bluuebunny/crossref_metadata_2025_split huggingface dataset:
Redistribution of the sheep neonatal Fc receptor in the mammary gland around the time of parturition in ewes and its localization in the small intestine of neonatal lambs
Authors: Mayer Balázs , Zolnai Anna , Frenyó László V. , Jancsik Veronika , Szentirmay Zoltán , Hammarström Lennart , Kacskovics Imre 
Published: March 2003

SummaryMaternal immunity is mediated exclusively by colostral immunoglobulins in ruminants. As the neonatal Fc receptor (FcRn) is suggested to be involved in the transport of immunoglobulin G (IgG) in the mammary gland, we cloned this receptor from sheep and analysed its expression in the mammary gland around the time of parturition and also in the small intestine from the newborn lamb. FcRn heavy‐chain mRNA was detected (by using in situ hybridization) exclusively in the acinar and ductal epithelial cells in mammary gland biopsies both before and after parturition. Immunohistochemistry revealed that the cytoplasm of the epithelial cells of the acini and ducts in the mammary gland biopsies stained homogeneously before parturition. A remarkable difference was observed in the pattern after lambing, where the apical side of the cells was strongly stained. The presence of the FcRn in the acinar and ductal epithelial cells of the mammary gland, and the obvious change in distribution before and after parturition, indicate that the FcRn plays an important role in the transport of IgG during colostrum formation in ruminants. Immunohistochemical analysis detected a strong apical and a weak basal FcRn signal in the duodenal crypt cells of a neonatal lamb, which have been previously demonstrated to secrete IgG1 in newborn ruminants. The FcRn was not detected in the duodenal enterocytes, which absorb intact IgG from the colostrum in a non‐specific manner. These data suggest that FcRn is involved in IgG1 secretion in ruminant epithelial cells.
Insulin‐like growth factor‐1 activates Akt and Jun N‐terminal kinases (JNKs) in promoting the survival of T lymphocytes
Authors: Walsh Patrick T. , Smith Loraine M. , O'Connor Rosemary 
Published: March 2003

SummaryInsulin‐like growth factor 1 receptor (IGF‐1R) expression is augmented on T cells upon ligation of CD28, and this promotes IGF‐1‐mediated protection from Fas‐induced cell death for up to 6 days. To determine the mechanism of action of IGF‐1R in T‐cell expansion, we investigated the signalling pathways activated by IGF‐1 in T cells and in Jurkat cells. We found that IGF‐1 transiently induces Akt, jun N‐terminal kinases (JNK), and c‐Jun phosphorylation in activated T cells, with JNK and c‐Jun phosphorylation occurring faster than Akt phosphorylation. To mimic IGF‐1R expression levels in CD28‐stimulated Jurkat cells these cells were stably transfected to over‐express the IGF‐1R. Jurkat/IGF‐1R cells exhibited enhanced constitutive Akt phosphorylation compared with mock‐transfected controls, but IGF‐1 induced transient phosphorylation of MKK4, JNKs, and c‐Jun. Inhibition of PI‐3 kinase activity and Akt phosphorylation with LY294002 totally suppressed IGF‐1‐mediated protection from Fas killing in activated T cells, but only partially suppressed IGF‐1‐mediated protection in Jurkat/IGF‐1R cells. However, either dicumarol in T cells or a dominant negative JNK1 (APF) in Jurkat/IGF‐1R cells greatly suppressed IGF‐1‐mediated protection from Fas killing. Together, these data demonstrate that IGF‐1‐mediated activation of JNKs and PI‐3 kinase contributes to normal T‐cell survival, whereas the JNK pathway may be more important in Jurkat leukaemia cells.
Behavioural effects of attitudes toward constraint in CASE: the impact of development task and project phase
Authors: Day Donald L. 
Published: March 2003

AbstractThis paper examines the effects of systems development task and phase upon individuals’ attitudes and behaviour while using computer‐aided systems engineering (CASE) tools. A previous empirical study of developers in several countries is revisited. Findings indicate that the mediating effects of task and phase upon the relationship among constraints, attitudes and behaviour are weak. They thereby support earlier research, which claims significance between attitudes and behaviour, by eliminating the potentially mediating effects of task and phase. Findings also indicate that CASE tool users associate implementation, integration and maintenance in terms of tasks and constraints, suggesting a reassessment of traditional life cycle models.
Characterization of the soluble guanylyl cyclase β‐subunit gene in the mosquito Anopheles gambiae
Authors: Caccone A. , Garcia B. A. , Mathiopoulos K. D. , Min G.‐S. , Moriyama E. N. , Powell J. R. 
Published: March 2003

