bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adhesion of amorphous calcium phosphate composites bonded to dentin: A study in failure modality
Authors: O'Donnell Justin N. R. , Schumacher Gary E. , Antonucci Joseph M. , Skrtic Drago 
Published: December 2008

AbstractAims:As a bioactive filler capable of remineralizing tooth structures, the main disadvantage of as‐made amorphous calcium phosphate (am‐ACP) are its large agglomerates. The objective of this study was to mill ACP, and compare the adhesive strength with dentin, work to fracture, and failure modes of both groups to glass‐filled composites and one commercial compomer after 24 h, 1 week, 1, 3, and 6 months of exposure to simulated saliva solution (SLS). Flat dentin surfaces were acid‐etched, primed, and photopolymerized. Composites were applied, photo‐cured, and debonded in shear. The resin used in each composite was identical: ethoxylated bisphenol A dimethacrylate, triethylene glycol dimethacrylate, 2‐hydroxyethyl methacrylate, and methacryloxyethyl phthalate. Fillers consisted of am‐ACP and milled ACP (m‐ACP), and a strontium‐containing glass (Sr‐glass) at respective mass fractions of (40, 60, and 75%).Findings:Ninety percent of the fracture surfaces in this study showed adhesive failure, with most of these occurring at the dentin/primer interface. Fifty‐two percent of failures after 24‐h immersion occurred at the primer/composite interface. After 6 months of SLS exposure, 80% of specimens failed at the dentin/primer interface, with a 42% overall reduction in bond strength.Conclusions:Milled ACP composites showed initial mechanical advantages over am‐ACP composites and the compomer, and produced a higher incidence of a failure mode consistent with stronger adhesion. Evidence is provided which suggests that milled ACP composites may offer enhanced potential in clinical bonding applications. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Accelerated aqueous aging simulation of in vivo oxidation for gamma‐sterilized UHMWPE
Authors: Kurtz Steven M. , Siskey Ryan L. , Dumbleton John 
Published: December 2008

AbstractIn vivo oxidation of gamma air‐sterilized ultrahigh‐molecular‐weight polyethylene (UHMWPE) has been observed when joint replacement hip and knee components are explanted during revision surgery. The purpose of the present study was to extend a previously published accelerated aging protocol for gamma‐sterilized UHMWPE. Unsterilized and gamma‐sterilized GUR 1150 resin samples were aged in phosphate‐buffered saline (PBS) at 40 or 50°C for up to 52 weeks. Under these conditions, slower changes in oxidation index (OI) occurred than those previously observed by aging at 60°C. Reduction of aging temperature below 60°C also changed the kinetics of oxidation such that the aldehyde peak (1732 cm−1) present at higher temperature was eliminated making the ketone/carboxylic acid region (1713–1718 cm−1) the primary region contributing to the calculation of the OIs for each group. The oxidation profiles obtained after 52 weeks at 40 and 50°C were consistent with retrievals that have undergone low oxidation, associated with maximum OI values of less than 1. Aging at 50°C represents a compromise between the slower oxidation rate of in vivo temperatures and the nonphysiological kinetics of elevated temperatures in an aqueous environment. However, even at 50°C over a year of in vitro aqueous aging will be necessary to reproduce the oxidation levels observed in long‐term implanted acetabular retrievals. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Rietveld structure and in vitro analysis on the influence of magnesium in biphasic (hydroxyapatite and β‐tricalcium phosphate) mixtures
Authors: Kannan S. , Goetz‐Neunhoeffer F. , Neubauer J. , Rebelo A.H.S. , Valério P. , Ferreira J.M.F. 
Published: December 2008

AbstractThe structure of two different Mg‐substituted biphasic (HAP and β‐TCP) mixtures along with the biphasic mixtures without substituted Mg2+ was investigated using Rietveld refinement technique. The substituted Mg2+ was found in the β‐TCP phase and its influence on the composition has led to an increase in HAP content of Mg‐containing biphasic mixtures when compared with the HAP content detected in pure biphasic mixtures. The refined structural parameters of Ca10(PO4)6(OH)2 and β‐Ca3(PO4)2 confirmed that all the investigated compositions have crystallized in the corresponding hexagonal (space group P63/m) and rhombohedral (space group R3c) structures. The substitution of lower sized magnesium was found preferentially incorporated at the sixfold‐coordinated Ca (5) site of β‐TCP, which is due to the strong Ca (5)·O interaction among all the five different Ca sites of β‐Ca3(PO4)2. The in vitro tests using primary culture of osteoblasts showed that all the tested samples are biocompatible and promising materials for in vivo studies. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Faster and stronger vascular “Biotube” graft fabrication in vivo using a novel nicotine‐containing mold
Authors: Sakai Osamu , Kanda Keiichi , Takamizawa Keiichi , Sato Takayuki , Yaku Hitoshi , Nakayama Yasuhide 
Published: December 2008

