bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fibroblasts inhibit the production of interleukin‐12p70 by murine dendritic cells
Authors: Berthier Rolande , Rizzitelli Alexandra , Martinon‐Ego Catherine , Laharie Anne‐Marie , Collin Véronique , Chesne Serge , Marche Patrice Noël 
Published: March 2003

SummaryInterleukin‐12 p70 (IL‐12p70) is a key cytokine produced by dendritic cells (DC) able to drive the development of T helper type 1 (Th1) lymphocytes. We showed that thymic and other fibroblasts strongly inhibit IL‐12p70 production by splenic DC stimulated by lipopolysaccharide plus either anti‐CD40 or interferon‐γ (IFN‐γ) and by purified splenic DC stimulated by Pansorbin plus IFN‐γ. This IL‐12p70 inhibitory activity is secreted in the conditioned medium of primary fibroblasts and fibroblast cell lines but not by haematopoietic cell lines. As IL‐10 was the unique factor able to inhibit IL‐12p70 produced by cultured splenic DC, we showed that a neutralizing antibody to IL‐10 did not suppress the IL‐12p70 inhibitory activity of thymic fibroblast‐conditioned medium (FCM). This FCM potently inhibits the maturation and expression of major histocompatibility complex class II and co‐stimulatory molecules induced by stimulation of spleen‐derived DC. While thymic FCM suppressed the IL‐12p70 expression by stimulated spleen‐derived DC, tumour necrosis factor‐α production is not affected. This inhibitory activity is able to down‐regulate the IL‐12p35 subunit transcription and expression, resulting in the impaired assembly of IL‐12p70 heterodimer. As fibroblasts are present in the tissue microenvironment and are active players in the establishment of an immune response, the nature and role of the fibroblastic inhibitory activity remain to be established.
Ethanol promotes T cell apoptosis through the mitochondrial pathway
Authors: Kapasi Aditi A. , Patel Geeta , Goenka Anuj , Nahar Nilay , Modi Neeraj , Bhaskaran Madhu , Reddy Krishna , Franki Nicholas , Patel Jaimita , Singhal Pravin C. 
Published: March 2003

SummaryClinical reports suggest that acute ethanol intoxication is often associated with lymphopenia. Previously, ethanol was reported to invoke thymocyte apoptosis. We studied the effect of ethanol on T cell apoptosis. In addition, we evaluated the molecular mechanism of ethanol‐induced T cell apoptosis. Human T cells harvested from healthy subjects after an alcohol drinking binge showed enhanced T cell apoptosis (before, 0·4 ± 0·2% versus after, 19·6 ± 2·5% apoptotic lymphocytes/field; P < 0·001). In in vitro studies, ethanol in a concentration of 50 mm and higher enhanced the apoptosis of Jurkat cells. DNA isolated from ethanol‐treated Jurkat cells displayed integer multiples of 180 base pairs. Ethanol decreased Jurkat cell expression of Bcl‐2, whereas ethanol increased Jurkat cell expression of Bax. Jurkat cells treated with ethanol also showed translocation of cytochrome C into cytosol. Moreover, a caspase‐9 inhibitor partially inhibited ethanol‐induced Jurkat cell apoptosis. In in vivo studies, after binge drinking, T cell expression of Bcl‐2 also decreased. In addition, binge drinking induced the cleavage of caspase‐3, suggesting activation of caspase‐3 in T cells. These results suggest that ethanol promotes T cell apoptosis through the activation of intrinsic or mitochondrial pathway.
Intragenomic heterogeneity of a ribosomal DNA spacer (ITS2) varies regionally in the neotropical malaria vector Anopheles nuneztovari (Diptera: Culicidae)
Authors: Onyabe D. Y. , Conn J. E. 
Published: March 2003

AbstractWe investigated intragenomic heterogeneity of ITS2 within twenty individual Anopheles nuneztovari (subgenus Nyssorhynchus) from five geographical localities in the neotropics (three from Brazil and one each from Colombia and Venezuela) by cloning and sequencing PCR‐amplified copies of this spacer. Intragenomic heterogeneity was observed in thirteen of twenty mosquitoes of both sexes from all localities. As estimated by uncorrected P, however, mean sequence divergence was greater in mosquitoes from Brazil (PR = 0.0100, BL = 0.0196, AB = 0.0182) than in those from Venezuela (SO = 0.0026) or Colombia (SI = 0.0078). Sequence divergence per genome was significantly higher in mosquitoes from Brazil than in those from SO and SI. In fact, divergence among ITS2 variants within single mosquitoes from the Brazilian localities was often as great as that between localities. Similarly, the number of variants per mosquito was significantly greater in Brazil (maximum of six variants) than in both SO and SI (maximum of two variants). These results indicate that homogenization of ITS2 has proceeded to a greater extent in SO and SI than in the localities in Brazil. The differences in intragenomic heterogeneity between both SO and SI versus the Brazilian localities probably reflect either differences in population‐level processes such as gene flow and genetic drift, or the fact that these localities may represent two or more cryptic species, as suggested by other studies.
Conserved features at the 5′ end of Drosophila R2 retrotransposable elements: implications for transcription and translation
Authors: George J. A. , Eickbush T. H. 
Published: March 2003

