bluuebunny/crossref_metadata_2025_split huggingface dataset:
The presence of the HLA class. II allele DPB1*0501 in ethnic Thais correlates with an enhanced vaccine‐induced antibody response to a malaria sporozoite antigen
Authors: Stephens Henry A. F. , Brown Arthur E. , Chandanayingyong Dasnayanee , Webster H. Kyle , Sirikong Monchan , Longta Panpimon , Vangseratthana Rapeepun , Gordon Daniel M. , Lekmak Somboon , Rungruang Ekaraj 
Published: March 2007

AbstractIn this study, we examined the correlation between the frequency of allelic variants of the class II human leukocyte antigen (HLA) DR, DQ and DP gene loci and the quantitative humoral immune response observed in 71 Thai volunteers, subsequent to vaccination with a conjugated subunit vaccine. This vaccine was designed to induce antibodies directed against the immunodominant repeat region of the Plasmodium falciparum circumsporozoite (CS) protein. The presence of the DPB1*0501, a relatively common allele in Asian populations, was found to be associated with high vaccine‐induced CS repeat‐specific antibody responses in the volunteers. Given the increasing focus on the use of subunit vaccines in the control of infectious diseases, consideration of the influence of class II allele frequencies in ethnically diverse recipient populations may be important.
Elucidation of the protein kinase C‐dependent apoptosis pathway in distinct subsets of T lymphocytes in MRL‐lpr/lpr mice
Authors: Ohkusu Kozo , Isobe Ken‐Ichi , Hidaka Hiroyoshi , Nakashima Izumi 
Published: March 2007

AbstractMRL‐lpr mice are severely impaired in the Fas pathway of apoptosis induction. We here evaluate another pathway of apoptosis induction in MRL‐lpr mice which is protein kinase C (PKC) dependent. Despite the defect of the Fas pathway, apoptosis developed during culture in vitro in splenic T lymphocytes from MRL‐lpr mice more extensively than in T lymphocytes from MRL‐+/+ mice. Apoptosis induction in the former cells was then found to be greatly promoted by PKC inhibitor H‐7, and partially prevented by PKC activator phorbol 12‐myristate 13‐acetate (PMA). High sensitivity to H‐7, but not to PKA inhibitor HA 1004, of these cells for apoptosis induction was confirmed by detailed time course and dose‐dependency experiments of the drug effect. Population analysis showed that both CD4+ T lymphocytes and CD8+ T lymphocytes from MRL‐lpr mice were highly sensitive to H‐7, whereas CD8+ T lymphocytes, but not CD4+ T lymphocytes, from MRL‐+/+ mice were susceptible to the reagent. Interestingly, B220+Thy‐1+CD4−CD8− T lymphocytes from MRL‐lpr mice were most sensitive to H‐7 for apoptosis induction. Correspondingly, the membrane‐translocated activated PKC‐α level in splenic T lymphocytes from MRL‐lpr was more extensively up‐regulated by PMA than in splenic T lymphocytes from MRL‐+/+. These results suggest that some signal consistently activates PKC in MRL‐lpr T lymphocytes, and this event is needed for survival of these cells. On the other hand, CD4+CD8+ thymocytes were deleted by apoptosis in culture with PMA, whether these thymocytes were from MRL‐lpr mice or MRL‐+/+ mice. This finding suggested that the apoptosis induction pathway linked to PKC activation is intact in CD4+ CD8+ thymocytes from the Fas‐defective MRL‐lpr mice. We conclude from these results that the PKC‐dependent signal pathways for either cell death or cell activation are intact or even accelerated in lpr mice, which could both compensate for the loss of the Fas pathway and promote the generation of autoreactive T lymphocytes.
Tumor necrosis factor‐α induction of major histocompatibility complex class. II antigen expression is inhibited by interferon‐γ in a monocytic cell line
Authors: Willheim Martin , Silacci Paolo , Gessl Alois , Spittler Andreas , Szépfalusi Zsolt , Samorapoompichit Puchit , Agis Hermine , Mayr Wolfgang R. , Scheiner Otto , Förster Othmar , Mach Bernard , Boltz‐Nitulescu Georg 
Published: March 2007

