bluuebunny/crossref_metadata_2025 huggingface dataset:
FcRn in the Yolk Sac Endoderm of Mouse Is Required for IgG Transport to Fetus
Authors: Kim Jonghan , Mohanty Sudhasri , Ganesan Latha P. , Hua Keding , Jarjoura David , Hayton William L. , Robinson John M. , Anderson Clark L.
Published: February 2009

In adults, the nonclassical MHC class I molecule, FcRn, binds both IgG and albumin and rescues both from a degradative fate, endowing both proteins with high plasma concentrations. FcRn also transports IgG from mother to young during gestation. Anticipating that a detailed understanding of gestational IgG transport in the mouse may give us a useful model to understand FcRn function in the human placenta, we have studied FcRn in the mouse yolk sac placenta in detail. Analyzing day 19–20 fetuses of the three FcRn genotypes resulting from matings of FcRn+/− parents, we found that FcRn−/− fetuses showed negligible IgG concentrations (1.5 μg/ml), whereas IgG concentrations in FcRn+/− fetuses were about a half (176 μg/ml) that of FcRn+/+ fetuses (336 μg/ml), indicating that FcRn is responsible for virtually all IgG transport from mother to fetus. Immunofluorescence and immunoblotting studies indicated that FcRn is expressed in the endoderm of the yolk sac placenta but not in other cells of the yolk sac placenta or in the chorioallantoic placenta. IgG was found in the endoderm of both FcRn+/+ and FcRn−/− yolk sac placentas and in the mesenchyme of FcRn+/+ but was missing from the mesenchyme of FcRn−/− yolk sac placentas, indicating that IgG enters the endoderm constitutively but is moved out of the endoderm by FcRn. The similarities of these results to human placental FcRn expression and function are striking.
Antigen Processing and MHC-II Presentation by Dermal and Tumor-Infiltrating Dendritic Cells
Authors: Gerner Michael Y. , Mescher Matthew F.
Published: February 2009

MHC-II presentation by dendritic cells (DC) is necessary both for initial priming of CD4 T cells and for induction of peripheral effector function. Although CD4 T cells can be critical for competent immunization-mediated cancer immunosurveillance, unmanipulated CD4 T cell responses to poorly immunogenic tumors result in either complete ignorance or tolerance induction, suggesting inadequate DC function. In this study, we investigated the phenotype, Ag uptake, and MHC-II presentation capacity of normal dermal DC and tumor-infiltrating DC (TIDC) in both lymphoid and peripheral sites. We found that murine tumors were extensively infiltrated by partially activated TIDC that closely resembled dermal DC by surface marker expression. However, in contrast to dermal DC, TIDC were inefficient at MHC-II presentation due to poor intrinsic protein uptake capability. This resulted in both inferior initiation of T cell responses in the draining lymph node and poor peripheral effector cell accumulation. In addition, TLR stimulation selectively enhanced MHC-II presentation of Ag by dermal DC, but not TIDC in the draining lymph node, and did not affect overall peripheral Ag uptake of either. These results show that TIDC are functionally distinct from normal interstitial DC, thus indicating that neoplastic tissues can evade effector CD4 T cells through modification of DC competence.
Selective Inhibition of CCR2 Expressing Lymphomyeloid Cells in Experimental Autoimmune Encephalomyelitis by a GM-CSF-MCP1 Fusokine
Authors: Rafei Moutih , Campeau Philippe M. , Wu Jian Hui , Birman Elena , Forner Kathy , Boivin Marie-Noelle , Galipeau Jacques
Published: February 2009

We describe the generation of a fusion cytokine consisting of GM-CSF in tandem with N-terminal-truncated MCP-1 (6-76), hereafter GMME1. Treatment of activated T cells with recombinant GMME1 protein leads to proinflammatory cytokine reduction and apoptosis via a CCR2-restricted pathway. Similarly, cell death is triggered in macrophages cultured with GMME1, while an inhibition of Ab production from plasma cells is observed. Treatment of CD4 T cells derived from experimental autoimmune encephalomyelitis mice with GMME1 leads to p38 hyperphosphorylation, inhibition of p44/42, AKT and STAT3 phosphorylation, and caspase-3 activation. GMME1 administration to experimental autoimmune encephalomyelitis mice suppresses symptomatic disease and correlates with decreased levels of inflammatory cytokines including IL-17, MOG-specific Ab titers, and blockade of CD4 and CD8 T cell infiltration in spinal cords. We propose that GMME1 defines a new class of agents for the treatment of autoimmune ailments by selectively targeting lymphomyeloid cells expressing CCR2.
Bone Marrow Chimeras and c-fms Conditional Ablation (Mafia) Mice Reveal an Essential Role for Resident Myeloid Cells in Lipopolysaccharide/TLR4-Induced Corneal Inflammation
Authors: Chinnery Holly R. , Carlson Eric C. , Sun Yan , Lin Michelle , Burnett Sandra H. , Perez Victor L. , McMenamin Paul G. , Pearlman Eric
Published: February 2009