AbstractGenomic DNA corresponding ot the soluble guanylyl cyclase β‐subunit (GCSβ) gene was cloned and sequenced form Anopheles gambiae. The sequence was 8103 bp long and presumably included the entire coding region. The deduced amino acid sequence was 71% and 62% similar to previously known Drosophila and vertebrate GCSβ, while the C‐terminus of A. gambiae GCSβ was shorter. Because of the conserved characteristics in each functional domain, the high G+C % in the third codon positions compared to the introns, the lack of internal stop codons, and the fact that we identified the gene from a cDNA, we conclude that this A. gambiae gene is functional. This is the first detailed description of a guanylyl cyclase gene structure (e.g. intron–exon boundaries). Interstingly, within the fifth intron we found high similarity to the flanking regions of the Pegasus‐27 transposable element and other noncoding regions of the A. gambiae genome.
Mariner (Mos1) transposase and genomic integration of foreign gene sequences in Bombyx mori cells
Authors: Wang W. , Swevers L. , Iatrou K. 
Published: March 2003

AbstractWidespread occurrence in insects and the capacity to transpose in the absence of host‐derived factors means that mariner‐like elements are considered to be attractive candidates for the development of a universal insect genetic transformation system. Here we show that the Mos1 mariner element of Drosophila mauritiana is capable of mediating excision and transposition events in a silkmoth (Bombyx mori) derived tissue culture cell line (Bm5 cells). Plasmid rescue assays, in combination with Southern hybridization and polymerase chain reaction (PCR) analyses, confirm that the Mos1 transposase can mediate excision of DNA sequences, inserted between terminally repeated sequences recognized by the transposase, and integration into the chromosomal DNA of the Bm5 cells. In addition to chromosomal integration events, inter‐ and intraplasmid transposition and target element excision events were also detected. Approximately 50% of the plasmids recovered from plasmid rescue assays were found to contain the ‘signature’ of Mos1‐specific excision and/or integration events, indicating that the mariner transposase functions efficiently in the Bombyx cells. Because mariner‐induced excision and integration events are strictly dependent on the presence of a co‐transfected Mos1 transposase expression vector, it is clear that the multiple copies of endogenous mariner‐like elements (Bmmar1) that exist in the Bombyx genome are neither functional nor do they interfere with the efficiency of the transposition process. Thus, the Mos1 element and, probably, mariner elements, in general, hold great promise for the development of genetic transformation systems for lepidopteran insects.
Evidence for extensive genetic differentiation among populations of the malaria vector Anopheles arabiensis in Eastern Africa
Authors: Donnelly M. J. , Townson H. 
Published: March 2003

AbstractWe describe the geographical population structure of the malaria vector Anopheles arabiensis in Eastern Africa. Allelic variation at eight microsatellite loci was scored in samples from nine localities along a 4500 km transect from Sudan to Mozambique. Highly significant differences in genotype frequencies were found between all populations separated by more than 200 km. Populations within Malawi separated by 191 km were indistinguishable, as were those within Sudan separated by 134 km. FST and ρST gave significant estimates of isolation by distance. These data, lead us to conclude that there are extensive barriers to gene flow in this region. The high estimates of Nm (9.4 from FST and 5.2 from ρST) indicate recent range expansion in this species rather than extensive contemporary gene flow.
Genetic transformation of the housefly Musca domestica with the lepidopteran derived transposon piggyBac
Authors: Hediger M. , Niessen M. , Wimmer E. A. , Dübendorfer A. , Bopp D. 
Published: March 2003

AbstractThe piggyBac transposable element was successfully used for stable genetic transformation of the housefly Musca domestica. The construct contains the EGFP marker under the control of Pax‐6 binding sites, which can drive eye‐specific expression in insect species as distantly related as Drosophila melanogaster and Tribolium castaneum[Berghammer, A.J., Klingler, M. and Wimmer, E.A. (1999)Nature 402: 370–371]. We obtained seven independent integration events among 41 fertile G0Musca flies. Most of the transformed lines contained two or more chromosomal insertions of the EGFP marker which were stably inherited over more than 15 generations. piggyBac‐mediated transposition was verified by identifying the characteristic TTAA duplication at the insertion sites. This first report of stable transmission of a genetic marker in Musca confirms the use of this vector‐marker system for effective gene transfer in a broad range of insect species.
The juvenile hormone binding protein of silkworm haemolymph: gene and functional analysis
Authors: Vermunt A. M. W. , Kamimura M. , Hirai M. , Kiuchi M. , Shiotsuki T. 
Published: March 2003

