bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proteomic evaluation reveals that olfactory ensheathing cells but not Schwann cells express calponin
Authors: Boyd J. Gordon , Jahed Ali , McDonald Todd G. , Krol Karmen M. , Van Eyk Jennifer E. , Doucette Ronald , Kawaja Michael D. 
Published: December 2005

AbstractHuman clinical trials have begun worldwide that use olfactory ensheathing cells (OECs) to ameliorate the functional deficits following spinal cord injury. These trials have been initiated largely because numerous studies have reported that OECs transform into Schwann Cell (SC)‐like cells that myelinate axons and support new growth in adult rats with spinal injury. This phenomenon is remarkable because OECs do not myelinate olfactory axons in their native environment. Furthermore, these myelinating OECs are morphologically identical to SCs, which can invade the spinal cord after injury. One factor that has contributed to a possible confusion in the identification of these cells is the lack of phenotypic markers to distinguish unequivocally between OECs and SCs. Such markers are required to first assess the degree of SC contamination in OEC cultures before intraspinal implantation, and then to accurately identify grafted OECs and invading SCs in the injured spinal cord. Using two‐dimensional gel electrophoresis, we have identified calponin, an actin binding protein, as the first definitive phenotypic marker that distinguishes between OECs and SCs in vitro and in vivo. We have also provided ultrastructural evidence that calponin‐immunopositive OECs do not transform into myelinating SC‐like cells after intraspinal implantation. Rather, the grafted OECs retain their morphological and neurochemical features. These data yield new insight into the phenotypic characteristics of OECs, which together with invading SCs can enhance regeneration of the injured spinal cord. © 2005 Wiley‐Liss, Inc.
cAMP cascade (PKA, Epac, adenylyl cyclase, Gi, and phosphodiesterases) regulates myelin phagocytosis mediated by complement receptor‐3 and scavenger receptor‐AI/II in microglia and macrophages
Authors: Makranz Chen , Cohen Goni , Reichert Fanny , Kodama Tatsuhiko , Rotshenker Shlomo 
Published: December 2005

AbstractThe removal by phagocytosis of degenerated myelin is central for repair in Wallerian degeneration that follows traumatic injury to axons and in autoimmune demyelinating diseases (e.g., multiple sclerosis). We tested for roles played by the cAMP cascade in the regulation of myelin phagocytosis mediated by complement receptor‐3 (CR3/MAC‐1) and scavenger receptor‐AI/II (SRAI/II) separately and combined in mouse microglia and macrophages. Components of the cAMP cascade tested are cAMP, adenylyl cyclase (AC), Gi, protein kinase A (PKA), exchange protein directly activated by cAMP (Epac), and phosphodiesterases (PDE). PKA inhibitors H‐89 and PKI14‐22 amide inhibited phagocytosis at normal operating cAMP levels (i.e., those occurring in the absence of reagents that alter cAMP levels), suggesting activation of phagocytosis through PKA at normal cAMP levels. Phagocytosis was inhibited by reagents that elevate endogenous cAMP levels to above normal: Gi‐inhibitor Pertussis toxin (PTX), AC activator Forskolin, and PDE inhibitors IBMX and Rolipram. Phagocytosis was inhibited also by cAMP analogues whose addition mimics abnormal elevations in endogenous cAMP levels: nonselective 8‐bromo‐cAMP, PKA‐specific 6‐Benz‐cAMP, and Epac‐specific 8‐CPT‐2′‐O‐Me‐cAMP, suggesting that abnormal high cAMP levels inhibit phagocytosis through PKA and Epac. Altogether, observations suggest a dual role for cAMP and PKA in phagocytosis: activation at normal cAMP levels and inhibition at higher. Furthermore, a balance between Gi‐controlled cAMP production by AC and cAMP degradation by PDE maintains normal operating cAMP levels that enable efficient phagocytosis. ©2005 Wiley‐Liss, Inc.
Survival of neural precursor cells in growth factor‐poor environment: Implications for transplantation in chronic disease
Authors: Einstein Ofira , Ben‐Menachem‐Tzidon Ofra , Mizrachi‐Kol Rachel , Reinhartz Etti , Grigoriadis Nikolaos , Ben‐Hur Tamir 
Published: December 2005

