bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Anti‐Neutrophil Cytoplasm Autoantibodies on Tissue Factor Activity by HL‐60 Cells In Vitro
Authors: Flores‐Suárez L. F. , Nowack R. , Yard B. A. , Dempfle C.‐E. , Van Der Woude F. J. 
Published: March 2003

AbstractThe effects of cytoplasmic anti‐neutrophil cytoplasm autoantibodies (C‐ANCA) and perinuclear ANCA (P‐ANCA) immunoglobulin G (IgG) on tissue factor (TF) activity using HL‐60 cells in vitro were compared with those of medium, lipopolysaccharide (LPS) and control IgG. Cells were also incubated with both ANCA IgG and control IgG in the presence of a submaximal concentration of LPS capable of upregulating TF procoagulant activity (TF‐PCA) measured in arbitrary units of TF equivalent (AU‐TFEq). The purpose was to search for an additive effect between LPS and ANCA IgG. All IgG preparations increased HL‐60 cell TF‐PCA in comparison with the medium. When cells were incubated with P‐ANCA IgG and LPS (1 µg/ml), a larger increase was seen (151.23 ± 31.6 SEM (standard error of the mean) AU‐TFEq) than when incubated with control IgG plus LPS (91.01 ± 18.4 SEM AU‐TFEq; P < 0.005), P‐ANCA IgG alone (73.68 ± 12.7 SEM AU‐TFEq; P < 0.005) or LPS (1 µg/ml) (58.11 ± 7.9 SEM AU‐TFEq; P < 0.005). There was concordance between PCA and TF total antigen content by enzyme‐linked immunosorbent assay (ELISA). The fact that P‐ANCA IgGs upregulate the function of TF in HL‐60 cells in combination with LPS adds to information regarding the possible role of ANCAs in the enhancement of TF by different cells, although it does not support the fact that ANCAs alone play a role in mononuclear cell TF upregulation. The additive effects of LPS underline the possible role of pro‐inflammatory stimuli in the pathogenesis of ANCA‐associated diseases.
Cytokine Production and Expression of Leucocyte‐Differentiation Antigens by Human Mononuclear Cells in Response to Mycobacterium tuberculosis Antigens
Authors: Cubillas‐Tejeda A. C. , Ruiz‐Argüelles A. , Bernal‐Fernández G. , Quiroz‐Compeán L. , López‐Dávila A. , Reynaga‐Hernández E. , González‐Amaro R. 
Published: March 2003

AbstractThe aim of this work was to characterize a leucocyte‐differentiation antigen or chemokine receptor that allows the identification of type 1 (T helper 1 (Th1), Tc1) and type 2 (Th2, Tc2) lymphocytes in short‐term‐cultured human peripheral blood mononuclear cells. In addition, we assessed the type of response induced by mycobacterial antigens in tuberculosis patients and healthy contacts. Cells were stimulated with an unfractionated culture filtrate or 30 kDa antigen from Mycobacterium tuberculosis. Then, CD4 and CD8 cell labelling was combined with CD30, CD27, CD28, CD45RA or CD45R0 staining, detection of intracellular interferon‐γ (IFN‐γ) or interleukin‐4 (IL‐4) and analysis by three‐colour flow cytometry. In separate experiments, the expression of different chemokine receptors (CCR1, CCR3, CCR5, CXCR3 and CXCR4) was also studied. We found that none of the cell‐surface molecules studied was preferentially expressed by Th1 or Th2 cells. Thus, our results indicate that these lymphocyte subsets cannot be identified in short‐term‐cultured mononuclear cells on the basis of preferential expression of the cell markers studied, and that it is necessary to look for additional molecules that allow the discrimination of Th1 and Th2 cells.
Human Th1 Cell Lines Recognize the Mycobacterium tuberculosis ESAT‐6 Antigen and its Peptides in Association with Frequently Expressed HLA Class II Molecules
Authors: Mustafa A. S. , Shaban F. A. , Al‐Attiyah R. , Abal A. T. , El‐Shamy A. M. , Andersen P. , Oftung F. 
Published: March 2003

