bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ontogeny of Complement Regulatory Proteins – Concentrations of Factor H, Factor I, C4b‐Binding Protein, Properdin and Vitronectin in Healthy Children of Different Ages and in Adults
Authors: De Paula P. F. , Barbosa J. E. , Junior P. R. , Ferriani V. P. L. , Latorre M. R. D. O. , Nudelman V. , Isaac L. 
Published: November 2003

AbstractPrevious studies of human in vivo complement protein levels have only compared data for neonates with that from adult sera. Here, we establish the normal concentration ranges of the following complement regulatory proteins in healthy Brazilian children of different age groups (neonates: 1 month−1 year, 1–6 years and 6–13 years) and in adults: factor H (fH), factor I (fI), C4b‐binding protein (C4 BP), properdin and vitronectin. We found that the concentrations of fH, fI, properdin and vitronectin in neonates are significantly lower than in adults. Remarkably, the concentration of C4 BP is below the method resolution (<50 µg/ml) in 76% of the sera from neonates, while adults presented 199–532 µg/ml of C4 BP in their sera. The concentration of properdin in the sera from neonates and up to 1‐year‐old children was less than that observed in older children. Adults presented vitronectin levels significantly higher than all the other age groups in the study. No significant sex differences in the concentrations of all the studied regulatory proteins were detected. This study reveals the ontogeny of complement system in greater detail than previously available and may point to the reasons why neonates have higher susceptibility to develop life‐threatening pyogenic infections. These reference values will be of use in clinical and laboratory investigations of disorders associated with low levels of these regulatory proteins.
Nitric Oxide Produced by Murine Dendritic Cells is Cytotoxic for Intracellular Salmonella enterica sv. Typhimurium
Authors: Eriksson S. , Chambers B. J. , Rhen M. 
Published: November 2003

AbstractThe pathogenicity of Salmonella enterica serovar Typhimurium has traditionally been correlated with its ability to survive and grow in macrophages. Macrophage‐derived production of nitric oxide (NO) has been implicated as a major innate defence, restricting bacterial proliferation both in macrophage cultures and in mice. In the present study, we show that the ability of primary murine dendritic cells (DCs) to ingest Salmonella is low, but greatly enhanced by serum complement. Ingestion of bacteria was followed by the expression of inducible nitric oxide synthase (iNOS), as well as by NO production. iNOS mRNA was detected as early as 6 h post infection and production of NO 12 h post infection, rising further at 16 h post infection. Inhibition of the iNOS activity with the inhibitor N‐monomethyl‐l‐arginine or using DCs from iNOS–/– mice resulted in increased intracellular bacterial yields. To further define the potential defensive role of DC‐derived NO, the actual intracellular replication rate of S. Typhimurium in DCs was measured. DC‐derived NO was shown to exert a bactericidal effect, whereas the effect of NO in macrophage‐like J774‐A.1 cells was found to be bacteriostatic. These results identified an important role for NO in restricting S. Typhimurium survival in DCs, indicating that DCs may actively participate in the innate defence against intracellular pathogens.
A Protocol for Generation of Clinical Grade mRNA‐Transfected Monocyte‐Derived Dendritic Cells for Cancer Vaccines
Authors: Mu L. J. , Gaudernack G. , Sæbøe‐Larssen S. , Hammerstad H. , Tierens A. , Kvalheim G. 
Published: November 2003

AbstractWith the aim of producing large quantities of mRNA‐transfected monocyte‐derived dendritic cells (DCs) to be used as cancer vaccines, a new clinical grade procedure has been developed. Peripheral blood mononuclear cells (PBMCs) obtained by leukapheresis were enriched for monocytes by immunomagnetic depletion of CD19+ B cells and CD2+ T cells employing the ISOLEX 300i device. After 5 days of culture of enriched monocytes in gas permeable Teflon bags, using serum‐free medium supplemented with granulocyte/macrophage‐colony stimulating factor and interleukin‐4 (IL‐4), immature DCs were generated. Following transfection with mRNA from three human prostate cancer cell lines (DU145, LNCaP and PC‐3), employing a newly developed square wave electroporation procedure, the immature DCs were immediately transferred to Teflon bags and matured for 48 h, using serum‐free medium supplemented with IL‐1α, IL‐6, tumour necrosis factor‐α and PGE2. The electroporation procedure efficiently transferred mRNA into the DCs with minor effect on the viability of the cells. The generated matured transfected DCs show high expression of the antigens CD83, CD80, CD86 and human leucocyte antigen‐DR. Freezing and thawing of the transfected matured DCs had minor effect on cell viability and the phenotype. From 4 × 109 PBMCs, about 1 × 108 transfected matured DCs are produced. The thawed transfected DCs were able to elicit primary T‐cell responses in vitro against antigens encoded by the prostate cancer mRNA as shown by enzyme‐linked immunospot assay using mock‐transfected DCs as control. Based on these results, clinical trials in cancer patients have been initiated.
B‐Cell Epitopes in the Immunodominant p34 Antigen ofMycobacterium aviumssp.paratuberculosisRecognized by Antibodies from Infected Cattle
Authors: Ostrowski M. , Mundo S. L. , Harris N. B. , Barletta R. G. , Lopez O. J. 
Published: November 2003

