bluuebunny/crossref_metadata_2025_split huggingface dataset:
Induction of CD4 T cell proliferation andin vitroTh1-like cytokine responses to measles virus
Authors: Howe R C , Dhiman N , Ovsyannikova I G , Poland G A 
Published: March 2005

SummaryMechanisms that lead to induction of life-long immunity to measles virus (MV) are poorly understood. In the present study, we have assessed the activation, proliferation and cytokine secreting function of peripheral blood T cells from MV immune individuals. Expression of cell blastogenesis markers, such as increased forward light scatter and CD38 expression, peaked 5–7 days after infection of peripheral blood mononuclear cells (PBMC) with the live attenuated Edmonston strain of MV. Subset analysis revealed that both CD3– and CD3+ cells expressed activation markers but that the CD3+ T cells predominated late in the culture period corresponding to maximal proliferation and cell recovery. The majority of CD3+ T cells consisted of CD4+CD8– cells. IFN-γ and IL-4 production similarly showed optimal production late in culture. Depletion of CD4 cells prior to culture and MV stimulation completely abrogated both IFN-γ and IL-4 production, whereas depletion of CD8 cells did not diminish production, suggesting that CD4+CD8– T cells were principally involved in production of these cytokines. Finally, optimal IFN-γ production was elicited at high MV doses and IL-4 at much lower doses. These results suggest that among MV immune individuals, in vitro responses to measles are dominated by CD4+ T cells that, depending on antigen dose, primarily produce a Th1-like and, to a lesser extent, a Th1/Th2-mixed pattern of cytokine release.
Dichotomy of protective cellular immune responses to human visceral leishmaniasis
Authors: Khalil E A G , Ayed N B , Musa A M , Ibrahim M E , Mukhtar M M , Zijlstra E E , Elhassan I M , Smith P G , Kieny P M , Ghalib H W , Zicker F , Modabber F , Elhassan A M 
Published: March 2005

Summary
Healing/protective responses in human visceral leishmaniasis (VL) are associated  with  stimulation/production  of  Th1  cytokines,  such  as  interferon IFN-γ, and conversion in the leishmanin skin test (LST). Such responses were studied for 90 days in 44 adult healthy volunteers from VL non-endemic areas, with no past history of VL/cutaneous leishmaniasis (CL) and LST non-reactivity following injection with one of four doses of Alum-precipitated autoclaved Leishmania major (Alum/ALM) ± bacille Calmette–Guérin (BCG), a VL candidate vaccine. The vaccine was well tolerated with minimal localized side-effects and without an increase in antileishmanial antibodies or interleukin (IL)-5. Five volunteers (5/44; 11·4%) had significant IFN-γ production by peripheral blood mononuclear cells (PBMCs) in response to Leishmania antigens in their prevaccination samples (P = 0·001) but were LST non-reactive. On day 45, more than half the volunteers (26/44; 59·0%) had significantly high LST indurations (mean 9·2 ± 2·7 mm) and high IFN-γ levels (mean 1008 ± 395; median 1247 pg/ml). Five volunteers had significant L. donovani antigen-induced IFN-γ production (mean 873 ± 290; median 902; P = 0·001), but were non-reactive in LST. An additional five volunteers (5/44; 11·4%) had low IFN-γ levels (mean 110 ± 124 pg/ml; median 80) and were non-reactive in LST (induration = 00 mm). The remaining eight volunteers had low IFN-γ levels, but significant LST induration (mean 10 ± 2·9 mm; median 11). By day 90 the majority of volunteers (27/44; 61·4%) had significant LST induration (mean 10·8 ± 9·9 mm; P &lt; 0·001), but low levels of L. donovani antigen-induced IFN-γ (mean 66·0 ± 62 pg/ml; P &gt; 0.05). Eleven volunteers (11/44; 25%) had significantly high levels of IFN-γ and LST induration, while five volunteers had low levels of IFN-γ (&lt;100 pg/ml) and no LST reactivity (00 mm). One volunteer was lost to follow-up. In conclusion, it is hypothesized that cellular immune responses to human VL are dichotomatous, and that IFN-γ production and the LST response are not in a causal relationship. Following vaccination and probably cure of VL infection, the IFN-γ response declines with time while the LST response persists. LST is a simple test that can be used to assess candidate vaccine efficacy.
Neutrophil chemokines in epithelial inflammatory processes of human tonsils
Authors: Sachse F , Ahlers F , Stoll W , Rudack C 
Published: March 2005

