bluuebunny/crossref_metadata_2025_split huggingface dataset:
Common polymorphisms and alternative splicing in the ILT3 gene are not associated with atopy
Authors: Heinzmann A. , Blattmann S. , Forster J. , Kuehr J. , Deichmann K. A. 
Published: March 2003

AbstractRecently, a linkage of the chromosomal region 19q13.4 with bronchial asthma has been demonstrated. This region harbours the so‐called leucocyte receptor cluster with the gene for immunoglobulin‐like‐transcript 3 (ILT3) as a member. ILT3 represents an inhibitory receptor bearing three immunoreceptor tyrosine inhibitory motifs (ITIM). The protein mediates downregulation of cell activation through recruitment of different SH2‐containing protein tyrosine phosphatases. With regard to the negative immunoregulatory function particularly on B‐cells, ILT3 represents a candidate gene for atopy and asthma. The aim of this study was to screen for common polymorphisms in the gene coding for ILT3 and to test for association with the atopic phenotype. Using single‐stranded conformal polymorphism‐analysis and direct genomic sequencing seven polymorphisms, three mutations, a common deletion of 7 bp in the third intron and evidence for further alternative splicing of the ILT3 gene were found. Although no association was found with atopy phenotypes, it might prove useful to test for association with bronchial asthma.
A novel locus affecting serum levels of IgG2a maps to the murine H2 region
Authors: Matthews V. B. , Christiansen F. T. , Price P. 
Published: March 2003

AbstractThe effects of genes in the murine H2 region on basal immunoglobulin levels were investigated and ratios of IgG1/IgG2a were calculated, as low ratios indicate a Th1 cytokine mileu. H2b mice with B10 or BALB genetic backgrounds had higher levels of IgG2a than H2k and H2d congenic strains, and hence had low IgG1/IgG2a ratios. B10 (H2b) mice generally had high levels of IgG2b, IgG3, IgA and IgM, but this outcome was more variable. The high IgG2a phenotype was denoted Igis1 (Immunoglobulin isotype‐1) and mapped telomeric of IEβ using B10.A(4R) mice (high IgG2a) and B10.A(3R) and B10.A(5R) mice (low IgG2a). Further mapping in B10.A(2R), B10.A(1R) and B10.A(18R) mice placed Igis1 in the 27kb region between G7c and G7e.
CD154 polymorphism in Spanish populations. Differences in the allelic distribution between Canary Islanders and Peninsulars
Authors: Citores M. J. , Pérez‐Aciego P. , Rodríguez‐Gallego C. , Contreras‐Martín B. , García‐Laorden I. , Durántez A. 
Published: March 2003

AbstractThe CD154 gene contains a dinucleotide repeat (CA)n in the 3′ untranslated region. Allelic distribution in Spanish populations from two areas with different genetic background, the Canary Islands and Peninsula, are described. Seven alleles with different allelic distribution between the two groups, were found. This represents a highly polymorphic marker, useful for genetic studies on a critical molecule in immunity.
Cattle MHC genes DOA and DOB: sequence polymorphisms and assignments to the class IIb region
Authors: Gelhaus A. , Förster B. 
Published: March 2003

SummaryIn a study of the genetic polymorphism of the second exons of the cattle DOA and DOB genes, two and four allelic variants were detected, respectively. In the predicted amino acid sequence, the DOA polymorphism corresponded to variation at the respective residue position, whereas the nucleotide substitutions in the DOB gene were non‐informative. PCR‐RFLP assays were developed for DOA and DOB typing, and both loci were genetically mapped to the BoLA class IIb region by linkage analysis in the International Bovine Reference Panel. The single nucleotide polymorphisms detected in the BoLA‐DOA and ‐DOB genes enable these loci to be used as markers in genetic trait analyses.
Molecular cloning of four lambda light chain cDNAs from the Australian brushtail possum Trichosurus vulpecula
Authors: Belov K. , Harrison G. A. , Miller R. D. , Cooper D. W. 
Published: March 2003