AbstractWe have used a synthetic‐peptide approach to map epitope regions of the Mycobacterium tuberculosis ESAT‐6 antigen recognized by human T cells in relation to major histocompatibility complex (MHC) restriction. ESAT‐6‐specific CD4+ T‐cell lines were established by stimulating peripheral blood mononuclear cells from 25 HLA‐DR‐typed tuberculosis patients with complete antigen in vitro. The established T‐cell lines were then screened for proliferation and interferon‐γ (IFN‐γ) secretion in response to eight overlapping 20‐mer peptides covering the ESAT‐6 sequence. The response of the T‐cell lines to ESAT‐6 and peptides from a human leucocyte antigen (HLA)‐heterogeneous group of donors suggested the presence of multiple epitopes and promiscuous recognition of the antigen. Analysis of antigen and peptide recognition in the presence of anti‐HLA class I and class II antibodies suggested that the T‐cell lines recognized ESAT‐6 in association with HLA‐DR and ‐DQ molecules. Furthermore, testing of selected T‐cell lines with ESAT‐6 and the peptides in the presence of autologous and allogeneic HLA‐DR‐ and ‐DQ‐typed antigen‐presenting cells identified HLA‐DR2, ‐DR52 and ‐DQ2 amongst the HLA molecules involved in the presentation of ESAT‐6 and its peptides to human Th1 cells. In addition, the T‐cell lines were cytotoxic for monocytes and macrophages pulsed with ESAT‐6 and peptides. In conclusion, the recognition of ESAT‐6 by IFN‐γ‐secreting and cytotoxic CD4+ T cells in association with frequently expressed HLA class II molecules supports the application of this antigen to either specific diagnosis or subunit vaccine design.
Antineutrophil Cytoplasmic Antibodies Induce Decreased CD62L Expression and Enhanced Metabolic Activity in Monocytes
Authors: Wikman A. , Fagergren A. , Forslid J. , Jacobson S. H. , Johansson S. G. O. , Lundahl J. 
Published: March 2003

AbstractMonocyte in vitro activation by antimyeloperoxidase (anti‐MPO)‐ and antiproteinase‐3 (anti‐PR3)‐positive sera, corresponding immunoglobulin G (IgG) fractions and monoclonal antibodies against MPO and PR3 was evaluated. The expression of adhesion molecules, l‐selectin (CD62L) and CR3 (CD11b), involved in leucocyte endothelial adhesion, and metabolic activity, measured as the production of hydrogen peroxide, were analysed. Decreased expression of CD62L was demonstrated in monocytes after incubation with antineutrophil cytoplasmic antibody (ANCA)‐positive sera. This finding was not accompanied by changes in CD11b expression. Metabolic activity was increased in monocytes after incubation with ANCA‐positive IgG fractions as well as after incubation with monoclonal anti‐MPO and anti‐PR3. These findings support the concept that the pathophysiological effect of ANCA is partly mediated through the action on crucial events in monocyte activation, such as CD62L downregulation and oxygen radical production.
Fracturing and fluid migration during Palaeogene compression and Neogene extension in the Catalan Coastal Ranges, Spain
Authors: TRAVÉ A. , CALVET F. , SOLER A. , LABAUME P. 
Published: March 2003

The Catalan Coastal Ranges (NE part of the Eastern Iberian Margin) correspond to a system of grabens formed at the north‐western margin of the Valencia Trough. Extensional activity in the Catalan Coastal Ranges occurred at least from early to late Miocene and reactivated earlier transpressive faults related to the Palaeogene compression. In the central part of the Catalan Coastal Ranges, tectonic micro and macrostructures (faults, joints, stylolites) are well developed in the Mesozoic (mainly Cretaceous) limestones as well as in the Miocene graben fill deposits. In these rocks, seven generations of fractures, which formed during different tectonic phases, have been distinguished. Type 1–4 fractures affect only the Cretaceous limestones, type 5 and 6 fractures the Cretaceous and Miocene deposits, and type 7 fractures only the Miocene sediments. The fractures are filled with calcites, and locally with an internal sediment or a dolomite cement. The Cretaceous host‐rock has an average δ18O value of –4·3‰ PDB (Peedee Belemnite), an average δ13C value of +0·6‰ PDB, a 87Sr/86Sr ratio of 0·70741, up to 5630 p.p.m. of Mg2+, up to 2615 p.p.m. of Sr2+, and up to 1560 p.p.m. of Fe2+. Type 2 fractures are related to Palaeogene compression. The calcite cement filling this type of fracture has an average δ18O value of –8·2‰ PDB, an average δ13C value of –0·6‰ PDB, a 87Sr/86Sr ratio of 0·70714, up to 4560 p.p.m. of Mg2+, up to 3275 p.p.m. of Sr2+, and up to 3540 p.p.m. of Fe2+. These results indicate a fluid characterized by a high rock–fluid interaction approaching a closed system equilibrium.Type 5 fractures are related to the syn‐rift stage. The calcite cement filling this type of fracture has an average δ18O value of –6·9‰ PDB, an average δ13C value of –4·3‰ PDB, a 87Sr/86Sr ratio of 0·70787, up to 5375 p.p.m. of Mg2+, up to 1750 p.p.m. of Sr2+ and up to 2855 p.p.m. of Fe2+. These results indicate a fluid characterized by a low rock–fluid interaction and an open hydrogeological system. The cements filling the compressional fractures are characterized by undulose extinction, subgrain formation and deformed mechanical twin planes indicating formation under stressed conditions. In contrast, cements filling extensional fractures are characterized by translucent crystals with uniform extinction, indicating free growth not subjected to stress.
Flow structure of turbidity currents
Authors: Felix M. 
Published: March 2003

