bluuebunny/crossref_metadata_2025 huggingface dataset:
Avaliação da eficácia das estratégias de posicionamento e do nível de atratividade setorial, do ponto de vista do acionista
Authors: Mello Rodrigo Bandeira de , Marcon Rosilene
Published: April 2009

Grande parte da literatura sobre estratégia competitiva ressalta, como principal objetivo empresarial, a obtenção de retornos acima da média. No Brasil, pesquisas empíricas que visam mensurar os retornos anormais setoriais e relacioná-los às questões estratégicas não têm recebido a atenção devida. Esta pesquisa, fundamentada principalmente na tradição da Organização Industrial, apresenta os resultados de um estudo exploratório e longitudinal, baseado em dados objetivos coletados no período de 1986 a 2001, que servem de parâmetros para avaliação da eficácia das estratégias de posicionamento das firmas e da atratividade setorial, para os acionistas, dos principais setores da economia brasileira. Por meio da construção de cenários de negócios bidimensionais (bidimensional landscapes), constatou-se que os setores de Siderurgia, Eletroeletrônicos, Veículos e Têxtil apresentaram retornos negativos, e que nenhum dos setores analisados criou valor para os acionistas quando se considerou como custo de capital o custo de oportunidade do acionista. Os dados também sugerem que as firmas que atuam nos setores de Papel e Celulose, Energia, Bancos, Telecomunicações e Construção têm menores probabilidades, quando comparados com os demais setores estudados, de conseguirem retornos anormais por meio de suas estratégias.
A importância do regime de estimativa de iss para a arrecadação tributária dos municípios brasileiros
Authors: Ozaki Marcos Takao , Biderman Ciro
Published: April 2009

Este artigo analisa alguns aspectos do regime de estimativa na arrecadação do Imposto Sobre Serviços de Qualquer Natureza (ISS). Na primeira parte analisa-se a importância da arrecadação própria dos municípios em função das mudanças institucionais dos anos 1990, sobretudo a Constituição Federal de 1988 e a Lei de Responsabilidade Fiscal de 2000. Em seguida discute-se a importância dos serviços como fonte de arrecadação e o papel que o regime de estimativas em particular ou a simplificação administrativa em geral podem ter na cobrança deste imposto. A terceira parte do artigo apresenta três estudos de caso. Em dois deles (São Paulo e Vitória da Conquista) mostra-se como o regime de estimativa pode ajudar na arrecadação, enquanto o terceiro caso serve como contrafactual, mostrando que o regime de estimativa não é nenhuma panacéia. A última seção discute alguns aspectos legais e de finanças públicas que concernem ao ISS. Finalmente, apresentam-se algumas conclusões.
Driving forces of the diel distribution of phytoplankton functional groups in a shallow tropical lake (Lake Monte Alegre, Southeast Brazil)
Authors: Rangel LM. , Silva LHS. , Arcifa MS. , Perticarrari A.
Published: April 2009

Phytoplankton vertical and diel dynamics in a small shallow lake (Lake Monte Alegre, Ribeirão Preto, state of São Paulo) were investigated in two climatological periods: July 2001 (cool-dry season) and March 2002 (warm-rainy season). Monte Alegre is a eutrophic reservoir, with a warm polymictic discontinuous circulation pattern. The lake was thermally stratified in both periods, although dissolved oxygen varied less in the cool-dry period. Phytoplankton biomass was higher in the warm-rainy season and the vertical distribution was stratified in both seasons. Flagellate groups (Lm, Y, W1 and W2) and functional groups typical of shallow eutrophic environments (J, X1 and Sn) were important throughout the study period. The lake's thermal pattern strongly influenced the vertical distribution of the phytoplankton community in both periods. Biomass, functional groups and size classes of phytoplankton also were determined by the presence of more efficient herbivores in the lake, especially during the cool-dry period when phytoplankton biomass decreased.
Removal of algal blooms in freshwater using magnetic polymer
Authors: Liu Dan , Li Fengting , Zhang Bingru
Published: April 2009

Removal of algal blooms in freshwater using magnetic polymer was studied by magnetic field. Results showed that magnetic polymer at optimal loadings (4 mg/Lferroferric oxide modified with 1.6 mg/Lchitosan) could remove over 99% algal cells; meanwhile, the removal efficiency of COD, total nitrogen and phosphorus was found to be 85.0%, 73.9% and 28.7% respectively. Furthermore, effects of ionic strength, pH and cell concentration on the removal of algal cells were analyzed: ionic strength had a negative effect on the removal efficiency which increased with the increase of cell concentration and reached a maximum at pH 7.0.
Preparation of hydrophobic PVDF hollow fiber membranes for desalination through membrane distillation
Authors: Hou Deyin , Wang Jun , Qu Dan , Luan Zhaokun , Zhao Changwei , Ren Xiaojing
Published: April 2009

Fabrication of polyvinylidene fluoride (PVDF) hydrophobic asymmetric hollow fiber membranes was studied by introducing inorganic salt LiCl and water soluble polymer polyethylene glycol (PEG) 1500, using N,N-dimethylacetamide (DMAc) as solvent and tap water as the coagulation medium. The membranes properties also were tested and characterized. It is found that the non-solvent additive can increase membranes porosity, ether LiCl or PEG 1500. Because of the addition of PEG 1500, the PVDF membranes obtained a rough topography on the membrane surface and the contact angle of the PVDF membranes increased to 113.50° compared to 89.82° of the PVDF membranes spun without an additive. During direct contact membrane distillation (DCMD) of 0.6 M sodium chloride solution, the PVDF membranes spun with PEG 1500 as a non-solvent additive achieved higher water permeation flux compared to the membranes spun from PVDF/DMAc and PVDF/DMAC/LiCl dopes, but the latter two membranes exhibited higher salt rejection rate.
Fluid flow pattern and water residence time in waste stabilisation ponds
Authors: Badrot-Nico F. , Guinot V. , Brissaud F.
Published: April 2009

