bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trypanosoma cruzi infection in mice induces a polyisotypic hypergammaglobulinaemia and parasite‐specific response involving high lgG2a concentrations and highly avid lgG1 antibodies
Authors: BOUHDIDI AYACHI EL , TRUYENS CARINE , RIVERA MARIA‐TERESA , BAZIN HERVÉ , CARLIER1 YVES 
Published: September 2010

SUMMARY Trypanosoma cruzi infection in BALB/c mice induced a reversible polyisotypic hypergammaglobulinaemia, with particularly high levels of IgG2a, IgM and IgE. Hypergammaglobulinaemia started during the acute phase of infection and persisted during chronic disease until 11–13 weeks post‐infection (w.p.i.), when immunoglobulin levels, with the exception of IgE, returned near normal values. Parasite‐specific antibodies counted for 14 to 23% of gammaglobulinaemia, in acute and chronic infection respectively. The titres of IgM antibodies rose from two w.p.i. IgA, IgE and IgG subclass antibodies built up gradually over the time of parasite clearance (i.e., between three and six w.p.i.). All antibody isotypes, including IgM reached significant and stable titres throughout chronic infection. IgG2a, IgG1 and IgM antibodies had constantly higher titres than the other antibody isotypes. The dominance of IgG2a antibodies was due to their high plasma concentrations, around 70% of all antibodies available in the chronic infection. IgG1 had the highest functional avidity, whereas its concentration corresponded to only 10% of the whole antibody fraction. These results indicate that T. cruzi infection in mice induces a polyisotypic humoral immune response, dominated by some antibody isotypes, with major differences in concentrations and functional avidities. This could be of crucial importance in determining the outcome of infection.
Theileria annulata sporozoite surface antigen (SPAG‐1) contains neutralizing determinants in the C terminus
Authors: BOULTER NICKY , KNIGHT PAMELA A. , HUNT PHILIP D. , HENNESSEY EMMA S. , KATZER FRANK , TAIT ANDREW , WILLIAMSON SUSANNA , BROWN DUNCAN , BAYLIS HOWARD A. , HALL ROGER 
Published: September 2010

SUMMARYSPAG‐1 is a surface antigen on Theileria annulata sporozoites that is a candidate both for inclusion in a subunit vaccine and as a ligand for host cell recognition. We have pinpointed major neutralizing epitopes to the C terminus. To facilitate this we expressed SPAG‐1 as a series of defined fragments in the pGEX system. These constructs were validated by sequencing and by their spectrum of reactivity with monoclonal antibody (MoAb) BA4. This MoAb recognizes the elastin motif VGVAPG, that is predicted to occur three times in the N terminal half of SPAG‐1. The recombinant proteins were then tested by Western blotting with a neutralizing MoAb (1A7) and two neutralizing bovine sera (10T and 34A). The results demonstrate that 1A7 and the bovine sera react with determinants unique to the C terminus. We mapped the neutralizing determinant recognized by MoAb 1A7 to a 16 residue sequence (residues 807–822) using synthetic peptides. Interestingly the bovine sera do not recognize the 1A7 epitope. The potential role of the C terminus as a ligand for host cell recognition and the implications for sub‐unit vaccine production are discussed.
Lymphocyte proliferation and cytokine production in mice infected with different geographical isolates of Trichinella spiralis
Authors: GOYAL P. K. , HEŘMÁNEK J. , WAKELIN D. 
Published: September 2010

SUMMARYAntigen‐specific proliferative responses and cytokine production were measured in lymphocytes taken from inbred NIH mice infected with different isolates of Trichinella spiralis. Stimulation with muscle larval homogenate antigen produced high proliferative responses, cells responding more strongly to antigen from one isolate (London‐L) than to antigens of the other two isolates (Spanish‐S and Polish‐P). Antigen from the P‐isolate elicited relatively poor responses. There was considerable, although variable, cross reactivity between isolate antigens and this was reflected in proliferation to heterologous stimulation. When pulsed with the mitogen Concanavalin A (Con‐A) mesenteric lymph node cells (MLNC) produced IFN‐gamma on day four post infection but not on day eight. In contrast, production of IL‐4 and IL‐5 was greatest on day eight. Differences were seen in levels of cytokine production between cells taken from mice infected with different isolates. These data show a sequential activation of Th1 and Th2 cells during infection with T. spiralis isolates, and suggest that the level of activation of each Th subset is influenced by the antigenic characteristics of each isolate.
BCG–malaria co‐Infection has paradoxical effects on C57BL/6 and A/J mouse strains
Authors: LEISEWITZ A.L. , ROCKETT K. , KWIATKOWSKI D. 
Published: September 2010