AbstractA key issue for therapeutic neural stem cell transplantation in chronic diseases is the long‐term survival of transplanted cells in the brain. The normal adult central nervous system does not support the survival of transplanted cells. Presumably, the limited availability of trophic factors maintains the survival of resident cells but is insufficient for supporting the survival of transplanted cells. Specifically, in multiple sclerosis, a chronic relapsing disease, it would be necessary to maintain long‐term survival of transplanted cells through phases of relapses and remissions. It may be beneficial to transplant cells as early as possible, in a form that will keep their survival independent of tissue support and ready for immediate mobilization upon tissue demand during disease relapse. In the present study, we examined whether, in the form of neurospheres, multipotential neural precursor cells (NPCs) survive in a growth factor‐poor environment while maintaining their potential to respond to environmental cues. We found that after removal of growth factors from the culture medium of neurospheres in vitro, NPC proliferation decreased significantly, but most cells survived for a prolonged time and maintained their stem cell characteristics. After re‐exposure to growth factors, neurosphere cells resumed proliferation and could differentiate along neural lineages. Furthermore, neurospheres, but not single NPCs, that were transplanted into the brain ventricles of intact animals survived within the ventricles for at least a month and responded to induction of experimental autoimmune encephalomyelitis and brain inflammation by extensive migration into the brain white matter and differentiated into glial lineage cells. © 2005 Wiley‐Liss, Inc.
Prognostic impact of cytogenetic aberrations in patients with multiple myeloma or monoclonal gammopathy of unknown significance
Authors: Schilling Georgia , Dierlamm Judith , Hossfeld Dieter K 
Published: December 2005

AbstractChromosomal aberrations are the most important prognostic factors in haematological malignancies. Detection of certain genetic changes leads to risk adapted strategies in leukaemia therapy. In multiple myeloma the importance of genetic alterations and their prognostic impact is of growing interest. Several therapeutic approaches seem to be uneffective for patients harbouring certain chromosomal abnormalities.Although the yield of metaphases due to a low proliferation rate is considerably lower in plasma cell dyscrasias, a number of chromosomal changes with prognostic implications have been identified in the past years, particularly due to the introduction of new techniques.This article gives a short survey of the most important genetic alterations and their prognostic influence on the outcome of patients with plasma cell malignancies known to date. Copyright © 2005 John Wiley & Sons, Ltd.
Evidence of abortive plasma cell differentiation in Hodgkin and Reed‐Sternberg cells of classical Hodgkin lymphoma
Authors: Buettner Maike , Greiner Axel , Avramidou Athanasia , Jäck Hans‐Martin , Niedobitek Gerald 
Published: December 2005

AbstractHodgkin and Reed‐Sternberg (HRS) cells of classical Hodgkin lymphoma (cHL) show genotypic features of germinal centre‐derived B‐cells in most cases. Nevertheless, these cells typically lack expression of B‐cell antigens. Previous studies have suggested that plasma cell differentiation may occur in HRS cells and that this may account for the down‐regulation of B‐cell antigens. However, these results are controversial. We have addressed this question using immunohistochemistry and a panel of antibodies directed against antigens which are differentially expressed during terminal B‐cell differentiation. Pax‐5, a transcription factor required for B‐lineage commitment, and IRF4/Mum1, which is physiologically expressed in germinal centre cells and plasma cells, were consistently detectable in HRS cells. Bcl‐6, a transcription factor expressed in germinal centre B‐cells, was present in HRS cells of approximately 25% of cHL cases. Expression of the B‐lymphocyte‐induced maturation protein‐1 (Blimp‐1), a key regulator of plasma cell differentiation, was observed in HRS cells of 23% of cHL cases. In these cases, Blimp‐1 expression was restricted to a small proportion of HRS cells. HRS cells were consistently negative for the plasma cell marker CD138. These results suggest that plasma cell differentiation may be initiated in a small subset of HRS cells but remains abortive. Thus, terminal differentiation is unlikely to explain the lack of B‐cell antigen expression in HRS cells. Copyright © 2005 John Wiley & Sons, Ltd.
Seasonal snowpack dynamics and runoff in a cool temperate forest: lysimeter experiment in Niigata, Japan
Authors: Whitaker Andrew C. , Sugiyama Hironobu 
Published: December 2005