AbstractTo accelerate the fabrication of in vivo‐tissue engineered autologous vascular prosthetic tissues, the “Biotube,” a novel drug‐coating mold was designed. The mold was prepared by impregnating nicotine as a model drug into a gelatinous matrix coated on acrylate rods (diameter, 2 mm; length, 20 mm). Upon embedding the molds into dorsal subcutaneous pouches of rats, completely encapsulated Biotubes with significant tissue migration accompanied by rich angiogenesis and having 3.8 times as many neovessels as the uncoated controls, were formed at only 2 weeks. The wall thickness and burst strength of the Biotubes were 399.9 ± 135.2 μm and 2682.6 ± 722.6 mmHg, respectively. These values were, respectively, more than 9.6 and 3.2 times greater than the corresponding controls. Therefore, it is confidently expected that the mechanical properties of Biotubes obtained by nicotine coating make them suitable for application as vascular grafts. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Comparison of the osteoblast and myoblast behavior on hydroxyapatite microgrooves
Authors: Lu Xiong , Leng Yang 
Published: December 2008

AbstractSurface topography is one of the most important surface properties of biomaterials and microfabrication techniques provide new routes to produce precisely controlled surface topographies for investigating the topographic effects on cell behavior. In this study, hydroxyapatite (HA) microgrooved surfaces were used to study the osteoblast and myoblast response to the surface micro‐features. The microgrooves were first produced on silicon wafers by photolithography, and then coated with HA using sputtering technique. Orientation angle (OA) was used to evaluate the contact guidance introduced by microgrooves and form index (FI) was introduced to describe the cell morphology change. The results show that the microgroove effects on myoblasts are more obvious than those on osteoblasts, and the two types of cells are sensitive to different sizes of microgrooves. The microgrooves with 8 μm width strongly affect both osteoblasts and myoblasts, while the microgrooves with 24 μm width strongly affect myoblasts only. These results confirm that the surface topographic effect is of cell specific, and therefore, design of surface topographic features must be different for myoblasts and osteoblasts. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Endogenous FGF‐2 is critically important in PTH anabolic effects on bone
Authors: Sabbieti Maria Giovanna , Agas Dimitrios , Xiao Liping , Marchetti Luigi , Coffin J. Douglas , Doetschman Thomas , Hurley Marja M. 
Published: December 2008

AbstractParathyroid hormone (PTH) increases fibroblast growth factor receptor‐1 (FGFR1) and fibroblast growth factor‐2 (FGF‐2) expression in osteoblasts and the anabolic response to PTH is reduced in Fgf2−/− mice. This study examined whether candidate factors implicated in the anabolic response to PTH were modulated in Fgf2−/− osteoblasts. PTH increased Runx‐2 protein expression in Fgf2+/+ but not Fgf2−/− osteoblasts. By immunocytochemistry, PTH treatment induced nuclear accumulation of Runx‐2 only in Fgf2+/+ osteoblasts. PTH and FGF‐2 regulate Runx‐2 via activation of the cAMP response element binding proteins (CREBs). Western blot time course studies showed that PTH increased phospho‐CREB within 15 min that was sustained for 24 h in Fgf2+/+ but had no effect in Fgf2−/− osteoblasts. Silencing of FGF‐2 in Fgf2+/+ osteoblasts blocked the stimulatory effect of PTH on Runx‐2 and CREBs phosphorylation. Studies of the effects of PTH on proteins involved in osteoblast precursor proliferation and apoptosis showed that PTH increased cyclinD1‐cdk4/6 protein in Fgf2+/+ but not Fgf2−/− osteoblasts. Interestingly, PTH increased the cell cycle inhibitor p21/waf1 in Fgf2−/− osteoblasts. PTH increased Bcl‐2/Bax protein ratio in Fgf2+/+ but not Fgf2−/− osteoblasts. In addition PTH increased cell viability in Fgf2+/+ but not Fgf2−/− osteoblasts. These data suggest that endogenous FGF‐2 is important in PTH effects on osteoblast proliferation, differentiation, and apoptosis. Reduced expression of these factors may contribute to the reduced anabolic response to PTH in the Fgf2−/− mice. Our results strongly indicate that the anabolic PTH effect is dependent in part on FGF‐2 expression. J. Cell. Physiol. 219: 143–151, 2009. © 2008 Wiley‐Liss, Inc.
Roles of focal adhesions and fibronectin‐mediated cohesion in proliferation of confluent fibroblasts
Authors: Tanaka Maya , Abe Tatsuya , Hara Yoshitaka 
Published: December 2008

