bluuebunny/crossref_metadata_2025_split huggingface dataset:
E prostanoid 2 (EP2)/EP4‐mediated suppression of antigen‐specific human T‐cell responses by prostaglandin E2
Authors: Okano Mitsuhiro , Sugata Yuji , Fujiwara Tazuko , Matsumoto Rie , Nishibori Masahiro , Shimizu Kenji , Maeda Megumi , Kimura Yoshinobu , Kariya Shin , Hattori Hisashi , Yokoyama Minehiko , Kino Kosuke , Nishizaki Kazunori 
Published: May 2006

SummaryProstaglandin E2 (PGE2) is a lipid mediator that displays important immunomodulatory properties, such as polarization of cytokine production by T cells. Recent investigations have revealed that the effect of PGE2 on cytokine production is greatly influenced by external stimuli; however, it is unclear whether PGE2 plays a significant role in major histocompatibility complex‐mediated antigen‐specific T‐cell responses via binding to one of four subtypes of E prostanoid (EP) receptor alone or in combination. In the present study, we sought to determine the effect of PGE2 on antigen‐specific CD4+ T‐cell responses in humans, especially in terms of receptor specificity. We used purified protein derivative (PPD) and Cry j 1 as T helper type 1 (Th1) and Th2‐inducing antigens, respectively. We generated several different Cry j 1‐ and PPD‐specific T‐cell lines (TCLs). PGE2 significantly and dose‐dependently inhibited the proliferation and subsequent production of interleukin‐4 by Cry j 1‐specific TCLs and of interferon‐γ by PPD‐specific TCLs upon antigen stimulation. Administration of EP2 receptor agonist and EP4 receptor agonist suppressed these responses in an adenylate cyclase‐dependent manner, while EP1 and EP3 receptor agonists did not. Messenger RNA for EP2, EP3 and EP4, but not EP1, receptors were detected in Cry j 1‐ and PPD‐specific TCLs, and no differences in EP receptor expression were observed between them. Furthermore, PGE2 and EP2 receptor agonist significantly inhibited interleukin‐5 and interferon‐γ production by peripheral blood mononuclear cells in response to Cry j 1 and PPD stimulation, respectively. These results suggest that PGE2 suppresses both Th1‐ and Th2‐polarized antigen‐specific human T‐cell responses via a cAMP‐dependent EP2/EP4‐mediated pathway.
Mannan derivatives induce phenotypic and functional maturation of mouse dendritic cells
Authors: Sheng Kuo‐Ching , Pouniotis Dodie S. , Wright Mark D. , Tang Choon Kit , Lazoura Eliada , Pietersz Geoffrey A. , Apostolopoulos Vasso 
Published: May 2006

SummaryMannan, a polysaccharide isolated from yeast binds to C‐type lectins of the mannose receptor family, expressed by antigen‐presenting cells (APCs) including dendritic cells (DCs) and macrophages. As these receptors mediate endocytosis, they have been targeted with ligands to deliver antigens into APCs to initiate immune responses. Immunization with tumour antigen MUC1 conjugated to oxidized mannan (OM) or reduced mannan (RM) induced differential immune responses in mice, and only mice immunized with OM‐MUC1 elicited strong MUC1‐specific cytotoxic T lymphocyte responses and protected mice from a MUC1 tumour challenge. In this study, the adjuvant effect of mannan and its derivatives including OM and RM, in comparison to lipopolysaccharide, on DCs were investigated. Mannan, OM and RM were capable of stimulating mouse bone marrow‐derived DC in vitro, eliciting enhanced allogeneic T‐cell proliferation and enhancing OTI/OTII peptide‐specific T‐cell responses. Injection of mice with mannan, OM and RM induced a mature phenotype of lymph node and splenic DCs. Analysis by reverse transcription–polymerase chain reaction indicated that Manna, OM and RM also stimulated up‐regulation of inflammatory cytokines including interleukin‐1β and tumour necrosis factor‐α, and differential T helper 1 (Th1)/Th2 cytokines. Subsequent experiments demonstrated that activation of DCs was Toll‐like receptor‐4‐dependent. The data presented here, together with evidence reported previously on OM and RM in induction of immune responses in vivo, suggest that OM and RM exert a dual capacity to target antigen to APCs as well as mature DCs.
TAP1–/– mice present oligoclonal BV‐BJ expansions following the rejection of grafts bearing self antigens
Authors: Marrero Idania , Huffman Donald , Kalil Jorge , Sercarz Eli E. , Coelho Verônica 
Published: May 2006

