this is a small study with limited power, the results support the effectiveness of quetiapine and olanzapine in treating the negative symptoms of schizophrenia. Copyright © 2006 John Wiley & Sons, Ltd.
Loss of proline‐rich tyrosine kinase 2 function induces spreading and motility of epithelial prostate cells
Authors: de Amicis Francesca , Lanzino Marilena , Kisslinger Annamaria , Calì Gaetano , Chieffi Paolo , Andò Sebastiano , Mancini Francesco Paolo , Tramontano Donatella
Published: June 2006

Although prostate carcinoma is an aggressive cancer preferentially metastasizing to the bones, many prostate tumors remain localized and confined to the prostate indefinitely. Prediction of the behavior of anatomically localized and moderately differentiated prostate tumors remains difficult because of lack of prognostic markers. Cell motility is an important step in the progression of epithelial tumor toward invasive metastatic carcinomas and changes in the expression and function of adhesion molecules contribute to the acquisition of a more malignant phenotype. Proline‐rich tyrosine kinase 2 (Pyk2) is implicated in regulating the organization of actin cytoskeleton, a process critical for cell migration, mitosis, and tumor metastasis. In this report, we investigated whether Pyk2 played a role in the acquisition of an aggressive phenotype in prostate cell. Data reported here demonstrate that loss of Pyk2 kinase function results in induction of cell motility and migration in EPN cells, a line of non‐transformed epithelial cells derived from human normal prostate tissue. Changes in motility and migration of prostate cells were associated with changes in the expression of several proteins involved in cell adhesion and reorganization of actin cytoskeleton. Ablation of Pyk2 kinase activity caused a dramatic decrease of the expression of E‐cadherin and IRS1 and an increase of the expression of α5‐integrin. In addition, a massive reorganization of actin cytoskeleton was observed. Our data indicate that Pyk2 plays a central role in the mechanism that regulate cell–cell and cell–substrate interaction and lack of its kinase activity induces prostate cells to acquire a malignant, migrating phenotype. J. Cell. Physiol. 209: 74–80, 2006. © 2006 Wiley‐Liss, Inc.
Comparison of bovine and porcine β‐lactoglobulin: a mass spectrometric analysis
Authors: Invernizzi Gaetano , Šamalikova Maria , Brocca Stefania , Lotti Marina , Molinari Henriette , Grandori Rita
Published: June 2006

Nano‐electrospray‐ionization mass spectrometry (nano‐ESI‐MS) is applied to comparison of bovine and porcine β‐lactoglobulin (BLG and PLG). The conformational and oligomeric properties of the two proteins under different solvent and experimental conditions are analyzed. The pH‐dependence of dimerization is described for the pH range 2–11. The results indicate maximal dimer accumulation at pH 6 for BLG and pH 4 for PLG, as well as a lower stability of the PLG dimer at pH 4 compared to BLG at pH 6. Conformational stability appears to be higher for BLG at acidic pH, but higher for PLG at basic pH. The higher stability of BLG at low pH is revealed by means of either chemical or thermal denaturation. Equilibrium folding intermediates of both proteins are detected. Finally, conditions are found that promote dissociation of the BLG dimer at pH 6 into folded monomers. Copyright © 2006 John Wiley & Sons, Ltd.
Nonribosomal cyclic peptides: specific markers of fungal infections
Authors: Jegorov Alexandr , Hajduch Marian , Sulc Miroslav , Havlicek Vladimir
Published: June 2006

Some cyclic peptides and depsipeptides are synthesized in microorganisms by large multienzymes called nonribosomal peptide synthetases. The structures of peptide products originating in this way are complex and diverse and are microorganism‐specific. This work proposes the use of fungal cyclic peptides and depsipeptides as extremely specific markers of fungal infections. Since a reliable molecular tool for diagnosing fungal infections at an early stage is still missing, we present mass spectrometry as a new, modern, broadband (with respect to fungal strain) and specific tool for clinical mycologists. More than 40 different fungal species can be rapidly characterized according to specific families of cyclic peptides, and in some cases, a particular fungal strain can be identified on the basis of its cyclopeptide profile. This paper is also aimed at initiating discussion on the biological role of these secondary metabolites, especially of those synthesized by medically important strains. Proven cytotoxic, anti‐inflammatory or immunosuppressive activities of some cyclic peptides indicate that these molecules may contribute to the synergistic array of fungal virulence factors and support microbial invasion during fungal infection. In addition to an overview on recent mass spectrometric protocols for cyclic peptide sequencing, the structures of new peptides from Paecilomyces and Pseudallescheria are presented. Copyright © 2006 John Wiley & Sons, Ltd.
Non‐zwitterionic structures of aliphatic‐only peptides mediated the formation and dissociation of gas phase radical cations
Authors: Lam Corey N. W. , Ruan Eric D. L. , Ma C. Y. , Chu Ivan K.
Published: June 2006

