bluuebunny/crossref_metadata_2025 huggingface dataset:
Culture of human umbilical vein endothelial cells on immobilized vascular endothelial growth factor
Authors: Ito Yoshihiro , Hasuda Hirokazu , Terai Hiroshi , Kitajima Takashi
Published: July 2005

Vascular endothelial growth factor (VEGF) was immobilized on substrata in photoreactive gelatin to control the adhesion and growth of vascular endothelial cells. The gelatin and VEGF were mixed in water and cast on a polystyrene dish or a silane‐coated glass plate. The surface was then photoirradiated in the presence or absence of a photomask and washed. Toughness of the immobilized material was confirmed by ethanol treatment. Human umbilical vein endothelial cells (HUVECs) grew on the immobilized VEGF but not on a nontreated surface. Growth of HUVEC increased significantly with an increase in the amount of immobilized VEGF, and the effects were inhibited by treatment with anti‐VEGF antibody. Thus, immobilized VEGF specifically interacted with HUVECs to permit growth in culture. Micropatterning of HUVEC cultures was also achieved using micropattern‐immobilized VEGF. This patterning technique may be useful for the formation of blood vessel networks in vitro. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Bone defect healing with an osteogenic protein‐1 device combined with carboxymethylcellulose
Authors: Cook Stephen D. , Salkeld Samantha L. , Patron Laura P.
Published: July 2005

One consideration for the practical use and application of osteogenic proteins is an effective method of delivery. This study evaluated a putty‐type collagen carrier with recombinant human osteogenic protein‐1 (rhOP‐1) ability to heal canine critical sized (2.5 cm) ulna segmental defects compared to rhOP‐1 with a particulate collagen carrier (OP device). The addition of carboxymethylcellulose (CMC) to the particulate collagen carrier (OPCMC device) to form the putty consistency was evaluated in two doses (3.5 and 1.75 mg rhOP‐1/g carrier). The CMC greatly improved the intraoperative handling and site containment of the device. For the one‐half dose and full‐dose sites there were no statistically significant differences in the radiographic grading of defect healing when treated with the particulate OP‐1 device and the device with CMC added. However, there was a dose effect with greater and earlier new bone formation observed with increased rhOP‐1. Mechanically, there were no differences between particulate and putty formulations, although again, a significant effect was observed for treatment dose with the full‐dose OPCMC device restoring 94% of the strength of the intact ulna compared to only 65% for the identical one‐half dose implant. Regardless of rhOP‐1 dose, the quality of union grading and total histologic score appearance were improved with the addition of CMC, although differences in histologic scoring were not statistically significant. Overall, the radiographic, mechanical, and histologic bone‐healing characteristics with the one‐half dose OPCMC device were similar to sites treated with the full‐dose OP device. The observed improvement in healing may allow for lesser amounts of the device or a device with less rhOP‐1 to be used. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Micromechanics of shelf‐aged and retrieved UHMWPE tibial inserts: Indentation testing, oxidative profiling, and thickness effects
Authors: Wernlé James D. , Gilbert Jeremy L.
Published: July 2005

Understanding the surface micromechanical properties of ultra‐high‐molecular‐weight polyethylene (UHMWPE) may allow for improvement in its wear characteristics. Microtomed sections of two UHMWPE tibial bearings, one that had been irradiation sterilized and shelf‐aged, and the other irradiation sterilized and used in a patient, were subjected to depth sensing indentation testing. The microtomed sections exhibited a white band in the subsurface region that is characteristic of oxidation, and the indentation testing, followed by FTIR analysis at the same testing locations, was performed across this region and into the bulk of the material. Indentation testing yielded data leading to hardness, modulus, and energy dissipation factor (EDF). FTIR profiling generated information about oxidation; oxidation indices were calculated by taking a ratio of peak heights at 1716 cm−1 (ketone) to 2022 cm−1 (methylene). The mechanical properties showed a strong linear correlation with oxidation index above a minimum thickness. Modulus, hardness, and EDF all increased with increasing oxidation. The appropriate thickness‐to‐indentation‐depth ratio was determined by two methods and was found to be approximately 20:1. The mechanical properties through the oxidized region were seen to vary with depth into the sample in a profile similar to the oxidation profile. The differing aging environments of the tibial bearings are hypothesized to have had an effect on both the mechanical and oxidation profiles. The retrieved bearing exhibited a narrower oxidation profile with peaks closer to the surface, and oxidation indices of lower magnitude. The mechanical properties proved similar, with less intense and narrower readings for the retrieved sample. This research is consistent with much of the literature. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Fluoride coatings on orthodontic wire for controlled release of fluorine ion
Authors: Lee Su‐Hee , Kim Hae‐Won , Kong Young‐Min , Kim Hyoun‐Ee , Lee Sung‐Ho , Chang Young‐Il
Published: July 2005

The purpose of this study was to develop a new method of releasing fluorine in a controlled manner for applications in the field of orthodontic Ti‐based wire, namely the coating of fluorides on Ti. Thin films of two fluoride compounds, CaF2 and MgF2, were coated on Ti via the electron‐beam evaporation method. The fluorine was released rapidly from the as‐deposited MgF2 coating within a short period, and then the release rate slowed down. When the MgF2 coating was heat treated, this initial burst effect was decreased, but a significant amount of cracks were generated. On the other hand, in the case of the as‐deposited CaF2 coating, fluorine was released linearly for the entire period, without an initial burst. In the heat‐treated CaF2 coatings the trend was similarly observed. The linear fluorine release from the CaF2 coatings, even in the as‐deposited state, was attributed to the high degree of crystallinity of the coatings. A preliminary cell test showed favorable cell viability on both the fluoride coatings. Given their sustained and controlled fluorine release, these fluoride coatings, particularly CaF2, are suggested to be potentially useful in the field of orthodontic Ti‐based wire. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Apatite formed on/in agarose gel as a bone‐grafting material in the treatment of periodontal infrabony defect
Authors: Tabata Masashi , Shimoda Toru , Sugihara Kazumasa , Ogomi Daisuke , Ohgushi Hajime , Akashi Mitsuru
Published: July 2005