SummaryOur previous work showed that transporter associated with antigen processing 1 (TAP1)–/– (H‐2b) mice rejected grafts from H‐2b mice which display a normal density of class I major histocompatibility complex (MHC) molecules at the cell surface. Our results indicated that H‐2b molecules themselves may be a target in this kind of rejection and that CD4+ T cells play a major role in this autoreactive process. Our data also suggested that TAP1–/– mice, in addition to the well‐recognized phenotype of class I and CD8+ T‐cell deficiency, present a functional alteration in their autoreactive CD4+ T‐cell repertoires. In this model of inflammatory autoreactivity to modified self, we have analysed T‐cell receptor (TCR) V‐beta–J‐beta (BV‐BJ) usage by complementarity determining region 3 (CDR3) length spectratyping in splenocytes from naïve TAP1–/– mice and transplanted TAP1–/– mice that rejected B6 heart grafts or responded to synthetic self H‐2Kb peptides. Importantly, oligoclonal T‐cell expansions shared by different animals were detected in the peripheral T‐cell repertoire of transplanted TAP1–/– mice. Such public expansions were also induced in vitro by H‐2Kb peptides, suggesting that dominant class I peptides can induce preferential expansions of restricted T‐cell populations during rejection. Some of these public T‐cell expansions were also detected in transplanted mice even before in vitro stimulation with peptides, indicating that post‐transplantation expansion of these populations had occurred in vivo. The functional activity of these T‐cell populations awaits elucidation, as do the underlying mechanisms involved in the inflammatory autoreactive process, in TAP1–/– mice.
Effect of antisense oligonucleotide against mouse dentine matrix protein 1 on mineralization ability and calcium ions metabolism in odontoblast‐like cell line MDPC‐23
Authors: Pang J. L. , Wu B. L. , He W. X. , Zhang Y. Q. , Zhao H. P. , Xie Z. H. 
Published: May 2006

AbstractAim  To study the mineralization ability and the dynamic changes of intracellular and extracellular concentrations of calcium ions in the odontoblast‐like cell line MDPC‐23 affected by antisense oligonucleotide (AS‐ODN) against mouse dentine matrix protein 1 (DMP1).Methodology  The expression of DMP1 in MDPC‐23 cells was detected by an immunohistochemical method and its blocking outcome by the Western blot method. The alkaline phosphatase (ALP) activity, size and number of mineralized nodules, and the intracellular free ([Ca2+]if), total ([Ca2+]it) and the extracellular ([Ca2+]e) calcium ion concentrations in MDPC‐23 cells in the experimental group affected with AS‐ODN were compared with those in the control group (paired‐samples t‐test).Results  Dentine matrix protein 1 was stably expressed in a stable way in MDPC‐23 cells; the expression was only just detectable at 12 h and became negative after 24 h affected by AS‐ODN. Compared with the control groups, ALP activity of MDPC‐23 cells in the AS‐ODN group was decreased (P < 0.05), and both the number and size of mineralized nodules were smaller than those in the control group. [Ca2+]if in the AS‐ODN group increased and then decreased after 24 h. [Ca2+]it dropped substantially to the lowest point at 24 h (P < 0.01). [Ca2+]e increased before treatment for 24 h and then dropped, however, it was still higher than that of the control group.Conclusions  Antisense oligonucleotide against DMP1 could decrease mineralization ability and affect the intracellular and extracellular concentrations of calcium ions in MDPC‐23 cells. This would indicate that DMP1 regulates the metabolism and transportation of calcium ions in odontoblasts, and thus boosts dentine mineralization.
Nonsurgical treatment of extensive cyst‐like periapical lesion of endodontic origin
Authors: Soares J. , Santos S. , Silveira F. , Nunes E. 
Published: May 2006

