bluuebunny/crossref_metadata_2025 huggingface dataset:
Sol gel derived SiO2‐CaO‐MgO‐P2O5 bioglass system—Preparation and in vitro characterization
Authors: Balamurugan A. , Balossier G. , Michel J. , Kannan S. , Benhayoune H. , Rebelo A. H. S. , Ferreira J. M. F.
Published: April 2007

The synthesis of SiO2‐CaO‐MgO‐P2O5 bioactive glass was carried out by the sol‐gel method. Sol‐gel derived bioglass material was crushed into powder to produce pellet disks by uniaxial pressing, followed by sintering at 900°C. The biocompatibility evaluation of the formed glass was assessed through in vitro cell culture experiments and immersion studies in simulated body fluid (SBF) for different time intervals while monitoring the pH changes and the concentration of calcium and magnesium in the SBF medium. Scanning electron microscopy, X‐ray energy dispersive spectroscopy, X‐ray diffraction analysis, and FT‐IR spectroscopy studies were conducted before and after contact of the material with SBF. At first, an amorphous calcium phosphate was formed; after 21 days this surface consisted of deposited crystalline spheres of apatite. The present investigation also revealed that the sol‐gel derived quaternary bioglass system has the ability to support the growth of osteoblast‐like cells in vitro and to promote osteoblast differentiation by stimulating the expression of major phenotypic markers. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2007
Growth of osteoblast‐like cells on biomimetic apatite‐coated chitosan scaffolds
Authors: Manjubala I. , Ponomarev Igor , Wilke Ingo , Jandt Klaus D.
Published: April 2007

Porous scaffold materials that can provide a framework for the cells to adhere, proliferate, and create extracellular matrix are considered to be suitable materials for bone regeneration. Interconnected porous chitosan scaffolds were prepared by freeze‐drying method, and were mineralized by calcium and phosphate solution by double‐diffusion method to form nanoapatite in chitosan matrix. The mineralized chitosan scaffold contains hydroxyapatite nanocrystals on the surface and also within the pore channels of the scaffold. To assess the effect of apatite and porosity of the scaffolds on cells, human osteoblast (SaOS‐2) cells were cultured on unmineralized and mineralized chitosan scaffolds. The cell growth on the mineralized scaffolds and on the pure chitosan scaffold shows a similar growth trend. The total protein content and alkaline phosphatase enzyme activity of the cells grown on scaffolds were quantified, and were found to increase over time in mineralized scaffold after 1 and 3 weeks of culture. The electron microscopy of the cell‐seeded scaffolds showed that most of the outer macropores became sealed off by a continuous layer of cells. The cells spanned around the pore wall and formed extra cellular matrix, consisting mainly of collagen in mineralized scaffolds. The hydroxyproline content also confirmed the formation of the collagen matrix by cells in mineralized scaffolds. This study demonstrated that the presence of apatite nanocrystals in chitosan scaffolds does not significantly influence the growth of cells, but does induce the formation of extracellular matrix and therefore has the potential to serve for bone tissue engineering. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Evaluation of novel injectable hydrogels for nucleus pulposus replacement
Authors: Vernengo J. , Fussell G. W. , Smith N. G. , Lowman A. M.
Published: April 2007

Branched copolymers composed of poly(N‐isopropylacrylamide) (PNIPAAm) and poly(ethylene glycol) (PEG) are being investigated as anin situforming replacement for the nucleus pulposus of the intervertebral disc. A family of copolymers was synthesized by varying the molecular weight of the PEG blocks and molar ratio of NIPAAm monomer units to PEG branches. Gel swelling, dissolution, and compressive mechanical properties were characterized over 90 days and stress relaxation behavior over 30 days immersionin vitro. It was found that the NIPAAm to PEG molar ratio did not affect the equilibrium swelling and compressive mechanical properties. However, gel elasticity exhibited a dependency on both the PEG block molecular weight and content. The equilibrium gel water content increased and compressive modulus decreased with increasing PEG block size. While all of the branched copolymers showed significant increases in stress relaxation time constant compared to the homopolymer (p< 0.05), the high PEG content PNIPAAm‐PEG (4600 and 8000 g/mol) exhibited the maximum elasticity. Because of its high water content, requisite stiffness and high elastic response, PNIPAAm‐PEG (4600 g/mol) will be further evaluated as a candidate material for nucleus pulposus replacement. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2008
Mechanical basis for bone retention around dental implants
Authors: Alexander Harold , Ricci John L. , Hrico George J.
Published: April 2007

This study, analytically, through finite element analysis, predicts the minimization of crestal bone stress resulting from implant collar surface treatment. A tapered dental implant design with (LL) and without (control, C) laser microgrooving surface treatment are evaluated. The LL implant has the same tapered body design and thread surface treatment as the C implant, but has a 2‐mm wide collar that has been laser micromachined with 8 and 12 μm grooves in the lower 1.5 mm to enhance tissue attachment. In vivo animal and human studies previously demonstrated decreased crestal bone loss with the LL implant. Axial and side loading with two different collar/bone interfaces (nonbonded and bonded, to simulate the C and LL surfaces, respectively) are considered. For 80 N side load, the maximum crestal bone distortional stress around C is 91.9 MPa, while the maximum crestal bone stress around LL, 22.6 MPa, is significantly lower. Finite element analysis suggests that stress overload may be responsible for the loss of crestal bone. Attaching bone to the collar with LL is predicted to diminish this effect, benefiting crestal bone retention. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Surface patterning: Tool to modulate stem cell differentiation in an adipose system
Authors: Chaubey Aditya , Ross Kevin J. , Leadbetter Ross M. , Burg Karen J. L.
Published: April 2007

