bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on the tumor‐promoting activity of polyurethanes: Depletion of inhibitory action of metabolic cooperation on the surface of a polyalkyleneurethane but not a polyetherurethane
Authors: Tsuchiya Toshie , Takahara Atsushi , Cooper Stuart L. , Nakamura Akitada 
Published: May 2005

AbstractMethanol extracts prepared from three polyetherurethanes (PEUs), namely PU4, PU6, and PU8, which were synthesized using 4,4′‐diphenylmethanediisocyanate, poly(tetramethylene oxide), and 1,4‐butanediol, showed an inhibitory action on the gap‐junctional intercellular communication in a V79 metabolic cooperation (MC) test system. However, the inhibitory potentials of methanol extracts did not correlate with the tumorigenic potential of the polyurethanes in 1‐year rat implantation studies. When the MC test was carried out using glass dishes partly coated with low molecular weight PEU, the inhibitory activity was clearly detected on the surface of the polyurethane coating but not on that of the noncoated glass area. The inhibitory activity of the three PEUs investigated using polyurethanecoated dishes correlated with the values of the polyurethane's tumorigenic potential in the rat implantation study. Various polyurethanes containing polybutadiene (PBD), hydrogenated polybutadiene (HPBD), or a fluoropolyether glycol (FPEG) as the soft segment were also tested using coated dishes in the MC assay. The threshold inhibitory response of FPEG–PU was 10‐fold less than that of PU4, and neither PBD–PU nor HPBD–PU showed any inhibition in the MC test system. Both the FPEG and aliphatic soft segment containing polyurethanes decreased, and had minimal influence on the gap junctional intercellular communication. Thus, the tumor‐promoting potential of PBD–PU, HPBD–PU, and FPEG–PU was considered to be lower than those of the PEUs based on these in vitro test results. © 1995 John Wiley & Sons, Inc.
Experimental long‐term study of titanium ions eluted from pure titanium miniplates
Authors: Bessho Kazuhisa , Fujimura Kazuma , Iizuka Tadahiko 
Published: May 2005

AbstractA long‐term study of titanium miniplates, which are in wide clinical use, was conducted to clarify their usefulness as a permanent fixing device. We examined by scanning electron microscopy the surfaces of removed plates and the accumlation of titanium in the organs of Japanese white rabbits. Two years after implantation the titanium plates were only slightly corroded. In addition, marked titanium accumulation was noted in the organs, especially in the lungs. However, the accumulation of titanium in the organs of animals with left distomolar mandibular fracture was highest at 3 months after implantation, and then gradually decreased over 2 years. Titanium miniplates have recently been used clinically in humans and no adverse reactions have yet been reported. The present findings suggest the use of titanium miniplates as permanent fixing devices. © 1995 John Wiley & Sons, Inc.
Biomaterial‐induced dysfunction in the capacity of rabbit alveolar macrophages to kill staphylococcus epidermidis RP12
Authors: Giridhar G. , Myrvik Q. N. , Gristina A. G. 
Published: May 2005

AbstractThe effect of poly(methyl methacrylate) (PMMA), titanium alloy, and silicone discs on the capacity of rabbit alveolar macrophages (AM) to kill RP12 strain of Staphylococcus epidermidis (RP12) was studied in vitro. When freshly harvested AM were preincubated with PMMA discs for 3 h and subsequently assayed for RP12 killing, there was no change in the RP12 killing capacity of AM. However, when AM were incubated with PMMA discs for 6 or 18 h at 37°C in 5% CO2, the RP12 killing capacity of AM was reduced to 15% and 4%, respectively. Preincubation of AM with titanium alloy for 6 h reduced RP12 killing capacity of AM to 30%, and to 21% in 18‐h incubation. Silicone discs did not affect the RP12 killing by AM at 6 h of preincubation, but reduced RP12 killing (35%) by AM when preincubated, for 18 h. Preincubation of AM with PMMA discs for 3 or 6 h did not affect the level of PMA‐elicited oxidative burst of AM as measured by a luminol‐enhanced chemiluminescent assay. Superoxide dismutase, which eliminated the oxidative burst of AM by 90%, did not affect the RP12 killing by AM. © 1995 John Wiley & Sons, Inc.
An improved model for bacterial encrustation studies
Authors: Sarangapani Shantha , Cavedon Katherine , Gage David 
Published: May 2005

