bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clustering of C‐Type Lectin Natural Killer Receptor‐Like Loci in the Bony Fish Oreochromis niloticus
Authors: Kikuno R. , Sato A. , Mayer W. E. , Shintani S. , Aoki T. , Klein J. 
Published: February 2004

AbstractThe genome of the cichlid (teleost) fish Oreochromis niloticus contains a set of genes which encode group V C‐type lectin proteins homologous to the mammalian NKG2/CD94 family of natural killer (NK) cell receptors. To determine the genomic organization of these killer cell‐like receptor (KLR) genes, an O. niloticus BAC library was screened with a cDNA probe derived previously from an expressed sequence tag of the related cichlid species Paralabidochromis chilotes. Four distinct KLR‐bearing BAC clones were analysed, three of which could be assembled into a contig. One of the clones was sequenced in its entirety, whereas the others were partially sequenced to identify the KLR loci borne by them. Altogether, 28 distinct KLR loci were identified, of which at least 26 occupy a single chromosomal region, the KLR complex. One half of the loci appear to be occupied by pseudogenes. Compared to the human NK cell receptor complex, the Oreochromis KLR complex is more compact and, apart from transposons, appears to contain only KLR loci. The gene density of the complex is one KLR locus per 18 kb of sequence. All the KLR loci constituting the complex are derived from a single most recent common ancestor, which is estimated to have existed 7.7 million years ago. The 180 kb of the determined sequence is a mosaic of blocks of similar segments reflecting a complex history of duplications, deletions and rearrangements. The transposons found in the sequenced part belong to the TC1, Xena, CR1 and TX1 families.
Proteasomal Targeting and Minigene Repetition Improve Cell‐Surface Presentation of a Transfected, Modified Melanoma Tumour Antigen
Authors: Rasmussen A. B. , Zocca M.‐B. , Bonefeld C. M. , Von Essen M. , Lauritsen J. P. H. , Tomra S. , Ødum N. , Geisler C. 
Published: February 2004

AbstractMelanoma antigen recognized by T cell 1 (MART‐1) is regarded as a candidate peptide for vaccination against malignant melanoma, and it is of importance to develop strategies to improve the vaccine‐elicited T‐cell activation towards MART‐1. T‐cell activation is, among other determinants, dependent on the density of specific major histocompatibility complex–peptide complexes on the surface of the antigen‐presenting cell. In this study, we explored the cell‐surface presentation of a substituted MART‐1 peptide encoded by transfected minigenes. We investigated the potential of proteasomal targeting compared to non‐proteasomal targeting of the epitope to increase its cell‐surface presentation. Furthermore, we explored the potential of incorporating multiple minigenes instead of one to increase cell‐surface presentation. We show that both proteasomal targeting and repetition of the minigene increase cell‐surface presentation of the epitope and propose both these approaches as potential strategies in DNA vaccines to increase MART‐1‐specific T‐cell activation.
Proliferative and Cytotoxic Response of Human Natural Killer Cells Exposed to Transporter Associated with Antigen‐Processing‐Deficient Cells
Authors: Cerboni C. , Öberg L. , Terrazzano G. , Zappacosta S. , Carbone E. , Kärre K. 
Published: February 2004

AbstractIn transporter associated with antigen‐processing (TAP)‐deficient patients affected by a severe downmodulation of human leucocyte antigen class I (HLA‐I) molecules, natural killer (NK) cells have an increased expression of the inhibitory receptor CD94/NKG2A. Focusing our attention on NK cells, we have investigated the phenotype, function and proliferative response of peripheral blood lymphocytes (PBLs) derived from healthy donors after coculturing with TAP (T2)‐ or HLA‐I‐deficient (721.221) cell lines and their related HLA‐I‐expressing transfectants (T3 and DT360, respectively). After 4 days, NK cells cocultured with T2 cells had a threefold increased CD94 expression compared to NK cells cocultured with T3. This increase was due to proliferation of the CD56brightCD94bright subset. In contrast, expression of other inhibitory receptors [killer cell immunoglobulin (Ig)‐like receptors] was variable during time and was not related to HLA‐I molecules expressed by stimulating cells. Similar results were obtained using HLA‐I‐deficient cells (721.221). The PBLs cocultured for 4 days with T2 cells displayed enhanced cytotoxic responses. The results suggest that CD56brightCD94bright NK cells are induced to proliferate and kill in response to a TAP‐deficient environment. The changes seen in the NK‐cell compartment were partially contributed by T lymphocytes present in the coculture. These data could explain the increased CD94 expression and autoimmune manifestations observed in TAP‐deficient patients.
Immunoglobulin Levels Amongst Persons with and without Human Immunodeficiency Virus Type 1 Infection in Uganda and Norway
Authors: Lugada E. S. , Mermin J. , Asjo B. , Kaharuza F. , Downing R. , Langeland N. , Ormaasen V. , Bruun J. , Awor A. C. , Ulvestad E. 
Published: February 2004

