bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of dentin sialophosphoprotein in human prostate cancer and its correlation with tumor aggressiveness
Authors: Chaplet Michaël , Waltregny David , Detry Cédric , Fisher Larry W. , Castronovo Vincent , Bellahcène Akeila 
Published: August 2005

AbstractRecent studies have demonstrated that two SIBLING family members, bone sialoprotein (BSP) and osteopontin (OPN), are overexpressed in human prostate cancer. The expression of these proteins is associated with the acquisition of a metastatic phenotype by cancer cells and a poor prognosis for the patient. Dentin sialophosphoprotein (DSPP) shares several structural and genetic features with OPN and BSP. The presence of DSPP has been recently established in salivary glands, indicating that its expression is not restricted to mineralized tissues. However, its potential expression in human tumors has not been addressed yet. In this study, we sought to evaluate the expression of DSPP in human prostate cancer. Immunohistochemistry was performed on 69 prostate cancer specimens using LFMb‐21 anti‐DSPP monoclonal antibody. All of the prostate cancer lesions examined expressed detectable levels of DSPP, as compared with no or low level of expression in adjacent normal glands (p < 0.0001). High grade prostatic intraepithelial neoplasia (HGPIN) glands generally displayed DSPP expression levels that were similar to those found in neighboring cancer glands. DSPP expression was significantly associated with the pathological stage (p = 0.0087) and the Gleason score (p = 0.0176) of the tumors. Western Blot was performed on 5 representative prostate tumor extracts and 3 prostatic tumor cell lines (PC3, LNCaP and DU145). All tumor extracts and cell lines analyzed have been found to express DSPP. In addition, in situ hybridization was used to assess the presence of DSPP mRNA. DSPP was detected at the RNA level in both HGPIN and tumoral glands. This study shows for the first time that DSPP is ectopically expressed in human prostate cancer. The expression of this SIBLING protein strongly correlates with conventional histopathological prognostic indicators of prostate cancer progression. © 2005 Wiley‐Liss, Inc.
Aberrant promoter methylation of multiple genes during multistep pathogenesis of colorectal cancers
Authors: Takahashi Takao , Shigematsu Hisayuki , Shivapurkar Narayan , Reddy Jyotsna , Zheng Yingye , Feng Ziding , Suzuki Makoto , Nomura Masaharu , Augustus Meena , Yin Jing , Meltzer Stephen J. , Gazdar Adi F. 
Published: August 2005

AbstractAberrant methylation of 5′gene promoter regions associated with gene silencing is an epigenetic phenomenon responsible for silencing of tumor suppressor genes in many cancer types. The aims of our study were to study the role of methylation of a large panel of genes during multistage pathogenesis and to correlate our findings with patient age and other clinico‐pathological features. We investigated the aberrant promoter methylation profile of 19 genes in 92 colorectal cancers (CRCs) and corresponding nonmalignant epithelia (NME) (n = 57), and selected 15 genes for studying 26 colorectal adenomas (CAs). On the Basis of our results, the genes could be divided into 3 groups. Group 1 consisted of 13 genes whose methylation was tumor‐specific. For 8 of these genes, the methylation frequencies in CAs were similar to those of CRCs, but significantly different from the frequencies in NME. Group 2, consisting of 2 genes demonstrating little or no methylation, were present in any sample type. In Group 3, consisting of 4 genes, relatively frequent methylation was present in both CRCs and NME, and the differences between these specimen types were not significant. Methylation of Group 1 genes were tightly correlated with each other, and these genes demonstrated increased methylation frequencies in CRCs with increasing age. Methylation was not correlated with other clinico‐pathological features. In general, methylation frequencies of CAs were intermediate between CRCs and NME. Our study constitutes the most comprehensive methylation profile of CRCs, demonstrates that methylation commences early during CRC pathogenesis and is an age‐related phenomenon. © 2005 Wiley‐Liss, Inc.
Human fibroblast reactions to standard and electropolished titanium and Ti–6Al–7Nb, and electropolished stainless steel
Authors: Meredith D. Osian , Eschbach Lukas , Wood Mairead A. , Riehle Mathis O. , Curtis Adam S.G. , Richards R. Geoffrey 
Published: August 2005