SummaryCXC chemokines are thought to play an important role at sites of inflammation. Because ELR+ CXC chemokines are expressed in different types of tonsillitis we investigated the role of the surface/crypt epithelium of human tonsils  in  producing  ELR+  CXC  chemokines:  interleukin  (IL)-8  (CXCL8), ENA-78 (CXCL5), GRO-α (CXCL1) and GCP-2 (CXCL6). Tonsillar tissue was obtained from patients undergoing tonsillectomy and chemokine expression was investigated by means of immunohistochemistry. A549 cells were used as a model to study kinetics of chemokine expression in epithelial cells. Cells were stimulated with tumour necrosis factor (TNF)-α, lipopolysaccharide (LPS) and supernatants derived from aerobic/anaerobic Staphylococcus aureus strains. Chemokine expression was measured by quantitative reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). We observed epithelial expression of IL-8, GRO-α and GCP-2 in different types of tonsillitis, whereas ENA-78 was rarely expressed. In A549 cells abundant expression of ENA-78 was detected. IL-8 and GCP-2 are expressed in an acute type of tonsillitis whereas GRO-α was frequently detectable both in chronically and acutely inflamed tonsils. ENA-78 does not seem to play a pivotal role in tonsillitis in vivo.
Different natural killer (NK) receptor expression and immunoglobulin E (IgE) regulation by NK1 and NK2 cells
Authors: Aktas E , Akdis M , Bilgic S , Disch R , Falk C S , Blaser K , Akdis C , Deniz G 
Published: March 2005

SummaryMany studies concerning the role of T cells and cytokines in allergy have been performed, but little is known about the role of natural killer (NK) cells. Accordingly, the expression of co-stimulatory, inhibitory and apoptosis receptors, cytokine profiles and their effect on immunoglobulin isotypes were investigated in polyallergic atopic dermatitis (AD) patients with hyper immunoglobulin E (IgE) and healthy individuals. AD patients showed significantly decreased peripheral blood NK cells compared to healthy individuals. Freshly isolated NK cells of polyallergic patients spontaneously released higher amounts of interleukin (IL)-4, IL-5, IL-13 and interferon (IFN)-γ compared to healthy individuals. NK cells were differentiated to NK1 cells by IL-12 and neutralizing anti-IL-4 monoclonal antibodies (mAb), and to NK2 cells by IL-4 and neutralizing anti-IL-12 mAb. Following IL-12 stimulation, NK cells produced increased levels of IFN-γ and decreased IL-4. In contrast, stimulation of NK cells with IL-4 inhibited IFN-γ, but increased IL-13, production. The effect of NK cell subsets on IgE regulation was examined in co-cultures of in vitro differentiated  NK  cells  with  peripheral  blood  mononuclear  cells  (PBMC) or B cells. NK1 cells significantly inhibited IL-4- and soluble CD40-ligand-stimulated IgE production; however, NK2 cells did not have any effect. The inhibitory effect of NK1 cells on IgE production was blocked by neutralization of IFN-γ. Except for CD40, NK cell subsets showed different expression of killer-inhibitory receptors and co-stimulatory molecules between the polyallergic and healthy subjects. These results indicate that human NK cells show differences in numbers, surface receptor and cytokine phenotypes and functional properties in AD.
Simultaneous degradation estimation and restoration of confocal images and performance evaluation by colocalization analysis
Authors: ROOMS F. , PHILIPS W. , LIDKE D. S. 
Published: March 2005

