bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mixed‐lineage eosinophil/basophil crisis in MDS: a rare form of progression
Authors: Wimazal F. , Baumgartner C. , Sonneck K. , Zauner C. , Geissler P. , Schur S. , Samorapoompichit P. , Müllauer L. , Födinger M. , Agis H. , Sperr W. R. , Valent P. 
Published: April 2008

ABSTRACTBackground  Basophilic crisis and eosinophilia are well recognized features of advanced chronic myeloid leukaemia. In other myeloid neoplasms, however, transformation with marked basophilia and eosinophilia is considered unusual.Design  We examined the long‐term follow‐up of 322 patients with de novo myelodysplastic syndromes (MDS) to define the frequency of basophilic, eosinophilic and mixed lineage (basophilic and eosinophilic) transformation.Results  Of all patients, only one developed mixed lineage crisis (≥ 20% basophils and ≥ 20% eosinophils). In this patient, who initially suffered from chronic myelomonocytic leukaemia, basophils increased to 48% and eosinophils up to 31% at the time of progression. Mixed lineage crisis was not accompanied by an increase in blast cells or organomegaly. The presence of BCR/ABL and other relevant fusion gene products (FIP1L1/PDGFRA, AML1/ETO, PML/RARα, CBFβ/MYH11) were excluded by PCR. Myelomastocytic transformation/myelomastocytic leukaemia and primary mast cell disease were excluded by histology, KIT mutation analysis, electron microscopy and immunophenotyping. Basophils were thus found to be CD123+, CD203c+, BB1+, KIT‐ cells, and to express a functional IgE‐receptor. Among the other patients with MDS examined, 4(1·2%) were found to have marked basophilia (≥ 20%) and 7(2·1%) were found to have massive eosinophilia ( ≥ 20%), whereas mixed‐lineage crisis was detected in none of them.Conclusions  Mixed basophil/eosinophil crisis may develop in patients with MDS but is an extremely rare event.
Respiratory infection recurrence and passive smoking in early atherosclerosis in children and adolescents with type 1 diabetes
Authors: Odermarsky M. , Andersson S. , Pesonen E. , Sjöblad S. , Ylä‐Herttuala S. , Liuba P. 
Published: April 2008

ABSTRACTBackground  Optimal glucose control in juvenile type 1 diabetes mellitus is necessary but not sufficient to reduce the burden of cardiovascular events in later life. This emphasizes the importance of searching for other possible risk factors associated with diabetes. We investigated whether recurrent episodes of acute respiratory infections and exposure to tobacco smoke could influence vascular phenotypes for early atherosclerosis in children and adolescents with type 1 diabetes.Materials and methods  Common carotid artery elasticity and intima‐media thickness along with circulating markers of lipid, inflammatory and glycaemic profiles were investigated in up to 98 children and adolescents with type 1 diabetes. The number of clinically manifest acute respiratory tract infections (RTI) during the past year, and the degree of exposure to environmental tobacco smoke (ETS), were assessed by separate questionnaires.Results  Carotid artery compliance (CAC) was decreased in patients with high (≥ 4/year; n = 22) recurrence of RTI compared to the remaining patients (n = 40; P < 0·05). In a multivariate analysis, the number of RTI during the past year and HbA1C were independently associated with decreased CAC (P < 0·05 for both). The inverse relationship between RTI recurrence and CAC was strengthened by frequent exposure to ETS.Conclusions  High recurrence of respiratory infections in young type 1 diabetics is associated with increased stiffening of the carotid artery particularly in those often exposed to tobacco smoke.
Diet and dental erosion in young people in south‐east Brazil
Authors: WATERHOUSE PAULA J. , AUAD SHEYLA M. , NUNN JUNE H. , STEEN IAN N. , MOYNIHAN PAULA J. 
Published: April 2008

