bluuebunny/crossref_metadata_2025_split huggingface dataset:
Incorporation of growth factor containing Matrigel promotes vascularization of porous PLGA scaffolds
Authors: Laschke M. W. , Rücker M. , Jensen G. , Carvalho C. , Mülhaupt R. , Gellrich N.‐C. , Menger M. D. 
Published: August 2007

AbstractIn tissue engineering, rapid ingrowth of blood vessels into scaffolds is a major prerequisite for the survival of three‐dimensional tissue constructs. In the present study, we investigated whether the vascularization of implanted poly‐D,L‐lactic‐co‐glycolic acid (PLGA) scaffolds may be accelerated by incorporation of Matrigel. For this purpose, we investigated in the aortic ring assay the proangiogenic properties of growth factor reduced Matrigel (GFRM) and growth factor containing Matrigel (GFCM), which were then incorporated into the pores of PLGA scaffolds. Subsequently, we analyzed vascularization, biocompatibility, and incorporation of these scaffolds during 14 days after implantation into dorsal skinfold chambers of balb/c mice by means of intravital microscopy, histology, and immunohistochemistry. Matrigel‐free scaffolds served as controls. In the aortic ring assay, GFCM stimulated the development of a network of tubular vessel structures with a significantly increased sprout area and density when compared with GFRM. Accordingly, GFCM accelerated and improved in vivo the ingrowth of new blood vessels into scaffolds, resulting in the formation of a pericyte‐coated vascular network with an increased functional capillary density in comparison to the GFRM and control group. Besides, analysis of leukocyte–endothelial cell interaction in host tissue venules located in close vicinity to the scaffolds showed no marked differences in numbers of rolling and adherent leukocytes between the observation groups, indicating that incorporation of Matrigel did not affect biocompatibility of PLGA scaffolds. These findings demonstrate that the combination of proangiogenic extracellular matrices with solid scaffold biomaterials may represent a novel approach to accelerate adequate vascularization of tissue engineering constructs. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Cellular compatibility of bone‐like apatite containing silicon species
Authors: Obata Akiko , Kasuga Toshihiro 
Published: August 2007

AbstractA calcium carbonate/siloxane‐containing poly‐(lactic acid) composite (Si‐CCPC) was prepared by a sol‐gel method. Si‐CCPC was immersed in simulated body fluid for 3 days, resulting in the formation of bone‐like hydroxyapatite layer containing silicon species (b‐HA(Si)) on Si‐CCPC. The b‐HA(Si) was estimated in the cellular compatibility by culture tests using osteoblast‐like cells (MC3T3‐E1 cells), human mesenchymal stem cells (MSCs) and human osteoblasts (HOBs). Cellular number of MC3T3‐E1 cells and alkaline phosphatase activity of MSCs on the b‐HA(Si) increased significantly more in comparison with that on the conventional b‐HA (without silicon species). Cellular spreading of MC3T3‐E1 cells after 1 day of culturing was enhanced on the layer with and without silicon species. The b‐HA(Si) was expected to enhance cellular proliferation and osteogenic differentiation, and the b‐HA layer was believed to play the important role for cellular spreading. After 14 and 21 days of HOBs‐culturing, bone nodules formation was observed on the b‐HA(Si). The b‐HA(Si) has great potential in use as scaffolds for bone tissue engineering © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Scaffold permeability as a means to determine fiber diameter and pore size of electrospun fibrinogen
Authors: Sell Scott , Barnes Catherine , Simpson David , Bowlin Gary 
Published: August 2007

AbstractThe purpose of this study was to construct a flowmeter that could accurately measure the hydraulic permeability of electrospun fibrinogen scaffolds, providing insight into the transport properties of electrospun scaffolds while making the measurement of their topographical features (fiber diameter and pore size) more accurate. Three different concentrations of fibrinogen were used (100, 120, and 150 mg/mL) to create scaffolds with three different fiber diameters and pore sizes. The fiber diameters and pore sizes of the electrospun scaffolds were first analyzed with scanning electron microscopy and image analysis software. The permeability of each scaffold was measured with the flowmeter and used to calculate permeability‐based fiber diameters and pore sizes, which were compared to values obtained through image analysis. Permeability measurement revealed scaffold permeability to increase with fibrinogen concentration, much like average fiber diameter and pore size. Comparison between the two measurement methods demonstrated the efficacy of the flowmeter as a way to measure scaffold features. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Influence of nanohydroxyapatite patterns deposited by electrohydrodynamic spraying on osteoblast response
Authors: Thian E. S. , Huang J. , Ahmad Z. , Edirisinghe M. J. , Jayasinghe S. N. , Ireland D. C. , Brooks R. A. , Rushton N. , Best S. M. , Bonfield W. 
Published: August 2007