The mammalian cornea contains an extensive network of resident macrophages and dendritic cells. To determine the role of these cells in LPS-induced corneal inflammation, TLR4−/− mice were sublethally irradiated and reconstituted with bone marrow cells from either enhanced GFP (eGFP)+/C57BL/6 or eGFP+/TLR4−/− mice. The corneal epithelium was abraded, LPS was added topically, and cellular infiltration to the corneal stroma and development of corneal haze were examined after 24 h. TLR4−/− mice reconstituted with C57BL/6, but not TLR4−/− bone marrow cells donor cells were found to cause infiltration of eGFP+ cells to the cornea, including neutrophils, and also increased corneal haze compared with saline-treated corneas. In a second experimental approach, corneas of transgenic macrophage Fas induced apoptosis (Mafia) mice were stimulated with LPS. These mice express eGFP and a suicide gene under control of the c-fms promoter, and systemic treatment with the FK506 dimerizer (AP20187) causes Fas-mediated apoptosis of monocytic cells. AP20187-treated mice had significantly fewer eGFP+ cells in the cornea than untreated mice. After stimulation with LPS neutrophil recruitment and development of corneal haze were impaired in AP20187-treated mice compared with untreated controls. Furthermore, LPS induced CXCL1/KC and IL-1α production within 4 h in corneas of untreated Mafia mice, which is before cellular infiltration; however, cytokine production was impaired after AP20187 treatment. Together, results from both experimental approaches demonstrate an essential role for resident corneal monocytic lineage cells (macrophages and dendritic cells) in development of corneal inflammation.
Preferential Use of B7.2 and Not B7.1 in Priming of Vaccinia Virus-Specific CD8 T Cells
Authors: Salek-Ardakani Shahram , Arens Ramon , Flynn Rachel , Sette Alessandro , Schoenberger Stephen P. , Croft Michael
Published: February 2009

Recent studies have demonstrated that CD28 provides critical costimulatory signals required for optimal CD8 T cell expansion and effector function in response to several viruses, including influenza, HSV, and vaccinia virus (VACV). CD28 has two ligands expressed largely on professional APC, named B7.1 (CD80) and B7.2 (CD86). Although some results suggest that these ligands are equivalent and both promote CD28 signaling, it is not clear whether they are equally important for priming of antiviral T cells. Herein we show that B7.2 is critical for early CD8 T cell responses to both dominant and subdominant VACV epitopes, correlating with its strong induction on CD8α+ dendritic cells. In contrast, B7.1 plays no significant role. Signals from an exogenously applied adjuvant can recruit B7.1 activity and lead to further enhanced priming of VACV-reactive CD8 T cells. However, during a natural infection, B7.1 is not functional, likely related to inefficient up-regulation or active suppression by VACV. These studies provide evidence that B7.2 is the major ligand for the CD28 receptor on VACV-specific CD8 T cells, that B7.2 can promote efficient CD8 T cell priming without B7.1, and that B7.1 and B7.2 can be differentially utilized during antiviral responses.
Mapping of a Microbial Protein Domain Involved in Binding and Activation of the TLR2/TLR1 Heterodimer
Authors: Liang Shuang , Hosur Kavita B. , Lu Shanyun , Nawar Hesham F. , Weber Benjamin R. , Tapping Richard I. , Connell Terry D. , Hajishengallis George
Published: February 2009

The pentameric B subunit of type IIb Escherichia coli enterotoxin (LT-IIb-B5), a doughnut-shaped oligomeric protein from enterotoxigenic E. coli, activates the TLR2/TLR1 heterodimer (TLR2/1). We investigated the molecular basis of the LT-IIb-B5 interaction with TLR2/1 to define the structure-function relationship of LT-IIb-B5 and, moreover, to gain an insight into how TLR2/1 recognizes large, nonacylated protein ligands that cannot fit within its lipid-binding pockets, as previously shown for the Pam3CysSerLys4 (Pam3CSK4) lipopeptide. We first identified four critical residues in the upper region of the LT-IIb-B5 pore. Corresponding point mutants (M69E, A70D, L73E, S74D) were defective in binding TLR2 or TLR1 and could not activate APCs, despite retaining full ganglioside-binding capacity. Point mutations in the TLR2/1 dimer interface, as determined in the crystallographic structure of the TLR2/1-Pam3CSK4 complex, resulted in diminished activation by both Pam3CSK4 and LT-IIb-B5. Docking analysis of the LT-IIb-B5 interaction with this apparently predominant activation conformation of TLR2/1 revealed that LT-IIb-B5 might primarily contact the convex surface of the TLR2 central domain. Although the TLR1/LT-IIb-B5 interface is relatively smaller, the leucine-rich repeat motifs 9–12 in the central domain of TLR1 were found to be critical for cooperative TLR2-induced cell activation by LT-IIb-B5. Moreover, the putative LT-IIb-B5 binding site overlaps partially with that of Pam3CSK4; consistent with this, Pam3CSK4 suppressed TLR2 binding of LT-IIb-B5, albeit not as potently as self-competitive inhibition. We identified the upper pore region of LT-IIb-B5 as a TLR2/1 interactive domain, which contacts the heterodimeric receptor at a site that is distinct from, although it overlaps with, that of Pam3CSK4.
Analysis of Adhesion Molecules, Target Cells, and Role of IL-2 in Human FOXP3+ Regulatory T Cell Suppressor Function
Authors: Tran Dat Q. , Glass Deborah D. , Uzel Gulbu , Darnell Dirk A. , Spalding Christine , Holland Steven M. , Shevach Ethan M.
Published: February 2009