As treatment processes are kinetic-dependent, a consistent description of water residence times is essential to the prediction of waste stabilization ponds performance. A physically-based 3D transient CFD model simulating the water velocity, temperature and concentration fields as a function of all influent meteorological factors – wind speed and direction, solar radiation, air temperature and relative humidity – was used to identify the relationships between the meteorological conditions and the hydrodynamic patterns and water residence times distributions in a polishing pond. The required meteorological data were recorded on site and water temperatures recorded at 10 sampling sites for 141 days. Stratification events appear on very calm days for wind speeds lower than 3 m s−1 and on sunny days for wind speeds lower than 5 m s−1. De-stratification is related to two mixing processes: nightly convection cells and global mixing patterns. Numerical tracer experiments show that the results of the flow patterns can be evaluated using the dispersed flow regime approximation and, for wind speeds exceeding 6 m s−1, the completely stirred tank reactor assumption.
A stochastic approach for automatic generation of urban drainage systems
Authors: Möderl M. , Butler D. , Rauch W.
Published: April 2009

Typically, performance evaluation of new developed methodologies is based on one or more case studies. The investigation of multiple real world case studies is tedious and time consuming. Moreover extrapolating conclusions from individual investigations to a general basis is arguable and sometimes even wrong. In this article a stochastic approach is presented to evaluate new developed methodologies on a broader basis. For the approach the Matlab-tool “Case Study Generator” is developed which generates a variety of different virtual urban drainage systems automatically using boundary conditions e.g. length of urban drainage system, slope of catchment surface, etc. as input. The layout of the sewer system is based on an adapted Galton-Watson branching process. The sub catchments are allocated considering a digital terrain model. Sewer system components are designed according to standard values. In total, 10,000 different virtual case studies of urban drainage system are generated and simulated. Consequently, simulation results are evaluated using a performance indicator for surface flooding. Comparison between results of the virtual and two real world case studies indicates the promise of the method. The novelty of the approach is that it is possible to get more general conclusions in contrast to traditional evaluations with few case studies.
COPING STYLES OF ALCOHOL-DEPENDENT INDIVIDUALS: COMPARISON WITH DEPRESSED PATIENTS AND CONTROLS
Authors: Paparrigopoulos Thomas , Liappas John , Tzavellas Elias , Soldatos Constantin
Published: April 2009

The profile of coping mechanisms in a sample of 164 subjects (60 alcohol-dependent individuals, 47 depressed patients, 57 controls) was investigated. Data were collected over the period January-December 2004, at the Eginition Psychiatric Hospital of the Athens University Medical School
in Athens, capital of Greece. The Albert Einstein College of Medicine Coping Styles Questionnaire (AECOM-CSQ; Plutchik & Conte, 1989), and the Hamilton Depression and Anxiety Rating Scales (Hamilton, 1959, 1960) were used for the assessment. Post hoc analysis of variance for comparisons
between groups and logistic regressions using coping styles as predictor variables for group classification were used for data analysis. The main findings were that alcohol-dependent individuals could be distinguished from either depressed or control subjects on the ground of their coping
mechanisms with stress, and that men and women use different patterns of psychological adaptation. More specifically, group classification in terms of specific coping styles could be predicted with an overall accuracy of more than 84%; in men, classification related to the coping mechanism
of substitution, and in women to blame, reversal, and substitution. These findings may have implications for individually tailored psychotherapeutic interventions in alcohol-dependent individuals.
GENDER DIFFERENCES AND COLOR: CONTENT AND EMOTION OF WRITTEN DESCRIPTIONS
Authors: Arthur Heather , Johnson Gail , Young Adena
Published: April 2009

In this study gender language differences in the written description of color were analyzed. The total number of words used, number of tertiary level terms used, and normative emotionality were assessed. Women were found to use more words to describe color than men. An interaction effect
among gender and age was found for the number of tertiary level words used. A main effect of gender for total mean emotionality was found that was not ameliorated by age or education level.
HUMOR STYLES IN PREDICTING LONELINESS AMONG TURKISH UNIVERSITY STUDENTS
Authors: Çeçen A. Rezan
Published: April 2009

The purpose of this investigation was two-fold. Firstly, to examine whether there were significant correlations between loneliness and four humor styles, and secondly to examine which humor style was the best predictor of loneliness among university students. In this study 483 undergraduate
students participated at Çukurova University, Turkey. Data were collected through the Revised UCLA Loneliness Scale (Russell, Peplau, & Cutrona, 1980) and the Humor Styles Questionnaire (Martin, Puhlik-Doris, Larsen, Gray, & Weir, 2003). Four Pearson product-moment correlations
were computed for the scores on the Revised UCLA Loneliness Scale and on each of four humor scales. The results provided evidence in support of a conceptual framework of humor styles and loneliness indicating strong negative correlations between loneliness and affiliative and self-enhancing
humor, and moderate positive correlations between loneliness and self-defeating humor, but no significant correlations between loneliness and aggressive humor. The stepwise regression analysis results indicated that four variables contributed meaningfully to loneliness, and the affiliative
humor style was the best predictor of loneliness.
ILLNESS TRANSMISSION MODE AND PERCEIVER PERSONALITY: FACTORS AFFECTING STIGMATIZED PERCEPTIONS OF PATIENTS AND SEXUAL ILLNESS
Authors: Smith Gabie E. , Nave Christopher S.
Published: April 2009

Past field research has demonstrated the devastating impact of illness stigma on patient populations; experimental studies have identified specific illness characteristics that influence stigmatization and social rejection of patients. The current study used a quasi-experimental design
to investigate the influence of participant erotophobia-erotophilia (Fisher, Byrne, & White, 1983) and illness transmission (nonsexual, sexual) on perceptions of illness and patients. Sexual illness transmission led to significantly more negative perceptions of the illness and patient.
A significant Erotophobia-Erotophilia x Nonsexual-Sexual Transmission interaction influenced participants' social rejection of the patient. Specifically, erotophobes socially rejected patients with the sexually transmitted illness more than patients with the nonsexual illness.
MINI-MAX MODEL OF MOTIVATION: AN INITIAL PRESENTATION
Authors: Pedersen Darhl M.
Published: April 2009