AbstractStainless steel (SS), titanium (cpTi), and Ti–6Al–7Nb (TAN) are frequently used metals in orthopedic internal fracture fixation. Although reactivity to SS and cpTi are noted in reference, the soft tissue compatibility of TAN has not been comprehensively studied. This study focuses on the in vitro soft tissue compatibility of TAN in comparison to SS and cpTi using a human fibroblast model. The industrial standard surface finishes of these three materials vary considerably in view of their use in similar applications. To distinguish between material parameters of topography and chemistry, we have included electropolished (e.p) counterparts of the standard preparations of cpTi and TAN in the study (standard SS is e.p). All materials were characterized using atomic force microscopy, profilometry, and scanning electron microscopy. Our findings demonstrate that cell morphology and growth rate was similar for SS, and e.p. cpTi and TAN, with cells well spread and forming a confluent monolayer by 10 days. Cell growth on standard cpTi was similar to the electropolished samples; however, they showed a less spread morphology with more filopodia and surface ruffling present. Cell morphology on standard TAN was rounded or elongated and proliferation was inhibited at all time points, with possible cell necrosis by day 10. We found evidence of endocytosis of β‐phase particles originating from the standard TAN surface. We believe that the particle uptake coupled with the characteristic surface topography contribute to the noncytocompatibility of fibroblasts on standard TAN. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Characterization of polymeric poly(ϵ‐caprolactone) injectable implant delivery system for the controlled delivery of contraceptive steroids
Authors: Dasaratha Dhanaraju Magharla , Gopinath Damodaran , Rafiuddin Ahmed Mohamed , Jayakumar Rajadas , Vamsadhara Chandrasekar 
Published: August 2005

AbstractContraceptive steroids levonorgestrel (LNG) and ethinyl estradiol (EE) have been encapsulated with poly(ϵ‐caprolactone) (PCL) microspheres using a w/o/w double emulsion method. The microspheres prepared were smooth and spherical, with a mean size from 8–25 μm. In vitro release profiles of microspheres showed a trend of increasing initially at the first week, and thereafter the release was sustained. At the end of the seventh week LNG/EE from 1:5 and 1:10 PCL microspheres were 60 and 48%, 52 and 46%, respectively. An in vitro degradation study shows that at the 20th week the microspheres maintained the surface integrity. The PCL microspheres showed a triphasic in vivo release profile with an initial burst effect due to the release of the steroid adsorbed on the microsphere surface, a second sustained release phase due to the steroid diffusion through the pores or channels formed in the polymer matrix, and third phase due to polymer bioerodible. Histological examination of PCL microspheres injected intramuscularly into thigh muscle of a rat showed a minimal inflammatory reaction demonstrating that contraceptive steroid‐loaded microspheres were biocompatible. The level of inflammatory cytokines determined by immunostaining for IL‐1α, the tissue response to formulations at the first week was considered mild, whereas at the end of the 20th week the inflammatory response ceased. Thus, this study helped us to evaluate the feasibility of using these microspheres as a long‐acting biodegradable drug delivery system for contraceptive steroids. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
A GPIIb/IIIa bioreactor for specific treatment of immune thrombocytopenic purpura, an autoimmune disease. Preparation, in vitro characterization, and preliminary proof‐of‐concept animal studies
Authors: Emregul Emel , David Allan , Balthasar Joseph P. , Yang Victor C. 
Published: August 2005