AbstractElectrohydrodynamic spraying has been used to produce patterns of line width up to 100 μm in size on glass discs, using nanohydroxyapatite (nHA). A human osteoblast (HOB)‐like cell model was then used to study the interaction between the HOB cells and nHA patterns in vitro. Growth of the cells was significantly increased (p < 0.05) on the nHA surfaces. In addition, HOBs attached and spread well, secreting extracellular matrix. It was found that a confluent, aligned cell layer was achieved on nHA patterns by day 9. Immunofluorescent staining indicated that these cells showed elongated nuclei, enhanced adhesion (vinculin adhesion plaques) and a well‐aligned cytoskeleton (actin stress fibres). This work suggests that this type of spraying may provide a route for the production of nanoscale features on implants for biomedical applications. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Vascular cell viability on polyvinyl alcohol hydrogels modified with water‐soluble and ‐insoluble chitosan
Authors: Mathews D. T. , Birney Y. A. , Cahill P. A. , McGuinness G. B. 
Published: August 2007

AbstractPolyvinyl alcohol (PVA) hydrogels blended with chitosan or other biological macromolecules have shown promise for cell culture and tissue engineering. This study investigates the attachment and growth of bovine aortic endothelial (BAEC) and smooth muscle cells (BASMC) on the PVA hydrogels modified with water soluble and water insoluble chitosan. Cell adhesion on the surface of the membranes was examined by phase constrast microscopy while cell morphologies were studied using immunocytochemistry staining with EC and SMC specific biomarkers (F‐actin and α actin respectively). Cells cultured on 6% PVA, 0.4% chitosan (water soluble and insoluble) hydrogel membranes displayed excellent adhesion and spreading characteristics, in addition to negligible cell structural morphological changes in comparison to a polystyrene control. Similar vascular cell adhesion features were apparent on PVA membranes blended with water‐soluble and ‐insoluble chitosan. Fluorescent activated cell sorter (FACS) analysis was used to determine BAEC and BASMC proliferation and cell viability. Apoptotic levels in BAEC after 7 days were 12.8% ± 2.5% on the PVA‐ chitosan WS‐1 membrane and 10.1% ± 1.5% on the control well (n = 3) while comparable results were also noted for BASMC. Equivalent proliferative activity was apparent for BAEC on the control and PVA‐chitosan membrane after 7 days, while BASMC showed increased proliferative activity on the membranes. These results indicate that the PVA‐chitosan blended hydrogel membranes show promise for cell culture and tissue engineering applications. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2008
N3‐Substituted thymidine analogues III: radiosynthesis of N3‐[(4‐[18F]fluoromethyl‐phenyl)butyl]thymidine ([18F]‐FMPBT) and N3‐[(4‐[18F]fluoromethyl‐phenyl)pentyl] thymidine ([18F]‐FMPPT) for PET
Authors: Ghosh Pradip , Gelovani Juri G. , Alauddin Mian M. 
Published: August 2007

AbstractRadiosyntheses of two N3‐substituted thymidine analogues, N3‐[(4[18F]fluoromethyl‐phenyl)butyl]thymidine ([18F]‐FMPBT) and N3‐[(4[18F]fluoromethyl‐phenyl)pentyl]thymidine ([18F]‐FMPPT), are reported. The precursor compounds 9 and 10 were synthesized in six steps and the standard compounds 13 and 14 were synthesized from these precursors. For radiosynthesis, compounds 9 and 10 were fluorinated with n‐Bu4N[18F] to produce [18F]‐11 and [18F]‐12, which by acid hydrolysis yielded [18F]‐13 and [18F]‐14, respectively. The crude products were purified by high‐performance liquid chromatography to obtain [18F]‐FMPBT and [18F]‐FMPPT. The average decay‐corrected radiochemical yield for [18F]‐13 was 15% in five runs, and that for [18F]‐14 was 10% in four runs. The radiochemical purity was >99% and the specific activity was >74 GBq/µmol at the end of synthesis. The synthesis time was 80–90 min from the end of bombardment. Copyright © 2007 John Wiley & Sons, Ltd.
“Soluble” adenylyl cyclase‐generated cyclic adenosine monophosphate promotes fast migration in PC12 cells
Authors: Young Jennifer J. , Mehdi Amna , Stohl Lori L. , Levin Lonny R. , Buck Jochen , Wagner John A. , Stessin Alexander M. 
Published: August 2007