The present study was designed to evaluate the effects of a hydroxyapatite/agarose (HA/agarose) composite gel formed by a novel alternate soaking process for the treatment of periodontal infrabony defects in three dogs. After creating two‐wall infrabony periodontal defects on the medial aspect of the maxillary and mandibular second and forth premolars, the defects were implanted with temporary dental filling material (stopping) to induce inflammatory periodontal disease. Two months later, the mucoperiosteal flaps were raised, and after debridement, the infrabony defects were filled with one of the following three materials: (a) HA/agarose, (b) Bone ject (True‐Bone Ceramic‐collagen combined bone graft material, Koken, Japan), or (c) no material implantation (negative control). The animals were then randomly scheduled for sacrifice at 1, 2, and 6 months, and samples were taken for histological examination. In the HA/agarose gels, the 2‐month postoperative cavities exhibited regeneration to new attachments with the apposition of a new cementum and well‐oriented fibers. The neocementum was narrow and acellular, and the new bone apposition was limited. Six months postoperatively, newly formed bone was predominantly observed. The neocementum was wider and cellular. In the negative control, the 2‐month postoperative cavities exhibited no regeneration of the cementum, nor any formation of periodontal pockets. The six‐month postoperative cavities were nearly the same as the 2‐month cavities. The Bone ject, 2‐month postoperative cavities exhibited no regeneration of the periodontal tissue, nor any formation of periodontal pockets. Six months postoperatively, inflammatory granulation tissue was observed around the particles. The present study suggests that HA/agarose gels may play an important role in the regeneration of lost periodontal tissue. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Recovery of carboxylic acids C1C3 with organophosphine oxide solvating extractants
Authors: Wisniewski Maciej , Pierzchalska Magdalena
Published: July 2005

This study was aimed at examining the use of the organophosphine oxides Cyanex®921 and Cyanex®923 for the extraction of formic, acetic and propionic acids from aqueous solutions. The stripping of monocarboxylic acids with water from the loaded extractants was also examined. The studies were aimed at determining the equilibrium conditions for extraction and stripping. Overall, the effect of the kind of extractant was not significant although Cyanex®921 extracted carboxylic acids slightly better than Cyanex®923 with 1:1 complexes being formed by both extractants with the acids during extraction. The efficiency of extraction depended on temperature, acid concentration and solvent, with toluene a better diluent for the extractants than octane or Exxsol®D 220/230. Extraction efficiency increased as the concentration of acid in the feed decreased and, also, as the temperature increased, the amount of acid extracted decreased. The extraction and stripping isotherms were determined. The apparent enthalpy and entropy of the extraction reaction were determined. Distribution data for the transfer of carboxylic acids from aqueous (NaCl) solutions to organic solvents in the presence of trialkylphosphine oxide were determined at 293 K with the distribution ratios increasing as the concentration of NaCl increased. Copyright © 2005 Society of Chemical Industry
Optimisation of a serine protease coupling to Eudragit S‐100 by experimental design techniques
Authors: Silva Carla JSM , Gübitz Georg , Cavaco‐Paulo Artur
Published: July 2005

A full factorial design was used to study the influence of four different variables, namely polymer concentration, carbodiimide concentration, time of reaction and blocking agent concentration, on the coupling of a serine protease into a soluble–insoluble polymer (Eudragit S‐100). All of the four factors studied have played a critical role in the protease coupling. Response surface methodology was used as an optimisation strategy to attain a conjugate with high activity yield and operational stability at 60 °C. Under optimised conditions (Eudragit, 2.5% w/v, carbodiimide, 0.2% w/v, coupling time, 1 h and blocking agent concentration, 0.05%), the conjugate activity yield was about 45% and its operational stability at 60 °C was increased by 1.7 times. After reusing the conjugate for five cycles, the remaining activity was still 72% of the initial value when compared with the native enzyme. Several tests confirmed that the enzyme was covalently crosslinked to Eudragit, which represents an improvement in the carbodiimide coupling of proteases into soluble–insoluble polymers. Copyright © 2005 Society of Chemical Industry
Chronic BDNF deficiency permanently modifies excitatory synapses in the piriform cortex
Authors: Nanobashvili Avtandil , Jakubs Katherine , Kokaia Merab
Published: July 2005

