bluuebunny/crossref_metadata_2025 huggingface dataset:
Ventral tail bud mesenchyme is a signaling center for tail paraxial mesoderm induction
Authors: Liu Chunqiao , Knezevic Vladimir , Mackem Susan
Published: February 2004

A large body of evidence from several systems indicates that formation of the vertebrate tail is morphogenetically continuous with gastrulation, including neural inducing activity in descendants of the gastrula organizer. However, the signaling centers and molecular events regulating tail mesoderm induction and its organized elongation remain poorly defined. In mammals, the ventral ectoderm ridge (VER) is essential to maintain ongoing formation of paraxial mesoderm and somitogenesis in cultures of intact tail. Avian tail buds contain a similar VER structure. Here, we report that the chick ventral tail bud operates as a signaling center for paraxial mesoderm induction. By using “organizer” style grafting assays to early host embryos, we found that ventral tail bud was able to induce elongated paraxial mesodermal extensions and that the ventral tail bud mesenchyme underlying the VER is both necessary and sufficient for the induction in this assay system. Our observations combined with those of others suggest that interplay between several different signaling centers in the amniote tail bud regulates the coordinate induction and elongation of axial and paraxial structures in the developing tail. Developmental Dynamics 229:600–606, 2004. Published 2004 Wiley‐Liss, Inc. © 2004 Wiley‐Liss, Inc.
Specificity of self‐concept disturbances in eating disorders
Authors: Jacobi Corinna , Paul Thomas , de Zwaan Martina , Nutzinger Detlef O. , Dahme Bernhard
Published: February 2004

Objectives

The current study examined self‐concept deficits among three diagnostic groups of eating‐disordered patients, evaluated the relationship between self‐concept deficits and depression, and addressed the specificity of self‐concept deficits in eating‐disordered patients.

Method

Three groups of eating‐disordered patients (anorexia nervosa, N = 33; bulimia nervosa, N = 38; binge eating disorder, N = 28) were first compared to three matched healthy control groups and then to two psychiatric comparison groups (patients with anxiety disorders, N = 37; patients with depressive disorders, N = 37).

Results

All three groups of eating‐disordered patients displayed lower self‐esteem and higher feelings of ineffectiveness compared with the healthy controls, even after controlling for depression. Differences in self‐esteem and ineffectiveness were also found between eating‐disordered patients and psychiatric controls. However, not all of the differences were significant. In addition, the psychiatric controls also exhibited lower self‐esteem than normative samples.

Discussion

Findings suggest that self‐concept deficits are more pronounced in eating‐disordered patients but cannot be regarded as highly specific. © 2004 by Wiley Periodicals, Inc. Int J Eat Disord 35: 204–210, 2004.
Eating disorders symptomatology and inpatient treatment experience in eating‐disordered subjects
Authors: Milos Gabriella , Spindler Anja , Buddeberg Claus , Ruggiero Giovanni
Published: February 2004

Objective

This study aimed to examine whether eating disorder (ED) subjects with and without a history of inpatient treatment differ in the severity of symptoms as measured by the Eating Disorders Inventory (EDI‐1).

Method

In a sample of 222 women (66 women with anorexia nervosa, 126 women with bulimia nervosa, and 30 women with eating disorders not otherwise specified), the history of inpatient treatment was assessed and the EDI was administered.

Results

Fifty percent of the participants had received previous inpatient treatment. The group with past inpatient treatment had significantly higher scores on the EDI subscales Body Dissatisfaction, Ineffectiveness, and Interpersonal Distrust than the group without inpatient treatment experience.

Discussion

ED subjects with and without inpatient treatment showed different profiles on the EDI subscales. The fact that these two groups differ in specific ED symptoms may represent a bias in ED studies when samples with heterogeneous treatment contact history are recruited. © 2004 by Wiley Periodicals, Inc. Int J Eat Disord 35: 161–168, 2004.
An evaluation of web‐based information
Authors: Murphy Rebecca , Frost Susie , Webster Peter , Schmidt Ulrike
Published: February 2004

Objective

To evaluate the quality of web‐based information on the treatment of eating disorders and to investigate potential indicators of content quality.

Method

Two search engines were queried to obtain 15 commonly accessed websites about eating disorders. Two reviewers evaluated the characteristics, quality of content, and accountability of the sites. Intercorrelations between variables were calculated.

Results

The overall quality of the sites was poor based on the outcome measures used. All quality of content measures correlated with a measure of accountability (Silberg, W.M., Lundberg, G.D., & Mussachio, R.A., 1993).

Discussion

There is a lack of quality information on the treatment of eating disorders on the web. Although accountability criteria may be useful indicators of content quality, there is a need to investigate whether these can be usefully applied to other mental health areas. © 2004 by Wiley Periodicals, Inc. Int J Eat Disord 35: 145–154, 2004.
The use of herbal remedies by adolescents with eating disorders
Authors: Trigazis Leo , Tennankore Dhenuka , Vohra Sunita , Katzman Debra K.
Published: February 2004

Objective

To determine the frequency and type of herbal remedies and the reasons for herbal remedy use by adolescents with eating disorders.

Methods

Forty‐six female adolescent females (age range, 10–17 years; mean age, 15 ± 1.3 years) in a tertiary‐care pediatric eating disorder treatment center from May 1998 to July 2000 volunteered for this cross‐sectional study. They met the criteria for anorexia nervosa, bulimia nervosa, or eating disorder not otherwise specified. Participants completed a 92‐item self‐administered questionnaire. We summarized information on demographics, use of herbal remedies, knowledge of safety issues of herbal remedies, and trust in the health care system.

Results

Of these 46 subjects, 17 (37%) used herbal remedies. Of these 17 subjects, 35% (6 of 17) used herbal remedies to decrease their appetites and to induce vomiting, 41% (7 of 17) knew nothing about herbal remedies, despite their use of these products, and 24% (4 of 17) reported that their physicians asked whether they used herbal remedies. The participants did not use herbal remedies because of their dissatisfaction with allopathic medicine.