SUMMARY Bacillus Calmette‐Guérin (BCG) infection of the spleen is a potent modifier of splenic function. Prior to malaria infection, we infected two mouse strains of differing susceptibility to Plasmodium chabaudi AS (C57BL/6 and A/J) with this mycobacterium. We then evaluated aspects of spleen cell composition, architecture and cytokine expression, and correlated these with the outcome. BCG preinfection resulted in protection of the A/J mice but paradoxically resulted in mortality of the C57BL/6 mice. The latter developed higher parasitaemias that peaked earlier than the A/J mice rendered resistant by BCG. BCG infection induced remarkable changes to splenic histology examined by H&E staining, but there were no consistent differences between mouse strains. C57BL/6 mice had higher absolute numbers of all immune cell phenotypes than did A/J mice, and higher macrophage and dendritic cell proportions. BCG‐induced resistance in A/J mice was associated with an increased CD4+ expression of IFN‐γ whilst induced death in C57BL/6 mice was associated with excessive IFN‐γ expression. A moderate TH1 response in the A/J model may have been responsible for the improved survival, and an excessive TH1 response in the C57BL/6 model may have contributed to their death.
Identification of a 55 kDa Haemonchus contortus excretory/secretory glycoprotein as a neutrophil inhibitory factor
Authors: ANBU K. A. , JOSHI P. 
Published: September 2010

SUMMARYHaemonchus contortus is an economically important gastric parasite infecting sheep and goats. The parasite survives the host immune attack by releasing protective molecules. In the present study, a 55 kDa secretory glycoprotein (gp55) was identified that inhibited host neutrophils as judged by reduced H2O2 production by these cells. The binding of gp55 to neutrophils was confirmed by flow cytometry. This binding was mediated by cellular CD11b/CD18 integrin. The glycoprotein gp55 also bound to goat monocytes and lymphocytes and inhibited monocyte function. Using light fluorescence microscopy, gp55 was localized at the surface of adult worms. The absence of gp55 in the infective L3 larvae and its expression in the blood‐feeding stage support a role for gp55 in the parasitic stage of the organism.
Regulation of toll‐like receptors in intestinal epithelial cells by stress and Toxoplasma gondii infection
Authors: GOPAL R. , BIRDSELL D. , MONROY F. P. 
Published: September 2010

SUMMARY Intestinal epithelial cells (IECs) form a barrier between invading microorganisms and the underlying host tissues. IECs express toll‐like receptors (TLRs) that recognize specific molecular signatures on microbes, which activate intracellular signalling pathways leading to production of proinflammatory cytokines and chemokines. Stress hormones play an important role in modulation of proinflammatory cytokines and down‐regulation of immune responses. Here we demonstrated that expression levels of TLR‐2, TLR‐4, TLR‐9 and TLR‐11 were significantly increased in mouse IECs following infection with Toxoplasma gondii on day 8 postinfection. In contrast, expression of TLRs was significantly decreased in infected mice subjected to cold water stress (CWS + INF). Expression of TLR‐9 and TLR‐11 in the mouse MODE‐K cell line was significantly increased after infection. Expression of TLR‐9 and TLR‐11 in cells exposed to norepinephrine (NE) and parasites was significantly decreased when compared to cells exposed to parasites only. A significant increase was observed in SIGIRR, a negative regulator of TLRs in the CWS + INF group when compared to the INF group. Stress components were able to decrease expression levels of TLRs in IECs, decrease parasite load, and increase expression of a negative regulator thereby ameliorating intestinal inflammatory responses commonly observed during per oral T. gondii infection in C57BL/6 mice.
Depletion of stromal Pi induces high ‘energy‐dependent’ antenna exciton quenching (qE) by decreasing proton conductivity at CFO‐CF1 ATP synthase
Authors: TAKIZAWA KENJI , KANAZAWA ATSUKO , KRAMER DAVID M. 
Published: September 2010

