bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hsa, an adhesin of Streptococcus gordonii DL1, binds to α2‐3‐linked sialic acid on glycophorin A of the erythrocyte membrane
Authors: Yajima Ayako , Urano‐Tashiro Yumiko , Shimazu Kisaki , Takashima Eizo , Takahashi Yukihiro , Konishi Kiyoshi 
Published: April 2008

ABSTRACTBacterial recognition of host sialic acid‐containing receptors plays an important role in microbial colonization of the human oral cavity. The aggregation of human platelets by Streptococcus gordonii DL1 is implicated in the pathogenesis of infective endocarditis. In addition, we consider that hemagglutination of this organism may act as an additive factor to increase the severity of this disease. We previously reported that this interaction requires the bacterial expression of a 203‐kDa protein (Hsa), which has sialic acid‐binding activity. In the present study, we confirmed that erythrocyte surface sialoglycoproteins are the receptors for Hsa. We examined the effects of proteinase K, chymotrypsin, phospholipase C, and α(2‐3) or α(2‐3, 6, 8) neuraminidase on hemagglutination activity and found that the interaction occurs between Hsa and α2‐3‐linked sialic acid‐containing proteins of erythrocytes. We expressed recombinant NR2, which is the putative binding domain of Hsa, fused with GST in Escherichia coli BL21. Dot‐blot analysis demonstrated that GST‐HsaNR2 binds both glycophorin A (GPA) and band 3. Moreover, GPA and a small amount of band 3 were detected by GST pull‐down assays. These findings indicate that S. gordonii Hsa specifically binds to GPA and band 3, α2‐3‐linked sialic acid membrane glycoproteins.
Generation and characterization of human monoclonal antibodies to G5, a linear neutralization epitope on glycoprotein of rabies virus, by phage display technology
Authors: Zhao Xiao‐Ling , Yin Jun , Chen Wei‐Qiang , Jiang Ming , Yang Guan , Yang Zhi‐Hua 
Published: April 2008

ABSTRACTThe aim of the present study was to discover distinct human MAbs to RV with high neutralizing potency and a broad neutralization spectrum. A phage display technology was used to produce human scFv to G5, a conserved linear neutralization epitope on Gp of RV. A phage display scFv library with 6 × 107 members was constructed and the phage‐scFv with ‘antigen‐binding’ activities were selected with synthetic peptide G5‐24. The obtained scFv genes were cloned into pET22b(+)/BL21(DE3) and from this we prepared purified scFv fragments. The assay of the specificity characteristics and neutralization capacity showed that two distinct clones with new human immunoglobulin V genes can recognize G5 specifically as well as neutralize different RV strains. They have potential for inclusion in an antibodies combination aimed for use in rabies PEP.
Disruption of the association of 73 kDa heat shock cognate protein with transporters associated with antigen processing (TAP) decreases TAP‐dependent translocation of antigenic peptides into the endoplasmic reticulum
Authors: Kamiguchi Kenjiro , Torigoe Toshihiko , Fujiwara Osamutaro , Ohshima Shin , Hirohashi Yoshihiko , Sahara Hiroeki , Hirai Itaru , Kohgo Yutaka , Sato Noriyuki 
Published: April 2008

ABSTRACTMajor histocompatibility complex class I‐bound antigenic peptides generated in the cytosol are translocated into the ER by TAP. In the present study, the physical association of HSC73 with TAP in human lymphoblastoid T1 cells was demonstrated. The dissociation was induced in the presence of 10 mM ATP, indicating that the ADP‐binding form of HSC73 might be associated with TAP. We found that HSC73‐binding immunosuppressant, MeDSG disrupted the HSC73‐TAP association, whereas it did not affect the binding of HSC73 to a substrate protein. MHC class I expression on the cell surface was also downregulated. Then, the effect of MeDSG on the TAP‐mediated ER translocation was examined using two homologous model peptides, NGT‐Bw4 and NGT‐Bw6, which had distinct binding affinity to HSC73. Although high‐affinity peptide NGT‐Bw4 was translocated by TAP, low‐affinity peptide NGT‐Bw6 was not. The TAP‐dependent translocation of NGT‐Bw4 was abolished in the presence of MeDSG. Decreased presentation on the cell surface was shown for the human leukocyte antigen (HLA)‐A31‐restricted natural antigenic peptide F4.2, which had high affinity to HSC73, in the presence of MeDSG. It was indicated that disruption of the HSC73‐TAP association resulted in inhibition of TAP‐dependent translocation of HSC73‐bound peptides. Our findings highlighted an important role of HSC73 for feeding antigenic peptides to TAP, and suggested a possibility that a synthetic polyamine might inhibit the function of HSC73, thereby suppressing MHC class I‐restricted presentation of HSC73‐bound antigenic peptides.
Late Carboniferous foreland basin formation and Early Carboniferous stretching in Northwestern Europe: inferences from quantitative subsidence analyses in the Netherlands
Authors: Kombrink Henk , Leever Karen A. , Van Wees Jan‐Diederik , Van Bergen Frank , David Petra , Wong Theo E. 
Published: April 2008

