bluuebunny/crossref_metadata_2025 huggingface dataset:
Tetrathiafulvalene‐Labelled Nucleosides and Nucleoside Triphosphates: Synthesis, Electrochemistry and the Scope of Their Polymerase Incorporation into DNA
Authors: Riedl Jan , Horáková Petra , Šebest Peter , Pohl Radek , Havran Luděk , Fojta Miroslav , Hocek Michal
Published: June 2009

The title 5‐substituted pyrimidines (U and C) and 7‐substituted 7‐deazapurines (7‐deazaA and 7‐deazaG) bearing tetrathiafulvelene (TTF) attached through an acetylene linker have been prepared by Sonogashira cross‐coupling of the corresponding 5‐ or 7‐iodo derivatives of nucleosides with 2‐ethynyltetrathiafulvalene. Their subsequent triphosphorylation gave the corresponding nucleoside triphosphates (dNTPs). Square‐wave voltammetry of the TTF‐labelled nucleosides and nucleotides showed two peaks, one at 0.2–0.3 V and the other at around 0.65 V (vs. Ag|AgCl|3 M KCl), which correspond to two reversible one‐electron redox processes in the TTF moiety. Polymerase incorporation of the TTF‐labelled dNTPs into DNA has also been studied. Multiple incorporations were rather problematic and only by using dCTTFTP was efficient primer extension observed with Vent (exo‐)polymerase. Single nucleotide extension was successful with labelled A (dA*TTFTP) and C (dCTTFTP) nucleotides. Inhibition of the polymerase was observed at higher concentrations of dNTTFTPs.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Catalytic Oxidation of Dopamine at a Nickel Hexacyanoferrate Surface Modified Graphite Wax Composite Electrode Coated with Nafion
Authors: Prabakar S. J. Richard , Narayanan S. Sriman
Published: June 2009

A chemically modified electrode was successfully fabricated by means of depositing a thin layer of nickel hexacyanoferrate (NiHCF) on an amine adsorbed graphite paraffin wax composite electrode using a new approach. The electrode was further coated with Nafion. The electrochemical characteristics of the modified electrode were studied using cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The modified electrode catalyzed dopamine (DA) oxidation in the concentration range of 1.5×10−6 to 1.2×10−3 M without the interference from ascorbic acid (AA). A detection limit of 4.9×10−7 M was obtained for DA in the presence of AA with a correlation coefficient of 0.9972 based on S/N=3. Flow injection analysis was used for the determination of dopamine with excellent reproducible results. The analytical utility of the sensor was evaluated for detection of DA in urine.
Glucosinolate Amperometric Bienzyme Biosensor Based on Carbon Nanotubes‐Gold Nanoparticles Composite Electrodes
Authors: Serafín V. , Agüí L. , Yáñez‐Sedeño P. , Pingarrón José M.
Published: June 2009

A novel electrochemical biosensor design for glucosinolate determination involving bulk‐incorporation of the enzymes glucose oxidase and myrosinase into a colloidal gold ‐ multiwalled carbon nanotubes composite electrode using Teflon as binder is reported. Myrosinase catalyzes the hydrolysis of glucosinolate forming glucose, which is enzymatically oxidized. The generated hydrogen peroxide was electrochemically detected without mediator at the nanostructured composite electrode at E=+0.5 V vs. Ag/AgCl. Under the optimized conditions, the bienzyme MYR/GOx‐Aucoll‐MWCNT‐Teflon exhibited improved analytical characteristics for the glucosinolate sinigrin with respect to a biosensor constructed without gold nanoparticles, i.e. a MYR/GOx‐MWCNT‐Teflon electrode, as well as with respect to other glucosinolate biosensor designs reported in the literature. The biosensor exhibits good repeatability of the amperometric measurements and good interassay reproducibility. Furthermore, the biosensor exhibited a high selectivity with respect to various potential interferents. The usefulness of the biosensor was evaluated by the determination of glucosinolate in Brussel sprout seeds.
Voltammetric Studies of the Interactions Between Ferrocene‐Labeled Glutathione and Proteins in Solution or Immobilized onto Surface
Authors: Peng Yong , Liu You‐Nian , Zhou Feimeng
Published: June 2009

Glutathione (GSH) tagged with a ferrocene (Fc) label at its C‐terminal was synthesized via coupling ferrocenyl amine to glutathione using o‐(benzotriazol‐1‐yl)‐N,N,N′,N′‐tetramethyluronium (HBTU)/1‐hydroxybenzotrizole (HOBt). The presence of Fc yielded well defined voltammetric signals, rendering the Fc‐tagged GSH (GSH‐Fc) suitable for electrochemical studies of GSH binding to other biological species. The interaction of GSH‐Fc with bovine serum albumin (BSA) was investigated, and a binding ratio of 1.41±0.06 (GSH‐Fc/BSA) and an affinity constant Ka of 6.53±2.01×106 M−1 were determined. These results compare well with those measured by fluorescence using untagged GSH, suggesting that the attachment of Fc to GSH does not significantly perturb the GSH structure and binding behavior. By contrasting the binding behavior to several compounds that are known to conjugate to different domains of BSA, the voltammetric study confirmed that GSH‐Fc binds at subdomain IIA of BSA with high affinity. The versatility of GSH‐Fc for studying GSH binding to surface‐confined proteins was also demonstrated with the GSH binding to electroinactive Zn‐metallothionein (Zn7‐MT) through hydrogen binding at the region between the Zn7‐MT α and β domains.
Evaluation of simplified methods of analysis for structures with triple friction pendulum isolators
Authors: Fadi Fabio , Constantinou Michael C.
Published: June 2009