Abstract R2 non‐LTR retrotransposable elements insert site‐specifically into the 28S ribosomal genes of insects. The sequence of the 5′ end of full‐length R2 elements from thirteen species of Drosophila were compared. Sequences within the 5′ untranslated region (5′ UTR) revealed little to suggest the presence of a promoter. Protein translation initiates within the 5′ UTR and requires the bypassing of a highly conserved termination codon preceding the single R2 open reading frame. This bypassing probably involves a conserved RNA secondary structure which brings a potential initiation codon into close proximity to this termination codon. The most highly conserved sequence within the 5′ UTR has properties similar to internal ribosomal entry sites. Based on these findings, we propose that R2 elements are co‐transcribed with the 28S gene and are translated as part of a large ribosomal subunit.
Four serine proteinases expressed in Manduca sexta haemocytes
Authors: Jiang H. , Wang Y. , Kanost M. R. 
Published: March 2003

AbstractSeveral putative serine proteinases were detected in Manduca sexta larval plasma by labelling with radio‐active diisopropyl fluorophosphate. To begin to identify and characterize such enzymes, a polymerase chain reaction was carried out using haemocyte cDNA as template and primers designed to amplify conserved sequences from serine proteinases. Four serine proteinase cDNA fragments were cloned. These were used as probes to screen an M. sexta larval haemocyte cDNA library to obtain full‐length clones encoding haemocyte proteinases 1–4 (HP1, HP2, HP3 and HP4). HP1 and HP2 contain an aminoterminal ‘clip’ domain similar to those found in horse‐shoe crab clotting enzyme and clotting factor B and also in the Drosophila melanogaster proteinases snake and easter. HP3 and HP4 are most similar to proteinases from mammalian leucocytes. HP1 and HP2 are both present in plasma. HP1 is expressed in haemocytes (granular cells and oenocytoids) and not in fat body. HP2 is expressed in fat body and in granular haemocytes, plasmatocytes and oenocytoids. After injection of larvae with bacteria, the level of HP2 mRNA decreased in haemocytes and increased in fat body.
Molecular cloning and expression of two hexamerin cDNAs from the mosquito, Aedes aegypti
Authors: Crampton J. M. , James A. A. , Gordadze A. V. , Korochkina S. E. , Zakharkin S. O. , Norton A. L. , Beneš H. 
Published: March 2003

AbstractFourth‐instar larvae of Aedes aegypti synthesize two types of hexamerins, Hexamerin‐1 (AaHex‐1) and Hexamerin‐2 (AaHex‐2), whose subunits are distinguished by different methionine and aromatic amino acid contents. In early female pupae only the methionine‐rich AaHex‐1γ subunit accumulates to two‐fold higher levels than in males. To investigate the relationship between hexamerin structure and the roles of Hex‐1 and Hex‐2 during mosquito development and reproduction, we have cloned and sequenced cDNAs encoding the AaHex‐2α, ‐2β and AaHex‐1γ subunits. Comparison with other insect hexamerins revealed that the Aedes Hex‐1 and Hex‐2 proteins belong, respectively, to the two hexamerin subfamilies previously defined for brachyceran Diptera. Probes specific for the Hex‐2α and Hex‐1γ transcripts showed that expression of both genes follows the same developmental timetable. However, greater Hex‐1γ mRNA accumulation may contribute to the higher levels of Hex‐1γ protein in early female pupae.
A locust type 1 ADP‐ribosylation factor (lARF1)* is 100% identical in amino acid sequence to Drosophila ARF1 despite obvious DNA sequence divergence
Authors: Hannan F. , Evans P. D. 
Published: March 2003

AbstractThe cDNA of a type 1 ADP‐ribosylation factor (ARF) from the desert locust, Locusta migratoria was cloned, sequenced and compared to ARF1 genes of other species. The locust ARF1 protein is 100% identical with the ARF1 protein of the fruit fly Drosophila melanogaster even though the DNA sequences are only 79% identical. The significance of this finding in relation to the considerable evolutionary distance between hemimetabolous and holometabolous insects is discussed.
Wolbachia in the Asian rice gall midge, Orseolia oryzae (Wood‐Mason): correlation between host mitotypes and infection status
Authors: Behura S. K. , Sahu S. C. , Mohan M. , Nair S. 
Published: March 2003