A cost/benefit motivational model is presented based on the discrepancy between a benefits equals costs line and a negatively accelerated performance curve. The model posits that people attempt to maximize benefits while minimizing costs and that the critical point is where the
lines cross. Performance increments beyond that point are seen as not cost effective. It was proposed that high achievers expend additional effort in spite of a lower benefits to costs ratio, whereas low achievers do not. In an application of the model, 119 college students (47 men and 72
women) were studied. Those who remained in a 2.5 hour long class session following an examination administered in the first 45 minutes had significantly higher achievement in the course than did those who left.
Next Generation Digital Commerce Technologies
Authors: Al-Ani Muzhir Shaban
Published: April 2009

This paper deals with the demonstration of commerce technologies and concentration on the next generation technologies. The development of high advance technologies in telecommunications such as internet and mobile telephony leads to massive support for digital commerce. The main feature of the third generation mobile internet protocol addressing introduced an access to the internet through mobile. The trends of next generation digital commerce try to overcome all the commercial problems and to develop a fast secure and intelligent commerce depending on the high performance next generation technologies.
Enrichment of Human CD4+ Vα24/Vβ11 Invariant NKT Cells in Intrahepatic Malignant Tumors
Authors: Bricard Gabriel , Cesson Valerie , Devevre Estelle , Bouzourene Hanifa , Barbey Catherine , Rufer Nathalie , Im Jin S. , Alves Pedro M. , Martinet Olivier , Halkic Nermin , Cerottini Jean-Charles , Romero Pedro , Porcelli Steven A. , MacDonald H. Robson , Speiser Daniel E.
Published: April 2009

Invariant NKT cells (iNKT cells) recognize glycolipid Ags via an invariant TCR α-chain and play a central role in various immune responses. Although human CD4+ and CD4− iNKT cell subsets both produce Th1 cytokines, the CD4+ subset displays an enhanced ability to secrete Th2 cytokines and shows regulatory activity. We performed an ex vivo analysis of blood, liver, and tumor iNKT cells from patients with hepatocellular carcinoma and metastases from uveal melanoma or colon carcinoma. Frequencies of Vα24/Vβ11 iNKT cells were increased in tumors, especially in patients with hepatocellular carcinoma. The proportions of CD4+, double negative, and CD8α+ iNKT cell subsets in the blood of patients were similar to those of healthy donors. However, we consistently found that the proportion of CD4+ iNKT cells increased gradually from blood to liver to tumor. Furthermore, CD4+ iNKT cell clones generated from healthy donors were functionally distinct from their CD4− counterparts, exhibiting higher Th2 cytokine production and lower cytolytic activity. Thus, in the tumor microenvironment the iNKT cell repertoire is modified by the enrichment of CD4+ iNKT cells, a subset able to generate Th2 cytokines that can inhibit the expansion of tumor Ag-specific CD8+ T cells. Because CD4+ iNKT cells appear inefficient in tumor defense and may even favor tumor growth and recurrence, novel iNKT-targeted therapies should restore CD4− iNKT cells at the tumor site and specifically induce Th1 cytokine production from all iNKT cell subsets.
Trimolecular Complex Formation of IgE, FcεRI, and a Recombinant Nonanaphylactic Single-Chain Antibody Fragment with High Affinity for IgE
Authors: Lupinek Christian , Roux Kenneth H. , Laffer Sylvia , Rauter Ingrid , Reginald Kavita , Kneidinger Michael , Blatt Katharina , Ball Tanja , Pree Ines , Jahn-Schmid Beatrice , Allam Jean-Pierre , Novak Natalija , Drescher Anja , Kricek Franz , Valent Peter , Englund Hakan , Valenta Rudolf
Published: April 2009

IgE is a central molecule in allergic disease. We have isolated cDNAs coding for the heavy and light chains of a murine mAb specific to human IgE and expressed a recombinant single-chain variable fragment (ScFv) derived thereof in Escherichia coli. The purified recombinant ScFv has a molecular mass of 28 kDa as measured by mass spectrometry and shows a β-sheet fold as determined by circular dichroism. In biosensor-based studies it was demonstrated that the ScFv rapidly and stably binds to human IgE with an affinity of KD of 1.52 × 10−10 M, which is almost as high as the affinity of IgE for FcεRI, and that the ScFv is able to recognize FcεRI-bound IgE and to prevent IgE binding to FcεRI. The ScFv reacts specifically with IgE but not with other isotypes, allows the measurement of allergen-specific IgE in serum samples, and specifically targets cells that contain FcεRI- or FcεRII-bound IgE or that secrete IgE. Using negative-stain electron microscopy we demonstrated the formation of bimolecular complexes consisting of two ScFv molecules and one IgE and trimolecular complexes consisting of IgE, FcεRI, and ScFv in which only one ScFv is able to bind to IgE. Accordingly, we found that the ScFv does not cross-link basophil-bound IgE and hence does not induce histamine release or activation of basophils as demonstrated by FACS analysis of CD203c expression and by histamine release experiments. In vivo skin testing confirmed the lack of allergenic activity of the ScFv. The recombinant ScFv may represent a universal tool for the IgE-targeted treatment of allergies.
The NF-κB RelA Subunit Confers Resistance toLeishmania majorby Inducing Nitric Oxide Synthase 2 and Fas Expression but Not Th1 Differentiation
Authors: Mise-Omata Setsuko , Kuroda Etsushi , Sugiura Tsutomu , Yamashita Uki , Obata Yuichi , Doi Takahiro S.
Published: April 2009