SummaryA brushtail possum mesenteric lymph node cDNA library was screened with a grey short‐tail opossum Cλ probe and four immunoglobulin lambda cDNAs were isolated. Two of the isolated clones (L5 and L10) contained identical framework 4 regions and constant regions (but different variable regions), suggesting that the possum lambda locus is organized as multiple J‐C pairs — a feature seen in the opossum and placental mammals. The cloning of the lambda light chain cDNAs signifies the completion of the basic molecular characterization of the brushtail possum immunoglobulin repertoire. The availability of this sequence data will allow extensive analysis of the immune response of the brushtail possum at the molecular level, as well as the development of specific immunological reagents for detection of immunoglobulin molecules at the protein level.
Structural basis of allotypes of ecto‐nucleotide pyrophosphatase/phosphodiesterase (plasma cell membrane glycoprotein PC‐1) in the mouse and rat, and analysis of allele‐specific xenogeneic antibodies
Authors: Banakh I. , Sali A. , Dubljevic V. , Grobben B. , Slegers H. , Goding J. W. 
Published: March 2003

SummaryEcto‐nucleotide pyrophosphatase/phosphodiesterases (E‐NPPs) have been implicated in bone calcification, type II diabetes, control of purinergic signalling and tumour invasion. The gene for the plasma cell membrane glycoprotein PC‐1 in the mouse (Enpp1) has been known since 1970 to exist in two allelic forms, but their structural basis was heretofore unknown. We show that the Enpp1a and Enpp1b alleles differ by only two amino acids, at positions 650 and 679 in the C‐terminal nuclease‐like domain. Histidine 650 but not arginine 679 forms an essential part of the Enpp1a epitope recognized by monoclonal antibody IR‐518. Sequences of LEW and LOU rats and the rat glioma cell line C6 differ from that of the mouse by about 60 amino acids. The LOU and C6 cell line sequences differ by only three amino acids, but differ from the LEW sequence by 10 amino acids. All three rat strains possess the mouse Enpp1b allele at positions 650 and 679. Despite numerous other differences from the mouse, rats immunized with Enpp1a mouse cells have generated monoclonal antibodies specific for the Enpp1a allele, suggesting that amino acids 650 and 679 may be particularly immunogenic. The cytoplasmic tails of the mouse and rat are highly conserved, but are significantly different from human cytoplasmic tails.
Immunoprecipitation and isoelectric focusing of sheep MHC class I antigens reveal higher complexity than serology
Authors: Jugo B. M. , Joosten I. , Grosfeld‐Stulemeyer M. , Amorena B. , Hensen E. J. 
Published: March 2003

SummaryBiochemical and serological methods were used to characterize sheep MHC class I polymorphism at the product level. The cells of 65 selected animals were subjected to immunoprecipitation and one‐dimensional isoelectric focusing (IEF) with two cross‐reacting monoclonal antibodies, B1.1G6 and HC‐10. We were able to define up to 18 distinct haplotypes in the Latxa breed sample. Most of the locally defined serological specificities were confirmed or subdivided by biochemical typing. As IEF detected antigens not yet defined by serology, it provided us with a guide to producing more specific antisera by appropriate immunizations. Lastly, evidence of expression of two class I loci products was found.
Definition of permissible and immunogenic HLA antigens based on epitope analysis of the HLA specific antibodies produced in sensitized patients
Authors: Papassavas A. C. , Stavropoulos‐Giokas C. , Boletis J. , Ioannou S. , Iniotaki‐Theodoraki A. , Kostakis A. 
Published: March 2003