AbstractA two‐dimensional numerical model is used to describe the flow structure of turbidity currents in a vertical plane. To test the accuracy of the model, it is applied to historical flows in Bute Inlet and the Grand Banks flow. The two‐dimensional spatial and temporal distributions of velocity and sediment concentration and non‐dimensionalized vertical profiles of velocity, turbulent kinetic energy and sediment concentration are discussed for several simple computational currents. The flows show a clear interaction between velocity, turbulence and sediment distribution. The results of the numerical tests show that flows with fine‐grained sediment have low vertical and high horizontal gradients of velocity and sediment concentration, show little increase in flow thickness and decelerate slowly. Steadiness and uniformity in these flows are comparable for velocity and concentration. In contrast, flows with coarse‐grained sediment have high vertical and low horizontal velocity gradients and high horizontal concentration gradients. These flows grow considerably in thickness and decelerate rapidly. Steadiness and uniformity in flows with coarse‐grained sediment are different for velocity and concentration. The results show the influence of spatial and temporal flow structure on flow duration and sediment transport.
Avulsions, channel evolution and floodplain sedimentation rates of the anastomosing upper Columbia River, British Columbia, Canada
Authors: Makaske Bart , Smith Derald G. , Berendsen Henk J. A. 
Published: March 2003

AbstractAges of channels of the anastomosing upper Columbia River, south‐eastern British Columbia, Canada, were investigated in a cross‐valley transect by 14C dating of subsurface floodplain organic material from beneath levees. The avulsion history within the transect was deduced from these data, and morphological stages in channel development were recognized. Additionally, floodplain sedimentation rates were established. The new data demonstrate that the upper Columbia River is a long‐lived, dynamic anastomosing system. Results show that anastomosis at the study location has persisted since at least 2700 cal. years BP, with avulsions occurring frequently. At least nine channels have formed in the studied cross‐valley transect within the past 3000 years. Channel lifetimes from formation to abandonment appear to be highly variable, ranging from approximately 800 to 3000 years. Log jams provoking avulsions and/or silting up of old channels are proposed as reasons for this variability. Long‐term average floodplain sedimentation rates appear to be significantly lower than previously proposed by Smith (1983, Int. Assoc. Sedimentol. Spec. Publ., 6, 155–168). A long‐term (4550 years) average of 1·75 mm year−1 (after compaction) was based on 14C dates, while a short‐term sedimentation rate of 0·8 mm was determined for a single, relatively small, seasonal flood in 1994 using sediment traps. However, short‐term sedimentation rates vary considerably over the floodplain, with levees aggrading up to four times faster than floodbasins. Channels of the upper Columbia River anastomosed reach follow a consistent pattern in their development, with each stage being characterized by different morphology and processes. Channel evolution comprises the following succession: (1) avulsion stage, in which a crevasse splay channel deepens by scour and levee sedimentation; (2) widening and deepening stage, in which bank slumping and bed scouring dominates; (3) infilling stage, in which either channel narrowing (bank accretion) or channel shallowing (bed accretion) takes place; and (4) abandonment stage, in which the residual (remnant) channel is filled exclusively by silt, clay and organic material. Vertical stacking (super‐ imposition) of active channels on recent channel‐fill sand bodies is a notable feature of the upper Columbia River, which suggests that reoccupation of residual channels is a common process.
A consideration of the dune:antidune transition in fine gravel
Authors: Carling Paul A. , Shvidchenko Andrey B. 
Published: March 2003