Although the NF-κB transcription factors participate in both innate and adaptive immune responses, little is known about the role of the RelA subunit because mice lacking the rela gene die at embryonic day 14. To elucidate the role of RelA in Leishmania major infection, we prepared fetal liver chimeric mice by adoptively transferring embryonic day 13.5 rela−/− or rela+/+ fetal liver into lethally irradiated host mice. About 90% of the peripheral lymphocytes of the chimeric mice had differentiated from rela fetal liver cells. The rela−/− fetal liver chimeric mice were highly sensitive to infection with L. major and died within 11 wk after infection. Despite the severity of the disease, parasite Ag-reactive Th1 cells developed normally. The rela−/− macrophages were less able to control intracellular parasite replication than rela+/+ macrophages, despite showing equally efficient phagocytosis. Both in vitro NO production of macrophages and in vivo expression of NO synthase 2 in the lesions and draining lymph nodes was reduced in rela−/− fetal liver chimeric mice. Moreover, up-regulation of Fas in rela−/− macrophages was impaired both after in vitro stimulation with LPS and after in vivo infection with L. major, implying a defect in their ability to eliminate infected cells. Thus, RelA is necessary for macrophages to be resistant to intracellular parasite infection.
Early Infection Termination Affects Number of CD8+ Memory T Cells and Protective Capacities in Listeria monocytogenes-Infected Mice upon Rechallenge
Authors: Tseng Kuo-En , Chung Cheng-Yu , H’ng Weng Siong , Wang Shih-Lien
Published: April 2009

Here, we reevaluate the effects of early termination of infection on primary T cell expansion, subsequent memory cell development, and protective immunity. Using a murine Listeria monocytogenes (LM) infection model, we found the primary expansions of both CD4+ and CD8+ T cells were affected even when ampicillin was given as late as 60 h postinfection (p.i.). Subsequent development of CD8+ memory T cells was also impaired, although to a lesser extent, and only mice that received ampicillin at 24 h p.i. revealed a significant decrease in memory CD8+ T cells. Upon rechallenge with 1 × 105 CFU of LM, all ampicillin-treated mice cleared LM as effectively, and they generated similar amounts of Ag-specific CD8+ T cells as with untreated mice. However, mice that received ampicillin at 24 h p.i. lost their protective abilities when rechallenged with 7.5 × 105 CFU of LM. Ampicillin treatment also revealed early down-regulation of B7.1 and B7.2, but not CD40, on dendritic cells 72 h p.i. Our results have several important implications: 1) they argue against the hypothesis that brief exposure of T cells to an Ag is sufficient for full-fledged primary T cell responses and subsequent memory T cell development in vivo; 2) they suggest the existence of a reservoir of memory T cells, more than the immune system can possibly expand during secondary infection; and 3) they suggest that protective capacity is correlated with the number of preexisting memory T cells and that secondary expanding T cells play a limited role, at least in murine LM infection.
Early Hematopoietic Zinc Finger Protein Prevents Tumor Cell Recognition by Natural Killer Cells
Authors: La Rocca Rosanna , Fulciniti Mariateresa , Lakshmikanth Tadepally , Mesuraca Maria , Ali Talib Hassan , Mazzei Valerio , Amodio Nicola , Catalano Lucio , Rotoli Bruno , Ouerfelli Ouathek , Grieco Michele , Gulletta Elio , Bond Heather M. , Morrone Giovanni , Ferrone Soldano , Carbone Ennio
Published: April 2009

Early hematopoietic zinc finger/zinc finger protein 521 (EHZF/ZNF521) is a novel zinc finger protein expressed in hematopoietic stem and progenitor cells and is down-regulated during their differentiation. Its transcript is also abundant in some hematopoietic malignancies. Analysis of the changes in the antigenic profile of cells transfected with EHZF cDNA revealed up-regulation of HLA class I cell surface expression. This phenotypic change was associated with an increased level of HLA class I H chain, in absence of detectable changes in the expression of other Ag-processing machinery components. Enhanced resistance of target cells to NK cell-mediated cytotoxicity was induced by enforced expression of EHZF in the cervical carcinoma cell line HeLa and in the B lymphoblastoid cell line IM9. Preincubation of transfected cells with HLA class I Ag-specific mAb restored target cell susceptibility to NK cell-mediated lysis, indicating a specific role for HLA class I Ag up-regulation in the NK resistance induced by EHZF. A potential clinical significance of these findings is further suggested by the inverse correlation between EHZF and MHC class I expression levels, and autologous NK susceptibility of freshly explanted multiple myeloma cells.
Evolution of the Ikaros Gene Family: Implications for the Origins of Adaptive Immunity
Authors: John Liza B. , Yoong Simon , Ward Alister C.
Published: April 2009

Members of the Ikaros family of transcription factors are important for immune system development. Analysis of Ikaros-related genes from a range of species suggests the Ikaros family derived from a primordial gene, possibly related to the present-day protostome Hunchback genes. This duplicated before the divergence of urochordates to produce two distinct lineages: one that generated the Ikaros factor-like (IFL) 2 genes of urochordates/lower vertebrates and the Pegasus genes of higher vertebrates, and one that generated the IFL1 genes of urochordates/lower vertebrates, the IKFL1 and IKFL2 genes of agnathans and the remaining four Ikaros members of higher vertebrates. Expansion of the IFL1 lineage most likely occurred via the two intervening rounds of whole genome duplication. A proposed third whole genome duplication in teleost fish produced a further increase in complexity of the gene family with additional Pegasus and Eos members. These findings question the use of IFL sequences as evidence for the existence of adaptive immunity in early chordates and vertebrates. Instead, this study is consistent with a later emergence of adaptive immunity coincident with the appearance of the definitive lymphoid markers Ikaros, Aiolos, and Helios.
Selective Transcriptional Down-Regulation of Human Rhinovirus-Induced Production of CXCL10 from Airway Epithelial Cells via the MEK1 Pathway
Authors: Zaheer Raza S. , Koetzler Rommy , Holden Neil S. , Wiehler Shahina , Proud David
Published: April 2009