We have investigated how the non‐zwitterionic and zwitterionic structures of aliphatic‐only tripeptides affect the formation and dissociation of peptide radical cations in the gas phase. The non‐zwitterionic forms of the aliphatic‐only peptides in their metal complexes play an important role in determining whether the electron transfer pathway predominates. We extended this study by synthesizing permanent non‐zwitterionic and zwitterionic forms of aliphatic‐only peptide radical cations and exploring their reactivities in the gas phase. Collision‐induced dissociation spectra demonstrated the feasibility of generating both non‐zwitterionic and zwitterionic forms. Radical cations in zwitterionic forms may indeed mediate the β and γ carbon–carbon bond cleavages of leucine and isoleucine side chains from the GlyGlyXle radical peptides; this feature allows leucine and isoleucine residues to be distinguished unambiguously. Copyright © 2006 John Wiley & Sons, Ltd.
Loss of arginase I results in increased proliferation of neural stem cells
Authors: Becker‐Catania Sara G. , Gregory Teresa L. , Yang Yawei , Gau Chia‐Ling , de Vellis Jean , Cederbaum Stephen D. , Iyer Ramaswamy K.
Published: June 2006

Loss of arginase I (AI) results in a metabolic disorder characterized by growth retardation, increased mental impairment and spasticity, and potentially fatal hyperammonemia. This syndrome plus a growing body of evidence supports a role for arginase and arginine metabolites in normal neuronal development and function. Here we report our initial observations of the effects of AI loss on proliferation and differentiation of neural stem cells (NSCs) isolated from the germinal zones of embryonic and newborn AI knockout (KO) mice compared with heterozygous (HET) and wild‐type (WT) control animals. By using both short and long‐term proliferation assays (3 and 10 days, respectively), we found a 1.5–2‐fold increase in the number of KO cells compared with WT. FACS analysis showed an increase in KO cells in the synthesis phase of the cell cycle vs. WT cells. After NSC differentiation, AI‐deficient cells expressed β‐tubulin, SMI81 (SNAP25), glial fibrillary acidic protein, and CNPase, which are markers consistent with neurons, astrocytes, and oligodendrocytes. Many KO cells exhibited a more mature morphology and expressed mature neuronal markers that were decreased or not present in HET or WT cells. Limited, comparative expression array and quantitative RT‐PCR analysis identified differences in the levels of several mRNAs encoding structural, signaling, and arginine metabolism proteins between KO and WT cells. The consequence of these changes may contribute to the differential phenotypes of KO vs. WT cells. It appears that AI may play an important and unanticipated role in growth and development of NSCs. © 2006 Wiley‐Liss, Inc.
Matrix effects in quantitative pesticide analysis using liquid chromatography–mass spectrometry
Authors: Niessen W.M.A. , Manini P. , Andreoli R.
Published: June 2006

Combined liquid chromatography–mass spectrometry using electrospray or atmospheric‐pressure chemical ionization has become an important tool in the quantitative analysis of pesticide residues in various matrices in relation to environmental analysis, food safety, and biological exposure monitoring. One of the major problems in the quantitative analysis using LC–MS is that compound and matrix‐dependent response suppression or enhancement may occur, the so‐called matrix effect. This article reviews issues related to matrix effects, focusing on quantitative pesticide analysis, but also paying attention to expertise with respect to matrix effects acquired in other application areas of LC–MS, especially quantitative bioanalysis in the course of drug development. © 2006 Wiley Periodicals, Inc.
Economic burden of Parkinson's disease in a developing country: A retrospective cost analysis in Shanghai, China
Authors: Wang Gang , Cheng Qi , Zheng Rui , Tan Yu‐Yan , Sun Xiao‐Kang , Zhou Hai‐Yan , Ye Xiao‐Lai , Wang Ying , Wang Zeng , Sun Bo‐Min , Chen Sheng‐Di
Published: June 2006

