bluuebunny/crossref_metadata_2025_split huggingface dataset:
Liposome/DNA complexes coated with biodegradable PLA improve immune responses to plasmid encoding hepatitis B surface antigen
Authors: Bramwell Vincent W. , Eyles Jim E. , Somavarapu Satyanarayana , Alpar H. Oya 
Published: March 2003

SummaryWe hypothesized that the addition of polymer to the surface of liposome/DNA complexes may potentially enhance in vivo delivery of plasmid DNA to antigen‐presenting cells and thereby facilitate enhanced immune responses to encoded protein. BALB/c mice were immunized subcutaneously or intramuscularly three times with a total of 50 µg of the plasmid pRc/CMV‐HBs(S) (ayw subtype) encoding for the hepatitis B surface antigen. We measured transgene‐specific total immunoglobulin G (IgG), IgG2a, IgG2b and IgG1 antibody responses as well as splenocyte and T‐cell proliferation and cytokine production upon re‐stimulation following immunization. Modification of lipid/DNA complexes by the polymer precipitation method used here for the addition of poly(d,l‐lactic acid) was found to be consistently and significantly more effective than either unmodified liposomal DNA or naked DNA in eliciting transgene‐specific immune responses to plasmid‐encoded antigen when administered by the subcutaneous route. In addition, the polymer‐modified formulations delivered by this route were more effective than naked DNA delivered by the intramuscular route in inducing antibody responses (n=5, P<0·03). Our observations provide ‘proof of principle’ for the use of these multicomponent formulations, which offer potential for manipulation and increased transfection efficiency in vivo for the purposes of genetic immunization.
Evidence from twins for acquired cellular immune hyperactivity in type 1 diabetes
Authors: Petrovsky Nikolai , Kyvik Kirsten O. , Bonnevie‐Nielsen Vagn , Beck‐Nielsen Henning , Green Anders , Harrison Leonard C. 
Published: March 2003

SummaryType 1 diabetes has been associated with an increased frequency of activated T cells and T‐cell hyperactivity to non‐specific and disease‐specific stimuli including the islet autoantigen glutamic acid decarboxylase 65 (GAD). To address whether T‐cell hyperactivity is genetic or acquired we measured whole blood cytokines in vitro in response to GAD or tetanus in 18 identical twin pairs, nine discordant for type 1 diabetes. In addition, the activity of 2′, 5′ oligoadenylate synthetase (OAS) in blood mononuclear cells was measured as a marker of viral infection. Interleukin‐2 (IL‐2) basally and IL‐2 and interferon‐γ (IFN‐γ) in response to GAD, were detected more frequently and at higher levels in diabetic compared to non‐diabetic twins. IL‐10 was not different between groups. OAS activity was increased in diabetic compared to non‐diabetic twins and showed a correlation with basal IL‐2 and GAD‐stimulated IFN‐γ and IL‐10. These findings suggest that T‐cell hyperactivity in type 1 diabetes is an acquired trait and could reflect persisting virus expression.
Immunological basis of the development of necrotic lesions following Mycobacterium avium infection
Authors: Flórido Manuela , Cooper Andrea M. , Appelberg Rui 
Published: March 2003

SummaryNormal C57BL/6 mice infected with 106 colony‐forming units of a highly virulent strain of Mycobacterium avium developed a progressive infection characterized by loss of T cells from the tissues and infiltration with high numbers of heavily infected macrophages. In contrast, when C57BL/6 mice were infected with 102 colony‐forming units of the same strain they retained T cells and T‐cell reactivity in the tissues, and granulomas evolved into large masses that, at 4 months of infection, exhibited central necrosis. The development of these necrotic lesions did not occur in nude mice, nor in mice genetically deficient in CD4, interleukin‐12 (IL‐12) p40, interferon‐γ (IFN‐γ) and CD40 and were reduced in mice deficient in CD54 or IL‐6. They were less numerous but bigger in mice deficient in IL‐10 or the inducible nitric oxide synthase, correlating with the increased resistance to mycobacterial proliferation of these strains as compared to control mice. The appearance of necrosis was not affected in mice deficient in CD8α, T‐cell receptor δ, tumour necrosis factor receptor p55, and perforin, nor was it affected in mice over‐expressing bcl2. The appearance of necrosis could be prevented by administering antibodies specific for CD4, IL‐12p40, or IFN‐γ from the second month of infection when organized granulomas were already found. Our results show that the immunological mediators involved in the induction of protective immunity are also major players in the immunopathology associated with mycobacteriosis.
Production of interleukin‐13 by human dendritic cells after stimulation with protein allergens is a key factor for induction of T helper 2 cytokines and is associated with activation of signal transducer and activator of transcription‐6
Authors: Bellinghausen Iris , Brand Pia , Böttcher Ingo , Klostermann Bettina , Knop Jürgen , Saloga Joachim 
Published: March 2003