Human rhinovirus (HRV) infections can trigger exacerbations of lower airway diseases. Infection of airway epithelial cells induces production of a number of proinflammatory chemokines that may exacerbate airway inflammation, including CXCL10, a chemoattractant for type 1 lymphocytes and NK cells. Primary human bronchial epithelial cells and the BEAS-2B human bronchial epithelial cell line were used to examine the role of MAPK pathways in HRV-16-induced production of CXCL10. Surprisingly, PD98059 and U0126, two inhibitors of the MEK1/2-ERK MAPK pathway, significantly enhanced HRV-16-induced CXCL10 mRNA and protein. This enhancement was not seen with IFN-β-induced production of CXCL10. Studies using small interfering RNA revealed that knockdown of MEK1, but not MEK2, was associated with enhanced HRV-induced CXCL10 production. Promoter construct studies revealed that PD98059 and U0126 enhanced HRV-16-induced transcriptional activation of CXCL10. HRV-16-induced promoter activation was regulated by two NF-κB binding sites, κB1 and κB2, and by an IFN-stimulated response element. Inhibitors of the MEK1/2-ERK pathway did not alter HRV-16-induced activation of tandem repeat κB1 or κB2 constructs, nor did they alter HRV-16-induced nuclear translocation/binding of NF-κB to either κB1 or κB2 recognition sequences. Furthermore, PD98059 and U0126 did not alter phosphorylation or degradation of IκBα. In contrast, inhibitors of the MEK1/2-ERK pathway, and small interfering RNA knockdown of MEK1, enhanced nuclear translocation/binding of IFN regulatory factor (IRF)-1 to the IFN-stimulated response element recognition sequence in HRV-16 infected cells. We conclude that activation of MEK1 selectively down-regulates HRV-16-induced expression of CXCL10 via modulation of IRF-1 interactions with the gene promoter in human airway epithelial cells.
Inducible MHC Class II Expression by Mast Cells Supports Effector and Regulatory T Cell Activation
Authors: Kambayashi Taku , Allenspach Eric J. , Chang John T. , Zou Tao , Shoag Jonathan E. , Reiner Steven L. , Caton Andrew J. , Koretzky Gary A.
Published: April 2009

In addition to their well-established role as regulators of allergic response, recent evidence supports a role for mast cells in influencing the outcome of physiologic and pathologic T cell responses. One mechanism by which mast cells (MCs) influence T cell function is indirectly through secretion of various cytokines. It remains unclear, however, whether MCs can directly activate T cells through Ag presentation, as the expression of MHC class II by MCs has been controversial. In this report, we demonstrate that in vitro stimulation of mouse MCs with LPS and IFN-γ induces the expression of MHC class II and costimulatory molecules. Although freshly isolated peritoneal MCs do not express MHC class II, an in vivo inflammatory stimulus increases the number of MHC class II-positive MCs in situ. Expression of MHC class II granted MCs the ability to process and present Ags directly to T cells with preferential expansion of Ag-specific regulatory T cells over naive T cells. These data support the notion that, in the appropriate setting, MCs may regulate T cell responses through the direct presentation of Ag.
Selective Requirement for c-Myc at an Early Stage of Vα14i NKT Cell Development
Authors: Mycko Marcin P. , Ferrero Isabel , Wilson Anne , Jiang Wei , Bianchi Teresa , Trumpp Andreas , MacDonald H. Robson
Published: April 2009

Vα14 invariant (Vα14i) NKT cells are a subset of regulatory T cells that utilize a semi-invariant TCR to recognize glycolipids associated with monomorphic CD1d molecules. During development in the thymus, CD4+CD8+ Vα14i NKT precursors recognizing endogenous CD1d-associated glycolipids on other CD4+CD8+ thymocytes are selected to undergo a maturation program involving sequential expression of CD44 and NK-related markers such as NK1.1. The molecular requirements for Vα14i NKT cell maturation, particularly at early developmental stages, remain poorly understood. In this study, we show that CD4-Cre-mediated T cell-specific inactivation of c-Myc, a broadly expressed transcription factor with a wide range of biological activities, selectively impairs Vα14i NKT cell development without perturbing the development of conventional T cells. In the absence of c-Myc, Vα14i NKT cell precursors are blocked at an immature CD44lowNK1.1− stage in a cell autonomous fashion. Residual c-Myc-deficient immature Vα14i NKT cells appear to proliferate normally, cannot be rescued by transgenic expression of BCL-2, and exhibit characteristic features of immature Vα14i NKT cells such as high levels of preformed IL-4 mRNA and the transcription factor promyelocytic leukemia zinc finger. Collectively our data identify c-Myc as a critical transcription factor that selectively acts early in Vα14i NKT cell development to promote progression beyond the CD44lowNK1.1− precursor stage.
Group V Secretory Phospholipase A2 Modulates Phagosome Maturation and Regulates the Innate Immune Response against Candida albicans
Authors: Balestrieri Barbara , Maekawa Akiko , Xing Wei , Gelb Michael H. , Katz Howard R. , Arm Jonathan P.
Published: April 2009

Phospholipase A2 (PLA2) hydrolyzes the sn-2 position of cell membrane phospholipids to release fatty acids and lysophospholipids. We have previously reported that group V secretory PLA2 (sPLA2) translocates from the Golgi and recycling endosomes of mouse peritoneal macrophages to newly formed phagosomes and regulates the phagocytosis of zymosan, suggesting a role in innate immunity. Here we report that in macrophages lacking group V sPLA2, phagosome maturation was reduced 50–60% at early time points while the binding of zymosan was unimpaired. The ability of group V sPLA2 to regulate phagocytosis extended to phagocytosis of IgG- and complement-opsonized sheep RBC. Moreover, macrophages lacking group V sPLA2 had delays in phagocytosis, phagosome maturation, and killing of Candida albicans. Cytokine production and eicosanoid generation were not impaired by the lack of group V sPLA2. Furthermore, in a model of systemic candidiasis, mice lacking group V sPLA2 had an increased fungal burden in the kidney, liver, and spleen at day 7 postinfection and increased mortality. Thus, group V sPLA2 regulates phagocytosis through major phagocytic receptors and contributes to the innate immune response against C. albicans by regulating phagocytosis and killing through a mechanism that is likely dependent on phagolysosome fusion.
Adaptive Immune Response in JAM-C-Deficient Mice: Normal Initiation but Reduced IgG Memory
Authors: Zimmerli Claudia , Lee Boris P. L. , Palmer Gaby , Gabay Cem , Adams Ralf , Aurrand-Lions Michel , Imhof Beat A.
Published: April 2009

