bluuebunny/crossref_metadata_2025 huggingface dataset:
Health- and Disease-Related Biomarkers in Aging Research
Authors: Thompson Hilaire J. , Voss Joachim G.
Published: June 2009

This article focuses on a synthesis of knowledge about healthy aging research in human beings and then synthesized nurse-led research in gerontology and geriatrics that use biomarkers. Healthy aging research has attracted considerable attention in the biomedical and basic sciences within the context of four major areas: (a) genetic variations as an expression of successful or unsuccessful aging; (b) caloric restriction as an intervention to slow the progression of aging; (c) immunological aging; (d) neurobiology of the aging brain. A systematic review of the literature was performed to identify nurse-led geriatric-related biomarker research. Nurse researchers who have chosen to integrate biomarkers as part of their research studies have been working in six focal areas, which are reviewed: health promotion within risk populations, cancer, vascular disease, Alzheimer's disease, caregiving, and complementary therapies. The article provides a discussion of contributions to date, identifying existing gaps and future research opportunities.
Use of Agency Staff in Nursing Homes
Authors: Castle Nicholas G.
Published: June 2009

This article describes the extent and degree of use of agency staff by nursing homes and examines the relationship between agency staffing levels and quality of care in a large sample of nursing homes (
N
= 3,876). The quality indicators came from the Nursing Home Compare Web site. It was found that many nursing homes used agency staff (approximately 60% used at least some), and a strong association between better quality and lower agency use existed for both nurse aides and RNs. The influence on quality for the highest levels of agency use, compared with no agency use, was clinically significant. On the basis of these findings, facilities considering using high levels of agency staff should do so carefully.
Therapeutic Conversation to Improve Mood in Nursing Home Residents with Alzheimer's Disease
Authors: Tappen Ruth M. , Williams Christine L.
Published: June 2009

Few studies have tested strategies to address the mental health needs of individuals with Alzheimer's disease (AD). To test a newly developed, empirically based modified counseling approach, 30 nursing home residents with AD were randomly assigned to a modified counseling (Therapeutic Conversation) treatment group or usual care control group. Mini-Mental State Examination mean scores were 10.60 (
SD
= 6.99) for the treatment group and 12.26 (
SD
= 7.43) for the control group. Individual treatment was provided three times per week for 16 weeks. On the posttest, treatment group participants evidenced significantly less negative mood than the control group on the Montgomery-Asberg Depression Rating Scale and the Sadness and Apathy subscales of the Alzheimer's Disease and Related Disorders Mood Scale. The differences approached significance on the Dementia Mood Assessment Scale. Results suggest that a therapeutic counseling approach can be effective in treating the dysphoria commonly found in individuals with AD.
Designing Multimodal User-Interfaces for Effective E-Learning in the School Primary Stages Applied on Real Fractions
Authors: Odeh Salaheddin , Qaraeen Omar
Published: June 2009

This contribution focuses on the development and design of e-learning tools for school students in primary stages through dealing and considering the math of real fractions, which presents an example of learning material difficult to understand by many school students and a real challenge for e-learning designers and multimedia authoring. Firstly, we will highlight several problems facing school students and teachers caused by the traditional learning approach. Then, we are going to discuss some aspects related to e-learning, the major theoretical issues of educational psychology and e-learning with various modalities related to our work, and the classification of the interactive multimedia methodologies adopted in this work. Furthermore, the software-ergonomic and â??architectural features of the developed e-learning tool will be introduced. Finally, the paper will conclude with a brief summary of a usability testing carried out to compare the developed e-learning user-interface with the traditional learning approach.
The Influence of Cache Organization on E-learning Environments
Authors: Al-Nsour Ayman
Published: June 2009

In this study, the performance of an e-learning environment is analyzed and evaluated in terms of average network traffic and upload/download rates under various cache memory organizations. In particular, we study the influence of three cache organizations, namely fully associative, direct, and set associative caches.

As a result of this work, we recommend the set associative cache memory organization with the LFU replacement policy, as this led to optimal performance in e-learning environments with the highest hit ratio and upload/download rates.
Strategies for Teaching a Novel Approach to Handling Uncertainty Scientifically via Internet
Authors: Zhai Xiaomin , Von Collani Elart
Published: June 2009

More than 300 years ago Jakob Bernoulli made an attempt to initiate and to develop the Science of Prediction, which is in Latin Ars conjectandi and in Greek Stochastike. The aim of Bernoulliâ??s stochastics is not to discover â??truth
A Quantitative Study on Attitudes of Web-Based Mathematic Competition in Different Learning Stages students in Taiwan
Authors: Tso Tai Cheng , Chiang Feng Kuang , Lu Hsin Chang , Sun Chung Shan
Published: June 2009

The study mainly investigates the studentsâ?? attitudes toward mathematic learning and web-based mathematic competition in different learning stages in Taiwan. This study was to conduct an online survey, which is driven by three issues: (1) What are the differences in mathematical learning attitudes with the web-based mathematics competition in the different learning stages (2) Is there any significant difference between studentsâ?? mathematical learning attitudes to take part in the web-based mathematics competition in the different learning stages? (3) Is there any correlation between studentsâ?? mathematical learning attitudes, the participatorsâ?? motivation and the attitudes of studentsâ?? took part in the web-based mathematics competition? The research targets of this study are 277 students, including 207(74.7%) boys and 70(25.3%) girls. The collected data of this study was analyzed by descriptive statistics, one-way ANOVA, Scheffeâ?? method and Pearsonâ??s product-moment correlation. Following are the results of the study: There is significant motivational difference between elementary school and junior high school students to participate the web-based mathematic competition and there are middle relationships between studentsâ?? mathematical learning attitudes, the participatorsâ?? motivation and the attitudes of studentsâ?? took part in the web-based mathematics competition.
Studying the Impact of Web-Based Learning (Weblog) With a Problem Solving Approach on Student's Reflective Thinking
Authors: Namvar Yousef , Naderi Ezatolah , Shariatmadari Ali , Seifnaraghi Maryam
Published: June 2009

