bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sorption kinetics and equilibrium uptake for water vapor in soft‐contact‐lens hydrogels
Authors: Weinmüller C. , Langel C. , Fornasiero F. , Radke C.J. , Prausnitz J.M. 
Published: January 2006

AbstractA gravimetric‐sorption technique was used to obtain kinetic and equilibrium adsorption/desorption data for water vapor in four different soft‐contact‐lens (SCL) polymers at 35°C. The SCL materials are a conventional hydrogel (polymacon) with a low water content at saturation (<50 wt %); two conventional hydrogels (hilafilcon A and alphafilcon A) with a high water content at saturation (>50 wt %); and a siloxane hydrogel (balafilcon A). Absorption and desorption equilibrium isotherms (water activity versus water weight fraction) overlap at high water contents, whereas significant hysteresis is observed at low water contents. The hysteresis loop is likely due to trapping of water in the polymer during the desorption process because of a rubber‐to‐glass transition of the SCL‐film surfaces. Sorption data were interpreted using Flory–Rehner theory. The positive Zimm and Lundberg cluster function suggests that water tends to cluster in these SCL materials, except at very low water content. For polymacon and hilafilcon A, Fickian diffusion is observed for all activities for both water sorption and desorption. However, for alphafilcon A and balafilcon A, non‐Fickian features appear at intermediate/low activities, in particular during water desorption, suggesting coupling of the diffusion process with polymer‐matrix relaxation. The diffusion coefficient increases significantly with water concentration for polymacon and hilafilcon A (from ∼0.3 × 10−8 to 4.0 × 10−8 cm2/s) because of augmented mixture free volume induced by water sorption, whereas a more complex composition dependence is observed for alphafilcon A and balafilcon A probably as consequence of a combined effect of polymer relaxation, plasticization, and water clustering. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Chemokine gene activation in human bone marrow‐derived osteoblasts following exposure to particulate wear debris
Authors: Fritz Elizabeth A. , Glant Tibor T. , Vermes Csaba , Jacobs Joshua J. , Roebuck Kenneth A. 
Published: January 2006

AbstractParticulate wear debris induces the expression of pro‐inflammatory cytokine and chemokine genes in various cell types of the periprosthetic region. We have previously reported that titanium particles stimulate the selective induction of interleukin‐8 (IL‐8) and monocyte chemoattractant protein‐1 (MCP‐1) chemokines in human osteoblast‐like osteosarcoma cells. In this study, we characterize the human bone marrow‐derived osteoblast chemokine response to titanium particles. We demonstrate that titanium particles result in enhanced IL‐8 and MCP‐1 protein secretion as well as differential chemokine gene activation. Osteoblast chemokine expression was regulated at the level of gene transcription, with a time‐dependent induction of NF‐κB activation. Inhibition studies with N‐acetyl‐L‐cysteine (Nac) and MG‐132 suggest that titanium particle activation of NF‐κB activity and IL‐8 chemokine exression involves oxidant signaling and IκBα‐proteasomal degradation. Activation of the NF‐κB transcription factor, as well as the IL‐8 gene, are redox‐regulated. We also demonstrate that while cytochalasin D, a potent inhibitor of phagocytosis, suppressed the titanium particle effect on IL‐8 protein release in human bone marrow‐derived osteoblasts, the inhibitor had no effect on IL‐8 expression in MG‐63 osteoblast‐like cells. Collectively, these results provide insight into the potential mechanisms responsible for the particulate activation of osteoblast chemokine expression and suggest an important role for the osteoblast in the pathogenesis of periprosthetic osteolysis. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Effect of degradation rates of resorbable phosphate invert glasses on in vitro osteoblast proliferation
Authors: Brauer Delia S. , Rüssel Christian , Li Wu , Habelitz Stefan 
Published: January 2006

