bluuebunny/crossref_metadata_2025_split huggingface dataset:
Astrocyte‐induced regulatory T cells mitigate CNS autoimmunity
Authors: Trajkovic Vladimir , Vuckovic Olivera , Stosic‐Grujicic Stanislava , Miljkovic Djordje , Popadic Dusan , Markovic Milos , Bumbasirevic Vladimir , Backovic Aleksandar , Cvetkovic Ivana , Harhaji Ljubica , Ramic Zorica , Mostarica Stojkovic Marija 
Published: April 2004

AbstractAlthough astrocytes presumably participate in maintaining the immune privilege of the central nervous system (CNS), the mechanisms behind their immunoregulatory properties are still largely undefined. In this study, we describe the development of regulatory T cells upon contact with astrocytes. Rat T cells pre‐incubated with astrocytes completely lost the ability to proliferate in response to mitogenic stimuli. The cells were blocked in G0/G1 phase of the cell cycle, expressed less IL‐2R, and produced significantly lower amounts of interferon‐γ (IFN‐γ), but not interleukin‐2 (IL‐2), IL‐10, or tumor necrosis factor (TNF). These anergic cells completely prevented mitogen‐induced growth of normal T lymphocytes, as well as CNS antigen‐driven proliferation of autoreactive T cells. The suppressive activity resided in both CD4+ and CD8+ T‐cell compartments. Heat‐sensitive soluble T‐cell factors, not including transforming growth factor‐β (TGF‐β) or IL‐10, were solely responsible for the observed suppression, as well as for the transfer of suppressive activity to normal T cells. The administration of astrocyte‐induced regulatory T cells markedly alleviated CNS inflammation and clinical symptoms of CNS autoimmunity in rats with experimental allergic encephalomyelitis. Finally, the cells with suppressive properties were readily generated from human lymphocytes after contact with astrocytes. Taken together, these data indicate that astrocyte‐induced regulatory T cells might represent an important mechanism for self‐limitation of excessive inflammation in the brain. © 2004 Wiley‐Liss, Inc.
Nestin expression in hippocampal astrocytes after injury depends on the age of the hippocampus
Authors: Abdel‐Rahman Ali , Rao Muddanna S. , Shetty Ashok K. 
Published: April 2004

AbstractAnalysis of the expression of nestin in reactive astrocytes facilitates quantification of the extent of activation of astrocytes after injury in the mature CNS. We hypothesize that the capability of astrocytes for re‐expressing nestin in response to CNS injury diminishes as a function of age. We quantified astrocytes positive for S‐100β protein, glial fibrillary acidic protein (GFAP) and nestin in the hippocampus of young adult, middle‐aged, and aged Fischer 344 rats after an intracerebroventricular kainic acid (KA) administration. In all age groups, KA administration induced degeneration of CA3 pyramidal neurons, which led to a significant deafferentation in the CA1 region. The KA‐induced neurodegeneration and deafferentation resulted in an increased population of astrocytes positive for S‐100β and glial fibrillary acidic protein (GFAP) in all age groups. Interestingly, these increases were highly comparable across the three age groups. However, in areas of both neurodegeneration and deafferentation, the overall numerical density of nestin‐positive reactive astrocytes varied depending on the age at the time of injury with noticeably decreased numerical density in the injured middle‐aged and aged hippocampus. In contrast, nestin‐immunoreactive radial glia framework after lesion is not impaired with aging in the ependymal lining of the CA3 region. © 2004 Wiley‐Liss, Inc.
Comparative study of the in vitro apatite‐forming ability of poly(ε‐caprolactone)–silica sol–gels using three osteoconductivity tests (static, dynamic, and alternate soaking process)
Authors: Eglin David , Ali Saad A. M. , Perry Carole C. 
Published: April 2004