Discussion

Adolescents with eating disorders frequently used herbal remedies for both weight control and non—weight control purposes. They did not regularly inform their physicians about their use of herbal remedies and physicians did not regularly inform their patients about this use. The generally high prevalence of herbal remedy use in this population suggests that health care providers need to be knowledgeable and should enquire about patients' use of these products. The perceived benefits, adverse effects, and herb‐drug interactions of self‐prescribed herbal remedies consumed by adolescents with eating disorders are unknown and further research is needed. © 2004 by Wiley Periodicals, Inc. Int J Eat Disord 35: 223–228, 2004.
Persistence of nutritional deficiencies after short‐term weight recovery in adolescents with anorexia nervosa
Authors: Castro Josefina , Deulofeu Ramón , Gila Araceli , Puig Josefina , Toro Josep
Published: February 2004

Objectives

To study nutritional abnormalities in adolescent anorexia nervosa and to establish whether certain abnormalities persist after short‐term refeeding.

Method

Sixty‐one patients (10–19 years old) admitted to a reference unit for eating disorders between 1999 and 2000 with a diagnosis of anorexia nervosa were evaluated at admission and at discharge. A range of biochemical, nutritional, and hormonal parameters were determined.

Results

At admission, no protein or lipid deficiencies were found, although many patients presented with hormonal abnormalities and red blood cell folate and zinc deficiencies. Hormonal abnormalities reverted significantly (p < .000) after renutrition. There were decreases in erythrocytes and in levels of hemoglobin (p < .000) and folic acid (p < .05). Red blood cell folate and zinc increased but did not reach normal levels.

Conclusions

In a large proportion of adolescent anorexic patients, supplementation of folic acid and zinc is recommended although protein or hormonal replacement does not seem to be necessary. © 2004 by Wiley Periodicals, Inc. Int J Eat Disord 35: 169–178, 2004.
Undue influence of weight on self‐evaluation: A population‐based twin study of gender differences
Authors: Reichborn‐Kjennerud Ted , Bulik Cynthia M. , Kendler Kenneth S. , Roysamb Espen , Tambs Kristian , Torgersen Svenn , Harris Jennifer R.
Published: February 2004

Objective

To explore the extent to which genetic and environmental factors contribute to liability to placing undue importance on weight as an indicator of self‐evaluation and to determine whether differences exist across genders in the nature and magnitude of these effects.

Method

Self‐report data were collected on 8,045 same‐sex and opposite‐sex twins, aged 18–31 years, from a population‐based registry of Norwegian twins. Structural equation modeling was utilized to estimate the relative contribution of genetic and environmental factors to liability for undue influence of weight on self‐evaluation, allowing for gender‐specific effects.

Results

Individual variation in undue influence of weight on self‐evaluation was best explained by shared and individual environmental influences. No significant gender differences were found. Shared environmental factors accounted for 31% of the variance.

Discussion

These results raise the possibility that there may be distinct sources of familial resemblance for different symptoms of bulimia nervosa as codified in the 4th ed. of the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 1994). © 2004 by Wiley Periodicals, Inc. Int J Eat Disord 35: 123–132, 2004.
The cost‐effectiveness of anorexia nervosa treatment
Authors: Crow Scott J. , Nyman John A.
Published: February 2004

Objective

Anorexia nervosa (AN) is an expensive‐to‐treat illness with a high mortality rate. Some health care systems have limited the amount of treatment provided for AN despite the lack of clearly documented efficacy for these limited‐intensity approaches. One method that can inform decisions about AN treatment is cost‐effectiveness analysis.

Method

Cost‐modeling analysis was used to estimate the incremental cost‐effectiveness of AN treatment. Modeling was chosen given the lack of primary data on costs and outcomes in AN treatment. Data for age of onset, life expectancy, and disease‐associated mortality were taken from the literature. The costs of treatment used in the analysis were those in use at the University of Minnesota.

Results

Assuming an approach consisting of inpatient weight restoration, followed by treatment of gradually diminishing intensity (partial hospitalization, then outpatient psychotherapy plus medication management), incremental cost‐effectiveness ratios were calculated and compared with a limited intensity, “usual care” model. These assumptions yielded a cost per year of life saved of $30,180.

Discussion

Relative to many other medical interventions, the comprehensive treatment of AN appears to be quite cost‐effective in terms of cost per year of life saved. Such data may have an impact on payer decisions and underscore the serious nature of AN. © 2004 by Wiley Periodicals, Inc. Int J Eat Disord 35: 155–160, 2004.
Differential chemokine activation of CC chemokine receptor 1‐regulated pathways: ligand selective activation of Gα 14‐coupled pathways
Authors: Tian Yaji , New David C. , Yung Lisa Y. , Allen Rodger A. , Slocombe Patrick M. , Twomey Breda M. , Lee Maggie M. K. , Wong Yung H.
Published: February 2004

Chemokines regulate the chemotaxis, development, and differentiation of many cell types enabling the regulation of routine immunosurveillance and immunological adaptation. CC chemokine receptor 1 (CCR1) is the target of 11 chemokines. This promiscuity of receptor‐ligand interactions and the potential for functional redundancy has led us to investigate the selective activation of CCR1‐coupled pathways by known CCR1 agonists. Chemokines leukotactin‐1, macrophage inflammatory protein (MIP)‐1α, monocyte chemotactic peptide (MCP)‐3, RANTES, and MIP‐1δ all inhibited adenylyl cyclase activity in cells transiently transfected with CCR1. In contrast, only MIP‐1δ was unable to signal via G14‐, G16‐ or chimeric 16z44‐coupled pathways. In a stable cell line expressing CCR1 and Gα14, all of these five chemokines along with hemofiltrate CC chemokine (HCC)‐1 and myeloid progenitor inhibitory factor (MPIF)‐1 were able to stimulate Gi/o‐coupled pathways, but MIP‐1δ, HCC‐1 and MPIF‐1 were unable to activate G14‐mediated stimulation of phospholipase Cβ activity. In addition, MIP‐1δ was unable to promote the phosphorylation of extracellular signal‐regulated kinase and c‐Jun N‐terminal kinase. This suggests that different chemokines are able to selectively activate CCR1‐coupled pathways, probably because of differentintrinsic ligand efficacies. CCR1 and Gα14 or Gα16 are co‐expressed in several cell types and we hypothesize that selective activation of chemokine receptors provides a mechanism by which chemokines are able to fine‐tune intracellular signaling pathways.
Expression and function of 4‐1BB during CD4 versus CD8 T cell responses in vivo
Authors: Dawicki Wojciech , Watts Tania H.
Published: February 2004