AbstractMycobacterium aviumssp.paratuberculosis(M. paratuberculosis) causes Johne's disease, a chronic and fatal enteritis in ruminants. In the last stage of the disease, antibody titres rise and levels of interferon‐γ decrease, suggesting that the host–immune response is switching from a T helper 1 (Th1) to a Th2 profile. In infected cattle, the membrane protein p34 elicits the predominant humoral response againstM. paratuberculosis. To map the B‐cell epitopes of this antigen, affinity‐purified bovine antibodies against the carboxy‐terminal region of p34 were used to screen a 12‐mer phage display library. Several phage clones carrying peptides resembling fragments of p34 were affinity selected. Based on the predicted amino acid sequence, peptides were chemically synthesized, which demonstrated reactivity with serum from naturally infected and p34‐vaccinated cattle. Immunization of mice with these peptides elicited an anti‐p34 antibody response. Two B‐cell epitopes were identified and characterized. Based on the reactivity and the type of immune response elicited, epitope A was determined to be conformational, whereas epitope B was demonstrated to be sequential. Both epitopes were shown to be present in p34 proteins fromM. aviumssp.aviumorM. paratuberculosisbut absent fromM. intracellulare, the other member of theM. aviumcomplex. Furthermore, both epitopes were mapped to regions of p34 that display high variability when compared to homologous proteins from other mycobacterial species of public and animal health importance. We hypothesize that these variable regions of p34 may play a role in the immunobiology ofM. paratuberculosisinfections.
Long‐Term Evaluation of a Rat Model of Chronic Cholangitis Resembling Human Primary Sclerosing Cholangitis
Authors: Goetz M. , Lehr H. A. , Neurath M. F. , Galle P. R. , Orth T. 
Published: November 2003

AbstractPrimary sclerosing cholangitis (PSC) is a chronic cholestatic disorder with a presumed autoimmune aetiopathogenesis. We have recently described a novel organ‐specific rat model of fibrosing cholangitis induced by intrabiliary administration of the hapten‐reagent 2,4,6‐trinitrobenzenesulfonic acid (TNBS) with similarities to human PSC. In the present report, we have evaluated the long‐term outcome of TNBS‐induced cholangitis in this model. Mild stenosis of the common bile duct of female Lewis rats (n = 18) was achieved by subtotal ligation and cholangitis induced by TNBS injection (50 mg/kg) into the dilated bile duct after a second laparotomy. After 8 and 12 months, we found no evidence of cholangitis in serum chemistry or histology or retrograde cholangiography of TNBS‐treated rats. Antineutrophil cytoplasmic antibodies were positive in 75% of animals but were not predictive of liver damage. Tumour necrosis factor‐α levels were not elevated in serum or in mononuclear spleen cell supernatants. Our findings suggest that a single initial insult is not sufficient to trigger chronic progressive inflammation. Rather, perpetuation of inflammation probably requires additional stimuli.
Adjuvant Activity of Free Bordetella Pertussis Filamentous Haemagglutinin Delivered by Mucosal Routes
Authors: Poulain‐Godefroy O. , Menozzi F. D. , Alonso S. , Vendeville C. , Capron A. , Locht C. , Riveau G. 
Published: November 2003