FOXP3+ regulatory T cells (Tregs) are central to the maintenance of self-tolerance and immune homeostasis. The mechanisms of action and cellular targets for Treg-mediated suppression remain controversial. The critical adhesion molecules utilized by Tregs for the interaction with their target cells have not been well characterized. We show that human CD4+FOXP3+CD25high cells (hTregs) suppress the activation of mouse responders as efficiently as mouse Tregs. LFA-1 (CD11a/CD18) on the hTregs is critical for their suppressor function, since suppression can be reversed with blocking anti-hCD11a or anti-hCD18 mAb. Tregs from patients with LFA-1 deficiency fail to suppress human and mouse responders. Mouse CD4+ T cells deficient in ICAM-1 can be suppressed by hTregs, indicating that the hTregs target mouse dendritic cells (DCs) through the binding of human LFA-1 to mouse ICAM-1. Coculture of mouse DCs with hTregs, but not hTregs from LFA-1-deficient patients, prevented the up-regulation of CD80/CD86 on the DCs and their capacity to activate responder T cells. Lastly, IL-2 is not required for hTreg suppressor function under optimal stimulatory condition and IL-2 consumption plays no role in hTreg-mediated suppression. Taken together, one of the mechanisms of Treg-mediated suppression functions across species and mediates an LFA-1/ICAM-1-dependent interaction between Tregs and DCs.
Combined Optical and MR Bioimaging Using Rare Earth Ion Doped NaYF4 Nanocrystals
Authors: Kumar Rajiv , Nyk Marcin , Ohulchanskyy Tymish Y. , Flask Christopher A. , Prasad Paras N.
Published: February 2009

Here, novel nanoprobes for combined optical and magnetic resonance (MR) bioimaging are reported. Fluoride (NaYF4) nanocrystals (20–30 nm size) co‐doped with the rare earth ions Gd3+ and Er3+/Yb3+/Eu3+ are synthesized and dispersed in water. An efficient up‐ and downconverted photoluminescence from the rare‐earth ions (Er3+ and Yb3+ or Eu3+) doped into fluoride nanomatrix allows optical imaging modality for the nanoprobes. Upconversion nanophosphors (UCNPs) show nearly quadratic dependence of the photoluminescence intensity on the excitation light power, confirming a two‐photon induced process and allowing two‐photon imaging with UCNPs with low power continuous wave laser diodes due to the sequential nature of the two‐photon process. Furthermore, both UCNPs and downconversion nanophosphors (DCNPs) are modified with biorecognition biomolecules such as anti‐claudin‐4 and anti‐mesothelin, and show in vitro targeted delivery to cancer cells using confocal microscopy. The possibility of using nanoprobes for optical imaging in vivo is also demonstrated. It is also shown that Gd3+ co‐doped within the nanophosphors imparts strong T1 (Spin‐lattice relaxation time) and T2 (spin‐spin relaxation time) for high contrast MR imaging. Thus, nanoprobes based on fluoride nanophosphors doped with rare earth ions are shown to provide the dual modality of optical and magnetic resonance imaging.
Phototunable Microlens Array Based on Polymer Dispersed Liquid Crystals
Authors: Xiong Gui‐Rong , Han Guo‐Zhi , Sun Cheng , Xu Hua , Wei Hong‐mei , Gu Zhong‐Ze
Published: February 2009

A microfluidic system is designed to fabricate polymer dispersed liquid crystal microspheres, whose shape, surface smoothness, and size are controlled. A microlens array (MLA) is constructed by the assembly of the monodispersed microspheres. In the MLA, each microsphere acts as a separate imaging unit. As the liquid crystal (LC) used is a mixed liquid crystal that contain photoresponsive 4‐butyl‐4‐methoxyazobenzene, the imaging capability and light transportation of the MLA can be reversibly controlled by light irradiation.
High‐Density Carrier Accumulation in ZnO Field‐Effect Transistors Gated by Electric Double Layers of Ionic Liquids
Authors: Yuan Hongtao , Shimotani Hidekazu , Tsukazaki Atsushi , Ohtomo Akira , Kawasaki Masashi , Iwasa Yoshihiro
Published: February 2009

Very recently, electric‐field‐induced superconductivity in an insulator was realized by tuning charge carrier to a high density level (1 × 1014 cm−2). To increase the maximum attainable carrier density for electrostatic tuning of electronic states in semiconductor field‐effect transistors is a hot issue but a big challenge. Here, ultrahigh density carrier accumulation is reported, in particular at low temperature, in a ZnO field‐effect transistor gated by electric double layers of ionic liquid (IL). This transistor, called an electric double layer transistor (EDLT), is found to exhibit very high transconductance and an ultrahigh carrier density in a fast, reversible, and reproducible manner. The room temperature capacitance of EDLTs is found to be as large as 34 µF cm−2, deduced from Hall‐effect measurements, and is mainly responsible for the carrier density modulation in a very wide range. Importantly, the IL dielectric, with a supercooling property, is found to have charge‐accumulation capability even at low temperatures, reaching an ultrahigh carrier density of 8×1014 cm−2 at 220 K and maintaining a density of 5.5×1014 cm−2 at 1.8 K. This high carrier density of EDLTs is of great importance not only in practical device applications but also in fundamental research; for example, in the search for novel electronic phenomena, such as superconductivity, in oxide systems.
Estimation and evidence in forensic anthropology: Sex and race
Authors: Konigsberg Lyle W. , Algee‐Hewitt Bridget F.B. , Steadman Dawnie Wolfe
Published: February 2009