AbstractThe in vitro apatite‐forming ability of poly(ε‐caprolactone) (70 wt %)–silica sol–gels, with hydroxyl and triethoxysilane end‐groups with potential use in bone repair have been assessed using static and dynamic osteoconductivity tests. Diffuse reflectance infrared spectroscopy, scanning electron microscopy, and microanalysis techniques were used to observe and characterize precipitates formed on the material's surface. An apatite layer was observed to form on both of the composites' surface. However, variations were observed according to the test method used, in accordance with other studies on bioactive ceramics. A third method, the “alternate soaking process” (ASP) was developed to provide rapid results and quantify the amount of calcium‐containing precipitates formed on the surface of potentially “bioactive” materials. The results presented here show that for a material to be bioactive and have the ability to form a precipitate containing calcium and phosphate ions, levels of calcium ions measured by a complexometric assay should be significantly higher than the level of 5 μg/cm2. This level of calcium ions was obtained after 20 ASP cycles for the hydroxyl and triethoxysilane end‐capped poly(ε‐caprolactone) samples that did not form precipitates on their surfaces even after >50 ASP cycles. For the two sol–gel silica composites containing approximately 70% hydroxyl and triethoxysilane poly(ε‐caprolactone), there was no significant difference in the amount of calcium‐containing precipitate as observed using the in vitro apatite‐forming ability tests suggesting that polymer end‐group modification is not detrimental to the apatite‐forming ability of such composites. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 69A: 718–727, 2004
Novel polymer‐synthesized ceramic composite–based system for bone repair: An in vitro evaluation
Authors: Khan Yusuf M. , Katti Dhirendra S. , Laurencin Cato T. 
Published: April 2004

AbstractThe emergence of synthetic bone repair scaffolds has been necessitated by the limitations of both autografts and allografts. Several candidate materials are available including degradable polymers and ceramics. However, these materials possess their own limitations that at least in part may be overcome by combining the two materials into a composite. Toward that end, a novel approach to forming a polymer/ceramic composite has been developed that combines degradable poly(lactide‐co‐glycolide) microspheres and a poorly crystalline calcium phosphate that is synthesized within the microspheres, which are then fused together to form a porous three‐dimensional scaffold for bone repair. The design, fabrication, and characterization of the composite microspheres, the calcium phosphate formed within these microspheres, and the formation of scaffolds were studied. The calcium phosphate formed was analyzed by x‐ray diffraction, Fourier transform infrared spectroscopy, and energy dispersive spectroscopy, and was shown to be similar to native bone in both composition and crystallinity by controlling certain processing parameters such as mixing time, solution pH, and mixing temperature. Scaffolds with porous interconnected structures and mechanical properties in the range of trabecular bone were fabricated via precise control of polymer/ceramic ratios within the microspheres and scaffold heating times. This composite scaffold represents a new and important vehicle for bone‐tissue engineering. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 69A: 728–737, 2004
Bone cement X‐ray contrast media: A clinically relevant method of measuring their efficacy
Authors: Kjellson F. , Almén T. , Tanner K.E. , McCarthy I.D. , Lidgren L. 
Published: April 2004

AbstractIt is important to compare different contrast media used in bone cement according to their ability to attenuate X‐rays and thereby produce image contrast between bone cement and its surroundings in clinical applications. The radiopacity of bone cement is often evaluated by making radiographs of cement in air at an X‐ray tube voltage of 40 kV. We have developed a method for ranking contrast media in bone cement simulating the clinical situation, by (1) choosing the same X‐ray tube voltage as used in clinical work, and (2) using a water phantom to imitate the effects of the patients' soft tissue on the X‐ray photons. In clinical work it is desirable to have low radiation dose, but high image contrast. The voltage chosen is a compromise, because both dose and image contrast decrease with higher voltage. Three contrast media (ZrO2, BaSO4, and Iodixanol) have been compared for degree of “image contrast.” Comparing 10 wt % contrast media samples at an X‐ray tube voltage of 40 kV, ZrO2 produced higher image contrast than the other media. However, at 80 kV, using a water phantom, the results were reversed, ZrO2 produced lower image contrast than both BaSO4 and Iodixanol. We conclude that evaluations of contrast media should be made with voltages and phantoms imitating the clinical application. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 70B: 354–361, 2004
Focal dystonia after removal of a parietal meningioma
Authors: Khan Aijaz A. , Sussman Jon D. 
Published: April 2004

AbstractA patient presented at the age of 50 years with a right‐sided, writing‐specific dystonia which settled without treatment. Ten years later she developed focal seizures affecting the right leg and occasionally spreading to the right arm. A left parietal meningioma was removed and 2 years later she developed dystonic movements of her right hand. Gliotic changes were seen on magnetic resonance imaging in the superficial left parietal lobe. Mechanisms involved in the generation of dystonia associated with cortical injury are discussed. © 2004 Movement Disorder Society
The International Protein Index: An integrated database for proteomics experiments
Authors: Kersey Paul J. , Duarte Jorge , Williams Allyson , Karavidopoulou Youla , Birney Ewan , Apweiler Rolf 
Published: April 2004