AbstractRegulation of major histocompatibility complex (MHC) class II antigen expression by cytokines has been suggested to play a major role in the initiation and propagation of immune and autoimmune processes. The analysis of class II gene regulation benefits greatly from the existence of mutants with defects in regulatory factors. We report the establishment of a subclone of the human monocytic cell line U937, termed C119/9, with unusual cytokine regulation of MHC class II expression. In contrast to the parental U937 cell line, only tumor necrosis factor (TNF)‐α, and not interferon (IFN)‐γ induces the expression of MHC class II antigens on C119/9 cells, and paradoxically, this induction was inhibited almost completely by IFN‐γ. The HLA‐DR induction is controlled at the transcriptional level by the first 150 bp of the class II promoter which contains all the class II consensus elements. Both HLA‐DR and ‐DQ mRNA are induced by TNF‐α treatment, and both are diminished upon co‐treatment with TNF‐α and IFN‐γ. This antagonism between TNF‐α and IFN‐γ seem to be restricted to MHC class II genes. This subline of U937 cells may be useful in further studies of MHC class II regulation.
CD40‐CD40 ligand interactions stimulate B cell antigen processing
Authors: Faassen Anne E. , Dalke David P. , Berton Michael T. , Warren Wendy D. , Pierce Susan K. 
Published: March 2007

AbstractThe interactions between B cell CD40 and T cell CD40 ligand (CD40L) have been shown recently to play an important role in T cell‐dependent activation of B cells. Here, we show that the ligation of CD40 stimulates the processing of antigen by B cells. The activation of an antigen‐specific T cell hybrid by B cells co‐cultured with insect cells expressing recombinant CD40L or with a CD40‐specific monoclonal antibody requires less antigen and fewer B cells compared to control cells. The augmentation was observed both for processing initiated by antigen binding to and cross‐linking the surface immunoglobulin, and processing of antigen taken up by fluid‐phase pinocytosis. CD40 appears to affect a step in the intracellular processing of antigen, as CD40 has no effect on the presentation of an antigenic peptide which does not require processing. In addition, the CD40‐induced augmentation of processing is not attributable to the effect of CD40 ligation on the cell surface expression of B7, LFA‐1 or CD23. CD40 ligation does not affect the biosynthesis of the class II Ek molecules, and although ligation of CD40 induces B cell proliferation, the augmentation of processing does not require proliferation. The ability of CD40 to stimulate B cell antigen processing has the potential to influence significantly the outcome of antigen‐dependent T cell‐B cell interactions.
T helper cell‐independent neutralizing B cell response against vesicular stomatitis virus: Role of antigen patterns in B cell induction?
Authors: Bachmann Martin F. , Hengartner Hans , Zinkernagel Rolf M. 
Published: March 2007

AbstractThe neutralizing antibody response against vesicular stomatitis virus (VSV) was studied to analyze conditions necessary for induction of mature B cells. The glycoprotein of VSV (VSV‐G) is expressed as repetitive epitopes that are in a rigid densely packed paracristalline form in the virus envelope; in contrast, VSV‐G is present in a mobile randomly ordered form on infected cells and in micelles. We found that the rigid, paracristalline form of VSV‐G spaced about 5–10 mm on VSV virons induced potent primary and secondary neutralizing B cell responses which were independent of T helper cells, whereas the more randomly distributed, mobile forms of VSV‐G induced primary and secondary B cell responses that were more tightly controlled by T helper cells. These data suggest that (i) cross‐linking is a critical signal for B cell activation and antibody production, and that this signal alone does not necessarily anergize or delete mature B cells, (ii) the more regularly and rigidly ordered in a distance of 5–10 nm repetitive identical antigenic determinants are, the less are primary and secondary B cell responses controlled by T cells. We therefore propose that B cells take antigen organization as a marker for foreigness.
Default development of cloned human naive CD4 T cells into interleukin‐4‐ and interleukin‐5‐producing effector cells
Authors: Yang Liang‐Peng , Byun Dae‐Gyoo , Demeure Christian E. , Vezzio Nadia , Delespesse Guy 
Published: March 2007

AbstractIt was recently demonstrated that naive human and mouse CD4 T cells release low but sufficient levels of interleukin (IL)‐4 at priming to support their development into IL‐4 producers. To determine whether this IL‐4 is produced by a minor subset of cells, freshly isolated human naive CD4 T cells were directly cloned by limiting dilution in the absence of exogenous IL‐4. More than 95% of neonatal and 60% of adult naive T cells seeded in single‐cell cultures could be expanded upon stimulation with anti‐CD3 mAb immobilized on CD32‐B7.1 L cell transfectants in the presence of IL‐2. All 171 clones derived from four neonates and two adults produced IL‐4 and IL‐5 at generally high levels. Like the allergen‐specific human Th2 clones described in the literature, these T cell clones produced little or no interferon γ upon stimulation via their T cell receptor/CD3 complex, whereas they released high levels of this cytokine when activated with phorbol 12‐myristate 13‐acetate + ionomycin. Cells cloned and expanded in the presence of anti‐IL4 + anti‐IL‐4R mAb produced much lower levels of IL‐4 and IL‐5. It is concluded that almost every single naive human CD4 T cell primed and expanded in the absence of exogenous IL‐4 releases sufficient autocrine IL‐4 to support its clonal expansion into high IL‐4/IL‐5 producers.
IL‐18 time‐dependently modulates Th1/Th2 cytokine production by ligand‐activated NKT cells
Authors: Uchida Takefumi , Kinoshita Manabu , Fukasawa Masashi , Habu Yoshiko , Shinomiya Nariyoshi , Seki Shuhji 
Published: March 2007