There are several issues that need to be better understood before breast tissue‐engineering becomes viable clinically. One of the key issues is the interaction between cells and the microtopography of the implant surface. The aim of this study was to evaluate the efficacy of D1 cells, multipotent mouse bone marrow stromal precursors, in differentiating to fat and to characterize their metabolic activity (lactic acid released and glucose consumed) and lipid production when cultured on patterned poly‐L‐lactide (PLLA) films. It was determined that, with appropriate stimulation, the D1 cells displayed morphological characteristics of adipocytes and produced lipid. The results show that the patterned surfaces did affect the rate of lipid production. Polynomial models were proposed to predict the metabolic activity of the cells over a period of time. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Fabrication of novel calcium phosphate/poly(lactic acid) fiber composites
Authors: Kothapalli Chandrasekhar R. , Shaw Montgomery T. , Olson James R. , Wei Mei
Published: April 2007

Composites using high‐modulus polylactic acid (PLA) fibers coated with calcium phosphate (CaP) were prepared using a cyclic precipitation technique. Scanning electron microscopy revealed that small nuclei of CaP formed after the first soaking cycle, while large quantities of CaP particles were observed after the sixth cycle. The amount of CaP deposited on the PLA yarn increased with deposition time in Ca2+ and PO solutions and number of cycles, and decreased with stirring rate during washing cycles. It was observed that around 35 wt % of CaP was deposited on the yarn surface after six cycles of cyclic‐soaking. Based on the results, a heterogeneous nucleation and growth mechanism was proposed for the CaP deposition on the surface of hydrolyzed polyester. Composites comprising the coated fibers in a poly(caprolactone) matrix exhibited flexural moduli within the range of that of the cortical bone. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
The effect of roughness on the tribological behavior of the prosthetic pair UHMWPE/TiN‐coated stainless steel
Authors: Gispert M. P. , Serro A. P. , Colaço R. , Pires E. , Saramago B.
Published: April 2007

The effect of roughness on the tribological behavior of the prosthetic pair ultra high molecular weight polyethylene (UHMWPE)/TiN coated stainless steel was investigated. Standard and polished TiN coated stainless steel pins were tested against either standard or smooth UHMWPE disks. Hanks' Balanced Salt Solution (HBSS) and bovine serum albumin (BSA) solution in HBSS were used as lubricants. Friction and wear were determined using a pin‐on‐disk apparatus and the wear mechanisms were investigated through optical microscopy, scanning electron microscopy, and atomic force microscopy. The results showed that the decrease in the roughness led to a reduction of the friction coefficient and of the wear rate of UHMWPE. However, the most important effect was achieved through the decrease in the roughness of the hard TiN counterface while keeping the standard UHMWPE surface. If BSA was added to HBSS, a strong decrease of both the friction coefficient and the polymeric wear was observed independently of the roughness of both the TiN and the polyethylene surfaces. Abrasive and fatigue wear mechanisms are proposed to interpret the experimental results. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2008
Effect of water storage time and composite cement thickness on fatigue of a glass‐ceramic trilayer system
Authors: Silva Nelson R. F. A. , de Souza Grace M. , Coelho Paulo G. , Stappert Christian F. J. , Clark Elizabeth A. , Rekow Elizabeth D. , Thompson Van P.
Published: April 2007

Aim. Static Hertzian contact tests of monolayer glass‐ceramics in trilayer configurations (glass‐ceramic/cement/composite) have shown that thick cement layers lower strength. This study sought to test the hypothesis that thick resin cement layers lower mouth motion fatigue reliability for flat glass‐ceramic/cement/composite trilayer systems and that aging in water reduces reliability. Methods. Dicor plates (n ≥ 12 per group) (10 × 10 × 0.8 mm3) were aluminum‐oxide abraded (50 μm), etched (60 s), silanized, and bonded (Rely X ARC) to water aged (30 days) Z100 resin blocks (10 × 10 × 4 mm3). Four groups were prepared: (1) thick cement layer (>100 μm) stored in water for 24–48 h, (2) thick cement layer stored for 60 days, (3) thin cement layer (≤100 μm) stored for 24–48 h, and (4) thin cement layer stored for 60 days. The layered structures were fatigued (2 Hz) utilizing mouth motion loading with a step‐stress acceleration method. A master Weibull distribution was calculated and reliability determined (with 90% confidence intervals) at a given number of cycles and load. Results. The aged group (60 d) with thick cement layer had statistically lower reliability for 20,000 cycles at 150 N peak load (0.11) compared with both nonaged groups (24–48 h) (thin layer = 0.90 and thick layer = 0.82) and aged group with thin cement layer (0.89). Conclusion. Trilayer specimens with thick cement layers exhibited significantly lower reliability under fatigue testing only when stored for 60 days in water. The hypothesis was accepted. These results suggest that diffusion of water into the resin cement and also to the glass‐ceramic interface is delayed in the thick cement specimens at 24–48 h. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2008
Thermoreversible gel–sol behavior of biodegradable PCL‐PEG‐PCL triblock copolymer in aqueous solutions
Authors: Liu Cai Bing , Gong Chang Yang , Huang Mei Juan , Wang Ji Wei , Pan Yi Feng , Zhang Yang De , Li Guo Zheng , Gou Ma Ling , Wang Ke , Tu Ming Jing , Wei Yu Quan , Qian Zhi Yong
Published: April 2007