SummaryThe goal of this study was to develop an accurate protocol whereby detection of acceptable HLA‐A and ‐B mismatches is based on epitope analysis of HLA class I specific antibodies detected in the serum of highly sensitized patients awaiting a kidney retransplant. A total of 400 serum samples from 44 highly sensitized patients with panel reactive antibodies (PRA) of ≥ 60% were collected during a 3‐year follow‐up period. All patients had been sensitized from a previous graft. In order to define the specificities of the HLA class I specific antibodies, two techniques were used in parallel: the antihuman globulin augmented complement‐dependent cytotoxicity (CDC) technique and an enzyme‐linked immunoabsorbent assay (ELISA) technique. Epitope identification was based on class I HLA antigen sequencing, where the unique epitope configuration on one HLA antigen represented the private epitope of the specific HLA antigen, and epitopes shared by more than one HLA antigen represented public determinants. The epitope prediction for the immunogenic HLA epitopes was based on an MHC database. For each highly sensitized patient, antibody specificities against actual and ‘at risk’ epitopes were defined. Following epitope analysis, all HLA antigens that did not express the actual and/or ‘at risk’ immunogenic epitopes were considered as acceptable mismatches of epitope analysis. The cytotoxicity of highly sensitized patients was determined using two different panels of selected, separated T lymphocytes. HLA class I specific IgG antibodies against 69 actual and 86 ‘at risk’ epitopes were detected. In all patients, a large number of acceptable mismatches were defined. These included a large number of HLA antigens, corresponding to both HLA‐A and ‐B loci. Our study introduces an accurate protocol for the detection of acceptable mismatches in highly sensitized patients. According to this protocol, the detailed description of immunogenic HLA specific epitope targets, against which HLA class I specific antibodies are directed, is a useful tool for the detection of acceptable mismatches in highly sensitized patients. This may lead to reduced production of HLA class I specific antibodies and, consequently, improved graft survival.
Surface morphology of quartz grains from tropical soils and its significance for assessing soil weathering
Authors: Marcelino V. , Mussche G. , Stoops G. 
Published: March 2003

SummaryThe surface morphology of quartz grains can indicate the degree of weathering of soil material. We have compared two methods of assessing the relative weathering of soils on the basis of differences in the surface morphology of quartz sand grains in a catena of soils in Rwanda. One method is based on the presence or absence of surface features indicative of weathering or freshness, while the other uses the frequency and size of dissolution etch pits. A ranking of relative weathering could be obtained using the first technique for the slightly and somewhat weathered soils but not for the weathered soils. On the other hand, weathering trends and differences between the horizons studied were detected in weathered soils using the second method. The introduction of more specific definitions of the weathering classes used in the latter method leads to clear improvement of the inter‐observer reproducibility of the weathering classification.The surface features on the quartz grains suggest that the soil at the summit is less weathered than the other soils of the sequence. Quartz grains from the well‐drained soils on the slopes, which are subjected to more intense leaching and thus to stronger chemical weathering, have more triangular etch pits and chatter marks. In the imperfectly drained soils in the valley bottom quartz grains are less etched because dissolution is inhibited by the oversaturation in silica of the drainage waters.
The influence of soil processes on carbon isotope distribution and turnover in the British uplands
Authors: Bol R. A. , Harkness D. D. , Huang Y. , Howard D. M. 
Published: March 2003

SummaryUnderstanding the natural variation of carbon within the soil, and between soil types, is crucial to improve predictive models of carbon cycling in high and mid‐latitude ecosystems in response to global warming. We measured the carbon isotope distributions (12C, 13C and 14C) in soil organic matter (SOM) from Podzols, Brown Podzolic soils and Stagnohumic Gleysols from the British uplands, which were then compared with the total amounts and turnover of carbon in these soils. We did so by sampling at 2‐cm intervals down six profiles of each soil type. The average amount of carbon stored in the top 28 cm of the Stagnohumic Gleysols is twice that of the other two soils. The 13C content and 14C age show a general increase with depth in all soils, and there is also a significant correlation between isotopic variation and the main pedogenic features. The latter suggests that soil‐forming processes are significant in determining the carbon isotope signatures retained in SOM. Organic matter formed since 1960 is not found below 5 cm in any of the soils. Evidently organic detritus in the surface layers (LF and Oh) is rapidly mineralized. This accords with our modelled net annual C fluxes which show that more than 80% of the CO2 emanating from these soils is derived from the top 5 cm of each profile. Although these soils contain much carbon, they do not appear to assimilate and retain SOM rapidly. The mean residence time of most of their carbon is in the 2–50 years range, so the soils are fairly ineffective sinks for excess CO2 in the atmosphere. Under the predicted future ‘greenhouse’ climate, likely to favour more rapid microbial decomposition of organic materials, these soils are a potential source of CO2 and are therefore likely to accelerate global warming.
Thermal stability and composition of mineral‐bound organic matter in density fractions of soil
Authors: Schulten H. ‐R. , Leinweber P. 
Published: March 2003