4‐1BBL–/– mice have a defect in recall CD8+ T cell responses to viruses, whereas CD4+ T cell responses to virus are unimpaired in these mice. In contrast, both CD4+ and CD8+ T cells respond to 4‐1BB ligand (4‐1BBL) in vitro. To clarify the role of 4‐1BB/4‐1BBL in CD4+ versus CD8+ T cell responses in vivo, wecompared CD4 (OT‐II) and CD8 (OT‐I) TCR transgenic T cells responding to the same antigen in an in vivo adoptive transfer model in 4‐1BBL+/+ versus 4‐1BBL–/– mice. Duringprimary and secondary responses, expression of 4‐1BB on in vivo‐activated TCR transgenic T cells was earlier and more transient than previously observed in vitro, correlating withexpression of the early activation antigen CD69 and preceding the transition to the CD44hi state. Although 4‐1BB is expressed early in the primary response, there was no effect of 4‐1BBL deficiency on initial CD8 T cell expansion and only a minor effect on initial CD4 T cell expansion. The major effect of 4‐1BB/4‐1BBL interaction is on the T cell recall response. This is due to effects of 4‐1BBL on maintenance of T cell numbers at the end of the primary response with additional effects of 4‐1BBL on secondary expansion of T cells.
The human antibody response to pneumococcal capsular polysaccharides is dependent on the CD40‐CD40 ligand interaction
Authors: Jeurissen Axel , Wuyts Greet , Kasran Ahmad , Ramdien‐Murli Seema , Blanckaert Norbert , Boon Louis , Ceuppens Jan L. , Bossuyt Xavier
Published: February 2004

Protection against infections with Streptococcus pneumoniae is mediated by antibodies against the capsular polysaccharides (caps‐PS). Here we show that in in vitro experiments CD4+ T lymphocytes stimulate and CD8+ T lymphocytes inhibit the human anti‐caps‐PS antibody response. Using antagonistic anti‐CD40 and antagonistic anti‐CD40 ligand (CD40L) monoclonal antibodies, we showed that the CD4+ T lymphocyte‐mediated stimulation is dependent on the CD40‐CD40L interaction. The role of CD40L was further illustrated by the observation that CD4+ T lymphocytes obtained from a patient with hyper‐IgM syndrome were unable to enhance the immune response to caps‐PS. Furthermore, CD4+ T lymphocytes from cord blood, which did not express CD40L in response to stimulation with caps‐PS, failed to stimulate the antibody response of adult B lymphocytes to caps‐PS.
These in vitro findings were confirmed by in vivo experiments in which SCID/SCID mice were reconstituted with human mononuclear cells. Furthermore, we showed that caps‐PS induce production of IL‐4, IL‐6, IL‐10, and IFN‐γ, and that thisenhanced production was inhibited by blocking the CD40‐CD40L interaction. This is the first demonstration that the human immune response to caps‐PS, which is markedly regulated by T lymphocytes, is dependent on the CD40‐CD40L interaction.
Two waves of antigen‐containing dendritic cells in vivo in experimental Leishmania major infection
Authors: Misslitz Ana Clara , Bonhagen Kerstin , Harbecke Dorothee , Lippuner Christoph , Kamradt Thomas , Aebischer Toni
Published: February 2004

Dendritic cells (DC) can induce Th1 cell differentiation by producing IL‐12. In experimental infection with Leishmania major, DC could differently respond to infection and induce Th1 cells in C57BL/6 but not BALB/c mice, and thus determine the resistance or susceptibility of these mice. We characterized L. major antigen‐containing DC in vivo in draining lymph nodes of both strains. Conventional experimental infection is shown to result in two waves of these DC and our data argue against a relevant genetic difference in the DC initiating the anti‐parasite Th cell response in these mice. In both strains the first wave of DC presented L. major antigens but was not infected, produced IL‐12 but induced disease‐mediating Th2 cells upon adoptive transfer. In contrast to current belief, this response was therefore not initiated by infected DC, which were only detected in the second wave. The kinetics of the two waves suggests that DC turnoverhas an important impact on antigen presentation during infections with complex pathogens.
Regulation of human IL‐18 gene expression: interaction of PU.1 with GC‐box binding protein is involved in human IL‐18 expression in myeloid cells
Authors: Koyama Noriko , Hoelzer Dieter , Ottmann Oliver G.
Published: February 2004