Brain‐derived neurotrophic factor (BDNF), aside from its classic neurotrophic role in development and survival of neurons, has been shown to be involved in modification and plasticity of central synapses. In mice with BDNF gene deletion (BDNF+/−), deficits in synaptic transmission are often observed but are reversed readily by administration of BDNF, suggesting its acute effect. In support, blockade of BDNF signaling in wild‐type hippocampal slices by TrkB‐IgG closely reproduces synaptic alterations observed in BDNF+/− mice. We demonstrate that in BDNF+/− mice, lateral olfactory tract (LOT) synapses exhibit decreased release probability of glutamate, suggested by increased paired‐pulse facilitation (PPF) of field excitatory postsynaptic potentials (fEPSPs), as well as by slower blocking rate of N‐methyl‐D‐aspartate (NMDA) receptor‐mediated excitatory postsynaptic currents (EPSCs) by MK‐801 in the pyramidal neurons of the piriform cortex. The changes in PPF were not mimicked in wild‐type mice by acute blockade of BDNF signaling by TkrB‐IgG. These data imply that BDNF deficit during development might lead to chronic changes of excitatory transmission in LOT synapses. Modification of the LOT synapses in BDNF+/− mice was associated with altered inhibitory drive onto the mitral cells from the granule and glomerular neurons, which in turn exhibited decreased renewal rate compared to that in wild‐type mice. Taken together, these data suggest that BDNF deficiency can have both acute and more permanent effects on synaptic function, particularly when BDNF signaling is compromised during the early stages of brain development. In the latter case, altered synaptic properties in BDNF+/− mice could be secondary to other complex changes in the brain, e.g., cell survival/proliferation. © 2005 Wiley‐Liss, Inc.
Role of Mayven, a kelch‐related protein in oligodendrocyte process formation
Authors: Williams Sarah K. , Spence Heather J. , Rodgers Ryan R. , Ozanne Bradford W. , FitzGerald Una , Barnett Susan C.
Published: July 2005

Oligodendrocyte function is central to the maintenance of the normal nervous system in health and disease. In particular, process formation and the generation of large sheets of myelin are important components of their biological properties. We have investigated the role of Mayven, a recently identified member of the kelch family of proteins, in process extension in oligodendrocyte‐lineage cells. The kelch superfamily consists of a large number of structurally diverse proteins characterized by the presence of a kelch‐repeat domain. Other members of this family associate with the actin cytoskeleton and regulate process length. Mayven is expressed predominantly in the CNS, has six kelch repeats, and is an actin‐binding protein, associating with actin through its kelch‐repeat domain. We have cloned rat Mayven and examined its role in the oligodendrocyte lineage by using RT‐PCR, RNA interference, and a truncated, dominant‐negative myc‐tagged Mayven. Oligodendrocyte precursors treated with siRNA directed to Mayven have reduced process length, but there was no change in migration or expression of differentiation markers. Immunocytochemistry demonstrated that Mayven associated with F‐actin at cell tips. Finally, overexpression of truncated Mayven lacking the SH3 ligand binding domain in oligodendrocyte‐lineage cells resulted in shorter process formation, which was augmented when the cells were plated on laminin and fibronectin. These data suggest a role for Mayven in oligodendrocyte precursor cell process formation. © 2005 Wiley‐Liss, Inc.
Functional mechanisms of apoptosis‐related proteins in neonatal rat cerebellum are differentially influenced by ethanol at postnatal days 4 and 7
Authors: Siler‐Marsiglio Kendra I. , Paiva Michael , Madorsky Irina , Pan Qun , Shaw Gerry , Heaton Marieta B.
Published: July 2005

Exposure of the developing nervous system to ethanol (EtOH) produces neurological aberrations associated with fetal alcohol syndrome. During a well‐defined period, cerebellar neurons are highly susceptible to EtOH‐induced death, primarily through apoptosis. Neonatal rodent cerebellum is exquisitely sensitive to EtOH on postnatal days 4–6 (P4–6); however, at slightly later developmental ages (P7 and later), EtOH effects are minimal. We have previously shown that EtOH differentially influences expression of apoptosis‐related proteins of the Bcl‐2 survival‐regulatory gene family in P4 and P7 cerebellum. In the present study, the effects of EtOH on multiple functional mechanisms of Bcl‐2, Bcl‐xL, and Bax were investigated to characterize further the processes underlying these disparate EtOH sensitivities. For these analyses, we addressed the following questions, by using P4 and P7 cerebellar tissue following in vivo exposure: 1) Are there differential patterns of expression of antiapoptotic Bcl‐2 or proapoptotic Bax in EtOH‐vulnerable Purkinje cells that could contribute to the different degrees of temporal EtOH vulnerability? 2) How does EtOH affect intracellular localization of apoptosis‐related proteins? 3) Does cleavage of Bax contribute to EtOH sensitivity? 4) Does EtOH differentially modulate cerebellar protein–protein interactions of Bcl‐2, Bcl‐xL, and Bax at the vulnerable vs. the resistant ages? Overall, we show that, at P4, the EtOH‐mediated effects on Bcl‐2, Bcl‐xL, and Bax favor a prodeath response, whereas most of the intracellular responses to EtOH exposure at P7 promote survival. Such differential responsiveness likely plays a major role in the disparate ethanol vulnerability at these two postnatal ages. © 2005 Wiley‐Liss, Inc.
Biliary epithelial cell antibodies induce expression of toll-like receptors 2 and 3: A mechanism for post–liver transplantation cholangitis?
Authors: Ge Xupeng , Uzunel Mehmet , Ericzon Bo-Göran , Sumitran-Holgersson Suchitra
Published: July 2005

Studies to determine the role of preformed antibodies to biliary epithelial cells (BECs) in liver transplant rejections have been initiated. However, the clinical importance of these antibodies in the posttransplantation period still remains to be elucidated. Reactivity to BECs isolated from a normal healthy liver was investigated in sera of 56 patients before and after liver transplantation (LTX) using flow cytometry. Functional capacity of BEC antibodies was determined by the ability to induce expression of Toll-like receptors (TLRs) on BECs. Cytokine and chemokine production induced by BEC antibodies was determined by enzyme-linked immunosorbent assay. In all, 7 patients (13%) had BEC antibodies only pre-LTX, 14 (25%) only after LTX, 18 (32%) both before and after LTX, and 17 (30%) had no detectable antibodies. Presence of preformed BEC antibodies correlated with acute rejections (