ABSTRACTThe large thickness of Upper Carboniferous strata found in the Netherlands suggests that the area was subject to long‐term subsidence. However, the mechanisms responsible for subsidence are not quantified and are poorly known. In the area north of the London Brabant Massif, onshore United Kingdom, subsidence during the Namurian–Westphalian B has been explained by Dinantian rifting, followed by thermal subsidence. In contrast, south and east of the Netherlands, along the southern margin of the Northwest European Carboniferous Basin, flexural subsidence caused the development of a foreland basin. It has been proposed that foreland flexure due to Variscan orogenic loading was also responsible for Late Carboniferous subsidence in the Netherlands. In the first part of this paper, we present a series of modelling results in which the geometry and location of the Variscan foreland basin was calculated on the basis of kinematic reconstructions of the Variscan thrust system. Although several uncertainties exist, it is concluded that most subsidence calculated from well data in the Netherlands cannot be explained by flexural subsidence alone. Therefore, we investigated whether a Dinantian rifting event could adequately explain the observed subsidence by inverse modelling. The results show that if only a Dinantian rifting event is assumed, such as is found in the United Kingdom, a very high palaeowater depth at the end of the Dinantian is required to accommodate the Namurian–Westphalian B sedimentary sequence. To better explain the observed subsidence curves, we propose (1) an additional stretching event during the Namurian and (2) a model incorporating an extra dynamic component, which might well explain the very high wavelength of the observed subsidence compared with the wavelength of the predicted flexural foreland basin.
T‐cell regulation by CD46 and its relevance in multiple sclerosis
Authors: Astier Anne L. 
Published: April 2008

SummaryCD46 is a complement regulatory molecule expressed on every cell type, except for erythrocytes. While initially described as a regulator of complement activity, it later became a ‘magnet for pathogens’, binding to several viruses and bacteria. More recently, an alternative role for such complement molecules has emerged: they do regulate T‐cell immunity, affecting T‐cell proliferation and differentiation. In particular, CD46 stimulation induces Tr1 cells, regulatory T cells characterized by massive production of interleukin‐10 (IL‐10), a potent anti‐inflammatory cytokine. Hence, CD46 is likely to control inflammation. Indeed, data from CD46 transgenic mice highlight a role for CD46 in inflammation, with antagonist roles depending on the cytoplasmic tail being expressed. Furthermore, recent data have shown that CD46 is defective in multiple sclerosis, IL‐10 production being severely impaired in these patients. This lack of IL‐10 production probably participates in the inflammation observed in patients with multiple sclerosis. This review will summarize the data on CD46 and T cells, and how CD46 is likely involved in multiple sclerosis.
In situ detection of programmed cell death in Nicotiana tabacum leaves during senescence
Authors: UZELAC B. , JANOŠEVIĆ D. , BUDIMIR S. 
Published: April 2008

SummaryLeaf senescence is a highly regulated developmental process, during which cell constituents are dismantled in an ordered progression. The final death phase of senescence is a type of programmed cell death (PCD). We showed DNA fragmentation characteristic for PCD by terminal deoxynucleotidyl transferase‐mediated dUTP nick end labelling (TUNEL) assay not only in senescing leaves but also in young, still developing tobacco leaves.
Navigating transdermal diffusion with multiphoton fluorescence lifetime imaging
Authors: BIRD D.K. , SCHNEIDER A.L. , WATKINSON A.C. , FINNIN B. , SMITH T.A. 
Published: April 2008