AbstractA cDNA fragment of haemolymph juvenile hormone binding protein (hJHBP) from larvae of Bombyx mori was amplified by RT‐PCR using degenerate primers based on the N‐terminal amino acid sequence of purified hJHBP and a conserved region near the C‐terminus of other lepidopteran hJHBPs. 5′‐ and 3′‐ends were amplified by RACE to yield cDNAs, hJHBP1 and hJHBP2, encoding 225 amino acids with three substitutions. hJHBP‐mRNA levels in the fat body were constant in the 4th instar, but decreased in the 5th. JHBP protein was constant until wandering, then declined. Recombinant hJHBP1 expressed in E. coli migrated on SDS‐PAGE with a Mr of 32 kDa and showed a Kd of 4.5 × 10−7 M with JH III, both similar to those of native hJHBP.
Louse (Insecta: Phthiraptera) mitochondrial 12S rRNA secondary structure is highly variable
Authors: Page R. D. M. , Cruickshank R. , Johnson K. P. 
Published: March 2003

AbstractLice are ectoparasitic insects hosted by birds and mammals. Mitochondrial 12S rRNA sequences obtained from lice show considerable length variation and are very difficult to align. We show that the louse 12S rRNA domain III secondary structure displays considerable variation compared to other insects, in both the shape and number of stems and loops. Phylogenetic trees constructed from tree edit distances between louse 12S rRNA structures do not closely resemble trees constructed from sequence data, suggesting that at least some of this structural variation has arisen independently in different louse lineages. Taken together with previous work on mitochondrial gene order and elevated rates of substitution in louse mitochondrial sequences, the structural variation in louse 12S rRNA confirms the highly distinctive nature of molecular evolution in these insects.
Arrangement and structural conservation of the mitochondrial control region of two species of Plecoptera: utility of tandem repeat‐containing regions in studies of population genetics and evolutionary history
Authors: Schultheis A. S. , Weigt L. A. , Hendricks A. C. 
Published: March 2003

AbstractLow levels of primary sequence similarity across insect taxa have led to the suggestion of conserved structural elements in the insect mitochondrial control region. Our aim was to determine whether previously described motifs and secondary structures exist in stoneflies (Plecoptera). Several motifs and structural elements previously described in Orthoptera and Diptera were found, including a conserved ‘hairpin’ structure that may play a role in the initiation of mtDNA replication. The repeat region had the highest percentage similarity, lowest A‐T content and highest transition to transversion ratio, suggesting a unique evolutionary pattern for the repeats. Finally, we discuss the usefulness of the control region in population genetic and evolutionary studies.
Antimicrobial effects of various endodontic irrigants on selected microorganisms
Authors: Ayhan H. , Sultan N. , Çirak M. , Ruhi M. Z. , Bodur H. 
Published: March 2003

Aim This study was undertaken to determine the antimicrobial effect of various endodontic irrigants against six selected microorganismsMethodology Staphylococcus aureus, Enterococcus faecalis, Streptococcus salivarius, Str. pyogenes, Escherichia coli and Candida albicans were included in the study. Pre‐sterilized Whatman paper discs, 6 mm in diameter and soaked with the test solution, were prepared and placed onto the previously seeded agar Petri plates. Each plate was incubated aerobically. A zone of inhibition was recorded for each plate and the results were analysed statistically.Results 5.25% NaOCl was effective against all test microorganisms with a substantial zone of inhibition. Saline was always ineffective. Decreased concentration of NaOCl significantly reduced its antimicrobial effect. Cresophene showed a significantly larger (P > 0.05) average zone of inhibition compared to the other experimental irrigants. Alcohol had smaller but not significantly different zones of inhibition than chlorhexidine.Conclusions 5.25% NaOCl was superior in its antimicrobial abilities compared with other irrigants used. A reduced concentration of NaOCl (0.5%) resulted in significantly decreased antimicrobial effects. When compared with 21% alcohol, 0.5% NaOCl and 2% chlorhexidine, paramonochlorophenol (cresophene) showed a greater antimicrobial effect.
Micro‐computed tomography: a new tool for experimental endodontology
Authors: Rhodes J. S. , Ford T. R. Pitt , Lynch J. A. , Liepins P. J. , Curtis R. V. 
Published: March 2003