The aim of this research is studying the effect of web- based learning(weblog) by problem solving approach on English Literature student's reflective thinking, who study in Islamic Azad University of Ardebil. Required data for this study was gathered through reflective thinking questionnaire -designed by Camber et al on the basis of Maziro's Theory- in pretest and posttest form, for the two experimental and control groups each consisting of 15 students. Analyzing the gained data showed that there was significant difference between the two experimental and control groups regarding the level of thinking about the three categories of understanding, reflection, and critical reflection, and it was significant in T-test at level 0.05 and this shows that the weblog based learning affects on the development of student's reflective thinking.
E-learning Competencies for Teachers in Secondary and Higher Education
Authors: Jans Sebastiaan , Awouters Valère
Published: June 2009

Teaching and learning with ICT requires specific competencies for teachers and lectures. Too much attention was given to the technological aspects. Teachers learned to work with hard- and software. A typical example is the European Computer Driving License (ECDL). A lot of people attend courses on text processing, spreadsheets,â?¦ but using a Virtual Learning Environment like e.g. Blackboard or Moodle demands more didactical than technical skills. Especially e-learning and blended learning is too demanding to let teachers learn to use these tools only by experimenting. More and more is generally accepted that the e-learning competencies for teachers require a longer course. Which competences and how these can be realized is the main focus of this paper? Besides the theoretical background, two examples will be showed.
Schema Design and Normalization Algorithm for XML Databases Model
Authors: Abou El-Seoud Samir , El-Sofany Hosam
Published: June 2009

In this paper we study the problem of schema design and normalization in XML databases model. We show that, like relational databases, XML documents may contain redundant information, and this redundancy may cause update anomalies. Furthermore, such problems are caused by certain functional dependencies among paths in the document. Based on our research works, in which we presented the functional dependencies and normal forms of XML Schema, we present the decomposition algorithm for converting any XML Schema into normalized one, that satisfies X-BCNF.
Normalization and Personalization of Learning Situation: NPLS
Authors: Abik Mounia , Ajhoun Rachida
Published: June 2009

The personalization of learning is a major pedagogical challenge solicited by pedagogues and didacts. There are several projects about the production of personalizable learning situations such as Reload-LDE and Alfanet. These projects are interested in producing new standardized and personalizable learning situations. However, on the Web, an important number of learning situations exist. These situations are rich in information but don't consider all the characteristics of participants taking part in the learning, nor their technical environments. In this paper we suggest a help system that can transform an existing learning situation to another structure standardized and personalizable depending on the context of learning personalization that we have defined.
The Magic Cube of eAccounting – Instructional Design in Management Education
Authors: Pernsteiner Silvia Maria , Schaffhauser-Linzatti Michaela Maria , Michaski-Karl Regina
Published: June 2009

This paper exemplifies the curricular framework of instructional design in management education at universities. The Magic Cube of eAccounting meets the didactical challenges concerning heterogeneous levels of preknowledge within large-scale accounting classes up to 600â??mostly non-native speakingâ??undergraduate students. Following the Blended Learning approach, the presented pedagogical concept subsumes diverse subjects in the field of accounting and its inclusive adoption in continuative well as comprehensive courses. The applied methodology deals with these multi-dimensional impacts directed by a didactic rationale. The e-Learning architecture shows a universally applicable design and may be customized. The eAccounting project was developed at the Faculty of Business, Economics and Statistics at the University of Vienna and has been implemented in 2008.
Selective Reduction of Graft-versus-Host Disease-Mediating Human T Cells by Ex Vivo Treatment with Soluble Fas Ligand
Authors: Bohana-Kashtan Osnat , Morisot Sebastien , Hildreth Richard , Brayton Cory , Levitsky Hyam I. , Civin Curt I.
Published: June 2009

Previous work done in our laboratory, using mouse models, showed that soluble Fas ligand (sFasL) can efficiently delete donor anti-host T cells during their activation against irradiated host cells in MLCs. In the mouse models, this ex vivo sFasL treatment abrogated graft-vs-host disease (GVHD) while sparing donor T cells with antitumor reactivity. The present work was performed with human cells, to extend our work toward reduction of clinical GVHD. PBMC responders from a given individual (first party) were stimulated in vitro with irradiated PBMC stimulators from a second person (second party), in the presence of sFasL. In control MLCs without sFasL, alloreacting T cells began to up-regulate Fas (CD95) detectably and became sensitive to Fas-mediated apoptosis by as early as day 1–2. In MLCs containing sFasL, there were greatly reduced numbers of alloreacting CD3+CFSElo cells, activation Ag-expressing CD4hi and CD8hi cells, IFN-γ-producing CD4+ and CD8+ cells, and CD8+CD107a+ CTLs. Furthermore, mice transplanted with the ex vivo sFasL/MLR-treated cells had prolonged time to fatal GVHD in an in vivo xenogeneic GVHD model. Responder cells harvested from primary MLCs containing sFasL had reduced proliferation in response to second party cells, but proliferated in response to CMV Ags, PHA, and third party cells. In addition, sFasL/MLR-treated cell populations contained influenza-specific T cells, CD4+FOXP3+ T cells, and CD4+CD25+ T cells. These data indicate that this ex vivo sFasL/MLR depletion of alloreacting human donor anti-host T cells was efficient and selective.
Cutting Edge: Cardiac Myosin Activates Innate Immune Responses through TLRs
Authors: Zhang Ping , Cox Carol J. , Alvarez Kathy M. , Cunningham Madeleine W.
Published: June 2009