AbstractDespite the complete determination of the genome sequence of several higher eukaryotes, their proteomes remain relatively poorly defined. Information about proteins identified by different experimental and computational methods is stored in different databases, meaning that no single resource offers full coverage of known and predicted proteins. IPI (the International Protein Index) has been developed to address these issues and offers complete nonredundant data sets representing the human, mouse and rat proteomes, built from the Swiss‐Prot, TrEMBL, Ensembl and RefSeq databases.
A proteomic analysis of changes in prothrombin and plasma proteins associated with the G20210A mutation
Authors: Gelfi Cecilia , Viganò Agnese , Ripamonti Marilena , Wait Robin , Begum Shajna , Biguzzi Eugenia , Castaman Giancarlo , Faioni Elena Maria 
Published: April 2004

AbstractThe G→A mutation at position 20210 of the prothrombin gene, localized in the 3'‐polyadenylation untranslated region of the mRNA, is a recognized genetic risk factor for venous thromboembolism. The mechanism by which this base change confers an increased risk of thrombosis compared to noncarriers is undefined. Studies on the mRNA suggest enhanced cleavage site recognition and a change in the location of the 3'‐cleavage/polyadenylation reaction, but no defined model has been proposed. The present study, based on proteomic investigation by two‐dimensional gel electrophoresis and electrospray ionization (ESI) tandem mass spectrometry (MS/MS) protein identification, suggests that the G20210A mutation is associated with increased glycosylation of prothrombin, which confers greater stability to the protein. Additionally, proteomic investigation of pooled plasma showed that expression levels of six spots, three of them identified by ESI MS/MS, were altered in subjects carrying the mutation, suggesting a possible cooperative effect in the thrombotic risk increment induced by the mutation.
Organic and polymer chemistry of electrophilic tri‐ and tetrasubstituted ethylenes
Authors: Hall H. K. , Padias Anne Buyle 
Published: April 2004

AbstractA survey of the spontaneous reactions of electrophilic olefins and nucleophilic olefins is presented as an area in which organic chemistry merges with polymer chemistry. The products include both small molecules and polymers, arising via tetramethylene biradical zwitterions that can cyclize or initiate polymerizations. Electrophilic tri‐ and tetrasubstituted olefins are particularly useful in delineating the transition from radical chemistry to ionic chemistry. A periodic table embodying these results enables predictions. Charge‐transfer complexes, although observed in many of these reactions, play no significant role. Various aspects arising from these investigations include new cationic initiators, Lewis acid catalysis, quinodimethane chemistry, and photochemistry. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2845–2858, 2004
Electrochemical behavior of high‐molecular‐weight poly(ferrocenylsilane) films in aqueous electrolyte solutions
Authors: Wang Xue‐Jie , Wang Li , Wang Jian‐Jun 
Published: April 2004

AbstractThe electrochemical behavior of high‐molecular‐weight poly(ferrocenyldimethylsilane) films and poly(ferrocenylmethylphenylsilane) films, which contained about 2.8 × 10−6 mol cm−2 ferrocene sites in eight kinds of aqueous electrolyte solutions, was investigated with cyclic voltammetry (CV). In some aqueous electrolyte solutions, the CV peak currents diminished gradually with an increase in the scanning times, whereas in other aqueous electrolyte solutions, stable and repeated cyclic voltammograms were obtained. The polymer films were poor‐solvent‐swollen in aqueous electrolyte solutions, and this resulted in a high resistivity of mass transfer and a slow rate of electrode reaction; therefore; quasireversible or irreversible CV processes were obtained. The kinetic parameters of the film‐electrode processes, such as the surface transfer coefficient, the apparent diffusion coefficient, and the standard rate constant for electron transfer, for the two films in aqueous LiClO4 solutions were measured, and the electrode process mechanism of the films was examined. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2245–2253, 2004
Nanoindentation and optical properties of poly(4,4′‐oxydiphenylene p‐phenylene pyromellitimide) copolyimide thin films according to the p‐phenylene diamine content
Authors: Lee Choonkeun , Iyer N. Padmanabha , Han Haksoo 
Published: April 2004