A series of biodegradable PCL‐PEG‐PCL block copolymers were successfully synthesized by ring‐opening polymerization of ε‐caprolactone initiated by poly(ethylene glycol) (PEG), which were characterized by 1H NMR, 13C NMR, and FTIR. Their aqueous solution displayed special gel–sol transition behavior with temperature increasing from 4 to 100°C, when the polymer concentration was above corresponding critical gel concentration (CGC). The gel–sol phase diagram was recorded using test tube inverting method and DSC method, which depended not only on chemical composition of copolymers, but also on heating history of copolymer's aqueous solution. As a result, the gel–sol transition temperature could be adjusted, which might be very useful for its application in biomedical fields such as injectable drug delivery system. And the typical shell‐core structure of PCL‐PEG‐PCL micelles was introduced. The micelle‐packing and partial crystallization might be the key gelation machanism for this gel–sol transition behavior of PCL‐PEG‐PCL aqueous solution. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 84B: 165–175, 2008
The essentiality of PKCα and PKCβI translocation for CD14+monocyte differentiation towards macrophages and dendritic cells, respectively
Authors: Lin Yuan‐Feng , Lee Horng‐Mo , Leu Sy‐Jye , Tsai Yu‐Hui
Published: April 2007

Human peripheral CD14+monocytes have been known to differentiate into monocyte‐derived macrophages (MDMs) or dendritic cells (MoDCs) upon suitable stimulation. However, the key intracellular molecule(s) associated with their differentiation towards specific cell types was(were) not fully understood. This study was designated to determine the association of PKC isoenzymes with the differentiation of CD14+monocytes into MDMs or MoDCs. Purified human peripheral CD14+monocytes were cultured with GM‐CSF, or GM‐CSF plus IL‐4 for 7 days to induce cell differentiation. The phenotypic changes were analyzed by Flow‐Cytometry using various specific antibodies to cell type‐specific surface markers. The immunological functions of these differentiated cells were determined by measuring the amounts of TNF‐α secretion for MDMs, and the capacities of antigen‐capturing and bacterial phagocytosis for MoDCs. The translocations of PKC isoenzymes in these cells from cytosol to plasma membrane were examined by Western Blot analysis and Confocal Microscopic observation. The treatment of CD14+monocytes with either GM‐CSF or PMA elicited PKCα translocation and consequently induced their differentiation into MDMs. The inclusion of PKCα/βI specific inhibitor, Go6976, greatly inhibited the GM‐CSF‐induced PKCα translocation and dose‐dependently reduced the GM‐CSF‐ induced MDM differentiation. On the other hand, the simultaneous pretreatment of CD14+monocytes with Go6976 and PKCβ‐specific inhibitor predominantly suppressed the GM‐CSF/IL‐4‐induced generation of MoDCs. Further study demonstrated that GM‐CSF/IL‐4 selectively induced the translocation of PKCβI, not PKCα or PKCβII, in CD14+monocytes. In conclusion, the cell fate commitment of CD14+monocytes towards MDMs or MoDCs appears to be steered by the selective activation of PKCα or PKCβI, respectively. J. Cell. Biochem. 102: 429–441, 2007. © 2007 Wiley‐Liss, Inc.
The molecular mechanisms of vitamin C on cell cycle regulation in B16F10 murine melanoma
Authors: Hahm Eunsil , Jin Dong‐Hoon , Kang Jae Seung , Kim Young‐In , Hong Seung‐Woo , Lee Seung Koo , Kim Ha Na , Jung Da Jung , Kim Jee Eun , Shin Dong Hoon , Hwang Young Il , Kim Yeong Seok , Hur Dae Young , Yang Yoolhee , Cho Daeho , Lee Myeong‐Sok , Lee Wang Jae
Published: April 2007

Vitamin C has inconsistent effects on malignant tumor cells, which vary from growth stimulation to apoptosis induction. It is well known that melanoma cells are more susceptible to vitamin C than any other tumor cells, but the precise mechanism remains to be elucidated. In the present study, the proliferation of B16F10 melanoma cells was suppressed by vitamin C, which induced growth arrest in a dose‐dependent manner without cytotoxic effects. Therefore, we investigated the changes in cell cycle distribution of B16F10 melanoma cells by staining DNAs with propidium iodide (PI). The growth inhibition of B16F10 melanoma by vitamin C was associated with an arrest of cell cycle distribution at G1 stage. In addition, the levels of p53‐p21Waf1/Cip1 increased during G1 arrest, which were essential for vitamin C‐induced cell cycle arrest. The increased p21Waf1/Cip1 inhibited CDK2. Moreover, the activity of p53‐p21Waf1/Cip1 pathway was closely related with the activation of checkpoint kinase 2 (Chk2). Inhibitor of the PI3K‐family, LY294002 and the ATM/ATR inhibitor, caffeine, blocked vitamin C‐induced growth arrest in B16F10 melanoma cells. These results suggest that vitamin C might be a potent agent to inhibit proliferative activity of melanoma cells via the regulation of Chk2‐p53‐p21Waf1/Cip1 pathway. J. Cell. Biochem. 102: 1002–1010, 2007. © 2007 Wiley‐Liss, Inc.
Protein kinase Cδ‐mediated CREB activation regulates ghrelin‐induced cyclooxygenase‐2 expression and prostaglandin E2 production in human colonic epithelial cells
Authors: Zhao Dezheng
Published: April 2007