SummaryDendritic cells (DC) are able to induce not only T helper 1 (Th1) but also Th2 immune responses after stimulation with allergens. While DC‐derived interleukin (IL)‐12 and IL‐18 are the key factors for the induction of Th1 cells, early signals being involved in Th2 differentiation are less well characterized so far. To analyse such early signals we used an antigen‐specific setting with CD4+ T cells from atopic donors stimulated in the presence of autologous mature DC, which were pulsed with different allergen doses. The addition of increasing amounts of allergen during DC maturation with tumour necrosis factor‐α, IL‐1β and prostaglandin E2 resulted in enhanced secretion of IL‐6 and IL‐12 by DC followed by increased production of Th1 (interferon‐γ; IFN‐γ) as well as Th2 (IL‐4, IL‐5) cytokines by CD4+ T cells. The coculture of allergen‐treated DC and CD4+ T cells also led to a dose‐dependent expression of active signal transducer and activator of transcription‐6 (STAT6), which was visible already after 1 hr. Additionally, rapid phosphorylation of STAT6 was seen in immature DC after stimulation with allergens but not with lipopolysaccharide or human serum albumin. STAT6 phosphorylation was associated with the production of IL‐13 by DC. The addition of neutralizing anti‐IL‐13 antibodies during maturation of DC inhibited STAT6 phosphorylation in CD4+ T cells as well as the production of IL‐4, and to a lesser extent of IL‐5, while IFN‐γ production was not affected. Addition of exogenous IL‐13 enhanced mainly the secretion of IL‐4. Taken together, DC‐derived IL‐13, which is released after exposure to allergens appears to be one of the critical factors for DC to acquire the capability to induce Th2 cytokine production.
Dendritic cells recruited to the lung shortly after intranasal delivery of Mycobacterium bovis BCG drive the primary immune response towards a type 1 cytokine production
Authors: Lagranderie Micheline , Nahori Marie‐Anne , Balazuc Anne‐Marie , Kiefer‐Biasizzo Hélène , Lapa E Silva Jose‐Roberto , Milon Geneviève , Marchal Gilles , Vargaftig Boris B. 
Published: March 2003

SummaryWe showed in a previous study that the intranasal (i.n) delivery of bacille Calmette–Guérin (BCG) to BP2 mice (H‐2q) inhibits eosinophilia and bronchial hyperreactivity in a mouse model of asthma. The present work has been performed to characterize the leucocyte lineages recruited to the lungs of mice after i.n. delivery of BCG and potentially involved in the polarization of T lymphocytes. The different antigen‐presenting cells (APC) recruited to bronchoalveolar lavage (BAL) and to lung tissue of mice shortly after the delivery of BCG were analysed in parallel as well as their capacity to drive the immune response towards a T helper type 1 cytokine production. Alveolar macrophages (AM) from the BAL were CD11c+, F4/80+ and CD11b−, and in the lung tissue two major populations of potential APC were detected: one CD11c−, F4/80+, CD11b+ and I‐Aq− was identified as interstitial macrophages (IM) and a second expressing CD11c+ and I‐Aq+ antigens, negative for CD11b and F4/80 markers as leucocytic dendritic cells (DC). Freshly isolated DC up‐regulated CD11b and CD40 antigens after overnight culture, but remained negative for CD8α antigen, suggesting a myeloid origin. Lung DC which produced high amount of interleukin (IL)‐12 were potent inducers of naive CD4+ T lymphocyte priming, as assessed by interferon‐γ (IFN‐γ) production by these naive CD4+ T cells. Lung explants recovered long term after BCG delivery produced sustained levels of IFN‐γ. Our results suggest that AM and particularly DC by secreting IL‐12 shortly after BCG delivery induce the long‐term persistence of IFN‐γ‐secreting T cells percolating in BCG‐loaded lung tissue.
Trust, power and interorganizational information systems: the case of the electronic trading community TransLease
Authors: Allen David K. , Colligan David , Finnie Andrew , Kern Thomas 
Published: March 2003