AbstractMultilayered fibroblast sheets have applications as cell transplants for tissue engineering. One way to increase their therapeutic efficacy is to increase cell numbers in a graft, but the factors influencing multilayered growth remain poorly understood. In this study, we investigated the roles of focal adhesion (FA) assembly and intercellular cohesion through fibronectin (FN) in the proliferation of normal human fibroblasts at confluence. Density‐dependent growth‐arrested fibroblasts resumed DNA synthesis when cultured in multilayer formation medium (MFM) containing transforming growth factor‐β1, ascorbic acid, and serum. This proliferation depended on α5β1‐integrin‐mediated cell‐FN‐cell interactions because blocking them with antibodies inhibited DNA synthesis. However, cell‐FN‐cell cohesion operated well regardless of exposure to MFM, judging from several parameters, including FN matrix deposition, activated β1 integrin expression, and stress fiber development. Density‐arrested cells formed few FAs at the cell center. Exposure of the cells to MFM induced the formation of vinculin‐, paxillin‐, and phosphotyrosine‐containing FAs throughout the ventral cell‐surface, indicating ROCK‐mediated actomyosin contractile force generation. When the assembly of FAs was inhibited with either the ROCK inhibitor Y‐27632 or the myosin II inhibitor blebbistatin, the up‐regulation of DNA synthesis by MFM was suppressed. The drugs did not impair FN matrix deposition, activated β1 integrin expression, and stress fiber development. Thus, these results indicate that the formation of FAs promotes the proliferation of confluent fibroblasts with the support of α5β1‐integrin‐mediated cell‐FN‐cell cohesion. The present findings provide insights into the rational design of high‐density fibroblast transplants. J. Cell. Physiol. 219: 194–201, 2009. © 2008 Wiley‐Liss, Inc.
Calcification or dedifferentiation: Requirement to lock mesenchymal stem cells in a desired differentiation stage
Authors: Dickhut Andrea , Pelttari Karoliina , Janicki Patricia , Wagner Wolfgang , Eckstein Volker , Egermann Marcus , Richter Wiltrud 
Published: December 2008

AbstractA current challenge in mesenchymal stem cell (MSC)‐based cartilage repair is to solve donor and tissue‐dependent variability of MSC cultures and to prevent chondrogenic cells from terminal differentiation like in the growth plate. The aim of this study was to select the best source for MSC which could promise stable cartilage formation in the absence of hypertrophy and ectopic in vivo mineralization. We hypothesized that MSC from synovium are superior to bone marrow‐ and adipose tissue‐derived MSC since they are derived from a joint tissue. MSC were characterized by flow cytometry. MSC pellets were cultured under chondrogenic conditions and differentiation was evaluated by histology, gene expression analysis, and determination of alkaline phosphatase activity (ALP). After chondrogenic induction, pellets were transplanted subcutaneously into SCID mice. MSC from bone marrow, adipose tissue, and synovium revealed similar COL2A1/COL10A1 mRNA levels after chondrogenic induction and were positive for collagen‐type‐X. Bone marrow‐derived and adipose tissue‐derived MSC showed significantly higher ALP activity than MSC from synovium. Low ALP‐activity before transplantation of pellets correlated with marginal calcification of explants. Surprisingly, non‐mineralizing transplants specifically lost their collagen‐type II, but not collagen‐type I deposition in vivo, or were fully degraded. In conclusion, the lower donor‐dependent ALP activation and reduced mineralization of synovium‐derived heterotopic transplants did not lead to stable ectopic cartilage as known from articular chondrocytes, but correlated with fibrous dedifferentation or complete degeneration of MSC pellets. This emphasizes that beside appropriate induction of differentiation, locking of MSC in the desired differentiation state is a major challenge for MSC‐based repair strategies. J. Cell. Physiol. 219: 219–226, 2009. © 2008 Wiley‐Liss, Inc.
Prenatal sonographic appearance of truncus arteriosus on wide‐band Doppler imaging
Authors: Hidaka Nobuhiro , Anami Ai , Yoshitomi Tomoyuki , Tsukimori Kiyomi , Wake Norio 
Published: December 2008