Background.  The regular consumption of acidic foods and drinks may be associated with dental erosion, and soft drink consumption appears to be increasing both in developed and developing countries. Dentists are aware that an acidic diet can contribute to the development of erosion; however, there may be confusion within the profession concerning the general health message of eating five portions of fruits and vegetables each day.Objective.  The aim of this study was to investigate associations between dental erosion and the consumption of acidic foods and beverages in schoolchildren in south‐east Brazil. The objective was to gather information, by means of a dietary questionnaire, on frequency of intake and patterns of consumption of acidic foods and drinks in a group of schoolchildren. The hypothesis was that the experience of dental erosion among the study sample was associated with the frequency and pattern of consumption of soft drinks, fruit juices, fruits, and yogurt.Methods.  A cross‐sectional study was conducted in Três Corações, south‐east Brazil. A sample of 458 schoolchildren, mean age 13.8 (SD 0.39) years, completed the study. Information about potential dietary risk factors for dental erosion was collected through a questionnaire survey completed by the schoolchildren. For the dental examinations, the subjects were examined for dental erosion in a school room. Associations between dental erosion and the variables under study were investigated through processes of bivariate and multivariate analyses. The statistical significance level was set at 5%.Results.  Analysis of the questionnaire surveys showed that the frequency of consumption of sugared carbonated drinks was the only variable independently associated with the erosive process, with subjects who had a daily consumption of such drinks having a greater likelihood of having erosion (P = 0.015, odds ratio 1.752, 95% confidence interval 1.116–2.750).Conclusions.  Of all tested factors in this sample of schoolchildren the consumption of sugared carbonated drinks is most associated with dental erosion.
ORIGINAL ARTICLE: Cycads in the insular South‐west Pacific: dispersal or vicariance?
Authors: Keppel Gunnar , Hodgskiss Paul D. , Plunkett Gregory M. 
Published: April 2008

AbstractAim  Cycads constitute an ancient plant group that is generally believed to disperse poorly. However, one group of cycads (subsection Rumphiae) is thought to have dispersed relatively recently from a Malesian source area westwards to East Africa and eastwards into the Pacific, using a floatation‐facilitating layer in their seeds. We use morphological and allozyme characters to investigate the relationships among the species within this group and to deduce whether the wide distribution was achieved by recent dispersal (as evidenced by high genetic similarity) or more distant vicariance events (high genetic differentiation).Location  We examined specimens collected throughout the range of subsection Rumphiae, from East Africa through Southeast Asia to Tonga in the South‐west Pacific.Methods  We investigated relationships within subsection Rumphiae of the genus Cycas by analysing 18 variable (11 informative) morphological characters and 22 allozyme loci for seven of the 10 species currently assigned to this taxon.Results  Distinctive morphological characters are few and fail to resolve relationships within the group. Allozyme data show that species within this subsection are closely related and suggest that there are two groups within the subsection, one comprising Cycas thouarsii (East Africa) and C. edentata (the Philippines), and the other the remaining species (from Malesia and the Pacific). The Australian species C. silvestris is sister to subsection Rumphiae in the morphological analysis but is closely allied to C. rumphii (nested within the subsection) in the allozyme analysis, suggesting that Rumphiae may be paraphyletic and that characters thought to be taxonomically important may need to be re‐evaluated.Main conclusions  Cycads within subsection Rumphiae are closely related, and the wide distribution of this group was probably achieved through relatively recent oceanic dispersal events. Separate events probably account for the dispersal of these cycads into the Pacific and to Africa. The origin and distribution of C. silvestris (Australia) could be explained by a dispersal event from New Guinea or may have resulted from a former land connection between Australia and New Guinea.
Multi‐scale determinants of dung beetle assemblage structure across abiotic gradients of the Kalahari–Nama Karoo ecotone, South Africa
Authors: Davis Adrian L.V. , Scholtz Clarke H. , Deschodt Christian 
Published: April 2008