Abstract.This paper focuses on Cap Gemini’s electronic commerce system, TransLease. TransLease is an interorganizational information system (IOS), which facilitates electronic commerce between motor vehicle leasing and repair companies. During our investigation, the system was used by approximately 1000 repair agents working for seven of the UK’s leading vehicle leasing and contract hire companies. This system was originally developed by AT&T and acquired by Cap Gemini in July 1998. At the time of acquisition, the system was seen as being of high strategic value, although it was also seen as underperforming. This paper reports the results of an action research project, which formed one element of the process by which Cap Gemini investigated the former problem. In the paper, TransLease is described as a complex electronic community, dependent upon the existence of symbiotic relationships. As such, the problems that the system users and developers experienced can be attributed to factors that impeded the mutual benefit accruing from participation in the system. The efficacy of the terms of exchange and the degree to which participants mutually benefit through electronic interaction is determined by the complex interplay of a number of relational and organizational factors. The research therefore illustrates the importance of the ‘soft’ organizational issues in IOS management and development, and suggests a conceptual model of the factors relevant in this case. At the time of this study, TransLease was still in the early stages of its life cycle, having only been available in the marketplace for approximately 18 months. During this time, through recognizing the complex problems and issues detailed in this paper, Cap Gemini accordingly redressed the way in which the system was managed and maintained. TransLease is now seen as having matured into a highly successful example of an IOS – a view reflected by its position as market leader in the industry. As this paper will show, the key to improving the existing service has been the emphasis Cap Gemini now places on managing the ‘soft’ aspects of the electronic community.
‘It’s lots of bits of paper and ticks and post‐it notes and things . . .’: a case study of a rapid application development project
Authors: Beynon‐Davies Paul , Mackay Hugh , Tudhope Douglas 
Published: March 2003

Abstract.This paper reports an in‐depth case study of a rapid application development (RAD) project. RAD is a recent information systems development method noted for its high levels of user involvement and use of iterative prototyping. The paper develops a model of the core features of RAD gleaned from literature such as that published on the dynamic systems development method (DSDM). We report an ethnographic study of a RAD project and use this case material to contrast the theory with the practice of RAD. We conclude the paper with a consideration of a number of possible revisions to the prescriptions of RAD and also discuss the role of RAD within the broader context of IS development.‘It’s lots of bits of paper and ticks and post‐it notes and things . . . you’ll get to understand it, it’s not that bad really’. A RAD team member
The significance of context in information systems and organizational change
Authors: Avgerou Chrisanthi 
Published: March 2003

Abstract.This paper argues that it is of crucial importance that information systems (IS) research and practice associates technology innovation with the context within which it is embedded. It identifies three principles to be followed in order to address the contextual processes involved in IS implementation: first, technology innovation should be considered in relation to socio‐organizational change; second, analysis should consider not only the local organizational, but also the national and international context; and third, analysis should consider both the technical/rational decisions and actions involved in the innovation process and the cultural, social and cognitive forces of such a process. These principles are demonstrated with the analysis of a case study of organizational reform in Cyprus.
Characterization of the Sialokinin I gene encoding the salivary vasodilator of the yellow fever mosquito, Aedes aegypti
Authors: Beerntsen B. T. , Champagne D. E. , Coleman J. L. , Campos Y. A. , James A. A. 
Published: March 2003