AbstractCD4+‐cell count and viral load monitoring are expensive and unavailable to most human immunodeficiency virus (HIV)‐infected people in Africa. In an attempt to evaluate alternative methods for monitoring antiretroviral (ARV) therapy, we measured concentrations of immunoglobulin (Ig)A, IgM, IgG and IgG1 amongst adults with and without HIV in Uganda and Norway. We adjusted for disease severity by stratifying HIV‐positive subjects on CD4+‐cell counts above and below 200 cells/µl. Median serum levels of IgG, IgG1 and IgA were significantly higher in HIV‐positive persons compared with HIV‐negative persons in both countries (P < 0.001 and P = 0.018 for IgA in Ugandan patients). Levels of IgA in Ugandan HIV‐negative subjects were significantly lower than those in HIV‐positive subjects with low CD4+ compared with those with high CD4+‐cell counts (P < 0.001 and P = 0.069, respectively). IgM levels were different between the HIV‐negative and the two HIV‐positive groups in Norway (P < 0.001). The mean levels of IgM, IgG and IgG1 in HIV‐negative and ‐positive African subjects were generally higher than those in comparable groups of Western subjects. Our results verify that levels of IgA, IgG and IgG1 vary between HIV‐negative and ‐positive individuals in both study populations. Their determination may be useful in monitoring both disease progression and response to ARV therapy.
Indoleamine 2,3‐Dioxygenase is Necessary for Cytolytic Activity of Natural Killer Cells
Authors: Kai S. , Goto S. , Tahara K. , Sasaki A. , Tone S. , Kitano S. 
Published: February 2004

AbstractIndoleamine 2,3‐dioxygenase (IDO) is a tryptophan catabolic enzyme that is widely distributed in various tissues. In peripheral blood mononuclear cells (PBMCs), production of IDO by macrophages or dendritic cells has been reported to inhibit T‐cell activation and proliferation. In the present study, we have determined that other phenotypes of PBMCs also express IDO. In cultures of PBMCs, IDO was found predominantly in monocyte by immunohistochemistry. Reverse transcriptase polymerase chain reaction analysis showed that IDO mRNA was expressed in T lymphocytes, B lymphocytes and natural killer (NK) cells and that expression was increased upon activation with interferon‐γ. The cytotoxicity of NK cells against K562 and HepG2 cells was reduced by IDO inhibitor. These results suggest that IDO in NK cells is essential for NK cells to generate killing activity against cancer cells.
In Vitro Study of the Long‐Term Effects of Post‐Traumatic Splenectomy on Cellular Immunity
Authors: Karakantza M. , Theodorou G. L. , Mouzaki A. , Theodori E. , Vagianos C. , Maniatis A. 
Published: February 2004

AbstractThe purpose of this study was to investigate the effect of splenectomy on cellular immunity. We studied the cellular phenotype and type 1 [interferon‐γ, interleukin‐2 (IL‐2)] and type 2 (IL‐4 and IL‐10) cytokine‐producing peripheral blood CD4+ and CD8+ T lymphocytes in 22 healthy adults who had undergone post‐traumatic splenectomy about 1 to 35 years ago. Splenectomy resulted in a long‐term reduction of the percentage of CD4+CD45RA+ cells and a late increase of the percentage and absolute numbers of T‐cell receptor γ/δ cells. Stimulation with Staphylococcal enterotoxin B resulted in normal IL‐2 production by CD4+ T cells, indicating that the naïve cells were not anergic. Splenectomy also resulted in long‐term priming of both CD4+ and CD8+ T cells. During the first 8 years, both type 1 and type 2 CD4+ T cells were primed to varying degrees. About 8 years later, the percentage of primed type 2 CD4+ T cells subsided, but that of type 1 CD4+ T cells, although decreased, remained detectable over a longer period. Priming of CD8+ T cells persisted throughout the study period. The long‐term priming of type 1 CD4+ and CD8+ T cells, which may result in partial impairment of T‐cell functions, may explain reported defects of immune responses to recall antigens in splenectomized individuals. In addition, changes in the profile of primed CD4+ T cells with time may be clinically relevant to relapses in autoimmune thrombocytopenia after splenectomy.
Immunodominant B‐Cell Epitope in the Mce1A Mammalian Cell Entry Protein of Mycobacterium tuberculosis Cross‐Reacting with Glutathione S‐Transferase
Authors: Harboe M. , Das A. K. , Mitra D. , Ulvund G. , Ahmad S. , Harkness R. E. , Das D. , Mustafa A. S. , Wiker H. G. 
Published: February 2004