P

< 0.03). Deposition of immunoglobulins in bile ducts was detected in biopsies of patients during rejections. Significantly higher numbers of patients with post-LTX antibodies (9 of 32) developed cholangitis, compared with 0 of 17 without antibodies (

P

< 0.02). Specificity studies indicated that these antibodies were both non–HLA- and HLA-specific. Normal BECs expressed mRNA but not the proteins for the TLRs. However, treatment with F(ab′)2 fragments of BEC antibodies induced protein expression of TLRs 2 and 3 and significantly high production of interleukin (IL)-6, monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1α, epithelial neutrophil activating peptide (ENA)-78, and IL-8. In conclusion, BEC antibodies via induction of TLR2 and TLR3 expression, as well as inflammatory cytokine and chemokine production may induce epithelial cell inflammatory responses to bacterial components and contribute to posttransplantation cholangitis. (Liver Transpl 2005;11:911–921.)
Preoperative donor liver biopsy for adult living donor liver transplantation: Risks and benefits
Authors: Nadalin Silvio , Malagó Massimo , Valentin-Gamazo Camino , Testa Giuliano , Baba Hideo A. , Liu Chao , Frühauf Nils R. , Schaffer Randolph , Gerken Guido , Frilling Andrea , Broelsch Christoph E.
Published: July 2005

The role of liver biopsy (LB) in donor selection for adult living donor liver transplantation remains controversial, since the procedure is associated with additional potential risks for the donor. From April 1998 to August 2004, 730 potential living donors for 337 adult recipients underwent our multistep evaluation program. In 144 candidates, LB was performed. LB was obtained in a percutaneous ultrasound-guided fashion by means of Menghini needle (32 cases) or Tru-cut needle (112 cases). The biopsy specimen was preserved in 5% formalin and processed with hematoxylin & eosin–stained sections. Thirty-one (21%) of 144 candidates who underwent an LB had a positive finding at histological examination that induced their exclusion from donation, of whom 21 had liver steatosis of varying kind and grade (10%-80%) and 10 had a nonsteatotic hepatopathy (non–A-D hepatitis in 6 cases, diffuse granulomatosis in 2, schistosomiasis in 1, fibrosis in 1). The only observed major complications related to LB were 2 intraparenchymal haematomas, both of which resolved spontaneously within a few months. In conclusion, based on these findings, we believe that preoperative LB in the donor selection for adult LDLT is necessary, once the initial donor screening and noninvasive evaluation is complete. Because other screening modalities can be unreliable, without preoperative LB a fraction of potential donors will be operated on inappropriately, risking both donor and recipient. The main objective of LB should be to ensure the donor's safety more than the preservation of the graft function. (Liver Transpl 2005;11:980–986.)
Taurine improves graft survival after experimental liver transplantation
Authors: Schemmer Peter , Liang Rui , Kincius Marius , Flechtenmacher Christa , Bunzendahl Hartwig , Gutt Carsten N. , Mehrabi Arianeb , Gebhard Martha-Maria , Büchler Markus W. , Kraus Thomas W.
Published: July 2005

Relevant mechanisms of reperfusion injury after liver transplantation are most likely mediated by activated Kupffer cells. Recently, it has been demonstrated that taurine prevents Kupffer cell-activation in vitro. Thus, this study was designed to assess the effects of taurine after liver transplantation. Female Sprague-Dawley rats (210-240 g) were infused with taurine dissolved in normal saline, before organ harvest. Controls were infused with the same volume of normal saline without taurine. Following 4 hours of cold ischemia, liver transplantation was performed. Graft and animal survival, serum transaminases, liver histology, perfusion data of intravital microscopy, blood distribution at reperfusion, and both phagocytosis of Kupffer cells and expression of tumor necrosis factor α (TNF-α) to index cellular activation were investigated. For comparison, both, analysis of variance (ANOVA) and Fisher's exact test were used as appropriate. Results are presented as mean ± SEM. Controls survived in 60% of cases. Taurine improved survival in a dose-dependent manner to 100% (

P

< 0.05). In controls, mean aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactic dehydrogenase (LDH) serum levels increased to 3,260 ± 814; 1,703 ± 432; and 14,071 ± 3,177 U/L, respectively, after transplantation. In contrast, these values were between 20 and 45% of control values after taurine (

P

< 0.05). Histology taken after transplantation confirmed the significant protective effects of taurine, including the reduction of TNF-α expression. Time until homogeneous reperfusion of the graft improved to 50% of control values (

P

< 0.05). Further, taurine significantly decreased both phagocytosis of latex beads by Kupffer cells and leukocyte–endothelial cell interaction. In parallel, flow velocity of red blood cells as well as acinar and sinusoidal perfusion improved (

P

< 0.05). In conclusion, these data show for the first time in vivo that taurine minimizes reperfusion injury after liver transplantation. Decreased leukocyte–endothelial cell interaction and improved microcirculation are the proposed mechanisms, which are most likely Kupffer cell–dependent. (Liver Transpl 2005;11:950–959.)
Endovascular stent graft repair of abdominal aortic aneurysms after liver transplantation
Authors: Mekeel Kristin L. , Lee Anthony W. , Reed Alan I. , Hemming Alan W.
Published: July 2005