AbstractFour resorbable phosphate invert glasses for use as bone replacement were synthesized in the system P2O5CaOMgONa2O. TiO2 and SiO2 were added at concentrations of 1 and 5.5 mol % to control solubility and crystallization. Both bulk glasses and samples with an open porosity of 65% and pore sizes of 150 to 400 μm were produced using a salt sintering process. Addition of TiO2 decreased the solubility in water and simulated body fluid, while the glass with addition of SiO2 showed a higher dissolution rate than did the original glass. The hypothesis that dissolution rates of the glasses will affect cell proliferation of osteoblastlike cells was tested using a MC3T3‐E1.4 murine preosteoblast cell line. Cells were cultured on nonporous polished and porous glasses with tissue culture polystyrene (TCPS) as control. Cell proliferation was studied over 24 and 72 h in culture. Cells proliferated on all polished glasses, but proliferation on porous glasses showed variations with glass composition. Cell proliferation increased with decreased solubility of the glass. It is suggested that resorbable implant materials require the adjustment of dissolution rate so as to facilitate cell adhesion and proliferation and thus a gradual transition from artificial implant to new bone structure. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Fabrication of microporous polyurethane by spray phase inversion method as small diameter vascular grafts material
Authors: Khorasani M.T. , Shorgashti S. 
Published: January 2006

AbstractMicroporous polyurethane vascular prostheses with a 4 mm diameter and 0.3–0.4 mm wall thickness were fabricated by a spray phase inversion technique. In this study, the effect of distance between spray guns (SG) and rotating mandrel (RM), the effect of rate of rotating mandrel (RRM), and the type of nonsolvent on pore morphology of PU films were evaluated using scanning electron microscopy (SEM) technique. It was observed that when the distance between SG and RM was increased or the rate of RM was decreased, the porosity of PU films increased and consequently the tensile strength decreased and compliance value increased. Compliance was measured in vitro by volume and vessel diameter changes. Furthermore, when the coagulant (water) was changed to the water/methanol, the porosity of PU film increased and porous morphology changed to filamentous morphology. Attachment of anchorage dependent cells, namely L929 fibroblast cells, were investigated in stationary culture conditions. The cells adhesion and cells growth were studied using optical photomicrographs. The results show that by increasing the porosity content of PU films would consequently increase the cell ingrowths. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Physicochemical properties of TTCP/DCPA system cement formed in physiological saline solution and its cytotoxicity
Authors: Dagang Guo , Kewei Xu , Haoliang Sun , Yong Han 
Published: January 2006

AbstractIn this paper, the physicochemical properties and cytotoxicity of calcium phosphate cement (CPC), prepared by mixing cement powders of tetracalcium phosphate (TTCP) and dicalcium phosphate (DCPA) with a cement liquid of physiological saline solution, were investigated. The microstructure evolution of various hardened cement bodies and their hydration crystals as a function of immersion time in similar physiological fluids, physiological saline solution (0.9% NaCl), or simulated body fluids (SBF), were also studied. Results show that the setting time of CPC is in the range of 12–15 min, which meets the clinical application demands. We also found that the mean compressive strength of the CPC samples immersed in SBF for 3 days is 104 ± 10 MPa which reaches the transverse compressive strength, 106–133 MPa, of human long bone. The results obtained from both the X‐ray powder diffraction analyses (XRD) and scanning electron microscopy (SEM) observations indicated that a reinforcing effect of some remaining TTCP particles in the early stages of immersion is mainly responsible for the increase in the initial strength. Although the CPC failed to keep this high level when immersed for a longer time, the initial reinforcing effect of the remaining TTCP particles provides advantages for clinical applications. This would be effective when the material is loaded at the very beginning of the implantation, especially for the material used as a fixation, which requires a certain initial strength in the early stages of the implantation. The cytotoxicity results showed that the relative growth rate (RGR%) of L929 cells on the CPC samples using physiological saline solution as a cement liquid was slightly superior to that of the samples using the 0.5 mol/L phosphate acid solution as the cement liquid. This was most likely caused by the pH difference between the two CPC samples immersed in a DMEM–BFS medium. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Crosslinked poly(ϵ‐caprolactone/D,L‐lactide)/bioactive glass composite scaffolds for bone tissue engineering
Authors: Meretoja V.V. , Helminen A.O. , Korventausta J.J. , Haapa‐aho V. , Seppälä J.V. , Närhi T.O. 
Published: January 2006