AbstractHydraulic data defining the dune:antidune transition in fine gravel are compared with potential flow theory, and information is drawn from published experiments and field‐based studies. Attention is given to both transitional bedforms and the development of downstream‐migrating antidunes. In the latter case, most data pertain to sand beds and not to gravel. Empirical data provide some weak support for the theoretical notion that the transition occurs at progressively lower Froude numbers at greater relative depths. Although a critical Froude number of 0·84 may reasonably be applied for the beginning of the dune to antidune transformation, lag effects (and a possible depth limitation) ensure that transitional bedforms may persist across a broad range of Froude numbers from 0·5 to 1·8. This latter observation has great relevance for palaeohydraulic estimates derived from outcrop data. Whereas the application of theoretical bedform existence fields, based upon potential flow theory, to fine gravel was previously purely speculative, the addition of experimental and field data to these plots provides a degree of confidence in applying stability theory to practical geological problems. For the first time, laboratory data pertaining to downstream‐migrating gravel antidunes are compared with theory. These bedforms have been reported from certain experimental near‐critical flows above sand or gravel beds, but have been observed infrequently in natural streams. However, there are no detailed studies from natural rivers and only a few contentious identifications from outcrops. Nevertheless, the limited hydraulic data conform to theoretical expectations.
Re‐interpretation of the existence of a primitive plume under Australia based on neon isotope fractionation during step heating
Authors: Gautheron Cécile , Moreira Manuel 
Published: March 2003

ABSTRACT The origin of the volcanism in south‐eastern Australia is poorly understood. Matsumoto and collaborators found near solar neon isotope values in measurements obtained by step heating apatites in ultramafic xenoliths from Bullenmerri (SE Australia), and proposed that these values result from the presence of a primitive plume. However, the results of simple diffusion models indicate that the neon isotopic signature observed by Matsumoto et al. can be generated by mass fractionation during step heating. If such mass fractionation does occur during step heating, then neither neon nor helium isotopes require the presence of primitive mantle, and the rare gas observations are consistent with the involvement of MORB‐source mantle in the generation of south‐eastern Australian volcanics. These results show that both the acquisition and the interpretation of step heating data should be carefully controlled and that a mineral crushing technique may yield more reliable analyses.
Cloning and characterization of the gene encoding the endo polygalacturonase‐inhibiting protein (PGIP) of Phaseolus vulgaris L.
Authors: Toubart Patrick , Desiderio Angiola , Salvi Giovanni , Cervone Felice , Daroda Lorenza , De Lorenzo Giulia , Bergmann Carl , Darvill Alan G. , Albersheim Peter 
Published: March 2003

SummaryPolygalacturonase‐inhibiting protein (PGIP) is a cell wall protein purified from hypocotyls of true bean (Phaseolus vulgaris L.). PGIP inhibits fungal endopolygalacturonases and is considered to be an important factor for plant resistance to phytopathogenic fungi (Albersheim and Anderson, 1971; Cervone et al., 1987). The amino acid sequences of the N‐terminus and one internal tryptic peptide of the PGIP purified from P. vulgaris cv. Pinto were used to design redundant oligonucleotides that were successfully utilized as primers in a polymerase chain reaction (PCR) with total DNA of P. vulgaris as a template. A DNA band of 758 bp (a specific PCR amplification product of part of the gene coding for PGIP) was isolated and cloned. By using the 758‐bp DNA as a hybridization probe, a lambda clone containing the PGIP gene was isolated from a genomic library of P. vulgaris cv. Saxa. The coding and immediate flanking regions of the PGIP gene, contained on a subcloned 3.3 kb Sa/I–Sa/I DNA fragment, were sequenced. A single, continuous ORF of 1026 nt (342 amino acids) was present in the genomic clone. The nucleotide and deduced amino acid sequences of the PGIP gene showed no significant similarity with any known databank sequence. Northern blotting analysis of poly(A)+ RNAs, isolated from various tissues of bean seedlings or from suspension‐cultured bean cells, were also performed using the cloned PCR‐generated DNA as a probe. A 1.2 kb transcript was detected in suspension‐cultured cells and, to a lesser extent, in leaves, hypocotyls, and flowers. A cDNA clone containing part of the coding region for the PGIP (from nt 345 to the poly(A) tail) was isolated from a λgt11 cDNA library prepared from poly(A)+ RNA isolated from suspension‐cultured cells of P. vulgaris cv. Pinto. The nucleotide and deduced amino acid sequences of the PGIP genes from the two different cultivars shared 96.4% and 97.4% identity, respectively.
Isolation and characterization of a cDNA clone corresponding to the Rt locus of Petunia hybrida
Authors: Brugliera Filippa , Holton Timothy A. , Stevenson Trevor W. , Farcy Eliane , Lu Chin‐Yi , Cornish Edwina C. 
Published: March 2003