AbstractAim Changing conditions across spatial gradients are primary determinants of biotic regions, local habitats, and distributional edges. We investigate how a climatic gradient and edaphic mosaic interact as multi‐scale drivers of spatial patterns in scarabaeine dung beetles. The patterns are tested for congruency with ecoregion and floral boundaries over the same gradient, as responses to physical factors often differ among higher taxa.Location Southern Africa and the Nama Karoo–Kalahari ecotone, Northern Cape, South Africa.Methods Data consisted of the climatic distributions of 104 species and their abundances at 223 sites in two ecoregions/floral biomes, four bioregions, and 13 vegetation units. Factor analyses determined the biogeographical composition of the species, and regional‐ to local‐scale patterns in species abundance structure. Hierarchical analysis of oblique factors determined the proportional contribution of spatial variance to patterns. One‐wayanovawas used to test for significant separation of patterns along factor axes. Stepwise multiple regression was used to determine correlations of five physical attributes with species richness, Shannon‐Wiener diversity, and factor loadings for the study sites.Results Four biogeographical influences overlap in the study region, although rank contribution declines from south‐west arid through north‐east savanna to widespread and south‐east highland taxa. Species abundance structure comprises five subregional patterns, two centred to the north‐east (Kalahari, Isolated Kalahari Dune) dominated by Kalahari influence, and three to the south‐west (Nama Karoo subdivisions: Bushmanland, ‘Upper’, ‘Stony Prieska’) dominated by south‐west arid influence. Kalahari deep sands are characterized especially by a warmer, moister climate, whereas the Nama Karoo mosaic of deep or stony soils is characterized especially by north‐west aridity (Bushmanland), south‐east cooler temperatures (‘Upper’), or excessively stony soils (‘Stony Prieska’). Four of the subregional patterns each comprised three localized patterns related primarily to relative stoniness, edge effects from geographical position, or incidence of rainfall. Species richness and diversity declined with decreasing rainfall and increasing stoniness.Main conclusions Climatic and edaphic factors are important multi‐scale determinants of spatial patterns in dung beetle assemblage structure, with edaphic factors becoming more important at local spatial scales. The patterns are roughly congruent with the Kalahari Savanna–Nama Karoo ecotone at the floral biome or ecoregion scale, but show limited coincidence with finer‐scale floral classification.
Constraint factor graph cut–based active contour method for automated cellular image segmentation in RNAi screening
Authors: CHEN C. , LI H. , ZHOU X. , WONG S. T. C. 
Published: April 2008

SummaryImage‐based, high throughput genome‐wide RNA interference (RNAi) experiments are increasingly carried out to facilitate the understanding of gene functions in intricate biological processes. Automated screening of such experiments generates a large number of images with great variations in image quality, which makes manual analysis unreasonably time‐consuming. Therefore, effective techniques for automatic image analysis are urgently needed, in which segmentation is one of the most important steps. This paper proposes a fully automatic method for cells segmentation in genome‐wide RNAi screening images. The method consists of two steps: nuclei and cytoplasm segmentation. Nuclei are extracted and labelled to initialize cytoplasm segmentation. Since the quality of RNAi image is rather poor, a novel scale‐adaptive steerable filter is designed to enhance the image in order to extract long and thin protrusions on the spiky cells. Then, constraint factor GCBAC method and morphological algorithms are combined to be an integrated method to segment tight clustered cells. Compared with the results obtained by using seeded watershed and the ground truth, that is, manual labelling results by experts in RNAi screening data, our method achieves higher accuracy. Compared with active contour methods, our method consumes much less time. The positive results indicate that the proposed method can be applied in automatic image analysis of multi‐channel image screening data.
Cluster identification in AA5754 aluminium sheets using mathematical morphology analysis
Authors: TEWARI A. , TIWARI S. , BISWAS P. , MISHRA R. K. 
Published: April 2008

SummaryQuantitative image analysis of particle distribution in the microstructure of continuous cast (CC) and direct chill cast (DC) AA5754 aluminium alloy sheets have been conducted. This information can be used as an input for modelling mechanical deformation and instability in these materials. The quantitative analysis reveals that there are significant differences in the microstructure of the two materials even though the total content of second‐phase particles is statistically similar. Qualitative observation shows the second‐phase particles to be arranged in the form of streaks parallel to the rolling direction in the CC sheets and in a uniform random manner in the DC sheets. The main difference in the geometric microstructure of the CC and DC material is the spatial arrangement of the second‐phase particles. A new mathematical technique called proximity analysis is developed to identify clusters and group of particles belonging to a cluster. Quantification through proximity analysis reveals that the particle clusters in CC sheet are in the form of long clusters (streaks) parallel to the rolling direction and are significantly longer than those in DC sheets (with the largest cluster in CC being four times larger than DC), and also have anisotropic angular orientation parallel to the rolling direction. The lower value of fracture strain observed in the CC sheets compared to DC sheets is attributed to a combination of large sizes of clusters and their preferential alignment along the rolling direction in the CC microstructure.
Correction for non‐perpendicularity of beam and tilt axis in tomographic reconstructions with the IMOD package
Authors: MASTRONARDE D. N. 
Published: April 2008