We have recently shown that junctional adhesion molecule (JAM)-C-deficient mice have leukocytic pulmonary infiltrates, disturbed neutrophil homeostasis, and increased postnatal mortality. This phenotype was partially rescued when mice were housed in ventilated isolators, suggesting an inability to cope with opportunistic infections. In the present study, we further examined the adaptive immune responses in JAM-C−/− mice. We found that murine conventional dendritic cells express in addition to Mac-1 and CD11c also JAM-B as ligand for JAM-C. By in vitro adhesion assay, we show that murine DCs can interact with recombinant JAM-C via Mac-1. However, this interaction does not seem to be necessary for dendritic cell migration and function in vivo, even though JAM-C is highly expressed by lymphatic sinuses of lymph nodes. Nevertheless, upon immunization and boosting with a protein Ag, JAM-C-deficient mice showed decreased persistence of specific circulating Abs although the initial response was normal. Such a phenotype has also been observed in a model of Ag-induced arthritis, showing that specific IgG2a Ab titers are reduced in the serum of JAM-C−/− compared with wild-type mice. Taken together, these data suggest that JAM-C deficiency affects the adaptive humoral immune response against pathogens, in addition to the innate immune system.
Enhancement of the surface and bulk mechanical properties of polystyrene through the incorporation of raw multiwalled nanotubes with the twin‐screw mixing technique
Authors: Liu Sung‐Po , Hsu Wei‐Lun , Chang Kung‐Chin , Yeh Jui‐Ming
Published: April 2009

In this article, we present the effects of incorporated multiwalled nanotubes (MWNTs) on a metal surface and the bulk mechanical properties of as‐synthesized polystyrene (PS)–MWNT composites prepared with the twin‐screw mixing technique. The MWNTs used for preparing the composites were raw compounds that were not treated with any surface modifications. The morphology for the dispersion capability of the MWNTs in the PS matrix was subsequently characterized with transmission electron microscopy. Surface mechanical property studies (i.e., wear resistance and hardness) showed that the integration of MWNTs led to a distinct increase in the wear resistance and also the micro/nanohardness with up to a 5 wt % MWNT loading in the composites. Moreover, the enhancement of the wear resistance of the as‐prepared composites, in comparison with pure PS, was further identified with scanning electron microscopy observations of the surface morphology after testing. On the other hand, for bulk mechanical property studies (i.e., the tensile strength and flexural strength), the composites containing a 3 wt % concentration of MWNTs in the PS matrix exhibited the best performance with respect to the tensile strength and flexural strength. This means that this composition of MWNTs exhibited good compatibility with the PS matrix, and this can be attributed to the π–π interacting forces existing between the aromaticity of the MWNTs and PS matrix. Furthermore, at higher MWNT loadings (e.g., 5 wt %), raw MWNTs were aggregated in the polymer matrix, as observed by transmission electron microscopy. Also, this led to an obvious decrease in the tensile strength and flexural strength. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Methylolation of melamine with incipient condensation. II. Mathematical modeling
Authors: Nicolau V. V. , Estenoz D. A. , Meira G. R.
Published: April 2009

A novel mathematical model is presented for the reaction between melamine (M) and formaldehyde (F) at pH = 9.0 and at temperatures between 38 and 90°C. It is based on a kinetic scheme that includes reversible methylolations, irreversible formation of (unsubstituted) methylene bridges, reversible formation of (unsubstituted) ether bridges, instantaneous dissolution of M, and instantaneous equilibrium for the hydration/dehydration of F. The model predicts the distributions of molecular weights and functionalities of the evolving MF resin. Arrhenius expressions were adjusted for the seven kinetic constants on the basis of measurements reported in the first part of this series. Even though the final products contain thousands of different molecular species, 21 of them constitute more than 90% of the total weights. During the initial period with negligible condensation, the undissolved M distorts the distributions of molecular weights and functionalities; but the reversibility of methylolations corrects for such distortion prior to the effective start of condensation. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Ionic liquid‐H2O Resulting in a Highly Chemoselective Oxidation of Benzylic Alcohols in the Presence of Aliphatic Analogues Catalyzed by Immobilized TEMPO
Authors: HU Ruijun , LEI Ming , WEI Hegeng , WANG Yanguang
Published: April 2009

In ionic liquid 1‐butyl‐3‐methylimidazolium hexafluorophosphate ([bmim][PF6])‐H2O, a highly chemoselective oxidation of benzylic alcohols in the presence of aliphatic ones to the corresponding hydroxyl benzyl aldehydes and ketones was allowed in high yields using N‐chlorosuccinimide (NCS)/NaBr/IL‐TEMPO (ionic liquid immobilized 2,2,6,6‐tetramethylpiperidine‐1‐oxyl) as a facile and effective catalytic oxidation system. The medium, [bmim][PF6], together with the catalyst IL‐TEMPO could be easily recycled for ten runs without any influence on the efficacy of the reaction in terms of yield and selectivity of the product.
Titanium dioxide nanotubes enhance bone bonding in vivo
Authors: Bjursten Lars M. , Rasmusson Lars , Oh Seunghan , Smith Garrett C. , Brammer Karla S. , Jin Sungho
Published: April 2009

Implant topography is critical to the clinical success of bone‐anchored implants, yet little is known how nano‐modified implant topography affects osseointegration. We investigate the in vivo bone bonding of two titanium implant surfaces: titanium dioxide (TiO2) nanotubes and TiO2 gritblasted surfaces. In previous in vitro studies, the topography of the TiO2 nanotubes improved osteoblast proliferation and adhesion compared with gritblasted titanium surfaces. After four weeks of implantation in rabbit tibias, pull‐out testing indicated that TiO2 nanotubes significantly improved bone bonding strength by as much as nine‐fold compared with TiO2 gritblasted surfaces. Histological analysis confirmed greater bone‐implant contact area, new bone formation, and calcium and phosphorus levels on the nanotube surfaces. It is anticipated that further studies will contribute to a better understanding of the effect of implant nanotopography on in vivo bone formation and bonding strength. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Picryl derivatives of benzo[1,2‐d:4,5‐d′]bistriazole and benzo[1,2‐d:4,5‐d′]bistriazole‐4,8‐dione
Authors: Berlin Jane K. , Coburn Michael D.
Published: April 2009