AbstractA series of elastic polymer and composite scaffolds for bone tissue engineering applications were designed. Two crosslinked copolymer matrices with 90/10 and 30/70 mol % of ϵ‐caprolactone (CL) and D,L‐lactide (DLLA) were prepared with porosities from 45 to 85 vol % and their mechanical and degradation properties were tested. Corresponding composite scaffolds with 20–50 wt % of particulate bioactive glass (BAG) were also characterized. Compressive modulus of polymer scaffolds ranged from 190 ± 10 to 900 ± 90 kPa. Lactide rich scaffolds absorbed up to 290 wt % of water in 4 weeks and mainly lost their mechanical properties. Caprolactone rich scaffolds absorbed no more than 110 wt % of water in 12 weeks and kept their mechanical integrity. Polymer and composite scaffolds prepared with P(CL/DLLA 90/10) matrix and 60 vol % porosity were further analyzed in simulated body fluid and in osteoblast culture. Cell growth was compromised inside the 2 mm thick three‐dimensional scaffold specimens as a static culture model was used. However, composite scaffolds with BAG showed increased osteoblast adhesion and mineralization when compared to neat polymer scaffolds. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Effects of surface roughness and maximum load on the mechanical properties of cancellous bone measured by nanoindentation
Authors: Donnelly Eve , Baker Shefford P. , Boskey Adele L. , van der Meulen Marjolein C.H. 
Published: January 2006

AbstractThe effects of two key experimental parameters on the measured nanomechanical properties of lamellar and interlamellar tissue were examined in dehydrated rabbit cancellous bone. An anhydrous sample preparation protocol was developed to maintain surface integrity and produce RMS surface roughnesses ∼10 nm (5 × 5‐μm2 area). The effects of surface roughness and maximum nanoindentation load on the measured mechanical properties were examined in two samples of differing surface roughness using maximum loads ranging from 250 to 3000 μN. As the ratio of indentation depth to surface roughness decreased below ∼3:1, the variability in material properties increased substantially. At low loads, the indentation modulus of the lamellar bone was ∼20% greater than that of the interlamellar bone, while at high loads the measured properties of both layers converged to an intermediate value. Relatively shallow indentations made on smooth surfaces revealed significant differences in the properties of lamellar and interlamellar bone that support microstructural observations that lamellar bone is more mineralized than interlamellar bone. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Protein transduction into human cells by adenovirus dodecahedron using WW domains as universal adaptors
Authors: Garcel A. , Gout E. , Timmins J. , Chroboczek J. , Fender P. 
Published: January 2006

AbstractBackgroundDirect protein transduction is a recent technique that involves use of peptide vectors. In this study, we demonstrate that adenovirus dodecahedron (Dd), a virus‐like particle devoid of DNA and able to penetrate cells with high efficiency, can be used as a vector for protein delivery.MethodsTaking advantage of Dd interaction with structural domains called WW, we have elaborated a universal adaptor to attach a protein of interest to this vector.ResultsA tandem of three WW structural domains derived from the Nedd4 protein enables the formation of stable complexes with Dd, without impairing its endocytosis efficiency. Our protein of interest fused to the triple WW linker is delivered by the dodecahedron in 100% of cells in culture with on average more than ten million molecules per cell.ConclusionThese data demonstrate the great potential of adenovirus dodecahedron in combination with WW domains as a protein transduction vector. Copyright © 2006 John Wiley & Sons, Ltd.
Mixed hematopoietic molecular chimerism results in permanent transgene expression from retrovirally transduced hepatocytes in mice
Authors: Pichard Virginie , Bellodi‐Privato Marta , Gournay Jérôme , Ferry Nicolas 
Published: January 2006