It is estimated that 1.7% of orthotopic liver transplant recipients will develop abdominal aortic aneurysms (AAAs) after transplantation. It has been observed that these aneurysms expand faster in transplant recipients; therefore, aggressive surveillance for AAAs in transplant recipients is required. Endovascular aneurysm repair is rapidly becoming the standard of care, especially in patients with previous abdominal surgery and other significant comorbidities. This article describes our experience with AAAs in orthotopic liver transplant recipients treated successfully by endovascular stent graft repair. (Liver Transpl 2005;11:993–997.)
Amorphous Polyethylene by Tandem Action of Cobalt and Titanium Single‐Site Catalysts
Authors: Bianchini Claudio , Frediani Marco , Giambastiani Giuliano , Kaminsky Walter , Meli Andrea , Passaglia Elisa
Published: July 2005

Summary: A variety of branched polyethylenes, spanning from semicrystalline LLDPE to completely amorphous, rubbery PE, was obtained from ethylene by homogeneous tandem catalysis using combinations of CoCl2(N) (1) (N = [1‐(6‐benzo[b]thiophen‐2‐yl‐pyridin‐2‐yl)‐ethylidlene)‐(2,6‐diisopropyl‐phenyl)‐amine) and [(η5‐C5Me4)SiMe2(tBuN)]TiCl2 (2) in the presence of MAO at 30 °C. The productivity reached a maximum of 4 570 kg PE (mol Ti · h)−1 at χCo = 0.50, yielding a rubbery material with d25 = 0.868 g · cm−3 and Tg = −55 °C.

Conversion of ethylene into branched polyethylene using CoII iminopyridyl complex CoCl2(N) (1) and TiCl2[(η5‐C5Me4)SiMe2(tBuN)] (2).

magnified image

Conversion of ethylene into branched polyethylene using CoII iminopyridyl complex CoCl2(N) (1) and TiCl2[(η5‐C5Me4)SiMe2(tBuN)] (2).
Wettability of Polyhedral Oligomeric Silsesquioxane Nanostructured Polymer Surfaces
Authors: Turri Stefano , Levi Marinella
Published: July 2005

Summary: Some model structures of waterborne polyurethane anionomers containing various amounts (ca. 3–20%) of a diol functionalized polyhedral oligomeric silsesquioxane (POSS) nanofiller were prepared. X‐ray diffraction showed the formation of a nanocrystalline structure in all copolymers considered. Static contact angle measurements indicated a significant enhancement of surface hydrophobicity as well as reduction in surface tension components even at the least POSS level (3%). Dynamic contact angle cycles allowed the evaluation of the hysteresis, which was found to be large and kinetically increasing in POSS‐modified samples. Film topography was analyzed by AFM, showing a more pronounced roughness in the nanostructured surface.

The AFM image showing a moderate roughness increase.

magnified image

The AFM image showing a moderate roughness increase.
Specific aspartate residues in FET3 control high‐affinity iron transport in Saccharomyces cerevisiae
Authors: Bonaccorsi di Patti Maria Carmela , Felice Maria Rosa , De Domenico Ivana , Lania Amalia , Alaleona Flaminia , Musci Giovanni
Published: July 2005

Site‐directed mutagenesis was performed on a set of six aspartate residues of Fet3, the multicopper ferroxidase involved in high‐affinity iron transport in Saccharomyces cerevisiae, in order to comprehend the molecular determinants of the protein function. Asp312, Asp315, Asp319 and Asp320 were predicted by homology modelling to be located in a negatively charged surface‐exposed loop of the protein. Other two aspartate residues (Asp278 and Asp279) are placed close to the type 1 copper‐ and iron‐binding sites, possibly linking these sites to the negatively charged region. In vivo results showed that mutation of Asp319 and Asp320 to yield D319N and D320N derivatives strongly impairs the ability of the yeast to grow under iron‐limiting conditions. In particular, substitution of Asp320 with asparagine essentially abolished the Fet3‐dependent iron transport activity. All other mutants (D278Q, D279N, D312N and D315I) behaved essentially as the wild‐type protein. The electron paramagnetic resonance spectrum of the soluble forms of D319N and D320N showed significant changes of the copper sites' geometry in D319N but not in D320N. At variance with the membrane‐bound forms, soluble D319N and D320N derivatives were highly susceptible to proteolytic degradation, suggesting that replacement of Asp319 or Asp320 locally modifies the structure of Fet3, making the protein sensitive to proteolysis when it is not protected by the membrane environment. In turn, this might be evidence of a shielding role of the permease Ftr1, which could interact with Fet3 at the level of the aspartate‐rich negatively charged region. Copyright © 2005 John Wiley & Sons, Ltd.
Importance of cell wall mannoproteins for septum formation in Saccharomyces cerevisiae
Authors: Schmidt Martin , Strenk Meghan E. , Boyer Michael P. , Fritsch Bryan J.
Published: July 2005

The mannosyltransferase mutants mnn9 and mnn10 were isolated in a genetic screen for septation defects in Saccharomyces cerevisiae. Ultrastructural examination of mutant cell walls revealed markedly thin septal structures and occasional failure to construct trilaminar septa, which then led to the formation of bulky default septa at the bud neck. In the absence of a functional septation apparatus, mnn10 mutants are unable to complete cytokinesis and die as cell chains with incompletely separated cytoplasms, indicating that mannosylation defects impair the ability to form remedial septa. We could not detect N‐linked glycosylation of the β(1,3)glucan synthase Fks1p and mnn10 defects do not change the molecular weight or abundance of the protein. We discuss a model explaining the pleiotropic effects of impaired N‐linked protein glycosylation on septation in S. cerevisiae. Copyright © 2005 John Wiley & Sons, Ltd.
Gelatin binding to the 8F19F1 module pair of human fibronectin requires site‐specific N‐glycosylation
Authors: Millard Christopher J. , Campbell Iain D. , Pickford Andrew R.
Published: July 2005