SummaryWe demonstrate the potential of fluorescence lifetime imaging by time‐correlated single‐photon counting as a method for monitoring the transdermal diffusion pathway and diffusion rate of pharmaceuticals in human skin. The current application relies on observing subtle changes in the fluorescence lifetime of the intrinsic fluorophores present in the intracellular region between corneocytes of the stratum corneum. We have comprehensively characterized the measured fluorescence lifetimes from intracorneocyte junctions in three skin section types (dermatomed skin, epidermal membranes and stratum corneum) revealing statistically significant differences of the short lifetime component between each of the types, which we attribute to the sample preparation and imaging method. We show using epidermal membrane sections that application of a drug/solvent formulation consisting of ethinyl estradiol and spectroscopic grade ethanol to the surface gives rise to a slight but statistically significant shortening of the fluorescence lifetime of the long‐lived emitting species present in the sample, from approximately 2.8 ns to 2.5 ns. The method may be useful for future studies where the kinetics and pathways of a variety of applied formulations could be investigated.
Deciphering the distribution of organic components in brachiopod shells by confocal laser scanning microscopy
Authors: PÉREZ‐HUERTA A. , CUSACK M. , BALL A. , WILLIAMS C. T. , MACKAY S. 
Published: April 2008

SummaryCharacterization of the nature and distribution of organic components is crucial to understand shell formation in marine invertebrates. Although several techniques can provide detailed information at high spatial resolution, few of them are non‐destructive and informative in a larger structural context. We explore the use of confocal laser scanning microscopy (CLSM) to obtain a better understanding of the distribution of organic components in calcitic shells of brachiopods focusing on perforations (punctae) across the shell. Resulting intensities and patterns of fluorescence correspond well with the distribution of polysaccharides and proteins as reported in previous histological and biochemical studies. Confocal laser microscopy is, therefore, a useful tool to be combined with other techniques to improve our knowledge of biomineral structures in marine invertebrates.
Dynamic volume change measurements of cereal materials by environmental scanning electron microscopy and videomicroscopy
Authors: TANG X. , DE ROOIJ M. R. , VAN DUYNHOVEN J. , VAN BREUGEL K. 
Published: April 2008

SummaryMoisture migration induced volume change in cereal materials was studied by environmental scanning electron microscopy, videomicroscopy and stereoscopy. It is shown that the in situ volume change can be monitored by the changes of projection area with the assumption of isotropic swelling/shrinkage. The projection area change from videomicroscopy matches well with the volume change by stereoscopy after dimensional normalization. The arbitrary volume values in between two relative humidity levels are available by interpolating the equilibrium volumes at beginning and ending. The sorption/desorption curves were fitted by the ‘parallel exponential kinetics’ model, which described two independent, parallel processes as ‘slow’ and ‘fast’. In the low relative humidity range, sorption curves match well with the ‘parallel exponential kinetics’ model and the two parallel processes tend to be identical when relative humidity increases. The diffusivity of water moisture in a cracker, which was estimated by the half‐equilibrium principle, has a strong dependence on relative humidity.
A statistical approach for intensity loss compensation of confocal microscopy images
Authors: GOPINATH S. , WEN Q. , THAKOOR N. , LUBY‐PHELPS K. , GAO J. X. 
Published: April 2008

SummaryIn this paper, a probabilistic technique for compensation of intensity loss in confocal microscopy images is presented. For single‐colour‐labelled specimen, confocal microscopy images are modelled as a mixture of two Gaussian probability distribution functions, one representing the background and another corresponding to the foreground. Images are segmented into foreground and background by applying Expectation Maximization algorithm to the mixture. Final intensity compensation is carried out by scaling and shifting the original intensities with the help of parameters estimated for the foreground. Since foreground is separated to calculate the compensation parameters, the method is effective even when image structure changes from frame to frame. As intensity decay function is not used, complexity associated with estimation of the intensity decay function parameters is eliminated. In addition, images can be compensated out of order, as only information from the reference image is required for the compensation of any image. These properties make our method an ideal tool for intensity compensation of confocal microscopy images that suffer intensity loss due to absorption/scattering of light as well as photobleaching and the image can change structure from optical/temporal section‐to‐section due to changes in the depth of specimen or due to a live specimen. The proposed method was tested with a number of confocal microscopy image stacks and results are presented to demonstrate the effectiveness of the method.
Upgrading a microscope with a spiral phase plate
Authors: MAURER C. , JESACHER A. , FÜRHAPTER S. , BERNET S. , RITSCH‐MARTE M. 
Published: April 2008