Aim Micro‐computed tomography (MCT) using cone‐beam geometry is a method of producing true 3D images of the structure of small samples. A prototype MCT unit was adapted for imaging teeth to examine whether it could be used to quantify the instrumentation of root canals.Methodology Ten mandibular first molar teeth that had intact crowns and fully formed roots were scanned using MCT at a resolution of 0.081mm and 3D‐rendered images created; root canals were segmented from this. Reproducibility of MCT was verified for root canal shape and size. Access cavities were prepared into the pulp space and root canals enlarged to a continuously tapering preparation using a crowndown technique. Each tooth was scanned again to allow comparison of pre‐ and post‐instrumentation images. The roots were then sectioned at five predeterminedhorizontal levels for video‐digitized measurement of dimensions of roots and root canals. The video images had a resolution of 0.025mm. Video‐digitized images of the physical cut surfaces were compared with equivalent MCT reconstructed images. The total area of the root canals (internal) and root (external) at each level were calculated from both MCT reconstructions and video‐digitized images, and compared.Results There was a highly significant correlation between MCT and video images for both external and internal areas (r = 0.94). Rendered 3D images were constructed to show the root canal systems of teeth. The total volumes of the apical 7.5mm of root canals were calculated from rendered images of nine teeth before and after instrumentation. The mean amount of dentine removed by instrumentation was 3.725mm3, which was 28% of the original canal volume.Conclusions Micro‐computed tomography was shown to be accurate for experimental endodontology.
Cleaning efficacy of two apical preparation regimens following shaping with hand files of greater taper
Authors: Lumley P. J. 
Published: March 2003

AbstractAimThe aim of this investigation was to assess canal cleaning following shaping with hand files of greater taper.MethodologyThirty mesial canals and 30 distal canals in mandibular molars were prepared with .08 and .10 hand files of greater taper, respectively. Following initial preparation, 0.02 instruments were used incrementally shorter in a stepback manner. In half the canals instrumentation was performed to size 35 1 mm short of the canal terminus. In the other half the series was continued through to size 60 using stepback increments of half to one millimetre as appropriate (foramen size was maintained at size 20 in all groups). Sodium hypochlorite (4.5%) and REDTA (17%) were used as irrigants for all groups. Cleaning efficacy was evaluated by scoring the amount of remaining debris using a light microscope (×50) and calibrated eyepiece micrometer (range 0–3).ResultsCanals stepped back through to a size 60 were significantly cleaner than those instrumented to a size 35 only (Mann–Whitney P < 0.05).ConclusionRefining the apical region of canal preparation by stepping back through to a size 60 reduced remaining debris following shaping with files of greater taper.
Cleaning effectiveness of root canal irrigation with electrochemically activated anolyte and catholyte solutions: a pilot study
Authors: Solovyeva A. M. , Dummer P. M. H. 
Published: March 2003

AbstractAimThe aim of this study was to evaluate the potential of electrochemically activated (ECA) anolyte and catholyte solutions to clean root canals during conventional root canal preparation.MethodologyTwenty extracted single‐rooted human mature permanent teeth were allocated randomly into four groups of five teeth. The pulp chambers were accessed and the canals prepared by hand with conventional stainless steel endodontic instruments using a double‐flared technique. One or other of the following irrigants was used during preparation: distilled water, 3% NaOCl, anolyte neutral cathodic (ANC) (300 mg L−1 of active chlorine), and a combination of anolyte neutral cathodic (ANC) (300 mg L−1 of active chlorine) and catholyte. The teeth were split longitudinally and the canal walls examined for debris and smear layer by scanning electron microscopy. SEM photomicrographs were taken separately in the coronal, middle and apical parts of canal at magnification of ×800 to evaluate the debridement of extra‐cellular matrix and at a magnification of ×2500 to evaluate the presence of smear layer.ResultsIrrigation with distilled water did not remove debris in the apical part of canals and left a continuous and firm smear layer overlying compressed low‐mineralized predentine. All chemically active irrigants demonstrated improved cleaning potential compared to distilled water. The quality of loose debris elimination was similar for NaOCl and the anolyte ANC solution. The combination of anolyte ANC and catholyte resulted in improved cleaning, particularly in the apical third of canals. The evaluation of smear layer demonstrated that none of the irrigants were effective in its total removal; however, chemically active irrigants affected its surface and thickness. Compared to NaOCl, the ECA solutions left a thinner smear layer with a smoother and more even surface. NaOCl enhanced the opening of tubules predominantly in the coronal and middle thirds of canals, whereas combination of ANC and catholyte resulted in more numerous open dentine tubules throughout the whole length of canals.ConclusionsIrrigation with electrochemically activated solutions cleaned root canal walls and may be an alternative to NaOCl in conventional root canal treatment. Further investigation of ECA solutions for root canal irrigation is warranted.
Some factors affecting the concentration of available chlorine in commercial sources of sodium hypochlorite
Authors: Frais S. , Ng Y‐L. , Gulabivala K. 
Published: March 2003

