bluuebunny/crossref_metadata_2025_split huggingface dataset:
BPI–ANCA in transporter associated with antigen presentation (TAP) deficiency: possible role in susceptibility to Gram-negative bacterial infections
Authors: SCHULTZ H , SCHINKE S , WEISS J , CERUNDOLO V , GROSS W L , GADOLA S 
Published: July 2003

SUMMARYAlthough HLA class I expression is diminished in patients with defects in the transporter associated with antigen presentation (TAP), recurrent Gram-negative bacterial lung infections are found from childhood onwards. As MHC class II-mediated responses are normal, other mechanisms that contribute to susceptibility to infections are presumed. The bactericidal/permeability-increasing protein (BPI) is a potent neutrophil antibiotic that neutralizes endotoxin efficiently. As antineutrophil cytoplasmic autoantibodies (ANCA) against BPI were found in the majority of cystic fibrosis patients and correlate with disease severity we examined the prevalence of BPI–ANCA and their contribution to susceptibility to bacterial infections in six TAP-deficient patients. Although only two patients showed ANCA in indirect immunofluorescence, BPI–ANCA occurred in five of six patients in ELISA. Purified IgG from BPI–ANCA-positive sera (five of six) inhibited the antimicrobial function of BPI in vitro. Epitope mapping revealed binding sites not only on the C-terminal but also on the antibiotic N-terminal portion of BPI, indicating that short linear BPI peptide fragments may be long-lived enough to become immunogens. In conclusion, BPI–ANCA are associated strongly with TAP deficiency. Inhibition of the antimicrobial BPI function by BPI–ANCA demonstrates a possible mechanism of how autoantibodies may contribute to increased susceptibility for pulmonary Gram-negative bacterial infections by diminished bacterial clearance.
Cytokine profile, HLA restriction and TCR sequence analysis of human CD4+ T clones specific for an immunodominant epitope of Mycobacterium tuberculosis 16-kDa protein
Authors: CACCAMO N , BARERA A , DI SANO C , MERAVIGLIA S , IVANYI J , HUDECZ F , BOSZE S , DIELI F , SALERNO A 
Published: July 2003

SUMMARY
The identification of immunodominant and universal mycobacterial peptides could be applied to vaccine design and have an employment as diagnostic reagents. In this paper we have investigated the fine specificity, clonal composition and HLA class II restriction of CD4+ T cell clones specific for an immunodominant epitope spanning amino acids 91–110 of the 16-kDa protein of Mycobacterium tuberculosis. Twenty-one of the tested 28 clones had a Th1 profile, while seven clones had a Th0 profile. None of the clones had a Th2 profile. While the TCR AV gene usage of the clones was heterogeneous, a dominant TCR BV2 gene family was used by 18 of the 28 clones. The CDR3 regions of BV2+ T cell clones showed variation in lengths, but a putative common motif R-L/V-G/S-Y/W-E/D was detected in 13 of the 18 clones. Moreover, the last two to three residues of the putative CDR3 loops, encoded by conserved BJ sequences, could also play a role in peptide recognition. Antibody blockade and fine restriction analysis using HLA-DR homozygous antigen-presenting cells established that 16 of 18 BV2+ peptide-specific clones were DR restricted and two clones were DR-DQ and DR-DP restricted. Additionally, five of the 18 TCRBV2+ clones recognized peptide 91–110 in association with both parental and diverse HLA-DR molecules, indicating their promiscuous recognition pattern. The ability of peptide 91–110 to bind a wide range of HLA-DR molecules, and to stimulate a Th1-type interferon (IFN)-γ response more readily, encourage the use of this peptide as a subunit vaccine component.
Non-enveloped HCV core protein as constitutive antigen of cold-precipitable immune complexes in type II mixed cryoglobulinaemia
Authors: SANSONNO D , LAULETTA G , NISI L , GATTI P , PESOLA F , PANSINI N , DAMMACCO F 
Published: July 2003