AbstractWhile IL‐18 synergizes with IL‐12 to induce a Th1 immune response, it also promotes a Th2 response. Here we investigate the modulatory role of IL‐18 on the Th1/Th2 cytokine response. The injection of α‐galactosylceramide (α‐GalCer), a ligand for NKT cells, elevated mouse serum levels of both IFN‐γ and IL‐4. When the mice were treated 2 h before α‐GalCer challenge with IL‐18, IFN‐γ production but not IL‐4 production was remarkably up‐regulated. In contrast, pretreatment with IL‐18 6 h before the challenge enhanced IL‐4 production. However, this IL‐18‐enhanced IL‐4 production was not elicited in mice injected with anti‐CD3 Ab. Liver mononuclear cells (MNC) produced a similar cytokine production pattern when MNC from mice treated with IL‐18 either 2 h or 6 h before challenge were stimulated with α‐GalCer in vitro. Expression of SOCS1 and SOCS3 was notably up‐regulated in the liver MNC from mice pretreated 6 h before with IL‐18; in particular, SOCS3 expression was confined to the liver NKT cells. Inhibition of SOCS3 by RNA interference up‐regulated the phosphorylation of STAT3 and suppressed in vitro IL‐4 production by IL‐18‐primed liver MNC stimulated with α‐GalCer, but it did not affect IFN‐γ production. These results suggest that IL‐18 time‐dependently modulates Th1/Th2 cytokine production in ligand‐activated NKT cells by regulating/inducing SOCS3 expression.
Arginase activity mediates reversible T cell hyporesponsiveness in human pregnancy
Authors: Kropf Pascale , Baud David , Marshall Sara E. , Munder Markus , Mosley Angelina , Fuentes José M. , Bangham Charles R. M. , Taylor Graham P. , Herath Shanti , Choi Beak‐San , Soler Germán , Teoh Tg , Modolell Manuel , Müller Ingrid 
Published: March 2007

AbstractComplex regulation of T cell functions during pregnancy is required to ensure materno‐fetal tolerance. Here we reveal a novel pathway for the temporary suppression of maternal T cell responses in uncomplicated human pregnancies. Our results show that arginase activity is significantly increased in the peripheral blood of pregnant women and remarkably high arginase activities are expressed in term placentae. High enzymatic activity results in high turnover of its substrate L‐arginine and concomitant reduction of this amino acid in the microenvironment. Amino acid deprivation is emerging as a regulatory pathway of lymphocyte responses and we assessed the consequences of this enhanced arginase activity on T cell responses. Arginase‐mediated L‐arginine depletion induces down‐regulation of CD3ζ, the main signalling chain of the TCR, and functional T cell hyporesponsiveness. Importantly, this arginase‐mediated T cell suppression was reversible, as inhibition of arginase activity or addition of exogenous L‐arginine restored CD3ζ chain expression and T cell proliferation. Thus, L‐arginine metabolism constitutes a novel physiological mechanism contributing to the temporary suppression of the maternal immune response during human pregnancy.
Can Four‐Membered Heterophosphete Structures Exist? The Contribution of Phosphorus d Orbitals to Antiaromaticity
Authors: Mucsi Zoltán , Kötvélyesi Tamás , Viskolcz Béla , Csizmadia Imre G. , Novák Tibor , Keglevich György 
Published: February 2007

AbstractThe large instability of heterophosphete compounds, composed of a four‐membered unsaturated ring with a pentavalent phosphorus atom and a heteroatom, has been identified and characterised by first‐principle molecular orbital computations, at several levels of theory. It has been shown that strong electron‐withdrawing groups bound to the phosphorus atom are able to stabilize the system. The extent of antiaromaticity of these compounds is examined and quantified by a linear aromatic and antiaromatic scale.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Electroactive Nanostructured Membranes (ENM): Synthesis and Electrochemical Properties of Redox Mediator‐Modified Gold Nanoparticles Using a Dendrimer Layer‐by‐Layer Approach
Authors: Crespilho Frank N. , Ghica M. Emilia , Zucolotto Valtencir , Nart Francisco C. , Oliveira Osvaldo N. , Brett Christopher M. A. 
Published: February 2007