Interleukin‐18 (IL‐18) is a pro‐inflammatory cytokine which participates in host defense against a variety of infections as well as in chronic inflammation including autoimmune diseases. However, little is known about human IL‐18 regulation at the gene level. We have previously demonstrated that sodium butyrate, a bacterial fermentation product, induces IL‐18 production via the proximal region of the promoter. In this study we investigated the molecular mechanisms for basal and sodium butyrate‐induced expression of IL‐18 in human myeloid cells. Two regulatory regions, a consensus binding site for PU.1 and a GC‐rich region, are required for basal IL‐18 promoter activity in human myeloid cells. PU.1 bound to the PU.1 consensus binding site in electrophoretic mobility shift assays, and overexpression of PU.1 led to activation of the IL‐18 promoter through this site. Mutation analysis revealed that the GC‐rich region, but not PU.1 site, participates in sodium butyrate‐induced transactivation. Furthermore, DNA pull‐down experiments and the critical spacing of the two binding sites suggest that formation of a protein complex involving both cis elements and the respective binding proteins might be crucial for human IL‐18 expression.
IgD+IgM– B cells mount immune responses that exhibit altered antibody repertoire
Authors: Han Shuhua , Zhang Xuejun , Xu Renling , Finkelman Fred D. , Brombacher Frank , Zheng Biao
Published: February 2004

IgM and IgD expression during B cell development and differentiation is strictly and developmentally controlled. Although studies have suggested subtle differences in B cell activation, tolerance, and affinity maturation when antigens ligate cell membrane IgM or IgD, the mechanisms that may explain these differences remain unknown and no drastic differences in immune responses have been reported in mice whose B cells selectively lack IgM or IgD. We now show that the antibody repertoire in IgM–/– mice is dramatically altered during the primary response to phosphorylcholine.In IgM–/– mice, B cells that are activated and differentiate into antibody‐forming cells and germinal center B cells express VH genes other than the T15 genes that dominate in wild‐type mice. The kinetics of the antigen‐specific IgD primary antibody response in IgM–/– mice appears similar to that of IgG, but not to that of IgM in wild‐type mice. Thus, our studies demonstrate that differences in the roles played by IgM and IgD in regulating the responsiveness and differentiation of B lymphocytes can have major biological consequences during adaptive immune responses.
NKp46 defines a subset of bovine leukocytes with natural killer cell characteristics
Authors: Storset Anne K. , Kulberg Siri , Berg Ingvild , Boysen Preben , Hope Jayne C. , Dissen Erik
Published: February 2004

Natural killer (NK) cells have not previously been precisely identified or characterized in cattle or any other ruminant species. We have generated a monoclonal antibody against bovine NKp46, which is expressed exclusively by NK cells in man. NKp46+ cells comprised 1–10% of blood mononuclear cells in cattle, and did not stain with antibodies against CD3, CD4, TCR1, B cell or granulocyte markers. The majority of the NKp46+ cells expressed CD2, and a variable fraction also expressed CD8. The tissue distribution of NKp46+ cells in cattle was compatible with the tissue distribution of NK cells in other species. Bovine NKp46+ cells had typical, large granular lymphocyte morphology, and proliferated vigorously in response to bovine IL‐2 for a limited number of cell divisions. IL‐2‐activated NKp46+ cells killed the bovine kidney cell line MDBK. This cytotoxicity was inhibited by preincubation with antibody against NKp46. In a redirected lysis assay, IL‐2‐activated NKp46+ cells killed the FcγR+ target cell line P815 after preincubation with antibody against NKp46. Together, these data indicate that bovine NKp46 is anactivating receptor and demonstrate the existence of a subset of leukocytes in cattle that, in terms of surface markers, morphology and function, represent NK cells.
Generation of Vα14 NKT cells in vitro from hematopoietic precursors residing in bone marrow and peripheral blood
Authors: Shimamura Michio , Kobayashi Kumi , Watanabe Hiroko , Huang Yi‐Ying , Okamoto Naoki , Kanie Osamu , Goji Hiroshi , Kobayashi Masumi
Published: February 2004

We previously reported the generation of Vα14 invariant TCR+ (Vα14i) NK1.1+ natural killer T (NKT) cells in the cytokine‐activated suspension culture of murine fetal liver cells. In this study, we attempted to apply this finding to the induction of Vα14i NKT cell differentiation in the culture of hematopoietic precursors residing in bone marrow or peripheralblood. Preferential generation of NKT cells was found in the culture of Thy‐1+‐depleted bone marrow cells in the presence of culture supernatant from Con A‐stimulated spleen T cells and a combination of recombinant IL‐3, IL‐4, IL‐7 and GM‐CSF. NKT cell development from peripheral blood hematopoietic precursors was induced when they were cultured on stromal cell monolayers prepared from Thy‐1+‐depleted bone marrow or fetal liver cells, suggesting that certain environments derived from hematopoietic organs are required for the induction of NKT cells from precursors in vitro. A significant fraction of NKT cells generated in the culture were positive for staining with CD1–α‐galactosylceramide tetramer, indicating that Vα14i NKT cells were the major subset among the NKT cells. The present methods for obtaining NKT cells in the culture of bone marrow or peripheral blood cells are applicable to the treatment of patients suffering from diseases with numerical and functional disorders of NKT cells.
Chemokine production during hypersensitivity pneumonitis
Authors: Nance Stephanie , Cross Richard , Fitzpatrick Elizabeth
Published: February 2004

Hypersensitivity pneumonitis (HP) is an interstitial lung disease that develops following repeated exposure to inhaled particulate antigens. Individuals with HP develop lymphocytic alveolitis,granuloma formation, and fibrosis. HP is categorized as a Th1 disease, and granuloma formation is dependent on T cells and the Th1 cytokine IFN‐γ. We therefore hypothesized that the IFN‐γ‐inducible chemokines IP‐10, Mig, and I‐TAC, which are frequently associated with Th1 diseases, would play an important role in the pathogenesis of disease. We analyzed the expression of multiple chemokines in the lungs of wild‐type (WT) and IFN‐γ‐knockout (GKO) mice exposed to the particulate antigen Saccharopolyspora rectivirgula (SR). Our results demonstrate the production of IP‐10, Mig, and I‐TAC in WT mice during the development of HP, whereas GKO mice have reduced levels of IP‐10 and no Mig or I‐TAC mRNA in the lungs in response to SR exposure. The production of these chemokines is associated with an influx of CXCR3+/CD4+ T cells into lungs of WT mice, which is reduced in GKO mice. These results suggest that IFN‐γ mediates the recruitment of CXCR3+/CD4+ T cells into the lung via production of the chemokines IP‐10, Mig, and I‐TAC, resulting in granuloma formation.
Natural killer cell receptors in the horse: evidence for the existence of multiple transcribed LY49 genes
Authors: Takahashi Tomoko , Yawata Makoto , Raudsepp Terje , Lear Teri L. , Chowdhary Bhanu P. , Antczak Douglas F. , Kasahara Masanori
Published: February 2004