SUMMARYHepatitis C virus (HCV) infection has been detected in a large proportion of patients with mixed cryoglobulinaemia (MC). Circulating ‘free’ non-enveloped HCV core protein has been demonstrated in HCV-infected patients, and this suggests its possible involvement in the formation of cryoprecipitable immune complexes (ICs). Thirty-two anti-HCV, HCV RNA-positive patients with type II MC were evaluated. Non-enveloped HCV core protein, HCV RNA sequences, total IgM, rheumatoid factor (RF) activity, IgG and IgG subclasses, C3 and C4 fractions, C1q protein and C1q binding activity were assessed in both cryoprecipitates and supernatants. Non-enveloped HCV core protein was demonstrated in 30 of 32 (93·7%) type II MC patients. After separation of cold-precipitable material, the protein was removed completely from supernatant in 12 patients (40%), whereas it was enriched in the cryoprecipitates of the remaining 18. In addition, HCV RNA and IgM molecules with RF activity were concentrated selectively in the cryoprecipitates. Differential precipitation was found for both total IgG and IgG subclasses, as they were less represented in the cryoglobulins and no selective enrichment was noted. Immunological characterization of HCV core protein-containing cryoprecipitating ICs after chromatographic fractionation showed that the IgM monoclonal component had RF activity, whereas anti-HCV core reactivity was confined to the IgG fraction. C1q enrichment in addition to high avidity of ICs for C1q binding in the cryoprecipitates suggest that complement activation may occur through the C1q protein pathway. The present data demonstrate that non-enveloped HCV core protein is a constitutive component of cryoprecipitable ICs in type II MC patients.
Immune biology of macaque lymphocyte populations during mycobacterial infection
Authors: LAI X , SHEN Y , ZHOU D , SEHGAL P , SHEN L , SIMON M , QIU L , LETVIN N L , CHEN Z W 
Published: July 2003

SUMMARYImmune responses of lymphocyte populations during early phases of mycobacterial infection and reinfection have not been well characterized in humans. A non-human primate model of Mycobacterium bovis bacille Calmette–Guerin (BCG) infection was employed to characterize optimally the immune responses of mycobacteria-specific T cells. Primary BCG infection induced biphasic immune responses, characterized by initial lymphocytopenia and subsequent expansion of CD4+, CD8+ and γδ T cell populations in the blood, lymph nodes and the pulmonary compartment. The potency of detectable T cell immune responses appears to be influenced by the timing and route of infection as well as challenge doses of BCG organisms. Systemic BCG infection introduced by intravenous challenge induced a dose-dependent expansion of circulating CD4+, CD8+ and γδ T cells whereas, in the pulmonary compartment, the systemic infection resulted in a predominant increase in numbers of γδ T cells. In contrast, pulmonary exposure to BCG through the bronchial route induced detectable expansions of CD4+, CD8+ and γδ T cell populations in only the lung but not in the blood. A rapid recall expansion of these T cell populations was seen in the macaques reinfected intravenously and bronchially with BCG. The expanded αβ and γδ T cell populations exhibited their antigen specificity for mycobacterial peptides and non-peptide phospholigands, respectively. Finally, the major expansion of T cells was associated with a resolution of active BCG infection and reinfection. The patterns and kinetics of CD4+, CD8+ and γδ T cell immune responses during BCG infection might contribute to characterizing immune protection against tuberculosis and testing new tuberculosis vaccines in primates.
Induction of mucosal tolerance with recombinant Hev b 1 and recombinant Hev b 3 for prevention of latex allergy in BALB/c mice
Authors: HUFNAGL K , WAGNER B , WINKLER B , BAIER K , HOCHREITER R , THALHAMER J , KRAFT D , SCHEINER O , BREITENEDER H , WIEDERMANN U 
Published: July 2003

SUMMARYThe prevalence of type I allergy to Hevea brasiliensis latex is particularly high among individuals with frequent exposure to latex products, such as health-care workers (HCW) and patients with spina bifida (SB). Treatment of latex allergy seems problematic as preventive measures, such as allergen avoidance, are not always possible and conventional immunotherapy with standardized latex extracts is not performed routinely. Thus, the aim of the present study was to establish a mouse model of latex allergy using two major latex allergens for HCWs and SB patients, Hev b 1 and Hev b 3, for sensitization. Prophylactic measures on the basis of mucosal tolerance induction with the recombinant allergens were tested in this model. Female BALB/c mice immunized intraperitoneally with recombinant (r)Hev b 1 or rHev b 3 displayed strong immune responses in vivo and in vitro. Intranasal treatment with rHev b 1 and rHev b 3 prior to sensitization led to reduced allergen-specific IgG1/IgE levels and significantly suppressed allergen-induced basophil degranulation. Moreover, lymphocyte proliferation and cytokine production (IL-4, IL-5, IFN-γ) in vitro were significantly suppressed after pretreatment with both allergens. Suppressive cytokines, such as interleukin (IL)-10 and transforming growth factor (TGF)-β, remained unchanged after the intranasal pretreatment, indicating mechanism of anergy rather than active immunosuppression. Taken together, these results suggest that mucosal tolerance induction with recombinant allergens could present a promising prevention strategy against latex allergy.
Evidence of expression of endotoxin receptors CD14, toll-like receptors TLR4 and TLR2 and associated molecule MD-2 and of sensitivity to endotoxin (LPS) in islet beta cells
Authors: VIVES-PI M , SOMOZA N , FERNÁNDEZ-ALVAREZ J , VARGAS F , CARO P , ALBA A , GOMIS R , LABETA M O , PUJOL-BORRELL R 
Published: July 2003