AbstractThe layer‐by‐layer (LbL) self‐assembly process has become an important tool in the fabrication of nanostructured devices for electrochemical applications, especially in those cases where control at the molecular level is required. In this paper we present a system based on electroactive nanostructured membranes (ENM) with ITO‐PVS/PAMAM‐Au LbL electrodes, in which a redox mediator (Me) is electrodeposited around the Au nanoparticles to form an ITO‐PVS/PAMAM‐Au@Me system. The redox mediators used were Co, Fe, Ni and Cu hexacyanoferrates. The 3‐bilayer ITO‐PVS/PAMAM‐Au@Me system was characterized electrochemically by cyclic voltammetry and electrochemical impedance spectroscopy. All hexacyanoferrate modified electrodes showed electrocatalytic activity towards hydrogen peroxide, thus demonstrating that this new approach can be used in biosensors and nanodevices, where a redox mediator is required.
Biosensor Based on Self‐Assembling Glucose Oxidase and Dendrimer‐Encapsulated Pt Nanoparticles on Carbon Nanotubes for Glucose Detection
Authors: Xu Lihuan , Zhu Yihua , Tang Longhua , Yang Xiaoling , Li Chunzhong 
Published: February 2007

AbstractA novel amperometric glucose biosensor based on layer‐by‐layer (LbL) electrostatic adsorption of glucose oxidase (GOx) and dendrimer‐encapsulated Pt nanoparticles (Pt‐DENs) on multiwalled carbon nanotubes (CNTs) was described. Anionic GOx was immobilized on the negatively charged CNTs surface by alternatively assembling a cationic Pt‐DENs layer and an anionic GOx layer. Transmission electron microscopy images and ζ‐potentials proved the formation of layer‐by‐layer nanostructures on carboxyl‐functionalized CNTs. LbL technique provided a favorable microenvironment to keep the bioactivity of GOx and prevent enzyme molecule leakage. The excellent electrocatalytic activity of CNTs and Pt‐DENs toward H2O2 and special three‐dimensional structure of the enzyme electrode resulted in good characteristics such as a low detection limit of 2.5 μM, a wide linear range of 5 μM–0.65 mM, a short response time (within 5 s), and high sensitivity (30.64 μA mM−1 cm−2) and stability (80% remains after 30 days).
Prediction of elastic displacement response spectra in Europe and the Middle East
Authors: Akkar Sinan , Bommer Julian J. 
Published: February 2007

AbstractEmpirical equations are presented for the prediction of displacement response ordinates for damping ratios of 2, 5, 10, 20 and 30% of critical and for response periods up to 4s, using 532 accelerograms from the strong‐motion databank from Europe and the Middle East. The records were all re‐processed and only employed for regressions at periods within the usable range, defined as a fraction of the filter cut‐off and depending on the instrument type (digital or analogue), earthquake magnitude and site class. The equations can be applied to predict the geometric mean displacement and pseudo‐acceleration spectra for earthquakes with moment magnitudes (M) between 5 and 7.6, and for distances up to 100km. The equations also include style‐of‐faulting and site class as explanatory variables. The predictions obtained from these new equations suggest that earlier European equations for spectral displacements underestimate the ordinates at longer periods as a result of severe filtering and the use of the spectral ordinates at periods too close to the filter cut‐off. The results also confirm that the period defining the start of the constant displacement plateau in the Eurocode 8 (EC8) spectrum is excessively short at 2s. The results not only show that the scaling factor defined in EC8 for estimating the spectral ordinates at damping ratios different from 5% of critical are a good general approximation, but also that this scaling varies with magnitude and distance (reflecting the influence of duration) and also displays a mild dependence on response period. Copyright © 2007 John Wiley & Sons, Ltd.
Increasing evaluation use among policymakers through performance measurement
Authors: Mohan Rakesh , Tikoo Minakshi , Capela Stanley , Bernstein David J. 
Published: February 2007

AbstractPerformance measurement can benefit evaluation by clarifying policy intent, program goals, and performance expectations and by facilitating systematic data collection. Because policymakers tend to support performance measurement for accountability purposes, linking performance measurement to evaluation has the potential of increasing evaluation use among policymakers.
B‐scan ultrasonography during orbital surgery
Authors: Purnell E. W. , Cappaert W. E. , Sokollu A. 
Published: February 2007