The gelatin (denatured collagen) binding domain of the extracellular matrix protein fibronectin contains three potential N‐glycosylation sites. Complete deglycosylation of this domain is known to reduce the thermal stability of the eighth type 1 (8F1) module. We have conducted a site‐specific analysis of the structural and functional consequences of N‐linked glycosylation in the 8F19F1 module pair. Three glycoforms have been identified by mass spectrometry and nuclear magnetic resonance spectroscopy. Chemical shift differences between the glycoforms have revealed an intimate interaction between one N‐linked sugar and the polypeptide that is critical for gelatin binding, as shown by affinity chromatography.
Met identification on human platelets: Role of hepatocyte growth factor in the modulation of platelet activation
Authors: Pietrapiana Daniela , Sala Marilena , Prat Maria , Sinigaglia Fabiola
Published: July 2005

Circulating HGF is significantly increased in a number of thrombus‐associated disorders. Since platelets play a pivotal role in thrombogenesis, the ability of HGF to interact with human platelets was investigated. This paper shows for the first time that human platelets express HGF receptor, the tyrosine kinase encoded by c‐MET gene. At physiological concentrations HGF was found to inhibit both glycoprotein αIIbβ3 activation and thrombin‐dependent platelet aggregation in a dose‐ and time‐dependent manner. These results suggest that circulating HGF may counteract thrombogenesis by negatively modulating platelet functions.
Theoretical model of the interactions between Ca2+, calmodulin and myosin light chain kinase
Authors: Fajmut Aleš , Brumen Milan , Schuster Stefan
Published: July 2005

Active Ca2+/calmodulin (CaM)‐dependent myosin light chain kinase (MLCK) plays an important role in the process of MLC phosphorylation and consecutive smooth muscle contraction. Here, we propose a mathematical model of a detailed kinetic scheme describing interactions among Ca2+, CaM and MLCK and taking into account eight different aggregates. The main model result is the prediction of the Ca2+ dependent active form of MLCK, which is in the model taken as proportional to the concentration of Ca4CaM · MLCK complex. Wegscheider's condition is additionally applied as a constraint enabling the prediction of some parameter values that have not yet been obtained by experiments.
A Rare Case of Grass Flow Induced by the M8.4 Arequipa Earthquake, June 2001, in the Altiplano of Northern Chile
Authors: Naranjo José A. , Clavero Jorge E.
Published: July 2005

On June 23, 2001, an M8.4 earthquake that originated in southern Peru triggered the partial collapse of the Chislluma bofedal (water meadows) in the Altiplano (high-altitude plateau) of northern Chile. The seismic waves evidently produced the liquefaction of the bofedal and caused its partial collapse generating a flow. The flow deposit was mainly made of long-fiber grass and water, with minor amounts of clastic material. It traveled more than 14 km downstream at a peak velocity of 50 km/h. It destroyed the water meadows and killed more than 20 llamas. Slurry flows caused by meadow liquefaction are a previously unrecognized seismic-induced geological hazard for high-altitude plateau areas such as the Altiplano.
Counting the Seven Weeks War: Dyads, Disputes and Balances of Power
Authors: Moul William
Published: July 2005

Abstract.The usual quantitative study of inter-state war and peace tallies observations on hundreds, sometimes thousands, of dyads or pairs of states. These observations miss elementary features of inter-state relations that should be examined when testing Realist explanations of war and peace. The way in which three prominent studies (Bremer, 1992; Bueno de Mesquita, 1981; 1985) chose to count the Seven Weeks War dramatically reveals the theoretical difficulties when tallying dyads. Re-analyses of these studies demonstrate the sensitivity of the results to particulars of 1866 Germany and, more importantly, illustrate the merits of analyzing the dispute rather than the state dyad or the state-dyad year.

Résumé.L'étude quantitative des périodes de guerre et de paix entre États comptabilise des observations relatives à des centaines, parfois des milliers de dyades ou paires d'États. Ces observations ne prennent pas en compte certaines caractéristiques élémentaires des relations entre États qui devraient pourtant être examinées lorsque l'on teste les théories réalistes expliquant guerre et paix. La manière dont trois études reconnues (Bremer, 1992; Bueno de Mesquita, 1981; 1985) ont choisi de comptabiliser la guerre des Sept Semaines révèle de manière éclatante les difficultés théoriques dans la comptabilisation des dyades d'états. De nouvelles analyses de ces études ont démontré la sensibilité des résultats aux caractéristiques de l'Allemagne de 1866, mais soulignent surtout les mérites de l'analyse des disputes par rapport à l'analyse des dyades d'États ou des dyades d'États annuelles.
From Kyoto to the WTO: Evaluating the Constitutional Legitimacy of the Provinces in Canadian Foreign Trade and Environmental Policy
Authors: Kukucha Christopher J.
Published: July 2005

Abstract.The Kyoto Protocol was a controversial issue within Canadian federalism, especially in Alberta, where the province considered a formal constitutional challenge regarding the implementation of the agreement. This option was not pursued, however, due to existing judicial precedent that limits the jurisdictional authority of the provinces in international affairs. Regardless, these rulings still suggest a level of constitutional ambiguity, which creates motivation for federal-provincial cooperation on foreign trade and environmental policy. As a result, highly valued formalized consultative mechanisms have developed in these issue areas during the past two decades. Ottawa's decision to ratify Kyoto, however, represented a significant departure from previous practices of cooperative federalism. In pursuing the protocol as part of his legacy agenda, Chrétien was aware of the provinces' tenuous constitutional status. It is important to note, however, that the resulting tension between both levels of government was atypical and does not threaten the viability of cooperative federalism in the near future.