AbstractAim  To report the repair of an extensive periapical lesion of endodontic origin, following nonsurgical treatment.Summary  Clinical and radiographic examination revealed an extensive periapical lesion related to tooth 22, extending from the distal surface of tooth 21 to the mesial surface of 26. The patient reported a previous history of dental trauma involving this quadrant and had been under orthodontic treatment for a year. Intraoral examination revealed an asymptomatic bony hard swelling, mainly confined to the palate. During root canal exploration irregular walls associated with 3 mm of apical calcification were noted. After apical patency was obtained 1 mL of bloody serous exudate was drained. Intracanal aspiration provided a further 2 mL of yellow serous exudate. Following biomechanical preparation, a dressing of calcium hydroxide with anaesthetic solution was applied and replaced four times over a period of 12 months. The clinical–pathological picture demonstrated resolution of the lesion during this period of time. The 14‐month clinical and radiographic examinations revealed normal bony contour and a significant resolution of the maxillary radiolucency.Key learning points  • Periapical lesions of endodontic origin may develop asymptomatically and become large.• Proper biomechanical preparation followed by calcium hydroxide medication renewed periodically represents a nonsurgical approach to resolve extensive inflammatory periapical lesions.
Multi‐level support for physical activity and healthy eating
Authors: Bull Sheana , Eakin Elizabeth , Reeves Marina , Kimberly Riley 
Published: May 2006

Aim.  This paper reports a study evaluating the relationship between social and community level supports and physical activity and dietary behaviours among a low‐income Latino population with multiple chronic conditions.Background.  With consistently lower physical activity than whites and documented nutritional deficiencies, Latinos in the United States of America represent a disproportionate share of the population with chronic illness. This pattern of health disparities is seen across countries, where there is a struggle to raise the health status of low‐income, immigrant and aboriginal communities. Social‐ecological theories of health behaviour stress the importance of considering social and community support for health behaviour, and represent a useful framework for considering ways to improve physical activity and nutrition for immigrant and aboriginal groups.Method.  We report here on data from a baseline assessment of 200 patients from a health clinic in the United States of America serving a low‐income, primarily Latino population. Participants were enrolled in Resources for Health, a randomized controlled trial to promote multi‐level support for chronic illness self‐management. Measures included self‐reported physical activity, dietary behaviour and multi‐level support for chronic illness management as well as demographic data. Baseline data reported on here were collected between February 2002 and September 2003.Findings.  Use of multi‐level supports (e.g. family, individual and healthcare provider) was statistically significantly associated with meeting physical activity guidelines and better dietary behaviours. Being female and having multiple chronic conditions were also associated with better dietary behaviour. These variables explained 20% of the variance in dietary behaviour.Conclusion.  Results support a social‐ecological approach for promoting healthy behaviour in this low‐income, primarily Latino sample with multiple chronic conditions. Addressing multiple levels of support for healthy behaviour is important in interventions to improve physical activity and diet, and nurses may be particularly well placed to address such issues for low‐income, aboriginal and immigrant patients with chronic conditions.
Power for detecting genetic divergence: differences between statistical methods and marker loci
Authors: RYMAN NILS , PALM STEFAN , ANDRÉ CARL , CARVALHO GARY R. , DAHLGREN THOMAS G. , JORDE PER ERIK , LAIKRE LINDA , LARSSON LENA C. , PALMÉ ANNA , RUZZANTE DANIEL E. 
Published: May 2006

AbstractInformation on statistical power is critical when planning investigations and evaluating empirical data, but actual power estimates are rarely presented in population genetic studies. We used computer simulations to assess and evaluate power when testing for genetic differentiation at multiple loci through combining test statistics or P values obtained by four different statistical approaches, viz. Pearson's chi‐square, the log‐likelihood ratio G‐test, Fisher's exact test, and an FST‐based permutation test. Factors considered in the comparisons include the number of samples, their size, and the number and type of genetic marker loci. It is shown that power for detecting divergence may be substantial for frequently used sample sizes and sets of markers, also at quite low levels of differentiation. The choice of statistical method may be critical, though. For multi‐allelic loci such as microsatellites, combining exact P values using Fisher's method is robust and generally provides a high resolving power. In contrast, for few‐allele loci (e.g. allozymes and single nucleotide polymorphisms) and when making pairwise sample comparisons, this approach may yield a remarkably low power. In such situations chi‐square typically represents a better alternative. The G‐test without Williams's correction frequently tends to provide an unduly high proportion of false significances, and results from this test should be interpreted with great care. Our results are not confined to population genetic analyses but applicable to contingency testing in general.
Evidence for isolation by time in the European eel (Anguilla anguilla L.)
Authors: MAES GREGORY E. , PUJOLAR J. M. , HELLEMANS B. , VOLCKAERT FILIP A. M. 
Published: May 2006