We investigated economic costs from patients with Parkinson's disease (PD) in Shanghai, China, which could be used as a baseline for future evaluations. Data were collected from 190 patients by interview during 1‐year period. Direct medical care costs averaged approximately Chinese yuan, renminbi (RMB) 4,305 (USD 519, or EUR 410) per year per patient, of which drugs (RMB 2,677) accounted for the major costly component. Nonmedical direct costs were much less than direct health care costs, averaging approximately RMB 3,301 (USD 398, or EUR 314). Costs due to loss of productivity averaged approximately RMB 73 (USD 8.8, or EUR 7.0) per patient per year. Taken together, the overall mean annual cost for PD in our series was approximately RMB 7,679 (USD 925, or EUR 731), and these costs accounted for around half of the mean annual income. Total cost was significantly associated with the disease severity and the frequency of outpatient visits. In addition, levodopa equivalent dose (LED) and the number of drugs being taken were also closely related with the drug cost. The results indicate that the economic burden of Chinese PD patients is heavy. © 2006 Movement Disorder Society
Non‐DYT1 early‐onset primary torsion dystonia: Comparison with DYT1 phenotype and review of the literature
Authors: Fasano Alfonso , Nardocci Nardo , Elia Antonio Emanuele , Zorzi Giovanna , Bentivoglio Anna Rita , Albanese Alberto
Published: June 2006

To investigate the clinical features of early‐onset primary torsion dystonia (EO‐PTD), 57 consecutive genetically characterized patients with onset before 21 years were studied. Sex, ethnic origin, family history of dystonia, age at onset, disease duration, site of dystonia onset and distribution at latest examination, dystonia progression, time to generalization, and motor disability were noted. The 14 patients (25%) with GAG deletion (904_906/907_909delGAG) in the DYT1 gene were compared with the remaining non‐DYT1 patients. Cranial involvement was present in 49% of non‐DYT1 cases, but only 14% of DYT1 cases; non‐DYT1 patients were younger at time of generalization. DYT1 cases had features similar to sporadic non‐DYT1 cases but differed markedly from familial non‐DYT1 cases, the latter having later age at onset, less common limb onset, more frequent cervical involvement, and slower progression than DYT1 PTD. These findings indicate that non‐DYT1 forms of EO‐PTD differ clinically from those of DYT1 forms. Cranial involvement before 21 years of age is the strongest predictor of non‐DYT1 status. Positive family history and cervical involvement are associated with less severe progression in non‐DYT1 forms. © 2006 Movement Disorder Society
Dopamine transporters, D2 receptors, and glucose metabolism in corticobasal degeneration
Authors: Klaffke Stefanie , Kuhn Andrea A. , Plotkin Michail , Amthauer Holger , Harnack Daniel , Felix Roland , Kupsch Andreas
Published: June 2006

Alterations in presynaptic and postsynaptic dopaminergic system and cerebral glucose metabolism in corticobasal degeneration (CBD) were assessed to evaluate the potential usefulness of different imaging methods for CBD. 123I‐FP‐CIT/123I‐β‐CIT SPECT and 123I‐IBZM SPECT as well as 18F‐FDG PET were performed in eight CBD patients. Decreased presynaptic dopamine transporter binding was found in all CBD patients while D2 receptor binding was reduced in only one patient. 18F‐FDG PET displayed a contralateral hypometabolism in cortical and subcortical areas in seven out of eight patients. Our results demonstrate that glucose metabolism and DAT are reduced, while D2 receptors may be frequently preserved in CBD. © 2006 Movement Disorder Society
Hyperhidrosis in Parkinson's disease
Authors: Schestatsky Pedro , Valls‐Solé Josep , Ehlers João Arthur , Rieder Carlos R.M. , Gomes Irênio
Published: June 2006

We studied the sudomotor skin response (SSR) in patients with Parkinson's disease with and without symptomatic hyperhidrosis. The study was carried out in 13 patients who complained of excessive sweating and in 37 patients who did not have excessive sweating. Patients were matched for age, sex, degree of impairment, duration of the disease, and number and severity of autonomic disturbances. Excessive sweating involved mainly the face, head, and trunk. The SSR was recorded from the palm of the hands to electrical stimulation of the median nerve at the wrist. We analyzed onset latency, peak to peak amplitude, and waveform. Patients with hyperhidrosis had more often absent responses (χ2 = 5.292; P = 0.021), their responses were of lower mean amplitude (analysis of variance [ANOVA]; F[2,101] = 11.678; P < 0.001), and they had a reduced number of responses with a predominantly negative component (χ2 = 8.493; P = 0.004) than patients who did not complain of sweating disturbances. Our results indicate that excessive sweating in Parkinson's disease concurs with decreased activation of sweat glands in the palms of the hands and suggests that axial hyperhidrosis could be a compensatory phenomenon for reduced sympathetic function in the extremities. © 2006 Movement Disorder Society
Retrospective distortion correction for 3D MR diffusion tensor microscopy using mutual information and fourier deformations
Authors: Mistry Nilesh N. , Hsu Edward W.
Published: June 2006