Ghrelin, a newly identified gastric peptide, is known for its potent activity in growth hormone release and appetite. Our recent study showed that ghrelin could stimulate protein kinase C‐mediated activation of nuclear factor‐κB (NF‐κB) and interleukin‐8 secretion in human colonic epithelial cells transfected with a functional ghrelin receptor. In the present study, the effect of ghrelin stimulation on cyclooxygenese‐2 expression and prostaglandin E2 production was examined. The data indicate that ghrelin significantly increased the levels of cyclooxygenase‐2 (COX‐2) protein as well as its promoter activity, which leaded to profound increase in prostaglandin E2 secretion. In order to examine the involvement of NF‐κB and cAMP responsive element‐binding protein (CREB) in this response, the NF‐κB inhibitory protein IκBα or a dominant negative mutant of CREB was co‐transfected into cells and the data show that transfection of either IκBα or DN‐CREB significantly attenuated ghrelin‐induced COX‐2 expression. Moreover ghrelin stimulated phosphorylation of CREB, which was mediated primarily via protein kinase Cδ activation. Furthermore, inhibition of PKCδ function significantly attenuated ghrelin‐induced COX‐2 expression. In addition, ghrelin stimulates phosphorylation of PKCδ. Together, these results indicate that in addition to NF‐κB, protein kinase Cδ‐mediated CREB activation plays an important role in the cellular responses of ghrelin. J. Cell. Biochem. 102: 1245–1255, 2007. © 2007 Wiley‐Liss, Inc.
Electron affinities of heavier phosphoryl and thiophosphoryl halides APX3 (A = O, S and X = Br, I)
Authors: Zeng T. , Jamshidi Z. , Mori H. , Miyoshi E. , Klobukowski M.
Published: April 2007

We carried out computational studies of OPX3 and SPX3 (X = Br and I) molecules and their corresponding anions using density functional theory, Møller‐Plesset, and CCSD(T) methods with newly developed model core potentials (MCP). Reliabilities of the MCP were demonstrated by comparing experimental and calculated results. We computed the geometric structure, electron affinities, and electrostatic moments using systematic sequences of the dzp‐, tzp‐, and qzp‐quality basis sets. Both C3v and Cs symmetries were assumed to ascertain that minima on the potential energy surface were found. Infrared and Raman frequencies were calculated and compared with available experimental data. Natural population analyses were performed and used to determine distribution of the extra electron in anions. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
CaMKII can participate in but is not sufficient for the establishment of the membrane block to polyspermy in mouse eggs
Authors: Gardner Allison J. , Knott Jason G. , Jones Keith T. , Evans Janice P.
Published: April 2007

Fertilization triggers initiation of development and establishment of blocks on the egg coat and plasma membrane to prevent fertilization by multiple sperm (polyspermy). The mechanism(s) by which mammalian eggs establish the membrane block to polyspermy is largely unknown. Ca2+/calmodulin‐dependent protein kinase II (CaMKII) appears to be the key regulator of several egg activation events (completion of meiosis, progression to embryonic interphase, recruitment of maternal mRNAs). Since sperm‐induced increases in cytosolic Ca2+ play a role in establishment of the membrane block to polyspermy in mouse eggs, we hypothesized that CaMKII was a Ca2+‐dependent effector leading to this change in egg membrane function. To test this hypothesis, we modulated CaMKII activity in two ways: activating eggs parthenogenetically by introducing constitutively active CaMKIIα (CA‐CaMKII) into unfertilized eggs, and inhibiting endogenous CaMKII in fertilized eggs with myristoylated autocamtide 2‐related inhibitory peptide (myrAIP). We find that eggs treated with myrAIP establish a less effective membrane block to polyspermy than do control eggs, but that CA‐CaMKII is not sufficient for membrane block establishment, despite the fact that CA‐CaMKII‐activated eggs undergo other egg activation events. This suggests that: (1) CaMKII activity contributes to the membrane block, but this not faithfully mimicked by CA‐CaMKII and furthermore, other pathways, in addition to those activated by Ca2+ and CaMKII, also participate in membrane block establishment; (2) CA‐CaMKII has a range of effects as a parthenogenetic trigger of egg activation (high levels of cell cycle resumption, modest levels of cortical granule exocytosis, and no membrane block establishment). J. Cell. Physiol. 212: 275–280, 2007. © 2007 Wiley‐Liss, Inc.
A novel approach to extract accurate design parameters of PiN diode
Authors: Ben Salah Tarek , Ghédira Sami , Garrab Hatem , Morel Hervé , Riseletto Damien , Besbes Kamel
Published: April 2007

Accurate modelling of PiN diode transient behaviour is necessary to extract design parameters which are not documented in datasheets. To meet this requirement, this paper introduces a novel approach giving the possibility to identify accurate parameters of a given device. The used technique is based only on two stages. First, the design parameters are initialized and optimized. Second, they are refined by minimizing the cost function which depends on the transient switching parameters (IRM,VRMandtrr).