SummaryA novel method for joint restoration and estimation of the degradation of confocal microscope images is presented. The observed images are degraded due to two sources: blurring due to the band‐limited nature of the optical system [modelled by the point spread function (PSF)], and Poisson noise contaminates the observations due to the discrete nature of the photon detection process. The proposed method iterates noise reduction, blur estimation and deblurring, and applies these steps in two phases, i.e. a training phase and a restoration phase. In the first phase, these three steps are iterated until the blur estimation converges. Noise reduction and blur estimation are performed using steerable pyramids, and the deblurring is performed by the Richardson–Lucy algorithm. The second phase is the actual restoration. From then on, the blur estimation is used as a criterion to measure the image quality. The iterations are stopped when this measure converges, a result that is guaranteed. The integrated method is completely automatic, and no prior information on the image is required. The method has been given the name SPERRIL (Steerable Pyramid‐based Estimation and Regularized Richardson–Lucy restoration). Compared with existing techniques by both objective measures and visual observation, in the SPERRIL‐restored images noise is better suppressed.
A fast method to study the secretory activity of neuroendocrine cells at the ultrastructural level
Authors: VAN HERP F. , COENEN T. , GEURTS H. P. M. , JANSSEN G. J. A. , MARTENS G. J. M. 
Published: March 2005

SummaryCryo field emission scanning electron microscopy (cryo‐FE‐SEM) is a versatile technique that allows the investigation of the three‐dimensional organization of cells at the ultrastructural level over a wide range of magnifications. Unfortunately, cryopreparation of the specimens for this technique remains cumbersome, in particular because ice crystal formation must be prevented during freezing. Here we report that a light prefixation with glutaraldehyde and incubation in glycerol as cryoprotectant or a high‐pressure freezing approach are both excellent procedures for cryopreparation of animal cells to be used in combination with cryo‐FE‐SEM. Using the proopiomelanocortin‐producing intermediate pituitary melanotrope cells of Xenopus laevis as a physiologically inducible neuroendocrine system, we compared the ultrastructural characteristics of inactive and hyperactive neuroendocrine cells. The overall quality of the ultrastructural images was comparable for the two cryopreparation procedures, although some fine structures were better conserved using high‐pressure freezing. Melanotrope cells in a secretory inactive state contained numerous storage granules and a poorly developed endoplasmic reticulum (ER), while large amounts of rough ER were present in hyperactive cells. Thus, the cryo‐FE‐SEM approach described here allows a fast ultrastructural study on the secretory activity of neuroendocrine cells.
A procedure to determine the correct thickness of an object with confocal microscopy in case of refractive index mismatch
Authors: KUYPERS L. C. , DECRAEMER W. F. , DIRCKX J. J. J. , TIMMERMANS J.‐P. 
Published: March 2005

SummaryA difference in refractive index (n) between immersion medium and specimen results in increasing loss of intensity and resolution with increasing focal depth and in an incorrect axial scaling in images of a confocal microscope. Axial thickness measurements of an object on such images are therefore not exact. The present paper describes a simple procedure to determine the correct axial thickness of an object with confocal fluorescence microscopy. We study this procedure for a specimen that has a higher refractive index than the immersion medium and with a thickness up to 100 µm. The measuring method was experimentally tested by comparing the thickness of polymer layers measured on axial images of a confocal microscope in case of a water–polymer mismatch to reference values obtained from an independent technique, i.e. scanning electron microscopy. The case when the specimen has a lower refractive index than the immersion medium is also shown by way of illustration. Measured thickness data of a water layer and an oil layer with the same actual thickness were obtained using an oil‐immersion objective lens with confocal microscopy. Good agreement between theory and experiment was found in both cases, consolidating our method.
Comparative imaging of a bacterial surface‐located GFP fusion protein by epifluorescence and scanning near‐field optical microscopy
Authors: GUNNING A. P. , BONGAERTS R. J. M. , KIRBY A. R. , HINTON J. C. D. , MORRIS V. J. 
Published: March 2005

SummaryIcsA is an autotransporter protein that plays a role in the virulence of Shigella bacteria. We have examined the cellular localization of a fusion of an IcsA fragment to the green fluorescent protein (GFP) expressed in Escherichia coli using a dual epifluorescence and scanning near‐field optical microscope. By combining the data obtained from far‐field with near‐field microscopy of the same sample, discrimination between surface‐bound fusion proteins and fusion proteins located in the cellular cytoplasm becomes possible. Furthermore, and for the first time, the inherent advantages in resolution of the near‐field images provides highly specific details of the location of a GFP fusion protein on a bacterial cell surface.
Reconstruct: a free editor for serial section microscopy
Authors: FIALA J. C. 
Published: March 2005