SummaryHeavy density fractions of soil contain organic matter tightly bound to the surface of soil minerals. The chemical composition and ecological meaning of non‐metabolic decomposition products and microbial metabolites in organic–mineral bonds is poorly understood. Therefore, we investigated the heavy fraction (density > 2 g cm–3) from the topsoil of a Gleysol (Bainsville, Ottawa, Canada). It accounted for 952 g kg–1 of soil and contained 19 g kg–1 of organic C. Pyrolysis‐field ionization mass spectra showed intensive signals of carbohydrates, and phenols and lignin monomers, alkylaromatics (mostly aromatic) N‐containing compounds, and peptides. These classes of compound have been proposed as structural building blocks of soil organic matter. In comparison, the light fraction (density > 2 g cm–3) was richer in lignin dimers, lipids, sterols, suberin and fatty acids which clearly indicate residues of plants and biota. To confirm the composition and stability of mineral‐bound organic matter, we also investigated the heavy fraction (density > 2.2 g cm–3) from clay‐, silt‐ and sand‐sized separates of the topsoil of a Chernozem (Bad Lauchstädt, Germany). These heavy size separates differed in their mass spectra but were generally characterized by volatilization maxima of alkylaromatics, lipids and sterols at about 500°C. We think that the observed high‐temperature volatilization of these structural building blocks of soil organic matter is indicative of the organic–mineral bonds. Some unexpected low‐temperature volatilization of carbohydrates, N‐containing compounds, peptides, and phenols and lignin monomers was assigned to hot‐water‐extractable organic matter which accounted for 7–27% of the carbon and nitrogen in the heavy fractions. As this material is known to be mineralizable, our study indicates that these constituents of the heavy density fractions are degradable by micro‐organisms and involved in the turnover of soil organic matter.
Changes in soil chemistry accompanying acidification over more than 100 years under woodland and grass at Rothamsted Experimental Station, UK
Authors: Blake L. , Goulding K. W. T. , Mott C. J. B. , Johnston A. E. 
Published: March 2003

SummaryWe have examined the effect that acid deposition and other sources of acidity have had over the last 110–140 years on soil under woodland (Broadbalk and Geescroft Wildernesses) and grassland (Park Grass) comprising some of the Classical Experiments at Rothamsted Experimental Station. Changes in soil chemistry have been followed by analysing some of the unique archive of stored samples for pH, water‐soluble and exchangeable base cations, aluminium, iron and manganese, exchangeable acidity, cation exchange capacity (CEC) and soluble anions. Proton balances and historical data show the importance of acid deposition to acidification and concomitant changes in the chemistry of the soil. The pH of the surface soil of Geescroft Wilderness has fallen from 6.2 to 3.8 since 1883. The decrease in the pH of the unlimed, unfertilized plot on Park Grass was less over a similar period (from pH 5.2 to 4.2), illustrating the significant effect of the woodland canopy on the interception of acidifying pollutants. The effect of increasing acidity on the soil chemistry of Geescroft Wilderness is seen in its decreasing base saturation and CEC, with base cations moving down the soil profile. Clay minerals are being irreversibly weathered, and Mn and Al progressively mobilized, so that today Al occupies 70% of the exchange complex in the surface soil. Even with present reductions in sulphur deposition critical loads for sulphur, nitrogen and acidity are still exceeded. Such semi‐natural ecosystems are unsustainable under the current climate of pollution.
Surface podzolization in Cambisols under deciduous forest in the Belgian loess belt
Authors: Brahy V. , Titeux H. , Iserentant A. , Delvaux B. 
Published: March 2003