AbstractA comparative evaluation of various biomaterials for their resistance to bacterial colonization and encrustation in infecred urine is an important area in urological biomaterials research. This article describes an in vitro dynamic perfusion system that allows four reactors containing 24 1‐in. catheter samples (6 per reactor) to be simultaneously perfused at a constant flow rate by synthetic urine. A common urease‐producing urinary pathogen, Proteus mirabilis, was maintained at a level of 106 colony‐forming units/mL for 7 days in the dynamic perfusion reactors. The pH and bacterial population were monitored every 24 h and the percentage of encrustation on latex and hydrogel‐coated commercial catheter materials gave reproducible results in three different runs, 15.2 ± 3.65% and 13.8 ± 2.58%, respectively. A major issue of inlet clogging due to ascending bacteria or ammonia has been rectified using a dismountable inlet assembly. An incubator coupled with a cooling system allowed accurate temperature maintenance of 37°C in all four reactors. Results from scanning electron microscopy of some latex samples are also presented. © 1995 John Wiley & Sons, Inc.
Degradation of polyetherurethane by subcutaneous implantation into rats. II. Changes of contact angles, infrared spectra, and nuclear magnetic resonance spectra
Authors: Sato Michio , Xi Tingfei , Nakamura Akitada , Kawasaki Yasushi , Umemura Takashi , Tsuda Mitsuhiro , Kurokawa Yuji 
Published: May 2005

AbstractIn vivo degradation of polyetherurethanes (PEUs) was studied using two kinds of PEUs, U‐3 and U‐8, coated on a base film of ethylene/vinyl alcohol copolymer (EVAL). U‐3 is a nonsegmented PEU prepared from 4,4′‐diisocyanato‐diphenylmethane (MDI) and poly(tetramethylene oxide) (PTMO 1000). U‐8 is a segmented PEU prepared from MDI, PTMO 1000, and 1,4‐butanediol. Previous studies of PEUs were conducted using gel permeation chromatography and scanning electron microscopy. In this study, the explanted materials were examined with contact angle measurement, ATR‐FTIR, and nuclear magnetic resonance (NMR) spectroscopies. All data obtained by these methodologies indicate that the PTMO/MDI oligomers diffused to the material surface in the early stage of implantation. Then, the lowmolecular‐weight fraction of the oligomers leached out from the surface to the exudate. Degradation became dominant after 2–4 weeks. In the case of PU‐8, the PTMO fraction decreased approximately 35–40% from the surface at 24 weeks postimplantation. In the case of PU‐3, the loss of coating material (U‐3) on the base film (EVAL) was observed after 10 weeks. The PTMO fraction of the surface U‐3 remained on EVAL at 6 weeks postimplantation, however, it was 64% of the initial material. The molecular weight of the U‐3 remaining on EVAL also decreased. Degradation of U‐3 occurred more rapidly than that of U‐8. The data obtained with our materials were insufficient in determining evidence of oxidative degradation with IR or NMR spectra. © 1995 John Wiley & Sons, Inc.
Analysis of a vinyl pyrrolidone/poly(propylene fumarate) resorbable bone cement
Authors: Gresser Joseph D. , Hsu Shu‐Hwa , Nagaoka Hisanori , Lyons Charles M. , Nieratko Donald P. , Wise Donald L. , Barabino Gilda A. , Trantolo Debra J. 
Published: May 2005

AbstractA resorbable bone cement was formulated from N‐vinyl‐2‐pyrrolidinone (VP), the unsaturated polyester poly(propylene fumarate) (PPF), and the inorganic filler tribasic calcium phosphate (hydroxy apatite). Cure, initiated by benzoyl peroxide and accelerated by N,N‐dimethyl‐p‐toluidine, resulted in the formation of VP crosslinks between polyester chains. During cure the cement hardened from a viscous moldable putty to a rigid structure with a shore D hardness of 50–60. The purpose of this study was to determine the fractions of PPF and VP incorporated into the crosslinked structure. Dissolution of the cured cement in water followed by extraction of the residue in tetrahydrofuran indicated that over 90% of the PPF was crosslinked over the range of PPF/VP ratios explored, but that the fraction of VP used in formation of crosslinks depended linearly on the PPF/VP ratio. Kinetic analysis of these data suggests that k′pp/kpf (the reactivity ratio) was ∼2.0 where k′pp is the rate constant for the addition of VP radical to VP monomer leading to formation of poly(vinyl pyrrolidone), and kpf is for the addition of VP radical to PPF unsaturation. © 1995 John Wiley & Sons, Inc.
Atomic force microscopy of conditioning agents on dentin
Authors: Marshall G. W. , Balooch M. , Kinney J. H. , Marshall S. J. 
Published: May 2005