In rodents, the Ly49 family encodes natural killer (NK) receptors interacting with classical MHC class I molecules, whereas the corresponding receptors in primates are members of the killer cell immunoglobulin‐like receptor (KIR) family. Recent evidence indicates that the cattle, domestic cat, dog, and pig have a single LY49 and multiple KIR genes, suggesting that predominant NK receptors in most non‐rodent mammals might be KIR. Here, we show that the horse has at least six LY49 genes, five with an immunoreceptor tyrosine‐based inhibition motif (ITIM) and one with arginine in the transmembrane region. Interestingly, none of the horse KIR‐like cDNA clones isolated by library screening encoded molecules likely to function asNK receptors; four types of clones were KIR‐Ig‐like transcript (KIR‐ILT) hybrids and contained premature stop codons and/or frameshift mutations, and two putative allelic sequences predicting KIR3DL molecules had mutated ITIM. To our knowledge, this is the first report suggesting that non‐rodent mammals may use LY49 as NK receptors for classical MHC class I. We also show that horse spleen expresses ILT‐like genes with unique domain organizations. Radiation hybrid mapping and fluorescence in situ hybridization localized horse LY49 and KIR/ILT genes to chromosomes 6q13 and 10p12, respectively.
p53 regulates thymic Notch1 activation
Authors: Laws Amy M. , Osborne Barbara A.
Published: February 2004

Notch is crucial for multiple stages of T cell development, including the CD4+CD8+ double positive (DP)/CD8+ single positive (SP) transition, but regulation of Notchactivation is not well understood. p53 regulates Presenilin1 (PS1) expression, and PS1 cleaves Notch, releasing its intracellular domain (NIC), leading to the expression of downstream targets, e.g. the HES1 gene. We hypothesize that p53 regulates Notch activity during T cell development. We found that Notch1 expression and activation were negatively regulated by p53in several thymoma lines. Additionally, NIC was elevated in Trp53–/– thymocytes as compared to Trp53+/+ thymocytes. To determine if elevated Notch1 activation in Trp53–/– thymocytes had an effect on T cell development, CD4 and CD8 expression were analyzed. The CD4+ SP/CD8+ SP T cell ratio was decreased in Trp53–/– splenocytes and thymocytes. This alteration in T cell development correlated with the increased Notch1 activation observed in the absence of p53. These data indicate that p53 negatively regulates Notch1 activation during T cell development. Skewing of T cell development toward CD8+SP T cells in Trp53–/– mice is reminiscent of the phenotype of NIC‐overexpressing mice. Thus, we suggest that p53 plays a role in T cell development, in part by regulating Notch1 activation.
Frontline: Neuropilin‐1: a surface marker of regulatory T cells
Authors: Bruder Dunja , Probst‐Kepper Michael , Westendorf Astrid M. , Geffers Robert , Beissert Stefan , Loser Karin , von Boehmer Harald , Buer Jan , Hansen Wiebke
Published: February 2004

CD4+CD25+ regulatory T cells (Treg cells) control immune responsiveness to a large variety of antigens. The isolation and therapeutic manipulation of Treg cells requires the use of reliable surface receptors that are selectively up‐regulated in Treg cells. On the basis of global gene expression studies, we identified neuropilin‐1 (Nrp1) as a specific surface marker for CD4+CD25+ Treg cells. Nrp1, a receptor involved in axon guidance, angiogenesis, and the activation of T cells, is constitutively expressed on the surface of CD4+CD25+ Treg cells independently of their activation status. In contrast, Nrp1 expression is down‐regulated in naive CD4+CD25– T cells after TCR stimulation. Furthermore, CD4+Nrp1high T cells express high levels of Foxp3 and suppress CD4+CD25– T cells. Thus, Nrp1 constitutes a useful surface marker to distinguish Treg cells from both naive and recently activated CD4+CD25+ non‐regulatory T cells.
Frontline: GITR, a member of the TNF receptor superfamily, is costimulatory to mouse T lymphocyte subpopulations
Authors: Ronchetti Simona , Zollo Ornella , Bruscoli Stefano , Agostini Massimiliano , Bianchini Rodolfo , Nocentini Giuseppe , Ayroldi Emira , Riccardi Carlo
Published: February 2004

GITR (glucocorticoid‐induced TNFR family related gene) is a member of the TNFR superfamily (TNFRSF) that is expressed in different cell types, including T lymphocytes. Because of a high homology in its cytoplasmic region with other known costimulatory members of the TNFRSF, we investigated whether GITR played a costimulatory role in T lymphocyte subpopulations. Our results show that the proliferation response of CD8+ and CD4+ peripheral T cell subpopulations was potentiated when a GITR costimulus was added to an anti‐CD3 stimulus. Furthermore, expression of the main activation‐induced receptor (IL‐2Rα) and production of IL‐2 and IFN‐γ were increased more with a GITR costimulus than with anti‐CD3 alone. GITR stimulation also enhanced anti‐CD3‐induced ERK phosphorylation, suggesting that GITR is involved in MAPK‐pathway activation. Interestingly, CD4+CD25+ regulatory T cell (Treg cell) proliferation was triggered by the GITR costimulus; Treg cell proliferation was paralleled by the loss of the anergic phenotype and suppressor activity. Nevertheless, unstimulated GITR–/– CD4+CD25+ and GITR+/+ CD4+CD25+ cells were equally able to exert suppressor activity on CD4+CD25– responder cells. These results indicate a novel function for GITR as costimulatory molecule of T cell subsets.
Effects of CD25 monoclonal antibody on proliferative and effector functions of alloactivated human T cells in vitro
Authors: Rowshani Ajda T. , Uss Alena , Yong Si‐La , van Lier René A.W. , ten Berge Ineke J. M.
Published: February 2004