AbstractIn a model for neuronal movement, PC12 cells undergo fast migration in response to nerve growth factor (NGF) and phorbol ester (PMA). We previously showed that NGF increases intracellular cAMP via activation of soluble adenylyl cyclase (sAC). In this report, we demonstrate that sAC activation is an essential component of NGF‐ + PMA‐induced fast migration in PC12 cells. Interestingly, PMA also raises intracellular cAMP but does so by stimulating transmembrane adenylyl cyclases (tmAC); however, this tmAC‐generated cAMP does not contribute to fast migration. Therefore, cells must possess independent pools of cAMP capable of modulating distinct functions. © 2007 Wiley‐Liss, Inc.
Temperature‐dependent neuronal regulation of arterial blood flow in rat cranial dura mater
Authors: Holom Vigdis H. , Messlinger Karl , Fischer Michael J.M. 
Published: August 2007

AbstractSeveral endogenous factors such as calcitonin gene‐related peptide (CGRP), nitric oxide, and histamine have been found to affect meningeal blood flow. A possible regulation of meningeal blood flow by thermosensitive neurons has not been examined so far. We monitored meningeal arterial blood flow with laser Doppler flowmetry in anesthetized rats. A vortex thermode was used to control the temperature of the exposed dura mater. After fast heating from 36°C to 45°C, meningeal blood flow increased slowly within 5 min. Immediately after fast cooling to 36°C, the flow transiently increased before it returned to the initial basal level. After the application of lidocaine onto the dura mater, the heating‐induced flow increase was greater and the transient cooling‐induced flow increase was reduced, indicating the involvement of neuronal mechanisms. Furthermore, after topical application of phenylephrine, the cooling‐induced response was increased, and following topical application of phentolamine the heating‐induced flow increase was higher. The flow changes evoked by thermal stimulation were unaffected by high concentrations of 1) cimetidine, 2) a vasoactive intestinal polypeptide antagonist and the CGRP receptor antagonists, 3)CGRP8–37, and 4) BIBN4096BS. We conclude that activation of temperature‐sensitive meningeal afferents can regulate the dura mater blood flow by a sympathetic reflex. © 2007 Wiley‐Liss, Inc.
Testate amoebae as proxies for mean annual water‐table depth in Sphagnum‐dominated peatlands of North America
Authors: Booth Robert K. 
Published: August 2007

AbstractPeatland‐inhabiting testate amoebae are sensitive indicators of substrate‐moisture conditions and have increasingly been used in palaeohydrological studies. However, to improve accuracy of testate‐amoeba‐based hydrological inferences, baseline ecological data on rare taxa, a larger geographic network of calibration sites, and incorporation of long‐term estimates of water‐table depth are needed. Species–environment relationships at 369 sites from 31 peatlands in eastern North America were investigated. Long‐term estimates of water‐table depth were obtained using the method of polyvinyl (PVC) tape‐discolouration. Transfer functions were developed using a variety of models, and validated through jackknifing techniques and with an independent dataset where water‐table depths were directly measured throughout the growing season. Results indicate that mean annual water‐table depth can be inferred from testate amoeba assemblages with a mean error of 6 to 8 cm, although there is a slight systematic bias. All transfer function models performed similarly and produced similar reconstructions on a fossil sequence. In a preliminary effort towards development of a comprehensive North American calibration dataset, data from this study were combined with previous studies in Michigan and the Rocky Mountains (n = 650). This combined dataset had slightly larger mean errors of prediction (8–9 cm) but includes data for several rare taxa. Copyright © 2007 John Wiley & Sons, Ltd.
Pasteurized autograft‐prosthesis composite for reconstruction of proximal tibia in 13 sarcoma patients.
Authors: Jeon Dae‐Geun , Kim Min Suk , Cho Wan Hyeong , Song Won Seok , Lee Soo‐Yong 
Published: August 2007