AbstractPoly(p‐phenylene pyromellitimide) (PMDA‐PDA), poly(oxydiphenylene pyromellitimide) (PMDA‐ODA), and poly(4,4′‐oxydiphenylene p‐phenylene pyromellitimide) random copolyimide thin films with different p‐phenylene diamine (PDA) contents were prepared. Nanoindentation was used to characterize the mechanical properties (hardness and modulus), and a prism coupler was used for measuring the optical properties (refractive index and birefringence). The hardness and modulus were calculated from curves of the nanoindentation load versus the displacement. The effect of the PDA content on the hardness and modulus was studied. The hardness of the polyimide thin films varied from 0.248 to 0.613 GPa, and the modulus varied from 3.78 to 6.75 GPa at a load of 0.127 mN. The hardness and modulus increased with increasing PDA content, whereas the penetration depth and plastic deformation decreased. As the load increased, the penetration depth increased. The hardness of PMDA‐ODA films remained constant, whereas that of PMDA‐PDA and PMDA‐ODA/PDA films decreased with increasing load. The in‐plane refractive index varied from 1.7219 to 1.8244, and the out‐of‐plane refractive index varied from 1.6390 to 1.5827, as a function of the PDA content. The birefringence varied with the PDA content from 0.0829 to 0.2417. The morphological structure of the prepared polyimide thin films was investigated with wide‐angle X‐ray diffraction. The mechanical properties and optical properties of the polyimide thin films were strongly dependent on the changes in the morphological structure, which originated from the variation of the composition. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2202–2214, 2004
Atomic force microscopy observations of the structural development during the uniaxial stretching of crosslinked low‐density polyethylene in partial and fully molten states
Authors: Koike Yutaka , Cakmak Miko 
Published: April 2004

AbstractThe effect of uniaxial deformation in partially and fully molten states on the morphology of crosslinked low‐density polyethylene has been investigated. At low temperatures, the morphology is predominantly fibrillar, with little kebabs appearing on the fibril surfaces. As the deformation temperature is increased into the melting range, the shish density decreases, and overgrowths of kebabs on the fibrils concurrently increase in length. This gives rise to added twisting of the kebabs reflected in the orientation factor analysis. This shish/twisted lamellar kebab texture is observed only in a partially molten state. Studies in a substantially molten state indicate the absence of shish, althugh short lamellae are observed that are oriented in the transverse direction. This morphology indicates a high chain orientation factor as a result of short lamellae that exhibit small twisting similar to Matsumura's rod model. The absence of shishes in the final films stretched isothermally in a substantially molten stage agrees with Schultz's model, in which imperfectly formed shishes dissolve if they are not stabilized by rapid cooling, as is the case in these studies. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2228–2237, 2004
Heterogeneous gene methylation patterns among pre‐invasive and cancerous lesions of the prostate: A histopathologic study of whole mount prostate specimens
Authors: Woodson Karen , Gillespie John , Hanson Jeffrey , Emmert‐Buck Mike , Phillips John M. , Linehan W. Marston , Tangrea Joseph A. 
Published: April 2004

AbstractBACKGROUNDGene methylation may contribute to prostate carcinogenesis through the silencing of gene transcription. We report on the methylation status of several genes shown to be silenced at different stages of progression using whole mount prostate specimens and laser capture microdissection. This is the first study to evaluate gene methylation patterns across multiple pre‐cancerous and invasive cancer foci from the same prostate gland.METHODSReal‐time PCR was used to evaluate methylation of five genes (GSTP1, RASSF1A, RARβ2, CD44, and EDNRB) across normal epithelium, high‐grade prostatic intraepithelial neoplasia (HGPIN), and multiple tumor foci from each of 11 prostate cancer patients.RESULTSGene methylation was not found in normal epithelium. To our knowledge, this is the first report of RASSF1A and RARβ2 methylation in HGPIN lesions (30% prevalence for each gene). In addition, RASSF1A, RARβ2, and GSTP1 methylation was highly prevalent in tumor foci (>75% for all three genes). Methylation of CD44 and EDNRB was observed in 41 and 38% of tumors but was not present in HGPIN.CONCLUSIONSThese data suggest that genes may be methylated at different points in the histopathologic progression of prostate cancer and these differences can be found in various histologic foci from the same gland. © 2004 Wiley‐Liss, Inc.
FGF17 is an autocrine prostatic epithelial growth factor and is upregulated in benign prostatic hyperplasia
Authors: Polnaszek Nathaniel , Kwabi‐Addo Bernard , Wang Jianghua , Ittmann Michael 
Published: April 2004