Autoimmune attack on the heart is linked to host immune responses against cardiac myosin, the most abundant protein in the heart. Although adaptive immunity is required for disease, little is known about innate immune mechanisms. In this study we report that human cardiac myosin (HCM) acted as an endogenous ligand to directly stimulate human TLRs 2 and 8 and to activate human monocytes to release proinflammatory cytokines. In addition, pathogenic epitopes of human cardiac myosin, the S2 fragment peptides S2-16 and S2-28, stimulated TLRs directly and activated human monocytes. Our data suggest that cardiac myosin and its pathogenic T cell epitopes may link innate and adaptive immunity in a novel mechanism that could promote chronic inflammation in the myocardium.
Evidence for the Specificity for Platelet HPA-1a Alloepitope and the Presenting HLA-DR52a of Diverse Antigen-Specific Helper T Cell Clones from Alloimmunized Mothers
Authors: Rayment Rachel , Kooij Taco W. , Zhang Wei , Siebold Christian , Murphy Mike F. , Allen Dave , Willcox Nick , Roberts David J.
Published: June 2009

Maternal alloantibodies against the human platelet Ag (HPA)-1a allotype of the platelet β3 integrin GpIIb/IIIa can cause severe fetal or neonatal hemorrhage. Almost all anti-HPA-1a-immune mothers are homozygous for HPA-1b and carry HLA-DR52a (DRB3*0101). The single Pro33 →Leu substitution (HPA-1b→HPA-1a) was previously predicted to create a binding motif for HLA-DR52a that can lead to alloimmunization. We have isolated six CD4+ T cell clones from three such mothers, which all respond to intact HPA-1a+, but not HPA-1b+, platelets. We used them to define the “core” and “anchor” residues of this natural T cell epitope. Molecular modeling based on a recently published crystal structure can explain the preferential presentation of the Leu33 (but not Pro33 variant) by HLA-DR52a rather than the linked HLA-DR3 or the allelic DR52b. The modeling also predicts efficient anchoring at position 33 by several alternative hydrophobic α-amino acids; indeed, a recently identified variant with Val33 is presented well to two clones, and is therefore potentially alloimmunogenic. Finally, these HPA-1a-specific T cell clones use a variety of T cell receptors, but all have a “Th1” (IFN-γ-producing) profile and are suitable for testing selective immunotherapies that might be applicable in vivo.
TGF-β Promotes Th17 Cell Development through Inhibition of SOCS3
Authors: Qin Hongwei , Wang Lanfang , Feng Ting , Elson Charles O. , Niyongere Sandrine A. , Lee Sun Jung , Reynolds Stephanie L. , Weaver Casey T. , Roarty Kevin , Serra Rosa , Benveniste Etty N. , Cong Yingzi
Published: June 2009

TGF-β, together with IL-6 and IL-21, promotes Th17 cell development. IL-6 and IL-21 induce activation of STAT3, which is crucial for Th17 cell differentiation, as well as the expression of suppressor of cytokine signaling (SOCS)3, a major negative feedback regulator of STAT3-activating cytokines that negatively regulates Th17 cells. However, it is still largely unclear how TGF-β regulates Th17 cell development and which TGF-β signaling pathway is involved in Th17 cell development. In this report, we demonstrate that TGF-β inhibits IL-6- and IL-21-induced SOCS3 expression, thus enhancing as well as prolonging STAT3 activation in naive CD4+CD25− T cells. TGF-β inhibits IL-6-induced SOCS3 promoter activity in T cells. Also, SOCS3 small interfering RNA knockdown partially compensates for the action of TGF-β on Th17 cell development. In mice with a dominant-negative form of TGF-β receptor II and impaired TGF-β signaling, IL-6-induced CD4+ T cell expression of SOCS3 is higher whereas STAT3 activation is lower compared with wild-type B6 CD4+ T cells. The addition of a TGF-β receptor I kinase inhibitor that blocks Smad-dependent TGF-β signaling greatly, but not completely, abrogates the effect of TGF-β on Th17 cell differentiation. Our data indicate that inhibition of SOCS3 and, thus, enhancement of STAT3 activation is at least one of the mechanisms of TGF-β promotion of Th17 cell development.
IFN-γ Promotes Generation of IL-10 Secreting CD4+ T Cells that Suppress Generation of CD8 Responses in an Antigen-Experienced Host
Authors: Liu Xiao Song , Leerberg Joanne , MacDonald Kelli , Leggatt Graham R. , Frazer Ian H.
Published: June 2009