SummaryMany microscopy studies require reconstruction from serial sections, a method of analysis that is sometimes difficult and time‐consuming. When each section is cut, mounted and imaged separately, section images must be montaged and realigned to accurately analyse and visualize the three‐dimensional (3D) structure. Reconstruct is a free editor designed to facilitate montaging, alignment, analysis and visualization of serial sections. The methods used by Reconstruct for organizing, transforming and displaying data enable the analysis of series with large numbers of sections and images over a large range of magnifications by making efficient use of computer memory. Alignments can correct for some types of non‐linear deformations, including cracks and folds, as often encountered in serial electron microscopy. A large number of different structures can be easily traced and placed together in a single 3D scene that can be animated or saved. As a flexible editor, Reconstruct can reduce the time and resources expended for serial section studies and allows a larger tissue volume to be analysed more quickly.
Microfabric analysis by manual and automated stereological procedures: a methodological approach to Antarctic tillite
Authors: STROEVEN ARJEN P. , STROEVEN PIET , VAN DER MEER JAAP J. M. 
Published: March 2005

AbstractFabric analysis is commonly used to infer former movement directions of diamictons; however, analysis techniques are typically time consuming and partly subjective. Stereological analysis provides an alternative for objective determination of the preferred orientation of particles. The ability of manual and automated stereological procedures to determine the preferred orientation of particles (120–4000 µm) in tillite is assessed, using core samples from Mount Feather, McMurdo Dry Valleys, Antarctica. Orthogonal sets of vertical thin sections were subjected to directed secant analysis involving the determination of the number of intersections between particle outlines and a rotating series of parallel lines. The manual analysis reveals a weakly developed three‐dimensional tilt angle (plunge) of 68°. This reflects the depth‐averaged subglacial deformational structure of the deposit. Because the preferred orientation signal is weak, in the automated set‐up this signal is obscured by the effect of digitization, hampering the reliable assessment of the orientation direction. The study shows microfabric variability within the studied cored section that is interpreted as a shear fabric. Reliable macrostructural information that might constrain ice flow directions requires a larger number of randomly or systematically drawn core samples from which averaged microstructural fabrics can be derived.
Mass movement‐induced fold‐and‐thrust belt structures in unconsolidated sediments in Lake Lucerne (Switzerland)
Authors: SCHNELLMANN MICHAEL , ANSELMETTI FLAVIO S. , GIARDINI DOMENICO , McKENZIE JUDITH A. 
Published: March 2005

AbstractHigh‐resolution seismic imaging and piston coring in Lake Lucerne, Switzerland, have revealed surprising deformation structures in flat‐lying, unconsolidated sediment at the foot of subaqueous slopes. These deformation structures appear beneath wedges of massflow deposits and resemble fold‐and‐thrust belts with basal décollement surfaces. The deformation is interpreted as the result of gravity spreading induced by loading of the slope‐adjacent lake floor during massflow deposition. This study investigated four earthquake‐triggered lateral mass‐movement deposits in Lake Lucerne affecting four sections of the lake floor with areas ranging from 0·25 to 6·5 km2 in area. Up to 6 m thick sediment packages draping the subaqueous slopes slid along the acoustic basement. The resulting failure scars typically lie in water depths of >30 m on slopes characterized by downward steepening and inclinations of >10°. From the base‐of‐slope to several hundred metres out onto the flat plains, the wedges of massflow deposits overlie deeply (10–20 m) deformed basin‐plain sediment characterized by soft sediment fold‐and‐thrust belts with arcuate strikes and pronounced frontal thrusts. The intensity of deformation decreases towards the more external parts of the massflow wedges. Beyond the frontal thrust, the overridden lake floor remains mostly undisturbed. Geometrical relationships between massflow deposits and the deformed basin‐plain sediment indicate that deformation occurred mainly during massflow deposition. Gravity spreading induced by the successive collapse of the growing slope‐adjacent massflow wedge is proposed as the driving mechanism for the deformation. The geometry of fjord‐type lakes with sharp lower slope breaks favours the deposition of thick, basin‐marginal massflow wedges, that effectively load and deform the underlying sediment. In the centre of the basins, the two largest massflow deposits described are directly overlain by thick contained (mega‐)turbidites, interpreted as combined products of the suspension clouds set up by subaqueous mass movements and related tsunami and seiche waves.
Estimating palaeobathymetry of wave‐graded continental shelves from sediment texture
Authors: DUNBAR G. B. , BARRETT P. J. 
Published: March 2005