AbstractUsing a PCR‐based method, we detected Wolbachia in the Asian rice gall midge. Furthermore, results showed that all females across all biotypes are infected with Wolbachia. However, all male flies are not infected and show different infection frequency in different biotypes. We have also identified three mitotypes, in the rice gall midge, based on DraI restriction pattern of a portion of the 12S rRNA gene that was PCR amplified using primers specific to this gene. All the females and infected male flies had type 1 mtDNA while uninfected males showed only type 2 or 3 mtDNA. Inheritance patterns of mtDNA revealed the existence of a correlation between mtDNA type and Wolbachia infection in the Asian rice gall midge. Evidence for paternal inheritance of mtDNA in Wolbachia‐free gall midge is also presented.
Effect of baculovirus infection on the mRNA and protein levels of the Spodoptera frugiperda eukaryotic initiation factor 4E
Authors: van Oers M. M. , van der Veken L. T. J. N. , Vlak J. M. , Thomas A. A. M. 
Published: March 2003

AbstractThe cDNA sequence of eukaryotic translation initiation factor eIF4E was derived from a Spodoptera frugiperda cDNA library. Eight tryptophan residues, typical for eIF4E, are strictly conserved in the encoded 210 amino acid protein. A polyclonal antiserum detected a 26 kDa protein in lepidopteran cell lines, but not in dipteran cells. Sf21 cells have a single eIF4E gene copy, which is transcribed into a 1500 nt transcript. Infection with AcMNPV resulted in a decrease in eIF4E mRNA starting between 12 and 24 h postinfection (p.i.), while reduced eIF4E protein levels were observed at 48 h p.i. Two forms of eIF4E were recognized that differed in their iso‐electric point, of which the relative abundance did not change during infection. Mutagenesis experiments using recombinant baculoviruses revealed that the variation in mobility between these two forms did not result from a difference in the phosphorylation state of Ser‐202, the serine residue that corresponds with the eIF4E phosphorylation site in mammalian eIF4E.
Extrachromosomal RNA–DNA complex containing long telomeric repeats in chironomids
Authors: Rosén M. , Kamnert I. , Edström J.‐E. 
Published: March 2003

AbstractWe have analysed an extracted RNase sensitive fraction containing telomeric repeat sequences in the telomerase negative dipteran Chironomus tentans. It shows a slow and well‐defined electophoretic migration corresponding to > 20 kb and is sensitive not only to RNase, but also to DNase. It hybridizes to both strands of the telomeric repeat with about equal intensities. DNA is probably the dominant component since the fraction is only slightly heavier than genomic DNA in isopycnic gradients but considerably lighter than RNA. It can, nevertheless, be shown to incorporate tritiated uridine. The material might represent another example of extrachromosomal telomeric repeats in telomerase negative cells.
cDNA cloning, characterization and gene expression of nitric oxide synthase from the silkworm, Bombyx mori
Authors: Imamura M. , Yang J. , Yamakawa M. 
Published: March 2003

AbstractMolecular cloning and nucleotide sequencing of cDNA encoding Bombyx mori nitric oxide synthase (BmNOS) was conducted to analyse its possible role in insect immunity. The amino acid sequence deduced from the BmNOS cDNA showed 84%, 54% and 53% identity with those of NOSs from Manduca sexta, Drosophila melanogaster and Rhodonius prolixus. Recombinant BmNOS produced in insect cells using baculovirus was found to require NADPH, Ca2+, calmodulin and tetrahydrobiopterin (BH4) for its activity. The BmNOS gene was constitutively expressed at a low level in the larval fat body, haemocyte, Malpighian tubule and midgut, and adult antenna, and induced strongly in the fat body by lipopolysaccharide (LPS), suggesting that the BmNOS gene plays different physiological roles in different tissues. Injection of NO donors that produce NO in vivo induced the gene expression of an antibacterial peptide, cecropin B, strongly suggesting that NO produced by BmNOS following LPS stimulation is involved in signal transduction as a signalling molecule for immune gene expression.
Nested retrotransposons on the W chromosome of the wild silkworm Bombyx mandarina
Authors: Abe H. , Sugasaki T. , Terada T. , Kanehara M. , Ohbayashi F. , Shimada T. , Kawai S. , Mita K. , Oshiki T. 
Published: March 2003