AbstractBackgroundThe purpose of this study is to ascertain the survival of the pasteurized autograft‐prosthesis composite and functional outcome of this procedure, and to evaluate the complications including nonunion, infection, loosening, bony resorption, and fracture.MethodsWe retrospectively reviewed 13 proximal tibial sarcoma patients who underwent tibia reconstructions with using a pasteurized autograft‐prosthesis between 1993 and 2003.ResultsFour patients underwent removal of the composite with a minimum follow‐up of 11 months (average: 43 months, range: 11–75 months). The survival rate of the 13 composites, as calculated by the Kaplan–Meier method, was 76.9% at 5 years. The primary cause of removing the composite was infection in three patients and loosening in one patient. The average MSTS functional score of 11 patients was 23.6 ± 3.3 (79%). Nonunion was identified in four patients, while infection developed in three patients. Loosening of the stem and resorption of the pasteurized bone was detected in one case each. No patient developed fracture of autograft.ConclusionsOur data suggest that the pasteurized autograft‐prosthesis has comparable functional outcome and complication rates as other methods, such as endoprosthesis and allograft‐prosthetic composite and it offers a reconstructive option for surgeons who do not have access to large allograft banks. J. Surg. Oncol. 2007;96:590–597. © 2007 Wiley‐Liss, Inc.
Residual disease after re‐excision for tumour‐positive surgical margins in both ductal carcinoma in situ and invasive carcinoma of the breast: The effect of time
Authors: van der Velden A.P. Schouten , Van de Vrande Simon L.B. , Boetes Carla , Bult Peter , Wobbes Theo 
Published: August 2007

AbstractBackground and ObjectivesTo assess the effect of time on finding residual breast cancer in re‐excision specimens after non‐radical breast‐conserving surgery for both DCIS and invasive breast carcinoma.Methods315 breast‐conserving surgical procedures with tumour‐positive margins were retrospectively reviewed. The significance of association between the presence of finding residual tumour in the re‐excision specimen and mean time interval was calculated with Student's t‐test. A multivariate logistic regression model was used to assess the independent relative risk of time on presence of residual tumour.ResultsResidual tumour was found in 240 (76.2%) of the re‐excision specimens. For primary invasive carcinomas time was a risk‐reducing factor for finding residual disease (OR 0.89, 95% CI 0.82–0.98, P = 0.01). If invasive carcinoma was transected, the absence of residual disease was significantly related with a longer mean time interval (OR 0.98, 95% CI 0.95–0.99, P = 0.04).ConclusionsAn increased time interval between primary surgery and re‐excision for tumour‐positive surgical margins for invasive carcinoma is associated with a decreased incidence of finding residual tumour. This could be explained by inflammatory responses after surgical trauma. For DCIS there was no influence of time on finding residual tumour, which could be explained by a more protective microenvironment of DCIS or re‐growth of surviving malignant cells. J. Surg. Oncol. 2007;96:569–574. © 2007 Wiley‐Liss, Inc.
Functional Graft Poly(N‐isopropyl acrylamide)s Using Reversible Addition‐Fragmentation Chain Transfer (RAFT) Polymerisation
Authors: Carter Steven R. , England Richard M. , Hunt Barry J. , Rimmer Stephen 
Published: August 2007

AbstractA series of NIPAM/4‐vinyl benzyl chloride copolymers were substituted with 4(5)‐imidazole dithioic acid or N‐pyrrole dithioic acid to form multi‐functional linear dithioate‐functional polymers, which can be used as macromolecular transfer agents in a controlled radical polymerisation (RAFT) process. The presence of imidazole dithioate or N‐pyrrole dithioate units along the NIPAM copolymer was determined by 1H NMR, which showed broad CH‐imidazole or CH‐N‐pyrrole resonances. Subsequent reaction of these multi‐branch point polymers to produce graft polymers was achieved by reaction with NIPAM in the presence of AIBN. The graft polymers are produced as mixtures containing the desired product and linear polymer. The linear polymer is produced following transfer to the pendant dithioate group. Some of the branched polymers formed from the imidazole dithioate polymers were insoluble in water whilst others were found to be water soluble only in the presence of copper(II) ions. The use of N‐pyrrole dithioate groups was found to substantially increase the solubility of the branched polymers in conventional solvents.magnified image
Synthesis and Self‐Assembly of Brush‐Rod Diblock Copolymers in the Mixed Solvent of THF/H2O
Authors: Cao Hongqing , Lin Weiran , Liu Anhua , Zhang Jie , Wan Xinhua , Zhou Qifeng 
Published: August 2007

AbstractTwo amphiphilic brush‐rod block copolymers, PEGMA37‐b‐MBPS87 and PEGMA37‐b‐MBPS141, were synthesized via ATRP of poly(ethylene glycol)monomethyl ether methacrylate (PEGMA) and (+)‐2,5‐bis[4′‐((S)‐2‐methylbutoxy)phenyl]styrene (MBPS). The self‐assembly of the copolymers in THF/H2O was induced by different methods. Spheres were dominant morphologies of PEGMA37‐b‐MBPS87 regardless of the initial concentration and the rate of water addition. Increase of the length of hydrophobic block, as in PEGMA37‐b‐MBPS141, led to the coexistence of primary spheres, large compound spherical and rod‐like micelles at a slow water addition rate. Injecting water into the THF solution of PEGMA37‐b‐MBPS141 quickly or pouring the THF solution into large amount of water resulted only in the formation of spheres.magnified image
Diminished fatigue at reduced muscle length in human skeletal muscle
Authors: Lee Samuel C. K. , Braim Anthony , Becker Cara N. , Prosser Laura A. , Tokay Ann M. , Binder‐Macleod Stuart A. 
Published: August 2007