Ags characterizing tumors or chronic viral infection are generally presented to the host immune system before specific immunotherapy is initiated, and consequent generation of regulatory CD4+ T cells can inhibit induction of desired effector CD8 T cell responses. IL-10 produced in response to ongoing Ag exposure inhibits generation of CD8 T cells in an Ag-experienced host. We now show that this IL-10 is produced by Ag experienced CD4+ glucocorticoid-induced tumor necrosis factor receptor+ T cells that also secrete IFN-γ upon antigenic stimulation, that IL-10 secretion by these cells is enhanced through IFN-γ signaling, and, unexpectedly, that IFN-γ signaling is required for inhibition of generation of Ag-specific CD8 T cell responses in an Ag-experienced host. Systemic inhibition of both IL-10 and IFN-γ at the time of immunization may therefore facilitate induction of effective immunotherapeutic responses against tumor specific and viral Ags.
A Novel Recombinant Fusion Protein Encoding a 20-Amino Acid Residue of the Third Extracellular (E3) Domain of CCR2 Neutralizes the Biological Activity of CCL2
Authors: Izhak Liat , Wildbaum Gizi , Zohar Yaniv , Anunu Rachel , Klapper Leah , Elkeles Adi , Seagal Jane , Yefenof Eitan , Ayalon-Soffer Michal , Karin Nathan
Published: June 2009

CCL2 is a key CC chemokine that has been implicated in a variety of inflammatory autoimmune diseases and in tumor progression and it is therefore an important target for therapeutic intervention in these diseases. Soluble receptor-based therapy is a known approach for neutralizing the in vivo functions of soluble mediators. Owing to the complexity of seven-transmembrane G protein-coupled receptors, efforts to generate neutralizing soluble chemokine receptors have so far failed. We developed a strategy that is based on the generation of short recombinant proteins encoding different segments of a G protein-coupled receptor, and tested the ability of each of them to bind and neutralize its target chemokine. We show that a fusion protein comprised of as few as 20 aa of the third extracellular (E3) domain of the CCL2 receptor, stabilized by the IgG H chain Fc domain (E3-IgG or BL-2030), selectively binds CCL2 and CCL16 and effectively neutralizes their biological activities. More importantly, E3-IgG (BL-2030) could effectively suppress the in vivo biological activity of CCL2, attenuating ongoing experimental autoimmune encephalomyelitis, as well as the development of human prostate tumor in SCID mice.
Tryptophan Deprivation Induces Inhibitory Receptors ILT3 and ILT4 on Dendritic Cells Favoring the Induction of Human CD4+CD25+ Foxp3+ T Regulatory Cells
Authors: Brenk Manuela , Scheler Marina , Koch Susanne , Neumann Jürgen , Takikawa Osamu , Häcker Georg , Bieber Thomas , von Bubnoff Dagmar
Published: June 2009

Tryptophan catabolism through IDO activity can cause nonresponsiveness and tolerance acting on T cells. Given the crucial importance of dendritic cells (DCs) in the initiation of a T cell response, surprisingly little is known about the impact of IDO activity and tryptophan deprivation on DCs themselves. In the present study, we show that human DCs differentiated under low-tryptophan conditions acquire strong tolerogenic capacity. This effect is associated with a markedly decreased Ag uptake as well as the down-regulation of costimulatory molecules (CD40, CD80). In contrast, the inhibitory receptors ILT3 and ILT4 are significantly increased. Functionally, tryptophan-deprived DCs show a reduced capacity to stimulate T cells, which can be restored by blockade of ILT3. Moreover, ILT3highILT4high DCs lead to the induction of CD4+CD25+ Foxp3+ T regulatory cells with suppressive activity from CD4+CD25− T cells. The generation of ILT3highILT4high DCs with tolerogenic properties by tryptophan deprivation is linked to a stress response pathway mediated by the GCN2 kinase. These results demonstrate that tryptophan degradation establishes a regulatory microenvironment for DCs, enabling these cells to induce T regulatory cells. The impact of IDO thus extends beyond local immune suppression to a systemic control of the immune response.
CD44high Memory CD8 T Cells Synergize with CpG DNA to Activate Dendritic Cell IL-12p70 Production
Authors: Wong Kok Loon , Tang Li Fang Melissa , Lew Fei Chuin , Wong Hok Sum Kenneth , Chua Yen Leong , MacAry Paul A. , Kemeny David M.
Published: June 2009

Protective memory CD8 T cell responses are generally associated with the rapid and efficient acquisition of CTL function. However, the ability of memory CD8 T cells to modulate immune responses through interactions with dendritic cells (DCs) during the early states of secondary Ag exposure is poorly understood. In this study, we show that murine Ag-specific CD44high CD8 T cells, representing CD8 T cells of the memory phenotype, potently activate DCs to produce high levels of IL-12p70 in conjunction with stimulation of DCs with the TLR 9 ligand, unmethylated CpG DNA. IL-12p70 production was produced predominantly by CD8α+ DCs and plasmacytoid DCs, and mediated by CD8 T cell-derived cytokines IFN-γ, GM-CSF, TNF-α, and surface CD40L. We also find that CD44high memory phenotype CD8 T cells were better DC IL-12p70 stimulators than CD44low naive phenotype CD8 T cells, and this was attributed to higher levels of IFN-γ and GM-CSF produced by CD44high memory phenotype CD8 T cells during their Ag specific interaction with DCs. Our study identifies CpG DNA as the most effective TLR ligand that cooperates with CD8 T cells for DC IL-12p70 production, and suggests that effectiveness of memory CD8 T cells could be attributed to their ability to rapidly and effectively induce protective Th1 immunity during early stages of pathogen reinfection.
Systemic Reduction of Functionally Suppressive CD4dimCD25highFoxp3+ Tregs in Human Second Trimester Pregnancy Is Induced by Progesterone and 17β-Estradiol
Authors: Mjösberg Jenny , Svensson Judit , Johansson Emma , Hellström Lotta , Casas Rosaura , Jenmalm Maria C. , Boij Roland , Matthiesen Leif , Jönsson Jan-Ingvar , Berg Göran , Ernerudh Jan
Published: June 2009