AbstractLife history traits of highly vagile marine species, such as adult reproductive success and larval dispersal, are strongly determined by oceanographic and climatic forces. Nevertheless, marine organisms may show restricted dispersal in time and space. Patterns of isolation by distance (IBD) have been repeatedly observed in marine species. If spawning time is a function of geographical location, temporal and spatial isolation, can easily be confounded or misinterpreted. In this study, we aimed at discriminating between various forces shaping the genetic composition of recruiting juveniles of the European eel (Anguilla anguilla L.). By controlling for geographical variation, we assessed temporal variation and tested for possible isolation by time (IBT) between recruitment waves within and between years. Using 12 polymorphic allozyme and six variable microsatellite loci, we show that genetic differentiation was low (FST = 0.01–0.002) and significant between temporal samples. Regression analysis between genetic and temporal distance, was consistent with a subtle interannual pattern of IBT. Our data suggest that the population dynamics of the European eel may be governed by a double pattern of temporal variance in genetic composition: (i) a broad‐scale IBT of spawning cohorts, possibly as a consequence of the large migration loop in anguillids and strong variance in annual adult reproductive contribution; and (ii) a smaller‐scale variance in reproductive success (genetic patchiness) within cohorts among seasonally separated spawning groups, most likely originating from fluctuating oceanic and climatic forces. The consistency of both mechanisms remains to be verified with fine‐scale analyses of both spawning/migrating aged adults and their offspring to confirm the stochastic/deterministic nature of the IBT pattern in eel.
Recency, range expansion, and unsorted lineages: implications for interpreting neutral genetic variation in the sharp‐tailed grouse (Tympanuchus phasianellus)
Authors: SPAULDING A. W. , MOCK K. E. , SCHROEDER M. A. , WARHEIT K. I. 
Published: May 2006

AbstractBoth current and historical patterns of variation are relevant to understanding and managing ecological diversity. Recently derived species present a challenge to the reconstruction of historical patterns because neutral molecular data for these taxa are more likely to exhibit effects of recent and ongoing demographic processes. We studied geographical patterns of neutral molecular variation in a species thought to be of relatively recent origin,Tympanuchus phasianellus (sharp‐tailed grouse), using mitochondrial control region sequences (CR‐I), amplified fragment length polymorphisms (AFLP), and microsatellites. For historical context, we also analysed CR‐I in all species ofTympanuchus. WithinT. phasianellus, we found evidence for restricted gene flow between eastern and western portions of the species range, generally corresponding with the range boundary ofT. p. columbianusandT. p. jamesi. The mismatch distribution and molecular clock estimates from the CR‐I data suggested that allTympanuchusunderwent a range expansion prior to sorting of mitotypes among the species, and that sorting may have been delayed as a result of mutation‐drift disequilibrium. This study illustrates the challenge of using genetic data to detect historical divergence in groups that are of relatively recent origin, or that have a history dominated by nonequilibrium conditions. We suggest that in such cases, morphological, ecological, and behavioural data may be particularly important adjuncts to molecular data for the recognition of historically or adaptively divergent groups.
Origin and genetic structure of feral rye in the western United States
Authors: BURGER JUTTA C. , LEE SKY , ELLSTRAND NORMAN C. 
Published: May 2006

AbstractFeral rye (Secale cereale) is a serious, introduced weed of dry land agricultural regions of the western United States. It closely resembles cultivated cereal rye (Secale cereale cereale L.) with the exception of having a shattering seed head. Feral rye may have originated from hybridization of cultivated rye with mountain rye, Secale strictum, as past studies of northern Californian populations suggest, or directly from volunteer cultivated rye. We characterized the genetic structure of feral rye populations across a broad geographical range and reexamined evidence for hybrid origin versus direct evolution from domesticated cultivars. Eighteen feral populations were examined from three climatically distinct regions in the western United States. Seven cultivars, four mountain rye accessions, and one wild annual relative (Secale cereale ancestrale) were included in our analysis as possible progenitors of feral rye. Individual plants were scored for 14 allozyme and three microsatellite loci. Estimates of genetic diversity in feral populations were relatively high compared to those of the possible progenitors, suggesting that the weed had not undergone a genetic bottleneck. Weed populations had no geographical structure at either a broad or a local scale, suggesting idiosyncratic colonization and gene‐flow histories at each site. Feral rye populations were no more closely related to mountain rye than cultivars were. They were, however, weakly clustered as a distinct lineage relative to cultivars. Our results do not support an interspecific hybrid origin for feral rye, but do suggest that the sampled populations of feral rye share a common ancestry that may explain its weedy nature.
Using nutritional indices to study LOX3‐dependent insect resistance
Authors: RAYAPURAM CBGOWDA , BALDWIN IAN T. 
Published: May 2006