AbstractThe development of safe and potent mucosal adjuvants remains a major objective in vaccinology. The potential usefulness of filamentous haemagglutinin (FHA) of Bordetella pertussis as an adjuvant was assessed in a mouse model. The glutathione‐S‐transferase of Schistosoma mansoni (Sm28GST) was used for intranasal administration, while the gut‐resistant keyhole limpet haemocyanin (KLH) was administrated by the oral route. For both antigens, coadministration with FHA increased antigen‐specific immunoglobulin titres. This adjuvant effect did not require chemical cross‐linking or direct interaction between FHA and the antigen tested. FHA also behaved as an adjuvant by the subcutaneous route, indicating that its adjuvanticity is not restricted to binding to mucosal surfaces. The FHA‐induced adjuvanticity was also observed in mice with high anti‐FHA antibody titres as a result of antipertussis vaccination, indicating that pre‐existing anti‐FHA antibodies do not impair FHA adjuvanticity. No mRNA coding for proinflammatory cytokines was induced in the lungs after intranasal FHA administration. However, an increase in the levels of mRNAs coding for B7‐1, transforming growth factor (TGF)‐β and major histocompatibility complex (MHC)‐II was detected in the lungs after FHA administration. Although the molecular mechanisms of the FHA‐induced adjuvanticity remain to be elucidated, the data presented here indicate that this adhesin, already assessed for human use as a pertussis vaccine constituent, represents a promising adjuvant to improve the humoral immune response when given by mucosal routes.
Long‐Term Proliferation and Survival of In Vitro‐Activated T Cells is Dependent on Interleukin‐2 Receptor Signalling but not on the High‐Affinity IL‐2R
Authors: Hedfors I. A. , Brinchmann J. E. 
Published: November 2003

AbstractOptimization of T‐cell‐activation protocols is an important prerequisite for the use of populations of activated, polyclonal T cells for immunotherapeutic purposes. This study compares two activation protocols. Following initial CD3/CD28 activation, naïve and memory subsets of CD8+ and CD4+ T cells were either repeatedly stimulated or maintained in medium containing interleukin‐2 (IL‐2). Initially, activation‐induced cell death (AICD) was observed in all subsets. After 2–3 days, death in the cultures maintained in IL‐2 only dropped dramatically, while live cells increased logarithmically. Despite intense proliferation, these cells lost the expression of CD25, the α chain of the IL‐2 receptor and CD71, the transferrin receptor. Functional blocking of CD25 caused minimal changes in proliferation and survival of these cells as long as IL‐2 was present in the medium. Blocking of CD25 in combination with the removal of IL‐2 caused rapid death of these cells. Restimulation every 3–4 days led to persistently high levels of AICD and lower live cell counts. Live cells maintained the expression of activation markers and a blastoid phenotype. Initial CD3/CD28 followed by maintenance in IL‐2 for 2–3 weeks seems to be the best in vitro T‐cell‐activation strategy. Signalling through the IL‐2 receptor is vital for these cells, despite their downregulation of CD25.
Biochemical Changes Contributing to Functional Quiescence in Lacrimal Gland Acinar Cells after Chronic Ex Vivo Exposure to a Muscarinic Agonist
Authors: Qian L. , Wang Y. , Xie J. , Rose C. M. , Yang T. , Nakamura T. , Sandberg M. , Zeng H. , Schechter J. E. , Chow R. H. , Hamm‐Alvarez S. F. , Mircheff A. K. 
Published: November 2003

AbstractProfound secretory dysfunction can be associated with relatively modest lymphocytic infiltration of the lacrimal and salivary glands of Sjögren's syndrome (SjS) patients. SjS patients' sera contain autoantibodies to M3 muscarinic acetylcholine receptors (MAChR) that have variously been reported to have agonistic and antagonistic effects. We sought to identify consequences of chronic agonist stimulation by maintaining acinar cells from rabbit lacrimal glands for 20 h in the presence or absence of 10 µm carbachol (CCh). Exposure to CCh diminished the cells' ability to elevate cytosolic Ca2+ and secrete β‐hexosaminidase in response to acute stimulation with 100 µm CCh, but it enhanced their secretory responses to phenylephrine and ionomycin. Secretory vesicles appeared normal by electron microscopy, but confocal fluorescence microscopy revealed depletion of the secretory vesicle membrane marker, rab3D, and decreased ability to recruit secretory transport vesicles in response to acute 100 µm CCh. Additionally, the apical cortical actin cytoskeleton was disrupted and diminished compared to the basal–lateral cortical network. Subcellular fractionation analyses revealed that total membrane phase protein content was increased. The contents of β‐hexosaminidase and MAChR relative to total protein were not significantly altered, and MAChR abundance in the plasma membrane fraction was increased as the result of redistribution from endomembrane pools. However, relative cellular contents of the heterotrimeric guanosine triphosphate (GTP)‐binding proteins, Gq and G11, were decreased. Additional biochemical changes included decreased contents of 47 kDa Gs and Gi3, protein kinase Cα and rab3D and polymeric immunoglobulin (Ig) receptors; internalization of Na,K‐ATPase from the plasma membranes to endomembrane compartments and decreased content of β‐hexosaminidase in the lysosomes. The observations demonstrate that chronic exposure to a MAChR agonist induces refractoriness to optimal stimulation, without causing receptor downregulation, by downregulating postreceptor‐signalling mediators and effectors. The cells' secretory mechanisms for IgA and electrolytes also appear to be impaired, as does their ability to properly sort proteins to the lysosomes.
Turbidite and contourite sediment waves in the northern Rockall Trough, North Atlantic Ocean
Authors: HOWE JOHN A. 
Published: November 2003