In a previous communication from this laboratory it was reported that benzotriazole reacts with both picryl chloride and picryl fluoride to give 1‐picrylbenzotriazole exclusive of any 2‐picrylbenzotriazole (3). As an extension of this study we have examined the reactions of benzo[1,2‐d:4,5‐d′]bistriazole (I) and benzo[1,2‐d:4,5‐d′]bistriazole‐4,8‐dione (II) with picryl fluoride.
Aminoacid and protein conjugates with biologically active purines
Authors: Vidal‐Gomez J. , Greenbaum J. H. , Giner‐Sorolla A.
Published: April 2009

Condensation products of amino acids and proteins with biologically active purines have been obtained to study their potential tumor inhibitory activity and as models for the preparation of conjugates with tumor specific antibodies. Among the new compounds are 2‐glycinyl‐6‐methylmercaptopurine (5), 2‐glycinyl‐6‐mercaptopurine (6), 2‐glycinyl‐6‐chloropurine (16), 2‐glycinyl‐6‐hydroxylaminopurine (18), 2‐glycinylpurine (8) and 2‐glycinyl‐6‐methylpurine (7). 9‐Alkylpurines led to new purine derivatives, such as 6‐chloro‐9H‐purine‐9‐acetic acid (22) and 6‐hydroxylamino‐9H‐purine‐9‐acetylhydroxamic acid (23). These derivatives were coupled to bovine serum albumin (BSA) to yield conjugates. The amino acid‐purines 6‐cysteinyl (27) and 6‐glutathionyl‐S‐purine 3‐oxide (28) were obtained from 6‐chloropurine 3‐oxide (26). Other protein‐purine 3‐oxide conjugates were obtained with 6‐mercaptopurine 3‐oxide (29) and 6‐bromomethylpurine 3‐oxide (33).
The reduction of l‐methyl‐3‐methoxy‐5‐arylpyrrole‐2‐ and ‐4‐carboxylic esters with selected reducing agents
Authors: Campaigne E. , Shutske G. M.
Published: April 2009

Three new rnethoxypyrrole esters, ethyl 1‐methyl‐3‐methoxy‐5‐phenylpyrrole‐2‐earboxylate, diethyl l‐methyl‐3‐methoxy‐5‐phenylpyrrole‐2,4‐diearboxylate, and ethyl l‐methyl‐2‐phenyl‐4‐methoxypyrrole‐3‐carboxylate were reduced with diborane/tetrahydrofuran, lithium aluminum hydride, and some related reducing agents. In each case diborane reduced the ethoxycarbonyl group to a methyl group and lithium aluminum hydride reduced it to a hydroxymethyl group.
Solvent effects in the reaction of 2‐thiophenesulfonyl chloride with aniline
Authors: Arcoria Antonino , Maccarone Emanuele , Tomaselli Gaetano A. , Calí Rosario , Currieri Salvatore
Published: April 2009

The second order rate constants k2 and the activation parameters for the reaction of 2‐thiophenesulfonyl chloride with aniline together with solution enthalpies of the reactants have been measured in methanol, ethanol, 2‐propanol, acetonitrile and acetone. The reaction rates are slower in dipolar aprotic solvents than in protic ones due to a remarkable activation negative entropy. The rate constants k2 are correlated with empirical solvent polarity parameters. The data seem in accord with a SAN reaction mechanism.
The synthesis and some chemical and spectroscopic properties of imidazo [1,2‐a] pyrazine
Authors: Depompei Michael F. , Paudler William W.
Published: April 2009

The parent imidazo [1,2‐a] pyrazine was prepared and shown to undergo electrophilic bromination at C‐3, and base‐catalyzed H→D exchange at C‐3 and C‐5. The perchloro derivative of this ring system was prepared and it was established that nucleophilic substitution by methoxide ion occurs at C‐5 and C‐8. Pmr spectral data for all compounds are presented.
Studies on isoindoline derivatives and related compounds. I Synthesis and reduction of 1,3‐dicarboethoxymethyleneisoindoline
Authors: Kurihara Takushi , Fukunaga Keizo , Sakaguchi Toshiko , Hirano Hiroshi
Published: April 2009

The reaction of iminoether III with benzyl cyanoacetate gave ethyl 1‐(α‐cyanocarbobenzyl‐oxymethylene)isoindoline‐3‐acetate (V) in a 26% yield. Decarboxylation of ethyl 1‐(α‐cyanocarboxymethylene)isoindoline‐3‐acetate (VI), obtained by hydrogenolysis of V, gave a mixture of 1‐carboethoxymethyleneisoindoline‐3‐acetonitrile (VII) as major component and 1‐carboethoxymethylene‐3‐cyanomethyleneisoindoline (VIII) as minor component, which were reconvertible into each other. On the other hand, decarboxylation of VI was successfully carried out to give VII as a single product under a nitrogen atmosphere. Ethanolysis and autoxidation of VII gave crystalline diethyl 1,3‐dicarboethoxymethyleneisoindoline (XIII). Catalytic hydrogenation of of XIII over platinum oxide gave diethyl isoindoline‐cis‐1,3‐diacetate (XIV) in a yield of 92%. The uv spectra of these 1,3‐disubstituted isoindoline derivatives are summarized in Table I.
Chiral 1,4‐benzodiazepines. IX. Attempts at a preparation of 7‐chloro‐5‐phenyl‐3(S)methyl‐1,4‐benzodiazepin‐2‐one through C(5)C(5a) bond formation
Authors: Šunjić V. , Kajfež F. , Blažević N. , Oklobdžija M. , Mildner P.
Published: April 2009