AbstractUnderstanding muscle fatigue properties at different muscle lengths is essential to improve electrical stimulation applications in which impaired muscle is activated to produce function or to serve as an orthotic assist. This study examined the effects of muscle length on fatigue in human quadriceps muscle. Twelve healthy subjects were tested at short and long muscle lengths (15° and 90° of knee flexion, respectively) before and after a fatigue‐producing protocol using low‐, high‐, and variable‐frequency testing trains. Greater fatigue was observed at the longer muscle length, supporting the notion that fatigue is largely dependent upon metabolic factors. Fatigue, however, was characterized by greater attenuation of low‐ than high‐frequency responses (i.e., low‐frequency fatigue, LFF) at the long length. This observation, accompanied by the fact that variable‐frequency trains produced greater augmentations in force production than comparable low‐frequency trains at the longer length, suggests that excitation–contraction coupling impairment is also a contributing factor to fatigue and plays a greater role at the more fatigue‐susceptible longer muscle length. Muscle Nerve, 2007
Proteomic analysis of rabbit tear fluid: Defensin levels after an experimental corneal wound are correlated to wound closure
Authors: Zhou Lei , Beuerman Roger W. , Huang Liqun , Barathi Amutha , Foo Yong Hwee , Li Sam F. Y. , Chew Fook Tim , Tan Donald 
Published: August 2007

AbstractThe cornea is the major refracting optical element of the eye and therefore critical for forming a retinal image. The exposed surface of the eye is protected from pathogens by the innate immune system whose components include defensins, naturally occurring peptides with antimicrobial properties, and the physical barrier formed by the outer epithelial layer of the cornea. The proteomic approach has revealed that tear levels of defensins are correlated with the course of healing of an experimental corneal wound. Tears were collected from New Zealand White rabbits prior to (day 0) and daily for 5 days (days 1–5) following a standard unilateral 6 mm diameter corneal epithelial abrasion. Tear protein profiles obtained from wounded and contra‐lateral control eyes were compared using SELDI ProteinChip technology. Peptides and proteins of interest were purified by RP‐HPLC and characterized by nanoESI‐MS/MS. Mass spectra of tears on post‐wound day 1, revealed 13 peaks whose level decreased and five that increased. During wound healing the tear protein profile correlated with wound closure. An important finding was that the levels of rabbit defensins (NP‐1 and NP‐2), which were elevated after wounding returned to normal levels by the time the corneal abrasion healed. Relative quantification of NP‐2 in tear fluid prior to (day 0) and after corneal wounding (days 1– 3) was determined using iTRAQ technology. A corneal wound eliminates the barrier function of innate immunity and puts the cornea at risk from microbial attack until the epithelial cells restore the surface barrier. The increased availability of defensins in the tears during healing suggests that these peptides could protect the cornea from microbial attack during a period of increased vulnerability.
The link between the ionization potential and heat of formation for organic homologous compounds
Authors: Cao Chenzhong 
Published: August 2007

AbstractBased on the relationship between the heat of formation and the change of valence electronic energy in the formation of a compound from its component atoms, and combined with the relationship between the first ionization potential and the average valence electronic energy, the direct link of ionization potential, Ip, with the heat of formation, ΔH0f, was deduced for organic homologous compounds, that is,

where Nve,m is the number of valence electrons in molecule, SVEEx is the sum of valence electronic energy of isolated atoms forming the molecule, the term $(\Sigma {\rm SVEE}_x - \Delta H_{_{\rm f} }^{\rm 0} )$ expresses the initial‐state effect of the molecule, and the symbol Rm represents its final‐state effect (polarizability effect). The above equation was confirmed by the correlations between the ionization potentials and the heat of formation of alkanes, alkenes, monosubstituted alkanes RY (Y = OH, NH2, SH, Cl, Br, and I), in which all the expressions have good correlations with correlation coefficients more than 0.9990. With the obtained correlation equations, the ionization potentials of some monosubstituted alkanes were predicted from their experimental heats of formation. The result provides a new insight into the intercorrelation between the ionization potential and the heat of formation for organic homologous compounds. Copyright © 2007 John Wiley & Sons, Ltd.