Forensic anthropology typically uses osteological and/or dental data either to estimate characteristics of unidentified individuals or to serve as evidence in cases where there is a putative identification. In the estimation context, the problem is to describe aspects of an individual that may lead to their eventual identification, whereas in the evidentiary context, the problem is to provide the relative support for the identification. In either context, individual characteristics such as sex and race may be useful. Using a previously published forensic case (Steadman et al. (2006) Am J Phys Anthropol 131:15–26) and a large (N= 3,167) reference sample, we show that the sex of the individual can be reliably estimated using a small set of 11 craniometric variables. The likelihood ratio from sex (assuming a 1:1 sex ratio for the “population at large”) is, however, relatively uninformative in “making” the identification. Similarly, the known “race” of the individual is relatively uninformative in “making” the identification, because the individual was recovered from an area where the 2000 US census provides a very homogenous picture of (self‐identified) race. Of interest in this analysis is the fact that the individual, who was recovered from Eastern Iowa, classifies very clearly with [Howells 1973.Cranial Variation in Man: A Study by Multivariate Analysis of Patterns of Difference Among Recent Human Populations.Cambridge, MA: Peabody Museum of Archaeology and Ethnology; 1989.Skull Shape and the Map: Craniometric Analyses in the Dispersion of Modern Homo. Cambridge, MA: Harvard University Press]. Easter Islander sample in an analysis with uninformative priors. When the Iowa 2000 Census data on self‐reported race are used for informative priors, the individual is clearly identified as “American White.” This analysis shows the extreme importance of an informative prior in any forensic application. Am J Phys Anthropol 2009. © 2009 Wiley‐Liss, Inc.
Understanding race and human variation: Why forensic anthropologists are good at identifying race
Authors: Ousley Stephen , Jantz Richard , Freid Donna
Published: February 2009

American forensicanthropologists uncritically accepted the biological race concept from classic physical anthropology and applied it to methods of human identification. Why and how the biological race concept might work in forensic anthropology was contemplated by Sauer (Soc Sci Med 34 1992 107–111), who hypothesized that American forensic anthropologists are good at what they do because of a concordance between social race and skeletal morphology in American whites and blacks. However, Sauer also stressed that this concordance did not validate the classic biological race concept of physical anthropology that there are a relatively small number of discrete types of human beings. Results from Howells (Papers of the Peabody Museum of Archaeology and Ethnology 67 1973 1–259; Papers of the Peabody Museum of Archaeology and Ethnology 79 1989 1–189; Papers of the Peabody Museum of Archaeology and Ethnology 82 1995 1–108) and others using craniometric and molecular data show strong geographic patterning of human variation despite overlap in their distributions. However, Williams et al. (Curr Anthropol 46 2005 340–346) concluded that skeletal morphology cannot be used to accurately classify individuals. Williams et al. cited additional support from Lewontin (Evol Biol 6 1972 381–398), who analyzed classic genetic markers. In this study, multivariate analyses of craniometric data support Sauer's hypothesis that there are morphological differences between American whites and blacks. We also confirm significant geographic patterning in human variation but also find differences among groups within continents. As a result, if biological races are defined by uniqueness, then there are a very large number of biological races that can be defined, contradicting the classic biological race concept of physical anthropology. Further, our results show that humans can be accurately classified into geographic origin using craniometrics even though there is overlap among groups. Am J Phys Anthropol 2009. © 2009 Wiley‐Liss, Inc.
Ultraschnelle Klickkonjugation von makromolekularen Bausteinen bei Raumtemperatur
Authors: Inglis Andrew J. , Sinnwell Sebastian , Stenzel Martina H. , Barner‐Kowollik Christopher
Published: February 2009

Blockcopolymere in Sekundenschnelle: Eine katalysatorfreie Klickkonjugation einzelner Polymerketten gelingt bei Raumtemperatur mithilfe neuer, durch ATRP hergestellter Polymere mit Cyclopentadienyl‐Endfunktionen. Dabei werden diese Polymere durch eine äußerst schnelle heterogene Diels‐Alder‐Cycloaddition mit durch RAFT hergestellten Makromolekülen umgesetzt, die elektronenarme Dithioester‐Endfunktionen aufweisen.

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A Reevaluation of the Ambident Reactivity of the Guanine Moiety Towards Hydroxyl Radicals
Authors: Chatgilialoglu Chryssostomos , D'Angelantonio Mila , Guerra Maurizio , Kaloudis Panagiotis , Mulazzani Quinto G.
Published: February 2009

Radically different: Contrary to previous proposals, the main reaction of the HO. radical with guanosine or 2′‐deoxyguanosine is the hydrogen abstraction from the NH2 moiety to give a guanyl radical. This radical, characterized by a broad band in the visible region (around 610 nm), undergoes tautomerization to the most stable isomer.

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Ultrafast Click Conjugation of Macromolecular Building Blocks at Ambient Temperature
Authors: Inglis Andrew J. , Sinnwell Sebastian , Stenzel Martina H. , Barner‐Kowollik Christopher
Published: February 2009

Block copolymers in seconds: Catalyst‐free, ambient‐temperature click conjugation of individual polymer strands becomes possible using novel ATRP‐derived cyclopentadienyl‐capped polymers in an extremely rapid hetero‐Diels–Alder cycloaddition with macromolecules equipped with electron‐deficient dithioester end groups prepared by the RAFT process.