SummaryA correction for non‐perpendicularity between the beam axis and the tilt axis in electron tomographic tilt series has been implemented in the IMOD software package and its value and limitations have been explored. Correction for this effect can provide a significant improvement in the alignment error and the reconstruction quality in some cases. However, when the projection model being fit includes an anisotropic shrinkage (i.e. stretch) in the plane of the specimen, adding a variable for the beam tilt does not produce a lower alignment error; it is thus not possible to distinguish between the effects of stretch and beam tilt. Test reconstructions indicate that an alignment solution that includes stretch will adequately correct for the effects of a beam tilt. For specimens subject to deformation under the beam, an alignment solution that accounts for stretch is preferable to one that accounts for beam tilt instead, provided that the markers used for alignment are sufficiently well distributed. Otherwise, a correction for beam tilt should be used.
Atomic force microscopy to characterize the molecular size of prion protein
Authors: KUNZE S. , LEMKE K. , METZE J. , BLOUKAS G. , KOTTA K. , PANAGIOTIDIS C. H. , SKLAVIADIS T. , BODEMER W. 
Published: April 2008

SummaryThe conformational transition of α‐helix‐rich cellular prion protein (PrPC) to an isomer with high β‐sheet content is associated with transmissible spongiform encephalopathies. With the ultimate long‐term goal of using imaging techniques to study PrP aggregation, we report the results of initial experiments to determine whether PrP molecules could be visualized as single molecules, and if the observed size corresponded to the calculated size for PrP. The investigation of single molecules, and not those embedded into larger aggregates, was the key in our experimental approach. Using atomic force microscopy (AFM) as an imaging method, the immobilization of recombinant histidine (His)10‐tagged PrP on mica was performed in the presence of different heavy metal ions. The addition of Cu2+ resulted in an enhanced PrP immobilization, whereas Ni2+ reduced coverage of the surface by PrP. High‐resolution data from dried PrP preparations provided a first approximation to geometrical parameters of PrP precipitates, which indicated that the volume of a single PrP molecule was 30 nm3. Molecular dynamics simulations performed to complement the structural aspects of the AFM investigation yielded a calculated molecular volume of 33 nm3 for PrP. These experimentally observed and theoretically expected values provide basic knowledge for further studies on the size and composition of larger amyloidal PrP aggregates, PrP isoforms or mutants such as PrP molecules without octarepeats.
Evolution of residual stress and crack morphologies during 3D FIB tomographic analysis of alumina
Authors: ELFALLAGH F. , INKSON B. J. 
Published: April 2008

SummaryThree‐dimensional focused ion beam (FIB) tomography is increasingly being used for 3D characterization of microstructures in the 50 nm–20 μm range. FIB tomography is a destructive, invasive process, and microstructural changes may potentially occur during the analysis process. Here residual stress and crack morphologies in single‐crystal sapphire samples have been concurrently analyzed using Cr3+ fluorescence spectroscopy and FIB tomography. Specifically, maps of surface residual stress have been obtained from optically polished single‐crystal alumina [surface orientation (1 ī 0 2)], from FIB milled surface trenches, from Vickers micro‐indentation sites (loads 50 g–300 g), and from Vickers micro‐indentation sites during FIB serial sectioning. The residual stress maps clearly show that FIB sputtering generates residual stress changes. For the case of the Vickers micro‐indentations, FIB sputtering causes significant changes in residual stress during the FIB tomographic serial sectioning. 3D reconstruction of the crack distribution around micro‐indentation sites shows that the cracks observed are influenced by the location of the FIB milled surface trenches due to localized stress changes.
Pseudovacuoles – immobilized by high‐pressure freezing – are associated with blebbing in walker carcinosarcoma cells
Authors: VANHECKE D. , BELLMANN R. , BAUM O. , GRABER W. , EGGLI P. , KELLER H. , STUDER D. 
Published: April 2008