Résumé.Le protocole de Kyoto a suscité de nombreuses controverses au sein du fédéralisme canadien, en particulier en Alberta où le gouvernement songea même à contester formellement la constitutionnalité de sa mise en oeuvre. En définitive, il a abandonné cette option en raison de précédents jurisprudentiels qui limitent la juridiction des provinces en affaires internationales. Ces décisions suggèrent néanmoins qu'il existe un certain niveau d'ambiguïté constitutionnelle propre à motiver une attitude de coopération fédérale-provinciale en matière d'environnement et de commerce extérieur. De ce fait, des mécanismes consultatifs très structurés ont été mis au point dans ces domaines au cours des deux dernières décennies. Or, la décision d'Ottawa de ratifier Kyoto contrastait nettement avec les pratiques antérieures de fédéralisme coopératif. En cherchant à faire du Protocole de Kyoto un élément de son héritage, Chrétien était conscient de la fragilité des arguments constitutionnels des provinces. Cependant, il est important de noter que la tension ainsi créée entre les deux niveaux de gouvernement était atypique et qu'elle ne menace pas la validité du fédéralisme coopératif dans l'avenir.
Bureaucrats and Revolutionary State-Building in Ireland and Russia. Was Weber Right?
Authors: Velychenko Stephen
Published: July 2005

Abstract.Weber argued that bureaucrats serve whoever holds power even in the case of revolution or enemy occupation because they are more concerned with their jobs, salaries and pensions than with political ideas. His hypothesis has yet to be satisfactorily tested, however, and any such project would have to include all states that emerged from revolutions. As a contribution towards such an examination this paper reviews state building in nationalist Ireland and Bolshevik Russia to determine whether the behaviour of old-regime administrators in those countries proves or disproves Weber's claim.

Résumé.Weber avançait que les bureaucrates servent quiconque est au pouvoir, même en cas de révolution ou d'occupation ennemie, parce qu'ils se soucient davantage de leurs emplois, de leurs salaires et de leurs pensions que d'idées politiques. Son hypothèse n'a cependant jamais été testée de manière satisfaisante et tout projet de ce genre devrait nécessairement inclure tous les États qui sont issus de révolutions. En guise de contribution à un tel examen, cet article examine la création de l'État dans l'Irlande nationaliste et la Russie bolchévique pour déterminer si le comportement des fonctionnaires de l'ancien régime de ces pays confirme ou réfute l'allégation de Weber.
Breaking the Bargain: Public Servants, Ministers and
Parliament
Authors: Carroll Barbara Wake
Published: July 2005

Breaking the Bargain: Public Servants, Ministers and Parliament,
Donald J. Savoie, Toronto: University of Toronto Press, 2003, pp. xiv,
337

Most of us have been taught, and have taught, about the traditional
relationship between public servants, ministers and parliaments under the
Westminster tradition of government. Ideas like the accountability of the
neutral, non-partisan, anonymous senior public servant to his minister,
and concepts like ministerial responsibility and collective cabinet
responsibility to Parliament, and the oversight and legislative role of
Parliament, are part of what Donald Savoie calls the traditional bargain
that underpins the political and administrative process in Canada. The
central thesis of this book is that this traditional bargain has been
broken and a new bargain needs to be struck if our system of responsible
government is going to continue to function effectively.
Démocraties métropolitaines
Authors: Marsollier Elisabeth
Published: July 2005

Démocraties métropolitaines, Bernard Jouve et Philip
Booth (sous la direction de), Sainte-Foy, Québec : Presses de
l'Université du Québec, 2004, 335 p.

Cet ouvrage collectif traite de gouvernance des métropoles, de
politiques urbaines et de démocratie métropolitaine en
France, en Grande-Bretagne et au Canada. Sa parution survient au moment
où la province de Québec entend développer des
partenariats publics privés, s'inspirant largement des
exemples britanniques, afin de résoudre les problèmes de
rénovation des infrastructures majeures des grandes
métropoles du Québec. Il s'adresse aux
géographes, aux urbanistes, aux économistes, aux
politologues et aux sociologues curieux des multiples facettes du fait
urbain, de la croissance et du développement des métropoles
et de leurs habitants, ainsi que de l'évolution de la
compréhension du concept de gestion démocratique du
développement en Europe et en Amérique du Nord.
L'Allemagne en guerre.
Authors: Laberge Yves
Published: July 2005

L'Allemagne en guerre., Forty, George et Johanne King.,
St-Sulpice (Suisse) : Éditions Labodega, 2003, 256 p.