AbstractThe W chromosome of the silkworms Bombyx mori or B. mandarina is recombinationally isolated from the Z chromosome and the autosomes. We previously characterized a female‐specific randomly amplified polymorphic DNA (RAPD), designated W‐Yamato, derived from the W chromosome of the wild silkworm Bombyx mandarina. To further analyse the W chromosome of B. mandarina, we obtained a lambda phage clone that contains the W‐Yamato RAPD sequence and sequenced the 16.7 kb DNA insert. We found that this DNA comprises a nested structure of at least seven elements: six retrotransposons and one transposable element‐like sequence. The transposable element‐like sequence is inserted into a micropia‐like retrotransposon (Karate). The Karate and the non‐long terminal repeat (non‐LTR) retrotransposon BMC1 are inserted into a 412‐like retrotransposon (Judo). Furthermore, this Judo, and two non‐LTR retrotransposons (Kurosawa and Kendo) are inserted into a Pao‐like retrotransposon (Yamato). These results indicate that the retrotransposons inserted into the W chromosome are not efficiently removed but accumulate gradually as strata without recombination.
The period gene in two species of tephritid fruit fly differentiated by mating behaviour
Authors: An X. , Wilkes K. , Bastian Y. , Morrow J. L. , Frommer M. , Raphael K. A. 
Published: March 2003

AbstractThe period gene is important for the generation and maintenance of biological rhythms. It served as an ideal candidate for the investigation of the mating time isolation between two sibling Queensland fruit fly species, Bactrocera tryoni and Bactrocera neohumeralis. We have isolated the homologues of the period gene in the two species, and show that their putative amino acid sequences are identical. No length polymorphism was detected in the Thr‐Gly repeat region. per mRNA expression, assayed in light–dark diurnal conditions, displayed circadian oscillation in both the head and abdomen of B. tryoni and B. neohumeralis, with the same cycling phase. An alternatively spliced intron was identified in the 3′ untranslated region. The effect of temperature on the splicing and mRNA expression was examined.
Isolation and characterization of a neprilysin‐like protein from Venturia canescens virus‐like particles
Authors: Asgari S. , Reineke A. , Beck M. , Schmidt Otto 
Published: March 2003

AbstractMaternal protein secretions from endoparasitoid wasps are evolutionary adaptations to regulate host physiology as part of an extended wasp phenotype. Virus‐like particles (VLPs) produced in the calyx region of Venturia canescens wasps are involved in immune evasion of the developing parasitoid inside the host. In contrast to polydnaviruses (PDVs), VcVLPs are devoid of any nucleic acids. To understand the role of these particles in the regulation of host physiology and phylogenetic relationship between VLPs and PDVs, it is essential to identify particle proteins. In this paper, we describe the isolation and molecular cloning of a neprilysin‐like gene (VcNEP) coding for a 94 kDa VcVLP protein and discuss its possible role in host regulation.
Developmental profiles and ecdysone regulation of the mRNAs for two ecdysone receptor isoforms in the Mediterranean fruit flyCeratitis capitata
Authors: Verras M. , Gourzi P. , Zacharopoulou A. , Mintzas A. C. 
Published: March 2003

AbstractUsing 5′ RACE with specific primers for the ecdysone receptor B1 isoform of the Mediterranean fruit fly (medfly),Ceratitis capitata, we isolated a cDNA clone encoding the specific region of the medfly ecdysone receptor A isoform (CcEcR‐A). The CcEcR‐A‐specific region was very similar to the EcR‐A‐specific region ofDrosophila melanogasterand less similar to the EcR‐A‐specific regions of Lepidoptera. The developmental expression of both CcEcR‐A and CcEcR‐B1 mRNAs was studied in whole animals, salivary glands and ovaries by RT‐PCR, using isoform‐specific primers. Both CcEcR mRNAs are present in very early embryos, decrease to very low levels during the first hours of embryogenesis and are highly expressed in all consequent embryonic stages. During metamorphosis both isoforms are present showing two peaks; the first at the larval–prepupal transition and the second during the second half of prepupal development. These peaks are correlated with the two puffing cycles and the two major 20‐hydroxyecdysone (20E) increases that occur during medfly metamorphosis. CcEcR‐B1 mRNA was directly induced in larval salivary glandsin vitroby 20E, even at very low concentrations of the hormone, while CcEcR‐A mRNA was slightly induced only by high 20E concentrations and in the absence of a protein synthesis inhibitor. During oogenesis, the CcEcR mRNAs were expressed synchronously, peaking at the beginning of both previtellogenic and vitellogenic phases.
Scanning electron microscope study on the efficacy of root canal wall debridement of hand versus Lightspeed instrumentation
Authors: Bechelli C. , Orlandini S. Zecchi , Colafranceschi M. 
Published: March 2003

