bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reactivation of latent tuberculosis by an inhibitor of inducible nitric oxide synthase in an aerosol murine model
Authors: Botha Tania , Ryffel Bernhard 
Published: March 2003

SummaryExposure to Mycobacterium tuberculosis results in clinical tuberculosis only in a small percentage of healthy individuals. In most instances the bacilli are controlled by the immune system and survive in a latent state within granuloma. Immunosuppression, however, may result in reactivation of infection, resulting in clinical disease. Using a low‐dose aerosol infection (30 colony‐forming units) in mice, we describe a short‐duration model for studying spontaneous and drug‐induced reactivation of anti‐tuberculous drug‐treated, latent tuberculosis infection. Although a 4‐week treatment with rifampicin and isoniazid reduced the number of bacilli to undetectable levels, the infection spontaneously reactivated following therapy. By contrast, an 8‐week treatment period induced a state of latent infection, requiring immunosuppression to reactivate infection. Finally, a 12‐week treatment period eliminated the bacilli completely and aminoguanidine did not induce reactivation of infection. In view of the fact that therapy in the selected protocol reduces the mycobacterial load to undetectable levels, the data suggest that an 8‐week treatment period is necessary and sufficient to mount protective immunity in mice.
Tumour necrosis factor‐α (TNF‐α) transgene‐expressing dendritic cells (DCs) undergo augmented cellular maturation and induce more robust T‐cell activation and anti‐tumour immunity than DCs generated in recombinant TNF‐α
Authors: Zhang Weidong , Chen Zhuang , Li Fang , Kamencic Huse , Juurlink Bernie , Gordon John R. , Xiang Jim 
Published: March 2003

SummaryTumour antigen presentation by dendritic cells (DCs) to T cells in lymphoid organs is crucial for induction of anti‐tumour immune responses. It has been previously reported that tumour necrosis factor‐α (TNF‐α) is required for DC activation and subsequent induction of optimal immune responses, and thus DCs for anti‐tumour vaccination are often generated by culture in exogenous TNF‐α. In the present study, we investigated the effect on anti‐tumour immunity of vaccination with Mut1 tumour peptide‐pulsed DCs engineered to express a TNF‐α transgene. Our data shows that transfection of DCs with recombinant adenovirus AdV‐TNF‐α resulted in greater maturation of the DCs than occurred with control DCs cultured in exogenous TNF‐α, as determined by up‐regulated expression of pro‐inflammatory cytokines (e.g. interleukins 1β and 18), chemokines [e.g. interferon‐γ‐inducible protein‐10 and macrophage inflammatory protein‐1β (MIP‐1β)], the CC chemokine receptor CCR7, and immunologically important cell surface molecules (CD40, CD86 and intercellular adhesion molecule‐1). These transgenic DCs stimulated stronger allogeneic T‐cell responses in vitro and T‐cell activation in vivo; displayed 2·4‐fold enhanced chemotactic responses to the MIP‐3βin vitro (P<0·05); and, perhaps most importantly, trafficked into the draining lymph nodes dramatically (seven‐fold, P<0·01) more efficiently than the control DCs. Our data also demonstrate that vaccination of mice with Mut1 peptide‐pulsed, AdV‐TNF‐α‐transfected DCs stimulated more efficient in vitro Mut1‐specific CD8+ cytotoxic T‐cell responses and solid tumour immunity in vivo, when compared to the in vitro TNF‐α‐cultivated DCs. Thus, DCs engineered to secrete TNF‐α may offer a new strategy in DC cancer vaccines.
The effect of transaction costs on the decision to replace ‘off‐the‐shelf’ software: the role of software diffusion and infusion
Authors: Castner Grant , Ferguson Colin 
Published: March 2003

Abstract.This study examines the extent to which software diffusion and infusion affect the decision to replace ‘off‐the‐shelf’ software, using the example of spreadsheet software. Transaction cost economics motivates the propositions that higher levels of software diffusion and higher levels of software infusion act as disincentives on the firm’s decision to upgrade or change off‐the‐shelf software. Our focus on software diffusion and infusion extends previous research that only examined hardware infusion and diffusion. Results from the study, using a survey, newsgroups and interviews, generally support the propositions and show that the more software is diffused and infused into a firm, the less likely it is to be changed or upgraded. More specifically, the results also show that, while software infusion acts directly to reduce the likelihood of software replacement, software diffusion only affects it indirectly through its effect on infusion.
Reflections on information systems practice, education and research: 10 years of the Information Systems Journal
Authors: Avison David , Fitzgerald Guy , Powell Philip 
Published: March 2003