SummaryBy applying high pressure freezing and freeze‐substitution, we observed large inclusions of homogeneous appearance in the front of locomoting Walker carcinosarcoma cells that have not been described earlier. Live cell imaging revealed that these inclusions were poor in lipids and nucleic acids but had a high lysine (and hence protein) content. Usually one such structure 2–5 μm in size was present at the front of motile Walker cells, predominantly in the immediate vicinity of newly forming blebs. By correlating the lysine‐rich areas in fixed and embedded cells with electron microscopic pictures, inclusions could be assigned to confined, faintly stained cytoplasmic areas that lacked a surrounding membrane; they were therefore called pseudovacuoles. After high‐pressure freezing and freeze substitution, pseudovacuoles appeared to be filled with 20 nm large electron‐transparent patches surrounded by 12 and 15 nm large particles. The heat shock protein Hsp90 was identified by peptide sequencing as a major fluorescent band on SDS‐PAGE of lysine‐labelled Walker cell extracts. By immunofluorescence, Hsp90 was found to be enriched in pseudovacuoles. Colocalization of the lysine with a potassium‐specific dye in living cells revealed that pseudovacuoles act as K+ stores in the vicinity of forming blebs. We propose that pseudovacuoles might support blebbing by locally regulating the intracellular hydrostatic pressure.
Electron microscopy of the early Caenorhabditis elegans embryo
Authors: MÜLLER‐REICHERT T. , MÄNTLER J. , SRAYKO M. , O'TOOLE E. 
Published: April 2008

SummaryThe early Caenorhabditis elegans embryo is currently a popular model system to study centrosome assembly, kinetochore organization, spindle formation, and cellular polarization. Here, we present and review methods for routine electron microscopy and 3D analysis of the early C. elegans embryo. The first method uses laser‐induced chemical fixation to preserve the fine structure of isolated embryos. This approach takes advantage of time‐resolved fixation to arrest development at specific stages. The second method uses high‐pressure freezing of whole worms followed by freeze‐substitution (HPF‐FS) for ultrastructural analysis. This technique allows staging of developing early embryos within the worm uterus, and has the advantage of superior sample preservation required for high‐resolution 3D reconstruction. The third method uses a correlative approach to stage isolated, single embryos by light microscopy followed by HPF‐FS and electron tomography. This procedure combines the advantages of time‐resolved fixation and superior ultrastructural preservation by high‐pressure freezing and allows a higher throughput electron microscopic analysis. The advantages and disadvantages of these methods for different applications are discussed.
Controlled microaspiration for high‐pressure freezing: a new method for ultrastructural preservation of fragile and sparse tissues for TEM and electron tomography
Authors: TRIFFO W. J. , PALSDOTTIR H. , McDONALD K. L. , LEE J. K. , INMAN J. L. , BISSELL M. J. , RAPHAEL R. M. , AUER M. 
Published: April 2008

SummaryHigh‐pressure freezing is the preferred method to prepare thick biological specimens for ultrastructural studies. However, the advantages obtained by this method often prove unattainable for samples that are difficult to handle during the freezing and substitution protocols. Delicate and sparse samples are difficult to manipulate and maintain intact throughout the sequence of freezing, infiltration, embedding and final orientation for sectioning and subsequent transmission electron microscopy. An established approach to surmount these difficulties is the use of cellulose microdialysis tubing to transport the sample. With an inner diameter of 200 μm, the tubing protects small and fragile samples within the thickness constraints of high‐pressure freezing, and the tube ends can be sealed to avoid loss of sample. Importantly, the transparency of the tubing allows optical study of the specimen at different steps in the process. Here, we describe the use of a micromanipulator and microinjection apparatus to handle and position delicate specimens within the tubing. We report two biologically significant examples that benefit from this approach, 3D cultures of mammary epithelial cells and cochlear outer hair cells. We illustrate the potential for correlative light and electron microscopy as well as electron tomography.