SummarySurface podzolization involves the migration of metal–humus complexes to a depth of a few centimetres. In acid soils derived from loess, this process has been diagnosed mainly by morphological observation. We investigated this process in a toposequence of Luvisols and Cambisols on loess using selective extraction and mineralogical data as well as characteristics of the leaf litter. The humus type (O and OAh horizons) is a moder in the three Luvisols and one of the Cambisols, whereas it is a fibrimor in the two other Cambisols. The contents in total alkaline and alkaline‐earth cations range from 35 to 60 cmolckg−1in the fibrimor and from 40 to 90 cmolckg−1in the moder humus. In the two Cambisols with fibrimor smectite occurs in the clay fraction of the Ah horizon; Fe–humus complexes seem to have moved, but no more than 9 cm, from the Ah to the AB horizon beneath. Relative to the Ah horizon, the upper part of the AB has larger tetraborate‐extractable Fe/Al ratio and optical density of the oxalate extract. Such features converge to diagnose surface podzolization in the Cambisols with fibrimor. However, they were not detected in the Cambisol and Luvisols with moder. In the two Cambisols with fibrimor, surface podzolization is consistent with (i) their smaller iron content, (ii) their more advanced weathering stage and (iii) their lower acid neutralizing capacity.
Enchytraeid worms (Oligochaeta) enhance mineralization of carbon in organic upland soils
Authors: Cole L. , Bardgett R. D. , Ineson P. 
Published: March 2003

SummaryWe investigated the functional role of enchytraeid worms (Oligochaeta) in organic upland soils experimentally, because that role of these animals is little known. We made microcosms of intact soil cores cut from two depths, 0–4 cm and 4–8 cm, of a Cambic Stagnohumic Gley from the Moor House National Nature Reserve (UK). Enchytraeids were added to half of the microcosms, resulting in four treatments: litter (L), litter + enchytraeids (L + E), soil (S) and soil + enchytraeids (S + E). Triplicates of each treatment were established, and all microcosms (60) were then incubated in the dark at 15°C, arranged in a fully randomized design. The experiment ran over 110 days, with five destructive harvests at days 10, 25, 50, 75 and 110, when microbial measurements (soil respiration and biomass C) as well as measures of decomposition (nutrient concentration in leachates) were made. Enchytraeids almost doubled the availability of organic carbon (measured as dissolved organic carbon in soil leachates) in the surface (0–4 cm) microcosms only. There were no effects of enchytraeids on the release of inorganic N or P from either soil horizon, although the release of ammonium and phosphate was correlated with the number of enchytraeids in the microcosms. The depth from which the soil was taken exerted a strong influence on nutrient leaching, with almost six times more ammonium and four times more carbon being leached from the surface (0–4 cm) layer than from the more decomposed (4–8 cm) horizon. There was little nitrate leaching from any of the treatments, with only one‐quarter as much nitrate leached from the surface (0–4 cm) as from the subsurface (4–8 cm) horizon. Enchytraeids had no detectable effect on microbial biomass, but they increased microbial respiration by 35% in the surface (0–4 cm) horizon. Because they enhanced microbial activity in this horizon we suggest that enchytraeids indirectly drive the processes of decomposition and nutrient mineralization in organic upland soils.
Ammonium fluoride extraction for determining inorganic sulphur in acid forest soils
Authors: Prietzel J. , Hirsch C. 
Published: March 2003

SummaryCurrent methods for determining inorganic sulphur (S) in aerated mineral soil horizons often result in underestimates. To overcome this defect we developed a new method combining a batch extraction with 0.5 m NH4F solution at a soil:solution ratio of 1:5 with a subsequent analysis of the mobilized SO42– by ion chromatography. The ammonium fluoride extraction enables us to characterize inorganic sulphate in non‐calcareous forest soils. It is more efficient than conventional procedures in which inorganic S is extracted with phosphate or bicarbonate solution. In contrast to the extraction with strongly alkaline reagents (NaOH, KOH, LiOH), the NH4+–NH3 buffer system in NH4F prevents the pH of the suspension from exceeding 9.0 and thus the undesired conversion of organic S into SO42– by auto‐oxidation and hydrolysis of ester sulphate. In a comparison we demonstrated that the inorganic S in six German forest soils is underestimated by up to 50% or 200 kg S ha−1 in the uppermost 60 cm, if it is assessed by extraction with 0.016 m KH2PO4 or 0.5 m NaHCO3 instead of 0.5 m NH4F. Conversely, the pool of ester sulphate is overestimated almost threefold.