Triple friction pendulum isolators, that exhibit behavior with amplitude‐dependent strength and instantaneous stiffness, represent a new development in seismic isolation. The application of simplified methods of analysis for this type of seismically isolated structures requires development of tools of simplified analysis and demonstration of their accuracy. This paper describes these tools and presents validation studies based on a large number of nonlinear response history analysis results. It is shown that simplified methods of analysis systematically provide good and often conservative estimates of isolator displacement demands and good estimates of isolator peak velocities. Copyright © 2009 John Wiley & Sons, Ltd.
A multiservice WLAN using a radio resource scheduler
Authors: Inaty Elie
Published: June 2009

In this paper we consider the problem of resource allocation in a multiservice wireless local area network (WLAN) using overlapped code division multiple access (OV‐CDMA) andviaa centralised radio resource scheduler (RRS). A joint overlap control and power management (OCPM) algorithm is providedviathe solution of a constrained convex quadratic optimisation problem. A closed form solution of the optimisation problem is presented. It is shown that the proposed OCPM resource allocation scheme is simple to implement in WLANs. Results are presented showing a total agreement between the analytical and the numerical results. In addition, it is shown that the solution of this problem maximises the aggregate throughput subject to peak transmission power constraints. Copyright © 2009 John Wiley & Sons, Ltd.
Environmental evaluation practices and the issue of scale
Authors: Bruyninckx Hans
Published: June 2009

Social scientists, natural scientists, and evaluators have not properly defined the concept of scale for environmental problems. Environmental scale generally differs from social scale, which confounds the challenge of evaluating policies and governance arrangements in addressing environmental issues. Instead, social scales are generally based on traditional jurisdictional boundaries, and this complicates effective decision making. Conversely, evaluators must be able to assess innovative governance arrangements as well as the outcomes of environmental problems because the two are interconnected. This is particularly true in looking at cross‐scale, social‐ecological interactions. This has profound implications for policy evaluation; evaluators have to develop frameworks for connecting across various scales and levels in overcoming mismatches. Natural scientists probably need to be humbler in their ambitions, and evaluators will have to engage in interdisciplinary teams that blend the expertise of the social sciences with that from the natural sciences to assess outcomes to social and environmental scales. © Wiley Periodicals, Inc.
Data credibility: What are the “right” data for evaluating management effectiveness of protected areas?
Authors: Hockings Marc , Stolton Sue , Dudley Nigel , James Robyn
Published: June 2009

Evaluation of protected area management has received increased attention over the past decade, with many thousands of sites assessed. Many of the management effectiveness evaluation systems rely predominantly on expert knowledge and qualitative assessment, especially where the emphasis is on rapid assessment. Others use quantitative data or a mix of data types. We propose that decisions about the appropriateness of qualitative and quantitative data and methods for evaluating management effectiveness of protected areas can be informed by considering issues of (1) the subject matter of evaluation; (2) available resources and data; (3) scale, scope, and time frame of the evaluation; and (4) risks associated with management of the site. ©Wiley Periodicals, Inc.
Data credibility: A perspective from systematic reviews in environmental management
Authors: Pullin Andrew S. , Knight Teri M.
Published: June 2009

To use environmental program evaluation to increase effectiveness, predictive power, and resource allocation efficiency, evaluators need good data. Data require sufficient credibility in terms of fitness for purpose and quality to develop the necessary evidence base. The authors examine elements of data credibility using experience from critical appraisal of studies on environmental interventions employing systematic review methodology. They argue that critical appraisal of methodological quality is a key skill to improve both retrospective evaluation and prospective planning of monitoring of environmental programs. Greater transparency and data sharing among evaluators could facilitate rapid development in approaches to environmental evaluation that improve data credibility. © Wiley Periodicals, Inc.
Design alternatives for evaluating the impact of conservation projects
Authors: Margoluis Richard , Stem Caroline , Salafsky Nick , Brown Marcia
Published: June 2009

Historically, examples of project evaluation in conservation were rare. In recent years, however, conservation professionals have begun to recognize the importance of evaluation both for accountability and for improving project interventions. Even with this growing interest in evaluation, the conservation community has paid little attention to evaluation design. Recent literature includes some discussion of design, but it has focused primarily on experimental and quasi‐experimental design and the use of counterfactuals. Real‐life conservation projects, however, operate in complex and dynamic contexts and under conditions of limited resources, which limit the feasibility of counterfactual or experimental designs. There is, in fact, a range of design options to evaluate conservation interventions. The conservation community must educate itself about these options, and how different designs produce different results. This chapter discusses evaluation design alternatives in light of the unique challenges that influence evaluation design selection in conservation. © Wiley Periodicals, Inc.
Stability of flow past a cylinder: Energy budget of eigenmodes
Authors: Mittal Sanjay
Published: June 2009

Global linear stability analysis of the flow past a circular cylinder at the onset of primary wake instability is carried out. The real and imaginary parts of the most unstable eigenmode, responsible for vortex shedding, are very similar but associated with a spatial shift in the vortex structures. This shift results in the convection of vortices that are observed in the unsteady flow, which is actually a consequence of global absolute instability. The kinetic energy density, associated with the most unstable eigenmode, is studied. At the onset of the instability the energy density of the disturbance field is found to be stronger in the far wake compared with the near wake. With increase in Re the region where the disturbance is strong moves upstream closer to the cylinder. However, the maximum value of the kinetic energy density of the disturbance lies outside the recirculation zone even for Re upto 100. A linearized mechanical energy equation for the time evolution of the kinetic energy density of the disturbance is utilized to examine the energy budget of the most unstable eigenmode at various Re. It is found that the most significant contribution to the growth rate of the disturbance arises from the transfer of the energy due to the strain rate of the base flow to the perturbation. The stabilizing effect of the viscous dissipation increases with increase in Re, but saturates for Re beyond ∼70. Copyright © 2009 John Wiley & Sons, Ltd.
Interpolation among reduced‐order matrices to obtain parameterized models for design, optimization and probabilistic analysis
Authors: Degroote Joris , Vierendeels Jan , Willcox Karen
Published: June 2009