Prophylactic treatment with CD25 mAb has led to a significant decrease of acute rejection rates after renal transplantation. However, despite its inhibitory effect on T cell proliferation and effector functions, rejections still occur. To obtain more insight in persistent alloreactivity, we evaluated the effects of the chimeric IgG1κ CD25 mAb Basiliximab® on proliferation and differentiation of alloactivated T cells from healthy individuals in vitro. Moreover, the capacity of other members of the common cytokine‐receptor γ‐chain family to overcome the inhibitory effects of CD25 mAb was studied. The CD25 mAb appeared to limit expansion of alloreactive lymphocytes rather than blocking entry into cell cycle, and it did so irrespective of the previous antigen experience of the cells. Both CD4+ and CD8+ alloresponsive lymphocytes showed diminished intracellular expression of IFN‐γ, TNF‐α, perforin and granzyme B. Remarkably, cytotoxicity was completely abolished. IL‐7, IL‐15 and IL‐21 could bypass the inhibitory effects of the CD25 mAb on both proliferation and cytotoxicity. In conclusion, persistent alloreactivity in the presence of therapeutic concentrations of CD25 mAb may be caused by alloreactive T cells that still produce cytokines that can damage the allograft. In addition, other members of the common cytokine‐receptor γ‐chain family can rescue the proliferative and cytotoxic activity of these alloreactive T cells.
A New Route to Protected Acyloins and Their Enzymatic Resolution with Lipases
Authors: Scheid Günther , Kuit Wouter , Ruijter Eelco , Orru Romano V. A. , Henke Erik , Bornscheuer Uwe , Wessjohann Ludger A.
Published: February 2004

A series of 16 different 3‐acyloxy methyl ketones, the acyloin acetates and butyrates (±)‐5, was synthesised by a straightforward new method through alkylation of tert‐butyl 2‐acyloxyacetoacetates 3, followed by chemoselective dealkoxycarbonylation of the tert‐butyloxycarbonyl group in the presence of other ester groups. Subsequent hydrolysis of (±)‐5 can be achieved with base to give racemic acyloins 6, or with lipase catalysis to afford the corresponding non‐racemic acyloins (S)‐6. The remaining (R)‐acyloin esters 5 can be racemised and resubjected to the procedure, or hydrolysed chemically. The kinetic resolution with two of the six tested enzymes, CAL‐B and BCL (PS) lipase, proceeded selectively [enantiomeric ratio (E) values between 50 and > 200] and most of the acyloins (S)‐6 were obtained in very high enantiomeric excesses (up to > 99% ee). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Deprotonation of Indole Derivatives in Aqueous Cationic Surfactants
Authors: Spreti Nicoletta , Brinchi Lucia , Di Profio Pietro , Germani Raimondo , Savelli Gianfranco , Bunton Clifford A.
Published: February 2004

Deprotonations of 5‐nitroindole, 1a, and its 2‐carboxylate ion, 2a, have been monitored in 0.01, 0.1, and 0.5 M NaOH in micellar solutions of cetyl trialkylammonium bromide, alkyl = Me, Et, nPr, nBu, CTABr, CTEABr, CTPABr, CTBABr. Extents of deprotonation (% f) have been fitted using the pseudophase model of micellar effects with interionic competition described by ion exchange or by independent association constants. Both treatments indicate that base dissociation constants in dilute OH− are lower than in water by factors of ca. 3−11, and decrease with increasing bulk of the head groups, and that these factors increase modestly as the OH− concentration increases to 0.5 M. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis of (±)‐17‐Methylcamptothecins
Authors: Thomas Olivier P. , Dumas Cécile , Zaparucha Anne , Husson Henri‐Philippe
Published: February 2004

(±)‐17‐Methylcamptothecins (29) were synthesized from the heteroyohimbane ajmalicine (5) through sequential oxidation steps and E‐ring functionalization. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Suzuki Cross‐Coupling Reactions between Alkenylboronic Acids and Aryl Bromides Catalysed by a Tetraphosphane‐Palladium Catalyst
Authors: Peyroux Eugénie , Berthiol Florian , Doucet Henri , Santelli Maurice
Published: February 2004

A range of alkenylboronic acids undergo Suzuki cross‐coupling with aryl bromides in good yields in the presence of [PdCl(C3H5)]2/cis,cis,cis‐1,2,3,4‐tetrakis[(diphenylphosphanyl)methyl]cyclopentane as a catalyst. A wide variety of 1‐arylprop‐1‐enes, 2‐arylprop‐1‐enes, 2‐arylbut‐1‐enes and 1,1‐diarylethylene or styrene derivatives have been prepared. Moreover, the reaction tolerates several functions, such as acetyl, formyl, nitrile or nitro. Furthermore, this catalyst can be used at low loading, even for reactions of sterically hindered substrates. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
The Structural Proliferation of 2,6‐Difluoropyridine through Organometallic Intermediates
Authors: Schlosser Manfred , Rausis Thierry
Published: February 2004

Contrary to a literature claim, 2,6‐difluoropyridine‐3‐carboxaldehyde can be readily prepared by consecutive treatment of 2,6‐difluoropyridine with lithium diisopropylamide and N,N‐dimethylformamide. Regioselective displacements of fluorine from the aldehyde by nucleophiles were carried out. To demonstrate the versatility of the organometallic approach, some two dozens of further 2,6‐difluoropyridine derivatives were prepared applying a combination of modern organometallic methods such as site selective hydrogen/metal and halogen/metal permutations and deprotonation‐triggered heavy halogen migrations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis of the Four Stereoisomers of 6‐Acetoxy‐19‐methylnonacosane, the Most Potent Component of the Female Sex Pheromone of the New World Screwworm Fly, with Special Emphasis on Partial Racemization in the Course of Catalytic Hydrogenation
Authors: Mori Kenji , Ohtaki Takashi , Ohrui Hiroshi , Berkebile Dennis R. , Carlson David A.
Published: February 2004