AbstractImmune thrombocytopenic purpura (ITP) is an autoimmune disease that affects thousands of Americans each year. The resulting thrombocytopenia, which develops from destruction of platelets (PLT) by anti‐PLT autoantibodies (APAb), is often associated with hemorrhagic complications. Existing therapies are not effective and are associated with significant morbidity. Recently, a new treatment modality using plasmapheresis with a Protein‐A column has shown some clinical promise. Yet, although this method would remove the pathogenic APAb, it would also deplete protective antibodies, thereby weakening the body's self‐defense system. Because about 80% of patients with ITP develop APAb against the GPIIb/IIIa antigens on PLT, a novel approach of attaching a GPIIb/IIIa‐linked bioreactor with an extracorporeal circuit is suggested herein to achieve highly effective/specific APAb removal and overcome shortcomings of plasmapheresis in treating ITP. A hollow fiber‐based bioreactor device was fabricated, and GPIIb/IIIa antigens were immobilized onto the inner lumens of the hollow fibers by using the epichlorohydrin activation method. An optimized bioreactor containing a loading of 1.63 mg GPIIb/IIIa/g fibers and adsorption capacity of 1.9 mg 7E3/g fibers was developed. Preliminary proof‐of‐concept investigation using a 7E3‐induced thrombocytopenic rat model (which mimicked clinical ITP) was carried out. A complete (100%) return of PLT counts to their initial levels was observed in rats within 6 h after the GPIIb/IIIa bioreactor treatment. In addition, a rapid restoration of WBC counts in the treated rats was also found. These preliminary findings shed light of promise of using the GPIIb/IIIa bioreactor approach in achieving highly improved ITP therapy. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Transplantation of chondrocytes seeded on collagen‐based scaffold in cartilage defects in rabbits
Authors: De Franceschi Luciana , Grigolo Brunella , Roseti Livia , Facchini Andrea , Fini Milena , Giavaresi Gianluca , Tschon Matilde , Giardino Roberto 
Published: August 2005

AbstractRecent success in tissue engineering by restoring cartilage defects by transplanting autologous chondrocyte cells on a three‐dimensional scaffold has prompted the improvement of this therapeutic strategy. Here we describe a new approach investigating the healing of rabbit cartilage by means of autologous chondrocytes seeded on a biomaterial made of an equine collagen type I‐based scaffold. Full‐thickness defects were created bilaterally in the weight‐bearing surface of the medial femoral condyle of both femora of New Zealand male rabbits. The wounds were then repaired by using both chondrocytes seeded on the biomaterial and biomaterial alone. Controls were similarly treated but received either no treatment or implants of the delivery substance. Histological examination of the reconstructed tissues at 1, 3, 6, and 12 months after transplantation showed that at 1 and 3 months there was no formation of reconstructed tissue in any of the groups evaluated; after 6 months there was evidence of a newly regenerated tissue with some fibrocartilaginous features only in the group treated with biomaterial‐seeded cells, and at 12 months a more organized tissue was evident in the same group. With regards to the group transplanted with biomaterial alone and the untreated control group, there was no evidence of new tissue production. These results advocate the use of this collagen‐based scaffold for further in vivo studies on large size animals and, finally, in human clinical trials for the treatment of knee cartilage defects. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Supramolecular assemblies of adsorbed collagen affect the adhesion of endothelial cells
Authors: Keresztes Z. , Rouxhet P. G. , Remacle C. , Dupont‐Gillain C. 
Published: August 2005

AbstractThe behavior of endothelial cells (HUVECs) in contact with thin collagen films presenting different supramolecular organizations was investigated. Collagen was adsorbed on polystyrene (PS) and plasma‐oxidized PS (PSox) in conditions ensuring the formation of continuous layers presenting an increasing density of fibrillar structures. Discontinuous collagen layers were also prepared on PS by adsorption followed by dewetting. The morphology of the obtained collagen films was checked by using atomic force microscopy. HUVECs adhesion was evaluated in terms of cell number, cell area, cell shape, and actin structure after 4 h of contact with the prepared collagen layers. In the presence of serum, no adhesion was observed on PS, whereas a substantial adhesion was found on PSox. This is explained by the competition for adsorption, which turns in favor of adhesive proteins secreted by the cells on the hydrophilic PSox, but turns in favor of serum albumin on the hydrophobic PS. The progressive coating of PS by smooth collagen films increased cell adhesion and spreading. However, cell spreading and cytoskeleton organization were adversely affected by the appearance of a high density of collagen fibrillar structures. This latter trend was similarly observed on PSox. On the other hand, HUVECs spreading and cytoskeleton organization were clearly enhanced on discontinuous collagen layers compared with continuous ones. A possible explanation for these observations lies in the modification of exposure and/or spatial distribution of recognition sequences due to spontaneous collagen self‐assembly on fibril formation or to collagen aggregation on dewetting. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Crosslinking of collagen with dendrimers
Authors: Duan X. , Sheardown H. 
Published: August 2005