Model reduction has significant potential in design, optimization and probabilistic analysis applications, but including the parameter dependence in the reduced‐order model (ROM) remains challenging. In this work, interpolation among reduced‐order matrices is proposed as a means to obtain parameterized ROMs. These ROMs are fast to evaluate and solve, and can be constructed without reference to the original full‐order model. Spline interpolation of the reduced‐order system matrices in the original space and in the space tangent to the Riemannian manifold is compared with Kriging interpolation of the predicted outputs. A heuristic criterion to select the most appropriate interpolation space is proposed. The interpolation approach is applied to a steady‐state thermal design problem and probabilistic analysis via Monte Carlo simulation of an unsteady contaminant transport problem. Copyright © 2009 John Wiley & Sons, Ltd.
Relation between brain lesion location and clinical outcome in patients with severe traumatic brain injury: A diffusion tensor imaging study using voxel‐based approaches
Authors: Perlbarg Vincent , Puybasset Louis , Tollard Eléonore , Lehéricy Stéphane , Benali Habib , Galanaud Damien
Published: June 2009

The early prediction of consciousness recovery from traumatic brain injury (TBI) is crucial to make decisions about the appropriate use of prolonged intensive care. Diffusion tensor imaging (DTI) has been proposed as a biomarker of white matter injury that could be used in a classification purpose. Instead of region‐of‐interest‐based approach, we applied voxel‐based approaches (voxel‐based DTI and tract‐based spatial statistics) on 30 patients with TBI to identify, without any prior, the brain regions that were specifically damaged in unfavorable 1‐year outcome group compared to the favorable one. DTI were acquired at mean 23 days (5–53 days) and two DTI‐derived indices, fractional anisotropy (FA) and apparent diffusion coefficient (ADC), were tested. Our results showed that (1) ADC is not a relevant biomarker for early 1‐year outcome prognosis; (2) FA measured in inferior longitudinal fasciculus, in cerebral peduncle, in posterior limb of the internal capsule, and in posterior corpus callosum is specifically decreased in unfavorable outcome group compare to the favorable one; (3) a linear discriminant analysis using the FA measured in these four regions showed good classification performance (sensitivity = 86% and specificity = 86%). These findings confirm the relevance of the use of DTI as biomarkers for consciousness recovery after TBI and support the possible use of these biomarkers for early classification of patients. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Entorhinal cortex structure and functional MRI response during an associative verbal memory task
Authors: Braskie Meredith N. , Small Gary W. , Bookheimer Susan Y.
Published: June 2009

Entorhinal cortex (ERC) volume in adults with mild cognitive impairment has been shown to predict prodromal Alzheimer's disease (AD). Likewise, neuronal loss in ERC has been associated with AD, but not with normal aging. Because ERC is part of a major pathway modulating input to the hippocampus, structural changes there may result in changes to cognitive performance and functional brain activity during memory tasks. In 32 cognitively intact older adults, we examined the relationship between left ERC thickness and functional magnetic resonance imaging (fMRI) activity during an associative verbal memory task. This task has been shown previously to activate regions that are sensitive to aging and AD risk. ERC was manually defined on native space, high resolution, oblique coronal MRI scans. Subjects having thicker left ERC showed greater activation in anterior cingulate and medial frontal regions during memory retrieval, but not encoding. This result was independent of hippocampal volume. Anterior cingulate cortex is directly connected to ERC, and is, along with medial frontal cortex, implicated in error detection, which is impaired in AD. Our results suggest that in healthy older adults, processes that engage frontal regions during memory retrieval are related to ERC structure. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Noninvasive dynamic imaging of seizures in epileptic patients
Authors: Tyvaert Louise , LeVan Pierre , Dubeau Francois , Gotman Jean
Published: June 2009

Epileptic seizures are due to abnormal synchronized neuronal discharges. Techniques measuring electrical changes are commonly used to analyze seizures. Neuronal activity can be also defined by concomitant hemodynamic and metabolic changes. Simultaneous electroencephalogram (EEG)‐functional MRI (fMRI) measures noninvasively with a high‐spatial resolution BOLD changes during seizures in the whole brain. Until now, only a static image representing the whole seizure was provided. We report in 10 focal epilepsy patients a new approach to dynamic imaging of seizures including the BOLD time course of seizures and the identification of brain structures involved in seizure onset and discharge propagation. The first activation was observed in agreement with the expected location of the focus based on clinical and EEG data (three intracranial recordings), thus providing validity to this approach. The BOLD signal preceded ictal EEG changes in two cases. EEG‐fMRI may detect changes in smaller and deeper structures than scalp EEG, which can only record activity form superficial cortical areas. This method allowed us to demonstrate that seizure onset zone was limited to one structure, thus supporting the concept of epileptic focus, but that a complex neuronal network was involved during propagation. Deactivations were also found during seizures, usually appearing after the first activation in areas close or distant to the activated regions. Deactivations may correspond to actively inhibited regions or to functional disconnection from normally active regions. This new noninvasive approach should open the study of seizure generation and propagation mechanisms in the whole brain to groups of patients with focal epilepsies. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
N → C3 migration of dichlorophosphino group in the phosphorylation of N‐unsubstituted indole with phosphorus trichloride
Authors: Chaikovskaya Aleksandra A. , Dmytriv Yurii V. , Shevchuk Nadiya V. , Smaliy Radomyr V. , Pinchuk Aleksander M. , Tolmachev Andrey A.
Published: June 2009