AbstractBackgroundCytotoxic immune elimination of transduced hepatocytes may limit gene therapy for inherited liver diseases. Using β‐galactosidase as a marker gene, we studied whether creation of mixed β‐galactosidase molecular hematopoietic chimerism could induce tolerance to β‐galactosidase‐transduced hepatocytes.MethodsMolecular hematopoietic chimerism was established in irradiated recipient mice by transplantation of either a mixture of wild‐type and β‐galactosidase‐transgenic bone marrow or autologous bone marrow stem cells that were transduced with β‐galactosidase lentiviral vectors. After transplantation, mice were hepatectomized and injected with β‐galactosidase recombinant retroviruses to transduce regenerating hepatocytes. We monitored the presence of β‐galactosidase‐expressing hepatocytes as well as the appearance of anti‐β‐galactosidase antibodies during the time.ResultsIn control animals, anti‐β‐galactosidase antibodies and cytotoxic T‐lymphocyte (CTL) response developed as early as 3 weeks after gene transfer. Transduced hepatocytes disappeared concomitantly. In bone marrow transplanted mice, tolerance could be observed in a significant proportion of animals. Tolerance resulted in permanent liver transgene expression and was absent unless a chimerism above 1% was achieved, demonstrating a threshold effect.ConclusionsCreation of a molecular hematopoietic chimerism can result in transgene tolerance and evade immune rejection of retrovirally transduced hepatocytes. This strategy may be useful for hepatic inherited diseases in which the transgene product behaves as a non‐self protein. Copyright © 2006 John Wiley & Sons, Ltd.
Brain engraftment and therapeutic potential of stem/progenitor cells derived from mouse skin
Authors: Tunici Patrizia , Bulte Jeff W. M. , Bruzzone Maria Grazia , Poliani Pietro Luigi , Cajola Laura , Grisoli Marina , Douglas Trevor , Finocchiaro Gaetano 
Published: January 2006

AbstractSkin stem/progenitor cells (SKPs) derive from the dermis and in culture can generate mesodermal and neural progenies. To investigate their potential for the treatment of brain diseases, we first injected SKPs into the brain of syngeneic mice. Brain histology indicated that most SKPs remained undifferentiated and clustered at the injection site, while, in vitro, 17% of SKPs expressed neural markers, as assessed by flow cytometry. After labeling with magnetodendrimers, murine and human SKPs were detected by magnetic resonance imaging even 5 months after brain injection. To evaluate their therapeutic potential on malignant gliomas, IL‐4 SKPs (i.e. SKPs transduced by a lentiviral vector carrying the cDNA of the anti‐glioma cytokine interleukin‐4) were injected into GL261 experimental gliomas. IL‐4‐SKPs prolonged significantly the survival of tumor‐bearing mice: furthermore, GL261 gliomas attracted SKPs originally injected into the contralateral hemisphere. Thus, prolonged survival, capacity for transgene expression, and lack of uncontrolled proliferation suggest that SKPs warrant further consideration as therapeutic tools for brain tumors and, possibly, other neurological disorders. Copyright © 2006 John Wiley & Sons, Ltd.
Convenient synthesis of deuterated glutamic acid, proline and leucine via catalytic deuteration of unsaturated pyroglutamate derivatives
Authors: Oba Makoto , Ohkuma Kosuke , Hitokawa Hiroshi , Shirai Ayumi , Nishiyama Kozaburo 
Published: January 2006

AbstractNovel 3,4‐didehydropyroglutamate derivatives, the key intermediates in this synthesis, were obtained from a protected pyroglutamate by the well‐known selenenylation‐oxidative deselenenylation method and were catalytically deuterated using a slow‐addition technique. The obtained deuterated pyroglutamates were converted to [3,4‐2H2]glutamic acid, [3,4,5‐2H3]proline, and [3,4,5,5,5‐2H5]leucine via an appropriate functional group interconversions followed by the standard deprotection procedure. Copyright © 2006 John Wiley & Sons, Ltd.
A novel asymmetric synthesis of tritium and carbon‐14 labeled (R)‐ibuprofen
Authors: Zhang Yinsheng , Hong Yang , Huang Che C. , Belmont Daniel 
Published: January 2006

AbstractAn efficient asymmetric synthesis of tritium and carbon‐14 labeled R‐ibuprofen was achieved in good overall yield (15% and 47%, respectively) and excellent enantiomerical excess (>98% e.e.), using (4R, 5S)‐4‐methyl‐5‐phenyl‐2‐oxazolidinone as a chiral auxiliary. Copyright © 2006 John Wiley & Sons, Ltd.
Acoustic communication and burrow acoustics are reflected in the ear morphology of the coruro (Spalacopus cyanus, Octodontidae), a social fossorial rodent
Authors: Begall Sabine , Burda Hynek 
Published: January 2006