AbstractDentin conditioners provide a microporous surface for penetration by bonding agents. This study used an atomic force microscope (AFM) to examine the initial steps in the conditioning process of dentin using three demineralizing agents, 0.5 M EDTA, and dilute solutions of phosphoric (3mM, 6mM) and citric (5 mM) acids, in order to establish the relationships between demineralization and changes in surface morphology. Polished dentin disks had a 10‐nm‐thick gold pattern applied which served as a height reference. Samples(n = 3/agent) were examined at baseline and at 2‐s intervals for up to 120 s for each agent. EDTA (0.5 M) was used as received; other conditioners were diluted to slow the rates of demineralization for detailed study. The surfaces of the peritubular and intertubular regions were altered differently. Initially subsidence rates were equal and linear, but after a 100‐nm depth change the intertubular rates decreased. For phosphoric acid and citric acid, the movement of the intertubular surface was uniform and the surfaces remained smooth. However, the intertubular surfaces were rough for the EDTA treatment. The surface subsidence reached a plateau after a depth change of about 0.5μm, which resulted from a limit to the contraction of the demineralized and hydrated collagen scaffold. © 1995 John Wiley & Sons, Inc.
Bonding capacity in bone of HIP‐processed HA‐coated titanium: Mechanical and histological investigations
Authors: Wie H. , Herø H. , Solheim T. , Kleven E. , Rørvik A. M. , Haanæs H. R. 
Published: May 2005

AbstractThe main problems using plasma‐sprayed hydroxyapatite (HA) as a coating material on metallic implants are its porosity, low fatigue strength, and weak adherence to the metallic substrate. To overcome these problems a new technique using hot isostatic pressing (HIP) has been developed for producing HA‐coated titanium (Ti) implants. Specimens produced at a maximum temperature of 850°C and a maximum pressure of 720 bar displayed a dense, glassy, 25‐μm thick coating with small amounts of porosity and a mean surface roughness of 0.7μm, as compared with 1.6 μm for sandblasted Ti. Twenty conical HA‐coated (720 and 100 bar pressure) and 10 noncoated Ti implants were inserted through the cortex of the lower margin of the mandibles of sheep and allowed to heal for 60 days. Push‐out tests for implants processed at 720 bar pressure showed substantially higher bone/implant bonding values than for sandblasted Ti implants. Histological studies indicated a direct contact and probably chemical bonding between bone tissue and the HA coatings. The area of contact was almost 3 times as large as for the Ti implants. The adherence of the 100‐bar coating to the Ti surface was inferior to the 720‐bar coating, as shown by the loosening of the coatings in several areas. © 1995 John Wiley & Sons, Inc.
Fibroblast adhesion onto methyl–silica gradients with and without preadsorbed protein
Authors: Williams R. L. , Hunt J. A. , Tengvall P. 
Published: May 2005

AbstractThis study was designed to evaluate the interfacial interactions between proteins and cells and a model surface which varied in its surface energy. The adsorption of proteins from single and binary solutions was studied using ellipsometry and the adhesion and spreading of L929 fibroblasts has been quantified using image analysis. The results demonstrated that after 24 h incubation, multilayer adsorbed fibrinogen appeared to produce a surface most conducive to cell adhesion and spreading on both the hydrophilic and hydrophobic regions of the material. Fibronectin on its own did not produce an optimal surface for cell spreading. Albumin produced a suitable surface for cell spreading on the hydrophilic part of the surface, but created a highly unsuitable surface on the hydrophobic region of the specimens. Competition between proteins for adsorption to the surface and changes in protein conformation was evident, particularly on the hydrophobic part of the material, and this was shown to influence cell adhesion and spreading. © 1995 John Wiley & Sons, Inc.
Effect of surface topology on the osseointegration of implant materials in trabecular bone
Authors: Wong M. , Eulenberger J. , Schenk R. , Hunziker E. 
Published: May 2005