AbstractAims To evaluate the availability, effect of storage, dilution and heating on some commercial sources of sodium hypochlorite (NaOCl).Methodology All pharmacies in a Regional Health Authority were telephone surveyed to establish the proprietary and nonproprietary NaOCl products available, their cost and concentration. Ninety‐six freshly produced bottles of a commercially available thin household bleach (J. Sainsbury’s) were randomly stored in four different modes (full 1 L bottles in dark at room temperature, half‐empty 1 L bottles under the same conditions, full 200 mL bottles under the same conditions, full 200 mL bottles stored at 37 °C) up to 6 months. The available chlorine in the bleach solutions was evaluated at specific time intervals (0, 1, 2 weeks, 1, 2, 3, 4, 6 months) using iodometric titration. Four brands of commercially available bleaches (J. Sainsbury’s Thin Household Bleach, Tesco’s Value Bleach, Tesco’s Red Label Bleach, Safeway’s Savers Bleach) were diluted (by 1 : 1, 1 : 2 or 1 : 3 dilution factors) and samples taken from each dilution for titration to test predictability. NaOCl solutions (5% w/w) were heated in covered or uncovered beakers up to 60–85 °C. Samples were taken from each beaker at time 0 and each h up to 4 h, for titration.Results Of the 116 pharmacies, 33% could supply a proprietary product and 53% a nonproprietary product. In all, 78% were able to supply a NaOCl product. There was no significant difference (P < 0.05) in available chlorine at baseline between the different modes of storage. After storage at room temperature for 6 months, there were no significant differences (3% of original; P > 0.05) between the different modes of storage. When the storage temperature was 37 °C, however, there was a significant difference (38% of original; P < 0.01) at 6 months. Comparison of baseline with the concentrations of available chlorine at 6 months showed significant differences (P < 0.01) for all conditions. The available chlorine concentration in four brands of ‘thin’ supermarket bleaches could be predictably reduced according to the dilution factor. When 5% NaOCl was heated to 60–85 °C for up to 4 h, the available chlorine was increased to 6% in covered solutions and 9% in uncovered solutions.Conclusions Both proprietary and nonproprietary solutions of NaOCl should be relatively easily obtainable in the UK. Stored under appropriate conditions, commercially available thin bleaches and nonproprietary solutions of NaOCl may be diluted to obtain predictable concentrations. Heating solutions of NaOCl may cause unpredictable changes to the concentration, depending upon conditions.
Polymerase chain reaction detection of Treponema denticola in endodontic infections within root canals
Authors: Siqueira J. F. , Rôças I. N. , Favieri A. , Oliveira J. C. M. , Santos K. R. N. 
Published: March 2003

AbstractAimA 16S rDNA‐based polymerase chain reaction (PCR) method was used to detect the occurrence of Treponema denticola in root canals.MethodologySamples were collected from 54 single‐rooted teeth having carious lesions and necrotic pulps. DNA extracted from the samples was amplified using the PCR assay, which yielded a specific fragment of T. denticola 16S rDNA.Results T. denticola was detected in 10 of 29 asymptomatic cases (34.5%), eight of 15 root canals that were tender to percussion (53.3%), and five of 10 teeth with acute periradicular abscess (50%). In general, T. denticola was found in 23 of 54 cases (42.6%).ConclusionsFindings suggest that T. denticola can be involved in the pathogenesis of periradicular lesions of endodontic origin.