AbstractThe gene encoding sialokinin I, the principal vasodilatory peptide of Aedes aegypti, has been isolated and characterized. Degenerate oligonucleotide primers based on peptide amino acid sequence were used to amplify a gene fragment from messenger RNA (mRNA) isolated from female salivary glands. The amplification product was used to probe a salivary gland complementary DNA (cDNA) library, and a number of corresponding cDNAs were isolated and their primary sequence determined. Analysis of the conceptual translation product of a 406‐bp cDNA indicates that sialokinin I is expressed as a preprosialokinin and is subsequently post‐translationally processed to the active peptide. Northern analysis revealed a 490‐bp transcription product expressed exclusively in female salivary glands, and hybridization in situ of probes to RNA in whole tissues localized gene expression to the medial lobe of female salivary glands. Screening of an Ae. aegypti genomic library with the cDNA resulted in the isolation of a clone containing the gene, designated Sialokinin I (Sia I). Comparison of the cDNA with the genomic clone reveals two introns of 62 bp and 833 bp. Primer extension analysis showed that several transcription initiation sites are present. Southern analysis of genomic DNA shows that Sia I is most probably a single‐copy gene. Similarities of the Sia I gene product with other genes are confined to the region encoding the active decapeptide.
Intron insertion as a phylogenetic character: theengrailedhomeobox of Strepsiptera does not indicate affinity with Diptera
Authors: Rokas A. , Kathirithamby J. , Holland P. W. H. 
Published: March 2003

AbstractThe phylogenetic relationships of the order Strepsiptera are unclear. Affiliation to Coleoptera has been proposed, however this implies that dipteran halteres and strepsipteran haltere‐like organs evolved convergently. An alternative is a sister group relationship with Diptera. In this case, halteres could be homologous but a radical homeotic mutation may have switched their position to the Strepsipteran mesothorax. Ribosomal DNA sequence analysis has been used to support Dipteran affiliation, although this is controversial. Here we investigate the potential of an intron insertion site as a phylogenetic character. We find that theenhomeobox gene of the strepsipteranStichotrema dallatorreanumlacks a derived intron insertion shared by representatives of Diptera and Lepidoptera. We argue against a close affiliation between Strepsiptera and Diptera.
Cloning and expression of a novel juvenile hormone‐metabolizing epoxide hydrolase during larval–pupal metamorphosis of the cabbage looper, Trichoplusia ni
Authors: VanHook Harris S. , Thompson D. Marin , Linderman R. J. , Tomalski M. D. , Roe R. M. 
Published: March 2003

AbstractA full‐length cDNA encoding for a microsomal juvenile hormone (JH)‐metabolizing epoxide hydrolase (TmEH‐1) was isolated from a cDNA library constructed from fat body of last stadium (wandering) cabbage loopers, Trichoplusia ni, at the exact developmental time of maximum JH epoxide hydrolase activity. TmEH‐1 was 1887 base pairs in lenght with a 1389 base pair open reading frame encoding 463 amino acids. Amino acid sequence analysis showed that TmEH‐1 was most similar to and contained the exact catalytic triad (Asp‐226, Glu‐403 and His‐430) found in microsomal epoxide hydrolases. TmEH‐1‐specific message was present along with JH III epoxide hydrolase activity in fat body in feeding (days 1 and 2) and wandering (day 3) larvae with the peak in message level preceding the peak in JH epoxide hydrolase activity by 1 day. When TmEH‐1 was expressed in baculovirus‐infected Spodoptera frugiperda cells, a 46,000 molecular weight protein appeared on SDS‐PAGE which corresponded to the predicted size coded by the TmEH‐1 message and which was positively correlated with increases in JH III epoxide hydrolase activity above that of wild‐type controls. In subcellular distribution studies, 58% of the juvenile hormone III epoxide hydrolase activity was in the insoluble fractions. Baculovirus expressed TmEH‐1 demonstrated a higher specific activity for JH III as compared to the general EH substrates, cis‐ and trans‐stibene oxide. Southern blot analyses suggested that multiple epoxide hydrolase genes are present in T. ni.
Cloning and analysis of a cecropin gene from the malaria vector mosquito, Anopheles gambiae
Authors: Vizioli J. , Bulet P. , Charlet M. , Lowenberger C. , Blass C. , Müller H.‐M. , Dimopoulos G. , Hoffmann J. , Kafatos F.C. , Richman A. 
Published: March 2003

AbstractParasites of the genus Plasmodium are transmitted to mammalian hosts by anopheline mosquitoes. Within the insect vector, parasite growth and development are potentially limited by antimicrobial defence molecules. Here, we describe the isolation of cDNA and genomic clones encoding a cecropin antibacterial peptide from the malaria vector mosquito Anopheles gambiae. The locus was mapped to polytene division 1C of the X chromosome. Cecropin RNA was induced by infection with bacteria and Plasmodium. RNA levels varied in different body parts of the adult mosquito. During development, cecropin expression was limited to the early pupal stage. The peptide was purified from both adult mosquitoes and cell culture supernatants. Anopheles gambiae synthetic cecropins displayed activity against Gram‐negative and Gram‐positive bacteria, filamentous fungi and yeasts.
Sperm‐mediated transformation of the honey bee, Apis mellifera
Authors: Robinson K. O. , Ferguson H. J. , Cobey S. , Vaessin H. , Smith B. H. 
Published: March 2003