A N → C3 migration of the dichlorophosphino group has been revealed in the phosphorylation of unsubstituted indole with phosphorus trichloride. Several 3‐phosphorylated NH‐indole derivatives have thus been obtained and N‐acylation of one of the products has been performed. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:235–239, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20540
Scavenger Receptor Class B Type I Mediates Biliary Cholesterol Secretion Independent of ATP-Binding Cassette Transporter g5/g8 in Mice†
Authors: Wiersma Harmen , Gatti Alberto , Nijstad Niels , Oude Elferink Ronald P. J. , Kuipers Folkert , Tietge Uwe J. F.
Published: June 2009

Scavenger receptor class B type I (SR-BI) mediates selective uptake of cholesterol from high-density lipoprotein (HDL) particles by the liver and influences biliary cholesterol secretion. However, it is not clear, if this effect is direct or indirect. The aim of this study was to determine the impact of SR-BI on biliary cholesterol secretion, especially in a functional context with ATP-binding cassette transporter g5 (Abcg5)/Abcg8 and Abcb4. SR-BI was overexpressed by means of adenovirus (AdSR-BI) in livers of wild-type, liver X receptor–null (Lxr−/−), Abcg5−/−, and Abcb4−/− mice. Consistent with previous reports, AdSR-BI decreased plasma HDL cholesterol levels in all models (

P

< 0.001). Hepatic cholesterol content increased (at least

P

< 0.05), whereas expression of sterol regulatory element binding protein 2 target genes was decreased (at least

P

< 0.05,) and established Lxr target genes were unaltered. Biliary cholesterol secretion was increased by AdSR-BI in wild-type as well as in Lxr−/− and Abcg5−/− mice, and considerably less in Abcb4−/− mice (each

P

< 0.001), independent of bile acid and phospholipid secretion. Immunogold electron microscopy and western blot showed a substantial increase of SR-BI protein localized to basolateral and canalicular membranes in response to SR-BI overexpression. Subcellular fractionation revealed a significantly higher cholesterol content of canalicular membranes (

P

< 0.001) upon SR-BI overexpression. Inhibition of microtubule function did not affect SR-BI–mediated biliary cholesterol secretion, indicating that transcytosis pathways are not involved.

Conclusion:

Our data indicate that SR-BI mediates biliary cholesterol secretion independent of Abcg5, yet largely depends on Abcb4-mediated phospholipid secretion and mixed micelles as acceptors in bile. SR-BI–mediated biliary cholesterol secretion has a high capacity, can compensate for the absence of Abcg5, and does not require transcytosis pathways. (Hepatology 2009.)
Restriction of cisplatin induction of acute apoptosis to a subpopulation of cells in a three‐dimensional carcinoma culture model
Authors: Fayad Walid , Brnjic Slavica , Berglind Daniel , Blixt Susanna , Shoshan Maria C. , Berndtsson Maria , Olofsson Maria Hägg , Linder Stig
Published: June 2009

Cisplatin is a clinically important chemotherapeutical agent used to treat epithelial malignancies. High concentrations (20–100 μM) of cisplatin have been used in numerous studies to induce apoptosis of carcinoma cells grown in monolayer culture over 24–48 hr. These conditions may not be relevant to 3‐D tumor tissue in vivo and the importance of apoptosis for tumor response is controversial. We here studied the effects of cisplatin on a 3‐D colon carcinoma in vitro model (multicellular spheroids). Cisplatin at a dose of 40 μM induced active caspase‐3 preferentially in the peripheral 30 μm cell layer of spheroids, mainly during late stages (72–96 hr). The p53 response to cisplatin was also largely confined to peripheral cell layers. Despite the use of a high cisplatin concentration, a significant fraction of the cells in the spheroids survived treatment. A high proportion of surviving cells stained positive for β‐galactosidase, a marker of premature senescence. Cells growth‐arrested by cisplatin treatment showed a higher spontaneous cell death rate than untreated proliferating cells. We propose that acute apoptosis is of minor significance for the overall response of carcinoma cells to cisplatin treatment. © 2009 UICC
Fisetin, a natural flavonoid, targets chemoresistant human pancreatic cancer AsPC‐1 cells through DR3‐mediated inhibition of NF‐κB
Authors: Murtaza Imtiyaz , Adhami Vaqar Mustafa , Hafeez Bilal Bin , Saleem Mohammad , Mukhtar Hasan
Published: June 2009