SUMMARYCD14, a GPI-linked membrane protein, is a component of the lipopolysaccharide (LPS) receptor complex, one of the pattern-recognizing receptors (PRR) expressed by myeloid lineage cells. Here we report that CD14, the functionally linked toll-like receptor molecules, TLR2 and TLR4, and the associated molecule MD-2 are expressed in endocrine cells of the human pancreatic islets. CD14 expression in human pancreatic islets was determined by immunofluorescence staining of tissue sections and primary cultures, and confirmed by flow cytometry of dispersed normal islets and SV40-transformed islet cells (HP62). The latter cells synthesized and secreted CD14 in response to lipopolysaccharide (LPS) in a time- and dose-dependent manner. Reverse transcription polymerase chain reaction (RT-PCR)-Southern was positive for CD14, TLR2, TLR4 and MD-2 in human pancreas, purified islets and HP62 cells. In vitro experiments using rat islets (also positive for CD14 by RT-PCR) and HP62 cells showed that LPS regulates glucose-dependent insulin secretion and induces inflammatory cytokines [interleukin (IL)-1α, IL-6 and tumour necrosis factor (TNF)-α]. The functional expression of CD14 and associated molecules in islet β cells adds a new pathway that islet cells may follow to adjust their function to endotoxaemia situations and become vulnerable to the inflammatory events that occur during diabetogenic insulitis.
Normal human IgG prevents endothelial cell activation induced by TNFα and oxidized low-density lipoprotein atherogenic stimuli
Authors: RONDA N , BERNINI F , GIACOSA R , GATTI R , BALDINI N , BUZIO C , ORLANDINI G 
Published: July 2003

SUMMARY
Normal human immunoglobulin G (IgG) has anti-inflammatory and immuno-regulatory properties, which are exploited in the therapy of selected diseases. A putative mechanisms of action is the direct regulation of endothelial cell function by natural antiendothelial cell antibodies. Endothelium activation is a critical event in atherosclerosis. We have verified the ability of normal human IgG to modulate endothelial responses to the atherogenic stimuli tumour necrosis factor-α (TNFα) and oxidized low-density lipoproteins (oxLDL) in vitro. Confocal microscopy was used to visualize vascular cell adhesion molecule-1 (CD106) expression on endothelial cells, cytoplasmic free calcium ([Ca++]i) modifications and fluorescein-coupled oxLDL internalization. Cytokine secretion was measured by ELISA on cell supernatants. IgG prevented TNFα induced CD106 membrane expression and an increase in [Ca++]i, and inhibited the secretion of interleukin-6 (IL-6) and macrophage-colony-stimulating factor (M-CSF). IgG also inhibited CD106 expression induced by oxLDL and one pathway of their internalization, but were ineffective on oxLDL induced [Ca++]i rise and apoptosis. F(ab)′2 fragments from IgG, but not monoclonal IgG, reproduce IgG effects. These findings point to a regulatory role for specific antibodies included in circulating normal IgG towards proinflammatory responses of endothelial cells in atherogenesis and suggest possible development of new therapeutic strategies.
Relative influence of variables at multiple spatial scales on stream macroinvertebrates in the Northern Lakes and Forest ecoregion, U.S.A.
Authors: Weigel Brian M. , Wang Lizhu , Rasmussen Paul W. , Butcher Jason T. , Stewart Paul M. , Simon Thomas P. , Wiley Michael J. 
Published: July 2003