Abstract.This paper celebrates the 10‐year anniversary of the Information Systems Journal (ISJ) and the Editors reflect on the papers that have been published over that period and the changes that have occurred in the discipline of information systems. In the opening paper of ISJ, we suggested that the ‘launch of a new journal in information systems prompts thought and debate concerning the state of the subject area and some contemplation of its past and future’. We discussed three areas of this ‘not‐yet‐established discipline’: practice, education and research. In this follow‐up paper, we forgo our convention of ISJ editors not publishing in the Journal. We examine the issues raised in the first paper and consider what has happened in the intervening years as charted in the ISJ. The overview is necessarily selective, probably Anglocentric (with, perhaps, a slight Francophile tinge), sometimes downright opinionated, as well as over‐estimating, perhaps, the contribution of one particular IS journal.
Green fluorescent protein as a genetic marker in transgenic Aedes aegypti
Authors: Pinkerton A. C. , Michel K. , O'Brochta D. A. , Atkinson P. W. 
Published: March 2003

AbstractWe report here the use of the enhanced green fluorescent protein (EGFP) from the jellyfish, Aequorea victoria, as a genetic marker for the genetic transformation of mosquitoes. The EGFP gene, under the control of the actin5C promoter of Drosophila melanogaster was inserted into the Hermes transposable element. Preblastoderm embryos of a wild‐type strain of the yellow fever mosquito, Aedes aegypti, were microinjected with this plasmid, together with a helper plasmid containing the Hermes transposase placed under the control of the D. melanogaster hsp70 promoter. Somatic EGFP expression was observed during early instars in approximately one‐half of all G0 individuals. Two G1 individuals arising from a G0 female displayed high levels of EGFP gene expression during all stages of development. EGFP was transmitted in a Mendelian fashion to the G2 and G3 generations and molecular analysis confirmed the presence of the Hermes[actin5C:EGFP] gene in these insects. These results clearly demonstrate that EGFP can be used as an effective genetic marker in wild‐type Ae. aegypti and most likely in other mosquito species as well.
Long PCR improvesWolbachiaDNA amplification:wspsequences found in 76% of sixty‐three arthropod species
Authors: Jeyaprakash A. , Hoy M. A. 
Published: March 2003

AbstractBacteria belonging to the genusWolbachiaare associated with a variety of reproductive anomalies in arthropods. Allele‐specific polymerase chain reaction (= Standard PCR) routinely has been used to amplifyWolbachiaDNA from arthropods. While testing the two‐spotted spider miteTetranychus urticaeand other arthropods known to be infected withWolbachia, Standard PCR frequently produced false negatives, perhaps because the DNA from the arthropod host interfered with amplification byTaqDNA polymerase. Long PCR, which uses two enzymes (TaqandPwo), consistently amplifiedWolbachiaDNA and a sensitivity analysis indicated that Long PCR was approximately six orders of magnitude more sensitive than Standard PCR in amplifying plasmid DNA spiked into insect genomic DNA. A survey indicated that 76% of sixty‐two arthropod species and two subspecies in thirteen orders tested positive for theWolbachia wspsequence by Long PCR, which is considerably higher than the rate of 16.9% obtained previously for theftsZsequence using Standard PCR (Werren, J.H., Windsor, D. and Gao, L. (1995a)Proc R Soc Lond B262: 197–204). A subsample of Long PCR products from fourteen arthropod species and two subspecies were sequenced, both directly and after cloning. Two A‐ and eleven B‐Wolbachiastrains were detected and theirwspsequences displayed a maximum of 23.7% sequence divergence at this locus. Two new groups (named Fus and Ten) were identified in addition to nineteen reported earlier (Zhou, W., Rousset, F. and O’Neill, S.L. (1998)Proc R Soc Lond B265: 1–7;van Meer, M.M.M., Witteveldt, J. and Stouthamer, R. (1999)Insect Mol Biol8: 399–408), because they displayed more than 2.5% sequence divergence from otherWolbachia wspsequences. PCR products from seventeen of twenty‐nine (59%) arthropod species analysed could not be sequenced directly due to apparent infection by multipleWolbachiastrains. Thewspsequences cloned from two such species (Plutella xylostellaandTrichoplusia ni) indicated both A‐ and B‐Wolbachiawere present in a single individual. Hence, superinfection also may be more widespread than the 1.2% incidence previously estimated.
Genetic mapping of two loci affecting DDT resistance in the malaria vector Anopheles gambiae
Authors: Ranson H. , Jensen B. , Wang X. , Prapanthadara L. , Hemingway J. , Collins F. H. 
Published: March 2003