Death receptors of the tumor necrosis factor (TNF) receptor super family have been implicated in constitutive activation of nuclear factor‐kappa B (NF‐κB) in pancreatic cancer (PaC) cells. In this study, we demonstrate that fisetin, a natural flavonoid, induces apoptosis and inhibits invasion of chemoresistant PaC AsPC‐1 cells through suppression of DR3‐mediated NF‐κB activation. Fisetin treatment resulted in dose‐dependent inhibition of PaC cell growth and cell proliferation with concomitant induction of apoptosis. A cDNA array analysis revealed that fisetin modulates expression of more than 20 genes at transcription level with maximum decrease observed in DR3 expression and a parallel increase observed in the expression levels of IκBα, an NF‐κB inhibitor. Down‐regulation of DR3 in PaC cells was found to down regulate activated pNF‐κB/p65, pIkBα/β kinases (pIKK's), MMP9 and XIAP that mostly impart chemoresistance in PaC. Immunoblotting and EMSA analysis showed a marked decrease in pNF‐κB and NF‐κB DNA binding activity, respectively, with modest decrease in NF‐κB promoter activity and significant decrease in MMP9 promoter activity with fisetin treatment. Importantly, consistent with these findings, we further found that transient down‐regulation of DR3 by RNA interference significantly augmented fisetin induced changes in cell proliferation, cell invasion and apoptosis paralleled with decrease in pNF‐κB, pIKKα/β, MMP9, XIAP and NF‐κB DNA binding activity. Blocking of DR3 receptor with an extra cellular domain blocking antibody demonstrated similar effects. These data provide evidence that fisetin could provide a biological rationale for treatment of pancreatic cancer or as an adjuvant with conventional therapeutic regimens. © 2009 UICC
The shared tumor associated antigen cyclin‐A2 is recognized by high‐avidity T‐cells
Authors: Kondo Eisei , Maecker Britta , Draube Andreas , Klein‐Gonzalez Nela , Shimabukuro‐Vornhagen Alexander , Schultze Joachim L. , von Bergwelt‐Baildon Michael S.
Published: June 2009

Cyclin‐A2, a key cell cycle regulator, has been shown to be overexpressed in various types of malignancies with little expression in normal tissue. Such tumor‐associated genes potentially are useful targets for cancer immunotherapy. However, high‐avidity cyclin‐specific T cells are considered to be thymically deleted. We identified at least one nonameric HLA‐A*0201 binding cyclin‐A2 epitope by a reverse immunology approach. Using a highly efficient T‐cell expansion system that is based on CD40‐activated B (CD40‐B) cells as sole antigen‐presenting cells we successfully generated cyclin‐A2 specific CTL from HLA‐A*0201+ donors. Interestingly, high‐avidity cyclin‐A2 specific CTL lines, which recognized peptide‐pulsed and antigen expressing target cells, were indeed generated by stimulation with CD40‐B cells when pulsed with low concentrations of peptide, whereas CD40‐B cells pulsed at saturating concentrations could only induce low‐avidity CTL, which recognized peptide‐pulsed target cells only. One high‐avidity CTL line was subcloned and CTL clones, whose peptide concentration required for half‐maximal lysis were less than 1 nM, could lyse cyclin‐A2 expressing tumor cells. Taken together, cyclin A2 is an attractive candidate for immune intervention in a significant number of cancer patients and high‐avidity T cells can be readily generated using CD40‐B cells as antigen‐presenting cells. © 2009 UICC
Temporal trends over 3 decades and intrafamilial clustering of HPV types in Swedish patients with cervical cancer in situ
Authors: Ivansson Emma L. , Gustavsson Inger M. , Wilander Erik , Magnusson Patrik K.E. , Gyllensten Ulf B.
Published: June 2009

Information on HPV type distribution in cervical cancer in situ in different populations is needed for evaluation of prophylactic vaccination programs targeting HPV 16 and 18. In our study, the HPV type prevalence in 1,079 Swedish women from multicase families diagnosed with cervical cancer in situ 1965–1993 was investigated using real‐time PCR and archival tissue material. HPV type information was obtained for 974 samples. Among these, HPV 16 (61%) was the dominant type followed by HPV 33/52/58 (24%), HPV 31 (13%) and HPV 18/45 (12%). The detected prevalence of HPV 16 among cancer in situ decreased by 13% over the study period while the group of low frequency high‐risk types increased. Related women were not prone to infection by the same type. These data suggest that the prevalence of individual HPV types has changed over time in Swedish patients with cervical cancer in situ. Large‐scale studies of pathology biobank materials will enable further insight into the temporal changes of individual HPV types, as baseline information to properly evaluate the effect of vaccine programs. The findings also indicate that genetic susceptibility to cervical cancer operates through general and not type specific susceptibility to HPV infection. © 2009 UICC
Strategies for digital mammography interpretation in a clinical patient population
Authors: van den Biggelaar Frank J.H.M. , Kessels Alphons G.H. , van Engelshoven Jos M.A. , Flobbe Karin
Published: June 2009

Mammography is the basic imaging modality for early detection of breast cancer. The aim of this prospective study was to evaluate the impact of different mammogram reading strategies on the diagnostic yield in a consecutive patient population referred for digital mammography to a hospital. First, the effect of using computer‐aided detection (CAD) software on the performance of mammogram readers was studied. Furthermore, the impact of employing technologists as either prereaders or double readers was assessed, as compared to the conventional strategy of single reading by a radiologist. Digital mammograms of 1,048 consecutive patients were evaluated by a radiologist and 3 technologists with and without the use of CAD software. ROC analysis was used to study the effects of the different strategies. In the conventional strategy, an overall area under the curve (AUC) of 0.92 was found, corresponding to a sensitivity of 84% and specificity of 94%. When applying CAD software, the AUCs were similar before and after CAD for all readers (mean of 0.95). Employing technologists in prereading and double reading of mammograms resulted in a mean AUC of 0.91 and 0.96, respectively. In the prereading strategy, the corresponding sensitivity and specificity were 81 and 96%; in the double reading strategy they were 96 and 79%, respectively. Concluding, in this clinical population, systematic application of CAD software by either radiologist or technologists failed to improve the diagnostic yield. Furthermore, employing technologists as double readers of mammograms was the most effective strategy in improving breast cancer detection in daily clinical practice. © 2009 UICC
Morphological studies on machined implants of commercially pure titanium and titanium alloy (Ti6Al4V) in the rabbit
Authors: Palmquist Anders , Lindberg Fredrik , Emanuelsson Lena , Brånemark Rickard , Engqvist Håkan , Thomsen Peter
Published: June 2009