ABSTRACTThis work tests two models to account for the effects of depletion of stromal inorganic phosphate (Pi), which results in down‐regulation of light capture via the exciton quenching (qE) mechanism and has been proposed to act in feedback regulation of the light reactions. In both models, antenna down‐regulation is activated by acidification of the lumen, despite the fact that linear electron flow (LEF) (and associated proton flux) is decreased upon Pi depletion. In one model, an imbalance of ATP or NADPH activates cyclic electron transfer around photosystem I (CEF1), increasing proton influx to the lumen. In the second, the effective conductivity of the CFO‐CF1 ATP synthase to protons (gH+) is decreased, retarding proton efflux from the lumen. Sequestering of Pi by mannose infiltration increased sensitivities of qE and pmf to LEF. The effects were attributable to decreases in gH+, but not to CEF1 and were largely reversed by subsequent Pi feeding. Rapid recovery of gH+ in the dark suggested that dark‐labile metabolic pools are responsible for regulation of the ATP synthase. Overall, these results support models where accumulation of Benson–Calvin cycle intermediates or lowering of stromal Pi below its KMat the ATP synthase, retards proton efflux from the lumen, leading to build‐up of pmf and subsequent down‐regulation of photosynthetic light capture.
Regulation of isoprene emission in Populus trichocarpa leaves subjected to changing growth temperature
Authors: WIBERLEY AMY E. , DONOHUE AUTUMN R. , MEIER MARY E. , WESTPHAL MAIKEN M. , SHARKEY THOMAS D. 
Published: September 2010

ABSTRACTThe hydrocarbon isoprene is emitted in large quantities from numerous plant species, and has a substantial impact on atmospheric chemistry. Temperature affects isoprene emission at several levels: the temperature at which emission is measured, the temperature at which leaves develop, and the temperatures to which a mature leaf is exposed in the days prior to emission measurement. The molecular regulation of the response to the last of these factors was investigated in this study. When plants were grown at 20 °C and moved from 20 to 30 °C and back, or grown at 30 °C and moved from 30 to 20 °C and back, their isoprene emission peaked within 3 h of the move and stabilized over the following 3 d. Trees that developed at 20 °C and experienced 30 °C episodes had higher isoprene emission capacities than did leaves grown exclusively at 20 °C, even 2 weeks after the last 30 °C episode. The levels and extractable activities of isoprene synthase protein, which catalyses the synthesis of isoprene, and those of dimethylallyl diphosphate (DMADP), its substrate, alone could not explain observed variations in isoprene emission. Therefore, we conclude that control of isoprene emission in mature leaves is shared between isoprene synthase protein and DMADP supply.
Exploring genetic and expression differences between physiologically extreme ecotypes: comparative genomic hybridization and gene expression studies of Kas‐1 and Tsu‐1 accessions of Arabidopsis thaliana
Authors: JUENGER THOMAS E. , SEN SAUNAK , BRAY ELIZABETH , STAHL ELI , WAYNE TIERNEY , MCKAY JOHN , RICHARDS JAMES H. 
Published: September 2010

ABSTRACTRecent studies have documented remarkable genetic variation among Arabidopsis thaliana accessions collected from diverse habitats. Of particular interest are accessions with putatively locally adapted phenotypes – that is, accessions with attributes that are likely adaptive at their sites of origin. These genotypes may provide insight into the genetic basis of adaptive evolution as well as allow the discovery of genes of ecological importance. We studied the physiology, genome content and gene expression of two physiologically extreme accessions (Tsu‐1 from Tsushima, Japan and Kas‐1 from Kashmir, India). Our study was conducted under two levels of soil moisture and accompanied by physiological measurements to characterize early responses to soil drying. Genomic hybridizations identified 42 503 single feature polymorphisms (SFP) between accessions, providing an initial screen for genetic differences. Transcript profiling identified a large number (5996) of genes exhibiting constitutive differences in expression including genes involved in many biological pathways. Mild soil drying resulted in only subtle physiological responses but resulted in gene expression changes in hundreds of transcripts, including 352 genes exhibiting differential responses between accessions. Our results highlight the value of genomic studies of natural accessions as well as identify a number of candidate genes underlying physiological differences between Tsu‐1 and Kas‐1.
Modelling of cyclic tidal rhythmites (Carboniferous of Indiana and Kansas, Precambrian of Utah, USA) as a basis for reconstruction of intertidal positioning and palaeotidal regimes
Authors: ARCHER ALLEN W. , JOHNSON TROY W. 
Published: September 2010