CD4+CD25high regulatory T cells (Tregs) are implicated in the maintenance of murine pregnancy. However, reports regarding circulating Treg frequencies in human pregnancy are inconsistent, and the functionality and phenotype of these cells in pregnancy have not been clarified. The aim of this study was to determine the frequency, phenotype, and function of circulating Tregs in the second trimester of human pregnancy and the influence of progesterone and 17β-estradiol on Treg phenotype and frequency. Based on expressions of Foxp3, CD127, and HLA-DR as determined by multicolor flow cytometry, we defined a proper CD4dimCD25high Treg population and showed, in contrast to most previous reports, that this population was reduced in second trimester of pregnancy. Unexpectedly, Foxp3 expression was decreased in the Treg, as well as in the CD4+ population. These changes could be replicated in an in vitro system resembling the pregnancy hormonal milieu, where 17β-estradiol, and in particular progesterone, induced, in line with the pregnancy situation, a reduction of CD4dimCD25highFoxp3+ cells in PBMC from nonpregnant women. By coculturing FACS-sorted Tregs and autologous CD4+CD25− responder cells, we showed that Tregs from pregnant women still displayed the same suppressive capacity as nonpregnant women in terms of suppressing IL-2, TNF-α, and IFN-γ secretion from responder cells while efficiently producing IL-4 and IL-10. Our findings support the view of hormones, particularly progesterone, as critical regulators of Tregs in pregnancy. Furthermore, we suggest that in the light of the results of this study, early data on circulating Treg frequencies in pregnancy need reevaluation.
STAT6 Activation Confers upon T Helper Cells Resistance to Suppression by Regulatory T Cells
Authors: Pillemer Brendan B. L. , Qi Zengbiao , Melgert Barbro , Oriss Timothy B. , Ray Prabir , Ray Anuradha
Published: June 2009

Recent studies have highlighted characteristics of T regulatory cells (Tregs) that underlie their suppressive function. However, mechanisms that override their suppressive function in the context of an adaptive immune response are not well understood. In the lungs of mice undergoing allergic inflammation, appreciable numbers of Tregs were identified that possessed suppressive function when assayed ex vivo. We investigated whether the Th2-promoting cytokine IL-4 played a permissive role that superseded Treg function, thereby allowing the development of allergic inflammation. IL-4 signaling via the IL-4Rα-STAT6 axis was required to maintain Foxp3 expression in Tregs and promote their proliferation. However, the results of both in vivo experiments involving adoptive transfer of Tregs into Ag-sensitized vs naive animals and in vitro suppression assays performed with or without exogenous IL-4 showed the ability of IL-4 to compromise Treg-mediated suppression. Use of retrovirally expressed, constitutively active STAT6 revealed that the underlying mechanism was not IL-4-mediated dysfunction of Tregs but involved the resistance of Th cells to Treg-mediated suppression that would permit the development of an adaptive immune response. Our data suggest that infectious tolerance, mediated by membrane-bound TGF-β expressed by Tregs, is compromised by the competing effects of IL4-induced signaling in naive CD4+ Th cells.
Restricted Autoantigen Recognition Associated with Deletional and Adaptive Regulatory Mechanisms
Authors: Gebe John A. , Yue Betty B. , Unrath Kelly A. , Falk Ben A. , Nepom Gerald T.
Published: June 2009

Autoimmune diabetes (T1D) is characterized by CD4+ T cell reactivity to a variety of islet-associated Ags. At-risk individuals, genetically predisposed to T1D, often have similar T cell reactivity, but nevertheless fail to progress to clinically overt disease. To study the immune tolerance and regulatory environment permissive for such autoreactive T cells, we expressed TCR transgenes derived from two autoreactive human T cells, 4.13 and 164, in HLA-DR4 transgenic mice on a C57BL/6-derived “diabetes-resistant” background. Both TCR are responsive to an immunodominant epitope of glutamic acid decarboxylase 65555–567, which is identical in sequence between humans and mice, is restricted by HLA-DR4, and is a naturally processed self Ag associated with T1D. Although both TCR use the identical Vα and Vβ genes, differing only in CDR3, we found stark differences in the mechanisms utilized in vivo in the maintenance of immune tolerance. A combination of thymic deletion (negative selection), TCR down-regulation, and peripheral activation-induced cell death dominated the phenotype of 164 T cells, which nevertheless still maintain their Ag responsiveness in the periphery. In contrast, 4.13 T cells are much less influenced by central and deletional tolerance mechanisms, and instead display a peripheral immune deviation including differentiation into IL-10-secreting Tr1 cells. These findings indicate a distinct set of regulatory alternatives for autoreactive T cells, even within a single highly restricted HLA-peptide-TCR recognition profile.
T-bet-Deficient NOD Mice Are Protected from Diabetes Due to Defects in Both T Cell and Innate Immune System Function
Authors: Esensten Jonathan H. , Lee Michael R. , Glimcher Laurie H. , Bluestone Jeffrey A.
Published: June 2009