Starting from the enantiomers of citronellal and 1‐octyn‐3‐ol, all four stereoisomers of 6‐acetoxy‐19‐methylnonacosane were synthesized with sufficiently high stereochemical purities (more than 90% ee at C‐6; about 97% ee at C‐19) for their biological testing as the female sex pheromone of the screwworm fly (Cochliomyia hominivorax). All four isomers showed strong pheromone activity even at 1 μg, and no significant difference was observed in their potency. Adams’ platinum oxide was found to cause partial racemization of enantiomerically pure secondary propargylic alcohols in the course of their catalytic hydrogenation to saturated and secondary alcohols, while palladium‐charcoal was less potent in causing partial racemization. A new HPLC‐based discrimination of chiral and secondary alcohols proved to be useful in following such a subtle partial racemization. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Scope and Limitations of the Peterson Olefination Reaction as a Route to Vinylidene Phosphanes
Authors: Izod Keith , McFarlane William , Tyson Brent V.
Published: February 2004

The Peterson olefination reaction has been investigated as a route to novel P‐substituted alkenes. The reaction between [(nPr2P)2(Me3Si)C]Li and paraformaldehyde cleanly gives the symmetrical vinylidene phosphane (nPr2P)2C=CH2 (4) in good to excellent yields. In contrast, reactions between [(R2P)(Me3Si)2C]Li (R = Me, nPr) and paraformaldehyde yield complex mixtures of products which do not contain the expected vinylidene species. However, the unsymmetrical vinylidene phosphanes [nPr2P(BH3)](Me3Si)C=CH2 (6), (Ph2P)(iPr2P)C=CH2 (7), [nPr2P(S)](Me3Si)C=CH2 (10), [Ph2P(S)][iPr2P(S)]C=CH2 (11) and [Ph2P(S)][Me2P(S)]C=CH2 (12) are readily accessible by the Peterson olefination reaction {compound 7 is obtained by deprotection of the corresponding borane adduct [Ph2P(BH3)][iPr2P(BH3)]C=CH2 with pyrrolidine}. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis of the Unusual Octahydropyrano[2,3‐b]pyridine Ring System of ′Upenamide
Authors: Maia Alessandra Alves , Mons Stéphane , Pereira de Freitas Gil Rossimiriam , Marazano Christian
Published: February 2004

We describe for the first time the preparation of a model octahydropyrano[2,3‐b]pyridine 23 bearing substituents at positions 2 and 8, as in the natural alkaloid ′upenamide. The four inseparable diastereoisomers of 23, present in an 81:3:16:trace ratio, were analyzed by NMR spectroscopy experiments to fully determine their relative configurations and conformations. The major diastereoisomer of this non‐macrocyclic analog has the same configuration as in natural ′upenamide. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
An Electrochemical Flow Analysis System for Putrescine Using Immobilized Putrescine Oxidase and Horseradish Peroxidase
Authors: Saby Coralie , Nguyen Tien V. , Luong John H. T.
Published: February 2004

An electrochemical flow analysis system was optimized together with immobilized putrescine oxidase and horseradish peroxidase for putrescine measurement. Four coupling agents, suberic acid bis(N‐hydroxysuccinimide ester), γ‐maleimidobutyric N‐hydroxysuccinimide ester, 1‐ethyl‐3‐(3‐dimethylaminopropyl)carbodiimide and glutaraldehyde, were used for immobilizing the two enzymes on porous aminopropyl glass beads to form a bienzymic detection column. Although the glutaraldehyde crosslinking procedure offered the highest response, the immobilized bienzyme system was responsive to putrescine, spermidine (123% of the putrescine response at 250 μM) and cadaverine (98% of the putrescine response). In contrast, the enzymes immobilized on the glass beads using suberic acid bis(N‐hydroxysuccinimide ester) offered significantly better selectivity towards putrescine at the same concentration. For comparison, cadaverine and spermidine only provoked a response of 4.7% and 27.5% of the putrescine signal. The response to cadaverine and spermidine was further suppressed by lowering the detection pH from 8 to 7. At 250 μM, the response obtained for cadaverine and spermidine was only 1.5% and 3.9%, respectively, of the signal obtained for putrescine. A linear response to putrescine was obtained from 5 to 75 μM (0.629 μAs μM−1, R2=0.997) with a detection limit of 5 μM (S/N=3). The amperometric response retained 75% of its initial value after 600 repeated injections. The immobilized PUO/HRP (putrescine oxidase/horseradish peroxidase) was successfully demonstrated for measuring putrescine in fish extracts as an indicator of fish spoilage.
Amperometric Determination of Ascorbic Acid at an Electrodeposited Redox Polymer Film Modified Gold Electrode
Authors: Fei Junjie , Luo Liming , Hu Shengshui , Gao Zhiqiang
Published: February 2004

A sensitive and selective electrochemical method for the determination of ascorbic acid was developed. It was shown that a hydrated osmium complex‐containing redox polymer film can be electrodeposited at the gold electrode and it exhibits excellent electrocatalytic activity towards the oxidation of ascorbic acid. In contrast to a bare gold electrode, the oxidation current of ascorbic acid increased greatly and the oxidation peak potential shifted negatively to about 0.01 V (vs. SCE) at the modified electrode. Amperometric measurements were performed at an applied potential of 0.01 V and a linear response was obtained in the range of 2–400 μM with a limit of detection (LOD) of 0.6 μM (S/N=3). The interference studies showed that the modified electrode exhibits excellent selectivity in the presence of large excess of uric acid and dopamine. The proposed procedure was successfully applied to the determination of ascorbic acid in human urine samples.
Myoglobin‐Clay Electrode for Nitric Oxide (NO) Detection in Solution
Authors: Kröning Steffen , Scheller Frieder W. , Wollenberger Ulla , Lisdat Fred
Published: February 2004