AbstractThe concept of the wave‐graded continental shelf, with sea floor sediment coarsening from offshore mud to shoreface sand, has been well known from the time of Johnson (1919). Although most of the modern shelf shows textures unrelated to water depth on account of relict features or sediment starvation, the geological record is more likely to preserve sites where sediment is being fed to a subsiding inner‐shelf. These consistently show the landward‐coarsening pattern of the wave‐graded shelf, recording past water depth history in accumulated sea floor sediment. The landward‐coarsening pattern is driven primarily by wave‐induced bed shear stress, which increases shoreward exponentially, although it also varies from place to place with wave climate, and can be influenced by sediment concentration and currents. In this study, the relationship between bed shear stress, sediment texture and water depth has been investigated by comparing per cent mud and wave climate data from shore‐normal transects of three modern wave‐graded coastal settings: Wellington Harbour (low energy) and the Manawatu coast (moderate energy) in New Zealand, and Monterey Bay in California (moderate–high energy). Samples from all three locations show a progressive change from poorly sorted mud offshore to well‐sorted fine sand nearshore, with the sand–mud transition ranging from 3 m (low energy) to 50 m (moderate–high energy), reflecting differences in average bed shear. Repeat measurements of per cent mud on seasonal, annual and decadal time scales along a Manawatu coastal transect showed no measurable change, demonstrating equilibrium between sediment supply, wave energy, water depth and sediment texture. A simple model based on the relationship between wave climate, shear stress and per cent mud, and using data and conditions from the modern Manawatu coast, is applied to two mid‐Pliocene cyclothems exposed 50 km inland, giving results comparable with estimates from foraminifera and the deep‐sea isotope record. Per cent mud offers more detail for palaeobathymetric trends in shallow water shelf strata than other proxy depth recorders, although it is limited to depths above wave base and requires an independent estimate of wave climate if depths are to be quantified.
Normal faulting as a control on the stratigraphic development of shallow marine syn‐rift sequences: the Nukhul and Lower Rudeis Formations, Hammam Faraun fault block, Suez Rift, Egypt
Authors: JACKSON C. A. L. , GAWTHORPE R. L. , CARR I. D. , SHARP I. R. 
Published: March 2005

AbstractTectono‐stratigraphic analysis of the East Tanka fault zone (ETFZ), Suez Rift, indicates that the evolution of normal fault segments was an important control on syn‐rift depositional patterns and sequence stratigraphy. Sedimentological and stratigraphic analysis of the Nukhul Formation indicates that it was deposited in a narrow (ca 1–2 km), elongate (ca 5 km), fault‐bounded, tidally influenced embayment during the low subsidence rift‐initiation phase. The Nukhul Formation is composed of transgressive (TST) and highstand (HST) systems tract couplets interpreted as reflecting fault‐driven subsidence and the continuous creation of accommodation in the hangingwall to the ETFZ. The overlying Lower Rudeis Formation was deposited during the high subsidence rift‐climax phase, and is composed of forced regressive systems tract (FRST) shallow marine sandbodies, and TST to HST offshore mudstones. Activity on the ETFZ led to marked spatial variability in stratal stacking patterns, systems tracts and key stratal surfaces, as footwall uplift, coupled with regressive marine erosion during deposition of FRST sandbodies, led to the removal of intervening TST–HST mudstone‐dominated units, and the amalgamation of FRST sandbodies and the stratal surfaces bounding these units in the footwall. This study indicates that the evolution of normal fault segments over relatively short (i.e. <1 km) length‐scales has the potential to enhance or suppress a eustatic sea‐level signal, leading to marked spatial variations in stratal stacking patterns, systems tracts and key stratal surfaces. Crucially, these variations in sequence stratigraphic evolution may occur within time‐equivalent stratal units, thus caution must be exercised when attempting to correlate syn‐rift depositional units based solely on stratal stacking patterns. Furthermore, local, tectonically controlled variations in relative sea level can give rise to syn‐rift stacking patterns which are counterintuitive in the context of the structural setting and perceived regional subsidence rates.