Magnetic resonance diffusion tensor imaging (DTI) can be complicated by distortions that contribute to errors in tissue characterization and loss of fine structures. This work presents a correction scheme based on retrospective registration via mutual information (MI), using Fourier transform (FT)‐based deformations to enhance the reliability of the entropy‐based image registration. The registration methodology is applied to correct distortions in 3D high‐resolution DTI datasets, incorporating a complete set of affine deformations. The results demonstrate that the proposed methodology can consistently and significantly reduce the number of misregistered pixels, leading to marked improvement in the visualization of internal brain white matter (WM) structure via DTI. Post‐registration analysis revealed that eddy‐current effects cannot fully account for the observed image distortions. Combined, these findings support the non‐model‐based, postprocessing approach for correcting distortions, and demonstrate the advantages of combining FT‐based deformations and MI registration to enhance the practical utility of DTI. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Integral transform solution of internal flow problems based on Navier–Stokes equations and primitive variables formulation
Authors: de Lima G. G. C. , Santos C. A. C. , Haag A. , Cotta R. M.
Published: June 2006

The generalized integral transform technique (GITT) is employed in the solution of incompressible laminar channel flows as formulated by the steady‐state Navier–Stokes and continuity equations under the primitive variables mathematical representation. A hybrid numerical–analytical solution is developed based on eigenfunction expansions in one space co‐ordinate and error‐controlled numerical solution of the resulting system of coupled ordinary differential equations in the remaining space direction. The approach is illustrated for developing flow between parallel‐plates with uniform and irrotational inlet flow condition. The conventional Poisson‐type equation for the pressure field with appropriate boundary conditions is also transformed and simultaneously solved with the momentum equation along the longitudinal direction, by considering eigenvalue problems for each of the two potentials, defined in the transversal direction. The transversal velocity component is then explicitly determined from the continuity equation. Numerical results of the longitudinal velocity component and friction factor fields are reported to illustrate the convergence behaviour and user prescribed error control inherent to the proposed hybrid approach. Critical comparisons with previous contributions on the same method that made use of the streamfunction‐only formulation are also provided. Copyright © 2006 John Wiley & Sons, Ltd.
Generalized coupled thermoelasticity of functionally graded cylindrical shells
Authors: Bahtui A. , Eslami M. R.
Published: June 2006

In this paper, the response of a circular cylindrical thin shell made of the functionally graded material based on the generalized theory of thermoelasticity is obtained. The governing equations of the generalized theory of thermoelasticity and the energy equations are simultaneously solved for a functionally graded axisymmetric cylindrical shell subjected to thermal shock load. Thermoelasticity with second sound effect in cylindrical shells based on the Lord–Shulman model is compared with the Green–Lindsay model. A second‐order shear deformation shell theory, that accounts for the transverse shear strains and rotations, is considered. Including the thermo‐mechanical coupling and rotary inertia, a Galerkin finite element formulation in space domain and the Laplace transform in time domain is used to formulate the problem. The inverse Laplace transform is obtained using a numerical algorithm. The shell is graded through the thickness assuming a volume fraction of metal and ceramic, using a power law distribution. The effects of temperature field for linear and non‐linear distributions across the shell thickness are examined. The results are validated with the known data in the literature. Copyright © 2006 John Wiley & Sons, Ltd.
Enhanced one‐point quadrature shell element for nonlinear applications
Authors: Cardoso Rui P. R. , Yoon Jeong Whan , Valente Robertt A. F.
Published: June 2006

This work is an extension to nonlinear applications of a previously published work (Int. J. Numer. Meth. Engng 2006; 66:214–249) about membrane and transverse shear improvement for one‐point quadrature shell elements. A new formulation based on the enhanced assumed strain method and reduced integration techniques, called iCYSE‐E6 (improved Cardoso and Yoon shell element with 6 enhanced parameters) was suggested by Cardoso et al. to improve membrane and transverse shear performances under the framework of linear applications. It was proven that the proposed linear formulation gives accurate responses, even with extremely coarse meshes. The proposed extension of this work is then performed in such a way that the resulting new finite element can be applied in general simulations with nonlinearities in geometry, material and contact.

The interaction among hourglass and enhanced assumed strain stiffness matrices and internal force vectors is taken into account in the present formulation. Special emphasis is given for the construction of nonlinear hourglass terms such that excessive hourglass energy in elastoplastic applications can be controlled efficiently. The finite element matrices are constructed in resultant form, allowing a much simpler and effective formulation for the hourglass terms, and also for the coupling between the constant and the enhanced strain–displacement matrices. It is shown that the present formulation is accurate in demanding problems, even for the cases of relatively large coarse mesh structures. The paper presents several nonlinear examples to assess the element's performance. Copyright © 2006 John Wiley & Sons, Ltd.