ABSTRACTInduced resistance to biotic attackers is thought to be mediated by responses elicited by jasmonic acid (JA), a subset of which are lipoxygenase 3 (LOX3) dependent. To understand the importance of LOX3‐mediated insect resistance, we analysed the performance of Manduca sexta larvae on wild‐type (WT) and on isogenic Nicotiana attenuata plants silenced in NaLOX3 expression and JA signalling, and we used Waldbauer nutritional indices to measure the pre‐ and post‐ingestive effects. LOX3‐mediated defenses reduced larval growth, consumption and frass production. These defenses reduced how efficiently late‐instar larvae converted digested food to body mass (ECD). In contrast, LOX3‐mediated defenses decreased approximate digestibility (AD) in early instar larvae without affecting the ECD and total food consumption. Larvae of all instars feeding on defended WT plants behaviourally compensate for their reduced body mass by consuming more food per unit of body mass gain. We suggest that larvae feeding on plants silenced in NaLOX3 expression (as‐lox) initially increase their AD, which in turn enables them to consume more food in the later stages and consequently, to increase their ECD and efficiency of conversion of ingested food (ECI). We conclude that N. attenuata’s oxylipin‐mediated defenses are important for resisting attack from M. sexta larvae, and that Waldbauer nutritional assays reveal behavioural and physiological counter responses of insects to these plant defenses.
Switches in the minimum compressive stress direction induced by overpressure beneath a low‐permeability fault zone
Authors: Collettini C. , De Paola N. , Goulty N. R. 
Published: May 2006

AbstractThe Zuccale fault is a gently east‐dipping normal fault exposed on Elba. Its displacement of 7–8 km occurred from the mid‐Miocene to the Early Pliocene and the fault has been exhumed from a depth of 3–6 km. A complex hydrofracture system exposed in the footwall block consists of three orthogonal vein sets: two vertical sets trending N–S and E–W and one sub‐horizontal. The veins show a crack‐and‐seal texture and mutually cross‐cut each other. Throughout the period when the Zuccale fault was active, the regional stress field was extensional with the minimum principal stress oriented E–W, consistent only with the N–S trending set of vertical hydrofractures. We attribute the three sets of orthogonal fractures beneath the low‐permeability phyllosilicate‐rich fault core to switches in the minimum compressive stress direction induced by cyclic build‐up and release of overpressure.
Relative number of generations of hosts and parasites does not influence parasite local adaptation in coevolving populations of bacteria and phages
Authors: Morgan A. D. , Buckling A. 
Published: May 2006

Abstract
A potential consequence of host–parasite coevolution in spatially structured populations is parasite local adaptation: local parasites perform better than foreign parasites on their local host populations. It has been suggested that the generally shorter generation times of parasites compared with their hosts contributes to parasites, rather than hosts, being locally adapted. We tested the hypothesis that relative generation times of hosts and parasites affect local adaptation of hosts and parasites, using the bacterium Pseudomonas fluorescens and a lytic phage as host and parasite, respectively. Generation times were not directly manipulated, but instead one of the coevolving partners was regularly removed and replaced with a population from an earlier time point. Thus, one partner underwent more generations than the other. Manipulations were carried out at both early and later periods of coevolutionary interactions. At early stages of coevolution, host and parasites that underwent relatively more generations displayed higher levels of resistance and infectivity, respectively. However, the relative number of generations that bacteria and phages underwent did not change the level of local adaptation relative to control populations. This is likely because generalist hosts and parasites are favoured during early stages of coevolution, preventing local adaptation. By contrast, at later stages manipulations had no effect on either average levels of resistance or infectivity, or alter the level of local adaptation relative to the controls, possibly because traits other than resistance and infectivity were under strong selection. Taken together, these data suggest that the relative generation times of hosts and parasites may not be an important determinant of local adaptation in this system.