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Reaction kinetics of epoxy resin modified with reactive and nonreactive thermoplastic copolymers
Authors: Man Z. , Stanford J. L. , Dutta Binay K.
Published: February 2009

An epoxy resin system based on a triglycidyl p‐amino phenol (MY0510) was crosslinked using stoichiometric amounts of 4,4′‐diaminodiphenyl sulfone. The epoxy was modified with random copolymers, polyethersulfone‐poly(ether‐ethersulfone) (PES:PEES), with either amine or chlorine end groups, at 10 and 20 wt %. The reaction kinetics for both unmodified and modified epoxy systems were studied using differential scanning calorimetry in isothermal and dynamic conditions. The results show that the degree of conversion in thermoplastic‐modified epoxies at any reaction time is smaller compared with the unmodified resin. Gel point (GP) determination was done from rheological measurements. The modified system containing 20% of the PES:PEES additive showed considerable increase in the GP. The reaction rate shows the characteristic of an autocatalytic reaction where the product acts as catalyst. The activation energy, Ea calculated from the isothermal reaction depends on the extent of conversion and increases with increasing PES:PEES content. For unmodified epoxy system, the average Ea is 67.8 ± 4.1 kJ mol−1 but for systems modified with 20 wt % of amine and chlorine PES:PEES, the value increased to 74.1 ± 3.3 and 77.9 ± 4.4 kJ mol−1, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Removal of Hg2+ from aqueous solution using a novel composite carbon adsorbent
Authors: Chang Yu‐Hsin , Hsieh Kuo‐Huang , Chang Feng‐Chih
Published: February 2009

A novel composite carbon adsorbent (GCA) has been prepared by immobilizing activated carbon and genipin‐crosslinked chitosan into calcium alginate gel beads via entrapment and applied to the removal of mercury (Hg2+) ions from aqueous solution (e.g., drinking water). Two bead sizes and two mixing ratios of components were obtained and characterized. Batch experiments were performed to study the uptake equilibrium and kinetics of Hg2+ ions by the GCA. The Hg2+ adsorption capacity of GCA was found to be dependent of pH and independent of size of the adsorbent. The Hg2+ adsorption rate of GCA increases with decreasing its bead size. However, both adsorption capacity and rate of GCA for Hg2+ increase with increasing its chitosan content. Otherwise, it was shown that the GCA has higher Hg2+ adsorption capacity and rate than activated carbon, which might be caused by the incorporation of chitosan into the GCA. The maximum Hg2+ adsorption capacity of GCA was found to be 576 mg/g, which is over seven times higher than that of activated carbon. Our results reveal the uniform distribution of activated carbon and chitosan within the alginate gel bead and that Hg2+ ions can diffuse inside the bead. It also demonstrated the feasibility of using this GCA for Hg2+ removal at low pH values. The Hg2+ absorbed beads of the GCA can be effectively regenerated and reused using H2SO4. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Nonaqueous polymerization of vinyl chloride: An environmentally friendly process
Authors: Georgiadou S. , Thomas N. L. , Gilbert M. , Brooks B. W.
Published: February 2009

Poly(vinyl chloride) (PVC) is produced via a nonaqueous polymerization process in which hexane is used as a diluent. This nonaqueous process can lead to significant energy savings, significant reductions in carbon dioxide emissions, and the elimination of wastewater. Various suspending agents have been used to evaluate their effects on the shape and morphology of PVC grains. The nonaqueous process leads to the formation of PVC grains with higher porosity than that of typical suspension PVC. The bulk density is slightly lower than that of suspension PVC, but the thermal stability seems to be similar. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Viscoelastic properties of fly ash‐filled natural rubber compounds: Effect of fly ash loading
Authors: Saowapark Thanunya , Sombatsompop Narongrit , Sirisinha Chakrit
Published: February 2009

Fly ash (FA) as a by‐product of power station plants is known to consist of silicon dioxide similar to precipitated silica. The use of FA as filler in natural rubber (NR) was of interest to reinforce and/or reduce product cost. In this article, viscoelastic properties of FA‐filled NR composites with various FA loadings were investigated with the utilization of two different modes of shear flow, namely, oscillatory and steady shear flow. It is found that the addition of FA to NR increases storage modulus (G′) and shear viscosity under both oscillatory and steady shear flow. Moreover, the oscillatory test results exhibit the unexpected increase in magnitude of viscous response with increasing FA loading in FA‐filled NR compounds. The explanation is proposed in terms of the ball‐bearing effect of FA with spherical shape associated with the occurrence of molecular degradation induced by inorganic constituents particularly manganese, iron, and copper in nonrubber component of NR as well as the small amount of heavy metals including iron, copper in FA. An isoprene rubber (IR) containing no nonrubber component was used to validate the proposed explanation. In addition, with the use of Cox‐Merz concept, the results of both complex viscosity under oscillatory shear flow and apparent shear viscosity under steady shear flow can effectively be superimposed in the case of FA‐filled compounds, supporting the promotion of viscous response by FA. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Comparison of thermal properties of ethylene‐norbornene copolymers prepared by batch and semi‐batch processes
Authors: Liu Shaojie , Yao Zhen , Cao Kun
Published: February 2009