AbstractSeasonal snowpack dynamics are described through field measurements under contrasting canopy conditions for a mountainous catchment in the Japan Sea region. Microclimatic data, snow accumulation, albedo and lysimeter runoff are given through the complete winter season 2002–03 in (1) a mature cedar stand, (2) a larch stand, and (3) a regenerating cedar stand or opening. The accumulation and melt of seasonal snowpack strongly influences streamflow runoff during December to May, including winter baseflow, mid‐winter melt, rain on snow, and diurnal peaks driven by radiation melt in spring. Lysimeter runoff at all sites is characterized by constant ground melt of 0·8–1·0 mm day−1. Rapid response to mid‐winter melt or rainfall shows that the snowpack remains in a ripe or near‐ripe condition throughout the snow‐cover season. Hourly and daily lysimeter discharge was greatest during rain on snow (e.g. 7 mm h−1 and 53 mm day−1 on 17 December) with the majority of runoff due to rainfall passing through the snowpack as opposed to snowmelt. For both rain‐on‐snow and radiation melt events lysimeter discharge was generally greatest at the open site, although there were exceptions such as during interception melt events. During radiation melt instantaneous discharge was up to 4·0 times greater in the opening compared with the mature cedar, and 48 h discharge was up to 2·5 times greater. Perhaps characteristic of maritime climates, forest interception melt is shown to be important in addition to sublimation in reducing snow accumulation beneath dense canopies. While sublimation represents a loss from the catchment water balance, interception melt percolates through the snowpack and contributes to soil moisture during the winter season. Strong differences in microclimate and snowpack albedo persisted between cedar, larch and open sites, and it is suggested further work is needed to account for this in hydrological simulation models. Copyright © 2005 John Wiley & Sons, Ltd.
Responses of MC3T3‐E1 cells to three dental resin‐based restorative materials
Authors: Imazato Satoshi , Horikawa Daisuke , Ogata Korenori , Kinomoto Yoshifumi , Ebisu Shigeyuki 
Published: December 2005

AbstractThis study aimed to examine the influences of three dental resin‐based restorative materials on cells associated with hard tissue regeneration using osteoblastic MC3T3‐E1 cells. A Bis‐GMA‐based resin composite [Clearfil AP‐X (APX)], an MMA‐based resin cement [Superbond C&B (SB)], and a resin‐modified glass‐ionomer [Fuji Ionomer Type II LC (LC)] were tested. A zinc oxide eugenol cement [Super EBA (EBA)] was included in the study for comparison. MC3T3‐E1 cells were cultured on set materials for 3, 7, 14, or 21 days. Cell attachment and proliferation were observed by scanning electron microscopy, and mitochondrial dehydrogenase and alkaline phosphatase (ALP) activities of the cells were evaluated. Cell cultures on polystyrene tissue culture dishes served as controls. On APX and SB, cells demonstrated attachment, spreading, and proliferation similar to the controls. In contract, cells adhered and proliferated poorly on LC and EBA. The mitochondrial function and ALP activity of the cells were significantly suppressed (p < 0.05, Scheffe's F test) throughout the experimental period when cultured on LC or EBA, although APX and SB exhibited less inhibition. The results indicate that APX and SB are less toxic to proliferation and differentiation of MC3T3‐E1, suggesting that a smaller influence on cementogenesis on these materials can be expected. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Single dose vaccine based on biodegradable polyanhydride microspheres can modulate immune response mechanism
Authors: Kipper Matt J. , Wilson Jennifer H. , Wannemuehler Michael J. , Narasimhan Balaji 
Published: December 2005