AbstractThe importance of surface topology and implant material composition on osseointegration in trabecular bone was investigated using three commercially used implant materials and surface‐texturing procedures which included blasting, high temperature acid etching, and hydroxyapatite (HA) coating. Surface roughness and spacing parameters were measured for each implant group with a laser interferometric profilometer. Cylindrical implants were press‐fit into trabecular bone sites in the knee of mature miniature pigs. After 12 weeks in situ, osseointegration was evaluated by (1) mechanical pushout tests to measure bone‐implant interface strength and (2) quantitative morphometric measurements of the percent implant surface covered by bone. We found that HA‐coated implants showed superior osseointegration in terms of both pushout failure load and surface coverage by bone measurements. An excellent correlation (r2 = .90) was found between the average roughness of the implant surface and pushout failure load. New methods for altering the local topologic and/or chemical state of the implant surface (i.e., by acid etching) may provide an important new avenue of research for improving the osseointegrative properties of orthopedic materials. © 1995 John Wiley & Sons, Inc.
Development of biomechanical properties and morphogenesis of in vitro tissue engineered cartilage
Authors: Ma P. X. , Schloo B. , Mooney D. , Langer R. 
Published: May 2005

AbstractNeocartilage was engineered by culturing bovine chondrocytes on poly(glycolic acid) (PGA) fibrous nonwoven scaffolds. The biomechanical properties and morphologies of the PGA‐chondrocyte constructs were studied over 12 weeks of in vitro culture. PGA scaffolds without cells lost their mechanical strength and structural integrity between week 2 and week 3 in culture. The thickness of the PGA‐chrondrocyte constructs decreased by 35% during the first 3 weeks, but the thickness increased from week 3 to week 9 to a thickness 42% higher than that of the starting scaffolds, which was then maintained. Safranin O staining of PGA‐chondrocyte constructs revealed increasing proteoglycan formation over time. The compressive modules of PGA‐chondrocyte constructs increased with in vitro culture time, and reached the same order of magnitude as that of normal bovine cartilage at week 9. The aggregate modulus of the PGA‐chondrocyte constructs decreased by 57% over the first 2 weeks but then increased, reaching the same order of magnitude as normal bovine cartilage at week 12. The apparent permeability of the PGA‐chondrocyte constructs, which was initially four orders of magnitude above that of normal cartilage, decreased between weeks 1 and 3 and thereafter remained the same order of magnitude as that measured for normal cartilage. © 1995 John Wiley & Sons, Inc.
Three‐dimensional structures of the central regulatory proteins of the bacterial phosphotransferase system, HPr and enzyme IIAglc
Authors: Chen Y. , Fairbrother W. J. , Wright P. E. 
Published: May 2005

AbstractEnzyme IIA and HPr are central regulatory proteins of the bacterial phosphoenolpyruvate:sugar phosphotransferase (PTS) system. Three‐dimensional structures of the glucose enzyme IIA domain (IIAglc) and HPr of Bacillus subtilis and Escherichia coli have been studied by both X‐ray crystallography and Nuclear Magnetic Resonance (NMR) Spectroscopy. Phosphorylation of HPr of B. subtilis and IIAglc of E. coli have also been characterized by NMR spectroscopy. In addition, the binding interfaces of B. subtilis HPr and IIAglc have been identified from backbone chemical shift changes. This paper reviews these recent advances in the understanding of the three‐dimensional structures of HPr and IIAglc and their interaction with each other. © 1993 Wiley‐Liss, Inc.
Acidic fibroblast growth factor gene 5′ non‐coding exon and flanking region from hamster DDT1 cells: Identification of the promoter region and transcriptional regulation by testosterone and aFGF protein
Authors: Hall Jeffrey A. , Harris Marie A. , Intres Richard , Harris Stephen E. 
Published: May 2005

AbstractSelected clones of Syrian hamster DDT1‐MF2 cells are responsive to testosterone for growth. Heparin binding growth factor 1 (HBGF‐1) or acidic fibroblast growth factor (aFGF) can replace testosterone (T) in the stimulation of growth in these cells. This phenomena is correlated with testosterone's ability to elevate aFGF mRNA two‐ to threefold in DDT1 cells. To better understand the possible mechanisms of regulation of aFGF mRNA by steroids and other growth factors, we isolated the aFGF 5′ non‐coding exon and its flanking region from a EMBL3 DDT1 genomic library, using a 5′ non‐coding exon 69 bp DDT1 aFGF cDNA probe. Clones spanning 30 kb of genomic DNA were isolated. After restriction mapping and DNA sequence analysis, the clones were shown to contain all of the 5′ non‐coding exon included in the cDNA and approximately 10 kb of 5′ flanking region. RNase protection and primer extension assays confirmed that the 5′ non‐coding exon is included in the DDT1 aFGF mRNA and that a major transcription start site is approximately 136 bp upstream of the 5′ non‐coding splice junction of this exon. The 5′ flanking region DNA was inserted into pBLCAT3 reporter gene and transfected into DDT1 cells. Chloramphenicol acetyltransferase (CAT) assays demonstrated that there are promoter elements in the −1645/−392 and −392/+131 regions of the aFGF gene in the context of DDT1 cells. NIH 3T3 cells, on the other hand, show no CAT activity with these aFGF‐CAT plasmids. CAT assays also demonstrated that addition of testosterone (T) or aFGF to DDT1 cells increased CAT activity threefold. This activity was mapped to −1645 to −4 bp region of this DDT1 aFGF gene promoter. © 1993 Wiley‐Liss, Inc.
Evolution of women's trauma‐integrated services at the Substance Abuse and Mental Health Services Administration
Authors: Salasin Susan E. 
Published: May 2005