Summary

We used 94 sites within the Northern Lakes and Forests ecoregion spanning Minnesota, Wisconsin and Michigan to identify environmental variables at the catchment, reach and riparian scales that influence stream macroinvertebrates. Redundancy analyses (RDA) found significantly influential variables within each scale and compared their relative importance in structuring macroinvertebrate assemblages.
Environmental variables included landcover, geology and groundwater delivery estimates at the catchment scale, water chemistry, channel morphology and stream habitat at the reach scale, and landcover influences at three distances perpendicular to the stream at the riparian scale. Macroinvertebrate responses were characterised with 22 assemblage attributes, and the relative abundance and presence/absence of 66 taxa.
Each scale defined macroinvertebrates along an erosional to depositional gradient. Wisconsin's macroinvertebrate index of biotic integrity, Ephemeroptera–Plecoptera–Trichoptera taxa and erosional taxa corresponded with forest streams, whereas organic pollution tolerant, Chironomidae and depositional taxa corresponded with wetland streams. Reach scale analyses defined the gradient similarly as dissolved oxygen and wide, shallow channels (erosional) opposed instream macrophytes and pool habitats (depositional). Riparian forests within 30 m of the stream coincided with an erosional assemblage and biotic integrity.
Next, we combined all significant environmental variables across scales to compare the relative influence of each spatial scale on macroinvertebrates. Partial RDA procedures described how much of the explained variance was attributable to each spatial scale and each interrelated scale combination.
Our results appeared consistent with the concept of hierarchical functioning of scale in which large‐scale variables restrict the potential for macroinvertebrate traits or taxa at smaller spatial scales. Catchment and reach variables were equally influential in defining assemblage attributes, whereas the reach scale was more influential in determining relative abundance and presence/absence.
Ultimately, comprehending the relative influence of catchment and reach scale properties in structuring stream biota will assist prioritising the scale at which to rehabilitate, manage and derive policies for stream ecosystem integrity.
Ecological strategies in the ancient asexual animal group Darwinulidae (Crustacea, Ostracoda)
Authors: Van Doninck Karine , Schön Isa , Maes Fre , De Bruyn Luc , Martens Koen 
Published: July 2003

Summary

We investigated the relationship between geographical distribution and ecological tolerance within the ancient asexual family Darwinulidae. Distribution maps were compiled based on data from the literature, the Non‐marine Ostracod Distribution in Europe database and personal collections. Ecological tolerance was assessed experimentally by exposing individual ostracods to a combination of eight different salinities (range from 0 to 30 g L−1) and three different temperatures (10, 20 and 30 °C).
The type species of the family, Darwinula stevensoni, is ubiquitous and cosmopolitan; the two species Penthesilenula brasiliensis and Microdarwinula zimmeri also have an intercontinental distribution. Two other darwinulid species tested here (Vestalenula molopoensis and P. aotearoa) are known only from their type localities. The latter is also true for most extant darwinulids.
Darwinula stevensoni and P. brasiliensis had a broad salinity tolerance, tolerating distilled water and also salinity up to 25–30 g L−1, whereas the maximum salinity tolerance of V. molopoensis was 12 g L−1 and of P. aotearoa, 20 g L−1.
The results indicate that both ecological specialists and generalists, as well as intermediate forms, exist in the Darwinulidae and that taxa with the broadest ecological tolerance also have the widest distribution.
Ecosystem CO2 exchange and plant biomass in the littoral zone of a boreal eutrophic lake
Authors: Larmola T. , Alm J. , Juutinen S. , Martikainen P. J. , Silvola J. 
Published: July 2003

Summary

In order to study the dynamics of primary production and decomposition in the lake littoral, an interface zone between the pelagial, the catchment and the atmosphere, we measured ecosystem/atmosphere carbon dioxide (CO2) exchange in the littoral zone of an eutrophic boreal lake in Finland during two open water periods (1998–1999). We reconstructed the seasonal net CO2 exchange and identified the key factors controlling CO2 dynamics. The seasonal net ecosystem exchange (NEE) was related to the amount of carbon accumulated in plant biomass.
In the continuously inundated zones, spatial and temporal variation in the density of aerial shoots controlled CO2 fluxes, but seasonal net exchange was in most cases close to zero. The lower flooded zone had a net CO2 uptake of 1.8–6.2 mol m−2 per open water period, but the upper flooded zone with the highest photosynthetic capacity and above‐ground plant biomass, had a net CO2 loss of 1.1–7.1 mol m−2 per open water period as a result of the high respiration rate. The excess of respiration can be explained by decomposition of organic matter produced on site in previous years or leached from the catchment.
Our results from the two study years suggest that changes in phenology and water level were the prime cause of the large interannual difference in NEE in the littoral zone. Thus, the littoral is a dynamic buffer and source for the load of allochthonous and autochthonous carbon to small lakes.
Distribution of benthic diatoms in U.S. rivers in relation to conductivity and ionic composition
Authors: Potapova Marina , Charles Donald F. 
Published: July 2003