AbstractResistance to the insecticide DDT in the mosquito vectors of malaria has severely hampered efforts to control this disease and has contributed to the increase in prevalence of malaria cases seen in recent years. Over 90% of the 300–500 million annual cases of malaria occur in Africa, where the major vector is Anopheles gambiae. DDT resistance in the ZAN/U strain of An. gambiae is associated with an increased metabolism of the insecticide, catalysed by members of the glutathione S‐transferase (GST) enzyme family, but the molecular mechanism underlying this metabolic resistance is not known. Genetic crosses show that resistance is autosomal and semidominant. We have used microsatellite markers to identify two quantitative trait loci (QTL), which together explain over 50% of the variance in susceptibility to DDT in the ZAN/U strain of An. gambiae. The first locus, rtd1, is on chromosome 3 between markers H341 and H88 and has a recessive effect with respect to susceptibility. The second locus, rtd2 is on chromosome 2L, close to marker H325 and has an additive genetic effect. The markers flanking these two QTL have been physically mapped to An. gambiae polytene chromosomes. They do not coincide with any of the GST genes that have been cloned and mapped in this species. Characterization of these QTL will lead to a clearer understanding of the mechanisms of metabolic resistance to DDT.
Glucosamine:fructose‐6‐phosphate aminotransferase: gene characterization, chitin biosynthesis and peritrophic matrix formation in Aedes aegypti
Authors: Kato N. , Dasgupta R. , Smartt C. T. , Christensen B. M. 
Published: March 2003

AbstractGlucosamine:fructose‐6‐phosphate aminotransferase (GFAT) catalyses the formation of glucosamine 6‐phosphate and is the first and rate‐limiting enzyme of the hexosamine biosynthetic pathway. The final product of the hexosamine pathway, UDP‐N‐acetyl glucosamine, is an active precursor of numerous macromolecules containing amino sugars, including chitin in fungi and arthropods. Chitin is one of the essential components of insect cuticle and peritrophic matrix. The peritrophic matrix is produced in the midgut of mosquitoes in response to bloodfeeding, and may affect vector competence by serving as a physical barrier to pathogens. It is hypothesized that GFAT plays a regulatory role in biosynthesis of chitin and peritrophic matrix formation in insects. We cloned and sequenced the GFAT gene (AeGfat‐1) and its 5′ regulatory region from Aedes aegypti. There is no intron in AeGfat‐1 and there are two potential transcription start sites. AeGfat‐1 cDNA is 3.4 kb in length and its putative translation product is 75.4 kDa. The amino acid sequence of GFAT is highly conserved in lower and higher eukaryotes, as well as in bacteria. AeGfat‐1 message is constitutively expressed but is gradually up‐regulated in the midgut after bloodfeeding. The putative regulatory region of the gene contains the ecdysone response element, E74, and Broad complex motifs, similar to what is found in the glutamine synthetase gene in Ae. aegypti. Results suggest that Ae. aegypti GFAT‐1 may have a regulatory role in chitin biosynthesis and peritrophic matrix formation, and probably is under the regulation of ecdysteroids.
Ribosomal ITS2 sequence data for Anopheles maculipennis and An. messeae in northern Greece, with a critical assessment of previously published sequences
Authors: Linton Y.‐M. , Samanidou‐Voyadjoglou A. , Harbach R. E. 
Published: March 2003

AbstractDNA sequences were generated for eight specimens of the Anopheles maculipennis complex from Florina in NW Greece, and identified to species on the basis of comparison with ITS2 sequences for members of the complex already in GenBank. The sequences revealed the presence of An. maculipennis and An. messeae in Florina. Problems with sequence reliability and accessibility of sequences generated in earlier studies of Palaearctic members of the complex are discussed.
A comparative study of the removal of smear layer by three endodontic irrigants and two types of laser
Authors: Takeda F. H. , Harashima T. , Kimura Y. , Matsumoto K. 
Published: March 2003