Sodium montmorillonite was prepared via a colloidal chemical approach and deposited onto glassy carbon electrodes (GCE). Myoglobin was immobilized on the clay membrane modified electrode by spontaneous adsorption. Characterization of the myoglobin/clay/glassy carbon electrode (Mb/clay/GCE) showed a quasi‐reversible, electrochemical redox behavior of the adsorbed protein with a formal potential of −0.380±0.010 V (vs. Ag/AgCl). The heterogeneous electron transfer rate constant was found to be strongly influenced by the buffer concentration. The Mb/clay/GCE was stable for several days in solution. The interaction of the immobilized Mb with nitric oxide (NO) is characterized by coordination chemistry. The reaction was found to be reversible and could be applied for NO detection in the nanomolar concentration range by a voltammetric analysis. In addition a mixed protein electrode with co‐immmobilized myoglobin (Mb) and cytochrome c (Cyt.c) was developed. By choice of the electrode potential both proteins can be addressed independently.
Calix[4]resorcinarenetetrathiol Modified Gold Electrodes: Applications to the Adsorption and Electrochemical Determination of N‐Nitrosamines
Authors: Collyer Stuart D. , Bradbury Sally , Davis Frank , Hatfield John V. , Stirling Charles J. M. , Higson Séamus P. J.
Published: February 2004

Preliminary results reported in this paper relate to the capture, retention and subsequent analysis of cationic N‐nitrosamines, from aqueous solutions, at calix[4]resorcinarenetetrathiol modified gold electrodes. Adsorptive stripping voltammetric regimes at electrodes of this type have allowed quantifications of N‐nitroso‐N‐butyl‐N‐propylamine down to concentrations of 10−10 M. Calix coatings have been shown, in certain cases, to allow an enhancement in the adsorptive uptake and subsequent analysis of N‐nitrosamines in solution in comparison to signals obtained at bare gold electrodes, although the coatings may become saturated when higher concentrations or when longer preaccumulative deposition times are employed.
Electrooxidation and Amperometric Detection of Ascorbic Acid at GC Electrode Modified by Electropolymerization of N,N‐Dimethylaniline
Authors: Roy Protiva Rani , Saha Madhu Sudan , Okajima Takeyoshi , Ohsaka Takeo
Published: February 2004

The polymer film of N,N‐dimethylaniline (DMA) is deposited on the electrochemically pretreated glassy carbon (GC) electrode by continuous electrooxidation of the monomer. This poly N,N‐dimethylaniline (PDMA) film‐coated electrode can be used as an amperometric sensor of ascorbic acid (AA). The polymer film (thickness (ϕ): 0.3±0.02 μm) having positive charge in its backbone attracts the anionic species AA. Thus, the anodic peak potential (350 mV vs. Ag|AgCl|NaCl(sat)) for the oxidation of AA at the bare electrode is largely shifted to the negative value (150 mV) at this electrode. The PDMA film‐coated electrode is stable in acidic, alkaline and neutral media and can sense AA at different pH's. The diffusion coefficients of AA in solution (D) and in film (Ds) were estimated by rotating disk electrode voltammetry: D=(5.5±0.1)×10−6 cm2 s−1 and Ds=(6.3±0.2)×10−8, (6.0±0.2)×10−8 and (4.7±0.2)×10−8 cm2 s−1 for 0.5, 1.5 and 3.0 mM AA, respectively. A permeability of AA through the PDMA film was found to decrease with increasing the concentration of AA in the solution. In the chronoamperometry, the current response for the oxidation of AA at different times elapsed after potential‐step application is linearly increased with the increase in AA concentration in a wide range of its concentration from 25 μM to 1.65 mM. In the hydrodynamic amperometry, a successive addition of 10 μM AA caused the successive increase in current response with equal amplitude and the sensitivity was calculated as 0.178 μA cm−2 μM−1. So, the fouling of the electrode surface caused by the oxidized product of AA is markedly eliminated at this PDMA film‐coated electrode. A flow injection analysis based on the present electrode was performed to estimate the concentration of vitamin C in fruit juice.
Burning behaviors of selected chlorosilanes and SiH‐containing siloxanes
Authors: Hshieh Fu‐Yu , Beeson Harold D.
Published: February 2004

Chlorosilanes are silanes containing the Si‐Cl functional group and SiH‐containing siloxanes are siloxanes containing the Si‐H functional group. Some chlorosilanes and SiH‐containing siloxanes present potentially high fire or explosion hazards during handling, storage, transport and process operations. Cone calorimeter tests have been used to study the burning behaviors of selected chlorosilanes and SiH‐containing siloxanes at various incident heat fluxes to simulate pool fire burning. The peak heat release rate of a silicon intermediate obtained from the cone calorimeter at 15 kW/m2 incident heat flux was very close to that measured by a relatively large‐scale field test. The flammability of monochlorosilanes was similar to that of organic hydrocarbons having comparable volatility. The flammability of chlorosilanes descends in the order of monochlorosilanes, dichlorosilanes and trichlorosilanes. SiH‐containing siloxanes ignited faster than non‐SiH‐containing siloxanes because of the reactive silicon‐hydrogen linkages. The ignition of SiH‐containing siloxanes was much more violent than the ignition of non‐SiH‐containing siloxanes. The SiH‐containing siloxanes exhibited a lower peak heat release rate, less total heat released and a lower peak smoke extinction coefficient compared with non‐SiH‐containing siloxanes having comparable volatility. Copyright © 2004 John Wiley & Sons, Ltd.