ABSTRACTTwo sediment wave fields have been identified in the northern Rockall Trough; one from the north‐eastern part of the trough, developed on the flank of an elongate sediment drift, and the other at the distal edge of the Barra Fan. Wavelengths in both areas vary from 1 to 2 km and wave heights from 5 to 20 m. The seismic character of both the wave fields is similar with a lower package of well‐layered, medium‐ to high‐intensity reflectors migrating upslope, overlain by a dominantly acoustically transparent unit containing irregular, semicontinuous reflectors. Eight cores have been recovered from the two wave fields, seven from the crest‐trough areas of the distal Barra Fan wave field, and a single core from the crest of the sediment‐drift waves. Lithologically, the cores show that different processes have been active across the two wave fields. Cores from the Barra Fan field contain thin turbidites with thicker, draped hemipelagites and hemiturbidites, corresponding to the well‐layered, reflective seismic units and transparent seismic unit, respectively. These waves have been maintained by turbidity currents, perhaps over older, originally bottom‐current‐formed waves. The single core from the small sediment‐drift wave field recovered hemipelagites and glaciomarine sediments grading upwards into muddy‐silty contourite deposits, topped by a sandy contourite. These waves were constructed by contour currents. Dating of cores from these two small wave fields revealed that the sequences of thin turbidite and hemipelagite sediments from the Barra Fan correspond to the Late Glacial‐Allerød/Bölling Interstadial with the overlying hemipelagite of Younger Dryas‐Holocene age. The contourite deposits from the north‐east Rockall Trough wave field have been dated as early Holocene, reflecting increasing bottom‐current activity at the changeover from a glacial to an interglacial regime.
Carbonate petrography as an indicator of climate and sea‐level changes: new data from Bahamian Quaternary units
Authors: KINDLER PASCAL , HEARTY PAUL J. 
Published: November 2003

ABSTRACTCoeval stratigraphic units of similar petrology occur throughout the northern Bahamas islands. The petrographic composition of these limestones provides clues about regional sea level and climate changes during the late Quaternary. At least eight fossil shoreline units, which are linked to transgressive episodes between the middle Pleistocene and the late Holocene, are recognized in the Bahamas. The petrographic composition of these units is either dominated by ooids and peloids or by bioclasts. Sedimentological observations demonstrate that oolitic‐peloidal units were formed when sea level was higher than today, whereas skeletal units were deposited at or below modern ordnance datum. Skeletal units may reflect times of partial, or modest platform flooding, when the bulk of sediments brought to islands originates from bank‐margin reefs. In contrast, oolitic‐peloidal units correspond to major flooding events and active water circulation on the bank top. Cement fabrics further show that the early diagenesis of oolitic units took place during warm and humid climatic conditions, whereas skeletal rock bodies underwent subaerial diagenesis during drier climatic conditions characterized by marked seasonal changes. This example from the Bahamas suggests that compositional analysis of limestone from fossil carbonate platforms could be used for resolving ancient climate and sea‐level changes.
Cross‐platform architecture of a sequence boundary in mixed siliciclastic‐carbonate lithofacies, Middle Cambrian, southern Great Basin, USA
Authors: OSLEGER DAVID A. , MONTAÑEZ ISABEL P. 
Published: November 2003