Summary

We quantified the relationships between diatom relative abundance and water conductivity and ionic composition, using a dataset of 3239 benthic diatom samples collected from 1109 river sites throughout the U.S.A. [U.S. Geological Survey National Water‐Quality Assessment (NAWQA) Program dataset]. This dataset provided a unique opportunity to explore the autecology of freshwater diatoms over a broad range of environmental conditions.
Conductivity ranged from 10 to 14 500 μS cm−1, but most of the rivers had moderate conductivity (interquartile range 180–618 μS cm−1). Calcium and bicarbonate were the dominant ions. Ionic composition, however, varied greatly because of the influence of natural and anthropogenic factors.
Canonical correspondence analysis (CCA) and Monte Carlo permutation tests showed that conductivity and abundances of major ions (HCO + CO, Cl−, SO, Ca2+, Mg2+, Na+, K+) all explained a statistically significant amount of the variation in assemblage composition of benthic diatoms. Concentrations of HCO + CO and Ca2+ were the most significant sources of environmental variance.
The CCA showed that the gradient of ionic composition explaining most variation in diatom assemblage structure ranged from waters dominated by Ca2+ and HCO + CO to waters with higher proportions of Na+, K+, and Cl−. The CCA also revealed that the distributions of some diatoms correlated strongly with proportions of individual cations and anions, and with the ratio of monovalent to divalent cations.
We present species indicator values (optima) for conductivity, major ions and proportions of those ions. We also identify diatom taxa characteristic of specific major‐ion chemistries. These species optima may be useful in future interpretations of diatom ecology and as indicator values in water‐quality assessment.
Spatial and temporal distribution of fish and zooplankton in a shallow lake
Authors: Romare Pia , Berg Søren , Lauridsen Torben , Jeppesen Erik 
Published: July 2003

Summary 1. We performed both a large‐ and a small‐scale echo sounding study on the spatial and temporal distribution of fish (mainly roach, Rutilus rutilus and perch, Perca fluviatlis), as well as a small‐scale study of zooplankton distribution in the small, shallow and eutrophic Lake Hanebjerg in Denmark. In the small‐scale study, sampling was conducted in open water as well as in the edge zone immediately outside two different types of vegetation.2. Fish daytime abundances differed between the northern and the southern parts of the lake and, on a small scale, small fish aggregated in the edge zones during day, preferably outside dense emergent vegetation. Copepods avoided emergent vegetation, while cladocerans showed no habitat preference. Both small fish and cladoceran numbers were found to be higher during night than day.3. The relative abundance (number per sample) of cladocerans in the edge zone immediately outside vegetation was negatively correlated with the relative abundance of fish in that zone. There was no correlation between cladoceran and fish abundance in open water, or between the relative abundance of copepods and fish.4. The presence of pelagic piscivores in combination with avoidance behaviour of both fish and zooplankton is a likely explanation for the observed distribution of small fish and cladocerans in Lake Hanebjerg. Both small‐ and large‐scale distribution patterns may be dependent on the type and distribution of complex structure in the lake. Even in a small lake, large‐scale patterns may affect the interpretation of small‐scale data.
Structuring of the cyanobacterial community by pelagic fish in subtropical reservoirs: experimental evidence from Australia
Authors: Hunt Richard J. , Matveev Vlad , Jones Gary J. , Warburton Kevin 
Published: July 2003

Summary1. Subtropical reservoirs of Australia are commonly subject to summer blooms of cyanobacteria. The potential for food web manipulation to control cyanobacterial blooms was investigated in Lake Maroon, south east Queensland using enclosures in which the density of the Australian gudgeon Hypseleotris spp. was manipulated.2. Zooplankton biomass and community structure were strongly affected by fish density. A size dependent predation effect of Hypseleotris on zooplankton was observed at ambient fish densities, and the community shifted towards a dominance of copepod juveniles and nauplii. Substantial increases in the populations of Ceriodaphnia and calanoid copepods were observed at low fish densities and in the absence of fish.3. At ambient fish densities total phytoplankton and the proportion of cyanobacteria were maintained at levels similar to those prevailing at day 0. Total phytoplankton and the proportion of cyanobacteria decreased substantially at low fish densities and in the absence of fish. Chlorophytes became dominant in the ‘no fish’ treatment and the grazing‐resistant species Oocystis and Dictyosphaerium were significantly higher than at ambient fish densities.4. The experiment demonstrated a strong positive relationship between Hypseleotris density and cyanobacteria, and the results suggest that subtropical reservoirs may be suited to food web manipulation as a means of controlling summer cyanobacterial blooms.