AbstractThis study focuses on the development of single dose vaccines based on biodegradable polyanhydride microspheres that have the unique capability to modulate the immune response mechanism. The polymer system employed consists of copolymers of 1,6‐bis(p‐carboxyphenoxy)hexane and sebacic acid. Two copolymer formulations that have been shown to provide extended release kinetics and protein stability were investigated. Using tetanus toxoid (TT) as a model antigen, in vivo studies in C3H/HeOuJ mice demonstrated that the encapsulation procedure preserves the immunogenicity of the TT. The polymer itself exhibited an adjuvant effect, enhancing the immune response to a small dose of TT. The microspheres provided a prolonged exposure to TT sufficient to induce both a primary and a secondary immune response (i.e., high antibody titers) with high‐avidity antibody production, without requiring an additional administration. Antigen‐specific proliferation 28 weeks after a single immunization indicated that immunization with the polyanhydride microspheres generated long‐lived memory cells and plasma cells (antibody‐secreting B cells) that generally do not occur without maturation signals from T helper cells. Furthermore, by altering the vaccine formulation, the overall strength of the T helper type 2 immune response was selectively diminished, resulting in a balanced immune response, without reducing the overall titer. This result is striking, considering free TT induces a T helper type 2 immune response, and has important implications for developing vaccines to intracellular pathogens. The ability to selectively tune the immune response without the administration of additional cytokines or noxious adjuvants is a unique feature of this delivery vehicle that may make it an excellent candidate for vaccine development. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Human neutrophils reaction to the biodegraded nano‐hydroxyapatite/collagen and nano‐hydroxyapatite/collagen/poly(L‐lactic acid) composites
Authors: Liao Susan , Tamura Kazuchika , Zhu Yuhe , Wang Wei , Uo Motohiro , Akasaka Tsukasa , Cui Fuzhai , Watari Fumio 
Published: December 2005

AbstractThe impact of biodegraded nano‐hydroxyapatite/collagen (nHAC) composite and nano‐hydroxyapatite/collagen/poly(L‐lactic acid) (nHAC/PLA) scaffold composite on neutrophils reaction was evaluated in vitro. Neutrophils were separated from human peripheral blood of healthy subjects. The nHAC and nHAC/PLA materials were immersed in the D‐Hanks' Balanced Salt Solution (D‐HBSS) for 1 day, 7 days and 2, 4, 8 weeks (37°C) as testing solution, which mixed with the neutrophils for 1 h. Both of the nHAC and nHAC/PLA materials were shown the same cell survival rate as blank control, but the lactate dehydrogenase (LDH) and tumor necrosis factor alpha (TNF‐α) released from the neutrophils were increased significantly after the 2 weeks in nHAC sample. The possible reason relied on the high concentration of calcium due to the quick biodegradation of the nHAC material. Before 2 weeks, the LDH value of nHAC/PLA is higher than that of nHAC sample that corresponded to the initial PLA degradation in vitro. This study provided the biocompatibility test of neutrophils other than common methods, such as osteoblastic cells for biomimetic materials. Moreover, it demonstrated the calcium concentration stimulating effect for cytokine release from neutrophils. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Three‐dimensional nanofibrillar surfaces covalently modified with tenascin‐C‐derived peptides enhance neuronal growth in vitro
Authors: Ahmed Ijaz , Liu Hsing‐Yin , Mamiya Ping C. , Ponery Abdul S. , Babu Ashwin N. , Weik Thom , Schindler Melvin , Meiners Sally 
Published: December 2005

AbstractCurrent methods to promote growth of cultured neurons use two‐dimensional (2D) glass or polystyrene surfaces coated with a charged molecule (e.g. poly‐L‐lysine (PLL)) or an isolated extracellular matrix (ECM) protein (e.g. laminin‐1). However, these 2D surfaces represent a poor topological approximation of the three‐dimensional (3D) architecture of the assembled ECM that regulates neuronal growth in vivo. Here we report on the development of a new 3D synthetic nanofibrillar surface for the culture of neurons. This nanofibrillar surface is composed of polyamide nanofibers whose organization mimics the porosity and geometry of the ECM. Neuronal adhesion and neurite outgrowth from cerebellar granule, cerebral cortical, hippocampal, motor, and dorsal root ganglion neurons were similar on nanofibers and PLL‐coated glass coverslips; however, neurite generation was increased. Moreover, covalent modification of the nanofibers with neuroactive peptides derived from human tenascin‐C significantly enhanced the ability of the nanofibers to facilitate neuronal attachment, neurite generation, and neurite extension in vitro. Hence the 3D nanofibrillar surface provides a physically and chemically stabile cell culture surface for neurons and, potentially, an exciting new opportunity for the development of peptide‐modified matrices for use in strategies designed to encourage axonal regrowth following central nervous system injury. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Organic overlayer model of a dental composite analyzed by laser desorption postionization mass spectrometry and photoemission
Authors: Zhou Manshui , Wu Chunping , Edirisinghe Praneeth D. , Drummond James L. , Hanley Luke 
Published: December 2005