The transcription factor T-bet (Tbx21) is critical for Th1 polarization of CD4+ T cells. Genetic deletion of Tbx21 can cause either exacerbation or attenuation of different autoimmune diseases in animal models. In the nonobese diabetic (NOD) mouse, genetic deletion of the Ifng or the Il12b (IL-12p40) genes, which are both critical Th1 cytokines, does not reduce the incidence of autoimmune diabetes. These results suggest that autoimmune diabetes in the NOD may not be a Th1-driven disease. However, we report that Tbx21 deficiency in the NOD mouse completely blocks insulitis and diabetes due to defects both in the initiation of the anti-islet immune response and in the function of CD4+ effector T cells. We find defective priming of naive islet-reactive T cells by the innate immune system in Tbx21−/− animals. By contrast to naive cells, activated islet-reactive BDC2.5 TCR-transgenic T cells do not require Tbx21 in recipient animals for efficient adoptive transfer of diabetes. However, when these BDC2.5 TCR-transgenic effector cells lack Tbx21, they are less effective at entering the pancreas and promoting diabetes than Tbx21+/+ cells. Tbx21−/− regulatory T cells function normally in vitro and diabetes can be restored in Tbx21−/− mice by reducing regulatory T cell numbers. Thus, the absence of diabetes in the NOD.Tbx21−/− is due to intrinsic defects in both T cells and cells of the innate immune system paired with the relative preservation of regulatory T cell function.
Expression of IL-24, an Activator of the JAK1/STAT3/SOCS3 Cascade, Is Enhanced in Inflammatory Bowel Disease
Authors: Andoh Akira , Shioya Makoto , Nishida Atsushi , Bamba Shigeki , Tsujikawa Tomoyuki , Kim-Mitsuyama Shokei , Fujiyama Yoshihide
Published: June 2009

IL-24 is a member of the IL-10 family of cytokines. In this study, we investigated IL-24 expression in the inflamed mucosa of patients with inflammatory bowel disease (IBD), and characterized the molecular mechanisms responsible for IL-24 expression in human colonic subepithelial myofibroblasts (SEMFs). IL-24 expression in the IBD mucosa was evaluated by immunohistochemical methods. IL-24 mRNA and protein expression was determined by real-time PCR and ELISA, respectively. AP-1 and C/EBP DNA-binding activity and IL-24 promoter activity were assessed by EMSA analysis and a reporter gene assay, respectively. IL-24 mRNA expression was significantly elevated in active lesions from patients who have ulcerative colitis and Crohn’s disease. Colonic SEMFs were identified as a major source of IL-24 in the mucosa. IL-1β, but not IL-17A, TNF-α, or IFN-γ, significantly enhanced IL-24 mRNA and protein expression in isolated colonic SEMFs. The IL-1β-induced IL-24 mRNA expression was mediated by the activation of the transcription factors, AP-1 and C/EBP-β. Induction of IL-24 mRNA stabilization was also involved in the effects of IL-1β. IL-24 induced JAK1/STAT-3 phosphorylation and SOCS3 expression in HT-29 colonic epithelial cells. IL-24 did not modulate the proliferation of HT-29 cells, but significantly increased the mRNA expression of membrane-bound mucins (MUC1, MUC3, and MUC4). IL-24 derived from colonic SEMFs acts on colonic epithelial cells to elicit JAK1/STAT-3 activation and the expression of SOCS3 and mucins, supporting their suppressive effects on mucosal inflammation in IBD.
Fusion Loop Peptide of the West Nile Virus Envelope Protein Is Essential for Pathogenesis and Is Recognized by a Therapeutic Cross-Reactive Human Monoclonal Antibody
Authors: Sultana Hameeda , Foellmer Harald G. , Neelakanta Girish , Oliphant Theodore , Engle Michael , Ledizet Michel , Krishnan Manoj N. , Bonafé Nathalie , Anthony Karen G. , Marasco Wayne A. , Kaplan Paul , Montgomery Ruth R. , Diamond Michael S. , Koski Raymond A. , Fikrig Erol
Published: June 2009

West Nile virus is an emerging pathogen that can cause fatal neurological disease. A recombinant human mAb, mAb11, has been described as a candidate for the prevention and treatment of West Nile disease. Using a yeast surface display epitope mapping assay and neutralization escape mutant, we show that mAb11 recognizes the fusion loop, at the distal end of domain II of the West Nile virus envelope protein. Ab mAb11 cross-reacts with all four dengue viruses and provides protection against dengue (serotypes 2 and 4) viruses. In contrast to the parental West Nile virus, a neutralization escape variant failed to cause lethal encephalitis (at higher infectious doses) or induce the inflammatory responses associated with blood-brain barrier permeability in mice, suggesting an important role for the fusion loop in viral pathogenesis. Our data demonstrate that an intact West Nile virus fusion loop is critical for virulence, and that human mAb11 targeting this region is efficacious against West Nile virus infection. These experiments define the molecular determinant on the envelope protein recognized by mAb11 and demonstrate the importance of this region in causing West Nile encephalitis.
Macrophage Delivery of Nanoformulated Antiretroviral Drug to the Brain in a Murine Model of NeuroAIDS
Authors: Dou Huanyu , Grotepas Cassi B. , McMillan JoEllyn M. , Destache Christopher J. , Chaubal Mahesh , Werling Jane , Kipp James , Rabinow Barrett , Gendelman Howard E.
Published: June 2009