SummaryWe present the implementation of a spiral phase plate in a standard bright‐field microscope to enhance the contrast of phase and amplitude samples. The method can be employed in all types of microscopy where standard phase contrast methods are applicable, for example, in bright‐field transmission or reflection microscopy using an illumination source with partial spatial coherence. The spiral phase filter is placed into an accessible Fourier plane of the imaging path of the microscope. It is shown that this produces not only a strong contrast enhancement but in theory also improves the spatial resolution of the microscope for white light. A series of different set‐ups for transmissive or reflective samples, including epi‐illumination, are presented to demonstrate the practical range of applications of this contrasting method. A minute shift of the spiral phase plate out of the centre results in relief‐like images that are similar to those obtained by differential interference contrast microscopy. A series of such relief‐like images can be numerically processed to obtain quantitative phase and amplitude information of the sample.
The Aspergillus nidulans FcyB cytosine‐purine scavenger is highly expressed during germination and in reproductive compartments and is downregulated by endocytosis
Authors: Vlanti Anna , Diallinas George 
Published: April 2008

SummaryWe cloned and characterized an Aspergillus nidulans gene, called fcyB, encoding the closest homologue to the yeast Fcy2p/Fcy21p permeases. Deletion of fcyB (ΔfcyB) does not affect growth, development, reproduction or bulk purine uptake, but eliminates the leaky growth on purines of ΔazgAΔuapCΔuapA strains, lacking all known purine transporters, and confers resistance to the antifungal 5‐fluorocytosine. Kinetic analyses showed FcyB is a low‐capacity, high‐affinity, cytosine‐purine transporter sharing similar molecular interactions for substrate recognition with the yeast Fcy2p/Fcy21p carriers. fcyB transcription is highly activated during germination but drops at low constitutive levels throughout vegetative development. UaY‐mediated purine induction of fcyB transcription is only moderate, while ammonium represses transcription through an AreA‐dependent mechanism. A strain expressing FcyB–GFP confirms a low protein expression level in the plasma membrane of vegetative mycelia, but reveals an abundant expression in sexual and asexual compartments. FcyB–GFP was also shown to be downregulated by endocytosis in response to ammonia or the presence of cytosine. The expression profile of FcyB supports that its main physiological role is cytosine‐purine scavenging.
A malonyl‐CoA‐dependent switch in the bacterial response to a dysfunction of lipid metabolism
Authors: Schujman Gustavo E. , Altabe Silvia , De Mendoza Diego 
Published: April 2008

SummaryBacteria stringently regulate the synthesis of their membrane phospholipids, but the responsible regulatory mechanisms are incompletely understood. Bacillus subtilis FabF, the target of the mycotoxin cerulenin, catalyses the condensation of malonyl‐ACP with acyl‐ACP to extend the growing acyl chain by two carbons. Here we show that B. subtilis strains containing the fabF1 allele, which codes for the cerulenin‐insensitive protein FabF[I108F], overexpressed several genes involved in fatty acid and phospholipid biosynthesis (the fap regulon) and had significantly elevated levels of malonyl‐CoA. These results pinpointed FabF[I108F] as responsible for the increased malonyl‐CoA production, which in turn acts as an inducer of the fap regulon by impairing the binding of the FapR repressor to its DNA targets. Synthesis of acyl‐ACPs by a cell‐free fatty acid system prepared from fabF1 cells showed the accumulation of short‐ and medium‐chain acyl‐ACPs. These results indicate that the acyl‐ACP chain length acceptance of FabF[I108F] is biased towards shorter acyl‐ACPs. We also provide evidence that upregulation of FabF[I108F] is essential for survival and for resistance to cerulenin of fabF1 cells. These findings indicate that malonyl‐CoA is a key molecule to monitor lipid metabolism functioning and trigger appropriate genetic and biochemical adjustments to relieve dysfunctions of this essential metabolic pathway.
Early infection of Fagus sylvatica by Heterobasidion annosum sensu stricto
Authors: ŁAkomy P. , Cieślak R. 
Published: April 2008

Summary Heterobasidion annosum sensu stricto is the most important damaging agent in Scots pine stands planted on the former agricultural lands in Poland. The routine action in pine stands which have lost stability because of H. annosum root rot is to change stand management, including species conversion. In many cases, the Fagus sylvatica is used for this purpose. This study was the first assessment of widespread infection by H. annosum in young F. sylvatica plantations. Disease symptoms included atrophy and yellowing of leaves, wilting and the presence of pathogen sporocarps around the root collars of young trees. Heterobasidion annosum s. s. was observed on both 4‐ and 17‐year‐old beech. Based on annual increments, the disease could be present for 3–4 years before tree death. A high incidence of H. annosum in pine stumps of previous stands (80–100%) and dry periods in recent years may be the main reasons for such common infection of F. sylvatica. This work also showed that mice and frost were not the main killing factors F. sylvatica in plantations.
Geographic distribution, disease symptoms and pathogenicity of Phytophthora nemorosa and Phytophthora pseudosyringae in California, USA
Authors: Wickland A. C. , Jensen C. E. , Rizzo D. M. 
Published: April 2008