The aim of this study was to evaluate the bone response to commercially pure titanium grade I and titanium alloy grade V (90% Ti, 6% Al, and 4% V, depicted Ti6Al4V) after 8 weeks in rabbit tibia. Interference microscopy and scanning electron microscopy were used for surface analyses. Transmission electron microscopy (TEM) was used for evaluation of surface crystallinity and chemistry after preparation of ultrathin sections using focused ion beam (FIB) microscopy. Three different embedding resins commonly used for histological preparation were evaluated with respect to adaptation to a turned implant surface. Epoxy Agar 100 resin and acrylic Technovit 7200 resin showed low separation while acrylic LR White resin showed large separation at the interface. The retrieved specimens were embedded in acrylic Technovit 7200 resin after fixation and dehydration. The histological evaluation revealed osseointegration for both c.p. titanium grade I and Ti6Al4V alloy, but no quantitative differences in bone contact and bone area were detected. Because a separation of implant and tissue occurred in the interface between implant and bone embedded in acrylic Technovit 7200 resin, additional factors related to implant surface properties and technical procedures are likely to influence the possibilities to prepare ultrathin sections by FIB. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Favorable effects of the detergent and enzyme extraction method for preparing decellularized bovine pericardium scaffold for tissue engineered heart valves
Authors: Yang Min , Chen Chang‐Zhi , Wang Xue‐Ning , Zhu Ya‐Bin , Gu Y. John
Published: June 2009

Bovine pericardium has been extensively applied as the biomaterial for artificial heart valves and may potentially be used as a scaffold for tissue‐engineered heart valves after decellularization. Although various methods of decellularization are currently available, it is unknown which method is the most ideal one for the decellularization for bovine pericardium. We compared three decellularization methods, namely, the detergent and enzyme extraction (DEE), the trypsin (TS), and the Triton X‐100 and sodium‐deoxycholate (TSD) method, to examine their efficacy on cell removal and their preservation of the mechanical function and the tissue matrix structure. Results indicated that decellularization was achieved by all the three methods as confirmed by hematoxylin‐eosin staining, scanning electron microscopy, as well as quantitative DNA measurement. However, TS and TSD methods resulted in severe structural destruction of the bovine pericardium as shown by von Gieson staining and Gomori staining. Furthermore, both TS and TSD methods changed the mechanical property of the bovine pericardium, as evidenced by a lower elastic modulus, maximal‐stress, maximal‐disfiguration, maximal‐load, and maximal‐strain. In conclusion, the DEE method achieved both a complete decellularization and preservation of the mechanical function and tissue structure of the bovine pericardium. Thus, this method is superior to either the TS or the TSD method for preparing decellularized bovine pericardium scaffold for constructing tissue‐engineered heart valves. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
The use of collagen cross‐linking agents to enhance dentin bond strength
Authors: Al‐Ammar Aiman , Drummond James L. , Bedran‐Russo Ana Karina
Published: June 2009

Type I collagen is a major component of the hybrid layer, and improvement of its mechanical properties may be advantageous during bonding procedures.

Objective:

To investigate the effect of three different cross‐linking agents (Glutaraldehyde [GD], Grape seed extract [GSE], and Genipin [GE]) on the tensile bond strength (TBS) of resin‐dentin bonds.

Materials and Methods:

Sixty‐four sound human molars were collected and their occlusal surfaces were ground flat to expose dentin. Dentin surfaces were etched using a phosphoric acid and then teeth were randomly divided according to the dentin treatment: Control group (no treatment), 5% GD, 6.5% GSE, or 0.5% GE. Teeth were restored either with One Step Plus or Adper Single Bond Plus adhesive systems and resin composite. After 24 h, teeth were sectioned to produce a cross‐sectional surface area of 1.0 mm2 and tested for tensile bond strength. Data were statistically analyzed using ANOVA and Fisher's PLSD tests (p < 0.05). There was a statistically significant interaction between factors (treatment and adhesive p < 0.001). Treatment affected TBS (p < 0.0001), while no differences were observed between the adhesive systems (p = 0.6961).

Conclusion:

Chemical modification to the dentin matrix promoted by GD and GSE, but not GE, resulted in increased bond strength. The application of selective collagen cross‐linkers during adhesive restorative procedures may be a new approach to improve dentin bond strength properties. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Development of β‐tricalcium phosphate/sol‐gel derived bioactive glass composites: Physical, mechanical, and in vitro biological evaluations
Authors: Hesaraki Saeed , Safari Mojgan , Shokrgozar Mohammad Ali
Published: June 2009