AbstractWe studied the middle and inner ears of seven adult coruros (Spalacopus cyanus), subterranean and social rodents from central Chile, using free‐hand dissection and routine staining techniques. Middle ear parameters that were focused on here (enlarged bullae and eardrums, ossicles of the “freely mobile type”) are believed to enhance hearing sensitivity at lower frequencies. The organ of Corti was of a common mammalian type and revealed three peaks of higher inner hair cell densities. Based on a position frequency map, frequencies were assigned to the respective peaks along the basilar membrane. The first peak at around 300–400 Hz is discussed with respect to the burrow acoustics, while the peak around 10–20 kHz is probably a plesiomorphic feature. The most pronounced peak at around 2 kHz reflects the frequency at which the main energy of vocal communication occurs. The morphology of the ear of the coruro corresponds to the typical pattern seen in subterranean rodents (low frequency and low‐sensitivity hearers), yet, at the same time, it also deviates from it in several functionally relevant features. J. Morphol. © 2006 Wiley‐Liss, Inc.
Gravity‐dependent signal gradients on MR images of the lung in supine and prone positions: A comparison with isogravitational signal variability
Authors: Bankier Alexander A. , Storey Pippa , Mai Vu M. , Edelman Robert R. , Chen Qun 
Published: January 2006

AbstractPurposeTo investigate the tendency of proton MR signal intensity (SI) gradients to be steeper in the supine than in the prone body position, and to quantify the relation between gravity‐related and isogravitational changes of SI on proton MR images of the lung.Materials and MethodsIn eight healthy volunteers, MR images were obtained in the supine and prone positions using a multiple inversion recovery turbo spin‐echo (TSE) sequence. The variation in SI along the gravity‐dependent direction and within isogravitational planes was measured on a pixel‐by‐pixel basis. Ratios of slopes were calculated for comparisons among volunteers. Comparisons of ratios were made using Fisher's exact test. Isogravitational variability was compared with the mean SI, the signal‐to‐noise ratio (SNR), and the image noise.ResultsThe average ratios of slopes showed that the overall SI gradient was steeper in the supine than the prone position, with a substantial difference in the supine/prone ratios between inspiration (1.21) and expiration (1.72). In both the supine and prone positions, gravity‐dependent gradients were steeper in expiration than in inspiration (P = 0.001). The SI variability along the gravitational direction was larger than the isogravitational variability. The isogravitational variability in turn was larger than the image noise but smaller than the mean SI of the MR images.ConclusionGravity‐dependent gradients in proton MR SI are steeper in the supine than in the prone position. The magnitudes of these gradients were larger than the isogravitational signal variability, showing that MRI is sensitive to gravitationally induced effects. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Administration of baclofen, a γ‐aminobutyric acid type B agonist in the thalamic ventrobasal complex, attenuates allodynia in monoarthritic rats subjected to the ankle‐bend test
Authors: Potes Catarina Soares , Neto Fani Lourença , Castro‐Lopes José Manuel 
Published: January 2006

Abstractγ‐Aminobutyric acid type B (GABAB) receptors are involved in the modulation of neuronal activity in response to chronic noxious input. However, the effect of their activation in chronic inflammatory pain in relay thalamic nuclei such as the ventrobasal complex (VB) is not known. In this study, experimental groups of 2, 4, and 14 days monoarthritic (MA) rats were injected with saline (controls) or baclofen (0.875 μg), a specific GABAB receptor agonist, in the VB contralateral to the inflamed joint, and the ankle‐bend test was performed. Ankle‐bend scores in control animals were near the maximum and were rather constant throughout the entire experimental period, indicating severe nociception. The same was observed in 2 days MA rats injected with baclofen. In the 4 days MA group, the response to baclofen injection was inconsistent among different animals, whereas, in 14 days MA rats, baclofen caused clear antinociceptive effects. Additionally, a 0.5 μg dose of baclofen was tested in 14 days MA rats, but no effect was observed, whereas a 1.25 μg dose produced visible side effects. Baclofen injections that did not target the VB but reached neighboring nuclei were ineffective in reducing nociception. Data demonstrate that the activation of the GABAB receptors by baclofen in the VB of MA rats leads to a decrease of nociception. Moreover, the response depends on the time course of the disease, suggesting the occurrence of different excitatory states of thalamic VB neurons. In conclusion, GABAB receptors in the VB play an important role in chronic inflammatory pain processing. © 2006 Wiley‐Liss, Inc.