Ethylene‐norbornene copolymers (ENCs) with various norbornene (NB) fractions could be synthesized by metallocene catalyst in both batch and semi‐batch processes. The batch process with long reaction time produced the ENC samples having considerable copolymer composition drift (CCD) while the semi‐batch process yielded narrow CCD. Furthermore, the effects of CCD on the resultant ENC's thermal properties were discussed. It was found that the thermal properties were dependent on both the NB fraction in obtained ENC and its CCD. The work demonstrated the importance of controlling CCD in the production of ENCs for superior materials properties. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Rheological behavior and mechanical properties of sawdust/polyethylene composites
Authors: Godard F. , Vincent M. , Agassant J.‐F. , Vergnes B.
Published: February 2009

We have characterized the melt rheological behavior and the solid tensile properties of sawdust/polyethylene composites prepared in an internal mixer. Various concentrations (from 0 to 60 wt %) and three particle sizes have been tested, in presence of a coupling agent (maleic anhydride grafted polyethylene). In the molten state, for each particle size, a mastercurve of the complex viscosity as function of frequency can be plotted, using a shift factor depending on weight fraction. We show that the shift factors can be described by a Krieger‐Dougherty law, leading to a “universal” viscosity law of the Carreau‐Yasuda type. In the solid state, the presence of sawdust increases Young modulus in uniaxial elongation, mainly for small size particles, but reduces dramatically deformation at break and tensile strength. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and characterization of bis(4‐cyanato‐3,5‐dimethylphenyl)anisylmethane/epoxy/glass fiber composites
Authors: Jayakumari L. S. , Sampath P. S. , Sarojadevi M.
Published: February 2009

Bis(4‐cyanato‐3,5‐dimethylphenyl)anisylmethane was prepared by treating CNBr with bis(4‐hydroxy‐3,5‐dimethylphenyl)anisylmethane and blended with commercial epoxy resin in different ratios and cured at 120°C for 2 h, 180°C for 1 h, and postcured at 220°C for 1 h using diamino diphenyl methane as curing agent. Castings of neat resin and blends were prepared and characterized. The composite laminates were also fabricated with glass fiber using the same composition. The tensile strength of the composites increased with increase in cyanate content (3, 6, and 9%) from 322 to 355 MPa. The fracture toughness values also increased from 0.7671 kJ/m2, for neat epoxy resin, to 0.8615 kJ/m2, for 9% cyanate ester‐modified epoxy system. The 10% weight loss temperature of pure epoxy (358°C) was increased to 390°C by the incorporation of cyanate ester resin. The incorporation of cyanate ester up to 9% in the epoxy resin increases the Tg from 143 to 147°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Vascular Endothelial Growth Factor D and Intratumoral Lymphatics as Independent Prognostic Factors in Epithelial Ovarian Carcinoma
Authors: Li Lichun , Liu Baoquan , Li Xuemei , Yang Shucai , Xiao Jianbing , Chen Mingwei , Zhang Yafang , Ma Jing
Published: February 2009

Lymph node metastasis is an important prognostic indicator for disease progression and is crucial for therapeutic strategies of epithelial ovarian carcinoma. Vascular endothelial growth factor (VEGF)‐D has been confirmed to have potent lymphangiogenic function in experimental models, but the role in the progression of human ovarian carcinoma remains presently controversial. The purpose of this study was to investigate the prognostic significance of VEGF‐D and the presence of intratumoral lymphatics in patients with epithelial ovarian carcinoma. The VEGF‐D expression was evaluated by immunohistochemistry in 78 specimens of epithelial ovarian carcinoma and tumoral lymphatic vessels were measured by D2‐40. The expression of VEGF‐D protein was detected in the cytoplasm of the tumor cells and in stroma occasionally. The high expression of VEGF‐D was closely associated with the FIGO stage, intratumoral lymphatic vessels, tumoral lymphatic invasion, and lymph node metastasis as well as a shorter overall survival. Univariate and multivariate analysis indicated that VEGF‐D, intratumoral lymphatics, and lymphatic invasion were independent prognostic factors for overall survival and disease‐free survival in patients with epithelial ovarian carcinoma. We conclude that VEGF‐D plays an essential role in tumoral lymphangiogenesis and lymphatic spread, VEGF‐D expression, and the intratumoral lymphatics may be clinically useful indicators for prognostic evaluation in patients with epithelial ovarian carcinoma. Anat Rec, 2009. © 2009 Wiley‐Liss, Inc.
Role of Protease Activated Receptor 2 in Experimental Acute Lung Injury and Lung Fibrosis
Authors: Su Xiao , Matthay Michael A.
Published: February 2009

Protease activated receptor 2 (PAR2) is widely‐distributed (lung, liver, kidney, etc.) and expressed by variety of cells (i.e. leukocytes, epithelial cells, endothelial cells, and fibroblast). PAR2 may participate in many pathological processes, such as, inflammation, injury, as well as fibrosis. Therefore, in this study, we tested whether PAR2 would exert a role in acid‐induced acute lung injury, E. coli pneumonia, bleomycin‐induced acute lung injury and fibrosis. Acid, E. coli, or bleomycin were intratracheally instilled into the lungs of both wildtype and PAR2 knockout mice to detect differences in pulmonary edema, lung vascular permeability, lung fibrosis, and other parameters. Knockout of PAR2 did not affect the extent of pulmonary edema and lung vascular permeability in acid‐induced acute lung injury. Also, both activation of PAR2 in the airspaces of the lung and deletion of PAR2 did not alter the magnitude of pulmonary edema and lung vascular permeability in E. coli pneumonia. Finally, PAR2 deficiency did not affect the severity of lung inflammation and lung fibrosis in bleomycin‐induced acute lung injury and lung fibrosis models. Thus, PAR2 does not appear to play a critical role in the pathogeneses of experimental acid‐induced acute lung injury, E. coli pneumonia, and bleomycin‐induced acute lung injury and pulmonary fibrosis in mice. Anat Rec, 2009. © 2009 Wiley‐Liss, Inc.
A novel strategy for obtaining kanamycin resistance in Arabidopsis thaliana by silencing an endogenous gene encoding a putative chloroplast transporter
Authors: Aufsatz Werner , Nehlin Lilian , Voronin Viktor , Schmidt Agnes , Matzke Antonius J. M. , Matzke Marjori
Published: February 2009