In this study, composites of β‐tricalcium phosphate (β‐TCP) and sol gel derived bioactive glass (10, 25, and 40 wt %) based on the SiO2‐CaO‐MgO‐P2O5 system were prepared and sintered at 1000–1200°C. The mechanical properties were investigated by measuring bending strength, Vickers hardness and fracture toughness. Structural properties were evaluated by XRD and SEM analysis, and the biological properties were studied by soaking the samples in simulated body fluid (SBF) and in contact with osteoblastic cell for viability assay. When the samples were sintered at 1200°C, the mechanical strength increased, up to 34%, by increasing the amount of bioactive glass phase. In contrast, it decreased when the samples were sintered at 1000 and 1100°C. The results showed that the strength could be improved up to 56% when more firing period was used. Incorporation of the bioactive glass phase into β‐TCP increased the microhardness but did not significantly change the fracture toughness. Phase analysis revealed that β‐TCP or magnesium‐substituted β‐TCP was the main crystalline phase of the composites beside some calcium silicate crystallized in the bioactive glass phase. Plenty precipitation of calcium phosphate layer onto the surfaces of the β‐TCP/bioactive glass composites soaked in SBF indicated superior bioactivity of these materials compared to pure β‐TCP without any precipitation. The ability of β‐TCP/bioactive glass composites to support the growth of human osteoblastic cells was considerably better than that of pure β‐TCP. These results may be used to indicate which compositions and processing conditions can provide appropriate materials for hard tissue regeneration. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Human hair follicle pluripotent stem (hfPS) cells promote regeneration of peripheral‐nerve injury: An advantageous alternative to ES and iPS cells
Authors: Amoh Yasuyuki , Kanoh Maho , Niiyama Shiro , Hamada Yuko , Kawahara Katsumasa , Sato Yuichi , Hoffman Robert M. , Katsuoka Kensei
Published: June 2009

The optimal source of stem cells for regenerative medicine is a major question. Embryonic stem (ES) cells have shown promise for pluripotency but have ethical issues and potential to form teratomas. Pluripotent stem cells have been produced from skin cells by either viral‐, plasmid‐ or transposon‐mediated gene transfer. These stem cells have been termed induced pluripotent stem cells or iPS cells. iPS cells may also have malignant potential and are inefficiently produced. Embryonic stem cells may not be suited for individualized therapy, since they can undergo immunologic rejection. To address these fundamental problems, our group is developing hair follicle pluripotent stem (hfPS) cells. Our previous studies have shown that mouse hfPS cells can differentiate to neurons, glial cells in vitro, and other cell types, and can promote nerve and spinal cord regeneration in vivo. hfPS cells are located above the hair follicle bulge in what we have termed the hfPS cell area (hfPSA) and are nestin positive and keratin 15 (K‐15) negative. Human hfPS cells can also differentiate into neurons, glia, keratinocytes, smooth muscle cells, and melanocytes in vitro. In the present study, human hfPS cells were transplanted in the severed sciatic nerve of the mouse where they differentiated into glial fibrillary‐acidic‐protein (GFAP)‐positive Schwann cells and promoted the recovery of pre‐existing axons, leading to nerve generation. The regenerated nerve recovered function and, upon electrical stimulation, contracted the gastrocnemius muscle. The hfPS cells can be readily isolated from the human scalp, thereby providing an accessible, autologous and safe source of stem cells for regenerative medicine that have important advantages over ES or iPS cells. J. Cell. Biochem. 107: 1016–1020, 2009. © 2009 Wiley‐Liss, Inc.
The immunoglobulin‐like cell adhesion molecule hepaCAM induces differentiation of human glioblastoma U373‐MG cells
Authors: Lee Lay Hoon , Moh Mei Chung , Zhang Ting , Shen Shali
Published: June 2009

Subsequent to our identification of a novel immunoglobulin‐like cell adhesion molecule hepaCAM, we showed that hepaCAM is frequently lost in diverse human cancers and is capable of modulating cell motility and growth when re‐expressed. Very recently, a molecule identical to hepaCAM (designated as GlialCAM) was found highly expressed in glial cells of the brain. Here, we demonstrate that hepaCAM is capable of inducing differentiation of the human glioblastoma U373‐MG cells. Expression of hepaCAM resulted in a significant increase in the astrocyte differentiation marker glial fibrillary acid protein (GFAP), indicating that hepaCAM promotes glioblastoma cells to undergo differentiation. To determine the relationship between hepaCAM expression level and cell differentiation, we established two U373‐MG cell lines expressing hepaCAM at different levels. The results revealed that high‐level hepaCAM triggered a clear increase in GFAP expression as well as morphological changes characteristic of glioblastoma cell differentiation. Furthermore, high expression of hepaCAM significantly accelerated cell adhesion but inhibited cell proliferation and migration. Concomitantly, deregulation of cell cycle regulatory proteins was detected. Expectedly, the differentiation was noticeably less apparent in cells expressing low‐level hepaCAM. Taken together, our findings suggest that hepaCAM induces differentiation of the glioblastoma U373‐MG cells. The degree of cell differentiation is dependent on the expression level of hepaCAM. J. Cell. Biochem. 107: 1129–1138, 2009. © 2009 Wiley‐Liss, Inc.
Involvement of mitochondria and metacaspase elevation in harpinPss‐induced cell death of Saccharomyces cerevisiae
Authors: Sripriya Paranthaman , Vedantam Lakshmi Vasudev , Podile Appa Rao
Published: June 2009