AbstractIn this article a historical overview of the evolution of the Women's Trauma Integrated Services model at the Substance Abuse and Mental Health Services Administration (SAMHSA) is presented. Milestones in women's services policy development at SAMHSA (1992–1998) and in trauma treatment development for four different trauma populations (1960–1998) are discussed. SAMHSA's 5‐year Women, Co‐Occurring Disorders and Violence Study (1998–2003) is described, and the rationales for a number of basic decisions about the study design are presented. New knowledge application initiatives and plans at SAMHSA to further develop the Women's Trauma Integrated Services Model are outlined. © 2005 Wiley Periodicals, Inc. J Comm Psychol 33: 379–393, 2005.
Characteristics of women engaged in treatment for trauma and co‐occurring disorders: Findings from a national multisite study
Authors: Becker Marion A. , Noether Chanson D. , Larson Mary Jo , Gatz Margaret , Brown Vivian , Heckman Jennifer P. , Giard Julienne 
Published: May 2005

AbstractUsing data from a common cross‐site protocol administered at study enrollment, in this article we examine key characteristics of 2,729 participants in the Women, Co‐Occurring Disorders and Violence Study (WCDVS), including demographics, physical health, mental health, substance abuse, trauma experiences, parenting status, and past history of service use. These data are important because they represent the first federal initiative that addresses the significant lack of appropriate services for women with co‐occurring substance use and mental health disorders who have experienced trauma. Study findings reveal a very vulnerable population with extensive histories of abuse and substantial physical and mental health service needs. Data suggest a pressing need for increased availability of physical and mental health services capable of serving the complex needs of women with co‐occurring disorders and histories of interpersonal violence (physical and/or sexual abuse). Equally important are funding strategies to support needed services. © 2005 Wiley Periodicals, Inc. J Comm Psychol 33: 429–443, 2005.
Trauma‐informed or trauma‐denied: Principles and implementation of trauma‐informed services for women
Authors: Elliott Denise E. , Bjelajac Paula , Fallot Roger D. , Markoff Laurie S. , Reed Beth Glover 
Published: May 2005

AbstractIn this article, we attempt to bridge the gap between practice (service delivery) and philosophy (trauma theory, empowerment, and relational theory). Specifically, we identify 10 principles that define trauma‐informed service, discuss the need for this type of service, and give some characteristics of trauma‐informed services in eight different human service areas. The areas include outreach and engagement, screening and assessment, resource coordination and advocacy, crisis intervention, mental health and substance abuse services, trauma‐specific services, parenting support, and healthcare. We draw upon the experiences of the nine sites involved in the Substance Abuse and Mental Health Service Administration's (SAMHSA) 5‐year grant project, Women, Co‐occurring Disorders and Violence Study (WCDVS), and include the recommendation that consumers be integrated into the design and evaluation of services. © 2005 Wiley Periodicals, Inc. J Comm Psychol 33: 461–477, 2005.
Determination of volatile carboxylic acids in animal wastes by (GC)2 of their benzyl esters
Authors: Monseur X. , Walravens J. , Dourte P. , Termonia M. 
Published: May 2005

AbstractThe C1 ‐C6 fatty acids present in various types of heterogeneous animal wastes were isolated by steam distillation and determined as benzyl esters by high resolution gas chromatography. Glass capillary columns, deactivated with barium carbonate and coated with UCON HB 5100, allowed the analysis of benzyl formate, acetate, propionate, isobutyrate, butyrate, isovalerate, valerate, and caproate in less than 20 minutes. Recovery tests, performed on more than 50 different samples, indicated a benzylation yield and an overall efficiency higher than 99%, with a standard deviation of 2.6% (C5) to 6.0% (C1). The absolute detection limit ranged from 0.3 picomole (caproic acid) to 1.0 picomole (formic acid).