AbstractPolypropyleneimine octaamine dendrimers were studied as an alternative means of generating highly crosslinked collagen. Crosslinking was effected by using the water‐soluble carbodiimide 1‐ethyl‐3‐(3‐dimethyl aminopropyl) carbodiimide hydrochloride (EDC). The multifunctional dendrimers were introduced as novel crosslinkers after the activation of the carboxylic acid groups of glutamic and aspartic acid residues in collagen. The conventional crosslinker glutaraldehyde was used as a control. EDC, itself an alternative crosslinker, which forms zero‐length crosslinks by directly covalently binding collagen molecules, as well as a low molecular weight diamine and a low molecular weight triamine, were also studied. All of the resultant gels were freeze‐dried to obtain sponges for characterization. Water uptake of the gels decreased from 90% to 60% after dendrimer crosslinking compared with EDC crosslinking. DSC results showed an increase of denaturation temperature of collagen after crosslinking with the various methods. The generation 2 and 3 dendrimer‐crosslinked collagen samples had the highest denaturation temperature, at up to 90°C compared with 50°C in the uncrosslinked collagen control. The dendrimer‐crosslinked collagen also showed unique thermal characteristics, with multiple denaturation temperature peaks in contrast to the single peak noted with the other crosslinked collagens. This is thought to be due to the heterogeneous nature of dendrimer crosslinking. Collagenase results revealed that the dendrimer‐crosslinked collagen had a comparative resistance to proteolysis to glutaraldehyde‐crosslinked collagen. Measurement of activated carboxylic acid groups before and after crosslinking indicated that 40–70% of the activated carboxylic acid was consumed during crosslinking with dendrimers. The results suggest that dendrimer crosslinking of collagen produces stable gels. The presence of a large number of excess amine groups in the dendrimers may also be useful for subsequent modification with biologically relevant groups. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
On the feasibility of phosphate glass and hydroxyapatite engineered coating on titanium
Authors: Kim Hae‐Won , Lee Eun‐Jung , Jun In‐Kook , Kim Hyoun‐Ee 
Published: August 2005

AbstractIn this report, bioactive calcium phosphate (CaP) coatings were produced on titanium (Ti) by using phosphate‐based glass (P‐glass) and hydroxyapatite (HA), and their feasibility for hard tissue applications was addressed in vitro. P‐glass and HA composite slurries were coated on Ti under mild heat treatment conditions to form a porous thick layer, and then the micropores were filled in with an HA sol–gel precursor to produce a dense layer. The resultant coating product was composed of HA and calcium phosphate glass ceramics, such as tricalcium phosphate (TCP) and calcium pyrophosphate (CPP). The coating layer had a thickness of approximately 30–40 μm and adhered to the Ti substrate tightly. The adhesion strength of the coating layer on Ti was as high as 30–33 MPa. The human osteoblastic cells cultured on the coatings produced by the combined method attached and proliferated favorably. Moreover, the cells on the coatings expressed significantly higher alkaline phosphatase activity than those on pure Ti, suggesting the stimulation of the osteoblastic activity on the coatings. On the basis of these observations, the engineered CaP coating layer is considered to be potentially applicable as a hard tissue‐coating system on Ti‐based implants. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
The phase state of NiTi implant material affects osteoclastic attachment
Authors: Muhonen V. , Heikkinen R. , Danilov A. , Jämsä T. , Ilvesaro J. , Tuukkanen J. 
Published: August 2005

AbstractIn the present work, the responses of mature osteoclasts cultured on austenite and martensite phases of NiTi shape memory implant material were studied. We used the sensitivity of osteoclasts to the underlying substrate and actin ring formation as an indicator of the adequacy of the implant surface. The results showed osteoclasts with actin ring on both NiTi phases. However, significantly more osteoclasts were present on the austenitic NiTi than on the martensitic NiTi. We also analyzed the surface free energy of the samples but found no significant difference between austenite and martensite phases. The results revealed that osteoclasts tolerated well the austenite phase of NiTi. The chemically identical martensitic NiTi was not as well tolerated by osteoclasts (e.g., indicated by diminished actin ring formation). This leads to the conclusion that certain physical properties specific to the martensitic NiTi have an adverse effect to the surviving of osteoclasts on this NiTi phase. These results confirm that mature, authentic osteoclasts can act as cell probes in experiments concerning aspects of biocompatibility of bone implant materials. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Novel approach for quantification of porosity for biomaterial implants using microcomputed tomography (μCT)
Authors: Hiu‐Yan Yeung , Ling Qin , Kwong‐Man Lee , Ming Zhang , Kwok‐Sui Leung , Chun‐yiu Cheng Jack 
Published: August 2005