The use of bacterial antibiotic resistance markers in transgenic plants raises concerns about horizontal gene transfer to soil bacteria. We report here that kanamycin resistance in Arabidopsis thaliana can be achieved by silencing an endogenous gene encoding a putative chloroplast transporter, which presumably imports kanamycin into chloroplasts to interfere with ribosomal RNA. Homologs of the transporter exist in other plant species, suggesting this strategy may be generally useful for selecting transformed plant cells.
Cell lysis methods for high‐throughput screening or miniaturized assays
Authors: Lin Zhanglin , Cai Zhen
Published: February 2009

The widely and routinely used cell lysis techniques are still being evolved to address the technical needs of micro‐scale sample processing, for example in high‐throughput screening or miniaturized assays. This review focuses on several recently emerged mechanical, physical and biological methods designed for lysing cells on small scales for screening or analysis.
Emerging trends in plasma‐free manufacturing of recombinant protein therapeutics expressed in mammalian cells
Authors: Grillberger Leopold , Kreil Thomas R. , Nasr Sonia , Reiter Manfred
Published: February 2009

Mammalian cells are the expression system of choice for therapeutic proteins, especially those requiring complex post‐translational modifications. Traditionally, these cells are grown in medium supplemented with serum and other animal‐ or human‐derived components to support viability and productivity. Such proteins are also typically added as excipients and stabilizers in the final drug formulation. However, the transmission of hepatitis B in the 1970s and of hepatitis C and HIV in the 1980s through plasma‐derived factor VIII concentrates had catastrophic consequences for hemophilia patients. Thus, due to regulatory concerns about the inherent potential for transmission of infectious agents as well as the heterogeneity and lack of reliability of the serum supply, a trend has emerged to eliminate the use of plasma‐derived additives in the production and formulation of recombinant protein therapeutics. This practice began with products used in the treatment of hemophilia and is progressively expanding throughout the entire industry. The plasma‐free method of producing recombinant therapeutics is accomplished by the use of both cell culture media and final product formulations that do not contain animal‐ or human‐derived additives. A number of recombinant therapeutic proteins for the treatment of several different diseases have been produced by plasma‐free processes, with the objective of improving safety by eliminating blood‐borne pathogens or by reducing immunogenicity. This review describes the factors that drove the development of plasma‐free protein therapeutics and provides examples of advances in manufacturing that have made possible the removal of human and animal‐derived products from all steps of recombinant protein production.
Extracting cancer cell line electrochemical parameters at the single cell level using a microfabricated device
Authors: Alqabandi Jassim A. , Abdel‐Motal Ussama M. , Youcef‐Toumi Kamal
Published: February 2009

Cancer cells have distinctive electrochemical properties. This work sheds light on the system design aspects and key challenges that should be considered when experimentally analyzing and extracting the electrical characteristics of a tumor cell line. In this study, we developed a cellularbased functional microfabricated device using lithography technology. This device was used to investigate the electrochemical parameters of cultured cancer cells at the single‐cell level. Using impedance spectroscopy analyses, we determined the average specific capacitance and resistance of the membrane of the cancer cell line B16‐F10 to be 1.154 ± 0.29 μF/cm2, and 3.9 ± 1.15 KΩ.cm2 (mean ± SEM, n =14 cells), respectively. The consistency of our findings via different trails manifests the legitimacy of our experimental procedure. Furthermore, the data were compared with a proposed constructed analytical‐circuit model. The results of this work may greatly assist researchers in defining an optimal procedure while extracting electrical properties of cancer cells. Detecting electrical signals at the single cell level could lead to the development of novel approaches for analysis of malignant cells in human tissues and biopsies.
Meeting reports
Authors: Cicchetti Gregor
Published: February 2009

Meeting report: 48th meeting of the ASCB

Meeting highlight: Genome Informatics (GIW‐2008); 19th International Conference on Genome Informatics

Darwin 200 years
Design of metal‐binding sites onto self‐assembled peptide fibrils
Authors: Kasotakis Emmanouil , Mossou Estelle , Adler‐Abramovich Lihi , Mitchell Edward P. , Forsyth V. Trevor , Gazit Ehud , Mitraki Anna
Published: February 2009