ABSTRACTAnalyses are presented for a variety of ancient cyclic tidal rhythmites, which exhibit well developed neap‐spring tidal periods. Many such rhythmites were formed within the upper intertidal zone and exhibit truncated cycles that contain relatively few discrete lamina per neap‐spring cycle. In such cases it can be difficult to determine if the originated palaeotidal system was diurnal or semidiurnal.Based on sedimentological controls observed in modern analogues, the development of cyclic tidal rhythmites can be modelled by use of predicted tidal‐height information. The modelling used a 19‐year‐long series of tidal heights, which were subsequently used to approximate tidal velocities and rhythmite sedimentation. Modelling was based on a range of diurnal to semidiurnal regimes and comparisons were performed at a number of levels within the intertidal zone. This modelling produced a long series of simulated laminae‐thickness series which could be cross‐correlated with ancient laminae‐thickness series measured directly from ancient rhythmites.This approach involved 1.6 × 106 comparisons of each ancient rhythmite series to the series simulated from the predictive tidal‐height information. The high correlations derived for such comparisons indicate that reasonable approximations to the palaeotidal systems can be made. In some cases, it is possible to determine the diurnal or semidiurnal nature of the originating palaeotidal system.
Bed thickness characteristics of inner‐shelf storm deposits associated with a transgressive to regressive Holocene wave‐dominated shelf, Sendai coastal plain, Japan
Authors: TAMURA TORU , MASUDA FUJIO 
Published: September 2010

AbstractHolocene inner‐shelf storm deposits preserved beneath the Sendai coastal plain facing the Pacific coast of north‐eastern Japan were formed during a transgressive–regressive cycle. The evolution of the Holocene wave‐dominated depositional system along the Sendai coast is reconstructed using 76 AMS (accelerator mass spectrometers) 14C ages and the origin of bed thickness variations in the inner‐shelf storm deposits is explored. The Holocene succession is <30 m thick and overlies latest Pleistocene to early Holocene non‐marine deposits above a transgressive ravinement surface. It comprises transgressive ravinement and inner‐shelf deposits, and regressive inner shelf, shoreface, and coastal plain deposits. The inner‐shelf deposits comprise alternating sand and mud layers interpreted as stacked storm beds. The average preservation interval of a single storm bed is shortest during the transgression (5·7–20·6 years), and then increases to a maximum during the early regression (83·3–250·0 years), decreasing to 7·7–31·3 years with shoreline progradation. Average accumulation rates decreased during the transgression and then increased during the regression, but the sand/mud ratio varies little, reflecting inefficient sediment segregation downdip on the inner shelf. The vertical pattern of sand‐layer thicknesses also shows no relationship to position within the cycle, although small‐scale intervals of upward thickening and thinning probably relate to lateral switching of river mouths and/or random storm processes. The average thickness of storm beds is the highest in the interval deposited during the period from maximum flooding to early regression. This is probably because of the low preservation potential of thin beds associated with frequent, low‐magnitude storms during this period of low accumulation rates and extensive reworking. This preservation bias and the nature of the Sendai inner shelf resulted in an absence of characteristic bed thickness trends in the preserved storm deposits.
Molar tooth structures of the Neoarchean Monteville Formation, Transvaal Supergroup, South Africa. II: A wave‐induced fluid flow model
Authors: BISHOP JAMES W. , SUMNER DAWN Y. , HUERTA NICOLAS J. 
Published: September 2010

AbstractSedimentological, morphological, and geochemical characteristics of molar tooth (MT) structures in the ca 2·6 Ga Monteville Formation suggest a new fluid flow model for MT formation: (i) intercalated shales and carbonate sands were deposited near to above storm wave base; (ii) sediments cracked, forming an interconnected network of MT cracks that were also open to pores in sand lenses; (iii) storm waves pumped sea water into open MT crack networks, causing rapid microcrystalline carbonate nucleation, Ostwald ripening of nuclei, and growth of granular carbonate cores; some of these cores were transported by water flowing through the cracks; (iv) unfilled MT cracks collapsed, and filled MT ribbons deformed plastically as host sediments compacted and dewatered; (v) carbonate cores were overgrown by polygonal rims; and (vi) MT structures deformed brittlely with additional compaction and produced pebbly lags if reworked. MT cracks may have formed by multiple mechanisms; however, expansion of gas from organic decay and sediment heaving due to wave loading best explain MT crack morphology and are most consistent with the fluid flow model for MT CaCO3 presented here.
In vitroandin vivoevaluation of a potentiated miconazole aural solution in chronicMalasseziaotitis externa in dogs
Authors: Hensel Patrick , Austel Michaela , Wooley Richard E. , Keys Deborah , Ritchie Branson W. 
Published: September 2010