AbstractPorous bioceramics have been widely investigated in orthopaedic tissue engineering. Attention has been given to manufacturing of a porous bioceramic that mimics the trabecular bone structure for proper bone regeneration. With the advance of biomedical imaging through microcomputed tomography (μCT), this study attempted to quantify the pore structure of different bioceramics. Two bioceramic blocks (BSC and ChronOS) were synthesized by two methods. The specification claimed the porosity of the bioceramic ranged from 40% to 70%. Six blocks of each bioceramic were evaluated by conventional water immersion method and μCT. The pore size and connectivity were evaluated with standardized protocols. By the water immersion method, the porosity of BSC and ChronOS was 60.4% and 74.7%, respectively. The three‐dimensional results of μCT showed that BSC porosity was 26.2% and ChronOS was 60.0%. The pore connectivity was evaluated to be 2.6 for BSC and 39.7 for ChronOS. ChronOS had functional pores with 200 μm to 400 μm in diameter (87.8% ± 0.5%), which is significantly more than 52.8% ± 11.5% of pores in BSC (p < 0.05). Providing information on the functional pores objectively, the μCT evaluation serves as a good standard for specification of the bioceramic‐related implants. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Benchmarking approximate density functional theory. I. s/d excitation energies in 3d transition metal cations
Authors: Holthausen Max C. 
Published: August 2005

AbstractThe performance of a number of different implementations of density functional theory (DFT) for predicting the s/d interconfigurational energies of the 3d transition metal cations is investigated. Systematic comparisons of computed results with experimental data indicate that gradient corrected correlation functionals, like the LYP GGA, efficiently correct the flaws of the LDA, but reveal shortcomings in the treatment of exchange by currently available GGAs. The admixture of exact exchange in hybrid functionals eventually leads to largely reduced errors. Several basis sets available for the 3d elements are tested in combination with the B3LYP functional. Finally, the influence of variations of the admixture of exact exchange is systematically tested. The results reveal that computed s/d excitation energies obtained for the individual ions depend in markedly different ways on the amount of exact exchange admixture and that there is no single optimal and transferable exchange parameter to create a hybrid functional that yields improved results for all ions alike. Several of the recently devised functionals perform as good as or slightly better than the B3LYP functional in the present study. But given the fact that the B3LYP functional has been identified as the most successful DFT method in an overwhelming number of systematic investigations in very many areas of chemical research, there is no persuasive motivation to recommend its replacement by one of the other functionals, as much less is known about their robustness. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 1505–1518, 2005
Detailed considerations for a balanced and broadly applicable force field: A study of substituted benzenes modeled with OPLS‐AA
Authors: Price Daniel J. , Brooks Charles L. 
Published: August 2005

AbstractModern classical force fields have been traditionally parameterized by attempting to maximize agreement to any number of experimental and/or quantum mechanical target properties. As these force fields are pushed towards obtaining quantitative estimates of often subtle energetic differences, stringent and consistent parameterization criteria, particularly in regard to charge distributions, are required to ensure that systematic errors cancel, that parameters are transferable between molecules, and that performance does not significantly deteriorate when using more approximate methods, such as with continuum solvent models. Relative free energies of hydration are presented here for 40 mono‐ and disubstituted benzenes modeled with the OPLS‐AA force field; heats of vaporization and pure liquid densities at standard conditions are presented when experimental data is available. Overall agreement between OPLS‐AA and experiment is remarkable (average error = 0.5 kcal/mol for ΔΔGhydration, 1.0 kcal/mol for ΔH, 0.02 g/mL for densities), yet several functional groups are identified as having consistent and correctable errors (alkyl‐, nitro‐, and thiobenzenes). Relative free energies of hydration obtained with rigorous free energy perturbations using explicit solvent are also compared with energies from minimizations using a generalized Born model (GB). There is high correlation between these estimates (R = 0.99), and as demonstrated here, reparameterization of the aforementioned groups can be guided with rapid GB calculations. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 1529–1541, 2005