AbstractPersistent truncus arteriosus is an uncommon congenital cardiac anomaly. In most patients, this condition is not diagnosed prior to birth. We report a case in which this uncommon cardiac anomaly was diagnosed prenatally using wide‐band Doppler imaging. When diagnosing fetal truncus arteriosus, sonologists should carefully search for the origin of the main pulmonary artery and for its 2 branches. Our experience suggests that wide‐band Doppler imaging facilitates the prenatal diagnosis of truncus arteriosus. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2009
The pheromonal gland of Lymantria dispar: Morphology and evidence for its innervation
Authors: Boi Marianna , Quartu Marina , Serra Maria Pina , Solari Paolo , Melis Tiziana , Del Fiacco Marina 
Published: December 2008

AbstractThe morphological features of the glandular epithelium that secretes pheromone in the polyphagous pest gypsy moth Lymantria dispar are described by light and electron microscopy. The monolayered gland cells are covered by the folded cuticle of the intersegmental membrane between the 8th and 9th abdominal segments showing neither sites of discontinuity nor distinct openings on its external surface. The cells bear a large, often irregularly shaped nucleus, and contain granules of variable amount and electron‐density. These granules are mostly located in the basal compartment of the cytoplasm, in a labyrinthine zone laying on a basement membrane. The apical membrane of the gland cells bear microvilli and cell–cell contact is established by different junctional structures. Nerve fibers enwrapped in glia are found beneath the basement membrane, in close contact with the secretory cells. This latter finding represents the first evidence of the innervation of the pheromonal gland in L. dispar. J. Morphol. 2009. © 2008 Wiley‐Liss, Inc.
Ultrastructure of the body cavities in Phylactolaemata (Bryozoa)
Authors: Gruhl Alexander , Wegener Ines , Bartolomaeus Thomas 
Published: December 2008

AbstractOnly species belonging to the bryozoan subtaxon Phylactolaemata possess an epistome. To test whether there is a specific coelomic cavity inside the epistome, Fredericella sultana, Plumatella emarginata, and Lophopus crystallinus were studied on the ultrastructural level. In F. sultana and P. emarginata, the epistome contains a coelomic cavity. The cavity is confluent with the trunk coelom and lined by peritoneal and myoepithelial cells. The lophophore coelom extends into the tentacles and is connected to the trunk coelom by two weakly ciliated coelomic ducts on either side of the rectum. The lophophore coelom passes the epistome coelom on its anterior side. This region has traditionally been called the forked canal and hypothesized to represent the site of excretion. L. crystallinus lacks an epistome. It has a simple ciliated field where an epistome is situated in the other species. Underneath this field, the forked canal is situated. Compared with the other species, it is pronounced and exhibits a dense ciliation. Despite the occurrence of podocytes, which are prerequisites for a selected fluid transfer, there is no indication for an excretory function of the forked canal, especially as no excretory porus was found. J. Morphol. 2009. © 2008 Wiley‐Liss, Inc.
Anatomy and ultrastructure of the female reproductive system of Pleioplana atomata (Platyhelminthes: Polycladida)
Authors: Liana Marcin K. , Litvaitis Marian K. 
Published: December 2008

AbstractThe ultrastructure of the female reproductive system of the polyclad flatworm Pleioplana atomata is described. Numerous ovaries are scattered throughout the entire body but are mainly concentrated on the dorsal side. Within an ovary, a germinative zone with oogonia and prefolicular cells is located in the dorsal part of the ovary. The remaining part of the gonad is filled with previtellogenic and early vitellogenic oocytes enwrapped by follicular cells. During previtellogenesis, oocytes produce numerous eggshell globules, which are distributed into the cortical area of the cell in later stages. Eventually, these globules release their contents into the space between the eggshell cover and oolemma. Similar types of globules are also found in others flatworms, and may represent useful phylogenetic characters. Entolecital, vitellogenic oocytes pass to paired uteri, where vitellogenesis is completed. The remainder of the female reproductive system consists of paired thin uterine ducts that join a vagina. The distal part of the long, curved vagina forms a large Lang's vesicle, while the proximal part is connected to a female atrium leading to a female gonopore. We hypothesize that Lang's vesicle functions in the digestion of excess sperm received. Two kinds of different shell (cement) glands that release their secretion into the vagina are identified. Both are unicellular glands and each gland cell connects to the lumen of the vagina via an individual canal. Similar glands in other acotylean polyclads have been implicated in the formation of eggshell covers. J. Morphol. 2009. © 2008 Wiley‐Liss, Inc.
Evolutionary morphology of the Tenrecoidea (Mammalia) hindlimb skeleton
Authors: Salton Justine A. , Sargis Eric J. 
Published: December 2008