ABSTRACTStratigraphic analysis of mixed siliciclastic‐carbonate lithofacies within the Middle Cambrian Bonanza King Formation of the southern Great Basin reveals three distinct facies associations that record a range of depositional environments from semi‐arid tidal flats to deeper subtidal, restricted lagoons. Stratigraphic trends, cross‐platform facies variations and correlation of individual surfaces across 250 km of the study area suggest that these mixed lithofacies were deposited in three temporally distinct phases. (1) Extensive progradation of mixed peritidal environments culminated in a prolonged episode of subaerial exposure marked by an areally extensive intraclast breccia (0·5–1·2 m thick) that we interpret to be a major Type 1 sequence‐bounding disconformity. (2) Abrupt flooding of the exposed platform resulted in the deposition of mixed deeper subtidal lithofacies, including a condensed interval of fissile, fossiliferous shale. (3) Progressive shallowing and aggradational accumulation was accompanied by a decrease in siliciclastics and a shift to pure carbonate deposition. Deep‐water siliciclastics and megabreccias record deposition along the base‐of‐slope off the Middle Cambrian shelf‐edge, and are interpreted to represent lowstand deposits emplaced during the prolonged episode of subaerial exposure of the shallow shelf.The presence of fine siliciclastics in both peritidal facies and sharply overlying deeper subtidal facies of the study interval within the Bonanza King suggests a variable, but relatively continuous, influx of terrigenous material throughout an extended period of accommodation change, apparently asynchronous with respect to the predictive model of reciprocal sedimentation. We suggest that the primary siliciclastic source changed with relative sea‐level position. During lowered sea level, aeolian processes acting upon the unvegetated Cambrian craton transported fine siliciclastics onto peritidal and shallow‐subtidal environments. During higher sea level, coastal siliciclastic reservoirs supplied sediment that was transported for long distances by geostrophic currents flowing along the submerged platform.As opposed to many Cambro‐Ordovician grand cycles that are commonly interpreted to consist of a transgressive shaly half‐cycle grading upward into a regressive carbonate half‐cycle, the sequence boundary within this Middle Cambrian succession occurs within siliciclastic‐rich, mixed lithofacies rather than in adjoining purer carbonates, implying that some ‘grand cycles’ should not be considered synonymous with ‘sequences’. Interbasinal correlations of the Type 1 sequence boundary within the mixed unit are speculative, primarily because of the inherent imprecision of available trilobite biostratigraphy. However, there is evidence that an extended episode of subaerial exposure may have been continent‐wide during the Ehmaniella trilobite biochron.
Origin and significance of mud‐filled incised valleys (Upper Cretaceous) in southern Alberta, Canada
Authors: EBERTH DAVID A. 
Published: November 2003

ABSTRACTSeven mud‐filled incised valleys (MFIVs) in the paralic facies of the Dinosaur Park and Horseshoe Canyon formations (Upper Cretaceous) of southern Alberta were studied to better understand their morphology, geometry and depositional histories in an estuarine context. Two preservational geometries occur: simple, U‐shaped forms; and internally complex forms. Both types of MFIV record deposition in the central zone of low energy (turbidity) in an estuarine setting.Simple, U‐shaped MFIVs have sharp basal erosional surfaces and consist of mudstone‐dominated heterolithic fills of channel‐wide, concave‐up laminae. Associated fossil assemblages are marine to brackish. Each simple MFIV records a cut‐and‐fill history associated with a cycle of relative sea‐level drop and rise. Low‐energy depositional settings, loss of channel form during infilling, and associated shoreface deposits, as well as the absence of clear tidal indicators suggest a coastal plain estuarine setting, along a wave‐dominated, barred coastline.Complex MFIVs are rarer, and consist of imbricated, wedge‐shaped sets of inclined‐to‐horizontal heterolithic strata. Tidal deposits and/or nonmarine‐to‐marine macrofossils occur locally. Complex MFIVs were infilled in meandering reaches of the central zone of low energy in tide‐dominated estuaries. Their rarity compared to simple MFIVs and their freshwater palaeontological content suggest that they were contiguous landward with extensive fluvial channels. A complex MFIV near Onefour comprises three in‐channel depositional cycles. Each cycle consists of an erosional surface overlain by lateral accretion bedding and a conformable transition to vertically aggraded strata. Each cycle reflects a cut‐and‐fill event under the control of changes in relative sea‐level that culminated in overbank flooding.All MFIVs formed in low‐gradient settings (≤0.03%) where estuarine zones were stretched out over many tens of kilometres. Tide‐dominated estuaries apparently exhibited simple, straight‐to‐meandering upstream transitions and extensive landward penetration (≥200 km) of tidal backwater effects. Few modern estuaries serve as adequate modern analogues to these ancient, tide‐dominated estuaries.Radiometric data indicate that MFIV cut‐and‐fill cycles were 100 000‐400 000 years in maximum duration and thus, equivalent to 4th order sea‐level cycles. However, negative evidence tentatively suggests that these cycles took place over time intervals 1‐2 orders of magnitude smaller (5th order or higher sea‐level cycles).