With a simple and CPU time‐saving approach this technique leads to extract design parameters without necessarily knowing the exact technological architecture of the PiN diode. Moreover, in order to validate the proposed approach and the parameter extraction procedure three commercial diodes are tested. A good agreement between experimental and simulation data is obtained. Copyright © 2007 John Wiley & Sons, Ltd.
The synapsin cycle: A view from the synaptic endocytic zone
Authors: Evergren E. , Benfenati F. , Shupliakov O.
Published: April 2007

Although the synapsin phosphoproteins were discovered more than 30 years ago and are known to play important roles in neurotransmitter release and synaptogenesis, a complete picture of their functions within the nerve terminal is lacking. It has been shown that these proteins play an important role in the clustering of synaptic vesicles (SVs) at active zones and function as modulators of synaptic strength by acting at both pre‐ and postdocking levels. Recent studies have demonstrated that synapsins migrate to the endocytic zone of central synapses during neurotransmitter release, which suggests that there are additional functions for these proteins in SV recycling. © 2007 Wiley‐Liss, Inc.
Effects of motor and sensory nerve transplants on amount and specificity of sciatic nerve regeneration
Authors: Lago Natalia , Rodríguez Francisco J. , Guzmán Mónica S. , Jaramillo Jéssica , Navarro Xavier
Published: April 2007

Nerve regeneration after complete transection does not allow for adequate functional recovery mainly because of lack of selectivity of target reinnervation. We assessed if transplanting a nerve segment from either motor or sensory origin may improve specifically the accuracy of sensory and motor reinnervation. For this purpose, the rat sciatic nerve was transected and repaired with a silicone guide containing a predegenerated segment of ventral root (VR) or dorsal root (DR), compared to a silicone guide filled with saline. Nerve regeneration and reinnervation was assessed during 3 months by electrophysiologic and functional tests, and by nerve morphology and immunohistochemistry against choline acetyltransferase (ChAT) for labeling motor axons. Functional tests showed that reinnervation was successful in all the rats. However, the two groups with a root allotransplant reached higher degrees of reinnervation in comparison with the control group. Group VR showed the highest reinnervation of muscle targets, whereas Group DR had higher levels of sensory reinnervation than VR and saline groups. The total number of regenerated myelinated fibers was similar in the three groups, but the number of ChAT+ fibers was slightly lower in the VR group in comparison with DR and saline groups. These results indicate that a predegenerated root nerve allotransplant enhances axonal regeneration, leading to faster and higher levels of functional recovery. Although there is not clear preferential reinnervation, regeneration of motor axons is promoted at early times by a motor graft, whereas reinnervation of sensory pathways is increased by a sensory graft. © 2007 Wiley‐Liss, Inc.
Ubiquitin‐proteasome system alterations in a striatal cell model of huntington's disease
Authors: Hunter Jesse M. , Lesort Mathieu , Johnson Gail V.W.
Published: April 2007

Huntington's disease (HD) is a progressive, autosomal dominant neurodegenerative disease caused by an abnormally expanded CAG repeat in the HD gene. Ubiquitylated aggregates containing mutant huntingtin protein in neurons are hallmarks of HD. Misfolded mutant huntingtin monomers, oligomers, or aggregates may be a result of, and cause, ubiquitin‐ proteasome dysfunction. To investigate the ubiquitin‐proteasome system we designed a series of firefly luciferase reporters targeted selectively to different points along this pathway. These reporters were used to monitor ubiquitin‐proteasome system function in a striatal cell culture model of HD. Ubiquitylation processes were not reduced in mutant huntingtin cells but recognition or degradation of ubiquitylated substrates was decreased. We also found mutant huntingtin expressing cells had slight but significant decreases in chymotrypsin‐like and caspase‐like activities, and an unexpected increase in trypsin‐like activity of the proteasome core. General proteasome core inhibitors, as well as selective caspase‐like activity inhibitors, were less effective in mutant cells. Finally, treatment with 3‐nitropropionic acid, a succinate dehydrogenase inhibitor, had opposite effects on the ubiquitin‐proteasome system with activation in wild‐type and decreased activity in mutant huntingtin expressing cells. The results of these experiments show clearly selective disruption of the ubiquitin‐proteasome system in this cell culture model of HD. The high throughput tools that we have designed and optimized will also be useful in identifying compounds that alter ubiquitin‐proteasome system function and to investigate other neurodegenerative diseases such Alzheimer's disease and Parkinson's disease. © 2007 Wiley‐Liss, Inc.
Expression of insulin‐like growth factor system genes during the early postnatal neurogenesis in the mouse hippocampus
Authors: Zhang Jihui , Moats‐Staats Billie M. , Ye Ping , D'Ercole A. Joseph
Published: April 2007

Insulin‐like growth factor‐1 (IGF‐1) is essential to hippocampal neurogenesis and the neuronal response to hypoxia/ischemia injury. IGF (IGF‐1 and ‐2) signaling is mediated primarily by the type 1 IGF receptor (IGF‐1R) and modulated by six high‐affinity binding proteins (IGFBP) and the type 2 IGF receptor (IGF‐2R), collectively termed IGF system proteins. Defining the precise cells that express each is essential to understanding their roles. With the exception of IGFBP‐1, we found that mouse hippocampus expresses mRNA for each of these proteins during the first 2 weeks of postnatal life. Compared to postnatal day 14 (P14), mRNA abundance at P5 was higher for IGF‐1, IGFBP‐2, ‐3, and ‐5 (by 71%, 108%, 100%, and 98%, respectively), lower for IGF‐2, IGF‐2R, and IGFBP‐6 (by 65%, 78%, and 44%, respectively), and unchanged for IGF‐1R and IGFBP‐4. Using laser capture microdissection (LCM), we found that granule neurons and pyramidal neurons exhibited identical patterns of expression of IGF‐1, IGF‐1R, IGF‐2R, IGFBP‐2, and ‐4, but did not express other IGF system genes. We then compared IGF system expression in mature granule neurons and their progenitors. Progenitors exhibited higher mRNA levels of IGF‐1 and IGF‐1R (by 130% and 86%, respectively), lower levels of IGF‐2R (by 72%), and similar levels of IGFBP‐4. Our data support a role for IGF in hippocampal neurogenesis and provide evidence that IGF actions are regulated within a defined in vivo milieu. © 2007 Wiley‐Liss, Inc.
Correlation and characterisation of individual glass shards from tephra deposits using trace element laser ablation ICP‐MS analyses: current status and future potential
Authors: Pearce Nicholas J. G. , Denton Joanna S. , Perkins William T. , Westgate John A. , Alloway Brent V.
Published: April 2007

Laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) is a high spatial resolution analytical method which has been applied to the analysis of silicic tephras. With current instrumentation, around 30 trace elements can be determined from single glass shards as small as ∼ 40 µm, separated from tephra deposits. As a result of element fractionation during the ablation process using a 266 nm laser, a relatively complex calibration strategy is required. Nonetheless, such a strategy gives analyses which are accurate (typically within ±5%) and have an analytical precision which varies from ∼ ±2% at 100 ppm, to ∼ ±15% at 1 ppm. Detection limits for elements used in correlation and discrimination studies are well below 1 ppm. Examples of the application of trace element analysis by LA‐ICP‐MS in tephra studies are presented from the USA, New Zealand and the Mediterranean.

Improvements in instrumental sensitivity in recent years have the potential to lower detection limits and improve analytical precision, thus allowing the analysis of smaller glass shards from more distal tephras. Laser systems operating at shorter wavelengths (e.g. 193 nm) are now more widely available, and produce a much more controllable ablation in glasses than 266 nm lasers. Crater sizes of <10 µm are easily achieved, and at 193 nm many of the elemental fractionation issues which mar longer wavelengths are overcome. By coupling a short wavelength laser to a modern ICP‐MS it should be possible to determine the trace element composition of glass shards as small as 20 µm and, providing sample preparation issues can be overcome, the determination of the more abundant trace elements in glass shards as small as 10 µm is within instrumental capabilities. This will make it possible to chemically fingerprint tephra deposits which are far from their sources, and will greatly extend the range over which geochemical correlation of tephras can be undertaken. Copyright © 2007 John Wiley & Sons, Ltd.
Ultrasound, computed tomography, or the combination for the detection of supraclavicular lymph nodes in patients with esophageal or gastric cardia cancer: a comparative study
Authors: van Vliet Evelyn P.M. , Lugt Aad van der , Kuipers Ernst J. , Tilanus Hugo W. , Gaast Ate van der , Hermans John J. , Siersema Peter D.
Published: April 2007

Background and Objectives

Both ultrasound (US) and computed tomography (CT) can be used to detect supraclavicular lymph node metastases. Aim was to compare US, US plus fine‐needle aspiration (US‐FNA), CT, US + CT, and US‐FNA + CT for the detection of these metastases in esophageal or gastric cardia cancer patients.

Methods

Between 1994 and 2004, 567 patients underwent US and CT for esophageal or gastric cardia cancer staging. Gold standard was postoperative detection of lymph nodes in the resected specimen, FNA, or a radiological result with follow‐up.

Results

Sensitivities of US (75%), US‐FNA (72%), US + CT (80%), and US‐FNA + CT (79%) were higher than sensitivity of CT alone (25%) (P < 0.001). Specificities were high for US‐FNA (100%), CT (99%), and US‐FNA + CT (99%), whereas those of US alone (91%) and US + CT (91%) were lower (P < 0.001). In 4/65 (6%) patients with true‐positive malignant lymph nodes, CT was positive with US and/or US‐FNA being negative. However, in 36/65 (55%) patients, US and/or US‐FNA were positive with CT being negative.

Conclusion

US‐FNA seems the preferred diagnostic modality for the detection of supraclavicular lymph node metastases in patients with esophageal or gastric cardia cancer. Sensitivity of metastases detection only slightly improves if US‐FNA is combined with CT. A prospective, comparative study is however needed. J. Surg. Oncol. 2007;96: 200–206. © 2007 Wiley‐Liss, Inc.
On Generating Functions for a New Class of Polynomials II
Authors: Gupta K. C. , Goyal S. P.
Published: April 2007

This paper is in continuation to our recent paper [4] in this journal. Here we obtain three more bilinear generating functions involving the products of a new class of polynomials. JACOBI polynomial and LAGUERRE polynomials. Various interesting and new bilinear and trilinear generating functions involving the products of JACOBI polynomials, GEGENBAUER polynomials, LAGUERRE polynomials and RICE's polynomials, follow as particular cases of our main results.
Asymptotic Light Cone Structure in Cosmological Models of BIANCHI Type I
Authors: Abdel‐Megied M. , Dautcourt G.
Published: April 2007

The inner metric of general light cone in a BIANCHI type I geometry is determined. No focal surface can occur. The singularities which appear in the cosmological solutions of the EINSTEIN field equations at some past instant of time are shown to appear also as singularities of the inner light cone geometry. The behaviour of null geodesies constituting the light cone is studied in the neighbourhood of their singularities.
Über algebraische Eigenschaften einer Klasse von Operatorenmatrizen und eine Anwendung auf singuläre Integraloperatoren
Authors: Köhler Uwe , Silbermann Bernd
Published: April 2007