AbstractOur primary objective was to identify techniques to transform the genome of the honey bee (Apis mellifera) with foreign DNA constructs. The strategy we adopted was to linearize foreign DNA and introduce it with sperm during the instrumental insemination of virgin queen honey bees. We analysed extracts from larvae within the same cohort and isolated the predicted fragment by means of PCR amplification of genomic DNA. Larvae that carried the construct also expressed the introduced DNA. We propagated several transgenic lines for up to three generations, which demonstrates its heritability. Once carried by a queen, the construct can be detected in that queen’s larvae over several months. However, there was no evidence of integration of the construct, at least as determined by genomic Southern analysis. Nevertheless, this demonstrates the general viability of the technique for introduction of DNA, and it should be augmented by further use of transposable elements that enhance integration.
Amino acids in SRS1 and SRS6 are critical for furanocoumarin metabolism by CYP6B1v1, a cytochrome P450 monooxygenase
Authors: Chen J.‐S. , Berenbaum M. R. , Schuler M. A. 
Published: March 2003

AbstractCYP6B1v1 is the principal cytochrome P450 monooxygenase (P450) that detoxifies dietary furanocoumarins in the guts of Papilio polyxenes, the black swallowtail caterpillar. Sequence alignments and structure comparisons of CYP6B1v1 with the mouse CYP2A5 and bacterial CYP102 proteins, which are also capable of metabolizing the linear furanocoumarin xanthotoxin (8‐methoxypsoralen), suggested that Phe116, His117, Val368 and Phe484 might be active site residues. In a homology model developed for CYP6B1v1, the side chains of Phe116 and His117 located in the B′‐C loop of SRS1 are predicted to be positioned above the haem plane, while the side chain of Phe484 located in SRS6 is predicted near the entrance of the catalytic pocket. Site‐directed mutagenesis of residues Phe116, His117 and Phe484 indicated that these residues represent several of those that determine this protein’s stability and substrate specificity. Whereas all aromatic mutants of Phe116 and Phe484 generated CO‐difference spectra with maxima at 450 nm indicative of correctly configured monooxygenases, aromatic mutants of Phe116 exhibited reduced reactivities toward some furanocoumarins and aromatic mutants of Phe484 eliminated all reactivities toward furanocoumarins. All single and double aliphatic mutants of Phe116, His117 and Phe484 and aromatic mutants of His117 generated carbon monoxide (CO) difference spectra with maxima at 420 nm (P420) indicative of incorrectly configured monooxygenases. These studies define residues Phe116, His117 and Phe484 as determinants of this insect P450’s catalytic site integrity and residues Phe116 and Phe484 as determinants of its substrate specificity. Conservation of Phe116 and His117 in an array of lepidopteran CYP6B proteins implies that these amino acids serve a similar function in other monooxygenases of the insect CYP6B subfamily.
Hemolin gene silencing by ds‐RNA injected into Cecropia pupae is lethal to next generation embryos
Authors: Bettencourt R. , Terenius O. , Faye I. 
Published: March 2003

AbstractThere is increasing evidence of an intimate connection between participants in the innate immune system and in development. Molecules involved in the determination of dorso‐ventral polarity in Drosophila have related counterparts in the signalling pathways for immune gene activation in both insects and mammals. Hemolin from the Giant silkmoth, Hyalophora cecropia, identified as a bacteria‐inducible molecule and a member of the immunoglobulin superfamily, is present as protein and transcripts in oocytes and embryos. We used RNA interference (RNAi) to investigate H. cecropia gene function in vivo and demonstrated that Hemolin is crucial for the normal development of embryos. When RNAi‐females were mated, no larvae emerged from their eggs and when dissected, the eggs revealed malformed embryos. Western blot analysis confirmed the lack of Hemolin gene products. We conclude that Hemolin is necessary for development, since the silencing of Hemolin gene expression leads to embryonic lethality.