Bechelli C, Zecchi Orlandini S, Colafranceschi M. Scanning electron microscope study on the efficacy of root canal wall debridement of hand versus Lightspeed instrumentation. International Endodontic Journal, 32, 484–493 1999.Aim The aim of this in vitro study was to compare the efficacy of root canal wall debridement following hand versus LightSpeedTM instrumentation.Methodology Twenty recently extracted single‐rooted teeth were paired and randomly placed into two treatment groups of 10 teeth each. In group 1, a step‐back instrumentation without initial coronal flaring with stainless steel Hedstroem files was used; group 2 was instrumented with Ni‐Ti LightSpeedTM instru‐ments. Both groups had the same irrigation regimen: 2.5% NaOCl and a 15% EDTA solution. The teeth were then decoronated and each root split longitudinally into two halves to be examined using the scanning electron microscope (SEM). The presence of superficial debris and smear layer was evaluated by a standardized grading system, and the resulting scores submitted to nonparametric statistics.Results Under the conditions of this study, the removal of superficial debris was generally excellent with both canal preparation techniques. Both techniques resulted in variable presence of residual smear layer, with a canal wall covered by smear layer as the predominant characteristic. Generally, the amount of smear layer was greater in the apical than in the middle third of the root, however, this difference was statistically significant (P 0.005) only in hand‐instrumented teeth. The use of LightSpeedTM instruments was associated with significantly more (P 0.05) smear layer presence in the middle region of the root when compared with hand instrumentation. In addition, less smear layer was present in the apical region following LightSpeedTM instrumentation than stainless steel hand files, but this difference was not statistically significant. Differences in debridement between the two halves of the same root were more evident with LightSpeedTM than manual instrumentation, however, there was no statistical significance.Conclusions It may be inferred that the choice between hand and LightSpeedTM instrumentation should be based on factors other than the amount of root canal debridement, which does not vary significantly according to the instruments used.
Effects of pulsed Nd:YAG laser irradiation on smear layer at the apical stop and apical leakage after obturation
Authors: Goya C. , Yamazaki R. , Tomita Y. , Kimura Y. , Matsumoto K. 
Published: March 2003

AbstractAimThis study evaluated the removal of smear layer at the apical stop by pulsed Nd:YAG laser irradiation with or without black ink, and the degree of apical leakage after obturation in vitro.MethodologySixty extracted human single‐rooted teeth were used in this study. The teeth were instrumented up to a size 40 K‐file, and then divided into three groups of 20 teeth each: group 1 was unlased as a control group; group 2 was treated with a laser; group 3 was treated with a laser and black ink. The laser was operated at 2 W and 20 pp for 2 s, and irradiation was performed twice with a 30‐s interval. In each group, 10 teeth for the leakage study were obturated and immersed in rhodamine B solution for 48 h at 37 °C, and the others were used for evaluation of remaining smear layer. All teeth were bisected longitudinally and observed by stereoscopy or scanning electron microscopy.ResultsThe smear layer in the laser‐treated groups almost melted or evaporated, and was removed significantly compared with the control group (P < 0.05). Leakage was observed in 60% of samples in group 1 and in 20% of samples in group 2. No leakage was observed in group 3, which was significantly different from the control (P < 0.05).ConclusionsThese results suggest that pulsed Nd:YAG laser irradiation with black ink increases the removal of smear layer compared with that without black ink, and reduces apical leakage after obturation significantly.
Sealer distribution in root canals obturated by three techniques
Authors: Wu M.‐K. , Özok A. R. , Wesselink P. R. 
Published: March 2003

AbstractAimThe aim of this study was to observe sealer distribution in root canals filled by different root filling techniques.MethodologyAH26 (0.05 mL) dyed with carbon black powder was placed into the prepared root canals of maxillary central incisors using a lentulo spiral. Thereafter the canals were obturated using three different gutta‐percha root‐filling techniques. Horizontal sections were cut in the apical and middle portions of the filled canals. Images of the cross sections were scanned and the percentage of sealer coated canal perimeter (PSCP) was measured using a computer digital imaging system.ResultsAt 3 mm from the apex, the PSCP after lateral condensation was similar to that after vertical condensation (P > 0.05). At 6 mm from the apex, however, the PSCP was significantly higher after lateral condensation than after vertical condensation (P < 0.05). At both levels the PSCP was significantly higher after single cone (no condensation) than after the other two condensation techniques (P < 0.0001).ConclusionsSealer may be removed from the canal wall by the condensation procedures.