AbstractB‐scan ultrasonography is being performed with a newly developed hand‐held scanner during retrobulbar tumor surgery. We believe that it is a valuable aid in the localization and the removal of these tumors. The instrument may be directly inserted into the surgical wound, permitting otherwise unobtainable views of the lesion and of the adjacent structures.
Echocardiographic diagnosis of a left atrial myxoma found attached to the free left atrial wall
Authors: Johnson Michael L. , Sieker Herbert O. , Behar Victor S. , Whalen Robert E. 
Published: February 2007

AbstractThe echocardiographic diagnosis of a left atrial myxoma is described. This was later confirmed by cardiac catheterization and the tumor removed at operation. The myxoma was found to arise from the free left atrial wall and no such case diagnosed by echocardiography has previously been reported. The possibility of false negative and false positive echocardiographic findings is discussed. Echocardiography is an accurate, atraumatic, and rapid diagnostic technique which can be used as a simple screening procedure in cardiac evaluations.
Echocardiographic M‐scan technique in the diagnosis of pericardial effusion
Authors: Abbasi A. S. , Ellis Nancy , Flynn John J. 
Published: February 2007

AbstractM‐scanning was found useful in eight patients in whom the diagnosis of pericardial effusion was negative or equivocal with conventional echocardiography. With the patient in the semi‐recumbent position, the records were obtained while the ultrasound beam was sector scanned base toward the cardiac apex. With this technique, a separation of the posterior pericardium epicardium by a divergent echo‐free space was noted when pericardial effusion was present. The divergent nature of the echo‐free space was due to accumulation of pericardial fluid toward the cardiac apex. The shift of pericardial fluid toward the cardiac apex was further demonstrated by elevation of the patient supine to the semi‐recumbent position. The latter position enhances the sensitivity of M‐scanning in the detection of pericardial effusion.
Diagnostic ultrasound in radiation treatment planning
Authors: Brascho Donn J. 
Published: February 2007

AbstractDiagnostic ultrasound provides the radiation therapist a very practical method of acquiring anatomical information for developing optimized radiation therapy plans. With ultrasound it is possible to record simultaneously the contour of the patient and the location and depth of tumors and normal structures. This information can easily be incorporated into current methods of computerized treatment planning. Ultrasound examination also assists in the accurate placement of treatment ports on the body surface, and allows adjustment of field size as tumors respond to treatment. It is predicted that diagnostic ultrasound examination will become a standard method of obtaining anatomical information for radiation therapy planning in all modern radiation treatment facilities.
Errors in performance and interpretation of echocardiograms
Authors: Kerber Richard E. 
Published: February 2007

AbstractDiagnostic ultrasound affords important information about cardiac structure and motion. However, because of the unique manner in which data are acquired and displayed during echocardiography, diagnostic errors and misinterpretations are not uncommon. This paper discusses the characteristic echocardiographic patterns of a variety of important cardiac conditions: mitral stenosis and mitral regurgitation, aortic regrugitation, idio‐pathic hypertrophic subaortic stenosis, left atrial myxoma, pericardial effusion and right ventricular volume overload. Potential pitfalls in achieving the correct diagnosis in each of these conditions are emphasized, with illustrative examples of correct and incorrect interpretations. Good technique and appropriate clinical correlation are important in the performance of accurate ultrasound cardiac examinations.
The sign of the vena cava: Echotomographic illustration of right cardiac insufficiency
Authors: Weill F. , Maurat P. 
Published: February 2007

AbstractIn patients with hepatomegaly, evaluation of the vena cava was diagnostically valuable in differentiating between cardiac failure as a cause of the hepatomegaly and other causes. Studies were done using equipment with a mechanically moving probe to provide constant visualization of the vena cava. In normal patients, the vena cava is animated by a double motion from transmitted systolic pulsations and from the respiratory cycle. In normal patients, the vena cava collapses during expiration and in patients with right heart failure, the respiratory kinetics disappear and the inferior vena cava remains turgescent throughout the respiratory cycle.
Echocardiographic determinations of dimensions of normal newborns at 5,280 feet elevation
Authors: Lortscher Randall H. , Williams Clifford , Wolfe Robert R. , Nora James J. , Spangler Richard D. 
Published: February 2007

AbstractTwenty healthy term newborn infants born at St. Anthony Hospital in Denver, Colorado were examined by echocardiography during the first 72 hours of life. All infants were without cardiac or pulmonary disease and were appropriate for gestational age within the classification of Battalion and Lubchenco. Measurements of intracardiac dimensions, including right ventricular cavity, left ventricular cavity, left atrium and aortic root, as well as thickness of the intraventricular septum and posterior wall of the left ventricle, were determined by three independent observers. The data correlated with other studies performed at centers located at lower elevations.