AbstractThe TB1‐5 76C monoclonal antibody raised against a synthetic 60‐mer peptide in the N‐terminal part of the Mce1A mammalian cell entry protein of Mycobacterium tuberculosis has previously been shown to react with a linear epitope in the KRRITPKD region, residues 131–138 in Mce1A, and to cross‐react with Mce1F. Six additional monoclonal antibodies raised against the same peptide were also shown to cross‐react with Mce1F. Four of them reacted with a linear epitope in the same area, indicating that this area is immunodominant but showed distinct differrences in fine specificity. Two monoclonal antibodies did not react with synthetic peptides from this region on the solid phase in enzyme‐linked immunosorbent assay, indicating greater influence of conformation on reactivity. None of the monoclonal antibodies reacted with 14‐mer synthetic peptides from the corresponding area in Mce2A, Mce3A, Mce4A, M. avium, M. smegmatis or M. leprae. The reaction pattern of the monoclonal antibodies was analysed in relation to our model of the Mce1A molecule (AK Das et al. Biochem Biophys Res Commun 2003;302:442–7).The epitope is located on the surface of Mce1A, at the distal β‐strand‐loop region in the β‐domain supporting its potential role in promoting uptake of M. tuberculosis in host cells. Monoclonal antibody TB1‐5 19C cross‐reacted with glutathione S‐transferase of Schistosoma japonicum containing a PKE triplet. Monoclonal antibody TB1‐5 76C gave a major band at about 44 kDa in Western blotting of M. tuberculosis sonicate, whereas polyclonal rabbit anti‐Mce1A peptide antibodies reacting with the extended TTPKNPTKRRITPKDVI area of Mce1A showed a distinct band above the 160 kDa molecular mass standard.
Plaque development in relation to the periodontal condition and bacterial load of the saliva
Authors: Rowshani B. , Timmerman M. F. , Van der velden U. 
Published: February 2004

AbstractAim: To investigate the influence of the oral bacterial load on plaque development in various groups of periodontitis patients and in healthy subjects.Material and Methods: This study included subjects with a healthy periodontium, a healthy reduced periodontium after treatment, an inflamed reduced periodontium after treatment and untreated periodontitis. At the start of the study, subjects were instructed to rinse with 10 ml reduced transport fluid (RTF) for 10 s in order to evaluate the oral bacterial load. The microbiological evaluation included anaerobe culture and phase‐contrast microscopy. Next, the amount of plaque and the clinical condition were evaluated. Thereafter, all supragingival plaque was removed and patients were instructed to refrain from all oral hygiene procedures for 19 h. Subsequently, the rinsing procedure and the evaluation of the amount of plaque were repeated.Results: The amount of plaque that developed in 19 h was significantly higher in the untreated periodontitis group as compared with the two healthy groups. In case of an inflamed reduced periodontium, sites with deep pockets developed more plaque in 19 h than sites with shallow pockets. The number of bacteria present in the rinsing samples of the two inflamed groups was considerably higher than of the two periodontally healthy groups. A significant correlation was found between the bleeding index at intake and the plaque index at 19 h. No correlations were found between gingival recession and the bacterial counts at intake, and the plaque index at 19 h.Conclusion: The present findings support the concept that the periodontal condition is the dominating factor in relation to the rate of plaque formation. The number of bacteria present in the oral cavity as ascertained by means of a rinsing sample does not seem to play a role.
Patient‐based assessments of clinical periodontal conditions in relation to alveolar bone loss
Authors: Renvert S. , Persson G. R. 
Published: February 2004