AbstractThis study assessed thein vitroandin vivoactivity of an ear solution containing a third‐generation chelating agent (Tricide®) as an antimicrobial potentiator for miconazole in chronicMalasseziaotitis. Thirty‐one ears from 20 dogs were enrolled in the study. Fungal culture, minimum inhibitory concentration (MIC), and minimum fungicidal concentration (MFC) testing of miconazole with and without Tricide®were performed on all ears. In a randomized, controlled, and blinded treatment trial the ears were treated either with 0.9% saline solution containing 0.01% miconazole, 0.03% dexamethasone and 540 μg/mL Tricide®or the same solution without Tricide®. Cytologic and auroscopic examinations were conducted on day 0, 14 and 28 and evaluated for number of yeast organisms, degree of erythema, hyperplasia and amount of discharge. Thein vitrodata was compared with Wilcoxon signed‐rank test. The cytologic and auroscopic scores were compared between the visits and treatment groups at day 0, 14 and 28 using a Wilcoxon–Mann–Whitney test and repeated measures analysis. MIC and MFC were significantly (P < 0.0001) reduced when miconazole was combined with the chelating agent versus miconazole alone. The cytologic scores were significantly lower on days 14 (P = 0.0156) and 28 (P = 0.0280) for the group treated with Tricide®. The auroscopic scores decreased significantly by the end of the trial compared to day 0, but the difference between the two groups was not significant. This study suggests that Tricide®enhancesin vitroactivity andin vivoefficacy againstMalasseziasp. in dogs with yeast otitis.
Monoterpene emissions from ornamental trees in urban areas: a case study of Barcelona, Spain
Authors: Noe S. M. , Peñuelas J. , Niinemets Ü. 
Published: September 2010

AbstractResearch on biogenic volatile organic compound (BVOC) emissions has mainly focused on native species in natural ecosystems. However, much of the ozone and aerosol formation occurs in city atmospheres due to BVOC emissions by local urban vegetation. Plant composition of urban habitats is often dominated by non‐native ornamental plant species, for which only limited data on BVOC emissions are available. To gain insight into the influence of ornamental vegetation on the urban atmospheric reactivity in Barcelona, Spain, we studied volatile isoprenoid emissions in 11 widespread ornamental tree species (three conifers and nine angiosperms). We found significant monoterpene emissions in all studied species, with normalized emission potentials (T = 30 °C, photosynthetic photon flux density (PPFD) = 1000 μmol·m−2·s−1) ranging between 0.2 to 110 μg·g−1 (dry weight) h−1. Depending on species, the emissions were dominated by α‐ and β‐pinene, myrcene, α‐ and β‐phellandrene, carene, limonene and eucalyptol. These data demonstrate that ornamental plants may significantly contribute to the BVOC load in urban atmospheres and also underscore the importance of broadleaf angiosperms as significant monoterpene emitters.
Changes in Whistle Structure of Two Dolphin Species During Interspecific Associations
Authors: May‐Collado Laura J. 
Published: September 2010

AbstractDolphin communicative signals show great plasticity. Dolphins modify signal structure to cope with their environment, in response to stress, and in some species to mimic group members. Hence, whistle structure variations may offer insights to interspecific associations among dolphin species, which although temporal and opportunistic are common. In this study, I test the hypothesis that interspecific interactions influence dolphin whistle structure, particularly during social events. The study took place in the Southern Caribbean coast of Costa Rica, where interspecific associations of the distantly related Guyana and Bottlenose dolphins occur on daily basis. The results indicate that interspecific groups emit whistles that show intermediate whistle structure compared to whistles emitted in intraspecific groups. This pattern is seen during social interactions between species, but not when interspecific groups are traveling. Social events in interspecific groups were of antagonistic nature, where Bottlenose dolphins isolated and harassed one or two Guyana dolphins. Contour data suggest that the most vocal species during these encounters was the Guyana dolphin. Therefore, the observed modifications in whistles structure likely reflect a stress response by the Guyana dolphins. Another alternative explanation includes signal convergence between interacting species. However, to understand the nature of these potential modifications, future studies should combine acoustic tags and directional recording systems to follow the vocalizing animals. Despite the shortcomings of this study, it provides some of the first insights into dolphin interspecific communication, providing evidence of overall signal change during interspecific interactions.