Aim The effects of three endodontic irrigants and two types of laser on a smear layer created by hand instrumentation were evaluated in vitro in the middle and apical thirds of root canals.Methodology Sixty human mature extracted mandibular premolar teeth with a single root canal and a closed apex were distributed randomly into five groups of 12 teeth each. Whilst cleaning and shaping up to a size 60 master apical file with a step‐back technique, the root canals were irrigated with 3 mL of 5.25% NaOCL and 3% H2O2, alternately, between each file size. Group 1 (G1) were control specimens that were irrigated with a final flush of 17% EDTA. The teeth in group 2 (G2) were irrigated with a final flush of 6% phosphoric acid, and group 3 (G3) with 6% citric acid. In the specimens of group 4 (G4) the root canals were irradiated with a carbon dioxide (CO2) laser, and specimens of group 5 (G5) were irradiated using an Er:YAG laser. The teeth were split longitudinally and prepared for examination by scanning electron microscopy.Results Control specimens (G1) showed clean root‐canal walls with open dentinal tubules in the middle one‐third, but in some specimens thick smear layer was observed in the apical one‐third.Specimens irrigated with a final flush of 6% phosphoric acid (G2) or 6% citric acid (G3) were cleaner than with 17% EDTA, showing very clean root canal surfaces in the middle one‐third but in the apical one‐third the smear layer was not completely removed, especially at the openings of the dentinal tubules. The specimens irradiated with the CO2 laser (G4) showed clean root‐canal walls with the smear layer absent, charred, melted, recrystallized and glazed in both middle and apical thirds. The root‐canal walls of the specimens irradiated with the Er:YAG laser (G5) revealed an absent smear layer with open dentinal tubules in the middle and apical thirds. Statistical analysis showed no significant difference in the cleanliness of root‐canal wall between G1 and G2, and G1 and G3. However, there were statistically significant differences (P > 0.01) between G1 and G4, and G1 and G5 in the cleanliness of the middle and apical one‐thirds of the root canals.Conclusions Irrigation with 17% EDTA, 6% phosphoric acid and 6% citric acid did not remove all the smear layer from the root‐canal system. In addition, these acidic solutions demineralized the interbular dentine around tabular openings, which became enlarged. The CO2 laser was useful in removing and melting the smear layer on the instrumented root‐canal walls and the Er:YAG laser was the most effective in removing the smear layer from the root‐canal wall.
Laser light transmission in teeth: a study of the patterns in different species
Authors: Odor T. M. , Chandler N. P. , Watson T. F. , Ford T. R. Pitt , McDonald F. 
Published: March 2003

Aim The aim of this study was to investigate the pattern of light transmission through teeth of different species and to examine laser light propagation within enamel from various animal sources.Methodology Sectioned teeth from five species – pig, horse, sheep, cat and rat – were evaluated. Samples were illuminated individually by a helium–neon laser light from the buccal surface using a probe 0.5 mm in diameter placed at varying angles between 60 and 1208C. The pattern of light transmission was observed macroscopically. Further evaluation of laserlight transmission in enamel was achieved using confocal microscopy.Results In each species, light was transmitted through the tooth to the pulp, but in the cat and the rat, light was also transmitted to the far side of the tooth. Despite the different patterns of enamel in the species, light was transmitted through enamel to dentine.Conclusion Light from a laser Doppler probe appeared to reach the dental pulp in all the species; however, in the mammals with smaller teeth, light may also have been able to reach the periodontium and thus the reflected signal may not be entirely of pulpal origin.
The removal of the smear layer using the Quantec system. A study using the scanning electron microscope
Authors: Bertrand M. ‐F. , Pizzardini P. , Muller M. , Médioni E. , Rocca J. ‐P. 
Published: March 2003