AbstractThe tenrecs of Central Africa and Madagascar provide an excellent model for exploring adaptive radiation and functional aspects of mammalian hindlimb form. The pelvic girdle, femur, and crus of 13 tenrecoid species, and four species from the families Solenodontidae, Macroscelididae, and Erinaceidae, were examined and measured. Results from qualitative and quantitative analyses demonstrate remarkable diversity in several aspects of knee and hip joint skeletal form that are supportive of function‐based hypotheses, and consistent with studies on nontenrecoid eutherian postcranial adaptation. Locomotor specialists within Tenrecoidea exhibit suites of characteristics that are widespread among eutherians with similar locomotor behaviors. Furthermore, several characters that are constrained at the subfamily level were identified. Such characters are more indicative of postural behavior than locomotor behavior. J. Morphol., 2009. © 2008 Wiley‐Liss, Inc.
Three‐dimensional reconstruction of the odontophoral cartilages of Caenogastropoda (Mollusca: Gastropoda) using micro‐CT: Morphology and phylogenetic significance
Authors: Golding Rosemary E. , Ponder Winston F. , Byrne Maria 
Published: December 2008

AbstractOdontophoral cartilages are located in the molluscan buccal mass and support the movement of the radula during feeding. The structural diversity of odontophoral cartilages is currently known only from limited taxa, but this information is important for interpreting phylogeny and for understanding the biomechanical operation of the buccal mass. Caenogastropods exhibit a wide variety of feeding strategies, but there is little comparative information on cartilage morphology within this group. The morphology of caenogastropod odontophoral cartilages is currently known only from dissection and histology, although preliminary results suggest that they may be structurally diverse. A comparative morphological survey of 18 caenogastropods and three noncaenogastropods has been conducted, sampling most major caenogastropod superfamilies. Three‐dimensional models of the odontophoral cartilages were generated using X‐ray microscopy (micro‐CT) and reconstruction by image segmentation. Considerable morphological diversity of the odontophoral cartilages was found within Caenogastropoda, including the presence of thin cartilaginous appendages, asymmetrically overlapping cartilages, and reflexed cartilage margins. Many basal caenogastropod taxa possess previously unidentified cartilaginous support structures below the radula (subradular cartilages), which may be homologous to the dorsal cartilages of other gastropods. As subradular cartilages were absent in carnivorous caenogastropods, adaptation to trophic specialization is likely. However, incongruence with specific feeding strategies or body size suggests that the morphology of odontophoral cartilages is constrained by phylogeny, representing a new source of morphological characters to improve the phylogenetic resolution of this group. J. Morphol. 2009. © 2008 Wiley‐Liss, Inc.
Ultrastructural investigation of the vesicular glands in Scutigera coleoptrata (Chilopoda, Notostigmophora)
Authors: Hilken Gero , Rosenberg Jörg 
Published: December 2008

AbstractIn the notostigmophoran centipedes, two pairs of vesicular glands have evolved. These paired glands are situated in the first and second trunk segment and open via cuticular ducts in the upper part of the particular pleura. The vesicular glands of Scutigera coleoptrata were investigated using light and, for the first time, electron microscopical methods. The glands consist of wide sac‐like cavities that often appear vesicular. The epithelia of both glands are identically structured and consist of numerous glandular units. Each of these units consists of four different cells: a single secretory cell, a small intermediary cell, and one proximal and one distal canal cell. The intermediary cell forms a conducting canal and connects the secretory cell with the canal cells. Proximally, the intermediary cell bears microvilli, whereas the distal part is covered with a distinct cuticle. The cuticle is a continuation of the cuticle of the canal cells. This investigation shows that the ultrastructure of glandular units of the vesicular glands is comparable to that of the glandular units of other epidermal glands in Chilopoda and Diplopoda, although the glands look completely different in the light microscope. Thus, it is likely that the vesicular glands and epidermal glands share the same ground pattern. With regard to specific differences in the cuticular lining of the intermediary cells, a common origin of epidermal glands in Myriapoda and Hexapoda is not supported. J. Morphol. 2009. © 2008 Wiley‐Liss, Inc.