SummaryWe have isolated, via differential screening of a Petunia hybrida petal cDNA library, a cDNA clone that corresponds to the Rt locus which controls the conversion of anthocyanidin‐3‐glucosides to anthocyanidin‐3‐rutinosides by the UDP rhamnose: anthocyanidin‐3‐glucoside rhamnosyltransferase (3RT). The cDNA encodes a 469 amino acid long polypeptide with regions of similarity to the UDP glucose: flavonoid glucosyltransferases (3GT) from barley and maize. Some sequence similarity was also observed with non‐plant glycosyltransferases. Two aberrant transcripts are present in most of the rt/rt petunia lines examined. Excision of a transposon from an unstable Rt locus of one petunia line (Tr38) is associated with a change in transcript size back to wild‐type. The Rt transcript is most abundant in petals from flowers at an early stage of development and levels decline as the flower matures. Transcripts are also detected in the style and anthers but not in leaf, stem, root, petiole, ovary or sepals. Incubation of leaves in glucose under high light conditions induces the expression of the Rt gene as well as other flavonoid pathway genes. In situ hybridization revealed that the Rt transcript predominantly accumulates in the epidermal cells of the petal, the site of anthocyanin accumulation.
Transposition of a Ds element from a plasmid into the plant genome in Nicotiana plumbaginifolia protoplast‐derived cells
Authors: Houba‐Hérin Nicole , Domin Monique , Pédron Jacques 
Published: March 2003

Summary Nicotiana plumbaginifolia haploid protoplasts were co‐transformed with two plasmids, one with a NPT‐II/Ds element and one with a gene encoding an amino‐terminal truncated Ac transposase. It is shown that Ds can efficiently transpose from extrachromosomal DNA to N. plumbaginifolia chromosomes when the Ac transposase gene is present in trans. Ds has been shown to have transposed into the plant genome in a limited number of copies (1.9 copies per genome), for 21/32 transgenic lines tested. The flanking sequences present in the original plasmid are missing in these 21 plants. In only two of 21 plants was part of the transposase construct integrated. By segregation analysis of transgenic progeny, Ds was shown to be present in the heterozygous state in 10 lines even though haploid protoplasts had been originally transformed. This observation could indicate that integration occurred after or during DNA replication that leads to protoplast diploidization.
Molecular characterization of Arabidopsis thaliana cDNAs encoding three purine biosynthetic enzymes
Authors: Schnorr Kirk M. , Nygaard Per , Laloue Michel 
Published: March 2003

SummaryGlycinamide ribonucleotide (GAR) synthetase, GAR transformylase and aminoimidazole ribonucleotide (AIR) synthetase are the second, third and fifth enzymes in the 10‐step de novo purine biosynthetic pathway. From a cDNA library of Arabidopsis thaliana, cDNAs encoding the above three enzymes were cloned by functional complementation of corresponding Escherichia coli mutants. Each of the cDNAs encode peptides comprising the complete enzymatic domain of either GAR synthetase, GAR transformylase or AIR synthetase. Comparisons of the three Arabidopsis purine biosynthetic enzymes with corresponding enzymes/polypeptide‐fragments from procaryotic and eucaryotic sources indicate a high degree of conserved homology at the amino acid level, in particular with procaryotic enzymes. Assays from extracts of E. coli expressing the complementing clones verified the specific enzymatic activity of Arabidopsis GAR synthetase and GAR transformylase. Sequence analysis, as well as Northern blot analysis indicate that Arabidopsis has single and monofunctional enzymes. In this respect the organization of these three plant purine biosynthesis genes is fundamentally different from the multifunctional purine biosynthesis enzymes characteristic of other eucaryotes and instead resembles the one gene, one enzyme relationship found in procaryotes.
An aldose reductase homologous gene from barley: regulation and function
Authors: Roncarati Renza , Salamini Francesco , Bartels Dorothea 
Published: March 2003

The expression of a barley gene homologous to aldose reductase and aldehyde reductase is restricted to the embryo and temporally correlated with its acquisition of desiccation tolerance. In the work presented, two aspects of this barley gene were investigated: its transcriptional regulation and the initial characterization of the enzymatic function. The transcriptional regulation of the gene was studied in transgenic tobacco by analysing the expression of chimeric genes containing 5′ sequences of the barley gene transcriptionally fused to the GUS reporter gene. This functional analysis of the promoter revealed that a 1364 bp 5′ fragment confers the appropriate pattern of expression to the reporter gene in tobacco and that a short promoter fragment (−114 to +75) containing the sequence TACGTGGC, homologous to plant G‐box elements, is sufficient for developmental expression during embryogenesis.To investigate the enzymatic properties of the gene product the wild‐type protein and a mutant carrying a lysine 259 to methionine substitution were overexpressed in a procaryotic system and purified to homogeneity. The wild‐type protein exhibits aldose reductase activity in the reduction of dl‐glyceraldehyde and d‐erythrose specifically using NADPH as co‐factor whereas the mutant shows markedly reduced activity. However, the barley protein possesses some properties different to those of animal aldose and aldehyde reductases and its biological target still needs to be identified.