Antiretroviral therapy (ART) shows variable blood-brain barrier penetration. This may affect the development of neurological complications of HIV infection. In attempts to attenuate viral growth for the nervous system, cell-based nanoformulations were developed with the focus on improving drug pharmacokinetics. We reasoned that ART carriage could be facilitated within blood-borne macrophages traveling across the blood-brain barrier. To test this idea, an HIV-1 encephalitis (HIVE) rodent model was used where HIV-1-infected human monocyte-derived macrophages were stereotactically injected into the subcortex of severe combined immunodeficient mice. ART was prepared using indinavir (IDV) nanoparticles (NP, nanoART) loaded into murine bone marrow macrophages (BMM, IDV-NP-BMM) after ex vivo cultivation. IDV-NP-BMM was administered i.v. to mice resulting in continuous IDV release for 14 days. Rhodamine-labeled IDV-NP was readily observed in areas of HIVE and specifically in brain subregions with active astrogliosis, microgliosis, and neuronal loss. IDV-NP-BMM treatment led to robust IDV levels and reduced HIV-1 replication in HIVE brain regions. We conclude that nanoART targeting to diseased brain through macrophage carriage is possible and can be considered in developmental therapeutics for HIV-associated neurological disease.
T-bet Knockout Prevents Helicobacter felis-Induced Gastric Cancer
Authors: Stoicov Calin , Fan Xueli , Liu Jian Hua , Bowen Glennice , Whary Mark , Kurt-Jones Evelyn , Houghton JeanMarie
Published: June 2009

Helicobacter infection is the primary risk factor for gastric cancer, with the cytokine environment within the gastric mucosa the strongest predictor of disease risk. Elevated TNF-α, IL-1β, and low IL-10 are associated with the highest risk. In this study, we used C57BL/6 mice to identify T-bet as a central regulator of the cytokine environment during Helicobacter felis infection. We infected male and female C57BL/6 and C57BL/6-T-bet knockout (KO) liter mates with H. felis and examined the bacterial colonization, immune response, and mucosal damage at varying time points. T-bet KO mice maintained infection for 15 mo at similar levels to wild-type mice. Infection and immune response did not differ between male and female mice. Despite sustained infection, T-bet KO mice respond with a blunted Th1 response associated with preservation of parietal and chief cells and protection from the development of gastric cancer. Unexpectedly, T-bet KO mice develop a gastric environment that would not be expected based on the phenotype of T-bet KO CD4 cells alone. T-bet KO mice respond to H. felis infection with a markedly blunted IL-1β and TNF-α and elevated IL-10 levels. Activity of this one master regulator modulates the expression of the key gastric mucosal cytokines associated with gastric cancer and may be a target for therapy to restore immune balance clinically in patients at risk for gastric cancer.
Binding of Submaximal C1q Promotes Complement-Dependent Cytotoxicity (CDC) of B Cells Opsonized with Anti-CD20 mAbs Ofatumumab (OFA) or Rituximab (RTX): Considerably Higher Levels of CDC Are Induced by OFA than by RTX
Authors: Pawluczkowycz Andrew W. , Beurskens Frank J. , Beum Paul V. , Lindorfer Margaret A. , van de Winkel Jan G. J. , Parren Paul W. H. I. , Taylor Ronald P.
Published: June 2009

The CD20 mAb ofatumumab (OFA) is more effective than rituximab (RTX) in promoting complement-dependent cytotoxicity (CDC) of B cells via the classical pathway (CP) of complement. CP activation is initiated by C1q binding to cell-bound IgG. Therefore, we examined the role of C1q in the dynamics of complement activation and CDC of B cell lines and primary cells from patients with chronic lymphocytic leukemia, reacted with OFA or RTX. C1q binding, complement activation, and colocalization of C1q with cell-bound mAbs were determined by flow cytometry and high-resolution digital imaging. C1q binds avidly to OFA-opsonized Raji and Daudi cells (KD = 12–16 nM) and colocalizes substantially with cell-bound OFA. Cells opsonized with OFA undergo high levels of complement activation and CDC in C1q-depleted serum supplemented with low concentrations of C1q. Under comparable conditions, RTX-opsonized cells bind less C1q; in addition, even when higher concentrations of C1q are used to achieve comparable C1q binding to RTX-opsonized cells, less complement activation and CDC are observed. Greater CDC induced by OFA may occur because C1q is bound in close proximity and with high avidity to OFA, resulting in effective CP activation. Moreover, OFA binds to the small, extracellular CD20 loop, placing the mAb considerably closer to the cell membrane than does RTX. This may facilitate effective capture and concentration of activated complement components closer to the cell membrane, potentially shielding them from inactivation by fluid phase agents and promoting efficient generation of the membrane attack complex.
Cutting Edge: B and T Lymphocyte Attenuator Signaling on NKT Cells Inhibits Cytokine Release and Tissue Injury in Early Immune Responses
Authors: Miller Mendy L. , Sun Yonglian , Fu Yang-Xin
Published: June 2009

The role of coinhibition in an immune response is thought to be critical for the contraction of an adaptive immune response in its waning phases. We present evidence that B and T lymphocyte attenuator (BTLA) coinhibitory signaling is required to temper early inflammation. Using an in vivo Con A challenge model of acute hepatitis, we observed reduced survival and increased early serum cytokine secretion in BTLA−/− mice as compared with wild-type mice. In vitro, liver mononuclear cells from BTLA−/− mice are hyperresponsive to anti-CD3, Con A, and α-galactosylceramide stimulation and secrete higher levels of TNF-α, IFN-γ, IL-2, and IL-4. We found this was in part due to negative regulation of NKT cells by BTLA, as early cytokine inhibition from whole liver mononuclear cells or purified NKT cells depends upon BTLA signaling. Overall, our data demonstrate that coinhibition is active in early immune responses through BTLA regulation of NKT cells.
Chemotherapeutic Agents in Noncytotoxic Concentrations Increase Antigen Presentation by Dendritic Cells via an IL-12-Dependent Mechanism
Authors: Shurin Galina V. , Tourkova Irina L. , Kaneno Ramon , Shurin Michael R.
Published: June 2009