In dieser Arbeit wird ein algebraischer Satz bewiesen, aus dem sich eine Reihe von bislang unbekannten Resultaten über Operatorenmatrizen ableiten lassen. Einige dieser Resultate werden benutzt, um eine Klasse singulärer Integraloperatorem nicht normalen Typs im Raume der beliebig oft differenzierbaren Funktionen zu untersuchen.
Motor unit number estimates and quantitative motor unit analysis in healthy subjects and patients with amyotrophic lateral sclerosis
Authors: Boe Shaun G. , Stashuk Daniel W. , Doherty Timothy J.
Published: April 2007

Limitations associated with global measures of function in patients with amyotrophic lateral sclerosis (ALS) and the qualitative nature of needle electromyography have stimulated the development of alternate means of monitoring disease severity and progression in ALS. Thus, the objective of this study was to examine the ability of one these techniques, decomposition‐based quantitative electromyography (DQEMG), to obtain electrophysiological data, including motor unit number estimates (MUNEs), from a group of patients with ALS. The first dorsal interosseous and biceps brachii muscles were studied in 10 healthy subjects and 9 patients with ALS. Following the acquisition of a maximum M wave, needle‐ and surface‐detected EMGs were collected simultaneously during 30‐second contractions performed at 10% of the maximum voluntary contraction force to obtain motor unit potential (MUP) trains. DQEMG was then used to extract the surface‐detected MUP associated with each MUP train, the mean size of which was divided into the maximum M wave to obtain a MUNE. The results suggest that quantitative electrophysiological data obtained using DQEMG are representative of the pathophysiological changes in the lower motor system in ALS patients, supporting its use in studies documenting the natural history and progression of the disease. Muscle Nerve, 2007
Contribution of reference electrode to the compound muscle action potential
Authors: Nandedkar Sanjeev D. , Barkhaus Paul E.
Published: April 2007

In compound muscle action potential (CMAP) recording, the contribution by the reference electrode is considered to be much smaller than that of the active electrode. We tested this assumption by making quantitative measurements of the signals recorded individually by the active and reference electrodes. In the thenar (median nerve) and extensor digitorum brevis (peroneal nerve) muscles, the reference electrode did contribute less. In the hypothenar muscle (ulnar nerve), however, the signals recorded by active and reference electrodes were of similar amplitude. In tibial nerve conduction studies (NCS), the CMAP from the abductor hallucis (AH) muscle was recorded mainly by the reference electrode; the large‐amplitude signal recorded by the reference electrode is attributed to volume‐conducted activity from other muscles stimulated during the study. The onset latency of the potential recorded by the active and reference electrodes was similar despite significantly different distances from the stimulating site. Hence, the merits of using anatomic landmarks for defining the distal stimulation site are assessed. When the reference electrode makes a large contribution, the CMAP amplitude may not decrease commensurate with any wasting of the muscle under the active recording electrode, and the need to use another muscle for recording the CMAP for that nerve should be considered. Muscle Nerve, 2007
Consolidation of sensitive clay with vertical drain
Authors: Chen Yun‐Min , Tang Xiao‐Wu , Jia Ning
Published: April 2007

The coefficient of consolidation is one of the most important parameters that control the rate of consolidation. Conventional consolidation theories assume that the coefficient of consolidation is constant during the whole consolidation process. In the case of sensitive clay, the coefficient of consolidation is strongly dependent on the level of effective stress of clay. With the dissipation of pore water pressure and the increase of effective stress, the soil structure of the upper subsoil is gradually destroyed downwards and its coefficient of consolidation becomes smaller. At the same
time, the coefficient of permeability of the vertical drains drops down because of the kinking or bending effect. The destructured upper subsoil and the kinking of the vertical drain hinder the dissipation of the pore pressure in the lower subsoil.

This paper presents a model to describe the above important phenomena during the consolidation of sensitive clay with vertical drain. The solution for proposed model can be obtained by extending the closed‐form solution of the consolidation of double‐layered ground with vertical drain by the interactive method introducing the concept of the moving boundary and the reduction of discharge capacity of vertical drain. The numerical results obtained from the finite element method package PLAXIS (Ver. 7.2) are adopted to compare those obtained from the present algorithm. Moreover, the rationality of the moving boundary is explained by the distributions of the excess pore water pressure in natural soil zone along the radial direction. Wenzhou airport project is taken as a case study in this paper. The results for the sensitive soil with decaying sand drain agree very well with the in situ measured data. The calculated results can properly explain two general phenomena observed in the consolidation of soft sensitive soil ground with vertical drains: one is that the time to achieve the same consolidation degree is much longer under heavy loading than that under light loading; the other is that the consolidation speed is much slower in the lower subsoil than in the upper subsoil. Finally, it is indicated that the vertical drains can decrease the hindrance effect of the destructured subsoil. Copyright © 2007 John Wiley & Sons, Ltd.
Bladder dysfunction in type 2 diabetic patients
Authors: Kebapcı Nur , Yenilmez Aydin , Efe Belgin , Entok Emre , Demirustu Canan
Published: April 2007

Aims

To reevaluate urodynamic findings of bladder dysfunction (BD) in type 2 diabetic patients with patient characteristics and concommittant chronic complications.