AbstractBACKGROUNDFibroblast growth factors (FGFs) are known to play an important role in the growth of prostatic epithelial cells. Benign prostatic hyperplasia (BPH) is characterized by increased epithelial and stromal proliferation within the transition zone of the prostate. FGF2, FGF7, and FGF9 are expressed in BPH tissue but expression of FGF17 has not been previously characterized in human prostate tissue.METHODSExpression of FGF17 in human prostate tissue and primary cultures of prostatic epithelial and stromal cells was determined by reverse‐transcriptase polymerase chain reaction (RT‐PCR). Growth response to FGF17 was assessed by addition of recombinant FGF17 to immortalized normal and neoplastic epithelial cell lines and primary cultures of prostatic stromal cells in the presence of insulin. Quantitative analysis of expression of FGF17 relative to keratin 18 and/or β‐actin in normal and hyperplastic prostate and prostate carcinoma was carried out by real‐time quantitative RT‐PCR.RESULTSFGF17 is expressed by prostatic epithelial cells and can act as an autocrine growth factor for immortalized and neoplastic prostatic epithelial cells. It can also promote stromal proliferation, although only at higher concentrations. Expression of FGF17 per epithelial cell was increased 2‐fold in BPH.CONCLUSIONSFGF17 is expressed by normal, hyperplastic, and neoplastic prostatic epithelial cells and can promote epithelial proliferation in an autocrine manner. FGF17 expression is increased 2‐fold in BPH and may contribute to the increased epithelial proliferation seen in this disease. © 2004 Wiley‐Liss, Inc.
A stability guaranteed active fault‐tolerant control system against actuator failures
Authors: Maki Midori , Jiang Jin , Hagino Kojiro 
Published: April 2004

AbstractIn this paper, a new strategy for fault‐tolerant control system design has been proposed using multiple controllers. The design of such controllers is shown to be unique in the sense that the resulting control system neither suffers from the problem of conservativeness of conventional passive fault‐tolerant control nor from the risk of instability associated with active fault‐tolerant control in case that an incorrect fault detection and isolation decision is made. In other words, the stability of the closed‐loop system is always ensured regardless of the decision made by the fault detection and isolation scheme. A correct decision will further lead to optimal performance of the closed‐loop system. This paper deals with the conflicting requirements among stability, redundancy, and graceful degradation in performance for fault‐tolerant control systems by using robust control techniques. A detailed design procedure has been presented with consideration of parameter uncertainties. Both total and partial actuator failures have been considered. This new control strategy has been demonstrated by controlling a McDonnell F‐4C airplane in the lateral‐direction through simulation. Copyright © 2004 John Wiley & Sons, Ltd.
High levels of the mitochondrial large ribosomal subunit protein 40 prevent loss of mitochondrial DNA in null mmf1 Saccharomyces cerevisiae cells
Authors: Accardi Rosita , Oxelmark Ellinor , Jauniaux Nicolas , de Pinto Vito , Marchini Antonio , Tommasino Massimo 
Published: April 2004

AbstractMembers of the YERO57c/YJGFc/UK114 protein family have been identified in bacteria and eukaryotes. The budding yeast Saccharomyces cerevisiae contains two different proteins of this family, Hmf1p and Mmf1p. We have previously shown that Mmf1p is a mitochondrial protein functionally related to its human homologue and able to influence the maintenance of mitochondrial DNA. Deletion of Mmf1 results in loss of the mitochondrial genome. Using a multicopy suppression approach, we have identified a protein of the mitochondrial large ribosomal subunit, MRPL40, which stabilizes mtDNA in Δmmf1 cells. Overexpression of MRPL40 did not prevent loss of mtDNA in a mutant strain lacking the mitochondrial protein Abf2p. Thus, MRPL40 does not have a general effect on mtDNA stability, but it may be specific for the mmf1‐null strain. We also show that the Δmrpl40 cells present a similar phenotype to the mmf1‐null strain, having reduced mtDNA stability and growth rate. Furthermore, we observed that ρ+Δmrpl40 haploid cells can be obtained when tetrads are directly dissected on medium containing a non‐fermentable carbon source. Thus, replication and segregation of the mtDNA can occur in the absence of MRPL40. We also show that another mitochondrial ribosomal protein, MRPL38, is able to overcome the Δmmf1‐associated defect. Together, our results suggest a link between Mmf1p and the two mitochondrial ribosomal proteins. Copyright © 2004 John Wiley & Sons, Ltd.