Antineoplastic chemotherapeutic agents may indirectly activate dendritic cells (DCs) by inducing the release of “danger” signals from dying tumor cells. Whereas the direct cytotoxic or inhibitory effect of conventional chemotherapy on DCs has been reported, modulation of DC function by chemotherapeutic agents in low noncytotoxic concentrations has not yet been investigated. We have tested the effects of different classes of antineoplastic chemotherapeutic agents used in low noncytotoxic concentrations on the Ag-presenting function of DCs. We revealed that paclitaxel, doxorubicin, mitomycin C, and methotrexate up-regulated the ability of DCs to present Ags to Ag-specific T cells. Stimulation of DC function was associated with the up-regulation of expression of Ag-processing machinery components and costimulatory molecules on DCs, as well as increased IL-12p70 expression. However, the ability of DCs treated with paclitaxel, methotrexate, doxorubicin, and vinblastine to increase Ag presentation to Ag-specific T cells was abolished in DCs generated from IL-12 knockout mice, indicating that up-regulation of Ag presentation by DCs is IL-12-dependent and mediated by the autocrine or paracrine mechanisms. At the same time, IL-12 knockout and wild-type DCs demonstrated similar capacity to up-regulate OVA presentation after their pretreatment with low concentrations of mitomycin C and vincristine, suggesting that these agents do not utilize IL-12-mediated pathways in DCs for stimulating Ag presentation. These findings reveal a new mechanism of immunopotentiating activity of chemotherapeutic agents—a direct immunostimulatory effect on DCs (chemomodulation)—and thus provide a strong rationale for further assessment of low-dose chemotherapy given with DC vaccines for cancer treatment.
A composite score for a measuring instrument utilising re-scaled Likert values and item weights from matrices of pairwise ratios
Authors: Becker Piet J. , Wolvaardt Jacobus S. , Hennessy Angie , Maree Carin
Published: June 2009

A methodology is proposed to develop a measuring instrument (metric) for evaluating subjects from a population that cannot provide data to facilitate the development of such a metric (e.g. pre-term infants in the neonatal intensive care unit). Central to this methodology is the employment of an expert group that decides on the items to be included in the metric, the weights assigned to these items, and an index associated with the Likert scale points for each item. The experts supply pairwise ratios of an importance between items, and the geometric mean method is applied to these to establish the item weights – a well-established procedure in multi-criteria decision analysis. The ratios are found by having a managed discussion before asking the members of the expert panel to mark a visual analogue scale for each item.Opsomming‘n Metode word aangebied waarmee ‘n meetinstrument (metriek) ontwikkel kan word vir die evaluering van persone uit ‘n populasie wat nie self die data vir die ontwikkeling van die metriek kan voorsien nie (bv. vroeggebore babas in die neonatale intensiewe sorgeenheid). Die kern van hierdie werkswyse is die gebruik van ‘n deskundige groep wat die items vir die meetinstrument kies, gewigte aan die items toeken, en vir elke item ‘n indeks opstel wat met die Likert-skaal punte geassosieer word. Die deskundiges het paarsgewyse verhoudings tussen items verskaf en die meetkundig-gemiddelde metode is hierop toegepas om die itemgewigte te verkry – ‘n goedgevestigde gebruik in meerdoelwitbesluitkunde. Die paarsgewyse verhoudings is gewerf deur die deskundiges, na ‘n bestuurde bespreking, vir elke item ‘n visuele analoogskaal te laat invul.
Premenstrual symptoms and remedies practiced by Malaysian women attending a rural primary care clinic
Authors: Omar Khairani , Mohsin Siti S. , Muthupalaniappen Leelavathi , Idris Idayu B. , Amin Rahmah M. , Shamsudin Khadijah
Published: June 2009

Background: Premenstrual symptoms affect about 40% of women of reproductive age. In an effort to alleviate premenstrual symptoms, affected women practice various remedial approaches. The aim of this study was to assess the prevalence and severity of premenstrual symptoms experienced by women, the associated factors and the remedial approaches practiced by them.Method: This was a cross-sectional study conducted at a rural primary care clinic situated in Hulu Langat, Malaysia. All women of reproductive age (18 to 44 years old) attending the clinic during the study period and who fit the selection criteria were included. Premenstrual symptoms and severity were assessed using a self-report questionnaire, the Shortened Premenstrual Assessment Form (SPAF). It consists of 10 items that measure changes in mood, behaviour and physical symptoms. The respondents were also asked if they had used any remedy to relieve their symptoms.Results: A total of 158 women were included in the study. The majority of the respondents were Malay (70.3%), followed by Indian (16.5%) and Chinese (10.8%) women. About 75% of the women experienced at least one of the premenstrual symptoms. Approximately 7% of them reported experiencing severe symptoms in all three subscales of the SPAF. The frequently reported symptoms were body ache (75.3%), abdominal pain (75.3%), irritable feeling (63.9%) and breast discomfort (61.4%). The symptom score was higher among Malay women (p = 0.034), and those with a higher household income (p = 0.037) and higher educational level (p = 0.01). There was no significant association between premenstrual symptoms and age, marital status, menstrual cycle and age of menarche. The common remedies used were vitamins (19%), a healthy diet (15.8%) and analgesics (13.3%). Approximately 60% of the women did not use any remedy to reduce their premenstrual symptoms.Conclusion: Premenstrual symptoms were common among women attending the clinic. The symptoms affect them significantly both physically and emotionally. Thus, it is essential for primary care providers to take an active role in identifying, educating and managing premenstrual symptoms among women.