Methods

Patients (M/F:27/27) with lower urinary tract symptoms (LUTS) underwent a detailed urodynamic investigation. Urodynamic findings were classified as diabetic cystopathy [DC, characterized by impaired bladder sensation, increased post‐void residual urine (PVR) and increased bladder capacity and decreased bladder contractility], detrusor overactivity, bladder outlet obstruction (BOO), urge and stress urinary incontinence or BD in which one of the alterations was included. Glycated hemoglobin (HbA1C), diabetic retinopathy, nephropathy, sensorimotor, and autonomic neuropathies were evaluated.

Results

BD was present in 74.07% of men (DC, 50%; BOO, 25%; detrusor overactivity, 25%) and in 59.26% of diabetic women (DC, 43.75%; detrusor overactivity, 31%; urge incontinence, 12.5%; stress urinary incontinence 12.5%). In men, age, duration of diabetes and HbA1C threshold values predicting BD were >64 years, >9 year, >7.9%, while in women, they were >56 years, >8 years, >7%, respectively. Prolongation of QTc, abnormal esophageal transit and gastric emptying times, diabetic retinopathy, and microalbuminuria were associated with an increased risk of PVR ≥ 100 ml.

Conclusions

DC was the most frequent finding in patients. Ageing, duration of diabetes, worse metabolic control, PVR 100 ml, cardiac, esophageal and gastric parasympathetic autonomic neuropathies, retinopathy, and microalbuminuria provided a means to predict BD in patients in order to investigate by urodynamics. The establishment of DC in at least 8–9 years after the diagnosis of type 2 DM was an important parameter to inform our diabetic patients. Neurourol. Urodynam. 26:814–819, 2007. © 2007 Wiley‐Liss, Inc.
Modification of sulfonated poly(ether ether ketone) with phenolic resin
Authors: Deb P. C. , Rajput L. D. , Hande V. R. , Sasane S. , Kumar A.
Published: April 2007

Soluble phenol formaldehyde resin containing hydroxymethyl groups has been used to modify sulfonated poly(ether ether ketone) (SPEEK). Modification has been carried out with films containing both the polymers and using dimethyl formamide (DMF) as casting solvent at various temperatures under reduced pressure. Associated solvent and the hydrogen‐bonded by‐product dimethyl amine (DMA) were removed through mild alkali–acid–water treatment. Cured and treated films show good and consistent mechanical properties, water uptake (22–25%), ion‐exchange capacity (1.1–1.5 meq/g) and proton conductivity (125–150 mS/cm) at 30°C and hold promise for application in fuel cells, as indicated by a polarization study in a fuel cell test station. Copyright © 2007 John Wiley & Sons, Ltd.
The secretory leukocyte protease inhibitor (SLPI) suppresses cancer cell invasion but promotes blood‐borne metastasis via an invasion‐independent pathway
Authors: Sugino T , Yamaguchi T , Ogura G , Kusakabe T , Goodison S , Homma Y , Suzuki T
Published: April 2007

An invasion‐independent pathway has been proposed as a novel mechanism in blood‐borne metastasis, where tumour cells enveloped by sinusoidal tumour vessels enter the circulation without vascular invasion. We previously identified the secretory leukocyte protease inhibitor (SLPI) as a candidate gene responsible for this pathway. In this study, the functional role of SLPI in metastatic dissemination was investigated. We transfected the SLPI gene into a poorly metastatic clone of the MCH66 mouse mammary tumour cell line. Over‐expression of SLPI promoted in vivo growth and spontaneous metastasis to the lung, whereas it suppressed invasive activity in vitro. The inoculated tumours of SLPI‐transfectants exclusively induced a sinusoidal vasculature and subsequently produced endothelial‐coated tumour emboli, which are morphological indices of the invasion‐independent pathway. In addition, exogenous SLPI inhibited the migration activity through Matrigel of both tumour cells and human umbilical vein endothelial cells (HUVECs). In vivo angiogenesis assays also demonstrated that SLPI suppressed the migration of newly formed blood vessels. These results suggest that an anti‐migratory effect of SLPI on tumour‐associated endothelial cells may induce vascular remodelling to form a sinusoidal architecture, and consequently promote invasion‐independent metastasis. This study provides a new model for metastasis, based on the mechanism regulated by anti‐invasive factors, such as SLPI. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Pulmonary dysfunction and impaired granulocyte homeostasis result in poor survival of Jam‐C‐deficient mice
Authors: Imhof BA , Zimmerli C , Gliki G , Ducrest‐Gay D , Juillard P , Hammel P , Adams R , Aurrand‐Lions M
Published: April 2007

Jam‐C−/− mice exhibit growth retardation and multilobular pneumonia concomitant with poor survival of the mice under conventional housing conditions. The deficient mice present a mega‐oesophagus and have altered airway responsiveness. In addition, the number of circulating granulocytes is increased in Jam‐C−/− mice as compared to control animals. These phenotypes probably reflect the different functions of JAM‐C expressed by endothelial and mesenchymal cells. Indeed, the deregulation in the number of circulating granulocytes is caused by the lack of JAM‐C expression on endothelial cells since rescuing endothelial expression of the protein in the Jam‐C−/− mice is sufficient to restore homeostasis. More importantly, the rescue of vascular JAM‐C expression is accompanied by better survival of deficient mice, suggesting that endothelial expression of JAM‐C is mandatory for animal survival from opportunistic infections and fatal pneumonia. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.