The ability to develop a rational basis for the binding of inorganic materials to specific binding sites within self‐assembling biological scaffolds has important applications in nanobiotechnology. Amyloid‐forming peptides are a class of such scaffolds and show enormous potential as templates for the fabrication of low resistance, conducting nanowires. Here we report the use of a self‐assembling peptide building block as scaffold for the systematic introduction of metal‐binding residues at specific locations within the structure. The octapeptide NSGAITIG (Asparagine‐Serine‐Glycine‐Alanine‐Isoleucine‐Threonine‐Isoleucine‐Glycine) from the fiber protein of adenovirus has been identified in previous structural studies as an elementary fibril‐forming building block. Using this building block as a scaffold, we have designed three new cysteine‐containing octa‐peptides to study their eventual fibril‐forming ability and potential templating of metal nanoparticles. We find that the cysteine substitutions do not alter the fibril‐forming potential of the peptides, and that the fibrils formed bind efficiently to silver, gold, and platinum nanoparticles; furthermore, we report unexpected behavior of serine in nucleating gold and platinum nanoparticles. We find that combination of cysteine and serine residues projecting from adjacent sites on a peptide scaffold represents a potentially useful strategy in nucleating inorganic materials. The ability to reliably produce metal‐coated fibrils is a vital first step towards the exploitation of these fibrils as conducting nanowires with applications in nano‐circuitry. Short, biologically inspired self‐assembling peptide scaffolds derived from natural fibrous proteins with known three‐dimensional structure may provide a viable approach towards the rational design of inorganic nanowires. © 2009 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 92: 164–172, 2009.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Peptidic modulators of protein‐protein interactions: Progress and challenges in computational design
Authors: Rubinstein Mor , Niv Masha Y.
Published: February 2009

With the decline in productivity of drug‐development efforts, novel approaches to rational drug design are being introduced and developed. Naturally occurring and synthetic peptides are emerging as novel promising compounds that can specifically and efficiently modulate signaling pathways in vitro and in vivo. We describe sequence‐based approaches that use peptides to mimic proteins in order to inhibit the interaction of the mimicked protein with its partners. We then discuss a structure‐based approach, in which protein‐peptide complex structures are used to rationally design and optimize peptidic inhibitors. We survey flexible peptide docking techniques and discuss current challenges and future directions in the rational design of peptidic inhibitors. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 505–513, 2009.

This article was originally published online as an accepted preprint. The “Published Online”date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Trifluoroethanol reveals helical propensity at analogous positions in cytoplasmic domains of three connexins
Authors: Fort Alfredo G. , Spray David C.
Published: February 2009

Cytoplasmic domains of gap junction proteins (connexins) are involved in channel gating, voltage and pH sensitivity, and contain binding sites for partner proteins. However, their secondary structure is incompletely characterized and comparisons among the connexins is totally lacking. Circular dichroism (CD) was used to study the conformational properties of synthetic peptides corresponding to the highly divergent amino acid sequences of cytoplasmic domains of connexin (Cx)32, Cx36, and Cx43. We report that whereas peptides were largely unstructured in aqueous buffer, certain peptides in 30% trifluoroethanol (TFE) showed considerable helical content. These structured peptides correspond to analogous regions in each of the three connexin cytoplasmic domains. This first comparative study of conformational properties of connexin cytoplasmic domains reveals protein domains that may play similar roles in channel function and protein‐protein interactions. © 2009 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 92: 173–182, 2009.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Crystal structure of bovine 3‐hydroxyanthranilate 3,4‐dioxygenase
Authors: Đilović Ivica , Gliubich Francesca , Malpeli Giorgio , Zanotti Giuseppe , Matković‐Čalogović Dubravka
Published: February 2009

3‐Hydroxyanthranilate 3,4‐dioxygenase, the enzyme that catalyzes the conversion of 3‐hydroxyanthranilate to quinolinic acid, has been extracted and purified from bovine kidney, crystallized and its structure determined at 2.5 Å resolution. The enzyme, which crystallizes in the triclinic P1 space group, is a monomer, characterized by the so‐called cupin fold. The monomer of the bovine enzyme mimics the dimer present in lower species, such as bacteria and yeast, since it is composed of two domains: one of them is equivalent to one monomer, whilst the second domain corresponds to only a portion of it. The active site consists of an iron ion coordinated by two histidine residues, one glutamate and an external ligand, which has been interpreted as a solvent molecule. It is contained in the N‐terminal domain, whilst the function of the C‐terminal domain is possibly structural. The catalytic mechanism very likely has been conserved through all species, since the positions of all residues considered relevant for the reaction are present from bacteria to humans. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 1189–1195, 2009.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Structural and electrostatic characterization of Pariacoto virus: Implications for viral assembly
Authors: Devkota Batsal , Petrov Anton S. , Lemieux Sébastien , Boz Mustafa Burak , Tang Liang , Schneemann Anette , Johnson John E. , Harvey Stephen C.
Published: February 2009

We present the first all‐atom model for the structure of a T = 3 virus, pariacoto virus (PaV), which is a nonenveloped, icosahedral RNA virus and a member of the Nodaviridae family. The model is an extension of the crystal structure, which reveals about 88% of the protein structure but only about 35% of the RNA structure. New modeling methods, combining coarse‐grained and all‐atom approaches, were required for developing the model. Evaluation of alternative models confirms our earlier observation that the polycationic N‐ and C‐terminal tails of the capsid proteins must penetrate deeply into the core of the virus, where they stabilize the structure by neutralizing a substantial fraction of the RNA charge. This leads us to propose a model for the assembly of small icosahedral RNA viruses: nonspecific binding of the protein tails to the RNA leads to a collapse of the complex, in a fashion reminiscent of DNA condensation. The globular protein domains are excluded from the condensed phase but are tethered to it, so they accumulate in a shell around the condensed phase, where their concentration is high enough to trigger oligomerization and formation of the mature virus. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 530–538, 2009.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com