AbstractSome dental composites consist of a polymerizable resin matrix bound to glass filler particles by silane coupling agents. The resin in these composites includes bisphenol A diglycidyl methacrylate (Bis‐GMA) as well as other organic components. Silane coupling agents such as 3‐(trimethoxysilyl) propyl methacrylate (MPS) have been used to improve the mechanical properties of the dental composites by forming a covalent bond between the glass filler particles and the resin. These resin–glass composites undergo material property changes during exposure to the oral environment, but degradation studies of the commercial composites are severely limited by their chemical complexity. A simplified model of the dental composite has been developed, which captures the essential chemical characteristics of the filler particle–silane–resin interface. This model system consists of the resin matrix compound Bis‐GMA covalently bound via a methacryloyl overlayer to amorphous silicon oxide (SiO2) surface via a siloxane bond. Scanning electron microscopy shows the porous characteristic and elemental composition of the SiO2 film, which approximately mimics that of the glass filler particles used in dental composites. LDPI MS and XPS verify the chemistry and morphology of the Bis‐GMA‐methacryloyl overlayer. Preliminary results demonstrate that LDPI MS will be able to follow the chemical processes resulting from aging Bis‐GMA‐methacryloyl overlayers aged in water, artificial saliva, or other aging solutions. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Manufacture of multimicrotubule chitosan nerve conduits with novel molds and characterization in vitro
Authors: Ao Qiang , Wang Aijun , Cao Wenling , Zhang Ling , Kong Lijun , He Qing , Gong Yandao , Zhang Xiufang 
Published: December 2005

AbstractMultimicrotubule chitosan conduits (M‐conduits) were fabricated using novel molds and a thermal‐induced phase‐separation technique. Hollow chitosan conduits (H‐conduits) with an inner diameter of 1–5 mm and a wall thickness of 0.2–1.0 mm were made, and then a novel mold composed of a styrofoam insulating pedestal with several holes and a stainless steel cover plate was used to make M‐conduits. In brief, corresponding H‐conduits were inserted upright into the holes of the styrofoam pedestal, and filled with chitosan solution, then rapidly covered with the precooled stainless steel cover plate, and then placed in a freezer. The styrofoam insulating pedestal enclosing the conduits could reduce the heat transfer through the side wall of the conduits. Gradual phase separation then occurred uniaxially in the presence of a unidirectional temperature gradient from the top end to the bottom end of the chitosan conduits. The phase‐separated polymer/solvent systems were then dried in a freeze‐dryer. The microtubule diameters were controlled by adjusting the polymer concentration and cooling temperature. In vitro characterization demonstrated that the mold‐based multimicrotubule chitosan conduits possessed suitable mechanical strength, microtubule diameter distribution, porosity, swelling, biodegradability, and nerve cell affinity, and so they showed potential for application as nerve tissue engineering scaffolds. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Role of phase diagram of membrane formation system in controlling the crystallinity and degradation rate of PLLA membranes
Authors: Lee I‐Chi , Cheng Liao‐Ping , Young Tai‐Horng 
Published: December 2005

AbstractIn this work, the theoretical phase diagram of membrane formation system of ethanol, methylene chloride, and poly‐L‐lactide (PLLA) was studied. On the basis of the phase diagram, particulate and porous membranes, dominated by crystallization and liquid–liquid demixing, respectively, were prepared. Furthermore, degradation of PLLA membranes with particulate, porous, and dense morphologies was performed in phosphate buffered solution (PBS) at 37°C for 168 days and was investigated by mass loss, scanning electron microscopy (SEM), gel permeation chromatography (GPC), and differential scanning calorimetry (DSC). Besides the membrane morphology, a close relationship between the phase behavior of the membrane formation system and the membrane crystallinity was found, which in turn influenced the degradation rate of these membranes significantly. In the case of dense membranes, it showed the lowest initial crystallinity and the greatest rate of mass loss and molecular weight decrease compared with particulate and porous membranes. In contrast, the particulate membranes had the highest crystallinity and the slowest degradation rate in this study. Therefore, the phase diagram of membrane formation system could not only anticipate membrane morphology, but could also control the membrane crystallinity and degradation rate simultaneously. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006