Aim The aim of this study was to determine the ability of the Quantec Series 2000 rotary nickel–titanium endodontic system to remove dentinal debris and smear layer produced during canal preparation.Methodology A first group (control) of 12 curved root canals was prepared using conventional manual instruments and the step‐back technique. A second group of 12 curved root canals was instrumented using the complete Quantec sequence according to the manufacturer’s instructions. In both groups, irrigation was performed using a 3% NaOCl solution. The canal walls were observed under a scanning electron microscope and the coronal, middle and apical thirds of each canal photographed at a magnification of 500.The views were divided into 10 subareas by overlaying a grid, and the absence or presence of a smear layer was rated and scored on three appearances using the scale described by
Ciucchi et al. (1989) .Results The scores were higher (i.e. less debris was present) in the middle third (P 0.0001) and in the apical third (P 0.0001) of canals prepared with the Quantec system when compared with those prepared with K‐files. Nevertheless, in canals prepared with Quantec instruments, the scores were significantly higher in the coronal third compared with the apical third (P 0.005).Conclusions The Quantec rotary system produced cleaner canal walls than conventional manual instrumentation, particularly in the middle and apical thirds. This finding may imply that stresses applied to the cutting regions of Quantec instruments by accumulation and compression of the smear layer are minimized.
In vitro susceptibility of Candida albicans to four disinfectants and their combinations
Authors: Waltimo T. M. T. , Ørstavik D. , Sirén E. K. , Haapasalo M. P. P. 
Published: March 2003

Waltimo TMT, Ørstavik D, Sirén EK, Haapasalo MPP. In vitro susceptibility of Candida albicans to four disinfectants and their combinations. International Endodontic Journal, 32, 421–429 1999.Aim The aim of this study was to evaluate the susceptibility of seven strains of Candida albicans to four disinfectants: iodine potassium iodidea, chlorhexidine acetate, sodium hypochlorite and calcium hydroxide. In addition, all possible pairs of the disinfectants were tested in order to compare the effect of the combination and its components.Methodology Filter paper discs were immersed in standardized yeast suspensions and then transferred to disinfectant solutions of different concentrations and incubated at 378C for 30 s, 5 min, 1 h and 24 h. After incubation the filter paper discs were transferred to vials with PBS and glass beads that were then vigorously shaken for dispersal of the yeast cells. PBS with resuspended yeasts was serially diluted 10‐fold. Droplets of 25 μL from each dilution were inoculated on TSB agar plates and incubated in air at 378C for 24 h. The number of colony‐forming units was then calculated from appropriate dilutions.Results  C. albicans cells were highly resistant to calcium hydroxide. Sodium hypochlorite (5% and 0.5%) and iodine (2%) potassium iodide (4%) killed all yeast cells within 30 s, whilst chlorhexidine acetate (0.5%) showed complete killing after 5 min. Combinations of disinfectants were equally or less effective than the more effective component. All C. albicans strains tested showed similar susceptibility to the medicaments tested.Conclusions This study indicates that sodium hypochlorite, iodine potassium iodide and chlorhexidine acetate are more effective than calcium hydroxide against C. albicans in vitro. However, combining calcium hydroxide with sodium hypochlorite or chlorhexidine may provide a wide‐spectrum antimicrobial preparation with a long‐lasting effect.
A comparison in vitro of fibroblast attachment to resected root‐ends
Authors: Weston G. D. , Moule A. J. , Bartold P. M. 
Published: March 2003

Weston GD, Moule AJ, Bartold PM. A comparison in vitro of fibroblast attachment to resected root‐ends. International Endodontics Journal, 32, 444–449 1999.Aim The aim of this study was to investigate the effect of surface morphology of root ends resected with various bur configurations on fibroblast attachment.Methodology Seventy‐two human single‐rooted teeth were collected and decoronated. The root canals were instrumented, and then obturated with thermoplasticized gutta‐percha using AH‐26 as the sealer. The roots were randomly divided into eight different groups, and apical root‐end resections were performed using eight different instruments, which included high and low speed burs and a scalpel blade. After each root was resected, the surface area of the root end was measured. Cultured human periodontal ligament fibroblasts were radiolabelled and then allowed to attach, in vitro, to the root‐ends. Cell attachment to the resected root‐ends was determined by counting in a liquid scintillation system and expressed as the number of decays per min/mm2 (DPM/mm2) of root surface.Results There was no significant difference in fibroblast attachment to the root‐ends prepared with various instruments.Conclusions These findings indicate that the choice of instrument for root‐end resection has little influence on the initial attachment of fibroblasts, and thus may have little effect on healing following root‐end resection.