AbstractBackground: Limited subject‐based information exists on the relationship between clinical and radiographic periodontal data.Aims: To use subject‐based data to assess the extent of concurrence between clinical and radiographic information, and to study what clinical information best predicts alveolar bone loss (ABL).Material and Methods: Subject‐based data on smoking habits, bleeding on probing, plaque scores, pocket probing depth (PD), and evidence of alveolar BL were obtained, and functional periodontal pentagon risk diagrams (PPRDs) were studied from 168 consecutive subjects attending a medical clinic.Results: The mean age of the subjects was 62.7 years (SD±9.0). The average number of teeth was 21.3 (SD±8.0) with on average 5.6 molars remaining (SD± 3.9). In this subject cohort, 33.1% had never smoked, 44.2% had quit smoking, and 22.7% were currently smokers. Mean plaque and bleeding scores were high or 60.2% (SD±24.0) and 53.1% (SD±23.6), respectively. PDs 6.0 mm were found in 55.9% of the subjects. Binary logistic regression analysis demonstrated that tooth loss and proportional plaque scores were the predominant factors included in the equations associated with ABL. Wald coefficients varied between 3.99 and 9.15, and with p‐values between 0.05 and 0.01. When included, the PPRD score became the exclusive factor at several cut‐off levels (Wald's coefficients between 19.8 and 15.6, p<0.001). Consequently, the best receiver operator curve was identified for the PPRD at the >40% cut‐off ABL level (area under the curve: 0.81; 95% CI: 0.74–0.89; p<0.001).Conclusions: The number of teeth lost and the proportion of plaque scores provided significant predictive factors for ABL. The functional PPRD demonstrated an exclusive and highly predictable association with ABL. Subject‐based proportional data for PDs >4.0 mm provided poor substitute measures for the extent of ABL.
Influence of a SLS‐containing dentifrice on the anti‐plaque efficacy of a chlorhexidine mouthrinse
Authors: Van Strydonck D. A. C. , Scalé S. , Timmerman M. F. , Van der Velden U. , Van der Weijden G. A. 
Published: February 2004

AbstractBackground: Chlorhexidine (CHX) and sodium lauryl sulphate (SLS), the most widely used detergent in dentifrice, may counteract. Consequently, studies about this interaction suggested that care is required when combining both these compounds, even when they are introduced separately into the oral cavity. The purpose of the present study was to investigate the effect of toothbrushing with a SLS‐containing dentifrice in one jaw, on the plaque inhibition of a CHX mouthrinse in the opposite jaw during a 4‐day study period.Methods: The study was an examiner‐blind, randomised two‐cell, crossover design.It used a 4‐day plaque accumulation model to compare two different oral hygiene regimens with a washout period of 17 days. Sixteen healthy volunteers were enrolled in the study and received a thorough dental prophylaxis at the beginning of each 4‐day test period. One jaw (upper or lower) was randomly assigned as the “study” jaw. The opposite jaw was assigned as the “dentifrice” jaw and served only to introduce the effect of brushing with a dentifrice in the study model. Two oral hygiene regimens were evaluated. During one randomly assigned test period, the “dentifrice” jaw was treated by toothbrushing with a 1.5% SLS‐containing dentifrice and rinsed together with the “study” jaw with 0.2% CHX, thus forming regimen 1. As a control during the other test period, both the “dentifrice” jaw and “study” jaw were only rinsed with 0.2% CHX, forming regimen 2. No other oral hygiene methods were allowed. After 4 days of undisturbed plaque accumulation, the amount of plaque was evaluated (Silness & Löe 1964). The “study” jaw was used to study the effect of the two regimens on the level of plaque accumulation at the end of the 4‐day period.Results: The overall plaque index was 0.36 for regimen 1 and 0.34 for regimen 2. There was no significant difference in plaque accumulation between the two regimens.Conclusions: Within the limitations of the present study design, it can be concluded that ordinary brushing with a 1.5% SLS‐containing dentifrice (Colgate Bi‐Fluor), followed by rinsing with water does not appear to reduce the level of plaque inhibition offered by a post‐brushing CHX rinse.
A wheat gene encoding an aluminum‐activated malate transporter
Authors: Sasaki Takayuki , Yamamoto Yoko , Ezaki Bunichi , Katsuhara Maki , Ahn Sung Ju , Ryan Peter R. , Delhaize Emmanuel , Matsumoto Hideaki 
Published: February 2004

SummaryThe major constraint to plant growth in acid soils is the presence of toxic aluminum (Al) cations, which inhibit root elongation. The enhanced Al tolerance exhibited by some cultivars of wheat is associated with the Al‐dependent efflux of malate from root apices. Malate forms a stable complex with Al that is harmless to plants and, therefore, this efflux of malate forms the basis of a hypothesis to explain Al tolerance in wheat. Here, we report on the cloning of a wheat gene, ALMT1 (aluminum‐activated malate transporter), that co‐segregates with Al tolerance in F2 and F3 populations derived from crosses between near‐isogenic wheat lines that differ in Al tolerance. The ALMT1 gene encodes a membrane protein, which is constitutively expressed in the root apices of the Al‐tolerant line at greater levels than in the near‐isogenic but Al‐sensitive line. Heterologous expression of ALMT1 in Xenopus oocytes, rice and cultured tobacco cells conferred an Al‐activated malate efflux. Additionally, ALMT1 increased the tolerance of tobacco cells to Al treatment. These findings demonstrate that ALMT1 encodes an Al‐activated malate transporter that is capable of conferring Al tolerance to plant cells.
Overexpression of LSH1, a member of an uncharacterised gene family, causes enhanced light regulation of seedling development
Authors: Zhao Li , Nakazawa Miki , Takase Tomoyuki , Manabe Katsushi , Kobayashi Masatomo , Seki Motoaki , Shinozaki Kazuo , Matsui Minami 
Published: February 2004