During attempts at preparation of 7‐chloro‐5‐phenyl‐3(S)methyl‐1,4‐benzodiazepin‐2‐one (9) by cyclisation of N'‐α‐chlorobenzylidene‐(S)alanyl‐p‐chloroaniline (7) and the related o,p‐dichloroaniline derivative (8), it was observed that the intermediate products, both N'‐benzylidene‐(S)alanyl‐p‐chloroaniline (5), as well as the related o,p‐dichloroaniline derivative (6), undergo cyclisation to N‐(p‐chlorophenyl)‐2‐phenyl‐4(S)methylimidazolidin‐5‐one (17), and N‐(o,p‐dichlorophenyl)imidazolidin‐5‐one (18), respectively. Isolation and properties of the side products, N'‐benzylated‐(S)alanyl‐p‐chloro‐, and o,p‐dichloroanilines (15 and 16), as well as of N'‐benzoylated‐(S)alanyl‐p‐chloroanilines (19 and 20) are described.
Alkylation par des dérivés d'indole. N‐Ethylation de pipéridines par le méthyl‐1 ethoxy‐2 indole carboxylate‐3 d'éthyle
Authors: Deberly A. , Abenhaim D. , Bourdais J.
Published: April 2009

Le méthyl‐1 éthoxy‐2 indole carboxylate‐3 d'éthyle se compurte comme un agent alcoylant vis à vis de nucléophiles comme la piperidine ou la méthyl‐2 piperidine. Cette réaction est très sensible aux effets stériques comme le montre les vitesses d'éthylation différentes de ces deux amines. On observe aussi – avec la pipéridine – une réaction d'amidification de la function ester mais le groupe éthoxy‐2 est attaqué préférentiellement.
The chemistry of 1,2,5‐thiadiazoles V. Synthesis of 3,4‐diamino‐1,2,5‐thiadiazole and [1,2,5] thiadiazolo[3,4‐b]pyrazines
Authors: Komin Andrew P. , Carmack Marvin
Published: April 2009

The o‐diamine, 3,4‐diamino‐1,2,5‐thiadiazole (2), was synthesized from 3,4‐dichloro‐1,2,5‐thiadiazole (3) hy three methods. Aqueous glyoxal cyclized 2 into [1,2,5]thiadiazolo[3,4–6]‐pyrazine (14). 3,4‐Dichloro‐1,2,5‐thiadiazole 1,1‐dioxide (18) reaeted with 2 to give 1,3‐dihydro‐bis[1,2,5]thiadiazolo[3,4‐b:3′,4′‐e]pyrazine 2,2‐dioxide (19). The reaction of 2 with selenium oxyehloride led to [1,2,5]selenadiazolo[3,4‐c] [1,2,5]thiadiazole (12). Ring closure of 2,3‐diaminoquinoxaline (4) with thionyl chloride or selenium oxychloride gave [1,2,5]thiadiazolo‐[3,4‐b]quinoxaline (21) and [1,2,5]selenadiazolo[3,4‐b]quinoxaline (22), respectively. Sulfurous acid reduced 21 to the 4,9‐dihydro derivative 23, which was reoxidized to 21 with chloranil. Aqueous hase hydrolyzed 21 to 4 via the hydrated intermediate 24. Aqueous glyoxal cyclized 4 to the covalent hydrate of pyrazino[2,3‐b]quinoxaline (26), 27, which was dehydrated to 26. Compound 26 underwent rapid addition of two alcohols in a process analogous to covalent hydration.
Studies on the syntheses of heterocyclic compounds. Part DCXLIV . Catalytic reduction of homoproaporphine related compounds
Authors: Kametani Tetsuji , Fukumoto Keiichiro , Satoh Fumio , Kigasawa Kazuo , Sugi Hideo
Published: April 2009

Hydrogenation of the homoproaporphine (IV) over platinum oxide gave a mixture of the cyclohexanols VIIa and VIIb. In contrast, reduction of IV on palladium provided the cyclo‐hexanone VI, which was also obtained from VIIb by oxidation. Treatment of the cyclohexanols VIIa and VIIb under hydrogen on platinum oxide afforded the same mixture of VIIa and VIIb.
A propos de la structure de pyrimidines obtenues par condensation de l'acide cyanacétique et de monoalkylurées
Authors: Lefebvre Alain , Bernier Jean‐Luc , Lespagnol Ch.
Published: April 2009

Il est classiquement admis que la condensation de l'acide cyanacétique et d'une monoalkylurée conduit à la formation d'une alkyl‐1 dioxo‐2,4 amino‐6 tétrahydro‐1,2,3,4 pyrimidine. Cependant, la vérification n'en a été réalisée que dans deux cas et par une synthèse longue et délicate. L'étude de la N′ cyanacétyl N isobutylurée, intermédiaire de la préparation d'une telle pyrimidine, apporte une confirmation supplémentaire s'appuyant sur une étude en RMN. La méthode utilisée est généralisable.
Synthesis of 3‐Chloro‐2‐hydroxyimipramine and 3‐chloro‐8‐hydroxyimipramine, Hypothetical metabolites of clomipramin
Authors: Zirnis Aija , Piszkiewicz Frederick F. , Martian Albert A.
Published: April 2009

Fremy salt oxidation of 3‐chloroiminodibenzyl yields a mixture of two isomeric iminequinones, which can be separated and reduced to aminophenols and the phenolic group protected with addition of dihydropyran. Introduction of theN,N‐dimethylaminopropyl side chain and removal of the protective group provided the two chlorohydroxyimipramines, which can serve as standards for the identification of possible biotransformation products of the parent drug, clomipramine.
Syntheses de naphthyridines‐1,7
Authors: Decormeille M. M. A. , Guignant F. , Queguiner G. , Pastour P.
Published: April 2009

La condensation de l'amino‐3 isonicotinaldéhyde avec des composés à méthyle ou méthylene activé par un groupement carbonyle conduit à des alkyl naphthyridines‐1,7 et à des systèmes polyhétérocycliques à noyaux assemblés.