SummaryDuring the course of surveys for Phytophthora ramorum in coastal forests of California and Oregon, P. nemorosa and P. pseudosyringae were frequently isolated from foliage and stems of the same hosts as P. ramorum. Both species ranged from central California to Oregon within 50 km of the Pacific Ocean. Both were also found in the Sierra Nevada Mountains. Phytophthora nemorosa was primarily found infecting trees in coast redwood forests and was most often isolated from bay laurel leaves (Umbellularia californica), bleeding cankers on the main bole of tanoak (Lithocarpus densiflorus), and leaf and small stem tissue of redwood (Sequoia sempervirens). Phytophthora pseudosyringae was primarily isolated from hosts found in coast live oak woodlands. Bay laurel was the most common host while infection of coast live oak (Quercus agrifolia) stems was less frequent. Inoculation studies confirmed the pathogenicity of P. nemorosa and P. pseudosyringae on their most common hosts.
COMPARISON OF BRONCHOALVEOLAR LAVAGE HELPER/SUPPRESSOR T‐CELL RATIOS IN SARCOIDOSIS VERSUS OTHER INTERSTITIAL LUNG DISEASES
Authors: ROBINSON B. W. S. , ROSE A. H. , THOMPSON P. J. , HEY A. 
Published: April 2008

Abstract:In order to compare the frequency of elevated lymphocyte proportions and elevated Leu3/Leu2 (helper/inducer to suppressor/cytotoxic) ratios in sarcoidosis with those in clinically similar interstitial lung diseases (ILDs), bronchoalveolar lavage (BAL) lymphocyte proportions and Leu3/Leu2 ratios were determined for 20 patients with sarcoidosis and 30 patients with other (non‐sarcoidosis) ILDs [cryptogenic fibrosing alveolitis (seven), lung connective tissue disease (seven), extrinsic allergic alveolitis (four), lymphoproliferative disease (two), and asbestosis (ten)], as well as in eight control subjects. BAL lymphocyte proportions were elevated above control values in 19 (95%) patients with pulmonary sarcoidosis (mean value 36 ± 3%) but also in 12 (39%) patients with non‐sarcoidosis ILDs (mean value 17 ± 4%). Leu3/Leu2 ratios were over 2.5 in 15 (75%) of the sarcoidosis patients (mean ratio 4.4 ± 1). In all control subjects, however, and in all but one of the non‐sarcoidosis groups, Leu3/Leu2 ratios were below 2.5 (p < 0.001 for each compared to sarcoidosis patients). Helper/suppressor ratios over 2.5 are found in the majority of our sarcoidosis patients and, unlike raised lymphocyte proportions alone, are not commonly seen in other ILDs, suggesting that evaluation of BAL helper/suppressor cell ratios may be of value in the investigation of patients with ILD.
A COMPARATIVE STUDY OF T‐CELL DEPLETED AND NON‐DEPLETED MARROW TRANSPLANTATION FOR HEMATOLOGICAL MALIGNANCY
Authors: ATKINSON K. , BIGGS J. , COOLEY M. , FARRELLY H. , O'FLAHERTY E. , RAPHAEL H. , ASHBY M. , CONCANNON A. , DODDS A. , MORGAN G. , McKENZIE I. F. C. 
Published: April 2008

Abstract:Sixteen patients with hematological malignancy received cyclophosphamide (120 mg/kg), fractionated total body irradiation (12 Gy), oral cyclosporin, and an HLA‐identical sibling marrow transplant depleted of T cells by incubation with the monoclonal antibody anti‐HuLy‐m1 (CD2) and rabbit complement with (five patients) or without (11 patients) anti‐HuLy‐m8 (CD8). These 16 patients were compared historically to 84 patients with hematological malignancy receiving cyclophosphamide (120 mg/kg), fractionated total body irradiation (12 or 14 Gy), oral cyclosporin, and unmanipulated HLA‐identical sibling marrow, for parameters of engraftment and graft‐versus‐host disease (GVHD). Graft failure occurred in one of the 16 T‐cell depleted recipients and in one of the 84 non‐depleted recipients. Engraftment was slightly but significantly slower in the T‐cell depleted group and bacterial infections significantly more, frequent and severe than in the unmanipulated group. There was a suggestion that the severity of acute GVHD was reduced in those receiving T depleted marrow. Randomized trials will be necessary to determine if marrow T‐cell depletion results in superior long‐term leukemia‐free survival.