SummaryLight regulates plant growth and development through a network of endogenous factors. By screening Arabidopsis activation‐tagged lines, we isolated a dominant mutant (light‐dependent short hypocotyls 1‐D (lsh1‐D)) that showed hypersensitive responses to continuous red (cR), far‐red (cFR) and blue (cB) light and cloned the corresponding gene, LSH1. LSH1 encodes a nuclear protein of a novel gene family that has homologues in Arabidopsis and rice. The effects of the lsh1‐D mutation were tested in a series of photoreceptor mutant backgrounds. The hypersensitivity to cFR and cB light conferred by lsh1‐D was abolished in a phyA null background (phyA‐201), and the hypersensitivity to cR and cFR light conferred by lsh1‐D was much reduced in the phytochrome‐chromophore synthetic mutant, hy1‐1 (long hypocotyl 1). These results indicate that LSH1 is functionally dependent on phytochrome to mediate light regulation of seedling development.
ArabidopsisµA‐adaptin interacts with the tyrosine motif of the vacuolar sorting receptor VSR‐PS1
Authors: Happel Nicole , Höning Stefan , Neuhaus Jean‐Marc , Paris Nadine , Robinson David G. , Holstein Susanne E. H. 
Published: February 2004

SummaryIn receptor‐mediated transport pathways in mammalian cells, clathrin‐coated vesicle (CCV) µ‐adaptins are the main binding partners for the tyrosine sorting/internalization motif (YXXØ). We have analyzed the function of the µA‐adaptin, one of the five µ‐adaptins from Arabidopsis thaliana, by pull‐down assays and plasmon resonance measurements using its receptor‐binding domain (RBD) fused to a histidine tag. We show that this adaptin is able to bind the consensus tyrosine motif YXXØ from the pea vacuolar sorting receptor (VSR)‐PS1, as well as from the mammalian trans‐Golgi network (TGN)38 protein. Moreover, the tyrosine residue was revealed to be crucial for binding of the complete cytoplasmic tail of VSR‐PS1 to the plant µA‐adaptin. The trans‐Golgi localization of the µA‐adaptin strongly suggests its involvement in Golgi‐ to vacuole‐trafficking events.
dwarf and delayed‐flowering 1, a novel Arabidopsis mutant deficient in gibberellin biosynthesis because of overexpression of a putative AP2 transcription factor
Authors: Magome Hiroshi , Yamaguchi Shinjiro , Hanada Atsushi , Kamiya Yuji , Oda Kenji 
Published: February 2004

SummaryA novel gibberellin (GA)‐deficient mutant designated dwarf and delayed‐flowering 1 (ddf1) was isolated from a library of activation‐tagged Arabidopsis. This mutant showed dwarfism and late‐flowering, but the phenotype was rescued by exogenous GA3 like known mutants defective in GA biosynthesis. The contents of bioactive GA4 and GA1 were in fact decreased in ddf1 at least partially through the repression of biosynthetic steps catalyzed by GA 20‐oxidase (GA20ox). Genetic and molecular analyses revealed that the ddf1 phenotypes are caused by increased or ectopic expression of a putative AP2 transcription factor. Overexpression of DDF2, encoding another putative AP2 transcription factor closely related to DDF1, also conferred the ddf1‐like phenotype. Among genes encoding (putative) AP2 transcription factors in Arabidopsis, DDFs are phylogenetically close to dehydration‐responsive element binding protein (DREB1)/C‐repeat binding factor (CBF) genes, which are known to be involved in stress responses. The ddf1 mutation upregulates a stress‐related gene RD29A. DDF1 mRNA is strongly induced by high‐salinity stress within 1 h. Moreover, transgenic plants overexpressing DDF1 showed increased tolerance to high‐salinity stress. These results suggest that DDF1 is involved in the regulation of GA biosynthesis and stress tolerance. The possible relation between the contents of endogenous GAs and acquisition of stress protection is discussed.