Aujourd'hui à la retraite, le lieutenant-colonel George
Forty a publié une quarantaine de livres sur l'histoire
militaire du 20e siècle, principalement en Angleterre,
parallèlement à une seconde carrière de conservateur,
en tant que directeur du musée militaire de Bovington (au
Royaume-Uni). Le présent ouvrage, le seul disponible en
français, est la traduction de Germany at War,
initialement paru chez Carlton Books en 2003. Cet ouvrage abondamment
illustré livre de nouvelles archives sur la Deuxième guerre
mondiale et constitue une introduction générale utile pour
s'initier à cette période, en décrivant la vie
quotidienne durant les années 1930 et jusqu'à
l'arrivée des Alliés. La documentation réunie
provient de sources variées et fournit surtout le point de vue nazi
vu de l'intérieur, c'est-à-dire à partir de
témoignages et d'illustrations ayant appartenu principalement
à des particuliers allemands.
Reigns of Terror
Authors: Wheeler Ron
Published: July 2005

Reigns of Terror, Patricia Marchak, Montreal: McGill-Queen's
University Press, 2003, pp. xi, 306

In Reigns of Terror, Patricia Marchak investigates “the
causes and conditions that underlie crimes against humanity conducted
under the aegis of states” (x). According to Marchak, most works on
genocide (attacks on citizens because of their ethnicity or religion) and
politicide (the eradication of people for mainly political reasons) are
far too simplistic. She maintains that factors such as racism, ethnic
conflict, authoritarian regimes or ideologies of intolerance and hatred
are usually important, but each is nonetheless insufficient in explaining
situations in the twentieth century in which governments attacked their
own citizens.
The Decline of Politics: Governance, Globalization and the Public
Sphere
Authors: Migone Andrea
Published: July 2005

The Decline of Politics: Governance, Globalization and the Public
Sphere, Peter Marden, Aldershot: Ashgate, 2003, pp. xvi, 286

Here is a book that takes readers above and beyond the usual
one-dimensional approach to globalization, all too often couched in
economics, with which we have become familiar of late. Marden's
Decline of Politics will reward those readers who are looking for
a multifaceted analysis of global trends, and will intrigue and challenge
those who believe that they already understand them.
Demography of red clover seeds in mixed-sown meadows
Authors: SAKANOUE S.
Published: July 2005

To clarify the reproduction probability of red clover (Trifolium pratense L.) in meadows for herbage cutting, the demography of this legume was studied in a meadow in the central mountainous district of Japan. The present study shows the demography of deposited red clover seeds in a meadow, where timothy (Phleum pratense L.) predominated and herbage had been harvested for making hay or silage in early June and late August of a year. The densities of deposited seeds, buried seeds and seedlings were monitored to determine their survival. Deposited seeds were collected using seed traps, buried seeds were monitored seasonally by sampling them from topsoil and seedlings were counted in ten permanent 1×1 m quadrats. Many permeable and hard seeds of red clover were deposited on the soil surface of the meadow during the mechanical operation of the second haymaking in mid- to late August. Of the population of deposited permeable seeds, 0·16 germinated and 0·84 were lost in the present autumn. Conversely, of the population of deposited hard seeds, 0·11 germinated in the succeeding spring, 0·83 were lost and 0·06 remained as hard seeds until the succeeding autumn. The deposited permeable and hard seeds could contribute to the persistence of red clover population when their seedlings survived for seed setting in the meadow.
Characterization of growth traits of Greenland and Silver coypus under captivity conditions
Authors: FAVERIN C. , MEZZADRA C. A. , FERNÁNDEZ H. M. , MELUCCI L. M.
Published: July 2005

Brody, Gompertz, Logistic, Richards and von Bertalanffy functions were compared as descriptors of growth in 319 coypus (Myocastor coypus) of Greenland and Silver varieties, from birth to 10–19 months of age. Several criteria were considered for the selection of the model: (a) bias in the asymptotic weight; (b) bias in birth weight; (c) error sum of squares; (d) error mean squares weighted by the number of animals converging in all functions; (e) determination coefficient. To adjust the curves NLIN procedure from SAS and iterative method of Marquardt were applied. A mixed model was used to analyse the parameters of the selected growth curve (asymptotic weight, A; constant of integration, B; and maturation rate, k) which included effects of farm, variety, sex, sire within farm and variety, reproductive status within sex, birth season and first order interactions. The effect of sire was considered as random. The von Bertalanffy function was selected and mean values for the parameters of this function were 8016 g and 0·008 g/g per day, for A and k respectively. There were differences in the estimated parameters between sexes; males had larger values of A and k than females.

Weights at fixed ages (birth, weaning, 6–7 months) were analysed, as well as the final recorded weight and average postweaning gain. The model of analysis was similar to the previous one. There were no differences between varieties. Significant differences between sexes for almost all studied traits were detected. With age, weight difference between males and females increased. At 6 months of age, males were 37% heavier than females. Male average daily gain was higher than that of females, sexual dimorphism being evident in all analysed traits.
Where is the classic interference theory for sleep and memory?
Authors: Coenen Anton
Published: July 2005

Walker's target article proposes a refinement of the well known two-stage model of memory formation to explain the positive effects of sleep on consolidation. After a first stage in which a labile memory representation is formed, a further stabilisation of the memory trace takes place in the second stage, which is dependent on (REM) sleep. Walker has refined the latter stage into a stage in which a consolidation-based enhancement occurs. It is not completely clear what consolidation-based enhancement implies and how it can be dissociated from a stage for memory-stabilisation. A more serious consideration, however, is whether a second stage in memory consolidation that is solely dependent on sleep, is really necessary. The classical, passive, interference theory is able to explain adequately the findings related to the effects of sleep and memory, and can lead perhaps better to an understanding of the highly variable data in this field.
“Commitment” distinguishes between rules and similarity: A developmental perspective
Authors: Diesendruck Gil
Published: July 2005

A qualitative difference between Rules and Similarity in categorization can be described in terms of “commitment”: Rules entail it, Similarity does not. Commitment derives from people's knowledge of a domain, and it is what justifies people's inferences, selective attention, and dismissal of irrelevant information. Studies show that when children have knowledge, they manifest these aspects of commitment, thus overcoming Similarity.