Expression of a proteinaceous elicitor harpinPss, encoded by hrpZ of Pseudomonas syringae pv. syringae 61, under GAL1 promoter in Saccharomyces cerevisiae Y187 resulted in galactose‐inducible yeast cell death (YCD). Extracellular treatment of harpin did not affect the growth of yeast. The observed YCD was independent of the stage of cell cycle. “Petite” mutant of S. cerevisiae Y187 pYEUT‐hrpZ was insensitive to cell death indicating the involvement of mitochondria in this YCD. Loss in mitochondrial potential, but no leakage of Cytochrome c from mitochondria into the cytosol, were notable features in harpinPss‐induced YCD. Cyclosporin A had no effect on hrpZ expressing yeast cells, further confirmed that there was no release of Cytochrome c. Elevation of caspase activity has been reported for the first time in this form of cell death induced by harpin expression. Release of reactive oxygen species and clear loss of membrane integrity were evident with the absence of nuclear fragmentation and chromosomal condensation, while annexin V and propidium iodide staining showed features typical of necrosis. J. Cell. Biochem. 107: 1150–1159, 2009. © 2009 Wiley‐Liss, Inc.
Effects of fibre type and diffusion distance on mouse skeletal muscle glycogen content in vitro
Authors: Sogaard Peter , Szekeres Ferenc , Holmström Maria , Larsson Dennis , Harlén Mikael , Garcia‐Roves Pablo , Chibalin Alexander V.
Published: June 2009

In vitro incubation of isolated rodent skeletal muscle is a widely used procedure in metabolic research. One concern with this method is the development of an anoxic state during the incubation period that can cause muscle glycogen depletion. Our aim was to investigate whether in vitro incubation conditions influence glycogen concentration in glycolytic extensor digitorum longus (EDL) and oxidative soleus mouse muscle. Quantitative immunohistochemistry was applied to assess glycogen content in incubated skeletal muscle. Glycogen concentration was depleted, independent of insulin‐stimulation in the incubated skeletal muscle. The extent of glycogen depletion was correlated with the oxidative fibre distribution and with the induction of hypoxia‐induced‐factor‐1‐alpha. Insulin exposure partially prevented glycogen depletion in soleus, but not in EDL muscle, providing evidence that glucose diffusion is not a limiting step to maintain glycogen content. Our results provide evidence to suggest that the anoxic milieu and the intrinsic characteristics of the skeletal muscle fibre type play a major role in inducing glycogen depletion in during in vitro incubations. J. Cell. Biochem. 107: 1189–1197, 2009. © 2009 Wiley‐Liss, Inc.
Collection and culture of alveolar bone marrow multipotent mesenchymal stromal cells from older individuals
Authors: Han Juan , Okada Hironori , Takai Hideki , Nakayama Youhei , Maeda Takahide , Ogata Yorimasa
Published: June 2009

In this work, we examined the culture condition of alveolar bone marrow multipotent mesenchymal stromal cells (ABMMSCs), aiming to apply regenerative therapy to older periodontitis patients. To better understand the character of cultured cells from alveolar bone marrow, the expression profiles of well‐known genes and their responses to the induction of osteogenic, chondrogenic, or adipogenic differentiation were examined. Using αMEM‐based culture, ABMMSCs could be obtained from older individuals than in previous reports. Interestingly, ABMMSCs expressing Klf4 were able to differentiate into osteoblasts. The prediction of differentiation potential by Klf4 could be a useful guide for further improvement of the culture conditions required to culture ABMMSCs derived from older individuals. J. Cell. Biochem. 107: 1198–1204, 2009. © 2009 Wiley‐Liss, Inc.
Biomarkers for prostate cancer
Authors: Leman Eddy S. , Getzenberg Robert H.
Published: June 2009

The detection of prostate cancer using a blood test has by many standards changed the face of the disease. Despite this tremendous success, there are limitations attributed to the use of prostate specific antigen (PSA) as a means to screen and detect prostate cancer. PSA, as its name implies, is not specific for prostate cancer and as such is often found elevated in other prostatic diseases/symptoms associated with the aging male. Clearly, more specific marker(s) that could identify which individuals actually have prostate cancer and differentiate them from those without the disease would be of tremendous value. The search for more accurate and clinically useful biomarkers of prostate cancer has been extensive. This has focused on individual markers, as well as groups of markers. Included among these are PSA isoforms, pathological indicators and stains, nucleic acids and others. This article highlights the discovery of PSA as a first blood‐based biomarker for prostate cancer detection, as well as other molecular biomarkers and their potential application in detection of the disease. J. Cell. Biochem. 108: 3–9, 2009. © 2009 Wiley‐Liss, Inc.
Pseudolaric acid B suppresses T lymphocyte activation through inhibition of NF‐κB signaling pathway and p38 phosphorylation
Authors: Li Ting , Wong Vincent Kam Wai , Yi Xiao Qin , Wong Yuen Fan , Zhou Hua , Liu Liang
Published: June 2009

Pseudolaric acid B (PAB) is a major bioactive component of the medicinal plant Pseudolarix kaempferi. Traditional medicine practitioners in Asia have been using the roots of this plant to treat inflammatory and microbial skin diseases for centuries. In the current study, in vitro immunosuppressive effect of PAB and the underlying mechanisms have been investigated. The results showed that PAB dose‐dependently suppressed human T lymphocyte proliferation, IL‐2 production and CD25 expression induced by co‐stimulation of PMA plus ionomycin or of anti‐OKT‐3 plus anti‐CD28. Mechanistic studies showed that PAB significantly inhibited nuclear translocation of NF‐κB p65 and phosphorylation and degradation of IκB‐α evoked by co‐stimulation of PMA plus ionomycin. PAB could also suppress the phosphorylation of p38 in the MAPKs pathway. Based on these evidences, we conclude that PAB suppressed T lymphocyte activation through inhibition of NF‐κB and p38 signaling pathways; this would make PAB a strong candidate for further study as an anti‐inflammatory agent. J. Cell. Biochem. 108: 87–95, 2009. © 2009 Wiley‐Liss, Inc.